Characterization of Nairovirus infection in tick cell lines

Crimean-Congo hemorrhagic fever (CCHF) is a severe tick-borne disease caused by the CCHF virus (CCHFV), a member of the Nairoviridae family. Due to the high pathogenicity in humans and the lack of specific drugs and vaccines, CCHFV is manipulated under biosafety level (BSL) 4 conditions. Ticks are persistently infected by CCHFV and represent the natural reservoir. To date, very few information is available about the virus-vector interaction due to biosafety concerns on the use of infected ticks in BSL4 facilities. The aim of this work is to get light on the virus-vector interaction using an in vitro model based on tick cells and the Hazara virus (HAZV), a surrogate of CCHFV. HAZV, which shares the genus (Orthonairovirus) and serogroup with CCHFV, is not pathogenic for humans and can be easily manipulated in the BSL2 laboratory. Virological and cellular parameters will be evaluated in ticks infected cells to investigate the virus adaptation and the cell response to viral infection during the establishment of the persistent infection.