FIG 2.

HBV replication neither activates nor inhibits cGAS-STING signaling pathway. (A to F) Each of the indicated cell lines was cultured in the presence or absence of TET for 3 and 5 days. The levels of HBV pgRNA (A), cytoplasmic HBV core DNA (B), IFN-β mRNA (D), IL-29 mRNA (E), and CXCL10 mRNA (F) were determined by qPCR assays and are presented as the fold change compared to that in HepAD38 cells cultured in the presence of TET. Means and standard deviations are shown (n = 4). Proper induction of HBV DNA replication upon TET removal was further confirmed by Southern blotting hybridization with a [³²P]UTP-labeled riboprobe specific for minus-strand of HBV DNA (C). Relaxed circular DNA (rcDNA), single-stranded DNA (ssDNA), and 3.2- and 2.0-kb DNA size markers are indicated. (G to I) HepAD38/cGAS-STING cells were cultured in the presence (open bar) or absence (filled bar) of TET for 5 days. The cells were then reseeded at a density of 5 × 10⁵ cells per well of a 12-well plate and mock transfected or transfected with dsDNA90 using Lipofectamine-3000 at 12 h after seeding. The levels of HBV core DNA in pretransfected cells (G), as well as IL-29 mRNA (H) and CXCL10 mRNA (I), at 12 h posttransfection were determined by qPCR assays and are presented as the fold change compared to that in HepAD38/cGAS-STING cells cultured in the presence of TET. Means and standard deviations are shown (n = 6).