HLA-DR downregulation in monocytes, but not in mDCs and pDCs in acute CHIKV infection. Monocytes, mDCs, and pDCs were gated as Figure 1. The expression of HLA-DR was analyzed for each cell population. (A) Representative HLA-DR expression profiles on monocytes, mDCs, and pDCs at the indicated days after infection are shown. (B) The percentages of HLA-DR low/negative of monocytes are plotted. HLA-DR, Human Leukocyte Antigen–DR isotype.