title: Cell culture propagation and biochemical analysis of the Ljungan virus prototype strain.
abstract: Ljungan virus (LV) is proposed as a potentially important rodent harbored viral human pathogen. Little is known about the biophysical nature of the virus and despite being molecularly characterized, progress in epidemiological and basic biological studies of LV has been hampered by the lack of a robust and reliable cell culture propagation system. Here we report the first description of an efficient lytic multi-cycle cell culture propagation of the LV prototype strain (87-012). Biophysical analysis of gradient purified LV virions generated by this system identified mature infectious virions to possess a sedimentation coefficient of 160S and in agreement with previous molecular prediction, polyprotein analysis suggests that the native virion is composed of only three major structural proteins. The nucleotide composition of the complete genome of the LV cell culture adapted virus was determined and compared to that of the parental prototype LV. Numerous mutations were observed scattered throughout the viral genome and particularly in VP1. The development of this cell culture system for LV should open new avenues in the study of LV biology, structure, pathogenesis, and prevalence of natural infection in the wider community.
authors.affiliation: Department of Chemistry and Biomedical Sciences, University of Kalmar, S-391 82 Kalmar, Sweden.
authors.forename: E Susanne
authors.initials: ES
authors.lastname: Johansson
authors.forename: Jens-Ola
authors.initials: JO
authors.lastname: Ekström
authors.forename: Darren R
authors.initials: DR
authors.lastname: Shafren
authors.forename: Gun
authors.initials: G
authors.lastname: Frisk
authors.forename: Timo
authors.initials: T
authors.lastname: Hyypiä
authors.forename: Kjell
authors.initials: K
authors.lastname: Edman
authors.forename: A Michael
authors.initials: AM
authors.lastname: Lindberg
mesh_terms: D000818:Animals; D016466:CHO Cells; D036022:Capsid Proteins / Q000737:chemistry / Q000378:metabolism; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D006224:Cricetinae; D016679:Genome, Viral; D006801:Humans; D008253:Macaca mulatta; D051379:Mice; D009154:Mutation; D041681:NIH 3T3 Cells; D010849:Picornaviridae / Q000235:genetics / Q000254:growth & development*; D014709:Vero Cells; D014771:Virion / Q000737:chemistry / Q000378:metabolism; D014776:Virus Cultivation / Q000379:methods*; D014779:Virus Replication
chemical_list: D036022:Capsid Proteins