Pulmonary Center, Boston University Chobanian & Avedesian School of Medicine, Boston, Massachusetts, USA; Department of Virology, Immunology, & Microbiology, Boston University Chobanian & Avedesian School of Medicine, Boston, Massachusetts, USA.
Pulmonary Center, Boston University Chobanian & Avedesian School of Medicine, Boston, Massachusetts, USA; Department. of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA.
Mucosal Immunol. 2023 Oct;16(5):699-710. doi: 10.1016/j.mucimm.2023.07.004. Epub 2023 Sep 14.
Streptococcus pneumoniae is the most common etiology of bacterial pneumonia, one of the leading causes of death in children and the elderly worldwide. During non-lethal infections with S. pneumoniae, lymphocytes accumulate in the lungs and protect against reinfection with serotype-mismatched strains. Cluster of differentiation CD4 resident memory T (T) cells are known to be crucial for this protection, but the diversity of lung CD4 T cells has yet to be fully delineated. We aimed to identify unique subsets and their contributions to lung immunity. After recovery from pneumococcal infections, we identified a distinct subset of CD4 T cells defined by the phenotype CD11aCD69GL7 in mouse lungs. Phenotypic analyses for markers of lymphocyte memory and residence demonstrated that GL7 T cells are a subset of CD4 T cells. Functional studies revealed that unlike GL7 T subsets that were mostly (RAR-related Orphan Receptor gamma T) RORγT, GL7 T cells exhibited higher levels of (T-box expressed in T cells) T-bet and Gata-3, corresponding with increased synthesis of interferon-γ, interleukin-13, and interleukin-5, inherent to both T helper 1 (T1) and T2 functions. Thus, we propose that these cells provide novel contributions during pneumococcal pneumonia, serving as important determinants of lung immunity.
肺炎链球菌是细菌性肺炎最常见的病因，也是全球儿童和老年人死亡的主要原因之一。在非致死性肺炎链球菌感染中，淋巴细胞在肺部积聚，可防止与血清型不同的菌株再次感染。已知分化群 CD4 驻留记忆 T（T）细胞对于这种保护至关重要，但肺部 CD4 T 细胞的多样性尚未完全描绘。我们旨在确定独特的亚群及其对肺部免疫的贡献。在从肺炎球菌感染中恢复后，我们在小鼠肺部确定了一种独特的 CD4 T 细胞亚群，其表型为 CD11aCD69GL7。用于淋巴细胞记忆和驻留标记的表型分析表明，GL7 T 细胞是 CD4 T 细胞的一个亚群。功能研究表明，与主要为（RAR 相关孤儿受体 γ T）RORγT 的 GL7 T 亚群不同，GL7 T 细胞表现出更高水平的（T 细胞中表达的 T 框）T-bet 和 Gata-3，对应于干扰素-γ、白细胞介素-13 和白细胞介素-5 的合成增加，这与 T 辅助 1（T1）和 T2 功能都有关。因此，我们提出这些细胞在肺炎球菌性肺炎中提供新的贡献，是肺部免疫的重要决定因素。
