Immunophenotypic analysis of the cutaneous humoral response in early Lyme disease

项目总结 莱姆病是一种多系统疾病，由壁虱传播的伯氏疏螺旋体感染引起。 可表现为局部皮肤感染或涉及多个皮肤部位的播散性感染 以及其他器官系统，包括心脏、神经系统和关节。体液免疫是一种重要的宿主 对伯氏杆菌感染的防御和血液中强烈的早期B细胞反应与 症状解决。伯氏杆菌感染也会引发自身抗体的产生和免疫失调。 与自身免疫病理有关。尽管抗体的产生对宿主防御很重要，但几乎没有 已知它们在皮肤中的作用，正是在皮肤上，扁虱传播的螺旋体首先建立感染。我们已经申请了 先进的转录组技术研究在原发性红斑中发现的稀疏B细胞群 表现为局限性或播散性莱姆病的受试者的移行皮损和非皮损皮肤。 使用10倍单细胞免疫谱系和基因表达谱，我们鉴定了来自 具有对感染等免疫挑战(即克隆性)作出反应的特征的B细胞 扩展、体细胞超突变和等级转换)。这些序列在非皮损皮肤中不存在， 但在某些情况下，在同一患者的血液中也发现了这种病毒。在初步数据中，我们产生了11 基于这些抗体序列的重组人单抗(MAb)到目前为止已经发现 这2个单抗与暴露在表面的15-20kD的BB抗原发生反应。在这项建议中，我们将扩大 生产重组单抗，并确定该单抗是否与伯氏杆菌或自身抗原反应。我们将使用 用于高血压病的新开发和创新的快速外蛋白质组抗体谱(REAP)发现工具 对重组单抗和免疫血清进行通过量筛选，以检测其与外源蛋白质的反应性。 从莱姆受试者确诊时和恢复期几个时间点前瞻性收集的存档血清 随着时间的推移，将对已识别的BB抗原以及自身抗原的反应性进行筛选。结果是 这些研究将是对早期莱姆病B细胞抗原特异性的第一次组织特异性分析， 并对免疫反应的持久性和抗体影响感染的能力提供了洞察 结果。它还可以为早期莱姆病的诊断试验提供新的靶抗原的鉴定。 或者将新的感染与以前治疗的感染区分开来。此外，这些研究可能会提供对 伯氏杆菌感染后首次出现自我反应性及靶向反应的演变 抗原。这些研究的成功完成将为皮肤B细胞反应的研究创造一个模型 对其他具有公共卫生意义的病媒传播的病原体。

PROJECT SUMMARY Lyme disease, due to infection with the tick-transmitted spirochete Borrelia burgdorferi, is a multisystem disorder that can present with either localized skin infection or with disseminated infection involving multiple skin sites and other organs systems, including the heart, nervous system and joints. Humoral immunity is a critical host defense against B. burgdorferi infection, and a strong early B cell response in the blood is associated with symptom resolution. B. burgdorferi infection can also trigger autoantibody production and immune dysregulation associated with autoimmune pathologies. Despite the importance of antibody production to host defense, little is known about their role in the skin where tick-transmitted spirochetes first establish infection. We have applied advanced transcriptome technologies to study the sparse B cell populations found in the primary erythema migrans lesion and nonlesional skin of subjects who presented with localized or disseminated Lyme disease. Using 10X single cell immune repertoire and gene expression profiling, we identified antibody sequences from B cells that have the characteristics of a response to an immune challenge such as infection (i.e. clonal expansion, somatic hypermutation and class switching). These sequences were not present in nonlesional skin, but in some cases were also found in the blood of the same patient. In preliminary data, we have produced 11 recombinant human monoclonal antibodies (mAb) based on these antibody sequences and to date, have found that 2 mAb react with a surface exposed Bb antigen, 15-20kD in size. In this proposal, we will expand the recombinant mAb production and determine if the mAb react with B. burgdorferi or self-antigens. We will use the newly developed and innovative Rapid Exoproteome Antibody Profiling (REAP) discovery tool for high throughput screening of recombinant mAb and immune sera for reactivity against proteins in the exoproteome. Archived sera collected prospectively from Lyme subjects at diagnosis and several time points in convalescence will be screened for reactivity against identified Bb antigens as well as self antigens over time. The results of these studies will be the first tissue-specific analysis of the antigen specificity of B cells in early Lyme disease, and provide insight into the durability of immune responses and capacity of the antibodies to influence infection outcomes. It may also provide identities of new target antigens for use in diagnostic tests for early Lyme disease or distinguish new infection from previously treated infections. In addition, these studies may provide insight into when self-reactivity first arises after B. burgdorferi infection and the evolution of the response to targeted antigens. Successful completion of these studies will create a model for investigation of the skin B cell response to other vector-borne pathogens of public health significance.