title: Selective immunosuppression resulting from exposure to the carcinogenic congener of benzopyrene in B6C3F1 mice.
abstract: B6C3F1 mice were exposed to two congeners of benzopyrene, either the carcinogen benzo(a)pyrene (B(a)P) or the non-carcinogen benzo(e)pyrene (B(e)P. Exposure of mice to B(a)P resulted in a reduced number of IgM and IgG antibody plaque forming cells (PFC) to the T-dependent (TD) antigen SRBC and IgM PFC's to the T-independent (TI) antigen LPS. The IgM response to hapten conjugated TI antigens was examined using TNP-LPS for reactivity of less mature B cells (B1) and TNP-Ficoll for more mature B cells (B2). Exposure to B(a)P severely depressed the TNP-Ficoll PFC response by up to 77% without altering the TNP-LPS response. These data indicated that exposure to B(a)P alters differentiation and antibody production in mature B cells to both TD and B2 TI antigens. No change in PFC was observed following exposure to B(e)P. Mishell-Dutton co-cultures confirmed that B cells were affected and that T helper cells or suppressor Mphi were not involved. Parameters of cell-mediated immunocompetence including delayed cutaneous hypersensitivity to KLH, allograft or tumour cell rejection and susceptibility to Listeria monocytogens were unaltered in B(a)P treated mice.
mesh_terms: D000818:Animals; D000917:Antibody Formation / Q000187:drug effects*; D001564:Benzo(a)pyrene; D001580:Benzopyrenes / Q000494:pharmacology*; D002273:Carcinogens / Q000494:pharmacology; D005260:Female; D006462:Hemolytic Plaque Technique; D007111:Immunity, Cellular / Q000187:drug effects*; D007074:Immunoglobulin G / Q000096:biosynthesis; D008088:Listeriosis / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects; D008214:Lymphocytes / Q000276:immunology; D051379:Mice; D008815:Mice, Inbred Strains; D012513:Sarcoma, Experimental / Q000276:immunology
chemical_list: D001580:Benzopyrenes; D002273:Carcinogens; D007074:Immunoglobulin G; D001564:Benzo(a)pyrene; C026487:benzo(e)pyrene