Tumoricidal effect of human PBMC following stimulation with OK-432 and its application for locoregional immunotherapy in head and neck cancer patients.

Both cell-mediated and cytokine-mediated antitumor activities were induced in peripheral blood mononuclear cells (PBMC) in short-term culture with streptococcal preparation, OK-432. Kinetic analysis of OK-432-activated killer activity (OKAK) showed that it reached a plateau level much faster (by 48 h of culture) than that detected in PBMC stimulated with recombinant interleukin 2 (rIL-2) (lymphokine-activated killer: LAK). We also found that the tumor growth inhibitory factor (TGIF) activity was produced in the culture supernatant (CSN) of the OK-432-activated PBMC (OK-MC) and the activity synchronously increased with augmentation of OKAK activity. The TGIF activity was rarely found in the CSN of rIL-2-stimulated PBMC. The TGIF activity detected in CSN of OK-MC was further characterized as derived from a cytokine different from interferon gamma (IFN gamma), tumor necrosis factor (TNF), or lymphotoxin (LT) by a neutralization test using monoclonal antibodies to these cytokines. These 48-h-cultured-OK-MC were adoptively transferred (adoptive immunotherapy: AIT) into 19 head and neck cancer patients either alone or in combination with chemotherapy and/or radiation therapy, and their therapeutic effects were examined. AIT was performed by intra-arterial or intratumoral administration of OK-MC. There were no significant side effects observed in this treatment. In these patients, approximately 1-10 x 10(7) cells were transferred into the tumor burden. Of the 19 patients, 17 had primary cancer, and in 6 (6/17;35%) of them complete remission (CR) of the tumor was obtained. Partial remission (PR) was attained in 9 of the 17 patients (9/17; 53%), giving the overall response rate of 88%.(ABSTRACT TRUNCATED AT 250 WORDS)