Role of IgD in the immune response and tolerance. I. Anti-delta pretreatment facilitates tolerance induction in adult B cells in vitro.

Abstract

Adult spleen cells from C57BL.Ige mice, which generally are resistant to in vitro tolerance induction in the B[bone marrow-derived]-cell compartment, became hyporesponsive (tolerant) when cultured with antigen in the presence of an anti-allotype serum. Both antigen and anti-.delta. had to be present for this effect, which was hapten-specific and did not occur in C57BL/6 mice, which lack the Ig[immunoglobulin]5-1 allotype of the .delta.-chain detected in this system. Preculture with anti-.mu. serum plus antigen did not cause tolerance induction in adult spleen B cells of either strain. The surface IgD may act as a failsafe receptor to prevent tolerance induction in adult B cells. Tolerance studies with spleen cells from mice with markedly reduced numbers of IgD positive cells, because of a regimen of repeated injections of anti-.delta. serum beginning at birth (.delta.-suppressed mice), confirmed the importance of membrane IgD in preventing tolerance, because such .delta.-suppressed mice were hypersusceptible to tolerance by antigen alone. These studies suggest that acquisition of IgD is an important maturational step in the ability of murine B cells to discriminate tolerogenic and immunogenic signals.