美国华盛顿大学Oliver J. Harrison研究组发现，噬菌体展示筛选与B细胞四聚体相结合可在抗原水平分辨率水平揭示共生特异性B细胞反应。相关论文于2024年5月8日在线发表在《免疫》杂志上。

通过噬菌体展示，研究人员确定了血清和肠道抗体靶向的分节丝状菌（SFB）抗原，并生成了B细胞四聚体，以追踪肠道相关淋巴组织中的SFB特异性B细胞。

研究人员发现了SFB特异性B细胞活化过程中的分区反应，免疫球蛋白A（IgA）、IgG1和IgG2b亚型沿着派伊尔结梯度产生，而肠系膜淋巴结内则选择性地产生IgG2b。V(D)J测序和单克隆抗体的产生确定了在平衡条件下，由体细胞超突变驱动的对SFB抗原的亲和性成熟。

将噬菌体展示与B细胞四聚体相结合，将有助于研究组织免疫、炎症和修复中共生特异性B细胞反应的个体发育和功能。

据悉，诱导共生特异性免疫有助于组织稳态，然而诱导共生特异性B细胞的机制仍然鲜为人知，部分原因是缺乏识别这些细胞的工具。

附：英文原文

Title: Antigen-level resolution of commensal-specific B cell responses can be enabled by phage display screening coupled with B cell tetramers

Author: Sheenam Verma, Matthew J. Dufort, Tayla M. Olsen, Samantha Kimmel, Jasmine C. Labuda, Sam Scharffenberger, Andrew T. McGuire, Oliver J. Harrison

Issue&Volume: 2024-05-08

Abstract: Induction of commensal-specific immunity contributes to tissue homeostasis, yet themechanisms underlying induction of commensal-specific B cells remain poorly understoodin part due to a lack of tools to identify these cells. Using phage display, we identifiedsegmented filamentous bacteria (SFB) antigens targeted by serum and intestinal antibodiesand generated B cell tetramers to track SFB-specific B cells in gut-associated lymphoidtissues. We revealed a compartmentalized response in SFB-specific B cell activation,with a gradient of immunoglobulin A (IgA), IgG1, and IgG2b isotype production alongPeyer’s patches contrasted by selective production of IgG2b within mesenteric lymphnodes. V(D)J sequencing and monoclonal antibody generation identified somatic hypermutationdriven affinity maturation to SFB antigens under homeostatic conditions. Combiningphage display and B cell tetramers will enable investigation of the ontogeny and functionof commensal-specific B cell responses in tissue immunity, inflammation, and repair.

DOI: 10.1016/j.immuni.2024.04.014

Source: https://www.cell.com/immunity/abstract/S1074-7613(24)00219-X