title: Mechanisms involved in age-dependent decline of immune responsiveness and apparent resistance against tolerance induction in C57BL/6 mice.
abstract: The plaque-forming antibody response of C57BL/6 mice to rabbit gamma globulin (RGG) decreases as a function of ae. RGG in tolerogenic form induces tolerance of young mice but sensitizes older animals. If antigen is administered together with lipopolysaccharide, the age-dependent decline in immune responsiveness is not observed, nor are older animals sensitized by tolerogen. The age-dependent decline in immune responsiveness is due to a loss of T helper capacity; sensitization by tolerogen is attributable to a subpopulation of B cells which becomes sensitized by the tolerogen. Older animals, treated with tolerogen, show a degree of central tolerance of T cells and a relatively slight, age-dependent diminution in colchicine- or cyclophosphamide-sensitive precursors of suppressor cells.
mesh_terms: D000375:Aging; D000818:Animals; D000917:Antibody Formation / Q000187:drug effects; D001402:B-Lymphocytes / Q000276:immunology; D003078:Colchicine / Q000494:pharmacology; D005260:Female; D007108:Immune Tolerance / Q000187:drug effects; D008070:Lipopolysaccharides / Q000494:pharmacology; D008211:Lymphocyte Cooperation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL / Q000276:immunology*; D011817:Rabbits; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D005719:gamma-Globulins / Q000276:immunology
chemical_list: D008070:Lipopolysaccharides; D005719:gamma-Globulins; D003078:Colchicine