title: Induction of PERV antigen in porcine peripheral blood mononuclear cells by human herpesvirus 1.
abstract: BACKGROUND
  Xenotransplantation represents one of alternative candidates for allotransplantation due to the chronic shortage of suitable human tissues; however, many obstacles remain. Expression and release of endogenous retroviral antigens by porcine cells after transplantation may evoke adverse immune responses in human subjects. Here, we examined whether human herpesvirus 1 (HHV-1) could induce the production of porcine endogenous retrovirus (PERV) antigens in porcine peripheral blood mononuclear cells (PBMCs).
  
  
  METHODS
  Porcine PBMCs were infected with HHV-1 and examined for the production of PERV Gag protein and HHV-1 using antigen-capture ELISA and quantitative real-time polymerase chain reaction (PCR), respectively.
  
  
  RESULTS
  HHV-1 infection resulted in a 1.7- to 33.2-fold induction of PERV Gag relative to mock infection controls, compared to a 2.9- to 12.9-fold induction following treatment with PMA. Expression of PERV Gag was detected in porcine PBMCs and PK-15 cells after HHV-1 infection by double immunofluorescence staining of PERV Gag and HHV-1 antigen. The viability of HHV-1-infected porcine PBMCs was significantly lower than that of mock-infected cells. The HHV-1 level in the culture supernatant increased 5.2-fold relative to controls 24-h post-infection, indicative of active replication within these cells; decreased levels of HHV-1 were detected 72-h post-infection.
  
  
  CONCLUSIONS
  These results suggest that HHV-1 may be capable of infecting transplanted porcine cells, resulting in strong direct induction of PERV antigen.
authors.affiliation: Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, Korea; BK21 Plus Biomedical Science Project, Seoul National University College of Medicine, Seoul, Korea; Institute of Endemic Diseases, Seoul National University Medical Research Center, Seoul, Korea.
authors.forename: Jiyeon
authors.initials: J
authors.lastname: Kim
authors.forename: Jung Heon
authors.initials: JH
authors.lastname: Kim
authors.forename: Eung Soo
authors.initials: ES
authors.lastname: Hwang
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000096:biosynthesis*; D002460:Cell Line; D060085:Coinfection / Q000276:immunology / Q000821:virology; D020077:Endogenous Retroviruses / Q000276:immunology* / Q000472:pathogenicity; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D015683:Gene Products, gag / Q000096:biosynthesis / Q000276:immunology; D057809:HEK293 Cells; D018259:Herpesvirus 1, Human / Q000472:pathogenicity*; D064593:Heterografts / Q000821:virology*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology* / Q000821:virology*; D013552:Swine / Q000821:virology*; D013556:Swine, Miniature; D014183:Transplantation, Heterologous / Q000009:adverse effects
chemical_list: D000956:Antigens, Viral; D015683:Gene Products, gag
keywords: Gag; human herpesvirus; porcine cells; porcine endogenous retrovirus; xenotransplantation