Immunological and antitumour effects of corynebacterium parvum
Scott, Martin T
Experimental studies of the immunological and antitumour effects of the anerobic diptheroid bacterium Corynebacterium parvum are described.C. parvum injected systemically into mice resulted in potent stimulation of the lymphoreticular system and augmented humoral immunity; however, cell mediated immunity was suppressed. The C. parvum activated macrophage was determined to be the basis for all these phenomena, exerting both stimulatory and inhibitory effects.Using mouse tumour models both systemically and locally injected C. parvum could be manipulated to achieve therapeutic effects. The form of antitumour immunity generated varied according to the particular C . parvum tumour antigen interaction; following systemic injection, the reuslting antitumour activity was immunologically non specific and mediated directly be activated macrophages, whereas after local interaction of C. parvum with tumour antigen strong specific cell mediated antitumour immunity resulted.Subsequent experimental studies were designed to elucidate further these stimulatory and antitumour effects of C. parvum with a view to providing a rational basis for the clinical evaluation of C. parvum against human cancer. These have comprised:- (a) Manipulation of dose, route and time of C. parvum injection. (b) Tissue distribution studies following injection of labelled C. parvum preparations. (c) The role of immunity against C. parvum in its antitumour effects. (d) The principles of combining C. parvum immunotherapy with conventional anti-cancer chemotherapy. (e) Analyses of the active component of C. parvum.