Enhancement by LPS of B-cell function in genetically deficient mice.

CBA/N mice are apparently deficient in mature B cells, but not in immature B cells. Experiments reported here were designed to test the ability of the adjuvant and B-cell mitogen, bacterial lipopolysaccharide (LPS), to induce B-cell function in CBA/N mice. CBA/N spleen cells, which respond poorly to erythrocyte antigens in vitro, developed high numbers of hemolytic antibody-forming cells when cultured with LPS. When injected along with erythrocyte antigens, LPS enhanced in vivo immune responses, as shown by increases in direct and indirect hemolytic antibody-forming cells. These data demonstrate that both in vivo and in vitro, in the presence of LPS, CBA/N B cells can become antibody-forming cells.