Exploring the Collaborative Cross resource to identify different phenotypes of Lyme neuroborreliosis and disease-contributing genetic factors

项目总结 莱姆病(LD)是美国最常见的扁虱传播疾病(每年约30万-47.5万例)， 由伯氏疏螺旋体螺旋体引起。很复杂。当早期LD诊断为 如果错过了，它就不会得到治疗，学习障碍就会变成慢性疾病。目前还没有人用疫苗。抗菌治疗的研究进展 慢性/持续性感染通常是没有回报的。LD可能会持续数年，表现为皮肤损伤， 关节炎、心脏炎和/或莱姆氏神经疏松症(LNB)。中枢(CNS)和外周神经系统 (三叉神经节)受影响，导致头痛、疲劳、记忆力减退、抑郁、面神经麻痹等 其他。对LNB认识不完全的主要原因是缺乏足够的动物。 模特们。非人灵长类动物是唯一显示出与临床表现相似的模型 人类LNB。然而，成本、试剂可获得性、不可复制的遗传背景和伦理问题 人们的担忧限制了它们的使用。实验室小鼠品系不会出现神经临床症状和脑炎。 目前的知识差距是缺乏合适的LNB小鼠模型。总体目标是发展 小鼠模型将允许BB进入CNS/PNS，在神经中炎性病变 组织，并表现出神经症状。在为期3年的初步研究中，协作十字(CC) 资源(32个品系，约230只小鼠)被广泛用于LNB小鼠模型的鉴定。数据显示 CC系E系小鼠感染BB 6个月后30%以上的小鼠，包括 在BB感染后表现出神经症状，在脑、脊髓出现明显的炎性病变 脊髓和周围神经。在本应用中，建议使用9个品系来测试4种不同的BB菌株 已经在神经组织中显示了由BB感染引起的炎症。还建议包括新的 8个未经检测的CC品系，共40个CC品系(32+8)将用于鉴定遗传 通过数量性状基因座分析影响LNB的因素。将致力于实现以下具体目标： SA1：确定CC系是否感染了不同菌株的BB S.L.将产生独特的LNB 表型。 SA2：定位导致LNB的遗传因素。 这种方法是创新的，S，CC资源在LD研究领域从未被利用过。确定 单一CC株，持续显示神经组织中存在炎症和/或螺旋体 将被认为是LNB领域的一大进步。预计映射分辨率将标识 有信心的因果区，以及确定的数量、效应大小和QTL之间的关系将有所帮助 指导后续调查，并为未来的R01应用奠定基础。建议数 研究意义重大，因为LNB的小鼠模型将使科学界能够研究LNB 更详细的发病机制和为R01的应用提供了基础。

PROJECT SUMMARY Lyme disease (LD), the most prevalent tick-borne illness in the US (~300,000-475,000 annual cases), is caused by spirochetes of Borreliella burgdorferi (Bb) sensu lato (s.l.) complex. When early LD diagnosis is missed, it is left untreated and LD becomes chronic. Human vaccine is unavailable. Antimicrobial treatment of chronic/persistent infection is often unrewarding. LD may last for years, presenting itself as skin lesions, arthritis, carditis, and/or Lyme neuroborreliosis (LNB). Both central (CNS) and peripheral nervous systems (PNS) are affected, which results in headache, fatigue, memory loss, depression, facial nerve palsy among others. The main reason for incomplete understanding of LNB is the limited availability of adequate animal models. Nonhuman primates are the only model that demonstrates similarities to clinical manifestations of human LNB. However, issues of cost, reagents availability, non-reproducible genetic backgrounds, and ethical concerns limit their use. Laboratory mouse strains do not develop neurological clinical signs and encephalitis. The current knowledge gap is the lack of suitable mouse models of LNB. The overall objective is to develop mouse model that will be permissive to Bb entry into the CNS/PNS, develop inflammatory lesions in the neural tissues, and exhibit neurological signs. In the preliminary 3-year-long study, the Collaborative Cross (CC) resource (32 lines; ~230 mice) was extensively used to identify the mouse model of LNB. The data showed that over 30% of mice of CC line E, which were infected with Bb for 6 months, including the mouse that exhibited neurological signs upon Bb infection, developed significant inflammatory lesions in the brain, spinal cord, and peripheral nerves. In this application, it is proposed to test 4 different Bb strains using the 9 lines that have already shown Bb infection-induced inflammation in the neural tissues. It is also proposed to include new 8 CC lines that have not been tested, so that a total of 40 CC lines (32+8) will be used to identify genetic factors contributing to LNB via quantitative trait locus anlaysis. The following Specific Aims will be pursued: SA1: Determine if CC lines infected with various strains of Bb s.l. will produce distinct LNB phenotypes. SA2: Localize genetic factors contributing to LNB. This approach is innovative s the CC resource has never been utilized in the LD research field. Identifying a single CC line that consistently shows the presence of inflammation and/or spirochetes in the neural tissues will be considered a substantial advance in the field of LNB. The mapping resolution is expected to identify causal regions with confidence, and the number, effect sizes, and relationship among QTL identified will help guide subsequent investigations and provide the foundation for a future R01 application. The proposed research is significant because a mouse model of LNB will allow the scientific community to study the LNB pathogenesis in much greater detail and and provide the foundation for a R01 applications.