Inhibition of growth of a murine sarcoma by immunization with chemically modified cells.

Sarcoma I cells from ascitic fluid of A/Ph mice were modified with iodoacetamide, diketene and glutaraldehyde. Syngeneic and allogeneic mice were immunized with the modified cells and the effect of this immunization on the growth or rejection of the native sarcoma injected intramuscularly into the hind leg was ascertained. The antitumour effect of the modified cells was compared with that of the irradiated ones. Only cells treated with iodoacetamide gave a better antitumour effect than the unmodified cells irradiated with a minimal dose of gamma irradiation capable of stopping the proliferation of these cells.