Targeting follicular helper CD4 T cells in SLE

项目总结/摘要 高亲和力类别转换自身抗体（autoAb）是狼疮的主要致病效应分子。他们 由B细胞产生，B细胞通过生发中心（GC）或滤泡外（EF）分化 途径。狼疮患者滤泡辅助（Tfh）细胞和EF辅助（eTf）CD 4 + T细胞的频率增加 与疾病活动直接相关。EF通路在MRL/lpr狼疮中得到了最好的表征- 具有AM 14 BCR Tg B细胞的易感小鼠，其已被用作自身反应性B细胞活化的模型 通过双BCR和TLR 9信号。总的来说，GC和EF途径是狼疮发病机制的关键节点 和狼疮易感小鼠为这些途径的机制研究提供了经过验证的模型。我们和其他人已经 表明狼疮患者和小鼠的免疫细胞的代谢发生了改变，其中一些 改变提供了治疗目标。相对而言，我们对维持这两种状态的代谢程序知之甚少。 自身反应性或免疫诱导的（Imm-）GC B细胞和Tfh细胞，并且关于这些细胞的免疫调节作用还一无所知。 EF激活代谢。我们在第一轮资助中已经证明， IgG而非Imm-Ab具有葡萄糖依赖性。相比之下，autoAb和Imm-Ab均被免疫抑制剂消除。 抑制组胺的分解。这些结果是用代谢产物处理的大量多克隆群体获得的。 因此，抑制剂使我们假设autoAb和Imm-Ab具有不同的代谢要求， GC阶段，这最终可以转化为它们的选择性靶向。在这次竞争性的更新中，我们 建议使用自身和Imm-Ig特异性B和T细胞，以及GC B和Tact特异性代谢缺失， 酶，以确定自身反应性和Imm-GC B和Tfh细胞的内在代谢要求， 抗原和细胞特异性水平。我们还建议解决EF激活的代谢要求， 自身反应性B细胞。使用独特的小鼠模型以及scRNA-Seq和深层代谢组学的组合， 分析，我们提出了三个具体目标，以确定葡萄糖（1），谷氨酰胺（2）， 粮农组织（3）为autoAb与Imm-Ab生产，并确定相应的机制。这些 实验将有助于确定参与免疫调节的B和CD 4 + T细胞的特定代谢要求。 狼疮自身抗体的产生。这些知识可能最终确定消除自身抗体产生的方法 同时保留保护性体液自身免疫。

Project Summary/Abstract High affinity class-switched autoantibodies (autoAb) are the major pathogenic effector molecules in lupus. They are generated by B cells that differentiate through either the germinal center (GC) or the extrafollicular (EF) pathways. The frequency of follicular helper (Tfh) cells and EF helper (eTf) CD4+ T cells are expanded in lupus in direct correlation with disease activity. The EF pathway has been best characterized in the MRL/lpr lupus- prone mice with AM14 BCR Tg B cells, which have been used as a model of autoreactive B cells activated through dual BCR and TLR9 signals. Overall, the GC and EF pathways are crucial nodes of lupus pathogenesis and lupus-prone mice present validated models for mechanistic studies of these pathways. We and others have shown that the metabolism of immune cells was altered in lupus patients and mice, and that some of these alterations offer therapeutic targets. Relatively little is known on the metabolic programs that sustain either autoreactive or immunization-induced (Imm-) GC B cells and Tfh cells, and nothing is known about the metabolism of EF activation. We have shown during the first cycle of funding that the production of anti-dsDNA IgG but not Imm-Abs, was glucose-dependent. In contrast, both autoAbs and Imm-Abs were eliminated by the inhibition of glutaminolysis. These results obtained with bulk polyclonal populations treated with metabolic inhibitors his led us to hypothesize that autoAbs and Imm-Abs have different metabolic requirements through the GC stage, which could be ultimately translated in their selective targeting. In this competitive renewal, we propose to use auto- and Imm-Ig-specific B and T cells, as well as GC B and Tact-specific deletions of metabolic enzymes to determine the intrinsic metabolic requirements of autoreactive and Imm-GC B and Tfh cells at the antigen- and cell-specific levels. We also propose to address the metabolic requirements of EF activation of autoreactive B cells. Using unique mouse models and a combination of scRNA-Seq and deep metabolomic analyses, we propose three specific aims to determine the requirements in glucose (1), glutamine (2), and FAO (3) for autoAb vs. Imm-Ab production, and to identify the corresponding mechanisms. These experiments will help to define the specific metabolic requirements of the B and CD4+ T cells that participate in the production of lupus autoAbs. This knowledge may ultimately identify means to eliminate autoAb production while preserving protective humoral autoimmunity.