Region-specific Innate Antiviral Responses of the Human Epididymis

Viral infections of the epididymis are associated with epididymitis, which damages the epithelium and impairs fertility. We showed previously that innate immune response genes were differentially expressed in the corpus and cauda region of the human epididymis in comparison to the caput. Here we investigate the antiviral defense response mechanisms of human epididymis epithelial (HEE) cells. Toll-like receptor (TLR) 3 and retinoic acid-inducible gene I (RIG-I)- like receptors (RLRs) are enriched in HEE cells from the corpus and cauda region. Furthermore, corpus and cauda HEE cells show an enhanced response to antiviral ligands (poly(I:C) and HSV-60), as shown by increased IFN-β mRNA expression and secretion of IFN-β. We also show that paired box 2 (PAX2), which was implicated in regulating antiviral response pathways is required for basal expression of the DNA sensor, Z-DNA binding protein (ZBP1) and type I interferon, in caput but not in cauda cells. mRNA profiles from Caput HEE cells transfected with negative control (NC) or PAX2 siRNA, in triplicate.