Impact of NLRX1 gene mutation on hepatocytes in inhibiting HBV infection

Objective To explore the potential regulation role of the NLRX1 gene mutation (NLRX1 p.Arg707Cys) on hepatocytes in inhibiting hepatitis B virus (HBV) infection. Methods The Huh7 cell line with stable over-expression of NTCP (Huh7-NTCP) was constructed using a lentiviral vector (LV003). Plasmid transfection was used to construct Huh7-NTCP of wild type (WT) NLRX1 and mutant type (MT) NLRX1. Impact of WT and MT on HBV infectivity were tested on HBV infected Huh7-NTCP. HBsAg and HBcAg were analyzed by immunohistochemistry and western blot. HBV DNA and HBV cccDNA were analyzed by qPCR. The expression levels of IFN-α, IFN-β, IL-6 were detected by qPCR. Results Cell model experiments confirmed that HBsAg, HBcAg, HBV cccDNA and HBV DNA in both WT and MT NLRX1 groups increased significantly comparing to control group, while the expressions of above criteria in MT NLRX1 groups were significantly lower than those of WT NLRX1 groups. The expressions of final products that were induced by MAVS-RLRs signal path, including IFN-α, IFN-β and IL-6 were consistent with the above results. Conclusions NLRX1 is a regulatory factor that inhibits the anti-HBV ability of hepatocytes, and its encoding gene mutation NLRX1 p.Arg707Cys weakens the regulatory function. Key words: Immune regulator; NLRX1; NLRX1 p. Arg707Cys; Hepatitis B virus