Differential HIV infection of monocytes, DCs, and macrophages. Peripheral-blood monocytes were processed immediately or cultured as described (“Materials and methods, Monocute isolation and differentiation to macrophages and dendritic cells”) to generate immature DCs and differentiated macrophages. (A) By flow-cytometry analysis using antibodies specific to CD14 and DC-SIGN, the 3 populations were phenotypically distinct. (B) Cultures of monocytes, DCs, and macrophages were incubated with HIV-1BaL for 90 minutes, washed, and incubated for 12 to 14 days. Media aliquots were removed every third day for p24 ELISA and replaced with fresh DMEM containing antibiotics and serum. Representative of 4 experiments (day 14 after infection; *P < .001, #P < .05) (SEM). (C) Transmission electron microscopy (EM) of macrophage infected with HIV-1 for 10 days, demonstrating intracellular budding and accumulation of virions (original magnification, × 20,000) using a Zeiss EM10 Microscope (LEO Electron Microscopy, Oberkochen, Germany). (D) Dual-color flow-cytometry analysis of CD4 and CCR5 expression and single-color annexin II staining on monocytes, macrophages, and DCs.
