Role of B cell interactions in CNS autoimmune demyelination

PRJOECT摘要 多发性硬化(MS)是一种免疫介导的中枢神经系统脱髓鞘疾病 系统(CNS)，通过该系统渗透自身反应克隆，并具有其他促炎细胞类型 他们招募和支持，致力于摧毁神经元周围的保护性髓鞘。这 导致神经传导受损和无数的病理，包括疼痛，视力丧失， 认知缺陷，以及最终瘫痪。它目前是无法治愈的。因为它的生命开始得很早 (通常在第三或第四个十年)，并随着时间的推移逐渐恶化，MS 诊断悲剧性地宣判患者进行一场旷日持久的斗争，代表着一种重要的健康和 近100万美国人的经济负担。了解复杂的免疫细胞相互作用 控制疾病的发病和调节是发现新的治疗方法的关键 对病人来说。MS小鼠实验性自身免疫性脑脊髓炎(EAE)模型 对这些过程提供了很好的见解，并专注于CD4T细胞(CD4)，它可以 过继将瘫痪转移到健康小鼠身上。B细胞和CD8 T细胞(CD8)的作用 相比之下，人们对此的研究还不够深入。最近的MS临床试验中靶向B细胞去除的成功 重新引起了人们对这些细胞在脱髓鞘疾病中所起作用的强烈兴趣。然而，大多数 EAE模型不考虑致病的B细胞，其中髓鞘多肽诱导的模型(例如。 MOG35-55)在缺乏B的小鼠中表现出EAE。全长重组人MOG(HMOG)蛋白 诱导依赖B细胞的EAE，但其产生在生物化学上繁琐，耗时， 而且价格昂贵，这是对EAE中B细胞进行有效研究的障碍。 此外，MOG是一个次要成分，埋在髓鞘结构和啮齿动物的MOG中 与人MOG有残基差异，使其诱导的EAE B细胞不依赖。髓鞘 相比之下，蛋白脂蛋白(PLP)是最丰富的髓鞘蛋白，含有100%的氨基酸 小鼠与人的酸序列同源性。然而，与MOG35-55一样，PLP178-191诱导 B细胞非依赖性EAE。因此，我们设计了一种新型的包被细胞外的多肽 PLP的结构域，并发现它驱动一种强大的B细胞依赖的EAE。我们的团队已经 证实人外周血单核细胞中髓鞘特异性CD8具有调节功能 MS患者在抑制CD4细胞方面存在缺陷。此外，PLP178-191特异性CD8抑制EAE和 甚至可以消除小鼠的瘫痪。因此，B细胞与致病的CD4s相互作用并调节 CD8细胞(直接或通过TFH细胞)可以在我们的新模型中进行研究。这个由PLP驱动的B细胞- 在拟议的工作中将发展多发性硬化症的依赖小鼠模型，并且不仅将 该领域的技术能力，但为研究EAE中的B细胞提供了一个急需的舞台。

PRJOECT ABSTRACT Multiple sclerosis (MS) is an immune-mediated demyelinating disease of the central nervous system (CNS) whereby infiltrating autoreactive clones, with additional pro-inflammatory cell types they recruit and support, work to destroy the protective myelin sheaths surrounding neurons. This results in compromised nerve conduction and myriad pathologies including pain, vision loss, cognitive deficits, and eventual paralysis. It is currently incurable. Due to its early life onset (typically in the third or fourth decade) and that it progressively worsens over time, an MS diagnosis tragically sentences patients to a prolonged battle, representing a significant health and financial burden for nearly 1 million Americans. Understanding the complex immune cell interplay governing pathogenesis and regulation of disease is critical for the discovery of novel therapeutics for patients. The MS mouse model experimental autoimmune encephalomyelitis (EAE) has provided great insights into these processes, and has focused on CD4 T cells (CD4s), which can adoptively transfer paralysis to healthy mice. The role of B cells and CD8 T cells (CD8s) have been understudied in comparison. Targeted B cell-depletion success in recent MS clinical trials has renewed intense interest in the role these cells play in demyelinating disease. However, most EAE models do not account for pathogenic B cells, where myelin peptide-induced models (eg. MOG35-55) exhibit EAE in B-less mice. Full-length recombinant human MOG (hMOG) protein induces B cell-dependent EAE but its production is biochemically cumbersome, time-consuming, and expensive, representing a barrier of access to efficient investigation of B cells in EAE. Additionally, MOG is a minor component and buried within the myelin structure and rodent MOG has residue differences with human MOG that render its induced EAE B cell-independent. Myelin proteolipid protein (PLP) in contrast is the most abundant myelin protein and shares 100% amino acid sequence homology between mouse and human. However, like MOG35-55, PLP178-191 induces B cell-independent EAE. We therefore designed a novel peptide encompassing the extracellular domains of PLP and have found that it drives a robust B cell-dependent EAE. Our group has demonstrated that myelin-specific CD8s in human PBMC have regulatory function and are defective at inhibiting CD4s in MS patients. Further, PLP178-191-specific CD8s suppress EAE and even eliminate paralysis in mice. Thus, B cell interactions with pathogenic CD4s and regulatory CD8s (direct or through TFH cells) can be studied in our novel model. This PLP-driven, B cell- dependent murine model of MS will be developed in the proposed work, and will not only advance the field’s technical capability, but serve as a much-needed arena for investigating B cells in EAE.