Two cytotoxic cells in peritoneal cavity of virus-infected mice: antibody-dependent macrophages and nonspecific killer cells.

Two new types of cell-mediated immune cytolysis of togavirus-infected cells are compared. The peritoneal cavity of mice 2 days after infection contains a nonadherent, non-phagocytic, non-O-bearing, trypsin-resistant, EDTA-sensitive cell displaying broadly specific cytotoxicity for uninfected or virus-infected syngeneic or xenogeneic cell lines. Peritoneal macrophages from normal mice are cytotoxic to infected target cells sensitized with minute amounts of homologous antiviral IgG.