FIG 1.

HIV-1 replication in MDM induces the downmodulation of mannose receptor 1 (MRC1) and PU.1. (A) Terminally differentiated human monocyte-derived macrophages (MDMs) were infected in triplicate with the R5-tropic HIV-1 isolate AD8 (WT). Virus replication was monitored for 16 days by measuring the virus-associated reverse transcriptase (RT) assay. Uninfected MDMs were cultured in parallel (mock). On days 9 and 16 (marked by red arrows), parts of the cells were removed and processed for immunoblotting. Mean and error bars representing standard error of the mean (SEM) calculated from triplicate infections are shown. (B) Immunoblotting was performed on days 9 and 16 on whole-cell extracts using antibodies to MRC1, HIV-1 (CA, p55), and tubulin (tub). Molecular mass markers are on the left. Proteins are identified on the right. (C) MDMs were infected with concentrated, VSVg-pseudotyped stocks of AD8 WT or AD8 variants lacking expression of individual viral proteins as indicated at the top. Cells were harvested 9 days postinfection and processed for immunoblot analysis using antibodies to MRC1, PU.1, HIV (CA), and tubulin (tub). A representative blot of two independent experiments is shown. A nonspecific band below the MRC1 band (marked by a star in panels B and C) is seen in some experiments. Its intensity varies in a donor-dependent manner. (D and E) MRC- and PU.1-specific bands from panel C were quantified by image analysis and expressed relative to signals observed in the uninfected (mock) cells. Mean and error bars representing SEM calculated from two independent infections are shown.