The Role of IL-17 in fungal keratitis

IL-17在真菌性角膜炎中的作用

• 批准号: 8398091
• 负责人: Patricia R Taylor
• 金额: $ 5.22万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-01 至 2014-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8398091
• 关键词: Adoptive Transfer; Antifungal Agents; Aspergillus; Biological Assay; Blindness; Bone Marrow; C57BL/6 Mouse; CD4 Positive T Lymphocytes; Cells; Cornea; Corneal Diseases; Corneal Opacity; Corneal Stroma; Corneal Ulcer; Data; Development; Disease; EMSA; Flow Cytometry; Fusarium; Hyphae; IL8RB gene; Immune response; Immunity; Immunization; In Vitro; Incubated; Infection; Interferons; Interleukin-16; Interleukin-17; Interleukin-6; Keratitis; Lead; Manuscripts; Mediating; Messenger RNA; Modeling; Mus; Mycoses; Nuclear Extract; Phenotype; Population; Production; Promoter Regions; RNA; Reactive Oxygen Species; Recombinants; Recruitment Activity; Regulation; Relative (related person); Role; Route; STAT3 gene; Sorting - Cell Movement; Source; Spleen; Splenocyte; Th1 Cells; Time; Transcript; Visual impairment; Western Blotting; abstracting; adaptive immunity; cell type; chemokine; interleukin-23; killings; mRNA Expression; magnetic beads; neutralizing antibody; neutrophil; novel; research study; subcutaneous

DESCRIPTION (provided by applicant): IL-17 and Th17 cells have an important role in the host response to fungal infections. In the current study, we examined the role of IL-17 in a murine model of Aspergillus and Fusarium infections of the cornea, which are a major cause of blindness and visual impairment worldwide. C57BL/6 mice immunized by intratracheal or subcutaneous routes. Mice immunized by either route demonstrated rapid fungal clearance and significantly reduced corneal disease compared with unimmunized, infected mice which severe corneal opacity and a persistent fungal presence. Intracellular flow cytometry showed development of fungal-specific Th1 and Th17 cells in the spleen following immunization, which were selectively recruited to the cornea after infection (Th17 cells at 48h, and Th1 cells at 72h). Neutralization of IL-17 following immunization, or infection of IL-17-/- mice inhibited the protective phenotype, whereas IFN-? neutralization had no effect. A discrete population of IL-17 producing neutrophils was detected in the corneas 24h after infection corneas of immunized, but not unimmunized mice, and were detected in the spleen and bone marrow. Further, neutrophil depletion impaired IL-17 production at this time and blocked protective immunity. IL-17 producing neutrophils produced elevated ROS and had increased capacity to kill hyphae in vitro, indicating that this population of cells has an important role in regulating fungal infectio. Quantitative PCR of the FACS sorted IL-17 neutrophils from the cornea, spleen and bone marrow showed IL-17 transcripts, indicating de novo synthesis. Further, naive bone marrow neutrophils expressed IL-17 RNA when incubated with splenocyte supernatants from immunized mice, and expression was ablated in the presence of both anti-IL-6 and anti-IL-23. Conversely, stimulation with both IL-16 and IL-23, but not with single Abs stimulated IL-17 expression. Together, these data indicate that IL-17 producing neutrophils are generated by IL-6 and IL-23 in immunized mice, and are recruited to fungal infected corneas, resulting in rapid fungal clearance possibly due to elevated production of reactive oxygen species or interactions with Th17 cells. These findings show a role for IL-17, Th17, and IL-17 producing neutrophils in regulating fungal infections. In the proposed experiments I will determine the relative contribution of Th17 cells and IL-17 producing cells in protective immunity in fungal keratitis. ) PUBLIC HEALTH RELEVANCE: Project narrative: Fungal keratitis is one of the leading causes of corneal ulcers, visual impairment, and blindness. In many cases the current anti-fungal treatments for this infection are not adequate in resolving the disease. However, the results from the proposed studies could lead to proper regulation and novel therapies for this debilitating infection.

描述（由申请人提供）：IL-17 和 Th17 细胞在宿主对真菌感染的反应中发挥重要作用。在当前的研究中，我们研究了 IL-17 在角膜曲霉菌和镰刀菌感染的小鼠模型中的作用，这些感染是全世界失明和视力障碍的主要原因。 C57BL/6小鼠通过气管内或皮下途径免疫。与未免疫、感染的小鼠相比，通过任一途径免疫的小鼠均表现出快速的真菌清除能力，并显着减少了角膜疾病，而感染的小鼠出现严重的角膜混浊和持续的真菌存在。细胞内流式细胞术显示，免疫后脾脏中出现了真菌特异性 Th1 和 Th17 细胞，这些细胞在感染后选择性地募集至角膜（48 小时时的 Th17 细胞，72 小时时的 Th1 细胞）。 免疫后IL-17的中和或IL-17-/-小鼠的感染抑制了保护性表型，而IFN-α中和没有效果。 在感染免疫小鼠而非未免疫小鼠的角膜后24小时，在角膜中检测到产生IL-17的中性粒细胞的离散群体，并且在脾脏和骨髓中检测到。此外，中性粒细胞耗竭此时损害了 IL-17 的产生并阻断了保护性免疫。产生 IL-17 的中性粒细胞产生的 ROS 升高，并且体外杀死菌丝的能力增强，表明该细胞群在调节真菌感染中具有重要作用。来自角膜、脾脏和骨髓的 FACS 分选的 IL-17 中性粒细胞的定量 PCR 显示了 IL-17 转录物，表明从头合成。此外，当与免疫小鼠的脾细胞上清液一起孵育时，幼稚骨髓中性粒细胞表达IL-17 RNA，并且在抗IL-6和抗IL-23存在的情况下表达被消除。相反，用IL-16和IL-23刺激IL-17表达，但用单一抗体刺激则不刺激IL-17表达。总之，这些数据表明，产生 IL-17 的中性粒细胞是由免疫小鼠中的 IL-6 和 IL-23 产生的，并被募集到真菌感染的角膜，导致真菌快速清除，这可能是由于活性氧的产生增加或与 Th17 细胞的相互作用所致。这些发现表明 IL-17、Th17 和产生 IL-17 的中性粒细胞在调节真菌感染中发挥作用。在拟议的实验中，我将确定 Th17 细胞和 IL-17 产生细胞在真菌性角膜炎的保护性免疫中的相对贡献。 ） 公共卫生相关性： 项目叙述：真菌性角膜炎是角膜溃疡、视力障碍和失明的主要原因之一。在许多情况下，目前针对这种感染的抗真菌治疗不足以解决该疾病。然而，拟议研究的结果可能会导致对这种使人衰弱的感染进行适当的监管和新的疗法。