摘要
Lipopolysaccharide （LPS） is known to be a potent activator of mature B cells by signaling through Toll-like receptor 4 （TLR4）. Its impact on early B-cell development, however, is not well defined. When comparing to C3H/HeN mice, TLR4-mutant C3H/HeJ mice showed an increase in the number of pro-B and pre-B cells in the bone marrow. When cultured in the presence of IL-7, the proliferation of pro-B and large pre-B cells was significantly inhibited by LPS, possibly due to reduced IL-7 receptor-a （IL-7Ra） expression. Meanwhile, the generation of IgM＋/IgD＋ B cells was greatly enhanced in IL-7 cultures of pro-B and pre-B cells. Consistent with these results, treatment with LPS facilitated the progression of adoptively transferred B220＋IgM-IgD- precursors into IgD＋ cells. Overall, these data suggest that LPS has a profound influence on early B-cell development, which may contribute to the deregulated B-cell development under physiological and pathological conditions such as bacterial infections.
Lipopolysaccharide （LPS） is known to be a potent activator of mature B cells by signaling through Toll-like receptor 4 （TLR4）. Its impact on early B-cell development, however, is not well defined. When comparing to C3H/HeN mice, TLR4-mutant C3H/HeJ mice showed an increase in the number of pro-B and pre-B cells in the bone marrow. When cultured in the presence of IL-7, the proliferation of pro-B and large pre-B cells was significantly inhibited by LPS, possibly due to reduced IL-7 receptor-a （IL-7Ra） expression. Meanwhile, the generation of IgM＋/IgD＋ B cells was greatly enhanced in IL-7 cultures of pro-B and pre-B cells. Consistent with these results, treatment with LPS facilitated the progression of adoptively transferred B220＋IgM-IgD- precursors into IgD＋ cells. Overall, these data suggest that LPS has a profound influence on early B-cell development, which may contribute to the deregulated B-cell development under physiological and pathological conditions such as bacterial infections.
