Viral gene expression in SARS-CoV–infected human adult immature DCs by quantitative RT-PCR. Both negative (A) and positive strands (B) of SARS-CoV Replicase 1b mRNA were detected in SASR-CoV–infected adult immature DCs at 3 hours, 9 hours, 24 hours, day 3, and day 6 after infection (MOI = 1). Similar pattern of decreased viral gene expression was detected for the negative and positive strands in all 3 cases.