Figure 1

Development of a model system for the efficient expression of HTLV-1 Gag and robust production of VLPs. (A). HTLV-1 Gag expression construct. The HTLV-1 Gag gene was codon-optimized with the insertion of a Kozak consensus sequence (arrow) upstream of the ATG start codon (arrowhead). The EYFP gene was inserted in-frame prior to the Gag gene stop codon. The CMV promoter and 3'-end poly A are indicated. (B). Immunoblot analysis of HTLV-1 Gag. An anti-HTLV-1 p24 monoclonal was used to detect HTLV-1 Gag-EYFP (arrow). Cell culture supernatants were collected from MT-2 cells was used as a positive control. Lane 1-3 are cell culture supernatants from three independent experiments in which pEYFP-N3-HTLV-1 Gag was transiently transfected into 293T cells; lane 4-6 are the cellular lysates. Lane "M", molecular markers. (C). Transmission electron microscopy of VLPs. Left panel, VLPs produced from 293T cells transiently transfected with pEYFP-N3-HTLV-1 Gag; right panel are HTLV-1 particles from MT-2 cells. Scale bar = 200 nm.