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Sample records for receptor c-type lectin

  1. Inhibitory C-type lectin receptors in myeloid cells

    PubMed Central

    Redelinghuys, Pierre; Brown, Gordon D.

    2011-01-01

    C-type lectin receptors encoded by the natural killer gene complex play critical roles in enabling NK cell discrimination between self and non-self. In recent years, additional genes at this locus have been identified with patterns of expression that extend to cells of the myeloid lineage where many of the encoded inhibitory receptors have equally important functions as regulators of immune homeostasis. In the present review we highlight the roles of some of these receptors including recent insights gained with regard to the identification of exogenous and endogenous ligands, mechanisms of cellular inhibition and activation, regulated expression within different cellular and immune contexts, as well as functions that include the regulation of bone homeostasis and involvement in autoimmunity. PMID:20934454

  2. Targeting C-Type Lectin Receptors for Cancer Immunity

    PubMed Central

    Yan, Huimin; Kamiya, Tomomori; Suabjakyong, Papawee; Tsuji, Noriko M.

    2015-01-01

    C-type lectin receptors (CLRs) are a large family of soluble and trans-membrane pattern recognition receptors that are widely and primarily expressed on myeloid cells. CLRs are important for cell–cell communication and host defense against pathogens through the recognition of specific carbohydrate structures. Similar to a family of Toll-like receptors, CLRs signaling are involved in the various steps for initiation of innate immune responses and promote secretion of soluble factors such as cytokines and interferons. Moreover, CLRs contribute to endocytosis and antigen presentation, thereby fine-tune adaptive immune responses. In addition, there may also be a direct activation of acquired immunity. On the other hand, glycans, such as mannose structures, Lewis-type antigens, or GalNAc are components of tumor antigens and ligate CLRs, leading to immunoregulation. Therefore, agonists or antagonists of CLRs signaling are potential therapeutic reagents for cancer immunotherapy. We aim to overview the current knowledge of CLRs signaling and the application of their ligands on tumor-associating immune response. PMID:26379663

  3. C-type Lectin Receptors for Tumor Eradication: Future Directions

    PubMed Central

    Streng-Ouwehand, Ingeborg; Unger, Wendy W. J.; van Kooyk, Yvette

    2011-01-01

    Dendritic cells are key regulators in directing immune responses and therefore are under extensive research for the induction of anti-tumor responses. DCs express a large array of receptors by which they scan their surroundings for recognition and uptake of pathogens. One of the receptor-families is the C-type lectins (CLR), which bind carbohydrate structures and internalize antigens upon recognition. Intracellular routing of antigen through CLR enhances loading and presentation of antigen through MHC class I and II, inducing antigen-specific CD4+ and CD8+ T-cell proliferation and skewing T-helper cells. These characteristics make CLRs very interesting targets for DC-based immunotherapy. Profound research has been done on targeting specific tumor antigens to CLR using either antibodies or the natural ligands such as glycan structures. In this review we will focus on the current data showing the potency of CLR-targeting and discuss improvements that can be achieved to enhance anti-tumor activity in the near future. PMID:24212951

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

    SciTech Connect

    Matsuno, Keita; Nakayama, Eri; Noyori, Osamu; Marzi, Andrea; Ebihara, Hideki; Irimura, Tatsuro; Feldmann, Heinz; Takada, Ayato

    2010-12-03

    Research highlights: {yields} Filovirus glycoprotein (GP) having a deficient receptor binding region were generated. {yields} Mutant GPs mediated virus entry less efficiently than wild-type GP. {yields} Mutant GPs bound to C-type lectins but not mediated entire steps of cellular entry. {yields} C-type lectins do not independently mediate filovirus entry into cells. {yields} Other molecule(s) are required for C-type lectin-mediated entry of filoviruses. -- Abstract: Cellular C-type lectins have been reported to facilitate filovirus infection by binding to glycans on filovirus glycoprotein (GP). However, it is not clearly known whether interaction between C-type lectins and GP mediates all the steps of virus entry (i.e., attachment, internalization, and membrane fusion). In this study, we generated vesicular stomatitis viruses pseudotyped with mutant GPs that have impaired structures of the putative receptor binding regions and thus reduced ability to infect the monkey kidney cells that are routinely used for virus propagation. We found that infectivities of viruses with the mutant GPs dropped in C-type lectin-expressing cells, parallel with those in the monkey kidney cells, whereas binding activities of these GPs to the C-type lectins were not correlated with the reduced infectivities. These results suggest that C-type lectin-mediated entry of filoviruses requires other cellular molecule(s) that may be involved in virion internalization or membrane fusion.

  5. Sensing of cell death by myeloid C-type lectin receptors

    PubMed Central

    Sancho, David; Reis e Sousa, Caetano

    2015-01-01

    Molecules associated with dead or dying cells can be detected by receptors on macrophages and dendritic cells. Signals from these receptors impact myeloid cell function and play a role in determining whether death is silent or proinflammatory, tolerogenic or immunogenic. Prominent among myeloid receptors detecting dead cells are C-type lectin receptors (CLRs). Signals from these receptors variably induce endocytosis of cell corpses, corpse degradation, retrieval of dead cell-associated antigens and/or modulation of immune responses. The sensing of tissue damage by myeloid CLRs complements detection of pathogens in immunity and represents an ancient response aimed at restoring tissue homeostasis. PMID:23332826

  6. Genes encoding putative natural killer cell C-type lectin receptors in teleostean fishes

    PubMed Central

    Sato, Akie; Mayer, Werner E.; Overath, Peter; Klein, Jan

    2003-01-01

    Mammalian natural killer (NK) cells are cytotoxic lymphocytes that express receptors specific for MHC class I molecules. The NK cell receptors belong to two structurally unrelated families, the killer cell Ig-like receptors and the killer cell C-type lectin receptors. We describe a cDNA clone derived from the bony (cichlid) fish Paralabidochromis chilotes and show that it encodes a protein related to the CD94/NK cell group 2 (NKG2) subfamily of the killer cell C-type lectin receptors. The gene encoding this receptor in a related species, Oreochromis niloticus, has a similar structure to the human CD94/NKG2 genes and is a member of a multigene cluster that resembles the mammalian NK cell gene complex. Thus, the CD94/NKG2 subfamily of NK cell receptors must have arisen before the divergence of fish and tetrapods and may have retained its function (possibly monitoring the expression of MHC class I molecules) for >400 million years. PMID:12802013

  7. MCL and Mincle: C-Type Lectin Receptors That Sense Damaged Self and Pathogen-Associated Molecular Patterns

    PubMed Central

    Richardson, Mark B.; Williams, Spencer J.

    2014-01-01

    Macrophage C-type lectin (MCL) and macrophage inducible C-type lectin (Mincle) comprise part of an extensive repertoire of pattern recognition receptors with the ability to sense damage-associated and pathogen-associated molecular patterns. In this review, we cover the discovery and molecular characterization of these C-type lectin receptors, and highlight recent advances in the understanding of their roles in orchestrating the response of the immune system to bacterial and fungal infection, and damaged self. We also discuss the identification and structure–activity relationships of activating ligands, particularly trehalose dimycolate and related mycobacterial glycolipids, which have significant potential in the development of TH1/TH17 vaccination strategies. PMID:25002863

  8. Signalling versatility following self and non-self sensing by myeloid C-type lectin receptors

    PubMed Central

    Iborra, Salvador; Sancho, David

    2015-01-01

    Among myeloid immune receptors, C-type lectin receptors (CLRs) have a remarkable capacity to sense a variety of self and non-self ligands. The coupling of CLRs to different signal transduction modules is influenced not only by the receptor, but also by the nature, density and architecture of the ligand, which can affect the rate of receptor internalization and trafficking to diverse intracellular compartments. Understanding how the variety of self and non-self ligands triggers differential CLR signalling and function presents a fascinating biological challenge. Non-self ligands usually promote inflammation and immunity, whereas self ligands are frequently involved in communication and tolerance. But pathogens can mimic self-inhibitory signals to escape immune surveillance, and endogenous ligands can contribute to the sensing of pathogens through CLRs. In this review, we survey the complexity and flexibility in functional outcome found in the myeloid CLRs, which is not only based on their differing intracellular motifs, but is also conditioned by the physical nature, affinity and avidity of the ligand. PMID:25269828

  9. Computational and Experimental Prediction of Human C-Type Lectin Receptor Druggability

    PubMed Central

    Aretz, Jonas; Wamhoff, Eike-Christian; Hanske, Jonas; Heymann, Dario; Rademacher, Christoph

    2014-01-01

    Mammalian C-type lectin receptors (CTLRS) are involved in many aspects of immune cell regulation such as pathogen recognition, clearance of apoptotic bodies, and lymphocyte homing. Despite a great interest in modulating CTLR recognition of carbohydrates, the number of specific molecular probes is limited. To this end, we predicted the druggability of a panel of 22 CTLRs using DoGSiteScorer. The computed druggability scores of most structures were low, characterizing this family as either challenging or even undruggable. To further explore these findings, we employed a fluorine-based nuclear magnetic resonance screening of fragment mixtures against DC-SIGN, a receptor of pharmacological interest. To our surprise, we found many fragment hits associated with the carbohydrate recognition site (hit rate = 13.5%). A surface plasmon resonance-based follow-up assay confirmed 18 of these fragments (47%) and equilibrium dissociation constants were determined. Encouraged by these findings we expanded our experimental druggability prediction to Langerin and MCL and found medium to high hit rates as well, being 15.7 and 10.0%, respectively. Our results highlight limitations of current in silico approaches to druggability assessment, in particular, with regard to carbohydrate-binding proteins. In sum, our data indicate that small molecule ligands for a larger panel of CTLRs can be developed. PMID:25071783

  10. The evolution of HIV-1 interactions with coreceptors and mannose C-type lectin receptors.

    PubMed

    Borggren, Marie; Jansson, Marianne

    2015-01-01

    The phenotype of human immunodeficiency virus type 1 (HIV-1) commonly evolves between and within infected individuals, at virus transmission, and during disease progression. This evolution includes altered interactions between the virus and its coreceptors, i.e., chemokine receptors, as well as mannose C-type lectin receptors (CLRs). Transmitted/founder viruses are predominantly restricted to CCR5, whereas the subsequent intrapatient evolution of HIV-1 coreceptor use during progressive disease can be subdivided into two distinct pathways. Accordingly, the CCR5-restricted virus population is either gradually replaced by virus variants able to use CXCR4 or evolves toward an altered, more flexible use of CCR5. Despite a strong dependency on these coreceptors for host cell entry, HIV-1 also interacts with other cell surface molecules during target cell attachment, including the CLRs. The virus interaction with the CLRs may result either in the efficient transfer of virus to CD4(+) T cells or in the degradation of the virus in endosomal compartments. The determinants of the diverse outcomes depend on which CLR is engaged and also on the glycan makeup of the envelope glycoproteins, which may evolve with the strength of the immune pressure during the disease course. With the current clinical introduction of CCR5 antagonists and the development of additional entry inhibitors, knowledge on the evolution and baseline characteristics of HIV-1 interactions with coreceptor and CLR interactions may play important roles for individualized and optimized treatment strategies. This review summarizes our current understanding of the evolution of HIV-1 interactions with these receptors. PMID:25595802

  11. C-type Lectin Receptor Expression on Human Basophils and Effects of Allergen-Specific Immunotherapy.

    PubMed

    Lundberg, K; Rydnert, F; Broos, S; Andersson, M; Greiff, L; Lindstedt, M

    2016-09-01

    Basophils are emerging as immunoregulatory cells capable of interacting with their environment not only via their characteristic IgE-mediated activation, but also in an IgE-independent manner. Basophils are known to express and respond to stimulation via TLR2, TLR4, DC-SIGN and DCIR, but whether basophils also express other C-type lectin receptors (CLRs) is largely unknown. In this study, we investigate the CLR expression profile of human basophils using multicolour flow cytometry. As FcRs as well as some CLRs are associated with allergen recognition and shown to be involved in subsequent immune responses, the expression of CLRs and FcRs on peripheral blood basophils, as well as their frequency, was monitored for 1 year in subjects undergoing subcutaneous allergen-specific immunotherapy (AIT). Here, we show that human basophils express CLECSF14, DEC205, Dectin-1, Dectin-2 and MRC2. Furthermore, we demonstrate that the frequencies of basophils expressing the allergy-associated CLRs Dectin-1 and Dectin-2 were significantly reduced after 1 year and 8 weeks of AIT, respectively. In contrast, the frequency of basophils positive for FcγRII, as well as the fraction of total basophils, significantly increased after 1 year of AIT. The herein demonstrated expression of various CLRs on basophils, and their altered CLR and FcR expression profile upon AIT, suggest yet unexplored ways by which basophils can interact with antigens and may point to novel immunoregulatory functions targeted through AIT. PMID:27354239

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

    PubMed Central

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

    2015-01-01

    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). Ca2+ 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 Ca2+-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. PMID:26690423

  13. Toll-Like Receptors and Dectin-1, a C-Type Lectin Receptor, Trigger Divergent Functions in CNS Macrophages

    PubMed Central

    Wang, Yan; Guan, Zhen; Beckwith, Kyle A.; Braun, Kaitlyn J.; Wei, Ping; McTigue, Dana M.

    2015-01-01

    Spinal cord injury (SCI) activates macrophages, endowing them with both reparative and pathological functions. The mechanisms responsible for these divergent functions are unknown but are likely controlled through stochastic activation of different macrophage receptor subtypes. Various danger-associated molecular patterns released from dying cells in the injured spinal cord likely activate distinct subtypes of macrophage pattern recognition receptors, including bacterial toll-like receptors (TLRs) and fungal C-type lectin receptors (e.g., dectin-1). To determine the in vivo consequences of activating these receptors, ligands specific for TLR2 or dectin-1 were microinjected, alone or in combination, into intact spinal cord. Both ligands elicit a florid macrophage reaction; however, only dectin-1 activation causes macrophage-mediated demyelination and axonal injury. Coactivating TLR2 reduced the injurious effects of dectin-1 activation. When injected into traumatically injured spinal cord, TLR2 agonists enhance the endogenous macrophage reaction while conferring neuroprotection. Indeed, dieback of axons was reduced, leading to smaller lesion volumes at the peak of the macrophage response. Moreover, the density of NG2+ cells expressing vimentin increased in and near lesions that were enriched with TLR2-activated macrophages. In dectin-1-null mutant (knock-out) mice, dieback of corticospinal tract axons also is reduced after SCI. Collectively, these data support the hypothesis that the ability of macrophages to create an axon growth-permissive microenvironment or cause neurotoxicity is receptor dependent and it may be possible to exploit this functional dichotomy to enhance CNS repair. SIGNIFICANCE STATEMENT There is a growing appreciation that macrophages exert diverse functions in the injured and diseased CNS. Indeed, both macrophage-mediated repair and macrophage-mediated injury occur, and often these effector functions are elicited simultaneously. Understanding the

  14. C-type lectin receptors differentially induce th17 cells and vaccine immunity to the endemic mycosis of North America.

    PubMed

    Wang, Huafeng; LeBert, Vanessa; Hung, Chiung Yu; Galles, Kevin; Saijo, Shinobu; Lin, Xin; Cole, Garry T; Klein, Bruce S; Wüthrich, Marcel

    2014-02-01

    Vaccine immunity to the endemic mycoses of North America requires Th17 cells, but the pattern recognition receptors and signaling pathways that drive these protective responses have not been defined. We show that C-type lectin receptors exert divergent contributions to the development of antifungal Th17 cells and vaccine resistance against Blastomyces dermatitidis, Histoplasma capsulatum, and Coccidioides posadasii. Acquired immunity to B. dermatitidis requires Dectin-2, whereas vaccination against H. capsulatum and C. posadasii infection depends on innate sensing by Dectin-1 and Dectin-2, but not Mincle. Tracking Ag-specific T cells in vivo established that the Card9 signaling pathway acts indispensably and exclusively on differentiation of Th17 cells, while leaving intact their activation, proliferation, survival, and migration. Whereas Card9 signaling is essential, C-type lectin receptors offer distinct and divergent contributions to vaccine immunity against these endemic fungal pathogens. Our work provides new insight into innate immune mechanisms that drive vaccine immunity and Th17 cells. PMID:24391211

  15. Abundant Expression of HIV Target Cells and C-Type Lectin Receptors in the Foreskin Tissue of Young Kenyan Men

    PubMed Central

    Hirbod, Taha; Bailey, Robert C.; Agot, Kawango; Moses, Stephen; Ndinya-Achola, Jeckoniah; Murugu, Ruth; Andersson, Jan; Nilsson, Jakob; Broliden, Kristina

    2010-01-01

    A biological explanation for the reduction in HIV-1 (HIV) acquisition after male circumcision may be that removal of the foreskin reduces the number of target cells for HIV. The expression of potential HIV target cells and C-type lectin receptors in foreskin tissue of men at risk of HIV infection were thus analyzed. Thirty-three foreskin tissue samples, stratified by Herpes simplex virus type 2 status, were obtained from a randomized, controlled trial conducted in Kenya. The samples were analyzed by confocal in situ imaging microscopy and mRNA quantification by quantitative RT-qPCR. The presence and location of T cells (CD3+CD4+), Langerhans cells (CD1a+Langerin/CD207+), macrophages (CD68+ or CD14+), and submucosal dendritic cells (CD123+BDCA-2+ or CD11c+DC-SIGN+) were defined. C-type lectin receptor expressing cells were detected in both the epithelium and submucosa, and distinct lymphoid aggregates densely populated with CD3+CD4+ T cells were identified in the submucosa. Although the presence of lymphoid aggregates and mRNA expression of selected markers varied between study subjects, Herpes simplex virus type 2 serostatus was not the major determinant for the detected differences. The detection of abundant and superficially present potential HIV target cells and submucosal lymphoid aggregates in foreskin mucosa from a highly relevant HIV risk group demonstrate a possible anatomical explanation that may contribute to the protective effect of male circumcision on HIV transmission. PMID:20395432

  16. Scavenger Receptor C-Type Lectin Binds to the Leukocyte Cell Surface Glycan Lewis By a Novel Mechanism

    SciTech Connect

    Feinberg, H.; Taylor, M.E.; Weis, W.I.; /Stanford U., Med. School /Imperial Coll., London

    2007-07-10

    The scavenger receptor C-type lectin (SRCL) is unique in the family of class A scavenger receptors, because in addition to binding sites for oxidized lipoproteins it also contains a C-type carbohydrate-recognition domain (CRD) that interacts with specific glycans. Both human and mouse SRCL are highly specific for the Lewis(x) trisaccharide, which is commonly found on the surfaces of leukocytes and some tumor cells. Structural analysis of the CRD of mouse SRCL in complex with Lewis(x) and mutagenesis show the basis for this specificity. The interaction between mouse SRCL and Lewis(x) is analogous to the way that selectins and DC-SIGN bind to related fucosylated glycans, but the mechanism of the interaction is novel, because it is based on a primary galactose-binding site similar to the binding site in the asialoglycoprotein receptor. Crystals of the human receptor lacking bound calcium ions reveal an alternative conformation in which a glycan ligand would be released during receptor-mediated endocytosis.

  17. Lectin-dependent enhancement of Ebola virus infection via soluble and transmembrane C-type lectin receptors.

    PubMed

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

    2013-01-01

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

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

    PubMed Central

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

    2013-01-01

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

  19. SHP-2 Mediates C-type Lectin Receptors-induced Syk Activation and Anti-fungal TH17 Responses

    PubMed Central

    Deng, Zihou; Ma, Shixin; Zhou, Hao; Zang, Aiping; Fang, Yiyuan; Li, Tiantian; Shi, Huanjing; Liu, Mei; Du, Min; Taylor, Patricia R.; Zhu, Helen H.; Chen, Jiangye; Meng, Guangxun; Li, Fubin; Chen, Changbin; Zhang, Yan; Jia, Xin-Ming; Lin, Xin; Zhang, Xiaoming; Pearlman, Eric; Li, Xiaoxia; Feng, Gen-Sheng; Xiao, Hui

    2015-01-01

    SUMMARY Fungal infection stimulates the canonical C-type lectin receptors (CLRs) signaling pathway via Syk activation. Here we show that SHP-2 plays a crucial role in mediating CLRs-induced Syk activation. Genetic ablation of Shp-2 (Ptpn11) in dendritic cells (DCs) and macrophages impaired Syk-mediated signaling and abrogated pro-inflammatory gene expression following fungal stimulation. Mechanistically, SHP-2 operates as a scaffold facilitating the recruitment of Syk to dectin-1 or FcRγ, through its N-SH2 domain and a previously unrecognized C-terminal ITAM motif. We demonstrate that DC-derived SHP-2 is crucial for the induction of IL-1β, IL-6 and IL-23, and anti-fungal TH17 cell responses to control Candida albicans infection. Together, these data reveal a mechanism by which SHP-2 mediates Syk activation in response to fungal infections PMID:25915733

  20. 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

  1. Mechanistic Insights into the Role of C-Type Lectin Receptor/CARD9 Signaling in Human Antifungal Immunity

    PubMed Central

    Drummond, Rebecca A.; Lionakis, Michail S.

    2016-01-01

    Human CARD9 deficiency is an autosomal recessive primary immunodeficiency disorder caused by biallelic mutations in the gene CARD9, which encodes a signaling protein that is found downstream of many C-type lectin receptors (CLRs). CLRs encompass a large family of innate recognition receptors, expressed predominantly by myeloid and epithelial cells, which bind fungal carbohydrates and initiate antifungal immune responses. Accordingly, human CARD9 deficiency is associated with the spontaneous development of persistent and severe fungal infections that primarily localize to the skin and subcutaneous tissue, mucosal surfaces and/or central nervous system (CNS). In the last 3 years, more than 15 missense and nonsense CARD9 mutations have been reported which associate with the development of a wide spectrum of fungal infections caused by a variety of fungal organisms. The mechanisms by which CARD9 provides organ-specific protection against these fungal infections are now emerging. In this review, we summarize recent immunological and clinical advances that have provided significant mechanistic insights into the pathogenesis of human CARD9 deficiency. We also discuss how genetic mutations in CARD9-coupled receptors (Dectin-1, Dectin-2) and CARD9-binding partners (MALT1, BCL10) affect human antifungal immunity relative to CARD9 deficiency, and we highlight major understudied research questions which merit future investigation. PMID:27092298

  2. Mechanistic Insights into the Role of C-Type Lectin Receptor/CARD9 Signaling in Human Antifungal Immunity.

    PubMed

    Drummond, Rebecca A; Lionakis, Michail S

    2016-01-01

    Human CARD9 deficiency is an autosomal recessive primary immunodeficiency disorder caused by biallelic mutations in the gene CARD9, which encodes a signaling protein that is found downstream of many C-type lectin receptors (CLRs). CLRs encompass a large family of innate recognition receptors, expressed predominantly by myeloid and epithelial cells, which bind fungal carbohydrates and initiate antifungal immune responses. Accordingly, human CARD9 deficiency is associated with the spontaneous development of persistent and severe fungal infections that primarily localize to the skin and subcutaneous tissue, mucosal surfaces and/or central nervous system (CNS). In the last 3 years, more than 15 missense and nonsense CARD9 mutations have been reported which associate with the development of a wide spectrum of fungal infections caused by a variety of fungal organisms. The mechanisms by which CARD9 provides organ-specific protection against these fungal infections are now emerging. In this review, we summarize recent immunological and clinical advances that have provided significant mechanistic insights into the pathogenesis of human CARD9 deficiency. We also discuss how genetic mutations in CARD9-coupled receptors (Dectin-1, Dectin-2) and CARD9-binding partners (MALT1, BCL10) affect human antifungal immunity relative to CARD9 deficiency, and we highlight major understudied research questions which merit future investigation. PMID:27092298

  3. The C-Type Lectin Receptor CLECSF8/CLEC4D Is a Key Component of Anti-Mycobacterial Immunity

    PubMed Central

    Wilson, Gillian J.; Marakalala, Mohlopheni J.; Hoving, Jennifer C.; van Laarhoven, Arjan; Drummond, Rebecca A.; Kerscher, Bernhard; Keeton, Roanne; van de Vosse, Esther; Ottenhoff, Tom H.M.; Plantinga, Theo S.; Alisjahbana, Bachti; Govender, Dhirendra; Besra, Gurdyal S.; Netea, Mihai G.; Reid, Delyth M.; Willment, Janet A.; Jacobs, Muazzam; Yamasaki, Sho; van Crevel, Reinout; Brown, Gordon D.

    2015-01-01

    Summary The interaction of microbes with pattern recognition receptors (PRRs) is essential for protective immunity. While many PRRs that recognize mycobacteria have been identified, none is essentially required for host defense in vivo. Here, we have identified the C-type lectin receptor CLECSF8 (CLEC4D, MCL) as a key molecule in anti-mycobacterial host defense. Clecsf8−/− mice exhibit higher bacterial burdens and increased mortality upon M. tuberculosis infection. Additionally, Clecsf8 deficiency is associated with exacerbated pulmonary inflammation, characterized by enhanced neutrophil recruitment. Clecsf8−/− mice show reduced mycobacterial uptake by pulmonary leukocytes, but infection with opsonized bacteria can restore this phagocytic defect as well as decrease bacterial burdens. Notably, a CLECSF8 polymorphism identified in humans is associated with an increased susceptibility to pulmonary tuberculosis. We conclude that CLECSF8 plays a non-redundant role in anti-mycobacterial immunity in mouse and in man. PMID:25674984

  4. The C-Type Lectin Receptor MCL Mediates Vaccine-Induced Immunity against Infection with Blastomyces dermatitidis.

    PubMed

    Wang, Huafeng; Li, Mengyi; Lerksuthirat, Tassanee; Klein, Bruce; Wüthrich, Marcel

    2015-01-01

    C-type lectin receptors (CLRs) are essential in shaping the immune response to fungal pathogens. Vaccine-induced resistance requires Dectin-2 to promote differentiation of antifungal Th1 and Th17 cells. Since Dectin-2 and MCL heterodimerize and both CLRs use FcRγ as the signaling adaptor, we investigated the role of MCL in vaccine immunity to the fungal pathogen Blastomyces dermatitidis. MCL(-/-) mice showed impaired vaccine resistance against B. dermatitidis infection compared to that of wild-type animals. The lack of resistance correlated with the reduced recruitment of Th17 cells to the lung upon recall following experimental challenge and impaired interleukin-17 (IL-17) production by vaccine antigen-stimulated splenocytes in vitro. Soluble MCL fusion protein recognized and bound a water-soluble ligand from the cell wall of vaccine yeast, but the addition of soluble Dectin-2 fusion protein did not augment ligand recognition by MCL. Taken together, our data indicate that MCL regulates the development of vaccine-induced Th17 cells and protective immunity against lethal experimental infection with B. dermatitidis. PMID:26667836

  5. C-type lectins, fungi and Th17 responses

    PubMed Central

    Vautier, Simon; Sousa, Maria da Glória; Brown, Gordon D.

    2010-01-01

    Th17 cells are a recently discovered subset of T helper cells characterised by the release of IL-17, and are thought to be important for mobilization of immune responses against microbial pathogens, but which also contribute to the development of autoimmune diseases. The identification of C-type lectin receptors which are capable of regulating the balance between Th1 and Th17 responses has been of particular recent interest, which they control, in part, though the release of Th17 inducing cytokines. Many of these receptors recognise fungi, and other pathogens, and play key roles in driving the development of protective anti-microbial immunity. Here we will review the C-type lectins that have been linked to Th17 type responses and will briefly examine the role of Th17 responses in murine and human anti-fungal immunity. PMID:21075040

  6. C-type lectin-like receptor LOX-1 promotes dendritic cell-mediated class-switched B cell responses.

    PubMed

    Joo, HyeMee; Li, Dapeng; Dullaers, Melissa; Kim, Tae-Whan; Duluc, Dorothee; Upchurch, Katherine; Xue, Yaming; Zurawski, Sandy; Le Grand, Roger; Liu, Yong-Jun; Kuroda, Marcelo; Zurawski, Gerard; Oh, SangKon

    2014-10-16

    Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is a pattern-recognition receptor for a variety of endogenous and exogenous ligands. However, LOX-1 function in the host immune response is not fully understood. Here, we report that LOX-1 expressed on dendritic cells (DCs) and B cells promotes humoral responses. On B cells LOX-1 signaling upregulated CCR7, promoting cellular migration toward lymphoid tissues. LOX-1 signaling on DCs licensed the cells to promote B cell differentiation into class-switched plasmablasts and led to downregulation of chemokine receptor CXCR5 and upregulation of chemokine receptor CCR10 on plasmablasts, enabling their exit from germinal centers and migration toward local mucosa and skin. Finally, we found that targeting influenza hemagglutinin 1 (HA1) subunit to LOX-1 elicited HA1-specific protective antibody responses in rhesus macaques. Thus, LOX-1 expressed on B cells and DC cells has complementary functions to promote humoral immune responses. PMID:25308333

  7. 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. PMID:27443248

  8. Characterization of the Expression and Function of the C-Type Lectin Receptor CD302 in Mice and Humans Reveals a Role in Dendritic Cell Migration.

    PubMed

    Lo, Tsun-Ho; Silveira, Pablo A; Fromm, Phillip D; Verma, Nirupama D; Vu, Phi A; Kupresanin, Fiona; Adam, Rhonda; Kato, Masato; Cogger, Victoria C; Clark, Georgina J; Hart, Derek N J

    2016-08-01

    C-type lectin receptors play important roles in immune cell interactions with the environment. We described CD302 as the simplest, single domain, type I C-type lectin receptor and showed it was expressed mainly on the myeloid phagocytes in human blood. CD302 colocalized with podosomes and lamellopodia structures, so we hypothesized that it played a role in cell adhesion or migration. In this study, we used mouse models to obtain further insights into CD302 expression and its potential immunological function. Mouse CD302 transcripts were, as in humans, highest in the liver, followed by lungs, lymph nodes (LN), spleen, and bone marrow. In liver, CD302 was expressed by hepatocytes, liver sinusoidal endothelial cells, and Kupffer cells. A detailed analysis of CD302 transcription in mouse immune cells revealed highest expression by myeloid cells, particularly macrophages, granulocytes, and myeloid dendritic cells (mDC). Interestingly, 2.5-fold more CD302 was found in migratory compared with resident mDC populations and higher CD302 expression in mouse M1 versus M2 macrophages was also noteworthy. CD302 knockout (CD302KO) mice were generated. Studies on the relevant immune cell populations revealed a decrease in the frequency and numbers of migratory mDC within CD302KO LN compared with wild-type LN. In vitro studies showed CD302KO and wild-type DC had an equivalent capacity to undergo maturation, prime T cells, uptake Ags, and migrate toward the CCL19/CCL21 chemokines. Nevertheless, CD302KO migratory DC exhibited reduced in vivo migration into LN, confirming a functional role for CD302 in mDC migration. PMID:27316686

  9. Molecular characterization of a transmembrane C-type lectin receptor gene from ayu (Plecoglossus altivelis) and its effect on the recognition of different bacteria by monocytes/macrophages.

    PubMed

    Zhang, Xue-Heng; Shi, Yu-Hong; Chen, Jiong

    2015-08-01

    C-type lectin receptors (CTLRs) play vital roles in immune responses as pattern-recognition receptors (PRRs). In this study, we identified a novel C-type lectin receptor (PaCTLRC) gene from ayu, Plecoglossus altivelis. Predicted PaCTLRC is a single transmembrane receptor with a typical carbohydrate recognition domain (CRD) at its C-terminus. Sequence comparison and phylogenetic tree analysis showed that PaCTLRC was most closely related to Atlantic salmon (Salmo salar) CLRC, but was significantly different from two other ayu CTLRs, aCLR and PaCD209L. PaCTLRC transcript was detected in all tested tissues and cells, with high levels in the liver; and its expression was significantly altered upon Vibrio anguillarum infection. Refolded recombinant PaCTLRC (rPaCTLRC) agglutinated three types of Gram-positive bacteria (Listeria monocytogenes, Staphylococcus aureus and Streptococcus iniae) and four types of Gram-negative bacteria (Aeromonas hydrophila, Escherichia coli, V. anguillarum and Vibrio parahaemolyticus) in a Ca(2+)-dependent manner in vitro, and Gram-positive bacteria were shown to be biologically relevant ligands for PaCTLRC. rPaCTLRC bound to d-mannose, d-galactose, l-fucose, N-acetyl-d-glucosamine (GlcNAc), lipopolysaccharide (LPS) and peptidoglycan (PGN), exhibiting a relative binding strength to d-mannose and PGN. d-Mannose, l-fucose, GlcNAc, LPS and PGN could inhibit the agglutinating activity of rPaCTLRC, while d-galactose did not functioned. PaCTLRC neutralization using anti-PaCTLRC IgG resulted in the inhibition of phagocytosis by ayu monocytes/macrophages (MO/MΦ) of S. aureus but not of E. coli, and produced a consistently higher survival rate of S. aureus than that of E. coli. d-Mannose, LPS and PGN treatment had no significant influence on the phagocytosis of ayu MO/MΦ. These results suggest that PaCTLRC may serve as a Gram-positive bacteria-preferred PRR which is involved in pathogen recognition and signal transduction in ayu MO/MΦ. PMID:26010409

  10. Binding of sucrose octasulphate to the C-type lectin-like domain of the recombinant natural killer cell receptor NKR-P1A observed by NMR spectroscopy.

    PubMed

    Kogelberg, Heide; Frenkiel, Thomas A; Birdsall, Berry; Chai, Wengang; Muskett, Frederick W

    2002-11-01

    NKR-P1A is a C-type lectin-like receptor on natural killer cells believed to be involved in the cytotoxicity of these cells. Ligands for this protein are not known. Here, we describe the binding of a fully sulphated disaccharide, sucrose octasulphate, by the recombinant C-type lectin-like domain of NKR-P1A. The binding was observed by NMR spectroscopy methods that have recently been described for the screening of compound libraries for bioaffinities, namely the 2D NOESY and saturation transfer difference NMR experiments. (1)H titration studies indicate that the binding is specific. These findings raise the possibility that NKR-P1A recognises sulphated natural ligands in common with certain other members of the C-type lectin family. PMID:12404632

  11. C-type lectin Langerin is a β-glucan receptor on human Langerhans cells that recognizes opportunistic and pathogenic fungi

    PubMed Central

    de Jong, Marein A.W.P.; Vriend, Lianne E.M.; Theelen, Bart; Taylor, Maureen E.; Fluitsma, Donna; Boekhout, Teun; Geijtenbeek, Teunis B.H.

    2010-01-01

    Langerhans cells (LCs) lining the stratified epithelia and mucosal tissues are the first antigen presenting cells to encounter invading pathogens, such as viruses, bacteria and fungi. Fungal infections form a health threat especially in immuno-compromised individuals. LCs express C-type lectin Langerin that has specificity for mannose, fucose and GlcNAc structures. Little is known about the role of human Langerin in fungal infections. Our data show that Langerin interacts with both mannan and β-glucan structures, common cell-wall carbohydrate structures of fungi. We have screened a large panel of fungi for recognition by human Langerin and, strikingly, we observed strong binding of Langerin to a variety of Candida and Saccharomyces species and Malassezia furfur, but very weak binding was observed to Cryptococcus gattii and Cryptococcus neoformans. Notably, Langerin is the primary fungal receptor on LCs, since the interaction of LCs with the different fungi was blocked by antibodies against Langerin. Langerin recognizes both mannose and β-glucans present on fungal cell walls and our data demonstrate that Langerin is the major fungal pathogen receptor on human LCs that recognizes pathogenic and commensal fungi. Together these data may provide more insight in the role of LCs in fungal infections. PMID:20097424

  12. Syk and Src Family Kinases Regulate C-type Lectin Receptor 2 (CLEC-2)-mediated Clustering of Podoplanin and Platelet Adhesion to Lymphatic Endothelial Cells*

    PubMed Central

    Pollitt, Alice Y.; Poulter, Natalie S.; Gitz, Eelo; Navarro-Nuñez, Leyre; Wang, Ying-Jie; Hughes, Craig E.; Thomas, Steven G.; Nieswandt, Bernhard; Douglas, Michael R.; Owen, Dylan M.; Jackson, David G.; Dustin, Michael L.; Watson, Steve P.

    2014-01-01

    The interaction of C-type lectin receptor 2 (CLEC-2) on platelets with Podoplanin on lymphatic endothelial cells initiates platelet signaling events that are necessary for prevention of blood-lymph mixing during development. In the present study, we show that CLEC-2 signaling via Src family and Syk tyrosine kinases promotes platelet adhesion to primary mouse lymphatic endothelial cells at low shear. Using supported lipid bilayers containing mobile Podoplanin, we further show that activation of Src and Syk in platelets promotes clustering of CLEC-2 and Podoplanin. Clusters of CLEC-2-bound Podoplanin migrate rapidly to the center of the platelet to form a single structure. Fluorescence lifetime imaging demonstrates that molecules within these clusters are within 10 nm of one another and that the clusters are disrupted by inhibition of Src and Syk family kinases. CLEC-2 clusters are also seen in platelets adhered to immobilized Podoplanin using direct stochastic optical reconstruction microscopy. These findings provide mechanistic insight by which CLEC-2 signaling promotes adhesion to Podoplanin and regulation of Podoplanin signaling, thereby contributing to lymphatic vasculature development. PMID:25368330

  13. A C-type lectin receptor pathway is responsible for the pathogenesis of acute cyclophosphamide-induced cystitis in mice.

    PubMed

    Dejima, Takashi; Shibata, Kensuke; Yamada, Hisakata; Takeuchi, Ario; Hara, Hiromitsu; Eto, Masatoshi; Naito, Seiji; Yoshikai, Yasunobu

    2013-12-01

    Hemorrhagic cystitis often arises after cyclophosphamide (CYP) administration. As yet, however, the mechanism involved in its pathogenesis is unknown. In this study, it was found that the Fc receptor γ chain (FcRγ)- caspase recruitment domain-containing protein 9 (CARD9)-dependent pathway rather than the myeloid differentiation primary response gene 88 (MyD88)-dependent pathway is involved in the pathogenesis of acute CYP-induced cystitis in mice. Rapid and transient production of interleukin (IL)-6 and IL-1β was detected in the bladder at 4 hr, preceding IL-23 and IL-17A production and an influx of neutrophils, which reached a peak at 24 hr after injection. As assessed by weight, edema and neutrophil infiltration, cystitis was significantly attenuated in CARD9 knockout (KO) and FcRγKO mice, this attenuation being accompanied by impaired production of IL-1β, IL-6, IL-23 and IL-17A. The major source of IL-17A is the vesical γδ T cell population: IL-17AKO, CδKO and Tyk2KO mice showed little IL-17A production and reduced neutrophil infiltration in the bladder after CYP injection. These results suggest that FcRγ-CARD9-dependent production of proinflammatory cytokines such as IL-1β, IL-6, and IL-23 and the subsequent activation of IL-17A-producing γδ T cells are at least partly involved in the pathogenesis of acute CYP-induced cystitis in mice. PMID:24102807

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

    PubMed

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

    2007-10-01

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

  15. Critical Role for an Acidic Amino Acid Region in Platelet Signaling by the HemITAM (Hemi-immunoreceptor Tyrosine-based Activation Motif) Containing Receptor CLEC-2 (C-type Lectin Receptor-2)*

    PubMed Central

    Hughes, Craig E.; Sinha, Uma; Pandey, Anjali; Eble, Johannes A.; O'Callaghan, Christopher A.; Watson, Steve P.

    2013-01-01

    CLEC-2 is a member of new family of C-type lectin receptors characterized by a cytosolic YXXL downstream of three acidic amino acids in a sequence known as a hemITAM (hemi-immunoreceptor tyrosine-based activation motif). Dimerization of two phosphorylated CLEC-2 molecules leads to recruitment of the tyrosine kinase Syk via its tandem SH2 domains and initiation of a downstream signaling cascade. Using Syk-deficient and Zap-70-deficient cell lines we show that hemITAM signaling is restricted to Syk and that the upstream triacidic amino acid sequence is required for signaling. Using surface plasmon resonance and phosphorylation studies, we demonstrate that the triacidic amino acids are required for phosphorylation of the YXXL. These results further emphasize the distinct nature of the proximal events in signaling by hemITAM relative to ITAM receptors. PMID:23264619

  16. 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. PMID:24550728

  17. Enhancement of solubility and yield of a β-glucan receptor Dectin-1 C-type lectin-like domain in Escherichia coli with a solubility-enhancement tag.

    PubMed

    Dulal, Hari Prasad; Nagae, Masamichi; Ikeda, Akemi; Morita-Matsumoto, Kana; Adachi, Yoshiyuki; Ohno, Naohito; Yamaguchi, Yoshiki

    2016-07-01

    Dectin-1 is a C-type lectin-like pattern recognition receptor for β(1-3)-glucans. It plays a crucial role in protecting against fungal invasion through binding to β-glucans which are commonly present on the fungal cell wall. To probe its ligand binding mechanism by NMR, we expressed the recombinant murine Dectin-1 C-type lectin-like domain (CTLD) in E. coli using pCold vector and purified it. However, the high concentration of Dectin-1 CTLD required for NMR analysis could not be attained due to its inherent low solubility and low bacterial expression. In this study, we tried to increase expression and solubility of Dectin-1 CTLD by codon optimization and fusion of a GB1 tag (B1 domain of streptococcal Protein G). GB1 was inserted on either the N-terminal (NT) or C-terminal end as well as both terminal ends of human and mouse Dectin-1 CTLDs. A pure monomeric sample was only obtained with NT-GB1 fused mouse Dectin-1. Expression of mouse Dectin-1 CTLD yielded 0.9 ± 0.2 mg/L culture, codon optimized mouse Dectin-1 CTLD produced 1.4 ± 0.2 mg/L, and the tag-fused domain 7.1 ± 0.3 mg/L. The tag also increased solubility from 0.1 mM to 1.4 mM. The recombinant protein was correctly folded, in a monomeric state, and specifically bound β-glucan laminarin. These results indicate that fusing GB1 to the N-terminus of mouse Dectin-1 domain advantageously increases yield and solubility, allows retention of native structure, and that the site of fusion is critical. PMID:27062941

  18. Identification and characterization of C-type lectin genes from the reniform nematode

    Technology Transfer Automated Retrieval System (TEKTRAN)

    C-type lectins represent a large family of sugar-binding proteins which require calcium for their ligand-binding activity. C-type lectins play an important role in the innate immune response in all life forms when challenged by pathogens. Ligand binding occurs via conserved domain sequences which re...

  19. Mosquito C-type lectins maintain gut microbiome homeostasis.

    PubMed

    Pang, Xiaojing; Xiao, Xiaoping; Liu, Yang; Zhang, Rudian; Liu, Jianying; Liu, Qiyong; Wang, Penghua; Cheng, Gong

    2016-01-01

    The long-term evolutionary interaction between the host immune system and symbiotic bacteria determines their cooperative rather than antagonistic relationship. It is known that commensal bacteria have evolved a number of mechanisms to manipulate the mammalian host immune system and maintain homeostasis. However, the strategies employed by the microbiome to overcome host immune responses in invertebrates still remain to be understood. Here, we report that the gut microbiome in mosquitoes utilizes C-type lectins (mosGCTLs) to evade the bactericidal capacity of antimicrobial peptides (AMPs). Aedes aegypti mosGCTLs facilitate colonization by multiple bacterial strains. Furthermore, maintenance of the gut microbial flora relies on the expression of mosGCTLs in A. aegypti. Silencing the orthologues of mosGCTL in another major mosquito vector (Culex pipiens pallens) also impairs the survival of gut commensal bacteria. The gut microbiome stimulates the expression of mosGCTLs, which coat the bacterial surface and counteract AMP activity. Our study describes a mechanism by which the insect symbiotic microbiome offsets gut immunity to achieve homeostasis. PMID:27572642

  20. Mosquito C-type lectins maintain gut microbiome homeostasis

    PubMed Central

    Pang, Xiaojing; Xiao, Xiaoping; Liu, Yang; Zhang, Rudian; Liu, Jianying; Liu, Qiyong; Wang, Penghua; Cheng, Gong

    2016-01-01

    The long-term evolutionary interaction between the host immune system and symbiotic bacteria determines their cooperative rather than antagonistic relationship. It is known that commensal bacteria have evolved a number of mechanisms to manipulate the mammalian host immune system and maintain homeostasis. However, the strategies employed by the microbiome to overcome host immune responses in invertebrates still remain to be understood. Here, we report that the gut microbiome in mosquitoes utilizes C-type lectins (mosGCTLs) to evade the bactericidal capacity of antimicrobial peptides (AMPs). Aedes aegypti mosGCTLs facilitate colonization by multiple bacterial strains. Furthermore, maintenance of the gut microbial flora relies on the expression of mosGCTLs in A. aegypti. Silencing the orthologues of mosGCTL in another major mosquito vector (Culex pipiens pallens) also impairs the survival of gut commensal bacteria. The gut microbiome stimulates the expression of mosGCTLs, which coat the bacterial surface and counteract AMP activity. Our study describes a mechanism by which the insect symbiotic microbiome offsets gut immunity to achieve homeostasis. PMID:27170846

  1. Structural and biological characterization of Nattectin, a new C-type lectin from the venomous fish Thalassophryne nattereri.

    PubMed

    Lopes-Ferreira, Mônica; Magalhães, Geraldo Santana; Fernandez, Jorge Hernandez; Junqueira-de-Azevedo, Inácio de Loiola M; Le Ho, Paulo; Lima, Carla; Valente, Richard H; Moura-da-Silva, Ana Maria

    2011-06-01

    Lectins are glycan-binding receptors that recognize glycan epitopes on foreign pathogens and in the host systems. They can be involved in functions that include innate immunity, development, immune regulation and homeostasis. Several lectins have been purified and characterized from fish species. In this work, using cation-exchange chromatography, a galactose-specific lectin belonging to the family of C-type lectins was isolated from the venom of the Brazilian venomous fish Thalassophryne nattereri. Nattectin is a basic, non-glycosilated, 15 kDa monomeric protein. It exhibits hemagglutination activity that is independent of Ca(2+). We also demonstrated a lectin activity for Nattectin in the innate immune system, especially in neutrophil mobilization in mice, indicating that marine organisms are source of immunomodulator agents. PMID:21396978

  2. Cyanovirin-N inhibits mannose-dependent Mycobacterium-C-type lectin interactions but does not protect against murine tuberculosis

    PubMed Central

    Driessen, Nicole N.; Boshoff, Helena I.M.; Maaskant, Janneke J.; Gilissen, Sebastiaan A.C.; Vink, Simone; van der Sar, Astrid M.; Vandenbroucke-Grauls, Christina M.J.E.; Bewley, Carole A.; Appelmelk, Ben J.; Geurtsen, Jeroen

    2012-01-01

    Cyanovirin-N (CV-N) is a mannose-binding lectin that inhibits HIV-1 infection by blocking mannose-dependent target-cell entry via C-type lectins. Like HIV-1, Mycobacterium tuberculosis expresses mannosylated surface-structures and exploits C-type lectins to gain cell-access. Here we investigated whether CV-N, as for HIV-1, can inhibit M. tuberculosis infection. We found that CV-N specifically interacted with mycobacteria by binding to the mannose-capped lipoglycan lipoarabinomannan. Furthermore, CV-N competed with the C-type lectins DC-SIGN and mannose receptor for ligand binding and inhibited the binding of M. tuberculosis to dendritic cells but, unexpectedly, not to macrophages. Subsequent in vivo infection experiments in a mouse model demonstrated that CV-N, despite its activity, did not inhibit or delay M. tuberculosis infection. This outcome argues against a critical role for mannose-dependent C-type lectin interactions during initial stages of murine M. tuberculosis infection and suggests that, depending on the circumstances, M. tuberculosis can productively infect cells using different modes of entry. PMID:22942435

  3. A novel C-type lectin is involved in the innate immunity of Macrobrachium nipponense.

    PubMed

    Xiu, Yunji; Wang, Yinghui; Bi, Jingxiu; Liu, Yuhan; Ning, Mingxiao; Liu, Hui; Li, Shuang; Gu, Wei; Wang, Wen; Meng, Qingguo

    2016-03-01

    C-type lectins (CTLs) play important roles in invertebrate innate immunity by recognizing and eliminating pathogens. In the present study, a low-density lipoprotein receptor class A (LDLa) domain-containing CTL was identified from the oriental river prawn Macrobrachium nipponense, designated as MnCTLDcp1. The full-length cDNA of MnCTLDcp1 was composed of 1462 bp, with a 999-bp ORF encoding a 332-aa protein. An LDLa and a single C-type lectin-like domain (CTLD) were found. The mRNA transcripts of MnCTLDcp1 was expressed the highest in heart. After the prawns were challenged by Aeromonas hydrophila and Staphylococcus aureus, the expression level of MnCTLDcp1 in heart and hemocytes were all significantly up-regulated. Sugar binding assay revealed that the MnCTLDcp1 could bind to the glycoconjugates of bacteria surface, such as LPS, PGN and they can compete with bacterial as competitors. The recombinant MnCTLDcp1 agglutinates Gram-positive (S. aureus and Bacillus subtilis) and Gram-negative bacteria (A. hydrophila, Vibrio parahaemolyticus, Escherichia coli and Pseudomonas aeruginosa) in the presence of calcium and also could bind to these bacteria. These results clearly suggested that MnCTLDcp1 functions as a pattern-recognition receptor involved in the innate immunity of M. nipponense. PMID:26804648

  4. A C-type lectin is involved in the innate immune response of Chinese white shrimp.

    PubMed

    Wang, Xian-Wei; Xu, Wen-Teng; Zhang, Xiao-Wen; Zhao, Xiao-Fan; Yu, Xiao-Qiang; Wang, Jin-Xing

    2009-10-01

    C-type lectins may function as pattern-recognition receptors (PRRs) and play important roles in immune responses. In this work, a cDNA for a new C-type lectin, FcLec3, was obtained from Chinese white shrimp Fenneropenaeus chinensis using expressed sequence tag analysis and rapid amplification of the cDNA ends. FcLec3 contains an N-terminal signal peptide and a carbohydrate recognition domain (CRD). RT-PCR analysis showed that FcLec3 was mainly expressed in hepatopancreas and that the expression of FcLec3 was obviously up-regulated by Vibrio anguillarum or white spot syndrome virus (WSSV) challenge. Recombinant FcLec3 could agglutinate Gram-negative and -positive bacteria with the presence of calcium. A following agglutination inhibitory test indicated that FcLec3 could recognize muramic acid and peptidoglycan. Besides, pull-down assay showed that the recombinant protein could interact with VP28, one major envelope protein of WSSV. These results suggested that FcLec3 might function in the recognition of bacterial and viral pathogens in shrimp. PMID:19647083

  5. Differential Use of the C-Type Lectins L-SIGN and DC-SIGN for Phlebovirus Endocytosis.

    PubMed

    Léger, Psylvia; Tetard, Marilou; Youness, Berthe; Cordes, Nicole; Rouxel, Ronan N; Flamand, Marie; Lozach, Pierre-Yves

    2016-06-01

    Bunyaviruses represent a growing threat to humans and livestock globally. The receptors, cellular factors and endocytic pathways used by these emerging pathogens to infect cells remain largely unidentified and poorly characterized. DC-SIGN is a C-type lectin highly expressed on dermal dendritic cells that has been found to act as an authentic entry receptor for many phleboviruses (Bunyaviridae), including Rift Valley fever virus (RVFV), Toscana virus (TOSV) and Uukuniemi virus (UUKV). We found that these phleboviruses can exploit another C-type lectin, L-SIGN, for infection. L-SIGN shares 77% sequence homology with DC-SIGN and is expressed on liver sinusoidal endothelial cells. L-SIGN is required for UUKV binding but not for virus internalization. An endocytosis-defective mutant of L-SIGN was still able to mediate virus uptake and infection, indicating that L-SIGN acts as an attachment receptor for phleboviruses rather than an endocytic receptor. Our results point out a fundamental difference in the use of the C-type lectins L-SIGN and DC-SIGN by UUKV to enter cells, although both proteins are closely related in terms of molecular structure and biological function. This study sheds new light on the molecular mechanisms by which phleboviruses target the liver and also highlights the added complexity in virus-receptor interactions beyond attachment. PMID:26990254

  6. Critical roles of sea cucumber C-type lectin in non-self recognition and bacterial clearance.

    PubMed

    Wei, Xiumei; Liu, Xiangquan; Yang, Jianmin; Wang, Sheng; Sun, Guohua; Yang, Jialong

    2015-08-01

    C-type lectin is one important pattern recognition receptor (PRR) that plays crucial roles in multiple immune responses. A C-type lectin from sea cucumber Apostichopus japonicus (AjCTL-1) was characterized in the present study. The amino acid sequence of AjCTL-1 shared high similarities with other C-type lectins from invertebrates and vertebrates. The C-type lectin domain (CTLD) of AjCTL-1 contained a Ca(2+)-binding site 2 and four conserved cysteine residues. AjCTL-1 mRNA expression patterns in tissues and after bacterial challenge were then analysed. Quantitative PCR revealed that AjCTL-1 mRNA was widely expressed in the tested tissues of healthy sea cucumber. The highest expression level occurred in gonad followed by body wall, coelomocytes, tentacle, intestinum and longitudinal muscle, and the lowest expression level was in respiratory tree. AjCTL-1 mRNA expression in coelomocytes was significantly induced by gram-negative Listonella anguillarum and gram-positive Micrococcus luteus, with different up-regulation patterns post-challenge. Recombinant AjCTL-1 exhibited the ability to bind peptidoglycan directly, agglutinate M. luteus, Staphylococcus aureus and Escherichia coli, in a Ca(2+)-dependant manner, and enhance the phagocytosis of coelomocytes against E. coli in vitro. The results indicated that AjCTL-1 could act as a PRR in Apostichopus japonicus and had critical roles in non-self recognition and bacterial clearance against invading microbes. PMID:26052017

  7. C-type lectin receptor dectin-3 mediates trehalose 6,6'-dimycolate (TDM)-induced Mincle expression through CARD9/Bcl10/MALT1-dependent nuclear factor (NF)-κB activation.

    PubMed

    Zhao, Xue-Qiang; Zhu, Le-Le; Chang, Qing; Jiang, Changying; You, Yun; Luo, Tianming; Jia, Xin-Ming; Lin, Xin

    2014-10-24

    Previous studies indicate that both Dectin-3 (also called MCL or Clec4d) and Mincle (also called Clec4e), two C-type lectin receptors, can recognize trehalose 6,6'-dimycolate (TDM), a cell wall component from mycobacteria, and induce potent innate immune responses. Interestingly, stimulation of Dectin-3 by TDM can also induce Mincle expression, which may enhance the host innate immune system to sense Mycobacterium infection. However, the mechanism by which Dectin-3 induces Mincle expression is not fully defined. Here, we show that TDM-induced Mincle expression is dependent on Dectin-3-mediated NF-κB, but not nuclear factor of activated T-cells (NFAT), activation, and Dectin-3 induces NF-κB activation through the CARD9-BCL10-MALT1 complex. We found that bone marrow-derived macrophages from Dectin-3-deficient mice were severely defective in the induction of Mincle expression in response to TDM stimulation. This defect is correlated with the failure of TDM-induced NF-κB activation in Dectin-3-deficient bone marrow-derived macrophages. Consistently, inhibition of NF-κB, but not NFAT, impaired TDM-induced Mincle expression, whereas NF-κB, but not NFAT, binds to the Mincle promoter. Dectin-3-mediated NF-κB activation is dependent on the CARD9-Bcl10-MALT1 complex. Finally, mice deficient for Dectin-3 or CARD9 produced much less proinflammatory cytokines and keyhole limpet hemocyanin (KLH)-specific antibodies after immunization with an adjuvant containing TDM. Overall, this study provides the mechanism by which Dectin-3 induces Mincle expression in response to Mycobacterium infection, which will have significant impact to improve adjuvant and design vaccine for antimicrobial infection. PMID:25202022

  8. Lectins in the investigation of receptors

    NASA Astrophysics Data System (ADS)

    Lakhtin, V. M.; Yamskov, Igor A.

    1991-08-01

    Problems of the purification and characterisation are considered for approximately 270 receptors (including cell surface and organelle enzymes), which are glycoconjugates (mainly glycoproteins) from animals, plants and microorganisms, using various lectins (mainly lectin sorbents). An analysis has been carried out of the stages of lectin affinity chromatography of receptors (choice of detergent, use of organic solvents, elution with carbohydrates, etc.). Examples are given of procedures for the purification of receptors, including the use of paired columns and combination chromatography on lectins. The possibility of separating sub-populations of receptors using lectins has been demonstrated. Examples are given of the use of lectins in the analysis of the oligosaccharide structure of receptors. Cases are recorded of the interaction of receptors with endogenous lectins and of receptor lectins with endogenous glycoconjugates. It has been shown that lectins, in combination with glycosidases and antibodies, may be useful in the investigation of receptors. The bibliography contains 406 references.

  9. Characterization of beta-glucan recognition site on C-type lectin, dectin 1.

    PubMed

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

    2004-07-01

    Dectin 1 is a mammalian cell surface receptor for (1-->3)-beta-d-glucans. Since (1-->3)-beta-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 beta-glucan recognition. HEK293 cells transfected with mouse dectin 1 cDNA could bind to a gel-forming (1-->3)-beta-d-glucan, schizophyllan (SPG). The binding of SPG to a dectin 1 transfectant was inhibited by pretreatment with other beta-glucans having a (1-->3)-beta-d-glucosyl linkage but not by pretreatment with alpha-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 Trp(221) and His(223) resulted in decreased binding to beta-glucan. Monoclonal antibody 4B2, a dectin- 1 monoclonal antibody which had a blocking effect on the beta-glucan interaction, completely failed to bind the dectin-1 mutant W221A. A mutant with mutations in Trp(221) and His(223) 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 beta-glucan binding site in the CRD of dectin 1. PMID:15213161

  10. Antimicrobial properties of avian eggshell-specific C-type lectin-like proteins.

    PubMed

    Wellman-Labadie, Olivier; Lakshminarayanan, Rajamani; Hincke, Maxwell T

    2008-03-01

    C-type lectin-like proteins are major components of the calcified eggshell of multiple avian species. In this study, two representative avian C-type lectin-like proteins, ovocleidin-17 and ansocalcin, were purified from decalcified chicken and goose eggshell protein extracts and investigated for carbohydrate binding activity as well as antimicrobial activity. Purified ovocleidin-17 and ansocalcin were found to bind bacterial polysaccharides, and were bactericidal against Bacillus subtilis, Staphylococcus aureus and Pseudomona aeruginosa. Bactericidal activity was found to be enhanced in the presence of calcium but was not dependent on its presence. The results suggest that avian C-type lectin-like proteins may play an important antimicrobial role in defence of the avian embryo. PMID:18258195

  11. A C-Type Lectin from Bothrops jararacussu Venom Disrupts Staphylococcal Biofilms

    PubMed Central

    Klein, Raphael Contelli; Fabres-Klein, Mary Hellen; de Oliveira, Leandro Licursi; Feio, Renato Neves; Malouin, François; Ribon, Andréa de Oliveira Barros

    2015-01-01

    Bovine mastitis is a major threat to animal health and the dairy industry. Staphylococcus aureus is a contagious pathogen that is usually associated with persistent intramammary infections, and biofilm formation is a relevant aspect of the outcome of these infections. Several biological activities have been described for snake venoms, which led us to screen secretions of Bothrops jararacussu for antibiofilm activity against S. aureus NRS155. Crude venom was fractionated by size-exclusion chromatography, and the fractions were tested against S. aureus. Biofilm growth, but not bacterial growth, was affected by several fractions. Two fractions (15 and 16) showed the best activities and were also assayed against S. epidermidis NRS101. Fraction 15 was identified by TripleTOF mass spectrometry as a galactose-binding C-type lectin with a molecular weight of 15 kDa. The lectin was purified from the crude venom by D-galactose affinity chromatography, and only one peak was observed. This pure lectin was able to inhibit 75% and 80% of S. aureus and S. epidermidis biofilms, respectively, without affecting bacterial cell viability. The lectin also exhibited a dose-dependent inhibitory effect on both bacterial biofilms. The antibiofilm activity was confirmed using scanning electron microscopy. A pre-formed S. epidermidis biofilm was significantly disrupted by the C-type lectin in a time-dependent manner. Additionally, the lectin demonstrated the ability to inhibit biofilm formation by several mastitis pathogens, including different field strains of S. aureus, S. hyicus, S. chromogenes, Streptococcus agalactiae, and Escherichia coli. These findings reveal a new activity for C-type lectins. Studies are underway to evaluate the biological activity of these lectins in a mouse mastitis model. PMID:25811661

  12. A C-type lectin from Bothrops jararacussu venom disrupts Staphylococcal biofilms.

    PubMed

    Klein, Raphael Contelli; Fabres-Klein, Mary Hellen; de Oliveira, Leandro Licursi; Feio, Renato Neves; Malouin, François; Ribon, Andréa de Oliveira Barros

    2015-01-01

    Bovine mastitis is a major threat to animal health and the dairy industry. Staphylococcus aureus is a contagious pathogen that is usually associated with persistent intramammary infections, and biofilm formation is a relevant aspect of the outcome of these infections. Several biological activities have been described for snake venoms, which led us to screen secretions of Bothrops jararacussu for antibiofilm activity against S. aureus NRS155. Crude venom was fractionated by size-exclusion chromatography, and the fractions were tested against S. aureus. Biofilm growth, but not bacterial growth, was affected by several fractions. Two fractions (15 and 16) showed the best activities and were also assayed against S. epidermidis NRS101. Fraction 15 was identified by TripleTOF mass spectrometry as a galactose-binding C-type lectin with a molecular weight of 15 kDa. The lectin was purified from the crude venom by D-galactose affinity chromatography, and only one peak was observed. This pure lectin was able to inhibit 75% and 80% of S. aureus and S. epidermidis biofilms, respectively, without affecting bacterial cell viability. The lectin also exhibited a dose-dependent inhibitory effect on both bacterial biofilms. The antibiofilm activity was confirmed using scanning electron microscopy. A pre-formed S. epidermidis biofilm was significantly disrupted by the C-type lectin in a time-dependent manner. Additionally, the lectin demonstrated the ability to inhibit biofilm formation by several mastitis pathogens, including different field strains of S. aureus, S. hyicus, S. chromogenes, Streptococcus agalactiae, and Escherichia coli. These findings reveal a new activity for C-type lectins. Studies are underway to evaluate the biological activity of these lectins in a mouse mastitis model. PMID:25811661

  13. Direct recognition of the mycobacterial glycolipid, trehalose dimycolate, by C-type lectin Mincle

    PubMed Central

    Ishikawa, Eri; Ishikawa, Tetsuaki; Morita, Yasu S.; Toyonaga, Kenji; Yamada, Hisakata; Takeuchi, Osamu; Kinoshita, Taroh; Akira, Shizuo; Yoshikai, Yasunobu

    2009-01-01

    Tuberculosis remains a fatal disease caused by Mycobacterium tuberculosis, which contains various unique components that affect the host immune system. Trehalose-6,6′-dimycolate (TDM; also called cord factor) is a mycobacterial cell wall glycolipid that is the most studied immunostimulatory component of M. tuberculosis. Despite five decades of research on TDM, its host receptor has not been clearly identified. Here, we demonstrate that macrophage inducible C-type lectin (Mincle) is an essential receptor for TDM. Heat-killed mycobacteria activated Mincle-expressing cells, but the activity was lost upon delipidation of the bacteria; analysis of the lipid extracts identified TDM as a Mincle ligand. TDM activated macrophages to produce inflammatory cytokines and nitric oxide, which are completely suppressed in Mincle-deficient macrophages. In vivo TDM administration induced a robust elevation of inflammatory cytokines in sera and characteristic lung inflammation, such as granuloma formation. However, no TDM-induced lung granuloma was formed in Mincle-deficient mice. Whole mycobacteria were able to activate macrophages even in MyD88-deficient background, but the activation was significantly diminished in Mincle/MyD88 double-deficient macrophages. These results demonstrate that Mincle is an essential receptor for the mycobacterial glycolipid, TDM. PMID:20008526

  14. A four-CRD C-type lectin from Chlamys farreri mediating nonself-recognition with broader spectrum and opsonization.

    PubMed

    Huang, Mengmeng; Wang, Lingling; Yang, Jialong; Zhang, Huan; Wang, Leilei; Song, Linsheng

    2013-04-01

    C-type lectins are a superfamily of Ca(2+)-dependent carbohydrate-recognition proteins consisting of at least one carbohydrate-recognition domain (CRD), which participate in nonself-recognition and clearance of invaders. In invertebrate, some multidomain C-type lectins have been identified, but their relative functions and binding mechanism are still meager. In the present study, A C-type lectin (CfLec-4) with four CRDs from Chlamys farreri was selected to investigate its possible function in innate immunity. The mRNA expression of CfLec-4 in hemocytes was significantly up-regulated (P<0.01) after the stimulations of β-glucan, LPS or PGN, and reached the highest expression level at 3, 6, 12 h post-stimulation, which was 27.9-, 22.6- or 47.9-fold of that in blank group, respectively. Immunohistochemistry assay with polyclonal antibody specific for CfLec-4 revealed that the endogenous CfLec-4 was mainly located in the hepatopancreas, kidney and gonad of the scallops. The recombinant CfLec-4 (rCflec-4) could bind LPS, PGN, glucan and mannose in vitro, but could not bind LTA. Furthermore, rCflec-4 displayed a broader bacteria binding spectrum towards Gram-positive bacteria Staphylococcus aureus and Micrococcus luteus as well as Gram-negative bacteria Escherichia coli, Vibrio anguillarum and fungi Pichia pastoris. Meanwhile, rCfLec-4 could significantly (P<0.01) enhance the phagocytosis of hemocytes in vitro. The results clearly suggested that four-CRD containing CfLec-4 not only served as PRR with wider recognition spectrum, but also functioned as an opsonin participating in the clearance of invaders in scallops. It could be inferred that the diversity and complexity of CRDs in C-type lectins endowed these receptors with comprehensive recognition spectrum and multiple immune functions against complex living environment. PMID:23276881

  15. Fungal engagement of the C-type lectin mincle suppresses dectin-1-induced antifungal immunity.

    PubMed

    Wevers, Brigitte A; Kaptein, Tanja M; Zijlstra-Willems, Esther M; Theelen, Bart; Boekhout, Teun; Geijtenbeek, Teunis B H; Gringhuis, Sonja I

    2014-04-01

    Recognition of fungal pathogens by C-type lectin receptor (CLR) dectin-1 on human dendritic cells is essential for triggering protective antifungal TH1 and TH17 immune responses. We show that Fonsecaea monophora, a causative agent of chromoblastomycosis, a chronic fungal skin infection, evades these antifungal responses by engaging CLR mincle and suppressing IL-12, which drives TH1 differentiation. Dectin-1 triggering by F. monophora activates transcription factor IRF1, which is crucial for IL12A transcription via nucleosome remodeling. However, simultaneous F. monophora binding to mincle induces an E3 ubiquitin ligase Mdm2-dependent degradation pathway, via Syk-CARD9-mediated PKB signaling, that leads to loss of nuclear IRF1 activity, hence blocking IL12A transcription. The absence of IL-12 leads to impaired TH1 responses and promotes TH2 polarization. Notably, mincle is similarly exploited by other chromoblastomycosis-associated fungi to redirect TH responses. Thus, mincle is a fungal receptor that can suppress antifungal immunity and, as such, is a potential therapeutic target. PMID:24721577

  16. Isolation and characterization of two novel C-type lectins from the oriental river prawn, Macrobrachium nipponense.

    PubMed

    Xiu, Yunji; Hou, Libo; Liu, Xiaoqian; Wang, Yinghui; Gu, Wei; Meng, Qingguo; Wang, Wen

    2015-10-01

    C-type lectins are a family of calcium-dependent carbohydrate-binding proteins which are believed to play important roles in the innate immunity of invertebrates. This study identified two novel C-type lectins, designated as MnCTLDcp2 and MnCTLDcp3, from the oriental river prawn Macrobrachium nipponense. The full-length cDNA of MnCTLDcp2 was of 1582 bp with an open reading frame (ORF) of 972 bp encoding a polypeptide of 323 amino acids. The complete nucleotide sequence of MnCTLDcp3 cDNA was 583 bp, containing a 555 bp ORF encoding a putative protein of 184 deduced amino acids. The deduced MnCTLDcp2 and MnCTLDcp3 proteins both contained a single C-type lectin-like domain (CTLD). Besides, MnCTLDcp2 contains a signal peptide and an low-density lipoprotein receptor class A (LDLa) domain. Reverse transcription PCR showed that MnCTLDcp2 was expressed in the heart, gill, nerve hepatopancreas and intestine; MnCTLDcp3 was expressed in the hepatopancreas, heart, nerve, gill and muscle. Their expression in the heart tissue was regulated following challenge with bacteria. The microbial agglutination assay showed that both MnCTLDcp2 and MnCTLDcp3 could agglutinated bacteria in the presence of calcium. All these results suggested that MnCTLDcp2 and MnCTLDcp3 functioned as pattern recognition receptors in the immune system of M. nipponense. PMID:26208755

  17. Differential expression of two C-type lectins in grass carp Ctenopharyngodon idella and their response to grass carp reovirus.

    PubMed

    Ju, C S; He, L B; Pei, Y Y; Jiang, Y; Huang, R; Li, Y M; Liao, L J; Jang, S H; Wang, Y P

    2016-02-01

    The cDNAs of two C-type lectins in grass carp Ctenopharyngodon idella, galactose-binding lectin (galbl) and mannose-binding lectin (mbl), were cloned and analysed in this study. Both of them exhibited the highest expression level in liver, whereas their expression pattern differed in early phase of embryonic development. Following exposure to grass carp reovirus (GCRV), the mRNA expression level of galbl and mbl was significantly up-regulated in liver and intestine. PMID:26643267

  18. Antibacterial membrane attack by a pore-forming intestinal C-type lectin

    PubMed Central

    Mukherjee, Sohini; Zheng, Hui; Derebe, Mehabaw; Callenberg, Keith; Partch, Carrie L.; Rollins, Darcy; Propheter, Daniel C.; Rizo, Josep; Grabe, Michael; Jiang, Qiu-Xing; Hooper, Lora V.

    2014-01-01

    Summary Human body surface epithelia coexist in close association with complex bacterial communities and are protected by a variety of antibacterial proteins. C-type lectins of the RegIII family are bactericidal proteins that limit direct contact between bacteria and the intestinal epithelium and thus promote tolerance to the intestinal microbiota1,2. RegIII lectins recognize their bacterial targets by binding peptidoglycan carbohydrate1,3 but the mechanism by which they kill bacteria is unknown. Here we elucidate the mechanistic basis for RegIII bactericidal activity. Here we show that human RegIIIα (hRegIIIα, also known as HIP/PAP) binds membrane phospholipids and kills bacteria by forming a hexameric membrane-permeabilizing oligomeric pore. We derive a three-dimensional model of the hRegIIIα pore by docking the hRegIIIα crystal structure into a cryo-electron microscopic map of the pore complex, and show that the model accords with experimentally determined properties of the pore. Lipopolysaccharide inhibits hRegIIIα pore-forming activity, explaining why hRegIIIα is bactericidal for Gram-positive but not Gram-negative bacteria. Our findings identify C-type lectins as mediators of membrane attack in the mucosal immune system, and provide detailed insight into an antibacterial mechanism that promotes mutualism with the resident microbiota. PMID:24256734

  19. Tumor therapy in mice via antigen targeting to a novel, DC-restricted C-type lectin

    PubMed Central

    Sancho, David; Mourão-Sá, Diego; Joffre, Olivier P.; Schulz, Oliver; Rogers, Neil C.; Pennington, Daniel J.; Carlyle, James R.; Reis e Sousa, Caetano

    2008-01-01

    The mouse CD8α+ DC subset excels at cross-presentation of antigen, which can elicit robust CTL responses. A receptor allowing specific antigen targeting to this subset and its equivalent in humans would therefore be useful for the induction of antitumor CTLs. Here, we have characterized a C-type lectin of the NK cell receptor group that we named DC, NK lectin group receptor-1 (DNGR-1). DNGR-1 was found to be expressed in mice at high levels by CD8+ DCs and at low levels by plasmacytoid DCs but not by other hematopoietic cells. Human DNGR-1 was also restricted in expression to a small subset of blood DCs that bear similarities to mouse CD8α+ DCs. The selective expression pattern and observed endocytic activity of DNGR-1 suggested that it could be used for antigen targeting to DCs. Consistent with this notion, antigen epitopes covalently coupled to an antibody specific for mouse DNGR-1 were selectively cross-presented by CD8α+ DCs in vivo and, when given with adjuvants, induced potent CTL responses. When the antigens corresponded to tumor-expressed peptides, treatment with the antibody conjugate and adjuvant could prevent development or mediate eradication of B16 melanoma lung pseudometastases. We conclude that DNGR-1 is a novel, highly specific marker of mouse and human DC subsets that can be exploited for CTL cross-priming and tumor therapy. PMID:18497879

  20. Characterization of Multisugar-Binding C-Type Lectin (SpliLec) from a Bacterial-Challenged Cotton Leafworm, Spodoptera littoralis

    PubMed Central

    Seufi, AlaaEddeen M.; Galal, Fatma H.; Hafez, Elsayed E.

    2012-01-01

    Background Various proteins that display carbohydrate-binding activity in a Ca2+-dependent manner are classified into the C-type lectin family. They have one or two C-type carbohydrate-recognition domains (CRDs) composed of 110–130 amino acid residues in common. C-type lectins mediate cell adhesion, non-self recognition, and immuno-protection processes in immune responses and thus play significant roles in clearance of invaders, either as cell surface receptors for microbial carbohydrates or as soluble proteins existing in tissue fluids. The lectin of Spodoptera littoralis is still uncharacterized. Methodology A single orf encoding a deduced polypeptide consisting of an 18-residue signal peptide and a 291-residue mature peptide, termed SpliLec, was isolated from the haemolymph of the cotton leafworm, S. littoralis, after bacterial challenge using RACE-PCR. Sequence analyses of the data revealed that SpliLec consists of two CRDs. Short-form CRD1 and long-form CRD2 are stabilized by two and three highly conserved disulfide bonds, respectively. SpliLec shares homology with some dipteran lectins suggesting possible common ancestor. The purified SpliLec exhibited a 140-kDa molecular mass with a subunit molecular mass of 35 kDa. The hemagglutination assays of the SpliLec confirmed a thermally stable, multisugar-binding C-type lectin that binds different erythrocytes. The purified SpliLec agglutinated microorganisms and exhibited comparable antimicrobial activity against gram (+) and gram (−) bacteria too. Conclusions Our results suggested an important role of the SpliLec gene in cell adhesion and non-self recognition. It may cooperate with other AMPs in clearance of invaders of Spodoptera littoralis. PMID:22916161

  1. Isolation and cloning of a C-type lectin from the hexactinellid sponge Aphrocallistes vastus: a putative aggregation factor.

    PubMed

    Gundacker, D; Leys, S P; Schröder, H C; Müller, I M; Müller, W E

    2001-01-01

    Among the sponges (Porifera), the oldest group of metazoans in phylogenetic terms, the Hexactinellida is considered to have diverged earliest from the two other sponge classes, the Demospongiae and Calcarea. The Hexactinellida are unusual among all Metazoa in possessing mostly syncytial rather than cellular tissues. Here we describe the purification of a cell adhesion molecule with a size of 34 kDa (in its native form; 24 kDa after deglycosylation) from the hexactinellid sponge Aphrocallistes vastus. This adhesion molecule was previously found to agglutinate preserved cells and membranes in a non-species-specific manner (Müller, W. E. G., Zahn, R. K, Conrad, J., Kurelec, B., and Uhlenbruck, G. [1984] Cell adhesion molecules in the haxactinellid Aphrocallistes vastus: species-unspecific aggregationfactor. Differentiation, 26, 30--35). The fact that the aggregation process required Ca(2+) and was inhibited by bird's nest glycoprotein and D-galactose but not by D-mannose or N-acetyl-D-galactosamine suggests that this cell adhesion molecule is a C-type lectin. To test this assumption, two highly similar C-type lectins were cloned from A.vastus. The deduced polypeptides of the two cDNA species isolated classified these molecules as C-type lectins. The calculated M(r) of the 191 aa long sequences were 22,022 and 22,064, respectively. The C-type lectins showed highest similarity to C-type lectins (type-II membrane proteins) from higher metazoan phyla; these molecules are absent in non-Metazoa. The two sponge C-type lectins contain the conserved domains known from other C-type lectins (e.g., disulfide bonds, the amino acids known to be involved in Ca(2+)-binding, as well as the amino acids involved in the specificity of binding to D-galactose) and a hydrophobic N-terminal region. The N-terminal part of the purified C-type lectin was identical with the corresponding region of the deduced polypeptide from the cDNA. It is proposed that the A.vastus lectins might bind to the

  2. Collaboration between a soluble C-type lectin and calreticulin facilitates white spot syndrome virus infection in shrimp.

    PubMed

    Wang, Xian-Wei; Xu, Yi-Hui; Xu, Ji-Dong; Zhao, Xiao-Fan; Wang, Jin-Xing

    2014-09-01

    White spot syndrome virus (WSSV) mainly infects crustaceans through the digestive tract. Whether C-type lectins (CLs), which are important receptors for many viruses, participate in WSSV infection in the shrimp stomach remains unknown. In this study, we orally infected kuruma shrimp Marsupenaeus japonicus to model the natural transmission of WSSV and identified a CL (designated as M. japonicus stomach virus-associated CL [MjsvCL]) that was significantly induced by virus infection in the stomach. Knockdown of MjsvCL expression by RNA interference suppressed the virus replication, whereas exogenous MjsvCL enhanced it. Further analysis by GST pull-down and coimmunoprecipitation showed that MjsvCL could bind to viral protein 28, the most abundant and functionally relevant envelope protein of WSSV. Furthermore, cell-surface calreticulin was identified as a receptor of MjsvCL, and the interaction between these proteins was a determinant for the viral infection-promoting activity of MjsvCL. The MjsvCL-calreticulin pathway facilitated virus entry likely in a cholesterol-dependent manner. This study provides insights into a mechanism by which soluble CLs capture and present virions to the cell-surface receptor to facilitate viral infection. PMID:25070855

  3. The Structure of the Poxvirus A33 Protein Reveals a Dimer of Unique C-Type Lectin-Like Domains

    SciTech Connect

    Su, Hua-Poo; Singh, Kavita; Gittis, Apostolos G.; Garboczi, David N.

    2010-11-03

    The current vaccine against smallpox is an infectious form of vaccinia virus that has significant side effects. Alternative vaccine approaches using recombinant viral proteins are being developed. A target of subunit vaccine strategies is the poxvirus protein A33, a conserved protein in the Chordopoxvirinae subfamily of Poxviridae that is expressed on the outer viral envelope. Here we have determined the structure of the A33 ectodomain of vaccinia virus. The structure revealed C-type lectin-like domains (CTLDs) that occur as dimers in A33 crystals with five different crystal lattices. Comparison of the A33 dimer models shows that the A33 monomers have a degree of flexibility in position within the dimer. Structural comparisons show that the A33 monomer is a close match to the Link module class of CTLDs but that the A33 dimer is most similar to the natural killer (NK)-cell receptor class of CTLDs. Structural data on Link modules and NK-cell receptor-ligand complexes suggest a surface of A33 that could interact with viral or host ligands. The dimer interface is well conserved in all known A33 sequences, indicating an important role for the A33 dimer. The structure indicates how previously described A33 mutations disrupt protein folding and locates the positions of N-linked glycosylations and the epitope of a protective antibody.

  4. Human CLEC18 Gene Cluster Contains C-type Lectins with Differential Glycan-binding Specificity.

    PubMed

    Huang, Ya-Lang; Pai, Feng-Shuo; Tsou, Yun-Ting; Mon, Hsien-Chen; Hsu, Tsui-Ling; Wu, Chung-Yi; Chou, Teh-Ying; Yang, Wen-Bin; Chen, Chung-Hsuan; Wong, Chi-Huey; Hsieh, Shie-Liang

    2015-08-28

    The human C-type lectin 18 (clec18) gene cluster, which contains three clec18a, clec18b, and clec18c loci, is located in human chromosome 16q22. Although the amino acid sequences of CLEC18A, CLEC18B, and CLEC18C are almost identical, several amino acid residues located in the C-type lectin-like domain (CTLD) and the sperm-coating protein/Tpx-1/Ag5/PR-1/Sc7 (SCP/TAPS) domain, also known as the cysteine-rich secretory proteins/antigen 5/pathogenesis-related 1 proteins (CAP) domain, are distinct from each other. Genotyping by real-time PCR and sequencing further shows the presence of multiple alleles in clec18a/b/c loci. Flow cytometry analysis demonstrates that CLEC18 (CLEC18A, -B, and -C) are expressed abundantly in human peripheral blood cells. Moreover, CLEC18 expression is further up-regulated when monocytes differentiate into macrophages and dendritic cells. Immunofluorescence staining reveals that CLEC18 are localized in the endoplasmic reticulum, Golgi apparatus, and endosome. Interestingly, CLEC18 are also detectable in human sera and culture supernatants from primary cells and 293T cells overexpressing CLEC18. Moreover, CLEC18 bind polysaccharide in Ca(2+)-independent manner, and amino acid residues Ser/Arg(339) and Asp/Asn(421) in CTLD domain contribute to their differential binding abilities to polysaccharides isolated from Ganoderma lucidum (GLPS-F3). The Ser(339) (CLEC18A) → Arg(339) (CLEC18A-1) mutation completely abolishes CLEC18A-1 binding to GLPS-F3, and a sugar competition assay shows that CLEC18 preferentially binds to fucoidan, β-glucans, and galactans. Because proteins with the SCP/TAPS/CAP domain are able to bind sterol and acidic glycolipid, and are involved in sterol transport and β-amyloid aggregation, it would be interesting to investigate whether CLEC18 modulates host immunity via binding to glycolipids, and are also involved in glycolipid transportation and protein aggregation in the future. PMID:26170455

  5. Differential expression of skin mucus C-type lectin in two freshwater eel species, Anguilla marmorata and Anguilla japonica.

    PubMed

    Tsutsui, Shigeyuki; Yoshinaga, Tatsuki; Komiya, Kaoru; Yamashita, Hiroka; Nakamura, Osamu

    2016-08-01

    Two types of lactose-specific lectins, galectin (AJL-1) and C-type lectin (AJL-2), were previously identified in the mucus of adult Anguilla japonica. Here, we compared the expression profiles of these two homologous lectins at the adult and juvenile stages between the tropical eel Anguilla marmorata and the temperate eel A. japonica. Only one lectin, predicted to be an orthologue of AJL-1 by LC-MS/MS, was detected in the mucus of adult A. marmorata. We also found that an orthologous gene to AJL-2 was expressed at very low levels, or not at all, in the skin of adult A. marmorata. However, we detected the gene expression of an AJL-2-orthologue in the skin of juvenile A. marmorata, and a specific antibody also detected the lectin in the juvenile fish epidermis. These findings suggest that expression profiles of mucosal lectins vary during development as well as between species in the Anguilla genus. PMID:27026508

  6. New structural insights into the molecular deciphering of mycobacterial lipoglycan binding to C-type lectins: lipoarabinomannan glycoform characterization and quantification by capillary electrophoresis at the subnanomole level.

    PubMed

    Nigou, J; Vercellone, A; Puzo, G

    2000-06-23

    Lipoarabinomannans are key molecules of the mycobacterial envelopes involved in many steps of tuberculosis immunopathogenesis. Several of the biological activities of lipoarabinomannans are mediated by their ability to bind human C-type lectins, such as the macrophage mannose receptor, the mannose-binding protein and the surfactant proteins A and D. The lipoarabinomannan mannooligosaccharide caps have been demonstrated to be involved in the binding to the lectin carbohydrate recognition domains. We report an original analytical approach, based on capillary electrophoresis monitored by laser-induced fluorescence, allowing the absolute quantification, in nanomole quantities of lipoarabinomannan, of the number of mannooligosaccharide units per lipoarabinomannan molecule. Moreover, this analytical approach was successful for the glycosidic linkage determination of the mannooligosaccharide motifs and has been applied to the comparative analysis of parietal and cellular lipoarabinomannans of Mycobacterium bovis BCG and Mycobacterium tuberculosis H37Rv, H37Ra and Erdman strains. Significant differences were observed in the amounts of the various mannooligosaccharide units between lipoarabinomannans of different strains and between parietal and cellular lipoarabinomannans of the same strain. Nevertheless, no relationship was found between the number of mannooligosaccharide caps and the virulence of the corresponding strain. The results of the present study should help us to gain more understanding of the molecular basis of lipoarabinomannan discrimination in the process of binding to C-type lectins. PMID:10873458

  7. Super-Resolution Imaging of C-Type Lectin and Influenza Hemagglutinin Nanodomains on Plasma Membranes Using Blink Microscopy

    PubMed Central

    Itano, Michelle S.; Steinhauer, Christian; Schmied, Jürgen J.; Forthmann, Carsten; Liu, Ping; Neumann, Aaron K.; Thompson, Nancy L.; Tinnefeld, Philip; Jacobson, Ken

    2012-01-01

    Dendritic cells express DC-SIGN, a C-type lectin (CTL) that binds a variety of pathogens and facilitates their uptake for subsequent antigen presentation. DC-SIGN forms remarkably stable microdomains on the plasma membrane. However, inner leaflet lipid markers are able to diffuse through these microdomains suggesting that, rather than being densely packed with DC-SIGN proteins, an elemental substructure exists. Therefore, a super-resolution imaging technique, Blink Microscopy (Blink), was applied to further investigate the lateral distribution of DC-SIGN. Blink indicates that DC-SIGN, another CTL (CD206), and influenza hemagglutinin (HA) are all localized in small (∼80 nm in diameter) nanodomains. DC-SIGN and CD206 nanodomains are randomly distributed on the plasma membrane, whereas HA nanodomains cluster on length scales up to several microns. We estimate, as a lower limit, that DC-SIGN and HA nanodomains contain on average two tetramers or two trimers, respectively, whereas CD206 is often nonoligomerized. Two-color Blink determined that different CTLs rarely occupy the same nanodomain, although they appear colocalized using wide-field microscopy. What to our knowledge is a novel domain structure emerges in which elemental nanodomains, potentially capable of binding viruses, are organized in a random fashion; evidently, these nanodomains can be clustered into larger microdomains that act as receptor platforms for larger pathogens like yeasts. PMID:22500753

  8. A Shrimp C-type Lectin Inhibits Proliferation of the Hemolymph Microbiota by Maintaining the Expression of Antimicrobial Peptides*

    PubMed Central

    Wang, Xian-Wei; Xu, Ji-Dong; Zhao, Xiao-Fan; Vasta, Gerardo Raul; Wang, Jin-Xing

    2014-01-01

    Some aquatic invertebrates such as shrimp contain low albeit stable numbers of bacteria in the circulating hemolymph. The proliferation of this hemolymph microbiota in such a nutrient-rich environment is tightly controlled in healthy animals, but the mechanisms responsible had remained elusive. In the present study, we report a C-type lectin (MjHeCL) from the kuruma shrimp (Marsupenaeus japonicus) that participates in restraining the hemolymph microbiota. Although the expression of MjHeCL did not seem to be modulated by bacterial challenge, the down-regulation of its expression by RNA interference led to proliferation of the hemolymph microbiota, ultimately resulting in shrimp death. This phenotype was rescued by the injection of recombinant MjHeCL, which restored the healthy status of the knockdown shrimp. A mechanistic analysis revealed that MjHeCL inhibited bacterial proliferation by modulating the expression of antimicrobial peptides. The key function of MjHeCL in the shrimp immune homeostasis might be related to its broader recognition spectrum of the hemolymph microbiota components than other lectins. Our study demonstrates the role of MjHeCL in maintaining the healthy status of shrimp and provides new insight into the biological significance of C-type lectins, a diversified and abundant lectin family in invertebrate species. PMID:24619414

  9. A C-type lectin with an immunoglobulin-like domain promotes phagocytosis of hemocytes in crayfish Procambarus clarkii

    PubMed Central

    Zhang, Xiao-Wen; Wang, Yue; Wang, Xian-Wei; Wang, Lei; Mu, Yi; Wang, Jin-Xing

    2016-01-01

    C-type lectins are important immune molecules that participate in host defense response. The present work reports a novel C-type lectin (PcLec3) from the red swamp crayfish Procambarus clarkii. Sequence analysis found that PcLec3 encodes a polypeptide with252 amino acid residues, which contains an immunoglobulin-like domain (IG) and a C-type lectin domain (CTLD) arranged in tandem. Tissue distribution analysis indicated that PcLec3 is enriched expressed in hemocytes and hepatopancreas cells, in which PcLec3 was up-regulated following bacterial challenge by Vibrio anguillarum. Function analysis using recombinant full-length PcLec3, IG, and CTLD proteins revealed that these recombinant proteins had the capacity to bind carbohydrates and bacteria, while IG determined the cell binding activity. However, only full-length PcLec3 promotes the phagocytic activity of hemocytes and subsequent clearance of invasive bacteria. Taken together, these results manifest that PcLec3 acts as a hemocyte adhesion molecule to promote hemocyte phagocytosis against invasive V. anguillarum. PMID:27411341

  10. A C-type lectin with an immunoglobulin-like domain promotes phagocytosis of hemocytes in crayfish Procambarus clarkii.

    PubMed

    Zhang, Xiao-Wen; Wang, Yue; Wang, Xian-Wei; Wang, Lei; Mu, Yi; Wang, Jin-Xing

    2016-01-01

    C-type lectins are important immune molecules that participate in host defense response. The present work reports a novel C-type lectin (PcLec3) from the red swamp crayfish Procambarus clarkii. Sequence analysis found that PcLec3 encodes a polypeptide with252 amino acid residues, which contains an immunoglobulin-like domain (IG) and a C-type lectin domain (CTLD) arranged in tandem. Tissue distribution analysis indicated that PcLec3 is enriched expressed in hemocytes and hepatopancreas cells, in which PcLec3 was up-regulated following bacterial challenge by Vibrio anguillarum. Function analysis using recombinant full-length PcLec3, IG, and CTLD proteins revealed that these recombinant proteins had the capacity to bind carbohydrates and bacteria, while IG determined the cell binding activity. However, only full-length PcLec3 promotes the phagocytic activity of hemocytes and subsequent clearance of invasive bacteria. Taken together, these results manifest that PcLec3 acts as a hemocyte adhesion molecule to promote hemocyte phagocytosis against invasive V. anguillarum. PMID:27411341

  11. Galactose recognition by a tetrameric C-type lectin, CEL-IV, containing the EPN carbohydrate recognition motif.

    PubMed

    Hatakeyama, Tomomitsu; Kamiya, Takuro; Kusunoki, Masami; Nakamura-Tsuruta, Sachiko; Hirabayashi, Jun; Goda, Shuichiro; Unno, Hideaki

    2011-03-25

    CEL-IV is a C-type lectin isolated from a sea cucumber, Cucumaria echinata. This lectin is composed of four identical C-type carbohydrate-recognition domains (CRDs). X-ray crystallographic analysis of CEL-IV revealed that its tetrameric structure was stabilized by multiple interchain disulfide bonds among the subunits. Although CEL-IV has the EPN motif in its carbohydrate-binding sites, which is known to be characteristic of mannose binding C-type CRDs, it showed preferential binding of galactose and N-acetylgalactosamine. Structural analyses of CEL-IV-melibiose and CEL-IV-raffinose complexes revealed that their galactose residues were recognized in an inverted orientation compared with mannose binding C-type CRDs containing the EPN motif, by the aid of a stacking interaction with the side chain of Trp-79. Changes in the environment of Trp-79 induced by binding to galactose were detected by changes in the intrinsic fluorescence and UV absorption spectra of WT CEL-IV and its site-directed mutants. The binding specificity of CEL-IV toward complex oligosaccharides was analyzed by frontal affinity chromatography using various pyridylamino sugars, and the results indicate preferential binding to oligosaccharides containing Galβ1-3/4(Fucα1-3/4)GlcNAc structures. These findings suggest that the specificity for oligosaccharides may be largely affected by interactions with amino acid residues in the binding site other than those determining the monosaccharide specificity. PMID:21247895

  12. Identification and Characterization of a Spliced C-Type Lectin-Like Gene Encoded by Rat Cytomegalovirus

    PubMed Central

    Voigt, Sebastian; Sandford, Gordon R.; Ding, Lijun; Burns, William H.

    2001-01-01

    The English isolate of rat cytomegalovirus (RCMV) encodes a 20-kDa protein with a C-type lectin-like domain that is expressed in the delayed-early and late phases of the viral replication cycle. Genomic sequence analysis of the restriction fragment KpnR of RCMV revealed significant homology to several C-type lectin-containing molecules implicated in natural killer (NK) and T-cell interactions, as well as genes from four poxviruses and African swine fever virus. The gene is spliced into five exons and shows a splicing pattern with exon boundaries similar to those observed in the human differentiation antigen CD69. The cap site of the gene was mapped by RNase protection, 5′ rapid amplification of cDNA ends, and primer extension experiments. This analysis demonstrated that the core promoter of the RCMV lectin-like gene contains a GATA rather than a TATA box. Splicing patterns were confirmed with isolates from an infected-cell cDNA library. A unique aspect of the protein is that its translation is not initiated by the canonical methionine but rather by alanine. To study its role in virus replication and pathogenesis, a recombinant virus was constructed in which the gene is interrupted. Replication in tissue culture was similar to that of wild-type virus. PMID:11134273

  13. CfLec-3 from scallop: an entrance to non-self recognition mechanism of invertebrate C-type lectin

    PubMed Central

    Yang, Jialong; Huang, Mengmeng; Zhang, Huan; Wang, Lingling; Wang, Hao; Wang, Leilei; Qiu, Limei; Song, Linsheng

    2015-01-01

    A C-type lectin (CfLec-3) from Chlamys farreri with three carbohydrate-recognition domains (CRDs) was selected to dissect the possible mechanisms of PAMP binding and functional differentiation of invertebrate lectins. CfLec-3 distributed broadly, and its mRNA expression in hemocytes increased significantly after stimulations with LPS, PGN or β-glucan, but not poly(I:C). The recombinant CfLec-3 (rCfLec-3) could bind PAMPs and several microbes. rCfLec-3 mediated hemocytes phagocytosis against Escherichia coli and encapsulation towards agarose beads. Obvious functional differentiation occurred among the three CRDs, as CRD1 exhibited higher activity to bind PAMPs, while CRD2/3 were expert in promoting hemocyte mediated opsonisation. The tertiary structural differences were suspected to be associated with such functional differentiation. PAMP binding abilities of CfLec-3 were determined by Ca2+-binding site 2 motif. When Pro in this motif of each CRD was mutated into Ser, their PAMP binding abilities were deprived absolutely. rCRD2 acquired mannan binding capability when its EPD was replaced by EPN, but lost when EPN in rCRD3 was changed into EPD. The Pro in Ca2+-binding site 2 was indispensable for PAMPs binding, while Asn was determinant for specific binding to mannan. It shed new insight into PAMPs binding mechanism of invertebrate C-type lectins and their functional differentiation. PMID:25975813

  14. Genetic variability in the rat Aplec C-type lectin gene cluster regulates lymphocyte trafficking and motor neuron survival after traumatic nerve root injury

    PubMed Central

    2013-01-01

    Background C-type lectin (CLEC) receptors are important for initiating and shaping immune responses; however, their role in inflammatory reactions in the central nervous system after traumatic injuries is not known. The antigen-presenting lectin-like receptor gene complex (Aplec) contains a few CLEC genes, which differ genetically among inbred rat strains. It was originally thought to be a region that regulates susceptibility to autoimmune arthritis, autoimmune neuroinflammation and infection. Methods The inbred rat strains DA and PVG differ substantially in degree of spinal cord motor neuron death following ventral root avulsion (VRA), which is a reproducible model of localized nerve root injury. A large F2 (DAxPVG) intercross was bred and genotyped after which global expressional profiling was performed on spinal cords from F2 rats subjected to VRA. A congenic strain, Aplec, created by transferring a small PVG segment containing only seven genes, all C-type lectins, ontoDA background, was used for further experiments together with the parental strains. Results Global expressional profiling of F2 (DAxPVG) spinal cords after VRA and genome-wide eQTL mapping identified a strong cis-regulated difference in the expression of Clec4a3 (Dcir3), a C-type lectin gene that is a part of the Aplec cluster. Second, we demonstrate significantly improved motor neuron survival and also increased T-cell infiltration into the spinal cord of congenic rats carrying Aplec from PVG on DA background compared to the parental DA strain. In vitro studies demonstrate that the Aplec genes are expressed on microglia and upregulated upon inflammatory stimuli. However, there were no differences in expression of general microglial activation markers between Aplec and parental DA rats, suggesting that the Aplec genes are involved in the signaling events rather than the primary activation of microglia occurring upon nerve root injury. Conclusions In summary, we demonstrate that a genetic variation

  15. Molecular cloning and expression analysis of mannose receptor C type 1 in grass carp (Ctenopharyngodon idella).

    PubMed

    Wang, Li; Liu, Lichun; Zhou, Yang; Zhao, Xiaoheng; Xi, Mingjun; Wei, Shun; Fang, Rui; Ji, Wei; Chen, Nan; Gu, Zemao; Liu, Xueqin; Wang, Weimin; Asim, Muhammad; Liu, Xiaoling; Lin, Li

    2014-03-01

    Mannose receptor C type 1 (MRC1) is a pattern-recognition receptor (PRR) which plays a significant role in immune responses. Much work on MRC1 has been done in mammals and birds while little in fish. In this study, we cloned and characterized MRC1 in grass carp (gcMR). The full-length gcMR contained 5291bp encoding a putative protein of 1432 amino acids. The predicted amino acid sequences showed that gcMR contained a signal peptide, a cysteine-rich (CR) domain, a fibronectin type II (FN II) domain, eight C-type lectin-like domains (CTLDs), a transmembrane domain and a short cytoplasmic domain. gcMR were constitutively expressed in different organs with the higher expression in spleen and head kidney. During embryonic development, gcMR transcript levels were highest at cleavage stage. The up-regulation expression of gcMR, IL-1β and TNF-α in liver, spleen, head kidney and intestine after Aeromonas hydrophila infection indicating it involved in innate immune regulation during bacterial infections. PMID:24184700

  16. Molecular cloning and characterization of a C-type lectin from Ancylostoma ceylanicum: evidence for a role in hookworm reproductive physiology.

    PubMed Central

    Brown, Allison C.; Harrison, Lisa M.; Kapulkin, Wadim; Jones, Brian F.; Sinha, Anindita; Savage, Amy; Villalon, Nicholas; Cappello, Michael

    2007-01-01

    Lectins comprise a family of related proteins that mediate essential cell functions through binding to carbohydrates. Within this protein family, C-type lectins are defined by the requirement of calcium for optimal biologic activity. Using reverse transcription PCR, a cDNA corresponding to a putative C-type lectin has been amplified from the hookworm parasite Ancylostoma ceylanicum. The 550 nucleotide open reading frame of the Ancylostoma ceylanicum C-type Lectin-1 (AceCTL-1) cDNA corresponds to a 167 amino acid mature protein (18706 Da) preceded by a 17 amino acid secretory signal sequence. The recombinant protein (rAceCTL-1) was expressed in Drosophila S2 cells and purified using a combination of affinity chromatography and reverse phase HPLC. Using in vitro carbohydrate binding studies, it was determined that rAceCTL-1 binds N-acetyl-D-glucosamine, a common component of eukaryotic egg cell membranes. Using a polyclonal IgG raised against the recombinant protein, the native AceCTL-1 was identified in sperm and soluble protein extracts of adult male A. ceylanicum by immunoblot. Probing of adult hookworm sections with the polyclonal IgG demonstrated localization to the testes in males, as well as the spermatheca and developing embryos in females, consistent with its role as a sperm protein. Together, these data strongly suggest that AceCTL-1 is a male gender-specific C-type lectin with a function in hookworm reproductive physiology. PMID:17129620

  17. C-type lectin-like carbohydrate recognition of the hemolytic lectin CEL-III containing ricin-type -trefoil folds.

    PubMed

    Hatakeyama, Tomomitsu; Unno, Hideaki; Kouzuma, Yoshiaki; Uchida, Tatsuya; Eto, Seiichiro; Hidemura, Haruki; Kato, Norihisa; Yonekura, Masami; Kusunoki, Masami

    2007-12-28

    CEL-III is a Ca(2+)-dependent hemolytic lectin, isolated from the marine invertebrate Cucumaria echinata. The three-dimensional structure of CEL-III/GalNAc and CEL-III/methyl alpha-galactoside complexes was solved by x-ray crystallographic analysis. In these complexes, five carbohydrate molecules were found to be bound to two carbohydrate-binding domains (domains 1 and 2) located in the N-terminal 2/3 portion of the polypeptide and that contained beta-trefoil folds similar to ricin B-chain. The 3-OH and 4-OH of bound carbohydrate molecules were coordinated with Ca(2+) located at the subdomains 1alpha, 1gamma, 2alpha, 2beta, and 2gamma, simultaneously forming hydrogen bond networks with nearby amino acid side chains, which is similar to carbohydrate binding in C-type lectins. The binding of carbohydrates was further stabilized by aromatic amino acid residues, such as tyrosine and tryptophan, through a stacking interaction with the hydrophobic face of carbohydrates. The importance of amino acid residues in the carbohydrate-binding sites was confirmed by the mutational analyses. The orientation of bound GalNAc and methyl alpha-galactoside was similar to the galactose moiety of lactose bound to the carbohydrate-binding site of the ricin B-chain, although the ricin B-chain does not require Ca(2+) ions for carbohydrate binding. The binding of the carbohydrates induced local structural changes in carbohydrate-binding sites in subdomains 2alpha and 2beta. Binding of GalNAc also induced a slight change in the main chain structure of domain 3, which could be related to the conformational change upon binding of specific carbohydrates to induce oligomerization of the protein. PMID:17977832

  18. The Neck Region of the C-type Lectin DC-SIGN Regulates Its Surface Spatiotemporal Organization and Virus-binding Capacity on Antigen-presenting Cells*

    PubMed Central

    Manzo, Carlo; Torreno-Pina, Juan A.; Joosten, Ben; Reinieren-Beeren, Inge; Gualda, Emilio J.; Loza-Alvarez, Pablo; Figdor, Carl G.; Garcia-Parajo, Maria F.; Cambi, Alessandra

    2012-01-01

    The C-type lectin DC-SIGN expressed on dendritic cells (DCs) facilitates capture and internalization of a plethora of different pathogens. Although it is known that DC-SIGN organizes in nanoclusters at the surface of DCs, the molecular mechanisms responsible for this well defined nanopatterning and role in viral binding remain enigmatic. By combining biochemical and advanced biophysical techniques, including optical superresolution and single particle tracking, we demonstrate that DC-SIGN intrinsic nanoclustering strictly depends on its molecular structure. DC-SIGN nanoclusters exhibited free, Brownian diffusion on the cell membrane. Truncation of the extracellular neck region, known to abrogate tetramerization, significantly reduced nanoclustering and concomitantly increased lateral diffusion. Importantly, DC-SIGN nanocluster dissolution exclusively compromised binding to nanoscale size pathogens. Monte Carlo simulations revealed that heterogeneity on nanocluster density and spatial distribution confers broader binding capabilities to DC-SIGN. As such, our results underscore a direct relationship between spatial nanopatterning, driven by intermolecular interactions between the neck regions, and receptor diffusion to provide DC-SIGN with the exquisite ability to dock pathogens at the virus length scale. Insight into how virus receptors are organized prior to virus binding and how they assemble into functional platforms for virus docking is helpful to develop novel strategies to prevent virus entry and infection. PMID:23019323

  19. Interaction of Helicobacter pylori with C-Type Lectin Dendritic Cell-Specific ICAM Grabbing Nonintegrin

    PubMed Central

    Miszczyk, Eliza; Rudnicka, Karolina; Moran, Anthony P.; Fol, Marek; Kowalewicz-Kulbat, Magdalena; Druszczyńska, Magdalena; Matusiak, Agnieszka; Walencka, Maria; Rudnicka, Wiesława; Chmiela, Magdalena

    2012-01-01

    In this study we asked whether Helicobacter pylori whole cells and lipopolysaccharide (LPS) utilize sugar moieties of Lewis (Le) antigenic determinants to interact with DC-SIGN (dendritic cell specific ICAM grabbing nonintegrin) receptor on dendritic cells (DCs). For this purpose the soluble DC-SIGN/Fc adhesion assay and the THP-1 leukemia cells with induced expression of DC-SIGN were used. We showed that the binding specificity of DC-SIGN with H. pylori LeX/Y positive whole cells and H. pylori LPS of LeX/Y type was fucose dependent, whereas in LeXY negative H. pylori strains and LPS preparations without Lewis determinants, this binding was galactose dependent. The binding of soluble synthetic LeX and LeY to the DC-SIGN-like receptor on THP-1 cells was also observed. In conclusion, the LeXY dependent as well as independent binding of H. pylori whole cells and H. pylori LPS to DC-SIGN was described. Moreover, we demonstrated that THP-1 cells may serve as an in vitro model for the assessment of H. pylori-DC-SIGN interactions mediated by LeX and LeY determinants. PMID:22550396

  20. Conservation of the C-type lectin fold for massive sequence variation in a Treponema diversity-generating retroelement

    SciTech Connect

    Le Coq, Johanne; Ghosh, Partho

    2012-06-19

    Anticipatory ligand binding through massive protein sequence variation is rare in biological systems, having been observed only in the vertebrate adaptive immune response and in a phage diversity-generating retroelement (DGR). Earlier work has demonstrated that the prototypical DGR variable protein, major tropism determinant (Mtd), meets the demands of anticipatory ligand binding by novel means through the C-type lectin (CLec) fold. However, because of the low sequence identity among DGR variable proteins, it has remained unclear whether the CLec fold is a general solution for DGRs. We have addressed this problem by determining the structure of a second DGR variable protein, TvpA, from the pathogenic oral spirochete Treponema denticola. Despite its weak sequence identity to Mtd ({approx}16%), TvpA was found to also have a CLec fold, with predicted variable residues exposed in a ligand-binding site. However, this site in TvpA was markedly more variable than the one in Mtd, reflecting the unprecedented approximate 10{sup 20} potential variability of TvpA. In addition, similarity between TvpA and Mtd with formylglycine-generating enzymes was detected. These results provide strong evidence for the conservation of the formylglycine-generating enzyme-type CLec fold among DGRs as a means of accommodating massive sequence variation.

  1. Hemolytic C-type lectin CEL-III from sea cucumber expressed in transgenic mosquitoes impairs malaria parasite development.

    PubMed

    Yoshida, Shigeto; Shimada, Yohei; Kondoh, Daisuke; Kouzuma, Yoshiaki; Ghosh, Anil K; Jacobs-Lorena, Marcelo; Sinden, Robert E

    2007-12-01

    The midgut environment of anopheline mosquitoes plays an important role in the development of the malaria parasite. Using genetic manipulation of anopheline mosquitoes to change the environment in the mosquito midgut may inhibit development of the malaria parasite, thus blocking malaria transmission. Here we generate transgenic Anopheles stephensi mosquitoes that express the C-type lectin CEL-III from the sea cucumber, Cucumaria echinata, in a midgut-specific manner. CEL-III has strong and rapid hemolytic activity toward human and rat erythrocytes in the presence of serum. Importantly, CEL-III binds to ookinetes, leading to strong inhibition of ookinete formation in vitro with an IC(50) of 15 nM. Thus, CEL-III exhibits not only hemolytic activity but also cytotoxicity toward ookinetes. In these transgenic mosquitoes, sporogonic development of Plasmodium berghei is severely impaired. Moderate, but significant inhibition was found against Plasmodium falciparum. To our knowledge, this is the first demonstration of stably engineered anophelines that affect the Plasmodium transmission dynamics of human malaria. Although our laboratory-based research does not have immediate applications to block natural malaria transmission, these findings have significant implications for the generation of refractory mosquitoes to all species of human Plasmodium and elucidation of mosquito-parasite interactions. PMID:18159942

  2. A single CRD C-type lectin from Eriocheir sinensis (EsLecB) with microbial-binding, antibacterial prophenoloxidase activation and hem-encapsulation activities.

    PubMed

    Fang, Zi-Yan; Li, Dan; Li, Xue-Jie; Zhang, Xing; Zhu, You-Ting; Li, Wei-Wei; Wang, Qun

    2016-03-01

    C-type lectins (CTLs) exist widely in crustaceans. To date, thirteen CTLs have been reported in crustaceans, and play significant roles in pathogen recognition, encapsulation of hemocytes and antimicrobial activity in the innate immune response. Based on the initial expressed sequence tags (EST) of a hepatopancreatic cDNA library, a novel CTL, designated as EsLecB, with a 470 bp open reading frame encodes a polypeptide of 156 amino acids, including a signal peptide of 19 amino acid residues and one carbohydrate-recognition domain of 131 aa residues, was cloned from the crustacean Eriocheir sinensis. By qRT-PCR analysis, EsLecB was detected in all tested tissues, and showed highest expression in hemocytes, hepatopancreas and heart. The expression of EsLecB was up-regulated following injections of PAMPs or bacteria. The recombinant protein (rEsLecB) expressed in Escherichia coli had a calcium-independent but carbohydrate-dependent microbial-binding and microbial-agglutinating, microorganism growth inhibitory and hem-encapsulation activities. Moreover, the rEsLecB could stimulate the activation of prophenoloxidase in vitro. These results indicated that EsLecB, as an antibacterial pattern recognition receptor is involved in innate immunity, and may act as an upstream detector of the prophenoloxidase activating system, which can detect pathogen invasion in E. sinensis. PMID:26826423

  3. CLEC-38, a transmembrane protein with C-type lectin-like domains, negatively regulates UNC-40-mediated axon outgrowth and promotes presynaptic development in Caenorhabditis elegans.

    PubMed

    Kulkarni, Gauri; Li, Haichang; Wadsworth, William G

    2008-04-23

    In the developing nervous system, axons respond to various guidance cues to find their targets. The effects guidance cues have on an axon may change as an axon undergoes morphological changes, such as branching, turning, and synapse formation. The means by which these changes are regulated are not well understood. In Caenorhabditis elegans, the UNC-40/DCC (deleted in colorectal cancer) receptor mediates responses to the UNC-6/netrin guidance cue. Here, we show that CLEC-38, a protein with predicted transmembrane and C-type lectin-like domains, regulates UNC-40-mediated axon outgrowth as well as the organization of presynaptic terminals. We observe that, in genetic backgrounds sensitized for axon guidance defects, loss of clec-38 function can suppress defects in an UNC-40-dependent manner. Within migrating axons, clec-38 acts cell autonomously. Furthermore, loss of clec-38 function alters UNC-40::GFP (green fluorescent protein) expression. We also observe that loss of clec-38 function disrupts presynaptic patterning in animals with normal axon guidance and that there are genetic interactions between clec-38 and rpm-1, which encodes a protein implicated in regulating presynaptic assembly and axon morphology. We suggest CLEC-38 plays a role in promoting synapse assembly and refining axon outgrowth activity. PMID:18434533

  4. Mitogenic activity of CEL-I, an N-acetylgalactosamine (GalNAc)-specific C-type lectin, isolated from the marine invertebrate Cucumaria echinata (Holothuroidea).

    PubMed

    Jiang, Zedong; Kim, Daekyung; Yamasaki, Yasuhiro; Yamanishi, Tomohiro; Hatakeyama, Tomomitsu; Yamaguchi, Kenichi; Oda, Tatsuya

    2010-01-01

    An N-acetylgalactosamine (GalNAc)-specific Ca(2+)-dependent lectin (C-type lectin), isolated from the marine invertebrate Holothuroidea (Cucumaria echinata), CEL-I, showed potent mitogenic activity toward normal mouse spleen cells. The mitogenic activity of CEL-I, which reached a maximum at 100 microg/ml, was inhibited by GalNAc in a concentration-dependent manner. The mitogenic effect of CEL-I at 10 microg/ml on T cell- enriched splenocytes was at a similar level due to a well-known T cell mitogen, concanavalin A (Con A), at 10 microg/ml. Furthermore, CEL-I evoked a mitogenic response from nude mouse spleen cells, while no significant effects of Con A on this cell population were observed over a wide range of concentrations. These results suggest that CEL-I is a potent mitogenic lectin with the ability to stimulate both T and B cells. PMID:20699569

  5. Crystallization and preliminary crystallographic study of an invertebrate C-type lectin, CEL-I, from the marine invertebrate Cucumaria echinata.

    PubMed

    Hatakeyama, Tomomitsu; Matsuo, Noriaki; Aoyagi, Haruhiko; Sugawara, Hajime; Uchida, Tatsuya; Kurisu, Genji; Kusunoki, Masami

    2002-01-01

    CEL-I is a GalNAc-specific carbohydrate-binding protein (lectin) isolated from the sea cucumber Cucumaria echinata. This protein belongs to the widely distributed C-type lectin family of animal lectins, which require Ca(2+) for their carbohydrate-binding ability and play important roles in various molecular-recognition processes in organisms. CEL-I was crystallized with 2-methyl-2,4-pentanediol using the hanging-drop vapour-diffusion technique. The CEL-I crystals belong to the monoclinic space group C2, with unit-cell parameters a = 92.38 (3), b = 69.94 (3), c = 76.69 (3) A, beta = 136.46 (2) degrees. Diffraction data were collected to 2.0 A resolution using synchrotron radiation. The asymmetric unit contains one CEL-I molecule. PMID:11752793

  6. A C-type lectin MGL1/CD301a plays an anti-inflammatory role in murine experimental colitis.

    PubMed

    Saba, Kengo; Denda-Nagai, Kaori; Irimura, Tatsuro

    2009-01-01

    Inflammatory bowel disease is caused by abnormal inflammatory and immune responses to harmless substances, such as commensal bacteria, in the large bowel. Such responses appear to be suppressed under healthy conditions, although the mechanism of such suppression is currently unclear. The present study aimed to reveal whether the recognition of bacterial surface carbohydrates by the macrophage galactose-type C-type lectin-1, MGL1/CD301a, induces both the production and secretion of interleukin (IL)-10. Dextran sulfate sodium salt (DSS) was orally administrated to mice that lacked MGL1/CD301a (Mgl1(-/-) mice) and their wild-type littermates. Mgl1(-/-) mice showed significantly more severe inflammation than wild-type mice after administration of DSS. MGL1-positive cells in the colonic lamina propria corresponded to macrophage-like cells with F4/80-high, CD11b-positive, and CD11c-intermediate expression. These cells in Mgl1(-/-) mice produced a lower level of IL-10 mRNA compared with wild-type mice after the administration of DSS for 2 days. Recombinant MGL1 was found to bind both Streptococcus sp. and Lactobacillus sp. among commensal bacteria isolated from mesenteric lymph nodes of DSS-treated mice. Heat-killed Streptococcus sp. induced an increase in IL-10 secretion by MGL1-positive colonic lamina propria macrophages, but not the macrophage population from Mgl1(-/-) mice. These results strongly suggest that MGL1/CD301a plays a protective role against colitis by effectively inducing IL-10 production by colonic lamina propria macrophages in response to invading commensal bacteria. PMID:19095961

  7. Novel sequences encoding venom C-type lectins are conserved in phylogenetically and geographically distinct Echis and Bitis viper species.

    PubMed

    Harrison, R A; Oliver, J; Hasson, S S; Bharati, K; Theakston, R D G

    2003-10-01

    Envenoming by Echis saw scaled vipers and Bitis arietans puff adders is the leading cause of death and morbidity in Africa due to snake bite. Despite their medical importance, the composition and constituent functionality of venoms from these vipers remains poorly understood. Here, we report the cloning of cDNA sequences encoding seven clusters or isoforms of the haemostasis-disruptive C-type lectin (CTL) proteins from the venom glands of Echis ocellatus, E. pyramidum leakeyi, E. carinatus sochureki and B. arietans. All these CTL sequences encoded the cysteine scaffold that defines the carbohydrate-recognition domain of mammalian CTLs. All but one of the Echis and Bitis CTL sequences showed greater sequence similarity to the beta than alpha CTL subunits in venoms of related Asian and American vipers. Four of the new CTL clusters showed marked inter-cluster sequence conservation across all four viper species which were significantly different from that of previously published viper CTLs. The other three Echis and Bitis CTL clusters showed varying degrees of sequence similarity to published viper venom CTLs. Because viper venom CTLs exhibit a high degree of sequence similarity and yet exert profoundly different effects on the mammalian haemostatic system, no attempt was made to assign functionality to the new Echis and Bitis CTLs on the basis of sequence alone. The extraordinary level of inter-specific and inter-generic sequence conservation exhibited by the Echis and Bitis CTLs leads us to speculate that antibodies to representative molecules should neutralise the biological function of this important group of venom toxins in vipers that are distributed throughout Africa, the Middle East and the Indian subcontinent. PMID:14557069

  8. Super-resolution imaging of C-type lectin spatial rearrangement within the dendritic cell plasma membrane at fungal microbe contact sites

    NASA Astrophysics Data System (ADS)

    Itano, Michelle; Graus, Matthew; Pehlke, Carolyn; Wester, Michael; Liu, Ping; Lidke, Keith; Thompson, Nancy; Jacobson, Ken; Neumann, Aaron

    2014-08-01

    Dendritic cells express DC-SIGN and CD206, C-type lectins (CTLs) that bind a variety of pathogens and may facilitate pathogen uptake for subsequent antigen presentation. Both proteins form punctate membrane nanodomains (~80 nm) on naïve cells. We analyzed the spatiotemporal distribution of CTLs following host-fungal particle contact using confocal microscopy and three distinct methods of cluster identification and measurement of receptor clusters in super-resolution datasets: DBSCAN, Pair Correlation and a custom implementation of the Getis spatial statistic. Quantitative analysis of confocal and super-resolution images demonstrated that CTL nanodomains become concentrated in the contact site relative to non-contact membrane after the first hour of exposure and established that this recruitment is sustained out to four hours. DC-SIGN nanodomains in fungal contact sites exhibit a 70% area increase and a 38% decrease in interdomain separation. Contact site CD206 nanodomains possess 90% greater area and 42% lower interdomain separation relative to non-contact regions. Contact site CTL clusters appear as disk-shaped domains of approximately 150-175 nm in diameter. The increase in length scale of CTL nanostructure in contact sites suggests that the smaller nanodomains on resting membranes may merge during fungal nanodomain structure, or that they become packed closely enough to achieve sub-resolution inter-domain edge separations of < 30 nm. This study provides evidence of local receptor spatial rearrangements on the nanoscale that occur in the plasma membrane upon pathogen binding and may direct important signaling interactions required to recognize and respond to the presence of a relatively large pathogen.

  9. 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. PMID:25826155

  10. A single-CRD C-type lectin from oyster Crassostrea gigas mediates immune recognition and pathogen elimination with a potential role in the activation of complement system.

    PubMed

    Li, Hui; Zhang, Huan; Jiang, Shuai; Wang, Weilin; Xin, Lusheng; Wang, Hao; Wang, Lingling; Song, Linsheng

    2015-06-01

    C-type lectins (CTLs), serving as pattern recognition receptors (PRRs), are a superfamily of Ca(2+)-dependent carbohydrate-recognition proteins that participate in nonself-recognition and pathogen elimination. In the present study, a single carbohydrate-recognition domain (CRD) CTL was identified from oyster Crassostrea gigas (designated as CgCLec-2). There was only one CRD within the deduced amino acid sequence of CgCLec-2 consisting of 129 amino acid residues. A conserved EPN (Glu246-Pro247-Asn248) motif was found in Ca(2+)-binding site 2 of CgCLec-2. The CgCLec-2 mRNA could be detected in all the examined tissues at different expression levels in oysters. The mRNA expression of CgCLec-2 in hemocytes was up-regulated significantly at 6 h post Vibrio splendidus challenge. The recombinant CgCLec-2 (rCgCLec-2) could bind various Pathogen-Associated Molecular Patterns (PAMPs), including lipopolysaccharide, mannan and peptidoglycan, and displayed strong binding abilities to Vibrio anguillarum, V. splendidus and Yarrowiali polytica and week binding ability to Staphylococcus aureus. It could also enhance the phagocytic activity of oyster hemocytes to V. splendidus and exhibited growth suppression activity against gram-positive bacteria S. aureus but no effect on gram-negative bacteria V. splendidus. Furthermore, the interaction between rCgCLec-2 and rCgMASPL-1 was confirmed by GST Pull down. The results suggested that CgCLec-2 served as not only a PRR in immune recognition but also a regulatory factor in pathogen elimination, and played a potential role in the activation of complement system. PMID:25800112

  11. Preferential induction of CD4+ T cell responses through in vivo targeting of antigen to dendritic cell-associated C-type lectin-1.

    PubMed

    Carter, Robert W; Thompson, Clare; Reid, Delyth M; Wong, Simon Y C; Tough, David F

    2006-08-15

    Targeting of Ags and therapeutics to dendritic cells (DCs) has immense potential for immunotherapy and vaccination. Because DCs are heterogeneous, optimal targeting strategies will require knowledge about functional specialization among DC subpopulations and identification of molecules for targeting appropriate DCs. We characterized the expression of a fungal recognition receptor, DC-associated C-type lectin-1 (Dectin-1), on mouse DC subpopulations and investigated the ability of an anti-Dectin-1 Ab to deliver Ag for the stimulation of immune responses. Dectin-1 was shown to be expressed on CD8alpha-CD4-CD11b+ DCs found in spleen and lymph nodes and dermal DCs present in skin and s.c. lymph nodes. Injection of Ag-anti-Dectin-1 conjugates induced CD4+ and CD8+ T cell and Ab responses at low doses where free Ag failed to elicit a response. Notably, qualitatively different immune responses were generated by targeting Ag to Dectin-1 vs CD205, a molecule expressed on CD8alpha+CD4-CD11b- DCs, dermal DCs, and Langerhans cells. Unlike anti-Dectin-1, anti-CD205 conjugates failed to elicit an Ab response. Moreover, when conjugates were injected i.v., anti-Dectin-1 stimulated a much stronger CD4+ T cell response and a much weaker CD8+ T cell response than anti-CD205. The results reveal Dectin-1 as a potential targeting molecule for immunization and have implications for the specialization of DC subpopulations. PMID:16887988

  12. Ophioluxin, a convulxin-like C-type lectin from Ophiophagus hannah (King cobra) is a powerful platelet activator via glycoprotein VI.

    PubMed

    Du, Xiao-Yan; Clemetson, Jeannine M; Navdaev, Alexei; Magnenat, Edith M; Wells, Timothy N C; Clemetson, Kenneth J

    2002-09-20

    Ophioluxin, a potent platelet agonist, was purified from the venom of Ophiophagus hannah (King cobra). Under nonreducing conditions it has a mass of 85 kDa, similar to convulxin, and on reduction gives two subunits with masses of 16 and 17 kDa, slightly larger than those of convulxin. The N-terminal sequences of both subunits are very similar to those of convulxin and other C-type lectins. Ophioluxin induces a pattern of tyrosine-phosphorylated proteins in platelets like that caused by convulxin, when using appropriate concentrations based on aggregation response, because it is about 2-4 times more powerful as agonist than the latter. Ophioluxin and convulxin induce [Ca(2+)](i) elevation both in platelets and in Dami megakaryocytic cells, and each of these C-type lectins desensitizes responses to the other. Convulxin agglutinates fixed platelets at 2 microg/ml, whereas ophioluxin does not, even at 80 microg/ml. Ophioluxin resembles convulxin more than echicetin or alboaggregin B because polyclonal anti-ophioluxin antibodies recognize both ophioluxin and convulxin, but not echicetin, and platelets adhere to and spread on ophioluxin- or convulxin-precoated surfaces in the same way that is clearly different from their behavior on an alboaggregin B surface. Immobilized ophioluxin was used to isolate the glycoprotein VI-Fcgamma complex from resting platelets, which also contained Fyn, Lyn, Syk, LAT, and SLP76. Ophioluxin is the first multiheterodimeric, convulxin-like snake C-type lectin, as well as the first platelet agonist, to be described from the Elapidae snake family. PMID:12130642

  13. 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. PMID:1030938

  14. A novel C-type lectin with four CRDs is involved in the regulation of antimicrobial peptide gene expression in Hyriopsis cumingii.

    PubMed

    Zhao, Ling-Ling; Wang, Yu-Qing; Dai, Yun-Jia; Zhao, Li-Juan; Qin, Qiwei; Lin, Li; Ren, Qian; Lan, Jiang-Feng

    2016-08-01

    C-type lectins (CTLs) are found in a wide number of invertebrates, and have been reported to participate in immune responses, such as the activation of prophenoloxidase, cell adhesion, bacterial clearance and phagocytosis. Previous studies on CTLs focused on the function of their carbohydrate recognition domains (CRDs). Currently, studies on lectins with multi-CRDs are limited. In this study, a lectin with four CRDs was cloned from Hyriopsis cumingii, and called HcLec4. HcLec4 was widely distributed in several tissues and was significantly down-regulated at the early stage (2 h) of bacterial infection. We further analyzed the bacteria and carbohydrate binding activities of HcLec4. The results showed that HcLec4 could bind to several bacteria, lipopolysaccharide (LPS) and peptidoglycan (PGN). In HcLec4 knockdown mussels, the bacterial clearance rate was increased, and the expression level of antimicrobial peptides (AMPs) was up-regulated. This study reveals that HcLec4 exerts its antibacterial effect by regulating the expression of AMPs at the early stage of bacterial infection. PMID:27288254

  15. Alteration of the carbohydrate-binding specificity of a C-type lectin CEL-I mutant with an EPN carbohydrate-binding motif.

    PubMed

    Hatakeyama, Tomomitsu; Ishimine, Tomohiro; Baba, Tomohiro; Kimura, Masanari; Unno, Hideaki; Goda, Shuichiro

    2013-07-01

    CEL-I is a Gal/GalNAc-specific C-type lectin isolated from the sea cucumber Cucumaria echinata. This lectin is composed of two carbohydrate-recognition domains (CRDs) with the carbohydrate-recognition motif QPD (Gln-Pro- Asp), which is generally known to exist in galactose-specific C-type CRDs. In the present study, a mutant CEL-I with EPN (Glu-Pro-Asn) motif, which is thought to be responsible for the carbohydrate-recognition of mannose-specific Ctype CRDs, was produced in Escherichia coli, and its effects on the carbohydrate-binding specificity were examined using polyamidoamine dendrimer (PD) conjugated with carbohydrates. Although wild-type CEL-I effectively formed complexes with N-acetylgalactosamine (GalNAc)-PD but not with mannose-PD, the mutant CEL-I showed relatively weak but definite affinity for mannose-PD. These results indicated that the QPD and EPN motifs play a significant role in the carbohydrate-recognition mechanism of CEL-I, especially in the discrimination of galactose and mannose. Additional mutations in the recombinant CEL-I binding site may further increase its specificity for mannose, and should provide insights into designing novel carbohydrate-recognition proteins. PMID:23157284

  16. The Cryptosporidium parvum C-Type Lectin CpClec Mediates Infection of Intestinal Epithelial Cells via Interactions with Sulfated Proteoglycans.

    PubMed

    Ludington, Jacob G; Ward, Honorine D

    2016-05-01

    The apicomplexan parasite Cryptosporidium causes significant diarrheal disease worldwide. Effective anticryptosporidial agents are lacking, in part because the molecular mechanisms underlying Cryptosporidium-host cell interactions are poorly understood. Previously, we identified and characterized a novel Cryptosporidium parvum C-type lectin domain-containing mucin-like glycoprotein, CpClec. In this study, we evaluated the mechanisms underlying interactions of CpClec with intestinal epithelial cells by using an Fc-tagged recombinant protein. CpClec-Fc displayed Ca(2+)-dependent, saturable binding to HCT-8 and Caco-2 cells and competitively inhibited C. parvum attachment to and infection of HCT-8 cells. Binding of CpClec-Fc was specifically inhibited by sulfated glycosaminoglycans, particularly heparin and heparan sulfate. Binding was reduced after the removal of heparan sulfate and following the inhibition of glycosaminoglycan synthesis or sulfation in HCT-8 cells. Like CpClec-Fc binding, C. parvum attachment to and infection of HCT-8 cells were inhibited by glycosaminoglycans and were reduced after heparan sulfate removal or inhibition of glycosaminoglycan synthesis or sulfation. Lastly, CpClec-Fc binding and C. parvum sporozoite attachment were significantly decreased in CHO cell mutants defective in glycosaminoglycan synthesis. Together, these results indicate that CpClec is a novel C-type lectin that mediates C. parvum attachment and infection via Ca(2+)-dependent binding to sulfated proteoglycans on intestinal epithelial cells. PMID:26975991

  17. Characteristic recognition of N-acetylgalactosamine by an invertebrate C-type Lectin, CEL-I, revealed by X-ray crystallographic analysis.

    PubMed

    Sugawara, Hajime; Kusunoki, Masami; Kurisu, Genji; Fujimoto, Tokiko; Aoyagi, Haruhiko; Hatakeyama, Tomomitsu

    2004-10-22

    CEL-I is a C-type lectin, purified from the sea cucumber Cucumaria echinata, that shows a high specificity for N-acetylgalactosamine (GalNAc). We determined the crystal structures of CEL-I and its complex with GalNAc at 2.0 and 1.7 A resolution, respectively. CEL-I forms a disulfide-linked homodimer and contains two intramolecular disulfide bonds, although it lacks one intramolecular disulfide bond that is widely conserved among various C-type carbohydrate recognition domains (CRDs). Although the sequence similarity of CEL-I with other C-type CRDs is low, the overall folding of CEL-I was quite similar to those of other C-type CRDs. The structure of the complex with GalNAc revealed that the basic recognition mode of GalNAc was very similar to that for the GalNAc-binding mutant of the mannose-binding protein. However, the acetamido group of GalNAc appeared to be recognized more strongly by the combination of hydrogen bonds to Arg115 and van der Waals interaction with Gln70. Mutational analyses, in which Gln70 and/or Arg115 were replaced by alanine, confirmed that these residues contributed to GalNAc recognition in a cooperative manner. PMID:15319425

  18. A novel C-type lectin, Nattectin-like protein, with a wide range of bacterial agglutination activity in large yellow croaker Larimichthys crocea.

    PubMed

    Lv, Changhuan; Zhang, Dongling; Wang, Zhiyong

    2016-03-01

    C-type lectins (CTLs) are generally recognized as a superfamily of Ca(2+)-dependent carbohydrate-binding proteins, which serve as pattern recognition receptors (PRRs) in innate immunity of vertebrates. In this study, the molecular characterization and immune roles of a novel CTL from Larimichthys crocea (designated as LcNTC) were investigated. LcNTC is a novel protein that shared 33%-49% homology with other teleosts CTLs. The full-length cDNA of LcNTC was composed of 859 bp with a 465 bp open reading frame encoding a putative protein of 154 residues. LcNTC contained a single CRD with four conserved disulfide-bonded cysteine residues (Cys(57)-Cys(148), Cys(126)-Cys(140)) and EPN/AND motifs instead of invariant EPN/WND motifs required for carbohydrate-binding specificity and constructing Ca(2+)-binding sites. LcNTC mRNA was detected in all examined tissues with the most abundant in the gill. After challenged with poly I:C and Vibrio parahaemolyticus, the temporal expression of LcNTC was significantly up-regulated in the liver, spleen and head-kidney. LcNTC transcripts were also induced in the gill, skin, spleen and head-kidney post-infection with Cryptocaryon irritans. The recombinant LcNTC (rLcNTC) purified from Escherichia coli BL21 (DE3) exhibited strong agglutination activity against erythrocytes from human, rabbit and large yellow croaker in a Ca(2+)-dependent manner, and the agglutination could be inhibited by D-Mannose, D-Glucose, D-Fructose, α-Lactose, D-Maltose and LPS. Positive microbial agglutination activities of rLcNTC were observed against all tested bacteria in the presence of Ca(2+), including Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus and Micrococcus lysoleikticus) and Gram-negative bacteria (E. coli, V. parahaemolyticus, Vibrio alginolyticus and Aeromonas hydrophila). These findings collectively indicated that LcNTC might be involved in the innate immunity of L. crocea as a PRR. PMID:26828263

  19. Cytotoxicity of a GalNAc-specific C-type lectin CEL-I toward various cell lines.

    PubMed

    Kuramoto, Takuya; Uzuyama, Hitomi; Hatakeyama, Tomomitsu; Tamura, Tadashi; Nakashima, Takuji; Yamaguchi, Kenichi; Oda, Tatsuya

    2005-01-01

    We found that CEL-I was a potent cytotoxic lectin. MDCK, HeLa, and XC cells were highly sensitive to CEL-I cytotoxicity and killed in a dose-dependent manner, whereas CHO, L929, and RAW264.7 cells were relatively resistant to CEL-I, and no significant toxicity was observed up to 10 microg/ml. Among these cell lines, MDCK cells showed the highest susceptibility to CEL-I cytotoxicity. A binding study using FITC-labeled CEL-I (F-CEL-I) revealed that the amounts of bound F-CEL-I on the sensitive cell lines were evidently greater than those on the resistant cell lines, suggesting that the different susceptibility of the cell lines to CEL-I cytotoxicity is partly explained by different efficiencies of binding of CEL-I to these cell lines. Interestingly, the cytotoxicity of CEL-I toward MDCK cells was more potent than those of other lectins such as WGA, PHA-L, and Con A, even though these lectins were capable of binding to MDCK cells at comparable levels to CEL-I. Since the cytotoxicity of CEL-I was strongly inhibited by GalNAc, the binding to cell surface specific carbohydrates is essential for the CEL-I cytotoxicity. The trypan blue dye exclusion test indicated that CEL-I caused a disorder of plasma membrane integrity as a relatively early event. CEL-I failed to induce the release of carboxyfluorescein (CF) from CF-loaded MDCK cells as seen for pore-forming hemolytic isolectin CEL-III, suggesting that the primary cellular target of CEL-I may be the plasma membrane, but its action mechanism differs from that of CEL-III. Although CEL-I induced dramatic cellular morphological changes in MDCK cells, neither typical apoptotic nuclear morphological changes nor DNA fragmentation was observed in CEL-I-treated MDCK cells even after such cellular changes. Our results demonstrated that CEL-I showed a potent cytotoxic effect, especially on MDCK cells, by causing plasma membrane disorder without induction of apoptosis. PMID:15713882

  20. Dedicated immunosensing of the mouse intestinal epithelium facilitated by a pair of genetically coupled lectin-like receptors.

    PubMed

    Leibelt, S; Friede, M E; Rohe, C; Gütle, D; Rutkowski, E; Weigert, A; Kveberg, L; Vaage, J T; Hornef, M W; Steinle, A

    2015-03-01

    The integrity of the intestinal epithelium is constantly surveyed by a peculiar subset of innate-like T lymphocytes embedded in the epithelial cell layer, hence called intestinal intraepithelial lymphocytes (IELs). IELs are thought to act as "first-line" sentinels sensing the state of adjacent epithelial cells via both T-cell receptors and auxiliary receptors. Auxiliary receptors modulating IEL activity include C-type lectin-like receptors encoded in the natural killer gene complex such as NKG2D. Here, we report that the CTLR Nkrp1g is expressed by a subpopulation of mouse CD103(+) IELs allowing immunosensing of the intestinal epithelium through ligation of the genetically coupled CTLR Clr-f that is almost exclusively expressed on differentiated intestinal epithelial cells (IECs). Most of these Nkrp1g-expressing IELs exhibit a γδTCR(bright)Nkg2a(-) phenotype and are intimately associated with the intestinal epithelium. As Clr-f expression strongly inhibits effector functions of Nkrp1g-expressing cells and is upregulated upon poly(I:C) challenge, Clr-f molecules may quench reactivity of these IELs towards the epithelial barrier that is constantly provoked by microbial and antigenic stimuli. Altogether, we here newly characterize a genetically linked C-type lectin-like receptor/ligand pair with a highly restricted tissue expression that apparently evolved to allow for a dedicated immunosurveillance of the mouse intestinal epithelium. PMID:24985083

  1. Characterization of a recombinant C-type lectin, rCEL-IV, expressed in Escherichia coli cells using a synthetic gene.

    PubMed

    Hatakeyama, Tomomitsu; Hozawa, Takao; Hirotani, Iyo; Tsuda, Nobuaki; Kusunoki, Masami; Shiba, Kohei

    2006-03-01

    The body fluid of marine invertebrate Cucumaria echinata (Holothuroidea) contains four Ca2+-dependent galactose-specific lectins. One of these lectins, CEL-IV, is composed of a C-type carbohydrate-recognition domain homotetramer. CEL-IV exhibits higher specificity for alpha-galactosides than for beta-galactosides, while other C. echinata lectins show preferential binding of beta-galactosides. We constructed an artificial synthetic gene for recombinant CEL-IV (rCEL-IV) based on the amino acid sequence previously determined from the purified protein. rCEL-IV was expressed in Escherichia coli cells as inclusion bodies. After the refolding process, most of rCEL-IV spontaneously formed a homotetramer structure having interchain disulfide bonds. The secondary structure of rCEL-IV was similar to that of the native one, as judged by the comparison of the far UV-circular dichroism spectra of rCEL-IV and native CEL-IV (nCEL-IV). Carbohydrate-binding specificity of rCEL-IV was confirmed to be similar to that of nCEL-IV from the results of the binding-inhibition assay using liposomes composed of rabbit erythrocyte lipids. Crystals of rCEL-IV were obtained in a few days by the sitting drop vapor diffusion method. These results indicate that rCEL-IV achieved essentially correct three-dimensional structure, including the carbohydrate-binding sites, and it would be very useful for further study on the carbohydrate-recognition mechanism by mutational and X-ray crystallographic analyses. PMID:16503091

  2. Involvement of viral envelope GP2 in Ebola virus entry into cells expressing the macrophage galactose-type C-type lectin

    SciTech Connect

    Usami, Katsuaki; Matsuno, Keita; Igarashi, Manabu; Denda-Nagai, Kaori; Takada, Ayato; Irimura, Tatsuro

    2011-04-01

    Highlights: {yields} Ebola virus infection is mediated by binding to and fusion with the target cells. {yields} Structural feature of the viral glycoprotein determines the infectivity. {yields} Surface C-type lectin, MGL, of macrophages and dendritic cells mediate the infection. {yields} GP2, one of glycoprotein subunits, plays an essential role in MGL-mediated infection. {yields} There is a critical amino acid residue involved in high infectivity. -- Abstract: Ebola virus (EBOV) infection is initiated by the interaction of the viral surface envelope glycoprotein (GP) with the binding sites on target cells. Differences in the mortality among different species of the Ebola viruses, i.e., Zaire ebolavirus (ZEBOV) and Reston ebolavirus (REBOV), correspond to the in vitro infectivity of the pseudo-typed virus constructed with the GPs in cells expressing macrophage galactose-type calcium-type lectin (MGL/CD301). Through mutagenesis of GP2, the transmembrane-anchored subunit of GP, we found that residues 502-527 of the GP2 sequence determined the different infectivity between VSV-ZEBOV GP and -REBOV GP in MGL/CD301-expressing cells and a histidine residue at position 516 of ZEBOV GP2 appeared essential in the differential infectivity. These findings may provide a clue to clarify a molecular basis of different pathogenicity among EBOV species.

  3. Amino acid sequence and carbohydrate-binding analysis of the N-acetyl-D-galactosamine-specific C-type lectin, CEL-I, from the Holothuroidea, Cucumaria echinata.

    PubMed

    Hatakeyama, Tomomitsu; Matsuo, Noriaki; Shiba, Kouhei; Nishinohara, Shoichi; Yamasaki, Nobuyuki; Sugawara, Hajime; Aoyagi, Haruhiko

    2002-01-01

    CEL-I is one of the Ca2+-dependent lectins that has been isolated from the sea cucumber, Cucumaria echinata. This protein is composed of two identical subunits held by a single disulfide bond. The complete amino acid sequence of CEL-I was determined by sequencing the peptides produced by proteolytic fragmentation of S-pyridylethylated CEL-I. A subunit of CEL-I is composed of 140 amino acid residues. Two intrachain (Cys3-Cys14 and Cys31-Cys135) and one interchain (Cys36) disulfide bonds were also identified from an analysis of the cystine-containing peptides obtained from the intact protein. The similarity between the sequence of CEL-I and that of other C-type lectins was low, while the C-terminal region, including the putative Ca2+ and carbohydrate-binding sites, was relatively well conserved. When the carbohydrate-binding activity was examined by a solid-phase microplate assay, CEL-I showed much higher affinity for N-acetyl-D-galactosamine than for other galactose-related carbohydrates. The association constant of CEL-I for p-nitrophenyl N-acetyl-beta-D-galactosaminide (NP-GalNAc) was determined to be 2.3 x 10(4) M(-1), and the maximum number of bound NP-GalNAc was estimated to be 1.6 by an equilibrium dialysis experiment. PMID:11866098

  4. Mannosylation Allows for Synergic (CD44/C-Type Lectin) Uptake of Hyaluronic Acid Nanoparticles in Dendritic Cells, but Only upon Correct Ligand Presentation.

    PubMed

    Gennari, Arianna; Pelliccia, Maria; Donno, Roberto; Kimber, Ian; Tirelli, Nicola

    2016-04-01

    The selective targeting of dendritic cells (DCs) can lead to more efficacious vaccines. Here, materials have been designed for a synergic DC targeting: interacting with CD44 through the use of hyaluronic acid (HA), and with mannose-binding lectins (typical DC pattern recognition receptors) through HA mannosylation. Negatively charged, HA-displaying nanoparticles are produced via polyelectrolyte complexation of (mannosylated) HA and high- or low- molecular-weight chitosan (CS, 36 and 656 kDa). Using CS36, HA is better exposed and the particles have a higher affinity for HA receptors; this means a higher number of receptors clustered around each particle and, due to the rather limited CD44 availability, an overall lower uptake per cell. Employing Langerhans-like XS106 cells, all particles show negligible toxicity or inflammatory activation. The cellular uptake kinetics are qualitatively similar to other leukocytic models and thus considered to be CD44-dominated; the uptake increases with increasing HA mannosylation and with the use of adjuvants (LPS, mannan) for CS36/HA but not for CS656//HA particles; this indicates that the interactions with mannose-binding receptors requires a correct ligand presentation, and only in that case can they be enhanced by appropriate adjuvants. In summary, mannose-binding receptors can be used to enhance the internalization of HA-based carriers, although this positive synergy depends on the mode of ligand presentation. PMID:26865006

  5. Characterization of recombinant CEL-I, a GalNAc-specific C-type lectin, expressed in Escherichia coli using an artificial synthetic gene.

    PubMed

    Hatakeyama, Tomomitsu; Shiba, Kouhei; Matsuo, Noriaki; Fujimoto, Tokiko; Oda, Tatsuya; Sugawara, Hajime; Aoyagi, Haruhiko

    2004-01-01

    CEL-I is a C-type lectin isolated from the Holothuroidea Cucumaria echinata. This lectin shows very high N-acetylgalactosamine-binding specificity. We constructed an artificial gene encoding recombinant CEL-I (rCEL-I) using a combination of synthetic oligonucleotides, and expressed it in Escherichia coli cells. Since the recombinant protein was obtained as inclusion bodies, the latter were solubilized using urea and 2-mercaptoethanol, and the protein was refolded during the purification and dialysis steps. The purified rCEL-I showed comparable hemagglutinating activity to that of native CEL-I at relatively high Ca(2+)-concentrations, whereas it was weaker at lower Ca(2+)-concentrations due to decreased Ca(2+)-binding affinity. rCEL-I exhibited similar carbohydrate-binding specificity to native CEL-I, including strong GalNAc-binding specificity, as examined by hemagglutination inhibition assay. Comparison of the far UV-CD spectra of recombinant and native CEL-I revealed that the two proteins undergo a similar conformational change upon binding of Ca(2+). Single crystals of rCEL-I were also obtained under the same conditions as those used for the native protein, suggesting that they have similar tertiary structures. Although native CEL-I exhibited strong cytotoxicity toward cultured cells, rCEL-I showed low cytotoxicity. These results indicate that rCEL-I has a tertiary structure and carbohydrate-binding specificity similar to those of native CEL-I. Howeger, there is a subtle difference in the properties between the two proteins probably due to the additional methionine residue at the N-terminus of rCEL-I. PMID:14999015

  6. Allergy-Protective Arabinogalactan Modulates Human Dendritic Cells via C-Type Lectins and Inhibition of NF-κB.

    PubMed

    Peters, Marcus; Guidato, Patrick M; Peters, Karin; Megger, Dominik A; Sitek, Barbara; Classen, Birgit; Heise, Esther M; Bufe, Albrecht

    2016-02-15

    Arabinogalactan (AG) isolated from dust of a traditional farm prevents disease in murine models of allergy. However, it is unclear whether this polysaccharide has immune regulatory properties in humans. The aim of this study was to test the influence of AG on the immune-stimulating properties of human dendritic cells (DCs). Moreover, we sought to identify the receptor to which AG binds. AG was produced from plant callus tissue under sterile conditions to avoid the influence of pathogen-associated molecular patterns in subsequent experiments. The influence of AG on the human immune system was investigated by analyzing its impact on monocyte-derived DCs. To analyze whether the T cell stimulatory capacity of AG-stimulated DCs is altered, an MLR with naive Th cells was performed. We revealed that AG reduced T cell proliferation in a human MLR. In the search for a molecular mechanism, we found that AG binds to the immune modulatory receptors DC-specific ICAM-3 -: grabbing non integrin (DC-SIGN) and macrophage mannose receptor 1 (MMR-1). Stimulation of these receptors with AG simultaneously with TLR4 stimulation with LPS increased the expression of the E3 ubiquitin-protein ligase tripartite motif -: containing protein 21 and decreased the phosphorylation of NF-κB p65 in DCs. This led to a reduced activation profile with reduced costimulatory molecules and proinflammatory cytokine production. Blocking of MMR-1 or DC-SIGN with neutralizing Abs partially inhibits this effect. We conclude that AG dampens the activation of human DCs by LPS via binding to DC-SIGN and MMR-1, leading to attenuated TLR signaling. This results in a reduced T cell activation capacity of DCs. PMID:26746190

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

    DOE PAGESBeta

    Yang, Yongil; Labbé, Jessy; Muchero, Wellington; Yang, Xiaohan; Jawdy, Sara S.; Kennedy, Megan; Johnson, Jenifer; Sreedasyam, Avinash; Schmutz, Jeremy; Tuskan, Gerald A.; et al

    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.

  8. Antimicrobial functions of EsLecH, a C-type lectin, via JNK pathway in the Chinese mitten crab, Eriocheir sinensis.

    PubMed

    Zhu, You-Ting; Zhang, Xing; Wang, Shi-Chuang; Li, Wei-Wei; Wang, Qun

    2016-08-01

    C-type lectins (CTLs) are pattern recognition proteins that play significant roles in the innate immune system by identifying and eliminating pathogens. Here, we have reported a CTL (EsLecH) from the Chinese mitten crab that can bind to microorganisms and regulate antimicrobial peptide (AMP) expression via the c-Jun N-terminal kinase (JNK) pathway. EsLecH was found to have an N-terminal signal peptide and a single carbohydrate recognition domain. The EsLecH transcript was detected abundantly in various tissues, and it was significantly upregulated in hemocytes after challenging with lipopolysaccharides and bacteria. Recombinant (r)EsLecH could bind to microorganisms, but at different levels. Ca(2+) significantly increased rEsLecH binding affinity to microorganisms. Furthermore, growth inhibition by rEsLecH increased with increasing rEsLecH levels. Knockdown of EsLecH was accompanied by a significant reduction in AMP expression and JNK phosphorylation; AMP expression was reduced with JNK silencing and can not rescued by rEsLecH when absence of JNK. These results indicate that EsLecH could regulate AMPs via JNK signaling. PMID:27068761

  9. C-type lectin-like molecule-1 (CLL1)-targeted TRAIL augments the tumoricidal activity of granulocytes and potentiates therapeutic antibody-dependent cell-mediated cytotoxicity

    PubMed Central

    Wiersma, Valerie R; de Bruyn, Marco; Shi, Ce; Gooden, Marloes JM; Wouters, Maartje CA; Samplonius, Douwe F; Hendriks, Djoke; Nijman, Hans W; Wei, Yunwei; Zhou, Jin; Helfrich, Wijnand; Bremer, Edwin

    2015-01-01

    The therapeutic effect of anti-cancer monoclonal antibodies stems from their capacity to opsonize targeted cancer cells with subsequent phagocytic removal, induction of antibody-dependent cell-mediated cytotoxicity (ADCC) or induction of complement-mediated cytotoxicity (CDC). The major immune effector cells involved in these processes are natural killer (NK) cells and granulocytes. The latter and most prevalent blood cell population contributes to phagocytosis, but is not effective in inducing ADCC. Here, we report that targeted delivery of the tumoricidal protein tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) to granulocyte marker C-type lectin-like molecule-1 (CLL1), using fusion protein CLL1:TRAIL, equips granulocytes with high levels of TRAIL. Upon CLL1-selective binding of this fusion protein, granulocytes acquire additional TRAIL-mediated cytotoxic activity that, importantly, potentiates antibody-mediated cytotoxicity of clinically used therapeutic antibodies (e.g., rituximab, cetuximab). Thus, CLL1:TRAIL could be used as an adjuvant to optimize the clinical potential of anticancer antibody therapy by augmenting tumoricidal activity of granulocytes. PMID:25760768

  10. A novel C-type lectin with triple carbohydrate recognition domains has critical roles for the hard tick Haemaphysalis longicornis against Gram-negative bacteria.

    PubMed

    Maeda, Hiroki; Miyata, Takeshi; Kusakisako, Kodai; Galay, Remil Linggatong; Talactac, Melbourne Rio; Umemiya-Shirafuji, Rika; Mochizuki, Masami; Fujisaki, Kozo; Tanaka, Tetsuya

    2016-04-01

    C-type lectins (CLecs) play an important role in innate immunity against invaders. In this study, a novel CLec was identified from Haemaphysalis longicornis ticks (HlCLec). HlCLec contains a signal peptide and a transmembrane region. Interestingly, HlCLec possesses three dissimilar carbohydrate recognition domains (CRDs). Each CRD contains the mutated motif of Ca(2+)-binding site 2. HlCLec mRNA was up-regulated during blood feeding, and had highest expression in the midgut and ovary. HlCLec localization was also confirmed by immunofluorescent antibody test (IFAT). HlCLec was found on the cell membrane and basal lamina of midgut and ovary. In addition, the recombinant HlCLec and individual CRDs demonstrated direct binding activity to Escherichia coli and Staphylococcus aureus; however, no growth inhibition activity was observed. Furthermore, E. coli injection after silencing of HlCLec caused drastic reduction in survival rate of ticks. These results strongly suggest the key role of HlCLec in tick innate immunity against Gram-negative bacteria. PMID:26724379

  11. CEL-I, an N-acetylgalactosamine (GalNAc)-specific C-type lectin, induces nitric oxide production in RAW264.7 mouse macrophage cell line.

    PubMed

    Yamanishi, Tomohiro; Hatakeyama, Tomomitsu; Yamaguchi, Kenichi; Oda, Tatsuya

    2009-08-01

    We found that CEL-I, a GalNAc-specific C-type lectin isolated from the marine invertebrate Holothuroidea (Cucumaria echinata), induces inducible nitric oxide synthase (iNOS) expression and NO production in RAW264.7 cells. The NO production was inhibited by an iNOS inhibitor, L-NAME, but was not by a lipopolysaccharide (LPS) inhibitor, polymyxin B. In the presence of 0.1-M GalNAc, increased NO production by CEL-I-treated RAW264.7 cells was observed rather than the inhibition. Bovine serum albumin (BSA) significantly inhibited the CEL-I-induced NO production as well as the binding of FITC-labelled CEL-I on RAW264.7 cells. Three MAP kinase inhibitors (specific to extra-cellular regulated kinase, c-jun NH(2)-terminal kinase and p38 MAP kinase) inhibited CEL-I-induced NO production with different extents. Heat-treatment of CEL-I resulted in a decreased activity of CEL-I depending on the temperature. These results suggest that CEL-I induces NO production in RAW264.7 cells through the protein-cell interaction rather than the binding to the specific carbohydrate chains on the cell surface. PMID:19351706

  12. Lectin-like Oxidized Low-Density Lipoprotein (LDL) Receptor (LOX-1): A Chameleon Receptor for Oxidized LDL.

    PubMed

    Zeya, Bushra; Arjuman, Albina; Chandra, Nimai Chand

    2016-08-16

    LOX-1, one of the main receptors for oxLDL, is found mainly on the surface of endothelial cells. It is a multifacet 52 kDa type II transmembrane protein that structurally belongs to the C-type lectin family. It exists with short intracellular N-terminal and long extracellular C-terminal hydrophilic domains separated by a hydrophobic domain of 26 amino acids. LOX-1 acts like a bifunctional receptor either showing pro-atherogenicity by activating the NFκB-mediated down signaling cascade for gene activation of pro-inflammatory molecules or playing an atheroprotective agent by receptor-mediated uptake of oxLDL in the presence of an anti-inflammatory molecule like IL-10. Mildly, moderately, and highly oxidized LDL show their characteristic features upon LOX-1 activation and its ligand binding indenture. The polymorphic LOX-1 genes are intensively associated with increased susceptibility to myocardial diseases. The splicing variant LOX IN dimerizes with the native form of LOX-1 and protects cells from damage by oxidized LDL. In the developing field of regenerating medicine, LOX-1 is a potential target for therapeutic intervention. PMID:27419271

  13. Putative glycoprotein and glycolipid polymorphonuclear leukocyte receptors for the Actinomyces naeslundii WVU45 fimbrial lectin.

    PubMed Central

    Sandberg, A L; Ruhl, S; Joralmon, R A; Brennan, M J; Sutphin, M J; Cisar, J O

    1995-01-01

    Recognition of receptors on sialidase-treated polymorphonuclear leukocytes (PMNs) by the Gal/GalNAc lectin associated with the type 2 fimbriae of certain strains of actinomyces results in activation of the PMNs, phagocytosis, and destruction of the bacteria. In the present study, plant lectins were utilized as probes to identify putative PMN receptors for the actinomyces lectin. The Gal-reactive lectin from Ricinus communis (RCAI), the Gal/GalNAc-reactive lectins from R. communis (RCAII) and Bauhinia purpurea (BPA), as well as the Gal beta 1-3GalNAc-specific lectins from Arachis hypogaea (PNA) and Agaricus bisporus (ABA) inhibited killing of Actinomyces naeslundii WVU45 by sialidase-treated PMNs. These five lectins detected a 130-kDa surface-labeled glycoprotein on nitrocellulose transfers of PMN extracts separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This glycoprotein was revealed only after treatment of the transfers with sialidase, a condition analogous to the sialidase dependence of the lectin-mediated biological responses of the PMNs to the actinomyces. The mannose-reactive lectin concanavalin A did not inhibit killing of the actinomyces and failed to detect the 130-kDa glycoprotein but did block PMN-dependent killing of Escherichia coli B, a bacterium that possesses mannose-sensitive fimbriae. Therefore, the PMN glycoprotein receptor for A. naeslundii is clearly distinct from those recognized by E. coli. Two major putative glycolipid receptors were also identified by actinomyces and RCAI overlays on sialidase-treated thin-layer chromatograms of PMN gangliosides. Thus, both a 130-kDa glycoprotein and certain gangliosides are implicated in the attachment of the actinomyces to PMNs. PMID:7790078

  14. Functional evaluation of the role of C-type lectin domain family 16A at the chromosome 16p13 locus

    PubMed Central

    Zouk, H; D'Hennezel, E; Du, X; Ounissi-Benkalha, H; Piccirillo, C A; Polychronakos, C

    2014-01-01

    The type 1 diabetes-associated 16p13 locus contains the CLEC16A gene. Its preferential immune cell expression suggests involvement in autoimmunity. Given its elevated expression in dendritic and B cells – known professional antigen-presenting cells (APCs) – we hypothesize that C-type lectin domain family 16 member A (CLEC16A) may be involved in T cell co-stimulation and consequent activation and proliferation. We also sought to identify CLEC16A's subcellular localization. The effect of the CLEC16A knock-down (KD) on B cell co-stimulation and activation of T cells was tested in human lymphoblastoid cell lines (LCLs) by co-culture with CD4+ T cells. T cell activation and proliferation were determined by flow-cytometric analysis of CD69 and CD25 expression and carboxyfluorescein succinimidyl ester (CFSE) dilution, respectively. CLEC16A subcellular localization in K562 cells was examined by immunofluorescence. We show that the CLEC16A KD did not affect the tested indices of lymphoblastoid cell line (LCL) APC capacity. Additionally, the percentage of activated T cells following LCL co-culture was not affected significantly by the CLEC16A KD. T cells co-cultured with KD or control LCLs also exhibited similar cell division profiles. CLEC16A co-localized with an endoplasmic reticulum (ER) marker, suggesting that it may be an ER protein. In conclusion, CLEC16A may not be involved in T cell co-stimulation. Additional studies on CLEC16A, accounting for its ER localization, are needed to uncover its biological role. PMID:24237155

  15. Receptor mediated targeting of lectin conjugated gliadin nanoparticles in the treatment of Helicobacter pylori.

    PubMed

    Umamaheshwari, R B; Jain, N K

    2003-08-01

    The present work describes the potential for using lectin-conjugated gliadin nanoparticles as a means of locating and anchoring a drug delivery system on the carbohydrate receptors of Helicobacter pylori (H. pylori). Gliadin nanoparticles (GNP) bearing acetohydroxamic acid (AHA) were prepared by a desolvation method. Ulex Europaeus Agglutinin I (UEA I) and Conconavalin A (Con A) lectins were bound to GNP formulations by the two-stage carbodiimide coupling technique. Lectin-agglutination assay was performed to evaluate the binding efficacy of lectin formulations to carbohydrate receptors of H. pylori strains. Strong agglutination patterns were observed with mannose-specific Con A-GNP and alpha(L)-fucose specific UEA-GNP formulations. In situ adherence assay was performed to examine the efficacy of lectin formulations to inhibit the binding of H. pylori strains with human stomach cells. Lectin formulations completely inhibited the H. pylori binding. In addition, the antimicrobial activity of the formulations was evaluated by percent growth inhibition studies (%GI) by using isolated H. pylori strain. The inhibitory efficacy of UEA-GNP and Con A-GNP was approximately two-fold higher compared to GNP. These lectin-conjugated gliadin nanoparticles are found to be potential candidate for targeted drug delivery and are anticipated to be useful in the treatment of H. pylori. PMID:15203930

  16. Functional receptors in the avian kidney for C-type natriuretic peptide.

    PubMed

    Brenner, D; Gerstberger, R

    1999-04-01

    Renal actions of avian-specific C-type natriuretic peptide (chCNP) were investigated in the conscious Pekin duck. Under conditions of steady-state renal water and salt elimination, systemic chCNP administration (6 and 30 pmol/min x kg BW for 20 min) dose dependently induced transient natriuresis and diuresis. Mean arterial pressure and heart rate remained constant throughout the experiment. Employing receptor autoradiography, binding sites specific for [125I]BH-chCNP could be localized at high density in glomeruli of both reptilian- and mammalian-type nephrons, and arterioles of the avian kidney. The distal tubular zone revealed [125I]BH-chCNP binding sites at medium, the medullary cone area at low density. Using an enriched kidney membrane fraction, competitive displacement studies with [125I]BH-chCNP as radioligand and various unlabeled peptide analogs (chANP, chCNP, rANP, rBNP, frANP, rANP(4-23)) allowed the discrimination of high-affinity (IC50 values 10(-10)-10(-9) M) and low-affinity (IC50 values 10(-8)-10(-7) M) binding sites different from typical mammalian receptor subtypes. Intracellular cyclic GMP formation could be demonstrated immunocytochemically for both types of glomeruli and cells of the distal tubular zone in fixed tissue sections after in vivo application of chCNP (0.8 nmol/min x kg BW; 5 min). The results obtained by combination of physiological in vivo studies and in vitro receptor analysis indicate an important role for chCNP in the modulation of avian kidney function. PMID:10098496

  17. Molecular characterization of the reniform nematode C-type lectin gene family reveals a likely role in mitigating environmental stresses during plant parasitism.

    PubMed

    Ganji, Satish; Jenkins, Johnie N; Wubben, Martin J

    2014-03-10

    The reniform nematode, Rotylenchulus reniformis, is a damaging semi-endoparasitic pathogen of more than 300 plant species. Transcriptome sequencing of R. reniformis parasitic females revealed an enrichment for sequences homologous to C-type lectins (CTLs), an evolutionarily ancient family of Ca(+2)-dependent carbohydrate-binding proteins that are involved in the innate immune response. To gain further insight as to the potential role of CTLs in facilitating plant parasitism by R. reniformis, we performed a comprehensive assessment of the CTL gene family. 5'- and 3'-RACE experiments identified a total of 11 R. reniformis CTL transcripts (Rr-ctl-1 through Rr-ctl-11) that ranged in length from 1083 to 1,194 bp and showed 93-99% identity with one another. An alignment of cDNA and genomic sequences revealed three introns with the first intron residing within the 5'-untranslated region. BLAST analyses showed the closest homologs belonging to the parasitic nematodes Heligmosomoides polygyrus and Heterodera glycines. Rr-ctl-1, -2, and -3 were expressed throughout the R. reniformis life cycle; whereas, the remaining Rr-ctl genes showed life stage-specific expression. Quantitative real time RT-PCR determined that Rr-ctl transcripts were 839-fold higher in sedentary female nematodes than the next most abundant life stage. Predicted Rr-CTL peptides ranged from 301 to 338 amino acids long, possessed an N-terminal signal peptide for secretion, and contained a conserved CLECT domain, including the mannose-binding motifs EPN and EPD and the conserved WND motif that is required for binding Ca(+2). In addition, Rr-CTL peptides harbored repeats of a novel 17-mer motif within their C-terminus that showed similarity to motifs associated with bacterial ice nucleation proteins. In situ hybridization of Rr-ctl transcripts within sedentary females showed specific accumulation within the hypodermis of the body regions exposed to the soil environment; those structures embedded within the

  18. Lectin-dependent attachment of Actinomyces naeslundii to receptors on epithelial cells.

    PubMed Central

    Brennan, M J; Cisar, J O; Vatter, A E; Sandberg, A L

    1984-01-01

    The adherence of Actinomyces naeslundii WVU45 to monolayer cultures of human epithelial cell lines was mediated by the lactose-sensitive fimbriae (type 2) of strain WVU45. The attachment of Actinomyces viscosus T14V, which has both types 1 and 2 fimbriae, was approximately half that of A. naeslundii, and only minimal attachment of A. naeslundii and A. viscosus mutants lacking type 2 fimbriae was detected. The adherence of strain WVU45 was enhanced two- to threefold by neuraminidase treatment of the epithelial cells. The Fab fragments of antibodies which recognize the type 2 fimbriae inhibited the adherence of A. naeslundii WVU45 to the epithelial cells. The bacterial interaction with epithelial cells was inhibited by lactose, methyl-beta-D-galactoside, and N-acetyl-D-galactosamine, but not by methyl-alpha-D-galactoside, cellobiose, N-acetyl-D-glucosamine, L-fucose, or D-mannose. To further characterize the epithelial cell receptors for the bacterial lectin, we utilized several plant and invertebrate lectins as potential inhibitors of bacterial adherence. Lectins from Bauhinia purpurea and Arachis hypogaea which recognize N-acetyl-D-galactosamine, D-galactose, and D-galactose-beta-(1----3)-N-acetyl-D-galactosamine inhibited bacterial attachment, and binding of these lectins to epithelial cells was enhanced by the addition of neuraminidase. Lectins reacting with alpha-linked D-galactose, alpha-linked N-acetyl-D-galactosamine, D-mannose, or sialic acid were not inhibitory. Under similar assay conditions, adherence of a mannose-sensitive strain of Escherichia coli was inhibited by concanavalin A but not by the lectin from Bauhinia purpurea. These results indicate that certain plant lectins have specificities similar to that of the actinomyces fimbrial lectin and are, therefore, useful probes for identifying receptors on epithelial cells for certain bacteria. Images PMID:6150008

  19. Lectin-Glycan Interaction Network-Based Identification of Host Receptors of Microbial Pathogenic Adhesins

    PubMed Central

    Ielasi, Francesco S.; Alioscha-Perez, Mitchel; Donohue, Dagmara; Claes, Sandra; Sahli, Hichem; Schols, Dominique

    2016-01-01

    ABSTRACT The first step in the infection of humans by microbial pathogens is their adherence to host tissue cells, which is frequently based on the binding of carbohydrate-binding proteins (lectin-like adhesins) to human cell receptors that expose glycans. In only a few cases have the human receptors of pathogenic adhesins been described. A novel strategy—based on the construction of a lectin-glycan interaction (LGI) network—to identify the potential human binding receptors for pathogenic adhesins with lectin activity was developed. The new approach is based on linking glycan array screening results of these adhesins to a human glycoprotein database via the construction of an LGI network. This strategy was used to detect human receptors for virulent Escherichia coli (FimH adhesin), and the fungal pathogens Candida albicans (Als1p and Als3p adhesins) and C. glabrata (Epa1, Epa6, and Epa7 adhesins), which cause candidiasis. This LGI network strategy allows the profiling of potential adhesin binding receptors in the host with prioritization, based on experimental binding data, of the most relevant interactions. New potential targets for the selected adhesins were predicted and experimentally confirmed. This methodology was also used to predict lectin interactions with envelope glycoproteins of human-pathogenic viruses. It was shown that this strategy was successful in revealing that the FimH adhesin has anti-HIV activity. PMID:27406561

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

    PubMed

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

    2015-01-01

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

  1. The lipopolysaccharide-binding protein participating in hemocyte nodule formation in the silkworm Bombyx mori is a novel member of the C-type lectin superfamily with two different tandem carbohydrate-recognition domains.

    PubMed

    Koizumi, N; Imamura, M; Kadotani, T; Yaoi, K; Iwahana, H; Sato, R

    1999-01-25

    We recently isolated and characterized the lipopolysaccharide (LPS)-binding protein, BmLBP, from the larval hemolymph of the silkworm Bombyx mori. BmLBP is a pattern recognition molecule that recognizes the lipid A portion of LPS and participates in a cellular defense reaction. This paper describes the cDNA cloning of BmLBP. The deduced amino acid sequence of BmLBP revealed that BmLBP is a novel member of the C-type lectin superfamily with a unique structural feature that consists of two different carbohydrate-recognition domains in tandem, a short and a long form. PMID:9989592

  2. A New C-Type Lectin Similar to the Human Immunoreceptor DC-SIGN Mediates Symbiont Acquisition by a Marine Nematode†

    PubMed Central

    Bulgheresi, Silvia; Schabussova, Irma; Chen, Tie; Mullin, Nicholas P.; Maizels, Rick M.; Ott, Jörg A.

    2006-01-01

    Although thiotrophic symbioses have been intensively studied for the last three decades, nothing is known about the molecular mechanisms of symbiont acquisition. We used the symbiosis between the marine nematode Laxus oneistus and sulfur-oxidizing bacteria to study this process. In this association a monolayer of symbionts covers the whole cuticle of the nematode, except its anterior-most region. Here, we identify a novel Ca2+-dependent mannose-specific lectin that was exclusively secreted onto the posterior, bacterium-associated region of L. oneistus cuticle. A recombinant form of this lectin induced symbiont aggregation in seawater and was able to compete with the native lectin for symbiont binding in vivo. Surprisingly, the carbohydrate recognition domain of this mannose-binding protein was similar both structurally and functionally to a human dendritic cell-specific immunoreceptor. Our results provide a molecular link between bacterial symbionts and host-secreted mucus in a marine symbiosis and suggest conservation in the mechanisms of host-microbe interactions throughout the animal kingdom. PMID:16598002

  3. Isolation of human beta-interferon receptor by wheat germ lectin affinity and immunosorbent column chromatographies

    SciTech Connect

    Zhang, Z.Q.; Fournier, A.; Tan, Y.H.

    1986-06-15

    Radioiodinated human beta-interferon-Ser 17 (Betaseron) was reversibly cross-linked to Daudi cells by dithiobis(succinimidylpropionate). The radioactive ligand was cross-linked to three macromolecules forming labeled complexes of apparent Mr values of 130,000, 220,000, and 320,000. Betaseron, human alpha-interferon, human interleukin 2 but not recombinant human gamma-interferon competed with the labeled ligand for binding to these putative receptor(s). Human leukocyte-produced gamma-interferon competed weakly with /sup 125/I-Betaseron for binding to Daudi cells. The Betaseron-receptor complex(es) was purified by passage through a wheat germ lectin column followed by chromatography on an anti-interferon immunosorbent column and semipreparative gel electrophoresis. The cross-linked ligand-receptor complex was shown to be highly purified by sodium dodecyl sulfate and acetic acid:urea:Triton X-100 polyacrylamide gel electrophoresis. It can be dissociated into the labeled Betaseron (Mr = 17,000) ligand and a receptor moiety which has an apparent molecular weight of 110,000. The chromatographic behavior of the ligand-receptor complex on wheat germ lectin column suggests that the receptor is a glycoprotein. The described procedure yielded about 1 microgram of Betaseron receptor from 10(10) Daudi cells, estimated to contain a maximum of about 15 micrograms of the receptor.

  4. Molecular Characterization and Global Expression Analysis of Lectin Receptor Kinases in Bread Wheat (Triticum aestivum)

    PubMed Central

    Pandey, Ajay K.; Singh, Kashmir; Upadhyay, Santosh Kumar

    2016-01-01

    Lectin receptor kinases (LRKs) play a critical role in plants during development and stress conditions, but a comprehensive analysis at genome level is still not carried out in Triticum aestivum. Herein, we performed the genome wide identification, characterization and expression analysis of these genes in T. aestivum (TaLRK). In-total 263 TaLRK genes were identified, which were further classified into three groups based on the nature of lectin domain. We identified, two TaLRKs consisted of calcium-dependent lectin (C-LRK), while 84 legume-lectin (L-LRK) and 177 bulb-lectin (B-LRK) domains. The L-LRK and B-LRK genes were distributed throughout the genome of T. aestivum. Most of the TaLRKs were clustered as homologs, which were distributed either in proximity on same chromosome or on homoeologous chromosomes of A, B and D sub-genomes. A total of 9 and 58 duplication events were also predicted in L-LRK and B-LRK, respectively. Phylogenetic analysis indicated conserved evolutionary relationship of homologous and orthologous genes from multiple plant species. Gene ontology analysis indicated TaLRKs role in binding, signaling and receptor activities. Most of the TaLRKs consisted of a trans-membrane domain and predicted to be localized in the plasma-membrane. A diverse expression pattern of TaLRK genes was found in various developmental stages and stress conditions. Some TaLRKs were found to be highly affected during a particular stress, which indicated a specialized role of each LRK gene in a specific stress condition. These results described various characteristic feature and expression pattern of TaLRK genes, which will pave the way for functional characterization in wheat. PMID:27111449

  5. Isolation of the receptor for Amaranthus leucocarpus lectin from murine naive thymocytes.

    PubMed

    Porras, F; Lascurain, R; Chávez, R; Ortiz, B; Hernández, P; Debray, H; Zenteno, E

    2000-05-01

    From murine medullary thymocytes we purified the receptor for the Amaranthus leucocarpus lectin (ALL) using a complex with the biotin-labeled lectin and avidin-agarose as the affinity matrix. Most ALL(+)thymocytes (83%) are naive cells with the CD4(+)CD8(-)CD45RB(+)phenotype. The receptor for this lectin is a 70 kDa glycoprotein that contains 20% of sugar by mass. It is constituted mainly by aspartic and glutamic acids, serine, proline, and glycine; its glycosidic portion contains mainly O-glycosidically linked glycans with Gal, GalNAc and NeuAc residues as well as one N-glycosidically linked glycan per molecule. Ionic strength chromatography revealed that the ALL-thymocyte receptor (ALLTr) is made up by three isoforms, which possess similar amino acid composition but show slight differences in their sugar composition. The N-terminal amino acid residues are blocked both in the receptor and its purified isoforms. Analyses of the receptor's peptides, obtained by trypsin digestion with MALDI-TOF (matrix assisted laser desorption ionization-time of flight), were compared with the relative values obtained from the NCBInr (Swiss-Prot 10/01/99) database. Our results indicate that the peptides of ALLTr show low homology (<17%) with the human KIIA protein, the Fas-associated death domain protein, and the transforming growth factor-beta type II receptor. Our results suggest that the ALL thymocyte receptor could be considered a novel phenotypic marker specific for naive T cells. PMID:10764834

  6. Plant lectin can target receptors containing sialic acid, exemplified by podoplanin, to inhibit transformed cell growth and migration.

    PubMed

    Ochoa-Alvarez, Jhon Alberto; Krishnan, Harini; Shen, Yongquan; Acharya, Nimish K; Han, Min; McNulty, Dean E; Hasegawa, Hitoki; Hyodo, Toshinori; Senga, Takeshi; Geng, Jian-Guo; Kosciuk, Mary; Shin, Seung S; Goydos, James S; Temiakov, Dmitry; Nagele, Robert G; Goldberg, Gary S

    2012-01-01

    Cancer is a leading cause of death of men and women worldwide. Tumor cell motility contributes to metastatic invasion that causes the vast majority of cancer deaths. Extracellular receptors modified by α2,3-sialic acids that promote this motility can serve as ideal chemotherapeutic targets. For example, the extracellular domain of the mucin receptor podoplanin (PDPN) is highly O-glycosylated with α2,3-sialic acid linked to galactose. PDPN is activated by endogenous ligands to induce tumor cell motility and metastasis. Dietary lectins that target proteins containing α2,3-sialic acid inhibit tumor cell growth. However, anti-cancer lectins that have been examined thus far target receptors that have not been identified. We report here that a lectin from the seeds of Maackia amurensis (MASL) with affinity for O-linked carbohydrate chains containing sialic acid targets PDPN to inhibit transformed cell growth and motility at nanomolar concentrations. Interestingly, the biological activity of this lectin survives gastrointestinal proteolysis and enters the cardiovascular system to inhibit melanoma cell growth, migration, and tumorigenesis. These studies demonstrate how lectins may be used to help develop dietary agents that target specific receptors to combat malignant cell growth. PMID:22844530

  7. Plant Lectin Can Target Receptors Containing Sialic Acid, Exemplified by Podoplanin, to Inhibit Transformed Cell Growth and Migration

    PubMed Central

    Shen, Yongquan; Acharya, Nimish K.; Han, Min; McNulty, Dean E.; Hasegawa, Hitoki; Hyodo, Toshinori; Senga, Takeshi; Geng, Jian-Guo; Kosciuk, Mary; Shin, Seung S.; Goydos, James S.; Temiakov, Dmitry; Nagele, Robert G.; Goldberg, Gary S.

    2012-01-01

    Cancer is a leading cause of death of men and women worldwide. Tumor cell motility contributes to metastatic invasion that causes the vast majority of cancer deaths. Extracellular receptors modified by α2,3-sialic acids that promote this motility can serve as ideal chemotherapeutic targets. For example, the extracellular domain of the mucin receptor podoplanin (PDPN) is highly O-glycosylated with α2,3-sialic acid linked to galactose. PDPN is activated by endogenous ligands to induce tumor cell motility and metastasis. Dietary lectins that target proteins containing α2,3-sialic acid inhibit tumor cell growth. However, anti-cancer lectins that have been examined thus far target receptors that have not been identified. We report here that a lectin from the seeds of Maackia amurensis (MASL) with affinity for O-linked carbohydrate chains containing sialic acid targets PDPN to inhibit transformed cell growth and motility at nanomolar concentrations. Interestingly, the biological activity of this lectin survives gastrointestinal proteolysis and enters the cardiovascular system to inhibit melanoma cell growth, migration, and tumorigenesis. These studies demonstrate how lectins may be used to help develop dietary agents that target specific receptors to combat malignant cell growth. PMID:22844530

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

    PubMed

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

    2016-09-01

    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

  9. Natriuretic peptide receptor-B (guanylyl cyclase-B) mediates C-type natriuretic peptide relaxation of precontracted rat aorta.

    PubMed

    Drewett, J G; Fendly, B M; Garbers, D L; Lowe, D G

    1995-03-01

    The most potent known agonist for the natriuretic peptide receptor-B (NPR-B)/guanylyl cyclase-B is C-type natriuretic peptide (CNP). A homologous ligand-receptor system consists of atrial natriuretic peptide (ANP) and NPR-A/guanylyl cyclase-A. A third member of this family is NPR-C, a non-guanylyl cyclase receptor. Monoclonal antibodies were raised against NPR-B by immunizing mice with a purified receptor-IgG fusion protein consisting of the extracellular domain of NPR-B and the Fc portion of human IgG-gamma 1. One monoclonal antibody, 3G12, did not recognize NPR-A or NPR-C and bound to human and rat NPR-B. CNP binding to NPR-B and stimulation of cGMP synthesis were inhibited by 3G12. With cells isolated from either the media or adventitia layers of rat thoracic aorta, 3G12 did not interfere with ANP-stimulated cGMP synthesis, but it inhibited CNP-stimulated cGMP levels in cells from both layers. CNP (IC50 = 10 nM) and ANP (IC50 = 1 nM) caused relaxation of phenylephrine-contracted rat aortic rings. 3G12 caused a marked increase in the IC50 for CNP, from 10 nM to 140 nM, but failed to affect ANP-mediated relaxation. Therefore, our results for the first time demonstrate that CNP relaxes vascular smooth muscle by virtue of its binding to NPR-B. PMID:7876238

  10. RTB Lectin: a novel receptor-independent delivery system for lysosomal enzyme replacement therapies

    PubMed Central

    Acosta, Walter; Ayala, Jorge; Dolan, Maureen C.; Cramer, Carole L.

    2015-01-01

    Enzyme replacement therapies have revolutionized patient treatment for multiple rare lysosomal storage diseases but show limited effectiveness for addressing pathologies in “hard-to-treat” organs and tissues including brain and bone. Here we investigate the plant lectin RTB as a novel carrier for human lysosomal enzymes. RTB enters mammalian cells by multiple mechanisms including both adsorptive-mediated and receptor-mediated endocytosis, and thus provides access to a broader array of organs and cells. Fusion proteins comprised of RTB and human α-L-iduronidase, the corrective enzyme for Mucopolysaccharidosis type I, were produced using a tobacco-based expression system. Fusion products retained both lectin selectivity and enzyme activity, were efficiently endocytosed into human fibroblasts, and corrected the disease phenotype of mucopolysaccharidosis patient fibroblasts in vitro. RTB-mediated delivery was independent of high-mannose and mannose-6-phosphate receptors, which are exploited for delivery of currently approved lysosomal enzyme therapeutics. Thus, the RTB carrier may support distinct in vivo pharmacodynamics with potential to address hard-to-treat tissues. PMID:26382970

  11. A lectin S-domain receptor kinase mediates lipopolysaccharide sensing in Arabidopsis thaliana.

    PubMed

    Ranf, Stefanie; Gisch, Nicolas; Schäffer, Milena; Illig, Tina; Westphal, Lore; Knirel, Yuriy A; Sánchez-Carballo, Patricia M; Zähringer, Ulrich; Hückelhoven, Ralph; Lee, Justin; Scheel, Dierk

    2015-04-01

    The sensing of microbe-associated molecular patterns (MAMPs) triggers innate immunity in animals and plants. Lipopolysaccharide (LPS) from Gram-negative bacteria is a potent MAMP for mammals, with the lipid A moiety activating proinflammatory responses via Toll-like receptor 4 (TLR4). Here we found that the plant Arabidopsis thaliana specifically sensed LPS of Pseudomonas and Xanthomonas. We isolated LPS-insensitive mutants defective in the bulb-type lectin S-domain-1 receptor-like kinase LORE (SD1-29), which were hypersusceptible to infection with Pseudomonas syringae. Targeted chemical degradation of LPS from Pseudomonas species suggested that LORE detected mainly the lipid A moiety of LPS. LORE conferred sensitivity to LPS onto tobacco after transient expression, which demonstrated a key function in LPS sensing and indicated the possibility of engineering resistance to bacteria in crop species. PMID:25729922

  12. An African swine fever virus ORF with similarity to C-type lectins is non-essential for growth in swine macrophages in vitro and for virus virulence in domestic swine.

    PubMed

    Neilan, J G; Borca, M V; Lu, Z; Kutish, G F; Kleiboeker, S B; Carrillo, C; Zsak, L; Rock, D L

    1999-10-01

    An African swine fever virus (ASFV) ORF, 8CR, with similarity to the C-type lectin family of adhesion proteins has been described in the pathogenic isolate Malawi Lil-20/1. The similarity of 8CR to cellular and poxvirus genes associated with cell adhesion, cell recognition and virus infectivity suggested that 8CR may be of significance to ASFV-host cell interactions. Sequence analysis of the 8CR ORF from additional pathogenic ASFV isolates demonstrated conservation among isolates from both pig and tick sources. Northern blot analysis demonstrated 8CR mRNA transcription late in the virus replication cycle. A Malawi Lil-20/1 8CR deletion mutant (delta8CR) was constructed to analyse 8CR function further. The growth characteristics in vitro of delta8CR in porcine macrophage cell cultures were identical to those observed for parental virus. In domestic swine, delta8CR exhibited an unaltered parental Malawi Lil-20/1 disease and virulence phenotype. Thus, although well conserved among pathogenic ASFV field isolates, 8CR is non-essential for growth in porcine macrophages in vitro and for virus virulence in domestic swine. PMID:10573162

  13. A new C-type lectin (RVsnaclec) purified from venom of Daboia russelii russelii shows anticoagulant activity via inhibition of FXa and concentration-dependent differential response to platelets in a Ca²⁺-independent manner.

    PubMed

    Mukherjee, Ashis K; Dutta, Sumita; Mackessy, Stephen P

    2014-11-01

    This is the first report on the characterization of a snaclec (RVsnaclec) purified from Daboia russelii russelii venom. The RVsnaclec is a heterodimer of two subunits, α (15.1 kDa) and β (9 kDa). These subunits are covalently linked to form multimeric (αβ)₂ and (αβ)₄ structures. Peptide mass fingerprinting analysis of RVsnaclec via LC-MS/MS demonstrated its similarity to snaclecs purified from other viperid snake venoms. Two tryptic peptide sequences of RVsnaclec revealed the putative conserved domains of C-type lectin (CTL). RVsnaclec dose-dependently increased the Ca-clotting time and prothrombin time of platelet-poor plasma (PPP); however, it did not affect the partial thromboplastin time (APTT) or thrombin time of PPP. The in vitro and in vivo anticoagulant activity of RVsnaclec is correlated to its binding and subsequent uncompetitive inhibition of FXa (Ki = 0.52 μmole) in a Ca(2+)-independent manner; however, supplementation with 0.25 mM Ca(2+) enhanced the Xa binding potency of RVsnaclec. Monovalent or polyvalent antivenom failed to neutralize its anticoagulant potency, and RVsnaclec did not inhibit trypsin, chymotrypsin, thrombin or plasmin. RVsnaclec was devoid of hemolytic activity or cytotoxicity against several human cancer cell lines, demonstrated concentration-dependent aggregation and deaggregation of human platelets, and inhibited the ADP-induced aggregation of platelet. RVsnaclec (5.0 mg/kg body weight) was non-lethal to mice and showed no adverse pharmacological effects, suggesting that it has potential as a lead compound for future therapeutic applications in cardiovascular disorders. PMID:25281435

  14. Assembly, organization and regulation of cell-surface receptors by lectin-glycan complexes.

    PubMed

    Elola, María T; Blidner, Ada G; Ferragut, Fátima; Bracalente, Candelaria; Rabinovich, Gabriel A

    2015-07-01

    Galectins are a family of β-galactoside-binding lectins carrying at least one consensus sequence in the carbohydrate-recognition domain. Properties of glycosylated ligands, such as N- and O-glycan branching, LacNAc (N-acetyl-lactosamine) content and the balance of α2,3- and α2,6-linked sialic acid dramatically influence galectin binding to a preferential set of counter-receptors. The presentation of specific glycans in galectin-binding partners is also critical, as proper orientation and clustering of oligosaccharide ligands on multiple carbohydrate side chains increase the binding avidity of galectins for particular glycosylated receptors. When galectins are released from the cells, they typically concentrate on the cell surface and the local matrix, raising their local concentration. Thus galectins can form their own multimers in the extracellular milieu, which in turn cross-link glycoconjugates on the cell surface generating galectin-glycan complexes that modulate intracellular signalling pathways, thus regulating cellular processes such as apoptosis, proliferation, migration and angiogenesis. Subtle changes in receptor expression, rates of protein synthesis, activities of Golgi enzymes, metabolite concentrations supporting glycan biosynthesis, density of glycans, strength of protein-protein interactions at the plasma membrane and stoichiometry may modify galectin-glycan complexes. Although galectins are key contributors to the formation of these extended glycan complexes leading to promotion of receptor segregation/clustering, and inhibition of receptor internalization by surface retention, when these complexes are disrupted, some galectins, particularly galectin-3 and -4, showed the ability to drive clathrin-independent mechanisms of endocytosis. In the present review, we summarize the data available on the assembly, hierarchical organization and regulation of conspicuous galectin-glycan complexes, and their implications in health and disease. PMID:26173257

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

    SciTech Connect

    Eto, Hideyuki; Miyata, Masaaki . E-mail: miyatam@m3.kufm.kagoshima-u.ac.jp; 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 {mu}g/mL) 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.

  16. CEL-I, an invertebrate N-acetylgalactosamine-specific C-type lectin, induces TNF-alpha and G-CSF production by mouse macrophage cell line RAW264.7 cells.

    PubMed

    Yamanishi, Tomohiro; Yamamoto, Yoshiko; Hatakeyama, Tomomitsu; Yamaguchi, Kenichi; Oda, Tatsuya

    2007-11-01

    Our previous studies demonstrated that CEL-I, an N-acetylgalactosamine (GalNAc)-specific C-type lectin purified from the marine invertebrate Cucumaria echinata (Holothuroidea) showed potent cytotoxicity to several cell lines such as HeLa, MDCK and XC cells. In this study, we found that CEL-I induced increased secretion of tumour necrosis factor-alpha (TNF-alpha) and granulocyte colony stimulation factor (G-CSF) by mouse macrophage cell line RAW264.7 cells in a dose-dependent manner, whereas this cell line was highly resistant to CEL-I cytotoxicity. The cytokine-inducing activity of CEL-I was stronger than that of phytohaemagglutinin (PHA-L). A binding study using FITC-labelled CEL-I (F-CEL-I) indicated that the amount of bound F-CEL-I on RAW264.7 cells was greater than that of F-PHA-L, suggesting that the greater activity of CEL-I to induce cytokine secretion by RAW264.7 cells is partly due to the higher binding ability. Since the cell binding and cytokine-inducing activity of CEL-I were partly but significantly inhibited by the specific sugar (GalNAc), it is considered that the binding of CEL-I to cell-surface-specific saccharide moieties, which may be recognized by CEL-I with higher affinity than GalNAc, is essential for the induction of cytokine secretion. The secretion of TNF-alpha and G-CSF from CEL-I-treated RAW264.7 cells were almost completely prevented by brefeldin A (BFA), whereas increase in mRNA levels of these cytokines were not affected by BFA. Bio-Plex beads assay suggested that temporal increase in phosphorylation of extracellular-regulated kinase (ERK), c-jun NH(2)-terminal kinase (JNK) and p38 MAP kinase occurred at relatively early time following CEL-I treatment. Furthermore, the secretion of TNF-alpha and G-CSF were inhibited by specific inhibitors for these MAP kinases. These results suggest that the intracellular signal transduction through the activation of MAP kinase system is involved in CEL-I-induced cytokine secretion. PMID:17846063

  17. The lectin-like oxidized LDL receptor-1: a new potential molecular target in colorectal cancer.

    PubMed

    Murdocca, Michela; Mango, Ruggiero; Pucci, Sabina; Biocca, Silvia; Testa, Barbara; Capuano, Rosamaria; Paolesse, Roberto; Sanchez, Massimo; Orlandi, Augusto; di Natale, Corrado; Novelli, Giuseppe; Sangiuolo, Federica

    2016-03-22

    The identification of new biomarkers and targets for tailored therapy in human colorectal cancer (CRC) onset and progression is an interesting challenge. CRC tissue produces an excess of ox-LDL, suggesting a close correlation between lipid dysfunction and malignant transformation. Lectin-like oxidized LDL receptor-1 (LOX-1) is involved in several mechanisms closely linked to tumorigenesis. Here we report a tumor specific LOX-1 overexpression in human colon cancers: LOX-1 results strongly increased in the 72% of carcinomas (P<0.001), and strongly overexpressed in 90% of highly aggressive and metastatic tumours (P<0.001), as compared to normal mucosa. Moreover LOX-1 results modulated since the early stage of the disease (adenomas vs normal mucosa; P<0.001) suggesting an involvement in tumor insurgence and progression. The in vitro knockdown of LOX-1 in DLD-1 and HCT-8 colon cancer cells by siRNA and anti-LOX-1 antibody triggers to an impaired proliferation rate and affects the maintenance of cell growth and tumorigenicity. The wound-healing assay reveals an evident impairment in closing the scratch. Lastly knockdown of LOX-1 delineates a specific pattern of volatile compounds characterized by the presence of a butyrate derivative, suggesting a potential role of LOX-1 in tumor-specific epigenetic regulation in neoplastic cells. The role of LOX-1 as a novel biomarker and molecular target represents a concrete opportunity to improve current therapeutic strategies for CRC. In addition, the innovative application of a technology focused to the identification of LOX-1 driven volatiles specific to colorectal cancer provides a promising diagnostic tool for CRC screening and for monitoring the response to therapy. PMID:26895376

  18. The lectin-like oxidized LDL receptor-1: a new potential molecular target in colorectal cancer

    PubMed Central

    Murdocca, Michela; Mango, Ruggiero; Pucci, Sabina; Biocca, Silvia; Testa, Barbara; Capuano, Rosamaria; Paolesse, Roberto; Sanchez, Massimo; Orlandi, Augusto; di Natale, Corrado; Novelli, Giuseppe; Sangiuolo, Federica

    2016-01-01

    The identification of new biomarkers and targets for tailored therapy in human colorectal cancer (CRC) onset and progression is an interesting challenge. CRC tissue produces an excess of ox-LDL, suggesting a close correlation between lipid dysfunction and malignant transformation. Lectin-like oxidized LDL receptor-1 (LOX-1) is involved in several mechanisms closely linked to tumorigenesis. Here we report a tumor specific LOX-1 overexpression in human colon cancers: LOX-1 results strongly increased in the 72% of carcinomas (P<0.001), and strongly overexpressed in 90% of highly aggressive and metastatic tumours (P<0.001), as compared to normal mucosa. Moreover LOX-1 results modulated since the early stage of the disease (adenomas vs normal mucosa; P<0.001) suggesting an involvement in tumor insurgence and progression. The in vitro knockdown of LOX-1 in DLD-1 and HCT-8 colon cancer cells by siRNA and anti-LOX-1 antibody triggers to an impaired proliferation rate and affects the maintenance of cell growth and tumorigenicity. The wound-healing assay reveals an evident impairment in closing the scratch. Lastly knockdown of LOX-1 delineates a specific pattern of volatile compounds characterized by the presence of a butyrate derivative, suggesting a potential role of LOX-1 in tumor-specific epigenetic regulation in neoplastic cells. The role of LOX-1 as a novel biomarker and molecular target represents a concrete opportunity to improve current therapeutic strategies for CRC. In addition, the innovative application of a technology focused to the identification of LOX-1 driven volatiles specific to colorectal cancer provides a promising diagnostic tool for CRC screening and for monitoring the response to therapy. PMID:26895376

  19. Lectin Receptor Kinases Participate in Protein-Protein Interactions to Mediate Plasma Membrane-Cell Wall Adhesions in Arabidopsis1

    PubMed Central

    Gouget, Anne; Senchou, Virginie; Govers, Francine; Sanson, Arnaud; Barre, Annick; Rougé, Pierre; Pont-Lezica, Rafael; Canut, Hervé

    2006-01-01

    Interactions between plant cell walls and plasma membranes are essential for cells to function properly, but the molecules that mediate the structural continuity between wall and membrane are unknown. Some of these interactions, which are visualized upon tissue plasmolysis in Arabidopsis (Arabidopsis thaliana), are disrupted by the RGD (arginine-glycine-aspartic acid) tripeptide sequence, a characteristic cell adhesion motif in mammals. In planta induced-O (IPI-O) is an RGD-containing protein from the plant pathogen Phytophthora infestans that can disrupt cell wall-plasma membrane adhesions through its RGD motif. To identify peptide sequences that specifically bind the RGD motif of the IPI-O protein and potentially play a role in receptor recognition, we screened a heptamer peptide library displayed in a filamentous phage and selected two peptides acting as inhibitors of the plasma membrane RGD-binding activity of Arabidopsis. Moreover, the two peptides also disrupted cell wall-plasma membrane adhesions. Sequence comparison of the RGD-binding peptides with the Arabidopsis proteome revealed 12 proteins containing amino acid sequences in their extracellular domains common with the two RGD-binding peptides. Eight belong to the receptor-like kinase family, four of which have a lectin-like extracellular domain. The lectin domain of one of these, At5g60300, recognized the RGD motif both in peptides and proteins. These results imply that lectin receptor kinases are involved in protein-protein interactions with RGD-containing proteins as potential ligands, and play a structural and signaling role at the plant cell surfaces. PMID:16361528

  20. 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. PMID:26491100

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

    SciTech Connect

    Lee, Ha Young; Kim, Sang Doo; Baek, Suk-Hwan; Choi, Joon Hyuk; Cho, Kyung-Hyun; Zabel, Brian A.; Bae, Yoe-Sik

    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 foam 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.

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

    SciTech Connect

    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 of 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.

  3. Structure-Function Analyses of a Staphylococcus epidermidis Autoinducing Peptide Reveals Motifs Critical for AgrC-type Receptor Modulation.

    PubMed

    Yang, Tian; Tal-Gan, Yftah; Paharik, Alexandra E; Horswill, Alexander R; Blackwell, Helen E

    2016-07-15

    Staphylococcus epidermidis is frequently implicated in human infections associated with indwelling medical devices due to its ubiquity in the skin flora and formation of robust biofilms. The accessory gene regulator (agr) quorum sensing (QS) system plays a prominent role in the establishment of biofilms and infection by this bacterium. Agr activation is mediated by the binding of a peptide signal (or autoinducing peptide, AIP) to its cognate AgrC receptor. Many questions remain about the role of QS in S. epidermidis infections, as well as in mixed-microbial populations on a host, and chemical modulators of its agr system could provide novel insights into this signaling network. The AIP ligand provides an initial scaffold for the development of such probes; however, the structure-activity relationships (SARs) for activation of S. epidermidis AgrC receptors by AIPs are largely unknown. Herein, we report the first SAR analyses of an S. epidermidis AIP by performing systematic alanine and d-amino acid scans of the S. epidermidis AIP-I. On the basis of these results, we designed and identified potent, pan-group inhibitors of the AgrC receptors in the three S. epidermidis agr groups, as well as a set of AIP-I analogs capable of selective AgrC inhibition in either specific S. epidermidis agr groups or in another common staphylococcal species, S. aureus. In addition, we uncovered a non-native peptide agonist of AgrC-I that can strongly inhibit S. epidermidis biofilm growth. Together, these synthetic analogs represent new and readily accessible probes for investigating the roles of QS in S. epidermidis colonization and infections. PMID:27159024

  4. Neutral endopeptidase-resistant C-type natriuretic peptide variant represents a new therapeutic approach for treatment of fibroblast growth factor receptor 3-related dwarfism.

    PubMed

    Wendt, Daniel J; Dvorak-Ewell, Melita; Bullens, Sherry; Lorget, Florence; Bell, Sean M; Peng, Jeff; Castillo, Sianna; Aoyagi-Scharber, Mika; O'Neill, Charles A; Krejci, Pavel; Wilcox, William R; Rimoin, David L; Bunting, Stuart

    2015-04-01

    Achondroplasia (ACH), the most common form of human dwarfism, is caused by an activating autosomal dominant mutation in the fibroblast growth factor receptor-3 gene. Genetic overexpression of C-type natriuretic peptide (CNP), a positive regulator of endochondral bone growth, prevents dwarfism in mouse models of ACH. However, administration of exogenous CNP is compromised by its rapid clearance in vivo through receptor-mediated and proteolytic pathways. Using in vitro approaches, we developed modified variants of human CNP, resistant to proteolytic degradation by neutral endopeptidase, that retain the ability to stimulate signaling downstream of the CNP receptor, natriuretic peptide receptor B. The variants tested in vivo demonstrated significantly longer serum half-lives than native CNP. Subcutaneous administration of one of these CNP variants (BMN 111) resulted in correction of the dwarfism phenotype in a mouse model of ACH and overgrowth of the axial and appendicular skeletons in wild-type mice without observable changes in trabecular and cortical bone architecture. Moreover, significant growth plate widening that translated into accelerated bone growth, at hemodynamically tolerable doses, was observed in juvenile cynomolgus monkeys that had received daily subcutaneous administrations of BMN 111. BMN 111 was well tolerated and represents a promising new approach for treatment of patients with ACH. PMID:25650377

  5. L-type lectin receptor kinases in Nicotiana benthamiana and tomato and their role in Phytophthora resistance

    PubMed Central

    Wang, Yan; Weide, Rob; Govers, Francine; Bouwmeester, Klaas

    2015-01-01

    Membrane-bound receptors play crucial roles as sentinels of plant immunity against a large variety of invading microbes. One class of receptors known to be involved in self/non-self-surveillance and plant resistance comprises the L-type lectin receptor kinases (LecRKs). Previously, we reported that several Arabidopsis LecRKs play a role in resistance to Phytophthora pathogens. In this study, we determined whether homologues of these LecRKs from the Solanaceous plants Nicotiana benthamiana and tomato (Solanum lycopersicum) play similar roles in defence against Phytophthora. In genome-wide screenings, a total of 38 (Nb)LecRKs were identified in N. benthamiana and 22 (Sl)LecRKs in tomato, each consisting of both a lectin and a kinase domain. Phylogenetic analysis revealed that, in contrast to Arabidopsis, which has a LecRK family comprising nine clades, Solanaceous species have just five of these nine clades (i.e. IV, VI, VII, VIII, and IX), plus four additional clades that lack Arabidopsis homologues. Several of the Solanaceous LecRKs were selected for functional analysis using virus-induced gene silencing. Infection assays with Phytophthora capsici and Phytophthora infestans on LecRK-silenced plants revealed that N. benthamiana and tomato homologues in clade IX play a role in Phytophthora resistance similar to the two Arabidopsis LecRKs in this clade, suggesting conserved functions of clade IX LecRKs across different plant families. This study provides a first insight into the diversity of Solanaceous LecRKs and their role in plant immunity, and shows the potential of LecRKs for Phytophthora resistance breeding. PMID:26248665

  6. GMP-140 binds to a glycoprotein receptor on human neutrophils: Evidence for a lectin-like interaction

    SciTech Connect

    Moore, K.L.; Varki, A.; McEver, R.P. )

    1991-02-01

    GMP-140 is a rapidly inducible receptor for neutrophils and monocytes expressed on activated platelets and endothelial cells. It is a member of the selectin family of lectin-like cell surface molecules that mediate leukocyte adhesion. We used a radioligand binding assay to characterize the interaction of purified GMP-140 with human neutrophils. Unstimulated neutrophils rapidly bound (125I)GMP-140 at 4 degrees C, reaching equilibrium in 10-15 min. Binding was Ca2+ dependent, reversible, and saturable at 3-6 nM free GMP-140 with half-maximal binding at approximately 1.5 nM. Receptor density and apparent affinity were not altered when neutrophils were stimulated with 4 beta-phorbol 12-myristate 13-acetate. Treatment of neutrophils with proteases abolished specific binding of (125I)GMP-140. Binding was also diminished when neutrophils were treated with neuraminidase from Vibrio cholerae, which cleaves alpha 2-3-, alpha 2-6-, and alpha 2-8-linked sialic acids, or from Newcastle disease virus, which cleaves only alpha 2-3- and alpha 2-8-linked sialic acids. Binding was not inhibited by an mAb to the abundant myeloid oligosaccharide, Lex (CD15), or by the neoglycoproteins Lex-BSA and sialyl-Lex-BSA. We conclude that neutrophils constitutively express a glycoprotein receptor for GMP-140, which contains sialic acid residues that are essential for function. These findings support the concept that GMP-140 interacts with leukocytes by a lectin-like mechanism.

  7. 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

  8. A new lectin in red kidney beans called PvFRIL stimulates proliferation of NIH 3T3 cells expressing the Flt3 receptor.

    PubMed

    Moore, J G; Fuchs, C A; Hata, Y S; Hicklin, D J; Colucci, G; Chrispeels, M J; Feldman, M

    2000-07-26

    A new legume lectin has been identified by its ability to specifically stimulate proliferation of NIH 3T3 fibroblasts expressing the Flt3 tyrosine kinase receptor. The lectin was isolated from conditioned medium harvested from human peripheral blood mononuclear cells activated to secrete cytokines by a crude red kidney bean extract containing phytohemagglutinin (PHA). Untransfected 3T3 cells and 3T3 cells transfected with the related Fms tyrosine kinase receptor do not respond to this lectin, which we called PvFRIL (Phaseolus vulgaris Flt3 receptor-interacting lectin). When tested on cord blood mononuclear cells enriched for Flt3-expressing progenitors, purified PvFRIL fractions maintained a small population of cells that continued to express CD34 after 2 weeks in suspension cultures containing IL3. These cultures did not show the effects of IL3's strong induction of proliferation and differentiation (high cell number and exhausted medium); instead, low cell number at the end of the culture period resulted in persistence of cells in the context of cell death. These observations led to the hypothesis that PvFRIL acts in a dominant manner to preserve progenitor viability and prevent proliferation and differentiation. PMID:10913819

  9. The effect of short-wavelength ultraviolet light on antigens, lectin receptors and the ultrastructure of Crithidia fasciculata.

    PubMed

    Santos, M A; Barros, A M; Andrade, P P; Padovan, I P

    1989-01-01

    Crithidia fasciculata is an important trypanosomatid parasite commonly affecting insects and is used extensively as a model for the study of the biochemistry, ultrastructure and organization of the kDNA network of trypanosomatids. The present study describes the evolution of UV-induced morphological changes detectable by transmission electron microscopy in Crithidia fasciculata. Although only rare and minor changes in kinetoplast DNA were demonstrable 7 h after UV irradiation, alterations of this organelle were present in almost all flagellates observed 24 h and 48 h after irradiation. Other cell structures were apparently undamaged. Ultrastructural changes in kDNA did not correspond to changes in antigenicity of protein bands in western blotting against serum from Chagas' disease patients or in the presence of 3 different lectin receptors on the surface of the parasite. PMID:2553178

  10. Toll-like receptors (TLRs) and mannan-binding lectin (MBL): on constant alert in a hostile environment.

    PubMed

    Bergman, Ingrid-Maria

    2011-05-01

    In the beginning were neither B cells nor T cells nor antibodies, but innate immune defense alone. The primary functional theme of innate immunity is the distinction between self and non-self, which is maintained by a vast number of cellular and subcellular components. In this context, the immense importance of the Toll-like receptors (TLRs) is well established. Positive (Darwinian) selection seems to be acting on the ligand-binding domains of these molecules, suggesting a selection pattern similar to that previously observed in the MHC proteins. In sharp contrast to TLRs, the biological significance of mannan-binding lectin (MBL) is controversial, and, concerning humans, it has been suggested that low concentration of MBL in serum represents a selective advantage. In this mini-review, based on a doctoral thesis, evolutionary aspects of TLRs and MBL are discussed. PMID:21323627

  11. Reduced ability of C-type natriuretic peptide (CNP) to activate natriuretic peptide receptor B (NPR-B) causes dwarfism in lbab -/- mice.

    PubMed

    Yoder, Andrea R; Kruse, Andrew C; Earhart, Cathleen A; Ohlendorf, Douglas H; Potter, Lincoln R

    2008-09-01

    C-type natriuretic peptide (CNP) stimulates endochondrial ossification by activating the transmembrane guanylyl cyclase, natriuretic peptide receptor-B (NPR-B). Recently, a spontaneous autosomal recessive mutation that causes severe dwarfism in mice was identified. The mutant, called long bone abnormality (lbab), contains a single point mutation that converts an arginine to a glycine in a conserved coding region of the CNP gene, but how this mutation affects CNP activity has not been reported. Here, we determined that 30-fold to greater than 100-fold more CNP(lbab) was required to activate NPR-B as compared to wild-type CNP in whole cell cGMP elevation and membrane guanylyl cyclase assays. The reduced ability of CNP(lbab) to activate NPR-B was explained, at least in part, by decreased binding since 10-fold more CNP(lbab) than wild-type CNP was required to compete with [125I][Tyr0]CNP for receptor binding. Molecular modeling suggested that the conserved arginine is critical for binding to an equally conserved acidic pocket in NPR-B. These results indicate that reduced binding to and activation of NPR-B causes dwarfism in lbab(-/-) mice. PMID:18554750

  12. 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.

  13. C-type natriuretic peptide activates a non-selective cation current in acutely isolated rat cardiac fibroblasts via natriuretic peptide C receptor-mediated signalling.

    PubMed

    Rose, R A; Hatano, N; Ohya, S; Imaizumi, Y; Giles, W R

    2007-04-01

    In the heart, fibroblasts play an essential role in the deposition of the extracellular matrix and they also secrete a number of hormonal factors. Although natriuretic peptides, including C-type natriuretic peptide (CNP) and brain natriuretic peptide, have antifibrotic effects on cardiac fibroblasts, the effects of CNP on fibroblast electrophysiology have not been examined. In this study, acutely isolated ventricular fibroblasts from the adult rat were used to measure the effects of CNP (2 x 10(-8) M) under whole-cell voltage-clamp conditions. CNP, as well as the natriuretic peptide C receptor (NPR-C) agonist cANF (2 x 10(-8) M), significantly increased an outwardly rectifying non-selective cation current (NSCC). This current has a reversal potential near 0 mV. Activation of this NSCC by cANF was abolished by pre-treating fibroblasts with pertussis toxin, indicating the involvement of G(i) proteins. The cANF-activated NSCC was inhibited by the compounds Gd(3+), SKF 96365 and 2-aminoethoxydiphenyl borate. Quantitative RT-PCR analysis of mRNA from rat ventricular fibroblasts revealed the expression of several transient receptor potential (TRP) channel transcripts. Additional electrophysiological analysis showed that U73122, a phospholipase C antagonist, inhibited the cANF-activated NSCC. Furthermore, the effects of CNP and cANF were mimicked by the diacylglycerol analogue 1-oleoyl-2-acetyl-sn-glycerol (OAG), independently of protein kinase C activity. These are defining characteristics of specific TRPC channels. More detailed molecular analysis confirmed the expression of full-length TRPC2, TRPC3 and TRPC5 transcripts. These data indicate that CNP, acting via the NPR-C receptor, activates a NSCC that is at least partially carried by TRPC channels in cardiac fibroblasts. PMID:17204501

  14. Metformin reduces endothelial cell expression of both the receptor for advanced glycation end products and lectin-like oxidized receptor 1.

    PubMed

    Ouslimani, Nadjat; Mahrouf, Meriem; Peynet, Jacqueline; Bonnefont-Rousselot, Dominique; Cosson, Claudine; Legrand, Alain; Beaudeux, Jean-Louis

    2007-03-01

    Beyond its antihyperglycemic action, the antidiabetic oral drug metformin possesses antioxidant properties that may contribute to improve the cardiovascular deleterious effects of the diabetic disease. We explored whether metformin could modulate the redox-sensible expression of receptor for advanced glycation end products (RAGE) and lectin-like oxidized receptor 1 (LOX-1), 2 endothelial membrane receptors involved in the arterial endothelial dysfunction observed in diabetes. Bovine aortic endothelial cells, either unstimulated or activated by high levels of glucose (30 mmol/L) or advanced glycation end products, were incubated for 72 hours with metformin at therapeutically relevant concentrations (10(-5) to 5 x 10(-4) mol/L). The expressions of RAGE and LOX-1 were evaluated on cell extracts by Western blot analysis. Metformin was shown to reduce, in dose-dependent manner, such expression of the 2 receptors, both in stimulated (by either glucose or advanced glycation end products) and in unstimulated cells. The effect of metformin was associated with a decrease in intracellular reactive oxygen species as assessed using the 2',7'-dichlorodihydrofluorescein diacetate fluoroprobe. Taken together, our results suggest that the intracellular antioxidant properties of metformin may result in the inhibition of cell expression of both RAGE and LOX-1, possibly through a modulation of redox-sensible nuclear factors such as nuclear factor kappaB, that were shown to be involved in such receptor cell expression. PMID:17292717

  15. 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

  16. 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

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

    PubMed

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

    2014-07-01

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

  18. Chronic Aerobic Exercise Decreases Lectin-Like Low Density Lipoprotein (LOX-1) Receptor Expression in Heart of Diabetic Rat

    PubMed Central

    Riahi, Simin; Mohammadi, Mohammad Taghi; Sobhani, Vahid; Ababzadeh, Shima

    2016-01-01

    Background: Overexpression of lectin-like low density lipoprotein (LOX-1) receptor plays an important role in hyperglycemia-induced vascular complications such as atherosclerosis. Based on the beneficial effects of exercise on preventing cardiovascular complications of diabetes, we aimed to examine the protective effects of aerobic exercise on expression of LOX-1 receptor and production of free radicals in the heart of diabetic rats. Methods: Four groups of rats were used: (n = 5 per group): sedentary normal, trained normal, sedentary diabetes and trained diabetes. Diabetes was induced by a single intraperitoneal injection of streptozotocin (50 mg/kg). The exercise protocol was consisted of swimming 30 min/day, 5 days/week for eight weeks. Plasma glucose was evaluated at initiation, weeks 4 and 8 of experiment. At the end of experiment, rats were sacrificed and the heart was removed for determination of nitrate, malondialdehyde, and LOX-1 gene expression. Results: In normal non-diabetic rats, the blood glucose level was <150 mg/dl; however, the induction of diabetes resulted in levels more than >400 mg/dl. Gene expression of LOX-1 was increased in the heart of diabetic rats. Exercise reduced the gene expression of this protein in diabetic states without reducing the blood glucose. Finally, swimming exercise decreased the malondialdehyde and nitrate levels in heart tissue both in control and diabetic rats. Conclusion: Swimming exercise reduces heart expression of the LOX-1 receptor in accompany with reduction of free radicals production. Since these parameters are important in generation of diabetic complications, swimming exercise is a good candidate for reducing these complications. PMID:26432573

  19. Renal tubular receptor imaging with iodine-131-labeled peanut lectin: pharmacokinetics and renal clearance mechanism in animals

    SciTech Connect

    Boniface, G.R.; Suresh, M.R.; Willans, D.J.; Tam, Y.K.; Shysh, A.; Longenecker, B.M.; Noujaim, A.A.

    1986-05-01

    Intravenously administered peanut lectin (PNA), iodinated with /sup 131/I ((/sup 131/I)PNA), is rapidly cleared from the plasma by the kidneys in dogs (clearance (total body) = 17.52 +/- 8.74 ml/min). Dynamic gamma camera renal scintigraphy demonstrated renal accumulation and excretion phases of the (/sup 131/I)PNA renogram in dogs and rabbits (% injection dose-at-peak = 21.8 +/- 3.3% and 19.6 +/- 4.3%, time-to-peak = 44.6 +/- 4.8 min and 37.2 +/- 6.9 min, respectively). Immunoperoxidase staining of kidney sections, following i.v. administered PNA, demonstrated predominant accumulation by the proximal tubules of mice, rabbits, and dogs. The basement membrane was intensely stained at early times p.i. while intracellular and luminal PNA was evident within 1 hr. Urine analysis confirmed the presence of intact (/sup 131/I)PNA in the bladder contents, while protein degradation products, and a small percentage of the free iodide (less than 5%) were noted within 1 hr p.i. The relative proportion of free iodide increased at later times p.i. (greater than 6 hr). A receptor mediated excretion mechanism is proposed for the clearance of PNA and may be useful for the study of renal tubular function.

  20. Lipopolysaccharide augments the uptake of oxidized LDL by up-regulating lectin-like oxidized LDL receptor-1 in macrophages.

    PubMed

    Hossain, Ekhtear; Ota, Akinobu; Karnan, Sivasundaram; Takahashi, Miyuki; Mannan, Shahnewaj B; Konishi, Hiroyuki; Hosokawa, Yoshitaka

    2015-02-01

    There is a growing body of evidence supporting an intimate association of immune activation with the pathogenesis of cardiovascular diseases, including atherosclerosis. Uptake of oxidized low-density lipoprotein (oxLDL) through scavenging receptors promotes the formation of mature lipid-laden macrophages, which subsequently leads to exacerbation of regional inflammation and atherosclerotic plaque formation. In this study, we first examined changes in the mRNA level of the lectin-like oxLDL receptor-1 (LOX-1) in the mouse macrophage cell line RAW264.7 and the human PMA-induced macrophage cell line THP-1 after LPS stimulation. LPS significantly up-regulated LOX-1 mRNA in RAW264.7 cells; LOX-1 cell-surface protein expression was also increased. Flow cytometry and fluorescence microscopy analyses showed that cellular uptake of fluorescence (Dil)-labeled oxLDL was significantly augmented with LPS stimulation. The augmented uptake of Dil-oxLDL was almost completely abrogated by treatment with an anti-LOX-1 antibody. Of note, knockdown of Erk1/2 resulted in a significant reduction of LPS-induced LOX-1 up-regulation. Treatment with U0126, a specific inhibitor of MEK, significantly suppressed LPS-induced expression of LOX-1 at both the mRNA and protein levels. Furthermore, LOX-1 promoter activity was significantly augmented by LPS stimulation; this augmentation was prevented by U0126 treatment. Similar results were also observed in human PMA-induced THP-1 macrophages. Taken together, our results indicate that LPS up-regulates LOX-1, at least in part through activation of the Erk1/2 signaling pathway, followed by augmented cellular oxLDL uptake, thus highlighting a critical role of TLR4-mediated aberrant LOX-1 signaling in the pathogenesis of atherosclerosis. PMID:25348362

  1. Enhancement of angiogenesis by a 27 kDa lectin from perivitelline fluid of horseshoe crab embryos through upregulation of VEGF and its receptor.

    PubMed

    Surekha, K L; Waghchoude, Meenal; Ghaskadbi, Surendra

    2013-01-25

    Angiogenesis, the expansion of a capillary network, is implicated in several pathological conditions. Drug-based inhibition of angiogenesis is being explored as therapy. Conversely, therapeutic angiogenesis contributes to control conditions such as ischemia. Here we report pro-angiogenic activity of perivitelline fluid (PVF) from Indian horseshoe crab embryos and one of its purified fractions, a 27 kDa lectin, using the chick embryonic chorioallantoic membrane assay. Enhancement in number and diameter of blood vessels after treatment with PVF and lectin suggested their pro-angiogenic effect. Quantitative RT-PCR showed that this effect is mediated through modulation of expression of VEGF and VEGFR-2/kinase domain receptor genes. PMID:23316979

  2. DEFINITIVE ROLE FOR NATRIURETIC PEPTIDE RECEPTOR-C IN MEDIATING THE VASORELAXANT ACTIVITY OF C-TYPE NATRIURETIC PEPTIDE AND ENDOTHELIUM-DERIVED HYPERPOLARISING FACTOR

    PubMed Central

    Villar, Inmaculada C.; Panayiotou, Catherine M.; Sheraz, Adil; Madhani, Melanie; Scotland, Ramona S.; Nobles, Muriel; Kemp-Harper, Barbara; Ahluwalia, Amrita; Hobbs, Adrian J.

    2012-01-01

    Objective C-type natriuretic peptide (CNP) has recently been suggested to represent an endothelium-derived hyperpolarizing factor (EDHF) in the mammalian resistance vasculature, important in the regulation of local blood flow and systemic blood pressure. Additionally, this peptide has been shown to protect against ischaemia-reperfusion injury and inhibits leukocyte and platelet activation. Herein, we use a novel, selective natriuretic peptide receptor-C (NPR-C) antagonist (M372049) to highlight the pivotal contribution of CNP/NPR-C signalling in the EDHF-dependent regulation of vascular tone and investigate the mechanism(s) underlying the release and biological activity of CNP and EDHF. Methods In vitro pharmacological investigation was conducted in rat (Sprague-Dawley) aorta and mesenteric resistance arteries. Relaxant responses to CNP, atrial natriuretic peptide (ANP), the nitric oxide donor spermine-NONOate (SPER-NO) and the endothelium-dependent vasodilator, acetylcholine (ACh) were examined in the absence and presence of M372049 or inhibitor cocktails shown previously to block endothelium-dependent dilatation in the resistance vasculature. RT-PCR was employed to characterize the expression of NPR subtypes in the vessels studied. Results M372049 produced concentration-dependent inhibition of the vasorelaxant activity of CNP in rat isolated mesenteric resistance arteries but not aorta; in contrast, M372049 did not affect relaxations to ANP or SPER-NO in either vessel. M372049 or ouabain alone produced small, significant inhibition of EDHF-dependent relaxations in mesenteric arteries and in combination acted synergistically to abolish such responses. A combination of M372049 with established inhibitors of EDHF-dependent relaxation revealed that multiple, distinct pathways coordinate the bioactivity of EDHF in the resistance vasculature, and that CNP/NPR-C signalling represents a major component. Conclusions These data substantiate CNP/NPR-C signalling as a

  3. The Escherichia coli G-fimbrial lectin protein participates both in fimbrial biogenesis and in recognition of the receptor N-acetyl-D-glucosamine.

    PubMed Central

    Saarela, S; Taira, S; Nurmiaho-Lassila, E L; Makkonen, A; Rhen, M

    1995-01-01

    The gafD gene encoding the N-acetyl-D-glucosamine-specific fimbrial lectin (adhesin) protein GafD of uropathogenic Escherichia coli was cloned and subjected to genetic analysis. The corresponding gene product was isolated as a MalE fusion protein. The lectin gene was identified with the aid of deletion mutagenesis; mutations in gafD impaired either receptor binding or both receptor binding and fimbria production, depending on the mutation created. All mutants converted to wild-type expressors when complemented in trans with the cloned intact gafD gene. The predicted 354-amino-acid sequence of GafD, deduced from the nucleotide sequence, is closely related to those of the fimbria-associated F17-G and F17b-G proteins coded for by enterotoxigenic and invasive E. coli strains. Isolated GafD was shown to recognize N-acetyl-D-glucosamine by virtue of specific binding to an immobilized receptor, thus proving directly that GafD is a sugar-binding protein. Our results indicate that GafD as such is sufficient for receptor recognition and that the protein also participates in fimbrial biogenesis. PMID:7883703

  4. Association between soluble lectin-like oxidized low-density lipoprotein receptor 1 levels and coronary slow flow phenomenon

    PubMed Central

    Caglar, Ilker Murat; Ozde, Cem; Caglar, Fatma Nihan Turhan; Akturk, Ibrahim Faruk; Ugurlucan, Murat; Karakaya, Osman

    2016-01-01

    Introduction The coronary slow flow phenomenon (CSFP) has been associated with myocardial ischemia, myocardial infarction, life-threatening arrhythmias, sudden cardiac death and increased cardiovascular mortality similar to coronary artery disease (CAD). Possible underlying mechanisms of CSFP are endothelial dysfunction, chronic inflammation, microvascular dysfunction and diffuse atherosclerosis. Soluble lectin-like oxidized low-density lipoprotein receptor-1 (sLOX-1) seems to play an important role in the pathogenesis of atherosclerosis. We hypothesized that sLOX-1 might be associated with CSFP, and aimed to research the relationship between sLOX-1 and CSFP. Material and methods Forty patients with angiographically proven CSFP and 43 patients with a normal coronary flow pattern (NCFP) were included in this study. Coronary blood flow was measured according to the Thrombolysis In Myocardial Infarction (TIMI) frame count method. sLOX-1 levels were measured in all study subjects. Results Serum levels of sLOX-1 were significantly higher in the CSFP group than the NCFP group (1061.80 ±422.20 ng/ml vs. 500.043 ±282.97 ng/ml, p < 0.001, respectively). Multivariate logistic regression analysis including sLOX-1, MPV, GGT and uric acid levels revealed a significant association between sLOX-1 levels and CSFP (Exp (B)/OR: 1.006, 95% CI: 1.002–1.010, p = 0.001). Conclusions The present study demonstrated that serum sLOX-1 levels were significantly higher in patients with CSFP and there was a strong association between high sLOX-1 levels and CSFP. High serum sLOX-1 levels may have an important role in the pathogenesis of CSFP. Future studies are needed to confirm these results. PMID:26925116

  5. The novel platelet activation receptor CLEC-2.

    PubMed

    Suzuki-Inoue, Katsue; Inoue, Osamu; Ozaki, Yukio

    2011-01-01

    The c-type lectin-like receptor 2 (CLEC-2) was first identified from a bio-informatic screen for c-type lectin-like receptors. However, neither its function nor its ligand(s) had been elucidated for several years. In 2006, we reported that the receptor is expressed on the surface of platelets and serves as a receptor for the snake venom rhodocytin, which potently stimulates platelet aggregation. Since then CLEC-2 has been intensively investigated, and its endogenous/exogenous ligands and several physiological/pathological roles have been clarified. In this article and its accompanying poster, we outline the structure, distribution, signal transduction mechanism and functions of CLEC-2. PMID:21714702

  6. Structural and antigenic types of cell wall polysaccharides from viridans group streptococci with receptors for oral actinomyces and streptococcal lectins.

    PubMed

    Cisar, J O; Sandberg, A L; Reddy, G P; Abeygunawardana, C; Bush, C A

    1997-12-01

    Lectin-mediated interactions between oral viridans group streptococci and actinomyces may play an important role in microbial colonization of the tooth surface. The presence of two host-like motifs, either GalNAc beta1-->3Gal (Gn) or Gal beta1-->3GalNAc (G), in the cell wall polysaccharides of five streptococcal strains accounts for the lactose-sensitive coaggregations of these bacteria with Actinomyces naeslundii. Three streptococcal strains which have Gn-containing polysaccharides also participate in GalNAc-sensitive coaggregations with strains of Streptococcus gordonii and S. sanguis. Each Gn- or G-containing polysaccharide is composed of a distinct phosphodiester-linked hexa- or heptasaccharide repeating unit. The occurrence of these polysaccharides on 19 additional viridans group streptococcal strains that participate in lactose-sensitive coaggregations with actinomyces was examined. Negatively charged polysaccharides that reacted with Bauhinia purpurea agglutinin, a Gal and GalNAc binding plant lectin, were isolated from 17 strains by anion exchange column chromatography of mutanolysin-cell wall digests. Results from nuclear magnetic resonance and immunodiffusion identified each of 16 polysaccharides as a known Gn- or G-containing structural type and one polysaccharide as a new but closely related Gn-containing type. Unlike the reactions of lectins, the cross-reactions of most rabbit antisera with these polysaccharides were correlated with structural features other than the host-like motifs. Gn-containing polysaccharides occurred primarily on the strains of S. sanguis and S. oralis while G-containing polysaccharides were more common among the strains of S. gordonii and S. mitis examined. The findings strongly support the hypothesis that lectin-mediated recognition of these streptococci by other oral bacteria depends on a family of antigenically diverse Gn- and G-containing cell wall polysaccharides, the occurrence of which may differ between streptococcal

  7. Structural and antigenic types of cell wall polysaccharides from viridans group streptococci with receptors for oral actinomyces and streptococcal lectins.

    PubMed Central

    Cisar, J O; Sandberg, A L; Reddy, G P; Abeygunawardana, C; Bush, C A

    1997-01-01

    Lectin-mediated interactions between oral viridans group streptococci and actinomyces may play an important role in microbial colonization of the tooth surface. The presence of two host-like motifs, either GalNAc beta1-->3Gal (Gn) or Gal beta1-->3GalNAc (G), in the cell wall polysaccharides of five streptococcal strains accounts for the lactose-sensitive coaggregations of these bacteria with Actinomyces naeslundii. Three streptococcal strains which have Gn-containing polysaccharides also participate in GalNAc-sensitive coaggregations with strains of Streptococcus gordonii and S. sanguis. Each Gn- or G-containing polysaccharide is composed of a distinct phosphodiester-linked hexa- or heptasaccharide repeating unit. The occurrence of these polysaccharides on 19 additional viridans group streptococcal strains that participate in lactose-sensitive coaggregations with actinomyces was examined. Negatively charged polysaccharides that reacted with Bauhinia purpurea agglutinin, a Gal and GalNAc binding plant lectin, were isolated from 17 strains by anion exchange column chromatography of mutanolysin-cell wall digests. Results from nuclear magnetic resonance and immunodiffusion identified each of 16 polysaccharides as a known Gn- or G-containing structural type and one polysaccharide as a new but closely related Gn-containing type. Unlike the reactions of lectins, the cross-reactions of most rabbit antisera with these polysaccharides were correlated with structural features other than the host-like motifs. Gn-containing polysaccharides occurred primarily on the strains of S. sanguis and S. oralis while G-containing polysaccharides were more common among the strains of S. gordonii and S. mitis examined. The findings strongly support the hypothesis that lectin-mediated recognition of these streptococci by other oral bacteria depends on a family of antigenically diverse Gn- and G-containing cell wall polysaccharides, the occurrence of which may differ between streptococcal

  8. Solution Structure and Sugar-Binding Mechanism of Mouse Latrophilin-1 RBL: a 7TM Receptor-Attached Lectin-Like Domain

    PubMed Central

    Vakonakis, Ioannis; Langenhan, Tobias; Prömel, Simone; Russ, Andreas; Campbell, Iain D.

    2008-01-01

    Summary Latrophilin-1 (Lat-1), a target receptor for α-Latrotoxin, is a putative G protein-coupled receptor implicated in synaptic function. The extracellular portion of Lat-1 contains a rhamnose binding lectin (RBL)-like domain of unknown structure. RBL domains, first isolated from the eggs of marine species, are also found in the ectodomains of other metazoan transmembrane proteins, including a recently discovered coreceptor of the neuronal axon guidance molecule SLT-1/Slit. Here, we describe a structure of this domain from the mouse Lat-1. RBL adopts a unique α/β fold with long structured loops important for monosaccharide recognition, as shown in the structure of a complex with L-rhamnose. Sequence alignments and mutagenesis show that residues important for carbohydrate binding are often absent in other receptor-attached examples of RBL, including the SLT-1/Slit coreceptor. We postulate that this domain class facilitates direct protein-protein interactions in many transmembrane receptors. PMID:18547526

  9. Mitogenic activity of edible mushroom lectins.

    PubMed

    Ho, J C K; Sze, S C W; Shen, W Z; Liu, W K

    2004-03-17

    A special group of lectins were isolated from three popular Asian edible mushrooms: Volvariella volvacea, Pleurotus flabellatus and Hericium erinacium, and their mitogenic activities towards mouse T cells were compared to the extensively investigated Agaricus bisporus lectin (ABL) and the Jack bean lectin, Concanavalin A (Con A). Among the four mushroom lectins tested, V. volvacea lectin (VVL) exhibited strong mitogenic activity as demonstrated by 3H-thymidine incorporation, which was at least 10-fold more effective than that of Con A, and the other mushroom lectins did not exhibit any proliferative activity. Treatment with VVL and ABL resulted in activation of the protein tyrosine kinase, p56lck, and expression of early activation markers, CD69 and CD25, but only VVL induced intracellular calcium influx while ABL triggered cell death. The calcium influx was sensitive to calcium channel antagonists such as nifedipine and verapamil. The P. flabellatus lectin (PFL) and H. erinacium lectin (HEL) did not stimulate p56lck expression and cell proliferation. Neither of these lectins interfered with Con A-mediated lymphocyte proliferation, which further indicated that both PFL and HEL were non-mitogenic. Taken all results together, VVL induced mitogenesis through T cell receptors and the subsequent calcium signaling pathway. PMID:15026140

  10. Lectin-like oxidized low-density lipoprotein receptor-1 abrogation causes resistance to inflammatory bone destruction in mice, despite promoting osteoclastogenesis in the steady state.

    PubMed

    Nakayachi, Mai; Ito, Junta; Hayashida, Chiyomi; Ohyama, Yoko; Kakino, Akemi; Okayasu, Mari; Sato, Takuya; Ogasawara, Toru; Kaneda, Toshio; Suda, Naoto; Sawamura, Tatsuya; Hakeda, Yoshiyuki

    2015-06-01

    Inflammatory bone diseases have been attributed to increased bone resorption by augmented and activated bone-resorbing osteoclasts in response to inflammation. Although the production of diverse proinflammatory cytokines is induced at the inflamed sites, the inflammation also generates reactive oxygen species that modify many biological compounds, including lipids. Among the oxidized low-density lipoprotein (LDL) receptors, lectin-like oxidized LDL receptor-1 (LOX-1), which is a key molecule in the pathogenesis of multifactorial inflammatory atherosclerosis, was downregulated with osteoclast differentiation. Here, we demonstrate that LOX-1 negatively regulates osteoclast differentiation by basically suppressing the cell-cell fusion of preosteoclasts. The LOX-1-deleted (LOX-1(-/-)) mice consistently decreased the trabecular bone mass because of elevated bone resorption during the growing phase. In contrast, when the calvaria was inflamed by a local lipopolysaccharide-injection, the inflammation-induced bone destruction accompanied by the elevated expression of osteoclastogenesis-related genes was reduced by LOX-1 deficiency. Moreover, the expression of receptor activator of NF-κB ligand (RANKL), a trigger molecule for osteoclast differentiation, evoked by the inflammation was also abrogated in the LOX-1(-/-) mice. Osteoblasts, the major producers of RANKL, also expressed LOX-1 in response to proinflammatory agents, interleukin-1β and prostaglandin E2. In the co-culture of LOX-1(-/-) osteoblasts and wild-type osteoclast precursors, the osteoclastogenesis induced by interleukin-1β and prostaglandin E2 decreased; this process occurred in parallel with the downregulation of osteoblastic RANKL expression. Collectively, LOX-1 abrogation results in resistance to inflammatory bone destruction, despite promoting osteoclastogenesis in the steady state. Our findings indicate the novel involvement of LOX-1 in physiological bone homeostasis and inflammatory bone diseases

  11. 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. PMID:22565020

  12. Inhibition of lectin-like oxidized low-density lipoprotein receptor-1 reduces cardiac fibroblast proliferation by suppressing GATA Binding Protein 4.

    PubMed

    Liu, Bin; Liu, Ning-Ning; Liu, Wei-Hua; Zhang, Shuang-Wei; Zhang, Jing-Zhi; Li, Ai-Qun; Liu, Shi-Ming

    2016-07-01

    Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) and GATA Binding Protein 4 (GATA4) are important for the growth of cardiac fibroblasts (CFs). When deregulated, LOX-1 and GATA4 can cause cardiac remodeling. In the present study, we found novel evidence that GATA4 was required for the LOX-1 regulation of CF proliferation. The inhibition of LOX-1 by RNA interference LOX-1 lentivirus resulted in the loss of PI3K/Akt activation and GATA4 protein expression. The overexpression of LOX-1 by lentivirus rescued CF proliferation, PI3K/Akt activation, and GATA4 protein expression. Moreover, GATA4 overexpression enhanced CF proliferation with LOX-1 inhibition. We also found that the inhibition of PI3K/Akt activation by LY294002, a PI3K inhibitor, reduced cell proliferation and protein level of GATA4. In summary, GATA4 may play an important role in the LOX-1 and PI3K/Akt regulation of CF proliferation. PMID:27216460

  13. Therapeutic Administration of KM+ Lectin Protects Mice Against Paracoccidioides brasiliensis Infection via Interleukin-12 Production in a Toll-Like Receptor 2-Dependent Mechanism

    PubMed Central

    Coltri, Kely C.; Oliveira, Leandro L.; Pinzan, Camila F.; Vendruscolo, Patrícia E.; Martinez, Roberto; Goldman, Maria Helena; Panunto-Castelo, Ademilson; Roque-Barreira, Maria-Cristina

    2008-01-01

    KM+ is a mannose-binding lectin from Artocarpus integrifolia that induces interleukin (IL)-12 production by macrophages and protective T helper 1 immune response against Leishmania major infection. In this study, we performed experiments to evaluate the therapeutic activity of jackfruit KM+ (jfKM+) and its recombinant counterpart (rKM+) in experimental paracoccidioidomycosis. To this end, jfKM+ or rKM+ was administered to BALB/c mice 10 days after infection with Paracoccidiodes brasiliensis. Thirty days postinfection, lungs from the KM+-treated mice contained significantly fewer colony-forming units and little to no organized granulomas compared to the controls. In addition, lung homogenates from the KM+-treated mice presented higher levels of nitric oxide, IL-12, interferon-γ, and tumor necrosis factor-α, whereas higher levels of IL-4 and IL-10 were detected in the control group. With mice deficient in IL-12, Toll-like receptor (TLR) 2, TLR4, or TLR adaptor molecule MyD88, we demonstrated that KM+ led to protection against P. brasiliensis infection through IL-12 production, which was dependent on TLR2. These results demonstrated a beneficial effect of KM+ on the severity of P. brasiliensis infection and may expand its potential use as a novel immunotherapeutic molecule. PMID:18599609

  14. Mincle, the receptor for mycobacterial cord factor, forms a functional receptor complex with MCL and FcεRI-γ.

    PubMed

    Lobato-Pascual, Ana; Saether, Per Christian; Fossum, Sigbjørn; Dissen, Erik; Daws, Michael R

    2013-12-01

    Upon receptor activation, the myeloid C-type lectin receptor Mincle signals via the Syk-CARD9-Bcl10-MALT1 pathway. It does so by recruiting the ITAM-bearing FcεRI-γ. The related receptor macrophage C-type Lectin (MCL) has also been shown to be associated with Syk and to be dependent upon this signaling axis. We have previously shown that MCL co-precipitates with FcεRI-γ, but were unable to show a direct association, suggesting that MCL associates with FcεRI-γ via another molecule. Here, we have used rat primary cells and cell lines to investigate this missing link. A combination of flow cytometric and biochemical analysis showed that Mincle and MCL form heteromers on the cell surface. Furthermore, association with MCL and FcεRI-γ increased Mincle expression and enhanced phagocytosis of Ab-coated beads. The results presented in this paper suggest that the Mincle/MCL/FcεRI-γ complex is the functionally optimal form for these C-type lectin receptors on the surface of myeloid cells. PMID:23921530

  15. Diversified Carbohydrate-Binding Lectins from Marine Resources

    PubMed Central

    Ogawa, Tomohisa; Watanabe, Mizuki; Naganuma, Takako; Muramoto, Koji

    2011-01-01

    Marine bioresources produce a great variety of specific and potent bioactive molecules including natural organic compounds such as fatty acids, polysaccharides, polyether, peptides, proteins, and enzymes. Lectins are also one of the promising candidates for useful therapeutic agents because they can recognize the specific carbohydrate structures such as proteoglycans, glycoproteins, and glycolipids, resulting in the regulation of various cells via glycoconjugates and their physiological and pathological phenomenon through the host-pathogen interactions and cell-cell communications. Here, we review the multiple lectins from marine resources including fishes and sea invertebrate in terms of their structure-activity relationships and molecular evolution. Especially, we focus on the unique structural properties and molecular evolution of C-type lectins, galectin, F-type lectin, and rhamnose-binding lectin families. PMID:22312473

  16. 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

  17. Lectins discriminate between pathogenic and nonpathogenic South American trypanosomes

    SciTech Connect

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

    1984-09-01

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

  18. Arsenic augments the uptake of oxidized LDL by upregulating the expression of lectin-like oxidized LDL receptor in mouse aortic endothelial cells

    SciTech Connect

    Hossain, Ekhtear; Ota, Akinobu; Karnan, Sivasundaram; Damdindorj, Lkhagvasuren; Takahashi, Miyuki; Konishi, Yuko; Konishi, Hiroyuki; Hosokawa, Yoshitaka

    2013-12-15

    Although chronic arsenic exposure is a well-known risk factor for cardiovascular diseases, including atherosclerosis, the molecular mechanism underlying arsenic-induced atherosclerosis remains obscure. Therefore, this study aimed to elucidate this molecular mechanism. We examined changes in the mRNA level of the lectin-like oxidized LDL (oxLDL) receptor (LOX-1) in a mouse aortic endothelial cell line, END-D, after sodium arsenite (SA) treatment. SA treatment significantly upregulated LOX-1 mRNA expression; this finding was also verified at the protein expression level. Flow cytometry and fluorescence microscopy analyses showed that the cellular uptake of fluorescence (Dil)-labeled oxLDL was significantly augmented with SA treatment. In addition, an anti-LOX-1 antibody completely abrogated the augmented uptake of Dil-oxLDL. We observed that SA increased the levels of the phosphorylated forms of nuclear factor of kappa light polypeptide gene enhancer in B cells (NF-κB)/p65. SA-induced upregulation of LOX-1 protein expression was clearly prevented by treatment with an antioxidant, N-acetylcysteine (NAC), or an NF-κB inhibitor, caffeic acid phenethylester (CAPE). Furthermore, SA-augmented uptake of Dil-oxLDL was also prevented by treatment with NAC or CAPE. Taken together, our results indicate that arsenic upregulates LOX-1 expression through the reactive oxygen species-mediated NF-κB signaling pathway, followed by augmented cellular oxLDL uptake, thus highlighting a critical role of the aberrant LOX-1 signaling pathway in the pathogenesis of arsenic-induced atherosclerosis. - Highlights: • Sodium arsenite (SA) increases LOX-1 expression in mouse aortic endothelial cells. • SA enhances cellular uptake of oxidized LDL in dose-dependent manner. • SA-induced ROS generation enhances phosphorylation of NF-κB. • SA upregulates LOX-1 expression through ROS-activated NF-κB signaling pathway.

  19. Structure and binding analysis of Polyporus squamosus lectin in complex with the Neu5Ac[alpha]2-6Gal[beta]1-4GlcNAc human-type influenza receptor

    SciTech Connect

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

    2013-03-07

    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 Neu5Ac{alpha}2-6Gal{beta}. Because of its importance as a histological reagent, the PSL structure was solved (to 1.7 {angstrom}) in complex with a trisaccharide, whose sequence (Neu5Ac{alpha}2-6Gal{beta}1-4GlcNAc) 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 Neu5Ac{alpha}2-6Gal 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.

  20. Lectin-like ox-LDL receptor-1 (LOX-1)-Toll-like receptor 4 (TLR4) interaction and autophagy in CATH.a differentiated cells exposed to angiotensin II.

    PubMed

    Ding, Zufeng; Liu, Shijie; Wang, Xianwei; Khaidakov, Magomed; Dai, Yao; Deng, Xiaoyan; Fan, Yubo; Xiang, David; Mehta, Jawahar L

    2015-04-01

    Toll-like receptors (TLRs) play an essential role in innate immune response. Expression of TLRs has also been linked to autophagy. As the main receptor for oxidized low-density lipoprotein (ox-LDL) on the cell surface, lectin-like ox-LDL receptor-1 (LOX-1) is upregulated by proinflammatory cytokines and has been linked to the development of autophagy. However, the relationship between LOX-1, autophagy, and TLR4 in neurons has not been defined. Here, we show that Angiotensin II (Ang II) treatment of CATH.a differentiated neuronal cells resulted in the expression of TLR4 (and associated signals MyD88 and Toll/interleukin-1 receptor domain-containing adapter-inducing interferon (TRIF)), LOX-1 autophagy. LOX-1 knockdown (transfection with specific small interfering RNA (siRNA)) resulted in reduced expression of TLR4 (and associated signals MyD88 and TRIF) and P-P38 mitogen-activated protein kinase (MAPK) and autophagy. TLR4 knockdown with siRNA resulted in reduced LOX-1 expression and autophagy, indicating a positive feedback between LOX-1 and TLR4. Knockdown of TRIF as well as MyD88 or inhibition of P38 MAPK also inhibited the expression of LOX-1 and TLR4 and autophagy. Importantly, pretreatment with 3-methyladenine (autophagy inhibitor) enhanced while rapamycin (autophagy inducer) decreased the expression of LOX-1, TLR4, and P-P38 MAPK. These studies suggest the presence of a bidirectional link between LOX-1and TLR4 in cultured CATH.a differentiated cells exposed to Ang II with an important role for autophagy in this link. PMID:24902807

  1. Sugared biomaterial binding lectins: achievements and perspectives.

    PubMed

    Bojarová, P; Křen, V

    2016-07-19

    Lectins, a distinct group of glycan-binding proteins, play a prominent role in the immune system ranging from pathogen recognition and tuning of inflammation to cell adhesion or cellular signalling. The possibilities of their detailed study expanded along with the rapid development of biomaterials in the last decade. The immense knowledge of all aspects of glycan-lectin interactions both in vitro and in vivo may be efficiently used in bioimaging, targeted drug delivery, diagnostic and analytic biological methods. Practically applicable examples comprise photoluminescence and optical biosensors, ingenious three-dimensional carbohydrate microarrays for high-throughput screening, matrices for magnetic resonance imaging, targeted hyperthermal treatment of cancer tissues, selective inhibitors of bacterial toxins and pathogen-recognising lectin receptors, and many others. This review aims to present an up-to-date systematic overview of glycan-decorated biomaterials promising for interactions with lectins, especially those applicable in biology, biotechnology or medicine. The lectins of interest include galectin-1, -3 and -7 participating in tumour progression, bacterial lectins from Pseudomonas aeruginosa (PA-IL), E. coli (Fim-H) and Clostridium botulinum (HA33) or DC-SIGN, receptors of macrophages and dendritic cells. The spectrum of lectin-binding biomaterials covered herein ranges from glycosylated organic structures, calixarene and fullerene cores over glycopeptides and glycoproteins, functionalised carbohydrate scaffolds of cyclodextrin or chitin to self-assembling glycopolymer clusters, gels, micelles and liposomes. Glyconanoparticles, glycan arrays, and other biomaterials with a solid core are described in detail, including inorganic matrices like hydroxyapatite or stainless steel for bioimplants. PMID:27075026

  2. Lectin-binding properties of Aeromonas caviae strains

    PubMed Central

    Rocha-de-Souza, Cláudio M.; Hirata-Jr, Raphael; Mattos-Guaraldi, Ana L.; Freitas-Almeida, Angela C.; Andrade, Arnaldo F. B.

    2008-01-01

    The cell surface carbohydrates of four strains of Aeromonas caviae were analyzed by agglutination and lectin-binding assays employing twenty highly purified lectins encompassing all sugar specificities. With the exception of L-fucose and sialic acid, the sugar residues were detected in A. caviae strains. A marked difference, however, in the pattern of cell surface carbohydrates in different A. caviae isolates was observed. Specific receptors for Tritricum vulgaris (WGA), Lycopersicon esculentum (LEL) and Solanum tuberosum (STA) (D-GlcNAc-binding lectins) were found only in ATCC 15468 strain, whereas Euonymus europaeus (EEL, D-Gal-binding lectin) sites were present exclusively in AeQ32 strain, those for Helix pomatia (HPA, D-GalNAc-binding lectin) in AeC398 and AeV11 strains, and for Canavalia ensiformes (Con A, D-Man-binding lectin) in ATCC 15468, AeC398, AeQ32 and AeV11 strains, after bacterial growing at 37°C. On the other hand, specific receptors for WGA and EEL were completely abrogated growing the bacteria at 22°C. Binding studies with 125I- labeled lectins from WGA, EEL and Con A were performed. These assays essentially confirmed the selectivity, demonstrated in the agglutination assays of these lectins for the A. caviae strains. PMID:24031204

  3. Lectins of marine hydrobionts.

    PubMed

    Chernikov, O V; Molchanova, V I; Chikalovets, I V; Kondrashina, A S; Li, W; Lukyanov, P A

    2013-07-01

    Data from the literature and results of our research on lectins isolated from some kinds of marine hydrobionts such as clams, ascidians, sea worms, sponges, and algae are presented in this review. Results of comparative analysis of the basic physicochemical properties and biological activity of lectins isolated from various sources are discussed. PMID:24010839

  4. Lectin-like oxidized LDL receptor-1 expresses in mouse bone marrow-derived mesenchymal stem cells and stimulates their proliferation

    SciTech Connect

    Zhang, Fenxi; Wang, Congrui; Jing, Suhua; Ren, Tongming; Li, Yonghai; Cao, Yulin; Lin, Juntang

    2013-04-15

    The bone marrow-derived mesenchymal stem cells (bmMSCs) have been widely used in cell transplant therapy, and the proliferative ability of bmMSCs is one of the determinants of the therapy efficiency. Lectin-like oxidized low density lipoprotein receptor-1 (LOX-1) as a transmembrane protein is responsible for binding, internalizing and degrading oxidized low density lipoprotein (ox-LDL). It has been identified that LOX-1 is expressed in endothelial cells, vascular smooth muscle cells, cardiomyocytes, fibroblasts and monocytes. In these cells, low concentration of ox-LDL (<40 μg/mL) stimulates their proliferation via LOX-1 activation. However, it is poor understood that whether LOX-1 is expressed in bmMSCs and which role it plays. In this study, we investigated the status of LOX-1 expression in bmMSCs and its function on bmMSC proliferation. Our results showed that primary bmMSCs exhibiting a typical fibroblast-like morphology are positive for CD44 and CD90, but negative for CD34 and CD45. LOX-1 in both mRNA and protein levels is highly expressed in bmMSCs. Meanwhile, bmMSCs exhibit a strong potential to take up ox-LDL. Moreover, LOX-1 expression in bmMSCs is upregulated by ox-LDL with a dose- and time-dependent manner. Presence of ox-LDL also enhances the proliferation of bmMSCs. Knockdown of LOX-1 expression significantly inhibits ox-LDL-induced bmMSC proliferation. These findings indicate that LOX-1 plays a role in bmMSC proliferation. - Highlights: ► LOX-1 expresses in bmMSCs and mediates uptake of ox-LDL. ► Ox-LDL stimulates upregulation of LOX-1 in bmMSCs. ► Ox-LDL promotes bmMSC proliferation and expression of Mdm2, phosphor-Akt, phosphor-ERK1/2 and phosphor-NF-κB. ► LOX-1 siRNA inhibits ox-LDL-induced bmMSC proliferation and expression cell survival signals.

  5. Signalling through MyD88 drives surface expression of the mycobacterial receptors MCL (Clecsf8, Clec4d) and Mincle (Clec4e) following microbial stimulation.

    PubMed

    Kerscher, Bernhard; Dambuza, Ivy M; Christofi, Maria; Reid, Delyth M; Yamasaki, Sho; Willment, Janet A; Brown, Gordon D

    2016-01-01

    The heterodimeric mycobacterial receptors, macrophage C-type lectin (MCL) and macrophage inducible C-type lectin (Mincle), are upregulated at the cell surface following microbial challenge, but the mechanisms underlying this response are unclear. Here we report that microbial stimulation triggers Mincle expression through the myeloid differentiation primary response gene 88 (MyD88) pathway; a process that does not require MCL. Conversely, we show that MCL is constitutively expressed but retained intracellularly until Mincle is induced, whereupon the receptors form heterodimers which are translocated to the cell surface. Thus this "two-step" model for induction of these key receptors provides new insights into the underlying mechanisms of anti-mycobacterial immunity. PMID:27005451

  6. Oxidized LDL (oxLDL) activates the angiotensin II type 1 receptor by binding to the lectin-like oxLDL receptor.

    PubMed

    Yamamoto, Koichi; Kakino, Akemi; Takeshita, Hikari; Hayashi, Norihiro; Li, Lei; Nakano, Atsushi; Hanasaki-Yamamoto, Hiroko; Fujita, Yoshiko; Imaizumi, Yuki; Toyama-Yokoyama, Serina; Nakama, Chikako; Kawai, Tatsuo; Takeda, Masao; Hongyo, Kazuhiro; Oguro, Ryosuke; Maekawa, Yoshihiro; Itoh, Norihisa; Takami, Yoichi; Onishi, Miyuki; Takeya, Yasushi; Sugimoto, Ken; Kamide, Kei; Nakagami, Hironori; Ohishi, Mitsuru; Kurtz, Theodore W; Sawamura, Tatsuya; Rakugi, Hiromi

    2015-08-01

    The angiotensin II type 1 receptor (AT1) is a 7-transmembrane domain GPCR that when activated by its ligand angiotensin II, generates signaling events promoting vascular dysfunction and the development of cardiovascular disease. Here, we show that the single-transmembrane oxidized LDL (oxLDL) receptor (LOX-1) resides in proximity to AT1 on cell-surface membranes and that binding of oxLDL to LOX-1 can allosterically activate AT1-dependent signaling events. oxLDL-induced signaling events in human vascular endothelial cells were abolished by knockdown of AT1 and inhibited by AT1 blockade (ARB). oxLDL increased cytosolic G protein by 350% in Chinese hamster ovary (CHO) cells with genetically induced expression of AT1 and LOX-1, whereas little increase was observed in CHO cells expressing only LOX-1. Immunoprecipitation and in situ proximity ligation assay (PLA) assays in CHO cells revealed the presence of cell-surface complexes involving LOX-1 and AT1. Chimeric analysis showed that oxLDL-induced AT1 signaling events are mediated via interactions between the intracellular domain of LOX-1 and AT1 that activate AT1. oxLDL-induced impairment of endothelium-dependent vascular relaxation of vascular ring from mouse thoracic aorta was abolished by ARB or genetic deletion of AT1. These findings reveal a novel pathway for AT1 activation and suggest a new mechanism whereby oxLDL may be promoting risk for cardiovascular disease. PMID:25877213

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

    PubMed

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

    2014-03-01

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

  8. The insecticidal activity of recombinant garlic lectins towards aphids.

    PubMed

    Fitches, Elaine; Wiles, Duncan; Douglas, Angela E; Hinchliffe, Gareth; Audsley, Neil; Gatehouse, John A

    2008-10-01

    The heterodimeric and homodimeric garlic lectins ASAI and ASAII were produced as recombinant proteins in the yeast Pichia pastoris. The proteins were purified as functional dimeric lectins, but underwent post-translational proteolysis. Recombinant ASAII was a single homogenous polypeptide which had undergone C-terminal processing similar to that occurring in planta. The recombinant ASAI was glycosylated and subject to variable and heterogenous proteolysis. Both lectins showed insecticidal effects when fed to pea aphids (Acyrthosiphon pisum) in artificial diet, ASAII being more toxic than ASAI at the same concentration. Acute toxicity (mortality at < or =48 h exposure; similar timescale to starvation) was only apparent at the highest lectin concentrations tested (2.0 mg ml(-)1), but dose-dependent chronic toxicity (mortality at >3d exposure) was observed over the concentration range 0.125-2.0 mg ml(-1). The recombinant lectins caused mortality in both symbiotic and antibiotic-treated aphids, showing that toxicity is not dependent on the presence of the bacterial symbiont (Buchnera aphidicola), or on interaction with symbiont proteins, such as the previously identified lectin "receptor" symbionin. A pull-down assay coupled with peptide mass fingerprinting identified two abundant membrane-associated aphid gut proteins, alanyl aminopeptidase N and sucrase, as "receptors" for lectin binding. PMID:18707000

  9. Lectin domains at the frontiers of plant defense

    PubMed Central

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

    2014-01-01

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

  10. Histological and lectin histochemical studies of the vomeronasal organ of horses.

    PubMed

    Lee, Kwang-Hyup; Park, Changnam; Kim, Jeongtae; Moon, Changjong; Ahn, Meejung; Shin, Taekyun

    2016-08-01

    The morphological characteristics and glycoconjugate composition of the vomeronasal organ (VNO) of the horse was investigated using histological, immunohistochemical, and lectin histochemical methods. The VNO is bilaterally located at the base of the nasal septum, has a tubular structure surrounded by cartilage, and consists of sensory and non-sensory epithelia. Immunohistochemical examination showed that the vomeronasal sensory epithelium (VSE) consisted of receptor cells positive for both olfactory marker protein (OMP) and protein gene product 9.5 (PGP 9.5), supporting cells, and basal cells. VNO receptor cells were positive for G protein Gαi2 (vomeronasal receptor type 1 marker), but not Gαo (vomeronasal receptor type 2 marker). Lectin histochemical studies using 21 biotinylated lectins showed that the free border of the VSE was positive for 20 lectins. The receptor and supporting cells reacted with 16 lectins while the basal cells reacted with 15 lectins, with varying intensities. In the vomeronasal non-sensory epithelium, the free border was positive for 19 lectins. The cilated cells were positive for 17 lectins and the basal cells were positive for 15 lectins. The vomeronasal glands, positioned in the lamina propria, were stained with both periodic acid Schiff (PAS) and alcian blue (pH 2.5). Eighteen lectins stained the acinar cells of the vomeronasal glands with various binding patterns. These findings suggest that horse VNO receptor cells express vomeronasal receptor type 1, and the VNO glands have mucous to seromucous characteristics. Moreover, each lectin differentially binds each cell type in both the VNO sensory and non-sensory epithelia. PMID:27233915

  11. [Comparative lectin histochemical analysis of the duodenal glands in various mammals].

    PubMed

    Iatskovskiĭ, A N; Lutsik, A D

    1991-02-01

    Composition and histotopography of lectin receptors have been studied in 12 species of mammals with various nutritional specialization: carnivorous, phytophagous and omnivorous. In cells of the duodenal glands of the carnivorous and omnivorous receptors to concanavalin A and lentil lectin (D-mannosoglycans ) are absent and they are present in the glands of the phytophagous animals. In cells of some parts of the glands presence of receptors to soya bean lectin (N-acetyl-D-galactosamine++) is the most characteristic sign of the duodenal glands in the carnivorous and phytophagous animals. Together with certain differences, depending on the nutritional way of the animals, specific peculiarities of lectins binding with glandulocytes of the duodenal glands are demonstrated. The data on rearrangement of the lectin receptors are obtained during the process of cellular differentiation. Presence of N-acetyl-D-galactosamine++ remnants-biding soya bean lectin in composition of oligosaccharide++ chains of glycoconjugates is a sign of low differential degree of the glandular cells. In more differentiated cells concealment in oligosaccharide chains of D-galactose remnants (peanut and castor-oil lectins receptors) by L-fucose, N-acetil-D-glucosamin remnants and sialic acid can have place; this is demonstrated as accumulation of receptors to wheat germ and Laburnum anagyroides lectins in the glandular cells. PMID:2053882

  12. 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

  13. Sweet complementarity: the functional pairing of glycans with lectins.

    PubMed

    Gabius, H-J; Manning, J C; Kopitz, J; André, S; Kaltner, H

    2016-05-01

    Carbohydrates establish the third alphabet of life. As part of cellular glycoconjugates, the glycans generate a multitude of signals in a minimum of space. The presence of distinct glycotopes and the glycome diversity are mapped by sugar receptors (antibodies and lectins). Endogenous (tissue) lectins can read the sugar-encoded information and translate it into functional aspects of cell sociology. Illustrated by instructive examples, each glycan has its own ligand properties. Lectins with different folds can converge to target the same epitope, while intrafamily diversification enables functional cooperation and antagonism. The emerging evidence for the concept of a network calls for a detailed fingerprinting. Due to the high degree of plasticity and dynamics of the display of genes for lectins the validity of extrapolations between different organisms of the phylogenetic tree yet is inevitably limited. PMID:26956894

  14. Blocking of Pseudomonas aeruginosa and Chromobacterium violaceum lectins by diverse mammalian milks.

    PubMed

    Zinger-Yosovich, K D; Iluz, D; Sudakevitz, D; Gilboa-Garber, N

    2010-02-01

    Pseudomonas aeruginosa and Chromobacterium violaceum morbid and mortal infections are initiated by bacterial adherence to host-cell receptors via their adhesins, including lectins (which also contribute to bacterial biofilm formation). Pseudomonas aeruginosa produces a galactophilic lectin, PA-IL (LecA), and a fucophilic (Lewis-specific) lectin, PA-IIL (LecB), and C. violaceum produces a fucophilic (H-specific) lectin, CV-IIL. The antibiotic resistance of these bacteria prompted the search for glycosylated receptor-mimicking compounds that would function as glycodecoys for blocking lectin attachment to human cell receptors. Lectins PA-IL and PA-IIL have been shown to be useful for such glycodecoy probing, clearly differentiating between human and cow milks. This article describes their usage, together with CV-IIL and the plant lectin concanavalin A, for comparing the anti-lectin-dependent adhesion potential of diverse mammalian milks. The results show that the diverse milks differ in blocking (hemagglutination inhibition) and differential binding (Western blots) of these lectins. Human milk most strongly inhibited the 3 bacterial lectins (with PA-IIL superiority), followed by alpaca, giraffe, and monkey milks, whereas cow milk was a weak inhibitor. Lectin PA-IL was inhibited strongly by human, followed by alpaca, mare, giraffe, buffalo, and monkey milks, weakly by camel milk, and not at all by rabbit milk. Lectins PA-IIL and CV-IIL were also most sensitive to human milk, followed by alpaca, monkey, giraffe, rabbit, and camel milks but negligibly sensitive to buffalo and mare milks. Plant lectin concanavalinA, which was used as the reference, differed from them in that it was much less sensitive to human milk and was equally as sensitive to cow milk. These results have provided important information on the anti-lectin-dependent adhesion potential of the diverse milks examined. They showed that human followed by alpaca, giraffe, and Rhesus monkey milks efficiently

  15. E-cadherin expression on human carcinoma cell affects trastuzumab-mediated antibody-dependent cellular cytotoxicity through killer cell lectin-like receptor G1 on natural killer cells.

    PubMed

    Yamauchi, Chisako; Fujii, Satoshi; Kimura, Taichi; Kuwata, Takeshi; Wada, Noriaki; Mukai, Hirofumi; Matsumoto, Naoki; Fukayama, Masashi; Ochiai, Atsushi

    2011-05-01

    Trastuzumab is a recombinant antibody drug that is widely used for the treatment of HER2-overexpressing breast carcinoma. Despite encouraging clinical results, many HER2-overexpressing carcinomas are primarily resistant to trastuzumab. We attempted to explain trastuzumab resistance and search for solutions. Since the killer cell lectin-like receptor G1 (KLRG1), an inhibitory receptor expressed on subsets of natural killer (NK) cells recognizes E-cadherin as ligands and may inhibit immune responses by regulating the effector function of NK cells, we used HER2-overexpressing carcinoma cells which were expressing E-cadherin to investigate the role of antibody-dependent cellular cytotoxicity (ADCC) through KLRG1 on NK cells in vitro and vivo. The results indicated that HER2-overexpressing carcinoma cells were killed by trastuzumab-mediated ADCC and the ADCC activity was reflected the degree of E-cadherin expression on carcinoma cells. We found that expression of E-cadherin was shown to be a predictor of response to trastuzumab-based treatment for HER2-overexpressing carcinomas, furthermore, trastuzumab-mediated ADCC was markedly enhanced by KLRG1-negative peripheral blood mononuclear cells (PBMCs(KLRG1(-))). PMID:21387286

  16. 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). PMID:24270074

  17. Glycan and lectin biosensors

    PubMed Central

    Belický, Štefan; Katrlík, Jaroslav

    2016-01-01

    A short description about the importance of glycan biorecognition in physiological (blood cell type) and pathological processes (infections by human and avian influenza viruses) is provided in this review. Glycans are described as much better information storage media, compared to proteins or DNA, due to the extensive variability of glycan structures. Techniques able to detect an exact glycan structure are briefly discussed with the main focus on the application of lectins (glycan-recognising proteins) in the specific analysis of glycans still attached to proteins or cells/viruses. Optical, electrochemical, piezoelectric and micromechanical biosensors with immobilised lectins or glycans able to detect a wide range of analytes including whole cells/viruses are also discussed. PMID:27365034

  18. Glycan and lectin biosensors.

    PubMed

    Belický, Štefan; Katrlík, Jaroslav; Tkáč, Ján

    2016-06-30

    A short description about the importance of glycan biorecognition in physiological (blood cell type) and pathological processes (infections by human and avian influenza viruses) is provided in this review. Glycans are described as much better information storage media, compared to proteins or DNA, due to the extensive variability of glycan structures. Techniques able to detect an exact glycan structure are briefly discussed with the main focus on the application of lectins (glycan-recognising proteins) in the specific analysis of glycans still attached to proteins or cells/viruses. Optical, electrochemical, piezoelectric and micromechanical biosensors with immobilised lectins or glycans able to detect a wide range of analytes including whole cells/viruses are also discussed. PMID:27365034

  19. Weak protein-protein interactions in lectins: the crystal structure of a vegetative lectin from the legume Dolichos biflorus.

    PubMed

    Buts, L; Dao-Thi, M H; Loris, R; Wyns, L; Etzler, M; Hamelryck, T

    2001-05-25

    The legume lectins are widely used as a model system for studying protein-carbohydrate and protein-protein interactions. They exhibit a fascinating quaternary structure variation, which becomes important when they interact with multivalent glycoconjugates, for instance those on cell surfaces. Recently, it has become clear that certain lectins form weakly associated oligomers. This phenomenon may play a role in the regulation of receptor crosslinking and subsequent signal transduction. The crystal structure of DB58, a dimeric lectin from the legume Dolichos biflorus reveals a separate dimer of a previously unobserved type, in addition to a tetramer consisting of two such dimers. This tetramer resembles that formed by DBL, the seed lectin from the same plant. A single amino acid substitution in DB58 affects the conformation and flexibility of a loop in the canonical dimer interface. This disrupts the formation of a stable DBL-like tetramer in solution, but does not prohibit its formation in suitable conditions, which greatly increases the possibilities for the cross-linking of multivalent ligands. The non-canonical DB58 dimer has a buried symmetrical alpha helix, which can be present in the crystal in either of two antiparallel orientations. Two existing structures and datasets for lectins with similar quaternary structures were reconsidered. A central alpha helix could be observed in the soybean lectin, but not in the leucoagglutinating lectin from Phaseolus vulgaris. The relative position and orientation of the carbohydrate-binding sites in the DB58 dimer may affect its ability to crosslink mulitivalent ligands, compared to the other legume lectin dimers. PMID:11491289

  20. Molecular recognition of surface-immobilized carbohydrates by a synthetic lectin

    PubMed Central

    Rauschenberg, Melanie; Fritz, Eva-Corrina; Schulz, Christian; Kaufmann, Tobias

    2014-01-01

    Summary The molecular recognition of carbohydrates and proteins mediates a wide range of physiological processes and the development of synthetic carbohydrate receptors (“synthetic lectins”) constitutes a key advance in biomedical technology. In this article we report a synthetic lectin that selectively binds to carbohydrates immobilized in a molecular monolayer. Inspired by our previous work, we prepared a fluorescently labeled synthetic lectin consisting of a cyclic dimer of the tripeptide Cys-His-Cys, which forms spontaneously by air oxidation of the monomer. Amine-tethered derivatives of N-acetylneuraminic acid (NANA), β-D-galactose, β-D-glucose and α-D-mannose were microcontact printed on epoxide-terminated self-assembled monolayers. Successive prints resulted in simple microarrays of two carbohydrates. The selectivity of the synthetic lectin was investigated by incubation on the immobilized carbohydrates. Selective binding of the synthetic lectin to immobilized NANA and β-D-galactose was observed by fluorescence microscopy. The selectivity and affinity of the synthetic lectin was screened in competition experiments. In addition, the carbohydrate binding of the synthetic lectin was compared with the carbohydrate binding of the lectins concanavalin A and peanut agglutinin. It was found that the printed carbohydrates retain their characteristic selectivity towards the synthetic and natural lectins and that the recognition of synthetic and natural lectins is strictly orthogonal. PMID:24991289

  1. C-type transitions in methyl formate

    NASA Technical Reports Server (NTRS)

    Plummer, Grant M.; Herbst, Eric; De Lucia, Frank C.

    1987-01-01

    Based on previously determined spectral constants for methyl formate in its ground torsional degenerate substate, the frequencies and intensities of forbidden c-type transitions in this molecule, which is represented by a large number of lines in OMC-1, are calculated along with other 'forbidden' transitions labeled x-type. The stronger c-type transitions below 300 GHz with angular momentum quantum number of 30 or less and with upper state rotational energy of 350/cm or less are included in a list of spectral frequencies presented in this paper. Because the c-type transitions borrow intensity from the b-type transitions, the intensities of strongly affected b-type spectra are recalculated and presented.

  2. MMBL proteins: from lectin to bacteriocin.

    PubMed

    Ghequire, Maarten G K; Loris, Remy; De Mot, René

    2012-12-01

    Arguably, bacteriocins deployed in warfare among related bacteria are among the most diverse proteinacous compounds with respect to structure and mode of action. Identification of the first prokaryotic member of the so-called MMBLs (monocot mannose-binding lectins) or GNA (Galanthus nivalis agglutinin) lectin family and discovery of its genus-specific killer activity in the Gram-negative bacteria Pseudomonas and Xanthomonas has added yet another kind of toxin to this group of allelopathic molecules. This novel feature is reminiscent of the protective function, on the basis of antifungal, insecticidal, nematicidal or antiviral activity, assigned to or proposed for several of the eukaryotic MMBL proteins that are ubiquitously distributed among monocot plants, but also occur in some other plants, fish, sponges, amoebae and fungi. Direct bactericidal activity can also be effected by a C-type lectin, but this is a mammalian protein that limits mucosal colonization by Gram-positive bacteria. The presence of two divergent MMBL domains in the novel bacteriocins raises questions about task distribution between modules and the possible role of carbohydrate binding in the specificity of target strain recognition and killing. Notably, bacteriocin activity was also demonstrated for a hybrid MMBL protein with an accessory protease-like domain. This association with one or more additional modules, often with predicted peptide-hydrolysing or -binding activity, suggests that additional bacteriotoxic proteins may be found among the diverse chimaeric MMBL proteins encoded in prokaryotic genomes. A phylogenetic survey of the bacterial MMBL modules reveals a mosaic pattern of strongly diverged sequences, mainly occurring in soil-dwelling and rhizosphere bacteria, which may reflect a trans-kingdom acquisition of the ancestral genes. PMID:23176516

  3. 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

  4. Cytokine production by human epithelial and endothelial cells following exposure to oral viridans streptococci involves lectin interactions between bacteria and cell surface receptors.

    PubMed Central

    Vernier, A; Diab, M; Soell, M; Haan-Archipoff, G; Beretz, A; Wachsmann, D; Klein, J P

    1996-01-01

    In order to examine the possible implication of human epithelial and endothelial cells in the pathogenesis of various diseases associated with oral viridans streptococci, we tested the immunomodulatory effects of 11 representative strains of oral viridans streptococci on human epithelial KB cells and endothelial cells. We then examined the possible role of two major adhesins from oral viridans streptococci, protein I/II and rhamnose-glucose polymers (RGPs), in this process. In this study we demonstrate that oral viridans streptococci are potent stimulators of interleukin-8 (IL-8) production from KB cells and of IL-6 and IL-8 production from endothelial cells. The ability of protein I/II and RGPs to contribute to these effects was then examined. Using biotinylated protein I/IIf and RGPs from Streptococcus mutans OMZ 175, we showed that these adhesins bind to KB and endothelial cells through specific interactions and that the binding of these molecules initiates the release of IL-8 from KB cells and of IL-6 and IL-8 from endothelial cells. These results suggest that protein I/IIf and RGPs play an important role in the interactions between bacteria and KB and endothelial cells in that similar cytokine profiles are obtained when cells are stimulated with bacteria or surface components. We also provide evidence that protein I/IIf binds to and stimulates KB and endothelial cells through lectin interactions and that N-acetyl neuraminic acid (NANA) and fucose present on cell surface glycoproteins may form the recognition site since binding and cytokine release can be inhibited by dispase and periodate treatment of cells and by NANA and fucose. These results demonstrate that oral viridans streptococci, probably by engaging two cell surface adhesins, exert immunomodulatory effects on human KB and endothelial cells. PMID:8757828

  5. Ethanol extract of propolis protects endothelial cells from oxidized low density lipoprotein-induced injury by inhibiting lectin-like oxidized low density lipoprotein receptor-1-mediated oxidative stress.

    PubMed

    Fang, Yongqi; Li, Jinguo; Ding, Mingde; Xu, Xiaoyan; Zhang, Jiajun; Jiao, Peng; Han, Ping; Wang, Jiafu; Yao, Shutong

    2014-12-01

    Lectin-like oxidized low density lipoprotein receptor-1 (LOX-1), as the primary oxidized low-density lipoprotein (ox-LDL) receptor on endothelial cells, plays a crucial role in endothelial injury, which is a driving force in the initiation and development of atherosclerosis. Our previous studies have shown that ethanol extract of propolis (EEP) promotes reverse cholesterol transport and inhibits atherosclerotic lesion development. However, the protective effects of EEP against ox-LDL-induced injury in endothelial cells and the underlying mechanisms are still unknown. This study was designed to test the hypothesis that EEP attenuates ox-LDL-induced endothelial oxidative injury via modulation of LOX-1-mediated oxidative stress. Our results showed that exposure of human umbilical vein endothelial cells (HUVECs) to ox-LDL (100 mg/L) led to the decrease in cell viability and increase in lactate dehydrogenase (LDH) release, caspase-3 activation, and apoptosis, whereas pretreatment with EEP (7.5, 15 and 30 mg/L) protected against such damages in a dose-dependent manner. In addition, EEP mitigated ox-LDL uptake by HUVECs and attenuated ox-LDL-upregulated LOX-1 expression both at the mRNA and protein levels. Moreover, EEP suppressed the ox-LDL-induced oxidative stress as assessed by decreased nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation, reactive oxygen species (ROS), and malondialdehyde (MDA) generation as well as increased antioxidant enzyme activities. Similar results were observed in the anti-LOX-1 antibody or diphenyleneiodonium (DPI)-pretreated HUVECs. These data indicate that EEP may protect HUVECs from ox-LDL-induced injury and that the mechanism at least partially involves its ability to inhibit endothelial LOX-1 upregulation and subsequent oxidative stress. PMID:24962173

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

    PubMed

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

    2015-10-15

    The vast majority of cases of follicular lymphoma (FL), but not normal B cells, acquire N-glycosylation sites in the immunoglobulin variable regions during somatic hypermutation. Glycans added to sites are unusual in terminating at high mannoses. We showed previously that the C-type lectins, dendritic cell-specific intercellular adhesion molecule-3 grabbing non-integrin (DC-SIGN) and mannose receptor, bound to FL surface immunoglobulin (sIg), generating an intracellular Ca(2+) flux. We have now mapped further intracellular pathways activated by DC-SIGN in a range of primary FL cells with detection of phosphorylated ERK1/2, AKT, and PLCγ2. The SYK inhibitor (tamatinib) or the BTK inhibitor (ibrutinib) each blocked phosphorylation. Activation by DC-SIGN occurred in both IgM(+) and IgG(+) cases and led to upregulation of MYC expression, with detection in vivo observed in lymph nodes. Unlike cells of chronic lymphocytic leukemia, FL cells expressed relatively high levels of sIg, unchanged by long-term incubation in vitro, indicating no antigen-mediated downregulation in vivo. In contrast, expression of CXCR4 increased in vitro. Engagement of sIg in FL cells or normal B cells by anti-Ig led to endocytosis in vitro as expected, but DC-SIGN, even when cross-linked, did not lead to significant endocytosis of sIg. These findings indicate that lectin binding generates signals via sIg but does not mediate endocytosis, potentially maintaining a supportive antigen-independent signal in vivo. Location of DC-SIGN in FL tissue revealed high levels in sinusoidlike structures and in some colocalized mononuclear cells, suggesting a role for lectin-expressing cells at this site. PMID:26194765

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

    PubMed

    Gorbushin, Alexander M; Borisova, Elena A

    2015-01-01

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

  8. Probing the cons and pros of lectin-induced immunomodulation: case studies for the mistletoe lectin and galectin-1.

    PubMed

    Gabius, H J

    2001-07-01

    When imagining to monitor animal cells through a microscope with resolution at the molecular level, a salient attribute of their surfaces will be the abundance of glycan chains. They present galactosides at their termini widely extending like tentacles into the extracellular space. Their spatial accessibility and their potential for structural variability endow especially these glycan parts with capacity to act as docking points for molecular sensors (sugar receptors such as lectins). Binding and ligand clustering account for transmission of post-binding signals into the cell interior. The range of triggered activities has turned plant lectins into popular tools in cell biology and immunology. Potential for clinical application has been investigated rigorously only in recent years. As documented in vitro and in vivo for the galactoside-specific mistletoe lectin, its apparent immunomodulatory capacity reflected in upregulation of production of proinflammatory cytokines will not necessarily be clinically favorable but a double-edged sword. In fact, lectin application has been shown to stimulate tumor growth in cell lines, histocultures of human tumors and in two animal models using chemical carcinogenesis or tumor transplantation. When testing immunological effects of the endogenous lectin galectin-1, protection against disorders mediated by activated T cells came up for consideration. Elimination of these cells via CD7-dependent induction of apoptosis, and a shift to the Th2 response by the galectin, are factors to ameliorate disease states. This result encourages further efforts with other galectins. Functional redundancy, synergism, diversity or antagonism among galectins are being explored to understand the actual role of this class of endogenous lectins in inflammation. Regardless of the results of further preclinical testing for galectin-1, these two case studies break new ground in our understanding how glycans as ligands for lectins convey reactivity to

  9. Purification, crystallization and preliminary X-ray analysis of the ligand-binding domain of human lectin-like oxidized low-density lipoprotein receptor 1 (LOX-1)

    SciTech Connect

    Ishigaki, Tomoko; Ohki, Izuru; Oyama, Takuji; Machida, Sachiko; Morikawa, Kousuke; Tate, Shin-ichi

    2005-05-01

    Two different fragments of the ligand-binding domain of LOX-1, the major receptor for oxidized low-density lipoprotein (LDL) on endothelial cells, have been crystallized in different forms. Two different fragments of the ligand-binding domain of LOX-1, the major receptor for oxidized low-density lipoprotein (LDL) on endothelial cells, have been crystallized in different forms. One crystal form contains the disulfide-linked dimer, which is the form of the molecule present on the cell surface; the other contains a monomeric form of the receptor that lacks the cysteine residue necessary to form disulfide-linked homodimers. The crystal of the monomeric ligand-binding domain belongs to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 56.79, b = 67.57, c = 79.02 Å. The crystal of the dimeric form belongs to space group C2, with unit-cell parameters a = 70.86, b = 49.56, c = 76.73 Å, β = 98.59°. Data for the dimeric form of the LOX-1 ligand-binding domain have been collected to 2.4 Å. For the monomeric form of the ligand-binding domain, native, heavy-atom derivative and SeMet-derivative crystals have been obtained; their diffraction data have been measured to 3.0, 2.4 and 1.8 Å resolution, respectively.

  10. Lectin histochemical studies on the vomeronasal organ of the sheep.

    PubMed

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

    2013-01-01

    The vomeronasal organ of sheep was examined using lectin histochemistry in order to compare the types and amounts of the glycoconjugates among various components of the vomeronasal sensory and non-sensory epithelia. In the vomeronasal sensory epithelium, Dolichos biflorus agglutinin (DBA) stained particular cells, located at the same level as the vomeronasal receptor cells, while the distribution, shape and number of the stained cells did not correspond to those of the vomeronasal receptor cells. Datura stramonium lectin (DSL), Concanavalin A (Con A), Phaseolus vulgaris agglutinin-E (PHA-E) and Phaseolus vulgaris agglutinin-L (PHA-L) labeled the basal cells of both vomeronasal sensory and non-sensory epithelia. While, Wheat germ agglutinin (WGA), Succinylated-wheat germ agglutinin (s-WGA), Lycopersicon esculentum lectin (LEL), Solanum tuberosum lectin (STL) and Ricinus communis agglutinin-I (RCA-120) labeled the basal cells of the sensory epithelium, and Bandeiraea simplicifolia lectin-I (BSL-I) stained the basal cells of the non-sensory epithelium, respectively. Seventeen lectins labeled the free border of both vomeronasal sensory and non-sensory epithelia, while Sophora japonica agglutinin (SJA), Jacalin and Pisum sativum agglutinin (PSA) labeled neither free border of the sensory nor that of non-sensory epithelia. The expression pattern of glycoconjugate was similar, but not identical, in the free border between the sensory and non-sensory epithelia. These results indicate that there are dissimilar features in the type and amount of glycoconjugates between the vomeronasal sensory and non-sensory epithelia, and at the same time, among the various cell types either in the vomeronasal sensory or non-sensory epithelium. PMID:23595118

  11. Molecular cloning, characterization and expression analysis of F-type lectin from pearl oyster Pinctada fucata.

    PubMed

    Anju, A; Jeswin, J; Thomas, P C; Vijayan, K K

    2013-07-01

    F-type lectin is an important type of pattern recognition receptor that can recognize and bind carbohydrate moieties on the surface of potential pathogens through its carbohydrate recognition domains (CRDs). This paper reports the cloning of an F-type lectin (designated as pfF-type lectin) from the pearl oyster (Pinctada fucata) using rapid amplification of cDNA ends (RACE) PCR. The full-length cDNA of this pfF-type lectin contains an open reading frame (ORF) of 588 bp coding for196 amino acids. A signal peptide at the N-terminus of the deduced polypeptide was predicted by the signal P program and the cleavage site is located between the positions of Gly(19)and Tyr(20). Conserved domain search at NCBI revealed the pfF-type lectin domain extends from Lys(55)to Val(192). Semi-quantitative analysis in adult tissues showed that the pfF-type lectin mRNA was abundantly expressed in haemocytes and gill and rarely expressed in other tissues tested. After challenge with lipopolysaccharide (LPS), expression of pfF-type lectin mRNA in haemocytes was increased, reaching the highest level at 4 h, then dropping to basal levels at 36 h. These results suggest that F-type lectin play a critical role in the innate immune system of the pearl oyster P. fucata. PMID:23624143

  12. Electron microscopic demonstration of lectin binding sites in the taste buds of the European catfish Silurus glanis (Teleostei).

    PubMed

    Witt, M; Reutter, K

    1990-01-01

    Taste buds in the European catfish Silurus glanis were examined with electron microscopic lectin histochemistry. For detection of carbohydrate residues in sensory cells and adjacent epithelial cells, gold-, ferritin- and biotin-labeled lectins were used. A post-embedding procedure carried out on tissue sections embedded in LR-White was applied to differentiate between the sensory cells: The lectins from Helix pomatia (HPA) and Triticum vulgare (WGA) bound to N-acetyl-galactosamine and to N-acetylglucosamine residues occurring especially in vesicles of dark sensory cells. This indicates a secretory function of these cells. Most light sensory cells--with some exceptions, probably immature cells--, are HPA-negative. The mucus of the receptor field and at the top of the adjacent epithelial cells was strongly HPA-positive. Pre-embedding studies were performed in order to obtain information about the reaction of the mucus with lectins under supravital conditions. The mucus of the taste bud receptor field exhibited intensive binding to WGA, but not to the other lectins tested. Most lectins bound predominantly to the surface mucus of the nonsensory epithelium and to the marginal cells close to the receptor field. The strong lectin binding to mucins and the relatively weak lectin binding to cell surface membranes in pre-embedding studies suggest that the mucus possibly serves as a barrier which is passed selectively only by a small amount of lectins or lectin-carbohydrate complexes. Lectin-carbohydrate interactions may play a role in recognition phenomena on the plasmalemmata of the taste bud sensory cells. Recognition processes directed to bacteria or viruses should be considered as well. PMID:2279957

  13. Use of lectins in immunohematology

    PubMed Central

    Gorakshakar, Ajit C.; Ghosh, Kanjaksha

    2016-01-01

    Lectins are carbohydrate binding proteins present in seeds of many plants, especially corals and beans, in fungi and bacteria, and in animals. Apart from their hemagglutinating property, a wide range of functions have been attributed to them. Their importance in the area of immunohematology is immense. They are used to detect specific red cell antigens, to activate different types of lymphocytes, in order to resolve problems related to polyagglutination and so on. The introduction of advanced biotechnological tools generates new opportunities to exploit the properties of lectins, which were not used earlier. Stem cell research is a very important area in transplant medicine. Certain lectins detect surface markers of stem cell. Hence, they are used to understand the developmental biology of stem cells. The role of various lectins in the areas of transfusion and transplant medicine is discussed in detail in this review. PMID:27011665

  14. A review of fish lectins.

    PubMed

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

    2015-01-01

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

  15. Structure of the Lectin Mannose 6-Phosphate Receptor Homology (MRH) Domain of Glucosidase II, an Enzyme That Regulates Glycoprotein Folding Quality Control in the Endoplasmic Reticulum*

    PubMed Central

    Olson, Linda J.; Orsi, Ramiro; Alculumbre, Solana G.; Peterson, Francis C.; Stigliano, Ivan D.; Parodi, Armando J.; D'Alessio, Cecilia; Dahms, Nancy M.

    2013-01-01

    Here we report for the first time the three-dimensional structure of a mannose 6-phosphate receptor homology (MRH) domain present in a protein with enzymatic activity, glucosidase II (GII). GII is involved in glycoprotein folding in the endoplasmic reticulum. GII removes the two innermost glucose residues from the Glc3Man9GlcNAc2 transferred to nascent proteins and the glucose added by UDP-Glc:glycoprotein glucosyltransferase. GII is composed of a catalytic GIIα subunit and a regulatory GIIβ subunit. GIIβ participates in the endoplasmic reticulum localization of GIIα and mediates in vivo enhancement of N-glycan trimming by GII through its C-terminal MRH domain. We determined the structure of a functional GIIβ MRH domain by NMR spectroscopy. It adopts a β-barrel fold similar to that of other MRH domains, but its binding pocket is the most shallow known to date as it accommodates a single mannose residue. In addition, we identified a conserved residue outside the binding pocket (Trp-409) present in GIIβ but not in other MRHs that influences GII glucose trimming activity. PMID:23609449

  16. Platform Synthetic Lectins for Divalent Carbohydrate Recognition in Water.

    PubMed

    Carter, Tom S; Mooibroek, Tiddo J; Stewart, Patrick F N; Crump, Matthew P; Galan, M Carmen; Davis, Anthony P

    2016-08-01

    Biomimetic carbohydrate receptors ("synthetic lectins") have potential as agents for biological research and medicine. However, although effective strategies are available for "all-equatorial" carbohydrates (glucose, etc.), the recognition of other types of saccharide under natural (aqueous) conditions is less well developed. Herein we report a new approach based on a pyrene platform with polar arches extending from aryl substituents. The receptors are compatible with axially substituted carbohydrates, and also feature two identical binding sites, thus mimicking the multivalency observed for natural lectins. A variant with negative charges forms 1:2 host/guest complexes with aminosugars, with K1 >3000 m(-1) for axially substituted mannosamine, whereas a positively charged version binds the important α-sialyl unit with K1 ≈1300 m(-1) . PMID:27312071

  17. Noncovalent PEGylation via Lectin-Glycopolymer Interactions.

    PubMed

    Antonik, Paweł M; Eissa, Ahmed M; Round, Adam R; Cameron, Neil R; Crowley, Peter B

    2016-08-01

    PEGylation, the covalent modification of proteins with polyethylene glycol, is an abundantly used technique to improve the pharmacokinetics of therapeutic proteins. The drawback with this methodology is that the covalently attached PEG can impede the biological activity (e.g., reduced receptor-binding capacity). Protein therapeutics with "disposable" PEG modifiers have potential advantages over the current technology. Here, we show that a protein-polymer "Medusa complex" is formed by the combination of a hexavalent lectin with a glycopolymer. Using NMR spectroscopy, small-angle X-ray scattering (SAXS), size exclusion chromatography, and native gel electrophoresis it was demonstrated that the fucose-binding lectin RSL and a fucose-capped polyethylene glycol (Fuc-PEG) form a multimeric assembly. All of the experimental methods provided evidence of noncovalent PEGylation with a concomitant increase in molecular mass and hydrodynamic radius. The affinity of the protein-polymer complex was determined by ITC and competition experiments to be in the micromolar range, suggesting that such systems have potential biomedical applications. PMID:27403588

  18. The Macrophage Galactose-Type Lectin-1 (MGL1) Recognizes Taenia crassiceps Antigens, Triggers Intracellular Signaling, and Is Critical for Resistance to This Infection

    PubMed Central

    Montero-Barrera, Daniel; Valderrama-Carvajal, Héctor; Terrazas, César A.; Rojas-Hernández, Saúl; Ledesma-Soto, Yadira; Vera-Arias, Laura; Carrasco-Yépez, Maricela; Gómez-García, Lorena; Martínez-Saucedo, Diana; Becerra-Díaz, Mireya; Terrazas, Luis I.

    2015-01-01

    C-type lectins are multifunctional sugar-binding molecules expressed on dendritic cells (DCs) and macrophages that internalize antigens for processing and presentation. Macrophage galactose-type lectin 1 (MGL1) recognizes glycoconjugates expressing Lewis X structures which contain galactose residues, and it is selectively expressed on immature DCs and macrophages. Helminth parasites contain large amounts of glycosylated components, which play a role in the immune regulation induced by such infections. Macrophages from MGL1−/− mice showed less binding ability toward parasite antigens than their wild-type (WT) counterparts. Exposure of WT macrophages to T. crassiceps antigens triggered tyrosine phosphorylation signaling activity, which was diminished in MGL1−/− macrophages. Following T. crassiceps infection, MGL1−/− mice failed to produce significant levels of inflammatory cytokines early in the infection compared to WT mice. In contrast, MGL1−/− mice developed a Th2-dominant immune response that was associated with significantly higher parasite loads, whereas WT mice were resistant. Flow cytometry and RT-PCR analyses showed overexpression of the mannose receptors, IL-4Rα, PDL2, arginase-1, Ym1, and RELM-α on MGL1−/− macrophages. These studies indicate that MGL1 is involved in T. crassiceps recognition and subsequent innate immune activation and resistance. PMID:25664320

  19. IgG4 anti-phospholipase A2 receptor might activate lectin and alternative complement pathway meanwhile in idiopathic membranous nephropathy: an inspiration from a cross-sectional study.

    PubMed

    Yang, Yang; Wang, Chao; Jin, Liping; He, Fagui; Li, Changchun; Gao, Qingman; Chen, Guanglei; He, Zhijun; Song, Minghui; Zhou, Zhuliang; Shan, Fujun; Qi, Ka; Ma, Lu

    2016-08-01

    The deposition of IgG4 of antibodies against phospholipase A2 receptor (anti-PLA2R) is predominating in the kidneys of patients with idiopathic membranous nephropathy, while its predictive value has not been determined. It was a retrospective study, and 438 patients were included. Serum samples of two time points [before intervention (baseline) and after 1.5-year treatment (endpoint)] were detected for total and IgG4 anti-PLA2R. IgG4 <0.26 RU/mL or total <20 RU/mL was considered as seronegativity. Bi-positivity/bi-negativity was defined when patients'antibodies were found positive or negative both at the baseline and endpoint. Completed remission (CR) was a major clinical outcome. A series of complement ingredients (MASP-1/2, MBL, C3a, C5a, Factor B, Ba, Bb and C5b-9) were measured in the patients of bi-positivity and bi-negativity: (1) meta-analysis based on six papers conducted seropositivity of anti-PLA2R was a useful predictor for achieving CR, but there was a high heterogeneity; (2) there was significant correlation between the baseline and decrease in IgG4 subclass and the achievement of CR; (3) bi-negativity of IgG4 has a high accuracy of predicting CR compared with total antibodies; (4) in patients of bi-positivity, those achieving CR showed lower MASP-1/2, MBL, C3a, C5a, FB, Ba and Bb than patients failing to achieve CR; (5) the titers of endpoint and decrease in Ba and Bb were associated with improvement of 24 h-UP in those of bi-positivity; and (6) the decrease in Ba was a significant factor for achieving CR in those of bi-positivity. Continuous IgG4 negativity was a useful tool to predict the achievement of CR; however, in patients of continuous IgG4 positivity, those with lower activation of lectin and alternative pathways would still more probably achieve CR. PMID:26837241

  20. Antinutritional properties of plant lectins.

    PubMed

    Vasconcelos, Ilka M; Oliveira, José Tadeu A

    2004-09-15

    Lectins are carbohydrate binding (glyco)proteins which are ubiquitous in nature. In plants, they are distributed in various families and hence ingested daily in appreciable amounts by both humans and animals. One of the most nutritionally important features of plant lectins is their ability to survive digestion by the gastrointestinal tract of consumers. This allows the lectins to bind to membrane glycosyl groups of the cells lining the digestive tract. As a result of this interaction a series of harmful local and systemic reactions are triggered placing this class of molecules as antinutritive and/or toxic substances. Locally, they can affect the turnover and loss of gut epithelial cells, damage the luminal membranes of the epithelium, interfere with nutrient digestion and absorption, stimulate shifts in the bacterial flora and modulate the immune state of the digestive tract. Systemically, they can disrupt lipid, carbohydrate and protein metabolism, promote enlargement and/or atrophy of key internal organs and tissues and alter the hormonal and immunological status. At high intakes, lectins can seriously threaten the growth and health of consuming animals. They are also detrimental to numerous insect pests of crop plants although less is presently known about their insecticidal mechanisms of action. This current review surveys the recent knowledge on the antinutritional/toxic effects of plant lectins on higher animals and insects. PMID:15302522

  1. Mincle suppresses Toll-like receptor 4 activation.

    PubMed

    Greco, Stephanie H; Mahmood, Syed Kashif; Vahle, Anne-Kristin; Ochi, Atsuo; Batel, Jennifer; Deutsch, Michael; Barilla, Rocky; Seifert, Lena; Pachter, H Leon; Daley, Donnele; Torres-Hernandez, Alejandro; Hundeyin, Mautin; Mani, Vishnu R; Miller, George

    2016-07-01

    Regulation of Toll-like receptor responses is critical for limiting tissue injury and autoimmunity in both sepsis and sterile inflammation. We found that Mincle, a C-type lectin receptor, regulates proinflammatory Toll-like receptor 4 signaling. Specifically, Mincle ligation diminishes Toll-like receptor 4-mediated inflammation, whereas Mincle deletion or knockdown results in marked hyperresponsiveness to lipopolysaccharide in vitro, as well as overwhelming lipopolysaccharide-mediated inflammation in vivo. Mechanistically, Mincle deletion does not up-regulate Toll-like receptor 4 expression or reduce interleukin 10 production after Toll-like receptor 4 ligation; however, Mincle deletion decreases production of the p38 mitogen-activated protein kinase-dependent inhibitory intermediate suppressor of cytokine signaling 1, A20, and ABIN3 and increases expression of the Toll-like receptor 4 coreceptor CD14. Blockade of CD14 mitigates the increased sensitivity of Mincle(-/-) leukocytes to Toll-like receptor 4 ligation. Collectively, we describe a major role for Mincle in suppressing Toll-like receptor 4 responses and implicate its importance in nonmycobacterial models of inflammation. PMID:26747838

  2. A novel bifunctional hybrid with marine bacterium alkaline phosphatase and Far Eastern holothurian mannan-binding lectin activities.

    PubMed

    Balabanova, Larissa; Golotin, Vasily; Kovalchuk, Svetlana; Bulgakov, Alexander; Likhatskaya, Galina; Son, Oksana; Rasskazov, Valery

    2014-01-01

    A fusion between the genes encoding the marine bacterium Cobetia marina alkaline phosphatase (CmAP) and Far Eastern holothurian Apostichopus japonicus mannan-binding C-type lectin (MBL-AJ) was performed. Expression of the fusion gene in E. coli cells resulted in yield of soluble recombinant chimeric protein CmAP/MBL-AJ with the high alkaline phosphatase activity and specificity of the lectin MBL-AJ. The bifunctional hybrid CmAP/MBL-AJ was produced as a dimer with the molecular mass of 200 kDa. The CmAP/MBL-AJ dimer model showed the two-subunit lectin part that is associated with two molecules of alkaline phosphatase functioning independently from each other. The highly active CmAP label genetically linked to MBL-AJ has advantaged the lectin-binding assay in its sensitivity and time. The double substitution A156N/F159K in the lectin domain of CmAP/MBL-AJ has enhanced its lectin activity by 25 ± 5%. The bifunctional hybrid holothurian's lectin could be promising tool for developing non-invasive methods for biological markers assessment, particularly for improving the MBL-AJ-based method for early detection of a malignant condition in cervical specimens. PMID:25397876

  3. A Novel Bifunctional Hybrid with Marine Bacterium Alkaline Phosphatase and Far Eastern Holothurian Mannan-Binding Lectin Activities

    PubMed Central

    Balabanova, Larissa; Golotin, Vasily; Kovalchuk, Svetlana; Bulgakov, Alexander; Likhatskaya, Galina; Son, Oksana; Rasskazov, Valery

    2014-01-01

    A fusion between the genes encoding the marine bacterium Cobetia marina alkaline phosphatase (CmAP) and Far Eastern holothurian Apostichopus japonicus mannan-binding C-type lectin (MBL-AJ) was performed. Expression of the fusion gene in E. coli cells resulted in yield of soluble recombinant chimeric protein CmAP/MBL-AJ with the high alkaline phosphatase activity and specificity of the lectin MBL-AJ. The bifunctional hybrid CmAP/MBL-AJ was produced as a dimer with the molecular mass of 200 kDa. The CmAP/MBL-AJ dimer model showed the two-subunit lectin part that is associated with two molecules of alkaline phosphatase functioning independently from each other. The highly active CmAP label genetically linked to MBL-AJ has advantaged the lectin-binding assay in its sensitivity and time. The double substitution A156N/F159K in the lectin domain of CmAP/MBL-AJ has enhanced its lectin activity by 25±5%. The bifunctional hybrid holothurian's lectin could be promising tool for developing non-invasive methods for biological markers assessment, particularly for improving the MBL-AJ-based method for early detection of a malignant condition in cervical specimens. PMID:25397876

  4. Density variant glycan microarray for evaluating cross-linking of mucin-like glycoconjugates by lectins.

    PubMed

    Godula, Kamil; Bertozzi, Carolyn R

    2012-09-26

    Interactions of mucin glycoproteins with cognate receptors are dictated by the structures and spatial organization of glycans that decorate the mucin polypeptide backbone. The glycan-binding proteins, or lectins, that interact with mucins are often oligomeric receptors with multiple ligand binding domains. In this work, we employed a microarray platform comprising synthetic glycopolymers that emulate natural mucins arrayed at different surface densities to evaluate how glycan valency and spatial separation affect the preferential binding mode of a particular lectin. We evaluated a panel of four lectins (Soybean agglutinin (SBA), Wisteria floribunda lectin (WFL), Vicia villosa-B-4 agglutinin (VVA), and Helix pomatia agglutin (HPA)) with specificity for α-N-acetylgalactosamine (α-GalNAc), an epitope displayed on mucins overexpressed in many adenocarcinomas. While these lectins possess the ability to agglutinate A(1)-blood cells carrying the α-GalNAc epitope and cross-link low valency glycoconjugates, only SBA showed a tendency to form intermolecular cross-links among the arrayed polyvalent mucin mimetics. These results suggest that glycopolymer microarrays can reveal discrete higher-order binding preferences beyond the recognition of individual glycan epitopes. Our findings indicate that glycan valency can set thresholds for cross-linking by lectins. More broadly, well-defined synthetic glycopolymers enable the integration of glycoconjugate structural and spatial diversity in a single microarray screening platform. PMID:22967056

  5. Pattern recognition receptors in antifungal immunity.

    PubMed

    Plato, Anthony; Hardison, Sarah E; Brown, Gordon D

    2015-03-01

    Receptors of the innate immune system are the first line of defence against infection, being able to recognise and initiate an inflammatory response to invading microorganisms. The Toll-like (TLR), NOD-like (NLR), RIG-I-like (RLR) and C-type lectin-like receptors (CLR) are four receptor families that contribute to the recognition of a vast range of species, including fungi. Many of these pattern recognition receptors (PRRs) are able to initiate innate immunity and polarise adaptive responses upon the recognition of fungal cell wall components and other conserved molecular patterns, including fungal nucleic acids. These receptors induce effective mechanisms of fungal clearance in normal hosts, but medical interventions, immunosuppression or genetic predisposition can lead to susceptibility to fungal infections. In this review, we highlight the importance of PRRs in fungal infection, specifically CLRs, which are the major PRR involved. We will describe specific PRRs in detail, the importance of receptor collaboration in fungal recognition and clearance, and describe how genetic aberrations in PRRs can contribute to disease pathology. PMID:25420452

  6. C-Type Natriuretic Peptide Analog as Therapy for Achondroplasia.

    PubMed

    Legeai-Mallet, Laurence

    2016-01-01

    Fibroblast growth factor receptor 3 (FGFR3) is an important regulator of bone formation. Gain-of-function mutations in the FGFR3 gene result in chondrodysplasias which include achondroplasia (ACH), the most common form of dwarfism, in which skull, appendicular and axial skeletons are affected. The skeletal phenotype of patients with ACH showed defective proliferation and differentiation of the chondrocytes in the growth plate cartilage. Both endochondral and membranous ossification processes are disrupted during development. At cellular level, Fgfr3 mutations induce increased phosphorylation of the tyrosine kinase receptor FGFR3, which correlate with an enhanced activation of its downstream signaling pathways. Potential therapeutic strategies have emerged for ACH. Several preclinical studies have been conducted such as the C-type natriuretic peptide (CNP) analog (BMN111), intermittent parathyroid hormone injections, soluble FGFR3 therapy, and meclozine and statin treatments. Among the putative targets to antagonize FGFR3 signaling, CNP (or BMN111) is one of the most promising strategies. BMN111 acts as a key regulator of longitudinal bone growth by downregulating the mitogen-activated protein kinase pathway, which is activated as a result of a FGFR3 gain-of-function mutation. Preclinical studies showed that BMN111 treatment led to a large improvement in skeletal parameters in Fgfr3Y367C/+ mice mimicking ACH. In 2014, a clinical trial (phase 2) of BMN111 in pediatric patients with ACH has started. This first clinical trial marks the first big step towards real treatment for these patients. PMID:26684019

  7. Role of the lectin complement pathway in kidney transplantation.

    PubMed

    Farrar, Conrad A; Zhou, Wuding; Sacks, Steven H

    2016-10-01

    In the last 15 years two major advances in the role of complement in the kidney transplant have come about. The first is that ischaemia reperfusion injury and its profound effect on transplant outcome is dependent on the terminal product of complement activation, C5b-9. The second key observation relates to the function of the small biologically active fragments C3a and C5a released by complement activation in increasing antigen presentation and priming the T cell response that results in transplant rejection. In both cases local synthesis of C3 principally by the renal tubule cells plays an essential role that overshadows the role of the circulating pool of C3 generated largely by hepatocyte synthesis. More recent efforts have investigated the molecules expressed by renal tissue that can trigger complement activation. These have revealed a prominent effect of collectin-11 (CL-11), a soluble C-type lectin that is expressed in renal tissue and aligns with its major ligand L-fucose at sites of complement activation following ischaemic stress. Biochemical studies have shown that interaction between CL-11 and L-fucose results in complement activation by the lectin complement pathway, precisely targeting the innate immune response to the ischaemic tubule surface. Therapeutic approaches to reduce inflammatory and immune stimulation in ischaemic kidney have so far targeted C3 or its activation products and several are in clinical trials. The finding that lectin-fucose interaction is an important trigger of lectin pathway complement activation within the donor organ opens up further therapeutic targets where intervention could protect the donor kidney against complement. PMID:27286717

  8. 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. PMID:23972202

  9. Pattern recognition receptors and central nervous system repair

    PubMed Central

    Kigerl, Kristina A.; de Rivero Vaccari, Juan Pablo; Dietrich, W. Dalton

    2016-01-01

    Pattern recognition receptors (PRRs) are part of the innate immune response and were originally discovered for their role in recognizing pathogens by ligating specific pathogen associated molecular patterns (PAMPs) expressed by microbes. Now the role of PRRs in sterile inflammation is also appreciated, responding to endogenous stimuli referred to as “damage associated molecular patterns” (DAMPs) instead of PAMPs. The main families of PRRs include Toll-like receptors (TLRs), Nod-like receptors (NLRs), RIG-like receptors (RLRs), AIM2-like receptors (ALRs), and C-type lectin receptors. Broad expression of these PRRs in the CNS and the release of DAMPs in and around sites of injury suggest an important role for these receptor families in mediating post-injury inflammation. Considerable data now show that PRRs are among the first responders to CNS injury and activation of these receptors on microglia, neurons, and astrocytes triggers an innate immune response in the brain and spinal cord. Here we discuss how the various PRR families are activated and can influence injury and repair processes following CNS injury. PMID:25017883

  10. Macrophage Galactose-Type Lectin-1 Deficiency Is Associated with Increased Neutrophilia and Hyperinflammation in Gram-Negative Pneumonia.

    PubMed

    Jondle, Christopher N; Sharma, Atul; Simonson, Tanner J; Larson, Benjamin; Mishra, Bibhuti B; Sharma, Jyotika

    2016-04-01

    C-type lectin receptors (CLRs), the carbohydrate-recognizing molecules, orchestrate host immune response in homeostasis and in inflammation. In the present study we examined the function of macrophage galactose-type lectin-1 (MGL1), a mammalian CLR, in pneumonic sepsis, a deadly immune disorder frequently associated with a nonresolving hyperinflammation. In a murine model of pneumonic sepsis using pulmonary infection with Klebsiella pneumoniae, the expression of MGL1 was upregulated in the lungs of K. pneumoniae-infected mice, and the deficiency of this CLR in MGL1(-/-) mice resulted in significantly increased mortality to infection than in the MGL1-sufficient wild-type mice, despite a similar bacterial burden. The phagocytic cells from MGL1(-/-) mice did not exhibit any defects in bacterial uptake and intracellular killing and were fully competent in neutrophil extracellular trap formation, a recently identified extracellular killing modality of neutrophils. Instead, the increased susceptibility of MGL1(-/-) mice seemed to correlate with severe lung pathology, indicating that MGL1 is required for resolution of pulmonary inflammation. Indeed, the MGL1(-/-) mice exhibited a hyperinflammatory response, massive pulmonary neutrophilia, and an increase in neutrophil-associated immune mediators. Concomitantly, MGL1-deficient neutrophils exhibited an increased influx in pneumonic lungs of K. pneumoniae-infected mice. Taken together, these results show a previously undetermined role of MGL1 in controlling neutrophilia during pneumonic infection, thus playing an important role in resolution of inflammation. To our knowledge, this is the first study depicting a protective function of MGL1 in an acute pneumonic bacterial infection. PMID:26912318

  11. Mouse Macrophage Galactose-type Lectin (mMGL) is Critical for Host Resistance against Trypanosoma cruzi Infection

    PubMed Central

    Vázquez, Alicia; de Dios Ruiz-Rosado, Juan; Terrazas, Luis I.; Juárez, Imelda; Gomez-Garcia, Lorena; Calleja, Elsa; Camacho, Griselda; Chávez, Ana; Romero, Miriam; Rodriguez, Tonathiu; Espinoza, Bertha; Rodriguez-Sosa, Miriam

    2014-01-01

    The C-type lectin receptor mMGL is expressed exclusively by myeloid antigen presenting cells (APC) such as dendritic cells (DC) and macrophages (Mφ), and it mediates binding to glycoproteins carrying terminal galactose and α- or β-N-acetylgalactosamine (Gal/GalNAc) residues. Trypanosoma cruzi (T. cruzi) expresses large amounts of mucin (TcMUC)-like glycoproteins. Here, we show by lectin-blot that galactose moieties are also expressed on the surface of T. cruzi. Male mMGL knockout (-/-) and wild-type (WT) C57BL/6 mice were infected intraperitoneally with 104 T. cruzi trypomastigotes (Queretaro strain). Following T. cruzi infection, mMGL-/- mice developed higher parasitemia and higher mortality rates compared with WT mice. Although hearts from T. cruzi-infected WT mice presented few amastigote nests, mMGL-/- mice displayed higher numbers of amastigote nests. Compared with WT, Mφ from mMGL-/- mice had low production of nitric oxide (NO), interleukin (IL)-12 and tumor necrosis factor (TNF)-α in response to soluble T. cruzi antigens (TcAg). Interestingly, upon in vitro T. cruzi infection, mMGL-/- Mφ expressed lower levels of MHC-II and TLR-4 and harbored higher numbers of parasites, even when mMGL-/- Mφ were previously primed with IFN-γ or LPS/IFN-γ. These data suggest that mMGL plays an important role during T. cruzi infection, is required for optimal Mφ activation, and may synergize with TLR-4-induced pathways to produce TNF-α, IL-1β and NO during the early phase of infection. PMID:25170304

  12. Cflec-5, a pattern recognition receptor in scallop Chlamys farreri agglutinating yeast Pichia pastoris.

    PubMed

    Zhang, Huan; Kong, Pengfei; Wang, Lingling; Zhou, Zhi; Yang, Jialong; Zhang, Ying; Qiu, Limei; Song, Linsheng

    2010-07-01

    C-type lectins are a superfamily of carbohydrate-recognition proteins which play crucial roles as pattern recognition receptors (PRRs) in the innate immunity. In this study, the full-length cDNA of a C-type lectin was cloned from scallop Chlamys farreri (designated as Cflec-5) by expression sequence tag (EST) analysis and rapid amplification of cDNA ends (RACE) approach. The full-length cDNA of Cflec-5 was of 1412 bp. The open reading frame encoded a polypeptide of 153 amino acids, including a signal sequence and a conserved carbohydrate-recognition domain with the EPN motif determining the mannose-binding specificity. The deduced amino acid sequence of Cflec-5 showed high similarity to members of C-type lectin superfamily. The quantitative real-time PCR was performed to investigate the tissue distribution of Cflec-5 mRNA and its temporal expression profiles in hemocytes post pathogen-associated molecular patterns (PAMPs) stimulation. In healthy scallops, the Cflec-5 mRNA was mainly detected in gill and mantle, and marginally in other tissues. The mRNA expression of Cflec-5 could be significantly induced by lipopolysaccharide (LPS) and glucan stimulation and reached the maximum level at 6 h and 12 h, respectively. But its expression level did not change significantly during peptidoglycan (PGN) stimulation. The function of Cflec-5 was investigated by recombination and expression of the cDNA fragment encoding its mature peptide in Escherichia coli Rosetta Gami (DE3). The recombinant Cflec-5 agglutinated Pichia pastoris in a calcium-independent way. The agglutinating activity could be inhibited by d-mannose, LPS and glucan, but not by d-galactose or PGN. These results collectively suggested that Cflec-5 was involved in the innate immune response of scallops and might contribute to nonself-recognition through its interaction with various PAMPs. PMID:20211738

  13. Multivalent Carbohydrate-Lectin Interactions: How Synthetic Chemistry Enables Insights into Nanometric Recognition.

    PubMed

    Roy, René; Murphy, Paul V; Gabius, Hans-Joachim

    2016-01-01

    Glycan recognition by sugar receptors (lectins) is intimately involved in many aspects of cell physiology. However, the factors explaining the exquisite selectivity of their functional pairing are not yet fully understood. Studies toward this aim will also help appraise the potential for lectin-directed drug design. With the network of adhesion/growth-regulatory galectins as therapeutic targets, the strategy to recruit synthetic chemistry to systematically elucidate structure-activity relationships is outlined, from monovalent compounds to glyco-clusters and glycodendrimers to biomimetic surfaces. The versatility of the synthetic procedures enables to take examining structural and spatial parameters, alone and in combination, to its limits, for example with the aim to produce inhibitors for distinct galectin(s) that exhibit minimal reactivity to other members of this group. Shaping spatial architectures similar to glycoconjugate aggregates, microdomains or vesicles provides attractive tools to disclose the often still hidden significance of nanometric aspects of the different modes of lectin design (sequence divergence at the lectin site, differences of spatial type of lectin-site presentation). Of note, testing the effectors alone or in combination simulating (patho)physiological conditions, is sure to bring about new insights into the cooperation between lectins and the regulation of their activity. PMID:27187342

  14. Endothelial C-type natriuretic peptide maintains vascular homeostasis

    PubMed Central

    Moyes, Amie J.; Khambata, Rayomand S.; Villar, Inmaculada; Bubb, Kristen J.; Baliga, Reshma S.; Lumsden, Natalie G.; Xiao, Fang; Gane, Paul J.; Rebstock, Anne-Sophie; Worthington, Roberta J.; Simone, Michela I.; Mota, Filipa; Rivilla, Fernando; Vallejo, Susana; Peiró, Concepción; Sánchez Ferrer, Carlos F.; Djordjevic, Snezana; Caulfield, Mark J.; MacAllister, Raymond J.; Selwood, David L.; Ahluwalia, Amrita; Hobbs, Adrian J.

    2014-01-01

    The endothelium plays a fundamental role in maintaining vascular homeostasis by releasing factors that regulate local blood flow, systemic blood pressure, and the reactivity of leukocytes and platelets. Accordingly, endothelial dysfunction underpins many cardiovascular diseases, including hypertension, myocardial infarction, and stroke. Herein, we evaluated mice with endothelial-specific deletion of Nppc, which encodes C-type natriuretic peptide (CNP), and determined that this mediator is essential for multiple aspects of vascular regulation. Specifically, disruption of CNP leads to endothelial dysfunction, hypertension, atherogenesis, and aneurysm. Moreover, we identified natriuretic peptide receptor–C (NPR-C) as the cognate receptor that primarily underlies CNP-dependent vasoprotective functions and developed small-molecule NPR-C agonists to target this pathway. Administration of NPR-C agonists promotes a vasorelaxation of isolated resistance arteries and a reduction in blood pressure in wild-type animals that is diminished in mice lacking NPR-C. This work provides a mechanistic explanation for genome-wide association studies that have linked the NPR-C (Npr3) locus with hypertension by demonstrating the importance of CNP/NPR-C signaling in preserving vascular homoeostasis. Furthermore, these results suggest that the CNP/NPR-C pathway has potential as a disease-modifying therapeutic target for cardiovascular disorders. PMID:25105365

  15. 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.

  16. 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

  17. 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

  18. Molecular and biological characterization of a mannan-binding lectin from the holothurian Apostichopus japonicus.

    PubMed

    Bulgakov, Aleksandr A; Eliseikina, Marina G; Petrova, Irina Yu; Nazarenko, Evgeny L; Kovalchuk, Svetlana N; Kozhemyako, Valery B; Rasskazov, Valery A

    2007-12-01

    To elucidate the origin and evolution of mannan-binding lectins (MBL), a new C-type lectin (CTL) specific for high-mannose glycans (MBL-AJ) was isolated from the coelomic plasma of the holothurian Apostichopus japonicus. MBL-AJ has oligomeric forms with identical 17-kDa subunits on SDS-PAGE. Among natural ligands, lectin hemagglutination activity was competitively inhibited by extracellular low-branched, but not high-branched, alpha-D-mannans isolated from marine halophilic bacteria and composed of alpha-1,2 and alpha-1,6 linked D-mannose residues. This suggests that the lectin interacts with backbone or inner side chain mannose residues, but not with terminal ones. The activity of the lectin was Ca(2+)-, pH-, and temperature-dependent. MBL-AJ cDNA was cloned from a holothurian coelomocyte cDNA library. The subunit of the mature protein has 159 amino acids and a single carbohydrate-recognition domain (CRD) of CTL. CRD contains a Glu-Pro-Asp amino acid sequence (EPN-motif) conserved for all known MBLs. A monospecific polyclonal antibody against MBL-AJ was obtained using the 34-kDa lectin dimer as an immunogen. The MBL-AJ has demonstrated immunochemical identity to the earlier isolated mannan-binding CTL from another holothurian, Cucumaria japonica. But a more interesting finding was cross-reactivity of MBL-AJ and human serum MBL detected by the antibody against MBL-AJ. Taking into consideration such MBL-AJ peculiarities as its carbohydrate specificity, the presence of a conserved region forming the mannose-binding site, common antigenic determinants with human MBL, and participation in defense reactions, it is possible that MBL-AJ belongs to the family of evolutionary conserved mannan-binding proteins. PMID:17890508

  19. Lectin-based Isolation and Culture of Mouse Embryonic Motoneurons

    PubMed Central

    Conrad, Rebecca; Jablonka, Sibylle; Sczepan, Teresa; Sendtner, Michael; Wiese, Stefan; Klausmeyer, Alice

    2011-01-01

    Spinal motoneurons develop towards postmitotic stages through early embryonic nervous system development and subsequently grow out dendrites and axons. Neuroepithelial cells of the neural tube that express Nkx6.1 are the unique precursor cells for spinal motoneurons1. Though postmitotic motoneurons move towards their final position and organize themselves into columns along the spinal tract2,3. More than 90% of all these differentiated and positioned motoneurons express the transcription factors Islet 1/2. They innervate the muscles of the limbs as well as those of the body and the inner organs. Among others, motoneurons typically express the high affinity receptors for brain derived neurotrophic factor (BDNF) and Neurotrophin-3 (NT-3), the tropomyosin-related kinase B and C (TrkB, TrkC). They do not express the tropomyosin-related kinase A (TrkA)4. Beside the two high affinity receptors, motoneurons do express the low affinity neurotrophin receptor p75NTR. The p75NTR can bind all neurotrophins with similar but lower affinity to all neurotrophins than the high affinity receptors would bind the mature neurotrophins. Within the embryonic spinal cord, the p75NTR is exclusively expressed by the spinal motoneurons5. This has been used to develop motoneuron isolation techniques to purify the cells from the vast majority of surrounding cells6. Isolating motoneurons with the help of specific antibodies (panning) against the extracellular domains of p75NTR has turned out to be an expensive method as the amount of antibody used for a single experiment is high due to the size of the plate used for panning. A much more economical alternative is the use of lectin. Lectin has been shown to specifically bind to p75NTR as well7. The following method describes an alternative technique using wheat germ agglutinin for a preplating procedure instead of the p75NTR antibody. The lectin is an extremely inexpensive alternative to the p75NTR antibody and the purification grades using

  20. Fishing for lectins from diverse sequence libraries by yeast surface display - an exploratory study.

    PubMed

    Ryckaert, Stefan; Callewaert, Nico; Jacobs, Pieter P; Dewaele, Sylviane; Dewerte, Isabelle; Contreras, Roland

    2008-02-01

    The establishment of a robust technology platform for the expression cloning of carbohydrate-binding proteins remains a key challenge in glycomics. Here we explore the utility of using yeast surface display (YSD) technology in the interaction-based lectin cloning from complete cDNA libraries. This should pave the way for more detailed studies of protein-carbohydrate interactions. To evaluate the performance of this system, lectins representing three different subfamilies (galectins, siglecs, and C-type lectins) were successfully displayed on the surface of Saccharomyces cerevisiae and Pichia pastoris as a-agglutinin and/or alpha-agglutinin fusions. The predicted carbohydrate-binding activity could be detected for three out of five lectins tested (galectin-1, galectin-3, and siaoadhesin). For galectin-4 and E-selectin, no specific carbohydrate-binding activity could be detected. We also demonstrate that proteins with carbohydrate affinity can be specifically isolated from complex metazoan cDNA libraries through multiple rounds of FACS sorting, employing multivalent, fluorescent-labeled polyacrylamide-based glycoconjugates. PMID:18086821

  1. MGL Receptor and Immunity: When the Ligand Can Make the Difference

    PubMed Central

    Zizzari, Ilaria Grazia; Battisti, Federico; Rahimi, Hassan; Caponnetto, Salvatore; Pierelli, Luca; Nuti, Marianna; Rughetti, Aurelia

    2015-01-01

    C-type lectin receptors (CLRs) on antigen-presenting cells (APCs) facilitate uptake of carbohydrate antigens for antigen presentation, modulating the immune response in infection, homeostasis, autoimmunity, allergy, and cancer. In this review, we focus on the role of the macrophage galactose type C-type lectin (MGL) in the immune response against self-antigens, pathogens, and tumor associated antigens (TAA). MGL is a CLR exclusively expressed by dendritic cells (DCs) and activated macrophages (MØs), able to recognize terminal GalNAc residues, including the sialylated and nonsialylated Tn antigens. We discuss the effects on DC function induced throughout the engagement of MGL, highlighting the importance of the antigen structure in the modulation of immune response. Indeed modifying Tn-density, the length, and steric structure of the Tn-antigens can result in generating immunogens that can efficiently bind to MGL, strongly activate DCs, mimic the effects of a danger signal, and achieve an efficient presentation in HLA classes I and II compartments. PMID:26839900

  2. The complete inventory of receptors encoded by the rat natural killer cell gene complex

    PubMed Central

    Flornes, Line M.; Nylenna, Øyvind; Saether, Per C.; Daws, Michael R.; Dissen, Erik

    2010-01-01

    The natural killer cell gene complex (NKC) encodes receptors belonging to the C-type lectin superfamily expressed primarily by NK cells and other leukocytes. In the rat, the chromosomal region that starts with the Nkrp1a locus and ends with the Ly49i8 locus is predicted to contain 67 group V C-type lectin superfamily genes, making it one of the largest congregation of paralogous genes in vertebrates. Based on physical proximity and phylogenetic relationships between these genes, the rat NKC can be divided into four major parts. We have previously reported the cDNA cloning of the majority of the genes belonging to the centromeric Nkrp1/Clr cluster and the two telomeric groups, the Klre1–Klri2 and the Ly49 clusters. Here, we close the gap between the Nkrp1/Clr and the Klre1–Klri2 clusters by presenting the cDNA cloning and transcription patterns of eight genes spanning from Cd69 to Dectin1, including the novel Clec2m gene. The definition, organization, and evolution of the rat NKC are discussed. Electronic supplementary material The online version of this article (doi:10.1007/s00251-010-0455-y) contains supplementary material, which is available to authorized users. PMID:20544345

  3. Specific interaction of human Tamm-Horsfall gylcoprotein with leucoagglutinin, a lectin from Phaseolus vulgaris (red kidney bean).

    PubMed Central

    Serafini-Cessi, F; Franceschi, C; Sperti, S

    1979-01-01

    Human Tamm-Horsfall glycoprotein inhibits lymphocyte transformation induced by leucoagglutinin and haemagglutinin from Phaseolus vulgaris (red kidney bean). The glycoprotein interacts with the two lectins, giving insoluble precipitates. The interaction with leucoagglutinin is highly specific, and the shape of the precipitin curve is that of an antigen-antibody reaction; precipitation is specifically inhibited by N-acetyl-D-galactosamine. Results are discussed, and it is suggested that inhibition of lymphocyte transformation is due to competition between human Tamm-Horsfall glycoprotein and carbohydrate receptors on lymphocytes for the two lectins. The interaction between human Tamm-Horsfall glycoprotein and Phaseolus vulgaris lectins has been used to develop a one-step procedure for the separation of the two lectins by affinity chromatography on (human Tamm-Horsfall-glycoprotein)-Sepharose. Images Fig. 1. Fig. 5. PMID:118744

  4. Cellular carbohydrate components in human, rabbit and rat lacrimal gland. Studies using fluorescein and peroxidase labelled lectins.

    PubMed

    Ahmed, A; Grierson, I

    1989-01-01

    Orbital lacrimal glands from adult male and female rabbits, rats and humans were examined for the presence of intracellular receptors of four lectins: concanavalin-A agglutinin, lutus tetragonolobus agglutinin, ricinus comunis-60 agglutinin and wheat-germ agglutinin using fluorescein-conjugated lectin and peroxidase labelling methods for fluorescence and electron microscopy, respectively. Lectins were used as specific probes to detect carbohydrate moiety of the lacrimal gland. The pattern of labelling with the lectins suggests that N-acetyl-glucosamine, N-acetyl-D-galactosamine, D-galactose, D-mannose, sialic acid and L-fucose are contained in the lacrimal gland of the three species. The significance of these findings is discussed. PMID:2920911

  5. Lectin binding studies on a glycopolymer brush flow-through biosensor by localized surface plasmon resonance.

    PubMed

    Rosencrantz, Ruben R; Nguyen, Vu Hoa; Park, Hyunji; Schulte, Christine; Böker, Alexander; Schnakenberg, Uwe; Elling, Lothar

    2016-08-01

    A localized surface plasmon resonance biosensor in a flow-through configuration was applied for investigating kinetics of lectin binding to surface-grafted glycopolymer brushes. Polycarbonate filter membranes with pore sizes of 400 nm were coated with a 114-nm thick gold layer and used as substrate for surface-initiated atom-transfer radical polymerization of a glycomonomer. These grafted from glycopolymer brushes were further modified with two subsequent enzymatic reactions on the surface to yield an immobilized trisaccharide presenting brush. Specific binding of lectins including Clostridium difficile toxin A receptor domain to the glycopolymer brush surface could be investigated in a microfluidic setup with flow-through of the analytes and transmission surface plasmon resonance spectroscopy. Graphical abstract Glycopolymer brushes serve as high affinity ligands for lectin and toxin interactions in a sensitive, disposable flow-through LSPR biosensor. PMID:27277814

  6. Identification of natural killer cell receptor genes in the genome of the marsupial Tasmanian devil (Sarcophilus harrisii).

    PubMed

    van der Kraan, Lauren E; Wong, Emily S W; Lo, Nathan; Ujvari, Beata; Belov, Katherine

    2013-01-01

    Within the mammalian immune system, natural killer (NK) cells contribute to the first line of defence against infectious agents and tumours. Their activity is regulated, in part, by cell surface NK cell receptors. NK receptors can be divided into two unrelated, but functionally analogous superfamilies based on the structure of their extracellular ligand-binding domains. Receptors belonging to the C-type lectin superfamily are predominantly encoded in the natural killer complex (NKC), while receptors belonging to the immunoglobulin superfamily are predominantly encoded in the leukocyte receptor complex (LRC). Natural killer cell receptors are emerging as a rapidly evolving gene family which can display significant intra- and interspecific variation. To date, most studies have focused on eutherian mammals, with significantly less known about the evolution of these receptors in marsupials. Here, we describe the identification of 43 immunoglobulin domain-containing LRC genes in the genome of the Tasmanian devil (Sarcophilus harrisii), the largest remaining marsupial carnivore and only the second marsupial species to be studied. We also identify orthologs of NKC genes KLRK1, CD69, CLEC4E, CLEC1B, CLEC1A and an ortholog of an opossum NKC receptor. Characterisation of these regions in a second, distantly related marsupial provides new insights into the dynamic evolutionary histories of these receptors in mammals. Understanding the functional role of these genes is also important for the development of therapeutic agents against Devil Facial Tumour Disease, a contagious cancer that threatens the Tasmanian devil with extinction. PMID:23007952

  7. Lectins in Castor Bean Seedlings 1

    PubMed Central

    Harley, Suzanne M.; Beevers, Harry

    1986-01-01

    The amounts of the two lectins (ricin and Ricinus communis agglutinin) in tissues of castor bean seedlings were followed during germination and early growth. For measurement, lectins in extracts were separately eluted from Sepharose columns; an antibody to the agglutinin was also used to detect the lectins by immunodiffusion. The endosperm of the dry seed contains 3.5 mg total lectin (5.6% of the total seed protein), which declines by 50% by day 4 and more rapidly thereafter as the tissue is completely consumed. The cotyledons of the dry seed also contain lectins but the amounts are less than 1% of those in the endosperm, and, as in the endosperm, they are constituents of the albumin fraction of the isolated protein bodies. No lectins were detected in the green cotyledons of 10-day seedlings that had been exposed to light from day 5. The embryonic axes of 2-day seedlings contained very small amounts of lectins but they were not detectable in the aerial parts of seedlings grown for 3 weeks or in cells from endosperm grown in tissue culture. The ability of proteinases and glycosidases (isolated from endosperm of 4-day seedlings) to hydrolyze the lectins was examined. No hydrolysis of the two lectins was observed, but the subunits, separated by reduction with 2-mercaptoethanol, were hydrolyzed slowly by a proteinase and some release of mannose was observed in the presence of the glycosidases. Ricin was converted to its subunits by cysteine and an enzyme in an endosperm extract accelerated chain separation by glutathione. Images Fig. 3 PMID:16664561

  8. [Antagonistic effect of gingerols against TNF-α release, ROS overproduction and RIP3 expression increase induced by lectin from Pinellia ternata].

    PubMed

    Yu, Hong-li; Mao, Shan-hu; Zhao, Teng-fei; Wu, Hao; Pan, Yao-zong; Shu, Chen-yan

    2015-09-01

    To explore the antagonistic effect of gingerols against the inflammation induced by lectin from Pinellia ternata. In this study, ELISA method was used to determine the effect of different extracts from gingerols on the release of inflammatory factor TNF-α from macrophages induced by lectin from P. ternata. The fluorescence probe was used to determine the effect of gingerols on the changes in ROS of macrophages induced by lectin from P. ternata. The western-blot method was applied to study the effect of gingerols on the increase in expression of cell receptor interacting protein RIP3 in macrophages induced by lectin from P. ternata. The scanning electron microscope (SEM) was used to study the effect of gingerols on morphological changes in macrophages induced by lectin from P. ternata. According to the results, gingerols can significantly inhibit the release of inflammatory factor from macrophages induced by lectin from P. ternata, ROS overproduction and increase in RIP3 expression. SEM results showed that gingerols can inhibit the cytomorphosis and necrocytosis induced by lectin from P. ternata. Fresh ginger's detoxication may be related to gingerols' effects in inhibiing release of inflammatory factor, ROS overproduction and increase in RIP3 expression caused by macrophages induced by lectin from P. ternata, which are mainly inflammatory development. PMID:26983212

  9. PURIFICATION, CHARACTERIZATION AND CLONING OF A RICIN B-LIKE LECTIN FROM MUSHROOM Clitocybe nebularis WITH ANTIPROLIFERATIVE ACTIVITY AGAINST HUMAN LEUKEMIC T CELLS

    PubMed Central

    Pohleven, Jure; Obermajer, Nataša; Sabotič, Jerica; Anžlovar, Sabina; Sepčić, Kristina; Kos, Janko; Kralj, Bogdan; Štrukelj, Borut; Brzin, Jože

    2009-01-01

    Background Lectins are a diverse group of carbohydrate-binding proteins exhibiting numerous biological activities and functions. Methods Two-step serial carbohydrate affinity chromatography was used to isolate a lectin from the edible mushroom clouded agaric (Clitocybe nebularis). It was characterized biochemically, its gene and cDNA cloned and the deduced amino acid sequence analyzed. Its activity was tested by hemagglutination assay and carbohydrate-binding specificity determined by glycan microarray analysis. Its effect on proliferation of several human cell lines was determined by MTS assay. Results A homodimeric lectin with 15.9-kDa subunits agglutinates human group A, followed by B, O, and bovine erythrocytes. Hemagglutination was inhibited by glycoprotein asialofetuin and lactose. Glycan microarray analysis revealed that the lectin recognizes human blood group A determinant GalNAcα1–3(Fucα1–2)Galβ-containing carbohydrates, and GalNAcβ1–4GlcNAc (N,N’-diacetyllactosediamine). The lectin exerts antiproliferative activity specific to human leukemic T cells. Conclusions The protein belongs to the ricin B-like lectin superfamily, and has been designated as Clitocybe nebularis lectin (CNL). Its antiproliferative effect appears to be elicited by binding to carbohydrate receptors on human leukemic T cells. General Significance CNL is one of the few mushroom ricin B-like lectins that have been identified and the only one so far shown to possess immunomodulatory properties. PMID:19100814

  10. An Overview of Pathogen Recognition Receptors for Innate Immunity in Dental Pulp

    PubMed Central

    Jang, Ji-Hyun; Shin, Hee Woong; Lee, Jung Min; Lee, Hyeon-Woo; Kim, Eun-Cheol; Park, Sang Hyuk

    2015-01-01

    Pathogen recognition receptors (PRRs) are a class of germ line-encoded receptors that recognize pathogen-associated molecular patterns (PAMPs). The activation of PRRs is crucial for the initiation of innate immunity, which plays a key role in first-line defense until more specific adaptive immunity is developed. PRRs differ in the signaling cascades and host responses activated by their engagement and in their tissue distribution. Currently identified PRR families are the Toll-like receptors (TLRs), the C-type lectin receptors (CLRs), the nucleotide-binding oligomerization domain-like receptors (NLRs), the retinoic acid-inducible gene-I-like receptors (RLRs), and the AIM2-like receptor (ALR). The environment of the dental pulp is substantially different from that of other tissues of the body. Dental pulp resides in a low compliance root canal system that limits the expansion of pulpal tissues during inflammatory processes. An understanding of the PRRs in dental pulp is important for immunomodulation and hence for developing therapeutic targets in the field of endodontics. Here we comprehensively review recent finding on the PRRs and the mechanisms by which innate immunity is activated. We focus on the PRRs expressed on dental pulp and periapical tissues and their role in dental pulp inflammation. PMID:26576076

  11. Characterization of a Lectin from Lactarius deterrimus (Research on the Possible Involvement of the Fungal Lectin in Recognition between Mushroom and Spruce during the Early Stages of Mycorrhizae Formation).

    PubMed Central

    Giollant, M.; Guillot, J.; Damez, M.; Dusser, M.; Didier, P.; Didier, E.

    1993-01-01

    A lectin (LDetL) was isolated from carpophores of the mushroom Lactarius deterrimus, a specific symbiont of the spruce, by a combination of affinity, hydroxylapatite, and gel-filtration chromatography. Its molecular mass, as determined by gel filtration, is about 37,000 D, and its structure is dimeric, with two identical subunits assembled by noncovalent bonds. It appeared homogeneous on high-performance liquid chromatography gel filtration, but isoelectric focusing revealed microheterogeneity, with a main band in the pH zone near 6.5. Amino acid analysis showed that LDetL contains a large proportion of glycine and especially methionine. Hapten inhibition assay indicated that LDetL is most specific for [beta]-D-galactosyl(1->3)-D-N-acetyl galactosamine residues. The lectin was formed in the in vitro-cultivated mycelium, and anti-lectin antibodies revealed by indirect immunofluorescence the presence of lectin in the cell wall. Receptor sites for LDetL were found on the roots, especially on the root hairs, of axenically grown spruce seedlings. The lectin LDL previously isolated by us from the taxonomically related mushroom Lactarius deliciosus, a symbiont of the pine, does not bind to the spruce radicle. This suggests a role of the fungal lectin in recognition and specificity during the early stages of mycorrhizae formation. PMID:12231706

  12. Mincle, an Innate Immune Receptor, Is Expressed in Urothelial Cancer Cells of Papillomavirus-Associated Urothelial Tumors of Cattle

    PubMed Central

    Roperto, Sante; Russo, Valeria; Esposito, Iolanda; Ceccarelli, Dora Maria; Paciello, Orlando; Avallone, Luigi; Capparelli, Rosanna; Roperto, Franco

    2015-01-01

    Background Mincle, macrophage-inducible C-type lectin, is a member of C-type lectin receptors. It plays an important role in anti-mycobacterial and anti-fungal immunity. Furthermore it senses dead cells through its primary ligand SAP130. Materials and Findings We examined ten urothelial tumors of the urinary bladder of cattle. Eight of them expressed E5 cDNA of bovine papillomaviruses type 2 (BPV-2) and type 13 (BPV-13) that belong to Deltapapillomavirus genus. Two of them were not examined for detection of E5 cDNA. Mincle expression appeared to occur in urothelial neoplastic cells only. No mincle expression was detected in urothelial cells from healthy cattle. Mincle expression was characterized by a membranous pattern in papillary urothelial cancers; isolated and/or clustered urothelial cells showing a strong cytoplasmic immunoreactivity were primarily seen in invasive urothelial cancers. Conclusion This is the first study about the expression of mincle in veterinary oncology and the first report which describes the expression of functional mincle receptor in neoplastic cells in medical literature. As it has been shown that urothelial cancer cells have the ability to function as antigen-presenting cells (APCs), it is conceivable that mincle expression is involved in the presentation of cancer cell antigens to cells of the immune system. Furthermore, since expression of mincle contributes to the control of Mycobacterium bovis BCG infection, this study has exciting clinical implications in comparative medicine keeping in mind that Bacillus Calmette-Guérin (BCG) immunotherapy is currently the most effective treatment of non-muscle invasive bladder cancer in man. Mincle expression in urothelial tumor cells warrants further study to better understand the role, if any, of this receptor in bladder cancer. Future studies will provide insights in the role of mincle receptor of urothelial cancer cells in antitumor immunotherapy. PMID:26513724

  13. Epidemiological characterization of Neisseria gonorrhoeae by lectins.

    PubMed Central

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

    1985-01-01

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

  14. Lectin affinity chromatography of glycolipids

    SciTech Connect

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

    1987-05-01

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

  15. Structural and functional properties of C-type starches.

    PubMed

    Cai, Jinwen; Cai, Canhui; Man, Jianmin; Zhou, Weidong; Wei, Cunxu

    2014-01-30

    This study investigated the structural and functional properties of C-type starches from pea seeds, faba bean seeds, yam rhizomes and water chestnut corms. These starches were mostly oval in shape with significantly different sizes and contents of amylose, damaged starch and phosphorus. Pea, faba bean and water chestnut starches had central hila, and yam starch had eccentric hilum. Water chestnut and yam starches had higher amylopectin short and long chain, respectively. Water chestnut and faba bean starches showed CA-type crystallinities, and pea and yam starches had C-type crystallinities. Water chestnut starch had the highest swelling power, granule swelling and pasting viscosity, lowest gelatinization temperatures and enthalpy. Faba bean starch had the lowest pasting viscosity, whereas yam starch had the highest gelatinization temperatures. Water chestnut and yam starches possessed significantly higher and lower susceptibility to acid and enzyme hydrolysis, the highest and lowest RDS contents, and the lowest and highest RS contents, respectively. PMID:24299776

  16. 21 CFR 864.9550 - Lectins and protectins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Lectins and protectins. 864.9550 Section 864.9550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... and Blood Products § 864.9550 Lectins and protectins. (a) Identification. Lectins and protectins...

  17. 21 CFR 864.9550 - Lectins and protectins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Lectins and protectins. 864.9550 Section 864.9550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... and Blood Products § 864.9550 Lectins and protectins. (a) Identification. Lectins and protectins...

  18. 21 CFR 864.9550 - Lectins and protectins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Lectins and protectins. 864.9550 Section 864.9550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... and Blood Products § 864.9550 Lectins and protectins. (a) Identification. Lectins and protectins...

  19. 21 CFR 864.9550 - Lectins and protectins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Lectins and protectins. 864.9550 Section 864.9550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... and Blood Products § 864.9550 Lectins and protectins. (a) Identification. Lectins and protectins...

  20. Hayabusa2, C-type Asteroid Sample Return Mission

    NASA Astrophysics Data System (ADS)

    Takagi, Y.; Yoshikawa, M.; Abe, M.; Tachibana, S.; Okada, T.; Kitazato, K.; Nakamura, R.; Hirata, N.; Yano, H.; Demura, H.; Nakazawa, S.; Iijima, Y.; Shirai, K.; Hayakawa, M.; Hayabusa 2 Project Team

    2011-12-01

    Asteroid Explorer "Hayabusa2" is a successor of "Hayabusa" (MUSES-C), which revealed several new technologies and returned to Earth in June 2010. While establishing a new navigation method using ion engines, Hayabusa brought back samples from the asteroid "Itokawa" to help elucidate the origin of the solar system. Hayabusa2 will target a C-type asteroid "1999 JU3" to study the origin and evolution of the solar system as well as materials for life by leveraging the experience acquired from the Hayabusa mission. To learn more about the origin and evolution of the solar system, it is important to investigate typical types of asteroids, namely S-, C-, and D-type asteroids. A C-type asteroid, which is a target of Hayabusa2, is a more primordial body than Itokawa, which is an S-type asteroid, and is considered to contain more organic or hydrated minerals -- although both S- and C- types have lithologic characteristics. Minerals and seawater which form the Earth as well as materials for life are believed to be strongly connected in the primitive solar nebula in the early solar system, thus we expect to clarify the origin of life by analyzing samples acquired from a primordial celestial body such as a C-type asteroid to study organic matter and water in the solar system and how they coexist while affecting each other. Hayabusa2 will utilize new technology while further confirming the deep space round-trip exploration technology by inheriting and improving the already verified knowhow established by Hayabusa to construct the basis for future deep-space exploration. The configuration of Hayabusa2 is basically the same as that of Hayabusa, but we will modify some parts by introducing novel technologies that evolved after the Hayabusa era. For example, the antenna for Hayabusa was in a parabolic shape, but the one for Hayabusa2 will be flattened. Also, a new function, "collision device", is considered to be onboard to create a crater artificially. An artificial crater that can

  1. Carbohydrate-lectin interactions assayed by SPR.

    PubMed

    Duverger, Eric; Lamerant-Fayel, Nathalie; Frison, Natacha; Monsigny, Michel

    2010-01-01

    Surface plasmon resonance is a valuable tool to determine the affinity between glycoconjugates and sugar-binding proteins such as plant and animal lectins. The main interest of using such an approach is that neither the lectins - which are proteins - nor their ligands - natural compounds such as glycoproteins, oligosaccharides, polysaccharides, or synthetic glycoconjugates such as glycoclusters or neoglycoproteins - require any tag. Because lectins bear several binding sites, they behave like immunoglobulin eliciting avidity phenomena. This peculiarity may lead to erroneous results if special conditions are not applied. We obtained best and reproducible results when the lectin was immobilized and its ligands were used as soluble analytes. With heterogeneous glycoconjugates such as neoglycoproteins (which are heterogeneous in terms of nature, number, and position of sugar residues) or a mixture of oligosaccharides, the data may be more accurately gathered by using the Sips approach, which has been used to determine mean binding constants of polyclonal antibodies. With small analytes such as oligosaccharides, we found it convenient to determine binding constants by using an inhibitory approach: a neoglycoprotein (M (r) = approximately 80,000) was allowed to bind to the immobilized lectin and small oligosaccharides were used as inhibitors. With larger glycoconjugates such as peptides substituted with glycoclusters, direct binding measurements gave accurate results. Because of the availability of low-cost simple sugars (mono- or disaccharides) it is very convenient to use large concentrations of such carbohydrates to clean the sensor chips instead of more drastic cleaning solutions such as acids or alkali, in such a way that the immobilized lectin is stable for many experiments. PMID:20217620

  2. Lectin glycoprofiling of recombinant therapeutic interleukin-7.

    PubMed

    Landemarre, Ludovic; Duverger, Eric

    2013-01-01

    Lectins array is a powerfull and complementary method of glycans analysis allowing fast identification of specific motifs on molecules or cells. This technology is of increased interest for the development of therapeutic recombinant glycoproteins and particularly relevant for a first study of lot-to-lot comparison, or detection of unwanted glycans. In this chapter, we describe a lectin array-type method specifically designed for the study of recombinant therapeutic interleukin-7 (rhIL-7). This specific method allows the analysis of the glycans motifs, the distribution of the glycoforms population, and the detection of potential immunogen glycans in rhIL-7 purified CHO-produced batches. PMID:23475723

  3. Effect of lectins on mouse peritoneal macrophage phagocytic activity.

    PubMed

    Maldonado, G; Porras, F; Fernández, L; Vázquez, L; Zenteno, E

    1994-11-01

    We studied the in vitro ability of lectin-treated murine peritoneal macrophages to attach and phagocytize particulate antigens. Glucose and mannose specific lectins such as Con-A and lentil lectin, as well as complex lactosamine residues specific lectins, such as Phaseolus vulgaris var. cacahuate and Phaseolus coccineus var. alubia, increased the macrophage phagocytic activity towards heterologous erythrocytes, whereas peanut agglutinin, a galactose-specific lectin, diminished the macrophage phagocytic activity. These results suggest that a galactose-N-acetyl-D galactosamine-containing structure could participate as negative modulator of the phagocytic activity. PMID:7851961

  4. Toll-like receptors: the swiss army knife of immunity and vaccine development

    PubMed Central

    Dowling, Jennifer K; Mansell, Ashley

    2016-01-01

    Innate immune cells have a critical role in defense against infection and disease. Central to this is the broad specificity with which they can detect pathogen-associated patterns and danger-associated patterns via the pattern recognition receptors (PRRs) they express. Several families of PRRs have been identified including: Toll-like receptors (TLRs), C-type lectin-like receptors, retinoic acid-inducible gene-like receptors and nucleotide-binding oligomerization domain–like receptors. TLRs are one of the most largely studied families of PRRs. The binding of ligands to TLRs on antigen presenting cells (APCs), mainly dendritic cells, leads to APC maturation, induction of inflammatory cytokines and the priming of naive T cells to drive acquired immunity. Therefore, activation of TLRs promotes both innate inflammatory responses and the induction of adaptive immunity. Consequently, in the last two decades mounting evidence has inextricably linked TLR activation with the pathogenesis of immune diseases and cancer. It has become advantageous to harness these aspects of TLR signaling therapeutically to accelerate and enhance the induction of vaccine-specific responses and also target TLRs with the use of biologics and small molecule inhibitors for the treatment of disease. In these respects, TLRs may be considered a ‘Swiss Army' knife of the immune system, ready to respond in a multitude of infectious and disease states. Here we describe the latest advances in TLR-targeted therapeutics and the use of TLR ligands as vaccine adjuvants. PMID:27350884

  5. Combined Bacteria Microarray and Quartz Crystal Microbalance Approach for Exploring Glycosignatures of Nontypeable Haemophilus influenzae and Recognition by Host Lectins.

    PubMed

    Kalograiaki, Ioanna; Euba, Begoña; Proverbio, Davide; Campanero-Rhodes, María A; Aastrup, Teodor; Garmendia, Junkal; Solís, Dolores

    2016-06-01

    Recognition of bacterial surface epitopes by host receptors plays an important role in the infectious process and is intimately associated with bacterial virulence. Delineation of bacteria-host interactions commonly relies on the detection of binding events between purified bacteria- and host-target molecules. In this work, we describe a combined microarray and quartz crystal microbalance (QCM) approach for the analysis of carbohydrate-mediated interactions directly on the bacterial surface, thus preserving the native environment of the bacterial targets. Nontypeable Haemophilus influenzae (NTHi) was selected as a model pathogenic species not displaying a polysaccharide capsule or O-antigen-containing lipopolysaccharide, a trait commonly found in several important respiratory pathogens. Here, we demonstrate the usefulness of NTHi microarrays for exploring the presence of carbohydrate structures on the bacterial surface. Furthermore, the microarray approach is shown to be efficient for detecting strain-selective binding of three innate immune lectins, namely, surfactant protein D, human galectin-8, and Siglec-14, to different NTHi clinical isolates. In parallel, QCM bacteria-chips were developed for the analysis of lectin-binding kinetics and affinity. This novel QCM approach involves capture of NTHi on lectin-derivatized chips followed by formaldehyde fixation, rendering the bacteria an integrated part of the sensor chip, and subsequent binding assays with label-free lectins. The binding parameters obtained for selected NTHi-lectin pairs provide further insights into the interactions occurring at the bacterial surface. PMID:27176788

  6. 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

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

    PubMed

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

    2015-01-01

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

  8. Lectins from tropical sponges. Purification and characterization of lectins from genus Aplysina.

    PubMed

    Miarons, P B; Fresno, M

    2000-09-22

    Only a few animal phyla have been screened for the presence and distribution of lectins. Probably the most intensively studied group is the mollusk. In this investigation, 22 species from 12 families of tropical sponges collected in Los Roques National Park (Venezuela) were screened for the presence of lectins. Nine saline extracts exhibited strong hemagglutinating activity against pronase-treated hamster red blood cells; five of these reacted against rabbit red blood cells, four with trypsin-treated bovine red blood cells, and five with human red blood cells regardless of the blood group type. Extracts from the three species studied from genus Aplysina (archeri, lawnosa, and cauliformis) were highly reactive and panagglutinating against the panel of red blood cells tested. The lectins from A. archeri and A. lawnosa were purified to homogeneity by ammonium sulfate fractionation, affinity chromatography on p-aminobenzyl-beta-1-thiogalactopyranoside-agarose, and gel filtration chromatography. Both lectins exhibited a native molecular mass of 63 kDa and by SDS-polyacrylamide gel electrophoresis under reducing conditions have an apparent molecular mass of 16 kDa, thus suggesting they occur as homotetramers. The purified lectins contain 3-4 mol of divalent cation per molecule, which are essential for their biological activity. Hapten inhibition of hemagglutination was carried out to define the sugar binding specificity of the purified A. archeri lectin. The results indicate a preference of the lectin for nonreducing beta-linked d-Gal residues being the best inhibitors of red blood cells binding methyl-beta-d-Gal and thiodigalactoside (Gal beta 1-4-thiogalactopyranoside). The behavior of several glycans on immobilized lectin affinity chromatography confirmed and extended the specificity data obtained by hapten inhibition. PMID:10852905

  9. Collaborative action of Toll-like and NOD-like receptors as modulators of the inflammatory response to pathogenic bacteria.

    PubMed

    Oviedo-Boyso, Javier; Bravo-Patiño, Alejandro; Baizabal-Aguirre, Víctor M

    2014-01-01

    Early sensing of pathogenic bacteria by the host immune system is important to develop effective mechanisms to kill the invader. Microbial recognition, activation of signaling pathways, and effector mechanisms are sequential events that must be highly controlled to successfully eliminate the pathogen. Host recognizes pathogens through pattern-recognition receptors (PRRs) that sense pathogen-associated molecular patterns (PAMPs). Some of these PRRs include Toll-like receptors (TLRs), nucleotide-binding oligomerization domain-like receptors (NLRs), retinoic acid-inducible gene-I- (RIG-I-) like receptors (RLRs), and C-type lectin receptors (CLRs). TLRs and NLRs are PRRs that play a key role in recognition of extracellular and intracellular bacteria and control the inflammatory response. The activation of TLRs and NLRs by their respective ligands activates downstream signaling pathways that converge on activation of transcription factors, such as nuclear factor-kappaB (NF-κB), activator protein-1 (AP-1) or interferon regulatory factors (IRFs), leading to expression of inflammatory cytokines and antimicrobial molecules. The goal of this review is to discuss how the TLRs and NRLs signaling pathways collaborate in a cooperative or synergistic manner to counteract the infectious agents. A deep knowledge of the biochemical events initiated by each of these receptors will undoubtedly have a high impact in the design of more effective strategies to control inflammation. PMID:25525300

  10. Collaborative Action of Toll-Like and Nod-Like Receptors as Modulators of the Inflammatory Response to Pathogenic Bacteria

    PubMed Central

    Bravo-Patiño, Alejandro; Baizabal-Aguirre, Víctor M.

    2014-01-01

    Early sensing of pathogenic bacteria by the host immune system is important to develop effective mechanisms to kill the invader. Microbial recognition, activation of signaling pathways, and effector mechanisms are sequential events that must be highly controlled to successfully eliminate the pathogen. Host recognizes pathogens through pattern-recognition receptors (PRRs) that sense pathogen-associated molecular patterns (PAMPs). Some of these PRRs include Toll-like receptors (TLRs), nucleotide-binding oligomerization domain-like receptors (NLRs), retinoic acid-inducible gene-I- (RIG-I-) like receptors (RLRs), and C-type lectin receptors (CLRs). TLRs and NLRs are PRRs that play a key role in recognition of extracellular and intracellular bacteria and control the inflammatory response. The activation of TLRs and NLRs by their respective ligands activates downstream signaling pathways that converge on activation of transcription factors, such as nuclear factor-kappaB (NF-κB), activator protein-1 (AP-1) or interferon regulatory factors (IRFs), leading to expression of inflammatory cytokines and antimicrobial molecules. The goal of this review is to discuss how the TLRs and NRLs signaling pathways collaborate in a cooperative or synergistic manner to counteract the infectious agents. A deep knowledge of the biochemical events initiated by each of these receptors will undoubtedly have a high impact in the design of more effective strategies to control inflammation. PMID:25525300

  11. γ-Tilmanocept, a New Radiopharmaceutical Tracer for Cancer Sentinel Lymph Nodes, Binds to the Mannose Receptor (CD206)

    PubMed Central

    Azad, Abul K.; Rajaram, Murugesan V. S.; Metz, Wendy L.; Cope, Frederick O.; Blue, Michael S.; Vera, David R.

    2015-01-01

    γ-Tilmanocept (99mTc-labeled-tilmanocept or [99mTc]-tilmanocept) is the first mannose-containing, receptor-directed, radiolabeled tracer for the highly sensitive imaging of sentinel lymph nodes in solid tumor staging. To elucidate the mannose-binding receptor that retains tilmanocept in this microenvironment, human macrophages were used that have high expression of the C-type lectin mannose receptor (MR; CD206). Cy3-labeled tilmanocept exhibited high specificity binding to macrophages that was nearly abolished in competitive inhibition experiments. Furthermore, Cy3-tilmanocept binding was markedly reduced on macrophages deficient in the MR by small interfering RNA treatment and was increased on MR-transfected HEK 293 cells. Finally, confocal microscopy revealed colocalization of Cy3-tilmanocept with the macrophage membrane MR and binding of labeled tilmanocept to MR+ cells (macrophages and/or dendritic cells) in human sentinel lymph node tissues. Together these data provide strong evidence that CD206 is a major binding receptor for γ-tilmanocept. Identification of CD206 as the γ-tilmanocept–binding receptor enables opportunities for designing receptor-targeted advanced imaging agents and therapeutics for cancer and other diseases. PMID:26202986

  12. Characterization of a lectin from the craysfish Cherax quadricarinatus hemolymph and its effect on hemocytes.

    PubMed

    Sánchez-Salgado, J L; Pereyra, M A; Vivanco-Rojas, O; Sierra-Castillo, C; Alpuche-Osorno, J J; Zenteno, E; Agundis, C

    2014-08-01

    Lectins participate in the immune mechanisms of crustaceans. They have been considered as humoral receptors for pathogen-associated molecular patterns; however, some reports suggest that lectins could regulate crustacean cellular functions. In the present study, we purified and characterized a serum lectin (CqL) from the hemolymph of Cherax quadricarinatus by affinity chromatography and determined its participation in the regulation of hemocytes' oxidative burst. CqL is a 290-kDa lectin in native form, constituted by 108, 80, and 29-kDa subunits. It is mainly composed of glycine, alanine, and a minor proportion of methionine and histidine. It showed no carbohydrates in its structure. CqL is composed of several isoforms, as determined by 2D-electrophoresis, and shows no homology with any crustacean protein as determined by Lc/Ms mass spectrometry. CqL agglutinated mainly rat and rabbit erythrocytes and showed a broad specificity for monosaccharides such as galactose, glucose, and sialic acid, as well as for glycoproteins, such as porcine stomach and bovine submaxillary mucin and fetuin. It is a Mn(2+)-dependent lectin. CqL recognized 8% of crayfish granular hemocytes and increased 4.2-fold the production of hemocytes' superoxide anion in vitro assays when compared with non-treated hemocytes. This effect showed the same specificity for carbohydrates as hemagglutination; moreover, superoxide dismutase and diphenyleneiodonium chloride were effective inhibitors of CqL oxidative-activation. The CqL homoreceptor is a 120-kDa glycoprotein identified in the hemocytes lysate. Our results suggest that CqL participates actively in the regulation of the generation of superoxide anions in hemocytes using NADPH-dependent mechanisms. PMID:24929243

  13. Identification of glycoprotein receptors within the human salivary proteome for the lectin-like BabA and SabA adhesins of Helicobacter pylori by fluorescence-based 2-D bacterial overlay.

    PubMed

    Walz, Anke; Odenbreit, Stefan; Stühler, Kai; Wattenberg, Andreas; Meyer, Helmut E; Mahdavi, Jafar; Borén, Thomas; Ruhl, Stefan

    2009-03-01

    Because gastric infection by Helicobacter pylori takes place via the oral route, possible interactions of this bacterium with human salivary proteins could occur. By using modified 1- and 2-D bacterial overlay, binding of H. pylori adhesins BabA and SabA to the whole range of salivary proteins was explored. Bound salivary receptor molecules were identified by MALDI-MS and by comparison to previously established proteome maps of whole and glandular salivas. By use of adhesin-deficient mutants, binding of H. pylori to MUC7 and gp-340 could be linked to the SabA and BabA adhesins, respectively, whereas binding to MUC5B was associated with both adhesins. Binding of H. pylori to the proline-rich glycoprotein was newly detected and assigned to BabA adhesin whereas the SabA adhesin was found to mediate binding to newly detected receptor molecules, including carbonic anhydrase VI, secretory component, heavy chain of secretory IgA1, parotid secretory protein and zinc-alpha(2)-glycoprotein. Some of these salivary glycoproteins are known to act as scavenger molecules or are involved in innate immunity whereas others might come to modify the pathogenetic properties of this organism. In general, this 2-D bacterial overlay technique represents a useful supplement in adhesion studies of bacteria with complex protein mixtures. PMID:19253298

  14. Development and Applications of the Lectin Microarray.

    PubMed

    Hirabayashi, Jun; Kuno, Atsushi; Tateno, Hiroaki

    2015-01-01

    The lectin microarray is an emerging technology for glycomics. It has already found maximum use in diverse fields of glycobiology by providing simple procedures for differential glycan profiling in a rapid and high-throughput manner. Since its first appearance in the literature in 2005, many application methods have been developed essentially on the same platform, comprising a series of glycan-binding proteins immobilized on an appropriate substrate such as a glass slide. Because the lectin microarray strategy does not require prior liberation of glycans from the core protein in glycoprotein analysis, it should encourage researchers not familiar with glycotechnology to use glycan analysis in future work. This feasibility should provide a broader range of experimental scientists with good opportunities to investigate novel aspects of glycoscience. Applications of the technology include not only basic sciences but also the growing fields of bio-industry. This chapter describes first the essence of glycan profiling and the basic fabrication of the lectin microarray for this purpose. In the latter part the focus is on diverse applications to both structural and functional glycomics, with emphasis on the wide applicability now available with this new technology. Finally, the importance of developing advanced lectin engineering is discussed. PMID:25821171

  15. A mushroom lectin from ascomycete Cordyceps militaris.

    PubMed

    Jung, Eui Cha; Kim, Ki Don; Bae, Chan Hyung; Kim, Ju Cheol; Kim, Dae Kyong; Kim, Ha Hyung

    2007-05-01

    A mushroom lectin has been purified from ascomycete Cordyceps militaris, which is one of the most popular mushrooms in eastern Asia used as a nutraceutical and in traditional Chinese medicine. This lectin, designated CML, exhibited hemagglutination activity in mouse and rat erythrocytes, but not in human ABO erythrocytes. SDS-PAGE of CML revealed a single band with a molecular mass of 31.0 kDa under both nonreducing and reducing conditions that was stained by silver nitrate, and a 31.4 kDa peak in a Superdex-200 HR gel-filtration column. The hemagglutination activity was inhibited by sialoglycoproteins, but not in by mono- or disaccharides, asialoglycoproteins, or de-O-acetylated glycoprotein. The activity was maximal at pH 6.0-9.1 and at temperatures below 50 degrees C. Circular dichroism spectrum analysis revealed that CML comprises 27% alpha-helix, 12% beta-sheets, 29% beta-turns, and 32% random coils. Its binding specificity and secondary structure are similar to those of a fungal lectin from Arthrobotrys oligospora. However, the N-terminal amino acid sequence of CML differs greatly from those of other lectins. CML exhibits mitogenic activity against mouse splenocytes. PMID:17306462

  16. Lectin genes in the Frankia alni genome.

    PubMed

    Pujic, Petar; Fournier, Pascale; Alloisio, Nicole; Hay, Anne-Emmanuelle; Maréchal, Joelle; Anchisi, Stéphanie; Normand, Philippe

    2012-01-01

    Frankia alni strain ACN14a's genome was scanned for the presence of determinants involved in interactions with its host plant, Alnus spp. One such determinant type is lectin, proteins that bind specifically to sugar motifs. The genome of F. alni was found to contain 7 such lectin-coding genes, five of which were of the ricinB-type. The proteins coded by these genes contain either only the lectin domain, or also a heat shock protein or a serine-threonine kinase domain upstream. These lectins were found to have several homologs in Streptomyces spp., and a few in other bacterial genomes among which none in Frankia EAN1pec and CcI3 and two in strain EUN1f. One of these F. alni genes, FRAAL0616, was cloned in E. coli, fused with a reporter gene yielding a fusion protein that was found to bind to both root hairs and to bacterial hyphae. This protein was also found to modify the dynamics of nodule formation in A. glutinosa, resulting in a higher number of nodules per root. Its role could thus be to permit binding of microbial cells to root hairs and help symbiosis to occur under conditions of low Frankia cell counts such as in pioneer situations. PMID:22159868

  17. Non-labeled QCM Biosensor for Bacterial Detection using Carbohydrate and Lectin Recognitions

    PubMed Central

    Shen, Zhihong; Huang, Mingchuan; Xiao, Caide; Zhang, Yun; Zeng, Xiangqun; Wang, Peng G.

    2008-01-01

    also increases the binding of bacteria to their carbohydrate receptor through bacterial surface binding lectins that significantly enhanced specificity and sensitivity of QCM biosensors. Combining carbohydrate and lectin recognition events with an appropriate QCM transducer can yield sensor devices highly suitable for the fast, reversible and straightforward on-line screening and detection of bacteria in food, water, clinical and biodefense areas. PMID:17295446

  18. 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.

  19. Displacement phenomena in lectin affinity chromatography.

    PubMed

    Cho, Wonryeon

    2015-10-01

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

  20. Inhibition of phagocytic activity by the N-acetyl-D-galactosamine-specific lectin from Amaranthus leucocarpus.

    PubMed

    Maldonado, G; Gorocica, P; Agundis, C; Pérez, A; Molina, J; Zenteno, E

    1998-06-01

    Amaranthus leucocarpus lectin (ALL), specific for N-acetyl-D-galactosamine, induces inhibition of the erythrophagocytic activity of resident murine peritoneal macrophages and of the macrophage-like cell line J-774. This effect was observed only in macrophages that were Mac-2 (CD11c/CD18 or CR4) negative, indicating that macrophage activation induces important modification to the glycosylation (mainly O-glycosylation) of the membrane. Receptors for IgM and C3b remain unaltered after lectin treatment. Ultrastructural analysis revealed (a) that ALL induced the formation of pinocytic vacuoles, and (b) a regular distribution over the macrophage membrane as well as endosomal vesicles of the gold labeled ALL. Our results suggest that macrophage membrane glycoproteins with constitutive N-acetyl-D-galactosamine residues participate in the regulation of pinocytic-phagocytic vacuole formation. PMID:9881768

  1. Targeting Angiogenesis Using a C-Type Atrial Natriuretic Factor–Conjugated Nanoprobe and PET

    PubMed Central

    Liu, Yongjian; Pressly, Eric D.; Abendschein, Dana R.; Hawker, Craig J.; Woodard, Geoffrey E.; Woodard, Pamela K.; Welch, Michael J.

    2014-01-01

    Sensitive, specific, and noninvasive detection of angiogenesis would be helpful in discovering new strategies for the treatment of cardiovascular diseases. Recently, we reported the 64Cu-labeled C-type atrial natriuretic factor (CANF) fragment for detecting the upregulation of natriuretic peptide clearance receptor (NPR-C) with PET on atherosclerosis-like lesions in an animal model. However, it is unknown whether NPR-C is present and overexpressed during angiogenesis. The goal of this study was to develop a novel CANF-integrated nanoprobe to prove the presence of NPR-C and offer sensitive detection with PET during development of angiogenesis in mouse hind limb. Methods We prepared a multifunctional, core-shell nanoparticle consisting of DOTA chelators attached to a poly(methyl methacrylate) core and CANF-targeting moieties attached to poly(ethylene glycol) chain ends in the shell of the nanoparticle. Labeling of this nanoparticle with 64Cu yielded a high-specific-activity nanoprobe for PET imaging NPR-C receptor in a mouse model of hind limb ischemia–induced angiogenesis. Histology and immunohistochemistry were performed to assess angiogenesis development and NPR-C localization. Results 15O-H2O imaging showed blood flow restoration in the previously ischemic hind limb, consistent with the development of angiogenesis. The targeted DOTA-CANF-comb nanoprobe showed optimized pharmacokinetics and biodistribution. PET imaging demonstrated significantly higher tracer accumulation for the targeted DOTA-CANF-comb nanoprobe than for either the CANF peptide tracer or the nontargeted control nanoprobe (P < 0.05, both). Immunohistochemistry confirmed NPR-C upregulation in the angiogenic lesion with colocalization in both endothelial and smooth muscle cells. PET and immunohistochemistry competitive receptor blocking verified the specificity of the targeted nanoprobe to NPR-C receptor. Conclusion As evidence of its translational potential, this customized DOTA

  2. Sizes and Albedos of Young C-type Asteroids

    NASA Astrophysics Data System (ADS)

    Tamblyn, Peter; Chapman, Clark; Durda, Dan; Merline, William; Nesvorny, David

    2005-06-01

    We propose to measure the sizes and albedos of 8 very young C-type asteroids with IRAC 8um and near-simultaneous ground-based visible photometry. Asteroid families are created from major collisions between asteroids and are identified from clustering of orbital elements. Co-I Nesvorny has recently identified an exceptionally-young family (Veritas) and precisely-dated it at only 8.3+/-0.5 Myr (just 0.2% of the age of the solar system). We will compare our results for this family with those obtained by our similar Spitzer GO-1 program where we study an even younger S-type family, Karin. C-type asteroids are composed of primitive material (as opposed to the more processed silicate-rich S-types) and comprise the majority of asteorids in the Main Belt, yet their compositions and properties remain elusive. These recent breakup events provide unparalleled opportunities to study compositions, dynamics, and collisions of asteroids. They allow tests of the rates of physical processes that happen on time scales comparable with the family age. Space weathering, for example, appears to affect C- and S-type asteroids very differently. We will test directly whether the Veritas fragments have similar albedos; we will also test if their albedos differ from those of similar asteroids with much older surfaces by study of a second C-type family, Themis. We will compare our observations with those made of larger asteroids of both families, from a companion ground-based program. We will quantify any correlation of size with albedo, a dominant uncertainty in standard size estimates. The size distribution will be used to calibrate hydrocode models of asteroid collisions. To do this will require observations at the smallest practical sizes. In addition, the measured sizes will be immediately applicable to a novel measurement of the Yarkovsky Effect. We have already demonstrated in our GO-1 program that we can make similar Spitzer observations and provide the ground-based visible support.

  3. Effect of lectins on hepatic clearance and killing of Candida albicans by the isolated perfused mouse liver.

    PubMed Central

    Sawyer, R T; Garner, R E; Hudson, J A

    1992-01-01

    The isolated perfused mouse liver model was used to study the effects of various lectins on hepatic trapping and killing of Candida albicans. After mouse livers were washed with 20 to 30 ml of perfusion buffer, 10(6) C. albicans CFU were infused into the livers. At the time of recovery, 63% +/- 2% (mean +/- standard error of the mean) of the infused C. albicans CFU were recovered from the liver and 14% +/- 1% were recovered from the effluent for a total recovery of 77% +/- 2%. This indicated that 86% +/- 9% of the original inoculum was trapped by the liver and that 23% +/- 2% was killed within the liver. When included in both preperfusion and postperfusion buffers (0.2 mg of lectin per ml), Ulex europeaus lectin (binding specificity for fucose) decreased hepatic trapping of C. albicans by 37% and eluted trapped C. albicans from the liver only when included in postperfusion buffer. By comparison, treatment of C. albicans with U. europeaus lectin before infusion had no effect on the trapping or killing of yeast cells. When Lens culinaris lectin (binding specificity for mannose) was included in the perfusion buffers, hepatic killing of C. albicans increased by 16% with no significant effect on hepatic killing when yeast cells were treated with L. culinaris lectin before infusion. Forty to 55% of the infused C. albicans were killed when concanavalin A (binding specificities for mannose and glucose), Glycine max (binding specificity for N-acetylgalactosamine), or Arachis hypogea (binding specificity for galactose) lectin was included in the perfusion buffer or when yeast cells were treated with these lectins before their infusion. When C. albicans was treated with concanavalin A at a concentration of less than 0.02 mg/ml, hepatic killing of yeast cells was not significantly increased. The data suggest that a fucose-containing receptor on the surface of either sinusoidal endothelial cells or Kupffer cells is involved in the trapping of C. albicans by the perfused mouse

  4. Characterization of functional mannose receptor in a continuous hybridoma cell line

    PubMed Central

    2012-01-01

    Background The mannose receptor is the best described member of the type I transmembrane C-type lectins; however much remains unanswered about the biology of the receptor. One difficulty has been the inability to consistently express high levels of a functional full length mannose receptor cDNA in mammalian cells. Another difficulty has been the lack of a human macrophage cell line expressing a fully functional receptor. Commonly used human macrophage cell lines such as U937, THP-1, Mono-Mac and HL60 do not express the mannose receptor. We have developed a macrophage hybridoma cell line (43MR cells) created by fusion of U937 cells with primary human monocyte-derived macrophages, resulting in a non-adherent cell line expressing several properties of primary macrophages. The purpose of this study was to identify and select mannose receptor-expressing cells using fluorescence-activated cell sorting and to characterize the expression and function of the receptor. Results In the current study we show that the mannose receptor found on this novel cell has endocytic characteristics consistent with and similar to the mannose receptor found on the surface of monocyte-derived human macrophages and rat bone marrow-derived macrophages. In addition, we demonstrate that these cells engage and internalize pathogen particles such as S. aureus and C. albicans. We further establish the transfectability of these cells via the introduction of a plasmid expressing influenza A hemagglutinin. Conclusions The 43MR cell line represents the first naturally expressed MR-positive cell line derived from a human macrophage background. This cell line provides an important cell model for other researchers for the study of human MR biology and host-pathogen interactions. PMID:22967244

  5. Molecular evolution of shark C-type natriuretic peptides.

    PubMed

    Takano, M; Sasayama, Y; Takei, Y

    1994-06-01

    C-type natriuretic peptides (CNP) of varying length were isolated from the atrium or ventricle of a shark, Lamna ditropis and their amino acid sequences were determined. Although the sequence of Lamna CNP was highly homologous to those of other CNPs sequenced to date, the Lamna CNP-41, the longest CNP identified in this study, has one amino acid replacement from those of Triakis scyllia and Scyliorhinus canicula, and three amino acid replacements from that of Squalus acanthias. The degree of similarity of CNP molecules coincides well with their systematic positions in the cladogram of elasmobranchs; Lamna, Triakis and Scyliorhinus belong to the same order, but Lamna and Squalus belong to different orders. The facts that Lamna and Triakis are in different suborders but Triakis and Scyliorhinus are in the same suborder and have identical CNP-41, also support this evolutionary implication. PMID:7765421

  6. P2C-Type ATPases and Their Regulation.

    PubMed

    Retamales-Ortega, Rocío; Vio, Carlos P; Inestrosa, Nibaldo C

    2016-03-01

    P2C-type ATPases are a subfamily of P-type ATPases comprising Na(+)/K(+)-ATPase and H(+)/K(+)-ATPase. Na(+)/K(+)-ATPase is ubiquitously expressed and has been implicated in several neurological diseases, whereas H(+)/K(+)-ATPase is found principally in the colon, stomach, and kidney. Both ATPases have two subunits, α and β, but Na(+)/K(+)-ATPase also has a regulatory subunit called FXYD, which has an important role in cancer. The most important functions of these ATPases are homeostasis, potassium regulation, and maintaining a gradient in different cell types, like epithelial cells. Na(+)/K(+)-ATPase has become a center of attention ever since it was proposed that it might play a crucial role in neurological disorders such as bipolar disorder, mania, depression, familial hemiplegic migraine, rapid-onset dystonia parkinsonism, chronic stress, epileptogenesis, and Alzheimer's disease. On the other hand, it has been reported that lithium could have a neuroprotective effect against ouabain, which is the best known Na(+)/K(+)-ATPase inhibitor, but and high concentrations of lithium could affect negatively H(+)/K(+)-ATPase activity, that has a key role in regulating acidosis and potassium deficiencies. Finally, potassium homeostasis regulation is composed of two main mechanisms, extrarenal and renal. Extrarenal mechanism controls plasma levels, shifting potassium from the extracellular to the intracellular, whereas renal mechanism concerns with body balance and is influenced by potassium intake and its urinary excretion. In this article, we discuss the functions, isoforms, and localization of P2C-type ATPases, describe some of their modulators, and discuss their implications in some diseases. PMID:25631710

  7. Production, Purification, and Capsid Stability of Rhinovirus C Types

    PubMed Central

    Griggs, Theodor F.; Bochkov, Yury A.; Nakagome, Kazuyuki; Palmenberg, Ann C.; Gern, James E.

    2015-01-01

    The Rhinovirus C (RV-C) were discovered in 2006 and these agents are an important cause of respiratory morbidity. Little is known about their biology. RV-C15 (C15) can be produced by transfection of recombinant viral RNA into cells and subsequent purification over a 30% sucrose cushion, even though yields and infectivity of other RV-C genotypes with this protocol are low. The goal of this study was to determine whether poor RV-C yields were due to capsid instability, and moreover, to develop a robust protocol suitable for the purification of many RV-C types. Capsid stability assays indicated that virions of RV-C41 (refractory to purification) have similar tolerance for osmotic and temperature stress as RV-A16 (purified readily), although C41 is more sensitive to low pH. Modification to the purification protocol by removing detergent increased the yield of RV-C. Addition of nonfat dry milk to the sucrose cushion increased the virus yield but sacrificed purity of the viral suspension. Analysis of virus distribution following centrifugation indicated that the majority of detectable viral RNA (vRNA) was found in pellets refractory to resuspension. Reduction of the centrifugal force with commiserate increase in spin-time improved the recovery of RV-C for both C41 and C2. Transfection of primary lung fibroblasts (WisL cells) followed by the modified purification protocol further improved yields of infectious C41 and C2. Described herein is a higher-yield purification protocol suitable for RV-C types refractory to the standard purification procedure. The findings suggest that aggregation-adhesion problems rather than capsid instability influence RV-C yield during purification. PMID:25724434

  8. A profile of protein-protein interaction: Crystal structure of a lectin-lectin complex.

    PubMed

    Surya, Sukumaran; Abhilash, Joseph; Geethanandan, Krishnan; Sadasivan, Chittalakkottu; Haridas, Madhathilkovilakathu

    2016-06-01

    Proteins may utilize complex networks of interactions to create/proceed signaling pathways of highly adaptive responses such as programmed cell death. Direct binary interactions study of proteins may help propose models for protein-protein interaction. Towards this goal we applied a combination of thermodynamic kinetics and crystal structure analyses to elucidate the complexity and diversity in such interactions. By determining the heat change on the association of two galactose-specific legume lectins from Butea monosperma (BML) and Spatholobus parviflorus (SPL) belonging to Fabaceae family helped to compute the binding equilibrium. It was extended further by X-ray structural analysis of BML-SPL binary complex. In order to chart the proteins interacting mainly through their interfaces, identification of the nature of forces which stabilized the association of the lectin-lectin complex was examined. Comprehensive analysis of the BMLSPL complex by isothermal titration calorimetry and X-ray crystal structure threw new light on the lectin-lectin interactions suggesting of their use in diverse areas of glycobiology. PMID:26945504

  9. Algal lectins as promising biomolecules for biomedical research.

    PubMed

    Singh, Ram Sarup; Thakur, Shivani Rani; Bansal, Parveen

    2015-02-01

    Lectins are natural bioactive ubiquitous proteins or glycoproteins of non-immune response that bind reversibly to glycans of glycoproteins, glycolipids and polysaccharides possessing at least one non-catalytic domain causing agglutination. Some of them consist of several carbohydrate-binding domains which endow them with the properties of cell agglutination or precipitation of glycoconjugates. Lectins are rampant in nature from plants, animals and microorganisms. Among microorganisms, algae are the potent source of lectins with unique properties specifically from red algae. The demand of peculiar and neoteric biologically active substances has intensified the developments on isolation and biomedical applications of new algal lectins. Comprehensively, algal lectins are used in biomedical research for antiviral, antinociceptive, anti-inflammatory, anti-tumor activities, etc. and in pharmaceutics for the fabrication of cost-effective protein expression systems and nutraceutics. In this review, an attempt has been made to collate the information on various biomedical applications of algal lectins. PMID:23855360

  10. ON VASCULAR STENOSIS, RESTENOSIS AND MANNOSE BINDING LECTIN.

    PubMed

    Kahlow, Barbara Stadler; Nery, Rodrigo Araldi; Skare, Thelma L; Ribas, Carmen Australia Paredes Marcondes; Ramos, Gabriela Piovezani; Petisco, Roberta Dombroski

    2016-03-01

    Mannose binding lectin is a lectin instrumental in the innate immunity. It recognizes carbohydrate patterns found on the surface of a large number of pathogenic micro-organisms, activating the complement system. However, this protein seems to increase the tissue damage after ischemia. In this paper is reviewed some aspects of harmful role of the mannose binding lectin in ischemia/reperfusion injury. PMID:27120743

  11. 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. .

  12. ON VASCULAR STENOSIS, RESTENOSIS AND MANNOSE BINDING LECTIN

    PubMed Central

    KAHLOW, Barbara Stadler; NERY, Rodrigo Araldi; SKARE, Thelma L; RIBAS, Carmen Australia Paredes Marcondes; RAMOS, Gabriela Piovezani; PETISCO, Roberta Dombroski

    2016-01-01

    Mannose binding lectin is a lectin instrumental in the innate immunity. It recognizes carbohydrate patterns found on the surface of a large number of pathogenic micro-organisms, activating the complement system. However, this protein seems to increase the tissue damage after ischemia. In this paper is reviewed some aspects of harmful role of the mannose binding lectin in ischemia/reperfusion injury. PMID:27120743

  13. 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.

  14. Fine carbohydrate recognition of Euphorbia milii lectin.

    PubMed

    Irazoqui, Fernando J; Vozari-Hampe, Magdolna M; Lardone, Ricardo D; Villarreal, Marcos A; Sendra, Victor G; Montich, Guillermo G; Trindade, Vera M; Clausen, Henrik; Nores, Gustavo A

    2005-10-14

    Glycans are key structures involved in biological processes such as cell attachment, migration, and invasion. Information coded on cell-surface glycans is frequently deciphered by proteins, as lectins, that recognize specific carbohydrate topology. Here, we describe the fine carbohydrate specificity of Euphorbia milii lectin (EML). Competitive assays using various sugars showed that GalNAc was the strongest inhibitor, and that the hydroxyl axial position of C4 and acetamido on C2 of GalNAc are critical points of EML recognition. A hydrophobic locus adjacent to GalNAc is also an important region for EML binding. Direct binding assays of EML revealed a stereochemical requirement for a structure adjacent to terminal GalNAc, showing that GalNAc residue is a necessary but not sufficient condition for EML interaction. The capacity of EML to bind epithelial tumor cells makes it a potentially useful tool for study of some over-expressed GalNAc glycoconjugates. PMID:16122701

  15. Determinants of quaternary association in legume lectins

    PubMed Central

    Brinda, K.V.; Mitra, Nivedita; Surolia, Avadhesha; Vishveshwara, Saraswathi

    2004-01-01

    It is well known that the sequence of amino acids in proteins code for its tertiary structure. It is also known that there exists a relationship between sequence and the quaternary structure of proteins. The question addressed here is whether the nature of quaternary association can be predicted from the sequence, similar to the three-dimensional structure prediction from the sequence. The class of proteins called legume lectins is an interesting model system to investigate this problem, because they have very high sequence and tertiary structure homology, with diverse forms of quaternary association. Hence, we have used legume lectins as a probe in this paper to (1) gain novel insights about the relationship between sequence and quaternary structure; (2) identify the sequence motifs that are characteristic of a given type of quaternary association; and (3) predict the quaternary association from the sequence motif. PMID:15215518

  16. Mitochondria and the Lectin Pathway of Complement*

    PubMed Central

    Brinkmann, Christel R.; Jensen, Lisbeth; Dagnæs-Hansen, Frederik; Holm, Ida E.; Endo, Yuichi; Fujita, Teizo; Thiel, Steffen; Jensenius, Jens C.; Degn, Søren E.

    2013-01-01

    Mitochondria, the powerhouses of our cells, are remnants of a eubacterial endosymbiont. Notwithstanding the evolutionary time that has passed since the initial endosymbiotic event, mitochondria have retained many hallmarks of their eubacterial origin. Recent studies have indicated that during perturbations of normal homeostasis, such as following acute trauma leading to massive necrosis and release of mitochondria, the immune system might mistake symbiont for enemy and initiate an inappropriate immune response. The innate immune system is the first line of defense against invading microbial pathogens, and as such is the primary suspect in the recognition of mitochondria-derived danger-associated molecular patterns and initiation of an aberrant response. Conversely, innate immune mechanisms are also central to noninflammatory clearance of innocuous agents. Here we investigated the role of a central humoral component of innate immunity, the lectin pathway of complement, in recognition of mitochondria in vitro and in vivo. We found that the soluble pattern recognition molecules, mannan-binding lectin (MBL), L-ficolin, and M-ficolin, were able to recognize mitochondria. Furthermore, MBL in complex with MBL-associated serine protease 2 (MASP-2) was able to activate the lectin pathway and deposit C4 onto mitochondria, suggesting that these molecules are involved either in homeostatic clearance of mitochondria or in induction of untoward inflammatory reactions. We found that following mitochondrial challenge, C3 was consumed in vivo in the absence of overt inflammation, indicating a potential role of complement in noninflammatory clearance of mitochondria. Thus, we report here the first indication of involvement of the lectin pathway in mitochondrial immune handling. PMID:23378531

  17. Concept, strategy and realization of lectin-based glycan profiling.

    PubMed

    Hirabayashi, Jun

    2008-08-01

    Lectins are a diverse group of carbohydrate-binding proteins. Each lectin has its own specificity profile. It is believed that lectins exist in all living organisms that produce glycans. From a practical viewpoint, lectins have been used extensively in biochemical fields including proteomics due to their usefulness as detection and enrichment tools for specific glycans. Nevertheless, they have often been underestimated as probes, especially compared with antibodies, because of their low affinity and broad specificity. However, together with the concept of glycomics, such properties of lectins are now considered to be suitable for the task of 'profiling' in order to cover a wider range of ligands. Recently there has been rapid movement in the field of proteomics aimed at the investigation of glycan-related biomarkers. This is partly because of limitations of the present approach of simply following changes in protein-level expression, without paying sufficient attention to the fact and effects of glycosylation. The trend is reflected in the frequent use of lectins in the contexts of glycoprotein enrichment and glycan profiling. However, there are many aspects to be considered in using lectins, which differ considerably from antibodies. In this article, the author, as a developer of two unique methodologies, frontal affinity chromatography (FAC) and the lectin microarray, describes critical points concerning the use of lectins, together with the concept, strategy and means to achieve advances in these emerging glycan profiling technologies. PMID:18390573

  18. The Cysteine-Rich Domain of the Macrophage Mannose Receptor Is a Multispecific Lectin That Recognizes Chondroitin Sulfates a and B and Sulfated Oligosaccharides of Blood Group Lewisa and Lewisx Types in Addition to the Sulfated N-Glycans of Lutropin

    PubMed Central

    Leteux, Christine; Chai, Wengang; Loveless, R. Wendy; Yuen, Chun-Ting; Uhlin-Hansen, Lars; Combarnous, Yves; Jankovic, Mila; Maric, Svetlana C.; Misulovin, Ziva; Nussenzweig, Michel C.; Ten Feizi

    2000-01-01

    The mannose receptor (MR) is an endocytic protein on macrophages and dendritic cells, as well as on hepatic endothelial, kidney mesangial, tracheal smooth muscle, and retinal pigment epithelial cells. The extracellular portion contains two types of carbohydrate-recognition domain (CRD): eight membrane-proximal C-type CRDs and a membrane-distal cysteine-rich domain (Cys-MR). The former bind mannose-, N-acetylglucosamine-, and fucose-terminating oligosaccharides, and may be important in innate immunity towards microbial pathogens, and in antigen trapping for processing and presentation in adaptive immunity. Cys-MR binds to the sulfated carbohydrate chains of pituitary hormones and may have a role in hormonal clearance. A second feature of Cys-MR is binding to macrophages in marginal zones of the spleen, and to B cell areas in germinal centers which may help direct MR-bearing cells toward germinal centers during the immune response. Here we describe two novel classes of carbohydrate ligand for Cys-MR: chondroitin-4 sulfate chains of the type found on proteoglycans produced by cells of the immune system, and sulfated blood group chains. We further demonstrate that Cys-MR interacts with cells in the spleen via the binding site for sulfated carbohydrates. Our data suggest that the three classes of sulfated carbohydrate ligands may variously regulate the trafficking and function of MR-bearing cells. PMID:10748230

  19. Tomato lectin histochemistry for microglial visualization.

    PubMed

    Villacampa, Nàdia; Almolda, Beatriz; González, Berta; Castellano, Bernardo

    2013-01-01

    The use of different lectins for the study of microglial cells in the central nervous system (CNS) is a valuable tool that has been extensively used in the last years for the selective staining of this glial cell population, not only in normal physiological conditions, but also in a wide range of pathological situations where the normal homeostasis of the parenchyma is disturbed. In this chapter we accurately describe the methodology for the selective labelling of microglial cells by using the tomato lectin (TL), a protein lectin obtained from Lycopersicum esculentum with specific affinity for poly-N-acetyl lactosamine sugar residues which are found on the plasma membrane and in the cytoplasm of microglia. Here we describe how to perform this technique on vibratome, frozen, and paraffin sections for optical microscopy, as well as for transmission electron microscopy (TEM) studies. Using this methodology it is possible to visualize amoeboid microglia in the developing brain, ramified microglia in the adult, and activated/reactive microglia in the experimentally damaged brain. In addition, as TL also recognized sugar residues in endothelial cells, this technique is very useful for the study of the relationship established between microglia and the CNS vasculature. PMID:23813385

  20. Role of mannose-binding lectin in intestinal homeostasis and fungal elimination.

    PubMed

    Choteau, L; Parny, M; François, N; Bertin, B; Fumery, M; Dubuquoy, L; Takahashi, K; Colombel, J-F; Jouault, T; Poulain, D; Sendid, B; Jawhara, S

    2016-05-01

    Mannose-binding lectin (MBL) is a soluble lectin of the innate immune system that is produced by the liver and secreted into the circulation where it activates the lectin complement pathway, enhances phagocytosis of microorganisms by leukocytes, and modulates inflammation. MBL can recognize patterns on the surface of different pathogens, including Candida albicans. Our aims were to investigate whether MBL is expressed in the gut epithelium and to examine its effect on the modulation of intestinal inflammation and C. albicans elimination. Using reverse transcriptase-PCR, MBL transcripts were highly expressed in different parts of the mouse gut. MBL expression was also detected by immunoblotting and immunolocalization in response to C. albicans colonization of the gut; the highest expression of MBL was detected in the stomach. Blocking MBL by administering mannans to mice increased C. albicans colonization. MBL-deficient mice had a higher level of colonization than wild-type mice. Dextran sodium sulfate-induced colitis promoted C. albicans dissemination to the kidneys and lungs of MBL-deficient mice. MBL-deficient mice exhibited elevated expression of interleukin (IL)-17, IL-23, dectin-1, and Toll-like receptor-4. This study shows that MBL expression is induced in the gut in response to C. albicans sensing and is required for intestinal homeostasis and host defense against C. albicans. PMID:26442658

  1. Lectin-functionalized microchannels for characterizing pluripotent cells and early differentiation

    PubMed Central

    Vickers, Dwayne A. L.; Kulik, Michael; Hincapie, Marina; Hancock, William S.; Dalton, Stephen; Murthy, Shashi K.

    2012-01-01

    Embryonic stem (ES) cells are capable of proliferating and differentiating to form cells of the three embryonic germ layers, namely, endoderm, mesoderm, and ectoderm. The utilization of human ES cell derivatives requires the ability to direct differentiation to specific lineages in defined, efficient, and scalable systems. Better markers are needed to identify early differentiation. Lectins have been reported as an attractive alternative to the common stem cell markers. They have been used to identify, characterize, and isolate various cell subpopulations on the basis of the presentation of specific carbohydrate groups on the cell surface. This article demonstrates how simple adhesion assays in lectin-coated microfluidic channels can provide key information on the interaction of lectins with ES and definitive endoderm cells and thereby track early differentiation. The microfluidic approach incorporates both binding strength and cell surface receptor density, whereas traditional flow cytometry only incorporates the latter. Both approaches are examined and shown to be complementary with the microfluidic approach providing more biologically relevant information. PMID:22712033

  2. Lectin-functionalized microchannels for characterizing pluripotent cells and early differentiation.

    PubMed

    Vickers, Dwayne A L; Kulik, Michael; Hincapie, Marina; Hancock, William S; Dalton, Stephen; Murthy, Shashi K

    2012-06-01

    Embryonic stem (ES) cells are capable of proliferating and differentiating to form cells of the three embryonic germ layers, namely, endoderm, mesoderm, and ectoderm. The utilization of human ES cell derivatives requires the ability to direct differentiation to specific lineages in defined, efficient, and scalable systems. Better markers are needed to identify early differentiation. Lectins have been reported as an attractive alternative to the common stem cell markers. They have been used to identify, characterize, and isolate various cell subpopulations on the basis of the presentation of specific carbohydrate groups on the cell surface. This article demonstrates how simple adhesion assays in lectin-coated microfluidic channels can provide key information on the interaction of lectins with ES and definitive endoderm cells and thereby track early differentiation. The microfluidic approach incorporates both binding strength and cell surface receptor density, whereas traditional flow cytometry only incorporates the latter. Both approaches are examined and shown to be complementary with the microfluidic approach providing more biologically relevant information. PMID:22712033

  3. Lysophosphatidic acid stimulates thrombomodulin lectin-like domain shedding in human endothelial cells

    SciTech Connect

    Wu Hualin; Lin ChiIou; Huang Yuanli; Chen, Pin-Shern; Kuo, Cheng-Hsiang; Chen, Mei-Shing; Wu, G.C.-C.; Shi, G.-Y.; Yang, H.-Y.; Lee Hsinyu

    2008-02-29

    Thrombomodulin (TM) is an anticoagulant glycoprotein highly expressed on endothelial cell surfaces. Increased levels of soluble TM in circulation have been widely accepted as an indicator of endothelial damage or dysfunction. Previous studies indicated that various proinflammatory factors stimulate TM shedding in various cell types such as smooth muscle cells and epithelial cells. Lysophosphatidic acid (LPA) is a bioactive lipid mediator present in biological fluids during endothelial damage or injury. In the present study, we first observed that LPA triggered TM shedding in human umbilical vein endothelial cells (HUVECs). By Cyflow analysis, we showed that the LPA-induced accessibility of antibodies to the endothelial growth factor (EGF)-like domain of TM is independent of matrix metalloproteinases (MMPs), while LPA-induced TM lectin-like domain shedding is MMP-dependent. Furthermore, a stable cell line expressing TM without its lectin-like domain exhibited a higher cell proliferation rate than a stable cell line expressing full-length TM. These results imply that LPA induces TM lectin-like domain shedding, which might contribute to the exposure of its EGF-like domain for EGF receptor (EGFR) binding, thereby stimulating subsequent cell proliferation. Based on our findings, we propose a novel mechanism for the exposure of TM EGF-like domain, which possibly mediates LPA-induced EGFR transactivation.

  4. Development of the chick thymus microenvironment: a study by lectin histochemistry.

    PubMed Central

    Fernandez, J G; Sanchez, A J; Melcon, C; Chamorro, C A; Garcia, C; Paz, P

    1994-01-01

    The microenvironment of the chick thymus has been examined during development using lectin histochemistry. We have assayed WGA, Con A, RCA-I and TPA on thymic sections from 13, 15, 17 and 19 d chick embryos and 0, 5, 10 and 15 d chicks. All lectins were immunoperoxidase and colloidal gold-conjugated for transmission electron microscope observations. WGA labelled both the cortical and medullary thymic stroma at all the stages analysed. An intense reaction to WGA was observed in the subcortical region from stage 18 embryos to 5 d chicks. On the other hand, WGA did not stain medullary areas of the chick thymus. Con A lectin detected several cell clusters of stromal cells and thymocytes in cortical regions. These clusters could represent a lymphostromal complex with which Con A receptors are associated, probably in relation to cell adhesion. The residues detected by RCA were distributed both in stromal cells and thymocytes of the developing chick thymus. There was an increase of the reaction to RCA between the 19 d embryos and the 5 d chicks. This increase might be interpreted in terms of the secretion of thymic humoral factors at these stages. The thymic stromal cells stained with immunoperoxidase conjugated-TPA showed a reticular pattern in the medulla. There is a possibility that the fucosyl residues may be expressed in the Ia antigen as has previously been suggested in other species. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:7512541

  5. Toxoplasma gondii micronemal protein MIC1 is a lactose-binding lectin.

    PubMed

    Lourenço, E V; Pereira, S R; Faça, V M; Coelho-Castelo, A A; Mineo, J R; Roque-Barreira, M C; Greene, L J; Panunto-Castelo, A

    2001-07-01

    Host cell invasion by Toxoplasma gondii is a multistep process with one of the first steps being the apical release of micronemal proteins that interact with host receptors. We demonstrate here that micronemal protein 1 (MIC1) is a lactose-binding lectin. MIC1 and MIC4 were recovered in the lactose-eluted (Lac(+)) fraction on affinity chromatography on immobilized lactose of the soluble antigen fraction from tachyzoites of the virulent RH strain. MIC1 and MIC4 were both identified by N-terminal microsequencing. MIC4 was also identified by sequencing cDNA clones isolated from an expression library following screening with mouse polyclonal anti-60/70 kDa (Lac(+) proteins) serum. This antiserum localized the Lac(+) proteins on the apical region of T. gondii tachyzoites by confocal microscopy. The Lac(+) fraction induced hemagglutination (mainly type A human erythrocytes), which was inhibited by beta-galactosides (3 mM lactose and 12 mM galactose) but not by up to 100 mM melibiose (alpha-galactoside), fucose, mannose, or glucose or 0.2 mg/ml heparin. The lectin activity of the Lac(+) preparation was attributed to MIC1, because blotted MIC1, but not native MIC4, bound human erythrocyte type A and fetuin. The copurification of MIC1 and MIC4 may have been due to their association, as reported by others. These data suggest that MIC1 may act through its lectin activity during T. gondii infection. PMID:11447133

  6. Invasion of insect cells by Spiroplasma citri involves spiralin relocalization and lectin/glycoconjugate-type interactions.

    PubMed

    Duret, Sybille; Batailler, Brigitte; Dubrana, Marie-Pierre; Saillard, Colette; Renaudin, Joël; Béven, Laure; Arricau-Bouvery, Nathalie

    2014-07-01

    Spiroplamas are helical, cell wall-less bacteria belonging to the Class Mollicutes, a group of microorganisms phylogenetically related to low G+C, Gram-positive bacteria. Spiroplasma species are all found associated with arthropods and a few, including Spiroplasma citri are pathogenic to plant. Thus S. citri has the ability to colonize cells of two very distinct hosts, the plant and the insect vector. While spiroplasmal factors involved in transmission by the leafhopper Circulifer haematoceps have been identified, their specific contribution to invasion of insect cells is poorly understood. In this study we provide evidence that the lipoprotein spiralin plays a major role in the very early step of cell invasion. Confocal laser scanning immunomicroscopy revealed a relocalization of spiralin at the contact zone of adhering spiroplasmas. The implication of a role for spiralin in adhesion to insect cells was further supported by adhesion assays showing that a spiralin-less mutant was impaired in adhesion and that recombinant spiralin triggered adhesion of latex beads. We also showed that cytochalasin D induced changes in the surface-exposed glycoconjugates, as inferred from the lectin binding patterns, and specifically improved adhesion of S. citri wild-type but not of the spiralin-less mutant. These results indicate that cytochalasin D exposes insect cell receptors of spiralin that are masked in untreated cells. In addition, competitive adhesion assays with lectins strongly suggest spiralin to exhibit glycoconjugate binding properties similar to that of the Vicia villosa agglutinin (VVA) lectin. PMID:24438161

  7. Multiplexed detection of lectins using integrated glycan-coated microring resonators.

    PubMed

    Ghasemi, Farshid; Hosseini, Ehsan Shah; Song, Xuezheng; Gottfried, David S; Chamanzar, Maysamreza; Raeiszadeh, Mehrsa; Cummings, Richard D; Eftekhar, Ali A; Adibi, Ali

    2016-06-15

    We present the systematic design, fabrication, and characterization of a multiplexed label-free lab-on-a-chip biosensor using silicon nitride (SiN) microring resonators. Sensor design is addressed through a systematic approach that enables optimizing the sensor according to the specific noise characteristics of the setup. We find that an optimal 6 dB undercoupled resonator consumes 40% less power in our platform to achieve the same limit-of-detection as the conventional designs using critically coupled resonators that have the maximum light-matter interaction. We lay out an optimization framework that enables the generalization of our method for any type of optical resonator and noise characteristics. The device is fabricated using a CMOS-compatible process, and an efficient swabbing lift-off technique is introduced for the deposition of the protective oxide layer. This technique increases the lift-off quality and yield compared to common lift-off methods based on agitation. The complete sensor system, including microfluidic flow cell and surface functionalization with glycan receptors, is tested for the multiplexed detection of Aleuria Aurantia Lectin (AAL) and Sambucus Nigra Lectin (SNA). Further analysis shows that the sensor limit of detection is 2 × 10(-6) RIU for bulk refractive index, 1 pg/mm(2) for surface-adsorbed mass, and ∼ 10 pM for the glycan/lectins studied here. PMID:26826877

  8. 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. PMID:12862436

  9. Subcellular site of lectin synthesis in developing rice embryos

    PubMed Central

    Stinissen, Hetty M.; Peumans, Willy J.; Chrispeels, Maarten J.

    1984-01-01

    Embryos of developing rice (Oryza sativa L. cv. Koshihikari) caryopses which actively synthesize lectin were labelled with [35S]cysteine for different times and newly synthesized rice lectin was isolated by affinity chromatography. Gel filtration of embryo extracts on Sepharose-4B indicated that a large portion of the labelled lectin was associated with the particulate fraction. Experiments with detergent indicated that this lectin was sequestered within organelles. When extracts of pulse-labelled embryos were fractionated on isopycnic sucrose gradients, this detergent-released lectin banded in the same density-region as the endoplasmic reticulum (ER) marker enzyme NADH-cytochrome c reductase. Both radioactivity in rice lectin and the enzyme activity shifted towards a higher density in the presence of 2 mM Mg acetate, indicating that the labelled lectin was associated with the rough ER. The ER-bound lectin could be chased from this organelle when tissue was incubated in unlabelled cysteine following a 1 h pulse of labelled cysteine. Radioactivity chased out of the ER with a half-life of ˜4 h and accumulated in the soluble fraction. In the ER the lectin was present as a polypeptide with mol. wt. 23 000, while in the soluble fraction it occurred as polypeptides with mol. wt. 18 000, 10 000 and 8000. The rice lectin in the ER is capable of binding carbohydrates since it binds readily to the affinity gels. It is associated into dimers with an approximate mol. wt. of 46 000. The results show that newly synthesized rice lectin is transiently sequestered within the ER before further transport and processing take place. ImagesFig. 5. PMID:16453545

  10. High-level expression and characterization of a glycosylated human cementum protein 1 with lectin activity.

    PubMed

    Romo-Arévalo, Enrique; Arzate, Higinio; Montoya-Ayala, Gonzalo; Rodríguez-Romero, Adela

    2016-01-01

    This work aims to contribute to the knowledge of human cementum protein 1 (CEMP1), its conformational characteristics and influence during the biomineralization process. The results revealed that hrCEMP1 expressed in Pichia pastoris is a 2.4% glycosylated, thermostable protein which possesses a molecular mass of 28 770 Da. The circular dichroism spectrum indicated a secondary structure content of 28.6% of alpha-helix, 9.9% of beta-sheet and 61.5% of random-coil forms. Biological activity assays demonstrated that hrCEMP1 nucleates and regulates hydroxyapatite crystal growth. Hereby, it is demonstrated for the first time that CEMP1 has a (C-type) lectin-like activity and specifically recognizes mannopyranoside. The information produced by this biochemical and structural characterization may contribute to understand more fully the biological functions of CEMP1. PMID:26763148

  11. Lectin-mediated effects on bone resorption in vitro: a morphological and functional study

    SciTech Connect

    Popoff, S.N.

    1986-01-01

    Lectins have been used to study the structure and function of a variety of cells and tissues. The authors used 4 different lectins, concanavalin A (con A), wheat germ agglutinin (WGA), soybean agglutinin (SBA) and peanut agglutinin (PNA) as in vitro biological probes to study the osteoclast, a multinucleated bone cell that is widely accepted as the primary effector cell responsible for normal bone resorption. They evaluated the effects of each of these lectins on osteoclastic bone resorbing activity and then examined mechanisms that may be responsible for the activation and/or inhibition of osteoclastic activity. Using con A and hemocyanin, a marker molecule used to visualize cell-bound con A via scanning electron microscopy, they demonstrated that osteoclasts have specific con A binding sites on their cell surface. They conducted a series of /sup 45/Ca bone release assays demonstrating that con A has a dose-dependent biphasic effect on bone resorption; stimulation at low concentrations and inhibition at higher concentrations. The findings suggest that the specificity of lectin binding to cell surface receptors may play an important role in the induction of altered cell function. Recently, cells of the mononuclear phagocyte system have been proposed as surrogates of less readily available osteoclasts. They used a macrophage-devitalized bone culture system to evaluate the effects of con A and SBA on the attachment of macrophages to bone and their subsequent functional activity. The results showed that con A, but not SBA, alters the morphology and function of macrophages on a devitalized bone surface. The results support the hypothesis that certain, specific saccharides regulate the interaction between macrophages and bone.

  12. The apical membrane of intestinal brush cells possesses a specialised, but species-specific, composition of glycoconjugates--on-section and in vivo lectin labelling in rats, guinea-pigs and mice.

    PubMed

    Gebert, A; al-Samir, K; Werner, K; Fassbender, S; Gebhard, A

    2000-05-01

    Brush cells are specialised epithelial cells that are assumed to represent chemoreceptors of the digestive tract. They comprise a small population of the epithelial cells lining the intestine, possess a unique ultrastructure and, in many aspects, resemble the receptor cells of taste buds. To characterise glycoconjugates possibly involved in a sensory function, we investigated brush cells in the small intestine of three species using lectin histochemistry in confocal light and thin-section electron microscopy. Brush cells of rats were selectively labelled by the sialic acid-specific lectin Maackia amurensis agglutinin, those of guinea-pigs by the D-galactose-specific lectin Bandeiraea simplicifolia agglutinin, isolectin B4 and those of mice by the L-fucose-specific lectin Ulex europaeus agglutinin lectin I. Lectin binding sites were consistently located in the glycocalyx of the apical membrane and in that of cytoplasmic vesicles. In vivo lectin labelling revealed that the glycoconjugates of the apical membrane are accessible under physiological conditions, that brush cells do not endocytose and that they probably possess a high membrane turnover rate. The results show that specialisations exist in the composition of glycoconjugates forming the glycocalyx of brush cells in all species investigated. The presence of brush cell-specific glycoconjugates would be in accordance with the current hypothesis of a receptive function of brush cells. Differences in the specific glycosylation patterns among rats, guinea-pigs and mice indicate that species-specific adaptations exist. PMID:10883398

  13. Lectins from opportunistic bacteria interact with acquired variable-region glycans of surface immunoglobulin in follicular lymphoma

    PubMed Central

    Schneider, Dunja; Dühren-von Minden, Marcus; Alkhatib, Alabbas; Setz, Corinna; van Bergen, Cornelis A. M.; Benkißer-Petersen, Marco; Wilhelm, Isabel; Villringer, Sarah; Krysov, Sergey; Packham, Graham; Zirlik, Katja; Römer, Winfried; Buske, Christian; Stevenson, Freda K.; Veelken, Hendrik

    2015-01-01

    B-cell antigen receptor (BCR) expression is a key feature of most B-cell lymphomas, but the mechanisms of BCR signal induction and the involvement of autoantigen recognition remain unclear. In follicular lymphoma (FL) B cells, BCR expression is retained despite a chromosomal translocation that links the antiapoptotic gene BCL2 to the regulatory elements of immunoglobulin genes, thereby disrupting 1 heavy-chain allele. A remarkable feature of FL-BCRs is the acquisition of potential N-glycosylation sites during somatic hypermutation. The introduced glycans carry mannose termini, which create potential novel binding sites for mannose-specific lectins. Here, we investigated the effect of N-linked variable-region glycosylation for BCR interaction with cognate antigen and with lectins of different origins. N-glycans were found to severely impair BCR specificity and affinity to the initial cognate antigen. In addition, we found that lectins from Pseudomonas aeruginosa and Burkholderia cenocepacia bind and stimulate FL cells. Human exposure to these bacteria can occur by contact with soil and water. In addition, they represent opportunistic pathogens in susceptible hosts. Understanding the role of bacterial lectins might elucidate the pathogenesis of FL and establish novel therapeutic approaches. PMID:25784678

  14. Fluorinated Carbohydrates as Lectin Ligands: 19F-Based Direct STD Monitoring for Detection of Anomeric Selectivity

    PubMed Central

    Ribeiro, João P.; Diercks, Tammo; Jiménez-Barbero, Jesús; André, Sabine; Gabius, Hans-Joachim; Cañada, Francisco Javier

    2015-01-01

    The characterization of the binding of reducing carbohydrates present as mixtures of anomers in solution to a sugar recepor (lectin) poses severe difficulties. In this situation, NMR spectroscopy enables the observation of signals for each anomer in the mixture by applying approaches based on ligand observation. Saturation transfer difference (STD) NMR allows fast and efficient screening of compound mixtures for reactivity to a receptor. Owing to the exceptionally favorable properties of 19F in NMR spectroscopy and the often complex 1H spectra of carbohydrates, 19F-containing sugars have the potential to be turned into versatile sensors for recognition. Extending the recently established 1H → 1H STDre19F-NMR technique, we here demonstrate its applicability to measure anomeric selectivity of binding in a model system using the plant lectin concanavalin A (ConA) and 2-deoxy-2-fluoro-d-mannose. Indeed, it is also possible to account for the mutual inhibition between the anomers on binding to the lectin by means of a kinetic model. The monitoring of 19F-NMR signal perturbation disclosed the relative activities of the anomers in solution and thus enabled the calculation of their binding affinity towards ConA. The obtained data show a preference for the α anomer that increases with temperature. This experimental approach can be extended to others systems of biomedical interest by testing human lectins with suitably tailored glycan derivatives. PMID:26580665

  15. Dehydration of model membranes induced by lectins from Ricinus communis and Viscum album.

    PubMed

    Pohl, P; Saparov, S M; Pohl, E E; Evtodienko, V Y; Agapov, I I; Tonevitsky, A G

    1998-12-01

    The effects of ribosome-inactivating proteins (RIPs) from Ricinus communis and from Viscum album on the water permeability, Pf, and the surface dielectric constant, epsilon, of model membranes were studied. Pf was calculated from microelectrode measurements of the ion concentration distribution in the immediate vicinity of a planar membrane, and epsilon was obtained from the fluorescence of dansyl phosphatidylethanolamine incorporated into unilamellar vesicles. Pf and epsilon of fully saturated phosphatidylcholine membranes were affected only in the presence of a lectin receptor (monosialoganglioside, GM1) in the bilayer. It is suggested that the membrane area occupied by clustered lectin-receptor complexes is markedly less permeable to water. Protein binding to the receptor was not a prelude for hydrophobic lipid-protein interactions when the membranes were formed from a mixture of natural phospholipids with a high content of unsaturated fatty acids. These membranes, characterized by a high initial water permeability, were found to interact with the RIPs unspecifically. From a decrease of both Pf and epsilon it was concluded that not only water partitioning but also protein adsorption correlates with looser packing of polyunsaturated lipids at the lipid-water interface. PMID:9826608

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  17. Modulation of glycan detection on specific glycoproteins by lectin multimerization

    PubMed Central

    Cao, Zheng; Partyka, Katie; McDonald, Mitchell; Brouhard, Elizabeth; Hincapie, Marina; Brand, Randall E.; Hancock, William S.; Haab, Brian B.

    2013-01-01

    Improved methods for studying glycans could spur significant advances in the understanding and application of glycobiology. The use of affinity reagents such as lectins and glycan-binding antibodies is a valuable complement to methods involving mass spectrometry and chromatography. Many lectins, however, are not useful as analytic tools due to low affinity in vitro. As an approach to increasing lectin avidity to targeted glycans, we tested the use of lectin multimerization. Several biotinylated lectins were linked together through streptavidin interactions. The binding of certain lectins for purified glycoproteins and glycoproteins captured directly out of biological solutions was increased using multimerization, resulting in the detection of lower concentrations of glycoprotein than possible using monomeric detection. The analysis of glycoproteins in plasma samples showed that the level of binding enhancement through multimerization was not equivalent across patient samples. Wheat germ agglutinin (WGA) reactive glycans on fibronectin and thrombospondin-5 were preferentially bound by multimers in pancreatic cancer patient samples relative to control samples, suggesting a cancer-associated change in glycan density that could be detected only through lectin multimerization. This strategy could lead to the more sensitive and informative detection of glycans in biological samples and a broader spectrum of lectins that are useful as analytical reagents. PMID:23286506

  18. Modulation of glycan detection on specific glycoproteins by lectin multimerization.

    PubMed

    Cao, Zheng; Partyka, Katie; McDonald, Mitchell; Brouhard, Elizabeth; Hincapie, Marina; Brand, Randall E; Hancock, William S; Haab, Brian B

    2013-02-01

    Improved methods for studying glycans could spur significant advances in the understanding and application of glycobiology. The use of affinity reagents such as lectins and glycan-binding antibodies is a valuable complement to methods involving mass spectrometry and chromatography. Many lectins, however, are not useful as analytic tools due to low affinity in vitro. As an approach to increasing lectin avidity to targeted glycans, we tested the use of lectin multimerization. Several biotinylated lectins were linked together through streptavidin interactions. The binding of certain lectins for purified glycoproteins and glycoproteins captured directly out of biological solutions was increased using multimerization, resulting in the detection of lower concentrations of glycoprotein than possible using monomeric detection. The analysis of glycoproteins in plasma samples showed that the level of binding enhancement through multimerization was not equivalent across patient samples. Wheat germ agglutinin (WGA) reactive glycans on fibronectin and thrombospondin-5 were preferentially bound by multimers in pancreatic cancer patient samples relative to control samples, suggesting a cancer-associated change in glycan density that could be detected only through lectin multimerization. This strategy could lead to the more sensitive and informative detection of glycans in biological samples and a broader spectrum of lectins that are useful as analytical reagents. PMID:23286506

  19. 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

  20. Glycan profiling of endometrial cancers using lectin microarray.

    PubMed

    Nishijima, Yoshihiro; Toyoda, Masashi; Yamazaki-Inoue, Mayu; Sugiyama, Taro; Miyazawa, Masaki; Muramatsu, Toshinari; Nakamura, Kyoko; Narimatsu, Hisashi; Umezawa, Akihiro; Mikami, Mikio

    2012-10-01

    Cell surface glycans change during the process of malignant transformation. To characterize and distinguish endometrial cancer and endometrium, we performed glycan profiling using an emerging modern technology, lectin microarray analysis. The three cell lines, two from endometrial cancers [well-differentiated type (G1) and poorly differentiated type (G3)] and one from normal endometrium, were successfully categorized into three independent groups by 45 lectins. Furthermore, in cancer cells, a clear difference between G1 and G3 type was observed for the glycans recognized with six lectins, Ulex europaeus agglutinin I (UEA-I), Sambucus sieboldiana agglutinin (SSA), Sambucus nigra agglutinin (SNA), Trichosanthes japonica agglutinin I (TJA-I), Amaranthus caudatus agglutinin (ACA), and Bauhinia purpurea lectin (BPL). The lectin microarray analysis using G3 type tissues demonstrated that stage I and stage III or IV were distinguished depending on signal pattern of three lectins, Dolichos biflorus agglutinin (DBA), BPL, and ACA. In addition, the analysis of the glycans on the ovarian cancer cells showed that only anticancer drug-sensitive cell lines had almost no activities to specific three lectins. Glycan profiling by the lectin microarray may be used to assess the characteristics of tumors and potentially to predict the success of chemotherapy treatment. PMID:22957961

  1. 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...

  2. 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

    2015-08-01

    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

  3. Assessment of lectin inactivation by heat and digestion.

    PubMed

    Pusztai, A; Grant, G

    1998-01-01

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

  4. Latent Ice Recrystallization Inhibition Activity in Nonantifreeze Proteins: Ca2+-Activated Plant Lectins and Cation-Activated Antimicrobial Peptides

    PubMed Central

    2015-01-01

    Organisms living in polar regions have evolved a series of antifreeze (glyco) proteins (AFGPs) to enable them to survive by modulating the structure of ice. These proteins have huge potential for use in cellular cryopreservation, ice-resistant surfaces, frozen food, and cryosurgery, but they are limited by their relatively low availability and questions regarding their mode of action. This has triggered the search for biomimetic materials capable of reproducing this function. The identification of new structures and sequences capable of inhibiting ice growth is crucial to aid our understanding of these proteins. Here, we show that plant c-type lectins, which have similar biological function to human c-type lectins (glycan recognition) but no sequence homology to AFPs, display calcium-dependent ice recrystallization inhibition (IRI) activity. This IRI activity can be switched on/off by changing the Ca2+ concentration. To show that more (nonantifreeze) proteins may exist with the potential to display IRI, a second motif was considered, amphipathicity. All known AFPs have defined hydrophobic/hydrophilic domains, rationalizing this choice. The cheap, and widely used, antimicrobial Nisin was found to have cation-dependent IRI activity, controlled by either acid or addition of histidine-binding ions such as zinc or nickel, which promote its amphipathic structure. These results demonstrate a new approach in the identification of antifreeze protein mimetic macromolecules and may help in the development of synthetic mimics of AFPs. PMID:26407233

  5. Latent Ice Recrystallization Inhibition Activity in Nonantifreeze Proteins: Ca2+-Activated Plant Lectins and Cation-Activated Antimicrobial Peptides.

    PubMed

    Mitchell, Daniel E; Gibson, Matthew I

    2015-10-12

    Organisms living in polar regions have evolved a series of antifreeze (glyco) proteins (AFGPs) to enable them to survive by modulating the structure of ice. These proteins have huge potential for use in cellular cryopreservation, ice-resistant surfaces, frozen food, and cryosurgery, but they are limited by their relatively low availability and questions regarding their mode of action. This has triggered the search for biomimetic materials capable of reproducing this function. The identification of new structures and sequences capable of inhibiting ice growth is crucial to aid our understanding of these proteins. Here, we show that plant c-type lectins, which have similar biological function to human c-type lectins (glycan recognition) but no sequence homology to AFPs, display calcium-dependent ice recrystallization inhibition (IRI) activity. This IRI activity can be switched on/off by changing the Ca2+ concentration. To show that more (nonantifreeze) proteins may exist with the potential to display IRI, a second motif was considered, amphipathicity. All known AFPs have defined hydrophobic/hydrophilic domains, rationalizing this choice. The cheap, and widely used, antimicrobial Nisin was found to have cation-dependent IRI activity, controlled by either acid or addition of histidine-binding ions such as zinc or nickel, which promote its amphipathic structure. These results demonstrate a new approach in the identification of antifreeze protein mimetic macromolecules and may help in the development of synthetic mimics of AFPs. PMID:26407233

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

    PubMed Central

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

    1996-01-01

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

  7. Mitogenic effect of Parkia speciosa seed lectin on human lymphocytes.

    PubMed

    Suvachittanont, W; Jaranchavanapet, P

    2000-12-01

    Mitogenic activity of a lectin, purified from Parkia speciosa seeds, on the isolated peripheral blood lymphocytes taken from normal blood donors and patients with esophageal carcinoma was examined using [3H]thymidine incorporation. The lectin increases the incorporation of [3H]thymidine into DNA of human lymphocytes. The activity of the lectin increased as its concentration was increased and then declined once the concentration passed an optimum point. The stimulant effect was also expressed using a proliferation index (PI): the ratio of [3H]thymidine incorporated into lymphocytes in the presence and absence of the lectin. The mitogenic activity of the lectin is comparable to those of the known T-cell mitogens, such as concanavalin A, phytohaemagglutinin, and pokeweed mitogen. Only slightly less responsiveness was observed in the case of lymphocytes from esophageal cancer compared to lymphocytes from normal donors. PMID:11199124

  8. Use of amaranthus leucocarpus lectin to differentiate cervical dysplasia (CIN).

    PubMed

    Santaella-Verdejo, Arturo; Gallegos, Belem; Pérez-Campos, Eduardo; Hernández, Pedro; Zenteno, Edgar

    2007-01-01

    Alterations in O-glycosylation of proteins in cell surfaces can originate disorder in cellular function, as well as in cell transformation and tumoral differentiation. In this work, we investigate changes in O-glycosylation in cervical intraepithelial dysplasia (CIN) at different stages of differentiation (CIN I, CIN II, and CIN III) using lectins specific for O-glycosidically linked glycans. Twenty cases with CIN I, CIN II, and CIN III dysplasias each, and 20 normal cases were studied by lectin histochemistry and evaluated under optical microscopy. The lectins from Glycine max and Griffonia simplicifolia showed no differences in their recognition pattern among the different CIN stages and normal tissue. Dolichos Biflorus lectin recognized CIN I dysplasia. Lectin from Amaranthus leucocarpus showed increased reactivity in the presence of CIN II dysplasia, compared with CIN I and CIN III. These results suggest that subtle modifications in the O-glycosylation pattern could be considered in diagnosis or prognosis of cervical precancerous stages. PMID:17516251

  9. Biotoxicity assays for fruiting body lectins and other cytoplasmic proteins.

    PubMed

    Künzler, Markus; Bleuler-Martinez, Silvia; Butschi, Alex; Garbani, Mattia; Lüthy, Peter; Hengartner, Michael O; Aebi, Markus

    2010-01-01

    Recent studies suggest that a specific class of fungal lectins, commonly referred to as fruiting body lectins, play a role as effector molecules in the defense of fungi against predators and parasites. Hallmarks of these fungal lectins are their specific expression in reproductive structures, fruiting bodies, and/or sclerotia and their synthesis on free ribosomes in the cytoplasm. Fruiting body lectins are released upon damage of the fungal cell and bind to specific carbohydrate structures of predators and parasites, which leads to deterrence, inhibition of growth, and development or even killing of these organisms. Here, we describe assays to assess the toxicity of such lectins and other cytoplasmic proteins toward three different model organisms: the insect Aedes aegypti, the nematode Caenorhabditis elegans, and the amoeba Acanthamoeba castellanii. All three assays are based on heterologous expression of the examined proteins in the cytoplasm of Escherichia coli and feeding of these recombinant bacteria to omnivorous and bacterivorous organisms. PMID:20816208

  10. Human blood dendritic cell subsets exhibit discriminative pattern recognition receptor profiles

    PubMed Central

    Lundberg, Kristina; Rydnert, Frida; Greiff, Lennart; Lindstedt, Malin

    2014-01-01

    Dendritic cells (DCs) operate as the link between innate and adaptive immunity. Their expression of pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs) and C-type lectin receptors (CLRs), enables antigen recognition and mediates appropriate immune responses. Distinct subsets of human DCs have been identified; however their expression of PRRs is not fully clarified. Expressions of CLRs by DC subpopulations, in particular, remain elusive. This study aimed to identify and compare PRR expressions on human blood DC subsets, including CD1c+, CD141+ and CD16+ myeloid DCs and CD123+ plasmacytoid DCs, in order to understand their capacity to recognize different antigens as well as their responsiveness to PRR-directed targeting. Whole blood was obtained from 13 allergic and six non-allergic individuals. Mononuclear cells were purified and multi-colour flow cytometry was used to assess the expression of 10 CLRs and two TLRs on distinct DC subsets. PRR expression levels were shown to differ between DC subsets for each PRR assessed. Furthermore, principal component analysis and random forest test demonstrated that the PRR profiles were discriminative between DC subsets. Interestingly, CLEC9A was expressed at lower levels by CD141+ DCs from allergic compared with non-allergic donors. The subset-specific PRR expression profiles suggests individual responsiveness to PRR-targeting and supports functional specialization. PMID:24444310

  11. Human blood dendritic cell subsets exhibit discriminative pattern recognition receptor profiles.

    PubMed

    Lundberg, Kristina; Rydnert, Frida; Greiff, Lennart; Lindstedt, Malin

    2014-06-01

    Dendritic cells (DCs) operate as the link between innate and adaptive immunity. Their expression of pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs) and C-type lectin receptors (CLRs), enables antigen recognition and mediates appropriate immune responses. Distinct subsets of human DCs have been identified; however their expression of PRRs is not fully clarified. Expressions of CLRs by DC subpopulations, in particular, remain elusive. This study aimed to identify and compare PRR expressions on human blood DC subsets, including CD1c(+) , CD141(+) and CD16(+) myeloid DCs and CD123(+) plasmacytoid DCs, in order to understand their capacity to recognize different antigens as well as their responsiveness to PRR-directed targeting. Whole blood was obtained from 13 allergic and six non-allergic individuals. Mononuclear cells were purified and multi-colour flow cytometry was used to assess the expression of 10 CLRs and two TLRs on distinct DC subsets. PRR expression levels were shown to differ between DC subsets for each PRR assessed. Furthermore, principal component analysis and random forest test demonstrated that the PRR profiles were discriminative between DC subsets. Interestingly, CLEC9A was expressed at lower levels by CD141(+) DCs from allergic compared with non-allergic donors. The subset-specific PRR expression profiles suggests individual responsiveness to PRR-targeting and supports functional specialization. PMID:24444310

  12. 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. PMID:27237111

  13. Nutritional evaluation of lectin-free soybeans for poultry.

    PubMed

    Douglas, M W; Parsons, C M; Hymowitz, T

    1999-01-01

    This study evaluated the nutritional value of raw lectin-free soybeans in comparison with raw Kunitz trypsin inhibitor-free soybeans, raw conventional soybeans, and commercial heat processed soybean meal (SBM). Analyzed lectin values (milligrams per kilogram) were 7.2, 7.1, and < 0.00015 for the Kunitz-free, conventional, and lectin-free soybeans, respectively. Three experiments were conducted using New Hampshire x Columbian male chicks fed 23% CP dextrose-soybean diets from 8 to 17 d of age. Growth performance of chicks fed lectin-free soybeans was greater (P < 0.05) than that of chicks fed raw conventional soybeans in all three experiments. However, performance of chicks fed lectin-free soybeans was lower than that of chicks fed Kunitz-free soybeans or SBM. The SBM yielded weight gains and feed efficiencies that were much higher than those observed from any of the raw soybeans. True amino acid digestibility and TMEn of the lectin-free and conventional soybeans were determined using the precision-fed cecectomized rooster assay. Seven roosters were crop-intubated with 30 g of soybeans and excreta were collected for 48 h. Digestibility coefficients of most amino acids for lectin-free soybeans were 5 to 8 percentage units higher than those for conventional soybeans, but the differences were not significant (P > 0.05). Likewise, the TMEn for lectin-free soybeans was 11% higher than that for raw conventional soybeans (3.577 vs 3.227 kcal/g DM) but the difference was not significant (P > 0.05). The results of this study indicate that the nutritional value of raw lectin-free soybeans is greater than raw conventional soybeans but is less than raw Kunitz-free soybeans and SBM, suggesting that trypsin inhibitor is a greater antinutritional factor than lectins. PMID:10023754

  14. 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

  15. Lectin and lectin-related proteins in lima bean (Phaseolus lunatus L.) seeds: biochemical and evolutionary studies.

    PubMed

    Sparvoli, F; Lanave, C; Santucci, A; Bollini, R; Lioi, L

    2001-03-01

    Lectin-related polypeptides are a class of defence proteins found in seeds of Phaseolus species. In Lima bean (P. lunatus), these proteins and their genes have been well characterized in the Andean morphotype, which represents one of the two gene pools of this species. To study the molecular evolution of the lectin family in Lima bean we characterized the polypeptides belonging to this multigene family and cloned the genes belonging to the Mesoamerican gene pool. The latter gene pool contains components similar to those of the Andean pool, namely: an amylase inhibitor-like (AIL), an arcelin-like (ARL) lectin and the less abundant Lima bean lectin (LBL). These proteins originate from an ancestor gene of the lectin type which duplicated to yield the lectin gene and the progenitor of ARL and AIL. In this species. ARL represents an evolutionary intermediate form that precedes AIL. Phylogenetic analysis supports an Andean origin for Lima bean. The molecular evolutionary studies were extended to the genes of common bean and demonstrated that true lectin genes and the ancestor of lectin-related genes are the result of a duplication event that occurred before speciation. Lima and common bean followed different evolutionary pathways and in the latter species a second duplication event occurred that gave rise, in Mesoamerican wild genotypes, to arcelin genes. PMID:11414617

  16. Pattern-Recognition Receptors and Gastric Cancer

    PubMed Central

    Castaño-Rodríguez, Natalia; Kaakoush, Nadeem O.; Mitchell, Hazel M.

    2014-01-01

    Chronic inflammation has been associated with an increased risk of several human malignancies, a classic example being gastric adenocarcinoma (GC). Development of GC is known to result from infection of the gastric mucosa by Helicobacter pylori, which initially induces acute inflammation and, in a subset of patients, progresses over time to chronic inflammation, gastric atrophy, intestinal metaplasia, dysplasia, and finally intestinal-type GC. Germ-line encoded receptors known as pattern-recognition receptors (PRRs) are critical for generating mature pro-inflammatory cytokines that are crucial for both Th1 and Th2 responses. Given that H. pylori is initially targeted by PRRs, it is conceivable that dysfunction within genes of this arm of the immune system could modulate the host response against H. pylori infection, and subsequently influence the emergence of GC. Current evidence suggests that Toll-like receptors (TLRs) (TLR2, TLR3, TLR4, TLR5, and TLR9), nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) (NOD1, NOD2, and NLRP3), a C-type lectin receptor (DC-SIGN), and retinoic acid-inducible gene (RIG)-I-like receptors (RIG-I and MDA-5), are involved in both the recognition of H. pylori and gastric carcinogenesis. In addition, polymorphisms in genes involved in the TLR (TLR1, TLR2, TLR4, TLR5, TLR9, and CD14) and NLR (NOD1, NOD2, NLRP3, NLRP12, NLRX1, CASP1, ASC, and CARD8) signaling pathways have been shown to modulate the risk of H. pylori infection, gastric precancerous lesions, and/or GC. Further, the modulation of PRRs has been suggested to suppress H. pylori-induced inflammation and enhance GC cell apoptosis, highlighting their potential relevance in GC therapeutics. In this review, we present current advances in our understanding of the role of the TLR and NLR signaling pathways in the pathogenesis of GC, address the involvement of other recently identified PRRs in GC, and discuss the potential implications of PRRs in GC immunotherapy

  17. Functional and physical molecular size of the chicken hepatic lectin determined by radiation inactivation and sedimentation equilibrium analysis

    SciTech Connect

    Steer, C.J.; Osborne, J.C. Jr.; Kempner, E.S. )

    1990-03-05

    Radiation inactivation and sedimentation equilibrium analysis were used to determine the functional and physical size of the chicken hepatic membrane receptor that binds N-acetylglucosamine-terminated glycoproteins. Purified plasma membranes from chicken liver were irradiated with high energy electrons and assayed for 125I-agalactoorosomucoid binding. Increasing the dose of ionizing radiation resulted in a monoexponential decay in binding activity due to a progressive loss of binding sites. The molecular mass of the chicken lectin, determined in situ by target analysis, was 69,000 +/- 9,000 Da. When the same irradiated membranes were solubilized in Brij 58 and assayed, the binding protein exhibited a target size of 62,000 +/- 4,000 Da; in Triton X-100, the functional size of the receptor was 85,000 +/- 10,000 Da. Sedimentation equilibrium measurements of the purified binding protein yielded a lower limit molecular weight of 79,000 +/- 7,000. However, the solubilized lectin was detected as a heterogeneous population of oligomers with molecular weights as high as 450,000. Addition of calcium or calcium plus N-acetylglucosamine decreased the higher molecular weight species, but the lower limit molecular weights remained invariant. Similar results were determined when the chicken lectin was solubilized in Brij 58, C12E9, or 3-((3-cholamidopropyl)dimethylammonio)-1-propane-sulfonic acid (CHAPS). Results from the present study suggest that in the plasma membrane, the functional species of the chicken hepatic lectin exists as a trimer. However, in detergent solution, the purified receptor forms a heterogeneous population of irreversible oligomers that exhibit binding activity proportional to size.

  18. Closed state-coupled C-type inactivation in BK channels.

    PubMed

    Yan, Jiusheng; Li, Qin; Aldrich, Richard W

    2016-06-21

    Ion channels regulate ion flow by opening and closing their pore gates. K(+) channels commonly possess two pore gates, one at the intracellular end for fast channel activation/deactivation and the other at the selectivity filter for slow C-type inactivation/recovery. The large-conductance calcium-activated potassium (BK) channel lacks a classic intracellular bundle-crossing activation gate and normally show no C-type inactivation. We hypothesized that the BK channel's activation gate may spatially overlap or coexist with the C-type inactivation gate at or near the selectivity filter. We induced C-type inactivation in BK channels and studied the relationship between activation/deactivation and C-type inactivation/recovery. We observed prominent slow C-type inactivation/recovery in BK channels by an extreme low concentration of extracellular K(+) together with a Y294E/K/Q/S or Y279F mutation whose equivalent in Shaker channels (T449E/K/D/Q/S or W434F) caused a greatly accelerated rate of C-type inactivation or constitutive C-inactivation. C-type inactivation in most K(+) channels occurs upon sustained membrane depolarization or channel opening and then recovers during hyperpolarized membrane potentials or channel closure. However, we found that the BK channel C-type inactivation occurred during hyperpolarized membrane potentials or with decreased intracellular calcium ([Ca(2+)]i) and recovered with depolarized membrane potentials or elevated [Ca(2+)]i Constitutively open mutation prevented BK channels from C-type inactivation. We concluded that BK channel C-type inactivation is closed state-dependent and that its extents and rates inversely correlate with channel-open probability. Because C-type inactivation can involve multiple conformational changes at the selectivity filter, we propose that the BK channel's normal closing may represent an early conformational stage of C-type inactivation. PMID:27298368

  19. Galatrox is a C-type lectin in Bothrops atrox snake venom that selectively binds LacNAc-terminated glycans and can induce acute inflammation

    PubMed Central

    Sartim, Marco A; Riul, Thalita B; Del Cistia-Andrade, Camillo; Stowell, Sean R; Arthur, Connie M; Sorgi, Carlos A; Faccioli, Lucia H; Cummings, Richard D; Dias-Baruffi, Marcelo; Sampaio, Suely V

    2014-01-01

    Previous studies indicate that snake venom contains glycan-binding proteins (GBPs), although the binding specificity and biological activities of many of these GBPs is unclear. Here we report our studies on the glycan binding specificity and activities of galatrox, a Bothrops atrox snake venom-derived GBP. Glycan microarray analysis indicates that galatrox binds most strongly to glycans expressing N-acetyllactosamine (LacNAc), with a significant preference for Galβ1-4GlcNAcβ over Galβ1-3GlcNAcβ compounds. Galatrox also bound immobilized laminin, a LacNAc-dense extracellular matrix component, suggesting that this GBP can bind LacNAc-bearing glycoproteins. As several endogenous mammalian GBPs utilize a similar binding LacNAc binding preference to regulate neutrophil and monocyte activity, we hypothesized that galatrox may mediate B. atrox toxicity through regulation of leukocyte activity. Indeed, galatrox bound neutrophils and promoted leukocyte chemotaxis in a carbohydrate-dependent manner. Similarly, galatrox administration into the mouse peritoneal cavity induced significant neutrophil migration and the release of pro-inflammatory cytokines IL-1α and IL-6. Exposure of bone marrow-derived macrophages to galatrox induced generation of pro-inflammatory mediators IL-6, TNF-α, and keratinocyte-derived chemokine. This signaling by galatrox was mediated via its carbohydrate recognition domain by activation of the TLR4-mediated MyD88-dependent signaling pathway. These results indicate that galatrox has pro-inflammatory activity through its interaction with LacNAc-bearing glycans on neutrophils, macrophages and extracellular matrix proteins and induce the release of pro-inflammatory mediators. PMID:24973254

  20. The C-Type Lectin OCILRP2 Costimulates EL4 T Cell Activation via the DAP12-Raf-MAP Kinase Pathway

    PubMed Central

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

    2014-01-01

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

  1. Agglucetin, a tetrameric C-type lectin-like venom protein, regulates endothelial cell survival and promotes angiogenesis by activating integrin {alpha}v{beta}3 signaling

    SciTech Connect

    Wang, W.-J.

    2008-05-02

    Agglucetin, a platelet glycoprotein (GP)Ib binding protein from Formosan Agkistrodon acutus (A. acutus) venom, could sustain human umbilical vein endothelial cell (HUVEC) proliferation and HUVEC adhering to immobilized agglucetin showed extensive spreading, which was strongly abrogated by integrin antagonists 7E3 and triflavin. Flow cytometric analyses confirmed the expression of GPIb complex on HUVEC is absent and fluorescein isothiocyanate (FITC)-agglucetin binds to HUVEC in a dose-dependent and saturable manner. Furthermore, native agglucetin specifically and dose-dependently inhibited the binding of FITC-23C6, an anti-{alpha}v{beta}3 monoclonal antibody (mAb), but not antibodies against {alpha}2 and {alpha}5, toward HUVEC and purified {alpha}v{beta}3 also bound to immobilized agglucetin-{beta} in a dose-dependent manner. Moreover, agglucetin exhibited a pro-angiogenic effect in vitro, as well as the focal adhesion kinase (FAK)-associated signaling molecules responsible for HUVEC activation were initiated by agglucetin. In conclusion, agglucetin, acting as a survival factor, promotes endothelial adhesion and angiogenesis by triggering {alpha}v{beta}3 signaling through FAK/phosphatidylinositol 3-kinase (PI3K)/Akt pathway.

  2. 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. PMID:18579103

  3. Lectin reactivities as intermediate biomarkers in premalignant colorectal epithelium.

    PubMed

    Boland, C R; Martin, M A; Goldstein, I J

    1992-01-01

    Normal colonic epithelial cells undergo maturation as they traverse the crypt to the lumenal surface. The binding of lectins to goblet cell mucins and other glycoconjugates changes as the cells migrate and differentiate. Additional stepwise modifications in glycoconjugate expression occur in premalignant and malignant neoplasms that may be detected by lectin binding studies. The lectins Dolichos biflorus agglutinin (DBA) and soybean agglutinin (SBA) have been developed as markers of differentiation in normal-appearing colonic epithelium. Using a quantitative biometric system to score tissues, reduced levels of lectin binding have been found in rectal tissue from patients with familial adenomatous polyposis (FAP) and hereditary nonpolyposis colorectal cancer. The lectin Amaranthus caudatus agglutinin (ACA) binds to a cytoplasmic glycoconjugate expressed at the base of the colonic crypt and serves as a possible proliferation marker in the distal, but not proximal, colon. ACA binding increases in tandem with increased levels of proliferation (using BrdU incorporation) in neoplastic tissues. Binding by the peanut lectin (PNA) occurs late in the adenoma-to-carcinoma sequence--in larger adenomas and in cancers--and serves as a marker of advancing neoplasia. Lectins identify the stepwise changes that occur during normal differentiation, proliferation and in advancing neoplasia. By selecting the appropriate probe, biomarkers may be developed for early, intermediate, and late events in colorectal cancer. PMID:1469891

  4. Cloning and characterization of root-specific barley lectin

    SciTech Connect

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

    1989-09-01

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

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

    SciTech Connect

    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 of 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 fluorescently

  6. Purification, some properties of a D-galactose-binding leaf lectin from Erythrina indica and further characterization of seed lectin.

    PubMed

    Konozy, Emadeldin H E; Mulay, Ranjana; Faca, Vitor; Ward, Richard John; Greene, Lewis Joel; Roque-Barriera, Maria Cristina; Sabharwal, Sushma; Bhide, Shobhana V

    2002-10-01

    Lectin from a leaf of Erythrina indica was isolated by affinity chromatography on Lactamyl-Seralose 4B. Lectin gave a single band in polyacrylamide gel electrophoresis (PAGE). In SDS-gel electrophoresis under reducing and non-reducing conditions Erythrina indica leaf lectin (EiLL) split into two bands with subunit molecular weights of 30 and 33 kDa, whereas 58 kDa was obtained for the intact lectin by gel filtration on Sephadex G-100. EiLL agglutinated all human RBC types, with a slight preference for the O blood group. Lectin was found to be a glycoprotein with a neutral sugar content of 9.5%. The carbohydrate specificity of lectin was directed towards D-galactose and its derivatives with pronounced preference for lactose. EiLL had pH optima at pH 7.0; above and below this pH lectin lost sugar-binding capability rapidly. Lectin showed broad temperature optima from 25 to 50 degrees C; however, at 55 degrees C EiLL lost more than 90% of its activity and at 60 degrees C it was totally inactivated. The pI of EiLL was found to be 7.6. The amino acid analysis of EiLL indicated that the lectin was rich in acidic as well as hydrophobic amino acids and totally lacked cysteine and methionine. The N-terminal amino acids were Val-Glu-Thr-IIe-Ser-Phe-Ser-Phe-Ser-Glu-Phe-Glu-Ala-Gly-Asn-Asp-X-Leu-Thr-Gln-Glu-Gly-Ala-Ala-Leu-. Chemical modification studies of both EiLL and Erythrina indica seed lectin (EiSL) with phenylglyoxal, DEP and DTNB revealed an absence of arginine, histidine and cysteine, respectively, in or near the ligand-binding site of both lectins. Modification of tyrosine with NAI led to partial inactivation of EiLL and EiSL; however, total inactivation was observed upon NBS-modification of two tryptophan residues in EiSL. Despite the apparent importance of these tryptophan residues for lectin activity they did not seem to have a direct role in binding haptenic sugar as D-galactose did not protect lectin from inactivation by NBS. PMID:12504284

  7. Effects of lectin ingestion on animal growth and internal organs.

    PubMed

    Pusztai, A

    1998-01-01

    Lectins are essential and omnipresent plant constituents. As many foods are of plant origin, the daily ingestion of lectins by both humans and animals is appreciable. For example, in an ad hoc survey, 53 edible plants were shown to contain lectins and approx 30% of fresh and processed food regularly consumed by humans had significant hemagglutinating activity (1). The situation is potentially even more acute in animal nutrition because animal diet is less diverse than that of humans, and in most instances foodstuffs are not thoroughly heat-treated. This is particularly significant in the light of our finding a correlation between lectin activity and antinutritional effects (2). As in evolution, the mammalian gut has been regularly exposed to lectins, they must have played an important part in the development of the digestive system. Although based on experience, most overtly toxic plants have been eliminated from the diet, many plants with appreciable lectin content are still consumed because it has not been easy to relate growth retardation and antinutritional, mild allergic or other subclinical symptoms to the food consumed or a particular component of it. As some lectins are at least partially heat stable and most survive the passage through the gut in functionally and immunologically intact form, their interaction with the gut surface epithelium (3) can damage the gut at high dietary intakes and this may lead to digestive disorders/diseases in some instances. However, it is not generally appreciated that not all lectins are antinutrients and indeed some may have beneficial effects and be of potential value in nutritional practice. Accordingly, it is of considerable importance to establish whether a lectin has deleterious or potentially beneficial effects for mammals. Unfortunately at present there are no adequate in vitro methods to do this reliably and it is usually necessary to carry out in vivo animal feeding studies, despite their relatively cumbersome

  8. In vivo biosynthetic studies of the Dolichos biflorus seed lectin

    SciTech Connect

    Quinn, J.M.; Etzler, M.E. )

    1989-12-01

    The in vivo biosynthesis of the Dolichos biflorus seed lectin was studied by pulse-chase labeling experiments using ({sup 35}S)methionine and ({sup 14}C)glucosamine. These studies demonstrate that each of the two mature lectin subunit types are derived by the processing of separate glycosylated precursors. The appearance of the precursor to subunit I before the precursor to subunit II supports the possibility raised by previous studies that both subunit types of this lectin may originate from a single gene product.

  9. Mannan binding lectin attenuates double-stranded RNA-mediated TLR3 activation and innate immunity.

    PubMed

    Liu, Hongzhi; Zhou, Jia; Ma, Di; Lu, Xiao; Ming, Siqi; Shan, Guiqiu; Zhang, Xiaoyong; Hou, Jinlin; Chen, Zhengliang; Zuo, Daming

    2014-03-18

    Mannan binding lectin (MBL) functions as a pattern recognition molecule (PRM) which is able to initiate complement activation. Here, we characterize a previously unrecognized attribute of MBL as a double-stranded RNA (dsRNA) binding protein capable of modifying Toll like receptor 3 (TLR3) activation. MBL interacts with poly(I:C) and suppresses poly(I:C)-induced activation of TLR3 pathways and subsequent cytokine production. In addition, MBL binds to TLR3 directly. Surprisingly, disrupting the interaction between MBL and complement receptor 1 (CR1) or restraining the traffic of MBL to phagosome reversed the MBL limited TLR3 activation. We demonstrate the importance of MBL guided ligands intracellular localization, emphasizing the significance of understanding the dynamics of TLR agonists complexed with MBL or other PRMs inside the cell in immune defense. PMID:24530528

  10. Bacterial Isolation by Lectin-Modified Microengines

    PubMed Central

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

    2011-01-01

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

  11. Clec4A4 is a regulatory receptor for dendritic cells that impairs inflammation and T-cell immunity

    PubMed Central

    Uto, Tomofumi; Fukaya, Tomohiro; Takagi, Hideaki; Arimura, Keiichi; Nakamura, Takeshi; Kojima, Naoya; Malissen, Bernard; Sato, Katsuaki

    2016-01-01

    Dendritic cells (DCs) comprise several subsets that are critically involved in the initiation and regulation of immunity. Clec4A4/DC immunoreceptor 2 (DCIR2) is a C-type lectin receptor (CLR) exclusively expressed on CD8α− conventional DCs (cDCs). However, how Clec4A4 controls immune responses through regulation of the function of CD8α− cDCs remains unclear. Here we show that Clec4A4 is a regulatory receptor for the activation of CD8α− cDCs that impairs inflammation and T-cell immunity. Clec4a4−/−CD8α− cDCs show enhanced cytokine production and T-cell priming following Toll-like receptor (TLR)-mediated activation. Furthermore, Clec4a4−/− mice exhibit TLR-mediated hyperinflammation. On antigenic immunization, Clec4a4−/− mice show not only augmented T-cell responses but also progressive autoimmune pathogenesis. Conversely, Clec4a4−/− mice exhibit resistance to microbial infection, accompanied by enhanced T-cell responses against microbes. Thus, our findings highlight roles of Clec4A4 in regulation of the function of CD8α− cDCs for control of the magnitude and quality of immune response. PMID:27068492

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

    PubMed

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

    1994-03-01

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

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

    PubMed

    Work, Thierry M; Farah, Yael

    2014-03-01

    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. PMID:24518620

  14. An alternate high yielding purification method for Clitoria ternatea lectin.

    PubMed

    Naeem, Aabgeena; Ahmad, Ejaz; Khan, Rizwan Hasan

    2007-10-01

    In our previous publication we had reported the purification and characterization of Clitoria ternatea agglutinin from its seeds on fetuin CL agarose affinity column, designated CTA [A. Naeem, S. Haque, R.H. Khan. Protein J., 2007]. Since CTA binds beta-d-galactosides, this lectin can be used as valuable tool for glycobiology studies in biomedical and cancer research. So an attempt was made for a high yielding alternative purification method employing the use of asialofetuin CL agarose column for the above-mentioned lectin, designated CTL. The fetuin affinity purified agglutinin was found similar to asialofetuin affinity purified lectin in SDS pattern, HPLC and N-terminal sequence. The content of lectin was found to be 30mg/30g dry weight of pulse. The yield was 2.8% as compared to 0.3% obtained on fetuin column. The number of tryptophan and tyrosine estimated was four and six per subunit. PMID:17590430

  15. 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.

  16. Specific interaction of lectins with liposomes and monolayers bearing neoglycolipids.

    PubMed

    Faivre, Vincent; Costa, Maria de Lourdes; Boullanger, Paul; Baszkin, Adam; Rosilio, Véronique

    2003-10-01

    The interaction of three lectins (wheat germ, Ulex europaeus I, and Lotus tetragonolobus agglutinins: WGA, UEA-I and LTA) with either N-acetyl-D-glucosamine or L-fucose neoglycolipids incorporated into phospholipid monolayers and liposome bilayers was studied at the air/water interface and in bulk solution. The results show that for both systems studied, synthesized neoglycolipids were capable of binding their specific lectin and that, in general, the binding of lectins increased with the increase in the molar fraction of the saccharide derivative incorporated in either the monolayers or bilayers. However, whereas for UEA-I, molecular recognition was enhanced by a strong hydrophobic interaction, for WGA and LTA successful recognition was predominantly related to the distance between neighboring sugar groups. The observed lengthy adsorption times of these lectins onto their specific ligands were attributed to interfacial conformational changes occurring in the proteins upon their adsorption at the interfaces. PMID:14499473

  17. 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. PMID:27268207

  18. 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.

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

    PubMed Central

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

    2014-01-01

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

  20. Interactions between Rhizobia and Lectins of Lentil, Pea, Broad Bean, and Jackbean 1

    PubMed Central

    Wong, Peter P.

    1980-01-01

    A quantitative method was developed to measure the binding of fluorescent-labeled lentil (Lens esculenta Moench), pea (Pisum sativum L.), broad bean (Vicia faba L.), and jackbean (Canavalia ensiformis L., DC.) lectins to various Rhizobium strains. Lentil lectin bound to three of the five Rhizobium leguminosarum strains tested. The number of lentil lectin molecules bound per R. leguminosarum 128C53 cell was 2.1 × 104. Lentil lectin also bound to R. japonicum 61A133. Pea and broad bean lectins bound to only two of the five strains of R. leguminosarum, whereas concanavalin A (jackbean lectin) bound to all strains of R. leguminosarum, R. phaseoli, R. japonicum, and R. sp. tested. Since these four lectins have similar sugarbinding properties but different physical properties, the variation in bindings of these lectins to various Rhizobium strains indicates that binding of lectin to Rhizobium is determined not only by the sugar specificity of the lectin but also by its physical characteristics. The binding of lentil lectin and concanavalin A to R. leguminosarum 128C53 could be inhibited by glucose, fructose, and mannose. However, even at 150 millimolar glucose, about 15% of the binding remained. The binding of lentil lectin to R. japonicum 61A133 could be inhibited by glucose but not by galactose. It is concluded that the binding site of lentil lectin to R. japonicum is different from the binding site of soybean lectin to R. japonicum. PMID:16661328

  1. Over-expression of Multi-heme C-type Cytochromes

    SciTech Connect

    Shi, Liang; Lin, Chiann Tso; Markillie, Lye Meng; Squier, Thomas C.; Hooker, Brian S.

    2005-02-01

    ABSTRACT-Because they contain covalently attached hemes, c-type cytochromes, especially those with multi-heme, are difficult to over-express. The gram negative bacterium Shewanella oneidensis MR-1 has been successfully used for over-expression of multi-heme c-type cytochromes...

  2. 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. PMID:21478615

  3. Binding of various lectins during chondrogenesis in mouse limb buds.

    PubMed

    Zimmermann, B

    1986-01-01

    The binding of six different FITC-labelled lectins to cells and matrix was investigated during chondrogenesis in mouse limb buds from day 10 to 13 of development. In undifferentiated mesenchyme, concanavalin A and wheat germ agglutinin bound very strongly, whereas at later stages binding was decreased in the peripheral mesenchyme, but very strong in blastemata and cartilage. Phaseolus vulgaris lectin showed the same properties, but the decrease in the peripheral mesenchyme was less pronounced. Fucose-specific lotus A lectin showed no binding at all. Ricinus communis lectin bound preferentially to the blastemata, and the galactose-specific peanut lectin exhibited binding exclusively to the blastemata. Electron microscopic investigations of the binding of peroxidase-labelled peanut lectin revealed reaction product in the matrix and at cellular membranes only at later stages. Early blastemal cell condensations were negative. In vitro experiments on chondrogenesis in high density cultures showed no pronounced influence of beta-D-galactosides on cell differentiation and matrix production. PMID:2422680

  4. Antifungal activity of lectins against yeast of vaginal secretion

    PubMed Central

    Gomes, Bruno Severo; Siqueira, Ana Beatriz Sotero; de Cássia Carvalho Maia, Rita; Giampaoli, Viviana; Teixeira, Edson Holanda; Arruda, Francisco Vassiliepe Sousa; do Nascimento, Kyria Santiago; de Lima, Adriana Nunes; Souza-Motta, Cristina Maria; Cavada, Benildo Sousa; Porto, Ana Lúcia Figueiredo

    2012-01-01

    Lectins are carbohydrate-binding proteins of non-imune origin. This group of proteins is distributed widely in nature and they have been found in viruses, microorganisms, plants and animals. Lectins of plants have been isolated and characterized according to their chemical, physical-chemical, structural and biological properties. Among their biological activities, we can stress its fungicidal action. It has been previously described the effect of the lectins Dviol, DRL, ConBr and LSL obtained from the seeds of leguminous plants on the growth of yeasts isolated from vaginal secretions. In the present work the experiments were carried out in microtiter plates and the results interpreted by both methods: visual observations and a microplate reader at 530nm. The lectin concentrations varied from 0.5 to 256μg/mL, and the inoculum was established between 65-70% of trammitance. All yeast samples isolated from vaginal secretion were evaluated taxonomically, where were observed macroscopic and microscopic characteristics to each species. The LSL lectin did not demonstrate any antifungal activity to any isolate studied. The other lectins DRL, ConBr and DvioL, showed antifungal potential against yeast isolated from vaginal secretion. These findings offering offer a promising field of investigation to develop new therapeutic strategies against vaginal yeast infections, collaborating to improve women's health. PMID:24031889

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

    PubMed

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

    2015-11-01

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

  6. CD44 Antibody Inhibition of Macrophage Phagocytosis Targets Fcγ Receptor- and Complement Receptor 3-Dependent Mechanisms.

    PubMed

    Amash, Alaa; Wang, Lin; Wang, Yawen; Bhakta, Varsha; Fairn, Gregory D; Hou, Ming; Peng, Jun; Sheffield, William P; Lazarus, Alan H

    2016-04-15

    Targeting CD44, a major leukocyte adhesion molecule, using specific Abs has been shown beneficial in several models of autoimmune and inflammatory diseases. The mechanisms contributing to the anti-inflammatory effects of CD44 Abs, however, remain poorly understood. Phagocytosis is a key component of immune system function and can play a pivotal role in autoimmune states where CD44 Abs have shown to be effective. In this study, we show that the well-known anti-inflammatory CD44 Ab IM7 can inhibit murine macrophage phagocytosis of RBCs. We assessed three selected macrophage phagocytic receptor systems: Fcγ receptors (FcγRs), complement receptor 3 (CR3), and dectin-1. Treatment of macrophages with IM7 resulted in significant inhibition of FcγR-mediated phagocytosis of IgG-opsonized RBCs. The inhibition of FcγR-mediated phagocytosis was at an early stage in the phagocytic process involving both inhibition of the binding of the target RBC to the macrophages and postbinding events. This CD44 Ab also inhibited CR3-mediated phagocytosis of C3bi-opsonized RBCs, but it did not affect the phagocytosis of zymosan particles, known to be mediated by the C-type lectin dectin-1. Other CD44 Abs known to have less broad anti-inflammatory activity, including KM114, KM81, and KM201, did not inhibit FcγR-mediated phagocytosis of RBCs. Taken together, these findings demonstrate selective inhibition of FcγR and CR3-mediated phagocytosis by IM7 and suggest that this broadly anti-inflammatory CD44 Ab inhibits these selected macrophage phagocytic pathways. The understanding of the immune-regulatory effects of CD44 Abs is important in the development and optimization of therapeutic strategies for the potential treatment of autoimmune conditions. PMID:26944929

  7. NKG2A Complexed with CD94 Defines a Novel Inhibitory Natural Killer Cell Receptor

    PubMed Central

    Brooks, Andrew G.; Posch, Phillip E.; Scorzelli, Christopher J.; Borrego, Francisco; Coligan, John E.

    1997-01-01

    CD94 is a C-type lectin expressed by natural killer (NK) cells and a subset of T cells. Blocking studies using anti-CD94 mAbs have suggested that it is a receptor for human leukocyte antigen class I molecules. CD94 has recently been shown to be a 26-kD protein covalently associated with an unidentified 43-kD protein(s). This report shows that NKG2A, a 43-kD protein, is covalently associated with CD94 on the surface of NK cells. Cell surface expression of NKG2A is dependent on the association with CD94 as glycosylation patterns characteristic of mature proteins are found only in NKG2A that is associated with CD94. Analysis of NK cell clones showed that NKG2A was expressed in all NK cell clones whose CD16-dependent killing was inhibited by cross-linking CD94. The induction of an inhibitory signal is consistent with the presence of two immunoreceptor tyrosine-based inhibitory motifs (V/LXYXXL) on the cytoplasmic domain of NKG2A. Similar motifs are found on Ly49 and killer cell inhibitory receptors, which also transmit negative signals to NK cells. PMID:9034158

  8. A lectin from Sesbania aculeata (Dhaincha) roots and its possible function.

    PubMed

    Biswas, S; Saroha, A; Das, H R

    2009-03-01

    A lectin was isolated from the roots of Sesbania aculeata. This is a glucose specific lectin having 39 kDa subunit molecular weight. The expression of this lectin was found to be developmentally regulated and observed to be the highest in the second week. The lectin was purified by affinity chromatography using Sephadex G-50 and found to have 28% homology with Arabidopsis thaliana lectin-like protein (accession No. CAA62665). The lectin binds with lipopolysaccharide isolated from different rhizobial strains indicating the plants interaction with multiple rhizobial species. PMID:19364328

  9. Mechanisms involved in Korean mistletoe lectin-induced apoptosis of cancer cells

    PubMed Central

    Khil, Lee-Yong; Kim, Wi; Lyu, Suyun; Park, Won Bong; Yoon, Ji-Won; Jun, Hee-Sook

    2007-01-01

    AIM: To investigate the anti-cancer mechanisms of Korean mistletoe lectin (Viscum album coloratum agglutinin, VCA) using a human colon cancer cell line (COLO). METHODS: Cytotoxic effects of VCA on COLO cells were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in vitro and tumor-killing effects in vivo. To study the mechanisms involved, the expression of various pro-caspases, anti-apoptotic proteins, and death receptors was determined by western blot. To determine which death receptor is involved in VCA-induced apoptosis of COLO cells, cytotoxicity was examined by MTT assay after treatment with agonists or antagonists of death receptors. RESULTS: VCA killed COLO cells in a time- and dose-dependent manner and induced complete regression of tumors in nude mice transplanted with COLO cells. Treatment of COLO cells with VCA activated caspase-2, -3, -8, and -9 and decreased expression of anti-apoptotic molecules including receptor interacting protein, nuclear factor-κB, X-linked inhibitor of apoptosis protein, and Akt/protein kinase B. We then examined the involvement of death receptors in VCA-induced apoptosis. Only tumor necrosis factor receptor 1, among the death receptors examined, was involved in apoptosis of COLO cells, evidenced by inhibition of VCA-induced apoptosis and decreased activation of caspases, particularly caspase-8, by tumor necrosis factor receptor 1 antagonizing antibody. CONCLUSION: VCA-induced apoptotic COLO cell death is due to the activation of caspases and inhibition of anti-apoptotic proteins, in part through the tumor necrosis factor receptor 1 signaling pathway. PMID:17569116

  10. C-type natriuretic peptide in combination with sildenafil attenuates proliferation of rhabdomyosarcoma cells.

    PubMed

    Zenitani, Masahiro; Nojiri, Takashi; Uehara, Shuichiro; Miura, Koichi; Hosoda, Hiroshi; Kimura, Toru; Nakahata, Kengo; Miyazato, Mikiya; Okuyama, Hiroomi; Kangawa, Kenji

    2016-05-01

    Rhabdomyosarcoma (RMS) is a malignant mesenchymal tumor and the most common soft tissue sarcoma in children. Because of several complications associated with intensive multimodal therapies, including growth disturbance and secondary cancer, novel therapies with less toxicity are urgently needed. C-type natriuretic peptide (CNP), an endogenous peptide secreted by endothelial cells, exerts antiproliferative effects in multiple types of mesenchymal cells. Therefore, we investigated whether CNP attenuates proliferation of RMS cells. We examined RMS patient samples and RMS cell lines. All RMS clinical samples expressed higher levels of guanylyl cyclase B (GC-B), the specific receptor for CNP, than RMS cell lines. GC-B expression in RMS cells decreased with the number of passages in vitro. Therefore, GC-B stable expression lines were established to mimic clinical samples. CNP increased cyclic guanosine monophosphate (cGMP) levels in RMS cells in a dose-dependent manner, demonstrating the biological activity of CNP. However, because cGMP is quickly degraded by phosphodiesterases (PDEs), the selective PDE5 inhibitor sildenafil was added to inhibit its degradation. In vitro, CNP, and sildenafil synergistically inhibited proliferation of RMS cells stably expressing GC-B and decreased Raf-1, Mitogen-activated protein kinase kinase (MEK), and extracellular signal-regulated kinase (ERK) phosphorylation. These results suggested that CNP in combination with sildenafil exerts antiproliferative effects on RMS cells by inhibiting the Raf/MEK/ERK pathway. This regimen exerted synergistic effects on tumor growth inhibition without severe adverse effects in vivo such as body weight loss. Thus, CNP in combination with sildenafil represents a promising new therapeutic approach against RMS. PMID:26816265

  11. Lectin histochemistry of normal and neoplastic peripheral nerve sheath. 2. Lectin binding patterns of schwannoma and neurofibroma.

    PubMed

    Matsumura, K; Nakasu, S; Nioka, H; Handa, J

    1993-01-01

    Lectin binding patterns of 31 schwannomas and 6 neurofibromas were examined using 12 lectins, and the results were compared with those of normal peripheral nerves. Tumors obtained from 10 cases of neurofibromatosis and 4 recurrent schwannomas were included. Changes of glycoconjugates were observed in association with a neoplastic transformation of Schwann cells; Arachis hypogaea (PNA) staining after neuraminidase treatment seen in normal Schwann cells was reduced in schwannoma of Antoni type A, and bindings with Glycine max (SBA) and Helix pomatia (HPA) after sialic acid removal, which were not seen in normal Schwann cells, appeared in schwannoma cells. Intensities of staining of tumor cells with each lectin were higher in Antoni type B than those in Antoni type A. No differences in lectin binding patterns were observed between schwannomas in patients with neurofibromatosis or recurrent schwannomas and ordinary, primary schwannomas in patients without stigmata of neurofibromatosis. Lectin binding patterns of Schwann cells and perineurial cells in neurofibroma were almost similar to those in normal peripheral nerves with an exception of faint stain of Schwann cells with HPA after neuraminidase pretreatment. This result suggests differences in extent of differentiation between schwannoma cells and neoplastic Schwann cells in neurofibroma. Specific PNA binding to perineurial cells in neurofibroma indicates the significance of this lectin as a marker of these cells. PMID:8310811

  12. Lectin histochemistry of normal and neoplastic peripheral nerve sheath. 1. Lectin binding pattern of normal peripheral nerve in man.

    PubMed

    Matsumura, K; Nakasu, S; Nioka, H; Handa, J

    1993-01-01

    The binding patterns of lectins to normal peripheral nerves were examined. Twelve biotinylated lectins were used in this study; Canavalia ensiformis (Con A), Pisum sativum (PSA), Lens culinaris (LCA), Ricinus communis 1 (RCA-1), Arachis hypogaea (PNA), Glycine max (SBA), Sophora japonica (SJA), Bandeiraea simplicifolia 1 (BSL-1), Triticum vulgaris (WGA), succinylated WGA (s-WGA), Ulex europaeus 1 (UEA-1) and Helix pomatia (HPA). Cytoplasm of Schwann cells and perineurial cells was stained by Con A, PSA, LCA, s-WGA and WGA. PNA showed specific binding to perineurial cells, while after neuraminidase treatment stain with this lectin was demonstrated also in Schwann cells. Myelin sheaths were stained with fewer lectins. SBA and HPA with sialic acid removal rarely showed reactivity to the peripheral nerve structure in surgical specimens, in contrast to clear staining of Schwann cells, perineurial cells and myelin sheaths in autopsy specimens. The present study shows distinct lectin stainings of specific structures of the normal human peripheral nerves, and provides important basic information on the alterations of lectin binding patterns during pathological processes in the peripheral nerves. PMID:8310810

  13. Utilization of lectin-histochemistry in forensic neuropathology: lectin staining provides useful information for postmortem diagnosis in forensic neuropathology.

    PubMed

    Nishi, Katsuji; Tanegashima, Akio; Yamamoto, Yoshio; Ushiyama, Ikuko; Ikemoto, Keiko; Yamasaki, Shigeru; Nishimura, Akiyoshi; Rand, Steven; Brinkmann, Bernd

    2003-09-01

    We have investigated the deposition of glycoconjugates in human brain tissue with or without brain disorders. In this review we describe the application of lectin-histochemistry techniques to forensic neuropathology. Lectin staining is able to reveal several kinds of carbohydrate-related depositions in addition to the conventional degenerative changes including senile plaques, neurofibrillary tangles and corpora amylacea. The senile plaques and neurofibrillary tangles were clearly stained by Con A, PSA and GSI lectins, the corpora amylacea which is relevant to repeated brain hypoxia and mitochondrial damage was also easily detected by these and many other kinds of lectins. Amorphous spaces were detected around blood vessels and independently from blood vessels by lectin staining in the white matter from patients with brain disorders or severe edema. The white matter lesions were not considered relevant for forensic pathology, until a large group of cerebral white matter lesions were detected in the elderly with increasing frequency by modern neuro-imaging methods. The spherical deposits were newly detected by lectin staining in the molecular layer of the dentate gyrus of the hippocampal formation chiefly from patients with schizophrenia or cognitive dysfunctions. PMID:14568771

  14. Immunohistochemical and lectin histochemical studies on the developing olfactory organs of fetal camel.

    PubMed

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

    2015-07-01

    Little is known about the development of the olfactory organs of camel. In this study, prenatal development and neuronal differentiation of the vomeronasal organ (VNO) and the olfactory epithelium (OE) of the one-humped camel were studied by immunohistochemistry and lectin histochemistry. A neuronal marker, protein gene product (PGP) 9.5, but not a marker of fully differentiated olfactory receptor cells, olfactory marker protein, intensely labeled the olfactory receptor cells of the VNO and OE at 395 mm, 510 mm, and 530 mm fetal ages, indicating that the olfactory receptor cells are differentiated, but not fully matured both in the VNO and the OE. In 187 mm and 190 mm fetuses, PGP 9.5 yielded faint immunoreactive signals in the VNO, but not in the OE, although the presence of olfactory receptor cells were demonstrated in both tissues by intense WGA and LEL stainings. We conclude that the camel VNO and OE bear differentiated, but still immature receptor cells; in addition, the onset of neuronal differentiation seems to be somewhat earlier in the VNO than in the OE till half of the prenatal life. PMID:25950169

  15. Lectin Complement Protein Collectin 11 (CL-K1) and Susceptibility to Urinary Schistosomiasis

    PubMed Central

    Antony, Justin S.; Ojurongbe, Olusola; Kremsner, Peter G.; Velavan, Thirumalaisamy P.

    2015-01-01

    Background Urinary Schistosomiasis is a neglected tropical disease endemic in many sub Saharan -African countries. Collectin Kidney 1 (CL-K1, encoded by COLEC11 on chromosome 2p25.3), a member of the vertebrate C-type lectin super family, has recently been identified as pattern-recognition molecule (PRR) of the lectin complement pathway. CL-K1 is preferentially expressed in the kidneys, but also in other organs and it is considered to play a role in host defense to some infectious agents. Schistosome teguments are fucosylated and CL-K1 has, through its collagen-like domain, a high binding affinity to fucose. Methodology/Principal Findings We utilized a Nigerian study group consisting of 167 Schistosoma haematobium infected individuals and 186 matched healthy subjects, and investigated the contribution of CL-K1 deficiency and of COLEC11 polymorphisms to infection phenotype. Higher CL-K1 serum levels were associated with decreased risk of schistosome infection (Pcorr = 0.0004). CL-K1 serum levels were differentially distributed between the COLEC11 genotypes and haplotypes observed. The non-synonymous variant p.R216H was associated with the occurrence of schistosomiasis (OR = 0.44, 95%CI = 0.22–0.72, Pcorr = 0.0004). The reconstructed COLEC11*TCCA haplotypes were associated with higher CL-K1 serum levels (P = 0.002) and with decreased schistosomiasis (OR = 0.38, 95%CI = 0.23–0.63, Pcorr = 0.0001). Conclusions In agreement with findings from our earlier published study, our findings support the observation that CL-K1 and their functional variants may be host factors associated with protection in schistosomiasis and may be a useful marker for further investigations. PMID:25807310

  16. Coloidal gold, ferritin and peroxidase as markers for electron microscopic double labeling lectin techniques.

    PubMed

    Roth, J; Binder, M

    1978-03-01

    Three markers, colloidal gold, ferritin and peroxidase, were checked for usefulness in double labeling of lectin-binding sites. The amount of various lectins for the stabilization of good sols of a different particle size was evaluated. Several lectin-gold complexes were prepared for electron microscopic labeling purposes, and the optimal amount of various lectins needed for stabilization of gold solutions of a different particle size was determined. The following combinations were investigated for their usefulness in labeling two different lectin-binding sites: lectin-gold and lectin-gold (different particle size), lectin-gold and lectin-ferritin, as well as lectin-ferritin and lectin-peroxidase. Of these combinations the latter did not give satisfactory results for double labeling. In all single and double labeling techniques with the above mentioned markers the quantitative evaluation of the number of lectin-binding sites is not feasible, but these techniques will be of considerable value for the investigation of the dynamics of different lectin-binding sites on the cell surface. PMID:632554

  17. Evaluation of the Contribution of Multiple DAMPs and DAMP Receptors in Cell Death-Induced Sterile Inflammatory Responses

    PubMed Central

    Patel, Zubin; Rock, Kenneth L.

    2014-01-01

    When cells die by necrosis in vivo they stimulate an inflammatory response. It is thought that this response is triggered when the injured cells expose proinflammatory molecules, collectively referred to as damage associated molecular patterns (DAMPs), which are recognized by cells or soluble molecules of the innate or adaptive immune system. Several putative DAMPs and/or their receptors have been identified, but whether and how much they participate in responses in vivo is incompletely understood, and they have not previously been compared side-by-side in the same models. This study focuses on evaluating the contribution of multiple mechanisms that have been proposed to or potentially could participate in cell death-induced inflammation: The third component of complement (C3), ATP (and its receptor P2X7), antibodies, the C-type lectin receptor Mincle (Clec4e), and protease-activated receptor 2 (PAR2). We investigate the role of these factors in cell death-induced inflammation to dead cells in the peritoneum and acetaminophen-induced liver damage. We find that mice deficient in antibody, C3 or PAR2 have impaired inflammatory responses to dying cells. In contrast there was no reduction in inflammation to cell death in the peritoneum or liver of mice that genetically lack Mincle, the P2X7 receptor or that were treated with apyrase to deplete ATP. These results indicate that antibody, complement and PAR2 contribute to cell death-induced inflammation but that Mincle and ATP- P2X7 receptor are not required for this response in at least 2 different in vivo models. PMID:25127469

  18. Evidence for a Lectin Specific for Sulfated Glycans in the Salivary Gland of the Malaria Vector, Anopheles gambiae

    PubMed Central

    Francischetti, Ivo M. B.; Ma, Dongying; Andersen, John F.; Ribeiro, José M. C.

    2014-01-01

    Salivary gland homogenate (SGH) from the female mosquitoes Anopheles gambiae, An. stephensi, An. freeborni, An. dirus and An. albimanus were found to exhibit hemagglutinating (lectin) activity. Lectin activity was not found for male An. gambiae, or female Ae aegypti, Culex quinquefasciatus, Phlebotomus duboscqi, and Lutzomyia longipalpis. With respect to species-specificity, An. gambiae SGH agglutinates red blood cells (RBC) from humans, horse, sheep, goat, pig, and cow; it is less active for rats RBC, and not detectable for guinea-pigs or chicken RBC. Notably, lectin activity was inhibited by low concentrations of dextran sulfate 50–500 K, fucoidan, heparin, laminin, heparin sulfate proteoglycan, sialyl-containing glycans (e.g. 3′-sialyl Lewis X, and 6′-sialyl lactose), and gangliosides (e.g. GM3, GD1, GD1b, GTB1, GM1, GQ1B), but not by simple sugars. These results imply that molecule(s) in the salivary gland target sulfated glycans. SGH from An. gambiae was also found to promote agglutination of HL-60 cells which are rich in sialyl Lewis X, a glycan that decorates PSGL-1, the neutrophils receptor that interacts with endothelial cell P-selectin. Accordingly, SGH interferes with HL-60 cells adhesion to immobilized P-selectin. Because An. gambiae SGH expresses galectins, one member of this family (herein named Agalectin) was expressed in E. coli. Recombinant Agalectin behaves as a non-covalent homodimer. It does not display lectin activity, and does not interact with 500 candidates tested in a Glycan microarray. Gel-filtration chromatography of the SGH of An. gambiae identified a fraction with hemagglutinating activity, which was analyzed by 1D PAGE followed by in-gel tryptic digestion, and nano-LC MS/MS. This approach identified several genes which emerge as candidates for a lectin targeting sulfated glycans, the first with this selectivity to be reported in the SGH of a blood-sucking arthropod. The role of salivary molecules (sialogenins) with lectin

  19. Use of labeled tomato lectin for imaging vasculature structures.

    PubMed

    Robertson, Richard T; Levine, Samantha T; Haynes, Sherry M; Gutierrez, Paula; Baratta, Janie L; Tan, Zhiqun; Longmuir, Kenneth J

    2015-02-01

    Intravascular injections of fluorescent or biotinylated tomato lectin were tested to study labeling of vascular elements in laboratory mice. Injections of Lycopersicon esculentum agglutinin (tomato lectin) (50-100 µg/100 µl) were made intravascularly, through the tail vein, through a cannula implanted in the jugular vein, or directly into the left ventricle of the heart. Tissues cut for thin 10- to 12-µm cryostat sections, or thick 50- to 100-µm vibratome sections, were examined using fluorescence microscopy. Tissue labeled by biotinylated lectin was examined by bright field microscopy or electron microscopy after tissue processing for biotin. Intravascular injections of tomato lectin led to labeling of vascular structures in a variety of tissues, including brain, kidney, liver, intestine, spleen, skin, skeletal and cardiac muscle, and experimental tumors. Analyses of fluorescence in serum indicated the lectin was cleared from circulating blood within 2 min. Capillary labeling was apparent in tissues collected from animals within 1 min of intravascular injections, remained robust for about 1 h, and then declined markedly until difficult to detect 12 h after injection. Light microscopic images suggest the lectin bound to the endothelial cells that form capillaries and endothelial cells that line some larger vessels. Electron microscopic studies confirmed the labeling of luminal surfaces of endothelial cells. Vascular labeling by tomato lectin is compatible with a variety of other morphological labeling techniques, including histochemistry and immunocytochemistry, and thus appears to be a sensitive and useful method to reveal vascular patterns in relationship to other aspects of parenchymal development, structure, and function. PMID:25534591

  20. Specificity analysis of lectins and antibodies using remodeled glycoproteins.

    PubMed

    Iskratsch, Thomas; Braun, Andreas; Paschinger, Katharina; Wilson, Iain B H

    2009-03-15

    Due to their ability to bind specifically to certain carbohydrate sequences, lectins are a frequently used tool in cytology, histology, and glycan analysis but also offer new options for drug targeting and drug delivery systems. For these and other potential applications, it is necessary to be certain as to the carbohydrate structures interacting with the lectin. Therefore, we used glycoproteins remodeled with glycosyltransferases and glycosidases for testing specificities of lectins from Aleuria aurantia (AAL), Erythrina cristagalli (ECL), Griffonia simplicifolia (GSL I-B(4)), Helix pomatia agglutinin (HPA), Lens culinaris (LCA), Lotus tetragonolobus (LTA), peanut (Arachis hypogaeae) (PNA), Ricinus communis (RCA I), Sambucus nigra (SNA), Vicia villosa (VVA), and wheat germ (Triticum vulgaris) (WGA) as well as reactivities of anti-carbohydrate antibodies (anti-bee venom, anti-horseradish peroxidase [anti-HRP], and anti-Lewis(x)). After enzymatic remodeling, the resulting neoglycoforms display defined carbohydrate sequences and can be used, when spotted on nitrocellulose or in enzyme-linked lectinosorbent assays, to identify the sugar moieties bound by the lectins. Transferrin with its two biantennary complex N-glycans was used as scaffold for gaining diverse N-glycosidic structures, whereas fetuin was modified using glycosidases to test the specificities of lectins toward both N- and O-glycans. In addition, alpha(1)-acid glycoprotein and Schistosoma mansoni egg extract were chosen as controls for lectin interactions with fucosylated glycans (Lewis(x) and core alpha1,3-fucose). Our data complement and expand the existing knowledge about the binding specificity of a range of commercially available lectins. PMID:19123999

  1. C-Type Natriuretic Peptide Induces Anti-contractile Effect Dependent on Nitric Oxide, Oxidative Stress, and NPR-B Activation in Sepsis

    PubMed Central

    Pernomian, Laena; Prado, Alejandro F.; Silva, Bruno R.; Azevedo, Aline; Pinheiro, Lucas C.; Tanus-Santos, José E.; Bendhack, Lusiane M.

    2016-01-01

    Aims: To evaluate the role of nitric oxide, reactive oxygen species (ROS), and natriuretic peptide receptor-B activation in C-type natriuretic peptide-anti-contractile effect on Phenylephrine-induced contraction in aorta isolated from septic rats. Methods and Results: Cecal ligation and puncture (CLP) surgery was used to induce sepsis in male rats. Vascular reactivity was conducted in rat aorta and resistance mesenteric artery (RMA). Measurement of survival rate, mean arterial pressure (MAP), plasma nitric oxide, specific protein expression, and localization were evaluated. Septic rats had a survival rate about 37% at 4 h after the surgery, and these rats presented hypotension compared to control-operated (Sham) rats. Phenylephrine-induced contraction was decreased in sepsis. C-type natriuretic peptide (CNP) induced anti-contractile effect in aortas. Plasma nitric oxide was increased in sepsis. Nitric oxide-synthase but not natriuretic peptide receptor-B expression was increased in septic rat aortas. C-type natriuretic peptide-anti-contractile effect was dependent on nitric oxide-synthase, ROS, and natriuretic peptide receptor-B activation. Natriuretic peptide receptor-C, protein kinase-Cα mRNA, and basal nicotinamide adenine dinucleotide phosphate (NADPH)-dependent ROS production were lower in septic rats. Phenylephrine and CNP enhanced ROS production. However, stimulated ROS production was low in sepsis. Conclusion: CNP induced anti-contractile effect on Phenylephrine contraction in aortas from Sham and septic rats that was dependent on nitric oxide-synthase, ROS, and natriuretic peptide receptor-B activation. PMID:27445832

  2. The mammalian lectin galectin-8 induces RANKL expression, osteoclastogenesis, and bone mass reduction in mice

    PubMed Central

    Vinik, Yaron; Shatz-Azoulay, Hadas; Vivanti, Alessia; Hever, Navit; Levy, Yifat; Karmona, Rotem; Brumfeld, Vlad; Baraghithy, Saja; Attar-Lamdar, Malka; Boura-Halfon, Sigalit; Bab, Itai; Zick, Yehiel

    2015-01-01

    Skeletal integrity is maintained by the co-ordinated activity of osteoblasts, the bone-forming cells, and osteoclasts, the bone-resorbing cells. In this study, we show that mice overexpressing galectin-8, a secreted mammalian lectin of the galectins family, exhibit accelerated osteoclasts activity and bone turnover, which culminates in reduced bone mass, similar to cases of postmenopausal osteoporosis and cancerous osteolysis. This phenotype can be attributed to a direct action of galectin-8 on primary cultures of osteoblasts that secrete the osteoclastogenic factor RANKL upon binding of galectin-8. This results in enhanced differentiation into osteoclasts of the bone marrow cells co-cultured with galectin-8-treated osteoblasts. Secretion of RANKL by galectin-8-treated osteoblasts can be attributed to binding of galectin-8 to receptor complexes that positively (uPAR and MRC2) and negatively (LRP1) regulate galectin-8 function. Our findings identify galectins as new players in osteoclastogenesis and bone remodeling, and highlight a potential regulation of bone mass by animal lectins. DOI: http://dx.doi.org/10.7554/eLife.05914.001 PMID:25955862

  3. The mammalian lectin galectin-8 induces RANKL expression, osteoclastogenesis, and bone mass reduction in mice.

    PubMed

    Vinik, Yaron; Shatz-Azoulay, Hadas; Vivanti, Alessia; Hever, Navit; Levy, Yifat; Karmona, Rotem; Brumfeld, Vlad; Baraghithy, Saja; Attar-Lamdar, Malka; Boura-Halfon, Sigalit; Bab, Itai; Zick, Yehiel

    2015-01-01

    Skeletal integrity is maintained by the co-ordinated activity of osteoblasts, the bone-forming cells, and osteoclasts, the bone-resorbing cells. In this study, we show that mice overexpressing galectin-8, a secreted mammalian lectin of the galectins family, exhibit accelerated osteoclasts activity and bone turnover, which culminates in reduced bone mass, similar to cases of postmenopausal osteoporosis and cancerous osteolysis. This phenotype can be attributed to a direct action of galectin-8 on primary cultures of osteoblasts that secrete the osteoclastogenic factor RANKL upon binding of galectin-8. This results in enhanced differentiation into osteoclasts of the bone marrow cells co-cultured with galectin-8-treated osteoblasts. Secretion of RANKL by galectin-8-treated osteoblasts can be attributed to binding of galectin-8 to receptor complexes that positively (uPAR and MRC2) and negatively (LRP1) regulate galectin-8 function. Our findings identify galectins as new players in osteoclastogenesis and bone remodeling, and highlight a potential regulation of bone mass by animal lectins. PMID:25955862

  4. MytiLec, a Mussel R-Type Lectin, Interacts with Surface Glycan Gb3 on Burkitt’s Lymphoma Cells to Trigger Apoptosis through Multiple Pathways

    PubMed Central

    Hasan, Imtiaj; Sugawara, Shigeki; Fujii, Yuki; Koide, Yasuhiro; Terada, Daiki; Iimura, Naoya; Fujiwara, Toshiyuki; Takahashi, Keisuke G.; Kojima, Nobuhiko; Rajia, Sultana; Kawsar, Sarkar M. A.; Kanaly, Robert A.; Uchiyama, Hideho; Hosono, Masahiro; Ogawa, Yukiko; Fujita, Hideaki; Hamako, Jiharu; Matsui, Taei; Ozeki, Yasuhiro

    2015-01-01

    MytiLec; a novel lectin isolated from the Mediterranean mussel (Mytilus galloprovincialis); shows strong binding affinity to globotriose (Gb3: Galα1-4Galβ1-4Glc). MytiLec revealed β-trefoil folding as also found in the ricin B-subunit type (R-type) lectin family, although the amino acid sequences were quite different. Classification of R-type lectin family members therefore needs to be based on conformation as well as on primary structure. MytiLec specifically killed Burkitt's lymphoma Ramos cells, which express Gb3. Fluorescein-labeling assay revealed that MytiLec was incorporated inside the cells. MytiLec treatment of Ramos cells resulted in activation of both classical MAPK/ extracellular signal-regulated kinase and extracellular signal-regulated kinase (MEK-ERK) and stress-activated (p38 kinase and JNK) Mitogen-activated protein kinases (MAPK) pathways. In the cells, MytiLec treatment triggered expression of tumor necrosis factor (TNF)-α (a ligand of death receptor-dependent apoptosis) and activation of mitochondria-controlling caspase-9 (initiator caspase) and caspase-3 (activator caspase). Experiments using the specific MEK inhibitor U0126 showed that MytiLec-induced phosphorylation of the MEK-ERK pathway up-regulated expression of the cyclin-dependent kinase inhibitor p21, leading to cell cycle arrest and TNF-α production. Activation of caspase-3 by MytiLec appeared to be regulated by multiple different pathways. Our findings, taken together, indicate that the novel R-type lectin MytiLec initiates programmed cell death of Burkitt’s lymphoma cells through multiple pathways (MAPK cascade, death receptor signaling; caspase activation) based on interaction of the lectin with Gb3-containing glycosphingolipid-enriched microdomains on the cell surface. PMID:26694420

  5. MytiLec, a Mussel R-Type Lectin, Interacts with Surface Glycan Gb3 on Burkitt's Lymphoma Cells to Trigger Apoptosis through Multiple Pathways.

    PubMed

    Hasan, Imtiaj; Sugawara, Shigeki; Fujii, Yuki; Koide, Yasuhiro; Terada, Daiki; Iimura, Naoya; Fujiwara, Toshiyuki; Takahashi, Keisuke G; Kojima, Nobuhiko; Rajia, Sultana; Kawsar, Sarkar M A; Kanaly, Robert A; Uchiyama, Hideho; Hosono, Masahiro; Ogawa, Yukiko; Fujita, Hideaki; Hamako, Jiharu; Matsui, Taei; Ozeki, Yasuhiro

    2015-12-01

    MytiLec; a novel lectin isolated from the Mediterranean mussel (Mytilus galloprovincialis); shows strong binding affinity to globotriose (Gb3: Galα1-4Galβ1-4Glc). MytiLec revealed β-trefoil folding as also found in the ricin B-subunit type (R-type) lectin family, although the amino acid sequences were quite different. Classification of R-type lectin family members therefore needs to be based on conformation as well as on primary structure. MytiLec specifically killed Burkitt's lymphoma Ramos cells, which express Gb3. Fluorescein-labeling assay revealed that MytiLec was incorporated inside the cells. MytiLec treatment of Ramos cells resulted in activation of both classical MAPK/ extracellular signal-regulated kinase and extracellular signal-regulated kinase (MEK-ERK) and stress-activated (p38 kinase and JNK) Mitogen-activated protein kinases (MAPK) pathways. In the cells, MytiLec treatment triggered expression of tumor necrosis factor (TNF)-α (a ligand of death receptor-dependent apoptosis) and activation of mitochondria-controlling caspase-9 (initiator caspase) and caspase-3 (activator caspase). Experiments using the specific MEK inhibitor U0126 showed that MytiLec-induced phosphorylation of the MEK-ERK pathway up-regulated expression of the cyclin-dependent kinase inhibitor p21, leading to cell cycle arrest and TNF-α production. Activation of caspase-3 by MytiLec appeared to be regulated by multiple different pathways. Our findings, taken together, indicate that the novel R-type lectin MytiLec initiates programmed cell death of Burkitt's lymphoma cells through multiple pathways (MAPK cascade, death receptor signaling; caspase activation) based on interaction of the lectin with Gb3-containing glycosphingolipid-enriched microdomains on the cell surface. PMID:26694420

  6. 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

  7. Bjcul, a snake venom lectin, modulates monocyte-derived macrophages to a pro-inflammatory profile in vitro.

    PubMed

    Dias-Netipanyj, M F; Boldrini-Leite, L M; Trindade, E S; Moreno-Amaral, A N; Elifio-Esposito, S

    2016-06-01

    Macrophages are cells of high plasticity and can act in different ways to ensure that the appropriate immune response remains controlled. This study shows the effects of the C-type Bothrops jararacussu venom lectin (BJcuL) on the activation of human macrophages derived from the U937 cell line. BJcuL binds on the cell surface, and this event is inhibited by its specific carbohydrate. It induced phagocytosis and production of H2O2, and expression of antigen presentation molecules. It also enhanced the production of TNF-α, GM-CSF and IL-6 by macrophages and indirectly induced T cells to an increased production of TNF-α, IFN-γ and IL-6 in the presence of LPS. Our results suggest that BJcuL can modulate macrophage functional activation towards an M1 state. PMID:26944802

  8. HGA-2, a novel galactoside-binding lectin from the sea cucumber Holothuria grisea binds to bacterial cells.

    PubMed

    de Melo, Arthur Alves; Carneiro, Rômulo Farias; de Melo Silva, Winnie; Moura, Raniere da Mata; Silva, Giselle Cristina; de Sousa, Oscarina Viana; de Sousa Saboya, Jefferson Pablo; Nascimento, Kyria Santiago do; Saker-Sampaio, Silvana; Nagano, Celso Shiniti; Cavada, Benildo Sousa; Sampaio, Alexandre Holanda

    2014-03-01

    A novel lectin, HGA-2, was isolated from the sea cucumber Holothuria grisea. The protein was isolated by a single chromatographic step using a column of Guar Gum as affinity. HGA-2 showed an apparent molecular mass of 17 kDa and 34 kDa under reducing and nonreducing conditions, respectively. The hemagglutinating activity was specific for rabbit erythrocytes, showing no activity for human blood A, B and O. Its hemagglutinating activity was inhibited by carbohydrates containing galactose, with higher affinity for GalNAc and glycoprotein porcine stomach mucin (PSM). HGA-2 was stable at pH 6-10, significantly declining at pH 5 and a temperature of 40°C, with its activity being abolished at 100 °C. The HGA-2 protein was found to be Ca(2+)-dependent; it was highly toxic against Artemia nauplii and able to recognize and agglutinate cells of Escherichia coli. Amino acid sequences of tryptic peptides of HGA-2 strongly suggest that HGA-2 is a member of the C-type lectin family. PMID:24393613

  9. 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

  10. Purification and some properties of a lectin from the fruit juice of the tomato (Lycopersicon esculentum).

    PubMed Central

    Kilpatrick, D C

    1980-01-01

    In the tomato (Lycopersicon esculentum) plant, the fruit juice was found to be the richest source of agglutinating activity. The lectin responsible could be inhibited by oligomers of N-acetylglucosamine, and this property was exploited to purify the lectin by affinity adsorption on trypsin-treated erythrocytes. The lectin is a glycoprotein that cross-reacts immunologically with the lectin from Datura stramonium (thorn-apple). PMID:7378052

  11. Prevalence of the F-type lectin domain.

    PubMed

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

    2015-08-01

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

  12. 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

  13. Lectin histochemistry of palatine glands in the developing rat.

    PubMed

    Hakami, Zaki; Kitaura, Hideki; Honma, Shiho; Wakisaka, Satoshi; Takano-Yamamoto, Teruko

    2014-05-01

    This study examined the binding pattern of lectins, soybean agglutinin (SBA), Dolichos biflorus agglutinin (DBA), Vicia villosa agglutinin (VVA), Ulex europaeus agglutinin-I (UEA-I), peanut agglutinin (PNA), wheat germ agglutinin (WGA), and succinylated WGA (sucWGA) in the developing rat palatine glands. In adult rats, heterogeneous lectin binding patterns were revealed between the anterior and posterior portions of palatine glands, as DBA, VVA, and WGA were bound more intensely and broadly in the posterior portion. SBA, PNA, and sucWGA showed far less reactivity in the anterior than in the posterior portion. At embryonic day 18 (E18), weak labeling was observed with UEA-I and WGA at the basal membrane of terminal buds, UEA-I and PNA labeled the epithelial cord, and there was no apparent binding for SBA, DBA, VVA, and sucWGA. At E20, after acinar lumenization, all lectins were detected at the acinar cell basal membranes. After birth, all lectins detectably labeled at the mucous cell apical membranes and progressively, with maturation, extended from the apical to basal portions of the cytoplasm. Apparent serous cells were observed around postnatal day 10 (PN10) and bound UEA-I. Lectins reached peak reactivity at PN21 and the binding patterns became identical to those of adults around PN28. PMID:24345684

  14. Impacts of Shewanella oneidensis c-type cytochromes on aerobic and anaerobic respiration

    SciTech Connect

    Gao, Haichun; Barua, Soumitra; Liang, Yili; Wu, Lianming; Dong, Yangyang; Reed, Samantha B.; Chen, Jingrong; Culley, David E.; Kennedy, David W.; Yang, Yunfeng; He, Zhili; Nealson, Kenneth H.; Fredrickson, Jim K.; Tiedje, James M.; Romine, Margaret F.; Zhou, Jizhong

    2010-06-24

    Shewanella are renowned for their ability to utilize a wide range of electron acceptors (EA) for respiration, which has been partially accredited to the presence of a large number of the c-type cytochromes. To investigate the involvement of c-type cytochrome proteins in aerobic and anaerobic respiration of Shewanella oneidensis Mr -1, 36 in-frame deletion mutants, among possible 41 predicted, c-type cytochrome genes were obtained. The potential involvement of each individual c-type cytochrome in the reduction of a variety of EAs was assessed individually as well as in competition experiments. While results on the wellstudied c-type cytochromes CymA(SO4591) and MtrC(SO1778) were consistent with previous findings, collective observations were very interesting: the responses of S. oneidensis Mr -1 to low and highly toxic metals appeared to be significantly different; CcoO, CcoP and PetC, proteins involved in aerobic respiration in various organisms, played critical roles in both aerobic and anaerobic respiration with highly toxic metals as EA. In addition, these studies also suggested that an uncharacterized c-type cytochrome (SO4047) may be important to both aerobiosis and anaerobiosis.

  15. Characterization of purified c-type heme-containing peptides and identification of c-type heme-attachment sites in Shewanella oneidenis cytochromes using mass spectrometry

    SciTech Connect

    Yang, Feng; Bogdanov, Bogdan; Strittmatter, Eric F.; Vilkov, Andrey N.; Gritsenko, Marina A.; Shi, Liang; Elias, Dwayne A.; Ni, Shuisong; Romine, Margaret F.; Pasa-Tolic, Liljiana; Lipton, Mary S.; Smith, Richard D.

    2005-05-01

    We describe methods for mass spectrometric identification of heme-containing peptides from digests of c-type cytochromes that contain the CXXCH(X = any amino acid) sequence motif. Analysis of purified standard heme-containing peptides showed that the charged heme group was present both before and after peptide fragmentation in the gas phase. The heme fragment ion yielded the most abundant MS/MS peak for standard heme-containing peptides with one amino acid difference (DAA=1) for both 2+ and 3+ peptide charge states and the extent of heme loss during peptide fragmentation was affected by both sequence and charge. A modified search strategy was evaluated with tryptic digests of one known and two unknown cytochromes from Shewanella oneidenis, demonstrating that this approach can be generally applied for identification of c-type heme-containing peptides from complex samples.

  16. A Novel C-Type Lysozyme from Mytilus galloprovincialis: Insight into Innate Immunity and Molecular Evolution of Invertebrate C-Type Lysozymes

    PubMed Central

    Wang, Qing; Wang, Chunyan; Mu, Changkao; Wu, Huifeng; Zhang, Linbao; Zhao, Jianmin

    2013-01-01

    A c-type lysozyme (named as MgCLYZ) gene was cloned from the mussel Mytilus galloprovincialis. Blast analysis indicated that MgCLYZ was a salivary c-type lysozyme which was mainly found in insects. The nucleotide sequence of MgCLYZ was predicted to encode a polypeptide of 154 amino acid residues with the signal peptide comprising the first 24 residues. The deduced mature peptide of MgCLYZ was of a calculated molecular weight of 14.4 kD and a theoretical isoelectric point (pI) of 8.08. Evolution analysis suggested that bivalve branch of the invertebrate c-type lysozymes phylogeny tree underwent positive selection during evolution. By quantitative real-time RT-PCR (qRT-PCR) analysis, MgCLYZ transcript was widely detected in all examined tissues and responded sensitively to bacterial challenge in hemocytes and hepatopancreas. The optimal temperature and pH of recombinant MgCLYZ (rMgCLYZ) were 20°C and 4, respectively. The rMgCLYZ displayed lytic activities against Gram-positive bacteria including Micrococcus luteus and Staphyloccocus aureus, and Gram-negative bacteria including Vibrio anguillarum, Enterobacter cloacae, Pseudomonas putida, Proteus mirabilis and Bacillus aquimaris. These results suggest that MgCLYZ perhaps play an important role in innate immunity of M. galloprovincialis, and invertebrate c-type lysozymes might be under positive selection in a species-specific manner during evolution for undergoing adaptation to different environment and diverse pathogens. PMID:23818979

  17. A lectin with antifungal activity from the mussel Crenomytilus grayanus.

    PubMed

    Chikalovets, Irina V; Chernikov, Oleg V; Pivkin, Mikhail V; Molchanova, Valentina I; Litovchenko, Alina P; Li, Wei; Lukyanov, Pavel A

    2015-02-01

    Lectins (carbohydrate-binding proteins) are well known to actively participate in the defense functions of vertebrates and invertebrates where they play an important role in the recognition of foreign particles. In this study, we investigated of in vitro antifungal activity of lectin from the mussel Crenomytilus grayanus (CGL). Enzyme-linked immunosorbent assay indicated that CGL was predominantly detectable in tissues of mantle and to a lesser degree in the tissues of muscle, hepatopancreas, gill and hemocytes. After challenged by Pichia pastoris the level of CGL was upregulated and reached the maximum level at 12 h post challenge and recovered to the original level at 24 h. The lectin was capable of inhibiting the germination of spores and hyphal growth in the fungi. All these results indicated that CGL is involved in the innate immune response in mollusc animals. PMID:25482060

  18. 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. PMID:12777210

  19. Isolation and biochemical characterization of Apios tuber lectin.

    PubMed

    Kenmochi, Eri; Kabir, Syed Rashel; Ogawa, Tomohisa; Naude, Ryno; Tateno, Hiroaki; Hirabayashi, Jun; Muramoto, Koji

    2015-01-01

    Apios tuber lectin, named ATL, was isolated from Apios americana Medikus by two chromatography steps, hydrophobic chromatography and anion-exchange chromatography. The minimum concentration required for the hemagglutination activity toward rabbit erythrocytes of ATL was 4 μg/mL. ATL was composed of a homodimer of 28.4 kDa subunits. The amino acid sequence of ATL was similar to those of other legume lectins. The lectin showed moderate stability toward heating and acidic pH, and the binding affinity against several monosaccharides, such as D-glucosamine and D-galactosamine. ATL also bound to desialylated or agalactosylated glycoproteins such as asialo and agalacto transferrin. ATL decreased the transepithelial electrical resistance across human intestinal Caco-2 cell monolayers, suggesting the effect on the tight junction-mediated paracellular transport. PMID:25584830

  20. Differential Toll-Like Receptor Recognition and Induction of Cytokine Profile by Bifidobacterium breve and Lactobacillus Strains of Probiotics ▿

    PubMed Central

    Plantinga, Theo S.; van Maren, Wendy W. C.; van Bergenhenegouwen, Jeroen; Hameetman, Marjolijn; Nierkens, Stefan; Jacobs, Cor; de Jong, Dirk J.; Joosten, Leo A. B.; van't Land, Belinda; Garssen, Johan; Adema, Gosse J.; Netea, Mihai G.

    2011-01-01

    The use of probiotics as a food supplement has gained tremendous interest in the last few years as beneficial effects were reported in gut homeostasis and nutrient absorption but also in immunocompromised patients, supporting protection from colonization or infection with pathogenic bacteria or fungi. As a treatment approach for inflammatory bowel diseases, a suitable probiotic strain would ideally be one with a low immunogenic potential. Insight into the immunogenicities and types of T-cell responses induced by potentially probiotic strains allows a more rational selection of a particular strain. In the present study, the bacterial strains Bifidobacterium breve (NumRes 204), Lactobacillus rhamnosus (NumRes1), and Lactobacillus casei (DN-114 001) were compared concerning their capacity to induce inflammatory responses in terms of cytokine production by human and mouse primary immune cells. It was demonstrated that the B. breve strain induced lower levels of the proinflammatory cytokine gamma interferon (IFN-γ) than the tested L. rhamnosus and L. casei strains. Both B. breve and lactobacilli induced cytokines in a Toll-like receptor 9 (TLR9)-dependent manner, while the lower inflammatory profile of B. breve was due to inhibitory effects of TLR2. No role for TLR4, NOD2, and C-type lectin receptors was apparent. In conclusion, TLR signaling is involved in the differentiation of inflammatory responses between probiotic strains used as food supplements. PMID:21288993

  1. Molecular Cloning and Functional Characterization of Mannose Receptor in Zebra Fish (Danio rerio) during Infection with Aeromonas sobria.

    PubMed

    Zheng, Feifei; Asim, Muhammad; Lan, Jiangfeng; Zhao, Lijuan; Wei, Shun; Chen, Nan; Liu, Xiaoling; Zhou, Yang; Lin, Li

    2015-01-01

    Mannose receptor (MR) is a member of pattern-recognition receptors (PRRs), which plays a significant role in immunity responses. Much work on MR has been done in mammals and birds while little in fish. In this report, a MR gene (designated as zfMR) was cloned from zebra fish (Danio rerio), which is an attractive model for the studies of animal diseases. The full-length cDNA of zfMR contains 6248 bp encoding a putative protein of 1428 amino acids. The predicted amino acid sequences showed that zfMR contained a cysteine-rich domain, a single fibronectin type II (FN II) domain, eight C-type lectin-like domains (CTLDs), a transmembrane domain and a short C-terminal cytoplasmic domain, sharing highly conserved structures with MRs from the other species. The MR mRNA could be detected in all examined tissues with highest level in kidney. The temporal expression patterns of MR, IL-1β and TNF-α mRNAs were analyzed in the liver, spleen, kidney and intestine post of infection with Aeromonas sobria. By immunohistochemistry assay, slight enhancement of MR protein was also observed in the spleen and intestine of the infected zebra fish. The established zebra fish-A. sobria infection model will be valuable for elucidating the role of MR in fish immune responses to infection. PMID:25988382

  2. In vitro immunostimulatory properties of Abrus lectins derived peptides in tumor bearing mice.

    PubMed

    Bhutia, Sujit K; Mallick, Sanjaya K; Maiti, Tapas K

    2009-08-01

    In vitro immunostimulatory effect of Abrus lectins derived peptide fractions (AGP and ABP) was investigated in DL bearing mice. Both AGP and ABP were found to activate splenocytes and induced production of cytokines like IL-2, IFN-gamma and TNF-alpha indicating a Th1 type of immune response. Analysis of in vitro treated splenocytes by flow cytometry revealed an increase in percentage of T and B cell with high expression of activation markers (CD25(+) and CD71(+)). At the same time, expression of co-stimulatory markers was significantly high compared to tumor control. The tumor associated macrophages were able to stimulate NO production, IL-1 secretion, increased phagocytosis and decreased expression of mannose receptor. It was also observed that NK cell was activated by AGP and ABP. These results suggest that both AGP and ABP act as immunostimulants in vitro in DL bearing mice. PMID:19303750

  3. Bi- to tetravalent glycoclusters presenting GlcNAc/GalNAc as inhibitors: from plant agglutinins to human macrophage galactose-type lectin (CD301) and galectins.

    PubMed

    André, Sabine; O'Sullivan, Shane; Koller, Christiane; Murphy, Paul V; Gabius, Hans-Joachim

    2015-04-14

    Emerging insights into the functional spectrum of tissue lectins leads to identification of new targets for the custom-made design of potent inhibitors, providing a challenge for synthetic chemistry. The affinity and selectivity of a carbohydrate ligand for a lectin may immensely be increased by a number of approaches, which includes varying geometrical or topological features. This perspective leads to the design and synthesis of glycoclusters and their testing using assays of physiological relevance. Herein, hydroquinone, resorcinol, benzene-1,3,5-triol and tetra(4-hydroxyphenyl)ethene have been employed as scaffolds and propargyl derivatives obtained. The triazole-containing linker to the α/β-O/S-glycosides of GlcNAc/GalNAc presented on these scaffolds was generated by copper-catalysed azide-alkyne cycloaddition. This strategy was used to give a panel of nine glycoclusters with bi-, tri- and tetravalency. Maintained activity for lectin binding after conjugation was ascertained for both sugars in solid-phase assays with the plant agglutinins WGA (GlcNAc) and DBA (GalNAc). Absence of cross-reactivity excluded any carbohydrate-independent reactivity of the bivalent compounds, allowing us to proceed to further testing with a biomedically relevant lectin specific for GalNAc. Macrophage galactose(-binding C)-type lectin, involved in immune defence by dendritic cells and in virus uptake, was produced as a soluble protein without/with its α-helical coiled-coil stalk region. Binding to ligands presented on a matrix and on cell surfaces was highly susceptible to the presence of the tetravalent inhibitor derived from the tetraphenylethene-containing scaffold, and presentation of GalNAc with an α-thioglycosidic linkage proved favorable. Cross-reactivity of this glycocluster to human galectins-3 and -4, which interact with Tn-antigen-presenting mucins, was rather small. Evidently, the valency and spatial display of α-GalNAc residues is a key factor to design potent and

  4. 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. PMID:26638121

  5. Ferromagnetic levan composite: an affinity matrix to purify lectin.

    PubMed

    Angeli, Renata; da Paz, Nathalia V N; Maciel, Jackeline C; Araújo, Flávia F B; Paiva, Patrícia M G; Calazans, Glícia M T; Valente, Ana Paula; Almeida, Fábio C L; Coelho, Luana C B B; Carvalho, Luiz B; Silva, Maria da Paz C; dos Santos Correia, Maria Tereza

    2009-01-01

    A simple and inexpensive procedure used magnetite and levan to synthesize a composite recovered by a magnetic field. Lectins from Canavalia ensiformis (Con A) and Cratylia mollis (Cramoll 1 and Cramoll 1, 4) did bind specifically to composite. The magnetic property of derivative favored washing out contaminating proteins and recovery of pure lectins with glucose elution. Cramoll 1 was purified by this affinity binding procedure in two steps instead of a previous three-step protocol with ammonium sulfate fractionation, affinity chromatography on Sephadex G-75, and ion exchange chromatography through a CM-cellulose column. PMID:19547713

  6. Ferromagnetic Levan Composite: An Affinity Matrix to Purify Lectin

    PubMed Central

    Angeli, Renata; da Paz, Nathalia V. N.; Maciel, Jackeline C.; Araújo, Flávia F. B.; Paiva, Patrícia M. G.; Calazans, Glícia M. T.; Valente, Ana Paula; Almeida, Fábio C. L.; Coelho, Luana C. B. B.; Carvalho, Luiz B.; Silva, Maria da Paz C.; dos Santos Correia, Maria Tereza

    2009-01-01

    A simple and inexpensive procedure used magnetite and levan to synthesize a composite recovered by a magnetic field. Lectins from Canavalia ensiformis (Con A) and Cratylia mollis (Cramoll 1 and Cramoll 1, 4) did bind specifically to composite. The magnetic property of derivative favored washing out contaminating proteins and recovery of pure lectins with glucose elution. Cramoll 1 was purified by this affinity binding procedure in two steps instead of a previous three-step protocol with ammonium sulfate fractionation, affinity chromatography on Sephadex G-75, and ion exchange chromatography through a CM-cellulose column. PMID:19547713

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

    PubMed Central

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

    2012-01-01

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

  8. Lectin binding and surface glycoprotein pattern of human macrophage populations.

    PubMed

    Kreipe, H; Radzun, H J; Schumacher, U; Parwaresch, M R

    1986-01-01

    In the present study unstimulated and stimulated human blood monocytes, untreated and phorbol ester treated U-937 cells, as well as human peritoneal and alveolar macrophages were studied with respect to their surface membrane properties. Binding of different lectins and electrophoretic patterns of tritium labeled surface glycoproteins were compared. The analysis of surface glycoproteins could be interpreted as evidence for a common origin of the analysed cell populations. Furthermore, banding patterns of glycoproteins might be useful to define certain activation states within monocyte/macrophage differentiation. In contrast, lectin binding pattern did not clearly discriminate macrophage subpopulations. PMID:3102412

  9. Agrarian diet and diseases of affluence – Do evolutionary novel dietary lectins cause leptin resistance?

    PubMed Central

    Jönsson, Tommy; Olsson, Stefan; Ahrén, Bo; Bøg-Hansen, Thorkild C; Dole, Anita; Lindeberg, Staffan

    2005-01-01

    Background The global pattern of varying prevalence of diseases of affluence, such as obesity, cardiovascular disease and diabetes, suggests that some environmental factor specific to agrarian societies could initiate these diseases. Presentation of the hypothesis We propose that a cereal-based diet could be such an environmental factor. Through previous studies in archaeology and molecular evolution we conclude that humans and the human leptin system are not specifically adapted to a cereal-based diet, and that leptin resistance associated with diseases of affluence could be a sign of insufficient adaptation to such a diet. We further propose lectins as a cereal constituent with sufficient properties to cause leptin resistance, either through effects on metabolism central to the proper functions of the leptin system, and/or directly through binding to human leptin or human leptin receptor, thereby affecting the function. Testing the hypothesis Dietary interventions should compare effects of agrarian and non-agrarian diets on incidence of diseases of affluence, related risk factors and leptin resistance. A non-significant (p = 0.10) increase of cardiovascular mortality was noted in patients advised to eat more whole-grain cereals. Our lab conducted a study on 24 domestic pigs in which a cereal-free hunter-gatherer diet promoted significantly higher insulin sensitivity, lower diastolic blood pressure and lower C-reactive protein as compared to a cereal-based swine feed. Testing should also evaluate the effects of grass lectins on the leptin system in vivo by diet interventions, and in vitro in various leptin and leptin receptor models. Our group currently conducts such studies. Implications of the hypothesis If an agrarian diet initiates diseases of affluence it should be possible to identify the responsible constituents and modify or remove them so as to make an agrarian diet healthier. PMID:16336696

  10. Interplay between metal binding and cis/trans isomerization in legume lectins: structural and thermodynamic study of P. angolensis lectin.

    PubMed

    Garcia-Pino, Abel; Buts, Lieven; Wyns, Lode; Loris, Remy

    2006-08-01

    The interplay between metal binding, carbohydrate binding activity, stability and structure of the lectin from Pterocarpus angolensis was investigated. Removal of the metals leads to a more flexible form of the protein with significantly less conformational stability. Crystal structures of this metal-free form show significant structural rearrangements, although some structural features that allow the binding of sugars are retained. We propose that substitution of an asparagine residue at the start of the C-terminal beta-strand of the legume lectin monomer hinders the trans-isomerization of the cis-peptide bond upon demetallization and constitutes an intramolecular switch governing the isomer state of the non-proline bond and ultimately the lectin phenotype. PMID:16824540

  11. Reappraisal of the 'lectin hypothesis' in the aetiopathogenesis of coeliac disease.

    PubMed

    Colyer, J; Farthing, M J; Kumar, P J; Clark, M L; Ohannesian, A D; Waldron, N M

    1986-07-01

    The agglutinating properties of a crude gluten digest, purified gliadin fractions and established plant lectins were investigated using mammalian erythrocytes, rat enterocytes and normal and coeliac human enterocytes as the target systems. Gliadin preparations failed to cause agglutination of any of the cells tested, whereas established pure plant lectins were active cell agglutinins. These studies indicate that gliadin peptides do not interact with intestinal cells in a polyvalent, lectin-like manner and as such cannot be regarded as true lectins. Mucosal damage in coeliac disease is unlikely therefore to be related to lectin-like activity of gliadin. PMID:3709069

  12. Trophism between C-type axon terminals and thoracic motoneurones in the cat

    PubMed Central

    Pullen, A. H.; Sears, T. A.

    1983-01-01

    1. Quantitative ultrastructural examinations of axon terminals synapsing with normal α-motoneurones in segment T9 of cat spinal cord provided estimates of their numbers, sizes and synaptic structure. One synapse, the C type, derived from short-axon propriospinal segmental interneurones, was studied in detail. 2. The numbers, sizes and post-synaptic structure of normal C-type synapses at T9 were compared with similar estimates from material provided by cats subjected to partial central deafferentation by double spinal hemisection at T5 and T10 between 7 days and 2 years previously. 3. The proportion of C-type synapses present progessively increased from 1% in normal cats to 8·8% 200 days following hemisection, and had still attained a level of 3·1% by 2 years; these increases imply that the absolute number of C-type synapses underwent increase. 4. Mean sizes of C-type synapses increased from 4·0 μm (normal) to 5·8 μm (200 days) and retained their enlarged sizes up to 2 years (5·9 μm). Furthermore, while 84% of C-type synapses were under 6 μm in length in normal motoneurones, 48% were over 6 μm long 200 days post-operatively. 5. The unique post-synaptic structure of C-type synapses also proliferated following partial central deafferentation of the motoneurones. The elongated cistern, increased numbers and individual lengths of lamellae of the associated underlying rough endoplasmic reticulum indicated a trophic interaction between the presynaptic C terminal and its post-synaptic motoneurone. 6. Counts of ribosomes `bound' to lamellae of the subsynaptic rough endoplasmic reticulum, and of the lamellae-associated polyribosomes interposed between individual lamellae for normal and 200 day post-operative C-type synapses indicated an over-all post-operative increase in capacity for local subsynaptic protein synthesis topographically directed towards this type of axon terminal. 7. The observed greater increase in frequency of ribosomes `bound' to the rough

  13. Reciprocal voltage sensor-to-pore coupling leads to potassium channel C-type inactivation

    NASA Astrophysics Data System (ADS)

    Conti, Luca; Renhorn, Jakob; Gabrielsson, Anders; Turesson, Fredrik; Liin, Sara I.; Lindahl, Erik; Elinder, Fredrik

    2016-06-01

    Voltage-gated potassium channels open at depolarized membrane voltages. A prolonged depolarization causes a rearrangement of the selectivity filter which terminates the conduction of ions – a process called slow or C-type inactivation. How structural rearrangements in the voltage-sensor domain (VSD) cause alteration in the selectivity filter, and vice versa, are not fully understood. We show that pulling the pore domain of the Shaker potassium channel towards the VSD by a Cd2+ bridge accelerates C-type inactivation. Molecular dynamics simulations show that such pulling widens the selectivity filter and disrupts the K+ coordination, a hallmark for C-type inactivation. An engineered Cd2+ bridge within the VSD also affect C-type inactivation. Conversely, a pore domain mutation affects VSD gating-charge movement. Finally, C-type inactivation is caused by the concerted action of distant amino acid residues in the pore domain. All together, these data suggest a reciprocal communication between the pore domain and the VSD in the extracellular portion of the channel.

  14. Reciprocal voltage sensor-to-pore coupling leads to potassium channel C-type inactivation

    PubMed Central

    Conti, Luca; Renhorn, Jakob; Gabrielsson, Anders; Turesson, Fredrik; Liin, Sara I; Lindahl, Erik; Elinder, Fredrik

    2016-01-01

    Voltage-gated potassium channels open at depolarized membrane voltages. A prolonged depolarization causes a rearrangement of the selectivity filter which terminates the conduction of ions – a process called slow or C-type inactivation. How structural rearrangements in the voltage-sensor domain (VSD) cause alteration in the selectivity filter, and vice versa, are not fully understood. We show that pulling the pore domain of the Shaker potassium channel towards the VSD by a Cd2+ bridge accelerates C-type inactivation. Molecular dynamics simulations show that such pulling widens the selectivity filter and disrupts the K+ coordination, a hallmark for C-type inactivation. An engineered Cd2+ bridge within the VSD also affect C-type inactivation. Conversely, a pore domain mutation affects VSD gating-charge movement. Finally, C-type inactivation is caused by the concerted action of distant amino acid residues in the pore domain. All together, these data suggest a reciprocal communication between the pore domain and the VSD in the extracellular portion of the channel. PMID:27278891

  15. Reciprocal voltage sensor-to-pore coupling leads to potassium channel C-type inactivation.

    PubMed

    Conti, Luca; Renhorn, Jakob; Gabrielsson, Anders; Turesson, Fredrik; Liin, Sara I; Lindahl, Erik; Elinder, Fredrik

    2016-01-01

    Voltage-gated potassium channels open at depolarized membrane voltages. A prolonged depolarization causes a rearrangement of the selectivity filter which terminates the conduction of ions - a process called slow or C-type inactivation. How structural rearrangements in the voltage-sensor domain (VSD) cause alteration in the selectivity filter, and vice versa, are not fully understood. We show that pulling the pore domain of the Shaker potassium channel towards the VSD by a Cd(2+) bridge accelerates C-type inactivation. Molecular dynamics simulations show that such pulling widens the selectivity filter and disrupts the K(+) coordination, a hallmark for C-type inactivation. An engineered Cd(2+) bridge within the VSD also affect C-type inactivation. Conversely, a pore domain mutation affects VSD gating-charge movement. Finally, C-type inactivation is caused by the concerted action of distant amino acid residues in the pore domain. All together, these data suggest a reciprocal communication between the pore domain and the VSD in the extracellular portion of the channel. PMID:27278891

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

    PubMed

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

    2014-06-01

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

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

    PubMed Central

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

    2014-01-01

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

  18. The use of lectin microarray for assessing glycosylation of therapeutic proteins

    PubMed Central

    Zhang, Lei; Luo, Shen; Zhang, Baolin

    2016-01-01

    ABSTRACT Glycans or carbohydrates attached to therapeutic glycoproteins can directly affect product quality, safety and efficacy, and therefore must be adequately analyzed and controlled throughout product life cycles. However, the complexity of protein glycosylation poses a daunting analytical challenge. In this study, we evaluated the utility of a lectin microarray for assessing protein glycans. Using commercial lectin chips, which contain 45 lectins toward distinct glycan structures, we were able to determine the lectin binding patterns of a panel of 15 therapeutic proteins, including 8 monoclonal antibodies. Lectin binding signals were analyzed to generate glycan profiles that were generally consistent with the known glycan patterns for these glycoproteins. In particular, the lectin-based microarray was found to be highly sensitive to variations in the terminal carbohydrate structures such as galactose versus sialic acid epitopes. These data suggest that lectin microarray could be used for screening glycan patterns of therapeutic glycoproteins. PMID:26918373

  19. Differential in vitro inhibitory activity against HIV-1 of alpha-(1-3)- and alpha-(1-6)-D-mannose specific plant lectins : Implication for microbicide development

    PubMed Central

    Saïdi, Hela; Nasreddine, Nadine; Jenabian, Mohammad-Ali; Lecerf, Maxime; Schols, Dominique; Krief, Corinne; Balzarini, Jan; Bélec, Laurent

    2007-01-01

    Background Plant lectins such as Galanthus nivalis agglutinin (GNA) and Hippeastrum hybrid agglutinin (HHA) are natural proteins able to link mannose residues, and therefore inhibit HIV-target cell interactions. Plant lectins are candidate for microbicide development. Objective To evaluate the activity against HIV of the mannose-specific plant lectins HHA and GNA at the cellular membrane level of epithelial cells and monocyte-derived dendritic cells (MDDC), two potential target cells of HIV at the genital mucosal level. Methods The inhibitory effects of HHA and GNA were evaluated on HIV adsorption to genital epithelial HEC-1A cell line, on HIV transcytosis throughout a monolayer of polarized epithelial HEC-1A cells, on HIV adsorption to MDDC and on transfer of HIV from MDDC to autologous T lymphocytes. Results HHA faintly inhibited attachment to HEC-1A cells of the R5-tropic HIV-1Ba-L strain, in a dose-dependent manner, whereas GNA moderately inhibited HIV adsorption in the same context, but only at high drug doses. Only HHA, but not GNA, inhibited HIV-1JR-CSF transcytosis in a dose-dependent manner. By confocal microscopy, HHA, but not GNA, was adsorbed at the epithelial cell surface, suggesting that HHA interacts specifically with receptors mediating HIV-1 transcytosis. Both plant lectins partially inhibited HIV attachment to MDDC. HHA inhibited more efficiently the transfer of HIV from MDDC to T cell, than GNA. Both HHA and GNA lacked toxicity below 200 μg/ml irrespective the cellular system used and do not disturb the monolayer integrity of epithelial cells. Conclusion These observations demonstrate higher inhibitory activities of the lectin plant HHA by comparison to GNA, on HIV adsorption to HEC-1A cell line, HIV transcytosis through HEC-1A cell line monolayer, HIV adsorption to MDDC and HIV transfer from MDDC to T cells, highlighting the potential interest of HHA as effective microbicide against HIV. PMID:17565674

  20. c-Type Cytochromes and Manganese Oxidation in Pseudomonas putida MnB1

    PubMed Central

    Caspi, Ron; Tebo, Bradley M.; Haygood, M. G.

    1998-01-01

    Pseudomonas putida MnB1 is an isolate from an Mn oxide-encrusted pipeline that can oxidize Mn(II) to Mn oxides. We used transposon mutagenesis to construct mutants of strain MnB1 that are unable to oxidize manganese, and we characterized some of these mutants. The mutants were divided into three groups: mutants defective in the biogenesis of c-type cytochromes, mutants defective in genes that encode key enzymes of the tricarboxylic acid cycle, and mutants defective in the biosynthesis of tryptophan. The mutants in the first two groups were cytochrome c oxidase negative and did not contain c-type cytochromes. Mn(II) oxidation capability could be recovered in a c-type cytochrome biogenesis-defective mutant by complementation of the mutation. PMID:9758766

  1. Method of Asteroid S/C Type Classification Using Color Indices

    NASA Astrophysics Data System (ADS)

    Ye, Jia-hui; Zhao, Hai-bin; Li, Bin

    2016-01-01

    The color indices obtained from multi-color photometry have important significance of reference in the S/C type classification of asteroids, and the color parameter a derived from the principal component analysis of color indices is a key parameter of classification. Two methods, the direct demarcation at a = 0 and the cluster analysis of a-parameters, are applied to the asteroid S/C type classifications of the SDSSMOC4 and XSTPS-GAC (Xuyi Schmidt Telescope Photometric Survey of the Galactic Anti-Center) multi-color data samples, respectively. The results show that the two methods are effective and consistent in the case of large samples, and well consistent with the Carvano's result of S/C type classification, and that the a = 0 demarcation method is sensitive to the variation of sample space, but the method of cluster analysis is more stable.

  2. c-Type cytochromes and manganese oxidation in Pseudomonas putida MnB1

    SciTech Connect

    Caspi, R.; Tebo, B.M.; Haygood, M.G.

    1998-10-01

    Pseudomonas putida MnB1 is an isolate from an Mn oxide-encrusted pipeline that can oxidize Mn(II) to Mn oxides. The authors used transposon mutagenesis to construct mutants of strain MnB1 that are unable to oxidize manganese, and they characterized some of these mutants. The mutants were divided into three groups: mutants defective in the biogenesis of c-type cytochromes, mutants defective in genes that encode key enzymes of the tricarboxylic acid cycle, and mutants defective in the biosynthesis of tryptophan. The mutants in the first two groups were cytochrome c oxidase negative and did not contain c-type cytochromes. Mn(II) oxidation capability could be recovered in a c-type cytochrome biogenesis-defective mutant by complementation of the mutation.

  3. 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

  4. 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

  5. Momordica charantia seed lectin: toxicity, bacterial agglutination and antitumor properties.

    PubMed

    Kabir, Syed Rashel; Nabi, Md Mahamodun; Nurujjaman, Md; Abu Reza, Md; Alam, A H M Khurshid; Uz Zaman, Rokon; Khalid-Bin-Ferdaus, Khandaker Md; Amin, Ruhul; Khan, Md Masudul Hasan; Hossain, Md Anowar; Uddin, Md Salim; Mahmud, Zahid Hayat

    2015-03-01

    In last three decades, several studies were carried out on the D-galactose-specific lectin of Momordica charantia seeds (MCL). In the present study, in vitro growth inhibition (8-23 %) at different concentrations (6-24 μg/ml) of MCL was observed against Ehrlich ascites carcinoma (EAC) cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. MCL also showed 28, 45, and 75 % growth inhibitions against EAC cells when administered 1.2, 2.0, and 2.8 mg/kg/day (i.p.), respectively for five consequent days in vivo in mice. After lectin treatment, the level of red blood cell and hemoglobin was increased significantly with the decrease of white blood cell and maintained the normal level when compared with EAC-bearing control and normal mice without EAC cells. Although MCL caused cell cycle arrest at G0/G1 phase of EAC cells, any irregular shape or apoptotic morphological alterations in the lectin-treated EAC cells was not observed by an optical and fluorescence microscope. Lectin showed toxicity against brine shrimp nauplii with an LC50 value of 49.7 μg/ml. Four out of seven pathogenic bacteria were agglutinated by MCL in the absence of inhibitory sugar D-lactose/D-galactose. In conclusion, MCL showed strong cytotoxic effect and therefore can be used as a potent anticancer chemotherapeutic agent. PMID:25542240

  6. Cancer Biomarker Discovery: Lectin-Based Strategies Targeting Glycoproteins

    PubMed Central

    Clark, David; Mao, Li

    2012-01-01

    Biomarker discovery can identify molecular markers in various cancers that can be used for detection, screening, diagnosis, and monitoring of disease progression. Lectin-affinity is a technique that can be used for the enrichment of glycoproteins from a complex sample, facilitating the discovery of novel cancer biomarkers associated with a disease state. PMID:22710864

  7. Membrane adsorbers comprising grafted glycopolymers for targeted lectin binding

    PubMed Central

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

    2014-01-01

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

  8. Interaction of the tobacco lectin with histone proteins.

    PubMed

    Schouppe, Dieter; Ghesquière, Bart; Menschaert, Gerben; De Vos, Winnok H; Bourque, Stéphane; Trooskens, Geert; Proost, Paul; Gevaert, Kris; Van Damme, Els J M

    2011-03-01

    The tobacco (Nicotiana tabacum) agglutinin or Nictaba is a member of a novel class of plant lectins residing in the nucleus and the cytoplasm of tobacco cells. Since tobacco lectin expression is only observed after the plant has been subjected to stress situations such as jasmonate treatment or insect attack, Nictaba is believed to act as a signaling protein involved in the stress physiology of the plant. In this paper, a nuclear proteomics approach was followed to identify the binding partners for Nictaba in the nucleus and the cytoplasm of tobacco cv Xanthi cells. Using lectin affinity chromatography and pull-down assays, it was shown that Nictaba interacts primarily with histone proteins. Binding of Nictaba with histone H2B was confirmed in vitro using affinity chromatography of purified calf thymus histone proteins on a Nictaba column. Elution of Nictaba-interacting histone proteins was achieved with 1 m N-acetylglucosamine (GlcNAc). Moreover, mass spectrometry analyses indicated that the Nictaba-interacting histone proteins are modified by O-GlcNAc. Since the lectin-histone interaction was shown to be carbohydrate dependent, it is proposed that Nictaba might fulfill a signaling role in response to stress by interacting with O-GlcNAcylated proteins in the plant cell nucleus. PMID:21224338

  9. Antibiotic activity of lectins from marine algae against marine vibrios.

    PubMed

    Liao, W-R; Lin, J-Y; Shieh, W-Y; Jeng, W-L; Huang, R

    2003-07-01

    Saline and aqueous ethanol extracts of marine algae and the lectins from two red algal species were assayed for their antibiotic activity against marine vibrios. Experimental studies were also carried out on the influence of environmental factors on such activity, using batch cultures. The results indicated that many of the saline extracts of the algal species were active and that the activity was selective against those vibrios assayed. The algal extracts were active against Vibrio pelagius and the fish pathogen V. vulnificus, but inactive against V. neresis. Algal lectins from Eucheuma serra (ESA) and Galaxaura marginata (GMA) strongly inhibited V. vulnificus but were inactive against the other two vibrios. The antibacterial activity of algal extracts was inhibited by pretreatment with various sugars and glycoprotein. Extracts of the two red algae, E. serra and Pterocladia capillacea, in saline and aqueous ethanol, inhibited markedly the growth rate of V. vulnificus at very low concentrations. Culture results indicated that metabolites active against V. vulnificus were invariably produced in P. capillacea over a wide range of temperature, light intensity, and nutritional conditions. Enhanced antibacterial activity occurred when P. capillacea was grown under higher irradiance, severe nutrient stress and moderate temperature (20 degrees C), reflecting the specific antibiotic characteristics of this alga. The strong antibiotic activity of lectins towards fish pathogenic bacteria reveals one of the important roles played by algal lectins, as well as the potential high economic value of those marine algae assayed for aquaculture and for biomedical purposes. PMID:12884128

  10. Architectures of Multivalent Glycomimetics for Probing Carbohydrate-Lectin Interactions

    NASA Astrophysics Data System (ADS)

    Lahmann, Martina

    Well-defined multivalent glycoconjugates are valued tools in glycoscience and they are particularly valuable for the investigation of carbohydrate-lectin interactions. In addition to the relatively globularly shaped glycodendrimers many other designs have been realized. This chapter gives an overview on the common different architectures and their chemical synthesis by focussing on the achievements made since 2001.

  11. Vascular Relaxation Induced by C-Type Natriuretic Peptide Involves the Ca2+/NO-Synthase/NO Pathway

    PubMed Central

    Andrade, Fernanda A.; Restini, Carolina B. A.; Grando, Marcella D.; Ramalho, Leandra N. Z.; Bendhack, Lusiane M.

    2014-01-01

    Aims C-type natriuretic peptide (CNP) and nitric oxide (NO) are endothelium-derived factors that play important roles in the regulation of vascular tone and arterial blood pressure. We hypothesized that NO produced by the endothelial NO-synthase (NOS-3) contributes to the relaxation induced by CNP in isolated rat aorta via activation of endothelial NPR-C receptor. Therefore, the aim of this study was to investigate the putative contribution of NO through NPR-C activation in the CNP induced relaxation in isolated conductance artery. Main Methods Concentration-effect curves for CNP were constructed in aortic rings isolated from rats. Confocal microscopy was used to analyze the cytosolic calcium mobilization induced by CNP. The phosphorylation of the residue Ser1177 of NOS was analyzed by Western blot and the expression and localization of NPR-C receptors was analyzed by immunohistochemistry. Key Findings CNP was less potent in inducing relaxation in denuded endothelium aortic rings than in intact ones. L-NAME attenuated the potency of CNP and similar results were obtained in the presence of hydroxocobalamin, an intracellular NO0 scavenger. CNP did not change the phosphorylation of Ser1177, the activation site of NOS-3, when compared with control. The addition of CNP produced an increase in [Ca2+]c in endothelial cells and a decrease in [Ca2+]c in vascular smooth muscle cells. The NPR-C-receptors are expressed in endothelial and adventitial rat aortas. Significance These results suggest that CNP-induced relaxation in intact aorta isolated from rats involves NO production due to [Ca2+]c increase in endothelial cells possibly through NPR-C activation expressed in these cells. The present study provides a breakthrough in the understanding of the close relationship between the vascular actions of nitric oxide and CNP. PMID:24787693

  12. 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

  13. Dietary homocysteine promotes atherosclerosis in apoE-deficient mice by inducing scavenger receptors expression

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Elevated plasma homocysteine (Hcy) levels have been recognized as an independent risk factor for cardiovascular and cerebrovascular diseases. However, the causative mechanisms have not been delineated. Scavenger receptors such as scavenger receptor-AI/II (SR-A), CD36, and lectin-like oxidized LDL ...

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

    PubMed

    Nguyen, Cuong The; Tanaka, Kiwamu; Cao, Yangrong; Cho, Sung-Hwan; Xu, Dong; Stacey, Gary

    2016-01-01

    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 molecular 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. 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. PMID:27583834

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

    SciTech Connect

    Dharkar, Poorva D.; Anuradha, P.; Gaikwad, Sushama M.; Suresh, C. G.

    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 Bragg 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.

  16. Ligand preference and orientation in b- and c-type heme-binding proteins

    PubMed Central

    Fufezan, Christian; Zhang, Jun; Gunner, M. R.

    2009-01-01

    Hemes are often incorporated into designed proteins. The importance of the heme ligand type and its orientation is still a matter of debate. Here, heme ligands and ligand orientation were investigated using a nonredundant (87 structures) and a redundant (1503 structures) set of structures to compare and contrast design features of natural b- and c-type heme-binding proteins. Histidine is the most common ligand. Marked differences in ligation motifs between b- and c-type hemes are higher occurrence of His-Met in c-type heme binding motifs (16.4% vs. 1.4%) and higher occurrence of exchangeable, small molecules in b-type heme binding motifs (67.6% vs. 9.9%). Histidine ligands that are part of the c-type CXXCH heme-binding motif show a distinct asymmetric distribution of orientation. They tend to point between either the heme propionates or between the NA and NB heme nitrogens. Molecular mechanics calculations show that this asymmetry is due to the bonded constraints of the covalent attachment between the heme and the protein. In contrast, the orientations of b-type hemes histidine ligands are found evenly distributed with no preference. Observed histidine heme ligand orientations show no dominating influence of electrostatic interactions between the heme propionates and the ligands. Furthermore, ligands in bis-His hemes are found more frequently perpendicular rather than parallel to each other. These correlations support energetic constraints on ligands that can be used in designing proteins. PMID:18491383

  17. C-type virus particles in placenta of normal healthy Sprague-Dawley rats.

    PubMed Central

    Gross, L; Schidlovsky, G; Feldman, D; Dreyfuss, Y; Moore, L A

    1975-01-01

    C-type virus particles were found on electron-microscopic examination in placentas from two out of four young healthy Sprague-Dawley rats. One of these specimens contained virus particles budding from the plasma membranes of cells in the junctional zone of the placenta, i.e., the region where the fetal and maternal cell layers meet. In the other placenta, immature and mature C-type virus particles were found among cell debris also in the junctional region. This observation adds another species of animals to those recently reported, such as rhesus and baboon monkeys, as well as humans, in which C-type virus particles were found in the placenta. The presence of C-type viicant in view of the fact that a considerable number of these animals develop spontaneously a variety of malignant tumors, occasionally also leukemia and malignant lymphomas; however, none of these spontaneous tumors reveals the presence of virus particles on electron-microscopic examination. The nature of virus particles detected in rat placenta remains to be determined. As a working hypothesis, it is possible to assume that they may represent the passage of latent, presumably oncogenic, viruses transmitted "vertically" from parents to offspring. In the course of this passage some of them may be formed, emerging temporarily from their latency, before losing their identity and being again incorporated into the cell genetic components. Images PMID:171659

  18. Myeloid DAP12-associating lectin (MDL)-1 regulates synovial inflammation and bone erosion associated with autoimmune arthritis

    PubMed Central

    Joyce-Shaikh, Barbara; Bigler, Michael E.; Chao, Cheng-Chi; Murphy, Erin E.; Blumenschein, Wendy M.; Adamopoulos, Iannis E.; Heyworth, Paul G.; Antonenko, Svetlana; Bowman, Edward P.; McClanahan, Terrill K.; Phillips, Joseph H.

    2010-01-01

    DNAX adaptor protein 12 (DAP12) is a trans-membrane adaptor molecule that transduces activating signals in NK and myeloid cells. Absence of functional Dap12 results in osteoclast defects and bone abnormalities. Because DAP12 has no extracelluar binding domains, it must pair with cell surface receptors for signal transduction. There are at least 15 known DAP12-associating cell surface receptors with distinct temporal and cell type–specific expression patterns. Our aim was to determine which receptors may be important in DAP12-associated bone pathologies. Here, we identify myeloid DAP12-associating lectin (MDL)-1 receptor (also known as CLEC5A) as a key regulator of synovial injury and bone erosion during autoimmune joint inflammation. Activation of MDL-1 leads to enhanced recruitment of inflammatory macrophages and neutrophils to the joint and promotes bone erosion. Functional blockade of MDL-1 receptor via Mdl1 deletion or treatment with MDL-1-Ig fusion protein reduces the clinical signs of autoimmune joint inflammation. These findings suggest that MDL-1 receptor may be a therapeutic target for treatment of immune-mediated skeletal disorders. PMID:20212065

  19. Myeloid DAP12-associating lectin (MDL)-1 regulates synovial inflammation and bone erosion associated with autoimmune arthritis.

    PubMed

    Joyce-Shaikh, Barbara; Bigler, Michael E; Chao, Cheng-Chi; Murphy, Erin E; Blumenschein, Wendy M; Adamopoulos, Iannis E; Heyworth, Paul G; Antonenko, Svetlana; Bowman, Edward P; McClanahan, Terrill K; Phillips, Joseph H; Cua, Daniel J

    2010-03-15

    DNAX adaptor protein 12 (DAP12) is a trans-membrane adaptor molecule that transduces activating signals in NK and myeloid cells. Absence of functional Dap12 results in osteoclast defects and bone abnormalities. Because DAP12 has no extracelluar binding domains, it must pair with cell surface receptors for signal transduction. There are at least 15 known DAP12-associating cell surface receptors with distinct temporal and cell type-specific expression patterns. Our aim was to determine which receptors may be important in DAP12-associated bone pathologies. Here, we identify myeloid DAP12-associating lectin (MDL)-1 receptor (also known as CLEC5A) as a key regulator of synovial injury and bone erosion during autoimmune joint inflammation. Activation of MDL-1 leads to enhanced recruitment of inflammatory macrophages and neutrophils to the joint and promotes bone erosion. Functional blockade of MDL-1 receptor via Mdl1 deletion or treatment with MDL-1-Ig fusion protein reduces the clinical signs of autoimmune joint inflammation. These findings suggest that MDL-1 receptor may be a therapeutic target for treatment of immune-mediated skeletal disorders. PMID:20212065

  20. Comprehensive profiling of accessible surface glycans of mammalian sperm using a lectin microarray

    PubMed Central

    2014-01-01

    It is well known that cell surface glycans or glycocalyx play important roles in sperm motility, maturation and fertilization. A comprehensive profile of the sperm surface glycans will greatly facilitate both basic research (sperm glycobiology) and clinical studies, such as diagnostics of infertility. As a group of natural glycan binders, lectin is an ideal tool for cell surface glycan profiling. However, because of the lack of effective technology, only a few lectins have been tested for lectin-sperm binding profiles. To address this challenge, we have developed a procedure for high-throughput probing of mammalian sperm with 91 lectins on lectin microarrays. Normal sperm from human, boar, bull, goat and rabbit were collected and analyzed on the lectin microarrays. Positive bindings of a set of ~50 lectins were observed for all the sperm of 5 species, which indicated a wide range of glycans are on the surface of mammalian sperm. Species specific lectin bindings were also observed. Clustering analysis revealed that the distances of the five species according to the lectin binding profiles are consistent with that of the genome sequence based phylogenetic tree except for rabbit. The procedure that we established in this study could be generally applicable for sperm from other species or defect sperm from the same species. We believe the lectin binding profiles of the mammalian sperm that we established in this study are valuable for both basic research and clinical studies. PMID:24629138

  1. Properties of Lectins in the Root and Seed of Lotononis bainesii1

    PubMed Central

    Law, Ian J.; Strijdom, Barend W.

    1984-01-01

    A lectin was purified from the root of Lotononis bainesii Baker by affinity chromatography on Sepharose-blood group substance A + H. The molecular weight of the lectin was estimated by gel filtration to be 118,000. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that the lectin was a tetramer composed of two slightly different subunits with respective molecular weights of 32,000 and 35,000. The lectin had a hexose content of 12% (w/w) and contained the sugars fucose, glucosamine, mannose, and xylose. Root lectin hemagglutination was preferentially inhibited by disaccharides with terminal nonreducing galactose residues. Antigens capable of cross-reaction with root lectin antibody were not detected in the seed of L. bainesii. A lectin from the seed of L. bainesii was partially purified by adsorption to pronase-treated rabbit erythrocytes. The lectin preparation had a molecular weight of approximately 200,000. Galactose and galactono-1,4-lactone inhibited seed lectin hemagglutination but lactose was ineffective. There was no evidence that the root of L. bainesii contained material antigenically related to the seed lectin. Images Fig. 2 Fig. 4 Fig. 5 PMID:16663508

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

    PubMed

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

    2015-01-01

    Lectins are non-immunoglobulin carbohydrate-binding proteins without enzymatic activity towards the bound carbohydrates. Many lectins of e.g. plants or fungi have been suggested to act as toxins to defend the host against predators and parasites. We have previously shown that the Coprinopsis cinerea lectin 2 (CCL2), which binds to α1,3-fucosylated N-glycan cores, is toxic to Caenorhabditis elegans and results in developmental delay and premature death. In this study, we investigated the underlying toxicity phenotype at the cellular level by electron and confocal microscopy. We found that CCL2 directly binds to the intestinal apical surface and leads to a highly damaged brush border with loss of microvilli, actin filament depolymerization, and invaginations of the intestinal apical plasma membrane through gaps in the terminal web. We excluded several possible toxicity mechanisms such as internalization and pore-formation, suggesting that CCL2 acts directly on intestinal apical plasma membrane or glycocalyx proteins. A genetic screen for C. elegans mutants resistant to CCL2 generated over a dozen new alleles in bre 1, ger 1, and fut 1, three genes required for the synthesis of the sugar moiety recognized by CCL2. CCL2-induced intestinal brush border defects in C. elegans are similar to the damage observed previously in rats after feeding the dietary lectins wheat germ agglutinin or concanavalin A. The evolutionary conserved reaction of the brush border between mammals and nematodes might allow C. elegans to be exploited as model organism for the study of dietary lectin-induced intestinal pathology in mammals. PMID:26057124

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

    PubMed Central

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

    2015-01-01

    Lectins are non-immunoglobulin carbohydrate-binding proteins without enzymatic activity towards the bound carbohydrates. Many lectins of e.g. plants or fungi have been suggested to act as toxins to defend the host against predators and parasites. We have previously shown that the Coprinopsis cinerea lectin 2 (CCL2), which binds to α1,3-fucosylated N-glycan cores, is toxic to Caenorhabditis elegans and results in developmental delay and premature death. In this study, we investigated the underlying toxicity phenotype at the cellular level by electron and confocal microscopy. We found that CCL2 directly binds to the intestinal apical surface and leads to a highly damaged brush border with loss of microvilli, actin filament depolymerization, and invaginations of the intestinal apical plasma membrane through gaps in the terminal web. We excluded several possible toxicity mechanisms such as internalization and pore-formation, suggesting that CCL2 acts directly on intestinal apical plasma membrane or glycocalyx proteins. A genetic screen for C. elegans mutants resistant to CCL2 generated over a dozen new alleles in bre 1, ger 1, and fut 1, three genes required for the synthesis of the sugar moiety recognized by CCL2. CCL2-induced intestinal brush border defects in C. elegans are similar to the damage observed previously in rats after feeding the dietary lectins wheat germ agglutinin or concanavalin A. The evolutionary conserved reaction of the brush border between mammals and nematodes might allow C. elegans to be exploited as model organism for the study of dietary lectin-induced intestinal pathology in mammals. PMID:26057124

  4. Use of Phaseolus vulgaris leukoagglutinating lectin in histochemical and blotting techniques: a comparison of digoxigenin- and biotin-labelled lectins.

    PubMed

    Li, W P; Zuber, C; Roth, J

    1993-11-01

    An increase in the number of beta 1,6 branches of the trimannosyl core of asparagine-linked oligosaccharides has been shown to be directly correlated with the metastatic potential of cultured tumour cells. The Phaseolus vulgaris leukoagglutinating lectin (PHA-L) binds to beta 1,6 branches of tri- and tetra-antennary oligosaccharides. We have applied digoxigenin- and biotin-conjugated PHA-L to establish a non-radioactive detection system for beta 1,6 branches, which can be used in lectin blotting as well as light and electron microscopic cytochemistry. For this purpose the HCT116 human colon carcinoma cell line and colon carcinoma tissue were investigated. Digoxigenin-conjugated PHA-L in conjunction with alkaline phosphatase-conjugated anti-digoxigenin antibodies was superior to biotin-conjugated PHA-L in lectin blotting with respect to sensitivity and specificity. Similarly, the digoxigenin conjugated PHA-L in conjunction with gold-labelled anti-digoxigenin antibodies resulted in more intense specific staining and lower background compared to biotin-conjugated PHA-L visualized with a streptavidin immunogold complex. The specificity of lectin binding in blotting and cytochemical studies was demonstrated by the absence of staining when the lectin was omitted or preabsorbed with glycoprotein, and following pretreatment of the cellular homogenates or tissue sections by N-glycosidase F. Our results demonstrate that digoxigenin-conjugated PHA-L provides high sensitivity and specificity for histochemical and blotting techniques and is amenable for quantification. The technique should have applications in tumour research. PMID:7508428

  5. Solution structure of the lymphocyte receptor Nkrp1a reveals a distinct conformation of the long loop region as compared to in the crystal structure.

    PubMed

    Rozbeský, Daniel; Adámek, David; Pospíšilová, Eliška; Novák, Petr; Chmelík, Josef

    2016-09-01

    Mouse Nkrp1a receptor is a C-type lectin-like receptor expressed on the surface of natural killer cells that play an important role against virally infected and tumor cells. The recently solved crystal structure of Nkrp1a raises questions about a long loop region which was uniquely extended from the central region in the crystal. To understand the functional significance of the loop, the solution structure of Nkrp1a using nuclear magnetic resonance (NMR) spectroscopy was determined. A notable difference between the crystal and NMR structure of Nkrp1a appears in the conformation of the long loop region. While the extended loop points away from the central core and mediates formation of a domain swapped dimer in the crystal, the solution structure is monomeric with the loop tightly anchored to the central region. The findings described the first solution structure in the Nkrp1 family and revealed intriguing similarities and differences to the crystal structure. Proteins 2016; 84:1304-1311. © 2016 Wiley Periodicals, Inc. PMID:27238500

  6. Adhesion molecules of cultured hematopoietic malignancies. A calcium-dependent lectin is the principle mediator of binding to the high endothelial venule of lymph nodes.

    PubMed Central

    Stoolman, L M; Ebling, H

    1989-01-01

    This study documents that a calcium-dependent phosphomanosyl-binding site on human lymphoid malignancies mediates attachment to the peripheral node high endothelial venule (PNHEV). The phorbol ester PMA coordinately upregulates lectin activity and binding to the PNHEV in the human T-lymphoblastic cell line Jurkat but not in the less phenotypically mature lines HSB2, Molt4, CEM, and HPB-ALL. In contrast, expression of CD18, CD2, and several common epitopes of the putative adhesion receptor gp90Hermes (CD44) did not correlate with attachment to PNHEV in this series of cell lines. Insensitivity to inhibition by the CD18 MAb TS 1.18, temperature and divalent cation requirements further distinguish the Jurkat-PNHEV adhesive interaction from CD11a/18- and CD2-mediated adhesion. The PMA-induced phenotypic changes in the Jurkat line parallel late thymocyte differentiation as well as lymphocyte activation, suggesting that expression of the endothelial-binding lectin may be linked to one or both of these processes. The lectin-like activity on Jurkat cells is functionally indistinguishable from those previously linked to PNHEV recognition in normal human lymphocytes, normal rat lymphocytes and both normal and malignant murine lymphoid cells. In the mouse, this activity is either contained in or functionally linked to a member of the LEC-CAM family gp90Mel14, suggesting that Jurkat cells express the human homologue of the murine nodal homing receptor. Thus cultured T lymphoblastic malignancies express a variety of potential endothelial adhesion molecules but use primarily a highly conserved surface lectin to interact with PNHEV. Images PMID:2794056

  7. Functional environmental proteomics: elucidating the role of a c-type cytochrome abundant during uranium bioremediation.

    PubMed

    Yun, Jiae; Malvankar, Nikhil S; Ueki, Toshiyuki; Lovley, Derek R

    2016-02-01

    Studies with pure cultures of dissimilatory metal-reducing microorganisms have demonstrated that outer-surface c-type cytochromes are important electron transfer agents for the reduction of metals, but previous environmental proteomic studies have typically not recovered cytochrome sequences from subsurface environments in which metal reduction is important. Gel-separation, heme-staining and mass spectrometry of proteins in groundwater from in situ uranium bioremediation experiments identified a putative c-type cytochrome, designated Geobacter subsurface c-type cytochrome A (GscA), encoded within the genome of strain M18, a Geobacter isolate previously recovered from the site. Homologs of GscA were identified in the genomes of other Geobacter isolates in the phylogenetic cluster known as subsurface clade 1, which predominates in a diversity of Fe(III)-reducing subsurface environments. Most of the gscA sequences recovered from groundwater genomic DNA clustered in a tight phylogenetic group closely related to strain M18. GscA was most abundant in groundwater samples in which Geobacter sp. predominated. Expression of gscA in a strain of Geobacter sulfurreducens that lacked the gene for the c-type cytochrome OmcS, thought to facilitate electron transfer from conductive pili to Fe(III) oxide, restored the capacity for Fe(III) oxide reduction. Atomic force microscopy provided evidence that GscA was associated with the pili. These results demonstrate that a c-type cytochrome with an apparent function similar to that of OmcS is abundant when Geobacter sp. are abundant in the subsurface, providing insight into the mechanisms for the growth of subsurface Geobacter sp. on Fe(III) oxide and suggesting an approach for functional analysis of other Geobacter proteins found in the subsurface. PMID:26140532

  8. Voltage-Dependent C-Type Inactivation in a Constitutively Open K+ Channel

    PubMed Central

    Panaghie, Gianina; Purtell, Kerry; Tai, Kwok-Keung; Abbott, Geoffrey W.

    2008-01-01

    Most voltage-gated potassium (Kv) channels undergo C-type inactivation during sustained depolarization. The voltage dependence and other mechanistic aspects of this process are debated, and difficult to elucidate because of concomitant voltage-dependent activation. Here, we demonstrate that MinK-KCNQ1 (IKs) channels with an S6-domain mutation, F340W in KCNQ1, exhibit constitutive activation but voltage-dependent C-type inactivation. F340W-IKs inactivation was sensitive to extracellular cation concentration and species, and it altered ion selectivity, suggestive of pore constriction. The rate and extent of F340W-IKs inactivation and recovery from inactivation were voltage-dependent with physiologic intracellular ion concentrations, and in the absence or presence of external K+, with an estimated gating charge, zi, of ∼1. Finally, double-mutant channels with a single S4 charge neutralization (R231A,F340W-IKs) exhibited constitutive C-type inactivation. The results suggest that F340W-IKs channels exhibit voltage-dependent C-type inactivation involving S4, without the necessity for voltage-dependent opening, allosteric coupling to voltage-dependent S6 transitions occurring during channel opening, or voltage-dependent changes in ion occupancy. The data also identify F340 as a critical hub for KCNQ1 gating processes and their modulation by MinK, and present a unique system for further mechanistic studies of the role of coupling of C-type inactivation to S4 movement, without contamination from voltage-dependent activation. PMID:18567635

  9. Expression and purification of soluble and stable ectodomain of natural killer cell receptor LLT1 through high-density transfection of suspension adapted HEK293S GnTI(-) cells.

    PubMed

    Bláha, Jan; Pachl, Petr; Novák, Petr; Vaněk, Ondřej

    2015-05-01

    Lectin-like transcript 1 (LLT1, gene clec2d) was identified to be a ligand for the single human NKR-P1 receptor present on NK and NK-T lymphocytes. Naturally, LLT1 is expressed on the surface of NK cells, stimulating IFN-γ production, and is up-regulated upon activation of other immune cells, e.g. TLR-stimulated dendritic cells and B cells or T cell receptor-activated T cells. While in normal tissues LLT1:NKR-P1 interaction (representing an alternative "missing-self" recognition system) play an immunomodulatory role in regulation of crosstalk between NK and antigen presenting cells, LLT1 is upregulated in glioblastoma cells, one of the most lethal tumors, where it acts as a mediator of immune escape of glioma cells. Here we report transient expression and characterization of soluble His176Cys mutant of LLT1 ectodomain in an eukaryotic expression system of human suspension-adapted HEK293S GnTI(-) cell line with uniform N-glycans. The His176Cys mutation is critical for C-type lectin-like domain stability, leading to the reconstruction of third canonical disulfide bridge in LLT1, as shown by mass spectrometry. Purified soluble LLT1 is homogeneous, deglycosylatable and forms a non-covalent homodimer whose dimerization is not dependent on presence of its N-glycans. As a part of production of soluble LLT1, we have adapted HEK293S GnTI(-) cell line to growth in suspension in media facilitating transient transfection and optimized novel high cell density transfection protocol, greatly enhancing protein yields. This transfection protocol is generally applicable for protein production within this cell line, especially for protein crystallography. PMID:25623399

  10. Photoswitchable precision glycooligomers and their lectin binding

    PubMed Central

    Ponader, Daniela; Igde, Sinaida; Wehle, Marko; Märker, Katharina; Santer, Mark

    2014-01-01

    Summary The synthesis of photoswitchable glycooligomers is presented by applying solid-phase polymer synthesis and functional building blocks. The obtained glycoligands are monodisperse and present azobenzene moieties as well as sugar ligands at defined positions within the oligomeric backbone and side chains, respectively. We show that the combination of molecular precision together with the photoswitchable properties of the azobenzene unit allows for the photosensitive control of glycoligand binding to protein receptors. These stimuli-sensitive glycoligands promote the understanding of multivalent binding and will be further developed as novel biosensors. PMID:25161717

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

    PubMed

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

    2015-02-01

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

  12. 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

  13. 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.

  14. Leguminous lectins as tools for studying the role of sugar residues in leukocyte recruitment.

    PubMed Central

    Alencar, N M; Teixeira, E H; Assreuy, A M; Cavada, B S; Flores, C A; Ribeiro, R A

    1999-01-01

    The natural physiological ligands for selectins are oligosaccharides found in glycoprotein or glycolipid molecules in cell membranes. In order to study the role of sugar residues in the in vivo lectin anti-inflammatory effect, we tested three leguminous lectins with different carbohydrate binding affinities in the peritonitis and paw oedema models induced by carrageenin in rats. L. sericeus lectin was more anti-inflammatory than D. virgata lectin, the effects being reversed by their specific binding sugars (N-acetylglucosamine and alpha-methylmannoside, respectively). However, V. macrocarpa, a galactose-specific lectin, was not anti-inflammatory. The proposed anti-inflammatory activity of lectins could be due to a blockage of neutrophil-selectin carbohydrate ligands. Thus, according to the present data, we suggest an important role for N-acetylglucosamine residue as the major ligand for selectins on rat neutrophil membranes. PMID:10704148

  15. C-type natriuretic peptide inhibits leukocyte recruitment and platelet-leukocyte interactions via suppression of P-selectin expression

    NASA Astrophysics Data System (ADS)

    Scotland, Ramona S.; Cohen, Marc; Foster, Paul; Lovell, Matthew; Mathur, Anthony; Ahluwalia, Amrita; Hobbs, Adrian J.

    2005-10-01

    The multifaceted process of immune cell recruitment to sites of tissue injury is key to the development of an inflammatory response and involved in the pathogenesis of numerous cardiovascular disorders. We recently identified C-type natriuretic peptide (CNP) as an important endothelium-derived mediator that regulates vascular tone and protects against myocardial ischemia/reperfusion injury. Herein, we investigated whether CNP inhibits leukocyte recruitment and platelet aggregation and thereby exerts a potential antiinflammatory influence on the blood vessel wall. We assessed the effects of CNP on leukocyte-endothelial cell interactions in mouse mesenteric postcapillary venules in vivo in animals with high basal leukocyte activation (endothelial nitric oxide synthase knockout mice, eNOS-/-) or under acute inflammatory conditions (induced by interleukin-1 or histamine). CNP suppressed basal leukocyte rolling in eNOS-/- mice in a rapid, reversible, and concentration-dependent manner. These effects of CNP were mimicked by the selective natriuretic peptide receptor-C agonist cANF4-23. CNP also suppressed leukocyte rolling induced by IL-1 or histamine, inhibited platelet-leukocyte interactions, and prevented thrombin-induced platelet aggregation of human blood. Furthermore, analysis of human umbilical vein endothelial cells, leukocytes, and platelets revealed that CNP selectively attenuates expression of P-selectin. Thus, CNP is a modulator of acute inflammation in the blood vessel wall characterized by leukocyte and platelet activation. These antiinflammatory effects appear to be mediated, at least in part, via suppression of P-selectin expression. These observations suggest that endothelial CNP might maintain an anti-atherogenic influence on the blood vessel wall and represent a target for therapeutic intervention in inflammatory cardiovascular disorders. endothelium | natriuretic peptide receptor type C | atherosclerosis | thrombosis

  16. Exploitation of lectinized lipo-polymerosome encapsulated Amphotericin B to target macrophages for effective chemotherapy of visceral leishmaniasis.

    PubMed

    Gupta, Pramod K; Asthana, Shalini; Jaiswal, Anil K; Kumar, Vivek; Verma, Ashwni K; Shukla, Prashant; Dwivedi, Pankaj; Dube, Anuradha; Mishra, Prabhat R

    2014-06-18

    We have designed lectin functionalized Lipo-polymerosome bearing Amphotericin B (Lec-AmB-L-Psome) for specific internalization via lectin receptors overexpressed on infected macrophages of mononuclear phagocytic system (MPS) for the effective management of intramacrophage diseases such as visceral leishmaniasis. The lipo-polymerosome composed of glycol chitosan-stearic acid copolymer (GC-SA25%) and model lipid cholesterol was surface-functionalized with lectin by the EDC/NHS carbodiimide coupling method. Our designed Lec-AmB-L-Psome showed >2-fold enhanced uptake and significantly higher internalization in macrophages as compared to AmB-L-Psome. Importantly, pharmacokinetic and organ distribution studies illustrate significantly higher accumulation of Lec-AmB-L-Psome in MPS especially in liver, spleen, and lung as compared to AmB-L-Psome, Ambisome, and Fungizone. The IC50 value demonstrated that Lec-AmB-L-Psome has 1.63, 2.23, and 3.43 times higher activity than AmB-L-Psome (p < 0.01), Ambisome (p < 0.05), and Fungizone (p < 0.05), respectively. Additionally, the Lec-AmB-L-Psome showed significantly higher splenic parasite inhibition (78.66 ± 3.08%) compared to Fungizone and Ambisome that caused only 56.54 ± 3.91% (p < 0.05) and 66.46 ± 2.08% (p < 0.05) parasite inhibition, respectively, in Leishmania-infected hamsters. The toxicity profile revealed that Lec-AmB-L-Psome is a safe delivery system with diminished nephrotoxicity which is a limiting factor of Fungizone application. Taken together, these studies suggest that this surface functionalized self-assembled Lec-AmB-L-Psome can introduce a new platform to specifically target macrophages for effective management of intramacrophage diseases. PMID:24842628

  17. Binding profiles and cytokine-inducing effects of fish rhamnose-binding lectins on Burkitt's lymphoma Raji cells.

    PubMed

    Hosono, Masahiro; Sugawara, Shigeki; Matsuda, Atsushi; Tatsuta, Takeo; Koide, Yasuhiro; Hasan, Imtiaj; Hasan, Imtiaji; Ozeki, Yasuhiro; Nitta, Kazuo

    2014-10-01

    Rhamnose-binding lectin (RBL) is one of the animal lectin categories which take part in the innate immune responses of fish. Osmerus lanceolatus lectin (OLL) from shishamo smelt eggs is an RBL composed of two tandem-repeated domains, both of which are considered to be a carbohydrate-recognition domain. SAL, catfish (Silurus asotus) egg RBL composed of three domains, binds to Burkitt's lymphoma Raji cells through globotriaosylceramide (Gb3) carbohydrate chain and to reduce cell size and growth by altering membrane composition without causing cell death. In this experiment, we tried to compare the binding effects of these two RBLs on Raji cells. Flow cytometric and fluorescence microscopic analyses revealed that OLL also directly bound to and shrunk Raji cells with ten times less reactivity than SAL but reduced cell growth with decreasing cell viability. Anti-Gb3 antibody completely blocked the binding of SAL to Raji cells but not that of OLL. In addition, the direct bindings of OLL and SAL to Raji cells were comparably inhibited by melibiose, but lactose was more effective inhibitor for the binding of OLL than that of SAL. These results suggest that OLL has slightly different cell-binding property compared with SAL and binds not only to Gb3 but also to the other carbohydrate receptor-bearing β-galactoside chains. The quantitative RT-PCR analysis revealed that SAL induced the expression of TNF-α but not of IFN-γ, IL-1β, and IL-10. Thus, SAL-induced cytostatic effect on Raji cells might be partially caused by TNF-α-mediated signaling pathway. PMID:24861899

  18. Sialic acid and sialyl-lactose glyco-conjugates: design, synthesis and binding assays to lectins and swine influenza H1N1 virus.

    PubMed

    Zevgiti, Stella; Zabala, Juliana Gonzalez; Darji, Ayub; Dietrich, Ursula; Panou-Pomonis, Eugenia; Sakarellos-Daitsiotis, Maria

    2012-01-01

    The terminal parts of the influenza hemagglutinin (HA) receptors α2,6- and α2,3-sialyllactoses were conjugated to an artificial carrier, named sequential oligopeptide carrier (SOC(4) ), to formulate human and avian receptor mimics, respectively. SOC(4) , formed by the tripeptide unit Lys-Aib-Gly, adopts a rigid helicoids-type conformation, which enables the conjugation of biomolecules to the Lys-N(ε) H(2) groups. By doing so, it preserves their initial conformations and functionalities of the epitopes. We report that SOC(4) -glyco-conjugate bearing two copies of the α2,6-sialyllactose is specifically recognized by the biotinylated Sambucus nigra (elderberry) bark lectin, which binds preferentially to sialic acid in an α2,6-linkage. SOC(4) -glyco-conjugate bearing two copies of the α2,3-sialyllactose was not recognized by the biotinylated Maackia amurensis lectin, despite its well-known α2,3-sialyl bond specificity. However, preliminary immune blot assays showed that H1N1 virus binds to both the SOC(4) -glyco-conjugates immobilized onto nitrocellulose membrane. It is concluded that Ac-SOC(4) [(Ac)(2) ,(3'SL-Aoa)(2) ]-NH(2) 5 and Ac-SOC(4) [(Ac)(2) ,(6'SL-Aoa)(2) ]-NH(2) 6 mimic the HA receptors. These findings could be useful for easy screening of binding and inhibition assays of virus-receptor interactions. PMID:22052803

  19. Functional Specialty of CD40 and Dendritic Cell Surface Lectins for Exogenous Antigen Presentation to CD8(+) and CD4(+) T Cells.

    PubMed

    Yin, Wenjie; Gorvel, Laurent; Zurawski, Sandra; Li, Dapeng; Ni, Ling; Duluc, Dorothée; Upchurch, Katherine; Kim, JongRok; Gu, Chao; Ouedraogo, Richard; Wang, Zhiqing; Xue, Yaming; Joo, HyeMee; Gorvel, Jean-Pierre; Zurawski, Gerard; Oh, SangKon

    2016-03-01

    Dendritic cells (DCs) are major antigen-presenting cells that can efficiently prime and cross-prime antigen-specific T cells. Delivering antigen to DCs via surface receptors is thus an appealing strategy to evoke cellular immunity. Nonetheless, which DC surface receptor to target to yield the optimal CD8(+) and CD4(+) T cell responses remains elusive. Herein, we report the superiority of CD40 over 9 different lectins and scavenger receptors at evoking antigen-specific CD8(+) T cell responses. However, lectins (e.g., LOX-1 and Dectin-1) were more efficient than CD40 at eliciting CD4(+) T cell responses. Common and distinct patterns of subcellular and intracellular localization of receptor-bound αCD40, αLOX-1 and αDectin-1 further support their functional specialization at enhancing antigen presentation to either CD8(+) or CD4(+) T cells. Lastly, we demonstrate that antigen targeting to CD40 can evoke potent antigen-specific CD8(+) T cell responses in human CD40 transgenic mice. This study provides fundamental information for the rational design of vaccines against cancers and viral infections. PMID:27077111

  20. Functional Specialty of CD40 and Dendritic Cell Surface Lectins for Exogenous Antigen Presentation to CD8+ and CD4+ T Cells

    PubMed Central

    Yin, Wenjie; Gorvel, Laurent; Zurawski, Sandra; Li, Dapeng; Ni, Ling; Duluc, Dorothée; Upchurch, Katherine; Kim, JongRok; Gu, Chao; Ouedraogo, Richard; Wang, Zhiqing; Xue, Yaming; Joo, HyeMee; Gorvel, Jean-Pierre; Zurawski, Gerard; Oh, SangKon

    2016-01-01

    Dendritic cells (DCs) are major antigen-presenting cells that can efficiently prime and cross-prime antigen-specific T cells. Delivering antigen to DCs via surface receptors is thus an appealing strategy to evoke cellular immunity. Nonetheless, which DC surface receptor to target to yield the optimal CD8+ and CD4+ T cell responses remains elusive. Herein, we report the superiority of CD40 over 9 different lectins and scavenger receptors at evoking antigen-specific CD8+ T cell responses. However, lectins (e.g., LOX-1 and Dectin-1) were more efficient than CD40 at eliciting CD4+ T cell responses. Common and distinct patterns of subcellular and intracellular localization of receptor-bound αCD40, αLOX-1 and αDectin-1 further support their functional specialization at enhancing antigen presentation to either CD8+ or CD4+ T cells. Lastly, we demonstrate that antigen targeting to CD40 can evoke potent antigen-specific CD8+ T cell responses in human CD40 transgenic mice. This study provides fundamental information for the rational design of vaccines against cancers and viral infections. PMID:27077111

  1. Fucose-binding Lotus tetragonolobus lectin binds to human polymorphonuclear leukocytes and induces a chemotactic response.

    PubMed

    VanEpps, D E; Tung, K S

    1977-09-01

    Fucose-binding L. tetragonolobus lectin to the surface of human polymorphonuclear leukocytes (PMN) and induces a chemotactic response. Both surface binding and chemotaxis are inhibited by free fucose but not by fructose, mannose, or galactose. The lectin-binding sites on PMN are unrelated to the A, B, or O blood group antigen. Utilization of this lectin should be a useful tool in isolating PMN membrane components and in analyzing the mechanism of neutrophil chemotaxis. PMID:330752

  2. Large Scale Magnetic Separation of Solanum tuberosum Tuber Lectin from Potato Starch Waste Water

    NASA Astrophysics Data System (ADS)

    Safarik, Ivo; Horska, Katerina; Martinez, Lluis M.; Safarikova, Mirka

    2010-12-01

    A simple procedure for large scale isolation of Solanum tuberosum tuber lectin from potato starch industry waste water has been developed. The procedure employed magnetic chitosan microparticles as an affinity adsorbent. Magnetic separation was performed in a flow-through magnetic separation system. The adsorbed lectin was eluted with glycine/HCl buffer, pH 2.2. The specific activity of separated lectin increased approximately 27 times during the isolation process.

  3. Isolation of an immunosuppressive lectin from Phaseolus vulgaris L. cv Cacahuate using stroma.

    PubMed

    Vargas-Albores, F; Hernández, J; Córdoba, F; Zenteno, E

    1993-11-01

    An immunosuppressive lectin was isolated from seed of Phaseolus vulgaris cv Cacahuate using physically entrapped stroma. The lectin was found to be a 94 kDa tetrameric protein. When 50 micrograms, of this lectin were administered intraperitoneally 2 days before the immunization with sheep red blood cells, humoral response against the immunogen was completely inhibited. Other properties of the protein are discussed. PMID:8248029

  4. [Studies on the location of eight lectins in breast carcinoma].

    PubMed

    Zheng, Z; Ji, Z M

    1990-12-01

    100 cases of breast carcinoma were studied with lectin affinitive histochemistry technology. The result showed that Ricinus comunis agglutinin (RCA1) was located in almost all intraductal carcinomas but one, while the positive rates in the other types were obviously low (P less than 0.05). The positive rate of Ulex europaeus agglutinin-I (UEA1) in well-differentiated types was higher than that in poorly-differentiated ones (P less than 0.05). The location of Peanut agglutinin (PNA), Bandeiraea Simplicifolia (BSL) and UEA1 in breast carcinomas exhibited some regularity and it might be useful in understanding the differentiation of breast carcinomas. No relationship between changes of the eight lectins and metastases in axillary lymph nodes was observed, but the authors considered that PNA-affinitive histochemistry was beneficial to the detection of micrometastases in lymph nodes. PMID:1964401

  5. How a plant lectin recognizes high mannose oligosaccharides.

    PubMed

    Garcia-Pino, Abel; Buts, Lieven; Wyns, Lode; Imberty, Anne; Loris, Remy

    2007-08-01

    The crystal structure of Pterocarpus angolensis seed lectin is presented in complex with a series of high mannose (Man) oligosaccharides ranging from Man-5 to Man-9. Despite that several of the nine Man residues of Man-9 have the potential to bind in the monosaccharide-binding site, all oligomannoses are bound in the same unique way, employing the tetrasaccharide sequence Manalpha(1-2)Manalpha(1-6)[Manalpha(1-3)]Manalpha(1-. Isothermal titration calorimetry titration experiments using Man-5, Man-9, and the Man-9-containing glycoprotein soybean (Glycine max) agglutinin as ligands confirm the monovalence of Man-9 and show a 4-times higher affinity for Man-9 when it is presented to P. angolensis seed lectin in a glycoprotein context. PMID:17556509

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

    SciTech Connect

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

    2006-12-01

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

  7. Bishydrazide glycoconjugates for lectin recognition and capture of bacterial pathogens.

    PubMed

    Adak, Avijit Kumar; Leonov, Alexei P; Ding, Ning; Thundimadathil, Jyothi; Kularatne, Sumith; Low, Philip S; Wei, Alexander

    2010-11-17

    Bishydrazides are versatile linkers for attaching glycans to substrates for lectin binding and pathogen detection schemes. The α,ω-bishydrazides of carboxymethylated hexa(ethylene glycol) (4) can be conjugated at one end to unprotected oligosaccharides, then attached onto carrier proteins, tethered onto activated carboxyl-terminated surfaces, or functionalized with a photoactive cross-linking agent for lithographic patterning. Glycoconjugates of bishydrazide 4 can also be converted into dithiocarbamates (DTCs) by treatment with CS(2) under mild conditions, for attachment onto gold substrates. The immobilized glycans serve as recognition elements for cell-surface lectins and enable the detection and capture of bacterial pathogens such as Pseudomonas aeruginosa by their adsorption onto micropatterned substrates. A detection limit of 10³ cfu/mL is demonstrated, using a recently introduced method based on optical pattern recognition. PMID:20925370

  8. Bishydrazide Glycoconjugates for Lectin Recognition and Capture of Bacterial Pathogens

    PubMed Central

    Adak, Avijit Kumar; Leonov, Alexei P.; Ding, Ning; Thundimadathil, Jyothi; Kularatne, Sumith; Low, Philip S.; Wei, Alexander

    2010-01-01

    Bishydrazides are versatile linkers for attaching glycans to substrates for lectin binding and pathogen detection schemes. The α,ω-bishydrazides of carboxymethylated hexaethylene glycol (4) can be conjugated at one end to unprotected oligosaccharides, then attached onto carrier proteins, tethered onto activated carboxyl-terminated surfaces, or functionalized with a photoactive crosslinking agent for lithographic patterning. Glycoconjugates of bishydrazide 4 can also be converted into dithiocarbamates (DTCs) by treatment with CS2 under mild conditions, for attachment onto gold substrates. The immobilized glycans serve as recognition elements for cell-surface lectins and enable the detection and capture of bacterial pathogens such as Psuedomonas aeruginosa by their adsorption onto micropatterned substrates. A detection limit of 103 cfu/mL is demonstrated, using a recently introduced method based on optical pattern recognition. PMID:20925370

  9. Lectin-dependent neutrophil-mediated cytotoxicity. I. Characteristics.

    PubMed Central

    Simchowitz, L; Schur, P H

    1976-01-01

    Isolated normal human peripheral neutrophils became cytotoxic to chicken red blood cells (CRBC) in the presence of phytohaemagglutinin (PHA) and concanavalin A (Con A), a phenomenon which we have termed lectin-dependent neutrophilmediated cytotoxicity (LDNMC). Substantial cytotoxicity could be demonstrated by 1 h of incubation at 37 degrees. Isolated human peripheral lymphocytes were not cytotoxic to CRBC in the presence of these lectins, even after 18 h of incubation. Both PHA and Con A exhibited dose responses over a wide concentration range and displayed progressive, time-dependent cytotoxicity. Cytotoxicity for both PHA and Con A was greater at 37 degrees than at 22 degrees, and was undetectable at 4 degrees. CRBC as target cells were much more readily lysed than either sheep or human erythrocytes. Erythrophagocytosis did not appear to play a role. Images Figure 1 PMID:955680

  10. Antibacterial activity of a lectin-like Burkholderia cenocepacia protein.

    PubMed

    Ghequire, Maarten G K; De Canck, Evelien; Wattiau, Pierre; Van Winge, Iris; Loris, Remy; Coenye, Tom; De Mot, René

    2013-08-01

    Bacteriocins of the LlpA family have previously been characterized in the γ-proteobacteria Pseudomonas and Xanthomonas. These proteins are composed of two MMBL (monocot mannose-binding lectin) domains, a module predominantly and abundantly found in lectins from monocot plants. Genes encoding four different types of LlpA-like proteins were identified in genomes from strains belonging to the Burkholderia cepacia complex (Bcc) and the Burkholderia pseudomallei group. A selected recombinant LlpA-like protein from the human isolate Burkholderia cenocepacia AU1054 displayed narrow-spectrum genus-specific antibacterial activity, thus representing the first functionally characterized bacteriocin within this β-proteobacterial genus. Strain-specific killing was confined to other members of the Bcc, with mostly Burkholderia ambifaria strains being susceptible. In addition to killing planktonic cells, this bacteriocin also acted as an antibiofilm agent. PMID:23737242

  11. Properties of volkensin, a toxic lectin from Adenia volkensii.

    PubMed

    Stirpe, F; Barbieri, L; Abbondanza, A; Falasca, A I; Brown, A N; Sandvig, K; Olsnes, S; Pihl, A

    1985-11-25