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Query: UMLS:C0001511 (Adhesion)
 5,955 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The adhesion of the S fimbriae of meningitis-associated Escherichia coli O18ac:K1:H7 to the cellular and the plasma forms of human fibronectin was studied. E. coli HB101(pAZZ50) expressing the complete S-fimbria II gene cluster of E. coli O18 adhered to cellular fibronectin (cFn) on glass but not to plasma fibronectin (pFn). Adhesion to cFn was specifically inhibited by neuraminidase treatment of cFn as well as by incubation of the bacteria with sialyl-alpha2-3-lactose, a receptor analog of the S fimbriae. No significant adhesion to cFn or pFn was detected with E. coli HB101(pAZZ50-67) expressing S fimbriae lacking the SfaS lectin subunit. Strain HB101(pAZZ50) also adhered to a human fibroblast cell culture known to be rich in cFn, and the adhesion was specifically inhibited in the presence of polyclonal antibodies to cFn. The results show that the SfaS lectin of the S fimbriae mediates the adherence of meningitis-associated E. coli to sialyl oligosaccharide chains of cFn.
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PMID:The cellular form of human fibronectin as an adhesion target for the S fimbriae of meningitis-associated Escherichia coli. 1022 41

The expression of carbohydrate antigens has been shown by retrospective immunohistochemical analysis to correlate to the progression and metastases of human cancers. However, the mechanisms of these changes of carbohydrate expression and the role of carbohydrates in the malignant behavior of tumor cells are not well known. In this article, we introduce methods to experimentally modify carbohydrate expression in tumor cells and to assess the involvement of these carbohydrate antigens in the malignant behavior of tumor cells. Modifications of the biosynthesis of O- and N-linked carbohydrates, and glycolipids are achieved by treating cultured tumor cells with culture media containing Benzyl-alpha-GalNAc, swainsonine, or D-PDMP, respectively. Enzymatic digestion of cell surface carbohydrates with sialidase, endo-beta-galactosidase or other glycosidases can also be performed. These cells can be used for short term experiments such as adhesion assays. However, modified carbohydrates may be recovered during in vitro and in vivo assays. By transfection of glycosyltransferase cDNA, or selection of tumor cells by binding lectins or antibodies, stable carbohydrate variant cells can be obtained which are suitable for long term experiments such as the experimental formation of metastases in vivo. The biological function of tumor cell surface carbohydrates may be diverse. These molecules are thought to influence adhesion interaction between tumor cells and the endothelial cells of target organs. However, carbohydrate recognition molecules, or lectins, are expressed on a variety of cells in the vascular system and in the immune system. Therefore, it is essential to design appropriate experimental models to study the biological significance of carbohydrate-lectin interactions in cancer progression and metastatic dissemination. Adhesion assays of tumor cells to selectin-transfected CHO cells were performed. Taking molecules other than selectins into consideration, adhesion assays using frozen tissue sections were also performed.
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PMID:[Tumor metastases and adhesion molecules carbohydrates and lectins]. 1041 Jan 58

The brain environment exerts a powerful influence on macrophage phenotype, as exemplified by microglia, but the mechanisms mediating this control are nuclear. Since adhesion molecules are known to transmit signals across cell membranes, we investigated adhesion receptors involved in macrophage interaction with brain tissue. We have demonstrated previously that macrophages adhere specifically to CNS neurones in an in vitro assay. Here we show that this adhesion is inhibited by lectins, including Griffonia simplicofolia isolectin B4 (GSI), which has been used as a microglial marker for many years. Adhesion is unaffected by antibodies to several known adhesion molecules but is markedly inhibited by a new monoclonal antibody: HB1. HB1 recognizes microglia in the normal brain and activated microglia and recruited monocytes during CNS pathology. It labels a subset of resident macrophages and recruited monocytes in other tissues. Using this antibody, we isolated a protein of about 110 kDa from macrophage cell lysates. This protein is recognized by GSI, providing the first evidence of a functional role for the antigen labelled by this lectin. Further study of the HB1 antigen may provide important information about the influence of the brain environment on the phenotype of monocytic cells.
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PMID:The monoclonal antibody HB1 recognizes an adhesion molecule for macrophages in the brain. 1065 79

Adhesion between the oocyte-cumulus complex and infundibulum plays an important, but poorly understood, role in oocyte pick-up. The purposes of this study were to determine which components of the oocyte-cumulus complex and oviductal epithelium function in adhesion, to measure adhesion under physiological conditions, and to examine the effect of modulation of adhesion on oocyte-cumulus complex pick-up rate. Oocyte-cumulus complexes containing an expanded matrix were readily transported into the oviduct, while unexpanded complexes lacking an extracellular matrix were not picked up, indicating that the matrix is necessary for pick-up. Transmission electron microscopy revealed that during pick-up, adhesion occurred specifically between the ciliary crowns of the oviduct and the granules and filaments of the cumulus matrix. An assay was developed using vacuum from a low-flow peristaltic precision pump, modified for bi-directional flow, to measure the strength of adhesion between the oocyte-cumulus complex and the oviductal epithelium, and adhesion was measured during physiological conditions. The lectin wheat germ agglutinin and the polycation poly-L-lysine were then used to modulate adhesion, and the effects of increasing or decreasing adhesion on oocyte pick-up rate and ciliary beat frequency were examined. The data show that 1) the matrix of the oocyte-cumulus complex and the ciliary crowns of the oviduct function in adhesion during pick-up and that adhesion is necessary for pick-up, 2) adhesion can be assayed quantitatively and is very uniform among control infundibula, and 3) decreasing or increasing adhesion decreases oocyte pick-up rate and in some cases prevents pick-up without affecting ciliary beat frequency.
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PMID:Assay and importance of adhesive interaction between hamster (Mesocricetus auratus) oocyte-cumulus complexes and the oviductal epithelium. 1068 98

Selectins mediate the initial tethering and rolling of leukocytes on vessel walls. Adhesion by selectins is a function of both ligand recognition at equilibrium and mechanical properties of the selectin-ligand bond under applied force. We describe an EGF domain mutant of L-selectin with profoundly augmented adhesiveness over that of native L-selectin but conserved ligand specificity. This mutant, termed LPL, was derived by a substitution of the EGF-like domain of L-selectin with the homologous domain from P-selectin. The mutant bound soluble carbohydrate L-selectin ligand with affinity comparable with that of native L-selectin but interacted with all surface-bound ligands much more readily than native L-selectin, in particular under elevated shear flow. Tethers mediated by both native and mutant L-selectin exhibited similar lifetimes under a range of shear stresses, but the rate of bond formation by the mutant was at least 10-fold higher than that of native L-selectin toward distinct L-selectin ligands. Enhanced rate of bond formation by the mutant was associated with profoundly stronger rolling interactions and reduced dependence of rolling on a threshold of shear stress. This is the first demonstration that the EGF domain can modulate the binding of the lectin domain of a selectin to surface-immobilized ligands under shear flow without affecting the equilibrium properties of the selectin toward soluble ligands.
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PMID:An activated L-selectin mutant with conserved equilibrium binding properties but enhanced ligand recognition under shear flow. 1074 85

Adhesion of bacteria to vascular endothelial cells as well as mucosal cells and epithelial cells appears to be one of the initial steps in the process of bacterial infection, including infective endocarditis. We examined whether lectin-like oxidized low-density lipoprotein receptor 1 (LOX-1), a member of scavenger receptor family molecules with C-type lectin-like structure, can support adhesion of Gram-positive and Gram-negative bacteria. Chinese hamster ovary-K1 (CHO-K1) cells stably expressing LOX-1 can support binding of FITC-labeled Staphylococcus aureus and Escherichia coli, which was suppressed by poly(I) and an anti-LOX-1 mAb. Adhesion of these bacteria to LOX-1 does not require divalent cations or serum factors and can be supported under both static and nonstatic conditions. Cultured bovine aortic endothelial cells (BAEC) can also support adhesion of FITC-labeled S. aureus, which was similarly suppressed by poly(I) and an anti-LOX-1 mAb. In contrast, binding of FITC-labeled E. coli to BAEC was partially inhibited by the anti-LOX-1 mAb, and poly(I) did not block FITC-labeled E. coli adhesion to BAEC, but, rather, enhanced it under a static condition. TNF-alpha increased LOX-1-dependent adhesion of E. coli, but not that of S. aureus, suggesting that S. aureus adhesion to BAEC may require additional molecules, which cooperate with LOX-1 and suppressed by TNF-alpha. Taken together, LOX-1 can work as a cell surface receptor for Gram-positive and Gram-negative bacteria, such as S. aureus and E. coli, in a mechanism similar to that of class A scavenger receptors; however, other unknown molecules may also be involved in the adhesion of E. coli to BAEC, which is enhanced by poly(I).
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PMID:LOX-1 supports adhesion of Gram-positive and Gram-negative bacteria. 1129 Jul 92

Adhesion of neutrophils to substrate is initiated by receptor-ligand interactions that induce outside-in signaling. Inside-out signals and lateral interactions between surface molecules further fine tune the response. This study investigates the role of CD66 in adhesion of neutrophils to fibronectin, using domain-mapped monoclonal antibodies to CD66. Neutrophils express CD66a, CD66b, and CD66c on their surface. The neutrophil surface molecules that bind to fibronectin are the alpha(4)beta(1) and alpha(5)beta(1) integrins. Our results show that the monoclonal antibody Kat4c, which recognizes the AB domain of CD66a, b, and c and the polyclonal anti-CD66 (anti-carcinoembryonic antigen), augments neutrophil adhesion to fibronectin, while monoclonal antibodies to the individual CD66 antigens, the Fab fragment of Kat4c, and a mixture of the individual antibodies to CD66 antigens were unable to affect the adhesion. Thus heterodimerization of CD66a, b, and c is required for promoting neutrophil adhesion to fibronectin. The increased adhesion in presence of Kat4c was inhibited by antibodies to the beta(1) and beta(2) integrins. Antibody ligation of CD66 antigens causes their clustering and concomitant coclustering of the alpha(M) subunit of the beta(2) integrin, thereby activating the integrin. The sugar alpha-methyl mannoside inhibited anti-CD66-mediated clustering, indicating that a carbohydrate-lectin interaction may exist between CD66 and alpha(M) integrin. It also reduced the increased adhesion of neutrophils to fibronectin, suggesting that beta(2) integrin activation precedes beta(1) integrin activation. Further, the anti-CD66-mediated adhesion to fibronectin is accompanied by increased localization of Src family kinases (lyn and hck) to the cytoskeleton and an increase in their kinase activity. These results suggest that crosslinking of CD66a, CD66b, and CD66c promotes activation of the beta(2) integrin and in turn an alteration in the affinity of the beta(1) integrin, which enhances the adhesion of neutrophils to fibronectin.
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PMID:Adhesion of neutrophils to fibronectin: role of the cd66 antigens. 1133 42

Adherence of the opportunistic pathogen Candida albicans to basement membrane (BM) proteins is considered a crucial step in the development of candidiasis. In this study the interactions of C. albicans yeast cells with the three main domains of type IV collagen, a major BM glycoprotein, were analysed. C. albicans adhered to the three immobilized domains by different mechanisms. Adhesion to the N-terminal cross-linking domain (7S) required the presence of divalent cations, whereas interaction with the central collagenous domain (CC) was cation-independent. Recognition of the C-terminal non-collagenous domain (NC1) was partially cation-dependent. Binding inhibition assays with the corresponding domains in soluble form showed that these interactions were specific. Both Ca(2+) and Mg(2+) promoted adhesion to the 7S domain and the interaction was completely abolished by EDTA. Treatment of the 7S domain, or its subunits, with N-glycosidase F reduced yeast binding by approximately 70%. Moreover, several sugars known to be part of the N-linked oligosaccharide chains of collagen IV inhibited adhesion to immobilized 7S; N-acetylglucosamine, L-fucose and methylmannoside caused a similar inhibition whereas N-acetyllactosamine was a more effective inhibitor. In contrast, glucose, galactose, lactose or heparan sulfate did not affect yeast binding. Combinations of the inhibitory sugars at suboptimal inhibition concentrations did not reduce C. albicans adhesion more than the individual sugars, pointing to a single lectin as responsible for the interaction. These results taken together show that C. albicans utilizes several adhesins for interacting with type IV collagen, and that at least one of them is a lectin which recognizes the 7S(IV) oligosaccharide residues as its receptor.
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PMID:Different adhesins for type IV collagen on Candida albicans: identification of a lectin-like adhesin recognizing the 7S(IV) domain. 1142 74

A novel C-lectin protein, lebecetin, was purified and characterized from the venom of Macrovipera lebetina. It is a disulfide-linked heterodimer of 15 and 16 kD. The subunits are homologous to each other and to the other snake venom proteins of the C-type (Ca(2+)-dependent) lectin superfamily. Lebecetin shows a potent inhibitory effect on whole blood and washed platelets induced by different agonists. It inhibits the agglutination of human fixed platelets in the presence of ristocetin. Lebecetin also interferes with the adhesion of IGR39 melanoma and HT29D4 adenocarcinoma cells. These two lines adhere to lebecetin used as matrix. Lebecetin is also able to strongly reduce IGR39 and HT29D4 cell adhesion to fibrinogen and laminin, but not to fibronectin and collagen types I and IV, respectively. Adhesion properties of lebecetin may thus involve integrin receptors.
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PMID:Lebecetin, a C-lectin protein from the venom of Macrovipera lebetina that inhibits platelet aggregation and adhesion of cancerous cells. 1191 Jan 82

Leukocyte diapedesis requires that Mac-1/CR3-dependent adhesion be regulated so that cells can move from one attachment site to another. The high affinity adhesion state of Mac-1/CR3 is generated when it forms a lectin-dependent complex with the receptor for urokinase plasminogen activator (uPAR; CD87). The extensively glycosylated uPAR binds to the same C-terminal lectin domain of CD11b that had previously been shown to prime Mac-1/CR3 for cytotoxic degranulation in response to beta-glucan. uPAR and beta-glucan compete for a lectin site that is near to the CBRM1/23 epitope (residues 943-1047) at the C-terminus of CD11b, and thus the lectin domain is critical to both the adhesion and cytotoxic functions of Mac-1/CR3. Adhesion is reversed when the uPA enzyme is captured by its receptor (uPAR), causing uPAR to bind to CD11b at a second site (residues 424-440) that is in between the N-terminal I-domain and the divalent cation binding region.
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PMID:Role of the lectin domain of Mac-1/CR3 (CD11b/CD18) in regulating intercellular adhesion. 1201 61


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