title: Human B-lymphocyte colony responses: suboptimal colony responsiveness in aged humans associated with defective function of B cells and monocytes.
abstract: The abilities of human B cells from young and aged subjects to form colonies in semisolid cultures stimulated with Staphylococcus protein A were investigated. Approximately three-fourths of aged adults had significantly diminished colony responses compared to young adults. In 55% of these aged adults, the in vitro blocking of monocyte prostaglandin synthesis lead to a 1.5-fold or greater augmentation of the depressed colony responses. Other experiments showed that the improvement with indomethacin could not be explained by the greater sensitivity of aged versus young B-cell colony precursors to prostaglandin suppression. However, indomethacin failed to improve the depressed colony responses of the remaining aged adults. This failure could not be attributed to deficient interleukin 1 production, detectable alterations in accessory cell subsets of monocytes, or the lack of potential colony precursors bearing sIgD/M. Instead, the B cells from these aged subjects demonstrated a substantial decrease in the capping of sIgD/M compared to the B cells of aged subjects which displayed improved colony responses with indomethacin and compared to the B cells from young adults. Thus, these data indicate that the diminished B-cell colony responses of aged humans represent aberrancies within both the B-cell and monocyte lineages which might coexist.
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging; D000527:Alprostadil; D001402:B-Lymphocytes / Q000276:immunology*; D002999:Clone Cells; D006801:Humans; D007152:Immunologic Capping; D007213:Indomethacin / Q000494:pharmacology; D007375:Interleukin-1 / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000187:drug effects; D009000:Monocytes / Q000276:immunology*; D011458:Prostaglandins E / Q000494:pharmacology; D011947:Receptors, Antigen, B-Cell / Q000032:analysis; D011961:Receptors, Fc / Q000032:analysis
chemical_list: D007375:Interleukin-1; D011458:Prostaglandins E; D011947:Receptors, Antigen, B-Cell; D011961:Receptors, Fc; D000527:Alprostadil; D007213:Indomethacin