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Sample records for complement lectin pathway

  1. Fibrinogen-specific antibody induces abdominal aortic aneurysm in mice through complement lectin pathway activation

    PubMed Central

    Zhou, Hui-fang; Yan, Huimin; Bertram, Paula; Hu, Ying; Springer, Luke E.; Thompson, Robert W.; Curci, John A.; Hourcade, Dennis E.; Pham, Christine T. N.

    2013-01-01

    Abdominal aortic aneurysm (AAA) is a common vascular disease associated with high mortality rate due to progressive enlargement and eventual rupture. There is currently no established therapy known to alter the rate of aneurysmal expansion. Thus, understanding the processes that initiate and sustain aneurysmal growth is pivotal for the development of medical therapies aimed at halting disease progression. Using an elastase-induced AAA mouse model that recapitulates key features of human AAA, we previously reported that a natural IgG antibody directs alternative pathway complement activation and initiates the inflammatory process that culminates in aneurysmal development. The target of this natural antibody, however, was unknown. Herein we identify a natural IgG that binds to fibrinogen deposited in elastase-perfused aortic tissues, activates the complement lectin pathway (LP), and induces AAA. Moreover, we establish that alterations in the glycosylation patterns of this antibody critically affect its ability to activate the LP in vivo. We find that LP activation precedes the alternative pathway and absence of the LP complement protein mannan-binding lectin abrogates elastase-induced AAA. In human AAA tissues the mouse anti-fibrinogen antibody recognizes epitopes that localize to the same areas that stain positively for mannan-binding lectin, which suggests that the complement LP is engaged in humans as well. Lastly, we demonstrate that circulating antibodies in a subset of AAA patients react against fibrinogen or fibrinogen-associated epitopes in human aneurysmal tissues. Our findings support the concept that an autoimmune process directed at aortic wall self-antigens may play a central role in the immunopathogenesis of AAA. PMID:24167262

  2. Critical Role and Therapeutic Control of the Lectin Pathway of Complement Activation in an Abortion-Prone Mouse Mating.

    PubMed

    Petitbarat, Marie; Durigutto, Paolo; Macor, Paolo; Bulla, Roberta; Palmioli, Alessandro; Bernardi, Anna; De Simoni, Maria-Grazia; Ledee, Nathalie; Chaouat, Gerard; Tedesco, Francesco

    2015-12-15

    The abortion-prone mating combination CBA/J × DBA/2 has been recognized as a model of preeclampsia, and complement activation has been implicated in the high rate of pregnancy loss observed in CBA/J mice. We have analyzed the implantation sites collected from DBA/2-mated CBA/J mice for the deposition of the complement recognition molecules using CBA/J mated with BALB/c mice as a control group. MBL-A was observed in the implantation sites of CBA/J × DBA/2 combination in the absence of MBL-C and was undetectable in BALB/c-mated CBA/J mice. Conversely, C1q was present in both mating combinations. Searching for other complement components localized at the implantation sites of CBA/J × DBA/2, we found C4 and C3, but we failed to reveal C1r. These data suggest that complement is activated through the lectin pathway and proceeds to completion of the activation sequence as revealed by C9 deposition. MBL-A was detected as early as 3.5 d of pregnancy, and MBL-A deficiency prevented pregnancy loss in the abortion-prone mating combination. The contribution of the terminal complex to miscarriage was supported by the finding that pregnancy failure was largely inhibited by the administration of neutralizing Ab to C5. Treatment of DBA/2-mated CBA/J mice with Polyman2 that binds to MBL-A with high affinity proved to be highly effective in controlling the activation of the lectin pathway and in preventing fetal loss. PMID:26561549

  3. Genetically engineered fusion of MAP-1 and factor H domains 1-5 generates a potent dual upstream inhibitor of both the lectin and alternative complement pathways.

    PubMed

    Nordmaj, Mie Anemone; Munthe-Fog, Lea; Hein, Estrid; Skjoedt, Mikkel-Ole; Garred, Peter

    2015-12-01

    Inhibition of the complement cascade has emerged as an option for treatment of a range of diseases. Mannose-binding lectin/ficolin/collectin-associated protein (MAP-1) is a pattern recognition molecule (PRM)-associated inhibitor of the lectin pathway. The central regulator of the alternative pathway (AP) is complement factor H (FH). Our aim was to design a dual upstream inhibitor of both human lectin and APs by fusing MAP-1 with a part of FH. There were 2 different recombinant chimeric proteins comprising full-length human MAP-1 and the first 5 N-terminal domains of human FH designed. The FH domains were orientated either in the N- or C-terminal part of MAP-1. The complement inhibition potential in human serum was assessed. Both chimeric constructs displayed the characteristics of the native molecules and bound to the PRMs with an EC50 of ?2 nM. However, when added to serum diluted 1:4 in a solid-phase functional assay, only the first 5 N-terminal domains of complement FH fused to the C-terminal part of full-length MAP-1 chimeric construct were able to combine inhibition of lectin and AP activation with an half maximal inhibitory concentration of ?100 and 20 nM, respectively. No effect was seen on the classical pathway. Fusion of MAP-1 with FH domains represents a novel therapeutic approach for selective targeting upstream and central complement activation at sites of inflammation.-Nordmaj, M. A., Munthe-Fog, L., Hein, E., Skjoedt, M.-O., Garred, P. Genetically engineered fusion of MAP-1 and factor H domains 1-5 generates a potent dual upstream inhibitor of both the lectin and alternative complement pathways. PMID:26260032

  4. Deletion of wboA Enhances Activation of the Lectin Pathway of Complement in Brucella abortus and Brucella melitensis

    PubMed Central

    Fernandez-Prada, Carmen M.; Nikolich, Mikeljon; Vemulapalli, Ramesh; Sriranganathan, Nammalwar; Boyle, Stephen M.; Schurig, Gerhardt G.; Hadfield, Ted L.; Hoover, David L.

    2001-01-01

    Brucella spp. are gram-negative intracellular pathogens that survive and multiply within phagocytic cells of their hosts. Smooth organisms present O polysaccharides (OPS) on their surface. These OPS help the bacteria avoid the bactericidal action of serum. The wboA gene, coding for the enzyme glycosyltransferase, is essential for the synthesis of O chain in Brucella. In this study, the sensitivity to serum of smooth, virulent Brucella melitensis 16M and B. abortus 2308, rough wboA mutants VTRM1, RA1, and WRR51 derived from these two Brucella species, and the B. abortus vaccine strain RB51 was assayed using normal nonimmune human serum (NHS). The deposition of complement components and mannose-binding lectin (MBL) on the bacterial surface was detected by flow cytometry. Rough B. abortus mutants were more sensitive to the bactericidal action of NHS than were rough B. melitensis mutants. Complement components were deposited on smooth strains at a slower rate compared to rough strains. Deposition of iC3b and C5b-9 and bacterial killing occurred when bacteria were treated with C1q-depleted, but not with C2-depleted serum or NHS in the presence of Mg-EGTA. These results indicate that (i) OPS-deficient strains derived from B. melitensis 16M are more resistant to the bactericidal action of NHS than OPS-deficient strains derived from B. abortus 2308, (ii) both the classical and the MBL-mediated pathways are involved in complement deposition and complement-mediated killing of Brucella, and (iii) the alternative pathway is not activated by smooth or rough brucellae. PMID:11401980

  5. Studies of the binding of ficolin-2 and ficolin-3 from the complement lectin pathway to Leptospira biflexa, Pasteurella pneumotropica and Diarrheagenic Escherichia coli.

    PubMed

    Sahagún-Ruiz, Alfredo; Breda, Leandro Carvalho Dantas; Valencia, Mónica Marcela Castiblanco; Elias, Waldir P; Munthe-Fog, Lea; Garred, Peter; Barbosa, Angela Silva; Isaac, Lourdes

    2015-10-01

    Ficolins recognize pathogen associated molecular patterns and activate the lectin pathway of complement system. However, our knowledge regarding pathogen recognition of human ficolins is still limited. We therefore set out to explore and investigate the possible interactions of the two main serum ficolins, ficolin-2 and ficolin-3 with different Gram-negative bacteria. We used recombinant ficolin molecules and normal human serum, which were detected with anti-ficolin monoclonal antibodies. In addition we investigated the capacity of these pathogens to activate the lectin pathway of complement system. We show for the first time that human ficolin-2 recognizes the nonpathogenic spirochete Leptospira biflexa serovar Patoc, but not the pathogenic Leptospira interrogans serovar Kennewicki strain Fromm. Additionally, human ficolin-2 and ficolin-3 recognize pathogenic Pasteurella pneumotropica, enteropathogenic Escherichia coli (EPEC) serotype O111ab:H2 and enteroaggregative E. coli (EAEC) serogroup O71 but not four enterohemorrhagic E. coli, three EPEC, three EAEC and two nonpathogenic E. coli strains (DH5? and HB101). The lectin pathway was activated by Pasteurella pneumotropica, EPEC O111ab:H2 and EAEC O71 after incubation with C1q depleted human serum. In conclusion, this study provide novel insight in the binding and complement activating capacity of the lectin pathway initiation molecules ficolin-2 and ficolin-3 towards relevant Gram-negative pathogens of pathophysiological relevance. PMID:26074063

  6. The Group B Streptococcus–Secreted Protein CIP Interacts with C4, Preventing C3b Deposition via the Lectin and Classical Complement Pathways

    PubMed Central

    Pietrocola, Giampiero; Rindi, Simonetta; Rosini, Roberto; Buccato, Scilla

    2016-01-01

    The group B Streptococcus (GBS) is a leading cause of neonatal invasive disease. GBS bacteria are surrounded by a thick capsular polysaccharide that is a potent inhibitor of complement deposition via the alternative pathway. Several of its surface molecules can however activate the classical and lectin complement pathways, rendering this species still vulnerable to phagocytic killing. In this study we have identified a novel secreted protein named complement interfering protein (CIP) that downregulates complement activation via the classical and lectin pathways, but not the alternative pathway. The CIP protein showed high affinity toward C4b and inhibited its interaction with C2, presumably preventing the formation of the C4bC2a convertase. Addition of recombinant CIP to GBS cip-negative bacteria resulted in decreased deposition of C3b on their surface and in diminished phagocytic killing in a whole-blood assay. Our data reveal a novel strategy exploited by GBS to counteract innate immunity and could be valuable for the development of anti-infective agents against this important pathogen. PMID:26608922

  7. The Group B Streptococcus-Secreted Protein CIP Interacts with C4, Preventing C3b Deposition via the Lectin and Classical Complement Pathways.

    PubMed

    Pietrocola, Giampiero; Rindi, Simonetta; Rosini, Roberto; Buccato, Scilla; Speziale, Pietro; Margarit, Immaculada

    2016-01-01

    The group B Streptococcus (GBS) is a leading cause of neonatal invasive disease. GBS bacteria are surrounded by a thick capsular polysaccharide that is a potent inhibitor of complement deposition via the alternative pathway. Several of its surface molecules can however activate the classical and lectin complement pathways, rendering this species still vulnerable to phagocytic killing. In this study we have identified a novel secreted protein named complement interfering protein (CIP) that downregulates complement activation via the classical and lectin pathways, but not the alternative pathway. The CIP protein showed high affinity toward C4b and inhibited its interaction with C2, presumably preventing the formation of the C4bC2a convertase. Addition of recombinant CIP to GBS cip-negative bacteria resulted in decreased deposition of C3b on their surface and in diminished phagocytic killing in a whole-blood assay. Our data reveal a novel strategy exploited by GBS to counteract innate immunity and could be valuable for the development of anti-infective agents against this important pathogen. PMID:26608922

  8. H-ficolin binds Aspergillus fumigatus leading to activation of the lectin complement pathway and modulation of lung epithelial immune responses.

    PubMed

    Bidula, Stefan; Sexton, Darren W; Yates, Matthew; Abdolrasouli, Alireza; Shah, Anand; Wallis, Russell; Reed, Anna; Armstrong-James, Darius; Schelenz, Silke

    2015-10-01

    Aspergillus fumigatus is an opportunistic fungal pathogen that typically infects the lungs of immunocompromised patients leading to a high mortality. H-Ficolin, an innate immune opsonin, is produced by type II alveolar epithelial cells and could participate in lung defences against infections. Here, we used the human type II alveolar epithelial cell line, A549, to determine the involvement of H-ficolin in fungal defence. Additionally, we investigated the presence of H-ficolin in bronchoalveolar lavage fluid from transplant patients during pneumonia. H-Ficolin exhibited demonstrable binding to A. fumigatus conidia via l-fucose, d-mannose and N-acetylglucosamine residues in a calcium- and pH-dependent manner. Moreover, recognition led to lectin complement pathway activation and enhanced fungal association with A549 cells. Following recognition, H-ficolin opsonization manifested an increase in interleukin-8 production from A549 cells, which involved activation of the intracellular signalling pathways mitogen-activated protein kinase MAPK kinase 1/2, p38 MAPK and c-Jun N-terminal kinase. Finally, H-ficolin concentrations were significantly higher in bronchoalveolar lavage fluid of patients with lung infections compared with control subjects (n = 16; P = 0·00726). Receiver operating characteristics curve analysis further highlighted the potential of H-ficolin as a diagnostic marker for lung infection (area under the curve = 0·77; P < 0·0001). Hence, H-ficolin participates in A. fumigatus defence through the activation of the lectin complement pathway, enhanced fungus-host interactions and modulated immune responses. PMID:26133042

  9. Essential Role for the Lectin Pathway in Collagen Antibody-Induced Arthritis Revealed Through Use of Adenovirus Programming Complement Inhibitor MAp44 Expression

    PubMed Central

    Banda, Nirmal K.; Mehta, Gaurav; Kjaer, Troels R.; Takahashi, Minoru; Schaack, Jerome; Morrison, Thomas E.; Thiel, Steffen; Arend, William P.; Holers, V. Michael

    2014-01-01

    Previous studies using mannose-binding lectin (MBL) and complement C4 deficient mice have suggested that the lectin pathway (LP) is not required for the development of inflammatory arthritis in the collagen antibody-induced arthritis (CAIA) model. MBL, ficolins and collectin-11 are key LP pattern recognition molecules that associate with three serine proteases, MASP-1, MASP-2 and MASP-3, and also with two MBL-associated proteins designated sMAP and MAp44. Recent studies have shown that MAp44, an alternatively spliced product of the MASP-1/3 gene, is a competitive inhibitor of the binding of the recognition molecules to all three MASPs. In these studies we examined the effect of treatment of mice with adenovirus (Ad) programmed to express human MAp44 (AdhMAp44) on the development of CAIA. AdhMAp44 and Ad programming Green fluorescent protein (AdGFP) expression were injected intraperitoneally in C57BL/6 wild-type mice prior to the induction of CAIA. AdhMAp44 significantly reduced the clinical disease activity score (CDA) by 81% compared to mice injected with AdGFP. Similarly, histopathologic injury scores for inflammation, pannus, cartilage and bone damage, as well as C3 deposition in the cartilage and synovium, were significantly reduced by AdhMAp44 pretreatment. Mice treated with AdmMAp44, programming expression of mouse MAp44, also showed significantly decreased CDA and histopathologic injury scores. Additionally, administration of AdhMAp44 significantly diminished the severity of Ross River Virus-induced arthritis, a LP-dependent model. Our study provides conclusive evidence that an intact complement LP is essential to initiate CAIA, and that MAp44 may be an appropriate treatment for inflammatory arthritis. PMID:25070856

  10. Low Invasiveness of Pneumococcal Serotype 11A Is Linked to Ficolin-2 Recognition of O-acetylated Capsule Epitopes and Lectin Complement Pathway Activation

    PubMed Central

    Brady, Allison M.; Calix, Juan J.; Yu, Jigui; Geno, Kimball Aaron; Cutter, Gary R.; Nahm, Moon H.

    2014-01-01

    Background.?The divergent epidemiological behavior of Streptococcus pneumoniae serotypes suggests that serotype-specific features such as capsule O-acetylation influence the propensity of a strain to cause invasive pneumococcal disease (IPD). We hypothesize that innate host factors mediate the observed negative association between IPD and the serotype 11A (ST11A) capsule O-acetyltransferase gene, wcjE. Methods.?We evaluated the ability of ficolin-2, an initiator of the lectin complement pathway that was previously shown to bind ST11A pneumococci, to recognize and mediate complement-dependent opsonophagocytosis of different pneumococcal serotypes. We supplemented findings with an epidemiological meta-analysis comparing invasiveness of the 30 most prevalent pneumococcal serotypes. Results.?Ficolin-2 bound ST11A capsule polysaccharide and other wcjE-containing pneumococcal serotypes, except ST9V and ST20B. Ficolin-2 did not bind wcjE-null serotypes, including the wcjE-null variant of ST11A, ST11E. We observed C1q-independent complement deposition and phagocytic killing of pneumococci expressing ST11A but not those expressing ST11E. Inhibition of ficolin-2 binding abrogated ST11A-associated complement deposition and phagocytosis. In children, invasiveness of ST11A was the lowest among serotypes tested in our meta-analysis, while ST9V was among the highest. Conclusions.?Ficolin-2 mediates serum protection by recognizing specific O-acetylated epitopes of pneumococcal capsule polysaccharides, exemplifying a novel host-microbe interaction that innately offers serotype-specific immunity to IPD. PMID:24683196

  11. Human mannan-binding lectin inhibits the infection of influenza A virus without complement

    PubMed Central

    Kase, T; Suzuki, Y; Kawai, T; Sakamoto, T; Ohtani, K; Eda, S; Maeda, A; Okuno, Y; Kurimura, T; Wakamiya, N

    1999-01-01

    Mannan-binding lectin (MBL) is a C-type serum lectin that is believed to play an important role in innate immunity. It is one of the collectin family, which is characterized by having a collagen-like sequence and a carbohydrate recognition domain. MBL can bind to sugar determinants of several micro-organisms, neutralize them and inhibit infection by complement activation through the lectin pathway and opsonization by collectin receptors. Bovine conglutinin and mouse MBL inhibit the infective and haemagglutinating activities of influenza A viruses. To identify the direct antiviral activity of human MBL against influenza A viruses that does not depend on complement activation or opsonization, we isolated native MBL from human serum and produced a recombinant MBL in Chinese hamster ovary (CHO) cells using a pNOW/CMV-A expression vector system. Native and recombinant human MBL exhibited neutralization activity against A/Ibaraki/1/90 (H3N2), with the plaque focus reduction assay at the viral attachment phase. Their activities were inhibited by EDTA, mannose and anti-human MBL antibody. Furthermore, at the viral expansion phase both MBL in culture medium prevented viral spreading from primary infected cells to neighbour cells. A virus recovery study using EDTA indicated that interaction between MBL and virus was reversible and non-damaging to the virus. Lectin blot and immunohistochemistry assays showed that these antiviral activities involved binding between MBL and two viral envelope proteins, haemagglutinin and neuraminidase. These findings suggest that human MBL can play an important role in innate immunity by direct viral neutralization and inhibition of viral spread, as well as an indirect role through opsonization and complement activation. PMID:10447758

  12. Association Study of Mannose-Binding Lectin Levels and Genetic Variants in Lectin Pathway Proteins with Susceptibility to Age-Related Macular Degeneration: A Case-Control Study

    PubMed Central

    Osthoff, Michael; Dean, Melinda M.; Baird, Paul N.; Richardson, Andrea J.; Daniell, Mark; Guymer, Robyn H.; Eisen, Damon P.

    2015-01-01

    Background In age-related macular degeneration (AMD) the complement system is thought to be activated by chronic oxidative damage with genetic variants identified in the alternative pathway as susceptibility factors. However, the involvement of the lectin pathway of complement, a key mediator of oxidative damage, is controversial. This study investigated whether mannose-binding lectin (MBL) levels and genetic variants in lectin pathway proteins, are associated with the predisposition to and severity of AMD. Methods MBL levels and single nucleotide polymorphisms (SNPs) in the MBL2 and the ficolin-2 (FCN2) gene were determined in 109 patients with AMD and 109 age- and sex-matched controls. Results MBL expression levels were equally distributed in both cases (early and late AMD) and controls (p>0.05). However, there was a trend towards higher median MBL levels in cases with late AMD compared to cases with early AMD (1.0 vs. 0.4 ?g/ml, p = 0.09) and MBL deficiency (<0.5 ?g/ml) was encountered less frequently in the late AMD group (35% vs 56%, p = 0.03). FCN2 and MBL2 allele frequencies were similarly distributed in early and late AMD cases compared with controls (p>0.05 for all analyses) as were MBL2 genotypes. Similarly, there was no significant difference in allele frequencies in any SNPs in either the MBL2 or FCN2 gene in cases with early vs. late AMD. Conclusions SNPs of lectin pathway proteins investigated in this study were not associated with AMD or AMD severity. However, MBL levels deserve further study in a larger cohort of early vs. late AMD patients to elucidate any real effect on AMD severity. PMID:26207622

  13. Crystal Structure and Functional Characterization of the Complement Regulator Mannose-binding Lectin (MBL)/Ficolin-associated Protein-1 (MAP-1)*

    PubMed Central

    Skjoedt, Mikkel-Ole; Roversi, Pietro; Hummelshřj, Tina; Palarasah, Yaseelan; Rosbjerg, Anne; Johnson, Steven; Lea, Susan M.; Garred, Peter

    2012-01-01

    The human lectin complement pathway activation molecules comprise mannose-binding lectin (MBL) and ficolin-1, -2, and -3 in complex with associated serine proteases MASP-1, -2, and -3 and the non-enzymatic small MBL associated protein or sMAP. Recently, a novel plasma protein named MBL/ficolin-associated protein-1 (MAP-1) was identified in humans. This protein is the result of a differential splicing of the MASP1 gene and includes the major part of the heavy chain but lacks the serine protease domain. We investigated the direct interactions of MAP-1 and MASP-3 with ficolin-3 and MBL using surface plasmon resonance and found affinities around 5 nm and 2.5 nm, respectively. We studied structural aspects of MAP-1 and could show by multi-angle laser light scattering that MAP-1 forms a calcium-dependent homodimer in solution. We were able to determine the crystal structure of MAP-1, which also contains a head-to-tail dimer ?146 ? long. This structure of MAP-1 also enables modeling and assembly of the MASP-1 molecule in its entirety. Finally we found that MAP-1 competes with all three MASPs for ligand binding and is able to mediate a strong dose-dependent inhibitory effect on the lectin pathway activation, as measured by levels of C3 and C9. PMID:22854970

  14. HUMAN IMMUNOGLOBULIN GLYCOSYLATION AND THE LECTIN PATHWAY OF COMPLEMENT

    E-print Network

    immune system. They are glycoproteins which are found in all higher vertebrates (mammals, birds, reptilesA is secreted through epithelia into the mucous lining of the gastrointestinal and respiratory tract

  15. Classical Complement Pathway Activation in the Kidneys of Women With Preeclampsia.

    PubMed

    Penning, Marlies; Chua, Jamie S; van Kooten, Cees; Zandbergen, Malu; Buurma, Aletta; Schutte, Joke; Bruijn, Jan Anthonie; Khankin, Eliyahu V; Bloemenkamp, Kitty; Karumanchi, S Ananth; Baelde, Hans

    2015-07-01

    A growing body of evidence suggests that complement dysregulation plays a role in the pathogenesis of preeclampsia. The kidney is one of the major organs affected in preeclampsia. Because the kidney is highly susceptible to complement activation, we hypothesized that preeclampsia is associated with renal complement activation. We performed a nationwide search for renal autopsy material in the Netherlands using a computerized database (PALGA). Renal tissue was obtained from 11 women with preeclampsia, 25 pregnant controls, and 14 nonpregnant controls with hypertension. The samples were immunostained for C4d, C1q, mannose-binding lectin, properdin, C3d, C5b-9, IgA, IgG, and IgM. Preeclampsia was significantly associated with renal C4d-a stable marker of complement activation-and the classical pathway marker C1q. In addition, the prevalence of IgM was significantly higher in the kidneys of the preeclamptic women. No other complement markers studied differed between the groups. Our findings in human samples were validated using a soluble fms-like tyrosine kinase 1 mouse model of preeclampsia. The kidneys in the soluble fms-like tyrosine kinase 1-injected mice had significantly more C4 deposits than the control mice. The association between preeclampsia and renal C4d, C1q, and IgM levels suggests that the classical complement pathway is involved in the renal injury in preeclampsia. Moreover, our finding that soluble fms-like tyrosine kinase 1-injected mice develop excess C4 deposits indicates that angiogenic dysregulation may play a role in complement activation within the kidney. We suggest that inhibiting complement activation may be beneficial for preventing the renal manifestations of preeclampsia. PMID:25941343

  16. Neutrophil extracellular traps can activate alternative complement pathways.

    PubMed

    Wang, H; Wang, C; Zhao, M-H; Chen, M

    2015-09-01

    The interaction between neutrophils and activation of alternative complement pathway plays a pivotal role in the pathogenesis of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). ANCAs activate primed neutrophils to release neutrophil extracellular traps (NETs), which have recently gathered increasing attention in the development of AAV. The relationship between NETs and alternative complement pathway has not been elucidated. The current study aimed to investigate the relationship between NETs and alternative complement pathway. Detection of components of alternative complement pathway on NETs in vitro was assessed by immunostain and confocal microscopy. Complement deposition on NETs were detected after incubation with magnesium salt ethyleneglycol tetraacetic acid (Mg-EGTA)-treated human serum. After incubation of serum with supernatants enriched in ANCA-induced NETs, levels of complement components in supernatants were measured by enzyme-linked immunosorbent assay (ELISA). Complement factor B (Bb) and properdin deposited on NETs in vitro. The deposition of C3b and C5b-9 on NETs incubated with heat-inactivated normal human serum (Hi-NHS) or EGTA-treated Hi-NHS (Mg-EGTA-Hi-NHS) were significantly less than that on NETs incubated with NHS or EGTA-treated NHS (Mg-EGTA-NHS). NETs induced by ANCA could activate the alternative complement cascade in the serum. In the presence of EGTA, C3a, C5a and SC5b-9 concentration decreased from 800·42?±?244·81 ng/ml, 7·68?±?1·50 ng/ml, 382·15?±?159·75 ng/ml in the supernatants enriched in ANCA induced NETs to 479·07?±?156·2 ng/ml, 4·86?±?1·26 ng/ml, 212·65?±?44·40 ng/ml in the supernatants of DNase I-degraded NETs (P?complement pathway, and might thus participate in the pathogenesis of AAV. PMID:25963026

  17. Contribution of complement activation pathways to neuropathology differs among mouse models of Alzheimer's disease

    E-print Network

    2011-01-01

    of complement alternative pathway mRNA and proteins in theCom- plement proteins of the alternative pathway are alsoalternative pathway activation could occur, but that amplification is highly regulated (such as by the complement regulatory protein

  18. Differential Complement Activation Pathways Promote C3b Deposition on Native and Acetylated LDL thereby Inducing Lipoprotein Binding to the Complement Receptor 1

    PubMed Central

    Klop, Boudewijn; van der Pol, Pieter; van Bruggen, Robin; Wang, Yanan; de Vries, Marijke A.; van Santen, Selvetta; O'Flynn, Joseph; van de Geijn, Gert-Jan M.; Njo, Tjin L.; Janssen, Hans W.; de Man, Peter; Jukema, J. Wouter; Rabelink, Ton J.; Rensen, Patrick C. N.; van Kooten, Cees; Cabezas, Manuel Castro

    2014-01-01

    Lipoproteins can induce complement activation resulting in opsonization and binding of these complexes to complement receptors. We investigated the binding of opsonized native LDL and acetylated LDL (acLDL) to the complement receptor 1 (CR1). Binding of complement factors C3b, IgM, C1q, mannose-binding lectin (MBL), and properdin to LDL and acLDL were investigated by ELISA. Subsequent binding of opsonized LDL and acLDL to CR1 on CR1-transfected Chinese Hamster Ovarian cells (CHO-CR1) was tested by flow cytometry. Both native LDL and acLDL induced complement activation with subsequent C3b opsonization upon incubation with normal human serum. Opsonized LDL and acLDL bound to CR1. Binding to CHO-CR1 was reduced by EDTA, whereas MgEGTA only reduced the binding of opsonized LDL, but not of acLDL suggesting involvement of the alternative pathway in the binding of acLDL to CR1. In vitro incubations showed that LDL bound C1q, whereas acLDL bound to C1q, IgM, and properdin. MBL did neither bind to LDL nor to acLDL. The relevance of these findings was demonstrated by the fact that ex vivo up-regulation of CR1 on leukocytes was accompanied by a concomitant increased binding of apolipoprotein B-containing lipoproteins to leukocytes without changes in LDL-receptor expression. In conclusion, CR1 is able to bind opsonized native LDL and acLDL. Binding of LDL to CR1 is mediated via the classical pathway, whereas binding of acLDL is mediated via both the classical and alternative pathways. Binding of lipoproteins to CR1 may be of clinical relevance due to the ubiquitous cellular distribution of CR1. PMID:25349208

  19. Differential complement activation pathways promote C3b deposition on native and acetylated LDL thereby inducing lipoprotein binding to the complement receptor 1.

    PubMed

    Klop, Boudewijn; van der Pol, Pieter; van Bruggen, Robin; Wang, Yanan; de Vries, Marijke A; van Santen, Selvetta; O'Flynn, Joseph; van de Geijn, Gert-Jan M; Njo, Tjin L; Janssen, Hans W; de Man, Peter; Jukema, J Wouter; Rabelink, Ton J; Rensen, Patrick C N; van Kooten, Cees; Cabezas, Manuel Castro

    2014-12-19

    Lipoproteins can induce complement activation resulting in opsonization and binding of these complexes to complement receptors. We investigated the binding of opsonized native LDL and acetylated LDL (acLDL) to the complement receptor 1 (CR1). Binding of complement factors C3b, IgM, C1q, mannose-binding lectin (MBL), and properdin to LDL and acLDL were investigated by ELISA. Subsequent binding of opsonized LDL and acLDL to CR1 on CR1-transfected Chinese Hamster Ovarian cells (CHO-CR1) was tested by flow cytometry. Both native LDL and acLDL induced complement activation with subsequent C3b opsonization upon incubation with normal human serum. Opsonized LDL and acLDL bound to CR1. Binding to CHO-CR1 was reduced by EDTA, whereas MgEGTA only reduced the binding of opsonized LDL, but not of acLDL suggesting involvement of the alternative pathway in the binding of acLDL to CR1. In vitro incubations showed that LDL bound C1q, whereas acLDL bound to C1q, IgM, and properdin. MBL did neither bind to LDL nor to acLDL. The relevance of these findings was demonstrated by the fact that ex vivo up-regulation of CR1 on leukocytes was accompanied by a concomitant increased binding of apolipoprotein B-containing lipoproteins to leukocytes without changes in LDL-receptor expression. In conclusion, CR1 is able to bind opsonized native LDL and acLDL. Binding of LDL to CR1 is mediated via the classical pathway, whereas binding of acLDL is mediated via both the classical and alternative pathways. Binding of lipoproteins to CR1 may be of clinical relevance due to the ubiquitous cellular distribution of CR1. PMID:25349208

  20. Carbamylation of immunoglobulin abrogates activation of the classical complement pathway

    PubMed Central

    Koro, Catalin; Bielecka, Ewa; Dahl-Knudsen, Anders; Enghild, Jan J; Scavenius, Carsten; Brun, Johan G; Binder, Veronika; Hellvard, Annelie; Bergum, Brith; Jonsson, Roland; Potempa, Jan; Blom, Anna M; Mydel, Piotr

    2014-01-01

    Post-translational modifications of proteins significantly affect their structure and function. The carbamylation of positively charged lysine residues to form neutral homoitrulline occurs primarily under inflammatory conditions through myeloperoxidase-dependent cyanate (CNO?) formation. We analyzed the pattern of human IgG1 carbamylation under inflammatory conditions and the effects that this modification has on the ability of antibodies to trigger complement activation via the classical pathway. We found that the lysine residues of IgG1 are rapidly modified after brief exposure to CNO?. Interestingly, modifications were not random, but instead limited to only few lysines within the hinge area and the N-terminal fragment of the CH2 domain. A complement activation assay combined with mass spectrometry analysis revealed a highly significant inverse correlation between carbamylation of several key lysine residues within the hinge region and N-terminus of the CH2 domain and the proper binding of C1q to human IgG1 followed by subsequent complement activation. This severely hindered complement-dependent cytotoxicity of therapeutic IgG1. The reaction can apparently occur in vivo, as we found carbamylated antibodies in synovial fluid from rheumatoid arthritis patients. Taken together, our data suggest that carbamylation has a profound impact on the complement-activating ability of IgG1 and reveals a pivotal role for previously uncharacterized lysine residues in this process. PMID:25130613

  1. Therapeutic Inhibition of the Alternative Complement Pathway Attenuates Chronic EAE

    PubMed Central

    Hu, Xianzhen; Holers, V. Michael; Thurman, Joshua M.; Schoeb, Trent R.; Ramos, Theresa N; Barnum, Scott R.

    2013-01-01

    Previous studies from our laboratory using complement-mutant mice demonstrated that the alternative pathway is the dominant activation pathway responsible for complement-mediated pathology in demyelinating disease. Using a well-characterized inhibitory monoclonal antibody (mAb 1379) directed against mouse factor B, we assessed the therapeutic value of inhibiting the alternative complement pathway in experimental autoimmune encephalomyelitis (EAE), the animal model for multiple sclerosis. Administration of anti-factor B antibody to mice prior to the onset of clinical signs of active EAE had no affect on the onset or acute phase of disease, but significantly attenuated the chronic phase of disease resulting in reduced cellular infiltration, inflammation and demyelination in antibody-treated mice. Attenuation of the chronic phase of disease was long lasting even though antibody administration was terminated shortly after disease onset. Chronic disease was also attenuated in transferred EAE when anti-factor B antibody was administered before or after disease onset. Similar levels of disease attenuation were observed in transferred EAE using MOG-specific encephalitogenic T cells. These studies demonstrate the therapeutic potential for inhibition of factor B in the chronic phase of demyelinating disease, where treatment options are limited. PMID:23337717

  2. ISJ 2: 114-123, 2005 ISSN 1824-307X Ancient origins: complement in invertebrates

    E-print Network

    Raftos, David

    and tunicates express proteins that are homologues of C3, the central component of the vertebrate complement activation pathway; and tunicates have collagenous lectins of the type that can activate complement

  3. An amphioxus gC1q protein binds human IgG and initiates the classical pathway: Implications for a C1q-mediated complement system in the basal chordate.

    PubMed

    Gao, Zhan; Li, Mengyang; Ma, Jie; Zhang, Shicui

    2014-12-01

    The origin of the classical complement pathway remains open during chordate evolution. A C1q-like member, BjC1q, was identified in the basal chordate amphioxus. It is predominantly expressed in the hepatic caecum, hindgut, and notochord, and is significantly upregulated following challenge with bacteria or lipoteichoic acid and LPS. Recombinant BjC1q and its globular head domain specifically interact with lipoteichoic acid and LPS, but BjC1q displays little lectin activity. Moreover, rBjC1q can assemble to form the high molecular weight oligomers necessary for binding to proteases C1r/C1s and for complement activation, and binds human C1r/C1s/mannan-binding lectin-associated serine protease-2 as well as amphioxus serine proteases involved in the cleavage of C4/C2, and C3 activation. Importantly, rBjC1q binds with human IgG as well as an amphioxus Ig domain containing protein, resulting in the activation of the classical complement pathway. This is the first report showing that a C1q-like protein in invertebrates is able to initiate classical pathway, raising the possibility that amphioxus possesses a C1q-mediated complement system. It also suggests a new scenario for the emergence of the classical complement pathway, in contrast to the proposal that the lectin pathway evolved into the classical pathway. PMID:25174509

  4. Characterization of mannose binding lectin from channel catfish Ictalurus punctatus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mannose-binding lectin (MBL) is an important component of innate immunity capable of activating the lectin pathway of the complement system. A MBL gene was isolated from channel catfish (Ictalurus punctatus). The deduced protein contains a canonical collagen-like domain, a carbohydrate recognition d...

  5. Time-course analysis of C3a and C5a quantifies the coupling between the upper and terminal Complement pathways in vitro.

    PubMed

    Morad, Hassan O J; Belete, Samuel C; Read, Thomas; Shaw, Andrew M

    2015-12-01

    An in vitro zymosan-activation of the Complement system, through the lectin and alternative pathways, was performed in pooled human serum over a 24h time-course. Activation was quantitatively monitored by measuring the concentration of the upper Complement pathway fragment, C3a and the terminal pathway fragment, C5a. Upper Complement showed a maximum activation of 39% and the time-to-maximum activation reduced 8-fold, as a highly non-linear function of the zymosan dose. The C3a:C5a molar ratio rose to a maximum of 1100:1, before terminal pathway activation was initiated; indicating a flux threshold. This threshold appears to be exceeded once more than 31% of C3 molecules are activated. Above this threshold, significant activation of terminal pathway was observed; reducing the molar ratio to 17:1. The C5a/C3a molar ratio was used to determine the terminal pathway activation relative to total Complement activation and ranged from 0.1-0.8%. This depicts upper Complement activation to be 49-fold larger than terminal activation, a figure consistent with the observed density of the membrane attack complex in the membrane of cells. Our results thus indicate that the relative activity of opsonisation is ~50-fold greater than membrane attack complex formation, in vitro, in the pooled serum phenotype. The results suggest a potential clinical application, where an in vitro analysis of a patient on admission, or prior to a surgical procedure, would indicate their upper Complement activation capacity, with activation of C3 measured thereafter, or post-operatively. A patient with an exhausted upper Complement capacity may be vulnerable to infections and complications, such as sepsis. PMID:26391915

  6. Review on complement analysis method and the roles of glycosaminoglycans in the complement system.

    PubMed

    Li, Lian; Li, Yan; Ijaz, Muhammad; Shahbaz, Muhammad; Lian, Qianqian; Wang, Fengshan

    2015-12-10

    Complement system is composed of over 30 proteins and it plays important roles in self-defence and inflammation. There are three activation pathways, including classical pathway, alternative pathway and lectin pathway, in complement system, and they are associated with many diseases such as osteoarthritis and age-related macular degeneration. Modulation of the complement system may be a promising strategy in the treatment of related diseases. Glycosaminoglycans are anionic linear polysaccharides without branches. They are one kind of multi-functional macromolecules which have great potential in regulating complement system. This review is organized around two aspects between the introduction of complement system and the interaction of glycosaminoglycans with complement system. Three complement activation pathways and the biological significance were introduced first. Then functional analysis methods were compared to provide a strategy for potential glycosaminoglycans screen. Finally, the roles of glycosaminoglycans played in the complement system were summed up. PMID:26428162

  7. Activation of the human terminal complement pathway in atherosclerosis.

    PubMed

    Niculescu, F; Rus, H G; Vlaicu, R

    1987-11-01

    The presence of the terminal C5b-9 complement complex in tissues indicates that complement activation has occurred in situ with subsequent membrane damage, tissue injury, and inflammatory response mediation. The terminal C5b-9 neoantigens of the complement system, S protein C3c, C3d, and apolipoprotein B deposits were localized in 20 aortic fibrous plaques, 12 aortic intimal thickenings, 8 aortic fatty streak intimae, 14 coronary fibrous plaques, 5 coronary intimal thickenings, and 8 femoral fibrous plaques, using an indirect and double-staining immunoperoxidase technique. The specific granular deposits were present from the early to the advanced stages of atherosclerosis in relation to the degree of fibrosis and necrosis. The different double-staining localization of C5b-9 and S protein may suggest local assembly of the complex as a consequence of complement activation and may sustain its role in the chronic progression of atherosclerosis. PMID:2444373

  8. Blockade of Alternative Complement Pathway in Dense Deposit Disease

    PubMed Central

    Sacquépée, Mathieu; Fila, Marc; Peuchmaur, Michel; Perrier-Cornet, Emilia; Frémeaux-Bacchi, Véronique; Deschęnes, Georges

    2014-01-01

    A patient aged 17 with dense deposit disease associated with complement activation, circulating C3 Nef, and Factor H mutation presented with nephrotic syndrome and hypertension. Steroid therapy, plasma exchange, and rituximab failed to improve proteinuria and hypertension despite a normalization of the circulating sC5b9 complex. Eculizumab, a monoclonal antibody directed against C5, was used to block the terminal product of the complement cascade. The dose was adapted to achieve a CH50 below 10%, but proteinuria and blood pressure were not improved after 3 months of treatment. PMID:24672732

  9. Effective Neutrophil Phagocytosis of Aspergillus fumigatus Is Mediated by Classical Pathway Complement Activation.

    PubMed

    Braem, Steven G E; Rooijakkers, Suzan H M; van Kessel, Kok P M; de Cock, Hans; Wösten, Han A B; van Strijp, Jos A G; Haas, Pieter-Jan A

    2015-01-01

    Aspergillus fumigatus is an important airborne fungal pathogen and a major cause of invasive fungal infections. Susceptible individuals become infected via the inhalation of dormant conidia. If the immune system fails to clear these conidia, they will swell, germinate and grow into large hyphal structures. Neutrophils are essential effector cells for controlling A. fumigatus infection. In general, opsonization of microbial particles is crucial for efficient phagocytosis and killing by neutrophils. Although the antibodies present in human serum do bind to all fungal morphotypes, we observed no direct antibody-mediated phagocytosis of A. fumigatus. We show that opsonization, phagocytosis and killing by neutrophils of A. fumigatus is complement-dependent. Using human sera depleted of key complement components, we investigated the contribution of the different complement initiation pathways in complement activation on the fungal surface. We describe the classical complement pathway as the main initiator of complement activation on A. fumigatus swollen conidia and germ tubes. Antibodies play an important role in complement activation and efficient innate recognition, phagocytosis and killing of A. fumigatus by neutrophils. PMID:25676601

  10. Alternative Complement Pathway Deficiency Ameliorates Chronic Smoke-Induced Functional and Morphological Ocular Injury

    PubMed Central

    Woodell, Alex; Coughlin, Beth; Kunchithapautham, Kannan; Casey, Sarah; Williamson, Tucker; Ferrell, W. Drew; Atkinson, Carl; Jones, Bryan W.; Rohrer, Bärbel

    2013-01-01

    Background Age-related macular degeneration (AMD), a complex disease involving genetic variants and environmental insults, is among the leading causes of blindness in Western populations. Genetic and histologic evidence implicate the complement system in AMD pathogenesis; and smoking is the major environmental risk factor associated with increased disease risk. Although previous studies have demonstrated that cigarette smoke exposure (CE) causes retinal pigment epithelium (RPE) defects in mice, and smoking leads to complement activation in patients, it is unknown whether complement activation is causative in the development of CE pathology; and if so, which complement pathway is required. Methods Mice were exposed to cigarette smoke or clean, filtered air for 6 months. The effects of CE were analyzed in wildtype (WT) mice or mice without a functional complement alternative pathway (AP; CFB?/?) using molecular, histological, electrophysiological, and behavioral outcomes. Results CE in WT mice exhibited a significant reduction in function of both rods and cones as determined by electroretinography and contrast sensitivity measurements, concomitant with a thinning of the nuclear layers as measured by SD-OCT imaging and histology. Gene expression analyses suggested that alterations in both photoreceptors and RPE/choroid might contribute to the observed loss of function, and visualization of complement C3d deposition implies the RPE/Bruch's membrane (BrM) complex as the target of AP activity. RPE/BrM alterations include an increase in mitochondrial size concomitant with an apical shift in mitochondrial distribution within the RPE and a thickening of BrM. CFB?/? mice were protected from developing these CE-mediated alterations. Conclusions Taken together, these findings provide clear evidence that ocular pathology generated in CE mice is dependent on complement activation and requires the AP. Identifying animal models with RPE/BrM damage and verifying which aspects of pathology are dependent upon complement activation is essential for developing novel complement-based treatment approaches for the treatment of AMD. PMID:23825688

  11. Complement activation by salivary agglutinin is secretor status dependent.

    PubMed

    Gunput, Sabrina T G; Ligtenberg, Antoon J M; Terlouw, Bas; Brouwer, Mieke; Veerman, Enno C I; Wouters, Diana

    2015-01-01

    After mucosal damage or gingival inflammation, complement proteins leak into the oral cavity and mix with salivary proteins such as salivary agglutinin (SAG/gp-340/DMBT1). This protein is encoded by the gene Deleted in Malignant Brain Tumors 1 (DMBT1), and it aggregates bacteria, viruses and fungi, and activates the lectin pathway of the complement system. In the lectin pathway, carbohydrate structures on pathogens or altered self cells are recognized. SAG is highly glycosylated, partly on the basis of the donor's blood group status. Whereas secretors express Lewis b, Lewis y, and antigens from the ABO-blood group system on SAG, non-secretors do not. Through mannose-binding lectin (MBL) binding and C4 deposition assays, we aimed to identify the chemical structures on SAG that are responsible for complement activation. The complement-activating properties of SAG were completely abolished by oxidation of its carbohydrate moiety. SAG-mediated activation of complement was also inhibited in the presence of saccharides such as fucose and Lewis b carbohydrates, and also after pretreatment with the fucose-binding lectin, Anguilla anguilla agglutinin. Complement activation was significantly (p<0.01) higher in secretors than in non-secretors. Our results suggest that fucose-rich oligosaccharide sidechains, such as Lewis b antigens, are involved in the activation of complement by SAG. PMID:25153235

  12. Activation of the alternative complement pathway in canine normal serum by Paracoccidioides brasiliensis

    PubMed Central

    Bianchini, A.A.C.; Petroni, T.F.; Fedatto, P.F.; Bianchini, R.R.; Venancio, E.J.; Itano, E.N.; Ono, M.A.

    2009-01-01

    The dimorphic fungus Paracoccidioides brasiliensis is the etiological agent of paracoccidioidomycosis, a human granulomatous disease. Recently the first case of natural disease in dogs was reported. The complement system is an important effector component of humoral immunity against infectious agents. Therefore, the aim of this study was to evaluate the activation of the dog alternative complement pathway by P. brasiliensis. Initially, the ability of erythrocytes of guinea pig, rabbit, sheep, chicken and swine to activate the dog alternative pathway was evaluated. The guinea pig erythrocytes showed the greatest capacity to activate dog alternative pathway. The alternative (AH50) hemolytic activity was evaluated in 27 serum samples from healthy dogs and the mean values were 87.2 AH50/ml. No significant differences were observed in relation to sex and age. The alternative pathway activation by P. brasiliensis was higher in serum samples from adult dogs when compared to puppies and aged dogs (p ? 0.05). This is the first report of dog alternative complement pathway activation by P. brasiliensis and suggests that it may play a protective role in canine paracoccidioidomycosis. PMID:24031350

  13. Complement Pathway is Frequently Altered in Endometriosis and Endometriosis-Associated Ovarian Cancer

    PubMed Central

    Suryawanshi, Swati; Huang, Xin; Elishaev, Esther; Budiu, Raluca A.; Zhang, Lixin; Kim, SungHwan; Donnellan, Nicole; Mantia-Smaldone, Gina; Ma, Tianzhou; Tseng, George; Lee, Ted; Mansuria, Suketu; Edwards, Robert; Vlad, Anda M.

    2014-01-01

    Purpose Mechanisms of immune dysregulation associated with advanced tumors are relatively well understood. Much less is known about the role of immune effectors against cancer precursor lesions. Endometrioid and clear cell ovarian tumors partly derive from endometriosis, a commonly diagnosed chronic inflammatory disease. We performed here a comprehensive immune gene expression analysis of pelvic inflammation in endometriosis and endometriosis-associated ovarian cancer (EAOC). Experimental design RNA was extracted from 120 paraffin tissue blocks comprising of normal endometrium (n=32), benign endometriosis (n=30), atypical endometriosis (n=15) and EAOC (n=43). Serous tumors (n=15) were included as non-endometriosis associated controls. The immune microenvironment was profiled using Nanostring and the nCounter® GX Human Immunology Kit, comprising probes for a total of 511 immune genes. Results One third of the endometriosis patients revealed a tumor-like inflammation profile, suggesting that cancer–like immune signatures may develop earlier, in patients classified as clinically benign. Gene expression analyses revealed the complement pathway as most prominently involved in both endometriosis and EAOC. Complement proteins are abundantly present in epithelial cells in both benign and malignant lesions. Mechanistic studies in ovarian surface epithelial (OSE) cells from mice with conditional (Cre-loxP) mutations show intrinsic production of complement in epithelia and demonstrate an early link between Kras- and Pten-driven pathways and complement upregulation. Downregulation of complement in these cells interferes with cell proliferation. Conclusions These findings reveal new characteristics of inflammation in precursor lesions and point to previously unknown roles of complement in endometriosis and EAOC. PMID:25294912

  14. Properdin and Factor H: Opposing Players on the Alternative Complement Pathway “See-Saw”

    PubMed Central

    Kouser, Lubna; Abdul-Aziz, Munirah; Nayak, Annapurna; Stover, Cordula M.; Sim, Robert B.; Kishore, Uday

    2013-01-01

    Properdin and factor H are two key regulatory proteins having opposite functions in the alternative complement pathway. Properdin up-regulates the alternative pathway by stabilizing the C3bBb complex, whereas factor H downregulates the pathway by promoting proteolytic degradation of C3b. While factor H is mainly produced in the liver, there are several extrahepatic sources. In addition to the liver, factor H is also synthesized in fetal tubuli, keratinocytes, skin fibroblasts, ocular tissue, adipose tissue, brain, lungs, heart, spleen, pancreas, kidney, muscle, and placenta. Neutrophils are the major source of properdin, and it is also produced by monocytes, T cells and bone marrow progenitor cell line. Properdin is released by neutrophils from intracellular stores following stimulation by N-formyl-methionine-leucine-phenylalanine (fMLP) and tumor necrosis factor alpha (TNF-?). The HEP G2 cells derived from human liver has been found to produce functional properdin. Endothelial cells also produce properdin when induced by shear stress, thus is a physiological source for plasma properdin. The diverse range of extrahepatic sites for synthesis of these two complement regulators suggests the importance and need for local availability of the proteins. Here, we discuss the significance of the local synthesis of properdin and factor H. This assumes greater importance in view of recently identified unexpected and novel roles of properdin and factor H that are potentially independent of their involvement in complement regulation. PMID:23630525

  15. Alternative complement pathway activation by Salmonella O polysaccharide as a virulence determinant in the mouse.

    PubMed

    Saxén, H; Reima, I; Mäkelä, P H

    1987-01-01

    The quality of Salmonella O polysaccharide (the O antigen) is a virulence factor in mouse salmonellosis. It affects the rate by which these bacteria are phagocytosed and by which they activate the alternative complement pathway in a manner inversely proportional to their virulence, suggesting that the rate of complement activation is crucial for the fate of the bacteria in the mouse. The effector mechanism has, however, remained open since Salmonellae survive and multiply in the macrophages of the mouse. We show in this study that although the least virulent O-6,7 Salmonellae multiply in the liver macrophages they are rapidly killed in the peritoneal cavity by the local resident macrophages. Electron microscopy showed a striking morphological feature--a 35 nm thick homogenous electron-dense deposit--on all the bacteria found in association with the macrophages but absent from all non-cell-associated bacteria. A similar precipitate was formed by incubating the bacteria in fresh mouse serum and was dependent on heat-labile serum components and bound anti-C3. The least virulent O-6,7 bacteria acquired this deposit more rapidly and in a lower concentration of serum than the more virulent O-4,12 bacteria consistent with the previously demonstrated difference between these bacteria in their rate of complement activation via the alternative pathway. Preincubation of the O-4,12 bacteria in fresh mouse serum leading to complement deposition on 80% of the bacteria effectively opsonized them for rapid killing in the peritoneal cavity. These data for the first time demonstrate how the rate of complement activation determines the virulence of Salmonellae. PMID:3333794

  16. Activation of the alternative pathway of complement during the acute phase of typical haemolytic uraemic syndrome.

    PubMed

    Ferraris, J R; Ferraris, V; Acquier, A B; Sorroche, P B; Saez, M S; Ginaca, A; Mendez, C F

    2015-07-01

    Haemolytic uraemic syndrome (HUS) is characterized by haemolytic anaemia, thrombocytopenia and acute renal failure. We studied the activation state of classical and alternative pathways of complement during the acute phase of Shiga toxin-associated HUS by performing a prospective study of 18 patients and 17 age-matched healthy controls to evaluate C3, C3c, C4, C4d, Bb and SC5b-9 levels. SC5b-9 levels were increased significantly in all patients at admission compared to healthy and end-stage renal disease controls, but were significantly higher in patients presenting with oliguria compared to those with preserved diuresis. C3 and C4 levels were elevated significantly at admission in the non-oliguric group when compared to controls. No significant differences were found for C4d values, whereas factor Bb was elevated in all patients and significantly higher in oliguric patients when compared to both controls and non-oliguric individuals. A positive and significant association was detected when Bb formation was plotted as a function of plasma SC5b-9 at admission. Bb levels declined rapidly during the first week, with values not significantly different from controls by days 3 and 5 for non-oligurics and oligurics, respectively. Our data demonstrate the activation of the alternative pathway of complement during the acute phase of Stx-associated HUS. This finding suggests that complement activation may represent an important trigger for the cell damage that occurs during the syndrome. PMID:25677399

  17. Complement activity is associated with disease severity in multifocal motor neuropathy

    PubMed Central

    Vlam, Lotte; Cats, Elisabeth A.; Harschnitz, Oliver; Jansen, Marc D.; Piepers, Sanne; Veldink, Jan Herman; Franssen, Hessel; Stork, Abraham C.J.; Heezius, Erik; Rooijakkers, Suzan H.M.; Herpers, Bjorn L.; van Strijp, Jos A.; van den Berg, Leonard H.

    2015-01-01

    Objective: To investigate whether high innate activity of the classical and lectin pathways of complement is associated with multifocal motor neuropathy (MMN) and whether levels of innate complement activity or the potential of anti-GM1 antibodies to activate the complement system correlate with disease severity. Methods: We performed a case-control study including 79 patients with MMN and 79 matched healthy controls. Muscle weakness was documented with Medical Research Council scale sum score and axonal loss with nerve conduction studies. Activity of the classical and lectin pathways of complement was assessed by ELISA. We also determined serum mannose-binding lectin (MBL) concentrations and polymorphisms in the MBL gene (MBL2) and quantified complement-activating properties of anti-GM1 IgM antibodies by ELISA. Results: Activity of the classical and lectin pathways, MBL2 genotypes, and serum MBL concentrations did not differ between patients and controls. Complement activation by anti-GM1 IgM antibodies was exclusively mediated through the classical pathway and correlated with antibody titers (p < 0.001). Logistic regression analysis showed that both high innate activity of the classical pathway of complement and high complement-activating capacity of anti-GM1 IgM antibodies were significantly associated with more severe muscle weakness and axonal loss. Conclusion: High innate activity of the classical pathway of complement and efficient complement-activating properties of anti-GM1 IgM antibodies are determinants of disease severity in patients with MMN. These findings underline the importance of anti-GM1 antibody–mediated complement activation in the pathogenesis and clinical course of MMN. PMID:26161430

  18. Identification of peptidic inhibitors of the alternative complement pathway based on Staphylococcus aureus SCIN proteins.

    PubMed

    Summers, Brady J; Garcia, Brandon L; Woehl, Jordan L; Ramyar, Kasra X; Yao, Xiaolan; Geisbrecht, Brian V

    2015-10-01

    The complement system plays a central role in a number of human inflammatory diseases, and there is a significant need for development of complement-directed therapies. The discovery of an arsenal of anti-complement proteins secreted by the pathogen Staphylococcus aureus brought with it the potential for harnessing the powerful inhibitory properties of these molecules. One such family of inhibitors, the SCINs, interact with a functional "hot-spot" on the surface of C3b. SCINs not only stabilize an inactive form of the alternative pathway (AP) C3 convertase (C3bBb), but also overlap the C3b binding site of complement factors B and H. Here we determined that a conserved Arg residue in SCINs is critical for function of full-length SCIN proteins. Despite this, we also found SCIN-specific differences in the contributions of other residues found at the C3b contact site, which suggested that a more diverse repertoire of residues might be able to recognize this region of C3b. To investigate this possibility, we conducted a phage display screen aimed at identifying SCIN-competitive 12-mer peptides. In total, seven unique sequences were identified and all exhibited direct C3b binding. A subset of these specifically inhibited the AP in assays of complement function. The mechanism of AP inhibition by these peptides was probed through surface plasmon resonance approaches, which revealed that six of the seven peptides disrupted C3bBb formation by interfering with factor B/C3b binding. To our knowledge this study has identified the first small molecules that retain inhibitory properties of larger staphylococcal immune evasion proteins. PMID:26052070

  19. Alternative Complement Pathway Activation Products in Urine and Kidneys of Patients with ANCA-Associated GN

    PubMed Central

    Gou, Shen-Ju; Yuan, Jun; Wang, Chen; Zhao, Ming-Hui

    2013-01-01

    Summary Background and objectives Previous study revealed that complement activation products of the alternative pathway could be detected in renal specimens of human ANCA-associated vasculitis. The current study aimed to investigate the clinical and pathologic significance of complement activation products in the urine and kidneys of patients with ANCA-associated vasculitis. Design, setting, participants, & measurements Renal biopsy specimens from 29 patients with ANCA-associated vasculitis diagnosed at Peking University First Hospital from January of 2008 to December of 2010 were randomly collected. Urine samples from 27 of 29 patients in active stage and 22 ANCA-associated vasculitis patients in complete remission who were independent of the above-mentioned 29 patients were collected. Urine samples from 28 patients with lupus nephritis and 25 healthy individuals were also collected. The renal deposition of Bb, C3d, and C5b-9 were detected by immunohistochemistry. The urinary levels of Bb, C3a, C5a, and soluble C5b-9 were determined by ELISA. Results The deposition, measured by the mean optical density of Bb, which is an alternative complement pathway marker, in glomeruli correlated with the proportion of total crescents (r=0.50, P=0.006), the extent of interstitial infiltrate (r=0.59, P=0.001), interstitial fibrosis (r=0.45, P=0.01), and tubular atrophy (r=0.55, P=0.002), whereas it correlated inversely with the proportion of normal glomeruli (r=?0.49, P=0.008). The urinary levels of Bb, C3a, C5a, and soluble C5b-9 were all significantly higher in active compared with remission stage. The urinary levels of Bb in patients with active ANCA-associated vasculitis correlated with the serum creatinine (r=0.56, P=0.002) and correlated inversely with the proportion of normal glomeruli in renal specimens (r=?0.49, P=0.009). Conclusions The present study provides additional evidence that complement activation through the alternative pathway occurred in the development of ANCA-associated vasculitis. The renal deposition of Bb and urinary Bb levels were associated with the severity of renal injury. PMID:24115193

  20. A zebrafish model for uremic toxicity: role of the complement pathway.

    PubMed

    Berman, Nathaniel; Lectura, Melisa; Thurman, Joshua M; Reinecke, James; Raff, Amanda C; Melamed, Michal L; Quan, Zhe; Evans, Todd; Meyer, Timothy W; Hostetter, Thomas H

    2013-01-01

    Many organic solutes accumulate in end-stage renal disease (ESRD) and some are poorly removed with urea-based prescriptions for hemodialysis. However, their toxicities have been difficult to assess. We have employed an animal model, the zebrafish embryo, to test the toxicity of uremic serum compared to control. Serum was obtained from stable ESRD patients predialysis or from normal subjects. Zebrafish embryos 24 h postfertilization were exposed to experimental media at a water:human serum ratio of 3:1. Those exposed to serum from uremic subjects had significantly reduced survival at 8 h (19 ± 18 vs. 94 ± 6%, p < 0.05, uremic serum vs. control, respectively). Embryos exposed to serum from ESRD subjects fractionated at 50 kDa showed significantly greater toxicity with the larger molecular weight fraction (83 ± 11 vs. 7 ± 17% survival, p < 0.05, <50 vs. >50 kDa, respectively). Heating serum abrogated its toxicity. EDTA, a potent inhibitor of complement by virtue of calcium chelation, reduced the toxicity of uremic serum compared to untreated uremic serum (96 ± 5 vs. 28 ± 20% survival, p < 0.016, chelated vs. nonchelated serum, respectively). Anti-factor B, a specific inhibitor of the alternative complement pathway, reduced the toxicity of uremic serum, compared to untreated uremic serum (98 ± 6 vs. 3 ± 9% survival, p < 0.016, anti-factor B treated vs. nontreated, respectively). Uremic serum is thus more toxic to zebrafish embryos than normal serum. Furthermore, this toxicity is associated with a fraction of large size, is inactivated by heat, and is reduced by both specific and nonspecific inhibitors of complement activation. Together these data lend support to the hypothesis that at least some uremic toxicities may be mediated by complement. PMID:23689420

  1. Peptide Inhibitor of Complement C1 (PIC1) Rapidly Inhibits Complement Activation after Intravascular Injection in Rats

    PubMed Central

    Sharp, Julia A.; Hair, Pamela S.; Pallera, Haree K.; Kumar, Parvathi S.; Mauriello, Clifford T.; Nyalwidhe, Julius O.; Phelps, Cody A.; Park, Dalnam; Thielens, Nicole M.; Pascal, Stephen M.; Chen, Waldon; Duffy, Diane M.; Lattanzio, Frank A.; Cunnion, Kenji M.; Krishna, Neel K.

    2015-01-01

    The complement system has been increasingly recognized to play a pivotal role in a variety of inflammatory and autoimmune diseases. Consequently, therapeutic modulators of the classical, lectin and alternative pathways of the complement system are currently in pre-clinical and clinical development. Our laboratory has identified a peptide that specifically inhibits the classical and lectin pathways of complement and is referred to as Peptide Inhibitor of Complement C1 (PIC1). In this study, we determined that the lead PIC1 variant demonstrates a salt-dependent binding to C1q, the initiator molecule of the classical pathway. Additionally, this peptide bound to the lectin pathway initiator molecule MBL as well as the ficolins H, M and L, suggesting a common mechanism of PIC1 inhibitory activity occurs via binding to the collagen-like tails of these collectin molecules. We further analyzed the effect of arginine and glutamic acid residue substitution on the complement inhibitory activity of our lead derivative in a hemolytic assay and found that the original sequence demonstrated superior inhibitory activity. To improve upon the solubility of the lead derivative, a pegylated, water soluble variant was developed, structurally characterized and demonstrated to inhibit complement activation in mouse plasma, as well as rat, non-human primate and human serum in vitro. After intravenous injection in rats, the pegylated derivative inhibited complement activation in the blood by 90% after 30 seconds, demonstrating extremely rapid function. Additionally, no adverse toxicological effects were observed in limited testing. Together these results show that PIC1 rapidly inhibits classical complement activation in vitro and in vivo and is functional for a variety of animal species, suggesting its utility in animal models of classical complement-mediated diseases. PMID:26196285

  2. Kidney Disease Caused by Dysregulation of the Complement Alternative Pathway: An Etiologic Approach.

    PubMed

    De Vriese, An S; Sethi, Sanjeev; Van Praet, Jens; Nath, Karl A; Fervenza, Fernando C

    2015-12-01

    Kidney diseases caused by genetic or acquired dysregulation of the complement alternative pathway (AP) are traditionally classified on the basis of clinical presentation (atypical hemolytic uremic syndrome as thrombotic microangiopathy), biopsy appearance (dense deposit disease and C3 GN), or clinical course (atypical postinfectious GN). Each is characterized by an inappropriate activation of the AP, eventuating in renal damage. The clinical diversity of these disorders highlights important differences in the triggers, the sites and intensity of involvement, and the outcome of the AP dysregulation. Nevertheless, we contend that these diseases should be grouped as disorders of the AP and classified on an etiologic basis. In this review, we define different pathophysiologic categories of AP dysfunction. The precise identification of the underlying abnormality is the key to predict the response to immune suppression, plasma infusion, and complement-inhibitory drugs and the outcome after transplantation. In a patient with presumed dysregulation of the AP, the collaboration of the clinician, the renal pathologist, and the biochemical and genetic laboratory is very much encouraged, because this enables the elucidation of both the underlying pathogenesis and the optimal therapeutic approach. PMID:26185203

  3. Isolation and characterization of rabbit properdin of the alternative complement pathway.

    PubMed

    Nakano, Y; Matsuda, T; Sakamoto, T; Tomita, M

    1986-06-10

    Rabbit factor P, which is involved in stabilizing the labile C3 convertase of the alternative complement pathway, was isolated from rabbit serum by a simple two-step procedure: polyethylene glycol precipitation and QAE-Sephadex A-50 column chromatography. The chemical properties, and functional activities of the rabbit P were very similar to those of human P, except that there were slight differences in the SDS-PAGE patterns of limited tryptic digests and in the amino terminal sequences. The molecular weights were estimated to be 58 000 for rabbit P and 59 000 for human P on SDS-PAGE under reducing conditions. The amino terminal 36 residues of rabbit P showed 78% homology to the equivalent region of human P. PMID:3635564

  4. Pseudomonas aeruginosa Uses Dihydrolipoamide Dehydrogenase (Lpd) to Bind to the Human Terminal Pathway Regulators Vitronectin and Clusterin to Inhibit Terminal Pathway Complement Attack

    PubMed Central

    Hallström, Teresia; Uhde, Melanie; Singh, Birendra; Skerka, Christine; Riesbeck, Kristian; Zipfel, Peter F.

    2015-01-01

    The opportunistic human pathogen Pseudomonas aeruginosa controls host innate immune and complement attack. Here we identify Dihydrolipoamide dehydrogenase (Lpd), a 57 kDa moonlighting protein, as the first P. aeruginosa protein that binds the two human terminal pathway inhibitors vitronectin and clusterin. Both human regulators when bound to the bacterium inhibited effector function of the terminal complement, blocked C5b-9 deposition and protected the bacterium from complement damage. P. aeruginosa when challenged with complement active human serum depleted from vitronectin was severely damaged and bacterial survival was reduced by over 50%. Similarly, when in human serum clusterin was blocked by a mAb, bacterial survival was reduced by 44%. Thus, demonstrating that Pseudomonas benefits from attachment of each human regulator and controls complement attack. The Lpd binding site in vitronectin was localized to the C-terminal region, i.e. to residues 354–363. Thus, Lpd of P. aeruginosa is a surface exposed moonlighting protein that binds two human terminal pathway inhibitors, vitronectin and clusterin and each human inhibitor when attached protected the bacterial pathogen from the action of the terminal complement pathway. Our results showed insights into the important function of Lpd as a complement regulator binding protein that might play an important role in virulence of P. aeruginosa. PMID:26368530

  5. Design and development of TT30, a novel C3d-targeted C3/C5 convertase inhibitor for treatment of human complement alternative pathway–mediated diseases

    PubMed Central

    Storek, Michael; Mazsaroff, Istvan; Risitano, Antonio M.; Lundberg, Ante S.; Horvath, Christopher J.; Holers, V. Michael

    2011-01-01

    To selectively modulate human complement alternative pathway (CAP) activity implicated in a wide range of acute and chronic inflammatory conditions and to provide local cell surface and tissue-based inhibition of complement-induced damage, we developed TT30, a novel therapeutic fusion protein linking the human complement receptor type 2 (CR2/CD21) C3 fragment (C3frag = iC3b, C3dg, C3d)-binding domain with the CAP inhibitory domain of human factor H (fH). TT30 efficiently blocks ex vivo CAP-dependent C3frag accumulation on activated surfaces, membrane attack complex (MAC) formation and hemolysis of RBCs in a CR2-dependent manner, and with a ? 150-fold potency gain over fH, without interference of C3 activation or MAC formation through the classic and lectin pathways. TT30 protects RBCs from hemolysis and remains bound and detectable for at least 24 hours. TT30 selectively inhibits CAP in cynomolgus monkeys and is bioavailable after subcutaneous injection. Using a unique combination of targeting and effector domains, TT30 controls cell surface CAP activation and has substantial potential utility for the treatment of human CAP-mediated diseases. PMID:21860027

  6. Legume Lectins

    PubMed Central

    Hankins, Charles N.; Kindinger, Juanita I.; Shannon, Leland M.

    1979-01-01

    A number of well characterized legume lectins including the enzymic lectin from Vigna radiata were examined for immunological relatedness. The immunological cross-reactions observed indicate that most of the legume lectins, including Vigna lectin, are evolutionarily closely related proteins. The possibility that these proteins are homologs with enzymic functions is discussed. Images PMID:16660894

  7. Mechanisms involved in antibody- and complement-mediated allograft rejection.

    PubMed

    Wasowska, Barbara A

    2010-07-01

    Antibody-mediated rejection has become critical clinically because this form of rejection is usually unresponsive to conventional anti-rejection therapy, and therefore, it has been recognized as a major cause of allograft loss. Our group developed experimental animal models of vascularized organ transplantation to study pathogenesis of antibody- and complement-mediated endothelial cell injury leading to graft rejection. In this review, we discuss mechanisms of antibody-mediated graft rejection resulting from activation of complement by C1q- and MBL (mannose-binding lectin)-dependent pathways and interactions with a variety of effector cells, including macrophages and monocytes through Fcgamma receptors and complement receptors. PMID:20135240

  8. Complement System Part I – Molecular Mechanisms of Activation and Regulation

    PubMed Central

    Merle, Nicolas S.; Church, Sarah Elizabeth; Fremeaux-Bacchi, Veronique; Roumenina, Lubka T.

    2015-01-01

    Complement is a complex innate immune surveillance system, playing a key role in defense against pathogens and in host homeostasis. The complement system is initiated by conformational changes in recognition molecular complexes upon sensing danger signals. The subsequent cascade of enzymatic reactions is tightly regulated to assure that complement is activated only at specific locations requiring defense against pathogens, thus avoiding host tissue damage. Here, we discuss the recent advances describing the molecular and structural basis of activation and regulation of the complement pathways and their implication on physiology and pathology. This article will review the mechanisms of activation of alternative, classical, and lectin pathways, the formation of C3 and C5 convertases, the action of anaphylatoxins, and the membrane-attack-complex. We will also discuss the importance of structure–function relationships using the example of atypical hemolytic uremic syndrome. Lastly, we will discuss the development and benefits of therapies using complement inhibitors. PMID:26082779

  9. Complement Defects in Patients with Chronic Rhinosinusitis

    PubMed Central

    Gaunsbaek, Maria Q.; Lange, Bibi; Kjeldsen, Anette D.; Svane-Knudsen, Viggo; Skjoedt, Karsten; Henriksen, Maiken L.; Nielsen, Christian; Palarasah, Yaseelan; Hansen, Soren

    2012-01-01

    The complement system is an important part of our immune system, and complement defects lead generally to increased susceptibility to infections and autoimmune diseases. We have studied the role of complement activity in relation with chronic rhinosinusitis (CRS), and more specifically studied whether complement defects collectively predispose individuals for CRS or affect CRS severity. The participants comprised 87 CRS patients randomly selected from the general population, and a control group of 150 healthy blood donors. The CRS patients were diagnosed according to the European Position Paper on Rhinosinusitis and nasal Polyps criteria, and severity was evaluated by the Sino-nasal Outcome Test-22. Serum samples were analysed by ELISA for activity of the respective pathways of complement, and subsequently for serum levels of relevant components. We found that the frequency of complement defects was significantly higher among CRS patients than among healthy control subjects. A majority of Mannan-binding lectin deficient CRS patients was observed. The presence of complement defects had no influence on the severity of subjective symptoms. Our studies show that defects in the complement system collectively may play an immunological role related to the development of CRS. However, an association between severity of symptoms and presence of complement defects could not be demonstrated. PMID:23144819

  10. Inefficient Complement System Clearance of Trypanosoma cruzi Metacyclic Trypomastigotes Enables Resistant Strains to Invade Eukaryotic Cells

    PubMed Central

    Cestari, Igor; Ramirez, Marcel I.

    2010-01-01

    The complement system is the main arm of the vertebrate innate immune system against pathogen infection. For the protozoan Trypanosoma cruzi, the causative agent of Chagas disease, subverting the complement system and invading the host cells is crucial to succeed in infection. However, little attention has focused on whether the complement system can effectively control T. cruzi infection. To address this question, we decided to analyse: 1) which complement pathways are activated by T. cruzi using strains isolated from different hosts, 2) the capacity of these strains to resist the complement-mediated killing at nearly physiological conditions, and 3) whether the complement system could limit or control T. cruzi invasion of eukaryotic cells. The complement activating molecules C1q, C3, mannan-binding lectin and ficolins bound to all strains analysed; however, C3b and C4b deposition assays revealed that T. cruzi activates mainly the lectin and alternative complement pathways in non-immune human serum. Strikingly, we detected that metacyclic trypomastigotes of some T. cruzi strains were highly susceptible to complement-mediated killing in non-immune serum, while other strains were resistant. Furthermore, the rate of parasite invasion in eukaryotic cells was decreased by non-immune serum. Altogether, these results establish that the complement system recognizes T. cruzi metacyclic trypomastigotes, resulting in killing of susceptible strains. The complement system, therefore, acts as a physiological barrier which resistant strains have to evade for successful host infection. PMID:20300530

  11. Characterization of a Factor H Mutation That Perturbs the Alternative Pathway of Complement in a Family with Membranoproliferative GN

    PubMed Central

    Wong, Edwin K.S.; Anderson, Holly E.; Herbert, Andrew P.; Challis, Rachel C.; Brown, Paul; Reis, Geisilaine S.; Tellez, James O.; Strain, Lisa; Fluck, Nicholas; Humphrey, Ann; Macleod, Alison; Richards, Anna; Ahlert, Daniel; Santibanez-Koref, Mauro; Barlow, Paul N.; Marchbank, Kevin J.; Harris, Claire L.; Goodship, Timothy H.J.

    2014-01-01

    Complement C3 activation is a characteristic finding in membranoproliferative GN (MPGN). This activation can be caused by immune complex deposition or an acquired or inherited defect in complement regulation. Deficiency of complement factor H has long been associated with MPGN. More recently, heterozygous genetic variants have been reported in sporadic cases of MPGN, although their functional significance has not been assessed. We describe a family with MPGN and acquired partial lipodystrophy. Although C3 nephritic factor was shown in family members with acquired partial lipodystrophy, it did not segregate with the renal phenotype. Genetic analysis revealed a novel heterozygous mutation in complement factor H (R83S) in addition to known risk polymorphisms carried by individuals with MPGN. Patients with MPGN had normal levels of factor H, and structural analysis of the mutant revealed only subtle alterations. However, functional analysis revealed profoundly reduced C3b binding, cofactor activity, and decay accelerating activity leading to loss of regulation of the alternative pathway. In summary, this family showed a confluence of common and rare functionally significant genetic risk factors causing disease. Data from our analysis of these factors highlight the role of the alternative pathway of complement in MPGN. PMID:24722444

  12. Molecules Great and Small: The Complement System.

    PubMed

    Mathern, Douglas R; Heeger, Peter S

    2015-09-01

    The complement cascade, traditionally considered an effector arm of innate immunity required for host defense against pathogens, is now recognized as a crucial pathogenic mediator of various kidney diseases. Complement components produced by the liver and circulating in the plasma undergo activation through the classical and/or mannose-binding lectin pathways to mediate anti-HLA antibody-initiated kidney transplant rejection and autoantibody-initiated GN, the latter including membranous glomerulopathy, antiglomerular basement membrane disease, and lupus nephritis. Inherited and/or acquired abnormalities of complement regulators, which requisitely limit restraint on alternative pathway complement activation, contribute to the pathogenesis of the C3 nephropathies and atypical hemolytic uremic syndrome. Increasing evidence links complement produced by endothelial cells and/or tubular cells to the pathogenesis of kidney ischemia-reperfusion injury and progressive kidney fibrosis. Data emerging since the mid-2000s additionally show that immune cells, including T cells and antigen-presenting cells, produce alternative pathway complement components during cognate interactions. The subsequent local complement activation yields production of the anaphylatoxins C3a and C5a, which bind to their respective receptors (C3aR and C5aR) on both partners to augment effector T-cell proliferation and survival, while simultaneously inhibiting regulatory T-cell induction and function. This immune cell-derived complement enhances pathogenic alloreactive T-cell immunity that results in transplant rejection and likely contributes to the pathogenesis of other T cell-mediated kidney diseases. C5a/C5aR ligations on neutrophils have additionally been shown to contribute to vascular inflammation in models of ANCA-mediated renal vasculitis. New translational immunology efforts along with the development of pharmacologic agents that block human complement components and receptors now permit testing of the intriguing concept that targeting complement in patients with an assortment of kidney diseases has the potential to abrogate disease progression and improve patient health. PMID:25568220

  13. The indoleamine 2,3-dioxygenase pathway controls complement-dependent enhancement of chemo-radiation therapy against murine glioblastoma

    PubMed Central

    2014-01-01

    Background Indoleamine 2,3-dioxygenase (IDO) is an enzyme with immune-suppressive properties that is commonly exploited by tumors to evade immune destruction. Anti-tumor T cell responses can be initiated in solid tumors, but are immediately suppressed by compensatory upregulation of immunological checkpoints, including IDO. In addition to these known effects on the adaptive immune system, we previously showed widespread, T cell-dependent complement deposition during allogeneic fetal rejection upon maternal treatment with IDO-blockade. We hypothesized that IDO protects glioblastoma from the full effects of chemo-radiation therapy by preventing vascular activation and complement-dependent tumor destruction. Methods To test this hypothesis, we utilized a syngeneic orthotopic glioblastoma model in which GL261 glioblastoma tumor cells were stereotactically implanted into the right frontal lobes of syngeneic mice. These mice were treated with IDO-blocking drugs in combination with chemotherapy and radiation therapy. Results Pharmacologic inhibition of IDO synergized with chemo-radiation therapy to prolong survival in mice bearing intracranial glioblastoma tumors. We now show that pharmacologic or genetic inhibition of IDO allowed chemo-radiation to trigger widespread complement deposition at sites of tumor growth. Chemotherapy treatment alone resulted in collections of perivascular leukocytes within tumors, but no complement deposition. Adding IDO-blockade led to upregulation of VCAM-1 on vascular endothelium within the tumor microenvironment, and further adding radiation in the presence of IDO-blockade led to widespread deposition of complement. Mice genetically deficient in complement component C3 lost all of the synergistic effects of IDO-blockade on chemo-radiation-induced survival. Conclusions Together these findings identify a novel mechanistic link between IDO and complement, and implicate complement as a major downstream effector mechanism for the beneficial effect of IDO-blockade after chemo-radiation therapy. We speculate that this represents a fundamental pathway by which the tumor regulates intratumoral vascular activation and protects itself from immune-mediated tumor destruction. PMID:25054064

  14. Down-Regulation of Complement Receptors on the Surface of Host Monocyte Even as In Vitro Complement Pathway Blocking Interferes in Dengue Infection

    PubMed Central

    Marinho, Cintia Ferreira; Azeredo, Elzinandes Leal; Torrentes-Carvalho, Amanda; Marins-Dos-Santos, Alessandro; Kubelka, Claire Fernandes; de Souza, Luiz José; Cunha, Rivaldo Venâncio; de-Oliveira-Pinto, Luzia Maria

    2014-01-01

    In dengue virus (DENV) infection, complement system (CS) activation appears to have protective and pathogenic effects. In severe dengue fever (DF), the levels of DENV non-structural-1 protein and of the products of complement activation, including C3a, C5a and SC5b-9, are higher before vascular leakage occurs, supporting the hypothesis that complement activation contributes to unfavourable outcomes. The clinical manifestations of DF range from asymptomatic to severe and even fatal. Here, we aimed to characterise CS by their receptors or activation product, in vivo in DF patients and in vitro by DENV-2 stimulation on monocytes. In comparison with healthy controls, DF patients showed lower expression of CR3 (CD11b), CR4 (CD11c) and, CD59 on monocytes. The DF patients who were high producers of SC5b-9 were also those that showed more pronounced bleeding or vascular leakage. Those findings encouraged us to investigate the role of CS in vitro, using monocytes isolated from healthy subjects. Prior blocking with CR3 alone (CD11b) or CR3 (CD11b/CD18) reduced viral infection, as quantified by the levels of intracellular viral antigen expression and soluble DENV non-structural viral protein. However, we found that CR3 alone (CD11b) or CR3 (CD11b/CD18) blocking did not influence major histocompatibility complex presentation neither active caspase-1 on monocytes, thus probably ruling out inflammasome-related mechanisms. Although it did impair the secretion of tumour necrosis factor alpha and interferon alpha. Our data provide strategies of blocking CR3 (CD11b) pathways could have implications for the treatment of viral infection by antiviral-related mechanisms. PMID:25061945

  15. The alternative complement pathway control protein H binds to immune complexes and serves their detection

    SciTech Connect

    Nydegger, U.E.; Corvetta, A.; Spaeth, P.J.; Spycher, M.

    1983-01-01

    During solubilization of immune complexes C3b becomes fixed to the immunoglobulin part and serves as a receptor for the alternative complement pathway control protein H. The H-C3b immune complex interaction can be made detectable using 4% polyethyleneglycol to separate free from bound /sup 125/I-H. Tetanus toxoid (Te)/anti-Te complexes kept soluble with fresh serum and containing 125 IU of specific antibody bound 18% of /sup 125/I-H; when fresh serum was chelated with 10 mM EDTA, /sup 125/I-H binding was only 5%. On sucrose density gradients, the H-binding material sedimented in the range of 12 to 30 S. In 36 serum samples from rheumatoid arthritis (RA) patients and in 12 serum samples from patients with systemic lupus erythematosus (SLE), /sup 125/I-H binding was significantly elevated to 9.5 +/- 4.7% (mean +/- 1 SD) and 13.3 +/- 5.6%, respectively, while /sup 125/I-H binding by 36 normal human sera was 4 +/- 2%. RA samples (17/36, 47%) and SLE samples (9/12, 75%) had H-binding values increased by more than 2 SD above the normal mean. The serum samples were also assessed for conglutinin- and C1q-binding activities; a significant correlation between H and C1q binding was observed (P less than 0.001); there was no correlation between H and conglutinin binding. Although binding to immune complexes through its interaction with C3b, H clearly detects a population of complexes other than conglutinin, thus expanding the possibilities of further characterizing pathological complexes.

  16. Molecular mechanism of anticancer effect of Sclerotium rolfsii lectin in HT29 cells involves differential expression of genes associated with multiple signaling pathways: A microarray analysis.

    PubMed

    Barkeer, Srikanth; Guha, Nilanjan; Hothpet, Vishwanathreddy; Saligrama Adavigowda, Deepak; Hegde, Prajna; Padmanaban, Arunkumar; Yu, Lu-Gang; Swamy, Bale M; Inamdar, Shashikala R

    2015-12-01

    Sclerotium rolfsii lectin (SRL) is a lectin isolated from fungus S. rolfsii and has high binding specificity toward the oncofetal Thomsen-Friedenreich carbohydrate antigen (Gal?1-3GalNAc-?-O-Ser/Thr, T or TF), which is expressed in more than 90% of human cancers. Our previous studies have shown that binding of SRL to human colon, breast and ovarian cancer cells induces cell apoptosis in vitro and suppresses tumor growth in vivo. This study investigated the SRL-mediated cell signaling in human colon cancer HT29 cells by mRNA and miRNA microarrays. It was found that SRL treatment results in altered expression of several hundred molecules including mitogen-activated protein kinase (MAPK) and c-JUN-associated, apoptosis-associated and cell cycle and DNA replication-associated signaling molecules. Pathway analysis using GeneSpring 12.6.1 revealed that SRL treatment induces changes of MAPK and c-JUN-associated signaling pathways as early as 2 h while changes of cell cycle, DNA replication and apoptosis pathways were significantly affected only after 24 h. A significant change of cell miRNA expression was also observed after 12 h treatment of the cells with SRL. These changes were further validated by quantitative real time polymerase chain reaction and immunoblotting. This study thus suggests that the presence of SRL affects multiple signaling pathways in cancer cells with early effects on cell proliferation pathways associated with MAPK and c-JUN, followed by miRNA-associated cell activity and apoptosis. This provides insight information into the molecular mechanism of the anticancer activity of this fungal lectin. PMID:26347523

  17. Dissecting the complement pathway in hepatic injury and regeneration with a novel protective strategy

    PubMed Central

    Marshall, Keely M.; Zhong, Zhi; Atkinson, Carl

    2014-01-01

    Liver resection is commonly performed under ischemic conditions, resulting in two types of insult to the remnant liver: ischemia reperfusion injury (IRI) and loss of liver mass. Complement inhibition is recognized as a potential therapeutic modality for IRI, but early complement activation products are also essential for liver regeneration. We describe a novel site-targeted murine complement inhibitor, CR2-CD59, which specifically inhibits the terminal membrane attack complex (MAC), and we use this protein to investigate the complement-dependent balance between liver injury and regeneration in a clinical setting of pharmacological inhibition. CR2-CD59 did not impact in vivo generation of C3 and C5 activation products but was as effective as the C3 activation inhibitor CR2-Crry at ameliorating hepatic IRI, indicating that the MAC is the principle mediator of hepatic IRI. Furthermore, unlike C3 or C5 inhibition, CR2-CD59 was not only protective but significantly enhanced hepatocyte proliferation after partial hepatectomy, including when combined with ischemia and reperfusion. Remarkably, CR2-CD59 also enhanced regeneration after 90% hepatectomy and improved long-term survival from 0 to 70%. CR2-CD59 functioned by increasing hepatic TNF and IL-6 levels with associated STAT3 and Akt activation, and by preventing mitochondrial depolarization and allowing recovery of ATP stores. PMID:25113972

  18. Impact of Mannose-Binding Lectin Deficiency on Radiocontrast-Induced Renal Dysfunction

    PubMed Central

    Osthoff, Michael; Trendelenburg, Marten

    2013-01-01

    Contrast-induced nephropathy (CIN) is the third leading cause of acute renal failure in hospitalized patients. Endothelial dysfunction, renal medullary ischemia, and tubular toxicity are regarded as the most important factors in the pathogenesis of CIN. Mannose-binding lectin (MBL), a pattern recognition protein of the lectin pathway of complement, has been found to aggravate and mediate tissue damage during experimental renal ischemia/reperfusion (I/R) injury which was alleviated by inhibition with C1 inhibitor, a potent MBL, and lectin pathway inhibitor. In this paper, we highlight the potential role of MBL in the pathogenesis of human CIN. In experimental I/R models, MBL was previously found to induce tubular cell death independent of the complement system. In addition, after binding to vascular endothelial cells, MBL and its associated serine proteases were able to trigger a proinflammatory reaction and contribute to endothelial dysfunction. In humans, urinary MBL was increased after administration of contrast media and in individuals with CIN. Moreover, individuals with normal/high MBL levels were at increased risk to develop radiocontrast-induced renal dysfunction. Hence, MBL and the lectin pathway seem to be a promising target given that a licensed, powerful, human recombinant inhibitor exits to be added to the scarce armamentarium currently available for prophylaxis of CIN. PMID:24386641

  19. Genetic Association of the Porcine C9 Complement Component with Hemolytic Complement Activity

    PubMed Central

    Khoa, D. V. A.; Wimmers, K.

    2015-01-01

    The complement system is a part of the natural immune regulation mechanism against invading pathogens. Complement activation from three different pathways (classical, lectin, and alternative) leads to the formation of C5-convertase, an enzyme for cleavage of C5 into C5a and C5b, followed by C6, C7, C8, and C9 in membrane attack complex. The C9 is the last complement component of the terminal lytic pathway, which plays an important role in lysis of the target cells depending on its self-polymerization to form transmembrane channels. To address the association of C9 with traits related to disease resistance, the complete porcine C9 cDNA was comparatively sequenced to detect single nucleotide polymorphisms (SNPs) in pigs of the breeds Hampshire (HS), Duroc (DU), Berlin miniature pig (BMP), German Landrace (LR), Pietrain (PIE), and Muong Khuong (Vietnamese potbelly pig). Genotyping was performed in 417 F2 animals of a resource population (DUMI: DU×BMP) that were vaccinated with Mycoplasma hyopneumoniae, Aujeszky diseases virus and porcine respiratory and reproductive syndrome virus at 6, 14 and 16 weeks of age, respectively. Two SNPs were detected within the third exon. One of them has an amino acid substitution. The European porcine breeds (LR and PIE) show higher allele frequency of these SNPs than Vietnamese porcine breed (MK). Association of the substitution SNP with hemolytic complement activity indicated statistically significant differences between genotypes in the classical pathway but not in the alternative pathway. The interactions between eight time points of measurement of complement activity before and after vaccinations and genotypes were significantly different. The difference in hemolytic complement activity in the both pathways depends on genotype, kind of vaccine, age and the interaction to the other complement components. These results promote the porcine C9 (pC9) as a candidate gene to improve general animal health in the future. PMID:26194222

  20. Genetic Association of the Porcine C9 Complement Component with Hemolytic Complement Activity.

    PubMed

    Khoa, D V A; Wimmers, K

    2015-09-01

    The complement system is a part of the natural immune regulation mechanism against invading pathogens. Complement activation from three different pathways (classical, lectin, and alternative) leads to the formation of C5-convertase, an enzyme for cleavage of C5 into C5a and C5b, followed by C6, C7, C8, and C9 in membrane attack complex. The C9 is the last complement component of the terminal lytic pathway, which plays an important role in lysis of the target cells depending on its self-polymerization to form transmembrane channels. To address the association of C9 with traits related to disease resistance, the complete porcine C9 cDNA was comparatively sequenced to detect single nucleotide polymorphisms (SNPs) in pigs of the breeds Hampshire (HS), Duroc (DU), Berlin miniature pig (BMP), German Landrace (LR), Pietrain (PIE), and Muong Khuong (Vietnamese potbelly pig). Genotyping was performed in 417 F2 animals of a resource population (DUMI: DU×BMP) that were vaccinated with Mycoplasma hyopneumoniae, Aujeszky diseases virus and porcine respiratory and reproductive syndrome virus at 6, 14 and 16 weeks of age, respectively. Two SNPs were detected within the third exon. One of them has an amino acid substitution. The European porcine breeds (LR and PIE) show higher allele frequency of these SNPs than Vietnamese porcine breed (MK). Association of the substitution SNP with hemolytic complement activity indicated statistically significant differences between genotypes in the classical pathway but not in the alternative pathway. The interactions between eight time points of measurement of complement activity before and after vaccinations and genotypes were significantly different. The difference in hemolytic complement activity in the both pathways depends on genotype, kind of vaccine, age and the interaction to the other complement components. These results promote the porcine C9 (pC9) as a candidate gene to improve general animal health in the future. PMID:26194222

  1. Activation of complement by Schistosoma mansoni schistosomula: killing of parasites by the alternative pathway and requirement of IgG for classical pathway activation.

    PubMed

    Santoro, F; Lachmann, P J; Capron, A; Capron, M

    1979-10-01

    Living Schistosoma mansoni schistosomula incubated with normal chicken, guinea pig, human, and monkey sera were killed after 4 hr contact at 37 degrees C. The following data indicate that this action is dependent on the activation of the alternative complement pathway (AP): a) the inactivity of RB, RD, and zymosan-treated serum against schistosomula; b) the partial activity of RD restored in FD; c) the full effect of the C4-deficient guinea pig, C2-deficient human, and the agammaglobulinemic human sera; d) the consumption of both the AP and FB after the incubation of NHS with schistosomula; e) the detection of C3d breakdown product during the contact of the C2-deficient human serum with these young parasites. Killing by serum was decreased as the immature schistosomes developed and was completely absent against 4-day-old lung schistosomula (LS). In other experiments, it was demonstrated that schistosomula, in the presence of IgG, were able to initiate complement activation also through the classical pathway (CP). However, the CP does not appear to play a role in the schistosomulicidal activity of complement. The in vivo relevance of these observations is considered. PMID:113459

  2. Ouabain rescues rat nephrogenesis during intrauterine growth restriction by regulating the complement and coagulation cascades and calcium signaling pathway.

    PubMed

    Chen, L; Yue, J; Han, X; Li, J; Hu, Y

    2016-02-01

    Intrauterine growth restriction (IUGR) is associated with a reduction in the numbers of nephrons in neonates, which increases the risk of hypertension. Our previous study showed that ouabain protects the development of the embryonic kidney during IUGR. To explore this molecular mechanism, IUGR rats were induced by protein and calorie restriction throughout pregnancy, and ouabain was delivered using a mini osmotic pump. RNA sequencing technology was used to identify the differentially expressed genes (DEGs) of the embryonic kidneys. DEGs were submitted to the Database for Annotation and Visualization and Integrated Discovery, and gene ontology enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were conducted. Maternal malnutrition significantly reduced fetal weight, but ouabain treatment had no significant effect on body weight. A total of 322 (177 upregulated and 145 downregulated) DEGs were detected between control and the IUGR group. Meanwhile, 318 DEGs were found to be differentially expressed (180 increased and 138 decreased) between the IUGR group and the ouabain-treated group. KEGG pathway analysis indicated that maternal undernutrition mainly disrupts the complement and coagulation cascades and the calcium signaling pathway, which could be protected by ouabain treatment. Taken together, these two biological pathways may play an important role in nephrogenesis, indicating potential novel therapeutic targets against the unfavorable effects of IUGR. PMID:26442628

  3. Shiga Toxin Promotes Podocyte Injury in Experimental Hemolytic Uremic Syndrome via Activation of the Alternative Pathway of Complement

    PubMed Central

    Locatelli, Monica; Buelli, Simona; Pezzotta, Anna; Corna, Daniela; Perico, Luca; Tomasoni, Susanna; Rottoli, Daniela; Rizzo, Paola; Conti, Debora; Thurman, Joshua M.; Remuzzi, Giuseppe; Zoja, Carlamaria

    2014-01-01

    Shiga toxin (Stx)–producing Escherichia coli is the offending agent of postdiarrhea-associated hemolytic uremic syndrome (HUS), a disorder of glomerular ischemic damage and widespread microvascular thrombosis. We previously documented that Stx induces glomerular complement activation, generating C3a responsible for microvascular thrombosis in experimental HUS. Here, we show that the presence of C3 deposits on podocytes is associated with podocyte damage and loss in HUS mice generated by the coinjection of Stx2 and LPS. Because podocyte adhesion to the glomerular basement membrane is mediated by integrins, the relevance of integrin-linked kinase (ILK) signals in podocyte dysfunction was evaluated. Podocyte expression of ILK increased after the injection of Stx2/LPS and preceded the upregulation of Snail and downregulation of nephrin and ?-actinin-4. Factor B deficiency or pretreatment with an inhibitory antibody to factor B protected mice against Stx2/LPS-induced podocyte dysregulation. Similarly, pretreatment with a C3a receptor antagonist limited podocyte loss and changes in ILK, Snail, and ?-actinin-4 expression. In cultured podocytes, treatment with C3a reduced ?-actinin-4 expression and promoted ILK-dependent nuclear expression of Snail and cell motility. These results suggest that Stx-induced activation of the alternative pathway of complement and generation of C3a promotes ILK signaling, leading to podocyte dysfunction and loss in Stx-HUS. PMID:24578132

  4. A Low-Abundance Biofilm Species Orchestrates Inflammatory Periodontal Disease through the Commensal Microbiota and the Complement Pathway

    PubMed Central

    Hajishengallis, George; Liang, Shuang; Payne, Mark A.; Hashim, Ahmed; Jotwani, Ravi; Eskan, Mehmet A.; McIntosh, Megan L.; Alsam, Asil; Kirkwood, Keith L.; Lambris, John D.; Darveau, Richard P.; Curtis, Michael A.

    2011-01-01

    SUMMARY Porphyromonas gingivalis is a low-abundance oral anaerobic bacterium implicated in periodontitis, a polymicrobial inflammatory disease, and the associated systemic conditions. However, the mechanism by which P. gingivalis contributes to inflammation and disease has remained elusive. Here we show that P. gingivalis, at very low colonization levels, triggers changes to the amount and composition of the oral commensal microbiota leading to inflammatory periodontal bone loss. The commensal microbiota and the complement pathway were both required for P. gingivalis-induced bone loss as germ-free mice or conventionally raised C3a and C5a receptor deficient mice did not develop bone loss after inoculation with P. gingivalis. These findings demonstrate that a single, low-abundance species can disrupt host-microbial homeostasis to cause inflammatory disease. The identification and targeting of similar low-abundance pathogens with community-wide impact may be important for treating inflammatory diseases of polymicrobial etiology. PMID:22036469

  5. Visual Pathway Study Using in vivo DTI Tractography to Complement Classical Anatomy

    PubMed Central

    Wu, Wentao; Rigolo, Laura; O’Donnell, Lauren J.; Norton, Isaiah; Shriver, Sargent; Golby, Alexandra J.

    2011-01-01

    Background Knowledge of the individual course of the optic radiations (OR) is important to avoid post-operative visual deficits. Cadaveric studies of the visual pathways are limited because it has not been possible to accurately separate the OR from neighboring tracts and results may not apply to individual patients. Diffusion tensor imaging (DTI) studies may be able to demonstrate the relationships between the OR and neighboring fibers in vivo in individual subjects. Objective To use DTI tractography to study the OR and Meyer’s loop (ML) anatomy in vivo. Methods Ten healthy subjects underwent magnetic resonance imaging with diffusion imaging at 3T. Using a fiducial-based DTI tractography tool (Slicer 3.3), seeds were placed near the lateral geniculate nucleus (LGN) to reconstruct individual visual pathways and neighboring tracts. Projections of the optic radiations onto 3D brain models were shown individually in order to quantify relationships to key landmarks. Results Two patterns of visual pathways were found. The OR ran more commonly deep in the whole superior and middle temporal gyri and superior temporal sulcus. The OR was closely surrounded in all cases by an inferior longitudinal fascicle and a parieto/occipito/temporo-pontine fascicle. The mean left and right distances between the tip of the OR and temporal pole were 39.8± 3.8mm and 40.6±5.7 mm, respectively. Conclusion DTI tractography provides a practical complementary method to study the OR and ML anatomy in vivo, and with reference to individual 3D brain anatomy. PMID:21808220

  6. Role of the complement anaphylatoxin C5a-receptor pathway in atopic dermatitis in mice

    PubMed Central

    DANG, LIN; HE, LEI; WANG, YAN; XIONG, JIKUI; BAI, BINGXUE; LI, YUZHEN

    2015-01-01

    Atopic dermatitis (AD) is a chronic inflammatory skin disease with a genetic background. The C5a-receptor (C5aR) pathway has been reported to be involved in AD; however, the precise pathogenesis remains to be elucidated. In the present study, the contribution of the C5aR pathway to AD in mice was investigated. A BALB/c mouse model of AD was induced by application of 2,4-dinitrochlorobenzene (DNCB) onto hairless dorsal skin. Following DNCB application for 2 weeks, C5aR expression in skin tissue was assessed by reverse transcription quantitative polymerase chain reaction. C5aR expression in skin tissue was significantly increased in mice with AD. In an additional experiment, C5aR antagonist (C5aRA) intracutaneously injected in combination with DNCB treatment. The skin-fold thickness, number of total infiltrating leukocytes and mast cells infiltrating in skin tissue were measured. Interleukin-4 (IL-4) and interferon-? (IFN-?) levels in skin tissue and IL-4, IFN-?, histamine and immunoglobulin E (IgE) levels in serum were measured using ELISA. The skin-fold thickness, numbers of total infiltrating leukocytes and mast cells in skin tissue, as well as levels of IL-4, IFN-?, histamine and IgE were significantly increased in mice with AD. However, simultaneous treatment with C5aRA significantly attenuated increases in skin fold thickness and the numbers of total infiltrating leukocytes and mast cells in skin tissue. Treatment with C5aRA also decreased IL-4 and IFN-? levels in skin tissue, as well as the levels of IL-4, IFN-?, histamine and IgE in the serum. In conclusion, C5aRA inhibited AD in mice, possibly through suppression of the C5aR-mediated cascade action of mast cells. PMID:25650554

  7. ConBr, a lectin from Canavalia brasiliensis seeds, modulates signaling pathways and increases BDNF expression probably via a glycosylated target.

    PubMed

    Rieger, Débora K; Cunha, Rodrigo M S; Lopes, Mark William; Costa, Ana Paula; Budni, Josiani; Rodrigues, Ana Lúcia S; Walz, Roger; Teixeira, Edson H; Nascimento, Kyria S; Cavada, Benildo S; Leal, Rodrigo B

    2014-12-01

    In the central nervous system, many receptors, ion channels and neurotransmitter transporters are glycoproteins, where the glycan chains are modulator elements. Lectins are proteins, which recognize and bind carbohydrate complexes. We have previously shown that ConBr, a lectin purified from Canavalia brasiliensis seeds, produced antidepressant-like effect and blocked hippocampal neurotoxicity induced by quinolinic acid and glutamate. Noteworthy, all these effects occurred in a dependence of its carbohydrate recognition domain. Therefore, the present study was undertaken in order to elucidate intracellular signaling pathways regulated by ConBr that may be potentially associated with the antidepressant and neuroprotective effects previously reported to be dependent on carbohydrate interaction. ConBr (10?µg/site) was injected into the ventricle (i.c.v.) of mice, and the hippocampi were removed 0.5, 1, 3, 6, 8, 12, 18, and 24?h after treatment. Our results showed that in the period of 0.5-3?h, ConBr induced activation of the protein kinases Akt, ERK1, and PKA. Furthermore, the phosphorylation of CREB-Ser133 was stimulated by ConBr (1-6?h), while brain-derived neurotrophic factor (BDNF) mRNA was increased at 12?h and BDNF protein at 18-24?h. Our data suggest that an early activation of protein kinases may trigger CREB-dependent BDNF transcription, resulting in a subsequent increase of BDNF protein in response to ConBr. Later, increment of Akt phosphorylation was observed 24?h after ConBr administration, possibly due to BDNF/TrkB-dependent activation of Akt. Our findings indicate that ConBr is a multifunctional molecule capable to activate signaling pathways involved in neuroplasticity and neuroprotection. PMID:25319623

  8. Rapid Assays for Lectin Toxicity and Binding Changes that Reflect Altered Glycosylation in Mammalian Cells

    PubMed Central

    Stanley, Pamela; Sundaram, Subha

    2014-01-01

    Glycosylation engineering is used to generate glycoproteins, glycolipids or proteoglycans with a more defined complement of glycans on their glycoconjugates. For example, a mammalian cell glycosylation mutant lacking a specific glycosyltransferase generates glycoproteins, and/or glycolipids, and/or proteoglycans, with truncated glycans missing the sugar transferred by that glycosyltransferase, and also missing those sugars that would be added subsequently. In some cases, an alternative glycosyltransferase may then use the truncated glycans as acceptors, thereby generating a new or different glycan subset in the mutant cell. Another type of glycosylation mutant arises from gain-of-function mutations that, for example, activate a silent glycosyltransferase gene. In this case, glycoconjugates will have glycans with additional sugar(s) that are more elaborate than the glycans of wild type cells. Mutations in other genes that affect glycosylation, such as nucleotide sugar synthases or transporters, will alter the glycan complement in more general ways that usually affect several types of glycoconjugates. There are now many strategies for generating a precise mutation in a glycosylation gene in a mammalian cell. Large-volume cultures of mammalian cells may also give rise to spontaneous mutants in glycosylation pathways. This article will focus on how to rapidly characterize mammalian cells with an altered glycosylation activity. The key reagents for the protocols described are plant lectins that bind mammalian glycans with varying avidities, depending on the specific structure of those glycans. Cells with altered glycosylation generally become resistant or hypersensitive to lectin toxicity, and have reduced or increased lectin or antibody binding. Here we describe rapid assays to compare the cytotoxicity of lectins in a lectin resistance test, and the binding of lectins or antibodies by flow cytometry in a glycan-binding assay. Based on these tests, glycosylation changes expressed by a cell can be revealed, and glycosylation mutants classified into phenotypic groups that may reflect a loss-of-function or gain-of-function mutation in a specific gene involved in glycan synthesis. PMID:24903886

  9. Mannose-Binding Lectin Inhibits Monocyte Proliferation through Transforming Growth Factor-?1 and p38 Signaling Pathways

    PubMed Central

    Wang, Yan; Chen, A-De; Lei, Yan-Mei; Shan, Gui-Qiu; Zhang, Li-Yun; Lu, Xiao; Chen, Zheng-Liang

    2013-01-01

    Mannose-binding lectin (MBL), a plasma C-type lectin, plays an important role in innate immunity. However, the interaction, and the consequences of it, between MBL and the immune system remain ill defined. We have investigated the contributing mechanisms and effects of MBL on the proliferation of human monocytes. At lower concentrations (?4 ?g/ml) MBL was shown to partially enhance monocyte proliferation. By contrast, at higher concentrations (8–20 ?g/ml) of MBL, cell proliferation was markedly attenuated. MBL-induced growth inhibition was associated with G0/G1 arrest, down-regulation of cyclin D1/D3, cyclin-dependent kinase (Cdk) 2/Cdk4 and up-regulation of the Cdk inhibitory protein Cip1/p21. Additionally, MBL induced apoptosis, and did so through caspase-3 activation and poly ADP-ribose polymerase (PARP) cleavage. Moreover, transforming growth factor (TGF)-?1 levels increased in the supernatants of MBL-stimulated monocyte cultures. We also found that MBL-dependent inhibition of monocyte proliferation could be reversed by the TGF-? receptor antagonist SB-431542, or by anti-TGF-?1 antibody, or by the mitogen-activated protein kinase (MAPK) inhibitors specific for p38 (SB203580), but not ERK (U0126) or JNK (SP600125). Thus, at high concentrations, MBL can affect the immune system by inhibiting monocyte proliferation, which suggests that MBL may exhibit anti-inflammatory effects. PMID:24039775

  10. Activation of Ras and mitogen-activated protein kinase pathway by terminal complement complexes is G protein dependent.

    PubMed

    Niculescu, F; Rus, H; van Biesen, T; Shin, M L

    1997-05-01

    Assembly of terminal complement complexes (TCC) C5b-7, C5b-8, and C5b-9 on target cells during acute and chronic inflammation induces hydrolysis of plasma membrane phospholipids and heterotrimeric G protein activation. TCC also stimulate a variety of cellular activities, which include cytokine synthesis, proto-oncogene activation, and mitotic signaling. Now we report that sublytic TCC induced Ras, Raf-1, and extracellular signal-regulated kinase (ERK) 1 activation in JY25 B cell line. When cells were exposed to C5b-9, GTP-bound Ras in anti-C5b-9 immunoprecipitates was increased 3.2-fold at 2 min, while GTP-bound Ras in anti-Ras immunoprecipitates was increased 2-fold at 10 min. Both C5b-9 and C5b-7, but not C5b6, increased Raf-1 kinase activity maximum 3.3-fold at 2 min and 2.8-fold at 5 min, respectively. ERK1 activity was 2-fold increased by C5b-9 at 2 min and by C5b-7 at 10 min, over the C5b6 level. The role of mitogen-activated protein kinase (MAPK) pathway on TCC-inducible mitotic signaling was evaluated by assessing DNA synthesis and activator protein 1 (AP-1) DNA-binding activity. The MAPK/ERK-specific inhibitor PD 098,059 abolished the C5b-9-induced DNA synthesis. Involvement of G protein in the activation of MAPK pathway by TCC was indicated by inhibition of Raf-1 and ERK1 kinase activity, as well as the DNA synthesis by pretreatment of cells with pertussis toxin. Overexpression of beta-adrenergic receptor kinase 1 carboxyl-terminal peptide in JY25 cells also inhibited Raf-1 and ERK1 activity, indicating a direct involvement of G betagamma subunits in the signal transduction generated through activation of MAPK pathway by TCC assembly in the plasma membrane. PMID:9127005

  11. Roles of adipocytes and fibroblasts in activation of the alternative pathway of complement in inflammatory arthritis in mice.

    PubMed

    Arend, William P; Mehta, Gaurav; Antonioli, Alexandra H; Takahashi, Minoru; Takahashi, Kazue; Stahl, Gregory L; Holers, V Michael; Banda, Nirmal K

    2013-06-15

    The complement system is involved in mediation of joint damage in rheumatoid arthritis, with evidence suggesting activation of both the classical and alternative pathway (AP). The AP is both necessary and sufficient to mediate collagen Ab-induced arthritis, an experimental animal model of immune complex-induced joint disease. The AP in mice is dependent on MASP-1/3 cleavage of pro-factor D (pro-FD) into mature factor D (FD). The objectives of the current study were to determine the cells synthesizing MASP-1/3 and pro-FD in synovial tissue. Collagen Ab-induced arthritis was studied in wild-type C57BL/6 mice, and the localization of mRNA and protein for FD and MASP-1/3 in synovial adipose tissue (SAT) and fibroblast-like synoviocytes (FLS) was determined using various techniques, including laser capture microdissection. SAT was the sole source of mRNA for pro-FD. Cultured differentiated 3T3 adipocytes, a surrogate for SAT, produced pro-FD but no mature FD. FLS were the main source of MASP-1/3 mRNA and protein. Using cartilage microparticles (CMPs) coated with anti-collagen mAb and serum from MASP-1/3(-/-) mice as a source of factor B, pro-FD in 3T3 supernatants was cleaved into mature FD by MASP-1/3 in FLS supernatants. The mature FD was eluted from the CMP, and was not present in the supernatants from the incubation with CMP, indicating that cleavage of pro-FD into mature FD by MASP-1 occurred on the CMP. These results demonstrate that pathogenic activation of the AP can occur in the joint through immune complexes adherent to cartilage and the local production of necessary AP proteins by adipocytes and FLS. PMID:23650618

  12. Mannose-binding lectin polymorphisms and rheumatoid arthritis: A short review and meta-analysis.

    PubMed

    Epp Boschmann, Stefanie; Goeldner, Isabela; Tuon, Felipe Francisco; Schiel, Wagner; Aoyama, Fernanda; de Messias-Reason, Iara J

    2016-01-01

    Mannose-binding lectin (MBL) is a pattern recognition receptor of the lectin pathway of complement system. MBL binds to carbohydrates on microorganism's surfaces leading to complement activation, opsonization and phagocytosis. Polymorphisms in the MBL gene (MBL2) are associated with variations on MBL serum levels and with the susceptibility to various infectious and autoimmune diseases. The involvement of the lectin pathway in rheumatoid arthritis (RA) has been demonstrated by several studies and although MBL has been considered to have a dual role in the pathogenesis of the disease, the association between MBL and RA remains inconclusive. In an attempt to clarify this relationship, we developed this short review summarizing accumulated evidences in regard to MBL and RA and a meta-analysis to evaluate the influence of MBL2 polymorphisms on the susceptibility to RA. Among a total of 217 articles that were identified following a predefined search strategy on PubMed, Scopus, Scielo, EMBASE and Cochrane databases, only 13 met all inclusion criteria and were included in the meta-analysis. Data assessment was conducted by three independent investigators and presented in odds ratio (OR) and 95% confidence intervals (CIs) using forest plot charts. Both heterogeneity and publication bias were analyzed. The results of the meta-analysis evidenced that MBL2 low producing OO and XX genotypes do not confer higher risk to RA, even when data were analyzed according to cohort's ethnicity. Further studies are needed in order to clarify the importance of other genes of the lectin pathway in the pathogenesis of RA. PMID:26608926

  13. Hematin promotes complement alternative pathway-mediated deposition of C3 activation fragments on human erythrocytes: potential implications for the pathogenesis of anemia in malaria.

    PubMed

    Pawluczkowycz, Andrew W; Lindorfer, Margaret A; Waitumbi, John N; Taylor, Ronald P

    2007-10-15

    Childhood malaria caused by Plasmodium falciparum is often characterized by severe anemia at low parasite burdens; the mechanism(s) responsible for this pathology remain to be defined. We have reported, based on clinical observations and in vitro models, that complement control proteins on erythrocytes such as CR1, the immune adherence receptor specific for C3b, may be reduced in childhood malaria, suggesting a possible role for complement in erythrocyte destruction. Intravascular lysis of iE by P. falciparum leads to release of erythrocyte breakdown products such as hemoglobin and hematin, which have inflammatory properties. In the present article, we demonstrate that in serum and in anticoagulated whole blood, moderate concentrations of hematin activate the alternative pathway of complement and promote deposition of C3 activation and breakdown products on erythrocytes. The degree of C3 fragment deposition is directly correlated with erythrocyte CR1 levels, and erythrocytes opsonized with large amounts of C3dg form rosettes with Raji cells, which express CR2, the C3dg receptor which is expressed on several types of B cells in the spleen. Thus, the reaction mediated by hematin promotes opsonization and possible clearance of the youngest (highest CR1) erythrocytes. A mAb specific for C3b, previously demonstrated to inhibit the alternative pathway of complement, completely blocks the C3 fragment deposition reaction. Use of this mAb in nonhuman primate models of malaria may provide insight into mechanisms of erythrocyte destruction and thus aid in the development of targeted therapies based on inhibiting the alternative pathway of complement. PMID:17911641

  14. Infections of People with Complement Deficiencies and Patients Who Have Undergone Splenectomy

    PubMed Central

    Ram, Sanjay; Lewis, Lisa A.; Rice, Peter A.

    2010-01-01

    Summary: The complement system comprises several fluid-phase and membrane-associated proteins. Under physiological conditions, activation of the fluid-phase components of complement is maintained under tight control and complement activation occurs primarily on surfaces recognized as “nonself” in an attempt to minimize damage to bystander host cells. Membrane complement components act to limit complement activation on host cells or to facilitate uptake of antigens or microbes “tagged” with complement fragments. While this review focuses on the role of complement in infectious diseases, work over the past couple of decades has defined several important functions of complement distinct from that of combating infections. Activation of complement in the fluid phase can occur through the classical, lectin, or alternative pathway. Deficiencies of components of the classical pathway lead to the development of autoimmune disorders and predispose individuals to recurrent respiratory infections and infections caused by encapsulated organisms, including Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae. While no individual with complete mannan-binding lectin (MBL) deficiency has been identified, low MBL levels have been linked to predisposition to, or severity of, several diseases. It appears that MBL may play an important role in children, who have a relatively immature adaptive immune response. C3 is the point at which all complement pathways converge, and complete deficiency of C3 invariably leads to severe infections, including those caused by meningococci and pneumococci. Deficiencies of the alternative and terminal complement pathways result in an almost exclusive predisposition to invasive meningococcal disease. The spleen plays an important role in antigen processing and the production of antibodies. Splenic macrophages are critical in clearing opsonized encapsulated bacteria (such as pneumococci, meningococci, and Escherichia coli) and intraerythrocytic parasites such as those causing malaria and babesiosis, which explains the fulminant nature of these infections in persons with anatomic or functional asplenia. Paramount to the management of patients with complement deficiencies and asplenia is educating patients about their predisposition to infection and the importance of preventive immunizations and seeking prompt medical attention. PMID:20930072

  15. Complement C3

    E-print Network

    Dinasarapu, Ashok Reddy; Chandrasekhar, Anjana; Sahu, Arvind; Subramaniam, Shankar

    2012-01-01

    Mutations in alternative pathway complement proteins inand protein kinase C. Effects on the classical and alternativeproteins: factor I-mediated degradation of C3b to iC3b1 inactivates the alternative

  16. Sundanese Complementation

    ERIC Educational Resources Information Center

    Kurniawan, Eri

    2013-01-01

    The focus of this thesis is the description and analysis of clausal complementation in Sundanese, an Austronesian language spoken in Indonesia. The thesis examined a range of clausal complement types in Sundanese, which consists of (i) "yen/(wi)rehna" "that" complements, (ii) "pikeun" "for" complements,…

  17. Complement mediators: key regulators of airway tissue remodeling in asthma.

    PubMed

    Khan, Mohammad Afzal; Assiri, Abdullah Mohammed; Broering, Dieter Clemens

    2015-01-01

    The complement mediators are the major effectors of the immune balance, which operates at the interface between the innate and adaptive immunity, and is vital for many immunoregulatory functions. Activation of the complement cascade through the classical, alternative or lectin pathways thus generating opsonins like C3b and C5b, anaphylatoxins C3a and C5a, chemotaxin, and inflammatory mediators, which leads to cellular death. Complement mediators that accelerate the airway remodeling are not well defined; however, an uncontrolled Th2-driven adaptive immune response has been linked to the major pathophysiologic features of asthma, including bronchoconstriction, airway hyperresponsiveness, and airway inflammation. The mechanisms leading to complement mediated airway tissue remodeling, and the effect of therapy on preventing and/or reversing it are not clearly understood. This review highlights complement-mediated inflammation, and the mechanism through it triggers the airway tissue injury and remodeling in the airway epithelium that could serve as potential targets for developing a new drug to rescue the asthma patients. PMID:26289385

  18. The role of complement in the pathogenesis of renal ischemia-reperfusion injury and fibrosis

    PubMed Central

    2014-01-01

    The complement system is a major component of innate immunity and has been commonly identified as a central element in host defense, clearance of immune complexes, and tissue homeostasis. After ischemia-reperfusion injury (IRI), the complement system is activated by endogenous ligands that trigger proteolytic cleavage of complement components via the classical, lectin and/or alternative pathway. The result is the formation of terminal complement components C3a, C5a, and the membrane attack complex (C5b-9 or MAC), all of which play pivotal roles in the amplification of the inflammatory response, chemotaxis, neutrophil/monocyte recruitment and activation, and direct tubular cell injury. However, recent evidence suggests that complement activity transcends innate host defense and there is increasing data suggesting complement as a regulator in processes such as allo-immunity, stem cell differentiation, tissue repair, and progression to fibrosis. In this review, we discuss recent advances addressing the role of complement as a regulator of IRI and renal fibrosis after organ donation for transplantation. We will also briefly discuss currently approved therapies that target complement activity in kidney ischemia-reperfusion and transplantation. PMID:25383094

  19. Regulatory Components of the Alternative Complement Pathway in Endothelial Cell Cytoplasm, Factor H and Factor I, Are Not Packaged in Weibel-Palade Bodies

    PubMed Central

    Turner, Nancy A.; Sartain, Sarah E.; Hui, Shiu-Ki; Moake, Joel L.

    2015-01-01

    It was recently reported that factor H, a regulatory component of the alternative complement pathway, is stored with von Willebrand factor (VWF) in the Weibel-Palade bodies of endothelial cells. If this were to be the case, it would have therapeutic importance for patients with the atypical hemolytic-uremic syndrome that can be caused either by a heterozygous defect in the factor H gene or by the presence of an autoantibody against factor H. The in vivo Weibel-Palade body secretagogue, des-amino-D-arginine vasopressin (DDAVP), would be expected to increase transiently the circulating factor H levels, in addition to increasing the circulating levels of VWF. We describe experiments demonstrating that factor H is released from endothelial cell cytoplasm without a secondary storage site. These experiments showed that factor H is not stored with VWF in endothelial cell Weibel-Palade bodies, and is not secreted in response in vitro in response to the Weibel-Palade body secretagogue, histamine. Furthermore, the in vivo Weibel-Palade body secretagogue, DDAVP does not increase the circulating factor H levels concomitantly with DDAVP-induced increased VWF. Factor I, a regulatory component of the alternative complement pathway that is functionally related to factor H, is also located in endothelial cell cytoplasm, and is also not present in endothelial cell Weibel-Palade bodies. Our data demonstrate that the factor H and factor I regulatory proteins of the alternative complement pathway are not stored in Weibel-Palade bodies. DDAVP induces the secretion into human plasma of VWF —- but not factor H. PMID:25803806

  20. Early graft failure of GalTKO pig organs in baboons is reduced by expression of a human complement pathway-regulatory protein.

    PubMed

    Azimzadeh, Agnes M; Kelishadi, Sean S; Ezzelarab, Mohamed B; Singh, Avneesh K; Stoddard, Tiffany; Iwase, Hayato; Zhang, Tianshu; Burdorf, Lars; Sievert, Evelyn; Avon, Chris; Cheng, Xiangfei; Ayares, David; Horvath, Keith A; Corcoran, Philip C; Mohiuddin, Muhammad M; Barth, Rolf N; Cooper, David K C; Pierson, Richard N

    2015-01-01

    We describe the incidence of early graft failure (EGF, defined as loss of function from any cause within 3 days after transplant) in a large cohort of GalTKO pig organs transplanted into baboons in three centers, and the effect of additional expression of a human complement pathway-regulatory protein, CD46 or CD55 (GalTKO.hCPRP). Baboon recipients of life-supporting GalTKO kidney (n = 7) or heterotopic heart (n = 14) grafts received either no immunosuppression (n = 4), or one of several partial or full immunosuppressive regimens (n = 17). Fourteen additional baboons received a GalTKO.hCPRP kidney (n = 5) or heart (n = 9) and similar treatment regimens. Immunologic, pathologic, and coagulation parameters were measured at frequent intervals. EGF of GalTKO organs occurred in 9/21 baboons (43%). hCPRP expression reduced the GalTKO EGF incidence to 7% (1/14; P < 0.01 vs. GalTKO alone). At 30 mins, complement deposits were more intense in organs in which EGF developed (P < 0.005). The intensity of peri-transplant platelet activation (as ?-thromboglobulin release) correlated with EGF, as did the cumulative coagulation score (P < 0.01). We conclude that (i) the transgenic expression of a hCPRP on the vascular endothelium of a GalTKO pig reduces the incidence of EGF and reduces complement deposition, (ii) complement deposition and platelet activation correlate with early GalTKO organ failure, and (iii) the expression of a hCPRP reduces EGF but does not prevent systemic coagulation activation. Additional strategies will be required to control coagulation activation. PMID:26174749

  1. Mannose binding lectin and C3 act as recognition molecules for infectious agents in the vagina

    PubMed Central

    Pellis, V; De Seta, F; Crovella, S; Bossi, F; Bulla, R; Guaschino, S; Radillo, O; Garred, P; Tedesco, F

    2005-01-01

    In our study we examined the early complement components in patients with bacterial vaginosis (BV), vulvovaginal candidiasis (VVC) and in healthy controls. The levels of C1q, mannose-binding lectin (MBL) and C3 were measured by ELISA in the cervicovaginal lavage (CVL) from gynaecological patients and controls. No significant differences were observed in the levels of these proteins in the three study groups. Immunofluorescence analysis of the clue cells and Candida hyphae from BV and VVC patients for surface-bound complement components showed the presence of C3, while C1q was undetectable. MBL was revealed on clue cells but not on Candida. Binding of MBL to Candida, grown or cytocentrifuged from the CVL of VVC patients, was found to be pH dependent and occurred between pH 4·5 and pH 5·5. In conclusion, we demonstrated that MBL and C3 present in the vaginal cavity act as recognition molecules for infectious agents that colonize the cervicovaginal mucosa. Our finding that MBL, but not C1q, binds to bacteria and fungi in vagina suggests that the lectin and classical pathways of complement activation may play a different role in immune defence in the female genital tract. PMID:15606621

  2. Mannose binding lectin and C3 act as recognition molecules for infectious agents in the vagina.

    PubMed

    Pellis, V; De Seta, F; Crovella, S; Bossi, F; Bulla, R; Guaschino, S; Radillo, O; Garred, P; Tedesco, F

    2005-01-01

    In our study we examined the early complement components in patients with bacterial vaginosis (BV), vulvovaginal candidiasis (VVC) and in healthy controls. The levels of C1q, mannose-binding lectin (MBL) and C3 were measured by ELISA in the cervicovaginal lavage (CVL) from gynaecological patients and controls. No significant differences were observed in the levels of these proteins in the three study groups. Immunofluorescence analysis of the clue cells and Candida hyphae from BV and VVC patients for surface-bound complement components showed the presence of C3, while C1q was undetectable. MBL was revealed on clue cells but not on Candida. Binding of MBL to Candida, grown or cytocentrifuged from the CVL of VVC patients, was found to be pH dependent and occurred between pH 4.5 and pH 5.5. In conclusion, we demonstrated that MBL and C3 present in the vaginal cavity act as recognition molecules for infectious agents that colonize the cervicovaginal mucosa. Our finding that MBL, but not C1q, binds to bacteria and fungi in vagina suggests that the lectin and classical pathways of complement activation may play a different role in immune defence in the female genital tract. PMID:15606621

  3. Complement in hemolytic anemia.

    PubMed

    Brodsky, Robert A

    2015-11-26

    Complement is increasingly being recognized as an important driver of human disease, including many hemolytic anemias. Paroxysmal nocturnal hemoglobinuria (PNH) cells are susceptible to hemolysis because of a loss of the complement regulatory proteins CD59 and CD55. Patients with atypical hemolytic uremic syndrome (aHUS) develop a thrombotic microangiopathy (TMA) that in most cases is attributable to mutations that lead to activation of the alternative pathway of complement. For optimal therapy, it is critical, but often difficult, to distinguish aHUS from other TMAs, such as thrombotic thrombocytopenic purpura; however, novel bioassays are being developed. In cold agglutinin disease (CAD), immunoglobulin M autoantibodies fix complement on the surface of red cells, resulting in extravascular hemolysis by the reticuloendothelial system. Drugs that inhibit complement activation are increasingly being used to treat these diseases. This article discusses the pathophysiology, diagnosis, and therapy for PNH, aHUS, and CAD. PMID:26582375

  4. A sulfated cyanobacterial polysaccharide proven as a strong inhibitor of human complement activity in an in vitro assay.

    PubMed

    Flamm, Daniela; Blaschek, Wolfgang

    2014-08-01

    Cyanobacterial exopolysaccharides are a rich source of, so far, widely unexplored polysaccharides. One of these exopolysaccharides is a highly sulfated, linear polysaccharide from Synechocystis aquatilis containing the amino sugar N-acetyl-fucosamine. Some sulfated polysaccharides and glycosaminoglycans are known to be inhibitors of the human complement system, which is an important part of the innate immune system. Defects in this system or misregulation can cause serious diseases. Therefore, new compounds with complement inhibiting activity and simple test assays are of great interest. Exopolysaccharides from S. aquatilis (arabinofucans) were compared to those from Synechocystis pevalekii (complex heteropolysaccharides) and the well-known complement inhibitor heparin. Investigations were performed with a modified ELISA test system based on a commercially available test kit quantifying the membrane attack complex. Hereby the testing becomes more stable, robust, reproducible, easier to handle and, for the first time, the effect of exopolysaccharides and heparin on the lectin pathway could be tested. The exopolysaccharides from S. aquatilis could be shown to be a 30 times stronger inhibitor of the classical pathway of the complement system compared to heparin (IC50?=?0.3?µg/mL vs. 9.2?µg/mL). These exopolysaccharides are also inhibitors of the lectin pathway (IC50?=?10.8?µg/mL) in which, however, heparin is more potent (IC50?=?2.0?µg/mL). Interestingly, these exopolysaccharides do not inhibit the alternative pathway. The exopolysaccharides from S. pevalekii are inactive in all pathways. Furthermore, partially hydrolyzed and desulfated exopolysaccharides from S. aquatilis were tested showing that a minimum molecular size and degree of sulfation are important for the inhibitory effects, whereas unspecific influences by complex formation of exopolysaccharides with calcium could be excluded. PMID:25144674

  5. Complement-mediated injury and protection of endothelium: Lessons from atypical haemolytic uraemic syndrome

    PubMed Central

    Kerr, Heather; Richards, Anna

    2014-01-01

    The complement system provides a vital defence against invading pathogens. As an intrinsic system it is always ‘on’, in a state of constant, low level activation. This activation is principally mediated through the deposition of C3b on to pathogenic surfaces and host tissues. C3b is generated by spontaneous ‘tick over’ and formal activation of the alternative pathway, and by activation of the classical and lectin pathways. If the deposited C3b is not appropriately regulated, there is progression to terminal pathway complement activation via the C5 convertases, generating the potent anaphylotoxin C5a and the membrane attack complex C5b-9. Unsurprisingly, these highly active components have the potential to cause injury to bystander host tissue, including the vascular endothelium. As such, complement activation on endothelium is normally tightly controlled by a large number of fluid-phase and membrane bound inhibitors, in an attempt to ensure that propagation of complement activation is appropriately restricted to invading pathogens and altered ‘self’, e.g. apoptotic and necrotic cells. The kidney is increasingly recognised as a site at particular risk from complement-mediated endothelial injury. Both genetic and acquired defects which impact on complement regulation predispose to this susceptibility. The thrombotic microangiopathy, haemolytic uraemic syndrome (HUS), will be used to illustrate the mechanisms by which the endothelial cell injury occurs. Finally, the underlying rationale for current and future potential therapeutic interventions in HUS and also the opportunities for enhancing endothelial defence to prevent relapsing disease through increased complement cytoprotective strategies will be summarised. PMID:21855165

  6. Surface-bound capsular polysaccharide of type Ia group B Streptococcus mediates C1 binding and activation of the classic complement pathway

    SciTech Connect

    Levy, N.J.; Kasper, D.L.

    1986-06-01

    The role of surface-bound type Ia group B Streptococcus (GBS) capsular polysaccharide in anti-body-independent binding of C1 and activation of the classic component pathway was investigated. In a radiolabeled bacterial-polymorphonuclear leukocyte (PMN) association assay, a measure of bacterial opsonization, preincubation of /sup 3/H-type Ia GBS with purified F(ab')/sub 2/ to the organism blocked the association of the bacteria with PMN', and the inhibitory effect was dose dependent. The specificity of F(ab')/sub 2/ blocking was shown after adsorption of F(ab')/sub 2/ with type Ia polysaccharide-sensitized erythrocytes. Polysaccharide-adsorbed F(ab')/sub 2/ had a 70% decrease in ability to block the association of bacteria with PMN. Neuraminidase digestion removed 80% of the terminal sialic acid residues from the native polysaccharide. These neuraminidase-digested organisms had a 72% decrease in binding and transfer of purified C1 compared with non-enzyme-treated organisms. Type Ia capsular polysaccharide bound to sheep erythrocytes promoted classic complement pathway-mediated hemolysis of the cells. The role of C1 inhibitor (INH) in modulation of C1 activation by the organisms was investigated. The possibility existed that the C1 INH could be bound by the bacteria, allowing C1 activation to occur in the fluid phase. The inhibitor was purified from human serum, and its activity was measured before and after incubation with type Ia GBS. The organisms had no effect on C1 INH activity. Thus surface-bound capsular polysacchardie of type Ia GBS mediates C1 binding and classic pathway activation, and this does not involve the C1 INH.

  7. CD45-mediated signaling pathway is involved in Rhizoctonia bataticola lectin (RBL)-induced proliferation and Th1/Th2 cytokine secretion in human PBMC

    SciTech Connect

    Pujari, Radha; Eligar, Sachin M.; Kumar, Natesh; Nagre, Nagaraja N.; Inamdar, Shashikala R.; Swamy, Bale M.; Shastry, Padma

    2012-03-23

    Highlights: Black-Right-Pointing-Pointer RBL, a potent mitogenic and complex N-glycan specific lectin binds to CD45 on PBMC. Black-Right-Pointing-Pointer RBL triggers CD45-mediated signaling involved in activation of p38MAPK and STAT-5. Black-Right-Pointing-Pointer Inhibition of CD45 PTPase signaling blocks RBL-induced ZAP70 phosphorylation. Black-Right-Pointing-Pointer RBL-CD45 mediated signaling is crucial for RBL-induced immunodulatory activities. -- Abstract: We earlier reported the mitogenic and immunostimulatory activities of Rhizoctonia bataticola lectin (RBL), purified from phytopathogenic fungus R. bataticola in human PBMC. The lectin demonstrates specificity towards glycoproteins containing complex N-glycans. Since CD45-protein tyrosine phosphatase that abundantly expresses N-glycans is important in T-cell signaling, the study aimed to investigate the involvement of CD45 in the immunomodulatory activities of RBL. Flowcytometry and confocal microscopy studies revealed that RBL exhibited binding to PBMC and colocalized with CD45. The binding was comparable in cells expressing different CD45 isoforms-RA, -RB and -RO. CD45 blocking antibody reduced the binding and proliferation of PBMC induced by RBL. CD45-PTPase inhibitor dephostatin inhibited RBL-induced proliferation, expression of CD25 and pZAP-70. RBL-induced secretion of Th1/Th2 cytokines were significantly inhibited in presence of dephostatin. Also, dephostatin blocked phosphorylation of p38MAPK and STAT-5 that was crucial for the biological functions of RBL. The study demonstrates the involvement of CD45-mediated signaling in RBL-induced PBMC proliferation and Th1/Th2 cytokine secretion through activation of p38MAPK and STAT-5.

  8. Inhibition of the Alternative Pathway of Nonhuman Infant Complement by Porin B2 Contributes to Virulence of Neisseria meningitidis in the Infant Rat Model

    PubMed Central

    Vu, David M.; Granoff, Dan M.; Ram, Sanjay

    2014-01-01

    Neisseria meningitidis utilizes capsular polysaccharide, lipooligosaccharide (LOS) sialic acid, factor H binding protein (fHbp), and neisserial surface protein A (NspA) to regulate the alternative pathway (AP) of complement. Using meningococcal mutants that lacked all four of the above-mentioned molecules (quadruple mutants), we recently identified a role for PorB2 in attenuating the human AP; inhibition was mediated by human fH, a key downregulatory protein of the AP. Previous studies showed that fH downregulation of the AP via fHbp or NspA is specific for human fH. Here, we report that PorB2-expressing quadruple mutants also regulate the AP of baby rabbit and infant rat complement. Blocking a human fH binding region on PorB2 of the quadruple mutant of strain 4243 with a chimeric protein that comprised human fH domains 6 and 7 fused to murine IgG Fc enhanced AP-mediated baby rabbit C3 deposition, which provided evidence for an fH-dependent mechanism of nonhuman AP regulation by PorB2. Using isogenic mutants of strain H44/76 that differed only in their PorB molecules, we confirmed a role for PorB2 in resistance to killing by infant rat serum. The PorB2-expressing strain also caused higher levels of bacteremia in infant rats than its isogenic PorB3-expressing counterpart, thus providing a molecular basis for increased survival of PorB2 isolates in this model. These studies link PorB2 expression with infection of infant rats, which could inform the choice of meningococcal strains for use in animal models, and reveals, for the first time, that PorB2-expressing strains of N. meningitidis regulate the AP of baby rabbits and rats. PMID:24686052

  9. Mild hypothermia inhibits systemic and cerebral complement activation in a swine model of cardiac arrest.

    PubMed

    Gong, Ping; Zhao, Hong; Hua, Rong; Zhang, Mingyue; Tang, Ziren; Mei, Xue; Cui, Juan; Li, Chunsheng

    2015-08-01

    Complement activation has been implicated in ischemia/reperfusion injury. This study aimed to determine whether mild hypothermia (HT) inhibits systemic and cerebral complement activation after resuscitation from cardiac arrest. Sixteen minipigs resuscitated from 8 minutes of untreated ventricular fibrillation were randomized into two groups: HT group (n=8), treated with HT (33°C) for 12 hours; and normothermia group (n=8), treated similarly as HT group except for cooling. Blood samples were collected at baseline and 0.5, 6, 12, and 24 hours after return of spontaneous circulation (ROSC). The brain cortex was harvested 24 hours after ROSC. Complement and pro-inflammatory markers were detected using enzyme-linked immunosorbent assay. Neurologic deficit scores were evaluated 24 hours after ROSC. C1q, Bb, mannose-binding lectin (MBL), C3b, C3a, C5a, interleukin-6, and tumor necrosis factor-? levels were significantly increased under normothermia within 24 hours after ROSC. However, these increases were significantly reduced by HT. Hypothermia decreased brain C1q, MBL, C3b, and C5a contents 24 hours after ROSC. Hypothermic pigs had a better neurologic outcome than normothermic pigs. In conclusion, complement is activated through classic, alternative, and MBL pathways after ROSC. Hypothermia inhibits systemic and cerebral complement activation, which may provide an additional mechanism of cerebral protection. PMID:25757755

  10. Entamoeba histolytica and E. dispar Calreticulin: inhibition of classical complement pathway and differences in the level of expression in amoebic liver abscess.

    PubMed

    Ximénez, Cecilia; González, Enrique; Nieves, Miriam E; Silva-Olivares, Angélica; Shibayama, Mineko; Galindo-Gómez, Silvia; Escobar-Herrera, Jaime; García de León, Ma Del Carmen; Morán, Patricia; Valadez, Alicia; Rojas, Liliana; Hernández, Eric G; Partida, Oswaldo; Cerritos, René

    2014-01-01

    The role of calreticulin (CRT) in host-parasite interactions has recently become an important area of research. Information about the functions of calreticulin and its relevance to the physiology of Entamoeba parasites is limited. The present work demonstrates that CRT of both pathogenic E. histolytica and nonpathogenic E. dispar species specifically interacted with human C1q inhibiting the activation of the classical complement pathway. Using recombinant EhCRT protein, we demonstrate that CRT interaction site and human C1q is located at the N-terminal region of EhCRT. The immunofluorescence and confocal microscopy experiments show that CRT and human C1q colocalize in the cytoplasmic vesicles and near to the surface membrane of previously permeabilized trophozoites or are incubated with normal human serum which is known to destroy trophozoites. In the presence of peripheral mononuclear blood cells, the distribution of EhCRT and C1q is clearly over the surface membrane of trophozoites. Nevertheless, the level of expression of CRT in situ in lesions of amoebic liver abscess (ALA) in the hamster model is different in both Entamoeba species; this molecule is expressed in higher levels in E. histolytica than in E. dispar. This result suggests that EhCRT may modulate some functions during the early moments of the host-parasite relationship. PMID:24860808

  11. Effect of the extract of the tamarind (Tamarindus indica) fruit on the complement system: studies in vitro and in hamsters submitted to a cholesterol-enriched diet.

    PubMed

    Landi Librandi, Ana Paula; Chrysóstomo, Taís Nader; Azzolini, Ana Elisa C S; Recchia, Carem Gledes Vargas; Uyemura, Sérgio Akira; de Assis-Pandochi, Ana Isabel

    2007-08-01

    This work evaluated a crude hydroalcoholic extract (ExT) from the pulp of the tamarind (Tamarindus indica) fruit as a source of compounds active on the complement system (CS) in vitro. ExT, previously characterized by other authors, had time and concentration dependent effects on the lytic activity of the CS. The activity of 0.8 mg/mL of the extract on the classical/lectin pathways (CP/LP) increased after 30 min of pre-incubation, while that of the alternative pathway (AP) decreased after 15 min at 1mg/mL. Since the CS is a mediator of inflammation, studies were also made in vivo, taking advantage of a model of hypercholesterolemia in hamsters to investigate the role of CS in the phase preceding the inflammatory process of atherosclerosis. Hamsters submitted to a diet rich in cholesterol showed increased lytic activity of the CP/LP and AP after 45 days. The activity levels of C2 and factor B components on respectively, classical/lectin and alternative pathways of the CS also increased. Early events cooperating to trigger the process of atherosclerotic lesions are not completely understood, and these alterations of complement may participate in these events. When treatment with a diet rich in cholesterol was associated to the furnishing of ExT, evaluation of complement components and complement lytic activity showed values similar to those of the controls, showing that treatment with ExT blocked the increase of complement activity caused by the cholesterol-rich diet. By itself, ExT had no effect on the complement system in vivo. ExT activity on the CS may be of interest for therapy and research purposes. PMID:17383788

  12. Lectin-Dependent Enhancement of Ebola Virus Infection via Soluble and Transmembrane C-type Lectin Receptors

    PubMed Central

    Lear, Calli; Chen, Li; Yantosca, L. Michael; Scully, Corinne; Sarraju, Ashish; Sokolovska, Anna; Zariffard, M. Reza; Eisen, Damon P.; Mungall, Bruce A.; Kotton, Darrell N.; Omari, Amel; Huang, I-Chueh; Farzan, Michael; Takahashi, Kazue; Stuart, Lynda; Stahl, Gregory L.; Ezekowitz, Alan B.; Spear, Gregory T.; Olinger, Gene G.; Schmidt, Emmett V.; Michelow, Ian C.

    2013-01-01

    Mannose-binding lectin (MBL) is a key soluble effector of the innate immune system that recognizes pathogen-specific surface glycans. Surprisingly, low-producing MBL genetic variants that may predispose children and immunocompromised individuals to infectious diseases are more common than would be expected in human populations. Since certain immune defense molecules, such as immunoglobulins, can be exploited by invasive pathogens, we hypothesized that MBL might also enhance infections in some circumstances. Consequently, the low and intermediate MBL levels commonly found in human populations might be the result of balancing selection. Using model infection systems with pseudotyped and authentic glycosylated viruses, we demonstrated that MBL indeed enhances infection of Ebola, Hendra, Nipah and West Nile viruses in low complement conditions. Mechanistic studies with Ebola virus (EBOV) glycoprotein pseudotyped lentiviruses confirmed that MBL binds to N-linked glycan epitopes on viral surfaces in a specific manner via the MBL carbohydrate recognition domain, which is necessary for enhanced infection. MBL mediates lipid-raft-dependent macropinocytosis of EBOV via a pathway that appears to require less actin or early endosomal processing compared with the filovirus canonical endocytic pathway. Using a validated RNA interference screen, we identified C1QBP (gC1qR) as a candidate surface receptor that mediates MBL-dependent enhancement of EBOV infection. We also identified dectin-2 (CLEC6A) as a potentially novel candidate attachment factor for EBOV. Our findings support the concept of an innate immune haplotype that represents critical interactions between MBL and complement component C4 genes and that may modify susceptibility or resistance to certain glycosylated pathogens. Therefore, higher levels of native or exogenous MBL could be deleterious in the setting of relative hypocomplementemia which can occur genetically or because of immunodepletion during active infections. Our findings confirm our hypothesis that the pressure of infectious diseases may have contributed in part to evolutionary selection of MBL mutant haplotypes. PMID:23573288

  13. Lectins with anti-HIV activity: a review.

    PubMed

    Akkouh, Ouafae; Ng, Tzi Bun; Singh, Senjam Sunil; Yin, Cuiming; Dan, Xiuli; Chan, Yau Sang; Pan, Wenliang; Cheung, Randy Chi Fai

    2015-01-01

    Lectins including flowering plant lectins, algal lectins, cyanobacterial lectins, actinomycete lectin, worm lectins, and the nonpeptidic lectin mimics pradimicins and benanomicins, exhibit anti-HIV activity. The anti-HIV plant lectins include Artocarpus heterophyllus (jacalin) lectin, concanavalin A, Galanthus nivalis (snowdrop) agglutinin-related lectins, Musa acuminata (banana) lectin, Myrianthus holstii lectin, Narcissus pseudonarcissus lectin, and Urtica diocia agglutinin. The anti-HIV algal lectins comprise Boodlea coacta lectin, Griffithsin, Oscillatoria agardhii agglutinin. The anti-HIV cyanobacterial lectins are cyanovirin-N, scytovirin, Microcystis viridis lectin, and microvirin. Actinohivin is an anti-HIV actinomycete lectin. The anti-HIV worm lectins include Chaetopterus variopedatus polychaete marine worm lectin, Serpula vermicularis sea worm lectin, and C-type lectin Mermaid from nematode (Laxus oneistus). The anti-HIV nonpeptidic lectin mimics comprise pradimicins and benanomicins. Their anti-HIV mechanisms are discussed. PMID:25569520

  14. Lectins: production and practical applications

    PubMed Central

    2010-01-01

    Lectins are proteins found in a diversity of organisms. They possess the ability to agglutinate erythrocytes with known carbohydrate specificity since they have at least one non-catalytic domain that binds reversibly to specific monosaccharides or oligosaccharides. This articles aims to review the production and practical applications of lectins. Lectins are isolated from their natural sources by chromatographic procedures or produced by recombinant DNA technology. The yields of animal lectins are usually low compared with the yields of plant lectins such as legume lectins. Lectins manifest a diversity of activities including antitumor, immunomodulatory, antifungal, HIV-1 reverse transcriptase inhibitory, and anti-insect activities, which may find practical applications. A small number of lectins demonstrate antibacterial and anti-nematode activities. PMID:20890754

  15. Microencapsulation of lectin anti-cancer agent and controlled release by alginate beads, biosafety approach.

    PubMed

    El-Aassar, M R; Hafez, Elsayed E; El-Deeb, Nehal M; Fouda, Moustafa M G

    2014-08-01

    Hepatocellular carcinoma (HCC) is considered as one of the most aggressive cancer worldwide. In Egypt, the prevalence of HCC is increasing during last years. Recently, drug-loaded microparticles were used to improve the efficiency of various medical treatments. This study is designed to evaluate the anticancer potentialities of lectins against HCC while hinting to its safety usage. The aim is also extended to encapsulate lectins in alginate microbeads for oral drug delivery purposes. The extracted lectins showed anti-proliferative effect against HCC with a percentage of 60.76% by using its nontoxic dose with an up-regulation of P53 gene expression. Concerning the handling of lectin alginate microbeads for oral drug delivery, the prepared lectin alginate beads were ?100?m in diameter. The efficiency of the microcapsules was checked by scanning electron microscopy, the SEM showed the change on the alginate beads surface revealing the successful lectin encapsulation. The release of lectins from the microbeads depended on a variety of factors as the microbeads forming carriers and the amount-encapsulated lectins. The Pisum sativum extracted lectins may be considered as a promising agent in controlling HCC and this solid dosage form could be suitable for oral administration complemented with/or without the standard HCC drugs. PMID:24857870

  16. Could plant lectins become promising anti-tumour drugs for causing autophagic cell death?

    PubMed

    Liu, Z; Luo, Y; Zhou, T-T; Zhang, W-Z

    2013-10-01

    Plant lectins, a group of highly diverse carbohydrate-binding proteins of non-immune origin, are ubiquitously distributed through a variety of plant species, and have recently drawn rising attention due to their remarkable ability to kill tumour cells using mechanisms implicated in autophagy. In this review, we provide a brief outline of structures of some representative plant lectins such as concanavalin A, Polygonatum cyrtonema lectin and mistletoe lectins. These can target autophagy by modulating BNIP-3, ROS-p38-p53, Ras-Raf and PI3KCI-Akt pathways, as well as Beclin-1, in many types of cancer cells. In addition, we further discuss how plant lectins are able to kill cancer cells by modulating autophagic death, for therapeutic purposes. Together, these findings provide a comprehensive perspective concerning plant lectins as promising new anti-tumour drugs, with respect to autophagic cell death in future cancer therapeutics. PMID:24033443

  17. Effect of lectins on the transport of food ingredients in Caco-2 cell cultures.

    PubMed

    Ohno, Y; Naganuma, T; Ogawa, T; Muramoto, K

    2004-01-01

    We investigated the effect of several lectins, such as soy bean lectin (SBA), concanavalin A (Con A), and wheat germ agglutinin (WGA), on the transport of some food ingredients (isoflavones, quercetin glycosides, carnosine/anserine) across Caco-2 cell monolayers. After incubation of food ingredients (0.03 approximately 2 mmol/L) in the presence or absence of lectins (1 approximately 180 microg/ml) on the apical side, aliquots were taken from the apical and basolateral solution, and were subjected to HPLC analysis. We also examined the effect of lectins on the permeability of the tight junction by measuring the transepithelial electrical resistance (TER) value of the Caco-2 cell monolayer. Isoflavones, which was not transported to the basolateral solution without lectins, could be transported in the presence of lectins, whereas their aglycones were detected at the same levels with or without the lectin treatment. The transport of quercetin glycosides also increased in the presence of lectins, however, that of peptides was not affected by the lectins. Con A and WGA, but SBA, decreased the TER value, indicating that Con A and WGA increased the transport via paracellular pathway, whereas SBA did via a different pathway. PMID:15630235

  18. Lysyl Hydroxylase 3 Modifies Lysine Residues to Facilitate Oligomerization of Mannan-Binding Lectin

    PubMed Central

    Risteli, Maija; Ruotsalainen, Heli; Bergmann, Ulrich; Venkatraman Girija, Umakhanth; Wallis, Russell; Myllylä, Raili

    2014-01-01

    Lysyl hydroxylase 3 (LH3) is a multifunctional protein with lysyl hydroxylase, galactosyltransferase and glucosyltransferase activities. The LH3 has been shown to modify the lysine residues both in collagens and also in some collagenous proteins. In this study we show for the first time that LH3 is essential for catalyzing formation of the glucosylgalactosylhydroxylysines of mannan-binding lectin (MBL), the first component of the lectin pathway of complement activation. Furthermore, loss of the terminal glucose units on the derivatized lysine residues in mouse embryonic fibroblasts lacking the LH3 protein leads to defective disulphide bonding and oligomerization of rat MBL-A, with a decrease in the proportion of the larger functional MBL oligomers. The oligomerization could be completely restored with the full length LH3 or the amino-terminal fragment of LH3 that possesses the glycosyltransferase activities. Our results confirm that LH3 is the only enzyme capable of glucosylating the galactosylhydroxylysine residues in proteins with a collagenous domain. In mice lacking the lysyl hydroxylase activity of LH3, but with untouched galactosyltransferase and glucosyltransferase activities, reduced circulating MBL-A levels were observed. Oligomerization was normal, however and residual lysyl hydroxylation was compensated in part by other lysyl hydroxylase isoenzymes. Our data suggest that LH3 is commonly involved in biosynthesis of collagenous proteins and the glucosylation of galactosylhydroxylysines residues by LH3 is crucial for the formation of the functional high-molecular weight MBL oligomers. PMID:25419660

  19. Mannose-binding lectin and the balance between immune protection and complication

    PubMed Central

    Takahashi, Kazue

    2012-01-01

    The innate immune system is evolutionarily ancient and biologically primitive. Historically, it was first identified as an element of the immune system that provides the first-line response to pathogens, and increasingly it is recognized for its central housekeeping role and its essential functions in tissue homeostasis, including coagulation and inflammation, among others. A pivotal link between the innate immune system and other functions is mannose-binding lectin (MBL), a pattern recognition molecule. Multiple studies have demonstrated that MBL deficiency increases susceptibility to infection, and the mechanisms associated with this susceptibility to infection include reduced opsonophagocytic killing and reduced activation of the lectin complement pathway. Results from our laboratory have demonstrated that MBL and MBL-associated serine protease (MASP)-1/3 together mediate coagulation factor-like activities, including thrombin-like activity. MBL and/or MASP-1/3-deficient hosts demonstrate in vivo evidence that MBL and MASP-1/3 are involved with hemostasis following injury. Staphylococcus aureus-infected MBL null mice developed disseminated intravascular coagulation, which was associated with elevated blood IL-6 levels (but not TNF-?) and systemic inflammatory responses. Infected MBL null mice also develop liver injury. These findings suggest that MBL deficiency may manifest as disseminated intravascular coagulation and organ failure with infection. Beginning from these observations, this review focuses on the interaction of innate immunity and other homeostatic systems, the derangement of which may lead to complications in infection and other inflammatory states. PMID:22114968

  20. Complement and autoimmune glomerular diseases.

    PubMed

    Quigg, Richard J

    2004-01-01

    The renal glomerulus is the specialized structure in the kidney responsible for generating over 150 liters of plasma ultrafiltrate per day in humans. Certain characteristics of this structure favor involvement in autoimmune diseases. Formation of immune complexes in the glomerulus, either deposited from the circulation or generated in situ, can activate the complement system. Active products of this system include the anaphylatoxins C3a and C5a, C3b, which covalently associates with immune complexes, and the C5b-9 membrane attack complex. If complement is activated in a site accessible to blood constituents, such as in the subendothelial and mesangial regions, generated C3a, C5a and C3b can interact with their respective receptors on inflammatory cells to lead to an exudative lesion. In addition, intrinsic glomerular cells bearing relevant receptors may also be activated and can proliferate to contribute to the inflammation. In a privileged site such as the subepithelial region, complement activation products are not accessible to blood cells, and as such, the resultant pathology is noninflammatory. In this setting, effects of C5b-9 predominate, which include activation and injury of cells through still incompletely characterized pathways. Various means to alter the complement pathway are now available, including antibody inhibitors and recombinant proteins based upon naturally occurring complement regulators. The use of these agents, as well as mice in which individual components of the complement system have been deleted, has given a great deal of insight into how the complement system is involved in glomerular disease. The ability to manipulate the complement pathway is now a reality in a clinical setting, yet conclusive human studies are difficult to achieve. PMID:14719380

  1. Characterization and expression analysis of a complement component gene in sea cucumber ( Apostichopus japonicus)

    NASA Astrophysics Data System (ADS)

    Chen, Zhong; Zhou, Zunchun; Yang, Aifu; Dong, Ying; Guan, Xiaoyan; Jiang, Bei; Wang, Bai

    2015-12-01

    The complement system plays a crucial role in the innate immune system of animals. It can be activated by distinct yet overlapping classical, alternative and lectin pathways. In the alternative pathway, complement factor B (Bf) serves as the catalytic subunit of complement component 3 (C3) convertase, which plays the central role among three activation pathways. In this study, the Bf gene in sea cucumber ( Apostichopus japonicus), termed AjBf, was obtained by rapid amplification of cDNA ends (RACE). The full-length cDNA of AjBf was 3231 bp in length barring the poly (A) tail. It contained an open reading frame (ORF) of 2742 bp encoding 913 amino acids, a 105 bp 5'-UTR (5'-terminal untranslated region) and a 384 bp 3'-UTR. AjBf was a mosaic protein with six CCP (complement control protein) domains, a VWA (von Willebrand factor A) domain, and a serine protease domain. The deduced molecular weight of AjBf protein was 101 kDa. Quantitative real time PCR (qRT-PCR) analysis indicated that the expression level of AjBf in A. japonicus was obviously higher at larval stage than that at embryonic stage. Expression detection in different tissues showed that AjBf expressed higher in coelomocytes than in other four tissues. In addation, AjBf expression in different tissues was induced significantly after LPS or PolyI:C challenge. These results indicated that AjBf plays an important role in immune responses to pathogen infection.

  2. The outer membrane protease PgtE of Salmonella enterica interferes with the alternative complement pathway by cleaving factors B and H

    PubMed Central

    Riva, Rauna; Korhonen, Timo K.; Meri, Seppo

    2015-01-01

    The virulence factor PgtE is an outer membrane protease (omptin) of the zoonotic pathogen Salmonella enterica that causes diseases ranging from gastroenteritis to severe enteric fever. It is surface exposed in bacteria that have a short-chain, i.e., rough LPS, as observed e.g., in bacteria residing inside macrophages or just emerging from them. We investigated whether PgtE cleaves the complement factors B (B) and H (H), key proteins controlling formation and inactivation of the complement protein C3b and thereby the activity of the complement system. S. enterica serovar Typhimurium or omptin-expressing recombinant E. coli bacteria were incubated with purified human complement proteins or recombinant H fragments. PgtE cleaved both B and H, whereas its close homolog Pla of Yersinia pestis cleaved only H. H was cleaved at both N- and C-termini, while the central region resisted proteolysis. Because of multiple effects of PgtE on complement components (cleavage of C3, C3b, B, and H) we assessed its effect on the opsonophagocytosis of Salmonella. In human serum, C3 cleavage was dependent on proteolytically active PgtE. Human neutrophils interacted less with serum-opsonized FITC-stained S. enterica 14028R than with the isogenic ?pgtE strain, as analyzed by flow cytometry. In conclusion, cleavage of B and H by PgtE, together with C3 cleavage, affects the C3-mediated recognition of S. enterica by human neutrophils, thus thwarting the immune protection against Salmonella. PMID:25705210

  3. The complement system and adverse pregnancy outcomes.

    PubMed

    Regal, Jean F; Gilbert, Jeffrey S; Burwick, Richard M

    2015-09-01

    Adverse pregnancy outcomes significantly contribute to morbidity and mortality for mother and child, with lifelong health consequences for both. The innate and adaptive immune system must be regulated to insure survival of the fetal allograft, and the complement system is no exception. An intact complement system optimizes placental development and function and is essential to maintain host defense and fetal survival. Complement regulation is apparent at the placental interface from early pregnancy with some degree of complement activation occurring normally throughout gestation. However, a number of pregnancy complications including early pregnancy loss, fetal growth restriction, hypertensive disorders of pregnancy and preterm birth are associated with excessive or misdirected complement activation, and are more frequent in women with inherited or acquired complement system disorders or complement gene mutations. Clinical studies employing complement biomarkers in plasma and urine implicate dysregulated complement activation in components of each of the adverse pregnancy outcomes. In addition, mechanistic studies in rat and mouse models of adverse pregnancy outcomes address the complement pathways or activation products of importance and allow critical analysis of the pathophysiology. Targeted complement therapeutics are already in use to control adverse pregnancy outcomes in select situations. A clearer understanding of the role of the complement system in both normal pregnancy and complicated or failed pregnancy will allow a rational approach to future therapeutic strategies for manipulating complement with the goal of mitigating adverse pregnancy outcomes, preserving host defense, and improving long term outcomes for both mother and child. PMID:25802092

  4. The C-type lectin OCILRP2 costimulates EL4 T cell activation via the DAP12-Raf-MAP kinase pathway.

    PubMed

    Lou, Qiang; Zhang, Wei; Liu, Guangchao; Ma, Yuanfang

    2014-01-01

    OCILRP2 is a typical Type-II transmembrane protein that is selectively expressed in activated T lymphocytes, dendritic cells, and B cells and functions as a novel co-stimulator of T cell activation. However, the signaling pathways underlying OCILRP2 in T cell activation are still not completely understood. In this study, we found that the knockdown of OCILRP2 expression with shRNA or the blockage of its activity by an anti-OCILRP2 antagonist antibody reduced CD3/CD28-costimulated EL4 T cell viability and IL-2 production, inhibit Raf1, MAPK3, and MAPK8 activation, and impair NFAT and NF-?B transcriptional activities. Furthermore, immunoprecipitation results indicated that OCILRP2 could interact with the DAP12 protein, an adaptor containing an intracellular ITAM motif that can transduce signals to induce MAP kinase activation for T cell activation. Our data reveal that after binding with DAP12, OCILRP2 activates the Raf-MAP kinase pathways, resulting in T cell activation. PMID:25411776

  5. Identification of mannose-binding lectin as a mechanism in progressive immunoglobulin A nephropathy

    PubMed Central

    Shi, Beili; Wang, Ling; Mou, Shan; Zhang, Minfang; Wang, Qin; Qi, Chaojun; Cao, Liou; Che, Xiajing; Fang, Wei; Gu, Leyi; Yan, Yucheng; Qian, Jiaqi; Ni, Zhaohui

    2015-01-01

    Immunoglobulin A nephropathy (IgAN), the pathogenesis of which remained still unclear is one of the leading courses of end-stage renal disease in approximately 50% affected patients. On the basis of several researches, the activation of complement mannose-binding lectin (MBL) pathway might be the underlying mechanism in disease progress. In order to investigate the relationship between MBL pathway and IgAN, we discussed the MBL gene polymorphism as well as its expressed level in serum, urine and renal parenchymal, with renal outcome in IgAN patients. The significantly down-regulated expression of MBL was discovered, which may serve as a potential urinary biomarker in progressive IgAN according to the results of difference in gel electrophoresis and matrix-assisted laser desorption/ionization time of flight mass spectrometry. The single nucleotide polymorphisms of MBL gene in promoter and exon region were found and confirmed relating with the poor prognosis of progressive IgAN patients. As a result, the deficient activation of MBL pathway caused by the mutation of MBL accompanied with low expressed level of MBL in serum might be the potential inspiring regulation in IgAN, and will attract a promising insight in remedy of IgAN to inhibit further progress. PMID:25973081

  6. Meningococcal disease and the complement system

    PubMed Central

    Lewis, Lisa A; Ram, Sanjay

    2014-01-01

    Despite considerable advances in the understanding of the pathogenesis of meningococcal disease, this infection remains a major cause of morbidity and mortality globally. The role of the complement system in innate immune defenses against invasive meningococcal disease is well established. Individuals deficient in components of the alternative and terminal complement pathways are highly predisposed to invasive, often recurrent meningococcal infections. Genome-wide analysis studies also point to a central role for complement in disease pathogenesis. Here we review the pathophysiologic events pertinent to the complement system that accompany meningococcal sepsis in humans. Meningococci use several often redundant mechanisms to evade killing by human complement. Capsular polysaccharide and lipooligosaccharide glycan composition play critical roles in complement evasion. Some of the newly described protein vaccine antigens interact with complement components and have sparked considerable research interest. PMID:24104403

  7. Legume Lectins: I. Immunological Cross-Reactions between the Enzymic Lectin from Mung Beans and other Well Characterized Legume Lectins.

    PubMed

    Hankins, C N; Kindinger, J I; Shannon, L M

    1979-07-01

    A number of well characterized legume lectins including the enzymic lectin from Vigna radiata were examined for immunological relatedness. The immunological cross-reactions observed indicate that most of the legume lectins, including Vigna lectin, are evolutionarily closely related proteins. The possibility that these proteins are homologs with enzymic functions is discussed. PMID:16660894

  8. Mannan-Binding Lectin Is Involved in the Protection against Renal Ischemia/Reperfusion Injury by Dietary Restriction.

    PubMed

    Shushimita, Shushimita; van der Pol, Pieter; W F de Bruin, Ron; N M Ijzermans, Jan; van Kooten, Cees; Dor, Frank J M F

    2015-01-01

    Preoperative fasting and dietary restriction offer robust protection against renal ischemia/reperfusion injury (I/RI) in mice. We recently showed that Mannan-binding lectin (MBL), the initiator of the lectin pathway of complement activation, plays a pivotal role in renal I/RI. Based on these findings, we investigated the effect of short-term DR (30% reduction of total food intake) or three days of water only fasting on MBL in 10-12 weeks old male C57/Bl6 mice. Both dietary regimens significantly reduce the circulating levels of MBL as well as its mRNA expression in liver, the sole production site of MBL. Reconstitution of MBL abolished the protection afforded by dietary restriction, whereas in the fasting group the protection persisted. These data show that modulation of MBL is involved in the protection against renal I/RI induced by dietary restriction, and suggest that the mechanisms of protection induced by dietary restriction and fasting may be different. PMID:26367533

  9. Mannan-Binding Lectin Is Involved in the Protection against Renal Ischemia/Reperfusion Injury by Dietary Restriction

    PubMed Central

    Shushimita, Shushimita; van der Pol, Pieter; W.F. de Bruin, Ron; N. M. Ijzermans, Jan; van Kooten, Cees; Dor, Frank J. M. F.

    2015-01-01

    Preoperative fasting and dietary restriction offer robust protection against renal ischemia/reperfusion injury (I/RI) in mice. We recently showed that Mannan-binding lectin (MBL), the initiator of the lectin pathway of complement activation, plays a pivotal role in renal I/RI. Based on these findings, we investigated the effect of short-term DR (30% reduction of total food intake) or three days of water only fasting on MBL in 10–12 weeks old male C57/Bl6 mice. Both dietary regimens significantly reduce the circulating levels of MBL as well as its mRNA expression in liver, the sole production site of MBL. Reconstitution of MBL abolished the protection afforded by dietary restriction, whereas in the fasting group the protection persisted. These data show that modulation of MBL is involved in the protection against renal I/RI induced by dietary restriction, and suggest that the mechanisms of protection induced by dietary restriction and fasting may be different. PMID:26367533

  10. Analysis of common bean expressed sequence tags identifies sulfur metabolic pathways active in seed and sulfur-rich proteins highly expressed in the absence of phaseolin and major lectins

    PubMed Central

    2011-01-01

    Background A deficiency in phaseolin and phytohemagglutinin is associated with a near doubling of sulfur amino acid content in genetically related lines of common bean (Phaseolus vulgaris), particularly cysteine, elevated by 70%, and methionine, elevated by 10%. This mostly takes place at the expense of an abundant non-protein amino acid, S-methyl-cysteine. The deficiency in phaseolin and phytohemagglutinin is mainly compensated by increased levels of the 11S globulin legumin and residual lectins. Legumin, albumin-2, defensin and albumin-1 were previously identified as contributing to the increased sulfur amino acid content in the mutant line, on the basis of similarity to proteins from other legumes. Results Profiling of free amino acid in developing seeds of the BAT93 reference genotype revealed a biphasic accumulation of gamma-glutamyl-S-methyl-cysteine, the main soluble form of S-methyl-cysteine, with a lag phase occurring during storage protein accumulation. A collection of 30,147 expressed sequence tags (ESTs) was generated from four developmental stages, corresponding to distinct phases of gamma-glutamyl-S-methyl-cysteine accumulation, and covering the transitions to reserve accumulation and dessication. Analysis of gene ontology categories indicated the occurrence of multiple sulfur metabolic pathways, including all enzymatic activities responsible for sulfate assimilation, de novo cysteine and methionine biosynthesis. Integration of genomic and proteomic data enabled the identification and isolation of cDNAs coding for legumin, albumin-2, defensin D1 and albumin-1A and -B induced in the absence of phaseolin and phytohemagglutinin. Their deduced amino acid sequences have a higher content of cysteine than methionine, providing an explanation for the preferential increase of cysteine in the mutant line. Conclusion The EST collection provides a foundation to further investigate sulfur metabolism and the differential accumulation of sulfur amino acids in seed of common bean. Identification of sulfur-rich proteins whose levels are elevated in seed lacking phaseolin and phytohemagglutinin and sulfur metabolic genes may assist the improvement of protein quality. PMID:21615926

  11. Infectious diseases associated with complement deficiencies.

    PubMed Central

    Figueroa, J E; Densen, P

    1991-01-01

    The complement system consists of both plasma and membrane proteins. The former influence the inflammatory response, immune modulation, and host defense. The latter are complement receptors, which mediate the cellular effects of complement activation, and regulatory proteins, which protect host cells from complement-mediated injury. Complement activation occurs via either the classical or the alternative pathway, which converge at the level of C3 and share a sequence of terminal components. Four aspects of the complement cascade are critical to its function and regulation: (i) activation of the classical pathway, (ii) activation of the alternative pathway, (iii) C3 convertase formation and C3 deposition, and (iv) membrane attack complex assembly and insertion. In general, mechanisms evolved by pathogenic microbes to resist the effects of complement are targeted to these four steps. Because individual complement proteins subserve unique functional activities and are activated in a sequential manner, complement deficiency states are associated with predictable defects in complement-dependent functions. These deficiency states can be grouped by which of the above four mechanisms they disrupt. They are distinguished by unique epidemiologic, clinical, and microbiologic features and are most prevalent in patients with certain rheumatologic and infectious diseases. Ethnic background and the incidence of infection are important cofactors determining this prevalence. Although complement undoubtedly plays a role in host defense against many microbial pathogens, it appears most important in protection against encapsulated bacteria, especially Neisseria meningitidis but also Streptococcus pneumoniae, Haemophilus influenzae, and, to a lesser extent, Neisseria gonorrhoeae. The availability of effective polysaccharide vaccines and antibiotics provides an immunologic and chemotherapeutic rationale for preventing and treating infection in patients with these deficiencies. PMID:1889047

  12. A review of fish lectins.

    PubMed

    Ng, Tzi Bun; Fai Cheung, Randy Chi; Wing Ng, Charlene Cheuk; Fang, Evandro Fei; Wong, Jack Ho

    2015-01-01

    Lectins have been reported from various tissues of a diversity of fish species including Japanese eel, conger eel, electric eel, bighead carp, gibel carp, grass carp, Arabian Gulf catfish, channel catfish, blue catfish, catfish, pike perch, perch, powan, zebrafish, toxic moray, cobia fish, steelhead trout, Japanese trout, Atlantic salmon, chinook salmon, olive rainbow smelt, rainbow smelt, white-spotted charr, tilapia, blue gourami, ayu, Potca fish, Spanish mackerel, gilt head bream, tench, roach, rudd, common skate, and sea lamprey. The tissues from which the lectins were isolated comprise gills, eggs, electric organ, stomach, intestine, and liver. Lectins have also been isolated from skin, mucus serum, and plasma. The lectins differ in molecular weight, number of subunits, glycosylation, sugar binding specificity and amino acid sequence. Their activities include antimicrobial, antitumor, immunoregulatory and a role in development. PMID:25929869

  13. Complementizer Drop And IP Complementation in Japanese

    E-print Network

    Fukuda, Minoru

    2000-01-01

    The main purpose of the present paper is to provide a principled account for a phenomenon called "Complementizer Drop" in the dialects of Japanese and its related phenomena in teens of the head-raising approach without ...

  14. Complement and autoimmunity.

    PubMed

    Ballanti, Eleonora; Perricone, Carlo; Greco, Elisabetta; Ballanti, Marta; Di Muzio, Gioia; Chimenti, Maria Sole; Perricone, Roberto

    2013-07-01

    The complement system is a component of the innate immune system. Its main function was initially believed to be limited to the recognition and elimination of pathogens through direct killing or stimulation of phagocytosis. However, in recent years, the immunoregulatory functions of the complement system were demonstrated and it was determined that the complement proteins play an important role in modulating adaptive immunity and in bridging innate and adaptive responses. When the delicate mechanisms that regulate this sophisticated enzymatic system are unbalanced, the complement system may cause damage, mediating tissue inflammation. Dysregulation of the complement system has been involved in the pathogenesis and clinical manifestations of several autoimmune diseases, such as systemic lupus erythematosus, vasculitides, Sjögren's syndrome, antiphospholipid syndrome, systemic sclerosis, dermatomyositis, and rheumatoid arthritis. Complement deficiencies have been associated with an increased risk to develop autoimmune disorders. Because of its functions, the complement system is an attractive therapeutic target for a wide range of diseases. Up to date, several compounds interfering with the complement cascade have been studied in experimental models for autoimmune diseases. The main therapeutic strategies are inhibition of complement activation components, inhibition of complement receptors, and inhibition of membrane attack complex. At present, none of the available agents was proven to be both safe and effective for treatment of autoimmune diseases in humans. Nonetheless, data from preclinical studies and initial clinical trials suggest that the modulation of the complement system could constitute a viable strategy for the treatment of autoimmune conditions in the decades to come. PMID:23615835

  15. Complement therapy in atypical haemolytic uraemic syndrome (aHUS)

    PubMed Central

    Wong, Edwin K.S.; Goodship, Tim H.J.; Kavanagh, David

    2013-01-01

    Central to the pathogenesis of atypical haemolytic uraemic syndrome (aHUS) is over-activation of the alternative pathway of complement. Inherited defects in complement genes and autoantibodies against complement regulatory proteins have been described. The use of plasma exchange to replace non-functioning complement regulators and hyper-functional complement components in addition to the removal of CFH-autoantibodies made this the ‘gold-standard’ for management of aHUS. In the last 4 years the introduction of the complement inhibitor Eculizumab has revolutionised the management of aHUS. In this review we shall discuss the available literature on treatment strategies to date. PMID:23810412

  16. Lectin-resistant mutants of polarized epithelial cells.

    PubMed Central

    Meiss, H K; Green, R F; Rodriguez-Boulan, E J

    1982-01-01

    Two lectin-resistant mutants derived from Madin Darby canine kidney cells, with constitutive alterations in the asparagine-linked carbohydrate moieties, retained the characteristic structural and functional epithelial polarity of the parental cells. A ricin-resistant cell line was unable to incorporate galactose-sialic acid into glycoproteins and, from the pattern of cross-resistance to other lectins, appears to be different from previously described lines resistant to this lectin: the mutation in a concanavalin A-resistant line results, probably, in the production of defective carbohydrate cores of glycoproteins. In spite of glycosylation defects which result in an increased electrophoretic mobility of many cellular glycoproteins, both mutants retained the typical asymmetric structure of the plasma membrane (microvilli on the apical surface, junctional elements on the basolateral surface), functional tight junctions, and unidirectional active transport of electrolytes and water. These results suggest that glycoproteins with terminal galactose-sialic acid moieties are not critically involved in the development and maintenance of polarity in epithelial cells. The mutant cells, particularly the ricin-resistant line, exhibited, however, morphological and electrophysiological changes which suggest a quantitative effect of the mutations on intracellular traffic of membranes and tight junction formation. The cell lines described in this paper, the first lectin-resistant mutants of epithelial lineage, should prove useful tools for studying the peculiarities of glycosylating pathways in polarized cells. Images PMID:7177111

  17. Surviving Mousepox Infection Requires the Complement System

    PubMed Central

    Moulton, Elizabeth A.; Atkinson, John P.; Buller, R. Mark L

    2008-01-01

    Poxviruses subvert the host immune response by producing immunomodulatory proteins, including a complement regulatory protein. Ectromelia virus provides a mouse model for smallpox where the virus and the host's immune response have co-evolved. Using this model, our study investigated the role of the complement system during a poxvirus infection. By multiple inoculation routes, ectromelia virus caused increased mortality by 7 to 10 days post-infection in C57BL/6 mice that lack C3, the central component of the complement cascade. In C3?/? mice, ectromelia virus disseminated earlier to target organs and generated higher peak titers compared to the congenic controls. Also, increased hepatic inflammation and necrosis correlated with these higher tissue titers and likely contributed to the morbidity in the C3?/? mice. In vitro, the complement system in naďve C57BL/6 mouse sera neutralized ectromelia virus, primarily through the recognition of the virion by natural antibody and activation of the classical and alternative pathways. Sera deficient in classical or alternative pathway components or antibody had reduced ability to neutralize viral particles, which likely contributed to increased viral dissemination and disease severity in vivo. The increased mortality of C4?/? or Factor B?/? mice also indicates that these two pathways of complement activation are required for survival. In summary, the complement system acts in the first few minutes, hours, and days to control this poxviral infection until the adaptive immune response can react, and loss of this system results in lethal infection. PMID:19112490

  18. Investigations into polymorphisms within complement receptor type 1 (CD35) thought to protect against severe malaria 

    E-print Network

    Tetteh-Quarcoo, Patience Borkor

    2012-06-22

    The human immune-regulatory protein, complement receptor type 1 (CR1, CD35), occurs on erythrocytes where it serves as the immune adherence receptor. It interacts with C3b, C4b, C1q and mannan-binding lectin (MBL). It ...

  19. Lectin histochemistry of rabbit nephron.

    PubMed

    Castagnaro, M

    In order to investigate the usefulness of lectin histochemistry to detail nephronal segmentation we used 12 different biotinylated lectins (Con-A, DBA, GS-I, LCA, PNA, PWN, RCA-I, RCA-II, SWGA, SBA, UEA-I, and WGA) and Avidin-Biotin-Peroxidase (ABC) system on formalin-fixed and paraffin-embedded rabbit kidney sections. Each lectin, except UEA-I which did not stain any nephron structure, shows a different staining pattern along the nephron. Con-A, LCA, and RCA-I display a diffuse staining, while BS-I, RCA-II, SWGA, PWN, DBA, SBA and PNA are selective markers for specific nephron tracts. Furthermore, it is possible, according to the WGA binding pattern, to differentiate the convoluted part of the proximal tubule into two parts, named Segment A and Segment B. Lectin histochemistry on formalin-fixed and paraffin-embedded rabbit kidney sections displays a specific binding pattern along the rabbit nephron and shows interesting morphofunctional correlations. PMID:2091802

  20. Mechanism and function of complement factor H 

    E-print Network

    McIntosh, Nicola

    2014-06-28

    Factor H (FH) is a 155-kDa plasma protein that regulates the alternative pathway of the complement system. Its 20 CCP modules, of 51-62 amino acid residues each, are linked by short stretches (“linkers’) of three to eight ...

  1. Lectin cDNA and transgenic plants derived therefrom

    DOEpatents

    Raikhel, Natasha V. (Okemos, MI)

    2000-10-03

    Transgenic plants containing cDNA encoding Gramineae lectin are described. The plants preferably contain cDNA coding for barley lectin and store the lectin in the leaves. The transgenic plants, particularly the leaves exhibit insecticidal and fungicidal properties.

  2. Extreme High Prevalence of a Defective Mannose-Binding Lectin (MBL2) Genotype in Native South American West Andean Populations

    PubMed Central

    Sandoval, José Raul; Madsen, Hans O.; De Stefano, Gianfranco; Descailleaux-Dulanto, Jaime; Velazquez-Reinoso, Margarita; Ńique, Cesar; Fujita, Ricardo; Garred, Peter

    2014-01-01

    Mannose-binding lectin (MBL) is one of the five recognition molecules in the lectin complement pathway. Common variant alleles in the promoter and structural regions of the human MBL gene (MBL2) influence the stability and serum concentration of the protein. Epidemiological studies have shown that MBL2 variant alleles are associated with susceptibility to and the course of different types of infectious and inflammatory conditions. However, it has been suggested that these alleles are maintained in different populations due to selected advantages for carriers. We investigated the MBL2 allelic variation in indigenous individuals from 12 different West Central South America localities spanning from the desert coast, high altitude Andean plates and the Amazon tropical forest within the territories of Peru (n?=?249) (Departments of Loreto, Ucayali, Lambayeque, Junin, Ayacucho, Huancayo and Puno), and Ecuador (n?=?182) (Region of Esmeraldas and Santo Domingo de los Colorados). The distribution of MBL2 genotypes among the populations showed that the defective variant LYPB haplotype was very common. It showed the highest frequencies in Puno (Taquile (0.80), Amantani (0.80) and Anapia (0.58) islander communities of the Lake Titicaca), but lower frequencies of 0.22 in Junin (Central Andean highland) and Ucayali (Central Amazonian forest), as well as 0.27 and 0.24 in the Congoma and Cayapa/Chachis populations in the Amazonian forest in Ecuador were also observed. Our results suggest that the high prevalence of the MBL2 LYPB variant causing low levels of functional MBL in serum may mainly reflect a random distribution due to a population bottleneck in the founder populations. PMID:25313559

  3. Mannose-binding lectin impairs Leptospira activity through the inhibitory effect on the motility of cell.

    PubMed

    Xu, Jun; Guo, Yijie; Nakamura, Shuichi; Islam, Md Shafiqul; Tomioka, Rintaro; Yoneyama, Hiroshi; Isogai, Emiko

    2015-02-01

    Mannose-binding lectin (MBL) plays key role in lectin pathway of innate immunity, and shows the ability of triggering opsonization intermediately. Substantial increase in the serum level of MBL has been confirmed during leptospirosis, which caused by a pathogenic spirochete, Leptospira. Leptospira has a fascinating locomotion pattern, which simultaneously gyrating and swimming forward, such motility enables that Leptospira is difficult to be captured by immune cells if without any assistance. In this study, the effect of mannose-binding lectin to Leptospira was quantitatively investigated by measuring some kinematic parameters, to discover the mechanism behind MBL-mediated immune responses during leptospiral infection. The results showed that mannose-binding lectin is capable of inhibiting the motility of Leptospira by transforming free swimming cells to tumbled rotating cells, resulted in the increase number of rotating cells. Otherwise, decrease in rotation rate of rotating cell has been observed. However, the swimming speed of swimming Leptospira cells showed no observable change under the effect of MBL. The inhibitory effect were only valid in a relatively short period, Leptospira cells regained their original motility after 2 h. This raises an interesting topic that Leptospira is somehow able to escape from the inhibitory effect of MBL by dragging such unfavorable molecules toward to the cell end and eventually throwing it out. The inhibitory effect of MBL on the motility of Leptospira is expected to provide a new insight into lectin pathway. PMID:25644948

  4. Plant as a plenteous reserve of lectin

    PubMed Central

    Hivrale, AU; Ingale, AG

    2013-01-01

    Lectins are clusters of glycoproteins of nonimmune foundation that combine specifically and reversibly to carbohydrates, mainly the sugar moiety of glycoconjugates, resulting in cell agglutination and precipitation of glycoconjugates. They are universally distributed in nature, being established in plants, fungi, viruses, bacteria, crustacea, insects, and animals, but leguminacae plants are rich source of lectins. The present review reveals the structure, biological properties, and application of plant lectins. PMID:24084524

  5. Structure of an active N-terminal fragment of human complement factor H 

    E-print Network

    Hocking, Henry G.

    Factor H (FH) is a key regulator of the complement system, the principal molecular component of innate immunity in humans. The tight regulation of the alternative pathway (AP) of complement by FH occurs on host cells as ...

  6. Lectins and their application to clinical microbiology.

    PubMed Central

    Slifkin, M; Doyle, R J

    1990-01-01

    Lectins are generally associated with plant or animal components, selectively bind carbohydrates, and interact with procaryotic and eucaryotic cells. Lectins have various specificities that are associated with their ability to interact with acetylaminocarbohydrates, aminocarbohydrates, sialic acids, hexoses, pentoses, and as other carbohydrates. Microbial surfaces generally contain many of the sugar residues that react with lectins. Lectins are presently used in the clinical laboratory to type blood cells and are used in a wide spectrum of applications, including, in part, as carriers of chemotherapeutic agents, as mitogens, for fractionation of animal cells, and for investigations of cellular surfaces. Numerous studies have shown that lectins can be used to identify rapidly certain microorganisms isolated from a clinical specimen or directly in a clinical specimen. Lectins have been demonstrated to be important diagnostic reagents in the major realms of clinical microbiology. Thus, they have been applied in bacteriology, mycology, mycobacteriology, and virology for the identification and/or differentiation of various microorganisms. Lectins have been used successfully as epidemiologic as well as taxonomic markers of specific microorganisms. Lectins provide the clinical microbiologist with cost-effective and potential diagnostic reagents. This review describes the applications of lectins in clinical microbiology. Images PMID:2200603

  7. Engineering complement activation on polypropylene sulfide vaccine nanoparticles

    E-print Network

    Wikswo, John

    ]. Thereafter, all three pathways converge to activate complement component C3 with the release of C3a from. The anaphylatoxin and chemoattractant C3a [2] promotes rapid clearance of C3b-opsonized pathogens by invading

  8. Discrimination between Host and Pathogens by the Complement System

    PubMed Central

    Pangburn, Michael K.; Ferreira, Viviana P.; Cortes, Claudio

    2008-01-01

    Pathogen-specific complement activation requires direct recognition of pathogens and/or the absence of complement control mechanisms on their surfaces. Antibodies direct complement activation to potential pathogens recognized by the cellular innate and adaptive immune systems. Similarly, the plasma proteins MBL and ficolins direct activation to microorganisms expressing common carbohydrate structures. The absence of complement control proteins permits amplification of complement by the alternative pathway on any unprotected surface. The importance of complement recognition molecules (MBL, ficolins, factor H, C3, C1q, properdin, and others) to human disease are becoming clear as analysis of genetic data and knock out animals reveals links between complement proteins and specific diseases. PMID:19388159

  9. Studies on Complement

    E-print Network

    Sherwood, Noble P.

    1921-01-01

    the death of the animals some 48 hours afterwards. The complement content of normal dog serum was observed to vary from one-third to one-twelfth that of guinea-pig serum. The comple- ment content of individual dogs showed a similar variation when... the serum was titrated from time to time. In the animals suffering from chloroform poisoning, the complement content dropped to one- forty-fifth that of guinea-pig serum in 46 hours, just before the death of the animals. Dick also produced destruction...

  10. Recent insights into structures and functions of C-type lectins in the immune system

    PubMed Central

    Drickamer, Kurt; Taylor, Maureen E

    2015-01-01

    The majority of the C-type lectin-like domains in the human genome likely to bind sugars have been investigated structurally, although novel mechanisms of sugar binding are still being discovered. In the immune system, adhesion and endocytic receptors that bind endogenous mammalian glycans are often conserved, while pathogen-binding C-type lectins on cells of the innate immune system are more divergent. Lack of orthology between some human and mouse receptors, as well as overlapping specificities of many receptors and formation of receptor hetero-oligomers, can make it difficult to define the roles of individual receptors. There is good evidence that C-type lectins initiate signalling pathways in several different ways, but this function remains the least well understood from a mechanistic perspective. PMID:26163333

  11. Mannose-binding Lectin (MBL) as a susceptible host factor influencing Indian Visceral Leishmaniasis.

    PubMed

    Mishra, Anshuman; Antony, Justin S; Gai, Prabhanjan; Sundaravadivel, Pandarisamy; Van, Tong Hoang; Jha, Aditya Nath; Singh, Lalji; Velavan, Thirumalaisamy P; Thangaraj, Kumarasamy

    2015-12-01

    Visceral Leishmaniasis (VL), caused by Leishmania donovani is endemic in the Indian sub-continent. Mannose-binding Lectin (MBL) is a complement lectin protein that binds to the surface of Leishmania promastigotes and results in activation of the complement lectin cascade. We utilized samples of 218 VL patients and 215 healthy controls from an Indian population. MBL2 functional variants were genotyped and the circulating MBL serum levels were measured. MBL serum levels were elevated in patients compared to the healthy controls (adjusted P=0.007). The MBL2 promoter variants -78C/T and +4P/Q were significantly associated with relative protection to VL (-78C/T, OR=0.7, 95% CI=0.5-0.96, adjusted P=0.026 and +4P/Q, OR=0.66, 95% CI=0.48-0.9, adjusted P=0.012). MBL2*LYQA haplotypes occurred frequently among controls (OR=0.69, 95% CI=0.5-0.97, adjusted P=0.034). MBL recognizes Leishmania and plays a relative role in establishing L. donovani infection and subsequent disease progression. In conclusion, MBL2 functional variants were associated with VL. PMID:26297290

  12. Activated Complement Factors as Disease Markers for Sepsis

    PubMed Central

    Charchaflieh, Jean; Rushbrook, Julie; Worah, Samrat; Zhang, Ming

    2015-01-01

    Sepsis is a leading cause of death in the United States and worldwide. Early recognition and effective management are essential for improved outcome. However, early recognition is impeded by lack of clinically utilized biomarkers. Complement factors play important roles in the mechanisms leading to sepsis and can potentially serve as early markers of sepsis and of sepsis severity and outcome. This review provides a synopsis of recent animal and clinical studies of the role of complement factors in sepsis development, together with their potential as disease markers. In addition, new results from our laboratory are presented regarding the involvement of the complement factor, mannose-binding lectin, in septic shock patients. Future clinical studies are needed to obtain the complete profiles of complement factors/their activated products during the course of sepsis development. We anticipate that the results of these studies will lead to a multipanel set of sepsis biomarkers which, along with currently used laboratory tests, will facilitate earlier diagnosis, timely treatment, and improved outcome. PMID:26420913

  13. Complement activation promotes muscle inflammation during modified muscle use

    NASA Technical Reports Server (NTRS)

    Frenette, J.; Cai, B.; Tidball, J. G.

    2000-01-01

    Modified muscle use can result in muscle inflammation that is triggered by unidentified events. In the present investigation, we tested whether the activation of the complement system is a component of muscle inflammation that results from changes in muscle loading. Modified rat hindlimb muscle loading was achieved by removing weight-bearing from the hindlimbs for 10 days followed by reloading through normal ambulation. Experimental animals were injected with the recombinant, soluble complement receptor sCR1 to inhibit complement activation. Assays for complement C4 or factor B in sera showed that sCR1 produced large reductions in the capacity for activation of the complement system through both the classical and alternative pathways. Analysis of complement C4 concentration in serum in untreated animals showed that the classical pathway was activated during the first 2 hours of reloading. Analysis of factor B concentration in untreated animals showed activation of the alternative pathway at 6 hours of reloading. Administration of sCR1 significantly attenuated the invasion of neutrophils (-49%) and ED1(+) macrophages (-52%) that occurred in nontreated animals after 6 hours of reloading. The presence of sCR1 also reduced significantly the degree of edema by 22% as compared to untreated animals. Together, these data show that increased muscle loading activated the complement system which then briefly contributes to the early recruitment of inflammatory cells during modified muscle loading.

  14. Elevated Serum Mannose-Binding Lectin Levels Are Associated with Poor Outcome After Acute Ischemic Stroke in Patients with Type 2 Diabetes.

    PubMed

    Song, Fang-Yu; Wu, Meng-Hai; Zhu, Li-Hua; Zhang, Zhi-Qiang; Qi, Qin-De; Lou, Chang-Li

    2015-12-01

    The activation of the complement system may be involved in the pathology of stroke and type 2 diabetes (T2DM). We therefore evaluated the long-term prognostic value of early measurement of serum mannose-binding lectin (MBL) levels, an activator of the complement system, in Chinese T2DM with acute ischemic stroke (AIS). Serum MBL levels were determined in T2DM patients with AIS (N?=?188). The adjudicated end points were 1-year functional outcomes and mortality. The prognostic value of MBL was compared with the National Institutes of Health Stroke Scale score and with other known outcome predictors. Patients with an unfavorable outcomes and nonsurvivors had significantly increased MBL levels on admission (P?pathways leading to complement activation warrant further exploration as potential therapeutic targets to improve the prognosis for these patients. PMID:25341475

  15. Complement Activation and Inhibition in Retinal Diseases.

    PubMed

    Kleinman, Mark E; Ambati, Jayakrishna

    2016-01-01

    Within the past several decades, a brigade of dedicated researchers from around the world has provided essential insights into the critical niche of immune-mediated inflammation in the pathogenesis of age-related macular degeneration (AMD). Yet, the question has lingered as to whether disease-initiating events are more or less dependent on isolated immune-related responses, unimpeded inflammation, endogenous pathways of age-related cell senescence and oxidative stress, or any of the other numerous molecular derangements that have been identified in the natural history of AMD. There is now an abundant cache of data signifying immune system activation as an impetus in the pathogenesis of this devastating condition. Furthermore, recent rigorous investigations have revealed multiple inciting factors, including several important complement-activating components, thus creating a new array of disease-modulating targets for the research and development of molecular therapeutic interventions. While the precise in vivo effects of complement activation and inhibition in the progression and treatment of AMD remain to be determined, ongoing clinical trials of the first generation of complement-targeted therapeutics are hoped to yield critical data on the contribution of this pathway to the disease process. PMID:26501209

  16. Study of complement regulatory factor H based on Forster resonance energy transfer and investigation of disease-linked genetic variants 

    E-print Network

    Pechtl, Isabell C.

    2010-01-01

    The plasma protein complement factor H (fH, 155 kDa) regulates the activity of the alternative pathway of complement activation. Factor H is monomeric, and its 20 CCP modules are arranged in a predominantly elongated ...

  17. Complementing Gender Analysis Methods.

    PubMed

    Kumar, Anant

    2016-01-01

    The existing gender analysis frameworks start with a premise that men and women are equal and should be treated equally. These frameworks give emphasis on equal distribution of resources between men and women and believe that this will bring equality which is not always true. Despite equal distribution of resources, women tend to suffer and experience discrimination in many areas of their lives such as the power to control resources within social relationships, and the need for emotional security and reproductive rights within interpersonal relationships. These frameworks believe that patriarchy as an institution plays an important role in women's oppression, exploitation, and it is a barrier in their empowerment and rights. Thus, some think that by ensuring equal distribution of resources and empowering women economically, institutions like patriarchy can be challenged. These frameworks are based on proposed equality principle which puts men and women in competing roles. Thus, the real equality will never be achieved. Contrary to the existing gender analysis frameworks, the Complementing Gender Analysis framework proposed by the author provides a new approach toward gender analysis which not only recognizes the role of economic empowerment and equal distribution of resources but suggests to incorporate the concept and role of social capital, equity, and doing gender in gender analysis which is based on perceived equity principle, putting men and women in complementing roles that may lead to equality. In this article the author reviews the mainstream gender theories in development from the viewpoint of the complementary roles of gender. This alternative view is argued based on existing literature and an anecdote of observations made by the author. While criticizing the equality theory, the author offers equity theory in resolving the gender conflict by using the concept of social and psychological capital. PMID:25941756

  18. Weak Protein-Protein Interactions in Lectins: The Crystal Structure of a Vegetative Lectin from the

    E-print Network

    Hamelryck, Thomas

    - sent, the crystal structures of 21 native or sugar- E-mail address of the corresponding author: lievenWeak Protein-Protein Interactions in Lectins: The Crystal Structure of a Vegetative Lectin from a role in the regulation of receptor crosslinking and subsequent signal transduction. The crystal

  19. 21 CFR 864.9550 - Lectins and protectins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Manufacture Blood and Blood Products § 864.9550 Lectins and protectins. (a) Identification. Lectins and protectins are proteins derived from plants and lower animals that cause cell agglutination in the presence of certain antigens. These...

  20. 21 CFR 864.9550 - Lectins and protectins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Manufacture Blood and Blood Products § 864.9550 Lectins and protectins. (a) Identification. Lectins and protectins are proteins derived from plants and lower animals that cause cell agglutination in the presence of certain antigens. These...

  1. Epidemiological characterization of Neisseria gonorrhoeae by lectins.

    PubMed Central

    Schalla, W O; Whittington, W L; Rice, R J; Larsen, S A

    1985-01-01

    A total of 101 isolates of penicillinase-producing and non-penicillinase-producing Neisseria gonorrhoeae with known nutritional requirements, plasmid content, and serovars, were examined for lectin agglutination patterns. These isolates were from outbreaks in Georgia, California, Hawaii, and Pennsylvania. Cell suspensions made from 16- to 18-h cultures were mixed with 14 different lectins, and the resultant agglutination patterns were classified as agglutination groups. Among the 101 isolates tested, 24 different agglutination groups were demonstrated. Of the organisms tested, 55% were located in 3 of the 24 groups, and 86% of the isolates reacted with the lectins Trichosanthes kinlowii, Griffonia simplicifolia I, peanut agglutinin, soybean agglutinin, potato agglutinin, and wheat germ agglutinin. One isolate did not react with peanut or potato agglutinin, five isolates lacked reactivity with potato agglutinin, and six isolates did not react with wheat germ agglutinin. Of the wheat germ-negative isolates, four were from Pennsylvania and were identical with regard to auxotype, plasmid content, serovar, and lectin group. The other two wheat germ-negative isolates were from California and were unrelated by the same criteria to the four Pennsylvania isolates and to each other. Among the isolates tested, there were no differences in lectin groups with regard to the sex of the patient. In the Georgia collection, agglutination with one lectin group was confined to isolates of serogroup IA. This association was not observed for the other geographic areas. Some isolates showing identical auxotype, plasmid content, and serovars could be differentiated based on lectin agglutination patterns, whereas other isolates were identical by all testing criteria. PMID:3930560

  2. Lectin affinity chromatography of glycolipids

    SciTech Connect

    Torres, B.V.; Smith, D.F.

    1987-05-01

    Since glycolipids (GLs) are either insoluble or form mixed micelles in water, lectin affinity chromatography in aqueous systems has not been applied to their separation. They have overcome this problem by using tetrahydrofuran (THF) in the mobile phase during chromatography. Affinity columns prepared with the GalNAc-specific Helix pomatia agglutinin (HPA) and equilibrated in THF specifically bind the (/sup 3/H)oligosaccharide derived from Forssman GL indicating that the immobilized HPA retained its carbohydrate-binding specificity in this solvent. Intact Forssman GL was bound by the HPA-column equilibrated in THF and was specifically eluted with 0.1 mg/ml GalNAc in THF. Purification of the Forssman GL was achieved when a crude lipid extract of sheep erythrocyte membranes was applied to the HPA-column in THF. Non-specifically bound GLs were eluted from the column using a step gradient of aqueous buffer in THF, while the addition of GalNAc was required to elute the specifically bound GLs. Using this procedure the A-active GLs were purified from a crude lipid extract of type A human erythrocytes in a single chromatographic step. The use of solvents that maintain carbohydrate-binding specificity and lipid solubility will permit the application of affinity chromatography on immobilized carbohydrate-binding proteins to intact GLs.

  3. Purification and characterization of Dolichos lablab lectin.

    PubMed

    Mo, H; Meah, Y; Moore, J G; Goldstein, I J

    1999-02-01

    The mannose/glucose-binding Dolichos lablab lectin (designated DLL) has been purified from seeds of Dolichos lablab (hyacinth bean) to electrophoretic homogeneity by affinity chromatography on an ovalbumin-Sepharose 4B column. The purified lectin gave a single symmetric protein peak with an apparent molecular mass of 67 kDa on gel filtration chromatography, and five bands ranging from 10 kDa to 22 kDa upon SDS-PAGE. N-Terminal sequence analysis of these bands revealed subunit heterogeneity due to posttranslational proteolytic truncation at different sites mostly at the carboxyl terminus. The carbohydrate binding properties of the purified lectin were investigated by three different approaches: hemagglutination inhibition assay, quantitative precipitation inhibition assay, and ELISA. On the basis of these studies, it is concluded that the Dolichos lablab lectin has neither an extended carbohydrate combining site, nor a hydrophobic binding site adjacent to it. The carbohydrate combining site of DLL appears to most effectively accommodate a nonreducing terminal alpha-d-mannosyl unit, and to be complementary to the C-3, C-4, and C-6 equatorial hydroxyl groups of alpha-d-mannopyranosyl and alpha-d-glucopyranosyl residues. DLL strongly precipitates murine IgM but not IgG, and the recent finding that this lectin interacts specifically with NIH 3T3 fibroblasts transfected with the Flt3 tyrosine kinase receptor and preserves human cord blood stem cells and progenitors in a quiescent state for prolonged periods in culture, make this lectin a valuable tool in biomedical research. PMID:9949194

  4. Complement Inhibitor Eculizumab in Atypical Hemolytic Uremic Syndrome

    PubMed Central

    Acham-Roschitz, Birgit; Frémeaux-Bacchi, Veronique; Kirschfink, Michael; Zipfel, Peter F.; Roedl, Siegfried; Vester, Udo; Ring, Ekkehard

    2009-01-01

    Background and objectives: Atypical hemolytic uremic syndrome (aHUS) is associated with a congenital or acquired dysregulation of the complement alternative pathway that leads to continuous complement activation on host cells causing inflammation and damage. Eculizumab, a humanized mAb against complement protein C5, inhibits activation of the terminal complement pathway. Design, setting, participants, & measurements: We report an adolescent with relapsing unclassified aHUS. On admission, a high plasma creatinine level indicated a poor prognosis, and hemodialysis had to be started. Plasma exchanges were initially effective against the microangiopathic hemolytic activity and allowed a temporary improvement of renal function with termination of hemodialysis after 7 wk. Subsequently, plasma exchanges (three times per week) failed to prevent ongoing aHUS activity and progressive renal failure. After 12 wk, aHUS treatment was switched to eculizumab. Results: Eculizumab was effective in terminating the microangiopathic hemolytic process in two aHUS relapses; however, after normalization of complement activity, aHUS recurred and ultimately led to anuric end-stage renal failure. Conclusions: In this patient, complement inhibition by eculizumab temporarily terminated the microangiopathic hemolytic activity. Nevertheless, renal damage as a result of preceding and subsequent aHUS activity resulted in end-stage renal failure; therefore, therapeutic success may depend on early administration of eculizumab. The optimal duration of treatment may be variable and remains to be determined. PMID:19556379

  5. Role of Lectins in Plant-Microorganism Interactions

    PubMed Central

    Pueppke, Steven G.; Bauer, Wolfgang D.; Keegstra, Kenneth; Ferguson, Ardene L.

    1978-01-01

    Three different assay procedures have been used to quantitate the levels of soybean (Glycine max [L.] Merr.) lectin in various tissues of soybean plants. The assays used were a standard hemagglutination assay, a radioimmunoassay, and an isotope dilution assay. Most of the lectin in seeds was found in the cotyledons, but lectin was also detected in the embryo axis and the seed coat. Soybean lectin was present in all of the tissues of young seedlings, but decreased as the plants matured and was not detectable in plants older than 2 to 3 weeks. Soybean lectin isolated from seeds of several soybean varieties were identical when compared by several methods. PMID:16660384

  6. COMPLEMENT FIXATION IN DISEASED TISSUES

    PubMed Central

    Burkholder, Peter M.

    1961-01-01

    An immunohistologic complement fixation test has been used in an effort to detect immune complexes in sections of kidney from rats injected with rabbit anti-rat kidney serum and in sections of biopsied kidneys from four humans with membranous glomerulonephritis. Sections of the rat and human kidneys were treated with fluorescein-conjugated anti-rabbit globulin or antihuman globulin respectively. Adjacent sections in each case were incubated first with fresh guinea pig serum and then in a second step were treated with fluorescein-conjugated antibodies against fixed guinea pig complement to detect sites of fixation of the complement. It was demonstrated that the sites of rabbit globulin in glomerular capillary walls of the rat kidneys and the sites of localized human globulin in thickened glomerular capillary walls and swollen glomerular endothelial cells of the human kidneys were the same sites in which guinea pig complement was fixed in vitro. It was concluded from these studies that rabbit nephrotoxic antibodies localize in rat glomeruli in complement-fixing antigen-antibody complexes. Furthermore, it was concluded that the deposits of human globulin in the glomeruli of the human kidneys behaved like antibody globulin in complement-fixing antigen-antibody complexes. The significance of demonstrating complement-fixing immune complexes in certain diseased tissues is discussed in regard to determination of the causative role of allergic reactions in disease. PMID:19867205

  7. Mushroom Lectins: Specificity, Structure and Bioactivity Relevant to Human Disease

    PubMed Central

    Hassan, Mohamed Ali Abol; Rouf, Razina; Tiralongo, Evelin; May, Tom W.; Tiralongo, Joe

    2015-01-01

    Lectins are non-immunoglobulin proteins that bind diverse sugar structures with a high degree of selectivity. Lectins play crucial role in various biological processes such as cellular signaling, scavenging of glycoproteins from the circulatory system, cell–cell interactions in the immune system, differentiation and protein targeting to cellular compartments, as well as in host defence mechanisms, inflammation, and cancer. Among all the sources of lectins, plants have been most extensively studied. However, more recently fungal lectins have attracted considerable attention due to their antitumor, antiproliferative and immunomodulatory activities. Given that only 10% of mushroom species are known and have been taxonomically classified, mushrooms represent an enormous unexplored source of potentially useful and novel lectins. In this review we provide an up-to-date summary on the biochemical, molecular and structural properties of mushroom lectins, as well as their versatile applications specifically focusing on mushroom lectin bioactivity. PMID:25856678

  8. Mushroom lectins: specificity, structure and bioactivity relevant to human disease.

    PubMed

    Hassan, Mohamed Ali Abol; Rouf, Razina; Tiralongo, Evelin; May, Tom W; Tiralongo, Joe

    2015-01-01

    Lectins are non-immunoglobulin proteins that bind diverse sugar structures with a high degree of selectivity. Lectins play crucial role in various biological processes such as cellular signaling, scavenging of glycoproteins from the circulatory system, cell-cell interactions in the immune system, differentiation and protein targeting to cellular compartments, as well as in host defence mechanisms, inflammation, and cancer. Among all the sources of lectins, plants have been most extensively studied. However, more recently fungal lectins have attracted considerable attention due to their antitumor, antiproliferative and immunomodulatory activities. Given that only 10% of mushroom species are known and have been taxonomically classified, mushrooms represent an enormous unexplored source of potentially useful and novel lectins. In this review we provide an up-to-date summary on the biochemical, molecular and structural properties of mushroom lectins, as well as their versatile applications specifically focusing on mushroom lectin bioactivity. PMID:25856678

  9. Complement involvement in periodontitis: molecular mechanisms and rational therapeutic approaches

    PubMed Central

    Hajishengallis, George; Maekawa, Tomoki; Abe, Toshiharu; Hajishengallis, Evlambia; Lambris, John D.

    2015-01-01

    The complement system is a network of interacting fluid-phase and cell surface-associated molecules that trigger, amplify, and regulate immune and inflammatory signaling pathways. Dysregulation of this finely balanced network can destabilize host-microbe homeostasis and cause inflammatory tissue damage. Evidence from clinical and animal model-based studies suggests that complement is implicated in the pathogenesis of periodontitis, a polymicrobial community-induced chronic inflammatory disease that destroys the tooth-supporting tissues. This review discusses molecular mechanisms of complement involvement in the dysbiotic transformation of the periodontal microbiome and the resulting destructive inflammation, culminating in loss of periodontal bone support. These mechanistic studies have additionally identified potential therapeutic targets. In this regard, interventional studies in preclinical models have provided proof-of-concept for using complement inhibitors for the treatment of human periodontitis. PMID:26306443

  10. Structural analysis of a Dioclea sclerocarpa lectin: Study on the vasorelaxant properties of Dioclea lectins.

    PubMed

    Barroso-Neto, Ito L; Delatorre, Plinio; Teixeira, Claudener S; Correia, Jorge L A; Cajazeiras, Joăo B; Pereira, Ronniery I; Nascimento, Kyria S; Laranjeira, Eva P P; Pires, Alana F; Assreuy, Ana M S; Rocha, Bruno A M; Cavada, Benildo S

    2016-01-01

    Lectins are proteins that show a variety of biological activities. However, they share in common at least one domain capable of recognizing specific carbohydrates reversibly without changing its structure. The legume lectins family is the most studied family of plant lectins, in particular the Diocleinae subtribe, which possesses high degree of structural similarity, but variable biological activities. This variability lies in small differences that can be analyzed in studies based on structures. In particular, Dioclea sclerocarpa seed lectin (DSL) presents low ability to relax endothelialized rat aorta in comparison with other Dioclea lectins such as Dioclea violacea (DVL), Dioclea virgata (DvirL) and Dioclea rostrata (DRL). The DSL relaxation mechanism relies on nitric oxide production and carbohydrate recognition domain (CRD). This feature can be explained by structural differences, since DSL has a carbohydrate recognition domain design less favorable. In addition, the presence of a glutamate residue at position 205 proved to be a decisive factor for the low relaxant effect of Dioclea lectins. PMID:26499084

  11. Lectins modulate multi-walled carbon nanotubes cellular uptake in human epidermal keratinocytes.

    PubMed

    Zhang, Leshuai W; Monteiro-Riviere, Nancy A

    2010-03-01

    The development of nanomaterials for biomedical applications has attracted a great deal of attention. Carbon nanotubes may interact and cross cell membranes and serve as potential carriers for drug delivery studies. The reflection mode in the confocal laser scanning microscope was used to image multi-walled carbon nanotubes (MWCNT) in human neonatal epidermal keratinocytes (HEK) stained with the cytoskeleton protein F-actin. Scanning electron microscopy depicted tight binding of MWCNT on the plasma membrane of HEK, while some MWCNT were located in the cell. Since keratinocytes normally engulf melanosomes, we hypothesized that the melanocyte transfer pathway could be a potential route of entry into keratinocytes. Lectins are inhibitors of the melanosome transfer pathway was used to study the uptake of MWCNT in keratinocytes, to see if they played a role in reducing the cellular uptake of MWCNT in HEK. Three different lectins, Pisum sativum (PS), Lycopersicon esculentum (LE), and Tetragonolobus purpureas (TP) were used as a cocktail. The maximal concentrations of lectins that would be non-toxic to the HEK was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell viability assay. These studies confirmed that lectin cocktails (PS 5mug/ml, LE 25mug/ml and TP 25mug/ml) decreased MWCNT interaction at the cell surface and uptake. F-actin, a cytoskeleton protein, was used to visualize how the MWCNT interacted with the cytoskeleton in the cells. MWCNT traversed through the cells' cytoskeleton and the plasma membrane into adjacent keratinocytes. PMID:19913088

  12. Displacement Phenomena in Lectin Affinity Chromatography.

    PubMed

    Cho, Wonryeon

    2015-10-01

    The work described here examines displacement phenomena that play a role in lectin affinity chromatography and their potential to impact reproducibility. This was achieved using Lycopersicon esculentum lectin (LEL), a lectin widely used in monitoring cancer. Four small identical LEL columns were coupled in series to form a single affinity chromatography system with the last in the series connected to an absorbance detector. The serial affinity column set (SACS) was then loaded with human plasma proteins. At the completion of loading, the column set was disassembled, the four columns were eluted individually, the captured proteins were trypsin digested, the peptides were deglycosylated with PNGase F, and the parent proteins were identified through mass spectral analyses. Significantly different sets of glycoproteins were selected by each column, some proteins appearing to be exclusively bound to the first column while others were bound further along in the series. Clearly, sample displacement chromatography (SDC) occurs. Glycoproteins were bound at different places in the column train, identifying the presence of glycoforms with different affinity on a single glycoprotein. It is not possible to see these phenomena in the single column mode of chromatography. Moreover, low abundance proteins were enriched, which facilitates detection. The great advantage of this method is that it differentiates between glycoproteins on the basis of their binding affinity. Displacement phenomena are concluded to be a significant component of the separation mechanism in heavily loaded lectin affinity chromatography columns. This further suggests that care must be exercised in sample loading of lectin columns to prevent analyte displacement with nonretained proteins. PMID:26348026

  13. Depletion of specific cell populations by complement depletion.

    PubMed

    Dittel, Bonnie N

    2010-01-01

    The purification of immune cell populations is often required in order to study their unique functions. In particular, molecular approaches such as real-time PCR and microarray analysis require the isolation of cell populations with high purity. Commonly used purification strategies include fluorescent activated cell sorting (FACS), magnetic bead separation and complement depletion. Of the three strategies, complement depletion offers the advantages of being fast, inexpensive, gentle on the cells and a high cell yield. The complement system is composed of a large number of plasma proteins that when activated initiate a proteolytic cascade culminating in the formation of a membrane-attack complex that forms a pore on a cell surface resulting in cell death(1). The classical pathway is activated by IgM and IgG antibodies and was first described as a mechanism for killing bacteria. With the generation of monoclonal antibodies (mAb), the complement cascade can be used to lyse any cell population in an antigen-specific manner. Depletion of cells by the complement cascade is achieved by the addition of complement fixing antigen-specific antibodies and rabbit complement to the starting cell population. The cells are incubated for one hour at 37 degrees C and the lysed cells are subsequently removed by two rounds of washing. MAb with a high efficiency for complement fixation typically deplete 95-100% of the targeted cell population. Depending on the purification strategy for the targeted cell population, complement depletion can be used for cell purification or for the enrichment of cell populations that then can be further purified by a subsequent method. PMID:20139864

  14. Differentiation of Bacillus anthracis and other Bacillus species by lectins.

    PubMed Central

    Cole, H B; Ezzell, J W; Keller, K F; Doyle, R J

    1984-01-01

    Bacillus anthracis was agglutinated by several lectins, including those from Griffonia simplicifolia, Glycine max, Abrus precatorius, and Ricinus communis. Some strains of Bacillus cereus var. mycoides (B. mycoides) were strongly reactive with the lectin from Helix pomatia and weakly reactive with the G. max lectin. The differential interactions between Bacillus species and lectins afforded a means of distinguishing B. anthracis from other bacilli. B. cereus strains exhibited heterogeneity with respect to agglutination patterns by lectins but could readily be differentiated from B. anthracis and the related B. mycoides. Spores of B. anthracis and B. mycoides retained lectin receptors, although the heating of spores or vegetative cells at 100 degrees C resulted in a decrease in their ability to be specifically agglutinated. Fluorescein-conjugated lectin of G. max stained vegetative cells of B. anthracis uniformly, suggesting that the distribution of lectin receptors was continuous over the entire cellular surface. B. anthracis cells grown under conditions to promote the production of capsular poly(D-glutamyl peptide) were also readily agglutinated by the lectins, suggesting that the lectin reactive sites penetrate the polypeptide layer. Trypsin, subtilisin, lysozyme, and mutanolysin did not modify the reactivity of B. anthracis with the G. max agglutinin, although the same enzymes markedly diminished the interaction between the lectin and B. mycoides. Because the lectins which interact with B. anthracis are specific for alpha-D-galactose or 2-acetamido-2-deoxy-alpha-D-galactose residues, it is likely that the bacteria possess cell surface polymers which contain these sugars. Lectins may prove useful in the laboratory identification of B. anthracis and possibly other pathogenic Bacillus species, such as B. cereus. Images PMID:6418761

  15. Complement activation contributes to the anti-methicillin-resistant Staphylococcus aureus effect of natural anti-keratin antibody.

    PubMed

    An, Jingang; Li, Zhengxiao; Dong, Yingying; Wu, Jiawen; Ren, Jianwen

    2015-05-22

    Methicillin-resistant Staphylococcus aureus (MRSA) remains a major public health problem worldwide because of its strong resistance to a variety of antibiotics. Natural immunoglobulin (Ig) M antibodies have been reported to protect against microbial infections. In the present study, the function of a monoclonal natural anti-keratin antibody IgM (named 3B4) in MRSA infection was evaluated. The binding of 3B4 to MRSA was studied using immunofluorescence assay and flow cytometry (FCM). The binding of 3B4 to mannose-binding lectin (MBL) and complement activation were detected by ELISA. For the in vivo study, transgenic mice for the VH gene from 3B4 (TgVH 3B4) were used. After infection, the bacterial burden was examined in the kidney, spleen and enterocelia. Inflammatory cytokine levels and the neutrophil ratio in peritoneal lavage fluid (PLF) were assessed by ELISA and FCM, respectively. Additionally, the total serum hemolytic activity (CH50) in the early stage of infection was detected by ELISA. The results showed that 3B4 bound directly to MRSA and MBL, and the interaction between 3B4 and MRSA/MBL led to the activation of the classic and the MBL pathway in vitro. After 48 h of MRSA infection, the bacterial load in the kidney, spleen and enterocelia was significantly decreased in TgVH 3B4 mice (P < 0.05) compared with wild-type mice. Levels of IL-6, TNF-?, and IFN-? were increased after MRSA infection. The levels of IL-6 and TNF-? in TgVH 3B4 mice were decreased by 49.1% and 59.4% compared to wild-type mice. Additionally, the neutrophil ratio in the PLF of TgVH 3B4 mice was decreased by 65.9%. The CH50 value was significantly higher in TgVH 3B4 mice than in wild-type mice, indicating that 3B4 promoted the activation of the complement system in MRSA infected mice. The results reveal an important role of 3B4 in the anti-MRSA immune response, and the complement activation contributes to this effect. PMID:25862372

  16. Biological role of mannose binding lectin: From newborns to centenarians.

    PubMed

    Scorza, Manuela; Liguori, Renato; Elce, Ausilia; Salvatore, Francesco; Castaldo, Giuseppe

    2015-12-01

    Mannose binding lectin (MBL) is a protein of innate immunity that activates the complement and promotes opsonophagocytosis. The deficiency of MBL due to several common gene polymorphisms significantly enhances the risk of severe infections, particularly in the neonatal age and in childhood. On the contrary, the role of the protein in carcinogenesis and atherogenesis is still debated: MBL has a relevant role against neoplastic cells, but some studies described a protective effect of low levels of MBL toward breast cancer and a longer survival of lung cancer patients with a reduced MBL activity. Similarly, some studies concluded on the protective role of low levels of MBL toward cardiovascular diseases while other focused on a higher risk of myocardial infarction in subjects with a deficient activity of the protein. More recently, a role of MBL in the clearance of senescent cells emerged, and a study in two large cohorts of centenarians demonstrated that a high biological activity of the protein enhances the risk of autoimmune diseases. This body of data strongly suggests that the optimal levels of MBL activity depend on the age and on the environmental context of each subject. PMID:25783214

  17. Z .Biochimica et Biophysica Acta 1383 1998 936 Legume lectin structure

    E-print Network

    Hamelryck, Thomas

    lectin IV; GS-II, Griffonia simplicifolia lectin II; LOL, Lathyris ochrus lectin; LOL I, Lathyris ochrus isolectin I; LOL II, Lathyris ochrus isolectin II; PNA, peanut agglutinin; DBL, Dolichos biflorus seed

  18. Exploring the Innate Immune System: Using Complement-Medicated Cell Lysis in the Classroom

    ERIC Educational Resources Information Center

    Fuller, Kevin G.

    2008-01-01

    The protein complement pathway comprises an important part of the innate immunity. The use of serum to demonstrate complement-mediated destruction across a series of bacterial dilutions allows an instructor to introduce a number of important biological concepts such as bacterial growth, activation cascades, and adaptive versus innate immunity.

  19. Complement activation in the context of stem cells and tissue repair

    PubMed Central

    Schraufstatter, Ingrid U; Khaldoyanidi, Sophia K; DiScipio, Richard G

    2015-01-01

    The complement pathway is best known for its role in immune surveillance and inflammation. However, its ability of opsonizing and removing not only pathogens, but also necrotic and apoptotic cells, is a phylogenetically ancient means of initiating tissue repair. The means and mechanisms of complement-mediated tissue repair are discussed in this review. There is increasing evidence that complement activation contributes to tissue repair at several levels. These range from the chemo-attraction of stem and progenitor cells to areas of complement activation, to increased survival of various cell types in the presence of split products of complement, and to the production of trophic factors by cells activated by the anaphylatoxins C3a and C5a. This repair aspect of complement biology has not found sufficient appreciation until recently. The following will examine this aspect of complement biology with an emphasis on the anaphylatoxins C3a and C5a. PMID:26435769

  20. Complement activation in the context of stem cells and tissue repair.

    PubMed

    Schraufstatter, Ingrid U; Khaldoyanidi, Sophia K; DiScipio, Richard G

    2015-09-26

    The complement pathway is best known for its role in immune surveillance and inflammation. However, its ability of opsonizing and removing not only pathogens, but also necrotic and apoptotic cells, is a phylogenetically ancient means of initiating tissue repair. The means and mechanisms of complement-mediated tissue repair are discussed in this review. There is increasing evidence that complement activation contributes to tissue repair at several levels. These range from the chemo-attraction of stem and progenitor cells to areas of complement activation, to increased survival of various cell types in the presence of split products of complement, and to the production of trophic factors by cells activated by the anaphylatoxins C3a and C5a. This repair aspect of complement biology has not found sufficient appreciation until recently. The following will examine this aspect of complement biology with an emphasis on the anaphylatoxins C3a and C5a. PMID:26435769

  1. Role of C5b-9 complement complex and response gene to complement-32 (RGC-32) in cancer.

    PubMed

    Vlaicu, Sonia I; Tegla, Cosmin A; Cudrici, Cornelia D; Danoff, Jacob; Madani, Hassan; Sugarman, Adam; Niculescu, Florin; Mircea, Petru A; Rus, Violeta; Rus, Horea

    2013-05-01

    Complement system activation plays an important role in both innate and acquired immunity, with the activation of complement and the subsequent formation of C5b-9 terminal complement complex on cell membranes inducing target cell death. Recognition of this role for C5b-9 leads to the assumption that C5b-9 might play an antitumor role. However, sublytic C5b-9 induces cell cycle progression by activating signal transduction pathways and transcription factors in cancer cells, indicating a role in tumor promotion for this complement complex. The induction of the cell cycle by C5b-9 is dependent upon the activation of the phosphatidylinositol 3-kinase (PI3K)/Akt/FOXO1 and ERK1 pathways in a Gi protein-dependent manner. C5b-9 also induces response gene to complement (RGC)-32, a gene that plays a role in cell cycle promotion through activation of Akt and the CDC2 kinase. RGC-32 is expressed by tumor cells and plays a dual role in cancers, in that it has both a tumor suppressor role and tumor-promoting activity. Thus, through the activation of tumor cells, the C5b-9-mediated induction of the cell cycle plays an important role in tumor proliferation and oncogenesis. PMID:23247987

  2. Lectin cDNA and transgenic plants derived therefrom

    DOEpatents

    Raikhel, Natasha V. (Okemos, MI)

    1994-01-04

    Transgenic plants containing cDNA encoding Gramineae lectin are described. The plants preferably contain cDNA coding for barley lectin and store the lectin in the leaves. The transgenic plants, particularly the leaves exhibit insecticidal and fungicidal properties. GOVERNMENT RIGHTS This application was funded under Department of Energy Contract DE-AC02-76ER01338. The U.S. Government has certain rights under this application and any patent issuing thereon.

  3. Lectin cDNA and transgenic plants derived therefrom

    DOEpatents

    Raikhel, N.V.

    1994-01-04

    Transgenic plants containing cDNA encoding Gramineae lectin are described. The plants preferably contain cDNA coding for barley lectin and store the lectin in the leaves. The transgenic plants, particularly the leaves exhibit insecticidal and fungicidal properties. GOVERNMENT RIGHTS This application was funded under Department of Energy Contract DE-AC02-76ER01338. The U.S. Government has certain rights under this application and any patent issuing thereon. .

  4. Complementizer Agreement in Najdi Arabic

    E-print Network

    Lewis, Robert

    2013-08-13

    ONE INTRODUCTION 1.1 Introduction 1.2 Najdi Dialect and its Speakers 1.3 Grammatical Features of Najdi Arabic 1.3.1 Sounds of Najdi Arabic 1.3.2 Morphology of DPs 1.3.3 Pronouns 1.3.4 Agreement in Najdi Arabic 1.3.5 Word orders 1.3.6 Tense 1.3.7... Agreement 4.4 Conclusion vii CHAPTER FIVE TYPOLOGY OF COMPLEMENTIZER AGREEMENT 5.1 Introduction 5.2 Complementizer Agreement Properties in West Germanic 5.3 Conclusion CHAPTER SIX CONCLUSION 6.1 Conclusion viii LIST OF ABBREVIATIONS...

  5. Complement activation patterns in atypical haemolytic uraemic syndrome during acute phase and in remission.

    PubMed

    Volokhina, E B; Westra, D; van der Velden, T J A M; van de Kar, N C A J; Mollnes, T E; van den Heuvel, L P

    2015-08-01

    Atypical haemolytic uraemic syndrome (aHUS) is associated with (genetic) alterations in alternative complement pathway. Nevertheless, comprehensive evidence that the complement system in aHUS patients is more prone to activation is still lacking. Therefore, we performed a thorough analysis of complement activation in acute phase and in remission of this disease. Complement activation patterns of the aHUS patients in acute phase and in remission were compared to those of healthy controls. Background levels of complement activation products C3b/c, C3bBbP and terminal complement complex (TCC) were measured using enzyme-linked immunosorbent assay (ELISA) in ethylenediamine tetraacetic acid (EDTA) plasma. In vitro-triggered complement activation in serum samples was studied using zymosan-coating and pathway-specific assay. Furthermore, efficiencies of the C3b/c, C3bBbP and TCC generation in fluid phase during spontaneous activation were analysed. Patients with acute aHUS showed elevated levels of C3b/c (P?complement factor B mutation we illustrated normalization of complement activation during aHUS recovery. Serum samples from patients in remission showed normal in vitro patterns of complement activation and demonstrated normal kinetics of complement activation in the fluid phase. Our data indicate that while aHUS patients have clearly activated complement in acute phase of the disease, this is not the case in remission of aHUS. This knowledge provides important insight into complement regulation in aHUS and may have an impact on monitoring of these patients, particularly when using complement inhibition therapy. PMID:25079699

  6. Lectins discriminate between pathogenic and nonpathogenic South American trypanosomes

    SciTech Connect

    de Miranda Santos, I.K.; Pereira, M.E.

    1984-09-01

    Cell surface carbohydrates of Trypanosoma cruzi, Trypanosoma rangeli, and Trypanosoma conorhini were analyzed by a micro-agglutination assay employing 27 highly purified lectins and by binding assays using various /sup 125/I-labeled lectins. The following seven lectins discriminated between the trypanosomes: 1) tomato lectin (an N-acetyl-D-glucosamine-binding protein), both in purified form and as crude tomato juice; 2) Bauhinea purpurea and Sophora japonica lectins (both N-acetyl-D-galactosamine-binding proteins), which selectively agglutinated T. cruzi; 3) Vicia villosa (an N-acetyl-D-galactosamine-binding protein) which was specific for T. rangeli; 4) peanut lectin (a D-galactose-binding protein) both in purified form and as crude saline extract; and 5) Ulex europaeus and Lotus tetragonolobus (both L-fucose-binding proteins) lectins which reacted only with T. conorhini. Binding studies with 125I-labeled lectins were performed to find whether unagglutinated cells of the three different species of trypanosomes might have receptors for these lectins, in which case absence of agglutination could be due to a peculiar arrangement of the receptors. These assays essentially confirmed the agglutination experiments.

  7. Decidual expression and localization of human surfactant protein SP-A and SP-D, and complement protein C1q.

    PubMed

    Madhukaran, Shanmuga Priyaa; Kishore, Uday; Jamil, Kaiser; Choolani, Mahesh; Lu, Jinhua

    2015-08-01

    Surfactant proteins SP-A and SP-D, and complement protein C1q are soluble innate immune pattern recognizing molecules. SP-A, SP-D and C1q have an overall similar structure composed of an N-terminal triple-helical collagen region that is followed by a trimeric globular domain. While SP-A and SP-D belong to the collectin family (collagen containing lectin), C1q is the first recognition subcomponent of the classical pathway of the complement system. Recently, SP-A, SP-D and C1q have been considered to play important roles in early and late pregnancy. However, their expression in early human decidua has not been examined. Here, we investigated whether SP-A, SP-D and C1q are expressed within first trimester decidua in humans and their expression is associated with trophoblasts and decidual stromal cells. Decidual samples from women undergoing elective vaginal termination of pregnancy during first trimester were obtained from 25 subjects. Immunohistochemical studies using anti-human SP-A, anti-human SP-D and anti-human C1q antibodies were performed on decidual tissue sections along with anti-vimentin and cytokeratin-7 antibodies to identify stromal cells and trophoblasts. The expression was also examined by immunostaining and PCR using decidual and stromal cells. C1q expression was significantly higher when compared to SP-A and SP-D in the first trimester human decidua. Double immunostaining revealed that all stromal cells and trophoblasts expressed SP-A, SP-D and C1q, while only few invasive trophoblasts expressed C1q. Thus, expression of SP-A, SP-D and C1q in human decidua during first trimester suggests potential role of SP-A, SP-D and C1q during the early stages of pregnancy including implantation, trophoblast invasion and placental development. PMID:25829244

  8. Improvisation: A Complement to Curriculum

    ERIC Educational Resources Information Center

    Ronald, Green A.

    2006-01-01

    With the growth of standardized assessment benchmarks in both the public and private paradigms, testing performance matters to institutions more than ever. In an attempt to take as many hindering variables out of this process, such as test anxiety, socioeconomic influences, and latency in cognition, Improvisation: A Complement to Curriculum seeks…

  9. Membrane attack by complement: the assembly and biology of terminal complement complexes.

    PubMed

    Tegla, Cosmin A; Cudrici, Cornelia; Patel, Snehal; Trippe, Richard; Rus, Violeta; Niculescu, Florin; Rus, Horea

    2011-10-01

    Complement system activation plays an important role in both innate and acquired immunity. Activation of the complement and the subsequent formation of C5b-9 channels (the membrane attack complex) on the cell membranes lead to cell death. However, when the number of channels assembled on the surface of nucleated cells is limited, sublytic C5b-9 can induce cell cycle progression by activating signal transduction pathways and transcription factors and inhibiting apoptosis. This induction by C5b-9 is dependent upon the activation of the phosphatidylinositol 3-kinase/Akt/FOXO1 and ERK1 pathways in a Gi protein-dependent manner. C5b-9 induces sequential activation of CDK4 and CDK2, enabling the G1/S-phase transition and cellular proliferation. In addition, it induces RGC-32, a novel gene that plays a role in cell cycle activation by interacting with Akt and the cyclin B1-CDC2 complex. C5b-9 also inhibits apoptosis by inducing the phosphorylation of Bad and blocking the activation of FLIP, caspase-8, and Bid cleavage. Thus, sublytic C5b-9 plays an important role in cell activation, proliferation, and differentiation, thereby contributing to the maintenance of cell and tissue homeostasis. PMID:21850539

  10. Herbal complement inhibitors in the treatment of neuroinflammation: future strategy for neuroprotection.

    PubMed

    Kulkarni, Amod P; Kellaway, Laurie A; Kotwal, Girish J

    2005-11-01

    The upregulated complement system plays a damaging role in disorders of the central nervous system (CNS). The classical and alternate pathways are two major pathways activated in neuroinflammatory disorders such as Alzheimer's disease, multiple sclerosis, traumatic brain injury, spinal cord injury, HIV-associated dementia, Parkinson's disease, and mad cow disease. Failure of currently available anti-inflammatory agents, especially cyclooxygenase inhibitors, in offering significant neuroprotection in large epidemiologic clinical trials of CNS disorders suggests an urgent need for the development of new neuroprotective agents. The positive preclinical outcomes in treating CNS disorders by complement regulatory molecules, such as vaccinia virus complement control protein, suggest the possibility of using complement-inhibitory molecules as neuroprotective agents. Several active ingredients of herbal origin are found to have complement-inhibitory activity. These herbal ingredients along with other anti-inflammatory roles might be useful in treating neuroinflammation associated with CNS disorders. Active ingredients of herbal origin with complement inhibitory ingredients are summarized and classified according to their chemical nature and specificity towards the major pathways activating the complement system. The structure activity relationship of some specific examples is also discussed in this report. This information might be helpful in formulating a natural panacea against complement-mediated neuroinflammation. PMID:16387706

  11. Downregulation of Hsp70 inhibits apoptosis induced by sialic acid-binding lectin (leczyme).

    PubMed

    Tatsuta, Takeo; Hosono, Masahiro; Ogawa, Yukiko; Inage, Kyoko; Sugawara, Shigeki; Nitta, Kazuo

    2014-01-01

    Heat shock proteins (Hsps) are molecular chaperones that maintain homeostasis of organisms. In regards to the Hsps, many studies have investigated the structure, expression, localization and functions of Hsp70 and Hsc70 including expression in the glycosphingolipid-enriched microdomain (GEM) on the cell surface and involvement in cell death. Sialic acid-binding lectin (SBL) isolated from oocytes of Rana catesbeiana is a multifunctional protein which has lectin activity, ribonuclease activity and antitumor activity. SBL has potential as a new type of anticancer drug, since it causes cancer-selective induction of apoptosis by multiple signaling pathways in which RNA is its target; and the participation of the mitochondrial pathway and the endoplasmic reticulum (ER) stress-mediated pathway has been suggested. It has also been suggested that receptor(s) for SBL (SBLR) may exist in the GEM on the cell surface. In the present study, we studied the possible involvement of Hsp70 and Hsc70 in SBL-induced apoptosis. We showed that Hsp70 and Hsc70 were expressed on the P388 cell surface similar to SBLR, and their distribution in cells dramatically changed immediately prior to the execution of apoptosis following stimulation of SBL. Functional study of Hsp70 revealed that decreased expression of Hsp70 diminished the apoptosis induced by SBL. It is suggested that Hsp70 participates in the antitumor effect of SBL. PMID:24173532

  12. Plant Lectins: Wheat Defense Strategy Against Hessian Fly

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plants produce a variety of defense proteins, including lectins in response to attack by phytophagous insects. Ultrastructural studies reveal that binding to insect gut structures and resistance to proteolytic degradation by insect digestive enzymes are the two main prerequisites for the lectins to...

  13. Porifera Lectins: Diversity, Physiological Roles and Biotechnological Potential

    PubMed Central

    Gardčres, Johan; Bourguet-Kondracki, Marie-Lise; Hamer, Bojan; Batel, Renato; Schröder, Heinz C.; Müller, Werner E. G.

    2015-01-01

    An overview on the diversity of 39 lectins from the phylum Porifera is presented, including 38 lectins, which were identified from the class of demosponges, and one lectin from the class of hexactinellida. Their purification from crude extracts was mainly performed by using affinity chromatography and gel filtration techniques. Other protocols were also developed in order to collect and study sponge lectins, including screening of sponge genomes and expression in heterologous bacterial systems. The characterization of the lectins was performed by Edman degradation or mass spectrometry. Regarding their physiological roles, sponge lectins showed to be involved in morphogenesis and cell interaction, biomineralization and spiculogenesis, as well as host defense mechanisms and potentially in the association between the sponge and its microorganisms. In addition, these lectins exhibited a broad range of bioactivities, including modulation of inflammatory response, antimicrobial and cytotoxic activities, as well as anticancer and neuromodulatory activity. In view of their potential pharmacological applications, sponge lectins constitute promising molecules of biotechnological interest. PMID:26262628

  14. Porifera Lectins: Diversity, Physiological Roles and Biotechnological Potential.

    PubMed

    Gardčres, Johan; Bourguet-Kondracki, Marie-Lise; Hamer, Bojan; Batel, Renato; Schröder, Heinz C; Müller, Werner E G

    2015-08-01

    An overview on the diversity of 39 lectins from the phylum Porifera is presented, including 38 lectins, which were identified from the class of demosponges, and one lectin from the class of hexactinellida. Their purification from crude extracts was mainly performed by using affinity chromatography and gel filtration techniques. Other protocols were also developed in order to collect and study sponge lectins, including screening of sponge genomes and expression in heterologous bacterial systems. The characterization of the lectins was performed by Edman degradation or mass spectrometry. Regarding their physiological roles, sponge lectins showed to be involved in morphogenesis and cell interaction, biomineralization and spiculogenesis, as well as host defense mechanisms and potentially in the association between the sponge and its microorganisms. In addition, these lectins exhibited a broad range of bioactivities, including modulation of inflammatory response, antimicrobial and cytotoxic activities, as well as anticancer and neuromodulatory activity. In view of their potential pharmacological applications, sponge lectins constitute promising molecules of biotechnological interest. PMID:26262628

  15. Assessment of lectin inactivation by heat and digestion.

    PubMed

    Pusztai, A; Grant, G

    1998-01-01

    Proteins/glycoproteins from plants, particularly lectins, are more resistant to heat denaturation than animal proteins (1, 2). With legume seeds, whose lectin content is appreciable, this presents potentially serious problems in nutritional practice. Therefore, before they can be used safely, legume-based food/ feeds usually require thorough and expensive heat processing to inactivate antinutritive components. Indeed, dry or moist heating of seeds at 70°C for several h has little or no effect on their lectin activity (Fig. 1) and treatment at much higher temperatures is needed to inactivate the biological and antinutritional effects of legume lectins (1, 2). The safety aspect is even more serious with some monocot lectins, such as wheatgerm agglutinin or a number of oilseed lectins, such as peanut agglutinin and many others because they are extremely heat stable and normal cooking or other conventional heat treatments may fail to inactivate them (3) Thus, the best way to avoid potential harmful effects of these heat-resistant lectins is to limit their dietary intake to a minimum. Fig. 1. Loss of lectin activity during aqueous heat treatment of soybean at various temperatures. PMID:21374488

  16. 21 CFR 864.9550 - Lectins and protectins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Products Used In Establishments That Manufacture Blood and Blood Products § 864.9550 Lectins and protectins. (a) Identification. Lectins and protectins are proteins derived from plants and lower animals that cause cell agglutination in the presence of...

  17. 21 CFR 864.9550 - Lectins and protectins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Products Used In Establishments That Manufacture Blood and Blood Products § 864.9550 Lectins and protectins. (a) Identification. Lectins and protectins are proteins derived from plants and lower animals that cause cell agglutination in the presence of...

  18. 21 CFR 864.9550 - Lectins and protectins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Products Used In Establishments That Manufacture Blood and Blood Products § 864.9550 Lectins and protectins. (a) Identification. Lectins and protectins are proteins derived from plants and lower animals that cause cell agglutination in the presence of...

  19. 21 CFR 864.9550 - Lectins and protectins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Products Used In Establishments That Manufacture Blood and Blood Products § 864.9550 Lectins and protectins. (a) Identification. Lectins and protectins are proteins derived from plants and lower animals that cause cell agglutination in the presence of...

  20. 21 CFR 864.9550 - Lectins and protectins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Products Used In Establishments That Manufacture Blood and Blood Products § 864.9550 Lectins and protectins. (a) Identification. Lectins and protectins are proteins derived from plants and lower animals that cause cell agglutination in the presence of...

  1. Complement Activation in Placental Malaria

    PubMed Central

    McDonald, Chloe R.; Tran, Vanessa; Kain, Kevin C.

    2015-01-01

    Sixty percent of all pregnancies worldwide occur in malaria endemic regions. Pregnant women are at greater risk of malaria infection than their non-pregnant counterparts and have a higher risk of adverse birth outcomes including low birth weight resulting from intrauterine growth restriction and/or preterm birth. The complement system plays an essential role in placental and fetal development as well as the host innate immune response to malaria infection. Excessive or dysregulated complement activation has been associated with the pathobiology of severe malaria and with poor pregnancy outcomes, dependent and independent of infection. Here we review the role of complement in malaria and pregnancy and discuss its part in mediating altered placental angiogenesis, malaria-induced adverse birth outcomes, and disruptions to the in utero environment with possible consequences on fetal neurodevelopment. A detailed understanding of the mechanisms underlying adverse birth outcomes, and the impact of maternal malaria infection on fetal neurodevelopment, may lead to biomarkers to identify at-risk pregnancies and novel therapeutic interventions to prevent these complications.

  2. Structure-function relationship of monocot mannose-binding lectins.

    PubMed Central

    Barre, A; Van Damme, E J; Peumans, W J; Rougé, P

    1996-01-01

    The monocot mannose-binding lectins are an extended superfamily of structurally and evolutionarily related proteins, which until now have been isolated from species of the Amaryllidaceae, Alliaceae, Araceae, Orchidaceae, and Liliaceae. To explain the obvious differences in biological activities, the structure-function relationships of the monocot mannose-binding lectins were studied by a combination of glycan-binding studies and molecular modeling using the deduced amino acid sequences of the currently known lectins. Molecular modeling indicated that the number of active mannose-binding sites per monomer varies between three and zero. Since the number of binding sites is fairly well correlated with the binding activity measured by surface plasmon resonance, and is also in good agreement with the results of previous studies of the biological activities of the mannose-binding lectins, molecular modeling is of great value for predicting which lectins are best suited for a particular application. PMID:8972598

  3. The Liverwort Contains a Lectin That Is Structurally and Evolutionary Related to the Monocot Mannose-Binding Lectins1

    PubMed Central

    Peumans, Willy J.; Barre, Annick; Bras, Julien; Rougé, Pierre; Proost, Paul; Van Damme, Els J.M.

    2002-01-01

    A mannose (Man)-binding lectin has been isolated and characterized from the thallus of the liverwort Marchantia polymorpha. N-terminal sequencing indicated that the M. polymorpha agglutinin (Marpola) shares sequence similarity with the superfamily of monocot Man-binding lectins. Searches in the databases yielded expressed sequence tags encoding Marpola. Sequence analysis, molecular modeling, and docking experiments revealed striking structural similarities between Marpola and the monocot Man-binding lectins. Activity and specificity studies further indicated that Marpola is a much stronger agglutinin than the Galanthus nivalis agglutinin and exhibits a preference for methylated Man and glucose, which is unprecedented within the family of monocot Man-binding lectins. The discovery of Marpola allows us, for the first time, to corroborate the evolutionary relationship between a lectin from a lower plant and a well-established lectin family from flowering plants. In addition, the identification of Marpola sheds a new light on the molecular evolution of the superfamily of monocot Man-binding lectins. Beside evolutionary considerations, the occurrence of a G. nivalis agglutinin homolog in a lower plant necessitates the rethinking of the physiological role of the whole family of monocot Man-binding lectins. PMID:12114560

  4. A lactose-binding lectin from the marine sponge Cinachyrella apion (Cal) induces cell death in human cervical adenocarcinoma cells.

    PubMed

    Rabelo, Luciana; Monteiro, Norberto; Serquiz, Raphael; Santos, Paula; Oliveira, Ruth; Oliveira, Adeliana; Rocha, Hugo; Morais, Ana Heloneida; Uchoa, Adriana; Santos, Elizeu

    2012-04-01

    Cancer represents a set of more than 100 diseases, including malignant tumors from different locations. Strategies inducing differentiation have had limited success in the treatment of established cancers. Marine sponges are a biological reservoir of bioactive molecules, especially lectins. Several animal and plant lectins were purified with antitumor activity, mitogenic, anti-inflammatory and antiviral, but there are few reports in the literature describing the mechanism of action of lectins purified from marine sponges to induce apoptosis in human tumor cells. In this work, a lectin purified from the marine sponge Cinachyrella apion (CaL) was evaluated with respect to its hemolytic, cytotoxic and antiproliferative properties, besides the ability to induce cell death in tumor cells. The antiproliferative activity of CaL was tested against HeLa, PC3 and 3T3 cell lines, with highest growth inhibition for HeLa, reducing cell growth at a dose dependent manner (0.5-10 µg/mL). Hemolytic activity and toxicity against peripheral blood cells were tested using the concentration of IC(50) (10 µg/mL) for both trials and twice the IC(50) for analysis in flow cytometry, indicating that CaL is not toxic to these cells. To assess the mechanism of cell death caused by CaL in HeLa cells, we performed flow cytometry and western blotting. Results showed that lectin probably induces cell death by apoptosis activation by pro-apoptotic protein Bax, promoting mitochondrial membrane permeabilization, cell cycle arrest in S phase and acting as both dependent and/or independent of caspases pathway. These results indicate the potential of CaL in studies of medicine for treating cancer. PMID:22690140

  5. Mesenchymal stem cells are injured by complement after their contact with serum

    PubMed Central

    Li, Yan

    2012-01-01

    Despite the potent immunosuppressive activity that mesenchymal stem cells (MSCs) display in vitro, recent clinical trial results are disappointing, suggesting that MSC viability and/or function are greatly reduced after infusion. In this report, we demonstrated that human MSCs activated complement of the innate immunity after their contact with serum. Although all 3 known intrinsic cell-surface complement regulators were present on MSCs, activated complement overwhelmed the protection of these regulators and resulted in MSCs cytotoxicity and dysfunction. In addition, autologous MSCs suffered less cellular injury than allogeneic MSCs after contacting serum. All 3 complement activation pathways were involved in generating the membrane attack complex to directly injure MSCs. Supplementing an exogenous complement inhibitor, or up-regulating MSC expression levels of CD55, one of the cell-surface complement regulators, helped to reduce the serum-induced MSC cytotoxicity. Finally, adoptively transferred MSCs in complement deficient mice or complement-depleted mice showed reduced cellular injury in vivo compared with those in wild type mice. These results indicate that complement is integrally involved in recognizing and injuring MSCs after their infusion, suggesting that autologous MSCs may have ad-vantages over allogeneic MSCs, and that inhibiting complement activation could be a novel strategy to improve existing MSC-based therapies. PMID:22966167

  6. On the Functional Overlap between Complement and Anti-Microbial Peptides

    PubMed Central

    Zimmer, Jana; Hobkirk, James; Mohamed, Fatima; Browning, Michael J.; Stover, Cordula M.

    2015-01-01

    Intriguingly, activated complement and anti-microbial peptides share certain functionalities; lytic, phagocytic, and chemo-attractant activities and each may, in addition, exert cell instructive roles. Each has been shown to have distinct LPS detoxifying activity and may play a role in the development of endotoxin tolerance. In search of the origin of complement, a functional homolog of complement C3 involved in opsonization has been identified in horseshoe crabs. Horseshoe crabs possess anti-microbial peptides able to bind to acyl chains or phosphate groups/saccharides of endotoxin, LPS. Complement activity as a whole is detectable in marine invertebrates. These are also a source of anti-microbial peptides with potential pharmaceutical applicability. Investigating the locality for the production of complement pathway proteins and their role in modulating cellular immune responses are emerging fields. The significance of local synthesis of complement components is becoming clearer from in vivo studies of parenchymatous disease involving specifically generated, complement-deficient mouse lines. Complement C3 is a central component of complement activation. Its provision by cells of the myeloid lineage varies. Their effector functions in turn are increased in the presence of anti-microbial peptides. This may point to a potentiating range of activities, which should serve the maintenance of health but may also cause disease. Because of the therapeutic implications, this review will consider closely studies dealing with complement activation and anti-microbial peptide activity in acute inflammation (e.g., dialysis-related peritonitis, appendicitis, and ischemia). PMID:25646095

  7. Permeability characteristics of complement-damaged membranes: evaluation of the membrane leak generated by the complement proteins C5b-9.

    PubMed Central

    Sims, P J

    1981-01-01

    Permeability characteristics of the membrane lesion generated by the terminal complement proteins are considered in light of recent observations that the measured diffusion of solute across complement-damaged membranes does not conform to the "doughnut hole" model of a discrete transmembrane pore formed by the inserted C5b-9 complex. By using the measured kinetics of steady-state tracer isotope diffusion of nonelectrolytes across resealed erythrocyte ghost membranes treated with C5b-9, a new transport model is developed. This model considers the apparent membrane lesion strictly in terms of the operational criteria of a functional conducting pathway for the observed diffusing solute, independent of a priori assumptions about the geometry or molecular properties of the membrane lesion. With this definition of the unit membrane lesion and the assumption that the exclusion size of the conducting pathway varies directly with the multiplicity of bound C5b-9 (as suggested by previous measurements under conditions of varying input of C5b-9), numerical estimates of te apparent permeability of the complement-damaged membrane to four diffusing nonelectrolytes are derived. These results suggest that the pathway for a particle diffusing across the complement lesion cannot be a pore and is functionally equivalent to an aqueous leak pathway, free of pore constraints. Implications of these results are discussed in terms of current molecular models for the mechanism of membrane damage by the complement proteins. PMID:6940192

  8. ON COMPLEMENTED VERSIONS OF JAMES'S DISTORTION THEOREMS

    E-print Network

    Johnson, William B.

    ON COMPLEMENTED VERSIONS OF JAMES'S DISTORTION THEOREMS WILLIAM B. JOHNSONy AND NARCISSE RANDRIANANTOANINAz Abstract. Examples are given to show that two natural questions asked in * *[5] about complemented versions of James's distortion theorems have

  9. Upregulation of Glycans Containing 3’ Fucose in a Subset of Pancreatic Cancers Uncovered Using Fusion-Tagged Lectins

    PubMed Central

    Singh, Sudhir; Pal, Kuntal; Yadav, Jessica; Tang, Huiyuan; Partyka, Katie; Kletter, Doron; Hsueh, Peter; Ensink, Elliot; Birendra, KC; Hostetter, Galen; Xu, H. Eric; Bern, Marshall; Smith, David F.; Mehta, Anand S.; Brand, Randall; Melcher, Karsten; Haab, Brian B.

    2015-01-01

    The fucose post-translational modification is frequently increased in pancreatic cancer, thus forming the basis for promising biomarkers, but a subset of pancreatic cancer patients does not elevate the known fucose-containing biomarkers. We hypothesized that such patients elevate glycan motifs with fucose in linkages and contexts different from the known fucose-containing biomarkers. We used a database of glycan array data to identify the lectins CCL2 to detect glycan motifs with fucose in a 3’ linkage; CGL2 for motifs with fucose in a 2’ linkage; and RSL for fucose in all linkages. We used several practical methods to test the lectins and determine the optimal mode of detection, and we then tested whether the lectins detected glycans in pancreatic cancer patients who did not elevate the sialyl-Lewis A glycan, which is upregulated in ~75% of pancreatic adenocarcinomas. Patients who did not upregulate sialyl-Lewis A, which contains fucose in a 4’ linkage, tended to upregulate fucose in a 3’ linkage, as detected by CCL2, but they did not upregulate total fucose or fucose in a 2’ linkage. CCL2 binding was high in cancerous epithelia from pancreatic tumors, including areas negative for sialyl-Lewis A and a related motif containing 3’ fucose, sialyl-Lewis X. Thus glycans containing 3’ fucose may complement sialyl-Lewis A to contribute to improved detection of pancreatic cancer. Furthermore, the use of panels of recombinant lectins may uncover details about glycosylation that could be important for characterizing and detecting cancer. PMID:25938165

  10. Complement in the Homeostatic and Ischemic Brain

    PubMed Central

    Alawieh, Ali; Elvington, Andrew; Tomlinson, Stephen

    2015-01-01

    The complement system is a component of the immune system involved in both recognition and response to pathogens, and it is implicated in an increasing number of homeostatic and disease processes. It is well documented that reperfusion of ischemic tissue results in complement activation and an inflammatory response that causes post-reperfusion injury. This occurs following cerebral ischemia and reperfusion and triggers secondary damage that extends beyond the initial infarcted area, an outcome that has rationalized the use of complement inhibitors as candidate therapeutics after stroke. In the central nervous system, however, recent studies have revealed that complement also has essential roles in synaptic pruning, neurogenesis, and neuronal migration. In the context of recovery after stroke, these apparent divergent functions of complement may account for findings that the protective effect of complement inhibition in the acute phase after stroke is not always maintained in the subacute and chronic phases. The development of effective stroke therapies based on modulation of the complement system will require a detailed understanding of complement-dependent processes in both early neurodegenerative events and delayed neuro-reparatory processes. Here, we review the role of complement in normal brain physiology, the events initiating complement activation after cerebral ischemia-reperfusion injury, and the contribution of complement to both injury and recovery. We also discuss how the design of future experiments may better characterize the dual role of complement in recovery after ischemic stroke. PMID:26322048

  11. Cloning and characterization of root-specific barley lectin

    SciTech Connect

    Lerner, D.R.; Raikhel, N.V. )

    1989-09-01

    Cereal lectins are a class of biochemically and antigenically related proteins localized in a tissue-specific manner in embryos and adult plants. To study the specificity of lectin expression, a barley (Hordeum vulgare L.) embryo cDNa library was constructed and a clone (BLc3) for barley lectin was isolated. BLc3 is 972 nucleotides long and includes an open reading frame of 212 amino acids. The deduced amino acid sequence contains a putative signal peptide of 26 amino acid residues followed by a 186 amino acid polypeptide. This polypeptide has 95% sequence identity to the antigenically indistinguishable wheat germ agglutinin isolectin-B (WGA-B) suggesting that BLc3 encodes barley lectin. Further evidence that BLc3 encodes barley lectin was obtained by immunoprecipitation of the in vitro translation products of BLc3 RNA transcripts and barley embryo poly(A{sup +}) RNA. In situ hybridizations with BLc3 showed that barley lectin gene expression is confined to the outermost cell layers of both embryonic and adult root tips. On Northern blots, BLc3 hybridizes to a 1.0 kilobyte mRNA in poly(A{sup +}) RNA from both embryos and root tips. We suggest, on the basis of immunoblot experiments, that barley lectin is synthesized as a glycosylated precursor and processed by removal of a portion of the carboxyl terminus including the single N-linked glycosylation site.

  12. Extensive amino acid sequence homologies between animal lectins

    SciTech Connect

    Paroutaud, P.; Levi, G.; Teichberg, V.I.; Strosberg, A.D.

    1987-09-01

    The authors have established the amino acid sequence of the ..beta..-D-galactoside binding lectin from the electric eel and the sequences of several peptides from a similar lectin isolated from human placenta. These sequences were compared with the published sequences of peptides derived from the ..beta..-D-galactoside binding lectin from human lung and with sequences deduced from cDNAs assigned to the ..beta..-D-galactoside binding lectins from chicken embryo skin and human hepatomas. Significant homologies were observed. One of the highly conserved regions that contains a tryptophan residue and two glutamic acid resides is probably part of the ..beta..-D-galactoside binding site, which, on the basis of spectroscopic studies of the electric eel lectin, is expected to contain such residues. The similarity of the hydropathy profiles and the predicted secondary structure of the lectins from chicken skin and electric eel, in spite of differences in their amino acid sequences, strongly suggests that these proteins have maintained structural homologies during evolution and together with the other ..beta..-D-galactoside binding lectins were derived form a common ancestor gene.

  13. Lectin domains at the frontiers of plant defense

    PubMed Central

    Lannoo, Nausicaä; Van Damme, Els J. M.

    2014-01-01

    Plants are under constant attack from pathogens and herbivorous insects. To protect and defend themselves, plants evolved a multi-layered surveillance system, known as the innate immune system. Plants sense their encounters upon perception of conserved microbial structures and damage-associated patterns using cell-surface and intracellular immune receptors. Plant lectins and proteins with one or more lectin domains represent a major part of these receptors. The whole group of plant lectins comprises an elaborate collection of proteins capable of recognizing and interacting with specific carbohydrate structures, either originating from the invading organisms or from damaged plant cell wall structures. Due to the vast diversity in protein structures, carbohydrate recognition domains and glycan binding specificities, plant lectins constitute a very diverse protein superfamily. In the last decade, new types of nucleocytoplasmic plant lectins have been identified and characterized, in particular lectins expressed inside the nucleus and the cytoplasm of plant cells often as part of a specific plant response upon exposure to different stress factors or changing environmental conditions. In this review, we provide an overview on plant lectin motifs used in the constant battle against pathogens and predators during plant defenses. PMID:25165467

  14. Correlation between proinflammatory role of a lectin from Typhonium giganteum Engl. and macrophage

    PubMed Central

    Pan, Yaozong; Yu, Hongli; Wu, Hao; Chen, Yeqing; Wang, Kuilong; Liu, Liping; Jin, Yangping; Zhang, Chengchao

    2015-01-01

    Purpose: To analyze the correlation between proinflammatory effects of a lectin from Typhonium giganteum Engl. and macrophage. Methods: T. giganteum lectin (TGL) was extracted from the tuber of T. giganteum and purified, and was then identified by using SDS-PAGE gel electrophoresis in combination with mass spectrometry. The morphologic changes of macrophage after being stimulated by TGL were observed with scanning electron microscopy. The influences of such stimulation on neutrophil migration were evaluated by establishing an in vitro macrophage-neutrophil co-culture migration model. By establishing a rat peritoneal macrophage in vitro cultured model, the effects of TGL stimulation on inflammatory factors TNF-? and IL-1? released by macrophage were analyzed. With p65 as the index, the expressions of the NF-?B signaling pathway in the cytoplasm and nucleus were detected before and after TGL stimulation respectively. Furthermore, we also investigated whether the inhibitor for NF-?B signaling pathway BAY11-7082 can block p65 nuclear translocation. Results: After being stimulated by TGL, macrophage had increased volume, number of pseudopodia and gradually cracked cell membrane, accompanied by evidently induced migration of neutrophils due to released inflammatory factors. As the concentration of TGL varied, NF-?B’s monomer p65 had different expression levels in the cytoplasm and nucleus, while BAY11-7082 can indeed block the nuclear translocation of p65. Conclusions: TGL-induced inflammation was closely related to macrophage mediation. PMID:26617695

  15. Complement Factor H Binds to Human Serum Apolipoprotein E and Mediates Complement Regulation on High Density Lipoprotein Particles.

    PubMed

    Haapasalo, Karita; van Kessel, Kok; Nissilä, Eija; Metso, Jari; Johansson, Tiira; Miettinen, Sini; Varjosalo, Markku; Kirveskari, Juha; Kuusela, Pentti; Chroni, Angelika; Jauhiainen, Matti; van Strijp, Jos; Jokiranta, T Sakari

    2015-11-27

    The alternative pathway of complement is an important part of the innate immunity response against foreign particles invading the human body. To avoid damage to host cells, it needs to be efficiently down-regulated by plasma factor H (FH) as exemplified by various diseases caused by mutations in its domains 19-20 (FH19-20) and 5-7 (FH5-7). These regions are also the main interaction sites for microbial pathogens that bind host FH to evade complement attack. We previously showed that inhibition of FH binding by a recombinant FH5-7 construct impairs survival of FH binding pathogens in human blood. In this study we found that upon exposure to full blood, the addition of FH5-7 reduces survival of, surprisingly, also those microbes that are not able to bind FH. This effect was mediated by inhibition of complement regulation and subsequently enhanced neutrophil phagocytosis by FH5-7. We found that although FH5-7 does not reduce complement regulation in the actual fluid phase of plasma, it reduces regulation on HDL particles in plasma. Using affinity chromatography and mass spectrometry we revealed that FH interacts with serum apolipoprotein E (apoE) via FH5-7 domains. Furthermore, binding of FH5-7 to HDL was dependent on the concentration of apoE on the HDL particles. These findings explain why the addition of FH5-7 to plasma leads to excessive complement activation and phagocytosis of microbes in full anticoagulated blood. In conclusion, our data show how FH interacts with apoE molecules via domains 5-7 and regulates alternative pathway activation on plasma HDL particles. PMID:26468283

  16. Lectin, a possible basis for symbiosis between bacteria and sponges.

    PubMed Central

    Müller, W E; Zahn, R K; Kurelec, B; Lucu, C; Müller, I; Uhlenbruck, G

    1981-01-01

    From the marine sponge Halichondria panicea a lectin was isolated and characterized. The homogeneous lectin (composed of protein to 80.7% and of neutral carbohydrates to 14.1%) had a molecular weight of 78,000 (determined by gel filtration) and consisted of four subunits with a molecular weight of 21,000 each (determined by gel electrophoresis in the presence of sodium dodecyl sulfate). The hemagglutinating activity was only slightly dependent upon ionic strength and incubation temperature and did not require divalent cations, but it was inhibited by reagents for thiol groups. The Halichondria lectin was completely inhibited in hemagglutination competition experiments in the presence of fetuin, D-galacturonic acid, D-glucuronic acid, polygalacturonic acid, or L-fucose. The purified Halichondria lectin did not cause reaggregation of dissociated H. panicea cells. From the same sponge species bacteria were isolated and identified as Pseudomonas insolita. These bacteria were cultivated in marine broth 2216. Under these culture conditions the bacteria grew only in the presence of the homologous lectin; the lectin-caused effect was not abolished by D-glucuronic acid or D-galacturonic acid. However, after addition of a polysaccharide-containing fraction isolated from P. insolita, the lectin-caused, growth-promoting effect was abolished. Other lectins were found to exhibit no growth-promoting effect. On the basis of colony counts, P. insolita was the predominant bacterial species in the sponge extract; 1.9 X 10(6) Pseudomonas colonies were measured in extracts isolated from 1 g of sponge. The assumption of an interrelationship between the sponge and the bacterium is supported by the results indicating that the Halichondria lectin has no effect on the growth of such bacteria isolated from six other marine sponge species. Evidence is presented which indicates that the Halichondria lectin is not utilized during growth of the Pseudomonas species. Lectin activity was detected on the surface of mucoid cells from H. panicea. From the data obtained the possibility is discussed that the Halichondria lectin is a basis for a symbiotic relationship between the sponge and the bacterium. Images PMID:7462150

  17. Complementation and Epistasis in Viral Coinfection Dynamics

    PubMed Central

    Gao, Hong; Feldman, Marcus W.

    2009-01-01

    Coinfection in RNA virus populations results in two important phenomena, complementation and recombination. Of the two, complementation has a strong effect on selection against deleterious mutations, as has been confirmed in earlier studies. As complementation delays the purging of less-fit mutations, coinfection may be detrimental to the evolution of a virus population. Here we employ both deterministic modeling and stochastic simulation to explore the mechanisms underlying the interactions between complementation and other evolutionary factors, namely, mutation, selection, and epistasis. We find that strong complementation reduces slightly the overall fitness of a virus population but substantially enhances its diversity and robustness, especially when interacting with selection and epistasis. PMID:19270273

  18. Overview of Complement Activation and Regulation

    PubMed Central

    Noris, Marina; Remuzzi, Giuseppe

    2013-01-01

    Summary Complement is an important component of the innate immune system that is crucial for defense from microbial infections and for clearance of immune complexes and injured cells. In normal conditions complement is tightly controlled by a number of fluid-phase and cell surface proteins to avoid injury to autologous tissues. When complement is hyperactivated, as occurs in autoimmune diseases or in subjects with dysfunctional regulatory proteins, it drives a severe inflammatory response in numerous organs. The kidney appears to be particularly vulnerable to complement-mediated inflammatory injury. Injury may derive from deposition of circulating active complement fragments in glomeruli, but complement locally produced and activated in the kidney also may have a role. Many kidney disorders have been linked to abnormal complement activation, including immune-complex–mediated glomerulonephritis and rare genetic kidney diseases, but also tubulointerstitial injury associated with progressive proteinuric diseases or ischemia-reperfusion. PMID:24161035

  19. The enzymatic lectin of field bean (Dolichos lablab): salt assisted lectin-sugar interaction.

    PubMed

    Rao, Devavratha H; Vishweshwaraiah, Yashavanth L; Gowda, Lalitha R

    2012-11-01

    Field bean seed contains a Gal/GalNAc lectin (DLL-II) that exhibits associated polyphenol oxidase (PPO) activity and does not bind to its sugar specific affinity matrix. The molecular basis for this lack of binding is not known. The DLL-II gene was therefore cloned and its sequence analyzed. A conserved aromatic residue in the sugar binding site required for a stacking interaction with the apolar backbone of Gal is replaced by His in DLL-II, which explains the lack of binding. However, specific sugar binding is achieved by including (NH?)?SO? in the buffer. Interestingly two other salts of the Hofmeister series, K?HPO? and Na?SO? also assist binding to immobilized galactose. In the presence of (NH?)?SO? the surface hydrophobicity of DLL-II and dissociation constant for 8-anilino 1-naphthalene sulfonic acid were enhanced three fold. This increased surface hydrophobicity in the presence of salt is probably the cause for assisted sugar binding in legume lectins that lack aromatic stacking interactions. Accordingly, two other lectins which lack the conserved aromatic residue show similar salt assisted binding. The salt concentrations required for Gal/GalNAc binding are not physiologically relevant in vivo, suggesting that the role of DLL-II per se in the seed is primarily that of a PPO purportedly for plant defense. PMID:22959225

  20. Zinc binding to the Tyr402 and His402 allotypes of complement factor H: possible implications for age-related

    E-print Network

    Martin, Andrew C.R.

    1 Zinc binding to the Tyr402 and His402 allotypes of complement factor H: possible implications of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, UK Running Title: Zinc binding of the alternative pathway of complement activation. High millimolar concentrations of zinc are found in drusen

  1. The (QxW)3 domain: a flexible lectin scaffold.

    PubMed Central

    Hazes, B.

    1996-01-01

    Lectins form a class of proteins that have evolved a specialized carbohydrate-binding function. Based on amino acid sequence analysis, several lectin families have been described and a lectin domain, the (QxW)3 domain, was discussed recently based on 11 family members. In this paper, the (QxW)3 domain family is extended to 45 sequences, several of which have very low sequence identity with the previously known members of the family. A hidden Markov model was used to identify the most divergent members of the family. The expanded set of sequences gives us a more complete appreciation of the conserved features, and the lack thereof, in this lectin family. This, in turn, provides new insights in the structural and functional properties of the individual family members. PMID:8844840

  2. Lectins stain cells differentially in the coral, Montipora capitata

    USGS Publications Warehouse

    Work, Thierry M.; Farah, Yael

    2014-01-01

    A limitation in our understanding of coral disease pathology and cellular pathogenesis is a lack of reagents to characterize coral cells. We evaluated the utility of plant lectins to stain tissues of a dominant coral, Montipora capitata, from Hawaii. Of 22 lectins evaluated, nine of these stained structures in the upper or basal body wall of corals. Specific structures revealed by lectins that were not considered distinct or evident on routine hematoxylin and eosin sections of coral tissues included apical and basal granules in gastrodermis and epidermis, cnidoglandular tract and actinopharynx cell surface membranes, capsules of mature holotrichous isorhizas, and perivitelline and periseminal cells. Plant lectins could prove useful to further our understanding of coral physiology, anatomy, cell biology, and disease pathogenesis.

  3. Molecular cloning of mannose-binding lectins from Clivia miniata.

    PubMed

    Van Damme, E J; Smeets, K; Van Leuven, F; Peumans, W J

    1994-03-01

    Screening of a cDNA library constructed from total RNA isolated from young developing ovaries of Clivia miniata Regel with the amaryllis lectin cDNA clone resulted in the isolation of four different isolectin clones which clearly differ from each other in their nucleotide sequences and hence also in their deduced amino acid sequences. Apparently the lectin is translated from an mRNA of ca. 800 nucleotides encoding a precursor polypeptide of 163 amino acids. Northern blot analysis of total RNA isolated from different tissues of Clivia miniata has shown that the lectin is expressed in most plant tissues with very high lectin mRNA concentrations in the ovary and the seed endosperm. PMID:8193308

  4. Genetics Home Reference: Mannose-binding lectin deficiency

    MedlinePLUS

    ... the normal subunit protein may lead to a reduction of the functional mannose-binding lectin in blood. ... January 4, 2016 Lister Hill National Center for Biomedical Communications U.S. National Library of Medicine , National Institutes ...

  5. 21 CFR 864.9550 - Lectins and protectins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...and protectins. (a) Identification. Lectins and protectins are proteins derived from plants and lower animals that cause cell agglutination in the presence of certain antigens. These substances are used to detect blood group antigens...

  6. 21 CFR 864.9550 - Lectins and protectins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...and protectins. (a) Identification. Lectins and protectins are proteins derived from plants and lower animals that cause cell agglutination in the presence of certain antigens. These substances are used to detect blood group antigens...

  7. 21 CFR 864.9550 - Lectins and protectins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...and protectins. (a) Identification. Lectins and protectins are proteins derived from plants and lower animals that cause cell agglutination in the presence of certain antigens. These substances are used to detect blood group antigens...

  8. Complement Activation and Inhibition in Wound Healing

    PubMed Central

    Cazander, Gwendolyn; Jukema, Gerrolt N.; Nibbering, Peter H.

    2012-01-01

    Complement activation is needed to restore tissue injury; however, inappropriate activation of complement, as seen in chronic wounds can cause cell death and enhance inflammation, thus contributing to further injury and impaired wound healing. Therefore, attenuation of complement activation by specific inhibitors is considered as an innovative wound care strategy. Currently, the effects of several complement inhibitors, for example, the C3 inhibitor compstatin and several C1 and C5 inhibitors, are under investigation in patients with complement-mediated diseases. Although (pre)clinical research into the effects of these complement inhibitors on wound healing is limited, available data indicate that reduction of complement activation can improve wound healing. Moreover, medicine may take advantage of safe and effective agents that are produced by various microorganisms, symbionts, for example, medicinal maggots, and plants to attenuate complement activation. To conclude, for the development of new wound care strategies, (pre)clinical studies into the roles of complement and the effects of application of complement inhibitors in wound healing are required. PMID:23346185

  9. A Lectin from Dioclea violacea Interacts with Midgut Surface of Lutzomyia migonei, Unlike Its Homologues, Cratylia floribunda Lectin and Canavalia gladiata Lectin

    PubMed Central

    Monteiro Tínel, Juliana Montezuma Barbosa; Benevides, Melina Fechine Costa; Frutuoso, Mércia Sindeaux; Rocha, Camila Farias; Arruda, Francisco Vassiliepe Sousa; Vasconcelos, Mayron Alves; Pereira-Junior, Francisco Nascimento; Cajazeiras, Joăo Batista; do Nascimento, Kyria Santiago; Martins, Jorge Luiz; Teixeira, Edson Holanda; Cavada, Benildo Sousa; dos Santos, Ricardo Pires; Lima Pompeu, Margarida Maria

    2014-01-01

    Leishmaniasis is a vector-borne disease transmitted by phlebotomine sand fly. Susceptibility and refractoriness to Leishmania depend on the outcome of multiple interactions that take place within the sand fly gut. Promastigote attachment to sand fly midgut epithelium is essential to avoid being excreted together with the digested blood meal. Promastigote and gut sand fly surface glycans are important ligands in this attachment. The purpose of the present study was to evaluate the interaction of three lectins isolated from leguminous seeds (Diocleinae subtribe), D-glucose and D-mannose-binding, with glycans on Lutzomyia migonei midgut. To study this interaction the lectins were labeled with FITC and a fluorescence assay was performed. The results showed that only Dioclea violacea lectin (DVL) was able to interact with midgut glycans, unlike Cratylia floribunda lectin (CFL) and Canavalia gladiata lectin (CGL). Furthermore, when DVL was blocked with D-mannose the interaction was inhibited. Differences of spatial arrangement of residues and volume of carbohydrate recognition domain (CRD) may be the cause of the fine specificity of DVL for glycans in the surface on Lu. migonei midgut. The findings in this study showed the presence of glycans in the midgut with glucose/mannose residues in its composition and these residues may be important in interaction between Lu. migonei midgut and Leishmania. PMID:25431778

  10. Bacterial Isolation by Lectin-Modified Microengines

    PubMed Central

    Campuzano, Susana; Orozco, Jahir; Kagan, Daniel; Guix, Maria; Gao, Wei; Sattayasamitsathit, Sirilak; Claussen, Jonathan C.; Merkoçi, Arben; Wang, Joseph

    2011-01-01

    New template-based self-propelled gold/nickel/polyaniline/platinum (Au/Ni/PANI/Pt) microtubular engines, functionalized with the Concanavalin A (ConA) lectin bioreceptor, are shown to be extremely useful for the rapid, real-time isolation of Escherichia coli (E. coli) bacteria from fuel-enhanced environmental, food and clinical samples. These multifunctional microtube engines combine the selective capture of E. coli with the uptake of polymeric drug-carrier particles to provide an attractive motion-based theranostics strategy. Triggered release of the captured bacteria is demonstrated by movement through a low-pH glycine-based dissociation solution. The smaller size of the new polymer-metal microengines offers convenient, direct and label-free optical visualization of the captured bacteria and discrimination against non-target cells. PMID:22136558

  11. Complement receptor of the immunoglobulin superfamily reduces murine lupus nephritis and cutaneous disease.

    PubMed

    Lieberman, Linda A; Mizui, Masayuki; Nalbandian, Angčle; Bossé, Robin; Crispín, José C; Tsokos, George C

    2015-10-01

    Complement activation takes place in autoimmune diseases and accounts for tissue inflammation. Previously, complement inhibition has been considered for the treatment of SLE. Complement receptor of the immunoglobulin superfamily (CRIg) is a selective inhibitor of the alternative pathway of complement and a soluble form reverses established inflammation and bone destruction in experimental autoimmune arthritis. We asked whether specific inhibition of the alternative pathway could inhibit autoimmunity and/or organ damage in lupus-prone mice. Accordingly, we treated lupus-prone MRL/lpr mice with a soluble form of CRIg (CRIg-Fc) and we found that it significantly diminished skin lesions, proteinuria and pyuria, and kidney pathology. Interestingly, serum levels of anti-DNA antibodies were not affected despite the fact that serum complement 3 (C3) levels increased significantly. Immunofluorescent staining of kidney tissues revealed a reduction in staining intensity for C3, IgG, and the macrophage marker Mac-2. Thus our data show that inhibition of the alternative pathway of complement controls skin and kidney inflammation even in the absence of an effect on the production of autoantibodies. We propose that CRIg should be considered for clinical trials in patients with systemic lupus erythematosus. PMID:25988858

  12. New Insights of an Old Defense System: Structure, Function, and Clinical Relevance of the Complement System

    PubMed Central

    Ehrnthaller, Christian; Ignatius, Anita; Gebhard, Florian; Huber-Lang, Markus

    2011-01-01

    The complement system was discovered a century ago as a potent defense cascade of innate immunity. After its first description, continuous experimental and clinical research was performed, and three canonical pathways of activation were established. Upon activation by traumatic or surgical tissue damage, complement reveals beneficial functions of pathogen and danger defense by sensing and clearing injured cells. However, the latest research efforts have provided a more distinct insight into the complement system and its clinical subsequences. Complement has been shown to play a significant role in the pathogenesis of various inflammatory processes such as sepsis, multiorgan dysfunction, ischemia/reperfusion, cardiovascular diseases and many others. The three well-known activation pathways of the complement system have been challenged by newer findings that demonstrate direct production of central complement effectors (for example, C5a) by serine proteases of the coagulation cascade. In particular, thrombin is capable of producing C5a, which not only plays a decisive role on pathogens and infected/damaged tissues, but also acts systemically. In the case of uncontrolled complement activation, “friendly fire” is generated, resulting in the destruction of healthy host tissue. Therefore, the traditional research that focuses on a mainly positive-acting cascade has now shifted to the negative effects and how tissue damage originated by the activation of the complement can be contained. In a translational approach including structure-function relations of this ancient defense system, this review provides new insights of complement-mediated clinical relevant diseases and the development of complement modulation strategies and current research aspects. PMID:21046060

  13. N-glycolylneuraminic acid specific lectin from Pila globosa snail.

    PubMed

    Swarnakar, S; Chowdhury, P S; Sarkar, M

    1991-07-15

    A N-glycolylneuraminic acid-specific lectin (PAL) has been purified from an albumin gland extract of the apple snail, Pila globosa. Purification is conducted on a bovine submaxillary mucin-Sepharose 4B affinity matrix followed by gel filtration on a Sepharose 6B column. The lectin agglutinates rabbit erythrocytes. The hemagglutination activity is dependent on Ca2+ concentration in a significant manner but with a remarkable behaviour. The lectin is a trimeric glycoprotein of native Mr 440 kDa with 25% carbohydrate and is composed of three nonidentical subunits of molecular weights 190, 145, and 105 kDa. It has a pI of 7.0. The lectin exhibits a unique and strict specificity toward N-glycolylneuraminic acid and this phenomenon discriminates it from other known sialic acid binding lectins. The uniqueness indicates the absolute need for a glycolyl substitution on the amino residue and of a glyceryl side chain on the exocyclic part and an axial -COOH group in neuraminic acid. The presence of an acetyl substitution on the exocyclic part impedes lectin-ligand interaction. PMID:1906274

  14. Assessment of Sauromatum guttatum lectin toxicity against Bactrocera cucurbitae.

    PubMed

    Kaur, Manpreet; Thakur, Kshema; Kamboj, Sukhdev Singh; Kaur, Satwinder; Kaur, Amritpal; Singh, Jatinder

    2015-11-01

    Lectins are proteins that bind specifically to foreign glycans. Due to this binding property, these molecules have potential application as bioinsecticidal tools replacing conventional chemical insecticides. The present study involved purification of phytolectin from the tubers of Sauromatum guttatum by affinity chromatography on asialofetuin-linked silica matrix. The purity of the sample was checked by SDS-PAGE at pH 8.3. Purified lectin was incorporated in the artificial diet of a Dipteran model, Bactrocera cucurbitae at different concentrations (10, 20, 40, 60 and 80 µgml(-1)). The lectin significantly affected various developmental parameters that were studied. Percentage pupation and percentage emergence was reduced to 44 % and 7.9%, respectively, at 80 µgml(-1) concentration as compared to control (100%). LC50 of Sauromatum guttatum lectin was calculated to be 19.42 µgml(-1). Treatment of insect larvae with LC50 of Sauromatum guttatum lectin suppressed the activity of hydrolytic enzymes (esterases and acid phosphatases) and oxidative enzymes (superoxide dismutase and glutathione-S-transferase). Thus, with low LC50 and high mortality (approximately 92% at 80 µgml(-1)) of the insect larvae, Sauromatum guttatum lectin offers a possibility to engineer crop plants for improved and safer agriculture. PMID:26688959

  15. The Pivotal Role of the Complement System in Aging and Age-related Macular Degeneration: Hypothesis Re-visited

    PubMed Central

    Anderson, Don H.; Radeke, Monte J.; Gallo, Natasha B.; Chapin, Ethan A.; Johnson, Patrick T.; Curletti, Christy R.; Hancox, Lisa S.; Hu, Jane; Ebright, Jessica N.; Malek, Goldis; Hauser, Michael A.; Rickman, Catherine Bowes; Bok, Dean; Hageman, Gregory S.; Johnson, Lincoln V.

    2009-01-01

    During the past ten years, dramatic advances have been made in unraveling the biological bases of age-related macular degeneration (AMD), the most common cause of irreversible blindness in western populations. In that timeframe, two distinct lines of evidence emerged which implicated chronic local inflammation and activation of the complement cascade in AMD pathogenesis. First, a number of complement system proteins, complement activators, and complement regulatory proteins were identified as molecular constituents of drusen, the hallmark extracellular deposits associated with early AMD. Subsequently, genetic studies revealed highly significant statistical associations between AMD and variants of several complement pathway-associated genes including: Complement factor H (CFH), complement factor H-related 1 and 3 (CFHR1 and CFHR3), complement factor B (CFB), complement component 2 (C2), and complement component 3 (C3). In this article, we revisit our original hypothesis that chronic local inflammatory and immune-mediated events at the level of Bruch’s membrane play critical roles in drusen biogenesis and, by extension, in the pathobiology of AMD. Secondly, we report the results of a new screening for additional AMD-associated polymorphisms in a battery of 63 complement-related genes. Third, we identify and characterize the local complement system in the RPE-choroid complex -- thus adding a new dimension of biological complexity to the role of the complement system in ocular aging and AMD. Finally, we evaluate the most salient, recent evidence that bears directly on the role of complement in AMD pathogenesis and progression. Collectively, these recent findings strongly re-affirm the importance of the complement system in AMD. They lay the groundwork for further studies that may lead to the identification of a transcriptional disease signature of AMD, and hasten the development of new therapeutic approaches that will restore the complement-modulating activity that appears to be compromised in genetically susceptible individuals. PMID:19961953

  16. Purification and cDNA cloning of a lectin and a lectin-like protein from Apios americana Medikus tubers.

    PubMed

    Kouzuma, Yoshiaki; Irie, Satoshi; Yamazaki, Rikiya; Yonekura, Masami

    2014-01-01

    An Apios americana lectin (AAL) and a lectin-like protein (AALP) were purified from tubers by chromatography on Butyl-Cellulofine, ovomucoid-Cellulofine, and DEAE-Cellulofine columns. AAL showed strong hemagglutinating activity toward chicken and goose erythrocytes, but AALP showed no such activity toward any of the erythrocytes tested. The hemagglutinating activity of AAL was not inhibited by mono- or disaccharides, but was inhibited by glycoproteins, such as asialofetuin and ovomucoid, suggesting that AAL is an oligosaccharide-specific lectin. The cDNAs of AAL and AALP consist of 1,093 and 1,104 nucleotides and encode proteins of 302 and 274 amino acid residues, respectively. Both amino acid sequences showed high similarity to known legume lectins, and those of their amino acids involved in carbohydrate and metal binding were conserved. PMID:25036952

  17. Role of Complement in Autoimmune Hemolytic Anemia

    PubMed Central

    Berentsen, Sigbjřrn

    2015-01-01

    Summary The classification of autoimmune hemolytic anemias and the complement system are reviewed. In autoimmune hemolytic anemia of the warm antibody type, complement-mediated cell lysis is clinically relevant in a proportion of the patients but is hardly essential for hemolysis in most patients. Cold antibody-mediated autoimmune hemolytic anemias (primary cold agglutinin disease, secondary cold agglutinin syndrome and paroxysmal cold hemoglobinuria) are entirely complement-mediated disorders. In cold agglutinin disease, efficient therapies have been developed in order to target the pathogenic B-cell clone, but complement modulation remains promising in some clinical situations. No established therapy exists for secondary cold agglutinin syndrome and paroxysmal cold hemoglobinuria, and the possibility of therapeutic complement inhibition is interesting. Currently, complement modulation is not clinically documented in any autoimmune hemolytic anemia. The most relevant candidate drugs and possible target levels of action are discussed. PMID:26696798

  18. The major tuber storage protein of araceae species is a lectin. Characterization and molecular cloning of the lectin from Arum maculatum L.

    PubMed Central

    Van Damme, E J; Goossens, K; Smeets, K; Van Leuven, F; Verhaert, P; Peumans, W J

    1995-01-01

    A new lectin was purified from tubers of Arum maculatum L. by affinity chromatography on immobilized asialofetuin. Although this lectin is also retained on mannose-Sepharose 4B, under the appropriate conditions free mannose is a poor inhibitor of its agglutination activity. Pure preparations of the Arum lectin apparently yielded a single polypeptide band of approximately 12 kD upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis. However, N-terminal sequencing of the purified protein combined with molecular cloning of the lectin have shown that the lectin is composed of two different 12-kD lectin subunits that are synthesized on a single large precursor translated from an mRNA of approximately 1400 nucleotides. Lectins with similar properties were also isolated from the Araceae species Colocasia esculenta (L.) Schott, Xanthosoma sagittifolium (L.) Schott, and Dieffenbachia sequina Schott. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration of the different Araceae lectins have shown that they are tetrameric proteins composed of lectin subunits of 12 to 14 kD. Interestingly, these lectins are the most prominent proteins in the tuber tissue. Evidence is presented that a previously described major storage protein of Colocasia tubers corresponds to the lectin. PMID:7770523

  19. 21 CFR 866.4100 - Complement reagent.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents § 866.4100 Complement reagent. (a)...

  20. 21 CFR 866.4100 - Complement reagent.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents § 866.4100 Complement reagent. (a)...

  1. Differential activity of candidate microbicides against early steps of HIV-1 infection upon complement virus opsonization

    PubMed Central

    2010-01-01

    Background HIV-1 in genital secretions may be opsonized by several molecules including complement components. Opsonized HIV-1 by complement enhances the infection of various mucosal target cells, such as dendritic cells (DC) and epithelial cells. Results We herein evaluated the effect of HIV-1 complement opsonization on microbicide candidates' activity, by using three in vitro mucosal models: CCR5-tropic HIV-1JR-CSF transcytosis through epithelial cells, HIV-1JR-CSF attachment on immature monocyte-derived dendritic cells (iMDDC), and infectivity of iMDDC by CCR5-tropic HIV-1BaL and CXCR4-tropic HIV-1NDK. A panel of 10 microbicide candidates [T20, CADA, lectines HHA & GNA, PVAS, human lactoferrin, and monoclonal antibodies IgG1B12, 12G5, 2G12 and 2F5], were investigated using cell-free unopsonized or opsonized HIV-1 by complements. Only HHA and PVAS were able to inhibit HIV trancytosis. Upon opsonization, transcytosis was affected only by HHA, HIV-1 adsorption on iMDDC by four molecules (lactoferrin, IgG1B12, IgG2G5, IgG2G12), and replication in iMDDC of HIV-1BaL by five molecules (lactoferrin, CADA, T20, IgG1B12, IgG2F5) and of HIV-1NDK by two molecules (lactoferrin, IgG12G5). Conclusion These observations demonstrate that HIV-1 opsonization by complements may modulate in vitro the efficiency of candidate microbicides to inhibit HIV-1 infection of mucosal target cells, as well as its crossing through mucosa. PMID:20546571

  2. Differential pathways regulating innate and adaptive antitumor immune responses by particulate and soluble yeast-derived ?-glucans.

    PubMed

    Qi, Chunjian; Cai, Yihua; Gunn, Lacey; Ding, Chuanlin; Li, Bing; Kloecker, Goetz; Qian, Keqing; Vasilakos, John; Saijo, Shinobu; Iwakura, Yoichiro; Yannelli, John R; Yan, Jun

    2011-06-23

    ?-glucans have been reported to function as a potent adjuvant to stimulate innate and adaptive immune responses. However, ?-glucans from different sources are differential in their structure, conformation, and thus biologic activity. Different preparations of ?-glucans, soluble versus particulate, further complicate their mechanism of action. Here we show that yeast-derived particulate ?-glucan activated dendritic cells (DCs) and macrophages via a C-type lectin receptor dectin-1 pathway. Activated DCs by particulate ?-glucan promoted Th1 and cytotoxic T-lymphocyte priming and differentiation in vitro. Treatment of orally administered yeast-derived particulate ?-glucan elicited potent antitumor immune responses and drastically down-regulated immunosuppressive cells, leading to the delayed tumor progression. Deficiency of the dectin-1 receptor completely abrogated particulate ?-glucan-mediated antitumor effects. In contrast, yeast-derived soluble ?-glucan bound to DCs and macrophages independent of the dectin-1 receptor and did not activate DCs. Soluble ?-glucan alone had no therapeutic effect but significantly augmented antitumor monoclonal antibody-mediated therapeutic efficacy via a complement activation pathway but independent of dectin-1 receptor. These findings reveal the importance of different preparations of ?-glucans in the adjuvant therapy and allow for the rational design of immunotherapeutic protocols usable in clinical trials. PMID:21531981

  3. Opsonization of Streptococcus agalactiae of bovine origin by complement and antibodies against group B polysaccharide.

    PubMed Central

    Rainard, P; Boulard, C

    1992-01-01

    The contribution of bovine complement and antibodies (Ab) against the group B polysaccharidic antigen (GBA) to the opsonization of Streptococcus agalactiae isolated from bovine mastitis cases was investigated by using affinity-purified Ab. GBA-specific Ab were not opsonic by themselves, but in the presence of complement (precolostral calf serum) with an opsonization time of 15 min, they exhibited a dose-dependent opsonic activity in a polymorphonuclear leukocyte chemiluminescence assay. Kinetic studies of the deposition of complement component C3 on protein X-bearing nontypeable (NT/X) strains with an enzyme-linked immunosorbent assay showed that C3 was deposited on bacteria in the absence of Ab but that GBA-specific Ab markedly accelerated the process by reducing the lag phase, which extended up to 15 min when Ab were absent. In the absence of Ab, C3 deposition was inhibited by 5 mM salicylaldoxime or heat treatment at 56 degrees C for 3 min and necessitated Mg2+ ions but not Ca2+ ions, suggesting that activation of complement was effected by the alternative pathway only. When GBA-specific Ab were added to complement, the inhibitory treatments lost much of their efficacy, suggesting that the classical pathway was recruited. Deposition of C3 on NT/X strains in the absence of Ab induced chemiluminescence and phagocytic killing. With the addition of GBA-specific Ab, the numbers of surviving bacteria were halved (P < 0.05) compared with killing in the presence of complement alone. It can be concluded that NT/X strains are activators of the alternative pathway of complement and that GBA-specific Ab reinforce the opsonic efficiency of serum by recruiting the classical pathway and slightly enhancing phagocytic killing. PMID:1398991

  4. Lectin-like molecules in transcriptome of Littorina littorea hemocytes.

    PubMed

    Gorbushin, Alexander M; Borisova, Elena A

    2015-01-01

    The common periwinkle Littorina littorea was introduced in the list of models for comparative immunobiology as a representative of phylogenetically important taxon Caenogastropoda. Using Illumina sequencing technology, we de novo assembled the transcriptome of Littorina littorea hemocytes from 182 million mRNA-Seq pair-end 100?bp reads into a total of 15,526 contigs clustered in 4472 unigenes. The transcriptome profile was analyzed for presence of carbohydrate-binding molecules in a variety of architectural contexts. Hemocytes' repertoire of lectin-like proteins bearing conserved carbohydrate-recognition domains (CRDs) is highly diversified, including 11 of 15 lectin families earlier described in animals, as well as the novel members of lectin family found for the first time in mollusc species. The new molluscan lineage-specific domain combinations were confirmed by cloning and sequencing, including the fuco-lectin related molecules (FLReMs) composed of N-terminal region with no sequence homology to any known protein, a middle Fucolectin Tachylectin-4 Pentaxrin (FTP) domain, and a C-terminal epidermal growth factor (EGF) repeat region. The repertoire of lectin-like molecules is discussed in terms of their potential participation in the receptor phase of immune response. In total, immune-associated functions may be attributed to 70 transcripts belonging to 6 lectin families. These lectin-like genes show low overlap between species of invertebrates, suggesting relatively rapid evolution of immune-associated genes in the group. The repertoire provides valuable candidates for further characterization of the gene functions in mollusc immunity. PMID:25451301

  5. Commitment and Evidence in Arabic Complementation.

    ERIC Educational Resources Information Center

    Awad, Maher

    The study examines one component of the system of complementation in Palestinian Arabic. It is argued that the complementizer in question has an inherent semantics capable of influencing the meaning of sentences in which it is embedded. Specifically, its presence in a complex sentence communicates modal meanings distinct from those communicated by…

  6. Progress and Trends in Complement Therapeutics

    PubMed Central

    Ricklin, Daniel; Lambris, John D.

    2012-01-01

    The past few years have proven to be a highly successful and exciting period for the field of complement-directed drug discovery and development. Driven by promising experiences with the first marketed complement drugs, increased knowledge about the involvement of complement in health and disease, and improvements in structural and analytical techniques as well as animal models of disease, the field has seen a surge in creative approaches to therapeutically intervene at various stages of the cascade. An impressive panel of compounds that show promise in clinical trials is meanwhile being lined up in the pipelines of both small biotechnology and big pharmaceutical companies. Yet with this new focus on complement-targeted therapeutics, important questions concerning target selection, point and length of intervention, safety, and drug delivery emerge. In view of the diversity of the clinical disorders involving abnormal complement activity or regulation, which include both acute and chronic diseases and affect a wide range of organs, diverse yet specifically tailored therapeutic approaches may be needed to shift complement back into balance. This chapter highlights the key changes in the field that shape our current perception of complement-targeted drugs and provides a brief overview of recent strategies and emerging trends. Selected examples of complement-related diseases and inhibitor classes are highlighted to illustrate the diversity and creativity in field. PMID:22990692

  7. Dissecting complement blockade for clinic use.

    PubMed

    Risitano, Antonio M

    2015-01-29

    In this issue of Blood, Peffault de Latour et al describe ex vivo measurements of complement activity in paroxysmal nocturnal hemoglobinuria (PNH) patients on eculizumab treatment. This is the first systematic pharmacodynamic (PD) study of eculizumab in PNH patients which shows that CH50 is a promising biomarker of therapeutic complement blockade. PMID:25634611

  8. HiTrap Affinity columns HiTrap Wheat Germ Lectin, 1 ml INSTRUCTIONS

    E-print Network

    Lebendiker, Mario

    HiTrap Affinity columns HiTrap Wheat Germ Lectin, 1 ml INSTRUCTIONS HiTrapTM Wheat Germ Lectin , GradiFracTM or FPLCTM . Table 1. Content of HiTrap Wheat Germ Lectin Code No. Designation No. supplied 17-5107-01 HiTrap Wheat Germ Lectin 5x1 ml Connectors Luerlock female/M6 male 1 Luerlock female/M6

  9. Involvement of ER stress in apoptosis induced by sialic acid-binding lectin (leczyme) from bullfrog eggs.

    PubMed

    Tatsuta, Takeo; Hosono, Masahiro; Miura, Yuki; Sugawara, Shigeki; Kariya, Yukiko; Hakomori, Senitiroh; Nitta, Kazuo

    2013-12-01

    Sialic-acid binding lectin (SBL) isolated from bullfrog (Rana catesbeiana) oocytes is a multifunctional protein which has lectin activity, ribonuclease activity and cancer-selective antitumor activity. It has been reported that SBL induces apoptosis accompanied by rigid mitochondrial perturbation, which indicates mediation of the intrinsic pathway. However, the mechanism of the antitumor effect of SBL has not been fully elucidated. We report, here, that ER stress is evoked in SBL-treated cells. We show that caspase-4, an initiator caspase of ER stress-mediated apoptosis was activated, and inhibition of caspase-4 resulted in significant attenuation of apoptosis induced by SBL. We analyzed the precise mechanism of activation of the caspase cascade induced by SBL, and found that caspase-9 and -4 are activated upstream of activation of caspase-8. Further study revealed that SBL induces the mitochondrial and ER stress-mediated pathways independently. It is noteworthy that SBL can induce cancer-selective apoptosis by multiple apoptotic signaling pathways, and it can serve as a candidate molecule for anticancer drugs in a novel field. PMID:24100413

  10. Differential mechanisms of complement-mediated neutralization of the closely related paramyxoviruses simian virus 5 and mumps virus

    SciTech Connect

    Johnson, John B.; Capraro, Gerald A.; Parks, Griffith D.

    2008-06-20

    The complement system is an important component of the innate immune response to virus infection. The role of human complement pathways in the in vitro neutralization of three closely related paramyxoviruses, Simian Virus 5 (SV5), Mumps virus (MuV) and Human Parainfluenza virus type 2 (HPIV2) was investigated. Sera from ten donors showed high levels of neutralization against HPIV2 that was largely complement-independent, whereas nine of ten donor sera were found to neutralize SV5 and MuV only in the presence of active complement pathways. SV5 and MuV neutralization proceeded through the alternative pathway of the complement cascade. Electron microscopy studies and biochemical analyses showed that treatment of purified SV5 with human serum resulted in C3 deposition on virions and the formation of massive aggregates, but there was relatively little evidence of virion lysis. Treatment of MuV with human serum also resulted in C3 deposition on virions, however in contrast to SV5, MuV particles were lysed by serum complement and there was relatively little aggregation. Assays using serum depleted of complement factors showed that SV5 and MuV neutralization in vitro was absolutely dependent on complement factor C3, but was not dependent on downstream complement factors C5 or C8. Our results indicate that even though antibodies exist that recognize both SV5 and MuV, they are mostly non-neutralizing and viral inactivation in vitro occurs through the alternative pathway of complement. The implications of our work for development of paramyxovirus vectors and vaccines are discussed.

  11. Complement System Part II: Role in Immunity

    PubMed Central

    Merle, Nicolas S.; Noe, Remi; Halbwachs-Mecarelli, Lise; Fremeaux-Bacchi, Veronique; Roumenina, Lubka T.

    2015-01-01

    The complement system has been considered for a long time as a simple lytic cascade, aimed to kill bacteria infecting the host organism. Nowadays, this vision has changed and it is well accepted that complement is a complex innate immune surveillance system, playing a key role in host homeostasis, inflammation, and in the defense against pathogens. This review discusses recent advances in the understanding of the role of complement in physiology and pathology. It starts with a description of complement contribution to the normal physiology (homeostasis) of a healthy organism, including the silent clearance of apoptotic cells and maintenance of cell survival. In pathology, complement can be a friend or a foe. It acts as a friend in the defense against pathogens, by inducing opsonization and a direct killing by C5b–9 membrane attack complex and by triggering inflammatory responses with the anaphylatoxins C3a and C5a. Opsonization plays also a major role in the mounting of an adaptive immune response, involving antigen presenting cells, T-, and B-lymphocytes. Nevertheless, it can be also an enemy, when pathogens hijack complement regulators to protect themselves from the immune system. Inadequate complement activation becomes a disease cause, as in atypical hemolytic uremic syndrome, C3 glomerulopathies, and systemic lupus erythematosus. Age-related macular degeneration and cancer will be described as examples showing that complement contributes to a large variety of conditions, far exceeding the classical examples of diseases associated with complement deficiencies. Finally, we discuss complement as a therapeutic target. PMID:26074922

  12. Emerging and Novel Functions of Complement Protein C1q

    PubMed Central

    Kouser, Lubna; Madhukaran, Shanmuga Priyaa; Shastri, Abhishek; Saraon, Anuvinder; Ferluga, Janez; Al-Mozaini, Maha; Kishore, Uday

    2015-01-01

    Complement protein C1q, the recognition molecule of the classical pathway, performs a diverse range of complement and non-complement functions. It can bind various ligands derived from self, non-self, and altered self and modulate the functions of immune and non-immune cells including dendritic cells and microglia. C1q involvement in the clearance of apoptotic cells and subsequent B cell tolerance is more established now. Recent evidence appears to suggest that C1q plays an important role in pregnancy where its deficiency and dysregulation can have adverse effects, leading to preeclampsia, missed abortion, miscarriage or spontaneous loss, and various infections. C1q is also produced locally in the central nervous system, and has a protective role against pathogens and possible inflammatory functions while interacting with aggregated proteins leading to neurodegenerative diseases. C1q role in synaptic pruning, and thus CNS development, its anti-cancer effects as an immune surveillance molecule, and possibly in aging are currently areas of extensive research. PMID:26175731

  13. Emerging and Novel Functions of Complement Protein C1q.

    PubMed

    Kouser, Lubna; Madhukaran, Shanmuga Priyaa; Shastri, Abhishek; Saraon, Anuvinder; Ferluga, Janez; Al-Mozaini, Maha; Kishore, Uday

    2015-01-01

    Complement protein C1q, the recognition molecule of the classical pathway, performs a diverse range of complement and non-complement functions. It can bind various ligands derived from self, non-self, and altered self and modulate the functions of immune and non-immune cells including dendritic cells and microglia. C1q involvement in the clearance of apoptotic cells and subsequent B cell tolerance is more established now. Recent evidence appears to suggest that C1q plays an important role in pregnancy where its deficiency and dysregulation can have adverse effects, leading to preeclampsia, missed abortion, miscarriage or spontaneous loss, and various infections. C1q is also produced locally in the central nervous system, and has a protective role against pathogens and possible inflammatory functions while interacting with aggregated proteins leading to neurodegenerative diseases. C1q role in synaptic pruning, and thus CNS development, its anti-cancer effects as an immune surveillance molecule, and possibly in aging are currently areas of extensive research. PMID:26175731

  14. Crystal Structure of Arcelin-5, a Lectin-like Defense Protein from Phaseolus vulgaris*

    E-print Network

    Hamelryck, Thomas

    Crystal Structure of Arcelin-5, a Lectin-like Defense Protein from Phaseolus vulgaris* (Received of the legume plants, a class of sugar- binding proteins with high structural and sequential identity is found two such lectins, a lectin-like defense pro- tein called arcelin, in which one sugar binding loop

  15. Community-Based Network Study of Protein-Carbohydrate Interactions in Plant Lectins Using Glycan

    E-print Network

    Lee, Jooyoung

    Community-Based Network Study of Protein- Carbohydrate Interactions in Plant Lectins Using Glycan lectins and their interacting carbohydrates by using community-based analysis of a lectin-carbohydrate functional groups. Citation: Malik A, Lee J, Lee J (2014) Community-Based Network Study of Protein-Carbohydrate

  16. Histological and lectin histochemical studies on the olfactory and respiratory mucosae of the sheep.

    PubMed

    Ibrahim, Dalia; Nakamuta, Nobuaki; Taniguchi, Kazumi; Yamamoto, Yoshio; Taniguchi, Kazuyuki

    2014-03-01

    The olfactory and respiratory mucosae of the Corriedale sheep were examined using lectin histochemistry in order to clarify the histochemical and glycohistochemical differences between these two tissues. The olfactory epithelium was stained with 13 lectins out of 21 lectins examined, while the respiratory epithelium was positive to 16 lectins. The free border of both of the olfactory and respiratory epithelia was stained with 12 lectins: Wheat germ agglutinin (WGA), succinylated-wheat germ agglutinin (s-WGA), Lycopersicon esculentum lectin (LEL), Solanum tuberosum lectin (STL), Datura stramonium lectin (DSL), Soybean agglutinin (SBA), Bandeiraea simplicifolia lectin-I (BSL-I), Ricinus communis agglutinin-I (RCA-120), Erythrina cristagalli lectin (ECL), Concanavalin A (Con A), Phaseolus vulgaris agglutinin-E (PHA-E) and Phaseolus vulgaris agglutinin-L (PHA-L). The associated glands of the olfactory mucosa, Bowman's glands, were stained with 13 lectins. While both the goblet cells and mucous nasal glands were stained with 8 lectins; five of them (WGA, s-WGA, STL, Vicia villosa agglutinin (VVA) and ECL) were mutually positive among the Bowman's glands, mucous nasal glands and the goblet cells. These findings indicate that the glycohistochemical characteristics of the free borders of both olfactory and respiratory epithelia are similar to each other, suggesting that secretions from the Bowman's glands and those of the goblet cells and mucous nasal glands are partially exchanged between the surface of two epithelia to contribute the functions of the respiratory epithelium and the olfactory receptor cells, respectively. PMID:24200894

  17. Prevalence of the F-type lectin domain.

    PubMed

    Bishnoi, Ritika; Khatri, Indu; Subramanian, Srikrishna; Ramya, T N C

    2015-08-01

    F-type lectins are fucolectins with characteristic fucose and calcium-binding sequence motifs and a unique lectin fold (the "F-type" fold). F-type lectins are phylogenetically widespread with selective distribution. Several eukaryotic F-type lectins have been biochemically and structurally characterized, and the F-type lectin domain (FLD) has also been studied in the bacterial proteins, Streptococcus mitis lectinolysin and Streptococcus pneumoniae SP2159. However, there is little knowledge about the extent of occurrence of FLDs and their domain organization, especially, in bacteria. We have now mined the extensive genomic sequence information available in the public databases with sensitive sequence search techniques in order to exhaustively survey prokaryotic and eukaryotic FLDs. We report 437 FLD sequence clusters (clustered at 80% sequence identity) from eukaryotic, eubacterial and viral proteins. Domain architectures are diverse but mostly conserved in closely related organisms, and domain organizations of bacterial FLD-containing proteins are very different from their eukaryotic counterparts, suggesting unique specialization of FLDs to suit different requirements. Several atypical phylogenetic associations hint at lateral transfer. Among eukaryotes, we observe an expansion of FLDs in terms of occurrence and domain organization diversity in the taxa Mollusca, Hemichordata and Branchiostomi, perhaps coinciding with greater emphasis on innate immune strategies in these organisms. The naturally occurring FLDs with diverse domain organizations that we have identified here will be useful for future studies aimed at creating designer molecular platforms for directing desired biological activities to fucosylated glycoconjugates in target niches. PMID:25943580

  18. A biologically active lectin of enteroaggregative Escherichia coli.

    PubMed

    Basu, Sulagna; Ghosh, Sujata; Ganguly, N K; Majumdar, S

    2004-01-01

    The pathogenesis of enteroaggregative Escherichia coli, a major contributor to paediatric diarrhoea, is still not clearly understood. A complex carbohydrate specific lectin was identified from the culture supernatant of an enteroaggregative E. coli strain. The lectin was purified to 660-fold by a combination of sequential saturated ammonium sulphate precipitation and gel filtration chromatography in the FPLC system. The homogeneity of the purified lectin was established by analytical isoelectrofocusing [pI 6.75]. Hemagglutination of rabbit erythrocytes by the purified lectin was best inhibited by fetuin. The N-terminal sequence of the 41.7 kDa subunit showed homology to the outermembrane porins and the 23.4 kDa subunit showed homology to a hypothetical protein of Yersinia pestis and secreted Hcp protein. This protein could induce extensive morphological changes in HEp-2 cells and significant amount of fluid accumulation in rabbit ileal loop. GM1 showed maximum binding to the lectin among all other gangliosides. This purified protein showed cross-reactivity to the binding subunit of cholera toxin in western immunoblot. The presence of this toxin in some of the clinical isolates of enteroaggregative E. coli was also observed. The structural and functional characteristics of the toxin revealed that it is a novel virulence determinant of aggregative E. coli. PMID:15556276

  19. Lectin Activity in Gut Extract of Culex pipiens

    PubMed Central

    Koosha, Mona; Abai, Mohammad Reza; Abolhasani, Mandan; Charedar, Soroor; Basseri, Hamid Reza

    2013-01-01

    Background: The role of lectins is important in interaction between pathogens and mosquito vectors. This study was performed to identify agglutinin activities of protein molecules on the midgut of Culex pipiens. Methods: Culex pipiens was reared in insectray condition and the midguts of males and females (blood fed and unfed) were dissected separately in Tris-HCl buffer. The extracts of midguts were applied for hemagglutinin assay against red blood cells of rabbit, mouse, rat, dog, horse, sheep, guinea pig, cow, human (A, B, AB, O groups). Then, the RBCs with relatively high agglutinin activity were chosen for carbohydrate inhibition assay. D (+) glucose, D (+) galactose, D (+) mannose, D (?) fructose, D (?) arabinose, L (?) fucose, lactose, N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, sialic acid were used to specify carbohydrate binding lectin. Results: The highest agglutinin activities were found against sheep and rabbits RBCs. Sexual diversity of agglutinin activities was observed among midgut extraction of males and females. In addition, variation in agglutinin activity of blood fed and unfed female mosquitoes were detected. The lectin activity was inhibited highly with glucose, galactose, fucose and fructose but less inhibitor activities was observed by arabinose, N-acetyl-D-galactosamine, n-acetyl-d-glucosamine, lactose and mannose. Conclusion: The secretion of hemagglutinins (lectins or lectin-like molecules) in the digestive system depends on the type of food in the gut. This suggests that emptying of the gut in preparation for protein rich food probably starts the secretion of hemagglutinins. PMID:23785692

  20. Evolution of the complement system in protostomes revealed by de novo transcriptome analysis of six species of Arthropoda.

    PubMed

    Sekiguchi, Reo; Nonaka, Masaru

    2015-05-01

    To elucidate the evolutionary history of the complement system in Arthropoda, de novo transcriptome analysis was performed with six species among the Chelicerata, Myriapoda, and Crustacea, and complement genes were identified based on their characteristic domain structures. Complement C3 and factor B (FB) were identified from a sea spider, a jumping spider, and a centipede, but not from a sea firefly or two millipede species. No additional complement components identifiable by their characteristic domain structures were found from any of these six species. These results together with genome sequence information for several species of the Hexapoda suggest that the common ancestor of the Arthropoda possessed a simple complement system comprising C3 and FB, and thus resembled the alternative pathway of the mammalian complement system. It was lost at least twice independently during the evolution of Arthropoda in the millipede lineage and in the common ancestor of Crustacea and Hexapoda. PMID:25530095

  1. Mannan-Binding Lectin in Cardiovascular Disease

    PubMed Central

    Cedzy?ski, Maciej

    2014-01-01

    Cardiovascular disease remains the leading cause of mortality and morbidity worldwide so research continues into underlying mechanisms. Since innate immunity and its potent component mannan-binding lectin have been proven to play an important role in the inflammatory response during infection and ischaemia-reperfusion injury, attention has been paid to its role in the development of cardiovascular complications as well. This review provides a general outline of the structure and genetic polymorphism of MBL and its role in inflammation/tissue injury with emphasis on associations with cardiovascular disease. MBL appears to be involved in the pathogenesis of atherosclerosis and, in consequence, coronary artery disease and also inflammation and tissue injury after myocardial infarction and heart transplantation. The relationship between MBL and disease is rather complex and depends on different genetic and environmental factors. That could be why the data obtained from animal and clinical studies are sometimes contradictory proving not for the first time that innate immunity is a “double-edge sword,” sometimes beneficial and, at other times disastrous for the host. PMID:24877121

  2. Electrochemical potential of Microgramma vaccinifolia rhizome lectin.

    PubMed

    Santana, Giselly Maria de Sá; Albuquerque, Lidiane Pereira de; Napoleăo, Thiago Henrique; Souza, Sandra Rodrigues de; Coelho, Luana Cassandra Breitenbach Barroso; Paiva, Patrícia Maria Guedes

    2012-06-01

    This work reports the isolation of Microgramma vaccinifolia rhizome lectin (MvRL) and the determination of electrochemical potentials of MvRL in the presence of Ca˛?, Mg˛? and human type O erythrocytes. MvRL showed the highest specific hemagglutinating activity with human type O erythrocytes and showed a single polypeptide band of 17 kDa on SDS-PAGE. MvRL hemagglutinating activity was neutralized after dialysis with EDTA, and addition of Ca˛? and Mg˛? restored the activity. Electrochemical potentials of MvRL in the presence of 100 mM Ca˛? (882 mV) and 60 mM Mg˛? (1051 mV) were higher (p<0.05) than in the presence of only 0.15 M NaCl (247 mV), indicating that the electrochemical system was sensitive to structural and physico-chemical changes promoted by these ions. MvRL potential did not change in the presence of type O erythrocytes. The electrochemical system was able to detect changes in electrochemical potentials of MvRL promoted by Ca˛? and Mg˛?, even in a complex environment (human serum supplemented with 40 and 60mM of these ions). The study reveals that the stimulatory effect of Ca˛? and Mg˛? on hemagglutinating activity may be linked to conformational change and/or alterations in surface charge distribution of MvRL. PMID:22197266

  3. The role of complement in C3 glomerulopathy.

    PubMed

    Zipfel, Peter F; Skerka, Christine; Chen, Qian; Wiech, Thorsten; Goodship, Tim; Johnson, Sally; Fremeaux-Bacchi, Veronique; Nester, Clara; de Córdoba, Santiago Rodríguez; Noris, Marina; Pickering, Matthew; Smith, Richard

    2015-09-01

    C3 glomerulopathy describes a spectrum of disorders with glomerular pathology associated with C3 cleavage product deposition and with defective complement action and regulation (Fakhouri et al., 2010; Sethi et al., 2012b). Kidney biopsies from these patients show glomerular accumulation or deposition of C3 cleavage fragments, but no or minor deposition of immunoglobulins (Appel et al., 2005; D'Agati and Bomback, 2012; Servais et al., 2007; Sethi and Fervenza, 2011). At present the current situation asks for a better definition of the underlining disease mechanisms, for precise biomarkers, and for a treatment for this disease. The complement system is a self activating and propelling enzymatic cascade type system in which inactive, soluble plasma components are activated spontaneously and lead into an amplification loop (Zipfel and Skerka, 2009). Activation of the alternative pathway is spontaneous, occurs by default, and cascade progression leads to amplification by complement activators. The system however is self-controlled by multiple regulators and inhibitors, like Factor H that control cascade progression in fluid phase and on surfaces. The activated complement system generates a series of potent effector components and activation products, which damage foreign-, as well as modified self cells, recruit innate immune cells to the site of action, coordinate inflammation and the response of the adaptive immune system in form of B cells and T lymphocytes (Kohl, 2006; Medzhitov and Janeway, 2002; Ogden and Elkon, 2006; Carroll, 2004; Kemper and Atkinson, 2007; Morgan, 1999; Muller-Eberhard, 1986; Ricklin et al., 2010). Complement controls homeostasis and multiple reactions in the vertebrate organism including defense against microbial infections (Diaz-Guillen et al., 1999; Mastellos and Lambris, 2002; Nordahl et al., 2004; Ricklin et al., 2010). In consequence defective control of the spontaneous self amplifying cascade or regulation is associated with numerous human disorders (Ricklin and Lambris, 2007; Skerka and Zipfel, 2008; Zipfel et al., 2006). Understanding the exact action and regulation of this sophisticated homeotic cascade system is relevant to understand disease pathology of various complement associated human disorders. Furthermore this knowledge is relevant for a better diagnosis and appropriate therapy. At present diagnosis of C3 glomerulopathy is primarily based on the kidney biopsy, and histological, immmunohistological and electron microscopical evaluation (D'Agati and Bomback, 2012; Fakhouri et al., 2010; Medjeral-Thomas et al., 2014a,b; Sethi et al., 2012b). The challenge is to define the actual cause of the diverse glomerular changes or damages, to define how C3 deposition results in the reported glomerular changes, the location of the cell damage and the formation of deposits. PMID:25929733

  4. Homologous Canavalia lectins elicit different patterns of antinociceptive responses.

    PubMed

    Pinto, Nilson Vieira; Santos, Cláudia Ferreira; Cavada, Benildo Sousa; do Nascimento, Kyria Santiago; Pereira Junior, Francisco Nascimento; Pires, Alana de Freitas; Assreuy, Ana Maria Sampaio

    2013-11-01

    Canavalia gladiata (CGL), C. maritima (ConM) and C. brasiliensis (ConBr) lectins were evaluated in nociception models. ConBr inhibited first (32%) and second (100%) phases of the formalin test; CGL inhibited only the first (74%) and ConM only the second (59%) phase. Hypernociception evaluated in the Von Frey test was inhibited by ConM (55%), CGL (41%) and ConBr (38%). Acetic acid-induced abdominal writhing was reduced by ConBr (66%), CGL (52%) and ConM (60%). ConBr and CGL effects were reversed by the lectin association with its ligand sugar. The antinociceptive activity of the structural homologous lectins was differentiated by potency, efficacy and mechanisms. PMID:24427956

  5. Lectin activity of the nucleocytoplasmic EUL protein from Arabidopsis thaliana

    PubMed Central

    Van Hove, Jonas; Fouquaert, Elke; Smith, David F.; Proost, Paul; Van Damme, Els J.M.

    2011-01-01

    The Euonymus lectin (EUL) domain was recognized as the structural motif for a novel class of putative carbohydrate binding proteins. Confocal microscopy demonstrated that the lectin from Euonymus europaeus (EEA) as well as the EUL protein from Arabidopsis thaliana (ArathEULS3) are located in the nucleocytoplasmic compartment of the plant cell. ArathEULS3 as well as its EUL domain were successfully expressed in Pichia pastoris and purified. The EUL domain from Arabidopsis interacts with glycan structures containing Lewis Y, Lewis X and lactosamine, indicating that it can be considered a true lectin domain. Despite the high sequence identity between the EUL domains in EEA and ArathEULS3, both domains recognize different carbohydrate structures. PMID:21945438

  6. Transorganellar complementation redefines the biochemical continuity of endoplasmic reticulum and chloroplasts

    PubMed Central

    Mehrshahi, Payam; Stefano, Giovanni; Andaloro, Joshua Michael; Brandizzi, Federica; Froehlich, John E.; DellaPenna, Dean

    2013-01-01

    Tocopherols are nonpolar compounds synthesized and localized in plastids but whose genetic elimination specifically impacts fatty acid desaturation in the endoplasmic reticulum (ER), suggesting a direct interaction with ER-resident enzymes. To functionally probe for such interactions, we developed transorganellar complementation, where mutated pathway activities in one organelle are experimentally tested for substrate accessibility and complementation by active enzymes retargeted to a companion organelle. Mutations disrupting three plastid-resident activities in tocopherol and carotenoid synthesis were complemented from the ER in this fashion, demonstrating transorganellar access to at least seven nonpolar, plastid envelope-localized substrates from the lumen of the ER, likely through plastid:ER membrane interaction domains. The ability of enzymes in either organelle to access shared, nonpolar plastid metabolite pools redefines our understanding of the biochemical continuity of the ER and chloroplast with profound implications for the integration and regulation of organelle-spanning pathways that synthesize nonpolar metabolites in plants. PMID:23818635

  7. Role of complement in host-microbe homeostasis of the periodontium

    PubMed Central

    Hajishengallis, George; Abe, Toshiharu; Maekawa, Tomoki; Hajishengallis, Evlambia; Lambris, John D.

    2013-01-01

    Complement plays a key role in immunity and inflammation through direct effects on immune cells or via crosstalk and regulation of other host signaling pathways. Deregulation of these finely balanced complement activities can link infection to inflammatory tissue damage. Periodontitis is a polymicrobial community-induced chronic inflammatory disease that can destroy the tooth-supporting tissues. In this review, we summarize and discuss evidence that complement is involved in the dysbiotic transformation of the periodontal microbiota and in the inflammatory process that leads to the destruction of periodontal bone. Recent insights into the mechanisms of complement involvement in periodontitis have additionally provided likely targets for therapeutic intervention against this oral disease. PMID:23684627

  8. Inhibition of aberrant complement activation by a dimer of acetylsalicylic acid.

    PubMed

    Lee, Moonhee; Wathier, Matthew; Love, Jennifer A; McGeer, Edith; McGeer, Patrick L

    2015-10-01

    We here report synthesis for the first time of the acetyl salicylic acid dimer 5,5'-methylenebis(2-acetoxybenzoic acid) (DAS). DAS inhibits aberrant complement activation by selectively blocking factor D of the alternative complement pathway and C9 of the membrane attack complex. We have previously identified aurin tricarboxylic and its oligomers as promising agents in this regard. DAS is much more potent, inhibiting erythrocyte hemolysis by complement-activated serum with an IC50 in the 100-170 nanomolar range. There are numerous conditions where self-damage from the complement system has been implicated in the pathology, including such chronic degenerative diseases of aging as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and age-related macular degeneration. Consequently, there is a high priority for the discovery and development of agents that can successfully treat such conditions. DAS holds considerable promise for being such an agent. PMID:26248865

  9. CD46: the 'multitasker' of complement proteins.

    PubMed

    Yamamoto, Hidekazu; Fara, Antonella Francesca; Dasgupta, Prokar; Kemper, Claudia

    2013-12-01

    Complement is undeniably quintessential for innate immunity by detecting and eliminating infectious microorganisms. Recent work, however, highlights an equally profound impact of complement on the induction and regulation of a wide range of immune cells. In particular, the complement regulator CD46 emerges as a key sensor of immune activation and a vital modulator of adaptive immunity. In this review, we summarize the current knowledge of CD46-mediated signalling events and their functional consequences on immune-competent cells with a specific focus on those in CD4(+) T cells. We will also discuss the promises and challenges that potential therapeutic modulation of CD46 may hold and pose. PMID:24120647

  10. Eculizumab reduces complement activation, inflammation, endothelial damage, thrombosis, and renal injury markers in aHUS.

    PubMed

    Cofiell, Roxanne; Kukreja, Anjli; Bedard, Krystin; Yan, Yan; Mickle, Angela P; Ogawa, Masayo; Bedrosian, Camille L; Faas, Susan J

    2015-05-21

    Atypical hemolytic uremic syndrome (aHUS) is a genetic, life-threatening disease characterized by uncontrolled complement activation, systemic thrombotic microangiopathy (TMA), and vital organ damage. We evaluated the effect of terminal complement blockade with the anti-C5 monoclonal antibody eculizumab on biomarkers of cellular processes involved in TMA in patients with aHUS longitudinally, during up to 1 year of treatment, compared with in healthy volunteers. Biomarker levels were elevated at baseline in most patients, regardless of mutational status, plasma exchange/infusion use, platelet count, or lactate dehydrogenase or haptoglobin levels. Eculizumab reduced terminal complement activation (C5a and sC5b-9) and renal injury markers (clusterin, cystatin-C, ?2-microglobulin, and liver fatty acid binding protein-1) to healthy volunteer levels and reduced inflammation (soluble tumor necrosis factor receptor-1), coagulation (prothrombin fragment F1+2 and d-dimer), and endothelial damage (thrombomodulin) markers to near-normal levels. Alternative pathway activation (Ba) and endothelial activation markers (soluble vascular cell adhesion molecule-1) decreased but remained elevated, reflecting ongoing complement activation in aHUS despite complete terminal complement blockade. These results highlight links between terminal complement activation and inflammation, endothelial damage, thrombosis, and renal injury and underscore ongoing risk for systemic TMA and progression to organ damage. Further research regarding underlying complement dysregulation is warranted. This trial was registered at www.clinicaltrials.gov as #NCT01194973. PMID:25833956

  11. Eculizumab reduces complement activation, inflammation, endothelial damage, thrombosis, and renal injury markers in aHUS

    PubMed Central

    Cofiell, Roxanne; Kukreja, Anjli; Bedard, Krystin; Yan, Yan; Mickle, Angela P.; Ogawa, Masayo; Bedrosian, Camille L.

    2015-01-01

    Atypical hemolytic uremic syndrome (aHUS) is a genetic, life-threatening disease characterized by uncontrolled complement activation, systemic thrombotic microangiopathy (TMA), and vital organ damage. We evaluated the effect of terminal complement blockade with the anti-C5 monoclonal antibody eculizumab on biomarkers of cellular processes involved in TMA in patients with aHUS longitudinally, during up to 1 year of treatment, compared with in healthy volunteers. Biomarker levels were elevated at baseline in most patients, regardless of mutational status, plasma exchange/infusion use, platelet count, or lactate dehydrogenase or haptoglobin levels. Eculizumab reduced terminal complement activation (C5a and sC5b-9) and renal injury markers (clusterin, cystatin-C, ?2-microglobulin, and liver fatty acid binding protein-1) to healthy volunteer levels and reduced inflammation (soluble tumor necrosis factor receptor-1), coagulation (prothrombin fragment F1+2 and d-dimer), and endothelial damage (thrombomodulin) markers to near-normal levels. Alternative pathway activation (Ba) and endothelial activation markers (soluble vascular cell adhesion molecule-1) decreased but remained elevated, reflecting ongoing complement activation in aHUS despite complete terminal complement blockade. These results highlight links between terminal complement activation and inflammation, endothelial damage, thrombosis, and renal injury and underscore ongoing risk for systemic TMA and progression to organ damage. Further research regarding underlying complement dysregulation is warranted. This trial was registered at www.clinicaltrials.gov as #NCT01194973. PMID:25833956

  12. Treatment with human complement factor H rapidly reverses renal complement deposition in factor H-deficient mice

    PubMed Central

    Fakhouri, F.; de Jorge, E. Goicoechea; Brune, F.; Azam, P.; Cook, H.T.; Pickering, M.C.

    2010-01-01

    Total deficiency of complement factor H (CFH) is associated with dense deposit disease (DDD) and atypical haemolytic uraemic syndrome (aHUS). CFH is the major regulator of the alternative pathway of complement activation and its complete deficiency results in uncontrolled C3 activation through this pathway and secondary C3 deficiency. Plasma infusion, as a source of CFH, has been used with variable success to treat renal disease associated with CFH deficiency. However, the risks of volume and protein overload limit this therapeutic approach. In this study, we investigated the efficacy of a purified human CFH (hCFH) preparation in Cfh-gene knockout mice. These mice spontaneously develop both secondary plasma C3 deficiency and renal abnormality characterised by massive deposition of C3 along the glomerular basement membrane. The renal lesion is analogous to human dense deposit disease. Treatment of knockout mice with hCFH resulted in rapid normalization of plasma C3 levels and resolution of the glomerular basement membrane C3 deposition. Long-term assessment of mice with hCFH was not possible because of the development of an immune response against hCFH. Hence, we suggest that hCFH can be an effective alternative therapy to plasma infusions in patients with renal disease associated with CFH deficiency. PMID:20445496

  13. Treatment with human complement factor H rapidly reverses renal complement deposition in factor H-deficient mice.

    PubMed

    Fakhouri, Fadi; de Jorge, Elena Goicoechea; Brune, Frédérique; Azam, Philippe; Cook, H Terence; Pickering, Matthew C

    2010-08-01

    Total deficiency of complement factor H (CFH) is associated with dense deposit disease and atypical hemolytic uremic syndrome. CFH is the major regulator of the alternative pathway of complement activation and its complete deficiency results in uncontrolled C3 activation through this pathway and secondary C3 deficiency. Plasma infusion, as a source of CFH, has been used with variable success to treat renal disease associated with its deficiency. However, the risks of volume and protein overload limit this therapeutic approach. In this study, we investigated the efficacy of a purified human CFH (hCFH) preparation in Cfh-gene knockout mice. These mice spontaneously develop both secondary plasma C3 deficiency and a renal abnormality characterized by massive accumulation of C3 along the glomerular basement membrane. The renal lesion is analogous to human dense deposit disease. Treatment of knockout mice with hCFH resulted in rapid normalization of plasma C3 levels and resolution of the glomerular basement membrane C3 deposition. Long-term treatment of mice with hCFH was not possible because of the development of an immune response against hCFH. Hence, we suggest that hCFH can be an effective alternative therapy to plasma infusions in patients with renal disease associated with CFH deficiency. PMID:20445496

  14. Altered expression of sialylated glycoproteins in ovarian cancer sera using lectin-based ELISA assay and quantitative glycoproteomics analysis.

    PubMed

    Wu, Jing; Xie, Xiaolei; Nie, Song; Buckanovich, Ronald J; Lubman, David M

    2013-07-01

    Herein, we identify and confirm differentially expressed sialoglycoproteins in the serum of patients with ovarian cancer. On the basis of Sambucus nigra (SNA) lectin enrichment and on an isobaric chemical labeling quantitative strategy, clusterin (CLUS), leucine-rich alpha-2-glycoprotein (LRG1), hemopexin (HEMO), vitamin D-binding protein (VDB), and complement factor H (CFH) were found to be differentially expressed in the serum of patients with ovarian cancer compared to benign diseases. The abnormal sialylation levels of CLUS, CFH, and HEMO in serum of ovarian cancer patients were verified by a lectin-based ELISA assay. ELISA assays were further applied to measure total protein level changes of these glycoproteins. Protein levels of CLUS were found to be down-regulated in the serum of ovarian cancer patients, while protein levels of LRG1 were increased. The combination of CLUS and LRG1 (AUC = 0.837) showed improved performance for distinguishing stage III ovarian cancer from benign diseases compared to CA125 alone (AUC = 0.811). In differentiating early stage ovarian cancer from benign diseases or healthy controls, LRG1 showed comparable performance to CA125. An independent sample set was further used to confirm the ability of these candidate markers to detect patients with ovarian cancer. Our study provides a comprehensive strategy for the identification of candidate biomarkers that show the potential for diagnosis of ovarian cancer. Further studies using a large number of samples are necessary to validate the utility of this panel of proteins. PMID:23731285

  15. Anopheles Midgut Epithelium Evades Human Complement Activity by Capturing Factor H from the Blood Meal

    PubMed Central

    Khattab, Ayman; Barroso, Marta; Miettinen, Tiera; Meri, Seppo

    2015-01-01

    Hematophagous vectors strictly require ingesting blood from their hosts to complete their life cycles. Exposure of the alimentary canal of these vectors to the host immune effectors necessitates efficient counteractive measures by hematophagous vectors. The Anopheles mosquito transmitting the malaria parasite is an example of hematophagous vectors that within seconds can ingest human blood double its weight. The innate immune defense mechanisms, like the complement system, in the human blood should thereby immediately react against foreign cells in the mosquito midgut. A prerequisite for complement activation is that the target cells lack complement regulators on their surfaces. In this work, we analyzed whether human complement is active in the mosquito midgut, and how the mosquito midgut cells protect themselves against complement attack. We found that complement remained active for a considerable time and was able to kill microbes within the mosquito midgut. However, the Anopheles mosquito midgut cells were not injured. These cells were found to protect themselves by capturing factor H, the main soluble inhibitor of the alternative complement pathway. Factor H inhibited complement on the midgut cells by promoting inactivation of C3b to iC3b and preventing the activity of the alternative pathway amplification C3 convertase enzyme. An interference of the FH regulatory activity by monoclonal antibodies, carried to the midgut via blood, resulted in increased mosquito mortality and reduced fecundity. By using a ligand blotting assay, a putative mosquito midgut FH receptor could be detected. Thereby, we have identified a novel mechanism whereby mosquitoes can tolerate human blood. PMID:25679788

  16. Soluble Host Defense Lectins in Innate Immunity to Influenza Virus

    PubMed Central

    Ng, Wy Ching; Tate, Michelle D.; Brooks, Andrew G.; Reading, Patrick C.

    2012-01-01

    Host defenses against viral infections depend on a complex interplay of innate (nonspecific) and adaptive (specific) components. In the early stages of infection, innate mechanisms represent the main line of host defense, acting to limit the spread of virus in host tissues prior to the induction of the adaptive immune response. Serum and lung fluids contain a range of lectins capable of recognizing and destroying influenza A viruses (IAV). Herein, we review the mechanisms by which soluble endogenous lectins mediate anti-IAV activity, including their role in modulating IAV-induced inflammation and disease and their potential as prophylactic and/or therapeutic treatments during severe IAV-induced disease. PMID:22665991

  17. Structure, interactions and evolutionary implications of a domain-swapped lectin dimer from Mycobacterium smegmatis.

    PubMed

    Patra, Dhabaleswar; Mishra, Padmanabh; Surolia, Avadhesha; Vijayan, Mamannamana

    2014-10-01

    Crystal structure determination of the lectin domain of MSMEG_3662 from Mycobacterium smegmatis and its complexes with mannose and methyl-?-mannose, the first effort of its kind on a mycobacterial lectin, reveals a structure very similar to ?-prism II fold lectins from plant sources, but with extensive unprecedented domain swapping in dimer formation. The two subunits in a dimer often show small differences in structure, but the two domains, not always related by 2-fold symmetry, have the same structure. Each domain carries three sugar-binding sites, similar to those in plant lectins, one on each Greek key motif. The occurrence of ?-prism II fold lectins in bacteria, with characteristics similar to those from plants, indicates that this family of lectins is of ancient origin and had evolved into a mature system before bacteria and plants diverged. In plants, the number of binding sites per domain varies between one and three, whereas the number is two in the recently reported lectin domains from Pseudomonas putida and Pseudomonas aeruginosa. An analysis of the sequences of the lectins and the lectin domains shows that the level of sequence similarity among the three Greek keys in each domain has a correlation with the number of binding sites in it. Furthermore, sequence conservation among the lectins from different species is the highest for that Greek key which carries a binding site in all of them. Thus, it would appear that carbohydrate binding influences the course of the evolution of the lectin. PMID:24957055

  18. Lectin-binding sites in epithelial cells of the mouse prostate gland.

    PubMed

    Sakuda, Kentaro; Yoshida, Ayaka; Muragishi, Ryoki; Yoshinaga, Kazuya

    2014-01-01

    The prostate is an exocrine gland in the male reproductive tract that secretes seminal fluids. To gain insight into the cytochemical properties of prostatic epithelial cells, the characteristics of glycoconjugates in mouse prostate sections were examined by lectin histochemistry and immunohistochemistry. Characteristic staining patterns were observed, depending on the type of lectins present in the epithelia. Luminal cells reacted specifically with mannose-binding lectins (Galanthus nivalis lectin, Hippeastrum hybrid lectin, Narcissus pseudonarcissus lectin) and Maclura pomifera lectin in all lobes of the prostate. Luminal cells also expressed galactose, N-acetyl-D-galactosamine (GalNAc), N-acetyl-D-glucosamine (GlcNAc), and fucose residues in the lateral and ventral lobes. Basal cells expressed GlcNAc and fucose, and reacted with Datura stramonium lectin and Aleuria aurantia lectin in all lobes. These results indicate that in the mouse prostate, the selectivity of lectin-binding sites for distinct cell types and lobe-dependent staining may relate to cellular and regional differences in function. Furthermore, some lectins selectively bound to prostatic epithelial cells, indicating their potential use as markers for the histopathological evaluation of prostatic diseases, cancer diagnosis, or male infertility. PMID:26004072

  19. Structures and binding specificity of galactose- and mannose-binding lectins from champedak: differences from jackfruit lectins.

    PubMed

    Gabrielsen, Mads; Abdul-Rahman, Puteri Shafinaz; Othman, Shatrah; Hashim, Onn H; Cogdell, Richard J

    2014-06-01

    Galactose-binding and mannose-binding lectins from the champedak fruit, which is native to South-east Asia, exhibit useful potential clinical applications. The specificity of the two lectins for their respective ligands allows the detection of potential cancer biomarkers and monitoring of the glycosylated state of proteins in human serum and/or urine. To fully understand and expand the use of these natural proteins, their complete sequences and crystal structures are presented here, together with details of sugar binding. PMID:24915077

  20. Effect of gamma irradiation on mistletoe (Viscum album) lectin-mediated toxicity and immunomodulatory activity.

    PubMed

    Sung, Nak-Yun; Byun, Eui-Baek; Song, Du-Sup; Jin, Yeung-Bae; Kim, Jae-Kyung; Park, Jong-Heum; Song, Beom-Seok; Jung, Pil-Mun; Byun, Myung-Woo; Lee, Ju-Woon; Park, Sang-Hyun; Kim, Jae-Hun

    2013-01-01

    This study evaluated the effect of gamma irradiation on the reduction of the toxicity of mistletoe lectin using both in vitro and in vivo models. To extract the lectin from mistletoe, an (NH4)2SO4 precipitation method was employed and the precipitant purified using a Sepharose 4B column to obtain the pure lectin fraction. Purified lectin was then gamma-irradiated at doses of 0, 5, 10, 15, and 20 kGy, or heated at 100 °C for 30 min. Toxic effects of non-irradiated, irradiated, and heat-treated lectins were tested using hemagglutination assays, cytotoxicity assays, hepatotoxicity, and a mouse survival test and immunological response was tested using cytokine production activity. Hemagglutination of lectin was remarkably decreased (P < 0.05) by irradiation at doses exceeding 10 kGy and with heat treatment. However, lectin irradiated with 5 kGy maintained its hemagglutination activity. The cytotoxicity of lectin was decreased by irradiation at doses over 5 kGy and with heat treatment. In experiments using mouse model, glutamate oxaloacetate transaminase (GOT) and glutamic pyruvic transaminase (GPT) levels were decreased in the group treated with the 5 kGy irradiated and heat-treated lectins as compared to the intact lectin, and it was also shown that 5 kGy irradiated and heat-treated lectins did not cause damage in liver tissue or mortality. In the result of immunological response, tumor necrosis factor (TNF-?) and interleukin (IL-6) levels were significantly (P < 0.05) increased in the 5 kGy gamma-irradiated lectin treated group. These results indicate that 5 kGy irradiated lectin still maintained the immunological response with reduction of toxicity. Therefore, gamma-irradiation may be an effective method for reducing the toxicity of lectin maintaining the immune response. PMID:23847758

  1. Effect of gamma irradiation on mistletoe (Viscum album) lectin-mediated toxicity and immunomodulatory activity?

    PubMed Central

    Sung, Nak-Yun; Byun, Eui-Baek; Song, Du-Sup; Jin, Yeung-Bae; Kim, Jae-Kyung; Park, Jong-Heum; Song, Beom-Seok; Jung, Pil-Mun; Byun, Myung-Woo; Lee, Ju-Woon; Park, Sang-Hyun; Kim, Jae-Hun

    2013-01-01

    This study evaluated the effect of gamma irradiation on the reduction of the toxicity of mistletoe lectin using both in vitro and in vivo models. To extract the lectin from mistletoe, an (NH4)2SO4 precipitation method was employed and the precipitant purified using a Sepharose 4B column to obtain the pure lectin fraction. Purified lectin was then gamma-irradiated at doses of 0, 5, 10, 15, and 20 kGy, or heated at 100 °C for 30 min. Toxic effects of non-irradiated, irradiated, and heat-treated lectins were tested using hemagglutination assays, cytotoxicity assays, hepatotoxicity, and a mouse survival test and immunological response was tested using cytokine production activity. Hemagglutination of lectin was remarkably decreased (P < 0.05) by irradiation at doses exceeding 10 kGy and with heat treatment. However, lectin irradiated with 5 kGy maintained its hemagglutination activity. The cytotoxicity of lectin was decreased by irradiation at doses over 5 kGy and with heat treatment. In experiments using mouse model, glutamate oxaloacetate transaminase (GOT) and glutamic pyruvic transaminase (GPT) levels were decreased in the group treated with the 5 kGy irradiated and heat-treated lectins as compared to the intact lectin, and it was also shown that 5 kGy irradiated and heat-treated lectins did not cause damage in liver tissue or mortality. In the result of immunological response, tumor necrosis factor (TNF-?) and interleukin (IL-6) levels were significantly (P < 0.05) increased in the 5 kGy gamma-irradiated lectin treated group. These results indicate that 5 kGy irradiated lectin still maintained the immunological response with reduction of toxicity. Therefore, gamma-irradiation may be an effective method for reducing the toxicity of lectin maintaining the immune response. PMID:23847758

  2. Dimerization of complement factor H-related proteins modulates complement activation in vivo

    PubMed Central

    Goicoechea de Jorge, Elena; Caesar, Joseph J. E.; Malik, Talat H.; Patel, Mitali; Colledge, Matthew; Johnson, Steven; Hakobyan, Svetlana; Morgan, B. Paul; Harris, Claire L.; Pickering, Matthew C.; Lea, Susan M.

    2013-01-01

    The complement system is a key component regulation influences susceptibility to age-related macular degeneration, meningitis, and kidney disease. Variation includes genomic rearrangements within the complement factor H-related (CFHR) locus. Elucidating the mechanism underlying these associations has been hindered by the lack of understanding of the biological role of CFHR proteins. Here we present unique structural data demonstrating that three of the CFHR proteins contain a shared dimerization motif and that this hitherto unrecognized structural property enables formation of both homodimers and heterodimers. Dimerization confers avidity for tissue-bound complement fragments and enables these proteins to efficiently compete with the physiological complement inhibitor, complement factor H (CFH), for ligand binding. Our data demonstrate that these CFHR proteins function as competitive antagonists of CFH to modulate complement activation in vivo and explain why variation in the CFHRs predisposes to disease. PMID:23487775

  3. Phagocytosis of leprosy bacilli is mediated by complement receptors CR1 and CR3 on human monocytes and complement component C3 in serum.

    PubMed Central

    Schlesinger, L S; Horwitz, M A

    1990-01-01

    Mycobacterium leprae, an obligate intracellular pathogen, invades and multiplies within host mononuclear phagocytes. To understand M. leprae invasion better, we have investigated the role of phagocyte receptors and bacterium-bound ligands in phagocytosis of M. leprae by human monocytes. Complement receptors CR1 and CR3 mediate adherence and phagocytosis of M. leprae in nonimmune serum. Two MAbs used in combination against CR3 inhibit adherence by up to 90 +/- 3%. Two MAbs used in combination against CR1 and CR3 inhibit adherence by up to 70 +/- 1%. Single MAbs against CR1 or CR3 consistently inhibit adherence by 38-55%. In contrast, MAbs against other monocyte surface molecules, alone or in combination, do not significantly influence adherence. As studied by electron microscopy, 100% of monocyte-associated M. leprae are ingested in the presence of nonimmune serum and MAbs against CR3 markedly inhibit ingestion. Complement receptors CR1 and CR3 also mediate the low level of adherence observed in the absence of serum. Serum complement component C3 serves as a ligand on the bacterial surface in monocyte phagocytosis of M. leprae. Adherence of M. leprae to monocytes is enhanced by preopsonization (3.1 +/- 1.1-fold increase) and is markedly reduced in less than 0.5% fresh serum (66 +/- 7% reduction) or heat-inactivated serum (68 +/- 3% reduction). Adherence is also markedly reduced in C3- or factor B-depleted serum; repletion with purified C3 or factor B increases adherence 4.3 +/- 0.8- and 2.6 +/- 0.2-fold, respectively. C3 is fixed to M. leprae by the alternative pathway of complement activation, as determined by a whole bacterial cell ELISA. By electron microscopy, monocytes ingest M. leprae by conventional phagocytosis. This study demonstrates that (a) human monocyte complement receptors CR1 and CR3 mediate phagocytosis of M. leprae; (b) complement component C3 on the bacterial surface serves as a ligand for complement receptors; (c) complement component C3 binds to M. leprae by the alternative pathway of complement activation; and (d) monocytes phagocytize M. leprae by conventional phagocytosis. Images PMID:2138634

  4. Complementing Logic Program Semantics Roberto Giacobazzi ? Francesco Ranzato ??

    E-print Network

    Giacobazzi, Roberto

    Complementing Logic Program Semantics Roberto Giacobazzi ? Francesco Ranzato ?? ? Dipartimento di and complementation of abstract domains, as a tool to systematically derive denotational semantics by composition and decomposition. Reduced product allows to perform the logical conjunction of semantics, while complementation

  5. Coagulation and complement system in critically ill patients.

    PubMed

    Helling, H; Stephan, B; Pindur, G

    2015-09-01

    Activation of coagulation and inflammatory response including the complement system play a major role in the pathogenesis of critical illness. However, only limited data are available addressing the relationship of both pathways and its assessment of a predictive value for the clinical outcome in intense care medicine. Therefore, parameters of the coagulation and complement system were studied in patients with septicaemia and multiple trauma regarded as being exemplary for critical illness. 34 patients (mean age: 51.38 years (±16.57), 15 females, 19 males) were investigated at day 1 of admittance to the intensive care unit (ICU). Leukocytes, complement factors C3a and C5a were significantly (p?< ?0.0500) higher in sepsis than in trauma, whereas platelet count and plasma fibrinogen were significantly lower in multiple trauma. Activation markers of coagulation were elevated in both groups, however, thrombin-antithrombin-complex was significantly higher in multiple trauma. DIC scores of 5 were not exceeded in any of the two groups. Analysing the influences on mortality (11/34; 32.35% ), which was not different in both groups, non-survivors were significantly older, had significantly higher multiple organ failure (MOF) scores, lactate, abnormal prothrombin times and lower C1-inhibitor activities, even more pronounced in early deaths, than survivors. In septic non-survivors protein C was significantly lower than in trauma. We conclude from these data that activation of the complement system as part of the inflammatory response is a significant mechanism in septicaemia, whereas loss and consumption of blood components including parts of the coagulation and complement system is more characteristic for multiple trauma. Protein C in case of severe reduction might be of special concern for surviving in sepsis. Activation of haemostasis was occurring in both diseases, however, overt DIC was not confirmed in this study to be a leading mechanism in critically ill patients. MOF score, lactate, C1-inhibitor and prothrombin time have been the only statistically significant predictors for lethal outcome suggesting that organ function, microcirculation, haemostasis and inflammatory response are essential elements of the pathomechanism and clinical course of diseases among critically ill patients. PMID:26410872

  6. Mannan-binding lectin of the sea urchin Strongylocentrotus nudus.

    PubMed

    Bulgakov, Aleksandr A; Eliseikina, Marina G; Kovalchuk, Svetlana N; Petrova, Irina Yu; Likhatskaya, Galina N; Shamshurina, Ekaterina V; Rasskazov, Valery A

    2013-02-01

    A novel lectin specific to low-branched mannans (MBL-SN) was isolated from coelomic plasma of the sea urchin Strongylocentrotus nudus by combining anion-exchange liquid chromatography on DEAE Toyopearl 650 M, affinity chromatography on mannan-Sepharose and gel filtration on the Sephacryl S-200. The molecular mass of MBL-SN was estimated by sodium dodecyl sulphate polyacrylamide gel electrophoresis under non-reducing conditions to be about 34 kDa. MBL-SN was shown to be a dimer with two identical subunits of about 17 kDa. The native MBL-SN exists as a tetramer. The physico-chemical properties of MBL-SN indicate that it belongs to C-type mannan-binding lectins. The cDNA encoding MBL-SN was cloned from the total cDNA of S. nudus coelomocytes and encodes a 17-kDa protein of 144 amino acid residues that contains a single carbohydrate-recognition domain of C-type lectins. Prediction of the MBL-SN tertiary structure using comparative modelling revealed that MBL-SN is an ?/?-protein with eight ?-strands and two ?-helices. Comparison of the MBL-SN model with available three-dimensional structures of C-type lectins revealed that they share a common fold pattern. PMID:22696119

  7. LEAPT: Lectin-directed enzyme-activated prodrug therapy

    E-print Network

    Davis, Ben G.

    LEAPT: Lectin-directed enzyme-activated prodrug therapy Mark A. Robinson*, Stuart T. Charlton) administration of a prodrug activated by that predelivered enzyme at the desired site. The carbohydrate structure enzyme activity (0.2 units in hepatocytes) for prodrug therapy, the target of which was switched simply

  8. Membrane adsorbers comprising grafted glycopolymers for targeted lectin binding

    PubMed Central

    Chenette, Heather C.S.; Husson, Scott M.

    2014-01-01

    This work details the design and testing of affinity membrane adsorbers for lectin purifications that incorporate glucose-containing glycopolymers. It is the selective interaction between the sugar residues of the glycopolymer and the complementary carbohydrate-binding domain of the lectin that provides the basis for the isolation and purification of lectins from complex biological media. The design approach used in these studies was to graft glycopolymer ‘tentacles’ from macroporous regenerated cellulose membranes by atom transfer radical polymerization. As shown in earlier studies, this design approach can be used to prepare high-productivity membrane adsorbers. The model lectin, concanavalin A (conA), was used to evaluate membrane performance in bind-and-elute purification, using a low molecular weight sugar for elution. The membrane capacity for binding conA was measured at equilibrium and under dynamic conditions using flow rates of 0.1 and 1.0 mL/min. The first Damkohler number was estimated to relate the adsorption rate to the convective mass transport rate through the membrane bed. It was used to assess whether adsorption kinetics or mass transport contributed the primary limitation to conA binding. Analyses indicate that this system is not limited by the accessibility of the binding sites, but by the inherent rate of adsorption of conA onto the glycopolymer. PMID:25866416

  9. Lectin-modified microchannels for mammalian cell capture and purification

    E-print Network

    Beebe, David J.

    -of-principle demonstra- tion, two cell lines with different binding affinities to the lectin Sambucus nigra agglutinin and Lis 2003). Different mammalian cell lines have different cell surface carbohydrate expression patterns is critical to the study of breast cancer and the development of new treatment strategies (Al-Hajj et al. 2003

  10. Glycosylation Influences the Lectin Activities of the Macrophage Mannose Receptor*

    E-print Network

    Glycosylation Influences the Lectin Activities of the Macrophage Mannose Receptor* Received, University of Oxford, South Parks Road, Oxford OX1 3RE, United Kingdom The mannose receptor (MR) is a heavily mannose internaliza- tion activity, but could internalize sulfated glycans. Accordingly, purified MR

  11. Purification, characterization, and biological activities of broccolini lectin.

    PubMed

    Xu, Pingping; Zhang, Ting; Guo, Xiaolei; Ma, Chungwah; Zhang, Xuewu

    2015-01-01

    Plant lectins have displayed a variety of biological activities. In this study, for the first time, a 27 kDa arabinose- and mannose-specific lectin from Broccolini (Brassica oleracea Italica × Alboglabra), named as BL (Broccolini lectin), was purified by an activity-driven protocol. Mass spectrometry analysis and database search indicated that no matches with any plant lectin were found, but BL contained some peptide fragments (QQQGQQGQQLQQVISR, QQGQQQGQQGQQLQQVISR and VCNIPQVSVCPF QK). BL exhibited hemagglutinating activity against chicken erythrocytes at 4 µg/mL. BL retained full hemagglutinating activity at pH 7-8 and temperature 30-40°C, and had an optimal activity in Ca(2+) solution. Bioactivity assay revealed that BL exhibited dose-dependent inhibition activity on 5 bacterial species with IC50 values of 143.95-486.33 ?g/mL, and on 3 cancer cells with IC50 values of 178.82-350.93 ?g/mL. Notably, 5-fold reduction in IC50 values was observed on normal L-O2 vs cancerous HepG-2 cells (924.35 vs. 178.82 ?g/mL). This suggests that BL should be promising in food and medicine. PMID:25737003

  12. Mushroom lectin protects arsenic induced apoptosis in hepatocytes of rodents.

    PubMed

    Rana, Tanmoy; Bera, Asit Kumar; Das, Subhashree; Bhattacharya, Debasis; Pan, Diganta; Bandyopadhyay, Subhasish; De, Sumanta; Das, Subrata Kumar

    2011-04-01

    Acute and chronic arsenic exposure result in toxicity both in human and animal beings and cause many hepatic and renal manifestations. The present study stated that mushroom lectin prevents arsenic-induced apoptosis. Apoptosis was measured by morphological alterations, cell proliferation index (CPI), phagocytic activity (nitro blue tetrazolium index; NBT), nitric oxide (NO) production, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, DNA fragmentation and caspase-3 activity. Arsenic exposure at 5 ?M in the form of sodium arsenite resulted in significant elevation of deformed cells, NO production, TUNEL stained nuclei of hepatocytes, DNA fragmentation and caspase-3 activity. But the CPI and NBT index were significantly declined in arsenic-treated hepatocytes. The beneficial effect of mushroom lectin at 10 ?g/mL, 20 ?g/mL and 50 ?g/mL) showed increased CPI and phagocytic activity. Mushroom lectin at those concentrations reduced deformed cells, NO production, DNA fragmentation and caspase-3 activity of hepatocytes. But significant better protection was observed in 50 ?g/mL mushroom lectin-treated hepatocytes. This finding may be of therapeutic benefit in people suffering from chronic arsenic exposure. PMID:20507870

  13. Radioimmunoassay for anaphylatoxins: a sensitive method for determining complement activation products in biological fluids

    SciTech Connect

    Wagner, J.L.; Hugli, T.E.

    1984-01-01

    Activation of the blood complement system generates bioactive fragments called anaphylatoxins. The three anaphylatoxins C3a, C4a, and C5a are released during classical pathway activation while only C3a and C5a are released when the alternative pathway of complement is activated. Radioimmunoassays were designed to individually detect and quantitate the activation fragments C3a, C4a, and C5a in biological fluids without interference from the precursor molecules C3, C4, and C5. Kinetics of complement activation in fresh human serum exposed to the activators zymosan, heat-aggregated immunoglobulin, or cobra venom factor were monitored using the radioimmunoassay technique. For the first time, activation of components C3, C4, and C5 was followed simultaneously in a single serum sample. Analysis of the patterns and extent of anaphylatoxin formation during activation in serum may be used to screen for deficiencies or defects in the complement cascade. Levels of the anaphylatoxins in freshly drawn serum were much higher than levels detected in EDTA-plasma. Detection of low-level complement activation in patient's blood, urine, or synovial fluid, using anaphylatoxin formation as an indicator, may prove useful in signaling numerous forms of inflammatory reactions. The demonstration of anaphylatoxins in clinical samples is being recognized as a valuable diagnostic tool in monitoring the onset of immune disease.

  14. Platelets and the complement cascade in atherosclerosis

    PubMed Central

    Patzelt, Johannes; Verschoor, Admar; Langer, Harald F.

    2015-01-01

    Atherosclerosis and its late sequels are still the number one cause of death in western societies. Platelets are a driving force not only during the genesis of atherosclerosis, but especially in its late stages, as evidenced by complications such as arterial thrombosis, myocardial infarction, and ischemic stroke. Atherosclerosis is increasingly recognized as an inflammatory disease, influenced by various immune mechanisms. The complement system is part of our innate immune system, and its diverse roles in atherosclerosis have become evident over the past years. In this review we identify points of intersection between platelets and the complement system and discuss their relevance for atherosclerosis. Specifically, we will focus on roles for platelets in the onset as well as progression of the disease, a possible dual role for complement in the genesis and development of atherosclerosis, and review emerging literature revealing previously unrecognized cross-talk between platelets and the complement system and discuss its possible impact for atherosclerosis. Finally, we identify limitations of current research approaches and discuss perspectives of complement modulation in the control of the disease. PMID:25784879

  15. Studies on lectins. XXXVI. Properties of some lectins prepared by affinity chromatography on O-glycosyl polyacrylamide gels.

    PubMed

    Horejsí, V; Kocourek, J

    1978-01-18

    A number of lectins has been purified by affinity chromatography on O-glycosyl polyacrylamide gels. The lectins isolated (and the particular sugar ligands used in the affinity carriers) are as follows: Anguilla anguilla, serum (alpha-L-fucosyl-), Vicia cracca, seeds; Phaseolus lunatus, seeds; Glycine soja, seeds; Dolichos biflorus, seeds; Maclura pomifera, seeds; Sarothamnus scoparius, seeds; Helix pomatia, ablumin glands; Clitocybe nebularis, fruiting bodies (all N-acetyl-alpha-D-galactosaminyl-); Ricinus communis, seeds (beta-lactosyl-); Ononis spinosa, root; Fomes fomentarius, fruiting bodies; Marasmius oreades, fruiting bodies (all alpha-D-galactosyl-), Canavalia ensiformis, seeds, (i.e., concanavalin A) (alpha-D-glucosyl-). Physicochemical properties of Glycine soja, Dolichos biflorus, Phaseolus lunatus, Helix Pomatia and Ricinus communis lectins corresponded well to properties of the preparations studied earlier by other workers. For the other purified lectins the essential physiochemical data (sedimentation coefficient, molecular weight, subunit composition, electrophoretic patterns, amino acid composition, carbohydrate content, isoelectric point) were established and their precipitating, hemagglutinating and mitogenic activities determined. PMID:563738

  16. Protective T Cell–Independent Antiviral Antibody Responses Are Dependent on Complement

    PubMed Central

    Ochsenbein, Adrian F.; Pinschewer, Daniel D.; Odermatt, Bernhard; Carroll, Michael C.; Hengartner, Hans; Zinkernagel, Rolf M.

    1999-01-01

    Complement is part of the innate immune system and one of the first lines of host defense against infections. Its importance was evaluated in this study in virus infections in mice deficient either in soluble complement factors (C3?/?, C4?/?) or in the complement signaling complex (complement receptor [CR]2?/?, CD19?/?). The induction of the initial T cell–independent neutralizing immunoglobulin (Ig)M antibody response to vesicular stomatitis virus (VSV), poliomyelitis virus, and recombinant vaccinia virus depended on efficient antigen trapping by CR3 and -4–expressing macrophages of the splenic marginal zone. Neutralizing IgM and IgG antibody responses were largely independent of CR2-mediated stimulation of B cells when mice were infected with live virus. In contrast, immunizations with nonreplicating antigens revealed an important role of B cell stimulation via CR2 in the switch to IgG. The complement cascade was activated after infection with VSV via the classical pathway, and active complement cleavage products augmented the effector function of neutralizing IgM and IgG antibodies to VSV by a factor of 10–100. Absence of the early neutralizing antibody responses, together with the reduced efficiency of neutralizing IgM in C3?/? mice, led to a drastically enhanced susceptibility to disease after infection with VSV. PMID:10523614

  17. Protective T cell-independent antiviral antibody responses are dependent on complement.

    PubMed

    Ochsenbein, A F; Pinschewer, D D; Odermatt, B; Carroll, M C; Hengartner, H; Zinkernagel, R M

    1999-10-18

    Complement is part of the innate immune system and one of the first lines of host defense against infections. Its importance was evaluated in this study in virus infections in mice deficient either in soluble complement factors (C3(-/-), C4(-/-)) or in the complement signaling complex (complement receptor [CR]2(-/-), CD19(-/-)). The induction of the initial T cell-independent neutralizing immunoglobulin (Ig)M antibody response to vesicular stomatitis virus (VSV), poliomyelitis virus, and recombinant vaccinia virus depended on efficient antigen trapping by CR3 and -4-expressing macrophages of the splenic marginal zone. Neutralizing IgM and IgG antibody responses were largely independent of CR2-mediated stimulation of B cells when mice were infected with live virus. In contrast, immunizations with nonreplicating antigens revealed an important role of B cell stimulation via CR2 in the switch to IgG. The complement cascade was activated after infection with VSV via the classical pathway, and active complement cleavage products augmented the effector function of neutralizing IgM and IgG antibodies to VSV by a factor of 10-100. Absence of the early neutralizing antibody responses, together with the reduced efficiency of neutralizing IgM in C3(-/-) mice, led to a drastically enhanced susceptibility to disease after infection with VSV. PMID:10523614

  18. Complement and macrophage crosstalk during process of angiogenesis in tumor progression.

    PubMed

    Khan, M Afzal; Assiri, A M; Broering, D C

    2015-01-01

    The complement system, which contains some of the most potent pro-inflammatory mediators in the tissue including the anaphylatoxins C3a and C5a are the vital parts of innate immunity. Complement activation seems to play a more critical role in tumor development, but little attention has been given to the angiogenic balance of the activated complement mediators and macrophage polarization during tumor progression. The tumor growth mainly supported by the infiltration of M2- tumor-associated macrophages, and high levels of C3a and C5a, whereas M1-macrophages contribute to immune-mediated tumor suppression. Macrophages express a cognate receptors for both C3a and C5a on their cell surface, and specific binding of C3a and C5a affects the functional modulation and angiogenic properties. Activation of complement mediators induce angiogenesis, favors an immunosuppressive microenvironment, and activate cancer-associated signaling pathways to assist chronic inflammation. In this review manuscript, we highlighted the specific roles of complement activation and macrophage polarization during uncontrolled angiogenesis in tumor progression, and therefore blocking of complement mediators would be an alternative therapeutic option for treating cancer. PMID:26198107

  19. Complement-Related Proteins Control the Flavivirus Infection of Aedes aegypti by Inducing Antimicrobial Peptides

    PubMed Central

    Xiao, Xiaoping; Liu, Yang; Zhang, Xiaoyan; Wang, Jing; Li, Zuofeng; Pang, Xiaojing; Wang, Penghua; Cheng, Gong

    2014-01-01

    The complement system functions during the early phase of infection and directly mediates pathogen elimination. The recent identification of complement-like factors in arthropods indicates that this system shares common ancestry in vertebrates and invertebrates as an immune defense mechanism. Thioester (TE)-containing proteins (TEPs), which show high similarity to mammalian complement C3, are thought to play a key role in innate immunity in arthropods. Herein, we report that a viral recognition cascade composed of two complement-related proteins limits the flaviviral infection of Aedes aegypti. An A. aegypti macroglobulin complement-related factor (AaMCR), belonging to the insect TEP family, is a crucial effector in opposing the flaviviral infection of A. aegypti. However, AaMCR does not directly interact with DENV, and its antiviral effect requires an A. aegypti homologue of scavenger receptor-C (AaSR-C), which interacts with DENV and AaMCR simultaneously in vitro and in vivo. Furthermore, recognition of DENV by the AaSR-C/AaMCR axis regulates the expression of antimicrobial peptides (AMPs), which exerts potent anti-DENV activity. Our results both demonstrate the existence of a viral recognition pathway that controls the flaviviral infection by inducing AMPs and offer insights into a previously unappreciated antiviral function of the complement-like system in arthropods. PMID:24722701

  20. Applying complement therapeutics to rare diseases.

    PubMed

    Reis, Edimara S; Mastellos, Dimitrios C; Yancopoulou, Despina; Risitano, Antonio M; Ricklin, Daniel; Lambris, John D

    2015-12-01

    Around 350 million people worldwide suffer from rare diseases. These may have a genetic, infectious, or autoimmune basis, and several include an inflammatory component. Launching of effective treatments can be very challenging when there is a low disease prevalence and limited scientific insights into the disease mechanisms. As a key trigger of inflammatory processes, complement has been associated with a variety of diseases and has become an attractive therapeutic target for conditions involving inflammation. In view of the clinical experience acquired with drugs licensed for the treatment of rare diseases such as hereditary angioedema and paroxysmal nocturnal hemoglobinuria, growing evidence supports the safety and efficacy of complement therapeutics in restoring immune balance and preventing aggravation of clinical outcomes. This review provides an overview of the candidates currently in the pharmaceutical pipeline with potential to treat orphan diseases and discusses the molecular mechanisms triggered by complement involved with the disease pathogenesis. PMID:26341313

  1. Mannose-Binding Lectin Levels and Carotid Intima-Media Thickness in Type 2 Diabetic Patients.

    PubMed

    Káplár, Miklós; Sweni, Shah; Kulcsár, Julianna; Cogoi, Barbara; Esze, Regina; Somodi, Sándor; Papp, Mária; Oláh, László; Magyar, Mária Tünde; Szabó, Katalin; Czuriga-Kovács, Katalin Réka; Hársfalvi, Jolán; Paragh, György

    2016-01-01

    Introduction. Mannose-binding lectin (MBL) activates complement system and has been suggested to play a role in vascular complications in diabetics. Carotid intima-media thickness (cIMT) detects subclinical atherosclerosis. We evaluated the association of MBL and IMT in type 2 diabetic (T2DM) patients. Methods. Serum MBL levels and cIMT were measured in a total of 103 diabetics and in 98 age-matched healthy controls. Results. There was no significant difference in MBL level in T2DM versus controls. As expected, IMT was significantly higher in T2DM patients than in controls (P = 0.001). In T2DM, the lowest cIMT was seen in patients with normal MBL level (500-1000) while cIMT continuously increased with both high MBL and absolute MBL deficiency states. This was especially significant in high MBL versus normal MBL T2DM patients (P = 0.002). According to multiple regression analysis the main predictors of IMT in T2DM are age (P < 0.003), ApoA level (P = 0.023), and the MBL (P = 0.036). Conclusions. Our results suggest a dual role of MBL as a risk factor for cIMT in T2DM. MBL may also be used as a marker of macrovascular disease, as both low and high levels indicate the susceptibility for atherosclerosis in T2DM. PMID:26640806

  2. The role of mannose binding lectin on fever episodes in pediatric oncology patients.

    PubMed

    Fekete, Ferenc; Fadgyas, Balázs; Papp, Éva; Szilágyi, Ágnes; Prohászka, Zoltán; Müller, Brigitta; Kovács, Gábor

    2016-01-01

    Despite significant changes in pediatric oncological therapy, mortality is still high, mainly due to infections. Complement system as an ancient immune defense against microorganisms plays a significant role in surmounting infections, therefore, deficiency of its components may have particular importance in malignancies. The present paper assesses the effect of promoter (X/Y) and exon 1 (A/0) polymorphisms of the MBL2 gene altering mannose binding lectin (MBL) serum level in pediatric oncological patients with febrile neutropenia. Furthermore, frequency distribution of MBL2 alleles in children with malignancies and age-matched controls was analysed. Fifty-four oncohematological patients and 53 children who had undergone pediatric surgery were enrolled into this retrospective study. No significant differences were found in the frequency of MBL2 alleles between the hemato-oncologic and control group. The average duration of fever episodes was significantly shorter (p = 0.035) in patients carrying genotypes (AY/AY and AY/AX) that encode normal MBL level, compared to individuals with genotypes associated with lower functional MBL level (AX/AX, AY/0, AX/0, or 0/0) (days, median (IQ range) 3.7(0-5.4) vs. 5.0(3.8-6.6), respectively). In conclusion, our data suggest that MBL2 genotypes may influence the course of febrile neutropenia in pediatric patients with malignancies, and may contribute to clarification of the importance of MBL in infections. PMID:26433879

  3. Different Host Complement Systems and Their Interactions with Saliva from Lutzomyia longipalpis (Diptera, Psychodidae) and Leishmania infantum Promastigotes

    PubMed Central

    Mendes-Sousa, Antonio Ferreira; Nascimento, Alexandre Alves Sousa; Queiroz, Daniel Costa; Vale, Vladimir Fazito; Fujiwara, Ricardo Toshio; Araújo, Ricardo Nascimento; Pereira, Marcos Horácio; Gontijo, Nelder Figueiredo

    2013-01-01

    Background Lutzomyia longipalpis is the vector of Leishmania infantum in the New World, and its saliva inhibits classical and alternative human complement system pathways. This inhibition is important in protecting the insect´s midgut from damage by the complement. L. longipalpis is a promiscuous blood feeder and must be protected against its host’s complement. The objective of this study was to investigate the action of salivary complement inhibitors on the sera of different host species, such as dogs, guinea pigs, rats and chickens, at a pH of 7.4 (normal blood pH) and 8.15 (the midgut pH immediately after a blood meal). We also investigated the role of the chicken complement system in Leishmania clearance in the presence and absence of vector saliva. Results The saliva was capable of inhibiting classical pathways in dogs, guinea pigs and rats at both pHs. The alternative pathway was not inhibited except in dogs at a pH of 8.15. The chicken classical pathway was inhibited only by high concentrations of saliva and it was better inhibited by the midgut contents of sand flies. Neither the saliva nor the midgut contents had any effect on the avian alternative pathway. Fowl sera killed L. infantum promastigotes, even at a low concentration (2%), and the addition of L. longipalpis saliva did not protect the parasites. The high body temperature of chickens (40°C) had no effect on Leishmania viability during our assays. Conclusion Salivary inhibitors act in a species-specific manner. It is important to determine their effects in the natural hosts of Leishmania infantum because they act on canid and rodent complements but not on chickens (which do not harbour the parasite). Moreover, we concluded that the avian complement system is the probable mechanism through which chickens eliminate Leishmania and that their high body temperature does not influence this parasite. PMID:24255715

  4. Disruption of the C. elegans Intestinal Brush Border by the Fungal Lectin CCL2 Phenocopies Dietary Lectin Toxicity in Mammals

    PubMed Central

    Stutz, Katrin; Kaech, Andres; Aebi, Markus; Künzler, Markus; Hengartner, Michael O.

    2015-01-01

    Lectins are non-immunoglobulin carbohydrate-binding proteins without enzymatic activity towards the bound carbohydrates. Many lectins of e.g. plants or fungi have been suggested to act as toxins to defend the host against predators and parasites. We have previously shown that the Coprinopsis cinerea lectin 2 (CCL2), which binds to ?1,3-fucosylated N-glycan cores, is toxic to Caenorhabditis elegans and results in developmental delay and premature death. In this study, we investigated the underlying toxicity phenotype at the cellular level by electron and confocal microscopy. We found that CCL2 directly binds to the intestinal apical surface and leads to a highly damaged brush border with loss of microvilli, actin filament depolymerization, and invaginations of the intestinal apical plasma membrane through gaps in the terminal web. We excluded several possible toxicity mechanisms such as internalization and pore-formation, suggesting that CCL2 acts directly on intestinal apical plasma membrane or glycocalyx proteins. A genetic screen for C. elegans mutants resistant to CCL2 generated over a dozen new alleles in bre 1, ger 1, and fut 1, three genes required for the synthesis of the sugar moiety recognized by CCL2. CCL2-induced intestinal brush border defects in C. elegans are similar to the damage observed previously in rats after feeding the dietary lectins wheat germ agglutinin or concanavalin A. The evolutionary conserved reaction of the brush border between mammals and nematodes might allow C. elegans to be exploited as model organism for the study of dietary lectin-induced intestinal pathology in mammals. PMID:26057124

  5. A Preliminary Genetic Analysis of Complement 3 Gene and Schizophrenia

    PubMed Central

    Zhang, Jiangtao; Tang, Wenxin; Lu, Weihong; Zhang, Chen

    2015-01-01

    Complement pathway activation was found to occur frequently in schizophrenia, and complement 3 (C3) plays a major role in this process. Previous studies have provided evidence for the possible role of C3 in the development of schizophrenia. In this study, we hypothesized that the gene encoding C3 (C3) may confer susceptibility to schizophrenia in Han Chinese. We analyzed 7 common single nucleotide polymorphisms (SNPs) of C3 in 647 schizophrenia patients and 687 healthy controls. Peripheral C3 mRNA expression level was measured in 23 drug-naďve patients with schizophrenia and 24 controls. Two SNPs (rs1047286 and rs2250656) that deviated from Hardy-Weinberg equilibrium were excluded for further analysis. Among the remaining 5 SNPs, there was no significant difference in allele and genotype frequencies between the patient and control groups. Logistic regression analysis showed no significant SNP-gender interaction in either dominant model or recessive model. There was no significant difference in the level of peripheral C3 expression between the drug-naďve schizophrenia patients and healthy controls. In conclusion, the results of this study do not support C3 as a major genetic susceptibility factor in schizophrenia. Other factors in AP may have critical roles in schizophrenia and be worthy of further investigation. PMID:26305563

  6. Smoke Exposure Causes Endoplasmic Reticulum Stress and Lipid Accumulation in Retinal Pigment Epithelium through Oxidative Stress and Complement Activation*

    PubMed Central

    Kunchithapautham, Kannan; Atkinson, Carl; Rohrer, Bärbel

    2014-01-01

    Age-related macular degeneration (AMD) is a complex disease caused by genetic and environmental factors, including genetic variants in complement components and smoking. Smoke exposure leads to oxidative stress, complement activation, endoplasmic reticulum (ER) stress, and lipid dysregulation, which have all been proposed to be associated with AMD pathogenesis. Here we examine the effects of smoke exposure on the retinal pigment epithelium (RPE). Mice were exposed to cigarette smoke or filtered air for 6 months. RPE cells grown as stable monolayers were exposed to 5% cigarette smoke extract (CSE). Effects of smoke were determined by biochemical, molecular, and histological measures. Effects of the alternative pathway (AP) of complement and complement C3a anaphylatoxin receptor signaling were analyzed using knock-out mice or specific inhibitors. ER stress markers were elevated after smoke exposure in RPE of intact mice, which was eliminated in AP-deficient mice. To examine this relationship further, RPE monolayers were exposed to CSE. Short term smoke exposure resulted in production and release of complement C3, the generation of C3a, oxidative stress, complement activation on the cell membrane, and ER stress. Long term exposure to CSE resulted in lipid accumulation, and secretion. All measures were reversed by blocking C3a complement receptor (C3aR), alternative complement pathway signaling, and antioxidant therapy. Taken together, our results provide clear evidence that smoke exposure results in oxidative stress and complement activation via the AP, resulting in ER stress-mediated lipid accumulation, and further suggesting that oxidative stress and complement act synergistically in the pathogenesis of AMD. PMID:24711457

  7. Smoke exposure causes endoplasmic reticulum stress and lipid accumulation in retinal pigment epithelium through oxidative stress and complement activation.

    PubMed

    Kunchithapautham, Kannan; Atkinson, Carl; Rohrer, Bärbel

    2014-05-23

    Age-related macular degeneration (AMD) is a complex disease caused by genetic and environmental factors, including genetic variants in complement components and smoking. Smoke exposure leads to oxidative stress, complement activation, endoplasmic reticulum (ER) stress, and lipid dysregulation, which have all been proposed to be associated with AMD pathogenesis. Here we examine the effects of smoke exposure on the retinal pigment epithelium (RPE). Mice were exposed to cigarette smoke or filtered air for 6 months. RPE cells grown as stable monolayers were exposed to 5% cigarette smoke extract (CSE). Effects of smoke were determined by biochemical, molecular, and histological measures. Effects of the alternative pathway (AP) of complement and complement C3a anaphylatoxin receptor signaling were analyzed using knock-out mice or specific inhibitors. ER stress markers were elevated after smoke exposure in RPE of intact mice, which was eliminated in AP-deficient mice. To examine this relationship further, RPE monolayers were exposed to CSE. Short term smoke exposure resulted in production and release of complement C3, the generation of C3a, oxidative stress, complement activation on the cell membrane, and ER stress. Long term exposure to CSE resulted in lipid accumulation, and secretion. All measures were reversed by blocking C3a complement receptor (C3aR), alternative complement pathway signaling, and antioxidant therapy. Taken together, our results provide clear evidence that smoke exposure results in oxidative stress and complement activation via the AP, resulting in ER stress-mediated lipid accumulation, and further suggesting that oxidative stress and complement act synergistically in the pathogenesis of AMD. PMID:24711457

  8. Complement activation is involved in the hepatic injury caused by high-dose exposure of mice to perfluorooctanoic acid.

    PubMed

    Botelho, Salomé Calado; Saghafian, Maryam; Pavlova, Svetlana; Hassan, Moustapha; DePierre, Joseph W; Abedi-Valugerdi, Manuchehr

    2015-06-01

    High-dose exposure of mice to perfluorooctanoate (PFOA) induces both hepatotoxicity and immunotoxicity. Here, we characterized the effects of 10-day dietary treatment with PFOA (0.002-0.02%, w/w) on the liver and complement system of male C57BL/6 mice. At all four doses, this compound caused hepatomegaly and reduced the serum level of triglycerides (an indicator for activation of the peroxisome proliferator-activated receptor-alpha (PPAR?)). At the highest dose (0.02%, w/w), this hepatomegaly was associated with the hepatic injury, as reflected in increased activity of alanine aminotranferase (ALAT) in the serum, severe hepatocyte hypertrophy and hepatocellular necrosis. PFOA-induced hepatic injury was associated with in vivo activation of the complement system as indicated by (i) significant attenuation of the serum activities of both the classical and alternative pathways; (ii) a marked reduction in the serum level of the complement factor C3; and (iii) deposition of the complement factor C3 fragment (C3a) in the hepatic parenchyma. PFOA did not activate the alternative pathway of complement in vitro. At doses lower than 0.02%, PFOA induced hepatocyte hypertrophy without causing liver injury or activating complement. These results reveal substantial involvement of activation of complement in the pathogenesis of PFOA-induced hepatotoxicity. PMID:25108893

  9. Characterization of the third component of complement (C3) after activation by cigarette smoke

    SciTech Connect

    Kew, R.R.; Ghebrehiwet, B.; Janoff, A.

    1987-08-01

    Activation of lung complement by tobacco smoke may be an important pathogenetic factor in the development of pulmonary emphysema in smokers. We previously showed that cigarette smoke can modify C3 and activate the alternative pathway of complement in vitro. However, the mechanism of C3 activation was not fully delineated in these earlier studies. In the present report, we show that smoke-treated C3 induces cleavage of the alternative pathway protein, Factor B, when added to serum containing Mg-EGTA. This effect of cigarette smoke is specific for C3 since smoke-treated C4, when added to Mg-EGTA-treated serum, fails to activate the alternative pathway and fails to induce Factor B cleavage. Smoke-modified C3 no longer binds significant amounts of (/sup 14/C)methylamine (as does native C3), and relatively little (/sup 14/C)methylamine is incorporated into its alpha-chain. Thus, prior internal thiolester bond cleavage appears to have occurred in C3 activated by cigarette smoke. Cigarette smoke components also induce formation of noncovalently associated, soluble C3 multimers, with a Mr ranging from 1 to 10 million. However, prior cleavage of the thiolester bond in C3 with methylamine prevents the subsequent formation of these smoke-induced aggregates. These data indicate that cigarette smoke activates the alternative pathway of complement by specifically modifying C3 and that these modifications include cleavage of the thiolester bond in C3 and formation of noncovalently linked C3 multimers.

  10. Purification, crystallization and preliminary X-ray crystallographic analysis of rice lectin from Oryza sativa

    SciTech Connect

    Huang, Yen-Chieh; Lin, Yi-Hung; Shih, Chia-Hao; Shih, Chun-Liang; Chang, Tschining; Chen, Chun-Jung

    2006-02-01

    Rice lectin was crystallized and analyzed by X-ray crystallography. Lectins with sugar-binding specificity are widely distributed in higher plants and various other species. The expression of rice lectin from Oryza sativa is up-regulated in the growing coleoptile when anaerobic stress persists. A rice lectin of molecular weight 15.2 kDa has been crystallized using the hanging-drop vapour-diffusion method. From the diffraction of the lectin crystals at 1.93 Ĺ resolution, the unit cell belongs to space group P3{sub 1}, with unit-cell parameters a = 98.58, b = 98.58, c = 44.72 Ĺ. Preliminary analysis indicates that there are two lectin molecules in an asymmetric unit with a large solvent content, 70.1%.

  11. Transcriptomic response of cowpea bruchids to N-acetylglucosamine-specific lectins.

    PubMed

    Wang, Li-Hua; Chi, Yong Hun; Guo, Feng-Guang; Li-Byarlay, Hongmei; Balfe, Susan; Fang, Ji-Chao; Pittendrigh, Barry R; Zhu-Salzman, Keyan

    2015-02-01

    Griffonia simplicifolia lectin II (GSII) and wheat germ agglutinin (WGA) are N-acetylglucosamine-binding lectins. Previous studies demonstrated that they have anti-insect activity, a property potentially useful in pest control. To gain some insight into the insect response to dietary lectins, we performed transcriptomic analysis using the cowpea bruchid (Callosobruchus maculatus) midgut microarray platform we built. Compared to the nonnutritional cellulose treatment, dietary lectins induced more profound changes in gene expression. Ingestion of relatively high doses of lectins for 24 h resulted in alteration of gene expression involved in sugar and lipid metabolism, transport, development, defense, and stress tolerance. Metabolic genes were largely downregulated. Moreover, we observed disorganized microvilli resulting from ingestion of WGA. This morphological change is consistent with the lectin-induced changes in genes related to midgut epithelial cell repair. In addition, suboptimal nutrient conditions may serve as a stress signal to trigger senescence processes, leading to growth arrest and developmental delay. PMID:24446316

  12. Lectin Activation in Giardia lamblia by Host Protease: A Novel Host-Parasite Interaction

    NASA Astrophysics Data System (ADS)

    Lev, Boaz; Ward, Honorine; Keusch, Gerald T.; Pereira, Miercio E. A.

    1986-04-01

    A lectin in Giardia lamblia was activated by secretions from the human duodenum, the environment where the parasite lives. Incubation of the secretions with trypsin inhibitors prevented the appearance of lectin activity, implicating proteases as the activating agent. Accordingly, lectin activation was also produced by crystalline trypsin and Pronase; other proteases tested were ineffective. When activated, the lectin agglutinated intestinal cells to which the parasite adheres in vivo. The lectin was most specific to mannose-6-phosphate and apparently was bound to the plasma membrane. Activation of a parasite lectin by a host protease represents a novel mechanism of hostparasite interaction and may contribute to the affinity of Giardia lamblia to the infection site.

  13. Lectin binding to surface Ig variable regions provides a universal persistent activating signal for follicular lymphoma cells.

    PubMed

    Linley, Adam; Krysov, Sergey; Ponzoni, Maurilio; Johnson, Peter W; Packham, Graham; Stevenson, Freda K

    2015-10-15

    The vast majority of cases of follicular lymphoma (FL), but not normal B cells, acquire N-glycosylation sites in the immunoglobulin variable regions during somatic hypermutation. Glycans added to sites are unusual in terminating at high mannoses. We showed previously that the C-type lectins, dendritic cell-specific intercellular adhesion molecule-3 grabbing non-integrin (DC-SIGN) and mannose receptor, bound to FL surface immunoglobulin (sIg), generating an intracellular Ca(2+) flux. We have now mapped further intracellular pathways activated by DC-SIGN in a range of primary FL cells with detection of phosphorylated ERK1/2, AKT, and PLC?2. The SYK inhibitor (tamatinib) or the BTK inhibitor (ibrutinib) each blocked phosphorylation. Activation by DC-SIGN occurred in both IgM(+) and IgG(+) cases and led to upregulation of MYC expression, with detection in vivo observed in lymph nodes. Unlike cells of chronic lymphocytic leukemia, FL cells expressed relatively high levels of sIg, unchanged by long-term incubation in vitro, indicating no antigen-mediated downregulation in vivo. In contrast, expression of CXCR4 increased in vitro. Engagement of sIg in FL cells or normal B cells by anti-Ig led to endocytosis in vitro as expected, but DC-SIGN, even when cross-linked, did not lead to significant endocytosis of sIg. These findings indicate that lectin binding generates signals via sIg but does not mediate endocytosis, potentially maintaining a supportive antigen-independent signal in vivo. Location of DC-SIGN in FL tissue revealed high levels in sinusoidlike structures and in some colocalized mononuclear cells, suggesting a role for lectin-expressing cells at this site. PMID:26194765

  14. Complements of Multivalued Functions Stephen Fenner \\Lambda

    E-print Network

    Green, Frederic

    if it is polyno­ mial length­bounded and graph(f) belongs to coNP. Given this symmetry, graphs of functions in NPMV are in NP while graphs of functions in coNPMV are in coNP, and given what we know about NP and coComplements of Multivalued Functions Stephen Fenner \\Lambda University of Southern Maine Frederic

  15. 21 CFR 866.4100 - Complement reagent.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Complement reagent. 866.4100 Section 866.4100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents §...

  16. 21 CFR 866.4100 - Complement reagent.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Complement reagent. 866.4100 Section 866.4100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents §...

  17. 21 CFR 866.4100 - Complement reagent.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Complement reagent. 866.4100 Section 866.4100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents §...

  18. 21 CFR 866.4100 - Complement reagent.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Complement reagent. 866.4100 Section 866.4100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents §...

  19. Complement Evasion by S. aureus Surface Proteins 

    E-print Network

    Kang, Mingsong

    2014-08-28

    and fibrinogen-binding MSCRAMM Bbq/S drE using the hemolysis and the C4b deposition ELISA-type essay to analyze complement activation and a serial biochemical and immunological approaches such as ELISA, biacore and IP assays to investigate the binding...

  20. 21 CFR 866.4100 - Complement reagent.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Complement reagent. 866.4100 Section 866.4100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents §...

  1. 21 CFR 866.4100 - Complement reagent.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...reagent is a device that consists of complement, a naturally occurring serum protein from any warm-blooded animal such as guinea pigs, that may be included as a component part of serological test kits used in the diagnosis of disease. (b)...

  2. 21 CFR 866.4100 - Complement reagent.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...reagent is a device that consists of complement, a naturally occurring serum protein from any warm-blooded animal such as guinea pigs, that may be included as a component part of serological test kits used in the diagnosis of disease. (b)...

  3. 21 CFR 866.4100 - Complement reagent.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...reagent is a device that consists of complement, a naturally occurring serum protein from any warm-blooded animal such as guinea pigs, that may be included as a component part of serological test kits used in the diagnosis of disease. (b)...

  4. Visualization of Allostery in P-Selectin Lectin Domain Using MD Simulations

    PubMed Central

    Lü, Shouqin; Zhang, Yan; Long, Mian

    2010-01-01

    Allostery of P-selectin lectin (Lec) domain followed by an epithelial growth factor (EGF)-like domain is essential for its biological functionality, but the underlying pathways have not been well understood. Here the molecular dynamics simulations were performed on the crystallized structures to visualize the dynamic conformational change for state 1 (S1) or state 2 (S2) Lec domain with respective bent (B) or extended (E) EGF orientation. Simulations illustrated that both S1 and S2 conformations were unable to switch from one to another directly. Instead, a novel S1' conformation was observed from S1 when crystallized B-S1 or reconstructed “E-S1” structure was employed, which was superposed well with that of equilibrated S1 Lec domain alone. It was also indicated that the corresponding allosteric pathway from S1 to S1' conformation started with the separation between residues Q30 and K67 and terminated with the release of residue N87 from residue C109. These results provided an insight into understanding the structural transition and the structure-function relationship of P-selectin allostery. PMID:21170343

  5. The isolation of a lectin-like molecule from Corynebacterium parvum (NCTC 10390).

    PubMed

    Bagg, J; Poxton, I R; Weir, D M

    1981-09-01

    A mannose specific lectin has been isolated by affinity chromatography from the cell wall of C. parvum. Polyacrylamide gel electrophoresis indicates that the lectin molecules lie in the molecular weight range 57,000--72,000. It appears that C. parvum like E. coli and salmonellae express lectins that bind to cells expressing mannose in their membranes. This may partly account for the interaction between C. parvum and the macrophage leading to the various immunological phenomena associated with C. parvum administration. PMID:7288872

  6. Clusterin and Complement Activation in Exfoliation Glaucoma

    PubMed Central

    Doudevski, Ivo; Rostagno, Agueda; Cowman, Mary; Liebmann, Jeffrey; Ritch, Robert; Ghiso, Jorge

    2014-01-01

    Purpose. The study was done to better understand the biological significance of clusterin co-localization with the exfoliation deposits (XF deposits), and provide insight into a pathogenic mechanism involving activation of the complement system and its pro-inflammatory consequences in patients with exfoliation glaucoma. Methods. Exfoliation lens deposits were analyzed by high resolution atomic force microscopy imaging and confocal immunofluorescence. Levels of clusterin and vitronectin, as well as of the complement activation products C3a and soluble C5b-9, were assessed via ELISA. Results. Atomic-force microscopy examination of lenses with exfoliation syndrome (XFS) revealed a dense fibrillar network on the anterior, aqueous-bathed surface of the lens, while the epithelial side displayed no discernible structural features at the same resolution. Clusterin colocalized with XF deposits, demonstrating integral association with the fibrils. Levels of activation-derived complement components C3a and soluble C5b-9, as well as the complement inhibitors clusterin and vitronectin, were found significantly elevated (1.7-fold, P < 0.05; 4.1-fold, P < 0.05; 1.8-fold, P < 0.01; and 3.0-fold, P < 0.01, respectively) in aqueous humor from glaucoma patients with XFS compared to non-XFS glaucoma controls. Conclusions. The data provide compelling evidence for the activation of the complement system in XFS, highlighting the generation of subproducts with potent proinflammatory activity, which are capable of triggering and chronically maintaining levels of subclinical inflammation, suggesting novel targets for therapeutic intervention. The colocalization of clusterin in exfoliation fibrils suggests a failed attempt to prevent tissue accumulation of protein aggregates, as seen in other protein folding disorders, likely due to the abnormal high levels of misfolded proteins overwhelming its chaperone capacity. PMID:24550356

  7. Engineering of human complement component C3 for catalytic inhibition of complement.

    PubMed

    Kölln, Johanna; Bredehorst, Reinhard; Spillner, Edzard

    2005-04-15

    As a novel therapeutic approach in complement-mediated pathologies, we recently developed a human C3 derivative capable of obliterating functional complement by a catalytic, non-inhibitory mechanism. In this derivative, the C-terminal region of hC3 was substituted by a 275 amino acid sequence derived from the corresponding sequence of cobra venom factor (CVF), a complement-activating C3b homologue from snake venom. In this study, we replaced shorter C-terminal sequences of hC3 by corresponding CVF sequences to further reduce potential immunogenicity and to identify domains essential for the formation of functionally stable C3 convertases. In one of these derivatives that is still capable of obliterating functional complement in vitro, the non-human portion could be reduced to a small domain located in the C-terminus of different complement proteins. This conserved NTR/C345C motif is known to be involved in assembly of different convertases of the complement system. These results suggest a major role of the C345C domain in the regulation of the half-life of the C3 convertase. Moreover, its overall identity of 96% to human C3 renders this derivative a promising candidate for therapeutic intervention in complement-mediated pathologies. PMID:15790508

  8. Functional Recombinants Designed from a Fetuin/Asialofetuin-Specific Marine Algal Lectin, Rhodobindin

    PubMed Central

    Han, Jong Won; Jung, Min Gui; Shim, Eun Young; Shim, Jun Bo; Kim, Young Min; Kim, Gwang Hoon

    2015-01-01

    Plant lectins have attracted much attention for biomedical applications including targeted drug delivery system and therapy against tumors and microbial infections. The main problem of using lectins as a biomedical tool is a batch-to-batch variation in isoforms content. The production of lectins using recombination tools has the advantage of obtaining high amounts of proteins with more precise properties, but there are only a handful of functional recombinant lectins presently available. A fetuin/asialo-fetuin specific lectin, Rhodobindin, has unique tandem repeats structure which makes it useful in exploiting for recombinant lectin. We developed three functional recombinant lectins using E. coli expression system: one from full cDNA sequence and two from fragmentary sequences of Rhodobindin. Hemagglutinating activity and solubility of the recombinant lectins were highest at OD 0.7 cell concentration at 20 °C. The optimized process developed in this study was suitable for the quality-controlled production of high amounts of soluble recombinant lectins. PMID:25871294

  9. Purification and characterization of a novel plant lectin from Pinellia ternata with antineoplastic activity.

    PubMed

    Zuo, Zhenyu; Fan, Handong; Wang, Xue; Zhou, Wei; Li, Lingling

    2012-01-01

    A novel Pinellia ternata lectin was purified from the bulbs of a Chinese herb Pinellia ternata using a combination of hydrophobic chromatography and DEAE-ion exchange chromatography. The lectin was found to be a homodimer of 12093.3?Da subunits as determined by gel filtration and MS. Biochemical characterization of the lectin revealed the existence of a glycoprotein, which contains 3.22% neutral sugars. The N-terminal 10-amino acid sequence of the lectin, QGVNISGQVK, has not been reported for other lectins. The lectin had a special agglutinating activity with mouse erythrocytes at a minimum concentration of 8.0 ug/ml. The lectin was stable in the pH range of pH 5-12 and temperatures up to 80°C for 30?min. The results of MTT experiment showed that the lectin had significant effect towards tumor cells, the maximum inhibition of cell proliferation with Sarcoma 180, HeLa and K562 cell line were 85.2%, 74.6% and 59.4% respectively. Experimental therapy in vivo also showed that PTL apparently inhibited transplanted tumor in mice. Flow cytometric analysis demonstrated that PTL inhibited the proliferation of Sarcoma 180 in a time- and dose-dependent manner through inhibiting the transition of G1/S and subsequently inducing G0/G1 cell cycle arrest. Thus, Pinellia ternata lectin displays a high potential for antitumor activity. PMID:23961344

  10. The three-dimensional structure of codakine and related marine C-type lectins.

    PubMed

    Gourdine, Jean-Philippe; Markiv, Anatoly; Smith-Ravin, Juliette

    2007-10-01

    Codakine is a new Ca(2+)-dependent mannose-binding C-type lectin (MBL) isolated from the gill tissue of the tropical clam, Codakia orbicularis. Bioinformatic analyses with the BLAST program have revealed similarities with marine lectins involved in immunity whose three-dimensional (3D) structures were unknown up until recently. In this article, we present bioinformatic analyses of marine lectins that are homologous to codakine, in particular lectins from the sea worm Laxus oneistus, named mermaid. These lectins are involved in the symbiotic association with sulphur-oxidizing bacteria which are closely related to the C. orbicularis gill symbiont. Using homology modelling, folding that is characteristic of C-type lectins was observed in all the marine Ca(2+)-dependent lectins studied, with conservation of random coiled structures of the carbohydrate recognition domain (CRD) and Ca(2+)-binding sites. Like codakine, the marine lectins analysed contain a signal peptide commonly found in secreted and transmembrane proteins. The majority of the predictive 3D models established from the lectins exhibit a common feature, namely the involvement in invertebrate and vertebrate immunity (dendritic cell receptor, macrophage receptor, etc.). These bioinformatic analyses and the literature data support the hypothesis that codakine, like the L. oneistus mermaids, is probably involved in the cellular mediation of symbiosis and defence against pathogenic microorganisms. PMID:17493832

  11. Purification and biological effects of Araucaria angustifolia (Araucariaceae) seed lectin

    SciTech Connect

    Santi-Gadelha, Tatiane; Almeida Gadelha, Carlos Alberto de; Aragao, Karoline Saboia; Gomes, Raphaela Cardoso; Freitas Pires, Alana de; Toyama, Marcos Hikari; Oliveira Toyama, Daniela de; Nunes de Alencar, Nylane Maria; Criddle, David Neil; Assreuy, Ana Maria Sampaio . E-mail: assreuy@uece.br; Cavada, Benildo Sousa . E-mail: bscavada@ufc.br

    2006-12-01

    This paper describes the purification and characterization of a new N-acetyl-D-glucosamine-specific lectin from Araucaria angustifolia (AaL) seeds (Araucariaceae) and its anti-inflammatory and antibacterial activities. AaL was purified using a combination of affinity chromatography on a chitin column and ion exchange chromatography on Sephacel-DEAE. The pure protein has 8.0 kDa (SDS-PAGE) and specifically agglutinates rabbit erythrocytes, effect that was independent of the presence of divalent cations and was inhibited after incubation with glucose and N-acetyl-D-glucosamine. AaL showed antibacterial activity against Gram-negative and Gram-positive strains, shown by scanning electron microscopy. AaL, intravenously injected into rats, showed anti-inflammatory effect, via carbohydrate site interaction, in the models of paw edema and peritonitis. This lectin can be used as a tool for studying bacterial infections and inflammatory processes.

  12. Disseminated zygomycosis associated with erythroleukaemia: confirmation by lectin stains.

    PubMed Central

    Benbow, E W; Delamore, I W; Stoddart, R W; Reid, H

    1985-01-01

    Zygomycosis is not often diagnosed in the United Kingdom, and so the possible importance of the findings in a patient with disseminated zygomycosis who had been treated with chemotherapy for erythroleukaemia was not appreciated until histological examination of specimens obtained at necropsy provided a presumptive diagnosis. No attempt had therefore been made to identify the organism by culture, and lectin binding methods were used to try to compensate for this. The characteristics of the hyphae on staining with lectins were similar to those previously shown in Rhizopus oryzae and were unlike those of a wide range of other hyphal fungi. Although definite speciation of the fungus was not achieved, these findings confirm that this was a case of zygomycosis and would seem to represent the first such reported confirmation in the absence of culture. Images PMID:2413080

  13. C-type lectins in immunity: recent developments

    PubMed Central

    Dambuza, Ivy M; Brown, Gordon D

    2015-01-01

    C-type lectin receptors (CLRs) comprise a large superfamily of proteins, which recognise a diverse range of ligands, and are defined by the presence of at least one C-type lectin-like domain (CTLD). Of particular interest are the single extracellular CTLD-containing receptors of the ‘Dectin-1’ and ‘Dectin-2’ clusters, which associate with signalling adaptors or possess integral intracellular signalling domains. These CLRs have traditionally been associated with the recognition of fungi, but recent discoveries have revealed diverse and unexpected functions. In this review, we describe their newly identified roles in anti-microbial host defence, homeostasis, autoimmunity, allergy and their functions in the recognition and response to dead and cancerous cells. PMID:25553393

  14. Binding of insecticidal lectin Colocasia esculenta tuber agglutinin (CEA) to midgut receptors of Bemisia tabaci and Lipaphis erysimi provides clues to its insecticidal potential.

    PubMed

    Roy, Amit; Gupta, Sumanti; Hess, Daniel; Das, Kali Pada; Das, Sampa

    2014-07-01

    The insecticidal potential of Galanthus nivalis agglutinin-related lectins against hemipterans has been experimentally proven. However, the basis behind the toxicity of these lectins against hemipterans remains elusive. The present study elucidates the molecular basis behind insecticidal efficacy of Colocasia esculenta tuber agglutinin (CEA) against Bemisia tabaci and Lipaphis erysimi. Confocal microscopic analyses highlighted the binding of 25 kDa stable homodimeric lectin to insect midgut. Ligand blots followed by LC MS/MS analyses identified binding partners of CEA as vacuolar ATP synthase and sarcoplasmic endoplasmic reticulum type Ca(2+) ATPase from B. tabaci, and ATP synthase, heat shock protein 70 and clathrin heavy chain assembly protein from L. erysimi. Internalization of CEA into hemolymph was confirmed by Western blotting. Glycoprotein nature of the receptors was identified through glycospecific staining. Deglycosylation assay indicated the interaction of CEA with its receptors to be probably glycan mediated. Surface plasmon resonance analysis revealed the interaction kinetics between ATP synthase of B. tabaci with CEA. Pathway prediction study based on Drosophila homologs suggested the interaction of CEA with insect receptors that probably led to disruption of cellular processes causing growth retardation and loss of fecundity of target insects. Thus, the present findings strengthen our current understanding of the entomotoxic potentiality of CEA, which will facilitate its future biotechnological applications. PMID:24753494

  15. Glycopolymer-Grafted Polymer Particles for Lectin Recognition.

    PubMed

    Kohri, Michinari; Taniguchi, Tatsuo; Kishikawa, Keiki

    2016-01-01

    Glycopolymers bearing carbohydrates have an advantage in protein recognition that is attributable to the multivalent effect (cluster effect) of side-chain carbohydrates. A variety of surface-modified polymer particles have been prepared concurrently with the development of new synthetic technology. Here we describe a synthetic method of glycopolymer-grafted polymer particles by surface-initiated living radical polymerization, i.e., atom-transfer radical polymerization (ATRP) and photoiniferter polymerization, for specific lectin recognition. PMID:26537470

  16. Modulatory Role of Surface Coating of Superparamagnetic Iron Oxide Nanoworms in Complement Opsonization and Leukocyte Uptake.

    PubMed

    Inturi, Swetha; Wang, Guankui; Chen, Fangfang; Banda, Nirmal K; Holers, V Michael; Wu, LinPing; Moghimi, Seyed Moein; Simberg, Dmitri

    2015-11-24

    Notwithstanding rapid advances of nanotechnology in diagnostic imaging and drug delivery, the engineered nanocarriers still exhibit substantial lack of hemocompatibility. Thus, when injected systemically, nanoparticles are avidly recognized by blood leukocytes and platelets, but the mechanisms of immune recognition are not well understood and strategies to mitigate these phenomena remain underexplored. Using superparamagnetic dextran iron oxide (SPIO) nanoworms (NWs) we demonstrate an efficient and predominantly complement-dependent uptake by mouse lymphocytes, neutrophils and monocytes from normal and tumor bearing mice in vitro. Following intravenous injection into wild type mice, blood leukocytes as well as platelets became magnetically labeled, while the labeling was decreased by 95% in complement C3-deficient mice. Using blood cells from healthy and cancer patient donors, we demonstrated that neutrophils, monocytes, lymphocytes and eosinophils took up SPIO NWs, and the uptake was prevented by EDTA (a general complement inhibitor) and by antiproperdin antibody (an inhibitor of the alternative pathway of the complement system). Cross-linking and hydrogelation of SPIO NWs surface by epichlorohydrin decreased C3 opsonization in mouse serum, and consequently reduced the uptake by mouse leukocytes by more than 70% in vivo. Remarkably, the cross-linked particles did not show a decrease in C3 opsonization in human serum, but showed a significant decrease (over 60%) of the uptake by human leukocytes. The residual uptake of cross-linked nanoparticles was completely blocked by EDTA. These findings demonstrate species differences in complement-mediated nanoparticle recognition and uptake by leukocytes, and further show that human hemocompatibility could be improved by inhibitors of complement alternative pathway and by nanoparticle surface coating. These results provide important insights into the mechanisms of hemocompatibility of nanomedicines. PMID:26488074

  17. Plasmon waveguide resonance for sensing glycan-lectin interactions.

    PubMed

    Alves, Isabel; Kurylo, Ievgen; Coffinier, Yannick; Siriwardena, Aloysius; Zaitsev, Vladimir; Harté, Etienne; Boukherroub, Rabah; Szunerits, Sabine

    2015-05-11

    Carbohydrate-modified interfaces have been shown to be valuable tools for the study of protein-glycan recognition events. Label-free approache such as plasmonic based techniques are particularly attractive. This paper describes a new analytical platform for the sensitive and selective screening of carbohydrate-lectin interactions using plasmon waveguide resonance. Planar optical waveguides (POW), consisting of glass prisms coated with silver (50 nm) and silica (460 nm) layers were derivatized with mannose or lactose moieties. The specific association of the resulting interface with selected lectins was assessed by following the changes in its plasmonic response. The immobilization strategy investigated in this work is based on the formation of a covalent bond between propargyl-functionalized glycans and surface-linked azide groups via a Cu(I) "click" chemistry. Optimization of the surface architecture through the introduction of an oligo(ethylene glycol) spacer between the plasmonic surface and the glycan ligands provided an interface which allowed screening of glycan-lectin interactions in a highly selective manner. The limit of detection (LOD) of this method for this particular application was found to be in the subnanomolar range (0.5 nM), showing it to constitute a promising analytical platform for future development and use in a pharmaceutical or biomedical setting. PMID:25911432

  18. Regional differences in lectin binding patterns of vestibular hair cells

    NASA Technical Reports Server (NTRS)

    Baird, Richard A.; Schuff, N. R.; Bancroft, J.

    1994-01-01

    Surface glycoconjugates of hair cells and supporting cells in the vestibular endorgans of the bullfrog were identified using biotinylated lectins with different carbohydrate specificities. Lectin binding in hair cells was consistent with the presence of glucose and mannose (CON A), galactose (RCA-I), N-acetylgalactosamine (VVA), but not fucose (UEA-I) residues. Hair cells in the bullfrog sacculus, unlike those in the utriculus and semicircular canals, did not stain for N-acetylglucosamine (WGA) or N-acetylgalactosamine (VVA). By contrast, WGA and, to a lesser extent, VVA, differentially stained utricular and semicircular canal hair cells, labeling hair cells located in peripheral, but not central, regions. In mammals, WGA uniformly labeled Type 1 hair cells while labeling, as in the bullfrog, Type 2 hair cells only in peripheral regions. These regional variations were retained after enzymatic digestion. We conclude that vestibular hair cells differ in their surface glycoconjugates and that differences in lectin binding patterns can be used to identify hair cell types and to infer the epithelial origin of isolated vestibular hair cells.

  19. Development of gastrointestinal surface. VIII. Lectin identification of carbohydrate differences

    SciTech Connect

    Pang, K.Y.; Bresson, J.L.; Walker, W.A.

    1987-05-01

    Binding of microvillus membranes (MVM) from newborn and adult rats by concanavalin A (Con A), Ulex europaeus (UEA I), Dolichos bifluorus (DBA), and Triticum vulgaris (WGA) was examined to determine the availability of carbohydrate-containing sites for these lectins on the intestinal surface during development. Consistent patterns of differences in the reaction of MVM with these lectins were found. Con A and UEA had much higher reactivities to MVM of adult than newborn rats. /sup 125/I-labeled-UEA gel overlay experiments revealed the abundance of UEA-binding sites in MVM of adult rat in contrast to the two binding sites in MVM of a newborn rat. DBA bound only to MVM of the adults, and very few binding sites were found in immature MVM. In contrast to these lectins, WGA binding was much higher in MVM of the newborns and decreased with maturation. Additional experiments on the age dependence of UEA and DBA reactivities revealed that the most striking changes occur in animals from 2 to 2 wk of age. In MVM from 2-wk-old rats, there were only 13.9% and < 0.2% of the adult binding capacities for UEA and DBA, respectively. By the time the animals were 4 wk old, the binding capacity for UEA had attained close to the level of the adults, whereas for DBA it reached 71.3% of the adult value. These results provide definite evidence of changes in the intestinal surface during perinatal development.

  20. Regional differences in lectin binding patterns of vestibular hair cells

    NASA Technical Reports Server (NTRS)

    Baird, R. A.; Schuff, N. R.; Bancroft, J.

    1993-01-01

    Surface glycoconjugates of hair cells and supporting cells in the vestibular endorgans of the bullfrog were identified using biotinylated lectins with different carbohydrate specificities. Lectin binding in hair cells was consistent with the presence of glucose and mannose (CON A), galactose (RCA-I), N-acetylglucosamine (WGA), N-acetylgalactosamine (VVA), but not fucose (UEA-I) residues. Hair cells in the bullfrog sacculus, unlike those in the utriculus and semicircular canals, did not strain for N-acetylglucosamine (WGA) or N-acetylgalactosamine (VVA). By contrast, WGA and, to a lesser extent, VVA, differentially stained utricular and semicircular canal hair cells, labeling hair cells located in peripheral, but not central, regions. In mammals, WGA uniformly labeled Type I hair cells while labeling, as in the bullfrog, Type II hair cells only in peripheral regions. These regional variations were retained after enzymatic digestion. We conclude that vestibular hair cells differ in their surface glycoconjugates and that differences in lectin binding patterns can be used to identify hair cell types and to infer the epithelial origin of isolated vestibular hair cells.

  1. The binucleate cell of okapi and giraffe placenta shows distinctive glycosylation compared with other ruminants: a lectin histochemical study.

    PubMed

    Jones, Carolyn J P; Wilsher, Sandra A; Wooding, F B P; Benirschke, K; Allen, W R

    2015-02-01

    The placenta of ruminants contains characteristic binucleate cells (BNC) with a highly conserved glycan structure which evolved early in Ruminant phylogenesis. Giraffe and Okapi placentae also contain these cells and it is not known whether they have a similar glycan array. We have used lectin histochemistry to examine the glycosylation of these cells in these species and compare them with bovine BNC which have a typical ruminant glycan composition. Two placentae, mid and near term, from Giraffe (Giraffa camelopardalis) and two term placenta of Okapi (Okapia johnstoni) were embedded in resin and stained with a panel of 23 lectins and compared with near-term bovine (Bos taurus) placenta. Significant differences were found in the glycans of Giraffe and Okapi BNC compared with those from the bovine, with little or no expression of terminal ?N-acetylgalactosamine bound by Dolichos biflorus and Vicia villosa agglutinins which instead bound to placental blood vessels. Higher levels of N-acetylglucosamine bound by Lycopersicon esculentum and Phytolacca americana agglutinins were also apparent. Some differences between Okapi and Giraffe were evident. Most N-linked glycans were similarly expressed in all three species as were fucosyl residues. Interplacentomal areas in Giraffe and Bovine showed differences from the placentomal cells though no intercotyledonary BNC were apparent in Okapi. In conclusion, Giraffidae BNC developed different glycan biosynthetic pathways following their split from the Bovidae with further differences evolving as Okapi and Giraffe diverged from each other, affecting both inter and placentomal BNC which may have different functions during development. PMID:25527317

  2. Structural Basis of Specific Recognition of Non-Reducing Terminal N-Acetylglucosamine by an Agrocybe aegerita Lectin

    PubMed Central

    Ren, Xiao-Ming; Li, De-Feng; Jiang, Shuai; Lan, Xian-Qing; Hu, Yonglin; Sun, Hui; Wang, Da-Cheng

    2015-01-01

    O-linked N-acetylglucosaminylation (O-GlcNAcylation) is a reversible post-translational modification that plays essential roles in many cellular pathways. Research in this field, however, is hampered by the lack of suitable probes to identify, accumulate, and purify the O-GlcNAcylated proteins. We have previously reported the identification of a lectin from the mushroom Agrocybe aegerita, i.e., Agrocybe aegerita lectin 2, or AAL2, that could bind terminal N-acetylglucosamine with higher affinities and specificity than other currently used probes. In this paper, we report the crystal structures of AAL2 and its complexes with GlcNAc and GlcNAc?1-3Gal?1-4GlcNAc and reveal the structural basis of GlcNAc recognition by AAL2 and residues essential for the binding of terminal N-acetylglucosamine. Study on AAL2 may enable us to design a protein probe that can be used to identify and purify O-GlcNAcylated proteins more efficiently. PMID:26114302

  3. Sialic acid-binding lectin (leczyme) induces caspase-dependent apoptosis-mediated mitochondrial perturbation in Jurkat cells.

    PubMed

    Tatsuta, Takeo; Hosono, Masahiro; Sugawara, Shigeki; Kariya, Yukiko; Ogawa, Yukiko; Hakomori, Senitiroh; Nitta, Kazuo

    2013-11-01

    Sialic acid binding lectin (SBL) isolated from Rana catesbeiana oocytes is a multifunctional protein which has lectin activity, ribonuclease activity and antitumor activity. However, the mechanism of antitumor effects of SBL is unclear to date and the validity for human leukemia cells has not been fully studied. We report here that SBL shows cytotoxicity for some human leukemia cell lines including multidrug-resistant (MDR) cells. The precise mechanisms of SBL-induced apoptotic signals were analyzed by combinational usage of specific caspase inhibitors and the mitochondrial membrane depolarization detector JC-1. It was demonstrated that SBL causes mitochondrial perturbation and the apoptotic signal is amplified by caspases and cell death is executed in a caspase-dependent manner. The efficacy of this combinational usage was shown for the first time, to distinguish the apoptotic pathway in detail. SBL selectively kills tumor cells, is able to exhibit cytotoxicity regardless of P-glycoprotein expression and has potential as an alternative to conventional DNA-damaging anticancer drugs. PMID:24008724

  4. Evidence for export of a muscle lectin from cytosol to extracellular matrix and for a novel secretory mechanism

    SciTech Connect

    Cooper, D.N.; Barondes, S.H. )

    1990-05-01

    A soluble lactose-binding lectin with subunit Mr of 14,500 is believed to function by interacting with extracellular glycoconjugates, because it has been detected extracellularly by immunohistochemistry. This localization has been questioned, however, since the lectin lacks a secretion signal sequence, which challenges the contention that it is secreted. We have demonstrated externalization of this lectin from C2 mouse muscle cells by both immunoprecipitation of metabolically labeled protein and immunohistochemical localization. We further show that externalization of the lectin is a developmentally regulated process that accompanies myoblast differentiation and that the lectin codistributes with laminin in myotube extracellular matrix. Immunohistochemical localization during intermediate stages of externalization suggests that the lectin becomes concentrated in evaginations of plasma membrane, which pinch off to form labile lectin-rich extracellular vesicles. This suggests a possible mechanism for lectin export from the cytosol to the extracellular matrix.

  5. High Mannose-Binding Antiviral Lectin PFL from Pseudomonas fluorescens Pf0-1 Promotes Cell Death of Gastric Cancer Cell MKN28 via Interaction with ?2-Integrin

    PubMed Central

    Sato, Yuichiro; Morimoto, Kinjiro; Kubo, Takanori; Yanagihara, Kazuyoshi; Seyama, Toshio

    2012-01-01

    Novel anti-HIV lectin family which shows a strict binding specificity for high mannose glycans has been found in lower organisms. The bacterial orthologue has been identified in the genome of Pseudomonas fluorescens Pf0-1 and the gene coding a putative lectin was cloned, expressed in Escherichia coli and purified by one step gel filtration. Glycan array screening of the recombinant lectin, termed PFL, has revealed that PFL preferentially recognizes high mannose glycans with ?1-3 Man that was highly exposed at the D2 position. In contrast, masking of this ?1-3 Man with ?1-2 Man dramatically impaired lectin-carbohydrate interactions. Reducing terminal disaccharide, GlcNAc-GlcNAc of high mannose glycans was also essential for PFL-binding. PFL showed a potent anti-influenza virus activity by inhibiting the virus entry into cells at doses of low nanomolar concentration. At micromolar concentration or higher, PFL showed a cytotoxicity accompanying loss of the cell adhesion against human gastric cancer MKN28 cells. The cell surface molecule to which PFL bound was co-precipitated with biotin-labeled PFL and identified as integrin ?2 by peptide mass fingerprinting using MALDI-TOF mass spectrometry. Intriguingly, upon treatment with exogenous PFL, integrin ?2 on the cell surface underwent rapid internalization to the cytoplasm and accumulated to perinuclear region, together with the bound PFL. The resulting loss of cell adherence would trigger a signaling pathway that induced anoikis-like cell death. These events were effectively inhibited by pretreatment of PFL with mannnan, indicating the involvement of high mannose glycans on PFL-induced cell death that was triggered by PFL-integrin ?2 interactions. PMID:23029318

  6. Phosphorylation Modification of Wheat Lectin VER2 Is Associated with Vernalization-Induced O-GlcNAc Signaling and Intracellular Motility

    PubMed Central

    Xing, Lijing; Li, Juan; Xu, Yunyuan; Xu, Zhihong; Chong, Kang

    2009-01-01

    Background O-linked ?-N-acetylglucosamine (O-GlcNAc) modification of proteins mediates stress response and cellular motility in animal cells. The plant lectin concanavalin A can increase nuclear O-GlcNAc levels and decrease cytoplasmic O-GlcNAc levels in T lymphocytes. However, the functions of O-GlcNAc signaling in plants, as well as the relation between plant lectins and O-GlcNAc in response to environmental stimuli are largely undefined. Methodology/Principal Findings We describe a jacalin-like lectin VER2 in wheat that shows N-acetylglucosamine and galactose specificity. Immunocytochemical localization showed VER2 expression induced predominantly at potential nuclear structures in shoot tips and young leaves and weakly in cytoplasm in response to vernalization. In contrast, under devernalization (continuous stimulation with a higher temperature after vernalization), VER2 signals appeared predominantly in cytoplasm. 2-D electrophoresis, together with western blot analysis, showed phosphorylation modification of VER2 under vernalization. Immunoblot assay with O-GlcNAc-specific antibody revealed that vernalization increased O-GlcNAc modification of proteins at the global level. An O-GlcNAc-modified protein co-immunoprecipitated with VER2 in vernalized wheat plants but not in devernalized materials. The dynamic of VER2 was observed in transgenic Arabidopsis overexpressing the VER2-GFP fusion protein. Overexpressed VER2 accelerated nuclear migration. Immunogold labeling and indirect immunofluoresence colocalization assay indicated that VER2-GFP was targeted to the secretory pathway. Conclusions/Significance O-GlcNAc signaling is involved in the vernalization response in wheat, and phosphorylation is necessary for the lectin VER2 involving O-GlcNAc signaling during vernalization. Our findings open the way to studies of O-GlcNAc protein modification in response to environmental signals in plants. PMID:19287503

  7. Interaction of linear manno-oligosaccharides with three mannose-specific bulb lectins. Comparison with mannose/glucose-binding lectins.

    PubMed

    Kaku, H; Goldstein, I J

    1992-05-22

    Three new mannose-binding lectins, isolated from daffodil (NPA), amaryllis (HHA), and snowdrop (GNA) bulbs, are capable of precipitating with a linear mannopentaose (Man alpha 1-3Man alpha 1-3Man alpha 1-3Man alpha 1-2Man). NPA and HHA reacted strongly with the mannopentaose whereas GNA gave a precipitate only at concentrations greater than 500 microM. A phosphate group at C-6 of the nonreducing terminal mannosyl group prevented precipitation in all three cases. The reduced (NaBH4) mannopentaose, Man4Man-ol, did not precipitate with GNA or NPA, but was active with HHA. This activity was lost when Man4Man-ol was converted (NaIO4 then NaBH4; mild acid hydrolysis of the reduced product) into trisaccharide derivatives. With alpha-D-Manp-OMe the three lectins gave UV difference spectra having large positive peaks at 292-293 and 283-284 nm, and a small positive peak at 275 nm, characteristic of tryptophanyl and tyrosyl residues. The association constants for the interaction with alpha-D-Manp-OMe were very low (NPA, 86; HHA, 66; and GNA, 41 M-1), but the lectins bound methyl (1----3)-alpha-mannobioside with increased affinity (K for NPA 540, for HHA 2400, and for GNA 200 M-1). The bulb lectins lack binding sites for hydrophobic ligands, as judged by their failure to interact with the fluorescent probes 8-anilino-1-napthalenesulfonic acid (ANS) and 6-p-toluidino-2-naphthalenesulfonic acid (TNS). PMID:1394290

  8. Complementing the Sugar Code: Role of GAGs and Sialic Acid in Complement Regulation

    PubMed Central

    Langford-Smith, Alex; Day, Anthony J.; Bishop, Paul N.; Clark, Simon J.

    2015-01-01

    Sugar molecules play a vital role on both microbial and mammalian cells, where they are involved in cellular communication, govern microbial virulence, and modulate host immunity and inflammatory responses. The complement cascade, as part of a host’s innate immune system, is a potent weapon against invading bacteria but has to be tightly regulated to prevent inappropriate attack and damage to host tissues. A number of complement regulators, such as factor H and properdin, interact with sugar molecules, such as glycosaminoglycans (GAGs) and sialic acid, on host and pathogen membranes and direct the appropriate complement response by either promoting the binding of complement activators or inhibitors. The binding of these complement regulators to sugar molecules can vary from location to location, due to their different specificities and because distinct structural and functional subpopulations of sugars are found in different human organs, such as the brain, kidney, and eye. This review will cover recent studies that have provided important new insights into the role of GAGs and sialic acid in complement regulation and how sugar recognition may be compromised in disease. PMID:25699044

  9. Complement and phagocytes - A complicated interaction.

    PubMed

    Roos, Dirk

    2015-11-01

    Mohamed Daha and I share a common interest in innate immunity. Working in institutes only 25 miles away from each other, that meant ample opportunity and relevance for collaboration. And so we did. Moreover, we have both been members of boards and councils of Dutch national organizations, and we have also become good friends. In this short recollection, I look back on 40 years of common activities in complement research and friendship. PMID:26597203

  10. Populism and technocracy: opposites or complements?

    E-print Network

    Bickerton, Christopher; Accetti, Carlo Invernizzi

    2015-04-07

    Review of International Social and Political Philosophy.pdf.txt Content-Type text/plain; charset=UTF-8 1 POPULISM AND TECHNOCRACY: OPPOSITES OR COMPLEMENTS? Christopher Bickerton (University of Cambridge) Carlo Invernizzi... of the ongoing European crisis, Mark Leonard described populism and technocracy as “two contradictory and mutually reinforcing forces”. “The EU”, he wrote, “has been the ultimate technocratic project … But, as the EU matured as a political project, its very...

  11. Complement System in Pathogenesis of AMD: Dual Player in Degeneration and Protection of Retinal Tissue

    PubMed Central

    Kawa, Milosz P.; Machalinska, Anna; Roginska, Dorota; Machalinski, Boguslaw

    2014-01-01

    Age-related macular degeneration (AMD) is the most common cause of blindness among the elderly, especially in Western countries. Although the prevalence, risk factors, and clinical course of the disease are well described, its pathogenesis is not entirely elucidated. AMD is associated with a variety of biochemical abnormalities, including complement components deposition in the retinal pigment epithelium-Bruch's membrane-choriocapillaris complex. Although the complement system (CS) is increasingly recognized as mediating important roles in retinal biology, its particular role in AMD pathogenesis has not been precisely defined. Unrestricted activation of the CS following injury may directly damage retinal tissue and recruit immune cells to the vicinity of active complement cascades, therefore detrimentally causing bystander damage to surrounding cells and tissues. On the other hand, recent evidence supports the notion that an active complement pathway is a necessity for the normal maintenance of the neurosensory retina. In this scenario, complement activation appears to have beneficial effect as it promotes cell survival and tissue remodeling by facilitating the rapid removal of dying cells and resulting cellular debris, thus demonstrating anti-inflammatory and neuroprotective activities. In this review, we discuss both the beneficial and detrimental roles of CS in degenerative retina, focusing on the diverse aspects of CS functions that may promote or inhibit macular disease. PMID:25276841

  12. A possible role for complement in the pathogenesis of chronic chagasic cardiomyopathy.

    PubMed

    Aiello, Vera Demarchi; Reis, Márcia Martins; Benvenuti, Luiz Alberto; Higuchi, Maria de Lourdes; Ramires, José Antonio Franchini; Halperin, José A

    2002-06-01

    The membrane attack complex (MAC) of complement participates in several inflammatory and proliferative processes by releasing pro-inflammatory cytokines and growth factors from target cells. Chronic Chagasic cardiomyopathy (CCH) is a parasitic dilated cardiopathy, characterized by severe fibrosis and inflammation, which differs from idiopathic dilated cardiomyopathy (DCM). Trypanosoma cruzi, the pathogenic organism of CCH, is a strong complement activator and can also induce alternative pathway activation by mammalian cells. This study explored whether the myocardium in CCH patients has increased MAC deposition, an expression of complement activation, compared to DCM patients. MAC was semi-quantified in endomyocardial human samples (29 CCH subjects, 18 DCM subjects, and four controls) by immunohistochemistry. MAC was present in the sarcolemma of 38% of CCH, 5.5% of DCM (p<0.02), and 0% of controls, and in interstitial inflammatory cells of CCH. No difference was observed in the expression of the complement regulatory protein CD59, indicating that increased MAC deposition is likely to be the result of complement activation rather than decreased protection. It is proposed that the increased MAC deposition found in CCH, but not in DCM or controls, may help to explain the diffuse myocardial fibrosis and inflammation characteristic of the disease. PMID:12015747

  13. CTRP6 is an endogenous complement regulator that can effectively treat induced arthritis

    PubMed Central

    Murayama, Masanori A.; Kakuta, Shigeru; Inoue, Asuka; Umeda, Naoto; Yonezawa, Tomo; Maruhashi, Takumi; Tateishi, Koichiro; Ishigame, Harumichi; Yabe, Rikio; Ikeda, Satoshi; Seno, Akimasa; Chi, Hsi-Hua; Hashiguchi, Yuriko; Kurata, Riho; Tada, Takuya; Kubo, Sachiko; Sato, Nozomi; Liu, Yang; Hattori, Masahira; Saijo, Shinobu; Matsushita, Misao; Fujita, Teizo; Sumida, Takayuki; Iwakura, Yoichiro

    2015-01-01

    The complement system is important for the host defence against infection as well as for the development of inflammatory diseases. Here we show that C1q/TNF-related protein 6 (CTRP6; gene symbol C1qtnf6) expression is elevated in mouse rheumatoid arthritis (RA) models. C1qtnf6?/? mice are highly susceptible to induced arthritis due to enhanced complement activation, whereas C1qtnf6-transgenic mice are refractory. The Arthus reaction and the development of experimental autoimmune encephalomyelitis are also enhanced in C1qtnf6?/? mice and C1qtnf6?/? embryos are semi-lethal. We find that CTRP6 specifically suppresses the alternative pathway of the complement system by competing with factor B for C3(H2O) binding. Furthermore, treatment of arthritis-induced mice with intra-articular injection of recombinant human CTRP6 cures the arthritis. CTRP6 is expressed in human synoviocytes, and CTRP6 levels are increased in RA patients. These results indicate that CTRP6 is an endogenous complement regulator and could be used for the treatment of complement-mediated diseases. PMID:26404464

  14. Complement Split Products in Amniotic Fluid in Pregnancies Subsequently Developing Early-Onset Preeclampsia

    PubMed Central

    Banadakoppa, Manu; Vidaeff, Alex C.; Yallampalli, Uma; Ramin, Susan M.; Belfort, Michael A.; Yallampalli, Chandra

    2015-01-01

    Objective. To determine the second-trimester amniotic fluid concentrations of complement split products in pregnancies subsequently affected by early-onset preeclampsia. Study Design. Cohort of 731 women with singleton pregnancies undergoing second-trimester genetic amniocentesis followed up to delivery and analyzed as a nested case-control study. Cases of preeclampsia developing before 34 weeks' gestation (n = 15) were compared with 47 uncomplicated term controls. Amniotic fluid collected at amniocentesis was tested for complement split products Bb, C4a, C3a, and C5a. Results. Women who developed early-onset preeclampsia as compared with the term pregnant controls had significantly higher (P = 0.04) median amniotic fluid C3a levels (318.7?ng/mL versus 254.5?ng/mL). Median amniotic fluid Bb levels were also significantly higher (P = 0.03) in preeclamptic women than in normal pregnant women (1127?ng/mL versus 749?ng/mL). Median levels of C4a and C5a were not significantly different between the groups. Conclusion. Our data suggest that complement activation in early pregnancy is associated with early-onset preeclampsia. We believe this to be the first prospective study to link complement activation in amniotic fluid in early pregnancy and later development of preeclampsia. Our findings provide evidence that immune dysregulation may precede the clinical manifestations of preeclampsia and that the alternative complement pathway is principally involved. PMID:26556948

  15. Purification and Characterization of a Mucin Specific Mycelial Lectin from Aspergillus gorakhpurensis: Application for Mitogenic and Antimicrobial Activity

    PubMed Central

    Singh, Ram Sarup; Kaur, Hemant Preet; Singh, Jatinder

    2014-01-01

    Background Lectins are carbohydrate binding proteins or glycoproteins that bind reversibly to specific carbohydrates present on the apposing cells, which are responsible for their ability to agglutinate red blood cells, lymphocytes, fibroblasts, etc. Interest in lectins has been intensified due to their carbohydrate specificity as they can be valuable reagents for the investigation of cell surface sugars, purification and characterization of glycoproteins. The present study reports the purification, characterization and evaluation of mitogenic and antimicrobial potential of a mycelial lectin from Aspergillus gorakhpurensis. Methods Affinity chromatography on mucin-sepharose column was carried out for purification of Aspergillus gorakhpurensis lectin. The lectin was characterized for physico-chemical parameters. Mitogenic potential of the lectin was evaluated against splenocytes of Swiss albino mice by MTT assay. Antimicrobial activity of the purified lectin has also been evaluated by disc diffusion assay. Results Single-step affinity purification resulted in 18.6-fold purification of the mycelial lectin. The molecular mass of the lectin was found to be 70 kDa and it was composed of two subunits of 34.8 kDa as determined by gel filtration chromatography, SDS-PAGE and MALDI-TOF analysis. pH optima of the lectin was found to be 6.5–9.5, while optimum temperature for lectin activity was 20–30°C. Lectin was stable within a pH range of 7.0–10.5 and showed fair thermostability. EDTA did not affect lectin activity whereas it was found susceptible to the denaturants tested. MTT assay revealed strong mitogenic potential of A. gorakhpurensis lectin at a concentration upto 150 µg/mL. Antimicrobial activity assay showed its potent antibacterial activity against Bacillus cereus, Staphylococcous aureus and Escherichia coli and marginal antifungal activity against Saccharomyces cerevisiae. Conclusion This is the first report on the mitogenic and antimicrobial potential of Aspergillus gorakhpurensis lectin. The results will provide useful guidelines for further research in clinical applications of this lectin. PMID:25286160

  16. [The mechanisms of a new plant lectin FRIL from dolichos lablab that preserves quiescent hematopoietic stem cells in suspension culture].

    PubMed

    Xie, Chao; Pei, Xue-Tao

    2003-04-01

    Lectins, proteins that bind sugar moieties of glycolipids and glycoproteins, occur in all organisms and are especially abundant in many plants. Plant lectins probably have multiple roles related to their ability to act as recognition molecules. Here we present a review on the biological characterization of a new plant lectin in red kidney bean named Flt3 receptor-interacting lectin(FRIL), and focus on the mechanisms that FRIL can preserve quiescent hematopoietic stem cells in suspension culture. PMID:12889144

  17. Polyamine pathway contributes to the pathogenesis of Parkinson disease

    E-print Network

    Lewandowski, Nicole M.

    The full complement of molecular pathways contributing to the pathogenesis of Parkinson disease (PD) remains unknown. Here we address this issue by taking a broad approach, beginning by using functional MRI to identify ...

  18. SPERM-LECTIN AGGLUTINATION COMBINED WITH SWIM-UP LEADS TO AN EFFICIENT SELECTION OF HIGHLY MOTILE, VIABLE AND HETEROGENEOUSRAM

    E-print Network

    Zaragoza, Universidad de

    ELSEVIER SPERM-LECTIN AGGLUTINATION COMBINED WITH SWIM-UP LEADS TO AN EFFICIENT SELECTION OF HIGHLY induced by the lectin binding. The objective of this study was to combine sperm-lectin agglutination with a dextran/swim°up procedure for developing a new selection technique for ram spermatozoa. To study sperm

  19. Microfibrillar associated protein 4 mfap4 genes in catfish play a novel role in innate immune responses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The lectin pathway of the complement system is characterized by two groups of soluble pattern recognition molecules, mannose-binding lectins (MBLs) and ficolins. These molecules recognize and bind carbohydrates in pathogens and activate complement leading to opsonization, leukocyte activation, and d...

  20. Mechanism of entomotoxicity of the plant lectin from Hippeastrum hybrid (Amaryllis) in Spodoptera littoralis larvae.

    PubMed

    Caccia, Silvia; Van Damme, Els J M; De Vos, Winnok H; Smagghe, Guy

    2012-09-01

    Plant lectins have received a lot of attention because of their insecticidal properties. When orally administered in artificial diet or in transgenic plants, lectins provoke a wide range of detrimental effects, including alteration of the digestive enzyme machinery, fecundity drop, reduced feeding, changes in oviposition behavior, growth and development inhibition and mortality. Although many studies reported the entomotoxicity of lectins, only a few of them investigated the mode of action by which lectins exert toxicity. In the present paper we have studied for the first time the insecticidal potential of the plant lectin from Hippeastrum hybrid (Amaryllis) (HHA) bulbs against the larvae of the cotton leafworm (Spodoptera littoralis). Bioassays on neonate larvae showed that this mannose-specific lectin affected larval growth, causing a development retardation and larval weight decrease. Using primary cell cultures from S. littoralis midguts and confocal microscopy we have elucidated FITC-HHA binding and internalization mechanisms. We found that HHA did not exert a toxic effect on S. littoralis midgut cells, but HHA interaction with the brush border of midgut cells interfered with normal nutrient absorption in the S. littoralis midgut, thereby affecting normal larval growth in vivo. This study thus confirms the potential of mannose-specific lectins as pest control agents and sheds light on the mechanism underlying lectin entomotoxicity. PMID:22677323

  1. C-type lectins do not act as functional receptors for filovirus entry into cells

    SciTech Connect

    Matsuno, Keita; Nakayama, Eri; Noyori, Osamu; Marzi, Andrea; Ebihara, Hideki; Irimura, Tatsuro; Feldmann, Heinz; Takada, Ayato

    2010-12-03

    Research highlights: {yields} Filovirus glycoprotein (GP) having a deficient receptor binding region were generated. {yields} Mutant GPs mediated virus entry less efficiently than wild-type GP. {yields} Mutant GPs bound to C-type lectins but not mediated entire steps of cellular entry. {yields} C-type lectins do not independently mediate filovirus entry into cells. {yields} Other molecule(s) are required for C-type lectin-mediated entry of filoviruses. -- Abstract: Cellular C-type lectins have been reported to facilitate filovirus infection by binding to glycans on filovirus glycoprotein (GP). However, it is not clearly known whether interaction between C-type lectins and GP mediates all the steps of virus entry (i.e., attachment, internalization, and membrane fusion). In this study, we generated vesicular stomatitis viruses pseudotyped with mutant GPs that have impaired structures of the putative receptor binding regions and thus reduced ability to infect the monkey kidney cells that are routinely used for virus propagation. We found that infectivities of viruses with the mutant GPs dropped in C-type lectin-expressing cells, parallel with those in the monkey kidney cells, whereas binding activities of these GPs to the C-type lectins were not correlated with the reduced infectivities. These results suggest that C-type lectin-mediated entry of filoviruses requires other cellular molecule(s) that may be involved in virion internalization or membrane fusion.

  2. Inhibition of protein synthesis in vitro by a lectin from Momordica charantia and by other haemagglutinins.

    PubMed Central

    Barbieri, L; Lorenzoni, E; Stirpe, F

    1979-01-01

    Protein synthesis by a rabbit reticulocyte lysate is inhibited by the haemagglutinating lectins from Momordica charantia and Crotalaria juncea seeds and from the roe of Rutilus rutilus, and by a commercial preparation of the mitogenic lectin from Phytolacca americana. The haemagglutinins from the seeds of Ricinus communis and of Vicia cracca acquired inhibitory activity after their reduction with 2-mercaptoethanol. PMID:508306

  3. Purification and Characterization of a Lectin from Phaseolus vulgaris cv. (Anasazi Beans)

    PubMed Central

    Sharma, Arishya; Ng, Tzi Bun; Wong, Jack Ho; Lin, Peng

    2009-01-01

    A lectin has been isolated from seeds of the Phaseolus vulgaris cv. “Anasazi beans” using a procedure that involved affinity chromatography on Affi-gel blue gel, fast protein liquid chromatography (FPLC)-ion exchange chromatography on Mono S, and FPLC-gel filtration on Superdex 200. The lectin was comprised of two 30-kDa subunits with substantial N-terminal sequence similarity to other Phaseolus lectins. The hemagglutinating activity of the lectin was stable within the pH range of 1–14 and the temperature range of 0–80°C. The lectin potently suppressed proliferation of MCF-7 (breast cancer) cells with an IC50 of 1.3 ?M, and inhibited the activity of HIV-1 reverse transcriptase with an IC50 of 7.6 ?M. The lectin evoked a mitogenic response from murine splenocytes as evidenced by an increase in [3H-methyl]-thymidine incorporation. The lectin had no antifungal activity. It did not stimulate nitric oxide production by murine peritoneal macrophages. Chemical modification results indicated that tryptophan was crucial for the hemagglutinating activity of the lectin. PMID:19343172

  4. Evanescent-field fluorescence-assisted lectin microarray: a new strategy for glycan profiling

    E-print Network

    Cai, Long

    Evanescent-field fluorescence-assisted lectin microarray: a new strategy for glycan profiling no versatile method for glycan profiling. Here we describe a new microarray procedure based on an evanescent by frontal affinity chromatography, another profiling method. Thus, the developed lectin microarray should

  5. Structural Analysis of the Evolutionary Origins of Influenza Virus Hemagglutinin and Other Viral Lectins

    E-print Network

    Li, Fang

    , crystal structures have been determined for the fol- lowing viral lectins: rotavirus VP4 (2), adenovirus. Among them, rotavirus VP4, adenovirus GD, and coro- navirus spike NTD have been shown to share the same). All of the viral lectins also contain a -sandwich core. Among them, the -sandwich cores of rotavirus

  6. Lectins Associated With the Feeding Organs of the Oyster Crassostrea virginica Can Mediate Particle

    E-print Network

    Allam, Bassem

    Lectins Associated With the Feeding Organs of the Oyster Crassostrea virginica Can Mediate Particle, the Eastern oyster, our investigations demonstrated that lectins from oyster mucus can specifically bind incubated with mucus before being fed to oysters. Results showed that pre-treating these microalgae

  7. Advances and challenges in the management of complement-mediated thrombotic microangiopathies

    PubMed Central

    van de Kar, Nicole C. A. J.

    2015-01-01

    Complement activation plays a major role in several renal pathophysiological conditions. The three pathways of complement lead to C3 activation, followed by the formation of the anaphylatoxin C5a and the terminal membrane attack complex (MAC) in blood and at complement activating surfaces, lead to a cascade of events responsible for inflammation and for the induction of cell lysis. In case of ongoing uncontrolled complement activation, endothelial cells activation takes place, leading to events in which at the end thrombotic microangiopathy can occur. Atypical haemolytic uremic syndrome (aHUS) is a thrombotic microangiopathy characterized by excessive complement activation on the surface of the microcirculation. It is a severe, rare disease which leads to end-stage renal failure (ESRF) and/or to death in more than 50% of patients without treatment. In the first decade of the second millennium, huge progress in understanding the aetiology of this disease was made, which paved the way to better treatment. First, protocols of plasma therapy for treatment, prevention of relapses and for renal transplantation in those patients were set up. Secondly, in some severe cases, combined kidney and liver transplantation was reported. Finally, at the end of this decade, the era of complement inhibitors, as anti-C5 monoclonal antibody (anti-C5 mAb) began. The past five years have seen growing evidence of the favourable effect of anti-C5 mAb in aHUS which has made this drug the first-line treatment in this disease. The possible complication of meningococcal infection needs appropriate vaccination before its use. Unfortunately, the worldwide use of anti-C5 mAb is limited by its very high price. In the future, extension of indications for anti-C5 mAb use, the elaboration of generics and of mAbs directed towards other complement factors of the terminal pathway of the complement system might succeed in reducing the cost of this new valuable therapeutic approach and render it available worldwide for patients from all social classes. PMID:26288712

  8. Development of a C3c-based ELISA method for the determination of anti-complementary potency of Bupleurum polysaccharides

    PubMed Central

    Wu, Mulu; Li, Hong; Zhang, Yunyi; Chen, Daofeng

    2015-01-01

    Traditionally, determination of inhibitory potency of complement inhibitors is performed by the hemolytic assay. However, this assay is not applicable to the lectin pathway, thus impeding the understanding of complement inhibitors against the overall function of the complement system. The main objective of our study was to develop a specific enzyme-linked immunosorbent assay (ELISA) as an alternative method to assess the anti-complement activity, particularly against the lectin pathway. By using respective coating substrates against different activation pathways, followed by capturing the stable C3c fragments, our ELISA method can be used to screen complement inhibitors against the classical pathway and the lectin pathway. The inhibitory effect of suramin on the classical pathway, as measured by our hemolytic assay is consistent with previous reports. Further assessment of suramin and Bupleurum polysaccharides against the lectin pathway showed a good reproducibility of the method. Comparison of the lectin pathway IC50 between Bupleurum smithii var. parvifolium polysaccharides (1.055 mg/mL) and Bupleurum chinense polysaccharides (0.98 mg/mL) showed that, similar to the classical and alterative pathway, these two Bupleurum polysaccharides had comparable anti-complementary properties against the lectin pathway. The results demonstrate that the described ELISA assay can compensate for the shortcomings of the hemolytic assay in lectin pathway. PMID:26579461

  9. Naturally occurring anti-band-3 antibodies and complement together mediate phagocytosis of oxidatively stressed human erythrocytes

    SciTech Connect

    Lutz, H.U.; Bussolino, F.; Flepp, R.; Fasler, S.; Stammler, P.; Kazatchkine, M.D.; Arese, P.

    1987-11-01

    Treatment of erythrocytes with the thiol-specific oxidant azodicarboxylic acid bis(dimethylamide) (diamide) enhances their phagocytosis by adherent monocytes. Phagocytosis of diamide-treated erythrocytes required that the cells were opsonized with whole serum, since complement inactivation abolished phagocytosis. Opsonization with whole serum containing 20-100 times the physiological concentration of naturally occurring anti-band-3- antibodies enhanced phagocytosis of diamide-treated erythrocytes. High inputs of anti-band-3 also restored phagocytosis of erythrocytes that had been incubated with complement-inactivated serum. Elevated concentrations of anti-spectrin antibodies were ineffective in whole and complement-inactivated serum. Specific recognition of diamide-treated erythrocytes by anti-band-3 antibodies may be due to generation of anti-band-3 reactive protein oligomers on intact diamide-treated erythrocytes. Generation of such oligomers was dose-dependent with respect to diamide. Bound anti-band-3 alone was not sufficient to mediate phagocytosis. It resulted in deposition of complement component C3b on the cells through activation of the alternative complement pathway in amounts exceeding that of bound antibodies by two orders of magnitude. Thus, anti-band-3 and complement together mediate phagocytosis of oxidatively stressed erythrocytes, which simulate senescent erythrocytes with respect to bound antibody and complement.

  10. Polyphemin: a teichoic acid-binding lectin from the horseshoe crab, Limulus Polyphemus.

    PubMed

    Brandin, E R; Pistole, T G

    1983-06-15

    A Staphylococcus aureus-agglutinating lectin, capable of binding to N-acetyl-D-glucosamine, was isolated from the serum of Limulus polyphemus. The monosaccharide alone was incapable of inhibiting bacterial agglutination by this lectin. Quantitative precipitation studies with purified cell wall-derived teichoic acids, either devoid of or containing N-acetyl-D-glucosamine, confirmed the carbohydrate-binding specificity of the lectin and suggested that secondary, non-specific interactions contribute to binding biomolecules containing this sugar. The agglutination pattern with various S. aureus strains having N-acetyl-D-glucosamine-associated teichoic acid, teichoic acid without this sugar, and no teichoic acid indicated that this cell wall component is not the sole binding site for the lectin on intact S. aureus cells. Affinity gel chromatography, using N-acetyl-D-glucosamine-associated teichoic acid as the specific absorbent, has been used to isolate this lectin from Limulus serum. PMID:6870875

  11. Strain characterization and grouping of Campylobacter jejuni and Campylobacter coli by interaction with lectins.

    PubMed Central

    Wong, K H; Skelton, S K; Feeley, J C

    1986-01-01

    Strains of Campylobacter jejuni and Campylobacter coli were characterized and grouped by their distinct reaction patterns with lectins. Heating of the Campylobacter cultures to 100 degrees C and holding for 30 to 60 min greatly enhanced their reactivity with lectins and permitted the grouping of all but 3 of 155 cultures tested in this study without interference of autoagglutination and other nonspecific activities. The lectin reaction patterns of the heated cultures were stable and reproducible. They were strain specific and independent of the heat-stable antigenic types. The lectin-reactive sites of C. jejuni and C. coli may be useful as additional markers for strain characterization. Based on these observations, a simple slide agglutination procedure is described for differentiating strains of C. jejuni and C. coli by their interaction with a selected group of commercially available lectins. PMID:3754264

  12. Purification and characterization of a galactose-specific lectin with mitogenic activity from pinto beans.

    PubMed

    Wong, Jack H; Wong, Clarence C T; Ng, T B

    2006-05-01

    A galactose-specific dimeric lectin from pinto beans was purified using a procedure that involved affinity chromatography on Affi-gel blue gel, anion exchange chromatography on Q-Sepharose, fast protein liquid chromatography (FPLC)-ion exchange chromatography on Mono S, and FPLC-gel filtration on Superdex 200. The molecular mass of this homodimeric lectin was 62 kDa and that of each of its subunits was 31 kDa. The hemagglutinating activity of pinto bean lectin was stable within the pH range of 3-12 and the temperature range of 0-70 degrees C. By using the [3H-methyl]-thymidine incorporation assay, it was shown that the lectin had the ability to evoke a mitogenic response from murine splenocytes but it did not inhibit proliferation of L1210 leukemia cells. The pinto bean lectin inhibited HIV-1 reverse transcriptase with an IC50 of 3 microM. PMID:16600511

  13. Insecticidal activity of plant lectins and potential application in crop protection.

    PubMed

    Macedo, Maria Lígia R; Oliveira, Caio F R; Oliveira, Carolina T

    2015-01-01

    Lectins constitute a complex group of proteins found in different organisms. These proteins constitute an important field for research, as their structural diversity and affinity for several carbohydrates makes them suitable for numerous biological applications. This review addresses the classification and insecticidal activities of plant lectins, providing an overview of the applicability of these proteins in crop protection. The likely target sites in insect tissues, the mode of action of these proteins, as well as the use of lectins as biotechnological tools for pest control are also described. The use of initial bioassays employing artificial diets has led to the most recent advances in this field, such as plant breeding and the construction of fusion proteins, using lectins for targeting the delivery of toxins and to potentiate expected insecticide effects. Based on the data presented, we emphasize the contribution that plant lectins may make as tools for the development of integrated insect pest control strategies. PMID:25633332

  14. Correlation of Interleukin-6 levels and lectins during Schistosoma haematobium infection.

    PubMed

    Antony, Justin S; Ojurongbe, Olusola; Meyer, Christian G; Thangaraj, Kumarasamy; Mishra, Anshuman; Kremsner, Peter G; Velavan, Thirumalaisamy P

    2015-12-01

    Urogenital schistosomiasis caused by Schistosoma haematobium induces a Th2 immune response, including expression of Interleukin-6. IL-6 confers protection from experimental Schistosoma-induced pulmonary hypertension and modulates production of mannose-binding lectin (MBL) and other lectins. We studied IL-6 levels in schistosomiasis and its effect on lectins production. Elevated IL-6 levels occurred in cases, compared to controls. IL-6 correlated with the lectins MBL, ficolin-2 and Collectin Kidney-1 (CL-K1) in cases, but correlated inversely in controls. The study shows that IL-6 levels are elevated in individuals infected with urogenital schistosomiasis. IL-6 was also found to be correlated with the production of lectins in S. haematobium infection. A similar correlation between IL-6 and MBL was observed during visceral leishmaniasis. PMID:25982844

  15. Estimating farm machinery complements based on cropmix and farm size 

    E-print Network

    Barrera, Anna Marie

    1993-01-01

    Machinery complement information is used in farm simulation models such as the FLIPSIM model when studying of the impacts of agricultural policies on representative farms. Since acquiring machinery complement data for FLIPSIM simulations is a...

  16. Complementing Logic Program Semantics Roberto Giacobazzi? Francesco Ranzato??

    E-print Network

    Giacobazzi, Roberto

    Complementing Logic Program Semantics Roberto Giacobazzi? Francesco derive denotational semantics by composition and decomposition. Reduced product allows to perform the logical conjunction of semantics, while complementation characterizes what is left from a semanti

  17. ON COMPLEMENTED VERSIONS OF JAMES'S DISTORTION WILLIAM B. JOHNSON

    E-print Network

    Johnson, William B.

    ON COMPLEMENTED VERSIONS OF JAMES'S DISTORTION THEOREMS WILLIAM B. JOHNSON AND NARCISSE versions of James's distortion theorems have negative answers. 1. Introduction The James's distortion (respectively, c0). In [5], complemented versions of James's distortion theorems were considered

  18. Complement in immune and inflammatory disorders: pathophysiological mechanisms

    PubMed Central

    Ricklin, Daniel; Lambris, John D.

    2013-01-01

    While acute or chronic inflammation is a common component of many clinical disorders, the underlying processes can be highly distinct. In recent years, the complement system has been associated with a growing number of immunological and inflammatory conditions that include degenerative diseases, cancer and transplant rejection. It becomes evident that excessive activation or insufficient control of complement activation on host cells can cause an immune imbalance that may fuel a vicious cycle between complement, inflammatory cells and tissue damage that exacerbates clinical complications. Although the exact involvement of complement needs to be carefully investigated for each disease, therapeutic modulation of complement activity emerges as attractive target for upstream inhibition of inflammatory processes. This review provides an update about the functional and collaborative capabilities of complement, highlights major disease areas with known complement contribution, and indicates the potential for complement as focal point in immunomodulatory strategies for treating inflammatory diseases. PMID:23564577

  19. Selective binding of lectins to normal and neoplastic urothelium in rat and mouse bladder carcinogenesis models.

    PubMed

    Zupan?i?, Daša; Kreft, Mateja Erdani; Romih, Rok

    2014-01-01

    Bladder cancer adjuvant intravesical therapy could be optimized by more selective targeting of neoplastic tissue via specific binding of lectins to plasma membrane carbohydrates. Our aim was to establish rat and mouse models of bladder carcinogenesis to investigate in vivo and ex vivo binding of selected lectins to the luminal surface of normal and neoplastic urothelium. Male rats and mice were treated with 0.05 % N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) in drinking water and used for ex vivo and in vivo lectin binding experiments. Urinary bladder samples were also used for paraffin embedding, scanning electron microscopy and immunofluorescence labelling of uroplakins. During carcinogenesis, the structure of the urinary bladder luminal surface changed from microridges to microvilli and ropy ridges and the expression of urothelial-specific glycoproteins uroplakins was decreased. Ex vivo and in vivo lectin binding experiments gave comparable results. Jacalin (lectin from Artocarpus integrifolia) exhibited the highest selectivity for neoplastic compared to normal urothelium of rats and mice. The binding of lectin from Amaranthus caudatus decreased in rat model and increased in mouse carcinogenesis model, indicating interspecies variations of plasma membrane glycosylation. Lectin from Datura stramonium showed higher affinity for neoplastic urothelium compared to the normal in rat and mouse model. The BBN-induced animal models of bladder carcinogenesis offer a promising approach for lectin binding experiments and further lectin-mediated targeted drug delivery research. Moreover, in vivo lectin binding experiments are comparable to ex vivo experiments, which should be considered when planning and optimizing future research. PMID:23828036

  20. Dietary exposure of 17-alpha ethinylestradiol modulates physiological endpoints and gene signaling pathways in female largemouth bass (Micropterus salmoides)

    PubMed Central

    Colli-Dula, Reyna-Cristina; Martyniuk, Christopher J.; Kroll, Kevin J.; Prucha, Melinda S.; Kozuch, Marianne; Barber, David S.; Denslow, Nancy D.

    2014-01-01

    17alpha-ethinylestradiol (EE2), used for birth control in humans, is a potent estrogen that is found in wastewater at low concentrations (ng/L). EE2 has the ability to interfere with the endocrine system of fish, affecting reproduction which can result in population level effects. The objective of this study was to determine if dietary exposure to EE2 would alter gene expression patterns and key pathways in the liver and ovary and whether these could be associated with reproductive endpoints in female largemouth bass during egg development. Female LMB received 70 ng EE2/g feed (feed administered at 1% of body weight) for 60 days. EE2 dietary exposure significantly reduced plasma vitellogenin concentrations by 70%. Hepatosomatic and gonadosomatic indices were also decreased with EE2 feeding by 38.5% and 40%, respectively. Transcriptomic profiling revealed that there were more changes in steady state mRNA levels in the liver compared to the ovary. Genes associated with reproduction were differentially expressed such as vitellogenin in the liver and aromatase in the gonad. In addition, a set of genes related with oxidative stress (e.g. glutathione reductase and glutathione peroxidase) were identified as altered in the liver and genes associated with the immune system (e.g. complement component 1, and macrophage-inducible C-type lectin) were altered in the gonad. In a follow-up study with 0.2 ng EE2/g feed for 60 days, similar phenotypic and gene expression changes were observed that support these findings with the higher concentrations. This study provides new insights into how dietary exposure to EE2 interferes with endocrine signaling pathways in female LMB during a critical period of reproductive oogenesis. PMID:25203422

  1. Mannose-binding lectin does not explain the course and outcome of pregnancy in rheumatoid arthritis

    PubMed Central

    2011-01-01

    Introduction Rheumatoid arthritis (RA) improves during pregnancy and flares after delivery. It has been hypothesized that high levels of the complement factor mannose-binding lectin (MBL) are associated with a favourable disease course of RA by facilitating the clearance of pathogenic immunoglobulin G (IgG) lacking galactose sugar moieties. During pregnancy, increased galactosylation of IgG and simultaneously increased MBL levels can be observed, with the latter being strictly related to maternal MBL genotypes. Therefore, increased MBL levels in concert with increased IgG galactosylation may be associated with pregnancy-induced improvement of RA. The objective of this study was to investigate whether MBL genotypes are associated with changes in RA disease activity and with changes in IgG galactosylation during pregnancy and in the postpartum period. We also studied the association between MBL genotypes and pregnancy outcomes in RA. Methods Serum from 216 patients with RA and 31 healthy controls participating in the Pregnancy-induced Amelioration of Rheumatoid Arthritis (PARA) Study was collected before, during and after pregnancy. IgG galactosylation was determined by performing matrix-assisted laser desorption/ionization time of flight mass spectrometry. Disease activity was determined using the internationally recognized Disease Activity Score 28 (DAS28). MBL genotypes were determined. The pregnancy outcome measures studied were gestational age, birth weight, miscarriage and hypertensive disorders. Results No association was found between the MBL genotype groups and changes in RA disease activity (P = 0.89) or changes in IgG galactosylation (patients, P = 0.75, and controls, P = 0.54) during pregnancy and in the postpartum period. Furthermore, MBL genotype groups were not related to the studied pregnancy outcome measures. Conclusions This study does not provide evidence for a role for MBL in the improvement of RA during pregnancy or for a role for MBL in pregnancy outcome. PMID:21281477

  2. Structural basis for recognition of high mannose type glycoproteins by mammalian transport lectin VIP36.

    PubMed

    Satoh, Tadashi; Cowieson, Nathan P; Hakamata, Wataru; Ideo, Hiroko; Fukushima, Keiko; Kurihara, Masaaki; Kato, Ryuichi; Yamashita, Katsuko; Wakatsuki, Soichi

    2007-09-21

    VIP36 functions as a transport lectin for trafficking certain high mannose type glycoproteins in the secretory pathway. Here we report the crystal structure of VIP36 exoplasmic/luminal domain comprising a carbohydrate recognition domain and a stalk domain. The structures of VIP36 in complex with Ca(2+) and mannosyl ligands are also described. The carbohydrate recognition domain is composed of a 17-stranded antiparallel beta-sandwich and binds one Ca(2+) adjoining the carbohydrate-binding site. The structure reveals that a coordinated Ca(2+) ion orients the side chains of Asp(131), Asn(166), and His(190) for carbohydrate binding. This result explains the Ca(2+)-dependent carbohydrate binding of this protein. The Man-alpha-1,2-Man-alpha-1,2-Man, which corresponds to the D1 arm of high mannose type glycan, is recognized by eight residues through extensive hydrogen bonds. The complex structures reveal the structural basis for high mannose type glycoprotein recognition by VIP36 in a Ca(2+)-dependent and D1 arm-specific manner. PMID:17652092

  3. Lectin-based Isolation and Culture of Mouse Embryonic Motoneurons

    PubMed Central

    Conrad, Rebecca; Jablonka, Sibylle; Sczepan, Teresa; Sendtner, Michael; Wiese, Stefan; Klausmeyer, Alice

    2011-01-01

    Spinal motoneurons develop towards postmitotic stages through early embryonic nervous system development and subsequently grow out dendrites and axons. Neuroepithelial cells of the neural tube that express Nkx6.1 are the unique precursor cells for spinal motoneurons1. Though postmitotic motoneurons move towards their final position and organize themselves into columns along the spinal tract2,3. More than 90% of all these differentiated and positioned motoneurons express the transcription factors Islet 1/2. They innervate the muscles of the limbs as well as those of the body and the inner organs. Among others, motoneurons typically express the high affinity receptors for brain derived neurotrophic factor (BDNF) and Neurotrophin-3 (NT-3), the tropomyosin-related kinase B and C (TrkB, TrkC). They do not express the tropomyosin-related kinase A (TrkA)4. Beside the two high affinity receptors, motoneurons do express the low affinity neurotrophin receptor p75NTR. The p75NTR can bind all neurotrophins with similar but lower affinity to all neurotrophins than the high affinity receptors would bind the mature neurotrophins. Within the embryonic spinal cord, the p75NTR is exclusively expressed by the spinal motoneurons5. This has been used to develop motoneuron isolation techniques to purify the cells from the vast majority of surrounding cells6. Isolating motoneurons with the help of specific antibodies (panning) against the extracellular domains of p75NTR has turned out to be an expensive method as the amount of antibody used for a single experiment is high due to the size of the plate used for panning. A much more economical alternative is the use of lectin. Lectin has been shown to specifically bind to p75NTR as well7. The following method describes an alternative technique using wheat germ agglutinin for a preplating procedure instead of the p75NTR antibody. The lectin is an extremely inexpensive alternative to the p75NTR antibody and the purification grades using lectin are comparable to that of the p75NTR antibody. Motoneurons from the embryonic spinal cord can be isolated by this method, survive and grow out neurites. PMID:21946816

  4. Complement activation induced by rabbit rheumatoid factor.

    PubMed Central

    Meyer, R R; Brown, J C

    1980-01-01

    Rabbit rheumatoid factor produced in animals by hyperimmunized with group C streptococcal vaccine activated guinea pig complement. Anti-streptococcal serum was fractionated by Sephacryl S-200 chromatography into excluded (19S) and included (7S) material and examined for hemolytic activity in a sensitive homologous hemolytic assay system. In the presence of complement, both 19S and 7S antistreptococcal serum fractions induced lysis of bovine (ox) erythrocytes coated with mildly reduced and carboxymethylated rabbit anti-erythrocyte immunoglobulin G. That rabbit rheumatoid factor was responsible for the observed hemolytic activity was substantiated by hemolytic inhibition assays. Significant inhibition of hemolysis was effected when antistreptococcal serum fractions were incubated in the presence of human immunoglobulin G, rabbit immunoglobulin G, and Fc, whereas, no inhibition was detected when the same fractions were tested in the presence of rabbit Fab or F(ab')2 fragments. Deaggregation of inhibitor preparations revealed a preferential reactivity of rheumatoid factor for rabbit immunoglobulin G. In addition to the rheumatoid factor-dependent hemolytic activity observed in humoral preparations, immunoglobulin G-specific antibody-forming cells in spleen and peripheral blood lymphocyte isolates were enumerated by plaque-forming cell assay. PMID:7399707

  5. An efficient method for the purification and quantification of a galactose-specific lectin from vegetative tissues of Dolichos lablab.

    PubMed

    Rameshwaram, Nagender Rao; Nadimpalli, Siva Kumar

    2008-01-15

    The affinity purified galactose-specific seed lectin from Dolichos lablab, designated as DLL-II, is a tetrameric protein with an apparent native molecular mass of 120 kDa that is composed of two non-identical subunits of 31 and 29 kDa, respectively, associated non-covalently. The stems and leaves of the D. lablab plant also contain a galactose-specific lectin that cross-reacts with the seed lectin antiserum (antiserum raised against the 31 kDa subunit of DLL-II). Anti-lectin antibodies have been purified from this antiserum using a gel containing purified DLL-II lectin. Lectin specific antibodies have been used to develop simple and efficient immuno-affinity matrix, which allowed the purification of the lectin from stems and leaves of the D. lablab. The vegetative lectin (DLL-VL) exhibits similar electrophoretic properties as the seed lectin. Using these antibodies, an ELISA method was developed that allowed quantification of the lectin in the vegetative tissues (stems, leaves and roots) at concentrations of 0.5-50 ng. MS and database analysis of the tryptic peptides of the purified subunits of the DLL-VL suggested the purified protein to be a lectin. PMID:17919997

  6. Glycoproteins, antigens, and regulation of complement activation on the surface of the protozoan parasite Trypanosoma lewisi: implications for immune evasion

    SciTech Connect

    Sturtevant, J.E.

    1985-01-01

    The surface antigens and glycoproteins of the rat parasitic protozoan, Trypanosoma lewisi were characterized. Radioiodination with /sup 125/I identified 10 out of more 40 polypeptides separated on sodium dodecyl sulfate polyacrylamide gel electrophoresis. All of these components were identified as glycoproteins by peroxidase-conjugated Conconavalin A (HR-Con A) lectin affinoblotting. This analysis detected that quantitative but not qualitative changes occurred during infection. Localization of most of the reactive determinants was indicated by immunoblotting extracts of radioiodinated T. lewisi. Changes in the antigenicity as related to survival in the host are discussed. The presence of IgG and IgM on the surface of T. lewisi isolated from intact and ..gamma..-irradiated rats (irr.) and that determinants bind Ig from uninfected rat sera (NRS) was indicated by flow cytometric analysis. Immunoblotting identified the major NRS IgG binding component as the 74 kd surface glycoprotein. Complement component C3 deposition during infection was indicated by flow cytometric analysis and immunoblotting. Incubation of intact T. lewisi with normal human sera indicated that C3, C5, and factor B deposition was Mg/sup 2 +/ dependent, Ca/sup 2 +/ independent and deposited C3 was rapidly processed to hemolytically inactive fragments. Radioiodination of intact and protease T. lewisi after cultivation identified three components which correlate with resistance to lysis. This suggests that surface moieties on intact T. lewisi modulate host complement activity by restricting C3/C5 convertase activity.

  7. Characterization and molecular cloning of mannose-binding lectins from the Orchidaceae species Listera ovata, Epipactis helleborine and Cymbidium hybrid.

    PubMed

    Van Damme, J M; Smeets, K; Torrekens, S; Van Leuven, F; Peumans, W J

    1994-04-15

    Mannose-binding lectins were purified from the leaves of three Orchidaceae species, namely Listera ovata (twayblade), Epipactis helleborine (broad-leaved helleborine) and Cymbidium hybrid, using affinity chromatography on Mannose - Sepharose-4B. Apparently, the Orchidaceae lectins are dimeric proteins composed of lectin subunits of 12-13 kDa. All of the isolated lectins exhibit exclusive specificity towards mannose. A cDNA library constructed from poly(A) rich RNA isolated from leaves of L. ovata was screened for cDNA clones encoding the lectin using colony hybridization. Since N-terminal sequence analysis of the twayblade lectin revealed some sequence similarity to the previously cloned mannose-binding lectin Hippeastrum hybrid (amaryllis) ovaries, the amaryllis lectin cDNA clone was used as a probe to screen the L. ovata library. Subsequently, the cDNA clone encoding the L. ovata lectin was used to screen the cDNA libraries from the taxonomically related orchid species Cymbidium hybrid and E. helleborine. Sequence analysis of the lectin cDNA clones from different Orchidaceae species revealed approximately 50% sequence similarity both at the nucleotide and amino acid level. The Orchidaceae lectins are apparently translated from mRNAs consisting of approximately 800 nucleotides. The primary translation products are preproproteins which are converted into the mature lectins following post-translational modifications. Southern blot analysis of genomic DNA has shown that the lectins are most probably encoded by a family of closely related genes which is in good agreement with the sequence heterogeneity found between different lectin cDNA clones of one species. PMID:8174556

  8. The Semantic Contribution of Complementizers and Complementation Type: The Case of Bolanci "na."

    ERIC Educational Resources Information Center

    Awad, Maher

    A discussion of Bolanci (also Bole or Bolewa), a West Chadic language spoken in northeastern Nigeria, focuses on one component of the system of complementation, the form "na." This form has an inherent semantic capable of influencing the meaning of sentences in which it is embedded, specifically, when present in a complex sentence, communicating…

  9. Infliximab treatment reduces complement activation in patients with rheumatoid arthritis

    PubMed Central

    Familian, A; Voskuyl, A; van Mierlo, G J; Heijst, H; Twisk, J; Dijkmans, B; Hack, C

    2005-01-01

    Background: Tumour necrosis factor (TNF) blocking agents decrease C reactive protein (CRP) levels in rheumatoid arthritis (RA). It has been shown that CRP may contribute to complement activation in RA. Objective: To assess the effect of intravenous infliximab treatment on complement activation, especially that mediated by CRP, in RA. Methods: 35 patients with active RA (28 joint count Disease Activity Score (DAS28) >4.4) were treated with intravenous injections of infliximab (3 mg/kg, at weeks 0, 2, 6, 14, and 22). Clinical response and plasma levels of complement activation products, of CRP and of CRP-complement complexes, which are specific markers for CRP mediated complement activation, were assessed at the indicated time points up to 22 weeks. The relationship between CRP and CRP-complement complexes was analysed by paired t test between two time points and by generalised estimated equation, to test differences of variables over time. Results: At 2 weeks after the first dose, infliximab significantly reduced overall C3 and C4 activation and plasma levels of CRP and CRP-complement complexes were also significantly reduced at this time point. The effects of infliximab on CRP and complement continued throughout the observation period and were more pronounced in patients with a good response to infliximab treatment. Conclusion: Treatment with infliximab decreases plasma levels of CRP and CRP dependent complement activation products and concomitantly may reduce complement activation in RA. Complement activation may be among the effector mechanisms of TNF in RA. PMID:15958758

  10. Differentiation of Helicobacter pylori Isolates Based on Lectin Binding of Cell Extracts in an Agglutination Assay

    PubMed Central

    Hynes, Sean O.; Hirmo, Siiri; Wadström, Torkel; Moran, Anthony P.

    1999-01-01

    Plant and animal lectins with various carbohydrate specificities were used to type 35 Irish clinical isolates of Helicobacter pylori and the type strain NCTC 11637 in a microtiter plate assay. Initially, a panel of eight lectins with the indicated primary specificities were used: Anguilla anguilla (AAA), Lotus tetragonolobus (Lotus A), and Ulex europaeus I (UEA I), specific for ?-l-fucose; Solanum tuberosum (STA) and Triticum vulgaris (WGA), specific for ?-N-acetylglucosamine; Glycine max (SBA), specific for ?-N-acetylgalactosamine; Erythrina cristagali (ECA), specific for ?-galactose and ?-N-acetylgalactosamine; and Lens culinaris (LCA), specific for ?-mannose and ?-glucose. Three of the lectins (SBA, STA, and LCA) were not useful in aiding in strain discrimination. An optimized panel of five lectins (AAA, ECA, Lotus A, UEA I, and WGA) grouped all 36 strains tested into eight lectin reaction patterns. For optimal typing, pretreatment by washing bacteria with a low-pH buffer to allow protein release, followed by proteolytic degradation to eliminate autoagglutination, was used. Lectin types of treated samples were stable and reproducible. No strain proved to be untypeable by this system. Electrophoretic and immunoblotting analyses of lipopolysaccharides (LPSs) indicated that the lectins interact primarily, but not solely, with the O side chain of H. pylori LPS. PMID:10325361

  11. Purification and Characterization of a Lectin from Green Split Peas (Pisum sativum).

    PubMed

    Ng, Tzi Bun; Chan, Yau Sang; Ng, Charlene Cheuk Wing; Wong, Jack Ho

    2015-11-01

    Lectins have captured the attention of a large number of researchers on account of their various exploitable activities, including antitumor, immunomodulatory, antifungal, as well as HIV reverse transcriptase inhibitory activities. A mannose/glucose-specific lectin was isolated from green split peas (a variety of Pisum sativum) and characterized. The purification step involved anion-exchange chromatography on a DEAE-cellulose column, cation-exchange chromatography on an SP-Sepharose column, and gel filtration by fast protein liquid chromatography (FPLC) on Superdex 200. The purified lectin had a native molecular mass of around 50 kDa as determined by size exclusion chromatography. It appeared as a heterotetramer, composed of two distinct polypeptide bands with a molecular mass of 6 and 19 kDa, respectively, in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The N-terminal sequence of green split pea lectin shows some degree of homology compared to lectins from other legume species. Its hemagglutinating activity was inhibited by glucose, mannose, and sucrose, and attenuated at pH values higher than 12 or lower than 3. Hemagglutinating activity was preserved at temperatures lower than 80 °C. The lectin did not show antifungal activity toward fungi including Fusarium oxysporum, Botrytis cinerea, and Mycosphaerella arachidicola. Green split pea lectin showed a mitogenic effect toward murine splenocytes and could inhibit the activity of HIV-1 reverse transcriptase. PMID:26304129

  12. Structure of a lectin with antitumoral properties in king bolete (Boletus edulis) mushrooms.

    PubMed

    Bovi, Michele; Carrizo, Maria E; Capaldi, Stefano; Perduca, Massimiliano; Chiarelli, Laurent R; Galliano, Monica; Monaco, Hugo L

    2011-08-01

    A novel lectin has been isolated from the fruiting bodies of the common edible mushroom Boletus edulis (king bolete, penny bun, porcino or cep) by affinity chromatography on a chitin column. We propose for the lectin the name BEL (B. edulis lectin). BEL inhibits selectively the proliferation of several malignant cell lines and binds the neoplastic cell-specific T-antigen disaccharide, Gal?1-3GalNAc. The lectin was structurally characterized: the molecule is a homotetramer and the 142-amino acid sequence of the chains was determined. The protein belongs to the saline-soluble family of mushroom fruiting body-specific lectins. BEL was also crystallized and its three-dimensional structure was determined by X-ray diffraction to 1.15 Ĺ resolution. The structure is similar to that of Agaricus bisporus lectin. Using the appropriate co-crystals, the interactions of BEL with specific mono- and disaccharides were also studied by X-ray diffraction. The six structures of carbohydrate complexes reported here provide details of the interactions of the ligands with the lectin and shed light on the selectivity of the two distinct binding sites present in each protomer. PMID:21303815

  13. Quantitation of two endogenous lactose-inhibitable lectins in embryonic and adult chicken tissues

    SciTech Connect

    Beyer, E.C.; Barondes, S.H.

    1982-01-01

    Two lactose-binding lectins from chicken tissues, chicken-lactose-lectin-I (CLL-I) and chicken-lactose-lectin-II (CLL-II) were quantified with a radioimmunoassay in extracts of a number of developing and adult chicken tissues. Both lectins could be measured in the same extract without separation, because they showed no significant immunological cross- reactivity. Many embryonic and adult tissues, including brain, heart, intestine, kidney, liver, lung, muscle, pancreas, and spleen, contained one or both lectins, although their concentrations differed markedly. For example, embryonic muscle, the richest source of CLL-I contained only traces of CLL-II whereas embryonic kidney, a very rich source of CLL-II contained substantial CLL-I. In both muscle and kidney, lectin levels in adulthood were much lower than in the embryonic state. In contrast, CLL-I in liver and CLL-II in intestine were 10-fold to 30-fold more concentrated in the adult than in the 15-d embryo. CLL-I and CLL-II from several tissues were purified by affinity chromatography and their identity in the various tissues was confirmed by polyacrylamide gel electrophoresis, isoelectric focusing, and peptide mapping. The results suggest that these lectins might have different functions in the many developing and adult tissues in which they are found.

  14. Structure of a lectin from Canavalia gladiata seeds: new structural insights for old molecules

    PubMed Central

    Delatorre, Plínio; Rocha, Bruno AM; Souza, Emmanuel P; Oliveira, Taianá M; Bezerra, Gustavo A; Moreno, Frederico BMB; Freitas, Beatriz T; Santi-Gadelha, Tatiane; Sampaio, Alexandre H; Azevedo, Walter F; Cavada, Benildo S

    2007-01-01

    Background Lectins are mainly described as simple carbohydrate-binding proteins. Previous studies have tried to identify other binding sites, which possible recognize plant hormones, secondary metabolites, and isolated amino acid residues. We report the crystal structure of a lectin isolated from Canavalia gladiata seeds (CGL), describing a new binding pocket, which may be related to pathogen resistance activity in ConA-like lectins; a site where a non-protein amino-acid, ?-aminobutyric acid (Abu), is bound. Results The overall structure of native CGL and complexed with ?-methyl-mannoside and Abu have been refined at 2.3 Ĺ and 2.31 Ĺ resolution, respectively. Analysis of the electron density maps of the CGL structure shows clearly the presence of Abu, which was confirmed by mass spectrometry. Conclusion The presence of Abu in a plant lectin structure strongly indicates the ability of lectins on carrying secondary metabolites. Comparison of the amino acids composing the site with other legume lectins revealed that this site is conserved, providing an evidence of the biological relevance of this site. This new action of lectins strengthens their role in defense mechanisms in plants. PMID:17683532

  15. Purification and characterization of a lectin from the shellfish, Saxidomus purpuratus.

    PubMed

    Tatsumi, M; Arai, Y; Itoh, T

    1982-04-01

    A lectin was purified from a shellfish, Saxidomus purpuratus, using ion-exchange chromatography on DEAE-cellulose and affinity chromatography on N-acetylglucosamine-Sepharose. The lectin purified by affinity chromatography showed seven protein bands in polyacrylamide gel electrophoresis. The two major lectins (SPA-I and SPA-III) were purified by a second DEAE-cellulose column chromatography. The molecular weights of the lectins were almost the same and were estimated to be around 40,000 by gel filtration on a Sepharose 6B column. On SDS-polyacrylamide gel electrophoresis in the presence of 2-mercaptoethanol, the lectins showed molecular weights of 14,000. The isoelectric points of SPA-I and -III were estimated to be 4.4 and 4.1, respectively. The two lectins (SPA-I and -III) differed slightly in amino acid composition and were glycoproteins containing 2.1 and 3.8 mol of GlcNAc per 40,000 g of the lectin, respectively. The binding constant of SPA-I or SPA-III for methyl N-acetyl-a-D-glucosamide, the strongest inhibitor of hemagglutination in this experiment, was estimated to be 1.3 X 10(3) or 4.2 X 10(4) M-1, respectively, by the UV difference spectroscopy method. PMID:7096281

  16. Purification and partial characterization of a fructose-binding lectin from the leaves of Euphorbia helioscopia.

    PubMed

    Rafiq, Shaista; Qadir, Sakeena; Wani, Ishfak Hussain; Ganie, Showkat Ahmad; Masood, Akbar; Hamid, Rabia

    2014-11-01

    A lectin was purified from leaves of Euphorbia helioscopia, by a combination of ion-exchange and gel filtration chromatography. On ion exchange using a DEAE- cellulose column in 0.2 M phosphate buffer, pH 7.2, the bound protein was eluted with a linear sodium chloride gradient of 0.1 M to 0.5 M. Further purification of the lectin was achieved by gel filtration on Sephadex G-100. Euphorbia helioscopia lectin (EHL) agglutinates only chick erythrocytes, showing no agglutination of all human blood group erythrocytes. The EHL induced hemagglutination is inhibited by fructose. The purified protein showed one band, both in non-denaturing PAGE and SDS-PAGE establishing the charge and size homogeneities of the lectin preparation. The molecular mass of the lectin as indicated by SDS-PAGE was approximately 31 kDa and that estimated from G-100 gel filtration chromatography was about 65 kDa establishing that the lectin is a homodimer. The lectin was stable within a temperature range of 0°C-40°C and exhibited a narrow range of pH stability, being optimally active at around pH 7. EHL also possesses antimicrobial activity and is an inhibitor of bacterial growth particularly Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli. PMID:25362590

  17. Molecular switch role of Akt in Polygonatum odoratum lectin-induced apoptosis and autophagy in human non-small cell lung cancer A549 cells.

    PubMed

    Li, Chunyang; Chen, Jie; Lu, Bangmin; Shi, Zheng; Wang, Hailian; Zhang, Bin; Zhao, Kailiang; Qi, Wei; Bao, Jinku; Wang, Yi

    2014-01-01

    Polygonatum odoratum lectin (POL), isolated from traditional Chinese medicine herb (Mill.) Druce, has drawn rising attention due to its wide biological activities. In the present study, anti-tumor effects, including apoptosis- and autophagy-inducing properties of POL, were determined by a series of cell biology methods such as MTT, cellular morphology observation, flow cytometry, immunoblotting. Herein, we found that POL could simultaneously induce apoptosis and autophagy in human non-small cell lung cancer A549 cells. POL initiated apoptosis through inhibiting Akt-NF-?B pathway, while POL triggered autophagy via suppressing Akt-mTOR pathway, suggesting the molecular switch role of Akt in regulating between POL-induced apoptosis and autophagy. Moreover, ROS was involved in POL-induced inhibition of Akt expression, and might therefore mediate both apoptosis and autophagy in A549 cells. In addition, POL displayed no significant cytotoxicity toward normal human embryonic lung fibroblast HELF cells. Due to the anti-tumor activities, POL might become a potent anti-cancer drug in future therapy, which might pave the way for exploring GNA-related lectins into effective drugs in cancer treatment. PMID:24992302

  18. Hybrids of aneuploid human cancer cells permit complementation of simple and complex cancer defects.

    PubMed

    Dezentje, David A; Arking, Dan E; Kortenhorst, Madeleine S Q; West, Kristen; Chakravarti, Aravinda; Kern, Scott E

    2009-02-01

    Causes for the complex phenotypes of cancers, such as altered differentiation, invasion and metastasis, are not known, and multigenic defects are likely. In contrast, well-defined deficiencies, such as those affecting DNA-repair mechanisms and enzymatic pathways, are simple, typically caused by one or a few gene mutations. Complementation by introducing defined genetic elements is used to study simple cancer phenotypes, while complementation by the fusion of whole cells is employed occasionally for complex ones. Hybrids formed solely from the common lines (aneuploid due to chromosomal instability, CIN) are rarely reported. We created stable hybrids of two CIN lines, producing a nearly complete genetic sum of the parental karyotypes. Complementation of a simple cancer phenotype, a Fanconi anemia pathway defective in both parental lines, occurred in all hybrids, restoring the normal drug-resistance phenotype. The grossly defective mitotic spindle checkpoint present in both parental lines was partially corrected in some hybrids, supporting a multigenic origin rather than a single gene defect. Using Affymetrix 100K SNP chips, we mapped chromosomal loci differing among the phenotypically distinct hybrid clones. Fusing CIN cell lines to form mapped hybrids offers new tools for positional cloning or classification of simple and complex cancer phenotypes, including mechanical defects and altered drug responses. PMID:19305140

  19. Lectin functionalized quantum dots for recognition of mammary tumors

    NASA Astrophysics Data System (ADS)

    Santos, Beate S.; de Farias, Patricia M. A.; de Menezes, Frederico D.; de C. Ferreira, Ricardo; Júnior, Severino A.; Figueiredo, Regina C. B. Q.; Beltrăo, Eduardo I. C.

    2006-02-01

    In this study we use CdS/Cd(OH) II quantum dots functionalized with concanavalin-A (Con-A) lectin, specific to glucose/mannose residues, to investigate cell alterations regarding carbohydrate profile in human mammary tissues diagnosed as fibroadenoma (benign tumor). These particles were functionalized with glutaraldehyde and Con-A and incubated with tissue sections of normal and to Fibroadenoma, a benign type of mammary tumor. The tissue sections were deparafinized, hydrated in graded alcohol and treated with a solution of Evans Blue in order to avoid autofluorescence. The fluorescence intensity of QD-Con-A stained tissues showed different patterns, which reflect the carbohydrate expression of glucose/mannose in fibroadenoma when compared to the detection of the normal carbohydrate expression. The pattern of unspecific labeling of the tissues with glutaraldehyde functionalized CdS/Cd(OH) II quantum dots is compared to the targeting driven by the Con-A lectin. The preliminary findings reported here support the use of CdS/Cd(OH) II quantum dots as specific probes of cellular alterations and their use in diagnostics.

  20. Nkrp1 family, from lectins to protein interacting molecules.

    PubMed

    Rozbeský, Daniel; Ivanova, Ljubina; Hernychová, Lucie; Grobárová, Valéria; Novák, Petr; ?erný, Jan

    2015-01-01

    The C-type lectin-like receptors include the Nkrp1 protein family that regulates the activity of natural killer (NK) cells. Rat Nkrp1a was reported to bind monosaccharide moieties in a Ca2+-dependent manner in preference order of GalNac > GlcNAc > Fuc > Gal > Man. These findings established for rat Nkrp1a have been extrapolated to all additional Nkrp1 receptors and have been supported by numerous studies over the past two decades. However, since 1996 there has been controversy and another article showed lack of interactions with saccharides in 1999. Nevertheless, several high affinity saccharide ligands were synthesized in order to utilize their potential in antitumor therapy. Subsequently, protein ligands were introduced as specific binders for Nkrp1 proteins and three dimensional models of receptor/protein ligand interaction were derived from crystallographic data. Finally, for at least some members of the NK cell C-type lectin-like proteins, the "sweet story" was impaired by two reports in recent years. It has been shown that the rat Nkrp1a and CD69 do not bind saccharide ligands such as GlcNAc, GalNAc, chitotetraose and saccharide derivatives (GlcNAc-PAMAM) do not directly and specifically influence cytotoxic activity of NK cells as it was previously described. PMID:25690298

  1. Essential role of surface-bound complement factor H in controlling immune complex-induced arthritis.

    PubMed

    Banda, Nirmal K; Mehta, Gaurav; Ferreira, Viviana P; Cortes, Claudio; Pickering, Matthew C; Pangburn, Michael K; Arend, William P; Holers, V Michael

    2013-04-01

    Factor H (fH) is an endogenous negative regulator of the alternative pathway (AP) that binds polyanions as well as complement activation fragments C3b and C3d. The AP is both necessary and sufficient to develop collagen Ab-induced arthritis (CAIA) in mice; the mechanisms whereby normal control of the AP is overcome and injury develops are unknown. Although primarily a soluble circulating protein, fH can also bind to tissues in a manner dependent on the carboxyl-terminal domain containing short consensus repeats 19 and 20. We examined the role of fH in CAIA by blocking its binding to tissues through administration of a recombinant negative inhibitor containing short consensus repeats 19 and 20 (rfH19-20), which impairs fH function and amplifies surface AP activation in vitro. Administration of rfH19-20, but not control rfH3-5, significantly worsened clinical disease activity, histopathologic injury, and C3 deposition in the synovium and cartilage in wild-type and fH(+/-) mice. In vitro studies demonstrated that rfH19-20 increased complement activation on cartilage extracts and injured fibroblast-like synoviocytes, two major targets of complement deposition in the joint. We conclude that endogenous fH makes a significant contribution to inhibition of the AP in CAIA through binding to sites of immune complex formation and complement activation. PMID:23436934

  2. Complement Factor H Antibodies from Lung Cancer Patients Induce Complement-Dependent Lysis of Tumor Cells, Suggesting a Novel Immunotherapeutic Strategy.

    PubMed

    Campa, Michael J; Gottlin, Elizabeth B; Bushey, Ryan T; Patz, Edward F

    2015-12-01

    Characterization of the humoral immune response in selected patients with cancer who uniformly do well may lead to the development of novel therapeutic strategies. We have previously shown an association between patients with early-stage nonmetastatic lung cancer and autoantibodies to complement factor H (CFH). CFH protects normal and tumor cells from destruction by the alternative complement pathway by inactivating C3b, a protein that is essential for formation of a lytic complex on the cell surface. Here, we show that CFH autoantibodies in lung cancer patients recognize a conformationally distinct form of CFH in vitro, are IgG3 subclass, and epitope map to a crucial functional domain of CFH known to interact with C3b. Purified CFH autoantibodies inhibited binding of CFH to A549 lung tumor cells, increased C3b deposition, and caused complement-dependent tumor cell lysis. This work demonstrates that CFH autoantibodies isolated from patients with lung cancer can kill tumor cells in vitro, suggesting that they may perform this function in vivo as well. Development of specific antibodies to the conformationally distinct epitope of CFH may lead to a useful biologic therapy for lung cancer. Cancer Immunol Res; 3(12); 1325-32. ©2015 AACR. PMID:26216416

  3. Genomic sequence and organization of two members of a human lectin gene family

    SciTech Connect

    Gitt, M.A.; Barondes, S.H. )

    1991-01-01

    The authors have isolated and sequenced the genomic DNA encoding a human dimeric soluble lactose-binding lectin. The gene has four exons, and its upstream region contains sequences that suggest control by glucocorticoids, heat (environmental) shock, metals, and other factors. They have also isolated and sequenced three exons of the gene encoding another human putative lectin, the existence of which was first indicated by isolation of its cDNA. Comparisons suggest a general pattern of genomic organization of members of this lectin gene family.

  4. ?-N-Linked glycopeptides: conformational analysis and bioactivity as lectin ligands.

    PubMed

    Marcelo, Filipa; Cańada, Francisco Javier; André, Sabine; Colombo, Cinzia; Doro, Fabio; Gabius, Hans-Joachim; Bernardi, Anna; Jiménez-Barbero, Jesús

    2012-08-14

    Natural N-glycosylation involves a ?-anomeric linkage connecting the sugar to one asparagine residue of the protein. We herein report NMR- and modelling-based data on glycomimetics containing ?-glycosidic linkages. The bioactivity of ?-Gal-containing glycopeptides has been documented by revealing binding to two plant lectins, i.e. a potent ?-trefoil toxin (Viscum album agglutinin) and ?-sandwich lectin (Erythrina corallodendron agglutinin), by NMR protocols. Docking provided insights into the 3D structures of the resulting complexes. These results provide the basis to introduce ?-substituted neoglycopeptides to the toolbox of scaffold for the design of potent lectin inhibitors. PMID:22441147

  5. Immobilized Doxorubicin Increases the Complement Susceptibility of Human Melanoma Cells by Protecting Complement Component C3b against Inactivation

    NASA Astrophysics Data System (ADS)

    Panneerselvam, Mounanandham; Bredehorst, Reinhard; Vogel, Carl-Wilhelm

    1986-12-01

    Human melanoma cells resistant to killing by monoclonal antibody R24 plus human complement became susceptible after treatment with doxorubicin (adriamycin). Treatment with doxorubicin prevented the rapid degradation of surface-bound complement component C3b that has been identified as a protective mechanism of complement-resistant melanoma cells. Doxorubicin caused the increased complement susceptibility as free drug and after immobilization onto glass beads to prevent cellular uptake. Immobilized doxorubicin was more effective than free drug, causing enhanced complement susceptibility at concentrations where the free drug was no longer active. In contrast to free doxorubicin, which exhibited a direct cytotoxic effect leading to cell death within 4 days, immobilized doxorubicin did not affect cell viability. These findings suggest that combination therapy of the complement-activating monoclonal antibody R24 with the complement-enhancing drug doxorubicin may be a promising approach for the treatment of melanoma.

  6. Complement Component C5a Primes Retinal Pigment Epithelial Cells for Inflammasome Activation by Lipofuscin-mediated Photooxidative Damage.

    PubMed

    Brandstetter, Carolina; Holz, Frank G; Krohne, Tim U

    2015-12-25

    Complement activation, oxidative damage, and activation of the NLRP3 inflammasome have been implicated in retinal pigment epithelium (RPE) pathology in age-related macular degeneration (AMD). Following priming of RPE cells, the NLRP3 inflammasome can be activated by various stimuli such as lipofuscin-mediated photooxidative damage to lysosomal membranes. We investigated whether products of complement activation are capable of providing the priming signal for inflammasome activation in RPE cells. We found that incubation of primary human RPE cells and ARPE-19 cells with complement-competent human serum resulted in up-regulation of C5a receptor, but not C3a receptor. Furthermore, human serum induced expression of pro-IL-1? and enabled IL-1? secretion in response to lipofuscin phototoxicity, thus indicating inflammasome priming. Complement heat-inactivation, C5 depletion, and C5a receptor inhibition suppressed the priming effect of human serum whereas recombinant C5a likewise induced priming. Conditioned medium of inflammasome-activated RPE cells provided an additional priming effect that was mediated by the IL-1 receptor. These results identify complement activation product C5a as a priming signal for RPE cells that allows for subsequent inflammasome activation by stimuli such as lipofuscin-mediated photooxidative damage. This molecular pathway provides a functional link between key factors of AMD pathogenesis including lipofuscin accumulation, photooxidative damage, complement activation, and RPE degeneration and may provide novel therapeutic targets in this disease. PMID:26565031

  7. Oxygen radicals mediate endothelial cell damage by complement-stimulated granulocytes. An in vitro model of immune vascular damage.

    PubMed Central

    Sacks, T; Moldow, C F; Craddock, P R; Bowers, T K; Jacob, H S

    1978-01-01

    During hemodialysis, alternative pathway complement activation leads to pulmonary sequestration of granulocytes, with loss of pulmonary vascular endothelial integrity and, at times, protein-rich pulmonary edema. An in vitro model of this phenomenon was constructed utilizing 51Cr-labeled human umbilical vein endothelial cell cultures. In this system, granulocytes, when exposed to activated complement (C), induce endothelial damage; this injury is mediated primarily by oxygen radicals produced by the granulocytes. C5a appears to be the C component responsible for granulocyte-induced cytotoxicity; studies with cytochalasin B-treated granulocytes suggest that close approximation of the granulocytes and endothelial cells is necessary for maximal cell injury. PMID:207729

  8. Complementation of chromosomal aberrations in AT/NBS hybrids: inadequacy of RDS as an endpoint in complementation studies with immortal NBS cells.

    PubMed

    Kraakman-van der Zwet, M; Overkamp, W J; Jaspers, N G; Natarajan, A T; Lohman, P H; Zdzienicka, M Z

    2001-04-01

    Nijmegen breakage syndrome (NBS) and ataxia telangiectasia (AT) are rare autosomal recessive hereditary disorders characterized by radiosensitivity, chromosomal instability, immunodeficiency and proneness to cancer. Although the clinical features of both syndromes are quite distinct, the cellular characteristics are very similar. Cells from both NBS and AT patients are hypersensitive to ionizing radiation (IR), show elevated levels of chromosomal aberrations and display radioresistant DNA synthesis (RDS). The proteins defective in NBS and AT, NBS1 and ATM, respectively, are involved in the same pathway, but their exact relationship is not yet fully understood. Stumm et al. (Am. J. Hum. Genet. 60 (1997) 1246) have reported that hybrids of AT and NBS lymphoblasts were not complemented for chromosomal aberrations. In contrast, we found that X-ray-induced cell killing as well as chromosomal aberrations were complemented in proliferating NBS-1LBI/AT5BIVA hybrids, comparable to that in NBS-1LBI cells after transfer of a single human chromosome 8 providing the NBS1 gene. RDS observed in AT5BIVA cells was reduced in these hybrids to the level of that seen in immortal NBS-1LBI cells. However, the level of DNA synthesis, following ionizing radiation, in SV40 transformed wild-type cell lines was the same as in NBS-1LBI cells. Only primary wild-type cells showed stronger inhibition of DNA synthesis. In summary, these results clearly indicate that RDS cannot be used as an endpoint in functional complementation studies with immortal NBS-1LBI cells, whereas the cytogenetic assay is suitable for complementation studies with immortal AT and NBS cells. PMID:11267829

  9. Structural analysis of Canavalia maritima and Canavalia gladiata lectins complexed with different dimannosides: new insights into the understanding of the structure-biological activity relationship in legume lectins.

    PubMed

    Bezerra, Gustavo Arruda; Oliveira, Taianá Maia; Moreno, Frederico Bruno Mendes Batista; de Souza, Emmanuel Prata; da Rocha, Bruno Anderson Matias; Benevides, Raquel Guimarăes; Delatorre, Plínio; de Azevedo, Walter Filgueira; Cavada, Benildo Sousa

    2007-11-01

    Plant lectins, especially those purified from species of the Leguminosae family, represent the best studied group of carbohydrate-binding proteins. The legume lectins from Diocleinae subtribe are highly similar proteins that present significant differences in the potency/efficacy of their biological activities. The structural studies of the interactions between lectins and sugars may clarify the origin of the distinct biological activities observed in this high similar class of proteins. In this way, this work presents a crystallographic study of the ConM and CGL (agglutinins from Canavalia maritima and Canavalia gladiata, respectively) in the following complexes: ConM/CGL:Man(alpha1-2)Man(alpha1-O)Me, ConM/CGL:Man(alpha1-3)Man(alpha1-O)Me and ConM/CGL:Man(alpha1-4)Man(alpha1-O)Me, which crystallized in different conditions and space group from the native proteins. The structures were solved by molecular replacement, presenting satisfactory values for R(factor) and R(free). Comparisons between ConM, CGL and ConA (Canavalia ensiformis lectin) binding mode with the dimannosides in subject, presented different interactions patterns, which may account for a structural explanation of the distincts biological properties observed in the lectins of Diocleinae subtribe. PMID:17881248

  10. Lectin staining and Western blot data showing differential sialylation of nutrient-deprived cancer cells to sialic acid supplementation

    PubMed Central

    Badr, Haitham A.; AlSadek, Dina M.M.; Mathew, Mohit P.; Li, Chen-Zhong; Djansugurova, Leyla B.; Yarema, Kevin J.; Ahmed, Hafiz

    2015-01-01

    This report provides data that are specifically related to the differential sialylation of nutrient deprived breast cancer cells to sialic acid supplementation in support of the research article entitled, “Nutrient-deprived cancer cells preferentially use sialic acid to maintain cell surface glycosylation" [1]. Particularly, breast cancer cells, when supplemented with sialic acid under nutrient deprivation, display sialylated glycans at the cell surface, but non-malignant mammary cells show sialylated glycans intracellularly. The impact of sialic acid supplementation under nutrient deprivation was demonstrated by measuring levels of expression and sialylation of two markers, EGFR1 and MUC1. This Data in Brief article complements the main manuscript by providing detailed instructions and representative results for cell-level imaging and Western blot analyses of changes in sialylation during nutrient deprivation and sialic acid supplementation. These methods can be readily generalized for the study of many types of glycosylation and various glycoprotein markers through the appropriate selection of fluorescently-labeled lectins. PMID:26629491

  11. Anaphylatoxin receptors and complement regulatory proteins in human articular and non-articular chondrocytes: interrelation with cytokines.

    PubMed

    Schulze-Tanzil, Gundula; Kohl, Benjamin; El Sayed, Karym; Arens, Stephan; Ertel, Wolfgang; Stölzel, Katharina; John, Thilo

    2012-12-01

    Tissue trauma induces an inflammatory response associated with a cytokine release that may engage complement pathways. Cytokine-mediated complement expression may contribute to cartilage degradation. Hence, we analysed the complement expression profile in primary articular and non-articular chondrocytes and its interrelation with cytokines. The expression of the anaphylatoxin receptors (C3aR and C5aR) and the complement regulatory proteins (CPRs) CD35, CD46, CD55 and CD59 was studied in cultured articular, auricular and nasoseptal chondrocytes using RTD-PCR and immunofluorescence labelling. The complement profile of peripheral blood mononuclear cells (PBMCs) was opposed to the expression in articular chondrocytes. The time-dependent regulation (6 and 24 h) of these complement factors was assessed in articular chondrocytes in response to the cytokines TNF?, IL-10 or TNF? combined with IL-10 (each 10 ng/mL). C3aR, C5aR, CD46, CD55 and CD59 but almost no CD35 mRNA was expressed in any of chondrocyte types studied. The anaphylatoxin receptor expression was lower and that of the CRPs was higher in chondrocytes when compared with PBMCs. The majority of the studied complement factors were expressed at a significantly lower level in non-articular chondrocytes compared with the articular chondrocytes. TNF? significantly increased the C3aR expression in chondrocytes after 6 and 24 h. TNF? + IL-10 significantly downregulated C5aR and IL-10 significantly inhibited the CD46 and CD55 gene expression after 24 h. C5aR and CD55 could be localised in cartilage in situ. Anaphylatoxin receptors and CRPs are regulated differentially by TNF? and IL-10. Whether cytokine-induced complement activation occurs in response to cartilage trauma has to be further identified. PMID:23053049

  12. Mouse Macrophage Galactose-type Lectin (mMGL) is Critical for Host Resistance against Trypanosoma cruzi Infection

    PubMed Central

    Vázquez, Alicia; de Dios Ruiz-Rosado, Juan; Terrazas, Luis I.; Juárez, Imelda; Gomez-Garcia, Lorena; Calleja, Elsa; Camacho, Griselda; Chávez, Ana; Romero, Miriam; Rodriguez, Tonathiu; Espinoza, Bertha; Rodriguez-Sosa, Miriam

    2014-01-01

    The C-type lectin receptor mMGL is expressed exclusively by myeloid antigen presenting cells (APC) such as dendritic cells (DC) and macrophages (M?), and it mediates binding to glycoproteins carrying terminal galactose and ?- or ?-N-acetylgalactosamine (Gal/GalNAc) residues. Trypanosoma cruzi (T. cruzi) expresses large amounts of mucin (TcMUC)-like glycoproteins. Here, we show by lectin-blot that galactose moieties are also expressed on the surface of T. cruzi. Male mMGL knockout (-/-) and wild-type (WT) C57BL/6 mice were infected intraperitoneally with 104 T. cruzi trypomastigotes (Queretaro strain). Following T. cruzi infection, mMGL-/- mice developed higher parasitemia and higher mortality rates compared with WT mice. Although hearts from T. cruzi-infected WT mice presented few amastigote nests, mMGL-/- mice displayed higher numbers of amastigote nests. Compared with WT, M? from mMGL-/- mice had low production of nitric oxide (NO), interleukin (IL)-12 and tumor necrosis factor (TNF)-? in response to soluble T. cruzi antigens (TcAg). Interestingly, upon in vitro T. cruzi infection, mMGL-/- M? expressed lower levels of MHC-II and TLR-4 and harbored higher numbers of parasites, even when mMGL-/- M? were previously primed with IFN-? or LPS/IFN-?. These data suggest that mMGL plays an important role during T. cruzi infection, is required for optimal M? activation, and may synergize with TLR-4-induced pathways to produce TNF-?, IL-1? and NO during the early phase of infection. PMID:25170304

  13. Detection of Sugar-Lectin Interactions by Multivalent Dendritic Sugar Functionalized Single-Walled Carbon Nanotubes

    E-print Network

    Vasu, K S; Bagul, R S; Jayaraman, N; Sood, A K; 10.1063/1.4739793

    2012-01-01

    We show that single walled carbon nanotubes (SWNT) decorated with sugar functionalized poly (propyl ether imine) (PETIM) dendrimer is a very sensitive platform to quantitatively detect carbohydrate recognizing proteins, namely, lectins. The changes in electrical conductivity of SWNT in field effect transistor device due to carbohydrate - protein interactions form the basis of present study. The mannose sugar attached PETIM dendrimers undergo charge - transfer interactions with the SWNT. The changes in the conductance of the dendritic sugar functionalized SWNT after addition of lectins in varying concentrations were found to follow the Langmuir type isotherm, giving the concanavalin A (Con A) - mannose affinity constant to be 8.5 x 106 M-1. The increase in the device conductance observed after adding 10 nM of Con A is same as after adding 20 \\muM of a non - specific lectin peanut agglutinin, showing the high specificity of the Con A - mannose interactions. The specificity of sugar-lectin interactions was chara...

  14. Novel hemagglutinating, hemolytic and cytotoxic activities of the intermediate subunit of Entamoeba histolytica lectin

    PubMed Central

    Kato, Kentaro; Yahata, Kazuhide; Gopal Dhoubhadel, Bhim; Fujii, Yoshito; Tachibana, Hiroshi

    2015-01-01

    Galactose and N-acetyl-D-galactosamine (Gal/GalNAc) inhibitable lectin of Entamoeba histolytica, a common protozoan parasite, has roles in pathogenicity and induction of protective immunity in mouse models of amoebiasis. The lectin consists of heavy (Hgl), light (Lgl), and intermediate (Igl) subunits. Hgl has lectin activity and Lgl does not, but little is known about the activity of Igl. In this study, we assessed various regions of Igl for hemagglutinating activity using recombinant proteins expressed in Escherichia coli. We identified a weak hemagglutinating activity of the protein. Furthermore, we found novel hemolytic and cytotoxic activities of the lectin, which resided in the carboxy-terminal region of the protein. Antibodies against Igl inhibited the hemolytic activity of Entamoeba histolytica trophozoites. This is the first report showing hemagglutinating, hemolytic and cytotoxic activities of an amoebic molecule, Igl. PMID:26354528

  15. Diagnostic value of interactions between members of the family Neisseriaceae and lectins.

    PubMed Central

    Doyle, R J; Nedjat-Haiem, F; Keller, K F; Frasch, C E

    1984-01-01

    The lectin slide agglutination test for Neisseria gonorrhoeae has been modified and improved. Results show that wheat germ agglutinin and soybean lectin agglutinate 100% (193 of 193 tested) of clinical isolates of N. gonorrhoeae. Lectin-reactive meningococci can be readily identified by the hydrolysis of gamma-glutamyl-beta-naphthylamide. Branhamella catarrhalis, Neisseria lactamica, Neisseria sicca, Neisseria subflava, Neisseria perflava, and meningococcal serogroups A, B, C, X, Y, and Z do not interfere with the positive identification of N. gonorrhoeae. The frequently encountered problem of autoagglutination of members of the family Neisseriaceae may be circumvented by a short treatment of cellular suspensions with DNase. Based on agglutination assays, the enzyme treatment did not result in a loss of wheat germ agglutinin receptors from the bacteria. The lectin agglutination test, coupled with the gamma-glutamyl aminopeptidase assay, is proposed as a rapid and accurate means of identifying clinical isolates of gonococci. PMID:6546936

  16. Entomotoxic and nematotoxic lectins and protease inhibitors from fungal fruiting bodies.

    PubMed

    Saboti?, Jerica; Ohm, Robin A; Künzler, Markus

    2016-01-01

    Fruiting bodies or sporocarps of dikaryotic (ascomycetous and basidiomycetous) fungi, commonly referred to as mushrooms, are often rich in entomotoxic and nematotoxic proteins that include lectins and protease inhibitors. These protein toxins are thought to act as effectors of an innate defense system of mushrooms against animal predators including fungivorous insects and nematodes. In this review, we summarize current knowledge about the structures, target molecules, and regulation of the biosynthesis of the best characterized representatives of these fungal defense proteins, including galectins, beta-trefoil-type lectins, actinoporin-type lectins, beta-propeller-type lectins and beta-trefoil-type chimerolectins, as well as mycospin and mycocypin families of protease inhibitors. We also present an overview of the phylogenetic distribution of these proteins among a selection of fungal genomes and draw some conclusions about their evolution and physiological function. Finally, we present an outlook for future research directions in this field and their potential applications in medicine and crop protection. PMID:26521246

  17. Developmentally regulated expression by Trypanosoma cruzi of molecules that accelerate the decay of complement C3 convertases

    SciTech Connect

    Rimoldi, M.T.; Sher, A.; Heiny, A.; Lituchy, A.; Hammer, C.H.; Joiner, K.

    1988-01-01

    The authors recently showed that culture-derived metacyclic trypomastigotes (CMT), but not epimastigotes (Epi), of the Miranda 99 strain of Trypanosoma cruzi evade lysis by the human alternative complement pathway because of inefficient binding of factor B to complement component C3b on the parasite surface. These results suggested that CMT and tissue-culture-derived trypomastigotes (TCT), which also activate the alternative pathway poorly, might produce a molecule capable of interfering with factor B binding to C3b. They now demonstrate that CMT and TCT lysates, as well as molecules spontaneously shed from CMT and TCT but not Epi, accelerate decay of /sup 125/I-labeled factor Bb from the alternative-pathway C3 convertase (C3bBb) assembled on zymosan or Epi and also accelerate decay of the classical-pathway C3 convertase (C4b2a) on sheep erythrocytes. Parasites metabolically labeled with (/sup 35/S)methionine spontaneously shed a limited number of radioactive components, ranging in molecular mass from 86 to 155 kDa for trypomastigotes and 25 to 80 kDa for Epi. Decay-accelerating activity within supernatants is inactivated by papain and is coeluted with /sup 35/S-containing polypeptides on FPLC anion-exchange chromatography, suggesting that the active constituents are protein molecules. Molecules with decay-accelerating activity may explain the developmentally regulated resistance to complement-mediated lysis in infective and vertebrate stages for T. cruzi life cycle.

  18. Complement complex C5b-8 induces PGI/sub 2/ formation in culture endothelial cells

    SciTech Connect

    Suttorp, N.; Seeger, W.; Zinsky, S.; Bhakdi, S.

    1987-07-01

    The effects of the terminal complement sequence on prostacyclin (PGI/sub 2/) generation in antibody-sensitized pulmonary arterial endothelial cells were examined. Whereas C5b-7 complement complexes induced no PGI/sub 2/ formation, addition of purified complement component C8 resulted in a time- and dose-dependent burst of PGI/sub 2/ release in the absence of overt cell damage. Formation of the complete terminal complement complex C5b-9 enhanced PGI/sub 2/ release but was accompanied by cytolysis. Extracellular Ca/sup 2 +/ was required for C5b-8-dependent PGI/sub 2/ formation. Three different blockers of physiological calcium channels failed to suppress the observed stimulatory effect. In contrast, W7 (N-(6-amino-hexyl)-5-chloro-1-napththalene sulfonamide) and trifluoperazine, inhibitors of calmodulin activity, all reduced the C5b-8-dependent PGI/sub 2/ generation. None of the inhibitors used impaired Ca/sup 2 +/ flux into the cells. One minute after addition of C8 to endothelial cells carrying C5b-7 complexes, a six- to seven-fold enhanced passive influx of /sup 45/Ca/sup 2 +/ into the cells was noted. An enhanced passive influx was also observed for /sup 51/CrO/sub 4//sup 2 -/, (/sup H/) aminobutyric acid, and (/sup 3/H) sucrose, but not for (/sup 3/H)inulin and (/sup 3/H)dextran. These data together suggest that complement C5b-8 complexes may serve as Ca/sup 2 +/bypass gates in endothelial cells, the ensuring influx of Ca/sup 2 +/ leading to subsequent activation of the arachiodonic acid pathway.

  19. Complement component C6 deficiency in a Spanish family: implications for clinical and molecular diagnosis.

    PubMed

    Moya-Quiles, M R; Bernardo-Pisa, M V; Martínez, P; Gimeno, L; Bosch, A; Salgado, G; Martínez-Banaclocha, H; Eguia, J; Campillo, J A; Muro, M; Vidal-Bugallo, J B; Alvarez-López, M R; García-Alonso, A M

    2013-05-25

    Complement component C6 deficiency is a genetic disease presenting as increased susceptibility to invasive Neisseria meningitidis infections. This disorder has rarely been diagnosed in the Spanish population. In this work we report the immunochemical and molecular characterization of complement C6 deficiency in a Spanish patient showing no detectable functional activity of either the classical or alternative complement pathways and reporting a history of several episodes of meningococcal meningitis. The levels of individual complement components C3, C4, C5, C7, C8 and C9 were within the normal range. However, C6 level was low in the patient's serum as measured by radial immunodiffusion. Exon-specific polymerase chain reaction and sequencing of the C6 gene revealed a previously described homozygous single base deletion in exon 6 (c.821delA), leading to a shift in the reading frame that caused the generation of a downstream stop codon, which, in turn, provoked the truncation of the C6 protein (p.Gln274fs). To our knowledge, this is the first report on the c.821delA mutation in the Spanish population, which has previously only been identified in individuals of African ancestry. Characterization of this mutation was thought interesting in order to elucidate its source and help understand the molecular basis of this uncommon deficiency in our population. Moreover, this report highlights the importance of complement screening in cases of repeated meningococcal infections in order to establish its involvement and to consider adequate clinical recommendations such as prophylactic antibiotics or meningococcal vaccines and, subsequently, for genetic counselling. PMID:23537992

  20. Initiation and Regulation of Complement during Hemolytic Transfusion Reactions

    PubMed Central

    Stowell, Sean R.; Winkler, Anne M.; Maier, Cheryl L.; Arthur, C. Maridith; Smith, Nicole H.; Girard-Pierce, Kathryn R.; Cummings, Richard D.; Zimring, James C.; Hendrickson, Jeanne E.

    2012-01-01

    Hemolytic transfusion reactions represent one of the most common causes of transfusion-related mortality. Although many factors influence hemolytic transfusion reactions, complement activation represents one of the most common features associated with fatality. In this paper we will focus on the role of complement in initiating and regulating hemolytic transfusion reactions and will discuss potential strategies aimed at mitigating or favorably modulating complement during incompatible red blood cell transfusions. PMID:23118779

  1. Altmetrics – a complement to conventional metrics

    PubMed Central

    Melero, Remedios

    2015-01-01

    Emerging metrics based on article-level does not exclude traditional metrics based on citations to the journal, but complements them. Both can be employed in conjunction to offer a richer picture of an article use from immediate to long terms. Article-level metrics (ALM) is the result of the aggregation of different data sources and the collection of content from multiple social network services. Sources used for the aggregation can be broken down into five categories: usage, captures, mentions, social media and citations. Data sources depend on the tool, but they include classic metrics indicators based on citations, academic social networks (Mendeley, CiteULike, Delicious) and social media (Facebook, Twitter, blogs, or Youtube, among others). Altmetrics is not synonymous with alternative metrics. Altmetrics are normally early available and allow to assess the social impact of scholarly outputs, almost at the real time. This paper overviews briefly the meaning of altmetrics and describes some of the existing tools used to apply this new metrics: Public Library of Science - Article-Level Metrics, Altmetric, Impactstory and Plum. PMID:26110028

  2. Lectin-tagged fluorescent polymeric nanoparticles for targeting of sialic acid on living cells.

    PubMed

    Cho, Jaebum; Kushiro, Keiichiro; Teramura, Yuji; Takai, Madoka

    2014-06-01

    In this study, we fabricated lectin-tagged fluorescent polymeric nanoparticles approximately 35 nm in diameter using biocompatible polymers conjugated with lectins for the purpose of detecting sialic acid on a living cell surface, which is one of the most important biomarkers for cancer diagnosis. Through cellular experiments, we successfully detected sialic acid overexpression on cancerous cells with high specificity. These fluorescent polymeric nanoparticles can be useful as a potential bioimaging probe for detecting diseased cells. PMID:24761752

  3. Interaction of Campylobacter jejuni and Campylobacter coli with lectins and blood group antibodies.

    PubMed Central

    Wong, K H; Skelton, S K; Feeley, J C

    1985-01-01

    Lectins and blood group antibodies were used to probe the surface structures of Campylobacter jejuni and Campylobacter coli. Of the 29 strains tested, there were distinct reaction patterns. The lectin-reactive and blood group antibody-reactive sites on the bacterial surface were distinguishable from the heat-stable (lipopolysaccharide) antigenic determinants. The interactions were strain specific. The reactive sites were stable with respect to culture media and passage and may be useful as additional markers for strain characterization. PMID:2410445

  4. Potential use of the Macrobrachium rosenbergii lectin for diagnosis of T-cell acute lymphoblastic leukemia.

    PubMed

    Pérez-Campos-Mayoral, Laura; Ruiz-Argüelles, Alejandro; Pérez-Romano, Beatriz; Zenteno, Edgar; Hernández-Cruz, Pedro; Martínez-Cruz, Ruth; Martínez-Cruz, Margarito; Pina-Canseco, Socorro; Pérez-Campos, Eduardo

    2008-01-01

    T-cell acute lymphoblastic leukemia is the most common form of cancer in children. Lectins are proteins or glycoproteins from plants or animals that recognize oligossacharides on the cell surface and have been used to characterize the structural changes of oligosaccharides in leukemias. In this study, we used the lectin from the freshwater prawn Macrobrachium (M. rosenbergii), specific for acetyl groups in sialylated glycans, because increased sialylation of glycoproteins and glycolipids has been identified in lymphoblastic leukemias. We compared the specificity of the M. rosenbergii lectin for lymphoblastic leukemias with the specificities of the lectins from Triticum vulgaris, Solanum tuberosum, Arachis hipogaea, and Phytolacca americana. By morphologic and phenotype characterization with a panel of monoclonal antibodies, we identified four types of leukemias from 106 leukemia patients: 11 cases of T-cell acute lymphoblastic leukemia, 61 cases of B-cell acute lymphoblastic leukemia, 24 cases of acute myeloblastic leukemia, and 10 cases of acute biphenotypic leukemia. As determined by cytofluorometric assays, nine of the eleven cases with T-cell acute lymphoblastic leukemia (8 +/- 3 years old) were specifically identified with the lectin from M. rosenbergii. In contrast, only six cases of B-cell leukemia, one case of myeloblastic leukemia, and 2 cases of biphenotypic leukemia were identified with this M. rosenbergii lectin. The other lectins tested showed no capacity to differentiate, in a significant manner, any of the four types of leukemias tested. Thus, the lectin from M. rosenbergii could be considered a useful tool for the diagnosis and study of T-cell acute lymphoblastic leukemia. PMID:18212483

  5. A C-Type Lectin from Bothrops jararacussu Venom Disrupts Staphylococcal Biofilms

    PubMed Central

    Klein, Raphael Contelli; Fabres-Klein, Mary Hellen; de Oliveira, Leandro Licursi; Feio, Renato Neves; Malouin, François; Ribon, Andréa de Oliveira Barros

    2015-01-01

    Bovine mastitis is a major threat to animal health and the dairy industry. Staphylococcus aureus is a contagious pathogen that is usually associated with persistent intramammary infections, and biofilm formation is a relevant aspect of the outcome of these infections. Several biological activities have been described for snake venoms, which led us to screen secretions of Bothrops jararacussu for antibiofilm activity against S. aureus NRS155. Crude venom was fractionated by size-exclusion chromatography, and the fractions were tested against S. aureus. Biofilm growth, but not bacterial growth, was affected by several fractions. Two fractions (15 and 16) showed the best activities and were also assayed against S. epidermidis NRS101. Fraction 15 was identified by TripleTOF mass spectrometry as a galactose-binding C-type lectin with a molecular weight of 15 kDa. The lectin was purified from the crude venom by D-galactose affinity chromatography, and only one peak was observed. This pure lectin was able to inhibit 75% and 80% of S. aureus and S. epidermidis biofilms, respectively, without affecting bacterial cell viability. The lectin also exhibited a dose-dependent inhibitory effect on both bacterial biofilms. The antibiofilm activity was confirmed using scanning electron microscopy. A pre-formed S. epidermidis biofilm was significantly disrupted by the C-type lectin in a time-dependent manner. Additionally, the lectin demonstrated the ability to inhibit biofilm formation by several mastitis pathogens, including different field strains of S. aureus, S. hyicus, S. chromogenes, Streptococcus agalactiae, and Escherichia coli. These findings reveal a new activity for C-type lectins. Studies are underway to evaluate the biological activity of these lectins in a mouse mastitis model. PMID:25811661

  6. Mannose-specific lectins that inhibit HIV infection bind nonspecifically to HIV Env-expressing cells.

    PubMed

    Chau, Deborah; Yee, Michael; Gebremedhin, Senait; Cheung, Jennifer; Chino, Takahiro; Düzgüne?, Nejat

    2015-02-01

    An approach to curing HIV/AIDS is to specifically kill all infected cells. Because the lectins, Hippeastrum hybrid agglutinin (HHA) and Galanthus nivalis agglutinin (GNA), are potent inhibitors of HIV infection and bind the oligomannans on the HIV Env protein, we hypothesized that they would bind specifically to cells expressing the HIV Env protein on their plasma membrane. Flow cytometry experiments indicated, however, that these lectins bind equivalently to both Env-expressing and control cells without Env. PMID:25868224

  7. Structural analysis of two crystal forms of lentil lectin at 1.8 A resolution.

    PubMed

    Loris, R; Van Overberge, D; Dao-Thi, M H; Poortmans, F; Maene, N; Wyns, L

    1994-12-01

    The structures of two crystal forms of lentil lectin are determined and refined at high resolution. Orthorhombic lentil lectin is refined at 1.80 A resolution to an R-factor of 0.184 and monoclinic lentil lectin at 1.75 A resolution to an R-factor of 0.175. These two structures are compared to each other and to the other available legume lectin structures. The monosaccharide binding pocket of each lectin monomer contains a tightly bound phosphate ion. This phosphate makes hydrogen bonding contacts with Asp-81 beta, Gly-99 beta, and Asn-125 beta, three residues that are highly conserved in most of the known legume lectin sequences and essential for monosaccharide recognition in all legume lectin crystal structures described thus far. A detailed analysis of the composition and properties of the hydrophobic contact network and hydrophobic nuclei in lentil lectin is presented. Contact map calculations reveal that dense clusters of nonpolar as well as polar side chains play a major role in secondary structure packing. This is illustrated by a large cluster of 24 mainly hydrophobic amino acids that is responsible for the majority of packing interactions between the two beta-sheets. Another series of four smaller and less hydrophobic clusters is found to mediate the packing of a number of loop structures upon the front sheet. A very dense, but not very conserved cluster is found to stabilize the transition metal binding site. The highly conserved and invariant nonpolar residues are distributed asymmetrically over the protein. PMID:7731952

  8. Complement system in dermatological diseases - fire under the skin.

    PubMed

    Panelius, Jaana; Meri, Seppo

    2015-01-01

    The complement system plays a key role in several dermatological diseases. Overactivation, deficiency, or abnormality of the control proteins are often related to a skin disease. Autoimmune mechanisms with autoantibodies and a cytotoxic effect of the complement membrane attack complex on epidermal or vascular cells can cause direct tissue damage and inflammation, e.g., in systemic lupus erythematosus (SLE), phospholipid antibody syndrome, and bullous skin diseases like pemphigoid. By evading complement attack, some microbes like Borrelia spirochetes and staphylococci can persist in the skin and cause prolonged symptoms. In this review, we present the most important skin diseases connected to abnormalities in the function of the complement system. Drugs having an effect on the complement system are also briefly described. On one hand, drugs with free hydroxyl on amino groups (e.g., hydralazine, procainamide) could interact with C4A, C4B, or C3 and cause an SLE-like disease. On the other hand, progress in studies on complement has led to novel anti-complement drugs (recombinant C1-inhibitor and anti-C5 antibody, eculizumab) that could alleviate symptoms in diseases associated with excessive complement activation. The main theme of the manuscript is to show how relevant the complement system is as an immune effector system in contributing to tissue injury and inflammation in a broad range of skin disorders. PMID:25688346

  9. Regulating complement in the kidney: insights from CFHR5 nephropathy

    PubMed Central

    Gale, Daniel P.; Pickering, Matthew C.

    2011-01-01

    Complement factor H related protein 5 (CFHR5) nephropathy is a monogenic disorder of complement regulation that is endemic in Cyprus. The disease is characterised by haematuria, C3 glomerulonephritis and kidney failure. Its identification suggests a role for the CFHR5 protein in the regulation of complement in the kidney. In this review, we discuss how studying CFHR5 nephropathy can contribute to our understanding of the role of complement in kidney diseases such as dense deposit disease, C3 glomerulonephritis and atypical haemolytic uraemic syndrome. PMID:22065842

  10. Crystal structure of a lectin from Canavalia maritima (ConM) in complex with trehalose and maltose reveals relevant mutation in ConA-like lectins.

    PubMed

    Delatorre, Plínio; Rocha, Bruno A M; Gadelha, Carlos A A; Santi-Gadelha, Tatiane; Cajazeiras, Joăo B; Souza, Emmanuel P; Nascimento, Kyria S; Freire, Valder N; Sampaio, Alexandre H; Azevedo, Walter F; Cavada, Benildo S

    2006-06-01

    The crystal structure of Canavalia maritima lectin (ConM) complexed with trehalose and maltose revealed relevant point mutations in ConA-like lectins. ConM with the disaccharides and other ConA-like lectins complexed with carbohydrates demonstrated significant differences in the position of H-bonds. The main difference in the ConM structure is the replacement of Pro202 by Ser202, a residue that promotes the approximation of Tyr12 to the carbohydrate-binding site. The O-6' of the second glucose ring in maltose interacts with Tyr12, while in trehalose the interaction is established by the O-2' and Tyr12, explaining the higher affinity of ConM for disaccharides compared to monosaccharides. PMID:16677825

  11. Interactions between indole-3-acetic acid (IAA) with a lectin from Canavalia maritima seeds reveal a new function for lectins in plant physiology.

    PubMed

    Delatorre, Plinio; Silva-Filho, José Caetano; Rocha, Bruno Anderson Matias; Santi-Gadelha, Tatiane; da Nóbrega, Raphael Batista; Gadelha, Carlos Alberto Almeida; do Nascimento, Kyria Santiago; Nagano, Celso Shiniti; Sampaio, Alexandre Holanda; Cavada, Benildo Sousa

    2013-09-01

    Indole-3-acetic acid (IAA) bound is considered a storage molecule and is inactive. However, some studies have proposed an additional possible regulatory mechanism based on the ability of lectins to form complexes with IAA. We report the first crystal structure of ConM in complex with IAA at 2.15 ? resolution. Based on a tetrameric model of the complex, we hypothesize how the lectin controls the availability of IAA during the early seedling stages, indicating a possible new physiological role for these proteins. A free indole group is also bound to the protein. The ConM interaction with different forms of IAA is a strategy to render the phytohormone unavailable to the cell. Thus, this new physiological role proposed for legume lectins might be a novel mechanism by which IAA levels are decreased in addition to the destruction and formation of new complexes in the later stages of seed germination. PMID:23727478

  12. Fluorescein Isothiocyanate-Labeled Lectin Analysis of the Surface of the Nitrogen-Fixing Bacterium Azospirillum brasilense by Flow Cytometry

    PubMed Central

    Yagoda-Shagam, Janet; Barton, Larry L.; Reed, William P.; Chiovetti, Robert

    1988-01-01

    The cell surface of Azospirillum brasilense was probed by using fluorescein isothiocyanate (FITC)-labeled lectins, with binding determined by fluorescence-activated flow cytometry. Cells from nitrogen-fixing or ammonium-assimilating cultures reacted similarly to FITC-labeled lectins, with lectin binding in the following order: Griffonia simplicifolia II agglutinin > Griffonia simplicifolia I agglutinin > Triticum vulgaris agglutinin > Glycine max agglutinin > Canavalia ensiformis agglutinin > Limax flavus agglutinin > Lotus tetragonolobus agglutinin. The fluorescence intensity of cells labeled with FITC-labeled G. simplicifolia I, C. ensiformis, T. vulgaris, and G. max agglutinins was influenced by lectin concentration. Flow cytometry measurements of lectin binding to cells was consistent with measurements of agglutination resulting from lectin-cell interaction. Capsules surrounding nitrogen-fixing and ammonium-assimilating cells were readily demonstrated by light and transmission electron microscopies. Images PMID:16347693

  13. Detection of cytotoxic activity of lectin on human colon adenocarcinoma (Sw480) and epithelial cervical carcinoma (C33-A).

    PubMed

    Valadez-Vega, Carmen; Alvarez-Manilla, Gerardo; Riverón-Negrete, Leticia; García-Carrancá, Alejandro; Morales-González, José A; Zuńiga-Pérez, Clara; Madrigal-Santillán, Eduardo; Esquivel-Soto, Jaime; Esquivel-Chirino, Cesar; Villagómez-Ibarra, Roberto; Bautista, Mirandeli; Morales-González, Angel

    2011-01-01

    Lectins comprise a heterogeneous class of proteins that recognize the carbohydrate moieties of glycoconjugates with high specificity. Numerous studies have shown that lectins are capable of recognizing specific carbohydrate moieties displayed by malignant cells or tissues. The present work was performed to investigate the effects of tepary bean (Phaseolus acutifolius) lectins on proliferation, colony formation, and alteration of DNA synthesis of human malignant cells. Tepary bean lectin showed dose dependent  effects on the inhibition of viability as well as on colony formation in two human malignant cells lines (C33-A, Sw480); By contrast, tepary bean lectin only showed significant effects on DNA synthesis on Sw480 cells. Our results provide evidence of the anti- proliferative and cytotoxic effects of the tepary bean lectins on C33-A and Sw480 cells lines. PMID:21368722

  14. Potential usage for in vivo lectin screening in live animals utilizing cell surface mimetic glyco-nanoparticles, phosphorylcholine-coated quantum dots (PC-QDs).

    PubMed

    Amano, Maho; Hinou, Hiroshi; Miyoshi, Risho; Nishimura, Shin-Ichiro

    2014-01-01

    Utilizing glycosylated derivatives as a tag, we are able to explore novel counter-receptor of endogenous lectins or lectin-like molecules in vivo. We have established the standardized methodology including preparation of glycosylated derivatives and construction of a platform for tracing the molecules in vivo at first. Combined use of an aminooxy-terminated thiol derivative and a phosphorylcholine (PC) derivative provides quantum dots (QDs) with novel functions for the chemical ligation of ketone-functionalized compounds and the prevention of nonspecific protein adsorption concurrently. In order to track the derivatives in vivo, near-infrared (NIR) fluorescence imaging of QDs displaying various simple sugars (glyco-PC-QDs) after administration into the tail vein of the mouse can be performed. It has revealed that distinct long-term delocalization over 2 h can be observed depending on the species of glycans ligated to PC-QDs at least in the liver. Until today we have performed live animal imaging utilizing various kinds of sialyl glyco-PC-QDs. They are still retained stably in whole body after 2 h while they showed significantly different in vivo dynamics in the tissue distribution, suggesting that structure/sequence of the neighboring sugar residues in the individual sialyl oligosaccharides might influence the final organ-specific distribution, which should be equivalent to the distribution of sialic acid-recognizing lectins. Here we describe a standardized protocol using ligand-displayed PC-QDs for live cell/animal imaging by versatile NIR fluorescence photometry without influence of size-dependent accumulation/excretion pathway for nanoparticles (e.g., viruses)>10 nm in hydrodynamic diameter by the liver. PMID:25117250

  15. [A new mannose-specific lectin from daylily (Hemerocallis fulva L.) rhizome: purification and properties].

    PubMed

    Antoniuk, V O; Panchak, L V; Starykovych, M O; Sto?ka, R S

    2013-01-01

    A new lectin was purified from the daylily (Hemerocallis fulva L.) with the yield of approximately 10 mg per kg of fresh plant rhizome. The purification procedure was based on application of the affinity chromathography on the column with yeast mannan and the ion-exchange chromatography on the column with DEAE-Toyopearl. The lectin possessed low affinity for alpha-methyl-D-mannopyranoside, D-fructose, D-turanose and 2-acetamido-D-galactopyranose and hight affinity for the yeast mannan. The lectin bound with greatly less affinity for the mannose-containig glycoproteins, such as ovoalbumin, ovomucoid and horseradish peroxidase. According to the results of electrophoresis in 20% DSNa-PAGE, the lectin consists of subunits of 12 kDa molecular weight. According to the results of gel-chromatography on the Toyopearl HW-55, the lectin's molecular weight is 48 kDa. It agglutinated rabbit erythrocytes very well, while rat and guinea-pig erythrocytes were agglutinated worse, and human erythrocytes were not agglutinated at all. Lectin's dialysis against 1% EDTA or heating to 60 degrees C for 60 min did not stop its hemagglutinating activity. PMID:23808307

  16. Density Variant Glycan Microarray for Evaluating Cross-Linking of Mucin-like Glycoconjugates by Lectins

    PubMed Central

    2012-01-01

    Interactions of mucin glycoproteins with cognate receptors are dictated by the structures and spatial organization of glycans that decorate the mucin polypeptide backbone. The glycan-binding proteins, or lectins, that interact with mucins are often oligomeric receptors with multiple ligand binding domains. In this work, we employed a microarray platform comprising synthetic glycopolymers that emulate natural mucins arrayed at different surface densities to evaluate how glycan valency and spatial separation affect the preferential binding mode of a particular lectin. We evaluated a panel of four lectins (Soybean agglutinin (SBA), Wisteria floribunda lectin (WFL), Vicia villosa-B-4 agglutinin (VVA), and Helix pomatia agglutin (HPA)) with specificity for ?-N-acetylgalactosamine (?-GalNAc), an epitope displayed on mucins overexpressed in many adenocarcinomas. While these lectins possess the ability to agglutinate A1-blood cells carrying the ?-GalNAc epitope and cross-link low valency glycoconjugates, only SBA showed a tendency to form intermolecular cross-links among the arrayed polyvalent mucin mimetics. These results suggest that glycopolymer microarrays can reveal discrete higher-order binding preferences beyond the recognition of individual glycan epitopes. Our findings indicate that glycan valency can set thresholds for cross-linking by lectins. More broadly, well-defined synthetic glycopolymers enable the integration of glycoconjugate structural and spatial diversity in a single microarray screening platform. PMID:22967056

  17. Genomic cloning and characterization of a novel lectin gene from Zantedeschia aethiopica.

    PubMed

    Chen, Zhonghai; Sun, Xiaofen; Tang, Kexuan

    2004-06-01

    A new lectin gene was isolated by using genomic walker technology and revealed to encode a mannose-binding lectin. Analysis of a 2233 bp segment revealed a gene including a 1169 bp 5' flanking region, a 417 bp open reading frame (ORF) and a 649 bp 3' flanking region. There are two putative TATA boxes and eight possible CAAT boxes lie in the 5' flanking region. The ORF encodes a 15.1 kDa precursor, which contains a 24-amino acid signal peptide. One possible polyadenylation signal is found in the 3'-flanking region. No intron was detected within the region of genomic sequence corresponding to zaa (Zantedeschia aethiopica agglutinin) full-length cDNA, which is typical of other mannose-binding lectin gene that have been reported. The deduced amino acid sequence of the lectin gene coding region shares 49-54% homology with other known lectins. The cloning of this new lectin gene will allow us to further study its structure, expression and regulation mechanisms. PMID:16209131

  18. Comparative analysis of carbohydrate binding properties of Sambucus nigra lectins and ribosome-inactivating proteins.

    PubMed

    Shang, Chenjing; Van Damme, Els J M

    2014-07-01

    In the past three decades a lot of research has been done on the extended family of carbohydrate-binding proteins from Sambucus nigra, including several so-called type 2 RIPs as well as hololectins. Although all these proteins have been studied for their carbohydrate-binding properties using hapten inhibition assays, detailed carbohydrate specificity studies have only been performed for a few Sambucus proteins. In particular SNA-I, has been studied extensively. Because of its unique binding characteristics this lectin was developed as an important tool in glycoconjugate research to detect sialic acid containing glycoconjugates. At present much less information is available with respect to the detailed carbohydrate binding specificity of other S. nigra lectins and RIPs, and as a consequence their applications remain limited. In this paper we report a comparative analysis of several lectins from S. nigra using the glycan microarray technology. Ultimately a better understanding of the ligands for each lectin can contribute to new/more applications for these lectins in glycoconjugate research. Furthermore, the data from glycan microarray analyses combined with the previously obtained sequence information can help to explain how evolution within a single lectin family eventually yielded a set of carbohydrate-binding proteins with a very broad specificity range. PMID:24853865

  19. Isolation and characterization of a novel lectin from the mushroom Armillaria luteo-virens

    SciTech Connect

    Feng, K.; Liu, Q.H.; Ng, T.B.; Liu, H.Z.; Li, J.Q.; Chen, G.; Sheng, H.Y.; Xie, Z.L.; Wang, H.X. . E-mail: hxwang@cau.edu.cn

    2006-07-14

    From the dried fruiting bodies of the mushroom Armillaria luteo-virens, a dimeric lectin with a molecular mass of 29.4 kDa has been isolated. The purification procedure involved (NH{sub 4}){sub 2}SO{sub 4} precipitation, ion exchange chromatography on DEAE-cellulose, CM-cellulose, and Q-Sepharose, and gel filtration by fast protein liquid chromatography on Superdex 75. The hemagglutinating activity of the lectin could not be inhibited by simple sugars but was inhibited by the polysaccharide inulin. The activity was stable up to 70 {sup o}C but was acid- and alkali-labile. Salts including FeCl{sub 3}, AlCl{sub 3}, and ZnCl{sub 2} inhibited the activity whereas MgCl{sub 2}, MnCl{sub 2}, and CaCl{sub 2} did not. The lectin stimulated mitogenic response of mouse splenocytes with the maximal response achieved by 1 {mu}M lectin. Proliferation of tumor cells including MBL2 cells, HeLa cells, and L1210 cells was inhibited by the lectin with an IC{sub 5} of 2.5, 5, and 10 {mu}M, respectively. However, proliferation of HepG2 cells was not affected. The novel aspects of the isolated lectin include a novel N-terminal sequence, fair thermostability, acid stability, and alkali stability, together with potent mitogenic activity toward spleen cells and antiproliferative activity toward tumor cells.

  20. An N-acetylglucosamine oligomer binding agglutinin (lectin) from ripe Cyphomandra betacea Sendt. fruits.

    PubMed

    Sampietro, A R.; Isla, M I.; Quiroga, E N.; Vattuone, M A.

    2001-03-01

    A new agglutinin (lectin), called CBL3, was purified from the juice of ripe Cyphomandra betacea Sendt. fruits until electrophoretically pure to homogeneity. The lectin is a homodimer of M(r)=50800 with subunits of 26200 bound by disulfide linkages with a pI of 4.9. The agglutinating capacity of the lectin is only inhibited by oligomers of N-acetylglucosamine in the following order of potency: tetrasaccharide>trisaccharide>disaccharide. CBL3 is not inhibited by N-acetylglucosamine, the same as all known lectins of the Solanaceae family. The human blood group recognition is non-specific. The lectin is a glycoprotein with 13.6% (w/w) of carbohydrates. The agglutinating activity is not affected by EDTA nor by cations. Mitogenic activity was not detected. Heat and pH stability, amino acid composition, N-terminal amino acid sequence and immunological properties show substantial differences to the reported lectins isolated from the Solanaceae family. PMID:11448741

  1. Purification and applications of a lectin from the mushroom Gymnopilus spectabilis.

    PubMed

    Alborés, Silvana; Mora, Paola; Bustamante, María José; Cerdeiras, María Pía; Franco Fraguas, Laura

    2014-02-01

    A lectin was isolated from fruiting bodies of the mushroom Gymnopilus spectabilis (GSL) by ionic exchange chromatography. The lectin agglutinates mouse red cells exhibiting broad specificity towards several monosaccharides including the N-acetylneuraminic acid. Agglutination was also inhibited by the glycoproteins: fetuin, lactoferrin, and recombinant erythropoietin. GSL is a glycoprotein possessing 16 % of carbohydrates; the SDS-PAGE showed two bands with molecular mass of 52.1 and 64.4 kDa. Isoelectric focusing displayed microheterogeneity, with two bands at pIs 5.1 and 5.3. The lectin was stable between pH 2 and pH 8 while at pH 10, the agglutination decayed to 50 % of initial activity. Incubation at 40 and 80 °C led to 50 and 100 % loss in activity of the lectin, respectively. Synthesized GSL-Sepharose interacts with serum pregnant mare gonadotropin, and at least two subpopulations of this glycoprotein were separated. There was no interaction between transferrin and soluble GSL while a partial recognition was achieved with GSL-Sepharose. The terminal sialic acid seems to play an active role in modifying the interaction with GSL, depending if the lectin is in a soluble or immobilized form. The purified lectin inhibited in vitro the growth of Staphylococcus aureus and Aspergillus niger. PMID:24338208

  2. Lysis of fresh human solid tumors by autologous lymphocytes activated in vitro with lectins

    SciTech Connect

    Mazumder, A.; Grimm, E.A.; Zhang, H.Z.; Rosenberg, S.A.

    1982-03-01

    Human peripheral blood lymphocytes (PBL), obtained from patients with a variety of cancers, were incubated in vitro with phytohemagglutinin, concanavalin A, and crude or lectin-free T-cell growth factors. The lectin-activated PBL of nine patients were capable of lysing fresh autologous tumor during a 4-hr 51Cr release assay. Multiple metastases from the same patient were equivalently lysed by these activated autologous PBL. No lysis of fresh PBL or lectin-induced lymphoblast cell targets was seen, although tumor, PBL, and lymphoblast cells were shown to be equally lysable using allosensitized cells. The activated cells could be expanded without loss of cytotoxicity in crude or lectin-free T-cell growth factors. The generation of cells lytic to fresh autologous tumor was dependent on the presence of adherent cells, although the lytic cell itself was not adherent. Proliferation was not involved in the induction of lytic cells since equal lysis was induced in irradiated and nonirradiated lymphocytes. Lectin was not required in the lytic assay, and the addition of alpha-methyl-D-mannoside to concanavalin A-activated lymphoid cells did not increase the lysis of fresh tumor cells. Activation by lectin for 3 days appears to be an efficient and convenient method for generating human cells lytic to fresh autologous tumor. These lytic cells may be of value for studies of the cell-mediated lysis of human tumor and possibly for tumor immunotherapy as well.

  3. Expression, purification, cocrystallization and preliminary crystallographic analysis of sucrose octasulfate/human complement regulator factor H SCRs 6–8

    SciTech Connect

    Prosser, Beverly E.; Johnson, Steven; Roversi, Pietro; Clark, Simon J.; Tarelli, Edward; Sim, Robert B.; Day, Antony J.; Lea, Susan M.

    2007-06-01

    The crystallization of human complement regulator FH-678{sub 402H} with a glycosaminoglycan analogue is described. Human plasma protein complement factor H (FH) is an inhibitor of the spontaneously activated alternative complement pathway. An allotypic variant of FH, 402His, has been associated with age-related macular degeneration, the leading cause of blindness in the elderly. Crystals of FH domains 6–8 (FH678) containing 402His have been grown in the presence of a polyanionic sucrose octasulfate ligand (an analogue of the natural glycosaminoglycan ligands of FH) using both native and selenomethionine-derivatized protein. Native data sets diffracting to 2.3 Ĺ and SeMet data sets of up to 2.8 Ĺ resolution have been collected. An anomalous difference Patterson map reveals self- and cross-peaks from two incorporated Se atoms. The corresponding selenium substructure has been solved.

  4. The fucosyl specific lectins of Ulex europaeus and Sarothamnus scoparius. Biochemical characteristics and binding properties to human B-lymphocytes.

    PubMed

    Gürtler, L G

    1978-12-18

    From the seeds of the gorse, Ulex europaeus and of the broom, Sarothamnus scoparius L-fucosyl-specific lectins were isolated by affinity chromatography on L-fucosyl-epoxy-Sepharose. The lectins showed similarities in their molecular weights, amino acid composition, carbohydrate content and in the finger-prints of their tryptic peptides. The fluorescein-labeled lectins of both seeds attached especially to the plasma membranes of human B-lymphocytes. PMID:310317

  5. Minor Role of Plasminogen in Complement Activation on Cell Surfaces

    PubMed Central

    Hyvärinen, Satu; Jokiranta, T. Sakari

    2015-01-01

    Atypical hemolytic uremic syndrome (aHUS) is a rare, but severe thrombotic microangiopathy. In roughly two thirds of the patients, mutations in complement genes lead to uncontrolled activation of the complement system against self cells. Recently, aHUS patients were described with deficiency of the fibrinolytic protein plasminogen. This zymogen and its protease form plasmin have both been shown to interact with complement proteins in the fluid phase. In this work we studied the potential of plasminogen to restrict complement propagation. In hemolytic assays, plasminogen inhibited complement activation, but only when it had been exogenously activated to plasmin and when it was used at disproportionately high concentrations compared to serum. Addition of only the zymogen plasminogen into serum did not hinder complement-mediated lysis of erythrocytes. Plasminogen could not restrict deposition of complement activation products on endothelial cells either, as was shown with flow cytometry. With platelets, a very weak inhibitory effect on deposition of C3 fragments was observed, but it was considered too weak to be significant for disease pathogenesis. Thus it was concluded that plasminogen is not an important regulator of complement on self cells. Instead, addition of plasminogen was shown to clearly hinder platelet aggregation in serum. This was attributed to plasmin causing disintegration of formed platelet aggregates. We propose that reduced proteolytic activity of plasmin on structures of growing thrombi, rather than on complement activation fragments, explains the association of plasminogen deficiency with aHUS. This adds to the emerging view that factors unrelated to the complement system can also be central to aHUS pathogenesis and suggests that future research on the mechanism of the disease should expand beyond complement dysregulation. PMID:26637181

  6. Complementing thermosteric sea level rise estimates

    NASA Astrophysics Data System (ADS)

    Lorbacher, K.; Nauels, A.; Meinshausen, M.

    2015-09-01

    Thermal expansion of seawater has been one of the most important contributors to global sea level rise (SLR) over the past 100 years. Yet, observational estimates of this volumetric response of the world's oceans to temperature changes are sparse and mostly limited to the ocean's upper 700 m. Furthermore, only a part of the available climate model data is sufficiently diagnosed to complete our quantitative understanding of thermosteric SLR (thSLR). Here, we extend the available set of thSLR diagnostics from the Coupled Model Intercomparison Project Phase 5 (CMIP5), analyze those model results in order to complement upper-ocean observations and enable the development of surrogate techniques to project thSLR using vertical temperature profile and ocean heat uptake time series. Specifically, based on CMIP5 temperature and salinity data, we provide a compilation of thermal expansion time series that comprise 30 % more simulations than currently published within CMIP5. We find that 21st century thSLR estimates derived solely based on observational estimates from the upper 700 m (2000 m) would have to be multiplied by a factor of 1.39 (1.17) with 90 % uncertainty ranges of 1.24 to 1.58 (1.05 to 1.31) in order to account for thSLR contributions from deeper levels. Half (50 %) of the multi-model total expansion originates from depths below 490 ± 90 m, with the range indicating scenario-to-scenario variations. To support the development of surrogate methods to project thermal expansion, we calibrate two simplified parameterizations against CMIP5 estimates of thSLR: one parameterization is suitable for scenarios where hemispheric ocean temperature profiles are available, the other, where only the total ocean heat uptake is known (goodness of fit: ±5 and ±9 %, respectively).

  7. Assembly, organization and regulation of cell-surface receptors by lectin-glycan complexes.

    PubMed

    Elola, María T; Blidner, Ada G; Ferragut, Fátima; Bracalente, Candelaria; Rabinovich, Gabriel A

    2015-07-01

    Galectins are a family of ?-galactoside-binding lectins carrying at least one consensus sequence in the carbohydrate-recognition domain. Properties of glycosylated ligands, such as N- and O-glycan branching, LacNAc (N-acetyl-lactosamine) content and the balance of ?2,3- and ?2,6-linked sialic acid dramatically influence galectin binding to a preferential set of counter-receptors. The presentation of specific glycans in galectin-binding partners is also critical, as proper orientation and clustering of oligosaccharide ligands on multiple carbohydrate side chains increase the binding avidity of galectins for particular glycosylated receptors. When galectins are released from the cells, they typically concentrate on the cell surface and the local matrix, raising their local concentration. Thus galectins can form their own multimers in the extracellular milieu, which in turn cross-link glycoconjugates on the cell surface generating galectin-glycan complexes that modulate intracellular signalling pathways, thus regulating cellular processes such as apoptosis, proliferation, migration and angiogenesis. Subtle changes in receptor expression, rates of protein synthesis, activities of Golgi enzymes, metabolite concentrations supporting glycan biosynthesis, density of glycans, strength of protein-protein interactions at the plasma membrane and stoichiometry may modify galectin-glycan complexes. Although galectins are key contributors to the formation of these extended glycan complexes leading to promotion of receptor segregation/clustering, and inhibition of receptor internalization by surface retention, when these complexes are disrupted, some galectins, particularly galectin-3 and -4, showed the ability to drive clathrin-independent mechanisms of endocytosis. In the present review, we summarize the data available on the assembly, hierarchical organization and regulation of conspicuous galectin-glycan complexes, and their implications in health and disease. PMID:26173257

  8. Mechanisms involved in Korean mistletoe lectin-induced apoptosis of cancer cells

    PubMed Central

    Khil, Lee-Yong; Kim, Wi; Lyu, Suyun; Park, Won Bong; Yoon, Ji-Won; Jun, Hee-Sook

    2007-01-01

    AIM: To investigate the anti-cancer mechanisms of Korean mistletoe lectin (Viscum album coloratum agglutinin, VCA) using a human colon cancer cell line (COLO). METHODS: Cytotoxic effects of VCA on COLO cells were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in vitro and tumor-killing effects in vivo. To study the mechanisms involved, the expression of various pro-caspases, anti-apoptotic proteins, and death receptors was determined by western blot. To determine which death receptor is involved in VCA-induced apoptosis of COLO cells, cytotoxicity was examined by MTT assay after treatment with agonists or antagonists of death receptors. RESULTS: VCA killed COLO cells in a time- and dose-dependent manner and induced complete regression of tumors in nude mice transplanted with COLO cells. Treatment of COLO cells with VCA activated caspase-2, -3, -8, and -9 and decreased expression of anti-apoptotic molecules including receptor interacting protein, nuclear factor-?B, X-linked inhibitor of apoptosis protein, and Akt/protein kinase B. We then examined the involvement of death receptors in VCA-induced apoptosis. Only tumor necrosis factor receptor 1, among the death receptors examined, was involved in apoptosis of COLO cells, evidenced by inhibition of VCA-induced apoptosis and decreased activation of caspases, particularly caspase-8, by tumor necrosis factor receptor 1 antagonizing antibody. CONCLUSION: VCA-induced apoptotic COLO cell death is due to the activation of caspases and inhibition of anti-apoptotic proteins, in part through the tumor necrosis factor receptor 1 signaling pathway. PMID:17569116

  9. Lipopolysaccharide-binding lectin from the horseshoe crab, Limulus polyphemus, with specificity for 2-keto-3-deoxyoctonate (KDO).

    PubMed

    Rostam-Abadi, H; Pistole, T G

    1982-01-01

    A lipopolysaccharide (LPS)-binding lectin was recovered from the serum of Limulus polyphemus by ion-exchange chromatography. Electrophoretic analysis of this lectin preparation revealed three poorly migrating bands. When whole serum was incubated with glycolipid obtained from the Rc mutant of Salmonella minnesota prior to electrophoresis, bands corresponding to those seen in the partially purified lectin were missing, suggesting that the recovered material was composed of isolectins. Qualitative precipitin tests revealed no reactivity of this purified lectin with lipid A fractions or with LPS devoid of 2-keto-3-deoxyoctonate (KDO). The agglutination of chicken erythrocytes by this lectin was inhibited by both N-acetyl-neuraminic acid and KDO. Erythrocytes complexed with glycolipid from the Re mutant of S. minnesota were strongly agglutinated by this lectin. We conclude that this LPS-binding lectin is specific for the KDO portion of the molecule and that it is identical to the previously described sialic acid-binding lectin from L. polyphemus. This lectin may play a role in the host defense mechanisms of Limulus. PMID:7047248

  10. Crystallization and preliminary X-ray diffraction analysis of HML, a lectin from the red marine alga Hypnea musciformis

    SciTech Connect

    Nagano, Celso S.; Gallego del Sol, Francisca; Cavada, Benildo S.; Nascimento, Kyria Santiago Do; Nunes, Eudismar Vale; Sampaio, Alexandre H.; Calvete, Juan J.

    2005-11-01

    The crystallization and preliminary X-ray diffraction analysis of a red marine alga lectin isolated from H. musciformis is reported. HML, a lectin from the red marine alga Hypnea musciformis, defines a novel lectin family. Orthorhombic crystals of HML belonging to space group P2{sub 1}2{sub 1}2{sub 1} grew within three weeks at 293 K using the hanging-drop vapour-diffusion method. A complete data set was collected at 2.4 Ĺ resolution. HML is the first marine alga lectin to be crystallized.

  11. Activation of dendritic cells by the Gal-lectin of Entamoeba histolytica drives Th1 responses in vitro and in vivo.

    PubMed

    Ivory, Catherine P A; Chadee, Kris

    2007-02-01

    Amebiasis is a human disease caused by the protozoan intestinal parasite Entamoeba histolytica. Vaccine development has focused on the parasite's surface galactose-N-acetyl-D-galactosamine inhibitable lectin (Gal-lectin) as a protective antigen. The Gal-lectin is immunogenic and has been shown to induce Th1 cytokines in vitro and in vivo. The immunological basis of the protective immune response elicited by the Gal-lectin is unknown. In this study, we investigated the response of BALB/c bone marrow-derived DC to E. histolytica Gal-lectin. Incubation of immature DC with Gal-lectin resulted in activation and maturation after 24 h. FACS analysis demonstrated an up-regulation of DC maturation markers CD80, CD86, CD40 and MHC class II upon exposure to Gal-lectin. The Gal-lectin also induced DC production of IL-12, indicating a Th1 response. Gal-lectin-activated DC were able to stimulate T cell proliferation in an allogeneic mixed leukocyte reaction and adoptive transfer of Gal-lectin-treated DC into naďve mice resulted in IFN-gamma-producing Gal-lectin-sensitized T cells. The activation of DC by Gal-lectin was mediated by MAPK and NF-kappaB. These findings indicate that E. histolytica Gal-lectin is a potent vaccine antigen capable of directly initiating DC maturation and activation characterized by Th1 cytokine production. PMID:17219364

  12. Complement evasion by Bordetella pertussis: implications for improving current vaccines.

    PubMed

    Jongerius, Ilse; Schuijt, Tim J; Mooi, Frits R; Pinelli, Elena

    2015-04-01

    Bordetella pertussis causes whooping cough or pertussis, a highly contagious disease of the respiratory tract. Despite high vaccination coverage, reported cases of pertussis are rising worldwide and it has become clear that the current vaccines must be improved. In addition to the well-known protective role of antibodies and T cells during B. pertussis infection, innate immune responses such as the complement system play an essential role in B. pertussis killing. In order to evade this complement activation and colonize the human host, B. pertussis expresses several molecules that inhibit complement activation. Interestingly, one of the known complement evasion proteins, autotransporter Vag8, is highly expressed in the recently emerged B. pertussis isolates. Here, we describe the current knowledge on how B. pertussis evades complement-mediated killing. In addition, we compare this to complement evasion strategies used by other bacterial species. Finally, we discuss the consequences of complement evasion by B. pertussis on adaptive immunity and how identification of the bacterial molecules and the mechanisms involved in complement evasion might help improve pertussis vaccines. PMID:25686752

  13. Humoral response to herpes simplex virus is complement-dependent

    E-print Network

    Knipe, David M.

    immunity. Recent studies have revealed that complement links innate and adaptive immunity via complement is important not only in the effector function of innate immunity but also in the stimulation of memory B cell responses to viral-infected cell antigens in both blood and peripheral tissues. Innate immune mechanisms

  14. Physicochemical signatures of nanoparticle-dependent complement activation

    NASA Astrophysics Data System (ADS)

    Thomas, Dennis G.; Chikkagoudar, Satish; Heredia-Langner, Alejandro; Tardiff, Mark F.; Xu, Zhixiang; Hourcade, Dennis E.; Pham, Christine T. N.; Lanza, Gregory M.; Weinberger, Kilian Q.; Baker, Nathan A.

    2014-01-01

    Nanoparticles are potentially powerful therapeutic tools that have the capacity to target drug payloads and imaging agents. However, some nanoparticles can activate complement, a branch of the innate immune system, and cause adverse side-effects. Recently, we employed an in vitro hemolysis assay to measure the serum complement activity of perfluorocarbon nanoparticles that differed by size, surface charge, and surface chemistry, quantifying the nanoparticle-dependent complement activity using a metric called Residual Hemolytic Activity (RHA). In the present work, we have used a decision tree learning algorithm to derive the rules for estimating nanoparticle-dependent complement response based on the data generated from the hemolytic assay studies. Our results indicate that physicochemical properties of nanoparticles, namely, size, polydispersity index, zeta potential, and mole percentage of the active surface ligand of a nanoparticle, can serve as good descriptors for prediction of nanoparticle-dependent complement activation in the decision tree modeling framework.

  15. Physicochemical signatures of nanoparticle-dependent complement activation

    PubMed Central

    Thomas, Dennis G.; Chikkagoudar, Satish; Heredia-Langer, Alejandro; Tardiff, Mark F.; Xu, Zhixiang; Hourcade, Dennis E.; Pham, Christine T. N.; Lanza, Gregory M.; Weinberger, Kilian Q.; Baker, Nathan A.

    2014-01-01

    Nanoparticles are potentially powerful therapeutic tools that have the capacity to target drug payloads and imaging agents. However, some nanoparticles can activate complement, a branch of the innate immune system, and cause adverse side-effects. Recently, we employed an in vitro hemolysis assay to measure the serum complement activity of perfluorocarbon nanoparticles that differed by size, surface charge, and surface chemistry, quantifying the nanoparticle-dependent complement activity using a metric called Residual Hemolytic Activity (RHA). In the present work, we have used a decision tree learning algorithm to derive the rules for estimating nanoparticle-dependent complement response based on the data generated from the hemolytic assay studies. Our results indicate that physicochemical properties of nanoparticles, namely, size, polydispersity index, zeta potential, and mole percentage of the active surface ligand of a nanoparticle, can serve as good descriptors for prediction of nanoparticle-dependent complement activation in the decision tree modeling framework. PMID:25254068

  16. [Renal risks of dietary complements: a forgotten cause].

    PubMed

    Dori, Olympia; Humbert, Antoine; Burnier, Michel; Teta, Daniel

    2014-02-26

    The use of dietary complements like vitamins, minerals, trace elements, proteins, aminoacids and plant-derived agents is prevalent in the general population, in order to promote health and treat diseases. Dietary complements are considered as safe natural products and are easily available without prescription. However, these can lead to severe renal toxicity, especially in cases of unknown pre-existing chronic kidney disease (CKD). In particular, Chinese herbs including aristolochic acid, high doses of vitamine C, creatine and protein complements may lead to acute and chronic renal failure, sometimes irreversible. Dietary complement toxicity should be suspected in any case of unexplained renal impairement. In the case of pre-existing CKD, the use of potentially nephrotoxic dietary complements should be screened for. PMID:24665660

  17. [The detection of activity of components and factors of complement according its effect on infusorians].

    PubMed

    Kuleshina, O N; Kozlov, L V

    2015-01-01

    The article considers the developed techniques of detection of functional activity of components C1, C2, C3, C4 and membrane attacking complex of classical pathway and also factors B and D of alternative pathway of human complement using automated device measurement of immobilizing effect on infusorians Tetrahymena pyriformis. The techniques are based on application of artificially produced reagents containing all necessary components of compliment besides testing one. The mathematical mode of activities calculation is developed. The linear dependency of velocity of infusorians immobilizing from functional activities of testing component. The relevance of techniques is demonstrated by correlation of results derived using the proposed mode with the developed earlier hemolytic mode. PMID:25874307

  18. Pea lectin receptor-like kinase functions in salinity adaptation without yield penalty, by alleviating osmotic and ionic stresses and upregulating stress-responsive genes.

    PubMed

    Vaid, Neha; Pandey, Prashant; Srivastava, Vineet Kumar; Tuteja, Narendra

    2015-05-01

    Lectin receptor-like kinases (LecRLKs) are members of RLK family composed of lectin-like extracellular recognition domain, transmembrane domain and cytoplasmic kinase domain. LecRLKs are plasma membrane proteins believed to be involved in signal transduction. However, most of the members of the protein family even in plants have not been functionally well characterized. Herein, we show that Pisum sativum LecRLK (PsLecRLK) localized in plasma membrane systems and/or other regions of the cell and its transcript upregulated under salinity stress. Overexpression of PsLecRLK in transgenic tobacco plants confers salinity stress tolerance by alleviating both the ionic as well the osmotic component of salinity stress. The transgenic plants show better tissue compartmentalization of Na(+) and higher ROS scavenging activity which probably results in lower membrane damage, improved growth and yield maintenance even under salinity stress. Also, expression of several genes involved in cellular homeostasis is perturbed by PsLecRLK overexpression. Alleviation of osmotic and ionic components of salinity stress along with reduced oxidative damage and upregulation of stress-responsive genes in transgenic plants under salinity stress conditions could be possible mechanism facilitating enhanced stress tolerance. This study presents PsLecRLK as a promising candidate for crop improvement and also opens up new avenue to investigate its signalling pathway. PMID:25863480

  19. Potassium humate inhibits complement activation and the production of inflammatory cytokines in vitro

    SciTech Connect

    van Rensburg, C.E.J.; Naude, P.J.

    2009-08-15

    The effects of brown coal derived potassium humate on lymphocyte proliferation, cytokine production and complement activation were investigated in vitro. Potassium humate increased lymphocyte proliferation of phytohaemaglutinin A (PHA) and pokeweed mitogen (PWM) stimulated mononuclear lymphocytes (MNL) in vitro from concentrations of 20 to 80 {mu} g/ml, in a dose dependant manner. On the other hand potassium humate, at 40 {mu} g/ml, significantly inhibited the release of TNF-alpha, IL-1 beta, IL-6 and IL-10 by PHA stimulated MNL. Regarding complement activation it was found that potassium humate inhibits the activation of both the alternative and classical pathways without affecting the stability of the red blood cell membranes. These results indicate that the anti-inflammatory potential of potassium humate could be partially due to the inhibition of pro-inflammatory cytokines responsible for the initiation of these reactions as well as inhibition of complement activation. The increased lymphocyte proliferation observed, might be due to increased IL-2 production as previously been documented.

  20. Roles of Complement C1q in Pneumococcus-Host Interactions.

    PubMed

    Agarwal, Vaibhav; Blom, Anna M

    2015-01-01

    The fight between a human host and a bacterial pathogen is highly complicated; each party tries to outshine the other in the race for survival. In humans, the innate immune system-in particular the complement system-functions as the first line of defence against invading pathogens. During the course of evolution, however, pathogens, in order to survive and perpetuate within a host, developed multiple strategies to counteract the host complement system and to colonize. One such pathogen is Streptococcus pneumoniae (pneumococcus), a gram-positive bacterial pathogen often commensal in the human respiratory tract. Depending on the host's susceptibility, pneumococci can transform into an infectious agent, disseminating within the human host and causing mild to life-threatening diseases. This transition from commensal to infectious agent is a highly complex process, and understanding of this mechanism is essential in controlling the pathogenicity of pneumococci. Using its intricate arsenal of weapons, such as surface-presenting adhesins as well as recruitment of host factor, pneumococci successfully colonize the host, a prerequisite for establishing infection. This review describes C1q, the first subunit of the classical complement pathway, and its role in pneumococcus-host interactions, whereby pneumococci exploit C1q as a molecular bridge facilitating host cellular adherence and invasion, a function not akin to the role of C1q in the defence mechanism. PMID:26559226

  1. Amastigotes of Trypanosoma cruzi escape destruction by the terminal complement components

    SciTech Connect

    Iida, K.; Whitlow, M.B.; Nussenzweig, V.

    1989-03-01

    We studied the effect of complement on two life cycle stages of the protozoan parasite Trypanosoma cruzi: epimastigotes, found in the insect vector, and amastigotes, found in the mammalian host. We found that while both stages activate vigorously the alternative pathway, only epimastigotes are destroyed. The amounts of C3 and C5b-7 deposited on the amastigotes were similar to those bound to the much larger epimastigotes. Binding of C9 to amastigotes was four to six times less than binding to epimastigotes, resulting in a lower C9/C5b-7 ratio. Although a fairly large amount of C9 bound stably to amastigotes, no functional channels were formed as measured by release of incorporated /sup 86/Rb. The bound C9 had the characteristic properties of poly-C9, that is, it expressed a neo-antigen unique to poly-C9, and migrated in SDS-PAGE with an apparent Mr greater than 10(5). The poly-C9 was removed from the surface of amastigotes by treatment with trypsin, indicating that it was not inserted in the lipid bilayer. Modification of amastigote surface by pronase treatment rendered the parasites susceptible to complement attack. These results suggest that amastigotes have a surface protein that binds to the C5b-9 complex and inhibits membrane insertion, thus protecting the parasites from complement-mediated lysis.

  2. Visualization of melanoma tumor with lectin-conjugated rare-earth doped fluoride nanocrystals

    PubMed Central

    Dumych, Tetiana; Lutsyk, Maxym; Banski, Mateusz; Yashchenko, Antonina; Sojka, Bartlomiej; Horbay, Rostyslav; Lutsyk, Alexander; Stoika, Rostyslav; Misiewicz, Jan; Podhorodecki, Artur; Bilyy, Rostyslav

    2014-01-01

    Aim To develop specific fluorescent markers for melanoma tumor visualization, which would provide high selectivity and reversible binding pattern, by the use of carbohydrate-recognizing proteins, lectins, combined with the physical ability for imaging deep in the living tissues by utilizing red and near infrared fluorescent properties of specific rare-earth doped nanocrystals (NC). Methods B10F16 melanoma cells were inoculated to C57BL/6 mice for inducing experimental melanoma tumor. Tumors were removed and analyzed by lectin-histochemistry using LABA, PFA, PNA, HPA, SNA, GNA, and NPL lectins and stained with hematoxylin and eosin. NPL lectin was conjugated to fluorescent NaGdF4:Eu3+-COOH nanoparticles (5 nm) via zero length cross-linking reaction, and the conjugates were purified from unbound substances and then used for further visualization of histological samples. Fluorescent microscopy was used to visualize NPL-NaGdF4:Eu3+ with the fluorescent emission at 600-720 nm range. Results NPL lectin selectively recognized regions of undifferentiated melanoblasts surrounding neoangiogenic foci inside melanoma tumor, PNA lectin recognized differentiated melanoblasts, and LCA and WGA were bound to tumor stroma regions. NPL-NaGdF4:Eu3+ conjugated NC were efficiently detecting newly formed regions of melanoma tumor, confirmed by fluorescent microscopy in visible and near infrared mode. These conjugates possessed high photostability and were compatible with convenient xylene-based mounting systems and preserved intensive fluorescent signal at samples storage for at least 6 months. Conclusion NPL lectin-NaGdF4:Eu3+ conjugated NC permitted distinct identification of contours of the melanoma tissue on histological sections using red excitation at 590-610 nm and near infrared emission of 700-720 nm. These data are of potential practical significance for development of glycans-conjugated nanoparticles to be used for in vivo visualization of melanoma tumor. PMID:24891277

  3. Diagnosis of myocardial infarction based on lectin-induced erythrocyte agglutination: a feasibility study

    NASA Astrophysics Data System (ADS)

    Bocsi, József; Nieschke, Kathleen; Mittag, Anja; Reichert, Thomas; Laffers, Wiebke; Marecka, Monika; Pierzchalski, Arkadiusz; Piltz, Joachim; Esche, Hans-Jürgen; Wolf, Günther; Dähnert, Ingo; Baumgartner, Adolf; Tarnok, Attila

    2014-03-01

    Myocardial infarction (MI) is an acute life-threatening disease with a high incidence worldwide. Aim of this study was to test lectin-carbohydrate binding-induced red blood cell (RBC) agglutination as an innovative tool for fast, precise and cost effective diagnosis of MI. Five lectins (Ricinus communis agglutinin (RCA), Phaseolus vulgaris erythroagglutinin (PHA), Datura stramonium agglutinin (DSA), Artocarpus agglutinin (ArA), Triticum agglutinin (TA)) were tested for ability to differentiate between agglutination characteristics in patients with MI (n = 101) or angina pectoris without MI (AP) (n = 34) and healthy volunteers (HV) as control (n =68) . RBC agglutination was analyzed by light absorbance of a stirred RBC suspension in the green to red light spectrum in an agglutimeter (amtec, Leipzig, Germany) for 15 min after lectin addition. Mean cell count in aggregates was estimated from light absorbance by a mathematical model. Each lectin induced RBC agglutination. RCA led to the strongest RBC agglutination (~500 RBCs/aggregate), while the others induced substantially slower agglutination and lead to smaller aggregate sizes (5-150 RBCs/aggregate). For all analyzed lectins the lectin-induced RBC agglutination of MI or AP patients was generally higher than for HV. However, only PHA induced agglutination that clearly distinguished MI from HV. Variance analysis showed that aggregate size after 15 min. agglutination induced by PHA was significantly higher in the MI group (143 RBCs/ aggregate) than in the HV (29 RBC-s/aggregate, p = 0.000). We hypothesize that pathological changes during MI induce modification of the carbohydrate composition on the RBC membrane and thus modify RBC agglutination. Occurrence of carbohydrate-lectin binding sites on RBC membranes provides evidence about MI. Due to significant difference in the rate of agglutination between MI > HV the differentiation between these groups is possible based on PHA-induced RBC-agglutination. This novel assay could serve as a rapid, cost effective valuable new tool for diagnosis of MI.

  4. Molecular cloning, characterization and expression analysis of complement component C8 beta in the orange-spotted grouper (Epinephelus coioides) after the Vibrio alginolyticus challenge.

    PubMed

    Luo, Shengwei; Xie, Fuxing; Liu, Yuan; Wang, Wei-Na

    2015-03-10

    Complement component C8 beta was a key molecule in the complement system, mediating the MAC formation and the bacterial lysis. In this study, the full-length C8 beta (EcC8 beta) was obtained, containing a 5'UTR of 25 bp, an ORF of 1764 bp and a 3'UTR of 198 bp. The EcC8 beta gene encoded a protein of 587 amino acids with an estimated molecular mass of 65.87 kDa and a predicted isoelectric point (pI) of 6.35. The deduced amino acid sequence showed that EcC8 beta consisted of the conserved residues and the domains known to be critical for C8 beta function. The quantitative real-time PCR analysis revealed that EcC8 beta transcript was expressed in all the examined tissues, while the strong expression was observed in the liver. In addition, complement C3 was the central molecule in the complement system, converging the upstream complement signals and mediating the MAC assembly pathway, while C8 beta was indispensable for active MAC formation. Following the Vibrio challenge, the increased expression of EcC3 transcript and EcC8 beta transcript was observed in the liver and kidney. These results indicated that EcC8 beta may be an important immune-related gene, playing an important role in the immune defense against the bacterial infection via the complement pathway. PMID:25592820

  5. Retinal Pigment Epithelial Cells Mitigate the Effects of Complement Attack by Endocytosis of C5b-9

    PubMed Central

    Georgiannakis, Apostolos; Burgoyne, Tom; Lueck, Katharina; Futter, Clare; Greenwood, John

    2015-01-01

    Retinal pigment epithelial (RPE) cell death is a hallmark of age-related macular degeneration. The alternative pathway of complement activation is strongly implicated in RPE cell dysfunction and loss in age-related macular degeneration; therefore, it is critical that RPE cells use molecular strategies to mitigate the potentially harmful effects of complement attack. We show that the terminal complement complex C5b-9 assembles rapidly on the basal surface of cultured primary porcine RPE cells but disappears over 48 h without any discernable adverse effects on the cells. However, in the presence of the dynamin inhibitor dynasore, C5b-9 was almost completely retained at the cell surface, suggesting that, under normal circumstances, it is eliminated via the endocytic pathway. In support of this idea, we observed that C5b-9 colocalizes with the early endosome marker EEA1 and that, in the presence of protease inhibitors, it can be detected in lysosomes. Preventing the endocytosis of C5b-9 by RPE cells led to structural defects in mitochondrial morphology consistent with cell stress. We conclude that RPE cells use the endocytic pathway to prevent the accumulation of C5b-9 on the cell surface and that processing and destruction of C5b-9 by this route are essential for RPE cell survival. PMID:26324770

  6. Plumieribetin, a Fish Lectin Homologous to Mannose-binding B-type Lectins, Inhibits the Collagen-binding ?1?1 Integrin*

    PubMed Central

    de Santana Evangelista, Karla; Andrich, Filipe; Figueiredo de Rezende, Flávia; Niland, Stephan; Cordeiro, Marta N.; Horlacher, Tim; Castelli, Riccardo; Schmidt-Hederich, Alletta; Seeberger, Peter H.; Sanchez, Eladio F.; Richardson, Michael; Gomes de Figueiredo, Suely; Eble, Johannes A.

    2009-01-01

    Recently, a few fish proteins have been described with a high homology to B-type lectins of monocotyledonous plants. Because of their mannose binding activity, they have been ascribed a role in innate immunity. By screening various fish venoms for their integrin inhibitory activity, we isolated a homologous protein from the fin stings and skin mucus of the scorpionfish (Scorpaena plumieri). This protein inhibits ?1?1 integrin binding to basement membrane collagen IV. By protein chemical and spectroscopic means, we demonstrated that this fish protein, called plumieribetin, is a homotetramer and contains a high content of anti-parallel ? strands, similar to the mannose-binding monocot B-lectins. It lacks both N-linked glycoconjugates and common O-glycan motifs. Despite its B-lectin-like structure, plumieribetin binds to ?1?1 integrin irrespective of N-glycosylation, suggesting a direct protein-protein interaction. This interaction is independent of divalent cations. On the cellular level, plumieribetin failed to completely detach hepatocarcinoma HepG2 cells and primary arterial smooth muscle cells from the collagen IV fragment CB3. However, plumieribetin weakened the cell-collagen contacts, reduced cell spreading, and altered the actin cytoskeleton, after the compensating ?2?1 integrin was blocked. The integrin inhibiting effect of plumieribetin adds a new function to the B-lectin family, which is known for pathogen defense. PMID:19850917

  7. A Lectin with Highly Potent Inhibitory Activity toward Breast Cancer Cells from Edible Tubers of Dioscorea opposita cv. Nagaimo

    PubMed Central

    Chan, Yau Sang; Ng, Tzi Bun

    2013-01-01

    A 70-kDa galactose-specific lectin was purified from the tubers of Dioscorea opposita cv. nagaimo. The purification involved three chromatographic steps: anion exchange chromatography on a Q-Sepharose column, FPLC-anion exchange chromatography on a Mono Q column, and FPLC-gel filtration on a Superdex 75 column. The purified nagaimo lectin presented as a single 35-kDa band in reducing SDS-PAGE while it exhibited a 70-kDa single band in non-reducing SDS-PAGE suggesting its dimeric nature. Nagaimo lectin displayed moderate thermostability, retaining full hemagglutinating activity after heating up to 62°C for 30 minutes. It also manifested stability over a wide pH range from pH 2 to 13. Nagaimo lectin was a galactose-specific lectin, as evidenced by binding with galactose and galactose-containing sugars such as lactose and raffinose. The minimum concentration of galactose, lactose and raffinose required to exert an inhibitory effect on hemagglutinating activity of nagaimo lectin was 20 mM, 5 mM and 40 mM, respectively. Nagaimo lectin inhibited the growth of some cancer cell lines including breast cancer MCF7 cells, hepatoma HepG2 cells and nasopharyngeal carcinoma CNE2 cells, with IC50 values of 3.71 µM, 7.12 µM and 19.79 µM, respectively, after 24 hour treatment with nagaimo lectin. The induction of phosphatidylserine externalization and mitochondrial depolarization indicated that nagaimo lectin evoked apoptosis in MCF7 cells. However, the anti-proliferative activity of nagaimo lectin was not blocked by application of galactose, signifying that the activity was not related to the carbohydrate binding specificity of the lectin. PMID:23349827

  8. Effect of some essential oils on phagocytosis and complement system activity.

    PubMed

    Pérez-Rosés, Renato; Risco, Ester; Vila, Roser; Peńalver, Pedro; Cańigueral, Salvador

    2015-02-11

    The aim of the present study was to investigate the in vitro activity of 15 essential oils, 4 essential oil fractions, and 3 pure compounds (thymol, carvacrol, and eugenol) on phagocytosis by human neutrophils and on complement system. Samples were characterized by GC and GC-MS. Most of the oils (nutmeg, clove, niaouli, tea tree, bay laurel, lemon, red thyme, ginger), nutmeg terpenes, eugenol, and carvacrol showed mild to moderate inhibition of phagocytosis (25-40% inhibition at doses ranging from 40 to 60 ?g/mL); highest inhibitory activity was found for thymol (72% at 56 ?g/mL), whereas the mixture of bornyl and isobornyl acetates showed a mild stimulating activity (21% at 56 ?g/mL). All samples were inactive in the alternative pathway of complement system, whereas on classical pathway, clove oil, eugenol, palmarosa oil, red thyme oil, tarragon oil, and carvacrol showed the highest activity, with IC50 values ranging from 65 to 78 ?g/mL. PMID:25599399

  9. The COPII pathway and hematologic disease.

    PubMed

    Khoriaty, Rami; Vasievich, Matthew P; Ginsburg, David

    2012-07-01

    Multiple diseases, hematologic and nonhematologic, result from defects in the early secretory pathway. Congenital dyserythropoietic anemia type II (CDAII) and combined deficiency of coagulation factors V and VIII (F5F8D) are the 2 known hematologic diseases that result from defects in the endoplasmic reticulum (ER)-to-Golgi transport system. CDAII is caused by mutations in the SEC23B gene, which encodes a core component of the coat protein complex II (COPII). F5F8D results from mutations in either LMAN1 (lectin mannose-binding protein 1) or MCFD2 (multiple coagulation factor deficiency protein 2), which encode the ER cargo receptor complex LMAN1-MCFD2. These diseases and their molecular pathogenesis are the focus of this review. PMID:22586181

  10. The COPII pathway and hematologic disease

    PubMed Central

    Khoriaty, Rami; Vasievich, Matthew P.

    2012-01-01

    Multiple diseases, hematologic and nonhematologic, result from defects in the early secretory pathway. Congenital dyserythropoietic anemia type II (CDAII) and combined deficiency of coagulation factors V and VIII (F5F8D) are the 2 known hematologic diseases that result from defects in the endoplasmic reticulum (ER)–to–Golgi transport system. CDAII is caused by mutations in the SEC23B gene, which encodes a core component of the coat protein complex II (COPII). F5F8D results from mutations in either LMAN1 (lectin mannose-binding protein 1) or MCFD2 (multiple coagulation factor deficiency protein 2), which encode the ER cargo receptor complex LMAN1-MCFD2. These diseases and their molecular pathogenesis are the focus of this review. PMID:22586181

  11. Allergen-Specific Pattern Recognition Receptor Pathways

    PubMed Central

    Wills-Karp, Marsha

    2012-01-01

    Summary Allergic diseases continue to plague modernized societies, underscoring the need to identify the molecular basis for the propensity of a small number of environmental proteins to provoke maladaptive, allergic responses. Recent data suggest that the ability of allergenic proteins to drive allergic responses in susceptible hosts is driven by their unique innate immune activating capabilities. Although the identification of allergen-specific pattern recognition receptors is in its infancy, studies to date have shown that allergens drive Th2-biased immune responses via directly engaging C-type lectin receptors (dectin-2, DC-SIGN, mannose receptor) on dendritic cells and/or mimicking toll-like receptor 4 signaling complex molecules expressed on airway structural cells. Elucidation of the specific innate immune pathways activated by allergens holds great promise in defining new therapeutic targets for the treatment of allergic diseases. PMID:21093238

  12. More than just immune evasion: Hijacking complement by Plasmodium falciparum.

    PubMed

    Schmidt, Christoph Q; Kennedy, Alexander T; Tham, Wai-Hong

    2015-09-01

    Malaria remains one of the world's deadliest diseases. Plasmodium falciparum is responsible for the most severe and lethal form of human malaria. P. falciparum's life cycle involves two obligate hosts: human and mosquito. From initial entry into these hosts, malaria parasites face the onslaught of the first line of host defence, the complement system. In this review, we discuss the complex interaction between complement and malaria infection in terms of hosts immune responses, parasite survival and pathogenesis of severe forms of malaria. We will focus on the role of complement receptor 1 and its associated polymorphisms in malaria immune complex clearance, as a mediator of parasite rosetting and as an entry receptor for P. falciparum invasion. Complement evasion strategies of P. falciparum parasites will also be highlighted. The sexual forms of the malaria parasites recruit the soluble human complement regulator Factor H to evade complement-mediated killing within the mosquito host. A novel evasion strategy is the deployment of parasite organelles to divert complement attack from infective blood stage parasites. Finally we outline the future challenge to understand the implications of these exploitation mechanisms in the interplay between successful infection of the host and pathogenesis observed in severe malaria. PMID:25816986

  13. Carbohydrate-binding specificity of the daffodil (Narcissus pseudonarcissus) and amaryllis (Hippeastrum hybr.) bulb lectins.

    PubMed

    Kaku, H; Van Damme, E J; Peumans, W J; Goldstein, I J

    1990-06-01

    The carbohydrate binding specificity of the daffodil (Narcissus pseudonarcissus; NPA) and amaryllis (Hippeastrum hybr.; HHA) lectins, isolated from extracts of their bulbs by affinity chromatography on immobilized mannose, was studied by quantitative precipitation, sugar hapten inhibition, and affinity chromatography on the immobilized lectins. These lectins gave strong precipitation reactions with several yeast mannans, but did not precipitate with alpha-D-glucans (e.g., dextrans and glycogen). Interestingly, both lectins reacted strongly with yeast galactomannans having multiple nonreducing terminal alpha-D-galactosyl groups, a synthetic linear alpha-1,6-mannan, and an alpha-1,3-mannan (DP = 30). Treatment of the linear alpha-1,3-mannan with periodate, resulting in oxidation of the terminal, nonreducing mannosyl group, did not reduce its reactivity with NPA or HHA. Taken together, these observations suggest that NPA and HHA react not only with terminal but also with internal alpha-D-mannosyl residues. Sugar hapten inhibition studies showed these lectins to possess the greatest specific activity for alpha-D-mannosyl units whereas D-Glc and D-GlcNAc did not inhibit either lectin precipitation system. Of the oligosaccharides tested, the best inhibitor of NPA interaction was alpha-1,6-linked mannotriose, which was twice as good an inhibitor as Man alpha 1,6Man alpha-O-Me and 10 times better than methyl alpha-D-mannoside. On the other hand, oligosaccharides containing either 1,3- or 1,6-linked mannosyl units were good inhibitors of the HHA-mannan precipitation system (6- to 20-fold more active than D-Man). These results indicate that both lectins appear to possess an extended binding site(s) complementary to at least three 1,6-linked alpha-mannosyl units. Various glycosylasparagine glycopeptides which contain alpha-1,6-Man units were retarded on the immobilized NPA column. On the other hand, those containing either alpha-1,3- or alpha-1,6-mannosyl residues were retarded on the immobilized HHA column; Man5-GlcNAc2-Asn [containing two Man alpha 1,3(Man alpha 1,6) units] bound to the HHA column. On the contrary, glycopeptides with hybrid type glycan chains were not retarded on either column. These two new lectins which differ in their fine sugar binding specificity from each other, and also from the snowdrop lectin, should prove to be useful probes for the detection and preliminary characterization of glycoconjugates on cell surfaces and in solution. PMID:2350177

  14. Chapter 45: Antibodies and Lectins in Glycan Analysis 1. What are the advantages and disadvantages of using monoclonal antibodies versus plant

    E-print Network

    Gleeson, Joseph G.

    Chapter 45: Antibodies and Lectins in Glycan Analysis 1. What are the advantages and disadvantages of using monoclonal antibodies versus plant lectins for determining the presence or absence of glycans in a preparation? 2. What are important controls when using lectins or antiglycan antibodies to determine

  15. The effect of antibody isotype and antigenic epitope density on the complement-fixing activity of immune complexes: a systematic study using chimaeric anti-NIP antibodies with human Fc regions.

    PubMed Central

    Lucisano Valim, Y M; Lachmann, P J

    1991-01-01

    A systematic study has been carried out to investigate the role of immunoglobulin isotype, epitope density, and antigen/antibody ratio on the capacity of immune complexes to activate the classical and alternative pathways of human complement and for the complexes subsequently to bind to erythrocyte C3b-C4b receptors (CRI). For this purpose, a series of chimaeric monoclonal anti-NIP antibodies was used, which all shared the same combining site but had different human constant domains. Antigen epitope density was varied by coupling different numbers of NIP hapten molecules to bovine serum albumin. All three parameters affect complement fixation. In general, complement activation is better in antibody excess and at equivalence than it is in antigen excess, and better at high epitope density than at low epitope density, although the effects are variable for different immunoglobulin isotypes and for the two pathways. It has been confirmed that IgG1 and IgG3 are good activators of the classical pathway and are tolerant to variations in both epitope density and antigen/antibody ratio. IgG4 and IgA do not activate the classical pathway in any circumstances. IgG2 activates the classical pathway only at high epitope density and at equivalence or antibody excess. IgM activates the classical pathway well only at the higher epitope densities and at equivalence or antibody excess but, in addition, shows an interesting and unexpected prozone phenomenon where immune complex in antibody excess inhibits complement activation by the classical pathway. The results of the alternative pathway activation are strikingly different. IgA is by far the best activator of the alternative pathway and is relatively tolerant to epitope density and to antigen/antibody ratio. IgM, IgG1 and IgG3 do not significantly activate the alternative pathway in any circumstances. IgG2 is the best IgG subclass for alternative pathway activation but requires high epitope density and equivalence or antibody excess. Binding to CR1 in general parallels the amount of complement fixed independent to the pathway by which it is fixed. However, IgG1 and IgG3 complexes in antigen excess activate complement well but bind poorly to CR1. Nascently formed complexes seem to bind complement in a way that is similar to that bound by preformed complexes, but are then less able to bind to red cell CR1. These observations help to explain the pathogenesis of complement activation in various autoimmune and immune complex diseases such as systemic lupus erythematosus, autoimmune thyroiditis and others. PMID:1707767

  16. Members of a Novel Protein Family Containing Microneme Adhesive Repeat Domains Act as Sialic Acid-binding Lectins during Host Cell Invasion by Apicomplexan Parasites*

    PubMed Central

    Friedrich, Nikolas; Santos, Joana M.; Liu, Yan; Palma, Angelina S.; Leon, Ester; Saouros, Savvas; Kiso, Makoto; Blackman, Michael J.; Matthews, Stephen; Feizi, Ten; Soldati-Favre, Dominique

    2010-01-01

    Numerous intracellular pathogens exploit cell surface glycoconjugates for host cell recognition and entry. Unlike bacteria and viruses, Toxoplasma gondii and other parasites of the phylum Apicomplexa actively invade host cells, and this process critically depends on adhesins (microneme proteins) released onto the parasite surface from intracellular organelles called micronemes (MIC). The microneme adhesive repeat (MAR) domain of T. gondii MIC1 (TgMIC1) recognizes sialic acid (Sia), a key determinant on the host cell surface for invasion by this pathogen. By complementation and invasion assays, we demonstrate that TgMIC1 is one important player in Sia-dependent invasion and that another novel Sia-binding lectin, designated TgMIC13, is also involved. Using BLAST searches, we identify a family of MAR-containing proteins in enteroparasitic coccidians, a subclass of apicomplexans, including T. gondii, suggesting that all these parasites exploit sialylated glycoconjugates on host cells as determinants for enteric invasion. Furthermore, this protein family might provide a basis for the broad host cell range observed for coccidians that form tissue cysts during chronic infection. Carbohydrate microarray analyses, corroborated by structural considerations, show that TgMIC13, TgMIC1, and its homologue Neospora caninum MIC1 (NcMIC1) share a preference for ?2–3- over ?2–6-linked sialyl-N-acetyllactosamine sequences. However, the three lectins also display differences in binding preferences. Intense binding of TgMIC13 to ?2–9-linked disialyl sequence reported on embryonal cells and relatively strong binding to 4-O-acetylated-Sia found on gut epithelium and binding of NcMIC1 to 6?sulfo-sialyl Lewisx might have implications for tissue tropism. PMID:19901027

  17. Inhibition of Pasteurella multocida Adhesion to Rabbit Respiratory Epithelium Using Lectins

    PubMed Central

    Carrillo, Magda Patricia; Martinez, Nhora María; Patińo, María del Pilar; Iregui, Carlos Arturo

    2015-01-01

    This study aimed to evaluate the ability of a panel of lectins to inhibit the ability of Pasteurella multocida to adhere to and affect the rabbit respiratory epithelium. Nasal septa from rabbit fetuses were cultured with various lectins before the addition of P. multocida. The percentage of bacteria adhering to the epithelium was evaluated semiquantitatively by indirect immunoperoxidase (IIP) staining. The goblet cells (GCs) were counted in semithin sections stained with toluidine blue and served as the main morphological criterion to evaluate the inhibitory effect of the lectins. The lectins PNA, WGA, RCA120, and DBA significantly inhibited the adhesion of P. multocida to the ciliated epithelium (P < 0.05) and prevented the pathogen-induced increase in the number of GCs (P < 0.05) compared with those of positive control tissues. In addition, VVA, SJA, UEA I, DSL, SBA, and ECL significantly inhibited the increase in GCs compared with that of the control tissues. The results suggest that less aggressive therapeutic strategies, such as treatment with lectins, may represent alternative approaches to control bacterial respiratory infections. PMID:25810949

  18. Recombinant production of plant lectins in microbial systems for biomedical application - the frutalin case study.

    PubMed

    Oliveira, Carla; Teixeira, José A; Domingues, Lucília

    2014-01-01

    Frutalin is a homotetrameric partly glycosylated ?-D-galactose-binding lectin of biomedical interest from Artocarpus incisa (breadfruit) seeds, belonging to the jacalin-related lectins family. As other plant lectins, frutalin is a heterogeneous mixture of several isoforms possibly with distinct biological activities. The main problem of using such lectins as biomedical tools is that "batch-to-batch" variation in isoforms content may lead to inconstant results. The production of lectins by recombinant means has the advantage of obtaining high amounts of proteins with defined amino-acid sequences and more precise properties. In this mini review, we provide the strategies followed to produce two different forms of frutalin in two different microbial systems: Escherichia coli and Pichia pastoris. The processing and functional properties of the recombinant frutalin obtained from these hosts are compared to those of frutalin extracted from breadfruit. Emphasis is given particularly to recombinant frutalin produced in P. pastoris, which showed a remarkable capacity as biomarker of human prostate cancer and as apoptosis-inducer of cancer cells. Recombinant frutalin production opens perspectives for its development as a new tool in human medicine. PMID:25152749

  19. Establishment of new predictive markers for distant recurrence of colorectal cancer using lectin microarray analysis

    PubMed Central

    Nakajima, Kentaro; Inomata, Masafumi; Iha, Hidekatsu; Hiratsuka, Takahiro; Etoh, Tsuyoshi; Shiraishi, Norio; Kashima, Kenji; Kitano, Seigo

    2015-01-01

    We evaluated the clinical benefits of novel predictive markers for distant recurrence with colorectal cancer using lectin microarray analysis of cell surface glycan modifications. Glycoproteins were extracted from formalin-fixed, paraffin-embedded tumor specimens and normal epithelium from 53 consecutive curatively resected stage I–III colorectal cancer cases and then subjected to lectin microarray to obtain lectin–glycan interaction (LGI) values. In addition, clinicopathological factors associated with distant recurrence were identified. LGI values that were associated with distant recurrence were validated with an additional 55 curatively resected stage II colorectal cancer cases. LGI values for Agaricus bisporus (ABA) lectin, prominent in cancer tissues, were statistically associated with distant recurrence. ABA lectin staining exhibited strikingly intense signals in the cytoplasm and apical surfaces of cancer cells, while weak staining was observed in the supranuclear regions of normal epithelium. This ABA tumor/normal LGI ratio may be a new predictive biomarker for distant recurrence of curatively resected colorectal cancer. PMID:25355679

  20. Lectin characterization of gonococci from an outbreak caused by penicillin-resistant Neisseria gonorrhoeae.

    PubMed Central

    Schalla, W O; Rice, R J; Biddle, J W; Jeanlouis, Y; Larsen, S A; Whittington, W L

    1985-01-01

    A total of 40 Neisseria gonorrhoeae isolates, representing 19 penicillin-resistant isolates (from 8 heterosexual patients and 11 homosexual patients) and 21 penicillin-susceptible isolates (from 15 heterosexual patients and 6 homosexual patients) and obtained from the same geographic area, were examined. Lectin agglutination patterns were based on the reactivity of the isolates with the following 14 lectins: concanavalin A, Lens culinaris, Trichosanthes kinlowii, Griffonia simplicifolia I, Arachis hypogeae (peanut agglutinin), Glycine max (soybean agglutinin), Dolichos bifloris, Griffonia simplicifolia II, Solanum tuberosum (potato starch agglutinin), Triticum vulgaris (wheat germ agglutinin), Limax flavus, Phaseolus vulgaris, Ulex europaeus I, and Lotus tetragonolobus. All isolates were serotyped with monoclonal antibodies specific for gonococcal outer membrane protein I and auxotyped, and the plasmid content was determined. Resistant patient isolates were selected for their decreased penicillin susceptibility, and control isolates were selected for their penicillin susceptibility. Even though the patient isolates demonstrated resistance to penicillin, no phenotypic differences in lectin-grouping patterns were demonstrated between the two study groups; i.e., two predominant lectin groups were observed. No resistance-associated plasmids were detected. All patient isolates were serogroup IB (serovars IB-1, IB-2, and IB-4), whereas 12 of 21 control isolates were serogroup IA (P less than 0.05). Isolates obtained from different anatomical sites in the same patient (cervical and rectal) agreed with regard to lectin patterns and serovars but not auxotypes. PMID:3935658

  1. Identification of group B streptococcal antigen with lectin-bound polystyrene particles.

    PubMed Central

    Slifkin, M; Cumbie, R

    1987-01-01

    The lectin of the tomato, Lycopersicon esculentum, or of the potato, Solanum tuberosum, can be passively coupled to amide-modified polystyrene spheres to be used as a detection reagent for the specific identification of group B streptococcal cultures grown in selective or nonselective Todd-Hewitt broth for 5 and 4 h, respectively. Agglutination occurred when the lectin reagents were allowed to react with either the cell suspension, clarified broth, or antigen extracts from group B streptococci grown in Todd-Hewitt broth. No agglutination occurred when these lectins were allowed to react with strains of serogroup A, C, D, F, or G streptococci. False-negative agglutination responses may occur with certain serotype of group B streptococci grown on Columbia sheep blood agar. A 20-min staining time permitted the specific labeling of fixed smears of group B streptococci with fluorescein-conjugated Lycopersicon lectin. The lectin from the solanaceous plant Datura stramonium did not agglutinate group B streptococci or other clinically significant streptococcal serogroups. PMID:3301888

  2. Surface array proteins of Campylobacter fetus block lectin-mediated binding to type A lipopolysaccharide.

    PubMed Central

    Fogg, G C; Yang, L Y; Wang, E; Blaser, M J

    1990-01-01

    Campylobacter fetus strains with type A lipopolysaccharide (LPS) and a surface array protein layer (S+) have been found to be pathogenic in humans and animals. Spontaneous laboratory mutants that lack surface array proteins (S-) are sensitive to the bactericidal activity of normal human serum. The ability of lectins to determine the presence of the S-layer and differentiate LPS type was assessed. We screened 14 lectins and found 3 (wheat germ agglutinin, Bandeiraea simplicifolia II, and Helix pomatia agglutinin) that agglutinated S- C. fetus strains with type A LPS but not S- strains with type B or type C LPS or S+ strains. However, the S+ type A strains were agglutinated after sequential water extraction, heat, or pronase treatment, all of which remove the S-layer, whereas there was no effect on the control strains. Specific carbohydrates for each lectin and purified LPS from a type A C. fetus strain specifically inhibited agglutination of an S- type A strain. In a direct enzyme-linked lectin assay, binding to the S- type A LPS strain was significantly greater than binding to the S+ strain (P = 0.01) or to a Campylobacter jejuni strain (P = 0.008). Consequently, these results indicate that the three lectins bind to the O side chains of C. fetus type A LPS but that the presence of the S-layer on intact cells blocks binding. Images PMID:2387622

  3. Inhibition of Pasteurella multocida Adhesion to Rabbit Respiratory Epithelium Using Lectins.

    PubMed

    Carrillo, Magda Patricia; Martinez, Nhora María; Patińo, María Del Pilar; Iregui, Carlos Arturo

    2015-01-01

    This study aimed to evaluate the ability of a panel of lectins to inhibit the ability of Pasteurella multocida to adhere to and affect the rabbit respiratory epithelium. Nasal septa from rabbit fetuses were cultured with various lectins before the addition of P. multocida. The percentage of bacteria adhering to the epithelium was evaluated semiquantitatively by indirect immunoperoxidase (IIP) staining. The goblet cells (GCs) were counted in semithin sections stained with toluidine blue and served as the main morphological criterion to evaluate the inhibitory effect of the lectins. The lectins PNA, WGA, RCA120, and DBA significantly inhibited the adhesion of P. multocida to the ciliated epithelium (P < 0.05) and prevented the pathogen-induced increase in the number of GCs (P < 0.05) compared with those of positive control tissues. In addition, VVA, SJA, UEA I, DSL, SBA, and ECL significantly inhibited the increase in GCs compared with that of the control tissues. The results suggest that less aggressive therapeutic strategies, such as treatment with lectins, may represent alternative approaches to control bacterial respiratory infections. PMID:25810949

  4. Anti-inflammatory and antinociceptive activity of chitin-binding lectin from Canna limbata seeds.

    PubMed

    Araújo, Theolyta S; Teixeira, Claudener S; Falcăo, Maria A P; Junior, Vanir R Pinto; Santiago, Mayara Quiroz; Benevides, Raquel G; Delatorre, Plínio; Martins, Jorge L; Alexandre-Moreira, Magna S; Cavada, Benildo S; Campesatto, Eliane A; Rocha, Bruno A M

    2013-12-01

    Lectins are a structurally heterogeneous group of proteins or glycoproteins with at least one noncatalytic domain binding reversibly to a specific mono- or oligosaccharide. Monocot mannose-binding lectins are an extended superfamily of structurally and evolutionarily related proteins. In this study, we evaluated anti-inflammatory and antinociceptive effects of monocot lectin from the Canna limbata seeds (CLL). To accomplish this, CLL was purified and subjected to pharmacological assays: abdominal writhing induced by acetic acid, formalin, hot plate and Zymosan A-induced peritonitis tests. The CLL was purified by chromatographic chitin column, and the relative mass of 21 kDa observed in electrophoresis was confirmed by electrospray mass spectrometry, which also revealed that purified CLL consists of a dimer having a weight of 49,676 Da. The CLL showed nociceptive activity in the acetic acid test as well as peripheral antinociceptive response. The CLL also showed anti-inflammatory effect with the reduction of inflammation in the formalin test and neutrophil migration into the peritoneal cavity. This is the first report of anti-inflammatory activity for a monocot lectin, and it suggests a new pharmacological tool to understand inflammatory and antinociceptive processes mediated through lectins. PMID:24013883

  5. A Computational Approach for Exploring Carbohydrate Recognition by Lectins in Innate Immunity

    PubMed Central

    Agostino, Mark; Yuriev, Elizabeth; Ramsland, Paul A.

    2011-01-01

    Recognition of pathogen-associated carbohydrates by a broad range of carbohydrate-binding proteins is central to both adaptive and innate immunity. A large functionally diverse group of mammalian carbohydrate-binding proteins are lectins, which often display calcium-dependent carbohydrate interactions mediated by one or more carbohydrate recognition domains. We report here the application of molecular docking and site mapping to study carbohydrate recognition by several lectins involved in innate immunity or in modulating adaptive immune responses. It was found that molecular docking programs can identify the correct carbohydrate-binding mode, but often have difficulty in ranking it as the best pose. This is largely attributed to the broad and shallow nature of lectin binding sites, and the high flexibility of carbohydrates. Site mapping is very effective at identifying lectin residues involved in carbohydrate recognition, especially with cases that were found to be particularly difficult to characterize via molecular docking. This study highlights the need for alternative strategies to examine carbohydrate–lectin interactions, and specifically demonstrates the potential for mapping methods to extract additional and relevant information from the ensembles of binding poses generated by molecular docking. PMID:22566813

  6. Antiproliferative effects of lectins from Canavalia ensiformis and Canavalia brasiliensis in human leukemia cell lines.

    PubMed

    Faheina-Martins, Glaucia V; da Silveira, Alethéia Lacerda; Cavalcanti, Bruno C; Ramos, Márcio V; Moraes, Manoel O; Pessoa, Cláudia; Araújo, Demetrius A M

    2012-10-01

    The antiproliferative activity of lectins Canavalia ensiformis (ConA) and Canavalia brasiliensis (ConBr) were studied using human leukemia MOLT-4 and HL-60 cell lines. It was revealed that both ConA and ConBr were markedly cytotoxic to cells using MTT and NAC assays. The IC(50) values were approximately 3 and 20 ?g/mL for ConA and ConBr, respectively, for both MOLT-4 and HL-60 cells. However, in normal human peripheral blood lymphocytes, the lectins were not cytotoxic, even when tested at concentrations as high as 200 ?g/ml. Using comet assay, the lectins produced a rate of DNA damage exceeding 80% in MOLT-4 and HL-60 cells. Fluorescence analysis revealed the morphology characteristic of apoptosis, with low concentrations of apoptotic bodies and fragmented DNA (5 ?g/ml). Flow cytometric analysis demonstrated an accumulation of cells in the sub-G1 cell cycle that is characteristic of DNA fragmentation, and a decrease in membrane integrity at high concentrations. Lastly, we evaluated the alterations in mitochondrial potential that reduced after treatment with lectins. Our results indicate that ConA and ConBr inhibited cell proliferation selectively in tumor cells and that apoptosis was the main death mechanism. Therefore, lectins can be considered a class of molecules with a high antitumor activity potential. PMID:22776218

  7. Recombinant production of plant lectins in microbial systems for biomedical application – the frutalin case study

    PubMed Central

    Oliveira, Carla; Teixeira, José A.; Domingues, Lucília

    2014-01-01

    Frutalin is a homotetrameric partly glycosylated ?-D-galactose-binding lectin of biomedical interest from Artocarpus incisa (breadfruit) seeds, belonging to the jacalin-related lectins family. As other plant lectins, frutalin is a heterogeneous mixture of several isoforms possibly with distinct biological activities. The main problem of using such lectins as biomedical tools is that “batch-to-batch” variation in isoforms content may lead to inconstant results. The production of lectins by recombinant means has the advantage of obtaining high amounts of proteins with defined amino-acid sequences and more precise properties. In this mini review, we provide the strategies followed to produce two different forms of frutalin in two different microbial systems: Escherichia coli and Pichia pastoris. The processing and functional properties of the recombinant frutalin obtained from these hosts are compared to those of frutalin extracted from breadfruit. Emphasis is given particularly to recombinant frutalin produced in P. pastoris, which showed a remarkable capacity as biomarker of human prostate cancer and as apoptosis-inducer of cancer cells. Recombinant frutalin production opens perspectives for its development as a new tool in human medicine. PMID:25152749

  8. Mitigation of arsenic-mediated renal oxidative stress in rat by Pleurotus florida lectin.

    PubMed

    Bera, Asit Kumar; Rana, Tanmoy; Das, Subhashree; Bhattacharya, Debasis; Pan, Diganta; Bandyopadhyay, Subhasish; Das, Subrata Kumar

    2011-08-01

    Oyster mushroom, Pleurotus florida is regarded as one of the popular food with biopharmaceutical properties. Here, the study aimed to investigate the antioxidative effects of mushroom (Pleurotus florida) lectin against arsenic-induced nephrotoxicity in rats. Animals were divided into four groups; Group 1 was control. Groups 2, 3 and 4 were exposed to arsenic (20 parts per million [ppm] in drinking water), arsenic plus oral supplementation of ascorbic acid (25 mg/kg body weight) and arsenic plus oral supplementation of mushroom lectin (150 mg/kg body weight) respectively. Both ascorbic acid and mushroom lectin prevented the arsenic-mediated growth retardation and normalized the elevated kidney weight. Disrupted activities of superoxide dismutase (SOD) and catalase (CAT) and enhanced lipid peroxidation (LPO), protein carbonyl (PC) and nitric oxides (NO) production in kidney caused by arsenic could also be maintained towards normalcy by supplementation of mushroom lectin and ascorbic acid. These antioxidative effects were exhibited in a time-dependant manner. Further, arsenic-mediated down-regulation of messenger RNA (mRNA) expression of superoxide dismutase 2 (SOD(2)) gene was obstructed by these agents. Thus it was found that mushroom lectin reversed the effect of arsenic-mediated oxidative stress in a time-dependent manner. PMID:20876158

  9. Functional complementation between the PDX1 vitamin B6 biosynthetic gene of Cercospora nicotianae and pdxJ of Escherichia coli

    E-print Network

    Daub, Margaret

    Functional complementation between the PDX1 vitamin B6 biosynthetic gene of Cercospora nicotianae Abstract The pathway for de novo vitamin B6 biosynthesis has been characterized in Escherichia coli vitamin B6 is used to refer collectively to the compound pyridoxine and its vitameric forms, pyridoxal

  10. Lectin-Based Characterization of Vascular Cell Microparticle Glycocalyx

    PubMed Central

    Scruggs, April K.; Cioffi, Eugene A.; Cioffi, Donna L.; King, Judy A. C.; Bauer, Natalie N.

    2015-01-01

    Microparticles (MPs) are released constitutively and from activated cells. MPs play significant roles in vascular homeostasis, injury, and as biomarkers. The unique glycocalyx on the membrane of cells has frequently been exploited to identify specific cell types, however the glycocalyx of the MPs has yet to be defined. Thus, we sought to determine whether MPs, released both constitutively and during injury, from vascular cells have a glycocalyx matching those of the parental cell type to provide information on MP origin. For these studies we used rat pulmonary microvascular and artery endothelium, pulmonary smooth muscle, and aortic endothelial cells. MPs were collected from healthy or cigarette smoke injured cells and analyzed with a panel of lectins for specific glycocalyx linkages. Intriguingly, we determined that the MPs released either constitutively or stimulated by CSE injury did not express the same glycocalyx of the parent cells. Further, the glycocalyx was not unique to any of the specific cell types studied. These data suggest that MPs from both normal and healthy vascular cells do not share the parental cell glycocalyx makeup. PMID:26274589

  11. The peanut lectin-binding glycoproteins of human epidermal keratinocytes

    SciTech Connect

    Morrison, A.I. ); Keeble, S.; Watt, F.M. )

    1988-08-01

    The peanut lectin (PNA) is known to bind more strongly to keratinocytes that are undergoing terminal differentiation than to proliferating keratinocytes. In order to investigate the significance of this change in cell-surface carbohydrate authors have identified the PNA-binding glycoproteins of cultured human keratinocytes and antibodies against them. Two heavily glycosylated bands of 110 and 250 kDa were resolved by PAGE of ({sup 14}C)galactose- or ({sup 14}C)mannose- and ({sup 14}C)glucosamine-labeled cell extracts eluted with galactose from PNA affinity columns. The higher molecular weight band was also detected on PNA blots of unlabeled cell extracts transferred to nitrocellulose. Both bands were sensitive to pronase digestion, but only the 250-kDa band was digested with trypsin. A rabbit antiserum that we prepared (anti-PNA-gp) immunoprecipitated both bands from cell extracts. In contrast to PNA, anti-PNA-gp bound equally to proliferating and terminally differentiating cells, indicating that some epitope(s) of the PNA-binding glycoproteins is present on the cell surface prior to terminal differentiation. When keratinocytes grown as a monolayer in low-calcium medium were switched to medium containing 2 mM calcium ions in order to induce desmosome formation and stratification, there was a dramatic redistribution of the PNA-binding glycoproteins, which became concentrated at the boundaries between cells. This may suggest a role for the glycoproteins in cell-cell interactions during stratification.

  12. Activity of mannose-binding lectin (MBL) in centenarians

    PubMed Central

    Tomaiuolo, Rossella; Ruocco, Anna; Salapete, Chiara; Carru, Ciriaco; Baggio, Giovannella; Franceschi, Claudio; Zinellu, Angelo; Vaupel, James; Bellia, Chiara; Sasso, Bruna Lo; Ciaccio, Marcello; Castaldo, Giuseppe; Deiana, Luca

    2013-01-01

    We analyzed MBL2 gene variants in two cohorts of centenarians, octo-and nonagenarians and in the general population, one from Sardinia island (Italy), recruited in the frame of the AKea study, and another from Campania (southern Italy), to search for haplotypes related to longevity. We also assessed in vitro the effect of mannose-binding lectin (MBL) on various human cells at different stage of senescence. The frequency of high and null activity haplotypes was significantly lower and the frequency of intermediate activity haplotype significantly higher in centenarians and in subjects between 80 and 99 years from both the cohorts as compared each to the general population from the same geographic area. Furthermore, serum MBL concentration (also after normalization to serum albumin) was significantly lower in centenarians and in octo- and nonagenarians as compared to the general population suggesting that intermediate MBL haplotype/activity may be protective. We also demonstrated that in vitro MBL protein bound to senescent IMR90 fibroblasts thereby causing cell lysis, but not to other types of cycle-arrested cells not in senescence. This implicates a novel role of MBL in the clearance of senescent cells. PMID:22239660

  13. Lectin-carbohydrate affinity measured using a quartz crystal microbalance.

    PubMed

    Lebed, Kateryna; Kulik, Andrzej J; Forró, László; Lekka, Ma?gorzata

    2006-07-01

    The association of two molecules is described by two parameters, association equilibrium and association rate constants, which are characteristic for a given type of interaction. Usually, they are determined for interacting molecules dissolved in solution. However, for many applications one type of molecules is immobilized on a substrate, which may influence the binding kinetics. The studied complex of concanavalin A and carboxypeptidase Y belongs to the lectin-carbohydrate type of interaction involving the recognition of oligosaccharide moieties. The concanavalin A was immobilized on a gold electrode of quartz crystal, while carboxypeptidase Y was added to a buffer (Tris-buffered saline). The constants describing the association of the investigated molecules were determined on the basis of measurements performed using a quartz crystal microbalance in liquid. The obtained values were (0.59+/-0.01)x10(6) M(-1) for the association equilibrium constant and (5.6+/-0.1)x10(4) M(-1)s(-1) for the association rate constant. The saturation binding experiment gave another value of the association constant, (2.7+/-0.02)x10(6) M(-1). The comparison of obtained values with previously published ones verifies that the molecule orientation and binding site accessibility for specific ligands could influence the association equilibrium constant value. The presented measurements demonstrate the ability of a quartz crystal microbalance to detect and to evaluate the association process occurring between molecules. PMID:16529761

  14. Targeting C-Type Lectin Receptors for Cancer Immunity

    PubMed Central

    Yan, Huimin; Kamiya, Tomomori; Suabjakyong, Papawee; Tsuji, Noriko M.

    2015-01-01

    C-type lectin receptors (CLRs) are a large family of soluble and trans-membrane pattern recognition receptors that are widely and primarily expressed on myeloid cells. CLRs are important for cell–cell communication and host defense against pathogens through the recognition of specific carbohydrate structures. Similar to a family of Toll-like receptors, CLRs signaling are involved in the various steps for initiation of innate immune responses and promote secretion of soluble factors such as cytokines and interferons. Moreover, CLRs contribute to endocytosis and antigen presentation, thereby fine-tune adaptive immune responses. In addition, there may also be a direct activation of acquired immunity. On the other hand, glycans, such as mannose structures, Lewis-type antigens, or GalNAc are components of tumor antigens and ligate CLRs, leading to immunoregulation. Therefore, agonists or antagonists of CLRs signaling are potential therapeutic reagents for cancer immunotherapy. We aim to overview the current knowledge of CLRs signaling and the application of their ligands on tumor-associating immune response. PMID:26379663

  15. [Purification and characterization of hemolymph lectin from Tegillarca granosa Linnaeus].

    PubMed

    Chen, Yin Shan; Ke, Jia Ying; Rao, Xiao Zhen

    2006-10-01

    Agglutinin with hemagglutinating activity was found in hemolymph of Tegillarca granosa Linnaeus. By extraction, fraction with saturated ammonium sulfate precipitation, gel filtration on Sephadex G-100 and followed by affinity chromatography on Sepharose 4B, an agglutinin was purified from the hemolymph of T. granosa. The purified lectin contains 5.02% neutral saccharide. The molecular weights is about 123 KDa, which showed 2 bands on SDS-PAGE, and the relative molecular weights of these subunits were 15 KDa and 16 KDa, respectively. In its amino acid composition, Asp has the highest content, followed by Glu and His, but there is a lack of Met. Assays for erythrocyte agglutination and sugar inhibition were done in microtiter plates. The result indicared that TGL-hemolymph could agglutinate erythrocytes from the natural and enzyme-treated erythrocytes of human and animals, and the highest activity was found in the agglutination with rabbit erythrocytes. The agglutinic activity of TGL-hemolymph was inhibited by lactose and D-galactose. The hemagglutination activity of TGL-hemolymph depended on Ca2+, and it showed the highest hemagglutination activity in pH 7.0. Thermostability was not high. The agglutinating activities changed from 2(5) to 2(1) between 30-70 degrees C, and was completely destroyed beyond 80 degrees C. PMID:17117556

  16. Identification of receptors responsible for binding of the mannose specific lectin to the gut epithelial membrane of the target insects.

    PubMed

    Majumder, Pralay; Banerjee, Santanu; Das, Sampa

    2004-01-01

    The sap-sucking homopteran insects, commonly known as aphids and leafhoppers are responsible for a huge amount of lost productivity of mustard, chickpea, cabbage, rice and many other important crops. Due to their unique feeding habits and ability to build up a huge population in a very short time, they are very difficult to control. The objective of the ongoing program is to develop insect-resistant crop species through genetic engineering techniques to combat the yield losses, which necessitates the identification of appropriate control elements. In this direction, mannose-binding 25 kDa lectins have been purified from leaves of garlic, Diffenbachia sequina and tubers of Colocasia esculanta. The purified lectins have been analyzed in SDS-PAGE. The effectiveness of these lectins against chickpea aphids, mustard aphids and green leaf hoppers of rice have been tested. The LC(50) value of each lectin against different insects had been monitored [1,2]. Through immunolocalization analysis, the binding of the lectin had been demonstrated at the epithelial membrane of the midgut of the lectin-treated insects [1]. Receptor proteins of brush border membrane vesicle (BBMV) of the target insects, responsible for binding of the lectin to the midgut of the epithelial layer have been purified and analyzed through ligand assay. Biochemical studies have been undertaken to investigate the lectin-receptor interaction at molecular level. PMID:15454690

  17. The identification of in vitro production of lectin from callus cultures of Korean mistletoe (Viscum album L. var. coloratum).

    PubMed

    Lee, Keun Pyo; Lee, Dae Won

    2013-01-01

    Despite potential medical, economical, and agronomical importance, the bioprocessing of mistletoe cell cultures, from callus cultures to mass production of high-value products (e.g., lectins and viscotoxins), has been unsuccessful to date. In this study, we confirmed the potential of in vitro lectin production from callus cultures of Korean mistletoe (Viscum album L. var. coloratum). PMID:23563554

  18. A Glucosamine-Specific Lectin from Green Dragon No. 8 Beans (Phaseolus vulgaris) Induced Apoptosis on Nasopharyngeal Carcinoma Cells

    PubMed Central

    Chan, Yau Sang; Xia, Lixin; Ng, Tzi Bun

    2015-01-01

    A lectin exhibiting antiproliferative activity on tumor cell lines but devoid of antifungal activity has been purified from Phaseolus vulgaris cv. Green Dragon no. 8 seeds. The lectin was a 60?kDa dimeric protein with two 30?kDa subunits. It was a glucosamine-specific lectin as implied from the inhibitory effect of glucosamine on hemagglutinating activity of the lectin. The steps for isolation of the lectin involved Affi-gel blue gel (affinity gel), Mono Q (anion exchanger), and Superdex 75 column (size exclusion). The lectin was purified 20.8-fold from the crude extract of the beans. The purified lectin showed antiproliferative activity on breast cancer MCF7 cell line and nasopharyngeal cancer HONE1 and CNE2 cell lines, but a low activity on normal skin fibroblast HSF98 cell line. The lectin was shown to induce apoptosis on HONE1 cells, as indicated by increased phosphatidylserine externalization and mitochondrial depolarization. It also blocked HONE1 cell division and kept the cells at the G2/M phase of the cell cycle. PMID:26290674

  19. Molecular Basis for E-cadherin Recognition by Killer Cell Lectin-like Receptor G1 (KLRG1)*S

    E-print Network

    Ikura, Mitsuhiko

    Molecular Basis for E-cadherin Recognition by Killer Cell Lectin-like Receptor G1 (KLRG1)*S of Toronto, Toronto, Ontario M5G 2M9, Canada The killer cell lectin-like receptor G1, KLRG1, is a cell surface receptor expressed on subsets of natural killer (NK) cells and T cells. KLRG1 was recently found

  20. Affinity of a galactose-specific legume lectin from Dolichos lablab to adenine revealed by X-ray cystallography.

    PubMed

    Shetty, Kartika N; Latha, Vakada Lavanya; Rao, Rameshwaram Nagender; Nadimpalli, Siva Kumar; Suguna, Kaza

    2013-07-01

    Crystal structure analysis of a galactose-specific lectin from a leguminous food crop Dolichos lablab (Indian lablab beans) has been carried out to obtain insights into its quaternary association and lectin-carbohydrate interactions. The analysis led to the identification of adenine binding sites at the dimeric interfaces of the heterotetrameric lectin. Structural details of similar adenine binding were reported in only one legume lectin, Dolichos biflorus, before this study. Here, we present the structure of the galactose-binding D. lablab lectin at different pH values in the native form and in complex with galactose and adenine. This first structure report on this lectin also provides a high resolution atomic view of legume lectin-adenine interactions. The tetramer has two canonical and two DB58-like interfaces. The binding of adenine, a non-carbohydrate ligand, is found to occur at four hydrophobic sites at the core of the tetramer at the DB58-like dimeric interfaces and does not interfere with the carbohydrate-binding site. To support the crystallographic observations, the adenine binding was further quantified by carrying out isothermal calorimetric titration. By this method, we not only estimated the affinity of the lectin to adenine but also showed that adenine binds with negative cooperativity in solution. PMID:23794513

  1. A heterogeneous sialic acid-binding lectin with affinity for bacterial LPS from horse mussel (Modiolus modiolus) hemolymph.

    PubMed

    Tunkijjanukij, S; Mikkelsen, H V; Olafsen, J A

    1997-06-01

    A sialic acid-binding lectin that agglutinates a variety of erythrocytes and bacteria and react with sialoconjugates and purified lipopolysaccharides from marine vibrios has been affinity purified from hemolymph of the horse mussel Modiolus modiolus using Bovine submaxillary mucin conjugated to CNBr-activated Sepharose 4B. The lectin demonstrated heterogeneous activity, and at least two main entities were partially characterized, and are referred to as modiolin H and modiolin E activities for the agglutination of human and horse (equine) erythrocytes, respectively. Only modiolin E activity required calcium ions for hemagglutination. The M. modiolus lectin was mainly specific for NeuAc, although the lectin demonstrated a broader range of specificity, similarly to the Limulus polyphemus lectin. The purified lectin was a glycoprotein, and in the native state existed as aggregates with M(r) in the range of 100-1,300 kDa as observed by gradient-gel electrophoresis and gel filtration on Biogel and Superose. SDS-PAGE under reducing conditions revealed three subunits of M(r) 14, 17.5 and 20 kDa. Various marine bacteria adsorbed the hemagglutinating activities of the M. modiolus lectin. Purified LPS preparations from various pathogenic marine vibrios were also effective inhibitors, in particular for modiolin E activity. These results indicate that the lectin play a role in recognition of bacteria. PMID:9226886

  2. Susceptibility of human trophoblast to killing by human complement and the role of the complement regulatory proteins.

    PubMed

    Tedesco, F; Narchi, G; Radillo, O; Meri, S; Ferrone, S; Betterle, C

    1993-08-01

    The susceptibility of trophoblast to cytolysis by human complement was investigated using cells purified to over 90% from first trimester placentae. Two assay systems were employed to measure the killing of trophoblasts, an antibody-dependent complement-mediated cytolysis and the reactive lysis. The antibody obtained from a patient with Addison's disease reacted specifically with syncytiotrophoblasts and induced a dose-dependent killing of the cells not exceeding 50% even in the presence of excess antibody and complement. The percentage of cells killed by the terminal complement complex in the reactive lysis system was somewhat higher, reaching values of 60%. Immunofluorescence analysis revealed the presence of CD46 and CD59 on all syncytiotrophoblasts, whereas CD55 was only detected on approximately 30% of the cells. Inhibition of CD46 and CD59 resulted in increased susceptibility of syncytiotrophoblasts to complement lysis. The protective function of CD55 could not be evaluated because of its reduced expression on isolated trophoblasts. These results suggest that syncytiotrophoblasts may be killed by complement and that membrane regulators to some extent protect these cells from complement damage. PMID:7687635

  3. Murine Hyperglycemic Vasculopathy and Cardiomyopathy: Whole-Genome Gene Expression Analysis Predicts Cellular Targets and Regulatory Networks Influenced by Mannose Binding Lectin

    PubMed Central

    Zou, Chenhui; La Bonte, Laura R.; Pavlov, Vasile I.; Stahl, Gregory L.

    2012-01-01

    Hyperglycemia, in the absence of type 1 or 2 diabetes, is an independent risk factor for cardiovascular disease. We have previously demonstrated a central role for mannose binding lectin (MBL)-mediated cardiac dysfunction in acute hyperglycemic mice. In this study, we applied whole-genome microarray data analysis to investigate MBL’s role in systematic gene expression changes. The data predict possible intracellular events taking place in multiple cellular compartments such as enhanced insulin signaling pathway sensitivity, promoted mitochondrial respiratory function, improved cellular energy expenditure and protein quality control, improved cytoskeleton structure, and facilitated intracellular trafficking, all of which may contribute to the organismal health of MBL null mice against acute hyperglycemia. Our data show a tight association between gene expression profile and tissue function which might be a very useful tool in predicting cellular targets and regulatory networks connected with in vivo observations, providing clues for further mechanistic studies. PMID:22375142

  4. 21 CFR 866.5240 - Complement components immunological test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...and C9 , in serum, other body fluids, and tissues. Complement is a group of serum proteins which destroy infectious agents. Measurements of these proteins aids in the diagnosis of immunologic disorders, especially those associated with...

  5. 21 CFR 866.5240 - Complement components immunological test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...and C9 , in serum, other body fluids, and tissues. Complement is a group of serum proteins which destroy infectious agents. Measurements of these proteins aids in the diagnosis of immunologic disorders, especially those associated with...

  6. Complement in immune and inflammatory disorders: therapeutic interventions

    PubMed Central

    Ricklin, Daniel; Lambris, John D.

    2013-01-01

    With the awareness that immune-inflammatory crosstalk is at the heart of many disorders, the desire for novel immunomodulatory strategies in the therapy of such diseases has grown dramatically. As a prime initiator and important modulator of immunological and inflammatory processes, the complement system has emerged as an attractive target for early and upstream intervention in inflammatory diseases and has moved into the spotlight of drug discovery. While prevalent conditions such as age-related macular degeneration have attracted the most attention, the diverse array of complement-mediated pathologies, with distinct underlying mechanisms, demands a multifaceted arsenal of therapeutic strategies. Fortunately, efforts in recent years have not only introduced the first complement inhibitors to the clinic but also filled the pipelines with promising candidates. With a focus on immunomodulatory strategies, this review discusses complement-directed therapeutic concepts and highlights promising candidate molecules. PMID:23564578

  7. 21 CFR 866.5240 - Complement components immunological test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...components immunological test system. 866.5240 Section...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Immunological Test Systems § 866.5240 Complement...components immunological test system is a device that consists... , in serum, other body fluids, and...

  8. 21 CFR 866.5240 - Complement components immunological test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...components immunological test system. 866.5240 Section...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Immunological Test Systems § 866.5240 Complement...components immunological test system is a device that consists... , in serum, other body fluids, and...

  9. 21 CFR 866.5240 - Complement components immunological test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...components immunological test system. 866.5240 Section...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Immunological Test Systems § 866.5240 Complement...components immunological test system is a device that consists... , in serum, other body fluids, and...

  10. Acquisition of the T and C system in clausal complements

    E-print Network

    Norris, Rebecca L. (Rebecca Lynn), 1977-

    2004-01-01

    In order to discover how children acquire the T(ense) and C(omplementizer) system, finite and nonfinite embedded clauses produced by children in the CHILDES database were studied. It was discovered that young children often ...

  11. Complementing Gaia from the ground. The DANCe survey

    NASA Astrophysics Data System (ADS)

    Bouy, H.; Bertin, E.; Sarro, L. M.; Moraux, E.; Barrado, D.; Cuillandre, J. C.; Bouvier, J.; Berihuete, A.; Wright, N.; Beletsky, Y.; Brandner, W.; Olivares, J.

    The DANCe survey aims at complementing Gaia by providing proper motion measurements with a comparable accuracy 4 magnitudes fainter. These measurements are used to identify sub-stellar members of young nearby clusters and associations down the planetary mass regime.

  12. Molecular cloning and characterization of a novel mannose-binding lectin cDNA from Zantedeschia aethiopica.

    PubMed

    Chen, Zhonghai; Pang, Yongzhen; Liu, Xiaojun; Wang, Xinglong; Deng, Zhongxiang; Sun, Xiaofen; Tang, Kexuan

    2005-08-01

    Using RNA extracted from Zantedeschia aethiopica young leaves and primers designed according to the conservative regions of Araceae lectins, the full-length cDNA of Z. aethiopica agglutinin (ZAA) was cloned by rapid amplification of cDNA ends (RACE). The full-length cDNA of zaa was 871 bp and contained a 417 bp open reading frame (ORF) encoding a lectin precursor of 138 amino acids. Through comparative analysis of zaa gene and its deduced amino acid sequence with those of other Araceae species, it was found that zaa encoded a precursor lectin with signal peptide. Secondary and three-dimensional structure analyses showed that ZAA had many common characters of mannose-binding lectin superfamily and ZAA was a mannose-binding lectin with three mannose-binding sites. Southern blot analysis of the genomic DNA revealed that zaa belonged to a multi-copy gene family. PMID:16187498

  13. Community-Based Network Study of Protein-Carbohydrate Interactions in Plant Lectins Using Glycan Array Data

    PubMed Central

    Malik, Adeel; Lee, Juyong; Lee, Jooyoung

    2014-01-01

    Lectins play major roles in biological processes such as immune recognition and regulation, inflammatory responses, cytokine signaling, and cell adhesion. Recently, glycan microarrays have shown to play key roles in understanding glycobiology, allowing us to study the relationship between the specificities of glycan binding proteins and their natural ligands at the omics scale. However, one of the drawbacks in utilizing glycan microarray data is the lack of systematic analysis tools to extract information. In this work, we attempt to group various lectins and their interacting carbohydrates by using community-based analysis of a lectin-carbohydrate network. The network consists of 1119 nodes and 16769 edges and we have identified 3 lectins having large degrees of connectivity playing the roles of hubs. The community based network analysis provides an easy way to obtain a general picture of the lectin-glycan interaction and many statistically significant functional groups. PMID:24755681

  14. 21 CFR 866.5240 - Complement components immunological test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Complement components immunological test system. 866.5240 Section 866.5240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... complement components C1q, C1r, C1s, C2, C3, C4, C5, C6, C7, C8, and C9, in serum, other body fluids,...

  15. 21 CFR 866.5240 - Complement components immunological test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Complement components immunological test system. 866.5240 Section 866.5240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... complement components C1q, C1r, C1s, C2, C3, C4, C5, C6, C7, C8, and C9, in serum, other body fluids,...

  16. 21 CFR 866.5240 - Complement components immunological test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Complement components immunological test system. 866.5240 Section 866.5240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... complement components C1q, C1r, C1s, C2, C3, C4, C5, C6, C7, C8, and C9, in serum, other body fluids,...

  17. 21 CFR 866.5240 - Complement components immunological test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Complement components immunological test system. 866.5240 Section 866.5240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... complement components C1q, C1r, C1s, C2, C3, C4, C5, C6, C7, C8, and C9, in serum, other body fluids,...

  18. 21 CFR 866.5240 - Complement components immunological test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Complement components immunological test system. 866.5240 Section 866.5240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... complement components C1q, C1r, C1s, C2, C3, C4, C5, C6, C7, C8, and C9, in serum, other body fluids,...

  19. Complement and cytokine response in acute Thrombotic Thrombocytopenic Purpura

    PubMed Central

    Westwood, John-Paul; Langley, Kathryn; Heelas, Edward; Machin, Samuel J; Scully, Marie

    2014-01-01

    Complement dysregulation is key in the pathogenesis of atypical Haemolytic Uraemic Syndrome (aHUS), but no clear role for complement has been identified in Thrombotic Thrombocytopenic Purpura (TTP). We aimed to assess complement activation and cytokine response in acute antibody-mediated TTP. Complement C3a and C5a and cytokines (interleukin (IL)-2, IL-4, IL-6, IL-10, tumour necrosis factor, interferon-? and IL-17a) were measured in 20 acute TTP patients and 49 remission cases. Anti-ADAMTS13 immunoglobulin G (IgG) subtypes were measured in acute patients in order to study the association with complement activation. In acute TTP, median C3a and C5a were significantly elevated compared to remission, C3a 63·9 ng/ml vs. 38·2 ng/ml (P < 0·001) and C5a 16·4 ng/ml vs. 9·29 ng/ml (P < 0·001), respectively. Median IL-6 and IL-10 levels were significantly higher in the acute vs. remission groups, IL-6: 8 pg/ml vs. 2 pg/ml (P = 0·003), IL-10: 6 pg/ml vs. 2 pg/ml (P < 0·001). C3a levels correlated with both anti-ADAMTS13 IgG (rs = 0·604, P = 0·017) and IL-10 (rs = 0·692, P = 0·006). No anti-ADAMTS13 IgG subtype was associated with higher complement activation, but patients with the highest C3a levels had 3 or 4 IgG subtypes present. These results suggest complement anaphylatoxin levels are higher in acute TTP cases than in remission, and the complement response seen acutely may relate to anti-ADAMTS13 IgG antibody and IL-10 levels. PMID:24372446

  20. Impedance-derived electrochemical capacitance spectroscopy for the evaluation of lectin-glycoprotein binding affinity.

    PubMed

    Santos, Adriano; Carvalho, Fernanda C; Roque-Barreira, Maria-Cristina; Bueno, Paulo R

    2014-12-15

    Characterization of lectin-carbohydrate binding using label-free methods such as impedance-derived electrochemical capacitance spectroscopy (ECS) is desirable to evaluate specific interactions, for example, ArtinM lectin and horseradish peroxidase (HRP) glycoprotein, used here as a model for protein-carbohydrate binding affinity. An electroactive molecular film comprising alkyl ferrocene as a redox probe and ArtinM as a carbohydrate receptive center to target HRP was successfully used to determine the binding affinity between ArtinM and HRP. The redox capacitance, a transducer signal associated with the alkyl ferrocene centers, was obtained by ECS and used in the Langmuir adsorption model to obtain the affinity constant (1.6±0.6)×10(8) L mol(-1). The results shown herein suggest the feasibility of ECS application for lectin glycoarray characterization. PMID:24994505