title: Resistance of T suppressor cells to cyclophosphamide administration in total-lymphoid-irradiated mice.
abstract: The effect of administration of cyclophosphamide (Cy) on the susceptibility of mice to tolerance induction and its influence on the rate of induced T suppressor cells in antigen-specific and nonspecific systems was assessed using mice that had undergone total lymphoid irradiation (TLI). Tolerance to bovine serum albumin (BSA) was induced in adult mice conditioned by a short course of fractionated total lymphoid irradiation with an injection of nondeaggregated BSA; Cy was administered upon termination of TLI, two days prior to administration of the tolerizing antigen. Susceptibility to tolerance induction and rate of induced T suppressor cells were assessed one month later. Cy-treated TLI mice and mice treated with TLI alone did not respond to a challenge with DNP-BSA in complete Freund's adjuvant, whereas a good response was obtained to an unrelated protein antigen. The induced T suppressor cell rate was measured by inhibition of a secondary anti DNP-BSA response in an adoptive transfer system. The rate of non-antigen-specific T suppressor cells was measured by inhibition of the mixed leukocyte reaction with Concanavalin A-induced T suppressor cells obtained from spleen cells of TLI-treated, or Cy-treated mice, or those given both treatments. The results reveal that Cy treatment of TLI-conditioned mice does not reduce the rate of induced of T suppressor cells in antigen-specific and antigen-nonspecific systems.
mesh_terms: D000818:Animals; D003520:Cyclophosphamide / Q000494:pharmacology*; D005260:Female; D007108:Immune Tolerance; D008221:Lymphoid Tissue / Q000528:radiation effects*; D008297:Male; D051379:Mice; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects*; D014965:X-Rays
chemical_list: D011948:Receptors, Antigen, T-Cell; D003520:Cyclophosphamide