In Vitro Tumor Growth Inhibition by Syngeneic Lymphocytes and/or Macrophages

Abstract

We (3) have recently confirmed the hypothesis by Prehn (13) that the normal immune response to neoplasia might have a dual role. This hypothesis suggests that during the early development of cancer or with weakly immunogenic, transplantable tumors, the cell-mediated response might directly stimulate rather than inhibit tumor growth. Our studies (3) reported the results of the interaction of normal, sensitized and concanavalin A-stimulated syngeneic, allogeneic, and/or xenogeneic lymphocytes with the B16 melanoma, C57BL/6 and/or A mouse embryo cells in an in vitro colony inhibition-stimulation system. Specifically sensitized lymphocytes at ratios up to 1000:1 repeatedly and significantly enhanced the growth of the target cells. At higher lymphocyte ratios, target cell inhibition occurred.