Influence of chitosan nanofiber scaffold on porcine endogenous retroviral expression and infectivity in pig hepatocytes

Abstract

To investigate the influence of chitosan nanofiber scaffold on the production and infectivity of porcine endogenous retrovirus (PERV) expressed by porcine hepatocytes. Freshly isolated porcine hepatocytes were cultured with or without chitosan nanofiber scaffold (defined as Nano group and Hep group) for 7 d. The daily collection of culture medium was used to detect reverse transcriptase (RT) activity with RT activity assay kits and PERV RNA by reverse transcription-polymerase chain reaction (PCR) and real time PCR with the PERV specific primers. And Western blotting was performed with the lysates of daily retrieved cells to determine the PERV protein gag p30. Besides, the in-vitro infectivity of the supernatant was tested by incubating the human embryo kidney 293 (HEK293) cells. The similar changing trends between two groups were observed in real time PCR, RT activity assay and Western blotting. Two peaks of PERV expression at 10H and Day 2 were found and followed by a regular decline. No significant difference was found between two groups except the significantly high level of PERV RNA at Day 6 and PERV protein at Day 5 in Nano group than that in Hep group. And in the in-vitro infection experiment, no HEK293 cell was infected by the supernatant. Chitosan nanofiber scaffold might prolong the PERV secreting time in pig hepatocytes but would not obviously influence its productive amount and infectivity, so it could be applied in the bioartificial liver without the increased risk of the virus transmission.