Role of B cell interactions in CNS autoimmune demyelination

产品简介 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），其中浸润自身反应性克隆，具有额外的促炎细胞类型 他们招募和支持，努力破坏神经元周围的保护性髓鞘。这 导致受损的神经传导和无数的病理，包括疼痛，视力丧失， 认知缺陷最终导致瘫痪目前无法治愈。由于其生命早期发病， （通常在第三或第四个十年），并随着时间的推移，它逐渐消失，MS 诊断悲惨地判决病人长期战斗，代表着一个重要的健康和 近100万美国人的经济负担。了解复杂的免疫细胞相互作用 控制疾病的发病机制和调节对于发现新的治疗方法至关重要 对患者MS小鼠模型实验性自身免疫性脑脊髓炎（EAE）具有 对这些过程提供了很好的见解，并专注于CD 4 T细胞（CD 4s），它可以 将麻痹转移到健康小鼠身上。B细胞和CD 8 T细胞（CD 8 s）的作用具有 相比之下被低估了。最近MS临床试验中靶向B细胞耗竭的成功 对这些细胞在脱髓鞘疾病中的作用重新产生了浓厚的兴趣。但大多数 EAE模型不能解释致病性B细胞，其中髓磷脂肽诱导的模型（例如， MOG 35 -55）在B-少小鼠中表现出EAE。全长重组人MOG（hMOG）蛋白 诱导B细胞依赖性EAE，但其产生在生物化学上是麻烦的，耗时的， 并且昂贵，这是有效研究EAE中B细胞的障碍。 此外，MOG是一种次要成分，埋在髓鞘结构和啮齿动物MOG中。 与人MOG具有残基差异，这使得其诱导的EAE不依赖于B细胞。髓鞘 相比之下，蛋白脂质蛋白（PLP）是最丰富的髓鞘蛋白， 小鼠和人之间的氨基酸序列同源性。然而，与MOG 35 -55一样，PLP 178 -191诱导 B细胞非依赖性EAE。因此，我们设计了一种新的肽， 结构域的PLP，并已发现它驱动一个强大的B细胞依赖性EAE。我们集团 证明人PBMC中髓鞘特异性CD 8具有调节功能， 在MS患者中抑制CD 4s方面存在缺陷。此外，PLP 178 -191特异性CD 8抑制EAE， 甚至可以消除老鼠的瘫痪。因此，B细胞与致病性CD 4和调节性CD 4+细胞的相互作用， CD 8（直接或通过TFH细胞）可以在我们的新模型中进行研究。这种PLP驱动的B细胞- MS的依赖性小鼠模型将在拟议的工作中开发，不仅将促进 该领域的技术能力，但作为一个急需的竞技场研究B细胞在EAE。

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.