Fig 1. eSF enhance HIV infection of CD4+ T cells.

(A) Schematic of infection of T cells in the absence or presence of eSF co-culture. eSF are grown until confluency, at which time PBMCs are added at a ratio of 10 PBMC: 1 eSF. HIV is then added and infection rates are assessed 3 d later by flow cytometry. (B) Unstimulated, PHA-activated, or PHA/IL2-activated PBMCs were infected with an HIV reporter virus encoding GFP (NLENG1I, derived from CXCR4-tropic NL4-3) in the absence or presence of eSF, and monitored 3 d later for levels of productive infection. Left: Representative flow cytometric plots. Right: Results of experimental triplicate measurements. Results are gated on live, singlet CD3+CD8- cells. **p<0.01, ***p<0.001 (by 2-tailed t test). Representative of data from >10 experiments each with different eSF donors. (C) Purified CD4+ T cells were infected with NLENG1I in the absence or presence of eSF. Top: PBMC-derived CD4+ T cells were isolated to >97% purity. Bottom: These cells were left unstimulated or activated with PHA/IL2, infected with NLENG1I in the absence or presence of eSF, and monitored for infection levels 3 d later by flow cytometry. Results are gated on live, singlet CD3+CD8- cells. **p<0.01 (by 2-tailed t test). Representative of data from 3 experiments each with different eSF donors. (D) CD3/CD28-activated PBMCs were infected with NLENG1I in the absence or presence of eSF and monitored 3 d later for infection. Top: Representative flow cytometric plots. Bottom: Results of experimental triplicate measurements. Results are gated on live, singlet CD3+CD8- cells. ****p<0.0001 (by 2-tailed t test). Representative of data from 3 experiments each with different eSF donors. (E) Fold-enhancement of NLENG1I infection of PBMCs when comparing infection rates in the presence versus absence of eSF. Shown are the results summarizing 15 experiments each using a different eSF donor (left, mean: 36-fold), and 15 experiments each using a different PBMC donor (right, mean: 28-fold).