Toscana virus induces interferon although its NSs protein reveals antagonistic activity.
Toscana virus (TOSV) is a phlebotomus-transmitted virus that belongs to the family Bunyaviridae and causes widespread infections in humans; about 30 % of these cases result in aseptic meningitis. In the present study, it was shown that TOSV is an inducer of beta interferon (IFN-β), although its non-structural protein (NSs) could inhibit the induction of IFN-β if expressed in a heterologous context. A recombinant Rift Valley fever virus expressing the TOSV NSs could suppress IFN-β expression in infected cells. Moreover, in cells expressing NSs protein from a cDNA plasmid, IFN-β transcripts were not inducible by poly(I : C). Unlike other members of the family Bunyaviridae, TOSV appears to express an NSs protein that is a weak antagonist of IFN induction. Characterization of the interaction of TOSV with the IFN system will help our understanding of virus-host cell interactions and may explain why the pathogenesis of this disease is mostly mild in humans.
Gori Savellini
Gianni
G
Department of Molecular Biology, Microbiology Section, University of Siena, 53100 Siena, Italy.
Weber
Friedemann
F
Terrosi
Chiara
C
Habjan
Matthias
M
Martorelli
Barbara
B
Cusi
Maria Grazia
MG
D000818:Animals; D002460:Cell Line; D005822:Genetic Vectors; D006801:Humans; D016899:Interferon-beta / Q000037:antagonists & inhibitors* / Q000096:biosynthesis*; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D012296:Rift Valley fever virus / Q000235:genetics; D029301:Sandfly fever Naples virus / Q000276:immunology*; D017361:Viral Nonstructural Proteins / Q000235:genetics / Q000276:immunology*
D011994:Recombinant Proteins; D017361:Viral Nonstructural Proteins; D016899:Interferon-beta