Inhibition of proliferative and plaque-forming cell responses by human bone-marrow-derived lymphocytes from peripheral blood by antisera to the p23, 30 antigen.

Abstract

A recently described technique for the polyclonal induction of plaque-forming cells from human bone-marrow-derived (B) lymphocytes of peripheral blood was used to assess the role of a human Ia[immune response-associated]-like antigen (p23,30) in differentiation of human B cells. The effects of antisera to p23,30 on the plaque-forming cells and proliferative responses of human B cells stimulated by pokeweed mitogen or soluble products of activated human thymus-derived (T) cells were examined. Antisera to p23,30 eliminated the development of plaque-forming cells induced by T cell products and pokeweed mitogen. While these antisera also abrogated B cell proliferation induced by T cell supernatants, the proliferative response generated by pokeweed mitogen was only partially reduced. While the p23,30 antigen continues to be expressed on fully differentiated plaque-forming cells, antisera to this determinant exert inhibitory effects on B cell differentiation only when present during the early stages of B cell cultures. The analogy between p23,30 and murine Ia antigens was supported. A major role for this antigen in the early events involved in human B cell differentiation into antibody-forming cells was shown.