Medical Microbiology Interdisciplinary Program, Graduate School, Chulalongkorn University, Bangkok, Thailand.
Immunology Division, Faculty of Medicine, Department of Microbiology, Chulalongkorn University, Bangkok, Thailand.
J Leukoc Biol. 2022 Oct;112(4):717-732. doi: 10.1002/JLB.4A0421-223RR. Epub 2022 Jun 15.
Mucosal-associated invariant T (MAIT) cells are innate-like, unconventional T cells that are present in peripheral blood and mucosal surfaces. A clear understanding of how MAIT cells in the mucosae function and their role in host immunity is still lacking. Therefore, our aim was to investigate MAIT cell distribution and their characteristics in the gastrointestinal (GI) mucosal tissue based on Vα7.2 CD161 identification. We showed that Vα7.2 CD161 T cells are present in both intraepithelial layer and lamina propriae of the GI mucosa, but have different abundance at each GI site. Vα7.2 CD161 T cells were most abundant in the duodenum, but had the lowest reactivity to MR1-5-OP-RU tetramers when compared with Vα7.2 CD161 T cells at other GI tissue sites. Striking discrepancies between MR1-5-OP-RU tetramer reactive cells and Vα7.2 CD161 T cells were observed along each GI tissue sites. Vα7.2 CD161 TCR repertoire was most diverse in the ileum. Similar dominant profiles of TRBV usage were observed among peripheral blood, duodenum, ileum, and colon. Some TRBV chains were detected at certain intestinal sites and not elsewhere. The frequency of peripheral blood Vα7.2 CD161 T cells correlated with mucosal Vα7.2 CD161 T cells in lamina propriae ileum and lamina propriae colon. The frequency of peripheral blood Vα7.2 CD161 T cells in Helicobacter pylori-infected individuals was significantly lower than uninfected individuals, but this was not observed with gastric Vα7.2 CD161 T cells. This study illustrates the biology of Vα7.2 CD161 T cells in the GI mucosa and provides a basis for understanding MAIT cells in the mucosa and MAIT-related GI diseases.
黏膜相关不变 T（MAIT）细胞是先天样的非常规 T 细胞，存在于外周血和黏膜表面。目前仍然缺乏对黏膜 MAIT 细胞功能及其在宿主免疫中的作用的清晰认识。因此，我们的目的是基于 Vα7.2 CD161 鉴定来研究 GI 黏膜组织中 MAIT 细胞的分布及其特征。我们表明，Vα7.2 CD161 T 细胞存在于 GI 黏膜的上皮内层和固有层中，但在每个 GI 部位的丰度不同。Vα7.2 CD161 T 细胞在十二指肠中最为丰富，但与其他 GI 组织部位的 Vα7.2 CD161 T 细胞相比，对 MR1-5-OP-RU 四聚体的反应性最低。在每个 GI 组织部位都观察到 MR1-5-OP-RU 四聚体反应性细胞与 Vα7.2 CD161 T 细胞之间存在显著差异。在回肠中，Vα7.2 CD161 TCR 库的多样性最大。在外周血、十二指肠、回肠和结肠中观察到相似的 TRBV 利用优势谱。某些 TRBV 链仅在某些肠道部位检测到，而在其他部位未检测到。外周血 Vα7.2 CD161 T 细胞的频率与回肠固有层和结肠固有层黏膜 Vα7.2 CD161 T 细胞相关。幽门螺杆菌感染个体外周血 Vα7.2 CD161 T 细胞的频率明显低于未感染者，但在胃 Vα7.2 CD161 T 细胞中未观察到这种情况。本研究阐明了 GI 黏膜中 Vα7.2 CD161 T 细胞的生物学特性，为理解黏膜 MAIT 细胞和 MAIT 相关的 GI 疾病提供了基础。
