Contact interaction between lymphocytes is a general event following activation and is mediated by LFA-1.
When lymphocytes are activated in vitro, discrete cell-cell contacts are initiated which result in cluster formation. This contact interaction is found in syngeneic or allogeneic mixed leukocyte reactions as well as in mitogen-stimulated cultures (concanavalin A, periodate, lipopolysaccharide). T cells as well as B cells display the binding phenomenon. This activation-dependent lymphocyte-lymphocyte adhesion involves LFA-1, since monoclonal antibodies (including Fab fragments) against this molecule inhibit adhesion between clustering lymphocytes in a dose-dependent manner, whereas antibodies directed to several other cell surface antigens are inactive. Since a wide variety of functional interactions are inhibited by antibodies to LFA-1, it may be concluded that LFA-1-mediated cell contact is a discrete and essential step between a recognition event and the generation of functional activities by lymphocytes in general.
D000368:Aged; D000818:Animals; D000906:Antibodies / Q000276:immunology; D000954:Antigens, Surface / Q000276:immunology / Q000502:physiology*; D001402:B-Lymphocytes / Q000276:immunology*; D002449:Cell Aggregation; D002478:Cells, Cultured; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D016169:Lymphocyte Function-Associated Antigen-1; D051379:Mice; D008807:Mice, Inbred BALB C; D008808:Mice, Inbred CBA; D008819:Mice, Nude; D013601:T-Lymphocytes / Q000276:immunology*
D000906:Antibodies; D000954:Antigens, Surface; D007140:Immunoglobulin Fab Fragments; D016169:Lymphocyte Function-Associated Antigen-1