Contribution of Host Immune Responses Against Influenza D Virus Infection Toward Secondary Bacterial Infection in a Mouse Model
Contribution of Host Immune Responses Against Influenza D Virus Infection Toward Secondary Bacterial Infection in a Mouse Model
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DOI：
10.3390/v11110994
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发表时间：
2019-11-01
期刊：
影响因子：
4.7
通讯作者：
Rynda-Apple, Agnieszka
中科院分区：
文献类型：
--
作者：
Skelton, Raegan M.;Shepardson, Kelly M.;Rynda-Apple, Agnieszka
已知D型流感病毒（IDV）与牛和其他反刍动物中的病毒和细菌病原体共循环。目前，关于宿主对IDV感染的反应以及IDV感染是否影响宿主对继发性细菌感染的易感性的知识有限。为了开始解决这一知识缺口，当前的研究使用体内和体外方法的组合来评价宿主细胞对原发性IDV感染和继发性金黄色葡萄球菌（S。 aureus)具有良好的抗菌活性。在小鼠中初次感染IDV不会导致疾病的临床体征，也不会增加对继发性S.金黄色葡萄球菌感染。相反，IDV感染似乎可以保护小鼠免受继发性细菌感染的常见临床特征，如与S.单独的金黄色葡萄球菌感染。我们利用人肺泡上皮A549细胞分析IDV感染早期抗病毒反应，发现IDV感染后IFN-β表达显著增加。这些结果首次证明，IDV感染不会增加继发性链球菌感染的易感性。金黄色葡萄球菌，有证据表明，IDV感染期间的抗病毒免疫应答可能保护宿主免受这些潜在致命结果的影响。
Influenza D viruses (IDV) are known to co-circulate with viral and bacterial pathogens in cattle and other ruminants. Currently, there is limited knowledge regarding host responses to IDV infection and whether IDV infection affects host susceptibility to secondary bacterial infections. To begin to address this gap in knowledge, the current study utilized a combination of in vivo and in vitro approaches to evaluate host cellular responses against primary IDV infection and secondary bacterial infection with Staphylococcus aureus (S. aureus). Primary IDV infection in mice did not result in clinical signs of disease and it did not enhance the susceptibility to secondary S. aureus infection. Rather, IDV infection appeared to protect mice from the usual clinical features of secondary bacterial infection, as demonstrated by improved weight loss, survival, and recovery when compared to S. aureus infection alone. We found a notable increase in IFN-beta expression following IDV infection while utilizing human alveolar epithelial A549 cells to analyze early anti-viral responses to IDV infection. These results demonstrate for the first time that IDV infection does not increase the susceptibility to secondary bacterial infection with S. aureus, with evidence that anti-viral immune responses during IDV infection might protect the host against these potentially deadly outcomes.