Epigallocatechin-3-gallate suppresses Hepatitis B virus replication through activating AMPK/TFEB pathway to promote autophagic degradation of viral core protein (Accepted)

Epigallocatechin-3-gallate (EGCG), a major polyphenol in green tea, can inhibit various viruses including HBV. However, the role of EGCG in HBV replication and its underlying mechanisms remain inadequately elucidated. Here, we investigated the effects of EGCG on HBV replication and its role in autophagy-related mechanisms in two HBV cell models. Our results demonstrated that EGCG effectively reduced the levels of secreted HBsAg and HBV DNA, as well as intracellular HBV DNARIs, encapsidated pgRNA and core protein (HBc) levels, while HBV mRNAs and pgRNA levels were not affected. EGCG enhanced autophagic flux, as indicated by increased autophagosome formation and accelerated degradation of the autophagic cargo receptor p62 and LC3-Ⅱ. The enhanced autophagy promoted HBc degradation. Pharmacological inhibition of autophagy using 3-methyladenine, chloroquine, or bafilomycin A1 effectively prevented the inhibitory effect of EGCG on HBV. Specifically, chloroquine or bafilomycin A1 combined with EGCG significantly enhanced HBV production by blocking autophagic degradation and promoting autophagosomes accumulation, akin to the effect of the autophagy inducer rapamycin in facilitating HBV replication. Mechanistically, EGCG activated AMPK/TFEB signaling to enhance lysosomal biogenesis and ATP production, thereby promoting the autophagic degradation. Pharmacological or genetic inhibition of AMPK clearly diminished the transcriptional activity of TFEB, attenuated the lysosomal biogenesis, ATP production and autophagic degradation induced by EGCG, upregulated HBc and ultimately promoted HBV production. Conversely, pharmacological activation of AMPK yielded opposite results. Our findings reveal a novel mechanism by which EGCG inhibits HBV. EGCG promotes autophagic degradation of viral core protein through activating the AMPK/TFEB signaling pathway.