Antigenic and Genetic Diversity of Equine Rotaviruses

Equine rotavirus is one of the most significant causes of foal diarrhea, which has a big economic impact on annual $122 billion U.S. equine industry. Control strategies for equine rotavirus are very limited. Little is known about the genetic basis of equine rotaviral antigenic diversity as well as the impact of emerging variants of concern on antibody-mediated protection for this important disease. The primary hurdle to address these important knowledge gaps is a lack of reagents and tools, which will be addressed in this proposal. We will develop reverse genetics systems representing contemporary equine rotavirus G3 and G14 isolates. We will then utilize this platform to elucidate the genetic determinants of antigenic diversity and determine the level of the cross- protection of most prevalent equine G3 and G14 rotaviruses in horses. Finally, we will study the biodiversity of equine rotavirus isolates from a wide geographical range and determine their antigenic and genetic relationship to our reference equine G3 and G14 strains. Successful completion of proposed work will enable us to develop reverse genetics systems that can be further employed to study the underlying mechanisms that promote equine rotavirus replication and disease as well as to identify immune correlates of protection. This work will also provide novel insights into the genetic basis of viral antigenic diversity and antibody correlates of protection. Our work aligns well with the USDA/NIFA priority described in Program Code: A1221, as it seeks to mitigate a serious pathogen of horses, which is responsible for significant equine industry losses.