Antibody-Dependent Cell-Mediated Cytotoxicity to Target Cells Infected with Herpes Simplex Viruses

Abstract

Two major mechanisms have been described by which lymphoid cells damage or destroy target cells bearing foreign antigens on their surface. The first of these mechanisms, cell-mediated cytotoxicity (CMC), is important in allograft rejection and tumor immunity (4) and is carried out by sensitized T lymphocytes from specifically immunized hosts. The second mechanism, antibody-dependent cell-mediated cytotoxicity (ADCC), has as yet an undefined role in vivo and is conveyed by the action of mononuclear effector cells on target cells sensitized with antibody to surface membrane antigens (7,15). Unlike CMC, the effector cell in ADCC is found in nonimmunized, as well as immunized hosts. Clearly not a T lymphocyte, in some ADCC systems it appears to be a K cell (3,22), a nonphago-cytic lymphoid cell with an Fc receptor, but no readily detectable surface immunoglobulin. A variety of target cells have been employed in vitro to demonstrate ADCC; these have included xenogeneic (8,14), allogeneic (9,10), and various tumor cells (16), as well as cells passively coated with antigens (2,21). We recently demonstrated for the first time ADCC using viral-infected target cells (17,19).