T and B lymphocyte populations of tumor-bearing mice treated with 1,3-bis(chloroethyl)-1-nitrosourea (BCNU) or pyran

The immunostimulator pyran copolymer and the antitumor agent 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) have been studied to determine their effect on T and B lymphocytes from BALB/c mice bearing a syngeneic tumor, Madison lung 109 carcinoma. Indirect immunofluorescent and mitogenic assays revealed that the tumor-bearing controls usually had T and B cell populations lower than those observed for the normal controls. The tumor-bearing group treated with BCNU generally had T and B cell levels lower than the tumor controls. The administration of pyran resulted in an increase of T cells and a temporary increase in the B cell population. Although this increase in the B cell population of tumor-bearing mice treated with pyran is higher than that seen for the untreated tumor controls it was never higher than in the normal control mice. The experimental results indicate that pyran appears to reconstitute the depressed T cell population and has a transitory effect on the B cell population resulting from tumor burden.