Fig 2. The decrease in T cell transduction efficiency by SIVMAC is not explained by differences in reporter gene expression.
(A) CRFK cells (left panel) and Jurkat T cells (right panel) were transduced with VSV G-pseudotyped, single-cycle, two-part HIV-1NL4-3GFP or SIVMAC239-GFP vectors, as in Fig 1 . Virus stocks were normalized by reverse transcriptase activity prior to transduction. 48 hrs after transduction, cells were visualized by phase contrast and fluorescence microscopy. Shown are representative fields for each condition at 100x magnification. Fluorescence intensity of individual T cells transduced with SIVMAC239-GFP is at least as strong as that in cells transduced with HIV-1NL4-3GFP. (B) VSV G-pseudotyped, HIV-1NL4-3 (black squares) and SIVMAC239 (white circles) three-part vectors were generated by plasmid transfection of 293T cells. In each case, the viral genomic RNA was designed to transduce an identical SFFV-GFP reporter gene. Vector stocks were normalized by titer on CRFK cells, and then used to challenge Jurkat T cells. 48 hrs post vector challenge, the percentage GFP-expressing cells was determined by FACS. Data is plotted as percent GFP+ (infected) cells (Y axis) versus CRFK infectious units (IU) x 1,000 (X axis).