Supernatant from a cloned helper T cell stimulates resting B cells to express transferrin and IL-2 receptors.
We describe the properties of the supernatant from a murine cloned helper T cell (clone 52.3) which is able to polyclonally activate most resting B cells in the absence of any additional stimulus. We hypothesize that an activity which we call BCAF (B-cell-activating factor(s] exists in our supernatant which can activate resting B cells alone or in conjunction with other lymphokines. In the present report, we investigate changes in the surface antigen pattern induced on resting B cells by BCAF-containing supernatant. Analysis of the cells by flow cytometry shows that transferrin receptor and IL-2 receptor expression increase on a large fraction of B cells after 2 days of activation by the T-helper-cell clone supernatant. Monoclonal anti-transferrin receptor antibody inhibits cell division but does not affect blastogenesis, while IL-2 has no effect in our experimental system. Our present results confirm that BCAF-containing supernatants can act on most resting B cells and replace helper T cells in inducing B-cell activation and proliferation.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D002455:Cell Division; D007376:Interleukin-2 / Q000494:pharmacology; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000276:immunology*; D051379:Mice; D008811:Mice, Inbred DBA; D011971:Receptors, Immunologic / Q000276:immunology / Q000378:metabolism; D015375:Receptors, Interleukin-2; D011990:Receptors, Transferrin / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
D000911:Antibodies, Monoclonal; D007376:Interleukin-2; D008222:Lymphokines; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D011990:Receptors, Transferrin; D011994:Recombinant Proteins