Fig. 8

IFN released by R848-treated monocytes protects bystander cells from HIV-1 infection. a Monocytes from three healthy donors (one bar per donor) were incubated for 24 h with supernatant harvested from untreated (mock supe, grey) or R848-treated monocytes (R848 supe, red). Untreated (−) and cells pretreated with 1 µM R848 (R848, blue) served as controls. The cells were then infected with Vpx-containing HIV1 luciferase reporter virus (HIV1 X+) or uninfected (mock). Luciferase activity was measured 72 h post-infection. b, c Monocytes from 3 healthy donors treated with R848. The drug was either removed after 2 h (2 h, red) or left on the cells for 24 h (24 h, blue). The treated monocytes were placed in the lower compartment of a transwell plate (b) and PBMC were placed in the upper compartment (c). 24 h after R848 treatment, the cells in both compartments were infected with Vpx-containing HIV-1 luciferase reporter virus (HIV1 X+). (d) Activated CD4+ T cells from 2 donors were treated for 24 h with supernatant from untreated (mock supe), R848-treated monocytes (R848 supe, red) or with 1 μM R848 (R848, blue) and then infected with HIV-1 GFP reporter virus, or uninfected (mock). After 72 h, the number of GFP+ cells was determined by flow cytometry. e Monocytes from 3 healthy donors were treated for 24 h with supernatant from untreated (mock supe, grey) or R848-treated (R848 supe) monocytes (monocyte supe, red) or activated CD4+ T cells (CD4+ T cell supe, orange) and then infected with Vpx-containing HIV1 luciferase reporter virus. Controls without supernatant pretreatment (−) or treated with R848 (blue) were included. f Monocytes from 3 healthy donors were incubated with increasing amounts of supernatant from R848-treated monocytes (R848 supe, red) in the absence (no AB, solid bars) or presence of IFN blocking antibody cocktail (αIFN AB, dotted bars). The cells were infected 24 h post-treatment with Vpx-containing HIV-1 luciferase reporter virus