title: Mechanisms responsible for reduced in vitro immunoglobulin secretion in aged humans.
abstract: Age-related changes in the processes involved in T cell dependent polyclonal B cell activation in man were studied by comparing immunoglobulin (Ig) produced in autologous T:B (E+:E-) cell cultures of young and old donor pairs with Ig produced in crossover cultures. Each young and old donor was classified as a responder or a non-responder based on Ig levels in autologous pokeweed mitogen-activated T:B cultures. The data indicate that: (1) T suppressor influences are a major determinant of non-response in the young; (2) T cells of nonresponder old donors can support high levels of Ig secretion by young donors' B cells; (3) low response to pokeweed mitogen stimulation in the elderly may reflect either direct refractoriness of B cells to T cell dependent stimulation, heightened B cell sensitivity to suppressor signals, or a combination of the two.
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging; D001402:B-Lymphocytes / Q000276:immunology; D002478:Cells, Cultured; D006801:Humans; D007136:Immunoglobulins / Q000378:metabolism*; D008211:Lymphocyte Cooperation; D011043:Pokeweed Mitogens; D013601:T-Lymphocytes / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
chemical_list: D007136:Immunoglobulins; D011043:Pokeweed Mitogens