Cytofluorographic analysis of pokeweed mitogen-stimulated human peripheral blood cells in culture: age-related characteristics.
By use of monoclonal antibodies and flow cytometry techniques, peripheral blood mononuclear cells from young (20-30 years) and elderly (70+ years) subjects were analyzed before and after culture with pokeweed mitogen to gain insight into the cellular interactions responsible for the decreased B cell response observed in culture samples from the elderly. Data analysis of surface immunoglobulin-positive cells demonstrated no difference in the percentage of B cells in the  elderly, while both plaque-forming cell and intracytoplasmic immunoglobulin assays showed significantly reduced B cell maturation (P = less than 0.01) compared with young controls. The B cell defect was shown to be functional and not a result of failure to proliferate and survive during incubation. Surface marker analysis of T cell subpopulations demonstrated a definite shift (P = less than 0.01) in the helper/suppressor T cell ratio in cultured samples from the elderly group (3.9) compared with young subjects (1.2). In addition to the absolute increase in the helper T cell population, forward-angle light scatter analysis demonstrated that, compared with young controls, a greater portion of the helper T cell population in the elderly subjects had characteristics of activated, blast-sized cells. The data reported in this study suggest that in the elderly group there is a functional immunoregulatory imbalance in the helper T cell subset.
D000328:Adult; D000368:Aged; D000375:Aging; D000911:Antibodies, Monoclonal / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D007958:Leukocyte Count; D007962:Leukocytes / Q000276:immunology*; D009000:Monocytes / Q000276:immunology; D011043:Pokeweed Mitogens / Q000494:pharmacology; D013601:T-Lymphocytes / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
D000911:Antibodies, Monoclonal; D011043:Pokeweed Mitogens