Department of Ophthalmology, Hyogo Medical University, Nishinomiya, Japan.
Department of Immunology, Hyogo Medical University, Nishinomiya, Japan.
Allergol Int. 2023 Apr;72(2):324-331. doi: 10.1016/j.alit.2022.10.003. Epub 2022 Oct 29.
Interleukin-33 (IL-33) is involved in type 2 innate immunity by inducing type 2 cytokines, such as IL-5 and IL-13, through the activation of group 2 innate lymphoid cells (ILC2s) or T helper 2 (Th2) cells. We previously reported that mice overexpressing IL-33 (IL-33Tg) in the cornea and conjunctiva spontaneously develop atopic keratoconjunctivitis-like inflammation. Despite previous studies, it is not fully understood what types of immune cells contribute to the disease process of IL-33-induced keratoconjunctivitis.
To defect Th2 cells, IL-33Tg mice were crossed with Rag2KO mice. To defect ILC2s, IL-33Tg mice received bone marrow transplantations from B6.C3(Cg)-Rorasg/J mice that lacked ILC2. Immunostaining techniques were used to determine where ILC2 is distributed in the cornea and conjunctiva. We analyzed the transcriptomes of ILC2 from the conjunctiva by using single-cell RNA-seq analysis. To investigate whether tacrolimus reduces type 2 cytokine production by ILC2, ILC2 was cultured with tacrolimus, and the percentage of cytokine-producing ILC2 was examined. To investigate whether tacrolimus can inhibit IL-33-induced keratoconjunctivitis in vivo, IL-33Tg mice were treated with tacrolimus eye drops.
ILC2 infiltrated the conjunctival epithelium and subepithelial tissue. Keratoconjunctivitis developed spontaneously in Rag2KO/IL-33Tg mice, but keratoconjunctivitis was abolished in IL-33Tg mice lacking ILC2. ILC2 was not a uniform cluster but a heterogeneous cluster. Tacrolimus inhibited cytokine production from ILC2s in vitro, and tacrolimus eye drops inhibited keratoconjunctivitis in IL-33Tg mice in vivo.
ILC2 plays a pivotal role in IL-33-induced keratoconjunctivitis in mice.
白细胞介素-33（IL-33）通过激活 2 型固有淋巴细胞（ILC2）或辅助性 T 细胞 2（Th2）细胞，诱导 2 型细胞因子（如 IL-5 和 IL-13），参与 2 型先天免疫。我们之前的研究报告称，在角膜和结膜中过表达白细胞介素-33（IL-33）的小鼠会自发地发展出类似特应性角膜炎的炎症。尽管有之前的研究，但仍不完全清楚哪种免疫细胞类型会导致 IL-33 诱导的角膜炎的疾病进程。
为了缺陷 Th2 细胞，将 IL-33Tg 小鼠与 Rag2KO 小鼠交配。为了缺陷 ILC2，IL-33Tg 小鼠接受来自缺乏 ILC2 的 B6.C3（Cg）-Rorasg/J 小鼠的骨髓移植。免疫染色技术用于确定 ILC2 在角膜和结膜中的分布位置。我们通过单细胞 RNA-seq 分析对结膜中的 ILC2 转录组进行了分析。为了研究他克莫司是否通过 ILC2 减少 2 型细胞因子的产生，我们用他克莫司培养 ILC2，并检查产生细胞因子的 ILC2 的百分比。为了研究他克莫司是否可以抑制体内 IL-33 诱导的角结膜炎，我们用他克莫司滴眼液处理 IL-33Tg 小鼠。
ILC2 浸润结膜上皮和上皮下组织。Rag2KO/IL-33Tg 小鼠自发发生角结膜炎，但缺乏 ILC2 的 IL-33Tg 小鼠中角结膜炎消失。ILC2 不是一个均匀的簇，而是一个异质的簇。他克莫司在体外抑制 ILC2 细胞因子的产生，他克莫司滴眼液抑制体内 IL-33Tg 小鼠的角结膜炎。
ILC2 在小鼠的 IL-33 诱导的角结膜炎中起关键作用。
