Lysis of herpes simplex virus-infected targets. II. Nature of the effector cells.

Peripheral blood lymphocytes (PBL) from patients with herpes simplex virus (HSV)-1 recurrences in the cornea only (Group I) exhibited reduced lysis of HSV-1-infected targets compared to PBL from patients with oral-facial and corneal HSV recurrences (Group II). The cytotoxic lymphocytes appeared to belong to a subpopulation of natural killer (NK-HSV) cells. Monoclonal antibodies to human lymphocyte differentiation antigens were used to define the surface phenotype of the NK-HSV cells. Most of the NK-HSV activity was mediated by lymphocytes expressing the surface markers Leu-7+ (HNK-1), OKT3+ (pan T), OKM1+ (myeloid and NK), Leu-2- (cytotoxic/suppressor T cell), and Leu-8- (regulatory T cell). In contrast, lysis of K562 cells (NK-K562) was mediated by lymphocytes bearing the surface phenotype Leu-7+, OKT3-, OKM1+, Leu-2+/-, and Leu-8-. The low level of NK-HSV activity in PBL from Group I donors appeared to be due to active suppression by suppressor T lymphocytes. Depletion of Leu-2+ cells from PBL of Group I donors resulted in significant augmentation of NK-HSV activity. Similar treatment of PBL from Group II donors either had no effect or slightly diminished the NK-HSV activity.