Mikio Yamawaki

Antitumor activity of nocardia cell wall skeleton preparations in transplantable tumors in syngeneic mice and patients with malignant pleurisy.

SummaryThe antitumor activity of the cell wall skeleton preparations of four species of Nocardia, N. brasiliensis strain 146, N. coeliaca strain 122, N. polychromogenes strain 6, and N. rubra, which showed potent adjuvant activity on the induction of cell-mediated cytotoxicity in allogeneic mice, was examined with the aid of EL-4 leukemia, melanoma B16, and MH-134 hepatoma in syngeneic mice. Preliminary clinical trials were performed and the results suggest that the cell wall skeleton of N. rubra, upon intrapleural injection, may be useful as an immunotherapeutic agent for patients with malignant pleurisy. The chemical properties of these cell wall skeleton preparations are described.

Macrophage dependency of T-lymphocyte mitogenesis by Nocardia rubra cell-wall skeleton.

The mitogenic activity of the cell‐wall skeleton (CWS) of Nocardia rubra on purified splenic T‐cells (thymus‐derived lymphocytes) was investigated. N. rubra CWS showed remarkable mitogenic activity on normal spleen cells of C57BL/6J mice at concentrations ranging from 10 to 100 μg per milliliter of culture medium, while, on purified splenic T‐cells, N. rubra CWS did not act as a mitogen at any concentration. However, mitogenic activity of N. rubra CWS on T‐cells was restored if purified splenic T‐cells were reconstituted with X‐irradiated peritoneal exudate cells (macrophages). The above results suggest the necessity of macrophages for T‐lymphocyte activation by N. rubra CWS as well as PHA‐P or Con A.