[Kinetics of antitumor immunity in experimental brain tumor].

Kinetics of the specific immune status was studied in experimental brain tumor of rats. To produce intracerebral tumors, the KEG-1. Cell line of mixed glioma induced by ethylnitrosourea in a WKA/HKM rat was inoculated into the caudate nucleus of the syngeneic rats with a stereotaxic technique. Such inoculation induced a 100% incidence of intracerebral tumors, and killed all the rats in about 20 days after the inoculation. The specific cellular immunity against KEG-1 was examined with a 51Cr-release cytotoxic assay at various stages of the tumor development . Cellular cytotoxic activity was observed from the 4th day after inoculation with KEG-1, and reached a peak on the 7th day and then declined as tumor growth until the death of the rats. Its activity was well correlated with the result of a tumor neutralization assay. The onset, peak, and decline of cellular cytotoxic activity corresponded closely to that of the cytotoxic antibody detected by a complement-dependent cytotoxic assay. The kinetics of the immune status in these brain tumor bearing rats were essentially similar to those in other tumor models. These results suggest that this brain tumor model may serve as a useful immunological parallel for the human brain tumor.