Inhibition of HBV gene expression and replication by stably expressed interferon-alpha1 via adeno-associated viral vectors.
BACKGROUND
Interferon-alpha2 (IFNalpha2) is routinely used for anti-hepatitis B virus (HBV) treatment. However, the therapeutic efficiency is unsatisfactory, particularly in East Asia. Such inefficiency might be a result of the short half-life, relatively low local concentration and strong side-effects of interferons. Frequent and repeated injection is also a big burden for patients. In the present study, a single dose of vector-delivered IFNalpha1 was tested for its anti-HBV effects.


METHODS
Adeno-associated viral vector (AAV-IFNalpha1) was generated to deliver the IFNalpha1 gene into hepatocytes. IFNalpha1, hepatitis B surface (HBsAg) and e (HBeAg) antigens were measured by enzyme-linked immunosorbent assay and/or western blotting. The level of viral DNA was measured by quantitative real-time polymerase chain reaction.


RESULTS
AAV-IFNalpha1 effectively transduced HBV-producing cells (HepAD38) and mouse hepatocytes, where IFNalpha1 was expressed in a stable manner. Both intracellular and extracellular HBsAg and HBeAg were significantly reduced in vitro. In the HBV-producing mice, the concentration of IFNalpha1 in the liver was eight-fold higher than that in plasma. Compared with control groups, HBeAg/HBsAg antigen levels were reduced by more than ten-fold from day 1-5, and dropped to an undetectable level on day 9 in the AAV-IFNalpha1 group. Concurrently, the level of viral DNA decreased over 30-fold for several weeks.


CONCLUSIONS
A single dose administration of AAV-IFNalpha1 viral vector displayed prolonged transgene expression and superior antiviral effects both in vitro and in vivo. Therefore, the use of AAV-IFNalpha1 might be a potential alternative strategy for anti-HBV therapy.
Li
Zhi
Z
Department of Microbiology, The University of Hong Kong, Hong Kong, China.
Yao
Hong
H
Ma
Yan
Y
Dong
Qingming
Q
Chen
Yangchao
Y
Peng
Ying
Y
Zheng
Bo-jian
BJ
Huang
Jian-dong
JD
Chan
Chu-yan
CY
Lin
Marie C
MC
Sung
Joseph J
JJ
Yuen
Kwok Yun
KY
Kung
Hsiang-fu
HF
He
Ming-Liang
ML
D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D000229:Dependovirus; D004797:Enzyme-Linked Immunosorbent Assay; D015967:Gene Expression Regulation, Viral / Q000276:immunology*; D005822:Genetic Vectors / Q000235:genetics; D006509:Hepatitis B / Q000628:therapy*; D006511:Hepatitis B Antigens / Q000378:metabolism; D006515:Hepatitis B virus / Q000276:immunology* / Q000378:metabolism; D007167:Immunotherapy / Q000379:methods*; D016898:Interferon-alpha / Q000378:metabolism*; D051379:Mice; D014779:Virus Replication / Q000276:immunology*
D006511:Hepatitis B Antigens; D016898:Interferon-alpha