Altered levels of mononuclear leukocytes in tumor-bearing rats: decrease of helper T lymphocytes and increase of suppressor cells.
In the spleen and peripheral blood of BN rats with progressive tumors, W3/25+ T helper cells were significantly reduced and OX8+ T suppressor/cytotoxic cells were significantly increased. The ratio of helper to suppressor elements was decreased to 1.6 from a ratio of 3 in normal BN rats without tumors, and this decreased ratio correlated with tumor growth. When tumors were eliminated in vivo by infusion of effector cells (W3/25+ T lymphocytes), the levels of W3/25+ and OX8+ T cells returned to normal and the ratio of helper to suppressor/cytotoxic cells in the spleen and peripheral blood reverted to 3.0 or higher. Macrophages and null cells, T-sIg-, were also elevated in the spleen and peripheral blood of rats bearing expanding tumors and returned to normal levels after cure. Assays of spleen cells for cell-mediated cytotoxicity in rats with large tumors revealed little or no specific cytotoxicity. Cytotoxic activity was high in spleen of rats cured of their neoplasms by infusion of helper cells.
D000818:Animals; D003602:Cytotoxicity, Immunologic; D007958:Leukocyte Count; D009000:Monocytes / Q000276:immunology*; D051381:Rats; D011914:Rats, Inbred BN; D012513:Sarcoma, Experimental / Q000276:immunology*; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D013997:Time Factors