title: In vitro expression of secondary antitumor immunity by in vitro tumor-sensitized T cells: inhibition by tumor-induced suppressor T cells.
abstract: In vitro cultivation of memory immune cells from P815- or P388-immune mice with corresponding irradiated tumor cells induced generation of cytolytic T cells (CTL). The induction of CTL generation, as well as the cytolytic activity itself, was tumor-specific. The in vitro generation of CTL from P815- or P388-immune cells was suppressed by spleen cells from mice bearing corresponding progressive tumors (tumor size 15 mm). The tumor-induced suppressor cells suppressed the in vitro generation of CTL, but did not affect their cytolytic function. The suppression was tumor-specific and was mediated by Ly1+2-L3T4+ T cells. Treatment of suppressor cell donors with cyclophosphamide or sublethal gamma-radiation completely abolished the ability of their spleen cells to inhibit the in vitro CTL generation.
mesh_terms: D000818:Animals; D003520:Cyclophosphamide / Q000494:pharmacology; D003864:Depression, Chemical; D005720:Gamma Rays; D007108:Immune Tolerance / Q000187:drug effects / Q000528:radiation effects; D007114:Immunization; D007156:Immunologic Memory; D007941:Leukemia P388 / Q000276:immunology*; D007942:Leukemia, Experimental / Q000276:immunology*; D008297:Male; D012515:Mast-Cell Sarcoma / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D013154:Spleen / Q000637:transplantation; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000637:transplantation*
chemical_list: D003520:Cyclophosphamide