Fig 1.
Biased productive coinfection of cells with GFP and DsRed reporter HIV-1-derived viruses. (A) CD3+ T cells purified from two healthy individuals were mock infected (a and e) and incubated with VSV-G-pseudotyped DsRed reporter virus (b and f) or GFP reporter virus (c and g) or coincubated with both viruses (d and h) and analyzed by flow cytometry (∼2 ng of p24 of each virus). The percentages of single- and double-positive cells are indicated on each dot plot. (B) The percentages of infected cells measured upon separate incubations with the DsRed or the GFP reporter virus were plotted, together with the experimental percentage of coinfection measured when the cells were coincubated with both viruses. The percentages of coinfection in case of stochastic infection were also calculated as the product of the percentages of DsRed-positive cells and GFP-positive cells measured (b or f and c or g) divided by 100. (C) HPB-ALL cells were treated and analyzed as for panel A with ∼2 ng or ∼ 0.1 ng of p24 of HIV-1HXBc2 envelope glycoprotein- or VSV-G-pseudotyepd viruses, respectively. The results are presented as in panel B. (D) HeLa CD4 cells were treated and analyzed as for panel A with ∼20 ng or ∼1 ng of p24 of HIV-1HXBc2 envelope glycoprotein- or VSV-G-pseudotyped viruses, respectively. The results are presented as in panel B. Representative results of experiments performed 3 times in duplicate are shown in panels C and D. Two-proportion z test; ***, z > 3.29, P < 0.001; **, z > 2.57, P < 0.01. The error bars indicate standard deviations.