Study of the mechanism of Corynebacterium parvum anti-tumour activity. I. Protective effect on the growth of two syngeneic tumours.

The protective effect of C. parvum against two different tumours - a lymphosarcoma and a mammary carcinoma - has been demonstrated. In the case of lymphosarcoma, a significant protective effect was obtained when both C. parvum and tumor cells were injected IV. In contrast in C3H mice the best protection was obtained when both C. parvum and mammary carcinoma cells were injected IP. Thus both C. parvum and tumour cells must be inoculated by the same route which, however, varies for different tumours. A very small dose of C. parvum still inhibited the growth of the two tumours. Splenectomy performed before C. parvum treatment did not interfere with the anti-tumour activity of C. parvum on the tumours. However, when splenectomy was performed after C. parvum injection, the protective ffect of C. parvum still persisted against XVII lymphosarcoma but not against C3H carcinoma.