title: Inhibition of duck hepatitis B virus replication by mimic peptidesin vitro.
abstract: The aim of the present study was to investigate the inhibitory effect of specific mimic peptides targeting duck hepatitis B virus polymerase (DHBVP) on duck hepatitis B virus (DHBV) replication in primary duck hepatocytes. Phage display technology (PDT) was used to screen for mimic peptides specifically targeting DHBVP and the associated coding sequences were determined using DNA sequencing. The selected mimic peptides were then used to treat primary duck hepatocytes infected with DHBV in vitro. Infected hepatocytes expressing the mimic peptides intracellularly were also prepared. The cells were divided into mimic peptide groups (EXP groups), an entecavir-treated group (positive control) and a negative control group. The medium was changed every 48 h. Following a 10-day incubation, the cell supernatants were collected. DHBV-DNA in the cellular nucleus, cytoplasm and culture supernatant was analyzed by quantitative polymerase chain reaction (qPCR). Eight mimic peptides were selected following three PDT screening rounds for investigation in the DHBV-infected primary duck hepatocytes. The qPCR results showed that following direct treatment with mimic peptide 2 or 7, intracellular expression of mimic peptide 2 or 7, or treatment with entecavir, the DHBV-DNA levels in the culture supernatant and cytoplasm of duck hepatocytes were significantly lower than those in the negative control (P<0.05). The cytoplasmic DHBV-DNA content of the cells treated with mimic peptide 7 was lower than that in the other groups (P<0.05). In addition, the DHBV-DNA content of the nuclear fractions following the intracellular expression of mimic peptide 7 was significantly lower than that in the other groups (P<0.05). Mimic peptides specifically targeting DHBVP, administered directly or expressed intracellularly, can significantly inhibit DHBV replicationin vitro.
authors.affiliation: State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, P.R. China.
authors.forename: Hongyu
authors.initials: H
authors.lastname: Jia
authors.affiliation: Department of Gastroenterology, Shandong Provincial Qianfoshan Hospital, Jinan, Shandong 250013, P.R. China.
authors.forename: Changhong
authors.initials: C
authors.lastname: Liu
authors.affiliation: State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, P.R. China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Yang
authors.affiliation: State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, P.R. China.
authors.forename: Haihong
authors.initials: H
authors.lastname: Zhu
authors.affiliation: State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, P.R. China.
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
authors.affiliation: Department of Medical Oncology, The First People's Hospital of Hangzhou, Hangzhou, Zhejiang 310009, P.R. China.
authors.forename: Jihong
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Molecular Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310038, P.R. China.
authors.forename: Linfu
authors.initials: L
authors.lastname: Zhou
keywords: duck hepatitis B virus; mimic peptides; phage display technology; polymerase; primary duck hepatocytes