[Study on anti-HBV effects of genetically engineered replication-defective hepatitis B virus expressing dominant negative mutants of core protein].
BACKGROUND
To explore the possibility of using HBV as a gene delivery vector, and to test the anti-HBV effects by intracellular expression of dominant negative mutants of core protein.


METHODS
Two kinds of full length mutant HBV genome, which express Core-partial P and Core-S fusion protein, were transfected into HepG 2.2.15 cell lines. Positive clones were selected and mixed in respective groups with hygromycin in the culture medium. HBsAg and HBeAg, which exist in the culture medium, were tested by ELISA and intracellular HBc related HBV DNA was examined by dot blot hybridization. The existence of recombinant HBV virion in the culture medium was examined by PCR.


RESULTS
The mean inhibitory rates of HBsAg were 2.74+/-3.83%, 40.08+/-2.05% (P less than 0.01) and 52.94+/-1.93% (P less than 0.01) in group 2.2.15-pMEP4, 2.2.15-CP and 2.2.15-CS, respectively. The mean inhibitory rates of HBeAg were 4.46+/-4.25%, 52.86+/-1.32% (P less than 0.01) and 41.60+/-1.65% (P less than 0.01), respectively. The inhibitory rates of HBc related HBV DNA were 15.3%, 82.0% and 67.2%, respectively. Recombinant HBV virion was detectable in the culture medium of only group 2.2.15-CP.


CONCLUSIONS
Dominant negative mutants of core protein can efficiently suppress wt-HBV replication and the expressions of HBV antigens. With the help of wild-type HBV, the recombinant HBV genome can form and secret HBV like particles, which provides evidence that the antiviral gene will be hepatotropic expression and the antiviral effects will be amplified.
Sun
Dian-xing
DX
Department of Liver Diseases, Bethune International Peace Hospital, Shijiazhuang 050082, China.
Liu
Feng-jun
FJ
Hu
Da-rong
DR
Wu
Guang-hui
GH
Hu
Xue-ling
XL
Han
Ju-qiang
JQ
Li
Juan
J
D045744:Cell Line, Tumor; D005818:Genetic Engineering; D015316:Genetic Therapy; D005822:Genetic Vectors; D016679:Genome, Viral; D006512:Hepatitis B Core Antigens / Q000096:biosynthesis / Q000502:physiology*; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D017354:Point Mutation; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000502:physiology*; D014779:Virus Replication
D006512:Hepatitis B Core Antigens; D011993:Recombinant Fusion Proteins