CyTOF analysis of monocyte populations in mock, ZIKV, or DENV2 ex vivo-exposed PBMCs. (A) Scheme of the subsets and differentiation stages of circulating monocytes. (B) Frequencies of monocyte subsets in the monocyte compartment (HLADR+ CD1c− CD141lo CD11c+). (C) Quantification of selected activation markers and cytokines in classical, nonclassical, and intermediate monocytes upon infection with ZIKV or DENV2. (D) Comparison of selected activation markers and cytokines among the different monocyte subtypes at 24 and 48 hpi. Data from cells from 5 donors are shown. Means ± SEM are indicated. Stars without bars in panels B, C, and D indicate statistically significant differences with mock treatment. ***, P < 0.001; **, P < 0.01; *, P < 0.05.