INCREASED SERUM IGG1 LEVELS AND REDUCED NUMBERS OF B-1 B-CELLS IN DBA2J MICE/

B-cell heterogeneity studies have historically focused upon BALB/c mic e and their derivatives. In contrast, the B cells of DBA/2J mice, a pr ototype strain for the study of the endogenous minor lymphocyte stimul atory (Mls) viral superantigen Mls-1(a), have not been extensively inv estigated. DBA/2J B cells, by functioning as Mls-1(a) antigen-presenti ng cells, influence their own differentiation and diversity by inducin g the proliferation and differentiation of specific CD4 T-cell subsets . In this report, the B cells of DBA/2J and BALB/c mice were compared for their ability to restore B-cell function in severe combined immuno deficient (SCID) recipients. Although spleen and bone marrow cells fro m these strains exhibited similar restoration of serum IgM production, the transfer of DBA/2J B cells into SCID mice led to greater IgG1 pro duction. The peritoneal cells of DBA/2J mice consisted of a lower perc entage of B-1 B cells and were less capable of restoring B-cell functi on after transfer into SCID recipients. These differences are discusse d with respect to the possible role of viral superantigens in influenc ing B-lymphocyte diversity.