title: An orphan viral TNF receptor superfamily member identified in lymphocystis disease virus.
abstract: BACKGROUND
  Lymphocystis disease virus (LCDV) is a large icosahedral dsDNA-containing virus of the Lymphocystivirus genus within the Iridoviridae family that can cause disease in more than 140 marine and freshwater fish species. While several isolates have been charcaterized and classified into distinct genotypes the complete genomic sequence is currently only available from two species, the LCDV-1, isolated from flounder (Platichtys flesus) in Europe and the LCDV-C, isolated from Japanese cultured flounder (Paralichthys olivaceus) in China. Analysis of the genome of LCDV-C showed it to encode a protein named LDVICp016 with similarities to the Tumour necrosis factor receptor (TNFR) superfamily with immunomodulatory potential.
  
  
  RESULTS
  We have expressed and purified the recombinant protein LDVICp016 and screened for potential interaction partners using surface plasmon resonance. Commercially available human and mouse members of the TNF superfamily (TNFSF), along with a representative set of fish-derived TNFSF were tested.We have found the LDVICp016 protein to be secreted and we have identified a second viral TNFR encoded by ORF 095 of the same virus. None of the 42 tested proteins were found to interact with LDVICp016.
  
  
  CONCLUSIONS
  We show that LDVICp016 is a secreted protein belonging to the TNF receptor family that may be part of a larger gene family in Lymphocystiviruses. While the ligand of this protein remains unknown, possibly due to the species specific nature of this interaction, further investigations into the potential role of this protein in the blockade of immune responses in its fish host are required.
authors.affiliation: Centro de Biología Molecular ¨Severo Ochoa¨, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Cantoblanco, Madrid 28049, Spain.
authors.forename: Sergio M
authors.initials: SM
authors.lastname: Pontejo
authors.forename: Carolina
authors.initials: C
authors.lastname: Sánchez
authors.forename: Rocío
authors.initials: R
authors.lastname: Martín
authors.forename: Victoriano
authors.initials: V
authors.lastname: Mulero
authors.forename: Antonio
authors.initials: A
authors.lastname: Alcami
authors.forename: Alí
authors.initials: A
authors.lastname: Alejo
mesh_terms: D000818:Animals; D005399:Fishes; D006801:Humans; D007497:Iridoviridae / Q000235:genetics*; D051379:Mice; D011485:Protein Binding; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics* / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism*
chemical_list: D018124:Receptors, Tumor Necrosis Factor; D011994:Recombinant Proteins; D014764:Viral Proteins