Effect of maleic anhydride-vinyl ether on the lymphocyte subpopulations of tumor-bearing, irradiated mice.

The splenic T- and B-lymphocyte populations of BALB/c mice were determined in Madison lung carcinoma 109-bearing animals. Concurrently, some groups of tumored mice were exposed to 500 rads of whole-body irradiation and were treated with one dose of maleic anhydride-vinyl ether (MVE). By direct immunofluorescence, it was found that the percentage of splenic T lymphocytes was significantly depressed in the tumored-irradiated mice. Mitogenic studies revealed that the T lymphocytes were more depressed in the tumored-irradiated mice than in the corresponding nonirradiated tumored mice. MVE was relatively effective in reconstituting the T-cell compartment of these splenic T lymphocytes. The B-cell compartment of the splenic lymphocytes of the tumored-irradiated mice was found to be extremely radiosensitive. Utilizing a specific anti-B serum, no B lymphocytes were detected during the testing. Blastogenic studies using lipopolysaccharide as the mitogenic probe revealed that the incorporation of 3H-TdR of the tumored-irradiated mice was just slightly higher than background values. MVE proved to be relatively ineffective in reconstituting the splenic B cells of the tumored-irradiated mice.