S-Geranylgeranyl-L-glutathione is a ligand for human B cell-confinement receptor P2RY8
S-Geranylgeranyl-L-glutathione is a ligand for human B cell-confinement receptor P2RY8
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DOI：
10.1038/s41586-019-1003-z
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发表时间：
2019-03-14
期刊：
影响因子：
64.8
通讯作者：
Cyster, Jason G.
中科院分区：
文献类型：
--
作者：
Lu, Erick;Wolfreys, Finn D.;Cyster, Jason G.
生发中心是抗体多样化和亲和力成熟的重要场所，也是 B 细胞恶性肿瘤的常见起源。尽管生发中心由运动细胞组成，但它被严格限制在 B 细胞滤泡内。促进这种限制的线索尚不完全清楚。 P2RY8 是一种 G α(13) 偶联受体，可介导迁移抑制并调节淋巴组织中 B 细胞的生长(1,2)。 P2RY8 在生发中心 B 细胞样弥漫性大 B 细胞淋巴瘤 (GCB-DLBCL) 和伯基特淋巴瘤 (1,3-6) 中经常发生突变，并且该受体的配体尚未确定。在这里，我们对 P2RY8 配体进行了搜索，并在胆汁以及几种小鼠和人类细胞系的培养上清液中发现了 P2RY8 生物活性。使用七步生化分级分离程序和辍学质谱方法，我们证明了一种先前未描述的生物分子，S-香叶基香叶基-l-谷胱甘肽（GGG），是一种有效的 P2RY8 配体，可在纳摩尔水平的淋巴组织中检测到。 GGG 抑制趋化因子介导的人生发中心 B 细胞和滤泡辅助 T 细胞的迁移，并拮抗生发中心 B 细胞中磷酸化 AKT 的诱导。我们还发现，滤泡树突状细胞高表达的γ-谷氨酰转移酶-5 (GGT5) 将 GGG 代谢为不激活受体的形式。 GGT5 的过度表达破坏了 P2RY8 促进 B 细胞限制于生发中心的能力，这表明 GGT5 在淋巴组织中建立了 GGG 梯度。这项工作将 GGG 定义为一种参与组织和控制生发中心反应的细胞间信号分子。由于 P2RY8 基因座在除 GCB-DLBCL 和伯基特淋巴瘤之外的几种其他类型的癌症中发生修饰，我们推测 GGG 可能在多种人体组织中具有组织和生长调节作用。
Germinal centres are important sites for antibody diversification and affinity maturation, and are also a common origin of B cell malignancies. Despite being made up of motile cells, germinal centres are tightly confined within B cell follicles. The cues that promote this confinement are incompletely understood. P2RY8 is a G alpha(13)-coupled receptor that mediates the inhibition of migration and regulates the growth of B cells in lymphoid tissues(1,2). P2RY8 is frequently mutated in germinal-centre B cell-like diffuse large B cell lymphoma (GCB-DLBCL) and Burkitt lymphoma(1,3-6), and the ligand for this receptor has not yet been identified. Here we perform a search for P2RY8 ligands and find P2RY8 bioactivity in bile and in culture supernatants of several mouse and human cell lines. Using a seven-step biochemical fractionation procedure and a drop-out mass spectrometry approach, we show that a previously undescribed biomolecule, S-geranylgeranyl-l-glutathione (GGG), is a potent P2RY8 ligand that is detectable in lymphoid tissues at the nanomolar level. GGG inhibited the chemokine-mediated migration of human germinal-centre B cells and T follicular helper cells, and antagonized the induction of phosphorylated AKT in germinal-centre B cells. We also found that the enzyme gamma-glutamyltransferase-5 (GGT5), which was highly expressed by follicular dendritic cells, metabolized GGG to a form that did not activate the receptor. Overexpression of GGT5 disrupted the ability of P2RY8 to promote B cell confinement to germinal centres, which indicates that GGT5 establishes a GGG gradient in lymphoid tissues. This work defines GGG as an intercellular signalling molecule that is involved in organizing and controlling germinal-centre responses. As the P2RY8 locus is modified in several other types of cancer in addition to GCB-DLBCL and Burkitt lymphoma, we speculate that GGG might have organizing and growth-regulatory roles in multiple human tissues.