The growth of tumours in T-cell deprived mice and their response to treatment with Corynebacterium parvum.

Severe depletion of thym us-derived lymphocytes does not reduce, and may significantly increase, the resistance of mice to syngeneic tumours, although it grossly impairs their ability to reject alio transplants. Injection of killed C. parvum causes further inhibition of tum our growth in T-cell deprived mice to an extent comparable to th a t resulting from the same dose of G. parvum in normal mice. This appears to lend support to the hypothesis th a t the antitum our effect of C. parvum depends prim arily on macrophage stimulation.