MFI values for antibodies to MHC class I, MHC class II, and CD83 on IEA-positive and -negative CD11c⁺ DCs. Mean fluorescence intensity (MFI) of antibodies to MHC class I (HLA-ABC), MHC class II (HLA-DR), and CD83 on virally exposed cells staining positively and negatively for IEA were calculated in the percentages of MFIs of mock-infected cells, as measured by flow cytometry (A-B). Results are shown as mean ± SEM. (A) n = 3 for HLA-ABC, n = 8 for HLA-DR (P < .05 and P < .01 for IEA-positive and -negative cells, respectively), and n = 8 for CD83 (P < .005 and P < .05 for IEA-positive and -negative cells, respectively). (B) n = 3. Numbers of experiments correspond to numbers of separate donors. IEA-positive and -negative cells showed higher expression of all 3 markers compared with mock (= 100) regardless of absence (-BI) or presence (+BI) of IFN-blocking.