Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0001511 (Adhesion)
 5,955 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cell to cell interaction play a major role in the induction of a immune response. NK cells represent a special lymphoid subset which displays its cytotoxic function without the engagement of MHC system. In order to investigate the role of different adhesion molecules in the mechanism of binding of the NK cell to the classic tumor target K562 cell, we have employed different unclustered mAbs of the Adhesion session (5th "CD" Workshop, Boston 1993) mostly of the CAM (cell adhesion molecule) subpanel. After their reactivity characterization both on lymphocytes and K562 cells, those that demonstrate reactivity against the tumor target were tested in the binding assay. The target was pretreated with the monoclonal in order to block a possible reacting molecule for the effector. Then, after the incubation of lymphocytes with PE-labelled anti CD16 mAb, their ability to bind to the target was tested in flow. While the majority of the mAbs did not induce any significant change in the binding capacity of the NK subset, few of them did, and precisely anti-CD58 (LFA-3) and anti-CD54 (ICAM-1) which showed different level of inhibition, particularly drastic with S002, S083 and S100. Other mAbs, such as the S011 (anti-CD59), due to the presence of the PI-linked glycoprotein recognized on both target and effector membranes, and to its capacity to stimulate NK activity, produced a total binding of the NK population. The coincubation of targets with anti-CD54 and anti-CD58 allowed to reduce at the lowest level this function. This data seem to support the hypothesis of specific surface molecules involved in the binding process of the NK cell, after recognition of the target.
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PMID:Inhibition of NK binding to K562 cells induced by MAb saturation of adhesion molecules on target membrane. 854 16

Lipid rafts are small laterally mobile microdomains that are highly enriched in lymphocyte signaling molecules. GM1 gangliosides are a common lipid raft component and have been shown to be important in many T-cell functions. The aggregation of specific GM1 lipid rafts can control many T-cell activation events, including their novel association with T-cell integrins. We found that clustering GM1 lipid rafts can regulate beta1 integrin function. This was apparent through increased resistance to shear flow-dependent detachment of T cells adherent to the alpha4beta1 and alpha5beta1 integrin ligand fibronectin (FN). Adhesion strengthening as a result of clustering GM1 enriched lipid rafts correlated with increased cellular rigidity and morphology through the localization of cortical F-actin, the resistance to shear-induced cell stretching, and an increase in the surface area and symmetry of the contact area between the cell surface and adhesive substrate. Furthermore, clustering GM1 lipid rafts could initiate integrin 'inside-out' signaling mechanisms. This was seen through increased integrin-cytoskeleton associations and enhanced soluble binding of FN and VCAM-1, suggesting the induction of high-affinity integrin conformations. The activation of these adhesion-strengthening characteristics appears to be specific for the aggregation of GM1 lipid rafts as the aggregation of the heterogeneous raft-associated molecule CD59 failed to activate these functions. These findings indicate a novel mechanism to signal to beta1 integrins and to activate adhesion-strengthening processes.
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PMID:Clustering T-cell GM1 lipid rafts increases cellular resistance to shear on fibronectin through changes in integrin affinity and cytoskeletal dynamics. 1913 60