Scholarly Works, Fralin Life Sciences Institute

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https://hdl.handle.net/10919/25797

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Browsing Scholarly Works, Fralin Life Sciences Institute by Department "Center for Emerging, Zoonotic, and Arthropod-borne Pathogens"

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    La Crosse Virus Shows Strain-Specific Differences in Pathogenesis
    Wilson, Sarah N.; López, Krisangel; Coutermarsh-Ott, Sheryl; Auguste, Dawn I.; Porier, Danielle L.; Armstrong, Philip M.; Andreadis, Theodore G.; Eastwood, Gillian; Auguste, A. Jonathan (MDPI, 2021-03-29)
    La Crosse virus (LACV) is the leading cause of pediatric viral encephalitis in North America, and is an important public health pathogen. Historically, studies involving LACV pathogenesis have focused on lineage I strains, but no former work has explored the pathogenesis between or within lineages. Given the absence of LACV disease in endemic regions where a robust entomological risk exists, we hypothesize that some LACV strains are attenuated and demonstrate reduced neuroinvasiveness. Herein, we compared four viral strains representing all three lineages to determine differences in neurovirulence or neuroinvasiveness using three murine models. A representative strain from lineage I was shown to be the most lethal, causing >50% mortality in each of the three mouse studies. However, other strains only presented excessive mortality (>50%) within the suckling mouse neurovirulence model. Neurovirulence was comparable among strains, but viruses differed in their neuroinvasive capacities. Our studies also showed that viruses within lineage III vary in pathogenesis with contemporaneous strains, showing reduced neuroinvasiveness compared to an ancestral strain from the same U.S. state (i.e., Connecticut). These findings demonstrate that LACV strains differ markedly in pathogenesis, and that strain selection is important for assessing vaccine and therapeutic efficacies.
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    Optimized production and immunogenicity of an insect virus-based chikungunya virus candidate vaccine in cell culture and animal models
    Adam, Awadalkareem; Luo, Huanle; Osman, Samantha R.; Wang, Binbin; Roundy, Christopher M.; Auguste, A. Jonathan; Plante, Kenneth S.; Peng, Bi-Hung; Thangamani, Saravanan; Frolova, Elena I.; Frolov, Ilya; Weaver, Scott C.; Wang, Tian (2021-01-01)
    A chimeric Eilat/ Chikungunya virus (EILV/CHIKV) was previously reported to replicate only in mosquito cells but capable of inducing robust adaptive immunity in animals. Here, we initially selected C7/10 cells to optimize the production of the chimeric virus. A two-step procedure produced highly purified virus stocks, which was shown to not cause hypersensitive reactions in a mouse sensitization study. We further optimized the dose and characterized the kinetics of EILV/CHIKV-induced immunity. A single dose of 10(8) PFU was sufficient for induction of high levels of CHIKV-specific IgM and IgG antibodies, memory B cell and CD8(+) T cell responses. Compared to the live-attenuated CHIKV vaccine 181/25, EILV/CHIKV induced similar levels of CHIKV-specific memory B cells, but higher CD8(+) T cell responses at day 28. It also induced stronger CD8(+), but lower CD4(+) T cell responses than another live-attenuated CHIKV strain (CHIKV/IRES) at day 55 post-vaccination. Lastly, the purified EILV/CHIKV triggered antiviral cytokine responses and activation of antigen presenting cell (APC)s in vivo, but did not induce APCs alone upon in vitro exposure. Overall, our results demonstrate that the EILV/CHIKV vaccine candidate is safe, inexpensive to produce and a potent inducer of both innate and adaptive immunity in mice.