Luís Almeida, Alice Bacon, Mohan Ghorasaini, Alwin J. van der Ham, René E. M. Toes, Martin Giera, Bart Everts
{"title":"IgA2 ACPA Drives a Hyper-Inflammatory Phenotype in Macrophages via ATP Synthase and COX2","authors":"Luís Almeida, Alice Bacon, Mohan Ghorasaini, Alwin J. van der Ham, René E. M. Toes, Martin Giera, Bart Everts","doi":"10.1002/eji.202451586","DOIUrl":null,"url":null,"abstract":"<p>IgA can form immune complexes (ICs) and activate myeloid cells via Fc alpha receptor-mediated signalling to secrete pro-inflammatory cytokines. It was previously described that of the two IgA subclasses (IgA1 and IgA2), IgA2 is more inflammatory than IgA1. However, the mechanisms underlying this differential pro-inflammatory potential remain poorly defined. Using anti-citrullinated protein IgA1 and IgA2 antibodies (ACPA) that are commonly found in rheumatoid arthritis (RA) patients and linked to chronic inflammation, we show here that, in macrophages, IgA2-ICs boost TLR-induced TNF and IL6 secretion, COX2 expression, and production of COX2-dependent lipid mediators to a higher level than IgA1-ICs. Metabolically, we found the amplification of TLR-induced cytokine production and COX2 induction by IgA2-ICs to be dependent on mitochondrial ATP synthesis, but not glycolysis. Finally, we found the potentiation of TLR-induced cytokine production by IgA-ICs to be COX2-dependent. Together this work points towards a key role for mitochondrial ATP synthesis in driving COX2 expression and subsequent IgA2-IC-dependent potentiation of TLR-induced cytokine production by macrophages. As such, our work provides new insights into the mechanisms underlying IgA2-induced inflammation in the context of RA. Thus, this may hold novel clues to be explored as therapeutic possibilities to target antibody-driven inflammation in chronic inflammatory diseases.</p>","PeriodicalId":165,"journal":{"name":"European Journal of Immunology","volume":"55 4","pages":""},"PeriodicalIF":4.5000,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/eji.202451586","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"European Journal of Immunology","FirstCategoryId":"3","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/eji.202451586","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"IMMUNOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
IgA can form immune complexes (ICs) and activate myeloid cells via Fc alpha receptor-mediated signalling to secrete pro-inflammatory cytokines. It was previously described that of the two IgA subclasses (IgA1 and IgA2), IgA2 is more inflammatory than IgA1. However, the mechanisms underlying this differential pro-inflammatory potential remain poorly defined. Using anti-citrullinated protein IgA1 and IgA2 antibodies (ACPA) that are commonly found in rheumatoid arthritis (RA) patients and linked to chronic inflammation, we show here that, in macrophages, IgA2-ICs boost TLR-induced TNF and IL6 secretion, COX2 expression, and production of COX2-dependent lipid mediators to a higher level than IgA1-ICs. Metabolically, we found the amplification of TLR-induced cytokine production and COX2 induction by IgA2-ICs to be dependent on mitochondrial ATP synthesis, but not glycolysis. Finally, we found the potentiation of TLR-induced cytokine production by IgA-ICs to be COX2-dependent. Together this work points towards a key role for mitochondrial ATP synthesis in driving COX2 expression and subsequent IgA2-IC-dependent potentiation of TLR-induced cytokine production by macrophages. As such, our work provides new insights into the mechanisms underlying IgA2-induced inflammation in the context of RA. Thus, this may hold novel clues to be explored as therapeutic possibilities to target antibody-driven inflammation in chronic inflammatory diseases.
期刊介绍:
The European Journal of Immunology (EJI) is an official journal of EFIS. Established in 1971, EJI continues to serve the needs of the global immunology community covering basic, translational and clinical research, ranging from adaptive and innate immunity through to vaccines and immunotherapy, cancer, autoimmunity, allergy and more. Mechanistic insights and thought-provoking immunological findings are of interest, as are studies using the latest omics technologies. We offer fast track review for competitive situations, including recently scooped papers, format free submission, transparent and fair peer review and more as detailed in our policies.