研究人员表示，微生物群有助于免疫系统的发育和成熟。为了应对共生细菌，肠道CD4+T淋巴细胞分化为具有调节或效应功能的亚型。共同表达CD4和CD8αα同源二聚体（CD4IEL）的小肠上皮内淋巴细胞的发育取决于微生物群。然而，能够分化成CD4IEL的CD4+T细胞所识别的微生物抗原身份仍然未知。
研究人员发现β-己糖胺酶是一种跨拟杆菌门共生菌的保守酶，是CD4IEL分化的驱动因素。在小鼠结肠炎模型中，β-己糖胺酶特异性淋巴细胞对肠道炎症有保护作用。因此，单一特异性的T细胞可以识别各种丰富的共生菌，并在肠道粘膜上引起调节性免疫反应。
附：英文原文
Title: A conserved Bacteroidetes antigen induces anti-inflammatory intestinal T lymphocytes
Author: Djenet Bousbaine, Laura I. Fisch, Mariya London, Preksha Bhagchandani, Tiago B. Rezende de Castro, Mark Mimee, Scott Olesen, Bernardo S. Reis, David VanInsberghe, Juliana Bortolatto, Mathilde Poyet, Ross W. Cheloha, John Sidney, Jingjing Ling, Aaron Gupta, Timothy K. Lu, Alessandro Sette, Eric J. Alm, James J. Moon, Gabriel D. Victora, Daniel Mucida, Hidde L. Ploegh, Angelina M. Bilate
Issue&Volume: 2022-08-05
Abstract: The microbiome contributes to the development and maturation of the immune system. In response to commensal bacteria, intestinal CD4+ T lymphocytes differentiate into functional subtypes with regulatory or effector functions. The development of small intestine intraepithelial lymphocytes that coexpress CD4 and CD8αα homodimers (CD4IELs) depends on the microbiota. However, the identity of the microbial antigens recognized by CD4+ T cells that can differentiate into CD4IELs remains unknown. We identified β-hexosaminidase, a conserved enzyme across commensals of the Bacteroidetes phylum, as a driver of CD4IEL differentiation. In a mouse model of colitis, β-hexosaminidase–specific lymphocytes protected against intestinal inflammation. Thus, T cells of a single specificity can recognize a variety of abundant commensals and elicit a regulatory immune response at the intestinal mucosa.
DOI: abg5645
Source: https://www.science.org/doi/10.1126/science.abg5645