To understand functional role of PD‐1‐expressing MAIT cells during tuberculosis infection in humans, sorted PD‐1⁺ and PD‐1⁻ MAIT cells from pleural effusions of patients with pleural tuberculosis were subjected to transcriptome sequencing. PD‐1‐expressing MAIT cells were analysed by flow cytometry and their phenotypic and functional features were investigated. Transcriptome sequencing identified 144 genes that were differentially expressed between PD‐1⁺ and PD‐1⁻ MAIT cells from tuberculous pleural effusions and CXCL13 was the gene with highest fold difference. The level of PD‐1‐expressing MAIT cells was associated with extent of TB infection in humans. PD‐1‐expressing MAIT cells had increased production of CXCL13 and IL‐21 as determined by flow cytometry. PD‐1^highCXCR5⁻ MAIT cells were significantly expanded in pleural effusions from patients with pleural tuberculosis as compared with those from peripheral blood of both patients with tuberculosis and healthy controls. Although PD‐1^highCXCR5⁻ MAIT cells from tuberculous pleural effusions had reduced IFN‐γ level and increased expression of Tim‐3 and GITR, they showed activated phenotype and had higher glucose uptake and lipid content. It is concluded that PD‐1‐expressing MAIT cells had reduced IFN‐γ level but increased production of both CXCL13 and IL‐21.

中文翻译：

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来自肺结核患者的表达PD-1的MAIT细胞的CXCL13产量升高

为了解表达PD-1的MAIT细胞在人类结核感染中的功能作用，对来自胸膜结核患者胸腔积液的PD-1 ⁺和PD-1 ^- MAIT细胞进行了转录组测序。用流式细胞仪分析了表达PD-1的MAIT细胞，并研究了它们的表型和功能特征。转录组测序鉴定PD-1之间差异表达的是144个基因⁺和PD-1 ^-结核性胸腔积液和CXCL13的MAIT细胞是倍数差异最大的基因。表达PD-1的MAIT细胞的水平与人类结核病感染的程度有关。通过流式细胞术确定，表达PD-1的MAIT细胞的CXCL13和IL-21的产量增加。与结核病患者和健康人的外周血相比，胸膜结核患者的胸腔积液中PD-1^高CXCR5 ^- MAIT细胞显着扩增。虽然PD-1^高CXCR5 ^-结核性胸腔积液的MAIT细胞降低了IFN-γ水平，增加了Tim-3和GITR的表达，表现出活化的表型，并具有较高的葡萄糖摄取和脂质含量。结论是，表达PD-1的MAIT细胞降低了IFN-γ水平，但增加了CXCL13和IL-21的产量。