Molecular and biological analysis of echovirus 9 strain isolated from a diabetic child.
The full-length infectious cDNA clone was constructed and sequenced from the strain DM of echovirus 9, which was recently isolated from a 6-week-old child at the clinical onset of type 1 diabetes. Parallel with the isolate DM, the full-length infectious cDNA clone of the prototype strain echovirus 9 Barty (Barty-INF), was constructed and sequenced. Genetic relationships of the sequenced echo 9 viruses to the other members of the human enterovirus type B species were studied by phylogenetic analyses. Comparison of capsid protein sequences showed that the isolate DM was closely related to both prototype strains: Hill and Barty-INF. The only exception was the inner capsid protein VP4 where serotype specificity was not evident and the isolate DM clustered with the strain Hill and the strain Barty-INF with echovirus 30 Bastianni. Likewise, the nonstructural protein coding region, P2P3, of isolate DM was more similar to strain Hill than to strain Barty-INF. However, like echovirus 9 Barty, the isolate DM contained the RGD-motif in the carboxy terminus of capsid protein VP1. By blocking experiments using an RGD-containing peptide and a polyclonal rabbit antiserum to the alpha(v)beta(3)-integrin, it was shown that this molecule works as a cellular receptor for isolate DM. By using primary human islets, it was shown that the isolate DM is capable of infecting insulin-producing beta-cells like the corresponding prototype strains did. However, only isolate DM was clearly cytolytic for beta-cells. The infectious clones that were made allow further investigations of the molecular features responsible for the diabetogenicity of the isolate DM.
Paananen
Anja
A
Enterovirus Laboratory, National Public Health Institute (KTL), Helsinki, Finland.
Ylipaasto
Petri
P
Rieder
Elizabeth
E
Hovi
Tapani
T
Galama
Jochem
J
Roivainen
Merja
M
D036022:Capsid Proteins / Q000235:genetics; D003922:Diabetes Mellitus, Type 1 / Q000821:virology*; D004459:Echovirus 9 / Q000145:classification / Q000235:genetics / Q000472:pathogenicity*; D004457:Echovirus Infections / Q000821:virology; D006801:Humans; D007223:Infant; D007328:Insulin / Q000378:metabolism; D007515:Islets of Langerhans / Q000502:physiology / Q000821:virology; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D017361:Viral Nonstructural Proteins / Q000235:genetics; D010948:Viral Plaque Assay
D036022:Capsid Proteins; D007328:Insulin; D017361:Viral Nonstructural Proteins