Effector cell involved in cell-mediated cytotoxicity to cells infected with herpes simplex virus type 1

Experiments were performed to analyze the characteristics of the effector cells involved in cell-mediated killing of herpes-infected fibroblasts. Effector cells were fractionated according to adherence and phagocytic properties, and lymphocytes were depleted of T-cells, and EA- and EAC- (antibody-coated bovine erythrocytes and bovine erythrocytes coated with rabbit anti-bovine antibodies and C5-deficient mouse serum, respectively) rosette-forming cells by differential centrifugation. Column passage was used as an alternative to depletion of B-cells and F(c)-receptor-positive cells. Antibody-dependent, cell-mediated cytotoxicity was found to be associated with nonphagocytic cells carrying low-avidity F(c) receptors. Some of these had surface immunoglobulin; others lacked both B- and T-cell markers. Low levels of killing were found without addition of anti-herpes antibody to the test system, and this killing seemed to depend on cells belonging to the same subpopulation as the antibody-dependent effector cells.