<i>In vivo</i> PD-L1 blockade synergizes with therapeutic vaccination to control WHV replication.

<p>Serum WHV DNA (A) and WHsAg (B) concentrations of different treatment groups are presented at indicated time points. <b>C</b>: control group without any treatment; <b>E</b>: ETV treated only group; <b>ED</b>: ETV in combination with DNA vaccinations; <b>EDA</b>: ETV and DNA vaccination in combination with anti-PDL1 antibody treatment. LOD: lower limit of detection. (C) The kinetics of serum anti-WHs antibodies levels of woodchucks with triple combination treatment is presented. Anti-WHs antibodies level was determined using the following formula: S/N ratio = sample OD value/negative control OD value. Cut-off value of S/N ratio was 2.1. (D) Detection of WHV replication intermediates in liver tissues of differently treated woodchucks. Liver samples were taken 14 weeks after cessation of ETV treatment. Total DNA were extracted from the liver samples and subjected to Southern blotting (upper), PCR (middle), and realtime PCR (lower). RC: relaxed circular DNA, DL: double stranded linear DNA, SS: single stranded DNA. (E) Detection of WHV cccDNA in liver tissues of differently treated woodchucks. Extracted liver DNA samples were digested with Plasmid-Safe ATP-Dependent DNase and subjected cccDNA-specific PCR with primers amplifying the WHV gap-spanning region.