[Antitumor effect of Corynebacterium parvum]

The protective effect produced by pre-treatment with C. parvum is studied in two syngeneic tumours: mammary carcinoma in C3H mice and lymphosarcoma in XVII mice. The best anti-tumour effect is obtained when both C. parvum and tumour cells are injected by the same route, which, however varies for the two tumours. The study of the recovery of C. parvum protective effect after its suppression by a sub-letal dose of x-irradiation shows that, in the C3H mice, it is parallel to the restoration of the antibody response. On the contrary, in XVII mice, the recovery of the protection is obtained in mice still immunologically suppressed.