Signaling by a cytosolic receptor should be abrogated if inhibition of endosomal acidification in turn prevented rotavirus entry into the cytosol. However, the persistence and even increase of NSP2 expression following treatment with concanamycin A indicates that pDC entry by rotavirus is conserved under conditions that alter endosomal pH and decrease the pDC IFN response (Figure 8 ). (B, C) pDCs from multiple donors were exposed to RRV and the percent of IFNa + (B) (n = 26) or IFNb + (C) (n = 4) pDCs negative, dim or bright for NSP2 were determined. *:p = 0.0286, ***: p#0.0006; Wilcoxon signed rank test. Donors with fewer than 0.5% of pDCs staining positive for NSP2 were excluded from this analysis. (D) Representative histograms of IRF7 phosphorylation in NSP2 bright (red), NSP2 dim (blue), and NSP2 -(green) pDCs 6 hours post RRV or mock (gray) stimulus. (E, F) Percent increase in pIRF7 (E) or total IRF7 (F) MFI by indicated pDC populations relative to mock treated pDCs from multiple donors (n = 6), 6 hours post RRV inoculation. *: p = 0.0313; Wilcoxon signed rank test. doi:10.1371/journal.ppat.1000931.g005