The influence of anti-theta-globulin treatment on the growth of mastocytoma in mice.

DBA/2 mice were treated with four successive subcutaneous injections of rabbit anti-theta-gamma-globulin followed by the subcutaneous implantation of chemically induced mastocytoma (P-815-X2). Another series of animals received rabbit anti-thymus-gammaglobulin according to the same schedule and still another series of animals served as non-treated controls. A definite augmentation of the tumor growth, as evidenced by the dissemination of the tumor into the spleen, liver and kidney, was evident in the globulin-treated series. Such dissemination was not observed in the control animals, where the metastases were limited to the reginal lymph nodes. The studied gammaglobulins were different in two important respects; the death rate of animals and the frequency of thymic metastases were higher in the anti-theta-globulin series. These findings advocate the conclusion that anti-theta-globulin, prepared against the brain tissue, is the more specific and more potent T-lymphocyte suppressor of these two globulins studied. T-lymphocyte population seems to play an important role in host resistance against experimental neoplasia.