AbstractBackgroundUrinary tract infection recurrence is common, particularly in women and immunocompromised patients, such as renal transplant recipients (RTRs). Mucosal‐associated invariant T (MAIT) cells play a role in the antibacterial response by recognizing bacterial riboflavin metabolites produced by bacteria such as Escherichia coli. Here, we investigated whether MAIT cells are involved in the pathogenesis of recurrent urinary tract infections (RUTIs).MethodsUsing multichannel flow cytometry, we characterized the MAIT cell phenotype and function in blood from immunocompetent adults with (n = 13) and without RUTIs (n = 10) and in RTRs with (n = 9) and without RUTIs (n = 10).ResultsThere were no differences in the numbers of MAIT cells between the study groups. MAIT cells in patients with RUTI expressed T‐bet more often than those in controls. MAIT cells from immunocompetent RUTI participants required more antigen‐presenting cells coincubated with E. coli to evoke a similar cytokine and degranulation response than those from controls. This effect was absent in the RTR with RUTI vs RTR control groups, where the overall percentage of MAIT cells that responded to stimulation was already reduced.ConclusionCirculating MAIT cells in immunocompetent individuals with RUTIs respond to bacterial stimuli with reduced efficacy, which suggests that they are involved in the pathogenesis of RUTIs.

中文翻译：

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复发性尿路感染受试者的循环粘膜相关不变 T 细胞功能受损

摘要背景尿路感染复发很常见，特别是在女性和免疫功能低下的患者中，例如肾移植受者（RTR）。粘膜相关不变 T (MAIT) 细胞通过识别细菌产生的细菌核黄素代谢物，在抗菌反应中发挥作用，例如大肠杆菌。在这里，我们研究了 MAIT 细胞是否参与复发性尿路感染 (RUTI) 的发病机制。方法使用多通道流式细胞术，我们对具有 RUTI 的免疫活性成人 (n = 13) 和不具有 RUTI 的血液 (n = 10) 以及具有 RUTI 的 RTR (n = 9) 和不具有 RUTI 的 RTR (n = 10) 的血液中的 MAIT 细胞表型和功能进行了表征。结果研究组之间的 MAIT 细胞数量没有差异。RUTI 患者的 MAIT 细胞比对照组更频繁地表达 T-bet。来自免疫活性 RUTI 参与者的 MAIT 细胞需要更多的抗原呈递细胞大肠杆菌引起与对照组相似的细胞因子和脱颗粒反应。与 RTR 对照组相比，使用 RUTI 的 RTR 组中不存在这种效应，其中对刺激做出反应的 MAIT 细胞的总体百分比已经降低。结论患有 RUTI 的免疫功能正常个体中的循环 MAIT 细胞对细菌刺激的反应效率降低，这表明它们参与了 RUTI 的发病机制。