Eradication of syngeneic tumor (Meth A fibrosarcoma) from mice by adoptive immunotherapy of immunized spleen cells induced by Corynebacterium parvum-pyridine extract residue.

Eradication of immunologically-syngeneic tumors was achieved by adoptive chemotherapy using effector cells induced by Corynebacterium parvum-Pyridine Extract Residue (CP-PER). A mixture of 2 X 10(6) Meth A cells and 0.1 mg CP-PER was subcutaneously inoculated into the back of donor BALB/c mice, with the result that their spleen cells showed an antitumor effect 10 to 13 days after the inoculation. These cells were used as immune cells. Recipient mice were inoculated with 1 X 10(6) Meth A cells, and 2 days later were administered cyclophosphamide. On the following day, 1 X 10(8) immune cells were adoptively transferred into the recipient mice. As a result, the tumor began to regress 7 to 12 days after the adoptive transfer. An immuno-histochemical study of the donors' spleens and the recipients' regressing tumors revealed that the ratio of L3T4+ T cells to Lyt-2+ T cells in the donors' spleens was increased and that the infiltrating cells in the recipients' tumors were mainly composed of L3T4+ T cells. This confirmed that the transfer of L3T4+ T cells led to the infiltration of L3T4+ T cells into the recipients' tumors, causing their eradication.