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.