The factors influencing the transfer of porcine endogenous retroviruses across the membrane in bioartificial livers / 中华肝胆外科杂志

ABSTRACT

ObjectiveTo identify the factors influencing the transfer of porcine endogenous retroviruses across the membrane of a new bioartificial liver (BAL),which is a necessary caution to consider for BALs carrying porcine hepatocytes.MethodsA novel porcine BAL composed of two circuits was constructed using a plasma filter with membrane pore size of 500 nm and a plasma component separator with membrane pore sizes 10 nm,20 nm,30 nm,and 35 nm.Co-cultured cells of porcine hepatocytes and mesenchymal stem cells or single porcine hepatocytes were incubated in the bioreactors.The BAL was continuously worked for 72 hours during which the supernatant was collected from the internal and external circuits every 12 hours.PERV RNA,reverse transcriptase (RT) activity,and in vitro infectivity from the supernatant were detected.ResultsIn the plasma filter group,the PERV RNAlevels were the same in both circuits,suggesting little to no effect of the plasma filter on the PERV RNA's crossing.With plasma component separators,PERV RNA was found in the external circuits at different times without positive RT activity and HEK293 cell infection,but its level was reduced significantly.The larger the membrane pore size was,the earlier and the more RNA was detected.ConclusionsThe membrane pore size,the treatment time and the viral level in the internal circuit are contributing factors influencing the transfer of PERV RNA across the membrane in a BAL.