Ontogenetic development of lipopolysaccharide-reactive B cells against bromelain-treated mouse erythrocytes in mouse lymphoid tissues.

In lymphoid tissues of mice, there exist LPS-reactive B cells which can differentiate to IgM-secreting plaque-forming cells (IgM-PFC) and PFC secreting antibodies against bromelain-treated mouse erythrocytes (BrMRBC) by LPS activation. In this study, four groups of LPS-reactive B cells in spleen, peritoneal cavity and mesenteric lymph nodes from 2- and 10-week-old mice were compared and enumerated as precursors of IgM-PFC and anti-BrMRBC PFC on days 1 and 2 after LPS activation in quantitative culture conditions. The induction of each of four PFC responses in peritoneal cells was sensitive to LPS and anti-mouse IgM antibodies as much as the induction of the respective PFC response in spleen cells. The ratios of four groups of PFC to each other were different among three tissues and between two ages. These findings support the view that the four groups of LPS-reactive B cells in each tissue are mostly in distinct subpopulations of B cells from each other, and the respective groups of different lymphoid tissues at different ages belong to the same subpopulation.