Biological, antigenic and phylogenetic characterization of the flavivirus Alfuy.
Alfuy virus (ALFV) is classified as a subtype of the flavivirus Murray Valley encephalitis virus (MVEV); however, despite preliminary reports of antigenic and ecological similarities with MVEV, ALFV has not been associated with human disease. Here, it was shown that ALFV is at least 10(4)-fold less neuroinvasive than MVEV after peripheral inoculation of 3-week-old Swiss outbred mice, but ALFV demonstrates similar neurovirulence. In addition, it was shown that ALFV is partially attenuated in mice that are deficient in alpha/beta interferon responses, in contrast to MVEV which is uniformly lethal in these mice. To assess the antigenic relationship between these viruses, a panel of monoclonal antibodies was tested for the ability to bind to ALFV and MVEV in ELISA. Although the majority of monoclonal antibodies recognized both viruses, confirming their antigenic similarity, several discriminating antibodies were identified. Finally, the entire genome of the prototype strain of ALFV (MRM3929) was sequenced and phylogenetically analysed. Nucleotide (73 %) and amino acid sequence (83 %) identity between ALFV and MVEV confirmed previous reports of their close relationship. Several nucleotide and amino acid deletions and/or substitutions with putative functional significance were identified in ALFV, including the abolition of a conserved glycosylation site in the envelope protein and the deletion of the terminal dinucleotide 5'-CU(OH)-3' found in all other members of the genus. These findings confirm previous reports that ALFV is closely related to MVEV, but also highlights significant antigenic, genetic and phenotypic divergence from MVEV. Accordingly, the data suggest that ALFV is a distinct species within the serogroup Japanese encephalitis virus.
May
Fiona J
FJ
Department of Microbiology and Parasitology, School of Molecular and Microbial Sciences, The University of Queensland, Building 76, Cooper Road, St Lucia, QLD 4072, Australia.
Lobigs
Mario
M
Division of Immunology and Cell Biology, John Curtin School of Medical Research, The Australian National University, Canberra, Australia.
Lee
Eva
E
Division of Immunology and Cell Biology, John Curtin School of Medical Research, The Australian National University, Canberra, Australia.
Gendle
Debra J
DJ
Department of Microbiology and Parasitology, School of Molecular and Microbial Sciences, The University of Queensland, Building 76, Cooper Road, St Lucia, QLD 4072, Australia.
Mackenzie
John S
JS
Department of Microbiology and Parasitology, School of Molecular and Microbial Sciences, The University of Queensland, Building 76, Cooper Road, St Lucia, QLD 4072, Australia.
Broom
Annette K
AK
Department of Microbiology and Immunology, School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Nedlands, Australia.
Conlan
James V
JV
Department of Microbiology and Parasitology, School of Molecular and Microbial Sciences, The University of Queensland, Building 76, Cooper Road, St Lucia, QLD 4072, Australia.
Hall
Roy A
RA
Department of Microbiology and Parasitology, School of Molecular and Microbial Sciences, The University of Queensland, Building 76, Cooper Road, St Lucia, QLD 4072, Australia.
D000818:Animals; D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D000956:Antigens, Viral / Q000276:immunology*; D005416:Flavivirus / Q000145:classification* / Q000235:genetics / Q000276:immunology; D018177:Flavivirus Infections / Q000662:veterinary* / Q000821:virology; D016679:Genome, Viral; D051379:Mice; D008969:Molecular Sequence Data; D010802:Phylogeny
D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D000956:Antigens, Viral