Confirmation of respiratory pDC identity during Klebsiella infection (d5 p.i.) by extended phenotyping and cell sorting. Identity of pDC during Klebsiella pneumonia was confirmed by additional phenotyping of CD11c + 120 g8+ CD11bneg cells for mPDCA-1 and Siglec-H in parallel with isotype controls (A). Functional ability of respiratory pDC from Klebsiella infected animals to produce IFN-alpha was confirmed by cell sorting and CPG ODN stimulation in comparison to control populations (B). Respiratory pDC during Klebsiella pneumonia are CD11bneg 120G8+ Siglec-H+ mPDCA-1+ cells (A, B) and exhibit the capacity to produce large amounts of IFN-α (B). Mean ± SEM; n ≥ 3.