Effects of streptococcal preparation OK-432 on cytokine induction in spleen and tumour tissues of mice bearing MH-134 tumour cells

Streptococcal preparation OK-432 is a bacterial immunopotentiator extensive ly used in Japan for adjuvant cancer therapy. Using C3H/He mice bearing MH- 134 tumour cells, cytokine inductions of tumour necrosis factor-alpha, inte rleukin 1 beta, interleukin 6 and interferon-gamma were determined in splee n and tumour tissues by reverse transcriptase-polymerase chain reaction ana lysis. No significant induction of cytokine mRNA was observed after subcuta neous administration of OK-432 (OK-432, sc) or after intratumoural injectio n of IFN-gamma (IFN-gamma, it), compared with controls, either in spleen or tumour tissues. In contrast, subcutaneous administration of OK-432 followe d by intratumoural OK-432 injection (OK-432, sc+it) was found to induce som e cytokine mRNAs significantly. The mRNA levels of tumour necrosis factor a lpha and interferon-gamma in spleen tissue and those of interleukin 1 beta and interferon-gamma in tumour tissues were significantly elevated in mice with OK-432, sc+it treatment compared with controls. These results suggest that treatment with OK-432, sc+it effectively induced splenic antitumour im munity as well as local immunity against tumour cells.