HSV-2–infected macaque DCs induce lower T-cell proliferation. Immature macaque and human (A) moDCs were exposed or not to 5 pfu per cell HSV-2 (live versus UV treated) and recultured for 4 hours before being cultured with 2 × 10⁵ human T cells in 96 well flat-bottomed trays (triplicates per condition) at the ratios indicated (normalized to viable DC numbers). After 5 days of culture, the plates were pulsed with 1 μCi (2.7 × 10^–17 Bq) per well of ³H-TdR, and the amount of ³H-TdR incorporated (counts per minute [cpm]) in the last 8 hours of culture was measured. (A) The mean cpm (± SEM) is shown for one macaque and human representative experiment comparing DCs treated with medium (Med), UV-treated HSV-2 (UV), or infectious HSV-2 (HSV). The cpm values for DCs or T cells cultured alone were typically below 400 cpm. (B) The fold reduction (mean ± SEM, from 8 to 9 experiments comparing medium versus HSV-2–infected DCs and an additional 2 experiments comparing medium, UV-HSV, and infectious HSV-treated DCs) in the T-cell proliferation induced by HSV-2–infected macaque DCs at different DC–T cell ratios is indicated. The fold reduction was calculated by dividing the mean cpm of ³H-TdR uptake in cocultures of T cells with medium-treated DCs by the mean cpm of ³H-TdR incorporated by T cells cocultured with live or UV HSV-2–treated DCs. The values for the medium-treated DC–T cell cocultures are 1. (C) Medium-treated and HSV-2–infected macaque DCs were kept unfixed or an aliquot fixed with 1% PFA and used to stimulate human T cells at a ratio of 1 DC per 40 T cells. The fold reduction (mean ± SEM, 3 experiments using DCs from 3 different donors) in the T-cell proliferation induced by HSV-2–infected DCs was calculated (as in Figure 5B) for the unfixed and fixed DCs run in parallel.