Fig. 3

Veritrop assay detecting the function of the HIV-1 envelope proteins in the context of SHIV_KB9 backbone. A schematic of the Veritrop cell-to-cell fusion assay is shown in (a). The target cell, U87.CD4.CCR5 was transfected with pDM128fLuc, a vector where expression of firefly luciferase gene is dependent on both HIV-1 Rev and Tat produced by the effector cell [34]. The effector cell is transfected with pREC_nfl_SHIV_KB9env_B vectors, which express entire SHIV proteome and produce virus particles that lack the proper SHIV genomic RNA for de novo replication [20]. Levels of cell fusion (via relative light units from Luciferase activity) are shown for the effector cells transfected with pREC_nfl_SHIV _KB9env_B vectors (b)