title: Suppression of hepatitis B virus antigen production and replication by wild-type HBV dependently replicating HBV shRNA vectors in vitro and in vivo.
abstract: Chronic infection with hepatitis B virus (HBV), a small DNA virus that replicates by reverse transcription of a pregenomic (pg) RNA precursor, greatly increases the risk for terminal liver disease. RNA interference (RNAi) based therapy approaches have shown potential to overcome the limited efficacy of current treatments. However, synthetic siRNAs as well as small hairpin (sh) RNAs expressed from non-integrating vectors require repeated applications; integrating vectors suffer from safety concerns. We pursue a new concept by which HBV itself is engineered into a conditionally replicating, wild-type HBV dependent anti-HBV shRNA vector. Beyond sharing HBV's hepatocyte tropism, such a vector would be self-renewing, but only as long as wild-type HBV is present. Here, we realized several important aspects of this concept. We identified two distinct regions in the 3.2 kb HBV genome which tolerate replacement by shRNA expression cassettes without compromising reverse transcription when complemented in vitro by HBV helper constructs or by wild-type HBV; a representative HBV shRNA vector was infectious in cell culture. The vector-encoded shRNAs were active, including on HBV as target. A dual anti-HBV shRNA vector delivered into HBV transgenic mice, which are not susceptible to HBV infection, by a chimeric adenovirus-HBV shuttle reduced serum hepatitis B surface antigen (HBsAg) up to ∼4-fold, and virus particles up to ∼20-fold. Importantly, a fraction of the circulating particles contained vector-derived DNA, indicating successful complementation in vivo. These data encourage further investigations to prove antiviral efficacy and the predicted self-limiting vector spread in a small animal HBV infection model.
authors: Chinese PLA Medical School, Chinese PLA General Hospital, 100853, Beijing, PR China; The Liver Disease Diagnosis and Treatment Center of PLA, Bethune International Peace Hospital, Shijiazhuang, 050082, PR China.
authors: Baosheng
authors: B
authors: Li
authors: The Liver Disease Diagnosis and Treatment Center of PLA, Bethune International Peace Hospital, Shijiazhuang, 050082, PR China; Troop 66220 of PLA, Xingtai, Hebei Province, 054000, PR China.
authors: Shuo
authors: S
authors: Sun
authors: The Liver Disease Diagnosis and Treatment Center of PLA, Bethune International Peace Hospital, Shijiazhuang, 050082, PR China; The Fourth Department of the Fifth Hospital, Shijiazhuang City, 050017, PR China.
authors: Minran
authors: M
authors: Li
authors: The Liver Disease Diagnosis and Treatment Center of PLA, Bethune International Peace Hospital, Shijiazhuang, 050082, PR China.
authors: Xin
authors: X
authors: Cheng
authors: The Liver Disease Diagnosis and Treatment Center of PLA, Bethune International Peace Hospital, Shijiazhuang, 050082, PR China.
authors: Haijun
authors: H
authors: Li
authors: The Liver Disease Diagnosis and Treatment Center of PLA, Bethune International Peace Hospital, Shijiazhuang, 050082, PR China.
authors: Fubiao
authors: F
authors: Kang
authors: The Liver Disease Diagnosis and Treatment Center of PLA, Bethune International Peace Hospital, Shijiazhuang, 050082, PR China.
authors: Jiwen
authors: J
authors: Kang
authors: Internal Medicine II/Molecular Biology, University Hospital Freiburg, D-79106, Freiburg, Germany.
authors: Katharina
authors: K
authors: Dörnbrack
authors: Internal Medicine II/Molecular Biology, University Hospital Freiburg, D-79106, Freiburg, Germany. Electronic address: nassal2@ukl.uni-freiburg.de.
authors: Michael
authors: M
authors: Nassal
authors: The Liver Disease Diagnosis and Treatment Center of PLA, Bethune International Peace Hospital, Shijiazhuang, 050082, PR China. Electronic address: sundianxing@hotmail.com.
authors: Dianxing
authors: D
authors: Sun
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D030801:Animals, Genetically Modified; D004261:DNA Replication; D004279:DNA, Viral / Q000235:genetics; D005816:Genetic Complementation Test; D005822:Genetic Vectors; D016679:Genome, Viral; D006514:Hepatitis B Surface Antigens / Q000097:blood / Q000235:genetics*; D006515:Hepatitis B virus / Q000235:genetics* / Q000502:physiology*; D051379:Mice; D008822:Mice, Transgenic; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics / Q000502:physiology*; D012367:RNA, Viral / Q000235:genetics; D014779:Virus Replication
chemical_list: D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens; D034741:RNA, Small Interfering; D012367:RNA, Viral
keywords: Chronic hepatitis B; HBV transgenic mice; HBV vector; Hepatitis B virus; RNAi; shRNA delivery