Figure 4.

Endosomal acidification is required for pDC activation by HSV-2. Wild-type bone marrow cells were pretreated with either media alone, chloroquine (A and B), or with bafilomycin A1 (C and D) at the indicated concentrations. Either stimulatory CpG oligonucleotide (5 μg/ml), UV-HSV-2 (5 × 10⁶ PFU/ml), or R848 (1 μg/ml) were added to the pretreated cells and incubated for 18 h at 37°C. Supernatants were collected and IFN-α (A and C) or IL-12p40 (B and D) levels were measured using ELISA.