Fig. 1

Effect of HIV-1 infection on TNT formation in U87 cells. a U87.CD4.CCR5 cells were left uninfected or infected with JRFL (input: 100 ng/ml p24 Gag), cultured for 2 days, and analyzed for F-actin (green) and α-tubulin (red) by immunofluorescence. Nuclei were also stained with DAPI (blue). Lower and higher magnification images are shown in upper and lower panels, respectively. In the lower panels, three different fields for each group are shown. Scale bar: 50 µm. dpi, days postinfection. b Cells were prepared as in (a) Three different fields were randomly selected, and the number of TNTs per field (top), and the length (middle) and thickness (bottom) of TNTs were quantified. *p < 0.05. dpi, days postinfection. c U87.CD4.CCR5 cells were infected with JRFL (input: 100 ng/ml p24 Gag), cultured for 2 days, and analyzed for Env (grey) and Gag (red). Nuclei were also stained with DAPI (blue). Yellow arrowheads indicate TNTs. Scale bar: 50 µm. dpi, days postinfection. d U87.CD4.CCR5 cells were left uninfected, or infected with either the wild-type (WT) or Nef-deficient (ΔNef) JRFL virus (input: 100 ng/ml p24 Gag), cultured for 2 days, and analyzed for F-actin by immunofluorescence. Nuclei were also stained with DAPI (blue). Three different fields were randomly selected, and the number of TNTs per field (upper) and the number of nuclei per cell (lower) were quantified. *p < 0.05