Co-Expression and Localization of Angiotensin-Converting Enzyme-2 (ACE2) and the Transmembrane Serine Protease 2 (TMPRSS2) in Paranasal Ciliated Epithelium of Patients with Chronic Rhinosinusitis.

ECRS patients with type 2 inflammation showed decreased ACE2 and TMPRSS2 expressions in their sinus mucosa. ACE2 and TMPRSS2 regulation seems to be positively related to IFN-γ and TNF-α production in CRS patients; ACE2 and TMPRSS2 were co-expressed in the ciliated epithelium of their paranasal mucosa, implicating the paranasal epithelium as a portal for initial infection and transmission.