title: Organophosphorus pesticide immunotoxicity: effects of O,O,S-trimethyl phosphorothioate on cellular and humoral immune response systems.
abstract: The time course of immunosuppression induced by acute treatment with O,O,S-trimethyl phosphorothioate (OOS-TMP), an impurity in technical formulations of malathion, was examined in female C57B1/6 mice. Both cell-mediated and humoral immune responses were examined and included allospecific cytotoxic T cells, proliferative response to mitogens, interleukin-2 production and antibody production to sheep red blood cells. OOS-TMP pretreatment led to a reversible suppression of the generation of cytotoxic T lymphocytes and antibody-secreting cells to sheep erythrocytes. However, the mitogenic response of splenocytes from animals treated with nontoxic doses of OOS-TMP (as measured by body weight loss, serum cholinesterase levels and splenic lymphocyte number) to concanavalin A was not significantly suppressed, but the response to the B cell mitogen lipopolysaccharide was slightly decreased on day 1 following treatment. In contrast, interleukin-2 production was elevated by 24 h following treatment, but had returned to control levels by day 7. These data suggest that OOS-TMP was able to block the generation of cytotoxic T lymphocytes and antibody responses at doses of OOS-TMP that did not affect body weight or splenic lymphocyte number and this suppression was reversible.
mesh_terms: D000818:Animals; D000917:Antibody Formation / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005260:Female; D007111:Immunity, Cellular / Q000187:drug effects*; D007376:Interleukin-2 / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D063086:Organothiophosphates / Q000633:toxicity*; D009946:Organothiophosphorus Compounds / Q000633:toxicity*; D013602:T-Lymphocytes, Cytotoxic / Q000187:drug effects / Q000276:immunology
chemical_list: D007376:Interleukin-2; D063086:Organothiophosphates; D009946:Organothiophosphorus Compounds; C019123:O,O,S-trimethyl phosphorothioate