Acetaldehyde-induced structural and conformational alterations in human immunoglobulin G: A physicochemical and multi-spectroscopic study.

PubMed

Waris, Sana; Habib, Safia; Tantry, Irfan Qadir; Khan, Rizwan Hasan; Mahmood, Riaz; Ali, Asif

2018-07-01

Acetaldehyde is a reactive aldehyde produced as an intermediate of alcohol metabolism and tobacco pyrolysis. It has the potential to interact with different biomolecules in various tissues which results in the formation of stable, unstable and covalent adducts. This causes structural and functional modifications that may lead to severe complications such as cancer. This study has probed the structural modifications in human immunoglobulin G (IgG) as a function of different concentrations of acetaldehyde in the presence of reducing agent, sodium borohydride. Acetaldehyde mediated modifications in IgG have been characterised by various physicochemical techniques. UV-spectrophotometry showed that acetaldehyde modified IgG exhibited marked increase in hyperchromicity. Fluorescence studies revealed a significant quenching of tryptophan fluorescence which resulted in loss of β-sheet secondary structure that was confirmed by circular dichroic analysis. Gross structural changes in the morphology of IgG were confirmed by increase in mass and hydrodynamic radius of this glycoprotein along with the appearance of fibrillar structures in modified IgG, when compared to the granular structure of the native form of IgG observed by scanning electron microscope. The results indicate that acetaldehyde causes alterations in the secondary and tertiary structure of the protein leading to diminution of normal function of IgG molecule. Copyright © 2018 Elsevier B.V. All rights reserved.

Methylglyoxal produces more changes in biochemical and biophysical properties of human IgG under high glucose compared to normal glucose level

PubMed Central

Khan, Mohd Adnan; Arif, Zarina; Khan, Mohd Asad; Moinuddin

2018-01-01

Hyperglycaemia triggers increased production of methylglyoxal which can cause gross modification in proteins’ structure vis-a-vis function though advanced glycation end products (AGEs). The AGEs may initiate vascular and nonvascular pathologies. In this study, we have examined the biochemical and biophysical changes in human IgG under normal and high glucose after introducing methylglyoxal into the assay mixture. This non-enzymatic reaction mainly engaged lysine residues as indicated by TNBS results. The UV results showed hyperchromicity in modified-IgG samples while fluorescence data supported AGEs formation during the course of reaction. Shift in amide I and amide II band position indicated perturbations in secondary structure. Increase carbonyl content and decrease in sulfhydryl suggests that the modification is accompanied by oxidative stress. All modified-IgG samples showed more thermostability than native IgG; the highest Tm was shown by IgG-high glucose-MGO variant. Results of ANS, Congo red and Thioflavin T dyes clearly suggest increase in hydrophobic patches and aggregation, respectively. SEM and TEM images support aggregates generation in modified-IgG samples. PMID:29351321

IgG subclass alterations in adult asthma.

PubMed

Outschoorn, I M; Natta, C L

1992-01-01

Immunoglobulin levels were measured in serum samples of 12 black adult non-smoking asthmatic patients, 11 females and 1 male, and compared with 15 age-, sex-matched normal controls. Their total IgG, IgA and IgM levels were within the normal range. However, on quantitation of subclasses, IgG1 levels were significantly above normal, while IgG2 and IgG3 levels were significantly lower than those of controls. No significant differences were found between the two groups when IgG4 levels were compared. These studies as well as those of others suggest that immunoglobulin administration, particularly of individual subclasses, might prove to be a beneficial addition in the management of this condition.

IgG2 deficiency in sickle cell anaemia.

PubMed

Natta, C L; Outschoorn, I M

1984-08-01

8 patients with known sickle cell anaemia were studied immunologically. The concentrations of the main immunoglobulin classes, IgG and IgA, were significantly higher than the levels in 11 normal age- and sex-matched black subjects (P less than 0.01). IgM levels were not significantly different in the two groups. There was a heterogeneity in the interaction of the IgG subclasses with Protein A, with low levels of IgG2. The IgG2:IgG1 ratios varied from 1:3.8 to 1:6 (normals 1:3). In 4 patients the absolute levels of IgG2 as measured by radial immunodiffusion were lower than normal, thus confirming the chromatographic ratios. Since specific antibody is often restricted to a single subclass, the levels of IgG subclasses may be related to recurrent bacterial infections in these patients.

Induction of keratinocyte IL-8 expression and secretion by IgG autoantibodies as a novel mechanism of epidermal neutrophil recruitment in a pemphigus variant

PubMed Central

O'toole, E A; Mak, L L; Guitart, J; Woodley, D T; Hashimoto, T; Amagai, M; Chan, L S

2000-01-01

A subset of pemphigus herpetiformis, a rare pemphigus variant, is characterized histopathologically by subcorneal acantholysis and neutrophilic infiltration. The mechanism of neutrophil infiltration is unknown, but chemokines such as IL-8 may play a role. We investigated the possible role of IL-8 in two such cases. Direct and indirect immunofluorescence studies demonstrated in vivo-bound and circulating IgG epithelial cell surface-binding autoantibodies, both predominated by IgG4 subclass. ELISA and immunoblotting studies revealed that the patients' IgG autoantibodies recognized recombinant desmoglein 1 but not desmoglein 3. Preadsorption of the patients' sera with recombinant desmoglein 1 completely removed the epidermal cell surface immunostaining. Significantly, immunohistochemistry demonstrated intense expression of IL-8, co-localized with in vivo-bound IgG, in the upper epidermis, where the acantholysis took place. Affinity-purified sera IgG from these two patients, a normal individual, and a pemphigus vulgaris patient containing desmoglein 1 autoantibodies, were incubated with normal human keratinocytes in vitro. Cells treated with these patients' IgG secreted a seven-to-nine-fold increase of IL-8 (30–37 pg/ml) compared with the controls (2–4 pg/ml) and expressed a higher intensity of cytoplasmic IL-8 staining. These data demonstrate a novel functional role for IL-8 in the pathogenesis of the neutrophil-dominant subset of pemphigus herpetiformis. The autoantibody-induced epidermal cell IL-8 expression may represent a novel mechanism of epidermal neutrophil recruitment. PMID:10606986

Effect of light chain V region duplication on IgG oligomerization and in vivo efficacy.

PubMed

Shuford, W; Raff, H V; Finley, J W; Esselstyn, J; Harris, L J

1991-05-03

A human immunoglobulin G1 (IgG1) antibody oligomer was isolated from a transfected myeloma cell line that produced a monoclonal antibody to group B streptococci. Compared to the IgG1 monomer, the oligomer was significantly more effective at protecting neonatal rats from infection in vivo. The oligomer was also shown to cross the placenta and to be stable in neonatal rats. Immunochemical analysis and complementary DNA sequencing showed that the transfected cell line produced two distinct kappa light chains: a normal light chain (Ln) with a molecular mass of 25 kilodaltons and a 37-kilodalton species (L37), the domain composition of which was variable-variable-constant (V-V-C). Cotransfection of vectors encoding the heavy chain and L37 resulted in production of oligomeric IgG.

Human IgG subclass cross-species reactivity to mouse and cynomolgus monkey Fcγ receptors.

PubMed

Derebe, Mehabaw G; Nanjunda, Rupesh K; Gilliland, Gary L; Lacy, Eilyn R; Chiu, Mark L

2018-05-01

In therapeutic antibody discovery and early development, mice and cynomolgus monkey are used as animal models to assess toxicity, efficacy and other properties of candidate molecules. As more candidate antibodies are based on human immunoglobulin (IgG) subclasses, many strategies are pursued to simulate the human system in the test animal. However, translation rate from a successful preclinical trial to an approved drug is extremely low. This may partly be due to differences in interaction of human IgG based candidate molecules to endogenous Fcγ receptors of model animals in comparison to those of human Fcγ receptors. In this study, we compare binding characteristics of human IgG subclasses commonly used in drug development (IgG1, IgG2, IgG4) and their respective Fc silent versions (IgG1σ, IgG2σ, IgG4 PAA) to human, mouse, and cynomolgus monkey Fcγ receptors. To control interactions between Fab and Fc domains, the test IgGs all have the same variable region sequences. We found distinct variations of interaction of human IgG subclasses to model animal Fcγ receptors in comparison to their human counterparts. Particularly, cynomolgus monkey Fcγ receptors showed consistently tighter binding to human IgGs than human Fcγ receptors. Moreover, the presumably Fc silent human IgG4 PAA framework bound to cynomolgus monkey FcγRI with nanomolar affinity while only very weak binding was observed for the human FcγRI. Our results highlighted the need for a thorough in vitro affinity characterization of candidate IgGs against model animal Fcγ receptors and careful design of preclinical studies. Copyright © 2018. Published by Elsevier B.V.

IgG abnormality in narcolepsy and idiopathic hypersomnia.

PubMed

Tanaka, Susumu; Honda, Makoto

2010-03-05

A close association between narcolepsy and the Human Leukocyte Antigen (HLA)-DQB1*0602 allele suggests the involvement of the immune system, or possibly an autoimmune process. We investigated serum IgG levels in narcolepsy. We measured the serum total IgG levels in 159 Japanese narcolepsy-cataplexy patients positive for the HLA-DQB1*0602 allele, 28 idiopathic hypersomnia patients with long sleep time, and 123 healthy controls (the HLA-DQB1*0602 allele present in 45 subjects). The serum levels of each IgG subclass were subsequently measured. The distribution of serum IgG was significantly different among healthy controls negative for the HLA-DQB1*0602 allele (11.66+/-3.55 mg/ml), healthy controls positive for the HLA-DQB1*0602 allele (11.45+/-3.43), narcolepsy patients (9.67+/-3.38), and idiopathic hypersomnia patients (13.81+/-3.80). None of the following clinical variables, age, disease duration, Epworth Sleepiness Scale, smoking habit and BMI at the time of blood sampling, were associated with IgG levels in narcolepsy or idiopathic hypersomnia. Furthermore we found the decrease in IgG1 and IgG2 levels, stable expression of IgG3, and the increase in the proportion of IgG4 in narcolepsy patients with abnormally low IgG levels. The increase in the proportion of IgG4 levels was also found in narcolepsy patients with normal serum total IgG levels. Idiopathic hypersomnia patients showed a different pattern of IgG subclass distribution with high IgG3 and IgG4 level, low IgG2 level, and IgG1/IgG2 imbalance. Our study is the first to determine IgG abnormalities in narcolepsy and idiopathic hypersomnia by measuring the serum IgG levels in a large number of hypersomnia patients. The observed IgG abnormalities indicate humoral immune alterations in narcolepsy and idiopathic hypersomnia. Different IgG profiles suggest immunological differences between narcolepsy and idiopathic hypersomnia.

Characterization and screening of IgG binding to the neonatal Fc receptor

PubMed Central

Neuber, Tobias; Frese, Katrin; Jaehrling, Jan; Jäger, Sebastian; Daubert, Daniela; Felderer, Karin; Linnemann, Mechthild; Höhne, Anne; Kaden, Stefan; Kölln, Johanna; Tiller, Thomas; Brocks, Bodo; Ostendorp, Ralf; Pabst, Stefan

2014-01-01

The neonatal Fc receptor (FcRn) protects immunoglobulin G (IgG) from degradation and increases the serum half-life of IgG, thereby contributing to a higher concentration of IgG in the serum. Because altered FcRn binding may result in a reduced or prolonged half-life of IgG molecules, it is advisable to characterize Fc receptor binding of therapeutic antibody lead candidates prior to the start of pre-clinical and clinical studies. In this study, we characterized the interactions between FcRn of different species (human, cynomolgus monkey, mouse and rat) and nine IgG molecules from different species and isotypes with common variable heavy (VH) and variable light chain (VL) domains. Binding was analyzed at acidic and neutral pH using surface plasmon resonance (SPR) and biolayer interferometry (BLI). Furthermore, we transferred the well-accepted, but low throughput SPR-based method for FcRn binding characterization to the BLI-based Octet platform to enable a higher sample throughput allowing the characterization of FcRn binding already during early drug discovery phase. We showed that the BLI-based approach is fit-for-purpose and capable of discriminating between IgG molecules with significant differences in FcRn binding affinities. Using this high-throughput approach we investigated FcRn binding of 36 IgG molecules that represented all VH/VL region combinations available in the fully human, recombinant antibody library Ylanthia®. Our results clearly showed normal FcRn binding profiles for all samples. Hence, the variations among the framework parts, complementarity-determining region (CDR) 1 and CDR2 of the fragment antigen binding (Fab) domain did not significantly change FcRn binding. PMID:24802048

IgG4-Associated Cholangitis Can Mimic Hilar Cholangiocarcinoma.

PubMed

Zaydfudim, Victor M; Wang, Andrew Y; de Lange, Eduard E; Zhao, Zimin; Moskaluk, Christopher A; Bauer, Todd W; Adams, Reid B

2015-07-01

IgG4-associated cholangitis can mimic hilar cholangiocarcinoma. Previously reported patients with IgG4-associated cholangitis mimicking cholangiocarcinoma had elevated serum IgG4 levels and long-segment biliary strictures. However, in the absence of other diagnostic criteria for malignancy, IgG4-associated cholangitis should remain a consideration among patients with normal serum IgG4 and a hilar mass suspicious for cholangiocarcinoma. The presence of a hilar mass and a malignant-appearing biliary stricture in two patients with normal serum IgG4 prompted further evaluation and subsequent concomitant liver and bile duct resection and reconstruction. The diagnosis of IgG4-associated cholangitis was established during the pathologic evaluation of the resected specimens. IgG4-associated cholangitis is a known imitator of hilar cholangiocarcinoma and should be considered in the differential diagnosis even among serologically IgG4-negative patients with a hilar mass prior to operative resection.

Antibodies Against Hypocretin Receptor 2 Are Rare in Narcolepsy.

PubMed

Giannoccaro, Maria Pia; Waters, Patrick; Pizza, Fabio; Liguori, Rocco; Plazzi, Giuseppe; Vincent, Angela

2017-02-01

Recently, antibodies to the hypocretin receptor 2 (HCRTR2-Abs) were reported in a high proportion of narcolepsy patients who developed the disease following Pandemrix® vaccination. We tested a group of narcolepsy patients for the HCRTR2-Abs using a newly established cell-based assay. Sera from 50 narcolepsy type 1 (NT1) and 11 narcolepsy type 2 (NT2) patients, 22 patients with other sleep disorders, 15 healthy controls, and 93 disease controls were studied. Cerebrospinal fluid (CSFs) from three narcoleptic patients were subsequently included. Human embryonic kidney cells were transiently transfected with human HCRTR2, incubated with patients' sera for 1 hr at 1:20 dilution and then fixed. Binding of antibodies was detected by fluorescently labeled secondary antibodies to human immunoglobulin G (IgG) and the different IgG subclasses. A nonlinear visual scoring system was used from 0 to 4; samples scoring ≥1 were considered positive. Only 3 (5%) of 61 patients showed a score ≥1, one with IgG1- and two with IgG3-antibodies, but titers were low (1:40-1:100). CSFs from these patients were negative. The three positive patients included one NT1 case with associated psychotic features, one NT2 patient, and an NT1 patient with normal hypocretin CSF levels. Low levels of IgG1 or IgG3 antibodies against HCRTR2 were found in 3 of 61 patients with narcolepsy, although only 1 presented with full-blown NT1. HCRTR2-Abs are not common in narcolepsy unrelated to vaccination. © Sleep Research Society 2016. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Human monoclonal antibodies reactive with human myelomonocytic leukemia cells.

PubMed

Posner, M R; Santos, D J; Elboim, H S; Tumber, M B; Frackelton, A R

1989-04-01

Peripheral blood mononuclear cells from a patient with chronic myelogenous leukemia (CML), in remission, were depleted of CD8-positive T-cells and cultured with Epstein-Barr virus. Four of 20 cultures (20%) secreted human IgG antibodies selectively reactive with the cell surfaces of certain human leukemia cell lines. Three polyclonal, Epstein-Barr virus-transformed, B-cell lines were expanded and fused with the human-mouse myeloma analogue HMMA2.11TG/O. Antibody from secreting clones HL 1.2 (IgG1), HL 2.1 (IgG3), and HL 3.1 (IgG1) have been characterized. All three react with HL-60 (promyelocytic), RWLeu4 (CML promyelocytic), and U937 (monocytic), but not with KG-1 (myeloblastic) or K562 (CML erythroid). There is no reactivity with T-cell lines, Burkitt's cell lines, pre-B-leukemia cell lines, or an undifferentiated CML cell line, BV173. Leukemic cells from two of seven patients with acute myelogenous leukemia and one of five with acute lymphocytic leukemia react with all three antibodies. Normal lymphocytes, monocytes, polymorphonuclear cells, red blood cells, bone marrow cells, and platelets do not react. Samples from patients with other diverse hematopoietic malignancies showed no reactivity. Immunoprecipitations suggest that the reactive antigen(s) is a lactoperoxidase iodinatable series of cell surface proteins with molecular weights of 42,000-54,000 and a noniodinatable protein with a molecular weight of 82,000. Based on these data these human monoclonal antibodies appear to react with myelomonocytic leukemic cells and may detect a leukemia-specific antigen or a highly restricted differentiation antigen.

A human anti-dsDNA monoclonal antibody caused hyaline thrombi formation in kidneys of ‘leaky’ SCID mice

PubMed Central

Mason, L J; Ravirajan, C T; Latchman, D S; Isenberg, D A

2001-01-01

There are few studies assessing the pathogenicity of human monoclonal anti-DNA antibodies. The use of SCID mice avoids the problem of rejection of the human hybridoma cells thus allowing in vivo assessment of human immunoglobulins. Using electron microscopy we have shown that the human IgG anti-dsDNA monoclonal antibody, RH14, is nephritogenic in SCID mice, causing morphological changes in the kidney due to immunoglobulin deposition. The problem with using SCID mice is that they have an abnormal immune system; normally they are used at about 2 months of age, at which time they have virtually no functional T or B cells. It is known that older SCID mice become increasingly ‘leaky’, that is they develop some mature lymphocyte clones. Our aim was to assess if implanting anti-DNA antibodies into older ‘leaky’ SCID mice would result in pathology which was observable by light microscopy. Eight-month-old SCID mice were implanted with human hybridoma cells secreting either RH14 an anti-dsDNA IgG, CL24, an antiphospholipid antibody or an irrelevant human IgG control. As previously, RH14 deposited in the kidney and caused proteinuria but unexpectedly we also observed hyaline thrombi in the kidney glomeruli and peritubular capillaries. These thrombi occurred only in the case of RH14 implanted mice and were found to stain positively for human IgG and fibrin. However, apart from the interesting thrombi, we did not observe any greater pathological damage resulting from the anti-dsDNA antibody deposition than we had seen in the younger mice; indeed, the electron microscopic findings were more limited. PMID:11678910

A Recombinant Positive Control for Serology Diagnostic Tests Supporting Elimination of Onchocerca volvulus.

PubMed

Golden, Allison; Stevens, Eric J; Yokobe, Lindsay; Faulx, Dunia; Kalnoky, Michael; Peck, Roger; Valdez, Melissa; Steel, Cathy; Karabou, Potochoziou; Banla, Méba; Soboslay, Peter T; Adade, Kangi; Tekle, Afework H; Cama, Vitaliano A; Fischer, Peter U; Nutman, Thomas B; Unnasch, Thomas R; de los Santos, Tala; Domingo, Gonzalo J

2016-01-01

Serological assays for human IgG4 to the Onchocerca volvulus antigen Ov16 have been used to confirm elimination of onchocerciasis in much of the Americas and parts of Africa. A standardized source of positive control antibody (human anti-Ov16 IgG4) will ensure the quality of surveillance data using these tests. A recombinant human IgG4 antibody to Ov16 was identified by screening against a synthetic human Fab phage display library and converted into human IgG4. This antibody was developed into different positive control formulations for enzyme-linked immunosorbent assay (ELISA) and rapid diagnostic test (RDT) platforms. Variation in ELISA results and utility as a positive control of the antibody were assessed from multiple laboratories. Temperature and humidity conditions were collected across seven surveillance activities from 2011-2014 to inform stability requirements for RDTs and positive controls. The feasibility of the dried positive control for RDT was evaluated during onchocerciasis surveillance activity in Togo, in 2014. When the anti-Ov16 IgG4 antibody was used as a standard dilution in horseradish peroxidase (HRP) and alkaline phosphatase (AP) ELISAs, the detection limits were approximately 1ng/mL by HRP ELISA and 10ng/mL by AP ELISA. Positive control dilutions and spiked dried blood spots (DBS) produced similar ELISA results. Used as a simple plate normalization control, the positive control antibody may improve ELISA data comparison in the context of inter-laboratory variation. The aggregate temperature and humidity monitor data informed temperature parameters under which the dried positive control was tested and are applicable inputs for testing of diagnostics tools intended for sub-Saharan Africa. As a packaged positive control for Ov16 RDTs, stability of the antibody was demonstrated for over six months at relevant temperatures in the laboratory and for over 15 weeks under field conditions. The recombinant human anti-Ov16 IgG4 antibody-based positive control will benefit inter-laboratory validation of ELISA assays and serve as quality control (QC) reagents for Ov16 RDTs at different points of the supply chain from manufacturer to field use.

The interaction of ruminant IgG with receptor type II for IgG on human phagocytes.

PubMed Central

Jungi, T W; Peterhans, E; Pfister, H; Fey, H

1989-01-01

The interaction of ruminant IgG with human phagocytes was assessed using Fc receptor (FcR)-mediated ingestion and the triggering of a respiratory burst as effector functions indicative of receptor-specific interaction. In monomeric form, ruminant IgG was three to five orders of magnitude less potent than homologous IgG in inhibiting FcR-specific phagocytosis by monocytes. However, when attached to tanned sheep erythrocytes (Es-T), ruminant IgG was opsonic, as it promoted enhanced phagocytosis of Es-T, comparable to ingestion of rabbit IgG-coated Es. This phagocytosis was inhibitable by high concentrations of human IgG in the fluid phase. Moreover, Es-T precoated with ferritin could be opsonized to a similar degree by anti-ferritin IgG from rabbit and cow. However, only bovine IgG1, but not IgG2, was opsonic. Bovine and goat IgG of some, but not other, suppliers were inactive. Similar results were obtained by measuring the respiratory burst triggered by heat-aggregated IgG, using a luminol-enhanced chemiluminescence assay. Thus, human IgG and ruminant IgG stimulated monocytes and, to a lesser extent, polymorphonuclear leucocytes (PMN), to generate CL. Depending on the manufacturer, some preparations of bovine and goat IgG were inactive, and bovine IgG2 failed to induce CL. These findings prove that certain ruminant IgG preparations, including bovine IgG1 interacting weakly with homologous PMN and monocytes, do interact with human PMN, monocytes and macrophages in a FcR-specific manner when offered in complexed form. Inhibition studies suggest that bovine IgG1 interacts mainly with human FcR type II. In contrast, bovine IgG2, regarded as cytophilic for homologous PMN, fails to interact with human PMN, monocytes and macrophages. PMID:15493277

Hypogammaglobulinemia associated with accelerated catabolism of IgG secondary to its interaction with an IgG-reactive monoclonal IgM

PubMed Central

Waldmann, Thomas A.; Johnson, John S.; Talal, Norman

1971-01-01

Hypogammaglobulinemia due to a new pathophysiological mechanism was studied in a patient with Sjögren's syndrome, a monoclonal IgM and a mixed (IgM-IgG) cryoglobulinemia. The IgM (IgMdk) component of the cryogel possessed light chains of λ-type with highly restricted electrophoretic mobility analagous to those of a Waldenström's macroglobulin. IgMdk reacted specifically with native IgG, with IgG subclasses 1, 2, and 4, and with the Fc piece of IgG to form a cryogel. Serum concentrations of IgG 1, 2, and 4 were 10% of normal, whereas the IgG3 level was slightly increased and the IgM level was markedly increased. Viscosity and analytical ultracentrifugation studies with the purified mixed cryogel (IgM-LgG) indicated soluble complex formation over a temperature range (36-38°C) attainable in vivo. Immunoglobulin turnover studies revealed a markedly elevated rate of IgM synthesis with a normal survival of IgM, IgA, and IgE. IgG3, which failed to form complexes with IgMdk at body temperature, had a normal synthetic rate and survival. In contrast, the other IgG subclasses showed reduced synthesis and shortened survival. These studies are the first indicating a short survival of some IgG subclasses with a normal survival of another. The hypogammaglobulinemia appears to be due in part to a new mechanism of accelerated protein catabolism: The rapid elimination of IgG due to its interaction with an IgG-reactive monoclonal IgM. PMID:4993860

Quantitative cumulative biodistribution of antibodies in mice: effect of modulating binding affinity to the neonatal Fc receptor.

PubMed

Yip, Victor; Palma, Enzo; Tesar, Devin B; Mundo, Eduardo E; Bumbaca, Daniela; Torres, Elizabeth K; Reyes, Noe A; Shen, Ben Q; Fielder, Paul J; Prabhu, Saileta; Khawli, Leslie A; Boswell, C Andrew

2014-01-01

The neonatal Fc receptor (FcRn) plays an important and well-known role in antibody recycling in endothelial and hematopoietic cells and thus it influences the systemic pharmacokinetics (PK) of immunoglobulin G (IgG). However, considerably less is known about FcRn's role in the metabolism of IgG within individual tissues after intravenous administration. To elucidate the organ distribution and gain insight into the metabolism of humanized IgG1 antibodies with different binding affinities FcRn, comparative biodistribution studies in normal CD-1 mice were conducted. Here, we generated variants of herpes simplex virus glycoprotein D-specific antibody (humanized anti-gD) with increased and decreased FcRn binding affinity by genetic engineering without affecting antigen specificity. These antibodies were expressed in Chinese hamster ovary cell lines, purified and paired radiolabeled with iodine-125 and indium-111. Equal amounts of I-125-labeled and In-111-labeled antibodies were mixed and intravenously administered into mice at 5 mg/kg. This approach allowed us to measure both the real-time IgG uptake (I-125) and cumulative uptake of IgG and catabolites (In-111) in individual tissues up to 1 week post-injection. The PK and distribution of the wild-type IgG and the variant with enhanced binding for FcRn were largely similar to each other, but vastly different for the rapidly cleared low-FcRn-binding variant. Uptake in individual tissues varied across time, FcRn binding affinity, and radiolabeling method. The liver and spleen emerged as the most concentrated sites of IgG catabolism in the absence of FcRn protection. These data provide an increased understanding of FcRn's role in antibody PK and catabolism at the tissue level.

Quantitative cumulative biodistribution of antibodies in mice

PubMed Central

Yip, Victor; Palma, Enzo; Tesar, Devin B; Mundo, Eduardo E; Bumbaca, Daniela; Torres, Elizabeth K; Reyes, Noe A; Shen, Ben Q; Fielder, Paul J; Prabhu, Saileta; Khawli, Leslie A; Boswell, C Andrew

2014-01-01

The neonatal Fc receptor (FcRn) plays an important and well-known role in antibody recycling in endothelial and hematopoietic cells and thus it influences the systemic pharmacokinetics (PK) of immunoglobulin G (IgG). However, considerably less is known about FcRn’s role in the metabolism of IgG within individual tissues after intravenous administration. To elucidate the organ distribution and gain insight into the metabolism of humanized IgG1 antibodies with different binding affinities FcRn, comparative biodistribution studies in normal CD-1 mice were conducted. Here, we generated variants of herpes simplex virus glycoprotein D-specific antibody (humanized anti-gD) with increased and decreased FcRn binding affinity by genetic engineering without affecting antigen specificity. These antibodies were expressed in Chinese hamster ovary cell lines, purified and paired radiolabeled with iodine-125 and indium-111. Equal amounts of I-125-labeled and In-111-labeled antibodies were mixed and intravenously administered into mice at 5 mg/kg. This approach allowed us to measure both the real-time IgG uptake (I-125) and cumulative uptake of IgG and catabolites (In-111) in individual tissues up to 1 week post-injection. The PK and distribution of the wild-type IgG and the variant with enhanced binding for FcRn were largely similar to each other, but vastly different for the rapidly cleared low-FcRn-binding variant. Uptake in individual tissues varied across time, FcRn binding affinity, and radiolabeling method. The liver and spleen emerged as the most concentrated sites of IgG catabolism in the absence of FcRn protection. These data provide an increased understanding of FcRn’s role in antibody PK and catabolism at the tissue level. PMID:24572100

Biophysical and Functional Characterization of Rhesus Macaque IgG Subclasses

PubMed Central

Boesch, Austin W.; Osei-Owusu, Nana Yaw; Crowley, Andrew R.; Chu, Thach H.; Chan, Ying N.; Weiner, Joshua A.; Bharadwaj, Pranay; Hards, Rufus; Adamo, Mark E.; Gerber, Scott A.; Cocklin, Sarah L.; Schmitz, Joern E.; Miles, Adam R.; Eckman, Joshua W.; Belli, Aaron J.; Reimann, Keith A.; Ackerman, Margaret E.

2016-01-01

Antibodies raised in Indian rhesus macaques [Macaca mulatta (MM)] in many preclinical vaccine studies are often evaluated in vitro for titer, antigen-recognition breadth, neutralization potency, and/or effector function, and in vivo for potential associations with protection. However, despite reliance on this key animal model in translation of promising candidate vaccines for evaluation in first in man studies, little is known about the properties of MM immunoglobulin G (IgG) subclasses and how they may compare to human IgG subclasses. Here, we evaluate the binding of MM IgG1, IgG2, IgG3, and IgG4 to human Fc gamma receptors (FcγR) and their ability to elicit the effector functions of human FcγR-bearing cells, and unlike in humans, find a notable absence of subclasses with dramatically silent Fc regions. Biophysical, in vitro, and in vivo characterization revealed MM IgG1 exhibited the greatest effector function activity followed by IgG2 and then IgG3/4. These findings in rhesus are in contrast with the canonical understanding that IgG1 and IgG3 dominate effector function in humans, indicating that subclass-switching profiles observed in rhesus studies may not strictly recapitulate those observed in human vaccine studies. PMID:28018355

The binding of human and guinea-pig IgG subclasses to homologous macrophage and monocyte Fc receptors.

PubMed Central

Alexander, M D; Andrews, J A; Leslie, R G; Wood, N J

1978-01-01

Guinea-pig IgG2 and IgT1 bind to contiguous Fc receptors on homologous peritoneal macrophages. Equilibrium association constants determined for the binding of human IgG subclasses to homologous peripheral blood monocytes show that the order of binding is IgG1 greater than IgG3 greater than IgG4 greater than IgG2. Direct binding and rosette assay techniques independently established that both guinea-pig IgG2 and human IgG bind to homologous macrophage-monocyte Fc receptors through a site present in whole Fc (CH2. CH3)2, but absent in pFc' subfragments (CH3)2. PMID:680795

BINDING OF SOLUBLE IMMUNE COMPLEXES TO HUMAN LYMPHOBLASTOID CELLS

PubMed Central

Theofilopoulos, Argyrios N.; Dixon, Frank J.; Bokisch, Viktor A.

1974-01-01

In the present work we studied the expression of membrane-bound Ig (MBIg) as well as receptors for IgG Fc and complement on nine human lymphoblastoid cell lines. When MBIg and receptors for IgG Fc were compared, four categories of cell lines could be distinguished: (a) cell lines having both MBIg and receptors for IgG Fc, (b) cell lines having MBIg but lacking receptors for IgG Fc, (c) cell lines lacking MBIg but having receptors for IgG Fc, and (d) cell lines lacking both MBIg and receptors for IgG Fc. Two types of receptors for complement could be detected on the cell lines studied, one for C3-C3b and one for C3d. When sensitized red cells carrying C3b or C3d were used for rosette tests, three categories of cell lines could be distinguished: (a) cell lines having receptors for C3b and C3d, (b) cell lines having receptors only for C3d and (c) cell lines lacking both receptors. However, when a more sensitive immunofluorescent method was used instead of the rosette technique, it was found that cell lines unable to form rosettes with EAC1423bhu were able to bind soluble C3 or C3b which indicated the presence of these receptors on the cell surface. Inhibition experiments showed that receptors for C3-C3b and receptors for C3d are distinct and that receptors for C3-C3b and C3d are different from receptors for IgG Fc. A cell line (Raji) without MBIg but with receptors for IgG Fc, C3-C3b, and C3d was selected for use in studying the binding mechanism of soluble immune complexes to cell surface membrane. Aggregated human gamma globulin was used in place of immune complexes. Immune complexes containing complement bind to Raji cells only via receptors for complement, namely receptors for C3-C3b and C3d. Binding of immune complexes containing complement to cells is much greater than that of complexes without complement. Immune complexes bound to cells via receptors for complement can be partially released from the cell surface by addition of normal human serum as well as isolated human C3 or C3b. We postulate that such release is due to competition of immune complex bound C3b and free C3 or C3b for the receptors on Raji cells. PMID:4139225

Expression of senescent antigen on erythrocytes infected with a knobby variant of the human malaria parasite Plasmodium falciparum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Winograd, E.; Greenan, J.R.T.; Sherman, I.W.

Erythrocytes infected with a knobby variant of Plasmodium falciparum selectively bind IgG autoantibodies in normal human serum. Quantification of membrane-bound IgG, by use of /sup 125/I-labeled protein A, revealed that erythrocytes infected with the knobby variant bound 30 times more protein A than did noninfected erythrocytes; infection with a knobless variant resulted in less than a 2-fold difference compared with noninfected erythrocytes. IgG binding to knobby erythrocytes appeared to be related to parasite development, since binding of /sup 125/I-labeled protein A to cells bearing young trophozoites (less than 20 hr after parasite invasion) was similar to binding to uninfected erythrocytes.more » By immunoelectron microscopy, the membrane-bound IgG on erythrocytes infected with the knobby variant was found to be preferentially associated with the protuberances (knobs) of the plasma membrane. The removal of aged or senescent erythrocytes from the peripheral circulation is reported to involve the binding of specific antibodies to an antigen (senescent antigen) related to the major erythrocyte membrane protein band 3. Since affinity-purified autoantibodies against band 3 specifically bound to the plasma membrane of erythrocytes infected with the knobby variant of P. falciparum, it is clear that the malaria parasite induces expression of senescent antigen.« less

Non-Immune Binding of Human IgG to M-Related Proteins Confers Resistance to Phagocytosis of Group A Streptococci in Blood

PubMed Central

Courtney, Harry S.; Li, Yi

2013-01-01

The non-immune binding of immunoglobulins by bacteria is thought to contribute to the pathogenesis of infections. M-related proteins (Mrp) are group A streptococcal (GAS) receptors for immunoglobulins, but it is not known if this binding has any impact on virulence. To further investigate the binding of immunoglobulins to Mrp, we engineered mutants of an M type 4 strain of GAS by inactivating the genes for mrp, emm, enn, sof, and sfbX and tested these mutants in IgG-binding assays. Inactivation of mrp dramatically decreased the binding of human IgG, whereas inactivation of emm, enn, sof, and sfbx had only minor effects, indicating that Mrp is a major IgG-binding protein. Binding of human immunoglobulins to a purified, recombinant form of Mrp indicated that it selectively binds to the Fc domain of human IgG, but not IgA or IgM and that it preferentially bound subclasses IgG1>IgG4>IgG2>IgG3. Recombinant proteins encompassing different regions of Mrp were engineered and used to map its IgG-binding domain to its A-repeat region and a recombinant protein with 3 A-repeats was a better inhibitor of IgG binding than one with a single A-repeat. A GAS mutant expressing Mrp with an in-frame deletion of DNA encoding the A-repeats had a dramatically reduced ability to bind human IgG and to grow in human blood. Mrp exhibited host specificity in binding IgG; human IgG was the best inhibitor of the binding of IgG followed by pig, horse, monkey, and rabbit IgG. IgG from goat, mouse, rat, cow, donkey, chicken, and guinea pig were poor inhibitors of binding. These findings indicate that Mrp preferentially binds human IgG and that this binding contributes to the ability of GAS to resist phagocytosis and may be a factor in the restriction of GAS infections to the human host. PMID:24205299

Humans with chronic granulomatous disease maintain humoral immunologic memory despite low frequencies of circulating memory B cells.

PubMed

Moir, Susan; De Ravin, Suk See; Santich, Brian H; Kim, Jin Young; Posada, Jacqueline G; Ho, Jason; Buckner, Clarisa M; Wang, Wei; Kardava, Lela; Garofalo, Mary; Marciano, Beatriz E; Manischewitz, Jody; King, Lisa R; Khurana, Surender; Chun, Tae-Wook; Golding, Hana; Fauci, Anthony S; Malech, Harry L

2012-12-06

CD27(+) memory B cells are reduced in the blood of patients with chronic granulomatous disease (CGD) for reasons and consequences that remain unclear. Here we confirm not only decreased CD27(+) but also IgG(+) B cells in the blood of CGD patients compared with healthy donors (HDs). However, among IgG(+) B cells, the ratio of CD27(-) to CD27(+) was significantly higher in CGD patients compared with HDs. Similar to conventional memory B cells, CD27(-)IgG(+) B cells of CGD patients expressed activation markers and had undergone somatic hypermutation, albeit at levels lower than their CD27(+) counterparts. Functional analyses revealed slight reductions in frequencies of total IgG but not influenza-specific memory B-cell responses, as measured by Elispot in CGD patients compared with HDs. Serum IgG levels and influenza-specific antibodies were also normal in these CGD patients. Finally, we provide evidence that influenza-specific memory B cells can be present within the CD27(-)IgG(+) B-cell compartment. Together, these findings show that, despite reduced circulating CD27(+) memory B cells, CGD patients maintain an intact humoral immunologic memory, with potential contribution from CD27(-) B cells.

Natural Mosquito-Pathogen Hybrid IgG4 Antibodies in Vector-Borne Diseases: A Hypothesis.

PubMed

Londono-Renteria, Berlin; Cardenas, Jenny C; Troupin, Andrea; Colpitts, Tonya M

2016-01-01

Chronic exposure to antigens may favor the production of IgG4 antibodies over other antibody types. Recent studies have shown that up to a 30% of normal human IgG4 is bi-specific and is able to recognize two antigens of different nature. A requirement for this specificity is the presence of both eliciting antigens in the same time and at the same place where the immune response is induced. During transmission of most vector-borne diseases, the pathogen is delivered to the vertebrate host along with the arthropod saliva during blood feeding and previous studies have shown the existence of IgG4 antibodies against mosquito salivary allergens. However, there is very little ongoing research or information available regarding IgG4 bi-specificity with regard to infectious disease, particularly during immune responses to vector-borne diseases, such as malaria, filariasis, or dengue virus infection. Here, we provide background information and present our hypothesis that IgG4 may not only be a useful tool to measure exposure to infected mosquito bites, but that these bi-specific antibodies may also play an important role in modulation of the immune response against malaria and other vector-borne diseases in endemic settings.

Measurement of the IgG2 response to Pneumococcal capsular polysaccharides may identify an antibody deficiency in individuals referred for immunological investigation.

PubMed

Parker, Antony; Irure Ventura, Juan; Sims, Dawn; Echeverría de Carlos, Ainara; Gómez de la Torre, Ricardo; Tricas Aizpún, Lourdes; Ocejo-Vinyals, J Gonzalo; López-Hoyos, Marcos; Wallis, Gregg; Harding, Stephen

2017-01-01

IgG2 is the most efficient subclass for providing protection against pneumococcal pathogens. We hypothesised that some individuals may be unable to mount an effective pneumococcal capsular polysaccharide (PCP) IgG2 response despite having a normal PCP IgG concentration (PCP IgG2 deficient). The median pre-vaccination PCP IgG2 concentration was significantly lower in individuals referred for immunological investigation compared to healthy controls (2.8 mg/L range, 95% CI 1.1-88 vs. 29.5mg/L, 95% CI 13.5-90, p = 0.0002). PCP IgG:IgG2 ratios were significantly higher for the referral population than for healthy controls suggesting the increased production of PCP specific subclasses other than IgG2. The percentage of individuals with PCP IgG2 deficiency was significantly higher in referral groups compared to controls (31% vs. 5%; p = 0.0009) and in an individual with PCP IgG2 deficiency, the balance of PCP specific IgG subclass antibodies post vaccination changed from IgG2>IgG1>IgG3>IgG4 to IgG1>IgG3>IgG2>IgG4. The median PCP IgG2 concentration in those with PCP IgG2 deficiency was significantly lower in the referral groups compared to controls (7.8 mg/L, 95% CI 1.1-12 vs. 12.7 mg/L, 95% CI 11.8-13.1; p = 0.006). The data suggests a defect in the production PCP IgG2 may be present in individuals with normal PCP IgG referred for immunological investigation.

Autoantibodies to BP180 associated with bullous pemphigoid release interleukin-6 and interleukin-8 from cultured human keratinocytes.

PubMed

Schmidt, E; Reimer, S; Kruse, N; Jainta, S; Bröcker, E B; Marinkovich, M P; Giudice, G J; Zillikens, D

2000-11-01

Bullous pemphigoid is an inflammatory subepidermal blistering disease that is associated with auto- antibodies to the keratinocyte surface protein, BP180. In addition to the binding of autoantibodies, the infiltration of inflammatory cells is necessary for blister formation. Cytokines, including interleukin-6 and interleukin-8, have been implicated in the disease process of both human and experimental murine bullous pemphigoid. This study was aimed at testing the hypothesis that the binding of anti-BP180 antibodies to their target antigen triggers a signal transduction event that results in the secretion of these pro-inflammatory cytokines. Consistent with this hypothesis, treatment of cultured normal human epidermal keratinocytes with bullous pemphigoid IgG, but not control IgG, led to increased levels of interleukin-6 and interleukin-8, but not interleukin-1alpha, interleukin-1beta, tumor necrosis factor-alpha, interleukin-10, or monocyte chemoattractant protein-1, in the culture medium. This effect was concentration- and time-dependent and was abolished by depleting the bullous pemphigoid IgG of reactivity to two distinct epitopes on the BP180 NC16A domain. Upregulation of interleukin-6 and interleukin-8 was found at both protein and mRNA levels. In addition, bullous pemphigoid IgG did not induce the release of interleukin-6 and interleukin-8 from BP180-deficient keratinocytes obtained from a patient with generalized atrophic benign epidermolysis bullosa. These data indicate that bullous pemphigoid-associated autoantibodies to the human BP180 ectodomain trigger a signal transducing event that leads to expression and secretion of interleukin-6 and interleukin-8 from human keratinocytes.

Immune response in the hamster: definition of a novel IgG not expressed in all hamster strains.

PubMed Central

Coe, J E; Schell, R F; Ross, M J

1995-01-01

A new IgG isotype is described in serum from Syrian hamsters. This 7S-IgG is called IgG3 and was isolated from IgG1 and IgG2 because of its great affinity for protein A. The unique antigenic determinants of IgG3 were identified with a specific rabbit antisera. IgG3 is the least expressed IgG subclass in Syrian hamsters, but serum levels increase more than 10-fold after immunization or infection. Although found in all tested outbred strains, IgG3 is expressed in only some of the commercially available inbred strains of Syrian hamsters. Five inbred hamster strains were examined, and in three strains (CB, LHC and MHA) IgG3 was not detected in normal serum or in immune serum, indicating serum levels at least 100-fold less than other normal inbred/outbred hamsters. The results of breeding experiments suggests a single gene defect is responsible for this non-expression of IgG3. Immunodeficiency was not associated with this IgG3 deficiency. Selective deficiencies of immunoglobulin classes/subclasses in experimental animals are rare. The evolution of a similar IgG3 deficiency in these three hamster strains during inbreeding suggests a novel and efficient mechanism for regulation of IgG3 synthesis in the Syrian hamster. Images Figure 2 Figure 3 Figure 5 PMID:7590875

Diagnostic Performance of Serum IgG4 Levels in Patients With IgG4-Related Disease

PubMed Central

Yu, Kuang-Hui; Chan, Tien-Ming; Tsai, Ping-Han; Chen, Ching-Hui; Chang, Pi-Yueh

2015-01-01

Abstract The aim of this study is to study the clinical features and diagnostic performance of IgG4 in Chinese populations with IgG4-related diseases (IgG4-RDs). The medical records of 2901 adult subjects who underwent serum IgG4 level tests conducted between December 2007 and May 2014 were reviewed. Serum concentrations of IgG4 were measured in 2901 cases, including 161 (5.6%) patients with IgG4-RD and 2740 (94.4%) patients without IgG4-RD (non-IgG4-RD group). The mean age of the IgG4-RD patients was 58.4 ± 16.1 years (range: 21–87), and 48 (29.8%) were women. The mean serum IgG4 level was significantly much higher in IgG4-RD patients than in non-IgG4-RD (1062.6 vs 104.3 mg/dL, P < 0.001) participants. For IgG4 >135 mg/dL, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), likelihood ratio (LR)+, and LR− were 86%, 77%, 18%, 99%, 3.70, and 0.19, respectively. When the upper limit of normal was doubled for an IgG4 >270 mg/dL, the corresponding data were 75%, 94%, 43%, 98%, 12.79, and 0.26, respectively. For IgG4 >405 mg/dL (tripling the upper limit of normal), the corresponding data were 62%, 98%, 68%, 98%, 37.00, and 0.39, respectively. When calculated according to the manufacturer's package insert cutoff (>201 mg/dL) for the diagnosis of IgG4-RD, the corresponding sensitivity, specificity, PPV, NPV, LR+, and LR− were 80%, 89%, 29%, 99%, 7.00, and 0.23, respectively. For IgG4 >402 mg/dL (>2× the upper limit of the normal range), the corresponding data were 62%, 98%, 68%, 98%, 36.21, and 0.39, respectively. For IgG4 >603 mg/dL (>3× the upper limit of the normal range), the corresponding data were 50%, 99%, 84%, 97%, 90.77 and 0.51, respectively. The optimal cutoff value of serum IgG4 (measured by nephelometry using a Siemens BN ProSpec instrument and Siemens reagent) for the diagnosis of IgG4-RD was 248 mg/dL, the sensitivity and specificity were 77.6% and 92.8%, respectively. The present study demonstrated that 2 or 3 times the upper limit of the manufacturer's reference range of the IgG4 level was a useful marker for the diagnosis of various types of IgG4-RD and the optimal cutoff level was 248 mg/dL. PMID:26469909

HETEROCLITIC POLYCLONAL AND MONOCLONAL ANTI-Gm(a) AND ANTI-Gm(g) HUMAN RHEUMATOID FACTORS REACT WITH EPITOPES INDUCED IN Gm(a−) Gm(g−) IgG BY INTERACTION WITH ANTIGEN OR BY NONSPECIFIC AGGREGATION

PubMed Central

WILLIAMS, RALPH C.; MALONE, CHRISTINE C.; CASALI, PAOLO

2015-01-01

Heteroclitic rheumatoid factors (RF) are specific for allotypic determinants, e.g., Gm(a) or Gm(g) on allogeneic, but not autologous IgG. All polyclonal RF we isolated from nine rheumatoid arthritis patients with circulating Gm(a−), (b+), (g−), (f+) IgG displayed dual heteroclitic activity for the Gm(a) and Gm(g) allotypes, as shown by using appropriate RBC agglutination assays and affinity columns bearing Gm(a+) or Gm(g+) IgG. To investigate possible mechanisms underlying the in vivo generation of heteroclitic RF, we tested the ability of non-specifically and immune-specifically aggregated Gm(a−), (g−) IgG to function as targets for RF from Gm(a−), (g−) patients with rheumatoid arthritis. Heat aggregation (63°C for 20 min) or binding to Ag (as in tetanus toxoid-antitetanus toxoid complexes) induced a “functional” Gm(a+) and/or (g+) phenotype in Gm(a−), (g−) IgG from five healthy subjects and five rheumatoid patients, as suggested by the ability of these altered IgG to function as efficient targets for six heteroclitic RF in direct binding and competitive inhibition experiments. That heterocliticity and dual Gm(a), Gm(g) specificity can be features of a single antibody molecule was formally demonstrated by analysis of a monoclonal RF (IgM mAb 61) generated from a Gm(a−), (g−) rheumatoid patient. RF mAb 61 displayed a high affinity (Kd, 10−7 M) for IgG Fc fragment of Gm(a+) and (g+) IgG or aggregated autologous Gm(a−), (g−) IgG but did not bind to native autologous IgG. To investigate the molecular basis of the acquired Gm(a) phenotype, PBMC from five Gm(a−) patients with rheumatoid arthritis and two Gm(a−) normal subjects were cultured in vitro after activation with PWM. In most instances, these PBMC produced IgG that behaved as Gm(a+) in sensitive ELISA. Application of the polymerase chain reaction (PCR), using probes specific for the nucleotide sequence coding for the Gm(a) tetrapeptide, to the amplification of DNA from the in vitro-stimulated Gm(a−) normals or rheumatoid patients’ PBMC provided no evidence for Gm(a) nucleotide sequences. The present data suggest that acquisition of the Gm(a) determinant by Gm(a−) IgG may result from subtle changes in the CH2-CH3 RF-binding region. Such changes would occur when Gm(a) IgG are complexed with Ag or nonspecifically altered, thereby providing a possible explanation for the induction of heteroclitic RF in Gm(a−) rheumatoid arthritis patients. PMID:1380541

Experience with Subgam, a Subcutaneously Administered Human Normal Immunoglobulin (ClinicalTrials.gov--NCT02247141).

PubMed

Dash, Clive; Gascoigne, Ernie; Gillanders, Kate; Gooi, Hock

2015-01-01

A multi-centre, non-comparative study examining the efficacy and safety of Subgam, a normal immunoglobulin (IgG) given weekly as a rapid subcutaneous infusion to patients with primary immune deficiency (PID), is reported. Also included is a summary of adverse drug reactions associated with the use of marketed Subgam in the UK. 50 patients with stable PID on IgG therapy were enrolled: Stage 1 included three infusions with prior IgG product followed by 6 months with Subgam, Stage 2 involved long-term Subgam therapy up to 4 years. Stage 1, 85% of the subjects aged >12 years and 93% of the subjects aged <12 years achieved IgG levels ≥6 and ≥4 g/L, respectively at all observations. There were 3.62 infections/patient/year during Subgam treatment. The most common product-related events were infusion site reactions (50% of patients). Recent post-hoc pharmacokinetics analysis of the post-infusion serum total IgG concentration indicated that the mean dose-normalised incremental IgG AUCτ following intravenous dosing (120.5 g.day/L) was 1.64-fold that of the dose-normalised mean incremental IgG AUCτ following subcutaneous dosing (73.6 g.day/L), corresponding to an estimated IgG bioavailability for subcutaneous dosing of 61%. Only 34 post-licensing adverse reactions have been received in 30 patients over a period of 10 years; fourteen were classed as serious as defined by the ICH guidelines on good clinical practice. The most common post-licensing adverse reaction was infusion site reaction (7 reports). There were 7 reports of flu-like symptoms (pyrexia/shivering/rigors/feeling hot or cold), 2 other reports of combined flu-like symptoms and infusion site reactions, 5 reports of generalised skin reactions, and 3 reports of combined infusion site and skin reactions. There were also reports of anaphylaxis (2 reports) and 8 other adverse events (including headache). In conclusion, Subgam is effective and well tolerated in the treatment of PID. ClinicalTrials.gov NCT02247141.

Combined roles of human IgG subclass, alternative complement pathway activation, and epitope density in the bactericidal activity of antibodies to meningococcal factor h binding protein.

PubMed

Giuntini, Serena; Reason, Donald C; Granoff, Dan M

2012-01-01

Meningococcal vaccines containing factor H binding protein (fHbp) are in clinical development. fHbp binds human fH, which enables the meningococcus to resist complement-mediated bacteriolysis. Previously, we found that chimeric human IgG1 mouse anti-fHbp monoclonal antibodies (MAbs) had human complement-mediated bactericidal activity only if the MAb inhibited fH binding. Since IgG subclasses differ in their ability to activate complement, we investigated the role of human IgG subclasses on antibody functional activity. We constructed chimeric MAbs in which three different murine fHbp-specific binding domains were each paired with human IgG1, IgG2, or IgG3. Against a wild-type group B isolate, all three IgG3 MAbs, irrespective of their ability to inhibit fH binding, had bactericidal activity that was >5-fold higher than the respective IgG1 MAbs, while the IgG2 MAbs had the least activity. Against a mutant with increased fHbp expression, the anti-fHbp MAbs elicited greater C4b deposition (classical pathway) and greater bactericidal activity than against the wild-type strain, and the IgG1 MAbs had similar or greater activity than the respective IgG3 MAbs. The bactericidal activity against both wild-type and mutant strains also was dependent, in part, on activation of the alternative complement pathway. Thus, at lower epitope density in the wild-type strain, the IgG3 anti-fHbp MAbs had the greatest bactericidal activity. At a higher epitope density in the mutant, the IgG1 MAbs had similar or greater bactericidal activity than the IgG3 MAbs, and the activity was less dependent on the inhibition of fH binding than at a lower epitope density.

IgG subclass antibodies to human and bacterial HSP60 are not associated with disease activity and progression over time in axial spondyloarthritis

PubMed Central

2013-01-01

Introduction Spondyloarthritis (SpA), an interrelated group of rheumatic diseases, has been suggested to be triggered by bacterial infections prior to the development of an autoimmune response that causes inflammation of the spinal and peripheral joints. Because human heat shock protein 60 (HSP60), recently renamed HSPD1, and bacterial HSP60 are highly homologous, immunological cross-reactivity has been proposed as a mechanism of disease initiation. However, previous investigations of the humoral immune response to HSP60 in SpA patients have lacked determination of immunoglobulin G (IgG) subclasses and patient follow-up. In this study, we have focused on these parameters in a cohort of axial SpA patients with a well-established set of clinical characteristics, including MRI changes and human leukocyte antigen B27. Methods IgG subclass antibodies (IgG1, IgG2, IgG3 and IgG4) against recombinant HSP60 of three reactive arthritis-related bacteria; human HSP60; and the microorganisms Chlamydia trachomatis and C. pneumoniae were determined by ELISA. Serum samples collected from 2004 to 2006 and in 2010 and 2011 from 39 axial SpA patients were analyzed and compared with samples from 39 healthy controls. The Mann-Whitney U test and Wilcoxon matched pairs test were used to compare the antibody levels in different and paired groups, respectively. P < 0.01 was considered significant. The Spearman nonparametric correlation was used to determine correlation between antibody levels and between antibody levels and the disease parameters. Results Elevated levels of IgG1 and IgG3 to human HSP60 and IgG1 to HSP60 of Salmonella enterica Enteritidis were observed in SpA patients compared with healthy controls at both time points. The antibody levels were almost constant over time for IgG1, whereas high levels of IgG3 to human HSP60 tended to decrease over time. The antibody response to human HSP60 was predominantly of the IgG3 subclass, and patients with high levels of IgG3 to this antigen had low levels of IgG1, indicating an inverse association. Different IgG subclasses were produced against bacterial and human HSP60 in the same serum sample, IgG1 and IgG3, respectively, indicating that there was no cross-reaction. Conclusions A significant association was observed between axial SpA and the presence of IgG1/IgG3 antibodies to human HSP60 and of IgG1 to S. enterica Enteritidis and C. trachomatis. Generation of antibodies to human HSP60 was independent of the presence of antibodies to bacterial HSP60. No association was observed between clinical and MRI changes with antibodies over time. Altogether, such antibodies do not reflect the disease activity in these patients. This study has been approved by the Regional Research Ethics Committee of Central Jutland, Denmark. Trial registration numbers: 20050046 and 20100083 PMID:23705835

Evaluation of Raman spectroscopy in comparison to commonly performed dengue diagnostic tests

NASA Astrophysics Data System (ADS)

Khan, Saranjam; Ullah, Rahat; Khurram, Muhammad; Ali, Hina; Mahmood, Arshad; Khan, Ajmal; Ahmed, Mushtaq

2016-09-01

This study demonstrates the evaluation of Raman spectroscopy as a rapid diagnostic test in comparison to commonly performed tests for an accurate detection of dengue fever in human blood sera. Blood samples of 104 suspected dengue patients collected from Holy Family Hospital, Rawalpindi, Pakistan, have been used in this study. Out of 104 samples, 52 (50%) were positive based on immunoglobulin G (IgG), whereas 54 (52%) were positive based on immunoglobulin M (IgM) antibody tests. For the determination of the diagnostic capabilities of Raman spectroscopy, accuracy, sensitivity, specificity and false positive rate have been calculated in comparison to normally performed IgM and IgG captured enzyme-linked immunosorbent assay tests. Accuracy, precision, specificity, and sensitivity for Raman spectroscopy in comparison to IgM were found to be 66%, 70%, 72%, and 61%, whereas based on IgG they were 47%, 46%, 52%, and 43%, respectively.

Half molecular exchange of IgGs in the blood of healthy humans: chimeric lambda-kappa-immunoglobulins containing HL fragments of antibodies of different subclasses (IgG1-IgG4).

PubMed

Sedykh, Sergey E; Lekchnov, Evgenii A; Prince, Viktor V; Buneva, Valentina N; Nevinsky, Georgy A

2016-10-20

In the classic paradigm, immunoglobulins represent products of clonal B cell populations, each producing antibodies recognizing a single antigen (monospecific). There is a common belief that IgGs in mammalian biological fluids are monospecific molecules having stable structures and two identical antigen-binding sites. But the issue concerning the possibility of exchange by HL-fragments between the antibody molecules in human blood is still unexplored. Different physico-chemical and immunological methods for analysis of half-molecule exchange between human blood IgGs were used. Using eighteen blood samples of healthy humans we have shown unexpected results for the first time: blood antibodies undergo extensive post-transcriptional half-molecule exchange and IgG pools on average consist of 62.4 ± 6.5% IgGs containing kappa light chains (kappa-kappa-IgGs), 29.8.6 ± 5.4% lambda light chains (lambda-lambda-IgGs), and 8.8 ± 2.7% (range 2.6-16.8%) IgGs containing both kappa- and lambda-light chains. Kappa-kappa-IgGs and lambda-lambda-IgGs contained on average (%): IgG1 (36.0 and 32.3), IgG2 (50.9 and 51.4), IgG3 (9.7 and 9.9), and IgG4 (6.5 and 5.7), while chimeric kappa-lambda-IgGs consisted of (%): 25.5 ± 4.2 IgG1, 50.8 ± 3.9 IgG2, 9.1 ± 2.1 IgG3, and 14.5 ± 2.2 IgG4. Our unexpected data are indicative of the possibility of half-molecule exchange between blood IgGs of various subclasses, raised against different antigens. The existence of blood chimeric bifunctional IgGs with different binding sites destroys the classic paradigm. Due to the phenomenon of polyspecificity and cross-reactivity of bifunctional IgGs containing HL-fragments of different types to different antigens, such IgGs may be important in human blood for widening their different biological functions.

Hypogammaglobulinemia in newly diagnosed chronic lymphocytic leukemia: Natural history, clinical correlates, and outcomes.

PubMed

Parikh, Sameer A; Leis, Jose F; Chaffee, Kari G; Call, Timothy G; Hanson, Curtis A; Ding, Wei; Chanan-Khan, Asher A; Bowen, Deborah; Conte, Michael; Schwager, Susan; Slager, Susan L; Van Dyke, Daniel L; Jelinek, Diane F; Kay, Neil E; Shanafelt, Tait D

2015-09-01

Although hypogammaglobulinemia is a well recognized complication in patients with chronic lymphocytic leukemia (CLL), its prevalence at the time of CLL diagnosis, and association with novel prognostic markers and clinical outcome is not well understood. All patients at the Mayo Clinic between January 1999 and July 2013 who had newly diagnosed CLL and had a baseline assessment of serum immunoglobulin G (IgG) were included. The relation between hypogammaglobulinemia at diagnosis and the novel prognostic parameters time to first treatment (TFT) and overall survival (OS) were evaluated. Of 1485 patients who met the eligibility criteria, 382 (26%) had hypogammaglobulinemia (median IgG, 624 mg/dL), whereas the remaining 1103 patients (74%) had normal serum IgG levels (median IgG, 1040 mg/dL). Patients who had hypogammaglobulinemia at diagnosis were more likely to have advanced Rai stage (III-IV; P = .001) and higher expression of CD49d (P < .001) compared with patients who had normal IgG levels. Although the median TFT for patients who had hypogammaglobulinemia was shorter compared with that for patients who had normal IgG levels (3.8 years vs 7.4 years; P < .001), on multivariable analysis, there was no difference in OS between these 2 groups (12.8 years vs 11.3 years, respectively; P = .73). Of 1103 patients who had CLL with normal IgG levels at diagnosis and who did not receive CLL therapy, the risk of acquired hypogammaglobulinemia was 11% at 5 years and 23% at 10 years. Hypogammaglobulinemia is present in 25% of patients with newly diagnosed CLL. Approximately 25% of patients who have CLL with normal IgG levels at diagnosis will subsequently develop hypogammaglobulinemia on long-term follow-up. The presence of hypogammaglobulinemia does not appear to impact overall survival. © 2015 American Cancer Society.

Rationale and pre-clinical efficacy of a novel anti-EMP2 antibody for the treatment of invasive breast cancer

PubMed Central

Fu, Maoyong; Maresh, Erin L.; Helguera, Gustavo F.; Kiyohara, Meagan; Qin, Yu; Ashki, Negin; Daniels-Wells, Tracy R.; Aziz, Najib; Gordon, Lynn K.; Braun, Jonathan; Elshimali, Yahya; Soslow, Robert A.; Penichet, Manuel L.; Goodglick, Lee; Wadehra, Madhuri

2014-01-01

Despite significant advances in biology and medicine, the incidence and mortality due to breast cancer world-wide is still unacceptably high. Thus, there is an urgent need to discover new molecular targets. In this paper, we show evidence for a novel target in human breast cancer, the tetraspan protein epithelial membrane protein-2 (EMP2). Using tissue tumor arrays, protein expression of EMP2 was measured and found to be minimal in normal mammary tissue, but it was upregulated in 63% of invasive breast cancer tumors and in 73% of triple negative tumors tested. To test the hypothesis that EMP2 may be a suitable target for therapy, we constructed a fully human IgG1 antibody specific for a conserved domain of human and murine EMP2. Treatment of breast cancer cells with the anti-EMP2 IgG1 significantly inhibited EMP2 mediated signaling, blocked FAK/Src signaling, inhibited invasion, and promoted apoptosis in vitro. In both human xenograft and syngeneic metastatic tumor monotherapy models, anti-EMP2 IgG1 retarded tumor growth without detectable systemic toxicity. This anti-tumor effect was in part attributable to a potent ADCC response as well as direct cytotoxicity induced by the monoclonal antibody. Together, these results identify EMP2 as a novel therapeutic target for invasive breast cancer. PMID:24448822

Rationale and preclinical efficacy of a novel anti-EMP2 antibody for the treatment of invasive breast cancer.

PubMed

Fu, Maoyong; Maresh, Erin L; Helguera, Gustavo F; Kiyohara, Meagan; Qin, Yu; Ashki, Negin; Daniels-Wells, Tracy R; Aziz, Najib; Gordon, Lynn K; Braun, Jonathan; Elshimali, Yahya; Soslow, Robert A; Penichet, Manuel L; Goodglick, Lee; Wadehra, Madhuri

2014-04-01

Despite significant advances in biology and medicine, the incidence and mortality due to breast cancer worldwide is still unacceptably high. Thus, there is an urgent need to discover new molecular targets. In this article, we show evidence for a novel target in human breast cancer, the tetraspan protein epithelial membrane protein-2 (EMP2). Using tissue tumor arrays, protein expression of EMP2 was measured and found to be minimal in normal mammary tissue, but it was upregulated in 63% of invasive breast cancer tumors and in 73% of triple-negative tumors tested. To test the hypothesis that EMP2 may be a suitable target for therapy, we constructed a fully human immunoglobulin G1 (IgG1) antibody specific for a conserved domain of human and murine EMP2. Treatment of breast cancer cells with the anti-EMP2 IgG1 significantly inhibited EMP2-mediated signaling, blocked FAK/Src signaling, inhibited invasion, and promoted apoptosis in vitro. In both human xenograft and syngeneic metastatic tumor monotherapy models, anti-EMP2 IgG1 retarded tumor growth without detectable systemic toxicity. This antitumor effect was, in part, attributable to a potent antibody-dependent cell-mediated cytotoxicity response as well as direct cytotoxicity induced by the monoclonal antibody. Together, these results identify EMP2 as a novel therapeutic target for invasive breast cancer.

Immunomodulation of human B cells following treatment with intravenous immunoglobulins involves increased phosphorylation of extracellular signal-regulated kinases 1 and 2.

PubMed

Dussault, Nathalie; Ducas, Eric; Racine, Claudia; Jacques, Annie; Paré, Isabelle; Côté, Serge; Néron, Sonia

2008-11-01

In the treatment of autoimmune diseases, intravenous Igs (IVIg) are assumed to modulate immune cells through the binding of surface receptors. IVIg act upon definite human B cell populations to modulate Ig repertoire, and such modulation might proceed through intracellular signaling. However, the heterogeneity of human B cell populations complicates investigations of the intracellular pathways involved in IVIg-induced B cell modulation. The aim of this study was to establish a model allowing the screening of IVIg signal transduction in human B cell lines and to attempt transposing observations made in cell lines to normal human B lymphocytes. Nine human B cell lines were treated with IVIg with the goal of selecting the most suitable model for human B lymphocytes. The IgG(+) DB cell line, whose response was similar to that of human B lymphocytes, showed reduced IVIg modulation following addition of PD98059, an inhibitor of extracellular signal-regulated protein kinase 1/2 (ERK1/2). The IVIg-induced ERK1/2 phosphorylation was indeed proportional to the dosage of monomeric IVIg used when tested on DB cells as well as Pfeiffer cells, another IgG(+) cell line. In addition, two other intermediates, Grb2-associated binder 1 (Gab1) and Akt, showed increased phosphorylation in IVIg-treated DB cells. IVIg induction of ERK1/2 phosphorylation was finally observed in peripheral human B lymphocytes, specifically within the IgG(+) B cell population. In conclusion, IVIg immunomodulation of human B cells can thus be linked to intracellular transduction pathways involving the phosphorylation of ERK1/2, which in combination with Gab1 and Akt, may be related to B cell antigen receptor signaling.

Quantitative analysis of immunoglobulin subclasses and subclass specific glycosylation by LC-MS-MRM in liver disease.

PubMed

Yuan, Wei; Sanda, Miloslav; Wu, Jing; Koomen, John; Goldman, Radoslav

2015-02-26

Aberrant glycosylation of IgGs has been linked to human diseases, including liver disease. In this study, we have quantified plasma immunoglobulins in cirrhosis (CIR) and hepatocellular carcinoma (HCC) and employed a novel LC-MS-MRM assay to quantify glycoforms of IgG subclasses 1-4. Glycan oxonium ions and peptide-GlcNAc fragment ions were utilized to quantify the IgG glycoforms purified by affinity chromatography with normalization to the unique peptide for each IgG subclass. Our results indicate that HCC patients have increased circulating IgG1, IgG3, IgA1, and IgM compared to healthy controls; comparison of HCC and CIR patients shows that HCC patients have significantly higher concentration of IgG1 and IgM but lower concentration of IgG2. An increase in galactose-deficient core fucosylated glycoforms was consistently observed in CIR and HCC patients. The FA2G0 and FA2BG0 glycoforms increase approximately 2-fold in all IgG subclasses accompanied by a decrease in the FA2G2 glycoform. Fucosylation changes are less pronounced but we have detected increased degree of fucosylation in the IgG1 and IgG3 glycoforms. In conclusion, we have optimized a sensitive and selective LC-MS-MRM method for the quantification of immunoglobulin subclasses and their site specific glycoforms, demonstrating that both quantities and glycoforms of immunoglobulins change significantly in liver disease progression to HCC. We have demonstrated that both quantities and glycoforms of immunoglobulin subclasses change significantly in liver disease progression to HCC through quantitative study of immunoglobulin subclasses and their site specific glycoforms using a sensitive and selective LC-MS-MRM method. Redistribution of the glycoforms of specific immunoglobulin subclasses could have important implications for receptor mediated responses affecting the progression of liver disease. Copyright © 2015 Elsevier B.V. All rights reserved.

IgG4 autoantibodies against muscle-specific kinase undergo Fab-arm exchange in myasthenia gravis patients.

PubMed

Koneczny, Inga; Stevens, Jo A A; De Rosa, Anna; Huda, Saif; Huijbers, Maartje G; Saxena, Abhishek; Maestri, Michelangelo; Lazaridis, Konstantinos; Zisimopoulou, Paraskevi; Tzartos, Socrates; Verschuuren, Jan; van der Maarel, Silvère M; van Damme, Philip; De Baets, Marc H; Molenaar, Peter C; Vincent, Angela; Ricciardi, Roberta; Martinez-Martinez, Pilar; Losen, Mario

2017-02-01

Autoimmunity mediated by IgG4 subclass autoantibodies is an expanding field of research. Due to their structural characteristics a key feature of IgG4 antibodies is the ability to exchange Fab-arms with other, unrelated, IgG4 molecules, making the IgG4 molecule potentially monovalent for the specific antigen. However, whether those disease-associated antigen-specific IgG4 are mono- or divalent for their antigens is unknown. Myasthenia gravis (MG) with antibodies to muscle specific kinase (MuSK-MG) is a well-recognized disease in which the predominant pathogenic IgG4 antibody binds to extracellular epitopes on MuSK at the neuromuscular junction; this inhibits a pathway that clusters the acetylcholine (neurotransmitter) receptors and leads to failure of neuromuscular transmission. In vitro Fab-arm exchange-inducing conditions were applied to MuSK antibodies in sera, purified IgG4 and IgG1-3 sub-fractions. Solid-phase cross-linking assays were established to determine the extent of pre-existing and inducible Fab-arm exchange. Functional effects of the resulting populations of IgG4 antibodies were determined by measuring inhibition of agrin-induced AChR clustering in C2C12 cells. To confirm the results, κ/κ, λ/λ and hybrid κ/λ IgG4s were isolated and tested for MuSK antibodies. At least fifty percent of patients had IgG4, but not IgG1-3, MuSK antibodies that could undergo Fab-arm exchange in vitro under reducing conditions. Also MuSK antibodies were found in vivo that were divalent (monospecific for MuSK). Fab-arm exchange with normal human IgG4 did not prevent the inhibitory effect of serum derived MuSK antibodies on AChR clustering in C2C12 mouse myotubes. The results suggest that a considerable proportion of MuSK IgG4 could already be Fab-arm exchanged in vivo. This was confirmed by isolating endogenous IgG4 MuSK antibodies containing both κ and λ light chains, i.e. hybrid IgG4 molecules. These new findings demonstrate that Fab-arm exchanged antibodies are pathogenic. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Intravenous immunoglobulin therapy for severe Clostridium difficile colitis

PubMed Central

Salcedo, J; Keates, S; Pothoulakis, C; Warny, M; Castagliuolo, I; LaMont, J; Kelly, C

1997-01-01

Background—Many individuals have serum antibodies against Clostridium difficile toxins. Those with an impaired antitoxin response may be susceptible to recurrent, prolonged, or severe C difficile diarrhoea and colitis. 
Aims—To examine whether treatment with intravenous immunoglobulin might be effective in patients with severe pseudomembranous colitis unresponsive to standard antimicrobial therapy. 
Patients—Two patients with pseudomembranous colitis not responding to metronidazole and vancomycin were given normal pooled human immunoglobulin intravenously (200-300 mg/kg). 
Methods—Antibodies against C difficile toxins were measured in nine immunoglobulin preparations by ELISA and by cytotoxin neutralisation assay. 
Results—Both patients responded quickly as shown by resolution of diarrhoea, abdominal tenderness, and distension. All immunoglobulin preparations tested contained IgG against C difficile toxins A and B by ELISA and neutralised the cytotoxic activity of C difficile toxins in vitro at IgG concentrations of 0.4-1.6 mg/ml. 
Conclusion—Passive immunotherapy with intravenous immunoglobulin may be a useful addition to antibiotic therapy for severe, refractory C difficile colitis. IgG antitoxin is present in standard immunoglobulin preparations and C difficile toxin neutralising activity is evident at IgG concentrations which are readily achieved in the serum by intravenous immunoglobulin administration. 

 Keywords: Clostridium difficile; toxin; diarrhoea; IgG; immunotherapy; antibiotic PMID:9378393

Characterization of antibodies against ferret immunoglobulins, cytokines and CD markers.

PubMed

Martel, Cyril Jean-Marie; Aasted, Bent

2009-12-15

Ferret IgG and IgM were purified from normal serum, while ferret IgA was purified from bile. The estimated molecular weights of the immunoglobulin gamma, alpha and mu heavy chains were found to be 54kDa, 69kDa and 83kDa, respectively. For immunological (ELISA) quantification of ferret immunoglobulins, we identified and characterized polyclonal antibodies towards ferret IgG, IgM and IgA. We also identified 22 monoclonal antibodies (mAbs) raised mostly against human CD markers which cross-reacted with ferret leukocytes. These antibodies were originally specific against human CD8, CD9, CD14, CD18, CD25, CD29, CD32, CD44, CD61, CD71, CD79b, CD88, CD104, CD172a and mink CD3. Finally, we identified 4 cross-reacting mAbs with specificities against ferret interferon-gamma, TNF-alpha, interleukin-4 and interleukin-8.

Subclass specificities of rabbit antibodies to human antidextran.

PubMed

Outschoorn, I M

1983-03-01

Rabbits were immunized with purified antidextran containing IgG2. Half of the animals were treated with commercial human IgG intravenously to induce tolerance. The antisera were absorbed and/or eluted from IgG-Sepharose columns and the antibodies tested with a panel of at least eight human myeloma proteins of the four IgG subclasses, both kappa and lambda types. All animals produced mainly anti-IgG2 or IgG4, sometimes intechanged between these maxima or between kappa and lambda types over a series of bleedings. Absorption with IgG2 and/or IgG4 myeloma proteins resulted in sera or antibody preparations specific for the IgG1 or IgG3 subclasses, and the amount of those antibodies also varied between bleedings from the same animal. It may be concluded that anti-IgG2 and anti-IgG4 syntheses are related in a complementary manner or are equally likely to be produced in a response to IgG2; while IgG1 and IgG3 are also interrelated, but with an inverse relationship to IgG2 and IgG4. Alternatively anti-IgG2 and anti-IgG4 antibodies could be highly cross-reactive, and so could anti-IgG1 and anti-IgG3 antibodies.

Subclass specificities of rabbit antibodies to human antidextran.

PubMed Central

Outschoorn, I M

1983-01-01

Rabbits were immunized with purified antidextran containing IgG2. Half of the animals were treated with commercial human IgG intravenously to induce tolerance. The antisera were absorbed and/or eluted from IgG-Sepharose columns and the antibodies tested with a panel of at least eight human myeloma proteins of the four IgG subclasses, both kappa and lambda types. All animals produced mainly anti-IgG2 or IgG4, sometimes intechanged between these maxima or between kappa and lambda types over a series of bleedings. Absorption with IgG2 and/or IgG4 myeloma proteins resulted in sera or antibody preparations specific for the IgG1 or IgG3 subclasses, and the amount of those antibodies also varied between bleedings from the same animal. It may be concluded that anti-IgG2 and anti-IgG4 syntheses are related in a complementary manner or are equally likely to be produced in a response to IgG2; while IgG1 and IgG3 are also interrelated, but with an inverse relationship to IgG2 and IgG4. Alternatively anti-IgG2 and anti-IgG4 antibodies could be highly cross-reactive, and so could anti-IgG1 and anti-IgG3 antibodies. PMID:6186599

Anti-myeloperoxidase autoantibodies react with native but not denatured myeloperoxidase.

PubMed Central

Falk, R J; Becker, M; Terrell, R; Jennette, J C

1992-01-01

We wondered whether anti-myeloperoxidase (MPO) autoantibodies (MPO-ANCA) found in patients with systemic vasculitis react with a conformational epitope or epitopes on the MPO molecule. Sera from 15 human MPO-ANCA, and a polyclonal and a monoclonal anti-MPO antibodies were reacted with MPO in native and denatured states. Human MPO-ANCA and mouse monoclonal anti-MPO reacted with native MPO, and a 120-kD band representing the MPO hologenzyme, but not with denatured MPO fragments; however, MPO-ANCA and mouse anti-MPO did not demonstrate competitive inhibition of binding to MPO. Polyclonal rabbit anti-MPO reacted with both native and denatured MPO. All MPO-ANCA tested showed the same patterns of reactivity with native and denatured MPO in dot blot and Western blot analyses. Both polyclonal and monoclonal anti-MPO antibodies inhibited MPO's protein iodination by over 90%, whereas MPO-ANCA IgGs, normal IgGs and disease control IgGs did not. These data suggest that (i) MPO-ANCA interact with a conformational epitope on the MPO molecule; and (ii) MPO-ANCA from different patients have similar reactivity with native versus denatured MPO. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:1379133

Demonstration of IgG Subclass (IgG1 and IgG3) in Immuno-Related Hemocytopenia.

PubMed

Shao, Yuanyuan; Qi, Xiao; Fu, Rong; Liu, Hui; Wang, Yihao; Ding, Shaoxue; Wang, Huaquan; Li, Lijuan; Shao, Zonghong

2018-06-01

Immuno-related hemocytopenia (IRH) is defined as idiopathic cytopenia of undetermined significance (ICUS) patients with autoantibodies. In our previous studies, we found that IgG1 levels were increased in IRH patients and might cause the destruction of hematopoietic cells. In this study, we analyzed IgG subclasses in 30 IRH patients (male:female = 13:17, median age 32 years, range 18 - 56), 15 IRH remission patients (IRH-R) (male:female = 6:9, median age 34, range 20 - 52) and 20 normal controls (male:female = 8:12, median age 27, range 24 - 36) by Cytometric Bead Array, Flow Cytometry and Immunohistochemical staining. Levels of IgG1/IgG3 in the bone marrow supernatant of IRH patents, as well as the proportion of CD5+ B lymphocytes and Th2 cells (CD3+CD8-IL-4+) were higher than those of IRH-R patients and normal controls, and IgG1 levels had a positive correlation with the proportion of Th2 cells. In IRH patients, IgG1 and IgG3 were positive on nucleated erythrocytes and granulocytes, which were negative in IRH-R patients and healthy controls and had inverse correlations with hematopoietic function. Using immunohistochemical staining, IgG1 were also detected on bone marrow biopsies of IRH patients. The results indicated that IgG1 and IgG3 autoantibodies in IRH patients might play a key role in the IRH pathogenesis and in the abnormal immune function of IRH patients.

Importance of IgG subclasses of anti-Rh antibodies for the detection of Fc-receptor-bearing human lymphocytes.

PubMed

Zupańska, B; Maślanka, K; van Loghem, E

1982-11-01

13 anti-Rh sera were compared for their usefulness in the detection of Fc-receptor-bearing lymphocytes (EAhum test). IgG subclasses of anti-Rh antibodies were determined by the antiglobulin test with monospecific sera and by the detection of Gm allotypic markers in the haemagglutination inhibition test. Six sera with IgG1 + IgG3 or IgG1 + IgG2 + IgG3 antibodies and one with pure IgG3 antibodies were found to be useful, whereas six other sera with only IgG1 were unsuitable for the EAhum test. G3m markers were detected only on the anti-Rh antibodies which were capable of forming rosettes with lymphocytes. The data show that human peripheral lymphocytes possess Fc receptors for IgG3 immunoglobulins.

Nephropathy associated with sickle cell anemia: an autologous immune complex nephritis. I. Studies on nature of glomerular-bound antibody and antigen identification in a patient with sickle cell disease and immune deposit glomerulonephritis.

PubMed

Strauss, J; Pardo, V; Koss, M N; Griswold, W; McIntosh, R M

1975-03-01

The nature of the glomerular-bound antibody and the putative antigen was investigated in one of the patients with sickle cell disease and immune deposit membranoproliferative glomerulonephritis by immunohistologic and glomerular antibody elution. Renal proximal tubular epithelial antigen was localized in association with immunoglobulins G (IgG), M (IgM), Clq fraction of the first component of complement (Clq) and the third component of complement (C3) in a granular pattern along the glomerular basement membrane of the patient's kidney. IgG and IgM were eluted from glomeruli. These immunoglobulins fixed to the proximal tubules of normal human kidney by direct immunofluorescence. This localization was abolished by absorption of the eluted immunoglobulins with renal tubular epithelial (RTE) antigen. The IgG eluted from the glomeruli blocked the fixation of rabbit anti-RTE antigen to normal proximal tubular brush border. These studies suggest that the nephritis in this patient was due to deposition of complexes or RTE antigen and specific antibody. An autologous immune complex nephritis may develop in some patients with sickle cell anemia secondary to RTE antigen released possibly after renal ischemia or some other phenomenon causing renal tubular damage.

Human placenta: relative content of antibodies of different classes and subclasses (IgG1-IgG4) containing lambda- and kappa-light chains and chimeric lambda-kappa-immunoglobulins.

PubMed

Lekchnov, Evgenii A; Sedykh, Sergey E; Dmitrenok, Pavel S; Buneva, Valentina N; Nevinsky, Georgy A

2015-06-01

The specific organ placenta is much more than a filter: it is an organ that protects, feeds and regulates the growth of the embryo. Affinity chromatography, ELISA, SDS-PAGE and matrix-assisted laser desorption ionization mass spectrometry were used. Using 10 intact human placentas deprived of blood, a quantitative analysis of average relative content [% of total immunoglobulins (Igs)] was carried out for the first time: (92.7), IgA (2.4), IgM (2.5), kappa-antibodies (51.4), lambda-antibodies (48.6), IgG1 (47.0), IgG2 (39.5), IgG3 (8.8) and IgG4 (4.3). It was shown for the first time that placenta contains sIgA (2.5%). In the classic paradigm, Igs represent products of clonal B-cell populations, each producing antibodies recognizing a single antigen. There is a common belief that IgGs in mammalian biological fluids are monovalent molecules having stable structures and two identical antigen-binding sites. However, similarly to human milk Igs, placenta antibodies undergo extensive half-molecule exchange and the IgG pool consists of 43.5 ± 15.0% kappa-kappa-IgGs and 41.6 ± 17.0% lambda-lambda-IgGs, while 15.0 ± 4.0% of the IgGs contained both kappa- and lambda-light chains. Kappa-kappa-IgGs and lambda-lambda-IgGs contained, respectively (%): IgG1 (47.7 and 34.4), IgG2 (36.3 and 44.5), IgG3 (7.4 and 11.8) and IgG4 (7.5 and 9.1), while chimeric kappa-lambda-IgGs consisted of (%): 43.5 IgG1, 41.0 IgG2, 5.6 IgG3 and 7.9 IgG4. Our data are indicative of the possibility of half-molecule exchange between placenta IgGs of various subclasses, raised against different antigens, which explains a very well-known polyspecificity and cross-reactivity of different human IgGs. © The Japanese Society for Immunology. 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Structural characterization of the Man5 glycoform of human IgG3 Fc

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shah, Ishan S.; Lovell, Scott; Mehzabeen, Nurjahan

Immunoglobulin G (IgG) consists of four subclasses in humans: IgG1, IgG2, IgG3 and IgG4, which are highly conserved but have unique differences that result in subclass-specific effector functions. Though IgG1 is the most extensively studied IgG subclass, study of other subclasses is important to understand overall immune function and for development of new therapeutics. When compared to IgG1, IgG3 exhibits a similar binding profile to Fcγ receptors and stronger activation of complement. All IgG subclasses are glycosylated at N297, which is required for Fcγ receptor and C1q complement binding as well as maintaining optimal Fc conformation. We have determined themore » crystal structure of homogenously glycosylated human IgG3 Fc with a GlcNAc2Man5 (Man5) high mannose glycoform at 1.8 Å resolution and compared its structural features with published structures from the other IgG subclasses. Although the overall structure of IgG3 Fc is similar to that of other subclasses, some structural perturbations based on sequence differences were revealed. For instance, the presence of R435 in IgG3 (and H435 in the other IgG subclasses) has been implicated to result in IgG3-specific properties related to binding to protein A, protein G and the neonatal Fc receptor (FcRn). The IgG3 Fc structure helps to explain some of these differences. Additionally, protein-glycan contacts observed in the crystal structure appear to correlate with IgG3 affinity for Fcγ receptors as shown by binding studies with IgG3 Fc glycoforms. Finally, this IgG3 Fc structure provides a template for further studies aimed at engineering the Fc for specific gain of function.« less

Frequency and genotype of human parvovirus B19 among Iranian patients infected with HIV.

PubMed

Azadmanesh, Kayhan; Mohraz, Minoo; Kazemimanesh, Monireh; Aghakhani, Arezoo; Foroughi, Maryam; Banifazl, Mohammad; Eslamifar, Ali; Ramezani, Amitis

2015-07-01

The human parvovirus B19 (B19) usually causes a subclinical infection in immunocompetent individuals. Whereas immunocompromised individuals such as patients infected with HIV are at risk of persistent anemia due to B19 infection. Only few studies have been carried out on distribution and molecular epidemiology of B19 in Iran. We aimed to determine the frequency and genotype of B19 among Iranian patients infected with HIV. We conducted a survey on 99 HIV patients and 64 healthy controls. IgG and IgM antibodies against B19 were detected by ELISA and B19 DNA was assessed by nested PCR. PCR products were subjected to direct sequencing and classified after phylogenetic analysis. The prevalence of B19 immunoglobulin was 11.1% for IgG and 1% for IgM. B19 DNA was detected in 13.1% of cases. The prevalence of B19 IgG, IgM, and DNA in control group was 25%, 1.6%, and 9.4%, respectively. B19 IgG was significantly lower in HIV group than in normal controls. There was no significant difference regarding anemia between cases and controls. All sequenced B19 isolates belonged to genotype 1A with low genetic diversity. Our findings indicated that in the HAART era, the importance of B19 infections in HIV patients may be limited whereas persistent B19 viremia in the circulation of healthy controls raises a potential concern in blood donations. © 2015 Wiley Periodicals, Inc.

Human IgG is produced in a pro-form that requires clipping of C-terminal lysines for maximal complement activation

PubMed Central

van den Bremer, Ewald TJ; Beurskens, Frank J; Voorhorst, Marleen; Engelberts, Patrick J; de Jong, Rob N; van der Boom, Burt G; Cook, Erika M; Lindorfer, Margaret A; Taylor, Ronald P; van Berkel, Patrick HC; Parren, Paul WHI

2015-01-01

Human IgG is produced with C-terminal lysines that are cleaved off in circulation. The function of this modification was unknown and generally thought not to affect antibody function. We recently reported that efficient C1q binding and complement-dependent cytotoxicity (CDC) requires IgG hexamerization at the cell surface. Here we demonstrate that C-terminal lysines may interfere with this process, leading to suboptimal C1q binding and CDC of cells opsonized with C-terminal lysine-containing IgG. After we removed these lysines with a carboxypeptidase, maximal complement activation was observed. Interestingly, IgG1 mutants containing either a negative C-terminal charge or multiple positive charges lost CDC almost completely; however, CDC was fully restored by mixing C-terminal mutants of opposite charge. Our data indicate a novel post-translational control mechanism of human IgG: human IgG molecules are produced in a pro-form in which charged C-termini interfere with IgG hexamer formation, C1q binding and CDC. To allow maximal complement activation, C-terminal lysine processing is required to release the antibody's full cytotoxic potential. PMID:26037225

Absolute Quantitation of Glycoforms of Two Human IgG Subclasses Using Synthetic Fc Peptides and Glycopeptides

NASA Astrophysics Data System (ADS)

Roy, Rini; Ang, Evelyn; Komatsu, Emy; Domalaon, Ronald; Bosseboeuf, Adrien; Harb, Jean; Hermouet, Sylvie; Krokhin, Oleg; Schweizer, Frank; Perreault, Hélène

2018-05-01

Immunoglobulins, such as immunoglobulin G (IgG), are of prime importance in the immune system. Polyclonal human IgG comprises four subclasses, of which IgG1 and IgG2 are the most abundant in healthy individuals. In an effort to develop an absolute MALDI-ToF-MS quantitative method for these subclasses and their Fc N-glycoforms, (glyco)peptides were synthesized using a solid-phase approach and used as internal standards. Tryptic digest glycopeptides from monoclonal IgG1 and IgG2 samples were first quantified using EEQYN(GlcNAc)STYR and EEQFN(GlcNAc)STFR standards, respectively. For IgG1, a similar glycopeptide where tyrosine (Y) was isotopically labelled was used to quantify monoclonal IgG1 that had been treated with the enzyme Endo-F2, i.e., yielding tryptic glycopeptide EEQYN(GlcNAc)STYR. The next step was to quantify single subclasses within polyclonal human IgG samples. Although ion abundances in the MALDI spectra often showed higher signals for IgG2 than IgG1, depending on the spotting solvent used, determination of amounts using the newly developed quantitative method allowed to obtain accurate concentrations where IgG1 species were predominant. It was observed that simultaneous analysis of IgG1 and IgG2 yielded non-quantitative results and that more success was obtained when subclasses were quantified one by one. More experiments served to assess the respective extraction and ionization efficiencies of EEQYNSTYR/EEQFNSTFR and EEQYN(GlcNAc)STYR/EEQFN(GlcNAc)STFR mixtures under different solvent and concentration conditions.

Quantitation of IgG kappa and IgG lambda in the cerebrospinal fluid by sandwich ELISA method.

PubMed

Zeman, David; Kušnierová, Pavlína; Bojková, Jana; Všianský, František; Zapletalová, Olga

2017-01-01

IgG kappa and IgG lambda concentrations were quantified in 96 paired CSF and sera using Hevylite™ antibodies in an in-house developed sandwich ELISA method. In 56 of these samples, the results were compared with a qualitative isoelectric focusing/affinity-mediated immunoblotting assay for oligoclonal IgG kappa and IgG lambda. Normal IgG kappa/lambda ratio in the CSF was the same as in serum. In 19/33 patients with intrathecal oligoclonal IgG synthesis, skewed IgG kappa/lambda ratio was observed (increased in 16 and decreased in 3 cases). The analysis of light chain composition of intrathecally synthesised immunoglobulins could contribute to our understanding of intrathecal humoral immune response, although its diagnostic utility is limited.

IL-27 induces the production of IgG1 by human B cells.

PubMed

Boumendjel, Amel; Tawk, Lina; Malefijt, René de Waal; Boulay, Vera; Yssel, Hans; Pène, Jérôme

2006-12-01

It has been reported that IL-27 specifically induces the production of IgG2a by mouse B cells and inhibits IL-4-induced IgG1 synthesis. Here, we show that human naïve cord blood expresses a functional IL-27 receptor, consisting of the TCCR and gp130 subunits, although at lower levels as compared to naïve and memory splenic B cells. IL-27 does not induce proliferative responses and does not increase IgG1 production by CD19(+)CD27(+) memory B cells. However, it induces a low, but significant production of IgG1 by naïve CD19(+)CD27(-)IgD(+)IgG(-) spleen and cord blood B cells, activated via CD40, whereas it has no effect on the production of the other IgG subclasses. In addition, IL-27 induces the differentiation of a population of B cells that express high levels of CD38, in association with a down-regulation of surface IgD expression, and that are surface IgG(+/int), CD20(low), CD27(high), indicating that IL-27 promotes isotype switching and plasma cell differentiation of naive B cells. However, as compared to the effects of IL-21 and IL-10, both switch factors for human IgG1 and IgG3, those of IL-27 are modest and regulate exclusively the production of IgG1. Finally, although IL-27 has no effect on IL-4 and anti-CD40-induced Cepsilon germline promoter activity, it up-regulates IL-4-induced IgE production by naive B cells. These results point to a partial redundancy of switch factors regulating the production of IgG1 in humans, and furthermore indicate the existence of a common regulation of the human IgG1and murine IgG2a isotypes by IL-27.

[IgG4-related disease: patient group characterization and rituximab therapy].

PubMed

Sedyshev, S Kh; Vasil'ev, V I; Kovrigina, A M; Logvinenko, O A; Rodionova, E B; Safonova, T N; Gaĭduk, I V; Silin, A Iu; Komov, D V; Nasonov, E L

2013-01-01

To characterize a group of patients with IgG4-related disease (IgG4-RD) in a Russian population and to evaluate the efficiency of rituximab therapy. In 2009 to 2011, at the Research Institute of Rheumatology, Russian Academy of Medical Sciences, 30 patients (16 men and 14 women; mean age 44 years) were diagnosed with IgG4-RD that was confirmed by determination of serum IgG4 levels and immunohistochemical study of biopsy samples stained for IgG4-positive plasma cells. Seven patients received rituximab therapy. It was assumed at baseline that there were different types of neoplasias in 12 (40%), non-Hodgkin's and Hodgkin's lymphomas in 10 (33.3%), Sjögren's syndrome in 5 (16.7%), and Wegener's granulomatosis in 3 (10%). When 2 or more locations were involved, the condition was regarded as multifocal fibrosclerosis (33.3%). Localized forms were revealed in 20 (66.7%) patients. Among them, the largest number of patients was those who had orbital pseudotumor, Mikulicz's disease, or retroperitoneal fibrosclerosis. The most common sites of involvement were orbits (66.7%), salivary glands (70%) and lymph nodes (36.7%). Comparison of serum IgG4 levels in 28 patients with IgG4-RD, 22 patients with Sjögren's disease, salivary and lacrimal gland lymphomas, and 10 healthy controls showed that the concentration of IgG4 was significantly higher in Group 1 (median 2.6 g/I; IQR 1.22-4.65 (p < 0.001). Tissue IgG4/IgG ratio varied from 25 to 50% and averaged 38%. A moiré-like pattern of varying fibrosis was noted in 83% of cases. Analysis of laboratory data revealed elevated C-reactive protein concentrations (46.7% with a mean of 39.5 mg/l; normal values < 5.0 mg/l), increased erythrocyte sedimentation rate (60% with a mean of 37.6 mm/h), hypergammaglobulinemia (30% with a mean of 29.4%; normal range 13-22%), and rheumatoid factor (23.3%). After rituximab therapy, all the patients showed a decrease of IgG4 levels to the normal levels and positive changes evidenced by visualization techniques (computed tomography, magnetic resonance imaging). IgG4-RD is a novel problem in modern medicine, which requires a multidisciplinary approach and further study. Rituximab therapy is a promising treatment.

Human IgG1 antibodies suppress angiogenesis in a target-independent manner

PubMed Central

Bogdanovich, Sasha; Kim, Younghee; Mizutani, Takeshi; Yasuma, Reo; Tudisco, Laura; Cicatiello, Valeria; Bastos-Carvalho, Ana; Kerur, Nagaraj; Hirano, Yoshio; Baffi, Judit Z; Tarallo, Valeria; Li, Shengjian; Yasuma, Tetsuhiro; Arpitha, Parthasarathy; Fowler, Benjamin J; Wright, Charles B; Apicella, Ivana; Greco, Adelaide; Brunetti, Arturo; Ruvo, Menotti; Sandomenico, Annamaria; Nozaki, Miho; Ijima, Ryo; Kaneko, Hiroki; Ogura, Yuichiro; Terasaki, Hiroko; Ambati, Balamurali K; Leusen, Jeanette HW; Langdon, Wallace Y; Clark, Michael R; Armour, Kathryn L; Bruhns, Pierre; Verbeek, J Sjef; Gelfand, Bradley D; De Falco, Sandro; Ambati, Jayakrishna

2016-01-01

Aberrant angiogenesis is implicated in diseases affecting nearly 10% of the world’s population. The most widely used anti-angiogenic drug is bevacizumab, a humanized IgG1 monoclonal antibody that targets human VEGFA. Although bevacizumab does not recognize mouse Vegfa, it inhibits angiogenesis in mice. Here we show bevacizumab suppressed angiogenesis in three mouse models not via Vegfa blockade but rather Fc-mediated signaling through FcγRI (CD64) and c-Cbl, impairing macrophage migration. Other approved humanized or human IgG1 antibodies without mouse targets (adalimumab, alemtuzumab, ofatumumab, omalizumab, palivizumab and tocilizumab), mouse IgG2a, and overexpression of human IgG1-Fc or mouse IgG2a-Fc, also inhibited angiogenesis in wild-type and FcγR humanized mice. This anti-angiogenic effect was abolished by Fcgr1 ablation or knockdown, Fc cleavage, IgG-Fc inhibition, disruption of Fc-FcγR interaction, or elimination of FcRγ-initated signaling. Furthermore, bevacizumab’s Fc region potentiated its anti-angiogenic activity in humanized VEGFA mice. Finally, mice deficient in FcγRI exhibited increased developmental and pathological angiogenesis. These findings reveal an unexpected anti-angiogenic function for FcγRI and a potentially concerning off-target effect of hIgG1 therapies. PMID:26918197

Chimeric Anti-Human Podoplanin Antibody NZ-12 of Lambda Light Chain Exerts Higher Antibody-Dependent Cellular Cytotoxicity and Complement-Dependent Cytotoxicity Compared with NZ-8 of Kappa Light Chain.

PubMed

Kaneko, Mika K; Abe, Shinji; Ogasawara, Satoshi; Fujii, Yuki; Yamada, Shinji; Murata, Takeshi; Uchida, Hiroaki; Tahara, Hideaki; Nishioka, Yasuhiko; Kato, Yukinari

2017-02-01

Podoplanin (PDPN), a type I transmembrane 36-kDa glycoprotein, is expressed not only in normal cells, such as renal epithelial cells (podocytes), lymphatic endothelial cells, and pulmonary type I alveolar cells, but also in cancer cells, including brain tumors and lung squamous cell carcinomas. Podoplanin activates platelet aggregation by binding to C-type lectin-like receptor-2 (CLEC-2) on platelets, and the podoplanin/CLEC-2 interaction facilitates blood/lymphatic vessel separation. We previously produced neutralizing anti-human podoplanin monoclonal antibody (mAb), clone NZ-1 (rat IgG 2a , lambda), which neutralizes the podoplanin/CLEC-2 interaction and inhibits platelet aggregation and cancer metastasis. Human-rat chimeric antibody, NZ-8, was previously developed using variable regions of NZ-1 and human constant regions of heavy chain (IgG 1 ) and light chain (kappa chain). Although NZ-8 showed high antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) against human podoplanin-expressing cancer cells, the binding affinity of NZ-8 was lower than that of NZ-1. Herein, we produced a novel human-rat chimeric antibody, NZ-12, the constant regions of which consist of IgG 1 heavy chain and lambda light chain. Using flow cytometry, we demonstrated that the binding affinity of NZ-12 was much higher than that of NZ-8. Furthermore, ADCC and CDC activities of NZ-12 were significantly increased against glioblastoma cell lines (LN319 and D397) and lung cancer cell line (PC-10). These results suggested that NZ-12 could become a promising therapeutic antibody against podoplanin-expressing brain tumors and lung cancers.

Strategies for the depyrogenation of contaminated immunoglobulin G solutions by histidine-immobilized hollow fiber membrane.

PubMed

Legallais, C; Anspach, F B; Bueno, S M; Haupt, K; Vijayalakshmi, M A

1997-03-28

The depyrogenation of different IgG solutions using the histidine-linked hollow fiber membrane developed in our laboratory is presented here. Three strategies for endotoxin (ET) removal were investigated according to the immobilized histidine's ability to bind different immunoglobulins: (1) ET removal from 1 mg/ml non histidine-binding mouse monoclonal IgG1 (MabCD4) solution was achieved in the presence of acetate buffer (pH 5.0) without any protein loss. (2) For contaminated human IgG, combined adsorption of ET and IgG in the presence of MOPS of Tris buffer was tested, followed by differential elution using increasing salt concentrations. This attempt was not successful since ET were quantitatively found in the IgG elution fraction. (3) Alternatively, it was proposed to adsorb selectively ET in the presence of acetate buffer (pH 5.0) under non binding conditions for human IgG. Human IgG could then be purified if necessary with the same membrane in the presence of MOPS buffer (pH 6.5). With a 1 m2 histidine-PEVA module under these operating conditions, it is estimated that the depyrogenation of 3 l of 1 mg/ml IgG (human or murine) solution containing 80 EU/ml of ET should be possible.

Highly sensitive detection of human IgG using a novel bio-barcode assay combined with DNA chip technology

NASA Astrophysics Data System (ADS)

Liu, Zhenbao; Zhou, Bo; Wang, Haiqing; Lu, Feng; Liu, Tianjun; Song, Cunxian; Leng, Xigang

2013-09-01

A simple and ultrasensitive detection of human IgG based on signal amplification using a novel bio-barcode assay and DNA chip technology was developed. The sensing platform was a sandwich system made up of antibody-modified magnetic microparticles (Ab-MMPs)/human IgG/Cy3-labeled single-stranded DNA and antibody-modified gold nanoparticles (Cy3-ssDNA-Ab-AuNPs). The MMPs (2.5 μm in diameter) modified with mouse anti-human IgG monoclonal-antibodies could capture human IgG and further be separated and enriched via a magnetic field. The AuNPs (13 nm in diameter) conjugated with goat anti-human IgG polyclonal-antibodies and Cy3-ssDNA could further combine with the human IgG/Ab-MMP complex. The Cy3-ssDNA on AuNPs was then released by TCEP to hybridize with the DNA chip, thus generating a detectable signal by the fluorescence intensity of Cy3. In order to improve detection sensitivity, a three-level cascaded signal amplification was developed: (1) The MMP enrichment as the first-level; (2) Large quantities of Cy3-ssDNA on AuNPs as the second-level; (3) The Cy3-ssDNA conjugate with DNA chip as the third-level. The highly sensitive technique showed an increased response of the fluorescence intensity to the increased concentration of human IgG through a detection range from 1 pg mL-1 to 10 ng mL-1. This sensing technique could not only improve the detection sensitivity for the low concentration of human IgG but also present a robust and efficient signal amplification model. The detection method has good stability, specificity, and reproducibility and could be applied in the detection of human IgG in the real samples.

First Attempt To Validate Human IgG Antibody Response to Nterm-34kDa Salivary Peptide as Biomarker for Evaluating Exposure to Aedes aegypti Bites

PubMed Central

Elanga Ndille, Emmanuel; Doucoure, Souleymane; Damien, Georgia; Mouchet, François; Drame, Papa Makhtar; Cornelie, Sylvie; Noukpo, Herbert; Yamadjako, Sandra; Djenontin, Armel; Moiroux, Nicolas; Misse, Dorothee; Akogbeto, Martin; Corbel, Vincent; Henry, Marie-Claire; Chandre, Fabrice; Baldet, Thierry; Remoue, Franck

2012-01-01

Background Much effort is being devoted for developing new indicators to evaluate the human exposure to Aedes mosquito bites and the risk of arbovirus transmission. Human antibody (Ab) responses to mosquito salivary components could represent a promising tool for evaluating the human-vector contact. Methodology/Principal findings To develop a specific biomarker of human exposure to Aedes aegypti bites, we measured IgG Ab response to Ae. aegypti Nterm-34 kDa salivary peptide in exposed children in 7 villages of Southern Benin (West Africa). Results showed that specific IgG response presented high inter-individual heterogeneity between villages. IgG response was associated with rainfall and IgG level increased from dry (low exposure) to rainy (high exposure) seasons. These findings indicate that IgG Ab to Nterm-34 kDa salivary peptide may represent a reliable biomarker to detect variation in human exposure to Ae. aegypti bites. Conclusion/Significance This preliminary study highlights the potential use of Ab response to this salivary peptide for evaluating human exposure to Ae. aegypti. This biomarker could represent a new promising tool for assessing the risk of arbovirus transmission and for evaluating the efficacy of vector control interventions. PMID:23166852

IgG subclass reactivity to human cardiac myosin in cardiomyopathy patients is indicative of a Th1-like autoimmune disease

PubMed Central

Skyllouriotis, P; Skyllouriotis-Lazarou, M; Natter, S; Steiner, R; Spitzauer, S; Kapiotis, S; Valent, P; Hirschl, A M; Guber, S E; Laufer, G; Wollenek, G; Wolner, E; Wimmer, M; Valenta, R

1999-01-01

Studies performed in mice together with the demonstration of increased levels of heart-specific autoantibodies, cytokines and cytokine receptors in sera from cardiomyopathy (CMP) patients argued for a pathogenic role of autoimmune mechanisms in CMP. This study was designed to analyse the presence of IgG anti-heart antibodies in sera from patients suffering from hypertrophic and dilatative forms of CMP as well as from patients with ischaemic heart disease and healthy individuals. Patients' sera were analysed for IgG reactivity to Western-blotted extracts prepared from human epithelial and endothelial cells, heart and skeletal muscle specimens as well as from Streptococcus pyogenes. The IgG subclass (IgG1–4) reactivity to purified human cardiac myosin was analysed by ELISA. While sera from CMP patients and healthy individuals displayed comparable IgG reactivity to a variety of human proteins, cardiac myosin represented the prominent antigen detected strongly and preferentially by sera from CMP patients. Pronounced IgG anti-cardiac myosin reactivity was frequently found in sera from patients with dilatative CMP and reduced ventricular function. ELISA analyses revealed a prominent IgG2/IgG3 anti-cardiac myosin reactivity in CMP sera, indicating a preferential Th1-like immune response. Elevated anti-cytomegalovirus, anti-enterovirus IgG titres as well as IgG reactivity to nitrocellulose-blotted S. pyogenes proteins were also frequently observed in the group of CMP patients. If further work can support the hypothesis that autoreactivity to cardiac myosin represents a pathogenic factor in CMP, specific immunomodulation of this Th1- towards a Th2-like immune response may represent a promising therapeutic strategy for CMP. PMID:9933448

A comparative study of the N-linked oligosaccharide structures of human IgG subclass proteins.

PubMed Central

Jefferis, R; Lund, J; Mizutani, H; Nakagawa, H; Kawazoe, Y; Arata, Y; Takahashi, N

1990-01-01

Quantitative oligosaccharide profiles were determined for each of 18 human IgG paraproteins representing the four subclasses. Each paraprotein exhibits a unique profile that may be substantially different from that observed for polyclonal IgG. The IgG2 and some IgG3 proteins analysed exhibit a predominance of oligosaccharide moieties having galactose on the Man(alpha 1----3) arm rather than the Man(alpha 1----6) arm; it was previously held that galactosylation of the Man(alpha 1----6) arm is preferred, as observed for IgG1, IgG4 and polyclonal IgG. An IgG4 protein is reported that has galactosylated Man(alpha 1----3) and Man(alpha 1----6) arms on both Fc-localized carbohydrate moieties; previous findings suggested that such fully glycosylated structures could not be accommodated within the internal space of the C gamma 2 domains. Unusual monoantennary oligosaccharides present in IgG2 and IgG3 proteins were isolated and their structures determined. Images Fig. 1. PMID:2363690

Significant increase in IgG4+ plasma cells in gastric biopsy specimens from patients with pernicious anaemia.

PubMed

Bedeir, Ahmed S; Lash, Richard H; Lash, Jonathan G; Ray, Mukunda B

2010-11-01

To investigate the presence of IgG4+ plasma cells in gastric mucosal biopsy samples from patients with atrophic gastritis (AG) and a history of pernicious anaemia (PA) (AG+PA+). Gastric mucosal biopsy specimens from 46 patients with AG+PA+ were investigated. As controls, we evaluated specimens from patients with AG but no history of PA (AG+ PA-) (n=25), normal histology (n=25), mild chronic inactive gastritis (MCIG) (n=25) or Helicobacter pylori gastritis (HP) (n=25). IgG4+ plasma cells were detected by two immunohistochemical methods: (1) using a monoclonal antibody, the average of the three most cellular high-power fields was counted in areas with the highest density of IgG4+ plasma cells; (2) using a dual-chromagen stain for both IgG4 and CD138 (plasma cell marker), the number of IgG4+ cells per 200 CD138+ plasma cells was counted. The latter was used to ensure that the number of IgG4+ cells was not simply related to the degree of inflammation (density of plasma cells). Identical results were obtained with the two staining methods. Increased numbers of IgG4+ plasma cells were present in 37% of patients with AG+PA+, but in none with AG+PA-, MCIG, HP or normal gastric biopsy results (100% specific, p=0.0001). IgG4+ plasma cells may play a role in the pathogenesis of PA and may be a useful marker for its diagnosis.

Human immunoglobulin allotypes

PubMed Central

Lefranc, Marie-Paule

2009-01-01

More than twenty recombinant monoclonal antibodies are approved as therapeutics. Almost all of these are based on the whole IgG isotype format, but vary in the origin of the variable regions between mouse (chimeric), humanized mouse and fully human sequences; all of those with whole IgG format employ human constant region sequences. Currently, the opposing merits of the four IgG subclasses are considered with respect to the in vivo biological activities considered to be appropriate to the disease indication being treated. Human heavy chain genes also exhibit extensive structural polymorphism(s) and, being closely linked, are inherited as a haplotype. Polymorphisms (allotypes) within the IgG isotype were originally discovered and described using serological reagents derived from humans; demonstrating that allotypic variants can be immunogenic and provoke antibody responses as a result of allo-immunization. The serologically defined allotypes differ widely within and between population groups; therefore, a mAb of a given allotype will, inevitably, be delivered to a cohort of patients homozygous for the alternative allotype. This publication reviews the serologically defined human IgG allotypes and considers the potential for allotype differences to contribute to or potentiate immunogenicity. PMID:20073133

Structural basis for pH-insensitive inhibition of immunoglobulin G recycling by an anti-neonatal Fc receptor antibody

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kenniston, Jon A.; Taylor, Brandy M.; Conley, Gregory P.

The neonatal Fc receptor FcRn plays a critical role in the trafficking of IgGs across tissue barriers and in retaining high circulating concentrations of both IgG and albumin. Although generally beneficial from an immunological perspective in maintaining IgG populations, FcRn can contribute to the pathogenesis of autoimmune disorders when an abnormal immune response targets normal biological components. We previously described a monoclonal antibody (DX-2507) that binds to FcRn with high affinity at both neutral and acidic pH, prevents the simultaneous binding of IgG, and reduces circulating IgG levels in preclinical animal models. Here, we report a 2.5 Å resolution X-raymore » crystal structure of an FcRn–DX-2507 Fab complex, revealing a nearly complete overlap of the IgG–Fc binding site in FcRn by complementarity-determining regions in DX-2507. This overlap explains how DX-2507 blocks IgG binding to FcRn and thereby shortens IgG half-life by preventing IgGs from recycling back into circulation. Moreover, the complex structure explains how the DX-2507 interaction is pH-insensitive unlike normal Fc interactions and how serum albumin levels are unaffected by DX-2507 binding. These structural studies could inform antibody-based therapeutic approaches for limiting the effects of IgG-mediated autoimmune disease.« less

Protection of the Villus Epithelial Cells of the Small Intestine from Rotavirus Infection Does Not Require Immunoglobulin A

PubMed Central

O'Neal, Christine M.; Harriman, Gregory R.; Conner, Margaret E.

2000-01-01

Immunoglobulin A (IgA) is the primary immune response induced in the intestine by rotavirus infection, but vaccination with virus-like particles induces predominantly IgG, not IgA. To definitively assess the role of IgA in protection from rotavirus infection, IgA knockout mice, which are devoid of serum and secretory IgA, were infected and then rechallenged with murine rotavirus at either 6 weeks or 10 months. Following primary rotavirus infection, IgA knockout mice cleared virus as effectively as IgA normal control mice. Rotavirus-infected IgA knockout mice produced no serum or fecal IgA but did have high levels of antirotavirus serum IgG and IgM and fecal IgG, whereas IgA normal control mice made both serum IgA and IgG and fecal IgA. Both IgA normal and IgA knockout mice were totally protected from rotavirus challenge at 42 days. Ten months following a primary infection, both IgA normal and knockout mice still had high levels of serum and fecal antirotavirus antibody and were totally protected from rotavirus challenge. To determine if compensatory mechanisms other than IgG were responsible for protection from rotavirus infection in IgA knockout mice, mice were depleted of CD4+ T cells or CD8+ T cells. No changes in the level of protection were seen in depleted mice. These data show that fecal or systemic IgA is not essential for protection from rotavirus infection and suggest that in the absence of IgA, IgG may play a significant role in protection from mucosal pathogens. PMID:10756022

Altered antigenicity of human monoclonal antibodies derived from human-mouse heterohybridomas.

PubMed

Kan-Mitchell, J; Andrews, K L; Gallardo, D; Mitchell, M S

1987-04-01

We have generated milligram quantities of human monoclonal antibodies (Hu-MAbs) in the ascites of pristane-primed nude mice injected with human-mouse heterohybridomas. After contaminating mouse immunoglobulins were removed by affinity chromatography, an enzyme immunosorbent assay (EIA) was used to measure the concentrations of human immunoglobulins. Ten different partially purified preparations were tested. The titration curves with all 5 IgG Hu-MAbs were unusual, reaching a plateau at a very low apparent maximum concentration of antibody. In contrast, the EIA yielded more usual titration curves and thus apparently more reliable estimates of the concentrations of 4 IgM and 1 IgA monoclonal antibodies. An analogous EIA for the quantitation of mouse IgG monoclonal antibodies also gave accurate estimates. To understand the nature of the discrepancy with human IgG, 5 Hu-MAbs of the 3 classes (2 IgG, 2 pentameric IgM and 1 IgA) were purified to homogeneity for a more detailed analysis. The inability to quantitate the human IgG monoclonal antibodies by EIA was not due to defective molecules, as shown by SDS polyacrylamide gel electrophoresis. The human IgG monoclonal antibodies were found to consist of intact heavy and light chains, as were the IgM and IgA antibodies. The possibility that the human IgG monoclonal antibodies differed antigenically from polyclonal IgG was explored by comparing the concentrations by EIA with the protein concentrations determined by absorbance at 280 nm. This analysis permitted a comparison of the detectability of antigenic determinants on Hu-MAbs with those on polyclonal Ig with goat antibodies to Ig or Ig subclass. The IgG monoclonal antibodies differed from polyclonal IgG in both their heavy and light chains. Goat antiserum monospecific for the gamma chain in fact underestimated the concentration by as much as one hundred-fold. IgM and IgA monoclonal antibodies were less antigenically distinct from their polyclonal counterparts even though their light chains were also underestimated, because goat monospecific antibodies were more efficient at recognizing their heavy chains. The molecular basis for the observed difference in antigenicity is not yet known. These findings have important implications for the analysis of the binding of IgG Hu-MAbs. A direct binding assay with the label directly conjugated to the Hu-MAb should be used in preference to an indirect assay with a labeled detecting antibody to maximize the sensitivity of the assay. The altered antigenicity of IgG Hu-MAbs may also imply decreased immunogenicity when they are given in vivo as carriers for radionuclides or cytotoxic antitumor materials.

Persistent Seroconversion after Accidental Eye Exposure to Calcifying Nanoparticles

NASA Technical Reports Server (NTRS)

Ciftcioglu, Neva; Aho, Katja M.; McKay, David S.; Kajander, E. Olavi

2007-01-01

Biosafety of nanomaterials has attracted much attention recently. We report here a case where accidental human eye exposure to biogenic nanosized calcium phosphate in the form of calcifying nanoparticles (CNP) raised a strong IgG immune response against proteins carried by CNP. The antibody titer has persisted over ten years at the high level. The IgG was detected by ELISA using CNPs propagated in media containing bovine and human serum as antigen. The exposure incident occurred to a woman scientist (WS) at a research laboratory in Finland at 1993. CNP, also termed "nanobacteria", is a unique self-replicating agent that has not been fully characterized and no data on biohazards were available at that time. Before the accident, her serum samples were negative for both CNP antigen and anti-CNP antibody using specific ELISA tests (Nanobac Oy, Kuopio, Finland). The accident occurred while WS was harvesting CNP cultures. Due to a high pressure in pipetting, CNP pellet splashed into her right eye. Both eyes were immediately washed with water and saline. The following days there was irritation and redness in the right eye. These symptoms disappeared within two weeks without any treatment. Three months after the accident, blood and urine samples of WS were tested for CNP cultures (2), CNP-specific ELISA tests, and blood cell counts. Blood cell counts were normal, CNP antigen and culture tests were negative. A high IgG anti-CNP antibody titer was detected (see Figure). The antibodies of this person have been used thereafter as positive control and standard in ELISA manufacturing (Nano-Sero IgG ELISA, Nanobac Oy, Kuopio, Finland).

Feasibility study of the Fab fragment of a monoclonal antibody against tissue factor as a diagnostic tool.

PubMed

Tsumura, Ryo; Sato, Ryuta; Furuya, Fumiaki; Koga, Yoshikatsu; Yamamoto, Yoshiyuki; Fujiwara, Yuki; Yasunaga, Masahiro; Matsumura, Yasuhiro

2015-12-01

Tissue factor (TF) is expressed strongly in various types of cancer, especially cancers that are often refractory to treatment, such as pancreatic cancer. In this study, we compared the differences in the biophysical and pharmacological properties of whole IgG and the Fab fragment of anti-human TF monoclonal antibody (1849 antibodies), in order to determine their suitability for application in the diagnosis and treatment of cancers. In the biophysical examination, we investigated the characteristics of 1849-whole IgG and 1849-Fab by SPR sensing and confocal fluorescence microscopy analysis using recombinant human TF antigen and TF-overexpressing human pancreatic cancer cell line, BxPC3, respectively. After conjugation with Alexa-Flour-647, in vivo imaging was conducted in mice bearing BxPC3 xenograft tumors. Furthermore, the distribution of the conjugates in tumors and major organs was evaluated by ex vivo study. The in vitro experiments showed that 1849 antibodies had high affinity against TF antigen. In addition, 1849-Fab showed a faster dissociation rate from the antigen than 1849-whole IgG. In mice, 1849-Fab-Alexa-Flour-647 showed rapid renal clearance and faster tumor accumulation, achieving a high contrast signal over nearby normal tissues in the early phase and enhanced tumor penetration after administration. On the other hand, 1849-whole IgG-Alexa-Flour-647 showed slow clearance from the blood and sustained high tumor accumulation. These results suggest that 1849-Fab may be a useful tool for pancreatic cancer diagnosis.

Glycosylation of random IgG distinguishes seropositive and seronegative rheumatoid arthritis.

PubMed

Magorivska, I; Döncző, B; Dumych, T; Karmash, A; Boichuk, M; Hychka, K; Mihalj, M; Szabó, M; Csánky, E; Rech, J; Guttman, A; Vari, S G; Bilyy, R

2018-05-01

The N-glycosylation of human immunoglobulins, especially IgGs, plays a critical role in determining affinity of IgGs towards their effector (pro- and anti-inflammatory) receptors. However, it is still not clear whether altered glycosylation is involved in only antibody-dependent disorders like seropositive rheumatoid arthritis (RA) or also in pathologies with similar clinical manifestations, but no specific autoantibodies like seronegative RA. The clarification of that uncertainty was the aim of the current study. Another study aim was the detection of specific glycan forms responsible for altered exposure of native glycoepitopes. We studied sera from seropositive RA (n = 15) and seronegative RA (n = 12) patients for exposure of glycans in native IgG molecules, followed by determination of specific glycans by capillary electrophoresis with laser-induced fluorescent detection (CE-LIF). Aged-matched groups of normal healthy donors (NHD) and samples of intravenous immunoglobulin IgG preparations (IVIG) served as controls. There was significantly stronger binding of Lens culinaris agglutinin (LCA) and Aleuria aurantia lectin (AAL) lectins towards IgG from seropositive RA compared to seronegative RA or NHD. CE-LIF analysis revealed statistically significant increases in bisecting glycans FA2BG2 (p = .006) and FABG2S1 (p = .005) seropositive RA, accompanied by decrease of bisecting monogalactosylated glycan FA2(6)G1 (p = .074) and non-bisecting monosialylated glycan FA2(3)G1S1 (p = .055). The results suggest that seropositive RA is distinct from seronegative RA in terms of IgG glycan moieties, attributable to specific immunoglobulin molecules present in seropositive disease. These glycans were determined to be bisecting GlcNAc-bearing forms FA2BG2 and FABG2S1, and their appearance increased the availability of LCA and AAL lectin-binding sites in native IgG glycoepitopes.

Influence of aggregate size on the binding and activation of the first component of human complement by soluble IgG aggregates.

PubMed Central

Doekes, G; Vanes, L A; Daha, M R

1982-01-01

The interaction between small aggregates of human IgG and the first component of human complement was studied. Stabilized soluble IgG aggregates of restricted size were prepared by heat aggregation of human IgG, followed by sucrose-density ultracentrifugation. Human C1 was isolated in its precursor form by euglobulin precipitation, followed by gel filtration and immunoadsorption. A C1 preparation was obtained of which more than 90% was still in its unactivated form. Soluble aggregates containing 20, 10 or 5 molecules IgG, and monomeric IgG were tested for their ability to bind and to activate C1. The binding of C1 was determined by C1 consumption, whereas the activation of C1 was measured as the increased ability of the C1 preparation to consume purified human C4 after the incubation with the aggregates. The three aggregates tested and monomeric IgG were all able to bind and to activate C1, but the efficiency of both processes markedly increased with increasing aggregate-size. Furthermore, it was found that all four preparations activated an appreciable amount of C1 at concentrations that did not result in any detectable C1 fixation. These results confirm earlier suggestion that C1 can be activated during a short, transient binding to small aggregates or immune complexes that have a low avidity for C1, after which the activated form, C1, is released into the medium. PMID:7068172

IgG and IgE antibodies to Chironomidae in asthmatic patients.

PubMed Central

Yamashita, N; Ito, K; Nakagawa, T; Haida, M; Okudaira, H; Nakada, S; Miyamoto, T; Shibuya, T; Kamei, K; Sasa, M

1987-01-01

IgG antibodies to Chironomidae and its correlations to radioallergosorbent and skin reactions were examined with the aim of clarifying the relationship between asthma and Chironomidae. The level of specific IgG antibody in asthmatic patients (0.698 +/- 0.034, n = 104) was significantly greater than that in normal subjects (0.367 +/- 0.032, n = 52) (P less than 0.01). The specific IgG level was not correlated to skin reaction, nor to IgE RAST scores. Specific IgG1 and IgG4 levels in asthmatic patients were significantly greater than in control subjects (n = 14) (P less than 0.01). Images Fig. 5 PMID:3652516

Humans with chronic granulomatous disease maintain humoral immunologic memory despite low frequencies of circulating memory B cells

PubMed Central

Santich, Brian H.; Kim, Jin Young; Posada, Jacqueline G.; Ho, Jason; Buckner, Clarisa M.; Wang, Wei; Kardava, Lela; Garofalo, Mary; Marciano, Beatriz E.; Manischewitz, Jody; King, Lisa R.; Khurana, Surender; Chun, Tae-Wook; Golding, Hana; Fauci, Anthony S.; Malech, Harry L.

2012-01-01

CD27+ memory B cells are reduced in the blood of patients with chronic granulomatous disease (CGD) for reasons and consequences that remain unclear. Here we confirm not only decreased CD27+ but also IgG+ B cells in the blood of CGD patients compared with healthy donors (HDs). However, among IgG+ B cells, the ratio of CD27− to CD27+ was significantly higher in CGD patients compared with HDs. Similar to conventional memory B cells, CD27−IgG+ B cells of CGD patients expressed activation markers and had undergone somatic hypermutation, albeit at levels lower than their CD27+ counterparts. Functional analyses revealed slight reductions in frequencies of total IgG but not influenza-specific memory B-cell responses, as measured by Elispot in CGD patients compared with HDs. Serum IgG levels and influenza-specific antibodies were also normal in these CGD patients. Finally, we provide evidence that influenza-specific memory B cells can be present within the CD27−IgG+ B-cell compartment. Together, these findings show that, despite reduced circulating CD27+ memory B cells, CGD patients maintain an intact humoral immunologic memory, with potential contribution from CD27− B cells. PMID:23074274

The neonatal Fc receptor (FcRn) binds independently to both sites of the IgG homodimer with identical affinity.

PubMed

Abdiche, Yasmina Noubia; Yeung, Yik Andy; Chaparro-Riggers, Javier; Barman, Ishita; Strop, Pavel; Chin, Sherman Michael; Pham, Amber; Bolton, Gary; McDonough, Dan; Lindquist, Kevin; Pons, Jaume; Rajpal, Arvind

2015-01-01

The neonatal Fc receptor (FcRn) is expressed by cells of epithelial, endothelial and myeloid lineages and performs multiple roles in adaptive immunity. Characterizing the FcRn/IgG interaction is fundamental to designing therapeutic antibodies because IgGs with moderately increased binding affinities for FcRn exhibit superior serum half-lives and efficacy. It has been hypothesized that 2 FcRn molecules bind an IgG homodimer with disparate affinities, yet their affinity constants are inconsistent across the literature. Using surface plasmon resonance biosensor assays that eliminated confounding experimental artifacts, we present data supporting an alternate hypothesis: 2 FcRn molecules saturate an IgG homodimer with identical affinities at independent sites, consistent with the symmetrical arrangement of the FcRn/Fc complex observed in the crystal structure published by Burmeister et al. in 1994. We find that human FcRn binds human IgG1 with an equilibrium dissociation constant (KD) of 760 ± 60 nM (N = 14) at 25°C and pH 5.8, and shows less than 25% variation across the other human subtypes. Human IgG1 binds cynomolgus monkey FcRn with a 2-fold higher affinity than human FcRn, and binds both mouse and rat FcRn with a 10-fold higher affinity than human FcRn. FcRn/IgG interactions from multiple species show less than a 2-fold weaker affinity at 37°C than at 25°C and appear independent of an IgG's variable region. Our in vivo data in mouse and rat models demonstrate that both affinity and avidity influence an IgG's serum half-life, which should be considered when choosing animals, especially transgenic systems, as surrogates.

Double electrochemical covalent coupling method based on click chemistry and diazonium chemistry for the fabrication of sensitive amperometric immunosensor.

PubMed

Qi, Honglan; Li, Min; Zhang, Rui; Dong, Manman; Ling, Chen

2013-08-20

A double electrochemical covalent coupling method based on click chemistry and diazonium chemistry for the fabrication of sensitive amperometric immunosensor was developed. As a proof-of-concept, a designed alkyne functionalized human IgG was used as a capture antibody and a HRP-labeled rabbit anti-goat IgG was used as signal antibody for the determination of the anti-human IgG using the sandwich model. The immunosensor was fabricated by electrochemically grafting a phenylazide on the surface of a glassy carbon electrode, and then, by coupling the alkyne functionalized human IgG with the phenylazide group through an electro-click chemistry in the presence of Cu(II). The amperometric measurement for the determination of the anti-human IgG was performed after the fabricated immunosensor was incubated with the target anti-human IgG and then with the HRP-labeled anti-goat IgG at -0.25V in 0.10M PBS (pH 7.0) containing 0.1mM hydroquinone and 2.0mM H2O2. The results showed that the increased current was linear with the logarithm of the concentration of the anti-human IgG in the range from 1.0×10(-10)g mL(-1) to 1.0×10(-8)g mL(-1) with a detection limit of 3×10(-11)g mL(-1). Furthermore, the feasibility of the double electrochemical covalent coupling method proposed in this work for fabricating the amperometric immunosensor array was explored. This work demonstrates that the double electrochemical covalent coupling method is a promising approach for the fabrication of the immunosensor and immunosensor array. Copyright © 2013 Elsevier B.V. All rights reserved.

Failure of colostral immunoglobulin transfer as an explanation for most infections and deaths of neonatal foals.

PubMed

McGuire, T C; Crawford, T B; Hallowell, A L; Macomber, L E

1977-06-01

Failure in colostral immunoglobulin G (IgG) transfer was found in 9 of 87 Thoroughbred foals. Seven (78%) of these 9 foals acquired infections requiring therapy. Twelve of the foals had partial failure in colostral IgG transfer, and 3 of these had infections requiring therapy. The remaining 66 foals had normal transfer of colostral IgG, and only 2 had detectable infections. The failure of colostral IgG transfer was attributable to nursing problems in only one case. When presuckle postpartum colostrum was collected, 2 of 4 failures of colostral IgG transfer and 4 of 6 partial failures of colostral IgG transfer were explained by low colostral IgG content. Of 11 foals from various other sources and dying of infection before 2 weeks of age, 6 had failure of colostral IgG transfer (less than 200 mg IgG/100 ml serum), and 4 had partial failure (200-400 mg IgG/100 ml serum).

T-cell-independent and T-cell-dependent antibody responses in patients with chronic renal failure.

PubMed

Beaman, M; Michael, J; MacLennan, I C; Adu, D

1989-01-01

Antibody responses against pneumococcal capsular antigens and tetanus toxoid were measured in 14 patients with chronic renal failure who were managed by continuous ambulatory peritoneal dialysis (CAPD) or haemodialysis (HD) and in eight healthy controls. IgG antipneumococcal responses were predominantly of the IgG2 and to a lesser extent IgG1 subclasses, while the IgG response against tetanus toxoid was largely IgG1 with smaller amounts of IgG4 and IgG3. The post-immunisation serum levels of IgG1 and IgM antibody against both antigens were significantly reduced in the uraemic patients compared with controls (P less than 0.05). All the uraemic patients had normal levels of IgG, IgA and IgM in the serum, but elevated levels of IgG3 prior to immunisation. The mechanisms responsible for the asymmetric depression of antibody responses in uraemia are unclear and may account in part for the increased susceptibility to infection in these patients.

The chemiluminescent response of human monocytes to red cells sensitized with monoclonal anti-Rh(D) antibodies.

PubMed

Hadley, A G; Kumpel, B M; Merry, A H

1988-01-01

Luminol-enhanced chemiluminescence (CL) was used to assess the metabolic response of human monocytes to red cells sensitized with known amounts of anti-Rh(D). Monoclonal antibodies were used to facilitate a comparison between the functional activities of IgG1 and IgG3 subclasses. The detection of CL provided a simple, rapid and semi-quantitative means of measuring monocyte response to sensitized red cells (IgG-RBC). Monocyte response to IgG3-RBC was quantitatively greater, more rapid and less susceptible to inhibition by fluid phase IgG than monocyte response to IgG1-RBC. The minimum levels of sensitization required to elicit CL from monocytes were approximately 2500 IgG3 molecules per red cell, or approximately 5000 IgG1 molecules per cell.

Immunoneutralization of Agmatine Sensitizes Mice to μ-Opioid Receptor Tolerance

PubMed Central

Wade, Carrie L.; Eskridge, Lori L.; Nguyen, H. Oanh X.; Kitto, Kelley F.; Stone, Laura S.; Wilcox, George

2009-01-01

Systemically or centrally administered agmatine (decarboxylated arginine) prevents, moderates, or reverses opioid-induced tolerance and self-administration, inflammatory and neuropathic pain, and sequelae associated with ischemia and spinal cord injury in rodents. These behavioral models invoke the N-methyl-d-aspartate (NMDA) receptor/nitric-oxide synthase cascade. Agmatine (AG) antagonizes the NMDA receptor and inhibits nitric-oxide synthase in vitro and in vivo, which may explain its effect in models of neural plasticity. Agmatine has been detected biochemically and immunohistochemically in the central nervous system. Consequently, it is conceivable that agmatine operates in an anti-glutamatergic manner in vivo; the role of endogenous agmatine in the central nervous system remains minimally defined. The current study used an immunoneutralization strategy to evaluate the effect of sequestration of endogenous agmatine in acute opioid analgesic tolerance in mice. First, intrathecal pretreatment with an anti-AG IgG (but not normal IgG) reversed an established pharmacological effect of intrathecal agmatine: antagonism of NMDA-evoked behavior. This result justified the use of anti-AG IgG to sequester endogenous agmatine in vivo. Second, intrathecal pretreatment with the anti-AG IgG sensitized mice to induction of acute spinal tolerance of two μ-opioid receptor-selective agonists, [d-Ala2,N-Me-Phe4,Gly5-ol]-enkephalin and endomorphin-2. A lower dose of either agonist that, under normal conditions, produces moderate or no tolerance was tolerance-inducing after intrathecal pretreatment of anti-AG IgG (but not normal IgG). The effect of the anti-AG IgG lasted for at least 24 h in both NMDA-evoked behavior and the acute opioid tolerance. These results suggest that endogenous spinal agmatine may moderate glutamate-dependent neuroplasticity. PMID:19684255

Immunoneutralization of agmatine sensitizes mice to micro-opioid receptor tolerance.

PubMed

Wade, Carrie L; Eskridge, Lori L; Nguyen, H Oanh X; Kitto, Kelley F; Stone, Laura S; Wilcox, George; Fairbanks, Carolyn A

2009-11-01

Systemically or centrally administered agmatine (decarboxylated arginine) prevents, moderates, or reverses opioid-induced tolerance and self-administration, inflammatory and neuropathic pain, and sequelae associated with ischemia and spinal cord injury in rodents. These behavioral models invoke the N-methyl-D-aspartate (NMDA) receptor/nitric-oxide synthase cascade. Agmatine (AG) antagonizes the NMDA receptor and inhibits nitric-oxide synthase in vitro and in vivo, which may explain its effect in models of neural plasticity. Agmatine has been detected biochemically and immunohistochemically in the central nervous system. Consequently, it is conceivable that agmatine operates in an anti-glutamatergic manner in vivo; the role of endogenous agmatine in the central nervous system remains minimally defined. The current study used an immunoneutralization strategy to evaluate the effect of sequestration of endogenous agmatine in acute opioid analgesic tolerance in mice. First, intrathecal pretreatment with an anti-AG IgG (but not normal IgG) reversed an established pharmacological effect of intrathecal agmatine: antagonism of NMDA-evoked behavior. This result justified the use of anti-AG IgG to sequester endogenous agmatine in vivo. Second, intrathecal pretreatment with the anti-AG IgG sensitized mice to induction of acute spinal tolerance of two micro-opioid receptor-selective agonists, [D-Ala(2),N-Me-Phe(4),Gly(5)-ol]-enkephalin and endomorphin-2. A lower dose of either agonist that, under normal conditions, produces moderate or no tolerance was tolerance-inducing after intrathecal pretreatment of anti-AG IgG (but not normal IgG). The effect of the anti-AG IgG lasted for at least 24 h in both NMDA-evoked behavior and the acute opioid tolerance. These results suggest that endogenous spinal agmatine may moderate glutamate-dependent neuroplasticity.

[Correlation between IgG subtypes and hematological diseases].

PubMed

Shao, Yuan-Yuan; Shao, Zong-Hong

2015-02-01

IgG is the main immunoglobulin, brings the immunolgic effects in body. The human IgG can be divided into four kinds; IgG1, IgG2, IgG3, IgG4, respectively. The structures of IgG1, IgG2, IgG3, IgG4 are different, therefore, their functions are also different. The defects, increase or imbalance of the IgG subtypes in autoimmune diseases, infectious diseases, cancer and other diseases are indicators of the immune response. IgG1, IgG2, IgG3 and IgG4 also play a different important roles in the disease progress. The analysis of IgG subtypes is beneficial to study the etiology, pathogenesis and prognosis of above menthioned deseases. This review briefly summarizes the characteristics of IgG subtypes in thrombotic thrombocytopenic purpura, autoimmune hemolytic anemia, hemophilia, lymphoma and leukemia.

Quantitative measurement of human thyroglobulin-specific antibodies by use of a sensitive enzyme-linked immunoassay.

PubMed

Kuppers, R C; Outschoorn, I M; Hamilton, R G; Burek, C L; Rose, N R

1993-04-01

A quantitative enzyme-linked immunoassay that measures in absolute terms the subclass concentration of human thyroglobulin (huTg)-specific IgG autoantibody was developed. Unique to this study was the use of an affinity-purified anti-huTg standard with a known concentration of the four IgG subclasses. The sensitivity of the ELISA assay was 1-5 ng/ml depending on the IgG subclass being measured. We examined 22 sera of patients with autoimmune thyroid disease. The total huTg-specific antibody concentrations in serum ranged from 0 to nearly 3000 micrograms/ml of IgG. The IgG subclass distribution in individuals with low huTg-specific IgG (< 10 micrograms/ml) was primarily IgG1 and IgG3 Ab. Patients with intermediate levels of huTg IgG (10-600 micrograms/ml) expressed all four subclasses; however, no particular subclass was dominant. Individuals with > 1000 micrograms/ml also showed huTg-Ab in all four subclasses, however, IgG1 and IgG2 were dominant. All four IgG subclasses were used in the response to huTg, although the pattern of usage varied between individuals. There was no dominant subclass usage seen in this patient population.

Detection of glycosylation abnormality in rheumatoid IgG using N-acetylglucosamine-specific Psathyrella velutina lectin.

PubMed

Tsuchiya, N; Endo, T; Matsuta, K; Yoshinoya, S; Takeuchi, F; Nagano, Y; Shiota, M; Furukawa, K; Kochibe, N; Ito, K

1993-07-15

Although the galactose deficiency in the Asn297-linked sugar chains of serum IgG from patients with rheumatoid arthritis (RA) has been established, structural analysis of sugar chains has not been readily available. Psathyrella velutina lectin (PVL) preferentially interacts with the N-acetylglucosamine beta 1-->2Man group, exposed at the termini of sugar chains in agalacto IgG. Biotinylated PVL reacted strongly in Western blotting with H chains of IgG derived from patients with RA. An ELISA-based assay for the detection of agalacto IgG was developed using recombinant protein G and biotinylated PVL in combination, and the screening of patients' sera was performed. PVL binding of serum IgG significantly correlated with percentage of galactose-deficient IgG determined by the structural analysis. Age-related slight increase in PVL binding was observed among normal controls. Patients with RA showed significantly higher PVL binding (37.90 +/- 42.25 U/ml, n = 93) as compared with normal controls (5.75 +/- 2.92 U/ml, n = 112) (p = 0.0001). Patients with SLE showed lower but still significant PVL binding (17.86 +/- 5.18 U/ml, n = 10, p = 0.0001). PVL binding correlated with C-reactive protein level in serial analysis of individual RA patients, and was significantly higher in the synovial fluid compared with paired serum samples. PVL binding assay may provide an ideal tool for the simple and sensitive detection of agalacto IgG.

Role of immunoglobulin G subclasses in Q fever.

PubMed

Camacho, M T; Outschoorn, I; Tellez, A

1995-12-01

The progression of Q fever to either acute or chronic disease has been attributed both to biological characteristics of the bacteria and to the host immune response. In order to determine whether a specific immunoglobulin G (IgG) subclass distribution could play a diagnostic or prognostic role in Q fever, IgG subclass levels were measured in patients with acute or chronic disease. It was observed that (i) IgG1 and IgG3 levels were elevated in patients with chronic Q fever compared to patients with acute disease or normal controls; (ii) variations over time reflected inverse complementary relationships of subclass levels, such as between IgG1 and IgG3 compared with IgG2 and IgG4, or an inverse relationship between IgG1 and IgG2; (iii) variations in IgG2 and IgG3 total subclass levels during follow-up of patients with chronic Q fever showed a decrease in IgG2 with a concomitant increase in IgG3 two years from disease onset. These findings indicate that measurements of IgG subclasses may be a simple, additional tool useful in the diagnosis of Q fever. This data raises the question of an unusual immunoregulatory mechanism in Q fever that is implicated in the presentation of the clinical disease.

Expression of immunoglobulin G in human podocytes, and its role in cell viability and adhesion.

PubMed

Jing, Ziyang; Deng, Hui; Ma, Junfan; Guo, Yanhong; Liang, Yaoxian; Wu, Rui; A, Lata; Geng, Zihan; Qiu, Xiaoyan; Wang, Yue

2018-06-01

Podocyte injury occurs during the initiation and development of numerous forms of glomerular disease, and antibodies targeting podocytes have become a biomarker for diagnosis and monitoring treatment response. Accumulating evidence has suggested that immunoglobulin (Ig) is expressed in non‑B lineage cells, including epithelial cancer cells, myeloid cells and several types of normal cells. The main aim of the present study was to ascertain the expression of IgG in human podocytes and to determine its potential role in cellular bioactivity. The present study detected positive staining for IgG heavy chain (Igγ) and its subtype γ4, and the light chains κ and λ in the cytoplasm or on the membrane by immunofluorescence. In addition, positive bands were detected for Igγ, γ1, γ3, γ4, κ and λ in the lysates of a podocyte cell line by western blotting. Mass spectrometry confirmed IgG1 as an intact tetramer in the culture supernatant. Constant region transcripts of Igγ, γ1, γ3, γ4, κ and λ were identified by reverse transcription‑polymerase chain reaction, and DNA sequencing of these transcripts revealed 96‑99% similarity with Ig mRNAs in the National Center for Biotechnology Information database. Compared with the diverse gene rearrangements from B cell-derived Ig, podocyte‑derived Ig exhibited conservative V(D)J patterns in the variable regions of Igγ and κ chains. Furthermore, the present study investigated the mechanism underlying IgG production in these cells by examining the expression of recombination activating gene (RAG)1, RAG2 and activation‑induced cytidine deaminase. The expression levels of these proteins suggested that podocyte‑derived Ig and traditional Ig may be generated in a similar manner. Furthermore, small interfering RNA‑mediated downregulation of IgG expression reduced podocyte viability and adhesive capabilities. These findings suggested that IgG is expressed in podocytes and that this expression may be associated with podocyte function. Due to its potential biological and clinical significance, this phenomenon warrants further investigation.

Rabbit collagenase. Immunological identity of the enzymes released from cells and tissues in normal and pathological conditions.

PubMed Central

Werb, Z; Reynolds, J J

1975-01-01

1. The immunological cross-reactivity between rabbit collagenases from a variety of normal and pathological sources was examined. The specific antibody raised against collagenase secreted from normal rabbit synovial fibroblasts gave reactions of complete identity with collagenases secreted from fibroblasts derived from rabbit skin, and from synovium from experimentally arthritic rabbits. 2. The rabbit fibroblast collagenase was immunologically identical with collagenases obtained from the organ culture medium of normal rabbit skin, synovium, ear fibrocartilage and subchondral bone. 3. Collagenases from the culture media of normal rabbit synovium and from hyperplastic synovium of rabbits made experimentally arthritic were identical. 4. The collagenase secreted from rabbit fibroblasts gave a reaction completely identical with that of a collagenase extracted directly from a rabbit carcinoma. 5. IgG (immunoglobulin G) from a specific antiserum to rabbit fibroblast collagenase was a potent inhibitor of the collagenases obtained from the culture media of the various rabbit cells and tissues. 6. Collagenases from human synovium and from mouse macrophages and bone were neither precipitated nor inhibited by antibodies to rabbit collagenase. 7. No immunoreactive material was found in lysates of rabbit polymorphonuclear leucocyte granules with the specific antisera to rabbit fibroblast collagenase. No evidence for inactive forms of rabbit collagenase in lysates of the rabbit synovial fibroblasts could be found, either by double immunodiffusion against the specific collagenase, or by displacement of active enzyme from inhibition by the IgG. Images PLATE 1 PMID:56176

Magnetic bead-sensing-platform-based chemiluminescence resonance energy transfer and its immunoassay application.

PubMed

Qin, Guoxin; Zhao, Shulin; Huang, Yong; Jiang, Jing; Ye, Fanggui

2012-03-20

A competitive immunoassay based on chemiluminescence resonance energy transfer (CRET) on the magnetic beads (MBs) is developed for the detection of human immunoglobulin G (IgG). In this protocol, carboxyl-modified MBs were conjugated with horseradish peroxidase (HRP)-labeled goat antihuman IgG (HRP-anti-IgG) and incubated with a limited amount of fluorescein isothiocyanate (FITC)-labeled human IgG to immobilize the antibody-antigen immune complex on the surface of the MBs, which was further incubated with the target analyte (human IgG) for competitive immunoreaction and separated magnetically to remove the supernatant. The chemiluminescence (CL) buffer (containing luminol and H(2)O(2)) was then added, and the CRET from donor luminol to acceptor FITC in the immunocomplex on the surface of MBs occured immediately. The present protocol was evaluated for the competitive immunoassay of human IgG, and a linear relationship between CL intensity ratio (R = I(425)/I(525)) and human IgG concentration in the range of 0.2-4.0 nM was obtained with a correlation coefficient of 0.9965. The regression equation was expressed as R = 1.9871C + 2.4616, and a detection limit of 2.9 × 10(-11) M was obtained. The present method was successfully applied for the detection of IgG in human serum. The results indicate that the present protocol is quite promising for the application of CRET in immunoassays. It could also be developed for detection of other antigen-antibody immune complexes by using the corresponding antigens and respective antibodies.

Comparison of Biological Activity of Human Anti-Apical Membrane Antigen-1 Antibodies Induced by Natural Infection and Vaccination

PubMed Central

Miura, Kazutoyo; Zhou, Hong; Moretz, Samuel E.; Diouf, Ababacar; Thera, Mahamadou A; Dolo, Amagana; Doumbo, Ogobara; Malkin, Elissa; Diemert, David; Miller, Louis H.; Mullen, Gregory E.D.; Long, Carole A.

2009-01-01

Vaccines represent a significant potential means of decreasing global morbidity and mortality due to malaria. Clinical trials in the U.S. with Plasmodium falciparum Apical Membrane Antigen 1 (AMA1) showed that the vaccine induced biologically active antibodies judged by an in vitro parasite Growth Inhibition Assay (GIA). However, the same vaccine in Malian adults did not increase biological activity although it elevated ELISA titers. As GIA has been used to evaluate the biological activity of antibodies induced by blood-stage malarial vaccine candidates, we explored this discrepancy in this study. We affinity purified AMA1-specific antibodies from both US vaccinees and from non-vaccinated individuals living in a malaria-endemic area of Mali, and performed ELISA and GIA. Both AMA1-specifc antibodies induced by vaccination (US) and by natural infection (Mali) have comparable biological activity in GIA when the ELISA titer is normalized. However, a fraction of Malians’ IgG which did not bind to AMA1 protein (Mali-non-AMA1 IgG) reduced the biological activity of the AMA1 antibodies from US vaccinees; in contrast, US-non-AMA1 IgGs did not show a reduction of the biological activity. Further investigation revealed that the reduction was due to malaria-specific IgGs in the Mali-non-AMA1 IgGs. The fact that both US- and Mali-AMA1-specific antibodies showed comparable biological activity supports further development of AMA1-based vaccines. However, the reduction of biological activity of AMA1-specific antibody by other malaria-specific IgGs likely explains the limited effect on growth-inhibitory activity of antibodies induced by AMA1 vaccination in Malian adults and may complicate efforts to develop a blood-stage malaria vaccine. PMID:19050299

Generating and Purifying Fab Fragments from Human and Mouse IgG Using the Bacterial Enzymes IdeS, SpeB and Kgp.

PubMed

Sjögren, Jonathan; Andersson, Linda; Mejàre, Malin; Olsson, Fredrik

2017-01-01

Fab fragments are valuable research tools in various areas of science including applications in imaging, binding studies, removal of Fc-mediated effector functions, mass spectrometry, infection biology, and many others. The enzymatic tools for the generation of Fab fragments have been discovered through basic research within the field of molecular bacterial pathogenesis. Today, these enzymes are widely applied as research tools and in this chapter, we describe methodologies based on bacterial enzymes to generate Fab fragments from both human and mouse IgG. For all human IgG subclasses, the IdeS enzyme from Streptococcus pyogenes has been applied to generate F(ab')2 fragments that subsequently can be reduced under mild conditions to generate a homogenous pool of Fab' fragments. The enzyme Kgp from Porphyromonas gingivalis has been applied to generate intact Fab fragments from human IgG1 and the Fab fragments can be purified using a CH1-specific affinity resin. The SpeB protease, also from S. pyogenes, is able to digest mouse IgGs and has been applied to digest antibodies and Fab fragments can be purified on light chain affinity resins. In this chapter, we describe methodologies that can be used to obtain Fab fragments from human and mouse IgG using bacterial proteases.

An autoanalyzer test for the quantitation of platelet-associated IgG

NASA Technical Reports Server (NTRS)

Levitan, Nathan; Teno, Richard A.; Szymanski, Irma O.

1986-01-01

A new quantitative antiglobulin consumption (QAC) test for the measurement of platelet-associated IgG is described. In this test washed platelets are incubated with anti-IgG at a final dilution of 1:2 million. The unneutralized fraction of anti-IgG remaining in solution is then measured with an Autoanalyzer and soluble IgG is used for calibration. The dose-response curves depicting the percent neutralization of anti-IgG by platelets and by soluble IgG were compared in detail and found to be nearly identical, indicating that platelet-associated IgG can be accurately quantitated by this method. The mean IgG values were 2287 molecules/platelet for normal adults and 38,112 molecules/platelet for ITP patients. The Autoanalyzer QAC test is a sensitive and reproducible assay for the quantitation of platelet-associated IgG.

Modified wick method using Weck-Cel sponges for collection of human rectal secretions and analysis of mucosal HIV antibody.

PubMed

Kozlowski, P A; Lynch, R M; Patterson, R R; Cu-Uvin, S; Flanigan, T P; Neutra, M R

2000-08-01

Weck-Cel sponges were examined for suitability as an absorbent material for nontraumatic collection of rectal secretions in humans. Sponges were tested in vitro and determined by quantitative enzyme-linked immunosorbent assay (ELISA) to be capable of releasing 100% of absorbed albumin and all immunoglobulin subtypes after treatment with detergent-supplemented buffer. Protein composition in rectal secretions collected from normal women with dry sponges (DS) or with sponges previously softened by moistening with saline (MS) was subsequently compared. DS secretions showed evidence of contamination with blood and interstitial fluid-derived albumin, immunoglobulin G (IgG), and monomeric IgA. MS secretions appeared to represent local mucosal secretions more accurately because they contained negligible blood, a greater percentage of secretory IgA within the total IgA, and both lower albumin/IgG ratios and more dramatic alterations in IgG subclass distribution compared with corresponding serum. Anti-HIV IgG, IgM, IgA, and antibodies with secretory component could be demonstrated by ELISA in rectal secretions collected with moist sponges from 8 of 8, 1 of 8, 5 of 8, and 3 of 8 HIV-infected women, respectively. The data show that Weck-Cel sponges, if premoistened, can be used to collect rectal fluids nontraumatically and to obtain quantitative information about concentrations of immunoglobulins and specific antibodies on rectal mucosal surfaces.

Human Lipooligosaccharide IGG That Prevents Endemic Meningococcal Disease Recognizes an Internal Lacto-N-neotetraose Structure*

PubMed Central

Cheng, Hui; Yang, Zhijie; Estabrook, Michele M.; John, Constance M.; Jarvis, Gary A.; McLaughlin, Stephanie; Griffiss, J. McLeod

2011-01-01

Antibodies that initiate complement-mediated killing of Neisseria meningitidis as they enter the bloodstream from the oropharynx protect against disseminated disease. Human IgGs that bind the neisserial L7 lipooligosaccharide (LOS) are bactericidal for L3,7 and L2,4 meningococci in the presence of human complement. These strains share a lacto-N-neotetraose (nLc4) LOS α chain. We used a set of mutants that have successive saccharide deletions from the nLc4 α chain to characterize further the binding and bactericidal activity of nLc4 LOS IgG. We found that the nLc4 α chain conforms at least four different antigens. We separately purified IgG that required the nLc4 (non-reducing) terminal galactose (Gal) for binding and IgG that bound the truncated nLc3 α chain that lacks this Gal residue. IgG that bound the internal nLc3 α chain killed both L3,7 and L2,4 strains, whereas IgG that required the nLc4 terminal Gal residue for binding killed L2,4 stains but not L3,7 strains. These results show that the diversity of LOS antibodies in human serum is as much a function of the conformation of multiple antigens by a single glycoform as of the production of multiple glycoforms. Differences in sensitivity to killing by human nLc4 LOS IgG may account for the fact that fully two-thirds of endemic group B meningococcal disease in infants and children is caused by L3,7 strains, but only 20% is caused by L2,4 stains. PMID:22027827

Differentiation Capacity of Cultured B Lymphocytes from Immunodeficient Patients

PubMed Central

Wu, L. Y. F.; Lawton, A. R.; Cooper, M. D.

1973-01-01

Peripheral blood lymphocytes from 27 healthy individuals and from 18 patients with a diverse spectrum of defects in humoral immunity were examined for their capacity to undergo terminal differentiation in vitro. Pokeweed mitogen induced cells from normal persons to synthesize and secrete IgM. IgG, and IgA as detected by Immunofluorescence and incorporation of [14C]amino acids, Lymphocytes from three boys with X-linked agammaglobulinemia were stimulated to proliferate, but did not synthesize immunoglobulin. Lymphocyte cultures from three of four patients having agammaglobulinemia with B lymphocytes produced different immunoglobulin classes in ratios similar to the in vivo distribution of classes of B lymphocytes, Lymphocytes from a dysgammaglobulinemic boy deficient in serum IgG and IgA, but who had normal numbers of IgM-, IgG-, and IgA-bearing B lymphocytes, could not be stimulated by pokeweed mitogen to make IgG and IgA. Synthesis and secretion of IgA, as well as IgM and IgG, was detected in cell cultures from each of 10 patients with isolated IgA deficiency. The results suggest that deficiencies in immunoglobulin synthesis may reflect either (a) failure to develop B lymphocytes, (b) arrested development of B lymphocytes due to intrinsic metabolic abnormalities, or (c) disturbance of factors extrinsic to the B lymphocyte which are essential for normal induction of plasma cell maturation. Images PMID:4543023

Cutting edge: IL-21 is a switch factor for the production of IgG1 and IgG3 by human B cells.

PubMed

Pène, Jérôme; Gauchat, Jean-François; Lécart, Sandrine; Drouet, Elodie; Guglielmi, Paul; Boulay, Vera; Delwail, Adriana; Foster, Don; Lecron, Jean-Claude; Yssel, Hans

2004-05-01

IL-21 is a cytokine that regulates the activation of T and NK cells and promotes the proliferation of B cells activated via CD40. In this study, we show that rIL-21 strongly induces the production of all IgG isotypes by purified CD19(+) human spleen or peripheral blood B cells stimulated with anti-CD40 mAb. Moreover, it was found to specifically induce the production of IgG(1) and IgG(3) by CD40-activated CD19(+)CD27(-) naive human B cells. Although stimulation of CD19(+) B cells via CD40 alone induced gamma 1 and gamma 3 germline transcripts, as well as the expression of activation-induced cytidine deaminase, only stimulation with both anti-CD40 mAb and rIL-21 resulted in the production of S gamma/S mu switch circular DNA. These results show that IL-21, in addition to promoting growth and differentiation of committed B cells, is a specific switch factor for the production of IgG(1) and IgG(3).

Metal-dependent hydrolysis of myelin basic protein by IgGs from the sera of patients with multiple sclerosis.

PubMed

Polosukhina, Dar'ya I; Kanyshkova, Tat'yana G; Doronin, Boris M; Tyshkevich, Olga B; Buneva, Valentina N; Boiko, Alexey N; Gusev, Evgenii I; Nevinsky, Georgy A; Favorova, Olga O

2006-02-28

Homogeneous IgG fractions were obtained by chromatography of the sera of patients with multiple sclerosis (MS) on Protein G-Sepharose under conditions that remove non-specifically bound proteins. These IgGs contained several chelated metals, the relative amount of which decreases in the order: Fe>or=Ca>Cu>or=Zn>or=Mg>or=Mn>or=Pb>or=Co>or=Ni. In contrast to homogeneous IgGs of healthy individuals, Abs of MS patients effectively hydrolyzed human myelin basic protein (MBP). A minor metal-dependent fraction was obtained by chromatography of highly purified IgGs from MS patient on Chelex-100. This IgG fraction did not hydrolyze human MBP in the absence of Me(2+) ions but was activated after addition of Me(2+) ions: Mg(2+)>Mn(2+)>Cu(2+)>Ca(2+). Proteolytic activities of IgGs from other MS patients were also activated by other metal ions (Ni(2+), Fe(2+), Co(2+), Zn(2+), Pb(2+), and Co(2+)) and especially Ni(2+). Ni(2+)-activated IgGs were separated into distinct MBP-hydrolyzing fractions by chromatography on HiTraptrade mark Chelating Sepharose charged with Ni(2+). Detection of Mg(2+)-dependent proteolytic activity in the SDS-PAGE area corresponding only to IgG provided direct evidence that IgG from sera of MS patients possesses metal-dependent human MBP-hydrolyzing activity. Observed properties of MS abzymes distinguish them from other known mammalian metalloproteases and demonstrate their pronounced catalytic diversity. Metal-dependent IgGs from MS patients represent the first example of abzymes with metal-dependent proteolytic activity.

High resolution mapping of the binding site on human IgG1 for Fc gamma RI, Fc gamma RII, Fc gamma RIII, and FcRn and design of IgG1 variants with improved binding to the Fc gamma R.

PubMed

Shields, R L; Namenuk, A K; Hong, K; Meng, Y G; Rae, J; Briggs, J; Xie, D; Lai, J; Stadlen, A; Li, B; Fox, J A; Presta, L G

2001-03-02

Immunoglobulin G (IgG) Fc receptors play a critical role in linking IgG antibody-mediated immune responses with cellular effector functions. A high resolution map of the binding site on human IgG1 for human Fc gamma RI, Fc gamma RIIA, Fc gamma RIIB, Fc gamma RIIIA, and FcRn receptors has been determined. A common set of IgG1 residues is involved in binding to all Fc gamma R; Fc gamma RII and Fc gamma RIII also utilize residues outside this common set. In addition to residues which, when altered, abrogated binding to one or more of the receptors, several residues were found that improved binding only to specific receptors or simultaneously improved binding to one type of receptor and reduced binding to another type. Select IgG1 variants with improved binding to Fc gamma RIIIA exhibited up to 100% enhancement in antibody-dependent cell cytotoxicity using human effector cells; these variants included changes at residues not found at the binding interface in the IgG/Fc gamma RIIIA co-crystal structure (Sondermann, P., Huber, R., Oosthuizen, V., and Jacob, U. (2000) Nature 406, 267-273). These engineered antibodies may have important implications for improving antibody therapeutic efficacy.

Matrix interference from Fc-Fc interactions in immunoassays for detecting human IgG4 therapeutics.

PubMed

Partridge, Michael A; Karayusuf, Elif Kabuloglu; Dhulipala, Gangadhar; Dreyer, Robert; Daly, Thomas; Sumner, Giane; Pyles, Erica; Torri, Albert

2015-01-01

An assay measuring an IgG4 biotherapeutic in human serum used a drug-specific monoclonal antibody (mAb) capture reagent and an antihuman IgG4 mAb as detection reagent. However, serum IgG4 binding to the capture mAb via Fc-interactions was detected by the anti-IgG4 mAb, causing high background. Two approaches were developed to minimize background; incorporating a mild acid sample preparation step or using the Fab of the capture antibody. Either strategy improved signal:noise dramatically, increasing assay sensitivity >20-fold. Biophysical analyses of antibody domains indicated that noncovalent Fc oligomers could inhibit the background. Matrix interference from human IgG4 binding to the capture mAb was reduced with a Fab fragment of the drug-specific capture antibody or by incorporating a mild acid sample treatment into the assay.

Treatment with human immunoglobulin G improves the early disease course in a mouse model of Duchenne muscular dystrophy.

PubMed

Zschüntzsch, Jana; Zhang, Yaxin; Klinker, Florian; Makosch, Gregor; Klinge, Lars; Malzahn, Dörthe; Brinkmeier, Heinrich; Liebetanz, David; Schmidt, Jens

2016-01-01

Duchenne muscular dystrophy (DMD) is a severe hereditary myopathy. Standard treatment by glucocorticosteroids is limited because of numerous side effects. The aim of this study was to test immunomodulation by human immunoglobulin G (IgG) as treatment in the experimental mouse model (mdx) of DMD. 2 g/kg human IgG compared to human albumin was injected intraperitoneally in mdx mice at the age of 3 and 7 weeks. Advanced voluntary wheel running parameters were recorded continuously. At the age of 11 weeks, animals were killed so that blood, diaphragm, and lower limb muscles could be removed for quantitative PCR, histological analysis and ex vivo muscle contraction tests. IgG compared to albumin significantly improved the voluntary running performance and reduced muscle fatigability in an ex vivo muscle contraction test. Upon IgG treatment, serum creatine kinase values were diminished and mRNA expression levels of relevant inflammatory markers were reduced in the diaphragm and limb muscles. Macrophage infiltration and myopathic damage were significantly ameliorated in the quadriceps muscle. Collectively, this study demonstrates that, in the early disease course of mdx mice, human IgG improves the running performance and diminishes myopathic damage and inflammation in the muscle. Therefore, IgG may be a promising approach for treatment of DMD. Two monthly intraperitoneal injections of human immunoglobulin G (IgG) improved the early 11-week disease phase of mdx mice. Voluntary running was improved and serum levels of creatine kinase were diminished. In the skeletal muscle, myopathic damage was ameliorated and key inflammatory markers such as mRNA expression of SPP1 and infiltration by macrophages were reduced. The study suggests that IgG could be explored as a potential treatment option for Duchenne muscular dystrophy and that pre-clinical long-term studies should be helpful. © 2015 International Society for Neurochemistry.

Analysis of agalacto-IgG in rheumatoid arthritis using surface plasmon resonance.

PubMed

Liljeblad, M; Lundblad, A; Påhlsson, P

2000-05-01

It is well established that IgG from rheumatoid arthritis (RA) patients are less galactosylated than IgG from normal individuals. Determination of agalacto-IgG may therefore aid in diagnosis and treatment of RA. The decrease in galactosylation of IgG leads to an increase in terminal N-acetylglucosamine residues, which can be detected using a specific lectin from Psathyrella velutina. In the present study IgG from RA and control serum was purified using affinity chromatography. The samples were then, after reduction, analyzed on a BIOCORE 2000 system with immobilized Psathyrella velutina lectin. Using this technique it was possible to discriminate between IgG from RA patients and IgG from control individuals with respect to its content of IgG with terminal N-acetylglucosamine. The affinity biosensor technique makes it possible to detect binding without labeling or using secondary antibodies.

Cysteine Racemization on IgG Heavy and Light Chains

PubMed Central

Zhang, Qingchun; Flynn, Gregory C.

2013-01-01

Under basic pH conditions, the heavy chain 220-light chain 214 (H220-L214) disulfide bond, found in the flexible hinge region of an IgG1, can convert to a thioether. Similar conditions also result in racemization of the H220 cysteine. Here, we report that racemization occurs on both H220 and L214 on an IgG1 with a λ light chain (IgG1λ) but almost entirely on H220 of an IgGl with a κ light chain (IgG1κ) under similar conditions. Likewise, racemization was detected at significant levels on H220 and L214 on endogenous human IgG1λ but only at the H220 position on IgG1κ. Low but measurable levels of d-cysteines were found on IgG2 cysteines in the hinge region, both with monoclonal antibodies incubated under basic pH conditions and on antibodies isolated from human serum. A simplified reaction mechanism involving reversible β-elimination on the cysteine is presented that accounts for both base-catalyzed racemization and thioether formation at the hinge disulfide. PMID:24142697

Engraftment of PBMC from SLE and APS Donors into BALB-Rag2−/−IL2Rgc−/− Mice: a Promising Model for Studying Human Disease

PubMed Central

Andrade, Danieli; Redecha, Patricia B.; Vukelic, Milena; Qing, Xiaoping; Perino, Giorgio; Salmon, Jane E.; Koo, Gloria C.

2011-01-01

Purpose To construct a humanized SLE mouse that resembles the human disease to define pathophysiology and targeted for treatments. Methods We infused peripheral blood mononuclear cells (PBMC) from SLE patients into BALB-Rag2−/−IL2Rgc−/−mice (DKO), which lack T, B and NK cells. PBMC from 5 SLE patients and 4 normal donors (ND) at 3–5×106/mouse were infused IV/IP to non-irradiated 4–5 weeks old mice. We evaluated the engraftment of human CD45+cells and monitored the plasma human IgG, anti-dsDNA, anti-cardiolipin (aCL) antibodies, proteinuria, and kidney histology. Results We found 100% successful engraftment of 40 DKO mice infused with human PBMC. In both SLE-DKO and ND-DKO mice, 50–80% human CD45+ cells were observed in PBMC fraction 4–6 weeks post engraftment, with 70–90% CD3+ cells. There were fewer CD3+4+cells (5.5±2.1%) and more CD3+8+cells (79.4±3.6%) in the SLE-DKO mice, as in the SLE patients. CD19+B cells and CD11c+Monocytic cells were found in the spleen, lung, liver and bone marrow. There was no significant difference in plasma human IgG levels and anti-dsDNA antibodies between SLE-DKO and ND-DKO mice. Levels of aCL antibody were significantly higher in all SLE-DKO mice infused with PBMC from a SLE patient with high titers of aCL antibodies. SLE-DKO mice had proteinuria, human IgG deposits in the kidneys and shorter life span. In SLE- DKO mice engrafted from the aCL-positive patient, we found micro-thrombi and infiltration of CD3+, CD8+ and CD19+ cells in the glomeruli, recapitulating APS in these mice. Conclusion A novel humanized SLE-DKO mouse is established, exhibiting many characteristics of immunologic and clinical features of SLE. PMID:21560114

Irreversible inhibition of BTK kinase by a novel highly selective inhibitor CHMFL-BTK-11 suppresses inflammatory response in rheumatoid arthritis model.

PubMed

Wu, Hong; Huang, Qiong; Qi, Ziping; Chen, Yongfei; Wang, Aoli; Chen, Cheng; Liang, Qianmao; Wang, Jinghua; Chen, Wensheng; Dong, Jin; Yu, Kailin; Hu, Chen; Wang, Wenchao; Liu, Xiaochuan; Deng, Yuanxin; Wang, Li; Wang, Beilei; Li, Xiaoxiang; Gray, Nathanael S; Liu, Jing; Wei, Wei; Liu, Qingsong

2017-03-28

BTK plays a critical role in the B cell receptor mediated inflammatory signaling in the rheumatoid arthritis (RA). Through a rational design approach we discovered a highly selective and potent BTK kinase inhibitor (CHMFL-BTK-11) which exerted its inhibitory efficacy through a covalent bond with BTK Cys481. CHMFL-BTK-11 potently blocked the anti-IgM stimulated BCR signaling in the Ramos cell lines and isolated human primary B cells. It significantly inhibited the LPS stimulated TNF-α production in the human PBMC cells but only weakly affecting the normal PBMC cell proliferation. In the adjuvant-induced arthritis rat model, CHMFL-BTK-11 ameliorated the inflammatory response through blockage of proliferation of activated B cells, inhibition of the secretion of the inflammatory factors such as IgG1, IgG2, IgM, IL-6 and PMΦ phagocytosis, stimulation of secretion of IL-10. The high specificity of CHMFL-BTK-11 makes it a useful pharmacological tool to further detect BTK mediated signaling in the pathology of RA.

Extending Serum Half-life of Albumin by Engineering Neonatal Fc Receptor (FcRn) Binding*

PubMed Central

Andersen, Jan Terje; Dalhus, Bjørn; Viuff, Dorthe; Ravn, Birgitte Thue; Gunnarsen, Kristin Støen; Plumridge, Andrew; Bunting, Karen; Antunes, Filipa; Williamson, Rebecca; Athwal, Steven; Allan, Elizabeth; Evans, Leslie; Bjørås, Magnar; Kjærulff, Søren; Sleep, Darrell; Sandlie, Inger; Cameron, Jason

2014-01-01

A major challenge for the therapeutic use of many peptides and proteins is their short circulatory half-life. Albumin has an extended serum half-life of 3 weeks because of its size and FcRn-mediated recycling that prevents intracellular degradation, properties shared with IgG antibodies. Engineering the strictly pH-dependent IgG-FcRn interaction is known to extend IgG half-life. However, this principle has not been extensively explored for albumin. We have engineered human albumin by introducing single point mutations in the C-terminal end that generated a panel of variants with greatly improved affinities for FcRn. One variant (K573P) with 12-fold improved affinity showed extended serum half-life in normal mice, mice transgenic for human FcRn, and cynomolgus monkeys. Importantly, favorable binding to FcRn was maintained when a single-chain fragment variable antibody was genetically fused to either the N- or the C-terminal end. The engineered albumin variants may be attractive for improving the serum half-life of biopharmaceuticals. PMID:24652290

Human IgG repertoire of malaria antigen-immunized human immune system (HIS) mice.

PubMed

Nogueira, Raquel Tayar; Sahi, Vincent; Huang, Jing; Tsuji, Moriya

2017-08-01

Humanized mouse models present an important tool for preclinical evaluation of new vaccines and therapeutics. Here we show the human variable repertoire of antibody sequences cloned from a previously described human immune system (HIS) mouse model that possesses functional human CD4+ T cells and B cells, namely HIS-CD4/B mice. We sequenced variable IgG genes from single memory B-cell and plasma-cell sorted from splenocytes or whole blood lymphocytes of HIS-CD4/B mice that were vaccinated with a human plasmodial antigen, a recombinant Plasmodium falciparum circumsporozoite protein (rPfCSP). We demonstrate that rPfCSP immunization triggers a diverse B-cell IgG repertoire composed of various human VH family genes and distinct V(D)J recombinations that constitute diverse CDR3 sequences similar to humans, although low hypermutated sequences were generated. These results demonstrate the substantial genetic diversity of responding human B cells of HIS-CD4/B mice and their capacity to mount human IgG class-switched antibody response upon vaccination. Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

Alterations in IgG subclasses in acquired immune deficiency syndrome.

PubMed

Outschoorn, I M; Lluberes, R; Natta, C L

1989-01-01

Decreased IgG subclass levels in pyogenic infections and immunocompromised situations have been described. A study was made to determine IgG subclass levels in four groups of 68 Hispanic patients. The first group consisted of 25 terminal patients with AIDS, the second group of 20 i.v. drug abusers, and the third group of eight hospital patients with neither a diagnosis of AIDS/ARC nor a history of i.v. drug abuse. IgG subclass levels of these 53 cases were compared with those of a fourth group of 15 normal controls. The total IgG, IgA, and IgM levels as well as the four IgG subclass concentrations were measured by radial immunodiffusion using appropriate standards and specific antisera. The first two groups had similar values, with an average IgG level of 10.37 g/liter; IgA, 2.68; and IgM, 1.78; subclass levels were IgG1, 6.68 g/liter; IgG2, 2.77; IgG3, 0.34; and IgG4, 0.68. These were significantly lower than those of controls, except for IgG4. Determination of minor subclasses may offer some possibilities for immunomodulation and therapy and could be useful in terms of prognosis.

Correction of X-linked immunodeficient mice by competitive reconstitution with limiting numbers of normal bone marrow cells.

PubMed

Rohrer, J; Conley, M E

1999-11-15

Gene therapy for inherited disorders is more likely to succeed if gene-corrected cells have a proliferative or survival advantage compared with mutant cells. We used a competitive reconstitution model to evaluate the strength of the selective advantage that Btk normal cells have in Btk-deficient xid mice. Whereas 2,500 normal bone marrow cells when mixed with 497,500 xid cells restored serum IgM and IgG3 levels to near normal concentrations in 3 of 5 lethally irradiated mice, 25,000 normal cells mixed with 475,000 xid cells reliably restored serum IgM and IgG3 concentrations and the thymus-independent antibody response in all transplanted mice. Reconstitution was not dependent on lethal irradiation, because sublethally irradiated mice all had elevated serum IgM and IgG3 by 30 weeks postreconstitution when receiving 25,000 normal cells. Furthermore, the xid defect was corrected with as few as 10% of the splenic B cells expressing a normal Btk. When normal donor cells were sorted into B220(+)/CD19(+) committed B cells and B220(-)/CD19(-) cell populations, only the B220(-)/CD19(-) cells provided long-term B-cell reconstitution in sublethally irradiated mice. These findings suggest that even inefficient gene therapy may provide clinical benefit for patients with XLA.

Agglutinating mouse IgG3 compares favourably with IgMs in typing of the blood group B antigen: Functionality and stability studies

PubMed Central

Klaus, Tomasz; Bzowska, Monika; Kulesza, Małgorzata; Kabat, Agnieszka Martyna; Jemioła-Rzemińska, Małgorzata; Czaplicki, Dominik; Makuch, Krzysztof; Jucha, Jarosław; Karabasz, Alicja; Bereta, Joanna

2016-01-01

Mouse immunoglobulins M (IgMs) that recognize human blood group antigens induce haemagglutination and are used worldwide for diagnostic blood typing. Contrary to the current belief that IgGs are too small to simultaneously bind antigens on two different erythrocytes, we obtained agglutinating mouse IgG3 that recognized antigen B of the human ABO blood group system. Mouse IgG3 is an intriguing isotype that has the ability to form Fc-dependent oligomers. However, F(ab′)2 fragments of the IgG3 were sufficient to agglutinate type B red blood cells; therefore, IgG3-triggered agglutination did not require oligomerization. Molecular modelling indicated that mouse IgG3 has a larger range of Fab arms than other mouse IgG subclasses and that the unique properties of mouse IgG3 are likely due to the structure of its hinge region. With a focus on applications in diagnostics, we compared the stability of IgG3 and two IgMs in formulated blood typing reagents using an accelerated storage approach and differential scanning calorimetry. IgG3 was much more stable than IgMs. Interestingly, the rapid decrease in IgM activity was caused by aggregation of the molecules and a previously unknown posttranslational proteolytic processing of the μ heavy chain. Our data point to mouse IgG3 as a potent diagnostic tool. PMID:27484487

Effect of IDA and TREN chelating agents and buffer systems on the purification of human IgG with immobilized nickel affinity membranes.

PubMed

Ribeiro, Mariana Borsoi; Vijayalakshmi, Mookambesvaran; Todorova-Balvay, Daniele; Bueno, Sonia Maria Alves

2008-01-01

The purification of IgG from human plasma was studied by comparing two affinity membranes complexed with Ni(II), prepared by coupling iminodiacetic acid (IDA) and Tris(2-aminoethyl)amine (TREN) to poly(ethylenevinyl alcohol), PEVA, hollow fiber membranes. The Ni(II)-TREN-PEVA hollow fiber membrane had lower capacity for human IgG than the complex Ni(II)-IDA-PEVA, but with similar selectivity. The IgG in peak fractions eluted from the Ni(II)-IDA-PEVA with a stepwise concentration gradient of Tris-HCl pH 7.0 (100-700 mM) reached a purity of 98% (based on IgG, IgM, IgA, albumin, and transferrin nephelometric analysis). Adsorption IgG data at different temperatures (4-37 degrees C) were analyzed using Langmuir model resulting in a calculated maximum capacity at 25 degrees C of 204.6 mg of IgG/g of dry membrane. Decrease in Kd with increasing temperature (1.7x10(-5) to 5.3x10(-6) M) indicated an increase in affinity with increased temperature. The positive value of enthalpy change (26.2 kJ/mol) indicated that the adsorption of IgG in affinity membrane is endothermic. Therefore, lower temperature induces adsorption as verified experimentally.

Transfer of IgG in the female genital tract by MHC class I-related neonatal Fc receptor (FcRn) confers protective immunity to vaginal infection

USDA-ARS?s Scientific Manuscript database

IgG is a major immunoglobulin subclass in mucosal secretions of human female genital tract, where it predominates over the IgA isotype. Despite the abundance of IgG, surprisingly little is known about whether and how IgG enters the lumen of the genital tract and the exact role of local IgG may play ...

Surface modification of microparticles causes differential uptake responses in normal and tumoral human breast epithelial cells

PubMed Central

Patiño, Tania; Soriano, Jorge; Barrios, Lleonard; Ibáñez, Elena; Nogués, Carme

2015-01-01

The use of micro- and nanodevices as multifunctional systems for biomedical applications has experienced an exponential growth during the past decades. Although a large number of studies have focused on the design and fabrication of new micro- and nanosystems capable of developing multiple functions, a deeper understanding of their interaction with cells is required. In the present study, we evaluated the effect of different microparticle surfaces on their interaction with normal and tumoral human breast epithelial cell lines. For this, AlexaFluor488 IgG functionalized polystyrene microparticles (3 μm) were coated with Polyethyleneimine (PEI) at two different molecular weights, 25 and 750 kDa. The effect of microparticle surface properties on cytotoxicity, cellular uptake and endocytic pathways were assessed for both normal and tumoral cell lines. Results showed a differential response between the two cell lines regarding uptake efficiency and mechanisms of endocytosis, highlighting the potential role of microparticle surface tunning for specific cell targeting. PMID:26068810

Surface modification of microparticles causes differential uptake responses in normal and tumoral human breast epithelial cells

NASA Astrophysics Data System (ADS)

Patiño, Tania; Soriano, Jorge; Barrios, Lleonard; Ibáñez, Elena; Nogués, Carme

2015-06-01

The use of micro- and nanodevices as multifunctional systems for biomedical applications has experienced an exponential growth during the past decades. Although a large number of studies have focused on the design and fabrication of new micro- and nanosystems capable of developing multiple functions, a deeper understanding of their interaction with cells is required. In the present study, we evaluated the effect of different microparticle surfaces on their interaction with normal and tumoral human breast epithelial cell lines. For this, AlexaFluor488 IgG functionalized polystyrene microparticles (3 μm) were coated with Polyethyleneimine (PEI) at two different molecular weights, 25 and 750 kDa. The effect of microparticle surface properties on cytotoxicity, cellular uptake and endocytic pathways were assessed for both normal and tumoral cell lines. Results showed a differential response between the two cell lines regarding uptake efficiency and mechanisms of endocytosis, highlighting the potential role of microparticle surface tunning for specific cell targeting.

Surface modification of microparticles causes differential uptake responses in normal and tumoral human breast epithelial cells.

PubMed

Patiño, Tania; Soriano, Jorge; Barrios, Lleonard; Ibáñez, Elena; Nogués, Carme

2015-06-12

The use of micro- and nanodevices as multifunctional systems for biomedical applications has experienced an exponential growth during the past decades. Although a large number of studies have focused on the design and fabrication of new micro- and nanosystems capable of developing multiple functions, a deeper understanding of their interaction with cells is required. In the present study, we evaluated the effect of different microparticle surfaces on their interaction with normal and tumoral human breast epithelial cell lines. For this, AlexaFluor488 IgG functionalized polystyrene microparticles (3 μm) were coated with Polyethyleneimine (PEI) at two different molecular weights, 25 and 750 kDa. The effect of microparticle surface properties on cytotoxicity, cellular uptake and endocytic pathways were assessed for both normal and tumoral cell lines. Results showed a differential response between the two cell lines regarding uptake efficiency and mechanisms of endocytosis, highlighting the potential role of microparticle surface tunning for specific cell targeting.

Salivary IgG subclasses in individuals with and without homozygous IGHG gene deletions.

PubMed Central

Engström, P E; Norhagen, G; Osipova, L; Helal, A; Wiebe, V; Brusco, A; Carbonara, A O; Lefranc, G; Lefranc, M P

1996-01-01

In this study, the levels of salivary IgG1, IgG2, IgG3 and IgG4 from individuals with and without homozygous immunoglobulin heavy chain constant gene deletions were quantified by enzyme-linked immunosorbent assay (ELISA). To analyse the restriction of salivary IgG subclasses, we used unstimulated whole saliva and sera collected at the same time from individuals with homozygous gene deletions, two with G1 deletion, one with G4 deletion, six with both G2 and G4 deletions and from eight individuals without IGHG gene deletions and expressing all four IgG subclasses. The median values of salivary IgG from individuals with homozygous G1, or G4, or both G2 and G4 deletions, and from individuals expressing all four subclasses were 24.2 mg/l and 23.4 mg/l, respectively. The median values of serum IgG were 13.7 g/l and 15.9 g/l, respectively. Our results show that the salivary and serum IgG levels were both within the normal range in individuals with homozygous gene deletions of either G1, or G4, or both G2 and G4. PMID:8943711

Crystallization and preliminary X-ray diffraction studies of an RNA aptamer in complex with the human IgG Fc fragment

PubMed Central

Sugiyama, Shigeru; Nomura, Yusuke; Sakamoto, Taiichi; Kitatani, Tomoya; Kobayashi, Asako; Miyakawa, Shin; Takahashi, Yoshinori; Adachi, Hiroaki; Takano, Kazufumi; Murakami, Satoshi; Inoue, Tsuyoshi; Mori, Yusuke; Nakamura, Yoshikazu; Matsumura, Hiroyoshi

2008-01-01

Aptamers, which are folded DNA or RNA molecules, bind to target molecules with high affinity and specificity. An RNA aptamer specific for the Fc fragment of human immunoglobulin G (IgG) has recently been identified and it has been demonstrated that an optimized 24-nucleotide RNA aptamer binds to the Fc fragment of human IgG and not to other species. In order to clarify the structural basis of the high specificity of the RNA aptamer, it was crystallized in complex with the Fc fragment of human IgG1. Preliminary X-ray diffraction studies revealed that the crystals belonged to the orthorhombic space group P21212, with unit-cell parameters a = 83.7, b = 107.2, c = 79.0 Å. A data set has been collected to 2.2 Å resolution. PMID:18931441

Poly(ADP-ribose) polymerase-1 (Parp-1)-deficient mice demonstrate abnormal antibody responses

PubMed Central

Ambrose, Helen E; Willimott, Shaun; Beswick, Richard W; Dantzer, Françoise; de Murcia, Josiane Ménissier; Yelamos, José; Wagner, Simon D

2009-01-01

Poly(ADP-ribosylation) of acceptor proteins is an epigenetic modification involved in DNA strand break repair, recombination and transcription. Here we provide evidence for the involvement of poly(ADP-ribose) polymerase-1 (Parp-1) in antibody responses. Parp-1−/− mice had increased numbers of T cells and normal numbers of total B cells. Marginal zone B cells were mildly reduced in number, and numbers of follicular B cells were preserved. There were abnormal levels of basal immunoglobulins, with reduced levels of immunoglobulin G2a (IgG2a) and increased levels of IgA and IgG2b. Analysis of specific antibody responses showed that T cell-independent responses were normal but T cell-dependent responses were markedly reduced. Germinal centres were normal in size and number. In vitro purified B cells from Parp-1−/− mice proliferated normally and showed normal IgM secretion, decreased switching to IgG2a but increased IgA secretion. Collectively our results demonstrate that Parp-1 has essential roles in normal T cell-dependent antibody responses and the regulation of isotype expression. We speculate that Parp-1 forms a component of the protein complex involved in resolving the DNA double-strand breaks that occur during class switch recombination. PMID:18778284

Low-affinity FcγR interactions can decide the fate of novel human IgG-sensitised red blood cells and platelets

PubMed Central

Armour, Kathryn L; Smith, Cheryl S; Turner, Craig P; Kirton, Christopher M; Wilkes, Anthony M; Hadley, Andrew G; Ghevaert, Cedric; Williamson, Lorna M; Clark, Michael R

2014-01-01

G1Δnab is a mutant human IgG1 constant region with a lower ability to interact with FcγR than the natural IgG constant regions. Radiolabelled RBCs and platelets sensitised with specific G1Δnab Abs were cleared more slowly from human circulation than IgG1-sensitised counterparts. However, non-destructive splenic retention of G1Δnab-coated RBCs required investigation and plasma radioactivities now suggest this also occurred for platelets sensitised with an IgG1/G1Δnab mixture. In vitro assays with human cells showed that G1Δnab-sensitised RBCs did not cause FcγRI-mediated monocyte activation, FcγRIIIa-mediated antibody-dependent cell-mediated cytotoxicity (ADCC) or macrophage phagocytosis although they did adhere to macrophages. Thus, FcγRII was implicated in the adhesion despite the Δnab mutation reducing the already low-affinity binding to this receptor class. Additional contacts via P-selectin enhance the interaction of sensitised platelets with monocytes and this system provided evidence of FcγRII-dependent activation by G1Δnab. These results emphasise the physiological relevance of low-affinity interactions: It appears that FcγRII interactions of G1Δnab allowed splenic retention of G1Δnab-coated RBCs with inhibitory FcγRIIb binding preventing RBC destruction and that FcγRIIb engagement by G1Δnab on IgG1/G1Δnab-sensitised platelets overcame activation by IgG1. Considering therapeutic blocking Abs, G1Δnab offers lower FcγR binding and a greater bias towards inhibition than IgG2 and IgG4 constant regions. PMID:24285214

The high-affinity receptor for IgG, FcγRI, of humans and non-human primates.

PubMed

Chenoweth, Alicia M; Trist, Halina M; Tan, Peck-Szee; Wines, Bruce D; Hogarth, P Mark

2015-11-01

Non-human primate (NHP) models, especially involving macaques, are considered important models of human immunity and have been essential in preclinical testing for vaccines and therapeutics. Despite this, much less characterization of macaque Fc receptors has occurred compared to humans or mice. Much of the characterization of macaque Fc receptors so far has focused on the low-affinity Fc receptors, particularly FcγRIIIa. From these studies, it is clear that there are distinct differences between the human and macaque low-affinity receptors and their interaction with human IgG. Relatively little work has been performed on the high-affinity IgG receptor, FcγRI, especially in NHPs. This review will focus on what is currently known of how FcγRI interacts with IgG, from mutation studies and recent crystallographic studies of human FcγRI, and how amino acid sequence differences in the macaque FcγRI may affect this interaction. Additionally, this review will look at the functional consequences of differences in the amino acid sequences between humans and macaques. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Fc receptors for mouse IgG1 on human monocytes: polymorphism and role in antibody-induced T cell proliferation.

PubMed

Tax, W J; Hermes, F F; Willems, R W; Capel, P J; Koene, R A

1984-09-01

In previous studies, it was shown that there is polymorphism in the mitogenic effect of mouse IgG1 monoclonal antibodies against the T3 antigen of human T cells. This polymorphism implies that IgG1 anti-T3 antibodies are not mitogenic for T cells from 30% of healthy individuals. The present results demonstrate that this polymorphism is caused by polymorphism of an Fc receptor for mouse IgG1, present on human monocytes. The Fc receptor for murine IgG1 could be detected by a newly developed rosetting assay on monocytes from all individuals responsive to the mitogenic effect of IgG1 anti-T3 antibodies. This Fc receptor was not detectable on monocytes from those individuals exhibiting no mitogenic responses to IgG1 anti-T3 monoclonal antibodies. Cross-linking of T3 antigens appears to be essential for antibody-induced mitosis of T cells, because mononuclear cells that did not proliferate in response to WT 31 (an IgG1 antibody against T3 antigen) showed a proliferative response to Sepharose beads coated with WT 31. The Fc receptor--if functionally present--may be involved in the cross-linking of T3 antigens through anti-T3 antibodies. Further evidence for the involvement of this Fc receptor in antibody-induced T cell proliferation was provided by inhibition studies. Immune complexes containing IgG1 antibodies were able to inhibit the proliferative response to IgG1 anti-T3 antibodies. This inhibition by immune complexes appears to be mediated through the monocyte Fc receptor for mouse IgG1. These findings are important for the interpretation of previously described inhibitory effects of anti-T cell monoclonal antibodies on T cell proliferation, and show that such inhibitory effects may be monocyte-mediated (via immune complexes) rather than caused by a direct involvement of the respective T cell antigens in T cell mitosis. The Fc receptor for mouse IgG1 plays a role in antibody-induced T cell proliferation. Its polymorphism may have important implications for the therapeutic use of IgG1 monoclonal antibodies.

IgG Donor-Specific Anti-Human HLA Antibody Subclasses and Kidney Allograft Antibody-Mediated Injury.

PubMed

Lefaucheur, Carmen; Viglietti, Denis; Bentlejewski, Carol; Duong van Huyen, Jean-Paul; Vernerey, Dewi; Aubert, Olivier; Verine, Jérôme; Jouven, Xavier; Legendre, Christophe; Glotz, Denis; Loupy, Alexandre; Zeevi, Adriana

2016-01-01

Antibodies may have different pathogenicities according to IgG subclass. We investigated the association between IgG subclasses of circulating anti-human HLA antibodies and antibody-mediated kidney allograft injury. Among 635 consecutive kidney transplantations performed between 2008 and 2010, we enrolled 125 patients with donor-specific anti-human HLA antibodies (DSA) detected in the first year post-transplant. We assessed DSA characteristics, including specificity, HLA class specificity, mean fluorescence intensity (MFI), C1q-binding, and IgG subclass, and graft injury phenotype at the time of sera evaluation. Overall, 51 (40.8%) patients had acute antibody-mediated rejection (aABMR), 36 (28.8%) patients had subclinical ABMR (sABMR), and 38 (30.4%) patients were ABMR-free. The MFI of the immunodominant DSA (iDSA, the DSA with the highest MFI level) was 6724±464, and 41.6% of patients had iDSA showing C1q positivity. The distribution of iDSA IgG1-4 subclasses among the population was 75.2%, 44.0%, 28.0%, and 26.4%, respectively. An unsupervised principal component analysis integrating iDSA IgG subclasses revealed aABMR was mainly driven by IgG3 iDSA, whereas sABMR was driven by IgG4 iDSA. IgG3 iDSA was associated with a shorter time to rejection (P<0.001), increased microcirculation injury (P=0.002), and C4d capillary deposition (P<0.001). IgG4 iDSA was associated with later allograft injury with increased allograft glomerulopathy and interstitial fibrosis/tubular atrophy lesions (P<0.001 for all comparisons). Integrating iDSA HLA class specificity, MFI level, C1q-binding status, and IgG subclasses in a Cox survival model revealed IgG3 iDSA and C1q-binding iDSA were strongly and independently associated with allograft failure. These results suggest IgG iDSA subclasses identify distinct phenotypes of kidney allograft antibody-mediated injury. Copyright © 2016 by the American Society of Nephrology.

Combined glyco- and protein-Fc engineering simultaneously enhance cytotoxicity and half-life of a therapeutic antibody.

PubMed

Monnet, Céline; Jorieux, Sylvie; Souyris, Nathalie; Zaki, Ouafa; Jacquet, Alexandra; Fournier, Nathalie; Crozet, Fabien; de Romeuf, Christophe; Bouayadi, Khalil; Urbain, Rémi; Behrens, Christian K; Mondon, Philippe; Fontayne, Alexandre

2014-01-01

While glyco-engineered monoclonal antibodies (mAbs) with improved antibody-dependent cell-mediated cytotoxicity (ADCC) are reaching the market, extensive efforts have also been made to improve their pharmacokinetic properties to generate biologically superior molecules. Most therapeutic mAbs are human or humanized IgG molecules whose half-life is dependent on the neonatal Fc receptor FcRn. FcRn reduces IgG catabolism by binding to the Fc domain of endocytosed IgG in acidic lysosomal compartments, allowing them to be recycled into the blood. Fc-engineered mAbs with increased FcRn affinity resulted in longer in vivo half-life in animal models, but also in healthy humans. These Fc-engineered mAbs were obtained by alanine scanning, directed mutagenesis or in silico approach of the FcRn binding site. In our approach, we applied a random mutagenesis technology (MutaGen™) to generate mutations evenly distributed over the whole Fc sequence of human IgG1. IgG variants with improved FcRn-binding were then isolated from these Fc-libraries using a pH-dependent phage display selection process. Two successive rounds of mutagenesis and selection were performed to identify several mutations that dramatically improve FcRn binding. Notably, many of these mutations were unpredictable by rational design as they were located distantly from the FcRn binding site, validating our random molecular approach. When produced on the EMABling(®) platform allowing effector function increase, our IgG variants retained both higher ADCC and higher FcRn binding. Moreover, these IgG variants exhibited longer half-life in human FcRn transgenic mice. These results clearly demonstrate that glyco-engineering to improve cytotoxicity and protein-engineering to increase half-life can be combined to further optimize therapeutic mAbs.

Application of hanging drop technique to optimize human IgG formulations.

PubMed

Li, Guohua; Kasha, Purna C; Late, Sameer; Banga, Ajay K

2010-01-01

The purpose of this work is to assess the hanging drop technique in screening excipients to develop optimal formulations for human immunoglobulin G (IgG). A microdrop of human IgG and test solution hanging from a cover slide and undergoing vapour diffusion was monitored by a stereomicroscope. Aqueous solutions of IgG in the presence of different pH, salt concentrations and excipients were prepared and characterized. Low concentration of either sodium/potassium phosphate or McIlvaine buffer favoured the solubility of IgG. Addition of sucrose favoured the stability of this antibody while addition of NaCl caused more aggregation. Antimicrobial preservatives were also screened and a complex effect at different buffer conditions was observed. Dynamic light scattering, differential scanning calorimetry and size exclusion chromatography studies were performed to further validate the results. In conclusion, hanging drop is a very easy and effective approach to screen protein formulations in the early stage of formulation development.

Traces of pFc' in IVIG interact with human IgG Fc domains and counteract aggregation.

PubMed

Rispens, Theo; Himly, Martin; Ooievaar-De Heer, Pleuni; den Bleker, Tamara H; Aalberse, Rob C

2010-04-16

To prevent multimer formation, intravenous immunoglobulin (IVIG) is often treated with traces of pepsin. So far, the mechanism behind this treatment has been unclear. Recently, we reported that human IgG4 binds other IgG molecules via Fc-Fc interactions. Here we show that IVIG treated with traces of pepsin (Nanogam) inhibits these interactions. We found that--besides IgG4--peptides corresponding to IgG1 and IgG2 pFc' (products of limited pepsin digestion) are responsible for the inhibitory action. Using radiolabeled pFc', it was found that pFc' binds directly to IgG1. Furthermore, recombinant CH3 fragments were found to also possess binding activity, and potencies of inhibition varied over 3 orders of magnitude amongst the subclasses, IgG4 being most potent. We propose that pFc' formation explains how limited pepsin digestion diminishes adverse effects of IVIG. In particular, the presence of this fragment can enhance the stability of IgG products including IVIG and therapeutical monoclonal antibodies. Indeed, using a model system it was found that acid-induced aggregation of IgG is reduced in the presence of pFc', suggesting a 'chaperone-like' activity of this fragment. Thus, pFc' can modulate Fc interactions and may therefore reduce adverse effects of IVIG, in particular by preventing oligomerization. 2010 Elsevier B.V. All rights reserved.

Novel IgG-Degrading Enzymes of the IgdE Protease Family Link Substrate Specificity to Host Tropism of Streptococcus Species

PubMed Central

Spoerry, Christian; Hessle, Pontus; Lewis, Melanie J.; Paton, Lois; Woof, Jenny M.

2016-01-01

Recently we have discovered an IgG degrading enzyme of the endemic pig pathogen S. suis designated IgdE that is highly specific for porcine IgG. This protease is the founding member of a novel cysteine protease family assigned C113 in the MEROPS peptidase database. Bioinformatical analyses revealed putative members of the IgdE protease family in eight other Streptococcus species. The genes of the putative IgdE family proteases of S. agalactiae, S. porcinus, S. pseudoporcinus and S. equi subsp. zooepidemicus were cloned for production of recombinant protein into expression vectors. Recombinant proteins of all four IgdE family proteases were proteolytically active against IgG of the respective Streptococcus species hosts, but not against IgG from other tested species or other classes of immunoglobulins, thereby linking the substrate specificity to the known host tropism. The novel IgdE family proteases of S. agalactiae, S. pseudoporcinus and S. equi showed IgG subtype specificity, i.e. IgdE from S. agalactiae and S. pseudoporcinus cleaved human IgG1, while IgdE from S. equi was subtype specific for equine IgG7. Porcine IgG subtype specificities of the IgdE family proteases of S. porcinus and S. pseudoporcinus remain to be determined. Cleavage of porcine IgG by IgdE of S. pseudoporcinus is suggested to be an evolutionary remaining activity reflecting ancestry of the human pathogen to the porcine pathogen S. porcinus. The IgG subtype specificity of bacterial proteases indicates the special importance of these IgG subtypes in counteracting infection or colonization and opportunistic streptococci neutralize such antibodies through expression of IgdE family proteases as putative immune evasion factors. We suggest that IgdE family proteases might be valid vaccine targets against streptococci of both human and veterinary medical concerns and could also be of therapeutic as well as biotechnological use. PMID:27749921

Cross-species analysis of Fc engineered anti-Lewis-Y human IgG1 variants in human neonatal receptor transgenic mice reveal importance of S254 and Y436 in binding human neonatal Fc receptor

PubMed Central

Burvenich, Ingrid J. G.; Farrugia, William; Lee, Fook T.; Catimel, Bruno; Liu, Zhanqi; Makris, Dahna; Cao, Diana; O'Keefe, Graeme J.; Brechbiel, Martin W.; King, Dylan; Spirkoska, Violeta; Allan, Laura C.; Ramsland, Paul A.; Scott, Andrew M.

2016-01-01

ABSTRACT IgG has a long half-life through engagement of its Fc region with the neonatal Fc receptor (FcRn). The FcRn binding site on IgG1 has been shown to contain I253 and H310 in the CH2 domain and H435 in the CH3 domain. Altering the half-life of IgG has been pursued with the aim to prolong or reduce the half-life of therapeutic IgGs. More recent studies have shown that IgGs bind differently to mouse and human FcRn. In this study we characterize a set of hu3S193 IgG1 variants with mutations in the FcRn binding site. A double mutation in the binding site is necessary to abrogate binding to murine FcRn, whereas a single mutation in the FcRn binding site is sufficient to no longer detect binding to human FcRn and create hu3S193 IgG1 variants with a half-life similar to previously studied hu3S193 F(ab')2 (t1/2β, I253A, 12.23 h; H310A, 12.94; H435A, 12.57; F(ab')2, 12.6 h). Alanine substitutions in S254 in the CH2 domain and Y436 in the CH3 domain showed reduced binding in vitro to human FcRn and reduced elimination half-lives in huFcRn transgenic mice (t1/2β, S254A, 37.43 h; Y436A, 39.53 h; wild-type, 83.15 h). These variants had minimal effect on half-life in BALB/c nu/nu mice (t1/2β, S254A, 119.9 h; Y436A, 162.1 h; wild-type, 163.1 h). These results provide insight into the interaction of human Fc by human FcRn, and are important for antibody-based therapeutics with optimal pharmacokinetics for payload strategies used in the clinic. PMID:27030023

Gaucher disease: Physical, kinetic and immunologic investigations of human and canine acid. beta. -glucosidase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fabbro, D.E.

1988-01-01

Kinetic and immunologic techniques were developed to investigate the nature of the acid {beta}-glucosidase ({beta}-Glc) defects which results in human and canine Gaucher disease (GD). Two new affinity columns, using the potent inhibitors of {beta}-Glc (N-alkyl-deoxynojirimycins) as affinity ligands, were synthesized and methods were developed to obtain homogeneous {beta}-Glc from normal human placenta. Polyclonal and monoclonal (representing 14 different epitopes from 18 clones) antibodies were produced to the pure normal {beta}-Glc. Monospecific polyclonal IgG and tritiated-bromo-conduritol B epoxide (({sup 3}H)Br-CBE), a specific covalent active site directed inhibitor of {beta}-Glc, were used to quantitate the functional catalytic sites in normal andmore » Type 1 Ashkenazi Jewish GD (AJGD) enzyme preparations: The k{sub cat} values for several new substrates with the mutant enzymes from spleen were about 1.5-fold less than the respective normal enzyme, indicating a nearly normal catalytic capacity of the mutant enzymes. Immunoblotting studies with polyclonal or several monoclonal antibodies indicated three molecular forms of {beta}-Glc (M{sub r} = 67,000, 62,000 to 65,000 and 58,000) in fibroblast extracts from normals and Type 1 AJGD patients. In comparison, only one form of cross-reacting immunologic material (CRIM) was detected in fibroblast extracts from Types 2 and 3 or several non-Jewish Type 1 GD patients.« less

Antibodies to ependymin block the sharpening of the regenerating retinotectal projection in goldfish.

PubMed

Schmidt, J T; Shashoua, V E

1988-04-19

The regenerating optic nerve of goldfish first reestablishes a rough retinotopic map on the tectum, then goes through an activity dependent refinement that appears to involve the elimination of inappropriate branches from early regenerated arbors. Retinotopically appropriate branches and synapses may be stabilized because the normally correlated firing of neighboring ganglion cells could cause summation of their postsynaptic responses, making them more effective. Thus, refinement of the map may be similar in several ways to associative learning. In this study, we therefore tested whether ependymin, a major protein component of the extracellular fluid that has been implicated in synaptic changes thought to be associated with learning a simple task in goldfish, may also be involved in refinement of the retinotopic map. Goldfish that had undergone unilateral optic nerve crush received intraventricular infusion of antiependymin IgG or of control IgG's beginning at 21 days postcrush. Tectal recordings from these fish at 39-56 days postcrush showed that the projection had failed to sharpen, much as in the fish with activity blocked or synchronized; the average size of the multiunit receptive fields was 31 degrees vs 11 degrees normally. The field potentials elicited from these tecta by optic nerve shock were not significantly smaller than in controls, suggesting normal levels of synaptogenesis. Control projections, identically treated but infused with either unrelated IgG or Ringer's alone regenerated normally, giving multiunit receptive fields of 12 degrees. Intact (non-regenerating) projections of the experimental fish were not rendered abnormal by the IgG treatment. Histology showed the retinas and tecta of the infused fish to be normal in appearance. The results show a specific block of sharpening by antiependymin IgG. The ependymal glia of the tectum stain positively for ependymin in normal fish, particularly the cell bodies in the ependymal layer. The tectum, particularly the ependymal layer, stains more intensely during regeneration, which appears to trigger increased synthesis of ependymins in the ependymal glia. This increase and the block of sharpening by specific antibodies to ependymin suggest a possible role for ependymin in activity dependent synaptic stabilization, possibly through its polymerization when calcium is focally depleted at active synapses.

Influence of pH on heat-induced aggregation and degradation of therapeutic monoclonal antibodies.

PubMed

Ishikawa, Tomoyoshi; Ito, Takahiko; Endo, Ryosuke; Nakagawa, Keiko; Sawa, Eiji; Wakamatsu, Kaori

2010-01-01

Monoclonal antibodies are widely used for the treatment of various diseases, and because therapeutic monoclonal antibodies are stored in an aqueous solution or in a lyophilized state, the preparation of a stabilizing formulation that prevents their deterioration (degradation and aggregation) is crucial. Given the structural similarities of the immunoglobulin G (IgG) framework regions and a diversity of only four subclasses, we aimed to find common conditions that stabilize many different antibodies. In this study, we analyzed the effect of pH (the most critical factor in establishing a stable formulation) on human monoclonal antibodies from subclasses IgG1, IgG2, and IgG4, all of which have been utilized in antibody therapeutics. We found that human IgGs are stable with minimal heat-induced degradation and aggregation at pH 5.0-5.5 irrespective of their subclass. We also found that IgG1 is more susceptible to fragmentation, whereas IgG4 is more susceptible to aggregation. This basic information emphasizing the influence of pH on IgG stability should facilitate the optimization of formulation conditions tailored to individual antibodies for specific uses.

Serum levels of immunoglobulins and severity of community-acquired pneumonia

PubMed Central

de la Torre, Mari C; Torán, Pere; Serra-Prat, Mateu; Palomera, Elisabet; Güell, Estel; Vendrell, Ester; Yébenes, Joan Carles; Torres, Antoni; Almirall, Jordi

2016-01-01

Instruction There is evidence of a relationship between severity of infection and inflammatory response of the immune system. The objective is to assess serum levels of immunoglobulins and to establish its relationship with severity of community-acquired pneumonia (CAP) and clinical outcome. Methods This was an observational and cross-sectional study in which 3 groups of patients diagnosed with CAP were compared: patients treated in the outpatient setting (n=54), patients requiring in-patient care (hospital ward) (n=173), and patients requiring admission to the intensive care unit (ICU) (n=191). Results Serum total IgG (and IgG subclasses IgG1, IgG2, IgG3, IgG4), IgA and IgM were measured at the first clinical visit. Normal cutpoints were defined as the lowest value obtained in controls (≤680, ≤323, ≤154, ≤10, ≤5, ≤30 and ≤50 mg/dL for total IgG, IgG1, IgG2, IgG3, IgG4, IgM and IgA, respectively). Serum immunoglobulin levels decreased in relation to severity of CAP. Low serum levels of total IgG, IgG1 and IgG2 showed a relationship with ICU admission. Low serum level of total IgG was independently associated with ICU admission (OR=2.45, 95% CI 1.4 to 4.2, p=0.002), adjusted by the CURB-65 severity score and comorbidities (chronic respiratory and heart diseases). Low levels of total IgG, IgG1 and IgG2 were significantly associated with 30-day mortality. Conclusions Patients with severe CAP admitted to the ICU showed lower levels of immunoglobulins than non-ICU patients and this increased mortality. PMID:27933180

Evaluation of indirect immunofluorescence antibody test and enzyme-linked immunosorbent assay for the diagnosis of infection by Leishmania infantum in clinically normal and sick cats.

PubMed

Chatzis, Manolis K; Leontides, Leonidas; Athanasiou, Labrini V; Papadopoulos, Elias; Kasabalis, Dimitrios; Mylonakis, Mathios; Rallis, Timoleon; Koutinas, Alexandros F; Andreadou, Margarita; Ikonomopoulos, John; Saridomichelakis, Manolis N

2014-12-01

Cats that live in areas where canine and human leishmaniosis due to Leishmania infantum is endemic may become infected and may develop anti-Leishmania antibodies. In this study 50 clinically normal and 50 cats with cutaneous and/or systemic signs that lived in an endemic area and had been previously examined for infection by L. infantum using PCR in four different tissues were serologically tested for the presence of anti-Leishmania IgG (IFAT and ELISA) and IgM (IFAT). The aim was to compare the results of IFAT, ELISA and PCR and to investigate the possible associations between seropositivity to Leishmania spp and signalment, living conditions, season of sampling, health status of the cats, and seropositivity to other infectious agents. Low concentrations of anti-Leishmania IgG were detected by IFAT in 10% of the cats and by ELISA in 1%, whereas anti-Leishmania IgM were detected by IFAT in 1%. There was disagreement between the results of IFAT and ELISA for anti-Leishmania IgG (P = 0.039) and between all serological tests and PCR (P < 0.001). The diagnostic sensitivity of all serological tests, using PCR as the gold standard, was very low, but ELISA and IFAT for anti-Leishmania IgM had 100% specificity. The diagnostic sensitivity of all serological tests could not be improved by changing the cut-off values. Seropositivity for Leishmania spp was not associated with signalment, living conditions, season of sampling and health status of the cats or with seropositivity to feline leukemia virus, feline immunodeficiency virus, feline coronavirus, Toxoplasma gondii and Bartonella henselae. In conclusion, because of their low sensitivity and very high specificity two of the evaluated serological tests (ELISA for anti-Leishmania IgG and IFAT for anti-Leishmania IgM) may be useless as population screening tests but valuable for diagnosing feline infection by L. infantum. Copyright © 2014 Elsevier Inc. All rights reserved.

Micro-bead injection spectroscopy for label-free automated determination of immunoglobulin G in human serum.

PubMed

Ramos, Inês I; Magalhães, Luís M; Barreiros, Luisa; Reis, Salette; Lima, José L F C; Segundo, Marcela A

2018-01-01

Immunoglobulin G (IgG) represents the major fraction of antibodies in healthy adult human serum, and deviations from physiological levels are a generic marker of disease corresponding to different pathologies. Therefore, screening methods for IgG evaluation are a valuable aid to diagnostics. The present work proposes a rapid, automatic, and miniaturized method based on UV-vis micro-bead injection spectroscopy (μ-BIS) for the real-time determination of human serum IgG with label-free detection. Relying on attachment of IgG in rec-protein G immobilized in Sepharose 4B, a bioaffinity column is automatically assembled, where IgG is selectively retained and determined by on-column optical density measurement. A "dilution-and-shoot" approach (50 to 200 times) was implemented without further sample treatment because interferences were flushed out of the column upon sample loading, with minimization of carryover and cross-contamination by automatically discarding the sorbent (0.2 mg) after each determination. No interference from human serum albumin at 60 mg mL -1 in undiluted sample was found. The method allowed IgG determination in the range 100-300 μg mL -1 (corresponding to 5.0-60 mg mL -1 in undiluted samples), with a detection limit of 33 μg mL -1 (1.7 mg mL -1 for samples, dilution factor of 50). RSD values were < 9.4 and < 11.7%, for intra and inter-assay precision, respectively, while recovery values for human serum spiked with IgG at high pathological levels were 97.8-101.4%. Comparison to commercial ELISA kit showed no significant difference for tested samples (n = 8). Moreover, time-to-result decreased from several hours to < 5 min and analysis cost decreased 10 times, showing the potential of the proposed approach as a point-of-care method. Graphical abstract Micro-Bead Injection Spectroscopy method for real time, automated and label-free determination of total serum human Immunoglobulin G (IgG). The method was designed for Lab-on-Valve (LOV) platforms using a miniaturised protein G bioaffinity separative approach. IgG are separated from serum matrix components upon quantification with low non-specific binding in less than 5 min.

Anti-desmoglein 1 antibodies in Tunisian healthy subjects: arguments for the role of environmental factors in the occurrence of Tunisian pemphigus foliaceus

PubMed Central

KALLEL SELLAMI, M; BEN AYED, M; MOUQUET, H; DROUOT, L; ZITOUNI, M; MOKNI, M; CERRUTI, M; TURKI, H; FEZZA, B; MOKHTAR, I; BEN OSMAN, A; ZAHAF, A; KAMOUN, M R; JOLY, P; MASMOUDI, H; MAKNI, S; TRON, F; GILBERT, D

2004-01-01

Pemphigus foliaceus is an autoimmune blistering skin disease mediated by autoantibodies directed against desmoglein 1 and occurs as a sporadic form throughout the world, or as an endemic form called fogo selvagem in Brazil. Healthy subjects living in Brazilian endemic areas produce antidesmoglein 1 antibodies, suggesting the role of environmental factors in the initiation of the autoimmune response. Tunisia was described recently as an endemic area where the disease is characterized by its high rate among young people, especially women. An enzyme-linked immunosorbent assay using recombinant desmoglein 1 as antigen was used to detect antibodies against desmoglein 1 and calibrated with sera from 67 French healthy blood donors, 20 French pemphigus foliaceus patients and patients with other bullous skin diseases. When sera from 179 healthy Tunisian blood donors were tested, 31 (17%) were found positive. The desmoglein 1 binding activity of these 31 sera was confirmed in 10 cases by indirect immunofluorescence analysis and/or immunoblotting using human epidermal extract. Subclass analysis of antidesmoglein 1 antibodies showed that they were almost exclusively of the IgG2 subclass in positive normal sera and of IgG4 subclass in patients with PF. Thus, antibodies against desmoglein 1 are prevalent in normal subjects living in Tunisia which, along with their IgG2 isotype, suggests the role of the environment in the pathogenesis of this endemic type of pemphigus foliaceus and the need for additional factors to switch from a subclinical to a clinical form of the disease. PMID:15196262

Relationship of IgG, C3 and transferrin with opsonising and bacteriostatic activity of peritoneal fluid from CAPD patients and the incidence of peritonitis.

PubMed

McGregor, S J; Brock, J H; Briggs, J D; Junor, B J

1987-01-01

IgG, C3 and transferrin in peritoneal dialysis effluent of patients undergoing continuous ambulatory peritoneal dialysis (CAPD) were 1%-2% of those in serum. In contrast, the values in normal peritoneal fluid were not significantly different from those in serum. The three proteins correlated with each other in peritoneal dialysis effluent, but were independent of the amount in the corresponding patients' sera. There was also an overall inverse correlation between total protein in peritoneal dialysis effluent and time on CAPD during the first 6 months of treatment but not thereafter, which suggests that changes in membrane permeability occur during the early months. In peritoneal dialysis effluent, but not in normal peritoneal fluid, there was a correlation between opsonising capacity and IgG or C3 concentrations. An inverse correlation between opsonic activity of peritoneal dialysis effluent and frequency of peritonitis was also found. Peritoneal dialysis effluent permitted significantly faster multiplication of Staphylococcus epidermidis than sera or normal peritoneal fluid, and the growth rate correlated inversely with the transferrin levels in peritoneal dialysis effluent. Overall IgG, C3 and transferrin in peritoneal dialysis effluent are inadequate for optimal opsonising and bacteriostatic activity, and the peritoneal cavities of CAPD patients are therefore immunocompromised sites.

An aortoduodenal fistula as a complication of immunoglobulin G4-related disease

PubMed Central

Sarac, Momir; Marjanovic, Ivan; Bezmarevic, Mihailo; Zoranovic, Uros; Petrovic, Stanko; Mihajlovic, Miodrag

2012-01-01

Most primary aortoduodenal fistulas occur in the presence of an aortic aneurysm, which can be part of immunoglobulin G4 (IgG4)-related sclerosing disease. We present a case who underwent endovascular grafting of an aortoduodenal fistula associated with a high serum IgG4 level. A 56-year-old male underwent urgent endovascular reconstruction of an aortoduodenal fistula. The patient received antibiotics and other supportive therapy, and the postoperative course was uneventful, however, elevated levels of serum IgG, IgG4 and C-reactive protein were noted, which normalized after the introduction of steroid therapy. Control computed tomography angiography showed no endoleaks. The primary aortoduodenal fistula may have been associated with IgG4-related sclerosing disease as a possible complication of IgG4-related inflammatory aortic aneurysm. Endovascular grafting of a primary aortoduodenal fistula is an effective and minimally invasive alternative to standard surgical repair. PMID:23155348

Passive transfer of affinity-purified anti-heart autoantibodies (AHA) from sera of patients with myocarditis induces experimental myocarditis in mice.

PubMed

Caforio, Alida L P; Angelini, Annalisa; Blank, Miri; Shani, Alice; Kivity, Shaye; Goddard, Gisele; Doria, Andrea; Schiavo, Alessandro; Testolina, Martina; Bottaro, Stefania; Marcolongo, Renzo; Thiene, Gaetano; Iliceto, Sabino; Shoenfeld, Yehuda

2015-01-20

Human autoimmune myocarditis is characterized by an increased frequency of serum organ and disease-specific anti-heart autoantibodies (AHA) in affected patients. To assess whether AHA are directly pathogenic, we used the passive transfer technique of AHA from patients to normal Balb/c mice to induce an experimental myocarditis. In keeping with a classical passive transfer experiment, sera from 5 AHA positive myocarditis patients (3 male, mean age 30 ± 11 years, 3 with giant cell and 2 with lymphocytic myocarditis) were affinity purified and injected into 25 Balb/c mice. As controls, affinity purified sera from 5 healthy donors were passively transferred to 25 Balb/c mice. Further 15 control mice were injected with phosphate-buffered saline and 9 mice did not receive any injection. In all patients cardiac-specific AHA of IgG class had been previously detected by an indirect immunofluorescence (IFL) technique on cryostat sections of O blood group human heart. The animals were sacrificed after 4 weeks and the hearts were blindly examined for histological evidence of myocarditis by an expert cardiac pathologist. Myocarditis was present in 13/25 (52%) of the mice which received affinity-purified IgG from patients. The findings of severe, moderate or mild myocarditis were more common in the mice which received affinity-purified IgG from patients (20%; 20% and 12%) than in control animals (2%, p=0.01; 0%, p=0.003; and 0%, p=0.04 respectively). These findings provide a new evidence for AHA-mediated pathogenicity in human myocarditis, according to Rose-Witebsky criteria. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Reformatting palivizumab and motavizumab from IgG to human IgA impairs their efficacy against RSV infection in vitro and in vivo.

PubMed

Jacobino, Shamir R; Nederend, Maaike; Reijneveld, J Frederiek; Augustijn, Daan; Jansen, J H Marco; Meeldijk, Jan; Reiding, Karli R; Wuhrer, Manfred; Coenjaerts, Frank E J; Hack, C Erik; Bont, Louis J; Leusen, Jeanette H W

2018-04-01

Respiratory syncytial virus (RSV) infection is a leading cause of hospitalization and mortality in young children. Protective therapy options are limited. Currently, palivizumab, a monoclonal IgG1 antibody, is the only licensed drug for RSV prophylaxis, although other IgG antibody candidates are being evaluated. However, at the respiratory mucosa, IgA antibodies are most abundant and act as the first line of defense against invading pathogens. Therefore, it would be logical to explore the potential of recombinant human IgA antibodies to protect against viral respiratory infection, but very little research on the topic has been published. Moreover, it is unknown whether human antibodies of the IgA isotype are better suited than those of the IgG isotype as antiviral drugs to combat respiratory infections. To address this, we generated various human IgA antibody formats of palivizumab and motavizumab, two well-characterized human IgG1 anti-RSV antibodies. We evaluated their efficacy to prevent RSV infection in vitro and in vivo and found similar, but somewhat decreased efficacy for different IgA subclasses and formats. Thus, reformatting palivizumab or motavizumab into IgA reduces the antiviral potency of either antibody. Moreover, our results indicate that the efficacy of intranasal IgA prophylaxis against RSV infection in human FcαRI transgenic mice is independent of Fc receptor expression.

Transduction of beta3 integrin subunit cDNA confers on human keratinocytes the ability to adhere to gelatin.

PubMed

Kubo, Miyoko; Clark, Richard A F; Katz, Anne B; Taichman, Lorne B; Jin, Zaishun; Zhao, Ying; Moriguchi, Takahiko

2007-04-01

alphavbeta3 is a multiligand integrin receptor that interacts with fibrinogen (FG), fibrin (FB), fibronectin (FN), vitronectin (VN), and denatured collagen. We previously reported that cultured normal human keratinocytes, like in vivo keratinocytes, do not express alphavbeta3 on the cell surface, and do not adhere to and migrate on FG and FB. Furthermore, we reported that human keratinocytes transduced with beta3 integrin subunit cDNA by a retrovirus-mediated transduction method express alphavbeta3 on the cell surface and adhere to FG, FB, FN, and VN significantly compared with beta-galactosidase (beta-gal) cDNA-transduced keratinocytes (control). In this study, we determined whether these beta3 integrin subunit cDNA-transduced keratinocytes or normal human keratinocytes adhere to denatured collagen (gelatin) using a 1 h cell adhesion assay. beta3 cDNA-transduced keratinocytes adhered to gelatin, whereas no significant adhesion was observed with the control cells (beta-gal cDNA-transduced keratinocytes and normal human keratinocytes). The adhesion to gelatin was inhibited by LM609, a monoclonal antibody to alphavbeta3, and RGD peptides but not by normal mouse IgG1 nor RGE peptides. Thus, transduction of beta3 integrin subunit cDNA confers on human keratinocytes the ability to adhere to denatured collagen (gelatin) as well as to FG, FB, VN, and FN. Otherwise, normal human keratinocytes do not adhere to gelatin. These data support the idea that beta3 cDNA-transduced human keratinocytes can be a good material for cultured epithelium to achieve better take rate with acute or chronic wounds, in which FG, FB, and denatured collagen are abundantly present.

Affinity partitioning of human antibodies in aqueous two-phase systems.

PubMed

Rosa, P A J; Azevedo, A M; Ferreira, I F; de Vries, J; Korporaal, R; Verhoef, H J; Visser, T J; Aires-Barros, M R

2007-08-24

The partitioning of human immunoglobulin (IgG) in a polymer-polymer and polymer-salt aqueous two-phase system (ATPS) in the presence of several functionalised polyethylene glycols (PEGs) was studied. As a first approach, the partition studies were performed with pure IgG using systems in which the target protein remained in the bottom phase when the non-functionalised systems were tested. The effect of increasing functionalised PEG concentration and the type of ligand were studied. Afterwards, selectivity studies were performed with the most successful ligands first by using systems containing pure proteins and an artificial mixture of proteins and, subsequently, with systems containing a Chinese hamster ovary (CHO) cells supernatant. The PEG/phosphate ATPS was not suitable for the affinity partitioning of IgG. In the PEG/dextran ATPS, the diglutaric acid functionalised PEGs (PEG-COOH) displayed great affinity to IgG, and all IgG could be recovered in the top phase when 20% (w/w) of PEG 150-COOH and 40% (w/w) PEG 3350-COOH were used. The selectivity of these functionalised PEGs was evaluated using an artificial mixture of proteins, and PEG 3350-COOH did not show affinity to IgG in the presence of typical serum proteins such as human serum albumin and myoglobin, while in systems with PEG 150-COOH, IgG could be recovered with a yield of 91%. The best purification of IgG from the CHO cells supernatant was then achieved in a PEG/dextran ATPS in the presence of PEG 150-COOH with a recovery yield of 93%, a purification factor of 1.9 and a selectivity to IgG of 11. When this functionalised PEG was added to the ATPS, a 60-fold increase in selectivity was observed when compared to the non-functionalised systems.

Homogeneous immunoglobulins in sera of Rhesus monkeys after lethal irradiation and bone marrow transplantation

PubMed Central

Rádl, J.; van den Berg, P.; Voormolen, M.; Hendriks, W. D. H.; Schaefer, U. W.

1974-01-01

The immunoglobulin pattern in the sera of lethally irradiated and bone marrow transplanted Rhesus monkeys was studied during the reconstitution of their immune system. All of the irradiated monkeys which survived longer than 30 days, and in which reconstitution of their immune system took place, also developed homogeneous immunoglobulins (HI) in their sera. These homogeneous, sometimes multiple, immunoglobulins were transient. However, they persisted frequently in the sera for several months. In two monkeys which were additionally immunized with a complex antigen (normal human serum), clear-cut M-components appeared in the serum about 10 days later. These HI of IgG class did not precipitate the antigen in immunodiffusion techniques; however, when passing the serum through an immunoadsorbent prepared from normal human serum, only the HI were specifically retained on the column and afterwards isolated by elution. ImagesFIG. 1FIG. 2 PMID:4143277

Marked central nervous system pathology in CD59 knockout rats following passive transfer of Neuromyelitis optica immunoglobulin G.

PubMed

Yao, Xiaoming; Verkman, Alan S

2017-02-17

Neuromyelitis optica spectrum disorders (herein called NMO) is an inflammatory demyelinating disease of the central nervous system in which pathogenesis involves complement-dependent cytotoxicity (CDC) produced by immunoglobulin G autoantibodies targeting aquaporin-4 (AQP4-IgG) on astrocytes. We reported evidence previously, using CD59 -/- mice, that the membrane-associated complement inhibitor CD59 modulates CDC in NMO (Zhang and Verkman, J. Autoimmun. 53:67-77, 2014). Motivated by the observation that rats, unlike mice, have human-like complement activity, here we generated CD59 -/- rats to investigate the role of CD59 in NMO and to create NMO pathology by passive transfer of AQP4-IgG under conditions in which minimal pathology is produced in normal rats. CD59 -/- rats generated by CRISPR/Cas9 technology showed no overt phenotype at baseline except for mild hemolysis. CDC assays in astrocyte cultures and cerebellar slices from CD59 -/- rats showed much greater sensitivity to AQP4-IgG and complement than those from CD59 +/+ rats. Intracerebral administration of AQP4-IgG in CD59 -/- rats produced marked NMO pathology, with astrocytopathy, inflammation, deposition of activated complement, and demyelination, whereas identically treated CD59 +/+ rats showed minimal pathology. A single, intracisternal injection of AQP4-IgG in CD59 -/- rats produced hindlimb paralysis by 3 days, with inflammation and deposition of activated complement in spinal cord, optic nerves and brain periventricular and surface matter, with most marked astrocyte injury in cervical spinal cord. These results implicate an important role of CD59 in modulating NMO pathology in rats and demonstrate amplification of AQP4-IgG-induced NMO disease with CD59 knockout.

Clearance of Human IgG1-Sensitised Red Blood Cells In Vivo in Humans Relates to the In Vitro Properties of Antibodies from Alternative Cell Lines

PubMed Central

Armour, Kathryn L.; Smith, Cheryl S.; Ip, Natasha C. Y.; Ellison, Cara J.; Kirton, Christopher M.; Wilkes, Anthony M.; Williamson, Lorna M.; Clark, Michael R.

2014-01-01

We previously produced a recombinant version of the human anti-RhD antibody Fog-1 in the rat myeloma cell line, YB2/0. When human, autologous RhD-positive red blood cells (RBC) were sensitised with this IgG1 antibody and re-injected, they were cleared much more rapidly from the circulation than had been seen earlier with the original human-mouse heterohybridoma-produced Fog-1. Since the IgG have the same amino acid sequence, this disparity is likely to be due to alternative glycosylation that results from the rat and mouse cell lines. By comparing the in vitro properties of YB2/0-produced Fog-1 IgG1 and the same antibody produced in the mouse myeloma cell line NS0, we now have a unique opportunity to pinpoint the cause of the difference in ability to clear RBC in vivo. Using transfected cell lines that express single human FcγR, we showed that IgG1 made in YB2/0 and NS0 cell lines bound equally well to receptors of the FcγRI and FcγRII classes but that the YB2/0 antibody was superior in FcγRIII binding. When measuring complexed IgG binding, the difference was 45-fold for FcγRIIIa 158F, 20-fold for FcγRIIIa 158V and approximately 40-fold for FcγRIIIb. The dissimilarity was greater at 100-fold in monomeric IgG binding assays with FcγRIIIa. When used to sensitise RBC, the YB2/0 IgG1 generated 100-fold greater human NK cell antibody-dependent cell-mediated cytotoxicity and had a 103-fold advantage over the NS0 antibody in activating NK cells, as detected by CD54 levels. In assays of monocyte activation and macrophage adherence/phagocytosis, where FcγRI plays major roles, RBC sensitised with the two antibodies produced much more similar results. Thus, the alternative glycosylation profiles of the Fog-1 antibodies affect only FcγRIII binding and FcγRIII-mediated functions. Relating this to the in vivo studies confirms the importance of FcγRIII in RBC clearance. PMID:25302805

Clearance of human IgG1-sensitised red blood cells in vivo in humans relates to the in vitro properties of antibodies from alternative cell lines.

PubMed

Armour, Kathryn L; Smith, Cheryl S; Ip, Natasha C Y; Ellison, Cara J; Kirton, Christopher M; Wilkes, Anthony M; Williamson, Lorna M; Clark, Michael R

2014-01-01

We previously produced a recombinant version of the human anti-RhD antibody Fog-1 in the rat myeloma cell line, YB2/0. When human, autologous RhD-positive red blood cells (RBC) were sensitised with this IgG1 antibody and re-injected, they were cleared much more rapidly from the circulation than had been seen earlier with the original human-mouse heterohybridoma-produced Fog-1. Since the IgG have the same amino acid sequence, this disparity is likely to be due to alternative glycosylation that results from the rat and mouse cell lines. By comparing the in vitro properties of YB2/0-produced Fog-1 IgG1 and the same antibody produced in the mouse myeloma cell line NS0, we now have a unique opportunity to pinpoint the cause of the difference in ability to clear RBC in vivo. Using transfected cell lines that express single human FcγR, we showed that IgG1 made in YB2/0 and NS0 cell lines bound equally well to receptors of the FcγRI and FcγRII classes but that the YB2/0 antibody was superior in FcγRIII binding. When measuring complexed IgG binding, the difference was 45-fold for FcγRIIIa 158F, 20-fold for FcγRIIIa 158V and approximately 40-fold for FcγRIIIb. The dissimilarity was greater at 100-fold in monomeric IgG binding assays with FcγRIIIa. When used to sensitise RBC, the YB2/0 IgG1 generated 100-fold greater human NK cell antibody-dependent cell-mediated cytotoxicity and had a 103-fold advantage over the NS0 antibody in activating NK cells, as detected by CD54 levels. In assays of monocyte activation and macrophage adherence/phagocytosis, where FcγRI plays major roles, RBC sensitised with the two antibodies produced much more similar results. Thus, the alternative glycosylation profiles of the Fog-1 antibodies affect only FcγRIII binding and FcγRIII-mediated functions. Relating this to the in vivo studies confirms the importance of FcγRIII in RBC clearance.

IgG4 plasma cell myeloma: new insights into the pathogenesis of IgG4-related disease.

PubMed

Geyer, Julia T; Niesvizky, Ruben; Jayabalan, David S; Mathew, Susan; Subramaniyam, Shivakumar; Geyer, Alexander I; Orazi, Attilio; Ely, Scott A

2014-03-01

IgG4-related disease is a newly described systemic fibroinflammatory process, characterized by increase in IgG4-positive plasma cells. Its pathogenesis, including the role of IgG4, remains poorly understood. Plasma cell myeloma is typically associated with a large monoclonal serum spike, which is frequently of IgG isotype. We sought to identify and characterize a subset of IgG4-secreting myeloma, as it may provide a biological model of disease with high serum levels of IgG4. Six out of 158 bone marrow biopsies (4%) from patients with IgG myeloma expressed IgG4. Four patients were men and two were women, with a mean age of 64 (range 53-87) years. Imaging showed fullness of pancreatic head (1), small non-metabolic lymphadenopathy (1), and bone lytic lesions (6). Two patients developed necrotizing fasciitis. All had elevated serum M-protein (mean 2.4, range 0.5-4.2 g/dl), and none had definite signs or symptoms of IgG4-related disease. Four myelomas had plasmablastic morphology. Four had kappa and two had lambda light chain expression. Three cases expressed CD56. Two patients had a complex karyotype. In conclusion, the frequency of IgG4 myeloma correlates with the normal distribution of IgG4 isoform. The patients with IgG4 myeloma appear to have a high rate of plasmablastic morphology and could be predisposed to necrotizing fasciitis. Despite high serum levels of IgG4, none had evidence of IgG4-related disease. These findings suggest that the increased number of IgG4-positive plasma cells is not the primary etiologic agent in IgG4-related disease. Elevated serum levels of IgG4 is not sufficient to produce the typical disease presentation and should not be considered diagnostic of IgG4-related disease.

Development of Human-Murine Chimeric Immunoglobulin G for Use in the Serological Detection of Human Flavivirus and Alphavirus Antibodies▿

PubMed Central

Thibodeaux, Brett A.; Panella, Amanda N.; Roehrig, John T.

2010-01-01

Diagnosis of human arboviral infections relies heavily on serological techniques such as the immunoglobulin M (IgM) antibody capture enzyme-linked immunosorbent assay (MAC-ELISA) and the indirect IgG ELISA. Broad application of these assays is hindered by the lack of standardized positive human control sera that react with a wide variety of flaviviruses (e.g., dengue, West Nile, yellow fever, Japanese encephalitis, Saint Louis encephalitis, and Powassan viruses), or alphaviruses (e.g., Eastern equine encephalitis, Western equine encephalitis, Venezuelan equine encephalitis, and chikungunya viruses) that can cause human disease. We have created human-murine chimeric monoclonal antibodies (cMAbs) by combining the variable regions of flavivirus (6B6C-1) or alphavirus (1A4B-6) broadly cross-reactive murine MAbs (mMAbs) with the constant region of human IgG1. These cMAbs may be used as standardized reagents capable of replacing human infection-immune-positive control sera in indirect IgG ELISA for diagnosis of all human flaviviral or alphaviral infections. The IgG cMAbs secreted from plasmid-transformed Sp2/0-Ag14 cells had serological activity identical to that of the parent mMAbs, as measured by ELISA using multiple flaviviruses or alphaviruses. PMID:20739503

Development of human-murine chimeric immunoglobulin G for use in the serological detection of human flavivirus and alphavirus antibodies.

PubMed

Thibodeaux, Brett A; Panella, Amanda N; Roehrig, John T

2010-10-01

Diagnosis of human arboviral infections relies heavily on serological techniques such as the immunoglobulin M (IgM) antibody capture enzyme-linked immunosorbent assay (MAC-ELISA) and the indirect IgG ELISA. Broad application of these assays is hindered by the lack of standardized positive human control sera that react with a wide variety of flaviviruses (e.g., dengue, West Nile, yellow fever, Japanese encephalitis, Saint Louis encephalitis, and Powassan viruses), or alphaviruses (e.g., Eastern equine encephalitis, Western equine encephalitis, Venezuelan equine encephalitis, and chikungunya viruses) that can cause human disease. We have created human-murine chimeric monoclonal antibodies (cMAbs) by combining the variable regions of flavivirus (6B6C-1) or alphavirus (1A4B-6) broadly cross-reactive murine MAbs (mMAbs) with the constant region of human IgG1. These cMAbs may be used as standardized reagents capable of replacing human infection-immune-positive control sera in indirect IgG ELISA for diagnosis of all human flaviviral or alphaviral infections. The IgG cMAbs secreted from plasmid-transformed Sp2/0-Ag14 cells had serological activity identical to that of the parent mMAbs, as measured by ELISA using multiple flaviviruses or alphaviruses.

Enhanced HIV-1 neutralization by a CD4-VH3-IgG1 fusion protein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meyuhas, Ronit; Noy, Hava; Fishman, Sigal

2009-08-21

HIV-1 gp120 is an alleged B cell superantigen, binding certain VH3+ human antibodies. We reasoned that a CD4-VH3 fusion protein could possess higher affinity for gp120 and improved HIV-1 inhibitory capacity. To test this we produced several human IgG1 immunoligands harboring VH3. Unlike VH3-IgG1 or VH3-CD4-IgG1, CD4-VH3-IgG1 bound gp120 considerably stronger than CD4-IgG1. CD4-VH3-IgG1 exhibited {approx}1.5-2.5-fold increase in neutralization of two T-cell laboratory-adapted strains when compared to CD4-IgG1. CD4-VH3-IgG1 improved neutralization of 7/10 clade B primary isolates or pseudoviruses, exceeding 20-fold for JR-FL and 13-fold for Ba-L. It enhanced neutralization of 4/8 clade C viruses, and had negligible effect onmore » 1/4 clade A pseudoviruses. We attribute this improvement to possible pairing of VH3 with CD4 D1 and stabilization of an Ig Fv-like structure, rather than to superantigen interactions. These novel findings support the current notion that CD4 fusion proteins can act as better HIV-1 entry inhibitors with potential clinical implications.« less

Delivery route determines the presence of immune complexes on umbilical cord erythrocytes.

PubMed

de Lima, Andrés; Franco, Luis C; Sarmiento, Andrés; González, John M

2017-11-01

Umbilical cord blood offers a unique opportunity to study the basal level of immunoglobulin complexes. This study aims to determine the presence of immune complexes and complement deposition on erythrocytes from umbilical cord blood from normal, full-term pregnancies. In vitro pre-formed IgA, IgG, and IgM complexes were used as positive control for flow cytometry detection, and for C3d deposition. Blood samples (34) of umbilical cord blood taken from vaginal and cesarean deliveries were tested for the presence of immunoglobulin complexes. Fourteen samples from vaginal deliveries and 20 samples from cesarean deliveries were assessed. IgG and IgM complexes were detected on erythrocytes, whereas no IgA complexes or complement deposition was observed. Interestingly, the percentage of IgG complexes was higher on erythrocytes from vaginal delivery samples compared to those from cesarean deliveries. No other associations between immune complexes and other maternal or newborn variables were found. IgG and IgM complexes seem to be normally present on umbilical cord erythrocytes. Erythrocytes from vaginal deliveries have a higher percentage of IgG complexes present compared to that from cesarean deliveries. Since no C3d activity was detected, these complexes are non-pathological and should be part of the newborn's initial innate immune response.

Electrochemical analysis of gold-coated magnetic nanoparticles for detecting immunological interaction

NASA Astrophysics Data System (ADS)

Pham, Thao Thi-Hien; Sim, Sang Jun

2010-01-01

An electrochemical impedance immunosensor was developed for detecting the immunological interaction between human immunoglobulin (IgG) and protein A from Staphylococcus aureus based on the immobilization of human IgG on the surface of modified gold-coated magnetic nanoparticles. The nanoparticles with an Au shell and Fe oxide cores were functionalized by a self-assembled monolayer of 11-mercaptoundecanoic acid. The electrochemical analysis was conducted on the modified magnetic carbon paste electrodes with the nanoparticles. The magnetic nanoparticles were attached to the surface of the magnetic carbon paste electrodes via magnetic force. The cyclic voltammetry technique and electrochemical impedance spectroscopy measurements of the magnetic carbon paste electrodes coated with magnetic nanoparticles-human IgG complex showed changes in its alternating current (AC) response both after the modification of the surface of the electrode and the addition of protein A. The immunological interaction between human IgG on the surface of the modified magnetic carbon paste electrodes and protein A in the solution could be successfully monitored.

Lea blood group antigen on human platelets.

PubMed

Dunstan, R A; Simpson, M B; Rosse, W F

1985-01-01

One- and two-stage radioligand assays were used to determine if human platelets possess the Lea antigen. Goat IgG anti-Lea antibody was purified by multiple adsorptions with Le(a-b-) human red blood cells, followed by affinity chromatography with synthetic Lea substance and labeling with 125I. Human IgG anti-Lea antibody was used either in a two stage radioassay with 125I-labeled mouse monoclonal IgG anti-human IgG as the second antibody or, alternatively, purified by Staph protein A chromatography, labeled with 125I, and used in a one-stage radioassay. Platelets from donors of appropriate red blood cell phenotypes were incubated with the antisera, centrifuged through phthalate esters, and assayed in a gamma scintillation counter. Dose response and saturation curve analysis demonstrate the presence of Lewis a antigen on platelets from Lea+ donors. Furthermore, platelets from an Le(a-b-) donor incubated in Le (a+b-) plasma adsorb Lea antigen in a similar manner to red blood cells. The clinical significance of these antigens in platelet transfusion remains undefined.

[Identification of NMDA receptor in normal bovine ovary and ovum].

PubMed

Tachibana, Naoko; Ikeda, Shu-ichi

2014-01-01

To clarify the pathogenesis of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis in patients without ovarian teratoma, we investigate normal human ovary, normal bovine ovary and bovine ova. On the basis of immunohistochemical studies, normal human ovary expressed NR2B epitope in primordial oocytes. The results of SDS-PAGE and immunoblotting using bovine ovarian tissues and ova, we identified two bands of NR1 and NR2B. Moreover, reverse phase liquid chromatography coupled to tandem mass spectrometry showed peptides fractions of NR1, NR2A, NR2B and NR2C. Immunocytochemical study disclosed that normal bovine oocyte has a strong affinity for a patient's disease-specific IgG. Anti-NMDAR encephalitis involves mainly young women who are in their reproductive age. Ovarian teratoma is important as simultaneous tumor, the percentage of patients with ovarian teratoma is less than 40%. It is obvious that the origin of ovarian teratoma is oocyte. So the existence of NMDAR in normal oocytes is very important to assert that ovary itself is the antigen presenting tissue. And also it is helpful to explain why young women are mainly affected from this disease. It seems to conclude that anti-NMDAR encephalitis is one form of autoimmune synaptic encephalitis and that the antigen presenting tissue is ovary itself.

Quantitative blood group typing using surface plasmon resonance.

PubMed

Then, Whui Lyn; Aguilar, Marie-Isabel; Garnier, Gil

2015-11-15

The accurate and reliable typing of blood groups is essential prior to blood transfusion. While current blood typing methods are well established, results are subjective and heavily reliant on analysis by trained personnel. Techniques for quantifying blood group antibody-antigen interactions are also very limited. Many biosensing systems rely on surface plasmon resonance (SPR) detection to quantify biomolecular interactions. While SPR has been widely used for characterizing antibody-antigen interactions, measuring antibody interactions with whole cells is significantly less common. Previous studies utilized SPR for blood group antigen detection, however, showed poor regeneration causing loss of functionality after a single use. In this study, a fully regenerable, multi-functional platform for quantitative blood group typing via SPR detection is achieved by immobilizing anti-human IgG antibody to the sensor surface, which binds to the Fc region of human IgG antibodies. The surface becomes an interchangeable platform capable of quantifying the blood group interactions between red blood cells (RBCs) and IgG antibodies. As with indirect antiglobulin tests (IAT), which use IgG antibodies for detection, IgG antibodies are initially incubated with RBCs. This facilitates binding to the immobilized monolayer and allows for quantitative blood group detection. Using the D-antigen as an example, a clear distinction between positive (>500 RU) and negative (<100 RU) RBCs is achieved using anti-D IgG. Complete regeneration of the anti-human IgG surface is also successful, showing negligible degradation of the surface after more than 100 regenerations. This novel approach is validated with human-sourced whole blood samples to demonstrate an interesting alternative for quantitative blood grouping using SPR analysis. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

Serum IgG, IgM and slow alpha-globulin levels in carrageenan-treated rats.

PubMed Central

Fowler, E. F.; Thomson, A. W.

1979-01-01

Serum levels of IgM, IgG, slow alpha 1- and slow alpha 2-globulins were measured either by quantitative radial immunodiffusion (IgG) or immunoelectrophoresis (IgM and slow alpha-globulins) during the 3-week period after i.p. injection of 50 mg potassium carrageenan. There was a significant elevation in levels of IgM and slow alpha 1-globulin, maximal on Day 4 and returning to normal by Day 14. Slow alpha 2-globulin was detectable within 24 h, reached a peak at Day 2, and was no longer measurable in most rats by Day 14. Levels of IgG however, were unaffected by carrageenan injection. PMID:92333

Human IgG2 antibodies against epidermal growth factor receptor effectively trigger antibody-dependent cellular cytotoxicity but, in contrast to IgG1, only by cells of myeloid lineage.

PubMed

Schneider-Merck, Tanja; Lammerts van Bueren, Jeroen J; Berger, Sven; Rossen, Kai; van Berkel, Patrick H C; Derer, Stefanie; Beyer, Thomas; Lohse, Stefan; Bleeker, Wim K; Peipp, Matthias; Parren, Paul W H I; van de Winkel, Jan G J; Valerius, Thomas; Dechant, Michael

2010-01-01

Ab-dependent cellular cytotoxicity (ADCC) is usually considered an important mechanism of action for immunotherapy with human IgG1 but not IgG2 Abs. The epidermal growth factor receptor (EGF-R) Ab panitumumab represents the only human IgG2 Ab approved for immunotherapy and inhibition of EGF-R signaling has been described as its principal mechanism of action. In this study, we investigated effector mechanisms of panitumumab compared with zalutumumab, an EGF-R Ab of the human IgG1 isotype. Notably, panitumumab was as effective as zalutumumab in recruiting ADCC by myeloid effector cells (i.e., neutrophils and monocytes) in contrast to NK cell-mediated ADCC, which was only induced by the IgG1 Ab. Neutrophil-mediated tumor cell killing could be stimulated by myeloid growth factors and was triggered via FcgammaRIIa. Panitumumab-mediated ADCC was significantly affected by the functional FcgammaRIIa-R131H polymorphism and was induced more effectively by neutrophils from FcgammaRIIa-131H homozygous donors than from -131R individuals. This polymorphism did not affect neutrophil ADCC induced by the IgG1 Ab zalutumumab. The in vivo activity of both Abs was assessed in two animal models: a high-dose model, in which signaling inhibition is a dominant mechanism of action, and a low-dose model, in which effector cell recruitment plays a prominent role. Zalutumumab was more effective than panitumumab in the high-dose model, reflecting its stronger ability to induce EGF-R downmodulation and growth inhibition. In the low-dose model, zalutumumab and panitumumab similarly prevented tumor growth. Thus, our results identify myeloid cell-mediated ADCC as a potent and additional mechanism of action for EGF-R-directed immunotherapy.

Low-affinity FcγR interactions can decide the fate of novel human IgG-sensitised red blood cells and platelets.

PubMed

Armour, Kathryn L; Smith, Cheryl S; Turner, Craig P; Kirton, Christopher M; Wilkes, Anthony M; Hadley, Andrew G; Ghevaert, Cedric; Williamson, Lorna M; Clark, Michael R

2014-03-01

G1Δnab is a mutant human IgG1 constant region with a lower ability to interact with FcγR than the natural IgG constant regions. Radiolabelled RBCs and platelets sensitised with specific G1Δnab Abs were cleared more slowly from human circulation than IgG1-sensitised counterparts. However, non-destructive splenic retention of G1Δnab-coated RBCs required investigation and plasma radioactivities now suggest this also occurred for platelets sensitised with an IgG1/G1Δnab mixture. In vitro assays with human cells showed that G1Δnab-sensitised RBCs did not cause FcγRI-mediated monocyte activation, FcγRIIIa-mediated antibody-dependent cell-mediated cytotoxicity (ADCC) or macrophage phagocytosis although they did adhere to macrophages. Thus, FcγRII was implicated in the adhesion despite the Δnab mutation reducing the already low-affinity binding to this receptor class. Additional contacts via P-selectin enhance the interaction of sensitised platelets with monocytes and this system provided evidence of FcγRII-dependent activation by G1Δnab. These results emphasise the physiological relevance of low-affinity interactions: It appears that FcγRII interactions of G1Δnab allowed splenic retention of G1Δnab-coated RBCs with inhibitory FcγRIIb binding preventing RBC destruction and that FcγRIIb engagement by G1Δnab on IgG1/G1Δnab-sensitised platelets overcame activation by IgG1. Considering therapeutic blocking Abs, G1Δnab offers lower FcγR binding and a greater bias towards inhibition than IgG2 and IgG4 constant regions. © 2013 The Authors. European Journal of Immunology published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mapping of IgE and IgG4 antibody-binding epitopes in Cyn d 1, the major allergen of Bermuda grass pollen.

PubMed

Yuan, Han-Chih; Wu, Keh-Gong; Chen, Chun-Jen; Su, Song-Nan; Shen, Horng-Der; Chen, Yann-Jang; Peng, Ho-Jen

2012-01-01

Bermuda grass pollen (BGP) is an important seasonal aeroallergen worldwide which induces allergic disorders such as allergic rhinitis, conjunctivitis and asthma. Cyn d 1 is the major allergen of BGP. This study is aimed to map human IgE and IgG(4) antibody-binding sequential epitopes on Cyn d 1 by dot immunoblotting. Synthetic peptides (10-mers; 5 overlapping residues) spanning the full length of Cyn d 1 were used for dot immunoblotting to map human IgE and IgG(1-4) antibody-binding regions with sera from BGP-allergic patients. Synthetic peptides with more overlapping residues were used for further mapping. Essential amino acids in each epitope were examined by single amino acid substitution with alanine. Peptides with sequence polymorphism of epitopes of Cyn d 1 were also synthesized to extrapolate their differences in binding capability. Four major IgE-binding epitopes (peptides 15(-1), 21, 33(-2) and 35(+1), corresponding to amino acids 70-79, 101-110, 159-167 and 172-181) and 5 major IgG(4)-binding epitopes (peptides 15(-1), 30(-2), 33(-2), 35(+1) and 39, corresponding to amino acids 70-79, 144-153, 159-167, 172-181 and 192-200) were identified. They are all located on the surface of the simulated Cyn d 1 molecule, and three of them are major epitopes for both IgE and IgG(4). Their critical amino acids were all characterized. Major epitopes for human IgG(1) to IgG(4) are almost identical. This is the first study to map the sequential epitopes for human IgE and IgG(4) subclasses in Cyn d 1. It will be helpful for future development in immunotherapy and diagnosis. Copyright © 2011 S. Karger AG, Basel.

Time resolved native ion-mobility mass spectrometry to monitor dynamics of IgG4 Fab arm exchange and "bispecific" monoclonal antibody formation.

PubMed

Debaene, François; Wagner-Rousset, Elsa; Colas, Olivier; Ayoub, Daniel; Corvaïa, Nathalie; Van Dorsselaer, Alain; Beck, Alain; Cianférani, Sarah

2013-10-15

Monoclonal antibodies (mAbs) and derivatives such as antibody-drug conjugates (ADC) and bispecific antibodies (bsAb), are the fastest growing class of human therapeutics. Most of the therapeutic antibodies currently on the market and in clinical trials are chimeric, humanized, and human immunoglobulin G1 (IgG1). An increasing number of IgG2s and IgG4s that have distinct structural and functional properties are also investigated to develop products that lack or have diminished antibody effector functions compared to IgG1. Importantly, wild type IgG4 has been shown to form half molecules (one heavy chain and one light chain) that lack interheavy chain disulfide bonds and form intrachain disulfide bonds. Moreover, IgG4 undergoes a process of Fab-arm exchange (FAE) in which the heavy chains of antibodies of different specificities can dissociate and recombine in bispecific antibodies both in vitro and in vivo. Here, native mass spectrometry (MS) and time-resolved traveling wave ion mobility MS (TWIM-MS) were used for the first time for online monitoring of FAE and bsAb formation using Hz6F4-2v3 and natalizumab, two humanized IgG4s which bind to human Junctional Adhesion Molecule-A (JAM-A) and alpha4 integrin, respectively. In addition, native MS analysis of bsAb/JAM-A immune complexes revealed that bsAb can bind up to two antigen molecules, confirming that the Hz6F4 family preferentially binds dimeric JAM-A. Our results illustrate how IM-MS can rapidly assess bsAb structural heterogeneity and be easily implemented into MS workflows for bsAb production follow up and bsAb/antigen complex characterization. Altogether, these results provide new MS-based methodologies for in-depth FAE and bsAb formation monitoring. Native MS and IM-MS will play an increasing role in next generation biopharmaceutical product characterization like bsAbs, antibody mixtures, and antibody-drug conjugates (ADC) as well as for biosimilar and biobetter antibodies.

Antibody degradation in tobacco plants: a predominantly apoplastic process

PubMed Central

2011-01-01

Background Interest in using plants for production of recombinant proteins such as monoclonal antibodies is growing, but proteolytic degradation, leading to a loss of functionality and complications in downstream purification, is still a serious problem. Results In this study, we investigated the dynamics of the assembly and breakdown of a human IgG1κ antibody expressed in plants. Initial studies in a human IgG transgenic plant line suggested that IgG fragments were present prior to extraction. Indeed, when the proteolytic activity of non-transgenic Nicotiana tabacum leaf extracts was tested against a human IgG1 substrate, little activity was detectable in extraction buffers with pH > 5. Significant degradation was only observed when the plant extract was buffered below pH 5, but this proteolysis could be abrogated by addition of protease inhibitors. Pulse-chase analysis of IgG MAb transgenic plants also demonstrated that IgG assembly intermediates are present intracellularly and are not secreted, and indicates that the majority of proteolytic degradation occurs following secretion into the apoplastic space. Conclusions The results provide evidence that proteolytic fragments derived from antibodies of the IgG subtype expressed in tobacco plants do not accumulate within the cell, and are instead likely to occur in the apoplastic space. Furthermore, any proteolytic activity due to the release of proteases from subcellular compartments during tissue disruption and extraction is not a major consideration under most commonly used extraction conditions. PMID:22208820

The different effector function capabilities of the seven equine IgG subclasses have implications for vaccine strategies

PubMed Central

Lewis, Melanie J.; Wagner, Bettina; Woof, Jenny M.

2008-01-01

Recombinant versions of the seven equine IgG subclasses were expressed in CHO cells. All assembled into intact immunoglobulins stabilised by disulphide bridges, although, reminiscent of human IgG4, a small proportion of equine IgG4 and IgG7 were held together by non-covalent bonds alone. All seven IgGs were N-glycosylated. In addition IgG3 appeared to be O-glycosylated and could bind the lectin jacalin. Staphylococcal protein A displayed weak binding for the equine IgGs in the order: IgG1 > IgG3 > IgG4 > IgG7 > IgG2 = IgG5 > IgG6. Streptococcal protein G bound strongly to IgG1, IgG4 and IgG7, moderately to IgG3, weakly to IgG2 and IgG6, and not at all to IgG5. Analysis of antibody effector functions revealed that IgG1, IgG3, IgG4, IgG5 and IgG7, but not IgG2 and IgG6, were able to elicit a strong respiratory burst from equine peripheral blood leukocytes, predicting that the former five IgG subclasses are able to interact with Fc receptors on effector cells. IgG1, IgG3, IgG4 and IgG7, but not IgG2, IgG5 and IgG6, were able to bind complement C1q and activate complement via the classical pathway. The differential effector function capabilities of the subclasses suggest that, for maximum efficacy, equine vaccine strategies should seek to elicit antibody responses of the IgG1, IgG3, IgG4, and IgG7 subclasses. PMID:17669496

Abnormal serum IgG subclass pattern in children with Down's syndrome.

PubMed

Annerén, G; Magnusson, C G; Lilja, G; Nordvall, S L

1992-05-01

Susceptibility to infections is a well known feature of Down's syndrome. The possible relation between this predisposition and the serum concentrations of the IgG subclasses was studied in 38 children with Down's syndrome aged 1-12 years. An age matched group of 50 healthy children served as controls. The serum concentrations of IgG1 and IgG3 were significantly raised among children with Down's syndrome in all three age groups studied (that is 1-2.5, 4-8, and 9-12 years). The serum concentrations of IgG2 were normal in the first two groups but significantly reduced in the third age group. In contrast, the concentrations of IgG4 among children with Down's syndrome were significantly reduced in all three age groups. Moreover, among the children with Down's syndrome aged 4-12 years 68% (15/22) had IgG4 concentrations below 2 SDs of the geometrical mean of the controls. The results may partially explain the proneness of children with Down's syndrome to infections with encapsulated bacteria. Although the underlying cause of these abnormalities is unknown, IgG subclass determination seems relevant in the clinical evaluation of children with Down's syndrome.

Abnormal serum IgG subclass pattern in children with Down's syndrome.

PubMed Central

Annerén, G; Magnusson, C G; Lilja, G; Nordvall, S L

1992-01-01

Susceptibility to infections is a well known feature of Down's syndrome. The possible relation between this predisposition and the serum concentrations of the IgG subclasses was studied in 38 children with Down's syndrome aged 1-12 years. An age matched group of 50 healthy children served as controls. The serum concentrations of IgG1 and IgG3 were significantly raised among children with Down's syndrome in all three age groups studied (that is 1-2.5, 4-8, and 9-12 years). The serum concentrations of IgG2 were normal in the first two groups but significantly reduced in the third age group. In contrast, the concentrations of IgG4 among children with Down's syndrome were significantly reduced in all three age groups. Moreover, among the children with Down's syndrome aged 4-12 years 68% (15/22) had IgG4 concentrations below 2 SDs of the geometrical mean of the controls. The results may partially explain the proneness of children with Down's syndrome to infections with encapsulated bacteria. Although the underlying cause of these abnormalities is unknown, IgG subclass determination seems relevant in the clinical evaluation of children with Down's syndrome. PMID:1534650

Antiviral Functions of Human Immunodeficiency Virus Type 1 (HIV-1)-Specific IgG Antibodies: Effects of Antiretroviral Therapy and Implications for Therapeutic HIV-1 Vaccine Design

PubMed Central

French, Martyn A.; Tjiam, M. Christian; Abudulai, Laila N.; Fernandez, Sonia

2017-01-01

Contemporary antiretroviral therapy (ART) is effective and tolerable for long periods of time but cannot eradicate human immunodeficiency virus type 1 (HIV-1) infection by either elimination of viral reservoirs or enhancement of HIV-1-specific immune responses. Boosting “protective” HIV-1-specific immune responses by active or passive immunization will therefore be necessary to control or eradicate HIV-1 infection and is currently the topic of intense investigation. Recently reported studies conducted in HIV patients and non-human primate (NHP) models of HIV-1 infection suggest that HIV-1-specific IgG antibody responses may contribute to the control of HIV-1 infection. However, production of IgG antibodies with virus neutralizing activity by vaccination remains problematic and while vaccine-induced natural killer cell-activating IgG antibodies have been shown to prevent the acquisition of HIV-1 infection, they may not be sufficient to control or eradicate established HIV-1 infection. It is, therefore, important to consider other functional characteristics of IgG antibody responses. IgG antibodies to viruses also mediate opsonophagocytic antibody responses against virions and capsids that enhance the function of phagocytic cells playing critical roles in antiviral immune responses, particularly conventional dendritic cells and plasmacytoid dendritic cells. Emerging evidence suggests that these antibody functions might contribute to the control of HIV-1 infection. In addition, IgG antibodies contribute to the intracellular degradation of viruses via binding to the cytosolic fragment crystallizable (Fc) receptor tripartite motif containing-21 (TRIM21). The functional activity of an IgG antibody response is influenced by the IgG subclass content, which affects binding to antigens and to Fcγ receptors on phagocytic cells and to TRIM21. The IgG subclass content and avidity of IgG antibodies is determined by germinal center (GC) reactions in follicles of lymphoid tissue. As HIV-1 infects cells in GCs and induces GC dysfunction, which may persist during ART, strategies for boosting HIV-1-specific IgG antibody responses should include early commencement of ART and possibly the use of particular antiretroviral drugs to optimize drug levels in lymphoid follicles. Finally, enhancing particular functions of HIV-1-specific IgG antibody responses by using adjuvants or cytokines to modulate the IgG subclass content of the antibody response might be investigated in NHP models of HIV-1 infection and during trials of therapeutic vaccines in HIV patients. PMID:28725225

Chronic active VZV infection manifesting as zoster sine herpete, zoster paresis and myelopathy.

PubMed

Morita, Y; Osaki, Y; Doi, Y; Forghani, B; Gilden, D H

2003-08-15

After lumbar-distribution zoster, an HTLV-1-seropositive woman developed chronic radicular sacral-distribution pain (zoster sine herpete), cervical-distribution zoster paresis and thoracic-distribution myelopathy. Detection of anti-varicella zoster virus (VZV) IgM and VZV IgG antibody in cerebrospinal fluid (CSF), with reduced serum/CSF ratios of anti-VZV IgG compared to normal serum/CSF ratios for albumin and total IgG, proved that VZV caused the protracted neurological complications. Diagnosis by antibody testing led to aggressive antiviral treatment and a favorable outcome.

Serological diagnosis of Epstein-Barr virus infection: Problems and solutions

PubMed Central

De Paschale, Massimo; Clerici, Pierangelo

2012-01-01

Serological tests for antibodies specific for Epstein-Barr virus (EBV) antigens are frequently used to define infection status and for the differential diagnosis of other pathogens responsible for mononucleosis syndrome. Using only three parameters [viral capsid antigen (VCA) IgG, VCA IgM and EBV nuclear antigen (EBNA)-1 IgG],it is normally possible to distinguish acute from past infection: the presence of VCA IgM and VCA IgG without EBNA-1 IgG indicates acute infection, whereas the presence of VCA IgG and EBNA-1 IgG without VCA IgM is typical of past infection. However, serological findings may sometimes be difficult to interpret as VCA IgG can be present without VCA IgM or EBNA-1 IgG in cases of acute or past infection, or all the three parameters may be detected simultaneously in the case of recent infection or during the course of reactivation. A profile of isolated EBNA-1 IgG may also create some doubts. In order to interpret these patterns correctly, it is necessary to determine IgG avidity, identify anti-EBV IgG and IgM antibodies by immunoblotting, and look for heterophile antibodies, anti-EA (D) antibodies or viral genome using molecular biology methods. These tests make it possible to define the status of the infection and solve any problems that may arise in routine laboratory practice. PMID:24175209

Surface receptors on neutrophils and monocytes from immunodeficient and normal horses.

PubMed Central

Banks, K L; McGuire, T C

1975-01-01

Surface receptors on peripheral blood neutrophils and monocytes from normal and immunodeficient horses have been studied. Sheep erythrocytes (SRBC) coated with IgG, IgM, and complement but not IgG(T), readily bound to normal equine monocytes and neutrophils. More than 4000 molecules of IgG were required to sensitize each SRBC for adherence to monocytes, and more than 12,000 molecules were required for adherence to neutrophils. Young horses with a severe combined immunodeficiency had an almost total absence of lymphocytes, but normal numbers of monocytes and neutrophils. The number of receptors for immunoglobulin, complement, and phytolectin on monocytes and neutrophils from immunodeficient animals were similar to those on the cells of normal horses. Although the precursor cells of lymphocytes of horses with combined immunodeficiency appear to be defective, no defect in the other cellular products of the bone marrow were apparent. PMID:1126740

Antibody responses of red wolves to canine distemper virus and canine parvovirus vaccination.

PubMed

Harrenstien, L A; Munson, L; Ramsay, E C; Lucash, C F; Kania, S A; Potgieter, L N

1997-07-01

Twenty captive red wolves (Canis rufus), including 16 intended for release into Great Smoky Mountains National Park, Cades Cove, Tennessee (USA), and four housed at Knoxville Zoological Gardens, Inc., Knoxville, Tennessee, were evaluated for immunologic response to vaccination between June 1994 and April 1995. Wolves were vaccinated with modified-live (MLV) canine distemper virus (CDV) and canine parvovirus type-2 (CPV2). Sera were collected, and immunofluorescent staining was performed for determination of immunoglobulin titers (CDV IgM, CDV IgG, and CPV2 IgG). A capture enzyme-linked immunosorbent assay was performed for validation purposes, to confirm the reactivity of our standard diagnostic reagents with red wolf serum. All wolves produced a measurable antibody response to CDV and CPV2 vaccination. Titers against CDV and CPV2 varied widely among individual wolves, but between-litter differences in mean titers were not significant. No consistent response between the degree of response to CDV versus CPV2 vaccination was observed in individual wolves. No differences were seen between IgG responses of pups vaccinated with univalent vaccines given concurrently or during alternating weeks. Pups had an IgG response to CDV and CPV2 vaccination as early as 9 wk of age. Mean post-vaccination IgG titers against CDV were at or above the level normally measured in vaccinated domestic dogs. Mean post-vaccination IgG titers against CPV2 were below the level normally measured in domestic dogs. Adult previously-vaccinated wolves had measurable CDV and CPV2 IgG titers more than 1 yr after vaccination, but did not have significant IgG titer increases after revaccination. We conclude that red wolves are capable of producing an antibody response after vaccination with commercial canine products but that their response to CPV2 vaccination was minimal. This response can be assayed using tests developed for domestic dogs.

Bovine IgG subclasses and fertility of Echinococcus granulosus hydatid cysts.

PubMed

Riesle, Silke; García, María Pía; Hidalgo, Christian; Galanti, Norbel; Saenz, Leonardo; Paredes, Rodolfo

2014-09-15

Hydatidosis is an important zoonotic disease of worldwide distribution, causing important health problems to humans and major economical losses in infected livestock. Echinococcus granulosus, the etiological agent of hydatid disease, induces a humoral immune response in the intermediate host (human and herbivorous) against hydatid cyst antigens. Specifically, IgGs are found in the laminar and germinal layers and inside the lumen of fertile and infertile hydatid cysts. In the germinal layer of infertile cysts IgGs are found in an order of magnitude greater than in the germinal layer of fertile cysts; a fraction of those IgGs are associated with high affinity to germinal layer proteins, suggesting their binding to specific parasite antigens. We have previously shown that those immunoglobulins, bound with high affinity to the germinal layer of hydatid cysts, induce apoptosis leading to cyst infertility. In the present work the presence of IgG1 and IgG2 subclasses in the germinal layer of both fertile and infertile hydatid cysts is reported. IgG1 is the most relevant immunoglobulin subclass present in the germinal layer of infertile cysts and bound with high affinity to that parasite structure. Contrarily, though the IgG2 subclass was also found in the germinal and adventitial layers, those immunoglobulins show low affinity to parasite antigens. We propose that the binding of an IgG1 subclass to parasite antigens present in the germinal layer is involved in the mechanism of cyst infertility. Copyright © 2014 Elsevier B.V. All rights reserved.

Biochemical and immunochemical analyses of detergent solubilized antigens from membrane vesicles of Aspergillus fumigatus.

PubMed

Piechura, J E; Riefel, R S; Daft, L J

1987-11-01

A membrane vesicle fraction isolated from exponentially growing Aspergillus fumigatus strain Ag 507 cultures was obtained by mechanical disruption of intact Aspergillus cells under specific osmotic conditions followed by a pH fractionation technique. Electron micrographs of the membrane vesicles indicated unit membrane structures free from cell wall material. High glucose-6-phosphatase and low lactate dehydrogenase activities verified the relative purity of the membrane vesicle fraction. Allergic bronchopulmonary aspergillosis (ABPA) patient and normal human sera were incubated with the membrane vesicle fraction followed by colloidal gold tagged rabbit antiserum to human IgG or IgE. Electron micrographs indicated ABPA patient sera possessed specific IgG and IgE antibodies to membranous components. The detergent octyl-beta-D-glucopyranoside was used to extract membrane vesicle components (MC). The enzyme profile of MC compared with cell sap components (CS) showed differences in types of enzymes. Two-dimensional polyacrylamide gel electrophoretic analyses of MC and CS detected components shared as well as unique to each fraction. In crossed immunoelectrophoresis using both rabbit antisera raised to MC and ABPA patient sera, 5 peaks were detected, while analysis of CS using rabbit antisera raised to CS produced 20 major peaks. Immunoelectrophoresis and double immunodiffusion data supported the crossed immunoelectrophoretic data: MC differed from CS. Enzyme-linked immunosorbent assay indicated high specific IgG and IgE antibody levels to MC in ABPA patient sera. Crossed immuno-affinoelectrophoresis with concanavalin A partially characterized the MC, which consist of components which have glycoprotein elements (i.e., containing alpha-D-glucose or alpha-D-mannose).

Target recognition of beta2-glycoprotein I (beta2GPI)-dependent anticardiolipin antibodies: evidence for involvement of the fourth domain of beta2GPI in antibody binding.

PubMed

George, J; Gilburd, B; Hojnik, M; Levy, Y; Langevitz, P; Matsuura, E; Koike, T; Shoenfeld, Y

1998-04-15

Beta2-glycoprotein I (beta2GPI) is an absolute requirement for the binding of autoimmune anticardiolipin Abs (aCL) to cardiolipin (CL). We evaluated the target recognition of human beta2GPI by IgG derived from two patients with primary and two with secondary antiphospholipid syndrome. The total IgG serum fractions and beta2GPI affinity-purified IgGs were assessed by using various domain-deleted mutants (DM) of human beta2GPI (DMs: I-III, I-IV, II-V, III-V, IV-V, and V) and mouse mAbs against individual beta2GPI domains. The four IgGs bound slightly to CL in the absence of beta2GPI and showed increased binding in the beta2GPI presence. Following affinity purification of the IgGs on a beta2GPI column, reactivity toward CL was absent. DMs containing domain V inhibited the binding of biotinylated beta2GPI to CL. The addition to CL-coated plates of DM V, but not the other DMs, reduced the binding of all four IgGs. The anti-beta2GPI IgGs bound only to complete beta2GPI and DM I-IV coated on the plates. The binding to plate-adsorbed beta2GPI could be inhibited by complete beta2GPI and DM I-IV, the latter being a more efficient inhibitor. Further, the human anti-beta2GPI IgGs could compete with the binding to beta2GPI of Cof-21 mouse mAb (directed at domain IV), but not with the two other mouse mAbs. The results suggest that some "autoimmune:" beta2GPI-dependent anticardiolipin Abs recognize a beta2GPI target that is distinct from the CL-binding site in domain V. The target site for some antiphospholipid syndrome IgGs appear to reside in domain IV of beta2GPI.

Common idiotypes expressed on human, monoclonal, abnormal immunoglobulins and cryoglobulins with polyreactive autoantibody activities.

PubMed Central

Barbouche, M R; Guilbert, B; Makni, S; Gorgi, Y; Ayed, K; Avrameas, S

1993-01-01

Several human monoclonal immunoglobulins with the same autoantibody activity have been shown to have cross-reactive idiotypes (CRI). In this study, using polyclonal anti-idiotypic antibodies, we found that 28% of human monoclonal immunoglobulins with polyreactive autoantibody activity from myeloma, Waldenström's macroglobulinaemia and cryoglobulinaemia patients shared common idiotype(s). Furthermore, the latter were expressed on human and murine natural MoAbs (respectively in 12% and 22% of the clones tested) and on human IgG preparations used for therapeutic intravenous injections (IVIg) and which contain natural antibodies. These findings suggest that monoclonal immunoglobulins could arise from the proliferation of a clone that normally produces a natural antibody. The existence of common idiotype(s) between monoclonal immunoglobulins and IVIg could be relevant to the improvement noted after treatment with IVIg in patients suffering from peripheral neuropathies associated with monoclonal gammopathy. PMID:8428386

Infectious Mononucleosis Triggers Generation of IgG Auto-Antibodies against Native Myelin Oligodendrocyte Glycoprotein

PubMed Central

Kakalacheva, Kristina; Regenass, Stephan; Wiesmayr, Silke; Azzi, Tarik; Berger, Christoph; Dale, Russell C.; Brilot, Fabienne; Münz, Christian; Rostasy, Kevin; Nadal, David; Lünemann, Jan D.

2016-01-01

A history of infectious mononucleosis (IM), symptomatic primary infection with the Epstein Barr virus, is associated with the development of autoimmune diseases and increases the risk to develop multiple sclerosis. Here, we hypothesized that immune activation during IM triggers autoreactive immune responses. Antibody responses towards cellular antigens using a HEp-2 based indirect immunofluorescence assay and native myelin oligodendrocyte glycoprotein (MOG) using a flow cytometry-based assay were determined in 35 patients with IM and in 23 control subjects. We detected frequent immunoglobulin M (IgM) reactivity to vimentin, a major constituent of the intermediate filament family of proteins, in IM patients (27/35; 77%) but rarely in control subjects (2/23; 9%). IgG autoantibodies binding to HEp-2 cells were absent in both groups. In contrast, IgG responses to native MOG, present in up to 40% of children with inflammatory demyelinating diseases of the central nervous system (CNS), were detectable in 7/35 (20%) patients with IM but not in control subjects. Normalization of anti-vimentin IgM levels to increased total IgM concentrations during IM resulted in loss of significant differences for anti-vimentin IgM titers. Anti-MOG specific IgG responses were still detectable in a subset of three out of 35 patients with IM (9%), even after normalization to increased total IgG levels. Vimentin-specific IgM and MOG-specific IgG responses decreased following clinical resolution of acute IM symptoms. We conclude from our data that MOG-specific memory B cells are activated in subset of patients with IM. PMID:26907324

Infectious Mononucleosis Triggers Generation of IgG Auto-Antibodies against Native Myelin Oligodendrocyte Glycoprotein.

PubMed

Kakalacheva, Kristina; Regenass, Stephan; Wiesmayr, Silke; Azzi, Tarik; Berger, Christoph; Dale, Russell C; Brilot, Fabienne; Münz, Christian; Rostasy, Kevin; Nadal, David; Lünemann, Jan D

2016-02-12

A history of infectious mononucleosis (IM), symptomatic primary infection with the Epstein Barr virus, is associated with the development of autoimmune diseases and increases the risk to develop multiple sclerosis. Here, we hypothesized that immune activation during IM triggers autoreactive immune responses. Antibody responses towards cellular antigens using a HEp-2 based indirect immunofluorescence assay and native myelin oligodendrocyte glycoprotein (MOG) using a flow cytometry-based assay were determined in 35 patients with IM and in 23 control subjects. We detected frequent immunoglobulin M (IgM) reactivity to vimentin, a major constituent of the intermediate filament family of proteins, in IM patients (27/35; 77%) but rarely in control subjects (2/23; 9%). IgG autoantibodies binding to HEp-2 cells were absent in both groups. In contrast, IgG responses to native MOG, present in up to 40% of children with inflammatory demyelinating diseases of the central nervous system (CNS), were detectable in 7/35 (20%) patients with IM but not in control subjects. Normalization of anti-vimentin IgM levels to increased total IgM concentrations during IM resulted in loss of significant differences for anti-vimentin IgM titers. Anti-MOG specific IgG responses were still detectable in a subset of three out of 35 patients with IM (9%), even after normalization to increased total IgG levels. Vimentin-specific IgM and MOG-specific IgG responses decreased following clinical resolution of acute IM symptoms. We conclude from our data that MOG-specific memory B cells are activated in subset of patients with IM.

Infectious and immunologic phenotype of MECP2 duplication syndrome.

PubMed

Bauer, Michael; Kölsch, Uwe; Krüger, Renate; Unterwalder, Nadine; Hameister, Karin; Kaiser, Fabian Marc; Vignoli, Aglaia; Rossi, Rainer; Botella, Maria Pilar; Budisteanu, Magdalena; Rosello, Monica; Orellana, Carmen; Tejada, Maria Isabel; Papuc, Sorina Mihaela; Patat, Oliver; Julia, Sophie; Touraine, Renaud; Gomes, Thusari; Wenner, Kirsten; Xu, Xiu; Afenjar, Alexandra; Toutain, Annick; Philip, Nicole; Jezela-Stanek, Aleksandra; Gortner, Ludwig; Martinez, Francisco; Echenne, Bernard; Wahn, Volker; Meisel, Christian; Wieczorek, Dagmar; El-Chehadeh, Salima; Van Esch, Hilde; von Bernuth, Horst

2015-02-01

MECP2 (methyl CpG binding protein 2) duplication causes syndromic intellectual disability. Patients often suffer from life-threatening infections, suggesting an additional immunodeficiency. We describe for the first time the detailed infectious and immunological phenotype of MECP2 duplication syndrome. 17/27 analyzed patients suffered from pneumonia, 5/27 from at least one episode of sepsis. Encapsulated bacteria (S.pneumoniae, H.influenzae) were frequently isolated. T-cell immunity showed no gross abnormalities in 14/14 patients and IFNy-secretion upon ConA-stimulation was not decreased in 6/7 patients. In 6/21 patients IgG2-deficiency was detected - in 4/21 patients accompanied by IgA-deficiency, 10/21 patients showed low antibody titers against pneumococci. Supra-normal IgG1-levels were detected in 11/21 patients and supra-normal IgG3-levels were seen in 8/21 patients - in 6 of the patients as combined elevation of IgG1 and IgG3. Three of the four patients with IgA/IgG2-deficiency developed multiple severe infections. Upon infections pronounced acute-phase responses were common: 7/10 patients showed CRP values above 200 mg/l. Our data for the first time show systematically that increased susceptibility to infections in MECP2 duplication syndrome is associated with IgA/IgG2-deficiency, low antibody titers against pneumococci and elevated acute-phase responses. So patients with MECP2 duplication syndrome and low IgA/IgG2 may benefit from prophylactic substitution of sIgA and IgG.

External apical root resorption diagnosis by using FII human dentine fraction and salivary IGg.

PubMed

Da-Costa, Tânia Maris Pedrini Soares; Hidalgo, Mirian Marubayashi; Consolaro, Alberto; Lima, Carlos Eduardo de Oliveira; Tanaka, Evelise Ono; Itano, Eiko Nakagawa

2018-06-01

External apical root resorption as a consequence of orthodontic treatment is an inflammatory pathological process that results in permanent loss of tooth structure from the root apex. This study aimed to investigate the diagnostic potential of human dentine fractions and salivary IgG in external apical root resorption. Saliva samples were collected from 10 patients before (T0) and after 3 (T3), 6 (T6) and 12 (T12) months of orthodontic treatment. The total dentinal extract, obtained from human third molars, was fractioned by gel filtration chromatography in three fractions denominated FI, FII and FIII. The root resorption analysis of the upper central incisors was performed by digital image subtraction method. Reactivity of salivary IgG to antigenic fractions of dentine was determined by enzyme-linked immunosorbent assay (Elisa). Regardless of treatment, FI dentin fraction with high MM (<300kDa) was the one that presented highest reactivity with salivary IgG. However, it was found higher salivary IgG reactivity for FII (69 to 45 kilodalton [kDa]) as compared to FIII (<45kDa) at (T6) and (T12), (P<0.05), the same periods in that the root resorptions were detected. Our results suggest that FII human dentine fraction and salivary IgG have potential to be used in diagnosis and monitoring of external apical root resorption. The development of a practical and accessible biochemical test using saliva and FII dentine fraction may help in the prevention of severe root resorption. Copyright © 2018. Published by Elsevier Masson SAS.

What's Normal? Immune Profiling of Human Milk from Healthy Women Living in Different Geographical and Socioeconomic Settings.

PubMed

Ruiz, Lorena; Espinosa-Martos, Irene; García-Carral, Cristina; Manzano, Susana; McGuire, Michelle K; Meehan, Courtney L; McGuire, Mark A; Williams, Janet E; Foster, James; Sellen, Daniel W; Kamau-Mbuthia, Elizabeth W; Kamundia, Egidioh W; Mbugua, Samwel; Moore, Sophie E; Kvist, Linda J; Otoo, Gloria E; Lackey, Kimberly A; Flores, Katherine; Pareja, Rossina G; Bode, Lars; Rodríguez, Juan M

2017-01-01

Human milk provides a very wide range of nutrients and bioactive components, including immune factors, human milk oligosaccharides, and a commensal microbiota. These factors are essential for interconnected processes including immunity programming and the development of a normal infant gastrointestinal microbiome. Newborn immune protection mostly relies on maternal immune factors provided through milk. However, studies dealing with an in-depth profiling of the different immune compounds present in human milk and with the assessment of their natural variation in healthy women from different populations are scarce. In this context, the objective of this work was the detection and quantification of a wide array of immune compounds, including innate immunity factors (IL1β, IL6, IL12, INFγ, TNFα), acquired immunity factors (IL2, IL4, IL10, IL13, IL17), chemokines (IL8, Groα, MCP1, MIP1β), growth factors [IL5, IL7, epidermal growth factor (EGF), granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, TGFβ2], and immunoglobulins (IgA, IgG, IgM), in milk produced by healthy women of different ethnicities living in different geographic, dietary, socioeconomic, and environmental settings. Among the analyzed factors, IgA, IgG, IgM, EGF, TGFβ2, IL7, IL8, Groα, and MIP1β were detected in all or most of the samples collected in each population and, therefore, this specific set of compounds might be considered as the "core" soluble immune factors in milk produced by healthy women worldwide. This approach may help define which immune factors are (or are not) common in milk produced by women living in various conditions, and to identify host, lifestyle, and environmental factors that affect the immunological composition of this complex biological fluid. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT02670278.

What’s Normal? Immune Profiling of Human Milk from Healthy Women Living in Different Geographical and Socioeconomic Settings

PubMed Central

Ruiz, Lorena; Espinosa-Martos, Irene; García-Carral, Cristina; Manzano, Susana; McGuire, Michelle K.; Meehan, Courtney L.; McGuire, Mark A.; Williams, Janet E.; Foster, James; Sellen, Daniel W.; Kamau-Mbuthia, Elizabeth W.; Kamundia, Egidioh W.; Mbugua, Samwel; Moore, Sophie E.; Kvist, Linda J.; Otoo, Gloria E.; Lackey, Kimberly A.; Flores, Katherine; Pareja, Rossina G.; Bode, Lars; Rodríguez, Juan M.

2017-01-01

Human milk provides a very wide range of nutrients and bioactive components, including immune factors, human milk oligosaccharides, and a commensal microbiota. These factors are essential for interconnected processes including immunity programming and the development of a normal infant gastrointestinal microbiome. Newborn immune protection mostly relies on maternal immune factors provided through milk. However, studies dealing with an in-depth profiling of the different immune compounds present in human milk and with the assessment of their natural variation in healthy women from different populations are scarce. In this context, the objective of this work was the detection and quantification of a wide array of immune compounds, including innate immunity factors (IL1β, IL6, IL12, INFγ, TNFα), acquired immunity factors (IL2, IL4, IL10, IL13, IL17), chemokines (IL8, Groα, MCP1, MIP1β), growth factors [IL5, IL7, epidermal growth factor (EGF), granulocyte colony-stimulating factor, granulocyte–macrophage colony-stimulating factor, TGFβ2], and immunoglobulins (IgA, IgG, IgM), in milk produced by healthy women of different ethnicities living in different geographic, dietary, socioeconomic, and environmental settings. Among the analyzed factors, IgA, IgG, IgM, EGF, TGFβ2, IL7, IL8, Groα, and MIP1β were detected in all or most of the samples collected in each population and, therefore, this specific set of compounds might be considered as the “core” soluble immune factors in milk produced by healthy women worldwide. This approach may help define which immune factors are (or are not) common in milk produced by women living in various conditions, and to identify host, lifestyle, and environmental factors that affect the immunological composition of this complex biological fluid. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT02670278. PMID:28713365

MuSK induced experimental autoimmune myasthenia gravis does not require IgG1 antibody to MuSK.

PubMed

Küçükerden, Melike; Huda, Ruksana; Tüzün, Erdem; Yılmaz, Abdullah; Skriapa, Lamprini; Trakas, Nikos; Strait, Richard T; Finkelman, Fred D; Kabadayı, Sevil; Zisimopoulou, Paraskevi; Tzartos, Socrates; Christadoss, Premkumar

2016-06-15

Sera of myasthenia gravis (MG) patients with muscle-specific receptor kinase-antibody (MuSK-Ab) predominantly display the non-complement fixing IgG4 isotype. Similarly, mouse IgG1, which is the analog of human IgG4, is the predominant isotype in mice with experimental autoimmune myasthenia gravis (EAMG) induced by MuSK immunization. The present study was performed to determine whether IgG1 anti-MuSK antibody is required for immunized mice to develop EAMG. Results demonstrated a significant correlation between clinical severity of EAMG and levels of MuSK-binding IgG1+, IgG2+ and IgG3+ peripheral blood B cells in MuSK-immunized wild-type (WT) mice. Moreover, MuSK-immunized IgG1 knockout (KO) and WT mice showed similar EAMG severity, serum MuSK-Ab levels, muscle acetylcholine receptor concentrations, neuromuscular junction immunoglobulin and complement deposit ratios. IgG1 and IgG3 were the predominant anti-MuSK isotypes in WT and IgG1 KO mice, respectively. These observations demonstrate that non-IgG1 isotypes can mediate MuSK-EAMG pathogenesis. Copyright © 2016 Elsevier B.V. All rights reserved.

Cell-mediated lysis of lipid vesicles containing eye muscle protein: Implications regarding pathogenesis of Graves ophthalmopathy*

PubMed Central

Kriss, Joseph P.; Mehdi, S. Qasim

1979-01-01

We prepared artificial vesicles that are lysed upon cell-mediated immunological attack by human lymphocytes. These vesicles are made from a mixture of dimyristoyl lecithin, dipalmitoyl lecithin, and cholesterol, have eye muscle membrane protein (EMP) inserted into the bilayer wall, and contain intravesicular 99mTc marker. Injury to the vesicular membrane was assessed by measurement of 99mTc release. Thyroglobulin (Tg) and Tg-anti-Tg complex (TgA) bind to EMP-vesicles to an extent equal to or greater than to native eye muscle membranes in vitro; this binding requires the presence of normal human IgG. The role of Tg, TgA, IgG, and peripheral blood lymphocytes in altering membrane permeability was analyzed. Incubation of vesicles for up to 3 hr alone, with added IgG alone, or with further addition of Tg or TgA did not result in 99mTc release. Addition of lymphocytes from normal donors to the above four preparations showed release in the presence of TgA. Lymphocytes from each of eight patients with Graves ophthalmopathy caused release not only in the presence of TgA, but also in the presence of Tg. Separation of a patient's lymphocytes into high- and low-affinity rosette-formers (T and K cells, respectively) showed that cell-mediated vesicle lysis in the presence of TgA was greater with K cells than with T cells, while vesicle lysis in the presence of Tg was greater with T cells than with K cells. Vesicles made with inserted Tg but lacking EMP were not lysed by such T cells. Lymphocytes failed to induce permeability changes in vesicles containing other inserted proteins obtained from human nonextraocular muscle, liver, spleen, or adrenal, even if Tg or TgA were present. The results support the concept that muscle cell damage in Graves ophthalmopathy is immunological, cell-mediated, and of two types: (i) K lymphocytes reacting to immune complex, TgA, on the eye muscle cell surface (i.e., antibody-dependent cytotoxicity) and (ii) sensitized T lymphocytes reacting to Tg on the eye muscle cell surface. An antigenic role for EMP is possible, but has not been unequivocally proven. PMID:88053

Human IgG lacking effector functions demonstrate lower FcRn-binding and reduced transplacental transport.

PubMed

Stapleton, Nigel M; Armstrong-Fisher, Sylvia S; Andersen, Jan Terje; van der Schoot, C Ellen; Porter, Charlene; Page, Kenneth R; Falconer, Donald; de Haas, Masja; Williamson, Lorna M; Clark, Michael R; Vidarsson, Gestur; Armour, Kathryn L

2018-03-01

We have previously generated human IgG1 antibodies that were engineered for reduced binding to the classical Fcγ receptors (FcγRI-III) and C1q, thereby eliminating their destructive effector functions (constant region G1Δnab). In their potential use as blocking agents, favorable binding to the neonatal Fc receptor (FcRn) is important to preserve the long half-life typical of IgG. An ability to cross the placenta, which is also mediated, at least in part, by FcRn is desirable in some indications, such as feto-maternal alloimmune disorders. Here, we show that G1Δnab mutants retain pH-dependent binding to human FcRn but that the amino acid alterations reduce the affinity of the IgG1:FcRn interaction by 2.0-fold and 1.6-fold for the two antibodies investigated. The transport of the modified G1Δnab mutants across monolayers of human cell lines expressing FcRn was approximately 75% of the wild-type, except that no difference was observed with human umbilical vein endothelial cells. G1Δnab mutation also reduced transport in an ex vivo placenta model. In conclusion, we demonstrate that, although the G1Δnab mutations are away from the FcRn-binding site, they have long-distance effects, modulating FcRn binding and transcellular transport. Our findings have implications for the design of therapeutic human IgG with tailored effector functions. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Humans have antibodies against a plant virus: evidence from tobacco mosaic virus.

PubMed

Liu, Ruolan; Vaishnav, Radhika A; Roberts, Andrew M; Friedland, Robert P

2013-01-01

Tobacco mosaic virus (TMV), a widespread plant pathogen, is found in tobacco (including cigarettes and smokeless tobacco) as well as in many other plants. Plant viruses do not replicate or cause infection in humans or other mammals. This study was done to determine whether exposure to tobacco products induces an immune response to TMV in humans. Using a sandwich ELISA assay, we detected serum anti-TMV antibodies (IgG, IgG1, IgG3, IgG4, IgA, and IgM) in all subjects enrolled in the study (20 healthy smokers, 20 smokeless-tobacco users, and 20 non-smokers). Smokers had a higher level of serum anti-TMV IgG antibodies than non-smokers, while the serum level of anti-TMV IgA from smokeless tobacco users was lower than smokers and non-smokers. Using bioinformatics, we also found that the human protein TOMM40L (an outer mitochondrial membrane 40 homolog--like translocase) contains a strong homology of six contiguous amino acids to the TMV coat protein, and TOMM40L peptide exhibited cross-reactivity with anti-TMV antibodies. People who smoke cigarettes or other tobacco products experience a lower risk of developing Parkinson's disease, but the mechanism by which this occurs is unclear. Our results showing molecular mimicry between TMV and human TOMM40L raise the question as to whether TMV has a potential role in smokers against Parkinson's disease development. The potential mechanisms of molecular mimicry between plant viruses and human disease should be further explored.

A 21-35 kDa Mixed Protein Component from Helicobacter pylori Activates Mast Cells Effectively in Chronic Spontaneous Urticaria.

PubMed

Tan, Ran-Jing; Sun, He-Qiang; Zhang, Wei; Yuan, Han-Mei; Li, Bin; Yan, Hong-Tao; Lan, Chun-Hui; Yang, Jun; Zhao, Zhuo; Wu, Jin-Jin; Wu, Chao

2016-12-01

Helicobacter pylori (H. pylori) seem to involve in the etiology of chronic spontaneous urticaria (CSU). But studies of the pathogenic mechanism are very little. In this study, we detected the serum-specific anti-H. pylori IgG and IgE antibodies in 211 CSU and 137 normal subjects by enzyme-linked immunosorbent assay (ELISA), evaluated the direct activation effects of H. pylori preparations and its protein components on human LAD 2 mast cell line in vitro, and analyzed the specific protein ingredients and functions of the most effective H. pylori mixed protein component using liquid chromatography-mass spectrometry and ELISA assay. In CSU patients, the positive rate of anti-H. pylori IgG positive rate was significantly higher than that in normal controls, and the anti-H. pylori IgE levels had no statistical difference between H. pylori-infected patients with and without CSU. Further studies suggested that H. pylori preparations can directly activate human LAD 2 mast cell line in a dose-dependent manner and its most powerful protein component was a mixture of 21-35 kDa proteins. Moreover, the 21-35 kDa mixed protein component mainly contained 23 kinds of proteins, which can stimulate the release of histamine, TNF-a, IL-3, IFN-γ, and LTB4 by LAD 2 cells in a dose-dependent or time-dependent manner. A 21-35 kDa mixed protein component should be regarded as the most promising pathogenic factor contributing to the CSU associated with H. pylori infection. © 2016 John Wiley & Sons Ltd.

Relative stabilities of IgG1 and IgG4 Fab domains: Influence of the light–heavy interchain disulfide bond architecture

PubMed Central

Heads, James T; Adams, Ralph; D'Hooghe, Lena E; Page, Matt J T; Humphreys, David P; Popplewell, Andrew G; Lawson, Alastair D; Henry, Alistair J

2012-01-01

The stability of therapeutic antibodies is a prime pharmaceutical concern. In this work we examined thermal stability differences between human IgG1 and IgG4 Fab domains containing the same variable regions using the thermofluor assay. It was found that the IgG1 Fab domain is up to 11°C more stable than the IgG4 Fab domain containing the same variable region. We investigated the cause of this difference with the aim of developing a molecule with the enhanced stability of the IgG1 Fab and the biological properties of an IgG4 Fc. We found that replacing the seven residues, which differ between IgG1 CH1 and IgG4 CH1 domains, while retaining the native IgG1 light-heavy interchain disulfide (L–H) bond, did not affect thermal stability. Introducing the IgG1 type L–H interchain disulfide bond (DSB) into the IgG4 Fab resulted in an increase in thermal stability to levels observed in the IgG1 Fab with the same variable region. Conversely, replacement of the IgG1 L–H interchain DSB with the IgG4 type L–H interchain DSB reduced the thermal stability. We utilized the increased stability of the IgG1 Fab and designed a hybrid antibody with an IgG1 CH1 linked to an IgG4 Fc via an IgG1 hinge. This construct has the expected biophysical properties of both the IgG4 Fc and IgG1 Fab domains and may therefore be a pharmaceutically relevant format. PMID:22761163

IgG Fc variant cross-reactivity between human and rhesus macaque FcγRs

PubMed Central

Boesch, Austin W.; Miles, Adam R.; Chan, Ying N.; Osei-Owusu, Nana Y.; Ackerman, Margaret E.

2017-01-01

ABSTRACT Non-human primate (NHP) studies are often an essential component of antibody development efforts before human trials. Because the efficacy or toxicity of candidate antibodies may depend on their interactions with Fcγ receptors (FcγR) and their resulting ability to induce FcγR-mediated effector functions such as antibody-dependent cell-meditated cytotoxicity and phagocytosis (ADCP), the evaluation of human IgG variants with modulated affinity toward human FcγR is becoming more prevalent in both infectious disease and oncology studies in NHP. Reliable translation of these results necessitates analysis of the cross-reactivity of these human Fc variants with NHP FcγR. We report evaluation of the binding affinities of a panel of human IgG subclasses, Fc amino acid point mutants and Fc glycosylation variants against the common allotypes of human and rhesus macaque FcγR by applying a high-throughput array-based surface plasmon resonance platform. The resulting data indicate that amino acid variation present in rhesus FcγRs can result in disrupted, matched, or even increased affinity of IgG Fc variants compared with human FcγR orthologs. These observations emphasize the importance of evaluating species cross-reactivity and developing an understanding of the potential limitations or suitability of representative in vitro and in vivo models before human clinical studies when either efficacy or toxicity may be associated with FcγR engagement. PMID:28055295

Urethral caruncle: a lesion related to IgG4-associated sclerosing disease?

PubMed

Williamson, Sean R; Scarpelli, Marina; Lopez-Beltran, Antonio; Montironi, Rodolfo; Conces, Miriam R; Cheng, Liang

2013-07-01

Urethral caruncle is a benign, polypoid urethral mass that occurs almost exclusively in postmenopausal women. Despite that these lesions are routinely managed with topical medications or excision, their pathogenesis is not well understood. We investigated the possibilities of autoimmune, viral and inflammatory myofibroblastic proliferations as possible aetiologies. In 38 patients with urethral caruncle, we utilised immunohistochemistry for immunoglobulin G (IgG) and IgG4 to assess for a potential autoimmune aetiology. Immunohistochemistry was performed in nine patients for Epstein-Barr virus, BK virus, human herpesvirus 8, human papillomavirus, adenovirus and anaplastic lymphoma kinase. Four patients (11%) showed infiltrates of ≥50 IgG4-positive plasma cells per high power field, of which all showed an IgG4 to IgG ratio greater than 40%. A statistically significant difference (p<0.01) was detected in the mean number of IgG4-positive cells (14.73 per high power field) compared with control benign urethral specimens (mean, 1.19). One patient with increased counts below this threshold had rheumatoid arthritis; none had documented autoimmune pancreatitis or other known manifestations of systemic IgG4-related sclerosing disease. All lesions showed negative reactions for the viral and inflammatory myofibroblastic markers. Urethral caruncle is a benign inflammatory and fibrous polypoid urethral mass of unclear aetiology. It appears unrelated to viral infection and lacks the abnormal expression of anaplastic lymphoma kinase protein, as seen in inflammatory myofibroblastic tumours. Increased numbers of IgG4-positive plasma cells in a subset of lesions raise the possibility that some cases may be related to the autoimmune phenomena of IgG4-associated disease.

Lymphocyte-dependent antibody-mediated cytotoxicity in Hashimoto thyroiditis

PubMed Central

Calder, Elizabeth A.; Penhale, W. J.; McLeman, Dena; Barnes, E. W.; Irvine, W. J.

1973-01-01

In the presence of normal human lymphocytes, decomplemented sera from twentynine out of thirty-nine patients with Hashimoto thyroiditis caused significant lysis of thyroglobulin-coated chicken red blood cells, as estimated by the release of 51Cr; the mean% specific 51Cr release being 14·1 ± 1·9 (SEM). Serum from twenty-one control subjects studied concurrently caused no significant lysis of thyroglobulin-coated chicken red blood cells; the mean% specific 51Cr release being −1·6±0·7 (SEM). The degree of cytotoxicity correlated with the titre of thyroglobulin antibodies in the serum, determined by tanned red cell haemagglutination. The active component in the Hashimoto serum was localized in the 19S fraction, was unaffected by pre-absorption with anti-human IgM serum, but was neutralized by pre-absorption with anti-human IgG serum. These findings suggest that the cytotoxic activity of serum from patients with Hashimoto thyroiditis is due to the presence of thyroglobulin antibody of the IgG class in the form of complexes, either alone or with antigen. It is postulated that non-specific lymphocytes may play an important role in the pathogenesis of Hashimoto thyroiditis, being activated by the presence in the gland of thyroglobulin antibody, either alone or in the form of complexes attached to thyroid cells. PMID:4740445

Aspartic acid incorporated monolithic columns for affinity glycoprotein purification.

PubMed

Armutcu, Canan; Bereli, Nilay; Bayram, Engin; Uzun, Lokman; Say, Rıdvan; Denizli, Adil

2014-02-01

Novel aspartic acid incorporated monolithic columns were prepared to efficiently affinity purify immunoglobulin G (IgG) from human plasma. The monolithic columns were synthesised in a stainless steel HPLC column (20 cm × 5 mm id) by in situ bulk polymerisation of N-methacryloyl-L-aspartic acid (MAAsp), a polymerisable derivative of L-aspartic acid, and 2-hydroxyethyl methacrylate (HEMA). Monolithic columns [poly(2-hydroxyethyl methacrylate-N-methacryloyl-L-aspartic acid) (PHEMAsp)] were characterised by swelling studies, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The monolithic columns were used for IgG adsorption/desorption from aqueous solutions and human plasma. The IgG adsorption depended on the buffer type, and the maximum IgG adsorption from aqueous solution in phosphate buffer was 0.085 mg/g at pH 6.0. The monolithic columns allowed for one-step IgG purification with a negligible capacity decrease after ten adsorption-desorption cycles. Copyright © 2013 Elsevier B.V. All rights reserved.

IgG4-Related Kidney Disease: Report of a Case Presenting as a Renal Mass.

PubMed

Bianchi, Daniele; Topazio, Luca; Gaziev, Gabriele; Iacovelli, Valerio; Bove, Pierluigi; Mauriello, Alessandro; Finazzi Agrò, Enrico

2017-01-01

IgG4-related disease (IgG4-RD) is a nosological entity defined as a chronic immune-mediated fibro-inflammatory condition characterized by a tendency to form tumefactive, tissue-destructive lesions or by organ failure. Urologic involvement in IgG4-RD has been described in some short series of patients and in isolated case reports, most often involving the kidneys in so-called IgG4-related kidney disease (IgG4-RKD). The disease can occasionally mimic malignancies and is at risk of being misdiagnosed due to its rarity. We report the case of a 56-year-old man presenting with a right renal mass suspected of being malignant. Laboratory tests showed normal creatinine levels, a high erythrocyte sedimentation rate, and high levels of C-reactive protein and microalbuminuria. The patient underwent radical right nephroureterectomy and histopathologic examination revealed features proving IgG4-RKD. He was therefore referred to immunologists. Typical clinical presentation of IgG4-RKD includes altered renal function with inconstant or no radiologic findings. Conversely, in the case we presented, a single nodule was detected upon imaging evaluation, thus mimicking malignancy. This raises the issue of a proper differential diagnosis. A multidisciplinary approach can be useful, although in clinical practice the selection of patients suspected of having IgG4-RKD is critical in the cases presenting with a renal mass that mimics malignancy.

Anti-EBOV GP IgGs Lacking α1-3-Galactose and Neu5Gc Prolong Survival and Decrease Blood Viral Load in EBOV-Infected Guinea Pigs

PubMed Central

Reynard, Olivier; Jacquot, Frédéric; Evanno, Gwénaëlle; Mai, Hoa Le; Martinet, Bernard; Duvaux, Odile; Bach, Jean-Marie; Conchon, Sophie; Judor, Jean-Paul; Perota, Andrea; Lagutina, Irina; Duchi, Roberto; Lazzari, Giovanna; Le Berre, Ludmilla; Perreault, Hélène; Lheriteau, Elsa; Raoul, Hervé; Volchkov, Viktor; Galli, Cesare; Soulillou, Jean-Paul

2016-01-01

Polyclonal xenogenic IgGs, although having been used in the prevention and cure of severe infectious diseases, are highly immunogenic, which may restrict their usage in new applications such as Ebola hemorrhagic fever. IgG glycans display powerful xenogeneic antigens in humans, for example α1–3 Galactose and the glycolyl form of neuraminic acid Neu5Gc, and IgGs deprived of these key sugar epitopes may represent an advantage for passive immunotherapy. In this paper, we explored whether low immunogenicity IgGs had a protective effect on a guinea pig model of Ebola virus (EBOV) infection. For this purpose, a double knock-out pig lacking α1–3 Galactose and Neu5Gc was immunized against virus-like particles displaying surface EBOV glycoprotein GP. Following purification from serum, hyper-immune polyclonal IgGs were obtained, exhibiting an anti-EBOV GP titer of 1:100,000 and a virus neutralizing titer of 1:100. Guinea pigs were injected intramuscularly with purified IgGs on day 0 and day 3 post-EBOV infection. Compared to control animals treated with IgGs from non-immunized double KO pigs, the anti-EBOV IgGs-treated animals exhibited a significantly prolonged survival and a decreased virus load in blood on day 3. The data obtained indicated that IgGs lacking α1–3 Galactose and Neu5Gc, two highly immunogenic epitopes in humans, have a protective effect upon EBOV infection. PMID:27280712

Riedel's thyroiditis association with IgG4-related disease.

PubMed

Stan, Marius N; Sonawane, Vikram; Sebo, Thomas J; Thapa, Prabin; Bahn, Rebecca S

2017-03-01

IgG4-positive (+) plasma cells have been reported in both Riedel's thyroiditis (RT) and Hashimoto's thyroiditis (HT). These cells are the hallmark of IgG4-related disease (IgG4-RD). We sought to determine whether RT is part of IgG4-RD spectrum. This was a case-control study performed at a tertiary medical centre. We included RT cases from the period 1958 to 2008 that had sufficient paraffin-embedded tissue for IgG4 immunostaining. Controls were patients with HT, age and gender matched, with similar pathology criteria. The main outcome measures were the intensity of the IgG4 staining and the clinical and histological correlates with IgG4-RD. Six pairs of RT and HT were analysed. The mean age was 44·7 years. In both groups, 5/6 cases had positive IgG4 staining. The mean number of IgG4 + cells/ HPF, normalized to the degree of inflammation, was 3·2 ± 3·0 SD (RT) vs 0·9 ± 0·7 (HT), P = 0·15, for fibrotic areas and 2·1 ± 2·3 SD vs 1·0 ± 0·8 (P = 0·39) for areas with lymphoid aggregates. We found the number of IgG4 +  cells in RT to be inversely correlated with the duration of disease (P = 0·046). Three RT cases had associated comorbidities from the IgG4-RD spectrum while none of the HT cases had such conditions. Riedel's thyroiditis is a component of IgG4-RD with the density of the IgG4 +  lymphocytic infiltrate being time dependent. In this small study, we did not identify differences in IgG4 infiltration between RT and HT, minimizing the utility of this marker in RT diagnosis. © 2016 John Wiley & Sons Ltd.

The vagina of women infected with Trichomonas vaginalis has numerous proteinases and antibody to trichomonad proteinases.

PubMed

Alderete, J F; Newton, E; Dennis, C; Neale, K A

1991-12-01

Patients with trichomoniasis have serum antibody to numerous T. vaginalis cysteine proteinases, indicating that the proteinases are expressed in vivo. It was important, therefore, to examine for the presence of soluble trichomonad proteinases and/or antibody to the proteinases in the vagina of infected women. Vaginal washes (VWs) from 20 women were examined for the presence of proteinases by electrophoresis using acrylamide co-polymerised with gelatin as the indicator system. Antibody to proteinases in VWs was detected by an immunoprecipitation assay involving protein A-bearing Staphylococcus aureus first coated with anti-human immunoglobulin G (IgG) antibody, which was then added to VWs. For VWs having soluble proteinases, the bacteria were used to determine whether immune complexes between antibody and proteinases were present. VWs without soluble proteinases were incubated with the anti-human IgG treated bacteria before adding to detergent extracts of T. vaginalis. Individual isolates from the patients examined in this study were also analysed by one- and two-dimensional electrophoresis for their proteinase content. Finally, VWs were from patients without any history of other sexually transmitted diseases (STDs) as well as from individuals having numerous other STDs, including yeast, group B streptococcus, chlamydia, and syphilis. Approximately one-third of patients had soluble proteinases in the VWs; the remaining two-thirds (70%) of patients and normal women had no detectable proteinases in VWs. Half of the patients without soluble proteinases had IgG which, when bound to S. aureus, immunoprecipitated many proteinases from a detergent extract of T. vaginalis. All soluble proteinases and those precipitated from trichomonal extracts were inhibited by inhibitors of cysteine proteinases. Finally, patients having trichomoniasis in addition to numerous other STD agents, including yeast, group B streptococcus, chlamydia, and syphilis did not have soluble proteinases in VWs. Equally noteworthy, some patients with soluble proteinases in VWs did not have other detectable STD agents. Proteinases were detected in the vagina of some patients with trichomoniasis, and in most cases the proteinases were complexed with IgG, which was precipitated by S. aureus. Patients without soluble proteinases in VWs also had antibody specifically to trichomonad proteinases, again demonstrating both the expression and immunogenic nature of the proteinases in vivo. The absence of soluble proteinases in normal women and in patients having other STD agents as well as the presence of proteinases in VWs of patients without other detectable STD pathogens reinforced the idea that the proteinases were of T. vaginalis parasite origin. The findings of this study indicate that proteinases may be important to the T. vaginalis-host interrelationship.

High Expression of Galectin-3 in Patients with IgG4-Related Disease: A Proteomic Approach.

PubMed

Salah, Adeeb; Yoshifuji, Hajime; Ito, Shinji; Kitagori, Koji; Kiso, Kaori; Yamada, Norishige; Nakajima, Toshiki; Haga, Hironori; Tsuruyama, Tatsuaki; Miyagawa-Hayashino, Aya

2017-01-01

Immunoglobulin G4-related disease (IgG4-RD) is a multiorgan condition manifesting itself in different forms. This study aimed to investigate protein expression profiles and to find the possible biomarker for IgG4-RD by liquid chromatography mass spectrometry (LC-MS) using tissue sections in IgG4-RD patients. Protein expression profiles in five IgG4-related pancreatitis and three normal pancreatic samples were compared using LC-MS and were validated by quantitative real-time PCR (qRT-PCR), immunoblotting, and immunohistochemistry. ELISA was employed in the serum of 20 patients with systemic IgG4-RD before and during steroid treatment. LC-MS indicated that the levels of 17 proteins were significantly higher and 12 others were significantly lower in IgG4-related pancreatitis patients compared to controls. Among these proteins, galectin-3 levels were 13-fold higher in IgG4-related pancreatitis ( P < 0.01). These results were confirmed by immunoblotting and qRT-PCR. The average number of galectin-3 + cells in various organs of IgG4-RD patients, including salivary glands, lungs, and lymph nodes, was higher than in controls. Galectin-3 was detectable in macrophages, dendritic cells, and stromal myofibroblast-like cells, but not in lymphocytes by immunofluorescence staining. Serum galectin-3 levels were higher in patients with IgG4-RD compared with healthy donors and remained high during steroid therapy. Galectin-3 was overexpressed in IgG4-RD and the levels were indirectly related to clinical activity.

High Expression of Galectin-3 in Patients with IgG4-Related Disease: A Proteomic Approach

PubMed Central

Salah, Adeeb; Yoshifuji, Hajime; Ito, Shinji; Kitagori, Koji; Kiso, Kaori; Yamada, Norishige; Nakajima, Toshiki; Haga, Hironori; Tsuruyama, Tatsuaki

2017-01-01

Objectives Immunoglobulin G4-related disease (IgG4-RD) is a multiorgan condition manifesting itself in different forms. This study aimed to investigate protein expression profiles and to find the possible biomarker for IgG4-RD by liquid chromatography mass spectrometry (LC-MS) using tissue sections in IgG4-RD patients. Methods Protein expression profiles in five IgG4-related pancreatitis and three normal pancreatic samples were compared using LC-MS and were validated by quantitative real-time PCR (qRT-PCR), immunoblotting, and immunohistochemistry. ELISA was employed in the serum of 20 patients with systemic IgG4-RD before and during steroid treatment. Results LC-MS indicated that the levels of 17 proteins were significantly higher and 12 others were significantly lower in IgG4-related pancreatitis patients compared to controls. Among these proteins, galectin-3 levels were 13-fold higher in IgG4-related pancreatitis (P < 0.01). These results were confirmed by immunoblotting and qRT-PCR. The average number of galectin-3 + cells in various organs of IgG4-RD patients, including salivary glands, lungs, and lymph nodes, was higher than in controls. Galectin-3 was detectable in macrophages, dendritic cells, and stromal myofibroblast-like cells, but not in lymphocytes by immunofluorescence staining. Serum galectin-3 levels were higher in patients with IgG4-RD compared with healthy donors and remained high during steroid therapy. Conclusion Galectin-3 was overexpressed in IgG4-RD and the levels were indirectly related to clinical activity. PMID:28593065

Human autoantibodies against a desmosomal core protein in pemphigus foliaceus

PubMed Central

1984-01-01

Pemphigus foliaceus (PF) is a human autoimmune disease in which antibodies are directed against the cell surface of epidermal cells with resultant blister formation. The histopathology of these blisters indicates that cells have detached from each other, and electron microscopy of early blisters shows diminished numbers, to complete loss, of desmosomes as well as abnormalities of the tonofilament- desmosome complex. In this study we demonstrate that autoantibodies from certain PF patients bind to a desmosomal core glycoprotein called desmoglein (DG) I. Proteins in extracts of normal human epidermis were separated by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis (PAGE), then transferred to nitrocellulose or 2- aminophenylthioether paper for immunoperoxidase staining. Results of these immunoblots indicated that sera from 6 of 13 PF patients specifically and intensely stained an approximately 160,000 mol wt polypeptide, "PF antigen". Such staining was not seen with normal human sera or sera from patients with pemphigus vulgaris or bullous pemphigoid, two autoimmune blistering skin diseases that are clinically, histologically, and immunochemically distinct from PF. However, rabbit antiserum directed against DGI, that was isolated from bovine muzzle desmosomes, stained a polypeptide band which co-migrated with PF antigen. Furthermore, when proteins from extracts of normal human epidermis were electrophoresed in two dimensions (isoelectric focusing, then SDS-PAGE) before transfer to nitrocellulose for immunoperoxidase staining, PF antibodies and antibodies to DGI stained identical spots. Finally, PF sera as well as PF IgG that was affinity purified with PF antigen from normal human epidermis, both selectively bound to DGI extracted from bovine muzzle desmosomes. These studies demonstrate that the human autoantibodies from certain patients with PF, a disease of epidermal cell adhesion, are directed against a desmosomal core protein. PMID:6491602

Prevalence estimation of tick-borne encephalitis virus (TBEV) antibodies in dogs from Finland using novel dog anti-TBEV IgG MAb-capture and IgG immunofluorescence assays based on recombinant TBEV subviral particles.

PubMed

Levanov, Lev; Vera, Cristina Pérez; Vapalahti, Olli

2016-07-01

Tick-borne encephalitis (TBE) is one of the most dangerous human neurological infections occurring in Europe and Northern parts of Asia with thousands of cases and millions vaccinated against it. The risk of TBE might be assessed through analyses of the samples taken from wildlife or from animals which are in close contact with humans. Dogs have been shown to be a good sentinel species for these studies. Serological assays for diagnosis of TBE in dogs are mainly based on purified and inactivated TBEV antigens. Here we describe novel dog anti-TBEV IgG monoclonal antibody (MAb)-capture assay which is based on TBEV prME subviral particles expressed in mammalian cells from Semliki Forest virus (SFV) replicon as well as IgG immunofluorescence assay (IFA) which is based on Vero E6 cells transfected with the same SFV replicon. We further demonstrate their use in a small-scale TBEV seroprevalence study of dogs representing different regions of Finland. Altogether, 148 dog serum samples were tested by novel assays and results were compared to those obtained with a commercial IgG enzyme immunoassay (EIA), hemagglutination inhibition test and IgG IFA with TBEV infected cells. Compared to reference tests, the sensitivities of the developed assays were 90-100% and the specificities of the two assays were 100%. Analysis of the dog serum samples showed a seroprevalence of 40% on Åland Islands and 6% on Southwestern archipelago of Finland. In conclusion, a specific and sensitive EIA and IFA for the detection of IgG antibodies in canine sera were developed. Based on these assays the seroprevalence of IgG antibodies in dogs from different regions of Finland was assessed and was shown to parallel the known human disease burden as the Southwestern archipelago and Åland Islands in particular had considerable dog TBEV antibody prevalence and represent areas with high risk of TBE for humans. Copyright © 2016 Elsevier GmbH. All rights reserved.

In vitro removal of human IgG autoantibodies by affinity filtration using immobilized L-histidine onto PEVA hollow fiber membranes.

PubMed

Ventura, R C; Zollner, R L; Legallais, C; Vijayalakshmi, M; Bueno, S M

2001-01-01

Histidine was immobilized onto PEVA membrane to obtain an affinity support for human IgG removal from serum with a view to clinical apheresis for the treatment of autoimmune diseases. These membranes were able to remove in vitro several autoantibodies from the serum of SLE patients.

Immunoglobulin G (IgG) Subclass Distribution and IgG1 Avidity of Antibodies in Human Immunodeficiency Virus-Infected Individuals after Revaccination with Tetanus Toxoid

PubMed Central

Kroon, F. P.; van Tol, M. J. D.; Jol-van der Zijde, C. M.; van Furth, R.; van Dissel, J. T.

1999-01-01

In human immunodeficiency virus (HIV)-infected individuals the amount of antibodies formed after vaccination with T-cell-dependent recall antigens such as tetanus toxoid is proportional to the peripheral blood CD4+ T-lymphocyte counts. To investigate whether the immunoglobulin G (IgG) subclass distribution and avidity of the antibodies produced after vaccination are affected as well, we gave 13 HIV-infected adults with low CD4+ T-lymphocyte counts (<200 × 106/liter; group I), 11 HIV-infected adults with intermediate CD4+ T-lymphocyte counts (≥200 × 106/liter; group II), and 5 healthy controls booster immunizations with tetanus toxoid. The prevaccination antibody concentrations against tetanus toxoid were similar in the HIV-infected and healthy adults. After vaccination the total IgG and the IgG1 anti-tetanus toxoid antibody concentrations were significantly lower in group I than in group II and the controls. The avidity of the IgG1 anti-tetanus toxoid antibodies formed by HIV-infected adults was within the range for healthy controls, irrespective of their CD4+ T-lymphocyte counts. PMID:10225835

Altered glycosylation of complexed native IgG molecules is associated with disease activity of systemic lupus erythematosus.

PubMed

Sjöwall, C; Zapf, J; von Löhneysen, S; Magorivska, I; Biermann, M; Janko, C; Winkler, S; Bilyy, R; Schett, G; Herrmann, M; Muñoz, L E

2015-05-01

In addition to the redundancy of the receptors for the Fc portion of immunoglobulins, glycans result in potential ligands for a plethora of lectin receptors found in immune effector cells. Here we analysed the exposure of glycans containing fucosyl residues and the fucosylated tri-mannose N-type core by complexed native IgG in longitudinal serum samples of well-characterized patients with systemic lupus erythematosus. Consecutive serum samples of a cohort of 15 patients with systemic lupus erythematosus during periods of increased disease activity and remission were analysed. All patients fulfilled the 1982 American College of Rheumatology classification criteria. Sera of 15 sex- and age-matched normal healthy blood donors served as controls. The levels and type of glycosylation of complexed random IgG was measured with lectin enzyme-immunosorbent assays. After specifically gathering IgG complexes from sera, biotinylated lectins Aleuria aurantia lectin and Lens culinaris agglutinin were employed to detect IgG-associated fucosyl residues and the fucosylated tri-mannose N-glycan core, respectively. In sandwich-ELISAs, IgG-associated IgM, IgA, C1q, C3c and C-reactive protein (CRP) were detected as candidates for IgG immune complex constituents. We studied associations of the glycan of complexed IgG and disease activity according to the physician's global assessment of disease activity and the systemic lupus erythematosus disease activity index 2000 documented at the moment of blood taking. Our results showed significantly higher levels of Aleuria aurantia lectin and Lens culinaris agglutinin binding sites exposed on IgG complexes of patients with systemic lupus erythematosus than on those of normal healthy blood donors. Disease activity in systemic lupus erythematosus correlated with higher exposure of Aleuria aurantia lectin-reactive fucosyl residues by immobilized IgG complexes. Top levels of Aleuria aurantia lectin-reactivity were found in samples taken during the highest activity of systemic lupus erythematosus. Our results show that native circulating IgG complexes from active systemic lupus erythematosus patients expose fucosyl residues and their glycan core is accessible to soluble lectins. Two putative mechanisms may contribute to the increased exposure of these glycans: (1) the canonical N-glycosylation site of the IgG-CH2 domain; (2) an IgG binding non-IgG molecule, like complement or C-reactive protein. In both cases the complexed IgG may be alternatively targeted to lectin receptors of effector cells, e.g. dendritic cells. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Inverse Gaussian gamma distribution model for turbulence-induced fading in free-space optical communication.

PubMed

Cheng, Mingjian; Guo, Ya; Li, Jiangting; Zheng, Xiaotong; Guo, Lixin

2018-04-20

We introduce an alternative distribution to the gamma-gamma (GG) distribution, called inverse Gaussian gamma (IGG) distribution, which can efficiently describe moderate-to-strong irradiance fluctuations. The proposed stochastic model is based on a modulation process between small- and large-scale irradiance fluctuations, which are modeled by gamma and inverse Gaussian distributions, respectively. The model parameters of the IGG distribution are directly related to atmospheric parameters. The accuracy of the fit among the IGG, log-normal, and GG distributions with the experimental probability density functions in moderate-to-strong turbulence are compared, and results indicate that the newly proposed IGG model provides an excellent fit to the experimental data. As the receiving diameter is comparable with the atmospheric coherence radius, the proposed IGG model can reproduce the shape of the experimental data, whereas the GG and LN models fail to match the experimental data. The fundamental channel statistics of a free-space optical communication system are also investigated in an IGG-distributed turbulent atmosphere, and a closed-form expression for the outage probability of the system is derived with Meijer's G-function.

Suppression of in vivo polyclonal IgE responses by monoclonal antibody to the lymphokine B-cell stimulatory factor 1.

PubMed Central

Finkelman, F D; Katona, I M; Urban, J F; Snapper, C M; Ohara, J; Paul, W E

1986-01-01

The lymphokine B-cell stimulatory factor 1 (BSF-1) has been shown to greatly enhance the differentiation of lipopolysaccharide-activated B cells into IgG1- and IgE-secreting cells in vitro. To determine whether in vivo IgG1 and IgE antibody responses are BSF-1 dependent, the ability of a monoclonal rat IgG1 anti-BSF-1 antibody, 11B11, to affect polyclonal IgG1 and IgE production in mice infected with the nematode parasite Nippostrongylus brasiliensis or injected with a purified goat antibody to mouse IgD was studied. 11B11-containing ascites fluid or purified 11B11 strongly inhibited IgE production in both systems but did not affect IgG1 production, while control ascites or normal rat IgG1 had no IgE-inhibitory activity. These results indicate an important physiologic role for BSF-1 in the generation of IgE antibody responses and suggest means for limiting the production of antibodies responsible for allergic reactions without inhibiting protective antibody responses. PMID:3491987

Evaluation of human cystic echinococcosis before and after surgery and chemotherapy by demonstration of antibodies in serum.

PubMed

Tenguria, Rajesh Kumar; Naik, Mohd Irfan

2014-01-01

Human cystic echinococcosis (CE), caused by Echinococcus granulosus, is one of the most important and widespread parasitic zoonoses. As one of the problems that can be encountered after treating CE patients is the risk of postsurgical relapses or treatment failure, a long-term clinical and serological follow-up is required to evaluate the success and failure of therapy. Therefore, the aim of the present study was to identify the best diagnostic and prognostic ELISA markers in patients with CE. The cohort comprised 50 patients with symptomatic CE treated with antihelminthic drugs and surgery, who were followed up clinically and radiologically for a mean of 6 years (range 4-8 years). The results clearly indicate that the hydatid specific antibodies of IgE, IgG1 and IgG4 are the most important antibodies for the serological diagnosis of cystic echinococcosis during the active stage of the disease. None of the serum samples from healthy controls gave a non-specific reaction with IgE, IgG1 or IgG4, and a considerably reduced cross-reaction was observed with these antibodies. During post-operative follow-up, the IgM, IgE, IgG1, IgG2 and IgG4 antibody response provided the best correlate of disease activity. The detection of total IgG and IgG3 subclass antibody response for the assessment of post-treatment disease activity among CE patients was insensitive. All patients responded to treatment except 2 women (32 and 36 years old), in whom multiple cysts (12 and 7 cysts) were detected in the liver and lung two years after the first operation. Hence, it can be concluded that the CE-specific antibodies of IgE, IgG1 and IgG4 are the best immunological markers for diagnosis and prognosis of CE patients.

Complexes prepared from protein A and human serum, IgG, or Fc gamma fragments: characterization by immunochemical analysis of ultracentrifugation fractions and studies on their interconversion.

PubMed

Langone, J J; Das, C; Mainwaring, R; Shearer, W T

1985-01-01

Protein A of Staphylococcus aureus is an Fc receptor for IgG that has been used as a therapeutic reagent to treat cancer in humans and experimental animals. We used ultracentrifugation combined with analysis of isolated fractions by radioimmunoprecipitation and competitive radioimmunoassay with chicken antibodies that bind free protein A or protein A in complexes but do bind free immunoglobulin reagents to localize and characterize the types of complexes formed with different molar ratios of 125I-protein A and human 131I-IgG alone or in serum, and 131I-Fc gamma fragments. This approach offers a distinct advantage over direct counting of radioactivity in the fractions because resolution of complexes and free reagents is much improved. With excess 131I-IgG or 131I-Fc, all the 125I-protein A is present only in complexes that contained 4 molecules of immunoglobulin reagent and 2 molecules of protein A (4:2 complexes), whereas with excess 125I-protein A the stoichiometry of the complexes was 1:1. We have also shown the preformed 4:2 and 1:1 complexes will interconvert in the presence of added excess protein A or IgG, respectively, and that fresh IgG will exchange with IgG or Fc gamma in preformed complexes. Because protein A has been found to elute from an immobilized reagent used in serotherapy of human cancer and is present in a large excess of IgG, the 4:2 complexes may play an active role in the tumoricidal or toxic reactions observed.

Quantitative glycan profiling of normal human plasma derived immunoglobulin and its fragments Fab and Fc.

PubMed

Anumula, Kalyan Rao

2012-08-31

Typical clinical grade human IgG (intravenous immunoglobulin, IVIG), used for carbohydrate analysis, is derived from thousands of healthy donors. Quantitative high-resolution glycan profiles of IgG and its Fc-Fab fragments are presented here. Glycan profiles were established following digestions with Fc specific endoglycosidase S and generic PNGase F under denaturing and non-denaturing (native) conditions. The native PNGase F glycan profile of IgG was similar (but not identical) to that of Endo S. Endo S profiles did not contain the glycans with bisecting GlcNAc. PNGase F glycan profiles were the same for Fc fragments that were isolated from pepsin and Ide S protease digests. Both isolated Fab fragments and the previously deglycosylated IVIG (native conditions) yielded the same glycan profile. Glycan profiles were established using high resolution HPLC with 2-aminobenzoic acid (2AA) labeling. An accurate determination of sialylation levels can be made by this method. Carbohydrate content in Fc and Fab was determined using an internal standard and corrected for both protein and glycan recoveries. Fab portion contained about 14% of the total carbohydrate which translates to 2.3 sugar chains per mol in IVIG where 2 chains are located in the CH2 domain of the Fc. Fc glycans consisted of neutral (N) 84.5%; mono-sialylated (S1) 15% and di-sialylated (S2) 0.5%. In contrast, Fab contained N, 21%; S1, 43% and S2, 36%. The distribution of bisecting N-acetylglucosamine and fucose was found to be very different in various glycans (N, S1 and S2) found in Fab and Fc. Total IgG glycan profile (Fab plus Fc) contained N, 78.5%; S1, 17% and S2, 4.5%. Percent distribution of glycans G0, G1 and G2 (with 0, 1 and 2 two galactoses) was 26, 49 and 25 respectively within the 78% of the neutral glycans. Glycan profiles were nearly the same for various clinical grade IVIG preparations from various manufacturers. A fast HPLC profiling method was developed for the separation and quantitation of IgG glycans (neutral (G0, G1, and G2), mono- and di-sialylated) using simple procedures. The method should prove useful for monitoring glycan changes in clinical settings. Copyright © 2012 Elsevier B.V. All rights reserved.

Human IgG Antibody Response to Aedes Nterm-34kDa Salivary Peptide, an Epidemiological Tool to Assess Vector Control in Chikungunya and Dengue Transmission Area

PubMed Central

Elanga Ndille, Emmanuel; Doucoure, Souleymane; Poinsignon, Anne; Mouchet, François; Cornelie, Sylvie; D’Ortenzio, Eric; DeHecq, Jean Sébastien; Remoue, Franck

2016-01-01

Background Arboviral diseases are an important public health concerns. Vector control remains the sole strategy to fight against these diseases. Because of the important limits of methods currently used to assess human exposure to Aedes mosquito bites, much effort is being devoted to develop new indicators. Recent studies have reported that human antibody (Ab) responses to Aedes aegypti Nterm-34kDa salivary peptide represent a promising biomarker tool to evaluate the human-Aedes contact. The present study aims investigate whether such biomarker could be used for assessing the efficacy of vector control against Aedes. Methodology/Principal findings Specific human IgG response to the Nterm-34kDa peptide was assessed from 102 individuals living in urban area of Saint-Denis at La Reunion Island, Indian Ocean, before and after the implementation of vector control against Aedes mosquitoes. IgG response decreased after 2 weeks (P < 0.0001), and remained low for 4 weeks post-intervention (P = 0.0002). The specific IgG decrease was associated with the decline of Aedes mosquito density, as estimated by entomological parameters and closely correlated to vector control implementation and was not associated with the use of individual protection, daily commuting outside of the house, sex and age. Our findings indicate a probable short-term decrease of human exposure to Aedes bites just after vector control implementation. Conclusion/Significance Results provided in the present study indicate that IgG Ab response to Aedes aegypti Nterm-34kDa salivary peptide could be a relevant short-time indicator for evaluating the efficacy of vector control interventions against Aedes species. PMID:27906987

Human IgG Antibody Response to Aedes Nterm-34kDa Salivary Peptide, an Epidemiological Tool to Assess Vector Control in Chikungunya and Dengue Transmission Area.

PubMed

Elanga Ndille, Emmanuel; Doucoure, Souleymane; Poinsignon, Anne; Mouchet, François; Cornelie, Sylvie; D'Ortenzio, Eric; DeHecq, Jean Sébastien; Remoue, Franck

2016-12-01

Arboviral diseases are an important public health concerns. Vector control remains the sole strategy to fight against these diseases. Because of the important limits of methods currently used to assess human exposure to Aedes mosquito bites, much effort is being devoted to develop new indicators. Recent studies have reported that human antibody (Ab) responses to Aedes aegypti Nterm-34kDa salivary peptide represent a promising biomarker tool to evaluate the human-Aedes contact. The present study aims investigate whether such biomarker could be used for assessing the efficacy of vector control against Aedes. Specific human IgG response to the Nterm-34kDa peptide was assessed from 102 individuals living in urban area of Saint-Denis at La Reunion Island, Indian Ocean, before and after the implementation of vector control against Aedes mosquitoes. IgG response decreased after 2 weeks (P < 0.0001), and remained low for 4 weeks post-intervention (P = 0.0002). The specific IgG decrease was associated with the decline of Aedes mosquito density, as estimated by entomological parameters and closely correlated to vector control implementation and was not associated with the use of individual protection, daily commuting outside of the house, sex and age. Our findings indicate a probable short-term decrease of human exposure to Aedes bites just after vector control implementation. Results provided in the present study indicate that IgG Ab response to Aedes aegypti Nterm-34kDa salivary peptide could be a relevant short-time indicator for evaluating the efficacy of vector control interventions against Aedes species.

Equine sperm-bound antisperm antibodies are associated with poor semen quality.

PubMed

Ferrer, M S; Miller, L M J

2018-06-01

Antisperm antibodies (ASAs) have been associated with infertility in stallions. The objectives of this study were to investigate the frequency of ASA-positive semen samples in satisfactory and non-satisfactory breeder stallions, the association between ASA binding and semen quality, and factors that may affect the diagnosis. Breeding soundness examinations were performed in 21 stallions and the percentage of IgG- and IgA-bound spermatozoa was evaluated using flow cytometry. Median IgG and IgA binding did not differ between the first and second ejaculates. The percentage of IgA-bound spermatozoa was higher in non-satisfactory (n = 10) than satisfactory breeder stallions (n = 11). However, IgG binding or frequency of IgG-positive ejaculates did not differ with stallion classification. The IgG-positive stallions had significantly lower total sperm motility, concentration and total numbers than IgG-negative stallions in the first ejaculate, and lower sperm concentration in the second ejaculate. The IgA-positive stallions had lower total sperm motility, normal spermatozoa and total numbers than IgA-negative stallions in the first ejaculate, and lower total sperm motility, normal spermatozoa and total numbers in the second ejaculate. While IgG binding did not differ with season, IgA binding was higher in the non-breeding season (n = 6 stallions) than the breeding season (n = 15 stallions) in the first ejaculate. Stallion age did not differ with ASA classification. In conclusion, IgG binding was highly prevalent in both groups of stallions, while IgA binding was higher and more prevalent in non-satisfactory breeders. Both isotypes were associated with poor semen quality. Season and sexual rest had an effect on IgA but not IgG binding. Copyright © 2018 Elsevier Inc. All rights reserved.

L-proline-stabilized human IgG: Privigen® 10% for intravenous use and Hizentra® 20% for subcutaneous use.

PubMed

Berger, Melvin

2011-02-01

Liquid IgG preparations are preferred over lyophilized preparations because reconstitution is not required. Formation of dimers and aggregates in liquid preparations increases adverse effects and limits the shelf life of most liquid IgG products. Improved understanding of the binding interactions in IgG dimers and aggregates led to the selection of L-proline at pH 4.8 as an excipient that would minimize their formation. CSL Behring has developed the L-proline-stabilized products Privigen®, a 10% IgG solution for intravenous use; and Hizentra®, a 20% solution for subcutaneous use. The former has the longest shelf life of any liquid IgG in the USA--36 months, and the latter is the most concentrated IgG available. These improvements, which translate into improved convenience for pharmacies and patients, were achieved with no compromise in safety, efficacy or tolerability of the products.

An enzyme-linked immunosorbent assay for the quantification of serum platelet-bindable IgG.

PubMed

Howe, S E; Lynch, D M; Lynch, J M

1984-01-01

An enzyme-linked immunosorbent assay (ELISA) using F(ab')2 peroxidase-labeled antihuman immunoglobulin and o-phenylenediamine dihydrochloride (OPD) as a substrate was developed to measure serum platelet bindable IgG (S-PBIgG). The assay was made quantitative by standardizing the number of normal "target" platelets bound to microtiter plate wells, and by incorporating quantitated IgG standards with each microtiter plate tested to prepare a standard calibration curve. By this method, S-PBIgG for normal individuals was 3.4 +/- 1.6 fg per platelet (mean +/- 1 SD; n = 40). Increased S-PBIgG levels were detected in 36 of 40 patients with clinical autoimmune thrombocytopenia (ATP), ranging from 7.0 to 85 fg per platelet. Normal S-PBIgG levels were found in 34 of 40 patients with nonimmune thrombocytopenia. This method showed a sensitivity of 90 percent, specificity of 85 percent, and in the sample population studied, a positive predictive value of 0.86 and a negative predictive value of 0.90. This assay is highly reproducible (coefficient of variation was 6.8%) and appears useful in the evaluation of patients with suspected immune-mediated thrombocytopenia.

Effect of alterations in glomerular charge on deposition of cationic and anionic antibodies to fixed glomerular antigens in the rat.

PubMed

Adler, S; Baker, P; Pritzl, P; Couser, W G

1985-07-01

Reduction of the negative charge of the glomerular capillary wall alters its charge- and size-selective properties. To investigate the effect of alteration in glomerular charge properties on antibody localization, we prepared cationic and anionic fractions of antibodies to subepithelial and glomerular basement membrane (GBM) antigens, and compared their deposition in normal rats and rats treated with protamine sulfate or aminonucleoside of puromycin to reduce capillary wall charge. IgG antibodies were eluted from kidneys of rats with active Heymann's nephritis (AICN), passive Heymann's nephritis (PHN), or anti-GBM nephritis (NTN), separated into cationic and anionic fractions, and radiolabeled with iodine 125 or iodine 131. Relative antibody content of each fraction was determined by incubation with an excess of glomerular antigen. Varying amounts of cationic and anionic IgG eluted from kidneys of rats with AICN or PHN were injected into 24 normal or protamine sulfate-treated rats. Glomerular binding of all antibodies was highly correlated with IgG delivery to the kidney. The ratio of cationic to anionic antibody deposited in the glomeruli of normal rats after 4 hours was 1.08 +/- 0.07 for AICN eluate and 0.37 +/- 0.04 for PHN eluate. The ratios were not significantly different in animals pretreated with protamine sulfate (1.15 +/- 0.06 and 0.44 +/- 0.06, respectively; P greater than 0.05). Varying amounts of cationic and anionic IgG eluted from kidneys of rats with NTN were injected into 10 normal rats and four rats treated with aminonucleoside of puromycin. Glomerular binding of antibody was again highly correlated with IgG delivery to the kidney. The ratio of cationic to anionic antibody deposited in the glomeruli of normal rats after 1 hour was 1.03 +/- 0.06, and was not significantly altered in rats treated with aminonucleoside of puromycin (1.05 +/- 0.03, P greater than 0.5). Proteinuria in PHN rats was also unaffected by treatment with protamine sulfate for 5 days (controls: 68 +/- 21 mg/day; protamine sulfate-treated: 65 +/- 14 mg/day; n = 25, P greater than 0.08). These results demonstrate that treatment to reduce glomerular polyanion does not significantly alter the ratio of cationic to anionic antibodies to fixed glomerular antigens that deposit in the glomerulus, or reduce proteinuria caused by deposition of antibody to a fixed subepithelial antigen.

Circulating antibodies to Saccharomyces cerevisiae (bakers'/brewers' yeast) in gastrointestinal disease.

PubMed Central

Darroch, C J; Barnes, R M; Dawson, J

1999-01-01

AIM: To measure circulating antibodies to yeast organisms that could be used to characterise the yeast specific immune response in gastrointestinal disease. METHODS: A quantitative, isotype specific enzyme linked immunosorbent assay was developed to measure circulating antibodies to an aqueous extract of Saccharomyces cerevisiae (sacc). Comparisons of specific antibody concentrations were made between 224 healthy controls and 51 patients with Crohn's disease, 41 with ulcerative colitis, 24 with indeterminate colitis, 23 with chronic liver disease, 17 with coeliac disease, and seven with irritable bowel syndrome. Additional comparisons were made between Crohn's disease and ulcerative colitis patients. Within the Crohn's disease group, the dependence of antibody levels on several clinical variables was assessed. RESULTS: IgG and IgA anti-sacc antibodies were significantly raised in Crohn's disease. IgG antibodies were also raised in patients with chronic liver disease. Among patients with Crohn's disease, IgG antibody concentrations were higher in those with serum alpha 1 acid glycoprotein (AAG) above the normal range and there was a strong trend towards increased IgG anti-sacc in the presence of small bowel disease, whereas IgA anti-sacc correlated positively with disease duration. No differences were detected according to whether patients were taking steroids. Neither the Crohn's disease nor the chronic liver disease group differed from normal subjects in respect of IgG antibodies to bovine milk casein. On linear regression analysis of complete data from 39 Crohn's disease patients, AAG was found to be a significant predictor of both IgG and IgA antibodies, and male sex and disease duration to be additional predictors of IgA antibodies. There was a significant difference in IgG antibodies between Crohn's disease and ulcerative colitis. CONCLUSIONS: Raised antibodies to yeast, although not completely specific for Crohn's disease, may have a future role in diagnosis. The assays described here could be used to address this question in the context of a prospective study. PMID:10343612

Antibody responses to bacteriophage phi X-174 in human subjects exposed to the antarctic winter-over model of spaceflight

NASA Technical Reports Server (NTRS)

Shearer, W. T.; Lugg, D. J.; Rosenblatt, H. M.; Nickolls, P. M.; Sharp, R. M.; Reuben, J. M.; Ochs, H. D.

2001-01-01

BACKGROUND: It has been proposed that exposure to long-term spaceflight conditions (stress, isolation, sleep disruption, containment, microbial contamination, and solar radiation) or to ground-based models of spaceflight will alter human immune responses, but specific antibody responses have not been fully evaluated. OBJECTIVE: We sought to determine whether exposure to the 8-month Antarctic winter-over model of spaceflight would alter human antibody responses. METHODS: During the 1999 Australian National Antarctic Research Expeditions, 11 adult study subjects at Casey, Antarctica, and 7 control subjects at Macquarie Island, sub-Antarctica, received primary and secondary immunizations with the T cell-dependent neoantigen bacteriophage phi X-174. Periodic plasma samples were analyzed for specific antibody function. RESULTS: All of the subjects from Casey, Antarctica, cleared bacteriophage phi X-174 normally by 1 week after primary immunization, and all had normal primary and secondary antibody responses, including immunologic memory amplification and switch from IgM to IgG antibody production. One subject showed a high normal pattern, and one subject had a low normal pattern. The control subjects from Macquarie Island also had normal immune responses to bacteriophage phi X-174. CONCLUSIONS: These data do not support the hypothesis that de novo specific antibody responses of subjects become defective during the conditions of the Antarctic winter-over. Because the Antarctic winter-over model of spaceflight lacks the important factors of microgravity and solar radiation, caution must be used in interpreting these data to anticipate normal antibody responses in long-term spaceflight.

[Human IgG subclass study. II. The levels of the individual IgG subclasses in paired sera from mothers and newborn infants as well as in the blood sera of inhabitants of an isolated northern village].

PubMed

Basova, E N; Stefani, D V; Kazantseva, L Z

1979-07-01

The levels of the first 3 subclasses of IgG, as determined by the radial immunodiffusion test, proved to be similar in the blood sera obtained from mothers and newborns in Moscow. The concentration of IgG4 was 0.64 +/- 0.02 g/l iently indicative of a limited passage of IgG4 molecules through the placenta. The inhabitants of an isolated northern village were found to have the inheritable combined deficit of IfG2 and IgG3 synthesis in their blood sera, which was probably due to the prolonged processes of inbreeding and the progenitor effect.

Serum IgG subclass levels and risk of exacerbations and hospitalizations in patients with COPD.

PubMed

Leitao Filho, Fernando Sergio; Ra, Seung Won; Mattman, Andre; Schellenberg, Robert S; Criner, Gerard J; Woodruff, Prescott G; Lazarus, Stephen C; Albert, Richard; Connett, John E; Han, Meilan K; Martinez, Fernando J; Leung, Janice M; Paul Man, S F; Aaron, Shawn D; Reed, Robert M; Sin, Don D

2018-02-14

The literature is scarce regarding the prevalence and clinical impact of IgG subclass deficiency in COPD. We investigated the prevalence of IgG subclass deficiencies and their association with exacerbations and hospitalizations using subjects from two COPD cohorts. We measured IgG subclass levels using immunonephelometry in serum samples from participants enrolled in two previous COPD trials: Macrolide Azithromycin for Prevention of Exacerbations of COPD (MACRO; n = 976) and Simvastatin for the Prevention of Exacerbations in Moderate-to-Severe COPD (STATCOPE; n = 653). All samples were collected from clinically stable participants upon entry into both studies. IgG subclass deficiency was diagnosed when IgG subclass levels were below their respective lower limit of normal: IgG1 < 2.8 g/L; IgG2 < 1.15 g/L; IgG3 < 0.24 g/L; and IgG4 < 0.052 g/L. To investigate the impact of IgG subclass levels on time to first exacerbation or hospitalization, we log-transformed IgG levels and performed Cox regression models, with adjustments for confounders. One or more IgG subclass deficiencies were found in 173 (17.7%) and 133 (20.4%) participants in MACRO and STATCOPE, respectively. Lower IgG1 or IgG2 levels resulted in increased risk of exacerbations with adjusted hazard ratios (HR) of 1.30 (95% CI, 1.10-1.54, p < 0.01) and 1.19 (95% CI, 1.05-1.35, p < 0.01), respectively in the MACRO study, with STATCOPE yielding similar results. Reduced IgG1 or IgG2 levels were also associated with increased risk of hospitalizations: the adjusted HR for IgG1 and IgG2 was 1.52 (95% CI: 1.15-2.02, p < 0.01) and 1.33 (95% CI, 1.08-1.64, p < 0.01), respectively for the MACRO study; in STATCOPE, only IgG2 was an independent predictor of hospitalization. In our multivariate Cox models, IgG3 and IgG4 levels did not result in significant associations for both outcomes in either MACRO or STATCOPE cohorts. Approximately 1 in 5 COPD patients had one or more IgG subclass deficiencies. Reduced IgG subclass levels were independent risk factors for both COPD exacerbations (IgG1 and IgG2) and hospitalizations (IgG2) in two COPD cohorts. This study used serum samples from participants of the MACRO ( NCT00325897 ) and STATCOPE ( NCT01061671 ) trials.

Identification and characterization of a Fc receptor activity on the Toxoplasma gondii tachyzoite.

PubMed

Vercammen, M; el Bouhdidi, A; Ben Messaoud, A; de Meuter, F; Bazin, H; Dubremetz, J F; Carlier, Y

1998-01-01

The Immunoglobulin (Ig) binding capacity of Toxoplasma gondii tachyzoites was investigated using fluorescence flow-cytometry analysis. Polyclonal mouse, human and rat immunoglobulins without specific anti-Toxoplasma activity bound to parasites in a concentration-dependent manner, saturating them at circulating serum concentrations. The immunoglobulin class and subclass specificity of binding was investigated using irrelevant monoclonal antibodies. IgM, IgA and IgG reacted with the parasite membrane. The attachment of mouse IgM to the parasite surface was hampered by mouse IgG1, IgG2a, IgG2b and IgG3. The binding of mouse IgG was proportionally reduced with increasing concentrations of mouse monoclonal IgM. The binding of murine immunoglobulin was diminished when in presence of human IgG. Purified Fc- but not Fab portions of immunoglobulins, fixed to parasites. Using labelled calibrated beads, the Ig binding capacity of parasites was estimated to be 6900 +/- 500 sites per tachyzoite. The Kd of the T. gondii Fc Receptor (FcR) activity was determined at 1.4 +/- 0.1 microM (mean +/- SEM). Such FcR activity was reduced by phospholipase C, trypsin and pronase treatment of the parasites. These data show a low affinity FcR activity on T. gondii tachyzoites which recognizes Ig of different species and isotypes and is likely supported by a glycosyl-phosphatidylinositol (GPI)-anchored surface protein of the parasite.

Normal mitogen-induced suppression of the interleukin-6 (IL-6) response and its deficiency in systemic lupus erythematosus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Warrington, R.J.; Rutherford, W.J.

1990-01-01

A low-frequency suppressor-cell population in normal peripheral blood inhibits the B-cell CESS response to IL-6, following pokeweed mitogen stimulation. The suppression of IL-6 responsiveness is radiation sensitive, directed against CESS targets and not mediated by inhibition of IL-6 production, and associated with nonspecific cytotoxic activity against CESS targets. The generation of these cytolytic cells is also radiation sensitive. A correlation was found between PWM-induced cytotoxicity against CESS and the suppression of IL-6-dependent IgG production. But cytotoxicity toward CESS targets is not responsible for this suppression because IL-2 induces equivalent or greater nonspecific cytotoxicity against CESS in the total absence ofmore » suppression of CESS-derived IgG production and suppression is also induced by mitogen-activated PBL separated from CESS targets by a cell-impermeable membrane. This suppression was not mediated by TNF alpha/beta or IFN-gamma. In systemic lupus erythematosus, suppression of IL-6-dependent IgG production is impaired in patients with active disease (29.2 +/- 13.7%) compared to patients with inactive disease (70 +/- 19.5%) or normal controls (82.8 +/- 9.2%). There is also a defect in mitogen-induced nonspecific cytotoxicity in active SLE (specific lysis 15.1 +/- 3.5%, compared to 34 +/- 4% in normals). Pokeweed mitogen-activated PBL can therefore normally induce suppression of B-cell IL-6 responses and this response is deficient in lupus.« less

Seroprevalence of human parvovirus B19 in healthy blood donors

PubMed Central

Kumar, Satish; Gupta, R.M.; Sen, Sourav; Sarkar, R.S.; Philip, J.; Kotwal, Atul; Sumathi, S.H.

2013-01-01

Background Human parvovirus B19 is an emerging transfusion transmitted infection. Although parvovirus B19 infection is connected with severe complications in some recipients, donor screening is not yet mandatory. To reduce the risk of contamination, plasma-pool screening and exclusion of highly viraemic donations are recommended. In this study the prevalence of parvovirus B19 in healthy blood donors was detected by ELISA. Methods A total of 1633 samples were screened for IgM and IgG antibodies against parvovirus B19 by ELISA. The initial 540 samples were screened for both IgM and IgG class antibodies and remaining 1093 samples were screened for only IgM class antibodies by ELISA. Results Net prevalence of IgM antibodies to human parvovirus B19 in our study was 7.53% and prevalence of IgG antibodies was 27.96%. Dual positivity (IgG and IgM) was 2.40%. Conclusion The seroprevalence of human parvovirus B19 among blood donor population in our study is high, and poses an adverse transfusion risk especially in high-risk group of patients who have no detectable antibodies to B19. Studies with large sample size are needed to validate these results. PMID:24600121

Seroprevalence of human parvovirus B19 in healthy blood donors.

PubMed

Kumar, Satish; Gupta, R M; Sen, Sourav; Sarkar, R S; Philip, J; Kotwal, Atul; Sumathi, S H

2013-07-01

Human parvovirus B19 is an emerging transfusion transmitted infection. Although parvovirus B19 infection is connected with severe complications in some recipients, donor screening is not yet mandatory. To reduce the risk of contamination, plasma-pool screening and exclusion of highly viraemic donations are recommended. In this study the prevalence of parvovirus B19 in healthy blood donors was detected by ELISA. A total of 1633 samples were screened for IgM and IgG antibodies against parvovirus B19 by ELISA. The initial 540 samples were screened for both IgM and IgG class antibodies and remaining 1093 samples were screened for only IgM class antibodies by ELISA. Net prevalence of IgM antibodies to human parvovirus B19 in our study was 7.53% and prevalence of IgG antibodies was 27.96%. Dual positivity (IgG and IgM) was 2.40%. The seroprevalence of human parvovirus B19 among blood donor population in our study is high, and poses an adverse transfusion risk especially in high-risk group of patients who have no detectable antibodies to B19. Studies with large sample size are needed to validate these results.

Human FcγRIIA induces anaphylactic and allergic reactions

PubMed Central

Jönsson, Friederike; Mancardi, David A.; Zhao, Wei; Kita, Yoshihiro; Iannascoli, Bruno; Khun, Huot; van Rooijen, Nico; Shimizu, Takao; Schwartz, Lawrence B.; Daëron, Marc

2012-01-01

IgE and IgE receptors (FcϵRI) are well-known inducers of allergy. We recently found in mice that active systemic anaphylaxis depends on IgG and IgG receptors (FcγRIIIA and FcγRIV) expressed by neutrophils, rather than on IgE and FcϵRI expressed by mast cells and basophils. In humans, neutrophils, mast cells, basophils, and eosinophils do not express FcγRIIIA or FcγRIV, but FcγRIIA. We therefore investigated the possible role of FcγRIIA in allergy by generating novel FcγRIIA-transgenic mice, in which various models of allergic reactions induced by IgG could be studied. In mice, FcγRIIA was sufficient to trigger active and passive anaphylaxis, and airway inflammation in vivo. Blocking FcγRIIA in vivo abolished these reactions. We identified mast cells to be responsible for FcγRIIA-dependent passive cutaneous anaphylaxis, and monocytes/macrophages and neutrophils to be responsible for FcγRIIA-dependent passive systemic anaphylaxis. Supporting these findings, human mast cells, monocytes and neutrophils produced anaphylactogenic mediators after FcγRIIA engagement. IgG and FcγRIIA may therefore contribute to allergic and anaphylactic reactions in humans. PMID:22138510

Human FcγRIIA induces anaphylactic and allergic reactions.

PubMed

Jönsson, Friederike; Mancardi, David A; Zhao, Wei; Kita, Yoshihiro; Iannascoli, Bruno; Khun, Huot; van Rooijen, Nico; Shimizu, Takao; Schwartz, Lawrence B; Daëron, Marc; Bruhns, Pierre

2012-03-15

IgE and IgE receptors (FcεRI) are well-known inducers of allergy. We recently found in mice that active systemic anaphylaxis depends on IgG and IgG receptors (FcγRIIIA and FcγRIV) expressed by neutrophils, rather than on IgE and FcεRI expressed by mast cells and basophils. In humans, neutrophils, mast cells, basophils, and eosinophils do not express FcγRIIIA or FcγRIV, but FcγRIIA. We therefore investigated the possible role of FcγRIIA in allergy by generating novel FcγRIIA-transgenic mice, in which various models of allergic reactions induced by IgG could be studied. In mice, FcγRIIA was sufficient to trigger active and passive anaphylaxis, and airway inflammation in vivo. Blocking FcγRIIA in vivo abolished these reactions. We identified mast cells to be responsible for FcγRIIA-dependent passive cutaneous anaphylaxis, and monocytes/macrophages and neutrophils to be responsible for FcγRIIA-dependent passive systemic anaphylaxis. Supporting these findings, human mast cells, monocytes and neutrophils produced anaphylactogenic mediators after FcγRIIA engagement. IgG and FcγRIIA may therefore contribute to allergic and anaphylactic reactions in humans.

Uncoupling the widespread occurrence of anti-NMDAR1 autoantibodies from neuropsychiatric disease in a novel autoimmune model.

PubMed

Pan, Hong; Oliveira, Bárbara; Saher, Gesine; Dere, Ekrem; Tapken, Daniel; Mitjans, Marina; Seidel, Jan; Wesolowski, Janina; Wakhloo, Debia; Klein-Schmidt, Christina; Ronnenberg, Anja; Schwabe, Kerstin; Trippe, Ralf; Mätz-Rensing, Kerstin; Berghoff, Stefan; Al-Krinawe, Yazeed; Martens, Henrik; Begemann, Martin; Stöcker, Winfried; Kaup, Franz-Josef; Mischke, Reinhard; Boretius, Susann; Nave, Klaus-Armin; Krauss, Joachim K; Hollmann, Michael; Lühder, Fred; Ehrenreich, Hannelore

2018-02-09

Autoantibodies of the IgG class against N-methyl-D-aspartate-receptor subunit-NR1 (NMDAR1-AB) were considered pathognomonic for anti-NMDAR encephalitis. This view has been challenged by the age-dependent seroprevalence (up to >20%) of functional NMDAR1-AB of all immunoglobulin classes found in >5000 individuals, healthy or affected by different diseases. These findings question a merely encephalitogenic role of NMDAR1-AB. Here, we show that NMDAR1-AB belong to the normal autoimmune repertoire of dogs, cats, rats, mice, baboons, and rhesus macaques, and are functional in the NMDAR1 internalization assay based on human IPSC-derived cortical neurons. The age dependence of seroprevalence is lost in nonhuman primates in captivity and in human migrants, raising the intriguing possibility that chronic life stress may be related to NMDAR1-AB formation, predominantly of the IgA class. Active immunization of ApoE -/- and ApoE +/+ mice against four peptides of the extracellular NMDAR1 domain or ovalbumin (control) leads to high circulating levels of specific AB. After 4 weeks, the endogenously formed NMDAR1-AB (IgG) induce psychosis-like symptoms upon MK-801 challenge in ApoE -/- mice, characterized by an open blood-brain barrier, but not in their ApoE +/+ littermates, which are indistinguishable from ovalbumin controls. Importantly, NMDAR1-AB do not induce any sign of inflammation in the brain. Immunohistochemical staining for microglial activation markers and T lymphocytes in the hippocampus yields comparable results in ApoE -/- and ApoE +/+ mice, irrespective of immunization against NMDAR1 or ovalbumin. These data suggest that NMDAR1-AB of the IgG class shape behavioral phenotypes upon access to the brain but do not cause brain inflammation on their own.

Aβ anti-idiotypic antibodies are present in intravenous immunoglobulin and are produced in mice following its administration.

PubMed

Loeffler, David A; Klaver, Andrea C; Coffey, Mary P

2015-06-01

The effects of intravenous immunoglobulin (IVIG) products were recently examined in patients with Alzheimer's disease (AD). Although encouraging results were obtained in pilot studies, later trials produced negative results. The rationale for these studies was that IVIG contains antibodies to amyloid-beta (Aβ). However, if Aβ anti-idiotypic antibodies (antibodies which bind to anti-Aβ antibodies) are present in IVIG or induced by its administration, these antibodies could potentially reduce its neuroprotective effects in AD. The objective of this study was to determine if IVIG contained such antibodies. Enzyme-linked immunosorbent assays (ELISAs) measured specific binding of IVIG Gamunex to purified human anti-Aβ IgG. The mean concentration of its Aβ anti-idiotypic antibodies in four experiments was 1.85 μg/mL (18.5 μg/g IgG; range = 1.82-1.89 μg/mL [18.2-18.9 μg/g IgG]), and their mean percentage of specific binding was 72.2% (range = 68.3-75.3%). We then performed ELISAs to determine if antibodies to purified human anti-Aβ were produced in C57BL/6 mice injected with the IVIG product Gammagard in an earlier study. After subtracting the expected immune response to normal human immunoglobulins, the median concentrations of these antibodies were 15.6 ng/mL (range = 1.2-108.2 ng/mL) in pre-treatment sera and 2419.4 ng/mL (range = 327.4-8478.4 ng/mL) in post-treatment sera. These results indicate that specific Aβ anti-idiotypic antibodies are detectable in IVIG and may be induced in mice by its administration. The presence of Aβ anti-idiotypic antibodies in IVIG products might decrease neuroprotective effects of their anti-Aβ antibodies in AD.

IgG red blood cell autoantibodies in autoimmune hemolytic anemia bind to epitopes on red blood cell membrane band 3 glycoprotein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Victoria, E.J.; Pierce, S.W.; Branks, M.J.

1990-01-01

Red blood cell (RBC) autoantibodies from patients with IgG warm-type autoimmune hemolytic anemia were labeled with iodine 125 and their RBC binding behavior characterized. Epitope-bearing RBC membrane polypeptides were identified after autoantibody immunoprecipitation of labeled membranes and immunoblotting. Immunoaffinity isolation of labeled membrane proteins with 12 different IgG hemolytic autoantibodies with protein A-agarose revealed a major polypeptide at Mr 95 to 110 kd, which coelectrophoresed on sodium dodecylsulfate-polyacrylamide gel electrophoresis with a membrane component isolated with sheep IgG anti-band 3. Immunoprecipitation studies with chymotrypsinized RBCs resulted in the recovery of two labeled membrane polypeptides with molecular weights characteristically resulting frommore » the chymotryptic fragmentation of band 3. Immunoblotting with sheep IgG anti-band 3 of the immunoprecipitated polypeptides confirmed that hemolytic autoantibody binding led to recovery of band 3 or its fragments. Two 125I-labeled IgG hemolytic autoantibodies showed binding behavior consistent with epitope localization on band 3. The labeled RBC autoantibodies bound immunospecifically to all types of human RBC tested, including those of rare Rh type (Rh-null, D--) at a site density of approximately 10(6) per RBC. The 125I-IgG in two labeled autoantibodies was 84% and 92% adsorbable by human and higher nonhuman primate RBCs. Antigen-negative animal RBC bound less than 10%, consistent with immunospecific RBC binding. IgG-1 was the major subclass in five autoantibodies tested; one of six fixed complement; and autoantibody IgG appeared polyclonal by isoelectric focusing. We conclude that IgG eluted from RBCs of patients with autoimmune hemolytic anemia consists predominantly of a single totally RBC-adsorbable antibody population that binds to antigenic determinants on band 3.« less

Nephrin redistribution on podocytes is a potential mechanism for proteinuria in patients with primary acquired nephrotic syndrome.

PubMed

Doublier, S; Ruotsalainen, V; Salvidio, G; Lupia, E; Biancone, L; Conaldi, P G; Reponen, P; Tryggvason, K; Camussi, G

2001-05-01

We investigated the distribution of nephrin by immunofluorescence microscopy in renal biopsies of patients with nephrotic syndrome: 13 with membranous glomerulonephritis (GN), 10 with minimal change GN, and seven with focal segmental glomerulosclerosis. As control, six patients with IgA GN without nephrotic syndrome and 10 normal controls were studied. We found an extensive loss of staining for nephrin and a shift from a podocyte-staining pattern to a granular pattern in patients with nephrotic syndrome, irrespective of the primary disease. In membranous GN, nephrin was co-localized with IgG immune deposits. In the attempt to explain these results, we investigated in vitro whether stimuli acting on the cell cytoskeleton, known to be involved in the pathogenesis of GN, may induce redistribution of nephrin on the surface of human cultured podocytes. Aggregated but not disaggregated human IgG(4), plasmalemmal insertion of membrane attack complex of complement, tumor necrosis factor-alpha, and puromycin, induced the shedding of nephrin with a loss of surface expression. This phenomenon was abrogated by cytochalasin and sodium azide. These results suggest that the activation of cell cytoskeleton may modify surface expression of nephrin allowing a dislocation from plasma membrane to an extracellular site.

Nephrin Redistribution on Podocytes Is a Potential Mechanism for Proteinuria in Patients with Primary Acquired Nephrotic Syndrome

PubMed Central

Doublier, Sophie; Ruotsalainen, Vesa; Salvidio, Gennaro; Lupia, Enrico; Biancone, Luigi; Conaldi, Pier Giulio; Reponen, Paula; Tryggvason, Karl; Camussi, Giovanni

2001-01-01

We investigated the distribution of nephrin by immunofluorescence microscopy in renal biopsies of patients with nephrotic syndrome: 13 with membranous glomerulonephritis (GN), 10 with minimal change GN, and seven with focal segmental glomerulosclerosis. As control, six patients with IgA GN without nephrotic syndrome and 10 normal controls were studied. We found an extensive loss of staining for nephrin and a shift from a podocyte-staining pattern to a granular pattern in patients with nephrotic syndrome, irrespective of the primary disease. In membranous GN, nephrin was co-localized with IgG immune deposits. In the attempt to explain these results, we investigated in vitro whether stimuli acting on the cell cytoskeleton, known to be involved in the pathogenesis of GN, may induce redistribution of nephrin on the surface of human cultured podocytes. Aggregated but not disaggregated human IgG4, plasmalemmal insertion of membrane attack complex of complement, tumor necrosis factor-α, and puromycin, induced the shedding of nephrin with a loss of surface expression. This phenomenon was abrogated by cytochalasin and sodium azide. These results suggest that the activation of cell cytoskeleton may modify surface expression of nephrin allowing a dislocation from plasma membrane to an extracellular site. PMID:11337370

Antibody in sera of patients infected with Trichomonas vaginalis is to trichomonad proteinases.

PubMed

Alderete, J F; Newton, E; Dennis, C; Neale, K A

1991-08-01

A recent report demonstrated the immunogenic character of the cysteine proteinases of Trichomonas vaginalis. It was of interest, therefore, to examine for the presence of serum anti-proteinase antibody among patients with trichomoniasis. An immunoprecipitation assay was used involving protein A-bearing Staphylococcus aureus first coated with the IgG fraction of goat anti-human Ig and then mixed with individual sera of patients to bind human antibody. These antibody-coated bacteria were then added to detergent extracts of T vaginalis. Bound immune complexes on S aureus were washed and solubilised for electrophoretic analysis on acrylamide copolymerised with gelatin for detection of proteinase activity. Sera from patients (50/50), but none from sera of normal, uninfected women, possessed IgG to numerous trichomonad cysteine proteinases. The presence of this serum anti-proteinase antibody disappeared after drug treatment and cure of patients of the T vaginalis infection. The commonality of the anti-proteinase antibody in the sera of patients with trichomoniasis provided evidence for the expression of the same repertoire of parasite proteinases during infection. These observations have important implications for the in vivo relevance of the proteinases and indicate that strategies to use a specific serum antibody response for diagnosis of this infection may be possible.

The binding of an anti-PD-1 antibody to FcγRΙ has a profound impact on its biological functions.

PubMed

Zhang, Tong; Song, Xiaomin; Xu, Lanlan; Ma, Jie; Zhang, Yanjuan; Gong, Wenfeng; Zhang, Yilu; Zhou, Xiaosui; Wang, Zuobai; Wang, Yali; Shi, Yingdi; Bai, Huichen; Liu, Ning; Yang, Xiaolong; Cui, Xinxin; Cao, Yanping; Liu, Qi; Song, Jing; Li, Yucheng; Tang, Zhiyu; Guo, Mingming; Wang, Lai; Li, Kang

2018-04-23

Antibodies targeting PD-1 have been demonstrated durable anti-cancer activity in certain cancer types. However, the anti-PD-1 antibodies are less or not efficacious in many situations, which might be attributed to co-expression of multiple inhibitory receptors or presence of immunosuppressive cells in the tumor microenvironment. Most of the anti-PD-1 antibodies used in clinical studies are of IgG4 isotype with the S228P mutation (IgG4 S228P ). The functional impact by the interaction of anti-PD-1 IgG4 S228P antibody with Fc gamma receptors (FcγRs) is poorly understood. To assess the effects, we generated a pair of anti-PD-1 antibodies: BGB-A317/IgG4 S228P and BGB-A317/IgG4-variant (abbreviated as BGB-A317), with the same variable regions but two different IgG4 Fc-hinge sequences. There was no significant difference between these two antibodies in binding to PD-1. However, BGB-A317/IgG4 S228P binds to human FcγRI with high affinity and mediates crosslinking between PD-1 and FcγRI. In contrast, BGB-A317 does neither. Further cell-based assays showed that such crosslinking could reverse the function of an anti-PD-1 antibody from blocking to activating. More importantly, the crosslinking induces FcγRI + macrophages to phagocytose PD-1 + T cells. In a mouse model transplanted with allogeneic human cancer cells and PBMCs, BGB-A317 showed significant tumor growth inhibition, whereas BGB-A317/IgG4 S228P had no such inhibition. Immunohistochemistry study revealed an inverse correlation between FcγRI + murine macrophage infiltration and the density of CD8 + PD-1 + human T cells within tumors in the BGB-A317/IgG4 S228P -treated group. These evidences suggested that FcγRI + binding and crosslinking had negative impact on the anti-PD-1 antibody-mediated anti-cancer activity.

LatY136F knock-in mouse model for human IgG4-related disease.

PubMed

Yamada, Kazunori; Zuka, Masahiko; Ito, Kiyoaki; Mizuguchi, Keishi; Kakuchi, Yasushi; Onoe, Tamehito; Suzuki, Yasunori; Yamagishi, Masakazu; Izui, Shozo; Malissen, Marie; Malissen, Bernard; Kawano, Mitsuhiro

2018-01-01

The adaptor protein Linker for activation of T cell (LAT) is a key signaling hub used by the T cell antigen receptor. Mutant mice expressing loss-of-function mutations affecting LAT and including a mutation in which tyrosine 136 is replaced by a phenylalanine (LatY136F) develop lymphoproliferative disorder involving T helper type 2 effector cells capable of triggering a massive polyclonal B cell activation that leads to hypergammaglobulinemia G1 and E and to non-resolving inflammation and autoimmunity. The purpose of this study was to evaluate whether the phenotypes of LatY136F knock-in mice resemble the immunohistopathological features of immunoglobulin G4-related disease (IgG4-RD). LatY136F knock-in mice were sacrificed at 4-20 weeks of age, and pancreas, kidney, salivary gland and lung were obtained. All organs were stained with hematoxylin-eosin and with Azan for estimation of collagen in fibrosis, and the severity scores of inflammation and fibrosis were evaluated. Immunostainings were performed to analyze the types of infiltrating cells. In addition, the effects of corticosteroid treatment on the development of tissue lesions and serum levels of IgG1 were assessed. Tissue lesions characterized by inflammatory mononuclear cell infiltration and fibrosis were detected in pancreas, kidney, and salivary gland starting from 6 weeks of age. Immunostainings showed pronounced infiltration of plasma cells, CD4-positive T cells, and macrophages. Infiltrating plasma cells predominantly expressed IgG1. The extent of inflammation in pancreas and salivary glands was markedly reduced by corticosteroid treatment. LatY136F knock-in mice displayed increased production of Th2-type IgG1 (a homologue of human IgG4) and developed multiple organ tissue lesions reminiscent of those seen in patients with IgG4-RD. Moreover, the development of these tissue lesions was highly sensitive to corticosteroid treatment like in IgG4-RD. For these reasons we consider the LatY136F knock-in mouse strain to represent a promising model for human IgG4-RD.

IgG4 subclass antibodies impair antitumor immunity in melanoma

PubMed Central

Karagiannis, Panagiotis; Gilbert, Amy E.; Josephs, Debra H.; Ali, Niwa; Dodev, Tihomir; Saul, Louise; Correa, Isabel; Roberts, Luke; Beddowes, Emma; Koers, Alexander; Hobbs, Carl; Ferreira, Silvia; Geh, Jenny L.C.; Healy, Ciaran; Harries, Mark; Acland, Katharine M.; Blower, Philip J.; Mitchell, Tracey; Fear, David J.; Spicer, James F.; Lacy, Katie E.; Nestle, Frank O.; Karagiannis, Sophia N.

2013-01-01

Host-induced antibodies and their contributions to cancer inflammation are largely unexplored. IgG4 subclass antibodies are present in IL-10–driven Th2 immune responses in some inflammatory conditions. Since Th2-biased inflammation is a hallmark of tumor microenvironments, we investigated the presence and functional implications of IgG4 in malignant melanoma. Consistent with Th2 inflammation, CD22+ B cells and IgG4+-infiltrating cells accumulated in tumors, and IL-10, IL-4, and tumor-reactive IgG4 were expressed in situ. When compared with B cells from patient lymph nodes and blood, tumor-associated B cells were polarized to produce IgG4. Secreted B cells increased VEGF and IgG4, and tumor cells enhanced IL-10 secretion in cocultures. Unlike IgG1, an engineered tumor antigen-specific IgG4 was ineffective in triggering effector cell–mediated tumor killing in vitro. Antigen-specific and nonspecific IgG4 inhibited IgG1-mediated tumoricidal functions. IgG4 blockade was mediated through reduction of FcγRI activation. Additionally, IgG4 significantly impaired the potency of tumoricidal IgG1 in a human melanoma xenograft mouse model. Furthermore, serum IgG4 was inversely correlated with patient survival. These findings suggest that IgG4 promoted by tumor-induced Th2-biased inflammation may restrict effector cell functions against tumors, providing a previously unexplored aspect of tumor-induced immune escape and a basis for biomarker development and patient-specific therapeutic approaches. PMID:23454746

IgG4-Related Kidney Disease: Report of a Case Presenting as a Renal Mass

PubMed Central

Topazio, Luca; Gaziev, Gabriele; Iacovelli, Valerio; Bove, Pierluigi; Mauriello, Alessandro; Finazzi Agrò, Enrico

2017-01-01

IgG4-related disease (IgG4-RD) is a nosological entity defined as a chronic immune-mediated fibro-inflammatory condition characterized by a tendency to form tumefactive, tissue-destructive lesions or by organ failure. Urologic involvement in IgG4-RD has been described in some short series of patients and in isolated case reports, most often involving the kidneys in so-called IgG4-related kidney disease (IgG4-RKD). The disease can occasionally mimic malignancies and is at risk of being misdiagnosed due to its rarity. We report the case of a 56-year-old man presenting with a right renal mass suspected of being malignant. Laboratory tests showed normal creatinine levels, a high erythrocyte sedimentation rate, and high levels of C-reactive protein and microalbuminuria. The patient underwent radical right nephroureterectomy and histopathologic examination revealed features proving IgG4-RKD. He was therefore referred to immunologists. Typical clinical presentation of IgG4-RKD includes altered renal function with inconstant or no radiologic findings. Conversely, in the case we presented, a single nodule was detected upon imaging evaluation, thus mimicking malignancy. This raises the issue of a proper differential diagnosis. A multidisciplinary approach can be useful, although in clinical practice the selection of patients suspected of having IgG4-RKD is critical in the cases presenting with a renal mass that mimics malignancy. PMID:28912998

Hybrid kappa\\lambda antibody is a new serological marker to diagnose autoimmune pancreatitis and differentiate it from pancreatic cancer.

PubMed

Hao, Mingju; Li, Wenli; Yi, Lang; Yu, Songlin; Fan, Gaowei; Lu, Tian; Yang, Xin; Wang, Guojing; Zhang, Dong; Ding, Jiansheng; Zhang, Kuo; Zhang, Rui; Lin, Guigao; Han, Yanxi; Wang, Lunan; Li, Jinming

2016-06-08

The only generally accepted serological marker currently used for the diagnosis of autoimmune pancreatitis (AIP) is IgG4. Our aim was mainly to determine whether hybrid κ\\λ antibody can help to diagnose AIP and to differentiate it from pancreatic cancer. We established an enzyme-linked immunosorbent assay (ELISA) system to measure the levels of hybrid κ\\λ antibodies in human sera. Sera were obtained from 338 patients, including 61 with AIP, 74 with pancreatic cancer, 50 with acute pancreatitis, 40 with ordinary chronic pancreatitis, 15 with miscellaneous pancreatic diseases, and 98 with normal pancreas. Our study showed levels of hybrid κ\\λ antibodies in the AIP group were significantly higher than in the non-AIP group (P < 0.001). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for the diagnosis of AIP were 80.3%, 91%, 66.2% and 95.5% respectively. Furthermore, the combined measurement of serum hybrid κ\\λ antibody and IgG4 tended to increase the sensitivity although the difference was not statistically significant (90.2% vs. 78.7%, P = 0.08), compared to measurement of IgG4 alone. Our findings suggest that hybrid κ\\λ antibody could be a new serological marker to diagnose AIP and differentiate it from pancreatic cancer.

An autologous dendritic cell canine mammary tumor hybrid-cell fusion vaccine.

PubMed

Bird, R Curtis; Deinnocentes, Patricia; Church Bird, Allison E; van Ginkel, Frederik W; Lindquist, Joni; Smith, Bruce F

2011-01-01

Mammary cancer is among the most prevalent canine tumors and frequently resulting in death due to metastatic disease that is highly homologous to human breast cancer. Most canine tumors fail to raise effective immune reactions yet, some spontaneous remissions do occur. Hybrid canine dendritic cell-tumor cell fusion vaccines were designed to enhance antigen presentation and tumor immune recognition. Peripheral blood-derived autologous dendritic cell enriched populations were isolated from dogs based on CD11c(+) expression and fused with canine mammary tumor (CMT) cells for vaccination of laboratory Beagles. These hybrid cells were injected into popliteal lymph nodes of normal dogs, guided by ultrasound, and included CpG-oligonucleotide adjuvants. Three rounds of vaccination were delivered. Significant IgG responses were observed in all vaccinated dogs compared to vehicle-injected controls. Canine IgG antibodies recognized shared CMT antigens as was demonstrated by IgG-recognition of three unrelated/independently derived CMT cell lines, and recognition of freshly isolated, unrelated, primary biopsy-derived CMT cells. A bias toward an IgG2 isotype response was observed after two vaccinations in most dogs. Neither significant cytotoxic T cell responses were detected, nor adverse or side-effects due to vaccination or due to the induced immune responses noted. These data provide proof-of-principle for this cancer vaccine strategy and demonstrate the presence of shared CMT antigens that promote immune recognition of mammary cancer.

Characterization of a gene coding for a type IIo bacterial IgG-binding protein.

PubMed

Boyle, M D; Weber-Heynemann, J; Raeder, R; Podbielski, A

1995-06-01

Two antigenic classes of non-immune IgG-binding proteins can be expressed by group A streptococci. One antigenic group of proteins is recognized by an antibody prepared against the product of a cloned fcrA gene (anti-FcRA). In this study, the immunogen used to prepare the antibody that defines the second antigenic class was shown to be the product of the emm-like (emmL) gene of M serotype 55 group A isolate, A928. The emmL55 gene expressed in E. coli produced an M(r) approximately 58,000 molecule which bound human IgG1, IgG2, IgG3 and IgG4, as well as horse, rabbit and pig IgG in a non-immune fashion. These properties are characteristic of the previously described type IIo IgG-binding protein isolated from this strain. In addition, the recombinant protein was reactive with human serum albumin and fibrinogen. The emmL 55 gene sequence was analysed and found to have the organization and sequence characteristics of a typical class I emm-like gene.

[Possibility of the species identification using blood stains located on the material evidences and bone fragments with the method of solid phase enzyme immunoassay with "IgG general-EIA-BEST" kit and human immunoglobulin G].

PubMed

Sidorov, V L; Shvetsova, I V; Isakova, I V

2007-01-01

The authors give the comparative analysis of Russian and foreign forensic medical methods of species character identification of the blood from the stains on the material evidences and bone fragments. It is shown that for this purpose it is feasible to apply human immunoglobulin G (IgG) and solid phase enzyme immunoassay (EIA) with the kit "IgG general-EIA-BEST". In comparison with the methods used in Russia this method is more sensitive, convenient for objective registration and computer processing. The results of experiments shown that it is possible to use the kit "IgG general-EIA-BEST" in forensic medicine for the species character identification of the blood from the stains on the material evidences and bone fragments.

Determination of the molecular weight of human gamma-3 chains by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate

PubMed Central

Virella, G.; Parkhouse, R. M. E.

1972-01-01

The molecular weights (mol. wt) for heavy chains of human IgG were estimated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate. Polyclonal IgG and monoclonal IgG proteins of different subclasses were extensively reduced with 50 mM dithioerythritol, in the presence of 2 per cent sodium dodecyl sulphate, at 100°. Four control proteins of known mol. wt (cytochrome C, chymotrypsinogen A, egg albumin, and serum albumin) were used to construct a linear plot of electrophoretic mobility versus log mol. wt. From this plot, the following mol. wts were calculated: 53,650±700 for polyclonal IgG; 54,200±1065 for γ1, γ2, and γ4 chains, and 60,950±585 for γ3 chains. Those results confirm the larger size of γ3 chains reported by Saluk and Clem (1971). PMID:4346255

Human monoclonal antibody homodimers. Effect of valency on in vitro and in vivo antibacterial activity.

PubMed

Wolff, E A; Esselstyn, J; Maloney, G; Raff, H V

1992-04-15

Human IgG1 mAb dimers specific for either group B streptococci or Escherichia coli K1 bacteria were formed using chemical cross-linkers. The effect of antibody valency on biologic efficacy was investigated by comparing the IgG dimers against the corresponding IgG monomers. Binding activity and relative avidity were assessed using Ag binding and competition ELISA, and functional activity was analyzed using opsonophagocytic assays. These in vitro assays revealed that the dimers were greater than or equal to 50-fold more active than the monomers. A neonatal rat infection model showed the in vivo protective efficacy of the dimers was greater than or equal to 20-fold greater than that of the monomers. Enhancing the activity of mAb by chemical cross-linking may be a useful strategy for salvaging low affinity IgG mAb that possess poor functional properties.

Detection of Antibodies to Brucella Cytoplasmic Proteins in the Cerebrospinal Fluid of Patients with Neurobrucellosis

PubMed Central

Baldi, Pablo C.; Araj, George F.; Racaro, Graciela C.; Wallach, Jorge C.; Fossati, Carlos A.

1999-01-01

The diagnosis of human neurobrucellosis usually relies on the detection of antibodies to Brucella lipopolysaccharide (LPS) in cerebrospinal fluid (CSF) by agglutination tests or enzyme-linked immunosorbent assay (ELISA). Here we describe the detection of immunoglobulin G (IgG) to cytoplasmic proteins (CP) of Brucella spp. by ELISA and Western blotting in seven CSF samples from five patients with neurobrucellosis. While IgG to CP (titers of 200 to 12,800) and IgG to LPS (800 to 6,400) were found in the CSF of these patients, these antibodies were not detected in CSF samples from two patients who had systemic brucellosis without neurological involvement. The latter, however, had serum IgG and IgM to both LPS and CP. No reactivity to these antigens was found in CSF samples from 14 and 20 patients suffering from nonbrucellar meningitis and noninfectious diseases, respectively. These findings suggest that, in addition to its usefulness in the serological diagnosis of human systemic brucellosis, the ELISA with CP antigen can be used for the specific diagnosis of human neurobrucellosis. PMID:10473531

IgG responses to the gSG6-P1 salivary peptide for evaluating human exposure to Anopheles bites in urban areas of Dakar region, Sénégal

PubMed Central

2012-01-01

Background Urban malaria can be a serious public health problem in Africa. Human-landing catches of mosquitoes, a standard entomological method to assess human exposure to malaria vector bites, can lack sensitivity in areas where exposure is low. A simple and highly sensitive tool could be a complementary indicator for evaluating malaria exposure in such epidemiological contexts. The human antibody response to the specific Anopheles gSG6-P1 salivary peptide have been described as an adequate tool biomarker for a reliable assessment of human exposure level to Anopheles bites. The aim of this study was to use this biomarker to evaluate the human exposure to Anopheles mosquito bites in urban settings of Dakar (Senegal), one of the largest cities in West Africa, where Anopheles biting rates and malaria transmission are supposed to be low. Methods One cross-sectional study concerning 1,010 (505 households) children (n = 505) and adults (n = 505) living in 16 districts of downtown Dakar and its suburbs was performed from October to December 2008. The IgG responses to gSG6-P1 peptide have been assessed and compared to entomological data obtained in or near the same district. Results Considerable individual variations in anti-gSG6-P1 IgG levels were observed between and within districts. In spite of this individual heterogeneity, the median level of specific IgG and the percentage of immune responders differed significantly between districts. A positive and significant association was observed between the exposure levels to Anopheles gambiae bites, estimated by classical entomological methods, and the median IgG levels or the percentage of immune responders measuring the contact between human populations and Anopheles mosquitoes. Interestingly, immunological parameters seemed to better discriminate the exposure level to Anopheles bites between different exposure groups of districts. Conclusions Specific human IgG responses to gSG6-P1 peptide biomarker represent, at the population and individual levels, a credible new alternative tool to assess accurately the heterogeneity of exposure level to Anopheles bites and malaria risk in low urban transmission areas. The development of such biomarker tool would be particularly relevant for mapping and monitoring malaria risk and for measuring the efficiency of vector control strategies in these specific settings. PMID:22424570

What do anti-Toxoplasma gondii IgA and IgG subclasses in human saliva indicate?

PubMed

Cañedo-Solares, I; Gómez-Chávez, F; Luna-Pastén, H; Ortiz-Alegría, L B; Flores-García, Y; Figueroa-Damián, R; Macedo-Romero, C A; Correa, D

2018-05-01

Diagnostic tests for toxoplasmosis are based on serological techniques due to their high sensitivity. Some IgG subclasses are related to clinical outcome in the congenital form. In this work, we determined the levels of IgG, IgA, IgG1, IgG2, IgG3 and IgG4 anti-Toxoplasma gondii antibodies in paired saliva and serum samples from 91 women by indirect ELISA using a crude extract of the RH strain. The levels of IgA, IgG2, IgG3 and IgG4 antibodies and, to a lesser extent, IgG1 did not correlate between saliva and serum, that is, most cases that were positive for one Ig class in a sample were negative or very low in the other, and vice versa. We also observed that most samples of saliva that were positive for one IgG subclass were also positive for at least 2 of the other 3; this contrasted with findings in serum, wherein each person was positive almost exclusively for one subclass, as demonstrated before by us and other researchers. Although these findings are disappointing for the use in diagnosis, the richer response in saliva might indicate local exposure to T. gondii antigens without systemic infection; thus, saliva might be reflecting a local (protective?) response against this protozoan. © 2018 John Wiley & Sons Ltd.

Neuron-derived IgG protects neurons from complement-dependent cytotoxicity.

PubMed

Zhang, Jie; Niu, Na; Li, Bingjie; McNutt, Michael A

2013-12-01

Passive immunity of the nervous system has traditionally been thought to be predominantly due to the blood-brain barrier. This concept must now be revisited based on the existence of neuron-derived IgG. The conventional concept is that IgG is produced solely by mature B lymphocytes, but it has now been found to be synthesized by murine and human neurons. However, the function of this endogenous IgG is poorly understood. In this study, we confirm IgG production by rat cortical neurons at the protein and mRNA levels, with 69.0 ± 5.8% of cortical neurons IgG-positive. Injury to primary-culture neurons was induced by complement leading to increases in IgG production. Blockage of neuron-derived IgG resulted in more neuronal death and early apoptosis in the presence of complement. In addition, FcγRI was found in microglia and astrocytes. Expression of FcγR I in microglia was increased by exposure to neuron-derived IgG. Release of NO from microglia triggered by complement was attenuated by neuron-derived IgG, and this attenuation could be reversed by IgG neutralization. These data demonstrate that neuron-derived IgG is protective of neurons against injury induced by complement and microglial activation. IgG appears to play an important role in maintaining the stability of the nervous system.

[Comparative study of immunoglobulins and specific antibodies in the sera of chronic brucellosis patients].

PubMed

Kichieva, B N; Chernysheva, M I; Zheludkov, M M; Musaeva, N B

1982-04-01

The data on the IgA, IgM and IgG levels in the sera of 89 patients with chronic brucellosis lasting for 1-10 years and longer are presented. The chronic form of brucellosis is characterized by the normal or low level of immunoglobulins. No correlation between the levels of IgG, IgM and the titer of specific antibodies has been established.

High-throughput Identification of DNA-Encoded IgG Ligands that Distinguish Active and Latent Mycobacterium Tuberculosis Infections

PubMed Central

Ndungu, John Maina; Suponitsky-Kroyter, Irena; Cavett, Valerie J.; McEnaney, Patrick J.; MacConnell, Andrew B.; Doran, Todd. M.; Ronacher, Katharina; Stanley, Kim; Utset, Ofelia; Walzl, Gerhard; Paegel, Brian M.; Kodadek, Thomas

2017-01-01

The circulating antibody repertoire encodes a patient's health status and pathogen exposure history, but identifying antibodies with diagnostic potential usually requires knowledge of the antigen(s). We previously circumvented this problem by screening libraries of bead-displayed small molecules against case and control serum samples to discover “epitope surrogates” (ligands of IgGs enriched in the case sample). Here, we describe an improved version of this technology that employs DNA-encoded libraries and high-throughput FACS-based screening to discover epitope surrogates that differentiate noninfectious/latent (LTB) patients from infectious/active TB (ATB) patients, which is imperative for proper treatment selection and antibiotic stewardship. Normal control/LTB (10 patients each, NCL) and ATB (10 patients) serum pools were screened against a library (5 × 106 beads, 448k unique compounds) using fluorescent anti-human IgG to label hit compound beads for FACS. Deep sequencing decoded all hit structures and each hit's occurrence frequencies. ATB hits were pruned of NCL hits and prioritized for resynthesis based on occurrence and homology. Several structurally homologous families were identified and 16/21 resynthesized representative hits validated as selective ligands of ATB serum IgGs (p < 0.005). The native secreted TB protein Ag85B (though not the E. coli recombinant form) competed with one of the validated ligands for binding to antibodies, suggesting that it mimics a native Ag85B epitope. The use of DNA-encoded libraries and FACS-based screening in epitope surrogate discovery reveals thousands of potential hit structures. Distilling this list down to several consensus chemical structures yielded a diagnostic panel for ATB composed of thermally stable and economically produced small molecule ligands in place of protein antigens. PMID:27957856

THE GLOMERULAR MESANGIUM

PubMed Central

Mauer, S. Michael; Sutherland, David E. R.; Howard, Richard J.; Fish, Alfred J.; Najarian, John S.; Michael, Alfred F.

1973-01-01

A mechanism of immune glomerular injury is described based on the fixation of antibody (Ab) to an antigen (Ag) that has localized in the glomerular mesangium. Rabbits were given, intravenously (i.v.), aggregated human IgG (AHIgG) or albumin (AHSA) and 10 h later, when the Ag by immunofluorescent microscopy was present in the mesangium, a kidney was removed and transplanted into a normal rabbit. The recipient then received, i.v., rabbit anti-HIgG or anti-HSA. Within minutes of Ab infusion, glomeruli of the donor kidney had polymorphonuclear (PMN) infiltration that over the next few hours became marked and was associated with glomerular cell swelling. At 24 h a decrease in PMN's and early mesangial proliferation was seen. By 3 days there was marked mesangial hypercellularity and increased mesangial matrix. Within minutes after Ab administration rabbit IgG, C3, and fibrin were seen in the glomerular mesangium. There was a fall in complement titer by 1 min after Ab infusion that was due to complement consumption by the donor kidney. Complement then returned to normal levels by 48 h. Significant glomerular injury did not occur (a) in the recipient's own kidney, (b) from Ag administration and transplantation without recipient Ab administration, or (c) from transplantation and Ab administration without prior Ag administration. These studies demonstrated that Ag localized in the glomerular mesangium can react with circulating Ab and complement resulting in severe glomerular injury. PMID:4570015

Testing UK blood donors for exposure to human parvovirus 4 using a time-resolved fluorescence immunoassay to screen sera and Western blot to confirm reactive samples.

PubMed

Maple, Peter A C; Beard, Stuart; Parry, Ruth P; Brown, Kevin E

2013-10-01

Human parvovirus 4 (ParV4), a newly described member of the family Parvoviridae, like B19V, has been found in pooled plasma preparations. The extent, and significance, of ParV4 exposure in UK blood donors remain to be determined and reliable detection of ParV4 immunoglobulin (Ig)G, using validated methods, is needed. With ParV4 virus-like particles a ParV4 IgG time-resolved fluorescence immunoassay (TRFIA) was developed. There is no gold standard or reference assay for measuring ParV4 IgG and the utility of the TRFIA was first examined using a panel of sera from people who inject drugs (PWIDS)--a high-prevalence population for ParV4 infection. Western blotting was used to confirm the specificity of TRFIA-reactive sera. Two cohorts of UK blood donor sera comprising 452 sera collected in 1999 and 156 sera collected in 2009 were tested for ParV4 IgG. Additional testing for B19V IgG, hepatitis C virus antibodies (anti-HCV), and ParV4 DNA was also undertaken. The rate of ParV4 IgG seroprevalence in PWIDS was 20.7% and ParV4 IgG was positively associated with the presence of anti-HCV with 68.4% ParV4 IgG-positive sera testing anti-HCV-positive versus 17.1% ParV4 IgG-negative sera. Overall seropositivity for ParV4 IgG, in 608 UK blood donors was 4.76%. The ParV4 IgG seropositivity for sera collected in 1999 was 5.08%, compared to 3.84% for sera collected in 2009. No ParV4 IgG-positive blood donor sera had detectable ParV4 DNA. ParV4 IgG has been found in UK blood donors and this finding needs further investigation. © 2013 American Association of Blood Banks.

Comparative evaluation of seven commercial products for human serum enrichment/depletion by shotgun proteomics.

PubMed

Pisanu, Salvatore; Biosa, Grazia; Carcangiu, Laura; Uzzau, Sergio; Pagnozzi, Daniela

2018-08-01

Seven commercial products for human serum depletion/enrichment were tested and compared by shotgun proteomics. Methods were based on four different capturing agents: antibodies (Qproteome Albumin/IgG Depletion kit, ProteoPrep Immunoaffinity Albumin and IgG Depletion Kit, Top 2 Abundant Protein Depletion Spin Columns, and Top 12 Abundant Protein Depletion Spin Columns), specific ligands (Albumin/IgG Removal), mixture of antibodies and ligands (Albumin and IgG Depletion SpinTrap), and combinatorial peptide ligand libraries (ProteoMiner beads), respectively. All procedures, to a greater or lesser extent, allowed an increase of identified proteins. ProteoMiner beads provided the highest number of proteins; Albumin and IgG Depletion SpinTrap and ProteoPrep Immunoaffinity Albumin and IgG Depletion Kit resulted the most efficient in albumin removal; Top 2 and Top 12 Abundant Protein Depletion Spin Columns decreased the overall immunoglobulin levels more than other procedures, whereas specifically gamma immunoglobulins were mostly removed by Albumin and IgG Depletion SpinTrap, ProteoPrep Immunoaffinity Albumin and IgG Depletion Kit, and Top 2 Abundant Protein Depletion Spin Columns. Albumin/IgG Removal, a resin bound to a mixture of protein A and Cibacron Blue, behaved less efficiently than the other products. Copyright © 2018 Elsevier B.V. All rights reserved.

Clinical, parasitological and immunological features of canal cleaners hyper-exposed to Schistosoma mansoni in the Sudan

PubMed Central

SATTI, M Z; SULAIMAN, S M; HOMEIDA, M M A; YOUNIS, S A; GHALIB, H W

1996-01-01

The present work was a longitudinal study on Schistosoma mansoni infection in occupationally hyperexposed canal cleaners in the Sudan and the influence of therapy on the parasitological and humoral immune parameters. Chronically infected canal cleaners (n = 28) were more resistant to reinfection (Fisher's exact test, P < 0.05) than newly recruited canal cleaners (n = 17). Chronically infected canal cleaners had a significantly higher degree of Symmers' fibrosis (χ2 = 19.1, P < 0.0001), significantly larger portal vein diameter (P < 0.05) and enlarged spleen (χ2 = 4.2, P < 0.05) than recently infected, newly recruited canal cleaners. ELISA was used to detect IgG, IgA and IgM in response to whole worm homogenate (WWH) and cercarial homogenate (CH). Chronically infected canal cleaners had significantly higher IgG to WWH antigen than newly recruited canal cleaners and normally exposed individuals (P < 0.05), while both chronically infected and newly recruited canal cleaners had higher IgG levels to CH antigen than normally exposed individuals (P < 0.05). The newly recruited canal cleaners had a significantly higher IgM level to CH antigen than chronically infected canal cleaners (P < 0.05). The IgG level to WWH antigen increased significantly after treatment in newly recruited canal cleaners and normally exposed individuals (P < 0.05). The IgA level to CH antigen increased significantly after treatment in the chronically infected group (P < 0.05). Comparison of the serological parameters between the different study groups with regards to infection and treatment is discussed. PMID:9099926

The prevalence of IgG4-related hypophysitis in 170 consecutive patients with hypopituitarism and/or central diabetes insipidus and review of the literature.

PubMed

Bando, Hironori; Iguchi, Genzo; Fukuoka, Hidenori; Taniguchi, Masaaki; Yamamoto, Masaaki; Matsumoto, Ryusaku; Suda, Kentaro; Nishizawa, Hitoshi; Takahashi, Michiko; Kohmura, Eiji; Takahashi, Yutaka

2014-02-01

The prevalence and clinical characteristics of IgG4-related hypophysitis remain unclear due to the limited number of case reports. Therefore, in this study, we screened consecutive outpatients with hypopituitarism and/or diabetes insipidus (DI) to estimate its prevalence. A total of 170 consecutive outpatients with hypopituitarism and/or central DI were screened at Kobe University Hospital for detecting IgG4-related hypophysitis by pituitary magnetic resonance imaging, measuring serum IgG4 concentrations, assessing the involvement of other organs, and carrying out an immunohistochemical analysis to detect IgG4-positive cell infiltration. Among the screened cases, 116 cases were excluded due to diagnosis of other causes such as tumors and congenital abnormalities. Additionally, 22 cases with isolated ACTH deficiency were analyzed and were found not to meet the criteria of IgG4-related hypophysitis. The remaining 32 cases were screened and seven were diagnosed with IgG4-related hypophysitis, of which three cases were diagnosed by analyzing pituitary specimens. IgG4-related hypophysitis was detected in 30% (seven of 23 patients) of hypophysitis cases and 4% of all hypopituitarism/DI cases. The mean age at the onset of IgG4-related hypophysitis was 61.8±8.8 years, and the serum IgG4 concentration was 191.1±78.3 mg/dl (normal values 5-105 mg/dl and values in IgG4-related disease (RD) ≥135 mg/dl). Pituitary gland and/or stalk swelling was observed in six patients, and an empty sella was observed in one patient. Multiple co-existing organ involvement was observed in four of the seven patients prior to the onset of IgG4-related hypophysitis. These data suggest that the prevalence of IgG4-related hypophysitis has been underestimated. We should also consider the possibility of the development of hypopituitarism/DI caused by IgG4-related hypophysitis during the clinical course of other IgG4-RDs.

A human anti-neuronal autoantibody against GABA B receptor induces experimental autoimmune agrypnia.

PubMed

Frisullo, Giovanni; Della Marca, Giacomo; Mirabella, Massimiliano; Caggiula, Marcella; Broccolini, Aldobrando; Rubino, Marco; Mennuni, Gioacchino; Tonali, Pietro Attilio; Batocchi, Anna Paola

2007-04-01

In the serum and cerebrospinal fluid of a patient with recurrent acute episodes of respiratory crises, autonomic symptoms and total insomnia (agrypnia), we identified a novel anti-neural complement fixing antibody directed against GABA(B) receptor (GABA(B)R). Patient purified IgG recognized a band of approximately 110 kDa on protein extracts of mouse cerebellum, cortex and brainstem and immunolabelled cultured Chinese hamster ovary (CHO) cells, transfected with human GABA(B)R1 and rat GABA(B)R2 receptors. Western blot analysis of transfected CHO homogenates showed the same band using both patient purified IgG and anti-GABA(B)R1 antibody. In order to verify the pathogenic role of these purified antibodies, we injected patient IgG intrathecally into cisterna magna of C57BL/6 mice pre-implanted with EEG electrodes and we observed severe ataxia followed by breathing depression and total suppression of slow wave sleep, as evidenced by EEG recording, in a dose-dependent manner. Immunohistochemistry on brain sections of mice injected with patient IgG showed the simultaneous presence of bound human IgG and C5b-9 deposits on Purkinje cells and cerebellar granular layer. After incubation with anti-GABA(B)R antibody, a marked reduction of receptor immunostaining was found with relative sparing of neuronal architecture. In conclusion we recognized an anti-neuronal autoantibody directed against GABA(B)R that is associated with autoimmune agrypnia and we showed that our patient purified IgG was able to induce in mice experimental autoimmune agrypnia characterized by a complex neurological syndrome affecting several CNS functions.

Brain Human Monoclonal Autoantibody from Sydenham Chorea Targets Dopaminergic Neurons in Transgenic Mice and Signals Dopamine D2 Receptor: Implications in Human Disease1

PubMed Central

Cox, Carol J.; Sharma, Meenakshi; Leckman, James F.; Zuccolo, Jonathan; Zuccolo, Amir; Kovoor, Abraham; Swedo, Susan E.; Cunningham, Madeleine W.

2013-01-01

How autoantibodies target the brain and lead to disease in disorders such as Sydenham chorea (SC) is not known. SC is characterized by autoantibodies against the brain and is the main neurologic manifestation of streptococcal-induced rheumatic fever. Previously, our novel SC-derived mAb 24.3.1 was found to recognize streptococcal and brain antigens. To investigate in vivo targets of human mAb 24.3.1, VH/VL genes were expressed in B cells of transgenic (Tg) mice as functional chimeric human VH 24.3.1 - mouse constant region IgG1a autoantibody. Chimeric human-mouse IgG1a autoantibody co-localized with tyrosine hydroxylase in the basal ganglia within dopaminergic neurons in vivo in VH 24.3.1 Tg mice. Both human mAb 24.3.1 and IgG1a in Tg sera were found to react with human dopamine D2 receptor (D2R). Reactivity of chorea-derived mAb 24.3.1 or SC IgG with D2R was confirmed by 1) dose dependent inhibitory signaling of D2R as a potential consequence of targeting dopaminergic neurons, 2) reaction with surface-exposed FLAG epitope-tagged D2R, and 3) blocking of Ab reactivity by an extracellular D2R peptide. IgG from SC and a related subset of streptococcal associated behavioral disorders called pediatric autoimmune neuropsychiatric disorder associated with streptococci (PANDAS) with small choreiform movements reacted in ELISA with D2R. Reaction with FLAG-tagged D2R distinguished SC from PANDAS while sera from both SC and PANDAS induced inhibitory signaling of D2R on transfected cells comparable to dopamine. Here we define a mechanism by which the brain may be altered by antibody in movement and behavioral disorders. PMID:24184556

Development of Two FhSAP2 Recombinant–Based Assays for Immunodiagnosis of Human Chronic Fascioliasis

PubMed Central

Shin, Sun Hee; Hsu, Angel; Chastain, Holly M.; Cruz, Lorna A.; Elder, Eric S.; Sapp, Sarah G. H.; McAuliffe, Isabel; Espino, Ana M.; Handali, Sukwan

2016-01-01

In the United States, infection with Fasciola hepatica has been identified as an emerging disease, primarily in immigrants, refugees, and travelers. The laboratory test of choice for diagnosis of fascioliasis is detection of disease specific antibodies, most commonly uses excretory-secretory antigens for detection of IgG antibodies. Recently, recombinant proteins such as F. hepatica antigen (FhSAP2) have been used to detect IgG antibodies. The glutathione S-transferase (GST)–FhSAP2 recombinant antigen was used to develop Western blot (WB) and fluorescent bead-based (Luminex) assays to detect F. hepatica total IgG and IgG4 antibodies. The sensitivity and specificity of GST-FhSAP2 total IgG and IgG4 WB were similar at 94% and 98%, respectively. For the IgG Luminex assay, the sensitivity and specificity were 94% and 97%, and for the IgG4, the values were 100% and 99%, respectively. In conclusion, the GST-FhSAP2 antigen performs well in several assay formats and can be used for clinical diagnosis. PMID:27549636

Development of Two FhSAP2 Recombinant-Based Assays for Immunodiagnosis of Human Chronic Fascioliasis.

PubMed

Shin, Sun Hee; Hsu, Angel; Chastain, Holly M; Cruz, Lorna A; Elder, Eric S; Sapp, Sarah G H; McAuliffe, Isabel; Espino, Ana M; Handali, Sukwan

2016-10-05

In the United States, infection with Fasciola hepatica has been identified as an emerging disease, primarily in immigrants, refugees, and travelers. The laboratory test of choice for diagnosis of fascioliasis is detection of disease specific antibodies, most commonly uses excretory-secretory antigens for detection of IgG antibodies. Recently, recombinant proteins such as F. hepatica antigen (FhSAP2) have been used to detect IgG antibodies. The glutathione S-transferase (GST)-FhSAP2 recombinant antigen was used to develop Western blot (WB) and fluorescent bead-based (Luminex) assays to detect F. hepatica total IgG and IgG 4 antibodies. The sensitivity and specificity of GST-FhSAP2 total IgG and IgG 4 WB were similar at 94% and 98%, respectively. For the IgG Luminex assay, the sensitivity and specificity were 94% and 97%, and for the IgG 4 , the values were 100% and 99%, respectively. In conclusion, the GST-FhSAP2 antigen performs well in several assay formats and can be used for clinical diagnosis. © The American Society of Tropical Medicine and Hygiene.

Route and method of delivery of DNA vaccine influence immune responses in mice and non-human primates.

PubMed Central

McCluskie, M. J.; Brazolot Millan, C. L.; Gramzinski, R. A.; Robinson, H. L.; Santoro, J. C.; Fuller, J. T.; Widera, G.; Haynes, J. R.; Purcell, R. H.; Davis, H. L.

1999-01-01

BACKGROUND: In spite of the large number of studies that have evaluated DNA-based immunization, few have directly compared the immune responses generated by different routes of immunization, particularly in non-human primates. Here we examine the ability of a hepatitis B surface antigen (HBsAg)-encoding plasmid to induce immune responses in mice and non-human primates (rhesus monkeys: Macaca mulatta) after delivery by a number of routes. MATERIALS AND METHODS: Eight different injected [intraperitoneal (IP), intradermal (ID), intravenous (IV), intramuscular (IM), intraperineal (IPER), subcutaneous (SC), sublingual (SL), vaginal wall (VW)] and six noninjected [intranasal inhalation (INH), intranasal instillation (INS), intrarectal (IR), intravaginal (IVAG), ocular (Oc), oral feeding (oral)] routes and the gene gun (GG) were used to deliver HBsAg-expressing plasmid DNA to BALB/c mice. Sera were assessed for HBsAg-specific antibodies (anti-HBs, IgG, IgG1, IgG2a) and cytotoxic T lymphocyte (CTL) activity measured. Three of the most commonly used routes (IM, ID, GG) were compared in rhesus monkeys, also using HBsAg-expressing vectors. Monkeys were immunized with short (0-, 4- and 8-week) or long (0-, 12- and 24-week) intervals between boosts, and in the case of GG, also with different doses, and their sera were assessed for anti-HBs. RESULTS: In one study, anti-HBs were detected in plasma of mice treated by five of eight of the injected and none of the six noninjected routes. The highest levels of anti-HBs were induced by IM and IV injections, although significant titers were also obtained with SL and ID. Each of these routes also induced CTL, as did IPER and VW and one noninjected route (INH) that failed to induce antibodies. In a second study, GG (1.6 microg) was compared to ID and IM (100 microg) delivery. Significant titers were obtained by all routes after only one boost, with the highest levels detected by IM. Delivery to the skin by GG induced exclusively IgG1 antibodies (Th2-like) at 4 weeks and only very low IgG2a levels at later times; ID-immunized mice had predominantly IgG1 at 4 weeks and this changed to mixed IgG1/IgG2a over time. Responses with IM injection (in the leg or tongue) were predominantly IgG2a (Th1-like) at all times. IV injection gave mixed IgG1/IgG2a responses. In monkeys, in the first experiment, 1 mg DNA IM or ID at 0, 4, and 8 weeks gave equivalent anti-HB titers and 0.4 microg at the same times by GG induced lower titers. In the second experiment, 1 mg DNA IM or ID, or 3.2 microg by GG, at 0, 12, and 24 weeks, gave anti-HB values in the hierarchy of GG > IM > ID. Furthermore, high titers were retained after a single immunization in mice but fell off over time in the monkeys, even after boost. CONCLUSIONS: Route of administration of plasmid DNA vaccines influences the strength and nature of immune responses in mice and non-human primates. However, the results in mice were not always predictive of those in monkeys and this is likely true for humans as well. Optimal dose and immunization schedule will most likely vary between species. It is not clear whether results in non-human primates will be predictive of results in humans, thus additional studies are required. http://link.springer-ny.com/link/service/journals/00020/bibs /5n5p287. html Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:10390545

Transmission spectroscopy of dengue viral infection Transmission spectroscopy of dengue viral infection

NASA Astrophysics Data System (ADS)

Firdous, S.; Ahmed, M.; Rehman, A.; Nawaz, M.; Anwar, S.; Murtaza, S.

2012-04-01

We presented the rapid diagnostic test for dengue infection based on light spectrum of human blood. The transmission spectra of dengue infected whole blood samples have been recorded in ultra violet to near infrared range (400 - 800 nm) of about 30 conformed infected patients and compared to normal blood samples. Transmission spectra of dengue infected blood illustrate a strong band from 400 - 600 nm with prominant peaks at 540 and 580 nm, where is in case of normal blood below 600 nm, total absorption has been observed. These prominent peaks from 400 - 600 nm are characteristics of cells damage and dangue virus antibodies immunoglobulin G (IgG) and immunoglobulin M (IgM) produced against dengue antigen. The presented diagnostic method is non invasive, cost effective, easy and fast screening technique for dengue infected patients.

The incomplete anti-Rh antibody agglutination mechanism of trypsinized ORh+ red cells.

PubMed Central

Margni, R A; Leoni, J; Bazzurro, M

1977-01-01

The capacity for binding to trypsinized and non-trypsinized ORh+ red cells, of the IgG incomplete anti-Rh antibody and its F(ab')2 and Fc fragments has been investigated. An analysis has also been made of the capacity of non-specific human IgG, aggregated non-specific human IgG, human IgM (19S) and IgM (7S), and of fragments Fcgamma, Fcmu and Fc5mu to inhibit the agglutination of trypsinized ORh+ red cells by the IgG incomplete anti-Rh antibody. The results obtained indicate that these antibodies behave in a similar manner to that of nonprecipitating antibodies, and that the agglutination of trypsinized red cells seems to be a mixed reaction due to the interaction of an Fab fragment with its Rh antigenic determinant present in the surface of a red cell and the Fc of the same molecule with a receptor for Fc present in adjacent red cells. The trypsin treatment apparently results in the liberation of occult Fc receptors. It has also been demonstrated that in the agglutination of ORh+ red cells by IgG incomplete anti-Rh antibody in the presence of albumin, interaction must occur in some manner between the albumin and the Fc fragment since the F(ab')2 fragment does not give rise to agglutination under such conditions. Images Figure 1 PMID:415968

Production and characterization of anti-human IgG F(ab')2 antibody fragment.

PubMed

Valedkarimi, Zahra; Nasiri, Hadi; Aghebati-Maleki, Leili; Abdolalizadeh, Jalal; Esparvarinha, Mojghan; Majidi, Jafar

2018-04-10

In present study an optimized protocol for the separation of antibodies into antigen-binding fragments F(ab')2 using pepsin digestion was investigated. The production of these fragments is a consequential step in the development of medical research, treatment and diagnosis. For production of polyclonal antibody rabbit received antigen in four steps. The rabbit serum at 1/128000 dilution showed high absorbance in reaction with human IgG at the designed ELISA method. Rabbit IgG was purified by Ion-Exchange Chromatography (IEC) method. Purity was assessed by SDS-PAGE method. In non-reduced condition only one band was seen in about 150 kDa MW position and in reduced form, two bands were seen in 50 and 25 kDa MW positions. Rabbit IgG was digested by pepsin enzyme. The antibody fragments solution was applied to Gel filtration column to isolate the F(ab')2. Non-reduced SDS-PAGE for determining the purity of F(ab')2 fragment resulted in one band in 100 kDa corresponds to F(ab')2 fragment and a band in 150 kDa MW position corresponds to undigested IgG antibodies. The activities of FITC conjugated F(ab')2 fragment and commercial ones were compared using flowcytometry method. The activity results implied that the FITC conjugated- anti human F(ab')2 fragment worked as efficiently as the commercial one.

Conjugation of hydroxyapatite nanocrystals with human immunoglobulin G for nanomedical applications.

PubMed

Iafisco, Michele; Varoni, Elena; Di Foggia, Michele; Pietronave, Stefano; Fini, Milena; Roveri, Norberto; Rimondini, Lia; Prat, Maria

2012-02-01

Inorganic nanosized drug carriers are a promising field in nanomedicine applied to cancer. Their conjugation with antibodies combines the properties of the nanoparticles themselves with the specific and selective recognition ability of the antibodies to antigens. Biomimetic carbonate-hydroxyapatite (HA) nanoparticles were synthesized and fully characterized; human IgGs, used as model antibodies, were coupled to these nanocrystals. The maximum loading amount, the interaction modelling, the preferential orientation and the secondary structure modifications were evaluated using theoretical models (Langmuir, Freundlich and Langmuir-Freundlich) spectroscopic (UV-Vis, Raman), calorimetric (TGA), and immunochemical techniques (ELISA, Western Blot). HA nanoparticles of about 30 nm adsorbed human IgGs, in a dose-dependent, saturable and stable manner with micromolar affinity and adsorption capability around 2.3 mg/m(2). Adsorption isotherm could be described by Langmuir-Freundlich model, and was due to both energetically homogeneous and heterogeneous binding sites on HA surface, mainly of electrostatic nature. Binding did not induce secondary structure modification of IgGs. A preferential IgG end-on orientation with the involvement of IgG Fc moiety in the adsorption seems most probable due to the steric hindrance of their Fab domains. Biomimetic HA nanocrystals are suitable substrates to produce nanoparticles which can be functionalized with antibodies for efficient targeted drug delivery to tumours. Copyright © 2011 Elsevier B.V. All rights reserved.

The antigen-binding fragment of human gamma immunoglobulin prevents amyloid β-peptide folding into β-sheet to form oligomers

PubMed Central

Valls-Comamala, Victòria; Guivernau, Biuse; Bonet, Jaume; Puig, Marta; Perálvarez-Marín, Alex; Palomer, Ernest; Fernàndez-Busquets, Xavier; Altafaj, Xavier; Tajes, Marta; Puig-Pijoan, Albert; Vicente, Rubén; Oliva, Baldomero; Muñoz, Francisco J.

2017-01-01

The amyloid beta-peptide (Aβ) plays a leading role in Alzheimer's disease (AD) physiopathology. Even though monomeric forms of Aβ are harmless to cells, Aβ can aggregate into β-sheet oligomers and fibrils, which are both neurotoxic. Therefore, one of the main therapeutic approaches to cure or delay AD onset and progression is targeting Aβ aggregation. In the present study, we show that a pool of human gamma immunoglobulins (IgG) protected cortical neurons from the challenge with Aβ oligomers, as assayed by MTT reduction, caspase-3 activation and cytoskeleton integrity. In addition, we report the inhibitory effect of IgG on Aβ aggregation, as shown by Thioflavin T assay, size exclusion chromatography and atomic force microscopy. Similar results were obtained with Palivizumab, a human anti-sincitial virus antibody. In order to dissect the important domains, we cleaved the pool of human IgG with papain to obtain Fab and Fc fragments. Using these cleaved fragments, we functionally identified Fab as the immunoglobulin fragment inhibiting Aβ aggregation, a result that was further confirmed by an in silico structural model. Interestingly, bioinformatic tools show a highly conserved structure able to bind amyloid in the Fab region. Overall, our data strongly support the inhibitory effect of human IgG on Aβ aggregation and its neuroprotective role. PMID:28467807

Serologic Cross-Reactivity of Human IgM and IgG Antibodies to Five Species of Ebola Virus

PubMed Central

MacNeil, Adam; Reed, Zachary; Rollin, Pierre E.

2011-01-01

Five species of Ebola virus (EBOV) have been identified, with nucleotide differences of 30–45% between species. Four of these species have been shown to cause Ebola hemorrhagic fever (EHF) in humans and a fifth species (Reston ebolavirus) is capable of causing a similar disease in non-human primates. While examining potential serologic cross-reactivity between EBOV species is important for diagnostic assays as well as putative vaccines, the nature of cross-reactive antibodies following EBOV infection has not been thoroughly characterized. In order to examine cross-reactivity of human serologic responses to EBOV, we developed antigen preparations for all five EBOV species, and compared serologic responses by IgM capture and IgG enzyme-linked immunosorbent assay (ELISA) in groups of convalescent diagnostic sera from outbreaks in Kikwit, Democratic Republic of Congo (n = 24), Gulu, Uganda (n = 20), Bundibugyo, Uganda (n = 33), and the Philippines (n = 18), which represent outbreaks due to four different EBOV species. For groups of samples from Kikwit, Gulu, and Bundibugyo, some limited IgM cross-reactivity was noted between heterologous sera-antigen pairs, however, IgM responses were largely stronger against autologous antigen. In some instances IgG responses were higher to autologous antigen than heterologous antigen, however, in contrast to IgM responses, we observed strong cross-reactive IgG antibody responses to heterologous antigens among all sets of samples. Finally, we examined autologous IgM and IgG antibody levels, relative to time following EHF onset, and observed early peaking and declining IgM antibody levels (by 80 days) and early development and persistence of IgG antibodies among all samples, implying a consistent pattern of antibody kinetics, regardless of EBOV species. Our findings demonstrate limited cross-reactivity of IgM antibodies to EBOV, however, the stronger tendency for cross-reactive IgG antibody responses can largely circumvent limitations in the utility of heterologous antigen for diagnostic assays and may assist in the development of antibody-mediated vaccines to EBOV. PMID:21666792

A rheumatoid arthritis study by Fourier transform infrared spectroscopy

NASA Astrophysics Data System (ADS)

Carvalho, Carolina S.; Silva, Ana Carla A.; Santos, Tatiano J. P. S.; Martin, Airton A.; dos Santos Fernandes, Ana Célia; Andrade, Luís E.; Raniero, Leandro

2012-01-01

Rheumatoid arthritis is a systemic inflammatory disease of unknown causes and a new methods to identify it in early stages are needed. The main purpose of this work is the biochemical differentiation of sera between normal and RA patients, through the establishment of a statistical method that can be appropriately used for serological analysis. The human sera from 39 healthy donors and 39 rheumatics donors were collected and analyzed by Fourier Transform Infrared Spectroscopy. The results show significant spectral variations with p<0.05 in regions corresponding to protein, lipids and immunoglobulins. The technique of latex particles, coated with human IgG and monoclonal anti-CRP by indirect agglutination known as FR and CRP, was performed to confirm possible false-negative results within the groups, facilitating the statistical interpretation and validation of the technique.

In vivo fate of 125I SS-B (La) injected into mice.

PubMed Central

Schrieber, L; Erhardt, C C; Melsom, R D; Venables, P J; McCarthy, D A; Mumford, P A; Horsfall, A C; Maini, R N

1983-01-01

The fate of the radiolabelled soluble cellular antigen SS-B (La) was compared with that of other 125I-labelled proteins of known molecular weight (MW) and electrostatic charge, following i.v. injection into BALB/c mice. The plasma half-life of 125I-SS-B was 3 min, while that of 125I-bovine serum albumin (similar MW and electrostatic charge) was 270 min. 125I-heat-aggregated IgG (MW greater than 1 x 10(6)) and 125I-7S human IgG (MW 168,000) had plasma half-lives of 40 min and greater than 300 min, respectively. Liver and kidney showed preferential uptake of 125I-SS-B, followed by a rapid decrease in radioactivity. During this time low MW, trichloroacetic acid (TCA) soluble, material appeared in urine. This suggests a specific uptake mechanism followed by a catabolic phase. These studies demonstrate that normal mice remove 125I-SS-B rapidly from the circulation and then degrade it. This rapid antigen elimination may protect against the induction of potentially harmful autoantibody responses. PMID:6832805

Comparison of humanized IgG and FvFc anti-CD3 monoclonal antibodies expressed in CHO cells.

PubMed

Serpieri, Flavia; Inocencio, Andre; de Oliveira, Jose Marcelino; Pimenta, Alécio A; Garbuio, Angélica; Kalil, Jorge; Brigido, Marcelo M; Moro, Ana Maria

2010-07-01

Two humanized monoclonal antibody constructs bearing the same variable regions of an anti-CD3 monoclonal antibody, whole IgG and FvFc, were expressed in CHO cells. Random and site-specific integration were used resulting in similar expression levels. The transfectants were selected with appropriate selection agent, and the surviving cells were plated in semi-solid medium for capture with FITC-conjugated anti-human IG antibody and picked with the robotic ClonePix FL. Conditioned media from selected clones were purified by affinity chromatography and characterized by SDS-PAGE, Western-blot, SEC-HPLC, and isoelectric focusing. Binding to the target present in healthy human mononuclear cells was assessed by flow cytometry, as well as by competition between the two constructs and the original murine monoclonal antibody. The humanized constructs were not able to dislodge the murine antibody while the murine anti-CD3 antibody could dislodge around 20% of the FvFc or IgG humanized versions. Further in vitro and in vivo pre-clinical analyses will be carried out to verify the ability of the humanized versions to demonstrate the immunoregulatory profile required for a humanized anti-CD3 monoclonal antibody.

Changes in complementarity-determining regions significantly alter IgG binding to the neonatal Fc receptor (FcRn) and pharmacokinetics

PubMed Central

King, Amy C.; Kavosi, Mania; Wang, Mengmeng; O'Hara, Denise M.; Tchistiakova, Lioudmila; Katragadda, Madan

2018-01-01

ABSTRACT A large body of data exists demonstrating that neonatal Fc receptor (FcRn) binding of an IgG via its Fc CH2-CH3 interface trends with the pharmacokinetics (PK) of IgG. We have observed that PK of IgG molecules vary widely, even when they share identical Fc domains. This led us to hypothesize that domains distal from the Fc could contribute to FcRn binding and affect PK. In this study, we explored the role of these IgG domains in altering the affinity between IgG and FcRn. Using a surface plasmon resonance-based assay developed to examine the steady-state binding affinity (KD) of IgG molecules to FcRn, we dissected the contributions of IgG domains in modulating the affinity between FcRn and IgG. Through analysis of a broad collection of therapeutic antibodies containing more than 50 unique IgG molecules, we demonstrated that variable domains, and in particular complementarity-determining regions (CDRs), significantly alter binding affinity to FcRn in vitro. Furthermore, a panel of IgG molecules differing only by 1–5 mutations in CDRs altered binding affinity to FcRn in vitro, by up to 79-fold, and the affinity values correlated with calculated isoelectric point values of both variable domains and CDR-L3. In addition, tighter affinity values trend with faster in vivo clearance of a set of IgG molecules differing only by 1–3 mutations in human FcRn transgenic mice. Understanding the role of CDRs in modulation of IgG affinity to FcRn in vitro and their effect on PK of IgG may have far-reaching implications in the optimization of IgG therapeutics. PMID:28991504

A novel immunoassay based on the dissociation of immunocomplex and fluorescence quenching by gold nanoparticles.

PubMed

Peng, Zhaofeng; Chen, Zhaopeng; Jiang, Jianhui; Zhang, Xiaobing; Shen, Guoli; Yu, Ruqin

2007-01-30

This study reports a novel, simple and sensitive immunoassay using fluorescence quenching caused by gold nanoparticles coated with antibody. The method is based on a non-competitive heterogeneous immunoassay of human IgG conducted by the typical procedure of sandwich immunocomplex formation. Goat anti-human IgG was first adsorbed on polystyrene microwells, and human IgG analyte was captured by the primary antibody and then sandwiched by antibody labeled with gold nanoparticles. The sandwich-type immunocomplex was subsequently dissociated by the mixed solution of sodium hydroxide and trisodium citrate, the solution obtained, which contains gold nanoparticles coated with antibody, was used to quench fluorescence. The fluorescence intensity of fluorescein at 517 nm was inversely proportional to the logarithm of the concentration of human IgG in the dynamic range of 10-5000 ng mL(-1) with a detection limit of 4.7 ng mL(-1). The electrochemical experiments and the UV-vis measurements were applied to demonstrate whether the immunogold was dissociated completely and whether the gold nanoparticles aggregated after being dissociated, respectively. The proposed system can be extended to detect target molecules such as other kinds of antigen and DNA strands, and has broad potential applications in disease diagnosis.

Exploration of attenuated total reflectance mid-infrared spectroscopy and multivariate calibration to measure immunoglobulin G in human sera.

PubMed

Hou, Siyuan; Riley, Christopher B; Mitchell, Cynthia A; Shaw, R Anthony; Bryanton, Janet; Bigsby, Kathryn; McClure, J Trenton

2015-09-01

Immunoglobulin G (IgG) is crucial for the protection of the host from invasive pathogens. Due to its importance for human health, tools that enable the monitoring of IgG levels are highly desired. Consequently there is a need for methods to determine the IgG concentration that are simple, rapid, and inexpensive. This work explored the potential of attenuated total reflectance (ATR) infrared spectroscopy as a method to determine IgG concentrations in human serum samples. Venous blood samples were collected from adults and children, and from the umbilical cord of newborns. The serum was harvested and tested using ATR infrared spectroscopy. Partial least squares (PLS) regression provided the basis to develop the new analytical methods. Three PLS calibrations were determined: one for the combined set of the venous and umbilical cord serum samples, the second for only the umbilical cord samples, and the third for only the venous samples. The number of PLS factors was chosen by critical evaluation of Monte Carlo-based cross validation results. The predictive performance for each PLS calibration was evaluated using the Pearson correlation coefficient, scatter plot and Bland-Altman plot, and percent deviations for independent prediction sets. The repeatability was evaluated by standard deviation and relative standard deviation. The results showed that ATR infrared spectroscopy is potentially a simple, quick, and inexpensive method to measure IgG concentrations in human serum samples. The results also showed that it is possible to build a united calibration curve for the umbilical cord and the venous samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Immunoglobulin patterns in humans over 95 years of age.

PubMed Central

Radl, J; Sepers, J M; Skvaril, F; Morell, A; Hijmans, W

1975-01-01

Immunoglobulin patterns were investigated in seventy-three volunteers older than 95 years. An idiopathic paraproteinaemia was found in 19% of the cases. A restriction of heterogeneity and an imbalance in the kappa/lambda ratio of the immunoglobulins was seen in a number of other sera. Determinations of immunoglobulin levels in sera of individuals without paraproteinaemia showed an increase in IgA and IgG. The quantitations of the IgG subclasses demonstrated that an increase in the IgG1 and IgG3 subclasses is responsible for the elevated level of the IgG. The variation in the immunoglobulin levels increased significantly with age of IgM and for the three major IgG subclasses. No abnormalities were found in the urine or in the mixed saliva. These results indicate that selective changes in the extent of the antibody-immunoglobulin repertoire characterize the immunoglobulin pattern of ageing man. PMID:1212818

Mercaptoheterocyclic ligands grafted on a poly(ethylene vinyl alcohol) membrane for the purification of immunoglobulin G in a salt independent thiophilic chromatography.

PubMed

Coffinier, Yannick; Vijayalakshmi, Mookambeswaran A

2004-08-25

In this study, we attempted a limited combinatorial approach for designing affinity ligands based on mercaptoheterocyclic components. The template, divinyl sulfone structure (DVS), which was grafted on poly(ethylene vinyl alcohol) (PEVA) hollow fiber membrane, has served for the tethering of different heterocyclic compounds as pyridine, imidazole, purine and pyrimidine rings. Their ability to adsorb specifically IgG in a salt independent manner out of pure IgG solution, mixture of IgG/albumin and human plasma was demonstrated. Mercapto methyl imidazole (MMI) has shown the best adsorption of IgG in terms of binding capacity. No subclass discrimination was observed on all tested ligands except for mercapto methyl pyrimidine where the major IgG subclass adsorbed was IgG3. MMI gave an IgG binding capacity of 100 microg/cm2 of hollow fiber membrane surface area.

Isotypes and antigenic profiles of pemphigus foliaceus and pemphigus vulgaris autoantibodies.

PubMed

Hacker, Mary K; Janson, Marleen; Fairley, Janet A; Lin, Mong-Shang

2002-10-01

In this study we systematically characterized isotype profiles and antigenic and tissue specificity of antidesmoglein autoantibodies from patients with pemphigus foliaceus (PF) and pemphigus vulgaris (PV) using enzyme-linked immunoabsorbent assays (ELISA), indirect immunofluorescence (IIF) staining, and immunoblotting (IB). In PF, we found that IgG1 antidesmoglein-1 (Dsg1) reacts with a linear epitope(s) on the ectodomain of Dsg1, while its IgG4 counterpart recognizes a conformational epitope(s). These two subclasses of anti-Dsg1 are both capable of recognizing tissues from monkey esophagus and adult human skin, but IgG1 is not able to react with mouse skin, which may explain why this isotype of anti-Dsg1 failed to induce PF-like lesions in the passive transfer animal model. In mucosal PV patients, we found that both IgG1 and IgG4 only recognized monkey esophagus tissue by IIF, except in one patient, indicating that these antibodies react with a unique conformational epitope(s) that is present in mucosal but not skin tissue. In generalized PV, IgG1 anti-Dsg3 autoantibodies appeared to recognize a linear epitope(s) on the Dsg3 ectodomain. In contrast, IgG4 anti-Dsg3 antibodies recognized both linear and conformational epitopes on the Dsg3 molecule. Interestingly, the IgG1 anti-Dsg3 antibodies failed to react with human and mouse skin tissues, suggesting that this subclass of autoantibodies may not play an essential role in the development of PV suprabasilar lesions. In summary, we conclude that this study further elucidates the pathological mechanisms of PF and PV autoantibodies by revealing their distinct isotype and antigenic profiles. This information may help us to better understand the autoimmune mechanisms underlying the development of pemphigus.

Neutralization Takes Precedence Over IgG or IgA Isotype-related Functions in Mucosal HIV-1 Antibody-mediated Protection.

PubMed

Astronomo, Rena D; Santra, Sampa; Ballweber-Fleming, Lamar; Westerberg, Katharine G; Mach, Linh; Hensley-McBain, Tiffany; Sutherland, Laura; Mildenberg, Benjamin; Morton, Georgeanna; Yates, Nicole L; Mize, Gregory J; Pollara, Justin; Hladik, Florian; Ochsenbauer, Christina; Denny, Thomas N; Warrier, Ranjit; Rerks-Ngarm, Supachai; Pitisuttithum, Punnee; Nitayapan, Sorachai; Kaewkungwal, Jaranit; Ferrari, Guido; Shaw, George M; Xia, Shi-Mao; Liao, Hua-Xin; Montefiori, David C; Tomaras, Georgia D; Haynes, Barton F; McElrath, Juliana M

2016-12-01

HIV-1 infection occurs primarily through mucosal transmission. Application of biologically relevant mucosal models can advance understanding of the functional properties of antibodies that mediate HIV protection, thereby guiding antibody-based vaccine development. Here, we employed a human ex vivo vaginal HIV-1 infection model and a rhesus macaque in vivo intrarectal SHIV challenge model to probe the protective capacity of monoclonal broadly-neutralizing (bnAb) and non-neutralizing Abs (nnAbs) that were functionally modified by isotype switching. For human vaginal explants, we developed a replication-competent, secreted NanoLuc reporter virus system and showed that CD4 binding site bnAbs b12 IgG1 and CH31 IgG1 and IgA2 isoforms potently blocked HIV-1 JR-CSF and HIV-1 Bal26 infection. However, IgG1 and IgA nnAbs, either alone or together, did not inhibit infection despite the presence of FcR-expressing effector cells in the tissue. In macaques, the CH31 IgG1 and IgA2 isoforms infused before high-dose SHIV challenge were completely to partially protective, respectively, while nnAbs (CH54 IgG1 and CH38 mIgA2) were non-protective. Importantly, in both mucosal models IgG1 isotype bnAbs were more protective than the IgA2 isotypes, attributable in part to greater neutralization activity of the IgG1 variants. These findings underscore the importance of potent bnAb induction as a primary goal of HIV-1 vaccine development. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Specificity and Effector Functions of Human RSV-Specific IgG from Bovine Milk.

PubMed

den Hartog, Gerco; Jacobino, Shamir; Bont, Louis; Cox, Linda; Ulfman, Laurien H; Leusen, Jeanette H W; van Neerven, R J Joost

2014-01-01

Respiratory syncytial virus (RSV) infection is the second most important cause of death in the first year of life, and early RSV infections are associated with the development of asthma. Breastfeeding and serum IgG have been shown to protect against RSV infection. Yet, many infants depend on bovine milk-based nutrition, which at present lacks intact immunoglobulins. To investigate whether IgG purified from bovine milk (bIgG) can modulate immune responses against human RSV. ELISAs were performed to analyse binding of bIgG to human respiratory pathogens. bIgG or hRSV was coated to plates to assess dose-dependent binding of bIgG to human Fcγ receptors (FcγR) or bIgG-mediated binding of myeloid cells to hRSV respectively. S. Epidermidis and RSV were used to test bIgG-mediated binding and internalisation of pathogens by myeloid cells. Finally, the ability of bIgG to neutralise infection of HEp2 cells by hRSV was evaluated. bIgG recognised human RSV, influenza haemagglutinin and Haemophilus influenza. bIgG bound to FcγRII on neutrophils, monocytes and macrophages, but not to FcγRI and FcγRIII, and could bind simultaneously to hRSV and human FcγRII on neutrophils. In addition, human neutrophils and dendritic cells internalised pathogens that were opsonised with bIgG. Finally, bIgG could prevent infection of HEp2 cells by hRSV. The data presented here show that bIgG binds to hRSV and other human respiratory pathogens and induces effector functions through binding to human FcγRII on phagocytes. Thus bovine IgG may contribute to immune protection against RSV.

Serum IgG and IgE antibodies against mold-derived antigens in patients with symptoms of hypersensitivity.

PubMed

Makkonen, K; Viitala, K I; Parkkila, S; Niemelä, O

2001-03-01

Exposure to mold in water-damaged buildings has been suggested to be responsible for various health problems such as hypersensitivity and upper respiratory tract diseases. However, only little information is available on possible diagnostic tools for examining mold-associated health problems. We used recently developed immunofluorometric IgG and IgE assays (UniCAP) to examine serum IgG and IgE antibodies against mold-derived allergens from 70 mold-exposed individuals with (n = 55) or without (n = 15) symptoms of sensitization. Controls were healthy individuals (n = 31) without any history of such exposure. The IgG titers exceeded the upper normal limits of control individuals (mean +/- 2 S.D.) in 35% of symptomatic men and in 25% of women. The IgG titers were usually higher in women than in men (P < 0.05) showing no significant association with the severity of symptoms. During follow-up of eight mold-exposed subjects for 9-12 months the IgG titers remained relatively constant. Elevated anti-mold IgEs were found in six (11%) of the exposed subjects who were all symptomatic. Measurements of anti-mold IgGs may help to confirm exposure in patients with hypersensitivity symptoms and evidence of mold growth in living or working environment. Some exposed symptomatic patients present IgE-mediated responses. Combined measurements of IgGs and IgEs may prove to be of value in the comprehensive assessment and treatment of such patients.

Idiotypic specificities and cross-reactivities of rabbit antibodies to human antidextran.

PubMed

Outschoorn, I M

1979-10-01

Idiotypic antibodies were prepared by immunizing two groups of rabbits with dextran-antidextran specific precipitates and purified antidextran obtained subsequently from the same human donor. Half of the animals were made tolerant to pooled human IgG. Tests showed that sera from tolerant rabbits reacted better with the antidextran preparation used to immunize the other group of animals than with the antidextran that formed part of their immunogen. Non-tolerant animals did not recognize this serological difference. Sera from animals immunized with the antidextran preparation donated later reacted better with this material irrespective of their tolerance to human IgG.

Clearance and organ localization of particles and soluble complexes in mice with circulating complexes.

PubMed Central

Carter, S D; Brennan, F M; Grace, S A; Elson, C J

1984-01-01

The clearance and organ localization of a number of substances cleared by either Fc-dependent or -independent mechanisms was studied in normal mice and in mice with endogenously produced persistent circulating complexes. Clearance of covalent dimers of mouse IgG, chicken IgG and ovalbumin were no different between the two groups of mice. By contrast, hepatic and splenic uptake of dimeric mouse IgG (but not of chicken IgG or ovalbumin dimer) was impaired in the mice with persisting complexes. Surprisingly the rate of clearance of sheep red blood cells (SRBC) was increased in mice with persisting complexes as was hepatic uptake of polyvinyl pyrrolidone. It is suggested that the mononuclear phagocytes of mice with persistent circulating complexes are non-specifically stimulated while their ability to take up soluble complexes by Fc-dependent attachment is selectively impaired. PMID:6746002

A rapid, accurate and robust particle-based assay for the simultaneous screening of plasma samples for the presence of five different anti-cytokine autoantibodies.

PubMed

Guldager, Daniel Kring Rasmussen; von Stemann, Jakob Hjorth; Larsen, Rune; Bay, Jakob Thaning; Galle, Pia Søndergaard; Svenson, Morten; Ullum, Henrik; Hansen, Morten Bagge

2015-10-01

To establish and validate a rapid, cost-effective and accurate screening assay for the simultaneous testing of human naturally occurring anti-cytokine autoantibodies (c-aAb) targeting interleukin-1α (IL-1α), interleukin-6 (IL-6), interleukin-10 (IL-10), granulocyte-macrophage colony-stimulating factor (GM-CSF), and interferon α (IFNα). Because the c-aAbs can be transferred to patients through blood transfusion, the assay was used to assess c-aAb levels in a cohort of patients who were receiving blood transfusions and subsequently presented with or without febrile reactions. The microsphere-based Luminex platform was used. Recombinant forms of human IL-1α, IL-6, IL-10, GM-CSF, and IFNα were gently coupled to MAG-PLEX beads. Plasma IgG binding was measured with phycoerythrin (PE)-labeled secondary antibodies. Previously confirmed c-aAb positive and negative donor plasma samples and pooled normal immunoglobulin preparations were used to validate the assay. Plasma samples from 98 transfusion recipients, half of whom presented with febrile reactions, were tested by the assay. The assay detected specific and saturable immunoglobulin G (IgG) binding to each of the tested cytokines in previously confirmed c-aAb positive plasmas and in preparations of pooled normal immunoglobulin. Confirmed c-aAb negative plasmas gave no saturable binding. The detection limit of the cytokine autoantibodies was estimated to be between 1 pM and 10 pM. The recovery of confirmed cytokine autoantibodies quantities in the negative plasma samples ranged between 80% and 125%. The analytical intra- and inter-assay variations were 4% and 11%, respectively. Varying c-aAb levels were detectable in the transfusion recipients. There was no difference in c-aAb frequency between the patients with or without febrile transfusion reactions. The c-aAb level before and after the blood transfusions varied only slightly and in an irregular manner. This assay simultaneously detected up to five different c-aAbs in pooled human IgG and in plasma from individual blood donors, and it was deemed suitable for larger screenings. Based on confirmed antibody binding characteristics and the resultant reactivity in this multiplex assay, a classification of the c-aAb levels was suggested. The screening results of the recipients who received blood transfusions indicate that more studies are needed to clarify the role of antibodies, if any, in transfusion medicine and in high-dose immunoglobulin treatment. Copyright © 2015 Elsevier B.V. All rights reserved.

Enhanced Insight into the Autoimmune Component of Glaucoma: IgG Autoantibody Accumulation and Pro-Inflammatory Conditions in Human Glaucomatous Retina

PubMed Central

Gramlich, Oliver W.; Beck, Sabine; von Thun und Hohenstein-Blaul, Nadine; Boehm, Nils; Ziegler, Anika; Vetter, Jan M.; Pfeiffer, Norbert; Grus, Franz H.

2013-01-01

Background There is accumulating evidence that autoimmune components, such as autoantibodies and autoantibody depositions, play a role in the pathogenesis of neurodegenerative diseases like Alzheimeŕs disease or Multiple Sclerosis. Due to alterations of autoantibody patterns in sera and aqueous humor, an autoimmune component is also assumed in the pathogenesis of glaucoma, a common reason for irreversible blindness worldwide. So far there has been no convincing evidence that autoantibodies are accumulated in the retina of glaucoma patients and that the local immune homeostasis might be affected. Methods and Results Six human glaucomatous donor eyes and nine samples from donors with no recorded ocular disease were included. Antibody microarrays were used to examine the patterns of pro-inflammatory proteins and complement proteins. Analysis of TNF-α and interleukin levels revealed a slight up-regulation exclusively in the glaucomatous group, while complement protein levels were not altered. IgG autoantibody accumulations and/or cellular components were determined by immunohistology (n = 4 per group). A significantly reduced number of retinal ganglion cells was found in the glaucomatous group (healthy: 104±7 nuclei/mm, glaucoma: 67±9 nuclei/mm; p = 0.0007). Cell loss was accompanied by strong retinal IgG autoantibody accumulations, which were at least twice as high as in healthy subjects (healthy: 5.0±0.5 IgG deposits/100 cells, glaucoma: 9.4±1.9 IgG deposits/100 cells; p = 0.004). CD27+ cells and CD27+/IgG+ plasma cells were observed in all glaucomatous subjects, but not in controls. Conclusion This work provides serious evidence for the occurrence of IgG antibody deposition and plasma cells in human glaucomatous retina. Moreover, the results suggest that these IgG deposits occurred in a pro-inflammatory environment which seems to be maintained locally by immune-competent cells like microglia. Thereby, glaucoma features an immunological involvement comparable to other neurodegenerative diseases, but also shows a multifactorial pathomechanism, which diverges and might be linked to the specific nature of both eye and retina. PMID:23451242

Influence of IgG Subclass on Human Antimannan Antibody-Mediated Resistance to Hematogenously Disseminated Candidiasis in Mice

PubMed Central

Nishiya, Casey T.; Boxx, Gayle M.; Robison, Kerry; Itatani, Carol; Kozel, Thomas R.

2015-01-01

Candida albicans is a yeast-like pathogen and can cause life-threatening systemic candidiasis. Its cell surface is enriched with mannan that is resistant to complement activation. Previously, we developed the recombinant human IgG1 antimannan antibody M1g1. M1g1 was found to promote complement activation and phagocytosis and protect mice from systemic candidiasis. Here, we evaluate the influence of IgG subclass on antimannan antibody-mediated protection. Three IgG subclass variants of M1g1 were constructed: M1g2, M1g3, and M1g4. The IgG subclass identity for each variant was confirmed with DNA sequence and subclass-specific antibodies. These variants contain identical M1 Fabs and exhibited similar binding affinities for C. albicans yeast and purified mannan. Yeast cells and hyphae recovered from the kidney of antibody-treated mice with systemic candidiasis showed uniform binding of each variant, indicating constitutive expression of the M1 epitope and antibody opsonization in the kidney. All variants promoted deposition of both murine and human C3 onto the yeast cell surface, with M1g4 showing delayed activation, as determined by flow cytometry and immunofluorescence microscopy. M1g4-mediated complement activation was found to be associated with its M1 Fab that activates the alternative pathway in an Fc-independent manner. Treatment with each subclass variant extended the survival of mice with systemic candidiasis (P < 0.001). However, treatment with M1g1, M1g3, or M1g4, but not with M1g2, also reduced the kidney fungal burden (P < 0.001). Thus, the role of human antimannan antibody in host resistance to systemic candidiasis is influenced by its IgG subclass. PMID:26573736

Importance of neonatal FcR in regulating the serum half-life of therapeutic proteins containing the Fc domain of human IgG1: a comparative study of the affinity of monoclonal antibodies and Fc-fusion proteins to human neonatal FcR.

PubMed

Suzuki, Takuo; Ishii-Watabe, Akiko; Tada, Minoru; Kobayashi, Tetsu; Kanayasu-Toyoda, Toshie; Kawanishi, Toru; Yamaguchi, Teruhide

2010-02-15

The neonatal FcR (FcRn) binds to the Fc domain of IgG at acidic pH in the endosome and protects IgG from degradation, thereby contributing to the long serum half-life of IgG. To date, more than 20 mAb products and 5 Fc-fusion protein products have received marketing authorization approval in the United States, the European Union, or Japan. Many of these therapeutic proteins have the Fc domain of human IgG1; however, the serum half-lives differ in each protein. To elucidate the role of FcRn in the pharmacokinetics of Fc domain-containing therapeutic proteins, we evaluated the affinity of the clinically used human, humanized, chimeric, or mouse mAbs and Fc-fusion proteins to recombinant human FcRn by surface plasmon resonance analysis. The affinities of these therapeutic proteins to FcRn were found to be closely correlated with the serum half-lives reported from clinical studies, suggesting the important role of FcRn in regulating their serum half-lives. The relatively short serum half-life of Fc-fusion proteins was thought to arise from the low affinity to FcRn. The existence of some mAbs having high affinity to FcRn and a short serum half-life, however, suggested the involvement of other critical factor(s) in determining the serum half-life of such Abs. We further investigated the reason for the relatively low affinity of Fc-fusion proteins to FcRn and suggested the possibility that the receptor domain of Fc-fusion protein influences the structural environment of the FcRn binding region but not of the FcgammaRI binding region of the Fc domain.

HLA class I antibodies trigger increased adherence of monocytes to endothelial cells by eliciting an increase in endothelial P-selectin and, depending on subclass, by engaging FcγRs.

PubMed

Valenzuela, Nicole M; Mulder, Arend; Reed, Elaine F

2013-06-15

Ab-mediated rejection (AMR) of solid organ transplants is characterized by intragraft macrophages. It is incompletely understood how donor-specific Ab binding to graft endothelium promotes monocyte adhesion, and what, if any, contribution is made by the Fc region of the Ab. We investigated the mechanisms underlying monocyte recruitment by HLA class I (HLA I) Ab-activated endothelium. We used a panel of murine mAbs of different subclasses to crosslink HLA I on human aortic, venous, and microvascular endothelial cells and measured the binding of human monocytic cell lines and peripheral blood monocytes. Both anti-HLA I murine (m)IgG1 and mIgG2a induced endothelial P-selectin, which was required for monocyte adhesion to endothelium irrespective of subclass. mIgG2a but not mIgG1 could bind human FcγRs. Accordingly, HLA I mIgG2a but not mIgG1 treatment of endothelial cells significantly augmented recruitment, predominantly through FcγRI, and, to a lesser extent, FcγRIIa. Moreover, HLA I mIgG2a promoted firm adhesion of monocytes to ICAM-1 through Mac-1, which may explain the prominence of monocytes during AMR. We confirmed these observations using human HLA allele-specific mAbs and IgG purified from transplant patient sera. HLA I Abs universally elicit endothelial exocytosis leading to monocyte adherence, implying that P-selectin is a putative therapeutic target to prevent macrophage infiltration during AMR. Importantly, the subclass of donor-specific Ab may influence its pathogenesis. These results imply that human IgG1 and human IgG3 should have a greater capacity to trigger monocyte infiltration into the graft than IgG2 or IgG4 due to enhancement by FcγR interactions.

Analytical FcRn affinity chromatography for functional characterization of monoclonal antibodies

PubMed Central

Schlothauer, Tilman; Rueger, Petra; Stracke, Jan Olaf; Hertenberger, Hubert; Fingas, Felix; Kling, Lothar; Emrich, Thomas; Drabner, Georg; Seeber, Stefan; Auer, Johannes; Koch, Stefan; Papadimitriou, Apollon

2013-01-01

The neonatal Fc receptor (FcRn) is important for the metabolic fate of IgG antibodies in vivo. Analysis of the interaction between FcRn and IgG in vitro might provide insight into the structural and functional integrity of therapeutic IgG that may affect pharmacokinetics (PK) in vivo. We developed a standardized pH gradient FcRn affinity liquid chromatography method with conditions closely resembling the physiological mechanism of interaction between IgG and FcRn. This method allows the separation of molecular IgG isoforms, degradation products and engineered molecules based on their affinity to FcRn. Human FcRn was immobilized on the column and a linear pH gradient from pH 5.5 to 8.8 was applied. FcRn chromatography was used in comparison to surface plasmon resonance to characterize different monoclonal IgG preparations, e.g., oxidized or aggregated species. Wild-type and engineered IgGs were compared in vitro by FcRn chromatography and in vivo by PK studies in huFcRn transgenic mice. Analytical FcRn chromatography allows differentiation of IgG samples and variants by peak pattern and retention time profile. The method can distinguish: 1) IgGs with different Fabs, 2) oxidized from native IgG, 3) aggregates from monomer and 4) antibodies with mutations in the Fc part from wild-type IgGs. Changes in the FcRn chromatographic behavior of mutant IgGs relative to the wild-type IgG correlate to changes in the PK profile in the FcRn transgenic mice. These results demonstrate that FcRn affinity chromatography is a useful new method for the assessment of IgG integrity. PMID:23765230

Anti-pituitary antibodies against corticotrophs in IgG4-related hypophysitis.

PubMed

Iwata, Naoko; Iwama, Shintaro; Sugimura, Yoshihisa; Yasuda, Yoshinori; Nakashima, Kohtaro; Takeuchi, Seiji; Hagiwara, Daisuke; Ito, Yoshihiro; Suga, Hidetaka; Goto, Motomitsu; Banno, Ryoichi; Caturegli, Patrizio; Koike, Teruhiko; Oshida, Yoshiharu; Arima, Hiroshi

2017-06-01

IgG4-related disease is a systemic inflammatory disease characterized by infiltration of IgG4-positive plasma cells into multiple organs, including the pituitary gland. Autoimmunity is thought to be involved in the pathogenesis of IgG4-related disease. The diagnosis of IgG4-related hypophysitis (IgG4-RH) is difficult because its clinical features, such as pituitary swelling and hypopituitarism, are similar to those of other pituitary diseases, including lymphocytic hypophysitis and sellar/suprasellar tumors. The presence and significance of anti-pituitary antibodies (APA) in IgG4-RH is unclear. In this case-control study, we used single indirect immunofluorescence on human pituitary substrates to assess the prevalence of serum APA in 17 patients with IgG4-RH, 8 control patients with other pituitary diseases (lymphocytic infundibulo-neurohypophysitis, 3; craniopharyngioma, 2; germinoma, 3), and 9 healthy subjects. We further analyzed the endocrine cells targeted by the antibodies using double indirect immunofluorescence. APA were found in 5 of 17 patients with IgG4-RH (29%), and in none of the pituitary controls or healthy subjects. The endocrine cells targeted by the antibodies in the 5 IgG4-RH cases were exclusively corticotrophs. Antibodies were of the IgG1 subclass, rather than IgG4, in all 5 cases, suggesting that IgG4 is not directly involved in the pathogenesis. Finally, antibodies recognized pro-opiomelanocortin in 2 of the cases. Our study suggests that autoimmunity is involved in the pathogenesis of IgG4-RH and that corticotrophs are the main antigenic target, highlighting a possible new diagnostic marker for this condition.

Serum killing of Ureaplasma parvum shows serovar-determined susceptibility for normal individuals and common variable immuno-deficiency patients.

PubMed

Beeton, Michael L; Daha, Mohamed R; El-Shanawany, Tariq; Jolles, Stephen R; Kotecha, Sailesh; Spiller, O Brad

2012-02-01

Many Gram-negative bacteria, unlike Gram-positive, are directly lysed by complement. Ureaplasma can cause septic arthritis and meningitis in immunocompromised individuals and induce premature birth. Ureaplasma has no cell wall, cannot be Gram-stain classified and its serum susceptibility is unknown. Survival of Ureaplasma serovars (SV) 1, 3, 6 and 14 (collectively Ureaplasma parvum) were measured following incubation with normal or immunoglobulin-deficient patient serum (relative to heat-inactivated controls). Blocking monoclonal anti-C1q antibody and depletion of calcium, immunoglobulins, or lectins were used to determine the complement pathway responsible for killing. Eighty-three percent of normal sera killed SV1, 67% killed SV6 and 25% killed SV14; greater killing correlating to strong immunoblot identification of anti-Ureaplasma antibodies; killing was abrogated following ProteinA removal of IgG1. All normal sera killed SV3 in a C1q-dependent fashion, irrespective of immunoblot identification of anti-Ureaplasma antibodies; SV3 killing was unaffected by total IgG removal by ProteinG, where complement activity was retained. Only one of four common variable immunodeficient (CVID) patient sera failed to kill SV3, despite profound IgM and IgG deficiency for all; however, killing of SV3 and SV1 was restored with therapeutic intravenous immunoglobulin therapy. Only the classical complement pathway mediated Ureaplasma-cidal activity, sometimes in the absence of observable immunoblot reactive bands. Copyright © 2011 Elsevier GmbH. All rights reserved.

Standardization of Assays That Detect Anti-Rubella Virus IgG Antibodies

PubMed Central

Grangeot-Keros, Liliane; Vauloup-Fellous, Christelle

2015-01-01

SUMMARY Rubella virus usually causes a mild infection in humans but can cause congenital rubella syndrome (CRS). Vaccination programs have significantly decreased primary rubella virus infection and CRS; however, vaccinated individuals usually have lower levels of rubella virus IgG than those with natural infections. Rubella virus IgG is quantified with enzyme immunoassays that have been calibrated against the World Health Organization (WHO) international standard and report results in international units per milliliter. It is recognized that the results reported by these assays are not standardized. This investigation into the reasons for the lack of standardization found that the current WHO international standard (RUB-1-94) fails by three key metrological principles. The standard is not a pure analyte but is composed of pooled human immunoglobulin. It was not calibrated by certified reference methods; rather, superseded tests were used. Finally, no measurement uncertainty estimations have been provided. There is an analytical and clinical consequence to the lack of standardization of rubella virus IgG assays, which leads to misinterpretation of results. The current approach to standardization of rubella virus IgG assays has not achieved the desired results. A new approach is required. PMID:26607813

Neurofascin-155 IgG4 in chronic inflammatory demyelinating polyneuropathy

PubMed Central

Devaux, Jérôme J.; Miura, Yumako; Fukami, Yuki; Inoue, Takayuki; Manso, Constance; Belghazi, Maya; Sekiguchi, Kenji; Kokubun, Norito; Ichikawa, Hiroo; Wong, Anna Hiu Yi

2016-01-01

Objective: We report the clinical and serologic features of Japanese patients with chronic inflammatory demyelinating polyneuropathy (CIDP) displaying anti-neurofascin-155 (NF155) immunoglobulin G4 (IgG4) antibodies. Methods: In sera from 533 patients with CIDP, anti-NF155 IgG4 antibodies were detected by ELISA. Binding of IgG antibodies to central and peripheral nerves was tested. Results: Anti-NF155 IgG4 antibodies were identified in 38 patients (7%) with CIDP, but not in disease controls or normal participants. These patients were younger at onset as compared to 100 anti-NF155–negative patients with CIDP. Twenty-eight patients (74%) presented with sensory ataxia, 16 (42%) showed tremor, 5 (13%) presented with cerebellar ataxia associated with nystagmus, 3 (8%) had demyelinating lesions in the CNS, and 20 of 25 (80%) had poor response to IV immunoglobulin. The clinical features of the antibody-positive patients were statistically more frequent as compared to negative patients with CIDP (n = 100). Anti-NF155 IgG antibodies targeted similarly central and peripheral paranodes. Conclusion: Anti-NF155 IgG4 antibodies were associated with a subgroup of patients with CIDP showing a younger age at onset, ataxia, tremor, CNS demyelination, and a poor response to IV immunoglobulin. The autoantibodies may serve as a biomarker to improve patients' diagnosis and guide treatments. PMID:26843559

Neurofascin-155 IgG4 in chronic inflammatory demyelinating polyneuropathy.

PubMed

Devaux, Jérôme J; Miura, Yumako; Fukami, Yuki; Inoue, Takayuki; Manso, Constance; Belghazi, Maya; Sekiguchi, Kenji; Kokubun, Norito; Ichikawa, Hiroo; Wong, Anna Hiu Yi; Yuki, Nobuhiro

2016-03-01

We report the clinical and serologic features of Japanese patients with chronic inflammatory demyelinating polyneuropathy (CIDP) displaying anti-neurofascin-155 (NF155) immunoglobulin G4 (IgG4) antibodies. In sera from 533 patients with CIDP, anti-NF155 IgG4 antibodies were detected by ELISA. Binding of IgG antibodies to central and peripheral nerves was tested. Anti-NF155 IgG4 antibodies were identified in 38 patients (7%) with CIDP, but not in disease controls or normal participants. These patients were younger at onset as compared to 100 anti-NF155-negative patients with CIDP. Twenty-eight patients (74%) presented with sensory ataxia, 16 (42%) showed tremor, 5 (13%) presented with cerebellar ataxia associated with nystagmus, 3 (8%) had demyelinating lesions in the CNS, and 20 of 25 (80%) had poor response to IV immunoglobulin. The clinical features of the antibody-positive patients were statistically more frequent as compared to negative patients with CIDP (n = 100). Anti-NF155 IgG antibodies targeted similarly central and peripheral paranodes. Anti-NF155 IgG4 antibodies were associated with a subgroup of patients with CIDP showing a younger age at onset, ataxia, tremor, CNS demyelination, and a poor response to IV immunoglobulin. The autoantibodies may serve as a biomarker to improve patients' diagnosis and guide treatments. © 2016 American Academy of Neurology.

Development and Evaluation of a Sensitive and Specific Assay for Diagnosis of Human Toxocariasis by Use of Three Recombinant Antigens (TES-26, TES-30USM, and TES-120)▿

PubMed Central

Mohamad, Suharni; Azmi, Norhaida Che; Noordin, Rahmah

2009-01-01

Diagnosis of human toxocariasis currently relies on serologic tests that use Toxocara excretory-secretory (TES) antigen to detect immunoglobulin G (IgG) antibodies to the larvae. In general, however, these assays do not have adequate specificity for use in countries in which other soil-transmitted helminths are endemic. The use of recombinant antigens in these assays, however, is promising for improving the specificity of the diagnosis of toxocariasis. Toward this goal, we developed an IgG4 enzyme-linked immunosorbent assay (ELISA) involving three recombinant antigens: rTES-30USM (previously produced), rTES-26, and rTES-120. The latter two antigens were produced by reverse transcription-PCR cloning; subcloned into glutathione S-transferase (GST)-tagged and His-tagged prokaryotic expression vectors, respectively; and expressed in Escherichia coli. The recombinant proteins were subsequently purified by affinity chromatography using GST and His-Trap resins. The diagnostic potential of each purified recombinant antigen was tested with various immunoglobulin classes (IgG, IgM, and IgE) and IgG subclasses. The IgG4 ELISA was determined to have the highest specificity and was further evaluated using a panel of serum samples. The rTES-26 IgG4 ELISA showed 80.0% (24/30 samples positive) sensitivity, and both the rTES-30USM IgG4 ELISA and rTES-120 IgG4 ELISA had 93.0% (28/30) sensitivity. Combined use of rTES-120 and rTES-30 IgG4 ELISA for the diagnosis of toxocariasis provided 100% sensitivity. The specificities of rTES-26, rTES-30USM, and rTES-120 antigens were 96.2%, 93.9%, and 92.0%, respectively. These results indicate that the development of a diagnostic test using the three recombinant antigens will allow for more-accurate detection of toxocariasis. PMID:19369434

Development and evaluation of a sensitive and specific assay for diagnosis of human toxocariasis by use of three recombinant antigens (TES-26, TES-30USM, and TES-120).

PubMed

Mohamad, Suharni; Azmi, Norhaida Che; Noordin, Rahmah

2009-06-01

Diagnosis of human toxocariasis currently relies on serologic tests that use Toxocara excretory-secretory (TES) antigen to detect immunoglobulin G (IgG) antibodies to the larvae. In general, however, these assays do not have adequate specificity for use in countries in which other soil-transmitted helminths are endemic. The use of recombinant antigens in these assays, however, is promising for improving the specificity of the diagnosis of toxocariasis. Toward this goal, we developed an IgG4 enzyme-linked immunosorbent assay (ELISA) involving three recombinant antigens: rTES-30USM (previously produced), rTES-26, and rTES-120. The latter two antigens were produced by reverse transcription-PCR cloning; subcloned into glutathione S-transferase (GST)-tagged and His-tagged prokaryotic expression vectors, respectively; and expressed in Escherichia coli. The recombinant proteins were subsequently purified by affinity chromatography using GST and His-Trap resins. The diagnostic potential of each purified recombinant antigen was tested with various immunoglobulin classes (IgG, IgM, and IgE) and IgG subclasses. The IgG4 ELISA was determined to have the highest specificity and was further evaluated using a panel of serum samples. The rTES-26 IgG4 ELISA showed 80.0% (24/30 samples positive) sensitivity, and both the rTES-30USM IgG4 ELISA and rTES-120 IgG4 ELISA had 93.0% (28/30) sensitivity. Combined use of rTES-120 and rTES-30 IgG4 ELISA for the diagnosis of toxocariasis provided 100% sensitivity. The specificities of rTES-26, rTES-30USM, and rTES-120 antigens were 96.2%, 93.9%, and 92.0%, respectively. These results indicate that the development of a diagnostic test using the three recombinant antigens will allow for more-accurate detection of toxocariasis.

Detection of Human Toxoplasma-Specific Immunoglobulins A, M, and G with a Recombinant Toxoplasma gondii Rop2 Protein

PubMed Central

Martin, Valentina; Arcavi, Miriam; Santillan, Graciela; Amendoeira, Maria Regina R.; De Souza Neves, Elizabeth; Griemberg, Gloria; Guarnera, Eduardo; Garberi, Juan C.; Angel, Sergio O.

1998-01-01

The Toxoplasma gondii rhoptry protein Rop2 was expressed in Escherichia coli as a fusion protein containing 44 kDa of the 55-kDa mature Rop2, supplied with six histidyl residues at the N-terminal end (Rop2196–561). Humoral response during Toxoplasma infection of humans was analyzed by immunoglobulin G (IgG), IgA, and IgM enzyme-linked immunosorbent assay with Rop2196–561 as the antigen substrate. The analyzed sera were divided according to T. gondii-specific serological tests (IgG, IgA, or IgM indirect immunofluorescence and IgA or IgM immunosorbent agglutination assay) as group A (IgG+ IgA− IgM−; n = 35), group B (IgG+ IgA+ IgM+; n = 21), group C (IgG+ IgA+ IgM−; n = 5), and group D (IgG+ IgA− IgM+; n = 16). Twenty-six T. gondii-seronegative sera from individuals with other infections were also included (group E). Anti-Rop2 IgG antibodies were detected in 82.8% of group A sera and in 97.6% of the sera with acute-phase marker immunoglobulins (groups B, C, and D). The percentage of IgA antibody reactivity against Rop2196–561 was 17.1% in group A, 50% in group D, and 80.8% in groups B and C. The percentage of IgM antibody reactivity was 0% in groups A and C and 62% in groups B and D. Sera from group E failed to show IgA, IgM, or IgG antibody reactivity. Since T. gondii Rop2 elicits a strong humoral response from an early stage of infection, it is suggested that recombinant Rop2196–561 would be suitable for use in diagnostic systems, in combination with other T. gondii antigens, to detect specific IgG, IgA, and IgM antibodies. PMID:9729528

Molecular Dynamics Simulation of the Crystallizable Fragment of IgG1—Insights for the Design of Fcabs

PubMed Central

Lai, Balder; Hasenhindl, Christoph; Obinger, Christian; Oostenbrink, Chris

2014-01-01

An interesting format in the development of therapeutic monoclonal antibodies uses the crystallizable fragment of IgG1 as starting scaffold. Engineering of its structural loops allows generation of an antigen binding site. However, this might impair the molecule’s conformational stability, which can be overcome by introducing stabilizing point mutations in the CH3 domains. These point mutations often affect the stability and unfolding behavior of both the CH2 and CH3 domains. In order to understand this cross-talk, molecular dynamics simulations of the domains of the Fc fragment of human IgG1 are reported. The structure of human IgG1-Fc obtained from X-ray crystallography is used as a starting point for simulations of the wild-type protein at two different pH values. The stabilizing effect of a single point mutation in the CH3 domain as well as the impact of the hinge region and the glycan tree structure connected to the CH2 domains is investigated. Regions of high local flexibility were identified as potential sites for engineering antigen binding sites. Obtained data are discussed with respect to the available X-ray structure of IgG1-Fc, directed evolution approaches that screen for stability and use of the scaffold IgG1-Fc in the design of antigen binding Fc proteins. PMID:24451126

Studies on glycoxidatively modified human IgG: Implications in immuno-pathology of type 2 diabetes mellitus.

PubMed

Islam, Sidra; Moinuddin; Mir, Abdul Rouf; Arfat, Mir Yasir; Alam, Khursheed; Ali, Asif

2017-11-01

Structural rearrangements and condensations of proteins under hyperglycemic stress have been implicated in various pathological disorders. This study aims to probe the role of methylglyoxal (MG) modified human immunoglobulin G (MG-IgG) in immuno-pathology of type 2 diabetes mellitus (T2DM). MG was found to perturb the structural integrity of IgG, affect its aromatic micro-environment and cause the generation of advanced glycation end products (AGEs) and aggregate adducts. It liberated the hydrophobic pockets of the protein, reduced its β pleated sheet structure and affected its tertiary conformation. Transition from β sheet to α helix and random coil was also observed in IgG upon modification by MG. It acted with strong oxidative potential and caused oligomerisation and disordered or amorphous type aggregation in the modified protein. Modified IgG had a cytotoxic and genotoxic impact. The MG modified IgG presented novel antigenic determinants that lead to an aggressive immune response. The antibodies had high affinity towards the immunogen. Auto-antibodies derived from T2DM patients exhibited strong affinity towards the modified IgG in comparison to the unmodified protein. Specificity of serum antibodies from T2DM patients was further confirmed by competitive-inhibition ELISA. The potential role of MG-IgG in the immunopathogenesis of T2DM has been discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

A new human IgG avidity test, using mixtures of recombinant antigens (rROP1, rSAG2, rGRA6), for the diagnosis of difficult-to-identify phases of toxoplasmosis.

PubMed

Drapała, Dorota; Holec-Gąsior, Lucyna; Kur, Józef; Ferra, Bartłomiej; Hiszczyńska-Sawicka, Elżbieta; Lautenbach, Dariusz

2014-07-01

The preliminary diagnostic utility of two mixtures of Toxoplasma gondii recombinant antigens (rROP1+rSAG2 and rROP1+rGRA6) in IgG ELISA and IgG avidity test has been evaluated. A total of 173 serum samples from patients with toxoplasmosis and seronegative people were examined. The sensitivity of IgG ELISA for rROP1+rSAG2 and rROP1+rGRA6 was 91.1% and 76.7%, respectively, while the reactivity for sera from patients where acute toxoplasmosis was suspected was higher, at 100% and 95.4%, respectively, than for people with chronic infection, at 88.2% and 70.6%. In this study a different trend in avidity maturation of IgG antibodies for two mixtures of proteins in comparison with native antigen was observed. The results suggest that a new IgG avidity test using the mixtures of recombinant antigens may be useful for the diagnosis of difficult-to-identify phases of toxoplasmosis. For this reason, selected mixtures after the additional tests on groups of sera with well-defined dates of infection could be used as a better alternative to the native antigens of the parasite in the serodiagnosis of human T. gondii infection. Copyright © 2014 Elsevier Inc. All rights reserved.

The Neonatal Fc Receptor (FcRn) Enhances Human Immunodeficiency Virus Type 1 (HIV-1) Transcytosis across Epithelial Cells

PubMed Central

Gupta, Sandeep; Gach, Johannes S.; Becerra, Juan C.; Phan, Tran B.; Pudney, Jeffrey; Moldoveanu, Zina; Joseph, Sarah B.; Landucci, Gary; Supnet, Medalyn Jude; Ping, Li-Hua; Corti, Davide; Moldt, Brian; Hel, Zdenek; Lanzavecchia, Antonio; Ruprecht, Ruth M.; Burton, Dennis R.; Mestecky, Jiri; Anderson, Deborah J.; Forthal, Donald N.

2013-01-01

The mechanisms by which human immunodeficiency virus type 1 (HIV-1) crosses mucosal surfaces to establish infection are unknown. Acidic genital secretions of HIV-1-infected women contain HIV-1 likely coated by antibody. We found that the combination of acidic pH and Env-specific IgG, including that from cervicovaginal and seminal fluids of HIV-1-infected individuals, augmented transcytosis across epithelial cells as much as 20-fold compared with Env-specific IgG at neutral pH or non-specific IgG at either pH. Enhanced transcytosis was observed with clinical HIV-1 isolates, including transmitted/founder strains, and was eliminated in Fc neonatal receptor (FcRn)-knockdown epithelial cells. Non-neutralizing antibodies allowed similar or less transcytosis than neutralizing antibodies. However, the ratio of total:infectious virus was higher for neutralizing antibodies, indicating that they allowed transcytosis while blocking infectivity of transcytosed virus. Immunocytochemistry revealed abundant FcRn expression in columnar epithelia lining the human endocervix and penile urethra. Acidity and Env-specific IgG enhance transcytosis of virus across epithelial cells via FcRn and could facilitate translocation of virus to susceptible target cells following sexual exposure. PMID:24278022

Elevated immunoglobulin G antibodies to the proline-rich amino-terminal region of Epstein-Barr virus nuclear antigen-2 in sera from patients with systemic connective tissue diseases and from a subgroup of Sjögren's syndrome patients with pulmonary involvements.

PubMed

Yamazaki, M; Kitamura, R; Kusano, S; Eda, H; Sato, S; Okawa-Takatsuji, M; Aotsuka, S; Yanagi, K

2005-03-01

Associations of Epstein-Barr virus (EBV) and autoimmune diseases have been hypothesized. We have analysed IgG antibodies to EBV nuclear antigen (EBNA)-2 in sera from Japanese patients with autoimmune systemic connective tissue diseases (CTD), exemplified by systemic lupus erythematosus (SLE), primary Sjogren's syndrome (SS), rheumatoid arthritis (RA), systemic sclerosis (SSc) and secondary SS (classical CTDs complicated with SS). An enzyme-linked immunosorbent assay (ELISA) which uses glutathione-S-transferase polypeptides fused to EBV nuclear antigen (EBNA)-2 and EBNA-1 was developed. Ratios of IgG antibody reactivity to whole IgG concentrations of sera were calculated to normalize EBNA-2 and EBNA-1 antibody levels to the hypergammaglobulinaemia that occurs in CTD. The ELISA optical density OD(450) readings of IgG antibodies to both the amino-terminal aa 1-116 of EBNA-2 and carboxyl-terminal aa 451-641 of EBNA-1 were elevated significantly in patients with SLE, primary SS, RA, SSc and secondary SS when compared to EBNA-1. The OD readings were divided by serum IgG concentrations to normalize for the hypergammaglobulinaemia. The specific levels of IgG antibodies to the amino-terminal region of EBNA-2 were elevated in patients with SLE, primary SS or RA, as well as those with secondary SS complicated with SLE or RA. The EBNA-2 amino-terminal region contains a polyproline tract and a proline-rich sequence and has considerable amino acid sequence homology with many cellular proline-rich proteins. High ratios of EBNA-2 aa 1-116 to EBNA-1 aa 451-641 IgG antibody levels which probably suggest reactivation of EBV latent infection were associated significantly with pulmonary involvement in SS patients. These results are consistent with the hypothesis that the sequence similarity between the amino-terminal region of EBNA-2 and proline-rich cellular proteins is associated with pathogenesis in a subpopulation of CTD patients, possibly by the molecular mimicry-epitope shift mechanism.

Regulation of hippocampal synaptic plasticity by the tyrosine kinase receptor, REK7/EphA5, and its ligand, AL-1/Ephrin-A5.

PubMed

Gao, W Q; Shinsky, N; Armanini, M P; Moran, P; Zheng, J L; Mendoza-Ramirez, J L; Phillips, H S; Winslow, J W; Caras, I W

1998-08-01

The Eph-related tyrosine kinase receptor, REK7/EphA5, mediates the effects of AL-1/Ephrin-A5 and related ligands and is involved in the guidance of retinal, cortical, and hippocampal axons during development. The continued expression of REK7/EphA5 in the adult brain, in particular in areas associated with a high degree of synaptic plasticity such as the hippocampus, raises the question of its function in the mature nervous system. In this report we examined the role of REK7/EphA5 in synaptic remodeling by asking if agents that either block or activate REK7/EphA5 affect synaptic strength in hippocampal slices from adult mouse brain. We show that a REK7/EphA5 antagonist, soluble REK7/EphA5-IgG, impairs the induction of long-term potentiation (LTP) without affecting other synaptic parameters such as normal synaptic transmission or paired-pulse facilitation. In contrast, perfusion with AL-1/Ephrin-A5-IgG, an activator of REK7/EphA5, induces a sustained increase in normal synaptic transmission that partially mimics LTP. The sustained elevation of normal synaptic transmission could be attributable to a long-lasting binding of the AL-1/Ephrin-A5-IgG to the endogenous REK7/EphA5 receptor, as revealed by immunohistochemistry. Furthermore, maximal electrical induction of LTP occludes the potentiating effects of subsequent treatment with AL-1/Ephrin-A5-IgG. Taken together these results implicate REK7/EphA5 in the regulation of synaptic plasticity in the mature hippocampus and suggest that REK7/EphA5 activation is recruited in the LTP induced by tetanization. Copyright 1998 Academic Press.

Effect of Holder pasteurization on macronutrients and immunoglobulin profile of pooled donor human milk.

PubMed

Adhisivam, B; Vishnu Bhat, B; Rao, Krishna; Kingsley, S M; Plakkal, Nishad; Palanivel, C

2018-03-27

The objective of this study was to study the effect of Holder pasteurization on macronutrients and immunoglobulin profile of pooled donor human milk. This descriptive study was conducted in a Human Milk Bank of a tertiary care teaching institute in south India. Thirty random paired pooled donor human milk samples (before and after pasteurization) were analyzed for macronutrients (protein, fat, carbohydrates) using infrared spectroscopy. Similarly, immunoglobulin profile (IgA and IgG) before and after pasteurization was quantified using ELISA. The mean values of protein, fat, and carbohydrates in pooled donor milk pre-pasteurization were 1.6, 3.6, and 6.1 g/dl compared with post-pasteurization values 1.4, 2.7, and 5.9 g/dl, respectively. Pasteurization reduced protein, fat, and energy content of pooled donor milk by 12.5%, 25%, and 16%, respectively. However, carbohydrates were not significantly reduced. Pasteurization decreased IgA by 30% and IgG by 60%. Holder pasteurization of pooled donor human milk decreases protein, fat, and energy content and also reduces the levels of IgA and IgG.

Association of IgG co-deposition with serum levels of galactose-deficient IgA1 in pediatric IgA nephropathy

PubMed Central

Eison, T. Matthew; Hastings, M. Colleen; Moldoveanu, Zina; Sanders, John T.; Gaber, Lillian; Walker, Patrick D.; Lau, Keith K; Julian, Bruce A.; Novak, Jan; Wyatt, Robert J.

2012-01-01

Objective: To determine whether the absence of mesangial IgG deposits is associated with the absence of elevated blood levels of galactose-deficient IgA1 (Gd-IgA1) in pediatric patients with IgA nephropathy (IgAN). Design and methods: Serum Gd-IgA1 levels were determined by ELISA using an N-acetylgalactosamine-specific lectin from Helix aspersa. Levels of Gd-IgA1 above the 90th percentile for healthy pediatric controls were considered to be elevated. Renal biopsy samples were examined by immunofluorescence for presence and intensity of staining for IgA, IgG, IgM, C3 and C1q and by light microscopy for histological changes. Findings were graded by a single pathologist (L. Gaber) at UTHSC until 2007 and by NephropathTM (Little Rock, AR, USA) thereafter. Staining for the mesangial deposits was considered negative when intensity was trace or less, and positive at greater intensity. Fisher’s exact-test was used to determine significance of 2 × 2 tables. Results: Serum samples were obtained from 30 patients with IgAN diagnosed before age 18 years. Male : female ratio was 2.3 : 1. Twenty were Caucasian and 10 were African-American. Blood was obtained within 3 months of biopsy (incident cases) for 12, while 18 provided blood > 3 months after biopsy (prevalent cases). Serum Gd-IgA1 level was elevated in 23 (77%) of cases and 20 (67%) had a biopsy positive for IgG. Of those 20 patients, 18 (90%) had an elevated serum Gd-IgA1 level, whereas 5 (50%) of patients with biopsies without IgG had a normal serum Gd-IgA1 level (p = 0.026). Summary: In this small study we found a weak association between the absence of IgG in the biopsy and normal serum Gd-IgA1 level. PMID:23006340

High quality human immunoglobulin G purified from Cohn fractions by liquid chromatography.

PubMed

Tanaka, K; Sawatani, E; Dias, G A; Shigueoka, E M; Campos, T C; Nakao, H C; Arashiro, F

2000-01-01

In order to obtain intravenous immunoglobulin G (iv IgG) of high quality from F-I+II+III or F-II+III pastes prepared by the Cohn method, we developed a chromatography process using ion exchange gels, Q-Sepharose FF and CM-Sepharose FF, and Sephacryl S-300 gel filtration. Viral inactivation was performed by incubating the preparation with pepsin at pH 4.0 at 35 degrees C for 18 h. The characteristics of 28 batches produced by us were: yield 4.3 +/- 0.2 g/l plasma, i.e., a recovery of 39.1 +/- 1.8%; IgG subclasses distribution: IgG1 = 58.4%, IgG2 = 34.8%, IgG3 = 4.5% and IgG4 = 2. 3%; IgG size distribution was 98.4% monomers, 1.2% dimers and 0.4% polymers and protein aggregates; anticomplement activity was less than 0.5 CH50/mg IgG, and prekallikrein activator activity (PKA) was less than 5 IU/ml. These characteristics satisfied the requirements of the European Pharmacopoea edition, and the regulations of the Brazilian Health Ministry (M.S. Portaria No. 2, 30/10/1998).

A set of recombinant antigens from Echinococcus granulosus with potential for use in the immunodiagnosis of human cystic hydatid disease

PubMed Central

VIRGINIO, V G; HERNÁNDEZ, A; ROTT, M B; MONTEIRO, K M; ZANDONAI, A F; NIETO, A; ZAHA, A; FERREIRA, H B

2003-01-01

Several recombinant clones expressing antigens from Echinococcus granulosus were isolated previously from a parasite cDNA library using cystic hydatid disease (CHD) patients’ sera or rabbit hyperimmune antiserum against a lipoproteic fraction from bovine cyst fluid. Six of these antigens were expressed in Escherichia coli and the purified recombinant proteins were tested in enzyme-linked immunosorbent assay (ELISA) for specific IgG with a panel of sera from patients with surgically confirmed (n = 58) or immunologically diagnosed (n = 71) CHD. Sera from clinically normal individuals (n = 203) and sera from individuals with other helminthic infections (n = 65) were assayed for the assessment of specificity. A cut-off value was determined by receiver-operating-characteristic plots for each antigen. A recombinant antigen B subunit (AgB8/2) presented the highest sensitivity (93·1%), considering the group of sera from patients with CHD surgically confirmed, and specificity (99·5%) and is proposed as the basis for an immunodiagnostic test. The other recombinant antigens tested presented sensitivities between 58·6% and 89·7%, and three of them were considered of complementary value. In subclass-specific ELISA, different IgG isotypes showed dominance in the response for each of the recombinant antigens. There was a clear predominance of IgG4 response for all antigens tested, indicating that this would be the subclass of choice to be assessed for these recombinant proteins. PMID:12699422

Modulation of thymus-leukemia antigens on mouse leukemia cells induced by IgG, but not IgM, antibody.

PubMed

Stackpole, C W

1980-04-01

Exposure of mouse leukemia cells bearing thymus-leukemia (TL) surface antigens to whole TL alloantiserum has previously been shown to desensitize the cells to subsequent lysis by guinea pig complement (C) and fresh antiserum (antigenic modulation) and to correlate with the ability of cells to escape immune destruction in mice immunized against TL antigens. Tested in vitro, IgG of TL.1,2,3,5 antiserum modulated RADA1 leukemia cells (TL.1,2,3,5) completely within 2 hours at 37 degrees C when fully sensitizing amounts were used, with normal mouse serum as a source of C3. Similar results were obtained with IgG1, IgG2a, and IgG2b fractions of TL antiserum. An IgG2a monoclonal TL.3 antibody also completely modulated TL.3 antigens and partially modulated all antigens detected with TL.1,2,3,5 antiserum. IgM anti-TL.1,2,3,5 failed to modulate RADA1 cells even after 6 hours in vitro when fully sensitizing amounts of antibody were used. An IgM monoclonal TL antibody also failed to induce modulation. Modulation did occur on cells incubated with fully sensitizing amounts of IgG and IgM TL.1,2,3,5 antibody simultaneously, and nearly all cell-bound immunoglobulins were IgG. In mice passively immunized with IgG TL antibody, RADA1 cells modulated completely within 24 hours, whereas no modulation occurred during 4 days in mice immunized with IgM antibody. However, in both instances, tumor cells grew actively, which indicated that tumor escape did not depend on achievement of a modulated state.

Evaluation of Human FcγRIIA (CD32) and FcγRIIIB (CD16) Polymorphisms in Caucasians and African-Americans Using Salivary DNA

PubMed Central

van Schie, Rob C. A. A.; Wilson, Mark E.

2000-01-01

Two classes of low-affinity receptors for the Fc region of immunoglobulin G (IgG) (FcγR) are constitutively expressed on resting human neutrophils. These receptors, termed FcγRIIa (CD32) and FcγRIIIb (CD16), display biallelic polymorphisms which have functional consequences with respect to binding and/or ingestion of targets opsonized by human IgG subclass antibodies. The H131-R131 polymorphism of CD32 influences binding of human IgG2 and, to a lesser extent, human IgG3 to neutrophils. The neutrophil antigen (NA1-NA2) polymorphism of CD16 influences the efficiency of phagocytosis of bacteria opsonized by human IgG1 and IgG3. These polymorphisms may influence host susceptibility to certain infectious and/or autoimmune diseases, prompting interest in the development of facile methods for determination of CD32 and CD16 genotype in various clinical settings. We previously reported that genomic DNA from saliva is a suitable alternative to DNA from blood in PCR-based analyses of CD32 and CD16 polymorphisms. In the present study, we utilized for the first time this salivary DNA-based methodology to define CD32 and CD16 genotypes in 271 Caucasian and 118 African-American subjects and to investigate possible linkage disequilibrium between certain CD32 and CD16 genotypes in these two ethnic groups. H131 and R131 gene frequencies were 0.45 and 0.55, respectively, among Caucasians and 0.59 among African-Americans. NA1 and NA2 gene frequencies were 0.38 and 0.62 among Caucasians and 0.39 and 0.61 among African-Americans. Since FcγRIIa and FcγRIIIb synergize in triggering neutrophils, we also assessed the frequency of different CD32 and CD16 genotype combinations in these two groups. In both groups, the R/R131-NA2/NA2 genotype combination was more common than the H/H131-NA1/NA1 combination (threefold for Caucasians versus sevenfold for African-Americans). Whether individuals with the combined R/R131-NA2/NA2 genotype are at greater risk for development of infectious and/or autoimmune diseases requires further investigation, which can be conveniently performed using DNA from saliva rather than blood. PMID:10882671

Acid-induced aggregation propensity of nivolumab is dependent on the Fc.

PubMed

Liu, Boning; Guo, Huaizu; Xu, Jin; Qin, Ting; Xu, Lu; Zhang, Junjie; Guo, Qingcheng; Zhang, Dapeng; Qian, Weizhu; Li, Bohua; Dai, Jianxin; Hou, Sheng; Guo, Yajun; Wang, Hao

2016-01-01

Nivolumab, an anti-programmed death (PD)1 IgG4 antibody, has shown notable success as a cancer treatment. Here, we report that nivolumab was susceptible to aggregation during manufacturing, particularly in routine purification steps. Our experimental results showed that exposure to low pH caused aggregation of nivolumab, and the Fc was primarily responsible for an acid-induced unfolding phenomenon. To compare the intrinsic propensity of acid-induced aggregation for other IgGs subclasses, tocilizumab (IgG1), panitumumab (IgG2) and atezolizumab (aglyco-IgG1) were also investigated. The accurate pH threshold of acid-induced aggregation for individual IgG Fc subclasses was identified and ranked as: IgG1 < aglyco-IgG1 < IgG2 < IgG4. This result was cross-validated by thermostability and conformation analysis. We also assessed the effect of several protein stabilizers on nivolumab, and found mannitol ameliorated the acid-induced aggregation of the molecule. Our results provide valuable insight into downstream manufacturing process development, especially for immune checkpoint modulating molecules with a human IgG4 backbone.

Life-threatening hemolytic anemia due to an autoanti-Pr cold agglutinin: evidence that glycophorin A antibodies may induce lipid bilayer exposure and cation permeability independent of agglutination.

PubMed

Brain, Michael C; Ruether, Bernard; Valentine, Karen; Brown, Christopher; ter Keurs, Henk

2010-02-01

The hemoglobin of a 29-year-old man fell below 35 g/L over 5 days, despite 14 units of red blood cells (RBCs), due to an anti-Pr cold agglutinin (CA). His hemolytic anemia necessitated respiratory support in intensive care for 4 weeks. The hemolysis was investigated by the effects on blood group-compatible RBCs of this anti-Pr and an anti-I CA and of a rabbit anti-human glycophorin A (GPA) immunoglobulin G (IgG) antibody on Ca(2+) permeability and of phosphatidylethanolamine (PE) exposure. 1) The anti-Pr CA (in a plasmapheresis product from the patient) was absorbed and eluted from RBC ghosts and its immunophenotype was determined by agarose electrophoresis and immunofixation. 2) Ca(2+) permeability was measured by the response of Fluo-3-labeled RBCs to addition of external Ca(2+). 3) Exposed PE was measured with streptavidin-labeled biotinylated peptide Ro 09-0198 (cinnamycin). 1) The patient's anti-Pr CA was a polyclonal IgG. 2) The anti-Pr and the rabbit anti-human glycophorin IgG, but not an anti-I CA, rapidly increased Ca(2+)-dependent fluorescence upon addition of external Ca(2+) in a fraction (15%-25%) of RBCs that also became positive for cinnamycin. 3) Trypsin treatment of RBCs reduced the Ca(2+) influx due to the anti-Pr IgG, but neither trypsin nor neuraminidase changed the responses to the rabbit anti-human GPA IgG. The anti-Pr CA and rabbit anti-human GPA increased exposure of PE and increased membrane Ca(2+) permeability that may have caused hemolysis. The difference in the responses to these antibodies to enzyme treatment of RBCs suggests that they react with different epitopes on GPA.

Asparagine-linked oligosaccharides present on a non-consensus amino acid sequence in the CH1 domain of human antibodies.

PubMed

Valliere-Douglass, John F; Kodama, Paul; Mujacic, Mirna; Brady, Lowell J; Wang, Wes; Wallace, Alison; Yan, Boxu; Reddy, Pranhitha; Treuheit, Michael J; Balland, Alain

2009-11-20

We report that N-linked oligosaccharide structures can be present on an asparagine residue not adhering to the consensus site motif NX(S/T), where X is not proline, described in the literature. We have observed oligosaccharides on a non-consensus asparaginyl residue in the C(H)1 constant domain of IgG1 and IgG2 antibodies. The initial findings were obtained from characterization of charge variant populations evident in a recombinant human antibody of the IgG2 subclass. HPLC-MS results indicated that cation-exchange chromatography acidic variant populations were enriched in antibody with a second glycosylation site, in addition to the well documented canonical glycosylation site located in the C(H)2 domain. Subsequent tryptic and chymotryptic peptide map data indicated that the second glycosylation site was associated with the amino acid sequence TVSWN(162)SGAL in the C(H)1 domain of the antibody. This highly atypical modification is present at levels of 0.5-2.0% on most of the recombinant antibodies that have been tested and has also been observed in IgG1 antibodies derived from human donors. Site-directed mutagenesis of the C(H)1 domain sequence in a recombinant-human IgG1 antibody resulted in an increase in non-consensus glycosylation to 3.15%, a greater than 4-fold increase over the level observed in the wild type, by changing the -1 and +1 amino acids relative to the asparagine residue at position 162. We believe that further understanding of the phenomenon of non-consensus glycosylation can be used to gain fundamental insights into the fidelity of the cellular glycosylation machinery.

Limitations of a hemolytic plaque assay for IgG-anti-IgG rheumatoid factor-producing cells.

PubMed

Venn, A J; Dresser, D W

1987-09-24

An attempt has been made to develop a hemolytic plaque assay capable of detecting homophile IgG rheumatoid factor (RF)-producing cells. Anti-immunoglobulin allotype-developing reagents were used to distinguish between target and effector IgG. The hemolytic assay has been used to demonstrate an apparently high level of homophile IgM and IgG RF-producing cells in the spleens and lymph nodes of mice stimulated by LPS. However, it appears that a large proportion of the plaques obtained in these assays are due to an artefact resulting from cross-linking of target and effector molecules by the developing reagents. In the case of IgM RF the artefact depends on the presence of a small contamination of the target IgG by IgM, allowing cross-linking of target and effector IgM by the anti-mu-specific developing reagent. With the IgG RF, cross-reactivity of the rabbit anti-Ighb allotype-developing serum for the 'wrong' (Igha) allotype, normally undetectable, becomes sufficient to be biologically relevant when the developing antibody is complexed by being bound to its target (Ighb) allotype. Nevertheless anti-allotype reagents may afford an accurate means of detecting homophile IgG RF producing cells using other assay systems.

Bio-nanocapsules displaying various immunoglobulins as an active targeting-based drug delivery system.

PubMed

Tatematsu, Kenji; Iijima, Masumi; Yoshimoto, Nobuo; Nakai, Tadashi; Okajima, Toshihide; Kuroda, Shun'ichi

2016-04-15

The bio-nanocapsule (BNC) is an approximately 30-nm particle comprising the hepatitis B virus (HBV) envelope L protein and a lipid bilayer. The L protein harbors the HBV-derived infection machinery; therefore, BNC can encapsulate payloads such as drugs, nucleic acids, and proteins and deliver them into human hepatocytes specifically in vitro and in vivo. To diversify the possible functions of BNC, we generated ZZ-BNC by replacing the domain indispensable for the human hepatotrophic property of BNC (N-terminal region of L protein) with the tandem form of the IgG Fc-binding Z domain of Staphylococcus aureus protein A. Thus, the ZZ-BNC is an active targeting-based drug delivery system (DDS) nanocarrier that depends on the specificity of the IgGs displayed. However, the Z domain limits the animal species and subtypes of IgGs that can be displayed on ZZ-BNC. In this study, we introduced into BNC an Ig κ light chain-binding B1 domain of Finegoldia magna protein L (protein-L B1 domain) and an Ig Fc-binding C2 domain of Streptococcus species protein G (protein-G C2 domain) to produce LG-BNC. The LL-BNC was constructed in a similar way using a tandem form of the protein-L B1 domain. Both LG-BNC and LL-BNC could display rat IgGs, mouse IgG1, human IgG3, and human IgM, all of which not binding to ZZ-BNC, and accumulate in target cells in an antibody specificity-dependent manner. Thus, these BNCs could display a broad spectrum of Igs, significantly improving the prospects for BNCs as active targeting-based DDS nanocarriers. We previously reported that ZZ-BNC, bio-nanocapsule deploying the IgG-binding Z domain of protein A, could display cell-specific antibody in an oriented immobilization manner, and act as an active targeting-based DDS nanocarrier. Since the Z domain can only bind to limited types of Igs, we generated BNCs deploying other Ig-binding domains: LL-BNC harboring the tandem form of Ig-binding domain of protein L, and LG-BNC harboring the Ig binding domains of protein L and protein G sequentially. Both BNCs could display a broader spectrum of Igs than does the ZZ-BNC. When these BNCs displayed anti-CD11c IgG or anti-EGFR IgG, both of which cannot bind to Z domain, they could bind to and then enter their respective target cells. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Idiotypic specificities and cross-reactivities of rabbit antibodies to human antidextran.

PubMed Central

Outschoorn, I M

1979-01-01

Idiotypic antibodies were prepared by immunizing two groups of rabbits with dextran-antidextran specific precipitates and purified antidextran obtained subsequently from the same human donor. Half of the animals were made tolerant to pooled human IgG. Tests showed that sera from tolerant rabbits reacted better with the antidextran preparation used to immunize the other group of animals than with the antidextran that formed part of their immunogen. Non-tolerant animals did not recognize this serological difference. Sera from animals immunized with the antidextran preparation donated later reacted better with this material irrespective of their tolerance to human IgG. PMID:92456

Genetically engineered multivalent single chain antibody constructs for cancer therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Surinder Batra, Ph D

2006-02-27

Current therapeutic approaches against the advanced stages of human solid tumors are palliative rather than curative. Many modalities, including, surgery, radiation, and chemotherapy, either alone or in combination have met with only modest success for advanced metastatic cancers. Radioimmunotherapy (RIT) combines the specificity of monoclonal antibodies with cytotxic effects of radioisotopes. It is the smart way of delivering radiation to the known and occult metastatic cancer cells and is independent of drug toxicity and/or hormone resistance. The tumor associated glycoprotein-72 (TAG-72) containing the unique disaccharide sialyl-Tn, is highly expressed in majority of adenocarcinomas, including carcinomas of the prostate, breast, ovaries,more » pancreas and colon (80-90%) compared to undetectable expression in normal tissues. Monoclonal antibody CC49, reactive with TAG-72, after conjugation to potent gamma- and beta-emitting radionuclides, has been useful in selective systemic radiolocalization of disease and therapy of primary and metastatic tumor sites. However, limited therapeutic responses were observed in patients. Limited success of antibody based delivery of radioisotopes can be attributed to several factors including undesirable pharmacokinetics, poor tumor uptake and high immunogenicity of intact antibodies (IgGs). The primary factors contributing towards the failure of RIT include: 1) longer serum half-lives of the intact IgG molecules resulting in the radiotoxicity, 2) generation of human antibodies against murine antibodies (HAMA) that limits the frequency of dose administration, 3) poor diffusion rates of intact IgG due to the large size and 4) high interstitial fluid pressures (IFP) encountered in solid tumors. The major goal of our multidisciplinary project was to develop specific novel radiopharmaceuticals, with desired pharmacokinetics, for the diagnosis and therapy of solid tumors. To overcome the low uptake of radioactivity by tumors and to increase its tumor: normal tissue ratio for improved therapeutic index, we engineered a variety antibody constructs. These constructs were evaluated using novel approaches like special radionuclides, pretargeting and optimization. Due to the smaller size, the engineered antibody molecules should penetrate better throughout a tumor mass, with less dose heterogeneity, than is the case with intact IgG. Multivalent scFvs with an appropriate radionuclide, therefore, hold promising prospects for cancer therapy and clinical imaging in MAb-based radiopharmaceuticals. In addition, the human anti-mouse antibodies (HAMA) responses in patients against antibody-based therapy are usually directed against the immunoglobulin constant regions; however, anti-idiotypic responses can also be detected. The HAMA responses reduce the efficacy of treatment by removing the circulating antibody molecules, fragments, and possibly scFvs by altering the pharmacokinetic properties of the antibody. HAMA responses against divalent IgG, divalent Ig fragments, and possibly multimeric scFvs could cause immune complex formation with hypersensitivity or allergic reactions that could be harmful to patients. The use of small molecules, such as scFvs (monomeric as well as multimeric), with their shorter biological half-lives and the lack of the constant regions and humanized variable (binding regions) performed in our studies should reduce the development of HAMA. The generation of humanized and fully human scFvs should further reduce the development of HAMA. Specific accomplishments on the project are the production of large amounts of recombinant antibodies as they are required in large amounts for cancer diagnosis and therapy. A variety of single-chain Fv (scFv) constructs were engineered for the desired pharmacokinetic properties. Tetrameric and dimeric scFvs showed a two-fold advantage: (1) there was a considerable gain in avidity as compared to smaller fragments, and (2) the biological half-life was more compatible with RIT and RIS requirements. For RIT, delivery for sc(Fv)2 and [sc(Fv)2]2 in a fractionated schedule clearly presented a therapeutic advantage over single administration. The treatment group receiving tetravalent scFv showed a statistically significant prolonged survival with both single and fractionated administrations. 99mTc-labeled multivalent scFvs show good tumor targeting characteristics with high radiolocalization indices (tumor:background ratio). Macroautoradiography performed at 6 and 16 h post administration of labeled 99mTc-sc(Fv)2 and 99mTc-[sc(Fv)2] clearly detected the tumors in mice. Huamnaized scFs showed decreased immunogencity with patient sera.« less

Chemiluminescence enzyme immunoassay using ProteinA-bacterial magnetite complex

NASA Astrophysics Data System (ADS)

Matsunaga, Tadashi; Sato, Rika; Kamiya, Shinji; Tanaka, Tsuyosi; Takeyama, Haruko

1999-04-01

Bacterial magnetic particles (BMPs) which have ProteinA expressed on their surface were constructed using magA which is a key gene in BMP biosynthesis in the magnetic bacterium Magnetospirillum sp. AMB-1. Homogenous chemiluminescence enzyme immunoassay using antibody bound ProteinA-BMP complexes was developed for detection of human IgG. A good correlation between the luminescence yield and the concentration of human IgG was obtained in the range of 1-10 3 ng/ml.

Serological prevalence of human parvovirus B19 in diseases or disordersrelated to different human body systems.

PubMed

Aktaş, Osman; Aydin, Hakan; Uslu, Hakan

2016-02-17

Human parvovirus B19 is a pathogen that affects different parts of the body. We planned this study because of the lack of data on B19 seroprevalence based on different body-system diseases. The prevalence of parvovirus B19 antibodies was investigated retrospectively in 1239 patients by review of medical records from 2009-2012, according to their diseases classified under general titles in compliance with the International Classification of Diseases (ICD-10). Parvovirus B19-specific antibodies were detected by quantitative enzyme immunoassays. The positivity rate was 27.8% for only IgG, 8.5% for only IgM, and 2.6% for both IgG and IgM. The highest positivity for IgG alone was found in musculoskeletal system and connective tissue diseases (55.9%), while the highest positivity for IgM was found in neoplasms (16.4%). The highest positivity for IgG was seen in rheumatoid arthritis (72.2%) and pregnancy (52.6%), and the highest positivity for total IgM was found in upper respiratory tract disease (21.0%) and hepatic failure (17.1%). Parvovirus B19 seroprevalence was relatively low in northeastern Anatolia compared to most serological studies conducted in other regions. We think that this study has provided the first wide-ranging information on the seroprevalence of B19 in diseases and disorders of the major human body systems.

Studies of nontarget-mediated distribution of human full-length IgG1 antibody and its FAb fragment in cardiovascular and metabolic-related tissues.

PubMed

Davidsson, Pia; Söderling, Ann-Sofi; Svensson, Lena; Ahnmark, Andrea; Flodin, Christine; Wanag, Ewa; Screpanti-Sundqvist, Valentina; Gennemark, Peter

2015-05-01

Tissue distribution and pharmacokinetics (PK) of full-length nontargeted antibody and its antigen-binding fragment (FAb) were evaluated for a range of tissues primarily of interest for cardiovascular and metabolic diseases. Mice were intravenously injected with a dose of 10 mg/kg of either human IgG1or its FAb fragment; perfused tissues were collected at a range of time points over 3 weeks for the human IgG1 antibody and 1 week for the human FAb antibody. Tissues were homogenized and antibody concentrations were measured by specific immunoassays on the Gyros system. Exposure in terms of maximum concentration (Cmax ) and area under the curve was assessed for all nine tissues. Tissue exposure of full-length antibody relative to plasma exposure was found to be between 1% and 10%, except for brain (0.2%). Relative concentrations of FAb antibody were the same, except for kidney tissue, where the antibody concentration was found to be ten times higher than in plasma. However, the absolute tissue uptake of full-length IgG was significantly higher than the absolute tissue uptake of the FAb antibody. This study provides a reference PK state for full-length whole and FAb antibodies in tissues related to cardiovascular and metabolic diseases that do not include antigen or antibody binding. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

Similar disturbances in B cell activity and regulatory T cell function in Henoch-Schonlein purpura and systemic lupus erythematosus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beale, M.G.; Nash, G.S.; Bertovich, M.J.

1982-01-01

The immunoglobulin synthesizing activities of peripheral mononuclear cells (MNC) from five patients with Henoch-Schonlein purpura (HSP) and eight patients with active systemic lupus erythematosus (SLE) were compared. Cumulative amounts of IgM, IgG, and IgA synthesized and secreted by unstimulated and PWM-stimulated patient cells over a 12-day period were determied in a solid-phase radioimmunoassay. In unstimulated control cultures mean rates of IgM, IgG, and IgA synthesis were less than 250 ng/ml. The synthetic activities of patient MNC were markedly increased. In HSP cultures IgA was the major immunoglobulin class produced (2810 x/divide 1.33 ng/ml) followed by IgG (1754 x/divide 1.32 ng/ml)more » and IgM (404 x/divide 1.16 ng/ml). In SLE cultures IgA and IgG syntheses were equally elevated (4427 x/divide 1.20 and 4438 x/divide 1.49 ng/ml, respectively) whereas IgM synthesis averaged 967 x/divide 1.66 ng/ml. PWM stimulation of pateient MNC caused a sharp decline in the synthesis of all three immunoglobulin classes. After T cell depletion B cell-enriched fractions from HSP and SLE patients maintained high levels of IgA and IgG synthesis that were inhibited by PWM and by normal allogeneic but not autologous T cells. In PWM-stimulted co-cultures, patient T cells nonspecifically suppressed the synthetic activities of autologous and control B cells. in contrast patient B cells achieved normal levels of immunoglobulin synthesis when cultured with control T cells plus PWM. In longitudinal studies patient B and T cell disturbances persisted despite clinical improvement.« less

Effects of routine prophylactic vaccination or administration of aluminum adjuvant alone on allergen-specific serum IgE and IgG responses in allergic dogs.

PubMed

Tater, Kathy C; Jackson, Hilary A; Paps, Judy; Hammerberg, Bruce

2005-09-01

To determine the acute corn-specific serum IgE and IgG, total serum IgE, and clinical responses to s.c. administration of prophylactic vaccines and aluminum adjuvant in corn-allergic dogs. 20 allergic and 8 nonallergic dogs. 17 corn-allergic dogs were vaccinated. Eight clinically normal dogs also were vaccinated as a control group. Serum corn-specific IgE, corn-specific IgG, and total IgE concentrations were measured in each dog before vaccination and 1 and 3 weeks after vaccination by use of an ELISA. The corn-allergic dogs also had serum immunoglobulin concentrations measured at 8 and 9 weeks after vaccination. Twenty allergic dogs received a s.c. injection of aluminum adjuvant, and serum immunoglobulin concentrations were measured in each dog 1, 2, 3, 4, and 8 weeks after injection. The allergic dogs were examined during the 8 weeks after aluminum administration for clinical signs of allergic disease. The allergic dogs had significant increases in serum corn-specific IgE and IgG concentrations 1 and 3 weeks after vaccination but not 8 or 9 weeks after vaccination. Control dogs did not have a significant change in serum immunoglobulin concentrations after vaccination. After injection of aluminum adjuvant, the allergic dogs did not have a significant change in serum immunoglobulin concentrations or clinical signs. Allergen-specific IgE and IgG concentrations increase after prophylactic vaccination in allergic dogs but not in clinically normal dogs. Prophylactic vaccination of dogs with food allergies may affect results of serologic allergen-specific immunoglobulin testing performed within 8 weeks after vaccination.

Proposal and validation of prognostic scoring systems for IgG and IgA monoclonal gammopathies of undetermined significance.

PubMed

Rossi, Francesca; Petrucci, Maria Teresa; Guffanti, Andrea; Marcheselli, Luigi; Rossi, Davide; Callea, Vincenzo; Vincenzo, Federico; De Muro, Marianna; Baraldi, Alessandra; Villani, Oreste; Musto, Pellegrino; Bacigalupo, Andrea; Gaidano, Gianluca; Avvisati, Giuseppe; Goldaniga, Maria; Depaoli, Lorenzo; Baldini, Luca

2009-07-01

The presenting clinico-hematologic features of 1,283 patients with IgG and IgA monoclonal gammopathies of undetermined significance (MGUS) were correlated with the frequency of evolution into multiple myeloma (MM). Two IgG MGUS populations were evaluated: a training sample (553 patients) and a test sample (378 patients); the IgA MGUS population consisted of 352 patients. Forty-seven of the 553 training group patients and 22 of 378 test group IgG patients developed MM after a median follow-up of 6.7 and 3.6 years, respectively. Multivariate analysis showed that serum monoclonal component (MC) levels of < or =1.5 g/dL, the absence of light-chain proteinuria and normal serum polyclonal immunoglobulin levels defined a prognostically favorable subset of patients, and could be used to stratify the patients into three groups at different 10-year risk of evolution (hazard ratio, 1.0, 5.04, 11.2; P < 0.001). This scoring system was validated in the test sample. Thirty of the 352 IgA patients developed MM after a median follow-up of 4.8 years, and multivariate analysis showed that hemoglobin levels of <12.5 g/dL and reduced serum polyclonal immunoglobulin correlated with progression. A pooled statistical analysis of all of the patients confirmed the validity of Mayo Clinic risk model showing that IgA class, serum MC levels, and light-chain proteinuria are the most important variables correlated with disease progression. Using simple variables, we validated a prognostic model for IgG MGUS. Among the IgA cases, the possible prognostic role of hemoglobin emerged in addition to a decrease in normal immunoglobulin levels.

Epithelial IgG and its relationship to the loss of F508 in the common mutant form of the cystic fibrosis transmembrane conductance regulator.

PubMed

Treharne, Kate J; Cassidy, Diane; Goddard, Catharine; Colledge, William H; Cassidy, Andrew; Mehta, Anil

2009-08-06

The most debilitating feature of cystic fibrosis (CF) disease is uncontrolled inflammation of respiratory epithelium. The relationship between the commonest mutated form of CFTR (F508del or DeltaF508) and inflammation has not yet been elucidated. Here, we present a new paradigm suggesting that CFTR can interact with intra-epithelial IgG, establishing a direct link between normal CFTR and the immune system. Further, our data show that the amino-acid sequence local to F508 can bind IgG with high affinity, dependent on F508, such that loss of F508 abolishes this link both in vitro and in the intact cell.

The Emerging Importance of IgG Fab Glycosylation in Immunity.

PubMed

van de Bovenkamp, Fleur S; Hafkenscheid, Lise; Rispens, Theo; Rombouts, Yoann

2016-02-15

Human IgG is the most abundant glycoprotein in serum and is crucial for protective immunity. In addition to conserved IgG Fc glycans, ∼15-25% of serum IgG contains glycans within the variable domains. These so-called "Fab glycans" are primarily highly processed complex-type biantennary N-glycans linked to N-glycosylation sites that emerge during somatic hypermutation. Specific patterns of Fab glycosylation are concurrent with physiological and pathological conditions, such as pregnancy and rheumatoid arthritis. With respect to function, Fab glycosylation can significantly affect stability, half-life, and binding characteristics of Abs and BCRs. Moreover, Fab glycans are associated with the anti-inflammatory activity of IVIgs. Consequently, IgG Fab glycosylation appears to be an important, yet poorly understood, process that modulates immunity. Copyright © 2016 by The American Association of Immunologists, Inc.

Isotype Diversification of IgG Antibodies to HIV Gag Proteins as a Therapeutic Vaccination Strategy for HIV Infection.

PubMed

French, Martyn A; Abudulai, Laila N; Fernandez, Sonia

2013-08-09

The development of vaccines to treat and prevent human immunodeficiency virus (HIV) infection has been hampered by an incomplete understanding of "protective" immune responses against HIV. Natural control of HIV-1 infection is associated with T-cell responses against HIV-1 Gag proteins, particularly CD8⁺ T-cell responses restricted by "protective" HLA-B alleles, but other immune responses also contribute to immune control. These immune responses appear to include IgG antibodies to HIV-1 Gag proteins, interferon-a-dependant natural killer (NK) cell responses and plasmacytoid dendritic cell (pDC) responses. Here, it is proposed that isotype diversification of IgG antibodies against HIV-1 Gag proteins, to include IgG2, as well as IgG3 and IgG1 antibodies, will broaden the function of the antibody response and facilitate accessory cell responses against HIV-1 by NK cells and pDCs. We suggest that this should be investigated as a vaccination strategy for HIV-1 infection.

Use of hybridoma immunoglobulin switch variants in the analysis of the protective properties of anti-lipopolysaccharide antibodies in Escherichia coli K1 infection.

PubMed

Pelkonen, S; Pluschke, G

1989-10-01

Functional properties of rat immunoglobulins obtained from hybridoma isotype switch variants were studied in vivo in a rat model for neonatal bacterial sepsis. Escherichia coli 018:K1, a common cause of human neonatal sepsis and meningitis, was injected intravenously into 6-day-old rats after incubation with 018-specific antibodies IgM, IgG1, IgG2a, IgG2b, IgG2c, IgE and IgA. The clearance of bacteria treated with saline or IgE was low, whereas monoclonal antibodies of other isotypes triggered hepatic sequestration and killing of the K1 E. coli cells. All four IgG subclasses were more efficient than IgM and IgA. Comparable results were obtained upon injecting antibodies into rats with an established fulminating bacteraemia. IgM was inactive in animals depleted of complement with cobra-venom factor (CVF), whereas IgG2b was able to trigger hepatic clearance independently of complement.

RAPID CLONING OF HIGH AFFINITY HUMAN MONOCLONAL ANTIBODIES AGAINST INFLUENZA VIRUS

PubMed Central

Wrammert, Jens; Smith, Kenneth; Miller, Joe; Langley, Trey; Kokko, Kenneth; Larsen, Christian; Zheng, Nai-Ying; Mays, Israel; Garman, Lori; Helms, Christina; James, Judith; Air, Gillian M.; Capra, J. Donald; Ahmed, Rafi; Wilson, Patrick C.

2008-01-01

Pre-existing neutralizing antibody provides the first line of defense against pathogens in general. For influenza virus, annual vaccinations are given to maintain protective levels of antibody against the currently circulating strains. Here we report that after booster vaccination there was a rapid and robust influenza-specific IgG+ antibody-secreting plasma cell (ASC) response that peaked at approximately day 7 and accounted for up to 6% of peripheral blood B cells. These ASCs could be distinguished from influenza-specific IgG+ memory B cells that peaked 14 to 21 days after vaccination and averaged 1% of all B cells. Importantly, as much as 80% of ASCs purified at the peak of the response were influenza specific. This ASC response was characterized by a highly restricted B cell receptor (BCR) repertoire that in some donors were dominated by only a few B cell clones. This pauci-clonal response, however, showed extensive intraclonal diversification from accumulated somatic mutations. We used the immunoglobulin variable regions isolated from sorted single ASCs to produce over fifty human monoclonal antibodies (mAbs) that bound to the three influenza vaccine strains with high affinity. This strategy demonstrates that we can generate multiple high affinity mAbs from humans within a month after vaccination. The panel of influenza virus specific human mAbs allowed us to address the issue of original antigenic sin (OAS) - the phenomenon where the induced antibody shows higher affinity to a previously encountered influenza virus strain compared to the virus strain present in the vaccine1. However, we found that the vast majority of the influenza virus specific mAbs showed the highest affinity for the current vaccine strain. Thus, OAS does not seem to be a common occurrence in normal healthy adults receiving influenza vaccination. PMID:18449194

Rapid cloning of high-affinity human monoclonal antibodies against influenza virus.

PubMed

Wrammert, Jens; Smith, Kenneth; Miller, Joe; Langley, William A; Kokko, Kenneth; Larsen, Christian; Zheng, Nai-Ying; Mays, Israel; Garman, Lori; Helms, Christina; James, Judith; Air, Gillian M; Capra, J Donald; Ahmed, Rafi; Wilson, Patrick C

2008-05-29

Pre-existing neutralizing antibody provides the first line of defence against pathogens in general. For influenza virus, annual vaccinations are given to maintain protective levels of antibody against the currently circulating strains. Here we report that after booster vaccination there was a rapid and robust influenza-specific IgG+ antibody-secreting plasma cell (ASC) response that peaked at approximately day 7 and accounted for up to 6% of peripheral blood B cells. These ASCs could be distinguished from influenza-specific IgG+ memory B cells that peaked 14-21 days after vaccination and averaged 1% of all B cells. Importantly, as much as 80% of ASCs purified at the peak of the response were influenza specific. This ASC response was characterized by a highly restricted B-cell receptor (BCR) repertoire that in some donors was dominated by only a few B-cell clones. This pauci-clonal response, however, showed extensive intraclonal diversification from accumulated somatic mutations. We used the immunoglobulin variable regions isolated from sorted single ASCs to produce over 50 human monoclonal antibodies (mAbs) that bound to the three influenza vaccine strains with high affinity. This strategy demonstrates that we can generate multiple high-affinity mAbs from humans within a month after vaccination. The panel of influenza-virus-specific human mAbs allowed us to address the issue of original antigenic sin (OAS): the phenomenon where the induced antibody shows higher affinity to a previously encountered influenza virus strain compared with the virus strain present in the vaccine. However, we found that most of the influenza-virus-specific mAbs showed the highest affinity for the current vaccine strain. Thus, OAS does not seem to be a common occurrence in normal, healthy adults receiving influenza vaccination.

Characterization of the Humoral Immune Response during Staphylococcus aureus Bacteremia and Global Gene Expression by Staphylococcus aureus in Human Blood

PubMed Central

den Reijer, Paul Martijn; Lemmens-den Toom, Nicole; Kant, Samantha; Snijders, Susan V.; Boelens, Hélène; Tavakol, Mehri; Verkaik, Nelianne J.; van Belkum, Alex; Verbrugh, Henri A.; van Wamel, Willem J. B.

2013-01-01

Attempts to develop an efficient anti-staphylococcal vaccine in humans have so far been unsuccessful. Therefore, more knowledge of the antigens that are expressed by Staphylococcus aureus in human blood and induce an immune response in patients is required. In this study we further characterize the serial levels of IgG and IgA antibodies against 56 staphylococcal antigens in multiple serum samples of 21 patients with a S. aureus bacteremia, compare peak IgG levels between patients and 30 non-infected controls, and analyze the expression of 3626 genes by two genetically distinct isolates in human blood. The serum antibody levels were measured using a bead-based flow cytometry technique (xMAP®, Luminex corporation). Gene expression levels were analyzed using a microarray (BµG@s microarray). The initial levels and time taken to reach peak IgG and IgA antibody levels were heterogeneous in bacteremia patients. The antigen SA0688 was associated with the highest median initial-to-peak antibody fold-increase for IgG (5.05-fold) and the second highest increase for IgA (2.07-fold). Peak IgG levels against 27 antigens, including the antigen SA0688, were significantly elevated in bacteremia patients versus controls (P≤0.05). Expression of diverse genes, including SA0688, was ubiquitously high in both isolates at all time points during incubation in blood. However, only a limited number of genes were specifically up- or downregulated in both isolates when cultured in blood, compared to the start of incubation in blood or during incubation in BHI broth. In conclusion, most staphylococcal antigens tested in this study, including many known virulence factors, do not induce uniform increases in the antibody levels in bacteremia patients. In addition, the expression of these antigens by S. aureus is not significantly altered by incubation in human blood over time. One immunogenic and ubiquitously expressed antigen is the putative iron-regulated ABC transporter SA0688. PMID:23308212

Local tolerance and stability up to 24 months of a new 20% proline-stabilized polyclonal immunoglobulin for subcutaneous administration.

PubMed

Maeder, Werner; Lieby, Patricia; Sebald, Andrea; Spycher, Martin; Pedrussio, Renzo; Bolli, Reinhard

2011-01-01

Subcutaneous administration of human IgG is an alternative to intravenous replacement therapy that is associated with more stable serum IgG levels and fewer systemic adverse events. Highly concentrated IgG solutions are most convenient to minimize infusion volume, but their preparation and stability presents substantial technical difficulties. We report on the stability and local tolerance of IgPro20, an l-proline-stabilized, 20% polyvalent human IgG developed for subcutaneous administration. Stability was tested according to ICH guidelines. Local tolerance and vasoactivity were examined in rabbit and rat models, respectively. The presence of l-proline in IgPro20 reduced viscosity and addition of Polysorbate 80 and inert gassing improved the appearance of the solution. After storage at 25 °C for 24 months, monomer + dimer content, aggregates, and fragments were within specification (≥ 90.0%, ≤ 4.0%, and ≤ 10.0%, respectively), and Fc function and antibody activities were maintained. In rats, intravenous injection of IgPro20 produced mild and transient hypotension comparable to that seen with intravenous IgG products. Local tolerance of IgPro20 in rabbits was comparable to that of a marketed subcutaneous IgG, Beriglobin P. Functionality and quality of IgPro20 are maintained during storage at 25 °C for at least 24 months. The product is well tolerated as assessed in animal models. Copyright © 2010 The International Association for Biologicals. Published by Elsevier Ltd. All rights reserved.

Human Antibodies to a Mr 155,000 Plasmodium falciparum Antigen Efficiently Inhibit Merozoite Invasion

NASA Astrophysics Data System (ADS)

Wahlin, Birgitta; Wahlgren, Mats; Perlmann, Hedvig; Berzins, Klavs; Bjorkman, Anders; Patarroyo, Manuel E.; Perlmann, Peter

1984-12-01

IgG from a donor clinically immune to Plasmodium falciparum malaria strongly inhibited reinvasion in vitro of human erythrocytes by the parasite. When added to monolayers of glutaraldehyde-fixed and air-dried erythrocytes infected with the parasite, this IgG also displayed a characteristic immunofluorescence restricted to the surface of infected erythrocytes. Elution of the IgG adsorbed to such monolayers gave an antibody fraction that was 40 times more efficient in the reinvasion inhibition assay (50% inhibition titer, <1 μ g/ml) than the original IgG preparation. The major antibody in this eluate was directed against a parasite-derived antigen of Mr 155,000 (Pf 155) deposited by the parasite in the erythrocyte membrane in the course of invasion. A detailed study of IgG fractions from 11 donors with acute P. falciparum malaria or clinical immunity revealed the existence of an excellent correlation between their capacities to stain the surface of infected erythrocytes, their titers in reinvasion inhibition, and the presence of antibodies to Pf 155 as detected by immunoblotting. No such correlations were seen when the IgG fractions were analyzed for immunofluorescence of intracellular parasites or for the presence of antibodies to other parasite antigens as detected by immunoprecipitation of [35S]methionine-labeled and NaDodSO4/PAGE-separated parasite extracts. The results suggest that Pf 155 has an important role in the process of erythrocyte infection and that host antibodies to this antigen may efficiently interfere with this process.

Estimation of protective levels of anti-O-specific lipopolysaccharide immunoglobulin G antibody against experimental Escherichia coli infection.

PubMed

Schiff, D E; Wass, C A; Cryz, S J; Cross, A S; Kim, K S

1993-03-01

Serum obtained after immunization with an O18 polysaccharide-toxin A conjugate vaccine was evaluated for the estimation of protective levels of anti-O-specific lipopolysaccharide (LPS) immunoglobulin G (IgG) antibody against bacteremia and death caused by a homologous serotype of Escherichia coli K1 strains. Passive transfer of rabbit serum conferred significant protection from a lethal E. coli infection in a neonatal rat model. The overall incidence of bacteremia and mortality was 4% in rat pups receiving undiluted postvaccination serum, while that in control animals was 100% (P < 0.001). The overall incidences of bacteremia were 5 and 72% for animals with serum anti-O18 LPS IgG concentrations of > 1.0 and < 1.0 microgram/ml, respectively, while the overall incidences of mortality for animals with serum anti-O18 LPS IgG levels of > 1.0 and < 1.0 microgram/ml were 0 and 72%, respectively (P < 0.001). Protection against E. coli infection was also demonstrated with human anti-O18 polysaccharide IgG. None of the animals with human anti-O18 LPS IgG levels of > 1 microgram/ml had bacteremia after bacterial challenge, whereas all animals with bacteremia at 18 h had levels of < 1 microgram/ml. These findings suggest that serum anti-O18 LPS IgG concentrations of > 1.0 microgram/ml may provide protection against bacteremia and death caused by a homologous E. coli K1 infection.

Specific Immunoglobulin (Ig) G Reference Intervals for Common Food, Insect, and Mold Allergens.

PubMed

Martins, Thomas B; Bandhauer, Michael E; Wilcock, Diane M; Hill, Harry R; Slev, Patricia R

2016-12-01

The clinical utility of serum IgG measurement in the diagnosis of allergy and food-induced hypersensitivity has been largely discredited. Recent studies, however, have shown that specific IgG can inhibit IgE mediated allergies, and may play a role in allergen specific desensitization. Accurate reference intervals for IgG specific allergens have not been widely established and are needed for better interpretation of serum antibody concentrations. In this study we established 64 IgG reference intervals for 48 common food allergens, 5 venoms, and 11 molds. Specific IgG concentrations were determined employing an automated fluorescent enzyme immunoassay on serum samples from 130 normal adults (65 males and 65 females), age range 18-69 y, mean 37.3 y. The lower reference interval limit for all allergens tested (n=64) was <2 mcg/mL. The median upper reference interval value for all 64 allergens was 12.9 mcg/mL, with Tuna (f40) having the lowest upper interval limit at 3.8 mcg/mL, and the mold Setomelanomma rostrate (m8) demonstrating the highest upper interval limit at 131 mcg/L. The considerable variation observed among the upper reference interval limits emphasizes the need for the establishment of allergen specific ranges for IgG. These newly established ranges should be a useful aid for clinicians in the interpretation of laboratory serum IgG results. © 2016 by the Association of Clinical Scientists, Inc.

Factor Xa Mediates Calcium Flux in Endothelial Cells and is Potentiated by Igg From Patients With Lupus and/or Antiphospholipid Syndrome.

PubMed

Artim-Esen, Bahar; Smoktunowicz, Natalia; McDonnell, Thomas; Ripoll, Vera M; Pericleous, Charis; Mackie, Ian; Robinson, Eifion; Isenberg, David; Rahman, Anisur; Ioannou, Yiannis; Chambers, Rachel C; Giles, Ian

2017-09-07

Factor (F) Xa reactive IgG isolated from patients with antiphospholipid syndrome (APS) display higher avidity binding to FXa with greater coagulant effects compared to systemic lupus erythematosus (SLE) non APS IgG. FXa signalling via activation of protease-activated receptors (PAR) leads to increased intracellular calcium (Ca 2+ ). Therefore, we measured alterations in Ca 2+ levels in human umbilical vein endothelial cells (HUVEC) following FXa-mediated PAR activation and investigated whether FXa reactive IgG from patients with APS or SLE/APS- alter these responses. We observed concentration-dependent induction of Ca 2+ release by FXa that was potentiated by APS-IgG and SLE/APS- IgG compared to healthy control subjects' IgG, and FXa alone. APS-IgG and SLE/APS- IgG increased FXa mediated NFκB signalling and this effect was fully-retained in the affinity purified anti-FXa IgG sub-fraction. Antagonism of PAR-1 and PAR-2 reduced FXa-induced Ca 2+ release. Treatment with a specific FXa inhibitor, hydroxychloroquine or fluvastatin significantly reduced FXa-induced and IgG-potentiated Ca 2+ release. In conclusion, PAR-1 and PAR-2 are involved in FXa-mediated intracellular Ca 2+ release in HUVEC and FXa reactive IgG from patients with APS and/or SLE potentiate this effect. Further work is required to explore the potential use of IgG FXa reactivity as a novel biomarker to stratify treatment with FXa inhibitors in these patients.

Catalase activity of IgG antibodies from the sera of healthy donors and patients with schizophrenia

PubMed Central

Ermakov, Evgeny A.; Smirnova, Ludmila P.; Bokhan, Nikolay A.; Semke, Arkadiy V.; Ivanova, Svetlana A.; Buneva, Valentina N.

2017-01-01

We present first evidence showing that some electrophoretically homogeneous IgGs from the sera of patients with schizophrenia (36.4%) and their Fab and F(ab)2 fragments as well as from healthy donors (33.3%) possess catalase activity. The relative catalase activity of IgGs from the sera of individual schizophrenia patients (and healthy donors) significantly varied from patient to patient, but the activity of IgGs from healthy donors is on average 15.8-fold lower than that for schizophrenia patients. After extensive dialysis of purified IgGs against EDTA chelating metal ions, the relative catalase activity of IgGs decreases on average approximately 2.5–3.7-fold; all IgGs possess metal-dependent and independent catalase activity. The addition of external Me2+ ions to dialyzed and non-dialyzed IgGs leads to a significant increase in their activity. The best activator of dialyzed and non-dialyzed IgGs is Co2+, the activation by Cu2+, Mn2+, and Ni2+ ions were rare and always lower than by Co2+. Every IgG preparation demonstrates several individual sets of very well expressed pH optima in the pH range from 4.0 to 9.5. These data speak for the individual repertoire of catalase IgGs in every person and an extreme diversity of abzymes in their pH optima and activation by different metal ions. It is known that antioxidant enzymes such as superoxide dismutases, catalases, and glutathione peroxidases represent critical defense mechanisms preventing oxidative modifications of DNA, proteins, and lipids. Catalase activity of human IgGs could probably also play a major role in the protection of organisms from oxidative stress and toxic compounds. PMID:28945759

Catalase activity of IgG antibodies from the sera of healthy donors and patients with schizophrenia.

PubMed

Ermakov, Evgeny A; Smirnova, Ludmila P; Bokhan, Nikolay A; Semke, Arkadiy V; Ivanova, Svetlana A; Buneva, Valentina N; Nevinsky, Georgy A

2017-01-01

We present first evidence showing that some electrophoretically homogeneous IgGs from the sera of patients with schizophrenia (36.4%) and their Fab and F(ab)2 fragments as well as from healthy donors (33.3%) possess catalase activity. The relative catalase activity of IgGs from the sera of individual schizophrenia patients (and healthy donors) significantly varied from patient to patient, but the activity of IgGs from healthy donors is on average 15.8-fold lower than that for schizophrenia patients. After extensive dialysis of purified IgGs against EDTA chelating metal ions, the relative catalase activity of IgGs decreases on average approximately 2.5-3.7-fold; all IgGs possess metal-dependent and independent catalase activity. The addition of external Me2+ ions to dialyzed and non-dialyzed IgGs leads to a significant increase in their activity. The best activator of dialyzed and non-dialyzed IgGs is Co2+, the activation by Cu2+, Mn2+, and Ni2+ ions were rare and always lower than by Co2+. Every IgG preparation demonstrates several individual sets of very well expressed pH optima in the pH range from 4.0 to 9.5. These data speak for the individual repertoire of catalase IgGs in every person and an extreme diversity of abzymes in their pH optima and activation by different metal ions. It is known that antioxidant enzymes such as superoxide dismutases, catalases, and glutathione peroxidases represent critical defense mechanisms preventing oxidative modifications of DNA, proteins, and lipids. Catalase activity of human IgGs could probably also play a major role in the protection of organisms from oxidative stress and toxic compounds.

Intraperitoneally administered IgG from patients with amyotrophic lateral sclerosis or from an immune-mediated goat model increase the levels of TNF-α, IL-6, and IL-10 in the spinal cord and serum of mice.

PubMed

Obál, Izabella; Klausz, Gergely; Mándi, Yvette; Deli, Mária; Siklós, László; Engelhardt, József I

2016-05-24

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that involves the selective loss of the upper and lower motor neurons (MNs). Neuroinflammation has been implicated in the pathogenesis of the sporadic form of the disease. We earlier developed immune-mediated animal models of ALS and demonstrated humoral and cellular immune reactions in the nervous system and in the sera of patients and animals. The accumulation of immunoglobulin G (IgG), an elevated intracellular level of calcium, ultrastructural alterations in the MNs, and activation of the microglia were noted in the spinal cord of ALS patients. Similar alterations developed in mice inoculated intraperitoneally with IgG from ALS patients or from an immune-mediated goat model. We have now examined whether the intraperitoneal injection of mice with IgG from sporadic ALS patients or from immunized goats with the homogenate of the anterior horn of the bovine spinal cord is associated with changes in the pro-inflammatory (TNF-α and IL-6) and anti-inflammatory (IL-10) cytokines in the spinal cord and serum of the mice. The levels of cytokines were measured by ELISA. Intraperitoneally administered IgG from the ALS patients induced subclinical signs of MN disease, while the injection of IgG from immunized goats resulted in a severe respiratory dysfunction and limb paralysis 24 h after the injections. Significantly increased levels of TNF-α and IL-10 were detected in the spinal cord of the mice injected with the human ALS IgG. The level of IL-6 increased primarily in the serum. The IgG from the immunized goats induced highly significant increases in the levels of all three cytokines in the serum and the spinal cord of mice. Our earlier experiments had proved that when ALS IgG or IgG from immune-mediated animal models was inoculated into mice, it was taken up in the MNs and had the ability to initiate damage in them. The pathological process was paralleled by microglia recruitment and activation in the spinal cord. The present experiment revealed that these forms of IgG cause significant increases in certain cytokine levels locally in the spinal cord and in the serum of the inoculated mice. These results suggest that IgG directed to the MNs may be an initial element in the damage to the MNs both in human ALS and in its immune-mediated animal models.

Clinical usefulness of Western blotting and ELISA avidity for the diagnosis of human toxocariasis.

PubMed

Rudzińska, M; Kowalewska, B; Sikorska, K

2017-01-01

The serodiagnosis of human toxocariasis is difficult. Specific IgGs detected routinely with ELISA based on Toxocara excretory-secretory (TES) antigens often persist for years at an elevated level, which does not allow either the differentiation between an active and persistent infection or monitoring of the effect of treatment. Additionally, false-positive results may occur in co-infections with other helminths due to cross-reactions. We evaluated the usefulness of an IgG avidity index (AI) and a Western blotting (WB) IgG in the diagnosis of patients suspected of Toxocara infection. We studied 138 subjects who were submitted to serological testing two or more times. Confirmation of an infection by WB was achieved in 73.2% of patients. A high AI was obtained in 89.1% of patients, and low AI and borderline AI were found in only 10.9%. Low and borderline values of AI remained at similar levels in subsequent studies over 2-3 years. The results showed the necessity of obligatory verification of all ELISA IgG positive and questionable results by WB. The index of IgG avidity may be helpful in excluding recent infection, but its usefulness in detecting an active phase of invasion requires further research. © 2016 John Wiley & Sons Ltd.

Increased levels of galactose-deficient IgG in sera of HIV-1-infected individuals.

PubMed

Moore, Jennifer S; Wu, Xueling; Kulhavy, Rose; Tomana, Milan; Novak, Jan; Moldoveanu, Zina; Brown, Rhubell; Goepfert, Paul A; Mestecky, Jiri

2005-03-04

The IgG from sera of patients with chronic inflammatory diseases of autoimmune character or some chronic microbial infections is frequently deficient in galactose on N-linked glycans. However, this phenomenon has not been investigated at length in human viral infections. To evaluate the glycosylation of serum IgG in HIV-1-positive patients. Psathyrella velutina lectin was used in enzyme-linked immunosorbent and Western blot assays to determine glycosylation. In addition, gas-liquid chromatography and mass spectrometry were utilized to confirm the galactose deficiency observed in the lectin-binding assays. HIV-1-infected individuals had significantly higher levels of galactose-deficient IgG than healthy controls. In fact, the galactose deficiency of the N-linked glycans observed in other diseases was even more profound in HIV-1 infection. This deficiency was primarily restricted to IgG when total serum glycoproteins were evaluated and IgG1 was the subclass most affected in all patients. Also, a significant increase in lectin binding was observed on IgG2 and IgG4 from HIV-1-positive females compared with HIV-1-negative females. Identification of deficient galactosylation of serum IgG from HIV-1-infected patients extended the spectrum of diseases in which this phenomenon has been observed. In addition, the results suggest yet another aspect of immune dysfunction as a result of HIV-1 infection.

A methodological approach for production and purification of polyclonal antibody against dog IgG.

PubMed

Sadeghi, Somayeh; Aghebati-Maleki, Leili; Nozari, Samira; Majidi, Jafar

2018-01-01

Antibodies are a class of biomolecules that has an important role in the immune system and lots of applications in biotechnological methods and in pharmaceutics. Production and purification of antibodies in laboratory animals is one of the first ways to manufacture of these prominent tools. The obtained antibodies from these process could be used in various types of bioassay techniques such as enzyme linked immunosorbent assay (ELISA), radioimmunoassay, etc. Also, antibodies employed in diagnostics applications in humans and other animals in order to detect specific antigens. In this study, we aimed to produce and purify anti-dog IgG via immunizing rabbits with dog IgG in combination with Freund's adjuvant. Polyclonal IgG were purified by ion exchange chromatography and then the purified antibody was labeled with horse radish peroxidase (HPR). Direct ELISA was used to determine the optimum titer and cross-reactivity of HRP conjugated IgG. The purity of various IgG preparations and the optimum dilution of prepared HRP conjugated IgG, respectively, was about 95.00% and 1:8000. This study showed that efficiency ion-exchange chromatography could be an appropriate method for purification of IgG antibodies. This antibody could be a useful tool for future dog immune diagnosis tests. This product characterization shown here sets the foundations for future work on dog IgGs.

Seroprevalence of dengue IgG antibodies in symptomatic and asymptomatic individuals three years after an outbreak in Zhejiang Province, China.

PubMed

Luo, Shuying; Cui, Weihong; Li, Chan; Ling, Feng; Fu, Tao; Liu, Qiyong; Ren, Jiangping; Sun, Jimin

2018-02-23

Cross-reacting antibodies enhanced dengue infection in humans and antibody dependent enhancement (ADE) have been proposed as early mechanisms underlying DHF/DSS. However, the duration of dengue IgG antibodies in the body as well as factors associated with said duration remain unclear. Blood samples from 59 dengue symptomatic persons and 48 asymptomatic individuals were collected. Study participant demographic information (including age in 2009, gender, and place of residence) were also collected. Serum samples were tested for dengue specific IgG by Panbio dengue IgG indirect enzyme-linked immunosorbent assay (ELISA). Chi-square tests and logistic regression analysis of dengue IgG antibodies seroprevalence divided by gender, age groups, and symptomatic or asymptomatic infection were conducted using the Statistical Package for the Social Sciences. Overall, 70 (65.42%) blood samples were seropositive for dengue IgG antibodies with similar seroprevalences found when dividing by gender and different age groups. However, seroprevalence of dengue IgG antibodies in samples from dengue symptomatic persons was significantly higher than that in samples from asymptomatic individuals (96.61% vs 27.08%) according to multivariable logistic regression analysis, the odds ratio (OR) of the factor was 76.731. Dengue IgG antibodies were detectable in samples from most individuals three years after infection. Dengue symptomatic persons had a higher dengue IgG prevalence compared to asymptomatic individuals.

Peroxynitrite-induced structural perturbations in human IgG: A physicochemical study.

PubMed

Arfat, Mir Yasir; Arif, Zarina; Chaturvedi, Sumit Kumar; Moinuddin; Alam, Khursheed

2016-08-01

IgG is an important defence protein. To exhibit optimum function the molecule must maintain its native structure. Peroxynitrite is a potent oxidizing and nitrating agent produced in vivo under pathophysiological conditions. It can oxidize and/or nitrate various amino acids causing changes in the structure and function of proteins. Such proteins may be involved in the pathogenesis of many inflammatory diseases, including rheumatoid arthritis. In the present work, peroxynitrite-induced structural changes in IgG have been studied by UV-visible, fluorescence, CD, FT-IR, DLS spectroscopy and DSC as well as by SDS-PAGE. Peroxynitrite-modified IgG exhibited hyperchromicity at 280 nm, quenching of tryptophan fluorescence, increase in ANS fluorescence, loss of β-sheet, shift in the positions of amide I and amide II bands, appearance of new peak in FT-IR, attachment of nitro residues and increase in melting temperature, compared to native IgG. Furthermore, peroxynitrite-modified IgG exhibited an additional peak at 420 nm, quenching in tyrosine fluorescence and enhancement in dityrosine fluorescence compared to native IgG. Generation of nitrotyrosine, dityrosine and nitrotryptophan was also observed in peroxynitrite-modified IgG. Gross structural changes in IgG caused by peroxynitrite and observed in vitro may favour autoantibodies induction in vivo under similar conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

Uncoupling GP1 and GP2 Expression in the Lassa Virus Glycoprotein Complex: Implications for GP1 Ectodomain Shedding

DTIC Science & Technology

2008-12-23

glycoprotein precursor (GPC) signal peptide (SP) or human IgG signal sequences (s.s.). GP2 was secreted from cells only when (1) the transmembrane (TM) domain... peptide (SP) or human IgG signal sequences (s.s.). GP2 was secreted from cells only when (1) the transmembrane (TM) domain was deleted, the...terminal signal peptide (SP), which directs the precursor to the endoplasmic retic- ulum (ER) for further processing [11]. The SP, which has been

Expression of human FcgammaRIIIa as a GPI-linked molecule on CHO cells to enable measurement of human IgG binding.

PubMed

Armour, Kathryn L; Smith, Cheryl S; Clark, Michael R

2010-03-31

The efficacy of a therapeutic IgG molecule may be as dependent on the optimisation of the constant region to suit its intended indication as on the selection of its variable regions. A crucial effector function to be maximised or minimised is antibody-dependent cell-mediated cytotoxicity by natural killer cells. Traditional assays of ADCC activity suffer from considerable inter-donor and intra-donor variability, which makes the measurement of antibody binding to human FcgammaRIIIa, the key receptor for ADCC, an attractive alternative method of assessment. Here, we describe the development of cell lines and assays for this purpose. The transmembrane receptor, FcgammaRIIIa, requires co-expression with signal transducing subunits to prevent its degradation, unlike the homologous receptor FcgammaRIIIb that is expressed as a GPI-anchored molecule. Therefore, to simplify the production of cell lines as reliable assay components, we expressed FcgammaRIIIa as a GPI-anchored molecule. Separate, stable CHO cell lines that express either the 158F or the higher-affinity 158V allotype of FcgammaRIIIa were isolated using fluorescence-activated cell sorting. The identities of the expressed receptors were confirmed using a panel of monoclonal antibodies that distinguish between subclasses and allotypes of FcgammaRIII and the cell lines were shown to have slightly higher levels of receptor than FcgammaRIII-positive peripheral blood mononuclear cells. Because the affinity of FcgammaRIIIa for IgG is intermediate amongst the receptors that bind IgG, we were able to use these cell lines to develop flow cytometric assays to measure the binding of both complexed and monomeric immunoglobulin. Thus, by choosing the appropriate method, weakly- or strongly-binding IgG can be efficiently compared. We have quantified the difference in the binding of wildtype IgG1 and IgG3 molecules to the two functional allotypes of the receptor and report that the FcgammaRIIIa-158V-antibody interaction is 3- to 4-fold stronger that the interaction with FcgammaRIIIa-158F. Overall, these robust assays should be valuable for batch-testing clinical material as well as providing tools for improving the design of therapeutic IgG. 2010 Elsevier B.V. All rights reserved.

Significance of immunoglobulin G4 (IgG4)-positive cells in extrahepatic cholangiocarcinoma: molecular mechanism of IgG4 reaction in cancer tissue.

PubMed

Harada, Kenichi; Shimoda, Shinji; Kimura, Yasushi; Sato, Yasunori; Ikeda, Hiroko; Igarashi, Saya; Ren, Xiang-Shan; Sato, Hirohide; Nakanuma, Yasuni

2012-07-01

IgG4 reactions consisting of marked infiltration by immunoglobulin G4 (IgG4)-positive plasma cells in affected organs is found in cancer patients as well as patients with IgG4-related diseases. Notably, extrahepatic cholangiocarcinomas accompanying marked IgG4 reactions clinicopathologically mimic IgG4-related sclerosing cholangitis. The regulatory cytokine interleukin (IL)-10 is thought to induce the differentiation of IgG4-positive cells. In this study, to clarify the mechanism of the IgG4 reaction in extrahepatic cholangiocarcinoma, we investigated nonprofessional antigen-presenting cells (APCs) generating IL-10-producing regulatory T cells (anergy T cells) and Foxp3-positive regulatory cells producing IL-10. Immunohistochemistry targeting IgG4, HLA-DR, CD80, CD86, and Foxp3 was performed using 54 cholangiocarcinoma specimens from 24 patients with gallbladder cancer, 22 patients with common bile duct cancer, and eight patients with cancer of the Papilla of Vater. Moreover, a molecular analysis of Foxp3 and IL-10 was performed using a cultured human cholangiocarcinoma cell line. Consequently, 43% of the cholangiocarcinomas were found to be abundant in IgG4. Those expressing HLA-DR but lacking costimulatory molecules (CD80 and CD86) and those expressing Foxp3 detected by an antibody recognizing the N terminus accounted for 54% and 39% of cases, respectively. Moreover, the number of IgG4-positive cells was larger in these cases than in other groups. In cultured cells, the presence of a splicing variant of Foxp3 messenger RNA and the expression of IL-10 were demonstrated. Extrahepatic cholangiocarcinoma is often accompanied by significant infiltration of IgG4-positive cells. Cholangiocarcinoma cells could play the role of nonprofessional APCs and Foxp3-positive regulatory cells, inducing IgG4 reactions via the production of IL-10 indirectly and directly, respectively. Copyright © 2012 American Association for the Study of Liver Diseases.

CCR7(lo)PD-1(hi) CXCR5(+) CD4(+) T cells are positively correlated with levels of IL-21 in active and transitional cystic echinococcosis patients.

PubMed

Zhang, Fengbo; Pang, Nannan; Zhu, Yuejie; Zhou, Dexian; Zhao, Hui; Hu, Jinwei; Ma, Xiumin; Li, Jun; Wen, Hao; Samten, Buka; Fan, Haining; Ding, Jianbing

2015-10-26

In our study, we investigated whether circulating T follicular helper (Tfh) and the related cytokines are involved in human cystic echinococcosis (CE). A total of 64 patients with CE and 30 healthy controls were enrolled in this study. Percentages of CCR7(lo)PD-1(hi) cells within CXCR5(+) CD4(+) T cells (circulating Tfh cells) were detected by flow cytometry. Levels of IL-21 and IL-4 in peripheral blood were detected by cytometric bead array. The mRNA expression of IL-21, IL-4, Bcl-6, and Blimp-1 in peripheral blood mononuclear cells (PBMCs) were measured by real-time PCR. Levels of IgG1, IgG2, IgG3, and IgG4 in the patients' sera were measured using enzyme-linked immunosorbent assay. Percentages of circulating Tfh cells were significantly increased in the CE1, CE2, and CE3 groups (p < 0.05). The concentrations of IL-21 and IL-4 in the serum were significantly increased in CE1, CE2, and CE3 groups (p < 0.05). IL-21 was positively correlated with circulating Tfh cells in CE3 group (r = 0.779, p < 0.05). The mRNA levels of IL-21, IL-4, and Bcl-6 were increased in CE1, CE2, and CE3 groups. Levels of IgG1 and IgG4 in patients' sera were increased in CE1, CE2, and CE3 groups. Levels of IgG2 and IgG3 were increased in CE4-5 group. Additionally, after stimulation with hydatid fluid in vitro, the levels of circulating Tfh cells, IL-21 and IL-4 in PBMCs isolated from CE patients were significantly increased (p < 0.05). The levels of circulating Tfh and related cytokines were significantly increased in CE patients, suggesting that they are involved in human CE.

Scarcity of autoreactive human blood IgA+ memory B cells

PubMed Central

Prigent, Julie; Lorin, Valérie; Kök, Ayrin; Hieu, Thierry; Bourgeau, Salomé

2016-01-01

Class‐switched memory B cells are key components of the “reactive” humoral immunity, which ensures a fast and massive secretion of high‐affinity antigen‐specific antibodies upon antigenic challenge. In humans, IgA class‐switched (IgA+) memory B cells and IgA antibodies are abundant in the blood. Although circulating IgA+ memory B cells and their corresponding secreted immunoglobulins likely possess major protective and/or regulatory immune roles, little is known about their specificity and function. Here, we show that IgA+ and IgG+ memory B‐cell antibodies cloned from the same healthy humans share common immunoglobulin gene features. IgA and IgG memory antibodies have comparable lack of reactivity to vaccines, common mucosa‐tropic viruses and commensal bacteria. However, the IgA+ memory B‐cell compartment contains fewer polyreactive clones and importantly, only rare self‐reactive clones compared to IgG+ memory B cells. Self‐reactivity of IgAs is acquired following B‐cell affinity maturation but not antibody class switching. Together, our data suggest the existence of different regulatory mechanisms for removing autoreactive clones from the IgG+ and IgA+ memory B‐cell repertoires, and/or different maturation pathways potentially reflecting the distinct nature and localization of the cognate antigens recognized by individual B‐cell populations. PMID:27469325

Polydimethylsiloxane microfluidic chemiluminescence immunodevice with the signal amplification strategy for sensitive detection of human immunoglobin G.

PubMed

Li, Huifang; Zhao, Mei; Liu, Wei; Chu, Weiru; Guo, Yumei

2016-01-15

A polydimethylsiloxane (PDMS) microfluidic chemiluminescence (CL) immunodevice for sensitive detection of human immunoglobin G (IgG) with the signal amplification strategy was developed in this work. The immunodevice was prepared by covalently immobilizing capture antibodies (Abs) on the silanized microchannel of microfluidic chip. Gold nanoparticles (AuNPs) functionalized with a high molar ratio of horseradish peroxidase (HRP) were used as an Ab label for signal amplification. Using a sandwich immunoassay, the multi-HRP conjugated AuNPs can catalyze the luminol-H2O2 CL system to achieve the high sensitivity. In addition, the double spiral flow-channel was adopted here, which can still contribute to the high sensitivity. Based on signal amplification strategy, the performance of human IgG tests revealed a lower detection limit (DL) of 0.03ng/mL and showed an increase of 7.4-fold in detection sensitivity compared to a commercial Ab-HRP conjugation. This microfluidic immunodevice can provide an alternative approach for sensitive detection of human IgG in the field of clinic diagnostic and therapeutic. Copyright © 2015 Elsevier B.V. All rights reserved.

Clinical-pathologic correlations in voltage-gated Kv1 potassium channel complex-subtyped autoimmune painful polyneuropathy.

PubMed

Lahoria, Rajat; Pittock, Sean J; Gadoth, Avi; Engelstad, Janean K; Lennon, Vanda A; Klein, Christopher J

2017-04-01

Voltage-gated Kv1 potassium channel complex (VGKC) autoantibodies subtyped for leucine-rich glioma-inactivated 1 (LGI1), contactin-associated-proteinlike 2 (CASPR2), and Kv IgGs have a spectrum of neurological presentations. Painful polyneuropathy is seen in some patients, but nerve pathology descriptions are lacking. Clinicopathologic features were studied in subtyped VGKC-autoantibody-seropositive patients who had undergone nerve biopsies. Five patients were identified, 1 LGI1 IgG positive and 1 CASPR2 IgG positive, but all negative for Kv1.1-, 1.2-, 1.6-subtyped IgG autoantibodies. Median symptom duration was 17 months. Pain was the predominant symptom; 3 had mild sensory loss and/or weakness. Histopathological abnormalities were limited to axonal loss in 3. None had mononuclear cellular infiltrates. Electron micrographs revealed no interstitial abnormalities. Three patients reported marked improvement in pain with immunotherapy. The nerve biopsy histopathology of patients subtyped for LGI1 and CASPR2 IgGs within the VGKC-complex spectrum disorders shows either normal density or axonal fiber loss without inflammatory infiltrates. A reversible neural hyperexcitable mechanism is considered to be the cause of this painful polyneuropathy. Muscle Nerve 55: 520-525, 2017. © 2016 Wiley Periodicals, Inc.

LASIC: Light Activated Site-Specific Conjugation of Native IgGs.

PubMed

Hui, James Z; Tamsen, Shereen; Song, Yang; Tsourkas, Andrew

2015-08-19

Numerous biological applications, from diagnostic assays to immunotherapies, rely on the use of antibody-conjugates. The efficacy of these conjugates can be significantly influenced by the site at which Immunoglobulin G (IgG) is modified. Current methods that provide control over the conjugation site, however, suffer from a number of shortfalls and often require large investments of time and cost. We have developed a novel adapter protein that, when activated by long wavelength UV light, can covalently and site-specifically label the Fc region of nearly any native, full-length IgG, including all human IgG subclasses. Labeling occurs with unprecedented efficiency and speed (>90% after 30 min), with no effect on IgG affinity. The adapter domain can be bacterially expressed and customized to contain a variety of moieties (e.g., biotin, azide, fluorophores), making reliable and efficient conjugation of antibodies widely accessible to researchers at large.

Design and construction of immune phage antibody library against Tetanus neurotoxin: Production of single chain antibody fragments.

PubMed

Sadreddini, Sanam; Seifi-Najmi, Mehrnosh; Ghasemi, Babollah; Kafil, Hossein Samadi; Alinejad, Vahideh; Sadreddini, Sevil; Younesi, Vahid; Jadidi-Niaragh, Farhad; Yousefi, Mehdi

2015-12-23

Tetanus neurotoxin (TeNT) is composed of a light (LC) and heavy chain (HC) polypeptides, released by anaerobic bacterium Clostridium tetani and can cause fatal life-threatening infectious disease. Toxin HC and LC modules represents receptor binding and zinc metalloprotease activity, respectively. The passive administration of animal-derived antibodies against tetanus toxin has been considered as the mainstay therapy for years. However, this treatment is associated with several adverse effects due to the presence of anti-isotype antibodies. In the present study, we have produced the fully human single chain antibody fragments (HuScFv) from two human antibody phage display libraries. Twenty-four different HuscFvs were isolated from two anti TeNT immune libraries. Our produced human ScFv (HuScFv) were converted to IgG platform and analyzed regarding their specific reactivity to TeNT. All of the selected scFvs have the same VL but different VH. Three HuscFvs from the first library (TTX15, 51, 75) and two HuscFvs from the second library (TTX16, 20) were chosen to convert to IgG1 using pOptiVEC and pcDNA3.3 systems. Production of IgG1 from transfected DG44 and binding capacity of them to tetanus toxin and toxoid were measured by ELISA. ELISA results showed no detectable production of TTX16 and TTX20 IgG1. Although, TTX51 and TTX75 were converted and produced as IgG1, no reactivity to tetanus toxin and toxoid was observed. However, TTX15 was successfully produced as whole IgG1 platform with reactivity to both tetanus toxin and toxoid. The latter would be an appropriate replacement for conventional polyclonal antibodies if would meet the further characterization including specificity determination, affinity measurement and toxin neutralizing assays. Our results demonstrated production of functional IgG1 derived from TTX15 scFv and might be an appropriate replacement for polyclonal Tetabulin but it needs further characterization.

The in vitro MIMIC® platform reflects age-associated changes in immunological responses after influenza vaccination.

PubMed

Dauner, Allison; Agrawal, Pankaj; Salvatico, Jose; Tapia, Tenekua; Dhir, Vipra; Shaik, S Farzana; Drake, Donald R; Byers, Anthony M

2017-10-04

Increasing research and development costs coupled with growing concerns over healthcare expenditures necessitate the generation of pre-clinical testing models better able to predict the efficacy of vaccines, drugs and biologics. An ideal system for evaluating vaccine immunogenicity will not only be reliable but also physiologically relevant, able to be influenced by immunomodulatory characteristics such as age or previous exposure to pathogens. We have previously described a fully autologous human cell-based MIMIC® (Modular IMmune In vitro Construct) platform which enables the evaluation of innate and adaptive immunity in vitro, including naïve and recall responses. Here, we establish the ability of this module to display reduced antibody production and T cell activation upon in vitro influenza vaccination of cells from elderly adults. In the MIMIC® system, we observe a 2.7-4.2-fold reduction in strain-specific IgG production to seasonal trivalent influenza vaccine (TIV) in the elderly when compared to adults, as well as an age-dependent decline in the generation of functional antibodies. A parallel decline in IgG production with increasing age was detected via short-term ex vivo stimulation of B cells after in vivo TIV vaccination in the same cohort. Using MIMIC®, we also detect a reduction in the number but not proportion of TIV-specific multifunctional CD154 + IFNγ + IL-2 + TNFα + CD4 + T cells in elderly adults. Inefficient induction of multifunctional helper T cells with TIV stimulation in MIMIC® despite a normalized number of initial CD4 + T cells suggests a possible mechanism for an impaired anti-TIV IgG response in elderly adults. The ability of the MIMIC® system to recapitulate differential age-associated responses in vitro provides a dynamic platform for the testing of vaccine candidates and vaccine enhancement strategies in a fully human model including the ability to interrogate specific populations, such as elderly adults. Copyright © 2017 Elsevier Ltd. All rights reserved.

Human T-cell responses to oral streptococci in human PBMC-NOD/SCID mice.

PubMed

Salam, M A; Nakao, R; Yonezawa, H; Watanabe, H; Senpuku, H

2006-06-01

We investigated cellular and humoral immune responses to oral biofilm bacteria, including Streptococcus mutans, Streptococcus anginosus, Streptococcus sobrinus, and Streptococcus sanguinis, in NOD/SCID mice immunized with human peripheral blood mononuclear cells (hu-PBMC-NOD/SCID mice) to explore the pathogenicity of each of those organisms in dental and oral inflammatory diseases. hu-PBMC-NOD/SCID mice were immunized by intraperitoneal injections with the whole cells of the streptococci once a week for 3 weeks. FACS analyses were used to determine the percentages of various hu-T cell types, as well as intracellular cytokine production of interleukin-4 and interferon-gamma. Serum IgG and IgM antibody levels in response to the streptococci were also determined by enzyme-linked immunosorbent assay. S. anginosus induced a significant amount of the proinflammatory cytokine interferon-gamma in CD4(+) and CD8(+) T cells in comparison with the other streptococci. However, there was no significant differences between the streptococci in interleukin-4 production by CD4(+) and CD8(+) T cells after inoculation. Further, S. mutans significantly induced human anti-S. mutans IgG, IgG(1), IgG(2), and IgM antibodies in comparison with the other organisms. In conclusion, S. anginosus up-regulated Th1 and Tc1 cells, and S. mutans led to increasing levels of their antibodies, which was associated with the induction of Th2 cells. These results may contribute to a better understanding of human lymphocyte interactions to biofilm bacteria, along with their impact on dental and mucosal inflammatory diseases, as well as endocarditis.

Induction of Scleroderma Fibrosis in Skin-Humanized Mice by Administration of Anti-Platelet-Derived Growth Factor Receptor Agonistic Autoantibodies.

PubMed

Luchetti, Michele M; Moroncini, Gianluca; Jose Escamez, Maria; Svegliati Baroni, Silvia; Spadoni, Tatiana; Grieco, Antonella; Paolini, Chiara; Funaro, Ada; Avvedimento, Enrico V; Larcher, Fernando; Del Rio, Marcela; Gabrielli, Armando

2016-09-01

To describe a skin-SCID mouse chimeric model of systemic sclerosis (SSc; scleroderma) fibrosis based on engraftment of ex vivo-bioengineered skin using skin cells derived either from scleroderma patients or from healthy donors. Three-dimensional bioengineered skin containing human keratinocytes and fibroblasts isolated from skin biopsy specimens from healthy donors or SSc patients was generated ex vivo and then grafted onto the backs of SCID mice. The features of the skin grafts were analyzed by immunohistochemistry, and the functional profile of the graft fibroblasts was defined before and after treatment with IgG from healthy controls or SSc patients. Two procedures were used to investigate the involvement of platelet-derived growth factor receptor (PDGFR): 1) nilotinib, a tyrosine kinase inhibitor, was administered to mice before injection of IgG from SSc patient sera (SSc IgG) into the grafts, and 2) human anti-PDGFR monoclonal antibodies were injected into the grafts. Depending on the type of bioengineered skin grafted, the regenerated human skin exhibited either the typical scleroderma phenotype or the healthy human skin architecture. Treatment of animals carrying healthy donor skin grafts with SSc IgG resulted in the appearance of a bona fide scleroderma phenotype, as confirmed by increased collagen deposition and fibroblast activation markers. Results of the experiments involving administration of nilotinib or monoclonal antibodies confirmed the involvement of PDGFR. Our results provide the first in vivo demonstration of the fibrotic properties of anti-PDGFR agonistic antibodies. This bioengineered skin-humanized mouse model can be used to test in vivo the progression of the disease and to monitor response to antifibrotic drugs. © 2016, American College of Rheumatology.

Serosurvey of Crimean-Congo hemorrhagic fever virus in domestic animals, Gujarat, India, 2013.

PubMed

Mourya, Devendra T; Yadav, Pragya D; Shete, Anita; Majumdar, Triparna D; Kanani, Amit; Kapadia, Dhirendra; Chandra, Vartika; Kachhiapatel, Anantdevesh J; Joshi, Pravinchandra T; Upadhyay, Kamalesh J; Dave, Paresh; Raval, Dinkar

2014-09-01

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne viral disease that causes a fatal hemorrhagic illness in humans. This disease is asymptomatic in animals. CCHF was first confirmed in a nosocomial outbreak in 2011 in Gujarat State. Another notifiable outbreak occurred in July, 2013, in Karyana Village, Amreli district, Gujarat State. Anti-CCHF virus (CCHFV) immunoglobulin G (IgG) antibodies were detected in domestic animals from the adjoining villages of the affected area, indicating a considerable amount of positivity against domestic animals. The present serosurvey was carried out to determine the prevalence of CCHFV among bovine, sheep, and goat populations from 15 districts of Gujarat State, India. A total of 1226 serum samples from domestic animals were screened for IgG antibodies using a CCHF animal IgG enzyme-linked immunosorbent assay (ELISA) kit from the Centers for Disease Control and Prevention. Antibodies were detected in all the 15 districts surveyed; with positivity of 12.09%, 41.21%, and 33.62% in bovine, sheep, and goat respectively. This necessitates the surveillance of CCHFV IgG antibodies in animals and hemorrhagic fever cases in human.

In vivo trafficking and catabolism of IgG1 antibodies with Fc associated carbohydrates of differing structure.

PubMed

Wright, A; Sato, Y; Okada, T; Chang, K; Endo, T; Morrison, S

2000-12-01

We have now produced mouse-human chimeric IgG1 in wild-type Chinese hamster ovary (CHO) cell lines Pro-5 as well as in the glycosylation mutants Lec 2, Lec 8, and Lec 1. Analysis of the attached carbohydrates shows those present on IgG1-Lec 1 were mannose terminated. Carbohydrate present on IgG1-Lec8 was uniformly biantennary terminating in N-acetylglucosamine. The glycosylation profiles of IgG1-Lec 2 and IgG1-Pro-5 were heterogeneous. Only IgG1-Pro-5 was sialylated with sialic acid present on only a small percentage of the carbohydrate structures. When the in vivo fate of antibodies labeled with (125)I-lactotyramine was determined, it was found that the majority of all of the antibodies, irrespective of the structure of their attached carbohydrate, is catabolized in the skin and muscle. However, the attached carbohydrate structure does influence the amount that is catabolized in the liver and the liver serves as a major site for the catabolism of proteins bearing carbohydrate with the Lec2 (with terminal galactose) or Lec1(with terminal mannose) structure.

Acid-induced aggregation propensity of nivolumab is dependent on the Fc

PubMed Central

Liu, Boning; Guo, Huaizu; Xu, Jin; Qin, Ting; Xu, Lu; Zhang, Junjie; Guo, Qingcheng; Zhang, Dapeng; Qian, Weizhu; Li, Bohua; Dai, Jianxin; Hou, Sheng; Guo, Yajun; Wang, Hao

2016-01-01

ABSTRACT Nivolumab, an anti-programmed death (PD)1 IgG4 antibody, has shown notable success as a cancer treatment. Here, we report that nivolumab was susceptible to aggregation during manufacturing, particularly in routine purification steps. Our experimental results showed that exposure to low pH caused aggregation of nivolumab, and the Fc was primarily responsible for an acid-induced unfolding phenomenon. To compare the intrinsic propensity of acid-induced aggregation for other IgGs subclasses, tocilizumab (IgG1), panitumumab (IgG2) and atezolizumab (aglyco-IgG1) were also investigated. The accurate pH threshold of acid-induced aggregation for individual IgG Fc subclasses was identified and ranked as: IgG1 < aglyco-IgG1 < IgG2 < IgG4. This result was cross-validated by thermostability and conformation analysis. We also assessed the effect of several protein stabilizers on nivolumab, and found mannitol ameliorated the acid-induced aggregation of the molecule. Our results provide valuable insight into downstream manufacturing process development, especially for immune checkpoint modulating molecules with a human IgG4 backbone. PMID:27310175

Anti-dengue virus envelope protein domain III IgG ELISA among infants with primary dengue virus infections.

PubMed

Libraty, Daniel H; Zhang, Lei; Obcena, AnaMae; Brion, Job D; Capeding, Rosario Z

2015-02-01

Dengue is the most prevalent arthropod-borne viral illness in humans. The current gold standard serologic test for dengue virus (DENV) infection is a neutralizing antibody assay. We examined a DENV recombinant (r)E protein domain III IgG ELISA among infants with primary DENV infections. Infants experience a primary DENV infection in the presence of maternally derived anti-DENV IgG. The estimated DENV rE protein domain III IgG levels to the infecting serotype at the time of infant primary symptomatic DENV2 and DENV3 infections correlated with the 50% plaque reduction neutralization reciprocal antibody titers (PRNT50). Anti-DENVs 1-4 rE protein domain III IgG levels all correlated with each other, and the estimated rE protein domain III IgG level to the infecting serotype at the time of infection inversely correlated with dengue disease severity. The anti-DENV rE protein domain III IgG ELISA may be a useful and potentially high-throughput alternative to traditional DENV neutralizing antibody assays. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

First report of real-time monitoring of coagulation function potential and IgG subtype of anti-FVIII autoantibodies in a child with acquired hemophilia A associated with streptococcal infection and amoxicillin.

PubMed

Takeyama, Masahiro; Nogami, Keiji; Kajimoto, Takahiro; Ogiwara, Kenichi; Matsumoto, Tomoko; Shima, Midori

2018-01-01

We describe an 8-year-old boy with acquired hemophilia A (AHA) associated with streptococcal infection and amoxicillin. Laboratory data revealed low factor VIII activity (FVIII:C, 1.5 IU/dl), and FVIII inhibitor (15.9 BU/ml). Comprehensive coagulation function assays, including rotation thromboelastometry (ROTEM ® ), revealed a markedly prolonged clotting time. Thrombin and plasmin generation (TG/PG) appeared to be moderately impaired. The inhibitor epitope of his anti-FVIII autoantibody recognized light and heavy chains. He was treated with Novoseven ® and prednisolone, resulting in rapid improvement. ROTEM showed the return of coagulation time to normal level on day 20, and TG gradually improved. PG was moderately reduced in the clinical early phase, but improved at day 20. The patient's IgG subtype was IgG 4 at onset. IgG 1 was transiently positive on day 20, but negative on day 46. FVIII inhibitor gradually decreased and was completely absent after day 46, along with the elevated FVIII:C. IgG4 was again elevated on day 83, followed by a rapid decrease, indicative of the presence of non-neutralizing antibody, which remains currently undetected. We for the first time report changes in comprehensive coagulation function and IgG subtype of anti-FVIII antibody in a rare pediatric case of AHA.

Dexamethasone attenuates oxidation of extracellular matrix proteins by human monocytes.

PubMed

Ahmed, Shahid; Adamidis, Ananea; Jan, Louis C; Gibbons, Nora; Mattana, Joseph

2003-10-01

In response to infection or in immune complex-mediated diseases, inflammatory cells may oxidatively damage extracellular matrix (ECM) proteins. In this study we evaluated whether human monocytes could oxidize ECM and whether this could be modulated by exposure to LPS, IgG complexes, and dexamethasone (DEX). Wells in tissue culture plates were coated with the ECM preparation Matrigel. Porous inserts with or without the human monocyte cell line THP-1 were placed into ECM-containing wells and cells were exposed to control conditions or to LPS (10 ng/ml), IgG complexes (200 and 500 microg/ml), or DEX (10(-7) and 10(-6) M). ECM was then subjected to Western blot analysis using an antibody to oxidized protein. In addition, Western blot analysis was carried out on DEX-treated cells to evaluate expression of the NADPH oxidase components p67-phox and gp91-phox. THP-1 cells enhanced ECM oxidation and this effect was augmented by LPS and by IgG aggregates. Preincubation of cells with DEX attenuated ECM oxidation and was also associated with decreased expression of p67-phox and gp91-phox. These findings suggest that human monocytes can oxidize ECM proteins and that this may be modulated by IgG complexes and LPS. Dexamethasone appears to attenuate ECM oxidation and a better understanding of this mechanism might allow for interventions to minimize oxidative damage to ECM proteins by monocytes in infectious and inflammatory states.

Human Antibody Responses to the Anopheles Salivary gSG6-P1 Peptide: A Novel Tool for Evaluating the Efficacy of ITNs in Malaria Vector Control

PubMed Central

Drame, Papa Makhtar; Poinsignon, Anne; Besnard, Patrick; Cornelie, Sylvie; Le Mire, Jacques; Toto, Jean-Claude; Foumane, Vincent; Dos-Santos, Maria Adelaide; Sembène, Mbacké; Fortes, Filomeno; Simondon, Francois; Carnevale, Pierre; Remoue, Franck

2010-01-01

To optimize malaria control, WHO has prioritised the need for new indicators to evaluate the efficacy of malaria vector control strategies. The gSG6-P1 peptide from gSG6 protein of Anopheles gambiae salivary glands was previously designed as a specific salivary sequence of malaria vector species. It was shown that the quantification of human antibody (Ab) responses to Anopheles salivary proteins in general and especially to the gSG6-P1 peptide was a pertinent biomarker of human exposure to Anopheles. The present objective was to validate this indicator in the evaluation of the efficacy of Insecticide Treated Nets (ITNs). A longitudinal evaluation, including parasitological, entomological and immunological assessments, was conducted on children and adults from a malaria-endemic area before and after the introduction of ITNs. Significant decrease of anti-gSG6-P1 IgG response was observed just after the efficient ITNs use. Interestingly, specific IgG Ab level was especially pertinent to evaluate a short-time period of ITNs efficacy and at individual level. However, specific IgG rose back up within four months as correct ITN use waned. IgG responses to one salivary peptide could constitute a reliable biomarker for the evaluation of ITN efficacy, at short- and long-term use, and provide a valuable tool in malaria vector control based on a real measurement of human-vector contact. PMID:21179476

Human antibody responses to the Anopheles salivary gSG6-P1 peptide: a novel tool for evaluating the efficacy of ITNs in malaria vector control.

PubMed

Drame, Papa Makhtar; Poinsignon, Anne; Besnard, Patrick; Cornelie, Sylvie; Le Mire, Jacques; Toto, Jean-Claude; Foumane, Vincent; Dos-Santos, Maria Adelaide; Sembène, Mbacké; Fortes, Filomeno; Simondon, Francois; Carnevale, Pierre; Remoue, Franck

2010-12-14

To optimize malaria control, WHO has prioritised the need for new indicators to evaluate the efficacy of malaria vector control strategies. The gSG6-P1 peptide from gSG6 protein of Anopheles gambiae salivary glands was previously designed as a specific salivary sequence of malaria vector species. It was shown that the quantification of human antibody (Ab) responses to Anopheles salivary proteins in general and especially to the gSG6-P1 peptide was a pertinent biomarker of human exposure to Anopheles. The present objective was to validate this indicator in the evaluation of the efficacy of Insecticide Treated Nets (ITNs). A longitudinal evaluation, including parasitological, entomological and immunological assessments, was conducted on children and adults from a malaria-endemic area before and after the introduction of ITNs. Significant decrease of anti-gSG6-P1 IgG response was observed just after the efficient ITNs use. Interestingly, specific IgG Ab level was especially pertinent to evaluate a short-time period of ITNs efficacy and at individual level. However, specific IgG rose back up within four months as correct ITN use waned. IgG responses to one salivary peptide could constitute a reliable biomarker for the evaluation of ITN efficacy, at short- and long-term use, and provide a valuable tool in malaria vector control based on a real measurement of human-vector contact.

Sudden onset unilateral sensorineural hearing loss after rabies vaccination.

PubMed

Okhovat, Saleh; Fox, Richard; Magill, Jennifer; Narula, Antony

2015-12-15

A 33-year-old man developed profound sudden onset right-sided hearing loss with tinnitus and vertigo, within 24 h of pretravel rabies vaccination. There was no history of upper respiratory tract infection, systemic illness, ototoxic medication or trauma, and normal otoscopic examination. Pure tone audiograms (PTA) demonstrated right-sided sensorineural hearing loss (thresholds 90-100 dB) and normal left-sided hearing. MRI internal acoustic meatus, viral serology (hepatitis B, C, HIV and cytomegalovirus) and syphilis screen were normal. Positive Epstein-Barr virus IgG, viral capsid IgG and anticochlear antibodies (anti-HSP-70) were noted. Initial treatment involved a course of high-dose oral prednisolone and acyclovir. Repeat PTAs after 12 days of treatment showed a small improvement in hearing thresholds. Salvage intratympanic steroid injections were attempted but failed to improve hearing further. Sudden onset sensorineural hearing loss (SSNHL) is an uncommon but frightening experience for patients. This is the first report of SSNHL following rabies immunisation in an adult. 2015 BMJ Publishing Group Ltd.

Evading pre-existing anti-hinge antibody binding by hinge engineering

PubMed Central

Kim, Hok Seon; Kim, Ingrid; Zheng, Linda; Vernes, Jean-Michel; Meng, Y. Gloria; Spiess, Christoph

2016-01-01

ABSTRACT Antigen-binding fragments (Fab) and F(ab′)2 antibodies serve as alternative formats to full-length anti-bodies in therapeutic and immune assays. They provide the advantage of small size, short serum half-life, and lack of effector function. Several proteases associated with invasive diseases are known to cleave antibodies in the hinge-region, and this results in anti-hinge antibodies (AHA) toward the neoepitopes. The AHA can act as surrogate Fc and reintroduce the properties of the Fc that are otherwise lacking in antibody fragments. While this response is desired during the natural process of fighting disease, it is commonly unwanted for therapeutic antibody fragments. In our study, we identify a truncation in the lower hinge region of the antibody that maintains efficient proteolytic cleavage by IdeS protease. The resulting neoepitope at the F(ab′)2 C-terminus does not have detectable binding of pre-existing AHA, providing a practical route to produce F(ab′)2 in vitro by proteolytic digestion when the binding of pre-existing AHA is undesired. We extend our studies to the upper hinge region of the antibody and provide a detailed analysis of the contribution of C-terminal residues of the upper hinge of human IgG1, IgG2 and IgG4 to pre-existing AHA reactivity in human serum. While no pre-existing antibodies are observed toward the Fab of IgG2 and IgG4 isotype, a significant response is observed toward most residues of the upper hinge of human IgG1. We identify a T225L variant and the natural C-terminal D221 as solutions with minimal serum reactivity. Our work now enables the production of Fab and F(ab′)2 for therapeutic and diagnostic immune assays that have minimal reactivity toward pre-existing AHA. PMID:27606571

The quantity and quality of α-gal-specific antibodies differ in individuals with and without delayed red meat allergy.

PubMed

Kollmann, D; Nagl, B; Ebner, C; Emminger, W; Wöhrl, S; Kitzmüller, C; Vrtala, S; Mangold, A; Ankersmit, H-J; Bohle, B

2017-02-01

IgG to galactose-α-1,3-galactose (α-gal) are highly abundant natural antibodies (Ab) in humans. α-Gal-specific IgE Ab cause a special form of meat allergy characterized by severe systemic reactions 3-7 h after consumption of red meat. We investigated 20 patients who experienced such reactions and characterized their α-gal-specific IgE and IgG responses in more detail. α-Gal-specific IgE was determined by ImmunoCAP. IgE reactivity to meat extract and bovine gamma globulin (BGG) was assessed by immunoblotting and ELISA, respectively. In some experiments, sera were pre-incubated with α-gal or protein G to deplete IgG Ab. α-Gal-specific IgG 1-4 Ab in individuals with and without meat allergy were assessed by ELISA. In immunoblots, BGG was the most frequently recognized meat protein. Binding of IgE and IgG to BGG was confirmed by ELISA and completely abolished after pre-incubation with α-gal. Neither the depletion of autologous α-gal-specific IgG Ab nor the addition of α-gal-specific IgG Ab from nonallergic individuals changed the IgE recognition of BGG of meat-allergic patients. Meat-allergic patients showed significantly higher α-gal-specific IgG1 and IgG3 Ab than nonallergic individuals, whereas the latter showed significantly higher levels of α-gal-specific IgG4 Ab. Patients with delayed meat allergy display IgE and IgG Ab that selectively recognize the α-gal epitope on BGG. Their enhanced α-gal-specific IgE levels are accompanied by high levels of α-gal-specific IgG1 devoid of IgE-blocking activity. This subclass distribution is atypical for food allergies and distinct from natural α-gal IgG responses in nonallergic individuals. © 2016 The Authors. Allergy Published by John Wiley & Sons Ltd.

Human IgG2- and IgG4-expressing memory B cells display enhanced molecular and phenotypic signs of maturity and accumulate with age.

PubMed

de Jong, Britt G; IJspeert, Hanna; Marques, Lemelinda; van der Burg, Mirjam; van Dongen, Jacques Jm; Loos, Bruno G; van Zelm, Menno C

2017-10-01

The mechanisms involved in sequential immunoglobulin G (IgG) class switching are still largely unknown. Sequential IG class switching is linked to higher levels of somatic hypermutation (SHM) in vivo, but it remains unclear if these are generated temporally during an immune response or upon activation in a secondary response. We here aimed to uncouple these processes and to distinguish memory B cells from primary and secondary immune responses. SHM levels and IgG subclasses were studied with 454 pyrosequencing on blood mononuclear cells from young children and adults as models for primary and secondary immunological memory. Additional sequencing and detailed immunophenotyping with IgG subclass-specific antibodies was performed on purified IgG + memory B-cell subsets. In both children and adults, SHM levels were higher in transcripts involving more downstream-located IGHG genes (esp. IGHG2 and IGHG4). In adults, SHM levels were significantly higher than in children, and downstream IGHG genes were more frequently utilized. This was associated with increased frequencies of CD27 + IgG + memory B cells, which contained higher levels of SHM, more IGHG2 usage, and higher expression levels of activation markers than CD27 - IgG + memory B cells. We conclude that secondary immunological memory accumulates with age and these memory B cells express CD27, high levels of activation markers, and carry high SHM levels and frequent usage of IGHG2. These new insights contribute to our understanding of sequential IgG subclass switching and show a potential relevance of using serum IgG2 levels or numbers of IgG2-expressing B cells as markers for efficient generation of memory responses.

Structural and immunological characterization of hydroxyl radical modified human IgG: Clinical correlation in rheumatoid arthritis

NASA Astrophysics Data System (ADS)

Islam, Sidra; Mir, Abdul Rouf; Arfat, Mir Yasir; Khan, Farzana; Zaman, Masihuz; Ali, Asif; Moinuddin

2018-04-01

Structural alterations in proteins under oxidative stress have been widely implicated in the immuno-pathology of various disorders. This study has evaluated the extent of damage in the conformational characteristics of IgG by hydroxyl radical (OHrad) and studied its implications in the immuno-pathology of rheumatoid arthritis (RA). Using various biophysical and biochemical techniques, changes in aromatic microenvironment of the IgG and the protein aggregation became evident after treatment with OHrad . The SDS-PAGE study confirmed the protein aggregation while far ultraviolet circular dichroism spectroscopy (Far-UV CD) and fourier transform infrared spectroscopy (FTIR) inferred towards the alterations in secondary structure of IgG under OHrad stress. Dynamic light scattering showed that the modification increased the hydrodynamic radius and polydispersity of IgG. The free arginine and lysine content reduced upon modification. OHrad induced aggregation was confirmed by enhanced thioflavin-T (ThT) fluorescence and red shift in the congo red (CR) absorbance. The study on experimental animals reiterates the earlier findings of enhanced immunogenicity of OHrad treated IgG (OHrad -IgG) compared to that of native IgG. OHrad -IgG strongly interacted with the antibodies derived from the serum of 80 rheumatoid arthritis (RA) patients. The overwhelming and strong tendency of OHrad -IgG to bind the antibodies derived from the serum of RA patients points towards the modification of IgG under patho-physiological conditions in RA that generate neo-epitopes and eventually cause the generation of auto antibodies that circulate in the patient sera. Further studies on this aspect may possibly lead to the development of a biomarker for RA.

Human T lymphotropic virus type II infection and humoral responses to pneumococcal polysaccharide and tetanus toxoid vaccines.

PubMed

Jarvis, Gary A; Janoff, Edward N; Cheng, Hui; Devita, Deborah; Fasching, Claudine; McCulloch, Charles E; Murphy, Edward L

2005-04-15

Infection with human T lymphotropic virus type II (HTLV-II) has been linked to an increased incidence of bacterial pneumonia. To determine whether HTLV-II infection is associated with impaired humoral immune responses, we immunized a cohort of HTLV-II-infected subjects and matched uninfected control subjects with 23-valent pneumococcal polysaccharide and tetanus toxoid vaccines. The pneumococcal polysaccharide vaccine elicited comparable and significant increases in concentrations of IgG against all 5 serotypes tested at 1 and 6 months after immunization in both groups. The avidity and opsonophagocytic functions of the anticapsular IgG were similar. The concentrations of tetanus toxoid-specific IgG also increased comparably and significantly over time in both groups. Thus, HTLV-II-infected persons develop robust humoral responses to potentially protective polysaccharide and protein vaccines.

Successful ovulation induction, conception, and normal delivery after chronic therapy with etanercept: a recombinant fusion anti-cytokine treatment for rheumatoid arthritis.

PubMed

Sills, E S; Perloe, M; Tucker, M J; Kaplan, C R; Palermo, G D

2001-11-01

Etanercept (Enbrel; Wyeth-Ayerst/Immunex Inc, Seattle, WA, USA) is a subcutaneously administered novel fusion protein consisting of the extracellular ligand-binding domain of the 75 kD receptor for tumor necrosis factor-alpha (anti-TNFalpha) and the Fc portion of human IgG1. The agent is synthesized by plasmid transfection of a Chinese hamster ovary cell line, utilizing recombinant DNA technology. Etanercept was approved by the US FDA for treatment of multi-drug resistant rheumatoid arthritis in 1998, but no human data exist regarding the impact of anti-TNFalpha therapy on human reproductive function or its use before ovulation induction. As TNFalpha potentiates collagenolysis via matrix metalloproteinase gene expression (thereby facilitating ovulation), there exists a theoretical risk that TNFalpha-inhibition could exert an undesirable effect on ovulation and pregnancy. In this report, we describe the first case of ovulation induction, intrauterine insemination, normal pregnancy and singleton delivery of a healthy infant following chronic ( > 1 year) pre-ovulatory TNFalpha-inhibitor therapy for rheumatoid arthritis. Reproductive endocrinologists and obstetrician-gynecologists should be familiar with etanercept therapy in the context of severe rheumatic disease, and offer appropriate reassurance regarding its safe use for infertility patients planning ovulation induction.

[Antiviral activity of IgG subclasses of immunoglobulin preparations for intravenous use].

PubMed

Litwińska, B; Bucholc, B; Biesiadecka, A; Kańtoch, M

1993-01-01

Preparations of human immunoglobulins for intravenous use (IVIG) should contain proper percentage of IgG subclasses, responding to physiological preparations with preserved activity of antibodies. The study was aimed at establishment of activity against measles, CMV and HSV viruses in individual subclasses of Bioglobulin (Biomed, Warszawa) and a comparison with preparation Polygam (Baxter, USA). Indirect immunofluorescence test was used. The results revealed presence of antiviral activity mostly in subclass IgG1 and also in IgG3, which is in keeping with results obtained by other authors. We have found an anti-HSV activity in a subclass IgG2 and IgG4 in IVIG preparations which was not yet described in the literature; it is confirmed, however, in investigations with application of sera of HSV-positive persons. These discrepancies may be caused by different methods of detection. Viral antigens in ELISA and IF tests may differ among themselves by content of individual epitopes. Basing on obtained results it can be stated that Polish preparation Bioglobulin (in which for the first time antiviral activity was determined in subclasses) is comparable with Polygam.

Isotype Diversification of IgG Antibodies to HIV Gag Proteins as a Therapeutic Vaccination Strategy for HIV Infection

PubMed Central

French, Martyn A.; Abudulai, Laila N.; Fernandez, Sonia

2013-01-01

The development of vaccines to treat and prevent human immunodeficiency virus (HIV) infection has been hampered by an incomplete understanding of “protective” immune responses against HIV. Natural control of HIV-1 infection is associated with T-cell responses against HIV-1 Gag proteins, particularly CD8+ T-cell responses restricted by “protective” HLA-B alleles, but other immune responses also contribute to immune control. These immune responses appear to include IgG antibodies to HIV-1 Gag proteins, interferon-α-dependant natural killer (NK) cell responses and plasmacytoid dendritic cell (pDC) responses. Here, it is proposed that isotype diversification of IgG antibodies against HIV-1 Gag proteins, to include IgG2, as well as IgG3 and IgG1 antibodies, will broaden the function of the antibody response and facilitate accessory cell responses against HIV-1 by NK cells and pDCs. We suggest that this should be investigated as a vaccination strategy for HIV-1 infection. PMID:26344116

Activation of effector functions by immune complexes of mouse IgG2a with isotype-specific autoantibodies.

PubMed Central

Rajnavölgyi, E; Fazekas, G; Lund, J; Daeron, M; Teillaud, J L; Jefferis, R; Fridman, W H; Gergely, J

1995-01-01

Analysis of five monoclonal autoantibodies, rheumatoid factors produced by hybridomas generated from spleen cells of BALB/c mice repeatedly infected with A/PR/8/34 human influenza A virus, revealed that they recognized distinct but spatially related epitopes. The differing isoallotypic specificity of the IgM and IgA monoclonal antibodies correlated with the presence of Ile258 and Ala305, respectively. Although these data suggest that the epitopes recognized are within the CH2 domain, all antibodies failed to inhibit IgG antigen reactivity with Staphylococcus aureus protein A (SpA), C1q, mouse C3, human Fc gamma RI or mouse Fc gamma RII, activities known to be predominantly determined by CH2 domain structures. Reactivity of the IgA antibody, Z34, with IgG2b allowed further specificity studies using a panel of 26 mutant IgG2b proteins, each having single amino acid replacements over the surface of the CH2 domain. The only substitution that affected Z34 reactivity was Asn/Ala297, which destroyed the glycosylation sequon, resulting in secretion of an aglycosylated IgG molecule. The epitope recognized by Z34 therefore seems to be located outside of the Fc gamma R and C1q binding sites, but to be dependent on the presence of carbohydrate for expression. In contrast to the binding studies, complement activation by aggregated IgG2a, through classical or alternative pathways, was inhibited by the presence of autoantibodies. The functional significance of isotype-specific autoantibody in immune regulation is discussed. PMID:7540592

From hybridomas to a robust microalgal-based production platform: molecular design of a diatom secreting monoclonal antibodies directed against the Marburg virus nucleoprotein.

PubMed

Hempel, Franziska; Maurer, Michael; Brockmann, Björn; Mayer, Christian; Biedenkopf, Nadine; Kelterbaum, Anne; Becker, Stephan; Maier, Uwe G

2017-07-27

The ideal protein expression system should provide recombinant proteins in high quality and quantity involving low production costs only. However, especially for complex therapeutic proteins like monoclonal antibodies many challenges remain to meet this goal and up to now production of monoclonal antibodies is very costly and delicate. Particularly, emerging disease outbreaks like Ebola virus in Western Africa in 2014-2016 make it necessary to reevaluate existing production platforms and develop robust and cheap alternatives that are easy to handle. In this study, we engineered the microalga Phaeodactylum tricornutum to produce monoclonal IgG antibodies against the nucleoprotein of Marburg virus, a close relative of Ebola virus causing severe hemorrhagic fever with high fatality rates in humans. Sequences for both chains of a mouse IgG antibody were retrieved from a murine hybridoma cell line and implemented in the microalgal system. Fully assembled antibodies were shown to be secreted by the alga and antibodies were proven to be functional in western blot, ELISA as well as IFA studies just like the original hybridoma produced IgG. Furthermore, synthetic variants with constant regions of a rabbit IgG and human IgG with optimized codon usage were produced and characterized. This study highlights the potential of microalgae as robust and low cost expression platform for monoclonal antibodies secreting IgG antibodies directly into the culture medium. Microalgae possess rapid growth rates, need basically only water, air and sunlight for cultivation and are very easy to handle.

Neuron-derived IgG protects dopaminergic neurons from insult by 6-OHDA and activates microglia through the FcγR I and TLR4 pathways.

PubMed

Zhang, Jie; Niu, Na; Wang, Mingyu; McNutt, Michael A; Zhang, Donghong; Zhang, Baogang; Lu, Shijun; Liu, Yuqing; Liu, Zhihui

2013-08-01

Oxidative and immune attacks from the environment or microglia have been implicated in the loss of dopaminergic neurons of Parkinson's disease. The role of IgG which is an important immunologic molecule in the process of Parkinson's disease has been unclear. Evidence suggests that IgG can be produced by neurons in addition to its traditionally recognized source B lymphocytes, but its function in neurons is poorly understood. In this study, extensive expression of neuron-derived IgG was demonstrated in dopaminergic neurons of human and rat mesencephalon. With an in vitro Parkinson's disease model, we found that neuron-derived IgG can improve the survival and reduce apoptosis of dopaminergic neurons induced by 6-hydroxydopamine toxicity, and also depress the release of NO from microglia triggered by 6-hydroxydopamine. Expression of TNF-α and IL-10 in microglia was elevated to protective levels by neuron-derived IgG at a physiologic level via the FcγR I and TLR4 pathways and microglial activation could be attenuated by IgG blocking. All these data suggested that neuron-derived IgG may exert a self-protective function by activating microglia properly, and IgG may be involved in maintaining immunity homeostasis in the central nervous system and serve as an active factor under pathological conditions such as Parkinson's disease. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Allergen-specific IgG antibodies purified from mite-allergic patients sera block the IgE recognition of Dermatophagoides pteronyssinus antigens: an in vitro study.

PubMed

Siman, Isabella Lima; de Aquino, Lais Martins; Ynoue, Leandro Hideki; Miranda, Juliana Silva; Pajuaba, Ana Claudia Arantes Marquez; Cunha-Júnior, Jair Pereira; Silva, Deise Aparecida Oliveira; Taketomi, Ernesto Akio

2013-01-01

One of the purposes of specific immunotherapy (SIT) is to modulate humoral immune response against allergens with significant increases in allergen-specific IgG levels, commonly associated with blocking activity. The present study investigated in vitro blocking activity of allergen-specific IgG antibodies on IgE reactivity to Dermatophagoides pteronyssinus (Dpt) in sera from atopic patients. Dpt-specific IgG antibodies were purified by ammonium sulfate precipitation followed by protein-G affinity chromatography. Purity was checked by SDS-PAGE and immunoreactivity by slot-blot and immunoblot assays. The blocking activity was evaluated by inhibition ELISA. The electrophoretic profile of the ammonium sulfate precipitated fraction showed strongly stained bands in ligand fraction after chromatography, compatible with molecular weight of human whole IgG molecule. The purity degree was confirmed by detecting strong immunoreactivity to IgG, negligible to IgA, and no reactivity to IgE and IgM. Dpt-specific IgG fraction was capable of significantly reducing levels of IgE anti-Dpt, resulting in 35%-51% inhibition of IgE reactivity to Dpt in atopic patients sera. This study showed that allergen-specific IgG antibodies purified from mite-allergic patients sera block the IgE recognition of Dermatophagoides pteronyssinus antigens. This approach reinforces that intermittent measurement of serum allergen-specific IgG antibodies will be an important objective laboratorial parameter that will help specialists to follow their patients under SIT.

Is There a Relationship between Zinc and the Peculiar Comorbidities of Down Syndrome?

ERIC Educational Resources Information Center

Romano, Corrado; Pettinato, Rosa; Ragusa, Letizia; Barone, Concetta; Alberti, Antonino; Failla, Pinella

2002-01-01

A comparison was made between a range of clinical and biochemical variables and zinc levels in 120 individuals with Down syndrome. No significant differences were found between the normal-zinc and low-zinc groups, except for IgG4 which was, unexpectedly, significantly decreased in the group with normal zinc levels. (Contains references.)…

Strategies for leukemic biomarker detection using long-range surface plasmon-polaritons

NASA Astrophysics Data System (ADS)

Krupin, O.; Wang, C.; Berini, P.

2014-09-01

The suitability and use of long-range surface plasmon-polaritons for leukemic biomarker detection is discussed. A novel optical biosensor comprised of gold straight waveguides embedded in CYTOP with an etched microfluidic channel was tested for detecting leukemia in patient serum. Gold surface functionalization involved the interaction of protein G (PG) with antibodies by first adsorbing PG on bare gold and then antibodies (Immunoglobulin G, IgG). Differentiation between healthy and leukemia patients was based on the difference in ratios of Ig kappa (Igκ) and Ig lambda (Igλ) light chains in both serums. The ratio for a normal patient is ~1.4 - 2, whereas for a leukemia patient this ratio is altered. As a receptor (primary antibodies), goat anti-human anti-IgGκ and anti-IgGλ were used to functionalize the surface. Diluted normal and leukemia patient serums were tested over the aforementioned surfaces. The ratios of mass surface densities of IgGκ:IgGλ for normal serum (NS) and patient serum (PS) were found to be 1.55 and 1.92 respectively.

Basigin/EMMPRIN/CD147 mediates neuron-glia interactions in the optic lamina of Drosophila.

PubMed

Curtin, Kathryn D; Wyman, Robert J; Meinertzhagen, Ian A

2007-11-15

Basigin, an IgG family glycoprotein found on the surface of human metastatic tumors, stimulates fibroblasts to secrete matrix metalloproteases (MMPs) that remodel the extracellular matrix, and is thus also known as Extracellular Matrix MetalloPRotease Inducer (EMMPRIN). Using Drosophila we previously identified novel roles for basigin. Specifically, photoreceptors of flies with basigin eyes show misplaced nuclei, rough ER and mitochondria, and swollen axon terminals, suggesting cytoskeletal disruptions. Here we demonstrate that basigin is required for normal neuron-glia interactions in the Drosophila visual system. Flies with basigin mutant photoreceptors have misplaced epithelial glial cells within the first optic neuropile, or lamina. In addition, epithelial glia insert finger-like projections--capitate projections (CPs)--sites of vesicle endocytosis and possibly neurotransmitter recycling. When basigin is missing from photoreceptors terminals, CP formation between glia and photoreceptor terminals is disrupted. Visual system function is also altered in flies with basigin mutant eyes. While photoreceptors depolarize normally to light, synaptic transmission is greatly diminished, consistent with a defect in neurotransmitter release. Basigin expression in photoreceptor neurons is required for normal structure and placement of glia cells.

Evaluation of a magnetic microsphere antibody detection assay for the investigation of exposure to Cryptosporidium parvum and Cryptosporidium hominis

EPA Science Inventory

Anti-Cryptosporidium IgA and IgG are useful markers of exposure to Cryptosporidium in human populations, but detection in saliva may be difficult. To evaluate a magnetic microsphere assay for detection of anti-Cryptosporidium IgA and IgG in saliva, recombinant sporozoite gp15 (1...

Development of a polyclonal anti-dugong immunoglobulin G (IgG) antibody with evaluation of total plasma IgG in a living dugong (Dugong dugon) population.

PubMed

Wong, Arthur; Lanyon, Janet M; McKee, Sara J; Linedale, Richard; Woolford, Lucy; Long, Trevor; Leggatt, Graham R

2018-06-01

Species-specific antibodies (Ab) for the measurement of immunoglobulins (Ig) are valuable tools for determining the humoral immune status of threatened and endangered wildlife species such as dugongs. However, no studies have reported antibody reagents against dugong immunoglobulin. The object of this study was to develop an Ab with specificity for dugong IgG and apply this tool to survey total IgG levels in plasma samples from a live wild population of dugongs in southern Queensland, Australia. Dugong IgG was isolated from plasma by protein A/G column chromatography and a polyclonal antiserum was successfully raised against the dugong IgG through immunization of mice. The anti-dugong antiserum was reactive with dugong serum but not immunoglobulin from other species such as rats and humans. When tested against a panel of dugong plasma samples, relative IgG levels from dugongs (n = 116) showed biologically relevant relationships with pregnancy status and a principal component of Body Mass Index (BMI)/globulin/fecal glucocorticosteroid (chronic stress) levels combined, which together accounted for 9.2% of the variation in total Ig levels. Together these data suggest that dugongs show variation in total IgG and that this correlates with some physiological parameters of dugong health. Copyright © 2018 Elsevier B.V. All rights reserved.

Comparative analysis of the diagnostic performance of crude sheep hydatid cyst fluid, purified antigen B and its subunit (12 Kda), assessed by ELISA, in the diagnosis of human cystic echinococcosis.

PubMed

Tawfeek, Gihan M; Elwakil, Hala S; El-Hoseiny, Laila; Thabet, Hala S; Sarhan, Rania M; Awad, Nabil S; Anwar, Wagida A

2011-02-01

The diagnosis of patients with cystic echinococcosis (CE) by means of serology has a limited support in clinical practice due to cross-reactivity with other helminthes leading to overestimation of the parasite's true prevalence. A wealth of reports on the diagnostic performance of antigen B (AgB) has been produced. This study was designed to comparatively assess the diagnostic efficacy of crude sheep hydatid cyst fluid (HCF), AgB and its subunit (12 KDa) to detect IgG or IgG4 antibodies in CE patients' sera using enzyme-linked immunosorbent assay (ELISA).The best diagnostic performance was obtained with anti-HCF IgG ELISA which gave 92.4% sensitivity and 92.6% specificity. Despite the low sensitivity of anti AgB IgG ELISA (84%), it gave the best specificity (94.4%) with less cross-reaction with sera of subjects infected with other parasites. In conclusion, it is recommended to use anti-HCF IgG ELISA for initial screening in large seroprevalence studies. Further analysis of positive serum samples with anti AgB IgG ELISA would allow the confirmation of true positives. Specific IgG4 ELISA may represent a complementary assay, useful as secondary confirmatory tests for patients with suspected CE and negative for total IgG ELISA.

Igg Subclasses Targeting the Flagella of Salmonella enterica Serovar Typhimurium Can Mediate Phagocytosis and Bacterial Killing

PubMed Central

Goh, Yun Shan; Armour, Kathryn L; Clark, Michael R; Grant, Andrew J; Mastroeni, Pietro

2016-01-01

Invasive non-typhoidal Salmonella are a common cause of invasive disease in immuno-compromised individuals and in children. Multi-drug resistance poses challenges to disease control, with a critical need for effective vaccines. Flagellin is an attractive vaccine candidate due to surface exposure and high epitope copy number, but its potential as a target for opsonophacytic antibodies is unclear. We examined the effect of targeting flagella with different classes of IgG on the interaction between Salmonella Typhimurium and a human phagocyte-like cell line, THP-1. We tagged the FliC flagellar protein with a foreign CD52 mimotope (TSSPSAD) and bacteria were opsonized with a panel of humanised CD52 antibodies with the same antigen-binding V-region, but different constant regions. We found that IgG binding to flagella increases bacterial phagocytosis and reduces viable intracellular bacterial numbers. Opsonisation with IgG3, followed by IgG1, IgG4, and IgG2, resulted in the highest level of bacterial uptake and in the highest reduction in the intracellular load of viable bacteria. Taken together, our data provide proof-of-principle evidence that targeting flagella with antibodies can increase the antibacterial function of host cells, with IgG3 being the most potent subclass. These data will assist the rational design of urgently needed, optimised vaccines against iNTS disease. PMID:27366588

Receptors for aggregated IgG on mouse lymphocytes: their presence on thymocytes, thymus-derived, and bone marrow-derived lymphocytes.

PubMed

Anderson, C L; Grey, H M

1974-05-01

An autoradiographic binding assay employing (125)I-labeled heat-aggregated mouse IgG2b myeloma protein (MOPC 141) was used to demonstrate receptors for IgG on 20-45% of Balb/c thymocytes and on 70-80% of splenocytes. Binding could also be shown with heat or BDB aggregates of another IgG2b (MOPC 195), with IgG1 and with human gamma-globulin, but not with aggregated chicken gamma-globulin, IgA, BSA, nor with aggregated Fab fragments of IgG2b. Optimum binding was obtained at 37 degrees C. Detection of binding was dependent upon aggregate size with complexes of more than 100 IgG molecules being optimal, aggregates of 6-25 detecting splenocytes but not thymocytes, and aggregates of less than 6 binding to a negligible extent. Comparison of grain counts on various cell types showed mastocytoma cells (P815) and macrophages averaging 40-50 grains/cell/day, allogeneically activated thymocytes 20-30, splenocytes 2-3, L5178 lymphoma cells 1, and positive thymocytes 0.6 grains/cell/day. Double labeling experiments for surface Ig, theta-antigen, and agg IgG receptor on mouse spleen cells indicated that a relatively high density of receptor was present on about 80% of B cells, 30% of T cells, and 60% of SIg(-), theta(-), null cells.

The relationship of the p–k titre to the serum ige level in patients with leprosy

PubMed Central

Hamburger, R. N.; Fernandez-Cruz, E.; Arnaiz, A.; Perez, B.; Bootello, A.

1974-01-01

Fifty patients with leprosy were found to have P–K titres inversely related to their serum IgE levels. Patients with leprosy react in a manner similar to normal individuals and to patients with other diseases. Serum IgG, IgM, IgA and complement were measured in twenty-five of the leprosy patients in addition to the serum IgE and only the IgG significantly positively correlated with the serum IgE. All of these leprosy patients were shown to react to exogenous histamine and they released endogenous histamine when chemically stimulated. Two patients had absent flare responses with normal weals, the remaining forty-eight had complete weal and flare responses. Higher serum IgE levels were noted in those patients with recent institution of chemotherapy. PMID:4143279

Ocular myasthenia gravis induced by human acetylcholine receptor ϵ subunit immunization in HLA DR3 transgenic mice.

PubMed

Wu, Xiaorong; Tuzun, Erdem; Saini, Shamsher S; Wang, Jun; Li, Jing; Aguilera-Aguirre, Leopoldo; Huda, Ruksana; Christadoss, Premkumar

2015-12-01

Extraocular muscles (EOM) are preferentially involved in myasthenia gravis (MG) and acetylcholine receptor (AChR) antibody positive MG patients may occasionally present with isolated ocular symptoms. Although experimental autoimmune myasthenia gravis (EAMG) induced by whole AChR immunization closely mimics clinical and immunopathological aspects of MG, EOM are usually not affected. We have previously developed an EAMG model, which imitates EOM symptoms of MG by immunization of human leukocyte antigen (HLA) transgenic mice with α or γ-subunits of human AChR (H-AChR). To investigate the significance of the ϵ-subunit in ocular MG, we immunized HLA-DR3 and HLA-DQ8 transgenic mice with recombinant H-AChR ϵ-subunit expressed in Escherichia coli. HLA-DR3 transgenic mice showed significantly higher clinical ocular and generalized MG severity scores and lower grip strength values than HLA-DQ8 mice. H-AChR ϵ-subunit-immunized HLA-DR3 transgenic mice had higher serum anti-AChR antibody (IgG, IgG1, IgG2b, IgG2c and IgM) levels, neuromuscular junction IgG and complement deposit percentages than ϵ-subunit-immunized HLA-DQ8 transgenic mice. Control mice immunized with E. coli extract or complete Freund adjuvant (CFA) did not show clinical and immunopathological features of ocular and generalized EAMG. Lymph node cells of ϵ-subunit-immunized HLA-DR3 mice showed significantly higher proliferative responses than those of ϵ-subunit-immunized HLA-DQ8 mice, crude E. coli extract-immunized and CFA-immunized transgenic mice. Our results indicate that the human AChR ϵ-subunit is capable of inducing myasthenic muscle weakness. Diversity of the autoimmune responses displayed by mice expressing different HLA class II molecules suggests that the interplay between HLA class II alleles and AChR subunits might have a profound impact on the clinical course of MG. Copyright © 2015 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

Functional capacities of human IgM memory B cells in early inflammatory responses and secondary germinal center reactions.

PubMed

Seifert, Marc; Przekopowitz, Martina; Taudien, Sarah; Lollies, Anna; Ronge, Viola; Drees, Britta; Lindemann, Monika; Hillen, Uwe; Engler, Harald; Singer, Bernhard B; Küppers, Ralf

2015-02-10

The generation and functions of human peripheral blood (PB) IgM(+)IgD(+)CD27(+) B lymphocytes with somatically mutated IgV genes are controversially discussed. We determined their differential gene expression to naive B cells and to IgM-only and IgG(+) memory B cells. This analysis revealed a high similarity of IgM(+)(IgD(+))CD27(+) and IgG(+) memory B cells but also pointed at distinct functional capacities of both subsets. In vitro analyses revealed a tendency of activated IgM(+)IgD(+)CD27(+) B cells to migrate to B-cell follicles and undergo germinal center (GC) B-cell differentiation, whereas activated IgG(+) memory B cells preferentially showed a plasma cell (PC) fate. This observation was supported by reverse regulation of B-cell lymphoma 6 and PR domain containing 1 and differential BTB and CNC homology 1, basic leucine zipper transcription factor 2 expression. Moreover, IgM(+)IgD(+)CD27(+) B lymphocytes preferentially responded to neutrophil-derived cytokines. Costimulation with catecholamines, carcinoembryonic antigen cell adhesion molecule 8 (CEACAM8), and IFN-γ caused differentiation of IgM(+)IgD(+)CD27(+) B cells into PCs, induced class switching to IgG2, and was reproducible in cocultures with neutrophils. In conclusion, this study substantiates memory B-cell characteristics of human IgM(+)IgD(+)CD27(+) B cells in that they share typical memory B-cell transcription patterns with IgG(+) post-GC B cells and show a faster and more vigorous restimulation potential, a hallmark of immune memory. Moreover, this work reveals a functional plasticity of human IgM memory B cells by showing their propensity to undergo secondary GC reactions upon reactivation, but also by their special role in early inflammation via interaction with immunomodulatory neutrophils.

HLA class I antibodies trigger increased adherence of monocytes to endothelial cells by eliciting an increase in endothelial P-selectin and, depending on subclass, by engaging FcγRs1

PubMed Central

Valenzuela, Nicole M; Mulder, Arend; Reed, Elaine F

2013-01-01

Antibody-mediated rejection of solid organ transplants is characterized by intragraft macrophages. It is incompletely understood how donor specific antibody binding to graft endothelium promotes monocyte adhesion, and what, if any, contribution is made by the Fc region of the antibody. We investigated the mechanisms underlying monocyte recruitment by HLA class I antibody-activated endothelium. We used a panel of murine monoclonal antibodies of different subclasses to crosslink HLA I on human aortic, venous and microvascular endothelial cells, and measured the binding of human monocytic cell lines and peripheral blood monocytes. Both anti-HLA I murine IgG1 and mIgG2a induced endothelial P-selectin, which was required for monocyte adhesion to endothelium irrespective of subclass. Mouse IgG2a but not mIgG1 could bind human FcγRs. Accordingly, HLA I mIgG2a but not mIgG1 treatment of endothelial cells significantly augmented recruitment, predominantly through FcγRI, and, to a lesser extent, FcγRIIa. Moreover, HLA I mIgG2a promoted firm adhesion of monocytes to ICAM-1 through Mac-1, which may explain the prominence of monocytes during antibody mediated rejection. We confirmed these observations using human HLA allele specific monoclonal antibodies and IgG purified from transplant patient sera. HLA I antibodies universally elicit endothelial exocytosis leading to monocyte adherence, implying that P-selectin is a putative therapeutic target to prevent macrophage infiltration during antibody-mediated rejection. Importantly, the subclass of donor specific antibody may influence its pathogenesis. These results imply that hIgG1 and hIgG3 should have a greater capacity to trigger monocyte infiltration into the graft than IgG2 or IgG4 due to enhancement by FcγR interactions. PMID:23690477

Usefulness of a single-assay chemiluminescence test (Tularaemia VIRCLIA IgG + IgM monotest) for the diagnosis of human tularemia. Comparison of five serological tests.

PubMed

Cubero, África; Durántez, Carlos; Almaraz, Ana; Fernández-Lago, Luis; Gutiérrez, María P; Castro, María J; Bratos, Miguel A; Simarro, María; March, Gabriel A; Orduña, Antonio

2018-04-01

The aim of this work was to ascertain the usefulness of a new commercially-available single-assay chemiluminescence test (CHT) for the diagnosis of human tularemia (Tularaemia VIRCLIA IgG + IgM monotest, Vircell, Santa Fe, Granada, Spain). A total of 773 sera from 773 patients including 364 initial sera from patients with diagnosed tularemia, patients with suspected tularemia not confirmed (100), healthy people (152), patients with serology positive to Brucella (97), patients diagnosed with other infectious diseases (30), and patients diagnosed with autoimmune diseases (30) were included. All sera were tested by CHT, "in-house" microagglutination test (MAT), immunochromatographic test (ICT) (Virapid Tularaemia, Vircell, Santa Fe Granada, Spain), and "in-house" ELISA IgG, and ELISA IgM. Of the total initial sera, 334 (sensitivity 91.8%) were positive in the CHT, 332 (sensitivity 91.2%) in the MAT, 330 (sensitivity 90.7%) in the ICT, and 328 (sensitivity 90.1%) in the ELISA IgG and ELISA IgM tests. The specificity of the CHT was 96.7%; of the MAT, 100%; of the ICT, 98.7%; and of the ELISA IgG and ELISA IgM, 97.4%. In the group of patients with serology positive to Brucella, at least 12.4% of sera were positive in tularemia tests (12.4% in ELISA IgM, 13.4% in MAT, 14.4% in ICT, and 15.5% in CHT and ELISA IgG). In conclusion, CHT presents a sensitivity and specificity in early diagnosis of human tularemia, similar to MAT, ICT, and ELISA IgG and ELISA IgM. Its single assay design allows lower costs, especially in areas of low endemicity or inter-epidemic periods.

Prevalence of toxoplasmosis and related risk factors among humans referred to main laboratories of Urmia city, North West of Iran, 2013.

PubMed

Sadaghian, Mohammad; Amani, Sasan; Jafari, Rasool

2016-06-01

Toxoplasmosis is mostly asymptomatic infection in immunocompetent individuals while it can cause a severe infection in human fetus during pregnancy and immunocompromised patients. This study aimed to determine the prevalence of anti-Toxoplasma IgM and IgG seropositivity and potential risk factors of the infection in humans referred to Urmia City main diagnostic laboratories, Urmia, Iran. Totally 195 blood samples were collected from the individuals referred to main diagnostic laboratories of Urmia City, 2013. Serum concentration of anti-Toxoplasma IgG and IgM were determined using ELISA method. Demographic variables of the participants were collected by interviewing, which are including sex, age, occupation, educational and residential status, eating undercooked meat, consumption of raw vegetable and the method of washing raw vegetables. None of all 200 serum sample were anti-Toxoplasma IgM positive, but different concentrations of anti-Toxoplasma IgG were observed in 88 (45.12 %) of samples. The significant higher rate of anti-Toxoplasma IgG seropositivity were observed in people with soil related jobs (P = 0.005, OR = 2.266; 95 % CI 1.260, 4.078) and history of eating raw vegetables at restaurant (P = 0.036, OR = 1.985; 95 % CI 0.991, 3.978). Also anti-Toxoplasma IgG concentration mean was significantly higher in people who were commonly eaten raw vegetable at restaurants (P < 0.001, t = 7.918). The prevalence of chronic toxoplasmosis is considerably high while the acute infection is very low in the studied area. Having soil related jobs and eating raw vegetables at restaurants increases the risk of acquiring the infection.

Development & validation of a quantitative anti-protective antigen IgG enzyme linked immunosorbent assay for serodiagnosis of cutaneous anthrax.

PubMed

Ghosh, N; Gunti, D; Lukka, H; Reddy, B R; Padmaja, Jyothi; Goel, A K

2015-08-01

Anthrax caused by Bacillus anthracis is primarily a disease of herbivorous animals, although several mammals are vulnerable to it. ELISA is the most widely accepted serodiagnostic assay for large scale surveillance of cutaneous anthrax. The aims of this study were to develop and evaluate a quantitative ELISA for determination of IgG antibodies against B. anthracis protective antigen (PA) in human cutaneous anthrax cases. Quantitative ELISA was developed using the recombinant PA for coating and standard reference serum AVR801 for quantification. A total of 116 human test and control serum samples were used in the study. The assay was evaluated for its precision, accuracy and linearity. The minimum detection limit and lower limit of quantification of the assay for anti-PA IgG were 3.2 and 4 µg/ml, respectively. The serum samples collected from the anthrax infected patients were found to have anti-PA IgG concentrations of 5.2 to 166.3 µg/ml. The intra-assay precision per cent CV within an assay and within an operator ranged from 0.99 to 7.4 per cent and 1.7 to 3.9 per cent, respectively. The accuracy of the assay was high with a per cent error of 6.5 - 24.1 per cent. The described assay was found to be linear between the range of 4 to 80 ng/ml (R [2] = 0.9982; slope = 0.9186; intercept = 0.1108). The results suggested that the developed assay could be a useful tool for quantification of anti-PA IgG response in human after anthrax infection or vaccination.

Seroprevalence of parvovirus B19 IgG and IgM antibodies among pregnant women in Oyo State, Nigeria.

PubMed

Abiodun, Iyanda; Opaleye, Oluyinka Oladele; Ojurongbe, Olusola; Fagbami, Ademola Hezekiah

2013-12-15

Human parvovirus B19 causes a wide range of complications in pregnant women including abortion, severe fetal anemia, non-immune hydrops fetalis, and even intrauterine fetal death. However, there is a dearth of information on the prevalence of the virus among pregnant women in southwestern Nigeria. Blood samples were collected from 231 pregnant women and screened for antibodies to human parvovirus B19 IgM and IgG using an enzyme immunosorbent assay kits. Of the 231 women, 31 were in their first trimester, 146 were in their second trimester, and 54 were in their third trimester. Forty-five (20%) were positive for parvovirus B19 IgG antibodies, 10 (4%) were positive for parvovirus B19 IgM antibodies, and 176 (76%) had no detectable parvovirus B19 antibodies. Twenty-eight (19%) of the 146 pregnant women in their second trimester were positive for parvovirus B19 IgG antibody while three (2%) of the 146 were positive for parvovirus B19 IgM antibody. It is evident that there is a high prevalence of human parvovirus B19 among pregnant women in south-western Nigeria. This suggests that there is an active transmission of the virus in the community; it is therefore necessary to conduct more studies on the virus in pregnant women in Nigeria to ascertain its effect on the fetus.

Variable Food-Specific IgG Antibody Levels in Healthy and Symptomatic Chinese Adults

PubMed Central

Wu, Liu-Xin; Li, Hong; Sun, Zhi-Jian; Li, Jing-Bo; Jiang, Hong-Xia; Chen, Zhi-Heng; Wang, Qi-Bin; Chen, Wei-Wei

2013-01-01

Background The presence of food-specific IgG antibodies in human serum may be useful for diagnosis of adverse food reactions. However, the clinical utility of tesing for such antibodies remains very controversial. The aim of this study was to evaluate the serum levels and population distribution of food-specific IgGs and their association with chronic symptoms in a large-scale Chinese population. Methodology/Principal Findings A total of 21305 adult participants from different regions of China had 14 type of food-specific serum IgG antibodies that were measured by enzyme-linked immunosorbent assay. Amongthese, 5,394 participants were randomly chosen to complete follow-up questionnaire surveys on their dietary characteristics and chronic symptoms. The concentrations of food-specific IgGs against 14 foods ranged from a median (interquartile range) of 7.3 (3.8, 12.6) U/mL of pork-specfic IgG to 42.3 (28.8, 60.2) U/mL of crab-specific IgG. The concentration of food-specific IgGs was closely related to gender; after adjustment for region and age, women had higher concentrations of food-specific IgGs against all of the 14 foods except chicken (regression coefficient (95% CI): 0.01 (−0.003, 0.023); P = 0.129) and corn (0.002 (−0.013, 0.016); P = 0.825). Similar results were also found in the relationship of geographic region to the food-specific IgG concentrations for the 14 foods. Chronic symptoms were negatively associated with the concentrations of a few food-specific IgGs, and were positively associated with the concentrations of other food-specific IgGs. Conclusions The levels of food-specific IgGs were variable both in healthy and in symptomatic Chinese adults. These findings raise awareness that demographic factors, the type of food and specific chronic symptoms should be considered before food elimination treatment based on IgG testing in patients with chronic symptoms is used in clinical practice. PMID:23301096

Phenotyping polyclonal kappa and lambda light chain molecular mass distributions in patient serum using mass spectrometry.

PubMed

Barnidge, David R; Dasari, Surendra; Ramirez-Alvarado, Marina; Fontan, Adrian; Willrich, Maria A V; Tschumper, Renee C; Jelinek, Diane F; Snyder, Melissa R; Dispenzieri, Angela; Katzmann, Jerry A; Murray, David L

2014-11-07

We previously described a microLC-ESI-Q-TOF MS method for identifying monoclonal immunoglobulins in serum and then tracking them over time using their accurate molecular mass. Here we demonstrate how the same methodology can be used to identify and characterize polyclonal immunoglobulins in serum. We establish that two molecular mass distributions observed by microLC-ESI-Q-TOF MS are from polyclonal kappa and lambda light chains using a combination of theoretical molecular masses from gene sequence data and the analysis of commercially available purified polyclonal IgG kappa and IgG lambda from normal human serum. A linear regression comparison of kappa/lambda ratios for 74 serum samples (25 hypergammaglobulinemia, 24 hypogammaglobulinemia, 25 normal) determined by microflowLC-ESI-Q-TOF MS and immunonephelometry had a slope of 1.37 and a correlation coefficient of 0.639. In addition to providing kappa/lambda ratios, the same microLC-ESI-Q-TOF MS analysis can determine the molecular mass for oligoclonal light chains observed above the polyclonal background in patient samples. In 2 patients with immune disorders and hypergammaglobulinemia, we observed a skewed polyclonal molecular mass distribution which translated into biased kappa/lambda ratios. Mass spectrometry provides a rapid and simple way to combine the polyclonal kappa/lambda light chain abundance ratios with the identification of dominant monoclonal as well as oligoclonal light chain immunoglobulins. We anticipate that this approach to evaluating immunoglobulin light chains will lead to improved understanding of immune deficiencies, autoimmune diseases, and antibody responses.

Global Structure of HIV-1 Neutralizing Antibody IgG1 b12 is Asymmetric

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ashish, F.; Solanki, A; Boone, C

2010-01-01

Human antibody IgG1 b12 is one of the four antibodies known to neutralize a broad range of human immunodeficiency virus-1. The crystal structure of this antibody displayed an asymmetric disposition of the Fab arms relative to its Fc portion. Comparison of structures solved for other IgG1 antibodies led to a notion that crystal packing forces entrapped a 'snap-shot' of different conformations accessible to this antibody. To elucidate global structure of this unique antibody, we acquired small-angle X-ray scattering data from its dilute solution. Data analysis indicated that b12 adopts a bilobal globular structure in solution with a radius of gyrationmore » and a maximum linear dimension of {approx}54 and {approx}180 {angstrom}, respectively. Extreme similarity between its solution and crystal structure concludes that non-flexible, asymmetric shape is an inherent property of this rare antibody.« less

Reduction of human anti-tetanus toxoid antibody in hu-PBL-SCID mice by immunodominant peptides of tetanus toxoid

PubMed Central

Jackson, D J; Elson, C J; Kumpel, B M

2004-01-01

Immunotherapy of murine autoimmune and allergic diseases by administration of peptides corresponding to the dominant T cell epitope is a reality. However, problems remain in applying this therapy to reduce antibody responses in humans. To overcome these difficulties, a preclinical system was developed to test the effect of immunodominant peptides from a common antigen, tetanus toxoid (TT), on the long-term human anti-TT response. Individuals whose T cells proliferated against dominant TT peptides were identified. Peripheral blood leucocytes (PBL) from these donors were injected intraperitoneally (i.p.) into mice with severe combined immunodeficiency (SCID) that had been depleted of murine natural killer (NK) cells (hu-PBL-SCID mice). Peptides or PBS were injected i.p. before a further injection of PBL and immunization with TT. The concentration of human IgG and anti-TT in murine plasma was followed for 10 weeks. The total IgG was similar in both groups. By contrast, there was a statistically significant reduction in IgG anti-TT from eight weeks onwards. It is considered that the hu-PBL-SCID model system may provide a means by which the efficacy of peptide immunotherapy for reduction of pathological antibodies in humans can be examined. PMID:15270840

Unproven techniques in allergy diagnosis.

PubMed

Wüthrich, B

2005-01-01

Mainstream allergy diagnosis and treatment is based on classical allergy testing which involves well-validated diagnostic methods and proven methods of treatment. By contrast, a number of unproven tests have been proposed for evaluating allergic patients including cytotoxic food testing, ALCAT test, bioresonance, electrodermal testing (electroacupuncture), reflexology, applied kinesiology a.o. There is little or no scientific rationale for these methods. Results are not reproducible when subject to rigorous testing and do not correlate with clinical evidence of allergy. Although some papers suggest a possible pathogenetic role of IgG, IgG4 antibody, no correlation was found between the outcome of DBPCFC and the levels of either food-specific IgG or IgG4, nor was any difference seen between patients and controls. The levels of these and other food-specific immunoglobulins of non-IgE isotype reflect the intake of food in the individual and may thus be a normal and harmless finding. The so-called "Food Allergy Profile" with simultaneous IgE and IgG determination against more than 100 foodstuffs is neither economical nor useful for diagnosis. DBPCFC must be the reference standard for food hypersensitivity and any new test must be validated by it. As a result, all these unproven techniques may lead to misleading advice or treatments, and their use is not advised.

Characterising the KMP-11 and HSP-70 recombinant antigens' humoral immune response profile in chagasic patients.

PubMed

Flechas, Ivonne D; Cuellar, Adriana; Cucunubá, Zulma M; Rosas, Fernando; Velasco, Víctor; Steindel, Mario; Thomas, María del Carmen; López, Manuel Carlos; González, John Mario; Puerta, Concepción Judith

2009-11-25

Antigen specificity and IgG subclass could be significant in the natural history of Chagas' disease. The relationship between the different stages of human Chagas' disease and the profiles of total IgG and its subclasses were thus analysed here; they were directed against a crude T. cruzi extract and three recombinant antigens: the T. cruzi kinetoplastid membrane protein-11 (rKMP-11), an internal fragment of the T. cruzi HSP-70 protein 192-433, and the entire Trypanosoma rangeli HSP-70 protein. Seventeen Brazilian acute chagasic patients, 50 Colombian chronic chagasic patients (21 indeterminate and 29 cardiopathic patients) and 30 healthy individuals were included. Total IgG and its subtypes directed against the above-mentioned recombinant antigens were determined by ELISA tests. The T. cruzi KMP-11 and T. rangeli HSP-70 recombinant proteins were able to distinguish both acute from chronic chagasic patients and infected people from healthy individuals. Specific antibodies to T. cruzi crude antigen in acute patients came from IgG3 and IgG4 subclasses whereas IgG1 and IgG3 were the prevalent isotypes in indeterminate and chronic chagasic patients. By contrast, the specific prominent antibodies in all disease stages against T. cruzi KMP-11 and T. rangeli HSP-70 recombinant antigens were the IgG1 subclass. T. cruzi KMP-11 and the T. rangeli HSP-70 recombinant proteins may be explored together in the immunodiagnosis of Chagas' disease. Polarising the IgG1 subclass of the IgG response to T. cruzi KMP-11 and T. rangeli HSP-70 recombinant proteins could have important biological effects, taking into account that this is a complement fixing antibody.

Antibodies elicited by the first non-viral prophylactic cancer vaccine show tumor-specificity and immunotherapeutic potential

PubMed Central

Lohmueller, Jason J.; Sato, Shuji; Popova, Lana; Chu, Isabel M.; Tucker, Meghan A.; Barberena, Roberto; Innocenti, Gregory M.; Cudic, Mare; Ham, James D.; Cheung, Wan Cheung; Polakiewicz, Roberto D.; Finn, Olivera J.

2016-01-01

MUC1 is a shared tumor antigen expressed on >80% of human cancers. We completed the first prophylactic cancer vaccine clinical trial based on a non-viral antigen, MUC1, in healthy individuals at-risk for colon cancer. This trial provided a unique source of potentially effective and safe immunotherapeutic drugs, fully-human antibodies affinity-matured in a healthy host to a tumor antigen. We purified, cloned, and characterized 13 IgGs specific for several tumor-associated MUC1 epitopes with a wide range of binding affinities. These antibodies bind hypoglycosylated MUC1 on human cancer cell lines and tumor tissues but show no reactivity against fully-glycosylated MUC1 on normal cells and tissues. We found that several antibodies activate complement-mediated cytotoxicity and that T cells carrying chimeric antigen receptors with the antibody variable regions kill MUC1+ target cells, express activation markers, and produce interferon gamma. Fully-human and tumor-specific, these antibodies are candidates for further testing and development as immunotherapeutic drugs. PMID:27545199

Gut Microbiota-Induced Immunoglobulin G Controls Systemic Infection by Symbiotic Bacteria and Pathogens

PubMed Central

Zeng, Melody Y.; Cisalpino, Daniel; Varadarajan, Saranyaraajan; Hellman, Judith; Warren, H. Shaw; Cascalho, Marilia; Inohara, Naohiro; Núñez, Gabriel

2016-01-01

The gut microbiota is compartmentalized in the intestinal lumen and induces local immune responses, but it remains unknown whether the gut microbiota can induce systemic response and contribute to systemic immunity. We report that selective gut symbiotic gram-negative bacteria were able to disseminate systemically to induce immunoglobulin G (IgG) response, which primarily targeted gram-negative bacterial antigens and conferred protection against systemic infections by E. coli and Salmonella by directly coating bacteria to promote killing by phagocytes. T cells and Toll-like receptor 4 on B cells were important in the generation of microbiota-specific IgG. We identified murein lipoprotein (MLP), a highly conserved gram-negative outer membrane protein, as a major antigen that induced systemic IgG homeostatically in both mice and humans. Administration of anti-MLP IgG conferred crucial protection against systemic Salmonella infection. Thus, our findings reveal an important function for the gut microbiota in combating systemic infection through the induction of protective IgG. PMID:26944199

Contactin 1 IgG4 associates to chronic inflammatory demyelinating polyneuropathy with sensory ataxia.

PubMed

Miura, Yumako; Devaux, Jérôme J; Fukami, Yuki; Manso, Constance; Belghazi, Maya; Wong, Anna Hiu Yi; Yuki, Nobuhiro

2015-06-01

A Spanish group recently reported that four patients with chronic inflammatory demyelinating polyneuropathy carrying IgG4 autoantibodies against contactin 1 showed aggressive symptom onset and poor response to intravenous immunoglobulin. We aimed to describe the clinical and serological features of Japanese chronic inflammatory demyelinating polyneuropathy patients displaying the anti-contactin 1 antibodies. Thirteen of 533 (2.4%) patients with chronic inflammatory demyelinating polyneuropathy had anti-contactin 1 IgG4 whereas neither patients from disease or normal control subjects did (P = 0.02). Three of 13 (23%) patients showed subacute symptom onset, but all of the patients presented with sensory ataxia. Six of 10 (60%) anti-contactin 1 antibody-positive patients had poor response to intravenous immunoglobulin, whereas 8 of 11 (73%) antibody-positive patients had good response to corticosteroids. Anti-contactin 1 IgG4 antibodies are a possible biomarker to guide treatment option. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Specific IgA and IgG antibodies in paired serum and breast milk samples in human strongyloidiasis.

PubMed

Mota-Ferreira, Daniela M L; Gonçalves-Pires, Maria do Rosário F; Júnior, Alvaro Ferreira; Sopelete, Mônica C; Abdallah, Vânia O S; Costa-Cruz, Julia M

2009-02-01

Strongyloidiasis, caused by the nematode Strongyloides stercoralis, is one of the major worldwide parasitic infections in humans. Breastfeeding may offer a potential protection against this infection. Feces, serum and milk samples were obtained from 90 lactating women from Clinical Hospital of Universidade Federal de Uberlândia, Brazil. The fecal samples were collected for parasitological diagnosis and the serum and milk samples were examined for specific S. stercoralis IgA and IgG antibodies using the indirect fluorescent antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA). Fecal examination showed that the rate of prevalence of S. stercoralis infection in the lactating women was 4.4%. IFAT manifested a 16.7% positivity rate for specific IgA antibody in serum and a 28.9% rate in milk samples; specific IgG was 41.1% in serum and 25.5% in milk samples. According to ELISA the positivity rate for specific IgA antibody was 21.1% in serum and 42.2% in milk samples; specific IgG was 40% in serum and 18.9% in milk samples. In serum samples, these immunological tests showed a concurrence of 91.1% and 94.4%, respectively, in detecting specific IgA and IgG antibodies. In milk samples, they showed a concurrence of 70% and 78.9%, respectively, in detecting specific IgA and IgG antibodies. There was a statistically significant difference between concordant and discordant results of immunological tests (P<0.0001). IFAT and ELISA highly concurred in their detection of specific S. stercoralis IgA and IgG antibodies in serum and in milk samples reconfirming prior studies that the serological method is a complement to the direct diagnosis of the parasite, and suggesting that immunological methods using milk samples can also be helpful. Furthermore, in endemic areas, infants may acquire antibodies to S. stercoralis from breast milk, possibly, contributing to the enhancement of specific mucosal immunity against this parasite.

Interleukin-7 (IL-7) enhances class switching to IgE and IgG4 in the presence of T cells via IL-9 and sCD23.

PubMed

Jeannin, P; Delneste, Y; Lecoanet-Henchoz, S; Gretener, D; Bonnefoy, J Y

1998-02-15

Interleukin-7 (IL-7) is a B-cell growth factor produced by both bone marrow stroma cells and follicular dendritic cells (FDCs) located in primary lymphoid follicles and germinal centers. In this study, we have evaluated the role of IL-7 on human Ig class switching. IL-7 was added to peripheral blood mononuclear cells (PBMCs) or tonsillar B cells in the absence or presence of IL-4 and/or anti-CD40 monoclonal antibody (MoAb). Alone, IL-7 did not affect Ig production by PBMCs or by anti-CD40 MoAb-stimulated B cells. Rather, IL-7 potentiated IL-4-induced IgE and IgG4 production by PBMCs. In parallel, IgG3 production was also enhanced but to a lesser extent, whereas the production of the other isotypes was unaltered. The activity of IL-2, IL-9, or IL-15, which share usage of the common gamma chain for signaling, was also assessed. IL-9, like IL-7, potentiated mainly IgE and IgG4 production by IL-4-stimulated PBMCs. IL-15, in contrast, was ineffective, whereas IL-2 enhanced the production of all isotypes. More precisely, IL-7 potentiation of IgE and IgG4 production required the presence of T cells and was accompanied by an increase of the expression of two soluble molecules favoring preferentially IgE and IgG4 synthesis: CD23 (sCD23) and IL-9. Moreover, neutralizing anti-CD23 and anti-IL-9 antibodies partly inhibited the increase of IgE synthesis induced by IL-7. Thus, IL-7 produced locally in the germinal centers by FDCs may interact with T cells and potentiate human IgE and IgG4 switching by favoring IL-9 and sCD23 production.

Proteolysis breaks tolerance toward intact α345(IV) collagen, eliciting novel anti-GBM autoantibodies specific for α345NC1 hexamers

PubMed Central

Olaru, Florina; Wang, Xu-Ping; Luo, Wentian; Ge, Linna; Miner, Jeffrey H; Kleinau, Sandra; Geiger, Xochiquetzal J.; Wasiluk, Andrew; Heidet, Laurence; Kitching, A. Richard; Borza, Dorin-Bogdan

2012-01-01

Goodpasture disease is an autoimmune kidney disease mediated by autoAbs against NC1 monomers of α3(IV) collagen that bind to the glomerular basement membrane (GBM), usually causing rapidly progressive glomerulonephritis. We identified a novel type of human IgG4-restricted anti-GBM autoAbs associated with mild non-progressive glomerulonephritis, which specifically targeted α345NC1 hexamers but not α3NC1 monomers. The mechanisms eliciting these anti-GBM autoAbs were investigated in mouse models recapitulating this phenotype. Wild type and FcγRIIB−/− mice immunized with autologous murine GBM NC1 hexamers produced mouse IgG1-restricted autoAbs specific for α345NC1 hexamers, which bound to the GBM in vivo but did not cause glomerulonephritis. In these mice, intact collagen IV from murine GBM was not immunogenic. However, in Col4a3−/− Alport mice, both intact collagen IV and NC1 hexamers from murine GBM elicited IgG antibodies specific for α3α4α5NC1 hexamers, which were not subclass restricted. As heterologous antigen in COL4A3-humanized mice, murine GBM NC1 hexamers elicited mouse IgG1, IgG2a and IgG2b autoAbs specific for α345NC1 hexamers and induced anti-GBM Ab glomerulonephritis. These findings indicate that tolerance toward autologous intact α3α4α5(IV) collagen is established in hosts expressing this antigen, even though autoreactive B cells specific for α345NC1 hexamers are not purged from their repertoire. Proteolysis selectively breaches this tolerance by generating autoimmunogenic α3α4α5NC1 hexamers. This provides a mechanism eliciting autoAbs specific for α345NC1 hexamers, which are restricted to non-inflammatory IgG subclasses and non-nephritogenic. In Alport syndrome, lack of tolerance toward α3α4α5(IV) collagen promotes production of alloantibodies to α345NC1 hexamers, including pro-inflammatory IgG subclasses which mediate post-transplant anti-GBM nephritis. PMID:23303673

Behavior of human immunoglobulin G adsorption onto immobilized Cu(II) affinity hollow-fiber membranes.

PubMed

Borsoi-Ribeiro, Mariana; Bresolin, Igor Tadeu Lazzarotto; Vijayalakshmi, Mookambeswaran; Bueno, Sônia Maria Alves

2013-10-01

Iminodiacetic acid (IDA) and tris(2-aminoethyl)amine (TREN) chelating ligands were immobilized on poly(ethylene vinyl alcohol) (PEVA) hollow-fiber membranes after activation with epichlorohydrin or butanediol diglycidyl ether (bisoxirane). The affinity membranes complexed with Cu(II) were evaluated for adsorption of human immunoglobulin G (IgG). The effects of matrix activation and buffer system on adsorption of IgG were studied. Isotherms of batch IgG adsorption onto finely cut membranes showed that neither of the chelates, IDA-Cu(II) or TREN-Cu(II), had a Langmuirean behavior with negative cooperativity for IgG binding. A comparison of equilibrium and dynamic maximum capacities showed that the dynamic capacity for a mini-cartridge in a cross-flow filtration mode (52.5 and 298.4 mg g(-1) dry weight for PEVA-TREN-Cu(II) and PEVA-IDA-Cu(II), respectively) was somewhat higher than the equilibrium capacity (9.2 and 73.3 mg g(-1) dry weight for PEVA-TREN-Cu(II) and PEVA-IDA-Cu(II), respectively). When mini-cartridges were used, the dynamic adsorption capacity of IDA-Cu(II) was the same for both mini-cartridge and agarose gel. Copyright © 2013 John Wiley & Sons, Ltd.

Human limbic encephalitis serum enhances hippocampal mossy fiber-CA3 pyramidal cell synaptic transmission.

PubMed

Lalic, Tatjana; Pettingill, Philippa; Vincent, Angela; Capogna, Marco

2011-01-01

Limbic encephalitis (LE) is a central nervous system (CNS) disease characterized by subacute onset of memory loss and epileptic seizures. A well-recognized form of LE is associated with voltage-gated potassium channel complex antibodies (VGKC-Abs) in the patients' sera. We aimed to test the hypothesis that purified immunoglobulin G (IgG) from a VGKC-Ab LE serum would excite hippocampal CA3 pyramidal cells by reducing VGKC function at mossy-fiber (MF)-CA3 pyramidal cell synapses. We compared the effects of LE and healthy control IgG by whole-cell patch-clamp and extracellular recordings from CA3 pyramidal cells of rat hippocampal acute slices. We found that the LE IgG induced epileptiform activity at a population level, since synaptic stimulation elicited multiple population spikes extracellularly recorded in the CA3 area. Moreover, the LE IgG increased the rate of tonic firing and strengthened the MF-evoked synaptic responses. The synaptic failure of evoked excitatory postsynaptic currents (EPSCs) was significantly lower in the presence of the LE IgG compared to the control IgG. This suggests that the LE IgG increased the release probability on MF-CA3 pyramidal cell synapses compared to the control IgG. Interestingly, α-dendrotoxin (120 nm), a selective Kv1.1, 1.2, and 1.6 subunit antagonist of VGKC, mimicked the LE IgG-mediated effects. This is the first functional demonstration that LE IgGs reduce VGKC function at CNS synapses and increase cell excitability. Wiley Periodicals, Inc. © 2010 International League Against Epilepsy.

Oriented immobilized anti-hIgG via F(c) fragment-imprinted PHEMA cryogel for IgG purification.

PubMed

Bereli, Nilay; Ertürk, Gizem; Tümer, M Aşkin; Say, Ridvan; Denizli, Adil

2013-05-01

Antibodies are used in many applications, especially as diagnostic and therapeutic agents. Among the various techniques used for the purification of antibodies, immunoaffinity chromatography is by far the most common. For this purpose, oriented immobilization of antibodies is an important step for the efficiency of purification step. In this study, F(c) fragment-imprinted poly(hydroxyethyl methacrylate) cryogel (MIP) was prepared for the oriented immobilization of anti-hIgG for IgG purification from human plasma. Non-imprinted poly(hydroxyethyl methacrylate) cryogel (NIP) was also prepared for random immobilization of anti-hIgG to compare the adsorption capacities of oriented (MIP/anti-hIgG) and random (NIP/anti-hIgG) cryogel columns. The amount of immobilized anti-hIgG was 19.8 mg/g for the NIP column and 23.7 mg/g for the MIP column. Although the amount of immobilized anti-hIgG was almost the same for the NIP and MIP columns, IgG adsorption capacity was found to be three times higher than the NIP/anti-hIgG column (29.7 mg/g) for the MIP/anti-hIgG column (86.9 mg/g). Higher IgG adsorption capacity was observed from human plasma (up to 106.4 mg/g) with the MIP/anti-hIgG cryogel column. Adsorbed IgG was eluted using 1.0 M NaCl with a purity of 96.7%. The results obtained here are very encouraging and showed the usability of MIP/anti-hIgG cryogel prepared via imprinting of Fc fragments as an alternative to conventional immunoaffinity techniques for IgG purification. Copyright © 2012 John Wiley & Sons, Ltd.

First attempt to validate the gSG6-P1 salivary peptide as an immuno-epidemiological tool for evaluating human exposure to Anopheles funestus bites.

PubMed

Poinsignon, Anne; Samb, Badara; Doucoure, Souleymane; Drame, Papa-Makhtar; Sarr, Jean Biram; Sow, Cheikh; Cornelie, Sylvie; Maiga, Sophie; Thiam, Cheikh; Rogerie, François; Guindo, Sohidou; Hermann, Emmanuel; Simondon, François; Dia, Ibrahima; Riveau, Gilles; Konate, Lassana; Remoue, Franck

2010-10-01

The development of a biomarker of exposure based on the evaluation of the human antibody response specific to Anopheles salivary proteins seems promising in improving malaria control. The IgG response specific to the gSG6-P1 peptide has already been validated as a biomarker of An. gambiae exposure. This study represents a first attempt to validate the gSG6-P1 peptide as an epidemiological tool evaluating exposure to An. funestus bites, the second main malaria vector in sub-Saharan Africa. A multi-disciplinary survey was performed in a Senegalese village where An. funestus represents the principal anopheline species. The IgG antibody level specific to gSG6-P1 was evaluated and compared in the same children before, at the peak and after the rainy season. Two-thirds of the children developed a specific IgG response to gSG6-P1 during the study period and--more interestingly--before the rainy season, when An. funestus was the only anopheline species reported. The specific IgG response increased during the An. funestus exposure season, and a positive association between the IgG level and the level of exposure to An. funestus bites was observed. The results suggest that the evaluation of the IgG response specific to gSG6-P1 in children could also represent a biomarker of exposure to An. funestus bites. The availability of such a biomarker evaluating the exposure to both main Plasmodium falciparum vectors in Africa could be particularly relevant as a direct criterion for the evaluation of the efficacy of vector control strategies. © 2010 Blackwell Publishing Ltd.

TOXOPLASMA AND VIRAL ANTIBODIES AMONG HIV PATIENTS AND INMATES IN CENTRAL JAVA, INDONESIA.

PubMed

Sari, Yulia; Haryati, Sri; Raharjo, Irvan; Prasetyo, Afiono Agung

2015-11-01

In Indonesia, Toxoplasma and its associations with blood-borne viruses have been poorly studied. In order to study the association between anti-Toxoplasma antibodies and blood-borne viral antibodies, blood samples from 497 participants (375 inmates from four prisons in Central Java, Indonesia and 122 HIV patients at a Voluntary Counseling and Testing Clinic in Surakarta, Indonesia) were tested for serological markers of Toxoplasma, human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV) and human T-lymphotropic virus types I and II (HTLV-1/2). Anti-Toxoplasma IgG and IgM positivity rates were 41.6% and 3.6%, respectively. One point two percent of participants was positive for both anti-Toxoplasma IgG and IgM antibodies. Sixteen point five percent, 11.3%, 2.6% and 2.8% of participants were positive for anti- Toxoplasma IgG combined with anti-HCV antibodies, anti-Toxoplasma IgG combined with anti-HIV antibodies, anti-Toxoplasma IgM combined with anti-HIV antibodes and anti-Toxoplasma IgG combined with both anti-HIV and anti-HCV antibodies, respectively. Anti-Toxoplasma IgM seropositivity was associated with anti-HIV (aOR = 4.3; 95% CI: 1.112-16.204, p = 0.034). Anti-Toxoplasma IgG antibodies were associated with anti-HCV (aOR = 2.8; 95% CI: 1.749-4.538, p < 0.001) and history of injection drug use (aOR = 3.1; 95% CI: 1.905-5.093, p < 0.001). In conclusion, we recommend patients with HIV, HCV infection and injection drug users should be screened for Toxoplasma infection in Indonesia.

Dissection of the Antibody Response against Herpes Simplex Virus Glycoproteins in Naturally Infected Humans

PubMed Central

Huang, Zhen-Yu; Whitbeck, J. Charles; Ponce de Leon, Manuel; Lou, Huan; Wald, Anna; Krummenacher, Claude; Eisenberg, Roselyn J.; Cohen, Gary H.

2014-01-01

ABSTRACT Relatively little is known about the extent of the polyclonal antibody (PAb) repertoire elicited by herpes simplex virus (HSV) glycoproteins during natural infection and how these antibodies affect virus neutralization. Here, we examined IgGs from 10 HSV-seropositive individuals originally classified as high or low virus shedders. All PAbs neutralized virus to various extents. We determined which HSV entry glycoproteins these PAbs were directed against: glycoproteins gB, gD, and gC were recognized by all sera, but fewer sera reacted against gH/gL. We previously characterized multiple mouse monoclonal antibodies (MAbs) and mapped those with high neutralizing activity to the crystal structures of gD, gB, and gH/gL. We used a biosensor competition assay to determine whether there were corresponding human antibodies to those epitopes. All 10 samples had neutralizing IgGs to gD epitopes, but there were variations in which epitopes were seen in individual samples. Surprisingly, only three samples contained neutralizing IgGs to gB epitopes. To further dissect the nature of these IgGs, we developed a method to select out gD- and gB-specific IgGs from four representative sera via affinity chromatography, allowing us to determine the contribution of antibodies against each glycoprotein to the overall neutralization capacity of the serum. In two cases, gD and gB accounted for all of the neutralizing activity against HSV-2, with a modest amount of HSV-1 neutralization directed against gC. In the other two samples, the dominant response was to gD. IMPORTANCE Antibodies targeting functional epitopes on HSV entry glycoproteins mediate HSV neutralization. Virus-neutralizing epitopes have been defined and characterized using murine monoclonal antibodies. However, it is largely unknown whether these same epitopes are targeted by the humoral response to HSV infection in humans. We have shown that during natural infection, virus-neutralizing antibodies are principally directed against gD, gB, and, to a lesser extent, gC. While several key HSV-neutralizing epitopes within gD and gB are commonly targeted by human serum IgG, others fail to induce consistent responses. These data are particularly relevant to the design of future HSV vaccines. PMID:25142599

Mannan adjuvants intranasally administered inactivated influenza virus in mice rendering low doses inductive of strong serum IgG and IgA in the lung.

PubMed

Proudfoot, Owen; Esparon, Sandra; Tang, Choon-Kit; Laurie, Karen; Barr, Ian; Pietersz, Geoffrey

2015-02-26

H1N1 influenza viruses mutate rapidly, rendering vaccines developed in any given year relatively ineffective in subsequent years. Thus it is necessary to generate new vaccines every year, but this is time-consuming and resource-intensive. Should a highly virulent influenza strain capable of human-to-human transmission emerge, these factors will severely limit the number of people that can be effectively immunised against that strain in time to prevent a pandemic. An adjuvant and mode of administration capable of rendering ordinarily unprotective vaccine doses protective would thus be highly advantageous. The carbohydrate mannan was conjugated to whole inactivated H1N1 influenza virus at a range of ratios, and mixed with it at a range of ratios, and various doses of the resulting preparations were administered to mice via the intranasal (IN) route. Serum immunity was assessed via antigen-specific IgG ELISA and the haemagglutination-inhibition (HI) assay, and mucosal immunity was assessed via IgA ELISA of bronchio-alveolar lavages. IN-administered inactivated H1N1 mixed with mannan induced higher serum IgG and respiratory-tract IgA than inactivated H1N1 conjugated to mannan, and HIN1 alone. Adjuvantation was mannan-dose-dependent, with 100 μg of mannan adjuvanting 1 μg of H1N1 more effectively than 10 or 50 μg of mannan. Serum samples from mice immunised with 1 μg H1N1 adjuvanted with 10 μg mannan did not inhibit agglutination of red blood cells (RBCs) at a dilution factor of 10 in the HI assay, but samples resulting from adjuvantation with 50 and 100 μg mannan inhibited agglutination at dilution factors of ≥ 40. Both serum IgG1 and IgG2a were induced by IN mannan-adjuvanted H1N1 vaccination, suggesting the induction of humoral and cellular immunity. Mixing 100 μg of mannan with 1 μg of inactivated H1N1 adjuvanted the vaccine in mice, such that IN immunisation induced higher serum IgG and respiratory tract IgA than immunisation with virus alone. The serum from mice thus immunised inhibited H1N1-mediated RBC agglutination strongly in vitro. If mannan similarly adjuvants low doses of influenza vaccine in humans, it could potentially be used for vaccine 'dose-sparing' in the event that a vaccine shortage arises from an epidemic involving a highly virulent human-to-human transmissable influenza strain.

Antiapolipoprotein A-1 IgG chronotropic effects require nongenomic action of aldosterone on L-type calcium channels.

PubMed

Rossier, Michel F; Pagano, Sabrina; Python, Magaly; Maturana, Andres D; James, Richard W; Mach, François; Roux-Lombard, Pascale; Vuilleumier, Nicolas

2012-03-01

Autoantibodies to apolipoprotein A-1 (antiapoA-1 IgG) have been shown to be associated with higher resting heart rate and morbidity in myocardial infarction patients and to behave as a chronotropic agent in the presence of aldosterone on isolated neonatal rat ventricular cardiomyocytes (NRVC). We aimed at identifying the pathways accounting for this aldosterone-dependent antiapoA-1 IgG-positive chronotropic effect on NRVC. The rate of regular spontaneous contractions was determined on NRVC in the presence of different steroid hormones and antagonists. AntiapoA-1 IgG chronotropic response was maximal within 20 min and observed only in aldosterone-pretreated cells but not in those exposed to other steroids. The positive antiapoA-1 IgG chronotropic effect was already significant after 5 min aldosterone preincubation, was dependent on 3-kinase and protein kinase A activities, was not inhibited by actinomycin D, and was fully abrogated by eplerenone (but not by spironolactone), demonstrating the dependence on a nongenomic action of aldosterone elicited through the mineralocorticoid receptor (MR). Under oxidative conditions (but not under normal redox state), corticosterone mimicked the permissive action of aldosterone on the antiapoA-1 IgG chronotropic response. Pharmacological and patch-clamp studies identified L-type calcium channels as crucial effectors of antiapoA-1 IgG chronotropic action, involving two converging pathways that increase the channel activity. The first one involves the rapid, nongenomic activation of the phosphatidylinositol 3-kinase enzyme by MR, and the second one requires a constitutive basal protein kinase A activity. In conclusion, our results indicate that, on NRVC, the aldosterone-dependent chronotropic effects of antiapoA-1 IgG involve the nongenomic activation of L-type calcium channels.

Synergistic actions of pemphigus vulgaris IgG, Fas-ligand and tumor necrosis factor-alpha during induction of basal cell shrinkage and acantholysis.

PubMed

Orlov, Maxim D; Chernyavsky, Alex I; Arredondo, Juan; Grando, Sergei A

2006-11-01

This study tested a recently proposed "Basal Cell Shrinkage" hypothesis of pemphigus acantholysis through a quantitative analysis of individual and cooperative effects of pemphigus vulgaris (PV) IgG, Fas-ligand (Fas-L) and tumor necrosis factor-alpha (TNFalpha) on keratinocyte (KC) volume (i.e. cell size) and adhesive properties. Exposure of KC monolayers and MatTek EpiDermFT tissues cultures to the physiologic concentrations of Fas-L, TNFalpha or IgGs from two PV patients resulted in various degrees of reversible changes, which were not observed in control cultures either exposed to normal IgG or left intact. Within 12-24 h of exposure, basal cells in experimental cultures lost their ability to form stress fibers, retracted cytoplasmic aprons and formed keratin aggregates, indicating that their cytoskeleton collapsed. The cell volume decreased significantly (p < 0.05) as the polygonal cell shape changed to a round one. The shrunk cells detached from their neighbors and the substrate, resulting in a reciprocal increase of both the areas of acantholysis and the number of detached KCs, respectively. Since in the skin of PV patients, KCs are targeted by autoantibodies concomitantly with being exposed to autocrine and paracrine pro-apoptotic and pro-inflammatory cytokines, we combined PV IgG with Fas-L and/or TNFalpha in the cell culture experiments. This amplified several fold an ability of PV IgG to cause basal cell shrinkage and detachment. The obtained results demonstrated for the first time that PV IgG works together with Fas-L and TNFalpha to induce acantholysis via basal cell shrinkage, which provides a novel mechanism explaining successful treatment of PV patients with TNFalpha inhibitors.

Seroconversion to filarial antigens in Australian defence force personnel in Timor-Leste.

PubMed

Frances, Stephen P; Baade, Lisa M; Kubofcik, Joseph; Nutman, Thomas B; Melrose, Wayne D; McCarthy, James S; Nissen, Michael D

2008-04-01

To investigate whether Australian soldiers were exposed to filarial parasites that cause lymphatic filariasis during a 6-month deployment to Timor-Leste, antifilarial antibody levels were measured in 907 soldiers using an enzyme linked immunosorbent assay (ELISA). Initial testing using Dirofilaria immitis antigen demonstrated that 49 of 907 (5.4%) soldiers developed antifilarial antibodies of the IgG1 subclass after deployment, whereas 1 of 944 (0.1%) seroconverted to the IgG4 subclass. When a sub sample of 88 D. immitis-reactive sera was subject to testing with an antifilarial antibody test using Brugia malayi antigen, 46 had elevated IgG antibodies, whereas 5 had elevated antibodies of the IgG4 subclass. A total of 24 soldiers seroconverted to B. malayi, as measured by parasite-specific IgG, whereas 1 seroconverted to IgG4. The relatively low number of seroconversions indicates a low but measurable risk of exposure to human filarial parasites among Australian soldiers deployed to Timor-Leste. However, to reduce the risk of exposure to these parasites, soldiers deploying to endemic areas should practice strict adherence to personal protective measures against mosquito bites.

Effects of immunization with the rNfa1 protein on experimental Naegleria fowleri-PAM mice.

PubMed

Lee, Y J; Kim, J H; Sohn, H J; Lee, J; Jung, S Y; Chwae, Y J; Kim, K; Park, S; Shin, H J

2011-07-01

Free-living Naegleria fowleri causes primary amoebic meningoencephalitis (PAM) in humans and animals. To examine the effect of immunization with Nfa1 protein on experimental murine PAM because of N. fowleri, BALB/c mice were intra-peritoneally or intra-nasally immunized with a recombinant Nfa1 protein. We analysed Nfa1-specific antibody and cytokine induction, and the mean survival time of infected mice. Mice immunized intra-peritoneally or intra-nasally with rNfa1 protein developed specific IgG, IgA and IgE antibodies; the IgG response was dominated by IgG1, followed by IgG2b, IgG2a and IgG3. High levels of the Th1 cytokine, IFN-γ, and the regulatory cytokine, IL-10, were also induced. The mean survival time of mice immunized intra-peritoneally with rNfa1 protein was prolonged compared with controls, (25.0 and 15.5 days, respectively). Similarly, the mean survival time of mice immunized intra-nasally with rNfa1 protein was 24.7 days, compared with 15.0 days for controls. © 2011 Blackwell Publishing Ltd.

Prevalence and risk factors of Rift Valley fever in humans and animals from Kabale district in Southwestern Uganda, 2016

PubMed Central

de St. Maurice, Annabelle; Purpura, Lawrence; Ervin, Elizabeth; Balinandi, Stephen; Tumusiime, Alex; Kyondo, Jackson; Mulei, Sophia; Tusiime, Patrick; Lutwama, Julius; Klena, John D.; Brown, Shelley; Knust, Barbara; Rollin, Pierre E.; Nichol, Stuart T.

2018-01-01

Background Rift Valley fever (RVF) is a zoonotic disease caused by Rift Valley fever virus (RVFV) found in Africa and the Middle East. Outbreaks can cause extensive morbidity and mortality in humans and livestock. Following the diagnosis of two acute human RVF cases in Kabale district, Uganda, we conducted a serosurvey to estimate RVFV seroprevalence in humans and livestock and to identify associated risk factors. Methods Humans and animals at abattoirs and villages in Kabale district were sampled. Persons were interviewed about RVFV exposure risk factors. Human blood was tested for anti-RVFV IgM and IgG, and animal blood for anti-RVFV IgG. Principal findings 655 human and 1051 animal blood samples were collected. Anti-RVFV IgG was detected in 78 (12%) human samples; 3 human samples (0.5%) had detectable IgM only, and 7 (1%) had both IgM and IgG. Of the 10 IgM-positive persons, 2 samples were positive for RVFV by PCR, confirming recent infection. Odds of RVFV seropositivity were greater in participants who were butchers (odds ratio [OR] 5.1; 95% confidence interval [95% CI]: 1.7–15.1) and those who reported handling raw meat (OR 3.4; 95% CI 1.2–9.8). No persons under age 20 were RVFV seropositive. The overall animal seropositivity was 13%, with 27% of cattle, 7% of goats, and 4% of sheep seropositive. In a multivariate logistic regression, cattle species (OR 9.1; 95% CI 4.1–20.5), adult age (OR 3.0; 95% CI 1.6–5.6), and female sex (OR 2.1; 95%CI 1.0–4.3) were significantly associated with animal seropositivity. Individual human seropositivity was significantly associated with animal seropositivity by subcounty after adjusting for sex, age, and occupation (p < 0.05). Conclusions Although no RVF cases had been detected in Uganda from 1968 to March 2016, our study suggests that RVFV has been circulating undetected in both humans and animals living in and around Kabale district. RVFV seropositivity in humans was associated with occupation, suggesting that the primary mode of RVFV transmission to humans in Kabale district could be through contact with animal blood or body fluids. PMID:29723189

Total serum IgE and parasite-specific IgG and IgA antibodies in human strongyloidiasis.

PubMed

Rossi, C L; Takahashi, E E; Partel, C D; Teodoro, L G; da Silva, L J

1993-01-01

Total serum IgE, and Strongyloides-specific IgG and IgA antibodies were studied in 27 patients with parasitologically proven strongyloidiasis. Clinical manifestations in this case series were investigated by a retrospective study of the patient's records. Total serum IgE levels were elevated (greater than 250 IU/ml) in 59% of the patients (mean concentration = 1364 IU/ml). Parasite-specific IgG and IgA antibodies were detected by ELISA in the serum of 23 (85.2%) and 21 (77.8%) patients, respectively. Elevated serum IgE and clinical manifestations were not useful indexes of the presence of strongyloidiasis. On the other hand, our results support the view that serologic tests, particularly ELISA for detecting Strongyloides-specific IgG antibodies, can be usefully exploited for diagnostic purposes in strongyloidiasis.

Isoelectric focusing-affinity immunoblot analysis of mouse monoclonal antibodies to the four human IgG subclasses

NASA Technical Reports Server (NTRS)

Hamilton, Robert G.; Roebber, Marianne; Rodkey, L. Scott; Reimer, Charles B.

1987-01-01

Isoelectric focusing (IEF)/affinity immunoblotting and enzyme-linked immunosorbent assay (ELISA) were used for parallel analysis of murine monoclonal antihuman IgG-subclass antisera (MoAbs). Coomassie Blue-stained protein bands in the pH region 5.5-8.0 were shown to be murine IgG by direct blotting onto nitrocellulose followed by detection with conjugated antimouse IgG. Use of IgG myeloma antigen-coated nitrocellulose in the IEF-affinity immunoblot allowed detection of the charge microheterogeneity of MoAbs. The MoAb group contained one to five major dense bands flanked by up to four minor fainter bands, all with pIs ranging from 6.1 to 7.8. Semiquantitative estimates of binding specificity in the IEF-affinity blot compared well with cross-reactivity data obtained from a quantitative ELISA.

The Clinical and Immunologic Features of Patients With Combined Anti-GBM Disease and Castleman Disease.

PubMed

Gu, Qiu-Hua; Jia, Xiao-Yu; Hu, Shui-Yi; Wang, Su-Xia; Zou, Wan-Zhong; Cui, Zhao; Zhao, Ming-Hui

2018-06-01

Patients with both anti-glomerular basement membrane (anti-GBM) disease and Castleman disease have been rarely reported. In this study, we report 3 patients with this combination. They had immunologic features similar to patients with classic anti-GBM disease. Sera from the 3 patients recognized the noncollagenous (NC) domain of the α3 chain of type IV collagen (α3(IV)NC1) and its 2 major epitopes, EA and EB. All 4 immunogloblin G (IgG) subclasses against α3(IV)NC1 were detectable, with predominance of IgG1. In one patient with lymph node biopsy specimens available, sporadic plasma cells producing α3(IV)NC1-IgG were found, suggesting a causal relationship between the 2 diseases. One patient, who achieved remission with antibody clearance and normalization of serum creatinine and interleukin 6 concentrations after plasma exchange and 3 cycles of chemotherapy, experienced recurrence of anti-GBM antibodies and an increase in interleukin 6 concentration after chemotherapy discontinuation because of adverse effects, but both returned to normal after another cycle of chemotherapy. This clinical course and the pathologic findings support the hypothesis that the Castleman disease-associated tumor cells are the source of the anti-GBM autoantibodies. Copyright © 2018 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Bronchial asthma is not associated with auto-antibodies to lipocortin-1.

PubMed

Wilkinson, J R; Podgorski, M R; Godolphin, J L; Goulding, N J; Lee, T H

1990-03-01

Corticosteroids may mediate some of their anti-inflammatory action by the induction of lipocortin-1, which inhibits phospholipase A2 activity. Raised levels of antibodies to lipocortin have been found in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) and it has been postulated that these may contribute to steroid resistance. A proportion of asthmatic patients fail to respond to treatment with corticosteroids and one possible mechanism is that these patients have raised levels of anti-lipocortin antibodies. We have therefore measured IgG and IgM antibodies to lipocortin by enzyme linked immunosorbent assay (ELISA) in eight corticosteroid-sensitive (CS) and 7 corticosteroid-resistant (CR) asthmatic subjects, and in eight normal controls. Comparison of asthmatic subjects with normal controls revealed no significant differences in either IgG or IgM antibodies to lipocortin. Comparison of CS asthmatic subjects with CR asthmatic subjects similarly revealed no significant differences in the concentration of either IgG or IgM antibodies to lipocortin. Levels of anti-lipocortin antibodies did not correlate with clinical response to treatment with 40 mg/day of prednisolone. Anti-lipocortin antibodies are unlikely to be involved in the inflammation seen in asthma, or in the relative insensitivity to corticosteroids seen in CR asthmatic subjects.

Process Research and Development of Antibodies as Countermeasures for C. botulinum

DTIC Science & Technology

2009-02-01

1. Diagram of plasmid pS25. Plasmid contains the light ( LC ) and heavy chains (HC) of S25 antibody against BoNT serotype A, along with dhfr as a...column, an MEP-hypercel column (100mm · 4.6mm di- ameter), or an EDTPA modified zirconia column (Zir- chrom ) (50mm · 4.6mm diameter). Prior to loading...Human IgG (2lg), (3) Human IgG (0.4lg), (4) CHO-S-SFM II media, (5) CHO-DG44 S25 supernatant, (6) rProtein A pooled peak fraction (ultrafiltered load), (7

Synthetic Human Monoclonal Antibodies toward Staphylococcal Enterotoxin B (SEB) Protective against Toxic Shock Syndrome*

PubMed Central

Karauzum, Hatice; Chen, Gang; Abaandou, Laura; Mahmoudieh, Mahta; Boroun, Atefeh R.; Shulenin, Sergey; Devi, V. Sathya; Stavale, Eric; Warfield, Kelly L.; Zeitlin, Larry; Roy, Chad J.; Sidhu, Sachdev S.; Aman, M. Javad

2012-01-01

Staphylococcal enterotoxin B (SEB) is a potent toxin that can cause toxic shock syndrome and act as a lethal and incapacitating agent when used as a bioweapon. There are currently no vaccines or immunotherapeutics available against this toxin. Using phage display technology, human antigen-binding fragments (Fabs) were selected against SEB, and proteins were produced in Escherichia coli cells and characterized for their binding affinity and their toxin neutralizing activity in vitro and in vivo. Highly protective Fabs were converted into full-length IgGs and produced in mammalian cells. Additionally, the production of anti-SEB antibodies was explored in the Nicotiana benthamiana plant expression system. Affinity maturation was performed to produce optimized lead anti-SEB antibody candidates with subnanomolar affinities. IgGs produced in N. benthamiana showed characteristics comparable with those of counterparts produced in mammalian cells. IgGs were tested for their therapeutic efficacy in the mouse toxic shock model using different challenge doses of SEB and a treatment with 200 μg of IgGs 1 h after SEB challenge. The lead candidates displayed full protection from lethal challenge over a wide range of SEB challenge doses. Furthermore, mice that were treated with anti-SEB IgG had significantly lower IFNγ and IL-2 levels in serum compared with mock-treated mice. In summary, these anti-SEB monoclonal antibodies represent excellent therapeutic candidates for further preclinical and clinical development. PMID:22645125

Frequency and Genotype of Human Parvovirus B19 among Iranian Hemodialysis and Peritoneal Dialysis Patients.

PubMed

Sharif, Alireza; Aghakhani, Arezoo; Velayati, Ali Akbar; Banifazl, Mohammad; Sharif, Mohammad Reza; Razeghi, Effat; Kheirkhah, Davood; Kazemimanesh, Monireh; Bavand, Anahita; Ramezani, Amitis

2016-01-01

The aim of this study was to evaluate the frequency and genotype of human parvovirus B19 and its relation with anemia among Iranian patients under dialysis. Fifty hemodialysis (HD) and 33 peritoneal dialysis (PD) patients were enrolled. B19 IgG and IgM antibodies were assessed by ELISA, and the presence of B19 DNA was evaluated by nested PCR. PCR products were sequenced directly and phylogenetic analysis was performed. In the HD group, the prevalence of B19 antibodies was 54% for IgG and 4% for IgM. B19 DNA was detected in 10% of the cases, and 10% showed B19 IgG and viremia simultaneously. In the PD group, the prevalence of B19 IgG and IgM was 57.6 and 0% respectively, whereas B19 DNA was found in 12.1% of the group. A total of 9.1% showed B19 IgG and viremia concurrently. There was no significant difference regarding anemia and B19 infection in either group. All B19 isolates were clustered in genotype 1A. Our findings indicate that B19 infection plays no role in leading chronic anemia in dialysis patients. However, persistent B19 viremia and the circulation of the same strains in dialysis patients may indicate a potential risk for the contamination of dialysis equipment and nosocomial spread of B19 infection within dialysis units. © 2017 S. Karger AG, Basel.

Toxocara canis, Trichinella spiralis and Taenia solium helminthozoonoses: seroprevalence among selected populations in north India.

PubMed

Singh, B B; Sharma, R; Gill, J P S

2015-09-01

Helminthozoonoses are being considered as a research priority in India and many other tropical and subtropical countries. Taenia solium and Trichinella spiralis are emerging public health and food safety issues in the country and the developing world. The asymptomatic Ta. solium carriers act as important risk for neurocysticercosis, leading to adult onset epilepsy in the country. Human toxocariasis is another common zoonosis which occurs due to larvae of Toxocara canis or T. cati. The current study was planned to obtain baseline seropositivity data for Ta. solium, To. canis and Tr. spiralis antibodies among selected populations in Punjab province of northern India. In the present study, 122 human subjects belonging to selected occupations viz. farmers and veterinary practitioners were screened using the RIDASCREEN(®) Ta. solium IgG, RIDASCREEN(®) Toxocara IgG and RIDASCREEN(®) Trichinella IgG enzyme immunoassays for the qualitative determination of IgG antibodies against Ta. solium, Tr. spiralis and To. canis, respectively in human serum. The seropositivity of To. canis, Tr. spiralis and Ta. solium infections were found to be 22.13, 5.73 and 11.47 %, respectively in human serum samples. The relative risk of being infected for To. canis, Tr. spiralis and Ta. solium infections was found to be 1.91 (95 % CI 0.786-4.669), 2.61 (95 % CI 0.3258-20.94) and 1.596 (95 % CI 0.427-5.3893) times high respectively in farmers when compared to veterinary practitioners. The present study indicates that exposure to To. canis and Ta. solium is not uncommon among farmers and veterinary practitioners in this part of the country. These results provided evidence of Tr. spiralis among selected human populations in the country and demand more research related to trichinellosis in their respective animal and human hosts.

Low pretransplant IgA level is associated with early post-lung transplant seromucous infection.

PubMed

Murthy, Sudish C; Avery, Robin K; Budev, Marie; Gupta, Sandeep; Pettersson, Gösta B; Nowicki, Edward R; Mehta, Atul; Chapman, Jeffrey T; Rajeswaran, Jeevanantham; Blackstone, Eugene H

2018-04-13

Infection is an important cause of morbidity and mortality after lung transplantation. Immunoglobulins are part of both seromucous (IgA) and serum (IgG) infection defense mechanisms. We therefore hypothesized that lower pretransplant IgA levels would be associated with more early post-lung transplant seromucous infections and greater mortality independent of IgG. From January 2000 to July 2010, 538 patients undergoing primary lung transplantation had pretransplant IgA (n = 429) and IgG (n = 488) measured as a clinical routine. Median IgA was 200 mg·dL -1 (2% < 70 mg·dL -1 , lower limit of normal); median IgG was 970 mg·dL -1 (5% < 600 mg·dL -1 ). Intensive microbiology review was used to categorize infections and their causative organisms within the first posttransplant year. In total, 397 seromucous infections were observed in 247 patients, most bacterial. Although IgA and IgG were moderately correlated (r = 0.5, P < .0001), low pretransplant IgA was a strong risk factor (P = .01) for seromucous infections, but pretransplant IgG was not (P ≥ .6). As pretransplant IgA levels fell below 200 mg·dL -1 , the risk of these posttransplant infections rose nearly linearly. Lower pretransplant levels of IgA were associated with greater posttransplant mortality to end of follow-up (P = .004), but pretransplant IgG was not (P ≥ .3). Low levels of preoperative IgA, an important immunoglobulin involved in mucosal immunologic defense, but not IgG, are associated with seromucous infections in the year after lung transplantation and increased follow-up mortality. It would appear prudent to identify patients with relative IgA deficiency at listing and to increase vigilance of monitoring for, and prophylaxis against, seromucous infection in this high-risk population. Copyright © 2018. Published by Elsevier Inc.

Chronic HIV-1 Infection Induces B-Cell Dysfunction That Is Incompletely Resolved by Long-Term Antiretroviral Therapy.

PubMed

Abudulai, Laila N; Fernandez, Sonia; Corscadden, Karli; Hunter, Michael; Kirkham, Lea-Ann S; Post, Jeffrey J; French, Martyn A

2016-04-01

To determine the effect of long-term antiretroviral therapy (ART) on HIV-1-induced B-cell dysfunction. Comparative study of ART-naive and ART-treated HIV-infected patients with non-HIV controls. B-cell dysfunction was examined in patients with HIV-1 infection (n = 30) who had received ART for a median time of 9.25 years (range: 1.3-21.7) by assessing proportions of CD21 B cells (a marker of B-cell exhaustion) and proportions of tumor necrosis factor-related apoptosis-inducing ligand or B and T lymphocyte attenuator B cells, and serum levels of immunoglobulin free light chains (markers of B-cell hyperactivation). The association of these markers with serum levels of IgG1 and IgG2, and production of IgG antibodies after vaccination with pneumococcal polysaccharides were also examined. ART-naive patients with HIV (n = 20) and controls (n = 20) were also assessed for comparison. ART-treated patients had increased proportions of CD21 and tumor necrosis factor-related apoptosis-inducing ligand B cells and, furthermore, although proportions of B and T lymphocyte attenuator B cells were not significantly different from controls, they correlated negatively with CD21 B cells. Proportions of CD21 B cells also correlated negatively with current CD4 T-cell counts. In ART-naive patients with HIV, free light chains correlated with CD21 B cells and IgG1, but not IgG2. Serum IgG2:IgG1 ratios were substantially lower than normal in patients with HIV and did not resolve on ART. In ART-treated patients, IgG antibody responses to pneumococcal polysaccharides after vaccination were not associated with markers of B-cell dysfunction. B-cell dysfunction persists in patients with HIV receiving long-term ART. The causes and consequences of this require further investigation.

Antibodies under pressure: A Small-Angle X-ray Scattering study of Immunoglobulin G under high hydrostatic pressure.

PubMed

König, Nico; Paulus, Michael; Julius, Karin; Schulze, Julian; Voetz, Matthias; Tolan, Metin

2017-12-01

In the present work two subclasses of the human antibody Immunoglobulin G (IgG) have been investigated by Small-Angle X-ray Scattering under high hydrostatic pressures up to 5kbar. It is shown that IgG adopts a symmetric T-shape in solution which differs significantly from available crystal structures. Moreover, high-pressure experiments verify the high stability of the IgG molecule. It is not unfolded by hydrostatic pressures of up to 5kbar but a slight increase of the radius of gyration was observed at elevated pressures. Copyright © 2017 Elsevier B.V. All rights reserved.

Prevalence and Risk Factors of Lassa Seropositivity in Inhabitants of the Forest Region of Guinea: A Cross-Sectional Study

PubMed Central

Kernéis, Solen; Koivogui, Lamine; Magassouba, N'Faly; Koulemou, Kekoura; Lewis, Rosamund; Aplogan, Aristide; Grais, Rebecca F.; Guerin, Philippe J.; Fichet-Calvet, Elisabeth

2009-01-01

Background Lassa fever is a viral hemorrhagic fever endemic in West Africa. The reservoir host of the virus is a multimammate rat, Mastomys natalensis. Prevalence estimates of Lassa virus antibodies in humans vary greatly between studies, and the main modes of transmission of the virus from rodents to humans remain unclear. We aimed to (i) estimate the prevalence of Lassa virus–specific IgG antibodies (LV IgG) in the human population of a rural area of Guinea, and (ii) identify risk factors for positive LV IgG. Methods and Findings A population-based cross-sectional study design was used. In April 2000, all individuals one year of age and older living in three prefectures located in the tropical secondary forest area of Guinea (Gueckedou, Lola and Yomou) were sampled using two-stage cluster sampling. For each individual identified by the sampling procedure and who agreed to participate, a standardized questionnaire was completed to collect data on personal exposure to potential risk factors for Lassa fever (mainly contact with rodents), and a blood sample was tested for LV IgG. A multiple logistic regression model was used to determine risk factors for positive LV IgG. A total of 1424 subjects were interviewed and 977 sera were tested. Prevalence of positive LV Ig was of 12.9% [10.8%–15.0%] and 10.0% [8.1%–11.9%] in rural and urban areas, respectively. Two risk factors of positive LV IgG were identified: to have, in the past twelve months, undergone an injection (odds ratio [OR] = 1.8 [1.1–3.1]), or lived with someone displaying a haemorrhage (OR = 1.7 [1.1–2.9]). No factors related to contacts with rats and/or mice remained statistically significant in the multivariate analysis. Conclusions Our study underlines the potential importance of person-to-person transmission of Lassa fever, via close contact in the same household or nosocomial exposure. PMID:19924222

Quantitation of blood lymphocytes secreting antibodies to pneumococcal polysaccharides after in vivo antigenic stimulation.

PubMed

Heilmann, C; Pedersen, F K

1986-02-01

An indirect plaque-forming cell assay detecting B cells secreting IgM, IgG and IgA antibodies against pneumococcal polysaccharides (PPS) is described. The numbers of anti-PPS-secreting cells (SC) and Ig-SC in the blood of normal persons immunized with a polyvalent PPS vaccine were quantitated. Anti-PPS-SC were recorded from the fourth to the twelfth post-vaccination day, and the maximum number was found between days 6 and 9. Quantitatively IgA anti-PPS-SC outnumbered the IgM and IgG anti-PPS-SC. Concomitant with the increase in the numbers of antibody-SC an increase in polyclonally activated IgM-, IgG- and IgA-SC was recorded. The specific anti-PPS-antibody-SC constituted 20-80% of the total numbers of Ig-SC from the sixth to the ninth post-vaccination day.

GingisKHAN™ protease cleavage allows a high-throughput antibody to Fab conversion enabling direct functional assessment during lead identification of human monoclonal and bispecific IgG1 antibodies

PubMed Central

Moelleken, Jörg; Gassner, Christian; Lingke, Sabine; Tomaschek, Simone; Tyshchuk, Oksana; Lorenz, Stefan; Mølhøj, Michael

2017-01-01

ABSTRACT The determination of the binding strength of immunoglobulins (IgGs) to targets can be influenced by avidity when the targets are soluble di- or multimeric proteins, or associated to cell surfaces, including surfaces introduced from heterogeneous assays. However, for the understanding of the contribution of a second drug-to-target binding site in molecular design, or for ranking of monovalent binders during lead identification, affinity-based assessment of the binding strength is required. Typically, monovalent binders like antigen-binding fragments (Fabs) are generated by proteolytic cleavage with papain, which often results in a combination of under- and over-digestion, and requires specific optimization and chromatographic purification of the desired Fabs. Alternatively, the Fabs are produced by recombinant approaches. Here, we report a lean approach for the functional assessment of human IgG1s during lead identification based on an in-solution digestion with the GingisKHAN™ protease, generating a homogenous pool of intact Fabs and Fcs and enabling direct assaying of the Fab in the digestion mixture. The digest with GingisKHAN™ is highly specific and quantitative, does not require much optimization, and the protease does not interfere with methods typically applied for lead identification, such as surface plasmon resonance or cell-based assays. GingisKHAN™ is highly suited to differentiate between affinity and avidity driven binding of human IgG1 monoclonal and bispecific antibodies during lead identification. PMID:28805498

Specific Antibody Deficiency: Controversies in Diagnosis and Management

PubMed Central

Perez, Elena; Bonilla, Francisco A.; Orange, Jordan S.; Ballow, Mark

2017-01-01

Specific antibody deficiency (SAD) is a primary immunodeficiency disease characterized by normal immunoglobulins (Igs), IgA, IgM, total IgG, and IgG subclass levels, but with recurrent infection and diminished antibody responses to polysaccharide antigens following vaccination. There is a lack of consensus regarding the diagnosis and treatment of SAD, and its clinical significance is not well understood. Here, we discuss current evidence and challenges regarding the diagnosis and treatment of SAD. SAD is normally diagnosed by determining protective titers in response to the 23-valent pneumococcal polysaccharide vaccine. However, the definition of an adequate response to immunization remains controversial, including the magnitude of response and number of pneumococcal serotypes needed to determine a normal response. Confounding these issues, anti-polysaccharide antibody responses are age- and probably serotype dependent. Therapeutic strategies and options for patients with SAD are often based on clinical experience due to the lack of focused studies and absence of a robust case definition. The mainstay of therapy for patients with SAD is antibiotic prophylaxis. However, there is no consensus regarding the frequency and severity of infections warranting antibiotic prophylaxis and no standardized regimens and no studies of efficacy. Published expert guidelines and opinions have recommended IgG therapy, which are supported by observations from retrospective studies, although definitive data are lacking. In summary, there is currently a lack of evidence regarding the efficacy of therapeutic strategies for patients with SAD. We believe that it is best to approach each patient as an individual and progress through diagnostic and therapeutic interventions together with existing practice guidelines. PMID:28588580

Long-Term Safety and Efficacy of Enzyme Replacement Therapyfor Fabry Disease

PubMed Central

Wilcox, William R.; Banikazemi, Maryam; Guffon, Nathalie; Waldek, Stephen; Lee, Philip; Linthorst, Gabor E.; Desnick, Robert J.; Germain, Dominique P.

2004-01-01

Elsewhere, we reported the safety and efficacy results of a multicenter phase 3 trial of recombinant human α-galactosidase A (rh-αGalA) replacement in patients with Fabry disease. All 58 patients who were enrolled in the 20-wk phase 3 double-blind, randomized, and placebo-controlled study received subsequently 1 mg/kg of rh-αGalA (agalsidase beta, Fabrazyme, Genzyme Corporation) biweekly in an ongoing open-label extension study. Evidence of long-term efficacy, even in patients who developed IgG antibodies against rh-αGalA, included the continuously normal mean plasma globotriaosylceramide (GL-3) levels during 30 mo of the extension study and the sustained capillary endothelial GL-3 clearance in 98% (39/40) of patients who had a skin biopsy taken after treatment for 30 mo (original placebo group) or 36 mo (original enzyme-treated group). The mean serum creatinine level and estimated glomerular filtration rate also remained stable after 30–36 mo of treatment. Infusion-associated reactions decreased over time, as did anti-rh-αGalA IgG antibody titers. Among seroconverted patients, after 30–36 mo of treatment, seven patients tolerized (no detectable IgG antibody), and 59% had ⩾4-fold reductions in antibody titers. As of 30 mo into the extension trial, three patients were withdrawn from the study because of positive serum IgE or skin tests; however, all have been rechallenged successfully at the time of this report. Thus, enzyme replacement therapy for 30–36 mo with agalsidase beta resulted in continuously decreased plasma GL-3 levels, sustained endothelial GL-3 clearance, stable kidney function, and a favorable safety profile. PMID:15154115

Long-term safety and efficacy of enzyme replacement therapy for Fabry disease.

PubMed

Wilcox, William R; Banikazemi, Maryam; Guffon, Nathalie; Waldek, Stephen; Lee, Philip; Linthorst, Gabor E; Desnick, Robert J; Germain, Dominique P

2004-07-01

Elsewhere, we reported the safety and efficacy results of a multicenter phase 3 trial of recombinant human alpha -galactosidase A (rh-alpha GalA) replacement in patients with Fabry disease. All 58 patients who were enrolled in the 20-wk phase 3 double-blind, randomized, and placebo-controlled study received subsequently 1 mg/kg of rh-alpha GalA (agalsidase beta, Fabrazyme, Genzyme Corporation) biweekly in an ongoing open-label extension study. Evidence of long-term efficacy, even in patients who developed IgG antibodies against rh- alpha GalA, included the continuously normal mean plasma globotriaosylceramide (GL-3) levels during 30 mo of the extension study and the sustained capillary endothelial GL-3 clearance in 98% (39/40) of patients who had a skin biopsy taken after treatment for 30 mo (original placebo group) or 36 mo (original enzyme-treated group). The mean serum creatinine level and estimated glomerular filtration rate also remained stable after 30-36 mo of treatment. Infusion-associated reactions decreased over time, as did anti-rh- alpha GalA IgG antibody titers. Among seroconverted patients, after 30-36 mo of treatment, seven patients tolerized (no detectable IgG antibody), and 59% had > or =4-fold reductions in antibody titers. As of 30 mo into the extension trial, three patients were withdrawn from the study because of positive serum IgE or skin tests; however, all have been rechallenged successfully at the time of this report. Thus, enzyme replacement therapy for 30-36 mo with agalsidase beta resulted in continuously decreased plasma GL-3 levels, sustained endothelial GL-3 clearance, stable kidney function, and a favorable safety profile.

Patch testing and allergen-specific serum IgE and IgG antibodies in the diagnosis of canine adverse food reactions.

PubMed

Bethlehem, Simone; Bexley, Jennifer; Mueller, Ralf S

2012-02-15

Adverse food reaction (AFR) is a common differential diagnosis for pruritic dogs. The only way to diagnose AFR is an elimination diet of 6-8 weeks with a protein and a carbohydrate source not previously fed. In humans, patch testing has been shown to be a useful tool to diagnose food allergies. In veterinary medicine, serum food allergen-specific antibody testing is widely offered to identify suitable ingredients for such diets. The aim of this study was to determine sensitivity, specificity, negative and positive predictability of patch testing with and serum antibody testing for a variety of common food stuffs. Twenty-five allergic dogs underwent an elimination diet and individual rechallenge with selected food stuffs, food patch testing and serum testing for food-antigen specific IgE and IgG. Eleven clinically normal control dogs only were subjected to patch and serum testing. The sensitivity and specificity of the patch test were 96.7 and 89.0% respectively, negative and positive predictability were 99.3 and 63.0%. For IgE and IgG the sensitivity was 6.7 and 26.7%, specificity were 91.4 and 88.3%, the negative predictive values 80.7 and 83.7% and the positive predictive values were 15.4 and 34.8%. Based on these results, a positive reaction of a dog on these tests is not very helpful, but a negative result indicates that this antigen is tolerated well. We conclude that patch testing (and to a lesser degree serum testing) can be helpful in choosing ingredients for an elimination diet in a dog with suspected AFR. Copyright © 2012. Published by Elsevier B.V.

Seroepidemiological Study of Epstein-Barr Virus in Different Population Groups in Croatia.

PubMed

Beader, Nataša; Kolarić, Branko; Slačanac, Domagoj; Tabain, Irena; Vilibić-Čavlek, Tatjana

2018-02-01

The Epstein-Barr virus (EBV) is one of the most common viruses found in humans, causing lifelong infection in up to 95% of the world population. To analyze the seroprevalence of EBV infection in different population groups in Croatia. During a 2 year period (2015-2016), a total of 2022 consecutive serum samples collected from Croatian residents were tested for the presence of EBV-specific viral capsid antigen (VCA) immunoglobulin M (IgM) and IgG antibodies using an enzyme-linked immunoassay. IgM/IgG-positive samples were further tested for IgG avidity. The overall prevalence of EBV IgG antibodies was 91.4%. Females had significantly higher IgG seroprevalence than males (93.1% vs. 89.9%, P = 0.008). According to age, IgG seropositivity increased progressively from 59.6% in children age < 9 years to 98.3% in 30-39 year olds, and remained stable thereafter (P < 0.001). The IgG seroprevalence differed significantly among groups: 68.1% in children/adolescents and 95.9% in adults; multiple sclerosis (100%), hemodialysis patients (97.7%), heart transplant recipients (93.8%), hematological malignancies (91.2%), and Crohn's disease (88.5%), P < 0.001. IgM antibodies were detected in 9% of participants. Using IgG avidity, recent primary EBV infection was documented in 83.8% of IgM-positive subjects < 9 years old, 69.2% age 10-19, 33.3% age 20-29, and 3.6-4.2% > 40. All IgM positive participants > 40 years showed high IgG avidity. Logistic regression showed that age is associated with EBV IgG seropositivity. EBV is widespread in the Croatian population. Older age appears to be the main risk factor for EBV seropositivity.

Immunologic Approach to the Identification and Development of Vaccines to Various Toxins

DTIC Science & Technology

1992-04-20

0.05 ml of a 1:2500 dilution of goat anti-mouse Ig conjugated to horse radish peroxidase (HRP, Fisher Scientific, Orangeburg, NY) were added to the...mouse immune sera were pooled and adsorbed over a normal horse IgG-agarose column. Normal horse 1gG was used because normal burro IgG is not readily...available, and because the horse is proba- bly the closest species to the burro in evolutionary terms. The adsorbed mouse sera were tested in ELISA

Immunocontraceptive efficacy of synthetic peptides corresponding to major antigenic determinants of chicken riboflavin carrier protein in the female rats.

PubMed

Subramanian, S; Karande, A A; Adiga, P R

2000-09-01

Earlier studies have demonstrated that antibodies directed towards the N-terminal (residues 10-17) and C-terminal (residues 200-207) regions on chicken riboflavin carrier protein (RCP; 219 AA) are effective in pregnancy termination in rodents and sub-human primates. In the present study, the immunocontraceptive potential of three additional immunodominant sequences comprising of residues 33-49, 64 83 and 130-147 (CYA, CED and CGE peptides, respectively) of chicken RCP was investigated. The three antigenic peptides were synthesized by using Fmoc chemistry. Oligoclonal antibodies were generated in rabbits. Bioneutralizing capacity of these peptides was assessed by passive and active immunoneutralization studies. All the three peptides-specific antisera recognized their cognate epitopes on native RCP. When the affinity purified peptide IgG were administered on three consecutive days to pregnant rats (on days 10, 11 and 12), it was observed that the rats injected with CED and CGE-IgG failed to deliver any pups whereas the animals which received CYA IgG delivered normal pups. Active immunization of fertile female rats with CED or CGE peptide conferred protection from pregnancy. These results demonstrate the presence of two additional stretches in chicken RCP which can serve as mini-vaccines.

T helper 2 and regulatory T-cell cytokine production by mast cells: a key factor in the pathogenesis of IgG4-related disease.

PubMed

Takeuchi, Mai; Sato, Yasuharu; Ohno, Kyotaro; Tanaka, Satoshi; Takata, Katsuyoshi; Gion, Yuka; Orita, Yorihisa; Ito, Toshihiro; Tachibana, Tomoyasu; Yoshino, Tadashi

2014-08-01

IgG4-related disease is a systemic disorder with unique clinicopathological features and uncertain etiological features and is frequently related to allergic disease. T helper 2 and regulatory T-cell cytokines have been reported to be upregulated in the affected tissues; thus, the production of these cytokines by T helper 2 and regulatory T cells has been suggested as an important factor in the pathogenesis of IgG4-related disease. However, it is not yet clear which cells produce these cytokines in IgG4-related disease, and some aspects of the disorder cannot be completely explained by T-cell-related processes. To address this, we analyzed paraffin-embedded sections of tissues from nine cases of IgG4-related submandibular gland disease, five cases of submandibular sialolithiasis, and six cases of normal submandibular gland in order to identify potential key players in the pathogenesis of IgG4-related disease. Real-time polymerase chain reaction analysis confirmed the significant upregulation of interleukin (IL)4, IL10, and transforming growth factor beta 1 (TGFβ1) in IgG4-related disease. Interestingly, immunohistochemical studies indicated the presence of mast cells expressing these cytokines in diseased tissues. In addition, dual immunofluorescence assays identified cells that were double-positive for each cytokine and for KIT, which is expressed by mast cells. In contrast, the distribution of T cells did not correlate with cytokine distribution in affected tissues. We also found that the mast cells were strongly positive for IgE. This observation supports the hypothesis that mast cells are involved in IgG4-related disease, as mast cells are known to be closely related to allergic reactions and are activated in the presence of elevated non-specific IgE levels. In conclusion, our results indicate that mast cells produce T helper 2 and regulatory T-cell cytokines in tissues affected by IgG4-related disease and possibly have an important role in disease pathogenesis.

Detection of circulating natural antibodies to inflammatory cytokines in type-2 diabetes and clinical significance.

PubMed

Cai, Weiyi; Qiu, Cailing; Zhang, Hongyu; Chen, Xiangyun; Zhang, Xuan; Meng, Qingyong; Wei, Jun

2017-01-01

Inflammatory cytokines have been demonstrated to be involved in developing insulin resistance and type-2 diabetes (T2D). Natural antibodies in the circulation have protective effects on common diseases in humans. The present study was thus designed to test the hypothesis that natural antibodies against inflammatory cytokines could be associated with T2D. An enzyme-linked immunosorbent assay (ELISA) was developed in-house to detect plasma IgG against peptide antigens derived from interleukin 1α (IL1α), IL1β, IL6, IL8 and tumor necrosis factor-α (TNF-α) in 200 patients with T2D and 220 control subjects. Binary regression showed that compared with control subjects, T2D patients had a decreased level of plasma anti-IL6 IgG (adjusted r 2 =0.034, p =0.0001), anti-IL8 IgG (adjusted r 2 =0.021, p =0.002) and anti-TNF-α IgG (adjusted r 2 =0.017, p =0.003). Female patients mainly contributed to decreased levels of anti-IL6 IgG (adjusted r 2 =0.065, p =0.0008) and anti-IL8 IgG (adjusted r 2 =0.056, p =0.003), while male patients mainly contributed to decreased anti-TNF-α IgG levels (adjusted r 2 =0.024, p =0.005). ROC curve analysis revealed a sensitivity of 16.5% against specificity of 95.5% for anti-IL6 IgG assay and a sensitivity of 19.5% against specificity of 95.9% for anti-IL8 IgG assay. Glycated hemoglobin levels measured after 6-month glucose-lowering treatment appeared to be inversely correlated with plasma anti-IL1α IgG ( r =-0.477, df=17, p =0.039) and anti-IL6 IgG ( r =-0.519, df=17, p =0.023) although such correlation failed to survive the Bonferroni correction. Deficiency of natural IgG against inflammatory cytokines is likely to be a risk factor for T2D development and detection of such antibodies may be useful for personalized treatment of the disease.

Ten cases of severe oral lichen planus showing granular C3 deposition in oral mucosal basement membrane zone.

PubMed

Hashimoto, Takashi; Fukuda, Aoi; Himejima, Akio; Morita, Shosuke; Tsuruta, Daisuke; Koga, Hiroshi; Krol, Rafal P; Ishii, Norito

2015-01-01

Oral lichen planus (OLP) may show depositions of immunoglobulins and complement components in oral mucosal basement membrane zone (BMZ) in direct immunofluorescence, although these finding are not frequently seen. We collected and examined ten cases of severe OLP showing granular C3 deposition in BMZ. In addition to clinical, histopathological and direct immunofluorescence assessments, we performed various immune-serological tests, including indirect immunofluorescence of normal human skin and 1M NaCl-split skin, immunoblotting of normal human epidermal and dermal extracts, recombinant proteins of BP180 NC16a and C-terminal domains, concentrated culture supernatant of HaCaT cells and purified human laminin-332, and enzyme-linked immunosorbent assays for BP230 and BP180. Direct immunofluorescence showed C3 deposition in BMZ exclusively of granular pattern in 7 cases and of both granular and linear patterns in 3 cases. The 10 cases showed no positive reactivity for either IgG or IgA antibodies in any immuno-serological tests. Detailed analyses of clinical, histopathological and immunological findings revealed striking female prevalence, although other parameters were in general characteristic of OLP. Granular C3 deposition in oral BMZ may be one of the characteristic features of severe OLP, although mechanisms for C3 deposition and its pathogenic role in OLP are currently unknown.

Enterovirus 71 viral capsid protein linear epitopes: Identification and characterization

PubMed Central

2012-01-01

Background To characterize the human humoral immune response against enterovirus 71 (EV71) infection and map human epitopes on the viral capsid proteins. Methods A series of 256 peptides spanning the capsid proteins (VP1, VP2, VP3) of BJ08 strain (genomic C4) were synthesized. An indirect enzyme-linked immunosorbent assay (ELISA) was carried out to detect anti-EV71 IgM and IgG in sera of infected children in acute or recovery phase. The partially overlapped peptides contained 12 amino acids and were coated in the plate as antigen (0.1 μg/μl). Sera from rabbits immunized with inactivated BJ08 virus were also used to screen the peptide panel. Results A total of 10 human anti-EV71 IgM epitopes (vp1-14 in VP1; vp2-6, 21, 40 and 50 in VP2 and vp3-10, 12, 15, 24 and 75 in VP3) were identified in acute phase sera. In contrast, only one anti-EV71 IgG epitope in VP1 (vp1-15) was identified in sera of recovery stage. Four rabbit anti-EV71 IgG epitopes (vp1-14, 31, 54 and 71) were identified and mapped to VP1. Conclusion These data suggested that human IgM epitopes were mainly mapped to VP2 and VP3 with multi-epitope responses occurred at acute infection, while the only IgG epitope located on protein VP1 was activated in recovery phase sera. The dynamic changes of humoral immune response at different stages of infection may have public health significance in evaluation of EV71 vaccine immunogenicity and the clinical application of diagnostic reagents. PMID:22264266

Immunofluorescent studies on human spermatozoa. III. Immunoglobulin classes of human spermatozoal antibodies

PubMed Central

Hansen, K. Brogaard

1972-01-01

Antibodies in human sera against four different antigens of human spermatozoa discovered by means of an indirect two-layer immunofluorescence technique (IFT) were characterized by determination of the class of immunoglobulins to which they belonged. A three-layer IFT using monospecific antisera against human IgG, IgA or IgM as the second layer was employed together with fractionation of sera on Sephadex G-200 or DEAE-cellulose followed by testing of the concentrated pools in a two-layer IFT. The study revealed that antibodies against the antigen in the front part of the acrosome were primarily IgM and those against the antigen in the tail primarily IgG. Antibodies against antigens in the equatorial segment and the postnuclear cap showed a varying predominance of these two immunoglobulins. Spermatozoal antibody as IgA was found only in small amounts. PMID:4558409

Investigation of the prevalence of antibody immunodeficiency in a polio endemic area in India.

PubMed

Mohanty, Madhu C; Deshpande, Jagadish M

2014-05-01

Protection against paralytic poliomyelitis is provided mainly by antibody mediated host defense. Despite intensive oral polio vaccine (OPV) immunization campaigns wild poliovirus transmission could not be stopped in Uttar Pradesh (UP) and Bihar states of India by the end of 2010. The objective of our study was to quantitate serum IgG and IgA in children of western UP, India, to determine the prevalence of antibody immunodeficiency. A cross-sectional survey for IgG and IgA concentrations in serum samples from healthy children and children with acute flaccid paralysis (AFP), up to the age of 5 years, was performed using sandwich ELISA. The overall mean IgG concentration for 1882 children of western UP, India, was 10.57 ± 4.53 (SD) g/L and mean IgA concentration for 979 children was 1.2 ± 0.818 g/L. Two 7-month-old female children had IgG levels below 2 g/L and there was an absence of neutralizing polio antibodies. The mean serum IgG level of children with AFP (n=979) was lower than levels observed in healthy children (n=903). The proportion of children with IgG levels below 2 g/L and IgA levels below 0.07 g/L was 0.7% in both healthy children and AFP cases. There was no abnormal prevalence of immunodeficiency in children in western UP which could have delayed achieving the eradication of polio in the state. The immunoglobulin levels reported here may be used as age-specific normal values for Indian children.

Bee sting allergy in beekeepers.

PubMed

Eich-Wanger, C; Müller, U R

1998-10-01

Beekeepers are strongly exposed to honey bee stings and therefore at an increased risk to develop IgE-mediated allergy to bee venom. We wondered whether bee venom-allergic beekeepers were different from normally exposed bee venom-allergic patients with regard to clinical and immunological parameters as well as their response to venom immunotherapy. Among the 459 bee venom-allergic patients seen over the 5 year period 1987-91, 62 (14%) were beekeepers and 44 (10%) family members of beekeepers. These two groups were compared with 101 normally exposed bee venom-allergic patients matched with the allergic beekeepers for age and sex, regarding clinical parameters, skin sensitivity, specific IgE and IgG antibodies to bee venom as well as safety and efficacy of venom immunotherapy. As expected, allergic beekeepers had been stung most frequently before the first allergic reaction. The three groups showed a similar severity of allergic symptoms following bee stings and had an equal incidence of atopic diseases. Allergic beekeepers showed higher levels of bee venom-specific serum IgG, lower skin sensitivity and lower levels of bee venom specific serum IgE than bee venom-allergic control patients. A negative correlation between number of stings and skin sensitivity as well as specific IgE was found in allergic beekeepers and their family members, while the number of stings was positively correlated with specific IgG in these two groups. Venom immunotherapy was equally effective in the three groups, but better tolerated by allergic beekeepers than the two other groups. The majority of allergic beekeepers continued bee-keeping successfully under the protection of venom immunotherapy. The lower level of sensitivity in diagnostic tests and the better tolerance of immunotherapy in allergic beekeepers is most likely related to the high level of specific IgG in this group.

[Vaccination of rhesus monkeys with recombinant antigen fragments and protection from hepatitis E virus infection].

PubMed

Ma, Yan-bing; Xie, Tian-hong; Zhang, Guang-ming; Li, Chun-hong; Dai, Xie-Jie; Dai, Chang-bai; Sun, Mao-sheng; Lu, Jian; Bi, Sheng-li

2002-12-01

To observe anti-HEV IgG response to vaccination of recombinant antigen fragments and evaluate its protection from Hepatitis E Virus infection in rhesus monkeys (Macaca mulatta). Twelve monkeys were divided into three groups and immunized respectively with three different recombinant antigens: namely Ag1 (carboxyl terminal 431 amino acids of ORF2), Ag2 (128aa fragment at the carboxyl terminal of ORF2), and Ag3 (full length ORF3 ligated with two ORF2 fragments encoded by 6743-7126nt and 6287-6404nt). The monkeys were challenged intravenously with fecal suspension from experimentally infected rhesus monkeys, and the other three monkeys served as the placebo group for challenge with HEV. The dynamic changes of the levels of ALT and anti-HEV IgG were examined. Pathological changes of liver tissue were observed by light microscope. Excretion of virus was detected by RT-nPCR. Hepatic histopathology of two monkeys in the placebo group was consistent with acute viral hepatitis, and ALT was elevated 3-4 weeks after inoculated with virus, up to 10-20 times higher than normal level. The liver tissue of monkeys immunized with antigen kept normal, ALT in several monkeys elevated mildly, and anti-HEV IgG conversation occurred at 1-2 weeks after vaccination, with the titer reaching 1:12,800. The virus RNA could be detected by RT-nPCR from days 7 to 50 in monkeys of control group, and from days 7 to 21 in vaccinated monkeys after challenged with virus. The recombinant antigens could induce the production of anti-HEV IgG, which protected rhesus monkeys from acute Hepatitis symptoms related to HEV infection.

Elimination of soluble sup 123 I-labeled aggregates of IgG in patients with systemic lupus erythematosus. Effect of serum IgG and numbers of erythrocyte complement receptor type 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Halma, C.; Breedveld, F.C.; Daha, M.R.

1991-04-01

Using soluble {sup 123}I-labeled aggregates of human IgG ({sup 123}I-AHIgG) as a probe, we examined the function of the mononuclear phagocyte system in 22 patients with systemic lupus erythematosus (SLE) and 12 healthy controls. In SLE patients, a decreased number of erythrocyte complement receptor type 1 was associated with less binding of {sup 123}I-AHIgG to erythrocytes and a faster initial rate of elimination of {sup 123}I-AHIgG (mean +/- SEM half-maximal clearance time 5.23 +/- 0.2 minutes, versus 6.58 +/- 0.2 minutes in the controls), with possible spillover of the material outside the mononuclear phagocyte system of the liver and spleen.more » However, multiple regression analysis showed that serum concentrations of IgG were the most important factor predicting the rate of {sup 123}I-AHIgG elimination. IgG concentration may thus reflect immune complex clearance, which in turn, would influence the inflammatory reaction, in SLE.« less

Raman spectroscopy based screening of IgG positive and negative sera for dengue virus infection

NASA Astrophysics Data System (ADS)

Bilal, M.; Saleem, M.; Bial, Maria; Khan, Saranjam; Ullah, Rahat; Ali, Hina; Ahmed, M.; Ikram, Masroor

2017-11-01

A quantitative analysis for the screening of immunoglobulin-G (IgG) positive human sera samples is presented for the dengue virus infection. The regression model was developed using 79 samples while 20 samples were used to test the performance of the model. The R-square (r 2) value of 0.91 was found through a leave-one-sample-out cross validation method, which shows the validity of this model. This model incorporates the molecular changes associated with IgG. Molecular analysis based on regression coefficients revealed that myristic acid, coenzyme-A, alanine, arabinose, arginine, vitamin C, carotene, fumarate, galactosamine, glutamate, lactic acid, stearic acid, tryptophan and vaccenic acid are positively correlated with IgG; while amide III, collagen, proteins, fatty acids, phospholipids and fucose are negatively correlated. For blindly tested samples, an excellent agreement has been found between the model predicted, and the clinical values of IgG. The parameters, which include sensitivity, specificity, accuracy and the area under the receiver operator characteristic curve, are found to be 100%, 83.3%, 95% and 0.99, respectively, which confirms the high quality of the model.

A novel antibody engineering strategy for making monovalent bispecific heterodimeric IgG antibodies by electrostatic steering mechanism.

PubMed

Liu, Zhi; Leng, Esther C; Gunasekaran, Kannan; Pentony, Martin; Shen, Min; Howard, Monique; Stoops, Janelle; Manchulenko, Kathy; Razinkov, Vladimir; Liu, Hua; Fanslow, William; Hu, Zhonghua; Sun, Nancy; Hasegawa, Haruki; Clark, Rutilio; Foltz, Ian N; Yan, Wei

2015-03-20

Producing pure and well behaved bispecific antibodies (bsAbs) on a large scale for preclinical and clinical testing is a challenging task. Here, we describe a new strategy for making monovalent bispecific heterodimeric IgG antibodies in mammalian cells. We applied an electrostatic steering mechanism to engineer antibody light chain-heavy chain (LC-HC) interface residues in such a way that each LC strongly favors its cognate HC when two different HCs and two different LCs are co-expressed in the same cell to assemble a functional bispecific antibody. We produced heterodimeric IgGs from transiently and stably transfected mammalian cells. The engineered heterodimeric IgG molecules maintain the overall IgG structure with correct LC-HC pairings, bind to two different antigens with comparable affinity when compared with their parental antibodies, and retain the functionality of parental antibodies in biological assays. In addition, the bispecific heterodimeric IgG derived from anti-HER2 and anti-EGF receptor (EGFR) antibody was shown to induce a higher level of receptor internalization than the combination of two parental antibodies. Mouse xenograft BxPC-3, Panc-1, and Calu-3 human tumor models showed that the heterodimeric IgGs strongly inhibited tumor growth. The described approach can be used to generate tools from two pre-existent antibodies and explore the potential of bispecific antibodies. The asymmetrically engineered Fc variants for antibody-dependent cellular cytotoxicity enhancement could be embedded in monovalent bispecific heterodimeric IgG to make best-in-class therapeutic antibodies. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Optimization of Photoactive Protein Z for Fast and Efficient Site-Specific Conjugation of Native IgG

PubMed Central

2015-01-01

Antibody conjugates have been used in a variety of applications from immunoassays to drug conjugates. However, it is becoming increasingly clear that in order to maximize an antibody’s antigen binding ability and to produce homogeneous antibody-conjugates, the conjugated molecule should be attached onto IgG site-specifically. We previously developed a facile method for the site-specific modification of full length, native IgGs by engineering a recombinant Protein Z that forms a covalent link to the Fc domain of IgG upon exposure to long wavelength UV light. To further improve the efficiency of Protein Z production and IgG conjugation, we constructed a panel of 13 different Protein Z variants with the UV-active amino acid benzoylphenylalanine (BPA) in different locations. By using this panel of Protein Z to cross-link a range of IgGs from different hosts, including human, mouse, and rat, we discovered two previously unknown Protein Z variants, L17BPA and K35BPA, that are capable of cross-linking many commonly used IgG isotypes with efficiencies ranging from 60% to 95% after only 1 h of UV exposure. When compared to existing site-specific methods, which often require cloning or enzymatic reactions, the Protein Z-based method described here, utilizing the L17BPA, K35BPA, and the previously described Q32BPA variants, represents a vastly more accessible and efficient approach that is compatible with nearly all native IgGs, thus making site-specific conjugation more accessible to the general research community. PMID:25121619

Optimization of photoactive protein Z for fast and efficient site-specific conjugation of native IgG.

PubMed

Hui, James Z; Tsourkas, Andrew

2014-09-17

Antibody conjugates have been used in a variety of applications from immunoassays to drug conjugates. However, it is becoming increasingly clear that in order to maximize an antibody's antigen binding ability and to produce homogeneous antibody-conjugates, the conjugated molecule should be attached onto IgG site-specifically. We previously developed a facile method for the site-specific modification of full length, native IgGs by engineering a recombinant Protein Z that forms a covalent link to the Fc domain of IgG upon exposure to long wavelength UV light. To further improve the efficiency of Protein Z production and IgG conjugation, we constructed a panel of 13 different Protein Z variants with the UV-active amino acid benzoylphenylalanine (BPA) in different locations. By using this panel of Protein Z to cross-link a range of IgGs from different hosts, including human, mouse, and rat, we discovered two previously unknown Protein Z variants, L17BPA and K35BPA, that are capable of cross-linking many commonly used IgG isotypes with efficiencies ranging from 60% to 95% after only 1 h of UV exposure. When compared to existing site-specific methods, which often require cloning or enzymatic reactions, the Protein Z-based method described here, utilizing the L17BPA, K35BPA, and the previously described Q32BPA variants, represents a vastly more accessible and efficient approach that is compatible with nearly all native IgGs, thus making site-specific conjugation more accessible to the general research community.

Heterogeneous distribution of antigens on human platelets demonstrated by fluorescence flow cytometry.

PubMed

Dunstan, R A; Simpson, M B

1985-12-01

We have used fluorescence flow cytometry to analyse cell-to-cell variability in the density of platelet ABH, Ii, Lewis, P, P1A1, Bak,a and HLA class I antigens. Human IgG and IgM antibodies were used in a two-stage assay with goat FITC-conjugated antihuman IgG (H&L) antibody as the label, followed by single cell analysis of 10 000 platelets per sample using a 256-channel fluorescence flow cytometer (Becton-Dickinson FACS Analyser). Computer analysis of fluorescence intensity histograms for mean and peak channel and coefficient of variation shows that the degree of heterogeneity in platelet antigen density varies with each particular blood group. The broad fluorescence distribution curves with oligosaccharide antigens (CVs: A = 53, B = 40, I = 44, Lea = 40, P = 40) indicate that these antigens possess a greater variability in the number of sites per cell compared to the more homogeneous distribution of P1,A1 BaK,a and HLA (CVs: P1A1 = 24, HLA = 30). These findings may partly account for the mechanism by which transfusion of ABO-incompatible platelets results in a biphasic survival curve, with a period of early rapid removal of those platelets with a high density of antigen sites, followed by a relatively normal survival curve for those platelets that possess only a few or no antigen sites. In contrast, P1A1 and HLA sites are less variable in number from one platelet to another in a given donor, and immune-mediated removal would be more likely to approximate a single exponential curve.

Toxoplasmosis in Caribbean islands: Seroprevalence in pregnant women in ten countries, and isolation and report of new genetic types of Toxoplasma gondii from dogs from St. Kitts, West Indies

USDA-ARS?s Scientific Manuscript database

Little is known of clinical toxoplasmosis in humans and animals in the Caribbean countries. We investigated the prevalence of IgG and IgMantibodies in 437 pregnant women from 10 English speaking Caribbean countries. Antibodies (IgG) to T. gondii (modified agglutination test, MAT, cut-off 1:6) were f...

Productivity and some properties of egg yolk antibody (IgY) against human rotavirus compared with rabbit IgG.

PubMed

Hatta, H; Tsuda, K; Akachi, S; Kim, M; Yamamoto, T

1993-03-01

Productivity and some properties of anti-Human Rotavirus (HRV) hen egg yolk antibody (IgY) were compared with those of anti-HRV rabbit serum antibody (IgG). The hens immunized with HRV (Wa strain, serotype 1 and Mo strain, serotype 3) were found to continuously to lay eggs without any change in the egg laying rate and the yolk of the eggs laid over a year showed a high level of neutralization titer against HRV. The production of anti-HRV IgY by a hen (one year) was at least 15 times (anti-Wa) and 120 times (anti-Mo) more effective than those by an immunized rabbit in the neutralization titer of the antibodies. The stability of anti-HRV IgY at temperature above 70 degrees C and low pH 2-3 was less than that of anti-HRV rabbit IgG. The temperature corresponding to the maximum of denaturation endotherm (Tmax) of IgY was 73.9 degrees C while that of rabbit IgG was 77.0 degrees C in the analysis by differential scanning calorimetry. This discrepancy in heat and acidic pH stability found between the two antibodies as discussed with regard to their protein structures.

[Effects on serum myelin proteins of n-hexane exposure].

PubMed

Yi, Juan; Zhou, Wei; He, Jia-xi; Liu, Qing-jun; Huang, Xian-qing

2011-02-01

Exploring the effects of n-hexane on expression of serum myelin proteins in occupational exposure workers, and finding the early biomarker of n-hexane exposure. In the study, 373 subjects were recruited, 269 exposure workers (work experience of more than1 year) and 104 non-exposure workers were selected. Firstly examined the level of urinary 2,5-hexanedione in the two groups, based on urinary 2,5-hexanedione biological limit value (4 mg/L), the exposed group was divided into high-exposed group and low-exposed group. And then collected blood samples and extracted serum. Human peripheral myelin protein zero (P0) antibody (IgG, IgM) and human peripheral myelin protein two (P2) antibody (IgG, IgM) analysis was performed according to ELISA kit. The concentration of urinary 2,5-hexanedione in the exposed group was (3.10 ± 1.35) mg/L. The level of P0 antibody (IgG, IgM) and P2 antibody (IgG, IgM) in the high-exposed group and low-exposed group were both higher than that in the controls (P < 0.01). P0 antibody and P2 antibody could be used as the early biomarkers of n-hexane exposure, which not only evaluate the occupational hazards in the early, but also provide the policy maker with scientific evidence.

Chronic cat allergen exposure induces a TH2 cell-dependent IgG4 response related to low sensitization.

PubMed

Renand, Amedee; Archila, Luis D; McGinty, John; Wambre, Erik; Robinson, David; Hales, Belinda J; Thomas, Wayne R; Kwok, William W

2015-12-01

In human subjects, allergen tolerance has been observed after high-dose allergen exposure or after completed allergen immunotherapy, which is related to the accumulation of anti-inflammatory IgG4. However, the specific T-cell response that leads to IgG4 induction during chronic allergen exposure remains poorly understood. We sought to evaluate the relationship between cat allergen-specific T-cell frequency, cat allergen-specific IgE and IgG4 titers, and clinical status in adults with cat allergy with and without cat ownership and the cellular mechanism by which IgG4 is produced. Fel d 1-, Fel d 4-, Fel d 7-, and Fel d 8-specific T-cell responses were characterized by CD154 expression after antigen stimulation. In allergic subjects without cat ownership, the frequency of cat allergen (Fel d 1 and Fel d 4)-specific TH2 (sTH2) cells correlates with higher IgE levels and is linked to asthma. Paradoxically, we observed that subjects with cat allergy and chronic cat exposure maintain a high frequency of sTH2 cells, which correlates with higher IgG4 levels and low sensitization. B cells from allergic, but not nonallergic subjects, are able to produce IgG4 after cognate interactions with sTH2 clones and Fel d 1 peptide or the Fel d 1 recombinant protein. These experiments suggest that (1) allergen-experienced B cells with the capacity to produce IgG4 are present in allergic subjects and (2) cat allergen exposure induces an IgG4 response in a TH2 cell-dependent manner. Thus IgG4 accumulation could be mediated by chronic activation of the TH2 response, which in turn drives desensitization. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. All rights reserved.

Human Antibody Response to Aedes aegypti Saliva in an Urban Population in Bolivia: A New Biomarker of Exposure to Dengue Vector Bites

PubMed Central

Doucoure, Souleymane; Mouchet, François; Cournil, Amandine; Le Goff, Gilbert; Cornelie, Sylvie; Roca, Yelin; Giraldez, Mabel Guerra; Simon, Zaira Barja; Loayza, Roxanna; Misse, Dorothée; Flores, Jorge Vargas; Walter, Annie; Rogier, Christophe; Herve, Jean Pierre; Remoue, Franck

2012-01-01

Aedes mosquitoes are important vectors of re-emerging diseases in developing countries, and increasing exposure to Aedes in the developed world is currently a source of concern. Given the limitations of current entomologic methods, there is a need for a new effective way for evaluating Aedes exposure. Our objective was to evaluate specific antibody responses to Aedes aegypti saliva as a biomarker for vector exposure in a dengue-endemic urban area. IgG responses to saliva were strong in young children and steadily waned with age. Specific IgG levels were significantly higher in persons living in sites with higher Ae. aegypti density, as measured by using entomologic parameters. Logistic regression showed a significant correlation between IgG to saliva and exposure level, independently of either age or sex. These results suggest that antibody responses to saliva could be used to monitor human exposure to Aedes bites. PMID:22848099

A method for high-throughput, sensitive analysis of IgG Fc and Fab glycosylation by capillary electrophoresis.

PubMed

Mahan, Alison E; Tedesco, Jacquelynne; Dionne, Kendall; Baruah, Kavitha; Cheng, Hao D; De Jager, Philip L; Barouch, Dan H; Suscovich, Todd; Ackerman, Margaret; Crispin, Max; Alter, Galit

2015-02-01

The N-glycan of the IgG constant region (Fc) plays a central role in tuning and directing multiple antibody functions in vivo, including antibody-dependent cellular cytotoxicity, complement deposition, and the regulation of inflammation, among others. However, traditional methods of N-glycan analysis, including HPLC and mass spectrometry, are technically challenging and ill suited to handle the large numbers of low concentration samples analyzed in clinical or animal studies of the N-glycosylation of polyclonal IgG. Here we describe a capillary electrophoresis-based technique to analyze plasma-derived polyclonal IgG-glycosylation quickly and accurately in a cost-effective, sensitive manner that is well suited for high-throughput analyses. Additionally, because a significant fraction of polyclonal IgG is glycosylated on both Fc and Fab domains, we developed an approach to separate and analyze domain-specific glycosylation in polyclonal human, rhesus and mouse IgGs. Overall, this protocol allows for the rapid, accurate, and sensitive analysis of Fc-specific IgG glycosylation, which is critical for population-level studies of how antibody glycosylation may vary in response to vaccination or infection, and across disease states ranging from autoimmunity to cancer in both clinical and animal studies. Copyright © 2014 Elsevier B.V. All rights reserved.

Pertussis serology: assessment of IgG anti-PT ELISA for replacement of the CHO cell assay*

PubMed Central

DALBY, TINE; SØRENSEN, CHARLOTTE; PETERSEN, JESPER WESTPHAL; KROGFELT, KAREN ANGELIKI

2010-01-01

Dalby T, Sørensen C, Petersen JW, Krogfelt KA. Pertussis serology: assessment of IgG anti-PT ELISA for replacement of the CHO cell assay. APMIS 2010; 118: 968–72. Two types of serological assays are commonly used for the assessment of pertussis vaccine-induced antibodies; the Chinese hamster ovary cell (CHO cell) assay and the immunoglobulin G (IgG) anti pertussis toxin (PT) enzyme-linked immunosorbent assay (IgG anti-PT ELISA). Recently, both the techniques have been modified to improve performance with sera with interfering activity (CHO cell assay) or with heat-treated sera (IgG anti-PT ELISA). These two improved techniques were compared by the analysis of 100 individual serum samples from a previous clinical trial and 213 sera from a longitudinal serum collection from 20 Danish adults recently vaccinated with the Danish acellular pertussis vaccine. The comparison showed a significant linear correlation between the results of the two assays with a p-value of <0.0001 for the 100 individual samples. We, therefore, conclude that the improved IgG anti-PT ELISA can be used as a replacement for the often troublesome and time-consuming CHO cell assay for the measurement of vaccine-induced human antibodies to PT. PMID:21091778

Structural insights into the interaction of human IgG1 with FcγRI: no direct role of glycans in binding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oganesyan, Vaheh, E-mail: oganesyanv@medimmune.com; Mazor, Yariv; Yang, Chunning

In an effort to identify the critical structural features responsible for the high-affinity interaction of IgG1 Fc with FcγRI, the structure of the corresponding complex was solved at a resolution of 2.4 Å. The three-dimensional structure of a human IgG1 Fc fragment bound to wild-type human FcγRI is reported. The structure of the corresponding complex was solved at a resolution of 2.4 Å using molecular replacement; this is the highest resolution achieved for an unmutated FcγRI molecule. This study highlights the critical structural and functional role played by the second extracellular subdomain of FcγRI. It also explains the long-known majormore » energetic contribution of the Fc ‘LLGG’ motif at positions 234–237, and particularly of Leu235, via a ‘lock-and-key’ mechanism. Finally, a previously held belief is corrected and a differing view is offered on the recently proposed direct role of Fc carbohydrates in the corresponding interaction. Structural evidence is provided that such glycan-related effects are strictly indirect.« less

Immune responses of mice and human breast cancer patients following immunization with synthetic sialyl-Tn conjugated to KLH plus detox adjuvant.

PubMed

Longenecker, B M; Reddish, M; Koganty, R; MacLean, G D

1993-08-12

We generated a synthetic epitope, NANA alpha(2-6) GalNAc alpha-O-Crotyl (STn-crotyl), designed to "mimic" the natural O-linked epitope expressed on human carcinoma cells, NANA alpha(2-6)GalNAc alpha-O-Serine (STn-serine). STn-crotyl was conjugated to the carrier protein KLH through the crotyl linker arm, and a "vaccine" containing STn-KLH plus DETOX adjuvant was formulated. The immunogenicity of the vaccine was evaluated preclinically in CAF1 mice and subsequently in patients with metastatic breast cancer. The specificity and titers of IgG antibodies were evaluated by kinetic ELISA on synthetic STn-HSA and on ovine submaxillary mucin (OSM) solid phases. Ovine submaxillary mucin is a convenient source of repeating, natural O-linked STn-serine structures. Mice immunized three times with as little as 0.25 micrograms of STn-KLH produced IgG titers ranging from 1:10(4) to 1:10(5) when tested on solid phase OSM. Anti-OSM IgG, both polyclonal and monoclonal antibodies, generated from these mice were completely inhibited in their binding to solid phase OSM equally well by STn-serine and STn-crotyl synthetic haptens but not by several other closely related synthetic haptens. These monoclonal antibodies also bound to STn determinants on human tumor cell surfaces. Breast cancer patients immunized with 100 micrograms of the same vaccine produced median peak IgG titers 1:1280 measured on STn-HSA and 1:160 on OSM. Hapten inhibition experiments with the human sera demonstrated the specificities of the IgG antibodies for STn-crotyl and STn-serine, but not against several other related synthetic haptens. We found little evidence that the artificial linker arm (crotyl linker) contributed substantially to either the titer or affinity of the antibodies generated in either mice or human breast cancer patients. This suggests that the antibodies recognized the cancer-associated disaccharide NANA alpha(2-->6)-GalNAc. Small but not large doses of STn-KLH immunogen induced anti-STn DTH responses in mice that were inversely proportional to the antibody responses. Evidence of a clinical response was noted in some of the immunized breast cancer patients, with other patients showing prolonged disease stability.

Identification of conformational epitopes for human IgG on Chemotaxis inhibitory protein of Staphylococcus aureus

PubMed Central

Gustafsson, Erika; Haas, Pieter-Jan; Walse, Björn; Hijnen, Marcel; Furebring, Christina; Ohlin, Mats; van Strijp, Jos AG; van Kessel, Kok PM

2009-01-01

Background The Chemotaxis inhibitory protein of Staphylococcus aureus (CHIPS) blocks the Complement fragment C5a receptor (C5aR) and formylated peptide receptor (FPR) and is thereby a potent inhibitor of neutrophil chemotaxis and activation of inflammatory responses. The majority of the healthy human population has antibodies against CHIPS that have been shown to interfere with its function in vitro. The aim of this study was to define potential epitopes for human antibodies on the CHIPS surface. We also initiate the process to identify a mutated CHIPS molecule that is not efficiently recognized by preformed anti-CHIPS antibodies and retains anti-inflammatory activity. Results In this paper, we panned peptide displaying phage libraries against a pool of CHIPS specific affinity-purified polyclonal human IgG. The selected peptides could be divided into two groups of sequences. The first group was the most dominant with 36 of the 48 sequenced clones represented. Binding to human affinity-purified IgG was verified by ELISA for a selection of peptide sequences in phage format. For further analysis, one peptide was chemically synthesized and antibodies affinity-purified on this peptide were found to bind the CHIPS molecule as studied by ELISA and Surface Plasmon Resonance. Furthermore, seven potential conformational epitopes responsible for antibody recognition were identified by mapping phage selected peptide sequences on the CHIPS surface as defined in the NMR structure of the recombinant CHIPS31–121 protein. Mapped epitopes were verified by in vitro mutational analysis of the CHIPS molecule. Single mutations introduced in the proposed antibody epitopes were shown to decrease antibody binding to CHIPS. The biological function in terms of C5aR signaling was studied by flow cytometry. A few mutations were shown to affect this biological function as well as the antibody binding. Conclusion Conformational epitopes recognized by human antibodies have been mapped on the CHIPS surface and amino acid residues involved in both antibody and C5aR interaction could be defined. This information has implications for the development of an effective anti-inflammatory agent based on a functional CHIPS molecule with low interaction with human IgG. PMID:19284584

The intrinsic pathogenic role of autoantibodies to aquaporin 4 mediating spinal cord disease in a rat passive-transfer model

PubMed Central

Geis, Christian; Ritter, Christian; Ruschil, Christoph; Weishaupt, Andreas; Grünewald, Benedikt; Stoll, Guido; Holmoy, Trygve; Misu, Tatsuro; Fujihara, Kazuo; Hemmer, Bernhard; Stadelmann, Christine; Bennett, Jeffrey L.; Sommer, Claudia; Toyka, Klaus V.

2015-01-01

Neuromyelitis optica (NMO) is causally linked to autoantibodies (ABs) against aquaporin 4 (AQP4). Here, we focused on the pathogenic effects exclusively mediated by human ABs to AQP4 in vivo. We performed cell-free intrathecal (i.th.) passive transfer experiments in Lewis rats using purified patient NMO immunoglobulin G (IgG) and various recombinant human anti-AQP4 IgG-ABs via implanted i.th. catheters. Repetitive application of patient NMO IgG fractions and of recombinant human anti-AQP4 ABs induced signs of spinal cord disease. Magnetic resonance imaging (MRI) revealed longitudinal spinal cord lesions at the site of application of anti-AQP4 IgG. Somatosensory evoked potential amplitudes were reduced in symptomatic animals corroborating the observed functional impairment. Spinal cord histology showed specific IgG deposition in the grey and white matter in the affected areas. We did not find inflammatory cell infiltration nor activation of complement in spinal cord areas of immunoglobulin deposition. Moreover, destructive lesions showing axon or myelin damage and loss of astrocytes and oligodendrocytes were all absent. Immunoreactivity to AQP4 and to the excitatory amino acid transporter 2 (EAAT2) was markedly reduced whereas immunoreactivity to the astrocytic marker glial fibrillary acid protein (GFAP) was preserved. The expression of the NMDA-receptor NR1 subunit was down-regulated in areas of IgG deposition possibly induced by sustained glutamatergic overexcitation. Disease signs and histopathology were reversible within weeks after stopping injections. We conclude that in vivo application of ABs directed at AQP 4 can induce a reversible spinal cord disease in recipient rats by inducing distinct histopathological abnormalities. These findings may be the experimental correlate of “penumbra-like” lesions recently reported in NMO patients adjacent to effector-mediated tissue damage. PMID:25542977

The intrinsic pathogenic role of autoantibodies to aquaporin 4 mediating spinal cord disease in a rat passive-transfer model.

PubMed

Geis, Christian; Ritter, Christian; Ruschil, Christoph; Weishaupt, Andreas; Grünewald, Benedikt; Stoll, Guido; Holmoy, Trygve; Misu, Tatsuro; Fujihara, Kazuo; Hemmer, Bernhard; Stadelmann, Christine; Bennett, Jeffrey L; Sommer, Claudia; Toyka, Klaus V

2015-03-01

Neuromyelitis optica (NMO) is causally linked to autoantibodies (ABs) against aquaporin 4 (AQP4). Here, we focused on the pathogenic effects exclusively mediated by human ABs to AQP4 in vivo. We performed cell-free intrathecal (i.th.) passive transfer experiments in Lewis rats using purified patient NMO immunoglobulin G (IgG) and various recombinant human anti-AQP4 IgG-ABs via implanted i.th. catheters. Repetitive application of patient NMO IgG fractions and of recombinant human anti-AQP4 ABs induced signs of spinal cord disease. Magnetic resonance imaging (MRI) revealed longitudinal spinal cord lesions at the site of application of anti-AQP4 IgG. Somatosensory evoked potential amplitudes were reduced in symptomatic animals corroborating the observed functional impairment. Spinal cord histology showed specific IgG deposition in the grey and white matter in the affected areas. We did not find inflammatory cell infiltration nor activation of complement in spinal cord areas of immunoglobulin deposition. Moreover, destructive lesions showing axon or myelin damage and loss of astrocytes and oligodendrocytes were all absent. Immunoreactivity to AQP4 and to the excitatory amino acid transporter 2 (EAAT2) was markedly reduced whereas immunoreactivity to the astrocytic marker glial fibrillary acid protein (GFAP) was preserved. The expression of the NMDA-receptor NR1 subunit was downregulated in areas of IgG deposition possibly induced by sustained glutamatergic overexcitation. Disease signs and histopathology were reversible within weeks after stopping injections. We conclude that in vivo application of ABs directed at AQP 4 can induce a reversible spinal cord disease in recipient rats by inducing distinct histopathological abnormalities. These findings may be the experimental correlate of "penumbra-like" lesions recently reported in NMO patients adjacent to effector-mediated tissue damage. Copyright © 2014 Elsevier Inc. All rights reserved.

Immunoglobulins G from Sera of Amyotrophic Lateral Sclerosis Patients Induce Oxidative Stress and Upregulation of Antioxidative System in BV-2 Microglial Cell Line

PubMed Central

Milošević, Milena; Milićević, Katarina; Božić, Iva; Lavrnja, Irena; Stevanović, Ivana; Bijelić, Dunja; Dubaić, Marija; Živković, Irena; Stević, Zorica; Giniatullin, Rashid; Andjus, Pavle

2017-01-01

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder with a very fast progression, no diagnostic tool for the presymptomatic phase, and still no effective treatment of the disease. Although ALS affects motor neurons, the overall pathophysiological condition points out to the non-cell autonomous mechanisms, where astrocytes and microglia play crucial roles in the disease progression. We have already shown that IgG from sera of ALS patients (ALS IgG) induce calcium transients and an increase in the mobility of acidic vesicles in cultured rat astrocytes. Having in mind the role of microglia in neurodegeneration, and a well-documented fact that oxidative stress is one of the many components contributing to the disease, we decided to examine the effect of ALS IgG on activation, oxidative stress and antioxidative system of BV-2 microglia, and to evaluate their acute effect on cytosolic peroxide, pH, and on reactive oxygen species (ROS) generation. All tested ALS IgGs (compared to control IgG) induced oxidative stress (rise in nitric oxide and the index of lipid peroxidation) followed by release of TNF-α and higher antioxidative defense (elevation of Mn- and CuZn-superoxide dismutase, catalase, and glutathione reductase with a decrease of glutathione peroxidase and glutathione) after 24 h treatment. Both ALS IgG and control IgG showed same localization on the membrane of BV-2 cells following 24 h treatment. Cytosolic peroxide and pH alteration were evaluated with fluorescent probes HyPer and SypHer, respectively, having in mind that HyPer also reacts to pH changes. Out of 11 tested IgGs from ALS patients, 4 induced slow exponential rise of HyPer signal, with maximal normalized fluorescence in the range 0.2–0.5, also inducing similar increase of SypHer intensity, but of a lower amplitude. None of the control IgGs induced changes with neither of the indicators. Acute ROS generation was detected in one out of three tested ALS samples with carboxy-H2DCFDA. The observed phenomena demonstrate the potential role of inflammatory humoral factors, IgGs, as potential triggers of the activation in microglia, known to occur in later stages of ALS. Therefore, revealing the ALS IgG signaling cascade in microglial cells could offer a valuable molecular biomarker and/or a potential therapeutic target. PMID:29218049

Ghrelin-reactive immunoglobulins and anxiety, depression and stress-induced cortisol response in adolescents. The TRAILS study.

PubMed

François, Marie; Schaefer, Johanna M; Bole-Feysot, Christine; Déchelotte, Pierre; Verhulst, Frank C; Fetissov, Sergueï O

2015-06-03

Ghrelin, a hunger hormone, has been implicated in the regulation of stress-response, anxiety and depression. Ghrelin-reactive immunoglobulins (Ig) were recently identified in healthy and obese humans showing abilities to increase ghrelin's stability and orexigenic effects. Here we studied if ghrelin-reactive Ig are associated with anxiety and depression and with the stress-induced cortisol response in a general population of adolescents. Furthermore, to test the possible infectious origin of ghrelin-reactive Ig, their levels were compared with serum IgG against common viruses. We measured ghrelin-reactive IgM, IgG and IgA in serum samples of 1199 adolescents from the Dutch TRAILS study and tested their associations with 1) anxiety and depression symptoms assessed with the Youth Self-Report, 2) stress-induced salivary cortisol levels and 3) IgG against human herpesvirus 1, 2, 4 and 6 and Influenza A and B viruses. Ghrelin-reactive IgM and IgG correlated positively with levels of antibodies against Influenza A virus. Ghrelin-reactive IgM correlated negatively with antibodies against Influenza B virus. Ghrelin-reactive IgM correlated positively with anxiety scores in girls and ghrelin-reactive IgG correlated with stress-induced cortisol secretion, but these associations were weak and not significant after correction for multiple testing. These data indicate that production of ghrelin-reactive autoantibodies could be influenced by viral infections. Serum levels of ghrelin-reactive autoantibodies probably do not play a role in regulating anxiety, depression and the stress-response in adolescents from the general population. Copyright © 2015 Elsevier Inc. All rights reserved.

Detection of cytomegalovirus, human parvovirus B19, and herpes simplex virus-1/2 in women with first-trimester spontaneous abortions.

PubMed

Zhou, Ya; Bian, Guohui; Zhou, Qiongxiu; Gao, Zhan; Liao, Pu; Liu, Yu; He, Miao

2015-10-01

The relationship between viral infections and first-trimester spontaneous abortions is not well-understood. The study aim was to investigate the prevalence of cytomegalovirus (CMV), human parvovirus B19 (B19V), and herpes simplex virus-1/2 (HSV-1/2) infection by molecular and serological techniques in women experiencing spontaneous miscarriage in the first trimester of pregnancy. Plasma samples were examined for CMV, B19V, and HSV-1/2 DNA using real-time quantitative polymerase chain reaction (Real-time qPCR), and for specific IgG antibodies against B19V, CMV, and HSV-1/2 using serological assays. The abortion group consisted of women (n = 1,716) with a history of two or more first-trimester spontaneous abortions. Women younger than 30 years possess higher portion to experience spontaneous abortion. No specimens were positive for B19V or CMV DNA. Seven out of the 1,716 specimens were positive for HSV-1/2 DNA. By serology, 47.24% of patients were positive for B19V IgG, 39.66% for HSV IgG, 79.31% for CMV IgG, and 9.31% for B19V IgM. The high rate of positivity for CMV IgG suggests that the majority of women with first-trimester spontaneous abortions are not susceptible to primary CMV infection. The lack of virus DNA in the majority of cases indicates that B19V, CMV, and HSV-1/2 infection is not commonly associated with first-trimester spontaneous abortion. © 2015 Wiley Periodicals, Inc.

Self-oriented nanoparticles for site-selective immunoglobulin G recognition via epitope imprinting approach.

PubMed

Çorman, Mehmet Emin; Armutcu, Canan; Uzun, Lokman; Say, Rıdvan; Denizli, Adil

2014-11-01

Molecular imprinting is a polymerization technique that provides synthetic analogs for template molecules. Molecularly imprinted polymers (MIPs) have gained much attention due to their unique properties such as selectivity and specificity for target molecules. In this study, we focused on the development of polymeric materials with molecular recognition ability, so molecular imprinting was combined with miniemulsion polymerization to synthesize self-orienting nanoparticles through the use of an epitope imprinting approach. Thus, L-lysine imprinted nanoparticles (LMIP) were synthesized via miniemulsion polymerization technique. Immunoglobulin G (IgG) was then bound to the cavities that specifically formed for L-lysine molecules that are typically found at the C-terminus of the Fc region of antibody molecules. The resulting nanoparticles makes it possible to minimize the nonspecific interaction between monomer and template molecules. In addition, the orientation of the entire IgG molecule was controlled, and random imprinting of the IgG was prevented. The optimum conditions were determined for IgG recognition using the imprinted nanoparticles. The selectivity of the nanoparticles against IgG molecules was also evaluated using albumin and hemoglobin as competitor molecules. In order to show the self-orientation capability of imprinted nanoparticles, human serum albumin (HSA) adsorption onto both the plain nanoparticles and immobilized nanoparticles by anti-human serum albumin antibody (anti-HSA antibody) was also carried out. Due to anti-HSA antibody immobilization on the imprinted nanoparticles, the adsorption capability of nanoparticles against HSA molecules vigorously enhanced. It is proved that the oriented immobilization of antibodies was appropriately succeeded. Copyright © 2014 Elsevier B.V. All rights reserved.

Formation of multimeric antibodies for self-delivery of active monomers.

PubMed

Dekel, Yaron; Machluf, Yossy; Gefen, Tal; Eidelshtein, Gennady; Kotlyar, Alexander; Bram, Yaron; Shahar, Ehud; Reslane, Farah; Aizenshtein, Elina; Pitcovski, Jacob

2017-11-01

Proteins and peptides have been used as drugs for almost a century. Technological advances in the past 30 years have enabled the production of pure, stable proteins in vast amounts. In contrast, administration of proteins based on their native active conformation (and thus necessitating the use of subcutaneous injections) has remained solely unchanged. The therapeutic anti-HER2 humanized monoclonal immunoglobulin (IgG) Trastuzumab (Herceptin) is a first line of the treatment for breast cancer. Chicken IgY is a commercially important polyclonal antibody (Ab). These Abs were examined for their ability to self-assemble and form ordered aggregates, by several biophysical methods. Atomic force microscopy analyses revealed the formation of multimeric nanostructures. The biological activity of multimeric IgG or IgY particles was retained and restored, in a dilution/time-dependent manner. IgG activity was confirmed by a binding assay using HER2 + human breast cancer cell line, SKBR3, while IgY activity was confirmed by ELISA assay using the VP2 antigen. Competition assay with native Herceptin antibodies demonstrated that the binding availability of the multimer formulation remained unaffected. Under long incubation periods, IgG multimers retained five times more activity than native IgG. In conclusion, the multimeric antibody formulations can serve as a storage depositories and sustained-release particles. These two important characteristics make this formulation promising for future novel administration protocols and altogether bring to light a different conceptual approach for the future use of therapeutic proteins as self-delivery entities rather than conjugated/encapsulated to other bio-compounds.

Serological profiling of the EBV immune response in Chronic Fatigue Syndrome using a peptide microarray.

PubMed

Loebel, Madlen; Eckey, Maren; Sotzny, Franziska; Hahn, Elisabeth; Bauer, Sandra; Grabowski, Patricia; Zerweck, Johannes; Holenya, Pavlo; Hanitsch, Leif G; Wittke, Kirsten; Borchmann, Peter; Rüffer, Jens-Ulrich; Hiepe, Falk; Ruprecht, Klemens; Behrends, Uta; Meindl, Carola; Volk, Hans-Dieter; Reimer, Ulf; Scheibenbogen, Carmen

2017-01-01

Epstein-Barr-Virus (EBV) plays an important role as trigger or cofactor for various autoimmune diseases. In a subset of patients with Chronic Fatigue Syndrome (CFS) disease starts with infectious mononucleosis as late primary EBV-infection, whereby altered levels of EBV-specific antibodies can be observed in another subset of patients. We performed a comprehensive mapping of the IgG response against EBV comparing 50 healthy controls with 92 CFS patients using a microarray platform. Patients with multiple sclerosis (MS), systemic lupus erythematosus (SLE) and cancer-related fatigue served as controls. 3054 overlapping peptides were synthesised as 15-mers from 14 different EBV proteins. Array data was validated by ELISA for selected peptides. Prevalence of EBV serotypes was determined by qPCR from throat washing samples. EBV type 1 infections were found in patients and controls. EBV seroarray profiles between healthy controls and CFS were less divergent than that observed for MS or SLE. We found significantly enhanced IgG responses to several EBNA-6 peptides containing a repeat sequence in CFS patients compared to controls. EBNA-6 peptide IgG responses correlated well with EBNA-6 protein responses. The EBNA-6 repeat region showed sequence homologies to various human proteins. Patients with CFS had a quite similar EBV IgG antibody response pattern as healthy controls. Enhanced IgG reactivity against an EBNA-6 repeat sequence and against EBNA-6 protein is found in CFS patients. Homologous sequences of various human proteins with this EBNA-6 repeat sequence might be potential targets for antigenic mimicry.

Detection of Antibodies against Paracoccidioides brasiliensis Melanin in In Vitro and In Vivo Studies during Infection ▿

PubMed Central

Urán, Martha E.; Nosanchuk, Joshua D.; Restrepo, Angela; Hamilton, Andrew J.; Gómez, Beatriz L.; Cano, Luz E.

2011-01-01

Several cell wall constituents, including melanins or melanin-like compounds, have been implicated in the pathogenesis of a wide variety of microbial diseases caused by diverse species of pathogenic bacteria, fungi, and helminthes. Among these microorganisms, the dimorphic fungal pathogen Paracoccidioides brasiliensis produces melanin in its conidial and yeast forms. In the present study, melanin particles from P. brasiliensis were injected into BALB/c mice in order to produce monoclonal antibodies (MAbs). We identified five immunoglobulin G1 (IgG1) κ-chain and four IgM melanin-binding MAbs. The five IgG1 κ-chain isotypes are the first melanin-binding IgG MAbs ever reported. The nine MAbs labeled P. brasiliensis conidia and yeast cells both in vitro and in pulmonary tissues. The MAbs cross-reacted with melanin-like purified particles from other fungi and also with commercial melanins, such as synthetic and Sepia officinalis melanin. Melanization during paracoccidioidomycosis (PCM) was also further supported by the detection of IgG antibodies reactive to melanin from P. brasiliensis conidia and yeast in sera and bronchoalveolar lavage fluids from P. brasiliensis-infected mice, as well as in sera from human patients with PCM. Serum specimens from patients with other mycoses were also tested for melanin-binding antibodies by enzyme-linked immunosorbent assay, and cross-reactivities were detected for melanin particles from different fungal sources. These results suggest that melanin from P. brasiliensis is an immunologically active fungal structure that activates a strong IgG humoral response in humans and mice. PMID:21813659

Detection of antibodies against Paracoccidioides brasiliensis melanin in in vitro and in vivo studies during infection.

PubMed

Urán, Martha E; Nosanchuk, Joshua D; Restrepo, Angela; Hamilton, Andrew J; Gómez, Beatriz L; Cano, Luz E

2011-10-01

Several cell wall constituents, including melanins or melanin-like compounds, have been implicated in the pathogenesis of a wide variety of microbial diseases caused by diverse species of pathogenic bacteria, fungi, and helminthes. Among these microorganisms, the dimorphic fungal pathogen Paracoccidioides brasiliensis produces melanin in its conidial and yeast forms. In the present study, melanin particles from P. brasiliensis were injected into BALB/c mice in order to produce monoclonal antibodies (MAbs). We identified five immunoglobulin G1 (IgG1) κ-chain and four IgM melanin-binding MAbs. The five IgG1 κ-chain isotypes are the first melanin-binding IgG MAbs ever reported. The nine MAbs labeled P. brasiliensis conidia and yeast cells both in vitro and in pulmonary tissues. The MAbs cross-reacted with melanin-like purified particles from other fungi and also with commercial melanins, such as synthetic and Sepia officinalis melanin. Melanization during paracoccidioidomycosis (PCM) was also further supported by the detection of IgG antibodies reactive to melanin from P. brasiliensis conidia and yeast in sera and bronchoalveolar lavage fluids from P. brasiliensis-infected mice, as well as in sera from human patients with PCM. Serum specimens from patients with other mycoses were also tested for melanin-binding antibodies by enzyme-linked immunosorbent assay, and cross-reactivities were detected for melanin particles from different fungal sources. These results suggest that melanin from P. brasiliensis is an immunologically active fungal structure that activates a strong IgG humoral response in humans and mice.

Human IgG1 Responses to Surface Localised Schistosoma mansoni Ly6 Family Members Drop following Praziquantel Treatment.

PubMed

Chalmers, Iain W; Fitzsimmons, Colin M; Brown, Martha; Pierrot, Christine; Jones, Frances M; Wawrzyniak, Jakub M; Fernandez-Fuentes, Narcis; Tukahebwa, Edridah M; Dunne, David W; Khalife, Jamal; Hoffmann, Karl F

2015-01-01

The heptalaminate-covered, syncytial tegument is an important anatomical adaptation that enables schistosome parasites to maintain long-term, intravascular residence in definitive hosts. Investigation of the proteins present in this surface layer and the immune responses elicited by them during infection is crucial to our understanding of host/parasite interactions. Recent studies have revealed a number of novel tegumental surface proteins including three (SmCD59a, SmCD59b and Sm29) containing uPAR/Ly6 domains (renamed SmLy6A SmLy6B and SmLy6D in this study). While vaccination with SmLy6A (SmCD59a) and SmLy6D (Sm29) induces protective immunity in experimental models, human immunoglobulin responses to representative SmLy6 family members have yet to be thoroughly explored. Using a PSI-BLAST-based search, we present a comprehensive reanalysis of the Schistosoma mansoni Ly6 family (SmLy6A-K). Our examination extends the number of members to eleven (including three novel proteins) and provides strong evidence that the previously identified vaccine candidate Sm29 (renamed SmLy6D) is a unique double uPAR/Ly6 domain-containing representative. Presence of canonical cysteine residues, signal peptides and GPI-anchor sites strongly suggest that all SmLy6 proteins are cell surface-bound. To provide evidence that SmLy6 members are immunogenic in human populations, we report IgG1 (as well as IgG4 and IgE) responses against two surface-bound representatives (SmLy6A and SmLy6B) within a cohort of S. mansoni-infected Ugandan males before and after praziquantel treatment. While pre-treatment IgG1 prevalence for SmLy6A and SmLy6B differs amongst the studied population (7.4% and 25.3% of the cohort, respectively), these values are both higher than IgG1 prevalence (2.7%) for a sub-surface tegumental antigen, SmTAL1. Further, post-treatment IgG1 levels against surface-associated SmLy6A and SmLy6B significantly drop (p = 0.020 and p < 0.001, respectively) when compared to rising IgG1 levels against sub-surface SmTAL1. Collectively, these results expand the number of SmLy6 proteins found within S. mansoni and specifically demonstrate that surface-associated SmLy6A and SmLy6B elicit immunological responses during infection in endemic communities.

Human parvovirus B19 antibodies induce altered membrane protein expression and apoptosis of BeWo trophoblasts.

PubMed

Tzang, Bor-Show; Chiang, Szu-Yi; Chan, Hsu-Chin; Liu, Chung-Hsien; Hsu, Tsai-Ching

2016-11-01

Human parvovirus B19 (B19) is harmful during pregnancy since it can be vertically transmitted to the developing fetus. In addition, the anti‑B19 antibodies induced by B19 infection are believed to have a cytopathic role in B19 transmission; however, knowledge regarding the effects of anti‑B19 antibodies during pregnancy is limited. To investigate the possible roles of anti‑B19 antibodies during pregnancy, the present study examined the effects of anti‑B19‑VP1 unique region (VP1u), anti‑B19‑VP2 and anti‑B19‑nonstructural protein 1 (NS1) immunoglobulin G (IgG) antibodies on BeWo trophoblasts. Briefly, BeWo trophoblasts were incubated with purified IgG against B19‑VP1u, B19‑VP2 and B19‑NS1. Subsequently, the expression of surface proteins and apoptotic molecules were assessed in BeWo trophoblasts using flow cytometry, ELISA and western blotting. The expression levels of human leukocyte antigen (HLA)‑G were significantly increased on BeWo trophoblasts treated with rabbit anti‑B19‑VP1u IgG, and were unchanged in those treated with rabbit anti‑B19‑NS1 and anti‑B19‑VP2 IgG, as compared with the control group. Furthermore, the expression levels of globoside (P blood group antigen) and cluster of differentiation (CD)29 (β1 integrin) were significantly increased in BeWo trophoblasts treated with rabbit anti‑B19‑NS1 and anti‑B19‑VP2 IgG, whereas only CD29 was also significantly increased in cells treated with anti‑B19‑VP1u IgG. In addition, the number of cells at sub‑G1 phase; caspase‑3 activity; and the expression of intrinsic and extrinsic apoptotic molecules, including Fas‑associated death domain protein, activated caspase‑8, activated caspase‑3, B‑cell lymphoma 2‑associated X protein, cytochrome c, apoptotic peptidase activating factor 1 and activated caspase‑9, were significantly increased in BeWo trophoblasts treated with anti‑B19‑VP1u and anti‑B19‑NS1 IgG. In conclusion, the present study demonstrated that antibodies against B19 may have a crucial role in pathological processes during pregnancy. These findings may help to elucidate the mechanisms underlying transmission of the B19 virus during pregnancy.

Sarcoidosis mimicking toxoplasmosis with severe hypercalcaemia and normal 1,25-dihydroxy vitamin D.

PubMed

Levy, Y; Hayek, T; Finkelstein, R

1996-09-01

We report a case of a female patient with sarcoidosis who presented with a generalized lymphadenopathy and a strong IgG serological test of toxoplasmosis. Progressive lymphadenopathy with a rising plasma calcium (up to 15 mg dL-1) with a normal plasma 1,25-dihydroxy vitamin D concentration occurred later. Corticosteroid therapy resulted in prompt clinical and biochemical responses with normalization of plasma calcium and a significant reduction in 1,25-dihydroxy vitamin D concentration. This is an exceptional presentation of sarcoidosis with severe hypercalcaemia and normal vitamin D metabolites.

[Investigation of dengue virus and yellow fever virus seropositivities in blood donors from Central/Northern Anatolia, Turkey].

PubMed

Ergünay, Koray; Saygan, Mehmet B; Aydoğan, Sibel; Litzba, Nadine; Niedrig, Matthias; Pınar, Ahmet; Us, Dürdal

2010-07-01

Dengue virus (DENV) and yellow fever virus (YFV) are two of the globally prevalent vector-borne flaviviruses. Data on these viruses from Turkey is limited to a single study originating from the western, Aegean region of Turkey, where evidence for DENV exposure had been confirmed in residents and presence of hemagglutination inhibiting antibodies against YFV had been revealed. The aim of this study was to investigate the rates of seropositivity of DENV and YFV in blood donors from Central/Northern Anatolia, Turkey, for the demonstration of possible human exposure. Serum samples were collected by the Turkish Red Crescent Middle Anatolia Regional Blood Center from donation sites at Ankara, Konya, Eskişehir and Zonguldak provinces and included in the study after informed consent. Ankara is the capital and second most-populated city in Turkey. All samples were previously evaluated for West Nile and tick-borne encephalitis virus antibodies and found to be negative. A total of 2435 and 1502 sera have been evaluated for IgG antibodies against DENV and YFV, respectively. Commercial enzymelinked immunosorbent assays (ELISAs) and indirect immunofluorescence tests (IIFTs) were applied (Euroimmun, Germany) for DENV/YFV IgG surveillance. DENV IgG reactive sera were further evaluated for IgM by ELISA and a commercial mosaic IIFT to determine DENV subtypes. IgM positive samples were also analyzed by a commercial NS1 antigen detection assay (Bio-Rad Laboratories, France). YFV IgG reactive samples were evaluated by IIFT for IgM and via mosaic IIFT and antibody specificity were confirmed by plaque reduction neutralization test (PRNT). Anti-DENV IgGs were demonstrated in repeated assays in 0.9% (21/2435) of the sera. In two samples with borderline IgG results, presence of DENV IgM was detected, one of which was also borderline positive for DENV NS1 antigen. In 14.3% (3/21) of the IgG reactive sera, mosaic IIFT was evaluated as positive and displayed prominent reactivity for DENV-2 in all samples. From five donors with DENV reactivity, new samples were obtained after at least six months which revealed the continuing presence of DENV IgG activity in four. One sample which was initially positive for IgM, borderline for NS1 antigen and borderline for IgG was observed to be positive for IgG and negative for IgM in redonation. IIFT results in three redonation samples also indicated reactivity for DENV-1 and DENV-2 subtypes. Anti-YFV IgGs were detected in 0.6% (9/1502) of the sera. YFV IgM could not be demonstrated in any of the IgG reactive samples and PRNT was evaluated as negative. In conclusion, evidence for DENV exposure, presumably to DENV-2, was identified in residents from Central Anatolian provinces of Ankara and Konya for the first time, however, seroreactivity detected against YFV could not be confirmed by PRNT. These findings indicated that DENV or an antigenically-similar flavivirus was probably present in the study region and sporadic human exposure might have occurred.

Understanding Human-Plasmodium falciparum Immune Interactions Uncovers the Immunological Role of Worms

PubMed Central

Roussilhon, Christian; Brasseur, Philippe; Agnamey, Patrice; Pérignon, Jean-Louis; Druilhe, Pierre

2010-01-01

Background Former studies have pointed to a monocyte-dependant effect of antibodies in protection against malaria and thereby to cytophilic antibodies IgG1 and IgG3, which trigger monocyte receptors. Field investigations have further documented that a switch from non-cytophilic to cytophilic classes of antimalarial antibodies was associated with protection. The hypothesis that the non-cytophilic isotype imbalance could be related to concomittant helminthic infections was supported by several interventions and case-control studies. Methods and Findings We investigated here the hypothesis that the delayed acquisition of immunity to malaria could be related to a worm-induced Th2 drive on antimalarial immune responses. IgG1 to IgG4 responses against 6 different parasite-derived antigens were analyzed in sera from 203 Senegalese children, half carrying intestinal worms, presenting 421 clinical malaria attacks over 51 months. Results show a significant correlation between the occurrence of malaria attacks, worm carriage (particularly that of hookworms) and a decrease in cytophilic IgG1 and IgG3 responses and an increase in non-cytophilic IgG4 response to the merozoite stage protein 3 (MSP3) vaccine candidate. Conclusion The results confirm the association with protection of anti-MSP3 cytophilic responses, confirm in one additional setting that worms increase malaria morbidity and show a Th2 worm-driven pattern of anti-malarial immune responses. They document why large anthelminthic mass treatments may be worth being assessed as malaria control policies. PMID:20174576

Detection of specific antibody responses to vaccination in variable flying foxes (Pteropus hypomelanus).

PubMed

Wellehan, James F X; Green, Linda G; Duke, Diane G; Bootorabi, Shadi; Heard, Darryl J; Klein, Paul A; Jacobson, Elliott R

2009-09-01

Megachiropteran bats are biologically important both as endangered species and reservoirs for emerging human pathogens. Reliable detection of antibodies to specific pathogens in bats is thus epidemiologically critical. Eight variable flying foxes (Pteropus hypomelanus) were immunized with 2,4-dinitrophenylated bovine serum albumin (DNP-BSA). Each bat received monthly inoculations for 2 months. Affinity-purified IgG was used for production of polyclonal and monoclonal anti-variable flying fox IgG antibodies. ELISA and western blot analysis were used to monitor immune responses and for assessment of polyclonal and monoclonal antibody species cross-reactivity. Protein G, polyclonal antibodies, and monoclonal antibodies detected specific anti-DNP antibody responses in immunized variable flying foxes, with protein G being the most sensitive, followed by monoclonal antibodies and then polyclonal antibodies. While the polyclonal antibody was found to cross-react well against IgG of all bat species tested, some non-specific background was observed. The monoclonal antibody was found to cross-react well against IgG of six other species in the genus Pteropus and to cross-react less strongly against IgG from Eidolon helvum or Phyllostomus hastatus. Protein G distinguished best between vaccinated and unvaccinated bats, and these results validate the use of protein G for detection of bat IgG. Monoclonal antibodies developed in this study recognized immunoglobulins from other members of the genus Pteropus well, and may be useful in applications where specific detection of Pteropus IgG is needed.

Impact of age and vaccination history on long-term serological responses after symptomatic B. pertussis infection, a high dimensional data analysis

PubMed Central

van Twillert, Inonge; Bonačić Marinović, Axel A.; Kuipers, Betsy; van Gaans-van den Brink, Jacqueline A. M.; Sanders, Elisabeth A. M.; van Els, Cécile A. C. M.

2017-01-01

Capturing the complexity and waning patterns of co-occurring immunoglobulin (Ig) responses after clinical B. pertussis infection may help understand how the human host gradually loses protection against whooping cough. We applied bi-exponential modelling to characterise and compare B. pertussis specific serological dynamics in a comprehensive database of IgG, IgG subclass and IgA responses to Ptx, FHA, Prn, Fim2/3 and OMV antigens of (ex-) symptomatic pertussis cases across all age groups. The decay model revealed that antigen type and age group were major factors determining differences in levels and kinetics of Ig (sub) classes. IgG-Ptx waned fastest in all age groups, while IgA to Ptx, FHA, Prn and Fim2/3 decreased fast in the younger but remained high in older (ex-) cases, indicating an age-effect. While IgG1 was the main IgG subclass in response to most antigens, IgG2 and IgG3 dominated the anti-OMV response. Moreover, vaccination history plays an important role in post-infection Ig responses, demonstrated by low responsiveness to Fim2/3 in unvaccinated elderly and by elevated IgG4 responses to multiple antigens only in children primed with acellular pertussis vaccine (aP). This work highlights the complexity of the immune response to this re-emerging pathogen and factors determining its Ig quantity and quality. PMID:28091579

Kinetics of N-Glycan Release from Human Immunoglobulin G (IgG) by PNGase F: All Glycans Are Not Created Equal.

PubMed

Huang, Yining; Orlando, Ron

2017-12-01

The biologic activity of IgG molecules is modulated by its crystallizable fragment N-glycosylation, and thus, the analysis of IgG glycosylation is critical. A standard approach to analyze glycosylation of IgGs involves the release of the N-glycans by the enzyme peptide N-glycosidase F, which cleaves the linkage between the asparagine residue and innermost N-acetylglucosamine (GlcNAc) of all N-glycans except those containing a 3-linked fucose attached to the reducing terminal GlcNAc residue. The importance of obtaining complete glycan release for accurate quantitation led us to investigate the kinetics of this de-glycosylation reaction for IgG glycopeptides and to determine the effect of glycan structure and amino acid sequence on the rate of glycan release from glycopeptides of IgGs. This study revealed that the slight differences in amino acid sequences did not lead to a statistically different deglycosylation rate. However, statistically significant differences in the deglycosylation rate constants were observed between glycopeptides differing only in glycan structure ( i.e. , nonfucosylated, fucosylated, bisecting-GlcNAc, sialylated, etc .). For example, a single sialic acid residue was found to decrease the rate by a factor of 3. Similar reductions in rate were associated with the presence of a bisecting-GlcNAc. We predict the differences in release kinetics can lead to significant quantitative variations of the glycosylation study of IgGs.

Evaluation of clinical and serological findings for diagnosis of cutaneous anthrax infection after an outbreak.

PubMed

Gulseren, Duygu; Süzük-Yıldız, Serap; Çelebi, Bekir; Kılıç, Selçuk

2017-09-01

Anthrax, caused by the bacterium Bacillus anthracis, is one of the oldest documented infectious diseases in both livestock and humans. We aimed to evaluate clinical findings and risk factors of patients with cutaneous anthrax infection and report anti-lethal factor (LF) IgG and anti-protective antigen (PA) IgG titers in the serologic diagnosis of disease. In this study, serum samples of 18 cutaneous anthrax patients were collected and anti-LF IgG and anti-PA IgG titers were measured by enzyme-linked immunosorbent assay (ELISA). Twelve (67%) males and 6 (33%) females, with a mean age of 36.06 ± 16.58 years were included in the study. Risk factors identified in the patient population studied were slaughtering (28%), flaying (56%), chopping meat (67%), burying diseased animal corpses (17%) and milking (6%) livestock. Black eschar formation (94%), pruritus (78%) and painful lymphadenopathy (61%) were first three common clinical signs and symptoms, respectively. Fourteen (78%) patients produced a positive IgG response against PA, 11 (61%) patients produced against LF. Three (17%) patients had no response to either antigen. A detailed history of contact with sick animals or animal products along with clinical findings should be taken at the first step for the diagnosis of cutaneous anthrax infection. Serologic detection of anti-LF IgG and anti-PA IgG with ELISA may be useful auxillary method for establishing the diagnosis.

Antibody classes & subclasses induced by mucosal immunization of mice with Streptococcus pyogenes M6 protein & oligodeoxynucleotides containing CpG motifs.

PubMed

Teloni, R; von Hunolstein, C; Mariotti, S; Donati, S; Orefici, G; Nisini, R

2004-05-01

Type-specific antibodies against M protein are critical for human protection as they enhance phagocytosis and are protective. An ideal vaccine for the protection against Streptococcus pyogenes would warrant mucosal immunity, but mucosally administered M-protein has been shown to be poorly immunogenic in animals. We used a recombinant M type 6 protein to immunize mice in the presence of synthetic oligodeoxynucleotides containing CpG motifs (immunostimulatory sequences: ISS) or cholera toxin (CT) to explore its possible usage in a mucosal vaccine. Mice were immunized by intranasal (in) or intradermal (id) administration with four doses at weekly intervals of M6-protein (10 microg/mouse) with or without adjuvant (ISS, 10 microg/mouse or CT, 0,5 microg/mouse). M6 specific antibodies were measured by enzyme linked immunosorbent assay using class and subclass specific monoclonal antibodies. The use of ISS induced an impressive anti M-protein serum IgG response but when id administered was not detectable in the absence of adjuvant. When used in, M-protein in the presence of both ISS and CT induced anti M-protein IgA in the bronchoalveolar lavage, as well as specific IgG in the serum. IgG were able to react with serotype M6 strains of S. pyogenes. The level of antibodies obtained by immunizing mice in with M-protein and CT was higher in comparison to M-protein and ISS. The analysis of anti-M protein specific IgG subclasses showed high levels of IgG1, IgG2a and IgG2b, and low levels of IgG3 when ISS were used as adjuvant. Thus, in the presence of ISS, the ratio IgG2a/IgG1 and (IgG2a+IgG3)/IgG1 >1 indicated a type 1-like response obtained both in mucosally or systemically vaccinated mice. Our study offers a reproducible model of anti-M protein vaccination that could be applied to test new antigenic formulations to induce an anti-group A Streptococcus (GAS) vaccination suitable for protection against the different diseases caused by this bacterium.

Human hybrid hybridoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tiebout, R.F.; van Boxtel-Oosterhof, F.; Stricker, E.A.M.

1987-11-15

Hybrid hybridomas are obtained by fusion of two cells, each producing its own antibody. Several authors have reported the construction of murine hybrid hybridomas with the aim to obtain bispecific monoclonal antibodies. The authors have investigated, in a model system, the feasibility of constructing a human hybrid hybridoma. They fused two monoclonal cell lines: an ouabain-sensitive and azaserine/hypoxanthine-resistant Epstein-Barr virus-transformed human cell line that produces an IgG1kappa antibody directed against tetanus toxiod and an azaserine/hypoxanthine-sensitive and ouabain-resistant human-mouse xenohybrid cell line that produces a human IgG1lambda antibody directed against hepatitis-B surface antigen. Hybrid hybridoma cells were selected in culture mediummore » containing azaserine/hypoxanthine and ouabain. The hybrid nature of the secreted antibodies was analyzed by means of two antigen-specific immunoassay. The results show that it is possible, with the combined use of transformation and xenohybridization techniques, to construct human hybrid hybridomas that produce bispecific antibodies. Bispecific antibodies activity was measured by means of two radioimmunoassays.« less

Production and purification of polyclonal antibody against F(ab')2 fragment of human immunoglobulin G

PubMed Central

Nasiri, Hadi; Valedkarimi, Zahra; Aghebati-Maleki, Leili; Abdolalizadeh, Jalal; Kazemi, Tohid; Esparvarinha, Mojghan; Majidi, Jafar

2017-01-01

Antibodies are essential tools of biomedical and biochemical researches. Polyclonal antibodies are produced against different epitopes of antigens. Purified F(ab')2 can be used for animal’s immunization to produce polyclonal antibodies. Human immunoglobulin G (IgG) was purified by ion exchange chromatography method. In all stages verification method of the purified antibodies was sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Purified IgG was digested by pepsin enzyme and F(ab')2 fragment was purified by gel filtration separation method. For production of polyclonal antibody, rabbit was immunized by purified F(ab')2 and antibody production was investigated by enzyme-linked immunosorbent assay. Purified anti-IgG F(ab')2 was conjugated with fluorescein isothiocyanate. Ion exchange chromatography purification yielded 38 mg of human IgG antibody. The results of SDS-PAGE in reduced and non-reduced conditions showed bands with 25-30 kDa molecular weight (MW) and 50-kDa respectively and a distinct band with 150 kDa MW. The results of non-reduced SDS-PAGE for determining the purity of F(ab')2 fragment showed one band in 90 kDa and a band in 150 kDa MW position. Purification by Ion exchange chromatography method resulted about 12 mg rabbit polyclonal antibody. Flow cytometry showed generated polyclonal antibody had an acceptable activity compared to commercial antibody. Taking together, purified IgG F(ab')2 and polyclonal anti-IgG F(ab')2 are useful tools in biomedical and biochemical researches and diagnostic kits. PMID:29326789

Production and purification of polyclonal antibody against F(ab')2 fragment of human immunoglobulin G.

PubMed

Nasiri, Hadi; Valedkarimi, Zahra; Aghebati-Maleki, Leili; Abdolalizadeh, Jalal; Kazemi, Tohid; Esparvarinha, Mojghan; Majidi, Jafar

2017-01-01

Antibodies are essential tools of biomedical and biochemical researches. Polyclonal antibodies are produced against different epitopes of antigens. Purified F(ab') 2 can be used for animal's immunization to produce polyclonal antibodies. Human immunoglobulin G (IgG) was purified by ion exchange chromatography method. In all stages verification method of the purified antibodies was sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Purified IgG was digested by pepsin enzyme and F(ab') 2 fragment was purified by gel filtration separation method. For production of polyclonal antibody, rabbit was immunized by purified F(ab') 2 and antibody production was investigated by enzyme-linked immunosorbent assay. Purified anti-IgG F(ab') 2 was conjugated with fluorescein isothiocyanate. Ion exchange chromatography purification yielded 38 mg of human IgG antibody. The results of SDS-PAGE in reduced and non-reduced conditions showed bands with 25-30 kDa molecular weight (MW) and 50-kDa respectively and a distinct band with 150 kDa MW. The results of non-reduced SDS-PAGE for determining the purity of F(ab') 2 fragment showed one band in 90 kDa and a band in 150 kDa MW position. Purification by Ion exchange chromatography method resulted about 12 mg rabbit polyclonal antibody. Flow cytometry showed generated polyclonal antibody had an acceptable activity compared to commercial antibody. Taking together, purified IgG F(ab') 2 and polyclonal anti-IgG F(ab') 2 are useful tools in biomedical and biochemical researches and diagnostic kits.

Development of a 'mouse and human cross-reactive' affinity-matured exosite inhibitory human antibody specific to TACE (ADAM17) for cancer immunotherapy.

PubMed

Kwok, Hang Fai; Botkjaer, Kenneth A; Tape, Christopher J; Huang, Yanchao; McCafferty, John; Murphy, Gillian

2014-06-01

We previously showed that a human anti-TACE antibody, D1(A12), is a potent inhibitor of TNF-α converting enzyme (TACE) ectodomain proteolysis and has pharmacokinetic properties suitable for studies of the inhibition of TACE-dependent growth factor shedding in relation to possible therapeutic applications. However, the lack of murine TACE immunoreactivity limits pre-clinical in vivo studies to human xenograft models which are poor analogies to in situ pathology and are not considered clinically predictive. Here, to overcome these limitations, we set out to develop a 'mouse and human cross-reactive' specific anti-TACE antibody. We first re-investigated the originally selected anti-TACE ectodomain phage-display clones, and isolated a lead 'mouse-human cross-reactive' anti-TACE scFv, clone A9. We reformatted scFv-A9 into an IgG2 framework for comprehensive biochemical and cellular characterization and further demonstrated that A9 is an exosite TACE inhibitor. However, surface plasmon resonance analysis and quenched-fluorescent (QF) peptide assay indicated that IgG reformatting of A9 caused low binding affinity and an 80-fold reduction in TACE ectodomain inhibition, severely limiting its efficacy. To address this, we constructed second generation phage-display randomization libraries focused on the complementarity-determining region 3, and carried out affinity selections shuffling between human and mouse TACE ectodomain as antigen in addition to an off-rate selection to increase the chance of affinity improvement. The bespoke 'three-step' selections enabled a 100-fold affinity enhancement of A9 IgG, and also improved its IC50 in a QF peptide assay to 0.2 nM. In human and mouse cancer cell assays, matured A9 IgG showed significant cell-surface TACE inhibition as a monotherapy or combination therapy with chemotherapeutic agent. Collectively, these data suggest that we successfully developed an exosite inhibitor of TACE with sub-nanomolar affinity, which possesses both murine and human immunoreactive properties that can be used for in vivo application in murine pre-clinical cancer models. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Human non-neutralizing HIV-1 envelope monoclonal antibodies limit the number of founder viruses during SHIV mucosal infection in rhesus macaques

DOE PAGES

Santra, Sampa; Tomaras, Georgia D.; Warrier, Ranjit; ...

2015-08-03

HIV-1 mucosal transmission begins with virus or virus-infected cells moving through mucus across mucosal epithelium to infect CD4⁺ T cells. Although broadly neutralizing antibodies (bnAbs) are the type of HIV-1 antibodies that are most likely protective, they are not induced with current vaccine candidates. In contrast, antibodies that do not neutralize primary HIV-1 strains in the TZM-bl infection assay are readily induced by current vaccine candidates and have also been implicated as secondary correlates of decreased HIV-1 risk in the RV144 vaccine efficacy trial. Here, we have studied the capacity of anti-Env monoclonal antibodies (mAbs) against either the immunodominant regionmore » of gp41 (7B2 IgG1), the first constant region of gp120 (A32 IgG1), or the third variable loop (V3) of gp120 (CH22 IgG1) to modulate in vivo rectal mucosal transmission of a high-dose simian-human immunodeficiency virus (SHIV-BaL) in rhesus macaques. 7B2 IgG1 or A32 IgG1, each containing mutations to enhance Fc function, was administered passively to rhesus macaques but afforded no protection against productive clinical infection while the positive control antibody CH22 IgG1 prevented infection in 4 of 6 animals. Enumeration of transmitted/founder (T/F) viruses revealed that passive infusion of each of the three antibodies significantly reduced the number of T/F genomes. Some antibodies that bind HIV-1 Env but fail to neutralize virus in traditional neutralization assays may limit the number of T/F viruses involved in transmission without leading to enhancement of viral infection. For one of these mAbs, gp41 mAb 7B2, we provide the first co-crystal structure in complex with a common cyclical loop motif demonstrated to be critical for infection by other retroviruses.« less

Human Non-neutralizing HIV-1 Envelope Monoclonal Antibodies Limit the Number of Founder Viruses during SHIV Mucosal Infection in Rhesus Macaques

PubMed Central

Liao, Hua-Xin; Pollara, Justin; Liu, Pinghuang; Alam, S. Munir; Zhang, Ruijun; Cocklin, Sarah L.; Shen, Xiaoying; Duffy, Ryan; Xia, Shi-Mao; Schutte, Robert J.; Pemble IV, Charles W.; Dennison, S. Moses; Li, Hui; Chao, Andrew; Vidnovic, Kora; Evans, Abbey; Klein, Katja; Kumar, Amit; Robinson, James; Landucci, Gary; Forthal, Donald N.; Montefiori, David C.; Kaewkungwal, Jaranit; Nitayaphan, Sorachai; Pitisuttithum, Punnee; Rerks-Ngarm, Supachai; Robb, Merlin L.; Michael, Nelson L.; Kim, Jerome H.; Soderberg, Kelly A.; Giorgi, Elena E.; Blair, Lily; Korber, Bette T.; Moog, Christiane; Shattock, Robin J.; Schmitz, Joern E.; Moody, M. A.; Gao, Feng; Ferrari, Guido; Shaw, George M.; Haynes, Barton F.

2015-01-01

HIV-1 mucosal transmission begins with virus or virus-infected cells moving through mucus across mucosal epithelium to infect CD4+ T cells. Although broadly neutralizing antibodies (bnAbs) are the type of HIV-1 antibodies that are most likely protective, they are not induced with current vaccine candidates. In contrast, antibodies that do not neutralize primary HIV-1 strains in the TZM-bl infection assay are readily induced by current vaccine candidates and have also been implicated as secondary correlates of decreased HIV-1 risk in the RV144 vaccine efficacy trial. Here, we have studied the capacity of anti-Env monoclonal antibodies (mAbs) against either the immunodominant region of gp41 (7B2 IgG1), the first constant region of gp120 (A32 IgG1), or the third variable loop (V3) of gp120 (CH22 IgG1) to modulate in vivo rectal mucosal transmission of a high-dose simian-human immunodeficiency virus (SHIV-BaL) in rhesus macaques. 7B2 IgG1 or A32 IgG1, each containing mutations to enhance Fc function, was administered passively to rhesus macaques but afforded no protection against productive clinical infection while the positive control antibody CH22 IgG1 prevented infection in 4 of 6 animals. Enumeration of transmitted/founder (T/F) viruses revealed that passive infusion of each of the three antibodies significantly reduced the number of T/F genomes. Thus, some antibodies that bind HIV-1 Env but fail to neutralize virus in traditional neutralization assays may limit the number of T/F viruses involved in transmission without leading to enhancement of viral infection. For one of these mAbs, gp41 mAb 7B2, we provide the first co-crystal structure in complex with a common cyclical loop motif demonstrated to be critical for infection by other retroviruses. PMID:26237403

Injection of celiac disease patient sera or immunoglobulins to mice reproduces a condition mimicking early developing celiac disease.

PubMed

Kalliokoski, Suvi; Caja, Sergio; Frias, Rafael; Laurila, Kaija; Koskinen, Outi; Niemelä, Onni; Mäki, Markku; Kaukinen, Katri; Korponay-Szabó, Ilma R; Lindfors, Katri

2015-01-01

Typical features of celiac disease are small-bowel villus atrophy, crypt hyperplasia, and inflammation which develop gradually concomitant with ingestion of gluten. In addition, patients have anti-transglutaminase 2 (TG2) autoantibodies in their serum and tissues. The aim of this study was to establish whether celiac disease can be passively transferred to mice by serum or immunoglobulins. Serum aliquots or purified immunoglobulins (Ig) were intraperitoneally injected into Hsd:Athymic Nude-Foxn1nu mice for 8 or 27 days. As mice do not have proper IgA transport from peritoneum to blood, sera with a high content of IgG class anti-TG2 antibodies from untreated IgA-deficient celiac patients were used. Mouse sera were tested for celiac disease-specific autoantibodies, and several tissues were analyzed for autoantibody deposits targeted to TG2. Morphological assessment was made of the murine small intestinal mucosa. Injection of celiac disease patient sera or total IgG led to a significant delay in weight gain and mild diarrhea in a subset of mice. The mice injected with celiac patient sera or IgG had significantly decreased villus height crypt depth (Vh/CrD) ratios and celiac disease-specific autoantibody deposits targeted to TG2 in several tissues, including the small intestine. None of these features were observed in control mice. We conclude that administration of IgA-deficient celiac disease patient serum or total IgG induces both deterioration of the intestinal mucosa and clinical features of celiac disease in mice. The experimentally induced condition in the mice injected with patient serum or IgG resembles early developing celiac disease in humans. Celiac disease patient sera or total IgG was injected into athymic mice. A significant delay in weight gain and mild diarrhea was observed. Mice evinced significantly decreased villus height crypt depth ratios. Celiac disease-specific autoantibody deposits were present in several tissues. The condition in mice resembles early stage celiac disease in humans.

Human non-neutralizing HIV-1 envelope monoclonal antibodies limit the number of founder viruses during SHIV mucosal infection in rhesus macaques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Santra, Sampa; Tomaras, Georgia D.; Warrier, Ranjit

HIV-1 mucosal transmission begins with virus or virus-infected cells moving through mucus across mucosal epithelium to infect CD4⁺ T cells. Although broadly neutralizing antibodies (bnAbs) are the type of HIV-1 antibodies that are most likely protective, they are not induced with current vaccine candidates. In contrast, antibodies that do not neutralize primary HIV-1 strains in the TZM-bl infection assay are readily induced by current vaccine candidates and have also been implicated as secondary correlates of decreased HIV-1 risk in the RV144 vaccine efficacy trial. Here, we have studied the capacity of anti-Env monoclonal antibodies (mAbs) against either the immunodominant regionmore » of gp41 (7B2 IgG1), the first constant region of gp120 (A32 IgG1), or the third variable loop (V3) of gp120 (CH22 IgG1) to modulate in vivo rectal mucosal transmission of a high-dose simian-human immunodeficiency virus (SHIV-BaL) in rhesus macaques. 7B2 IgG1 or A32 IgG1, each containing mutations to enhance Fc function, was administered passively to rhesus macaques but afforded no protection against productive clinical infection while the positive control antibody CH22 IgG1 prevented infection in 4 of 6 animals. Enumeration of transmitted/founder (T/F) viruses revealed that passive infusion of each of the three antibodies significantly reduced the number of T/F genomes. Some antibodies that bind HIV-1 Env but fail to neutralize virus in traditional neutralization assays may limit the number of T/F viruses involved in transmission without leading to enhancement of viral infection. For one of these mAbs, gp41 mAb 7B2, we provide the first co-crystal structure in complex with a common cyclical loop motif demonstrated to be critical for infection by other retroviruses.« less

Investigating the Interaction between the Neonatal Fc Receptor and Monoclonal Antibody Variants by Hydrogen/Deuterium Exchange Mass Spectrometry*

PubMed Central

Jensen, Pernille Foged; Larraillet, Vincent; Schlothauer, Tilman; Kettenberger, Hubert; Hilger, Maximiliane; Rand, Kasper D.

2015-01-01

The recycling of immunoglobulins by the neonatal Fc receptor (FcRn) is of crucial importance in the maintenance of antibody levels in plasma and is responsible for the long half-lives of endogenous and recombinant monoclonal antibodies. From a therapeutic point of view there is great interest in understanding and modulating the IgG–FcRn interaction to optimize antibody pharmacokinetics and ultimately improve efficacy and safety. Here we studied the interaction between a full-length human IgG1 and human FcRn via hydrogen/deuterium exchange mass spectrometry and targeted electron transfer dissociation to map sites perturbed by binding on both partners of the IgG–FcRn complex. Several regions in the antibody Fc region and the FcRn were protected from exchange upon complex formation, in good agreement with previous crystallographic studies of FcRn in complex with the Fc fragment. Interestingly, we found that several regions in the IgG Fab region also showed reduced deuterium uptake. Our findings indicate the presence of hitherto unknown FcRn interaction sites in the Fab region or a possible conformational link between the IgG Fc and Fab regions upon FcRn binding. Further, we investigated the role of IgG glycosylation in the conformational response of the IgG–FcRn interaction. Removal of antibody glycans increased the flexibility of the FcRn binding site in the Fc region. Consequently, FcRn binding did not induce a similar conformational stabilization of deglycosylated IgG as observed for the wild-type glycosylated IgG. Our results provide new molecular insight into the IgG–FcRn interaction and illustrate the capability of hydrogen/deuterium exchange mass spectrometry to advance structural proteomics by providing detailed information on the conformation and dynamics of large protein complexes in solution. PMID:25378534

Characteristics of antibody responses induced in mice by protein allergens.

PubMed

Hilton, J; Dearman, R J; Sattar, N; Basketter, D A; Kimber, I

1997-12-01

Whereas many foreign proteins are immunogenic, only a proportion is also allergenic, having the capacity to induce the quality of immune response necessary to support the production of IgE antibody. We have demonstrated previously that intraperitoneal administration to mice of proteins such as ovalbumin (OVA) or the industrial enzyme A. oryzae lipase, which possess significant allergenic potential, stimulates the production of both IgG and IgE antibody. Identical exposure to bovine serum albumin (BSA), a protein with limited potential to cause immediate respiratory or gastrointestinal hypersensitivity reactions, induced IgG responses only. In the current investigations, the quality of immune responses induced following exposure to these proteins via mucosal tissue (intranasal) has been compared with those provoked following administration via a non-mucosal (intraperitoneal) route of exposure. Intranasal or intraperitoneal administration of BSA, OVA or A. oryzae lipase elicited in each case vigorous IgG and IgG1 antibody responses. For all three proteins, at every concentration tested, and via both routes of exposure, IgG1 antibody titres paralleled closely IgG titres. However, the three materials displayed a differential potential to provoke IgE responses and this correlated with their known allergenic potential in humans. Thus, OVA and A. oryzae lipase stimulated strong IgE antibody responses, whereas BSA provoked low titre IgE only at the highest concentration tested (5% administered intraperitoneally). The quality of induced responses was not affected by the route of exposure. It would appear, therefore, that the stimulation of IgG and IgG1 antibody responses is a reflection of protein immunogenicity whereas protein allergenicity is associated with the induction of strong IgE responses.

Ventricular assist device elicits serum natural IgG that correlates with the development of primary graft dysfunction following heart transplantation.

PubMed

See, Sarah B; Clerkin, Kevin J; Kennel, Peter J; Zhang, Feifan; Weber, Matthew P; Rogers, Kortney J; Chatterjee, Debanjana; Vasilescu, Elena R; Vlad, George; Naka, Yoshifumi; Restaino, Susan W; Farr, Maryjane A; Topkara, Veli K; Colombo, Paolo C; Mancini, Donna M; Schulze, P Christian; Levin, Bruce; Zorn, Emmanuel

2017-08-01

Pre-transplant sensitization is a limiting factor in solid-organ transplantation. In heart transplants, ventricular assist device (VAD) implantation has been associated with sensitization to human leukocyte antigens (HLA). The effect of VAD on non-HLA antibodies is unclear. We have previously shown that polyreactive natural antibodies (Nabs) contribute to pre-sensitization in kidney allograft recipients. Here we assessed generation of Nabs after VAD implantation in pre-transplant sera and examined their contribution to cardiac allograft outcome. IgM and IgG Nabs were tested in pre-transplant serum samples collected from 206 orthotopic heart transplant recipients, including 128 patients with VAD (VAD patients) and 78 patients without VAD (no-VAD patients). Nabs were assessed by testing serum reactivity to apoptotic cells by flow cytometry and to the generic oxidized epitope, malondialdehyde, by enzyme-linked immunosorbent assay. No difference was observed in serum levels of IgM Nabs between VAD and no-VAD patients. However, serum IgG Nabs levels were significantly increased in VAD compared with no-VAD patients. This increase was likely due to the presence of the VAD, as revealed by lower serum IgG Nabs levels before implantation. Elevated pre-transplant IgG Nabs level was associated with development of primary graft dysfunction (PGD). Our study demonstrates that VAD support elicits IgG Nabs reactive to apoptotic cells and oxidized epitopes. These findings further support broad and non-specific B-cell activation by VAD, resulting in IgG sensitization. Moreover, the association of serum IgG Nabs levels with development of PGD suggests a possible role for these antibodies in the inflammatory reaction accompanying this complication. Copyright © 2017 International Society for the Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Autoantibodies to acetylcholinesterase revisited.

PubMed

Geen, J; Hadjikoutis, S; Strachan, A; Hullin, D A; Hogg, S I; Wiles, C M

2000-05-01

A sensitive and specific enzyme linked immunosorbent assay (ELISA) utilizing human recombinant acetylcholinesterase has been employed for the detection of human antibodies to human acetylcholinesterase. The method can detect allogenic antibodies to the Yt(a) form of human erythrocyte AChE. Adaptation of this ELISA method allowed the IgG subclass typing of IgG anti-AChE antibodies, which could help to determine the possible role of these antibodies in the aetiology of any neurological conditions. Routine serological investigations established the AChE phenotype of each of the patients recruited, to determine whether anti-AChE antibodies were allogenic or autogenic in origin. These techniques were used to determine the incidence of autoantibodies to AChE in patients with neurological conditions, including the subtypes of motor neuron disease. The data presented are not consistent with earlier reports of a high incidence of autoantibodies to AChE in amyotrophic lateral sclerosis and progressive muscular atrophy.

Neutron reflectivity measurement of protein A-antibody complex at the solid-liquid interface.

PubMed

Mazzer, Alice R; Clifton, Luke A; Perevozchikova, Tatiana; Butler, Paul D; Roberts, Christopher J; Bracewell, Daniel G

2017-05-26

Chromatography is a ubiquitous unit operation in the purification of biopharmaceuticals yet few studies have addressed the biophysical characterisation of proteins at the solution-resin interface. Chromatography and other adsorption and desorption processes have been shown to induce protein aggregation which is undesirable in biopharmaceutical products. In order to advance understanding of how adsorption processes might impact protein stability, neutron reflectivity was used to characterise the structure of adsorbed immunoglobulin G (IgG) on model surfaces. In the first model system, IgG was adsorbed directly to silica and demonstrated a side-on orientation with high surface contact. A maximum dimension of 60Å in the surface normal direction and high density surface coverage were observed under pH 4.1 conditions. In chromatography buffers, pH was found to influence IgG packing density and orientation at the solid-liquid interface. In the second model system, which was designed to mimic an affinity chromatography surface, protein A was attached to a silica surface to produce a configuration representative of a porous glass chromatography resin. Interfacial structure was probed during sequential stages from ligand attachment, through to IgG binding and elution. Adsorbed IgG structures extended up to 250Å away from the surface and showed dependence on surface blocking strategies. The data was suggestive of two IgG molecules bound to protein A with a somewhat skewed orientation and close proximity to the silica surface. The findings provide insight into the orientation of adsorbed antibody structures under conditions encountered during chromatographic separations. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.