Sample records for complement lectin pathway

  1. Ficolins and the lectin complement pathway.

    PubMed

    Matsushita, M; Fujita, T

    2001-04-01

    Ficolins, found in various tissues, are a group of proteins containing both a collagen-like and a fibrinogen-like domain. Recently, it was shown that ficolins present in serum are lectins with a common binding specificity for N-acetylglucosamine (GlcNAc). The fibrinogen-like domain is responsible for the carbohydrate binding. Mannose-binding lectin (MBL) is also a collagenous lectin in serum that is specific for GlcNAc and mannose binding. Its domain organization is similar to that of ficolins, except that MBL has a carbohydrate-recognition domain instead of a fibrinogen-like domain. MBL plays a role in innate immunity by acting as an opsonin and activating complement in association with MBL-associated serine protease (MASP) via the lectin pathway. Investigations of two types of human serum ficolins, ficolin/P35 and Hakata antigen, revealed that they are associated with MASPs and sMAP, a truncated protein of MASP-2, and that they activate complement. These findings indicate that serum ficolins are structurally and functionally similar to MBL and have the capacity to activate the lectin pathway and thus have a role in innate immunity. PMID:11414366

  2. Role of early lectin pathway activation in the complement-mediated killing of Trypanosoma cruzi.

    PubMed

    Cestari, Igor dos S; Krarup, Anders; Sim, Robert B; Inal, Jameel M; Ramirez, Marcel I

    2009-12-01

    The complement system is the first line of defence against pathogen infection and can be activated by the classic, alternative and lectin pathways. Trypanosoma cruzi, the causative agent of Chagas disease, has to evade complement system killing and invade the host cells to progress in infection. T. cruzi infectious stages resist complement-mediated killing by expressing surface receptors, which dissociate or prevent C3 convertase formation. Here, we present the first evidence that T. cruzi activates the complement lectin pathway. We detected rapid binding of mannan-binding lectin, H-ficolin, and L-ficolin to the surface of T. cruzi, and found that serum depleted of these molecules failed to kill parasites. Furthermore, lectin pathway activation by T. cruzi required the MBL-associated serine protease 2 (MASP2) activity resulting in C2 factor cleavage. In addition, we demonstrate that the infectious stage of T. cruzi inhibits the lectin pathway activation and complement killing expressing the complement C2 receptor inhibitor trispanning (CRIT) protein. Transgenic parasites overexpressing CRIT were highly resistant to complement-mediated killing. CRIT-derived peptides inhibited both C2 binding to the surface of T. cruzi and parasite killing. Biochemical studies revealed that the CRIT extracellular domain 1 inhibits MASP2 cleavage of C2 factor and thereby impairs C3 convertase formation. Our findings establish that the complement lectin pathway recognizes T. cruzi and provide molecular insights into how the infectious stage inhibits this activation to resist complement system killing. PMID:19783051

  3. C-type lectins and galectins mediate innate and adaptive immune functions: their roles in the complement activation pathway

    Microsoft Academic Search

    Gerardo R. Vasta; Michael Quesenberry; Hafiz Ahmed; Nuala O'Leary

    1999-01-01

    In recent years, a `new' pathway for complement activation mediated by the mannose-binding lectin (MBL) has been described as a key mechanism for the mammalian acute phase response to infection. This complement activation pathway is initiated by a non-self recognition step: the binding of a humoral C-type lectin [mannose-binding lectin (MBL)] to microbial surfaces bearing `foreign' carbohydrate determinants. The recognition

  4. Involvement of lectin pathway activation in the complement killing of Giardia intestinalis.

    PubMed

    Evans-Osses, Ingrid; Ansa-Addo, Ephraim A; Inal, Jameel M; Ramirez, Marcel I

    2010-05-01

    Giardia intestinalis (syn. G. lamblia, G. duodenalis) is a flagellated unicellular eukaryotic microorganism that commonly causes diarrheal disease throughout the world. In humans, the clinical effects of Giardia infection range from the asymptomatic carrier state to a severe malabsorption syndrome possibly due to different virulence of the Giardia strain, the number of cysts ingested, the age of the host, and the state of the host immune system at the time of infection. The question about how G. intestinalis is controlled by the organism remains unanswered. Here, we investigated the role of the complement system and in particular, the lectin pathway during Giardia infections. We present the first evidence that G. intestinalis activate the complement lectin pathway and in doing so participate in eradication of the parasite. We detected rapid binding of mannan-binding lectin, H-ficolin and L-ficolin to the surface of G. intestinalis trophozoites and normal human serum depleted of these molecules failed to kill the parasites. Our finding provides insight into the role of lectin pathway in the control of G. intestinalis and about the nature of surface components of parasite. PMID:20382117

  5. No Strong Relationship Between Components of the Lectin Pathway of Complement and Susceptibility to Pulmonary Tuberculosis.

    PubMed

    Chalmers, James D; Matsushita, Misao; Kilpatrick, David C; Hill, Adam T

    2015-08-01

    Mycobacterium tuberculosis (TB) may utilise the lectin complement pathway to facilitate entry into its niche within macrophages. Previous studies examining mannose-binding lectin (MBL) in patients with TB have been limited by failure to correlate genotype/phenotype relationships. This study investigated serum levels and genotypes of MBL, Ficolin-2, Ficolin-3 and MASP-2 in 168 patients with pulmonary tuberculosis and 168 age/sex-matched controls. Low serum levels of MBL and Ficolin-2 were defined using cut-offs previously identified in the literature. Median MBL serum levels were higher in TB patients than controls-1400 ng/ml (IQR 435-2520) vs 1030 ng/ml (350-2050), p?=?0.02-but this was not mirrored by a difference in MBL haplotype frequencies (MBL deficient haplotypes were observed in 11.9 % of TB patients and 11.3 % of controls). Severe Ficolin-2 deficiency (<1200 ng/ml) was more frequent in TB than controls (7.1 vs 3.0 %, odds ratio 2.51 95 % CI 0.86-7.28, p?=?0.1) but the difference was not statistically significant. No relationship between Ficolin-2, Ficolin-3 or MASP-2 genotypes or serum levels and TB were observed. No strong relationship between the lectin complement pathway and pulmonary tuberculosis was observed. Previous data linking high MBL serum levels with TB were likely due to an acute phase response rather than a true effect on disease susceptibility. PMID:25761428

  6. Structural Basis for the Function of Complement Component C4 within the Classical and Lectin Pathways of Complement.

    PubMed

    Mortensen, Sofia; Kidmose, Rune T; Petersen, Steen V; Szilágyi, Ágnes; Prohászka, Zoltan; Andersen, Gregers R

    2015-06-01

    Complement component C4 is a central protein in the classical and lectin pathways within the complement system. During activation of complement, its major fragment C4b becomes covalently attached to the surface of pathogens and altered self-tissue, where it acts as an opsonin marking the surface for removal. Moreover, C4b provides a platform for assembly of the proteolytically active convertases that mediate downstream complement activation by cleavage of C3 and C5. In this article, we present the crystal and solution structures of the 195-kDa C4b. Our results provide the molecular details of the rearrangement accompanying C4 cleavage and suggest intramolecular flexibility of C4b. The conformations of C4b and its paralogue C3b are shown to be remarkably conserved, suggesting that the convertases from the classical and alternative pathways are likely to share their overall architecture and mode of substrate recognition. We propose an overall molecular model for the classical pathway C5 convertase in complex with C5, suggesting that C3b increases the affinity for the substrate by inducing conformational changes in C4b rather than a direct interaction with C5. C4b-specific features revealed by our structural studies are probably involved in the assembly of the classical pathway C3/C5 convertases and C4b binding to regulators. PMID:25911760

  7. Depressed activation of the lectin pathway of complement in hereditary angioedema

    PubMed Central

    Varga, L; Széplaki, G; Laki, J; Kocsis, A; Kristóf, K; Gál, P; Bajtay, Z; Wieslander, J; Daha, M R; Garred, P; Madsen, H O; Füst, G; Farkas, H

    2008-01-01

    The possibility of simultaneous measurement of the classical pathway (CP), mannan-binding lectin (MBL)–lectin pathway (LP) and alternative pathway (AP) of complement activation by the recently developed Wielisa method allowed us to investigate the in vivo significance of the C1-inhibitor (C1INH) in three complement activation pathways. Functional activity of the CP, LP and AP were measured in the sera of 68 adult patients with hereditary angioedema (HAE) and 64 healthy controls. In addition, the level of C1q, MBL, MBL-associated serine protease-2 (MASP-2), C4-, C3- and C1INH was measured by standard laboratory methods. MBL-2 genotypes were determined by polymerase chain reaction. Besides the complement alterations (low CP and C1INH activity, low C4-, C1INH concentrations), which characterize HAE, the level of MASP-2 was also lower (P = 0·0001) in patients compared with controls. Depressed LP activity was found in patients compared with controls (P = 0·0008) in homozygous carriers of the normal MBL genotype (A/A), but not in carriers of variant genotypes (A/O, O/O). Activity of CP correlated with LP in patients (Spearman's r = 0·64; P < 0·0001), but no significant correlation was found in the control group and no correlation with AP was observed. In contrast, the activity of CP and AP correlated (Spearman's r = 0·47; P < 0·0001) in healthy controls, but there was no significant correlation in the HAE patients. We conclude that the activation of LP might also occur in subjects with C1INH deficiency, which is reflected by the low MASP-2 and C4 levels. PMID:18460017

  8. The Emerging Role of Complement Lectin Pathway in Trypanosomatids: Molecular Bases in Activation, Genetic Deficiencies, Susceptibility to Infection, and Complement System-Based Therapeutics

    PubMed Central

    Evans-Osses, Ingrid; de Messias-Reason, Iara; Ramirez, Marcel I.

    2013-01-01

    The innate immune system is evolutionary and ancient and is the pivotal line of the host defense system to protect against invading pathogens and abnormal self-derived components. Cellular and molecular components are involved in recognition and effector mechanisms for a successful innate immune response. The complement lectin pathway (CLP) was discovered in 1990. These new components at the complement world are very efficient. Mannan-binding lectin (MBL) and ficolin not only recognize many molecular patterns of pathogens rapidly to activate complement but also display several strategies to evade innate immunity. Many studies have shown a relation between the deficit of complement factors and susceptibility to infection. The recently discovered CLP was shown to be important in host defense against protozoan microbes. Although the recognition of pathogen-associated molecular patterns by MBL and Ficolins reveal efficient complement activations, an increase in deficiency of complement factors and diversity of parasite strategies of immune evasion demonstrate the unsuccessful effort to control the infection. In the present paper, we will discuss basic aspects of complement activation, the structure of the lectin pathway components, genetic deficiency of complement factors, and new therapeutic opportunities to target the complement system to control infection. PMID:23533355

  9. The emerging role of complement lectin pathway in trypanosomatids: molecular bases in activation, genetic deficiencies, susceptibility to infection, and complement system-based therapeutics.

    PubMed

    Evans-Osses, Ingrid; de Messias-Reason, Iara; Ramirez, Marcel I

    2013-01-01

    The innate immune system is evolutionary and ancient and is the pivotal line of the host defense system to protect against invading pathogens and abnormal self-derived components. Cellular and molecular components are involved in recognition and effector mechanisms for a successful innate immune response. The complement lectin pathway (CLP) was discovered in 1990. These new components at the complement world are very efficient. Mannan-binding lectin (MBL) and ficolin not only recognize many molecular patterns of pathogens rapidly to activate complement but also display several strategies to evade innate immunity. Many studies have shown a relation between the deficit of complement factors and susceptibility to infection. The recently discovered CLP was shown to be important in host defense against protozoan microbes. Although the recognition of pathogen-associated molecular patterns by MBL and Ficolins reveal efficient complement activations, an increase in deficiency of complement factors and diversity of parasite strategies of immune evasion demonstrate the unsuccessful effort to control the infection. In the present paper, we will discuss basic aspects of complement activation, the structure of the lectin pathway components, genetic deficiency of complement factors, and new therapeutic opportunities to target the complement system to control infection. PMID:23533355

  10. Trypanosoma cruzi calreticulin inhibits the complement lectin pathway activation by direct interaction with L-Ficolin.

    PubMed

    Sosoniuk, Eduardo; Vallejos, Gerardo; Kenawy, Hany; Gaboriaud, Christine; Thielens, Nicole; Fujita, Teizo; Schwaeble, Wilhelm; Ferreira, Arturo; Valck, Carolina

    2014-07-01

    Trypanosoma cruzi, the agent of Chagas' disease, the sixth neglected tropical disease worldwide, infects 10-12 million people in Latin America. Differently from T. cruzi epimastigotes, trypomastigotes are complement-resistant and infective. CRPs, T-DAF, sialic acid and lipases explain at least part of this resistance. In vitro, T. cruzi calreticulin (TcCRT), a chaperone molecule that translocates from the ER to the parasite surface: (a) Inhibits the human classical complement activation, by interacting with C1, (b) As a consequence, an increase in infectivity is evident and, (c) It inhibits angiogenesis and tumor growth. We report here that TcCRT also binds to the L-Ficolin collagenous portion, thus inhibiting approximately between 35 and 64% of the human complement lectin pathway activation, initiated by L-Ficolin, a property not shared by H-Ficolin. While L-Ficolin binds to 60% of trypomastigotes and to 24% of epimastigotes, 50% of the former and 4% of the latter display TcCRT on their surfaces. Altogether, these data indicate that TcCRT is a parasite inhibitory receptor for Ficolins. The resulting evasive activities, together with the TcCRT capacity to inhibit C1, with a concomitant increase in infectivity, may represent T. cruzi strategies to inhibit important arms of the innate immune response. PMID:24769495

  11. Mutations in lectin complement pathway genes COLEC11 and MASP1 cause 3MC syndrome.

    PubMed

    Rooryck, Caroline; Diaz-Font, Anna; Osborn, Daniel P S; Chabchoub, Elyes; Hernandez-Hernandez, Victor; Shamseldin, Hanan; Kenny, Joanna; Waters, Aoife; Jenkins, Dagan; Kaissi, Ali Al; Leal, Gabriela F; Dallapiccola, Bruno; Carnevale, Franco; Bitner-Glindzicz, Maria; Lees, Melissa; Hennekam, Raoul; Stanier, Philip; Burns, Alan J; Peeters, Hilde; Alkuraya, Fowzan S; Beales, Philip L

    2011-03-01

    3MC syndrome has been proposed as a unifying term encompassing the overlapping Carnevale, Mingarelli, Malpuech and Michels syndromes. These rare autosomal recessive disorders exhibit a spectrum of developmental features, including characteristic facial dysmorphism, cleft lip and/or palate, craniosynostosis, learning disability and genital, limb and vesicorenal anomalies. Here we studied 11 families with 3MC syndrome and identified two mutated genes, COLEC11 and MASP1, both of which encode proteins in the lectin complement pathway (collectin kidney 1 (CL-K1) and MASP-1 and MASP-3, respectively). CL-K1 is highly expressed in embryonic murine craniofacial cartilage, heart, bronchi, kidney and vertebral bodies. Zebrafish morphants for either gene develop pigmentary defects and severe craniofacial abnormalities. Finally, we show that CL-K1 serves as a guidance cue for neural crest cell migration. Together, these findings demonstrate a role for complement pathway factors in fundamental developmental processes and in the etiology of 3MC syndrome. PMID:21258343

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

    PubMed Central

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

    2013-01-01

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

  13. Mannan-binding lectin activates C3 and the alternative complement pathway without involvement of C2

    PubMed Central

    Selander, Barbro; Mĺrtensson, Ulla; Weintraub, Andrej; Holmström, Eva; Matsushita, Misao; Thiel, Steffen; Jensenius, Jens C.; Truedsson, Lennart; Sjöholm, Anders G.

    2006-01-01

    Lectin pathway activation of C3 is known to involve target recognition by mannan-binding lectin (MBL) or ficolins and generation of classical pathway C3 convertase via cleavage of C4 and C2 by MBL-associated serine protease 2 (MASP-2). We investigated C3 activation in C2-deficient human sera and in sera with other defined defects of complement to assess other mechanisms through which MBL might recruit complement. The capacity of serum to support C3 deposition was examined by ELISA using microtiter plates coated with O antigen–specific oligosaccharides derived from Salmonella typhimurium, S. thompson, and S. enteritidis corresponding to serogroups B, C, and D (BO, CO, and DO). MBL bound to CO, but not to BO and DO, and efficiently supported C3 deposition in the absence of C2, C4, or MASP-2. The existence of an MBL-dependent C2 bypass mechanism for alternative pathway–mediated C3 activation was clearly demonstrated using CO, solid-phase mannan, and E. coli LPS. MASP-1 might contribute, but was not required for C3 deposition in the model used. Independent of MBL, specific antibodies to CO supported C3 deposition through classical and alternative pathways. MBL-dependent C2 bypass activation could be particularly important in various inherited and acquired complement deficiency states. PMID:16670774

  14. Human L-ficolin, a recognition molecule of the lectin activation pathway of complement, activates complement by binding to pneumolysin, the major toxin of Streptococcus pneumoniae.

    PubMed

    Ali, Youssif M; Kenawy, Hany I; Muhammad, Adnan; Sim, Robert B; Andrew, Peter W; Schwaeble, Wilhelm J

    2013-01-01

    The complement system is an essential component of the immune response, providing a critical line of defense against different pathogens including S. pneumoniae. Complement is activated via three distinct pathways: the classical (CP), the alternative (AP) and the lectin pathway (LP). The role of Pneumolysin (PLY), a bacterial toxin released by S. pneumoniae, in triggering complement activation has been studied in vitro. Our results demonstrate that in both human and mouse sera complement was activated via the CP, initiated by direct binding of even non-specific IgM and IgG3 to PLY. Absence of CP activity in C1q(-/-) mouse serum completely abolished any C3 deposition. However, C1q depleted human serum strongly opsonized PLY through abundant deposition of C3 activation products, indicating that the LP may have a vital role in activating the human complement system on PLY. We identified that human L-ficolin is the critical LP recognition molecule that drives LP activation on PLY, while all of the murine LP recognition components fail to bind and activate complement on PLY. This work elucidates the detailed interactions between PLY and complement and shows for the first time a specific role of the LP in PLY-mediated complement activation in human serum. PMID:24349316

  15. Revised mechanism of complement lectin-pathway activation revealing the role of serine protease MASP-1 as the exclusive activator of MASP-2

    PubMed Central

    Héja, Dávid; Kocsis, Andrea; Dobó, József; Szilágyi, Katalin; Szász, Róbert; Závodszky, Péter; Pál, Gábor; Gál, Péter

    2012-01-01

    The lectin pathway of complement activation is an important component of the innate immune defense. The initiation complexes of the lectin pathway consist of a recognition molecule and associated serine proteases. Until now the autoactivating mannose-binding lectin-associated serine protease (MASP)-2 has been considered the autonomous initiator of the proteolytic cascade. The role of the much more abundant MASP-1 protease was controversial. Using unique, monospecific inhibitors against MASP-1 and MASP-2, we corrected the mechanism of lectin-pathway activation. In normal human serum, MASP-2 activation strictly depends on MASP-1. MASP-1 activates MASP-2 and, moreover, inhibition of MASP-1 prevents autoactivation of MASP-2. Furthermore we demonstrated that MASP-1 produces 60% of C2a responsible for C3 convertase formation. PMID:22691502

  16. Inhibition of the classical and lectin pathway of the complement system by recombinant LAIR-2.

    PubMed

    Olde Nordkamp, Marloes J M; Boross, Peter; Yildiz, Cafer; Jansen, J H Marco; Leusen, Jeanette H W; Wouters, Diana; Urbanus, Rolf T; Hack, C Erik; Meyaard, Linde

    2014-01-01

    Activation of complement may cause severe tissue damage in antibody-mediated allograft rejection and other antibody-mediated clinical conditions; therefore, novel potent complement inhibitors are needed. Previously, we described binding of the inhibitory receptor LAIR-1 and its soluble family member LAIR-2 to collagen. Here, we investigated binding of LAIR-1 and LAIR-2 to the complement proteins C1q and MBL, which both have collagen-like domains, and evaluated the effect of this binding on complement function. We demonstrate specific binding of recombinant LAIR proteins to both C1q and MBL. Surface plasmon resonance experiments showed that LAIR-2-Fc protein bound C1q and MBL with the highest affinity compared to LAIR-2-HIS. We, therefore, hypothesized that LAIR-2-Fc is a potent complement inhibitor. Indeed, LAIR-2-Fc inhibited C4 fixation to IgG or mannan, reduced activation of C4 by aggregated IgG in plasma and inhibited iC3b deposition on cells. Finally, LAIR-2-Fc inhibited complement-mediated lysis of cells sensitized with anti-HLA antibodies in an ex vivo model for antibody-mediated transplant rejection. Thus, LAIR-2-Fc is an effective novel complement inhibitor for the treatment and prevention of antibody-mediated allograft rejection and antibody-mediated clinical conditions. PMID:24192271

  17. New perspectives on mannan-binding lectin-mediated complement activation

    Microsoft Academic Search

    Sřren E. Degn; Steffen Thiel; Jens C. Jensenius

    2007-01-01

    The complement system is an important part of the innate immune system, mediating several major effector functions and modulating adaptive immune responses. Three complement activation pathways exist: the classical pathway (CP), the alternative pathway (AP), and the lectin pathway (LP). The LP is the most recently discovered, and least characterized. The CP and the LP are generally viewed as working

  18. The extracellular adherence protein from Staphylococcus aureus inhibits the classical and lectin pathways of complement by blocking formation of the C3 proconvertase.

    PubMed

    Woehl, Jordan L; Stapels, Daphne A C; Garcia, Brandon L; Ramyar, Kasra X; Keightley, Andrew; Ruyken, Maartje; Syriga, Maria; Sfyroera, Georgia; Weber, Alexander B; Zolkiewski, Michal; Ricklin, Daniel; Lambris, John D; Rooijakkers, Suzan H M; Geisbrecht, Brian V

    2014-12-15

    The pathogenic bacterium Staphylococcus aureus actively evades many aspects of human innate immunity by expressing a series of small inhibitory proteins. A number of these proteins inhibit the complement system, which labels bacteria for phagocytosis and generates inflammatory chemoattractants. Although the majority of staphylococcal complement inhibitors act on the alternative pathway to block the amplification loop, only a few proteins act on the initial recognition cascades that constitute the classical pathway (CP) and lectin pathway (LP). We screened a collection of recombinant, secreted staphylococcal proteins to determine whether S. aureus produces other molecules that inhibit the CP and/or LP. Using this approach, we identified the extracellular adherence protein (Eap) as a potent, specific inhibitor of both the CP and LP. We found that Eap blocked CP/LP-dependent activation of C3, but not C4, and that Eap likewise inhibited deposition of C3b on the surface of S. aureus cells. In turn, this significantly diminished the extent of S. aureus opsonophagocytosis and killing by neutrophils. This combination of functional properties suggested that Eap acts specifically at the level of the CP/LP C3 convertase (C4b2a). Indeed, we demonstrated a direct, nanomolar-affinity interaction of Eap with C4b. Eap binding to C4b inhibited binding of both full-length C2 and its C2b fragment, which indicated that Eap disrupts formation of the CP/LP C3 proconvertase (C4b2). As a whole, our results demonstrate that S. aureus inhibits two initiation routes of complement by expression of the Eap protein, and thereby define a novel mechanism of immune evasion. PMID:25381436

  19. A novel peptide inhibitor of classical and lectin complement activation including ABO incompatibility

    PubMed Central

    Mauriello, Clifford T.; Pallera, Haree K.; Sharp, Julia A.; Woltmann, Jon L.; Qian, Shizhi; Hair, Pamela S.; van der Pol, Pieter; van Kooten, Cees; Thielens, Nicole M.; Lattanzio, Frank A.; Cunnion, Kenji M.; Krishna, Neel K.

    2012-01-01

    Previous experiments from our laboratories have identified peptides derived from the human astrovirus coat protein (CP) that bind C1q and mannose binding lectin (MBL) inhibiting activation of the classical and lectin pathways of complement, respectively. The purpose of this study was to evaluate the function of these coat protein peptides (CPPs) in an in vitro model of complement-mediated disease (ABO incompatibility), preliminarily assess their in vivo complement suppression profile and develop more highly potent derivatives of these molecules. E23A, a 30 amino acid CPP derivative previously demonstrated to inhibit classical pathway activation was able to dose-dependently inhibit lysis of AB erythrocytes treated with mismatched human O serum. Additionally, when injected into rats, E23A inhibited the animals’ serum from lysing antibody-sensitized erythrocytes, providing preliminary in vivo functional evidence that this CPP can cross the species barrier to inhibit serum complement activity in rodents. A rational drug design approach was implemented to identify more potent CPP derivatives, resulting in the identification and characterization of a 15 residue peptide (Polar Assortant (PA)), which demonstrated both superior inhibition of classical complement pathway activation and robust binding to C1q collagen-like tails. PA also inhibited ABO incompatibility in vitro and demonstrated in vivo complement suppression up to 24 hours post-injection. CPP’s ability to inhibit ABO incompatibility in vitro, proof of concept in vivo inhibitory activity in rats and the development of the highly potent PA derivative set the stage for preclinical testing of this molecule in small animal models of complement-mediated disease. PMID:22906481

  20. Secondary cell wall polymers of Enterococcus faecalis are critical for resistance to complement activation via mannose-binding lectin.

    PubMed

    Geiss-Liebisch, Stefan; Rooijakkers, Suzan H M; Beczala, Agnieszka; Sanchez-Carballo, Patricia; Kruszynska, Karolina; Repp, Christian; Sakinc, Tuerkan; Vinogradov, Evgeny; Holst, Otto; Huebner, Johannes; Theilacker, Christian

    2012-11-01

    The complement system is part of our first line of defense against invading pathogens. The strategies used by Enterococcus faecalis to evade recognition by human complement are incompletely understood. In this study, we identified an insertional mutant of the wall teichoic acid (WTA) synthesis gene tagB in E. faecalis V583 that exhibited an increased susceptibility to complement-mediated killing by neutrophils. Further analysis revealed that increased killing of the mutant was due to a higher rate of phagocytosis by neutrophils, which correlated with higher C3b deposition on the bacterial surface. Our studies indicated that complement activation via the lectin pathway was much stronger on the tagB mutant compared with wild type. In concordance, we found an increased binding of the key lectin pathway components mannose-binding lectin and mannose-binding lectin-associated serine protease-2 (MASP-2) on the mutant. To understand the mechanism of lectin pathway inhibition by E. faecalis, we purified and characterized cell wall carbohydrates of E. faecalis wild type and V583?tagB. NMR analysis revealed that the mutant strain lacked two WTAs with a repeating unit of ?6)[?-l-Rhap-(1?3)]?-D-GalpNAc-(1?5)-Rbo-1-P and ?6) ?-D-Glcp-(1?3) [?-D-Glcp-(1?4)]-?-D-GalpNAc-(1?5)-Rbo-1-P?, respectively (Rbo, ribitol). In addition, compositional changes in the enterococcal rhamnopolysaccharide were noticed. Our study indicates that in E. faecalis, modification of peptidoglycan by secondary cell wall polymers is critical to evade recognition by the complement system. PMID:22908219

  1. Alternative complement pathway of channel catfish Ictalurus punctatus: molecular characterization and expression analysis of factors Bf/C2 and Df

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The complement system important in both innate and adaptive host defense against microbial infection in vertebrates. It contains three pathways: the classical, alternative, and lectin pathways. Complement component factors B and D are two crucial proteases in the alternative pathway. In this study,...

  2. 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

  3. A novel IgM–H-Ficolin complement pathway to attack allogenic cancer cells in vitro

    PubMed Central

    Lei, Xiaoying; Liu, Chaoxu; Azadzoi, Kazem; Li, Cuiling; Lu, Fan; Xiang, An; Sun, Jianbin; Guo, Yanhai; Zhao, Qingchuan; Yan, Zhen; Yang, Jinghua

    2015-01-01

    The pentameric serum IgMs are critical to immune defense and surveillance through cytotoxicity against microbes and nascent cancer cells. Ficolins, a group of oligomeric lectins with an overall structure similar to C1q and mannose-binding lectin (MBL) participate in microbe infection and apoptotic cell clearance by activating the complement lectin pathway or a primitive opsonophagocytosis. It remains unknown whether serum IgMs interplay with ficolins in cancer immunosurveillance. Here we report a natural cancer killing of different types of cancer cells by sera from a healthy human population mediated by a novel IgM–H-ficolin complement activation pathway. We demonstrate for the first time that H-ficolin bound to a subset of IgMs in positive human sera and IgM–H-ficolin deposited on cancer cells to activate complement attack in cancer cells. Our data suggest that the IgM–H-ficolin -mediated complement activation pathway may be another defensive strategy for human cancer immunosurveillance. PMID:25592840

  4. A second serine protease associated with mannan-binding lectin that activates complement

    Microsoft Academic Search

    Steffen Thiel; Thomas Vorup-Jensen; Cordula M. Stover; Wilhelm Schwaeble; Steen B. Laursen; Knud Poulsen; Anthony C. Willis; Paul Eggleton; Sřren Hansen; Uffe Holmskov; Kenneth B. M. Reid; Jens C. Jensenius

    1997-01-01

    The complement system comprises a complex array of enzymes and non-enzymatic proteins that is essential for the operation of the innate as well as the adaptive immune defence1. The complement system can be activated in three ways: by the classical pathway which is initiated by antibody-antigen complexes, by the alternative pathway initiated by certain structures on microbial surfaces, and by

  5. Comprehensive and comparative transcription analyses of the complement pathway in rainbow trout.

    PubMed

    Köbis, Judith M; Rebl, Alexander; Kühn, Carsten; Korytá?, Tomáš; Köllner, Bernd; Goldammer, Tom

    2015-01-01

    The complement system is one of the most ancient and most essential innate immune cascades throughout the animal kingdom. Survival of aquatic animals, such as rainbow trout, depends on this early inducible, efficient immune cascade. Despite increasing research on genes coding for complement components in bony fish, some complement-related genes are still unknown in salmonid fish. In the present study, we characterize the genes encoding complement factor D (CFD), CD93 molecule (CD93), and C-type lectin domain family 4, member M (CLEC4M) from rainbow trout (Oncorhynchus mykiss). Subsequently, we performed comprehensive and comparative expression analyses of 36 complement genes including CFD, CD93, and CLEC4M and further putative complement-associated genes to obtain general information about the functional gene interaction within the complement pathway in fish. These quantification analyses were conducted in liver, spleen and gills of healthy fish of two rainbow trout strains, selected for survival (strain BORN) and growth (Import strain), respectively. The present expression study clearly confirms for rainbow trout that liver represents the primary site of complement expression. Spleen and gills also express most complement genes, although the mean transcript levels were generally lower than in liver. The transcription data suggest a contribution of spleen and gills to complement activity. The comparison of the two rainbow trout strains revealed a generally similar complement gene expression. However, a significantly lower expression of numerous genes especially in spleen seems characteristic for the BORN strain. This suggests a strain-specific complement pathway regulation under the selected rearing conditions. PMID:25449374

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

    PubMed Central

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

    2012-01-01

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

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

    PubMed

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

    2015-07-01

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

  8. Mannose-Binding Lectin Binds to a Range of Clinically Relevant Microorganisms and Promotes Complement Deposition

    Microsoft Academic Search

    OLAF NETH; DOMINIC L. JACK; ALISTER W. DODDS; HELEN HOLZEL; NIGEL J. KLEIN; MALCOLM W. TURNER

    2000-01-01

    Mannose-binding lectin (MBL) is a collagenous serum lectin believed to be of importance in innate immunity. Genetically determined low levels of the protein are known to predispose to infections. In this study the binding of purified MBL to pathogens isolated from immunocompromised children was investigated by flow cytometry. Diverse Candida species, Aspergillus fumigatus, Staphylococcus aureus, and beta-hemolytic group A streptococci

  9. Activated complement classical pathway in a murine model of oxygen-induced retinopathy

    PubMed Central

    Tao, Xue-Ying; Zheng, Shi-Jie; Lei, Bo

    2015-01-01

    AIM To investigate whether the complement system is involved in a murine model of oxygen-induced retinopathy (OIR). METHODS Forty C57BL/6J newborn mice were divided randomly into OIR group and control group. OIR was induced by exposing mice to 75%±2% oxygen from postnatal 7d (P7) to P12 and then recovered in room air. For the control group, the litters were raised in room air. At the postnatal 17d (P17), gene expressions of the complement components of the classical pathway (CP), the mannose-binding lectin (MBL) pathway and the alternative pathway (AP) in the retina were determined by quantitative real-time polymerase chain reaction (RT-PCR). Retinal protein expressions of the key components in the CP were examined by Western blotting. RESULTS Whole mounted retina in the OIR mice showed area of central hypoperfusion in both superficial and deep layers and neovascular tufts in the periphery. The expressions of C1qb and C4b genes in the OIR retina were significantly higher than those of the controls. The expression of retinal complement factor B (CFB) gene in OIR mice was significantly lower than those of the controls. However, the expressions of C3 and complement factor H (CFH) genes were higher. The protein synthesis of the key components involved in the CP (C1q, C4 and C3) were also significantly higher in OIR mouse retina. Although MBL-associated serine protease 1 (MASP1) and MASP2 were detected in both the OIR and the control groups, the expressions were weak and the difference between the two groups was not significant. CONCLUSION Our data suggest that the complement system CP is activated during the pathogenesis of murine model of OIR. PMID:25709901

  10. Peptide Inhibitor of Complement C1, a Novel Suppressor of Classical Pathway Activation: Mechanistic Studies and Clinical Potential

    PubMed Central

    Sharp, Julia A.; Whitley, Pamela H.; Cunnion, Kenji M.; Krishna, Neel K.

    2014-01-01

    The classical pathway of complement plays multiple physiological roles including modulating immunological effectors initiated by adaptive immune responses and an essential homeostatic role in the clearance of damaged self-antigens. However, dysregulated classical pathway activation is associated with antibody-initiated, inflammatory diseases processes like cold agglutinin disease, acute intravascular hemolytic transfusion reaction (AIHTR), and acute/hyperacute transplantation rejection. To date, only one putative classical pathway inhibitor, C1 esterase inhibitor (C1-INH), is currently commercially available and its only approved indication is for replacement treatment in hereditary angioedema, which is predominantly a kinin pathway disease. Given the variety of disease conditions in which the classical pathway is implicated, development of therapeutics that specifically inhibits complement initiation represents a major unmet medical need. Our laboratory has identified a peptide that specifically inhibits the classical and lectin pathways of complement. In vitro studies have demonstrated that these peptide inhibitors of complement C1 (PIC1) bind to the collagen-like region of the initiator molecule of the classical pathway, C1q. PIC1 binding to C1q blocks activation of the associated serine proteases (C1s–C1r–C1r–C1s) and subsequent downstream complement activation. Rational design optimization of PIC1 has resulted in the generation of a highly potent derivative of 15 amino acids. PIC1 inhibits classical pathway mediated complement activation in ABO incompatibility in vitro and inhibiting classical pathway activation in vivo in rats. This review will focus on the pre-clinical development of PIC1 and discuss its potential as a therapeutic in antibody-mediated classical pathway disease, specifically AIHTR. PMID:25202312

  11. Activation of complement pathways in xenotransplantation: an in vitro study.

    PubMed

    Walpen, Alexander J; Mohacsi, Paul; Frey, Caroline; Roos, Anja; Daha, Mohamed R; Rieben, Robert

    2002-05-01

    Pig-to-human xenotransplantation faces the problem of hyperacute graft rejection due to the presence of human naturally occurring antibodies against the disaccharide Galalpha1-3Gal (anti-Gal antibodies) expressed on pig endothelium. Antibody-mediated complement activation is usually referred to as classical pathway activation. In this study we examined if the alternative complement pathway is also directly activated through anti-Gal antibodies or if the classical pathway is indispensable. We therefore developed a hemolysis test with rabbit erythrocytes (E), which have an activating surface for the alternative complement pathway and express abundant amounts of Galalpha1-3Gal, and used this assay in addition to the standard complement tests CH50 and AP50. In this rabbit E CH50 (RECH50) assay we were able to study activation of both major complement pathways simultaneously. FACS analysis was used to trace complement and antibody deposition on rabbit E. Anti-Gal depletion of human serum by immunoabsorption revealed a 65% reduction of rabbit E hemolysis in the RECH50 test (value before absorption: 28 +/- 5.8, after absorption: 9.9 +/- 2.8, P<0.001), but only a 35% reduction of lysis in the AP50 test (AP50 before 11.3 +/- 2.1, after 7.4 +/- 2.0, P<0.002). Repletion with purified anti-Gal fully restored hemolysis in both assays. Serum depleted of Clq showed a reduced lysis of rabbit E as compared to normal human serum; this effect increased with higher serum dilutions. The reciprocal picture, i.e. less effect on hemolysis with increasing dilution, was seen with factor D depleted serum. Comparison of the RECH50 values with the AP50 values revealed an 8.4-fold increase of lysis in the RECH50 test, in which both complement pathways are running. By FACS analysis, complement deposition on rabbit E was determined and components of the classical pathway were found, especially in sera where the alternative pathway was disrupted. We conclude that in our model anti-Gal induce lysis via both classical and alternative complement pathways, but that the alternative pathway activation is of minor importance. In addition, we saw that with higher serum dilutions, the classical pathway (i.e. anti-Gal-mediated lysis) takes a predominant role in lysing the rabbit E. As anti-Gal-mediated activation of the alternative complement cascade seems of minor importance based on our results, and as there are only few surfaces in transplanted organs that would favor the alternative pathway to be executed, the specific inhibition of early steps of the classical pathway appears as a realistic strategy in pig-to-primate xenotransplantation that-to the benefit of the patient-leaves the mainly anti-bacterial defense by the alternative pathway intact. PMID:12180841

  12. Cleavage of kininogen and subsequent bradykinin release by the complement component: mannose-binding lectin-associated serine protease (MASP)-1.

    PubMed

    Dobó, József; Major, Balázs; Kékesi, Katalin A; Szabó, István; Megyeri, Márton; Hajela, Krishnan; Juhász, Gábor; Závodszky, Péter; Gál, Péter

    2011-01-01

    Bradykinin (BK), generated from high-molecular-weight kininogen (HK) is the major mediator of swelling attacks in hereditary angioedema (HAE), a disease associated with C1-inhibitor deficiency. Plasma kallikrein, activated by factor XIIa, is responsible for most of HK cleavage. However other proteases, which activate during episodes of angioedema, might also contribute to BK production. The lectin pathway of the complement system activates after infection and oxidative stress on endothelial cells generating active serine proteases: MASP-1 and MASP-2. Our aim was to study whether activated MASPs are able to digest HK to release BK. Initially we were trying to find potential new substrates of MASP-1 in human plasma by differential gel electrophoresis, and we identified kininogen cleavage products by this proteomic approach. As a control, MASP-2 was included in the study in addition to MASP-1 and kallikrein. The proteolytic cleavage of HK by MASPs was followed by SDS-PAGE, and BK release was detected by HPLC. We showed that MASP-1 was able to cleave HK resulting in BK production. MASP-2 could also cleave HK but could not release BK. The cleavage pattern of MASPs is similar but not strictly identical to that of kallikrein. The catalytic efficiency of HK cleavage by a recombinant version of MASP-1 and MASP-2 was about 4.0×10(2) and 2.7×10(2) M(-1) s(-1), respectively. C1-inhibitor, the major inhibitor of factor XIIa and kallikrein, also prevented the cleavage of HK by MASPs. In all, a new factor XII- and kallikrein-independent mechanism of bradykinin production by MASP-1 was demonstrated, which may contribute to the pro-inflammatory effect of the lectin pathway of complement and to the elevated bradykinin levels in HAE patients. PMID:21625439

  13. Cleavage of Kininogen and Subsequent Bradykinin Release by the Complement Component: Mannose-Binding Lectin-Associated Serine Protease (MASP)-1

    PubMed Central

    Dobó, József; Major, Balázs; Kékesi, Katalin A.; Szabó, István; Megyeri, Márton; Hajela, Krishnan; Juhász, Gábor; Závodszky, Péter; Gál, Péter

    2011-01-01

    Bradykinin (BK), generated from high-molecular-weight kininogen (HK) is the major mediator of swelling attacks in hereditary angioedema (HAE), a disease associated with C1-inhibitor deficiency. Plasma kallikrein, activated by factor XIIa, is responsible for most of HK cleavage. However other proteases, which activate during episodes of angioedema, might also contribute to BK production. The lectin pathway of the complement system activates after infection and oxidative stress on endothelial cells generating active serine proteases: MASP-1 and MASP-2. Our aim was to study whether activated MASPs are able to digest HK to release BK. Initially we were trying to find potential new substrates of MASP-1 in human plasma by differential gel electrophoresis, and we identified kininogen cleavage products by this proteomic approach. As a control, MASP-2 was included in the study in addition to MASP-1 and kallikrein. The proteolytic cleavage of HK by MASPs was followed by SDS-PAGE, and BK release was detected by HPLC. We showed that MASP-1 was able to cleave HK resulting in BK production. MASP-2 could also cleave HK but could not release BK. The cleavage pattern of MASPs is similar but not strictly identical to that of kallikrein. The catalytic efficiency of HK cleavage by a recombinant version of MASP-1 and MASP-2 was about 4.0×102 and 2.7×102 M?1s?1, respectively. C1-inhibitor, the major inhibitor of factor XIIa and kallikrein, also prevented the cleavage of HK by MASPs. In all, a new factor XII- and kallikrein-independent mechanism of bradykinin production by MASP-1 was demonstrated, which may contribute to the pro-inflammatory effect of the lectin pathway of complement and to the elevated bradykinin levels in HAE patients. PMID:21625439

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

    PubMed Central

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

    2014-01-01

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

  15. 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...

  16. Targeted inhibition of the complement alternative pathway with complement receptor 2 and factor H attenuates collagen antibody-induced arthritis in mice.

    PubMed

    Banda, Nirmal K; Levitt, Brandt; Glogowska, Magdalena J; Thurman, Joshua M; Takahashi, Kazue; Stahl, Gregory L; Tomlinson, Stephen; Arend, William P; Holers, V Michael

    2009-11-01

    The alternative pathway (AP) of complement is required for the induction of collagen Ab-induced arthritis (CAIA) in mice. The objective of this study was to examine the effect of a recombinant AP inhibitor containing complement receptor 2 and factor H (CR2-fH) on CAIA in mice. CR2 binds to tissue-fixed activation fragments of C3, and the linked fH is a potent local inhibitor of the AP. CAIA was induced in C57BL/6 mice by i.p. injections of 4 mAb to type II collagen (CII) on day 0 and LPS on day 3. PBS or CR2-fH (250 or 500 microg) were injected i.p. 15 min after the mAb to CII on day 0 and 15 min after LPS on day 3; the mice were sacrificed on day 10. The disease activity score (DAS) was decreased significantly (p < 0.001) in both groups receiving CR2-fH compared with the PBS. Histology scores for inflammation, pannus, bone damage, and cartilage damage decreased in parallel with the DAS. C3 deposition in the synovium and cartilage was significantly reduced (p < 0.0001) in the mice treated with CR2-fH. In vitro studies with immune complexes containing type II collagen and mAb to CII showed that CR2-fH specifically inhibited the AP with minimal effect on the classical pathway (CP) and no effect on the lectin pathway (LP). The relative potency of CR2-fH in vitro was superior to mAbs to factor B and C5. Thus, CR2-fH specifically targets and inhibits the AP of complement in vitro and is effective in CAIA in vivo. PMID:19828624

  17. Factor B of the alternative complement pathway regulates development of airway hyperresponsiveness and inflammation

    Microsoft Academic Search

    Christian Taube; Joshua M. Thurman; Katsuyuki Takeda; Anthony Joetham; Nobuaki Miyahara; Michael C. Carroll; Azzeddine Dakhama; Patricia C. Giclas; V. Michael Holers; Erwin W. Gelfand

    2006-01-01

    Exposure to inhaled allergens leads to increases in airway hyperresponsiveness (AHR) and inflammation, associated with increased levels of biologically active fragments derived from the complement C3 and C5 family of proteins. Further, complement activation during allergen challenge in sensitized animals is necessary for the development of AHR and airway inflammation. To define the complement pathway involved, we studied mice deficient

  18. The Alternative Pathway of Complement Activation May Be Involved in the Renal Damage of Human Anti-Glomerular Basement Membrane Disease

    PubMed Central

    Ma, Rui; Cui, Zhao; Hu, Shui-Yi; Jia, Xiao-Yu; Yang, Rui; Zheng, Xin; Ao, Jie; Liu, Gang; Liao, Yun-Hua; Zhao, Ming-Hui

    2014-01-01

    Linear deposition of IgG and complement 3 (C3) along glomerular basement membrane (GBM) is generally revealed in the kidneys of human anti-GBM disease. Our recent studies demonstrated the pathogenic role of complement activation in renal damage of this disease. However, the pathways of complement activation were still paradoxical. In this study, renal biopsy tissues from 10 patients with anti-GBM disease were used to investigate the pathways of complement activation by detecting the deposition of various complement components, including C1q, factor B, factor P (properdin), mannose-binding lectin (MBL), C3d, C4d and C5b-9, using immunohistochemistry and immunofluorescence. We found that C1q, factor B, properdin, C3d, C4d and C5b-9 were detected in all the glomeruli of our patients, along GBM with a linear and/or granular staining pattern. Furthermore, C1q, factor B and properdin co-localized well with C5b-9. The properdin also co-localized well with C3d. However, the deposition of MBL was diffusive in mesangium, GBM, Bowman's capsule and within crescents and was not co-localized with C5b-9 but partially co-localized with C4d. The intensity of factor B deposition (3.3 vs. 1.2, P<0.001) and C5b-9 deposition (3.2 vs. 1.6, P<0.001) was significantly stronger in the glomeruli with crescent formation, compared with the glomeruli without crescents. The complement system is overall activated via both the alternative pathway and classical pathway in the kidneys of human anti-GBM disease. The alternative pathway might play an important role in complement activation induced renal damage. PMID:24658070

  19. Functional assessment of rat complement pathway activities and quantification of soluble C5b-9 in an experimental model of renal ischemia/reperfusion injury.

    PubMed

    Kotimaa, J; van der Pol, P; Leijtens, S; Klar-Mohammad, N; Schilders, G; Daha, M R; Rutjes, H; van Kooten, C

    2014-10-01

    There is a growing interest in the monitoring of complement activation, not only in clinical settings but also in experimental models. However, for rodents only a limited number of tools are available to assess complement activity and activation. Here we describe three ELISAs for the measurement of rat classical (CP), MB-lectin (LP) and alternative (AP) pathway activities in serum and plasma. Moreover, we optimised a soluble C5b-9 (sC5b-9) ELISA for the detection of low level complement activation in rat. We determined the conditions for correct sample handling and showed that the assays had low inter- and intra-assay variation. We applied these assays to monitor complement activation in an experimental rat model of renal ischemia/reperfusion injury. We did not observe major complement consumption following reperfusion in CP or LP, and only minor AP consumption at 24h post reperfusion. However, MBL depletion prior to ischemia/reperfusion using a monoclonal antibody, transiently and specifically inhibited 75% of LP activity and ameliorated the AP consumption at 24h. To further assess complement activation during renal IRI, we monitored serum sC5b-9 and found that it was only significantly increased 72h post-reperfusion, but not when rats were pre-treated with anti-MBL or after sham surgery. In conclusion the described assays enable sensitive, reproducible and comprehensive assessment of complement activation in experimental rat models. PMID:24953215

  20. C-Type Lectin-Like Receptors of the Dectin-1 Cluster: Ligands and Signaling Pathways

    PubMed Central

    Plato, Anthony; Willment, Janet A.

    2013-01-01

    Innate immunity is constructed around genetically encoded receptors that survey the intracellular and extracellular environments for signs of invading microorganisms. These receptors recognise the invader and through complex intracellular networks of molecular signaling, they destroy the threat whilst instructing effective adaptive immune responses. Many of these receptors, like the Toll-like receptors in particular, are well-known for their ability to mediate downstream responses upon recognition of exogenous or endogenous ligands; however, the emerging family known as the C-type lectin-like receptors contains many members that have a huge impact on immune and homeostatic regulation. Of particular interest here are the C-type lectin-like receptors that make up the Dectin-1 cluster and their intracellular signaling motifs that mediate their functions. In this review, we aim to draw together current knowledge of ligands, motifs and signaling pathways, present downstream of Dectin-1 cluster receptors, and discuss how these dictate their role within biological systems. PMID:23570314

  1. Blockade of Alternative Complement Pathway in Dense Deposit Disease

    PubMed Central

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

    2014-01-01

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

  2. Inhibition of the alternative complement pathway preserves photoreceptors after retinal injury.

    PubMed

    Sweigard, J Harry; Matsumoto, Hidetaka; Smith, Kaylee E; Kim, Leo A; Paschalis, Eleftherios I; Okonuki, Yoko; Castillejos, Alexandra; Kataoka, Keiko; Hasegawa, Eiichi; Yanai, Ryoji; Husain, Deeba; Lambris, John D; Vavvas, Demetrios; Miller, Joan W; Connor, Kip M

    2015-07-22

    Degeneration of photoreceptors is a primary cause of vision loss worldwide, making the underlying mechanisms surrounding photoreceptor cell death critical to developing new treatment strategies. Retinal detachment, characterized by the separation of photoreceptors from the underlying retinal pigment epithelium, is a sight-threatening event that can happen in a number of retinal diseases. The detached photoreceptors undergo apoptosis and programmed necrosis. Given that photoreceptors are nondividing cells, their loss leads to irreversible visual impairment even after successful retinal reattachment surgery. To better understand the underlying disease mechanisms, we analyzed innate immune system regulators in the vitreous of human patients with retinal detachment and correlated the results with findings in a mouse model of retinal detachment. We identified the alternative complement pathway as promoting early photoreceptor cell death during retinal detachment. Photoreceptors down-regulate membrane-bound inhibitors of complement, allowing for selective targeting by the alternative complement pathway. When photoreceptors in the detached retina were removed from the primary source of oxygen and nutrients (choroidal vascular bed), the retina became hypoxic, leading to an up-regulation of complement factor B, a key mediator of the alternative pathway. Inhibition of the alternative complement pathway in knockout mice or through pharmacological means ameliorated photoreceptor cell death during retinal detachment. Our current study begins to outline the mechanism by which the alternative complement pathway facilitates photoreceptor cell death in the damaged retina. PMID:26203084

  3. l-Ficolin binding and lectin pathway activation by acetylated low-density lipoprotein

    PubMed Central

    Faro, J; Chen, Y; Jhaveri, P; Oza, P; Spear, G T; Lint, T F; Gewurz, H

    2008-01-01

    l-Ficolin, like mannan-binding lectin (MBL), is a lectin pathway activator present in normal human plasma. Upon binding ligand, l-ficolin similarly initiates C4 cleavage via the serine protease MBL-associated serine protease-2 (MASP-2). We sought further insight into l-ficolin binding reactions and MASP-2 activation by passing plasma through GlcNAc-derivatized Sepharose. l-Ficolin bound in 1·0 M NaCl-ethylenediamine tetraacetic acid (EDTA), and remained bound in NaCl-free EDTA, while MASP-2 eluted in proenzyme form (?20% yield, > 40 000-fold purification). l-Ficolin was eluted with GlcNAc in 1·0 M NaCl (?10% yield, > 3000-fold purification), with trace amounts of C3, ?2-macroglobulin and both native and activated MASP-2. These preparations were utilized to investigate l-ficolin reactivities with acetylated low-density lipoprotein (A-LDL) as a model ligand in albumin-free systems. l-Ficolin bound strongly to A-LDL in the absence as well as presence of calcium, including saline-EDTA, and was optimal in 1·0 M NaCl-EDTA, but binding failed to occur in EDTA in the absence of NaCl. The addition of l-ficolin to immobilized A-LDL resulted in activation of MASP-2 in unmodified but not ficolin-depleted plasma unless l-ficolin was restored. We conclude that A-LDL is a useful ligand for investigation of l-ficolin function; both binding and activation are optimally examined in systems free of albumin; and ligand binding in 1·0 M NaCl in EDTA can be useful in the isolation of l-ficolin and native MASP-2. PMID:18031558

  4. Increased cytotoxicity of normal rabbit serum for lectin-resistant mutants of animal cells

    PubMed Central

    1984-01-01

    Plant lectins are cytotoxic and can be used to select for mutants of animal cells that exhibit structural changes in cell surface carbohydrates reflecting glycosylation defects. We isolated eight lectin mutants of Chinese hamster ovary (CHO) cells that appear to represent three different phenotype classes. These lectin mutants were much more sensitive to the cytotoxic action of normal rabbit serum (NRS) than were the parental cells. This increased cytotoxicity was heat sensitive, specifically absorbed, and inhibited by simple and complex carbohydrates. No killing was observed under conditions in which only the alternate complement pathway was active. An NRS- resistant subclone that was isolated from one lectin mutant was shown to have also regained wild type behavior when tested with the lectins. The possibility that naturally occurring antibodies in rabbit serum are reacting with incomplete carbohydrate chains on the surface of the lectin mutants is discussed. PMID:6481303

  5. Complement activation pathways in murine immune complex-induced arthritis and in C3a and C5a generation in vitro.

    PubMed

    Banda, N K; Levitt, B; Wood, A K; Takahashi, K; Stahl, G L; Holers, V M; Arend, W P

    2010-01-01

    The alternative pathway (AP) of complement alone is capable of mediating immune complex-induced arthritis in the collagen antibody-induced arthritis (CAIA) model in mice. Whether the classical pathway (CP) or lectin pathway (LP) alone can mediate CAIA is not known. Using mice genetically deficient in different complement components, our results reported herein establish that the CP and LP alone are each incapable of mediating CAIA. A lower level or absence of C3 and/or C5 activation by the CP may be possible explanations for the importance of the AP in CAIA and in many murine models of disease. In addition, other investigators have reported that CP C5 convertase activity is absent in mouse sera. To address these questions, we employed an in vitro system of adherent immunoglobulin (Ig)G-induced complement activation using plates coated with murine anti-collagen monoclonal antibody (mAb). These experiments used complement-deficient mouse sera and wild-type mouse or normal human sera under conditions inactivating either the CP (Ca(++) deficiency) or the AP (mAb inhibitory to factor B). Robust generation of both C3a and C5a by either the AP or CP alone were observed with both mouse and human sera, although there were some small differences between the species of sera. We conclude that neither the CP nor LP alone is capable of mediating CAIA in vivo and that mouse sera exhibits a high level of IgG-induced C5a generation in vitro through either the CP or AP. PMID:19843088

  6. Differential ability to resist to complement lysis and invade host cells mediated by MBL in R4 and 860 strains of Trypanosoma cruzi.

    PubMed

    Evans-Osses, Ingrid; Mojoli, Andres; Beltrame, Marcia Holsbach; da Costa, Denise Endo; DaRocha, Wanderson Duarte; Velavan, Thirumalaisamy P; de Messias-Reason, Iara; Ramirez, Marcel Ivan

    2014-03-18

    To produce an infection Trypanosoma cruzi must evade lysis by the complement system. During early stages of infection, the lectin pathway plays an important role in host defense and can be activated by binding of mannan-binding lectin (MBL) to carbohydrates on the surface of pathogens. We hypothesized that MBL has a dual role during parasite-host cell interaction as lectin complement pathway activator and as binding molecule to invade the host cell. We used two polarized strains of T. cruzi, R4 (susceptible) and 860 (resistant) strains, to investigate the role of MBL in complement-mediated lysis. Interestingly R4, but not 860 metacyclic strain, markedly increases the invasion of host cells, suggesting that MBL drives the invasion process while the parasite deactivates the Lectin complement pathway. PMID:24560788

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

    PubMed Central

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

    2009-01-01

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

  8. Glomeruli of Dense Deposit Disease contain components of the alternative and terminal complement pathway

    PubMed Central

    Sethi, Sanjeev; Gamez, Jeffrey D.; Vrana, Julie A.; Theis, Jason D.; Bergen, H. Robert; Zipfel, Peter F.; Dogan, Ahmet; Smith, Richard J. H.

    2009-01-01

    Dense Deposit Disease (DDD), or membranoproliferative glomerulonephritis type II, is a rare renal disease characterized by dense deposits in the mesangium and along the glomerular basement membranes that can be seen by electron microscopy. Although these deposits contain complement factor C3, as determined by immunofluorescence microscopy, their precise composition remains unknown. To address this question, we used mass spectrometry to identify the proteins in laser microdissected glomeruli isolated from paraffin-embedded tissue of eight confirmed cases of DDD. Compared to glomeruli from five control patients, we found that all of the glomeruli from patients with DDD contain components of the alternative pathway and terminal complement complex. Factor C9 was uniformly present as well as the two fluid-phase regulators of terminal complement complex clusterin and vitronectin. In contrast, in nine patients with immune complex–mediated membranoproliferative glomerulonephritis, glomerular samples contained mainly immunoglobulins and complement factors C3 and C4. Our study shows that in addition to fluid-phase dysregulation of the alternative pathway, soluble components of the terminal complement complex contribute to glomerular lesions found in DDD. PMID:19177158

  9. The role of complement in membranous nephropathy

    PubMed Central

    Ma, Hong; Sandor, Dana G.; Beck, Laurence H.

    2013-01-01

    Membranous nephropathy (MN) describes a histopathological pattern of injury marked by glomerular subepithelial immune deposits and collectively represents one of the most common causes of adult nephrotic syndrome. Studies in Heymann nephritis, an experimental model of MN, have established a paradigm in which these deposits locally activate complement to cause podocyte injury, culminating in cytoskeletal reorganization, loss of slit diaphragms, and proteinuria. There is much circumstantial evidence for a prominent role of complement in human MN, as C3 and C5b-9 are consistently found within immune deposits. Secondary MN often exhibits the additional presence of C1q, implicating the classical pathway of complement activation. Primary MN, however, is IgG4-predominant and IgG4 is considered incapable of binding C1q and activating the complement pathway. Recent studies have identified the M-type phospholipase A2 receptor (PLA2R) as the major target antigen in primary MN. Early evidence hints that IgG4 anti-PLA2R autoantibodies can bind mannan-binding lectin and activate the lectin complement pathway. The identification of anti-PLA2R antibodies as likely participants in the pathogenesis of disease will allow focused investigation into the role of complement in MN. Definitive therapy for MN is immunosuppression, although future therapeutic agents that specifically target complement activation may represent an effective temporizing measure to forestall further glomerular injury. PMID:24161038

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-07-01

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

  12. Role of N-linked glycan in the unfolding pathway of Erythrina corallodendron lectin.

    PubMed

    Mitra, Nivedita; Sharon, Nathan; Surolia, Avadhesha

    2003-10-28

    Erythrina corallodendron lectin (ECorL) exhibits an exquisitely structured oligosaccharide chain. Interestingly, the bacterially expressed, nonglycosylated counterpart, rECorL, possesses an essentially identical carbohydrate specificity and agglutinating activity as the glycosylated lectin, thus suggesting that the overall structure of the two are identical. This paper reports the unfolding behavior of E. corallodendron lectin in its glycosylated (EcorL) and nonglycosylated (rECorL) forms. ECorL shows a two-state unfolding pattern during isothermal melts and differential scanning calorimetry (DSC). The T(g) of ECorL as obtained from isothermal melts is 74 degrees C at pH 7.4. The T(p) obtained from DSC studies is between 74.8 to 68.1 degrees C in the pH range of 5.26-7.77. The recombinant lectin (rECorL), which is devoid of carbohydrate, shows, in contrast to the glycosylated protein, a non-two-state unfolding profile as measured by both probes mentioned, but the number of intermediates during unfolding could not be ascertained. Simulated annealing on ECorL, with the sugars removed, reveals that the protein Calpha backbones overlap, indicating that the overall structure, including the mode of dimerization, of rECorL is insignificantly altered as compared to ECorL. The alterations in the folding behavior of rECorL as compared to that observed in ECorL may be due to the fact that, unlike most other glycoproteins, one of the glycans in ECorL is unusually structured and forms many hydrogen bonds with the protein. It therefore appears that while the covalently linked sugar does not contribute appreciably to the final folded structure of ECorL, it does alter its folding process in a significant manner. PMID:14567682

  13. Resistance against the membrane attack complex of complement induced in porcine endothelial cells with a Gal alpha(1-3)Gal binding lectin: up-regulation of CD59 expression.

    PubMed

    Dalmasso, A P; Benson, B A; Johnson, J S; Lancto, C; Abrahamsen, M S

    2000-04-01

    Endothelial cells (EC) play central roles in vascular physiology and pathophysiology. EC activation results in proinflammatory activities with production of cytokines and expression of adhesion molecules. However, we have shown before in a model of xenotransplantation that prolonged stimulation of porcine EC with human anti-porcine IgM natural Abs can activate the cells to become resistant against cytotoxicity by the membrane attack complex of complement (MAC). Now we report the major characteristics of induction and maintenance of resistance elicited in porcine EC with Bandeiraea simplicifolia lectin that binds terminal gal alpha(1-3)gal. Lectin-treated cells underwent little or no cytotoxicity and PGI2 release when exposed to MAC. Induction of resistance required incubation of the EC with lectin for 4 h but was not fully manifested until 16 h later. Most of the initially bound lectin remained on the cell surface for >60 h. EC-bound lectin did not inhibit binding of IgM natural Abs or activation and binding of C components, including C9, but a C-induced permeability channel of reduced size was present. Induction of resistance required protein synthesis, developed slowly, and was associated with up-regulation of expression of mRNA for the MAC inhibitor CD59 and membrane-associated CD59 protein. Resistance lasted at least 3 days, and the cells regained normal morphology and were metabolically active. This induced resistance may have a physiologic counterpart that might be amenable to pharmacologic manipulation in vascular endothelium pathophysiology. PMID:10725736

  14. Complement alternative pathway genetic variation and Dengue infection in the Thai population

    PubMed Central

    Kraivong, R; Vasanawathana, S; Limpitikul, W; Malasit, P; Tangthawornchaikul, N; Botto, M; Screaton, G R; Mongkolsapaya, J; Pickering, M C

    2013-01-01

    Dengue disease is a mosquito-borne infection caused by Dengue virus. Infection may be asymptomatic or variably manifest as mild Dengue fever (DF) to the most severe form, Dengue haemorrhagic fever (DHF). Mechanisms that influence disease severity are not understood. Complement, an integral component of the immune system, is activated during Dengue infection and the degree of activation increases with disease severity. Activation of the complement alternative pathway is influenced by polymorphisms within activation (factor B rs12614/rs641153, C3 rs2230199) and regulatory [complement factor H (CFH) rs800292] proteins, collectively termed a complotype. Here, we tested the hypothesis that the complotype influences disease severity during secondary Dengue infection. In addition to the complotype, we also assessed two other disease-associated CFH polymorphisms (rs1061170, rs3753394) and a structural polymorphism within the CFH protein family. We did not detect any significant association between the examined polymorphisms and Dengue infection severity in the Thai population. However, the minor allele frequencies of the factor B and C3 polymorphisms were less than 10%, so our study was not sufficiently powered to detect an association at these loci. We were also unable to detect a direct interaction between CFH and Dengue NS1 using both recombinant NS1 and DV2-infected culture supernatants. We conclude that the complotype does not influence secondary Dengue infection severity in the Thai population. PMID:23919682

  15. EFFECT OF C3 GENOTYPES UPON THE ACTIVITY OF THE ALTERNATIVE PATHWAY OF COMPLEMENT ACTIVATION IN DIFFERENT SHEEP BREEDS

    Microsoft Academic Search

    L. SOTIROV; M. DJORBINEVA; I. DIMITROV

    2006-01-01

    Summary Sotirov, L., M. Djorbineva & I. Dimitrov, 2006. Effect of C3 genotypes upon the activity of the alternative pathway of complement activation in different sheep breeds. Bulg. J. Vet. Med. , 9, No 2, 99 ?105. The effect of C3 genotypes (FF, FF1, FS, SS) upon the activity of the alternative pathway of comple- ment activation (APCA) was studied

  16. The Complement System in Schizophrenia

    PubMed Central

    Mayilyan, Karine R.; Weinberger, Daniel R.; Sim, Robert B.

    2009-01-01

    summary Several lines of evidence suggest that immunological factors contribute to schizophrenia. Since 1989, the role of complement, a major effector of innate immunity and an adjuvant of adaptive immunity, has been explored in schizophrenia. Increased activity of C1, C3, C4 complement components in schizophrenia has been reported by two or more groups. Two studies on different subject cohorts showed increased MBL-MASP-2 activity in patients versus controls. More then one report indicated a significant high frequency of FB*F allotype and low prevalence of the FS phenotype of complement factor B in schizophrenia. From the data reported, it is likely that the disorder is accompanied by alterations of the complement classical and lectin pathways, which undergo dynamic changes, depending on the illness course and the state of neuro-immune crosstalk. Recent findings, implicating complement in neurogenesis, synapse remodeling and pruning during brain development, suggest a reexamination of the potential role of complement in neurodevelopmental processes contributing to schizophrenia susceptibility. It is plausible that the multicomponent complement system has more than one dimensional association with schizophrenia susceptibility, pathopsychology and illness course, understanding of which will bring a new perspective for possible immunomodulation and immunocorrection of the disease. PMID:18560619

  17. Deficiency in mannose-binding lectin-associated serine protease-2 does not increase susceptibility to Trypanosoma cruzi infection.

    PubMed

    Ribeiro, Carolina H; Lynch, Nicholas J; Stover, Cordula M; Ali, Youssif M; Valck, Carolina; Noya-Leal, Francisca; Schwaeble, Wilhelm J; Ferreira, Arturo

    2015-02-01

    Trypanosoma cruzi is the causative agent of Chagas' disease, a chronic illness affecting 10 million people around the world. The complement system plays an important role in fighting microbial infections. The recognition molecules of the lectin pathway of complement activation, mannose-binding lectin (MBL), ficolins, and CL-11, bind to specific carbohydrates on pathogens, triggering complement activation through MBL-associated serine protease-2 (MASP-2). Previous in vitro work showed that human MBL and ficolins contribute to T. cruzi lysis. However, MBL-deficient mice are only moderately compromised in their defense against the parasite, as they may still activate the lectin pathway through ficolins and CL-11. Here, we assessed MASP-2-deficient mice, the only presently available mouse line with total lectin pathway deficiency, for a phenotype in T. cruzi infection. Total absence of lectin pathway functional activity did not confer higher susceptibility to T. cruzi infection, suggesting that it plays a minor role in the immune response against this parasite. PMID:25548381

  18. Floridoside extracted from the red alga Mastocarpus stellatus is a potent activator of the classical complement pathway.

    PubMed

    Courtois, Anthony; Simon-Colin, Christelle; Boisset, Claire; Berthou, Christian; Deslandes, Eric; Guézennec, Jean; Bordron, Anne

    2008-01-01

    Many biological properties of algae have been found to have useful applications in human health, particularly in the fields of oncology and immunology. Floridoside, extracted from the red alga Mastocarpus stellatus, has a structure similar to the xenoantigen Gal alpha 1-3 Gal. This xenoantigen has been described to induce a high immune response in human xenografts and is mediated by natural anti-gal antibodies that activate the classical complement pathway. Based on this property, we analyzed the potential activities of floridoside on the immune system. We demonstrated that floridoside activates a complement cascade via the classical complement pathway, through the recruitment and activation of natural IgM. This algal molecule could represent an important step in the development of a potent new anticomplementary agent for use in therapeutic complement depletion. PMID:19005576

  19. The alternative pathway is required, but not alone sufficient, for retinal pathology in mouse laser-induced choroidal neovascularization

    Microsoft Academic Search

    Bärbel Rohrer; Beth Coughlin; Kannan Kunchithapautham; Qin Long; Stephen Tomlinson; Kazue Takahashi; V. Michael Holers

    2011-01-01

    Human genetic studies have demonstrated that polymorphisms in different complement proteins can increase the risk for developing AMD. There are three pathways of complement activation, classical (CP), alternative (AP), and lectin (LP), which all activate a final common pathway. Proteins encoded by the AMD risk genes participate in the AP (CFB), CP\\/LP (C2), or in the AP and final common

  20. Visualizing interactions along the Escherichia coli twin-arginine translocation pathway using protein fragment complementation.

    PubMed

    Kostecki, Jan S; Li, Haiming; Turner, Raymond J; DeLisa, Matthew P

    2010-01-01

    The twin-arginine translocation (Tat) pathway is well known for its ability to export fully folded substrate proteins out of the cytoplasm of gram-negative and gram-positive bacteria. Studies of this mechanism in Escherichia coli have identified numerous transient protein-protein interactions that guide export-competent proteins through the Tat pathway. To visualize these interactions, we have adapted bimolecular fluorescence complementation (BiFC) to detect protein-protein interactions along the Tat pathway of living cells. Fragments of the yellow fluorescent protein (YFP) were fused to soluble and transmembrane factors that participate in the translocation process including Tat substrates, Tat-specific proofreading chaperones and the integral membrane proteins TatABC that form the translocase. Fluorescence analysis of these YFP chimeras revealed a wide range of interactions such as the one between the Tat substrate dimethyl sulfoxide reductase (DmsA) and its dedicated proofreading chaperone DmsD. In addition, BiFC analysis illuminated homo- and hetero-oligomeric complexes of the TatA, TatB and TatC integral membrane proteins that were consistent with the current model of translocase assembly. In the case of TatBC assemblies, we provide the first evidence that these complexes are co-localized at the cell poles. Finally, we used this BiFC approach to capture interactions between the putative Tat receptor complex formed by TatBC and the DmsA substrate or its dedicated chaperone DmsD. Our results demonstrate that BiFC is a powerful approach for studying cytoplasmic and inner membrane interactions underlying bacterial secretory pathways. PMID:20169075

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

    PubMed Central

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

    2015-01-01

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

  2. Complement Blockade with a C1 Esterase Inhibitor in Paroxysmal Nocturnal Hemoglobinuria

    PubMed Central

    DeZern, Amy E.; Uknis, Marc; Yuan, Xuan; Mukhina, Galina L; Varela, Juan; Saye, JoAnne; Pu, Jeffrey; Brodsky, Robert A.

    2014-01-01

    Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, clonal, hematopoietic stem cell disorder that manifests with a complement-mediated hemolytic anemia, bone marrow failure and a propensity for thrombosis. These patients experience both intra- and extravascular hemolysis in the context of underlying complement activation. Currently eculizumab effectively blocks the intravascular hemolysis PNH. There remains an unmet clinical need for a complement inhibitor with activity early in the complement cascade to block complement at the classical and alternative pathways. C1 esterase inhibitor (C1INH) is an endogenous human plasma protein that has broad inhibitory activity in the complement pathway through inhibition of the classical pathway by binding C1r and C1s and inhibits the mannose-binding lectin-associated serine proteases in the lectin pathway. In this study, we show that commercially available plasma derived C1INH prevents lysis induced by the alternative complement pathway, of PNH erythrocytes in human serum. Importantly, C1INH was able to block the accumulation of C3 degradation products on CD55 deficient erythrocytes from PNH patient on eculizumab therapy. This could suggest a role for inhibition of earlier phases of the complement cascade than that currently inhibited by eculizumab for incomplete or non-responders to that therapy. PMID:25034232

  3. Complement blockade with a C1 esterase inhibitor in paroxysmal nocturnal hemoglobinuria.

    PubMed

    DeZern, Amy E; Uknis, Marc; Yuan, Xuan; Mukhina, Galina L; Varela, Juan; Saye, JoAnne; Pu, Jeffrey; Brodsky, Robert A

    2014-10-01

    Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, clonal, hematopoietic stem cell disorder that manifests with a complement-mediated hemolytic anemia, bone marrow failure, and a propensity for thrombosis. These patients experience both intra- and extravascular hemolysis in the context of underlying complement activation. Currently eculizumab effectively blocks the intravascular hemolysis PNH. There remains an unmet clinical need for a complement inhibitor with activity early in the complement cascade to block complement at the classical and alternative pathways. C1 esterase inhibitor (C1INH) is an endogenous human plasma protein that has broad inhibitory activity in the complement pathway through inhibition of the classical pathway by binding C1r and C1s and inhibits the mannose-binding lectin-associated serine proteases in the lectin pathway. In this study, we show that commercially available plasma derived C1INH prevents lysis induced by the alternative complement pathway of PNH erythrocytes in human serum. Importantly, C1INH was able to block the accumulation of C3 degradation products on CD55 deficient erythrocytes from PNH patient on eculizumab therapy. This could suggest a role for inhibition of earlier phases of the complement cascade than that currently inhibited by eculizumab for incomplete or nonresponders to that therapy. PMID:25034232

  4. Complement activation by isolated myelin: activation of the classical pathway in the absence of myelin-specific antibodies.

    PubMed Central

    Vanguri, P; Koski, C L; Silverman, B; Shin, M L

    1982-01-01

    Many pathological conditions of the central nervous system involve damage to and removal of myelin membrane. Very little is known about initiation of this membrane damage and the mechanisms of disposal of the damaged tissue. We are interested in the interaction between complement (the components of complement are designated C1, C2, C3, etc.) and myelin membranes and the possible role of complement in amplifying myelin damage and in the disposal of damaged myelin in vivo, because activation of complement generates both membrane-attack complexes and opsonin(s). In this study, we found that isolated rat or human myelin consumes complement in the absence of specific antibodies. Activation of complement was demonstrated by showing C3 cleavage in fresh serum incubated with myelin. Incubation of central nervous system myelin with C2-deficient serum produced no C3 consumption and only minor factor B conversion, thus excluding the alternative pathway of activation. Involvement of the classical pathway was shown directly by the C1 fixation and transfer assay. Myelin incubated with C2-deficient serum or with purified C1 and then washed contained C1 activity that could lyse sheep erythrocytes sensitized with anti-Forssman IgM antibody and carrying C4, together with C2 and C3-C9. Membranes in brain tissues other than myelin (heavy membrane fraction obtained on sucrose density gradient centrifugation) were unable to activate C1. Images PMID:6954480

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

    PubMed Central

    Cestari, Igor; Ramirez, Marcel I.

    2010-01-01

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

  6. Inefficient complement system clearance of Trypanosoma cruzi metacyclic trypomastigotes enables resistant strains to invade eukaryotic cells.

    PubMed

    Cestari, Igor; Ramirez, Marcel I

    2010-01-01

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

  7. Musca domestica larva lectin induces apoptosis in BEL-7402 cells through a Ca(2+)/JNK-mediated mitochondrial pathway.

    PubMed

    Wang, Chun-Ling; Xia, Yan; Nie, Jian-Zeng; Zhou, Minghui; Zhang, Rong-Ping; Niu, Li-Li; Hou, Li-Hua; Cao, Xiao-Hong

    2013-06-01

    Although Musca domestica larvae lectin (MLL) is able to inhibit cancer cell proliferation and to induce cancer cell apoptosis, the molecular mechanism(s) responsible for these processes remain elusive. In the current study, the signaling network underlying the MLL-induced apoptosis of human hepatoma BEL-7402 cell was investigated. Our data found out that MLL causes a sustained increase of the intracellular Ca(2+) and this process was prevented by the intracellular calcium chelator, BAPTA-AM, suggesting the involvement of intracellular Ca(2+) in MLL-induced cell apoptosis. MLL also causes the production of reactive oxygen species and elevates the phosphorylation status of JNK, processes associated with the increased cytoplasmic Ca(2+). The mitochondrial permeability transition pore (MPTP) opening study showed that MLL treatment of BEL-7402 cells results in the opening of MPTP and a reduction of mitochondrial transmembrane potential. In such condition, cytochrome-c was detected to be released from mitochondria to cytoplasm through the MPTP. This eventually activates caspase-3 and thus results in apoptosis of the tested BEL-7402 cells. According to a comprehensive review of all the evidence, it is concluded that MLL induces apoptosis of BEL-7402 cells through a Ca(2+)/JNK-mediated MPTP pathway. PMID:23247835

  8. Activation of the alternative complement pathway by exposure of phosphatidylethanolamine and phosphatidylserine on erythrocytes from sickle cell disease patients.

    PubMed Central

    Wang, R H; Phillips, G; Medof, M E; Mold, C

    1993-01-01

    Deoxygenation of erythrocytes from sickle cell anemia (SCA) patients alters membrane phospholipid distribution with increased exposure of phosphatidylethanolamine (PE) and phosphatidylserine (PS) on the outer leaflet. This study investigated whether altered membrane phospholipid exposure on sickle erythrocytes results in complement activation. In vitro deoxygenation of sickle but not normal erythrocytes resulted in complement activation measured by C3 binding. Additional evidence indicated that this activation was the result of the alterations in membrane phospholipids. First, complement was activated by normal erythrocytes after incubation with sodium tetrathionate, which produces similar phospholipid changes. Second, antibody was not required for complement activation by sickle or tetrathionate-treated erythrocytes. Third, the membrane regulatory proteins, decay-accelerating factor (CD55) and the C3b/C4b receptor (CD35), were normal on sickle and tetrathionate-treated erythrocytes. Finally, insertion of PE or PS into normal erythrocytes induced alternative pathway activation. SCA patients in crisis exhibited increased plasma factor Bb levels compared with baseline, and erythrocytes isolated from hospitalized SCA patients had increased levels of bound C3, indicating that alternative pathway activation occurs in vivo. Activation of complement may be a contributing factor in sickle crisis episodes, shortening the life span of erythrocytes and decreasing host defense against infections. Images PMID:7690777

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

    SciTech Connect

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

    1983-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  11. Early complement factors in the local tissue immunocomplex generated during intestinal ischemia/reperfusion injury

    PubMed Central

    Lee, Haekyung; Green, Danielle J.; Lai, Lawrence; Hou, Yunfang Joan; Jensenius, Jens C.; Liu, David; Cheong, Cheolho; Park, Chae Gyu; Zhang, Ming

    2009-01-01

    Recent work reveals that the innate immune system is able to recognize self targets and initiate an inflammatory response similar to that of pathogens. One novel example of this innate autoimmunity is ischemia/reperfusion (I/R) injury, in which reperfusion of the ischemic tissues elicits an acute inflammatory response activated by natural IgM (nIgM) binding to ischemia-specific self antigens, which are non-muscle myosin heavy chains type II (NMHC-II) subtype A and C. Subsequently, the complement lectin pathway is activated and eventually tissue injury occurs. Although earlier studies in the intestinal model showed that the classical complement pathway did not initiate I/R injury, C1q deposition was still observed in the local injured tissues by imaging analysis. Moreover, the involvement of the alternative complement pathway became unclear due to conflicting reports using different knockout mice. To explore the immediate downstream pathway following nIgM-ischemic antigen interaction, we isolated the nIgM-ischemic antigen immunocomplexes from the local tissue of animals treated in the intestinal I/R injury model, and examined the presence of initial molecules of three complement pathways. Our results showed that mannan-binding lectin (MBL), the early molecule of the lectin pathway, was present in the nIgM-ischemic Ag immunocomplex. In addition, C1q, the initial molecule of the classical pathway was also detected on the immunocomplex. However, Factor B, the early molecule in the alternative pathway, was not detected in the immunocomplex. To further examine the role of the alternative pathway in I/R injury, we utilized Factor B knockout mice in the intestinal model. Our results showed that Factor B knockout mice were not protected from local tissue injury, and their complement system was activated in the local tissues by nIgM during I/R. These results indicated that the lectin complement pathway operates immediately downstream of the nIgM-ischemic antigen interaction during intestinal I/R. Furthermore, the classical complement pathway also appears to interact with the of nIgM-ischemic antigen immunocomplex. Finally, the alternative complement pathway is not involved in I/R injury induction in the current intestinal model. PMID:20004473

  12. The complement cascade and renal disease.

    PubMed

    Ko?cielska-Kasprzak, Katarzyna; Bartoszek, Dorota; Myszka, Marta; Zabi?ska, Marcelina; Klinger, Marian

    2014-02-01

    Serum complement cascade, a part of innate immunity required for host protection against invading pathogens, is also a mediator of various forms of disease and injury. It is activated by classical, lectin, and alternative pathways that lead to activation of C3 component by C3 convertases, release of C3b opsonin, C5 conversion and eventually membrane attack complex formation. The tightly regulated activation process yields also C3a and C5a anaphylatoxins, which target a broad spectrum of immune and non-immune cells. The review discusses the involvement of the complement cascade in kidney disease pathogenesis and injury. The role of the complement pathways in autoantibody-mediated forms of glomerulonephritis (lupus nephritis, anti-glomerular basement membrane disease, anti-neutrophil cytoplasmic autoantibody-induced or membranoproliferative glomerulonephritis, membranous nephropathy), C3 glomerulopathy, atypical forms of hemolytic uremic syndrome, ischemic-reperfusion injury of transplanted kidney, and antibody-mediated renal allograft rejection are discussed. The disturbances in complement activation and regulation with underlying genetics are presented and related to observed pathology. Also promising strategies targeting the complement system in complement-related disorders are mentioned. PMID:24030732

  13. Phylogenetic aspects of the complement system.

    PubMed

    Zarkadis, I K; Mastellos, D; Lambris, J D

    2001-01-01

    During evolution two general systems of immunity have emerged: innate or, natural immunity and adaptive (acquired), or specific immunity. The innate system is phylogenetically older and is found in some form in all multicellular organisms, whereas the adaptive system appeared about 450 million years ago and is found in all vertebrates except jawless fish. The complement system in higher vertebrates plays an important role as an effector of both the innate and the acquired immune response, and also participates in various immunoregulatory processes. In lower vertebrates complement is activated by the alternative and lectin pathways and is primarily involved in the opsonization of foreign material. The Agnatha (the most primitive vertebrate species) possess the alternative and lectin pathways while cartilaginous fish are the first species in which the classical pathway appears following the emergence of immunoglobulins. The rest of the poikilothermic species, ranging from teleosts to reptilians, appear to contain a well-developed complement system resembling that of the homeothermic vertebrates. It seems that most of the complement components have appeared after the duplication of primordial genes encoding C3/C4/C5, fB/C2, C1s/C1r/MASP-1/MASP-2, and C6/C7/C8/C9 molecules, in a process that led to the formation of distinct activation pathways. However, unlike homeotherms, several species of poikilotherms (e.g. trout) have recently been shown to possess multiple forms of complement components (C3, factor B) that are structurally and functionally more diverse than those of higher vertebrates. We hypothesize that this remarkable diversity has allowed these animals to expand their innate capacity for immune recognition and response. Recent studies have also indicated the possible presence of complement receptors in protochordates and lower vertebrates. In conclusion, there is considerable evidence suggesting that the complement system is present in the entire lineage of deuterostomes, and regulatory complement components have been identified in all species beyond the protochordates, indicating that the mechanisms of complement activation and regulation have developed in parallel. PMID:11602194

  14. Manipulating the mediator: modulation of the alternative complement pathway C3 convertase in health, disease and therapy1

    PubMed Central

    Ricklin, Daniel

    2012-01-01

    The complement network is increasingly recognized as an important triage system that is able to differentiate between healthy host cells, microbial intruders, cellular debris and immune complexes, and tailor its actions accordingly. At the center of this triage mechanism is the alternative pathway C3 convertase (C3bBb), a potent enzymatic protein complex capable of rapidly converting the inert yet abundant component C3 into powerful effector fragments (C3a and C3b), thereby amplifying the initial response on unprotected surfaces and inducing a variety of effector functions. A fascinating molecular mechanism of convertase assembly and intrinsic regulation, as well as the interplay with a panel of cell surface-bound and soluble inhibitors are essential for directing complement attack to intruders and protecting healthy host cells. While efficiently keeping immune surveillance and homeostasis on track, the reliance on an intricate cascade of interaction and conversion steps also renders the C3 convertase vulnerable to derail. On the one hand, tissue damage, accumulation of debris, or polymorphisms in complement genes may unfavorably shift the balance between activation and regulation, thereby contributing to a variety of clinical conditions. On the other hand, pathogens developed powerful evasion strategies to avoid complement attack by targeting the convertase. Finally, we increasingly challenge our bodies with foreign materials such as biomaterial implants or drug delivery vehicles that may induce adverse effects that are at least partially caused by complement activation and amplification via the alternative pathway. The involvement of the C3 convertase in a range of pathological conditions put this complex into the spotlight of complement-targeted drug discovery efforts. Fortunately, the physiological regulation and microbial evasion approaches provide a rich source of inspiration for the development of powerful treatment options. This review provides insight into the current knowledge about the molecular mechanisms that drive C3 convertase activity, reveals common and divergent strategies of convertase inhibition employed by host and pathogens, and how this inhibitory arsenal can be tapped for developing therapeutic options to treat complement-related diseases. PMID:22964231

  15. Manipulating the mediator: modulation of the alternative complement pathway C3 convertase in health, disease and therapy.

    PubMed

    Ricklin, Daniel

    2012-11-01

    The complement network is increasingly recognized as an important triage system that is able to differentiate between healthy host cells, microbial intruders, cellular debris and immune complexes, and tailor its actions accordingly. At the center of this triage mechanism is the alternative pathway C3 convertase (C3bBb), a potent enzymatic protein complex capable of rapidly converting the inert yet abundant component C3 into powerful effector fragments (C3a and C3b), thereby amplifying the initial response on unprotected surfaces and inducing a variety of effector functions. A fascinating molecular mechanism of convertase assembly and intrinsic regulation, as well as the interplay with a panel of cell surface-bound and soluble inhibitors are essential for directing complement attack to intruders and protecting healthy host cells. While efficiently keeping immune surveillance and homeostasis on track, the reliance on an intricate cascade of interaction and conversion steps also renders the C3 convertase vulnerable to derail. On the one hand, tissue damage, accumulation of debris, or polymorphisms in complement genes may unfavorably shift the balance between activation and regulation, thereby contributing to a variety of clinical conditions. On the other hand, pathogens developed powerful evasion strategies to avoid complement attack by targeting the convertase. Finally, we increasingly challenge our bodies with foreign materials such as biomaterial implants or drug delivery vehicles that may induce adverse effects that are at least partially caused by complement activation and amplification via the alternative pathway. The involvement of the C3 convertase in a range of pathological conditions put this complex into the spotlight of complement-targeted drug discovery efforts. Fortunately, the physiological regulation and microbial evasion approaches provide a rich source of inspiration for the development of powerful treatment options. This review provides insight into the current knowledge about the molecular mechanisms that drive C3 convertase activity, reveals common and divergent strategies of convertase inhibition employed by host and pathogens, and how this inhibitory arsenal can be tapped for developing therapeutic options to treat complement-related diseases. PMID:22964231

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

    PubMed Central

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

    2014-01-01

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

  17. Inherited mitochondrial DNA variants can affect complement, inflammation and apoptosis pathways: insights into mitochondrial-nuclear interactions.

    PubMed

    Kenney, M Cristina; Chwa, Marilyn; Atilano, Shari R; Falatoonzadeh, Payam; Ramirez, Claudio; Malik, Deepika; Tarek, Mohamed; Cáceres-del-Carpio, Javier; Nesburn, Anthony B; Boyer, David S; Kuppermann, Baruch D; Vawter, Marquis; Jazwinski, S Michal; Miceli, Michael; Wallace, Douglas C; Udar, Nitin

    2014-07-01

    Age-related macular degeneration (AMD) is the leading cause of vision loss in developed countries. While linked to genetic polymorphisms in the complement pathway, there are many individuals with high risk alleles that do not develop AMD, suggesting that other 'modifiers' may be involved. Mitochondrial (mt) haplogroups, defined by accumulations of specific mtDNA single nucleotide polymorphisms (SNPs) which represent population origins, may be one such modifier. J haplogroup has been associated with high risk for AMD while the H haplogroup is protective. It has been difficult to assign biological consequences for haplogroups so we created human ARPE-19 cybrids (cytoplasmic hybrids), which have identical nuclei but mitochondria of either J or H haplogroups, to investigate their effects upon bioenergetics and molecular pathways. J cybrids have altered bioenergetic profiles compared with H cybrids. Q-PCR analyses show significantly lower expression levels for seven respiratory complex genes encoded by mtDNA. J and H cybrids have significantly altered expression of eight nuclear genes of the alternative complement, inflammation and apoptosis pathways. Sequencing of the entire mtDNA was carried out for all the cybrids to identify haplogroup and non-haplogroup defining SNPs. mtDNA can mediate cellular bioenergetics and expression levels of nuclear genes related to complement, inflammation and apoptosis. Sequencing data suggest that observed effects are not due to rare mtDNA variants but rather the combination of SNPs representing the J versus H haplogroups. These findings represent a paradigm shift in our concepts of mt-nuclear interactions. PMID:24584571

  18. Structural basis for the stabilization of the complement alternative pathway C3 convertase by properdin.

    PubMed

    Alcorlo, Martín; Tortajada, Agustín; Rodríguez de Córdoba, Santiago; Llorca, Oscar

    2013-08-13

    Complement is an essential component of innate immunity. Its activation results in the assembly of unstable protease complexes, denominated C3/C5 convertases, leading to inflammation and lysis. Regulatory proteins inactivate C3/C5 convertases on host surfaces to avoid collateral tissue damage. On pathogen surfaces, properdin stabilizes C3/C5 convertases to efficiently fight infection. How properdin performs this function is, however, unclear. Using electron microscopy we show that the N- and C-terminal ends of adjacent monomers in properdin oligomers conform a curly vertex that holds together the AP convertase, interacting with both the C345C and vWA domains of C3b and Bb, respectively. Properdin also promotes a large displacement of the TED (thioester-containing domain) and CUB (complement protein subcomponents C1r/C1s, urchin embryonic growth factor and bone morphogenetic protein 1) domains of C3b, which likely impairs C3-convertase inactivation by regulatory proteins. The combined effect of molecular cross-linking and structural reorganization increases stability of the C3 convertase and facilitates recruitment of fluid-phase C3 convertase to the cell surfaces. Our model explains how properdin mediates the assembly of stabilized C3/C5-convertase clusters, which helps to localize complement amplification to pathogen surfaces. PMID:23901101

  19. Evolution and diversity of the complement system of poikilothermic vertebrates.

    PubMed

    Sunyer, J O; Lambris, J D

    1998-12-01

    In mammals the complement system plays an important role in innate and acquired host defense mechanisms against infection and in various immunoregulatory processes. The complement system is an ancient defense mechanism that is already present in the invertebrate deuterostomes. In these species as well as in agnathans (the most primitive vertebrate species), both the alternative and lectin pathway of complement activation are already present, and the complement system appears to be involved mainly in opsonization of foreign material. With the emergence of immunoglobulins in cartilaginous fish, the classical and lytic pathways first appear. The rest of the poikilothermic species, from teleosts to reptilians, appear to contain a well-developed complement system resembling that of homeothermic vertebrates. However, important differences remain. Unlike homeotherms, several species of poikilotherms have recently been shown to possess multiple forms of complement components (C3 and factor B) that are structurally and functionally more diverse than those of higher vertebrates. It is noteworthy that the multiple forms of C3 that have been characterized in several teleost fish are able to bind with varying efficiencies to various complement-activating surfaces. We hypothesize that this diversity has allowed these animals to expand their innate capacity for immune recognition. PMID:9914901

  20. Complement nomenclature 2014.

    PubMed

    Kemper, Claudia; Pangburn, Michael K; Fishelson, Zvi

    2014-10-01

    The first update since 1981 of the nomenclature used in the field of complement has been completed by the Complement Nomenclature Committee established under the auspices of the International Complement Society (ICS) and by the boards of the ICS and the European Complement Network (ECN). Recommended names of complement pathways, proteins, protein complexes, protein fragments and receptors are listed. Authors are urged to use these names in their published and presented works. PMID:25081089

  1. The Alternative Activation Pathway and Complement Component C3 Are Critical for a Protective Immune Response against Pseudomonas aeruginosa in a Murine Model of Pneumonia

    Microsoft Academic Search

    Stacey L. Mueller-Ortiz; Scott M. Drouin; Rick A. Wetsel

    2004-01-01

    Pseudomonas aeruginosa is a leading cause of hospital-acquired pneumonia, and approximately 80% of patients with cystic fibrosis are infected with this bacterium. To investigate the overall role of complement and the complement activation pathways in the host defense against P. aeruginosa pulmonary infection, we chal- lenged C3-, C4-, and factor B-deficient mice with P. aeruginosa via intranasal inoculation. In these

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

    PubMed Central

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

    2011-01-01

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

  3. A comparative study of mammalian and reptilian alternative pathway of complement-mediated killing of the Lyme disease spirochete (Borrelia burgdorferi).

    PubMed

    Kuo, M M; Lane, R S; Giclas, P C

    2000-12-01

    The potential bactericidal activity of the alternative complement pathway of mammalian and reptilian sera to Borrelia burgdorferi sensu stricto (s.s.) was evaluated in vitro. Complement-mediated killing was observed when cultured spirochetes were inoculated into sera from the western fence lizard (Sceloporus occidentalis) and from the southern alligator lizard (Elgaria multicarinata), but not when they were inoculated into serum from either the deer mouse (Peromyscus maniculatus) or from humans. Spirochetes were still alive after 4 hr in lizard serum that had been preheated at 56 C for 30 min to inactivate complement. Furthermore, when lizard serum was chelated with 10 mM ethylenediaminetetraacetic acid to block all complement activation, borreliacidal activity was arrested. When lizard serum was chelated with 10 mM ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid plus 4 mM MgCl2 to block only classical complement pathway activation, >85% of spirochetes were immobilized within 1 hr. Differences in B. burgdorferi s.s. mortality were not observed when chelators with or without MgCl2 were added to serum from either deer mice or humans. Proteins comprising the alternative complement pathway are responsible for the borreliacidal activity observed in the blood of S. occidentalis and E. multicarinata. PMID:11191895

  4. Inhibitor(s) of the classical complement pathway in mouse serum limit the utility of mice as experimental models of neuromyelitis optica.

    PubMed

    Ratelade, Julien; Verkman, A S

    2014-11-01

    Neuromyelitis optica (NMO) is an inflammatory demyelinating disease of the central nervous system in which anti-aquaporin-4 (AQP4) autoantibodies (AQP4-IgG) cause damage to astrocytes by complement-dependent cytotoxicity (CDC). Various approaches have been attempted to produce NMO lesions in rodents, some involving genetically modified mice with altered immune cell function. Here, we found that mouse serum strongly inhibits complement from multiple species, preventing AQP4-IgG-dependent CDC. Effects of mouse serum on complement activation were tested in CDC assays in which AQP4-expressing cells were incubated with AQP4-IgG and complement from different species. Biochemical assays and mass spectrometry were used to characterize complement inhibitor(s) in mouse serum. Sera from different strains of mice produced almost no AQP4-IgG-dependent CDC compared with human, rat and guinea pig sera. Remarkably, addition of mouse serum prevented AQP4-IgG-dependent CDC caused by human, rat or guinea pig serum, with 50% inhibition at <5% mouse serum. Hemolysis assays indicated that the inhibitor(s) in mouse serum target the classical and not the alternative complement pathway. We found that the complement inhibitor(s) in mouse serum were contained in a serum fraction purified with protein-A resin; however, the inhibitor was not IgG as determined using serum from IgG-deficient mice. Mass spectrometry on the protein A-purified fraction produced several inhibitor candidates. The low intrinsic complement activity of mouse serum and the presence of complement inhibitor(s) limit the utility of mouse models to study disorders, such as NMO, involving the classical complement pathway. PMID:24980869

  5. Were lectins primitive Fc receptors?

    PubMed

    Hajela, K

    1991-03-01

    Co-operation between humoral and cellular pathways occurs by the interaction of antibody antigen complexes with effector cells. This interaction is mediated by receptors for the Fc region of antibody, Fc receptors (FcR). Molecular characterisation of low-affinity receptors for IgE revealed an 123-amino-acid domain homologous with the carbohydrate-binding domain of the C-type animal lectins. Although IgE is heavily glycosylated, the binding of Fc epsilon RII to IgE was found to be independent of any "lectin-like" activity. The presence on lymphoid cells of a family of adhesion molecules containing a lectin-like domain, the ability of these lectin-like molecules and surface lectins to bind immunoglobulins, and subsequently the role of carbohydrates in the binding of immunoglobulins to such surface molecules imply that the ancestral carbohydrate. recognition domain of lectins held together by conserved cystein residues has evolved as FcR to recognise the constant region of immunoglobulins. PMID:1829437

  6. Viral Bimolecular Fluorescence Complementation: A Novel Tool to Study Intracellular Vesicular Trafficking Pathways

    PubMed Central

    Johnson, Aaron L.; Pawlak, Emily N.; Cavanagh, P. Craig; Van Nynatten, Logan; Haeryfar, S. M. Mansour; Dikeakos, Jimmy D.

    2015-01-01

    The Human Immunodeficiency Virus type 1 (HIV-1) accessory protein Nef interacts with a multitude of cellular proteins, manipulating the host membrane trafficking machinery to evade immune surveillance. Nef interactions have been analyzed using various in vitro assays, co-immunoprecipitation studies, and more recently mass spectrometry. However, these methods do not evaluate Nef interactions in the context of viral infection nor do they define the sub-cellular location of these interactions. In this report, we describe a novel bimolecular fluorescence complementation (BiFC) lentiviral expression tool, termed viral BiFC, to study Nef interactions with host cellular proteins in the context of viral infection. Using the F2A cleavage site from the foot and mouth disease virus we generated a viral BiFC expression vector capable of concurrent expression of Nef and host cellular proteins; PACS-1, MHC-I and SNX18. Our studies confirmed the interaction between Nef and PACS-1, a host membrane trafficking protein involved in Nef-mediated immune evasion, and demonstrated co-localization of this complex with LAMP-1 positive endolysosomal vesicles. Furthermore, we utilized viral BiFC to localize the Nef/MHC-I interaction to an AP-1 positive endosomal compartment. Finally, viral BiFC was observed between Nef and the membrane trafficking regulator SNX18. This novel demonstration of an association between Nef and SNX18 was localized to AP-1 positive vesicles. In summary, viral BiFC is a unique tool designed to analyze the interaction between Nef and host cellular proteins by mapping the sub-cellular locations of their interactions during viral infection. PMID:25915798

  7. Genome-wide pathway-based association study implicates complement system in the development of Kashin-Beck disease in Han Chinese.

    PubMed

    Zhang, Feng; Wen, Yan; Guo, Xiong; Zhang, Yingang; Wang, Sen; Yang, Tielin; Shen, Hui; Chen, Xiangding; Tan, Lijun; Tian, Qing; Deng, Hong-Wen

    2015-02-01

    Kashin-Beck disease (KBD) is a chronic osteochondropathy. The pathogenesis of KBD remains unknown. To identify relevant biological pathways for KBD, we conducted a genome-wide pathway-based association study (GWPAS) following by replication analysis, totally using 2743 Chinese Han adults. A modified gene set enrichment algorithm was used to detect association between KBD and 963 biological pathways. Cartilage gene expression analysis and serum complement measurement were performed to evaluate the functional relevance of identified pathway with KBD. We found that the Complement and Coagulation Cascades (CACC) pathway was significantly associated with KBD (P value=3.09×10(-5), false-discovery rate=0.042). Within the CACC pathway, the most significant association was observed at rs1656966 (P value=1.97×10(-4)) of KNG1 gene. Further replication study observed that rs1656966 (P value=0.037) was significantly associated with KBD in an independent validation sample of 1026 subjects. Gene expression analysis observed that CFD (ratio=3.39±2.68), A2M (ratio=3.67±5.63), C5 (ratio=2.65±2.52) and CD46 (ratio=2.29±137) genes of the CACC pathway were up-regulated in KBD articular cartilage compared to healthy articular cartilage. The serum level of complement C5 in KBD patients were significantly higher than that in healthy controls (P value=0.038). Our study is the first to suggest that complement system-related CACC pathway contributed to the development of KBD. PMID:25305519

  8. Transcription efficiency of different chicken mannose-binding lectin promoter alleles.

    PubMed

    Kjćrup, R M; Dalgaard, T S; Norup, L R; Goto, R M; Miller, M M; Sřrensen, P; Juul-Madsen, H R

    2014-12-01

    The serum collectin mannose-binding lectin (MBL) plays a major role in innate immunity by activation of the lectin complement pathway or by acting as an opsonin. The serum levels of human and animal MBL are associated with susceptibility to a wide range of infections, and the variation of MBL in serum is genetically determined. In the chicken, 14 single nucleotide polymorphisms (SNPs) have so far been found in the MBL promoter region. In this study, the transcription activity of a 670-bp promoter region covering all 14 SNPs from the four MBL promoter alleles A1 to A4 was assessed using a dual-luciferase assay. Of the analysed alleles, A1 showed the highest transcription activity although this allele is frequently found in chickens with low MBL mRNA expression. PMID:25186068

  9. Complement and periodontitis.

    PubMed

    Hajishengallis, George

    2010-12-15

    Although the complement system is centrally involved in host defense, its overactivation or deregulation (e.g., due to inherent host genetic defects or due to pathogen subversion) may excessively amplify inflammation and contribute to immunopathology. Periodontitis is an oral infection-driven chronic inflammatory disease which exerts a systemic impact on health. This paper reviews evidence linking complement to periodontal inflammation and pathogenesis. Clinical and histological observations show a correlation between periodontal inflammatory activity and local complement activation. Certain genetic polymorphisms or deficiencies in specific complement components appear to predispose to increased susceptibility to periodontitis. Animal model studies and in vitro experiments indicate that periodontal bacteria can either inhibit or activate distinct components of the complement cascade. Porphyromonas gingivalis, a keystone species in periodontitis, subverts complement receptor 3 and C5a anaphylatoxin receptor signaling in ways that promote its adaptive fitness in the presence of non-productive inflammation. Overall, available evidence suggests that complement activation or subversion contributes to periodontal pathogenesis, although not all complement pathways or functions are necessarily destructive. Effective complement-targeted therapeutic intervention in periodontitis would require determining the precise roles of the various inductive or effector complement pathways. This information is essential as it may reveal which specific pathways need to be blocked to counteract microbial evasion and inflammatory pathology or, conversely, kept intact to promote host immunity. PMID:20599785

  10. Simultaneous Activation of Complement and Coagulation by MBL-Associated Serine Protease 2

    PubMed Central

    Krarup, Anders; Wallis, Russell; Presanis, Julia S.; Gál, Péter; Sim, Robert B.

    2007-01-01

    The complement system is an important immune mechanism mediating both recognition and elimination of foreign bodies. The lectin pathway is one pathway of three by which the complement system is activated. The characteristic protease of this pathway is Mannan-binding lectin (MBL)-associated serine protease 2 (MASP2), which cleaves complement proteins C2 and C4. We present a novel and alternative role of MASP2 in the innate immune system. We have shown that MASP2 is capable of promoting fibrinogen turnover by cleavage of prothrombin, generating thrombin. By using a truncated active form of MASP2 as well as full-length MASP2 in complex with MBL, we have shown that the thrombin generated is active and can cleave both factor XIII and fibrinogen, forming cross-linked fibrin. To explore the biological significance of these findings we showed that fibrin was covalently bound on a bacterial surface to which MBL/MASP2 complexes were bound. These findings suggest that, as has been proposed for invertebrates, limited clotting may contribute to the innate immune response. PMID:17637839

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

    Microsoft Academic Search

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

    2007-01-01

    This work evaluated a crude hydroalcoholic extract (ExT) from the pulp of the tamarind (Tamarindus indica) fruit as a source of compounds active on the complement system (CS) in vitro. ExT, previously characterized by other authors, had time and concentration dependent effects on the lytic activity of the CS. The activity of 0.8mg\\/mL of the extract on the classical\\/lectin pathways

  12. Ataxia-Telangiectasia Group D Complementing Gene (ATDC) Promotes Lung Cancer Cell Proliferation by Activating NF-?B Pathway

    PubMed Central

    Tang, Zhong-Ping; Dong, Qian-Ze; Cui, Quan-Zhe; Papavassiliou, Paulie; Wang, En-Di; Wang, En-Hua

    2013-01-01

    Previous studies suggested Ataxia-telangiectasia group D complementing gene (ATDC) as an oncogene in many types of cancer. However, its expression and biological functions in non-small cell lung cancer (NSCLC) remain unclear. Herein, we investigated its expression pattern in 109 cases of human NSCLC samples by immunohistochemistry and found that ATDC was overexpressed in 62 of 109 NSCLC samples (56.88%). ATDC overexpression correlated with histological type (p<0.0001), tumor status (p?=?0.0227) and histological differentiation (p?=?0.0002). Next, we overexpressed ATDC in normal human bronchial epithelial cell line HBE and depleted its expression in NSCLC cell lines A549 and H1299. MTT and colony formation assay showed that ATDC overexpression promoted cell proliferation while its depletion inhibited cell growth. Furthermore, cell cycle analysis showed that ATDC overexpression decreased the percentage of cells in G1 phase and increased the percentage of cells in S phase, while ATDC siRNA treatment increased the G1 phase percentage and decreased the S phase percentage. Further study revealed that ATDC overexpression could up-regulate cyclin D1 and c-Myc expression in HBE cells while its depletion down-regulated cyclin D1 and c-Myc expression in A549 and H1299 cells. In addition, ATDC overexpression was also associated with an increased proliferation index, cyclin D1 and c-Myc expression in human NSCLC samples. Further experiments demonstrated that ATDC up-regulated cyclin D1 and c-Myc expression independent of wnt/?-catenin or p53 signaling pathway. Interestingly, ATDC overexpression increased NF-?B reporter luciferase activity and p-I?B protein level. Correspondingly, NF-?B inhibitor blocked the effect of ATDC on up-regulation of cyclin D1 and c-Myc. In conclusion, we demonstrated that ATDC could promote lung cancer proliferation through NF-?B induced up-regulation of cyclin D1 and c-Myc. PMID:23776433

  13. Commercially Available Complement Component-Depleted Sera Are Unexpectedly Codepleted of Ficolin-2

    PubMed Central

    Brady, Allison M.; Geno, K. Aaron; Dalecki, Alex G.; Cheng, Xiaogang

    2014-01-01

    The ficolins are a family of innate pattern recognition molecules that are known to bind acetylated compounds and activate complement through the association of mannose binding lectin (MBL)/ficolin-associated serine proteases (MASPs). Their importance has more recently become appreciated, as they have been shown to play a role in a variety of disease processes from infection to autoimmunity. While studying ficolin-2-mediated complement deposition on Streptococcus pneumoniae, we found that sera depleted of C1q or other complement components were also codepleted of ficolin-2 but not ficolin-1, ficolin-3, or MBL. MBL present in C1q-depleted sera was able to mediate complement deposition on Saccharomyces cerevisiae, suggesting the presence of MASPs. We found that complement was activated on pneumococci in C1q-depleted serum only after opsonization with exogenous recombinant ficolin-2 (rFicolin-2). Also, no complement deposition was observed in C1q-depleted serum when pneumococci were opsonized with rFicolin-2 mutated at its lysine-57 residue, where MASPs are known to associate. Thus, these depleted sera are a unique tool to study ficolin-2-mediated complement pathways; however, one should be aware that ficolin-2 is absent from complement component-depleted sera. PMID:25030054

  14. Sundanese Complementation

    ERIC Educational Resources Information Center

    Kurniawan, Eri

    2013-01-01

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

  15. Lectin-binding receptors, Na+,K(+)-ATPase, and acetylcholinesterase on immunocyte plasma membrane of Limulus polyphemus.

    PubMed

    Gupta, A P; Orenberg, S D; Das, Y T; Chattopadhyay, S K

    1991-05-01

    Plasma membrane receptors are crucial for nonself tissue recognition. Using concanavalin A (Con A), wheat germ agglutinin, peanut agglutinin, soybean agglutinin (SBA), and winged pea agglutinin, five lectin-binding receptor molecules have been recognized on the plasma membrane of the granulocyte (immunocyte) of the horseshoe crab, Limulus polyphemus. Only Con A and SBA caused capping of surface receptors. On the basis of the known functions of these lectin-binding receptor molecules in other invertebrates and vertebrates, their roles in phagocytosis, encapsulation, signaling, and possibly in complement pathway activation are postulated. In addition to lectin-binding receptors, Na+,K(+)-ATPase and acetylcholinesterase were detected on the plasma membrane. Because Limulus dates back to some 200 million years, the antiquity of these molecules is suggested. Furthermore, some of the lectin-binding surface receptors have the potential to be used as markers to separate different kinds of hemocytes in higher arthropods and to distinguish between normal and neoplastic cells in humans. PMID:1849829

  16. 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

  17. CMAP: Complement Map Database

    PubMed Central

    Yang, Kun; Dinasarapu, Ashok R.; Reis, Edimara S.; DeAngelis, Robert A.; Ricklin, Daniel; Subramaniam, Shankar; Lambris, John D.

    2013-01-01

    Summary: The human complement system is increasingly perceived as an intricate protein network of effectors, inhibitors and regulators that drives critical processes in health and disease and extensively communicates with associated physiological pathways ranging from immunity and inflammation to homeostasis and development. A steady stream of experimental data reveals new fascinating connections at a rapid pace; although opening unique opportunities for research discoveries, the comprehensiveness and large diversity of experimental methods, nomenclatures and publication sources renders it highly challenging to keep up with the essential findings. With the Complement Map Database (CMAP), we have created a novel and easily accessible research tool to assist the complement community and scientists from related disciplines in exploring the complement network and discovering new connections. Availability: http://www.complement.us/cmap. Contact: lambris@upenn.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:23661693

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

    SciTech Connect

    Pujari, Radha [National Centre for Cell Science, Ganeshkhind, Pune 411007 (India)] [National Centre for Cell Science, Ganeshkhind, Pune 411007 (India); Eligar, Sachin M. [Department of Biochemistry, Karnatak University, Dharwad, 580003 Karnataka (India)] [Department of Biochemistry, Karnatak University, Dharwad, 580003 Karnataka (India); Kumar, Natesh [National Centre for Cell Science, Ganeshkhind, Pune 411007 (India)] [National Centre for Cell Science, Ganeshkhind, Pune 411007 (India); Nagre, Nagaraja N.; Inamdar, Shashikala R.; Swamy, Bale M. [Department of Biochemistry, Karnatak University, Dharwad, 580003 Karnataka (India)] [Department of Biochemistry, Karnatak University, Dharwad, 580003 Karnataka (India); Shastry, Padma, E-mail: padma@nccs.res.in [National Centre for Cell Science, Ganeshkhind, Pune 411007 (India)] [National Centre for Cell Science, Ganeshkhind, Pune 411007 (India)

    2012-03-23

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

  19. Lectins with potential for anti-cancer therapy.

    PubMed

    Yau, Tammy; Dan, Xiuli; Ng, Charlene Cheuk Wing; Ng, Tzi Bun

    2015-01-01

    This article reviews lectins of animal and plant origin that induce apoptosis and autophagy of cancer cells and hence possess the potential of being developed into anticancer drugs. Apoptosis-inducing lectins encompass galectins, C-type lectins, annexins, Haliotis discus discus lectin, Polygonatum odoratum lectin, mistletoe lectin, and concanavalin A, fucose-binding Dicentrarchus labrax lectin, and Strongylocentrotus purpuratus lectin, Polygonatum odoratum lectin, and mistletoe lectin, Polygonatum odoratum lectin, autophagy inducing lectins include annexins and Polygonatum odoratum lectin. PMID:25730388

  20. Complement Activation by Merozoite Antigens of Plasmodium falciparum

    PubMed Central

    Korir, Jackson C.; Nyakoe, Nancy K.; Awinda, George; Waitumbi, John N.

    2014-01-01

    Background Complement (C) is a crucial part of the innate immune system and becomes over activated during malaria, resulting in depletion of C components, especially those for lectin pathway (LP), thereby compromising the host's innate defense. In this study, involvement of P. falciparum antigens in C activation was investigated. Methods A highly synchronous culture of the Dd2 clone of P. falciparum was established in a serum free medium. Supernatants harvested from rings, trophozoites and schizonts at various parasite densities were tested for ability to activate C by quantifying amount of C3b deposited on erythrocytes (E). Uninfected sham culture was used as control. Remnants of each C pathway were determined using Wieslab complement System Screenkit (Euro-diagnostica, Sweden). To identify MBL binding antigens of LP, culture supernatants were added to MBL sepharose columns and trapped antigens eluted with increasing concentrations of EDTA (10 mM, 50 mM and 100 mM) and then desalted before being tested for ability to activate C. The EDTA eluate with highest activity was run on a polyacrylamide gel and silver stained proteins analyzed by mass spectroscopy. Results Antigens released by P. falciparum growing in culture activated C leading to C3b deposition on E. Maximal activation at 7% parasitemia was associated with schizont stage (36.7%) compared to 22% for rings, 21% for trophozoites and 3% for sham culture. All the three pathways of C were activated, with highest activation being for the alternative pathway (only 6% of C activation potential remained), 65% for classiical and 43% for the LP. Seven MBL binding merozoite proteins were identified by mass spectrometry in the 50 mM EDTA eluate. Conclusions MBL binding merozoite adhesins with ability to activate C pathway were identified. The survival advantage for such pronounced C activation is unclear, but opsonisation could facilitate recognition and invasion of E. PMID:25144772

  1. C3 dysregulation due to factor H deficiency is mannan-binding lectin-associated serine proteases (MASP)-1 and MASP-3 independent in vivo

    PubMed Central

    Ruseva, M M; Takahashi, M; Fujita, T; Pickering, M C

    2014-01-01

    Uncontrolled activation of the complement alternative pathway is associated with complement-mediated renal disease. Factor B and factor D are essential components of this pathway, while factor H (FH) is its major regulator. In complete FH deficiency, uncontrolled C3 activation through the alternative pathway results in plasma C3 depletion and complement-mediated renal disease. These are dependent on factor B. Mannan-binding lectin-associated serine proteases 1 and 3 (MASP-1, MASP-3) have been shown recently to contribute to alternative pathway activation by cleaving pro-factor D to its active form, factor D. We studied the contribution of MASP-1 and MASP-3 to uncontrolled alternative pathway activation in experimental complete FH deficiency. Co-deficiency of FH and MASP-1/MASP-3 did not ameliorate either the plasma C3 activation or glomerular C3 accumulation in FH-deficient mice. Our data indicate that MASP-1 and MASP-3 are not essential for alternative pathway activation in complete FH deficiency. PMID:24279761

  2. Differential expression of the murine mannose-binding lectins A and C in lymphoid and nonlymphoid organs and tissues.

    PubMed

    Wagner, Swen; Lynch, Nicholas J; Walter, Wolfgang; Schwaeble, Wilhelm J; Loos, Michael

    2003-02-01

    Mannose-binding lectin (MBL), a member of the collectin family, binds to carbohydrate structures on the surfaces of micro-organisms and may serve as a recognition molecule of the lectin pathway of complement activation. In rodents two forms, MBL-A and MBL-C, were described and shown to be products of two related, but uncoupled, genes. The liver is the main source of MBL biosynthesis. For rat MBL-A, expression has also been described in the kidney. Here we report that the two forms of murine MBL are differentially expressed in a number of nonhepatic tissues. Real-time RT-PCR revealed that the liver is the major site of expression for both MBL genes. Lower copy numbers were found in kidney, brain, spleen, and muscle. In testis, only the MBL-A gene is expressed, whereas MBL-C is exclusively expressed in small intestine. Using in situ hybridization and immunohistochemistry, we demonstrate that both MBLs are synthesized by hepatocytes and show MBL expression in cells of the monocyte/macrophage lineage. In the kidney MBL-A, but not MBL-C, was found to be synthesized. Vice versa, only MBL-C biosynthesis was detected in endothelial cells of the small intestine. The latter finding may support the view that MBL-C, as part of the innate immune system, may be a counterpart of secretory IgA of the acquired immune system in preventing, for example, microbial invasion and colonization. Our findings demonstrate that MBL-A and MBL-C are differentially expressed, implying distinct biological roles for both recognition molecules of the murine lectin pathway of complement. PMID:12538708

  3. Alternative pathway of complement: recruitment of precursor properdin by the labile C3/C5 convertase and the potentiation of the pathway

    PubMed Central

    1976-01-01

    In this study the physiological role of properdin and the differential subunit composition of the solid phase enzymes of the pathway have been explored. Cell-bound C3 and C5 convertase differ in their C3b requirement. Apparently one molecule of C3b is sufficient to allow formation of C3 convertase (C3b,B), whereas two or more are required for generation of C5 convertase (C3bn,B). This conclusion was drawn from results indicating the critical role of the spacial distribution of C3b molecules on the cell surface in enzyme formation. While the C3/C5 convertase is fully capable of acting on C5 and thereby initiating the assembly of the cytolytic membrane attack complex, it is exceedingly labile and vulnerable to destruction by the C3b inactivator. It is the apparent role of properdin to confer a degree of stability upon the labile enzyme and to protect its C3 convertase function against enzymatic destruction. To achieve these effects, precursor properdin (pre-P) is recruited in a binding-activation reaction by the labile C3/C5 convertase. Multiple C3b molecules appear to be needed for the formation of properdin-activating principle. Three modes of regulation have been described, which involve spontaneous dissociation enzymatic degradation by C3b inactivator and disassembly by beta1H. The functional differences of pre-P and activated properdin (P) were delineated, pre-P displaying a weak affinity for C3b and P the capacity of strong interaction, P generating a soluble C3 convertase in serum and pre-P being unable to do so. Because of the profound differences between native pre-P and the laboratory product P, the question was raised as to whether soluble P represents an unphysiological form of the protein. On the basis of this and other studies, the conclusion was reached that in vitro properdin recruitment constitutes the terminal event of the properdin pathway, and that properdin augments the function of C3/C5 convertase without changing its substrate specificity. PMID:978134

  4. Structural and functional diversity of the lectin repertoire in teleost fish: Relevance to innate and adaptive immunity

    PubMed Central

    Vasta, Gerardo R.; Nita-Lazar, Mihai; Giomarelli, Barbara; Ahmed, Hafiz; Du, Shaojun; Cammarata, Matteo; Parrinello, Nicolň; Bianchet, Mario A.; Amzel, L. Mario

    2012-01-01

    Protein–carbohydrate interactions mediated by lectins have been recognized as key components of innate immunity in vertebrates and invertebrates, not only for recognition of potential pathogens, but also for participating in downstream effector functions, such as their agglutination, immobilization, and complement-mediated opsonization and killing. More recently, lectins have been identified as critical regulators of mammalian adaptive immune responses. Fish are endowed with virtually all components of the mammalian adaptive immunity, and are equipped with a complex lectin repertoire. In this review, we discuss evidence suggesting that: (a) lectin repertoires in teleost fish are highly diversified, and include not only representatives of the lectin families described in mammals, but also members of lectin families described for the first time in fish species; (b) the tissue-specific expression and localization of the diverse lectin repertoires and their molecular partners is consistent with their distinct biological roles in innate and adaptive immunity; (c) although some lectins may bind endogenous ligands, others bind sugars on the surface of potential pathogens; (d) in addition to pathogen recognition and opsonization, some lectins display additional effector roles, such as complement activation and regulation of immune functions; (e) some lectins that recognize exogenous ligands mediate processes unrelated to immunity: they may act as anti-freeze proteins or prevent polyspermia during fertilization. PMID:21896283

  5. Distinct Polymer Architecture Mediates Switching of Complement Activation

    E-print Network

    Distinct Polymer Architecture Mediates Switching of Complement Activation Pathways to surface-immobilized PEO of various configurations on model nanoparticles, and the initiation of complement complement activation differently. Alteration of copolymer architecture on nanospheres from mushroom to brush

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

    PubMed Central

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

    2013-01-01

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

  7. Disease associations of mannose-binding lectin & potential of replacement therapy.

    PubMed

    Gupta, Kshitij; Gupta, R K; Hajela, Krishnan

    2008-05-01

    Mannose-binding lectin (MBL) is an important component of the immune defence able to bind to repeating mannose based structural patterns typical of microbial surface (bacteria, viruses, fungi, parasites) leading to opsonization and phagocytosis, and activation of the complement pathway resulting in lysis of the pathogen. MBL thus plays a very important role in the first line of host immune response. MBL deficiency has been implicated in susceptibility and modulating the severity in viral, bacterial, fungal, and protozoan infections. High MBL levels, on the contrary might be helpful to intracellular organisms, which take the advantage of C3 opsonization and C3 receptor on monocytes/macrophages to enter their host. MBL replacement therapy to help patients with MBL deficiency has undergone phase I clinical trials. Phase II and III trials and production of recombinant MBL for replacement therapy are currently underway. PMID:18653905

  8. 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

  9. Innate immune proteins C1q and mannan-binding lectin enhance clearance of atherogenic lipoproteins by human monocytes and macrophages.

    PubMed

    Fraser, Deborah A; Tenner, Andrea J

    2010-10-01

    Atherosclerosis is a chronic inflammatory disorder that is characterized by the accumulation of modified lipoproteins in the arterial intima. C1q and mannan-binding lectin (MBL) are not only recognition components involved in activation of inflammation via the complement cascade, but they are also able to directly modulate phagocyte activation. Studies in C1q(-/-) and MBL(-/-) mice suggest that these molecules play a protective role in the early atherosclerotic lesion in the absence of, or prior to, expression of other complement components. However, in later stages, complement activation becomes an inappropriate inflammatory response, contributing to disease pathology. Therefore, to investigate possible molecular interactions of C1q and MBL in atherosclerotic lesions, we examined the influence of C1q and MBL in the clearance of native and modified lipoproteins by human monocytes and monocyte-derived macrophages. Both C1q and MBL are shown to bind and enhance the monocyte/monocyte-derived macrophage clearance of modified forms of low-density lipoprotein (LDL), including oxidized LDL and acetylated LDL, but not native LDL. Modified forms of LDL activate the classical complement pathway, but no lectin pathway activation was detected. Interestingly, monocytes that ingested modified LDL in the presence of C1q or MBL upregulated surface CD80 and CD31, as well as CCL2 chemokine gene expression. However, C1q and MBL also significantly reduced levels of free cholesterol accumulation in monocytes and human monocyte-derived macrophages that ingested oxidized LDL, while enhancing high-density lipoprotein-specific cholesterol efflux from these cells. These results suggest a novel pathway in which C1q and MBL influence removal and metabolism of atherogenic forms of LDL in the early stages of atherosclerosis. PMID:20833838

  10. Cyborg lectins: novel leguminous lectins with unique specificities.

    PubMed

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

    2000-01-01

    Bauhinia purpurea lectin (BPA) is one of the beta-galactose-binding leguminous lectins. Leguminous lectins contain a long metal-binding loop, part of which determines their carbohydrate-binding specificities. Random mutations were introduced into a portion of the cDNA coding BPA that corresponds to the carbohydrate-binding loop of the lectin. An library of the mutant lectin expressed on the surface of lambda foo phages was screened by the panning method. Several phage clones with an affinity for mannose or N-acetylglucosamine were isolated. These results indicate the possibility of making artificial lectins (so-called "cyborg lectins") with distinct and desired carbohydrate-binding specificities. PMID:10731676

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

    PubMed Central

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

    2014-01-01

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

  12. Mannose-Binding Lectin Gene Polymorphism and Chronic Hepatitis B Infection in Children

    PubMed Central

    Erdemir, Gulin; Ozkan, Tanju B.; Ozgur, Taner; Budak, Ferah; Kilic, Sara S.; Onay, Huseyin

    2015-01-01

    Background/Aims: Mannose-binding lectin (MBL) is a member of innate immune system that activates complement system through lectin pathway. MBL deficiency is associated with susceptibility to infectious diseases. In this study, the relation between MBL gene polymorphism and chronic hepatitis B infection in children is evaluated. Patients and Methods: The study included 67 children with chronic hepatitis B and 99 healthy controls. The hepatitis B patients were divided into immuntolerant, chronic inactive, and treatment groups according to their laboratory findings. MBL gene codon 52, 54, and 57 polymorphisms were studied with polymerase chain reaction in all patients and controls. The associations of MBL gene polymorphism with clinical, laboratory, and histopathologic findings were evaluated. Results: Homozygous codon 54 polymorphism of MBL was found significantly higher in chronic hepatitis B patients than controls. Rate of the polymorphism was similar in all groups and, responsive and nonresponsive patients in the treatment group. Conclusions: The hepatitis B patients who are homozygous for codon 54 of MBL are prone to develop chronic infection. Longitudinal studies with larger groups are needed. PMID:25843194

  13. Model-driven redox pathway manipulation for improved isobutanol production in Bacillus subtilis complemented with experimental validation and metabolic profiling analysis.

    PubMed

    Qi, Haishan; Li, Shanshan; Zhao, Sumin; Huang, Di; Xia, Menglei; Wen, Jianping

    2014-01-01

    To rationally guide the improvement of isobutanol production, metabolic network and metabolic profiling analysis were performed to provide global and profound insights into cell metabolism of isobutanol-producing Bacillus subtilis. The metabolic flux distribution of strains with different isobutanol production capacity (BSUL03, BSUL04 and BSUL05) drops a hint of the importance of NADPH on isobutanol biosynthesis. Therefore, the redox pathways were redesigned in this study. To increase NADPH concentration, glucose-6-phosphate isomerase was inactivated (BSUL06) and glucose-6-phosphate dehydrogenase was overexpressed (BSUL07) successively. As expected, NADPH pool size in BSUL07 was 4.4-fold higher than that in parental strain BSUL05. However, cell growth, isobutanol yield and production were decreased by 46%, 22%, and 80%, respectively. Metabolic profiling analysis suggested that the severely imbalanced redox status might be the primary reason. To solve this problem, gene udhA of Escherichia coli encoding transhydrogenase was further overexpressed (BSUL08), which not only well balanced the cellular ratio of NAD(P)H/NAD(P)+, but also increased NADH and ATP concentration. In addition, a straightforward engineering approach for improving NADPH concentrations was employed in BSUL05 by overexpressing exogenous gene pntAB and obtained BSUL09. The performance for isobutanol production by BSUL09 was poorer than BSUL08 but better than other engineered strains. Furthermore, in fed-batch fermentation the isobutanol production and yield of BSUL08 increased by 11% and 19%, up to the value of 6.12 g/L and 0.37 C-mol isobutanol/C-mol glucose (63% of the theoretical value), respectively, compared with parental strain BSUL05. These results demonstrated that model-driven complemented with metabolic profiling analysis could serve as a useful approach in the strain improvement for higher bio-productivity in further application. PMID:24705866

  14. Improvements on the purification of mannan-binding lectin and demonstration of its Ca(2+)-independent association with a C1s-like serine protease.

    PubMed Central

    Tan, S M; Chung, M C; Kon, O L; Thiel, S; Lee, S H; Lu, J

    1996-01-01

    Mannan-binding lectin (MBL), previously called 'mannan-binding protein' or MBP, is a plasma C-type lectin which, upon binding to carbohydrate structures on micro-organisms, activates the classical pathway of complement. Purification of MBL relies on its Ca(2+)-dependent affinity for carbohydrate, but existing methods are susceptible to contamination by anti-carbohydrate antibodies. In the present study a sequential-sugar-elution method has been developed which can achieve a preparation of virtually pure MBL and its associated serine protease (MBL-associated serine protease, MASP) by two steps of affinity chromatography. In further separation of MASP from MBL, it was found that activated MASP was associated with MBL independent of Ca2+. Since MBL was found to bind to underivatized Sepharose 4B, the MBL-MASP complex was purified using Sepharose 4B and protease inhibitors were included to purify the complex with MASP in its proenzyme form. Analysis of thus-purified MBL-MASP complex by gel filtration on a Sephacryl S-300 column at pH 7.8 showed that the proenzyme MASP was also associated with MBL independently of Ca2+, but that the complex could be disrupted at a low pH (5.0). Therefore the mechanism of MBL-MASP-mediated complement activation appears to be significantly different from the C1-mediated classical pathway. PMID:8912663

  15. The Serine Protease Pic From Enteroaggregative Escherichia coli Mediates Immune Evasion by the Direct Cleavage of Complement Proteins.

    PubMed

    Abreu, Afonso G; Fraga, Tatiana R; Granados Martínez, Adriana P; Kondo, Marcia Y; Juliano, Maria A; Juliano, Luiz; Navarro-Garcia, Fernando; Isaac, Lourdes; Barbosa, Angela S; Elias, Waldir P

    2015-07-01

    Enteroaggregative and uropathogenic Escherichia coli, Shigella flexneri 2a, and the hybrid enteroaggregative/Shiga toxin-producing E. coli strain (O104:H4) are important pathogens responsible for intestinal and urinary tract infections, as well as sepsis and hemolytic uremic syndrome. They have in common the production of a serine protease called Pic. Several biological roles for Pic have been described, including protection of E. coli DH5? from complement-mediated killing. Hereby we showed that Pic significantly reduces complement activation by all 3 pathways. Pic cleaves purified C3/C3b and other proteins from the classic and lectin pathways, such as C4 and C2. Cleavage fragments of C3, C4, and C2 were also observed with HB101(pPic1) culture supernatants, and C3 cleavage sites were mapped by fluorescence resonance energy transfer peptides. Experiments using human serum as a source of complement proteins confirmed Pic proteolytic activity on these proteins. Furthermore, Pic works synergistically with the human complement regulators factor I and factor H, promoting inactivation of C3b. In the presence of both regulators, further degradation of C3 ?' chain was observed. Therefore, Pic may contribute to immune evasion of E. coli and S. flexneri, favoring invasiveness and increasing the severity of the disorders caused by these pathogens. PMID:25583166

  16. 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

  17. 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

  18. Lectin localization in human nerve by biochemically defined lectin-binding glycoproteins, neoglycoprotein and lectin-specific antibody

    Microsoft Academic Search

    H.-J. Gabius; B. Wosgien; M. Hendrys; A. Bardosi

    1991-01-01

    Molecular recognition can be mediated by protein (lectin)-carbohydrate interaction, explaining the interest in this topic. Plant lectins and, more recently, chemically glycosylated neoglycoproteins principally allow to map the occurrence of components of this putative recognition system. Labelled endogenous lectins and the lectin-binding ligands can add to the panel of glycohistochemical tools. They may be helpful to derive physicologically valid conclusions

  19. Plasma Glycoprotein Profiling for Colorectal Cancer Biomarker Identification by Lectin Glycoarray and Lectin Blot

    PubMed Central

    Qiu, Yinghua; Patwa, Tasneem H.; Xu, Li; Shedden, Kerby; Misek, David E.; Tuck, Missy; Jin, Gracie; Ruffin, Mack T.; Turgeon, Danielle K.; Synal, Sapna; Bresalier, Robert; Marcon, Norman; Brenner, Dean E.; Lubman, David M.

    2009-01-01

    Colorectal cancer (CRC) remains a major worldwide cause of cancer-related morbidity and mortality largely due to the insidious onset of the disease. The current clinical procedures utilized for disease diagnosis are invasive, unpleasant, and inconvenient; hence, the need for simple blood tests that could be used for the early detection of CRC. In this work, we have developed methods for glycoproteomics analysis to identify plasma markers with utility to assist in the detection of colorectal cancer (CRC). Following immunodepletion of the most abundant plasma proteins, the plasma N-linked glycoproteins were enriched using lectin affinity chromatography and subsequently further separated by nonporous silica reverse-phase (NPS-RP)-HPLC. Individual RP-HPLC fractions were printed on nitrocellulose coated slides which were then probed with lectins to determine glycan patterns in plasma samples from 9 normal, 5 adenoma, and 6 colorectal cancer patients. Statistical tools, including principal components analysis, hierarchical clustering, and Z-statistic analysis, were employed to identify distinctive glycosylation patterns. Patients diagnosed with colorectal cancer or adenomas were shown to have dramatically higher levels of sialylation and fucosylation as compared to normal controls. Plasma glycoproteins with aberrant glycosylation were identified by nano-LC–MS/MS, while a lectin blotting methodology was used to validate proteins with significantly altered glycosylation as a function of cancer progression. The potential markers identified in this study for diagnosis to distinguish colorectal cancer from adenoma and normal include elevated sialylation and fucosylation in complement C3, histidine-rich glycoprotein, and kininogen-1. These potential markers of colorectal cancer were subsequently validated by lectin blotting in an independent set of plasma samples obtained from 10 CRC patients, 10 patients with adenomas, and 10 normal subjects. These results demonstrate the utility of this strategy for the identification of N-linked glycan patterns as potential markers of CRC in human plasma, and may have the utility to distinguish different disease states. PMID:18311904

  20. Purification, crystallization and preliminary X-ray analysis of human mannose-binding lectin-associated serine protease-1 (MASP-1) catalytic region

    PubMed Central

    Dobó, József; Harmat, Veronika; Sebestyén, Edina; Beinrohr, László; Závodszky, Péter; Gál, Péter

    2008-01-01

    MASP-1, a multidomain serine protease, is a component of the lectin pathway of complement. Its precise function is unknown, although it seems to enhance the complement-activating capacity of MASP-2, a related enzyme. MASP-1 has also been implicated as playing a role in blood coagulation. It is mostly found associated with mannose-binding lectin (MBL) and ficolins. Early attempts to crystallize MASP-1 failed because of the inhomogeneity of the purified material. MASP-1 was shown by acidic nondenaturing PAGE to be composed of differently charged species, which are most likely to be the products of deamidation occurring during the refolding procedure. Sequential cation-exchange and anion-exchange chromatography resulted in a homogeneous material, which was successfully crystallized. The best crystal diffracted to 2.55?Ĺ resolution and belonged to space group P212121, with unit-cell parameters a = 68.4, b = 70.4, c = 121.4?Ĺ. The crystal structure of MASP-1 may help in understanding the function of this mysterious serine protease. PMID:18765903

  1. THE USE OF SELECTIVE PHARMACOLOGICAL INHIBITORS TO DELINEATE SIGNAL TRANSDUCTION PATHWAYS ACTIVATED DURING COMPLEMENT RECEPTOR-MEDIATED DEGRANULATION IN CHICKEN HETEROPHILS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Complement receptors (CR), along with Fc receptors, play a primary role in the removal of bacterial pathogens in poultry. The binding of serum-opsonized bacteria to CR results in the secretion of both toxic oxygen metabolites and anti-bacterial granules. We have previously shown that the stimulati...

  2. MASP-1 of the complement system promotes clotting via prothrombin activation.

    PubMed

    Jenny, Lorenz; Dobó, József; Gál, Péter; Schroeder, Verena

    2015-06-01

    Mannan-binding lectin-associated serine protease-1 (MASP-1), a protein of the complement lectin pathway, resembles thrombin in terms of structural features and substrate specificity, and it has been shown to activate coagulation factors. Here we studied the effects of MASP-1 on clot formation in whole blood (WB) and platelet-poor plasma (PPP) by thrombelastography and further elucidated the underlying mechanism. Cleavage of prothrombin by MASP-1 was investigated by SDS-PAGE and N-terminal sequencing of cleavage products. Addition of MASP-1 or thrombin to WB and PPP shortened the clotting time and clot formation time significantly compared to recalcified-only samples. The combination of MASP-1 and thrombin had additive effects. In a purified system, MASP-1 was able to induce clotting only in presence of prothrombin. Analysis of MASP-1-digested prothrombin confirmed that MASP-1 cleaves prothrombin at three cleavage sites. In conclusion, we have shown that MASP-1 is able to induce and promote clot formation measured in a global setting using the technique of thrombelastography. We further confirmed that MASP-1-induced clotting is dependent on prothrombin. Finally, we have demonstrated that MASP-1 cleaves prothrombin and identified its cleavage sites, suggesting that MASP-1 gives rise to an alternative active form of thrombin by cleaving at the cleavage site R393. PMID:25745807

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  5. The complement system and adverse pregnancy outcomes.

    PubMed

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

    2015-09-01

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

  6. Distal Recognition Site for Classical Pathway Convertase Located in the C345C\\/Netrin Module of Complement Component C51

    Microsoft Academic Search

    Ana Sandoval; Rong Ai; John M. Ostresh; Ronald T. Ogata

    2000-01-01

    Previous studies focused on indels in the complement C345 protein family identified a number of potential protein-protein interaction sites in components C3 and C5. Here, one of these sites in C5, near the a-chain C terminus, was examined by alanine-scanning mutagenesis at 16 of the 18 non-alanine residues in the sequence KEALQIKYNFSFRYIYPLD. Alanine substi- tutions affected activities in the highly

  7. Complement-activating polysaccharides from medicinal herbs

    Microsoft Academic Search

    Haruki Yamada; Hiroaki Kiyohara

    \\u000a The complement system consists of over 20 serum proteins including nine com-plement components (C1 to C9) and their regulators,\\u000a and is normally present in blood serum in an inactive form. The system is essential for the operation of the innate as well\\u000a as the adaptive immune defence [1]. The complement proteins can be activated through three cascade pathways: by the

  8. Gender-specific modulation of immune system complement gene expression in marine medaka Oryzias melastigma following dietary exposure of BDE-47.

    PubMed

    Ye, Roy R; Lei, Elva N Y; Lam, Michael H W; Chan, Alice K Y; Bo, Jun; van de Merwe, Jason P; Fong, Amy C C; Yang, Michael M S; Lee, J S; Segner, Helmut E; Wong, Chris K C; Wu, Rudolf S S; Au, Doris W T

    2011-08-01

    BDE-47 is one of the most widely found congeners of PBDEs in marine environments. The potential immunomodulatory effects of BDE-47 on fish complement system were studied using the marine medaka Oryzias melastigma as a model fish. Three-month-old O. melastigma were subjected to short-term (5 days) and long-term (21 days) exposure to two concentrations of BDE-47 (low dose at 290?±?172 ng/day; high dose at 580?±?344 ng/day) via dietary uptake of BDE-47 encapsulated in Artemia nauplii. Body burdens of BDE-47 and other metabolic products were analyzed in the exposed and control fish. Only a small amount of debrominated product, BDE-28, was detected, while other metabolic products were all under detection limit. Transcriptional expression of six major complement system genes involved in complement activation: C1r/s (classical pathway), MBL-2 (lectin pathway), CFP (alternative pathway), F2 (coagulation pathway), C3 (the central component of complement system), and C9 (cell lysis) were quantified in the liver of marine medaka. Endogenous expression of all six complement system genes was found to be higher in males than in females (p?complement genes were downregulated in males at day 5 (or longer), whereas in females, MBl-2, CFP, and F2 mRNAs expression were upregulated, but C3 and C9 remained stable with exposure time and dose. A significant negative relationship was found between BDE-47 body burden and mRNA expression of C1r/s, CFP, and C3 in male fish (r?=?-0.8576 to -0.9447). The above findings on changes in complement gene expression patterns indicate the complement system may be compromised in male O. melastigma upon dietary exposure to BDE-47. Distinct gender difference in expression of six major complement system genes was evident in marine medaka under resting condition and dietary BDE-47 challenge. The immunomodulatory effects of BDE-47 on transcriptional expression of these complement components in marine medaka were likely induced by the parent compound instead of biotransformed products. Our results clearly demonstrate that future direction for fish immunotoxicology and risk assessment of immunosuppressive chemicals must include parallel evaluation for both genders. PMID:22828878

  9. Meningococcal disease and the complement system

    PubMed Central

    Lewis, Lisa A; Ram, Sanjay

    2014-01-01

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

  10. 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, whitespotted 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

  11. Chicken mannose-binding lectin (MBL) gene variants with influence on MBL serum concentrations.

    PubMed

    Kjćrup, Rikke M; Norup, Liselotte R; Skjřdt, Karsten; Dalgaard, Tina S; Juul-Madsen, Helle R

    2013-06-01

    Mannose-binding lectin (MBL) plays a major role in the innate immune defence by activating the lectin complement pathway or by acting as an opsonin. Two forms of MBL have been characterised from several species, but for humans and chickens, only one form of functional MBL has been described. The human MBL2 gene is highly polymorphic, and it causes varying MBL serum levels. Several of the single-nucleotide polymorphisms (SNPs) have been associated with the severity of diseases of bacterial, viral or parasitic origin. Association between various diseases and different MBL serum levels has also been identified in chickens. In this study, two inbred chicken lines (L10L and L10H) which have been selected for low and high MBL levels in serum and four other experimental chicken lines were analysed for polymorphism in the MBL gene. The presence of polymorphisms in the MBL gene was revealed by southern blot analyses, and the differences in the serum concentrations of MBL were found to be of transcriptional origin according to real-time quantitative reverse transcription PCR analysis. Several SNPs were discovered in the promoter and the 5' untranslated region of the chicken MBL gene which resulted in the identification of six different alleles. Mapping of regulatory elements in the promoter region was performed, and SNPs that could affect the MBL serum concentration were identified. One SNP that was found to be located in a TATA box was altered in one of the six alleles only. This allele was associated with low MBL serum concentration. PMID:23455474

  12. Effects of MASP-1 of the Complement System on Activation of Coagulation Factors and Plasma Clot Formation

    PubMed Central

    Hess, Katharina; Ajjan, Ramzi; Phoenix, Fladia; Dobó, József; Gál, Péter; Schroeder, Verena

    2012-01-01

    Background Numerous interactions between the coagulation and complement systems have been shown. Recently, links between coagulation and mannan-binding lectin-associated serine protease-1 (MASP-1) of the complement lectin pathway have been proposed. Our aim was to investigate MASP-1 activation of factor XIII (FXIII), fibrinogen, prothrombin, and thrombin-activatable fibrinolysis inhibitor (TAFI) in plasma-based systems, and to analyse effects of MASP-1 on plasma clot formation, structure and lysis. Methodology/Principal Findings We used a FXIII incorporation assay and specific assays to measure the activation products prothrombin fragment F1+2, fibrinopeptide A (FPA), and activated TAFI (TAFIa). Clot formation and lysis were assessed by turbidimetric assay. Clot structure was studied by scanning electron microscopy. MASP-1 activated FXIII and, contrary to thrombin, induced FXIII activity faster in the Val34 than the Leu34 variant. MASP-1-dependent generation of F1+2, FPA and TAFIa showed a dose-dependent response in normal citrated plasma (NCP), albeit MASP-1 was much less efficient than FXa or thrombin. MASP-1 activation of prothrombin and TAFI cleavage were confirmed in purified systems. No FPA generation was observed in prothrombin-depleted plasma. MASP-1 induced clot formation in NCP, affected clot structure, and prolonged clot lysis. Conclusions/Significance We show that MASP-1 interacts with plasma clot formation on different levels and influences fibrin structure. Although MASP-1-induced fibrin formation is thrombin-dependent, MASP-1 directly activates prothrombin, FXIII and TAFI. We suggest that MASP-1, in concerted action with other complement and coagulation proteins, may play a role in fibrin clot formation. PMID:22536427

  13. A C-type lectin (LvCTL4) from Litopenaeus vannamei is a downstream molecule of the NF-?B signaling pathway and participates in antibacterial immune response.

    PubMed

    Li, Haoyang; Chen, Yonggui; Li, Ming; Wang, Sheng; Zuo, Hongliang; Xu, Xiaopeng; Weng, Shaoping; He, Jianguo; Li, Chaozheng

    2015-03-01

    C-type lectins (CTLs) play multiple roles in innate immune defense against invading pathogens in both vertebrates and invertebrates. In this study, a new C-type lectin gene from pacific white shrimp Litopenaeus vannamei (designated as LvCTL4) was cloned by rapid amplification of the cDNA ends (RACE) method. The full-length cDNA of LvCTL4 was 563 bp with open reading frame (ORF) of 471 bp encoding a polypeptide of 156 amino acids, including a putative signal sequence and a single C-type lectin-like domain (CTLD). The CTLD of 137 amino acid residues contained a mutated 'EPA' (Glu(121)-Pro(122)-Ala(123)) motif in the calcium-binding site 2 and three conserved disulfide bonds involved in structure maintenance. Tissue expression analysis showed LvCTL4 was ubiquitously distributed with high levels in gill, intestine, epithelium and hepatopancreas. The expression of LvCTL4 in gill was up-regulated in response to Vibrio parahaemolyticus challenge. RNAi knock-down of the LvCTL4 gene significantly increased mortality after V. parahaemolyticus infection. A 103 bp 5' flanking promoter sequence was obtained using the genome walking method and it contained a conserved NF-?B binding motif. Dual-Luciferase assay showed both LvDorsal and LvRelish could up regulate the promoter activity of LvCTL4. This is the first report that a shrimp C-type lectin can be regulated by both LvDorsal and LvRelish. These findings provided novel insights into the regulation of shrimp CTLs expression. PMID:25559446

  14. Infectious diseases associated with complement deficiencies.

    PubMed Central

    Figueroa, J E; Densen, P

    1991-01-01

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

  15. Lectin-probed western blot analysis.

    PubMed

    Sato, Takeshi

    2014-01-01

    Lectin-probed western blot analysis, the so-called lectin blot analysis, is a useful method to yield basic information on the glycan structures of glycoproteins, based on the carbohydrate-binding specificities of lectins. By lectin blot analysis, researchers can directly analyze the glycan structures without releasing the glycans from glycoproteins. Here, the author describes protocols for standard analysis, and applies analysis in combination with glycosidase digestion of blot. PMID:25117227

  16. Activation of mannan-binding lectin-associated serine proteases leads to generation of a fibrin clot

    PubMed Central

    Gulla, Krishana C; Gupta, Kshitij; Krarup, Anders; Gal, Peter; Schwaeble, Wilhelm J; Sim, Robert B; O’Connor, C David; Hajela, Krishnan

    2010-01-01

    The lectin pathway of complement is activated upon binding of mannan-binding lectin (MBL) or ficolins (FCNs) to their targets. Upon recognition of targets, the MBL-and FCN-associated serine proteases (MASPs) are activated, allowing them to generate the C3 convertase C4b2a. Recent findings indicate that the MASPs also activate components of the coagulation system. We have previously shown that MASP-1 has thrombin-like activity whereby it cleaves and activates fibrinogen and factor XIII. MASP-2 has factor Xa-like activity and activates prothrombin through cleavage to form thrombin. We now report that purified L-FCN-MASPs complexes, bound from serum to N-acetylcysteine-Sepharose, or MBL-MASPs complexes, bound to mannan-agarose, generate clots when incubated with calcified plasma or purified fibrinogen and factor XIII. Plasmin digestion of the clot and analysis using anti-D-dimer antibodies revealed that the clot was made up of fibrin and was similar to that generated by thrombin in normal human plasma. Fibrinopeptides A and B (FPA and FPB, respectively) were released after fibrinogen cleavage by L-FCN-MASPs complexes captured on N-acetylcysteine-Sepharose. Studies of inhibition of fibrinopeptide release indicated that the dominant pathway for clotting catalysed by the MASPs is via MASP-2 and prothrombin activation, as hirudin, a thrombin inhibitor that does not inhibit MASP-1 and MASP-2, substantially inhibits fibrinopeptide release. In the light of their potent chemoattractant effects on neutrophil and fibroblast recruitment, the MASP-mediated release of FPA and FPB may play a role in early immune activation. Additionally, MASP-catalysed deposition and polymerization of fibrin on the surface of micro-organisms may be protective by limiting the dissemination of infection. PMID:20002787

  17. Activation of mannan-binding lectin-associated serine proteases leads to generation of a fibrin clot.

    PubMed

    Gulla, Krishana C; Gupta, Kshitij; Krarup, Anders; Gal, Peter; Schwaeble, Wilhelm J; Sim, Robert B; O'Connor, C David; Hajela, Krishnan

    2010-04-01

    The lectin pathway of complement is activated upon binding of mannan-binding lectin (MBL) or ficolins (FCNs) to their targets. Upon recognition of targets, the MBL-and FCN-associated serine proteases (MASPs) are activated, allowing them to generate the C3 convertase C4b2a. Recent findings indicate that the MASPs also activate components of the coagulation system. We have previously shown that MASP-1 has thrombin-like activity whereby it cleaves and activates fibrinogen and factor XIII. MASP-2 has factor Xa-like activity and activates prothrombin through cleavage to form thrombin. We now report that purified L-FCN-MASPs complexes, bound from serum to N-acetylcysteine-Sepharose, or MBL-MASPs complexes, bound to mannan-agarose, generate clots when incubated with calcified plasma or purified fibrinogen and factor XIII. Plasmin digestion of the clot and analysis using anti-D-dimer antibodies revealed that the clot was made up of fibrin and was similar to that generated by thrombin in normal human plasma. Fibrinopeptides A and B (FPA and FPB, respectively) were released after fibrinogen cleavage by L-FCN-MASPs complexes captured on N-acetylcysteine-Sepharose. Studies of inhibition of fibrinopeptide release indicated that the dominant pathway for clotting catalysed by the MASPs is via MASP-2 and prothrombin activation, as hirudin, a thrombin inhibitor that does not inhibit MASP-1 and MASP-2, substantially inhibits fibrinopeptide release. In the light of their potent chemoattractant effects on neutrophil and fibroblast recruitment, the MASP-mediated release of FPA and FPB may play a role in early immune activation. Additionally, MASP-catalysed deposition and polymerization of fibrin on the surface of micro-organisms may be protective by limiting the dissemination of infection. PMID:20002787

  18. Role of complement receptors 1 and 2 (CD35 and CD21), C3, C4, and C5 in survival by mice of Staphylococcus aureus bacteremia.

    PubMed

    Cunnion, Kenji M; Benjamin, Daniel K; Hester, C Garren; Frank, Michael M

    2004-06-01

    Complement-mediated opsonization and phagocytosis of encapsulated serotype 5 Staphylococcus aureus are essential to host defense. We describe the effects of complement depletion and deficiencies of C4, C5, and complement receptors 1 and 2 on mouse survival after intravenous exposure to S aureus. Depletion of complement proteins in C57BL/6 mice with the use of cobra-venom factor decreased survival compared with that of controls after the induction of bacteremia with mucoid (90% mortality), encapsulated (73%), and unencapsulated (59%) S aureus strains. In this model complement is even more important in the control of infection with encapsulated S aureus (80% of clinical isolates) than in the control of infection by unencapsulated strains. C4-deficient mice demonstrated similar mortality from bacteremia caused by encapsulated S aureus compared with controls, suggesting that in the unimmunized animal the alternative complement pathway contributes more to control of bacteremia caused by encapsulated S aureus than the classical complement pathway or mannan-binding lectin pathway. C5-deficient mice (B10.D2-H2(d) H2-T18(c) Hc(0)/oSnJ) showed similar mortality when subjected to bacteremia caused by encapsulated S aureus compared with C5-sufficient (B10.D2-Hc(1) H2(d) H2-T18(c)/nSnJ) mice, suggesting that in this model the anaphylatoxin C5a and the late complement cascade are not critical to survival of bacteremia induced with the use of these strains. However, C5-deficient mice depleted of C3 with the use of cobra-venom factor had 60% decreased survival compared with untreated C5-deficient mice with bacteremia induced by encapsulated S aureus, suggesting that in this model C3 is more critical than C5 in controlling S aureus bacteremia. Complement receptor 1 (CD35) is the primary receptor for the opsonin C3b. Mice deficient in CD35/CD21 showed a 67% decrease in survival compared with normal mice, suggesting that CD35/CD21 is of major importance in the control of S aureus-induced bacteremia. PMID:15192652

  19. [The state of classical and alternative complement activation pathways in persons who participated in the cleanup of the aftereffects of the accident at the Chernobyl Atomic Power Plant].

    PubMed

    Litvina, M M; Nikonova, M F; Iarilin, A A

    1994-01-01

    The levels of T-cell activation through classical and alternative pathways were studied in persons participated in cleaning-up operations at Chernobyl N. P. P. Proliferation response of T-cells on the action of monoclonal antibody anti-CD3 (classical activation) as well as response on phytohaemagglutinin was partially decreased just as response on autologic erythrocytes in combination with phorbol 12-myristate-13 acetate (CD2-dependent alternative activation) was completely suppressed in all affected persons. Addition of interleukin 2 did not restore T-cell responses on both anti-CD3 and alternative stimulation. The different degree of decrease of T-cell responses on anti-CD3 and CD2-dependent alternative stimulation is not a result of respective alterations of cell surface CD3 and CD2 expression. PMID:7951890

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

    PubMed Central

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

    2010-01-01

    The first line of host defense is the innate immune system that includes coagulation factors and pattern recognition molecules, one of which is mannose-binding lectin (MBL). Previous studies have demonstrated that MBL deficiency increases susceptibility to infection. Several mechanisms are associated with increased susceptibility to infection, including reduced opsonophagocytic killing and reduced lectin complement pathway activation. In this study, we demonstrate that MBL and MBL-associated serine protease (MASP)-1/3 together mediate coagulation factor-like activities, including thrombin-like activity. MBL and/or MASP-1/3 deficient hosts demonstrate in vivo evidence that MBL and MASP-1/3 are involved with hemostasis following injury. Staphylococcus aureus infected MBL null mice developed disseminated intravascular coagulation (DIC), which was associated with elevated blood IL-6 levels (but not TNF-? and multi-organ inflammatory responses). Infected MBL null mice also develop liver injury. These findings suggest that MBL deficiency may manifest into DIC and organ failure during infectious diseases. PMID:20399528

  1. Histoplasma complement fixation

    MedlinePLUS

    Histoplasma complement fixation is a blood test that checks for infection due to a fungus called Histoplasma capsulatum ( H. ... for Histoplasma antibodies using a laboratory method called complement fixation. This technique checks if your body has ...

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

    PubMed Central

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

    2013-01-01

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

  3. The alternative pathway is required, but not alone sufficient, for retinal pathology in mouse laser-induced choroidal neovascularization.

    PubMed

    Rohrer, Bärbel; Coughlin, Beth; Kunchithapautham, Kannan; Long, Qin; Tomlinson, Stephen; Takahashi, Kazue; Holers, V Michael

    2011-03-01

    Human genetic studies have demonstrated that polymorphisms in different complement proteins can increase the risk for developing AMD. There are three pathways of complement activation, classical (CP), alternative (AP), and lectin (LP), which all activate a final common pathway. Proteins encoded by the AMD risk genes participate in the AP (CFB), CP/LP (C2), or in the AP and final common pathway (C3). Here we tested which pathway is essential in mouse laser-induced CNV. CNV was analyzed using single complement pathway knockouts (i.e., eliminating one complement pathway at a time), followed by a double knockout in which only the AP is present, and the CP and LP are disabled, using molecular, histological and electrophysiological outcomes. First, single-gene knockouts were analyzed and compared to wild type mice; C1q(-/-) (no CP), MBL(-/-) (no LP), and CFB(-/-) (no AP). Six days after the laser-induced lesion, mice without a functional AP had reduced CNV progression (P<0.001) and preserved ERG amplitudes, whereas those without a functional CP or LP were indistinguishable from the wild type controls (P>0.3). Second, AP-only mice (C1q(-/-)MBL(-/-)) were as protected from developing CNV as the CFB(-/-) mice. The degree of pathology in each strain correlated with protein levels of the angiogenic and anti-angiogenic protein VEGF and PEDF, respectively, as well as levels of terminal pathway activation product C5a, and C9. The analysis of complement activation pathways in mouse laser-induced CNV allows for the following conclusions. Comparing the single pathway knockouts with those having only a functional AP showed: (1) that AP activation is necessary, but not alone sufficient for injury; and (2) that initial complement activation proceeds via both the LP and CP. Thus, these data indicate an important role for the AP in the generation of complement-dependent injury in the RPE and choroid via amplification of CP- and LP-initiated complement activation. Improving our understanding of the local regulation of this pathway in the eye is essential for developing improved treatment approaches for AMD. PMID:21257205

  4. Complement activation in acne vulgaris: consumption of complement by comedones.

    PubMed Central

    Webster, G F; Leyden, J J; Nilsson, U R

    1979-01-01

    Comedones, the contents of acne lesions, were shown to consume scomplement hemolytic activity in normal serum. This consumption was stimulated by the addition of serum from patients with inflammatory acne. Absorption of acne serum with Propionibacterium acnes cells removed all stimulating activity. Immunoelectrophoretic analysis of serum incubated with comedones revealed the conversion of C3 and factor B in normal serum. The addition of acne serum resulted in cleavage of C4. In serum treated with ethylene glycol-bis(beta-aminoethyl ether)-N,N'-tetraacetic acid, only C3 and factor B were converted. This indicates that comedones may activate complement by either the classical or the alternative pathway. It is suggested that P. acnes cells in comedonal material are responsible for the complement activation. Images PMID:159261

  5. Plant lectins, from ancient sugar-binding proteins to emerging anti-cancer drugs in apoptosis and autophagy.

    PubMed

    Jiang, Q-L; Zhang, S; Tian, M; Zhang, S-Y; Xie, T; Chen, D-Y; Chen, Y-J; He, J; Liu, J; Ouyang, L; Jiang, X

    2015-02-01

    Ubiquitously distributed in different plant species, plant lectins are highly diverse carbohydrate-binding proteins of non-immune origin. They have interesting pharmacological activities and currently are of great interest to thousands of people working on biomedical research in cancer-related problems. It has been widely accepted that plant lectins affect both apoptosis and autophagy by modulating representative signalling pathways involved in Bcl-2 family, caspase family, p53, PI3K/Akt, ERK, BNIP3, Ras-Raf and ATG families, in cancer. Plant lectins may have a role as potential new anti-tumour agents in cancer drug discovery. Thus, here we summarize these findings on pathway- involved plant lectins, to provide a comprehensive perspective for further elucidating their potential role as novel anti-cancer drugs, with respect to both apoptosis and autophagy in cancer pathogenesis, and future therapy. PMID:25488051

  6. Developmental changes in the bark lectin of Sophora japonica L

    Microsoft Academic Search

    Kei'ichi Baba; Masahiro Ogawa; Atsushi Nagano; Hiroyuki Kuroda; Kazuo Sumiya

    1991-01-01

    Lectin is the major protein in the phloem tissue of S. japonica. By immunohistochemistry using anti-seed lectin antibody it was demonstrated that the lectin was localized in the ray and the axial parenchyma. Neither lectin nor other cross-reactive materials were observed in the cambium, sieve tubes and companion cells. The distribution and localization changed in relation to tissue development. Lectin

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

    E-print Network

    Tetteh-Quarcoo, Patience Borkor

    2012-06-22

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

  8. Complement activation in progressive renal disease

    PubMed Central

    Fearn, Amy; Sheerin, Neil Stephen

    2015-01-01

    Chronic kidney disease (CKD) is common and the cause of significant morbidity and mortality. The replacement of functioning nephrons by fibrosis is characteristic of progressive disease. The pathways that lead to fibrosis are not fully understood, although chronic non-resolving inflammation in the kidney is likely to drive the fibrotic response that occurs. In patients with progressive CKD there is histological evidence of inflammation in the interstitium and strategies that reduce inflammation reduce renal injury in pre-clinical models of CKD. The complement system is an integral part of the innate immune system but also augments adaptive immune responses. Complement activation is known to occur in many diverse renal diseases, including glomerulonephritis, thrombotic microangiopathies and transplant rejection. In this review we discuss current evidence that complement activation contributes to progression of CKD, how complement could cause renal inflammation and whether complement inhibition would slow progression of renal disease. PMID:25664245

  9. The C-Type Lectin Domains of Lecticans, a Family of Aggregating Chondroitin Sulfate Proteoglycans, Bind Tenascin-R by Protein-Protein Interactions Independent of Carbohydrate Moiety

    Microsoft Academic Search

    Anders Aspberg; Ryu Miura; Sandrine Bourdoulous; Motoyuki Shimonaka; Dick Heinegard; Melitta Schachner; Erkki Ruoslahti; Yu Yamaguchi

    1997-01-01

    The lecticans are a family of chondroitin sulfate proteoglycans including aggrecan, versican, neurocan, and brevican. The C-terminal globular domains of lecticans are structurally related to selectins, consisting of a C-type lectin domain flanked by epidermal growth factor and complement regulatory protein domains. The C-type lectin domain of versican has been shown to bind tenascin-R, an extracellular matrix protein specifically expressed

  10. Higher complements of combinatorial sphere arrangements Higher complements of

    E-print Network

    Berger, Clemens

    Higher complements of combinatorial sphere arrangements Higher complements of combinatorial sphere¨uck, October 8, 2009 Nice, October 15, 2009 #12;Higher complements of combinatorial sphere arrangements 1 complements of combinatorial sphere arrangements Hyperplane arrangements A (central) hyperplane arrangement

  11. The role of complement in experimental autoimmune myasthenia gravis

    PubMed Central

    Kusner, Linda L.; Kaminski, Henry J.

    2012-01-01

    Complement plays an important role in the pathophysiology of experimental autoimmune myasthenia gravis (EAMG). The deposition of IgG at the neuromuscular junction, followed by the activation and observance of C3 at the site, and finally the insertion of the membrane attack complex, which results in the destruction of the plasma membrane at the neuromuscular junction. Animal models’ of complement-deficient components show the importance of the mediated lysisin EAMG. These events have regulators that allow for the limitation in the cascade and the ability of the cell to inhibit complement at many places along the pathway. The complement regulatory proteins have many roles in reducing the activation of the complement cascade and the inflammatory pathways. Mice deficient in complement regulatory proteins, decay accelerating factor and CD59, demonstrate a significant increase in the destruction at the neuromuscular junction. Inhibition of complement-mediated lysis is an attractive therapeutic in MG. PMID:23252907

  12. Extreme high prevalence of a defective mannose-binding lectin (MBL2) genotype in native South American West Andean populations.

    PubMed

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

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  14. Classical complement pathway component C1q: purification of human C1q, isolation of C1q collagen-like and globular head fragments and production of recombinant C1q-derivatives. Functional characterization.

    PubMed

    Kojouharova, Mihaela

    2014-01-01

    The classical complement pathway (CCP) activation is a multimolecular complex, composed of three subcomponents namely C1q, C1r, and C1s. C1q is the recognition subunit of this complex and its binding to the specific targets leads to the formation of active C1, which in turn activates the CCP in an immunoglobulin-dependent or -independent manner. C1q is a hexameric glycoprotein composed of 18 polypeptide chains of three different types (A, B, and C), organized in two fragments-collagen-like (CLR) and globular head (gC1q) possessing different functional activity. The contemporary knowledge of the C1q structure allows the isolation and purification of a C1q molecule from serum by combination of different chromatography procedures including ion-exchange, size-exclusion, and affinity chromatography, as well as the isolation of CLR and gC1q by limited enzymatic hydrolysis of the native C1q molecule. In this chapter, we described methods for purification of human C1q and its CLR and gC1q fragments, as well as methods for their biochemical and functional characterization. The production and purification of recombinant C1q derivatives ghA, ghB, and ghC (globular fragments of the individual C1q chains) are also presented. PMID:24218248

  15. [Polymorphism of lectin genes in Lathyrus plants].

    PubMed

    Chubukova, O V; Ba?miev, Al Kh; Ba?miev, An Kh

    2011-07-01

    The carbohydrate-binding sequences of the lectin genes from spring vetchling Lathyrus vernus (L.) Bernh., marsh vetchling L. palustris (L.), and Gmelin's vetchling L. gmelinii (Fitsch) (Fabaceae) were determined. Computer-aided analysis revealed substantial differences between nucleotide and predicted amino acid sequences of the lectin gene regions examined in each of the three vetchling species tested. In the phylogenetic trees based on sequence similarity of carbohydrate-biding regions of legume lectins, the sequences examined formed a compact cluster with the lectin genes of the plants belonging to the tribe Fabeae. In each plant, L. vernus, L. palustris, and L. gmelinii, three different lectin-encoding genes were detected. Most of the substitutions were identified within the gene sequence responsible for coding the carbohydrate-binding protein regions. This finding may explain different affinity of these lectins to different carbohydrates, and as a consequence, can affect the plant host specificity upon development of symbiosis with rhizobium bacteria. PMID:21938955

  16. Role of complement and complement regulatory proteins in the complications of diabetes.

    PubMed

    Ghosh, Pamela; Sahoo, Rupam; Vaidya, Anand; Chorev, Michael; Halperin, Jose A

    2015-06-01

    It is well established that the organ damage that complicates human diabetes is caused by prolonged hyperglycemia, but the cellular and molecular mechanisms by which high levels of glucose cause tissue damage in humans are still not fully understood. The prevalent hypothesis explaining the mechanisms that may underlie the pathogenesis of diabetes complications includes overproduction of reactive oxygen species, increased flux through the polyol pathway, overactivity of the hexosamine pathway causing intracellular formation of advanced glycation end products, and activation of protein kinase C isoforms. In addition, experimental and clinical evidence reported in past decades supports a strong link between the complement system, complement regulatory proteins, and the pathogenesis of diabetes complications. In this article, we summarize the body of evidence that supports a role for the complement system and complement regulatory proteins in the pathogenesis of diabetic vascular complications, with specific emphasis on the role of the membrane attack complex (MAC) and of CD59, an extracellular cell membrane-anchored inhibitor of MAC formation that is inactivated by nonenzymatic glycation. We discuss a pathogenic model of human diabetic complications in which a combination of CD59 inactivation by glycation and hyperglycemia-induced complement activation increases MAC deposition, activates pathways of intracellular signaling, and induces the release of proinflammatory, prothrombotic cytokines and growth factors. Combined, complement-dependent and complement-independent mechanisms induced by high glucose promote inflammation, proliferation, and thrombosis as characteristically seen in the target organs of diabetes complications. PMID:25859860

  17. Lectins as tools in glycoconjugate research

    Microsoft Academic Search

    Albert M. Wu; Elwira Lisowska; Maria Duk; Zhangung Yang

    2009-01-01

    Lectins are ubiquitous proteins of nonimmune origin, present in plants, microorganisms, animals and humans which specifically\\u000a bind defined monosugars or oligosaccharide structures. Great progress has been made in recent years in understanding crucial\\u000a roles played by lectins in many biological processes. Elucidation of carbohydrate specificity of human and animal lectins\\u000a is of great importance for better understanding of these processes.

  18. Effects of two serine proteases from Bothrops pirajai snake venom on the complement system and the inflammatory response.

    PubMed

    Menaldo, Danilo L; Bernardes, Carolina P; Pereira, Juliana C; Silveira, Denise S C; Mamede, Carla C N; Stanziola, Leonilda; Oliveira, Fábio de; Pereira-Crott, Luciana S; Faccioli, Lúcia H; Sampaio, Suely V

    2013-04-01

    The present study aimed to evaluate the effects of two serine proteases from Bothrops pirajai snake venom, named BpirSP27 and BpirSP41, on the complement system and the inflammatory response. The effects of these enzymes on the human complement system were assessed by kinetic hemolytic assays, evaluating the hemolysis promoted by the classical/lectin (CP/LP) and alternative (AP) pathways after incubation of normal human serum with the serine proteases. The results suggested that these enzymes were able to induce modulation of CP/LP and AP at different levels: BpirSP41 showed higher inhibitory effects on the hemolytic activity of CP/LP than BpirSP27, with inhibition values close to 40% and 20%, respectively, for the highest concentration assayed. Regarding AP, both enzymes showed percentages of inhibition of the hemolytic activity around 20% for the highest concentrations tested, indicating similar effects on this complement pathway. The proinflammatory effects of B. pirajai serine proteases were evaluated regarding their ability to induce paw edema, variations in the pain threshold and leukocyte recruitment at the site of injection. Both showed mild effects on these inflammatory processes, leading to low levels of increase of paw volumes and decrease in pain thresholds in rats up to 6 h after injection, and inducing neutrophil recruitment without significant increases in the total number of leukocytes in the inflammatory exudates after 6 and 24 h of administration into mice peritoneal cavity. These results suggest that serine proteases must present a minor role in the inflammation caused by B. pirajai snake venom. PMID:23499645

  19. Complementizer Drop And IP Complementation in Japanese

    E-print Network

    Fukuda, Minoru

    2000-01-01

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

  20. Lectin agglutination of thermophilic Campylobacter species.

    PubMed

    Corbel, M J; Gill, K P

    1987-10-01

    Agglutination tests with lectins indicated differences in the surface composition of strains of the thermophilic (optimum temperature 42 degrees C) Campylobacter species C. coli, C. faecalis, C. hyointestinalis, C. jejuni and C. laridis. All strains examined were agglutinated by the protein-reactive agglutinins of Mangifera indica (mango) and Persea americana (avocado) and a large proportion was also agglutinated by the carbohydrate-reactive lectins of Canavalia ensiformis (Jack bean) and Triticum vulgaris (wheat germ). Reactions with other lectins varied widely between strains, even of the same species and serotype. Lectin agglutination may be useful as a supplementary procedure for characterizing individual Campylobacter isolates for epidemiological purposes. PMID:3439012

  1. Complement in skin diseases.

    PubMed

    Kotnik, V

    2011-01-01

    Complement is one of the most important mechanisms of natural resistance preventing infections in humans and animals. It is actively involved in the pathogenesis of several diseases, including skin diseases, characterized by the presence of autoantibodies, foreign microorganisms, altered tissue cells, and the presence of mannan. Complement is intended to kill invading microorganisms but it can also destroy the organism's own damaged or altered cells. It is characterized by vigorous activity and is also potentially harmful for the host if triggered in its own body. This review discusses the significance of complement activation for emerging skin diseases and highlights the importance of serological laboratory tests for the detection of complement system activity alterations in skin diseases such as pemphigus vulgaris, bullous pemphigoid, herpes gestationis, dermatitis herpetiformis, porphyria, urticaria, angioedema, cutaneous vasculitis, systemic lupus erythematosus, partial lipodystrophy, lichen planus, xeroderma pigmentosum, psoriasis, and recurrent cutaneous infections. Finally, we draw attention to the current potential for treating these diseases with complement inhibitors. PMID:21879199

  2. Mechanism and function of complement factor H 

    E-print Network

    McIntosh, Nicola

    2014-06-28

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

  3. A novel CRIg-targeted complement inhibitor protects cells from complement damage.

    PubMed

    Qiao, Qian; Teng, Xiaoyan; Wang, Na; Lu, Renquan; Guo, Lin; Zhang, Xin; Du, Yiqun; Wang, Wenjuan; Chen, Suning; Wu, Qian; He, Guangsheng; Wang, Yingwei; Hu, Weiguo

    2014-11-01

    The inappropriate activation of complement may contribute to various immune diseases. The alternative pathway (AP) predominates during complement activation regardless of the initiating pathways. Hence, the main AP regulator factor H (FH) holds great potential as an attractive therapeutic intervention. In addition, complement receptor of the immunoglobulin superfamily (CRIg) has been demonstrated to inhibit AP and, more notably, still specifically binds to C3b/iC3b. We thus developed novel CRIg-targeted complement inhibitors by connecting the functional domains of CRIg and FH, which we termed CRIg-FH and CRIg-L-FH. CRIg-L-FH, slightly more potent than CRIg-FH, considerably inhibited both AP- and also classical pathway (CP)-mediated hemolysis and successfully eliminated the deposition of C3b/iC3b. Kinetic analysis further revealed that the binding affinity constant (KD) of CRIg/FH was in the micromolar range, consistent with its long-lasting binding to complement-attacked cells. CRIg-L-FH efficiently protected aberrant erythrocytes of patients with paroxysmal nocturnal hemoglobinuria (PNH) from AP- and CP-mediated complement damage (IC50 was 22.43 and 64.69 nM, respectively). Moreover, CRIg-L-FH was found to inhibit complement activation induced by the anti-Thy1 antibody in a mesangioproliferative glomerulonephritis (MPGN) rat model. Hence, CRIg-L-FH protects glomerular mesangial cells (GMCs) from complement-mediated injury and proliferative lesions. These findings strongly suggest that CRIg/FH is a potential therapeutic drug candidate for a range of complement-mediated diseases. PMID:25114177

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

    E-print Network

    Hocking, Henry G.

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

  5. Lectin binding patterns in amphibian epidermis.

    PubMed

    Villalba, J M; Navas, P; Garcia-Herdugo, G

    1987-01-01

    A battery of 6 different horseradish peroxidase conjugated lectins has been employed for structural localization of glycoconjugates in amphibian epidermis. Lens culinaris (LCA) lectin stained the basal membrane and gave no significant reaction on the epidermal layers. Canavlia ensiformis (Con A) and Griffonia simplicifolia II (GS II) lectins bound the keratinocyte cytoplasm and the basal membrane as well. Ulex europaeus I (UEA I) lectin had only reactivity with flask cells. Griffonia simplifolia I (GS I) and Glycine max (SBA) lectins preferentially bound the cell membranes of keratinocytes, being the intensity of the staining gradually increasing from the stratum spinosum to the stratum granulosum. These results show that UEA I, GS I, and SBA are good markers to distinguish different cell types and the degree of keratinocytes differentiation. PMID:3105215

  6. Effect of chum salmon egg lectin on tight junctions in caco-2 cell monolayers.

    PubMed

    Nemoto, Ryo; Yamamoto, Shintaro; Ogawa, Tomohisa; Naude, Ryno; Muramoto, Koji

    2015-01-01

    The effect of a chum salmon egg lectin (CSL3) on tight junction (TJ) of Caco-2 cell monolayers was investigated. The lectin opened TJ as indicated by the decrease of the transepithelial electrical resistance (TER) value and the increase of the permeation of lucifer yellow, which is transported via the TJ-mediated paracellular pathway. The effects of CSL3 were inhibited by the addition of 10 mM L-rhamnose or D-galactose which were specific sugars for CSL3. The lectin increased the intracellular Ca2+ of Caco-2 cell monolayers, that could be inhibited by the addition of L-rhamnose. The fluorescence immunostaining of ?-actin in Caco-2 cell monolayers revealed that the cytoskeleton was changed by the CSL3 treatment, suggesting that CSL3 depolymerized ?-actin to cause reversible TJ structural and functional disruption. Although Japanese jack bean lectin and wheat germ lectin showed similar effects in the decrease of the TER values and the increase of the intracellular Ca2+, they could not be inhibited by the same concentrations of simple sugars, such as D-glucose and N-acetyl-D-glucosamine. PMID:25951005

  7. The X-ray Crystal Structure of Mannose-binding Lectin-associated Serine Proteinase-3 Reveals the Structural Basis for Enzyme Inactivity Associated with the Carnevale, Mingarelli, Malpuech, and Michels (3MC) Syndrome*

    PubMed Central

    Yongqing, Tang; Wilmann, Pascal G.; Reeve, Shane B.; Coetzer, Theresa H.; Smith, A. Ian; Whisstock, James C.; Pike, Robert N.; Wijeyewickrema, Lakshmi C.

    2013-01-01

    The mannose-binding lectin associated-protease-3 (MASP-3) is a member of the lectin pathway of the complement system, a key component of human innate and active immunity. Mutations in MASP-3 have recently been found to be associated with Carnevale, Mingarelli, Malpuech, and Michels (3MC) syndrome, a severe developmental disorder manifested by cleft palate, intellectual disability, and skeletal abnormalities. However, the molecular basis for MASP-3 function remains to be understood. Here we characterize the substrate specificity of MASP-3 by screening against a combinatorial peptide substrate library. Through this approach, we successfully identified a peptide substrate that was 20-fold more efficiently cleaved than any other identified to date. Furthermore, we demonstrated that mutant forms of the enzyme associated with 3MC syndrome were completely inactive against this substrate. To address the structural basis for this defect, we determined the 2.6-? structure of the zymogen form of the G666E mutant of MASP-3. These data reveal that the mutation disrupts the active site and perturbs the position of the catalytic serine residue. Together, these insights into the function of MASP-3 reveal how a mutation in this enzyme causes it to be inactive and thus contribute to the 3MC syndrome. PMID:23792966

  8. Studies on Complement

    E-print Network

    Sherwood, Noble P.

    1921-01-01

    KU ScholarWorks | The University of Kansas Pre-1923 Dissertations and Theses Collection Studies on Complement 1921 by Noble P. Sherwood This work was digitized by the Scholarly Communications program staff in the KU Libraries’ Center for Digital... Scholarship. http://kuscholarworks.ku.edu Submitted to the Graduate Faculty and the Board of Administration of the University of Kansas in Partial Fulfiliment of the Requirements for the Degree of Doctor of Philosophy. w r* L I J STUDIES OH COMPLEMENT...

  9. A new type of lectin discovered in a fish, flathead (Platycephalus indicus), suggests an alternative functional role for mammalian plasma kallikrein*

    PubMed Central

    Tsutsui, Shigeyuki; Okamoto, Masaki; Ono, Miyuki; Suetake, Hiroaki; Kikuchi, Kiyoshi; Nakamura, Osamu; Suzuki, Yuzuru; Watanabe, Tasuku

    2011-01-01

    A skin mucus lectin exhibiting a homodimeric structure and an S–S bond between subunits of ?40 kDa was purified from flathead Platycephalus indicus (Scorpaeniformes). This lectin, named FHL (FlatHead Lectin), exhibited mannose-specific activity in a Ca2+-dependent manner. Although FHL showed no homology to any previously reported lectins, it did exhibit ?20% identity to previously discovered plasma kallikreins and coagulation factor XIs of mammals and Xenopus laevis. These known proteins are serine proteases and play pivotal roles in the kinin-generating system or the blood coagulation pathway. However, alignment analysis revealed that while FHL lacked a serine protease domain, it was homologous to the heavy-chain domain of plasma kallikreins and coagulation factor XI therefore suggesting that FHL is not an enzyme but rather a novel animal lectin. On the basis of this finding, we investigated the lectin activity of human plasma kallikrein and revealed that it could indeed act as a lectin. Other genes homologous to FHL were also found in the genome databases of some fish species, but not in mammals. In contrast, plasma kallikreins and coagulation factor XI have yet to be identified in fish. The present findings suggest that these mammalian enzymes may have originally emerged as a lectin and may have evolved into molecules with protease activity after separation from common ancestors. PMID:21613239

  10. Innate immune lectins kill bacteria expressing blood group antigen

    PubMed Central

    Stowell, Sean R.; Arthur, Connie M.; Dias-Baruffi, Marcelo; Rodrigues, Lilian C.; Gourdine, Jean-Philippe; Heimburg-Molinaro, Jamie; Ju, Tongzhong; Molinaro, Ross J.; Rivera-Marrero, Carlos; Xia, Baoyun; Smith, David F.; Cummings, Richard D.

    2010-01-01

    The expression of ABO(H) blood group antigens causes deletion of cells that generate self anti-blood group antibodies, but this deletion limits adaptive immunity toward pathogens bearing cognate blood group antigens. To explore potential defense mechanisms against these pathogens, given such limitations in adaptive immunity, we screened for innate proteins that could recognize human blood group antigens. Here we report that two innate immune lectins, galectins-4 and -8, which are expressed in the intestinal tract, recognize and kill human blood group antigen-expressing E. coli, while failing to alter viability of other E. coli strains or other gram-negative or gram-positive organisms both in vitro and in vivo. Killing by both galectins-4 and -8 resides within their C-terminal domains, occurs rapidly and independently of complement, and is accompanied by disruption of membrane integrity. These results demonstrate that innate defense lectins can provide immunity against pathogens that display blood group self-antigens on their surface. PMID:20154696

  11. Lectins from Griffonia simplicifolia seeds

    Microsoft Academic Search

    Irwin J. Goldstein

    1983-01-01

    The physical-chemical and carbohydrate binding specificity ofGriffonia simplicifolia I (GS I) isolectins, one of the 4 lectins isolated fromGriffonia simplicifolia seeds, are described.\\u000a \\u000a Association constants for the binding of methyl ?- and ?-D-galactopyranoside and methyl 2-acetamido-2-deoxy-?-D-galactopyranoside\\u000a to the A4, A2 B2 and B4 isolectins are reported.\\u000a \\u000a \\u000a \\u000a Precipitation reactions of theGriffonia simplicifolia isolectins with guaran and type B blood group substance

  12. Molecular and expression analysis of complement component C5 in the nurse shark (Ginglymostoma cirratum) and its predicted functional role.

    PubMed

    Graham, Matthew; Shin, Dong-Ho; Smith, Sylvia L

    2009-07-01

    We present the complete cDNA sequence of shark (Ginglymostoma cirratum) pro-C5 and its molecular characterization with a descriptive analysis of the structural elements necessary for its potential functional role as a potent mediator of inflammation (fragment C5a) and initiator molecule (fragment C5b) for the assembly of the membrane attack complex (MAC) upon activation by C5 convertase. In mammals the three complement activation cascades, the classical, alternative and lectin pathways, converge at the activation of C3, a pivotal complement protein. It is, however, the subsequent activation of the next complement component, C5, which is the focal point at which the initiation of the terminal lytic pathway takes place and involves the stepwise assembly of the MAC. The effector cytolytic function of complement occurs with the insertion of MAC into target membranes causing dough-nut like holes and cell leakage. The lytic activity of shark complement results in structurally similar holes in target membranes suggesting the assembly of a shark MAC that likely involves a functional analogue of C5. The composition of shark MAC remains unresolved and to date conclusive evidence has been lacking for shark C5. The gene has not been cloned nor has the serum protein been characterized for any elasmobranch species. This report is the first to confirm the presence of C5 homologue in the shark. GcC5 is remarkably similar to human C5 in overall structure and domain arrangement. The GcC5 cDNA measured 5160-bp with 5' and 3' UTRs of 35 bp and 79 bp, respectively. Structural analysis of the derived protein sequence predicts a molecule that is a two-chain structure which lacks a thiolester bond and contains a C5 convertase cleavage site indicating that activation will generate two peptides, akin to C5b and C5a. The putative GcC5 molecule also contains the C-terminal C345C/Netrin module that characterizes C3, C4 and C5. Multiple alignment of deduced amino acid sequences shows that GcC5 shares more amino acid identities/similarities with mammals than that with bony fish. We conclude that at the time of emergence of sharks the elaborate mosaic structure of C5 had already evolved. PMID:19410004

  13. Spectral characters of lectin saccharide interaction

    NASA Astrophysics Data System (ADS)

    Wang, Deyu; Jiang, Duxiao; Yuan, Chunwei

    1999-09-01

    In this paper we report attempts to directly detect the interaction behavior between erythrocyte and lectin concanavalin a (Con A) as well as phaseolus vulgaris (PHA) on the polystyrene film surface. In the procedure, an optical transducer based reflectance interferometry was set up and used to detect the film thickness change during the lectin adsorption and lectin- erythrocyte interaction. The specific interactions among Con A, PHA and erythrocyte were obtained. The solubility monosaccharide inhibition test confirmed that there is affinity between (alpha) - D-mannose and Con A.

  14. ECEMA 1993 Language complements 7.1 Language complements

    E-print Network

    Aboulhamid, El Mostapha

    © ECEMA 1993 Language complements 7.1 SECTION 7 Language complements Page Alias 7.2 User defined.15 Configuration 7.19 © ECEMA 1993 Language complements 7.2 Alias declaration alias identifier : subtype through different aliases. #12;© ECEMA 1993 Language complements 7.3 Predefined attributes Scalar

  15. Lectins as Endocytic Ligands: An Assessment of Lectin Binding and Uptake to Rabbit Conjunctival Epithelial Cells

    Microsoft Academic Search

    Mohamed Qaddoumi; Vincent H. L. Lee

    2004-01-01

    Purpose. To investigate the binding and uptake pattern of three plant lectins in rabbit conjunctival epithelial cells (RCECs) with respect to their potential for enhancing cellular macromolecular uptake.

  16. Cloning and characterization of two different L-type lectin genes from the Chinese mitten crab Eriocheir sinensis.

    PubMed

    Huang, Ying; Tan, Jing-Min; Wang, Zheng; Yin, Shao-Wu; Huang, Xin; Wang, Wen; Ren, Qian

    2014-10-01

    L-type lectins contain a leguminous lectin domain and bind to high-mannose type oligosaccharides. In the secretory pathway, L-type lectins play crucial functions in the trafficking, sorting, and targeting of maturing glycoproteins. This study identified two novel L-type lectins, designated as EsERGIC-53 and EsVIP36, from the Chinese mitten crab Eriocheir sinensis. The complete nucleotide sequence of ERGIC-53 cDNA was 1955 bp, containing a 1506 bp open reading frame (ORF) encoding a putative protein of 501 deduced amino acids. The full-length cDNA of VIP36 was 3474 bp with a 984 bp ORF encoding a 327-amino acid peptide. The deduced ERGIC-53 and VIP36 proteins contained a putative signal peptide and an L-type lectin-like domain. Phylogenetic analysis showed that ERGIC-53 and VIP36 belonged to different clades of L-type lectin family. Reverse transcription PCR showed that ERGIC-53 and VIP36 were expressed in all tested tissues. Quantitative real-time RT-PCR analysis revealed that ERGIC-53 and VIP36 transcripts in hepatopancreas were significantly induced at various time points after infection with lipopolysaccharide (LPS), peptidoglycan (PGN), Staphylococcus aureus, Vibrio parahaemolyticus, and Aeromonas hydrophila. A bacterium-binding experiment showed that both ERGIC-53 and VIP36 could bind to different microbes. Sugar binding assay revealed that these lectins could also bind to the glycoconjugates of bacteria surface, such as LPS, PGN, d-Mannose, and N-Acetyl-d-mannosamine. Moreover, these two L-type lectins agglutinated bacteria in a calcium-dependent manner, and both exerted the ability of facilitating the clearance of injected bacteria V. parahaemolyticus in the crab. Our results suggested that ERGIC-53 and VIP36 functioned as pattern recognition receptors in the immune system of E. sinensis. PMID:24796868

  17. Lectin histochemistry in the aged dog brain

    Microsoft Academic Search

    Wijit Kiatipattanasakul; Hiroyuki Nakayama; Shin-ichiro Nakamura; Kunio Doi

    1998-01-01

    Formalin-fixed and paraffin-embedded canine brains were examined histochemically using 15 selected lectins. Concanavalin\\u000a A (Con A), Lens culinaris agglutinin, Lycopersicon esculentum agglutinin (LEL) and Limulus polyphemus agglutinin (LPA) labeled neurons in an age-dependent manner. These and some other lectins [Dolichos biflorus agglutinin (DBA), Vicia villosa agglutinin (VVA), Ricinus communis agglutinin 120 (RCA-I), Bandeiraea simplicifolia agglutinin (BSL-I), and Phaseolus vulagaris agglutinin-L

  18. Lectin from the trunk of Sophora japonica

    Microsoft Academic Search

    K. Baba; H. Kuroda

    1989-01-01

    Lectin was purified from the bark of Sophora japonica trunk by a simple method, affinity chromatography on acid-treated agarose; the yield was about 27% of the total sap proteins. Its molecular weight was 135,000±5,000 shown by using gel filtration, similar to that of the seed lectin of this species. When analyzed by using polyacrylamide gel electrophoresis (PAGE) under acidic and

  19. A new lectin from tulip ( Tulipa ) bulbs

    Microsoft Academic Search

    B. P. A. Cammue; B. Peeters; W. J. Peumans

    1986-01-01

    A lectin was isolated from tulip (Tulipa) bulbs by affinity chromatography on fetuin-agarose and partially characterized. The tulip lectin is a tetrameric protein composed of four identical subunits of Mr 28 000, which are not held together by disulphide bonds. It is not glycosylated and has an amino-acid composition typified by a high content of asparagine-aspartic acid, leucine, glycine and

  20. Neutrophil recruitment in skin window chambers--activation by complement.

    PubMed

    Elmgreen, J

    1985-06-01

    Complement was studied in skin window chambers, a human model of neutrophil recruitment in acute aseptic inflammation. Autologous plasma activated by the alternative pathway served as attractant; control chambers were filled with a balanced salt solution or with non-activated plasma samples. Neutrophil accumulation during a 24-hour period was consistently enhanced by activated complement in all of 15 healthy volunteers. Control chambers showed negligible cell counts. Reference assays revealed 1) consumption of the centrally placed complement component, C3, 2) generation of chemotactic activity as assessed in Boyden chambers by the standard complement activation procedure. Simultaneously obtained responses to activated complement in skin window chambers and in the Boyden assay of chemotaxis showed a highly significant, positive correlation. Our results demonstrate that the biological capacity of complement includes stimulation of neutrophil migration during simulated in vivo conditions and thus extends previous observations in animals. PMID:4036613

  1. Lectin histochemistry in the aged dog brain.

    PubMed

    Kiatipattanasakul, W; Nakayama, H; Nakamura, S; Doi, K

    1998-03-01

    Formalin-fixed and paraffin-embedded canine brains were examined histochemically using 15 selected lectins. Concanavalin A (Con A), Lens culinaris agglutinin, Lycopersicon esculentum agglutinin (LEL) and Limulus polyphemus agglutinin (LPA) labeled neurons in an age-dependent manner. These and some other lectins [Dolichos biflorus agglutinin (DBA), Vicia villosa agglutinin (VVA), Ricinus communis agglutinin 120 (RCA-I), Bandeiraea simplicifolia agglutinin (BSL-I), and Phaseolus vulagaris agglutinin-L (PHA-L)] also age-dependently labeled glial cells. These results indicate that monosaccharide composition and biochemical metabolism in brain cells change with age and that these lectins may be useful as histochemical markers for investigating senile changes in the canine brain. However, no significant correlation was found between ApopTag-positive and lectin-positive cells. Amyloid plaques were positive for Con A, DBA, Glycine maximus agglutinin (SBA), LEL, PHA-L, Limax flavus agglutinin (LFA) and VVA. Among these lectins, VVA, SBA and LFA intensely stained amyloid both in blood vessel walls and senile plaque cores. Therefore, the sugar residues recognized by these lectins likely play specific roles in beta-amyloid deposition in the aged dog brain. PMID:9542591

  2. Lectin staining of cultured CNS microglia.

    PubMed

    Colton, C A; Abel, C; Patchett, J; Keri, J; Yao, J

    1992-04-01

    Carbohydrate binding proteins, known as lectins, bind to specific sugar groups on most membranes. We used fluorescent and light microscopy to study the interaction of various lectins with the membranes of microglia cultured from neonatal rat or fetal mouse cerebral cortices. Microglia stained intensely with GS-1, RCA, WGA, and ConA and slightly with DBA, UEA, BPA, and SBA. No staining was seen with GS-2, MPA, or PNA. Staining was specific for microglia in the mixed glial cultures and was dose dependent. In addition, microglial lectin binding could be reduced or blocked by competitive inhibition using specific sugars. Treatment of the microglia with agents such as dimethylsulfoxide (DMSO), interleukin-1 (IL-1), interferon (IFN), or lipopolysaccharide (LPS) did not eliminate lectin staining, although the degree of staining was altered. Positive staining of the microglia was also associated with a functional change for at least one lectin, i.e., ConA. Superoxide anion production by microglia was increased in the presence of ConA. Overall, binding of the lectins GS-1, RCA, WGA, and ConA can be used as an identifying tool for microglia in glial cultures, but intensity of staining varies depending on their functional state. PMID:1372634

  3. Quantitative determination of lectins in mistletoe preparations.

    PubMed

    Jäggy, C; Musielski, H; Urech, K; Schaller, G

    1995-08-01

    Assay of lectins in mistletoe preparations was based on an improved and validated version of ELLA (enzyme-linked lectin assay) to meet the requirements given in the guidelines for drug tests. The monoclonal antibody used has more than 90% cross reactivity with the three known mistletoe lectins, so that total lectin content is determined with much greater accuracy. With the detection and quantitative analysis limit below 5 ng/ml and a linear measuring range of 5-50 ng/ml, dosages in therapeutic range can be assayed. Tests to establish the accuracy of the analytical method showed that up to 26% of lectin activity is suppressed by other constituents of the extract, so that the recovery must be taken into account. The recovery increases following ultrafiltration to remove low-molecular constituents. Analysis for precision gave a variation coefficient of < or = 7.7% and a confidence interval < or = 5.7% (p = 0.05) for total lectin concentrations of approx. 250 ng/ml. This level of precision, which is good for an immunologic assay, makes it possible to standardize mistletoe preparations. PMID:7575759

  4. The Mel 14 antibody binds to the lectin domain of the murine peripheral lymph node homing receptor

    Microsoft Academic Search

    Benjamin R. Bowen; Christopher Fennie; Laurence A. Lasky

    1990-01-01

    Murine and human leukocytes express sur- face glycoproteins, termed homing receptors (HRs), containing lectin-like, EGF-like (egf), and complement binding-like domains, that apparently endow these cells with the ability to home to peripheral lymph nodes (pin's) by virtue of an adhesive interaction with the pin postcapillary venule endothelium. The murine pin HR was initially characterized with a rat monoclo- nal antibody,

  5. Complement inhibition: a promising concept for cancer treatment

    PubMed Central

    Pio, Ruben; Ajona, Daniel; Lambris, John D.

    2013-01-01

    For decades, complement has been recognized as an effector arm of the immune system that contributes to the destruction of tumor cells. In fact, many therapeutic strategies have been proposed that are based on the intensification of complement-mediated responses against tumors. However, recent studies have challenged this paradigm by demonstrating a tumor-promoting role for complement. Cancer cells seem to be able to establish a convenient balance between complement activation and inhibition, taking advantage of complement initiation without suffering its deleterious effects. Complement activation may support chronic inflammation, promote an immunosuppressive microenvironment, induce angiogenesis, and activate cancer-related signaling pathways. In this context, inhibition of complement activation would be a therapeutic option for treating cancer. This concept is relatively novel and deserves closer attention. In this paper, we will summarize the mechanisms of complement activation on cancer cells, the cancer-promoting effect of complement initiation, and the rationale behind the use of complement inhibition as a therapeutic strategy against cancer. PMID:23706991

  6. Complement-Mediated Microglial Clearance of Developing Retinal Ganglion Cell Axons

    E-print Network

    Boulanger, Lisa

    Complement-Mediated Microglial Clearance of Developing Retinal Ganglion Cell Axons Carolyn M. Tyler class I (MHCI) and complement cascade (C1q and C3) are expressed in the developing brain). For the complement system, however, the final molecular signaling pathways and cellular effectors involved

  7. A hemolytic assay for the estimation of functional mannose-binding lectin levels in human serum

    Microsoft Academic Search

    Saskia Kuipers; Piet C. Aerts; Anders G. Sjoholm; Theo Harmsen; Hans van Dijk

    2002-01-01

    A simple assay was developed to estimate functional mannose-binding lectin (MBL) levels in serum based on the principle of yeast-induced bystander lysis of chicken erythrocytes (ChE). The assay is sensitive to inhibition by ethylene glycol bis-(?-aminoethyl ether)-N,N,N?,N?-tetraacetic acid (EGTA) (which allows alternative pathway activation), ethylene diamine tetraacetic acid (EDTA), mannose, N-acetylglucosamine and C1 esterase inhibitor (C1-INH), whereas it was not

  8. Cyclosporine Induces Endothelial Cell Release of Complement-Activating Microparticles

    PubMed Central

    Renner, Brandon; Klawitter, Jelena; Goldberg, Ryan; McCullough, James W.; Ferreira, Viviana P.; Cooper, James E.; Christians, Uwe

    2013-01-01

    Defective control of the alternative pathway of complement is an important risk factor for several renal diseases, including atypical hemolytic uremic syndrome. Infections, drugs, pregnancy, and hemodynamic insults can trigger episodes of atypical hemolytic uremic syndrome in susceptible patients. Although the mechanisms linking these clinical events with disease flares are unknown, recent work has revealed that each of these clinical conditions causes cells to release microparticles. We hypothesized that microparticles released from injured endothelial cells promote intrarenal complement activation. Calcineurin inhibitors cause vascular and renal injury and can trigger hemolytic uremic syndrome. Here, we show that endothelial cells exposed to cyclosporine in vitro and in vivo release microparticles that activate the alternative pathway of complement. Cyclosporine-induced microparticles caused injury to bystander endothelial cells and are associated with complement-mediated injury of the kidneys and vasculature in cyclosporine-treated mice. Cyclosporine-induced microparticles did not bind factor H, an alternative pathway regulatory protein present in plasma, explaining their complement-activating phenotype. Finally, we found that in renal transplant patients, the number of endothelial microparticles in plasma increases 2 weeks after starting tacrolimus, and treatment with tacrolimus associated with increased C3 deposition on endothelial microparticles in the plasma of some patients. These results suggest that injury-associated release of endothelial microparticles is an important mechanism by which systemic insults trigger intravascular complement activation and complement-dependent renal diseases. PMID:24092930

  9. Complement activation promotes muscle inflammation during modified muscle use

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  10. Biofilm Formation Avoids Complement Immunity and Phagocytosis of Streptococcus pneumoniae

    PubMed Central

    Domenech, Mirian; Ramos-Sevillano, Elisa; García, Ernesto

    2013-01-01

    Streptococcus pneumoniae is a frequent member of the microbiota of the human nasopharynx. Colonization of the nasopharyngeal tract is a first and necessary step in the infectious process and often involves the formation of sessile microbial communities by this human pathogen. The ability to grow and persist as biofilms is an advantage for many microorganisms, because biofilm-grown bacteria show reduced susceptibility to antimicrobial agents and hinder recognition by the immune system. The extent of host protection against biofilm-related pneumococcal disease has not been determined yet. Using pneumococcal strains growing as planktonic cultures or as biofilms, we have investigated the recognition of S. pneumoniae by the complement system and its interactions with human neutrophils. Deposition of C3b, the key complement component, was impaired on S. pneumoniae biofilms. In addition, binding of C-reactive protein and the complement component C1q to the pneumococcal surface was reduced in biofilm bacteria, demonstrating that pneumococcal biofilms avoid the activation of the classical complement pathway. In addition, recruitment of factor H, the downregulator of the alternative pathway, was enhanced by S. pneumoniae growing as biofilms. Our results also show that biofilm formation diverts the alternative complement pathway activation by a PspC-mediated mechanism. Furthermore, phagocytosis of pneumococcal biofilms was also impaired. The present study confirms that biofilm formation in S. pneumoniae is an efficient means of evading both the classical and the PspC-dependent alternative complement pathways the host immune system. PMID:23649097

  11. Complements de programmation Precision et erreurs Complements de programmation

    E-print Network

    Menichi, Luc

    Compl´ements de programmation Pr´ecision et erreurs Compl´ements de programmation Pr´ecision et erreurs D. Schaub 7 f´evrier 2012 D. Schaub Compl´ements de programmation Pr´ecision et erreurs #12;Compl´ements´etiques Erreurs d'arrondi sur somme/produit Calculs r´ecurrents et it´eratifs D. Schaub Compl´ements de

  12. Disabling complement regulatory activities of vaccinia virus complement control protein reduces vaccinia virus pathogenicity.

    PubMed

    Bernet, John; Ahmad, Muzammil; Mullick, Jayati; Panse, Yogesh; Singh, Akhilesh K; Parab, Pradeep B; Sahu, Arvind

    2011-10-01

    Poxviruses encode a repertoire of immunomodulatory proteins to thwart the host immune system. One among this array is a homolog of the host complement regulatory proteins that is conserved in various poxviruses including vaccinia (VACV) and variola. The vaccinia virus complement control protein (VCP), which inhibits complement by decaying the classical pathway C3-convertase (decay-accelerating activity), and by supporting inactivation of C3b and C4b by serine protease factor I (cofactor activity), was shown to play a role in viral pathogenesis. However, the role its individual complement regulatory activities impart in pathogenesis, have not yet been elucidated. Here, we have generated monoclonal antibodies (mAbs) that block the VCP functions and utilized them to evaluate the relative contribution of complement regulatory activities of VCP in viral pathogenesis by employing a rabbit intradermal model for VACV infection. Targeting VCP by mAbs that inhibited the decay-accelerating activity as well as cofactor activity of VCP or primarily the cofactor activity of VCP, by injecting them at the site of infection, significantly reduced VACV lesion size. This reduction however was not pronounced when VCP was targeted by a mAb that inhibited only the decay-accelerating activity. Further, the reduction in lesion size by mAbs was reversed when host complement was depleted by injecting cobra venom factor. Thus, our results suggest that targeting VCP by antibodies reduces VACV pathogenicity and that principally the cofactor activity of VCP appears to contribute to the virulence. PMID:21803094

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

    E-print Network

    Pechtl, Isabell C.

    2010-01-01

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

  14. [Change of the wheat lectin activity and degree of its interaction with different components of compositions of lectin nature].

    PubMed

    Kyrychenko, O V

    2006-01-01

    The wheat lectin hemagglutination activity and degree of its interaction with the bacterium Azotobacter chroococcum T79 and aminosaccharide N-acetyl-D-glucosamin hapten of wheat lectin was studied in laboratory experiments with the purpose of creation of biologic activity compositions of lectin nature for plant growing. It was shown that plant-bacterial compositions encloses the "bacteria+lectin" complex, free lectin and bacterial cells. The addition of aminosaccharide N-acetyl-D-glucosamin to wheat lectin, to the bacterial culture and plant-bacterial composition decreases its hemagglutination activity. The possibility of creation of new complexes in this compositions effected by hapten "lectin+hapten", "lectin+hapten+bacteria", "bacteria+hapten" is under discussion. PMID:17494326

  15. Selective Inhibition of WSN Influenza Virus Haemolysis by Pea Lectin

    Microsoft Academic Search

    DAVID L. KRAH; PURNELL W. CHOPPIN

    1988-01-01

    SUMMARY The capacity of lectins to inhibit viral haemolysis of chicken erythrocytes was tested, to evaluate the role of carbohydrate in the fusion reaction. Pretreatment of cells with pea lectin provided a 70 ~ to 85 ~ haemolysis inhibition with WSN influenza virus, but only 109\\/oo to 14~ with PR8 influenza virus. Pea lectin did not detectably bind to virus,

  16. Prevalence, biological activity and genetic manipulation of lectins in foods

    Microsoft Academic Search

    W. J. Peumans; E. J. M. Van Damme

    1996-01-01

    Many food plants contain proteins that are usually referred to as lectins on the basis of their specific carbohydrate-binding properties. Some of these lectins protect the plant against predatory invertebrates and higher animals, and they may also be harmful to humans. Therefore, the presence of lectins in food plants and foodstuffs is an important issue in food science. Although the

  17. 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

  18. COMPLEMENTABLY UNIVERSAL BANACH SPACES, II

    E-print Network

    Johnson, William B.

    COMPLEMENTABLY UNIVERSAL BANACH SPACES, II. If a Banach space X is complementably universal for all subspaces of c0 which have the bounded space in B is isomorphic to a complemented subspace of U, i.e. if for every B 2 B, the identity on B

  19. ALEXANDER INVARIANTS OF HYPERSURFACE COMPLEMENTS

    E-print Network

    Plotkin, Joshua B.

    ALEXANDER INVARIANTS OF HYPERSURFACE COMPLEMENTS Laurentiu G. Maxim A Dissertation in Mathematics INVARIANTS OF HYPERSURFACE COMPLEMENTS Laurentiu G. Maxim Julius Shaneson, Advisor We study Alexander invariants associated to complements of complex hypersur- faces. We show that for a hypersurface V with non

  20. Comprehensive lectin histochemistry of normal and neoplastic human choroid plexus cells: alternation of lectin-binding patterns through neoplastic transformation

    Microsoft Academic Search

    Y. Kaneko; T. Iwaki; T. Matsushima; M. Fukui

    1991-01-01

    Lectin histochemistry of the normal and neoplastic human choroid plexus cells [six choroid plexus papillomas (CPPs) and three choroid plexus carcinomas (CPCs)] was performed using eight representative lectins to study the development of sugar chain structures and also to determine whether lectins were useful for a histopathological diagnosis of choroid plexus neoplasms (CPNs). The normal choroid plexus cells reacted with

  1. Complement and HIV-I infection/ HIV-associated neurocognitive disorders

    PubMed Central

    Liu, Fengming; Dai, Shen; Gordon, Jennifer; Qin, Xuebin

    2014-01-01

    The various neurological complications associated with HIV-1 infection, specifically HIV-associated neurocognitive disorders (HAND) persist as a major public health burden worldwide. Despite the widespread use of anti-retroviral therapy, the prevalence of HAND is significantly high. HAND results from the direct effects of an HIV-1 infection as well as secondary effects of HIV-1-induced immune reaction and inflammatory response. Complement, a critical mediator of innate and acquired immunity, plays important roles in defeating many viral infections by the formation of a lytic pore or indirectly by opsonization and recruitment of phagocytes. While the role of complement in the pathogenesis of HIV-1 infection and HAND has been previously recognized for over fifteen years, it has been largely underestimated thus far. Complement can be activated through HIV-1 envelope proteins, mannose binding lectins (MBL) and anti-HIV-1 antibodies. Complement not only fights against HIV-1 infection but also enhances HIV-1 infection. Also, HIV-1 can hijack complement regulators such as CD59 and CD55 and can utilize these regulators and factor H to escape from complement attack. Normally, complement levels in brain are much lower than plasma levels and there is no or little complement deposition in brain cells. Interestingly, local production and deposition of complement are dramatically increased in HIV-1-infected brain, indicating that complement may contribute to the pathogenesis of HAND. Here, we review the current understanding of the role of complement in HIV-1 infection and HAND as well as potential therapeutic approaches targeting to the complement system for the treatment and eradications of HIV-1 infection. PMID:24639397

  2. The structure of C2b, a fragment of complement component C2 produced during C3 convertase formation

    PubMed Central

    Krishnan, Vengadesan; Xu, Yuanyuan; Macon, Kevin; Volanakis, John E.; Narayana, Sthanam V. L.

    2009-01-01

    The second component of complement (C2) is a multi-domain serine protease that provides catalytic activity for the C3 and C5 convertases of the classical and lectin pathways of human complement. The formation of these convertases requires the Mg2+-dependent binding of C2 to C4b and the subsequent cleavage of C2 by C1s or MASP2, respectively. The crystal structure of full-length C2 is not yet available, although the structure of its C-terminal catalytic segment C2a has been determined. The crystal structure of the N-terminal segment C2b of C2 determined to 1.8?Ĺ resolution presented here reveals the arrangement of its three CCP domains. The domains are arranged differently compared with most other CCP-domain assemblies, but their arrangement is similar to that found in the Ba part of the full-length factor B structure. The crystal structures of C2a, C2b and full-length factor B are used to generate a model for C2 and a discussion of the domain association and possible interactions with C4b during formation of the C4b–C2 complex is presented. The results of this study also suggest that upon cleavage by C1s, C2a domains undergo conformational rotation while bound to C4b and the released C2b domains may remain folded together similar to as observed in the intact protein. PMID:19237749

  3. Carbohydrate specificity of lectins from Boletopsis leucomelas and Aralia cordate.

    PubMed

    Koyama, Yu; Suzuki, Takuji; Odani, Shoji; Nakamura, Sachiko; Kominami, Junko; Hirabayashi, Jun; Isemura, Mamoru

    2006-02-01

    The carbohydrate specificity of three novel lectins, Boletopsis leucomelas lectin (BLL), Aralia cordate lectin (ACL), and Wasabia japonica lectin (WJL), was examined by frontal affinity chromatography using a panel of fluorescently labeled 47 oligosaccharides. The results indicate that BLL recognizes an agalacto structure of the biantennary chain and its bisecting structure. ACL showed strong affinity for triantennary oligosaccharides, but no affinity for tetraantennary structure. WJL showed no appreciable affinity for any of the 47 glycans examined. These lectins with a unique affinity specificity might be useful for examining alterations in the glycan structures of the glycoconjugates in association with development and various diseases. PMID:16495678

  4. 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

  5. Complement activation before, during and after cardiopulmonary bypass.

    PubMed

    Bonser, R S; Dave, J R; John, L; Gademsetty, M K; Carter, P G; Davies, E; Taylor, P; Gaya, H; Lennox, S C; Vergani, D

    1990-01-01

    Plasma levels of the complement parent molecules C3, C4, and factor B and their split products, C3d, C4d, and Ba were measured in 12 patients undergoing cardiopulmonary bypass for coronary artery surgery. Alternative and common complement pathway activation, demonstrated by statistically significant rising levels of Ba (P less than 0.05), and C3d (P less than 0.05) and by elevated Ba:B (P less than 0.05) and C3d:C3 (P less than 0.05) ratios were found before the institution of cardiopulmonary bypass but following heparin administration suggesting that heparin may itself initiate alternative pathway activation. In addition, significant depletion of parent complement components and elevation of split product concentrations was seen during bypass suggesting classical and alternate pathway activation (P less than 0.01). This study clarifies the pathways of complement activation during bypass and presents evidence that heparin administration may initially activate the complement cascade. PMID:2361017

  6. Anesthetic management of living donor liver transplantation for complement factor H deficiency hemolytic uremic syndrome: a case report

    PubMed Central

    Park, Suk-Hee

    2014-01-01

    We experienced a living donor liver transplantation for a 26-month-old girl with complement factor H deficiency. Complement factor H is a plasma protein that regulates the activity of the complement pathway. Complement overactivity induced by complement factor H deficiency is associated with atypical hemolytic uremic syndrome. Liver transplantation can be the proper treatment for this condition. During the liver transplantation of these patients, prevention of the complement overactivation is necessary. Minimizing complement activation, through the use of modalities such as plasma exchange before the surgery and transfusion of fresh frozen plasma throughout the entire perioperative period, may be the key for successful liver transplantation in these patients. PMID:25006375

  7. Animal Lectins as Cell Adhesion Molecules

    Microsoft Academic Search

    H. Kaltner; B. Stierstorfer

    1998-01-01

    Protein-carbohydrate interaction is exploited in cell adhesion mechanisms besides the recognition of peptide motifs. The sugar code thus significantly contributes to the intriguing specificity of cellular selection of binding partners. Focusing on two classes of lectins (selectins and galectins), it is evident that their functionality for mediation of adhesive contacts is becoming increasingly appreciated, as is the integration of this

  8. Complementation system for Helicobacter pylori

    Microsoft Academic Search

    Jinmoon Kim; Sung-Whan Kim; Sungil Jang; D. Scott Merrell; Jeong-Heon Cha

    2011-01-01

    Previously Langford et al. (2006) developed the pIR203C04 complementation system for Helicobacter pylori, which can be used to complement and restore phenotypic effects in H. pylori mutant, and furthermore they used the complementation system in vivo experiments to animals without altering the ability of strain SSI to colonize mice. In their previous study, the pIR203C04\\u000a was able to transform 26695,

  9. Purification and Characterization of Griffonia simplicifolia Leaf Lectins 1

    PubMed Central

    Lamb, Jamie E.; Shibata, Satoaki; Goldstein, Irwin J.

    1983-01-01

    Leaves from mature Griffonia simplicifolia plants were examined for the presence of leaf lectins possessing sugar binding specificities similar to the four known seed lectins (GS-I, GS-II, GS-III, GS-IV). Three (GS-I, -II, -IV) of the four known G. simplicifolia seed lectins were present in the leaves. Leaf G. simplicifolia lectins I and IV were similar to the respective seed lectins. Leaf GS-II, however, was composed of two types of subunits (Mr = 33,000 and 19,000), whereas the seed lectin consists of only one type of subunit (Mr 32,500). Seed and leaf GS-II lectins also had different isoelectric points. All leaf and seed lectins were similar with respect to their hemagglutination and glycoconjugate precipitation properties and all subunits contained covalently bound carbohydrate. Leaf GS-IV appeared slightly under-glycosylated compared to seed GS-IV. The fate of GS-I and GS-II seed lectins in aging cotyledons was investigated. GS-I isolectins usually contain isolectin subtypes associated with each main isolectin. Upon inbibition and germination, these GS-I isolectin subtypes disappeared. Over time, GS-II lectin did not change its disc gel electrophoretic properties. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:16662923

  10. Sensing lectin-glycan interactions using lectin super-microarrays and glycans labeled with dye-doped silica nanoparticles

    PubMed Central

    Wang, Xin; Matei, Elena; Deng, Lingquan; Koharudin, Leonardus; Gronenborn, Angela M.; Ramström, Olof; Yan, Mingdi

    2013-01-01

    A new microarray platform, based on lectin super-microarrays and glycans labeled with dye-doped nanoparticles, has been developed to study glycan-lectin interactions. Glycan ligands were conjugated onto fluorescein-doped silica nanoparticles (FSNPs) using a general photocoupling chemistry to afford FSNP-labeled glycan probes. Lectins were printed on epoxy slides in duplicate sets to generate lectin super-microarrays where multiple assays could be carried out simultaneously in each lectin microarray. Thus, the lectin super-microarray was treated with FSNP-labeled glycans to screen for specific binding pairs. Furthermore, a series of ligand competition assays were carried out on a single lectin super-microarray to generate the dose-response curve for each glycan-lectin pair, from which the apparent affinity constants were obtained. Results showed 4~7 orders of magnitude increase in affinity over the free glycans with the corresponding lectins. Thus, the glycan epitope structures having weaker affinity than the parent glycans could be readily identified and analyzed from the lectin super-microarrays. PMID:23584388

  11. Mesangiocapillary glomerulonephritis associated with meningococcal meningitis, C3 nephritis factor and persistently low complement C3 and C5

    Microsoft Academic Search

    Sally-Anne Hultonl; R. Anthony Risdon; Michael J. Dillon

    1992-01-01

    We report two unusual cases in which mesangiocapillary glomerulonephritis occurred in association with meningococcal infection. C3 nephritic factor, an autoantibody to alternate pathway C3 convertase, was present. Low serum complement C3 and C5 levels were also noted. The depressed complement levels, in conjuction with terminal complement complexes at the upper limit of normal, suggest activation of the early and late

  12. Two cDNAs from the purple sea urchin, Strongylocentrotus purpuratus , encoding mosaic proteins with domains found in factor H, factor I, and complement components C6 and C7

    Microsoft Academic Search

    Keri A. Multerer; L. Courtney Smith

    2004-01-01

    The vertebrate complement system is composed of about 30 serum and cell surface proteins that make up three activation pathways, a lytic pathway, and a set of proteins that regulate complement. Regulatory proteins are required for host protection against autologous complement attack and to control the amplification feedback loop of the alternative pathway. Purple sea urchin, Strongylocentrotus purpuratus, homologues of

  13. Lectin-dependent localization of cell surface sialic acid-binding lectin Siglec-9.

    PubMed

    Ando, Munetoshi; Shoji, Toru; Tu, Wenjie; Higuchi, Hiroshi; Nishijima, Ken-Ichi; Iijima, Shinji

    2015-08-01

    Siglecs are immunoglobulin lectin group proteins that recognize the sialic acid moiety. We previously reported that the expression of Siglec-9 on the macrophage cell line RAW264 markedly enhanced Toll-like receptor (TLR)-induced interleukin (IL)-10 production and inhibited the production of proinflammatory cytokines. In this study, we examined the lectin-dependent anti-inflammatory activities of Siglec-9. IL-10 production was modestly reduced by a mutation that disrupted the lectin activity of Siglec-9, while the reduction in tumor necrosis factor-? was not affected. Membrane fractionation experiments revealed that a part of Siglec-9 resided in the detergent-insoluble microdomain, the so-called lipid raft fraction. The amount of Siglec-9 in the lipid raft fraction rapidly increased following TLR2 stimulation by peptidoglycan and peaked after 3-10 min. This time course was similar to that of TLR2. The double tyrosine mutant in immunoreceptor tyrosine-based inhibitory motifs moved to lipid rafts in a similar manner, while lectin-defective Siglec-9 was not detected in the lipid raft fraction. The production of IL-10 was partially reduced by cholesterol oxidase that disturbed lipid raft organization. Taken together, these results suggest that Siglecs exhibit lectin-dependent changes in cellular localization, which may be partly linked to its control mechanism that increases the production of IL-10. PMID:24449467

  14. Binding of epithelial cells to lectin-coated surfaces

    Microsoft Academic Search

    Stephanie Gordon Phillips; Shiu-Lan Lui; David M. Phillips

    1982-01-01

    Summary  Epithelial cells may relate to their basement membrane substrates via lectin-like interactions. In a model system for study\\u000a of this type of interaction, lectin-coated bacteriological plastic petri dishes were presented as substrates for epithelial\\u000a cell adhesion. Of 21 lectins tested by mixed agglutination against two epithelial cell types, Madin-Darby canine kidney (MDCK),\\u000a and human embryonic kidney cells (HEK), nine gave

  15. 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. .

  16. Reduction of complement activation during bypass by prime manipulation.

    PubMed

    Bonser, R S; Dave, J R; Davies, E T; John, L; Taylor, P; Gaya, H; Lennox, S C; Vergani, D

    1990-02-01

    Complement activation is believed to be of importance in the development of complications arising after cardiopulmonary bypass. The effect on complement activation of priming the extracorporeal circuit with crystalloid alone, crystalloid plus albumin, or crystalloid plus the plasma expander polygeline was assessed in 36 patients undergoing coronary artery operations with cardiopulmonary bypass using a bubble oxygenator. Activation of the alternative and common complement pathways was monitored before, during, and after the bypass period by measuring concentrations of factor B and its fragment Ba and C3 and its fragment C3d. Complement activation occurred in all three groups of patients, with no difference between the crystalloid and crystalloid-albumin groups. In contrast, Ba fragment concentrations were persistently and significantly lower during and after bypass in the polygeline group, denoting reduced complement activation. C3d levels also showed a tendency to be lower in this group. Our results indicate that addition of polygeline to the priming solution reduces complement activation. Because complement activation is associated with morbidity after cardiopulmonary bypass, addition of polygeline to the priming solution may offer an inexpensive method of reducing morbidity after cardiopulmonary bypass. PMID:2306150

  17. Vasodilator effects of Diocleinae lectins from the Canavalia genus.

    PubMed

    Assreuy, Ana Maria Sampaio; Fontenele, Sabrina Rodrigues; Pires, Alana de Freitas; Fernandes, Débora Costa; Rodrigues, Natália Velloso Fontenelle C; Bezerra, Eduardo Henrique Salviano; Moura, Tales Rocha; do Nascimento, Kyria Santiago; Cavada, Benildo Sousa

    2009-12-01

    This study investigated and compared vascular actions of leguminous lectins obtained from the Canavalia genus (Canavalia brasiliensis, Canavalia gladiata, and Canavalia maritima) in the rat models of paw edema and isolated aorta. Paw edema was induced by subcutaneous injection of lectins (0.01-1 mg/kg) in animals pre-treated or not with indomethacin or L-NAME. In isolated aorta, cumulative concentration curves of C. gladiata or C. brasiliensis (1-100 microg/ml) were performed at the contraction plateau induced by phenylephrine or at tissue basal tonus. The mechanism of the lectin relaxant action was investigated by previous addition of L-NAME, indomethacin, or tetraethylammonium. In both models, the lectin domain involvement was evaluated by incubation of lectins with their ligand and non-ligand sugars. The lectins induced paw edema paralleled by protein leakage. The edematogenic activity elicited by C. gladiata and C. brasiliensis involves prostaglandins and nitric oxide (NO), while that of C. maritima occurs without NO interference. C. gladiata and C. brasiliensis elicited aorta relaxation involving NO and prostacyclin, while that of C. gladiata included EDHF. All lectin effects were prevented by their binding sugars. The present study demonstrated important vasodilator effects of different degrees and mechanisms in vivo and in vitro of Canavalia lectins. In vivo, the edematogenic activity was paralleled by plasma exudation, and in vitro, aorta relaxation was strictly dependent on intact endothelium. All effects occurred via interaction with lectin domains and participation of NO and/or prostanoids. PMID:19855960

  18. 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.

  19. C-type lectins and phagocytosis

    PubMed Central

    Kerrigan, Ann M.; Brown, Gordon D.

    2009-01-01

    To recognise and respond to pathogens, germ-line encoded pattern recognition receptors (PRRs) bind to conserved microbial structures and activate host defence systems, including microbial uptake by phagocytosis. Phagocytosis is a complex process that is instrumental in the control of extracellular pathogens, and this activity is mediated by several PRRs, including a number of C-type lectins. While some of these receptors have clearly been shown to mediate or regulate the uptake of pathogens, others are more contentious and are less well understood in terms of their phagocytic potential. Furthermore, very little is known about the underlying phagocytic mechanisms. Here, we review the phagocytic roles of the mannose receptor, Dectin-1, dendritic cell-specific ICAM grabbing non-integrin (DC-SIGN), DCL-1, mannose binding lectin and surfactant proteins A and D. PMID:19261355

  20. Deficiencies and excessive human complement system activation in disorders of multifarious etiology.

    PubMed

    Tichaczek-Goska, Dorota

    2012-01-01

    Complement is an integral part of the immune system protecting the host organism against invasion and proliferation of various microorganisms. It is also involved in the removal of the body's own damaged and altered cells. Activation of the complement system is a very precise process and it is strictly controlled by regulatory proteins present in both plasma and at host cells' surfaces. C3 protein plays a major role in the complement activation and generation of immune responses. Deficiencies of the C3 and other complement components, so-called early and late complement proteins, contribute to the emergence of recurrent bacterial, viral and fungal infections. The low level of mannose-binding lectin is also important. This protein plays a protective role in the early stages of infection and in the control of inflammation. Its deficit is one of the most common reasons for human immunodeficiency, observed in microbial infections as well as in autoimmune diseases such as rheumatoid arthritis. On the other hand, the excessive activation of complement proteins is often discovered to be the reason for many diseases. These include e.g. autoimmune diseases, Alzheimer's syndrome, schizophrenia, atypical hemolytic-uremic syndrome, angioedema, macular degeneration, and Crohn's disease. PMID:23214307

  1. Novel mannose binding lectins from agricultural crops

    Microsoft Academic Search

    Elaine Davidson; Derek Stewart

    2004-01-01

    As part of a large programme [Scottish Executive Rural Affairs Department Programme of Agricultural, Biological and Related Research: Exploitation of Novel and Known Lectins in Agricultural and Biological Research—an Interdisciplinary Approach to Improve Crop Protection and Productivity, Animal (Including Human) Welfare and Health (Project No. FF821). Scottish Executive Rural Affairs Department (http:\\/\\/www.scotland.gov.uk\\/abrg\\/docs\\/pabr-00.asp)] concerned with the discovery and development of new

  2. Sambucus Ribosome-Inactivating Proteins and Lectins

    Microsoft Academic Search

    José Ferreras; Lucía Citores; Rosario Iglesias; Pilar Jiménez; Tomás Girbés

    \\u000a Plant ribosome-inactivating proteins (RIPs) are inhibitors with RNA-N-glycosidase activity that irreversibly inactivate eukaryotic ribosomes, thereby impairing protein synthesis. In recent years,\\u000a more than 40 RIPs and lectins belonging to the Sambucus genus have been isolated and characterized to varying degrees. The type 2 RIPs isolated from Sambucus have the peculiarity that although they are enzymatically more active than ricin, they

  3. Human Sperm Surface Mapping with Lectins

    Microsoft Academic Search

    U. K. Bains; S. Sehgal; S. R. Bawa

    1992-01-01

    Ten fluorescein isothiocyanate (F?TC)-linked lectins [Bauhimia purpurea, Concanavalin A, Dolichos biflorus (DBA), Griffonia simplicifolia I, Griffonia simplicifolia II, Madura pomifera, Arachis hypogea (PNA), Glycine max, Ulex europaeus (UEA) and Triticum vulgaris agglutinin] have been used to study their binding features on the human ejaculate spermatozoa. Qualitative changes in the labeling pattern have been observed in unfixed and acetone-treated spermatozoa. Furthermore,

  4. The seed lectins of black locust (robinia pseudoacacia) are encoded by two genes which differ from the bark lectin genes

    Microsoft Academic Search

    Els J. M. Damme; Annick Barre; Pierre Rougé; Fred Leuven; Willy J. Peumans

    1995-01-01

    Two lectins were isolated from Robinia pseudoacacia (black locust) seeds using affinity chromatography on fetuin-agarose, and ion exchange chromatography on a Neobar CS column. The first lectin, R. pseudoacacia seed agglutinin I, referred to as RPsAI, is a homotetramer of four 34 kDa subunits whereas the second lectin, referred to as RPsAII, is composed of four 29 kDa polypeptides. cDNA

  5. 70-kDa-heat shock protein presents an adjustable lectinic activity towards O-linked N-acetylglucosamine

    Microsoft Academic Search

    Céline Guinez; Jérôme Lemoine; Jean-Claude Michalski; Tony Lefebvre

    2004-01-01

    Numerous works demonstrated that the dynamic O-GlcNAc glycosylation could protect against the proteasomal degradation by modifying the target proteins and the proteasome itself. Considering that Hsp70 is a crucial component in the quality control of protein conformation in the proteasomal pathway, we investigated the possibility that Hsp70 physically interacts with O-GlcNAc proteins through a lectinic activity. First, we demonstrate that

  6. Algal Lectins as Potential HIV Microbicide Candidates

    PubMed Central

    Huskens, Dana; Schols, Dominique

    2012-01-01

    The development and use of topical microbicides potentially offers an additional strategy to reduce the spread of the Human Immunodeficiency Virus (HIV). Carbohydrate-binding agents (CBAs) that show specificity for high mannose carbohydrates on the surface of the heavily glycosylated envelope of HIV are endowed with potent anti-HIV activity. In fact, a number of algal lectins such as cyanovirin-N, microvirin, microcystis viridis lectin, scytovirin, Oscillatoria agardhii agglutinin and griffithsin are considered as potential microbicide candidates to prevent the sexual transmission of HIV through topical applications. They not only inhibit infection of cells by cell-free virus but they can also efficiently prevent virus transmission from virus-infected cells to uninfected CD4+ target T-lymphocytes and DC-SIGN-directed capture of HIV-1 and transmission to CD4+ T lymphocytes. This review focuses on the structural properties and carbohydrate specificity of these algal lectins, their antiviral activity against HIV and several other enveloped viruses, their safety profile and viral resistance patterns. PMID:22851920

  7. Swainsonine toxicosis mimics lectin histochemistry of mannosidosis.

    PubMed

    Alroy, J; Orgad, U; Ucci, A A; Gavris, V E

    1985-07-01

    Cells affected by locoweed (Astragalus lentiginosus) and Swainsona galegifolia toxicosis or mannosidosis exhibit similarities in their catabolism of N-linked glycoproteins and accumulation of cytoplasmic vacuoles. We used nine different biotinylated lectins as histochemical markers for specific sugars and avidin-biotin-peroxidase complex as a visualant to study the cells affected with these conditions. Since locoweed and Swainsona spp block mannosidase activity, we expected a similar lectin staining pattern in cells under these conditions as that seen in mannosidosis. Concanavalia ensiformis agglutinin, wheat germ agglutinin and succinyl wheat germ agglutinin stained the undegraded glycoproteins and oligosaccharides stored in the lysosomes of affected cells in all three conditions. Bandeirea simplicifolia-I, Dolichos biflorus agglutinin, peanut agglutinin, Ricinus communis agglutinin-I, soybean agglutinin and Ulex europaeus agglutinin-I did not stain any of these cells. These results indicate that in all three conditions there is an accumulation of undegraded oligosaccharides that contain alpha-mannosyl and beta-N-acetyl glucosamine residues which are revealed by lectin staining in the vacuoles of all affected cells. PMID:3929453

  8. L-Type lectin from the kuruma shrimp Marsupenaeus japonicus promotes hemocyte phagocytosis.

    PubMed

    Xu, Sen; Wang, Lei; Wang, Xian-Wei; Zhao, Yan-Ran; Bi, Wen-Jie; Zhao, Xiao-Fan; Wang, Jin-Xing

    2014-06-01

    L-Type lectins (LTLs) contain a luminal carbohydrate recognition domain, which exhibits homology to leguminous lectins. These type I membrane proteins are involved in the early secretory pathway of animals, and have functions in glycoprotein sorting, trafficking and targeting. Recent studies suggest that LTLs may be involved in immune responses in vertebrates, but no functional studies have been reported. This study reports an LTL, designated as MjLTL1, from the kuruma shrimp Marsupenaeus japonicus. MjLTL consists of a signal peptide, leguminous lectin domain, and transmembrane region. It was upregulated following challenge of shrimp with Vibrio anguillarum. MjLTL1 could agglutinate several bacteria with the presence of calcium, and bind to several Gram-positive and Gram-negative bacteria through lipopolysaccharide and peptidoglycan binding. MjLTL1 could enhance the clearance of V. anguillarum in vivo. MjLTL1 silencing by RNA interference could impair bacterial clearance ability. Further study suggested that MjLTL1 promoted hemocyte phagocytosis. To analyze the possible mechanism, a disintegrin and metalloprotease-like protein (MjADAM) mediating the proteolytic release of extracellular domains from the membrane-bound precursors was also studied in the shrimp. MjADAM exhibited similar tissue location and expression profiles to MjLTL1. After knockdown of MjADAM, the hemocyte phagocytosis rate also declined significantly. ADAM was reported to have an ectodomain shedding function to LTL and release the ectodomain of the lectin from cell membrane. Therefore, our results suggest that the extracellular domain of MjLTL1 might be released from the cell surface as a soluble protein by MjADAM, and function as an opsonin involved in the antibacterial immune responses in shrimp. PMID:24508102

  9. Defective release of C5a related chemo-attractant activity from complement in Crohn's disease

    Microsoft Academic Search

    J Elmgreen; A Berkowicz; H Sřrensen

    1983-01-01

    Complement was studied in 20 untreated cases of Crohn's disease and in 20 healthy volunteers by an in vitro activation of the cascade reaction. Total haemolytic complement was normal in all patients. In contrast, activation of the alternative pathway lead to a decreased release of C5a related chemo-attractant activity together with a subnormal utilisation of the main complement component C3.

  10. Reactivity of gliadin and lectins with celiac intestinal mucosa.

    PubMed

    Pittschieler, K; Ladinser, B; Petell, J K

    1994-11-01

    The binding patterns of gliadin and selected lectins to jejunal biopsy specimens obtained from children with total villous atrophy during active celiac disease (CD; 19 patients) and in remission (16 patients) were examined by light microscopy. Three categories of carbohydrate-specific lectins were chosen for the study: those recognizing mannose/glucose residues, those recognizing N-acetyl-glucosamine/glucose (glcNAc/glc) residues, and those recognizing N-acetylgalactosamine/galactose (galNAc/gal) residues. The galNAc/gal lectins, with the exception of phaseolus vulgaris agglutinin variants, presented a typical staining of the luminal surface of the jejunal mucosa obtained from CD patients. However, these lectins displayed no reactivity to jejunal sections of CD patients in remission or control biopsies that included healthy children (25 children) and patients suffering from cow milk protein allergy (10 children). The glcNAc/glc lectin showed a strong preferential recognition of CD jejunal tissue but also bound with less intensity to specimens from patients with cow milk allergies and healthy children. Unlike other galNAc/gal lectins, phaseolus vulgaris agglutinin variants were indistinguishable in their binding patterns to the mucosa of control groups and CD patients in remission and failed to react to CD biopsies. The mannose/glc lectins were not distinctive in their binding patterns. In all cases, lectin binding was specifically inhibited by the lectins' competitive saccharides. Atypical of lectin binding patterns, gliadin reactivity was restricted to intracellular areas of enterocytes and was unique to active CD mucosa. The distinctive binding patterns of lectins and gliadin provide a diagnostic tool to distinguish patients with active CD from those in remission or patients with other intestinal disorders.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7877884

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

    ERIC Educational Resources Information Center

    Fuller, Kevin G.

    2008-01-01

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

  12. Complement-Mediated Dysfunction of Glomerular Filtration Barrier Accelerates Progressive Renal Injury

    Microsoft Academic Search

    Mauro Abbate; Carla Zoja; Daniela Corna; Daniela Rottoli; Cristina Zanchi; Nadia Azzollini; Susanna Tomasoni; Silvia Berlingeri; Marina Noris; Marina Morigi; Giuseppe Remuzzi

    2008-01-01

    Intrarenal complement activation leads to chronic tubulointerstitial injury in animal models of proteinuric nephropathies, making this process a potential target for therapy. This study investigated whether a C3-mediated pathway promotes renal injury in the protein overload model and whether the abnormal exposure of proximal tubular cells to filtered complement could trigger the resulting inflammatory response. Mice with C3 deficiency were

  13. ESSENTIAL TWISTED SURFACES IN ALTERNATING LINK COMPLEMENTS

    E-print Network

    Purcell, Jessica

    ESSENTIAL TWISTED SURFACES IN ALTERNATING LINK COMPLEMENTS MARC LACKENBY AND JESSICA S. PURCELL Abstract. Checkerboard surfaces in alternating link complements are used frequently to determine, the geometry of the link complement stabilizes (approaches a geometric limit), but a corresponding checkerboard

  14. Genetics Home Reference: Complement factor I deficiency

    MedlinePLUS

    ... PubMed Recent literature OMIM Genetic disorder catalog Conditions > Complement factor I deficiency On this page: Description Genetic ... names Glossary definitions Reviewed September 2010 What is complement factor I deficiency? Complement factor I deficiency is ...

  15. AC Complement Problems: Satisfiability and Negation Elimination

    E-print Network

    Fernández, Maribel

    AC Complement Problems: Satisfiability and Negation Elimination complement problems interpreted in T(F)==AC, where AC is a set of associative and commutative axioms. For this, we present a system of rewrite rules that transforms any linear complement problem

  16. Genetics Home Reference: Complement component 2 deficiency

    MedlinePLUS

    ... PubMed Recent literature OMIM Genetic disorder catalog Conditions > Complement component 2 deficiency On this page: Description Genetic ... names Glossary definitions Reviewed June 2014 What is complement component 2 deficiency? Complement component 2 deficiency is ...

  17. 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

  18. Plant Lectins: Wheat Defense Strategy Against Hessian Fly

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  19. Lectin-carbohydrate interaction in the immune system

    Microsoft Academic Search

    Y. Ni; I. Tizard

    1996-01-01

    The immune system consists of various types of cells and molecules that specifically interact with each other to initiate the host defense mechanism. Recent studies have shown that carbohydrates and lectins (carbohydrate-binding proteins) play an essential role in mediating such interactions. Both lectins and carbohydrates are widely distributed in the mammalian tissues as well as in microorganisms. Carbohydrates, due to

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

    PubMed

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

    2015-08-01

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

  1. 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

  2. A developmentally regulated lectin in Bufo arenarum embryos.

    PubMed

    Elola, M T; Fink-de-Cabutti, N E; Herkovits, H

    1987-01-01

    We report the levels of an endogenous beta-galactoside lectin activity from Bufo arenarum whole embryos extracts and specific inhibition by saccharides at different developmental stages. Specific activity measured against trypsinized rabbit red blood cells showed relatively high and fluctuating levels during early stages (up to about 76 h post-fertilization) which fell to significantly lower and more constant values at late stages (77-264 h post-fertilization). Lactose is the most potent inhibitor of this lectin activity, and saccharides having alpha-galactoside configurations are weaker inhibitors. At the last embryonic stage, the agglutinating activity showed a different sugar specificity which suggests either the modification of the preexistent lectin or the synthesis of another type of lectin. The possible physiological roles of these lectins in the blockage of polyspermy or in embryonic cell-cell interactions are discussed. PMID:3137989

  3. Electrophysiological correlates of Complement Coercion

    PubMed Central

    Kuperberg, Gina R.; Choi, Arim; Cohn, Neil; Paczynski, Martin; Jackendoff, Ray

    2011-01-01

    This study examined the electrophysiological correlates of complement coercion. Event-related potentials (ERPs) were measured as participants read and made acceptability judgments about plausible coerced sentences, plausible non-coerced sentences, and highly implausible animacy violated sentences (“The journalist began/wrote/astonished the article before his coffee break”). Relative to non-coerced complement nouns, the coerced nouns evoked an N400 effect. This effect was not modulated by the number of possible activities implied by the coerced nouns (e.g. began reading the article; began writing the article), and did not differ in either magnitude or scalp distribution from the N400 effect evoked by the animacy violated complement nouns. We suggest that the N400 modulation to both coerced and the animacy violated complement nouns reflected different types of mismatches between the semantic restrictions of the verb and the semantic properties of the incoming complement noun. This is consistent with models holding that a verb’s semantic argument structure is represented and stored at a distinct level from its syntactic argument structure. Unlike the coerced complement noun, the animacy violated nouns also evoked a robust P600 effect, which may have been triggered by the judgments of the highly implausible (syntactically-determined) meanings of the animacy violated propositions. No additional ERP effects were seen in the coerced sentences until the sentence-final word which, relative to sentence-final words in the non-coerced sentences, evoked a sustained anteriorly-distributed positivity. We suggest that this effect reflected delayed attempts to retrieve the specific event(s) implied by coerced complement nouns. PMID:19702471

  4. Geometric limits of knot complements, II: Graphs determined by their complements

    E-print Network

    Souto, Juan

    Geometric limits of knot complements, II: Graphs determined by their complements Richard P. Kent IV complements. A hyperbolic knot complement is a complete hyperbolic 3­manifold homeomorphic to the complement of a knot in S3. A complete hyperbolic 3­manifold M is a geometric limit of hyperbolic knot complements

  5. Molecular Modeling of Lectin-Like Protein from Acacia farnesiana Reveals a Possible Anti-Inflammatory Mechanism in Carrageenan-Induced Inflammation

    PubMed Central

    Abrantes, Vanessa Erika Ferreira; Matias da Rocha, Bruno Anderson; Batista da Nóbrega, Raphael; Silva-Filho, José Caetano; Teixeira, Claudener Souza; Cavada, Benildo Sousa; Gadelha, Carlos Alberto de Almeida; Ferreira, Sergio Henrique; Figueiredo, Jozi Godoy; Santi-Gadelha, Tatiane; Delatorre, Plinio

    2013-01-01

    Acacia farnesiana lectin-like protein (AFAL) is a chitin-binding protein and has been classified as phytohaemagglutinin from Phaseolus vulgaris (PHA). Legume lectins are examples for structural studies, and this family of proteins shows a remarkable conservation in primary, secondary, and tertiary structures. Lectins have ability to reduce the effects of inflammation caused by phlogistic agents, such as carrageenan (CGN). This paper explains the anti-inflammatory activity of AFAL through structural comparison with anti-inflammatory legume lectins. The AFAL model was obtained by molecular modeling and molecular docking with glycan and carrageenan were performed to explain the AFAL structural behavior and biological activity. Pisum sativum lectin was the best template for molecular modeling. The AFAL structure model is folded as a ? sandwich. The model differs from template in loop regions, number of ? strands and carbohydrate-binding site. Carrageenan and glycan bind to different sites on AFAL. The ability of AFAL binding to carrageenan can be explained by absence of the sixth ?-strand (posterior ? sheets) and two ? strands in frontal region. AFAL can inhibit pathway inflammatory process by carrageenan injection by connecting to it and preventing its entry into the cell and triggers the reaction. PMID:24490151

  6. A Lactose-Binding Lectin from the Marine Sponge Cinachyrella Apion (Cal) Induces Cell Death in Human Cervical Adenocarcinoma Cells

    PubMed Central

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

    2012-01-01

    Cancer represents a set of more than 100 diseases, including malignant tumors from different locations. Strategies inducing differentiation have had limited success in the treatment of established cancers. Marine sponges are a biological reservoir of bioactive molecules, especially lectins. Several animal and plant lectins were purified with antitumor activity, mitogenic, anti-inflammatory and antiviral, but there are few reports in the literature describing the mechanism of action of lectins purified from marine sponges to induce apoptosis in human tumor cells. In this work, a lectin purified from the marine sponge Cinachyrella apion (CaL) was evaluated with respect to its hemolytic, cytotoxic and antiproliferative properties, besides the ability to induce cell death in tumor cells. The antiproliferative activity of CaL was tested against HeLa, PC3 and 3T3 cell lines, with highest growth inhibition for HeLa, reducing cell growth at a dose dependent manner (0.5–10 µg/mL). Hemolytic activity and toxicity against peripheral blood cells were tested using the concentration of IC50 (10 µg/mL) for both trials and twice the IC50 for analysis in flow cytometry, indicating that CaL is not toxic to these cells. To assess the mechanism of cell death caused by CaL in HeLa cells, we performed flow cytometry and western blotting. Results showed that lectin probably induces cell death by apoptosis activation by pro-apoptotic protein Bax, promoting mitochondrial membrane permeabilization, cell cycle arrest in S phase and acting as both dependent and/or independent of caspases pathway. These results indicate the potential of CaL in studies of medicine for treating cancer. PMID:22690140

  7. Entamoeba histolytica Gal/GalNAc lectin depletes antioxidant defences of target epithelial cells.

    PubMed

    Rawal, S; Majumdar, S; Dhawan, V; Vohra, H

    2004-06-01

    Among the variety of virulence factors of Entamoeba histolytica, an adherence lectin (Gal/GalNAc, 260 kDa) is known to mediate colonization and subsequent host responses. Gal/GalNAc lectin is universally recognized by the immune sera of patients with amoebic liver abscess. It plays a crucial role in cytolysis and phagocytosis of human and rat colonic mucin glycoproteins. The objective of the present study was to elucidate the role of antioxidants in E. histolytica Gal/GalNAc lectin-induced signals in the target epithelial cells. We have attempted to define a pathway in target cells, Henle-407 cells (human intestinal epithelial cell line), that could link this immunodominant antigen to a known biological pathway for target cell activation and triggering of subsequent disease pathology/parasite survival. Since several workers have demonstrated that cAMP and cGMP may act as important cellular signals for altering ion transport, so in the present study, cAMP and cGMP levels were measured in Henle-407 cells which showed significant increase at 15 min after stimulation. Elevated cAMP and cGMP levels are implicated in altered electrolyte transport and conductance. Results showed that there were increased levels of ROS and RNI which led to reduced activities of antioxidant enzymes--catalase, superoxide dismutase and glutathione peroxidase. Despite the increased glutathione (reduced) levels, the enzymes were not able to combat the damage caused by ROS and RNI. Thus, there was an increased local concentration of the free radicals and reduced activities of all the three enzymes which could damage the target cell in terms of cytoskeleton and permeability changes. PMID:15206463

  8. The action of MBL-associated serine protease 1 (MASP1) on factor XIII and fibrinogen

    Microsoft Academic Search

    Anders Krarup; Krishana C. Gulla; Péter Gál; Krishnan Hajela; Robert B. Sim

    2008-01-01

    The complement system is an important recognition and effector mechanism of the innate immune system that upon activation leads to the elimination of foreign bodies. It can be activated through three pathways of which the lectin pathway is one. The lectin pathway relies on the binding of mannan-binding lectin (MBL) or the ficolins and the subsequent activation of the MBL-associated

  9. Complementation system for Helicobacter pylori.

    PubMed

    Kim, Jinmoon; Kim, Sung-Whan; Jang, Sungil; Merrell, D Scott; Cha, Jeong-Heon

    2011-06-01

    Previously Langford et al. (2006) developed the pIR203C04 complementation system for Helicobacter pylori, which can be used to complement and restore phenotypic effects in H. pylori mutant, and furthermore they used the complementation system in vivo experiments to animals without altering the ability of strain SSI to colonize mice. In their previous study, the pIR203C04 was able to transform 26695, SSI, J99, and 43504 H. pylori strains by an electroporation method. However, in the present study using a natural transformation the pIR203C04 transformed only 26695 H. pylori but not SSI, J99, 7.13, and G27 H. pylori strains. Since the useful complementation system has a limitation of narrow selection among H. pylori strains, we redesigned the complementation system for the improvement. The same intergenic chromosomal site between hp0203 and hp0204 was utilized for the new complementation system because the insertion at the intergenic site didn't show any polar effects and disruption of other H. pylori genes. The genome sequence analysis showed that the intergenic regions among H. pylori strains may have too low homology to each others to do a homologous recombination. Thus, in addition to the short intergenic region, the fragments of the new complementation system included 3' conserved parts of hp0203 and hp0204 coding regions. Between the fragments there are a chloramphenicol acetyltransferase cassette and multicloning sites, resulting in pKJMSH. DNA fragment of the interest can be cloned into the multicloning sites of pKJMSH and the fragment can be integrated at the intergenic region of H. pylori chromosome by the homologous recombination. Indeed, by the natural transformation, pKJMSH was able to transform all five H. pylori strains of 26695, SSI, J99, 7.13, and G27, which are common for the investigation of molecular pathogenesis. Thus, the new pKJMSH complementation system is applicable to most H. pylori wild-type stains. PMID:21717336

  10. A jacalin-related lectin-like gene in wheat is a component of the plant defence system.

    PubMed

    Xiang, Yang; Song, Min; Wei, Zhaoyan; Tong, Jianhua; Zhang, Lixia; Xiao, Langtao; Ma, Zhengqiang; Wang, Yun

    2011-11-01

    Jacalin-related lectins (JRLs) are a subgroup of proteins with one or more jacalin-like lectin domains. Although JRLs are often associated with biotic or abiotic stimuli, their biological functions in plants, as well as their relationships to plant disease resistance, are poorly understood. A mannose-specific JRL (mJRL)-like gene (TaJRLL1) that is mainly expressed in stem and spike and encodes a protein with two jacalin-like lectin domains was identified in wheat. Pathogen infection and phytohormone treatments induced its expression; while application of the salicylic acid (SA) biosynthesis inhibitor paclobutrazol and the jasmonic acid (JA) biosynthesis inhibitor diethyldithiocarbamic acid, respectively, substantially inhibited its expression. Attenuating TaJRLL1 through virus-induced gene silencing increased susceptibility to the facultative fungal pathogen Fusarium graminearum and the biotrophic fungal pathogen Blumeria graminis. Arabidopsis thaliana transformed with TaJRLL1 displayed increased resistance to F. graminearum and Botrytis cinerea. JA and SA levels in transgenic Arabidopsis increased significantly. A loss or increase of disease resistance due to an alteration in TaJRLL1 function was correlated with attenuation or enhancement of the SA- and JA-dependent defence signalling pathways. These results suggest that TaJRLL1 could be a component of the SA- and JA-dependent defence signalling pathways. PMID:21862481

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

    PubMed Central

    Michelow, Ian C.; Lear, Calli; Scully, Corinne; Prugar, Laura I.; Longley, Clifford B.; Yantosca, L. Michael; Ji, Xin; Karpel, Marshall; Brudner, Matthew; Takahashi, Kazue; Spear, Gregory T.; Ezekowitz, R. Alan B.; Olinger, Gene G.

    2011-01-01

    Mannose-binding lectin (MBL) targets diverse microorganisms for phagocytosis and complement-mediated lysis by binding specific surface glycans. Although recombinant human MBL (rhMBL) trials have focused on reconstitution therapy, safety studies have identified no barriers to its use at higher levels. Ebola viruses cause fatal hemorrhagic fevers for which no treatment exists and that are feared as potential biothreat agents. We found that mice whose rhMBL serum concentrations were increased ?7-fold above average human levels survived otherwise fatal Ebola virus infections and became immune to virus rechallenge. Because Ebola glycoproteins potentially model other glycosylated viruses, rhMBL may offer a novel broad-spectrum antiviral approach. PMID:21288816

  12. Myeloid dendritic cells display downregulation of C-type lectin receptors and aberrant lectin uptake in systemic lupus erythematosus

    PubMed Central

    Monrad, Seetha U; Rea, Kristine; Thacker, Seth; Kaplan, Mariana J

    2008-01-01

    Introduction There is a growing body of evidence implicating aberrant dendritic cell function as a crucial component in the immunopathogenesis of systemic lupus erythematosus. The purpose of the present study was to characterize the phagocytic capacity and expression of receptors involved in pathogen recognition and self-nonself discrimination on myeloid dendritic cells from patients with lupus. Methods Unstimulated or stimulated monocyte-derived dendritic cells were obtained from lupus patients and healthy control individuals, and expression of C-type lectin receptors (mannose receptor and dendritic cell-specific intercellular adhesion molecule-grabbing nonintegrin), complement-receptor 3 and Fc? receptors was determined by flow cytometry. Dextran uptake by lupus and control dendritic cells was also assessed by flow cytometry. Serum IFN? was quantified by ELISA, and uptake of microbial products was measured using fluorescently labeled zymosan. Results When compared with dendritic cells from healthy control individuals, unstimulated and stimulated lupus dendritic cells displayed significantly decreased dextran uptake and mannose receptor and dendritic cell-specific intercellular adhesion molecule-grabbing nonintegrin expression. Decreased expression of the mannose receptor was associated with high serum IFN? levels, but not with maturation status or medications. Diminished dextran uptake and mannose receptor expression correlated with lupus disease activity. There were no differences between control and lupus dendritic cells in the expression of other pattern recognition receptors or in the capacity to uptake zymosan particles Conclusions Lupus dendritic cells have diminished endocytic capacity, which correlates with decreased mannose receptor expression. While this phenomenon appears primarily intrinsic to dendritic cells, modulation by serum factors such as IFN? could play a role. These abnormalities may be relevant to the aberrant immune homeostasis and the increased susceptibility to infections described in lupus. PMID:18811944

  13. Characterization of a lectin from goat peripheral blood lymphocytes.

    PubMed

    Kayestha, R; Sumati; Hajela, K

    1996-12-01

    A D-glucose specific lectin was isolated from goat peripheral blood lymphocytes by affinity chromatography on N-acetyl D-glucosamine agarose gel. The fluorescence intensity of 4 methyl umbelliferyl D-glucose was quenched to about 62% on addition of the lectin. This lectin gave a single band corresponding to 112 kDa in SDS-PAGE irrespective of treatment with 2-mercaptoethanol. The molecular weight and the Stoke's radius of the lectin in the native conditions were found to be 114 kDa and 4.54 nm, respectively, as determined by gel filtration on Sephacryl S 500 column. The lectin was found to be a glycoprotein with 5.6% of neutral hexose content and 5.5% of sialic acid. The lectin agglutinated trypsinized rabbit erythrocytes and human type A erythrocytes. The hemagglutinating activity was dependent on the presence of divalent cations like Mn2+ and Ca2+. Optimum pH, ionic strength and temperature for rebinding of lectin to acid treated Sephadex G200 were found to be 7.5, 0.16 and 30-37 degrees C, respectively. PMID:9219437

  14. Extensive amino acid sequence homologies between animal lectins

    SciTech Connect

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

    1987-09-01

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

  15. Cloning and characterization of root-specific barley lectin

    SciTech Connect

    Lerner, D.R.; Raikhel, N.V. (Michigan State Univ., East Lansing (USA))

    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.

  16. Upregulation of glycans containing 3' fucose in a subset of pancreatic cancers uncovered using fusion-tagged lectins.

    PubMed

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

    2015-06-01

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

  17. Improvisation: A Complement to Curriculum

    ERIC Educational Resources Information Center

    Ronald, Green A.

    2006-01-01

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

  18. Effect of garlic supplementation on complement activity in broiler chickens

    Microsoft Academic Search

    Ramezan Ali Jafari; Masood Ghorbanpoor; Meysam Makkei

    Recent studies have demonstrated the potential immuno-modulatory activity of herbal products in human and animals. The present\\u000a study was performed to elucidate the impact of including fresh garlic powder (FGP) in the diet of broiler chicks on serum\\u000a alternative pathway of complement activation (APCA) activity, as a functional part of humoral innate immunity. For this, two\\u000a hundred new-born chicks were

  19. Function of Serum Complement in Drinking Water Arsenic Toxicity

    PubMed Central

    Islam, Laila N.; Zahid, M. Shamim Hasan; Nabi, A. H. M. Nurun; Hossain, Mahmud

    2012-01-01

    Serum complement function was evaluated in 125 affected subjects suffering from drinking water arsenic toxicity. Their mean duration of exposure was 7.4 ± 5.3?yrs, and the levels of arsenic in drinking water and urine samples were 216 ± 211 and 223 ± 302??g/L, respectively. The mean bactericidal activity of complement from the arsenic patients was 92% and that in the unexposed controls was 99% (P < 0.01), but heat-inactivated serum showed slightly elevated activity than in controls. In patients, the mean complement C3 was 1.56?g/L, and C4 was 0.29?g/L compared to 1.68?g/L and 0.25?g/L, respectively, in the controls. The mean IgG in the arsenic patients was 24.3?g/L that was highly significantly elevated (P < 0.001). Arsenic patients showed a significant direct correlation between C3 and bactericidal activity (P = 0.014). Elevated levels of C4 indicated underutilization and possibly impaired activity of the classical complement pathway. We conclude reduced function of serum complement in drinking water arsenic toxicity. PMID:22545044

  20. Complement C3c as a Biomarker in Heart Failure

    PubMed Central

    Frey, A.; Ertl, G.; Angermann, C. E.; Hofmann, U.; Störk, S.; Frantz, S.

    2013-01-01

    Introduction. Experimental data indicates an important role of the innate immune system in cardiac remodeling and heart failure (HF). Complement is a central effector pathway of the innate immune system. Animals lacking parts of the complement system are protected from adverse remodeling. Based on these data, we hypothesized that peripheral complement levels could be a good marker for adverse remodeling and prognosis in patients with HF. Methods and Results. Since complement activation converges on the complement factor C3, we measured serum C3c, a stable C3-conversion product, in 197 patients with stable systolic HF. Subgroups with normal and elevated C3c levels were compared. C3c levels were elevated in 17% of the cohort. Patients with elevated C3c levels exhibited a trend to better survival, slightly higher LVEF, and lower NTpro-BNP values in comparison to patients with normal C3c values. No differences were found regarding NYHA functional class. Significantly more patients with elevated C3c had preexisting diabetes. The prevalence of CAD, arterial hypertension, and atrial fibrillation was not increased in patients with elevated C3c. Conclusion. Elevated C3c levels are associated with less adverse remodeling and improved survival in patients with stable systolic heart failure. PMID:24489446

  1. Structural analysis of Canavalia maritima and Canavalia gladiata lectins complexed with different dimannosides: New insights into the understanding of the structure–biological activity relationship in legume lectins

    Microsoft Academic Search

    Gustavo Arruda Bezerra; Taianá Maia Oliveira; Frederico Bruno Mendes Batista Moreno; Emmanuel Prata de Souza; Bruno Anderson Matias da Rocha; Raquel Guimarăes Benevides; Plínio Delatorre; Walter Filgueira de Azevedo; Benildo Sousa Cavada

    2007-01-01

    Plant lectins, especially those purified from species of the Leguminosae family, represent the best studied group of carbohydrate-binding proteins. The legume lectins from Diocleinae subtribe are highly similar proteins that present significant differences in the potency\\/efficacy of their biological activities. The structural studies of the interactions between lectins and sugars may clarify the origin of the distinct biological activities observed

  2. Geometric limits of knot complements, II: Graphs determined by their complements

    E-print Network

    Kent IV, Richard Peabody

    Geometric limits of knot complements, II: Graphs determined by their complements Richard P. Kent IV interiors are not homeomorphic to any geometric limit of hyperbolic knot complements. A hyperbolic knot complement is a complete hyperbolic 3­manifold homeomorphic to the complement of a knot in S3. A complete

  3. 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.

  4. 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.

  5. The Use of Lectins (Agglutinins) to Study Cell Surfaces

    NSDL National Science Digital Library

    Ingrith Deyrup-Olsen (University of Washington; )

    1982-06-21

    Using lectins, proteins which combine specifically with carbohydrate molecules or groups, this activity will introduce the students to the many important roles that the cell membrane serves in biological processes.

  6. Anti-Cad lectin from the seeds of Leonurus cardiaca.

    PubMed

    Bird, G W; Wingham, J

    1979-01-01

    A predominantly Cad-specific lectin is present in the seeds of Leonurus cardiaca. Extracts of these seeds makes a valuable addition to reagents used in the elucidation of red cell polyagglutinability. PMID:535304

  7. Lectins from seeds of Crotalaria pallida (smooth rattlebox)

    Microsoft Academic Search

    Evandro J. L. Rego; Daniela D. de Carvalho; Sergio Marangoni; Benedito de Oliveira; José C. Novello

    2002-01-01

    Differences in the amino acid composition and hemagglutination properties of lectins from seeds of Crotalaria pallida and the taxonomically synonymous Crotalaria striata, suggest the presence of isolectins in the C. pallida new status of species.

  8. Lectin histochemistry of the esophagus in several mammalian species.

    PubMed

    Poorkhalkali, N; Jacobson, I; Helander, H F

    1999-11-01

    The mucosa of the esophagus consists of stratified squamous epithelium that has a considerable resistance to injury. Intercellular glycoconjugates appear to constitute a major permeability barrier in the superficial portion of the esophageal mucosa. In the present study, we used a panel of lectins to investigate the differences in glycoconjugate production among different mammalian species. A battery of 12 lectins was used to study binding in sections from the esophagus of 6 mammalian species, including man. In general, the strongest staining was obtained in the stratum superficiale and the weakest staining in the stratum germinativum. In rabbit esophagus, exposure to pepsin/HCl produced a superficial damage to the epithelium, a considerable decrease in electrical resistance and a decreased staining of the esophageal epithelium with selected lectins. Pretreatment of the esophageal mucosa with sucrose octasulfate, a compound with protective properties, prevented, to some extent, the decrease in resistance and lectin staining. PMID:10526022

  9. 21 CFR 864.9550 - Lectins and protectins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Products Used In Establishments That Manufacture Blood and Blood Products § 864.9550 Lectins and...

  10. 21 CFR 864.9550 - Lectins and protectins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Products Used In Establishments That Manufacture Blood and Blood Products § 864.9550 Lectins and...

  11. 21 CFR 864.9550 - Lectins and protectins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

  12. 21 CFR 864.9550 - Lectins and protectins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

  13. 21 CFR 864.9550 - Lectins and protectins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

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

    PubMed Central

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

    2014-01-01

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

  15. Floer homology and knot complements

    Microsoft Academic Search

    Jacob Rasmussen

    2003-01-01

    We use the Ozsvath-Szabo theory of Floer homology to define an invariant of knot complements in three-manifolds. This invariant takes the form of a filtered chain complex, which we call CF_r. It carries information about the Floer homology of large integral surgeries on the knot. Using the exact triangle, we derive information about other surgeries on knots, and about the

  16. Vicia villosa Lectin Is a Mitogen for Mouse T Lymphocytes

    Microsoft Academic Search

    Sergio Abrignani; Salvatore Cammisuli

    1988-01-01

    Mouse T lymphocytes cultured in the presence of Vicia villosa lectin, usually considered to be non-mitogenic, proliferate and produce interleukin-2. V. villosa-induced proliferation does not correlate with the cell ability to adhere to V. villosa-coated dishes, this is evident from the fact that either V. villosa-adherent or -nonadherent cells are equally sensitive to the mitogenic effect of the lectin. Furthermore,

  17. Vasodilator effects of Diocleinae lectins from the Canavalia genus

    Microsoft Academic Search

    Ana Maria Sampaio Assreuy; Sabrina Rodrigues Fontenele; Alana de Freitas Pires; Débora Costa Fernandes; Natália Velloso Fontenelle C. Rodrigues; Eduardo Henrique Salviano Bezerra; Tales Rocha Moura; Kyria Santiago do Nascimento; Benildo Sousa Cavada

    2009-01-01

    This study investigated and compared vascular actions of leguminous lectins obtained from the Canavalia genus (Canavalia brasiliensis, Canavalia gladiata, and Canavalia maritima) in the rat models of paw edema and isolated aorta. Paw edema was induced by subcutaneous injection of lectins (0.01–1 mg\\/kg)\\u000a in animals pre-treated or not with indomethacin or L-NAME. In isolated aorta, cumulative concentration curves of C. gladiata

  18. Fruit-specific lectins from banana and plantain

    Microsoft Academic Search

    Willy J. Peumans; Wenling Zhang; Annick Barre; Corinne Houlčs Astoul; Peter J. Balint-Kurti; Paula Rovira; Pierre Rougé; Gregory D. May; Fred Van Leuven; Paolo Truffa-Bachi; Els J. M. Van Damme

    2000-01-01

    .  ?One of the predominant proteins in the pulp of ripe bananas (Musa acuminata L.) and plantains (Musa spp.) has been identified as a lectin. The banana and plantain agglutinins (called BanLec and PlanLec, respectively) were\\u000a purified in reasonable quantities using a novel isolation procedure, which prevented adsorption of the lectins onto insoluble\\u000a endogenous polysaccharides. Both BanLec and PlanLec are dimeric

  19. Combination of immunological and lectin reactions in affinity histochemistry: proposition of the term affinitin.

    PubMed

    Franz, H; Bergmann, P; Ziska, P

    1979-02-21

    Using the series system cell receptor leads to mistletoe lectin leads to antiferritin-antibody leads to ferritin, the possibilities for combination of lectin and immunological reactions for histochemistry are discussed. The system cell antigen leads to antibody leads to labelled mistletoe (or other) lectin is recommended for visualization of cell antigens (mistletoe lectin as common immunoglobulin reagent). It is pointed out that lectin reactions do not belong to immunhistochemistry but to affinity histochemistry. For all receptor specific proteins (antibodies, lectins, enzymes, haptoglobin and other) the term affinitin is proposed. In consideration of this new definition a common scheme is formulated: Affinitin reacts with affinitin receptor forming affinity product. PMID:429209

  20. 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 256?g/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

  1. Genetics Home Reference: Mannose-binding lectin deficiency

    MedlinePLUS

    ... viruses, or yeast and turning on (activating) the complement system. The complement system is a group of immune system proteins ... Health National Institute of Allergy and Infectious Diseases: Complement System Educational resources - Information pages (4 links) Patient ...

  2. Roles of antibodies and complement in phagocytic killing of enterococci.

    PubMed Central

    Arduino, R C; Murray, B E; Rakita, R M

    1994-01-01

    The contributions of complement and antibodies to polymorphonuclear leukocyte (PMN)-mediated killing of enterococci were investigated with pooled normal human serum (PNHS) or immune human sera (IHS) from patients with serious enterococcal infections. Each IHS containing antienterococcal antibodies demonstrated by enzyme-linked immunosorbent assay and Western blotting (immunoblotting) was examined with the enterococcus strain isolated from the same patient. PNHS promoted PMN-mediated killing of enterococci similar to that for IHS. PMN-mediated killing was consistently abrogated after preopsonization with heat-inactivated PNHS, but some heat-inactivated IHS supported neutrophil bactericidal activity. Inhibition of the classical pathway of complement by chelation of either PNHS or IHS with Mg-EGTA [Mg-ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid] did not alter PMN-mediated killing, suggesting that activation of the alternative pathway of complement is sufficient to promote killing of enterococci by PMNs. PMN-mediated killing assays were also performed with normal rabbit serum and immune rabbit serum against enterococci. Preopsonization with heat-inactivated immune rabbit serum resulted in PMN-mediated killing of enterococci, which was ablated after adsorption of the serum with the same isolate used for immunization. The influence of different phenotypic enterococcal traits on neutrophil-mediated killing was also investigated. Similar kinetics of killing were observed for derivatives of Enterococcus faecalis strains regardless of resistance to antimicrobial agents or production of beta-lactamase, hemolysin, gelatinase, or surface proteins involved in the aggregative response to pheromones. In summary, PMN-mediated killing of enterococci appears to depend primarily on complement activation by either the classical or the alternative pathway. Human antienterococcal antibodies generated during infection variably promoted neutrophil bactericidal activity, while antibody raised in a rabbit supported PMN-mediated killing of the organism examined. Finally, the different phenotypic properties of E. faecalis examined did not influence the neutrophil-mediated killing of these organisms. Images PMID:8112874

  3. Detection and Verification of Glycosylation Patterns of Glycoproteins from Clinical Specimens Using Lectin Microarrays and Lectin-based Immunosorbent Assays

    PubMed Central

    Li, Yan; Tao, Sheng-Ce; Bova, G. Steven; Liu, Alvin Y.; Chan, Daniel W.; Zhu, Heng; Zhang, Hui

    2011-01-01

    Aberrant glycosylation is a fundamental characteristic of progression of diseases such as cancer. Therefore, characterization of glycosylation patterns of proteins from disease tissues may identify changes specific to the disease development and improve diagnostic performance. Thus, analysis strategies with sufficient sensitivity for evaluation of glycosylation patterns in clinical specimens are needed. Here, we describe an analytical strategy for detection and verification of glycosylation patterns. It is based on a two-phase platform including a pattern discovery phase to identify the glycosylation changes using high-density lectin microarrays and a verification phase by developing lectin-based immunosorbent assays using the identified lectins. We evaluated the analytical performance of the platform using the glycoprotein standard, and found that the lectin microarray could detect specific bindings of glycoprotein to lectins at the nanogram level and the lectin-based immunosorbent assay could be used for verification of protein glycosylation. We then applied the approach to the analysis of glycosylation patterns of two glycoproteins, which are highly expressed in prostate cancer in our prior studies, PSA and membrane metallo-endopeptidase (MME), from aggressive (AC) and non-aggressive prostate cancer (NAC) tissues. The observed differences in glycosylation patterns of PSA and MME may represent significant clinical importance, and could used to develop multiplex assays for diagnosis of aggressive prostate cancer. PMID:21975078

  4. Comprehensive lectin histochemistry of normal and neoplastic human choroid plexus cells: alternation of lectin-binding patterns through neoplastic transformation.

    PubMed

    Kaneko, Y; Iwaki, T; Matsushima, T; Fukui, M

    1991-01-01

    Lectin histochemistry of the normal and neoplastic human choroid plexus cells [six choroid plexus papillomas (CPPs) and three choroid plexus carcinomas (CPCs)] was performed using eight representative lectins to study the development of sugar chain structures and also to determine whether lectins were useful for a histopathological diagnosis of choroid plexus neoplasms (CPNs). The normal choroid plexus cells reacted with Ricinus communis (RCA-I). Canavalia ensiformis (Con A), Limax flavus (LFA) and Triticum vulgaris (WGA), while Arachis hypoaea (PNA) stained them only after the removal of sialic acid. Human fetal choroid plexus cells at 8 weeks gestation already showed the same lectin-binding patterns as adult ones. All CPNs were stained by RCA-I and Con A in a similar manner as the normal choroid plexus cells. Although seven CPNs were positive for LFA, two CPCs were not stained by LFA, which bound to sialic acid. Two LFA-positive CPPs were stained by PNA before the removal of sialic acid. Moreover, unlike the normal choroid plexus cells, Ulex europaeus-, Glycine maximus- and Dolichos biflorus-binding sites often appeared, and WGA-binding sites of three CPNs remained even after sialic acid removal. In conclusion, the glycosialylation in normal choroid plexus cells was completed during the early embryonic stage. The lectin-binding patterns of CPNs were heterogenous in each case. The alternation of the glycosialylation and/or acquisition of binding sites for some lectins was sometimes observed through a neoplastic transformation. PMID:1927268

  5. Complement modulation in solid-organ transplantation.

    PubMed

    Touzot, Maxime; Obada, Erika Nnang; Beaudreuil, Severine; François, Hélčne; Durrbach, Antoine

    2014-07-01

    The complement system is a major constituent of the innate immune system. It has a critical role in defense against pathogens but dysregulation of complement activation may lead to tissue injury and modulate the adaptive immune response. In organ transplantation, local complement activation is involved in hyper-acute rejection and antibody-mediated rejection. This last decade, interest in complement activation has increased due to new insights into the pathophysiology of antibody-mediated rejection, but also since the availability of news drugs that target terminal complement activation. In this review, we discuss our current understanding of how local complement activation induces acute and chronic graft injury, and review recent advances in clinical trials that block complement activation using the anti-C5 monoclonal antibody, eculizumab. Finally, we discuss how complement-targeted therapy may be integrated into our current immunosuppressive regimen and what type of patient will benefit most from this therapy. PMID:24996770

  6. Complement fixation test to C. burnetii

    MedlinePLUS

    The complement fixation test to C. burnetii is a blood test that checks for infection due to bacterium called ... for Coxiella antibodies using a laboratory method called complement fixation. This technique checks if the body has ...

  7. The crystal structure of a complement-1q family protein suggests an evolutionary link to tumor necrosis factor

    Microsoft Academic Search

    Lawrence Shapiro; Philipp E. Scherer

    1998-01-01

    ACRP30 – adipocyte complement-related protein of 30 kDa or AdipoQ – is an abundant serum protein, secreted exclusively from fat cells, which is implicated in energy homeostasis and obesity [1,2]. ACRP30 is a close homologue of the complement protein C1q, which is involved in the recognition of microbial surfaces [3–5] and antibody–antigen complexes [6,7] in the classical pathway of complement.

  8. Complement in human reproduction: Activation and control

    Microsoft Academic Search

    Isabelle A. Rooney; Teresa J. Oglesby; John P. Atkinson

    1993-01-01

    The behaviour of the complement system during human reproduction is now the focus of much scientific attention. The presence\\u000a of antisperm antibodies in the reproductive tracts of some infertile individuals, and of complement in cervical and ovarian\\u000a follicular fluid, suggests that complement-mediated damage of spermatozoa is involved in some cases of infertility. Further,\\u000a deposition of maternal IgG and of complement

  9. Recognition of the N-terminal lectin domain of FimH adhesin by the usher FimD is required for type 1 pilus biogenesis

    Microsoft Academic Search

    Diana Munera; Scott Hultgren; Luis Ángel Fernández

    2007-01-01

    Summary In this work we discover that a specific recognition of the N-terminal lectin domain of FimH adhesin by the usher FimD is essential for the biogenesis of type 1 pili in Escherichia coli. These filamentous organelles are assembled by the chaperone-usher pathway, in which binary complexes between fim- brial subunits and the periplasmic chaperone FimC are recognized by the

  10. Pea lectin receptor-like kinase promotes high salinity stress tolerance in bacteria and expresses in response to stress in planta

    Microsoft Academic Search

    Amita Joshi; Hung Quang Dang; Neha Vaid; Narendra Tuteja

    2010-01-01

    The plant lectin receptor-like kinases (LecRLKs) are involved in various signaling pathways but their role in salinity stress\\u000a tolerance has not heretofore been well described. Salinity stress negatively affects plant growth\\/productivity and threatens\\u000a food security worldwide. Based on functional gene-mining assay, we have isolated 34 salinity tolerant genes out of one million\\u000a Escherichia coli (SOLR) transformants containing pea cDNAs grown

  11. THE VOLUME OF HYPERBOLIC ALTERNATING LINK COMPLEMENTS

    E-print Network

    Lackenby, Marc

    THE VOLUME OF HYPERBOLIC ALTERNATING LINK COMPLEMENTS MARC LACKENBY with an appendix by Ian Agol of a knot complement to the knot's more basic topological properties. In this paper, we will do is the following rather surprising result, which asserts that the link complement's hyperbolic volume is, up

  12. From Complementation to Certification Orna Kupferman

    E-print Network

    Vardi, Moshe Y.

    From Complementation to Certification Orna Kupferman Hebrew University # Moshe Y. Vardi Rice the emptiness of the product of a system S with an automaton A¬# for the complemented specification. This gives rise to two automata­theoretic problems: complementation of word automata, which is used in order

  13. From Complementation to Certification Orna Kupferman

    E-print Network

    Vardi, Moshe Y.

    From Complementation to Certification Orna Kupferman Hebrew University #3; Moshe Y. Vardi Rice the emptiness of the product of a system S with an automaton A: for the complemented specification. This gives rise to two automata­theoretic problems: complementation of word automata, which is used in order

  14. Maximal complements in finite groups Martyn Quick

    E-print Network

    St Andrews, University of

    Maximal complements in finite groups Martyn Quick School of Mathematics and Statistics X . The maxi­ mal subgroups of G which complement N and their conjugacy classes are parametrised Introduction In [8], Parker and the author classified maximal subgroups of a wreath prod­ uct which complement

  15. On Complementing Nondeterministic Buchi Automata Sankar Gurumurthy

    E-print Network

    Kupferman, Orna

    On Complementing Nondeterministic B¨uchi Automata Sankar Gurumurthy , Orna Kupferman ¡£¢ , Fabio-up that complementation involves, these algorithms have never been used in practice, even though an effective complementation con- struction would be of significant practical value. Recently, Kupferman and Vardi described

  16. On Complementing Nondeterministic B uchi Automata

    E-print Network

    Vardi, Moshe Y.

    On Complementing Nondeterministic B Ë? uchi Automata Sankar Gurumurthy 1 , Orna Kupferman 2# , Fabio­up that complementation involves, these algorithms have never been used in practice, even though an effective complementation con­ struction would be of significant practical value. Recently, Kupferman and Vardi described

  17. The Role of Complement Anaphylatoxins in

    E-print Network

    The Role of Complement Anaphylatoxins in CNS Pathology and Glial Cell Function Sarah Ingersoll Ph Activation Complement proteins have long been known for their role in mediating functions that protect the host from harmful pathogens; however excess complement activation can be detrimental to the host

  18. Trace fields and commensurability of link complements

    E-print Network

    Chesebro, Eric Bruce

    Trace fields and commensurability of link complements E. Chesebro and J. DeBlois August 8, 2007 of hyperbolic 3-manifolds. We construct an infinite family of two-component hyperbolic link complements which hyperbolic 3-manifolds with the same property. We also show that the two-component link complements above

  19. RESEARCH Open Access Sex chromosome complement regulates

    E-print Network

    Sibille, Etienne

    RESEARCH Open Access Sex chromosome complement regulates expression of mood-related genes Marianne-related factors (sex chromosome complement, developmental gonadal sex, or adult circulating hormones) to frontal is determined by sex chromosome complement, the role of sex chromosomes cannot be investigated individually

  20. The Buchi Complementation Saga Moshe Y. Vardi #

    E-print Network

    Vardi, Moshe Y.

    The BË?uchi Complementation Saga Moshe Y. Vardi # Rice University, Department of Computer Science://www.cs.rice.edu/ # vardi Abstract. The complementation problem for nondeterministic word au­ tomata has numerous verification problems are reduced, involves complementation. For automata on finite words, which correspond

  1. Maximal complements in finite groups Martyn Quick

    E-print Network

    St Andrews, University of

    Maximal complements in finite groups Martyn Quick School of Mathematics and Statistics X. The maxi- mal subgroups of G which complement N and their conjugacy classes are parametrised Introduction In [8], Parker and the author classified maximal subgroups of a wreath prod- uct which complement

  2. Vol. ?, No. ?, Fall ???? 1 Ten's Complement Arithmetic

    E-print Network

    Borchers, Brian

    Vol. ?, No. ?, Fall ???? 1 Ten's Complement Arithmetic Brian Borchers Many mechanical adding's complement arithmetic [1]. The Hoffritz adder that we will use in our examples has seven digits. On this machine, 9999999+1 rolls over to 0 instead of 10000000. This behavior is the key to the ten's complement

  3. Microbe-specific C3b deposition in the horseshoe crab complement system in a C2/factor B-dependent or -independent manner.

    PubMed

    Tagawa, Keisuke; Yoshihara, Toyoki; Shibata, Toshio; Kitazaki, Kazuki; Endo, Yuichi; Fujita, Teizo; Koshiba, Takumi; Kawabata, Shun-ichiro

    2012-01-01

    Complement C3 plays an essential role in the opsonization of pathogens in the mammalian complement system, whereas the molecular mechanism underlying C3 activation in invertebrates remains unknown. To understand the molecular mechanism of C3b deposition on microbes, we characterized two types of C2/factor B homologs (designated TtC2/Bf-1 and TtC2/Bf-2) identified from the horseshoe crab Tachypleus tridentatus. Although the domain architectures of TtC2/Bf-1 and TtC2/Bf-2 were identical to those of mammalian homologs, they contained five-repeated and seven-repeated complement control protein domains at their N-terminal regions, respectively. TtC2/Bf-1 and TtC2/Bf-2 were synthesized and glycosylated in hemocytes and secreted to hemolymph plasma, which existed in a complex with C3 (TtC3), and their activation by microbes was absolutely Mg(2+)-dependent. Flow cytometric analysis revealed that TtC3b deposition was Mg(2+)-dependent on Gram-positive bacteria or fungi, but not on Gram-negative bacteria. Moreover, this analysis demonstrated that Ca(2+)-dependent lectins (C-reactive protein-1 and tachylectin-5A) were required for TtC3b deposition on Gram-positive bacteria, and that a Ca(2+)-independent lectin (Tachypleus plasma lectin-1) was definitely indispensable for TtC3b deposition on fungi. In contrast, a horseshoe crab lipopolysaccharide-sensitive protease factor C was necessary and sufficient to deposit TtC3b on Gram-negative bacteria. We conclude that plasma lectins and factor C play key roles in microbe-specific TtC3b deposition in a C2/factor B-dependent or -independent manner. PMID:22611464

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

    PubMed Central

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

    2011-01-01

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

  5. A second form of collagenous lectin from the tunicate, Styela plicata Peter Green 1

    E-print Network

    Raftos, David

    acid; FSW, sterile filtered seawater; galNAc, N-acetyl-D-galactosa- mide; GBS, goat blocking serum; glu-binding lectin- associated serine protease; MBL, mannose-binding lectin; PBS, phosphate buffered saline; PMSF

  6. Location of lectin receptors on rat hepatocytes by transmission and scanning electron microscopy

    Microsoft Academic Search

    M. Horisberger; J. Rosset; M. Vonlanthen

    1978-01-01

    Summary Rexeptors for various lectins have been located on isolated hepatocytes by transmission and scanning electron microscopy, using gold markers of variable sizes. Quantitative data indicated that binding of some lectin markers depended upon their sizes.

  7. Detection of surface bound complement at increasing serum anticoagulant concentrations.

    PubMed

    Arvidsson, S; Askendal, A; Lindahl, T L; Tengvall, P

    2008-04-01

    Surface mediated immune complement activation can be detected by a variety of antibody utilizing methods such as ELISA, fluorescence- or radiolabelling techniques, QCM, and ellipsometry. In the present work we investigated how the common anticoagulants heparin, dalteparin, fondaparinux and sodium citrate affected the binding of anti-complement factor 3c (anti-C3c) on a model complement activator surface, immobilised IgG, after incubation in human blood serum. The results show, as expected, that different anticoagulants affect the antibody binding differently. Increasing amounts of heparin, dalteparin and sodium citrate in normal serum resulted in a decreasing anti-C3c binding. The antibody deposition was not sensitive for the fondaparinux concentration. Surprisingly high concentrations of anti-coagulantia were needed to completely eradicate the antibody binding. Experiments in EGTA-serum showed that anticoagulants interfered directly with both the classical and alternative pathways. Control C3a-des arg ELISA measurements show that the lowered antibody surface binding was not a result of complement depletion in serum. Kallikrein generation by hydrophilic glass surfaces was not affected by high anticoagulant concentrations. PMID:18006286

  8. MPGN II--genetically determined by defective complement regulation?

    PubMed

    Licht, Christoph; Schlötzer-Schrehardt, Ursula; Kirschfink, Michael; Zipfel, Peter F; Hoppe, Bernd

    2007-01-01

    MPGN II is a rare disease which is characterized by complement containing deposits within the GBM. The disease is characterized by functional impairment of the GBM causing progressive loss of renal function eventually resulting in end stage renal disease. It now becomes evident that in addition to C3NeF, which inhibits the inactivation of the alternative C3 convertase C3bBb, different genetically determined factors are also involved in the pathogenesis of MPGN II. These factors though different from C3NeF also result in defective complement regulation acting either through separate pathways or synergistically with C3NeF. Following the finding of MPGN II in Factor H deficient animals, patients with MPGN II were identified presenting with an activated complement system caused by Factor H deficiency. Factor H gene mutations result in a lack of plasma Factor H or in a functional defect of Factor H protein. Loss of Factor H function can also be caused by inactivating Factor H autoantibodies, C3 mutations preventing interaction between C3 and Factor H, or autoantibodies against C3. Identification of patients with MPGN II caused by defective complement control may allow treatment by replacement of the missing factor via plasma infusion, thus possibly preventing or at least delaying disease progress. PMID:17024390

  9. Inhibitors of C5 complement enhance vaccinia virus oncolysis.

    PubMed

    Magge, D; Guo, Z S; O'Malley, M E; Francis, L; Ravindranathan, R; Bartlett, D L

    2013-06-01

    Genetically engineered tumor-selective vaccinia virus (VV) has been demonstrated to be a highly effective oncolytic agent, but immune clearance may limit its therapeutic potential. As previously demonstrated, immunosuppression can lead to significant enhancement of viral recovery and therapeutic effect, but the magnitude of complement-mediated viral inactivation has not been fully elucidated and warrants further investigation. Using fluorescent microscopy and quantitative plaque assays, we have determined complement's key role in viral clearance and its multi-faceted means to pathogen destruction. Complement can lead to direct viral destruction and inhibition of viral uptake into cells, even in the absence of anti-vaccinia antibodies. Our data demonstrate C5 to be integral to the clearance pathway, and its inhibition by Staphylococcal superantigen-like protein leads to a 90-fold and 150-fold enhancement of VV infectivity in both the presence and absence of anti-VV antibodies, respectively. This study suggests that complement inhibition may reduce vaccinia viral neutralization and may be critical to future in vivo work. PMID:23661042

  10. Two Distinct Jacalin-Related Lectins with a Different Specificity and Subcellular Location Are Major Vegetative Storage Proteins in the Bark of the Black Mulberry Tree1

    PubMed Central

    Van Damme, Els J.M.; Hause, Bettina; Hu, Jialiang; Barre, Annick; Rougé, Pierre; Proost, Paul; Peumans, Willy J.

    2002-01-01

    Using a combination of protein isolation/characterization and molecular cloning, we have demonstrated that the bark of the black mulberry tree (Morus nigra) accumulates large quantities of a galactose-specific (MornigaG) and a mannose (Man)-specific (MornigaM) jacalin-related lectin. MornigaG resembles jacalin with respect to its molecular structure, specificity, and co- and posttranslational processing indicating that it follows the secretory pathway and eventually accumulates in the vacuolar compartment. In contrast, MornigaM represents a novel type of highly active Man-specific jacalin-related lectin that is synthesized without signal peptide or other vacuolar targeting sequences, and accordingly, accumulates in the cytoplasm. The isolation and cloning, and immunocytochemical localization of MornigaG and MornigaM not only demonstrates that jacalin-related lectins act as vegetative storage proteins in bark, but also allows a detailed comparison of a vacuolar galactose-specific and a cytoplasmic Man-specific jacalin-related lectin from a single species. Moreover, the identification of MornigaM provides the first evidence, to our knowledge, that bark cells accumulate large quantities of a cytoplasmic storage protein. In addition, due to its high activity, abundance, and ease of preparation, MornigaM is of great potential value for practical applications as a tool and bioactive protein in biological and biomedical research. PMID:12376642

  11. Complement Factors and their G Protein Coupled Receptors in Neuroprotection and Neurodegeneration

    PubMed Central

    Yanamadala, Vijay; Friedlander, Robert M.

    2010-01-01

    Acute neurodegeneration is associated with high morbidity and mortality, and there are few effective treatments. Inflammation is central to the process of neuronal death, and within this field, the roles of the complement cascade have proven to be complex. The complement cascade is involved in triggering cell death and recruiting inflammatory cells to sites of inflammation, including the brain. However, complement might also have important neuroprotective roles that are only now coming to light. Recent evidence suggests that targeted activation of complement may be a potential avenue for treatment of stroke and other acute neurodegenerative diseases. Herein, we describe these novel neuroprotective roles of the complement cascade, focusing on signaling pathways that may be therapeutically targetable in acute neuronal injury. PMID:20116331

  12. Complement the hemostatic system: an intimate relationship.

    PubMed

    Weitz, Ilene Ceil

    2014-05-01

    The complement system is important part of our innate immune system and interacts directly with the hemostatic system. Disorders of complement activation or dysregulation resulting in excess complement generation, such as Paroxysmal Nocturnal Hemoglobinuria (PNH), atypical Hemolytic uremic Syndrome (aHUS) and antiphospholipid syndrome (APLS) have been associated with significant thrombophilia. Terminal Complement (C5b-9) deposition on endothelial and tumor cell membranes has also been reported in a variety of cancer. Recent developments in complement inhibition have given us new insights into the mechanism of thrombosis in these disorders. PMID:24862131

  13. Production and characterization of the B chains of mistletoe toxic lectins

    Microsoft Academic Search

    O. J. Sudarkina; A. G. Kurmanova; J. V. Kozlov

    2007-01-01

    Mistletoe toxic lectins consist of two polypeptide chains: an enzymatically active A chain, which is a toxic component, and\\u000a a disulfide-bonded B chain, which confers the lectin properties on the total molecule. Mistletoe leaves contain three toxic\\u000a lectins encoded by three genes. The B chains of these lectins were overproduced in Escherichia coli in a soluble form. The recombinant proteins

  14. Lectins binding during alloxan-induced diabetes in rat soleus muscle

    Microsoft Academic Search

    Nursel Gül; Suna Cebesoy; Nesrin Özsoy

    Membrane structural changes of soleus muscle of alloxan-diabetic rats were detected with a panel of six biotinylated lectins. Samples of muscles were obtained from normal and diabetic rats. The biotinylated lectins in staining were detected by avidin-peroxidase complex. Lectin stainning of soleus muscle cryostat sections from alloxan-diabetic rats were compared with similar cryostat sections from normal rats. All lectins were

  15. Quantitation of two endogenous lactose-inhibitable lectins in embryonic and adult chicken tissues

    Microsoft Academic Search

    ERIC C. BEYER; SAMUEL H. BARONDES

    1982-01-01

    Two lactose-binding lectins from chicken tissues, chicken-lactose-lectin-I (CLL-I) and chicken-lactose-lectin-II (CLL-II) were quantified with a radioimmunoassay in extracts of a number of developing and adult chicken tissues. Both lectins could be measured in the same extract without separation, because they showed no significant immunological cross- reactivity. Many embryonic and adult tissues, including brain, heart, intestine, kidney, liver, lung, muscle, pancreas,

  16. The effects of natural and hybrid lectins on the legume-rhizobium interactions

    Microsoft Academic Search

    Al. Kh. Baimiev; I. I. Gubaidullin; An. Kh. Baimiev; A. V. Chemeris

    2009-01-01

    The effects of hybrid lectins—full-sized pea Pisum sativum lectin (PSL) with the carbohydrate-binding region of white melilot Melilotus albus lectin or wild licorice Astragalus glycyphyllos lectin substituted for the corresponding PSL region (PSL\\/MAL and PSL\\/AGL, correspondingly)—on the legume-rhizobium symbiosis\\u000a were studied. The treatment of the Rhizobium leguminosarum bv. viciae in the alfalfa (Medicago sativa) rhizosphere with PSL induced formation of

  17. The Semantics of Complementation in English: A Cognitive Semantic Account of Two English Complement Constructions

    ERIC Educational Resources Information Center

    Smith, Michael B.

    2009-01-01

    Studies on complementation in English and other languages have traditionally focused on syntactic issues, most notably on the constituent structures of different complement types. As a result, they have neglected the role of meaning in the choice of different complements. This paper investigates the semantics of complementation within the…

  18. Overview of Complement Activation and Regulation

    PubMed Central

    Noris, Marina; Remuzzi, Giuseppe

    2013-01-01

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

  19. Peripheral challenge with a viral mimic upregulates expression of the complement genes in the hippocampus.

    PubMed

    Michalovicz, Lindsay T; Lally, Brent; Konat, Gregory W

    2015-08-15

    Peripheral challenge with a viral mimetic, polyinosinic-polycytidylic acid (PIC) induces hippocampal hyperexcitability in mice. Here, we characterized this hippocampal response through a whole genome transcriptome analysis. Intraperitoneal injection of PIC resulted in temporal dysregulation of 625 genes in the hippocampus, indicating an extensive genetic reprogramming. The bioinformatics analysis of these genes revealed the complement pathway to be the most significantly activated. The gene encoding complement factor B (CfB) exhibited the highest response, and its upregulation was commensurate with the development of hyperexcitability. Collectively, these results suggest that the induction of hippocampal hyperexcitability may be mediated by the alternative complement cascades. PMID:26198930

  20. Cloning and characterization of the lectin cDNA clones from onion, shallot and leek

    Microsoft Academic Search

    Els J. M. Damme; Koen Smeets; Iris Engelborghs; Helen Aelbers; Jan Balzarini; Arpad Pusztai; Fred Leuven; Irwin J. Goldstein; Willy J. Peumans

    1993-01-01

    Characterization of the lectins from onion (Allium cepa), shallot (A. ascalonicum) and leek (A. porrum) has shown that these lectins differ from previously isolated Alliaceae lectins not only in their molecular structure but also in their ability to inhibit retrovirus infection of target cells.

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

    Microsoft Academic Search

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

    2006-01-01

    A set of 14 plant lectins was screened in a binary choice bioassay for inhibitory activity on cowpea weevil Callosobruchus maculatus (F.) oviposition. Coating of chickpea seeds (Cicer arietinum L.) with a 0.05% (w\\/v) solution of plant lectins caused a significant reduction in egg laying. Control experiments with heat inactivated lectin and BSA indicated that the observed deterrent effects are

  2. Phenotypic Variation of Helicobacter pylori Isolates from Geographically Distinct Regions Detected by Lectin Typing

    Microsoft Academic Search

    Sean O. Hynes; Nathalie Broutet; Torkel Wadstrom; Marika Mikelsaar; Paul W. O'Toole; John Telford; Lars Engstrand; Shigeru Kamiya; Andreas F. Mentis; Anthony P. Moran

    2002-01-01

    A total of 309 Helicobacter pylori isolates from 18 different countries were analyzed with a previously developed lectin typing system. The system was developed by using a proteolytic pretreatment to enhance the carbohydrate fraction of the sample. Four lectins from Ulex europaeus, Lotus tetragonolobus, Erythrina cristigali, and Triticum vulgaris were used to type the strains. The lectins were chosen for

  3. 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

  4. NMR, Molecular Modeling, and Crystallographic Studies of Lentil Lectin-Sucrose Interaction*

    E-print Network

    Hamelryck, Thomas

    NMR, Molecular Modeling, and Crystallographic Studies of Lentil Lectin-Sucrose Interaction- ing site of lentil lectin have been characterized through elucidation of a crystalline complex at 1, and molecular modeling. In the crys- tal, the lentil lectin dimer binds one sucrose molecule per monomer

  5. Lectins: A Possible Basis for Specificity in the Rhizobium-Legume Root Nodule Symbiosis

    Microsoft Academic Search

    B. B. Bohlool; E. L. Schmidt

    1974-01-01

    Soybean lectin labeled with fluorescein isothiocyanate combined specifically with all but 3 of 25 strains of the soybean-nodulating bacterium Rhizobium japonicum. The lectin did not bind to any of 23 other strains representative of rhizobia that do not nodulate soybeans. The evidence suggests that an interaction between legume lectins and Rhizobium cells may account for the specificity expressed between rhizobia

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

    PubMed

    Chan, Yau Sang; Ng, Tzi Bun

    2015-01-01

    Bauhinia variegata var. variegata seeds are rich in proteins. Previously, one of the major storage proteins of the seeds was found to be a trypsin inhibitor that possessed various biological activities. By using another purification protocol, a glucoside- and galactoside-binding lectin that demonstrated some differences from the previously reported B. variegata lectin could be isolated from the seeds. It involved affinity chromatography on Affi-gel blue gel, ion exchange chromatography on Q-Sepharose and Mono Q, and also size exclusion chromatography on Superdex 75. The lectin was not retained on Affi-gel blue gel but interacted with Q-Sepharose. The lectin was a 64-kDa protein with two 32-kDa subunits. It had low thermostability (stable up to 50 °C) and moderate pH stability (stable in pH 3-10). It exhibited anti-proliferative activity on nasopharyngeal carcinoma HONE1 cells with an IC50 of 12.8 ?M after treatment for 48 h. It also slightly inhibited the growth of hepatoma HepG2 cells. The lectin may have potential in aiding cancer treatments. PMID:25240852

  7. 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

  8. 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

  9. The role of lectins in blood group serology.

    PubMed

    Judd, W J

    1980-01-01

    Many lectins display blood group activity, and extracts from Dolichos biflorus (anti-A1), Ulex europaeus (anti-H), and Vicia graminea (anti-N) seeds provide an alternative to human sera as a source of blood-typing reagents. However, the major application of lectins in blood group serology undoubtedly lies in the recognition and elucidation of red celll polyagglutination. In this respect, lectins from Arachis hypogaea (anti-T/Tk), Salvia sclarea (anti-Tn). Salvia horminum (anti-Tn + Cad). Dolichos biflorus (anti-Tn/Cad) Glycine max, and the N-acetyl-D-glucosminyl-binding lectin, BS II (anti-Tk) from Bandeiraea simplicifolia seeds, provide an invaluable source of reagents for use in investigative immunohemotology. Because of their specific carbohydrate-binding properties, lectins have also been used as probes in studies on the topography of the red cell surface. This latter appliction has provided much information on the structure of the MN, T, and Tn red cell surface receptors and has aided in defining the red cell membrane abnormalities associated with certain uncommon phenotypes within the MN blood group system. PMID:6998652

  10. Mannan-Binding Lectin in Cardiovascular Disease

    PubMed Central

    Cedzy?ski, Maciej

    2014-01-01

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

  11. Signaling by myeloid C-type lectin receptors in immunity and homeostasis

    PubMed Central

    Sancho, David; Reis e Sousa, Caetano

    2015-01-01

    Myeloid cells are key drivers of physiological responses to pathogen invasion or tissue damage. Members of the C-type lectin receptor (CLR) family stand out among the specialized receptors utilized by myeloid cells to orchestrate these responses. CLR ligands include carbohydrate, protein and lipid components of both pathogens and self, which variably trigger endocytic, phagocytic, pro-inflammatory or anti-inflammatory reactions. These varied outcomes rely on a versatile system for CLR signaling that includes tyrosine based motifs that recruit kinases, phosphatases or endocytic adaptors, as well as non-tyrosine based signals that modulate the activation of other pathways or couple to the uptake machinery. Here, we review the signaling properties of myeloid CLRs and how they impact the role of myeloid cells in innate and adaptive immunity. PMID:22224766

  12. Complement activation in factor D-deficient mice

    PubMed Central

    Xu, Yuanyuan; Ma, Minghe; Ippolito, Gregory C.; Schroeder, Harry W.; Carroll, Michael C.; Volanakis, John E.

    2001-01-01

    To assess the contribution of the alternative pathway in complement activation and host defense and its possible role in the regulation of systemic energy balance in vivo, factor D-deficient mice were generated by gene targeting. The mutant mice have no apparent abnormality in development and their body weights are similar to those of factor D-sufficient littermates. Complement activation could not be initiated in the serum of deficient mice by the alternative pathway activators rabbit erythrocytes and zymosan. Surprisingly, injection of cobra venom factor (CVF) caused a profound and reproducible reduction in serum C3 levels, whereas, as expected, there was no C3 reduction in factor B-deficient mice treated similarly. Studies of C3 and factor B activation in vitro by CVF demonstrated that in factor D-deficient serum the ? chain of C3 was cleaved gradually over a period of 60 min without detectable cleavage of factor B. CVF-dependent C3 cleavage in the deficient serum required the presence of Mg2+, whereas in normal mouse serum the presence of divalent cations was not required. These results suggest that in mouse proteolytic cleavage of factor B by factor D is not an absolute requirement for the zymogen to active enzyme conformational transition of CVF-bound factor B. Kinetics of opsonization of Streptococcus pneumoniae by C3 fragments was much slower in factor D-deficient serum, suggesting a significant contribution of the alternative pathway to antibacterial host defense early after infection. PMID:11724962

  13. Complement System Part II: Role in Immunity

    PubMed Central

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

    2015-01-01

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

  14. Lectin from Griffonia simplicifolia identifies an immature-appearing subpopulation of sensory hair cells in the avian utricle

    Microsoft Academic Search

    Mark E. Warchol; Fay Simons

    2001-01-01

    The sensory hair cells of the inner ear are coated with a variety of glycoproteins and glycolipids which can be identified by the binding of specific lectins. The present study examined the binding patterns of three lectins–Wheat Germ Agglutinin, Peanut Agglutinin, and lectin from Griffonia simplicifolia (Isoform B4)–in the avian utricle. Each of the lectins exhibited a distinct pattern of

  15. Lectin biosensing using digital analysis of Ru(II)-glycodendrimers.

    PubMed

    Kikkeri, Raghavendra; Grünstein, Dan; Seeberger, Peter H

    2010-08-01

    A novel, digital, single-operation analytical method to study glycodendrimer-lectin interactions is described. Robust, highly fluorescent derivatives of tris(bipyridine)ruthenieum(II) ([Ru(bipy)(3)](2+)) bearing 2, 4, 6, or 18 mannose or galactose units were designed to perform molecular logic operations. Inputs for these systems were pH, N,N'-4,4'-bis(benzyl-2-boronic acid)bipyridinium dibromide, and different lectins (concanavalin A, Galantus nivalis agglutinin, and asialoglycoprotein). The relative change in fluorescence quantum yield of the Ru(II)-glycodendrimers served as output. Together, the fluorescent emission readout, the logic analysis of the photoinduced electron transfer, and the optical behavior provide a single-step method to quickly screen a glycodendrimer library and select the best dendrimer model for studying carbohydrate-lectin interactions. PMID:20662498

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

    PubMed

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

    2013-11-01

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

  17. Effect of lectins from Diocleinae subtribe against oral Streptococci.

    PubMed

    Cavalcante, Theodora Thays Arruda; Anderson Matias da Rocha, Bruno; Alves Carneiro, Victor; Vassiliepe Sousa Arruda, Francisco; Fernandes do Nascimento, Antônia Sâmia; Cardoso Sá, Nairley; do Nascimento, Kyria Santiago; Sousa Cavada, Benildo; Holanda Teixeira, Edson

    2011-01-01

    Surface colonization is an essential step in biofilm development. The ability of oral pathogens to adhere to tooth surfaces is directly linked with the presence of specific molecules at the bacterial surface that can interact with enamel acquired pellicle ligands. In light of this, the aim of this study was to verify inhibitory and antibiofilm action of lectins from the Diocleinaesubtribe against Streptococcus mutans and Streptococcus oralis. The inhibitory action against planctonic cells was assessed using lectins from Canavaliaensi formis (ConA), Canavalia brasiliensis (ConBr), Canavalia maritima (ConM), Canavalia gladiata (CGL) and Canavalia boliviana (ConBol). ConBol, ConBr and ConM showed inhibitory activity on S. mutans growth. All lectins, except ConA, stimulated significantly the growth of S. oralis. To evaluate the effect on biofilm formation, clarified saliva was added to 96-well, flat-bottomed polystyrene plates, followed by the addition of solutions containing 100 or 200 µg/mL of the selected lectins. ConBol, ConM and ConA inhibited the S. mutans biofilms. No effects were found on S. oralis biofilms. Structure/function analysis were carried out using bioinformatics tools. The aperture and deepness of the CRD (Carbohydrate Recognition Domain) permit us to distinguish the two groups of Canavalia lectins in accordance to their actions against S. mutans and S. oralis. The results found provide a basis for encouraging the use of plant lectins as biotechnological tools in ecological control and prevention of caries disease. PMID:21525793

  18. Complement in Action: An Analysis of Patent Trends from 1976 Through 2011

    PubMed Central

    Yang, Kun; DeAngelis, Robert A.; Reed, Janet E.; Ricklin, Daniel; Lambris, John D.

    2012-01-01

    Complement is an essential part of the innate immune response. It interacts with diverse endogenous pathways and contributes to the maintenance of homeostasis, the modulation of adaptive immune responses, and the development of various pathologies. The potential usefulness, in both research and clinical settings, of compounds that detect or modulate complement activity has resulted in thousands of publications on complement-related innovations in fields such as drug discovery, disease diagnosis and treatment, and immunoassays, among others. This study highlights the distribution and publication trends of patents related to the complement system that were granted by the United States Patent and Trademark Office from 1976 to the present day. A comparison to complement-related documents published by the World Intellectual Property Organization is also included. Statistical analyses revealed increasing diversity in complement-related research interests over time. More than half of the patents were found to focus on the discovery of inhibitors; interest in various inhibitor classes exhibited a remarkable transformation from chemical compounds early on to proteins and antibodies in more recent years. Among clinical applications, complement proteins and their modulators have been extensively patented for the diagnosis and treatment of eye diseases (especially age-related macular degeneration), graft rejection, cancer, sepsis, and a variety of other inflammatory and immune diseases. All of the patents discussed in this chapter, as well as those from other databases, are available from our newly constructed complement patent database: www.innateimmunity.us/patent. PMID:22990712

  19. Factors affecting the binding of lectins to normal human skin.

    PubMed

    Bell, C M; Skerrow, C J

    1984-11-01

    Factors affecting the binding of a wide range of lectins to normal human skin were examined in order to evaluate current discrepancies in the literature. The profile of specific binding characteristic for each lectin was found to be variously influenced by the source of conjugate, tissue-processing method, the effectiveness of saccharide inhibitors, and by individual and minor body site variations. Most significantly, the use of routine histological processing not only greatly reduced binding intensity overall but also altered the binding pattern. PMID:6548640

  20. Complementation Constructions for Nondeterministic Automata on Infinite Words

    E-print Network

    Kupferman, Orna

    Complementation Constructions for Nondeterministic Automata on Infinite Words Orna Kupferman1 Abstract. The complementation problem for nondeterministic automata on in- finite words has numerous verification problems are reduced, involves complementation. Traditional optimal complementation constructions

  1. Complementation Constructions for Nondeterministic Automata on Infinite Words

    E-print Network

    Vardi, Moshe Y.

    Complementation Constructions for Nondeterministic Automata on Infinite Words Orna Kupferman 1; vardi Abstract. The complementation problem for nondeterministic automata on in­ finite words has many verification problems are reduced, involves complementation. Traditional optimal complementation

  2. Crystal structure of a lectin from Canavalia maritima (ConM) in complex with trehalose and maltose reveals relevant mutation in ConA-like lectins

    Microsoft Academic Search

    Plínio Delatorre; Bruno A. M. Rocha; Carlos A. A. Gadelha; Tatiane Santi-Gadelha; Joăo B. Cajazeiras; Emmanuel P. Souza; Kyria S. Nascimento; Valder N. Freire; Alexandre H. Sampaio; Walter F. Azevedo; Benildo S. Cavada

    2006-01-01

    The crystal structure of Canavalia maritima lectin (ConM) complexed with trehalose and maltose revealed relevant point mutations in ConA-like lectins. ConM with the disaccharides and other ConA-like lectins complexed with carbohydrates demonstrated significant differences in the position of H-bonds. The main difference in the ConM structure is the replacement of Pro202 by Ser202, a residue that promotes the approximation of

  3. ASSIGNACI DEL COMPLEMENT BSIC DOCENT CONVOCATRIA 2010

    E-print Network

    Politècnica de Catalunya, Universitat

    ASSIGNACI� DEL COMPLEMENT B�SIC DOCENT CONVOCAT�RIA 2010 Acord núm.113/2011 del Consell de Govern pel qual s'aprova l'assignació del complement bàsic docent. Convocatòria 2010. · Document aprovat per'Avaluació Juliol de 2011 ASSIGNACI� DEL COMPLEMENT B�SIC DOCENT CONVOCAT�RIA 2010 Antecedents El Reial Decret 1086

  4. The ancient origin of the complement system

    Microsoft Academic Search

    Yong Zhu; Saravanan Thangamani; Bow Ho; Jeak Ling Ding

    2005-01-01

    The complement system has been thought to originate exclusively in the deuterostomes. Here, we show that the central complement components already existed in the primitive protostome lineage. A functional homolog of vertebrate complement 3, CrC3, has been isolated from a 'living fossil', the horseshoe crab (Carcinoscorpius rotun- dicauda). CrC3 resembles human C3 and shows closest homology to C3 sequences of

  5. Cerebrovascular accident clinical pathway.

    PubMed

    Wilkinson, G; Parcell, M; MacDonald, A

    2000-01-01

    The cerebrovascular accident (CVA) clinical pathway project was selected to complement the work already underway within the West Moreton Health Services District such as the development of a continuum of care model, revision of work practices to complement the new hospital redevelopment and encouraging team and evidence-based approaches to problem solving. Specific objectives were set for the project along with a detailed evaluation plan. A steering group was convened to run the project and a full time project officer was appointed. At the end of the 12 month period all the objectives were met. Specific achievements included a reduction in the overall average length of stay for those patients who experience CVA, improved clinical outcomes and a more effective use of resources. Quality of care has been improved through the preparation of specialized clinical pathway documentation, education packages, patient surveys, focus groups, independent reviews and benchmarking. Complementing these measures has been a series of process changes and environmental modifications. Furthermore, good working relationships have been established with private sector providers of health care and other external bodies. The development of the CVA clinical pathway at the Ipswich Hospital has meant timely referrals and a streamlined assessment and referral process to get patients into rehabilitation sooner. It has promoted good communication between, and recognition of, the professional roles of various team members and has put the patient back at the centre of the care process. PMID:11057994

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

    PubMed

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

    2015-01-01

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

  7. Purification and Characterization of Two Major Lectins from Araucaria brasiliensis syn. Araucaria angustifolia Seeds (Pinhăo) 1

    PubMed Central

    Datta, Pradip K.; Figueroa, Maria O. D. C. R.; Lajolo, Franco M.

    1991-01-01

    Two major lectins (lectin I and lectin II) were purified to homogeneity from the seeds of Araucaria brasiliensis (Gymnospermae). The purity of the lectins was confirmed by polyacrylamide gel electrophoresis, isoelectric focusing, and high performance liquid chromatography. They are glycoproteins in nature containing 6.3 and 2.9%, respectively, of neutral sugar and have absorption coefficients of 3.8 and 4.7, respectively, at 280 nanometers. The molecular weights of both lectins obtained by gel filtration on Sephacryl S-400 were equal: 200,000. After dissociation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, molecular weights were 20,000 and 34,000, respectively, for lectin I and lectin II, suggesting they are decameric and hexameric in nature. The amino acid composition of both lectins showed little difference, but both had high amounts of acidic amino acids and lacked methionine in their molecule. The carbohydrate binding specificity of lectins was directed towards mannose, glucose, and their oligomers. High inhibitory activity was also found with thyroglobulin. The erythroagglutinating activity of the lectins was enhanced in the presence of high-molecular-weight substances both at 37 and 4°C. Divalent cations do not appear to be essential for activity. They maintained their agglutinating activity over a broad but different range of pH: 5.5 to 7.5 and 6.5 to 7.5, respectively. Both lectins agglutinated erythrocytes of human ABO blood types equally well. ImagesFigure 2Figure 3 PMID:16668523

  8. Complement and dysbiosis in periodontal disease

    PubMed Central

    Hajishengallis, George; Lambris, John D.

    2012-01-01

    Signaling crosstalk between complement and Toll-like receptors (TLRs) normally serves to coordinate host immunity. However, the periodontal bacterium Porphyromonas gingivalis expresses C5 convertase-like enzymatic activity and adeptly exploits complement-TLR crosstalk to subvert host defenses and escape elimination. Intriguingly, this defective immune surveillance leads to the remodeling of the periodontal microbiota to a dysbiotic state that causes inflammatory periodontitis. Understanding the mechanisms by which P. gingivalis modulates complement function to cause dysbiosis offers new targets for complement therapeutics. PMID:22964237

  9. 21 CFR 866.4100 - Complement reagent.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

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

    SciTech Connect

    Johnson, John B.; Capraro, Gerald A. [Department of Microbiology and Immunology, Wake Forest University, School of Medicine, Winston-Salem, NC 27157-1064 (United States); Parks, Griffith D. [Department of Microbiology and Immunology, Wake Forest University, School of Medicine, Winston-Salem, NC 27157-1064 (United States)], E-mail: gparks@wfubmc.edu

    2008-06-20

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

  11. Mannan-binding lectin reduces CpG DNA-induced inflammatory cytokine production by human monocytes.

    PubMed

    Tang, Yuan; Ma, Di; Ming, Siqi; Zhang, Liyun; Zhou, Jia; Shan, Guiqiu; Chen, Zhengliang; Lu, Xiao; Zuo, Daming

    2015-04-01

    Mannan-binding lectin (MBL) belongs to the collectin family and functions as an opsonin that can also initiate complement activation. Our previous study showed that MBL serves as a double-stranded RNA binding protein that attenuates polyriboinosinic-polyribocytidylic acid-induced TLR3 activation. Prompted by these findings, in the present study cross-talk between MBL and CpG-DNA-induced TLR9 activation was investigated. Here, it was found that MBL also interacts with the TLR9 agonist, CpG oligodeoxynucleotide (CpG-ODN), in a calcium-dependent manner. Purified MBL protein suppressed activation of nuclear factor-kappa B signaling and subsequent production of proinflammatory cytokines from human monocytes induced by CpG-ODN 2006. These observations indicate that MBL can down-regulate CpG DNA-induced TLR9 activation, emphasizing the importance of understanding the interaction of MBL with TLR agonist in host immune defense. PMID:25664598

  12. 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

  13. The DNA helicase BRIP1 is defective in Fanconi anemia complementation group J

    Microsoft Academic Search

    Marieke Levitus; Quinten Waisfisz; Barbara C Godthelp; Yne de Vries; Shobbir Hussain; Wouter W Wiegant; Elhaam Elghalbzouri-Maghrani; Jűrgen Steltenpool; Martin A Rooimans; Gerard Pals; Fré Arwert; Christopher G Mathew; Ma?gorzata Z Zdzienicka; Kevin Hiom; Johan P De Winter; Hans Joenje

    2005-01-01

    The protein predicted to be defective in individuals with Fanconi anemia complementation group J (FA-J), FANCJ, is a missing component in the Fanconi anemia pathway of genome maintenance. Here we identify pathogenic mutations in eight individuals with FA-J in the gene encoding the DEAH-box DNA helicase BRIP1, also called FANCJ. This finding is compelling evidence that the Fanconi anemia pathway

  14. Lack of the lectin-like domain of thrombomodulin worsens Shiga toxin-associated hemolytic uremic syndrome in mice.

    PubMed

    Zoja, Carlamaria; Locatelli, Monica; Pagani, Chiara; Corna, Daniela; Zanchi, Cristina; Isermann, Berend; Remuzzi, Giuseppe; Conway, Edward M; Noris, Marina

    2012-10-01

    Shiga toxin (Stx)-producing Escherichia coli is a primary cause of diarrhea-associated hemolytic uremic syndrome (HUS), a disorder of thrombocytopenia, microangiopathic hemolytic anemia, and acute renal failure. The pathophysiology of renal microvascular thrombosis in Stx-HUS is still ill-defined. Based on evidence that abnormalities in thrombomodulin (TM), an anticoagulant endothelial glycoprotein that modulates complement and inflammation, predispose to atypical HUS, we assessed whether impaired TM function may adversely affect evolution of Stx-HUS. Disease was induced by coinjection of Stx2/LPS in wild-type mice (TM(wt/wt)) and mice that lack the lectin-like domain of TM (TM(LeD/LeD)), which is critical for its anti-inflammatory and cytoprotective properties. After Stx2/LPS, TM(LeD/LeD) mice exhibited more severe thrombocytopenia and renal dysfunction than TM(wt/wt) mice. Lack of lectin-like domain of TM resulted in a stronger inflammatory reaction after Stx2/LPS with more neutrophils and monocytes/macrophages infiltrating the kidney, associated with PECAM-1 and chemokine upregulation. After Stx2/LPS, intraglomerular fibrin(ogen) deposits were detected earlier in TM(LeD/LeD) than in TM(wt/wt) mice. More abundant fibrin(ogen) deposits were also found in brain and lungs. Under basal conditions, TM(LeD/LeD) mice exhibited excess glomerular C3 deposits, indicating impaired complement regulation in the kidney that could lead to local accumulation of proinflammatory products. TM(LeD/LeD) mice with HUS had a higher mortality rate than TM(wt/wt) mice. If applicable to humans, these findings raise the possibility that genetic or acquired TM defects might have an impact on the severity of microangiopathic lesions after exposure to Stx-producing E. coli infections and raise the potential for using soluble TM in the treatment of Stx-HUS. PMID:22942429

  15. The development of atypical hemolytic uremic syndrome depends on complement C5.

    PubMed

    de Jorge, Elena Goicoechea; Macor, Paolo; Paixăo-Cavalcante, Danielle; Rose, Kirsten L; Tedesco, Franco; Cook, H Terence; Botto, Marina; Pickering, Matthew C

    2011-01-01

    Gene variants in the alternative pathway of the complement system strongly associate with atypical hemolytic uremic syndrome (aHUS), presumably by predisposing to increased complement activation within the kidney. Complement factor H (CFH) is the major regulator of complement activation through the alternative pathway. Factor H-deficient mice transgenically expressing a mutant CFH protein (Cfh(-/-).FH?16-20) that functionally mimics the CFH mutations reported in aHUS patients spontaneously develop thrombotic microangiopathy. To investigate the role of complement C5 activation in this aHUS model, we generated C5-deficient Cfh(-/-).FH?16-20 mice. Both C5-sufficient and C5-deficient Cfh(-/-).FH?16-20 mice had abnormal C3 deposition within the kidney, but spontaneous aHUS did not develop in any of the C5-deficient mice. Furthermore, although Cfh(-/-).FH?16-20 animals demonstrated marked hypersensitivity to experimentally triggered renal injury, animals with concomitant C5 deficiency did not. These data demonstrate a critical role for C5 activation in both spontaneous aHUS and experimentally triggered renal injury in animals with defective complement factor H function. This study provides a rationale to investigate therapeutic inhibition of C5 in human aHUS. PMID:21148255

  16. Complement monitoring of Pluronic 127 gel and micelles: suppression of copolymer-mediated complement activation by elevated serum levels of HDL, LDL, and apolipoproteins AI and B-100.

    PubMed

    Hamad, Islam; Hunter, A Christy; Moghimi, S Moein

    2013-09-10

    Poloxamer 407 is a non-ionic polyethylene oxide (PEO)/polypropylene oxide (PPO) block copolymer, which exhibits reversible thermogelation properties. Poloxamer gel has attracted many applications for controlled release of therapeutic agents as well as in surgical interventions such as controlled vascular occlusion. We show that poloxamer gel can trigger the complement system, which is an integral part of innate immunity and its inadvertent activation can induce clinically significant anaphylaxis. Complement activation by the poloxamer gel is through the alternative pathway, but material transformations from gel to the solution state further incite complement through calcium-sensitive pathways, where a role for C1q and antibodies has been eliminated. Poloxamer addition to plasma/serum (at levels above its critical micelle concentration, cmc) induced formation of large and diffused structures, which may have been responsible for triggering complement. Since poloxamer 407 administration has been reported to cause significant changes in plasma cholesterol and triglyceride levels we further examined the role of lipoproteins in poloxamer-mediated complement activation. Our results show a protective role for elevated serum HDL, LDL and their predominant apolipoproteins (apoAI and apoB-100, respectively) on poloxamer-mediated complement activation. Electron microscopy investigations indicated formation of two distinct populations of new structures on mixing of poloxamer (at concentrations above its cmc) with human LDL, which could have played a significant role in regulating complement activation. These observations are in line with the suggested modulatory role of lipoproteins in host defence and inflammatory processes. A better understanding of block copolymer interaction with lipoproteins/apolipoproteins could improve the immune safety of surgical and therapeutic interventions requiring PEO/PPO block copolymers and may provide new insights for combinatorial design of multifunctional copolymers. PMID:23747733

  17. Emerging and Novel Functions of Complement Protein C1q

    PubMed Central

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

    2015-01-01

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

  18. 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.

  19. 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

  20. Lentil lectin effectively induces allotransplantation tolerance in mice.

    PubMed

    Hilgert, I; Horejsí, V; Angelisová, P; Kristofová, H

    1980-03-20

    The interaction of lectins with carbohydrate receptors on the plasma membrane of eukaryotic cells results in a wide variety of biological effects. One effect which has been extensively studied is the stimulation of lymphocytes to blastogenesis and proliferation. High doses of concanavalin A (Con A) and phytohaemagglutinin (PHA) have been shown to activate in vitro regulatory cells capable of suppressing proliferation of other cells in the culture. However, Con A and PHA treatment were used effectively to prolong the survival of skin and heart allografts before it was recognised that some lectins have an activatory effect on suppressor cells in vitro. A possible explanation of these tolerogenic effects is the activation of specific suppressor cells. In this letter we have compared systematically various lectins differing in their carbohydrate specificity and mitogenicity in relation to their ability to induce prolonged skin allograft survival in mice with the aim of selecting the most effective lectin tratment schedule. Some preliminary results of this study have been mentioned in a recent review. PMID:6987530

  1. Pseudomonas Aeruginosa Lectins As Targets for Novel Antibacterials

    PubMed Central

    Grishin, A. V.; Krivozubov, M. S.; Karyagina, A. S.; Gintsburg, A. L.

    2015-01-01

    Pseudomonas aeruginosa is one of the most widespread and troublesome opportunistic pathogens that is capable of colonizing various human tissues and organs and is often resistant to many currently used antibiotics. This resistance is caused by different factors, including the acquisition of specific resistance genes, intrinsic capability to diminish antibiotic penetration into the bacterial cell, and the ability to form biofilms. This situation has prompted the development of novel compounds differing in their mechanism of action from traditional antibiotics that suppress the growth of microorganisms or directly kill bacteria. Instead, these new compounds should decrease the pathogens’ ability to colonize and damage human tissues by inhibiting the virulence factors and biofilm formation. The lectins LecA and LecB that bind galactose and fucose, as well as oligo- and polysaccharides containing these sugars, are among the most thoroughly-studied targets for such novel antibacterials. In this review, we summarize the results of experiments highlighting the importance of these proteins for P. aeruginosa pathogenicity and provide information on existing lectins inhibitors and their effectiveness in various experimental models. Particular attention is paid to the effects of lectins inhibition in animal models of infection and in clinical practice. We argue that lectins inhibition is a perspective approach to combating P. aeruginosa. However, despite the existence of highly effective in vitro inhibitors, further experiments are required in order to advance these inhibitors into pre-clinical studies.

  2. Chronic Low Level Complement Activation within the Eye Is Controlled by Intraocular Complement Regulatory Proteins

    Microsoft Academic Search

    Jeong-Hyeon Sohn; Henry J. Kaplan; Hye-Jung Suk; Puran S. Bora; Nalini S. Bora

    2000-01-01

    PURPOSE. To explore the role of the complement system and complement regulatory proteins in an immune-privileged organ, the eye. METHODS. Eyes of normal Lewis rats were analyzed for the expression of complement regulatory proteins, membrane cofactor protein (MCP), decay-acceleration factor (DAF), membrane inhibitor of reactive lysis (MIRL, CD59), and cell surface regulator of complement (Crry), using immunohis- tochemistry, Western blot

  3. How does the Draft Convention complement

    E-print Network

    Sussex, University of

    How does the Draft Convention complement existing initiatives? HSDC Briefing Paper 2 The Harvard biological or chemical weapons". Resolution 1540 in effect does not require BWC or CWC member States to go to the commission of relevant offences. #12;Page 2 How does the Drat Convention complement existing initiatives

  4. A Two's Complement Parallel Array Multiplication Algorithm

    Microsoft Academic Search

    C. R. Baugh; B. A. Wooley

    1973-01-01

    An algorithm for high-speed, two's complement, m-bit by n-bit parallel array multiplication is described. The two's complement multiplication is converted to an equivalent parallel array addition problem in which each partial product bit is the AND of a multiplier bit and a multiplicand bit, and the signs of all the partial product bits are positive.

  5. Dissecting complement blockade for clinic use.

    PubMed

    Risitano, Antonio M

    2015-01-29

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

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

    PubMed Central

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

    2013-01-01

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

  7. Complement System Part II: Role in Immunity.

    PubMed

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

    2015-01-01

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

  8. 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

  9. Interplay Between Metal Binding and cis\\/trans Isomerization in Legume Lectins: Structural and Thermodynamic Study of P. angolensis Lectin

    Microsoft Academic Search

    Abel Garcia-Pino; Lieven Buts; Lode Wyns; Remy Loris

    2006-01-01

    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

  10. Complement activating properties of monoreactive and polyreactive IgM rheumatoid factors.

    PubMed Central

    Sato, Y; Sato, R; Watanabe, H; Kogure, A; Watanabe, K; Nishimaki, T; Kasukawa, R; Kuraya, M; Fujita, T

    1993-01-01

    OBJECTIVES--To estimate the complement activating properties of monoclonal, monoreactive, and polyreactive IgM rheumatoid factors derived from Epstein-Barr virus transformed B cells isolated from peripheral blood and synovial tissue of patients with rheumatoid arthritis (RA). METHODS--An enzyme linked immunosorbent assay (ELISA) was used to measure the activation of the classical pathway of complement by monoclonal IgM rheumatoid factor. Monoclonal IgM rheumatoid factor was bound to IgG Fc adsorbed onto microtitre plates and then reacted with diluted normal human serum as a source of complement. The activation and binding of C4 were measured with F(ab')2 antibody to human C4. The complement activating property of IgM rheumatoid factor bound to IgG Fc was tentatively expressed as the ratio of the amount of bound C4 to the amount of bound IgM rheumatoid factor. RESULTS--The complement activating property of monoreactive IgM rheumatoid factor was shown to be about three times higher than that of polyreactive IgM rheumatoid factor. CONCLUSIONS--Monoreactive IgM rheumatoid factor with the higher complement activating property would result in a greater degree of complement dependent inflammation and might have a more important pathogenic role in RA than polyreactive IgM rheumatoid factor. Images PMID:8250611

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

    PubMed Central

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

    2015-01-01

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

  12. Complement emerges as a masterful regulator of CNS homeostasis, neural synaptic plasticity and cognitive function.

    PubMed

    Mastellos, Dimitrios C

    2014-11-01

    Growing evidence points to a previously elusive role of complement-modulated pathways in CNS development, neurogenesis and synaptic plasticity. Distinct complement effectors appear to play a multifaceted role in brain homeostasis by regulating synaptic pruning in the retinogeniculate system and sculpting functional neural circuits both in the developing and adult mammalian brain. A recent study by Perez-Alcazar et al. (2014) provides novel insights into this intricate interplay between complement and the dynamically regulated brain synaptic circuitry, by reporting that mice deficient in C3 exhibit enhanced hippocampus-dependent spatial learning and cognitive performance. This behavioral pattern is associated with an impact of C3 on the functional capacity of glutamatergic synapses, supporting a crucial role for complement in excitatory synapse elimination in the hippocampus. These findings add a fresh twist to this rapidly evolving research field, suggesting that discrete complement components may differentially modulate synaptic connectivity by wiring up with diverse neural effectors in different regions of the brain. The emerging role of complement in synaptogenesis and neural network plasticity opens new conceptual avenues for considering complement interception as a potential therapeutic modality for ameliorating progressive cognitive impairment in age-related, debilitating brain diseases with a prominent inflammatory signature. PMID:24975369

  13. Development of a large scale human complement source for use in bacterial immunoassays.

    PubMed

    Brookes, Charlotte; Kuisma, Eeva; Alexander, Frances; Allen, Lauren; Tipton, Thomas; Ram, Sanjay; Gorringe, Andrew; Taylor, Stephen

    2013-05-31

    The serum bactericidal assay is the correlate of protection for meningococcal disease but the use and comparison of functional immunological assays for the assessment of meningococcal vaccines is complicated by the sourcing of human complement. This is due to high levels of immunity in the population acquired through natural meningococcal carriage and means that many individuals must be screened to find donors with suitably low bactericidal titres against the target strain. The use of different donors for each meningococcal strain means that comparisons of assay responses between strains and between laboratories is difficult. We have developed a method for IgG-depletion of 300 ml batches of pooled human lepirudin-derived plasma using Protein G sepharose affinity chromatography that retains complement activity. However, IgG-depletion also removed C1q. This was also eluted from the affinity matrix, concentrated and added to the complement source. The final complement source retained mean alternative pathway activity of 96.8% and total haemolytic activity of 84.2% in four batches. Complement components C3, C5, properdin and factor H were retained following the process and the IgG-depleted complement was shown to be suitable for use in antibody-mediated complement deposition and serum bactericidal activity assays against serogroup B meningococci. The generation of large IgG-depleted batches of pooled human plasma allows for the comparison of immunological responses to diverse meningococcal strain panels in large clinical trials. PMID:23485926

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

    PubMed Central

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

    2015-01-01

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

  15. Analysis of complement C3 deposition and degradation on Klebsiella pneumoniae.

    PubMed

    Albertí, S; Alvarez, D; Merino, S; Casado, M T; Vivanco, F; Tomás, J M; Benedí, V J

    1996-11-01

    The majority of Klebsiella pneumoniae serum-resistant strains activate complement and bind C3b, the opsonic fragment of C3, without C5b-9 formation and bacterial killing. The mechanisms leading to C3b deposition without cell death were studied, and the results indicate that serum-resistant strains activate principally the alternative pathway and that serum-sensitive strains activate both the alternative and classical pathways. Bacterial molecules implicated in C3b deposition are the outer membrane porin proteins and smooth and rough lipopolysaccharides. Porins activate both complement pathways, and the rough lipopolysaccharide activates the classical pathway, causing deposition of C3b in serum-sensitive strains. The smooth lipopolysaccharide of serum-resistant strains activates only the alternative pathway, impeding the binding of C1q to porins (S. Albertí, G. Marqués, S. Camprubí, S. Merino, J. M. Tomás, F. Vivanco, and V. J. Benedí, Infect. Immun. 61:852-860, 1993; S. Albertí, F. Rodríguez-Quinónes, T. Schirmer, G. Rummel, J. M. Tomás, J. P. Rosenbusch, and V. J. Benedí, Infect. Immun. 63:903-910, 1995) and rough lipopolysaccharide molecules and thereby preventing activation of the classical pathway. After its deposition, C3b is quickly degraded to iC3b on both types of strains, but the higher-level deposition of C3b on serum-sensitive strains, resulting from activation of both the alternative and classical complement pathways, supports further complement activation and killing of serum-sensitive strains. PMID:8890232

  16. A role for mannose-binding lectin, a component of the innate immune system in preeclampsia

    PubMed Central

    Than, Nandor Gabor; Romero, Roberto; Erez, Offer; Kusanovic, Juan Pedro; Tarca, Adi L.; Edwin, Samuel S.; Kim, Jung-Sun; Hassan, Sonia S.; Espinoza, Jimmy; Mittal, Pooja; Mazaki-Tovi, Shali; Friel, Lara; Gotsch, Francesca; Vaisbuch, Edi; Camacho, Natalia; Papp, Zoltan

    2008-01-01

    Problem Mannose-binding lectin (MBL) is a pattern-recognition receptor that activates complement and modulates inflammation. Homozygosity for the most common allele of the MBL2 gene associated with high MBL serum concentrations is more prevalent in patients with preeclampsia. The objective of this study was to determine maternal plasma MBL concentrations in normal pregnant women and patients with pre-eclampsia. Method of study This cross-sectional study included normal pregnant women (n=187) and patients with preeclampsia (n=99). Maternal plasma MBL concentrations were determined by ELISA. Results Women with preeclampsia had higher median maternal plasma MBL concentration than normal pregnant women. MBL concentration distribution curves were three-modal, the subintervals in normal pregnancy were low (<143.7), intermediate (143.7–1898.9) and high (>1898.9ng/ml). The proportion of normal pregnant women was larger in the low subinterval, while the proportion of patients with preeclampsia was larger in the high subinterval (p=0.02). Normal pregnant women in the high subinterval had a larger rate of placental underperfusion than those in the low and intermediate subintervals (P = 0.02). Conclusions Median maternal plasma MBL concentration is elevated in patients with preeclampsia and a larger proportion of these patients is in the high subinterval than normal pregnant women, suggesting that this innate immune system component is involved in the mechanisms of disease in preeclampsia. PMID:18727690

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

    PubMed Central

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

    2015-01-01

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

  18. [Complement and its role in immune response].

    PubMed

    Hess, C; Steiger, J U; Schifferli, J A

    1998-03-14

    The complement system as a part of innate immunity is considered to provide rapid tough incomplete antimicrobial activity. However, besides providing a first-line defence, innate immunity plays additional important roles: it initiates and improves the slower, but more specific, acquired immune response. The recognition and destruction of noxious substances, as well as initiation of the acquired immune response, are accompanied by potentially hazardous inflammation. The inflammatory process has thus to be tightly regulated. In this overview, innate immunity and its interactions with acquired immunity are discussed with the main focus on the complement system. Our scientific interests are integrated into the discussion on complement. PMID:9561585

  19. Interactions of the platelets in paroxysmal nocturnal hemoglobinuria with complement. Relationship to defects in the regulation of complement and to platelet survival in vivo.

    PubMed Central

    Devine, D V; Siegel, R S; Rosse, W F

    1987-01-01

    The blood cells of patients with paroxysmal nocturnal hemoglobinuria (PNH) have abnormal interactions with complement. The activity of the alternative pathway C3 convertase on the platelets of 9 out of 19 patients with PNH was elevated. 10 patients had C3 convertase activity within the normal range even though 80-95% of their platelets lacked the complement regulatory protein decay accelerating factor (DAF) that is absent from the affected blood cells in PNH. PNH and normal platelets released factor H when C3 was bound to their surfaces. This may account for the apparent regulation of C3 convertase activity on platelets that lack DAF. The abnormal uptake of the membrane attack complex of complement by PNH III erythrocytes was not seen in PNH platelets. 111Indium-labeled platelet survival times were normal in five of eight patients, which suggests that the lack of the membrane attack complex defect results in normal platelet survival in PNH. Images PMID:2432087

  20. Studies on recombinant single chain Jacalin lectin reveal reduced affinity for saccharides despite normal folding like native Jacalin

    PubMed Central

    Sahasrabuddhe, Anagh A.; Gaikwad, Sushama M.; Krishnasastry, M.V.; Khan, M. Islam

    2004-01-01

    Sugar binding studies, inactivation, unfolding, and refolding of native Jacalin (nJacalin) from Artocarpus integrifolia and recombinant single-chain Jacalin (rJacalin) expressed in Escherichia coli were studied by intrinsic fluorescence and thermal and chemical denaturation approaches. Interestingly, rJacalin does not undergo any proteolytic processing in an E. coli environment. It has 100fold less affinity for methyl-?-galactose (Ka: 2.48 × 102) in comparison to nJacalin (Ka: 1.58 × 104), and it also binds Thomsen-Friedenreich (TF) disaccharide (Gal?1–3GalNAc) with less affinity. Overall sugar binding characteristics of rJacalin are qualitatively similar to that of nJacalin (Galpathways between native and recombinant lectins. The stability of rJacalin is dramatically reduced in the extreme pH range unlike nJacalin. Both lectins do not bind 1-anilino-8-naphthalene sulfonic acid (ANS) in the pH range of 5 to 12 but they do in the pH range of 1–3. Solute quenching studies of the lectin using acrylamide, KI, and CsCl indicated that the tryptophan residues have full accessibility to the neutral quencher and poor accessibility to ionic quenchers. In summary, biophysical and biochemical studies on the native versus recombinant Jacalin suggest that post-translational modification, i.e., the processing of Jacalin into two chains is probably not a prerequisite for sugar binding but may be required for higher affinity. PMID:15557267

  1. Mutational analysis of the pumpkin (Cucurbita maxima) phloem exudate lectin, PP2 reveals Ser-104 is crucial for carbohydrate binding.

    PubMed

    Bobbili, Kishore Babu; Bandari, Shyam; Grobe, Kay; Swamy, Musti J

    2014-07-18

    The pumpkin phloem lectin (PP2) is an RNA-binding, defense-related, chitooligosaccharide-specific, homodimeric lectin of Mr 48 kDa expressed at high concentrations in the sieve elements and companion cells of pumpkin (Cucurbita maxima). In the present study, PP2 was expressed in the methylotrophic yeast Pichia pastoris with the Saccharomyces ?-factor sequence to direct the recombinant protein into the secretory pathway as a prerequisite for unimpaired folding and posttranslational glycosylation of recombinant PP2. Previous computational modeling and ligand docking studies predicted a putative chitooligosaccharide-binding site on the PP2 surface, which was divided into three subsites, with two amino acid residues in each subsite identified as possible candidates for interaction with chitooligosaccharides (CHOs). In this work, mutational analysis and hemagglutination assays were employed to verify the role of the predicted residues in the carbohydrate binding activity of the protein. The results obtained revealed that mutation of Ser-104 to Ala (S104A) at subsite-2 resulted in about 90% loss of agglutination activity of the protein, indicating that Ser-104 is crucial for the binding of CHOs to PP2. Also, L100A (at subsite-1) and K200A (at subsite-3) independently decreased the lectin activity by about 40%, indicating that these two residues also contribute significantly to sugar binding by PP2. Together, these findings confirm that all the three subsites contribute to varying degrees toward PP2-carbohydrate interaction, and confirm the validity of the computational model, as proposed earlier. PMID:24950405

  2. 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 ?-galactoside chains. The quantitative RT-PCR analysis revealed that SAL induced the expression of TNF-? but not of IFN-?, IL-1?, and IL-10. Thus, SAL-induced cytostatic effect on Raji cells might be partially caused by TNF-?-mediated signaling pathway. PMID:24861899

  3. OBSTRUCTIONS ON FUNDAMENTAL GROUPS OF PLANE CURVE COMPLEMENTS

    E-print Network

    Leidy, Constance

    OBSTRUCTIONS ON FUNDAMENTAL GROUPS OF PLANE CURVE COMPLEMENTS CONSTANCE LEIDY AND LAURENTIU MAXIM the very special case of open varieties which are complements to hypersurfaces in Cn (note that complements of complements to hypersurfaces in Cn are precisely the fundamental groups of plane affine curve complements

  4. Characterization of carbohydrate combining sites of Bryohealin, an algal lectin from Bryopsis plumosa

    Microsoft Academic Search

    Min Gui Jung; Key Pyoung Lee; Han-Gu Choi; Sung-Ho Kang; Tatyana A. Klochkova; Jong Won Han; Gwang Hoon Kim

    2010-01-01

    Bryohealin is a lectin involved in the wound-healing process of the marine green alga Bryopsis plumosa. In the previous purification study, it has been shown that lectin was composed of two identical subunits of 27 kDa, cross-linked\\u000a by disulfide bond, and showed binding specificity to N-acetyl-d-glucosamine and N-acetyl-d-galactosamine (GlcNAc and GalNAc, respectively). To determine if the lectin recognize the two different

  5. 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.

  6. Assessment of lectin-binding analysis for in situ detection of glycoconjugates in biofilm systems

    Microsoft Academic Search

    Thomas R. Neu; George D. W. Swerhone; John R. Lawrence

    An assessment of lectin-binding analysis for the characterization of extracellular glycoconjugates as part of the extracellular polymeric substances in environmental microbial communities was performed using fully hydrated river biofilms. The applicability of the method was evaluated for single, dual and triple staining with a panel of fluor-conjugated lectins. It was shown that lectin-binding analysis was able to stain glycoconjugates within

  7. Molecular and Biological Characterization of a Mannan-Binding Lectin from the Holothurian Apostichopus Japonicus

    Microsoft Academic Search

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

    2007-01-01

    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 hemagglu- tination activity was competitively inhibited by extracel- lular low-branched, but not high-branched,

  8. A new Phaseolus vulgaris lectin induces selective toxicity on human liver carcinoma Hep G2 cells

    Microsoft Academic Search

    Evandro Fei Fang; Wen Liang Pan; Jack Ho Wong; Yau Sang Chan; Xiu Juan Ye; Tzi Bun Ng

    We describe here the purification and characterization of a new Phaseolus vulgaris lectin that exhibits selective toxicity to human hepatoma Hep G2 cells and lacks significant toxicity on normal liver WRL\\u000a 68 cells. This polygalacturonic acid–specific lectin (termed BTKL) was purified from seeds of P. vulgaris cv. Blue tiger king by liquid chromatography techniques. The 60-kDa dimeric lectin showed strong

  9. Isolation and characterization of a lectin from the seeds of Dioclea grandiflora (Mart.)

    Microsoft Academic Search

    Renato A. Moreira; Ana C. H. Barros; James C. Stewart; Arpad Pusztai

    1983-01-01

    By a combination of solubility fractionation, affinity and molecular-sieve chromatography, a lectin preparation containing several closely related lectin components of different isoelectric point was isolated from the seeds of Dioclea grandiflora Mart. The lectins showed a carbohydrate specificty for D-mannose (D-glucose)-binding and had a requirement for the presence of Ca2+ and Mn2+. The results of preliminary characterization studies showed that

  10. Structure of a lectin from Canavalia gladiata seeds: new structural insights for old molecules

    Microsoft Academic Search

    Plínio Delatorre; Bruno AM Rocha; Emmanuel P Souza; Taianá M Oliveira; Gustavo A Bezerra; Frederico BMB Moreno; Beatriz T Freitas; Tatiane Santi-Gadelha; Alexandre H Sampaio; Walter F Azevedo; Benildo S Cavada

    2007-01-01

    BACKGROUND: Lectins are mainly described as simple carbohydrate-binding proteins. Previous studies have tried to identify other binding sites, which possible recognize plant hormones, secondary metabolites, and isolated amino acid residues. We report the crystal structure of a lectin isolated from Canavalia gladiata seeds (CGL), describing a new binding pocket, which may be related to pathogen resistance activity in ConA-like lectins;

  11. Differentiated microdomains on the luminal surface of capillary endothelium: distribution of lectin receptors

    Microsoft Academic Search

    MAYA SIMIONESCU; NICOLAE SIMIONESCU; GEORGE E. PALADE

    1982-01-01

    Lectins conjugated with either peroxidase or ferritin were used to detect specific monosaccharide residues on the luminal front of the fenestrated endothelium in the capillaries of murine pancreas and intestinal mucosa. The lectins tested recognize, if accessible, the following residues: ct-N-acetylgalactosaminyl (soybean lectin), fl-D-galactosyl (peanut agglu- tinin (PA) and Ricinus communis agglutinin-120 (RCA)), fl-N-acetylglucosaminyl and sialyl residues (wheat germ agglutinin

  12. Clusters, bundles, arrays and lattices: novel mechanisms for lectin–saccharide-mediated cellular interactions

    Microsoft Academic Search

    C. Fred Brewer; M. Carrie Miceli; Linda G Baum

    2002-01-01

    Multivalent protein–carbohydrate interactions regulate essential cellular events, including cell proliferation, adhesion and death. These multivalent interactions can create homogeneous complexes of lectins, such as the galectins, with their saccharide ligands. Lectin–saccharide complexes can concentrate specific glycoproteins or glycolipids within the lattice, while excluding other cell surface molecules. The formation of lectin–saccharide lattices on the cell surface can thus organize the

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

    PubMed Central

    Schlesinger, L S; Horwitz, M A

    1990-01-01

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

  14. From The Cover: A common haplotype in the complement regulatory gene factor H (HF1\\/CFH) predisposes individuals to age-related macular degeneration

    Microsoft Academic Search

    Gregory S. Hageman; Don H. Anderson; Lincoln V. Johnson; Lisa S. Hancox; Andrew J. Taiber; Lisa I. Hardisty; Jill L. Hageman; Heather A. Stockman; James D. Borchardt; Karen M. Gehrs; Richard J. H. Smith; Giuliana Silvestri; Stephen R. Russell; Caroline C. W. Klaver; Irene Barbazetto; Stanley Chang; Lawrence A. Yannuzzi; Gaetano R. Barile; John C. Merriam; R. Theodore Smith; Adam K. Olsh; Julie Bergeron; Jana Zernant; Joanna E. Merriam; Bert Gold; Michael Dean; Rando Allikmets

    2005-01-01

    Age-related macular degeneration (AMD) is the most frequent cause of irreversible blindness in the elderly in developed countries. Our previous studies implicated activation of complement in the formation of drusen, the hallmark lesion of AMD. Here, we show that factor H (HF1), the major inhibitor of the alternative complement pathway, accumulates within drusen and is synthesized by the retinal pigmented

  15. Studies on a glucose-binding lectin from peripheral blood lymphocytes.

    PubMed

    Kayestha, R; Berry, A; Hajela, K

    1993-11-01

    Lectin-carbohydrate interactions have been found to be important in many of the steps of lymphocyte recirculation and inflammatory responses. A D-glucose-specific lectin was isolated from goat peripheral blood lymphocytes by affinity chromatography on N-acetyl-D-glucosamine agarose and gave a single band corresponding to 112 kDa in SDS-PAGE, irrespective of treatment with 2-mercaptoethanol. The lymphocyte lectin agglutinated rabbit and human ABO erythrocytes, the hemagglutinating activity being Ca2+ dependent. It appears to be a member of type C animal lectins. PMID:8125528

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

    PubMed Central

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

    2015-01-01

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

  17. Characterization of a new lectin involved in the protoplast regeneration of Bryopsis hypnoides

    NASA Astrophysics Data System (ADS)

    Niu, Jianfeng; Wang, Guangce; Lü, Fang; Zhou, Baicheng; Peng, Guang

    2009-09-01

    A group of coenocytic marine algae differs from higher plants, whose totipotency depends on an intact cell (or protoplast). Instead, this alga is able to aggregate its extruded protoplasm in sea water and generate new mature individuals. It is thought that lectins play a key role in the aggregation process. We purified a lectin associated with the aggregation of cell organelles in Bryopsis hypnoides. The lectin was ca. 27 kDa with a pI between pH 5 and pH 6. The absence of carbohydrate suggested that the lectin was not a glycoprotein. The hemagglutinating activity (HA) of the lectin was not dependent on the presence of divalent cations and was inhibited by N-Acetylgalactosamine, N-Acetylglucosamine, and the glycoprotein bovine submaxillary mucin. The lectin preferentially agglutinated Gram-negative bacterium. The HA of this lectin was stable between pH 4 to pH 10. Cell organelles outside the cytoplasm were agglutinated by the addition of lectin solution (0.5 mg ml-1). Our results suggest that the regeneration of B. hypnoides is mediated by this lectin. We also demonstrated that the formation of cell organelle aggregates was inhibited by nigericin in natural seawater (pH 8.0). Given that nigericin dissipates proton gradients across the membrane, we hypothesize that the aggregation of cell organelles was proton-gradient dependent.

  18. Purification and partial characterization of a mitogenic lectin from the latex of Euphorbia marginata.

    PubMed

    Stirpe, F; Licastro, F; Morini, M C; Parente, A; Savino, G; Abbondanza, A; Bolognesi, A; Falasca, A I; Rossi, C A

    1993-08-20

    A lectin was purified from the latex of Euphorbia marginata by affinity chromatography on acid-treated Sepharose 6B and elution with lactose. The lectin is a glycoprotein composed of two identical subunits with M(r) 30,000, approx. The haemagglutinating activity of the lectin is not specific for any human blood group, and is inhibited by galactose and galactose-containing sugars and by gentiobiose. The lectin is strongly mitogenic for human T-lymphocytes and induces the release of interleukin-1 beta and tumor necrosis factor-alpha from cultured mononuclear cells. PMID:8353129

  19. F-type lectin involved in defense against bacterial infection in the pearl oyster (Pinctada martensii).

    PubMed

    Chen, Jinhui; Xiao, Shu; Yu, Ziniu

    2011-02-01

    In invertebrates and vertebrates, carbohydrate-binding proteins (lectins) play an important role in innate immunity against microbial invasion. In the present study, we report the cloning of an F-type lectin (designated as PmF-lectin) from pearl oyster (Pinctada martensii) using a combination of expression sequence tag (EST) analysis and rapid amplification of cDNA ends (RACE) PCR. The full-length cDNA of PmF-lectin contains an open reading frame (ORF) of 579 bp coding for192 amino acids. The deduced polypeptide possesses six conserved residues of the F-lectin family critical for the formation of disulfide bonds (Cys?ł-Cysą?ł, Cys??-Cys?? and Cysą?˛-Cysąą?). Reverse transcription PCR (RT-PCR) and real-time quantitative PCR (qRT-PCR) analyses in adult tissues showed that the PmF-lectin mRNA was abundantly expressed in haemocytes and gill, moderately expressed in the mantle, and rarely expressed in other tissues tested. After challenge with Vibrio alginolyticus, expression of PmF-lectin mRNA in haemocytes was dramatically up-regulated, reaching the highest level (13-fold higher than that of the control group) at 3 h post challenge, and then dropped gradually. These results suggest that PmF-lectin is a member of the F-lectin family and is involved in the innate immune response in pearl oyster. PMID:21195768

  20. 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

  1. Toxicity and Binding Profile of Lectins from the Genus Canavalia on Brine Shrimp

    PubMed Central

    Arruda, Francisco Vassiliepe Sousa; Melo, Arthur Alves; Vasconcelos, Mayron Alves; Carneiro, Romulo Farias; Barroso-Neto, Ito Liberato; Silva, Suzete Roberta; Pereira-Junior, Francisco Nascimento; Nagano, Celso Shiniti; Nascimento, Kyria Santiago; Teixeira, Edson Holanda; Saker-Sampaio, Silvana; Sousa Cavada, Benildo; Sampaio, Alexandre Holanda

    2013-01-01

    Lectins are sugar-binding proteins widely distributed in nature with many biological functions. Although many lectins have a remarkable biotechnological potential, some of them can be cytotoxic. Thus, the aim of this study was to assess the toxicity of five lectins, purified from seeds of different species of Canavalia genus. In order to determine the toxicity, assays with Artemia nauplii were performed. In addition, a fluorescence assay was carried out to evaluate the binding of lectins to Artemia nauplii. In order to verify the relationship between the structure of lectins and their cytotoxic effect, structural analysis was carried out to evaluate the volume of the carbohydrate recognition domain (CRD) of each lectin. The results showed that all lectins exhibited different toxicities and bound to a similar area in the digestive tract of Artemia nauplii. Concerning the structural analysis, differences in spatial arrangement and volume of CRD may explain the variation of the toxicity exhibited by each lectin. To this date, this is the first study that establishes a link between toxicity and structure of CRD from Diocleinae lectins. PMID:24380079

  2. Use of capillary affinity electrophoresis for the determination of lectin-sugar interactions.

    PubMed

    Kuhn, R; Frei, R; Christen, M

    1994-04-01

    Capillary affinity electrophoresis was used to study the interactions of lectins from Tetragonolobus purpuras with L-(-)-fucose 1-phosphate. The electrophoretic mobilities of three lectin peaks were influenced by the complexation with the negatively charged fucose derivative. A model that allows the calculation of the complex formation constant from the change in mobility at different concentrations of fucose 1-phosphate has been derived. Calcium ions added to the buffer solution promoted the complex formation of the three lectins. This technique required only minute amounts of the lectins and enabled the simultaneous study of the complex formation of several proteins. PMID:8053545

  3. Multicopy suppression by asd gene and osmotic stress-dependent complementation by heterologous proA in proA mutants.

    PubMed Central

    Serebrijski, I; Wojcik, F; Reyes, O; Leblon, G

    1995-01-01

    Auxotrophic proA mutants of Escherichia coli were complemented by two different classes of Corynebacterium glutamicum genes. One of these was the asd gene. The E. coli asd gene also complements the same proA alleles. Complementation of proA by the asd+ gene requires a high asd dosage and the proB and the proC gene products. The reciprocal complementation pattern (asd by the proA+ gene) was not observed. This complementation appears to be due to multicopy suppression by a proline biosynthetic gene whose product was expected to play a negligible role in this pathway. The other class of complementing clones carries the C. glutamicum proA gene. Complementation of E. coli proA mutants by the C. glutamicum proA+ gene was optimal at high osmolarity. PMID:8522535

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

    SciTech Connect

    Santi-Gadelha, Tatiane [Departamento de Biologia Molecular, Universidade Federal da Parai'ba, Campus I, Joao Pessoa, Parai'ba (Brazil); Almeida Gadelha, Carlos Alberto de [Departamento de Biologia Molecular, Universidade Federal da Parai'ba, Campus I, Joao Pessoa, Parai'ba (Brazil); Aragao, Karoline Saboia [Departamento de Bioqui'mica, Universidade Federal do Ceara, Campus do Pici, s/n, Bloco 907, 60.455-970, Fortaleza, Ceara (Brazil); Carvalho de Oliveira, Ceci'lia [Departamento de Bioqui'mica, Universidade Federal do Ceara, Campus do Pici, s/n, Bloco 907, 60.455-970, Fortaleza, Ceara (Brazil); Lima Mota, Mario Rogerio [Instituto Superior de Ciencias Biomedicas, Universidade Estadual do Ceara, Av. Paranjana 1700, 60740-000, Fortaleza, Ceara (Brazil); Gomes, Raphaela Cardoso [Instituto Superior de Ciencias Biomedicas, Universidade Estadual do Ceara, Av. Paranjana 1700, 60740-000, Fortaleza, Ceara (Brazil); Freitas Pires, Alana de [Instituto Superior de Ciencias Biomedicas, Universidade Estadual do Ceara, Av. Paranjana 1700, 60740-000, Fortaleza, Ceara (Brazil); Toyama, Marcos Hikari; Oliveira Toyama, Daniela de [Instituto de Biologia, Universidade Estadual de Campinas 13083-970, Campinas, SP (Brazil); Nunes de Alencar, Nylane Maria [Departamento de Fisiologia e Farmacologia, Universidade Federal do Ceara, Campus do Porangabucu, 60.451-970, Fortaleza, Ceara (Brazil); Criddle, David Neil [MRC Secretory Control Research Group, Physiological Laboratory, University of Liverpool, Crown Street, Liverpool L69 3BX (United Kingdom); Assreuy, Ana Maria Sampaio [Instituto Superior de Ciencias Biomedicas, Universidade Estadual do Ceara, Av. Paranjana 1700, 60740-000, Fortaleza, Ceara (Brazil)]. E-mail: assreuy@uece.br; Cavada, Benildo Sousa [Departamento de Bioqui'mica, Universidade Federal do Ceara, Campus do Pici, s/n, Bloco 907, 60.455-970, Fortaleza, Ceara (Brazil)]. 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.

  5. 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

  6. Pea lectin unfolding reveals a unique molten globule fragment chain

    Microsoft Academic Search

    Debasish Sen; Dipak K. Mandal

    2011-01-01

    Pea lectin (PSL) is a dimeric protein in which each subunit comprises two intertwined, post-translationally processed polypeptide chains -a long ?-fragment and a short ?-fragment. Using guanidine hydrochloride-induced denaturation, we have investigated and characterized the species obtained in the unfolding equilibrium of PSL by steady-state and time-resolved fluorescence, phosphorescence, and selective chemical modification. During unfolding, the fragment chains become separated,

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

    Microsoft Academic Search

    Tatiane Santi-Gadelha; Carlos Alberto de Almeida Gadelha; Karoline Sabóia Aragăo; Cec?´lia Carvalho de Oliveira; Mário Rogério Lima Mota; Raphaela Cardoso Gomes; Alana de Freitas Pires; Marcos Hikari Toyama; Daniela de Oliveira Toyama; Nylane Maria Nunes de Alencar; David Neil Criddle; Ana Maria Sampaio. Assreuy; Benildo Sousa. Cavada

    2006-01-01

    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 8.0kDa (SDS–PAGE) and specifically agglutinates rabbit erythrocytes, effect that was independent of the

  8. Effectiveness of garlic lectin on red spider mite of tea

    Microsoft Academic Search

    Anita Roy; Dipankar Chakraborti; Sampa Das

    2008-01-01

    Red spider mite (Oligonychus coffeae) is one of the major pests of tea and damages 5–15% of the total crop every year. Mannose binding 25kDa lectins (ASAI, Allium sativum bulb agglutinin I and ASAII, A. sativum bulb agglutinin II), purified from bulbs of A. sativum (Garlic), was analyzed through SDS-PAGE and studied for its agglutination property using rabbit erythrocytes. Cross

  9. Purification and biological activities of Abelmoschus esculentus seed lectin.

    PubMed

    de Sousa Ferreira Soares, Geórgia; Assreuy, Ana Maria Sampaio; de Almeida Gadelha, Carlos Alberto; de Morais Gomes, Vinicius; Delatorre, Plinio; da Conceiçăo Simőes, Rafael; Cavada, Benildo Sousa; Leite, Joana Filomena; Nagano, Celso Shiniti; Pinto, Nilson Vieira; de Luna Freire Pessoa, Hilzeth; Santi-Gadelha, Tatiane

    2012-12-01

    The Abelmoschus esculentus (Malvaceae) plant originated in Africa and has spread across a number of tropic countries, including northeastern Brazil. The plant has been used to treat various disorders, such as cancer, microbial infections, hypoglycemia, constipation, urine retention and inflammation. The lectin of A. esculentus (AEL) was isolated by precipitation with ammonium sulfate at a saturation level of 30/60 and purified by ion exchange chromatography (Sephacel-DEAE). The electrophoresis (SDS-PAGE) profile of the AEL showed two protein bands of apparent molecular mass of approximately 15.0 and 21.0 kDa. The homogenity of the protein was confirmed by electrospray mass spectrometry (ESI-MS), which revealed the presence of a 10.29-kDa monomer and a 20.58-kDa dimer. The AEL exhibits agglutinating activity against rabbit (74.41 UH/mP) and human type ABO erythrocytes (21.00 UH/mP). This activity does not require the presence of divalent cations and is specifically inhibited by lactose, fructose and mannose. The intravenous treatment with 0.01, 0.1 and 1 mg/kg of AEL inhibited the paw edema elicited by carrageenan by approximately 15, 22 and 44 %, respectively, but not that induced by dextran. In addition, treatment with 0.1, 1 and 10 mg/kg of AEL also inhibited the abdominal writhing induced by acetic acid by approximately 52, 57 and 69 %, respectively. In conclusion, AEL is a new lectin with a molecular mass of 20.0 kDa, which is -composed of a 10.291-Da monomer and a 20.582-kDa dimer, that exhibits anti-inflammatory, antinociceptive and hemagglutinating activities. In addition, the lectin hemagglutinating property is both metallo-independent and associated with the lectin domain. PMID:22965555

  10. Effects of ?-galactosidase digestion on lectin staining in human pancreas

    Microsoft Academic Search

    N. Ito; K. Nishi; M. Nakajima; Y. Okamura; T. Hirota

    1988-01-01

    Effects of a-galactosidase (from green coffee beans) digestion on lectin staining were examined in formalin-fixed, paraffin-embedded human pancreatic tissues from individuals of blood-group B and AB. Digestion with the enzyme resulted in almost complete loss of Griffonia simplicifolia agglutinin I-B4(GSAI-B4) staining in the acinar cells with concomitant appearance of Ulex europaeus agglutinin-I(UEA-I) staining in the corresponding cells. In addition, reactivity

  11. Localization of Prostatic Glycoconjugates by the Lectin-Gold Method

    Microsoft Academic Search

    L. Chan; Y. C. Wong

    1992-01-01

    The glycoconjugates of the lateral prostate were examined ultrastructurally by lectin-gold histochemistry in combination with a low-temperature embedding technique using Lowicryl K4M. The binding patterns of concanavalin A, wheat germ agglutinin, Griffonia simplicifolia, soybean agglutinin, peanut agglutinin, Ricinus communis agglutinin isolectin I, Griffonia simplicifolia isolectin B4, Ulex europaeus isolectin I and Phaseolus vulgaris agglutinin P have been documented in the

  12. Role of lectins in the innate immunity of horseshoe crab

    Microsoft Academic Search

    Shun-ichiro Kawabata; Sadaaki Iwanaga

    1999-01-01

    We have purified five types of lectins, named tachylectins, from circulating hemocytes and hemolymph plasma of the Japanese horseshoe crab, Tachypleus tridentatus. Tachylectin-1 interacts with Gram-negative bacteria probably through 2-keto-3-deoxyoctonate, one of the constituents of lipopolysaccharides (LPS). Tachylectin-1 also binds to polysaccharides such as agarose and dextran with broad specificity. Tachylectin-2 binds to d-GlcNAc or d-GalNAc and recognizes staphylococcal lipoteichoic

  13. Iterative Solution of Dielectric Waveguide Problems via Schur Complement Preconditioners

    E-print Network

    GĂĽrel, Levent

    Iterative Solution of Dielectric Waveguide Problems via Schur Complement Preconditioners Tahir- erties. To overcome this problem, we propose two variants of Schur complement precondi- tioners perforated waveguide problems using these preconditioners. Schur Complement Preconditioning In order

  14. 21 CFR 866.5240 - Complement components immunological test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Complement components immunological test system...Immunological Test Systems § 866.5240 Complement components immunological test system. (a) Identification. A complement components immunological...

  15. COMMON COMPLEMENTS OF TWO SUBSPACES OF A HILBERT SPACE

    E-print Network

    Treil, Sergei

    COMMON COMPLEMENTS OF TWO SUBSPACES OF A HILBERT SPACE condition for two closed subspaces, X and Y, of a Hilbert space H to have a common complement complement are possi- ble. 0. Introduction 0.1. Statement of the problem

  16. 21 CFR 866.5240 - Complement components immunological test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Complement components immunological test system...Immunological Test Systems § 866.5240 Complement components immunological test system. (a) Identification. A complement components immunological...

  17. 21 CFR 866.5240 - Complement components immunological test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Complement components immunological test system...Immunological Test Systems § 866.5240 Complement components immunological test system. (a) Identification. A complement components immunological...

  18. Mss. November 26, 2014 HIGHER CONVEXITY FOR COMPLEMENTS

    E-print Network

    Sottile, Frank

    Mss. November 26, 2014 HIGHER CONVEXITY FOR COMPLEMENTS OF TROPICAL VARIETIES MOUNIR NISSE AND FRANK SOTTILE Abstract. We consider Henriques' homological higher convexity for complements of tropical varieties, establishing it for complements of tropical hypersurfaces and curves, and for nonarchimedean

  19. COMPLEMENTS OF INTERVALS AND PREFRATTINI SUBALGEBRAS OF SOLVABLE LIE ALGEBRAS

    E-print Network

    Haase, Markus

    COMPLEMENTS OF INTERVALS AND PREFRATTINI SUBALGEBRAS OF SOLVABLE LIE ALGEBRAS DAVID A. TOWERS considering complements in subalgebra intervals. Conjugacy of these subalgebras is established for a large Words and Phrases: Lie algebras, complemented, solvable, Frat- tini ideal, prefrattini subalgebra

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

    PubMed Central

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

    2015-01-01

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

  1. Rhizoctonia bataticola lectin (RBL) induces phenotypic and functional characteristics of macrophages in THP-1 cells and human monocytes.

    PubMed

    Pujari, Radha; Kumar, Natesh; Ballal, Suhas; Eligar, Sachin M; Anupama, S; Bhat, Ganapati; Swamy, Bale M; Inamdar, Shashikala R; Shastry, Padma

    2015-02-01

    We have previously reported that a fungal lectin, Rhizoctonia bataticola lectin (RBL), stimulates proliferation and secretion of Th1/Th2 cytokines in human peripheral blood mononuclear cells (PBMC). In the present study, we evaluated the ability of RBL to differentiate human monocytes to macrophages. RBL induced morphological changes indicative of differentiation in primary monocytes and THP-1 cells. Stimulation with RBL resulted in significant up-regulation of differentiation markers - CD54, HLA-DR, CD11b and CD11c and secretion of proinflammatory cytokines - IL-1?, TNF-? and IL-6. Functionally, RBL profoundly increased phagocytic activity in monocytes. In THP-1 cells, RBL-induced phagocytosis was higher compared to the effect induced by combination of phorbol-12-myristate-13-acetate (PMA) and lipopolysaccharide (LPS). RBL induced a significant increase in matrix metalloproteinase-9 (MMP-9) activity in comparison with a combined treatment of PMA+LPS. Mechanistic studies revealed the involvement of the NF-?B pathway in RBL-induced differentiation of monocytes. The data suggest that RBL mimics the combined action of PMA and LPS to induce morphological and functional differentiation in human monocytes and monocytic cell line - THP-1 to macrophages. Human monocytes differentiated to macrophages with RBL have the potential as an in vitro model to study macrophage biology. PMID:25555439

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

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  4. Using lectins to harvest the plasma/serum glycoproteome.

    PubMed

    Fanayan, Susan; Hincapie, Marina; Hancock, William S

    2012-07-01

    Aberrant protein glycosylation has been shown to be associated with disease processes and identification of disease-specific glycoproteins and glycosylation changes may serve as potential diagnostic and therapeutic biomarkers. However despite recent advances in proteomic-based biomarker discovery, this knowledge has not yet translated into an extensive mining of the glycoproteome for potential biomarkers. The major challenge for a comprehensive glycoproteomics analysis arises primarily from the enormous complexity and the large dynamic range in protein constituent in biological samples. Methods that specifically target glycoproteins are therefore necessary to facilitate their selective enrichment prior to their identification by MS-based analysis. The use of lectins, with selective affinities for specific carbohydrate epitopes, to enrich glycoprotein fractions coupled with modern MS, have greatly enhanced the identification of the glycoproteome. On account of their ability to specifically bind cell surface carbohydrates lectins have, during the recent past, found extensive applications in elucidation of the architecture and dynamics of cell surface carbohydrates, glycoconjugate purification, and structural characterization. Combined with complementary depletion and MS technologies, lectin affinity chromatography is becoming the most widely employed method of choice for biomarker discovery in cancer and other diseases. PMID:22740463

  5. Vascular perfusion with fluorescent labeled lectin to study ovarian functions.

    PubMed

    Grazul-Bilska, Anna T; Borowicz, Pawel P; Reynolds, Lawrence P; Redmer, Dale A

    2013-10-01

    The aim of this study was to optimize a method to visualize tissue vascularity by perfusing the local vascular bed with a fluorescently labeled lectin, combined with immunofluorescent labeling of selected vascular/tissue markers. Ovaries with the pedicle were obtained from adult non-pregnant ewes. Immediately after collection, the ovarian artery was perfused with phosphate buffered saline (PBS) to remove blood cells, followed by perfusion with PBS containing fluorescently labeled Griffonia (Bandeiraea) simplicifolia (BS1) lectin. Then, half of ovary was fixed in formalin and another half in Carnoy's fixative. BS1 was detected in blood vessels in ovaries fixed in formalin, but not in Carnoy's fixative. Formalin fixed tissue was used for immunofluorescence staining of two markers of tissue function and/or structure, Ki67 and smooth muscle cell actin (SMCA). Ki67 was detected in granulosa and theca cells, luteal and stromal tissue, and a portion of Ki67 staining was co-localized with blood vessels. SMCA was detected in pericytes within the capillary system, in blood vessels in all ovarian compartments, and in the stroma. Thus, blood vessel perfusion with fluorescently labeled lectin combined with immunohistochemistry, microscopy, and imaging techniques provide an excellent tool to study angiogenesis, vascular architecture, and organ structures and function in physiological and pathological conditions. PMID:23622682

  6. The role of salivary and intestinal complement system inhibitors in the midgut protection of triatomines and mosquitoes.

    PubMed

    Barros, Veruska Cavalcanti; Assumpçăo, Jéssica Góes; Cadete, André Miranda; Santos, Vânia Cristina; Cavalcante, Reginaldo Roris; Araújo, Ricardo Nascimento; Pereira, Marcos Horácio; Gontijo, Nelder Figueiredo

    2009-01-01

    Saliva of haematophagous arthropods contain biomolecules involved directly or indirectly with the haematophagy process, and among them are encountered some complement system inhibitors. The most obvious function for these inhibitors would be the protection of the midgut against injury by the complement. To investigate this hypothesis, Triatoma brasiliensis nymphs were forced to ingest human serum in conditions in which the protection of midgut by the inhibitors is bypassed. In these conditions, the anterior midgut epithelium was injured by the complement, causing cell death. Once some insects such as Aedes aegypti have no salivary inhibitors, we hypothesized the existence of intestinal inhibitors. The inhibitory activity was investigated in the intestine of A. aegypti as well as in the saliva and intestine of other three triatomine species (T. brasiliensis, T. infestans and Rhodnius prolixus) using an immunological method able to determine the level of deposition of some complement factors (C1q, C3b, or C4b) on the surface of complement activator molecules linked to microplates. This methodology permitted to identify which points along the activation phase of the complement cascade were inhibited. As expected, soluble contents of A. aegypti's intestine was capable to inhibit C3b deposition by the classical and alternative pathways. Saliva or soluble intestinal contents, obtained from triatomines were unable to inhibit C1q deposition by the classical pathway. C4b deposition by the classical pathway was inhibited by the intestinal contents from the three triatomines. On the other hand, only T. brasiliensis saliva inhibited C4b deposition. Both, saliva and intestinal contents from all triatomines were able to inhibit C3b deposition in the classical and alternative pathways. None of the material extracted from the intestinal cell membranes from the triatomines inhibited C3b deposition in the classical pathway. The existence of complement inhibitors may have important biological consequences which are discussed in detail. PMID:19557176

  7. Compstatin analog Cp40 inhibits complement dysregulation in vitro in C3 glomerulopathy.

    PubMed

    Zhang, Yuzhou; Shao, Dingwu; Ricklin, Daniel; Hilkin, Brieanna M; Nester, Carla M; Lambris, John D; Smith, Richard J H

    2015-08-01

    C3 glomerulopathy (C3G) defines a group of untreatable ultra-rare renal diseases caused by uncontrolled activation of the alternative complement pathway. Nearly half of patients progress to end stage renal failure within 10 years. Cp40, a second-generation compstatin analog in clinical development, is a 14 amino-acid cyclic peptide that selectively inhibits complement activation in humans and non-human primates by binding to C3 and C3b. We hypothesized that by targeting C3 Cp40 would provide an effective treatment for C3G. By investigating its effects in vitro using multiple assays of complement activity, we show that Cp40 prevents complement-mediated lysis of sheep erythrocytes in sera from C3G patients, prevents complement dysregulation in the presence of patient-derived autoantibodies to the C3 and C5 convertases, and prevents complement dysregulation associated with disease-causing genetic mutations. In aggregate, these data suggest that Cp40 may offer a novel and promising therapeutic option to C3G patients as a disease-specific, targeted therapy. As such, Cp40 could represent a major advance in the treatment of this disease. PMID:25982307

  8. Complement control protein factor H: the good, the bad, and the inadequate.

    PubMed

    Ferreira, Viviana P; Pangburn, Michael K; Cortés, Claudio

    2010-08-01

    The complement system is an essential component of the innate immune system that participates in elimination of pathogens and altered host cells and comprises an essential link between the innate and adaptive immune system. Soluble and membrane-bound complement regulators protect cells and tissues from unintended complement-mediated injury. Complement factor H is a soluble complement regulator essential for controlling the alternative pathway in blood and on cell surfaces. Normal recognition of self-cell markers (i.e. polyanions) and C3b/C3d fragments is necessary for factor H function. Inadequate recognition of host cell surfaces by factor H due to mutations and polymorphisms have been associated with complement-mediated tissue damage and disease. On the other hand, unwanted recognition of pathogens and altered self-cells (i.e. cancer) by factor H is used as an immune evasion strategy. This review will focus on the current knowledge related to these versatile recognition properties of factor H. PMID:20580090

  9. Expression of complement components, receptors and regulators by human dendritic cells.

    PubMed

    Li, Ke; Fazekasova, Henrieta; Wang, Naiyin; Sagoo, Pervinder; Peng, Qi; Khamri, Wafa; Gomes, Chantelle; Sacks, Steven H; Lombardi, Giovanna; Zhou, Wuding

    2011-05-01

    Integration of innate and adaptive arms of the immune response at a cellular and molecular level appears to be fundamental to the development of powerful effector functions in host defence and aberrant immune responses. Here we provide evidence that the functions of human complement activation and antigen presentation converge on dendritic cells (DCs). We show that several subsets of human DCs [i.e., monocyte derived (CD1a(+)CD14(-)), dermal (CD1a(+)DC-SIGN(+)), Langerhans (CD1a(+)Langerin(+)), myeloid (CD1c(+)CD19(-)), plamacytoid (CD45RA(+)CD123(+))] express many of the components of the classical and alternative and terminal pathways of complement. Moreover human DCs have receptors known to detect the biologically active peptides C3a and C5a (C3aR, C5aR) and the covalently bound fragments C3b and metabolites iC3b and C3d which serve in immune adhesion (i.e., CR3, CR4, CRIg). We also show that the human DC surface is characterised by membrane bound regulators of complement activation, which are also known to participate in intracellular signalling (i.e., CD46, CD55, CD59). This work provides an extensive description of complement components relevant to the integrated actions of complement and DC, illuminated by animal studies. It acts as a resource that allows further understanding and exploitation of role of complement in human health and immune mediated diseases. PMID:21397947

  10. Eculizumab treatment during pregnancy does not affect the complement system activity of the newborn.

    PubMed

    Hallstensen, Randi Fykse; Bergseth, Grethe; Foss, Stian; Jćger, Steinar; Gedde-Dahl, Tobias; Holt, Jan; Christiansen, Dorte; Lau, Corinna; Brekke, Ole-Lars; Armstrong, Elina; Stefanovic, Vedran; Andersen, Jan Terje; Sandlie, Inger; Mollnes, Tom Eirik

    2015-04-01

    Eculizumab is a humanized IgG2/4 chimeric anti-complement C5 antibody used to treat patients with paroxysmal nocturnal hemoglobinuria (PNH) or atypical hemolytic uremic syndrome. The aim of this study was to evaluate whether or not the complement activity in newborns from pregnant women who receive eculizumab is impaired. A novel eculizumab-C5 complex (E-C5) specific assay was developed and revealed that two newborns carried only 6-7% of the E-C5 detected in their eculizumab-treated PNH mothers. Serum from the pregnant women completely lacked terminal complement pathway activity, whereas the complement activity in the serum of the newborns was completely normal. Data from the pregnant women and their newborns were compared with that of healthy age-matched female controls and healthy newborns, as well as a non-treated pregnant woman with PNH and her newborn. These all showed normal complement activity without detectable E-C5 complexes. Furthermore, absence of eculizumab or E-C5 in the newborn could not be explained by lack of eculizumab binding to the neonatal Fc receptor (FcRn), as eculizumab bound strongly to the receptor in vitro. In conclusion, despite binding to FcRn neither eculizumab nor E-C5 accumulates in fetal plasma, and eculizumab treatment during pregnancy does not impair the complement function in the newborn. PMID:25468724

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

    PubMed

    Kunchithapautham, Kannan; Atkinson, Carl; Rohrer, Bärbel

    2014-05-23

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

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

    PubMed

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

    2015-06-01

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

  13. Complement in antibody-based tumor therapy.

    PubMed

    Derer, Stefanie; Beurskens, Frank J; Rosner, Thies; Peipp, Matthias; Valerius, Thomas

    2014-01-01

    Monoclonal antibodies constitute a major treatment option for many tumor patients. Due to their specific recognition sites in their constant Fc regions, antibodies are able to trigger antibody-dependent cell-mediated cytotoxicity (ADCC) or complement-dependent cytotoxicity (CDC). While the contribution of ADCC to clinical efficacy has been strengthened by observations that patients with favorable Fc? receptor polymorphisms display better response rates to therapeutic antibodies, the contribution of CDC to their clinical efficacy remains controversial. In the background of high expression of complement-regulatory proteins on tumor cells as well as of the fact that some therapeutic antibodies lack the capacity to trigger efficient CDC, strategies have been implemented to improve either the capacity of antibodies to initiate the complement cascade or to interfere with tumor cells' resistance mechanisms. Although both strategies have demonstrated therapeutic benefit in vitro and in murine models, CDC-enhanced antibodies-to the best of our knowledge-have not been clinically tested, and evidence for the potential of CDC-optimizing approaches has yet to be generated in humans. Hence, the potency of complement activation and its impact on the clinical efficacy of therapeutic antibodies still remains to be elucidated in clinical trials encompassing novel complement-enhancing molecules. PMID:24941073

  14. Complement in Monoclonal Antibody Therapy of Cancer

    PubMed Central

    Rogers, Laura M.; Veeramani, Suresh; Weiner, George J.

    2015-01-01

    Monoclonal antibodies (mAb) have been used as targeted treatments against cancer for more than a decade, with mixed results. Research is needed to understand mAb mechanisms of action with the goal of improving the efficacy of currently used mAbs, and guiding the design of novel mAbs. While some mAb-induced tumor cell killing is a result of direct effects on tumor cell signaling, mAb opsonization of tumor cells also triggers activation of immune responses due to complement activation and engagement of antibody receptors on immune effector cells. In fact, complement has been shown to play an important role in modulating the anti-tumor activity of many mAb through complement-dependent cytotoxicity (CDC), antibody-dependent cytotoxicity (ADCC), and through indirect effects by modulating the tumor microenvironment. Complement activity can have both agonistic and antagonistic effects on these processes, and which mechanisms are most responsible for effective elimination of malignant cells remain unclear. In this review, we discuss the mAbs currently approved for cancer treatment, and examine how complement can impact their efficacy with a focus on how this information might be used to improve the clinical efficacy of mAb treatment. PMID:24906530

  15. Two lectins on the surface of Helix pomatia haemocytes: a Ca 2+ -dependent, GalNac-specific lectin and a Ca 2+ -independent, mannose 6-phosphate-specific lectin which recognises activated homologous opsonins

    Microsoft Academic Search

    Elaine H. Richards; Lothar R. Renwrantz

    1991-01-01

    Haemocytes of the gastropod mollusc, Helix pomatia, possess on their surface a membrane-integrated GalNac-specific lectin which binds to and stimulates phagocytosis of GalNac-bearing target cells (human A erythrocytes) only in the presence of extracellular calcium ions. Target cells without GalNac moieties on their surface (human B and bovine erythrocytes) are not recognised. Helix haemocytes also possess a Ca2+-independent mannose-6-phosphate-specific lectin

  16. Polyamine pathway contributes to the pathogenesis of Parkinson disease

    E-print Network

    Lewandowski, Nicole M.

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

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

    SciTech Connect

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

    1987-08-01

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

  18. Imaging chemokine receptor dimerization with firefly luciferase complementation

    PubMed Central

    Luker, Kathryn E.; Gupta, Mudit; Luker, Gary D.

    2009-01-01

    Seven-transmembrane (G-protein coupled) receptors are key regulators of normal physiology and a large number of diseases, and this family of receptors is the target for almost half of all drugs. Cell culture models suggest that homodimerization and heterodimerization of 7-transmembrane receptors regulate processes including specificity of ligand binding and activation of downstream signaling pathways, making receptor dimerization a critical determinant of receptor biology and a promising new therapeutic target. To monitor receptor dimerization in cell-based assays and living animals, we developed a protein fragment complementation assay based on firefly luciferase to investigate dimerization of chemokine receptors CXCR4 and CXCR7, two 7-transmembrane receptors with central functions in normal development, cancer, and other diseases. Treatment with chemokine ligands and pharmacologic agents produced time- and dose-dependent changes in reporter signal. Chemokines regulated reporter bioluminescence for CXCR4 or CXCR7 homodimers without affecting signals from receptor heterodimers. In a tumor xenograft model of breast cancer, we used bioluminescence imaging to measure changes in receptor homodimerization in response to pharmacologic agents. This technology should be valuable for analyzing function and therapeutic modulation of receptor dimerization in intact cells and living mice.—Luker, K. E., Gupta, M., Luker, G. D. Imaging chemokine receptor dimerization with firefly luciferase complementation. PMID:19001056

  19. Reassessment of immortalization complementation group D.

    PubMed

    Moy, E L; Duncan, E L; Hukku, B; Reddel, R R

    1997-01-01

    Previous somatic cell hybridization studies have assigned many human cell lines to one of four complementation groups (A-D) for immortalization. We report here that the A1698DM cell line, which contains selectable markers and has previously been defined as the immortalization group D representative, was derived from T24 cells rather than A1698. A1698DM did not undergo senescence when fused with cell lines assigned to groups A, B, or C. This raises the possibility that this cell line has undergone further evolution and lost multiple putative senescence genes so that it is now unable to complement any, or most, other cell lines for senescence. Cell lines previously assigned to group D may, therefore, be heterogeneous with respect to the genetic changes that resulted in their immortalization. This has important implications for strategies to clone senescence genes based on complementation groups. PMID:9785092

  20. The extracellular RNA complement of Escherichia coli

    PubMed Central

    Ghosal, Anubrata; Upadhyaya, Bimal Babu; Fritz, Joëlle V; Heintz-Buschart, Anna; Desai, Mahesh S; Yusuf, Dilmurat; Huang, David; Baumuratov, Aidos; Wang, Kai; Galas, David; Wilmes, Paul

    2015-01-01

    The secretion of biomolecules into the extracellular milieu is a common and well-conserved phenomenon in biology. In bacteria, secreted biomolecules are not only involved in intra-species communication but they also play roles in inter-kingdom exchanges and pathogenicity. To date, released products, such as small molecules, DNA, peptides, and proteins, have been well studied in bacteria. However, the bacterial extracellular RNA complement has so far not been comprehensively characterized. Here, we have analyzed, using a combination of physical characterization and high-throughput sequencing, the extracellular RNA complement of both outer membrane vesicle (OMV)-associated and OMV-free RNA of the enteric Gram-negative model bacterium Escherichia coli K-12 substrain MG1655 and have compared it to its intracellular RNA complement. Our results demonstrate that a large part of the extracellular RNA complement is in the size range between 15 and 40 nucleotides and is derived from specific intracellular RNAs. Furthermore, RNA is associated with OMVs and the relative abundances of RNA biotypes in the intracellular, OMV and OMV-free fractions are distinct. Apart from rRNA fragments, a significant portion of the extracellular RNA complement is composed of specific cleavage products of functionally important structural noncoding RNAs, including tRNAs, 4.5S RNA, 6S RNA, and tmRNA. In addition, the extracellular RNA pool includes RNA biotypes from cryptic prophages, intergenic, and coding regions, of which some are so far uncharacterised, for example, transcripts mapping to the fimA-fimL and ves-spy intergenic regions. Our study provides the first detailed characterization of the extracellular RNA complement of the enteric model bacterium E. coli. Analogous to findings in eukaryotes, our results suggest the selective export of specific RNA biotypes by E. coli, which in turn indicates a potential role for extracellular bacterial RNAs in intercellular communication. PMID:25611733

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

    E-print Network

    Hamelryck, Thomas

    arcelin and -amylase inhibitor. In these so-called lectin-like proteins, respectively one and two loops essential for the sugar-binding capabilities of the legume lectins are deleted. The -amylase inhibitor inhibits -amy- lases of mammalian and insect origin but does not inhibit plant -amylases. Arcelin is only

  2. Carbohydrate induced modulation of cell membrane VII. Binding of exogenous lectin increases osmofragility of erythrocytes

    Microsoft Academic Search

    Abhay H. Pande; Sumati; Namita Hajela; Krishnan Hajela

    1998-01-01

    Due to their multivalent binding character, lectins when added exogenously will cross-link membrane surface receptors leading to lateral molecular reorganizations in the plane of the bilayer. This study reports for the first time that agglutination of rabbit erythrocytes by lentil lectin and concanavalin A increases their osmofragility. Increase in osmofragility was detected by measuring the hemolysis of erythrocytes in hypotonic

  3. Lectins Associated With the Feeding Organs of the Oyster Crassostrea virginica Can Mediate Particle

    E-print Network

    Allam, Bassem

    . This study confirms the presence of lectins in mucus that covers the feeding organs of oysters and suggestsLectins Associated With the Feeding Organs of the Oyster Crassostrea virginica Can Mediate Particle Abstract. Despite advances in the study of particle selection in suspension-feeding bivalves

  4. 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

  5. Detection of Sugar Chain Expression in Hydatidiform Mole Using Lectin Histochemistry

    PubMed Central

    Atabaki Pasdar, Fatemeh; Khooei, Alireza; Fazel, Alireza; Mahmoudi, Mahmoud; Tavassoli, Fatemeh

    2013-01-01

    Background Hydatidiform moles carry a significant risk for developing persistent gestational trophoblastic disease. Lectins are useful tools to identify cellular glycosylation pattern and changes in glycosylation that occur during growth, development, differentiation and also, during disease states. Objectives Considering the changes in glycosylation that occur during cell proliferation, differentiation and transformation, the aim of the present study was to evaluate the sugar chain expression in hydatidiform mole by using HRP-conjugated lectins. Materials and Methods Lectin histochemistry with a panel of HRP-conjugated lectins comprising SBA, PNA, VVA, UEA-1, LTA, GS-? (B4) and WGA were performed in 20 molar (partial & complete moles) formalin-fixed, paraffin-embedded tissue samples. Results The partial and complete moles generally showed similar reactivity with all used lectins. None of lectins reacted with villous cytotrophoblasts, whereas 4 of 7 lectins comprising WGA, LTA, UEA-? and PNA (after pretreatment with neuraminidase) showed a moderate to strong reactivity with villous syncytiotrophoblasts in both partial and complete hydatidiform moles. The villous stroma reacted with all used lectins except VVA. Conclusions Our histochemical findings showed a relatively heavy glycosylation of syncytiotrophoblasts of both partial and complete molar tissues, which was prominent in apical portion. This may play a role in their capacity to increase trophoblastic proliferation. PMID:24349722

  6. Functional Mapping of the Lectin Activity Site on the ?-Prism Domain of Vibrio cholerae Cytolysin

    PubMed Central

    Rai, Anand Kumar; Paul, Karan; Chattopadhyay, Kausik

    2013-01-01

    Vibrio cholerae cytolysin (VCC) is a prominent member in the family of ?-barrel pore-forming toxins. It induces lysis of target eukaryotic cells by forming transmembrane oligomeric ?-barrel channels. VCC also exhibits prominent lectin-like activity in interacting with ?1-galactosyl-terminated glycoconjugates. Apart from the cytolysin domain, VCC harbors two lectin-like domains: the ?-Trefoil and the ?-Prism domains; however, precise contribution of these domains in the lectin property of VCC is not known. Also, role(s) of these lectin-like domains in the mode of action of VCC remain obscure. In the present study, we show that the ?-Prism domain of VCC acts as the structural scaffold to determine the lectin activity of the protein toward ?1-galactosyl-terminated glycoconjugates. Toward exploring the physiological implication of the ?-Prism domain, we demonstrate that the presence of the ?-Prism domain-mediated lectin activity is crucial for an efficient interaction of the toxin toward the target cells. Our results also suggest that such lectin activity may act to regulate the oligomerization ability of the membrane-bound VCC toxin. Based on the data presented here, and also consistent with the existing structural information, we propose a novel mechanism of regulation imposed by the ?-Prism domain's lectin activity, implicated in the process of membrane pore formation by VCC. PMID:23209283

  7. Translational control of discoidin lectin expression in drsA suppressor mutants of Dictyostelium discoideum.

    PubMed Central

    Alexander, S; Leone, S; Ostermeyer, E

    1991-01-01

    Genetic analysis in Dictyostelium discoideum has identified regulatory genes which control the developmental expression of the discoidin lectin multigene family. Among these, the drsA mutation is a dominant second-site suppressor of another mutation, disB, which has the discoidinless phenotype. We now demonstrate a novel mechanism by which the drsA allele exerts its suppressive effect on the disB mutation. Interestingly, drsA does not merely bypass the disB mutation and restore the wild-type pattern of lectin expression. Rather, drsA mutant cells have high levels of discoidin lectin synthesis during growth but do not express lectins during aggregation. In contrast, wild-type cells only express lectin protein during the aggregation period of development. Phenocopies of the drsA mutation show a pattern of discoidin expression similar to that seen in the bona fide mutant. These data suggest that there may be a mechanism of negative feedback, resulting from the high levels of discoidin lectin made during growth, which inhibits further discoidin lectin expression during development. Northern (RNA) analysis of developing drsA mutant cells shows that these cells contain high levels of discoidin mRNA, although no discoidin lectin protein is being translated from these messages. Therefore, expression of the discoidin gene family can be controlled at the level of translation as well as transcription. Images PMID:2038325

  8. Purification and Characterization of a Lectin from Phaseolus vulgaris cv. (Anasazi Beans)

    PubMed Central

    Sharma, Arishya; Ng, Tzi Bun; Wong, Jack Ho; Lin, Peng

    2009-01-01

    A lectin has been isolated from seeds of the Phaseolus vulgaris cv. “Anasazi beans” using a procedure that involved affinity chromatography on Affi-gel blue gel, fast protein liquid chromatography (FPLC)-ion exchange chromatography on Mono S, and FPLC-gel filtration on Superdex 200. The lectin was comprised of two 30-kDa subunits with substantial N-terminal sequence similarity to other Phaseolus lectins. The hemagglutinating activity of the lectin was stable within the pH range of 1–14 and the temperature range of 0–80°C. The lectin potently suppressed proliferation of MCF-7 (breast cancer) cells with an IC50 of 1.3 ?M, and inhibited the activity of HIV-1 reverse transcriptase with an IC50 of 7.6 ?M. The lectin evoked a mitogenic response from murine splenocytes as evidenced by an increase in [3H-methyl]-thymidine incorporation. The lectin had no antifungal activity. It did not stimulate nitric oxide production by murine peritoneal macrophages. Chemical modification results indicated that tryptophan was crucial for the hemagglutinating activity of the lectin. PMID:19343172

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

    E-print Network

    Lebendiker, Mario

    -linked oligosaccharides, [GlcNAc(b1,4GlcNAc)1-2 > bGlcNAc] N-acetylgalactosamine/galactose binding lectins Peanut Lectin of N-linked oligosaccharides. It also has affinity to N- acetylneuraminic acid. Application areas

  10. Structural Analysis of the Evolutionary Origins of Influenza Virus Hemagglutinin and Other Viral Lectins

    E-print Network

    Li, Fang

    , crystal structures have been determined for the fol- lowing viral lectins: rotavirus VP4 (2), adenovirus. Among them, rotavirus VP4, adenovirus GD, and coro- navirus spike NTD have been shown to share the same). All of the viral lectins also contain a -sandwich core. Among them, the -sandwich cores of rotavirus

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

    PubMed

    Iatskovski?, 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. Polyamine Metabolism and Uptake during Phaseolus vulgaris Lectin, PHA-Induced Growth of Rat Small Intestine

    Microsoft Academic Search

    S. Bardócz; G. Grant; D. S. Brown; S. W. B. Ewen; I. Nevison; A. Pusztai

    1990-01-01

    Kidney bean lectin, PHA, stimulated the hyperplastic and hypertrophic growth of rat small intestine. This growth was preceded by a rapid accumulation of polyamines in the small intestine. However, since the lectin had little effect on in situ polyamine biosynthesis, most of the polyamines must have been of extracellular origin. To investigate the source of polyamines, both the luminal uptake

  13. [Effects of natural and hybrid lectins on the legume-rhizobium interactions].

    PubMed

    Ba?miev, A Kh; Guba?dullin, I I; Ba?miev, A Kh; Cheremis, A V

    2009-01-01

    The effects of hybrid lectins--full-sized pea Pisum sativum lectin (PSL) with the carbohydrate-binding region of white melilot Melilotus albus lectin or wild licorice Astragalus glycyphyllos lectin substituted for the corresponding PSL region (PSL/MAL and PSL/AGL, correspondingly)--on the legume-rhizobium symbiosis were studied. The treatment of the Rhizobium leguminosarum bv. viciae in the alfalfa (Medicago sativa) rhizosphere with PSL induced formation of uninfected pseudonodules on its roots, whereas the treatment of the bacteria from Astragalus cicer nodules with PSL/AGL rendered these bacteria able to form infective nodules on alfalfa roots. This ability is associated with expanded and unusual carbohydrate-binding properties (combined specificity for Gal and Glc) of this hybrid protein as compared with the natural legume lectins. PMID:19235514

  14. Semantic Bijectivity and the Uniqueness of Constant-Complement Updates

    E-print Network

    Hegner, Stephen J.

    Semantic Bijectivity and the Uniqueness of Constant-Complement Updates in the Relational Context by constant complement is independent of the choice of complement is presented. In contrast to previous update entails. The only requirement is that the view and its complement together possess a property

  15. THE GRAMMATICAL FUNCTIONS OF COMPLEMENT CLAUSES Mary Dalrymple Helge Ldrup

    E-print Network

    Kuhn, Jonas

    THE GRAMMATICAL FUNCTIONS OF COMPLEMENT CLAUSES Mary Dalrymple Helge Lødrup Xerox PARC University, object, complement, or oblique, each with different grammatical properties. Lexical Functional Grammar in the description of the syntax of clausal complementation. A clausal complement can bear one of two grammatical

  16. Complement Constructions in English: Fairly Difficult for EFL Language Learners

    ERIC Educational Resources Information Center

    Fazeli, Fatemeh; Shokrpour, Nasrin

    2012-01-01

    Complement constructions vary significantly in English and Persian. There are more complementation structures in English than in Persian and a complement structure in Persian might have more than one equivalent in English. Producing complement structures (CSs) in English is very difficult for native speakers of Persian, especially in an EFL…

  17. Humoral response to herpes simplex virus is complement-dependent

    E-print Network

    Knipe, David M.

    Humoral response to herpes simplex virus is complement-dependent Xavier J. Da Costa*, Mark A) The complement system represents a cascade of serum proteins, which provide a major effector function in innate immunity. Recent studies have revealed that complement links innate and adaptive immunity via complement

  18. Streptococcus pneumoniae phosphoglycerate kinase is a novel complement inhibitor affecting the membrane attack complex formation.

    PubMed

    Blom, Anna M; Bergmann, Simone; Fulde, Marcus; Riesbeck, Kristian; Agarwal, Vaibhav

    2014-11-21

    The Gram-positive bacterium Streptococcus pneumoniae is a major human pathogen that causes infections ranging from acute otitis media to life-threatening invasive disease. Pneumococci have evolved several strategies to circumvent the host immune response, in particular the complement attack. The pneumococcal glycolytic enzyme phosphoglycerate kinase (PGK) is both secreted and bound to the bacterial surface and simultaneously binds plasminogen and its tissue plasminogen activator tPA. In the present study we demonstrate that PGK has an additional role in modulating the complement attack. PGK interacted with the membrane attack complex (MAC) components C5, C7, and C9, thereby blocking the assembly and membrane insertion of MAC resulting in significant inhibition of the hemolytic activity of human serum. Recombinant PGK interacted in a dose-dependent manner with these terminal pathway proteins, and the interactions were ionic in nature. In addition, PGK inhibited C9 polymerization both in the fluid phase and on the surface of sheep erythrocytes. Interestingly, PGK bound several MAC proteins simultaneously. Although C5 and C7 had partially overlapping binding sites on PGK, C9 did not compete with either one for PGK binding. Moreover, PGK significantly inhibited MAC deposition via both the classical and alternative pathway at the pneumococcal surface. Additionally, upon activation plasmin(ogen) bound to PGK cleaved the central complement protein C3b thereby further modifying the complement attack. In conclusion, our data demonstrate for the first time to our knowledge a novel pneumococcal inhibitor of the terminal complement cascade aiding complement evasion by this important pathogen. PMID:25281746

  19. Vicia villosa B4 lectin is the second anti-Tn lectin shown to react better with blood group N than M antigen

    Microsoft Academic Search

    Maria Duk; Albert M. Wu; Elwira Lisowska

    1994-01-01

    Earlier studies showed thatMoluccella laevis lectin, which has anti-Tn specificity, reacts more strongly with native or desialylated blood group N glycophorin A than with the respective glycophorins of blood group M. We now present results indicating thatVicia villosa B4 anti-Tn lectin, which does not show detectable reaction with untreated glycophorins or erythrocytes, reacts better with desialylated blood group N antigen

  20. Are complement deficiencies really rare? Overview on prevalence, clinical importance and modern diagnostic approach.

    PubMed

    Grumach, Anete Sevciovic; Kirschfink, Michael

    2014-10-01

    Complement deficiencies comprise between 1 and 10% of all primary immunodeficiencies (PIDs) according to national and supranational registries. They are still considered rare and even of less clinical importance. This not only reflects (as in all PIDs) a great lack of awareness among clinicians and general practitioners but is also due to the fact that only few centers worldwide provide a comprehensive laboratory complement analysis. To enable early identification, our aim is to present warning signs for complement deficiencies and recommendations for diagnostic approach. The genetic deficiency of any early component of the classical pathway (C1q, C1r/s, C2, C4) is often associated with autoimmune diseases whereas individuals, deficient of properdin or of the terminal pathway components (C5 to C9), are highly susceptible to meningococcal disease. Deficiency of C1 Inhibitor (hereditary angioedema, HAE) results in episodic angioedema, which in a considerable number of patients with identical symptoms also occurs in factor XII mutations. New clinical entities are now reported indicating disease association with partial complement defects or even certain polymorphisms (factor H, MBL, MASPs). Mutations affecting the regulators factor H, factor I, or CD46 and of C3 and factor B leading to severe dysregulation of the alternative pathway have been associated with renal disorders, such as atypical hemolytic uremic syndrome (aHUS) and - less frequent - with membranoproliferative glomerulonephritis (MPGN). We suggest a multi-stage diagnostic protocol starting based on the recognition of so called warning signs which should aid pediatricians and adult physicians in a timely identification followed by a step-wise complement analysis to characterize the defect at functional, protein and molecular level. PMID:25037634

  1. Selective binding of lectins to normal and neoplastic urothelium in rat and mouse bladder carcinogenesis models.

    PubMed

    Zupan?i?, Daša; Kreft, Mateja Erdani; Romih, Rok

    2014-01-01

    Bladder cancer adjuvant intravesical therapy could be optimized by more selective targeting of neoplastic tissue via specific binding of lectins to plasma membrane carbohydrates. Our aim was to establish rat and mouse models of bladder carcinogenesis to investigate in vivo and ex vivo binding of selected lectins to the luminal surface of normal and neoplastic urothelium. Male rats and mice were treated with 0.05 % N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) in drinking water and used for ex vivo and in vivo lectin binding experiments. Urinary bladder samples were also used for paraffin embedding, scanning electron microscopy and immunofluorescence labelling of uroplakins. During carcinogenesis, the structure of the urinary bladder luminal surface changed from microridges to microvilli and ropy ridges and the expression of urothelial-specific glycoproteins uroplakins was decreased. Ex vivo and in vivo lectin binding experiments gave comparable results. Jacalin (lectin from Artocarpus integrifolia) exhibited the highest selectivity for neoplastic compared to normal urothelium of rats and mice. The binding of lectin from Amaranthus caudatus decreased in rat model and increased in mouse carcinogenesis model, indicating interspecies variations of plasma membrane glycosylation. Lectin from Datura stramonium showed higher affinity for neoplastic urothelium compared to the normal in rat and mouse model. The BBN-induced animal models of bladder carcinogenesis offer a promising approach for lectin binding experiments and further lectin-mediated targeted drug delivery research. Moreover, in vivo lectin binding experiments are comparable to ex vivo experiments, which should be considered when planning and optimizing future research. PMID:23828036

  2. A Novel Antibody against Human Properdin Inhibits the Alternative Complement System and Specifically Detects Properdin from Blood Samples

    PubMed Central

    Pauly, Diana; Nagel, Benedikt M.; Reinders, Jörg; Killian, Tobias; Wulf, Matthias; Ackermann, Susanne; Ehrenstein, Boris; Zipfel, Peter F.; Skerka, Christine; Weber, Bernhard H. F.

    2014-01-01

    The complement system is an essential part of the innate immune system by acting as a first line of defense which is stabilized by properdin, the sole known positive regulator of the alternative complement pathway. Dysregulation of complement can promote a diversity of human inflammatory diseases which are treated by complement inhibitors. Here, we generated a novel blocking monoclonal antibody (mAb) against properdin and devised a new diagnostic assay for this important complement regulator. Mouse mAb 1340 specifically detected native properdin from human samples with high avidity. MAb 1340 inhibited specifically the alternative complement mediated cell lysis within a concentration range of 1–10 µg/mL. Thus, in vitro anti-properdin mAb 1340 was up to fifteen times more efficient in blocking the complement system as compared to anti-C5 or anti-Ba antibodies. Computer-assisted modelling suggested a three-dimensional binding epitope in a properdin-C3(H2O)-clusterin complex to be responsible for the inhibition. Recovery of properdin in a newly established sandwich ELISA using mAb 1340 was determined at 80–125% for blood sample dilutions above 1?50. Reproducibility assays showed a variation below 25% at dilutions less than 1?1,000. Systemic properdin concentrations of healthy controls and patients with age-related macular degeneration or rheumatic diseases were all in the range of 13–30 µg/mL and did not reveal significant differences. These initial results encourage further investigation into the functional role of properdin in the development, progression and treatment of diseases related to the alternative complement pathway. Thus, mAb 1340 represents a potent properdin inhibitor suitable for further research to understand the exact mechanisms how properdin activates the complement C3-convertase and to determine quantitative levels of properdin in biological samples. PMID:24797388

  3. Complementing Software Pipelining with Software Thread Integration

    E-print Network

    Dean, Alexander G.

    Complementing Software Pipelining with Software Thread Integration Won So Alexander G. Dean Center thread integration, software pipelining, coarse- grain parallelism, stream programming, VLIW, DSP, TI C Raleigh, NC 27695-7256 wso@ncsu.edu, alex dean@ncsu.edu Abstract Software pipelining is a critical

  4. Spacelab carrier complement thermal design and performance

    NASA Technical Reports Server (NTRS)

    Bancroft, S.; Key, R.; Kittredge, S.

    1992-01-01

    The present discussion of the Spacelab carrier complement, which encompasses a Module Carrier, a Module-Pallet Carrier, and a Multiplexer/Demultiplexer Pallet, gives attention to both active and passive thermal performance capabilities, and presents ground testing and analytical results obtained to date. An account is given of the prospective use of a Spacelab Multipurpose Experiment Support Structure.

  5. Doubts About Complementation: A Functionalist Analysis

    Microsoft Academic Search

    Shuanfan Huang

    2003-01-01

    The complementation construction in Chinese, like other grammatical constructions, is shown to be highly heterogeneous, and dominated by a number of lexically specific syntactic patterns and schemas. The construction is also shown to be on a grammaticization path, with mental predicates and their subjects having been largely grammaticized as epistemic or deontic formulas or as lexicalized prefabs. In terms of

  6. Information complements, substitutes, and strategic product design

    Microsoft Academic Search

    Geoffrey G. Parker; Marshall W. van Alstyne

    2000-01-01

    Competitive maneuvering in the information economy has raised a pressing question: how can firms raise profits by giving away products for free? This paper provides a possible answer and articulates a strategy space for information product design. Free strategic complements can raise a firm's own profits while free strategic substitutes can lower profits for competitors. We introduce a formal model

  7. [The carbohydrate-binding sequences in lectins of the clovers trifolium repens, T. pratense, and T. trichocephalum].

    PubMed

    Guba?dullin, I I; Ba?miev, Al Kh; Ba?miev, An Kh; Chemeris, A V

    2007-04-01

    The carbohydrate-binding sequences (CBS) in the lectin genes of Trijilium repens, T. pratense, and T. tri-chocephalum were sequenced. The gene regions encoding lectin CBS of T. pratense and T. repens displayed a considerable similarity; however, the CBS of these species differed essentially. Moreover, T. repens formed a compact cluster with Melilotus albus and M. officinalis in the phylogenetic trees constructed according to the nucleotide sequences and the corresponding CBS of legume lectins. T. trichocephalum does not fall into the group of the tribe Trifolieae members according to both the amino acid sequence of lectin carbohydrate-binding region and the nucleotide sequence of lectin gene. PMID:17555123

  8. Characterization of glycoproteins in pancreatic cyst fluid using a high performance multiple lectin affinity chromatography platform

    PubMed Central

    Gbormittah, Francisca Owusu; Haab, Brian B.; Partyka, Katie; Garcia-Ott, Carolina; Hancapie, Marina; Hancock, William S.

    2014-01-01

    Currently, pancreatic cancer is the fourth cause of cancer death. In 2013, it is estimated that approximately 38,460 people will die of pancreatic cancer. Early detection of malignant cyst (pancreatic cancer precursor) is necessary to help prevent late diagnosis of the tumor. In this study, we characterized glycoproteins and non-glycoproteins on pooled mucinous (n=10) and non-mucinous (n=10) pancreatic cyst fluid to identify ‘proteins of interest’ to differentiate between mucinous cyst from non-mucinous cyst and investigate these proteins as potential biomarker targets. An automated multi-lectin affinity chromatography (M-LAC) platform was utilized for glycoprotein enrichment followed by nano-LC-MS/MS analysis. Spectral count quantitation allowed for the identification of proteins with significant differential levels in mucinous cysts from non-mucinous cysts of which one protein (periostin) was confirmed via immunoblotting. To exhaustively evaluate differentially expressed proteins, we used a number of proteomic tools including; gene ontology classification, pathway and network analysis, Novoseek data mining and chromosome gene mapping. Utilization of complementary proteomic tools, revealed that several of the proteins such as mucin 6 (MUC6), bile salt-activated lipase (CEL) and pyruvate kinase lysozyme M1/M2 with significant differential expression have strong association with pancreatic cancer. Further, chromosome gene mapping demonstrated co-expressions and co-localization of some proteins of interest including 14-3-3 protein epsilon (YWHAE), pigment epithelium derived factor (SERPINF1) and oncogene p53. PMID:24303806

  9. Lectin histochemistry on the dorsal epidermis of the Breton dog.

    PubMed

    Desantis, Salvatore; Corriero, Aldo; Acone, Franca; Zubani, Dolores; Cirillo, Fedelia; Palmieri, Giovanni; De Metrio, Gregorio

    2003-01-01

    Expression of sugar residues and the nature of oligosaccharide linkage during keratinocyte maturation in the epidermis of the Breton dog were studied with the use of lectin histochemistry. Thirteen lectins were used. Labelling was not observed with GSA I-B4, GSA II, UEA-I, and LTA. The cytoplasm of keratinocytes reacted with PNA, HPA, Con A, and WGA from the basal layer to the granular layer. PNA and Con A showed highest reactivity in the granular cell layer. The cell surface showed increased reactivity with PNA, HPA, and WGA with maturation of keratinocytes. KOH-neuraminidase treatment (KOH-Neu) increased PNA and RCA120 staining during keratinocyte differentiation thus indicating an increase in oligosaccharides terminating with sialic acid-Galbeta(1,3)GalNAc and sialic acid-Galbeta(1,4)GlcNAc, respectively. Labelling of the glycocalyx of basal and spinous keratinocytes with SNA and MAA revealed terminal Neu5acalpha(2,6)Gal/GalNAc and Neu5acalpha(2,3)Galbeta(1,4)GlcNAc. KOH-Neu-DBA showed oligosaccharides terminating with sialic acid-GalNAcalpha(1,3)GalNAc in the spinous and granular layers. A selective glycocalyx labelling of granular keratinocytes was observed with DBA and SBA. Reactions with MAA, PNA, DBA, RCA120, SBA, HPA, and WGA disappeared after the beta-elimination reaction. Our findings indicate that Breton dog epidermis contains more O-linked than N-linked oligosaccharides and confirm that different subpopulations of keratinocytes can be distinguished by lectin histochemistry. PMID:12666990

  10. Clusterin and Complement Activation in Exfoliation Glaucoma

    PubMed Central

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

    2014-01-01

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

  11. Cystic Fibrosis Transmembrane Conductance Regulator Degradation Depends on the Lectins Htm1p/EDEM and the Cdc48 Protein Complex in Yeast

    PubMed Central

    Gnann, Andreas; Riordan, John R.; Wolf, Dieter H.

    2004-01-01

    Cystic fibrosis is the most widespread hereditary disease among the white population caused by different mutations of the apical membrane ATP-binding cassette transporter cystic fibrosis transmembrane conductance regulator (CFTR). Its most common mutation, ?F508, leads to nearly complete degradation via endoplasmic reticulum-associated degradation (ERAD). Elucidation of the quality control and degradation mechanisms might give rise to new therapeutic approaches to cure this disease. In the yeast Saccharomyces cerevisiae, a variety of components of the protein quality control and degradation system have been identified. Nearly all of these components share homology with mammalian counterparts. We therefore used yeast mutants defective in the ERAD system to identify new components that are involved in human CFTR quality control and degradation. We show the role of the lectin Htm1p in the degradation process of CFTR. Complementation of the HTM1 deficiency in yeast cells by the mammalian orthologue EDEM underlines the necessity of this lectin for CFTR degradation and highlights the similarity of quality control and ERAD in yeast and mammals. Furthermore, degradation of CFTR requires the ubiquitin protein ligases Der3p/Hrd1p and Doa10p as well as the cytosolic trimeric Cdc48p-Ufd1p-Npl4p complex. These proteins also were found to be necessary for ERAD of a mutated yeast “relative” of CFTR, Pdr5*p. PMID:15215312

  12. Potentiation of photodynamic therapy of cancer by complement: the effect of ?-inulin

    PubMed Central

    Korbelik, M; Cooper, P D

    2006-01-01

    Host response elicited by photodynamic therapy (PDT) of cancerous lesions is a critical contributor to the clinical outcome, and complement system has emerged as its important element. Amplification of complement action was shown to improve tumour PDT response. In search of a clinically relevant complement activator for use as a PDT adjuvant, this study focused on ?-inulin and examined its effects on PDT response of mouse tumours. Intralesional ?-inulin (0.1?mg?mouse?1) delivered immediately after PDT rivaled zymosan (potent classical complement activator) in delaying the recurrence of B16BL6 melanomas. This effect of ?-inulin was further enhanced by IFN-? pretreatment. Tumour C3 protein levels, already elevated after individual PDT or ?-inulin treatments, increased much higher after their combination. With fibrosarcomas MCA205 and FsaR, adjuvant ?-inulin proved highly effective in reducing recurrence rates following PDT using four different photosensitisers (BPD, ce6, Photofrin, and mTHPC). At 3 days after PDT plus ?-inulin treatment, over 50% of cells found at the tumour site were CTLs engaged in killing specific targets via perforin–granzyme pathway. This study demonstrates that ?-inulin is highly effective PDT adjuvant and suggests that by amplifying the activation of complement system, this agent potentiates the development of CTL-mediated immunity against PDT-treated tumours. PMID:17146472

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

    PubMed Central

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

    2014-01-01

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

  14. Assessing complement blockade in patients with paroxysmal nocturnal hemoglobinuria receiving eculizumab.

    PubMed

    Peffault de Latour, Régis; Fremeaux-Bacchi, Véronique; Porcher, Raphaël; Xhaard, Aliénor; Rosain, Jérémie; Castaneda, Diana Cadena; Vieira-Martins, Paula; Roncelin, Stéphane; Rodriguez-Otero, Paula; Plessier, Aurélie; Sicre de Fontbrune, Flore; Abbes, Sarah; Robin, Marie; Socié, Gérard

    2015-01-29

    Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by intravascular hemolysis, which is effectively controlled with eculizumab, a humanized monoclonal antibody that binds complement protein 5 (C5). The residual functional activity of C5 can be screened using a 50% hemolytic complement (CH50) assay, which is sensitive to the reduction, absence, and/or inactivity of any components of the classical and terminal complement pathway. Little data exist on complement blockade during treatment. From 2010 to 2012, clinical data, hemolysis biomarkers, complement assessment, and free eculizumab circulating levels were systematically measured immediately before every injection given to 22 patients with hemolytic PNH while receiving eculizumab therapy. During the study, 6 patients received ?1 red blood cell transfusion. Lack of detectable CH50 activity (defined by CH50 ? 10% of normal values) was found in 184 samples (51%) and was significantly associated with lower lactate dehydrogenase levels (P = .002). Low levels of circulating free eculizumab (<50 µg/mL) correlated with detectable CH50 activity (CH50 > 10%; P = .004), elevated bilirubin levels (P < .0001), and the need for transfusions (P = .034). This study suggests that both CH50 activity and circulating free eculizumab levels may help physicians to manage PNH patients receiving eculizumab. PMID:25477495

  15. Isolation and characterization of a complement-activating lipid extracted from human atherosclerotic lesions

    PubMed Central

    1990-01-01

    The major characteristics of human atherosclerotic lesions are similar to those of a chronic inflammatory reaction, namely fibrosis, mesenchymal cell proliferation, the presence of resident macrophages, and cell necrosis. Atherosclerosis exhibits in addition the feature of lipid (mainly cholesterol) accumulation. The results of the present report demonstrate that a specific cholesterol-containing lipid particle present in human atherosclerotic lesions activates the complement system to completion. Thus, lipid could represent a stimulatory factor for the inflammatory reaction, whose underlying mechanistic basis may be, at least in part, complement activation. The complement-activating lipid was purified from saline extracts of aortic atherosclerotic lesions by sucrose density gradient centrifugation followed by molecular sieve chromatography on Sepharose 2B. It contained little protein other than albumin, was 100-500 nm in size, exhibited an unesterified to total cholesterol ratio of 0.58 and an unesterified cholesterol to phospholipid ratio of 1.2. The lipid, termed lesion lipid complement (LCA), activated the alternative pathway of complement in a dose-dependent manner. Lesion-extracted low density lipoprotein (LDL) obtained during the purification procedure failed to activate complement. Specific generation of C3a desArg and C5b-9 by LCA indicated C3/C5 convertase formation with activation proceeding to completion. Biochemical and electron microscopic evaluations revealed that much of the C5b-9 present in atherosclerotic lesions is membraneous, rather than fluid phase SC5b-9. The observations reported herein establish a link between lipid insudation and inflammation in atherosclerotic lesions via the mechanism of complement activation. PMID:2373993

  16. MxA overexpression reveals a common genetic link in four Fanconi anemia complementation groups.

    PubMed Central

    Li, Y; Youssoufian, H

    1997-01-01

    Fanconi anemia (FA) consists of a group of at least five autosomal recessive disorders that share both clinical (e.g., birth defects and hematopoietic failure) and cellular (e.g., sensitivity to cross-linking agents and predisposition to apoptosis) features with each other. However, a common pathogenetic link among these groups has not been established. To identify genetic pathways that are altered in FA and characterize shared molecular defects, we used mRNA differential display to isolate genes that have altered expression patterns in FA cells. Here, we report that the expression of an interferon-inducible gene, MxA, is highly upregulated in cells of FA complementation groups A, B, C, and D, but it is suppressed in FA group C cells complemented with wild-type FAC cDNA as well as in non-FA cells. A posttranscriptional mechanism rather than transcriptional induction appears to account for MxA overexpression. Forced expression of MxA in Hep3B cells enhances their sensitivity to mitomycin C and induces apoptosis, similar to the FA phenotype. Thus, MxA is a downstream target of FAC and is the first genetic marker to be identified among multiple FA complementation groups. These data suggest that FA subtypes converge onto a final common pathway, which is intimately related to the interferon signaling mechanism. Constitutive activity of this pathway may explain a number of the phenotypic features of FA, particularly the pathogenesis of bone marrow failure. PMID:9389754

  17. Plasma-derived mannose-binding lectin shows a direct interaction with C1-inhibitor.

    PubMed

    Keizer, Mischa P; Kamp, Angela M; Brouwer, Nannette; van de Wetering, Marianne D; Wouters, Diana; Kuijpers, Taco W

    2014-04-01

    MBL-deficiency has been associated with an increased frequency and severity of infection, in particular in children and under immunocompromized conditions. In an open uncontrolled safety and pharmacokinetic MBL-substitution study using plasma-derived MBL (pdMBL) in MBL-deficient pediatric oncology patients, we found that despite MBL trough levels above 1.0?g/ml MBL functionality was not efficiently restored upon ex vivo testing. PdMBL showed C4-converting activity by itself, indicating the presence of MASPs. Upon incubation of pdMBL with MBL-deficient sera this C4-converting activity was significantly reduced. Depletion of the MASPs from pdMBL, paradoxically, restored the C4-converting activity. Subsequent depletion or inhibition of C1-inh, the major inhibitor of the lectin pathway, in the recipient serum restored the C4-converting activity as well. Complexes between MBL/MASPs and C1-inh (MMC-complexes) were detected after ex vivo substitution of MBL-deficient serum with pdMBL. These MMC-complexes could also be detected in the sera of the patients included in the MBL-substitution study shortly after pdMBL infusion. Altogether, we concluded that active MBL-MASP complexes in pdMBL directly interact with C1-inh in the recipient, leading to the formation of a multimolecular complex between C1-inh and MBL/MASPs, in contrast to the classical pathway where C1r and C1s are dissociated from C1q by C1-inh. Because of the presence of activated MASPs in the current pdMBL products efficient MBL-mediated host protection cannot be expected because of the neutralizing capacity by C1-inh. PMID:24368318

  18. Molecular Switch Role of Akt in Polygonatum odoratum Lectin-Induced Apoptosis and Autophagy in Human Non-Small Cell Lung Cancer A549 Cells

    PubMed Central

    Shi, Zheng; Wang, Hailian; Zhang, Bin; Zhao, Kailiang; Qi, Wei; Bao, Jinku; Wang, Yi

    2014-01-01

    Polygonatum odoratum lectin (POL), isolated from traditional Chinese medicine herb (Mill.) Druce, has drawn rising attention due to its wide biological activities. In the present study, anti-tumor effects, including apoptosis- and autophagy-inducing properties of POL, were determined by a series of cell biology methods such as MTT, cellular morphology observation, flow cytometry, immunoblotting. Herein, we found that POL could simultaneously induce apoptosis and autophagy in human non-small cell lung cancer A549 cells. POL initiated apoptosis through inhibiting Akt-NF-?B pathway, while POL triggered autophagy via suppressing Akt-mTOR pathway, suggesting the molecular switch role of Akt in regulating between POL-induced apoptosis and autophagy. Moreover, ROS was involved in POL-induced inhibition of Akt expression, and might therefore mediate both apoptosis and autophagy in A549 cells. In addition, POL displayed no significant cytotoxicity toward normal human embryonic lung fibroblast HELF cells. Due to the anti-tumor activities, POL might become a potent anti-cancer drug in future therapy, which might pave the way for exploring GNA-related lectins into effective drugs in cancer treatment. PMID:24992302

  19. Purification and partial characterization of a fructose-binding lectin from the leaves of Euphorbia helioscopia.

    PubMed

    Rafiq, Shaista; Qadir, Sakeena; Wani, Ishfak Hussain; Ganie, Showkat Ahmad; Masood, Akbar; Hamid, Rabia

    2014-11-01

    A lectin was purified from leaves of Euphorbia helioscopia, by a combination of ion-exchange and gel filtration chromatography. On ion exchange using a DEAE- cellulose column in 0.2 M phosphate buffer, pH 7.2, the bound protein was eluted with a linear sodium chloride gradient of 0.1 M to 0.5 M. Further purification of the lectin was achieved by gel filtration on Sephadex G-100. Euphorbia helioscopia lectin (EHL) agglutinates only chick erythrocytes, showing no agglutination of all human blood group erythrocytes. The EHL induced hemagglutination is inhibited by fructose. The purified protein showed one band, both in non-denaturing PAGE and SDS-PAGE establishing the charge and size homogeneities of the lectin preparation. The molecular mass of the lectin as indicated by SDS-PAGE was approximately 31 kDa and that estimated from G-100 gel filtration chromatography was about 65 kDa establishing that the lectin is a homodimer. The lectin was stable within a temperature range of 0°C-40°C and exhibited a narrow range of pH stability, being optimally active at around pH 7. EHL also possesses antimicrobial activity and is an inhibitor of bacterial growth particularly Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli. PMID:25362590

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

    PubMed Central

    Das, Sudipta Sekhar

    2015-01-01

    Polyagglutination is a condition in which red cells are agglutinated by ABO-compatible adult human sera, but not by cord blood sera and may be acquired or inherited. Lectins are invaluable reagents in the investigation of red cells polyagglutination. We prepared in-house lectin panel and confirmed Tn polyagglutination in a pregnant lady. The lady was anemic and refused blood transfusion elsewhere due to serological discrepancy. We found ABO discrepancy and an incompatible minor cross-match in the initial investigation and suspected polyagglutination. Confirmation of polyagglutination was done using adult and cord sera. We then used the in-house lectin panels to detect the type of polyagglutination. The agglutination pattern with the various lectins was suggestive of Tn polyagglutination, which was further supported by the enzyme study. Most blood banks in India lack commercial lectin panels because of cost and procurement difficulty. Lectins play an important role in the diagnosis and differentiation of polyagglutination and immunohematological management of patient. The important and basic lectins can be prepared in-house using specific raw seeds following standardized protocol. PMID:25722587

  1. Tissue and subcellular distribution of the lectin from Datura stramonium (thorn apple).

    PubMed Central

    Kilpatrick, D C; Yeoman, M M; Gould, A R

    1979-01-01

    Plants of Datura stramonium (thorn-apple) were dissected into their component tissues and examined for the presence of the Datura lectin. This lectin was easily detected in seeds and in various parts of the flowers of adult plants. Traces were also found in green (emerged) cotyledons and roots of seedlings. The specific lectin activity in seeds contained within the fruits increased as the seeds matured. Mature seeds were homogenized in sucrose and separated by differential centrifugation into four fractions, three of which were clearly of distinct composition. Most of the lectin activity sedimented with the low-speed (cell-wall/protein-body) pellet, but a similar specific activity was recovered from the other fractions. However, if EDTA was included in the homogenization medium, three or four times more lectin activity was recovered in the soluble fraction. Immunofluorescent staining of formaldehyde-fixed sections showed that the lectin was localized in the cytoplasm, with little associated with cell walls. The possible relevance of these results to the function of the lectin in plant cells is discussed. Images PLATE 1 PLATE 2 PMID:393254

  2. Structure of a lectin from Canavalia gladiata seeds: new structural insights for old molecules

    PubMed Central

    Delatorre, Plínio; Rocha, Bruno AM; Souza, Emmanuel P; Oliveira, Taianá M; Bezerra, Gustavo A; Moreno, Frederico BMB; Freitas, Beatriz T; Santi-Gadelha, Tatiane; Sampaio, Alexandre H; Azevedo, Walter F; Cavada, Benildo S

    2007-01-01

    Background Lectins are mainly described as simple carbohydrate-binding proteins. Previous studies have tried to identify other binding sites, which possible recognize plant hormones, secondary metabolites, and isolated amino acid residues. We report the crystal structure of a lectin isolated from Canavalia gladiata seeds (CGL), describing a new binding pocket, which may be related to pathogen resistance activity in ConA-like lectins; a site where a non-protein amino-acid, ?-aminobutyric acid (Abu), is bound. Results The overall structure of native CGL and complexed with ?-methyl-mannoside and Abu have been refined at 2.3 Ĺ and 2.31 Ĺ resolution, respectively. Analysis of the electron density maps of the CGL structure shows clearly the presence of Abu, which was confirmed by mass spectrometry. Conclusion The presence of Abu in a plant lectin structure strongly indicates the ability of lectins on carrying secondary metabolites. Comparison of the amino acids composing the site with other legume lectins revealed that this site is conserved, providing an evidence of the biological relevance of this site. This new action of lectins strengthens their role in defense mechanisms in plants. PMID:17683532

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

    PubMed Central

    2009-01-01

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

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

    PubMed

    Roberson, M M; Barondes, S H

    1982-07-10

    Soluble extracts of Xenopus laevis blastula stage embryos, oocytes, and adult liver contain lectin activities detected by agglutination of trypsinized, glutaraldehyde-fixed rabbit erythrocytes. Lectin from the embryos and oocytes was purified by affinity chromatography on a column derivatized with melibiose. Trace contaminants were removed either by preparative isoelectric focusing or by gel filtration. Based on its behavior on Sepharose 6B the purified oocyte lectin has an apparent molecular weight of approximately 480,000. On sodium dodecyl sulfate polyacrylamide gel electrophoresis under reducing conditions there were two major bands with molecular weight ranges of about 43,000 and 45,000, with diffuse trails. Since the purified lectin contains about 20% saccharides by weight and since both bands are glycosylated, diffuseness might be due to variable glycosylation. Heterogeneity was indicated by isoelectric focusing in polyacrylamide gels, which showed four protein bands with isoelectric points ranging from 4.4 to 4.9. Lectins from both embryos and oocytes comprised about 1 to 2% of the total soluble protein and could not be distinguished by sodium dodecyl sulfate polyacrylamide gel electrophoresis. However, the specific hemagglutination activity of the purified oocyte lectin was, on the average, 7-fold higher. Levels in crude extracts of liver were 3 orders of magnitude lower than those from oocytes. The hemagglutination activities of the lectins from embryos, oocytes, and adult liver required Ca2+ and were blocked by similar concentrations of both alpha- and beta-galactosides. PMID:7085636

  5. Quantitation of two endogenous lactose-inhibitable lectins in embryonic and adult chicken tissues

    SciTech Connect

    Beyer, E.C. (University of California San Diego, La Jolla); Barondes, S.H.

    1982-01-01

    Two lactose-binding lectins from chicken tissues, chicken-lactose-lectin-I (CLL-I) and chicken-lactose-lectin-II (CLL-II) were quantified with a radioimmunoassay in extracts of a number of developing and adult chicken tissues. Both lectins could be measured in the same extract without separation, because they showed no significant immunological cross- reactivity. Many embryonic and adult tissues, including brain, heart, intestine, kidney, liver, lung, muscle, pancreas, and spleen, contained one or both lectins, although their concentrations differed markedly. For example, embryonic muscle, the richest source of CLL-I contained only traces of CLL-II whereas embryonic kidney, a very rich source of CLL-II contained substantial CLL-I. In both muscle and kidney, lectin levels in adulthood were much lower than in the embryonic state. In contrast, CLL-I in liver and CLL-II in intestine were 10-fold to 30-fold more concentrated in the adult than in the 15-d embryo. CLL-I and CLL-II from several tissues were purified by affinity chromatography and their identity in the various tissues was confirmed by polyacrylamide gel electrophoresis, isoelectric focusing, and peptide mapping. The results suggest that these lectins might have different functions in the many developing and adult tissues in which they are found.

  6. Mesenchymal Stromal Cells Engage Complement and Complement Receptor Bearing Innate Effector Cells to Modulate Immune Responses

    Microsoft Academic Search

    Guido Moll; Regina Jitschin; Lena von Bahr; Ida Rasmusson-Duprez; Berit Sundberg; Lena Lönnies; Graciela Elgue; Kristina Nilsson-Ekdahl; Dimitrios Mougiakakos; John D. Lambris; Olle Ringdén; Katarina Le Blanc; Bo Nilsson; Anna Carla Goldberg

    2011-01-01

    Infusion of human third-party mesenchymal stromal cells (MSCs) appears to be a promising therapy for acute graft-versus-host disease (aGvHD). To date, little is known about how MSCs interact with the body's innate immune system after clinical infusion. This study shows, that exposure of MSCs to blood type ABO-matched human blood activates the complement system, which triggers complement-mediated lymphoid and myeloid

  7. Pea lectin unfolding reveals a unique molten globule fragment chain.

    PubMed

    Sen, Debasish; Mandal, Dipak K

    2011-03-01

    Pea lectin (PSL) is a dimeric protein in which each subunit comprises two intertwined, post-translationally processed polypeptide chains--a long ?-fragment and a short ?-fragment. Using guanidine hydrochloride-induced denaturation, we have investigated and characterized the species obtained in the unfolding equilibrium of PSL by steady-state and time-resolved fluorescence, phosphorescence, and selective chemical modification. During unfolding, the fragment chains become separated, and the unfolding pattern reveals a ?-fragment as intermediate that has the molten globule characteristics. As examined by 8-anilino-1-naphthalenesulfonate (ANS) binding, the fragment intermediate shows ~20 fold increase in ANS fluorescence, and a large increase in ANS lifetime (12.8 ns). The tryptophan environment of the molten globule ?-fragment has been probed by selective modification with N-bromosuccinimide (NBS), which shows that two tryptophans, possibly Trp 53 and Trp 152 are oxidized while the other Trp 128 remains resistant to oxidation. The different types of tryptophan environment for the intermediate are supported by phosphorescence studies at 77 K, which gives a (0,0) band at 410 nm. These results seem to indicate that the larger fragment chain of PSL can independently behave as a monomeric or single domain protein that undergoes unfolding through intermediate state(s), and may provide important insight into the folding problem of oligomeric proteins in general and lectins in particular. PMID:21078359

  8. Spodoptera littoralis-induced lectin expression in tobacco.

    PubMed

    Vandenborre, Gianni; Miersch, Otto; Hause, Bettina; Smagghe, Guy; Wasternack, Claus; Van Damme, Els J M

    2009-06-01

    The induced defense response in plants towards herbivores is mainly regulated by jasmonates and leads to the accumulation of so-called jasmonate-induced proteins. Recently, a jasmonate (JA) inducible lectin called Nicotiana tabacum agglutinin or NICTABA was discovered in tobacco (N. tabacum cv Samsun) leaves. Tobacco plants also accumulate the lectin after insect attack by caterpillars. To study the functional role of NICTABA, the accumulation of the JA precursor 12-oxophytodienoic acid (OPDA), JA as well as different JA metabolites were analyzed in tobacco leaves after herbivory by larvae of the cotton leafworm (Spodoptera littoralis) and correlated with NICTABA accumulation. It was shown that OPDA, JA as well as its methyl ester can trigger NICTABA accumulation. However, hydroxylation of JA and its subsequent sulfation and glucosylation results in inactive compounds that have lost the capacity to induce NICTABA gene expression. The expression profile of NICTABA after caterpillar feeding was recorded in local as well as in systemic leaves, and compared to the expression of several genes encoding defense proteins, and genes encoding a tobacco systemin and the allene oxide cyclase, an enzyme in JA biosynthesis. Furthermore, the accumulation of NICTABA was quantified after S. littoralis herbivory and immunofluorescence microscopy was used to study the localization of NICTABA in the tobacco leaf. PMID:19416954

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

    PubMed Central

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

    2015-01-01

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

  10. Isolation and characterization of an N-acetylgalactosamine specific lectin from Salvia sclarea seeds.

    PubMed

    Piller, V; Piller, F; Cartron, J P

    1986-10-25

    Crude extracts from Salvia sclarea seeds were known to contain a lectin which specifically agglutinates Tn erythrocytes (Bird, G. W. G., and Wingham, G. (1974) Vox Sang. 26, 163-166). We have purified the lectin to homogeneity by ion-exchange chromatography and affinity chromatography. The agglutinin was found to be a glycoprotein of Mr = 50,000, composed of two identical subunits of Mr = 35,000 linked together by disulfide bonds. The purified lectin agglutinates specifically Tn erythrocytes and, at higher concentrations, also Cad erythrocytes. Native A, B, or O red blood cells are not agglutinated by the lectin and, even after treatment with sialidase or papain, these cells are not recognized. Tn red cells present 1.45 X 10(6) accessible sites to the lectin which binds to these erythrocytes with an association constant of 1.8 X 10(6) M-1. On Cad red cells, 1.73 X 10(6) sites are accessible to the lectin which binds with an association constant of 1.0 X 10(6) M-1. The carbohydrate specificity of the S. sclarea lectin has been determined in detail, using well defined monosaccharide, oligosaccharide, and glycopeptide structures. The lectin was found to be specific for terminal N-acetylgalactosamine (GalNAc) residues. It binds preferentially alpha GalNAc determinants either linked to Ser or Thr (as in Tn structures) or linked in 1-3 to a beta GalNAc or to an unsubstituted beta Gal. Although more weakly, the lectin binds beta GalNAc residues linked in 1-4 to a beta Gal (as in Cad structures). It does not recognize beta GalNAc determinants linked in 1-3 to a Gal (as in globoside) or the alpha GalNAc residues of blood group A structures. PMID:3771523

  11. Inadequate Binding of Immune Regulator Factor H Is Associated with Sensitivity of Borrelia lusitaniae to Human Complement?

    PubMed Central

    Dieterich, Roswitha; Hammerschmidt, Claudia; Richter, Dania; Skerka, Christine; Wallich, Reinhard; Matuschka, Franz-Rainer; Zipfel, Peter F.; Kraiczy, Peter

    2010-01-01

    Spirochetes belonging to the Borrelia burgdorferi sensu lato complex differ in resistance to complement-mediated killing by human serum. Here, we characterize complement sensitivity of a panel of B. lusitaniae isolates derived from ticks collected in Germany and Portugal as well as one patient-derived isolate, PoHL. All isolates are highly susceptible to complement-mediated lysis in human serum and activate complement predominantly by the alternative pathway, leading to an increased deposition of complement components C3, C6, and the terminal complement complex. Interestingly, serum-sensitive B. lusitaniae isolates were able to bind immune regulator factor H (CFH), and some strains also bound CFH-related protein 1 (CFHR1) and CFHR2. Moreover, CFH bound to the surface of B. lusitaniae was inefficient in mediating C3b conversion. Furthermore, the identification and characterization of a potential CFH-binding protein, OspE, revealed that this molecule possesses a significantly reduced binding capacity for CFH compared to that of CFH-binding OspE paralogs expressed by various serum-resistant Borrelia species. This finding suggests that a reduced binding capability of CFH is associated with an increased serum sensitivity of B. lusitaniae to human complement. PMID:20823202

  12. Reference instrument complement for IPNS Upgrade

    SciTech Connect

    Crawford, R.K.

    1993-07-01

    A feasibility study for a new 1 MW pulsed neutron source has recently been completed at Argonne. As part of this feasibility study, an instrument package to instrument 24 of the 36 beam ports has been considered. This complement of instruments is outlined, and details of some of the instruments are discussed. Developments required before some of these instruments can be built are also indicated.

  13. Reassessment of immortalization complementation group D

    Microsoft Academic Search

    Elsa L. Moy; Emma L. Duncan; Bharati Hukku; Roger R. Reddel

    1997-01-01

    Previous somatic cell hybridization studies have assigned many human cell lines to one of four complementation groups (A-D) for immortalization. We report here that the A 1698DM cell line, which contains selectable markers and has previously been defined as the immortalization group D representative, was derived from T24 cells rather than A1698. A1698DM did not undergo senescence when fused with

  14. Recognition of a CD4+ mouse medullary thymocyte subpopulation by Amaranthus leucocarpus lectin.

    PubMed Central

    Lascurain, R; Chávez, R; Gorocica, P; Pérez, A; Montańo, L F; Zenteno, E

    1994-01-01

    We have used the Gal beta(1-->3)GalNAc-specific Amaranthus leucocarpus lectin to isolate a thymus cell subpopulation which is different from that sorted with Arachis hypogaea lectin. The cells recognized by A. leucocarpus lectin were predominantly CD4+, whereas a minor proportion of CD8+ cells (approximately 11%) were also identified. The A. leucocarpus-positive cells were located in the thymus medulla and the cortico-medullary junction. The cortex was negative for A. leucocarpus cells. Images Figure 1 Figure 2 Figure 3 PMID:7835965

  15. Carbohydrate induced modulation of cell membrane VII. Binding of exogenous lectin increases osmofragility of erythrocytes.

    PubMed

    Pande, A H; Sumati, N; Hajela, N; Hajela, K

    1998-05-01

    Due to their multivalent binding character, lectins when added exogenously will cross-link membrane surface receptors leading to lateral molecular reorganizations in the plane of the bilayer. This study reports for the first time that agglutination of rabbit erythrocytes by lentil lectin and concanavalin A increases their osmofragility. Increase in osmofragility was detected by measuring the hemolysis of erythrocytes in hypotonic as well as in isotonic solutions. It was also found that agglutination per se does not increase osmofragility but the binding of legume lectin is essential since human Rh+ cells agglutinated by a monoclonal antibody do not exhibit hemolysis. PMID:9613592

  16. Studies on the chemical modification of potato (Solanum tuberosum) lectin and its effect on haemagglutinating activity

    PubMed Central

    Ashford, David; Menon, Rajeev; Allen, Anthony K.; Neuberger, Albert

    1981-01-01

    1. Modification of potato (Solanum tuberosum) lectin with acetic anhydride blocked 5.1 amino and 2.7 tyrosyl groups per molecule of lectin and decreased the haemagglutinating activity of the lectin. De-O-acetylation regenerated 2.0 of the tyrosyl groups and resulted in a recovery of activity. 2. Modification with citraconic anhydride or cyclohexane-1,2-dione did not greatly affect activity, although modification of amino and arginyl groups could be demonstrated. 3. Treatment with tetranitromethane nitrated 3.7 tyrosine residues per molecule of lectin with concomitant loss of activity. The presence of 0.1m-NN?N?-triacetylchitotriose (a potent inhibitor of the lectin) in the reaction medium protected all the tyrosyl residues from nitration and the lectin was fully active. 4. Modification of tryptophyl groups with 2-hydroxy-5-nitrobenzyl bromide and 2,3-dioxoindoline-5-sulphonic acid modified 0.9 and 2.6 residues per molecule of lectin respectively with a loss of activity in each case. Reaction of potato lectin with 2,3-dioxoindoline-5-sulphonic acid in the presence of inhibitor protected 2.4 residues of tryptophan from the reagent. Loss of haemagglutination activity was prevented under these conditions. 5. Reaction of carboxy groups, activated with carbodi-imide, with ?-aminobutyric acid methyl ester led to the incorporation of 5.3 residues of the ester per molecule of lectin. Presence of inhibitor in this case, although protecting activity, did not prevent modification of carboxy groups; in fact an increase in the number of modified residues was seen. This effect could be imitated by performing the reaction in 8m-urea. In both cases the number of carboxy groups modified was close to the total number of free carboxy groups as determined by the method of Hoare & Koshland [(1967) J. Biol. Chem. 242, 2447–2453]. Guanidination of lysine residues after carboxy-group modification gave less homoarginine than did the unmodified lectin under the same conditions, suggesting the formation of intramolecular cross-links during carbodi-imide activation. 6. It is suggested from the results presented that amino, arginyl, methionyl, histidyl and carboxyl groups are not involved in the activity of the lectin and that tyrosyl and tryptophyl groups are very closely involved. These findings are similar to those reported for other proteins that bind N-acetylglucosamine oligomers and also fit the general trend in other lectins. PMID:7340810

  17. Isolation of lectins by affinity chromatography with porcine plasma proteins immobilized on agarose.

    PubMed

    Kajiya, Akane; Koyama, Yu; Mita, Takashi; Mega, Tomohiro; Hase, Sumihiro; Kawakami, Toshioki; Honda, Eiko; Munakata, Hiroshi; Isemura, Mamoru

    2003-09-01

    To develop a convenient method to isolate lectins, we prepared an affinity gel by coupling plasma proteins with agarose beads under conditions where the pH did not exceed 7.5. The validity of the use of this affinity gel in combination with elution using a hapten saccharide was confirmed by isolation of concanavalin A from Jack bean meal. Successful application of the method was demonstrated by isolation of two novel vegetable lectins from udo (Aralia cordate) and wasabi (Wasabia japonica). The method would be useful to isolate new lectins from various sources including plant and animal tissues. PMID:14520004

  18. Biomimics of fungal cell-cell recognition by use of lectin-coated nylon fibers.

    PubMed Central

    Inbar, J; Chet, I

    1992-01-01

    When the mycoparasitic, biocontrol fungus Trichoderma harzianum was allowed to grow on nylon fibers treated with concanavalin A or Sclerotium rolfsii lectin, it coiled around the nylon fibers and produced hooks in a pattern similar to that observed with the real host hyphae. The incidence of interaction between T. harzianum and S. rolfsii lectin-treated fibers was significantly higher than that of the controls (untreated or blocked activated fibers). These findings provide direct evidence for the role of lectins in mycoparasitism. Images PMID:1732197

  19. Shiga toxin-induced complement-mediated hemolysis and release of complement-coated red blood cell-derived microvesicles in hemolytic uremic syndrome.

    PubMed

    Arvidsson, Ida; Stĺhl, Anne-Lie; Hedström, Minola Manea; Kristoffersson, Ann-Charlotte; Rylander, Christian; Westman, Julia S; Storry, Jill R; Olsson, Martin L; Karpman, Diana

    2015-03-01

    Shiga toxin (Stx)-producing Escherichia coli (STEC) cause hemolytic uremic syndrome (HUS). This study investigated whether Stx2 induces hemolysis and whether complement is involved in the hemolytic process. RBCs and/or RBC-derived microvesicles from patients with STEC-HUS (n = 25) were investigated for the presence of C3 and C9 by flow cytometry. Patients exhibited increased C3 deposition on RBCs compared with controls (p < 0.001), as well as high levels of C3- and C9-bearing RBC-derived microvesicles during the acute phase, which decreased after recovery. Stx2 bound to P1 (k) and P2 (k) phenotype RBCs, expressing high levels of the P(k) Ag (globotriaosylceramide), the known Stx receptor. Stx2 induced the release of hemoglobin and lactate dehydrogenase in whole blood, indicating hemolysis. Stx2-induced hemolysis was not demonstrated in the absence of plasma and was inhibited by heat inactivation, as well as by the terminal complement pathway Ab eculizumab, the purinergic P2 receptor antagonist suramin, and EDTA. In the presence of whole blood or plasma/serum, Stx2 induced the release of RBC-derived microvesicles coated with C5b-9, a process that was inhibited by EDTA, in the absence of factor B, and by purinergic P2 receptor antagonists. Thus, complement-coated RBC-derived microvesicles are elevated in HUS patients and induced in vitro by incubation of RBCs with Stx2, which also induced hemolysis. The role of complement in Stx2-mediated hemolysis was demonstrated by its occurrence only in the presence of plasma and its abrogation by heat inactivation, EDTA, and eculizumab. Complement activation on RBCs could play a role in the hemolytic process occurring during STEC-HUS. PMID:25637016

  20. Cell- and region-specific expression of sugar chains in the mouse epididymal epithelium using lectin histochemistry combined with immunohistochemistry.

    PubMed

    Tajiri, Shota; Fukui, Tatsuya; Sawaguchi, Akira; Yoshinaga, Kazuya

    2012-02-01

    To understand the cytochemical properties of epididymal epithelial cells, the characteristics of glycoconjugates in the mouse epididymis were examined using the technique of lectin histochemistry combined with immunohistochemistry. Characteristic staining patterns depending on the type of lectins were observed in the epididymal epithelium. Principal cells expressed N-acetyl-D-galactosamine (GalNAc), N-acetyl-D-glucosamine (GlcNAc), and Fucose in the proximal region of the epididymis and Mannose, Glucose, and Galactose in the distal region of the epididymis. Basal cells expressed Mannose, Glucose, Galactose, and GlcNAc in the proximal region and Galactose in the distal region. On the other hand, clear cells expressed various sugar residues and differences among regions were not observed. Interestingly, principal cells, clear cells, and basal cells specifically reacted with Ulex Europaeus-Agglutinin I (UEA-I lectin), Maackia Amurensis-Lectin I (MAL-I lectin), and Griffonia simplicifolia Lectin I-B4 (GS-I B lectin), respectively. These findings indicate that the selectivity in lectin reactivity for distinct cell types and segment-dependent staining in the epididymis may be related to cellular and regional differences in function. Furthermore, because some lectins stain particular cells or cellular compartments selectively, these lectins could be useful markers for histopathological evaluation of diseases or diagnosis of male infertility. PMID:22645905