Mucosal-associated invariant T (MAIT) cells are an invariant T cell subset, which have been reported to play an antimicrobial role in infectious diseases. However, little is known about it in malignant diseases and tumors, especially in gastric cancer (GC). So in this study, we aim to examine the frequency, phenotype, partial functional capacity and clinical relevance of this cells from GC patients’ peripheral blood by flow cytometry. It was shown that the frequency of peripheral blood MAIT cells was negatively correlated with their increasing age in healthy adults. Importantly, comparing to the healthy controls (HC), the frequency and the absolute number of MAIT cells from GC patients’ peripheral blood with or without chemotherapy were both significantly lower than those. For the phenotype, the proportion of CD4−MAIT cell subset in GC patients without chemotherapy was lower than in HC, but higher than in GC patients with chemotherapy. Whereas, the proportion of CD4−CD8+MAIT cell subset in GC patients without chemotherapy was significantly lower than that in HC. Finally, the level of Granzyme-B (GrB), a molecule associated with MAIT cells was markedly lower in GC patients. But the correlation between the serum levels of GC-associated tumor antigens and the percentages of MAIT cells in GC patients was not observed. In conclusion, our study shows the decreased frequency, changed phenotypes and partial potentially impaired function of MAIT cells in GC patients, suggesting a possible MAIT cell-based immunological surveillance of GC.

中文翻译：

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胃癌患者外周血黏膜相关不变性T细胞减少和血清Granzyme-B产生受损

粘膜相关的不变T（MAIT）细胞是不变的T细胞亚群，据报道在感染性疾病中起着抗菌作用。但是，对于恶性疾病和肿瘤，尤其是胃癌（GC）知之甚少。因此，在这项研究中，我们旨在通过流式细胞术检查来自GC患者外周血的这种细胞的频率，表型，部分功能能力和临床相关性。结果表明，在健康成年人中，外周血MAIT细胞的频率与其年龄的增长呈负相关。重要的是，与健康对照（HC）相比，GC患者外周血中有或没有化疗的MAIT细胞的频率和绝对数量均显着低于那些。对于表型，未经化疗的GC患者中CD4-MAIT细胞亚群的比例低于HC，但高于接受化疗的GC患者。相比之下，未经化疗的GC患者中CD4-CD8 + MAIT细胞亚群的比例显着低于HC患者。最后，GC患者中与MAIT细胞相关的分子Granzyme-B（GrB）的水平明显降低。但是，未观察到GC患者的血清GC相关肿瘤抗原水平与MAIT细胞百分比之间的相关性。总之，我们的研究表明GC患者MAIT细胞的频率降低，表型改变以及部分潜在的功能受损，提示可能存在基于MAIT细胞的GC免疫学监测。未经化疗的GC患者中CD4-CD8 + MAIT细胞亚群的比例显着低于HC患者。最后，GC患者中与MAIT细胞相关的分子Granzyme-B（GrB）的水平明显降低。但是，未观察到GC患者的血清GC相关肿瘤抗原水平与MAIT细胞百分比之间的相关性。总之，我们的研究表明GC患者MAIT细胞的频率降低，表型改变以及部分潜在的功能受损，提示可能存在基于MAIT细胞的GC免疫学监测。未经化疗的GC患者中CD4-CD8 + MAIT细胞亚群的比例显着低于HC患者。最后，GC患者中与MAIT细胞相关的分子Granzyme-B（GrB）的水平明显降低。但是，未观察到GC患者的血清GC相关肿瘤抗原水平与MAIT细胞百分比之间的相关性。总之，我们的研究表明GC患者MAIT细胞的频率降低，表型改变以及部分潜在的功能受损，提示可能存在基于MAIT细胞的GC免疫学监测。但是，未观察到GC患者的血清GC相关肿瘤抗原水平与MAIT细胞百分比之间的相关性。总之，我们的研究表明GC患者MAIT细胞的频率降低，表型改变以及部分潜在的功能受损，提示可能存在基于MAIT细胞的GC免疫学监测。但是，未观察到GC患者的血清GC相关肿瘤抗原水平与MAIT细胞百分比之间的相关性。总之，我们的研究表明GC患者MAIT细胞的频率降低，表型改变以及部分潜在的功能受损，提示可能存在基于MAIT细胞的GC免疫学监测。