CCR3通过IL-33/CD34棕榈酰化在过敏性鼻炎中的作用：一项综合分析

文献信息

中文摘要

背景： 趋化因子受体的翻译后修饰在免疫调节中起着至关重要的作用，然而CCR3棕榈酰化在过敏性鼻炎（AR）中的具体作用仍不清楚。
目的： 本研究旨在探讨AR的生物信息学特征，并阐明CCR3棕榈酰化在AR中的潜在分子机制。
方法： 采用整合生物信息学方法，利用七种机器学习算法和基因集富集分析（GSEA），以识别AR中的关键转录组特征和通路。在体内，使用野生型和CCR3敲除小鼠建立过敏原诱导的AR模型，以评估组织病理学、Th2细胞因子谱和CD34+细胞浸润。采用酰基-生物素交换（ABE）试验定量CCR3棕榈酰化水平。在体外，使用原代骨髓来源的嗜酸性粒细胞（BM-Eos）探索CCR3棕榈酰化的上游驱动因素。进行siRNA敲低、定点突变和基因拯救实验，以确认特定的棕榈酰转移酶和修饰位点。
结果： 生物信息学筛选确定脂质代谢/棕榈酰化和IL-33/CD34轴是AR中的关键通路。体内实验证实AR小鼠中CCR3棕榈酰化升高，而CCR3敲除显著减轻了Th2炎症、CD34+细胞募集和鼻部症状。机制上，体外试验揭示IL-33/ST2轴直接驱动CCR3棕榈酰化，主要由棕榈酰转移酶ZDHHC-21介导。突变证实Cys298和Cys299是CCR3棕榈酰化的关键位点。至关重要的是，功能拯救实验表明，Cys298/299处的棕榈酰化是IL-33介导的嗜酸性粒细胞下游促炎介质（IL-13和CCL-2）释放所严格必需的。
结论： 本研究表明，CCR3在Cys298/299处的特异性棕榈酰化，由ZDHHC-21响应IL-33信号催化，是驱动AR中嗜酸性炎症的关键分子事件。尽管靶向这种脂质修饰提出了一种新的治疗策略，但CCR3棕榈酰化与其他鼻微环境因素之间的复杂相互作用，以及其可逆的去棕榈酰化动力学，仍有待未来研究充分阐明。

英文摘要

BACKGROUND: The post-translational modification of chemokine receptors plays a vital role in immune regulation, yet the specific role of CCR3 palmitoylation in allergic rhinitis (AR) remains elusive.
OBJECTIVE: This study aims to investigate the bioinformatic signatures of AR and elucidate the underlying molecular mechanisms of CCR3 palmitoylation in AR.
METHODS: An integrated bioinformatics approach, utilizing seven machine learning algorithms and Gene Set Enrichment Analysis (GSEA), was employed to identify key transcriptomic signatures and pathways in AR. In vivo, an allergen-induced AR model was established using wild-type and CCR3 knockout mice to evaluate histopathology, Th2 cytokine profiles, and CD34+ cell infiltration. The acyl-biotin exchange (ABE) assay was utilized to quantify CCR3 palmitoylation levels. In vitro, primary bone marrow-derived eosinophils (BM-Eos) were utilized to explore the upstream drivers of CCR3 palmitoylation. siRNA knockdown, site-directed mutagenesis, and genetic rescue experiments were conducted to confirm the specific palmitoyltransferases and modification sites.
RESULTS: Bioinformatics screening identified lipid metabolism/palmitoylation and the IL-33/CD34 axis as key pathways in AR. In vivo experiments confirmed elevated CCR3 palmitoylation in AR mice, while CCR3 KO significantly alleviated Th2 inflammation, CD34+ cell recruitment, and nasal symptoms. Mechanistically, in vitro assays revealed that the IL-33/ST2 axis directly drives CCR3 palmitoylation, predominantly mediated by the palmitoyltransferase ZDHHC-21. Mutagenesis confirmed that Cys298 and Cys299 are the critical sites for CCR3 palmitoylation. Crucially, functional rescue experiments demonstrated that palmitoylation at Cys298/299 is strictly required for IL-33-mediated release of downstream pro-inflammatory mediators (IL-13 and CCL-2) in eosinophils.
CONCLUSION: This study demonstrates that the specific palmitoylation of CCR3 at Cys298/299, catalyzed by ZDHHC-21 in response to IL-33 signaling, is a critical molecular event driving eosinophilic inflammation in AR. Although targeting this lipid modification presents a novel therapeutic strategy, the complex interplay between CCR3 palmitoylation and other nasal microenvironmental factors, as well as its reversible de-palmitoylation dynamics, remain to be fully elucidated in future studies.