title: Role of cell surface immunoglobulin in B-lymphocyte activation.
abstract: The role of cell surface immunoglobulin in helper T-cell-dependent B-cell activation was analyzed using a B-cell lymphoma, CH12, with known antigen specificity and activation properties similar to those of a resting B cell. Two sources of helper T cells were used, both selected such that they interact with H-2-encoded determinants on CH12 in the absence of the specific B-cell antigen, sheep erythrocytes. By this dissociation of the specificity of the T cells from that of the B cells, the requirement for antigen in the induction of CH12 to antibody secretion could be studied. The results show that both helper T-cell-B-cell interactions and surface immunoglobulin-antigen binding are involved in inducing B-cell differentiation, thus establishing a signalling function for the antigen receptor on B lymphocytes. Our data also show that the requirement for surface immunoglobulin-ligand interactions in B-cell activation can, under certain conditions, be circumvented, notably when high (nonphysiologic) multiplicities of T-cell help are used.
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D002454:Cell Differentiation; D002460:Cell Line; D002462:Cell Membrane / Q000276:immunology; D006183:H-2 Antigens / Q000276:immunology; D007136:Immunoglobulins / Q000276:immunology*; D008213:Lymphocyte Activation; D008223:Lymphoma / Q000276:immunology; D051379:Mice; D008815:Mice, Inbred Strains; D013045:Species Specificity; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
chemical_list: D006183:H-2 Antigens; D007136:Immunoglobulins