title: Restoration of in vitro immune responsiveness of mastocytoma-suppressed splenocytes by activated T cells.
abstract: Spleen cells from normal DBA/2 mice pretreated with a soluble factor from mastocytoma cells or from ascitic fluid of mastocytoma-bearing mice were markedly impaired in terms of antibody formation to SRBC in vitro. Such immunosuppression by mastocytoma homogenates or ascitic fluid was reversed when syngeneic T cells activated to SRBC were added to the cultures, but not when peritoneal exudate cells or anti-theta-treated normal splenocytes were used. Activated T cells, as well as normal B lymphocytes prepared from spleens of lethally irradiated mice reconstituted with bone marrow cells, were less sensitive to the immunosuppressive factor than non-activated T cells. The ability of educated T cells to restore immunocompetence of suppressed spleen cells in vitro suggests that the target of the immunosuppressive factor from mastocytoma cells may be non-activated T cells, especially those involved in T cell helper function.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D000921:Antibody-Producing Cells; D000941:Antigens; D001202:Ascitic Fluid / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology; D002478:Cells, Cultured; D004912:Erythrocytes / Q000276:immunology; D005260:Female; D006462:Hemolytic Plaque Technique; D007114:Immunization; D007165:Immunosuppression Therapy; D012515:Mast-Cell Sarcoma / Q000276:immunology*; D051379:Mice; D008811:Mice, Inbred DBA; D010537:Peritoneum / Q000166:cytology; D011830:Radiation Effects; D012756:Sheep / Q000276:immunology; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000528:radiation effects
chemical_list: D000941:Antigens