レンサ球菌由来リボタイコ酸関連分子の抗腫瘍免疫活性の解析とその口腔癌治療への応用に関する研究

摘要

OK-432, a penicillin-killed and lyophilized preparation of a low-virulence strain (Su) of Streptococcus pyogenes (group A), is successfully used as an immunotherapeu-tic agent in many types of malignancies including oral cancer. Recently, we succeeded in isolating the effective molecule (lipoteichoic acid-related molecule OK-PSA) by affinity chromatography of a butanol extract of OK-432 on CNBr-activated sepharose 4B bound TS-2 monoclonal antibody that neutralizes the interferon-y-inducing activity of OK432. In this review, we describe the findings regarding the effect of OK-432 and OK-PSA in enhancing anti-tumor immunity and the molecular mechanism. Our in vitro and in vivo study demonstrated that OK-PSA induced Thl-type cytokines in humans as well as in mice, and elicited antitumor effect in tumor-bearing mice.