CD14(LOW)CD16(HIGH) - A CYTOKINE-PRODUCING MONOCYTE SUBSET WHICH EXPANDS DURING HUMAN-IMMUNODEFICIENCY-VIRUS INFECTION

Infection with the human immunodeficiency virus HIV-1 is associated wi th the expansion of a CD14(low)CD16(high) monocyte subset in periphera l blood. This subset, which represents a minor subpopulation of monocy tes in healthy individuals, increases during HIV infection and, in pat ients with BIDS, may represent up to 40% of the total circulating mono cyte cell population. The CD14(low)CD16(high) circulating monocytes co -express MAX.1, p150,95 and HLA-DR which are typical of tissue macroph age markers. These cells also express higher levels of intracellular i nterleukin (IL)-1 alpha and tumor necrosis factor (TNF)-alpha than the CD14(high)CD16(low) monocyte population from the same patients. The C D14(low)CD16(high) cells also express low levels of CD35, CD11a and CD 4 in common with normal monocytes. When cultured in vitro, monocytes f rom HIV-seropositive individuals differentiated within a few hours int o an elongated fibroblastoid shape characteristic of migratory cells. Our results suggest that the expansion of the CD14(low)CD16(high) mono cyte subset, which produce high amounts of TNF-alpha acid IL-1 alpha, may participate in the immune dysfunction observed during HIV infectio n.