Infection of human pDCs and cDCs with SARS-CoV. Primary pDCs or cDCs were isolated from peripheral blood of healthy donors and infected with either SARS-CoV (moi = 1) or Newcastle disease virus (NDV) as positive control (moi = 5), or were left uninfected (mock). (A) IFN-α in culture supernatants was determined at the indicated time points. Results represent pooled data (means ± SD) using pDCs and cDCs from 4 healthy donors. Statistical analysis was performed using Student t test (*P < .05). (B-C) Expression of IFN-β, ISG56, MxA, SARS-CoV N protein, and γ-actin mRNAs in (B) cDCs and (C) pDCs was determined by RT-PCR. One representative result of 4 individual experiments is shown.