FIG. 6.

The syndecan-Fc hybrid molecule inhibits both HIV-1 transmigration and HIV-1 transfer from DC to T cells. (A) Pseudotyped NL4.3ΔEnv/gp160 R5 Env virus (25 ng of p24) or Gp160-deficient NL4.3ΔEnv virus (25 ng of p24) was added to the apical surface of PGEC. Syndecan-1-Fc or control Fc (5 μg/ml) was added to PGEC 30 min before the virus was added. Amounts of transcytosed viruses in the basal chamber were quantified by p24 ELISA. Results are expressed as a percentage of p24 of the original inoculum. The points are median values, and error bars represent standard errors of triplicates. (B) DC (100,000 cells) were incubated for 2 h at 37°C with wild-type NL4.3-eGFP (X4 virus) and NL4.3-BaL-eGFP (R5 virus) viruses or with the pseudotyped NL4.3ΔEnv-eGFP/gp160 X4 Env virus (25 ng of p24). Syndecan-1-Fc or control Fc (5 μg/ml) was added 2 h later. DC were washed 2 h after the Fc proteins were added, Jurkat T cells (100,000 cells) were added for 3 days, and the percentage of infected Jurkat T cells was analyzed. The percentage of HIV-infected Jurkat T cells (gated by using an anti-CD3 antibody) in DC-T-cell coculture was analyzed by GFP expression on day 5. Error bars represent standard errors of duplicates. (C) The experiment is as described in the legend of Fig. 2B.