title: Factors influencing the transfer of porcine endogenous retroviruses across the membrane in bioartificial livers.
abstract: OBJECTIVE
  to investigate the factors influencing the transfer of porcine endogenous retroviruses (PERVs) across the membrane in a new bioartificial liver (BAL).
  
  
  METHODS
  A new BAL containing 2 circuits was constructed using plasma component separators with membrane pore sizes of 10 nm, 20 nm, 30 nm, and 35 nm, or a plasma filter with a membrane pore size of 500 nm. Cocultured cells of porcine hepatocytes and mesenchymal stem cells or single porcine hepatocytes were incubated in the bioreactors, and the BAL worked for 72 hours, with supernatant samples in internal and external circuits collected every 12 hours. PERV RNA, reverse transcriptase (RT) activity, and in vitro infectivity of the supernatant were detected.
  
  
  RESULTS
  With the plasma filters, the results of PERV detection were the same in both circuits. With plasma component separators, PERV RNA was found in the external circuits, but no positive RT activity or HEK293 cell infection was found. The time at which the PERV RNA was first detected varied with the pore size of membrane; the larger the membrane pore size was, the earlier the RNA was detected. The PERV RNA level in the external circuits was reduced significantly compared with that in the internal circuits at any detecting time.
  
  
  CONCLUSIONS
  The plasma component separators with membrane pore size =35 nm could significantly reduce the passage of infectious PERVs. And the membrane pore size, the treatment duration, and the viral level in the internal circuit were potential factors influencing the transfer of PERVs across the membrane in a BAL. In addition, a low risk of PERV transmission from porcine hepatocytes to human cells was found.
authors.affiliation: Department of Hepatobiliary Surgery, Affiliated DrumTower Hospital of Nanjing University Medical School, Nanjing - PR China.
authors.forename: Xiao-Lei
authors.initials: XL
authors.lastname: Shi
authors.forename: Bing
authors.initials: B
authors.lastname: Han
authors.forename: Jia-Jun
authors.initials: JJ
authors.lastname: Tan
authors.forename: Xianwen
authors.initials: X
authors.lastname: Yuan
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jiang-Qiang
authors.initials: JQ
authors.lastname: Xiao
authors.forename: Zhong-Ze
authors.initials: ZZ
authors.lastname: Gu
authors.forename: Yi-Tao
authors.initials: YT
authors.lastname: Ding
mesh_terms: D000818:Animals; D019149:Bioreactors; D018920:Coculture Techniques; D020077:Endogenous Retroviruses / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D057809:HEK293 Cells; D022781:Hepatocytes / Q000821:virology*; D006801:Humans; D019164:Liver, Artificial / Q000009:adverse effects; D008567:Membranes, Artificial; D059630:Mesenchymal Stem Cells / Q000821:virology*; D016062:Porosity; D012367:RNA, Viral / Q000378:metabolism; D012192:Retroviridae Infections / Q000635:transmission* / Q000821:virology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018570:Risk Assessment; D013552:Swine; D013997:Time Factors; D014774:Virulence
chemical_list: D008567:Membranes, Artificial; D012367:RNA, Viral