CD16+ monocyte subset preferentially harbors HIV-1 and is expanded in pregnant Malawian women with Plasmodium falciparum malaria and HIV-1 infection.

In a cross-sectional study, monocyte subsets in placental, cord, and maternal peripheral blood from pregnant Malawian women with human immunodeficiency virus (HIV)-1 infection and/or malaria were analyzed. HIV-uninfected Malawian women had higher baseline proportions of CD16(+) monocytes than those reported for healthy adults in developed countries. Malaria was associated with an increase in the proportion of CD16(+) monocytes that was significant in women coinfected with HIV-1. CD16(+) monocytes expressed higher CCR5 levels than did CD14(hi)/CD16(-) monocytes and were significantly more likely to harbor HIV-1. These data suggest a role for CD16(+) monocytes in the pathogenesis of maternal malaria and HIV-1 infections.