Influenza Division, National Center for Immunization and Respiratory Diseases,Centers for Disease Control and Prevention, Atlanta, GA, USA.
J Virol. 2011 Oct;85(19):10117-25. doi: 10.1128/JVI.05101-11. Epub 2011 Jul 20.
Highly pathogenic avian influenza (HPAI) H7 virus infection in humans frequently results in conjunctivitis as a major symptom. However, our understanding of what properties govern virus subtype-specific tropism, and of the host responses responsible for eliciting ocular inflammation and pathogenicity following influenza virus infection, are not well understood. To study virus-host interactions in ocular tissue, we infected primary human corneal and conjunctival epithelial cells with H7, H5, and H1 subtype viruses. We found that numerous virus subtypes were capable of infecting and replicating in multiple human ocular cell types, with the highest titers observed with highly pathogenic H7N7 and H5N1 viruses. Similar patterns of proinflammatory cytokine and chemokine production following influenza virus infection were observed in ocular and respiratory cells. However, primary ocular cells infected with HPAI H7N7 viruses were found to have elevated levels of interleukin-1β (IL-1β), a cytokine previously implicated in ocular disease pathology. Furthermore, H7N7 virus infection of corneal epithelial cells resulted in enhanced and significant increases in the expression of genes related to NF-κB signal transduction compared with that after H5N1 or H1N1 virus infection. The differential induction of cytokines and signaling pathways in human ocular cells following H7 virus infection marks the first association of H7 subtype-specific host responses with ocular tropism and pathogenicity. In particular, heightened expression of genes related to NF-κB-mediated signaling transduction following HPAI H7N7 virus infection in primary corneal epithelial cells, but not respiratory cells, identifies activation of a signaling pathway that correlates with the ocular tropism of influenza viruses within this subtype.
高致病性禽流感 (HPAI) H7 病毒感染人类常导致结膜炎作为主要症状。然而,我们对于哪些特性决定病毒亚型特异性趋向性,以及在流感病毒感染后引发眼部炎症和致病性的宿主反应的理解还不够深入。为了研究眼部组织中的病毒-宿主相互作用,我们用 H7、H5 和 H1 亚型病毒感染原代人角膜和结膜上皮细胞。我们发现许多病毒亚型能够感染和复制多种人眼细胞类型,其中高致病性 H7N7 和 H5N1 病毒的滴度最高。在眼部和呼吸道细胞中,流感病毒感染后观察到相似的促炎细胞因子和趋化因子产生模式。然而,感染 HPAI H7N7 病毒的原代眼部细胞发现白细胞介素-1β(IL-1β)水平升高,该细胞因子先前与眼部疾病病理学有关。此外,与 H5N1 或 H1N1 病毒感染相比,H7N7 病毒感染角膜上皮细胞导致与 NF-κB 信号转导相关的基因表达显著增强。H7 病毒感染人眼部细胞后细胞因子和信号通路的差异诱导标志着首次将 H7 亚型特异性宿主反应与眼部趋向性和致病性联系起来。特别是,HPAI H7N7 病毒感染原代角膜上皮细胞而不是呼吸道细胞后与 NF-κB 介导的信号转导相关的基因表达上调,鉴定出与该亚型中流感病毒的眼部趋向性相关的信号通路的激活。