作者：Gracey E, et al.
结果：与HCs相比，AS患者血中MAIT细胞减少，但IL-17A + MAIT细胞比率升高。在AS关节液中MAIT细胞富集，且IL-17水平升高。AS患者MAIT细胞IL-17水平升高与IL-7的诱导有关，而与IL-23或抗原刺激无关。在该研究中，与AS相关的IL7R基因单核苷酸多态性（SNP），位点rs11742270，对IL-7R的表达无影响。
附原文：OBJECTIVE: Ankylosing spondylitis (AS) is a chronic inflammatory disease of unknown origin in which interleukin (IL) 17 has been genetically and therapeutically recognised as a key player. Identification of the cellular sources and inducers of IL-17 is crucial in our understanding of the drivers of inflammation in AS. Recently, mucosal-associated invariant T (MAIT) cells have been implicated in autoimmune diseases. Their gut origin, effector phenotype and expression of multiple AS-associated genes, such as IL7R and IL23R, makes them potential contributors to the pathogenesis of AS.METHODS: Mononuclear cells from patients with AS, healthy controls (HCs) and patients with rheumatoid arthritis were isolated from blood and synovial fluid (SF). Flow cytometry was used to identify MAIT cells. Phenotype was assessed by intracellular staining for cytokines and granzyme. Function was assessed by antigen-specific stimulation using Salmonella, or antigen non-specific activation via priming with IL-7 or IL-23. RESULTS: MAIT cells were reduced in frequency in the blood of patients with AS compared with HCs, yet patients with AS had an elevated frequency IL-17A+ MAIT cells. There was an enrichment of MAIT cells in SF, which had an exaggerated IL-17 phenotype. IL-17 elevation in AS MAIT cells was dependent on priming with IL-7 but not IL-23 or antigen stimulation. The AS-associated IL7R single nucleotide polymorphism (SNP), rs11742270, had no effect on IL-7R expression or function in the experiments performed. CONCLUSIONS:This study reveals a potential role for MAIT cells in patients with AS and is the first linking IL-7 to the elevated IL-17 profile in patients through the AS-associated risk gene IL7R.
引自: Gracey E, Qaiyum Z, Almaghlouth I, et al.. IL-7 primes IL-17 in mucosal-associated invariant T (MAIT) cells, whichcontribute to the Th17-axis in ankylosing spondylitis. Ann Rheum Dis. 2016 May 10.