Mean fluorescence intensity of CD1a, MHC class I, MHC class II, CD86, and CD40 protein expression on VZV-infected DCs. VZV-infected DCs were harvested at day 2 postinfection and dual-stained with VZV immune polyclonal human serum and monoclonal antibodies specific for CD1a, MHC class I (MHC I), MHC class II (MHC II), CD86, or CD40. The mean fluorescence intensity (MFI) values of VZV− cells (white boxes) and VZV+ cell populations (black boxes) are shown.