title: Purification of infectious human herpesvirus 6A virions and association of host cell proteins.
abstract: BACKGROUND
  Viruses that are incorporating host cell proteins might trigger autoimmune diseases. It is therefore of interest to identify possible host proteins associated with viruses, especially for enveloped viruses that have been suggested to play a role in autoimmune diseases, like human herpesvirus 6A (HHV-6A) in multiple sclerosis (MS).
  
  
  RESULTS
  We have established a method for rapid and morphology preserving purification of HHV-6A virions, which in combination with parallel analyses with background control material released from mock-infected cells facilitates qualitative and quantitative investigations of the protein content of HHV-6A virions. In our iodixanol gradient purified preparation, we detected high levels of viral DNA by real-time PCR and viral proteins by metabolic labelling, silver staining and western blots. In contrast, the background level of cellular contamination was low in the purified samples as demonstrated by the silver staining and metabolic labelling analyses. Western blot analyses showed that the cellular complement protein CD46, the receptor for HHV-6A, is associated with the purified and infectious virions. Also, the cellular proteins clathrin, ezrin and Tsg101 are associated with intact HHV-6A virions.
  
  
  CONCLUSIONS
  Cellular proteins are associated with HHV-6A virions. The relevance of the association in disease and especially in autoimmunity will be further investigated.
authors.affiliation: Department of Biosciences and Nutrition at Novum, Karolinska Institutet, Huddinge, Sweden. maria.hammarstedt@med.lu.se
authors.forename: Maria
authors.initials: M
authors.lastname: Hammarstedt
authors.forename: Jenny
authors.initials: J
authors.lastname: Ahlqvist
authors.forename: Steven
authors.initials: S
authors.lastname: Jacobson
authors.forename: Henrik
authors.initials: H
authors.lastname: Garoff
authors.forename: Anna
authors.initials: A
authors.lastname: Fogdell-Hahn
mesh_terms: D015153:Blotting, Western; D002460:Cell Line; D004279:DNA, Viral / Q000032:analysis / Q000302:isolation & purification; D015654:Herpesvirus 6, Human / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D051916:Membrane Cofactor Protein / Q000302:isolation & purification / Q000378:metabolism*; D009103:Multiple Sclerosis / Q000821:virology*; D014771:Virion / Q000302:isolation & purification*
chemical_list: C497857:CD46 protein, human; D004279:DNA, Viral; D051916:Membrane Cofactor Protein