title: The potential role of APOBEC3G in limiting replication of hepatitis B virus.
abstract: OBJECTIVE
  Recent findings introduced APOBEC3G (A3G) as a host factor that blocks viral replication. It induces G to A hypermutations in viral DNA at the step of reverse transcription and in response to interferon. This study aimed to investigate the expression of liver A3G protein in association with both replication of hepatitis B virus (HBV) and frequency of G to A mutations in BCP (basal core promoter)-PC (pre-core) region.
  
  
  METHODS
  Fifty-one liver biopsies of naïve chronic hepatitis B (CHB) patients enrolled for the expression of A3G were done by immunohistochemistry (IHC) standard method. The presence of HBV DNA and sequences of BCP-PC region at the time of liver biopsy was investigated in all patients.
  
  
  RESULTS
  Among 34 patients with detectable HBV DNA, 31 carried 1-5 G to A mutations in the BCP-PC region. IHC results showed that the expression level of A3G in CHB patients' liver was very low. Of all patients, A3G is expressed in three undetectable HBV DNA subjects and a patient with 2.24×10(4) copies ml(-1) of HBV DNA. G to A mutated residues were indicated at positions 1727, 1757 and 1896 of the HBV genome of this patient.
  
  
  CONCLUSIONS
  This study indicates that despite very low levels of both A3G in liver and the number of positive subjects, A3G has a potential role to restrict the in vivo replication of HBV.
authors: Digestive Disease Research Centre, Tehran University of Medical Sciences, Tehran, Iran. ashraf@ams.ac.ir
authors: Ashraf
authors: A
authors: Mohamadkhani
authors: Akbar
authors: A
authors: Pourdadash
authors: Sirous
authors: S
authors: Tayebi
authors: Arezoo
authors: A
authors: Estakhri
authors: Habibollah
authors: H
authors: Nazem
authors: Masoud
authors: M
authors: Sotoudeh
authors: Hossein
authors: H
authors: Poustchi
mesh_terms: D000071480:APOBEC-3G Deaminase; D000293:Adolescent; D000328:Adult; D001706:Biopsy; D003564:Cytidine Deaminase / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004279:DNA, Viral; D005260:Female; D015870:Gene Expression; D006515:Hepatitis B virus / Q000235:genetics / Q000502:physiology*; D019694:Hepatitis B, Chronic / Q000378:metabolism* / Q000473:pathology / Q000821:virology; D006801:Humans; D007150:Immunohistochemistry; D008099:Liver / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011401:Promoter Regions, Genetic / Q000235:genetics; D014779:Virus Replication / Q000235:genetics / Q000502:physiology*; D055815:Young Adult
chemical_list: D004279:DNA, Viral; D000071480:APOBEC-3G Deaminase; C464924:APOBEC3G protein, human; D003564:Cytidine Deaminase