Characterization of exosome cargoes of Culex tarsalis cells with West Nile virus

Western Encephalitis mosquitoes, Culex tarsalis, deliver painful bites and serve as transmission vectors for many arboviruses including West Nile virus. Understanding mosquito-pathogen interactions is of paramount importance for developing novel pest control strategies and mitigating the transmission of zoonotic pathogens. Recent evidence suggests that exosomes, a population of extracellular vesicles with a size range of 40-160 nm that carry protein and RNA cargoes, may play an important role in viral transmission by mosquitoes. Currently, little is known about the composition of insect exosomes or the roles they play in C. tarsalis viral transmission. Label-free proteomic and small RNA libraries were constructed of exosome samples from CxTr cells, an embryonic C. tarsalis cell line, with and without West Nile virus infection. These libraries were used to identify differential protein and small RNA expression between exosomes from mock- and West Nile virus-infected cells. These results will deepen our understanding of exosome biology and facilitate future development of new methods to disrupt viral transmission by Culex mosquitoes.