First reverse genetics systems for Toscana virus

Toscana virus (TOSV) is a Phlebovirus in the Phenuiviridae family, order Bunyavirales, found in the countries surrounding the Mediterranean. TOSV is an arthropod-borne virus leading to seasonal acute meningitis/encephalitis during the summer. However, and despite its significant impact on the human health, this virus has been so far neglected and till today no reverse genetic system was available to study it at the molecular level. Two main genetic lineages have been identified from the field (Lineages A and B). Thanks to our collaborations with Wageningen Bioveterinary Research (WBR; Jeroen Kortekaas) and the Centre for Virus Research (CVR/Glasgow; Alain Kohl), we set up two reverse genetic systems for these two TOSV lineages. Deleting the NSs open reading frame of the TOSV genome allowed us to generate viruses expressing fluorescent reporter genes and to show that the NSs antagonizes the type-I interferon responses in the context of viral infection. These two reverse genetics system will help us to better understand the molecular and cellular mechanisms of this virus and to the design of novel attenuated vaccine candidates.

Alexander AJT, Confort MP, Desloire S, Dunlop JI, Kuchi S, Sreenu VB, Mair D, Wilkie GS, Da Silva Filipe A, Brennan B, Ratinier M, Arnaud F, Kohl A. Development of a Reverse Genetics System for Toscana Virus (Lineage A). Viruses 2020: 12(4).

Woelfl F, Léger P, Oreshkova N, Pahmeier F, Windhaber S, Koch J, Stanifer M, Roman Sosa G, Uckeley ZM, Rey FA, Boulant S, Kortekaas J, Wichgers Schreur PJ, Lozach PY. Novel Toscana Virus Reverse Genetics System Establishes NSs as an Antagonist of Type I Interferon Responses. Viruses 2020: 12(4).