EBV infection elicits type I IFN production in PBMCs in a pDC-dependent manner. Total PBMCs were exposed to EBV, CpG C, Poly I:C, or R848 at the indicated concentrations, and culture supernatants were collected after 18 to 24 hours and analyzed for cytokine production according to enzyme-linked immunosorbent assay. IFN-α (A) and IL-12p40 (B) content was measured. (C) PBMCs were inoculated with wild-type EBV (wt), EBNA3A-deficient EBV (3aKO), or EBNA3C-deficient EBV (3cKO), and IFN-α production was measured. MOI 0.005, n = 5; MOI 0.05, n = 7; and MOI 0.25, n = 9. (D) Total PBMCs were compared with pDC-depleted PBMCs. MOI 0.005, n = 2; MOI 0.05, n = 4; and MOI 0.25, n = 2. Paired Student t tests were used for all graphs.