Figure 5

Preferential LFA-1-independent transfer of HIV particles to CD45RO+ cells during T cell-T cell synapses. Panel A. MOLT cells chronically infected with NL4-3 (grey bars) and BaL (dark bars) viruses or left uninfected (white bars) were cultured with purified primary CD4 T cells. After 2 h of coculture, cells were stained with anti-CD45RO and anti-HIV p24 antibodies. Analysis of HIV transfer in the absence (left graph) or presence (right graph) of the RM3A5 blocking mAb against ICAM-1 was performed after gating separately CD45RO and CD45RA CD4 T cells. Panel B shows the expression of HIV Env (right) and ICAM-1 (left) in 293T transfected cells (empty peaks), solid peaks correspond to negative controls of staining. Panel C shows HIV transfer from 293T cells transfected with an Env defective and an NL4-3 Env plasmids, to CD45RO- (RO-) and CD45RO+ (RO+) target cells in the absence (light bars) or presence (grey bars) of ICAM-1 expression. HIV transmission was again measured in the absence (left graph) or the presence (right graph) of the blocking RM3A5 antibody against ICAM-1. Values are Mean ± SD of 3 experiments performed with CD4 T cells from 3 different donors. Asterisks denote significant differences in HIV transmission to the CD45RA CD4 T subset compared to CD45RO cells (Panel A and C). Significant differences intrasubsets induced by ICAM-1 expression are also indicated by asterisks in panel C, while ns denotes no statistical significance.