Stimulation of B lymphocytes through surface Ig receptors induces LFA-1 and ICAM-1-dependent adhesion.
Engagement of the surface Ig receptor with anti-IgM antibodies stimulates murine B lymphocytes to markedly increase their expression of the cell adhesion molecules ICAM-1 and LFA-1. Stimulated B cells display increased homotypic adhesiveness and form spontaneous heterotypic conjugates with T lymphocytes. This latter T-B cell interaction is further enhanced if T cells have been previously activated with phorbol esters. In all cases, the formation of cell-cell conjugates is dependent on LFA-1-ICAM-1-mediated interactions as assessed in mAb blocking experiments. B lymphocytes stimulated with anti-IgM display a marked increase in binding to ICAM-1-transfected L cells. This cell-cell interaction is inhibited by anti-LFA-1 mAb binding to the B lymphocyte. Together, these results demonstrate that there is an induction of both ICAM-1 and LFA-1 on stimulated B cells and a corresponding increase in the adhesiveness of these cells. These findings suggest that Ag binding to the surface Ig receptor could prepare a B lymphocyte for subsequent interaction with a T lymphocyte. This provides insight into how efficient T-B collaboration may occur between very infrequent Ag-specific lymphocytes.
Department of Pathology, Harvard Medical School, Boston, MA.
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D000818:Animals; D015703:Antigens, CD / Q000502:physiology*; D001402:B-Lymphocytes / Q000276:immunology*; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000032:analysis / Q000502:physiology*; D002449:Cell Aggregation; D007075:Immunoglobulin M / Q000276:immunology; D018799:Intercellular Adhesion Molecule-1; D008213:Lymphocyte Activation; D016169:Lymphocyte Function-Associated Antigen-1 / Q000032:analysis / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000502:physiology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D015703:Antigens, CD; D015815:Cell Adhesion Molecules; D007075:Immunoglobulin M; D016169:Lymphocyte Function-Associated Antigen-1; D011947:Receptors, Antigen, B-Cell; D011971:Receptors, Immunologic; D018799:Intercellular Adhesion Molecule-1; D013755:Tetradecanoylphorbol Acetate