Peripheral B cell maturation. I. Immature peripheral B cells in adults are heat-stable antigenhi and exhibit unique signaling characteristics.
Whether recently generated peripheral B cells in adults are functionally equivalent to immature B cells in the neonatal spleen is unknown. We have identified a splenic B cell subpopulation in adults whose phenotypic and in vitro characteristics closely resemble those of neonatal B cells. These cells are defined by the cell surface phenotype heat-stable Aghi (HSAhi), and make up 10 to 15% of the adult splenic B cell pool. HSAhi B cells in adults bear the immature phenotype B220lo sIgMhi, and are 50% sIgD+. Furthermore, after sublethal irradiation, the initial wave of newly generated splenic B cells in self-reconstituting adults express a similar phenotype. In keeping with previous data on neonatal B cells, HSAhi cells from either normal or self-reconstituting mice are refractory to stimulation with anti-IgM antibodies, yet proliferate upon LPS stimulation, and generate primary antibody responses if given appropriate T cell help. In contrast to neonatal cells, HSAhi adult B cells are refractory to stimulation with PMA plus ionomycin. Together, these data suggest that peripheral HSAhi B cells in adults correspond to recently generated B cells, whose signaling characteristics are distinct from previously described B cell subsets.
Allman
D M
DM
Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadephia 19104-6082.
Ferguson
S E
SE
Cancro
M P
MP
D000818:Animals; D000831:Animals, Newborn / Q000276:immunology; D000917:Antibody Formation; D000954:Antigens, Surface / Q000032:analysis*; D001402:B-Lymphocytes / Q000502:physiology*; D002478:Cells, Cultured; D006358:Hot Temperature; D007075:Immunoglobulin M / Q000502:physiology; D015759:Ionomycin / Q000494:pharmacology; D017493:Leukocyte Common Antigens; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D013601:T-Lymphocytes / Q000502:physiology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D000954:Antigens, Surface; D007075:Immunoglobulin M; D015759:Ionomycin; D017493:Leukocyte Common Antigens; D013755:Tetradecanoylphorbol Acetate