Targeted inhibition of HBV gene expression by single-chain antibody mediated small interfering RNA delivery.
RNA interference is highly effective at inhibiting HBV gene expression and replication. However, before small interfering RNA (siRNA) can be used in the clinic, it is essential to develop a system to target their delivery. Antibody-mediated delivery is a novel approach for targeting siRNA to appropriate cells. In this report, we asked whether this siRNA delivery strategy would be effective against HBV. Of 5 candidates, a specific siRNA that effectively inhibited HBV gene expression and replication was determined. Two fusion proteins, s-tP and sCkappa-tP, were constructed to contain a single chain of the human variable fragment, scFv, against hepatitis B surface antigen (HBsAg), a truncated protamine (tP), and in the case of sCkappa-tP, a constant region of the kappa chain (Ckappa). S-tP and sCkappa-tP were developed to provide targeted delivery of the siRNA, siRNA expressing cassettes (SEC), and siRNA-producing plasmids. Fluorescein isothiocyanate-siRNA, fluorescein isothiocyanate-SEC, and plasmid DNA were specifically delivered into HBsAg-positive cells using the sCkappa-tP fusion protein, and effectively inhibited HBV gene expression and replication. HBV gene expression was also inhibited by siRNA or siRNA-producing plasmids in HBV transgenic mice.


CONCLUSIONS
Our results describe a potential method for the targeted delivery of siRNA or siRNA-producing plasmids against HBV, using anti-HBsAg fusion proteins.
Wen
Wei-Hong
WH
State Key Laboratory of Cancer Biology, Department of Immunology, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
Liu
Jia-Yun
JY
Qin
Wei-Jun
WJ
Zhao
Jing
J
Wang
Tao
T
Jia
Lin-Tao
LT
Meng
Yan-Ling
YL
Gao
Hui
H
Xue
Cai-Fang
CF
Jin
Bo-Quan
BQ
Yao
Li-Bo
LB
Chen
Si-Yi
SY
Yang
An-Gang
AG
D000818:Animals; D006528:Carcinoma, Hepatocellular; D045744:Cell Line, Tumor; D015967:Gene Expression Regulation, Viral / Q000276:immunology; D006511:Hepatitis B Antigens / Q000494:pharmacology*; D006515:Hepatitis B virus / Q000235:genetics* / Q000276:immunology; D006801:Humans; D008113:Liver Neoplasms; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D010957:Plasmids; D016133:Polymerase Chain Reaction; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics* / Q000276:immunology*
D006511:Hepatitis B Antigens; D034741:RNA, Small Interfering