Effects of Corynebacterium parvum on tumour metastases in mice

Enhancement of concomitant immunity after radiation therapy and immunotherapy in a syngeneic murine tumour system

Concomitant immunity was evaluated in vivo towards a chemically induced epidermoid carcinoma transplanted in a syngeneic situation. Radiation therapy reversed the declining phase of concomitant immunity associated with tumour progression. The rejection rate of a challenge graft amounted to 82 and 95 per cent, respectively, 2 and 8 days after 25 Gy as compared with 55 and 43 per cent in unirradiated controls. Radiation induced immune recovery was dose related and proved to be different from restoration of immunity following surgical removal of the tumour. Immunotherapy with intraperitoneal injection of Corynebacterium parvum significantly improved concomitant immunity. Immunostimulation and irradiation at low dosage act synergistically on host anti-tumour resistance.

Effect of intravenous corynebacterium parvum on peripheral-blood effector cells of cancer patients

The i.v. administration of Corynebacterium parvum (CP) to patients who had recently undergone resection of colorectal tumours was found to have the following effects: 1. Polymorphonuclear leucocyte counts were raised 24 h after CP administration, while both lymphocyte and monocyte counts fell during this period. Polymorph and lymphocyte counts had returned to pre-infusion levels at one week, but monocyte counts were significantly increased at this time. 2. The lymphocyte mitotic response to PHA was reduced during the 24 h after CP infusion. 3 The spontaneous, antibody-induced, and PHA-induced lymphocyte-mediated cytotoxicity against a nucleated target cell fell significantly 3 h after CP infusion, but these functions recovered by 7 days. 4. A rise in serum lysozyme was found 3 and 24 h after CP administration. However, these increased levels were not maintained beyond 24 h.