title: Abrogation of graft-versus-host reaction by dieldrin in mice.
abstract: Sublethal exposure to the organochlorine pesticide, dieldrin, decreased the T-cell immune response in mice. Indeed, a transient inhibition of the mixed lymphocyte reactivity (MLR) was noted at 7 days after intraperitoneal exposure to 0.6 LD50 dieldrin. The present study was undertaken to further investigate the effects of dieldrin on the T-cell immune response, using the graft-versus-host reaction (GVHR) as a model, in order to assess T-cell subset efficiency. Lymphoid cells of A/J mice injected intraperitoneally 7 days earlier with 36 mg/kg body weight dieldrin were transferred into H-2-incompatible F1 hybrids. With this model, known to induce a marked GVHR, we have observed that dieldrin inhibited the potential of parental cells to induce a GVHR in hybrid mice. This effect could not be attributed to a direct cell cytotoxicity, nor to the modulation of major T-cell subsets as shown by thymic and peripheral T-cell subpopulation analysis. Collaboration processes between these cellular subsets seem to represent a potential site for the dieldrin-induced suppression.
authors.affiliation: Institut Armand-Frappier, Laval-des-Rapides, Québec, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Hugo
authors.forename: J
authors.initials: J
authors.lastname: Bernier
authors.forename: K
authors.initials: K
authors.lastname: Krzystyniak
authors.forename: E F
authors.initials: EF
authors.lastname: Potworowski
authors.forename: M
authors.initials: M
authors.lastname: Fournier
mesh_terms: D000818:Animals; D004026:Dieldrin / Q000633:toxicity*; D005260:Female; D006087:Graft vs Host Reaction / Q000187:drug effects*; D007108:Immune Tolerance; D051379:Mice; D008810:Mice, Inbred C57BL; D013163:Splenomegaly / Q000139:chemically induced; D013601:T-Lymphocytes / Q000145:classification / Q000187:drug effects
chemical_list: D004026:Dieldrin