HCs are potential targets for HIV-1 infection but express low levels of the co-stimulatory signal CD80. The cell surface expression of molecules involved in (A) HIV-1 entry and (B) activation were analyzed on HCs and MDMs. Fluorescence intensity was measured in cells incubated with antibodies against the pattern recognition receptor (CD14), the co-stimulatory markers (CD80-PE and CD86-APC), MHC II marker (HLA-DR-PE) and HIV-1 receptors (CD4-APC, CCR5-PerCp-Cy5.5, CXCR4-PE-Cy7, and DC-SIGN-PE). (A) Phenotypic markers are represented as a percentage of expression in purified populations of HCs and MDMs. Results are presented as a mean percentage (±SE) of the total population, which are positive for the marker. Data shown are representative of three independent experiments from different donors (* p < 0.05, **p < 0.01).