Invariant natural killer (iNKT) cells are among the first innate immune cells to elicit early protective immunity that controls invading viral pathogens. The role of the iNKT cell subsets iNKT1, iNKT2, and iNKT17 in herpesvirus immunity remains to be fully elucidated. In this study, we examined the protective role of cornea-resident iNKT cell subsets using the mouse model of ocular herpesvirus infection and disease. Wild-type (WT) C57BL/6 (B6) mice and CD1d knockout (KO) mice were infected ocularly with herpes simplex virus 1 (HSV-1) (strain McKrae). Cornea, spleen, and liver were harvested at 0, 2, 5, 8, and 14 days postinfection (p.i.), and the frequency and function of the three major iNKT cell subsets were analyzed and correlated with symptomatic and asymptomatic corneal herpesvirus infections. The profiles of 16 major pro- and anti-inflammatory cytokines were analyzed in corneal lysates using Western blot and Luminex assays. Early during ocular herpesvirus infection (i.e., day 2), the gamma interferon (IFN-γ)-producing PLZFloRORγtlo (promyelocytic leukemia zinc finger, retinoic acid-related orphan receptor gT) iNKT1 cell subset was the predominant iNKT cell subset in infected asymptomatic corneas. Moreover, compared to the asymptomatic corneas of HSV-1-infected WT mice, the symptomatic corneas CD1d KO mice, with iNKT cell deficiency, had increased levels of the inflammatory cytokine interleukin-6 (IL-6) and decreased levels of IL-12, IFN-γ, and the JAK1, STAT1, NF-κB, and extracellular signal-regulated kinase 1/2 (ERK1/2) pathways. Our findings suggest that IFN-γ-producing PLZFloRORγtlo iNKT1 cells play a role in the protective innate immune response against symptomatic ocular herpes.IMPORTANCE We investigated the protective role of iNKT cell subsets in asymptomatic ocular herpesvirus infection. We found that early during ocular herpesvirus infection (i.e., on day 2 postinfection), IFN-γ-producing PLZFloRORγtlo iNKT1 cells were the predominant iNKT cell subset in infected corneas of asymptomatic B6 mice (with little to no corneal herpetic disease), compared to corneas of symptomatic mice (with severe corneal herpetic disease). Moreover, compared to asymptomatic corneas of wild-type (WT) B6 mice, the symptomatic corneas of CD1d KO mice, which lack iNKT cells, showed (i) decreases in the levels of IFN-γ and IL-12, (ii) an increase in the level of the inflammatory cytokine IL-6; and (iii) downregulation of the JAK1, STAT1, NF-κB, and ERK1/2 pathways. The findings suggest that early during ocular herpesvirus infection, cornea-resident IFN-γ-producing PLZFloRORγtlo iNKT1 cells provide protection from symptomatic ocular herpes.

中文翻译：

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产生 γ 干扰素的 PLZFloRORγtlo 恒定自然杀伤细胞 1 细胞浸润单纯疱疹病毒 1 感染的角膜的频率与无症状眼部疱疹病毒感染有关。


不变自然杀伤 (iNKT) 细胞是首批引发早期保护性免疫、控制入侵病毒病原体的先天免疫细胞之一。 iNKT 细胞亚群 iNKT1、iNKT2 和 iNKT17 在疱疹病毒免疫中的作用仍有待充分阐明。在这项研究中，我们使用眼部疱疹病毒感染和疾病的小鼠模型检查了角膜驻留 iNKT 细胞亚群的保护作用。野生型 (WT) C57BL/6 (B6) 小鼠和 CD1d 敲除 (KO) 小鼠经眼部感染单纯疱疹病毒 1 (HSV-1)（McKrae 株）。在感染后 0、2、5、8 和 14 天 (pi) 收获角膜、脾脏和肝脏，分析三个主要 iNKT 细胞亚群的频率和功能，并将其与有症状和无症状的角膜疱疹病毒感染相关联。使用蛋白质印迹和 Luminex 测定法分析角膜裂解物中 16 种主要促炎和抗炎细胞因子的概况。在眼部疱疹病毒感染早期（即第2天），产生γ干扰素（IFN-γ）的PLZFloRORγtlo（早幼粒细胞白血病锌指，视黄酸相关孤儿受体gT）iNKT1细胞亚群是感染的无症状角膜中的主要iNKT细胞亚群。此外，与HSV-1感染的WT小鼠的无症状角膜相比，iNKT细胞缺陷的有症状CD1d KO小鼠的角膜炎症细胞因子白介素6（IL-6）水平升高，而IL-12水平降低、IFN-γ 以及 JAK1、STAT1、NF-κB 和细胞外信号调节激酶 1/2 (ERK1/2) 通路。我们的研究结果表明，产生 IFN-γ 的 PLZFloRORγtlo iNKT1 细胞在针对症状性眼部疱疹的保护性先天免疫反应中发挥作用。重要性 我们研究了 iNKT 细胞亚群在无症状眼部疱疹病毒感染中的保护作用。我们发现，在眼部疱疹病毒感染早期（即感染后第 2 天），与无症状 B6 小鼠（很少或没有角膜疱疹疾病）相比，产生 IFN-γ 的 PLZFloRORγtlo iNKT1 细胞是受感染角膜的主要 iNKT 细胞亚群。有症状小鼠的角膜（患有严重的角膜疱疹病）。此外，与野生型（WT）B6小鼠的无症状角膜相比，缺乏iNKT细胞的CD1d KO小鼠的有症状角膜表现出（i）IFN-γ和IL-12水平降低，（ii）炎症细胞因子 IL-6 水平增加； (iii) JAK1、STAT1、NF-κB 和 ERK1/2 通路的下调。研究结果表明，在眼部疱疹病毒感染的早期，角膜中产生 IFN-γ 的 PLZFloRORγtlo iNKT1 细胞可提供针对症状性眼部疱疹的保护。