Figure 1. Schematic representation of HIV-1 Env-mediated cell-cell fusion assay. HEK293T cell was co-transfected with two recombinant plasmids, pcHXB3Env and pcDNA3.1Tat101-FLAG, in order to express HIV-1 Env proteins on the cell surface and produce regulatory Tatprotein, respectively.
HeLa T4+ cell was transfected with pTruLTRGFP to harbor LTRdriven copGFP. Cell fusion facilitated content mixing that allowed Tat binding to the HIV-1 LTR, resulting in LTR-driven copGFP expression in fused cell.
The production of copGFP was then quantified by determining of green fluorescent signal. In the presence of fusion
inhibitor, cell-cell fusion was inhibited which displayed as low-background of copGFP
intensity.