ERVW-1 and infection: Consistent with productive infection, the DENV envelope protein was expressed in 31 ± 5.5% imDCs; secreted virus was detected in the cell culture supernatant by qRT-PCR at 1.4 × 108 ± 1.7 × 107 genome copies/ml and secreted infectious virus by plaque assay at a titre of 2.4 × 105 ± 3.3 × 104 pfu/ml.