title: Early reverse transcription is essential for productive foamy virus infection.
abstract: BACKGROUND
  Although viral RNA constitutes the majority of nucleic acids packaged in virions, a late occurring step of reverse transcription leads to the presence of infectious viral cDNA in foamy virus particles. This peculiarity distinguishes them from the rest of the retroviral family.
  
  
  RESULTS
  To evaluate the respective contribution of these viral nucleic acids in the replication of foamy viruses, their fate was studied by real-time PCR and RT-PCR early after infection, in the presence or in the absence of AZT. We found that an early reverse transcription step, which occurs during the first hours post-entry, is absolutely required for productive infection. Remarkably, sensitivity to AZT can be counteracted by increasing the multiplicity of infection (moi). We also show that 2-LTR circular viral DNA, which appears as soon as four hours post-infection, is transcriptionally competent.
  
  
  CONCLUSIONS
  Taken together, our data demonstrate that an early reverse transcription process, which takes place soon after viral entry, is indispensable for infectivity of FVs at low moi, when the amount of DNA-containing particles is not sufficient to lead to a productive infection. This study demonstrates a key role of the packaged viral RNA in the foamy virus infection, suggesting that the replication of this virus can be achieved by involving either viral DNA or RNA genome, depending on the condition of infection.
authors.affiliation: CNRS UMR7212, Inserm U944, Université Paris Diderot, Institut Universitaire d'Hématologie, Paris, France.
authors.forename: Alessia
authors.initials: A
authors.lastname: Zamborlini
authors.forename: Noémie
authors.initials: N
authors.lastname: Renault
authors.forename: Ali
authors.initials: A
authors.lastname: Saïb
authors.forename: Olivier
authors.initials: O
authors.lastname: Delelis
mesh_terms: D000998:Antiviral Agents / Q000494:pharmacology; D004279:DNA, Viral / Q000235:genetics; D008826:Microbial Sensitivity Tests; D012192:Retroviridae Infections / Q000235:genetics* / Q000821:virology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016092:Spumavirus / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity*; D014158:Transcription, Genetic; D014771:Virion / Q000235:genetics; D015215:Zidovudine / Q000494:pharmacology
chemical_list: D000998:Antiviral Agents; D004279:DNA, Viral; D015215:Zidovudine