Abstract Summary/Description
Flaviviruses pose a significant global health threat, causing diseases that range from mild flu-like symptoms to severe hemorrhagic and neurological diseases. These viruses are typically spread by ticks or mosquito bites. Usutu virus (USUV) is a flavivirus currently circulating in Europe, with the potential to invade the central nervous system in humans. While neuroinvasive disease due to USUV is rare, it can result in severe conditions such as encephalitis, meningitis, and encephalomeningitis. This study aims to characterize USUV replication from peripheral sites through the central nervous system using in vivo mouse models, specifically C57BL/6 Wild-Type (WT) mice, type I interferon-deficient (IFNAR1-/-) mice, and type I and II interferon-deficient (AG129) mice. Our results showed that IFNAR1-/- and AG129 mice are highly susceptible to USUV infection, resulting in 100% mortality. WT mice exhibited lower viral replication in peripheral organs compared to IFNAR1-/- and AG129 mice. In addition, flow cytometry data showed high induction of T cell and B cell immune response along with innate immune response in all three mouse models. Additionally, immune responses were analyzed through qRT-PCR and multiplex immunoassay to observe transcriptional and translational changes following USUV infection. In conclusion, the data obtained from this study provides valuable insights into the viral replication kinetics and immune responses to USUV infection in vivo.