Department of Microbiology & Immunology, University of South Alabama Mobile, Alabama, United States.
Invest Ophthalmol Vis Sci. 2019 Sep 3;60(12):3952-3962. doi: 10.1167/iovs.19-27810.
γδ T cells offer an important early immune defense against many different pathogens, both bacterial and viral. Herein, we examined the capacity of γδ T cell subsets to provide protection in the cornea against herpes simplex virus-1 (HSV-1).
C57Bl/6 (wild-type [WT]), γδ T-cell deficient (TCRδ-/-) and CCR6-deficient (CCR6-/-) mice were infected intracorneally with HSV-1. At multiple time points following infection, corneas were excised, and cells were immunostained for surface markers, intracellular cytokines, and analyzed using flow cytometry. WT and CCR6-/- γδ T cells were adoptively transferred into TCRδ-/- mice and corneal scores and survival were measured.
Intracorneal infection of mice lacking γδ T cells exhibited increased corneal opacity scores, elevated viral titers, and higher mortality compared with WT mice. Both CCR6+ and CCR6neg γδ T cell subsets were observed in corneas after virus infection. CCR6+ γδ T cells produced IL-17A and were predominantly CD44+CD62L+, consistent with natural IL-17+ γδ T cells. In contrast IL-17A production by CCR6neg γδ T cells was infrequent, and this subset was largely single positive for CD62L or CD44. The CCR6+ subset appeared to provide protection against HSV-1 as follows: (1) CCR6-/- mice had more severe corneal opacity compared with WT mice; and (2) adoptive transfer of γδ T cells from WT mice restored protection in TCRδ-/- mice whereas transfer of γδ T cells from CCR6-/- mice did not.
γδ T cells in the cornea can be divided into CCR6+ and CCR6neg subsets with the former conferring protection early after intracorneal HSV-1 infection.
γδ T 细胞提供了针对许多不同病原体(包括细菌和病毒)的重要早期免疫防御。在此,我们研究了 γδ T 细胞亚群在角膜中抵抗单纯疱疹病毒 1(HSV-1)的能力。
C57Bl/6(野生型[WT])、γδ T 细胞缺陷(TCRδ-/-)和 CCR6 缺陷(CCR6-/-)小鼠通过角膜内感染 HSV-1。在感染后的多个时间点,切除角膜,对细胞进行表面标志物、细胞内细胞因子免疫染色,并使用流式细胞术进行分析。将 WT 和 CCR6-/-γδ T 细胞过继转移到 TCRδ-/-小鼠中,并测量角膜评分和存活率。
与 WT 小鼠相比,缺乏 γδ T 细胞的小鼠角膜内感染表现出更高的角膜混浊评分、更高的病毒滴度和更高的死亡率。在病毒感染后,CCR6+和 CCR6negγδ T 细胞亚群都在角膜中被观察到。CCR6+γδ T 细胞产生 IL-17A,并且主要是 CD44+CD62L+,与天然 IL-17+γδ T 细胞一致。相比之下,CCR6negγδ T 细胞产生 IL-17A 的情况很少见,并且该亚群主要是 CD62L 或 CD44 的单阳性。CCR6+亚群似乎为 HSV-1 提供了保护,如下所示:(1)与 WT 小鼠相比,CCR6-/-小鼠的角膜混浊更严重;(2)WT 小鼠来源的 γδ T 细胞过继转移恢复了 TCRδ-/-小鼠的保护作用,而 CCR6-/-小鼠来源的 γδ T 细胞过继转移则没有。
角膜中的 γδ T 细胞可以分为 CCR6+和 CCR6neg 亚群,前者在角膜内 HSV-1 感染后早期提供保护。