Sensing of cell-associated HTLV by plasmacytoid dendritic cells is regulated by dense β-galactoside glycosylation
Fig 2
The HTLV-1 receptor Glut-1 is involved in pDC IFN-I production triggered by the sensing of HTLV-1 infected cells, but not Neuropilin-1/BDCA-4.
A. Assessment by FACS of the surface expression of the HTLV-1 receptors Glut-1 (revealed with Glut-1.RBD.GFP and controlled with unstained cells), NRP-1/BDCA-4 (revealed with mAb and controlled with IgG isotype) and HSPG (revealed with mAb and controlled with IgG isotype). (representative of 3 independent experiments). B-D. Impact of Glut-1 binding competitor (RBD, 5 μl/105 cells) or NRP-1/BDCA-4 binding competitor (VEGF165, 100 ng/mL) on IFN-I activity in SNs of pDCs co-cultured with HTLV-1-infected cells (C91-PL) (mean ± SD; 5 independent experiments) (B), viral binding was determined by flow cytometry after Env gp46 detection on pDCs surface (mean ± SD, 3 independent experiments) (C), and infectivity transmission levels (mean ± SD; 3 independent experiments) (D), determined as in Fig 1. The results in (C) and (D) are expressed as percentages relative to untreated co-cultures. Asterisks indicate statistically significant differences calculated using ANOVA followed by Sidak’s multiple comparison test: * p> 0.05, **** p< 0.0001; ns: non significant. E. Viral binding as determined by flow cytometry after p19gag detection on Jurkat target cells upon exposure to HTLV-1 cell-free viruses or upon co-culture with HTLV-1 infected cells in the presence or not of NRP-1/BDCA-4 binding competitor (VEGF165, 80 ng/mL). Jurkat cells were differentiated from HTLV-1 infected cells based on their size (see S2C Fig). The results are expressed as percentage relative to untreated conditions (mean ± SD; 2–3 independent experiments). Asterisks indicate statistically significant differences calculated using ANOVA followed by Sidak’s multiple comparison test: *** p<0.001; ns = non significant.