FBP primarily decreases the protein level of HMGB1 by promoting its lysosomal degradation upon viral infection.

<p>(A) HLCZ01 cells infected with HCV (JFH-1 strain) (MOI, 0.1) for 56 h were treated with FBP for 12 h. Immunoprecipitation of HMGB1 with an anti-HMGB1 antibody and immunoblot analyses with the indicated antibodies were performed. A RIP assay was then performed to test the binding of HCV RNA to HMGB1 The levels of HCV RNA were normalized to the amount of immunoprecipitated HMGB1, as determined by densitometric analysis of western blots (right panels). (B) Huh7.5 cells infected with HCV (JFH-1 strain) (MOI, 0.1) for 24 h were infected with lentivirus-shControl (shCtrl) or lentivirus-shHMGB1 for 24 h and then transfected with full-length or truncated HMGB1 for 36 h. The levels of HMGB1 were analyzed by western blot with the indicated antibody. (C) 293T cells were transfected with siControl (siCtrl) or siHMGB1 for 24 h and then transfected with full-length or truncated HMGB1 for 36 h, followed by HSV-1 infection (MOI, 0.1) for 6 h. The levels of HMGB1 were analyzed by western blot with the indicated antibody. (D) HLCZ01 cells were infected with HCV (JFH-1 strain) at an MOI of 0.1 for 24 h. Subsequently, the cells were infected with lentivirus-shControl or lentivirus-shHMGB1 for 24 h, followed by transfection with full-length or truncated HMGB1 for 36 h. The expression of HMGB1 protein was then analyzed by western blot. The levels of HCV RNA were analyzed by qPCR. Data are presented as the mean ± SEM. NS, not significant, *<i>p</i> < 0.05; **<i>p</i> < 0.01; ***<i>p</i> < 0.001. (D), one-way ANOVA. (A), two-tailed Student’s t test.</p> <p>(DOCX)</p>