ACTIVATED MACROPHAGES AS CYTOTOXIC EFFECTOR CELLS

Abstract

Trypan blue is an inhibitor of nonspecific and specific sarcoma 180 and L1210 leukemia resistance in mice, suggesting that the macrophage is a critical cytotoxic effector cell common to both types of response. Trypan blue may be a useful tool for defining a role of macrophages as cytotoxic effector cells in vivo in other situations. This includes the role of macrophages in the control of hematogenous spread of metastases, destruction of allografts of normal tissue and as possible participant cells in host-mediated destruction of autologous normal tissue, such as occurs in autoimmune diseases. The local nature of nonspecific resistance and the requirement for a population of cytotoxic activated macrophages in the graft site for its expression is additional evidence that macrophages are important in vivo cytotoxic effector cells.