Tumor infiltrating cells in human cancer. On the possible role of CD16+ macrophages in antitumor cytotoxicity.

Abstract

We have demonstrated the presence of a large number of macrophages in the cellular infiltrates of several types of tumors. The largest numbers of CD16+ macrophages were found in renal cancer, melanoma, and colonic-carcinoma. These are the tumors that are most susceptible to immunotherapy with lymphokine activated killer cells, suggesting that these CD16+ macrophages may be involved in antitumor cytotoxicity. Furthermore, these findings suggest that new strategies of immunotherapy aimed at the use of macrophages present in many tumors could be developed.