The field of tissue‐resident B cells has received increasing attention, yet the feature of tissue B cells in respiratory system is unclear. Here, we first show that non‐circulating B cells obtained from nasal, trachea and lung tissues are numerically and phenotypically distinct from their circulating counterparts. Analysis of single cell transcriptome sequence identified multiple differentially expressed genes between non‐circulating B cells and circulating B cells, which illustrated their heterogeneity. Furthermore, we found high expression of CXCR3 on non‐circulating B cells, and the chemokine CXCL11 was also up‐regulated in the respiratory tissues, suggesting that CXCR3‐CXCL11 axis might accelerate the local resident of non‐circulating B cells in respiratory tract. Interestingly, intranasal immunization with BCG in mice elicited a sustained humoral immune response via induction of IgA and IgG Abs, which revealed the role of B cells. Meanwhile, tissue‐resident B cells, IgA⁺ and IgG⁺ memory B cells (MBCs) in respiratory tissues, as well as plasma cells in bone marrow, were expanded and maintained, and these subsets probably developed into antibody‐producing cells to participate in the local humoral immunity. Our data illustrate the phenotype and function of tissue B cells in the upper and lower airways, provide references for the prospective development of vaccines.

中文翻译：

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呼吸系统组织B细胞的表型和功能研究为疾病和疫苗开发提供了重要信息

组织驻留B细胞领域越来越受到关注，但组织B细胞在呼吸系统中的特征尚不清楚。在这里，我们首先表明从鼻、气管和肺组织获得的非循环 B 细胞在数量和表型上与其循环对应物不同。单细胞转录组序列分析确定了非循环 B 细胞和循环 B 细胞之间的多个差异表达基因，这说明了它们的异质性。此外，我们发现 CXCR3 在非循环 B 细胞上高表达，趋化因子 CXCL11 在呼吸组织中也上调，表明 CXCR3-CXCL11 轴可能加速非循环 B 细胞在呼吸道中的局部驻留。有趣的是，在小鼠中用卡介苗进行鼻内免疫通过诱导 IgA 和 IgG Abs 引发持续的体液免疫反应，这揭示了 B 细胞的作用。同时，组织驻留 B 细胞 IgA呼吸组织中的⁺和 IgG ⁺记忆 B 细胞 (MBC) 以及骨髓中的浆细胞得到扩增和维持，这些亚群可能发展成为产生抗体的细胞参与局部体液免疫。我们的数据说明了上呼吸道和下呼吸道组织B细胞的表型和功能，为疫苗的前瞻性开发提供参考。