Both infectious IAV and HI IAV induce maturation and cytokine secretion in mDCs and pDCs in a pH-dependent manner.

<p>mDCs (<b>A</b>) or pDCs (<b>B</b>) were exposed to infectious IAV or HI IAV in the absence or presence of NH₄Cl for 24 hr. The frequency of IAV+ DCs and their CD86 expression was determined. Dot plots show live DCs and numbers in each quadrant depict the frequency of positive DCs. One representative donor of eight is shown. (<b>C</b>) The surface expression of CD86, CD40, MHCI (HLA-ABC) and MHCII (HLA-DR) on mDCs (blue) and pDCs (red) was determined after 24 hr of exposure to infectious IAV, HI IAV or TLR7/8L in the absence or presence of NH₄Cl. Bar graphs show MFI±SD (n = 3). The levels of secreted IFNα from supernatants of pDCs (<b>D</b>) or mDCs (<b>E</b>) after 24 hr were determined by ELISA. The graphs show mean±SD (n = 9).