Modulation of Neutrophilic Inflammation in Rheumatoid Arthritis by Autoantibody Glycosylation

嗜中性粒细胞介导的应答可由类风湿性关节炎（RA）期间产生的自身抗体引起，例如抗瓜氨酸肽抗体（ACPA），其形成免疫复合物（IC）。虽然ACPA的存在包括在诊断RA的标准中，但ACPA阳性个体可能患有RA，保持健康或将发展为RA。免疫球蛋白G（IgG）抗体（包括ACPA）Fc结构域上的某些糖基化模式可能在RA发作前数月发生变化，与促炎反应增加和发生RA的可能性增加相关。此外，妊娠或RA治疗与较低的RA病理学相关，这与IgG糖基化模式的变化相关。本项目将研究促炎和抗炎中性粒细胞功能，以响应由含有“健康”或RA典型糖基化谱的IgG组成的IC刺激，其基于特定IgG糖基化模式更具促炎性，促进增强的促炎性作用的假设。（或减少的抗炎）中性粒细胞反应，这可能促进RA。为了检验这一假设，该项目将鉴定健康个体和受自身免疫性疾病影响的个体的典型IgG糖基化模式（例如，RA、狼疮、多发性硬化）。一旦确定了模式，将对细胞系进行工程改造，以表达具有确定的糖基化模式的人IgG，并产生“健康”和“促炎”IC。将用这些IC刺激从健康献血者中分离的中性粒细胞，并分析促炎和抗炎中性粒细胞反应。

Neutrophil-mediated responses can be elicited by autoantibodies produced during rheumatoid arthritis (RA), such as anti-citrullinated peptide antibodies (ACPA), which form immune complexes (ICs). Although the presence of ACPA is included in the criteria for diagnosing RA, ACPA-positive individuals may have RA, remain healthy or will develop RA. Certain glycosylation patterns on the Fc domain of immunoglobulin G (IgG) antibodies, including ACPAs, can change months prior to RA onset, correlating to increased pro-inflammatory responses and increased likelihood to develop RA. Furthermore, pregnancy or RA treatment are associated with lower RA pathology which correlate with changes in IgG glycosylation patterns. This project will investigate pro- and anti-inflammatory neutrophil functions in response to stimulation with ICs consisting of IgG containing 'healthy' or RA-typical glycosylation profiles based on the hypothesis that particular IgG glycosylation patterns are more pro-inflammatory, promoting enhanced pro-inflammatory (or reduced anti-inflammatory) neutrophil responses which may promote RA.To test this hypothesis, this project will identify typical IgG glycosylation patterns of healthy individuals and those affected by autoimmune diseases (e.g., RA, lupus, multiple sclerosis) using existing literature and databases. Once the patterns are determined, cell lines will be engineered to express human IgGs with the determined glycosylation patterns and for the generation of 'healthy' and 'pro-inflammatory' ICs. Neutrophils isolated from healthy blood donors will be stimulated with these ICs, and pro-inflammatory and anti-inflammatory neutrophil responses will be analysed.