Cell culture, reagents, and antibodies.

The human hepatocellular carcinoma cell line Huh7 and the human embryonic kidney cell line HEK293T were cultured in Dulbecco’s modified Eagle’s medium (DMEM) supplemented with 10% fetal bovine serum (FBS), 100 U/ml penicillin, and 100 μg/ml streptomycin. Concerning the production of HDV, Huh7 cells were cultured in Williams’ medium E (WME) supplemented with 10% fetal bovine serum, 100 mg/ml gentamicin, and GlutaMAX (Gibco). The human hepatoblastoma cell lines HepG2 and HepG2.2.15 were cultured in WME supplemented with 10% FBS, 100 mg/ml gentamicin, and GlutaMAX. Rapamycin, bafilomycin A1, and Benzonase were purchased from Sigma-Aldrich. The concentration of rapamycin used in each experiment was adjusted depending on the exposure time to minimize toxicity. Protein A/G-agarose plus was purchased from Santa Cruz. DNase was purchased from Qiagen. Rabbit polyclonal anti-LC3B (catalog number L7543) and anti-ATG5 (catalog number A0856) antibodies and mouse monoclonal anti-β-actin (catalog number A5441) and anti-Flag (catalog number F1804) (for immunofluorescence) antibodies were purchased from Sigma-Aldrich. The monoclonal antibody anti-SQSTM1 (catalog number H00008878) was purchased from Abnova. The rabbit polyclonal antibodies anti-ATG7 (catalog number D12B11) and anti-Flag (catalog number 2368) (for Western blotting) were purchased from Cell Signaling. Human serum against HDV was described previously (41). The anti-preS1 (catalog number Sc-57761) monoclonal antibody was purchased from Santa Cruz.