Abstract Background Influenza A virus (IAV) remains a serious global health threat requiring host-directed therapeutics due to rising antiviral resistance. We previously identified the pro-apoptotic protein Bcl-2-interacting killer (BIK) as a proviral factor; Bik-deficient mice are protected from severe IAV outcomes. Furthermore, a genetic variation (rs738276) in BIK, which influences its expression, correlates with altered viral replication and human influenza severity. We found that IAV stabilizes BIK by inhibiting its proteasome-mediated degradation. We hypothesized that IAV targets specific E3 ubiquitin ligase responsible for BIK ubiquitination to promote replication. This study identifies the BIK-binding E3 ubiquitin ligase targeted by IAV and evaluates its therapeutic potential against IAV infection in vitro, in vivo, and ex vivo. Methods C57BL/6 wild-type (WT) and Bik knockout (Bik-/-) mice were used for in vivo studies. We employed mass spectrometry (MS), Western blot, co-immunoprecipitation, and ubiquitination assays to identify BIK-regulating E3 ligase and assess protein interactions. The proposed regulatory axis was confirmed using loss- and gain-of-function experiments in cell models. The therapeutic potential of ARIH2 was tested ex vivo using human precision-cut lung slices (hPCLS) transduced with AAV-ARIH2 and subsequently infected with IAV. In vivo, ARIH2 was delivered intranasally via AAV6.2 to mice prior to IAV infection. Therapeutic impact was evaluated by assessing viral load, lung inflammation (H R01AI148180)
Mebratu et al. (Fri,) studied this question.