Human polymorphonuclear leucocytes as mediators of antibody-dependent cellular cytotoxicity to herpes simplex virus-infected cells.

Human polymorphonuclear leucocytes (PML) were able to mediate antibody-dependent cellular cytotoxicity (ADCC) against target cells acutely infected with type 1 Herpes simplex virus. The reaction mediated by PML occurred more slowly and required higher concentrations of immune serum than that mediated by human mononuclear cells (MC). At the same ratio of effector cells to target cells, PML-mediated ADCC was less than MC-mediated ADCC. The observed relationship between the number of effector cells added, and the number of target cells lysed, showed that cytolysis mediated by both PML and MC was consistent with 'one hit' probability predictions. This suggested that target cell death resulted from an interaction with a single effector cell. The calculated frequency of effector cells in PML preparation was similar to that in MC, approximately 3-5%. Preliminary examination of the nature of the effector cells suggested that they did not comprise a morphologically distinct subclass of PML. These experiments demonstrate a possible new role for PML in host defence against viral infections.