Mannose-binding lectin binds to Ebola and Marburg envelope glycoproteins, resulting in blocking of virus interaction with DC-SIGN and complement-mediated virus neutralization.

PubMed

Ji, Xin; Olinger, Gene G; Aris, Sheena; Chen, Ying; Gewurz, Henry; Spear, Gregory T

2005-09-01

Mannose-binding lectin (MBL), a serum lectin that mediates innate immune functions including activation of the lectin complement pathway, binds to carbohydrates expressed on some viral glycoproteins. In this study, the ability of MBL to bind to virus particles pseudotyped with Ebola and Marburg envelope glycoproteins was evaluated. Virus particles bearing either Ebola (Zaire strain) or Marburg (Musoke strain) envelope glycoproteins bound at significantly higher levels to immobilized MBL compared with virus particles pseudotyped with vesicular stomatitis virus glycoprotein or with no virus glycoprotein. As observed in previous studies, Ebola-pseudotyped virus bound to cells expressing the lectin DC-SIGN (dendritic cell-specific intercellular adhesion molecule 3-grabbing non-integrin). However, pre-incubation of virus with MBL blocked DC-SIGN-mediated binding to cells, suggesting that the two lectins bind at the same or overlapping sites on the Ebola glycoprotein. Neutralization experiments showed that virus pseudotyped with Ebola or Marburg (Musoke) glycoprotein was neutralized by complement, while the Marburg (Ravn strain) glycoprotein-pseudotyped virus was less sensitive to neutralization. Neutralization was partially mediated through the lectin complement pathway, since a complement source deficient in MBL was significantly less effective at neutralizing viruses pseudotyped with filovirus glycoproteins and addition of purified MBL to the MBL-deficient complement increased neutralization. These experiments demonstrated that MBL binds to filovirus envelope glycoproteins resulting in important biological effects and suggest that MBL can interact with filoviruses during infection in humans.

Calcium-independent haemolysis via the lectin pathway of complement activation in the guinea-pig and other *

PubMed Central

Zhang, Y; Suankratay, C; Zhang, X-H; Jones, D R; Lint, T F; Gewurz, H

1999-01-01

We previously reported that complement-dependent haemolysis of sheep erythrocytes (E) coated with mannan (M) and sensitized with human mannan-binding lectin (MBL) via the lectin pathway in man occurs in Mg-EGTA and requires alternative pathway amplification. Calcium was required for MBL binding to E-M, but once the E-M-MBL intermediate was formed, MBL was retained and haemolysis occurred in the absence of calcium. Comparable or greater lectin pathway haemolysis in the absence of calcium was observed upon incubation of E-M-MBL in guinea-pig, rat, dog and pig sera, and was further investigated in the guinea-pig, in which titres were much higher (∼14-fold) than in man, and in contrast to humans, greater than classical pathway haemolytic activity. As in human serum, no lysis was observed in C4- or C2-deficient guinea-pig serum until purified C4 or C2, respectively, were restored. However, lectin pathway haemolytic activity in the guinea-pig did not require the alternative pathway. Removal (>98%) of factor D activity by three sequential passages through Sephadex G-75, resulting in serum which retained a normal classical pathway but no alternative pathway haemolytic activity, did not reduce the ability of guinea-pig serum to mediate haemolysis via the lectin pathway. Further, the C3-convertase formed via the lectin pathway (E-M-MBL-C4,2) lysed in C2-deficient guinea-pig but not human serum chelated with EDTA, a condition which precludes alternative pathway amplification. Thus, lectin pathway haemolysis occurs efficiently in guinea-pig serum, in the absence of calcium and without requirement for alternative pathway amplification. The guinea-pig provides a model for studying the assembly and haemolytic function of a lectin pathway which contrasts with the lectin pathway of man, and allows for comparisons that may help clarify the role of this pathway in complement biology. PMID:10457224

Two factors of the lectin pathway of complement, l-ficolin and mannan-binding lectin, and their associations with prematurity, low birthweight and infections in a large cohort of Polish neonates.

PubMed

Swierzko, Anna St; Atkinson, Anne P M; Cedzynski, Maciej; Macdonald, Shirley L; Szala, Agnieszka; Domzalska-Popadiuk, Iwona; Borkowska-Klos, Monika; Jopek, Aleksandra; Szczapa, Jerzy; Matsushita, Misao; Szemraj, Janusz; Turner, Marc L; Kilpatrick, David C

2009-02-01

Ficolins and one collectin, mannan-binding lectin (MBL), are the only factors known to activate the lectin pathway (LP) of complement. There is considerable circumstantial evidence that MBL insufficiency can increase susceptibility to various infections and influence the course of several non-infectious diseases complicated by infections. Much less information is available concerning l-ficolin. We report the results of a prospective study to investigate any association between either MBL deficiency or l-ficolin deficiency with prematurity, low birthweight or perinatal infections in a large cohort of Polish neonates, representing an ethnically homogenous population (n=1832). Cord blood samples were analysed to determine mbl-2 gene variants, MBL concentrations and MBL-MASP-2 complex activities (MBL-dependent lectin pathway activity) as well as l-ficolin levels. Median concentrations of l-ficolin and MBL were 2500 and 1124 ng/ml, respectively, while median LP activity was 272 mU/ml. After genotyping, 60.6% of babies were mbl-2 A/A, 35.4% were A/O and 4% were O/O genotypes. We found relative l-ficolin deficiency to be associated with prematurity, low birthweight and infections. l-Ficolin concentration correlated with gestational age and with birthweight, independently of gestational age. Preterm deliveries (<38 weeks) occurred more frequently among neonates with low LP activity but not with those having low serum MBL levels. Similarly, no association of serum MBL deficiency with low birthweight was found, but there was a correlation between LP activity and birthweight. Genotypes conferring very low serum MBL concentrations were associated with perinatal infections, and high-MBL-conferring genotypes were associated with prematurity. Our findings suggest that l-ficolin participates in host defence during the perinatal period and constitute the first evidence that relative l-ficolin deficiency may contribute to the adverse consequences of prematurity. Some similar trends

Mannose-binding lectin binds to a range of clinically relevant microorganisms and promotes complement deposition.

PubMed

Neth, O; Jack, D L; Dodds, A W; Holzel, H; Klein, N J; Turner, M W

2000-02-01

Mannose-binding lectin (MBL) is a collagenous serum lectin believed to be of importance in innate immunity. Genetically determined low levels of the protein are known to predispose to infections. In this study the binding of purified MBL to pathogens isolated from immunocompromised children was investigated by flow cytometry. Diverse Candida species, Aspergillus fumigatus, Staphylococcus aureus, and beta-hemolytic group A streptococci exhibited strong binding of MBL, whereas Escherichia coli, Klebsiella species, and Haemophilus influenzae type b were characterized by heterogeneous binding patterns. In contrast, beta-hemolytic group B streptococci, Streptococcus pneumoniae, and Staphylococcus epidermidis showed low levels of binding. Bound MBL was able to promote C4 deposition in a concentration-dependent manner. We conclude that MBL may be of importance in first-line immune defense against several important pathogens.

Low serum mannose-binding lectin as a risk factor for new onset diabetes mellitus after renal transplantation.

PubMed

Ibernon, Meritxell; Moreso, Francesc; Moreno, José M; Bestard, Oriol; Cruzado, Josep M; Grinyó, Josep M; Ricart, Wifredo; Fernández-Real, José M; Serón, Daniel

2009-07-27

Infections and new onset diabetes mellitus after transplantation (NODAT) are frequent complications after renal transplantation and may be related to innate immunity alterations. We evaluate the relationship among serum mannose-binding lectin (MBL), chronic inflammation, NODAT, and infection. Between March 2005 and October 2006, consecutive nondiabetic renal transplant recipients were recruited. MBL, soluble tumor necrosis factor receptor 2, and neutrophil gelatinase-associated lipocalin were determined before transplant and at 1 and 3 months. An oral glucose tolerance test was performed at 3 months. A total of 125 patients were recruited, and 111 patients had a functioning graft at 3 months. MBL levels remained unchanged after transplantation. Subjects with low MBL (lower tertile) had higher pretransplant soluble tumor necrosis factor receptor 2 (40+/-13 ng/mL vs. 35+/-11 ng/mL; P=0.05) and neutrophil gelatinase-associated lipocalin (638+/-114 ng/mL vs. 553+/-185 ng/mL; P=0.03), an increased incidence of bacterial/fungal infection (P=0.021), and an increased prevalence of NODAT at 3 months (44.4% vs. 22.6%; P=0.01). Multivariate analysis confirmed that MBL was a risk factor for NODAT (relative risk: 3.04, 95% confidence interval: 1.18-7.81; P=0.021) adjusting for age, pretransplant impaired fasting glucose, and body mass index. Low pretransplant MBL is associated with chronic inflammation, NODAT, and infection.

Evaluation of lectin pathway activity and mannan-binding lectin levels in the course of pregnancy complicated by diabetes type 1, based on the genetic background.

PubMed

Pertyńska Marczewska, Magdalena; Cedzyński, Maciej; Swierzko, Anna; Szala, Agnieszka; Sobczak, Małgorzata; Cypryk, Katarzyna; Wilczyński, Jan

2009-01-01

There are numerous indications that either mannan-binding lectin (MBL) deficiency or its excessive activity are associated with adverse pregnancy outcomes. High MBL concentrations and corresponding MBL2 genotypes were shown to be associated with microvascular complications in type 1 diabetes. The aim of this study was to evaluate levels of MBL and MBL-dependent activity of the lectin pathway (LP) of complement in the course of pregnancy in diabetic mothers, based on genetic background. These parameters were determined in samples from healthy non-pregnant (control), diabetic non-pregnant, healthy pregnant, and pregnant diabetic women. No significant differences in median MBL levels or LP activities were found in any study group compared to the control. However, statistically significant differences in MBL levels were noted during pregnancy between the 1st and 3rd trimesters in both healthy controls and pregnant diabetics. With regard to LP values, similar trends were evident, but statistically significant results were obtained only in the healthy pregnant group. When data analysis was confined to patients carrying the A/A (wild-type) MBL2 genotype, an increase in MBL level during pregnancy (in both healthy and diabetic pregnant women) was still observed. Similarly, LP activity increased during both healthy and diabetic pregnancies, significantly so for the former. Diabetes, an autoimmune disease, is a serious complication of pregnancy. Therefore, determination of MBL status might be beneficial in identifying type 1 diabetic patients who are at increased risk of developing both vascular complications and poor pregnancy outcomes.

Plant Lectins and Lectin Receptor-Like Kinases: How Do They Sense the Outside?

PubMed

Bellande, Kevin; Bono, Jean-Jacques; Savelli, Bruno; Jamet, Elisabeth; Canut, Hervé

2017-05-31

Lectins are fundamental to plant life and have important roles in cell-to-cell communication; development and defence strategies. At the cell surface; lectins are present both as soluble proteins (LecPs) and as chimeric proteins: lectins are then the extracellular domains of receptor-like kinases (LecRLKs) and receptor-like proteins (LecRLPs). In this review; we first describe the domain architectures of proteins harbouring G-type; L-type; LysM and malectin carbohydrate-binding domains. We then focus on the functions of LecPs; LecRLKs and LecRLPs referring to the biological processes they are involved in and to the ligands they recognize. Together; LecPs; LecRLKs and LecRLPs constitute versatile recognition systems at the cell surface contributing to the detection of symbionts and pathogens; and/or involved in monitoring of the cell wall structure and cell growth.

Changes in the levels of mannan-binding lectin and ficolins during head-down tilted bed rest.

PubMed

Kelsen, Jens; Sandahl, Thomas D; Storm, Line; Frings-Meuthen, Petra; Dahlerup, Jens F; Thiel, Steffen

2014-08-01

Spaceflight studies and ground-based analogues of microgravity indicate a weakening of human immunity. Mannan-binding lectin (MBL) and H-, L-, and M-ficolin together constitute the lectin pathway and mediate the clearance of pathogens through complement activation. We hypothesized that simulated microgravity may weaken human innate immune functions and studied the impact of 6° head-down tilted bed rest (HDT) for 21 d on MBL and ficolin levels. Within a 6-mo period, seven men underwent two periods of HDT. Blood samples were analyzed for MBL, H-, L-, and M-ficolin, mannose-binding lectin-associated protein of 44 kDa (MAp44), and collectin liver 1 (CL-L1) by time-resolved immunofluorometric assays (TRIFMA). We observed well-defined individual preintervention levels of MBL and ficolins. Remarkably similar intraindividual changes occurred for MBL and MBL levels decreased (mean 282 ng · ml⁻¹) in the recovery phase. Conversely, CL-L1, a protein with MBL-like properties, increased (mean 102 ng · ml⁻¹) during the recovery phase. M-ficolin increased (mean 79 ng · ml⁻¹) within the first 2 d of HDT, followed by a decrease (mean 112 ng · ml⁻¹) during the recovery phase. L-ficolin increased (mean 304 ng · ml⁻¹) during HDT, while H-ficolin was essentially unaffected. MAp44, a down-regulator of the lectin pathway, decreased initially (mean 78 ng · ml⁻¹) in the recovery phase followed by an increase (mean 131 ng · ml⁻¹). Alterations in MBL and ficolin levels were modest and with our current knowledge do not lead to overt immunodeficiency. Pronounced changes occurred when the subjects resumed the upright position. In selected individuals, these changes appear to be a conserved response to HDT.

Identification of polymorphisms in the bovine collagenous lectins and their association with infectious diseases in cattle.

PubMed

Fraser, R S; Lumsden, J S; Lillie, B N

2018-05-10

Infectious diseases are a significant issue in animal production systems, including both the dairy and beef cattle industries. Understanding and defining the genetics of infectious disease susceptibility in cattle is an important step in the mitigation of their impact. Collagenous lectins are soluble pattern recognition receptors that form an important part of the innate immune system, which serves as the first line of host defense against pathogens. Polymorphisms in the collagenous lectin genes have been shown in previous studies to contribute to infectious disease susceptibility, and in cattle, mutations in two collagenous lectin genes (MBL1 and MBL2) are associated with mastitis. To further characterize the contribution of variation in the bovine collagenous lectins to infectious disease susceptibility, we used a pooled NGS approach to identify short nucleotide variants (SNVs) in the collagenous lectins (and regulatory DNA) of cattle with (n = 80) and without (n = 40) infectious disease. Allele frequency analysis identified 74 variants that were significantly (p < 5 × 10 -6 ) associated with infectious disease, the majority of which were clustered in a 29-kb segment upstream of the collectin locus on chromosome 28. In silico analysis of the functional effects of all the variants predicted 11 SNVs with a deleterious effect on protein structure and/or function, 148 SNVs that occurred within potential transcription factor binding sites, and 31 SNVs occurring within potential miRNA binding elements. This study provides a detailed look at the genetic variation of the bovine collagenous lectins and identifies potential genetic markers for infectious disease susceptibility.

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-α) 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

Plant Lectins and Lectin Receptor-Like Kinases: How Do They Sense the Outside?

PubMed Central

Bellande, Kevin; Bono, Jean-Jacques; Savelli, Bruno; Jamet, Elisabeth; Canut, Hervé

2017-01-01

Lectins are fundamental to plant life and have important roles in cell-to-cell communication; development and defence strategies. At the cell surface; lectins are present both as soluble proteins (LecPs) and as chimeric proteins: lectins are then the extracellular domains of receptor-like kinases (LecRLKs) and receptor-like proteins (LecRLPs). In this review; we first describe the domain architectures of proteins harbouring G-type; L-type; LysM and malectin carbohydrate-binding domains. We then focus on the functions of LecPs; LecRLKs and LecRLPs referring to the biological processes they are involved in and to the ligands they recognize. Together; LecPs; LecRLKs and LecRLPs constitute versatile recognition systems at the cell surface contributing to the detection of symbionts and pathogens; and/or involved in monitoring of the cell wall structure and cell growth. PMID:28561754

Serum Mannose-binding Lectin in Patients on Peritoneal Dialysis Compared With Healthy Individuals.

PubMed

Akbari, Roghayeh; Najafi, Iraj; Maleki, Suzan; Alizadeh-Navaei, Reza

2016-01-01

The increased susceptibility to infection in patients with end-stage renal disease is probably secondary to the impaired immune defense in uremia. Mannose-binding lectin (MBL) has an important role in host defense through activation of the lectin complement pathway. The aim of this study was to measure serum MBL level in peritoneal dialysis patients and compare it with a healthy group. Seventy peritoneal dialysis patients and 70 healthy individuals were enrolled in this study. Serum MBL levels were measured by an enzyme-linked immunosorbent assay kit using the mannan molecule. In addition, serum C-reactive protein and albumin levels were measured to determine whether there is a correlation between serum MBL level and these two parameters. The mean serum MBL level was 2.32 ± 2.54 µg/mL (range, zero to 6.93 µg/mL) in the patients group and 1.80 ± 2.14 µg/mL (range, zero to 6.97µg/mL) in the control group (P = .19). No significant correlation was detected between age and serum MBL level in either the groups. In the patients group, no significant correlation was found between serum MBL and C-reactive protein levels or MBL and albumin levels. There were no correlation between duration of peritoneal dialysis and MBL or dialysis adequacy and MBL, either. This study did not find MBL deficiency in peritoneal dialysis patients as compared to the healthy individuals.

Labeling of lectin receptors during the cell cycle.

PubMed

Garrido, J

1976-12-01

Labeling of lectin receptors during the cell cycle. (Localizabión de receptores para lectinas durante el ciclo celular). Arch. Biol. Med. Exper. 10: 100-104, 1976. The topographic distribution of specific cell surface receptors for concanavalin A and wheat germ agglutinin was studied by ultrastructural labeling in the course of the cell cycle. C12TSV5 cells were synchronized by double thymidine block or mechanical selection (shakeoff). They were labeled by means of lectin-peroxidase techniques while in G1 S, G2 and M phases of the cycle. The results obtained were similar for both lectins employed. Interphase cells (G1 S, G2) present a stlihtly discontinous labeling pattern that is similar to the one observed on unsynchronized cells of the same line. Cells in mitosis, on the contrary, present a highly discontinous distribution of reaction product. This pattern disappears after the cells enters G1 and is not present on mitotic cells fixed in aldehyde prior to labeling.

MBL-2 polymorphisms (codon 54 and Y-221X) and low MBL levels are associated with susceptibility to multi organ dysfunction in P. falciparum malaria in Odisha, India.

PubMed

Das, Bidyut K; Panda, Aditya K

2015-01-01

Mannose binding lectin, a plasma protein protects host from virus, bacteria, and parasites. Deficiency in MBL levels has been associated with susceptibility to various infectious diseases including P. falciparum malaria. Common MBL polymorphisms in promoter and coding regions are associated with decrease in plasma MBL levels or production of deformed MBL, respectively. In the present study, we hypothesized that MBL2 variants and plasma MBL levels could be associated with different clinical phenotypes of severe P. falciparum malaria. A hospital based study was conducted in eastern Odisha, India which is endemic to P. falciparum malaria. Common MBL-2 polymorphisms (codon 54, H-550L, and Y-221X) were typed in 336 cases of severe malaria (SM) [94 cerebral malaria (CM), 120 multi-organ dysfunction (MOD), 122 non-cerebral severe malaria (NCSM)] and 131 un-complicated malaria patients (UM). Plasma MBL levels were quantified by ELISA. Severe malaria patients displayed lower plasma levels of MBL compared to uncomplicated falciparum malaria. Furthermore, on categorization of severe malaria patients into various subtypes, plasma MBL levels were very low in MOD patients compared to other categories. Higher frequency of AB genotype and allele B was observed in MOD compared to UM (AB genotype: P = 0.006; B allele: P = 0.008). In addition, prevalence of YX genotype of MBL Y-221X polymorphism was also statistically more frequent in MOD case than UM (P = 0.009). The observations of the present study reveal that MBL-2 polymorphisms (codon 54 and Y-221X) and lower plasma MBL levels are associated with increased susceptibility to multi organ dysfunctions in P. falciparum malaria.

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

Distinct Longitudinal Associations of MBL, MASP-1, MASP-2, MASP-3, and MAp44 With Endothelial Dysfunction and Intima-Media Thickness: The Cohort on Diabetes and Atherosclerosis Maastricht (CODAM) Study.

PubMed

Hertle, Elisabeth; Arts, Ilja C W; van der Kallen, Carla J H; Feskens, Edith J M; Schalkwijk, Casper G; Hoffmann-Petersen, Ingeborg T; Thiel, Steffen; Stehouwer, Coen D A; van Greevenbroek, Marleen M J

2016-06-01

Previous studies suggested that the lectin-complement pathway plays a complex role in cardiovascular disease (CVD). To date, no prospective human studies have investigated the relationship between the initiating factor of the lectin pathway, that is, mannose-binding lectin (MBL), and low-grade inflammation, endothelial dysfunction, or carotid intima-media thickness (cIMT). Moreover, MBL-associated proteases (MASPs) and MBL-associated proteins (MAps), which mediate downstream complement activation, have not been studied in the development of CVD. In a prospective cohort (n=574; age 60±7 years; 7-year follow-up), we investigated longitudinal associations of plasma MBL, MASP-1, MASP-2, MASP-3, and MAp44 with biomarker scores that reflect low-grade inflammation and endothelial dysfunction, respectively, and with cIMT. We also investigated their associations with incident CVD (n=73). In adjusted analyses, low-grade inflammation was lowest in the middle tertile (TMiddle) of MBL, that is, TMiddle was 0.19 SD (0.03 to 0.34) lower than TLow, and 0.15 SD (-0.02 to 0.31) lower than THigh. cIMT was 28 μm (-50 to -5) lower in the highest MBL tertile (THigh) than in TMiddle and did not differ between TLow and TMiddle. MBL was not associated with endothelial dysfunction or CVD. MASP-1 and MASP-2 were not associated with any cardiovascular outcomes. MASP-3 and MAp44 were, independently of MBL levels, associated with endothelial dysfunction (per 1 SD higher MASP-3: β=0.10 SD [0.02 to 0.18]; per 1 SD higher MAp44 β=0.12 SD [0.04 to 0.20]) but not with low-grade inflammation, cIMT, or CVD. High MBL may contribute to low cIMT, whereas the association of MBL with low-grade inflammation was nonlinear. MASP-1 and MASP-2 were not associated with adverse cardiovascular outcomes. MASP-3 and MAp44 may play a role in endothelial dysfunction, potentially independent of lectin-pathway activation. © 2016 American Heart Association, Inc.

Polymorphisms of Mannose-binding Lectin and Toll-like Receptors 2, 3, 4, 7 and 8 and the Risk of Respiratory Infections and Acute Otitis Media in Children.

PubMed

Toivonen, Laura; Vuononvirta, Juho; Mertsola, Jussi; Waris, Matti; He, Qiushui; Peltola, Ville

2017-05-01

Mannose-binding lectin (MBL) and toll-like receptors (TLRs) are important components of the innate immune system. We assessed the susceptibility of children with genetic variants in these factors to respiratory infections, rhinovirus infections and acute otitis media. In a prospective cohort study, blood samples from 381 Finnish children were analyzed for polymorphisms in MBL2 at codons 52, 54 and 57, TLR2 Arg753Gln, TLR3 Leu412Phe, TLR4 Asp299Gly, TLR7 Gln11Leu and TLR8 Leu651Leu. Children were followed up for respiratory infections until 24 months of age with daily diaries. Polymerase chain reaction and antigen tests were used for detection of respiratory viruses from nasal swabs. Children with MBL variant genotype had a mean of 59 days with symptoms of respiratory infection per year, compared with 49 days in those with wild-type (P = 0.01). TLR8 polymorphisms were associated with an increased risk and TLR7 polymorphisms with a decreased risk of recurrent rhinovirus infections (P = 0.02 for both). TLR2 polymorphisms were associated with recurrent acute otitis media (P = 0.02). MBL polymorphisms were associated with an increased and TLR7 polymorphisms with a decreased risk of rhinovirus-associated acute otitis media (P = 0.03 and P = 0.006, respectively). Genetic polymorphisms in MBL and TLRs promote susceptibility to or protection against respiratory infections. In addition to environmental factors, genetic variations may explain why some children are more prone to respiratory infections.

Network Analysis Reveals the Recognition Mechanism for Mannose-binding Lectins

NASA Astrophysics Data System (ADS)

Zhao, Yunjie; Jian, Yiren; Zeng, Chen; Computational Biophysics Lab Team

The specific carbohydrate binding of mannose-binding lectin (MBL) protein in plants makes it a very useful molecular tool for cancer cell detection and other applications. The biological states of most MBL proteins are dimeric. Using dynamics network analysis on molecular dynamics (MD) simulations on the model protein of MBL, we elucidate the short- and long-range driving forces behind the dimer formation. The results are further supported by sequence coevolution analysis. We propose a general framework for deciphering the recognition mechanism underlying protein-protein interactions that may have potential applications in signaling pathways.

The Lectin Pathway of Complement and Rheumatic Heart Disease

PubMed Central

Beltrame, Marcia Holsbach; Catarino, Sandra Jeremias; Goeldner, Isabela; Boldt, Angelica Beate Winter; de Messias-Reason, Iara José

2014-01-01

The innate immune system is the first line of host defense against infection and is comprised of humoral and cellular mechanisms that recognize potential pathogens within minutes or hours of entry. The effector components of innate immunity include epithelial barriers, phagocytes, and natural killer cells, as well as cytokines and the complement system. Complement plays an important role in the immediate response against microorganisms, including Streptococcus sp. The lectin pathway is one of three pathways by which the complement system can be activated. This pathway is initiated by the binding of mannose-binding lectin (MBL), collectin 11 (CL-K1), and ficolins (Ficolin-1, Ficolin-2, and Ficolin-3) to microbial surface oligosaccharides and acetylated residues, respectively. Upon binding to target molecules, MBL, CL-K1, and ficolins form complexes with MBL-associated serine proteases 1 and 2 (MASP-1 and MASP-2), which cleave C4 and C2 forming the C3 convertase (C4b2a). Subsequent activation of complement cascade leads to opsonization, phagocytosis, and lysis of target microorganisms through the formation of the membrane-attack complex. In addition, activation of complement may induce several inflammatory effects, such as expression of adhesion molecules, chemotaxis and activation of leukocytes, release of reactive oxygen species, and secretion of cytokines and chemokines. In this chapter, we review the general aspects of the structure, function, and genetic polymorphism of lectin-pathway components and discuss most recent understanding on the role of the lectin pathway in the predisposition and clinical progression of Rheumatic Fever. PMID:25654073

A novel L-ficolin/mannose-binding lectin chimeric molecule with enhanced activity against Ebola virus.

PubMed

Michelow, Ian C; Dong, Mingdong; Mungall, Bruce A; Yantosca, L Michael; Lear, Calli; Ji, Xin; Karpel, Marshall; Rootes, Christina L; Brudner, Matthew; Houen, Gunnar; Eisen, Damon P; Kinane, T Bernard; Takahashi, Kazue; Stahl, Gregory L; Olinger, Gene G; Spear, Gregory T; Ezekowitz, R Alan B; Schmidt, Emmett V

2010-08-06

Ebola viruses constitute a newly emerging public threat because they cause rapidly fatal hemorrhagic fevers for which no treatment exists, and they can be manipulated as bioweapons. We targeted conserved N-glycosylated carbohydrate ligands on viral envelope surfaces using novel immune therapies. Mannose-binding lectin (MBL) and L-ficolin (L-FCN) were selected because they function as opsonins and activate complement. Given that MBL has a complex quaternary structure unsuitable for large scale cost-effective production, we sought to develop a less complex chimeric fusion protein with similar ligand recognition and enhanced effector functions. We tested recombinant human MBL and three L-FCN/MBL variants that contained the MBL carbohydrate recognition domain and varying lengths of the L-FCN collagenous domain. Non-reduced chimeric proteins formed predominantly nona- and dodecameric oligomers, whereas recombinant human MBL formed octadecameric and larger oligomers. Surface plasmon resonance revealed that L-FCN/MBL76 had the highest binding affinities for N-acetylglucosamine-bovine serum albumin and mannan. The same chimeric protein displayed superior complement C4 cleavage and binding to calreticulin (cC1qR), a putative receptor for MBL. L-FCN/MBL76 reduced infection by wild type Ebola virus Zaire significantly greater than the other molecules. Tapping mode atomic force microscopy revealed that L-FCN/MBL76 was significantly less tall than the other molecules despite similar polypeptide lengths. We propose that alterations in the quaternary structure of L-FCN/MBL76 resulted in greater flexibility in the collagenous or neck region. Similarly, a more pliable molecule might enhance cooperativity between the carbohydrate recognition domains and their cognate ligands, complement activation, and calreticulin binding dynamics. L-FCN/MBL chimeric proteins should be considered as potential novel therapeutics.

Mannose-binding lectin 2 polymorphisms do not influence frequency or type of infection in adults with chemotherapy induced neutropaenia.

PubMed

Wong, Michelle; Öhrmalm, Lars; Broliden, Kristina; Aust, Carl; Hibberd, Martin; Tolfvenstam, Thomas

2012-01-01

Mannose-binding Lectin protein (MBL) has been suggested to be relevant in the defence against infections in immunosuppressed individuals. In a Swedish adult cohort immunosuppressed from both the underlying disease and from iatrogenic treatments for their underlying disease we investigated the role of MBL in susceptibility to infection. In this cross sectional, prospective study, blood samples obtained from 96 neutropaenic febrile episodes, representing 82 individuals were analysed for single nucleotide polymorphism (SNP) in the MBL2 gene. Concurrent measurement of plasma MBL protein concentrations was also performed for observation of acute response during febrile episodes. No association was observed between MBL2 genotype or plasma MBL concentrations, and the type or frequency of infection. Adding to the literature, we found no evidence that viral infections or co-infections with virus and bacteria would be predisposed by MBL deficiency. We further saw no correlation between MBL2 genotype and the risk of fever. However, fever duration in febrile neutropaenic episodes was negatively associated with MBL2 SNP mutations (p<0.05). Patients with MBL2 SNP mutations presented a median febrile duration of 1.8 days compared with 3 days amongst patients with wildtype MBL2 genotype. We found no clear association between infection, or infection type to MBL2 genotypes or plasma MBL concentration, and add to the reports casting doubts on the benefit of recombinant MBL replacement therapy use during iatrogenic neutropaenia.

Mannose-Binding Lectin 2 Polymorphisms Do Not Influence Frequency or Type of Infection in Adults with Chemotherapy Induced Neutropaenia

PubMed Central

Wong, Michelle; Öhrmalm, Lars; Broliden, Kristina; Aust, Carl; Hibberd, Martin; Tolfvenstam, Thomas

2012-01-01

Background Mannose-binding Lectin protein (MBL) has been suggested to be relevant in the defence against infections in immunosuppressed individuals. In a Swedish adult cohort immunosuppressed from both the underlying disease and from iatrogenic treatments for their underlying disease we investigated the role of MBL in susceptibility to infection. Methods In this cross sectional, prospective study, blood samples obtained from 96 neutropaenic febrile episodes, representing 82 individuals were analysed for single nucleotide polymorphism (SNP) in the MBL2 gene. Concurrent measurement of plasma MBL protein concentrations was also performed for observation of acute response during febrile episodes. Findings No association was observed between MBL2 genotype or plasma MBL concentrations, and the type or frequency of infection. Adding to the literature, we found no evidence that viral infections or co-infections with virus and bacteria would be predisposed by MBL deficiency. We further saw no correlation between MBL2 genotype and the risk of fever. However, fever duration in febrile neutropaenic episodes was negatively associated with MBL2 SNP mutations (p<0.05). Patients with MBL2 SNP mutations presented a median febrile duration of 1.8 days compared with 3 days amongst patients with wildtype MBL2 genotype. Interpretation We found no clear association between infection, or infection type to MBL2 genotypes or plasma MBL concentration, and add to the reports casting doubts on the benefit of recombinant MBL replacement therapy use during iatrogenic neutropaenia. PMID:22363494

Genome-wide analysis of lectin receptor-like kinases in Populus

DOE PAGES

Yang, Yongil; Labbé, Jessy; Muchero, Wellington; ...

2016-09-01

Receptor-like kinases (RLKs) belong to a large protein family with over 600 members in Arabidopsis and over 1000 in rice. Among RLKs, the lectin receptor-like kinases (LecRLKs) possess a characteristic extracellular carbohydrate-binding lectin domain and play important roles in plant development and innate immunity. In addition, there are 75 and 173 LecRLKs in Arabidopsis and rice, respectively. However, little is known about LecRLKs in perennial woody plants.

Mannose-binding lectin and its associated proteases (MASPs) mediate coagulation and its deficiency is a risk factor in developing complications from infection, including disseminated intravascular coagulation

PubMed Central

Takahashi, Kazue; Chang, Wei-Chuan; Takahashi, Minoru; Pavlov, Vasile; Ishida, Yumi; La Bonte, Laura; Shi, Lei; Fujita, Teizo; Stahl, Gregory L.; Van Cott, Elizabeth M.

2010-01-01

The first line of host defense is the innate immune system that includes coagulation factors and pattern recognition molecules, one of which is mannose-binding lectin (MBL). Previous studies have demonstrated that MBL deficiency increases susceptibility to infection. Several mechanisms are associated with increased susceptibility to infection, including reduced opsonophagocytic killing and reduced lectin complement pathway activation. In this study, we demonstrate 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 (DIC), which was associated with elevated blood IL-6 levels (but not TNF-α and multi-organ inflammatory responses). Infected MBL null mice also develop liver injury. These findings suggest that MBL deficiency may manifest into DIC and organ failure during infectious diseases. PMID:20399528

Polymorphisms in the lectin pathway of complement activation influence the incidence of acute rejection and graft outcome after kidney transplantation.

PubMed

Golshayan, Déla; Wójtowicz, Agnieszka; Bibert, Stéphanie; Pyndiah, Nitisha; Manuel, Oriol; Binet, Isabelle; Buhler, Leo H; Huynh-Do, Uyen; Mueller, Thomas; Steiger, Jürg; Pascual, Manuel; Meylan, Pascal; Bochud, Pierre-Yves

2016-04-01

There are conflicting data on the role of the lectin pathway of complement activation and its recognition molecules in acute rejection and outcome after transplantation. To help resolve this we analyzed polymorphisms and serum levels of lectin pathway components in 710 consecutive kidney transplant recipients enrolled in the nationwide Swiss Transplant Cohort Study, together with all biopsy-proven rejection episodes and 1-year graft and patient survival. Functional mannose-binding lectin (MBL) levels were determined in serum samples, and previously described MBL2, ficolin 2, and MBL-associated serine protease 2 polymorphisms were genotyped. Low MBL serum levels and deficient MBL2 diplotypes were associated with a higher incidence of acute cellular rejection during the first year, in particular in recipients of deceased-donor kidneys. This association remained significant (hazard ratio 1.75, 95% confidence interval 1.18-2.60) in a Cox regression model after adjustment for relevant covariates. In contrast, there was no significant association with rates of antibody-mediated rejection, patient death, early graft dysfunction or loss. Thus, results in a prospective multicenter contemporary cohort suggest that MBL2 polymorphisms result in low MBL serum levels and are associated with acute cellular rejection after kidney transplantation. Since MBL deficiency is a relatively frequent trait in the normal population, our findings may lead to individual risk stratification and customized immunosuppression. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

The Lectin Pathway in Thrombotic Conditions-A Systematic Review.

PubMed

Larsen, Julie Brogaard; Hvas, Christine Lodberg; Hvas, Anne-Mette

2018-06-04

The lectin pathway of the complement system can activate the coagulation system in vitro, but the role of the lectin pathway in haemostatic activation and thrombosis in vivo is not clear. We performed a systematic review of the existing literature on associations between the lectin pathway and arterial and venous thrombosis, in accordance with the Assessing the Methodological Quality of Systematic Reviews guidelines. PubMed and Embase were searched from January 1990 to March 2017. We included original studies on human study populations investigating associations between the lectin pathway (protein serum levels, genotype or gene expression) and thrombotic conditions or laboratory coagulation markers. Exclusion criteria were case studies including fewer than five cases, conference abstracts or any other language than English. In total, 43 studies were included which investigated associations between the lectin pathway and cardiovascular thrombotic events (CVEs) ( n  = 22), ischaemic stroke ( n  = 9), CVE and stroke ( n  = 1) and other conditions (systemic lupus erythematosus [ n  = 6], sepsis-related coagulopathy [ n  = 3], pulmonary embolism [ n  = 1], asparaginase treatment [ n  = 1]). Studies on the lectin pathway and CVE risk reported discrepant results, as both high and low mannose-binding lectin (MBL) serum levels were found to correlate with increased CVE risk. In ischaemic stroke patients, occurrence of stroke as well as increased stroke severity and poor outcome were consistently associated with high serum MBL. For other thromboembolic conditions, only few studies were identified. In conclusion, lectin pathway activation may negatively influence outcome after ischaemic stroke and possibly contribute to CVE risk. Further research is warranted to elucidate the role of the lectin pathway in other thrombotic conditions. Schattauer GmbH Stuttgart.

The distribution of lectin receptor sites in human breast lesions.

PubMed

Skutelsky, E; Hoenig, S; Griffel, B; Alroy, J

1988-08-01

Conflicting data regarding the status of A, B, H and T antigens in epithelium of normal, mastopathies, fibroadenomas and carcinomas of the breast stimulated us to re-examine the carbohydrate residues in these condition. Currently, we extended the number of carbohydrate residues studied by using ten different biotinylated lectins as probes and avidin-biotin-peroxidase complex (ABC) as a visualant. In addition, the pattern of lectin staining of cancerous cells in primary and metastatic sites was compared. In primary and metastatic breast carcinomas, lectin receptor sites were stained more intensely with Concanavalia ensiformi agglutinin (*Con A), Ricinus communis agglutinin-I (RCA-I) and wheat germ agglutinin (WGA), than in normal breast, in mastopathies or in fibroadenomas. Cryptic receptor sites for peanut agglutinin (PNA) were stained in all cases of breast carcinomas, while free PNA sites stained only in a few cases of well-differentiated carcinomas. Receptors sites for Ulex europaeus agglutinin-I (UEA-I) stained non-malignant epithelium of patients with blood group H but did not stain malignant cells. The results show significant differences in lectin-binding patterns and staining intensities between normal and non-malignant, and malignant epithelial breast cells. Furthermore, these results indicate that in malignant cells, there is an increased content of sialic acid-rich carbohydrates but not of asialylated glycoconjugates.

Low MBL-associated serine protease 2 (MASP-2) levels correlate with urogenital schistosomiasis in Nigerian children.

PubMed

Ojurongbe, Olusola; Antony, Justin S; Van Tong, Hoang; Meyer, Christian G; Akindele, Akeem A; Sina-Agbaje, Olawumi R; Kremsner, Peter G; Velavan, Thirumalaisamy P

2015-10-01

The human mannose-binding lectin (MBL) and ficolins (FCN) are involved in pathogen recognition in the first line of defence. They support activation of the complement lectin cascade in the presence of MBL-associated serine protease 2 (MASP-2), a protein that cleaves the C4 and C2 complement components. Recent studies found that distinct MBL2 and FCN2 promoter variants and their corresponding serum levels are associated with relative protection from urogenital schistosomiasis. We investigated the contribution of MASP-2 levels and MASP2 polymorphisms in a Nigerian study group, of 163 individuals infected with Schistosoma haematobium and 183 healthy subjects. MASP-2 serum levels varied between younger children (≤12 years) and older children (>12 years) and adults (P = 0.0001). Younger children with a patent infection had significantly lower MASP-2 serum levels than uninfected children (P = 0.0074). Older children and adults (>12 years) with a current infection had higher serum MASP-2 levels than controls (P = 0.032). MBL serum levels correlated positively with MASP-2 serum levels (P = 0.01). MASP2 secretor haplotypes were associated with MASP-2 serum levels in healthy subjects. The heterozygous MASP2 p.P126L variant was associated with reduced serum MASP-2 levels (P = 0.01). The findings indicate that higher MASP-2 serum levels are associated with relative protection from urogenital schistosomiasis in Nigerian children. © 2015 John Wiley & Sons Ltd.

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

PubMed

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

2015-12-07

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. Copyright © 2015 Elsevier B.V. All rights reserved.

Gene polymorphisms and febrile neutropenia in acute leukemia--no association with IL-4, CCR-5, IL-1RA, but the MBL-2, ACE, and TLR-4 are associated with the disease in Turkish patients: a preliminary study.

PubMed

Pehlivan, Mustafa; Sahin, Handan Haydaroğlu; Ozdilli, Kurşat; Onay, Hüseyin; Ozcan, Ali; Ozkinay, Ferda; Pehlivan, Sacide

2014-07-01

The aim of this study was to investigate the mannose-binding lectin 2 (MBL-2), interleukin (IL)-4, Toll-like receptor 4 (TLR-4), angiotensin converting enzyme (ACE), chemokine receptor 5 (CCR-5), and IL-1 receptor antagonist (RA) gene polymorphisms (GPs) in acute leukemias (ALs) and to evaluate their roles in febrile neutropenia (FN) resulting from chemotherapy. The study included 60 AL patients hospitalized between the period of July 2001 and August 2006. Polymorphisms for the genes ACE(I/D), CCR-5, IL-1RA, MBL-2, TLR-4, and IL-4 were typed by polymerase chain reaction (PCR) and/or PCR-restriction fragment length polymerase. Genotype frequencies for these genes were compared in the patient and control groups. The relationships between the genotypes and the body distribution of infections, pathogens, the duration of neutropenia, and febrile episodes in AL patients were evaluated. No significant differences in either the genotype distribution or the allelic frequencies of TLR-4, IL-4, CCR-5, IL-1RN GPs were observed between patients and healthy controls. The AB/BB genotype (53.3%) in the MBL-2 gene was found to be significantly higher in the AL patients compared with control groups. There were correlations between the presence of MBL-2, TLR-4, and ACE polymorphisms and clinical parameters due to FN. Overall, bacteremia was more common in MBL BB and ACE DD. Gram-positive bacteremia was more common in ACE for ID versus DD genotype. Gram-negative bacteremia was more common for both the MBL-2 AB/BB genotype and TLR-4 AG genotype. Median durations of febrile episodes were significantly shorter in ACE DD and MBL AB/BB. Although TLR-4, ACE, and MBL-2 GPs have been extensively investigated in different clinical pictures, this is the first study to evaluate the role of these polymorphisms in the genetic etiopathogenesis of FN in patients with ALs. As a conclusion, TLR-4, ACE, and MBL-2 genes might play roles in the genetic etiopathogenesis of FN in patients with ALs.

Recognition of DHN-melanin by a C-type lectin receptor is required for immunity to Aspergillus.

PubMed

Stappers, Mark H T; Clark, Alexandra E; Aimanianda, Vishukumar; Bidula, Stefan; Reid, Delyth M; Asamaphan, Patawee; Hardison, Sarah E; Dambuza, Ivy M; Valsecchi, Isabel; Kerscher, Bernhard; Plato, Anthony; Wallace, Carol A; Yuecel, Raif; Hebecker, Betty; da Glória Teixeira Sousa, Maria; Cunha, Cristina; Liu, Yan; Feizi, Ten; Brakhage, Axel A; Kwon-Chung, Kyung J; Gow, Neil A R; Zanda, Matteo; Piras, Monica; Zanato, Chiara; Jaeger, Martin; Netea, Mihai G; van de Veerdonk, Frank L; Lacerda, João F; Campos, António; Carvalho, Agostinho; Willment, Janet A; Latgé, Jean-Paul; Brown, Gordon D

2018-03-15

Resistance to infection is critically dependent on the ability of pattern recognition receptors to recognize microbial invasion and induce protective immune responses. One such family of receptors are the C-type lectins, which are central to antifungal immunity. These receptors activate key effector mechanisms upon recognition of conserved fungal cell-wall carbohydrates. However, several other immunologically active fungal ligands have been described; these include melanin, for which the mechanism of recognition is hitherto undefined. Here we identify a C-type lectin receptor, melanin-sensing C-type lectin receptor (MelLec), that has an essential role in antifungal immunity through recognition of the naphthalene-diol unit of 1,8-dihydroxynaphthalene (DHN)-melanin. MelLec recognizes melanin in conidial spores of Aspergillus fumigatus as well as in other DHN-melanized fungi. MelLec is ubiquitously expressed by CD31 + endothelial cells in mice, and is also expressed by a sub-population of these cells that co-express epithelial cell adhesion molecule and are detected only in the lung and the liver. In mouse models, MelLec was required for protection against disseminated infection with A. fumigatus. In humans, MelLec is also expressed by myeloid cells, and we identified a single nucleotide polymorphism of this receptor that negatively affected myeloid inflammatory responses and significantly increased the susceptibility of stem-cell transplant recipients to disseminated Aspergillus infections. MelLec therefore recognizes an immunologically active component commonly found on fungi and has an essential role in protective antifungal immunity in both mice and humans.

Role of Ficolin-A and Lectin Complement Pathway in the Innate Defense against Pathogenic Aspergillus Species

PubMed Central

Bidula, Stefan; Kenawy, Hany; Ali, Youssif M.; Sexton, Darren; Schwaeble, Wilhelm J.

2013-01-01

Aspergillus species are saprophytic molds causing life-threatening invasive fungal infections in the immunocompromised host. Innate immune recognition, in particular, the mechanisms of opsonization and complement activation, has been reported to be an integral part of the defense against fungi. We have shown that the complement component ficolin-A significantly binds to Aspergillus conidia and hyphae in a concentration-dependent manner and was inhibited by N-acetylglucosamine and N-acetylgalactosamine. Calcium-independent binding to Aspergillus fumigatus and A. terreus was observed, but binding to A. flavus and A. niger was calcium dependent. Ficolin-A binding to conidia was increased under low-pH conditions, and opsonization led to enhanced binding of conidia to A549 airway epithelial cells. In investigations of the lectin pathway of complement activation, ficolin-A-opsonized conidia did not lead to lectin pathway-specific C4 deposition. In contrast, the collectin mannose binding lectin C (MBL-C) but not MBL-A led to efficient lectin pathway activation on A. fumigatus in the absence of ficolin-A. In addition, ficolin-A opsonization led to a modulation of the proinflammatory cytokine interleukin-8. We conclude that ficolin-A may play an important role in the innate defense against Aspergillus by opsonizing conidia, immobilizing this fungus through enhanced adherence to epithelial cells and modulation of inflammation. However, it appears that other immune pattern recognition molecules, i.e., those of the collectin MBL-C, are involved in the Aspergillus-lectin complement pathway activation rather than ficolin-A. PMID:23478320

Mechanisms of Mannose-Binding Lectin-Associated Serine Proteases-1/3 Activation of the Alternative Pathway of Complement

PubMed Central

Banda, Nirmal K.; Takahashi, Minoru; Takahashi, Kazue; Stahl, Gregory L.; Hyatt, Stephanie; Glogowska, Magdalena; Wiles, Timothy A.; Endo, Yuichi; Fujita, Teizo; Holers, V. Michael; Arend, William P.

2011-01-01

Mannose-binding lectin-associated serine proteases-1/3 (MASP-1/3) are essential in activating the alternative pathway (AP) of complement through cleaving pro-factor D (pro-Df) into mature Df. MASP are believed to require binding to mannose binding lectins (MBL) or ficolins (FCN) to carry out their biological activities. Murine sera have been reported to contain MBL-A, MBL-C, and FCN-A, but not FCN-B that exists endogenously in monocytes and is thought not to bind MASP-1. We examined some possible mechanisms whereby MASP-1/3 might activate the AP. Collagen antibody-induced arthritis, a murine model of inflammatory arthritis dependent on the AP, was unchanged in mice lacking MBL-A, MBL-C, and FCN-A (MBL−/−/FCN A−/− mice) in comparison to wild-type mice. The in vitro induction of the AP by adherent mAb to collagen II was intact using sera from MBL−/−/FCN A−/− mice. Furthermore, sera from MBL−/−/FCN A−/− mice lacked pro-Df and possessed only mature Df. Gel filtration of sera from MBL−/−/FCN A−/− mice showed the presence of MASP-1 protein in fractions containing proteins smaller than the migration of MBL-A and MBL-C in sera from C4−/− mice, suggesting possible binding of MASP-1 to an unknown protein. Lastly, we show that FCN-B was present in the sera of MBL−/−/FCN A−/−mice and that it was bound to MASP-1. We conclude that MASP-1 does not require binding to MBL-A, MBL-C, or FCN-A to activate the AP. MASP-1 may cleave pro-Df into mature Df through binding to FCN-B or to an unknown protein, or may function as an unbound soluble protein. PMID:21943708

C-type lectins do not act as functional receptors for filovirus entry into cells

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

Matsuno, Keita; Nakayama, Eri; Noyori, Osamu

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 ofmore » 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.« less

High doses of recombinant mannan-binding lectin inhibit the binding of influenza A(H1N1)pdm09 virus with cells expressing DC-SIGN.

PubMed

Yu, Lei; Shang, Shiqiang; Tao, Ran; Wang, Caiyun; Zhang, Li; Peng, Hao; Chen, Yinghu

2017-07-01

The pandemic influenza A (H1N1)pdm09 virus continues to be a threat to human health. Low doses of mannan-binding lectin (MBL) (<1 μg/mL) were shown not to protect against influenza A(H1N1)pdm09 infection. However, the effect of high doses of MBL has not been investigated. Dendritic cell-specific intercellular adhesion molecule-3 grabbing non-integrin (DC-SIGN) has been proposed as an alternative receptor for influenza A(H1N1)pdm09 virus. In this study, we examined the expression of DC-SIGN on DCs as well as on acute monocytic leukemia cell line, THP-1. High doses of recombinant or human MBL inhibited binding of influenza A(H1N1)pdm09 to both these cell types in the presence of complement derived from bovine serum. Further, anti-DC-SIGN monoclonal antibody inhibited binding of influenza A(H1N1)pdm09 to both DC-SIGN-expressing DCs and THP-1 cells. This study demonstrates that high doses of MBL can inhibit binding of influenza A(H1N1)pdm09 virus to DC-SIGN-expressing cells in the presence of complement. Our results suggest that DC-SIGN may be an alternative receptor for influenza A(H1N1)pdm09 virus. © 2017 APMIS. Published by John Wiley & Sons Ltd.

Association of Mannose-Binding Lectin 2 (MBL2) gene heterogeneity and its serum concentration with osteoporosis in postmenopausal women

PubMed Central

Kiseljaković, Emina; Hasić, Sabaheta; Valjevac, Amina; Mačkić-Đurović, Mirela; Jadrić, Radivoj; Mehić, Bakir; KuCukalić-Selimović, Elma; Ibrulj, Slavka

2014-01-01

The aim of the study was to detect prevalence of MBL2 exon 1 (codons 52, 54 and 57) genetic polymorphism in postmenopausal women in Bosnia and Herzegovina and its possible role as genetic risk factor for susceptibility to occurrence of osteoporosis in this study group. Also, we investigated association between MBL serum concentrations and osteoporosis in postmenopausal women. Genetic codons’ variations were determined by PCR-RFLP and MBL in serum was measured by ELISA method in 75 postmenopausal women (37 with osteoporosis and 38 apparently healthy, non-osteoporotic women serving as a control). Serum MBL levels were not significantly different between osteoporosis and control group (492 (37-565.1) and 522.6 (477-559.4) ng/mL respectively, p=0.206). Genotype frequencies were not significantly different (p=0.997) between the studied groups of postmenopausal women. Genotype frequencies A/A, A/o and o/o in osteoporosis group were 0.576; 0.405; 0.018 and in control group 0.562; 0.412; 0.026, respectively. Frequencies of A and o allele were 0.78 and 0.22 in osteoporosis and 0.77 and 0.23 in control group. The results do not suggest association of functional polymorphism of MBL2 gene and MBL serum concentration with osteoporosis in postmenopausal females. PMID:24579967

Crystal structure of extracellular domain of human lectin-like transcript 1 (LLT1), the ligand for natural killer receptor-P1A.

PubMed

Kita, Shunsuke; Matsubara, Haruki; Kasai, Yoshiyuki; Tamaoki, Takaharu; Okabe, Yuki; Fukuhara, Hideo; Kamishikiryo, Jun; Krayukhina, Elena; Uchiyama, Susumu; Ose, Toyoyuki; Kuroki, Kimiko; Maenaka, Katsumi

2015-06-01

Emerging evidence has revealed the pivotal roles of C-type lectin-like receptors (CTLRs) in the regulation of a wide range of immune responses. Human natural killer cell receptor-P1A (NKRP1A) is one of the CTLRs and recognizes another CTLR, lectin-like transcript 1 (LLT1) on target cells to control NK, NKT and Th17 cells. The structural basis for the NKRP1A-LLT1 interaction was limitedly understood. Here, we report the crystal structure of the ectodomain of LLT1. The plausible receptor-binding face of the C-type lectin-like domain is flat, and forms an extended β-sheet. The residues of this face are relatively conserved with another CTLR, keratinocyte-associated C-type lectin, which binds to the CTLR member, NKp65. A LLT1-NKRP1A complex model, prepared using the crystal structures of LLT1 and the keratinocyte-associated C-type lectin-NKp65 complex, reasonably satisfies the charge consistency and the conformational complementarity to explain a previous mutagenesis study. Furthermore, crystal packing and analytical ultracentrifugation revealed dimer formation, which supports a complex model. Our results provide structural insights for understanding the binding modes and signal transduction mechanisms, which are likely to be conserved in the CTLR family, and for further rational drug design towards regulating the LLT1 function. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The consequence of low mannose-binding lectin plasma concentration in relation to susceptibility to Salmonella Infantis in chickens.

PubMed

Ulrich-Lynge, Sofie L; Dalgaard, Tina S; Norup, Liselotte R; Kjærup, Rikke M; Olsen, John E; Sørensen, Poul; Juul-Madsen, Helle R

2015-01-15

Mannose-binding lectin (MBL) is a key protein in innate immunity. MBL binds to carbohydrates on the surface of pathogens, where it initiates complement activation via the lectin-dependent pathway or facilitates opsonophagocytosis. In vitro studies have shown that human MBL is able to bind to Salmonella, but knowledge in relation to chicken MBL and Salmonella is lacking. In order to study this relation day-old chickens from two selected lines L10H and L10L, differing in MBL serum concentration, were either orally infected with S. Infantis (S.123443) or kept as non-infected controls. The differences between healthy L10H and L10L chicken sublines were more profound than differences caused by the S. Infantis infection. The average daily body weight was higher for L10H than for L10L, regardless of infection, indicating beneficial effects of MBL selection on growth. Salmonella was detected in cloacal swabs and the number of Salmonella positive chickens during the experiment was significantly higher in L10L than L10H, indicating that MBL may affect the magnitude of Salmonella colonisation in day-old chickens. MBL expression was determined in ceca tissue by real-time RT-PCR. L10H chickens showed a significantly higher relative expression than L10L at days 1 and 41 pi, regardless of infection. Finally, flow cytometric analysis of whole blood from infected chickens showed that L10H had a significantly higher count of all assessed leucocyte subsets on day 5 pi, and also a higher count of monocytes on day 12 pi than L10L. No difference was observed between infected and non-infected L10L chicken. Copyright © 2014 Elsevier B.V. All rights reserved.

Direct demonstration of the lectin activity of gp90MEL, a lymphocyte homing receptor

PubMed Central

1990-01-01

Considerable evidence implicates gp90MEL as a lymphocyte homing receptor mediating lymphocyte attachment to high endothelial venules of lymph nodes in mouse. The protein appears to function as a calcium- dependent, lectin-like receptor as inferred primarily by the ability of specific carbohydrates to block its function and by the presence of a calcium-type lectin domain in its primary sequence. An ELISA assay is described which provides the first demonstration that the isolated protein has lectin activity and allows a further definition of its carbohydrate specificity. In addition to the monosaccharides mannose-6- phosphate and fructose-1-phosphate, ligand activity is shown for the sulfated glycolipid, sulfatide, and for two sulfated fucose-containing polysaccharides (fucoidin and egg jelly coat) from nonmammalian sources. PMID:2202735

Intracellular Mannose Binding Lectin Mediates Subcellular Trafficking of HIV-1 gp120 in Neurons

PubMed Central

Teodorof, C; Divakar, S; Soontornniyomkij, B; Achim, CL; Kaul, M; Singh, KK

2014-01-01

Human immunodeficiency virus -1 (HIV-1) enters the brain early during infection and leads to severe neuronal damage and central nervous system impairment. HIV-1 envelope glycoprotein 120 (gp120), a neurotoxin, undergoes intracellular trafficking and transport across neurons; however mechanisms of gp120 trafficking in neurons are unclear. Our results show that mannose binding lectin (MBL) that binds to the N-linked mannose residues on gp120, participates in intravesicular packaging of gp120 in neuronal subcellular organelles and also in subcellular trafficking of these vesicles in neuronal cells. Perinuclear MBL:gp120 vesicular complexes were observed and MBL facilitated the subcellular trafficking of gp120 via the endoplasmic reticulum (ER) and Golgi vesicles. The functional carbohydrate recognition domain of MBL was required for perinuclear organization, distribution and subcellular trafficking of MBL:gp120 vesicular complexes. Nocodazole, an agent that depolymerizes the microtubule network, abolished the trafficking of MBL:gp120 vesicles, suggesting that these vesicular complexes were transported along the microtubule network. Live cell imaging confirmed the association of the MBL:gp120 complexes with dynamic subcellular vesicles that underwent trafficking in neuronal soma and along the neurites. Thus, our findings suggest that intracellular MBL mediates subcellular trafficking and transport of viral glycoproteins in a microtubule-dependent mechanism in the neurons. PMID:24825317

Effects of Mannose-Binding Lectin Polymorphisms on Irinotecan-Induced Febrile Neutropenia

PubMed Central

de Jong, Floris A.; van Schaik, Ron H.; Sparreboom, Alex; van Fessem, Marianne A.; van de Geijn, Fleur E.; van Daele, Paul L.; Verweij, Jaap; Sleijfer, Stefan; Mathijssen, Ron H.

2010-01-01

Objective. Mannose-binding lectin (MBL) is important in the innate immune response. MBL2 gene polymorphisms affect MBL expression, and genotypes yielding low MBL levels have been associated with an elevated risk for infections in hematological cancer patients undergoing chemotherapy. However, these reported associations are inconsistent, and data on patients with solid tumors are lacking. Here, we investigated the effects of MBL2 genotypes on irinotecan-induced febrile neutropenia in patients with solid tumors. Patients and Methods. Irinotecan-treated patients were genotyped for the MBL2 gene. Two promoter (−550 H/L and −221 X/Y) and three exon polymorphisms (52 A/D, 54 A/B, and 57 A/C) were determined, together with known risk factors for irinotecan-induced toxicity. Neutropenia and febrile neutropenia were recorded during the first course. Results. Of the 133 patients, 28% experienced severe neutropenia and 10% experienced febrile neutropenia. No associations were found between exon polymorphisms and febrile neutropenia. However, patients with the H/H promoter genotype, associated with high MBL levels, experienced significantly more febrile neutropenia than patients with the H/L and L/L genotypes (20% versus 13% versus 5%). Moreover, patients with the HYA haplotype encountered significantly more febrile neutropenia than patients without this high MBL-producing haplotype (16% versus 4%). In the subgroup with wild-type exon polymorphisms (A/A), patients with the high MBL promoter phenotype had the highest incidence of febrile neutropenia, regardless of known risk factors. Conclusion. Patients with high MBL2 promoter genotypes and haplotypes seem more at risk for developing febrile neutropenia. If confirmed, these preliminary findings may contribute to more individualized approaches of irinotecan treatment. PMID:20930093

Effects of mannose-binding lectin polymorphisms on irinotecan-induced febrile neutropenia.

PubMed

van der Bol, Jessica M; de Jong, Floris A; van Schaik, Ron H; Sparreboom, Alex; van Fessem, Marianne A; van de Geijn, Fleur E; van Daele, Paul L; Verweij, Jaap; Sleijfer, Stefan; Mathijssen, Ron H

2010-01-01

Mannose-binding lectin (MBL) is important in the innate immune response. MBL2 gene polymorphisms affect MBL expression, and genotypes yielding low MBL levels have been associated with an elevated risk for infections in hematological cancer patients undergoing chemotherapy. However, these reported associations are inconsistent, and data on patients with solid tumors are lacking. Here, we investigated the effects of MBL2 genotypes on irinotecan-induced febrile neutropenia in patients with solid tumors. Irinotecan-treated patients were genotyped for the MBL2 gene. Two promoter (-550 H/L and -221 X/Y) and three exon polymorphisms (52 A/D, 54 A/B, and 57 A/C) were determined, together with known risk factors for irinotecan-induced toxicity. Neutropenia and febrile neutropenia were recorded during the first course. Of the 133 patients, 28% experienced severe neutropenia and 10% experienced febrile neutropenia. No associations were found between exon polymorphisms and febrile neutropenia. However, patients with the H/H promoter genotype, associated with high MBL levels, experienced significantly more febrile neutropenia than patients with the H/L and L/L genotypes (20% versus 13% versus 5%). Moreover, patients with the HYA haplotype encountered significantly more febrile neutropenia than patients without this high MBL-producing haplotype (16% versus 4%). In the subgroup with wild-type exon polymorphisms (A/A), patients with the high MBL promoter phenotype had the highest incidence of febrile neutropenia, regardless of known risk factors. Patients with high MBL2 promoter genotypes and haplotypes seem more at risk for developing febrile neutropenia. If confirmed, these preliminary findings may contribute to more individualized approaches of irinotecan treatment.

Mannose-Binding Lectin Protein Deficiency Among Patients with Primary Immunodeficiency Disease Receiving IVIG Therapy.

PubMed

Azizi, Gholamreza; Kiaee, Fatemeh; Yaslianifard, Somaye; Rafiemanesh, Hosein; Mohammadikhajehdehi, Sara; Mohammadi, Hamed; Miresmaeeli, Seyed Sakineh; Pour, Leila H; Poor Heravi, Sina Abdolrahim; Sharifi, Laleh; Yazdani, Reza; Abolhassani, Hassan; Aghamohammadi, Asghar

2018-02-13

Primary immunodeficiencies (PIDs) are inherited disorders in which one or several components of the immune system are defective. Immunoglobulin replacement therapy is the mainstay of treatment for patients with impaired antibody production. However, recurrent infections would continue to occur in some patients due to the other high frequent concomitant defects, such as mannose-binding lectin (MBL) deficiency. A total of 51 PID patients participated in this cross-sectional study. A detailed questionnaire was completed by interviewing patients in order to record demographic, clinical and laboratory data. The levels of MBL were determined in the serums of patients by a sandwich enzyme-linked immunosorbent assay (ELISA) technique. MBL deficiency was found in 29.4% of cases; 11.8% patients had mild, 3.9% patients had moderate and 13.7% patients had severe MBL deficiency. In patients with MBL deficiency, the rate of meningitis, sepsis, pneumonia, and otitis media was higher than patients with normal MBL levels. Immunoglobulin replacement therapy reduced the rate of infectious complications in PID patients; however, these reductions were more apparent in patients with normal MBL levels than patients with MBL deficiency. Antibody deficient patients with a concomitant immune defect in MBL production have higher rates of recurrent infections despite receiving Immunoglobulin replacement therapy. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

A lectin receptor kinase as a potential sensor for extracellular nicotinamide adenine dinucleotide in Arabidopsis thaliana

PubMed Central

Wang, Chenggang; Zhou, Mingqi; Zhang, Xudong; Yao, Jin; Zhang, Yanping; Mou, Zhonglin

2017-01-01

Nicotinamide adenine dinucleotide (NAD+) participates in intracellular and extracellular signaling events unrelated to metabolism. In animals, purinergic receptors are required for extracellular NAD+ (eNAD+) to evoke biological responses, indicating that eNAD+ may be sensed by cell-surface receptors. However, the identity of eNAD+-binding receptors still remains elusive. Here, we identify a lectin receptor kinase (LecRK), LecRK-I.8, as a potential eNAD+ receptor in Arabidopsis. The extracellular lectin domain of LecRK-I.8 binds NAD+ with a dissociation constant of 436.5 ± 104.8 nM, although much higher concentrations are needed to trigger in vivo responses. Mutations in LecRK-I.8 inhibit NAD+-induced immune responses, whereas overexpression of LecRK-I.8 enhances the Arabidopsis response to NAD+. Furthermore, LecRK-I.8 is required for basal resistance against bacterial pathogens, substantiating a role for eNAD+ in plant immunity. Our results demonstrate that lectin receptors can potentially function as eNAD+-binding receptors and provide direct evidence for eNAD+ being an endogenous signaling molecule in plants. DOI: http://dx.doi.org/10.7554/eLife.25474.001 PMID:28722654

Mannose Binding Lectin Is Required for Alphavirus-Induced Arthritis/Myositis

PubMed Central

Whitmore, Alan C.; Blevins, Lance K.; Hueston, Linda; Fraser, Robert J.; Herrero, Lara J.; Ramirez, Ruben; Smith, Paul N.; Mahalingam, Suresh; Heise, Mark T.

2012-01-01

Mosquito-borne alphaviruses such as chikungunya virus and Ross River virus (RRV) are emerging pathogens capable of causing large-scale epidemics of virus-induced arthritis and myositis. The pathology of RRV-induced disease in both humans and mice is associated with induction of the host inflammatory response within the muscle and joints, and prior studies have demonstrated that the host complement system contributes to development of disease. In this study, we have used a mouse model of RRV-induced disease to identify and characterize which complement activation pathways mediate disease progression after infection, and we have identified the mannose binding lectin (MBL) pathway, but not the classical or alternative complement activation pathways, as essential for development of RRV-induced disease. MBL deposition was enhanced in RRV infected muscle tissue from wild type mice and RRV infected MBL deficient mice exhibited reduced disease, tissue damage, and complement deposition compared to wild-type mice. In contrast, mice deficient for key components of the classical or alternative complement activation pathways still developed severe RRV-induced disease. Further characterization of MBL deficient mice demonstrated that similar to C3−/− mice, viral replication and inflammatory cell recruitment were equivalent to wild type animals, suggesting that RRV-mediated induction of complement dependent immune pathology is largely MBL dependent. Consistent with these findings, human patients diagnosed with RRV disease had elevated serum MBL levels compared to healthy controls, and MBL levels in the serum and synovial fluid correlated with severity of disease. These findings demonstrate a role for MBL in promoting RRV-induced disease in both mice and humans and suggest that the MBL pathway of complement activation may be an effective target for therapeutic intervention for humans suffering from RRV-induced arthritis and myositis. PMID:22457620

Reactive arthritis and serum levels of mannose binding lectin – lack of association

PubMed Central

LOCHT, H; CHRISTIANSEN, M; LAURSEN, I

2003-01-01

The purpose was to evaluate the possible association of serum mannose binding lectin (s-MBL) levels on type of triggering microbe, duration of diarrhoea, incidence and course of reactive arthritis (ReA) caused by Salmonella, Yersinia and Campylobacter. Sixty patients with ReA of 1–228 months duration, 173 patients with ReA or uncomplicated enterocolitis caused by Campylobacter, 226 sera from patients with elevated antibody levels against Salmonella, Yersinia or Campylobacter, and 114 blood donors were tested for s-MBL using ELISA technique, both direct mannan binding assay and sandwich ELISA. s-MBL was compared with C-reactive protein (CRP) levels and with the ability of activating complement C4. Among the 114 donors 9% had s-MBL <50 µg/l, 16% had from 50–500 µg/l and 75% had >500 µg/l. The distribution of s-MBL levels in the three-patient groups did not differ significantly from the controls. There were no indications that low s-MBL was associated with prolonged duration of arthritis, diarrhoea or individual bacterial infections. The two MBL assays were comparable with respect to serum concentrations, indicating that the actual circulating MBL was also functionally active. s-MBL exhibited acute phase reactant behaviour and correlated to CRP level, but only in patients with s-MBL concentrations exceeding 1000 µg/l. MBL in 10 randomly selected ReA sera were tested for the ability to activate complement C4. The results did not differ from those of donor controls. This study demonstrates that the distributions of s-MBL levels in serum among patients with ReA are not different from donor controls. The course, outcome or triggering bacteria are not associated with a particular level of s-MBL. PMID:12519401

Intracellular mannose binding lectin mediates subcellular trafficking of HIV-1 gp120 in neurons.

PubMed

Teodorof, C; Divakar, S; Soontornniyomkij, B; Achim, C L; Kaul, M; Singh, K K

2014-09-01

Human immunodeficiency virus-1 (HIV-1) enters the brain early during infection and leads to severe neuronal damage and central nervous system impairment. HIV-1 envelope glycoprotein 120 (gp120), a neurotoxin, undergoes intracellular trafficking and transport across neurons; however mechanisms of gp120 trafficking in neurons are unclear. Our results show that mannose binding lectin (MBL) that binds to the N-linked mannose residues on gp120, participates in intravesicular packaging of gp120 in neuronal subcellular organelles and also in subcellular trafficking of these vesicles in neuronal cells. Perinuclear MBL:gp120 vesicular complexes were observed and MBL facilitated the subcellular trafficking of gp120 via the endoplasmic reticulum (ER) and Golgi vesicles. The functional carbohydrate recognition domain of MBL was required for perinuclear organization, distribution and subcellular trafficking of MBL:gp120 vesicular complexes. Nocodazole, an agent that depolymerizes the microtubule network, abolished the trafficking of MBL:gp120 vesicles, suggesting that these vesicular complexes were transported along the microtubule network. Live cell imaging confirmed the association of the MBL:gp120 complexes with dynamic subcellular vesicles that underwent trafficking in neuronal soma and along the neurites. Thus, our findings suggest that intracellular MBL mediates subcellular trafficking and transport of viral glycoproteins in a microtubule-dependent mechanism in the neurons. Published by Elsevier Inc.

Circulating mannan-binding lectin, M-, L-, H-ficolin and collectin-liver-1 levels in patients with acute liver failure.

PubMed

Laursen, Tea L; Sandahl, Thomas D; Støy, Sidsel; Schiødt, Frank V; Lee, William M; Vilstrup, Hendrik; Thiel, Steffen; Grønbaek, Henning

2015-03-01

The complement system is activated in liver diseases including acute liver failure (ALF); however, the role of the lectin pathway of complement has scarcely been investigated in ALF. The pathway is initiated by soluble pattern recognition molecules: mannan-binding lectin (MBL), M-, L-, and H-ficolin and collectin-liver-1 (CL-L1), which are predominantly synthesized in the liver. We aimed to study lectin levels in ALF patients and associations with clinical outcome. Serum samples from 75 patients enrolled by the US ALF Study Group were collected on days 1 and 3. We included 75 healthy blood donors and 20 cirrhosis patients as controls. Analyses were performed using sandwich-type immunoassays (ELISA, TRIFMA). At day 1, the MBL level in ALF patients was 40% lower compared with healthy controls {[median (interquartile range) 0.72 μg/ml(0.91) vs. 1.15 (1.92)(P = 0.02]}, and increased significantly by day 3 [0.83 μg/ml(0.94)(P = 0.01)]. The M-ficolin level was 60% lower [0.54 μg/ml(0.50) vs. 1.48(1.01)(P < 0.0001)]. The CL-L1 level at day 1 was slightly higher compared with healthy controls [3.20 μg/ml(2.37) vs. 2.64(0.72)(P = 0.11)]; this was significant at day 3 [3.35(1.84)(P = 0.006)]. H- and L-ficolin levels were similar to healthy controls. Spontaneous ALF survivors had higher levels of MBL at day 1 [0.96 μg/ml(1.15) vs. 0.60(0.60)(P = 0.02)] and lower levels of L-ficolin by day 3 compared with patients who died or were transplanted [1.61 μg/ml(1.19) vs. 2.17(2.19)(P = 0.02)]. We observed significant dynamics in lectin levels in ALF patients, which may suggest they play a role in ALF pathogenesis. High MBL and low L-ficolin levels are associated with survival. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Mannose-Binding Lectin Deficiency Facilitates Abdominal Candida Infections in Patients with Secondary Peritonitis▿

PubMed Central

van Till, J. W. Olivier; Modderman, Piet W.; de Boer, Martin; Hart, Margreet H. L.; Beld, Marcel G. H. M.; Boermeester, Marja A.

2008-01-01

Mannose-binding lectin (MBL) deficiency due to variations in the MBL gene is associated with increased susceptibility to infections. In this study, the association between MBL deficiency and the occurrence of abdominal yeast infection (AYI) in peritonitis patients was examined. Eighty-eight patients with secondary peritonitis requiring emergency laparotomy were included. MBL genotype (wild type [WT] versus patients with variant genotypes), MBL plasma concentrations, and Candida risk factors were examined in patients with and those without AYI (positive abdominal yeast cultures during [re]laparotomy). A variant MBL genotype was found in 53% of patients with AYI and 38% of those without AYI (P = 0.18). A significantly higher proportion of variant patients had an AYI during early peritonitis (during first laparotomy) than WT patients (39% versus 16%, respectively; P = 0.012). Patients with AYI had lower MBL levels than did patients without AYI (0.16 μg/ml [0.0 to 0.65 μg/ml] versus 0.65 μg/ml (0.19 to 1.95 μg/ml); P = 0.007). Intensity of colonization (odds ratio [OR], 1.1; 95% confidence interval [CI], 1.0 to 1.1), MBL plasma concentrations of <0.5 μg/ml (OR, 4.5; 95% CI, 1.2 to 16.3), and numbers of relaparotomies (OR, 1.7; 95% CI, 1.0 to 2.8) were independently associated with AYI. In summary, deficient MBL plasma levels were independently associated with the development of AYI in patients with secondary peritonitis and seemed to facilitate early infection. PMID:17978009

Innate immune response of channel catfish (Ictalurus punctatus) mannose-binding lectin to channel catfish virus

USDA-ARS?s Scientific Manuscript database

The channel catfish virus (CCV) is a pathogenic herpesvirus that infects channel catfish (Ictalurus punctatus) in pond aquaculture in the Southeast USA. The innate immune protein mannose-binding lectin (MBL) could play an important role in the innate response of channel catfish by binding to the CC...

Identification of natural killer cell receptor clusters in the platypus genome reveals an expansion of C-type lectin genes.

PubMed

Wong, Emily S W; Sanderson, Claire E; Deakin, Janine E; Whittington, Camilla M; Papenfuss, Anthony T; Belov, Katherine

2009-08-01

Natural killer (NK) cell receptors belong to two unrelated, but functionally analogous gene families: the immunoglobulin superfamily, situated in the leukocyte receptor complex (LRC) and the C-type lectin superfamily, located in the natural killer complex (NKC). Here, we describe the largest NK receptor gene expansion seen to date. We identified 213 putative C-type lectin NK receptor homologs in the genome of the platypus. Many have arisen as the result of a lineage-specific expansion. Orthologs of OLR1, CD69, KLRE, CLEC12B, and CLEC16p genes were also identified. The NKC is split into at least two regions of the genome: 34 genes map to chromosome 7, two map to a small autosome, and the remainder are unanchored in the current genome assembly. No NK receptor genes from the LRC were identified. The massive C-type lectin expansion and lack of Ig-domain-containing NK receptors represents the most extreme polarization of NK receptors found to date. We have used this new data from platypus to trace the possible evolutionary history of the NK receptor clusters.

Mild and moderate Mannose Binding Lectin deficiency are associated with systemic lupus erythematosus and lupus nephritis in Brazilian patients.

PubMed

Perazzio, Sandro Félix; Silva, Neusa Pereira da; Carneiro-Sampaio, Magda; Andrade, Luis Eduardo Coelho

2016-01-01

The potential association of mannose binding lectin (MBL) deficiency and systemic lupus erythematosus (SLE) has been investigated in several studies, but results have been mixed. One explanation for the conflicting results could be differences in ethnic background of study subjects. In this study we investigated the association of MBL deficiency and SLE in a large cohort of Brazilian SLE patients and controls. Serum MBL and Complement levels were determined for 286 Brazilian adult SLE patients and 301 healthy Brazilian adults as controls. MBL deficiency was classified as mild (<1000 and ≥500μg/L), moderate (<500 and ≥100μg/L) or severe (<100μg/L). SLE patients presented higher frequency of mild and moderate MBL deficiency compared to controls. SLE patients with MBL deficiency presented higher frequency of lupus nephritis compared to those without MBL deficiency. MBL deficiency was not associated with any other clinical manifestation, use of immunosuppressant therapy, disease activity, disease severity serum or Complement levels. This study shows that an association between MBL deficiency and SLE does exist in the Brazilian population. We also found an association between MBL deficiency and lupus nephritis. These findings support the hypothesis that MBL deficiency contributes to the development of SLE and lupus nephritis. Copyright © 2015 Elsevier Editora Ltda. All rights reserved.

C-Type Lectin Receptor MCL Facilitates Mincle Expression and Signaling through Complex Formation.

PubMed

Miyake, Yasunobu; Masatsugu, Oh-hora; Yamasaki, Sho

2015-06-01

C-type lectin receptors expressed in APCs are recently defined pattern recognition receptors that play a crucial role in immune responses against pathogen-associated molecular patterns. Among pathogen-associated molecular patterns, cord factor (trehalose-6,6'-dimycolate [TDM]) is the most potent immunostimulatory component of the mycobacterial cell wall. Two C-type lectin receptors, macrophage-inducible C-type lectin (Mincle) and macrophage C-type lectin (MCL), are required for immune responses against TDM. Previous studies indicate that MCL is required for TDM-induced Mincle expression. However, the mechanism by which MCL induces Mincle expression has not been fully understood. In this study, we demonstrate that MCL interacts with Mincle to promote its surface expression. After LPS or zymosan stimulation, MCL-deficient bone marrow-derived dendritic cells (BMDCs) had a lower level of Mincle protein expression, although mRNA expression was comparable with wild-type BMDCs. Meanwhile, BMDCs from MCL transgenic mice showed an enhanced level of Mincle expression on the cell surface. MCL was associated with Mincle through the stalk region and this region was necessary and sufficient for the enhancement of Mincle expression. This interaction appeared to be mediated by the hydrophobic repeat of MCL, as substitution of four hydrophobic residues within the stalk region with serine (MCL(4S)) abolished the function to enhance the surface expression of Mincle. MCL(4S) mutant failed to restore the defective TDM responses in MCL-deficient BMDCs. These results suggest that MCL positively regulates Mincle expression through protein-protein interaction via its stalk region, thereby magnifying Mincle-mediated signaling. Copyright © 2015 by The American Association of Immunologists, Inc.

Subclinical rejection in renal transplants is associated with low serum mannose-binding lectin levels.

PubMed

Ibernon, Meritxell; Moreso, Francesc; Serón, Daniel

2011-08-01

Surveillance biopsies have contributed to the understanding of the natural history of renal allograft lesions. Subclinical rejection, defined as the presence of histological lesions, indistinguishable from acute rejection in stable grafts, is associated with progression of interstitial fibrosis and tubular atrophy. The prevalence of subclinical rejection has decreased as more powerful immunosuppressive treatments have been introduced, suggesting that subclinical rejection represents the degree of control of the alloimmune response. However, non-immune factors such as donor age are also associated with the prevalence of subclinical rejection, suggesting that kidneys from older donors are more susceptible to insult and have a reduced capacity for tissue regeneration. Innate immunity has a crucial role in the modulation of the inflammatory response during infection and tissue damage. Mannose-binding lectin (MBL) is an innate immune protein, the polymorphisms of which are associated with infection, low-grade inflammation, diabetes, and cardiovascular disease. However, the relationship between MBL and disease is complex. For example, low MBL level is associated with higher risk for diabetes, whereas in patients with diabetes, high MBL level is associated with more severe renal damage. In renal transplant patients, low MBL levels are associated with an increased prevalence of infection and diabetes, whereas high MBL levels are associated with shortened graft survival. Although MBL is not clearly associated with prevalence of acute rejection, surveillance biopsy studies have shown that low MBL levels are associated with subclinical rejection in kidney and the heart, suggesting that MBL modulates the injury-repair process of the allograft.

Subclinical rejection in renal transplants is associated with low serum mannose-binding lectin levels

PubMed Central

Ibernon, Meritxell; Moreso, Francesc; Serón, Daniel

2011-01-01

Surveillance biopsies have contributed to the understanding of the natural history of renal allograft lesions. Subclinical rejection, defined as the presence of histological lesions, indistinguishable from acute rejection in stable grafts, is associated with progression of interstitial fibrosis and tubular atrophy. The prevalence of subclinical rejection has decreased as more powerful immunosuppressive treatments have been introduced, suggesting that subclinical rejection represents the degree of control of the alloimmune response. However, non-immune factors such as donor age are also associated with the prevalence of subclinical rejection, suggesting that kidneys from older donors are more susceptible to insult and have a reduced capacity for tissue regeneration. Innate immunity has a crucial role in the modulation of the inflammatory response during infection and tissue damage. Mannose-binding lectin (MBL) is an innate immune protein, the polymorphisms of which are associated with infection, low-grade inflammation, diabetes, and cardiovascular disease. However, the relationship between MBL and disease is complex. For example, low MBL level is associated with higher risk for diabetes, whereas in patients with diabetes, high MBL level is associated with more severe renal damage. In renal transplant patients, low MBL levels are associated with an increased prevalence of infection and diabetes, whereas high MBL levels are associated with shortened graft survival. Although MBL is not clearly associated with prevalence of acute rejection, surveillance biopsy studies have shown that low MBL levels are associated with subclinical rejection in kidney and the heart, suggesting that MBL modulates the injury–repair process of the allograft. PMID:25018901

No strong relationship between mannan binding lectin or plasma ficolins and chemotherapy-related infections

PubMed Central

KILPATRICK, D C; MCLINTOCK, L A; ALLAN, E K; COPLAND, M; FUJITA, T; JORDANIDES, N E; KOCH, C; MATSUSHITA, M; SHIRAKI, H; STEWART, K; TSUJIMURA, M; TURNER, M L; FRANKLIN, I M; HOLYOAKE, T L

2003-01-01

Chemotherapy causes neutropenia and an increased susceptibility to infection. Recent reports indicate that mannan-binding lectin (MBL) insufficiency is associated with an increased duration of febrile neutropenia and incidence of serious infections following chemotherapy for haematological malignancies. We aimed to confirm or refute this finding and to extend the investigation to the plasma ficolins, P35 (L-ficolin) and the Hakata antigen (H-ficolin). MBL, L-ficolin and H-ficolin were measured in 128 patients with haematological malignancies treated by chemotherapy alone or combined with bone marrow transplantation. Protein concentrations were related to clinical data retrieved from medical records. MBL concentrations were elevated compared with healthy controls in patients who received chemotherapy, while L-ficolin concentrations were decreased and H-ficolin levels were unchanged. There was no correlation between MBL, L-ficolin or H-ficolin concentration and febrile neutropenia expressed as the proportion of neutropenic periods in which patients experienced fever, and there was no relation between abnormally low (deficiency) levels of MBL, L-ficolin or H-ficolin and febrile neutropenia so expressed. Patients with MBL ≤ 0·1 µg/ml had significantly more major infections than no infections within the follow-up period (P < 0·05), but overall most patients had signs or symptoms of minor infections irrespective of MBL concentration. Neither L-ficolin nor H-ficolin deficiencies were associated with infections individually, in combination or in combination with MBL deficiency. MBL, L-ficolin and H-ficolin, independently or in combination, did not have a major influence on susceptibility to infection in these patients rendered neutropenic by chemotherapy. These results cast doubt on the potential value of MBL replacement therapy in this clinical context. PMID:14616788

[Lectins, adhesins, and lectin-like substances of lactobacilli and bifidobacteria].

PubMed

Lakhtin, V M; Aleshkin, V A; Lakhtin, M V; Afanas'ev, S S; Pospelova, V V; Shenderov, B A

2006-01-01

Cell-surface adhesion factors of lactobacilli and bifidobacteria, such as lectin/adhesin proteins of S-layers, secreted lectin-like bacteriocins, and lectin-like complexes, are considered and classified in the article. Certain general and specific properties of these factors are noted, such as in vitro and in vivo adhesion, cell co(aggregation), participation in the forming of microbial biofilms and colonization of mammalian alimentary tract, as well as complexation with biopolymers and bioeffectors, specificity to glycanes and natural glycoconjugates, domain and spatial organization of adhesion factors, co-functioning with other cytokines (pro- and anti-inflammatory ones), regulation of target cell properties, and other biological and physiological activities. The authors also note possibilities of application of lectins and lectin-like proteins of probiotic strains of lactobacilli and bifidobacteria in medicine and biotechnology.

[Effect of thyroid hormones on the histotopography of lectin receptors in the rat salivary gland].

PubMed

Lutsik, A D; Iashchenko, A M; Detiuk, E S

1987-04-01

Using lectin-peroxidase technique, the influence of hypo- and hyperthyroidism on histotopography of glycoconjugates has been investigated in rat submandibular gland. The following lectins were used: peanut agglutinin (PNA), wheat germ agglutinin (WGA), Laburnum anagyroides lectin (LAL) and concanavalin A (con A). It has been demonstrated that hyperthyroidism is accompanied by the loss of con A, WGA and LAL receptor sites. Hypothyrodism enhanced con A binding to granular duct cells with a parallel reduction in WGA and LAL binding to these or other duct cells. Hypothyroidism as well as hyperthyroidism markedly enhanced PNA binding to duct epitheliocytes with redistribution of these lectin binding sites from the luminal surface of salivary ducts into the cytoplasm of duct cells. Possible interpretations of the observed phenomena are discussed.

Association study between mannose-binding lectin haplotypes and X gene mutation of hepatitis B virus from treatment naïve patients.

PubMed

Su, Chenghao; Lin, Yong; Mao, Qianguo; Wu, Daitze; Zhu, Lina; Najera, Isabel; Garcia-Alcalde, Fernando; Niu, Jianjun

2016-11-07

Mannose binding lectin (MBL) plays important role in the innate immunity of human. Mutations in the MBL2 gene can significantly change the serum level of MBL, and consequently alter the susceptibility and progression of infectious disease. However, the association between the MBL2 profile and the HBV mutation and quasispecies complexity has not yet been reported. Our approach includes the study of the MBL2 gene genotype as well as ultra-deep sequencing of the HBV viruses obtained from the plasma of 50 treatment naïve patients with chronic HBV infection. We found that the liver function was better among patients within the high MBL2 group with respect to those within the medium/low MBL2 group. Likewise, the number of mutations in the HBV X gene as well as the viral quasispecies complexity were significantly higher in medium/low MBL2 production group. Nucleotide substitution rates were also higher within the medium/low MBL2 production group in all positions described to have an influence in liver cancer development, except for A1499G. In this work we show that the MBL2 profile may have an impact on the HBV X gene mutations as well as on viral quasispecies complexity.

Anti-Retroviral Lectins Have Modest Effects on Adherence of Trichomonas vaginalis to Epithelial Cells In Vitro and on Recovery of Tritrichomonas foetus in a Mouse Vaginal Model

PubMed Central

Chatterjee, Aparajita; Ratner, Daniel M.; Ryan, Christopher M.; Johnson, Patricia J.; O’Keefe, Barry R.; Secor, W. Evan; Anderson, Deborah J.; Robbins, Phillips W.; Samuelson, John

2015-01-01

Trichomonas vaginalis causes vaginitis and increases the risk of HIV transmission by heterosexual sex, while Tritrichomonas foetus causes premature abortion in cattle. Our goals were to determine the effects, if any, of anti-retroviral lectins, which are designed to prevent heterosexual transmission of HIV, on adherence of Trichomonas to ectocervical cells and on Tritrichomonas infections in a mouse model. We show that Trichomonas Asn-linked glycans (N-glycans), like those of HIV, bind the mannose-binding lectin (MBL) that is part of the innate immune system. N-glycans of Trichomonas and Tritrichomonas bind anti-retroviral lectins (cyanovirin-N and griffithsin) and the 2G12 monoclonal antibody, each of which binds HIV N-glycans. Binding of cyanovirin-N appears to be independent of susceptibility to metronidazole, the major drug used to treat Trichomonas. Anti-retroviral lectins, MBL, and galectin-1 cause Trichomonas to self-aggregate and precipitate. The anti-retroviral lectins also increase adherence of ricin-resistant mutants, which are less adherent than parent cells, to ectocervical cell monolayers and to organotypic EpiVaginal tissue cells. Topical application of either anti-retroviral lectins or yeast N-glycans decreases by 40 to 70% the recovery of Tritrichomonas from the mouse vagina. These results, which are explained by a few simple models, suggest that the anti-retroviral lectins have a modest potential for preventing or treating human infections with Trichomonas. PMID:26252012

Expression of C-type lectin receptor mRNA in chronic otitis media with cholesteatoma.

PubMed

Kim, Sang Hoon; Han, Seung-Ho; Byun, Jae Yong; Park, Moon Suh; Kim, Young Il; Yeo, Seung Geun

2017-06-01

The levels of expression of various C-type lectin receptors (CLRs) messenger ribo nucleic acids (mRNAs) were significantly higher in cholesteatomas than in normal skin, suggesting that these CLRs may be involved in the pathogenesis of cholesteatoma. Altered expression of pattern recognition receptors may be associated with immune responses in patients with cholesteatoma. This study assessed the levels of expression of CLR mRNAs in normal skin and in cholesteatoma. Cholesteatoma specimens were obtained from 38 patients with acquired cholesteatoma. The levels of expression of various CLR mRNAs were assessed quantitatively using real-time RT-PCR (Reverse transcription polymerase chain reaction) and correlated with age, sex, the presence of bacteria, hearing level, frequency of surgery, and degree of ossicle destruction. The levels of CD206 (cluster of differentiation 206), DEC-205 (Dendritic and epithelial cell-205), MGL (monoacylglycerol lipase), CLEC5A (C-type lectin domain family 5 member A), Dectin-2 (dendrite cell-associated C-type lectin-2), BDCA2 (Blood dendritic cell antigen 2), Mincle, DCIR (dendritic cell immunoreceptor), Dectin-1, MICL (Myeloid inhibitory C type-like lectin), and CLEC12B (C-type lectin domain family 12, member B) mRNAs were significantly higher in cholesteatoma than in control skin samples (p < 0.05). The levels of CLEC5A (C-type lectin domain family 5 member) and Dectin-1 mRNAs were significantly higher in cholesteatomas with ≥2 than ≤1 destroyed ossicles (p < 0.05), and the levels of MGL, Mincle, Dectin-1, and CLEC12B mRNAs were significantly higher in recurrent than initial cholesteatoma specimens (p < 0.05). The level of CLEC5A mRNAs was significantly higher in patients with severe than mild-to-moderate hearing loss (p < 0.05).

Association of Lectin Pathway Protein Levels and Genetic Variants Early after Injury with Outcomes after Severe Traumatic Brain Injury: A Prospective Cohort Study.

PubMed

Osthoff, Michael; Walder, Bernhard; Delhumeau, Cécile; Trendelenburg, Marten; Turck, Natacha

2017-09-01

The lectin pathway of the complement system has been implicated in secondary ischemic/inflammatory injury after traumatic brain injury (TBI). However, previous experimental studies have yielded conflicting results, and human studies are scarce. In this exploratory study, we investigated associations of several lectin pathway proteins early after injury and single-nucleotide polymorphisms (SNP) with outcomes after severe TBI (mortality at 14 days [primary outcome] and consciousness assessed with the Glasgow Coma Scale [GCS] at 14 days, disability assessed with the Glasgow Outcome Scale Extended [GOSE] at 90 days). Forty-four patients with severe TBI were included. Plasma levels of lectin pathway proteins were sampled at 6, 12, 24, and 48 h after injury and eight mannose-binding lectin (MBL) and ficolin (FCN)2 SNPs were analyzed by enzyme-linked immunosorbent assay (ELISA) and genotyping, respectively. Plasma protein levels were stable with only a slight increase in mannose-binding protein-associated serine protease (MASP)-2 and FCN2 levels after 48 h (p < 0.05), respectively. Neither lectin protein plasma levels (6 h or mean levels) nor MBL2 genotypes or FCN2 variant alleles were associated with 14 day mortality or 14 day consciousness. However, FCN2, FCN3, and MASP-2 levels were higher in patients with an unfavorable outcome (GOSE 1-4) at 90 days (p < 0.05), whereas there was no difference in MBL2 genotypes or FCN2 variant alleles. In particular, higher mean MASP-2 levels over 48 h were independently associated with a GOSE score < 4 at 90 days after adjustment (odds ratio 3.46 [95% confidence interval 1.12-10.68] per 100 ng/mL increase, p = 0.03). No association was observed between the lectin pathway of the complement system and 14 day mortality or 14 day consciousness. However, higher plasma FCN2, FCN3, and, in particular, MASP-2 levels early after injury were associated with an unfavorable outcome at 90 days (death, vegetative state, and

Deficiency of Mannose-Binding Lectin Greatly Increases Susceptibility to Postburn Infection with Pseudomonas aeruginosa1

PubMed Central

Møller-Kristensen, Mette; Eddie Ip, W. K.; Shi, Lei; Gowda, Lakshmi D.; Hamblin, Michael R.; Thiel, Steffen; Jensenius, Jens Chr.; Ezekowitz, R. Alan B.; Takahashi, Kazue

2011-01-01

Burn injury disrupts the mechanical and biological barrier that the skin presents against infection by symbionts like the Pseudomonas aeruginosa, a Gram-negative bacteria. A combination of local factors, antimicrobial peptides, and resident effector cells form the initial response to mechanical injury of the skin. This activity is followed by an inflammatory response that includes influx of phagocytes and serum factors, such as complement and mannose-binding lectin (MBL), which is a broad-spectrum pattern recognition molecule that plays a key role in innate immunity. A growing consensus from studies in humans and mice suggests that lack of MBL together with other comorbid factors predisposes the host to infection. In this study we examined whether MBL deficiency increases the risk of P. aeruginosa infection in a burned host. We found that both wild-type and MBL null mice were resistant to a 5% total body surface area burn alone or s.c. infection with P. aeruginosa alone. However, when mice were burned then inoculated s.c. with P. aeruginosa at the burn site, all MBL null mice died by 42 h from septicemia, whereas only one-third of wild-type mice succumbed (p = 0.0005). This result indicates that MBL plays a key role in containing and preventing a systemic spread of P. aeruginosa infection following burn injury and suggests that MBL deficiency in humans maybe a premorbid variable in the predisposition to infection in burn victims. PMID:16424207

Lectins Offer New Perspectives in the Development of Macrophage-Targeted Therapies for COPD/Emphysema

PubMed Central

Mukaro, Violet R.; Bylund, Johan; Hodge, Greg; Holmes, Mark; Jersmann, Hubertus; Reynolds, Paul N.; Hodge, Sandra

2013-01-01

We have previously shown that the defective ability of alveolar macrophages (AM) to phagocytose apoptotic cells (‘efferocytosis’) in chronic obstructive pulmonary disease/emphysema (COPD) could be therapeutically improved using the C-type lectin, mannose binding lectin (MBL), although the exact mechanisms underlying this effect are unknown. An S-type lectin, galectin-3, is also known to regulate macrophage phenotype and function, via interaction with its receptor CD98. We hypothesized that defective expression of galectin/CD98 would be associated with defective efferocytosis in COPD and that mechanisms would include effects on cytoskeletal remodeling and macrophage phenotype and glutathione (GSH) availability. Galectin-3 was measured by ELISA in BAL from controls, smokers and current/ex-smokers with COPD. CD98 was measured on AM using flow cytometry. We assessed the effects of galectin-3 on efferocytosis, CD98, GSH, actin polymerisation, rac activation, and the involvement of PI3K (using β-actin probing and wortmannin inhibition) in vitro using human AM and/or MH-S macrophage cell line. Significant decreases in BAL galectin-3 and AM CD98 were observed in BAL from both current- and ex-smoker COPD subjects vs controls. Galectin 3 increased efferocytosis via an increase in active GTP bound Rac1. This was confirmed with β-actin probing and the role of PI3K was confirmed using wortmannin inhibition. The increased efferocytosis was associated with increases in available glutathione and expression of CD98. We provide evidence for a role of airway lectins in the failed efferocytosis in COPD, supporting their further investigation as potential macrophage-targeted therapies. PMID:23441163

Serum levels of mannose-binding lectin and the risk of infection in pediatric oncology patients with chemotherapy.

PubMed

Ghazi, Mona; Isadyar, Mina; Gachkar, Latif; Mahmoudi, Shima; Goudarzi, Hossein; Eslami, Gita; Pourakbari, Babak; Fallah, Fatemeh

2012-03-01

Morbidity and mortality due to infections remain serious problems in pediatric oncology patients receiving chemotherapy. Association of mannose-binding lectin (MBL) levels with an increased risk for infection in previous studies was contradictory. The aim of this study was to determine whether MBL deficiency is associated with the risk of infections in pediatric oncology patients. Before the start of chemotherapy a blood sample was taken from 75 patients with acute lymphoblastic leukemia and MBL serum concentration was measured using a commercially enzyme-linked immunosorbent assay kit. Twenty patients had concentrations under 1000 µg/L, defining MBL deficiency and the remaining 55 patients had concentrations >1000 µg/L. Ten patients suffered from more than 1 episode of severe infection. Sixty-five percent of patients with MBL below 1000 µg/mL suffered from 2 or more episodes of infections (3 of 16 individuals with 1 severe infection; 10 of 16 with 2 and 3 of 16 with 3), in contrast to only 29 of 55 (52%) patients with MBL above 1000 µg/mL (19 of 27 individuals with 1 severe infection and 10 of 27 with 2). The difference between 2 groups was significant (P<0.001). The results of this study indicate that low MBL serum levels (<1000 µg/L) identify pediatric cancer patients at increased risk for infections.

Mannose-binding lectin contributes to deleterious inflammatory response in pandemic H1N1 and avian H9N2 infection.

PubMed

Ling, Man To; Tu, Wenwei; Han, Yan; Mao, Huawei; Chong, Wai Po; Guan, Jing; Liu, Ming; Lam, Kwok Tai; Law, Helen K W; Peiris, J S Malik; Takahashi, K; Lau, Yu Lung

2012-01-01

Mannose-binding lectin (MBL) is a pattern-recognition molecule, which functions as a first line of host defense. Pandemic H1N1 (pdmH1N1) influenza A virus caused massive infection in 2009 and currently circulates worldwide. Avian influenza A H9N2 (H9N2/G1) virus has infected humans and has the potential to be the next pandemic virus. Antiviral function and immunomodulatory role of MBL in pdmH1N1 and H9N2/G1 virus infection have not been investigated. In this study, MBL wild-type (WT) and MBL knockout (KO) murine models were used to examine the role of MBL in pdmH1N1 and H9N2/G1 virus infection. Our study demonstrated that in vitro, MBL binds to pdmH1N1 and H9N2/G1 viruses, likely via the carbohydrate recognition domain of MBL. Wild-type mice developed more severe disease, as evidenced by a greater weight loss than MBL KO mice during influenza virus infection. Furthermore, MBL WT mice had enhanced production of proinflammatory cytokines and chemokines compared with MBL KO mice, suggesting that MBL could upregulate inflammatory responses that may potentially worsen pdmH1N1 and H9N2/G1 virus infections. Our study provided the first in vivo evidence that MBL may be a risk factor during pdmH1N1 and H9N2/G1 infection by upregulating proinflammatory response.

Extensive Basal Level Activation of Complement Mannose-Binding Lectin-Associated Serine Protease-3: Kinetic Modeling of Lectin Pathway Activation Provides Possible Mechanism.

PubMed

Oroszlán, Gábor; Dani, Ráhel; Szilágyi, András; Závodszky, Péter; Thiel, Steffen; Gál, Péter; Dobó, József

2017-01-01

Serine proteases (SPs) are typically synthesized as precursors, termed proenzymes or zymogens, and the fully active form is produced via limited proteolysis by another protease or by autoactivation. The lectin pathway of the complement system is initiated by mannose-binding lectin (MBL)-associated SPs (MASP)-1, and MASP-2, which are known to be present as proenzymes in blood. The third SP of the lectin pathway, MASP-3, was recently shown to be the major activator, and the exclusive "resting blood" activator of profactor D, producing factor D, the initiator protease of the alternative pathway. Because only activated MASP-3 is capable of carrying out this cleavage, it was presumed that a significant fraction of MASP-3 must be present in the active form in resting blood. Here, we aimed to detect active MASP-3 in the blood by a more direct technique and to quantitate the active to zymogen ratio. First, MASPs were partially purified (enriched) from human plasma samples by affinity chromatography using immobilized MBL in the presence of inhibitors. Using this MASP pool, only the zymogen form of MASP-1 was detected by Western blot, whereas over 70% MASP-3 was in an activated form in the same samples. Furthermore, the active to zymogen ratio of MASP-3 showed little individual variation. It is enigmatic how MASP-3, which is not able to autoactivate, is present mostly as an active enzyme, whereas MASP-1, which has a potent autoactivation capability, is predominantly proenzymic in resting blood. In an attempt to explain this phenomenon, we modeled the basal level fluid-phase activation of lectin pathway proteases and their subsequent inactivation by C1 inhibitor and antithrombin using available and newly determined kinetic constants. The model can explain extensive MASP-3 activation only if we assume efficient intracomplex activation of MASP-3 by zymogen MASP-1. On the other hand, the model is in good agreement with the fact that MASP-1 and -2 are predominantly proenzymic and

C-type lectin Mincle is an activating receptor for pathogenic fungus, Malassezia

PubMed Central

Yamasaki, Sho; Matsumoto, Makoto; Takeuchi, Osamu; Matsuzawa, Tetsuhiro; Ishikawa, Eri; Sakuma, Machie; Tateno, Hiroaki; Uno, Jun; Hirabayashi, Jun; Mikami, Yuzuru; Takeda, Kiyoshi; Akira, Shizuo; Saito, Takashi

2009-01-01

Mincle (also called as Clec4e and Clecsf9) is a C-type lectin receptor expressed in activated phagocytes. Recently, we have demonstrated that Mincle is an FcRγ-associated activating receptor that senses damaged cells. To search an exogenous ligand(s), we screened pathogenic fungi using cell line expressing Mincle, FcRγ, and NFAT-GFP reporter. We found that Mincle specifically recognizes the Malassezia species among 50 different fungal species tested. Malassezia is a pathogenic fungus that causes skin diseases, such as tinea versicolor and atopic dermatitis, and fatal sepsis. However, the specific receptor on host cells has not been identified. Mutation of the putative mannose-binding motif within C-type lectin domain of Mincle abrogated Malassezia recognition. Analyses of glycoconjugate microarray revealed that Mincle selectively binds to α-mannose but not mannan. Thus, Mincle may recognize specific geometry of α-mannosyl residues on Malassezia species and use this to distinguish them from other fungi. Malassezia activated macrophages to produce inflammatory cytokines/chemokines. To elucidate the physiological function of Mincle, Mincle-deficient mice were established. Malassezia-induced cytokine/chemokine production by macrophages from Mincle−/− mice was significantly impaired. In vivo inflammatory responses against Malassezia was also impaired in Mincle−/− mice. These results indicate that Mincle is the first specific receptor for Malassezia species to be reported and plays a crucial role in immune responses to this fungus. PMID:19171887

Genetic mannose binding lectin deficiency is associated with airway microbiota diversity and reduced exacerbation frequency in COPD.

PubMed

Dicker, Alison J; Crichton, Megan L; Cassidy, Andrew J; Brady, Gill; Hapca, Adrian; Tavendale, Roger; Einarsson, Gisli G; Furrie, Elizabeth; Elborn, J Stuart; Schembri, Stuart; Marshall, Sara E; Palmer, Colin N A; Chalmers, James D

2018-06-01

In cystic fibrosis and bronchiectasis, genetic mannose binding lectin (MBL) deficiency is associated with increased exacerbations and earlier mortality; associations in COPD are less clear. Preclinical data suggest MBL interferes with phagocytosis of Haemophilus influenzae , a key COPD pathogen. We investigated whether MBL deficiency impacted on clinical outcomes or microbiota composition in COPD. Patients with COPD (n=1796) underwent MBL genotyping; linkage to health records identified exacerbations, lung function decline and mortality. A nested subcohort of 141 patients, followed for up to 6 months, was studied to test if MBL deficiency was associated with altered sputum microbiota, through 16S rRNA PCR and sequencing, or airway inflammation during stable and exacerbated COPD. Patients with MBL deficiency with COPD were significantly less likely to have severe exacerbations (incidence rate ratio (IRR) 0.66, 95% CI 0.48 to 0.90, p=0.009), or to have moderate or severe exacerbations (IRR 0.77, 95% CI 0.60 to 0.99, p=0.047). MBL deficiency did not affect rate of FEV 1 decline or mortality. In the subcohort, patients with MBL deficiency had a more diverse lung microbiota (p=0.008), and were less likely to be colonised with Haemophilus spp. There were lower levels of airway inflammation in patients with MBL deficiency. Patients with MBL deficient genotype with COPD have a lower risk of exacerbations and a more diverse lung microbiota. This is the first study to identify a genetic association with the lung microbiota in COPD. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Low serum mannose-binding lectin levels are associated with inflammation and apoptosis in early surveillance allograft biopsies.

PubMed

Ibernon, M; Moreso, F; O'Valle, F; Grinyo, J M; Moral, R G; Seron, D

2014-09-01

Mannose-binding lectin (MBL) is a protein of the innate immune system that participates in host defense and the tissue injury/repair process, enhancing the clearance of apoptotic cells by macrophages. The aim is to characterize the relationship between pre-transplant MBL levels, histological lesions and number of apoptotic cells in early surveillance renal allograft biopsies. Consecutive renal transplant recipients were recruited and MBL levels were classified into tertiles. The first tertile was considered the low MBL group. Surveillance biopsies were done during the first 6 months and were evaluated according to Banff criteria. Renal inflammatory infiltrates were studied by immunohistochemical techniques. Apoptosis was studied using morphological methods in renal tubular cells and was expressed as the number of apoptotic cells/mm(2). MBL was determined in 126 patients and a surveillance biopsy with sufficient tissue was obtained in 41 of them. Patients with low pre-transplant MBL levels showed a higher acute Banff index (3.14 ± 1.96 vs. 1.88 ± 1.56, p = 0.044) and an increased proportion of biopsies with tubular cell apoptosis The proportion of biopsies with tubular cell apoptosis was higher in patients with low pre-transplant MBL levels in comparison with patients with high MBL levels (4.3 ± 3.6 versus 0.2 ± 0.9 p = 0.012) and increased interstitial number of inflammatory cells and significantly the macrophages/mm(2) (109 ± 118 vs. 32 ± 46; p = 0.04). Low pre-transplant serum MBL levels are associated with more severe inflammation and increased apoptosis in early surveillance renal allograft biopsies suggesting that MBL modulates renal inflammation after transplantation. Copyright © 2014 Elsevier B.V. All rights reserved.

Mannose-Binding Lectin Contributes to Deleterious Inflammatory Response in Pandemic H1N1 and Avian H9N2 Infection

PubMed Central

Ling, Man To; Tu, Wenwei; Han, Yan; Mao, Huawei; Chong, Wai Po; Guan, Jing; Liu, Ming; Lam, Kwok Tai; Law, Helen K. W.; Peiris, J. S. Malik; Takahashi, K.

2012-01-01

Background. Mannose-binding lectin (MBL) is a pattern-recognition molecule, which functions as a first line of host defense. Pandemic H1N1 (pdmH1N1) influenza A virus caused massive infection in 2009 and currently circulates worldwide. Avian influenza A H9N2 (H9N2/G1) virus has infected humans and has the potential to be the next pandemic virus. Antiviral function and immunomodulatory role of MBL in pdmH1N1 and H9N2/G1 virus infection have not been investigated. Methods. In this study, MBL wild-type (WT) and MBL knockout (KO) murine models were used to examine the role of MBL in pdmH1N1 and H9N2/G1 virus infection. Results. Our study demonstrated that in vitro, MBL binds to pdmH1N1 and H9N2/G1 viruses, likely via the carbohydrate recognition domain of MBL. Wild-type mice developed more severe disease, as evidenced by a greater weight loss than MBL KO mice during influenza virus infection. Furthermore, MBL WT mice had enhanced production of proinflammatory cytokines and chemokines compared with MBL KO mice, suggesting that MBL could upregulate inflammatory responses that may potentially worsen pdmH1N1 and H9N2/G1 virus infections. Conclusions. Our study provided the first in vivo evidence that MBL may be a risk factor during pdmH1N1 and H9N2/G1 infection by upregulating proinflammatory response. PMID:22080095

Biological activities of human mannose-binding lectin bound to two different ligand sugar structures, Lewis A and Lewis B antigens and high-mannose type oligosaccharides.

PubMed

Muto, S; Takada, T; Matsumoto, K

2001-07-02

The biological activities of mannose-binding lectin (MBL) which binds to different ligands on mammalian cells were examined using two types of Colo205 cells, a human colon adenocarcinoma cell line: one naturally expressing Lewis A and Lewis B antigens as ligands for MBL (NT-Colo205), and the other modified to express high-mannose type oligosaccharides by treatment with benzyl-2-acetamide-2-deoxy-alpha-galactopyranoside and 1-deoxymannojirimycin (Bz+dMM-Colo205). Although the final lysis was not observed, the deposition of C4 and C3 was observed on both types of Colo205 cells after treatment with MBL and complements as a result of complement activation by MBL. MBL bound to Bz+dMM-Colo205 could also activate human peripheral blood leukocytes and induce superoxide production; however, MBL bound to NT-Colo205 could not. This may be explained by the lower affinity of MBL to Lewis A and Lewis B antigens than to high-mannose type oligosaccharides under physiological conditions, since MBL bound to NT-Colo205 was more easily released from the cell surface than that bound to Bz+dMM-Colo205 at 37 degrees C. These findings suggest that the difference in the affinity of MBL to its ligands could influence the expression of some biological activities of MBL.

Sepsis in acute myeloid leukaemia patients receiving high-dose chemotherapy: no impact of chitotriosidase and mannose-binding lectin polymorphisms.

PubMed

Klostergaard, Anja; Steffensen, Rudi; Møller, Jens K; Peterslund, Niels; Juhl-Christensen, Caroline; Mølle, Ingolf

2010-07-01

Infections after chemotherapy often cause significant morbidity in patients with acute myeloid leukaemia (AML). Chitotriosidase (CHIT) and mannose-binding lectin (MBL) are part of the innate immune system. Polymorphism in the CHIT-coding gene (CHIT1) may be associated with Gram-negative sepsis in children with AML, and polymorphism in the MBL-coding gene (MBL2) seems to modify the risk of infections in several patient groups. The purpose of this study was to investigate the possible associations between polymorphisms in CHIT1, MBL2 and sepsis in adult patients treated with high-dose chemotherapy for AML. We included 190 patients treated with 526 cycles of chemotherapy. The follow-up period was 6 months from the diagnosis of AML. Prophylactic antibiotics were not used. We identified 604 febrile episodes with 246 episodes of sepsis. Thirty-two patients (17%) either died from infection or infection was a major concomitant factor for death. No significant associations between CHIT1 polymorphism and sepsis (P = 0.85) or death caused by sepsis (P = 0.14) were found. Furthermore, no significant associations between MBL2 polymorphism and sepsis (P = 0.76) or death caused by sepsis (P = 0.24) were observed. The severe and long-lasting neutropenia and mucositis after chemotherapy may explain why the MBL system does not protect against sepsis in patients with AML. Replacement therapy with recombinant MBL is not likely to decrease the risk of sepsis in patients with AML.

Mannose-Binding Lectin Codon 54 Gene Polymorphism and Vulvovaginal Candidiasis: A Systematic Review and Meta-Analysis

PubMed Central

Nedovic, Bojan; Posteraro, Brunella; Leoncini, Emanuele; Amore, Rosarita; Sanguinetti, Maurizio; Boccia, Stefania

2014-01-01

Mannose-binding lectin (MBL) plays a key role in the human innate immune response. It has been shown that polymorphisms in the MBL2 gene, particularly at codon 54 (variant allele B; wild-type allele designated as A), impact upon host susceptibility to Candida infection. This systematic review and meta-analysis were performed to assess the association between MBL2 codon 54 genotype and vulvovaginal candidiasis (VVC) or recurrent VVC (RVVC). Studies were searched in MEDLINE, SCOPUS, and ISI Web of Science until April 2013. Five studies including 704 women (386 cases and 318 controls) were part of the meta-analysis, and pooled ORs were calculated using the random effects model. For subjects with RVVC, ORs of AB versus AA and of BB versus AA were 4.84 (95% CI 2.10–11.15; P for heterogeneity = 0.013; I 2 = 68.6%) and 12.68 (95% CI 3.74–42.92; P for heterogeneity = 0.932, I 2 = 0.0%), respectively. For subjects with VVC, OR of AB versus AA was 2.57 (95% CI 1.29–5.12; P for heterogeneity = 0.897; I 2 = 0.0%). This analysis indicates that heterozygosity for the MBL2 allele B increases significantly the risk for both diseases, suggesting that MBL may influence the women's innate immunity in response to Candida. PMID:25143944

Candida glabrata binds to glycosylated and lectinic receptors on the coronary endothelial luminal membrane and inhibits flow sense and cardiac responses to agonists.

PubMed

Torres-Tirado, David; Knabb, Maureen; Castaño, Irene; Patrón-Soberano, Araceli; De Las Peñas, Alejandro; Rubio, Rafael

2016-01-01

Candida glabrata (CG) is an opportunistic fungal pathogen that initiates infection by binding to host cells via specific lectin-like adhesin proteins. We have previously shown the importance of lectin-oligosaccharide binding in cardiac responses to flow and agonists. Because of the lectinic-oligosaccharide nature of CG binding, we tested the ability of CG to alter the agonist- and flow-induced changes in cardiac function in isolated perfused guinea pig hearts. Both transmission and scanning electron microscopy showed strong attachment of CG to the coronary endothelium, even after extensive washing. CG shifted the coronary flow vs. auricular-ventricular (AV) delay relationship upward, indicating that greater flow was required to achieve the same AV delay. This effect was completely reversed with mannose, partially reversed with galactose and N-acetylgalactosamine, but hyaluronan had no effect. Western blot analysis was used to determine binding of CG to isolated coronary endothelial luminal membrane (CELM) receptors, and the results indicate that flow-sensitive CELM receptors, ANG II type I, α-adrenergic 1A receptor, endothelin-2, and VCAM-1 bind to CG. In addition, CG inhibited agonist-induced effects of bradykinin, angiotensin, and phenylephrine on AV delay, coronary perfusion pressure, and left ventricular pressure. Mannose reversed the inhibitory effects of CG on the agonist responses. These results suggest that CG directly binds to flow-sensitive CELM receptors via lectinic-oligosaccharide interactions with mannose and disrupts the lectin-oligosaccharide binding necessary for flow-induced cardiac responses. Copyright © 2016 the American Physiological Society.

Molecular Characterization and Biological Effects of a C-Type Lectin-Like Receptor in Large Yellow Croaker (Larimichthys crocea).

PubMed

Ao, Jingqun; Ding, Yang; Chen, Yuanyuan; Mu, Yinnan; Chen, Xinhua

2015-12-10

The C-type lectin-like receptors (CTLRs) play important roles in innate immunity as one type of pattern recognition receptors. Here, we cloned and characterized a C-type lectin-like receptor (LycCTLR) from large yellow croaker Larimichthys crocea. The full-length cDNA of LycCTLR is 880 nucleotides long, encoding a protein of 215 amino acids. The deduced LycCTLR contains a C-terminal C-type lectin-like domain (CTLD), an N-terminal cytoplasmic tail, and a transmembrane region. The CTLD of LycCTLR possesses six highly conserved cysteine residues (C1-C6), a conserved WI/MGL motif, and two sugar binding motifs, EPD (Glu-Pro-Asp) and WYD (Trp-Tyr-Asp). Ca(2+) binding site 1 and 2 were also found in the CTLD. The LycCTLR gene consists of five exons and four introns, showing the same genomic organization as tilapia (Oreochromis niloticus) and guppy (Poecilia retitculata) CTLRs. LycCTLR was constitutively expressed in various tissues tested, and its transcripts significantly increased in the head kidney and spleen after stimulation with inactivated trivalent bacterial vaccine. Recombinant LycCTLR (rLycCTLR) protein produced in Escherichia coli BL21 exhibited not only the hemagglutinating activity and a preference for galactose, but also the agglutinating activity against two food-borne pathogenic bacteria E. coli and Bacillus cereus in a Ca(2+)-dependent manner. These results indicate that LycCTLR is a potential galactose-binding C-type lectin that may play a role in the antibacterial immunity in fish.

Lectins discriminate between pathogenic and nonpathogenic South American trypanosomes

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

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 europaeusmore » 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.« less

Isolation and characterization of a novel lectin from the mushroom Armillaria luteo-virens

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

Feng, K.; College of Food Science, Heilongjiang August First Land Reclamation University, Daqing 163319; Liu, Q.H.

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},more » 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.« less

Quantitative Expression of C-Type Lectin Receptors in Humans and Mice

PubMed Central

Lech, Maciej; Susanti, Heni Eka; Römmele, Christoph; Gröbmayr, Regina; Günthner, Roman; Anders, Hans-Joachim

2012-01-01

C-type lectin receptors and their adaptor molecules are involved in the recognition of glycosylated self-antigens and pathogens. However, little is known about the species- and organ-specific expression profiles of these molecules. We therefore determined the mRNA expression levels of Dectin-1, MR1, MR2, DC-SIGN, Syk, Card-9, Bcl-10, Malt-1, Src, Dec-205, Galectin-1, Tim-3, Trem-1, and DAP-12 in 11 solid organs of human and mice. Mouse organs revealed lower mRNA levels of most molecules compared to spleen. However, Dec-205 and Galectin-1 in thymus, Src in brain, MR2, Card-9, Bcl-10, Src, and Dec-205 in small intestine, MR2, Bcl-10, Src, Galectin-1 in kidney, and Src and Galectin-1 in muscle were at least 2-fold higher expressed compared to spleen. Human lung, liver and heart expressed higher mRNA levels of most genes compared to spleen. Dectin-1, MR1, Syk and Trem-1 mRNA were strongly up-regulated upon ischemia-reperfusion injury in murine kidney. Tim3, DAP-12, Card-9, DC-SIGN and MR2 were further up-regulated during renal fibrosis. Murine kidney showed higher DAP-12, Syk, Card-9 and Dectin-1 mRNA expression during the progression of lupus nephritis. Thus, the organ-, and species-specific expression of C-type lectin receptors is different between mice and humans which must be considered in the interpretation of related studies. PMID:22949850

Ulex europaeus agglutinin II (UEA-II) is a novel, potent inhibitor of complement activation.

PubMed

Lekowski, R; Collard, C D; Reenstra, W R; Stahl, G L

2001-02-01

Complement is an important mediator of vascular injury following oxidative stress. We recently demonstrated that complement activation following endothelial oxidative stress is mediated by mannose-binding lectin (MBL) and activation of the lectin complement pathway. Here, we investigated whether nine plant lectins which have a binding profile similar to that of MBL competitively inhibit MBL deposition and subsequent complement activation following human umbilical vein endothelial cell (HUVEC) oxidative stress. HUVEC oxidative stress (1% O(2), 24 hr) significantly increased Ulex europaeus agglutinin II (UEA-II) binding by 72 +/- 9% compared to normoxic cells. UEA-II inhibited MBL binding to HUVEC in a concentration-dependent manner following oxidative stress. Further, MBL inhibited UEA-II binding to HUVEC in a concentration-dependent manner following oxidative stress, suggesting a common ligand. UEA-II (< or = 100 micromol/L) did not attenuate the hemolytic activity, nor did it inhibit C3a des Arg formation from alternative or classical complement pathway-specific hemolytic assays. C3 deposition (measured by ELISA) following HUVEC oxidative stress was inhibited by UEA-II in a concentration-dependent manner (IC(50) = 10 pmol/L). UEA-II inhibited C3 and MBL co-localization (confocal microscopy) in a concentration-dependent manner on HUVEC following oxidative stress (IC(50) approximately 1 pmol/L). Finally, UEA-II significantly inhibited complement-dependent neutrophil chemotaxis, but failed to inhibit fMLP-mediated chemotaxis, following endothelial oxidative stress. These data demonstrate that UEA-II is a novel, potent inhibitor of human MBL deposition and complement activation following human endothelial oxidative stress.

Ulex europaeus agglutinin II (UEA-II) is a novel, potent inhibitor of complement activation

PubMed Central

Lekowski, Robert; Collard, Charles D.; Reenstra, Wende R.; Stahl, Gregory L.

2001-01-01

Complement is an important mediator of vascular injury following oxidative stress. We recently demonstrated that complement activation following endothelial oxidative stress is mediated by mannose-binding lectin (MBL) and activation of the lectin complement pathway. Here, we investigated whether nine plant lectins which have a binding profile similar to that of MBL competitively inhibit MBL deposition and subsequent complement activation following human umbilical vein endothelial cell (HUVEC) oxidative stress. HUVEC oxidative stress (1% O2, 24 hr) significantly increased Ulex europaeus agglutinin II (UEA-II) binding by 72 ± 9% compared to normoxic cells. UEA-II inhibited MBL binding to HUVEC in a concentration-dependent manner following oxidative stress. Further, MBL inhibited UEA-II binding to HUVEC in a concentration-dependent manner following oxidative stress, suggesting a common ligand. UEA-II (≤ 100 μmol/L) did not attenuate the hemolytic activity, nor did it inhibit C3a des Arg formation from alternative or classical complement pathway-specific hemolytic assays. C3 deposition (measured by ELISA) following HUVEC oxidative stress was inhibited by UEA-II in a concentration-dependent manner (IC50 = 10 pmol/L). UEA-II inhibited C3 and MBL co-localization (confocal microscopy) in a concentration-dependent manner on HUVEC following oxidative stress (IC50 ≈ 1 pmol/L). Finally, UEA-II significantly inhibited complement-dependent neutrophil chemotaxis, but failed to inhibit fMLP-mediated chemotaxis, following endothelial oxidative stress. These data demonstrate that UEA-II is a novel, potent inhibitor of human MBL deposition and complement activation following human endothelial oxidative stress. PMID:11266613

How does mother-to-child transmission of HIV differ among African populations? Lessons from MBL2 genetic variation in Zimbabweans.

PubMed

Mhandire, Kudakwashe; Pharo, Gavin; Kandawasvika, Gwendolene Q; Duri, Kerina; Swart, Marelize; Stray-Pedersen, Babill; Dandara, Collet

2014-07-01

Mannose binding lectin (MBL) is a pathogen pattern recognition protein involved in antimicrobial activities. Variation in MBL2 gene has been extensively implicated in differential outcomes of infectious diseases in studies conducted outside Africa, but virtually very little is known on the role of this candidate gene in the African continent. We investigated human genetic variations in MBL2 in a Zimbabwean pediatric population and their putative associations with HIV infection in perinatally exposed children. One hundred and four children aged 7 to 9 years comprising 68 perinatally exposed to HIV (32 who were born infected and 36 who were uninfected) and 36 unexposed controls were recruited. DNA samples were genotyped for MBL2 polymorphisms using PCR-RFLP and sequencing. HIV infected children had markedly variable and significantly lower mean height (p=0.03) and weight (p=0.005) when compared to the uninfected children. Using all samples, frequencies for MBL2 genetic variants for the Zimbabwean population were calculated. Twelve single nucleotide polymorphisms were observed and minor alleles occurred with the following frequencies: -550C>G (G: 0.02), -435G>A (A: 0.08), -428A>C (C: 0.39), -394A>G (A: 0.39), -328AGAGAA ins/del (AGAGAA ins: 0.44), -245G>A (A: 0.05), -221C>G (C: 0.12), -111A>T (T: 0.10), -70C>T (C: 0.46), +4C>T (C: 0.45), novel -595G>A (A: 0.02), and 170G>A (0.24). We found that the MBL2 +4T variant displayed a trend for association with reduced risk of HIV transmission from mother-to-child but the remaining vast majority of the genetic markers did not show a significant association. We conclude (1) the MBL2 gene is highly polymorphic in the Zimbabwean population, and (2) MBL2 genetic variation does not appear to play a major role in influencing the risk of mother-to-child HIV transmission in our study sample. These observations contest the hitherto significant role of this candidate gene for HIV transmission from mother-to-child in non

The Interaction of Human Pathogenic Fungi With C-Type Lectin Receptors.

PubMed

Goyal, Surabhi; Castrillón-Betancur, Juan Camilo; Klaile, Esther; Slevogt, Hortense

2018-01-01

Fungi, usually present as commensals, are a major cause of opportunistic infections in immunocompromised patients. Such infections, if not diagnosed or treated properly, can prove fatal. However, in most cases healthy individuals are able to avert the fungal attacks by mounting proper antifungal immune responses. Among the pattern recognition receptors (PRRs), C-type lectin receptors (CLRs) are the major players in antifungal immunity. CLRs can recognize carbohydrate ligands, such as β-glucans and mannans, which are mainly found on fungal cell surfaces. They induce proinflammatory immune reactions, including phagocytosis, oxidative burst, cytokine, and chemokine production from innate effector cells, as well as activation of adaptive immunity via Th17 responses. CLRs such as Dectin-1, Dectin-2, Mincle, mannose receptor (MR), and DC-SIGN can recognize many disease-causing fungi and also collaborate with each other as well as other PRRs in mounting a fungi-specific immune response. Mutations in these receptors affect the host response and have been linked to a higher risk in contracting fungal infections. This review focuses on how CLRs on various immune cells orchestrate the antifungal response and on the contribution of single nucleotide polymorphisms in these receptors toward the risk of developing such infections.

Interactions of lectins with plasma membrane glycoproteins of the Ehrlich ascites carcinoma cell.

PubMed

Nachbar, M S; Oppenheim, J D; Aull, F

1976-02-06

Several aspects of the interaction of various lectins with the surface of Ehrlich ascites carcinoma cells are described. The order of agglutinating activity for various lectins is Ricinus communis greater than wheat germ greater than or equal to concanavalin A greater than or equal to soybean greater than Limulus polyphemus. No agglutination was noted for Ulex europaeus. Using 125I-labeled lectins it was determined that there are 1.6 and 7 times as many Ricinus communis lectin binding sites for concanavalin A and soybean lectins. Sodium deoxycholate-solubilized plasma membrane material was subjected to lectin affinity chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The lectin receptors of the plasma membrane appeared to be heterogeneous and some qualitative differences could be discerned among the electrophoretically analyzed material, which bound to and was specifically eluted from the various lectin affinity columns. The characteristics of elution of bound material from individual lectin columns indicated secondary hydrophobic interactions between concanavalin A or wheat germ agglutinin and their respective lectin receptor molecules.

Modeling and MBL: Software Tools for Science.

ERIC Educational Resources Information Center

Tinker, Robert F.

Recent technological advances and new software packages put unprecedented power for experimenting and theory-building in the hands of students at all levels. Microcomputer-based laboratory (MBL) and model-solving tools illustrate the educational potential of the technology. These tools include modeling software and three MBL packages (which are…

HIV-1 Vertical Transmission in Zimbabwe in 622 Mother and Infant Pairs: Rethinking the Contribution of Mannose Binding Lectin Deficiency in Africa.

PubMed

Zinyama-Gutsire, Rutendo B L; Christiansen, Michael; Hedley, Paula L; Rusakaniko, Simbarashe; Hagen, Christian; Stray-Pedersen, Babill; Buzdugan, Raluca; Cowan, Frances; Chasela, Charles

2016-07-01

Vertical transmission of human immunodeficiency virus (HIV) remains a major global health problem. We assessed the association of mannose binding lectin (MBL) deficiency and vertical transmission of HIV. Novel diagnostics would be a major breakthrough in this regard. MBL is a liver-derived protein and a key component of the innate immune system. MBL levels may be classified as normal, intermediate, or deficient in the plasma and can use MBL2 haplotypes as a proxy. These haplotypes comprise polymorphisms in the MBL2 gene and promoter region and are known to result in varying levels of MBL deficiency. MBL deficiency can be defined as presence of A/O and O/O genotypes in the mothers and their children. MBL deficiency leads to defective opsonization activities of the innate immune system and increased susceptibility to several infections, including HIV-1. We determined the prevalence of MBL deficiency, using MBL2 haplotypes among 622 HIV-positive Zimbabwean mothers and their children aged 9-18 months old, in relation to the HIV-1 vertical transmission risk. The median age of the mothers was 30 (26-34, interquartile range [IQR]) years, and the babies' median age was 13 (11-15, IQR) months old at the time of enrollment. From the sample of 622 mothers who were HIV-1 infected, 574 babies were HIV negative and 48 were HIV-1-positive babies, giving a transmission rate of 7.7%. MBL2 normal structural allele A and variants B (codon 5 A>G), C (codon 57 A>G), and promoter region SNPs -550(H/L) and -221(X/Y) were detected. Prevalence of haplotype-predicted MBL deficiency was 34% among the mothers and 32% among the children. We found no association between maternal MBL2 deficiency and HIV-1 transmission to their children. We found no difference in the distribution of HIV-1 infected and uninfected children between the MBL2 genotypes of the mothers and those of the children. Taken together, the present study in a large sample of mother-infant pairs in Zimbabwe adds to the

Lectin-like oxidized low-density lipoprotein receptor (LOX-1) in sickle cell disease vasculopathy

PubMed Central

Chen, Mingyi; Qiu, Hong; Lin, Xin; Nam, David; Ogbu-Nwobodo, Lucy; Archibald, Hannah; Joslin, Amelia; Wun, Ted; Sawamura, Tatsuya; Green, Ralph

2017-01-01

Lectin-like oxidized low-density lipoprotein (LDL) receptor-1 (LOX-1) is an endothelial receptor for oxidized LDL. Increased expression of LOX-1 has been demonstrated in atherosclerotic lesions and diabetic vasculopathy. In this study, we investigate the expression of LOX-1 receptor in sickle cell disease (SCD) vasculopathy. Expression of LOX-1 in brain vascular endothelium is markedly increased and LOX-1 gene expression is upregulated in cultured human brain microvascular endothelial cells by incubation with SCD erythrocytes. Also, the level of circulating soluble LOX-1 concentration is elevated in the plasma of SCD patients. Increased LOX-1 expression in endothelial cells is potentially involved in the pathogenesis of SCD vasculopathy. Soluble LOX-1 concentration in SCD may provide a novel biomarker for risk stratification of sickle cell vascular complications. PMID:27519944

The role of lectins and glycans in platelet clearance

PubMed Central

Hoffmeister, Karin M.

2015-01-01

Summary In recent years, it has become increasingly apparent that the life span of transfused platelets in circulation is regulated, at least in part, by glycan-lectin mediated mechanisms. There is clear evidence that refrigerated platelets are cleared by glycan-lectin mediated clearance mechanisms. Acute platelet cooling clusters glycoprotein (GP) Ibα receptors bearing uncovered N-acetylglucosamine (GlcNAc), and αMβ2 integrins on hepatic macrophages recognise clustered GlcNAc to rapidly clear these platelets from circulation. With prolonged refrigeration GPIbα clustering bearing uncovered galactose increases, which mediates the removal of long-term refrigerated platelets via hepatic Ashwell-Morell receptors (AMR), originally named as asialoglycoprotein receptors. In contrast, little is known about the molecular mechanisms of transfused room temperature platelet clearance. This review examines the role of glycan-lectin mediated clearance of exogenous, i.e. transfused chilled platelet clearance and briefly addresses the current knowledge of stored platelet function, degradation and its relation to platelet clearance. PMID:21781240

Early Changes of Mannose-Binding Lectin, H-Ficolin, and Procalcitonin in Patients with Febrile Neutropenia: A Prospective Observational Study.

PubMed

Işlak Mutcalı, Sibel; Saltoğlu, Neşe; Balkan, İlker İnanç; Özaras, Reşat; Yemişen, Mücahit; Tabak, Fehmi; Mert, Ali; Öztürk, Recep; Öngören, Şeniz; Başlar, Zafer; Aydın, Yıldız; Ferhanoğlu, Burhan; Soysal, Teoman

2016-12-01

The significance of mannose-binding lectin (MBL) and H-ficolin deficiency in febrile neutropenic (FN) patients and the correlation of these markers along with consecutive C-reactive protein (CRP) and procalcitonin (PCT) levels during the infectious process are investigated. Patients with any hematological malignancies who were defined to have "microbiologically confirmed infection", "clinically documented infection", or "fever of unknown origin" were included in this single-center prospective observational study. Serum levels of CRP, PCT, MBL, and H-ficolin were determined on 3 separate occasions: at baseline (between hospital admission and chemotherapy), at the onset of fever, and at the 72nd hour of fever. Forty-six patients (54% male, mean age 41.7 years) with 61 separate episodes of FN were evaluated. Eleven patients (23.9%) had "microbiologically confirmed infection", 17 (37%) had "clinically documented infection", and 18 (39.1%) had "fever of unknown origin". Fourteen (30.4%) patients had low (<500 ng/mL) initial MBL levels and 7 (15.21%) had low (<12,000 ng/mL) H-ficolin levels. Baseline MBL and H-ficolin levels did not significantly change on the first and third days of fever (p=0.076). Gram-negative bacteremia more frequently occurred in those with low initial MBL levels (p=0.006). PCT levels were significantly higher in those with microbiologically documented infections. Mean and median PCT levels were significantly higher in cases with bacteremia. There was no significant difference between hemoculture-positive and-negative patients in terms of CRP levels. Monitoring serum H-ficolin levels was shown to be of no benefit in terms of predicting severe infection. Low baseline MBL levels were correlated with high risk of gram-negative bacteremia; however, no significant correlation was shown in the follow-up. Close monitoring of PCT levels is warranted to provide more accurate and specific data while monitoring cases of bacteremia.

Αlpha-2 Adrenergic and Opioids Receptors Participation in Mice Gastroprotection of Abelmoschus esculentus Lectin.

PubMed

Ribeiro, Kátia A; Chaves, Hellíada V; Filho, Samuel Mateus Pereira; Pinto, Isabela Ribeiro; Monteiro, Dina Andressa Martins; Matos, Samuel Oliveira; Santi-Gadelha, Tatiane; Gadelha, Carlos Alberto de Almeida; Lacerda, José Thalles Jocelino Gomes de; Aguiar, Lissiana M V; Pereira, Karuza M A; Benevides, Norma M B; Pinto, Vicente de Paulo T; Filho, Gerardo Cristino; Bezerra, Mirna M; Silva, Antonio A R

2016-01-01

Lectins are a heterogeneous group of proteins and glycoproteins with potential role as therapeutic and diagnostic tools to combat various diseases, besides some functions on human organism. Abelmoschus esculentus (Okra), a horticultural plant of African origin, is cultivated in northeastern Brazil, and used for different medicinal purposes. This work is aimed to elucidate the action mechanisms of Abelmoschus esculentus lectin (AEL) gastro protective effect on gastropathy induced by ethanol. Fasted mice treated with Ethanol 99.9% (0.2 ml/animal, p.o.) received previously AEL (0.01, 0.1, 1.0, 10 or 50 mg/kg, i.v.), saline (5 ml/kg; i.v.) or ranitidine (80 mg/kg, p.o.) in four experimental series, in which pharmacological tools (yohimbine, naloxone, L-NAME or indomethacin), were administered with the purpose of make clear possible molecular action mechanisms. Mice were euthanized 30 min after ethanol challenge to verify the stomach damages. Establishment of gastric oxidative stress, tissue hemoglobin (Hb) content and microscopic features (H&E) were taken in order to characterize the AEL gastro protective effect. AEL (1 mg/kg) was capable of protect mucosa against ethanol damages in presence of two (L-NAME and indomethacin) of four antagonists/inhibitors used. The AEL effect was reversed by naloxone and yohimbine, showing the involvement of opioids and Αlpha-2 adrenergic receptors on gastric protective effect of this lectin. Evaluation of microscopic features, oxidative stress, and Hb levels pointed the protective effects of AEL. This activity seems to be mediated by alpha-2 adrenergic and opioid receptors activation. Nitric oxide or prostaglandins were not involved. AEL simultaneously showed antioxidant effect that is probably implicated in its intricate defensive mechanism of action.

Effects of mannose-binding lectin on pulmonary gene expression and innate immune inflammatory response to ozone

PubMed Central

Ciencewicki, Jonathan M.; Verhein, Kirsten C.; Gerrish, Kevin; McCaw, Zachary R.; Li, Jianying; Bushel, Pierre R.

2016-01-01

Ozone is a common, potent oxidant pollutant in industrialized nations. Ozone exposure causes airway hyperreactivity, lung hyperpermeability, inflammation, and cell damage in humans and laboratory animals, and exposure to ozone has been associated with exacerbation of asthma, altered lung function, and mortality. The mechanisms of ozone-induced lung injury and differential susceptibility are not fully understood. Ozone-induced lung inflammation is mediated, in part, by the innate immune system. We hypothesized that mannose-binding lectin (MBL), an innate immunity serum protein, contributes to the proinflammatory events caused by ozone-mediated activation of the innate immune system. Wild-type (Mbl+/+) and MBL-deficient (Mbl−/−) mice were exposed to ozone (0.3 ppm) for up to 72 h, and bronchoalveolar lavage fluid was examined for inflammatory markers. Mean numbers of eosinophils and neutrophils and levels of the neutrophil attractants C-X-C motif chemokines 2 [Cxcl2 (major intrinsic protein 2)] and 5 [Cxcl5 (limb expression, LIX)] in the bronchoalveolar lavage fluid were significantly lower in Mbl−/− than Mbl+/+ mice exposed to ozone. Using genome-wide mRNA microarray analyses, we identified significant differences in transcript response profiles and networks at baseline [e.g., nuclear factor erythroid-related factor 2 (NRF2)-mediated oxidative stress response] and after exposure (e.g., humoral immune response) between Mbl+/+ and Mbl−/− mice. The microarray data were further analyzed to discover several informative differential response patterns and subsequent gene sets, including the antimicrobial response and the inflammatory response. We also used the lists of gene transcripts to search the LINCS L1000CDS2 data sets to identify agents that are predicted to perturb ozone-induced changes in gene transcripts and inflammation. These novel findings demonstrate that targeted deletion of Mbl caused differential levels of inflammation-related gene sets at

The identification of plant lectins with mucosal adjuvant activity.

PubMed

Lavelle, E C; Grant, G; Pusztai, A; Pfüller, U; O'Hagan, D T

2001-01-01

To date, the most potent mucosal vaccine adjuvants to be identified have been bacterial toxins. The present data demonstrate that the type 2 ribosome-inactivating protein (type 2 RIP), mistletoe lectin I (ML-I) is a strong mucosal adjuvant of plant origin. A number of plant lectins were investigated as intranasal (i.n.) coadjuvants for a bystander protein, ovalbumin (OVA). As a positive control, a potent mucosal adjuvant, cholera toxin (CT), was used. Co-administration of ML-I or CT with OVA stimulated high titres of OVA-specific serum immunoglobulin G (IgG) in addition to OVA-specific IgA in mucosal secretions. CT and ML-I were also strongly immunogenic, inducing high titres of specific serum IgG and specific IgA at mucosal sites. None of the other plant lectins investigated significantly boosted the response to co-administered OVA. Immunization with phytohaemagglutinin (PHA) plus OVA elicited a lectin-specific response but did not stimulate an enhanced response to OVA compared with the antigen alone. Intranasal delivery of tomato lectin (LEA) elicited a strong lectin-specific systemic and mucosal antibody response but only weakly potentiated the response to co-delivered OVA. In contrast, administration of wheatgerm agglutinin (WGA) or Ulex europaeus lectin 1 (UEA-I) with OVA stimulated a serum IgG response to OVA while the lectin-specific responses (particularly for WGA) were relatively low. Thus, there was not a direct correlation between immunogenicity and adjuvanticity although the strongest adjuvants (CT, ML-I) were also highly immunogenic.

The identification of plant lectins with mucosal adjuvant activity

PubMed Central

Lavelle, E C; Grant, G; Pusztai, A; Pfüller, U; O'hagan, D T

2001-01-01

To date, the most potent mucosal vaccine adjuvants to be identified have been bacterial toxins. The present data demonstrate that the type 2 ribosome-inactivating protein (type 2 RIP), mistletoe lectin I (ML-I) is a strong mucosal adjuvant of plant origin. A number of plant lectins were investigated as intranasal (i.n.) coadjuvants for a bystander protein, ovalbumin (OVA). As a positive control, a potent mucosal adjuvant, cholera toxin (CT), was used. Co-administration of ML-I or CT with OVA stimulated high titres of OVA-specific serum immunoglobulin G (IgG) in addition to OVA-specific IgA in mucosal secretions. CT and ML-I were also strongly immunogenic, inducing high titres of specific serum IgG and specific IgA at mucosal sites. None of the other plant lectins investigated significantly boosted the response to co-administered OVA. Immunization with phytohaemagglutinin (PHA) plus OVA elicited a lectin-specific response but did not stimulate an enhanced response to OVA compared with the antigen alone. Intranasal delivery of tomato lectin (LEA) elicited a strong lectin-specific systemic and mucosal antibody response but only weakly potentiated the response to co-delivered OVA. In contrast, administration of wheatgerm agglutinin (WGA) or Ulex europaeus lectin 1 (UEA-I) with OVA stimulated a serum IgG response to OVA while the lectin-specific responses (particularly for WGA) were relatively low. Thus, there was not a direct correlation between immunogenicity and adjuvanticity although the strongest adjuvants (CT, ML-I) were also highly immunogenic. PMID:11168640

Identification of a Gal/GalNAc Lectin in the Protozoan Hartmannella vermiformis as a Potential Receptor for Attachment and Invasion by the Legionnaires' Disease Bacterium

PubMed Central

Venkataraman, Chandrasekar; Haack, Bradley J.; Bondada, Subbarao; Kwaik, Yousef Abu

1997-01-01

The Legionnaire's disease bacterium, Legionella pneumophila, is a facultative intracellular pathogen which invades and replicates within two evolutionarily distant hosts, free-living protozoa and mammalian cells. Invasion and intracellular replication within protozoa are thought to be major factors in the transmission of Legionnaire's disease. Although attachment and invasion of human macrophages by L. pneumophila is mediated in part by the complement receptors CR1 and CR3, the protozoan receptor involved in bacterial attachment and invasion has not been identified. To define the molecular events involved in invasion of protozoa by L. pneumophila, we examined the role of protein tyrosine phosphorylation of the protozoan host Hartmannella vermiformis upon attachment and invasion by L. pneumophila. Bacterial attachment and invasion were associated with a time-dependent tyrosine dephosphorylation of multiple host cell proteins. This host cell response was highly specific for live L. pneumophila, required contact with viable bacteria, and was completely reversible following washing off the bacteria from the host cell surface. Tyrosine dephosphorylation of host proteins was blocked by a tyrosine phosphatase inhibitor but not by tyrosine kinase inhibitors. One of the tyrosine dephosphorylated proteins was identified as the 170-kD galactose/N-acetylgalactosamine–inhibitable lectin (Gal/GalNAc) using immunoprecipitation and immunoblotting by antibodies generated against the Gal/GalNAc lectin of the protozoan Entamoeba histolytica. This Gal/GalNAc–inhibitable lectin has been shown previously to mediate adherence of E. histolytica to mammalian epithelial cells. Uptake of L. pneumophila by H. vermiformis was specifically inhibited by two monovalent sugars, Gal and GalNAc, and by mABs generated against the 170-kD lectin of E. histolytica. Interestingly, inhibition of invasion by Gal and GalNAc was associated with inhibition of bacterial-induced tyrosine dephosphorylation

Targeting C-type lectin receptors: a high-carbohydrate diet for dendritic cells to improve cancer vaccines

PubMed Central

van Dinther, Dieke; Stolk, Dorian A.; van de Ven, Rieneke; van Kooyk, Yvette; de Gruijl, Tanja D.; den Haan, Joke M. M.

2017-01-01

There is a growing understanding of why certain patients do or do not respond to checkpoint inhibition therapy. This opens new opportunities to reconsider and redevelop vaccine strategies to prime an anticancer immune response. Combination of such vaccines with checkpoint inhibitors will both provide the fuel and release the brake for an efficient anticancer response. Here, we discuss vaccine strategies that use C-type lectin receptor (CLR) targeting of APCs, such as dendritic cells and macrophages. APCs are a necessity for the priming of antigen-specific cytotoxic and helper T cells. Because CLRs are natural carbohydrate-recognition receptors highly expressed by multiple subsets of APCs and involved in uptake and processing of Ags for presentation, these receptors seem particularly interesting for targeting purposes. PMID:28729358

Serum amyloid A stimulates macrophage foam cell formation via lectin-like oxidized low-density lipoprotein receptor 1 upregulation

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

Lee, Ha Young, E-mail: hayoung@skku.edu; Mitochondria Hub Regulation Center, Dong-A University, Busan 602-714; Kim, Sang Doo

2013-03-29

Highlights: ► SAA induced macrophage foam cell formation. ► SAA stimulated upregulation of lectin-like oxidized low-density lipoprotein receptor 1 (LOX1). ► SAA-induced LOX1 expression and foam cell formation is mediated by JNK/NF-κB signaling. ► HDL-conjugated SAA also stimulates foam cell formation via LOX1 upregulation. ► The finding reveals a novel mechanism of action of SAA in the pathogenesis of atherosclerosis. -- Abstract: Elevated levels of serum amyloid A (SAA) is a risk factor for cardiovascular diseases, however, the role of SAA in the pathophysiology of atherosclerosis remains unclear. Here we show that SAA induced macrophage foam cell formation. SAA-stimulated foammore » cell formation was mediated by c-jun N-terminal kinase (JNK) signaling. Moreover, both SAA and SAA-conjugated high density lipoprotein stimulated the expression of the important scavenger receptor lectin-like oxidized low-density lipoprotein receptor 1 (LOX1) via nuclear factor-κB (NF-κB). A LOX1 antagonist carrageenan significantly blocked SAA-induced foam cell formation, indicating that SAA promotes foam cell formation via LOX1 expression. Our findings therefore suggest that SAA stimulates foam cell formation via LOX1 induction, and thus likely contributes to atherogenesis.« less

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

Mannose-binding lectin codon 54 gene polymorphism in relation to risk of nosocomial invasive fungal infection in preterm neonates in the neonatal intensive care unit.

PubMed

Aydemir, Cumhur; Onay, Huseyin; Oguz, Serife Suna; Ozdemir, Taha Resid; Erdeve, Omer; Ozkinay, Ferda; Dilmen, Ugur

2011-09-01

Preterm neonates are susceptible to infection due to a combination of sub-optimal immunity and increased exposure to invasive organisms. Invasive fungal infections are associated with significant morbidity and mortality among preterm infants cared for in the neonatal intensive care unit (NICU). Mannose-binding lectin (MBL) is a component of the innate immune system, which may be especially important in the neonatal setting. The objective of this study was to investigate the presence of any association between MBL gene polymorphism and nosocomial invasive fungal infection in preterm neonates. Codon 54 (B allele) polymorphism in exon 1 of the MBL gene was investigated in 31 patients diagnosed as nosocomial invasive fungal infection and 30 control preterm neonates. AB genotype was determined in 26% and 30% of patient and control groups, respectively, and the difference was not statistically significant. AA genotype was determined in 74% of the patient group and in 67% of the control group, and the difference was not statistically significant. B allele frequency was not different significantly in the patient group (13%) compared to the control group (18%). In our study, no relationship was found between MBL codon 54 gene polymorphism and the risk of nosocomial invasive fungal infection in preterm neonates in NICU.

Variants in mannose‐binding lectin and tumour necrosis factor α affect survival in cystic fibrosis

PubMed Central

Buranawuti, Kitti; Boyle, Michael P; Cheng, Suzanne; Steiner, Lori L; McDougal, Kathryn; Fallin, M Daniele; Merlo, Christian; Zeitlin, Pamela L; Rosenstein, Beryl J; Mogayzel, Peter J; Wang, Xinjing; Cutting, Garry R

2007-01-01

Background Patients with cystic fibrosis with the same mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene differ widely in survival suggesting other factors have a substantial role in mortality. Objective To determine if the genotype distribution of variants in three putative cystic fibrosis modifier genes (tumour necrosis factor α (TNFα), transforming growth factor β1 (TGFβ1) or mannose‐binding lectin (MBL2)) differed among patients with cystic fibrosis grouped according to age and survival status. Methods Genotypes of four variants (TNFα‐238, TNFα‐308, TGFβ1‐509 and MBL2 O) were determined in three groups of Caucasians from a single medical centre: 101 children with cystic fibrosis (aged <17 years; mean age 9.4 years), 115 adults with cystic fibrosis (aged ⩾17 years; mean age 30.8 years) and 38 non‐surviving adults with cystic fibrosis (21 deceased and 17 lung transplant after 17 years of age). Genotypes of 127 healthy Caucasians in the same geographical region were used as controls. Kaplan–Meier and Cox hazard regression were used to evaluate the genotype effect on cumulative survival. Results Genotype frequencies among adults and children with cystic fibrosis differed for TNFα‐238 (G/G vs G/A; p = 0.022) and MBL2 (A/A vs O/O; p = 0.016). When adults with cystic fibrosis were compared to non‐surviving adults with cystic fibrosis, genotype frequencies of both genes differed (TNFα‐238G/G vs G/A; p =  0.0015 and MBL2: A/A vs O/O; p = 0.009). The hazard ratio for TNFα‐238G/G vs G/A was 0.25 (95% CI 0.06 to 1.0, p = 0.04) and for MBL2 O/O vs A/A or A/O was 2.5 (95% CI 1.3 to 4.9, p = 0.007). Conclusions TNFα‐238 G/A and MBL2 O/O genotypes appear to be genetic modifiers of survival of cystic fibrosis. PMID:17158822

Molecular cloning of rat sperm galactosyl receptor, a C-type lectin with in vitro egg binding activity.

PubMed

Rivkin, E; Tres, L L; Kaplan-Kraicer, R; Shalgi, R; Kierszenbaum, A L

2000-07-01

Rat sperm galactosyl receptor is a member of the C-type animal lectin family showing preferential binding to N-acetylgalactosamine compared to galactose. Binding is mediated by a Ca(2+)-dependent carbohydrate-recognition domain (CRD) identical to that of the minor variant of rat hepatic lectin receptor 2/3 (RHL-2/3). The molecular organization of the genomic DNA, cDNA, and derived amino acid sequence of rat testis galactosyl receptor have been determined and in vitro fertilization studies were conducted to ascertain its role. We have determined that the rat testis galactosyl receptor gene generates two mRNA species: one species, designated liver-type, is identical to RHL-2/3; the other, designated testis-type, contains one unspliced intron (86 nt) which alters the reading frame and changes the amino acid sequence of the carboxyl terminus. As a result, the CRD (glutamine-proline-aspartic acid/QPD) and flanked Ca(2+)-binding amino acid sequences were not present in the testis-type protein. Northern and Southern blots demonstrated presence of transcripts with unspliced intron in rat sperm but not liver. Similarly, antibody, raised against a synthetic 12-amino acid peptide (p12) encoded by the unspliced intron, recognized in immunoblots a 54 kDa receptor protein in protein extracts from testis but not from liver. Immunofluorescence and immunogold electron microscopy studies demonstrated that both protein species localized on the plasma membrane surface of the head and tail of rat sperm. Furthermore, capacitated rat sperm preincubated with polyclonal antisera to RHL-2/3 or to the CRD of the liver-type galactosyl receptor showed a statistically significant decrease in the in vitro fertilization rate. We conclude that rat sperm galactosyl receptor may play a role in egg binding and that an undetermined molecular mechanism operates to generate two proteins with identical intracellular amino terminal domain but only one of them displays a CRD and associated Ca(2+)-binding

Cyborg lectins: novel leguminous lectins with unique specificities.

PubMed

Yamamoto, K; Maruyama, I N; Osawa, T

2000-01-01

Bauhinia purpurea lectin (BPA) is one of the beta-galactose-binding leguminous lectins. Leguminous lectins contain a long metal-binding loop, part of which determines their carbohydrate-binding specificities. Random mutations were introduced into a portion of the cDNA coding BPA that corresponds to the carbohydrate-binding loop of the lectin. An library of the mutant lectin expressed on the surface of lambda foo phages was screened by the panning method. Several phage clones with an affinity for mannose or N-acetylglucosamine were isolated. These results indicate the possibility of making artificial lectins (so-called "cyborg lectins") with distinct and desired carbohydrate-binding specificities.

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

Agglutination of Helicobacter pylori coccoids by lectins

PubMed Central

Khin, Mar Mar; Hua, Jie Song; Ng, Han Cong; Wadström, Torkel; Ho, Bow

2000-01-01

AIM: To study the agglutination pattern of Helicobacter pylori coccoid and spiral forms. METHODS: Assays of agglutination and agglutination inhibition were applied using fifteen commercial lectins. RESULTS: Strong agglutination was observed with mannose-specific Concanavalin A (Con A), fucose-specific Tetragonolobus purpureas (Lotus A) and N-acetyl glucosamine-specific Triticum vulgaris (WGA) lectins. Mannose and fucose specific lectins were reactive with all strains of H. pylori coccoids as compared to the spirals. Specific carbohydrates, glycoproteins and mucin were shown to inhibit H. pylori lectin-agglutination reactions. Pre-treatment of the bacterial cells with formalin and sulphuric acid did not alter the agglutination patterns with lectins. However, sodium periodate treatment of bacterial cells were shown to inhibit agglutination reaction with Con A, Lotus A and WGA lectins. On the contrary, enzymatic treatment of coccoids and spirals did not show marked inhibition of H. pylori lectin agglutination. Interes tingly, heating of H. pylori cells at 60 °C for 1 h was shown to augment the agglutination with all of the lectins tested. CONCLUSION: The considerable differences in lectin agglutination patterns seen among the two differentiated forms of H. pylori might be attributable to the structural changes during the events of morphological transformation, resulting in exposing or masking some of the sugar residues on the cell surface. Possibility of various sugar residues on the cell wall of the coccoids may allow them to bind to different carbohydrate receptors on gastric mucus and epithelial cells. The coccoids with adherence characteristics like the spirals could aid in the pathogenic process of Helicobacter infection. This may probably lead to different clinical outcome of H. pylori associated gastroduodenal disease. PMID:11819557

ESBL and MBL in Cefepime Resistant Pseudomonas aeruginosa: An Update from a Rural Area in Northern India

PubMed Central

Biswas, Debasis; Kakati, Barnali; Singh, Malvika

2016-01-01

Introduction Cefepime, a fourth generation cephalosporin, is widely used for the empirical treatment of serious infections in critically ill hospitalized patients. Pseudomonas aeruginosa (P. aeruginosa), one of the commonest bacteria causing nosocomial infections has a propensity to develop antibiotic resistance quite promptly. Aim We undertook this study to assess the efficacy of cefepime against current clinical isolates of P. aeruginosa and to study existence of different beta-lactamase enzymes among cefepime resistant P. aeruginosa isolates. Materials and Methods Total of 618 isolates of P. aeruginosa recovered consecutively from various clinical samples of a tertiary care hospital were analysed. Their Antimicrobial sensitivity profile against piperacilin (100μg), piperacillin/tazobactam (100μg/10μg), ceftazidime (30μg), cefoperazone (75μg), cefepime (30μg), ciprofloxacin (5μg), gentamycin (10μg), amikacin (30μg) and imipenem (10μg) (Himedia) was tested by Kirby-Bauer disc diffusion method (Clinical and Laboratory Standards Institute guidelines). We further looked for ESBL, MBL and ESBL + MBL co producers among the cefepime resistant isolates by two different methods (combined double disc synergy test, imipenem-EDTA combined disc test and vitek2). Results Among 618 consecutive clinical isolates of P. aeruginosa, we observed resistance to cefepime in 457 (74%) isolates. We observed resistance to ciprofloxacin (n=506, 82%) in maximum number of isolates followed by that to Gentamycin (n=475, 77%), amikacin (n=366, 60%), and cefoperazone (n=350, 56.6%). Among all our cefepime resistant P. aeruginosa isolates only 27(6%) were ESBL producers, 18(4%) MBL producers and 2(0.4%) were ESBL+ MBL co-producers. All the ESBL and MBL isolates were also tested by VITEK 2 advanced expert system (bioMırieux Vitek Systems Inc, Hazelwood, MO, France) which revealed a 100% concordance with the phenotypic method tested. Conclusion This paper highlights the need to

ESBL and MBL in Cefepime Resistant Pseudomonas aeruginosa: An Update from a Rural Area in Northern India.

PubMed

Kotwal, Aarti; Biswas, Debasis; Kakati, Barnali; Singh, Malvika

2016-04-01

Cefepime, a fourth generation cephalosporin, is widely used for the empirical treatment of serious infections in critically ill hospitalized patients. Pseudomonas aeruginosa (P. aeruginosa), one of the commonest bacteria causing nosocomial infections has a propensity to develop antibiotic resistance quite promptly. We undertook this study to assess the efficacy of cefepime against current clinical isolates of P. aeruginosa and to study existence of different beta-lactamase enzymes among cefepime resistant P. aeruginosa isolates. Total of 618 isolates of P. aeruginosa recovered consecutively from various clinical samples of a tertiary care hospital were analysed. Their Antimicrobial sensitivity profile against piperacilin (100μg), piperacillin/tazobactam (100μg/10μg), ceftazidime (30μg), cefoperazone (75μg), cefepime (30μg), ciprofloxacin (5μg), gentamycin (10μg), amikacin (30μg) and imipenem (10μg) (Himedia) was tested by Kirby-Bauer disc diffusion method (Clinical and Laboratory Standards Institute guidelines). We further looked for ESBL, MBL and ESBL + MBL co producers among the cefepime resistant isolates by two different methods (combined double disc synergy test, imipenem-EDTA combined disc test and vitek2). Among 618 consecutive clinical isolates of P. aeruginosa, we observed resistance to cefepime in 457 (74%) isolates. We observed resistance to ciprofloxacin (n=506, 82%) in maximum number of isolates followed by that to Gentamycin (n=475, 77%), amikacin (n=366, 60%), and cefoperazone (n=350, 56.6%). Among all our cefepime resistant P. aeruginosa isolates only 27(6%) were ESBL producers, 18(4%) MBL producers and 2(0.4%) were ESBL+ MBL co-producers. All the ESBL and MBL isolates were also tested by VITEK 2 advanced expert system (bioMırieux Vitek Systems Inc, Hazelwood, MO, France) which revealed a 100% concordance with the phenotypic method tested. This paper highlights the need to reconsider prescribing empirical antibiotics for Pseudomonas

Targeted delivery of antigen to hamster nasal lymphoid tissue with M-cell-directed lectins.

PubMed Central

Giannasca, P J; Boden, J A; Monath, T P

1997-01-01

The nasal cavity of a rodent is lined by an epithelium organized into distinct regional domains responsible for specific physiological functions. Aggregates of nasal lymphoid tissue (NALT) located at the base of the nasal cavity are believed to be sites of induction of mucosal immune responses to airborne antigens. The epithelium overlying NALT contains M cells which are specialized for the transcytosis of immunogens, as demonstrated in other mucosal tissues. We hypothesized that NALT M cells are characterized by distinct glycoconjugate receptors which influence antigen uptake and immune responses to transcytosed antigens. To identify glycoconjugates that may distinguish NALT M cells from other cells of the respiratory epithelium (RE), we performed lectin histochemistry on sections of the hamster nasal cavity with a panel of lectins. Many classes of glycoconjugates were found on epithelial cells in this region. While most lectins bound to sites on both the RE and M cells, probes capable of recognizing alpha-linked galactose were found to label the follicle-associated epithelium (FAE) almost exclusively. By morphological criteria, the FAE contains >90% M cells. To determine if apical glycoconjugates on M cells were accessible from the nasal cavity, an M-cell-selective lectin and a control lectin in parallel were administered intranasally to hamsters. The M-cell-selective lectin was found to specifically target the FAE, while the control lectin did not. Lectin bound to M cells in vivo was efficiently endocytosed, consistent with the role of M cells in antigen transport. Intranasal immunization with lectin-test antigen conjugates without adjuvant stimulated induction of specific serum immunoglobulin G, whereas antigen alone or admixed with lectin did not. The selective recognition of NALT M cells by a lectin in vivo provides a model for microbial adhesin-host cell receptor interactions on M cells and the targeted delivery of immunogens to NALT following intranasal

The C-type Lectin Langerin Functions as a Receptor for Attachment and Infectious Entry of Influenza A Virus.

PubMed

Ng, Wy Ching; Londrigan, Sarah L; Nasr, Najla; Cunningham, Anthony L; Turville, Stuart; Brooks, Andrew G; Reading, Patrick C

2016-01-01

It is well established that influenza A virus (IAV) attachment to and infection of epithelial cells is dependent on sialic acid (SIA) at the cell surface, although the specific receptors that mediate IAV entry have not been defined and multiple receptors may exist. Lec2 Chinese hamster ovary (CHO) cells are SIA deficient and resistant to IAV infection. Here we demonstrate that the expression of the C-type lectin receptor langerin in Lec2 cells (Lec2-Lg) rendered them permissive to IAV infection, as measured by replication of the viral genome, transcription of viral mRNA, and synthesis of viral proteins. Unlike SIA-dependent infection of parental CHO cells, IAV attachment and infection of Lec2-Lg cells was mediated via lectin-mediated recognition of mannose-rich glycans expressed by the viral hemagglutinin glycoprotein. Lec2 cells expressing endocytosis-defective langerin bound IAV efficiently but remained resistant to IAV infection, confirming that internalization via langerin was essential for infectious entry. Langerin-mediated infection of Lec2-Lg cells was pH and dynamin dependent, occurred via clathrin- and caveolin-mediated endocytic pathways, and utilized early (Rab5(+)) but not late (Rab7(+)) endosomes. This study is the first to demonstrate that langerin represents an authentic receptor that binds and internalizes IAV to facilitate infection. Moreover, it describes a unique experimental system to probe specific pathways and compartments involved in infectious entry following recognition of IAV by a single cell surface receptor. On the surface of host cells, sialic acid (SIA) functions as the major attachment factor for influenza A viruses (IAV). However, few studies have identified specific transmembrane receptors that bind and internalize IAV to facilitate infection. Here we identify human langerin as a transmembrane glycoprotein that can act as an attachment factor and a bone fide endocytic receptor for IAV infection. Expression of langerin by an SIA

The C-type Lectin Langerin Functions as a Receptor for Attachment and Infectious Entry of Influenza A Virus

PubMed Central

Ng, Wy Ching; Londrigan, Sarah L.; Nasr, Najla; Cunningham, Anthony L.; Turville, Stuart; Brooks, Andrew G.

2015-01-01

ABSTRACT It is well established that influenza A virus (IAV) attachment to and infection of epithelial cells is dependent on sialic acid (SIA) at the cell surface, although the specific receptors that mediate IAV entry have not been defined and multiple receptors may exist. Lec2 Chinese hamster ovary (CHO) cells are SIA deficient and resistant to IAV infection. Here we demonstrate that the expression of the C-type lectin receptor langerin in Lec2 cells (Lec2-Lg) rendered them permissive to IAV infection, as measured by replication of the viral genome, transcription of viral mRNA, and synthesis of viral proteins. Unlike SIA-dependent infection of parental CHO cells, IAV attachment and infection of Lec2-Lg cells was mediated via lectin-mediated recognition of mannose-rich glycans expressed by the viral hemagglutinin glycoprotein. Lec2 cells expressing endocytosis-defective langerin bound IAV efficiently but remained resistant to IAV infection, confirming that internalization via langerin was essential for infectious entry. Langerin-mediated infection of Lec2-Lg cells was pH and dynamin dependent, occurred via clathrin- and caveolin-mediated endocytic pathways, and utilized early (Rab5+) but not late (Rab7+) endosomes. This study is the first to demonstrate that langerin represents an authentic receptor that binds and internalizes IAV to facilitate infection. Moreover, it describes a unique experimental system to probe specific pathways and compartments involved in infectious entry following recognition of IAV by a single cell surface receptor. IMPORTANCE On the surface of host cells, sialic acid (SIA) functions as the major attachment factor for influenza A viruses (IAV). However, few studies have identified specific transmembrane receptors that bind and internalize IAV to facilitate infection. Here we identify human langerin as a transmembrane glycoprotein that can act as an attachment factor and a bone fide endocytic receptor for IAV infection. Expression of

Prospective Observational Study on the Association Between Serum Mannose-Binding Lectin Levels and Severe Outcome in Critically Ill Patients with Pandemic Influenza Type A (H1N1) Infection.

PubMed

Zogheib, Elie; Nyga, Remy; Cornu, Marjorie; Sendid, Boualem; Monconduit, Julien; Jounieaux, Vincent; Maizel, Julien; Segard, Christine; Chouaki, Taïeb; Dupont, Hervé

2018-02-01

Mannose-binding lectin (MBL) plays an important role in the innate immune response. In addition to activating the complement, MBL can induce cytokine production and contribute to a deleterious inflammatory response with severe A(H1N1)pdm09 virus infection. Our aim was to determine if serum MBL levels correlate with the risk of mortality in intensive care units (ICU) patients with A(H1N1)pdm09 infection. Prospective observational study was performed in ICU patients with acute respiratory distress syndrome due to influenza A(H1N1)pdm09 virus. Demographic characteristics and severity indices were recorded at ICU admission. MBL was assayed from blood drawn at influenza diagnosis within 24-48 h following the ICU admission. Outcomes were compared according to MBL levels. Results are expressed as median and interquartile range. Serum MBL levels were studied in 27 patients (age: 56 [IQR 29] years) with severe A(H1N1)pdm09 infection and in 70 healthy controls. Median admission SAPSII and SOFA scores were 49 [IQR 26] and 12 [IQR 5], respectively. Mortality rate after a 30-day was 37%. MBL was significantly higher in non-survivors (3741 [IQR 2336] ng/ml) vs survivors (215 [IQR 1307] ng/ml), p = 0.006, as well as control group (1814 [IQR 2250] ng/ml), p = 0.01. In contrast, MBL levels in survivors group were significantly lower than the controls group (215 [IQR 1307] ng/ml vs. 1814 [IQR 2250] ng/ml, p = 0.005). MBL cut-off > 1870 ng/ml had a sensitivity of 80% and a specificity of 88.2% for mortality [AUC = 0.82 (95% CI 0.63-0.94)]. Kaplan-Meier analysis demonstrated a strong association between MBL levels and mortality (log-rank 7.8, p = 0.005). MBL > 1870 ng/ml was independently associated with mortality (HR = 8.7, 95% CI 1.2-29.1, p = 0.007). This study shows that baseline MBL > 1870 ng/ml is associated with higher mortality in ICU patients with severe A(H1N1)pdm09 infection.

L-Asparaginase lowers plasma antithrombin and mannan-binding-lectin levels: Impact on thrombotic and infectious events in children with acute lymphoblastic leukemia.

PubMed

Merlen, Clémence; Bonnefoy, Arnaud; Wagner, Eric; Dedeken, Laurence; Leclerc, Jean-Marie; Laverdière, Caroline; Rivard, Georges-Etienne

2015-08-01

L-asparaginase, a key therapeutic agent in the management of patients with acute lymphoblastic leukemia (ALL), dramatically impairs hepatic protein synthesis. We investigated the effects of prolonged exposure to L-asparaginase on antithrombin (AT), fibrinogen and mannan-binding-lectin (MBL) levels, and on the occurrence of thrombotic events (TE) and febrile neutropenia episodes (FN) in pediatric patients. Protein levels were measured in 97 children during 30 weeks of chemotherapy with L-asparaginase and up to 1 year following remission. TE and FN episodes were recorded during this period. Median AT level decreased from 0.96 IU/mL prior to treatment (range: 0.69-1.38) to 0.55 IU/mL (0.37-0.76) during therapy. Fibrinogen and MBL decreased from 3.18 g/L (1.29-7.28) and 1,177 ng/mL (57-5,343) to 1.56 g/L (0.84-2.13) and 193 ng/mL (57-544), respectively. All three proteins had recovered 1-4 weeks after L-asparaginase cessation. TE were reported in 22 (23%) patients. Of these, 11 occurred after a median of 10 administrations of L-asparaginase. Fifty-one FN were associated with infections, of which 36 occurred during treatment with L-asparaginase. Patients with low levels of MBL at diagnosis were at higher risk of FN associated with infections (RR = 1.59, 95%CI: 1.026-2.474). Both AT and MBL decreases were moderately correlated with fibrinogen (r = 0.51 and 0.58, respectively). Children with ALL are exposed to significant decrease in AT, fibrinogen and MBL levels, and concomitant increased risk of thrombosis and FN with infection during L-asparaginase treatment. Measuring plasma levels of these liver-derived proteins could help predict the occurrence of adverse events. © 2015 Wiley Periodicals, Inc.

E3 ubiquitin ligase CHIP interacts with C-type lectin-like receptor CLEC-2 and promotes its ubiquitin-proteasome degradation.

PubMed

Shao, Miaomiao; Li, Lili; Song, Shushu; Wu, Weicheng; Peng, Peike; Yang, Caiting; Zhang, Mingming; Duan, Fangfang; Jia, Dongwei; Zhang, Jie; Wu, Hao; Zhao, Ran; Wang, Lan; Ruan, Yuanyuan; Gu, Jianxin

2016-10-01

C-type lectin-like receptor 2 (CLEC-2) was originally identified as a member of non-classical C-type lectin-like receptors in platelets and immune cells. Activation of CLEC-2 is involved in thrombus formation, lymphatic/blood vessel separation, platelet-mediated tumor metastasis and immune response. Nevertheless, the regulation of CLEC-2 expression is little understood. In this study, we identified that the C terminus of Hsc70-interacting protein (CHIP) interacted with CLEC-2 by mass spectrometry analysis, and CHIP decreased the protein expression of CLEC-2 through lysine-48-linked ubiquitination and proteasomal degradation. Deleted and point mutation also revealed that CHIP controlled CLEC-2 protein expression via both tetratricopeptide repeats (TPR) domain and Ubox domain in a HSP70/90-independent manner. Moreover, reduced CHIP expression was associated with decreased CLEC-2 polyubiquitination and increased CLEC-2 protein levels in PMA-induced differentiation of THP-1 monocytes into macrophages. These results indicate that CLEC-2 is the target substrate of E3 ubiquitin ligase CHIP, and suggest that the CHIP/CLEC-2 axis may play an important role in the modulation of immune response. Copyright © 2016 Elsevier Inc. All rights reserved.

The effect of the lectin from Cherax quadricarinatus on its granular hemocytes.

PubMed

Sánchez-Salgado, José Luis; Pereyra, Mohamed Alí; Agundis, Concepción; Vivanco-Rojas, Oscar; Rosales, Carlos; Pascual, Cristina; Alpuche-Osorno, Juan José; Zenteno, Edgar

2018-06-01

In crustaceans, lectins and hemocytes of the innate immune system provide the first line of defense. Although evidence points to the potential role of lectins in regulating hemocyte activity, the processes underlying the lectin activation have not been evaluated. In the present study, the receptor for CqL, a humoral lectin from Cherax quadricarinatus specific for galactose/sialic acid, was identified in a granular subset of hemocytes. The CqL receptor (CqLR) is a 490-kDa glycoprotein, composed of four identical 120-kDa subunits. As shown by immunohistochemistry, CqL at 7.5 μg/mL as optimal dose, after 2 min, induced, specifically on granular hemocytes, increased phosphorylation of serine (152%), threonine (192%), and tyrosine (242%) as compared with non-treated hemocytes; moreover, CqL induced increased generation of reactive oxygen species (ROS). Specific kinase inhibitors showed inhibition (P < 0.001) of ROS production induced by CqL. These results strongly suggest that CqL actively participated in the generation of ROS through kinases induced by a CqLR in a subset of granular hemocytes of the crayfish C. quadricarinatus. The results provide strong evidence that CqL activates, through specific granular hemocytes, receptors that modulate cellular functions in C. quadricarinatus. Copyright © 2018 Elsevier Ltd. All rights reserved.

Quantitative evaluation of lectin-reactive glycoforms of α(1)-acid glycoprotein using lectin affinity capillary electrophoresis with fluorescence detection.

PubMed

Shimura, Kiyohito; Tamura, Mayumi; Toda, Tosifusa; Yazawa, Shin; Kasai, Ken-ichi

2011-08-01

α(1)-Acid glycoprotein (AGP) was previously shown to be a marker candidate of disease progression and prognosis of patients with malignancies by analysis of its glycoforms via lectins. Herein, affinity capillary electrophoresis of fluorescein-labeled AGP using lectins with the aid of laser-induced fluorescence detection was developed for quantitative evaluation of the fractional ratios of concanavalin A-reactive or Aleuria aurantia lectin-reactive AGP. Labeled AGP was applied at the anodic end of a fused-silica capillary (50 μm id, 360 μm od, 27 cm long) coated with linear polyacryloyl-β-alanyl-β-alanine, and electrophoresis was carried out for about 10 min in 60 mM 3-morpholinopropane-1-sulfonic acid-NaOH buffer (pH 7.35). Addition of the lectins to the anode buffer resulted in the separation of lectin-reactive glycoform peaks from lectin-non-reactive glycoform peaks. Quantification of the peak area of each group revealed that the percent of lectin-reactive AGP is independent of a labeling ratio ranging from 0.4 to 1.5 mol fluorescein/mol AGP, i.e. the standard deviation of 0.5% for an average of 59.9% (n=3). In combination with a facile procedure for micro-purification of AGP from serum, the present procedure, marking the reactivity of AGP with lectins, should be useful in determining the prognosis for a large number of patients with malignancies. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of the lectins wheat germ agglutinin (WGA) and Ulex europaeus agglutinin (UEA-I) on the alpha-amylase secretion of rat pancreas in vitro and in vivo.

PubMed

Mikkat, U; Damm, I; Schröder, G; Schmidt, K; Wirth, C; Weber, H; Jonas, L

1998-05-01

Lectins are able to bind to cholecystokinin (CCK) receptors and other glycosylated membrane proteins. The lectins wheat germ agglutinin (WGA) and Ulex europaeus agglutinin (UEA-I) are used for affinity chromatography to isolate the highly glycosylated CCK-A receptor of pancreatic acinar cells. According to the working hypothesis that lectin binding to the CCK receptor should alter the ligand-receptor interaction, the effect of WGA and UEA-I on CCK-8-induced enzyme secretion was studied on isolated rat pancreatic acini in vitro. In vitro both lectins showed a dosage-dependent inhibition of CCK-8-induced alpha-amylase secretion of acini over 60 min. WGA showed a strong inhibitory effect on amylase secretion, approximately 40%, in vitro. UEA-I caused a smaller, but significant decrease, approximately 20%, in enzyme secretion of isolated acini. Additionally, both lectins inhibited cerulein/secretin- or cerulein-induced pancreatic secretion of rats in vivo, but not after secretin alone. The results are discussed with respect to a possible influence of both lectins on the interaction of CCK or cerulein with the CCK-A receptor.

Targeting the C-type lectins-mediated host-pathogen interactions with dextran.

PubMed

Pustylnikov, Sergey; Sagar, Divya; Jain, Pooja; Khan, Zafar K

2014-01-01

Dextran, the α-1,6-linked glucose polymer widely used in biology and medicine, promises new applications. Linear dextran applied as a blood plasma substitute demonstrates a high rate of biocompatibility. Dextran is present in foods, drugs, and vaccines and in most cases is applied as a biologically inert substance. In this review we analyze dextran's cellular uptake principles, receptor specificity and, therefore, its ability to interfere with pathogen-lectin interactions: a promising basis for new antimicrobial strategies. Dextran-binding receptors in humans include the DC-SIGN (dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin) family receptors: DC-SIGN (CD209) and L-SIGN (the liver and lymphatic endothelium homologue of DC-SIGN), the mannose receptor (CD206), and langerin. These receptors take part in the uptake of pathogens by dendritic cells and macrophages and may also participate in the modulation of immune responses, mostly shown to be beneficial for pathogens per se rather than host(s). It is logical to predict that owing to receptor-specific interactions, dextran or its derivatives can interfere with these immune responses and improve infection outcome. Recent data support this hypothesis. We consider dextran a promising molecule for the development of lectin-glycan interaction-blocking molecules (such as DC-SIGN inhibitors) that could be applied in the treatment of diseases including tuberculosis, influenza, hepatitis B and C, human immunodeficiency virus infection and AIDS, etc. Dextran derivatives indeed change the pathology of infections dependent on DC-SIGN and mannose receptors. Complete knowledge of specific dextran-lectin interactions may also be important for development of future dextran applications in biological research and medicine.

LecRK-V, an L-type lectin receptor kinase in Haynaldia villosa, plays positive role in resistance to wheat powdery mildew.

PubMed

Wang, Zongkuan; Cheng, Jiangyue; Fan, Anqi; Zhao, Jia; Yu, Zhongyu; Li, Yingbo; Zhang, Heng; Xiao, Jin; Muhammad, Faheem; Wang, Haiyan; Cao, Aizhong; Xing, Liping; Wang, Xiue

2018-01-01

Plant sense potential microbial pathogen using pattern recognition receptors (PRRs) to recognize pathogen-associated molecular patterns (PAMPs). The Lectin receptor-like kinase genes (LecRKs) are involved in various cellular processes mediated by signal transduction pathways. In the present study, an L-type lectin receptor kinase gene LecRK-V was cloned from Haynaldia villosa, a diploid wheat relative which is highly resistant to powdery mildew. The expression of LecRK-V was rapidly up-regulated by Bgt inoculation and chitin treatment. Its transcript level was higher in the leaves than in roots, culms, spikes and callus. Single-cell transient overexpression of LecRK-V led to decreased haustorium index in wheat variety Yangmai158, which is powdery mildew susceptible. Stable transformation LecRK-V into Yangmai158 significantly enhanced the powdery mildew resistance at both seedling and adult stages. At seedling stage, the transgenic line was highly resistance to 18 of the tested 23 Bgt isolates, hypersensitive responses (HR) were observed for 22 Bgt isolates, and more ROS at the Bgt infection sites was accumulated. These indicated that LecRK-V confers broad-spectrum resistance to powdery mildew, and ROS and SA pathways contribute to the enhanced powdery mildew resistance in wheat. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Refolding and characterization of the functional ligand-binding domain of human lectin-like oxidized LDL receptor.

PubMed

Xie, Qiuhong; Matsunaga, Shigeru; Shi, Xiaohua; Ogawa, Setsuko; Niimi, Setsuko; Wen, Zhesheng; Tokuyasu, Ken; Machida, Sachiko

2003-11-01

Lectin-like oxidized low-density lipoprotein receptor (LOX-1), a type II membrane protein that can recognize a variety of structurally unrelated macromolecules, plays an important role in host defense and is implicated in atherogenesis. To understand the interaction between human LOX-1 and its ligands, in this study the functional C-type lectin-like domain (CTLD) of LOX-1 was reconstituted at high efficiency from inactive aggregates in Escherichia coli using a refolding technique based on an artificial chaperone. The CD spectra of the purified domain suggested that the domain has alpha-helical structure and the blue shift of Trp residues was observed on refolding of the domain. Like wild-type hLOX-1, the refolded CTLD domain was able to bind modified LDL. Thus, even though CTLD contains six Cys residues that form disulfide bonds, it recovered its specific binding ability on refolding. This suggests that the correct disulfide bonds in CTLD were formed by the artificial chaperone technique. Although the domain lacked N-glycosylation, it showed high affinity for its ligand in surface plasmon resonance experiments. Thus, unglycosylated CTLD is sufficient for binding modified LDL.

The Macrophage Galactose-Type Lectin Can Function as an Attachment and Entry Receptor for Influenza Virus

PubMed Central

Ng, Wy Ching; Liong, Stella; Tate, Michelle D.; Irimura, Tatsuro; Denda-Nagai, Kaori; Brooks, Andrew G.; Londrigan, Sarah L.

2014-01-01

Specific protein receptors that mediate internalization and entry of influenza A virus (IAV) have not been identified for any cell type. Sialic acid (SIA), the primary attachment factor for IAV hemagglutinin, is expressed by numerous cell surface glycoproteins and glycolipids, confounding efforts to identify specific receptors involved in virus infection. Lec1 Chinese hamster ovary (CHO) epithelial cells express cell surface SIA and bind IAV yet are largely resistant to infection. Here, we demonstrate that expression of the murine macrophage galactose-type lectin 1 (MGL1) by Lec1 cells enhanced Ca2+-dependent IAV binding and restored permissivity to infection. Lec1 cells expressing MGL1 were infected in the presence or absence of cell surface SIA, indicating that MGL1 can act as a primary receptor or as a coreceptor with SIA. Lec1 cells expressing endocytosis-deficient MGL1 mediated Ca2+-dependent IAV binding but were less sensitive to IAV infection, indicating that direct internalization via MGL1 can result in cellular infection. Together, these studies identify MGL1 as a cell surface glycoprotein that can act as an authentic receptor for both attachment and infectious entry of IAV. PMID:24257596

High-Dose Mannose-Binding Lectin Therapy for Ebola Virus Infection

DTIC Science & Technology

2010-06-01

viruses . N-glycosylation of viral envelopes is an important such target shared between in- fluenza, HIV, HCV, West Nile virus , SARS-CoV, Hendra virus ...host cells. Therefore, MBL preferentially recognizes glycosylated viruses including influenza virus , human immunodeficiency virus , severe acute...respiratory syndrome coronovirus (SARS-CoV), Ebola virus , and Marburg virus . It also recognizes many glycosylated gram- positive and gram-negative bacteria [1

AmpliSeq Screening of Genes Encoding the C-Type Lectin Receptors and Their Signaling Components Reveals a Common Variant in MASP1 Associated with Pulmonary Tuberculosis in an Indian Population.

PubMed

Klassert, Tilman E; Goyal, Surabhi; Stock, Magdalena; Driesch, Dominik; Hussain, Abid; Berrocal-Almanza, Luis Carlos; Myakala, Rajashekar; Sumanlatha, Gaddam; Valluri, Vijayalakshmi; Ahmed, Niyaz; Schumann, Ralf R; Flores, Carlos; Slevogt, Hortense

2018-01-01

Tuberculosis (TB) is a multifactorial disease governed by bacterial, host and environmental factors. On the host side, growing evidence shows the crucial role that genetic variants play in the susceptibility to Mycobacterium tuberculosis (Mtb) infection. Such polymorphisms have been described in genes encoding for different cytokines and pattern recognition receptors (PRR), including numerous Toll-like receptors (TLRs). In recent years, several members of the C-type lectin receptors (CTLRs) have been identified as key PRRs in TB pathogenesis. Nevertheless, studies to date have only addressed particular genetic polymorphisms in these receptors or their related pathways in relation with TB. In the present study, we screened the main CTLR gene clusters as well as CTLR pathway-related genes for genetic variation associated with pulmonary tuberculosis (PTB). This case-control study comprised 144 newly diagnosed pulmonary TB patients and 181 healthy controls recruited at the Bhagwan Mahavir Medical Research Center (BMMRC), Hyderabad, India. A two-stage study was employed in which an explorative AmpliSeq-based screening was followed by a validation phase using iPLEX MassARRAY. Our results revealed one SNP (rs3774275) in MASP1 significantly associated with PTB in our population (joint analysis p  = 0.0028). Furthermore, serum levels of MASP1 were significantly elevated in TB patients when compared to healthy controls. Moreover, in the present study we could observe an impact of increased MASP1 levels on the lectin pathway complement activity in vitro . In conclusion, our results demonstrate a significant association of MASP1 polymorphism rs3774275 and MASP1 serum levels with the development of pulmonary TB. The present work contributes to our understanding of host-Mtb interaction and reinforces the critical significance of mannose-binding lectin and the lectin-complement pathway in Mtb pathogenesis. Moreover, it proposes a MASP1 polymorphism as a potential genetic

AmpliSeq Screening of Genes Encoding the C-Type Lectin Receptors and Their Signaling Components Reveals a Common Variant in MASP1 Associated with Pulmonary Tuberculosis in an Indian Population

PubMed Central

Klassert, Tilman E.; Goyal, Surabhi; Stock, Magdalena; Driesch, Dominik; Hussain, Abid; Berrocal-Almanza, Luis Carlos; Myakala, Rajashekar; Sumanlatha, Gaddam; Valluri, Vijayalakshmi; Ahmed, Niyaz; Schumann, Ralf R.; Flores, Carlos; Slevogt, Hortense

2018-01-01

Tuberculosis (TB) is a multifactorial disease governed by bacterial, host and environmental factors. On the host side, growing evidence shows the crucial role that genetic variants play in the susceptibility to Mycobacterium tuberculosis (Mtb) infection. Such polymorphisms have been described in genes encoding for different cytokines and pattern recognition receptors (PRR), including numerous Toll-like receptors (TLRs). In recent years, several members of the C-type lectin receptors (CTLRs) have been identified as key PRRs in TB pathogenesis. Nevertheless, studies to date have only addressed particular genetic polymorphisms in these receptors or their related pathways in relation with TB. In the present study, we screened the main CTLR gene clusters as well as CTLR pathway-related genes for genetic variation associated with pulmonary tuberculosis (PTB). This case-control study comprised 144 newly diagnosed pulmonary TB patients and 181 healthy controls recruited at the Bhagwan Mahavir Medical Research Center (BMMRC), Hyderabad, India. A two-stage study was employed in which an explorative AmpliSeq-based screening was followed by a validation phase using iPLEX MassARRAY. Our results revealed one SNP (rs3774275) in MASP1 significantly associated with PTB in our population (joint analysis p = 0.0028). Furthermore, serum levels of MASP1 were significantly elevated in TB patients when compared to healthy controls. Moreover, in the present study we could observe an impact of increased MASP1 levels on the lectin pathway complement activity in vitro. In conclusion, our results demonstrate a significant association of MASP1 polymorphism rs3774275 and MASP1 serum levels with the development of pulmonary TB. The present work contributes to our understanding of host-Mtb interaction and reinforces the critical significance of mannose-binding lectin and the lectin-complement pathway in Mtb pathogenesis. Moreover, it proposes a MASP1 polymorphism as a potential genetic marker

Studies on the interaction of the Sophora japonica lectin and concanavalin A with erythrocytes and lymphocytes.

PubMed Central

Poretz, R D; Barth, R F

1976-01-01

The agglutinating activity of lectins from the seeds of Sophora japonica and Canavalia ensiformis (concanavalin A) with human and murine erythrocytes and lymphocytes have been compared to one another and related to the mitogenic and immunosuppressive properties of these purified proteins. The S. japonica lectin, which demonstrates blood group specificity, is more active than concanavalin A with human erythrocytes, but has a much lower reactivity than concanavalin A with murine red blood cells. Ficin treatment of human erythrocytes results in an increase in agglutinability by both lectins as well as causing the appearance of S. japonica lectin receptors on type O cells. Treatment of murine reythrocytes with ficin alone or followed by beta-galactosidase causes the cells to be more reactive with concanavalin A. Beta-Galactosidase alone has no observable affect on the cells. In contrast, the agglutinability of cells by the S. japonica lectin increases after ficin treatment but is not affected by beta-galaetosidose treatment either after or in the absence of ficinization. Murine lymphocytes react with both lectins in a manner paralleling the agglutination patterns of murine erythrocytes. The S. japonica lectin appears to be devoid of mitogenic and immuno-suppressive activity, in contrast to concanavalin A which suppresses the T helper-dependent antibody response to sheep erythrocytes. These results are discussed in terms of the types of lectin receptors on lymphocytes related to agglutination, induction of blastogenesis and immuno-suppression. PMID:955676

Mistletoe lectins enhance immune responses to intranasally co-administered herpes simplex virus glycoprotein D2

PubMed Central

Lavelle, E C; Grant, G; Pusztai, A; Pfüller, U; Leavy, O; McNeela, E; Mills, K H G; O'Hagan, D T

2002-01-01

The mucosal adjuvant properties of the three type 2 ribosome-inactivating proteins (RIPs) from the European mistletoe, Viscum album L., were investigated. Mistletoe lectins were compared with cholera toxin (CT) as adjuvants when delivered nasotracheally together with herpes simplex virus glycoprotein D2 (gD2). All three mistletoe lectins (MLI, MLII, MLIII) were potent mucosal adjuvants. Co-administration of MLI, MLII or MLIII with gD2 led to significantly higher levels of gD2-specific mucosal immunoglobulin A (IgA) and systemic immunoglobulin G (IgG) antibody than when the antigen was delivered alone. The levels of antibodies induced were similar to those generated in mice immunized with gD2 and the potent mucosal adjuvant CT. Administration of ML1 with gD2 enhanced the antigen-specific splenic T-cell proliferative response. Interleukin-5 (IL-5), but not interferon-γ (IFN-γ), was detected in supernatants from splenocytes stimulated in vitro with gD2. This indicates that MLI enhanced type 2 T-helper cell (Th2) responses to the bystander antigen, gD2. Analysis of the gD2- and lectin-specific IgG subclass titres in mice immunized with gD2 and MLI, MLII or MLIII revealed a high ratio of IgG1 : IgG2a, which is compatible with the selective induction of Th2-type immune responses. PMID:12383207

Glycans: bioactive signals decoded by lectins.

PubMed

Gabius, Hans-Joachim

2008-12-01

The glycan part of cellular glycoconjugates affords a versatile means to build biochemical signals. These oligosaccharides have an exceptional talent in this respect. They surpass any other class of biomolecule in coding capacity within an oligomer (code word). Four structural factors account for this property: the potential for variability of linkage points, anomeric position and ring size as well as the aptitude for branching (first and second dimensions of the sugar code). Specific intermolecular recognition is favoured by abundant potential for hydrogen/co-ordination bonds and for C-H/pi-interactions. Fittingly, an array of protein folds has developed in evolution with the ability to select certain glycans from the natural diversity. The thermodynamics of this reaction profits from the occurrence of these ligands in only a few energetically favoured conformers, comparing favourably with highly flexible peptides (third dimension of the sugar code). Sequence, shape and local aspects of glycan presentation (e.g. multivalency) are key factors to regulate the avidity of lectin binding. At the level of cells, distinct glycan determinants, a result of enzymatic synthesis and dynamic remodelling, are being defined as biomarkers. Their presence gains a functional perspective by co-regulation of the cognate lectin as effector, for example in growth regulation. The way to tie sugar signal and lectin together is illustrated herein for two tumour model systems. In this sense, orchestration of glycan and lectin expression is an efficient means, with far-reaching relevance, to exploit the coding potential of oligosaccharides physiologically and medically.

Verification and extension of the MBL technique for photo resist pattern shape measurement

NASA Astrophysics Data System (ADS)

Isawa, Miki; Tanaka, Maki; Kazumi, Hideyuki; Shishido, Chie; Hamamatsu, Akira; Hasegawa, Norio; De Bisschop, Peter; Laidler, David; Leray, Philippe; Cheng, Shaunee

2011-03-01

In order to achieve pattern shape measurement with CD-SEM, the Model Based Library (MBL) technique is in the process of development. In this study, several libraries which consisted by double trapezoid model placed in optimum layout, were used to measure the various layout patterns. In order to verify the accuracy of the MBL photoresist pattern shape measurement, CDAFM measurements were carried out as a reference metrology. Both results were compared to each other, and we confirmed that there is a linear correlation between them. After that, to expand the application field of the MBL technique, it was applied to end-of-line (EOL) shape measurement to show the capability. Finally, we confirmed the possibility that the MBL could be applied to more local area shape measurement like hot-spot analysis.

[Association between expression of lectin type receptors by natural killers and intensity of liver fibrosis during chronic hepatitis C].

PubMed

Malova, E S; Balmasova, I P; Iuschuk, N D; Shmeleva, E V; Eremina, O F

2010-01-01

To study functional activity of natural killers on different stages of fibrosis during chronic hepatitis C. Functional activity of CD3-/CD56+/CD16+ lymphocytes measured as expression of natural killers receptors (NKR) and natural cytotoxicity receptors (NCR) was assessed by flow cytometry. At stage I of fibrosis, decrease of number of CD3-/CD56+/NKG2D+ cells was observed, whereas at precirrhotic stage III--sharp decrease of CD3-/CD56+/CD94+ and CD3-/ CD56+/NKG2D+ populations, and at cirrhotic stage--decrease of number of CD3-/CD56+/ NKG2D+ cells and increase of cytolytic activity of natural killers carrying CD107a marker compared to precirrhotic stage. Obtained data demonstrate that natural killers during chronic hepatitis C receive regulatory signals mainly through lectin type receptors (CD94 and NKG2D).

Lectin engineering, a molecular evolutionary approach to expanding the lectin utilities.

PubMed

Hu, Dan; Tateno, Hiroaki; Hirabayashi, Jun

2015-04-27

In the post genomic era, glycomics--the systematic study of all glycan structures of a given cell or organism--has emerged as an indispensable technology in various fields of biology and medicine. Lectins are regarded as "decipherers of glycans", being useful reagents for their structural analysis, and have been widely used in glycomic studies. However, the inconsistent activity and availability associated with the plant-derived lectins that comprise most of the commercially available lectins, and the limit in the range of glycan structures covered, have necessitated the development of innovative tools via engineering of lectins on existing scaffolds. This review will summarize the current state of the art of lectin engineering and highlight recent technological advances in this field. The key issues associated with the strategy of lectin engineering including selection of template lectin, construction of a mutagenesis library, and high-throughput screening methods are discussed.

CancerLectinDB: a database of lectins relevant to cancer.

PubMed

Damodaran, Deepa; Jeyakani, Justin; Chauhan, Alok; Kumar, Nirmal; Chandra, Nagasuma R; Surolia, Avadhesha

2008-04-01

The role of lectins in mediating cancer metastasis, apoptosis as well as various other signaling events has been well established in the past few years. Data on various aspects of the role of lectins in cancer is being accumulated at a rapid pace. The data on lectins available in the literature is so diverse, that it becomes difficult and time-consuming, if not impossible to comprehend the advances in various areas and obtain the maximum benefit. Not only do the lectins vary significantly in their individual functional roles, but they are also diverse in their sequences, structures, binding site architectures, quaternary structures, carbohydrate affinities and specificities as well as their potential applications. An organization of these seemingly independent data into a common framework is essential in order to achieve effective use of all the data towards understanding the roles of different lectins in different aspects of cancer and any resulting applications. An integrated knowledge base (CancerLectinDB) together with appropriate analytical tools has therefore been developed for lectins relevant for any aspect of cancer, by collating and integrating diverse data. This database is unique in terms of providing sequence, structural, and functional annotations for lectins from all known sources in cancer and is expected to be a useful addition to the number of glycan related resources now available to the community. The database has been implemented using MySQL on a Linux platform and web-enabled using Perl-CGI and Java tools. Data for individual lectins pertain to taxonomic, biochemical, domain architecture, molecular sequence and structural details as well as carbohydrate specificities. Extensive links have also been provided for relevant bioinformatics resources and analytical tools. Availability of diverse data integrated into a common framework is expected to be of high value for various studies on lectin cancer biology. CancerLectinDB can be accessed through

Histological and Lectin Histochemical Studies on the Olfactory and Respiratory Mucosae of the Sheep

PubMed Central

IBRAHIM, Dalia; NAKAMUTA, Nobuaki; TANIGUCHI, Kazumi; YAMAMOTO, Yoshio; TANIGUCHI, Kazuyuki

2013-01-01

ABSTRACT 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

In vitro C3 Deposition on Cryptococcus Capsule Occurs Via Multiple Complement Activation Pathways

PubMed Central

Mershon-Shier, Kileen L.; Vasuthasawat, Alex; Takahashi, Kazue; Morrison, Sherie L.; Beenhouwer, David O.

2011-01-01

Complement can be activated via three pathways: classical, alternative, and lectin. Cryptococcus gattii and C. neoformans are closely related fungal pathogens possessing a polysaccharide capsule composed mainly of glucuronoxylomannan (GXM), which serves as a site for complement activation and deposition of complement components. We determined C3 deposition on Cryptococcus spp. by flow cytometry and confocal microscopy after incubation with serum from C57BL/6J mice as well as mice deficient in complement components C4, C3, factor B, and mannose binding lectin (MBL). C. gattii and C. neoformans activate complement in EGTA-treated serum indicating that they can activate the alternative pathway. However, complement activation was seen with factor B−/− serum suggesting activation could also take place in the absence of a functional alternative pathway. Furthermore, we uncovered a role for C4 in the alternative pathway activation by Cryptococcus spp. We also identified an unexpected and complex role for MBL in complement activation by Cryptococcus spp. No complement activation occurred in the absence of MBL-A and -C proteins although activation took place when the lectin binding activity of MBL was disrupted by calcium chelation. In addition, alternative pathway activation by C. neoformans required both MBL-A and -C, while either MBL-A or -C was sufficient for alternative pathway activation by C. gattii. Thus, complement activation by Cryptococcus spp. can take place through multiple pathways and complement activation via the alternative pathway requires the presence of C4 and MBL proteins. PMID:21723612

Lectin-Array Blotting.

PubMed

Pazos, Raquel; Echevarria, Juan; Hernandez, Alvaro; Reichardt, Niels-Christian

2017-09-01

Aberrant protein glycosylation is a hallmark of cancer, infectious diseases, and autoimmune or neurodegenerative disorders. Unlocking the potential of glycans as disease markers will require rapid and unbiased glycoproteomics methods for glycan biomarker discovery. The present method is a facile and rapid protocol for qualitative analysis of protein glycosylation in complex biological mixtures. While traditional lectin arrays only provide an average signal for the glycans in the mixture, which is usually dominated by the most abundant proteins, our method provides individual lectin binding profiles for all proteins separated in the gel electrophoresis step. Proteins do not have to be excised from the gel for subsequent analysis via the lectin array but are transferred by contact diffusion from the gel to a glass slide presenting multiple copies of printed lectin arrays. Fluorescently marked glycoproteins are trapped by the printed lectins via specific carbohydrate-lectin interactions and after a washing step their binding profile with up to 20 lectin probes is analyzed with a fluorescent scanner. The method produces the equivalent of 20 lectin blots in a single experiment, giving detailed insight into the binding epitopes present in the fractionated proteins. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

Isolation and characterization of rhamnose-binding lectins from eggs of steelhead trout (Oncorhynchus mykiss) homologous to low density lipoprotein receptor superfamily.

PubMed

Tateno, H; Saneyoshi, A; Ogawa, T; Muramoto, K; Kamiya, H; Saneyoshi, M

1998-07-24

Two L-rhamnose-binding lectins named STL1 and STL2 were isolated from eggs of steelhead trout (Oncorhynchus mykiss) by affinity chromatography and ion exchange chromatography. The apparent molecular masses of purified STL1 and STL2 were estimated to be 84 and 68 kDa, respectively, by gel filtration chromatography. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and matrix-assisted laser desorption ionization time of flight mass spectrometry of these lectins revealed that STL1 was composed of noncovalently linked trimer of 31.4-kDa subunits, and STL2 was noncovalently linked trimer of 21.5-kDa subunits. The minimum concentrations of STL1, a major component, and STL2, a minor component, needed to agglutinate rabbit erythrocytes were 9 and 0.2 microg/ml, respectively. The most effective saccharide in the hemagglutination inhibition assay for both STL1 and STL2 was L-rhamnose. Saccharides possessing the same configuration of hydroxyl groups at C2 and C4 as that in L-rhamnose, such as L-arabinose and D-galactose, also inhibited. The amino acid sequence of STL2 was determined by analysis of peptides generated by digestion of the S-carboxamidomethylated protein with Achromobacter protease I or Staphylococcus aureus V8 protease. The STL2 subunit of 195 amino acid residues proved to have a unique polypeptide architecture; that is, it was composed of two tandemly repeated homologous domains (STL2-N and STL2-C) with 52% internal homology. These two domains showed a sequence homology to the subunit (105 amino acid residues) of D-galactoside-specific sea urchin (Anthocidaris crassispina) egg lectin (37% for STL2-N and 46% for STL2-C, respectively). The N terminus of the STL1 subunit was blocked with an acetyl group. However, a partial amino acid sequence of the subunit showed a sequence similarity to STL2. Moreover, STL2 also showed a sequence homology to the ligand binding domain of the vitellogenin receptor. We have also employed surface plasmon resonance biosensor

Expression of lectin-like oxidized LDL receptor-1 in smooth muscle cells after vascular injury

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

Eto, Hideyuki; Miyata, Masaaki; Kume, Noriaki

Lectin-like oxidized LDL receptor-1 (LOX-1) is an oxidized LDL receptor, and its role in restenosis after angioplasty remains unknown. We used a balloon-injury model of rabbit aorta, and reverse transcription-polymerase chain reaction revealed that LOX-1 mRNA expression was modest in the non-injured aorta, reached a peak level 2 days after injury, and remained elevated until 24 weeks after injury. Immunohistochemistry and in situ hybridization showed that LOX-1 was not detected in the media of non-injured aorta but expressed in both medial and neointimal smooth muscle cells (SMC) at 2 and 24 weeks after injury. Low concentrations of ox-LDL (10 {mu}g/mL)more » stimulated the cultured SMC proliferation, which was inhibited by antisense oligonucleotides of LOX-1 mRNA. Double immunofluorescense staining showed the colocalization of LOX-1 and proliferating cell nuclear antigen in human restenotic lesion. These results suggest that LOX-1 mediates ox-LDL-induced SMC proliferation and plays a role in neointimal formation after vascular injury.« less

Expression of lectin-like oxidized LDL receptor-1 in smooth muscle cells after vascular injury.

PubMed

Eto, Hideyuki; Miyata, Masaaki; Kume, Noriaki; Minami, Manabu; Itabe, Hiroyuki; Orihara, Koji; Hamasaki, Shuichi; Biro, Sadatoshi; Otsuji, Yutaka; Kita, Toru; Tei, Chuwa

2006-03-10

Lectin-like oxidized LDL receptor-1 (LOX-1) is an oxidized LDL receptor, and its role in restenosis after angioplasty remains unknown. We used a balloon-injury model of rabbit aorta, and reverse transcription-polymerase chain reaction revealed that LOX-1 mRNA expression was modest in the non-injured aorta, reached a peak level 2 days after injury, and remained elevated until 24 weeks after injury. Immunohistochemistry and in situ hybridization showed that LOX-1 was not detected in the media of non-injured aorta but expressed in both medial and neointimal smooth muscle cells (SMC) at 2 and 24 weeks after injury. Low concentrations of ox-LDL (10 microg/mL) stimulated the cultured SMC proliferation, which was inhibited by antisense oligonucleotides of LOX-1 mRNA. Double immunofluorescence staining showed the colocalization of LOX-1 and proliferating cell nuclear antigen in human restenotic lesion. These results suggest that LOX-1 mediates ox-LDL-induced SMC proliferation and plays a role in neointimal formation after vascular injury.

Astrobiology and Microbial Diversity Websites at MBL

NASA Astrophysics Data System (ADS)

Bahr, M.; Bordenstein, S. R.

2006-12-01

The NASA Astrobiology Institute (NAI) mission is to study the origin, evolution and future of life in the Universe. The MBL Astrobiology team explores the evolution and interaction of genomes of diverse organisms that play significant roles in environmental biology over evolutionary time scales. Communication about our research includes the personal contact of teacher workshops, and the development of web-based resources. Microbial Life Educational Resources (MLER) provides an expanding internet resource about the ecology, diversity and evolution for students, K-12 teachers, university faculty, and the general public. MLER includes websites, PowerPoint presentations, teaching activities, data sets, and other useful materials for creating or enhancing courses related to astrobiology. Our second site, micro*scope (http://microscope.mbl.edu), has images of microbes, classification schemes, descriptions of organisms, talks and other educational resources to improve awareness of the biodiversity of our microbial partners.

Association of Mannose-Binding Lectin rs1800450 and Tumor Necrotic Factor-α rs1800620 Polymorphism with Helicobacter pylori in Type II Diabetes Mellitus.

PubMed

Mortazavi, Elnaz; Eslami, Behnaz; Aghahosseini, Parisa; Ahron, Fatemeh; Amininejad, Armagan; Mahmoodi, Sepideh; Satarpour, Hadis; Radmanesh, Nilofar; Rassi, Hossein

2017-10-01

Type II diabetes mellitus (T2DM) is the prevalent type of diabetes, including 90% of the cases world-wide. Helicobacter pylori plays a pathogenic role in the development of T2DM. The host genetic factors have a significant impact on the clinical outcome and anatomical distribution of H. pylori infection and polymorphisms in several genes such as tumor necrotic factor (TNF)-α and mannose-binding lectin (MBL) and are considered to increase the risk for the development of T2DM. In this study, we investigate the prevalence rate of H. pylori infection and its relationship to MBL rs1800450 and TNF-α rs1800620 polymorphism in T2DM. In this case-control study, 174 patients with type II diabetes and 185 healthy controls were studied. Also, demographics, physical, and biochemical parameters were performed in all patients. The DNA extracted from blood specimens was amplified by H. pylori cagA-specific primers. The MBL rs1800450 and TNF-α rs1800620 genotyping were detected by amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). The results show that H. pylori cagA positivity was detected in 42.82% of the diabetic patients and in 22.16% of the control group, and H. pylori infection was closely correlated with MBL rs1800450 AA genotype and TNF-α rs1800620 GG genotype when compared with healthy controls. Furthermore, these two genotypes were strongly associated with H. pylori cagA(+) samples when compared with cagA(-) samples. In addition, the presence of H. pylori cagA(+) infection was significantly associated with the elevated serum levels of total cholesterol and low-density lipoprotein cholesterol. In general, it can be concluded that molecular analysis of MBL rs1800450 AA genotype and TNF-α rs1800620 AA genotype is important in the early detection and treatment of T2DM with H. pylori cagA(+) infection.

Complete structure of the cell surface polysaccharide of Streptococcus oralis ATCC 10557: A receptor for lectin-mediated interbacterial adherence

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

Abeygunawardana, C.; Bush, C.A.; Cisar, J.O.

1991-07-02

Lectin-carbohydrate binding is known to play an important role in a number of different cell-cell interactions including those between certain species of oral streptococci and actinomyces that colonize teeth. The cell wall polysaccharides of Streptococcus oralis ATCC 10557, S. oralis 34, and Streptococcus mitis J22, although not identical antigenically, each function as a receptor molecule for the galactose and N-acetylgalactosamine reactive fimbrial lectins of Actinomyces viscosus and Actinomyces naeslundii. Carbohydrate analysis of the receptor polysaccharide isolated from S. oralis ATCC 10557 shows galactose (3 mol), glucose (1 mol), GalNAc (1 mol), and rhamnose (1 mol). {sup 1}H NMR spectra ofmore » the polysaccharide show that is partially O-acetylated. Analysis of the {sup 1}H NMR spectrum of the de-O-acetylated polysaccharide shows that it is composed of repeating subunits containing six monosaccharides and that the subunits are joined by a phosphodiester linkage. The {sup 1}H and {sup 13}C NMR spectra were completely assigned by two-dimensional homonuclear correlation methods and by {sup 1}H-detected heteronuclear multiple-quantum correlation ({sup 1}H({sup 13}C)HMQC). The complete {sup 1}H and {sup 13}C assignment of the native polysaccharide was carried out by the same techniques augmented by a {sup 13}C-coupled hybrid HMQC-COSY method, which is shown to be especially useful for carbohydrates in which strong coupling and overlapping peaks in the {sup 1}H spectrum pose difficulties.« less

Survey of immune-related, mannose/fucose-binding C-type lectin receptors reveals widely divergent sugar-binding specificities

PubMed Central

Lee, Reiko T; Hsu, Tsui-Ling; Huang, Shau Ku; Hsieh, Shie-Liang; Wong, Chi-Huey; Lee, Yuan C

2011-01-01

C-type lectins (CTLs) are proteins that contain one or more carbohydrate-recognition domains (CRDs) that require calcium for sugar binding and share high degree of sequence homology and tertiary structure. CTLs whose CRD contain EPN (Glu-Pro-Asn) tripeptide motifs have potential to bind mannose (Man), N-acetylglucosamine (GlcNAc), glucose (Glc) and l-fucose (Fuc), whereas those with QPD (Glu-Pro-Asp) tripeptide motifs bind galactose (Gal) and N-acetylgalactosamine (GalNAc). We report here for the first time a direct comparison of monosaccharide (and some di- and trisaccharides)-binding characteristics of 11 EPX-containing (X = N, S or D) immune-related CTLs using a competition assay and an enzyme-linked immunosorbent assay, and neoglycoproteins as ligand. The EPX CTLs studied are DC-SIGN, L-SIGN, mSIGNR1, human and mouse mannose receptors, Langerin, BDCA-2, DCIR, dectin-2, MCL and MINCLE. We found that: (1) they all bound Man and Fuc; (2) binding of Glc and GlcNAc varied considerably among these lectins, but was always less than Man and Fuc; (3) in general, Gal and GalNAc were not bound. However, dectin-2, DCIR and MINCLE showed ability to bind Gal/GalNAc; (4) DC-SIGN, L-SIGN, mSIGNR1 and Langerin showed enhanced binding of Manα2Man over Man, whereas all others showed no enhancement; (5) DC-SIGN bound Lex trisaccharide structure, which has terminal Gal and Fuc residues, more avidly than Fuc, whereas L-SIGN, mSIGNR1, DCIR and MINCLE bound Lex less avidly than Fuc. BDCA-2, dectin-2, Langerin, MCL and mannose receptor did not bind Lex at all. PMID:21112966

Survey of immune-related, mannose/fucose-binding C-type lectin receptors reveals widely divergent sugar-binding specificities.

PubMed

Lee, Reiko T; Hsu, Tsui-Ling; Huang, Shau Ku; Hsieh, Shie-Liang; Wong, Chi-Huey; Lee, Yuan C

2011-04-01

C-type lectins (CTLs) are proteins that contain one or more carbohydrate-recognition domains (CRDs) that require calcium for sugar binding and share high degree of sequence homology and tertiary structure. CTLs whose CRD contain EPN (Glu-Pro-Asn) tripeptide motifs have potential to bind mannose (Man), N-acetylglucosamine (GlcNAc), glucose (Glc) and l-fucose (Fuc), whereas those with QPD (Glu-Pro-Asp) tripeptide motifs bind galactose (Gal) and N-acetylgalactosamine (GalNAc). We report here for the first time a direct comparison of monosaccharide (and some di- and trisaccharides)-binding characteristics of 11 EPX-containing (X = N, S or D) immune-related CTLs using a competition assay and an enzyme-linked immunosorbent assay, and neoglycoproteins as ligand. The EPX CTLs studied are DC-SIGN, L-SIGN, mSIGNR1, human and mouse mannose receptors, Langerin, BDCA-2, DCIR, dectin-2, MCL and MINCLE. We found that: (1) they all bound Man and Fuc; (2) binding of Glc and GlcNAc varied considerably among these lectins, but was always less than Man and Fuc; (3) in general, Gal and GalNAc were not bound. However, dectin-2, DCIR and MINCLE showed ability to bind Gal/GalNAc; (4) DC-SIGN, L-SIGN, mSIGNR1 and Langerin showed enhanced binding of Manα2Man over Man, whereas all others showed no enhancement; (5) DC-SIGN bound Le(x) trisaccharide structure, which has terminal Gal and Fuc residues, more avidly than Fuc, whereas L-SIGN, mSIGNR1, DCIR and MINCLE bound Le(x) less avidly than Fuc. BDCA-2, dectin-2, Langerin, MCL and mannose receptor did not bind Le(x) at all.

'Dressed for success' C-type lectin receptors for the delivery of glyco-vaccines to dendritic cells.

PubMed

Unger, Wendy W J; van Kooyk, Yvette

2011-02-01

Current strategies in immunotherapy for the treatment of tumors or autoimmunity focus on direct in vivo targeting of antigens to dendritic cells (DC), as these cells are the key regulators of immune responses. Multiple DC subsets can be distinguished in both humans and mice, based on phenotype and location. Moreover, recent data show that these subsets have distinct functions. All these features have implications for the design of DC-targeting vaccines. In this review we integrate recent knowledge on the different DC subsets in human and mice and how DC-expressed C-type lectin receptors (CLR) can be exploited for the induction of either antigen-specific immunity or tolerance. Copyright © 2010 Elsevier Ltd. All rights reserved.

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

2015-01-06

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.

Purification, characterization and biological effect of lectin from the marine sponge Stylissa flexibilis (Lévi, 1961).

PubMed

Hung, Le Dinh; Ly, Bui Minh; Hao, Vo Thi; Trung, Dinh Thanh; Trang, Vo Thi Dieu; Trinh, Phan Thi Hoai; Ngoc, Ngo Thi Duy; Quang, Thai Minh

2018-02-01

SFL, a lectin from the marine sponge Stylissa flexibilis was purified by cold ethanol precipitation followed by ion exchange chromatography on DEAE Sepharose column and Sephacryl S-200 gel filtration. SFL is a dimeric glycoprotein of 32kDa subunits linked by a disulfide bridge with a molecular mass of 64kDa by SDS-PAGE and 65kDa by Sephacryl S-200 gel filtration. SFL preferentially agglutinated enzyme treated human A erythrocytes. The activity of lectin was strongly inhibited by monosaccharide d-galactose and glycoproteins asialo-porcine stomach mucin and asialo-fetuin. The lectin was Ca 2+ dependent, stable over a range of pH from 5 to 8, and up to 60°C for 30min. The N-terminal amino acid sequence of SFL was also determined and a blast search on amino acid sequences revealed that the protein showed similarity only with lectins from the marine sponge Spheciospongia vesparia. SFL caused agglutination of Vibrio alginolyticus and V. parahaemolyticus in a dose dependent manner and inhibited the growth rates of the virulent bacterial strains. Growth inhibition of V. alginolyticus and V. parahaemolyticus with SFL was not observed in the presence of d-galactose or asialo-porcine stomach mucin, suggesting that the lectin caused the agglutination through binding to the target receptor(s) on the surface of Vibrios. Thus, the marine sponge S. flexibilis could promise to be a good source of a lectin(s) that may be useful as a carbohydrate probe and an antibacterial reagent. Copyright © 2017 Elsevier Inc. All rights reserved.

Specific interactions between lectins and red blood cells of Chornobyl cleanup workers as indicator of some late radiation effects.

PubMed

Karpova, I S

2016-12-01

Growing interest in lectins is based on their diagnostic and pharmacological potential, especially the ability to inhibit proliferation and initiate apoptosis of cancer cells. In our research microplate lectinoassay able to detect carbohydrate containing structures (receptors) on erythrocyte surface have been proposed for Chornobyl cleanup workers (1986) monitoring. It was expected to reveal specific abnormalities associated with pathological condition arising as a result of late radiation effects. Red blood cell (RBC) specimens were taken from 171 persons distributed into the six cohorts: nonexposed donors (1); chronically exposed to the doses below (2) and over 50 cGy (3); exposed to acute radiation without (4) and with manifestation of acute radiation syndrome (5 and 6). Lectins from 24 species of medicinal plants were purified by ethanol fractionation and electrofocusing. Intensity of lectin-receptor interactions was determined in reaction of hemagglutination. Method of flow cytofluorometry was used to study B-cell counts. Hormone levels in blood serum were determined by radioimmunoassay. An elevated ability of RBC to interact with the panel of lectins was found in all cohorts of exposed persons versus nonexposed donors, moreover, changes in the intensity of lectin-receptor binding depended on the dose of irradiation. Diagnostic value of specific RBC reactions with some individual lectins has been elucidated. Elevated intensity of RBC reaction with Zea mays lectin was accompanied by a decrease in serum content of thyroid hormones T4 and T3, as well as reduction of B-cell counts. In the case of Rubus caesius lectin the more intensive reaction with RBC, the higher level of hormone cortisol was observed. Deviations from donor's norm in intensity of lectin - RBC interactions in radiation exposed men are supposed to carry information about negative changes in their health status following Chornobyl catastrophe and show the diagnostic potential. The most

Precocious development of lectin (Ulex europaeus agglutinin I) receptors in dome epithelium of gut-associated lymphoid tissues.

PubMed

Roy, M J

1987-06-01

Dome epithelium (DE), the tissue covering lymphoid domes of gut-associated lymphoid tissues, was examined in both adult and neonatal rabbit appendix or sacculus rotundus to determine if dome epithelial cells matured earlier than epithelial cells covering adjacent villi. The localization of well-differentiated epithelial cells in rabbit gut-associated lymphoid tissues (GALT) was accomplished histochemically by use of molecular probes: fluorescein isothiocyanate or horseradish peroxidase conjugates of Ulex europaeus agglutinin I (UEA), a lectin specific for terminal L-fucose molecules on certain glycoconjugates. The villus epithelial cells of newborn and 2-, 5-, or 10-day-old rabbits did not bind UEA, but between the twelfth and fifteenth days of postnatal life, UEA receptors were expressed by well-differentiated villus epithelial cells. In contrast to villus epithelium, DE in appendix and sacculus rotundus of neonatal rabbits expressed UEA receptors two days after birth, a feature that distinguished the DE of neonatal GALT for the next two weeks. In adult rabbits, UEA receptors were associated with dome epithelial cells extending from the mouths of glandular crypts to the upper domes; in contrast to the domes, UEA receptors were only present on well-differentiated epithelial cells at the villus tips. Results suggested that in neonatal rabbits most dome epithelial cells developed UEA receptors shortly after birth, reflecting precocious development of DE as compared to villus epithelium. In adult rabbit dome epithelium UEA receptors appeared on dome epithelial cells as they left the glandular crypts, representing accelerated epithelial maturation.

Functional Variants in MBL2 Are Associated With Type 2 Diabetes and Pre-Diabetes Traits in Pima Indians and the Old Order Amish

PubMed Central

Muller, Yunhua L.; Hanson, Robert L.; Bian, Li; Mack, Janel; Shi, Xiaolian; Pakyz, Ruth; Shuldiner, Alan R.; Knowler, William C.; Bogardus, Clifton; Baier, Leslie J.

2010-01-01

OBJECTIVE MBL2 encodes the mannose-binding lectin, which is a key player in the innate immune system and has recently been found to play a role in insulin resistance and development of type 1 diabetes and gestational diabetes mellitus. To assess the role of MBL2 in diabetes susceptibility, this gene was analyzed in the Pima Indian population, which has a high prevalence of type 2 diabetes. RESEARCH DESIGN AND METHODS Nineteen tag single nucleotide polymorphisms (SNPs) were genotyped in a population-based sample of 3,501 full-heritage Pima Indians, and selected SNPs were further genotyped in independent samples of Native American (n = 3,723) and Old Order Amish (n = 486) subjects. RESULTS Two variants, a promoter SNP (rs11003125) at −550 bp with a risk allele frequency of 0.77 and a Gly54Asp (rs1800450) with a risk allele frequency of 0.83, were associated with type 2 diabetes in the full-heritage Pima Indians (odds ratio 1.30 per copy of the G allele for rs1103125, P = 0.0007, and 1.30 per copy of the glycine allele for rs1800450, P = 0.002, adjusted for age, sex, birth year, and family membership). These associations replicated in an independent Native American sample (1.19, P = 0.04, for rs11003125) and a Caucasian sample, the Old Order Amish (1.51, P = 0.004, for rs1103125 and 2.38, P = 0.003, for rs1800450). Among Pima Indians with normal glucose tolerance, the diabetes risk allele glycine of Gly54Asp was associated with a decreased acute insulin response to an intravenous glucose bolus infusion (P = 0.004, adjusted for age, sex, percent body fat, glucose disposal under physiological insulin stimulation, and family membership). CONCLUSIONS Our data suggest that the functional variants in MBL2 contribute to type 2 diabetes susceptibility in both Native Americans and the Old Order Amish. PMID:20522590

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

Effects of some plant lectins on hydrogen peroxide release from macrophages induced with streptococcal preparation OK-432.

PubMed Central

Tomioka, H; Saito, H

1980-01-01

Concanavalin A and phytohemagglutinin were found to cause marked inhibition of H2O2 release from macrophages induced with killed streptococci (preparation OK-432). The inhibitory effect of these two lectins on the H2O2 release from macrophages was observed with spontaneous and wheat germ lectin-triggered H2O2 release. This suggests that the lectins act directly on the macrophage H2O2-releasing function, per se, but not on the wheat germ lectin-H2O2 release-enhancing process. Concanavalin A exhibited its inhibitory action on macrophage H2O2 release by specific binding to D-mannopyranoside receptor sites on the macrophage cell surface. Galactose-binding lectins, peanut agglutinin, and soybean agglutinin failed to inhibit, but, on the other hand, slightly enhanced macrophage H2O2 release. The effect of these five lectins on the phagocytosis of latex particles by macrophages was tested. Wheat germ lectin, concanavalin A, and phytohemagglutinin significantly depressed the macrophage phagocytosis, whereas peanut agglutinin and soybean agglutinin failed to show any inhibitory action. PMID:7399666

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, Galβ1-3GalNAc. 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 Å 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.

Comparison of the antimicrobial adhesion potential of human body fluid glycoconjugates using fucose-binding lectin (PA-IIL) of Pseudomonas aeruginosa and Ulex europaeus lectin (UEA-I).

PubMed

Lerrer, Batia; Lesman-Movshovich, Efrat; Gilboa-Garber, Nechama

2005-09-01

Pseudomonas aeruginosa produces a fucose-binding lectin (PA-IIL) which strongly binds to human cells. This lectin was shown to be highly sensitive to inhibition by fucose-bearing human milk glycoproteins. Since the glycans of these glycoproteins mimic human cell receptors, they may function as decoys in blocking lectin-dependent pathogen adhesion to the host cells. Human saliva and seminal fluid also contain such compounds, and body fluids of individuals who are "secretors" express additional fucosylated (alpha 1,2) residues. The latter are selectively detected by Ulex europaeus lectin UEA-I. The aim of the present research was to compare the PA-IIL and UEA-I interactions with human salivas and seminal fluids of "secretors" and "nonsecretors" with those obtained with the respective milks. Using hemagglutination inhibition and Western blot analyses, we showed that PA-IIL interactions with the saliva and seminal fluid glycoproteins were somewhat weaker than those obtained with the milk and that "nonsecretor" body fluids were not less efficient than those of "secretors" in PA-IIL blocking. UEA-I, which interacted only with the "secretors" glycoproteins, was most sensitive to those of the seminal fluids.

A toolbox of lectins for translating the sugar code: the galectin network in phylogenesis and tumors.

PubMed

Kaltner, H; Gabius, H-J

2012-04-01

Lectin histochemistry has revealed cell-type-selective glycosylation. It is under dynamic and spatially controlled regulation. Since their chemical properties allow carbohydrates to reach unsurpassed structural diversity in oligomers, they are ideal for high density information coding. Consequently, the concept of the sugar code assigns a functional dimension to the glycans of cellular glycoconjugates. Indeed, multifarious cell processes depend on specific recognition of glycans by their receptors (lectins), which translate the sugar-encoded information into effects. Duplication of ancestral genes and the following divergence of sequences account for the evolutionary dynamics in lectin families. Differences in gene number can even appear among closely related species. The adhesion/growth-regulatory galectins are selected as an instructive example to trace the phylogenetic diversification in several animals, most of them popular models in developmental and tumor biology. Chicken galectins are identified as a low-level-complexity set, thus singled out for further detailed analysis. The various operative means for establishing protein diversity among the chicken galectins are delineated, and individual characteristics in expression profiles discerned. To apply this galectin-fingerprinting approach in histopathology has potential for refining differential diagnosis and for obtaining prognostic assessments. On the grounds of in vitro work with tumor cells a strategically orchestrated co-regulation of galectin expression with presentation of cognate glycans is detected. This coordination epitomizes the far-reaching physiological significance of sugar coding.

C-Type Lectin Receptor Dectin-2 Binds to an Endogenous Protein β-Glucuronidase on Dendritic Cells

PubMed Central

Mori, Daiki; Shibata, Kensuke; Yamasaki, Sho

2017-01-01

C-type lectin receptors (CLRs) recognize pathogen-derived ligands and abnormal self that trigger protective immune responses. However, the precise nature of self ligands recognized by CLRs remains to be determined. Here, we found that Dectin-2 recognizes bone marrow-derived dendritic cells (BMDCs) using Dectin-2-expressing reporter cells. This activity was inhibited by an excessive amount of mannose, and by the mutation of mannose-binding motif in Dectin-2. β-glucuronidase (Gusb) was identified as a protein bound to Dectin-2 and mutations of N-glycosylation sites in Gusb impaired the binding of Gusb to Dectin-2. Overexpression of Gusb in a macrophage cell line conferred an ability to stimulate Dectin-2-expressing reporter cells. Our study suggests that a glycosylated protein with mannose-related structure is recognized by Dectin-2. PMID:28046067

C-Type Lectin Receptor Dectin-2 Binds to an Endogenous Protein β-Glucuronidase on Dendritic Cells.

PubMed

Mori, Daiki; Shibata, Kensuke; Yamasaki, Sho

2017-01-01

C-type lectin receptors (CLRs) recognize pathogen-derived ligands and abnormal self that trigger protective immune responses. However, the precise nature of self ligands recognized by CLRs remains to be determined. Here, we found that Dectin-2 recognizes bone marrow-derived dendritic cells (BMDCs) using Dectin-2-expressing reporter cells. This activity was inhibited by an excessive amount of mannose, and by the mutation of mannose-binding motif in Dectin-2. β-glucuronidase (Gusb) was identified as a protein bound to Dectin-2 and mutations of N-glycosylation sites in Gusb impaired the binding of Gusb to Dectin-2. Overexpression of Gusb in a macrophage cell line conferred an ability to stimulate Dectin-2-expressing reporter cells. Our study suggests that a glycosylated protein with mannose-related structure is recognized by Dectin-2.

Determination of HIV-1 co-receptor usage.

PubMed

Cavarelli, Mariangela; Scarlatti, Gabriella

2014-01-01

Human immunodeficiency virus type I (HIV-1) infects target cells through interaction with the CD4 molecule and chemokine receptors, mainly the β-chemokine receptor 5 (CCR5) and the α-chemokine receptor 4 (CXCR4). Viral isolates can be phenotypically classified based on the co-receptor they utilize to infect target cells. In this chapter, methods to determine the co-receptor usage of HIV-1 variants are described.

Selective binding and transcytosis of Ulex europaeus 1 lectin by mouse Peyer's patch M-cells in vivo.

PubMed

Clark, M A; Jepson, M A; Simmons, N L; Hirst, B H

1995-12-01

The in vivo interaction of the lectin Ulex europaeus agglutinin 1 with mouse Peyer's patch follicle-associated epithelial cells was studied in the mouse Peyer's patch gut loop model by immunofluorescence and electron microscopy. The lectin targets to mouse Peyer's patch M-cells and is rapidly endocytosed and transcytosed. These processes are accompanied by morphological changes in the M-cell microvilli and by redistribution of polymerised actin. The demonstration of selective binding and uptake of a lectin by intestinal M-cells in vivo suggests that M-cell-specific surface glycoconjugates might act as receptors for the selective adhesion/uptake of microorganisms.

The lectin-like oxidized low-density lipoprotein receptor-1 as therapeutic target for atherosclerosis, inflammatory conditions and longevity.

PubMed

Ulrich-Merzenich, Gudrun; Zeitler, Heike

2013-08-01

The lectin-like oxidized LDL receptor-1 (LOX-1) is a scavenger receptor and is regarded as a central element in the initiation of endothelial dysfunction and its further progression to atherosclerosis. Increasing numbers of studies suggest that therapeutic strategies to modulate LOX-1 will have a broad spectrum of applications ranging from cardiovascular diseases to longevity. The dual role of LOX-1 as a culprit molecule in the process of atherosclerosis and as a danger signal in various tissues is introduced. The structure of the receptor, its ligands and its modulation by known drugs, by natural products (e.g., statins, imipramine, salicylate-based drugs, procyanidins, curcumin) and by new strategies (antisenseRNA, miRNA, pyrrole-imidazol-polyamides, LOX-1 antibodies, lipid apheresis) are described. Therapeutic approaches via transcript regulation, allowing a modulation of LOX-1, may be an easier and safer strategy than a blockade of the receptor. Considering the wide distribution of LOX-1 on different tissues, research on the mechanisms of LOX-1 modulation by drugs and natural products applying "omic"-technologies will not only allow a better understanding of the role of LOX-1 in the processes of atherosclerosis, inflammation and longevity but also support the development of specific LOX-1 modulators, avoiding the initiation of molecular mechanisms which lead to adverse events.

Fungal lectins: a growing family.

PubMed

Kobayashi, Yuka; Kawagishi, Hirokazu

2014-01-01

Fungi are members of a large group of eukaryotic organisms that include yeasts and molds, as well as the most familiar member, mushrooms. Fungal lectins with unique specificity and structures have been discovered. In general, fungal lectins are classified into specific families based on their amino acid sequences and three-dimensional structures. In this chapter, we provide an overview of the approximately 80 types of mushroom and fungal lectins that have been isolated and studied to date. In particular, we have focused on ten fungal lectins (Agaricus bisporus, Agrocybe cylindracea, Aleuria aurantia, Aspergillus oryzae, Clitocybe nebularis, Marasmius oreades, Psathyrella velutina, Rhizopus stolonifer, Pholiota squarrosa, Polyporus squamosus), many of which are commercially available and their properties, sugar-binding specificities, structural grouping into families, and applications for biological research being described. The sialic acid-specific lectins (Agrocybe cylindracea and Polyporus squamosus) and fucose-specific lectins (Aleuria aurantia, Aspergillus oryzae, Rhizopus stolonifer, and Pholiota squarrosa) each showed potential for use in identifying sialic acid glycoconjugates and fucose glycoconjugates. Although not much is currently known about fungal lectins compared to animal and plant lectins, the knowledge accumulated thus far shows great promise for several applications in the fields of taxonomy, biomedicine, and molecular and cellular biology.

The Interaction of Pneumocystis with the C-Type Lectin Receptor Mincle Exerts a Significant Role in Host Defense Against Infection

PubMed Central

Kottom, Theodore J.; Hebrink, Deanne M.; Jenson, Paige E.; Nandakumar, Vijayalakshmi; Wüthrich, Marcel; Wang, Huafeng; Klein, Bruce; Yamasaki, Sho; Lepenies, Bernd; Limper, Andrew H.

2017-01-01

Pneumocystis pneumonia (PCP) remains a major cause of morbidity and mortality within immunocompromised patients. In this study, we examined the potential role of Mincle (Macrophage inducible C-type lectin) for host defense against Pneumocystis. Binding assays implementing soluble Mincle Carbohydrate Recognition Domain (CRD) fusion proteins demonstrated binding to intact Pneumocystis carinii (Pc) as well as to organism homogenates, and purified major surface glycoprotein/glycoprotein A derived from the organism. Additional experiments showed that rats with Pneumocystis pneumonia (PCP) expressed increased Mincle mRNA levels. Mouse macrophages over-expressing Mincle displayed increased binding to Pc life forms and enhanced protein tyrosine phosphorylation. The binding of Pc to Mincle resulted in activation of Fc receptor γ (FcRγ) mediated cell signaling. RNA silencing of Mincle in mouse macrophages resulted in decreased activation of Syk kinase after Pc challenge, critical in downstream inflammatory signaling. Mincle deficient CD-4 depleted (Mincle−/−) mice showing a significant defect in organism clearance from the lungs with higher organism burdens and altered lung cytokine responses during Pneumocystis murina (Pm) pneumonia. Interestingly, Mincle−/− did not demonstrate worsened survival during PCP compared to wild type mice, despite the markedly increased organism burdens. This may be related to increased expression of anti-inflammatory factors such as IL-1Ra during infection in the Mincle−/− mice. Of note, the Pm infected Mincle−/− mice demonstrated increased expression of known C-type lectin receptors Dectin-1, Dectin-2, and MCL compared to infected wild type mice. Taken together, these data support a significant role for Mincle in Pneumocystis modulating host defense during infection. PMID:28298521

Lectins from Mycelia of Basidiomycetes

PubMed Central

Nikitina, Valentina E.; Loshchinina, Ekaterina A.; Vetchinkina, Elena P.

2017-01-01

Lectins are proteins of a nonimmunoglobulin nature that are capable of specific recognition of and reversible binding to the carbohydrate moieties of complex carbohydrates, without altering the covalent structure of any of the recognized glycosyl ligands. They have a broad range of biological activities important for the functioning of the cell and the whole organism and, owing to the high specificity of reversible binding to carbohydrates, are valuable tools used widely in biology and medicine. Lectins can be produced by many living organisms, including basidiomycetes. Whereas lectins from the fruit bodies of basidiomycetes have been studied sufficiently well, mycelial lectins remain relatively unexplored. Here, we review and comparatively analyze what is currently known about lectins isolated from the vegetative mycelium of macrobasidiomycetes, including their localization, properties, and carbohydrate specificities. Particular attention is given to the physiological role of mycelial lectins in fungal growth and development. PMID:28640205

Restricted T cell receptor repertoire in CLL-like monoclonal B cell lymphocytosis and early stage CLL.

PubMed

Blanco, Gonzalo; Vardi, Anna; Puiggros, Anna; Gómez-Llonín, Andrea; Muro, Manuel; Rodríguez-Rivera, María; Stalika, Evangelia; Abella, Eugenia; Gimeno, Eva; López-Sánchez, Manuela; Senín, Alicia; Calvo, Xavier; Abrisqueta, Pau; Bosch, Francesc; Ferrer, Ana; Stamatopoulos, Kostas; Espinet, Blanca

2018-01-01

Analysis of the T cell receptor (TR) repertoire of chronic lymphocytic leukemia-like monoclonal B cell lymphocytosis (CLL-like MBL) and early stage CLL is relevant for understanding the dynamic interaction of expanded B cell clones with bystander T cells. Here we profiled the T cell receptor β chain (TRB) repertoire of the CD4 + and CD8 + T cell fractions from 16 CLL-like MBL and 13 untreated, Binet stage A/Rai stage 0 CLL patients using subcloning analysis followed by Sanger sequencing. The T cell subpopulations of both MBL and early stage CLL harbored restricted TRB gene repertoire, with CD4 + T cell clonal expansions whose frequency followed the numerical increase of clonal B cells. Longitudinal analysis in MBL cases revealed clonal persistence, alluding to persistent antigen stimulation. In addition, the identification of shared clonotypes among different MBL/early stage CLL cases pointed towards selection of the T cell clones by common antigenic elements. T cell clonotypes previously described in viral infections and immune disorders were also detected. Altogether, our findings evidence that antigen-mediated TR restriction occurs early in clonal evolution leading to CLL and may further increase together with B cell clonal expansion, possibly suggesting that the T cell selecting antigens are tumor-related.

Binding of isolated plant lectin by rhizobia during episodes of reduced gravity obtained by parabolic flight

NASA Technical Reports Server (NTRS)

Henry, R. L.; Green, P. D.; Wong, P. P.; Guikema, J. A.; Spooner, B. S. (Principal Investigator)

1990-01-01

Development of a legume root nodule is a complex process culminating in a plant/bacterial symbiosis possessing the capacity for biological dinitrogen fixation. Formation of root nodules is initiated by the binding and stabilization of rhizobia to plant root hairs, mediated in part by a receptor/ligand recognition system composed of lectins on the plant root surface and lectin-binding sites on the rhizobial cell surface. The dinitrogen fixation activity of these root nodules may be an important feature of enclosed, space-based life support systems, and may provide an ecological method to recycle nitrogen for amino acid production. However, the effects on nodule development of varied gravitational fields, or of root nutrient delivery hardware, remain unknown. We have investigated the effects of microgravity on root nodule formation, with preliminary experiments focused upon the receptor/ligand component. Microgravity, obtained during parabolic flight aboard NASA 930, has no apparent effect on the binding of purified lectin to rhizobia, a result that will facilitate forthcoming experiments using intact root tissues.

Targeting the C-type Lectins-Mediated Host-Pathogen Interactions with Dextran

PubMed Central

Pustylnikov, Sergey; Sagar, Divya; Jain, Pooja; Khan, Zafar K.

2017-01-01

Dextran, the α-1,6-linked glucose polymer widely used in biology and medicine, promises new applications. Linear dextran applied as a blood plasma substitute demonstrates a high rate of biocompatibility. Dextran is present in foods, drugs, and vaccines and in most cases is applied as a biologically inert substance. In this review we analyze dextran’s cellular uptake principles, receptor specificity and, therefore, its ability to interfere with pathogen–lectin interactions: a promising basis for new antimicrobial strategies. Dextran-binding receptors in humans include the DC-SIGN (dendritic cell–specific intercellular adhesion molecule 3-grabbing nonintegrin) family receptors: DC-SIGN (CD209) and L-SIGN (the liver and lymphatic endothelium homologue of DC-SIGN), the mannose receptor (CD206), and langerin. These receptors take part in the uptake of pathogens by dendritic cells and macrophages and may also participate in the modulation of immune responses, mostly shown to be beneficial for pathogens per se rather than host(s). It is logical to predict that owing to receptor-specific interactions, dextran or its derivatives can interfere with these immune responses and improve infection outcome. Recent data support this hypothesis. We consider dextran a promising molecule for the development of lectin–glycan interaction-blocking molecules (such as DC-SIGN inhibitors) that could be applied in the treatment of diseases including tuberculosis, influenza, hepatitis B and C, human immunodeficiency virus infection and AIDS, etc. Dextran derivatives indeed change the pathology of infections dependent on DC-SIGN and mannose receptors. Complete knowledge of specific dextran–lectin interactions may also be important for development of future dextran applications in biological research and medicine. PMID:25224349

Lectins in human pathogenic fungi.

PubMed

Gallegos, Belém; Martínez, Ruth; Pérez, Laura; Del Socorro Pina, María; Perez, Eduardo; Hernández, Pedro

2014-01-01

Lectins are carbohydrate-binding proteins widely distributed in nature. They constitute a highly diverse group of proteins consisting of many different protein families that are, in general, structurally unrelated. In the last few years, mushroom and other fungal lectins have attracted wide attention due to their antitumour, antiproliferative and immunomodulatory activities. The present mini-review provides concise information about recent developments in understanding lectins from human pathogenic fungi. A bibliographic search was performed in the Science Direct and PubMed databases, using the following keywords "lectin", "fungi", "human" and "pathogenic". Lectins present in fungi have been classified; however, the role played by lectins derived from human pathogenic fungi in infectious processes remains uncertain; thus, this is a scientific field requiring more research. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012). Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

Lectin-Like Bacteriocins from Pseudomonas spp. Utilise D-Rhamnose Containing Lipopolysaccharide as a Cellular Receptor

PubMed Central

Josts, Inokentijs; Roszak, Aleksander W.; Waløen, Kai I.; Cogdell, Richard J.; Milner, Joel; Evans, Tom; Kelly, Sharon; Tucker, Nicholas P.; Byron, Olwyn; Smith, Brian; Walker, Daniel

2014-01-01

Lectin-like bacteriocins consist of tandem monocot mannose-binding domains and display a genus-specific killing activity. Here we show that pyocin L1, a novel member of this family from Pseudomonas aeruginosa, targets susceptible strains of this species through recognition of the common polysaccharide antigen (CPA) of P. aeruginosa lipopolysaccharide that is predominantly a homopolymer of d-rhamnose. Structural and biophysical analyses show that recognition of CPA occurs through the C-terminal carbohydrate-binding domain of pyocin L1 and that this interaction is a prerequisite for bactericidal activity. Further to this, we show that the previously described lectin-like bacteriocin putidacin L1 shows a similar carbohydrate-binding specificity, indicating that oligosaccharides containing d-rhamnose and not d-mannose, as was previously thought, are the physiologically relevant ligands for this group of bacteriocins. The widespread inclusion of d-rhamnose in the lipopolysaccharide of members of the genus Pseudomonas explains the unusual genus-specific activity of the lectin-like bacteriocins. PMID:24516380

Carbon-11 and radioiodinated derivatives of lysergic acid diethylamide: Ligands for the study of serotonin S2 receptors in vivo

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

Lever, J.R.; Hartig, P.R.; Wong, D.F.

1985-05-01

2-(/sup 125/1)-LSD binds selectively and with high affinity to serotonin S2 receptors in vitro. In the present study, the authors prepared 2-(/sup 123/1)-LSD as well as a carbon-11 labeled analog. They also characterized the in vivo binding of these tracers to receptor sites in mouse brain to assess their potential for tomographic imaging of S2 receptors in man. The temporal distribution of 2-(/sup 125/1)-LSD paralleled the density of S2 receptors. Regional selectivity was maximal after 15 minutes when tissue to cerebellum ratios were: frontal cortex (2.6), olfactory tubercles (2.4), striatum (2.3), and cortex (2.0). Preinjection of ketanserin, a potent S2more » antagonist, inhibited binding. 2-(/sup 123/1)-LSD, prepared in 20% yield from LSD and electrophilic I-123, gave similar results in vivo and may be useful for SPECT studies. The authors then synthesized N1-((/sup 11/C)-Me)-2-Br-LSD (/sup 11/C-MBL) from (/sup 11/C)-methyl iodide and 2-Br-LSD for PET imaging trials. /sup 11/C-MBL was isolated by HPLC in high chemical and radiochemical purity within 30 minutes from E.O.B. The average radiochemical yield was 20% and the specific activity was determined by U.V. spectroscopy to be up to 1300Ci/mMol (E.O.S.). 11C-MBL showed greater regional selectivity in vivo in mouse brain than 2-(/sup 125/1)-LSD. After 30 minutes, peak tissue to cerebellum ratios were: frontal cortex (5.4), olfactory tubercles (4.2), striatum (3.0), and cortex (2.8). Preinjection of ketanserin markedly inhibited /sup 11/C-MBL binding. /sup 11/C-MBL is a promising candidate for PET studies of S2 receptors.« less

Evaluation of the total MBL confirm kit (ROSCO) for detection of metallo-β-lactamases in Pseudomonas aeruginosa and Acinetobacter baumannii.

PubMed

Hansen, Frank; Hammerum, Anette M; Skov, Robert; Haldorsen, Bjørg; Sundsfjord, Arnfinn; Samuelsen, Orjan

2014-08-01

Phenotypic tests for carbapenemase production in Pseudomonas aeruginosa and Acinetobacter baumannii have been associated with unspecific metallo-β-lactamase (MBL) inhibitor activity in synergy tests and low positive predictive value. In this study, a collection of well-characterized P. aeruginosa and A. baumannii isolates was used to evaluate the inhibitor-based Total MBL Confirm Kit and the MBL Etest. Copyright © 2014 Elsevier Inc. All rights reserved.

Classification and phylogenetic analyses of the Arabidopsis and tomato G-type lectin receptor kinases.

PubMed

Teixeira, Marcella A; Rajewski, Alex; He, Jiangman; Castaneda, Olenka G; Litt, Amy; Kaloshian, Isgouhi

2018-04-06

Pathogen perception by plants is mediated by plasma membrane-localized immune receptors that have varied extracellular domains. Lectin receptor kinases (LecRKs) are among these receptors and are subdivided into 3 classes, C-type LecRKs (C-LecRKs), L-type LecRKs (L-LecRKs) and G-type LecRKs (G-LecRKs). While C-LecRKs are represented by one or two members in all plant species investigated and have unknown functions, L-LecRKs have been characterized in a few plant species and have been shown to play roles in plant defense against pathogens. Whereas Arabidopsis G-LecRKs have been characterized, this family of LecRKs has not been studied in tomato. This investigation updates the current characterization of Arabidopsis G-LecRKs and characterizes the tomato G-LecRKs, using LecRKs from the monocot rice and the basal eudicot columbine to establish a basis for comparisons between the two core eudicots. Additionally, revisiting parameters established for Arabidopsis nomenclature for LecRKs is suggested for both Arabidopsis and tomato. Moreover, using phylogenetic analysis, we show the relationship among and between members of G-LecRKs from all three eudicot plant species. Furthermore, investigating presence of motifs in G-LecRKs we identified conserved motifs among members of G-LecRKs in tomato and Arabidopsis, with five present in at least 30 of the 38 Arabidopsis members and in at least 45 of the 73 tomato members. This work characterized tomato G-LecRKs and added members to the currently characterized Arabidopsis G-LecRKs. Additionally, protein sequence analysis showed an expansion of this family in tomato as compared to Arabidopsis, and the existence of conserved common motifs in the two plant species as well as conserved species-specific motifs.

Integrating Physics and Math through Microcomputer-Based Laboratories (MBL): Effects on Discourse Type, Quality, and Mathematization

ERIC Educational Resources Information Center

BouJaoude, Saouma B.; Jurdak, Murad E.

2010-01-01

The purposes of this study were to understand the nature of discourse in terms of knowledge types and cognitive process, source of utterances (student or teacher), and time use in microcomputer-based labs (MBL) and verification type labs (VTL) and to gain an understanding of the role of MBL in promoting mathematization. The study was conducted in…

Constructively determining the MBL spectrum using Tensor Networks

NASA Astrophysics Data System (ADS)

Clark, Bryan; Yu, Xiongjie; Pekker, David

All the eigenstates of a many-body localized phase can be compactly represented in the tensor-network language. Current algorithms to find these states often only target single states and/or require difficult optimization to find. In this talk we will show how to generate every eigenstate in the spectrum constructively and discuss its implication for the properties of the MBL phase.

[Antibiotic susceptibility and occurrence of ESBL, IBL and MBL in Pseudomonas aeruginosa strains].

PubMed

Wolska, Katarzyna; Jakubczak, Antoni; Soszyńska, Agnieszka

2008-01-01

The aim of this study was to evaluate the drug susceptibility of P. aeruginosa strains and to detect strains producing inducible beta-lactamases (IBL), extended-spectrum beta-lactamases (ESBL), and metallo-beta-lactamases (MBL). During 6 month (October 2005 - March 2006), 66 strains of P. aeruginosa strains were cultured from clinical specimens obtained from patients of two of hospitals in Siedlce and from patients of outpatient clinics. All the strains were identified in the automatic ATB (bio Mérieux). The susceptibility of bacteria to antibiotics was tested by standard disc diffusion method. The majority of strains were susceptible to meropenem (89.4%), piperacillin combined with tazobactam (84.8%), ciprofloxacin (84.8%) and piperacillin (83.3%). Many of our strains were resistant to carbenicillin (69.7%), mezlocillin (45.5%), gentamicin (42.4%) and netylmicin (30.3%). 6 strains (9.1%) were multidrug-resistant (MDR). Inducible beta-lactamases were detected with the use double disc method according to Sanders and Sanders. ESBL-producing strains were detected with double disc test (DDST) according to Jarlier et al. These strains were identified as ESBL-positive on the basis of the DDST were also determined using a double disc (DD) test according to Appleton. Production of metallo-beta-lactamases (MBL) was examined with the use of Etest MBL (AB Biodisk, Sweden) and the double disc test according to Arakava et al. Sixty-five IBL-producing strains (98.5% of all strains) and three strains (4.5%) with MBL activity were detected. Strains producing extended beta-lactamases (ESBL) were not found.

BEL β-trefoil: a novel lectin with antineoplastic properties in king bolete (Boletus edulis) mushrooms.

PubMed

Bovi, Michele; Cenci, Lucia; Perduca, Massimiliano; Capaldi, Stefano; Carrizo, Maria E; Civiero, Laura; Chiarelli, Laurent R; Galliano, Monica; Monaco, Hugo L

2013-05-01

A novel lectin was purified from the fruiting bodies of king bolete mushrooms (Boletus edulis, also called porcino, cep or penny bun). The lectin was structurally characterized i.e its amino acid sequence and three-dimensional structure were determined. The new protein is a homodimer and each protomer folds as β-trefoil domain and therefore we propose the name Boletus edulis lectin (BEL) β-trefoil to distinguish it from the other lectin that has been described in these mushrooms. The lectin has potent anti-proliferative effects on human cancer cells, which confers to it an interesting therapeutic potential as an antineoplastic agent. Several crystal forms of the apoprotein and of complexes with different carbohydrates were studied by X-ray diffraction. The structure of the apoprotein was solved at 1.12 Å resolution. The interaction of the lectin with lactose, galactose, N-acetylgalactosamine and T-antigen disaccharide, Galβ1-3GalNAc, was examined in detail. All the three potential binding sites present in the β-trefoil fold are occupied in at least one crystal form and are described in detail in this paper. No important conformational changes are observed in the lectin when comparing its co-crystals with carbohydrates with those of the ligand-free protein.

A platform to screen for C-type lectin receptor-binding carbohydrates and their potential for cell-specific targeting and immune modulation.

PubMed

Maglinao, Maha; Eriksson, Magdalena; Schlegel, Mark K; Zimmermann, Stephanie; Johannssen, Timo; Götze, Sebastian; Seeberger, Peter H; Lepenies, Bernd

2014-02-10

Myeloid C-type lectin receptors (CLRs) in innate immunity represent a superfamily of pattern recognition receptors that recognize carbohydrate structures on pathogens and self-antigens. The primary interaction of an antigen-presenting cell and a pathogen shapes the following immune response. Therefore, the identification of CLR ligands that can either enhance or modulate the immune response is of interest. We have developed a screening platform based on glycan arrays to identify immune modulatory carbohydrate ligands of CLRs. A comprehensive library of CLRs was expressed by fusing the extracellular part of each respective CLR, the part containing the carbohydrate-recognition domain (CRD), to the Fc fragment of human IgG1 molecules. CLR-Fc fusion proteins display the CRD in a dimeric form, are properly glycosylated, and can be detected by a secondary antibody with a conjugated fluorophore. Thus, they are valuable tools for high-throughput screening. We were able to identify novel carbohydrate binders of CLRs using the glycan array technology. These CLR-binding carbohydrates were then covalently attached to the model antigen ovalbumin. The ovalbumin neoglycoconjugates were used in a dendritic cell/T cell co-culture assay to stimulate transgenic T cells in vitro. In addition, mice were immunized with these conjugates to analyze the immune modulatory properties of the CLR ligands in vivo. The CLR ligands induced an increased Th1 cytokine production in vitro and modulated the humoral response in vivo. The platform described here allows for the identification of CLR ligands, as well as the evaluation of each ligand's cell-specific targeting and immune modulatory properties. Copyright © 2013 Elsevier B.V. All rights reserved.

Lectin-functionalized poly(glycidyl methacrylate)-block-poly(vinyldimethyl azlactone) surface supports for high avidity microbial capture

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

Hansen, Ryan R; Hinestrosa Salazar, Juan P; Shubert, Katherine R

2013-01-01

Microbial exopolysaccharides (EPS) play a critical and dynamic role in shaping the interactions between microbial community members and their local environment. The capture of targeted microbes using surface immobilized lectins that recognize specific extracellular oligosaccharide moieties offers a non-destructive method for functional characterization based on EPS content. In this report, we evaluate the use of the block co-polymer, poly(glycidyl methacrylate)-block-4,4-dimethyl-2-vinylazlactone (PGMA-b-PVDMA), as a surface support for lectin-specific microbial capture. Arrays of circular polymer supports ten micron in diameter were generated on silicon substrates to provide discrete, covalent coupling sites for Triticum vulgare and Lens culinaris lectins. These supports promoted microbemore » adhesion and colony formation in a lectin-specific manner. Silicon posts with similar topography containing only physisorbed lectins showed significantly less activity. These results demonstrate that micropatterned PGMA-b-PVDMA supports provide a unique platform for microbial capture and screening based on EPS content by combining high avidity lectin surfaces with three-dimensional topography.« less

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

Losartan attenuated lipopolysaccharide-induced lung injury by suppression of lectin-like oxidized low-density lipoprotein receptor-1.

PubMed

Deng, Wang; Deng, Yue; Deng, Jia; Wang, Dao-Xin; Zhang, Ting

2015-01-01

Recent study has shown that renin-angiotensin system plays an important role in the development of acute lung injury (ALI) with high level of angiotensin II (AngII) generated form AngI catalyzed by angiotensin-converting enzyme. AngII plays a major effect mainly through AT1 receptor. Therefore, we speculate inhibition of AT1 receptor may possibly attenuate the lung injury. Losartan, an antagonist of AT1 receptor for angiotensin II, attenuated lung injury by alleviation of the inflammation response in ALI, but the mechanism of losartan in ALI still remains unclear. Thirty male Sprague-Dawley rats were randomly divided into Control group, ALI group (LPS), and Losartan group (LPS + Losartan). Bronchoalveolar lavage fluid (BALF) and lung tissue were obtained for analysis. The expressions of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), intercellular adhesion molecule-1 (ICAM-1) and caspase-3 were detected by reverse transcriptase polymerase chain reaction (RT-PCR) and western blotting. In ALI group, TNF-α and protein level in BALF, MPO activity in lung tissue, pulmonary edema and lung injury were significantly increased. Losartan significantly reduced LPS-induced increase in TNF-α and protein level in BALF, MPO activity, pulmonary edema and lung injury in LPS-induced lung injury. The mRNA and protein expression levels of LOX-1 were significantly decreased with the administration of losartan in LPS-induced lung injury. Also, losartan blocked the protein levels of caspase-3 and ICAM-1 mediated by LOX-1 in LPS-induced lung injury. Losartan attenuated lung injury by alleviation of the inflammation and cell apoptosis by inhibition of LOX-1 in LPS-induced lung injury.

Losartan attenuated lipopolysaccharide-induced lung injury by suppression of lectin-like oxidized low-density lipoprotein receptor-1

PubMed Central

Deng, Wang; Deng, Yue; Deng, Jia; Wang, Dao-Xin; Zhang, Ting

2015-01-01

Introduction: Recent study has shown that renin-angiotensin system plays an important role in the development of acute lung injury (ALI) with high level of angiotensin II (AngII) generated form AngI catalyzed by angiotensin-converting enzyme. AngII plays a major effect mainly through AT1 receptor. Therefore, we speculate inhibition of AT1 receptor may possibly attenuate the lung injury. Losartan, an antagonist of AT1 receptor for angiotensin II, attenuated lung injury by alleviation of the inflammation response in ALI, but the mechanism of losartan in ALI still remains unclear. Methods: Thirty male Sprague-Dawley rats were randomly divided into Control group, ALI group (LPS), and Losartan group (LPS + Losartan). Bronchoalveolar lavage fluid (BALF) and lung tissue were obtained for analysis. The expressions of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), intercellular adhesion molecule-1 (ICAM-1) and caspase-3 were detected by reverse transcriptase polymerase chain reaction (RT-PCR) and western blotting. Results: In ALI group, TNF-α and protein level in BALF, MPO activity in lung tissue, pulmonary edema and lung injury were significantly increased. Losartan significantly reduced LPS-induced increase in TNF-α and protein level in BALF, MPO activity, pulmonary edema and lung injury in LPS-induced lung injury. The mRNA and protein expression levels of LOX-1 were significantly decreased with the administration of losartan in LPS-induced lung injury. Also, losartan blocked the protein levels of caspase-3 and ICAM-1 mediated by LOX-1 in LPS-induced lung injury. Conclusions: Losartan attenuated lung injury by alleviation of the inflammation and cell apoptosis by inhibition of LOX-1 in LPS-induced lung injury. PMID:26884836

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

The MreB-like protein Mbl of Streptomyces coelicolor A3(2) depends on MreB for proper localization and contributes to spore wall synthesis.

PubMed

Heichlinger, Andrea; Ammelburg, Moritz; Kleinschnitz, Eva-Maria; Latus, Annette; Maldener, Iris; Flärdh, Klas; Wohlleben, Wolfgang; Muth, Günther

2011-04-01

Most bacteria with a rod-shaped morphology contain an actin-like cytoskeleton consisting of MreB polymers, which form helical spirals underneath the cytoplasmic membrane to direct peptidoglycan synthesis for the elongation of the cell wall. In contrast, MreB of Streptomyces coelicolor is not required for vegetative growth but has a role in sporulation. Besides MreB, S. coelicolor encodes two further MreB-like proteins, Mbl and SCO6166, whose function is unknown. Whereas MreB and Mbl are highly similar, SCO6166 is shorter, lacking the subdomains IB and IIB of actin-like proteins. Here, we showed that MreB and Mbl are not functionally redundant but cooperate in spore wall synthesis. Expression analysis by semiquantitative reverse transcription-PCR revealed distinct expression patterns. mreB and mbl are induced predominantly during morphological differentiation. In contrast, sco6166 is strongly expressed during vegetative growth but switched off during sporulation. All genes could be deleted without affecting viability. Even a ΔmreB Δmbl double mutant was viable. Δsco6166 had a wild-type phenotype. ΔmreB, Δmbl, and ΔmreB Δmbl produced swollen, prematurely germinating spores that were sensitive to various kinds of stress, suggesting a defect in spore wall integrity. During aerial mycelium formation, an Mbl-mCherry fusion protein colocalized with an MreB-enhanced green fluorescent protein (MreB-eGFP) fusion protein at the sporulation septa. Whereas MreB-eGFP localized properly in the Δmbl mutant, Mbl-mCherry localization depended on the presence of a functional MreB protein. Our results revealed that MreB and Mbl cooperate in the synthesis of the thickened spore wall, while SCO6166 has a nonessential function during vegetative growth.

FmLC5, a putative galactose-binding C-type lectin with two QPD motifs from the hemocytes of Fenneropenaeus merguiensis participates in shrimp immune defense.

PubMed

Senghoi, Wilaiwan; Runsaeng, Phanthipha; Utarabhand, Prapaporn

2017-11-01

Crustaceans are deficient in adaptive immune system. They depend completely on an innate immunity to protect themselves from invading microorganisms. One kind of pattern recognition receptors that contribute roles in the innate immunity is lectin. A new C-type lectin gene designated as FmLC5 was isolated from Fenneropenaeus merguiensis. Its full-length cDNA is composed of 1526bp and one open reading frame of 852bp encoding a peptide of 284 amino acids. The deduced amino acid sequence of FmLC5 comprises a signal peptide of 20 contiguous amino acids with a molecular mass of 31.47kDa and an isoelectric point of 4.35. The primary structure of FmLC5 consists of two similar carbohydrate recognition domains (CRDs), each CRD contains a Ca 2+ binding site-2 and a QPD motif specific for galactose-binding. The FmLC5 transcripts were detected only in the hemocytes analyzed by RT-PCR and in situ hybridization. The FmLC5 expression was significantly up-regulated after challenge with Vibrio harveyi, white spot syndrome virus (WSSV) or lipopolysaccharide. RNAi-based silencing with co-injection by V. harveyi or WSSV resulted in critical suppression of the FmLC5 expression, increasing in mortality and reduction of the median lethal time. These results conclude that FmLC5 is unique putative galactose-binding C-type lectin in F. merguiensis that may contribute as receptor molecule in the immune response to defend the shrimp from pathogenic bacteria and viruses. Copyright © 2017 Elsevier Inc. All rights reserved.

Lactose-containing starburst dendrimers: influence of dendrimer generation and binding-site orientation of receptors (plant/animal lectins and immunoglobulins) on binding properties.

PubMed

André, S; Ortega, P J; Perez, M A; Roy, R; Gabius, H J

1999-11-01

Starburst glycodendrimers offer the potential to serve as high-affinity ligands for clinically relevant sugar receptors. In order to define areas of application, their binding behavior towards sugar receptors with differential binding-site orientation but identical monosaccharide specificity must be evaluated. Using poly(amidoamine) starburst dendrimers of five generations, which contain the p-isothiocyanato derivative of p-aminophenyl-beta-D-lactoside as ligand group, four different types of galactoside-binding proteins were chosen for this purpose, i.e., the (AB)(2)-toxic agglutinin from mistletoe, a human immunoglobulin G fraction, the homodimeric galectin-1 with its two binding sites at opposite ends of the jelly-roll-motif-harboring protein and monomeric galectin-3. Direct solid-phase assays with surface-immobilized glycodendrimers resulted in obvious affinity enhancements by progressive core branching for the plant agglutinin and less pronounced for the antibody and galectin-1. High density of binding of galectin-3 with modest affinity increases only from the level of the 32-mer onwards points to favorable protein-protein interactions of the monomeric lectin and a spherical display of the end groups without a major share of backfolding. When the inhibitory potency of these probes was evaluated as competitor of receptor binding to an immobilized neoglycoprotein or to asialofetuin, a marked selectivity was detected. The 32- and 64-mers were second to none as inhibitors for the plant agglutinin against both ligand-exposing matrices and for galectin-1 on the matrix with a heterogeneous array of interglycoside distances even on the per-sugar basis. In contrast, a neoglycoprotein with the same end group was superior in the case of the antibody and, less pronounced, monomeric galectin-3. Intimate details of topological binding-site presentation and the ligand display on different generations of core assembly are major operative factors which determine the potential

A rice lectin receptor-like kinase that is involved in innate immune responses also contributes to seed germination

PubMed Central

Cheng, Xiaoyan; Wu, Yan; Guo, Jianping; Du, Bo; Chen, Rongzhi; Zhu, Lili; He, Guangcun

2013-01-01

Seed germination and innate immunity both have significant effects on plant life spans because they control the plant's entry into the ecosystem and provide defenses against various external stresses, respectively. Much ecological evidence has shown that seeds with high vigor are generally more tolerant of various environmental stimuli in the field than those with low vigor. However, there is little genetic evidence linking germination and immunity in plants. Here, we show that the rice lectin receptor-like kinase OslecRK contributes to both seed germination and plant innate immunity. We demonstrate that knocking down the OslecRK gene depresses the expression of α–amylase genes, reducing seed viability and thereby decreasing the rate of seed germination. Moreover, it also inhibits the expression of defense genes, and so reduces the resistance of rice plants to fungal and bacterial pathogens as well as herbivorous insects. Yeast two-hybrid and co-immunoprecipitation experiments revealed that OslecRK interacts with an actin-depolymerizing factor (ADF) in vivo via its kinase domain. Moreover, the rice adf mutant exhibited a reduced seed germination rate due to the suppression of α–amylase gene expression. This mutant also exhibited depressed immune responses and reduced resistance to biotic stresses. Our results thus provide direct genetic evidence for a common physiological pathway connecting germination and immunity in plants. They also partially explain the common observation that high-vigor seeds often perform well in the field. The dual effects of OslecRK may be indicative of progressive adaptive evolution in rice. PMID:24033867

Two antibacterial C-type lectins from crustacean, Eriocheir sinensis, stimulated cellular encapsulation in vitro.

PubMed

Jin, Xing-Kun; Li, Shuang; Guo, Xiao-Nv; Cheng, Lin; Wu, Min-Hao; Tan, Shang-Jian; Zhu, You-Ting; Yu, Ai-Qing; Li, Wei-Wei; Wang, Qun

2013-12-01

The first step of host fighting against pathogens is that pattern recognition receptors recognized pathogen-associated molecular patterns. However, the specificity of recognition within the innate immune molecular of invertebrates remains largely unknown. In the present study, we investigated how invertebrate pattern recognition receptor (PRR) C-type lectins might be involved in the antimicrobial response in crustacean. Based on our previously obtained completed coding regions of EsLecA and EsLecG in Eriocheir sinensis, the recombinant EsLectin proteins were produced via prokaryotic expression system and affinity chromatography. Subsequently, both rEsLecA and rEsLecG were discovered to have wide spectrum binding activities towards microorganisms, and their microbial-binding was calcium-independent. Moreover, the binding activities of both rEsLecA and rEsLecG induced the aggregation against microbial pathogens. Both microorganism growth inhibitory activities assays and antibacterial activities assays revealed their capabilities of suppressing microorganisms growth and directly killing microorganisms respectively. Furthermore, the encapsulation assays signified that both rEsLecA and rEsLecG could stimulate the cellular encapsulation in vitro. Collectively, data presented here demonstrated the successful expression and purification of two C-type lectins proteins in the Chinese mitten crab, and their critical role in the innate immune system of an invertebrate. Copyright © 2013 Elsevier Ltd. All rights reserved.

The bean. alpha. -amylase inhibitor is encoded by a lectin gene

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

Moreno, J.; Altabella, T.; Chrispeels, M.J.

The common bean, Phaseolus vulgaris, contains an inhibitor of insect and mammalian {alpha}-amylases that does not inhibit plant {alpha}-amylase. This inhibitor functions as an anti-feedant or seed-defense protein. We purified this inhibitor by affinity chromatography and found that it consists of a series of glycoforms of two polypeptides (Mr 14,000-19,000). Partial amino acid sequencing was carried out, and the sequences obtained are identical with portions of the derived amino acid sequence of a lectin-like gene. This lectin gene encodes a polypeptide of MW 28,000, and the primary in vitro translation product identified by antibodies to the {alpha}-amylase inhibitor has themore » same size. Co- and posttranslational processing of this polypeptide results in glycosylated polypeptides of 14-19 kDa. Our interpretation of these results is that the bean lectins constitute a gene family that encodes diverse plant defense proteins, including phytohemagglutinin, arcelin and {alpha}-amylase inhibitor.« less

Transmission-blocking antibodies against mosquito C-type lectins for dengue prevention.

PubMed

Liu, Yang; Zhang, Fuchun; Liu, Jianying; Xiao, Xiaoping; Zhang, Siyin; Qin, Chengfeng; Xiang, Ye; Wang, Penghua; Cheng, Gong

2014-02-01

C-type lectins are a family of proteins with carbohydrate-binding activity. Several C-type lectins in mammals or arthropods are employed as receptors or attachment factors to facilitate flavivirus invasion. We previously identified a C-type lectin in Aedes aegypti, designated as mosquito galactose specific C-type lectin-1 (mosGCTL-1), facilitating the attachment of West Nile virus (WNV) on the cell membrane. Here, we first identified that 9 A. aegypti mosGCTL genes were key susceptibility factors facilitating DENV-2 infection, of which mosGCTL-3 exhibited the most significant effect. We found that mosGCTL-3 was induced in mosquito tissues with DENV-2 infection, and that the protein interacted with DENV-2 surface envelop (E) protein and virions in vitro and in vivo. In addition, the other identified mosGCTLs interacted with the DENV-2 E protein, indicating that DENV may employ multiple mosGCTLs as ligands to promote the infection of vectors. The vectorial susceptibility factors that facilitate pathogen invasion may potentially be explored as a target to disrupt the acquisition of microbes from the vertebrate host. Indeed, membrane blood feeding of antisera against mosGCTLs dramatically reduced mosquito infective ratio. Hence, the immunization against mosGCTLs is a feasible approach for preventing dengue infection. Our study provides a future avenue for developing a transmission-blocking vaccine that interrupts the life cycle of dengue virus and reduces disease burden.

Glycodendritic structures based on Boltorn hyperbranched polymers and their interactions with Lens culinaris lectin.

PubMed

Arce, Eva; Nieto, Pedro M; Díaz, Vicente; Castro, Rossana García; Bernad, Antonio; Rojo, Javier

2003-01-01

Multivalent scaffolds bearing carbohydrates have been prepared to mediate biological processes where carbohydrates are involved. These systems consist of dendritic structures based on Boltorn H20 and H30 hyperbranched polymers to which carbohydrates are linked through a convenient spacer. Mannose has been chosen as a sugar unit to test the viability of this strategy. These glycodendritic compounds have been prepared in a few steps with good yields, showing a high solubility in physiological media and low toxicity. The binding of these dendritic polymers to the mannose-binding lectin Lens culinaris (LCA) was studied using STD-NMR experiments and quantitative precipitation assays. The results demonstrate the existence of a clear interaction between the mannose derivative systems and the Lens lectin where the dendritic scaffold does not have an important role in mannose binding but supplies the necessary multivalence for lectin cluster formation. These glycodendritic structures are able to interact with a receptor, and therefore they can be considered as promising tools for biological studies.

The MreB-Like Protein Mbl of Streptomyces coelicolor A3(2) Depends on MreB for Proper Localization and Contributes to Spore Wall Synthesis▿ †

PubMed Central

Heichlinger, Andrea; Ammelburg, Moritz; Kleinschnitz, Eva-Maria; Latus, Annette; Maldener, Iris; Flärdh, Klas; Wohlleben, Wolfgang; Muth, Günther

2011-01-01

Most bacteria with a rod-shaped morphology contain an actin-like cytoskeleton consisting of MreB polymers, which form helical spirals underneath the cytoplasmic membrane to direct peptidoglycan synthesis for the elongation of the cell wall. In contrast, MreB of Streptomyces coelicolor is not required for vegetative growth but has a role in sporulation. Besides MreB, S. coelicolor encodes two further MreB-like proteins, Mbl and SCO6166, whose function is unknown. Whereas MreB and Mbl are highly similar, SCO6166 is shorter, lacking the subdomains IB and IIB of actin-like proteins. Here, we showed that MreB and Mbl are not functionally redundant but cooperate in spore wall synthesis. Expression analysis by semiquantitative reverse transcription-PCR revealed distinct expression patterns. mreB and mbl are induced predominantly during morphological differentiation. In contrast, sco6166 is strongly expressed during vegetative growth but switched off during sporulation. All genes could be deleted without affecting viability. Even a ΔmreB Δmbl double mutant was viable. Δsco6166 had a wild-type phenotype. ΔmreB, Δmbl, and ΔmreB Δmbl produced swollen, prematurely germinating spores that were sensitive to various kinds of stress, suggesting a defect in spore wall integrity. During aerial mycelium formation, an Mbl-mCherry fusion protein colocalized with an MreB-enhanced green fluorescent protein (MreB-eGFP) fusion protein at the sporulation septa. Whereas MreB-eGFP localized properly in the Δmbl mutant, Mbl-mCherry localization depended on the presence of a functional MreB protein. Our results revealed that MreB and Mbl cooperate in the synthesis of the thickened spore wall, while SCO6166 has a nonessential function during vegetative growth. PMID:21257777

Expression patterns of lectin-like natural killer receptors, inhibitory CD94/NKG2A, and activating CD94/NKG2C on decidual CD56bright natural killer cells differ from those on peripheral CD56dim natural killer cells.

PubMed

Kusumi, Maki; Yamashita, Takahiro; Fujii, Tomoyuki; Nagamatsu, Takeshi; Kozuma, Shiro; Taketani, Yuji

2006-06-01

The balance of inhibitory and activating natural killer (NK) receptors on maternal decidual NK cells, most of which are CD56bright, is thought to be crucial for the proper growth of trophoblasts in placenta. A lectin-like NK receptor, CD94/NKG2, is the receptor for human leukocyte antigen (HLA)-E, which is expressed on trophoblasts. To clarify the mechanism regulating the activity of decidual NK cells during pregnancy, we investigated the expression patterns of inhibitory NK receptor, CD94/NKG2A, and activating receptor, CD94/NKG2C, on decidual NK cells in an early stage of normal pregnancy and compared them with those on peripheral NK cells, most of which are CD56dim. The rate of NKG2A-positive cells was significantly higher for decidual CD56bright NK cells than for peripheral CD56dim NK cells, but the rates of NKG2C-positive cells were comparable between the two cell types. Interestingly, peripheral CD56dim NK cells reciprocally expressed inhibitory NKG2A and activating NKG2C, but decidual CD56bright NK cells that expressed activating NKG2C simultaneously expressed inhibitory NKG2A. The co-expression of inhibitory and activating NKG2 receptors may fine-tune the immunoregulatory functions of the decidual NK cells to control the trophoblast invasion in constructing placenta.

Porifera Lectins: Diversity, Physiological Roles and Biotechnological Potential.

PubMed

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

2015-08-07

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.

Porifera Lectins: Diversity, Physiological Roles and Biotechnological Potential

PubMed Central

Gardères, 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

Characterization and antimicrobial activity of lectins from Penicillium sp.

PubMed

Singh, R S; Jain, P; Kaur, H P

2013-11-01

Ten Penicillium sp. were screened for lectin activity for occurrence of lectins. Mycelial extracts from submerged cultures of P. corylophilum, P. expansum and P. purpurogenum showed agglutination against human (A, B, AB and O), goat, sheep, pig and rabbit erythrocytes. Neuraminidase treatment to human blood- type O erythrocytes substantially increased their agglutinability by all the lectins as compared to untreated erythrocytes. Modification of erythrocyte surfaces by protease increased the lectin titre only of P. corylophilum with no effect on other two lectins. P. corylophilum and P. expansum displayed relatively lower titres in mycelial extracts prepared from agar plate cultures as compared to broth cultures. A panel of sugars was tested for inhibition of lectin activity. All the lectins were found to be specific for asialofetuin, bovine submaxillary mucin, porcine stomach mucin, chondroitin-6-sulphate, D-sucrose and D-glucose. P. corylophilum lectin was expressed (Titre 8) by 5 day old cultures, reaching its maximum level (Titre 32) upon 8 days of cultivation, thereafter declin in lectin activity was observed. P. purpurogenum lectin was expressed by 7-10 days old cultures, while in P. expansum maximum lectin activity was elaborated by 5-8 days old cultures. Lectin extracts from all the three species were found to possess antimicrobial activities. Lectin extracts from the three Penicillium species displayed antifungal activity and antibacterial activity against Gram-negative and Gram-positive bacterial strains.

Population-based epidemiological study of infections caused by carbapenem-resistant Pseudomonas aeruginosa in the Calgary Health Region: importance of metallo-beta-lactamase (MBL)-producing strains.

PubMed

Laupland, Kevin B; Parkins, Michael D; Church, Deirdre L; Gregson, Daniel B; Louie, Thomas J; Conly, John M; Elsayed, Sameer; Pitout, Johann D D

2005-11-01

A study was conducted in the Calgary Health Region between May 2002 and April 2004 to define the population-based epidemiological characteristics of infections caused by imipenem-resistant Pseudomonas aeruginosa and to explore the clinical outcomes due to metallo- beta -lactamase (MBL)-producing and non-MBL-producing strains. Detailed clinical information was obtained by chart review, and phenotypic and molecular characterizations were performed using the MBL E-test, polymerase chain reaction with sequencing, and pulsed-field gel electrophoresis. A total of 228 patients with infections caused by imipenem-resistant P. aeruginosa were identified (annual incidence, 10.5 cases/100,000 population), with the highest incidence rate in those >or=75 years old. MBL-producing strains (98/228) were associated with higher rates of multidrug resistance and bacteremia. Ninety MBL-producing strains also produced VIM-2, 4 produced IMP-7, and 4 were unclassified. A cluster of VIM-2-producing strains was responsible for a nosocomial outbreak during 2003. The case-fatality rate was significantly higher for infections caused by MBL-producing strains than for those caused by non-MBL-producing strains (25% vs. 13%; relative risk, 1.98 [95% confidence interval, 1.00-3.90]; P=.05). MBL-producing P. aeruginosa strains were associated with a higher case-fatality rate and invasive disease. Our study highlights the potential importance of molecular laboratory techniques in infection control and patient care.

Large Capacitance Measurement by Multiple Uses of MBL Charge Sensor

ERIC Educational Resources Information Center

Lee, Jung Sook; Chae, Min; Kim, Jung Bog

2010-01-01

A recent article by Morse described interesting electrostatics experiments using an MBL charge sensor. In this application, the charge sensor has a large capacitance compared to the charged test object, so nearly all charges can be transferred to the sensor capacitor from the capacitor to be measured. However, the typical capacitance of commercial…

ESBL, MBL and Ampc β Lactamases Producing Superbugs – Havoc in the Intensive Care Units of Punjab India

PubMed Central

Oberoi, Loveena; Singh, Nachhatarjit; Sharma, Poonam; Aggarwal, Aruna

2013-01-01

Background: An alarming rise in the rates of the antibiotic resistance has now become a serious and an increasingly common public health concern, with severe implications, especially in the intensive care units. A variety of β-lactamases which include ESBLs, AmpC β-lactamases and metallo-βlactamases, have emerged as the most worrisome mechanism of resistance among the gram negative bacteria, which pose a therapeutic challenge to the health care settings. Materials and Methods: The present study was aimed at knowing the prevalence of various β-lactamases in the gram negative isolates which were obtained from ICU patients. A total 273 gram negative isolates from 913 clinical samples which were received over a period of one year were processed for their identification and their antimicrobial susceptibility pattern was determined. They were then screened for the β-lactamase production. Results: Among the 273 isolates, the β-lactamase production was observed in 193 strains. 96 (35.16%) strains were ESBL producers, followed by 30 (10.98%) metallo β- lactamase (MBL) producers and 15(5.4%) AmpC producers. The major ESBL and AmpC producer was Escherichia coli, while Klebsiella pneumonia was the predominant MBL producer. The co production of the ESBL/MBL/ AmpC β- lactamases was observed in 52 (19.04%) strains and it was more common in Escherichia coli. A multidrug resistance to the fluoroquinolones and the aminoglycosides was also observed in the β- lactamase producing organisms. Conclusion: The high prevalence of the β- lactamases in the ICU isolates emphasizes the need for a continuous surveillance in the ICUs to detect the resistant strains, strict guidelines for the antibiotic therapy and the implementation of infection control measures to reduce the increasing burden of antibiotic resistance. PMID:23450498

Modulation of ionotropic glutamate receptor function by vertebrate galectins

PubMed Central

Copits, Bryan A; Vernon, Claire G; Sakai, Ryuichi; Swanson, Geoffrey T

2014-01-01

AMPA and kainate receptors are glutamate-gated ion channels whose function is known to be altered by a variety of plant oligosaccharide-binding proteins, or lectins, but the physiological relevance of this activity has been uncertain because no lectins with analogous allosteric modulatory effects have been identified in animals. We report here that members of the prototype galectin family, which are β-galactoside-binding lectins, exhibit subunit-specific allosteric modulation of desensitization of recombinant homomeric and heteromeric AMPA and kainate receptors. Galectin modulation of GluK2 kainate receptors was dependent upon complex oligosaccharide processing of N-glycosylation sites in the amino-terminal domain and downstream linker region. The sensitivity of GluA4 AMPA receptors to human galectin-1 could be enhanced by supplementation of culture media with uridine and N-acetylglucosamine (GlcNAc), precursors for the hexosamine pathway that supplies UDP-GlcNAc for synthesis of complex oligosaccharides. Neuronal kainate receptors in dorsal root ganglia were sensitive to galectin modulation, whereas AMPA receptors in cultured hippocampal neurons were insensitive, which could be a reflection of differential N-glycan processing or receptor subunit selectivity. Because glycan content of integral proteins can be modified dynamically, we postulate that physiological or pathological conditions in the CNS could arise in which galectins alter excitatory neurotransmission or neuronal excitability through their actions on AMPA or kainate receptors. PMID:24614744

Intrapulmonary receptors in the Tegu lizard: I. Sensitivity to CO2.

PubMed

Feede, M R; Kuhlmann, W D; Scheid, P

1977-02-01

Single unit vagal recordings from intrapulmonary receptors were obtained in decerebrate, paralyzed lizards both during pump ventilation and during unidirectional ventilation on the cannulated, sack-shaped lung. Two types of receptors were identified: (1) CO2-receptors, which increased their discharge frequency as intrapulmonary CO2 concentration decreased but were not sensitive to stretch of the lung. (2) Mechanoreceptors, which rapidly increased discharge frequency when the lung was stretched. These receptors' CO2 sensitivity varied. Lungs of lizards thus appeared to possess both CO2 receptors, which have functional characteristics similar to those in birds, and mechanoreceptors with properties similar to stretch receptors in mammals.

MBL, P2X7, and SLC11A1 gene polymorphisms in patients with oropharyngeal tularemia.

PubMed

Somuk, Battal Tahsin; Koc, Sema; Ates, Omer; Göktas, Göksel; Soyalic, Harun; Uysal, Ismail Onder; Gurbuzler, Levent; Sapmaz, Emrah; Sezer, Saime; Eyibilen, Ahmet

2016-11-01

A significant association was found of oropharyngeal tularemia with SLC11A1 allele polymorphism (INT4 G/C) and MBL2 C + 4T (P/Q). These results indicate C allele and Q allele might be a risk factor for the development of oropharyngeal tularemia. This study aimed to investigate the relationship of SLC11A1, MBL, and P2X 7 gene polymorphism with oropharyngeal tularemia. The study included totally 120 patients who were diagnosed with oropharyngeal tularemia. Frequencies of polymorphisms in the following genes were analyzed both in the patient and control groups in the study: SLC11A1 (5'(GT) n Allele 2/3, Int4 G/C, 3' UTR, D543N G/A), MBL (MBL2 C + 4T (P/Q), and P2X 7 (-762 C/T and 1513 A/C). Among all polymorphisms that were investigated in this study, SLC11A1 gene showed a significance in the distriburtion of polymorphism allelle frequency at the INT4 region. Frequency of C allele was 54 (28%) in patients with oropharyngeal tularemia, and 31 (13%) in the control group (p = 0.006 and OR = 1.96 (1.21-3.20)). An association was detected between MBL2 C + 4T (P/Q) gene polymorphism and oropharyngeal tularemia (p < 0.005 and OR = 0.30 (0.19-0.48)). No significant relation was found between P2X 7 (-762 C/T and 1513 A/C) gene polymorphism and oropharyngeal tularemia in this study (p > 0.05).

Legume Lectins: Proteins with Diverse Applications

PubMed Central

Lagarda-Diaz, Irlanda; Guzman-Partida, Ana Maria; Vazquez-Moreno, Luz

2017-01-01

Lectins are a diverse class of proteins distributed extensively in nature. Among these proteins; legume lectins display a variety of interesting features including antimicrobial; insecticidal and antitumor activities. Because lectins recognize and bind to specific glycoconjugates present on the surface of cells and intracellular structures; they can serve as potential target molecules for developing practical applications in the fields of food; agriculture; health and pharmaceutical research. This review presents the current knowledge of the main structural characteristics of legume lectins and the relationship of structure to the exhibited specificities; provides an overview of their particular antimicrobial; insecticidal and antitumor biological activities and describes possible applications based on the pattern of recognized glyco-targets. PMID:28604616

A Human Lectin Microarray for Sperm Surface Glycosylation Analysis *

PubMed Central

Sun, Yangyang; Cheng, Li; Gu, Yihua; Xin, Aijie; Wu, Bin; Zhou, Shumin; Guo, Shujuan; Liu, Yin; Diao, Hua; Shi, Huijuan; Wang, Guangyu; Tao, Sheng-ce

2016-01-01

Glycosylation is one of the most abundant and functionally important protein post-translational modifications. As such, technology for efficient glycosylation analysis is in high demand. Lectin microarrays are a powerful tool for such investigations and have been successfully applied for a variety of glycobiological studies. However, most of the current lectin microarrays are primarily constructed from plant lectins, which are not well suited for studies of human glycosylation because of the extreme complexity of human glycans. Herein, we constructed a human lectin microarray with 60 human lectin and lectin-like proteins. All of the lectins and lectin-like proteins were purified from yeast, and most showed binding to human glycans. To demonstrate the applicability of the human lectin microarray, human sperm were probed on the microarray and strong bindings were observed for several lectins, including galectin-1, 7, 8, GalNAc-T6, and ERGIC-53 (LMAN1). These bindings were validated by flow cytometry and fluorescence immunostaining. Further, mass spectrometry analysis showed that galectin-1 binds several membrane-associated proteins including heat shock protein 90. Finally, functional assays showed that binding of galectin-8 could significantly enhance the acrosome reaction within human sperms. To our knowledge, this is the first construction of a human lectin microarray, and we anticipate it will find wide use for a range of human or mammalian studies, alone or in combination with plant lectin microarrays. PMID:27364157

Changes in the Expression and Distribution of Claudins, Increased Epithelial Apoptosis, and a Mannan-Binding Lectin-Associated Immune Response Lead to Barrier Dysfunction in Dextran Sodium Sulfate-Induced Rat Colitis

PubMed Central

Yuan, Bosi; Zhou, Shuping; Lu, Youke; Liu, Jiong; Jin, Xinxin; Wan, Haijun; Wang, Fangyu

2015-01-01

Background/Aims This animal study aimed to define the underlying cellular mechanisms of intestinal barrier dysfunction. Methods Rats were fed 4% with dextran sodium sulfate (DSS) to induce experimental colitis. We analyzed the sugars in 24-hour urine output by high pressure liquid chromatography. The expression of claudins, mannan-binding lectin (MBL), and MBL-associated serine proteases 2 (MASP-2) were detected in the colonic mucosa by immunohistochemistry; and apoptotic cells in the colonic epithelium were detected by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling method assay. Results The lactulose and sucralose excretion levels in the urine of rats with DSS-induced colitis were significantly higher than those in the control rats. Mannitol excretion was lower and lactulose/mannitol ratios and sucralose/mannitol ratios were significantly increased compared with those in the control group (p<0.05). Compared with the controls, the expression of sealing claudins (claudin 3, claudin 5, and claudin 8) was significantly decreased, but that of claudin 1 was increased. The expression of pore-forming claudin 2 was upregulated and claudin 7 was downregulated in DSS-induced colitis. The epithelial apoptotic ratio was 2.8%±1.2% in controls and was significantly increased to 7.2%±1.2% in DSS-induced colitis. The expression of MBL and MASP-2 in the intestinal mucosa showed intense staining in controls, whereas there was weak staining in the rats with colitis. Conclusions There was increased intestinal permeability in DSS-induced colitis. Changes in the expression and distribution of claudins, increased epithelial apoptosis, and the MASP-2-induced immune response impaired the intestinal epithelium and contributed to high intestinal permeability. PMID:25717051

Changes in the Expression and Distribution of Claudins, Increased Epithelial Apoptosis, and a Mannan-Binding Lectin-Associated Immune Response Lead to Barrier Dysfunction in Dextran Sodium Sulfate-Induced Rat Colitis.

PubMed

Yuan, Bosi; Zhou, Shuping; Lu, Youke; Liu, Jiong; Jin, Xinxin; Wan, Haijun; Wang, Fangyu

2015-11-23

This animal study aimed to define the underlying cellular mechanisms of intestinal barrier dysfunction. Rats were fed 4% with dextran sodium sulfate (DSS) to induce experimental colitis. We analyzed the sugars in 24-hour urine output by high pressure liquid chromatography. The expression of claudins, mannan-binding lectin (MBL), and MBL-associated serine proteases 2 (MASP-2) were detected in the colonic mucosa by immunohistochemistry; and apoptotic cells in the colonic epithelium were detected by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling method assay. The lactulose and sucralose excretion levels in the urine of rats with DSS-induced colitis were significantly higher than those in the control rats. Mannitol excretion was lower and lactulose/mannitol ratios and sucralose/mannitol ratios were significantly increased compared with those in the control group (p<0.05). Compared with the controls, the expression of sealing claudins (claudin 3, claudin 5, and claudin 8) was significantly decreased, but that of claudin 1 was increased. The expression of pore-forming claudin 2 was upregulated and claudin 7 was downregulated in DSS-induced colitis. The epithelial apoptotic ratio was 2.8%±1.2% in controls and was significantly increased to 7.2%±1.2% in DSS-induced colitis. The expression of MBL and MASP-2 in the intestinal mucosa showed intense staining in controls, whereas there was weak staining in the rats with colitis. There was increased intestinal permeability in DSS-induced colitis. Changes in the expression and distribution of claudins, increased epithelial apoptosis, and the MASP-2-induced immune response impaired the intestinal epithelium and contributed to high intestinal permeability.

Co-administration of delta- and mu-opioid receptor agonists promotes peripheral opioid receptor function

PubMed Central

Schramm, Cicely L.; Honda, Christopher N.

2010-01-01

Enhancement of peripheral opioid analgesia following tissue injury or inflammation in animal models is well-documented, but clinical results of peripheral opioid therapy remain inconsistent. Previous studies in the central nervous system have shown that co-administration of μ- and δ-opioid receptor agonists can enhance analgesic outcomes; however, less is known about the functional consequences of opioid receptor interactions in the periphery. The present study examines the effects of intraplantar injection of the μ- and δ-opioid receptor agonists, morphine and deltorphin, alone and in combination on behavioral tests of nociception in naïve rats and on potassium-evoked release of CGRP from sciatic nerves of naïve rats. Neither drug alone affected nociceptive behaviors or CGRP release. Two separate measures of mechanical nociceptive sensitivity remained unchanged after co-administration of the two drugs. In contrast, when deltorphin was co-injected with morphine, dose-dependent and peripherally-restricted increases in paw withdrawal latencies to radiant heat were observed. Similarly, concentration-dependent inhibition of CGRP release was observed when deltorphin and morphine were administered in sequence prior to potassium stimulation. However, no inhibition was observed when morphine was administered prior to deltorphin. All combined opioid effects were blocked by co-application of antagonists. Deltorphin exposure also enhanced the in vivo and in vitro effects of another μ-opioid receptor agonist, DAMGO. Together, these results suggest that under normal conditions, δ-opioid receptor agonists enhance the effect of μ-opioid receptor agonists in the periphery, and local co-administration of δ- and μ-opioid receptor agonists may improve results of peripheral opioid therapy for the treatment of pain. PMID:20970925

Lectin activity in mycelial extracts of Fusarium species.

PubMed

Bhari, Ranjeeta; Kaur, Bhawanpreet; Singh, Ram S

2016-01-01

Lectins are non-immunogenic carbohydrate-recognizing proteins that bind to glycoproteins, glycolipids, or polysaccharides with high affinity and exhibit remarkable ability to agglutinate erythrocytes and other cells. In the present study, ten Fusarium species previously not explored for lectins were screened for the presence of lectin activity. Mycelial extracts of F. fujikuroi, F. beomiformii, F. begoniae, F. nisikadoi, F. anthophilum, F. incarnatum, and F. tabacinum manifested agglutination of rabbit erythrocytes. Neuraminidase treatment of rabbit erythrocytes increased lectin titers of F. nisikadoi and F. tabacinum extracts, whereas the protease treatment resulted in a significant decline in agglutination by most of the lectins. Results of hapten inhibition studies demonstrated unique carbohydrate specificity of Fusarium lectins toward O-acetyl sialic acids. Activity of the majority of Fusarium lectins exhibited binding affinity to d-ribose, l-fucose, d-glucose, l-arabinose, d-mannitol, d-galactosamine hydrochloride, d-galacturonic acid, N-acetyl-d-galactosamine, N-acetyl-neuraminic acid, 2-deoxy-d-ribose, fetuin, asialofetuin, and bovine submaxillary mucin. Melibiose and N-glycolyl neuraminic acid did not inhibit the activity of any of the Fusarium lectins. Mycelial extracts of F. begoniae, F. nisikadoi, F. anthophilum, and F. incarnatum interacted with most of the carbohydrates tested. F. fujikuroi and F. anthophilum extracts displayed strong interaction with starch. The expression of lectin activity as a function of culture age was investigated. Most species displayed lectin activity on the 7th day of cultivation, and it varied with progressing of culture age. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Incidence of Multidrug-Resistant Pseudomonas Spp. in ICU Patients with Special Reference to ESBL, AMPC, MBL and Biofilm Production

PubMed Central

Gupta, Richa; Malik, Abida; Rizvi, Meher; Ahmed, S. Moied

2016-01-01

Background: Multidrug-resistant (MDR) Pseudomonas spp. have been reported to be the important cause of ICU infections. The appearance of ESBL, AmpC and MBL genes and their spread among bacterial pathogens is a matter of great concern. Biofilm production also attributes to antimicrobial resistance due to close cell to cell contact that permits bacteria to more effectively transfer plasmids to one another. This study aimed at determining the incidence of ESBL, AmpC, MBL and biofilm producing Pseudomonas spp. in ICU patients. Material and Methods: The clinical specimens were collected aseptically from 150 ICU patients from February 2012 to October 2013. Identification and antimicrobial susceptibility was performed according to Clinical and Laboratory Standards Institute (CLSI) guidelines. ESBLs and AmpC were detected phenotypically and genotypically. MBL was detected by modified Hodge and imipenem-EDTA double-disk synergy test. Results: Pseudomonas spp. 35(28%) were the most prevalent pathogen in ICU infections. Multidrug resistance and biofilm production was observed in 80.1% and 60.4% isolates, respectively. Prevalence of ESBL, AmpC and MBL was 22.9%, 42.8% and 14.4%, respectively. The average hospital stay was 25 days and was associated with 20% mortality. Conclusions: A regular surveillance is required to detect ESBL, AmpC and MBL producers especially in ICU patients. Carbapenems should be judiciously used to prevent their spread. The effective antibiotics, such as fluoroquinolones and piperacillin-tazobactum should be used after sensitivity testing. PMID:27013841

Modulation of ionotropic glutamate receptor function by vertebrate galectins.

PubMed

Copits, Bryan A; Vernon, Claire G; Sakai, Ryuichi; Swanson, Geoffrey T

2014-05-15

AMPA and kainate receptors are glutamate-gated ion channels whose function is known to be altered by a variety of plant oligosaccharide-binding proteins, or lectins, but the physiological relevance of this activity has been uncertain because no lectins with analogous allosteric modulatory effects have been identified in animals. We report here that members of the prototype galectin family, which are β-galactoside-binding lectins, exhibit subunit-specific allosteric modulation of desensitization of recombinant homomeric and heteromeric AMPA and kainate receptors. Galectin modulation of GluK2 kainate receptors was dependent upon complex oligosaccharide processing of N-glycosylation sites in the amino-terminal domain and downstream linker region. The sensitivity of GluA4 AMPA receptors to human galectin-1 could be enhanced by supplementation of culture media with uridine and N-acetylglucosamine (GlcNAc), precursors for the hexosamine pathway that supplies UDP-GlcNAc for synthesis of complex oligosaccharides. Neuronal kainate receptors in dorsal root ganglia were sensitive to galectin modulation, whereas AMPA receptors in cultured hippocampal neurons were insensitive, which could be a reflection of differential N-glycan processing or receptor subunit selectivity. Because glycan content of integral proteins can be modified dynamically, we postulate that physiological or pathological conditions in the CNS could arise in which galectins alter excitatory neurotransmission or neuronal excitability through their actions on AMPA or kainate receptors. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.

Surface reaction of Leishmania. III. Ulex europaeus II lectin affinity for excreted factor (EF) serotype A strains.

PubMed

Greenblatt, C L; Meline, D; Slutzky, G M; Schnur, L F; Levene, C

1984-04-01

Eukaryotic parasites, including species of Leishmania, acquire or synthesize carbohydrate moieties similar to human blood group antigens. Leishmanial strains separate into three serotypes: A, B and AB. All strains containing the A component are agglutinated by Ulex europaeus lectin. Inhibition by haptene sugar suggests that a Ulex II-like receptor is involved. Organic solvents, but not protease treatment, remove its reactivity, suggesting that the receptor is a glycolipid.

[Relation of MBL ExonI 54 and NFκB1-94ins/del ATTG Polymorphism with Fever during Neutropenia in Patients with Acute Leukaemia after Chemotherapy].

PubMed

Xu, Wen-Ning; Jiang, Zu-Jun; Li, Yong-Hua; Xiao, Hao-Wen; Gao, Yang; Pang, Yan; Ouyang, Lin; Liu, Zeng-Hui; Zhang, Le-Qing; Wang, Yang; Xiao, Yang

2015-10-01

To explore the correlation between MBL ExonI 54 and NFκB1-94ins/del ATTG polymorphism and fever during neutropenia in patients with acute leukaemia (AL) (except M3) after first chemotherapy in Chinese Han population. Blood samples obtained from 76 fever patients with AL during neutropenia episodes were detected to analyse single nucleotide polymorphism (SNP) in the MBL ExonI 54 and NFκB1-94ins/del ATTG gene, and analyse the correlation between above-mentioned 2 polymorphisms and fever during neutropenia of AL patients after chemotherapy. In 76 patients, no correlation were found between MBL ExonI 54 and NFκB1-94ins/del ATTG polymorphism and fever during neutropenia in patients with acute leukaemia after chemotherapy (P > 0.05). No significant relation were found in sex, age, underlying disease, disease status or degrees of neutropenia in febrile neutropenia between MBL ExonI 54 and NFκB1-94ins/del ATTG polymorphism (P > 0.05). However, patients with MBL ExonI 54 mutation presented longer febrile duration with a median of 5 days compared to 3 days of patients with wildtype MBL ExonI 54 genotype (P < 0.05). There is no clear correlation between MBL ExonI 54 and NFκB1-94ins/del ATTG polymorphism and fever during neutropenia in patients with acute leukaemia after chemotherapy. However, the patients with MBL ExonI 54 mutation have been observed to present a longer febrile duration.

Analysis of Ethylene Receptor Interactions by Co-immunoprecipitation Assays.

PubMed

Gao, Zhiyong; Schaller, G Eric

2017-01-01

Ethylene receptors are predominantly localized to the endoplasmic reticulum (ER) membrane, and coordinate ethylene signal output through protein-protein interactions with each other and additional signaling components. Here, we describe a co-immunoprecipitation (Co-IP) assay based on the use of the Tandem Affinity Purification (TAP) tag to examine the interactions of ethylene receptors in plant extracts. Human IgG-agarose beads are used to pull down TAP-tagged versions of the protein of interest from detergent extracts of Arabidopsis membranes, and the precipitate then is analyzed immunologically for co-purification of the ethylene receptors. This method has been successfully used to examine interactions of the receptors with each other as well as with the Raf-like kinase CTR1.

Lectin cDNA and transgenic plants derived therefrom

DOEpatents

Raikhel, Natasha V.

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.

Plant lectins as defense proteins against phytophagous insects.

PubMed

Vandenborre, Gianni; Smagghe, Guy; Van Damme, Els J M

2011-09-01

One of the most important direct defense responses in plants against the attack by phytophagous insects is the production of insecticidal peptides or proteins. One particular class of entomotoxic proteins present in many plant species is the group of carbohydrate-binding proteins or lectins. During the last decade a lot of progress was made in the study of a few lectins that are expressed in response to herbivory by phytophagous insects and the insecticidal properties of plant lectins in general. This review gives an overview of lectins with high potential for the use in pest control strategies based on their activity towards pest insects. In addition, potential target sites for lectins inside the insect and the mode of action are discussed. In addition, the effect of plant lectins on non-target organisms such as beneficial insects as well as on human/animal consumers is discussed. It can be concluded that some insecticidal lectins are useful tools that can contribute to the development of integrated pest management strategies with minimal effect(s) on non-target organisms. Copyright © 2011 Elsevier Ltd. All rights reserved.

A thermostable lectin from the rhizomes of Kaempferia parviflora.

PubMed

Konkumnerd, Wichchulada; Karnchanatat, Aphichart; Sangvanich, Polkit

2010-08-30

Kaempferia parviflora, or black galingale (Kra-Chai-Dam), belongs to the Zingiberaceae family and is used as both a food ingredient and a medicinal plant. There are diverse reports on the biological activities of compounds extracted from the plant, such as antimalarial, antifungal and an effective sexual-enhancing role, but not on the lectins. A lectin was isolated from the rhizomes of Kaempferia parviflora using affinity chromatography on Concanavalin A followed by gel filtration chromatography on Sephacryl S-100. The molecular weight of the purified lectin was about 41.7 kDa. This lectin showed haemagglutinating activity against erythrocytes from several sources, with the highest level being against those from rabbits. Moreover, the lectin was thermostable, with significant haemagglutinating activity detectable up to 75 degrees C. The results of trypsin digestion and liquid chromatography/tandem mass spectrometry analysis suggested that this protein could be a member of the lectin/endochitnase1 family. A lectin that showed thermotolerant haemagglutinating activity against erythrocytes from several sources was successfully purified from K. paviflora rhizomes. Peptide sequence analysis indicated that this lectin is similar to lectin/endochitinase 1 (Urtica dioica) or Hevein-like protein (Hevea brasiliensis). Copyright (c) 2010 Society of Chemical Industry.

Lectins of beneficial microbes: system organisation, functioning and functional superfamily.

PubMed

Lakhtin, M; Lakhtin, V; Alyoshkin, V; Afanasyev, S

2011-06-01

In this review our last results and proposals with respect to general aspects of lectin studies are summarised and compared. System presence, organisation and functioning of lectins are proposed, and accents on beneficial symbiotic microbial lectins studies are presented. The proposed general principles of lectin functioning allows for a comparison of lectins with other carbohydrate-recognition systems. A new structure-functional superfamily of symbiotic microbial lectins is proposed and its main properties are described. The proposed superfamily allows for extended searches of the biological activities of any microbial member. Prospects of lectins of beneficial symbiotic microorganisms are discussed.

Antiviral Lectins: Selective Inhibitors of Viral Entry

PubMed Central

Mitchell, Carter A.; Ramessar, Koreen; O’Keefe, Barry R.

2017-01-01

Many natural lectins have been reported to have antiviral activity. As some of these have been put forward as potential development candidates for preventing or treating viral infections, we have set out in this review to survey the literature on antiviral lectins. The review groups lectins by structural class and class of source organism we also detail their carbohydrate specificity and their reported antiviral activities. The review concludes with a brief discussion of several of the pertinent hurdles that heterologous proteins must clear to be useful clinical candidates and cites examples where such studies have been reported for antiviral lectins. Though the clearest path currently being followed is the use of antiviral lectins as anti-HIV microbicides via topical mucosal administration, some investigators have also found systemic efficacy against acute infections following subcutaneous administration. PMID:28322922

Lectins for gastrointestinal targeting--15 years on.

PubMed

Woodley, J F

2000-01-01

In the mid-1980s, the concept of bioadhesion using synthetic polymers emerged, and brought with it the promise of improved efficiency for the delivery of drugs via mucosal surfaces. Studies in the author's laboratory concentrated on 'biological' bioadhesion using the naturally-occurring proteins, lectins, which recognise and bind sugars in glycoconjugates, such as those found on the surfaces of cells. Tomato Lectin (TL) was extensively studied as a putative non-toxic lectin with potential for drug targeting/delivery to the gastrointestinal (GI) tract. In vitro, the TL displayed impressive binding to the intestinal mucosa, but in vivo failed to significantly modify intestinal transit. A number of research groups have coupled the TL to microparticles, and significant systemic uptake of these has been observed in animal studies. Polymers with pendant sugars have also been shown to be bioadhesive, by interacting with endogenous lectins present on the cells of the GI tract. The use of lectins to target to Peyer's patches and diseased tissues in the colon is an interesting development, but much work remains to be done. Lectins also have potential in mucosal vaccines. Before advanced drug delivery systems using lectins can be realised, rigorous evaluation of their toxicity and immunogenicity will be required, but they clearly offer a number of possibilities for GI drug targeting systems in the future.

Complement activation by ligand-driven juxtaposition of discrete pattern recognition complexes

PubMed Central

Degn, Søren E.; Kjaer, Troels R.; Kidmose, Rune T.; Jensen, Lisbeth; Hansen, Annette G.; Tekin, Mustafa; Jensenius, Jens C.; Andersen, Gregers R.; Thiel, Steffen

2014-01-01

Defining mechanisms governing translation of molecular binding events into immune activation is central to understanding immune function. In the lectin pathway of complement, the pattern recognition molecules (PRMs) mannan-binding lectin (MBL) and ficolins complexed with the MBL-associated serine proteases (MASP)-1 and MASP-2 cleave C4 and C2 to generate C3 convertase. MASP-1 was recently found to be the exclusive activator of MASP-2 under physiological conditions, yet the predominant oligomeric forms of MBL carry only a single MASP homodimer. This prompted us to investigate whether activation of MASP-2 by MASP-1 occurs through PRM-driven juxtaposition on ligand surfaces. We demonstrate that intercomplex activation occurs between discrete PRM/MASP complexes. PRM ligand binding does not directly escort the transition of MASP from zymogen to active enzyme in the PRM/MASP complex; rather, clustering of PRM/MASP complexes directly causes activation. Our results support a clustering-based mechanism of activation, fundamentally different from the conformational model suggested for the classical pathway of complement. PMID:25197071

Lectin-Like Oxidized LDL Receptor-1 Is an Enhancer of Tumor Angiogenesis in Human Prostate Cancer Cells

PubMed Central

González-Chavarría, Iván; Cerro, Rita P.; Parra, Natalie P.; Sandoval, Felipe A.; Zuñiga, Felipe A.; Omazábal, Valeska A.; Lamperti, Liliana I.; Jiménez, Silvana P.; Fernandez, Edelmira A.; Gutiérrez, Nicolas A.; Rodriguez, Federico S.; Onate, Sergio A.; Sánchez, Oliberto; Vera, Juan C.; Toledo, Jorge R.

2014-01-01

Altered expression and function of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) has been associated with several diseases such as endothelial dysfunction, atherosclerosis and obesity. In these pathologies, oxLDL/LOX-1 activates signaling pathways that promote cell proliferation, cell motility and angiogenesis. Recent studies have indicated that olr1 mRNA is over-expressed in stage III and IV of human prostatic adenocarcinomas. However, the function of LOX-1 in prostate cancer angiogenesis remains to be determined. Our aim was to analyze the contribution of oxLDL and LOX-1 to tumor angiogenesis using C4-2 prostate cancer cells. We analyzed the expression of pro-angiogenic molecules and angiogenesis on prostate cancer tumor xenografts, using prostate cancer cell models with overexpression or knockdown of LOX-1 receptor. Our results demonstrate that the activation of LOX-1 using oxLDL increases cell proliferation, and the expression of the pro-angiogenic molecules VEGF, MMP-2, and MMP-9 in a dose-dependent manner. Noticeably, these effects were prevented in the C4-2 prostate cancer model when LOX-1 expression was knocked down. The angiogenic effect of LOX-1 activated with oxLDL was further demonstrated using the aortic ring assay and the xenograft model of tumor growth on chorioallantoic membrane of chicken embryos. Consequently, we propose that LOX-1 activation by oxLDL is an important event that enhances tumor angiogenesis in human prostate cancer cells. PMID:25170920

Structure and binding analysis of Polyporus squamosus lectin in complex with the Neu5Acα2-6Galβ1-4GlcNAc human-type influenza receptor

PubMed Central

Kadirvelraj, Renuka; Grant, Oliver C; Goldstein, Irwin J; Winter, Harry C; Tateno, Hiroaki; Fadda, Elisa; Woods, Robert J

2011-01-01

Glycan chains that terminate in sialic acid (Neu5Ac) are frequently the receptors targeted by pathogens for initial adhesion. Carbohydrate-binding proteins (lectins) with specificity for Neu5Ac are particularly useful in the detection and isolation of sialylated glycoconjugates, such as those associated with pathogen adhesion as well as those characteristic of several diseases including cancer. Structural studies of lectins are essential in order to understand the origin of their specificity, which is particularly important when employing such reagents as diagnostic tools. Here, we report a crystallographic and molecular dynamics (MD) analysis of a lectin from Polyporus squamosus (PSL) that is specific for glycans terminating with the sequence Neu5Acα2-6Galβ. Because of its importance as a histological reagent, the PSL structure was solved (to 1.7 Å) in complex with a trisaccharide, whose sequence (Neu5Acα2-6Galβ1-4GlcNAc) is exploited by influenza A hemagglutinin for viral adhesion to human tissue. The structural data illuminate the origin of the high specificity of PSL for the Neu5Acα2-6Gal sequence. Theoretical binding free energies derived from the MD data confirm the key interactions identified crystallographically and provide additional insight into the relative contributions from each amino acid, as well as estimates of the importance of entropic and enthalpic contributions to binding. PMID:21436237

YodL and YisK Possess Shape-Modifying Activities That Are Suppressed by Mutations in Bacillus subtilis mreB and mbl.

PubMed

Duan, Yi; Sperber, Anthony M; Herman, Jennifer K

2016-08-01

Many bacteria utilize actin-like proteins to direct peptidoglycan (PG) synthesis. MreB and MreB-like proteins are thought to act as scaffolds, guiding the localization and activity of key PG-synthesizing proteins during cell elongation. Despite their critical role in viability and cell shape maintenance, very little is known about how the activity of MreB family proteins is regulated. Using a Bacillus subtilis misexpression screen, we identified two genes, yodL and yisK, that when misexpressed lead to loss of cell width control and cell lysis. Expression analysis suggested that yodL and yisK are previously uncharacterized Spo0A-regulated genes, and consistent with these observations, a ΔyodL ΔyisK mutant exhibited reduced sporulation efficiency. Suppressors resistant to YodL's killing activity occurred primarily in mreB mutants and resulted in amino acid substitutions at the interface between MreB and the highly conserved morphogenic protein RodZ, whereas suppressors resistant to YisK occurred primarily in mbl mutants and mapped to Mbl's predicted ATP-binding pocket. YodL's shape-altering activity appears to require MreB, as a ΔmreB mutant was resistant to the effects of YodL but not YisK. Similarly, YisK appears to require Mbl, as a Δmbl mutant was resistant to the cell-widening effects of YisK but not of YodL. Collectively, our results suggest that YodL and YisK likely modulate MreB and Mbl activity, possibly during the early stages of sporulation. The peptidoglycan (PG) component of the cell envelope confers structural rigidity to bacteria and protects them from osmotic pressure. MreB and MreB-like proteins are thought to act as scaffolds for PG synthesis and are essential in bacteria exhibiting nonpolar growth. Despite the critical role of MreB-like proteins, we lack mechanistic insight into how their activities are regulated. Here, we describe the discovery of two B. subtilis proteins, YodL and YisK, which modulate MreB and Mbl activities. Our data suggest

YodL and YisK Possess Shape-Modifying Activities That Are Suppressed by Mutations in Bacillus subtilis mreB and mbl

PubMed Central

Duan, Yi; Sperber, Anthony M.

2016-01-01

ABSTRACT Many bacteria utilize actin-like proteins to direct peptidoglycan (PG) synthesis. MreB and MreB-like proteins are thought to act as scaffolds, guiding the localization and activity of key PG-synthesizing proteins during cell elongation. Despite their critical role in viability and cell shape maintenance, very little is known about how the activity of MreB family proteins is regulated. Using a Bacillus subtilis misexpression screen, we identified two genes, yodL and yisK, that when misexpressed lead to loss of cell width control and cell lysis. Expression analysis suggested that yodL and yisK are previously uncharacterized Spo0A-regulated genes, and consistent with these observations, a ΔyodL ΔyisK mutant exhibited reduced sporulation efficiency. Suppressors resistant to YodL's killing activity occurred primarily in mreB mutants and resulted in amino acid substitutions at the interface between MreB and the highly conserved morphogenic protein RodZ, whereas suppressors resistant to YisK occurred primarily in mbl mutants and mapped to Mbl's predicted ATP-binding pocket. YodL's shape-altering activity appears to require MreB, as a ΔmreB mutant was resistant to the effects of YodL but not YisK. Similarly, YisK appears to require Mbl, as a Δmbl mutant was resistant to the cell-widening effects of YisK but not of YodL. Collectively, our results suggest that YodL and YisK likely modulate MreB and Mbl activity, possibly during the early stages of sporulation. IMPORTANCE The peptidoglycan (PG) component of the cell envelope confers structural rigidity to bacteria and protects them from osmotic pressure. MreB and MreB-like proteins are thought to act as scaffolds for PG synthesis and are essential in bacteria exhibiting nonpolar growth. Despite the critical role of MreB-like proteins, we lack mechanistic insight into how their activities are regulated. Here, we describe the discovery of two B. subtilis proteins, YodL and YisK, which modulate MreB and Mbl

Computational Analysis of the Ligand Binding Site of the Extracellular ATP Receptor, DORN1

DOE PAGES

Nguyen, Cuong The; Tanaka, Kiwamu; Cao, Yangrong; ...

2016-09-01

DORN1 (also known as P2K1) is a plant receptor for extracellular ATP, which belongs to a large gene family of legume-type (L-type) lectin receptor kinases. Extracellular ATP binds to DORN1 with strong affinity through its lectin domain, and the binding triggers a variety of intracellular activities in response to biotic and abiotic stresses. However, information on the tertiary structure of the ligand binding site of DORN1is lacking, which hampers efforts to fully elucidate the mechanism of receptor action. Available data of the crystal structures from more than 50 L-type lectins enable us to perform an in silico study of molecularmore » interaction between DORN1 and ATP. In this study, we employed a computational approach to develop a tertiary structure model of the DORN1 lectin domain. A blind docking analysis demonstrated that ATP binds to a cavity made by four loops (defined as loops A B, C and D) of the DORN1 lectin domain with high affinity. In silico target docking of ATP to the DORN1 binding site predicted interaction with 12 residues, located on the four loops, via hydrogen bonds and hydrophobic interactions. The ATP binding pocket is structurally similar in location to the carbohydrate binding pocket of the canonical L-type lectins. However, four of the residues predicted to interact with ATP are not conserved between DORN1 and the other carbohydrate-binding lectins, suggesting that diversifying selection acting on these key residues may have led to the ATP binding activity of DORN1. Finally, the in silico model was validated by in vitro ATP binding assays using the purified extracellular lectin domain of wild-type DORN1, as well as mutated DORN1 lacking key ATP binding residues.« less

Computational Analysis of the Ligand Binding Site of the Extracellular ATP Receptor, DORN1

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

Nguyen, Cuong The; Tanaka, Kiwamu; Cao, Yangrong

DORN1 (also known as P2K1) is a plant receptor for extracellular ATP, which belongs to a large gene family of legume-type (L-type) lectin receptor kinases. Extracellular ATP binds to DORN1 with strong affinity through its lectin domain, and the binding triggers a variety of intracellular activities in response to biotic and abiotic stresses. However, information on the tertiary structure of the ligand binding site of DORN1is lacking, which hampers efforts to fully elucidate the mechanism of receptor action. Available data of the crystal structures from more than 50 L-type lectins enable us to perform an in silico study of molecularmore » interaction between DORN1 and ATP. In this study, we employed a computational approach to develop a tertiary structure model of the DORN1 lectin domain. A blind docking analysis demonstrated that ATP binds to a cavity made by four loops (defined as loops A B, C and D) of the DORN1 lectin domain with high affinity. In silico target docking of ATP to the DORN1 binding site predicted interaction with 12 residues, located on the four loops, via hydrogen bonds and hydrophobic interactions. The ATP binding pocket is structurally similar in location to the carbohydrate binding pocket of the canonical L-type lectins. However, four of the residues predicted to interact with ATP are not conserved between DORN1 and the other carbohydrate-binding lectins, suggesting that diversifying selection acting on these key residues may have led to the ATP binding activity of DORN1. Finally, the in silico model was validated by in vitro ATP binding assays using the purified extracellular lectin domain of wild-type DORN1, as well as mutated DORN1 lacking key ATP binding residues.« less

Plasmid Profile Analysis and bla VIM Gene Detection of Metalo β-lactamase (MBL) Producing Pseudomonas aeruginosa Isolates from Clinical Samples.

PubMed

S, Jayanthi; M, Jeya

2014-06-01

Pseudomonas aeruginosa is a frequent colonizer of hospitalized patients. They are responsible for serious infections such as meningitis, urological infections, septicemia and pneumonia. Carbapenem resistance of Pseudomonas aeruginosa is currently increasingly reported which is often mediated by production of metallo-β-lactamase (MBL). Multidrug resistant Pseudomonas aeruginosa isolates may involve reduced cell wall permeability, production of chromosomal and plasmid mediated β lactamases, aminoglycosides modifying enzymes and an active multidrug efflux mechanism. This study is aimed to detect the presence and the nature of plasmids among metallo-β-lactamase producing Pseudomonas aeruginosa isolates. Also to detect the presence of bla VIM gene from these isolates. Clinical isolates of Pseudomonas aeruginosa showing the metalo-β-lactamase enzyme (MBL) production were isolated. The MBL production was confirmed by three different methods. From the MBL producing isolates plasmid extraction was done by alkaline lysis method. Plasmid positive isolates were subjected for blaVIM gene detection by PCR method. Two thousand seventy six clinical samples yielded 316 (15.22%) Pseudomonas aeruginosa isolates, out of which 141 (44.62%) were multidrug resistant. Among them 25 (17.73%) were metallo-β-lactamase enzyme producers. Plasmids were extracted from 18 out of 25 isolates tested. Five out of 18 isolates were positive for the blaVIM gene detection by the PCR amplification. The MBL producers were susceptible to polymyxin /colistin with MIC ranging from 0.5 - 2μg/ml. Molecular detection of specific genes bla VIM were positive among the carbapenem resistant isolates.

Microglial Lectins in Health and Neurological Diseases

PubMed Central

Siew, Jian Jing; Chern, Yijuang

2018-01-01

Microglia are the innate sentinels of the central nervous system (CNS) and are responsible for the homeostasis and immune defense of the CNS. Under the influence of the local environment and cell-cell interaction, microglia exhibit a multidimensional and context-dependent phenotypes that can be cytotoxic and neuroprotective. Recent studies suggest that microglia express multitudinous types of lectins, including galectins, Siglecs, mannose-binding lectins (MBLs) and other glycan binding proteins. Because most studies that examine lectins focus on the peripheral system, the functions of lectins have not been critically investigated in the CNS. In addition, the types of brain cells that contribute to the altered levels of lectins present in diseases are often unclear. In this review, we will discuss how galectins, Siglecs, selectins and MBLs contribute to the dynamic functions of microglia. The interacting ligands of these lectins are complex glycoconjugates, which consist of glycoproteins and glycolipids that are expressed on microglia or surrounding cells. The current understanding of the heterogeneity and functions of glycans in the brain is limited. Galectins are a group of pleotropic proteins that recognize both β-galactoside-containing glycans and non- β-galactoside-containing proteins. The function and regulation of galectins have been implicated in immunomodulation, neuroinflammation, apoptosis, phagocytosis and oxidative bursts. Most Siglecs are expressed at a low level on the plasma membrane and bind to sialic acid residues for immunosurveillance and cell-cell communication. Siglecs are classified based on their inhibitory and activatory downstream signaling properties. Inhibitory Siglecs negatively regulate microglia activation upon recognizing the intact sialic acid patterns and vice versa. MBLs are expressed upon infection in cytoplasm and can be secreted in order to recognize molecules containing terminal mannose as an innate immune defense machinery

T-cell receptor accessory and co-receptor molecules in channel catfish

USDA-ARS?s Scientific Manuscript database

T cell receptor (TCR) associated invariant chains CD3gamma/delta,epsilon, and zeta as well as TCR co-receptors CD8alpha and CD8beta were isolated from the channel catfish, Ictalurus punctatus, at both the gene and cDNA levels. All of catfish CD3 sequences encode for proteins that resemble their resp...

Studies on lectins. XXXII. Application of affinity electrophoresis to the study of the interaction of lectins and their derivatives with sugars.

PubMed

Horejsí, V; Tichá, M; Kocourek, J

1977-09-29

Affinity electrophoresis was used to study the sugar binding heterogeneity of lectins or their derivatives. Commercial and demetallized preparations of concanavalin A could be resolved by affinity electrophoresis into three components with different affinity to immobilized sugar. Similarly the Vicia cracca lectin obtained by affinity chromatography behaved on affinity gels as a mixture of active and inactive molecular species. Affinity electrophoresis has shown that the nonhemagglutinating acetylated lentil lectin and photo-oxidized or sulfenylated pea lectin retain their sugar binding properties; dissociation constants of saccharide complexes of these derivatives are similar to those of native lectins. The presence of specific immobilized sugar in the affinity gel improved the resolution of isolectins from Dolichos biflorus and Ricinus communis seeds.

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

Association of MBL2 Gene Polymorphism with Dental Caries in Saudi Children.

PubMed

Alyousef, Yousef M; Borgio, J Francis; AbdulAzeez, Sayed; Al-Masoud, Naif; Al-Ali, Ali A; Al-Shwaimi, Emad; Al-Ali, Amein K

2017-01-01

The high prevalence of dental caries in children worldwide is a major oral health problem which requires early intervention. Dental caries is mainly caused by the action of acids produced by bacteria in addition to many other factors. Recent genetic studies have reported that a number of genes are associated with the susceptibility to dental caries. The majority of these genes are associated with inflammation, increased susceptibility to infection, and dentine matrix formation. Using the TaqMan assay and direct DNA sequencing, the prevalence of 6 single-nucleotide polymorphisms (SNPs) in MMP9, MBL2, MMP2, and TIMP2 genes was determined in 102 children with caries and in 100 age-matched caries-free controls. Out of the 6 SNPs tested in the 4 selected genes, only rs11003125 in the MBL2 gene was shown to be associated with a high prevalence of caries in our cohort. In addition, haplotype analysis of the 6 SNPs tested revealed that certain haplotypes, namely GT of rs11003125G and rs7501477T and GT of rs7096206G and rs7501477T, were found to be associated with a high prevalence of dental caries in our cohort, while haplotype AG of rs17576A and rs7501477G was found to have a protective effect against dental caries. In conclusion, the data indicate that rs11003125 in the MBL2 gene was shown to be associated with a high prevalence of caries in our cohort, and 2 haplotypes are also involved in the increased susceptibility to dental caries. © 2016 S. Karger AG, Basel.

Spleen deposition of Cryptococcus neoformans capsular glucuronoxylomannan in rodents occurs in red pulp macrophages and not marginal zone macrophages expressing the C-type lectin SIGN-R1.

PubMed

De Jesus, Magdia; Park, Chae Gyu; Su, Ya; Goldman, David L; Steinman, Ralph M; Casadevall, Arturo

2008-03-01

The fate of microbial polysaccharides in host tissues is an important consideration because these compounds are often immune modulators. Splenic marginal zone macrophages that express the C-type lectin receptor SIGN-R1, take up neutral polysaccharides such as dextran and the capsular polysaccharide of Streptococcus pneumoniae. Given that the major component of Cryptococcus neoformans capsular polysaccharide, glucuronoxylomannan (GXM), localizes in the spleen when injected intravenously, we investigated whether GXM uptake was mediated by splenic macrophages expressing the SIGN-R1 receptor in mice. No significant differences in the amount and location of GXM deposition were detected in the spleens of mice treated with a SIGN-R1 blocking antibody when compared to controls. Similarly, a blocking antibody to Dectin-1, a co-receptor of -SIGN-R1, had no effects on GXM distribution within the spleen. Histological examination of spleens from mice and rats injected with FITC-Dextran and GXM revealed no significant co-localization, with Dextran and GXM being found in marginal and red pulp macrophages, respectively. Hence we conclude that GXM was not deposited in marginal zone macrophages. However, GXM deposition was found in the red pulp. These results indicate that there is a selective localization of these polysaccharides to different receptors such as SIGN-R1 for FITC dextran in marginal zone and a to-be-identified receptor selectively expressed by red pulp macrophages for GXM.

Identification of a new C-type lectin, TES-70, secreted by infective larvae of Toxocara canis, which binds to host ligands.

PubMed

Loukas, A; Doedens, A; Hintz, M; Maizels, R M

2000-11-01

Infective larvae of the dog roundworm Toxocara canis survive in the tissues of their hosts for extended periods in a state of developmental arrest, successfully evading immune destruction. This survival strategy is thought to be mediated by T. canis excretory/secretory (TES) products which downregulate or divert the immune response. We purified one of the major TES products, TES-70 and gained amino acid sequence from 4 tryptic peptides. These peptides were matched to a predicted protein from a cDNA that was isolated by expression screening a T. canis cDNA library with mouse anti-TES serum. The predicted protein (Tc-CTL-4) is similar to, but larger than, Tc-CTL-1, a 32-kDa C-type lectin secreted by T. canis larvae. Tc-CTL-4 has a signal peptide, 2 Cys-rich domains and a C-terminal calcium-dependent C-type lectin domain that shares sequence similarity with host immune cell receptors such as macrophage mannose receptor and CD23. The lectin domain was expressed in bacteria and antiserum to the purified recombinant protein was used to confirm that Tc-ctl-4 did encode the native TES-70 glycoprotein. TES-70 selectively bound to ligands on the surface of Madin-Darby Canine Kidney cells in vitro in a calcium-dependent manner, inhibitable by mammalian serum, indicating that a host glycan is the native ligand for this new parasite lectin.

Galectin-3 alters the lateral mobility and clustering of β1-integrin receptors

PubMed Central

Yang, Esther H.; Rode, Julia; Howlader, Md. Amran; Eckermann, Marina; Santos, Jobette T.; Hernandez Armada, Daniel; Zheng, Ruixiang; Zou, Chunxia

2017-01-01

Glycoprotein receptors are influenced by myriad intermolecular interactions at the cell surface. Specific glycan structures may interact with endogenous lectins that enforce or disrupt receptor-receptor interactions. Glycoproteins bound by multivalent lectins may form extended oligomers or lattices, altering the lateral mobility of the receptor and influencing its function through endocytosis or changes in activation. In this study, we have examined the interaction of Galectin-3 (Gal-3), a human lectin, with adhesion receptors. We measured the effect of recombinant Gal-3 added exogenously on the lateral mobility of the α5β1 integrin on HeLa cells. Using single-particle tracking (SPT) we detected increased lateral mobility of the integrin in the presence of Gal-3, while its truncated C-terminal domain (Gal-3C) showed only minor reductions in lateral mobility. Treatment of cells with Gal-3 increased β1-integrin mediated migration with no apparent changes in viability. In contrast, Gal-3C decreased both cell migration and viability. Fluorescence microscopy allowed us to confirm that exogenous Gal-3 resulted in reorganization of the integrin into larger clusters. We used a proteomics analysis to confirm that cells expressed endogenous Gal-3, and found that addition of competitive oligosaccharide ligands for the lectin altered the lateral mobility of the integrin. Together, our results are consistent with a Gal-3–integrin lattice model of binding and confirm that the lateral mobility of integrins is natively regulated, in part, by galectins. PMID:29016609

Lectins as endocytic ligands: an assessment of lectin binding and uptake to rabbit conjunctival epithelial cells.

PubMed

Qaddoumi, Mohamed; Lee, Vincent H L

2004-07-01

To investigate the binding and uptake pattern of three plant lectins in rabbit conjunctival epithelial cells (RCECs) with respect to their potential for enhancing cellular macromolecular uptake. Three fluorescein-labeled plant lectins (Lycoperison esculentum, TL; Solanum tuberosum, STL; and Ulex europaeus 1, UEA-1) were screened with respect to time-, concentration-, and temperature-dependent binding and uptake. Chitin (30 mg/ml) and L-alpha-fucose (10 mM) were used as inhibitory sugars to correct for nonspecific binding of TL or STL and UEA-1, respectively. Confocal microscopy was used to confirm internalization of STL. The binding and uptake of all three lectins in RCECs was time-dependent (reaching a plateau at 1-2 h period) and saturable at 1-h period. The rank order of affinity constants (km) was STL>TL>UEA-1 with values of 0.39>0.48>4.81 microM, respectively. However, maximal, specific binding/uptake potential was in the order UEA-1>STL>TL with values of 53.7, 52.3, and 15.0 nM/mg of cell protein, respectively. Lectins showed temperature dependence in their uptake, with STL exhibiting the highest endocytic capacity. Internalized STL was visualized by confocal microscopy to be localized to the cell membrane and cytoplasm. Based on favorable binding and uptake characteristics, potato lectin appears to be a useful candidate for further investigation as an ocular drug delivery system.

Plasmid Profile Analysis and bla VIM Gene Detection of Metalo β-lactamase (MBL) Producing Pseudomonas aeruginosa Isolates from Clinical Samples

PubMed Central

M, Jeya

2014-01-01

Introduction:Pseudomonas aeruginosa is a frequent colonizer of hospitalized patients. They are responsible for serious infections such as meningitis, urological infections, septicemia and pneumonia. Carbapenem resistance of Pseudomonas aeruginosa is currently increasingly reported which is often mediated by production of metallo-β-lactamase (MBL). Multidrug resistant Pseudomonas aeruginosa isolates may involve reduced cell wall permeability, production of chromosomal and plasmid mediated β lactamases, aminoglycosides modifying enzymes and an active multidrug efflux mechanism. Objective: This study is aimed to detect the presence and the nature of plasmids among metallo-β-lactamase producing Pseudomonas aeruginosa isolates. Also to detect the presence of bla VIM gene from these isolates. Materials and Methods: Clinical isolates of Pseudomonas aeruginosa showing the metalo-β-lactamase enzyme (MBL) production were isolated. The MBL production was confirmed by three different methods. From the MBL producing isolates plasmid extraction was done by alkaline lysis method. Plasmid positive isolates were subjected for blaVIM gene detection by PCR method. Results: Two thousand seventy six clinical samples yielded 316 (15.22%) Pseudomonas aeruginosa isolates, out of which 141 (44.62%) were multidrug resistant. Among them 25 (17.73%) were metallo-β-lactamase enzyme producers. Plasmids were extracted from 18 out of 25 isolates tested. Five out of 18 isolates were positive for the blaVIM gene detection by the PCR amplification. Conclusion: The MBL producers were susceptible to polymyxin /colistin with MIC ranging from 0.5 – 2μg/ml. Molecular detection of specific genes bla VIM were positive among the carbapenem resistant isolates. PMID:25120980

Lectindb: a plant lectin database.

PubMed

Chandra, Nagasuma R; Kumar, Nirmal; Jeyakani, Justin; Singh, Desh Deepak; Gowda, Sharan B; Prathima, M N

2006-10-01

Lectins, a class of carbohydrate-binding proteins, are now widely recognized to play a range of crucial roles in many cell-cell recognition events triggering several important cellular processes. They encompass different members that are diverse in their sequences, structures, binding site architectures, quaternary structures, carbohydrate affinities, and specificities as well as their larger biological roles and potential applications. It is not surprising, therefore, that the vast amount of experimental data on lectins available in the literature is so diverse, that it becomes difficult and time consuming, if not impossible to comprehend the advances in various areas and obtain the maximum benefit. To achieve an effective use of all the data toward understanding the function and their possible applications, an organization of these seemingly independent data into a common framework is essential. An integrated knowledge base ( Lectindb, http://nscdb.bic.physics.iisc.ernet.in ) together with appropriate analytical tools has therefore been developed initially for plant lectins by collating and integrating diverse data. The database has been implemented using MySQL on a Linux platform and web-enabled using PERL-CGI and Java tools. Data for each lectin pertain to taxonomic, biochemical, domain architecture, molecular sequence, and structural details as well as carbohydrate and hence blood group specificities. Extensive links have also been provided for relevant bioinformatics resources and analytical tools. Availability of diverse data integrated into a common framework is expected to be of high value not only for basic studies in lectin biology but also for basic studies in pursuing several applications in biotechnology, immunology, and clinical practice, using these molecules.

Immune Receptors and Co-receptors in Antiviral Innate Immunity in Plants.

PubMed

Gouveia, Bianca C; Calil, Iara P; Machado, João Paulo B; Santos, Anésia A; Fontes, Elizabeth P B

2016-01-01

Plants respond to pathogens using an innate immune system that is broadly divided into PTI (pathogen-associated molecular pattern- or PAMP-triggered immunity) and ETI (effector-triggered immunity). PTI is activated upon perception of PAMPs, conserved motifs derived from pathogens, by surface membrane-anchored pattern recognition receptors (PRRs). To overcome this first line of defense, pathogens release into plant cells effectors that inhibit PTI and activate effector-triggered susceptibility (ETS). Counteracting this virulence strategy, plant cells synthesize intracellular resistance (R) proteins, which specifically recognize pathogen effectors or avirulence (Avr) factors and activate ETI. These coevolving pathogen virulence strategies and plant resistance mechanisms illustrate evolutionary arms race between pathogen and host, which is integrated into the zigzag model of plant innate immunity. Although antiviral immune concepts have been initially excluded from the zigzag model, recent studies have provided several lines of evidence substantiating the notion that plants deploy the innate immune system to fight viruses in a manner similar to that used for non-viral pathogens. First, most R proteins against viruses so far characterized share structural similarity with antibacterial and antifungal R gene products and elicit typical ETI-based immune responses. Second, virus-derived PAMPs may activate PTI-like responses through immune co-receptors of plant PTI. Finally, and even more compelling, a viral Avr factor that triggers ETI in resistant genotypes has recently been shown to act as a suppressor of PTI, integrating plant viruses into the co-evolutionary model of host-pathogen interactions, the zigzag model. In this review, we summarize these important progresses, focusing on the potential significance of antiviral immune receptors and co-receptors in plant antiviral innate immunity. In light of the innate immune system, we also discuss a newly uncovered layer of

Structure Predictions of Two Bauhinia variegata Lectins Reveal Patterns of C-Terminal Properties in Single Chain Legume Lectins

PubMed Central

Moreira, Gustavo M. S. G.; Conceição, Fabricio R.; McBride, Alan J. A.; Pinto, Luciano da S.

2013-01-01

Bauhinia variegata lectins (BVL-I and BVL-II) are single chain lectins isolated from the plant Bauhinia variegata. Single chain lectins undergo post-translational processing on its N-terminal and C-terminal regions, which determines their physiological targeting, carbohydrate binding activity and pattern of quaternary association. These two lectins are isoforms, BVL-I being highly glycosylated, and thus far, it has not been possible to determine their structures. The present study used prediction and validation algorithms to elucidate the likely structures of BVL-I and -II. The program Bhageerath-H was chosen from among three different structure prediction programs due to its better overall reliability. In order to predict the C-terminal region cleavage sites, other lectins known to have this modification were analysed and three rules were created: (1) the first amino acid of the excised peptide is small or hydrophobic; (2) the cleavage occurs after an acid, polar, or hydrophobic residue, but not after a basic one; and (3) the cleavage spot is located 5-8 residues after a conserved Leu amino acid. These rules predicted that BVL-I and –II would have fifteen C-terminal residues cleaved, and this was confirmed experimentally by Edman degradation sequencing of BVL-I. Furthermore, the C-terminal analyses predicted that only BVL-II underwent α-helical folding in this region, similar to that seen in SBA and DBL. Conversely, BVL-I and -II contained four conserved regions of a GS-I association, providing evidence of a previously undescribed X4+unusual oligomerisation between the truncated BVL-I and the intact BVL-II. This is the first report on the structural analysis of lectins from Bauhinia spp. and therefore is important for the characterisation C-terminal cleavage and patterns of quaternary association of single chain lectins. PMID:24260572

Structure predictions of two Bauhinia variegata lectins reveal patterns of C-terminal properties in single chain legume lectins.

PubMed

Moreira, Gustavo M S G; Conceição, Fabricio R; McBride, Alan J A; Pinto, Luciano da S

2013-01-01

Bauhinia variegata lectins (BVL-I and BVL-II) are single chain lectins isolated from the plant Bauhinia variegata. Single chain lectins undergo post-translational processing on its N-terminal and C-terminal regions, which determines their physiological targeting, carbohydrate binding activity and pattern of quaternary association. These two lectins are isoforms, BVL-I being highly glycosylated, and thus far, it has not been possible to determine their structures. The present study used prediction and validation algorithms to elucidate the likely structures of BVL-I and -II. The program Bhageerath-H was chosen from among three different structure prediction programs due to its better overall reliability. In order to predict the C-terminal region cleavage sites, other lectins known to have this modification were analysed and three rules were created: (1) the first amino acid of the excised peptide is small or hydrophobic; (2) the cleavage occurs after an acid, polar, or hydrophobic residue, but not after a basic one; and (3) the cleavage spot is located 5-8 residues after a conserved Leu amino acid. These rules predicted that BVL-I and -II would have fifteen C-terminal residues cleaved, and this was confirmed experimentally by Edman degradation sequencing of BVL-I. Furthermore, the C-terminal analyses predicted that only BVL-II underwent α-helical folding in this region, similar to that seen in SBA and DBL. Conversely, BVL-I and -II contained four conserved regions of a GS-I association, providing evidence of a previously undescribed X4+unusual oligomerisation between the truncated BVL-I and the intact BVL-II. This is the first report on the structural analysis of lectins from Bauhinia spp. and therefore is important for the characterisation C-terminal cleavage and patterns of quaternary association of single chain lectins.

CD22 serves as a receptor for soluble IgM.

PubMed

Adachi, Takahiro; Harumiya, Satoru; Takematsu, Hiromu; Kozutsumi, Yasunori; Wabl, Matthias; Fujimoto, Manabu; Tedder, Thomas F

2012-01-01

CD22 (Siglec-2) is a B-cell membrane-bound lectin that recognizes glycan ligands containing α2,6-linked sialic acid (α2,6Sia) and negatively regulates signaling through the B-cell Ag receptor (BCR). Although CD22 has been investigated extensively, its precise function remains unclear due to acting multiple phases. Here, we demonstrate that CD22 is efficiently activated in trans by complexes of Ag and soluble IgM (sIgM) due to the presence of glycan ligands on sIgM. This result strongly suggests sIgM as a natural trans ligand for CD22. Also, CD22 appears to serve as a receptor for sIgM, which induces a negative feedback loop for B-cell activation similar to the Fc receptor for IgG (FcγRIIB). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lectin histochemistry and alkaline phosphatase activity in the pia mater vessels of spontaneously hypertensive rats (SHR).

PubMed

Szumańska, G; Gadamski, R

1992-01-01

Some lectins were used to study the localization of sugar residues on the endothelial cell surface in the pia mater blood vessels of control (WKY) and hypertensive rats (SHR). The lectins tested recognized the following residues: beta-D-galactosyl (Ricinus communis agglutinin 120, RCA-1), alpha-L-fucosyl (Ulex europaeus agglutinin, UEA-1), N-acetylglucosaminyl and sialyl (Wheat germ agglutinin, WGA), N-glycolyl-neuraminic acid (Limax flavus agglutinin, LFA), and N-acetyl-D-galactosaminyl (Helix pomatia agglutinin, HPA). Several differences were revealed in the presence of sugar receptors on the surface of endothelial cells between the control and the hypertensive rats. Our studies showed also differences in the localization of the tested glycoconjugates between pial capillaries, small, medium-size and large pial arteries. The histochemical evaluation of alkaline phosphatase revealed an increased activity of the enzyme in the pial vessels of SHRs as compared with control rats with a similar localization of the enzyme activity. Some differences in the distribution of lectin binding sites and alkaline phosphatase activity could be associated with the different functions of particular segments of the pial vascular network.

5-HT2A receptor activation is necessary for CO2-induced arousal

PubMed Central

Smith, Haleigh R.; MacAskill, Amanda; Richerson, George B.

2015-01-01

Hypercapnia-induced arousal from sleep is an important protective mechanism pertinent to a number of diseases. Most notably among these are the sudden infant death syndrome, obstructive sleep apnea and sudden unexpected death in epilepsy. Serotonin (5-HT) plays a significant role in hypercapnia-induced arousal. The mechanism of 5-HT's role in this protective response is unknown. Here we sought to identify the specific 5-HT receptor subtype(s) involved in this response. Wild-type mice were pretreated with antagonists against 5-HT receptor subtypes, as well as antagonists against adrenergic, cholinergic, histaminergic, dopaminergic, and orexinergic receptors before challenge with inspired CO2 or hypoxia. Antagonists of 5-HT2A receptors dose-dependently blocked CO2-induced arousal. The 5-HT2C receptor antagonist, RS-102221, and the 5-HT1A receptor agonist, 8-OH-DPAT, attenuated but did not completely block CO2-induced arousal. Blockade of non-5-HT receptors did not affect CO2-induced arousal. None of these drugs had any effect on hypoxia-induced arousal. 5-HT2 receptor agonists were given to mice in which 5-HT neurons had been genetically eliminated during embryonic life (Lmx1bf/f/p) and which are known to lack CO2-induced arousal. Application of agonists to 5-HT2A, but not 5-HT2C, receptors, dose-dependently restored CO2-induced arousal in these mice. These data identify the 5-HT2A receptor as an important mediator of CO2-induced arousal and suggest that, while 5-HT neurons can be independently activated to drive CO2-induced arousal, in the absence of 5-HT neurons and endogenous 5-HT, 5-HT receptor activation can act in a permissive fashion to facilitate CO2-induced arousal via another as yet unidentified chemosensor system. PMID:25925320

Glycoprofiling of Early Gastric Cancer Using Lectin Microarray Technology.

PubMed

Li, Taijie; Mo, Cuiju; Qin, Xue; Li, Shan; Liu, Yinkun; Liu, Zhiming

2018-01-01

Recently, studies have reported that protein glycosylation plays an important role in the occurrence and development of cancer. Gastric cancer is a common cancer with high morbidity and mortality owing to most gastric cancers are discovered only at an advanced stage. Here, we aim to discover novel specific serum glycanbased biomarkers for gastric cancer. A lectin microarray with 50 kinds of tumor-associated lectin was used to detect the glycan profiles of serum samples between early gastric cancer and healthy controls. Then lectin blot was performed to validate the differences. The result of the lectin microarray showed that the signal intensities of 13 lectins showed significant differences between the healthy controls and early gastric cancer. Compared to the healthy, the normalized fluorescent intensities of the lectins PWA, LEL, and STL were significantly increased, and it implied that their specifically recognized GlcNAc showed an especially elevated expression in early gastric cancer. Moreover, the binding affinity of the lectins EEL, RCA-II, RCA-I, VAL, DSA, PHA-L, UEA, and CAL were higher in the early gastric cancer than in healthy controls. These glycan structures containing GalNAc, terminal Galβ 1-4 GlcNAc, Tri/tetraantennary N-glycan, β-1, 6GlcNAc branching structure, α-linked fucose residues, and Tn antigen were elevated in gastric cancer. While the two lectins CFL GNL reduced their binding ability. In addition, their specifically recognized N-acetyl-D-galactosamine structure and (α-1,3) mannose residues were decreased in early gastric cancer. Furthermore, lectin blot results of LEL, STL, PHA-L, RCA-I were consistent with the results of the lectin microarray. The findings of our study clarify the specific alterations for glycosylation during the pathogenesis of gastric cancer. The specific high expression of GlcNAc structure may act as a potential early diagnostic marker for gastric cancer.

The homologue of mannose-binding lectin in the carp family Cyprinidae is expressed at high level in spleen, and the deduced primary structure predicts affinity for galactose.

PubMed

Vitved, L; Holmskov, U; Koch, C; Teisner, B; Hansen, S; Salomonsen, J; Skjødt, K

2000-09-01

Mannose-binding lectin (MBL) participates in the innate immune system as an activator of the complement system and as an opsonin after binding to certain carbohydrate structures on microorganisms. We isolated and characterized cDNA transcripts encoding an MBL homologue from three members of the carp family Cyprinidae, the zebrafish Danio rerio, the goldfish Carassius auratus, and the carp Cyprinus carpio. The carp and zebrafish transcripts contain two polyadenylation sites and RT-PCR on mRNA from carp tissues revealed the carp transcript to be most prominently expressed in the spleen. The deduced mature proteins contain 228 or 233 amino acids with a short N-terminal segment containing a single conserved cysteine expected to form interchain disulfide bridges, a collagen domain interrupted by four amino acids between two glycine residues, a neck region predicted to form an alpha-helical coiled-coil structure, and a C-terminal carbohydrate recognition domain (CRD). Several of the structurally important residues in the CRD are conserved, but the residues known to interact with the calcium ion and hydroxyl groups of the carbohydrate ligand are different. The amino acid motif EPN, important for mannose specificity, was QPD in the Cyprinidae homologue, suggesting specificity for galactose instead. The identity between the deduced amino acid sequences is more than 90% between the carp and the goldfish and 68% and 65% between these two species, respectively, and the zebrafish. The identity with bird and mammalian MBLs ranges from 28 to 33%.

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

Characterization of C-type lectins reveals an unexpectedly limited interaction between Cryptococcus neoformans spores and Dectin-1

PubMed Central

Walsh, Naomi M.; Wuthrich, Marcel; Wang, Huafeng; Klein, Bruce; Hull, Christina M.

2017-01-01

Phagocytosis by innate immune cells is an important process for protection against multiple pathologies and is particularly important for resistance to infection. However, phagocytosis has also been implicated in the progression of some diseases, including the dissemination of the human fungal pathogen, Cryptococcus neoformans. Previously, we identified Dectin-1 as a likely phagocytic receptor for C. neoformans spores through the use of soluble components in receptor-ligand blocking experiments. In this study, we used gain-of-function and loss-of-function assays with intact cells to evaluate the in vivo role of Dectin-1 and other C-type lectins in interactions with C. neoformans spores and discovered stark differences in outcome when compared with previous assays. First, we found that non-phagocytic cells expressing Dectin-1 were unable to bind spores and that highly sensitive reporter cells expressing Dectin-1 were not stimulated by spores. Second, we determined that some phagocytes from Dectin-1-/- mice interacted with spores differently than wild type (WT) cells, but the effects varied among assays and were modest overall. Third, while we detected small but statistically significant reductions in phagocytosis by primary alveolar macrophages from Dectin-1-/- mice compared to WT, we found no differences in survival between WT and Dectin-1-/- mice challenged with spores. Further analyses to assess the roles of other C-type lectins and their adapters revealed very weak stimulation of Dectin-2 reporter cells by spores and modest differences in binding and phagocytosis by Dectin-2-/- bone marrow-derived phagocytes. There were no discernable defects in binding or phagocytosis by phagocytes lacking Mannose Receptor, Mincle, Card-9, or FcRγ. Taken together, these results lead to the conclusion that Dectin-1 and other C-type lectins do not individually play a major roles in phagocytosis and innate defense by phagocytes against C. neoformans spores and highlight

In vivo efficacy of biapenem with ME1071, a novel metallo-β-lactamase (MBL) inhibitor, in a murine model mimicking ventilator-associated pneumonia caused by MBL-producing Pseudomonas aeruginosa.

PubMed

Yamada, Koichi; Yanagihara, Katsunori; Kaku, Norihito; Harada, Yosuke; Migiyama, Yohei; Nagaoka, Kentaro; Morinaga, Yoshitomo; Nakamura, Shigeki; Imamura, Yoshifumi; Miyazaki, Taiga; Izumikawa, Koichi; Kakeya, Hiroshi; Hasegawa, Hiroo; Yasuoka, Akira; Kohno, Shigeru

2013-09-01

ME1071, a maleic acid derivative, is a novel, specific inhibitor of metallo-β-lactamases (MBLs). In vitro, ME1071 can potentiate the activity of carbapenems against MBL-producing Pseudomonas aeruginosa. To confirm the clinical efficacy of ME1071 in ventilator-associated pneumonia (VAP) caused by MBL-producing P. aeruginosa, a mouse model that mimics VAP by placement of a plastic tube in the bronchus was used. Biapenem (100 mg/kg) or ME1071 plus biapenem (each 100 mg/kg) was administered intraperitoneally every 12 h beginning at 12 h after inoculation. Survival was evaluated over 7 days. At 30 h post infection, mice were sacrificed and the numbers of viable bacteria in the lungs and bronchoalveolar lavage fluid (BALF) were compared. Histopathological analysis of lung specimens was also performed. The pharmacokinetics of ME1071 was analysed after initial treatment. The ME1071 plus biapenem combination group displayed significantly longer survival compared with the control and biapenem monotherapy groups (P<0.05). Furthermore, the number of viable bacteria in the lungs was significantly lower in the combination group (P<0.05). Histopathological examination of lung specimens indicated that progression of lung inflammation was prevented in the combination group. Furthermore, total cell and neutrophil counts, as well as cytokine levels, in BALF were significantly decreased (P<0.05) in the combination group. The percentage time above the MIC (%T>MIC) for biapenem without ME1071 was 0% in plasma; however, this value was elevated to 10.8% with ME1071. These results suggest that ME1071 is potent and effective for treatment of VAP caused by MBL-producing P. aeruginosa. Copyright © 2013 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

EVA-1 functions as an UNC-40 Co-receptor to enhance attraction to the MADD-4 guidance cue in Caenorhabditis elegans.

PubMed

Chan, Kevin Ka Ming; Seetharaman, Ashwin; Bagg, Rachel; Selman, Guillermo; Zhang, Yuqian; Kim, Joowan; Roy, Peter J

2014-08-01

We recently discovered a secreted and diffusible midline cue called MADD-4 (an ADAMTSL) that guides migrations along the dorsoventral axis of the nematode Caenorhabditis elegans. We showed that the transmembrane receptor, UNC-40 (DCC), whose canonical ligand is the UNC-6 (netrin) guidance cue, is required for extension towards MADD-4. Here, we demonstrate that MADD-4 interacts with an EVA-1/UNC-40 co-receptor complex to attract cell extensions. EVA-1 is a conserved transmembrane protein with predicted galactose-binding lectin domains. EVA-1 functions in the same pathway as MADD-4, physically interacts with both MADD-4 and UNC-40, and enhances UNC-40's sensitivity to the MADD-4 cue. This enhancement is especially important in the presence of UNC-6. In EVA-1's absence, UNC-6 interferes with UNC-40's responsiveness to MADD-4; in UNC-6's absence, UNC-40's responsiveness to MADD-4 is less dependent on EVA-1. By enabling UNC-40 to respond to MADD-4 in the presence of UNC-6, EVA-1 may increase the precision by which UNC-40-directed processes can reach their MADD-4-expressing targets within a field of the UNC-6 guidance cue.

EVA-1 Functions as an UNC-40 Co-receptor to Enhance Attraction to the MADD-4 Guidance Cue in Caenorhabditis elegans

PubMed Central

Bagg, Rachel; Selman, Guillermo; Zhang, Yuqian; Kim, Joowan; Roy, Peter J.

2014-01-01

We recently discovered a secreted and diffusible midline cue called MADD-4 (an ADAMTSL) that guides migrations along the dorsoventral axis of the nematode Caenorhabditis elegans. We showed that the transmembrane receptor, UNC-40 (DCC), whose canonical ligand is the UNC-6 (netrin) guidance cue, is required for extension towards MADD-4. Here, we demonstrate that MADD-4 interacts with an EVA-1/UNC-40 co-receptor complex to attract cell extensions. EVA-1 is a conserved transmembrane protein with predicted galactose-binding lectin domains. EVA-1 functions in the same pathway as MADD-4, physically interacts with both MADD-4 and UNC-40, and enhances UNC-40's sensitivity to the MADD-4 cue. This enhancement is especially important in the presence of UNC-6. In EVA-1's absence, UNC-6 interferes with UNC-40's responsiveness to MADD-4; in UNC-6's absence, UNC-40's responsiveness to MADD-4 is less dependent on EVA-1. By enabling UNC-40 to respond to MADD-4 in the presence of UNC-6, EVA-1 may increase the precision by which UNC-40-directed processes can reach their MADD-4-expressing targets within a field of the UNC-6 guidance cue. PMID:25122090

Lipopolysaccharide-specific binding C-type lectin with one CRD domain from Fenneropenaeus merguiensis (FmLC4) functions as a pattern recognition receptor in shrimp innate immunity.

PubMed

Utarabhand, Prapaporn; Thepnarong, Supattra; Runsaeng, Phanthipha

2017-10-01

In crustaceans, an innate immune system is solely required because they lack an adaptive immunity. One kind of pattern recognition receptors (PRRs) that plays a particular role in the innate immunity of aquatic shrimp is lectin. A new diverse C-type lectin (FmLC4) was cloned from the hepatopancreas of Fenneropenaeus merguiensis by using RT-PCR and 5' and 3' rapid amplification of cDNA ends approaches. A full-length FmLC4 cDNA comprises 706 bp with an open reading frame of 552 bp, encoding a peptide of 184 amino acids. The predicted primary sequence of FmLC4 consists of a signal peptide of 19 amino acids, a molecular mass of 20.4 kDa, an isoelectric point of 5.13, one carbohydrate recognition domain with a QPD motif and a Ca 2+ binding site as well as a double-loop characteristic supported by two conserved disulfide bonds. The FmLC4 mRNA expression was found only in the hepatopancreas of normal shrimp and significantly up-regulated upon challenge the shrimp with Vibrio harveyi or white spot syndrome virus (WSSV). Recombinant FmLC4 (rFmLC4) could agglutinate various bacterial strains with Ca 2+ -dependence. Lipopolysaccharide (LPS) could specifically inhibit the agglutinating activity and potently bind to rFmLC4, indicating that FmLC4 was LPS-specific binding C-type lectin. Moreover, rFmLC4 itself displayed the in vivo effective clearance of the pathogenic bacterium V. harveyi. Altogether, FmLC4 may serve as LPS-specific PRR to recognize opportunistic bacterial and viral pathogens, and thus to play a role in the immune defense of aquatic shrimp via the binding and agglutination. Copyright © 2017 Elsevier Ltd. All rights reserved.

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. .

Lectin cDNA and transgenic plants derived therefrom

DOEpatents

Raikhel, Natasha 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.

Purification and characterization of liver lectins from a lizard, Sceloporus spinosus.

PubMed

Fenton, N Bertha; Arreguín, L Barbarin; Méndez, C Fausto; Arreguín, E Roberto

2004-05-01

This study discusses the purification of soluble beta-galactose lectins obtained from the lizard liver of Sceloporus spinosus. The first lectin named lizard hepatic lectin-1 (LHL-1) presented a molecular weight of 31,750, with an isoelectric point of 4.25. The highest specific hemagglutinating activity was achieved using human blood type A1: N-acetylgalactosamine (GalNAc)-galactose (Gal)-fucose (Fuc). Carbohydrate inhibition assays indicated a higher lectin specificity for GalNAc. For LHL-2 the molecular weight obtained was 23,850 with an isoelectric point of 3.25. The highest carbohydrate specificity was observed for Gal. These lizard hepatic lectins are similar to the mammal hepatic lectins previously reported. However, it is different from the alligator hepatic lectin (AHL). The homology analyses of LHL-1 resulted in 100% identity with the Steroidogenic acute regulatory protein (StAR), while LHL-2 was similar to adenylate kinase (75% identity). We suggest that these liver lectins are related to the inherent functions of liver previously reported.

Use of lectin microarray to differentiate gastric cancer from gastric ulcer

PubMed Central

Huang, Wei-Li; Li, Yang-Guang; Lv, Yong-Chen; Guan, Xiao-Hui; Ji, Hui-Fan; Chi, Bao-Rong

2014-01-01

AIM: To investigate the feasibility of lectin microarray for differentiating gastric cancer from gastric ulcer. METHODS: Twenty cases of human gastric cancer tissue and 20 cases of human gastric ulcer tissue were collected and processed. Protein was extracted from the frozen tissues and stored. The lectins were dissolved in buffer, and the sugar-binding specificities of lectins and the layout of the lectin microarray were summarized. The median of the effective data points for each lectin was globally normalized to the sum of medians of all effective data points for each lectin in one block. Formalin-fixed paraffin-embedded gastric cancer tissues and their corresponding gastric ulcer tissues were subjected to Ag retrieval. Biotinylated lectin was used as the primary antibody and HRP-streptavidin as the secondary antibody. The glycopatterns of glycoprotein in gastric cancer and gastric ulcer specimens were determined by lectin microarray, and then validated by lectin histochemistry. Data are presented as mean ± SD for the indicated number of independent experiments. RESULTS: The glycosylation level of gastric cancer was significantly higher than that in ulcer. In gastric cancer, most of the lectin binders showed positive signals and the intensity of the signals was stronger, whereas the opposite was the case for ulcers. Significant differences in the pathological score of the two lectins were apparent between ulcer and gastric cancer tissues using the same lectin. For MPL and VVA, all types of gastric cancer detected showed stronger staining and a higher positive rate in comparison with ulcer, especially in the case of signet ring cell carcinoma and intra-mucosal carcinoma. GalNAc bound to MPL showed a significant increase. A statistically significant association between MPL and gastric cancer was observed. As with MPL, there were significant differences in VVA staining between gastric cancer and ulcer. CONCLUSION: Lectin microarray can differentiate the different

The Global Challenge in Neuroscience Education and Training: The MBL Perspective.

PubMed

Nishi, Rae; Castañeda, Edward; Davis, Graeme W; Fenton, André A; Hofmann, Hans A; King, Jean; Ryan, Timothy A; Trujillo, Keith A

2016-11-02

The greatest challenge in moving neuroscience research forward in the 21st century is recruiting, training, and retaining the brightest, rigorous, and most diverse scientists. The MBL research training courses Neurobiology and Neural Systems & Behavior, and the Summer Program in Neuroscience, Excellence, and Success provide a model for full immersion, discovery-based training while enhancing cultural, geographic, and racial diversity. Copyright © 2016 Elsevier Inc. All rights reserved.

Comparative study of anti-angiogenic activities of luteolin, lectin and lupeol biomolecules.

PubMed

Ambasta, Rashmi K; Jha, Saurabh Kumar; Kumar, Dhiraj; Sharma, Renu; Jha, Niraj Kumar; Kumar, Pravir

2015-09-18

Angiogenesis is a hallmark feature in the initiation, progression and growth of tumour. There are various factors for promotion of angiogenesis on one hand and on the other hand, biomolecules have been reported to inhibit cancer through anti-angiogenesis mechanism. Biomolecules, for instance, luteolin, lectin and lupeol are known to suppress cancer. This study aims to compare and evaluate the biomolecule(s) like luteolin, lupeol and lectin on CAM assay and HT-29 cell culture to understand the efficacy of these drugs. The biomolecules have been administered on CAM assay, HT-29 cell culture, cell migration assay. Furthermore, bioinformatics analysis of the identified targets of these biomolecules have been performed. Luteolin has been found to be better in inhibiting angiogenesis on CAM assay in comparison to lupeol and lectin. In line with this study when biomolecules was administered on cell migration assay via scratch assay method. We provided evidence that Luteolin was again found to be better in inhibiting HT-29 cell migration. In order to identify the target sites of luteolin for inhibition, we used software analysis for identifying the best molecular targets of luteolin. Using software analysis best target protein molecule of these biomolecules have been identified. VEGF was found to be one of the target of luteolin. Studies have found several critical point mutation in VEGF A, B and C. Hence docking analysis of all biomolecules with VEGFR have been performed. Multiple allignment result have shown that the receptors are conserved at the docking site. Therefore, it can be concluded that luteolin is not only comparatively better in inhibiting blood vessel in CAM assay, HT-29 cell proliferation and cell migration assay rather the domain of VEGFR is conserved to be targeted by luteolin, lupeol and lectin.

Effects of Lectins on initial attachment of cariogenic Streptococcus mutans.

PubMed

Ito, Takashi; Yoshida, Yasuhiro; Shiota, Yasuyoshi; Ito, Yuki; Yamamoto, Tadashi; Takashiba, Shogo

2018-02-01

Oral bacteria initiate biofilm formation by attaching to tooth surfaces via an interaction of a lectin-like bacterial protein with carbohydrate chains on the pellicle. This study aimed to find naturally derived lectins that inhibit the initial attachment of a cariogenic bacterial species, Streptococcus mutans (S. mutans), to carbohydrate chains in saliva in vitro. Seventy kinds of lectins were screened for candidate motifs that inhibit the attachment of S. mutans ATCC 25175 to a saliva-coated culture plate. The inhibitory effect of the lectins on attachment of the S. mutans to the plates was quantified by crystal violet staining, and the biofilm was observed under a scanning electron microscope (SEM). Surface plasmon resonance (SPR) analysis was performed to examine the binding of S. mutans to carbohydrate chains and the binding of candidate lectins to carbohydrate chains, respectively. Moreover, binding assay between the biotinylated-lectins and the saliva components was conducted to measure the lectin binding. Lectins recognizing a salivary carbohydrate chain, Galβ1-3GalNAc, inhibited the binding of S. mutans to the plate. In particular, Agaricus bisporus agglutinin (ABA) markedly inhibited the binding. This inhibition was confirmed by SEM observation. SPR analysis indicated that S. mutans strongly binds to Galβ1-3GalNAc, and ABA binds to Galβ1-3GalNAc. Finally, the biotinylated Galβ1-3GalNAc-binding lectins including ABA demonstrated marked binding to the saliva components. These results suggest that ABA lectin inhibited the attachment of S. mutans to Galβ1-3GalNAc in saliva and ABA can be useful as a potent inhibitor for initial attachment of oral bacteria and biofilm formation.

Molecular cloning and characterization of a C-type lectin in yellow catfish Tachysurus fulvidraco.

PubMed

Ke, F; Zhang, H B; Wang, Y; Hou, L F; Dong, H J; Wang, Z F; Pan, G W; Cao, X Y

2016-09-01

This study represents the first report of a C-type lectin (ctl) in yellow catfish Tachysurus fulvidraco. The complete sequence of ctl complementary (c)DNA consisted of 685 nucleotides. The open reading frame potentially encoded a protein of 177 amino acids with a calculated molecular mass of c.y 20.204 kDa. The deduced amino-acid sequence contained a signal peptide and a single carbohydrate recognition domain with four cysteine residues and GlnProAsp (QPD) and TrpAsnAsp (WND) motifs. Ctl showed the highest identity (56.0%) to the predicted lactose binding lectin from channel catfish Ictalurus punctatus. Quantitative real-time (qrt)-PCR analysis showed that ctl messenger (m)RNA was constitutively expressed in all examined tissues in normal fish, with high expression in trunk kidney and head kidney, which was increased following Aeromonas hydrophila challenge in a duration-dependent manner. Purified recombinant Ctl (rCtl) from Escherichia coli BL21 was able to bind and agglutinate Gram-positive and Gram-negative bacteria in a calcium-dependent manner. These results suggested that Ctl might be a C-type lectin of T. fulvidraco involved in innate immune responses as receptors (PRR). © 2016 The Fisheries Society of the British Isles.

21 CFR 864.9550 - Lectins and protectins.

Code of Federal Regulations, 2010 CFR

2010-04-01

... antigens. These substances are used to detect blood group antigens for in vitro diagnostic purposes. (b...) 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...

Lectin histochemistry reveals SNA as a prognostic carbohydrate-dependent probe for invasive ductal carcinoma of the breast: a clinicopathological and immunohistochemical auxiliary tool

PubMed Central

dos-Santos, Petra B; Zanetti, Juliana S; Vieira-de-Mello, Gabriela S; Rêgo, Moacyr BM; A, Alfredo Ribeiro-Silva; Beltrão, Eduardo Isidoro Carneiro

2014-01-01

Increased sialylation and β1,6-branched oligosaccharides has been associated with a variety of structural changes in cell surface carbohydrates, most notably in tumorigenesis. Lectins are defined as proteins that preferentially recognize and bind carbohydrate complexes protruding from glycolipids and glycoproteins. This interaction with carbohydrates can be as specific as the interaction between antigen and antibody. Due to this type of interaction lectins have been used as experimental auxiliary tools in histopathological diagnosis of cancer. This study was designed to evaluate the differential expression of sialic acids and β1,6-N-acetylglucosaminyltransferase V (MGAT5) in invasive (IDC) and in situ (DCIS) ductal carcinoma of the breast and its possible application as prognostic biomarkers. A possible transition between pre-malign and malign lesions was evaluated using DCIS samples. Biopsies were analyzed regarding the expression of MUC1, p53, Ki-67, estrogen receptor, progesterone receptor, HER-2 and MGAT5. α2,6-linked sialic acids residues recognized by SNA lectin was overexpressed in 33.3% of IDC samples and it was related with Ki-67 (p=0.042), PR (p=0.029), lymphnodes status (p=0.017) and death (p=0.011). Regarding survival analysis SNA was the only lectin able to correlate with specific-disease survival and disease-free survival (p=0.024 and p=0.041, respectively), besides, it presents itself as an independent variable by Cox Regression analysis (p= 0.004). Comparing IDC and DCIS cases, only SNA showed different staining pattern (p=0.034). The presence of sialic acids on tumor cell surface can be an indicative of poor prognosis and our study provides further evidence that SNA lectin can be used as a prognostic probe in IDC and DCIS patients. PMID:24966944

Dectin-2 Is a C-Type Lectin Receptor that Recognizes Pneumocystis and Participates in Innate Immune Responses.

PubMed

Kottom, Theodore J; Hebrink, Deanne M; Jenson, Paige E; Marsolek, Paige L; Wüthrich, Marcel; Wang, Huafeng; Klein, Bruce; Yamasaki, Sho; Limper, Andrew H

2018-02-01

Pneumocystis is an important fungal pathogen that causes life-threatening pneumonia in patients with AIDS and malignancy. Lung fungal pathogens are recognized by C-type lectin receptors (CLRs), which bind specific ligands and stimulate innate immune responses. The CLR Dectin-1 was previously shown to mediate immune responses to Pneumocystis spp. For this reason, we investigated a potential role for Dectin-2. Rats with Pneumocystis pneumonia (PCP) exhibited elevated Dectin-2 mRNA levels. Soluble Dectin-2 carbohydrate-recognition domain fusion protein showed binding to intact Pneumocystis carinii (Pc) and to native Pneumocystis major surface glycoprotein/glycoprotein A (Msg/gpA). RAW macrophage cells expressing V5-tagged Dectin-2 displayed enhanced binding to Pc and increased protein tyrosine phosphorylation. Furthermore, the binding of Pc to Dectin-2 resulted in Fc receptor-γ-mediated intracellular signaling. Alveolar macrophages from Dectin-2-deficient mice (Dectin-2 -/- ) showed significant decreases in phospho-Syk activation after challenge with Pc cell wall components. Stimulation of Dectin-2 -/- alveolar macrophages with Pc components showed significant decreases in the proinflammatory cytokines IL-6 and TNF-α. Finally, during infection with Pneumocystis murina, Dectin-2 -/- mice displayed downregulated mRNA expression profiles of other CLRs implicated in fungal immunity. Although Dectin-2 -/- alveolar macrophages had reduced proinflammatory cytokine release in vitro, Dectin-2 -/- deficiency did not reduce the overall resistance of these mice in the PCP model, and organism burdens were statistically similar in the long-term immunocompromised and short-term immunocompetent PCP models. These results suggest that Dectin-2 participates in the initial innate immune signaling response to Pneumocystis, but its deficiency does not impair resistance to the organism.

The molecular determinants of CD8 co-receptor function.

PubMed

Cole, David K; Laugel, Bruno; Clement, Mathew; Price, David A; Wooldridge, Linda; Sewell, Andrew K

2012-10-01

CD8(+) T cells respond to signals mediated through a specific interaction between the T-cell receptor (TCR) and a composite antigen in the form of an epitopic peptide bound between the polymorphic α1 and α2 helices of an MHC class I (MHCI) molecule. The CD8 glycoprotein 'co-receives' antigen by binding to an invariant region of the MHCI molecule and can enhance ligand recognition by up to 1 million-fold. In recent years, a number of structural and biophysical investigations have shed light on the role of the CD8 co-receptor during T-cell antigen recognition. Here, we provide a collated resource for these data, and discuss how the structural and biophysical parameters governing CD8 co-receptor function further our understanding of T-cell cross-reactivity and the productive engagement of low-affinity antigenic ligands. © 2012 The Authors. Immunology © 2012 Blackwell Publishing Ltd.

Purification and characterization of a novel thermostable mycelial lectin from Aspergillus terricola.

PubMed

Singh, Ram Sarup; Bhari, Ranjeeta; Kaur, Hemant Preet; Vig, Monika

2010-11-01

Lectin has been isolated from mycelia of Aspergillus terricola by single step purification on porcine stomach mucin-Sepharose 4B affinity column. Lectin could be effectively purified with 75% recovery and 4.47-fold increase in specific activity. Lectin migrated as a single band on SDS-PAGE with an apparent molecular mass of 32.5 kDa. Sugar inhibition assay revealed that the lectin did not strongly interact with most carbohydrates and their derivatives tested while strong binding affinity to D-glucose, D-sucrose, N-acetyl-D-galactosamine, asialofetuin, porcine stomach mucin, and bovine submaxillary mucin was indicated. Neuraminidase and protease treatment to erythrocytes enhanced lectin titre. Lectin activity was stable within the pH range of 7.0-10.5. A. terricola lectin displayed remarkable thermostability and remained unaffected upon incubation at 70 degrees C for 2.5 h. Lectin did not require metal ions for its activity. Incubation with denaturants (urea, thiourea, and guanidine-HCl) substantially reduced lectin activity. Carbohydrate analysis revealed that it is a glycoprotein with 9.76% total sugars.

Potential immunomodulatory effects of plant lectins in Schistosoma mansoni infection.

PubMed

Reis, Eliana A G; Athanazio, Daniel A; Cavada, Benildo Sousa; Teixeira, Edson Holanda; de Paulo Teixeira Pinto, Vicente; Carmo, Theomira M A; Reis, Alice; Trocolli, Graziela; Croda, Julio; Harn, Donald; Barral-Netto, Manoel; Reis, Mitermayer G

2008-01-01

Lectins are sugar-binding glycoproteins that can stimulate, in a non-antigen-specific fashion, lymphocytes, leading to proliferation and cytokine production. Some lectins are utilized as in vitro mitogenic lymphocyte stimulators and their use as immunomodulators against infectious diseases has been evaluated experimentally. In the experimental murine model, the immune response to schistosomiasis is Th1-like during the initial stage of infection, with a shift towards a Th2-like response after oviposition. We report the response of schistosomiasis patients' (n=37) peripheral blood mononuclear cells (PBMC) to stimulation by lectins, including newly isolated lectins from Brazilian flora, and by Schistosomamansoni soluble egg antigens (SEA). Cytokine production upon lectin stimulation ex vivo was assessed in PBMC supernatants, collected at 24 and 72 h, by sandwich ELISA to IL-5, IL-10, TNF-alpha and IFN-gamma. In PBMC from infected patients all but one of the lectins induced a Th2-like cytokine response, characterized by elevated IL-5 production that was higher than that induced by SEA stimulation alone. Our results show that the Th2 environment present during schistosomiasis is not affected and that it may be further stimulated by the presence of lectins.

Structure and Function of Mammalian Carbohydrate-Lectin Interactions

NASA Astrophysics Data System (ADS)

Anderson, Kevin; Evers, David; Rice, Kevin G.

Over the past three decades the field of glycobiology has expanded beyond a basic understanding of the structure and biosynthesis of glycoprotein, proteoglycans, and glycolipids toward a more detailed picture of how these molecules afford communication through binding to mammalian lectins. Although the number of different mammalian lectin domains appears to be finite and even much smaller than early estimates predicated based on the diversity of glycan structures, nature appears capable of using these in numerous combinations to fine tune specificity. The following provides an overview of the major classes of mammalian lectins and discusses their glycan binding specificity. The review provides a snapshot of the field of glycobiology that continues to grow providing an increasing number of examples of biological processes that rely upon glycan-lectin binding.

CsMAP34, a teleost MAP with dual role: A promoter of MASP-assisted complement activation and a regulator of immune cell activity.

PubMed

Li, Mo-Fei; Li, Jun; Sun, Li

2016-12-23

In teleost fish, the immune functions of mannan-binding lectin (MBL) associated protein (MAP) and MBL associated serine protease (MASP) are scarcely investigated. In the present study, we examined the biological properties both MAP (CsMAP34) and MASP (CsMASP1) molecules from tongue sole (Cynoglossus semilaevis). We found that CsMAP34 and CsMASP1 expressions occurred in nine different tissues and were upregulated by bacterial challenge. CsMAP34 protein was detected in blood, especially during bacterial infection. Recombinant CsMAP34 (rCsMAP34) bound C. semilaevis MBL (rCsBML) when the latter was activated by bacteria, while recombinant CsMASP1 (rCsMASP1) bound activated rCsBML only in the presence of rCsMAP34. rCsMAP34 stimulated the hemolytic and bactericidal activities of serum complement, whereas anti-CsMAP34 antibody blocked complement activities. Knockdown of CsMASP1 in C. semilaevis resulted in significant inhibition of complement activities. Furthermore, rCsMAP34 interacted directly with peripheral blood leukocytes (PBL) and enhanced the respiratory burst, acid phosphatase activity, chemotactic activity, and gene expression of PBL. These results indicate for the first time that a teleost MAP acts one hand as a regulator that promotes the lectin pathway of complement activation via its ability to recruit MBL to MASP, and other hand as a modulator of immune cell activity.

Visualizing the dental biofilm matrix by means of fluorescence lectin-binding analysis.

PubMed

Tawakoli, Pune N; Neu, Thomas R; Busck, Mette M; Kuhlicke, Ute; Schramm, Andreas; Attin, Thomas; Wiedemeier, Daniel B; Schlafer, Sebastian

2017-01-01

The extracellular matrix is a poorly studied, yet important component of dental biofilms. Fluorescence lectin-binding analysis (FLBA) is a powerful tool to characterize glycoconjugates in the biofilm matrix. This study aimed to systematically investigate the ability of 75 fluorescently labeled lectins to visualize and quantify extracellular glycoconjugates in dental biofilms. Lectin binding was screened on pooled supragingival biofilm samples collected from 76 subjects using confocal microscopy. FLBA was then performed with 10 selected lectins on biofilms grown in situ for 48 h in the absence of sucrose. For five lectins that proved particularly suitable, stained biovolumes were quantified and correlated to the bacterial composition of the biofilms. Additionally, combinations of up to three differently labeled lectins were tested. Of the 10 lectins, five bound particularly well in 48-h-biofilms: Aleuria aurantia (AAL), Calystega sepiem (Calsepa), Lycopersicon esculentum (LEA), Morniga-G (MNA-G) and Helix pomatia (HPA). No significant correlation between the binding of specific lectins and bacterial composition was found. Fluorescently labeled lectins enable the visualization of glycoconjugates in the dental biofilm matrix. The characterization and quantification of glycoconjugates in dental biofilms require a combination of several lectins. For 48-h-biofilms grown in absence of sucrose, AAL, Calsepa, HPA, LEA, and MNA-G are recommendable.

Upper airway CO2 receptors in tegu lizards: localization and ventilatory sensitivity.

PubMed

Coates, E L; Ballam, G O

1987-01-01

1. Tidal volume, end-tidal CO2, and ventilatory frequency in Tupinambis nigropunctatus were measured in response to CO2 (1-4%) delivered to either the mouth or nares. Additionally, the sensitivity of the ventilatory response to nasal CO2 was evaluated at CO2 concentrations less than 1%. The ventilatory parameters were also measured in response to CO2 (1-4%) delivered to the nares after the olfactory peduncle was transected. 2. It was found that (0.4-4%) nasal CO2 depressed ventilatory frequency by 9% to 83% respectively, while tidal volume was not significantly altered. CO2 (1-4%) delivered to the mouth produced no apparent changes in any of the ventilatory parameters. Following transection of the olfactory peduncle, nasal CO2 was ineffective in producing any change in ventilatory frequency or depth. 3. These findings indicate that CO2-sensitive receptors are located in either the nasal or vomeronasal membranes of tegu lizards and that the olfactory peduncle must be intact for these receptors to affect ventilatory changes in response to elevated CO2 concentrations. The receptors are capable of mediating a ventilatory response to CO2 concentrations lower than those found in either expired air or in confined spaces such as occupied burrows. 4. The discrepancies in the ventilatory responses of lizards and snakes to inspired CO2 reported in past experiments may be partially explained by the presence of nasal or vomeronasal CO2-sensitive receptors.

Crystallization and preliminary characterization of a highly thermostable lectin from Trichosanthes dioica and comparison with other Trichosanthes lectins

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

Dharkar, Poorva D.; Anuradha, P.; Gaikwad, Sushama M.

2006-03-01

A lectin from Trichosanthes dioica seeds has been purified and crystallized using 25%(w/v) PEG 2K MME, 0.2 M ammonium acetate, 0.1 M Tris–HCl pH 8.5 and 50 µl 0.5%(w/v) n-octyl β-d-glucopyranoside as thick needles belonging to hexagonal space group P6{sub 4}. A lectin from Trichosanthes dioica seeds has been purified and crystallized using 25%(w/v) PEG 2K MME, 0.2 M ammonium acetate, 0.1 M Tris–HCl pH 8.5 and 50 µl 0.5%(w/v) n-octyl β-d-glucopyranoside as thick needles belonging to hexagonal space group P6{sub 4}. Unit-cell parameters were a = b = 167.54, c = 77.42 Å. The crystals diffracted to a Braggmore » spacing of 2.8 Å. Both the structures of abrin-a and T. kirilowii lectin could be used as a model in structure determination using the molecular-replacement method; however, T. kirilowii lectin coordinates gave better values of reliability and correlation parameters. The thermal, chemical and pH stability of this lectin have also been studied. When heated, its haemagglutination activity remained unaffected up to 363 K. Other stability studies show that 4 M guanidinium hydrochloride (Gdn–HCl) initiates unfolding and that the protein is completely unfolded at 6 M Gdn–HCl. Treatment with urea resulted in a total loss of activity at higher concentrations of denaturant with no major structural changes. The protein remained stable over a wide pH range, from pH 6 to pH 12, except for partial unfolding at extremely alkaline pH. The role of disulfide bonds in the protein stability was found to be insignificant. Rayleigh light-scattering studies showed no molecular aggregation in any of the extreme treated conditions. The unusual stability of this lectin resembles that of type II ribosome-inactivating proteins (type II RIPs), which is also supported by structure determination. The structural features observed in a preliminary electron-density map were compared with the other two available Trichosanthes lectin structures.« less

Comparative study of hemagglutination and lectin activity in Australian medicinal mushrooms (higher Basidiomycetes).

PubMed

Rouf, Razina; Tiralongo, Evelin; Krahl, Anja; Maes, Karen; Spaan, Lina; Wolf, Stefan; May, Tom W; Tiralongo, Joe

2011-01-01

Fifteen Australian mushroom species (higher Basidiomycetes) were assessed for hemagglutination and lectin activity. Hemagglutination activity was evaluated using both neuraminidase treated and untreated rabbit and human A, B, and O erythrocytes. Lectin activity was determined by the ability of various mono- and oligosaccharides to inhibit hemagglutination activity. Of the mushrooms evaluated, seven contained lectin activity. However, five (Agaricus bitorquis, Chlorophyllum brunneum, Coprinus comatus, Cortinarius sp. TWM 1710, and Omphalotus nidiformis) expressed lectin activity in only one of two collections tested. The two remaining lectin active mushroom species (Phlebopus marginatus and Psathyrella asperospora) possessed lectin activity with the same sugar specificity in both collections. Although lectins were identified with diverse specificity, lactose-specific lectin activity was most frequently identified, being present in Agaricus bitorquis, Copronus comatus, Omphalotus nidiformis, and Phlebopus marginatus. In contrast, Psathyrella asperospora, Cortinarius sp. TWM 1710, and Chlorophyllum brunneum were found to possess lectin activity specific for N-acetyl-D-glucosamine, galactose, and N-acetyl-neurammic acid, respectively. Significantly, the galactose-specific lectin activity identified in Cortinarius sp. TWM 1710 and the lactose-specific lectin activity in Phlebopus marginatus have not been previously reported.

Genetic Variation Linked to Lung Cancer Survival in White Smokers | Center for Cancer Research

Cancer.gov

CCR investigators have discovered evidence that links lung cancer survival with genetic variations (called single nucleotide polymorphisms) in the MBL2 gene, a key player in innate immunity. The variations in the gene, which codes for a protein called the mannose-binding lectin, occur in its promoter region, where the RNA polymerase molecule binds to start transcription, and in the first exon that is responsible for the correct structure of MBL. The findings appear in the September 19, 2007, issue of the Journal of the National Cancer Institute.

In-house preparation of lectin panel and detection of Tn polyagglutination.

PubMed

Das, Sudipta Sekhar

2015-01-01

Polyagglutination is a condition in which red cells are agglutinated by ABO-compatible adult human sera, but not by cord blood sera and may be acquired or inherited. Lectins are invaluable reagents in the investigation of red cells polyagglutination. We prepared in-house lectin panel and confirmed Tn polyagglutination in a pregnant lady. The lady was anemic and refused blood transfusion elsewhere due to serological discrepancy. We found ABO discrepancy and an incompatible minor cross-match in the initial investigation and suspected polyagglutination. Confirmation of polyagglutination was done using adult and cord sera. We then used the in-house lectin panels to detect the type of polyagglutination. The agglutination pattern with the various lectins was suggestive of Tn polyagglutination, which was further supported by the enzyme study. Most blood banks in India lack commercial lectin panels because of cost and procurement difficulty. Lectins play an important role in the diagnosis and differentiation of polyagglutination and immunohematological management of patient. The important and basic lectins can be prepared in-house using specific raw seeds following standardized protocol.

Affinity entrapment of oligosaccharides and glycopeptides using free lectin solution.

PubMed

Yodoshi, Masahiro; Oyama, Takehiro; Masaki, Ken; Kakehi, Kazuaki; Hayakawa, Takao; Suzuki, Shigeo

2011-01-01

Two procedures were proposed for the specific recovery of fluorescent derivatives of glycoprotein-derived oligosaccharides and tryptic glycopeptides using certain plant lectins. The first was based on the salting out of oligosaccharide-lectin conjugates with ammonium sulfate. Oligosaccharides specifically bound to lectins were recovered free from lectins using ethanol precipitation after dissolution in water. This method enabled group separation of 2-aminopyridine-labeled oligosaccharides derived from ovalbumin to galacto-oligosaccharides and agalacto-oligosaccharides by Ricinus communis agglutinin, and to high mannose- and hybrid-type oligosaccharides by wheat-germ agglutinin. Fractional precipitation based on differences in affinity for concanavalin A was accomplished by adding an appropriate concentration of methyl α-mannoside as an inhibitor. In the second method, tryptic digests of glycoproteins were mixed with a lectin solution, and the glycopeptide-lectin conjugates were specifically trapped on a centrifugal ultrafiltration membrane with cut-off of 10 kD. Trapped glycopeptides, as retentates, were passed through membranes by resuspension in diluted acid. This method is particularly useful for the enrichment of glycopeptides in protease digestion mixtures for glycosylation analyses by liquid chromatography-mass spectrometry.

Lectin of Bacillus subtilis sp. as overinducer of gamma-interferonogenesis.

PubMed

Kishko, Ia H; Vasylenko, M I; Pidhors'kyĭ, V S; Kovalenko, E O

1997-01-01

It has been demonstrated experimentally that lectin of Bacillus subtilis sp. in comparison with generally accepted Con A, PHA and lectin of "gold rain" grass--Laburnum anagyroides M e d i k in trials on white mice of CBA line gave in 4 hours of induction maximal titers of gamma-IFN in blood serum of animals--153.6 +/- 17.0 IU/ml. Practically identical titers had been obtained after induction by lectin "gold rain", some lower--after Con A and PHA. At swine gamma-IFN synthesis optimal density of cell suspension must contain 2.5 + 10(7) immunocytes in 1 ml, owing to which it is possible to obtain the titer equal 1 : 2150. Materials with using of bacterial lectins at various degree of purification had shown that maximal titers in blood serum of mongrel white mice were registered at administration to animals of non-purified lectin, 4 times lower--at using of half-purified and purified lectins. Data of these trials in vivo were confirmed by materials of gamma-IFN induction by immunocytes of swine, cattle and even man.

Suppression of proliferation and neurite extension of human neuroblastoma SH-SY5Y cells on immobilized Psathyrella velutina lectin.

PubMed

Kitamura, Noriaki; Ikekita, Masahiko; Hayakawa, Satoru; Funahashi, Hisayuki; Furukawa, Kiyoshi

2004-02-01

Glycoproteins from mammalian brain tissues contain unique N-linked oligosaccharides terminating with beta-N-acetylglucosamine residues. Lectin blot analysis of membrane glycoprotein samples from human neuroblastoma SH-SY5Y cells showed that several protein bands bind to Psathylera velutina lectin (PVL), which interacts with beta-N-acetylglucosamine-terminating oligosaccharides. No lectin positive bands were detected by digestion with jack bean beta-N-acetyl-hexosaminidase or N-glycanase before incubation with the lectin, indicating that the cells contain beta-N-acetylglucosamine-terminating N-linked oligosaccharides. When cells were cultured in dishes with different concentrations of PVL, the cell proliferation was inhibited in a dose-dependent manner. Similarly, the neurite extension, which was stimulated with nerve growth factor, was also inhibited in a manner dependent on the lectin dose. Cell proliferation and neurite extension were recovered by the addition of 10 mM N-acetylglucosamine into the medium. Immunoblot analysis of the activation of mitogen-activated protein (MAP) kinases and protein kinase C revealed that phosphorylation of 42-kDa and 44-kDa MAP kinases and 80-kDa protein kinase C are inhibited when SH-SY5Y cells are cultured in PVL-coated dishes, but are restored by the addition of the haptenic sugar into the medium, indicating that MAP kinase and protein kinase C pathways are inhibited by interaction with immobilized PVL. These results indicate that beta-N-acetylglucosamine-terminating N-linked oligosaccharides expressed on neural cells can induce intracellular signals upon binding to extracellular receptors, and are important for growth regulation of neural cells. Copyright 2003 Wiley-Liss, Inc.

T Cell Calcium Signaling Regulation by the Co-Receptor CD5

PubMed Central

Freitas, Claudia M. Tellez

2018-01-01

Calcium influx is critical for T cell effector function and fate. T cells are activated when T cell receptors (TCRs) engage peptides presented by antigen-presenting cells (APC), causing an increase of intracellular calcium (Ca2+) concentration. Co-receptors stabilize interactions between the TCR and its ligand, the peptide-major histocompatibility complex (pMHC), and enhance Ca2+ signaling and T cell activation. Conversely, some co-receptors can dampen Ca2+ signaling and inhibit T cell activation. Immune checkpoint therapies block inhibitory co-receptors, such as cytotoxic T-lymphocyte associated antigen 4 (CTLA-4) and programmed death 1 (PD-1), to increase T cell Ca2+ signaling and promote T cell survival. Similar to CTLA-4 and PD-1, the co-receptor CD5 has been known to act as a negative regulator of T cell activation and to alter Ca2+ signaling and T cell function. Though much is known about the role of CD5 in B cells, recent research has expanded our understanding of CD5 function in T cells. Here we review these recent findings and discuss how our improved understanding of CD5 Ca2+ signaling regulation could be useful for basic and clinical research. PMID:29701673

Plant Lectins: Wheat Defense Strategy Against Hessian Fly

USDA-ARS?s Scientific Manuscript database

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...

CaLecRK-S.5, a pepper L-type lectin receptor kinase gene, confers broad-spectrum resistance by activating priming

PubMed Central

Woo, Joo Yong; Jeong, Kwang Ju; Kim, Young Jin; Paek, Kyung-Hee

2016-01-01

In Arabidopsis, several L-type lectin receptor kinases (LecRKs) have been identified as putative immune receptors. However, to date, there have been few analyses of LecRKs in crop plants. Virus-induced gene silencing of CaLecRK-S.5 verified the role of CaLecRK-S.5 in broad-spectrum resistance. Compared with control plants, CaLecRK-S.5-silenced plants showed reduced hypersensitive response, reactive oxygen species burst, secondary metabolite production, mitogen-activated protein kinase activation, and defense-related gene expression in response to Tobacco mosaic virus pathotype P0 (TMV-P0) infection. Suppression of CaLecRK-S.5 expression significantly enhanced the susceptibility to Pepper mild mottle virus pathotype P1,2,3, Xanthomonas campestris pv. vesicatoria, Phytophthora capsici, as well as TMV-P0. Additionally, β-aminobutyric acid treatment and a systemic acquired resistance assay revealed that CaLecRK-S.5 is involved in priming of plant immunity. Pre-treatment with β-aminobutyric acid before viral infection restored the reduced disease resistance phenotypes shown in CaLecRK-S.5-silenced plants. Systemic acquired resistance was also abolished in CaLecRK-S.5-silenced plants. Finally, RNA sequencing analysis indicated that CaLecRK-S.5 positively regulates plant immunity at the transcriptional level. Altogether, these results suggest that CaLecRK-S.5-mediated broad-spectrum resistance is associated with the regulation of priming. PMID:27647723

Quantitative analysis of receptor-mediated uptake and pro-apoptotic activity of mistletoe lectin-1 by high content imaging.

PubMed

Beztsinna, N; de Matos, M B C; Walther, J; Heyder, C; Hildebrandt, E; Leneweit, G; Mastrobattista, E; Kok, R J

2018-02-09

Ribosome inactivating proteins (RIPs) are highly potent cytotoxins that have potential as anticancer therapeutics. Mistletoe lectin 1 (ML1) is a heterodimeric cytotoxic protein isolated from European Mistletoe and belongs to RIP class II. The aim of this project was to systematically study ML1 cell binding, endocytosis pathway(s), subcellular processing and apoptosis activation. For this purpose, state of the art cell imaging equipment and automated image analysis algorithms were used. ML1 displayed very fast binding to sugar residues on the membrane and energy-dependent uptake in CT26 cells. The co-staining with specific antibodies and uptake blocking experiments revealed involvement of both clathrin-dependent and -independent pathways in ML1 endocytosis. Co-localization studies demonstrated the toxin transport from early endocytic vesicles to Golgi network; a retrograde road to the endoplasmic reticulum. The pro-apoptotic and antiproliferative activity of ML1 were shown in time lapse movies and subsequently quantified. ML1 cytotoxicity was less affected in multidrug resistant tumor cell line 4T1 in contrast to commonly used chemotherapeutic drug (ML1 resistance index 6.9 vs 13.4 for doxorubicin; IC 50 : ML1 1.4 ng/ml vs doxorubicin 24000 ng/ml). This opens new opportunities for the use of ML1 as an alternative treatment in multidrug resistant cancers.

Evaluation of Etest MBL for Detection of blaIMP-1 and blaVIM-2 Allele-Positive Clinical Isolates of Pseudomonas spp. and Acinetobacter spp.

PubMed Central

Lee, Kyungwon; Yong, Dongeun; Yum, Jong Hwa; Lim, Yong Sik; Bolmström, Anne; Qwärnström, Anette; Karlsson, Åsa; Chong, Yunsop

2005-01-01

The Etest MBL (AB BIODISK, Solna, Sweden) correctly differentiated all 57 isolates of Acinetobacter spp. and Pseudomonas aeruginosa with the blaIMP-1 allele and 135 of 137 (98.5%) Acinetobacter spp. and Pseudomonas spp. isolates with the blaVIM-2 allele. The Etest MBL was reliable for detecting the IMP-1- and VIM-2-producing Pseudomonas and Acinetobacter isolates. PMID:15695713

Rational design of adjuvants targeting the C-type lectin Mincle.

PubMed

Decout, Alexiane; Silva-Gomes, Sandro; Drocourt, Daniel; Barbe, Sophie; André, Isabelle; Cueto, Francisco J; Lioux, Thierry; Sancho, David; Pérouzel, Eric; Vercellone, Alain; Prandi, Jacques; Gilleron, Martine; Tiraby, Gérard; Nigou, Jérôme

2017-03-07

The advances in subunit vaccines development have intensified the search for potent adjuvants, particularly adjuvants inducing cell-mediated immune responses. Identification of the C-type lectin Mincle as one of the receptors underlying the remarkable immunogenicity of the mycobacterial cell wall, via recognition of trehalose-6,6'-dimycolate (TDM), has opened avenues for the rational design of such molecules. Using a combination of chemical synthesis, biological evaluation, molecular dynamics simulations, and protein mutagenesis, we gained insight into the molecular bases of glycolipid recognition by Mincle. Unexpectedly, the fine structure of the fatty acids was found to play a key role in the binding of a glycolipid to the carbohydrate recognition domain of the lectin. Glucose and mannose esterified at O -6 by a synthetic α-ramified 32-carbon fatty acid showed agonist activity similar to that of TDM, despite their much simpler structure. Moreover, they were seen to stimulate proinflammatory cytokine production in primary human and murine cells in a Mincle-dependent fashion. Finally, they were found to induce strong Th1 and Th17 immune responses in vivo in immunization experiments in mice and conferred protection in a murine model of Mycobacterium tuberculosis infection. Here we describe the rational development of new molecules with powerful adjuvant properties.

Intercomparisons of Marine Boundary Layer Cloud Properties from the ARM CAP-MBL Campaign and Two MODIS Cloud Products

NASA Technical Reports Server (NTRS)

Zhang, Zhibo; Dong, Xiquan; Xi, Baike; Song, Hua; Ma, Po-Lun; Ghan, Steven J.; Platnick, Steven; Minnis, Patrick

2017-01-01

From April 2009 to December 2010, the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) program carried out an observational field campaign on Graciosa Island, targeting the marine boundary layer (MBL) clouds over the Azores region. In this paper, we present an inter-comparison of the MBL cloud properties, namely, cloud liquid water path (LWP), cloud optical thickness (COT) and cloud-droplet effective radius (CER), among retrievals from the ARM mobile facility (AMF) and two Moderate Resolution Spectroradiometer (MODIS) cloud products (GSFC-MODIS and CERES-MODIS). A total of 63 daytime single-layer MBL cloud cases are selected for inter-comparison. Comparison of collocated retrievals indicates that the two MODIS cloud products agree well on both COT and CER retrievals, with the correlation coefficient R greater than 0.95 despite their significant difference in spatial sampling. In both MODIS products, the CER retrievals based on the 2.1 micrometers band (CER(sub 2.1)) is significantly smaller than that based on the 3.7 micrometers band (CER(sub 3.7)). The GSFC-MODIS cloud product is collocated and compared with ground-based ARM observations at several temporal spatial scales. In general, the correlation increases with more precise collocation. For the 63 selected MBL cloud cases, the GSFC-MODIS LWP and COT retrievals agree reasonably well with the ground-based observations with no apparent bias and correlation coefficient R around 0.85 and 0.70, respectively. However, GSFC-MODIS CER(sub 3.7) and CER(sub 2.1) retrievals have a lower correlation (R is approximately 0.5) with the ground-based retrievals. For the 63 selected cases, they are on average larger than ground observations by about 1.5 micrometers and 3.0 micrometers, respectively. Taking into account that the MODIS CER retrievals are only sensitive to cloud top reduces the bias only by 0.5 micrometers.

Intercomparisons of marine boundary layer cloud properties from the ARM CAP-MBL campaign and two MODIS cloud products

NASA Astrophysics Data System (ADS)

Zhang, Zhibo; Dong, Xiquan; Xi, Baike; Song, Hua; Ma, Po-Lun; Ghan, Steven J.; Platnick, Steven; Minnis, Patrick

2017-02-01

From April 2009 to December 2010, the Department of Energy Atmospheric Radiation Measurement (ARM) program carried out an observational field campaign on Graciosa Island, targeting the marine boundary layer (MBL) clouds over the Azores region. In this paper, we present an intercomparison of the MBL cloud properties, namely, cloud liquid water path (LWP), cloud optical thickness (COT), and cloud-droplet effective radius (CER), among retrievals from the ARM mobile facility and two Moderate Resolution Imaging Spectroradiometer (MODIS) cloud products (Goddard Space Flight Center (GSFC)-MODIS and Clouds and Earth's Radiant Energy System-MODIS). A total of 63 daytime single-layer MBL cloud cases are selected for intercomparison. Comparison of collocated retrievals indicates that the two MODIS cloud products agree well on both COT and CER retrievals, with the correlation coefficient R > 0.95, despite their significant difference in spatial sampling. In both MODIS products, the CER retrievals based on the 2.1 µm band (CER2.1) are significantly larger than those based on the 3.7 µm band (CER3.7). The GSFC-MODIS cloud product is collocated and compared with ground-based ARM observations at several temporal-spatial scales. In general, the correlation increases with more precise collocation. For the 63 selected MBL cloud cases, the GSFC-MODIS LWP and COT retrievals agree reasonably well with the ground-based observations with no apparent bias and correlation coefficient R around 0.85 and 0.70, respectively. However, GSFC-MODIS CER3.7 and CER2.1 retrievals have a lower correlation (R 0.5) with the ground-based retrievals. For the 63 selected cases, they are on average larger than ground observations by about 1.5 µm and 3.0 µm, respectively. Taking into account that the MODIS CER retrievals are only sensitive to cloud top reduces the bias only by 0.5 µm.

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.

Insights into animal and plant lectins with antimicrobial activities.

PubMed

Dias, Renata de Oliveira; Machado, Leandro Dos Santos; Migliolo, Ludovico; Franco, Octavio Luiz

2015-01-05

Lectins are multivalent proteins with the ability to recognize and bind diverse carbohydrate structures. The glyco -binding and diverse molecular structures observed in these protein classes make them a large and heterogeneous group with a wide range of biological activities in microorganisms, animals and plants. Lectins from plants and animals are commonly used in direct defense against pathogens and in immune regulation. This review focuses on sources of animal and plant lectins, describing their functional classification and tridimensional structures, relating these properties with biotechnological purposes, including antimicrobial activities. In summary, this work focuses on structural-functional elucidation of diverse lectin groups, shedding some light on host-pathogen interactions; it also examines their emergence as biotechnological tools through gene manipulation and development of new drugs.

Antibacterial activity of lactose-binding lectins from Bufo arenarum skin.

PubMed

Sánchez Riera, Alicia; Daud, Adriana; Gallo, Adriana; Genta, Susana; Aybar, Manuel; Sánchez, Sara

2003-04-01

Amphibians respond to microbial infection through cellular and humoral defense mechanisms such as antimicrobial protein secretion. Most humoral defense proteins are synthetized in the skin. In this study we isolated two beta-galactoside-binding lectins with molecular weights of 50 and 56 KDa from the skin of Bufo arenarum. These lectins have significant hemagglutination activity against trypsinized rabbit erythrocytes, which was inhibited by galactose-containing saccharides. They are water-soluble and independent of the presence of calcium. The antimicrobial analysis for each lectin was performed. At mumolar concentration lectins show strong bacteriostatic activity against Gram negative bacteria (Escherichia coli K12 4100 and wild strains of Escherichia coli and Proteus morganii) and Gram positive bacteria (Enterococcus faecalis). The antibacterial activity of these lectins may provide an effective defense against invading microbes in the amphibian Bufo arenarum.

Linear Precision Glycomacromolecules with Varying Interligand Spacing and Linker Functionalities Binding to Concanavalin A and the Bacterial Lectin FimH.

PubMed

Igde, Sinaida; Röblitz, Susanna; Müller, Anne; Kolbe, Katharina; Boden, Sophia; Fessele, Claudia; Lindhorst, Thisbe K; Weber, Marcus; Hartmann, Laura

2017-12-01

A series of precision glycomacromolecules is prepared following previously established solid phase synthesis allowing for controlled variations of interligand spacing and the overall number of carbohydrate ligands. In addition, now also different linkers are installed between the carbohydrate ligand and the macromolecular scaffold. The lectin binding behavior of these glycomacromolecules is then evaluated in isothermal titration calorimetry (ITC) and kinITC experiments using the lectin Concanavalin A (Con A) in its dimeric and tetrameric form. The results indicate that both sterical and statistical effects impact lectin binding of precision glycomacromolecules. Moreover, ITC results show that highest affinity toward Con A can be achieved with an ethyl phenyl linker, which parallels earlier findings with the bacterial lectin FimH. In this way, a first set of glycomacromolecule structures is selected for testing in a bacterial adhesion-inhibition study. Here, the findings point to a one-sugar binding mode mainly affected by sterical restraints of the nonbinding parts of the respective glycomacromolecule. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Isolation and characterization of a cyanobacterium-binding protein and its cell wall receptor in the lichen Peltigera canina

PubMed Central

Díaz, Eva-María; Sacristán, Mara; Legaz, María-Estrella

2009-01-01

Peltigera canina, a cyanolichen containing Nostoc as cyanobiont, produces and secretes arginase to a medium containing arginine. Secreted arginase acts as a lectin by binding to the surface of Nostoc cells through a specific receptor which develops urease activity. The enzyme urease has been located in the cell wall of recently isolated cyanobionts. Cytochemical detection of urease is achieved by producing a black, electron-dense precipitate of cobalt sulfide proceeding from CO2 evolved from urea hydrolysis in the presence of cobalt chloride. This urease has been pre-purified by affinity chromatography on a bead of active agarose to which arginase was attached. Urease was eluted from the beads by 50 mM α-D-galactose. The experimentally probed fact that a fungal lectin developing subsidiary arginase activity acts as a recognition factor of compatible algal cells in chlorolichens can now been expanded to cyanolichens. PMID:19820309

Bauhinia variegata var. variegata lectin: isolation, characterization, and comparison.

PubMed

Chan, Yau Sang; Ng, Tzi Bun

2015-01-01

Bauhinia variegata var. variegata seeds are rich in proteins. Previously, one of the major storage proteins of the seeds was found to be a trypsin inhibitor that possessed various biological activities. By using another purification protocol, a glucoside- and galactoside-binding lectin that demonstrated some differences from the previously reported B. variegata lectin could be isolated from the seeds. It involved affinity chromatography on Affi-gel blue gel, ion exchange chromatography on Q-Sepharose and Mono Q, and also size exclusion chromatography on Superdex 75. The lectin was not retained on Affi-gel blue gel but interacted with Q-Sepharose. The lectin was a 64-kDa protein with two 32-kDa subunits. It had low thermostability (stable up to 50 °C) and moderate pH stability (stable in pH 3-10). It exhibited anti-proliferative activity on nasopharyngeal carcinoma HONE1 cells with an IC50 of 12.8 μM after treatment for 48 h. It also slightly inhibited the growth of hepatoma HepG2 cells. The lectin may have potential in aiding cancer treatments.

A Lectin-Like Receptor is Involved in Invasion of Erythrocytes by Plasmodium falciparum

NASA Astrophysics Data System (ADS)

Jungery, M.; Pasvol, G.; Newbold, C. I.; Weatherall, D. J.

1983-02-01

Glycophorin both in solution and inserted into liposomes blocks invasion of erythrocytes by the malaria parasite Plasmodium falciparum. Furthermore, one sugar, N-acetyl-D-glucosamine (GlcNAc), completely blocks invasion of the erythrocyte by this parasite. GlcNAc coupled to bovine serum albumin to prevent the sugar entering infected erythrocytes was at least 100,000 times more effective than GlcNAc alone. Bovine serum albumin coupled to lactose or bovine serum albumin alone had no effect on invasion. These results suggest that the binding of P. falciparum to erythrocytes is lectin-like and is determined by carbohydrates on glycophorin.

Novel lectin-modified poly(ethylene-co-vinyl acetate) mucoadhesive nanoparticles of carvedilol: preparation and in vitro optimization using a two-level factorial design.

PubMed

Varshosaz, Jaleh; Moazen, Ellaheh

2014-08-01

Carvedilol used in cardiovascular diseases has systemic bioavailability of 25-35%. The objective of this study was production of lectin-modified poly(ethylene-co-vinyl acetate) (PEVA) as mucoadhesive nanoparticles to enhance low oral bioavailability of carvedilol. Nanoparticles were prepared by the emulsification-solvent evaporation method using a two-level factorial design. The studied variables included the vinyl acetate content of the polymer, drug and polymer content. Surface modification of PEVA nanoparticles with lectin was carried out by the adsorption method and coupling efficiency was determined using the Bradford assay. Mucoadhesion of nanoparticles was studied on mucin. The particle size, polydispersity index, zeta potential, drug loading and drug release from nanoparticles were studied. The morphology of nanoparticles and crystalline status of the entrapped drug were studied by SEM, DSC and XRD tests, respectively. Results showed the most effective factor on particle size and zeta potential was the interaction of polymer and drug content while, drug loading efficiency and mucoadhesion were more affected by the interaction of polymer type and drug content. Drug concentration was the most effective variable on the drug release rate. The drug was in amorphous state in nanoparticles. The optimum nanoparticles obtained by 45 mg of copolymer contained 12% vinyl acetate/4.3 ml of organic phase and drug concentration of 37.5 wt% of polymer.

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 μM, and inhibited the activity of HIV-1 reverse transcriptase with an IC50 of 7.6 μM. 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

High-Throughput Lectin Microarray-Based Analysis of Live Cell Surface Glycosylation

PubMed Central

Li, Yu; Tao, Sheng-ce; Zhu, Heng; Schneck, Jonathan P.

2011-01-01

Lectins, plant-derived glycan-binding proteins, have long been used to detect glycans on cell surfaces. However, the techniques used to characterize serum or cells have largely been limited to mass spectrometry, blots, flow cytometry, and immunohistochemistry. While these lectin-based approaches are well established and they can discriminate a limited number of sugar isomers by concurrently using a limited number of lectins, they are not amenable for adaptation to a high-throughput platform. Fortunately, given the commercial availability of lectins with a variety of glycan specificities, lectins can be printed on a glass substrate in a microarray format to profile accessible cell-surface glycans. This method is an inviting alternative for analysis of a broad range of glycans in a high-throughput fashion and has been demonstrated to be a feasible method of identifying binding-accessible cell surface glycosylation on living cells. The current unit presents a lectin-based microarray approach for analyzing cell surface glycosylation in a high-throughput fashion. PMID:21400689

Trofile HIV co-receptor usage assay.

PubMed

Low, Andrew J; McGovern, Rachel A; Harrigan, P Richard

2009-03-01

The introduction of CCR5 antagonists increases the options available for constructing therapeutic drug regimens for HIV-positive patients. However, as these drugs do not inhibit HIV variants that use the CXCR4 co-receptor, a pretreatment test is required to determine accurately HIV co-receptor usage (tropism) before initiating CCR5 antagonist-based therapy. To discuss the Monogram Trofile assay as a diagnostic tool for determining HIV tropism by critically reviewing reported literature and available data. Monogram Trofile has become, largely by default, the de facto standard for HIV tropism assay. However, there is significant room for improvement in the speed, cost and availability of the test. Furthermore, the test is not quantitative, requires high-input HIV RNA viral loads, and produces results that are less biologically stable than expected. These technical considerations may limit the use of CCR5 antagonists in therapy. Nevertheless, this test is likely to remain the most widely used tropism diagnostic for the short term. We expect that a more practical and possibly more accurate method for measuring HIV tropism can be developed.

INTERACTION BETWEEN DELTA OPIOID RECEPTORS AND BENZODIAZEPINES IN CO2- INDUCED RESPIRATORY RESPONSES IN MICE

PubMed Central

Borkowski, Anne H.; Barnes, Dylan C.; Blanchette, Derek R.; Castellanos, F. Xavier; Klein, Donald F.; Wilson, Donald A.

2011-01-01

The false-suffocation hypothesis of panic disorder (Klein, 1993) suggested δ-opioid receptors as a possible source of the respiratory dysfunction manifested in panic attacks occurring in panic disorder (Preter and Klein, 2008). This study sought to determine if a lack of δ-opioid receptors in a mouse model affects respiratory response to elevated CO2, and whether the response is modulated by benzodiazepines, which are widely used to treat panic disorder. In a whole-body plethysmograph, respiratory responses to 5% CO2 were compared between δ-opioid receptor knockout mice and wild-type mice after saline, diazepam (1 mg/kg), and alprazolam (0.3 mg/kg) injection. The results show that lack of δ-opioid receptors does not affect normal response to elevated CO2, but does prevent benzodiazepines from modulating that response. Thus, in the presence of benzodiazepine agonists, respiratory responses to elevated CO2 were enhanced in δ-opioid receptor knockout mice compared to wild-type mice. This suggests an interplay between benzodiazepine receptors and δ-opioid receptors in regulating the respiratory effects of elevated CO2, which might be related to CO2 induced panic. PMID:21561601

Lectin-based food poisoning: a new mechanism of protein toxicity.

PubMed

Miyake, Katsuya; Tanaka, Toru; McNeil, Paul L

2007-08-01

Ingestion of the lectins present in certain improperly cooked vegetables can result in acute GI tract distress, but the mechanism of toxicity is unknown. In vivo, gut epithelial cells are constantly exposed to mechanical and other stresses and consequently individual cells frequently experience plasma membrane disruptions. Repair of these cell surface disruptions allows the wounded cell to survive: failure results in necrotic cell death. Plasma membrane repair is mediated, in part, by an exocytotic event that adds a patch of internal membrane to the defect site. Lectins are known to inhibit exocytosis. We therefore tested the novel hypothesis that lectin toxicity is due to an inhibitory effect on plasma membrane repair. Repair of plasma membrane disruptions and exocytosis of mucus was assessed after treatment of cultured cell models and excised segments of the GI tract with lectins. Plasma membrane disruptions were produced by focal irradiation of individual cells, using a microscope-based laser, or by mechanical abrasion of multiple cells, using a syringe needle. Repair was then assessed by monitoring the cytosolic penetration of dyes incapable of crossing the intact plasma membrane. We found that cell surface-bound lectins potently inhibited plasma membrane repair, and the exocytosis of mucus that normally accompanies the repair response. Lectins potently inhibit plasma membrane repair, and hence are toxic to wounded cells. This represents a novel form of protein-based toxicity, one that, we propose, is the basis of plant lectin food poisoning.

Unfolding energetics and stability of banana lectin.

PubMed

Gupta, Garima; Sinha, Sharmistha; Surolia, Avadhesha

2008-08-01

The unfolding pathway of banana lectin from Musa paradisiaca was determined by isothermal denaturation induced by the chaotrope GdnCl. The unfolding was found to be a reversible process. The data obtained by isothermal denaturation provided information on conformational stability of banana lectin. The high values of DeltaG of unfolding at various temperatures indicated the strength of intersubunit interactions. It was found that banana lectin is a very stable and denatures at high chaotrope concentrations only. The basis of the stability may be attributed to strong hydrogen bonds of the order 2.5-3.1 A at the dimeric interface along with the presence of water bridges. This is perhaps very unique example in proteins where subunit association is not a consequence of the predominance of hydrophobic interactions. (c) 2008 Wiley-Liss, Inc.

The Distribution of Lectins across the Phylum Nematoda: A Genome-Wide Search

PubMed Central

Bauters, Lander; Naalden, Diana; Gheysen, Godelieve

2017-01-01

Nematodes are a very diverse phylum that has adapted to nearly every ecosystem. They have developed specialized lifestyles, dividing the phylum into free-living, animal, and plant parasitic species. Their sheer abundance in numbers and presence in nearly every ecosystem make them the most prevalent animals on earth. In this research nematode-specific profiles were designed to retrieve predicted lectin-like domains from the sequence data of nematode genomes and transcriptomes. Lectins are carbohydrate-binding proteins that play numerous roles inside and outside the cell depending on their sugar specificity and associated protein domains. The sugar-binding properties of the retrieved lectin-like proteins were predicted in silico. Although most research has focused on C-type lectin-like, galectin-like, and calreticulin-like proteins in nematodes, we show that the lectin-like repertoire in nematodes is far more diverse. We focused on C-type lectins, which are abundantly present in all investigated nematode species, but seem to be far more abundant in free-living species. Although C-type lectin-like proteins are omnipresent in nematodes, we have shown that only a small part possesses the residues that are thought to be essential for carbohydrate binding. Curiously, hevein, a typical plant lectin domain not reported in animals before, was found in some nematode species. PMID:28054982

The Distribution of Lectins across the Phylum Nematoda: A Genome-Wide Search.

PubMed

Bauters, Lander; Naalden, Diana; Gheysen, Godelieve

2017-01-04

Nematodes are a very diverse phylum that has adapted to nearly every ecosystem. They have developed specialized lifestyles, dividing the phylum into free-living, animal, and plant parasitic species. Their sheer abundance in numbers and presence in nearly every ecosystem make them the most prevalent animals on earth. In this research nematode-specific profiles were designed to retrieve predicted lectin-like domains from the sequence data of nematode genomes and transcriptomes. Lectins are carbohydrate-binding proteins that play numerous roles inside and outside the cell depending on their sugar specificity and associated protein domains. The sugar-binding properties of the retrieved lectin-like proteins were predicted in silico. Although most research has focused on C-type lectin-like, galectin-like, and calreticulin-like proteins in nematodes, we show that the lectin-like repertoire in nematodes is far more diverse. We focused on C-type lectins, which are abundantly present in all investigated nematode species, but seem to be far more abundant in free-living species. Although C-type lectin-like proteins are omnipresent in nematodes, we have shown that only a small part possesses the residues that are thought to be essential for carbohydrate binding. Curiously, hevein, a typical plant lectin domain not reported in animals before, was found in some nematode species.

Enzyme replacement for GM1-gangliosidosis: Uptake, lysosomal activation, and cellular disease correction using a novel β-galactosidase:RTB lectin fusion.

PubMed

Condori, Jose; Acosta, Walter; Ayala, Jorge; Katta, Varun; Flory, Ashley; Martin, Reid; Radin, Jonathan; Cramer, Carole L; Radin, David N

2016-02-01

New enzyme delivery technologies are required for treatment of lysosomal storage disorders with significant pathologies associated with the so-called "hard-to-treat" tissues and organs. Genetic deficiencies in the GLB1 gene encoding acid β-galactosidase lead to GM1-gangliosidosis or Morquio B, lysosomal diseases with predominant disease manifestation associated with the central nervous system or skeletal system, respectively. Current lysosomal ERTs are delivered into cells based on receptor-mediated endocytosis and do not effectively address several hard-to-treat organs including those critical for GM1-gangliosidosis patients. Lectins provide alternative cell-uptake mechanisms based on adsorptive-mediated endocytosis and thus may provide unique biodistribution for lysosomal disease therapeutics. In the current study, genetic fusions of the plant galactose/galactosamine-binding lectin, RTB, and the human acid β-galactosidase enzyme were produced using a plant-based bioproduction platform. β-gal:RTB and RTB:β-gal fusion products retained both lectin activity and β-galactosidase activity. Purified proteins representing both fusion orientations were efficiently taken up into GM1 patient fibroblasts and mediated the reduction of GM1 ganglioside substrate with activities matching mammalian cell-derived β-galactosidase. In contrast, plant-derived β-gal alone was enzymatically active but did not mediate uptake or correction indicating the need for either lectin-based (plant product) or mannose-6-phosphate-based (mammalian product) delivery. Native β-galactosidase undergoes catalytic activation (cleavage within the C-terminal region) in lysosomes and is stabilized by association with protective protein/cathepsin A. Enzymatic activity and lysosomal protein processing of the RTB fusions were assessed following internalization into GM1 fibroblasts. Within 1-4h, both β-gal:RTB and RTB:β-gal were processed to the ~64kDa "activated" β-gal form; the RTB lectin was

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-α) 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

Plant lectins: the ties that bind in root symbiosis and plant defense.

PubMed

De Hoff, Peter L; Brill, Laurence M; Hirsch, Ann M

2009-07-01

Lectins are a diverse group of carbohydrate-binding proteins that are found within and associated with organisms from all kingdoms of life. Several different classes of plant lectins serve a diverse array of functions. The most prominent of these include participation in plant defense against predators and pathogens and involvement in symbiotic interactions between host plants and symbiotic microbes, including mycorrhizal fungi and nitrogen-fixing rhizobia. Extensive biological, biochemical, and molecular studies have shed light on the functions of plant lectins, and a plethora of uncharacterized lectin genes are being revealed at the genomic scale, suggesting unexplored and novel diversity in plant lectin structure and function. Integration of the results from these different types of research is beginning to yield a more detailed understanding of the function of lectins in symbiosis, defense, and plant biology in general.

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.

Clustering of adhesion receptors following exposure of insect blood cells to foreign surfaces.

PubMed

Nardi, James B; Zhuang, Shufei; Pilas, Barbara; Bee, Charles Mark; Kanost, Michael R

2005-05-01

Cell-mediated immune responses of insects involve interactions of two main classes of blood cells (hemocytes) known as granular cells and plasmatocytes. In response to a foreign surface, these hemocytes suddenly transform from circulating, non-adherent cells to cells that interact and adhere to each other and the foreign surface. This report presents evidence that during this adhesive transformation the extracellular matrix (ECM) proteins lacunin and a ligand for peanut agglutinin (PNA) lectin are released by granular cells and bind to surfaces of both granular cells and plasmatocytes. ECM protein co-localizes on cell surfaces with the adhesive receptors integrin and neuroglian, a member of the immunoglobulin superfamily. The ECM protein(s) secreted by granular cells are hypothesized to interact with adhesion receptors such as neuroglian and integrin by cross linking and clustering them on hemocyte surfaces. This clustering of receptors is known to enhance the adhesiveness (avidity) of interacting mammalian immune cells. The formation of ring-shaped clusters of these adhesion receptors on surfaces of insect immune cells represents an evolutionary antecedent of the mammalian immunological synapse.

Investigating Chemistry Students' Learning about the Relationship between the Temperature and the Pressure of a Gas Using a Microcomputer-Based Laboratory (MBL): A Word of Caution.

ERIC Educational Resources Information Center

Thomas, Gregory P.; McRobbie, Campbell J.

2002-01-01

Focuses on practices related to the use of a microcomputer-based laboratory (MBL) in a high school chemistry course in which students studied gases and kinetic theory. Reports that little or no higher order thinking was employed as students engaged in using the MBL and that some alternative conceptions were still evident. (Contains 42 references.)…

A scallop C-type lectin from Argopecten irradians (AiCTL5) with activities of lipopolysaccharide binding and Gram-negative bacteria agglutination.

PubMed

Mu, Changkao; Song, Xiaoyan; Zhao, Jianmin; Wang, Lingling; Qiu, Limei; Zhang, Huan; Zhou, Zhi; Wang, Mengqiang; Song, Linsheng; Wang, Chunlin

2012-05-01

C-type lectins are a family of calcium-dependent carbohydrate-binding proteins. In the present study, a C-type lectin (designated as AiCTL5) was identified and characterized from Argopecten irradians. The full-length cDNA of AiCTL5 was of 673 bp, containing a 5' untranslated region (UTR) of 24 bp, a 3' UTR of 130 bp with a poly (A) tail, and an open reading frame (ORF) of 519 bp encoding a polypeptide of 172 amino acids with a putative signal peptide of 17 amino acids. A C-type lectin-like domain (CRD) containing 6 conserved cysteines and a putative glycosylation sites were identified in the deduced amino acid sequence of AiCTL5. AiCTL5 shared 11%-27.5% identity with the previous reported C-type lectin from A. irradians. The cDNA fragment encoding the mature peptide of AiCTL5 was recombined into pET-21a (+) with a C-terminal hexa-histidine tag fused in-frame, and expressed in Escherichia coli Origami (DE3). The recombinant AiCTL5 (rAiCTL5) agglutinated Gram-negative E. coli TOP10F' and Listonella anguillarum, but did not agglutinate Gram-positive bacteria Bacillus thuringiensis and Micrococcus luteus, and the agglutination could be inhibited by EDTA, indicating that AiCTL5 was a Ca(2+)-dependent lectin. rAiCTL5 exhibited a significantly strong activity to bind LPS from E. coli, which conformed to the agglutinating activity toward Gram-negative bacteria. Moreover, rAiCTL5 also agglutinated rabbit erythrocytes. These results indicated that AiCTL5 could function as a pattern recognition receptor to protect bay scallop from Gram-negative bacterial infection, and also provide evidence to understand the structural and functional diverse of lectin. Copyright © 2012 Elsevier Ltd. All rights reserved.

The gene for stinging nettle lectin (Urtica dioica agglutinin) encodes both a lectin and a chitinase.

PubMed

Lerner, D R; Raikhel, N V

1992-06-05

Chitin-binding proteins are present in a wide range of plant species, including both monocots and dicots, even though these plants contain no chitin. To investigate the relationship between in vitro antifungal and insecticidal activities of chitin-binding proteins and their unknown endogenous functions, the stinging nettle lectin (Urtica dioica agglutinin, UDA) cDNA was cloned using a synthetic gene as the probe. The nettle lectin cDNA clone contained an open reading frame encoding 374 amino acids. Analysis of the deduced amino acid sequence revealed a 21-amino acid putative signal sequence and the 86 amino acids encoding the two chitin-binding domains of nettle lectin. These domains were fused to a 19-amino acid "spacer" domain and a 244-amino acid carboxyl extension with partial identity to a chitinase catalytic domain. The authenticity of the cDNA clone was confirmed by deduced amino acid sequence identity with sequence data obtained from tryptic digests, RNA gel blot, and polymerase chain reaction analyses. RNA gel blot analysis also showed the nettle lectin message was present primarily in rhizomes and inflorescence (with immature seeds) but not in leaves or stems. Chitinase enzymatic activity was found when the chitinase-like domain alone or the chitinase-like domain with the chitin-binding domains were expressed in Escherichia coli. This is the first example of a chitin-binding protein with both a duplication of the 43-amino acid chitin-binding domain and a fusion of the chitin-binding domains to a structurally unrelated domain, the chitinase domain.

Radiolabeled Peptide Scaffolds for PET/SPECT - Optical in Vivo Imaging of Carbohydrate-Lectin Interactions

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

Deutscher, Susan

2014-09-30

The objective of this research is to develop phage display-selected peptides into radio- and fluoresecently- labeled scaffolds for the multimodal imaging of carbohydrate-lectin interactions. While numerous protein and receptor systems are being explored for the development of targeted imaging agents, the targeting and analysis of carbohydrate-lectin complexes in vivo remains relatively unexplored. Antibodies, nanoparticles, and peptides are being developed that target carbohydrate-lectin complexes in living systems. However, antibodies and nanoparticles often suffer from slow clearance and toxicity problems. Peptides are attractive alternative vehicles for the specific delivery of radionuclides or fluorophores to sites of interest in vivo, although, because ofmore » their size, uptake and retention may be less than antibodies. We have selected high affinity peptides that bind a specific carbohydrate-lectin complex involved in cell-cell adhesion and cross-linking using bacteriophage (phage) display technologies (1,2). These peptides have allowed us to probe the role of these antigens in cell adhesion. Fluorescent versions of the peptides have been developed for optical imaging and radiolabeled versions have been used in single photon emission computed tomography (SPECT) and positron emission tomography (PET) in vivo imaging (3-6). A benefit in employing the radiolabeled peptides in SPECT and PET is that these imaging modalities are widely used in living systems and offer deep tissue sensitivity. Radiolabeled peptides, however, often exhibit poor stability and high kidney uptake in vivo. Conversely, optical imaging is sensitive and offers good spatial resolution, but is not useful for deep tissue penetration and is semi-quantitative. Thus, multimodality imaging that relies on the strengths of both radio- and optical- imaging is a current focus for development of new in vivo imaging agents. We propose a novel means to improve the efficacy of radiolabeled and

Unique, polyfucosylated glycan-receptor interactions are essential for regeneration of Hydra magnipapillata.

PubMed

Sahadevan, Sonu; Antonopoulos, Aristotelis; Haslam, Stuart M; Dell, Anne; Ramaswamy, Subramanian; Babu, Ponnusamy

2014-01-17

Cell-cell communications, cell-matrix interactions, and cell migrations play a major role in regeneration. However, little is known about the molecular players involved in these critical events, especially cell surface molecules. Here, we demonstrate the role of specific glycan-receptor interactions in the regenerative process using Hydra magnipapillata as a model system. Global characterization of the N- and O-glycans expressed by H. magnipapillata using ultrasensitive mass spectrometry revealed mainly polyfucosylated LacdiNAc antennary structures. Affinity purification showed that a putative C-type lectin (accession number Q6SIX6) is a likely endogenous receptor for the novel polyfucosylated glycans. Disruption of glycan-receptor interactions led to complete shutdown of the regeneration machinery in live Hydra. A time-dependent, lack-of-regeneration phenotype observed upon incubation with exogenous fuco-lectins suggests the involvement of a polyfucose receptor-mediated signaling mechanism during regeneration. Thus, for the first time, the results presented here provide direct evidence for the role of polyfucosylated glycan-receptor interactions in the regeneration of H. magnipapillata.

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. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Electronic Detection of Lectins Using Carbohydrate Functionalized Nanostructures: Graphene versus Carbon Nanotubes

PubMed Central

Chen, Yanan; Vedala, Harindra; Kotchey, Gregg P.; Audfray, Aymeric; Cecioni, Samy; Imberty, Anne; Vidal, Sébastien; Star, Alexander

2012-01-01

Here we investigated the interactions between lectins and carbohydrates using field-effect transistor (FET) devices comprised of chemically converted graphene (CCG) and single-walled carbon nanotubes (SWNTs). Pyrene- and porphyrin-based glycoconjugates were functionalized noncovalently on the surface of CCG-FET and SWNT-FET devices, which were then treated with 2 µM of nonspecific and specific lectins. In particular, three different lectins (PA-IL, PA-IIL and ConA) and three carbohydrate epitopes (galactose, fucose and mannose) were tested. The responses of 36 different devices were compared and rationalized using computer-aided models of carbon nanostructure/glycoconjugate interactions. Glycoconjugates surface coverage in addition to one-dimensional structures of SWNTs resulted in optimal lectin detection. Additionally, lectin titration data of SWNT- and CCG-based biosensors were used to calculate lectin dissociation constants (Kd) and compare them to the values obtained from the isothermal titration microcalorimetry (ITC) technique. PMID:22136380

Deterrent activity of plant lectins on cowpea weevil Callosobruchus maculatus (F.) oviposition.

PubMed

Sadeghi, Amin; Van Damme, Els J M; Peumans, Willy J; Smagghe, Guy

2006-09-01

A set of 14 plant lectins was screened in a binary choice bioassay for inhibitory activity on cowpea weevil Callosobruchus maculatus (F.) oviposition. Coating of chickpea seeds (Cicer arietinum L.) with a 0.05% (w/v) solution of plant lectins caused a significant reduction in egg laying. Control experiments with heat inactivated lectin and BSA indicated that the observed deterrent effects are specific and require carbohydrate-binding activity. However, no clear correlation could be established between deterrent activity and sugar-binding specificity/molecular structure of the lectins. Increasing the insect density reduced the inhibitory effect of the lectins confirming that female insects are capable of adjusting their oviposition rates as a function of host availability.

Association of the Risk of Dental Caries and Polymorphism of MBL2 rs11003125 Gene in Iranian Adults.

PubMed

Mokhtari, Mohammad Javad; Koohpeima, Fatemeh; Hashemi-Gorji, Feyzollah

2018-06-14

This case-control study aimed to investigate the effect of rs11003125 in dental caries. For this purpose, a total number of 404 individuals - from Fars Province in Iran - were studied. The technique of this research was the tetra-primer amplification-refractory mutation system (ARMS)-PCR. Dental caries prevalence among the 404 individuals was assessed by counting the number of decayed, missing, and filled teeth. In this research, individuals were divided into two groups: cases (n = 238) and controls (n = 166), and the peripheral blood samples were used to extract the genomic DNA. For genotyping of DNA, the tetra-primer ARMS-PCR method was conducted using specific primer pairs. While examining MBL2 rs11003125 polymorphism, we found significant differences in the genotype frequencies between the case and the control group. The pooled estimates indicated that the GG and GC genotypes of MBL2 rs11003125 polymorphism significantly increased, and therefore caries risk (OR = 2.40, 95% CI = 1.31-4.40, p = 0.004) under the dominant model. These findings suggested that polymorphism in MBL2 gene was associated with dental caries in Iranian adults. Further verification is needed with more ethnic groups and larger sample sizes to determine whether rs11003125 polymorphism is related to dental caries in other regions or not. © 2018 S. Karger AG, Basel.

Partial functional redundancy of MreB isoforms, MreB, Mbl and MreBH, in cell morphogenesis of Bacillus subtilis.

PubMed

Kawai, Yoshikazu; Asai, Kei; Errington, Jeffery

2009-08-01

MreB proteins are bacterial actin homologues thought to have a role in cell shape determination by positioning the cell wall synthetic machinery. Many bacteria, particularly Gram-positives, have more than one MreB isoform. Bacillus subtilis has three, MreB, Mbl and MreBH, which colocalize in a single helical structure. We now show that the helical pattern of peptidoglycan (PG) synthesis in the cylindrical part of the rod-shaped cell is governed by the redundant action of the three MreB isoforms. Single mutants for any one of mreB isoforms can still incorporate PG in a helical pattern and generate a rod shape. However, after depletion of MreB in an mbl mutant (or depletion of all three isoforms) lateral wall PG synthesis was impaired and the cells became spherical and lytic. Overexpression of any one of the MreB isoforms overcame the lethality as well as the defects in lateral PG synthesis and cell shape. Furthermore, MreB and Mbl can associate with the peptidoglycan biosynthetic machinery independently. However, no single MreB isoform was able to support normal growth under various stress conditions, suggesting that the multiple isoforms are used to allow cells to maintain proper growth and morphogenesis under changing and sometimes adverse conditions.

Rachycentron canadum (cobia) lectin promoted mitogenic response in mice BALB/c splenocytes.

PubMed

Coriolano, M C; de Melo, C M L; Santos, A J G; Pereira, V R A; Coelho, L C B B

2012-12-01

The mitogenic lectins are invaluable tools to study the biochemical changes associated with lymphocyte activation and proliferation of various immune cells. Rachycentron canadum lectin (RcaL) was detected and purified from serum of cobia fish. The aim of this study was to evaluate the proliferative response and cytokine production in splenocytes of mice in vitro stimulated with RcaL lectin; Canavalia ensiformis lectin (Con A) was used as positive control. A high proliferation index was induced by RcaL in relation to control cells. Furthermore, RcaL induced higher IL-2 and IL-6 production in relation to control. The cell viability was 90% in splenocytes treated with RcaL lectin, but RcaL promoted significant late apoptosis after 24 and 48 h in relation to control. RcaL induced proliferative responses suggesting that this lectin can be used as a mitogenic agent in immunostimulatory assays. © 2012 The Authors. Scandinavian Journal of Immunology © 2012 Blackwell Publishing Ltd.

Protozoa lectins and their role in host-pathogen interactions.

PubMed

Singh, Ram Sarup; Walia, Amandeep Kaur; Kanwar, Jagat Rakesh

2016-01-01

Lectins are proteins/glycoproteins of non-immune origin that agglutinate red blood cells, lymphocytes, fibroblasts, etc., and bind reversibly to carbohydrates present on the apposing cells. They have at least two carbohydrate binding sites and their binding can be inhibited by one or more carbohydrates. Owing to carbohydrate binding specificity of lectins, they mediate cell-cell interactions and play role in protozoan adhesion and host cell cytotoxicity, thus are central to the pathogenic property of the parasite. Several parasitic protozoa possess lectins which mediate parasite adherence to host cells based on their carbohydrate specificities. These interactions could be exploited for development of novel therapeutics, targeting the adherence and thus helpful in eradicating wide spread of protozoan diseases. The current review highlights the present state knowledge with regard to protozoal lectins with an emphasis on their haemagglutination activity, carbohydrate specificity, characteristics and also their role in pathogenesis notably as adhesion molecules, thereby aiding the pathogen in disease establishment. Copyright © 2016 Elsevier Inc. All rights reserved.

Characterization of β-Glucan Recognition Site on C-Type Lectin, Dectin 1

PubMed Central

Adachi, Yoshiyuki; Ishii, Takashi; Ikeda, Yoshihiko; Hoshino, Akiyoshi; Tamura, Hiroshi; Aketagawa, Jun; Tanaka, Shigenori; Ohno, Naohito

2004-01-01

Dectin 1 is a mammalian cell surface receptor for (1→3)-β-d-glucans. Since (1→3)-β-d-glucans are commonly present on fungal cell walls, it has been suggested that dectin 1 is important for recognizing fungal invasion. In this study we tried to deduce the amino acid residues in dectin 1 responsible for β-glucan recognition. HEK293 cells transfected with mouse dectin 1 cDNA could bind to a gel-forming (1→3)-β-d-glucan, schizophyllan (SPG). The binding of SPG to a dectin 1 transfectant was inhibited by pretreatment with other β-glucans having a (1→3)-β-d-glucosyl linkage but not by pretreatment with α-glucans. Dectin 1 has a carbohydrate recognition domain (CRD) consisting of six cysteine residues that are highly conserved in C-type lectins. We prepared 32 point mutants with mutations in the CRD and analyzed their binding to SPG. Mutations at Trp221 and His223 resulted in decreased binding to β-glucan. Monoclonal antibody 4B2, a dectin- 1 monoclonal antibody which had a blocking effect on the β-glucan interaction, completely failed to bind the dectin-1 mutant W221A. A mutant with mutations in Trp221 and His223 did not have a collaborative effect on Toll-like receptor 2-mediated cellular activation in response to zymosan. These amino acid residues are distinct from residues in other sugar-recognizing peptide sequences of typical C-type lectins. These results suggest that the amino acid sequence W221-I222-H223 is critical for formation of a β-glucan binding site in the CRD of dectin 1. PMID:15213161

Lectin from embryos and oocytes of Xenopus laevis. Purification and properties.

PubMed

Roberson, M M; Barondes, S H

1982-07-10

Soluble extracts of Xenopus laevis blastula stage embryos, oocytes, and adult liver contain lectin activities detected by agglutination of trypsinized, glutaraldehyde-fixed rabbit erythrocytes. Lectin from the embryos and oocytes was purified by affinity chromatography on a column derivatized with melibiose. Trace contaminants were removed either by preparative isoelectric focusing or by gel filtration. Based on its behavior on Sepharose 6B the purified oocyte lectin has an apparent molecular weight of approximately 480,000. On sodium dodecyl sulfate polyacrylamide gel electrophoresis under reducing conditions there were two major bands with molecular weight ranges of about 43,000 and 45,000, with diffuse trails. Since the purified lectin contains about 20% saccharides by weight and since both bands are glycosylated, diffuseness might be due to variable glycosylation. Heterogeneity was indicated by isoelectric focusing in polyacrylamide gels, which showed four protein bands with isoelectric points ranging from 4.4 to 4.9. Lectins from both embryos and oocytes comprised about 1 to 2% of the total soluble protein and could not be distinguished by sodium dodecyl sulfate polyacrylamide gel electrophoresis. However, the specific hemagglutination activity of the purified oocyte lectin was, on the average, 7-fold higher. Levels in crude extracts of liver were 3 orders of magnitude lower than those from oocytes. The hemagglutination activities of the lectins from embryos, oocytes, and adult liver required Ca2+ and were blocked by similar concentrations of both alpha- and beta-galactosides.

Lag-3, Tim-3, and TIGIT co-inhibitory receptors with specialized functions in immune regulation

PubMed Central

Anderson, Ana C.; Joller, Nicole; Kuchroo, Vijay K.

2016-01-01

Summary Co-inhibitory receptors, such as CTLA-4 and PD-1, have an important role in regulating T cell responses and have proven to be effective targets in the setting of chronic diseases where constitutive co-inhibitory receptor expression on T cells dampens effector T cell responses. Unfortunately, many patients still fail to respond to therapies that target CTLA-4 and PD-1. The next wave of co-inhibitory receptor targets that are being explored in clinical trials include Lag-3, Tim-3, and TIGIT. These receptors while belonging to the same class of receptors as PD-1 and CTLA-4 exhibit unique functions especially at tissue sites where they regulate distinct aspects of immunity. Increased understanding of the specialized functions of these receptors will inform the rational application of therapies that target these receptors to the clinic. PMID:27192565

Cryo-EM structures of MERS-CoV and SARS-CoV spike glycoproteins reveal the dynamic receptor binding domains.

PubMed

Yuan, Yuan; Cao, Duanfang; Zhang, Yanfang; Ma, Jun; Qi, Jianxun; Wang, Qihui; Lu, Guangwen; Wu, Ying; Yan, Jinghua; Shi, Yi; Zhang, Xinzheng; Gao, George F

2017-04-10

The envelope spike (S) proteins of MERS-CoV and SARS-CoV determine the virus host tropism and entry into host cells, and constitute a promising target for the development of prophylactics and therapeutics. Here, we present high-resolution structures of the trimeric MERS-CoV and SARS-CoV S proteins in its pre-fusion conformation by single particle cryo-electron microscopy. The overall structures resemble that from other coronaviruses including HKU1, MHV and NL63 reported recently, with the exception of the receptor binding domain (RBD). We captured two states of the RBD with receptor binding region either buried (lying state) or exposed (standing state), demonstrating an inherently flexible RBD readily recognized by the receptor. Further sequence conservation analysis of six human-infecting coronaviruses revealed that the fusion peptide, HR1 region and the central helix are potential targets for eliciting broadly neutralizing antibodies.

Insecticidal activity of plant lectins and potential application in crop protection.

PubMed

Macedo, Maria Lígia R; Oliveira, Caio F R; Oliveira, Carolina T

2015-01-27

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.

Stability of Curcuma longa rhizome lectin: Role of N-linked glycosylation.

PubMed

Biswas, Himadri; Chattopadhyaya, Rajagopal

2016-04-01

Curcuma longa rhizome lectin, a mannose-binding protein of non-seed portions of turmeric, is known to have antifungal, antibacterial and α-glucosidase inhibitory activities. We studied the role of complex-type glycans attached to asparagine (Asn) 66 and Asn 110 to elucidate the role of carbohydrates in lectin activity and stability. Apart from the native lectin, the characteristics of a deglycosylated Escherichia coli expressed lectin, high-mannose oligosaccharides at both asparagines and its glycosylation mutants N66Q and N110Q expressed in Pichia pastoris, were compared to understand the relationship between glycosylation and activity. Far UV circular dichroism (CD) spectra, fluorescence emission maximum, hemagglutination assay show no change in secondary or tertiary structures or sugar-binding properties between wild-type and aforementioned recombinant lectins under physiological pH. But reduced agglutination activity and loss of tertiary structure are observed in the acidic pH range for the deglycosylated and the N110Q protein. In thermal and guanidine hydrochloride (GdnCl)-induced unfolding, the wild-type and high-mannose lectins possess higher stability compared with the deglycosylated recombinant lectin and both mutants, as measured by a higher Tm of denaturation or a greater free energy change, respectively. Reversibility experiments after thermal denaturation reveal that deglycosylated proteins tend to aggregate during thermal inactivation but the wild type shows a much greater recovery to the native state upon refolding. These results suggest that N-glycosylation in turmeric lectin is important for the maintenance of its proper folding upon changes in pH, and that the oligosaccharides help in maintaining the active conformation and prevent aggregation in unfolded or partially folded molecules. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Parkia pendula lectin as histochemistry marker for meningothelial tumour.

PubMed

Beltrão, E I C; Medeiros, P L; Rodrigues, O G; Figueredo-Silva, J; Valença, M M; Coelho, L C B B; Carvalho, L B

2003-01-01

Lectins have been intensively used in histochemical techniques for cell surface characterization. These proteins are involved in several biological processes and their use as histochemical markers have been evaluated since they can indicate differences in cell surfaces. Parkia pendula lectin (PpeL) was evaluated as histochemical marker for meningothelial meningioma biopsies. Tissue slices were incubated with PpeL conjugated to horseradish peroxidase (PpeL-HRP) and Concanavalin A-HRP (ConA-HPR) and the binding visualized with diaminobenzidine and hydrogen peroxide. The lectin-tissue binding was inhibited with D-glucose. PpeL showed to be a useful tool for the characterization of meningothelial tumour and clinico-pathological diagnosis.

Identification of Lectins from Metastatic Cancer Cells through Magnetic Glyconanoparticles

PubMed Central

Kavunja, Herbert W.; Voss, Patricia G.

2016-01-01

Cancer cells can have characteristic carbohydrate binding properties. Previously, it was shown that a highly metastatic melanoma cell line B16F10 bound to galacto-side-functionalized nanoparticles much stronger than the corresponding less metastatic B16F1 cells. To better understand the carbohydrate binding properties of cancer cells, herein, we report the isolation and characterization of endogenous galactose binding proteins from B16F10 cells using magnetic glyconanoparticles. The galactose-coated magnetic glyconanoparticles could bind with lectins present in the cells and be isolated through magnet-mediated separation. Through Western blot and mass spectrometry, the arginine/serine rich splicing factor Sfrs1 was identified as a galactose-selective endogenous lectin, overexpressed in B16F10 cells, compared with B16F1 cells. In addition, galactin-3 was found in higher amounts in B16F10 cells. Finally, the glyconanoparticles exhibited a superior efficiency in lectin isolation, from both protein mixtures and live cells, than the corresponding more traditional microparticles functionalized with carbohydrates. Thus, the magnetic glyconanoparticles present a useful tool for discovery of endogenous lectins, as well as binding partners of lectins, without prior knowledge of protein identities. PMID:27110035

Prevalence of multi and pan drug resistant Pseudomonas aeruginosa with respect to ESBL and MBL in a tertiary care hospital.

PubMed

Jayakumar, S; Appalaraju, B

2007-10-01

Multi drug resistant Pseudomonas aeruginosa (MDRPA) and pan drug resistant Pseudomonas aeruginosa (PDRPA) isolates in critically ill patients are often difficult to treat. Prevalence of MDRPA and their antibiotic profile was investigated to select an appropriate empirical therapy. Moreover lack of sufficient data on prevalence of PDRPA in tertiary care hospitals indicated the need for this study. Pseudomonas aeruginosa was isolated in 245 patients over a period of one and half years from various clinical materials and their antibiotic profile was determined. Minimum inhibitory concentration (MIC) for Imipenem and Meropenam was determined by broth dilution method. Phenotypic confirmation test and EDTA double disk synergy test was used to detect Extended spectrum a-lactamase (ESBL) and Metallo-a-lactamase (MBL) producers respectively. Out of 245 isolates, 54 strains (22 %) and 11 strains (4%) were found to be MDRPA and PDRPA respectively. Carbapenem resistant isolates showed MICs ranging from 16 to > 64 microg/ml. Thirty eight strains (15.5%) were ESBL producers and six (54.5%) among 11 PDRPA were MBL producers. Prevalence of MDR and PDR isolates of Pseudomonas aeruginosa was found to be 22% and 4% respectively, which is less compared to other studies. Majority of the PDRPA isolates were MBL producers which have propensity to spread to other bacteria.

Lectins in fish skin: do they play a role in host-monogenean interactions?

PubMed

Buchmann, K

2001-09-01

Mucus samples from rainbow trout skin with or without infections by Gyrodactylus derjavini were tested for the presence of lectins reacting with mannose, galactose and lactose. The samples inhibited the binding of biotinylated lectins (from Canavalia ensiformis, Artocarpus integrifolia and Erythrina corallodendron, respectively) to microtitre plates with covalently bound carbohydrates (mannopyranoside, galactopyranoside and lactose, respectively). However, the inhibition of C. ensiformis and A. integrifolia lectins was slightly greater when mucus from infected (but recovering) fish was used, suggesting an increase of mannose and galactose binding lectins in fish skin exposed to parasites. As mannose, galactose and lactose are present on the glycocalyx of Gyrodactylus derjavini, it is suggested that lectins could play a dual role in interactions between fish hosts and their monogenean parasites. Thus, recognition between parasite and host and also host responses towards parasite infections could both, at least partly, involve carbohydrate-lectin binding.

Prevalence of ESBL and MBL encoding genes in Acinetobacter baumannii strains isolated from patients of intensive care units (ICU)

PubMed Central

Safari, Marzieh; Mozaffari Nejad, Amir Sasan; Bahador, Abas; Jafari, Rasool; Alikhani, Mohammad Yousef

2015-01-01

The aim of this study was to investigate the prevalence of ESBL and MBL encoding genes among A. baumannii isolates. In this cross sectional study, 100 A. baumannii strains were isolated from ICU wards of 3 educational hospitals of Hamadan City, Iran in 2011. Phenotypic identification of the production of ESBLs and MBLs has been carried out by using E-test and DDST methods, respectively. PCR technique was used for amplification of the ESBL and MBL encoding genes, namely: CTX-M, SHV, TEM, OXA-51, VIM-Family, IMP-Family, SPM-1, SIM-1, and GIM-1. Eighty seven (87%), 95 (95%), 98 (98%) and 95 (95%) out of 100 A. baumannii isolates were resistant to imipenem, meropenem, ceftazidime and cefotaxime, respectively. Also, 99% and 7% of the isolates were MBLs and ESBLs produced phenotypically. Thirty (30%), 20 (20%) and 58 (58%) out of 100 A. baumannii isolates have been confirmed to harbor the blaVIM-family, TEM and SHV genes, respectively. Our results show no significant relationship between the detected gens with production of MBLs and ESBLs in spite of high prevalence of MBL encoding and drug resistant A. baumannii. Probably some other genes rather than what we studied are involved in phenotypic production of MBLs and ESBLs and subsequent drug resistance in Hamadan area, Iran. PMID:26150748

Mitogenic activity of new lectins from seeds of wild Artocarpus species from Vietnam.

PubMed

Blasco, E; Ngoc, L D; Aucouturier, P; Preud'Homme, J L; Barra, A

1996-05-01

Proliferative response of human peripheral blood mononuclear cells (PBMC) stimulated by new lectins purified from seeds of differents Artocarpus species from Vietnam (A. asperulus, A. heterophyllus, A. masticata, A. melinoxylus, A. parva and A. petelotii) was studied and compared to those of the lectin jacalin purified from jackfruit (A. heterophyllus) seeds collected in the island La Réunion. All lectins stimulated human PBMC to proliferate, with a variable efficiency of the mitogenic activity. Phenotypic analysis of cells recovered after 7 day-cultures showed that these lectins mostly stimulated CD4+ T lymphocytes. These results suggest that these lectins from different Artocarpus species are similar in terms of their mitogenic activity although their structural features are not identical.

Proteins with an Euonymus lectin-like domain are ubiquitous in Embryophyta

PubMed Central

2009-01-01

Background Cloning of the Euonymus lectin led to the discovery of a novel domain that also occurs in some stress-induced plant proteins. The distribution and the diversity of proteins with an Euonymus lectin (EUL) domain were investigated using detailed analysis of sequences in publicly accessible genome and transcriptome databases. Results Comprehensive in silico analyses indicate that the recently identified Euonymus europaeus lectin domain represents a conserved structural unit of a novel family of putative carbohydrate-binding proteins, which will further be referred to as the Euonymus lectin (EUL) family. The EUL domain is widespread among plants. Analysis of retrieved sequences revealed that some sequences consist of a single EUL domain linked to an unrelated N-terminal domain whereas others comprise two in tandem arrayed EUL domains. A new classification system for these lectins is proposed based on the overall domain architecture. Evolutionary relationships among the sequences with EUL domains are discussed. Conclusion The identification of the EUL family provides the first evidence for the occurrence in terrestrial plants of a highly conserved plant specific domain. The widespread distribution of the EUL domain strikingly contrasts the more limited or even narrow distribution of most other lectin domains found in plants. The apparent omnipresence of the EUL domain is indicative for a universal role of this lectin domain in plants. Although there is unambiguous evidence that several EUL domains possess carbohydrate-binding activity further research is required to corroborate the carbohydrate-binding properties of different members of the EUL family. PMID:19930663

Preparation of Ulex europaeus lectin-gliadin nanoparticle conjugates and their interaction with gastrointestinal mucus.

PubMed

Ezpeleta, I; Arangoa, M A; Irache, J M; Stainmesse, S; Chabenat, C; Popineau, Y; Orecchioni, A M

1999-11-25

One approach to improve the bioavailability and efficiency of drugs consists of the association of a ligand (i.e. lectins), showing affinity for biological structures located on the mucosa surfaces, to nanoparticulate drug delivery systems. In this context, Ulex europaeus lectin-gliadin nanoparticle conjugates (UE-GNP) were prepared with the aim of evaluating their in vitro bioadhesive properties. The lectin was fixed by a covalent procedure to gliadin nanoparticles by a two-stage carbodiimide method. Typically, the amount of bound lectin was calculated to be approximately 15 microg lectin/mg nanoparticle, which represented a coupling efficiency of approximately 16% of the initial lectin concentration. In addition, the activity of these conjugates was tested with bovine submaxillary gland mucin (BSM) and the level of binding to this mucin was always much greater with UE-GNP than with controls (gliadin nanoparticles). However, the presence of 50 micromol fucose, which is the reported specific sugar for U. europaeus lectin, specifically inhibited the activity of these conjugates and, therefore, the UE-GNP binding to BSM was attenuated by 70%. These results clearly showed that the activity and specificity of U. europaeus lectin was preserved after covalent coupling to these biodegradable carriers.

Screening natural libraries of human milk oligosaccharides against lectins using CaR-ESI-MS.

PubMed

El-Hawiet, Amr; Chen, Yajie; Shams-Ud-Doha, Km; Kitova, Elena N; Kitov, Pavel I; Bode, Lars; Hage, Naim; Falcone, Franco H; Klassen, John S

2018-01-15

Human milk oligosaccharides (HMOs) afford many health benefits to breast-fed infants, such as protection against infection and regulation of the immune system, through the formation of non-covalent interactions with protein receptors. However, the molecular details of these interactions are poorly understood. Here, we describe the application of catch-and-release electrospray ionization mass spectrometry (CaR-ESI-MS) for screening natural libraries of HMOs against lectins. The HMOs in the libraries were first identified based on molecular weights (MWs), ion mobility separation arrival times (IMS-ATs) and collision-induced dissociation (CID) fingerprints of their deprotonated anions. The libraries were then screened against lectins and the ligands identified from the MWs, IMS-ATs and CID fingerprints of HMOs released from the lectin in the gas phase. To demonstrate the assay, four fractions, extracted from pooled human milk and containing ≥35 different HMOs, were screened against a C-terminal fragment of human galectin-3 (hGal-3C), for which the HMOs specificities have been previously investigated, and a fragment of the blood group antigen-binding adhesin (BabA) from Helicobacter pylori, for which the HMO specificities have not been previously established. The structures of twenty-one ligands, corresponding to both neutral and acidic HMOs, of hGal-3C were identified; all twenty-one were previously shown to be ligands for this lectin. The presence of HMO ligands at six other MWs was also ascertained. Application of the assay to BabA revealed nineteen specific HMO structures that are recognized by the protein and HMO ligands at two other MWs. Notably, it was found that BabA exhibits broad specificity for HMOs, and recognizes both neutral HMOs, including non-fucosylated ones, and acidic HMOs. The results of competitive binding experiments indicate that HMOs can interact with BabA at previously unknown binding sites. The affinities of eight purified HMOs for BabA were

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.

Interaction of glycophorin A with lectins as measured by surface plasmon resonance (SPR).

PubMed

Krotkiewska, Bozena; Pasek, Marta; Krotkiewski, Hubert

2002-01-01

Glycophorin A (GPA), the major sialoglycoprotein of the human erythrocyte membrane, was isolated from erythrocytes of healthy individuals of blood groups A, B and O using phenol-water extraction of erythrocyte membranes. Interaction of individual GPA samples with three lectins (Psathyrella velutina lectin, PVL; Triticum vulgaris lectin, WGA and Sambucus nigra I agglutinin SNA-I) was analyzed using a BIAcore biosensor equipped with a surface plasmon resonance (SPR) detector. The experiments showed no substantial differences in the interaction between native and desialylated GPA samples originating from erythrocytes of either blood group and each of the lectins. Desialylated samples reacted weaker than the native ones with all three lectins. PVL reacted about 50-fold more strongly than WGA which, similar to PVL, recognizes GlcNAc and Neu5Ac residues. SNA-I lectin, recognizing alpha2-6 linked Neu5Ac residues, showed relatively weak reaction with native and only residual reaction with desialylated GPA samples. The data obtained show that SPR is a valuable method to determine interaction of glycoproteins with lectins, which potentially can be used to detect differences in the carbohydrate moiety of individual glycoprotein samples.

"Click" saccharide/beta-lactam hybrids for lectin inhibition.

PubMed

Palomo, Claudio; Aizpurua, Jesus M; Balentová, Eva; Azcune, Itxaso; Santos, J Ignacio; Jiménez-Barbero, Jesús; Cañada, Javier; Miranda, José Ignacio

2008-06-05

Hybrid glycopeptide beta-lactam mimetics designed to bind lectins or carbohydrate recognition domains in selectins have been prepared according to a "shape-modulating linker" design. This approach was implemented using the azide-alkyne "click" cycloaddition reaction, and as shown by NMR/MD experiments, binding of the resulting mimetics to Ulex Europaeus Lectin-1 (UEL-1) occurred after a "bent-to-extended" conformational change around a partially rotatable triazolylmethylene moiety.

Identification and transcriptional analysis of two types of lectins (SgCTL-1 and SgGal-1) from mollusk Solen grandis.

PubMed

Wei, Xiumei; Yang, Jianmin; Liu, Xiangquan; Yang, Dinglong; Xu, Jie; Fang, Jinghui; Wang, Weijun; Yang, Jialong

2012-08-01

C-type lectin and galectin are two types of animal carbohydrate-binding proteins which serve as pathogen recognition molecules and play crucial roles in the innate immunity of invertebrates. In the present study, a C-type lectin (designated as SgCTL-1) and galectin (designated as SgGal-1) were identified from mollusk Solen grandis, and their expression patterns, both in tissues and toward three pathogen-associated molecular patterns (PAMPs) stimulation were characterized. The full-length cDNA of SgCTL-1 and SgGal-1 was 1280 and 1466 bp, containing an open reading frame (ORF) of 519 and 1218 bp, respectively. Their deduced amino acid sequences showed high similarity to other members of C-type lectin and galectin superfamily, respectively. SgCTL-1 encoded a single carbohydrate-recognition domain (CRD), and the motif of Ca(2+)-binding site 2 was EPN (Glu(135)-Pro(136)-Asn(137)). While SgGal-1 encoded two CRDs, and the amino acid residues constituted the carbohydrate-binding motifs were well conserved in CRD1 but partially conserved in CRD2. Although SgCTL-1 and SgGal-1 exhibited different tissue expression pattern, they were both constitutively expressed in all tested tissues, including hemocytes, gonad, mantle, muscle, gill and hepatopancreas, and they were both highly expressed in hepatopancreas and gill. Furthermore, the mRNA expression of two lectins in hemocytes was significantly (P < 0.01) up-regulated with different levels after S. grandis were stimulated by lipopolysaccharide (LPS), peptidoglycan (PGN) or β-1,3-glucan. Our results suggested that SgCTL-1 and SgGal-1 from razor clam were two novel members of animal lectins, and they might function as pattern recognition receptors (PRRs) taking part in the process of pathogen recognition. Copyright © 2012 Elsevier Ltd. All rights reserved.

[Study on the extraction technology and hypoglycemic activity of lectin from Trichosanthes kirilowi].

PubMed

Li, Qiong; Ye, Xiao-Li; Zeng, Hong; Chen, Xin; Li, Xue-Gang

2012-03-01

To extract lectins from Trichosanthes kirilowi and study their hypoglycemic activity. The optimal extraction process included the following parameters were conformed by optimization analysis,lectins extracted from Trichosanthes kirilowi was achieved by ammonium sulfate precipitation; The agglutinate activity was determined by using the agglutination test with 5% human blood cells. Human hepatocarcinoma cell HepG2 and the alloxan-induced diabetic mice model were used to assess hypoglycemic activity of Lectin in Trichosanthes kirilowi. The agglutination indexes of lectins extraction buffer were 32; The cell and mice tests indicated that the lectins exhibited hypoglycemic activity in the 70% saturation. The optimum extraction technology is as follows: extraction with PBS, the material-water ratio is 1:30, the extraction time is 24 h, while the concentration of sodium chloride is 0 mol/L and pH is 7.2. Precipitate lectins by ammonium sulfate in the 70% saturation, centrifugal speed is 10 000 tracted from Trichosanthes kirilowi exposes proper hypoglycemic activity.

Symbiotic Bacteria Direct Expression of an Intestinal Bactericidal Lectin

PubMed Central

Cash, Heather L.; Whitham, Cecilia V.; Behrendt, Cassie L.; Hooper, Lora V.

2009-01-01

The mammalian intestine harbors complex societies of beneficial bacteria that are maintained in the lumen with minimal penetration of mucosal surfaces. Microbial colonization of germ-free mice triggers epithelial expression of RegIIIγ, a secreted C-type lectin. RegIIIγ binds intestinal bacteria but lacks the complement recruitment domains present in other microbe-binding mammalian C-type lectins. We show that RegIIIγ and its human counterpart, HIP/PAP, are directly antimicrobial proteins that bind their bacterial targets via interactions with peptidoglycan carbohydrate. We propose that these proteins represent an evolutionarily primitive form of lectin-mediated innate immunity, and that they reveal intestinal strategies for maintaining symbiotic host-microbial relationships. PMID:16931762

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 μg/mL, and on 3 cancer cells with IC50 values of 178.82-350.93 μg/mL. Notably, 5-fold reduction in IC50 values was observed on normal L-O2 vs cancerous HepG-2 cells (924.35 vs. 178.82 μg/mL). This suggests that BL should be promising in food and medicine. © 2015 American Institute of Chemical Engineers.

Purification of a thermostable antinociceptive lectin isolated from Andira anthelmia.

PubMed

Nascimento, Kyria Santiago; Nascimento, Francisco Lucas Faustino do; Silva, Mayara Torquato Lima; Nobre, Camila Bezerra; Moreira, Cleane Gomes; Brizeno, Luiz André Cavalcante; da Ponte, Edson Lopes; Assreuy, Ana Maria Sampaio; Cavada, Benildo Sousa

2016-06-01

Andira anthelmia (tribe Dalbergieae), a plant from Brazilian Amazon, possesses a seed lectin that was purified by affinity chromatography in sepharose-mannose. This novel Dalbergieae lectin, named AAL, agglutinated rabbit erythrocytes treated with trypsin. The hemagglutinating activity of AAL was maintained after incubation at a wide range of temperature (40 to 70 °C) and pH, was shown to be dependent on divalent cations, and was inhibited by d-mannose and d-sucrose. AAL showed an electrophoretic profile in sodium dodecyl sulfate-polyacrylamide gel electrophoresis similar to other lectins of the tribe Dalbergieae, presenting a double band of molecular weight with approximately 20 kDa and other minor bands of 17, 15, and 13 kDa, being the smaller fragment glycosylated. AAL injected by intravenous route in mice showed antinociceptive activity in two behavioral tests (writhing and formalin). In the writhing test induced by acetic acid, AAL showed inhibitory effect at 0.01 mg/kg (68%), 0.1 mg/kg (46%) and 1 mg/kg (74%). In the formalin test, AAL (0.1 mg/kg) inhibited by 48% the licking time in the inflammatory phase, an effect that was recovered by the lectin association with mannose. In conclusion, AAL presents analgesic effect involving the lectin domain via peripheral mechanisms of inflammatory nociception. This activity highlights the importance of lectins as tools to be used for understanding the interaction of protein-carbohydrate in processes associated to inflammatory pain. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Network analysis reveals the recognition mechanism for complex formation of mannose-binding lectins

NASA Astrophysics Data System (ADS)

Jian, Yiren; Zhao, Yunjie; Zeng, Chen

The specific carbohydrate binding of lectin makes the protein a powerful molecular tool for various applications including cancer cell detection due to its glycoprotein profile on the cell surface. Most biologically active lectins are dimeric. To understand the structure-function relation of lectin complex, it is essential to elucidate the short- and long-range driving forces behind the dimer formation. Here we report our molecular dynamics simulations and associated dynamical network analysis on a particular lectin, i.e., the mannose-binding lectin from garlic. Our results, further supported by sequence coevolution analysis, shed light on how different parts of the complex communicate with each other. We propose a general framework for deciphering the recognition mechanism underlying protein-protein interactions that may have potential applications in signaling pathways.

Integrated Microfluidic Lectin Barcode Platform for High-Performance Focused Glycomic Profiling

NASA Astrophysics Data System (ADS)

Shang, Yuqin; Zeng, Yun; Zeng, Yong

2016-02-01

Protein glycosylation is one of the key processes that play essential roles in biological functions and dysfunctions. However, progress in glycomics has considerably lagged behind genomics and proteomics, due in part to the enormous challenges in analysis of glycans. Here we present a new integrated and automated microfluidic lectin barcode platform to substantially improve the performance of lectin array for focused glycomic profiling. The chip design and flow control were optimized to promote the lectin-glycan binding kinetics and speed of lectin microarray. Moreover, we established an on-chip lectin assay which employs a very simple blocking method to effectively suppress the undesired background due to lectin binding of antibodies. Using this technology, we demonstrated focused differential profiling of tissue-specific glycosylation changes of a biomarker, CA125 protein purified from ovarian cancer cell line and different tissues from ovarian cancer patients in a fast, reproducible, and high-throughput fashion. Highly sensitive CA125 detection was also demonstrated with a detection limit much lower than the clinical cutoff value for cancer diagnosis. This microfluidic platform holds the potential to integrate with sample preparation functions to construct a fully integrated “sample-to-answer” microsystem for focused differential glycomic analysis. Thus, our technology should present a powerful tool in support of rapid advance in glycobiology and glyco-biomarker development.

Integrated Microfluidic Lectin Barcode Platform for High-Performance Focused Glycomic Profiling

PubMed Central

Shang, Yuqin; Zeng, Yun; Zeng, Yong

2016-01-01

Protein glycosylation is one of the key processes that play essential roles in biological functions and dysfunctions. However, progress in glycomics has considerably lagged behind genomics and proteomics, due in part to the enormous challenges in analysis of glycans. Here we present a new integrated and automated microfluidic lectin barcode platform to substantially improve the performance of lectin array for focused glycomic profiling. The chip design and flow control were optimized to promote the lectin-glycan binding kinetics and speed of lectin microarray. Moreover, we established an on-chip lectin assay which employs a very simple blocking method to effectively suppress the undesired background due to lectin binding of antibodies. Using this technology, we demonstrated focused differential profiling of tissue-specific glycosylation changes of a biomarker, CA125 protein purified from ovarian cancer cell line and different tissues from ovarian cancer patients in a fast, reproducible, and high-throughput fashion. Highly sensitive CA125 detection was also demonstrated with a detection limit much lower than the clinical cutoff value for cancer diagnosis. This microfluidic platform holds the potential to integrate with sample preparation functions to construct a fully integrated “sample-to-answer” microsystem for focused differential glycomic analysis. Thus, our technology should present a powerful tool in support of rapid advance in glycobiology and glyco-biomarker development. PMID:26831207

Interaction of a lectin from Psathyrella velutina mushroom with N-acetylneuraminic acid.

PubMed

Ueda, H; Kojima, K; Saitoh, T; Ogawa, H

1999-04-01

A lectin from the fruiting body of Psathyrella velutina has been used as a specific probe for non-reducing terminal N-acetylglucosamine residues. We reveal in this report that P. velutina lectin recognizes a non-reducing terminal N-acetylneuraminic acid residue in glycoproteins and oligosaccharides. Binding of biotinyl P. velutina lectin to N-acetylneuraminic acid residues was prevented by desialylation of glycoconjugates and was distinguished from the binding to N-acetylglucosamine. Sialooligosaccharides were retarded or bound and eluted with N-acetylglucosamine on a P. velutina lectin column, being differentiated from each other and also from the oligosaccharides with non-reducing terminal N-acetylglucosamine which bound more strongly to the column.

Integrative analysis workflow for the structural and functional classification of C-type lectins

PubMed Central

2011-01-01

Background It is important to understand the roles of C-type lectins in the immune system due to their ubiquity and diverse range of functions in animal cells. It has been observed that currently confirmed C-type lectins share a highly conserved domain known as the C-type carbohydrate recognition domain (CRD). Using the sequence profile of the CRD, an increasing number of putative C-type lectins have been identified. Hence, it is highly needed to develop a systematic framework that enables us to elucidate their carbohydrate (glycan) recognition function, and discover their physiological and pathological roles. Results Presented herein is an integrated workflow for characterizing the sequence and structural features of novel C-type lectins. Our workflow utilizes web-based queries and available software suites to annotate features that can be found on the C-type lectin, given its amino acid sequence. At the same time, it incorporates modeling and analysis of glycans - a major class of ligands that interact with C-type lectins. Thereafter, the results are analyzed together with context-specific knowledge to filter off unlikely predictions. This allows researchers to design their subsequent experiments to confirm the functions of the C-type lectins in a systematic manner. Conclusions The efficacy and usefulness of our proposed immunoinformatics workflow was demonstrated by applying our integrated workflow to a novel C-type lectin -CLEC17A - and we report some of its possible functions that warrants further validation through wet-lab experiments. PMID:22372988

A sperm-agglutinating lectin from seeds of Jack fruit (Artocarpus heterophyllus).

PubMed

Namjuntra, P; Muanwongyathi, P; Chulavatnatol, M

1985-04-30

A lectin specific for N-acetylgalactosamine was isolated from seed extract of Jack fruit (Artocarpus heterophyllus) by ammonium sulfate precipitation, followed by affinity chromatography on a Affigel-galactosamine-agarose column. The lectin possessed agglutinating activities for human and rat sperm as well as human red blood cells. It was found to have Mr = 62,000 consisting of two dissimilar subunits of Mr = 18,000 and 13,000. It also cross-reacted with an antibody against the lectin of Osage Orange (Maclura pomifera).

Responsive Photonic Crystal Carbohydrate Hydrogel Sensor Materials for Selective and Sensitive Lectin Protein Detection.

PubMed

Cai, Zhongyu; Sasmal, Aniruddha; Liu, Xinyu; Asher, Sanford A

2017-10-27

Lectin proteins, such as the highly toxic lectin protein, ricin, and the immunochemically important lectin, jacalin, play significant roles in many biological functions. It is highly desirable to develop a simple but efficient method to selectively detect lectin proteins. Here we report the development of carbohydrate containing responsive hydrogel sensing materials for the selective detection of lectin proteins. The copolymerization of a vinyl linked carbohydrate monomer with acrylamide and acrylic acid forms a carbohydrate hydrogel that shows specific "multivalent" binding to lectin proteins. The resulting carbohydrate hydrogels are attached to 2-D photonic crystals (PCs) that brightly diffract visible light. This diffraction provides an optical readout that sensitively monitors the hydrogel volume. We utilize lactose, galactose, and mannose containing hydrogels to fabricate a series of 2-D PC sensors that show strong selective binding to the lectin proteins ricin, jacalin, and concanavalin A (Con A). This binding causes a carbohydrate hydrogel shrinkage which significantly shifts the diffraction wavelength. The resulting 2-D PC sensors can selectively detect the lectin proteins ricin, jacalin, and Con A. These unoptimized 2-D PC hydrogel sensors show a limit of detection (LoD) of 7.5 × 10 -8 M for ricin, a LoD of 2.3 × 10 -7 M for jacalin, and a LoD of 3.8 × 10 -8 M for Con A, respectively. This sensor fabrication approach may enable numerous sensors for the selective detection of numerous lectin proteins.

Comparative Study of Lectin Domains in Model Species: New Insights into Evolutionary Dynamics

PubMed Central

Van Holle, Sofie; De Schutter, Kristof; Eggermont, Lore; Tsaneva, Mariya; Dang, Liuyi; Van Damme, Els J. M.

2017-01-01

Lectins are present throughout the plant kingdom and are reported to be involved in diverse biological processes. In this study, we provide a comparative analysis of the lectin families from model species in a phylogenetic framework. The analysis focuses on the different plant lectin domains identified in five representative core angiosperm genomes (Arabidopsis thaliana, Glycine max, Cucumis sativus, Oryza sativa ssp. japonica and Oryza sativa ssp. indica). The genomes were screened for genes encoding lectin domains using a combination of Basic Local Alignment Search Tool (BLAST), hidden Markov models, and InterProScan analysis. Additionally, phylogenetic relationships were investigated by constructing maximum likelihood phylogenetic trees. The results demonstrate that the majority of the lectin families are present in each of the species under study. Domain organization analysis showed that most identified proteins are multi-domain proteins, owing to the modular rearrangement of protein domains during evolution. Most of these multi-domain proteins are widespread, while others display a lineage-specific distribution. Furthermore, the phylogenetic analyses reveal that some lectin families evolved to be similar to the phylogeny of the plant species, while others share a closer evolutionary history based on the corresponding protein domain architecture. Our results yield insights into the evolutionary relationships and functional divergence of plant lectins. PMID:28587095

Quantitation of two endogenous lactose-inhibitable lectins in embryonic and adult chicken tissues

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

Beyer, E.C.; Barondes, S.H.

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 bothmore » 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.« less

Purification and characterization of a new type lactose-binding Ulex europaeus lectin by affinity chromatography.

PubMed

Konami, Y; Yamamoto, K; Osawa, T

1991-02-01

A new type lactose-binding lectin was purified from extracts of Ulex europaeus seeds by affinity chromatography on a column of galactose-Sepharose 4B, followed by gel filtration on Sephacryl S-300. This lectin, designated as Ulex europaeus lectin III (UEA-III), was found to be inhibited by lactose. The dimeric lectin is a glycoprotein with a molecular mass of 70,000 Da; it consists of two apparently identical subunits of a molecular mass of 34,000 Da. Compositional analysis showed that this lectin contains 30% carbohydrate and a large amount of aspartic acid, serine and valine, but no sulfur-containing amino acids. The N-terminal amino-acid sequences of L-fucose-binding Ulex europaeus lectin I (UEA-I) and di-N-acetylchitobiose-binding Ulex europaeus lectin II (UEA-II), both of which we have already purified and characterized, and that of UEA-III were determined and compared.

CBP70, a glycosylated nuclear lectin.

PubMed

Rousseau, C; Felin, M; Doyennette-Moyne, M A; Sève, A P

1997-09-01

Some years ago, a lectin designated CBP70 that recognized glucose (Glc) but had a stronger affinity for N-acetylglucosamine (GlcNAc), was first isolated from HL60 cell nuclei. Recently, a cytoplasmic form of this lectin was described, and one 82 kDa nuclear ligand was characterized for the nuclear CBP70. In the present study, the use of Pronase digestion and the trifluoromethanesulphonic acid (TFMS) procedure strongly suggest that the nuclear and the cytoplasmic CBP70 have a same 23 kDa polypeptide backbone and, consequently, could be the same protein. In order to know the protein better and to obtain the best recombinant possible in the future, the post-translational modification of the nuclear and cytoplasmic CBP70 was analyzed in terms of glycosylation. Severals lines of evidence indicate that both forms of CBP70 are N- and O-glycosylated. Surprisingly, this glycosylation pattern differs between the two forms, as revealed by beta-elimination, hydrazinolysis, peptide-N-glycosydase F (PNGase F), and TFMS reactions. The two preparations were analyzed by affinity chromatography on immobilized lectins [Ricinus communis-l agglutinin (RCA-I), Arachis hypogaea agglutinin (PNA), Galanthus nivalis agglutinin (GNA), and wheat germ agglutinin (WGA)] and by lectin-blotting analysis Sambucus nigra agglutinin (SNA), Maackia amurensis agglutinin (MAA), Lotus tetragonolobus (Lotus), succinylated-WGA, and Psathyrella velutina agglutinin (PVA)]. Both forms of CBP70 have the following sugar moities: terminal beta Gal residues, Gal beta 1-3 GalNAc, Man alpha 1-3 Man, sialic acid alpha 2-6 linked to Gal or GalNAc; and sialic acid alpha 2-3 linked to Gal. However, only nuclear CBP70 have terminal GlcNAc and alpha-L-fucose residues. All these data are consistent with the fact that different glycosylation pattern found for each form of CBP70 might act as a complementary signal for cellular targeting.

In vivo evolution of HIV-1 co-receptor usage and sensitivity to chemokine-mediated suppression.

PubMed

Scarlatti, G; Tresoldi, E; Björndal, A; Fredriksson, R; Colognesi, C; Deng, H K; Malnati, M S; Plebani, A; Siccardi, A G; Littman, D R; Fenyö, E M; Lusso, P

1997-11-01

Following the identification of the C-C chemokines RANTES, MIP-1alpha and MIP-1beta as major human immunodeficiency virus (HIV)-suppressive factors produced by CD8+ T cells, several chemokine receptors were found to serve as membrane co-receptors for primate immunodeficiency lentiretroviruses. The two most widely used co-receptors thus far recognized, CCR5 and CXCR4, are expressed by both activated T lymphocytes and mononuclear phagocytes. CCR5, a specific RANTES, MIP-1alpha and MIP-1 receptor, is used preferentially by non-MT2-tropic HIV-1 and HIV-2 strains and by simian immunodeficiency virus (SIV), whereas CXCR4, a receptor for the C-X-C chemokine SDF-1, is used by MT2-tropic HIV-1 and HIV-2, but not by SIV. Other receptors with a more restricted cellular distribution, such as CCR2b, CCR3 and STRL33, can also function as co-receptors for selected viral isolates. The third variable region (V3) of the gp120 envelope glycoprotein of HIV-1 has been fingered as a critical determinant of the co-receptor choice. Here, we document a consistent pattern of evolution of viral co-receptor usage and sensitivity to chemokine-mediated suppression in a longitudinal follow-up of children with progressive HIV-1 infection. Viral isolates obtained during the asymptomatic stages generally used only CCR5 as a co-receptor and were inhibited by RANTES, MIP-1alpha and MIP-1beta, but not by SDF-1. By contrast, the majority of the isolates derived after the progression of the disease were resistant to C-C chemokines, having acquired the ability to use CXCR4 and, in some cases, CCR3, while gradually losing CCR5 usage. Surprisingly, most of these isolates were also insensitive to SDF-1, even when used in combination with RANTES. An early acquisition of CXCR4 usage predicted a poor prognosis. In children who progressed to AIDS without a shift to CXCR4 usage, all the sequential isolates were CCR5-dependent but showed a reduced sensitivity to C-C chemokines. Discrete changes in the V3 domain

Genetic Variation Linked to Lung Cancer Survival in White Smokers | Center for Cancer Research

Cancer.gov

CCR investigators have discovered evidence that links lung cancer survival with genetic variations (called single nucleotide polymorphisms) in the MBL2 gene, a key player in innate immunity. The variations in the gene, which codes for a protein called the mannose-binding lectin, occur in its promoter region, where the RNA polymerase molecule binds to start transcription, and

Surface functions during mitosis. III. Quantitative analysis of ligand- receptor movement into the cleavage furrow: diffusion vs. flow

PubMed Central

1982-01-01

The surface distribution of concanavalin A (Con A) bound to cell membrane receptors varies dramatically as a function of mitotic phase. The lectin is distributed diffusely on cells labeled and observed between mid-prophase and early anaphase, whereas cells observed in late anaphase or telophase demonstrate a marked accumulation of Con A- receptor complexes over the developing cleavage furrow (Berlin, Oliver, and Walter. 1978. Cell. 15:327-341). In this report, we first use a system based on video intensification fluorescence microscopy to describe the simultaneous changes in cell shape and in lectin-receptor complex topography during progression of single cells through the mitotic cycle. The video analysis establishes that fluorescein succinyl Con A (F-S Con A)-receptor complex redistribution begins coincident with the first appearance of the cleavage furrow and is essentially complete within 2-3 min. This remarkable redistribution of surface fluorescence occurs during only a modest change in cell shape from a sphere to a belted cylinder. It reflects the translocation of complexes and not the accumulation of excess labeled membrane in the cleavage furrow: first, bound fluorescent cholera toxin which faithfully outlines the plasma membrane is not accumulated in the cleavage furrow, and, second, electron microscopy of peroxidase-Con A labeled cells undergoing cleavage shows that there is a high linear density of lectin within the furrow while Con A is virtually eliminated from the poles. The rate of surface movement of F-S Con A was quantitated by photon counting during a repetitive series of laser-excited fluorescence scans across dividing cells. Results were analyzed in terms of two alternative models of movement: a flow model in which complexes moved unidirectionally at constant velocity, and a diffusion model in which complexes could diffuse freely but were trapped at the cleavage furrow. According to these models, the observed rates of accumulation were

Lectin histochemistry of metastatic adenocarcinomas of the lung.

PubMed

Thöm, Ina; Schult-Kronefeld, Olaf; Burkholder, Iris; Goern, Michael; Andritzky, Birte; Blonski, Katharina; Kugler, Christian; Edler, Lutz; Bokemeyer, Carsten; Schumacher, Udo; Laack, Eckart

2007-06-01

Several clinical studies indicate that primary tumour cells with high metastatic potential often show aberrant glycosylation as detected by lectin histochemistry. However, it is unclear whether aberrant glycosylation is still present in metastatic deposits. The aim of the present investigation was thus to analyse a possible association between the presence of lectin binding sites of pulmonary adenocarcinoma cells and their lymph node and haematogenous metastatic cells. For this purpose, the expression of HPA, PHA-L and UEA-I was assessed in primary tumours, lymph node metastases and haematogenous metastases of 96 patients with metastatic adenocarcinomas of the lung that underwent surgery between 1999 and 2002. Besides, lectin-binding data and other known prognostic factors were correlated with survival. We found a significant positive correlation between the binding of the lectins HPA (p=0.002), PHA-L (p<0.00001) and UEA-I (p<0.00001) to the cells of the primary tumour and to their lymph node metastases. There was a positive correlation between the binding of HPA to the cells of the primary tumour and the haematogenous metastases as well. Patients with tumours which did not show HPA binding sites had a median overall survival of 27.9 months (95%-CI 7.7-infinity months). Patients with a HPA binding tumour had a median overall survival of 20.9 months (95%-CI 18.5-28.7 months). This is the first investigation to demonstrate a positive correlation between the binding of the lectins HPA, PHA-L and UEA-I to the cells of the primary tumour and to their lymph node metastases. Expression of HPA binding sites is also preserved in the haematogenous metastases. In summary, our results support the hypothesis that altered glycosylation of the membrane-bound glycoproteins of the tumour cells is associated with, but not sufficient for promotion of lymphogenic and haematogenous metastasis.

Scabies Mite Peritrophins Are Potential Targets of Human Host Innate Immunity

PubMed Central

Holt, Deborah C.; Kemp, Dave J.; Fischer, Katja

2011-01-01

Background Pruritic scabies lesions caused by Sarcoptes scabiei burrowing in the stratum corneum of human skin facilitate opportunistic bacterial infections. Emerging resistance to current therapeutics emphasizes the need to identify novel targets for protective intervention. We have characterized several protein families located in the mite gut as crucial factors for host-parasite interactions. Among these multiple proteins inhibit human complement, presumably to avoid complement-mediated damage of gut epithelial cells. Peritrophins are major components of the peritrophic matrix often found in the gut of arthropods. We hypothesized that a peritrophin, if abundant in the scabies mite gut, could be an activator of complement. Methodology/Principal Findings A novel full length scabies mite peritrophin (SsPTP1) was identified in a cDNA library from scabies mites. The amino acid sequence revealed four putative chitin binding domains (CBD). Recombinant expression of one CBD of the highly repetitive SsPTP1 sequence as TSP-hexaHis-fusion protein resulted in soluble protein, which demonstrated chitin binding activity in affinity chromatography assays. Antibodies against a recombinant SsPTP1 fragment were used to immunohistochemically localize native SsPTP1 in the mite gut and in fecal pellets within the upper epidermis, co-localizing with serum components such as host IgG and complement. Enzymatic deglycosylation confirmed strong N- and O-glycosylation of the native peritrophin. Serum incubation followed by immunoblotting with a monoclonal antibody against mannan binding lectin (MBL), the recognition molecule of the lectin pathway of human complement activation, indicated that MBL may specifically bind to glycosylated SsPTP1. Conclusions/Significance This study adds a new aspect to the accumulating evidence that complement plays a major role in scabies mite biology. It identifies a novel peritrophin localized in the mite gut as a potential target of the lectin pathway of

Innate Immunity in Lobsters: Partial Purification and Characterization of a Panulirus cygnus Anti-A Lectin.

PubMed

Flower, Robert L P

2012-01-01

A lectin detected in haemolymph from the Australian spiny lobster Panulirus cygnus agglutinated human ABO Group A cells to a higher titre than Group O or B. The lectin also agglutinated rat and sheep erythrocytes, with reactivity with rat erythrocytes strongly enhanced by treatment with the proteolytic enzyme papain, an observation consistent with reactivity via a glycolipid. The lectin, purified by affinity chromatography on fixed rat-erythrocyte stroma, was inhibited equally by N-acetylglucosamine and N-acetylgalactosamine. Comparison of data from gel filtration of haemolymph (behaving as a 1,800,000 Da macromolecule), and polyacrylamide gel electrophoresis of purified lectin (a single 67,000 Da band), suggested that in haemolymph the lecin was a multimer. The purified anti-A lectin autoprecipitated unless the storage solution contained chaotropic inhibitors (125 mmol/L sucrose: 500 mmol/L urea). The properties of this anti-A lectin and other similar lectins are consistent with a role in innate immunity in these invertebrates.

Validation of satellite-retrieved MBL cloud properties using DOE ARM AMF measurements at the Azores

NASA Astrophysics Data System (ADS)

Xi, B.; Dong, X.; Minnis, P.; Sun-Mack, S.

2013-05-01

Marine Boundary Layer (MBL) cloud properties derived for the Clouds and the Earth's Radiant Energy System (CERES) Project using Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) data are compared with observations taken at the Atmospheric Radiation Measurement (ARM) AMF AZORES site from June 2009 through December 2010. Retrievals from ARM surface-based data were averaged over a 1-hour interval centered at the time of each satellite overpass, and the CERES-MODIS Ed4 cloud properties were averaged within a 30-km x 30-km box centered on the ARM AZORES site. Two datasets were analyzed: all of the single-layered unbroken decks (SL) and those cases without temperature inversions. The CERES-MODIS cloud top/base heights were determined from cloud top/base temperature by using a lapse rate method normalized to the 24-h mean surface air temperature. The preliminary results show: for all SL MBL at daytime, they are, on average, 0.148 km (cloud top) and 0.087 km (cloud base) higher than the ARM radar-lidar observed cloud top and base, respectively. At nighttime, they are 0.446 km (cloud top) and 0.334 km (cloud base). For those cases without temperature inversions, the comparisons are close to their SL counterparts. For cloud temperatures, the MODIS-derived cloud-top and -base temperatures are 1.6 K lower and 0.4 K higher than the surface values with correlations of 0.92 during daytime. At nighttime, the differences are slightly larger and correlations are lower than daytime comparisons. Variations in the height difference are mainly caused by uncertainties in the surface air temperatures and lapse rates. Based on a total of 61 daytime and 87 nighttime samples (ALL SL cases), the temperature inversion layers occur about 72% during daytime and 83% during nighttime. The difference of surface-observed lapse rate and the satellite derived lapse rate can be 1.6 K/km for daytime and 3.3K/km for nighttime. From these lapse rates, we can further analyze the surface

THE RGM/DRAGON FAMILY OF BMP CO-RECEPTORS

PubMed Central

Corradini, Elena; Babitt, Jodie L.; Lin, Herbert Y.

2013-01-01

The BMP signaling pathway controls a number of cell processes during development and in adult tissues. At the cellular level, ligands of the BMP family act by binding a hetero-tetrameric signaling complex, composed of two type I and two type II receptors. BMP ligands make use of a limited number of receptors, which in turn activate a common signal transduction cascade at the intracellular level. A complex regulatory network is required in order to activate the signaling cascade at proper times and locations, and to generate specific downstream effects in the appropriate cellular context. One such regulatory mechanism is the repulsive guidance molecule (RGM) family of BMP co-receptors. This article reviews the current knowledge regarding the structure, regulation, and function of RGMs, focusing on known and potential roles of RGMs in physiology and pathophysiology. PMID:19897400

Differentiation of Bacillus Anthracis and Other Bacillus Species by Use of Lectins

DTIC Science & Technology

1983-07-18

TITL9 fAnd Subtfitle) S.TypeO REPORT gi PZRCC rvt 4 DIFFERENTIATION OF BACIL-LUSg’ ANTHRAtgACIS D OTHER BACILLUS , SPECIES BY-USE OYLECTINS" Inter[im...Ricinus communis. Some strains of Bacillus cer-eus var. m-ycoides (B. Mycoides) were strongly reactive with the lectin from Helbi pomtia and weakly reacti...ve with the Glycine max lectin. The differential iCnteractions between Bacillus species and lectins af forded a means of distinguishing B. anthracis

CoMSIA and Docking Study of Rhenium Based Estrogen Receptor Ligand Analogs

PubMed Central

Wolohan, Peter; Reichert, David E.

2007-01-01

OPLS all atom force field parameters were developed in order to model a diverse set of novel rhenium based estrogen receptor ligands whose relative binding affinities (RBA) to the estrogen receptor alpha isoform (ERα) with respect to 17β-Estradiol were available. The binding properties of these novel rhenium based organometallic complexes were studied with a combination of Comparative Molecular Similarity Indices Analysis (CoMSIA) and docking. A total of 29 estrogen receptor ligands consisting of 11 rhenium complexes and 18 organic ligands were docked inside the ligand-binding domain (LBD) of ERα utilizing the program Gold. The top ranked pose was used to construct CoMSIA models from a training set of 22 of the estrogen receptor ligands which were selected at random. In addition scoring functions from the docking runs and the polar volume (PV) were also studied to investigate their ability to predict RBA ERα. A partial least-squares analysis consisting of the CoMSIA steric, electrostatic and hydrophobic indices together with the polar volume proved sufficiently predictive having a correlation coefficient, r2, of 0.94 and a cross-validated correlation coefficient, q2, utilizing the leave one out method of 0.68. Analysis of the scoring functions from Gold showed particularly poor correlation to RBA ERα which did not improve when the rhenium complexes were extracted to leave the organic ligands. The combined CoMSIA and polar volume model ranked correctly the ligands in order of increasing RBA ERα, illustrating the utility of this method as a prescreening tool in the development of novel rhenium based estrogen receptor ligands. PMID:17280694

C-type lectins: their network and roles in pathogen recognition and immunity.

PubMed

Mayer, Sabine; Raulf, Marie-Kristin; Lepenies, Bernd

2017-02-01

C-type lectins (CTLs) represent the most complex family of animal/human lectins that comprises 17 different groups. During evolution, CTLs have developed by diversification to cover a broad range of glycan ligands. However, ligand binding by CTLs is not necessarily restricted to glycans as some CTLs also bind to proteins, lipids, inorganic molecules, or ice crystals. CTLs share a common fold that harbors a Ca 2+ for contact to the sugar and about 18 invariant residues in a phylogenetically conserved pattern. In vertebrates, CTLs have numerous functions, including serum glycoprotein homeostasis, pathogen sensing, and the initiation of immune responses. Myeloid CTLs in innate immunity are mainly expressed by antigen-presenting cells and play a prominent role in the recognition of a variety of pathogens such as fungi, bacteria, viruses, and parasites. However, myeloid CTLs such as the macrophage inducible CTL (Mincle) or Clec-9a may also bind to self-antigens and thus contribute to immune homeostasis. While some CTLs induce pro-inflammatory responses and thereby lead to activation of adaptive immune responses, other CTLs act as inhibitory receptors and dampen cellular functions. Since CTLs are key players in pathogen recognition and innate immunity, targeting CTLs may be a promising strategy for cell-specific delivery of drugs or vaccine antigens and to modulate immune responses.

Characterization of the receptors for mycobacterial cord factor in Guinea pig.

PubMed

Toyonaga, Kenji; Miyake, Yasunobu; Yamasaki, Sho

2014-01-01

Guinea pig is a widely used animal for research and development of tuberculosis vaccines, since its pathological disease process is similar to that present in humans. We have previously reported that two C-type lectin receptors, Mincle (macrophage inducible C-type lectin, also called Clec4e) and MCL (macrophage C-type lectin, also called Clec4d), recognize the mycobacterial cord factor, trehalose-6,6'-dimycolate (TDM). Here, we characterized the function of the guinea pig homologue of Mincle (gpMincle) and MCL (gpMCL). gpMincle directly bound to TDM and transduced an activating signal through ITAM-bearing adaptor molecule, FcRγ. Whereas, gpMCL lacked C-terminus and failed to bind to TDM. mRNA expression of gpMincle was detected in the spleen, lymph nodes and peritoneal macrophages and it was strongly up-regulated upon stimulation of zymosan and TDM. The surface expression of gpMincle was detected on activated macrophages by a newly established monoclonal antibody that also possesses a blocking activity. This antibody potently suppressed TNF production in BCG-infected macrophages. Collectively, gpMincle is the TDM receptor in the guinea pig and TDM-Mincle axis is involved in host immune responses against mycobacteria.

Exploring the Phenomenon of "Change of Phase" of Pure Substances Using the Microcomputer-Based-Laboratory (MBL) System

ERIC Educational Resources Information Center

Pierri, Evgenia; Karatrantou, Anthi; Panagiotakopoulos, Chris

2008-01-01

We examined how first year students (10th grade) of Greek Senior High School could conceptualize the influence of the molecular weight of saturated fatty acids on the melting and the freezing point, during the "change of phase" phenomenon using the Microcomputer-Based Laboratory (MBL) system. Students had to freeze a melted substance,…

Rat nicotinic ACh receptor α7 and β2 subunits co-assemble to form functional heteromeric nicotinic receptor channels

PubMed Central

Khiroug, Serguei S; Harkness, Patricia C; Lamb, Patricia W; Sudweeks, Sterling N; Khiroug, Leonard; Millar, Neil S; Yakel, Jerrel L

2002-01-01

Rat hippocampal interneurons express diverse subtypes of functional nicotinic acetylcholine receptors (nAChRs), including α7-containing receptors that have properties unlike those expected for homomeric α7 nAChRs. We previously reported a strong correlation between expression of the α7 and of the β2 subunits in individual neurons. To explore whether co-assembly of the α7 and β2 subunits might occur, these subunits were co-expressed in Xenopus oocytes and the functional properties of heterologously expressed nAChRs were characterized by two-electrode voltage clamp. Co-expression of the β2 subunit, both wild-type and mutant forms, with the α7 subunit significantly slowed the rate of nAChR desensitization and altered the pharmacological properties. Whereas ACh, carbachol and choline were full or near-full agonists for homomeric α7 receptor channels, both carbachol and choline were only partial agonists in oocytes expressing both α7 and β2 subunits. In addition the EC50 values for all three agonists significantly increased when the β2 subunit was co-expressed with the α7 subunit. Co-expression with the β2 subunit did not result in any significant change in the current-voltage curve. Biochemical evidence for the co-assembly of the α7 and β2 subunits was obtained by co-immunoprecipitation of these subunits from transiently transfected human embryonic kidney (TSA201) cells. These data provide direct biophysical and molecular evidence that the nAChR α7 and β2 subunits co-assemble to form a functional heteromeric nAChR with functional and pharmacological properties different from those of homomeric α7 channels. This co-assembly may help to explain nAChR channel diversity in rat hippocampal interneurons, and perhaps in other areas of the nervous system. PMID:11956333

Mucosal immunogenicity of plant lectins in mice

PubMed Central

Lavelle, E C; Grant, G; Pusztai, A; Pfüller, U; O’Hagan, D T

2000-01-01

The mucosal immunogenicity of a number of plant lectins with different sugar specificities was investigated in mice. Following intranasal (i.n.) or oral administration, the systemic and mucosal antibody responses elicited were compared with those induced by a potent mucosal immunogen (cholera toxin; CT) and a poorly immunogenic protein (ovalbumin; OVA). After three oral or i.n. doses of CT, high levels of specific serum antibodies were measured and specific IgA was detected in the serum, saliva, vaginal wash, nasal wash and gut wash of mice. Immunization with OVA elicited low titres of serum IgG but specific IgA was not detected in mucosal secretions. Both oral and i.n. delivery of all five plant lectins investigated [Viscum album (mistletoe lectin 1; ML‐1), Lycospersicum esculentum (tomato lectin; LEA), Phaseolus vulgaris (PHA), Triticum vulgaris (wheat germ agglutinin (WGA), Ulex europaeus I (UEA‐1)] stimulated the production of specific serum IgG and IgA antibody after three i.n. or oral doses. Immunization with ML‐1 induced high titres of serum IgG and IgA in addition to specific IgA in mucosal secretions. The response to orally delivered ML‐1 was comparable to that induced by CT, although a 10‐fold higher dose was administered. Immunization with LEA also induced high titres of serum IgG, particularly after i.n. delivery. Low specific IgA titres were also detected to LEA in mucosal secretions. Responses to PHA, WGA and UEA‐1 were measured at a relatively low level in the serum, and little or no specific mucosal IgA was detected. PMID:10651938

Two C-type lectins from shrimp Litopenaeus vannamei that might be involved in immune response against bacteria and virus.

PubMed

Wei, Xiumei; Liu, Xiangquan; Yang, Jianmin; Fang, Jinghui; Qiao, Hongjin; Zhang, Ying; Yang, Jialong

2012-01-01

C-type lectins play crucial roles in innate immunity to recognize and eliminate pathogens efficiently. In the present study, two C-type lectins from shrimp Litopenaeus vannamei (designated as LvLectin-1 and LvLectin-2) were identified, and their expression patterns, both in tissues and toward pathogen stimulation, were then characterized. The full-length cDNA of LvLectin-1 and LvLectin-2 was 567 and 625 bp, containing an open reading frame (ORF) of 471 and 489 bp, respectively, and deduced amino acid sequences showed high similarity to other members of C-type lectin superfamily. Both two C-type lectins encoded a single carbohydrate-recognition domain (CRD). The motif of Ca(2+) binding site 2 in CRD, which determined carbohydrate-binding specificity, was QPN (Gln(122)-Pro(123)-Asn(124)) in LvLectin-1, but QPD (Gln(128)-Pro(129)-Asp(130)) in LvLectin-2. Two C-type lectins exhibited similar tissue expression pattern, for their mRNA were both constitutively expressed in all tested tissues, including hepatopancreas, muscle, gill, hemocytes, gonad and heart, furthermore they were both mostly expressed in hepatopancreas, though the expression level of LvLectin-2 was much higher than LvLectin-1. The expression level of two C-type lectins mRNA in hemocytes varied greatly after the challenge of Listonella anguillarum or WSSV. After L. anguillarum challenge, the expression of both C-type lectins were significantly (P<0.01) up-regulated compared with blank group, and LvLectin-1 exhibited higher level than LvLectin-2; while after the stimulation of WSSV, the expression of LvLectin-2 was significantly up-regulated at 6 h (P<0.01) and 12 h (P<0.05), but the expression level of LvLectin-1 down-regulated significantly (P<0.01) to 0.4-fold at 6 and 12 h post-stimulation. The results indicated that the two C-type lectins might be involved in immune response toward pathogen infection, and they might perform different recognition specificity toward bacteria or virus. Copyright © 2011

Avian and human influenza A virus receptors in trachea and lung of animals.

PubMed

Thongratsakul, Sukanya; Suzuki, Yasuo; Hiramatsu, Hiroaki; Sakpuaram, Thavajchai; Sirinarumitr, Theerapol; Poolkhet, Chaithep; Moonjit, Pattra; Yodsheewan, Rungrueang; Songserm, Thaweesak

2010-12-01

Influenza A viruses are capable of crossing the specific barrier between human beings and animals resulting in interspecies transmission. The important factor of potential infectivity of influenza A viruses is the suitability of the receptor binding site of the host and viruses. The affinities of avian and human influenza virus to bind with the receptors and the distributions of receptors in animals are different. This study aims to investigate the anatomical distribution of avian and human influenza virus receptors using the double staining lectin histochemistry method. Double staining of lectin histochemistry was performed to identify both SA alpha2,3 Gal and SA alpha2,6 Gal receptors in trachea and lung tissue of dogs, cats, tigers, ferret, pigs, ducks and chickens. We have demonstrated that avian and human influenza virus receptors were abundantly present in trachea, bronchus and bronchiole, but in alveoli of dogs, cats and tigers showed SA alpha2,6 Gal only. Furthermore, endothelial cells in lung tissues showed presence of SA alpha2,3 Gal. The positive sites of both receptors in respiratory tract, especially in the trachea, suggest that all mammalian species studied can be infected with avian influenza virus. These findings suggested that dogs and cats in close contact with humans should be of greater concern as an intermediate host for avian influenza A in which there is the potential for viral adaptation and reassortment.

Structure of Epstein-Barr Virus Glycoprotein 42 Suggests a Mechanism for Triggering Receptor-Activated Virus Entry

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

Kirschner, Austin N.; Sorem, Jessica; Longnecker, Richard

Epstein-Barr virus requires glycoproteins gH/gL, gB, and gp42 to fuse its lipid envelope with B cells. Gp42 is a type II membrane protein consisting of a flexible N-terminal region, which binds gH/gL, and a C-terminal lectin-like domain that binds to the B-cell entry receptor human leukocyte antigen (HLA) class II. Gp42 triggers membrane fusion after HLA binding, a process that requires simultaneous binding to gH/gL and a functional hydrophobic pocket in the lectin domain adjacent to the HLA binding site. Here we present the structure of gp42 in its unbound form. Comparisons to the previously determined structure of a gp42:HLAmore » complex reveals additional N-terminal residues forming part of the gH/gL binding site and structural changes in the receptor binding domain. Although the core of the lectin domain remains similar, significant shifts in two loops and an {alpha} helix bordering the essential hydrophobic pocket suggest a structural mechanism for triggering fusion.« less

Laccase and lectin activities of intracellular proteins produced in a submerged culture of the xylotrophic basidiomycete Lentinus edodes.

PubMed

Vetchinkina, Elena P; Pozdnyakova, Natalia N; Nikitina, Valentina E

2008-10-01

The white-rot fungus Lentinus edodes produced D-melibiose-specific lectins and two laccase forms in a lignin-containing medium. The maxima of laccase and lectin activities coincided, falling within the period of active mycelial growth. The enzymes and lectins were isolated and purified by gel filtration followed by anion-exchange chromatography. The L. edodes lectins were found to be able to stabilize the activity of the fungus's own laccases. Lectin activity during the formation of lectin-enzyme complexes remained unchanged.

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

Purification and characterization of a mucin specific mycelial lectin from Aspergillus gorakhpurensis: application for mitogenic and antimicrobial activity.

PubMed

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

2014-01-01

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. 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. 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. This is the first report on the mitogenic and antimicrobial potential of Aspergillus gorakhpurensis lectin. The

Mechanisms of lectin and antibody-dependent polymorphonuclear leukocyte-mediated cytolysis.

PubMed

Tsunawaki, S; Ikenami, M; Mizuno, D; Yamazaki, M

1983-04-01

The mechanisms of tumor lysis by polymorphonuclear leukocytes (PMNs) were investigated. In antibody-dependent PMN-mediated cytolysis (ADPC), sensitized tumor cells were specifically lysed via Fc receptors on PMNs. On the other hand, lectin-dependent PMN-mediated cytolysis (LDPC) caused nonspecific lysis of several murine tumors after recognition of carbohydrate moieties on the cell membrane of both PMNs and tumor cells. Both ADPC and LDPC depended on glycolysis, and cytotoxicity was mediated by reactive oxygen species; LDPC was dependent on superoxide and ADPC on the myeloperoxidase system. The participation of reactive oxygen species in PMN cytotoxicity was also demonstrated by pharmacological triggering with phorbol myristate acetate. These results indicate that reactive oxygen species have an important role In tumor killing by PMNs and that ADPC and LDPC have partly different cytolytic processes as well as different recognition steps.

Developmental changes in the distribution of cecal lectin-binding sites of Balb-c mice.

PubMed

Doehrn, S; Breipohl, W; Lierse, W; Romaniuk, K; Young, W

1992-01-01

The existence of lectin-binding sites was investigated in the cecum of Balb-c mice at seven developmental stages ranging from 18 days post conception (p.c.) to 8 weeks after birth. Nine horseradish-peroxidase-conjugated lectins (concanavalin A, Triticum vulgaris, Dolichus biflorus, Helix pomatia, Arachis hypogaea, Glycine maximus, Lotus tetragonolobus, Ulex europaeus, Limulus polyphemus) were applied to 5- to 7-microns thin paraffin sections of Bouin-fixed tissue. After DAB staining the sections were evaluated by light microscopy. It was shown that each lectin exhibits a unique developmental pattern. The adult binding patterns were established at the age of 3-4 weeks with only minor changes occurring thereafter. Considerable differences in binding patterns occurred not only between lectins of different groups but also between lectins with the same nominal monosaccharide specificity.

Antimicrobial lectin from Schinus terebinthifolius leaf.

PubMed

Gomes, F S; Procópio, T F; Napoleão, T H; Coelho, L C B B; Paiva, P M G

2013-03-01

Schinus terebinthifolius leaves are used for treating human diseases caused by micro-organisms. This work reports the isolation, characterization and antimicrobial activity of S. terebinthifolius leaf lectin (SteLL). The isolation procedure involved protein extraction with 0.15 mol l(-1) NaCl, filtration through activated charcoal and chromatography of the filtrate on a chitin column. SteLL is a 14-kDa glycopeptide with haemagglutinating activity that is inhibited by N-acetyl-glucosamine, not affected by ions (Ca(2+) and Mg(2+)) and stable upon heating (30-100 °C) as well as over the pH 5.0-8.0. The antimicrobial effect of SteLL was evaluated by determining the minimal inhibitory (MIC), bactericide (MBC) and fungicide (MFC) concentrations. Lectin was active against Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella enteritidis and Staphylococcus aureus. Highest bacteriostatic and bactericide effects were detected for Salm. enteritidis (MIC: 0.45 μg ml(-1)) and Staph. aureus (MBC: 7.18 μg ml(-1)), respectively. SteLL impaired the growth (MIC: 6.5 μg ml(-1)) and survival (MFC: 26 μg ml(-1)) of Candida albicans. SteLL, a chitin-binding lectin, purified in milligram quantities, showed antimicrobial activity against medically important bacteria and fungi. SteLL can be considered as a new biomaterial for potential antimicrobial applications. © 2012 The Society for Applied Microbiology.

High molecular weight lectin isolated from the mucus of the giant African snail Achatina fulica.

PubMed

Ito, Shigeru; Shimizu, Masahiro; Nagatsuka, Maki; Kitajima, Seiji; Honda, Michiyo; Tsuchiya, Takahide; Kanzawa, Nobuyuki

2011-01-01

To understand better the host defense mechanisms of mollusks against pathogens, we examined the anti-microbial activity of mucus from the giant African snail Achatina fulica. Hemagglutination activity of the mucus secreted by the integument of snails inoculated with Escherichia coli was observed to increase and to cause hemagglutination of rabbit red blood cells. Purification of the snail mucus lectin by sequential column chromatography revealed that the relative molecular mass of the lectin was 350 kDa. The hemagglutination activity of the lectin was Ca(2+)-dependent and was inhibited by galactose. Growth arrest tests showed that the lectin did not inhibit bacterial growth, but did induce agglutination of gram-positive and gram-negative bacteria. Tissue distribution analyses using a polyclonal antibody revealed that the lectin was expressed in the tissues of the mantle collar. The lectin isolated from the mucus of the snail appeared to contribute to its innate immunity.

Enhancement of anti-Aeromonas salmonicida activity in Atlantic salmon (Salmo salar) macrophages by a mannose-binding lectin

USGS Publications Warehouse

Ottinger, C.A.; Johnson, S.C.; Ewart, K.V.; Brown, L.L.; Ross, N.W.

1999-01-01

We investigated the effects of a calcium-dependent mannose-binding lectin isolated from the serum of Atlantic salmon on Aeromonassalmonicida viability and the anti-A. salmonicida activity of Atlantic salmon macrophages. In the absence of other factors, binding of this lectin at concentrations of 0.8, 4.0 and 20.0 ng ml−1 to virulent A. salmonicida failed to significantly reduce (P>0.05) cell viability. However, binding of the lectin to A. salmonicida did result in significant (P≤0.05) dose-dependent increases in phagocytosis, and bactericidal activity. Significant increases (P≤0.05) were also observed in phagocyte respiratory burst activity within the lectin concentration range of 4.0–20.0 ng ml−1 but the stimulation was not dose dependent at these lectin concentrations. At the lowest lectin concentration tested (0.32 ng ml−1), a significant decrease (P≤0.05) in respiratory burst was observed. The structure and activity of this lectin are similar to that of mammalian mannose-binding lectins, which are known to play a pivotal role in innate immunity. The presence of this lectin may be an important defense mechanism against Gram-negative bacteria such as A. salmonicida.

Fluorescent carbohydrate probes for cell lectins

NASA Astrophysics Data System (ADS)

Galanina, Oxana; Feofanov, Alexei; Tuzikov, Alexander B.; Rapoport, Evgenia; Crocker, Paul R.; Grichine, Alexei; Egret-Charlier, Marguerite; Vigny, Paul; Le Pendu, Jacques; Bovin, Nicolai V.

2001-09-01

Fluorescein labeled carbohydrate (Glyc) probes were synthesized as analytical tools for the study of cellular lectins, i.e. SiaLe x-PAA-flu, Sia 2-PAA-flu, GlcNAc 2-PAA-flu, LacNAc-PAA-flu and a number of similar ones, with PAA a soluble polyacrylamide carrier. The binding of SiaLe x-PAA-flu was assessed using CHO cells transfected with E-selectin, and the binding of Sia 2-PAA-flu was assessed by COS cells transfected with siglec-9. In flow cytometry assays, the fluorescein probes demonstrated a specific binding to the lectin-transfected cells that was inhibited by unlabeled carbohydrate ligands. The intense binding of SiaLe x-PAA- 3H to the E-selectin transfected cells and the lack of binding to both native and permeabilized control cells lead to the conclusion that the polyacrylamide carrier itself and the spacer arm connecting the carbohydrate moiety with PAA did not contribute anymore to the binding. Tumors were obtained from nude mice by injection of CHO E-selectin or mock transfected cells. The fluorescent SiaLe x-PAA-flu probe could bind to the tumor sections from E-selectin positive CHO cells, but not from the control ones. Thus, these probes can be used to reveal specifically the carbohydrate binding sites on cells in culture as well as cells in tissue sections. The use of the confocal spectral imaging technique with Glyc-PAA-flu probes offered the unique possibility to detect lectins in different cells, even when the level of lectin expression was rather low. The confocal mode of spectrum recording provided an analysis of the probe localization with 3D submicron resolution. The spectral analysis (as a constituent part of the confocal spectral imaging technique) enabled interfering signals of the probe and intrinsic cellular fluorescence to be accurately separated, the distribution of the probe to be revealed and its local concentration to be measured.

Selective binding of lectins to normal and neoplastic urothelium in rat and mouse bladder carcinogenesis models.

PubMed

Zupančič, 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.

Glycome Diagnosis of Human Induced Pluripotent Stem Cells Using Lectin Microarray*

PubMed Central

Tateno, Hiroaki; Toyota, Masashi; Saito, Shigeru; Onuma, Yasuko; Ito, Yuzuru; Hiemori, Keiko; Fukumura, Mihoko; Matsushima, Asako; Nakanishi, Mio; Ohnuma, Kiyoshi; Akutsu, Hidenori; Umezawa, Akihiro; Horimoto, Katsuhisa; Hirabayashi, Jun; Asashima, Makoto

2011-01-01

Induced pluripotent stem cells (iPSCs) can now be produced from various somatic cell (SC) lines by ectopic expression of the four transcription factors. Although the procedure has been demonstrated to induce global change in gene and microRNA expressions and even epigenetic modification, it remains largely unknown how this transcription factor-induced reprogramming affects the total glycan repertoire expressed on the cells. Here we performed a comprehensive glycan analysis using 114 types of human iPSCs generated from five different SCs and compared their glycomes with those of human embryonic stem cells (ESCs; nine cell types) using a high density lectin microarray. In unsupervised cluster analysis of the results obtained by lectin microarray, both undifferentiated iPSCs and ESCs were clustered as one large group. However, they were clearly separated from the group of differentiated SCs, whereas all of the four SCs had apparently distinct glycome profiles from one another, demonstrating that SCs with originally distinct glycan profiles have acquired those similar to ESCs upon induction of pluripotency. Thirty-eight lectins discriminating between SCs and iPSCs/ESCs were statistically selected, and characteristic features of the pluripotent state were then obtained at the level of the cellular glycome. The expression profiles of relevant glycosyltransferase genes agreed well with the results obtained by lectin microarray. Among the 38 lectins, rBC2LCN was found to detect only undifferentiated iPSCs/ESCs and not differentiated SCs. Hence, the high density lectin microarray has proved to be valid for not only comprehensive analysis of glycans but also diagnosis of stem cells under the concept of the cellular glycome. PMID:21471226

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

New GlcNAc/GalNAc-specific lectin from the ascidian Didemnum ternatanum.

PubMed

Molchanova, Valentina; Chikalovets, Irina; Li, Wei; Kobelev, Stanislav; Kozyrevskaya, Svetlana; Bogdanovich, Raisa; Howard, Eric; Belogortseva, Natalia

2005-05-25

Previously we isolated GlcNAc-specific lectin (DTL) from the ascidian Didemnum ternatanum by affinity chromatography on cross-linked ovalbumin. Here we report the purification and characterization of new D-GlcNAc/D-GalNAc-specific lectin DTL-A from the same ascidian. This lectin was isolated from non-bound cross-linked ovalbumin fraction and further was purified by gel filtration on Sepharose CL-4B, affinity chromatography on GlcNAc-agarose and gel filtration on Superdex 200. SDS-polyacrylamide gel electrophoresis and gel filtration of purified lectin on Sepharose CL-4B indicates that it exists as large aggregates in the native state. Investigations of the carbohydrate specificity of DTL-A by enzyme-linked lectin assay suggest the multi-specificity of this lectin. DTL-A binds BSM, asialo-BSM as well as heparin and dextran sulfate. The binding of DTL-A to BSM was inhibited by monosaccharides D-GlcNAc and D-GalNAc, their alpha- but not beta-anomers. Among polysaccharides and glycoconjugates, DTL-A binding to BSM was effectively inhibited by BSM, asialo-BSM, pronase-treated BSM and synthetic alpha-D-GalNAc-PAA. Fetuin and asialofetuin showed a much lower inhibitory potency, heparin and dextran sulfate were noninhibitory. On the other hand, DTL-A binding to heparin was effectively inhibited by dextran sulfate, fucoidan, whereas BSM showed insignificantly inhibitory effect. DTL-A binding to heparin was not inhibited by D-GlcNAc and D-GalNAc.

[Lectins from Sambucus nigra L inflorescences: isolation and investigation of biological activity using procaryotic test-systems].

PubMed

Karpova, I S; Korets'ka, N V; Pal'chykovs'ka, L H; Nehruts'ka, V V

2007-01-01

Isolation of lectins from extracts of the Sambucus nigra inflorescences and of pollen material have been performed using isoelectric focusing without carrier ampholytes (autofocusing). Fractions active in agglutination tests with different carbohydrate specificity were subjected to SDS-PAGE. The major lectin found in whole inflores-cences was GalNAc specific and is proposed to be a heterotetramer with subunits of about 30 and 33 kDa. It was called SNAflu-I. At least two other lectins were present in the pollen material and supposed to consist of identical subunits. Major positively charged lectin was Glc/Man specific with subunit of 26 kDa and called SNApol-I. Other pollen component (SNApol-II) was Gal specific with subunit of about 20 kDa. In order to elucidate cell targets sensitive for the S. nigra lectin's activity the combined effects of the lectins and transcriptional of phenazine origin on B. subtilis cells growth have been studied. Only SNApol-I demonstrated the antagonistic activity against these inhibitors in vivo. This lectin but not the SNAflu-I can also inhibit transcription in vitro. It is supposed that lectins from the same source may act in different directions on cell metabolism. Particularly one of the common targets may be the DNA-dependent synthesis of RNA.

The glycoconjugate sugar residues of the sessile and motile cells in the thymus of normal and cyclosporin-A-treated rats: lectin histochemistry.

PubMed

Gheri, G; Gheri Bryk, S; Riccardi, R; Sgambati, E; Cirri Borghi, M B

2002-01-01

It is well known that cell surface glycoconjugates play a determinant role in cellular recognition, cell-to-cell adhesion and serve as receptor molecules. T-lymphocytes are in strict contact with the thymic epithelial cells, which control their process of maturation and proliferation. On the other hand the normal maturation of the epithelial cells is believed to be induced by T-lymphocytes. For these reasons we have studied the glycoconjugates saccharidic moieties of the sessile and motile cells in the thymus of normal male albino Wistar rats and their changes following cyclosporin-A treatment, using a battery of seven HRP-lectins. Cytochemical controls were performed for specificity of lectin-sugar reaction. Some sections were pre-treated with neuraminidase prior to staining with HRP-lectins. Our results have demonstrated, in the control rats, a large amount and a variety of terminal and subterminal oligosaccharides within and/or on the epithelial thymic cells and in macrophages. After cyclosporin-A treatment, among the thymic epithelial cells, the subcapsular, paraseptal and perivascular cells showed the loss of some sugar residues, which characterized the same cells in the intact thymus. Some hypotheses are reported on the role played by the glycoconjugate sugar residues in control and cyclosporin-A treated rats.

Purification and Characterization of Two Major Lectins from Araucaria brasiliensis syn. Araucaria angustifolia Seeds (Pinhão) 1

PubMed Central

Datta, Pradip K.; Figueroa, Maria O. D. C. R.; Lajolo, Franco M.

1991-01-01

Two major lectins (lectin I and lectin II) were purified to homogeneity from the seeds of Araucaria brasiliensis (Gymnospermae). The purity of the lectins was confirmed by polyacrylamide gel electrophoresis, isoelectric focusing, and high performance liquid chromatography. They are glycoproteins in nature containing 6.3 and 2.9%, respectively, of neutral sugar and have absorption coefficients of 3.8 and 4.7, respectively, at 280 nanometers. The molecular weights of both lectins obtained by gel filtration on Sephacryl S-400 were equal: 200,000. After dissociation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, molecular weights were 20,000 and 34,000, respectively, for lectin I and lectin II, suggesting they are decameric and hexameric in nature. The amino acid composition of both lectins showed little difference, but both had high amounts of acidic amino acids and lacked methionine in their molecule. The carbohydrate binding specificity of lectins was directed towards mannose, glucose, and their oligomers. High inhibitory activity was also found with thyroglobulin. The erythroagglutinating activity of the lectins was enhanced in the presence of high-molecular-weight substances both at 37 and 4°C. Divalent cations do not appear to be essential for activity. They maintained their agglutinating activity over a broad but different range of pH: 5.5 to 7.5 and 6.5 to 7.5, respectively. Both lectins agglutinated erythrocytes of human ABO blood types equally well. ImagesFigure 2Figure 3 PMID:16668523

Anti-insect potential of lectins from Arisaema species towards Bactrocera cucurbitae.

PubMed

Kaur, Manpreet; Singh, Kuljinder; Rup, Pushpinder J; Kamboj, Sukhdev Singh; Singh, Jatinder

2009-11-01

Bactrocera cucurbitae (Coquillett), also known as melon fruit fly, is one of the major insect pests of cucurbits in several parts of Asia, Africa and Pacific. In the present investigation, effect of lectins from two sources i.e. Arisaema intermedium Blume and Arisaema wallichianum Hook f. (Family-Araceae) has been studied on the development of second instar larvae of melon fruit fly. The lectins were incorporated separately in artificial diet at a concentration of 10 to 160 microg ml(-1) and fed adlibitum to the second instar larvae. Both the lectins were found to prolong the development period and significantly inhibited the pupation and emergence in a dose dependent manner. Total development period was found to be prolonged by 3.5 and 2.3 days in case of larvae fed on artificial diet containing A. intermedium (AIL) and A. wallichianum (AWL), respectively. LC50 values calculated on the basis of adult emergence came out to be 32.8 and 29 microg ml(-1) for AIL and AWL, respectively. Both the lectins tested, were found to increase the activity of esterases as larvae proceeded from 24 to 72 hr of treatment. The activity of acid phosphatase decreased significantly in larvae reared on diet containing LC50 of AIL, while in case of AWL significant decrease was observed only at 72 hr of treatment. Alkaline phosphatase activity decreased significantly on treatment with both of these lectins. These results showed that AIL and AWL have promising anti-insect potential. So, lectin gene/s from either of these species can be cloned and subsequently can be employed to develop transgenics to control melon fruit flies specifically and insect pests in general. This approach could be used as a part of Integrated pest management (IPM) strategies.

Current V3 genotyping algorithms are inadequate for predicting X4 co-receptor usage in clinical isolates.

PubMed

Low, Andrew J; Dong, Winnie; Chan, Dennison; Sing, Tobias; Swanstrom, Ronald; Jensen, Mark; Pillai, Satish; Good, Benjamin; Harrigan, P Richard

2007-09-12

Integrating CCR5 antagonists into clinical practice would benefit from accurate assays of co-receptor usage (CCR5 versus CXCR4) with fast turnaround and low cost. Published HIV V3-loop based predictors of co-receptor usage were compared with actual phenotypic tropism results in a large cohort of antiretroviral naive individuals to determine accuracy on clinical samples and identify areas for improvement. Aligned HIV envelope V3 loop sequences (n = 977), derived by bulk sequencing were analyzed by six methods: the 11/25 rule; a neural network (NN), two support vector machines, and two subtype-B position specific scoring matrices (PSSM). Co-receptor phenotype results (Trofile Co-receptor Phenotype Assay; Monogram Biosciences) were stratified by CXCR4 relative light unit (RLU) readout and CD4 cell count. Co-receptor phenotype was available for 920 clinical samples with V3 genotypes having fewer than seven amino acid mixtures (n = 769 R5; n = 151 X4-capable). Sensitivity and specificity for predicting X4 capacity were evaluated for the 11/25 rule (30% sensitivity/93% specificity), NN (44%/88%), PSSM(sinsi) (34%/96%), PSSM(x4r5) (24%/97%), SVMgenomiac (22%/90%) and SVMgeno2pheno (50%/89%). Quantitative increases in sensitivity could be obtained by optimizing the cut-off for methods with continuous output (PSSM methods), and/or integrating clinical data (CD4%). Sensitivity was directly proportional to strength of X4 signal in the phenotype assay (P < 0.05). Current default implementations of co-receptor prediction algorithms are inadequate for predicting HIV X4 co-receptor usage in clinical samples, particularly those X4 phenotypes with low CXCR4 RLU signals. Significant improvements can be made to genotypic predictors, including training on clinical samples, using additional data to improve predictions and optimizing cutoffs and increasing genotype sensitivity.

Enteral exposure to crude red kidney bean lectin induces maturation of the gut in suckling pigs.

PubMed

Rådberg, K; Biernat, M; Linderoth, A; Zabielski, R; Pierzynowski, S G; Weström, B R

2001-10-01

The present investigation characterized the effect of red kidney bean lectin exposure on gut maturation and function in young piglets. Eleven suckling pigs were given by stomach tube a crude red kidney bean lectin preparation (containing about 25% lectin, 400 mg/kg BW) (lectin-treated pigs) at 10, 11, and 12 d of life, and an additional 16 pigs (control pigs) were given saline instead. On the next day, the intestinal absorptive capacity was determined in vivo, and on the 14th d of life the piglets were killed and organs and small intestine samples were collected for analyses and in vitro permeability experiments. The lectin-treated pigs showed an increase in stomach weights and mucosa thickness, whereas no weight effect was found for the small intestine, spleen, liver, or adrenals. Morphometric analyses of the small intestine in lectin-treated pigs showed a decrease in villus heights, an increase in crypt depths and crypt cell mitotic indices, and fewer vacuolated enterocytes per villus and reduced vacuole size. Lectin treatment also resulted in a decrease in the absorption of different-sized marker molecules after gavage feeding, a decrease in intestinal marker permeability, and a change in small intestinal disaccharidase activities, with increased maltase and sucrase activities. The size of the pancreatic acini was also greater in the lectin-treated pigs, but no increases in enzyme content or pancreatic weight could be determined. In addition, the blood plasma levels of cholecystokinin were higher in the lectin-treated than in the control pigs. The results indicate that exposure to crude red kidney bean lectin induces structural and functional maturation of the gut and pancreatic growth in young suckling piglets. This possibility of inducing gut maturation may lead to an improvement in the piglets' ability to adapt to weaning and to an increase in the growth and health of these animals.

Synthesis and optimization of lectin functionalized nanoprobes for the selective recovery of glycoproteins from human body fluids.

PubMed

Ferreira, José A; Daniel-da-Silva, Ana Luísa; Alves, Renato M P; Duarte, Daniel; Vieira, Igor; Santos, Lúcio Lara; Vitorino, Rui; Amado, Francisco

2011-09-15

Biomedical sciences, and in particular biomarker research, demand efficient glycoprotein enrichment platforms. Herein magnetic nanoprobes (MNP), after being coated with three broad-spectrum lectins-concanavalin A (ConA), wheat germ agglutinin (WGA), and Maackia amurensis lectin (MA)-were utilized to selectively capture glycoproteins from human body fluids. Additionally, a new methodology, based on protection of the lectins with their target sugars prior to coupling with MNPs, was proposed to overcome the nonspecific nature of conjugation. This approach contributed to preserve lectin conformation, increasing by 40% and 90% the affinity of ConA and MA for glycoproteins in relation to synthesis with nonprotected lectins. Optimal operating conditions (temperature, time) and maximum binding capacities were further determined for each lectin by use of fetuin as a reference. The enhanced performance of lectin-based nanoplatforms was demonstrated by comparing MNP@ConA with conventional Sepharose@ConA. These experiments have shown that ConA immobilized on MNP exhibited 5 times higher affinity for fetuin and ovalbumin when compared with Sepharose@ConA with the same amount of immobilized lectin. MNP@Lectins were then applied to human serum, saliva, and urine and the recovered proteins were digested with trypsin and analyzed by nano-HPLC MALDI-TOF/TOF. This allowed the identification of 180 proteins, 90% of which were found to be glycosylated by use of bioinformatics tools, therefore revealing low levels of unspecific binding. Thus, MNP@lectins have proved to be a valuable tool for glycoproteomic studies, particularly when dealing with minute amounts of material.

Effects of environmental factors on C-type lectin recognition to zooxanthellae in the stony coral Pocillopora damicornis.

PubMed

Zhou, Zhi; Zhao, Shuimiao; Ni, Junyi; Su, Yilu; Wang, Lingui; Xu, Yanlai

2018-08-01

C-type lectin is a superfamily of Ca 2+ -dependent carbohydrate-recognition proteins that play significant roles in nonself-recognition and pathogen clearance. In the present study, a C-type lectin (PdC-Lectin) was chosen from stony coral Pocillopora damicornis to understand its recognition characteristics to zooxanthellae. PdC-Lectin protein contained a signal peptide and a carbohydrate-recognition domain with EPN motif in Ca 2+ -binding site 2. The PdC-Lectin recombinant protein was expressed and purified in vitro. The binding of PdC-Lectin protein to zooxanthellae was determined with western blotting method, and the bound protein to 10-10 5  cell mL -1 zooxanthellae was detectable in a concentration-dependent manner. Less PdC-Lectin protein binding to zooxanthellae was observed for the incubation at 36 °C than that at 26 °C. Furthermore, the PAMP recognition spectrum of PdC-Lectin protein was tested through surface plasmon resonance method, and it bound to LPS and Lipid A, but not to LTA, β-glucan, mannose or Poly (I:C). When PdC-Lectin protein was preincubated with LPS, there was less protein binding to zooxanthellae compared with that in non-preincubation group. These results collectively suggest that PdC-Lectin could recognize zooxanthellae, and the recognition could be repressed by high temperature and pathogenic bacteria, which would help to further understand the molecular mechanism of coral bleaching and the establishment of coral-zooxanthella symbiosis in the stony coral P. damicornis. Copyright © 2018 Elsevier Ltd. All rights reserved.

Carbohydrate binding specificity of pea lectin studied by NMR spectroscopy and molecular dynamics simulations

NASA Astrophysics Data System (ADS)

Cheong, Youngjoo; Shim, Gyuchang; Kang, Dongil; Kim, Yangmee

1999-02-01

The conformational details of Man( α1,6)Man( α)OMe are investigated through NMR spectroscopy in conjunction with molecular modeling. The lowest energy structure (M1) in the adiabatic energy map calculated with a dielectric constant of 50 has glycosidic dihedral angles of φ=-60°, ψ=180° and ω=180°. The other low energy structure (M2) has glycosidic dihedral angles of φ=-60°, ψ=180° and ω=-60°. Molecular dynamics simulations and NMR experiments prove that Man( α1,6)Man( α)OMe in the free form exists with conformational averaging of M1 and M2 conformers predominantly. Molecular dynamics simulations of the pea lectin-carbohydrate complex with explicit water molecules starting from the X-ray crystallographic structure of pea lectin show that the protein-carbohydrate interaction centers mainly on the hydrogen bonds and van der Waals interactions between protein and carbohydrate. From the molecular dynamics simulation, it is found that the M1 structure can bind to pea lectin better than the M2 structure. The origin of this selectivity is the water- mediated hydrogen bond interactions between the remote mannose and the binding site of pea lectin as well as the direct hydrogen bond interaction between the terminal mannose and pea lectin. Extensive networks of interactions in the carbohydrate binding site and the metal binding site are important in maintaining the carbohydrate binding properties of pea lectin. Especially, the predominant factors of mannose binding specificity of pea lectin are the hydrogen bond interactions between the 4th hydroxyl groups of the terminal sugar ring and the side chains of Asp-81 and Asn-125 in the carbohydrate binding site, and the additional interactions between these side chains of Asp-81 and Asn-125 and the calcium ion in the metal binding site of pea lectin.

Functional Mapping of the Lectin Activity Site on the β-Prism Domain of Vibrio cholerae Cytolysin

PubMed Central

Rai, Anand Kumar; Paul, Karan; Chattopadhyay, Kausik

2013-01-01

Vibrio cholerae cytolysin (VCC) is a prominent member in the family of β-barrel pore-forming toxins. It induces lysis of target eukaryotic cells by forming transmembrane oligomeric β-barrel channels. VCC also exhibits prominent lectin-like activity in interacting with β1-galactosyl-terminated glycoconjugates. Apart from the cytolysin domain, VCC harbors two lectin-like domains: the β-Trefoil and the β-Prism domains; however, precise contribution of these domains in the lectin property of VCC is not known. Also, role(s) of these lectin-like domains in the mode of action of VCC remain obscure. In the present study, we show that the β-Prism domain of VCC acts as the structural scaffold to determine the lectin activity of the protein toward β1-galactosyl-terminated glycoconjugates. Toward exploring the physiological implication of the β-Prism domain, we demonstrate that the presence of the β-Prism domain-mediated lectin activity is crucial for an efficient interaction of the toxin toward the target cells. Our results also suggest that such lectin activity may act to regulate the oligomerization ability of the membrane-bound VCC toxin. Based on the data presented here, and also consistent with the existing structural information, we propose a novel mechanism of regulation imposed by the β-Prism domain's lectin activity, implicated in the process of membrane pore formation by VCC. PMID:23209283

Fluorescence Lectin Bar-Coding of Glycoconjugates in the Extracellular Matrix of Biofilm and Bioaggregate Forming Microorganisms.

PubMed

Neu, Thomas R; Kuhlicke, Ute

2017-02-10

Microbial biofilm systems are defined as interface-associated microorganisms embedded into a self-produced matrix. The extracellular matrix represents a continuous challenge in terms of characterization and analysis. The tools applied in more detailed studies comprise extraction/chemical analysis, molecular characterization, and visualisation using various techniques. Imaging by laser microscopy became a standard tool for biofilm analysis, and, in combination with fluorescently labelled lectins, the glycoconjugates of the matrix can be assessed. By employing this approach a wide range of pure culture biofilms from different habitats were examined using the commercially available lectins. From the results, a binary barcode pattern of lectin binding can be generated. Furthermore, the results can be fine-tuned and transferred into a heat map according to signal intensity. The lectin barcode approach is suggested as a useful tool for investigating the biofilm matrix characteristics and dynamics at various levels, e.g. bacterial cell surfaces, adhesive footprints, individual microcolonies, and the gross biofilm or bio-aggregate. Hence fluorescence lectin bar-coding (FLBC) serves as a basis for a subsequent tailor-made fluorescence lectin-binding analysis (FLBA) of a particular biofilm. So far, the lectin approach represents the only tool for in situ characterization of the glycoconjugate makeup in biofilm systems.  Furthermore, lectin staining lends itself to other fluorescence techniques in order to correlate it with cellular biofilm constituents in general and glycoconjugate producers in particular.

Lineage-specific co-evolution of the Egf receptor/ligand signaling system.

PubMed

Laisney, Juliette A G C; Braasch, Ingo; Walter, Ronald B; Meierjohann, Svenja; Schartl, Manfred

2010-01-27

The epidermal growth factor receptor (Egfr) with its numerous ligands has fundamental roles in development, cell differentiation and physiology. Dysfunction of the receptor-ligand system contributes to many human malignancies. Consistent with such various tasks, the Egfr gene family has expanded during vertebrate evolution as a consequence of several rounds of whole genome duplication. Of particular interest is the effect of the fish-specific whole genome duplication (FSGD) on the ligand-receptor system, as it has supplied this largest group of vertebrates with additional opportunities for sub- and/or neofunctionalization in this signaling system. We identified the predicted components of the Egf receptor-ligand signaling system in teleost fishes (medaka, platyfish, stickleback, pufferfishes and zebrafish). We found two duplicated egfr genes, egfra and egfrb, in all available teleost genomes. Surprisingly only one copy for each of the seven Egfr ligands could be identified in most fishes, with zebrafish hbegf being the only exception. Special focus was put on medaka, for which we more closely investigated all Egf receptors and Egfr ligands. The different expression patterns of egfra, egfrb and their ligands in medaka tissues and embryo stages suggest differences in role and function. Preferential co-expression of different subsets of Egfr ligands corroborates the possible subfunctionalization and specialization of the two receptors in adult tissues. Bioinformatic analyses of the ligand-receptor interface between Egfr and its ligands show a very weak evolutionary conservation within this region. Using in vitro analyses of medaka Egfra, we could show that this receptor is only activated by medaka ligands, but not by human EGF. Altogether, our data suggest a lineage-specific Egfr/Egfr ligand co-evolution. Our data indicate that medaka Egfr signaling occurs via its two copies, Egfra and Egfrb, each of them being preferentially coexpressed with different subsets of Egfr

Lineage-specific co-evolution of the Egf receptor/ligand signaling system

PubMed Central

2010-01-01

Background The epidermal growth factor receptor (Egfr) with its numerous ligands has fundamental roles in development, cell differentiation and physiology. Dysfunction of the receptor-ligand system contributes to many human malignancies. Consistent with such various tasks, the Egfr gene family has expanded during vertebrate evolution as a consequence of several rounds of whole genome duplication. Of particular interest is the effect of the fish-specific whole genome duplication (FSGD) on the ligand-receptor system, as it has supplied this largest group of vertebrates with additional opportunities for sub- and/or neofunctionalization in this signaling system. Results We identified the predicted components of the Egf receptor-ligand signaling system in teleost fishes (medaka, platyfish, stickleback, pufferfishes and zebrafish). We found two duplicated egfr genes, egfra and egfrb, in all available teleost genomes. Surprisingly only one copy for each of the seven Egfr ligands could be identified in most fishes, with zebrafish hbegf being the only exception. Special focus was put on medaka, for which we more closely investigated all Egf receptors and Egfr ligands. The different expression patterns of egfra, egfrb and their ligands in medaka tissues and embryo stages suggest differences in role and function. Preferential co-expression of different subsets of Egfr ligands corroborates the possible subfunctionalization and specialization of the two receptors in adult tissues. Bioinformatic analyses of the ligand-receptor interface between Egfr and its ligands show a very weak evolutionary conservation within this region. Using in vitro analyses of medaka Egfra, we could show that this receptor is only activated by medaka ligands, but not by human EGF. Altogether, our data suggest a lineage-specific Egfr/Egfr ligand co-evolution. Conclusions Our data indicate that medaka Egfr signaling occurs via its two copies, Egfra and Egfrb, each of them being preferentially coexpressed

Lectins in fruits having gastrointestinal activity: their participation in the hemagglutinating property of Escherichia coli O157:H7.

PubMed

Coutiño-Rodríguez, R; Hernández-Cruz, P; Giles-Ríos, H

2001-01-01

In fruits with therapeutic properties for antidiarrheal and laxative uses, the presence of lectins may be the bioactive properties that interfere with bacterial adhesion, thought to be competition for glycoside signal sites in the attachment. This study identifies lectins in crude extracts from fruits such as Tamarindus indica (tamarind), Spontia vulgaris (plum), Psidium guava (guava), Mangifera indica (mango), Cydonia vulgaris (quince), and Crataegus mexicanus (tejocote). To verify the procedures, extracts from Ricinus communis (castor bean), Glycine max (soybean), Phaseolus vulgaris (beans), Vicia fava (fava bean), and Solanum tuberosum (potato) were used as controls for lectin activity. Both sources of lectins were analyzed to determine their participation in the host-parasite interaction, using as a model the hemagglutinating properties of Escherichia coli O157:H7 (EHA). All extracts showed hemagglutination to group O erythrocytes test (HA) with the exception of mango. Two new galactose-specific lectins were identified from tamarind and guava. When analyzed for participation in EHA, only guava lectins inhibited this, while soybean lectin induced hemolysis; as both lectins bind to galactose, it is probable that their recognition occurs in different domains. Sugars involved in the attachment between Escherichia coli O157:H7 and red cells were identified and again, galactose in addition to mannose was found to be related in EHA. On the other hand, guava lectins also agglutinated E. coli O157:H7, perhaps due to the same galactose-specific lectin or to another type of lectin. In summary, guava has a galactose-specific lectin that prevents adhesion of E. coli O157:H7 to red cells; this lectin is mediated by galactose. Prevention could also be due to their capacity of agglutinating E. coli by guava lectins. Soybean lectin induced hemolysis only when bacteria was present, but not with floating secretions. This finding showed that guava is a source of lectin that can be

The use of lectins as markers for differentiated secretory cells in planarians.

PubMed

Zayas, Ricardo M; Cebrià, Francesc; Guo, Tingxia; Feng, Junjie; Newmark, Phillip A

2010-11-01

Freshwater planarians have reemerged as excellent models to investigate mechanisms underlying regeneration. The introduction of molecular tools has facilitated the study of planarians, but cell- and tissue-specific markers are still needed to examine differentiation of most cell types. Here we report the utility of fluorescent lectin-conjugates to label tissues in the planarian Schmidtea mediterranea. We show that 16 lectin-conjugates stain planarian cells or tissues; 13 primarily label the secretory cells, their cytoplasmic projections, and terminal pores. Thus, we examined regeneration of the secretory system using lectin markers and functionally characterized two genes expressed in the secretory cells: marginal adhesive gland-1 (mag-1) and Smed-reticulocalbin1 (Smed-rcn1). RNAi knockdown of these genes caused a dramatic reduction of secretory cell lectin staining, suggesting a role for mag-1 and Smed-rcn1 in secretory cell differentiation. Our results provide new insights into planarian secretory system regeneration and add new markers for labeling several planarian tissues. © 2010 Wiley-Liss, Inc.

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

Structural analysis, molecular docking and molecular dynamics of an edematogenic lectin from Centrolobium microchaete seeds.

PubMed

Neco, Antonio Hadson Bastos; Pinto-Junior, Vanir Reis; Araripe, David Alencar; Santiago, Mayara Queiroz; Osterne, Vinicius Jose Silva; Lossio, Claudia Figueiredo; Nobre, Clareane Avelino Simplicio; Oliveira, Messias Vital; Silva, Mayara Torquato Lima; Martins, Maria Gleiciane Queiroz; Cajazeiras, Joao Batista; Marques, Gabriela Fernandes Oliveira; Costa, Diego Rabelo; Nascimento, Kyria Santiago; Assreuy, Ana Maria Sampaio; Cavada, Benildo Sousa

2018-05-24

Lectins represent a class of proteins or glycoproteins capable of reversibly binding to carbohydrates. Seed lectins from the Dalbergieae tribe (Leguminosae) have structural variability, carbohydrate specificity, and biological effects, such as inflammation, vasorelaxation and cancer antigen binding. To comprehensively address these factors, the present work aimed to establish and characterize the three-dimensional structure of Centrolobium microchaete lectin (CML) by homology modeling, investigate protein-carbohydrate interactions and evaluate its inflammatory effect on mice. Molecular docking was performed to analyze interactions of the lectin with monosaccharides, disaccharides and N-glycans. Two dimannosides, methyl mannose-1,3-α-D-mannose (MDM) and mannose-1,3-α-D-mannose (M13), were used in molecular dynamics (MD) simulations to study the behavior of the carbohydrate-recognition domain (CRD) over time. Results showed an expanded domain within which hydrophobic interactions with the methyl group in the MDM molecule were established, thus revealing novel interactions for mannose-specific Dalbergieae lectins. To examine its biological activities, CML was purified in a single step by affinity chromatography on Sepharose-mannose matrix. The lectin demonstrated inflammatory response in the paw edema model and stimulated leukocyte migration to the animal peritoneal cavities, an effect elicited by CRD. For the first time, this work reports the molecular dynamics of a lectin from the Dalbergieae tribe. Copyright © 2018 Elsevier B.V. All rights reserved.

Predictive value of the complement system for sepsis-induced disseminated intravascular coagulation in septic patients in emergency department.

PubMed

Zhao, Xin; Chen, Yun-Xia; Li, Chun-Sheng

2015-04-01

To investigate changes in circulating complement component C3, membrane attack complex (MAC), and mannose-binding lectin (MBL) in patients with sepsis-induced disseminated intravascular coagulation (DIC). Adult septic patients admitted to the emergency department (ED) of Beijing Chao-Yang Hospital were enrolled. A DIC score of 5 or higher was considered sepsis-induced DIC. Circulating C3, MAC, and MBL levels were detected on ED arrival and compared between patients with and without DIC. The predictive value of C3, MAC, and MBL for sepsis-induced DIC at ED arrival and development of DIC after admission were assessed by receiver operating characteristic curve and logistic regression. We enrolled 267 septic patients between February and December 2013. Complement 3, MAC, and MBL were higher in the DIC group (P < .01). Membrane attack complex was the independent predictor of sepsis-induced DIC. The area under the curve of MAC in predicting sepsis-induced DIC was 0.793. During hospitalization, 25 patients without DIC at enrollment developed DIC. Membrane attack complex and Sequential Organ Failure Assessment independently predicted progress to DIC. The area under the curve of MAC was 0.741. Complement 3, MAC, and MBL were significantly increased in septic patients with DIC. Membrane attack complex independently predicted sepsis-induced DIC and development of DIC after ED admission. Copyright © 2014 Elsevier Inc. All rights reserved.

Identification of cell surface glycoprotein markers for glioblastoma-derived stem-like cells using a lectin microarray and LC-MS/MS approach

PubMed Central