FIG. 4.

IL-15-neutralizing antibodies inhibit the HSV-1-mediated increase in the NK activity of PBMC. PBMC were treated with HSV-1 and incubated in the presence of different cytokine neutralizing antibodies. Their NK activities were determined 24 h later. The effects of neutralization of different cytokines on the HSV-1-mediated increase in NK activity of PBMC are shown. A, mock-treated PBMC; B, HSV-treated PBMC; C to H, HSV-infected PBMC incubated in the presence of neutralizing antibodies for cytokines IL-12, TNF-α, IFN-γ, IL-15, control, and IFN-α, respectively. Note that only significant (P < 0.05) inhibition of the HSV-mediated enhancement of NK activity was caused by IL-15-neutralizing antibodies (compare F with B).