RESTORATION OF CYCLOPHOSPHAMIDE-INDUCED SUPPRESSION OF THYMUS-DERIVED CYTOTOXIC-CELL GENERATION BY NORMAL THYMOCYTES

  • 1 January 1979
    • journal article
    • research article
    • Vol. 39  (9) , 3647-3654
Abstract
Spleen cells from mice treated with cyclophosphamide (100-200 mg/kg) were unable to generate effective cytotoxic thymus-derived cells to allogeneic tumor cells [lymphoma EL-4 cells and mastocytoma P815-X2 cells] in vitro. The inability of lymphoid cells from cyclophosphamide-treated mice to generate thymus-derived cytotoxic cells became more apparent as the number of responding cells became limited. This depressed response was not due to the elimination of cytotoxic precursor cells since normal response levels were restored by the addition of thymus cells. The added thymus cells did not provide cytotoxic cells in the culture. The thymus cells active in restoring cytotoxic activity were sensitive to mitomycin C, cyclophosphamide and anti-.theta. serum and complement. In addition, the active thymus cells were located in the cortisone-resistant pool and did not adhere to nylon wood columns. [Cyclophosphamide is a nonspecific alkylating agent used as a cytoreductive drug in the control of neoplasia.].