Interleukin-1 inducing activity of a streptococcal preparation OK-432 and its fractions by human monocytes.

Interleukin-1 (IL-1) inducing activity of a streptococcal preparation OK-432 and its fractions by monocytes were investigated in patients with lung cancer and healthy subjects. The results showed that cell free extracts and cell wall fractions of OK-432 were the strong IL-1 inducing fractions. IL-1 activity released by OK-432-stimulated monocytes of patients with lung cancer fell within normal range. OK-432 stimulated intracellular IL-1 synthesis as well as extracellular release by monocytes. These results, therefore, suggested that OK-432 immunotherapy in patients with malignant diseases might be effective by increasing IL-1 production of monocytes.