FIG. 4.

Binding of HIV-HCV pseudotype particles to T-REx cells expressing DC-SIGN and DC-SIGNR. (A and B) DC-SIGN, DC-SIGNR, and parental T-REx cells were induced with 0.1 μg of doxycycline per ml overnight and incubated with equal volumes of medium containing 1 ng of p24 antigen-normalized virus pseudotypes. Cells were washed and lysed, and p24 antigen content was determined by enzyme-linked immunosorbent assay. The percentage of recovered antigen is indicated. Representative experiments carried out in quadruplicate are shown, with standard deviations indicated. Similar results were obtained in three independent experiments. (C) The binding experiment was carried out as described for A, but prior to addition of virus, T-REx cells were incubated with 20 μg of the indicated MAbs per ml. The results are presented as a percentage of pseudotype binding to control untreated cells. Comparable results were obtained in an independent experiment.