HIV-1 infection is associated with a greater differentiation of classical CD14⁺⁺CD16⁻M-DC8⁻ monocytes into CD16⁺M-DC8⁺ cells in vitro. (A) Correlation of the absolute counts of CD14⁺⁺CD16⁻ classical monocytes with those of nonclassical M-DC8⁺ or M-DC8⁻ CD14⁺CD16⁺⁺ monocytes, and intermediate CD14⁺⁺CD16⁺ monocytes for the 15 viremic patients. (B) FACS-sorted classical CD14⁺⁺CD16⁻ monocytes from a healthy donor were analyzed for CD16 and M-DC8 expression before or after culture for 4 days with GM-CSF and M-CSF. (Bottom panel) Percentages of M-DC8⁺ cells obtained from 3 healthy (open circles) and 2 viremic patients (filled circles). (C) M-DC8 and CD1a expression after 4-day culture of FACS-sorted CD14⁺⁺CD16⁻ classical monocytes from 1 viremic patient (representative of 3 independent experiments) cultured as in panel B the presence or not of IL-4 or IL-10 are shown. (D-F) GM-CSF concentrations were measured (D) in the plasma from 16 healthy donors (HIV⁻, cART⁻), 8 virologically suppressed patients (HIV⁺, cART⁺), or 15 viremic patients (HIV⁺, cART⁻), or (E-F) in culture supernatants from 18-hour LPS-stimulated or unstimulated (E) PBMCs (8 healthy donors [open circles] and 7 viremic patients [filled circles]), and (F) from FACS-sorted CD14⁺⁺CD16⁻ classical (black) or M-DC8⁺ CD14⁺CD16⁺⁺ (gray) monocytes (4 healthy donors [open circles] and 3 viremic patients [filled circles]). When indicated, P values were calculated using the Mann-Whitney test; bars indicate medians.