title: Further Evidence that Human Endogenous Retrovirus K102 is a Replication Competent Foamy Virus that may Antagonize HIV-1 Replication.
abstract: OBJECTIVE
  The goals of the research were to determine if a foamy effect on macrophages was due to human endogenous retrovirus K102 (HERV-K102) replication, and to further address its potential significance in HIV-1 infection.
  
  
  METHODS
  An RT-PCR HERV-K HML-2 pol method was used to screen the unknown HERV, and isolated bands were sent for sequencing. Confirmation of RNA expression was performed by a real time quantitative PCR (qPCR) pol ddCt method. Rabbit antibodies to Env peptides were used to assess expression by immunohistology and processing of Env by western blots. A qPCR pol ddCt method to ascertain genomic copy number was performed on genomic DNA isolated from plasma comparing HIV-1 exposed seronegative (HESN) commercial sex workers (CSW) to normal controls and contrasted with HIV-1 patients.
  
  
  RESULTS
  HERV-K102 expression, particle production and replication were associated with foamy macrophage generation in the cultures of cord blood mononuclear cells under permissive conditions. A five-fold increased HERV-K102 pol genomic copy number was found in the HESN cohort over normal which was not found in HIV-1 positive patients (p=0.0005).
  
  
  CONCLUSIONS
  This work extends the evidence that HERV-K102 has foamy virus attributes, is replication competent, and is capable of high replication rate in vivo and in vitro. This may be the first characterization of a replication-competent, foamy-like virus of humans. High particle production inferred by increased integration in the HESN cohort over HIV-1 patients raises the issue of the clinical importance of HERV-K102 particle production as an early protective innate immune response against HIV-1 replication.
authors.affiliation: Bloodborne Pathogens Division, Blood Zoonotics Unit, Public Health Agency of Canada, Ottawa, Ontario Canada; Department of Pathology and Laboratory Medicine, The University of Ottawa, Ottawa, Ontario Canada.
authors.forename: Marian P
authors.initials: MP
authors.lastname: Laderoute
authors.affiliation: Bloodborne Pathogens Division, Blood Zoonotics Unit, Public Health Agency of Canada, Ottawa, Ontario Canada.
authors.forename: Louise J
authors.initials: LJ
authors.lastname: Larocque
authors.affiliation: Division of Hematopathology and Transfusion Medicine, The Ottawa Hospital, Ottawa, Ontario Canada; Department of Pathology and Laboratory Medicine, The University of Ottawa, Ottawa, Ontario Canada.
authors.forename: Antonio
authors.initials: A
authors.lastname: Giulivi
authors.affiliation: The Advanced Medical Research Institute of Canada, Sudbury, Ontario Canada; Department of Pathology and Laboratory Medicine, The University of Ottawa, Ottawa, Ontario Canada.
authors.forename: Francisco
authors.initials: F
authors.lastname: Diaz-Mitoma
keywords: DNA genomes; HERV-K102; HESN; HIV-1; HML-2 type 1; foamy macrophages.; foamy virus; innate immunity