Immunological findings of West Caucasian bat virus in an accidental host

Although all lyssaviruses cause fatal encephalomyelitis in mammals, they display a different host tropism and pathogenicity, with the ecology of Rabies virus (RABV) continually evolving and adapting to new host species. In 2020, West Caucasian bat virus (WCBV) was identified as the causative agent of rabies in a domestic cat in Italy. This event raised concerns about its public health consequences, due to the absence of biologicals against the infection. Our study investigates the host immune response triggered by WCBV in comparison with a pathogenic strain of RABV and the low pathogenic Duvenhage lyssavirus (DUVV), as a proxy to understand the mechanisms leading to lyssavirus spillover and pathogenicity. We overall confirm that previous evidence indicating an inverse relationship between lyssavirus pathogenicity and immune response is applicable for WCBV as well. Importantly, this work represents the first transcriptomic analysis of the WCBV interaction in the central nervous system with an accidental host.