ANTIGENIC VARIATION IN HUMAN AND MURINE LYME BORRELIOSIS

人和鼠莱姆疏螺旋体病的抗原变异

• 批准号: 6099485
• 负责人: Erol Fikrig
• 金额: $ 17.16万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-08-01 至 2001-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6099485
• 关键词: Borrelia; Lyme disease; antibacterial antibody; antibody formation; antibody specificity; antigen antibody reaction; arthritis; bacterial antigens; bacterial proteins; bactericidal immunity; disease /disorder model; genetically modified animals; host organism interaction; human tissue; humoral immunity; immune tolerance /unresponsiveness; laboratory mouse; microorganism immunology; molecular cloning; nucleic acid sequence; passive immunization; surface antigens; synovial fluid; ticks; western blottings

We propose that the pathogenesis of Lyme arthritis is due to the persistence of Borrelia burgdorferi, and that B. burgdorferi with variable outer surface proteins (Osps) that do not bind protective antibody -- and therefore resist elimination by the host -- preferentially survive within infected joints. Our recent studies support this belief by showing that borreliacidal OspA or B antibodies elicited during infection in mice or humans are unable to clear the spirochete from the host although immunizations with murine or human OspA or B antibodies protect mice against infection. To determine if OspA or B from B. burgdorferi that survive within the synovium of patients with Lyme arthritis have variable OspA or B, we will characterize spirochete DNA recovered from clinical specimens. First, ospA/B will be amplified from affected synovial fluid at time points throughout the illness and analyzed for mutations. Second, OspA or B will be expressed in Escherichia coli and probed to determine whether protective OspA or B antibodies bind with the antigens. We predict, based on our preliminary data, that the proteins will not bind, or poorly bind, to these antibodies --suggesting that spirochetes expressing OspA or B that do not bind protective antibodies persist preferentially in infected patients. Moreover, as we and others have recently shown that OspC or F elicit protective responses (albeit less pronounced than OspA or B), we will also assess the variability of these proteins. Third, to determine whether patients have the capacity to mount a borreliacidal antibody response -- indicating that microbial persistence is not due to a host defect -- we will assess whether patient serum or synovial fluid is protective in mice and delineate the immune specificity. We will then determine how the selective pressure of protective antibody influences B. burgdorferi variability within a mixed population of spirochetes by allowing ticks infected with a heterogeneous population of B. burgdorferi to engorge upon mice and then comparing Osp variability of the spirochetes in the ticks, and B. burgdorferi recovered from infected mice. Our preliminary data show that OspA or B antibodies exert a selective pressure resulting in the enriched recovery of spirochetes with variant OspA or B from immunized mice -- analogous to our studies in patients. We will then assess Lyme disease in transgenic mice that are immunologically tolerant to specific B. burgdorferi Osps -- proposing that these mice will develop more severe infection than non transgenic litter mates because the selective pressure of Osp antibody has been ablated, and that variable B. burgdorferi will not preferentially persist in the transgenic mice. Our recent studies support this belief by showing that C3H mice infected with B. burgdorferi develop arthritis that subsides with the rise of high titers of B. burgdorferi antibodies, including OspA and B whereas scid develop persistent arthritis -- suggesting that the resolution of disease may be due to the establishment of a protective response. In summary, these studies will determine if protective antibodies, elicited during infection, cause the selective survival of spirochetes with variations in "protective" Osps -- and that these variant spirochetes preferentially live in patients and mice with chronic infection. The experiments will yield information on the factors that influence B. burgdorferi persistence and the pathogenesis of Lyme disease.

我们建议莱姆关节炎的发病机理是由于 Borrelia Burgdorferi的持久性，以及可变的B. burgdorferi 不结合保护性抗体的外表面蛋白（OSPS） - 因此抵抗宿主消除 - 优先在 感染的关节。我们最近的研究通过表明 在小鼠感染期间引起的胆道化OSPA或B抗体或B抗体 尽管人类无法从宿主那里清除螺旋体 用鼠或人类OSPA或B抗体进行免疫接种保护小鼠 反对感染。 确定来自B. burgdorferi的OSPA或B是否在 莱姆关节炎患者的滑孢菌具有可变的OSPA或B，我们将 表征从临床标本中回收的螺旋藻DNA。第一的， OSPA/B将从受影响的滑液上放大时间点 在整个疾病中，并分析了突变。第二，OSPA或B将 在大肠杆菌中表达，并探测以确定是否是否 保护性OSPA或B抗体与抗原结合。我们预测，基于 在我们的初步数据上，蛋白质不会结合或结合不佳， 对于这些抗体 - 提出表达OSPA或B的螺旋体 不结合保护性抗体在感染中优先持续 患者。而且，正如我们和其他人最近表明的那样，OSPC或F 引起保护性反应（尽管不如OSPA或B明显），但我们 还将评估这些蛋白质的变异性。第三，确定 患者是否有能力安装去作性硼酸抗体 响应 - 表明微生物持久性不是由于宿主 缺陷 - 我们将评估患者血清或滑液是 小鼠保护性，并描述免疫特异性。 然后，我们将确定保护性抗体的选择性压力 影响B. burgdorferi的变异性 螺旋体通过允许感染异质种群的壁虱 B. Burgdorferi到Engorge对小鼠，然后比较OSP的可变性 tick中的螺旋体和B. Burgdorferi从感染中恢复了 老鼠。我们的初步数据表明，OSPA或B抗体发挥A 选择性压力，导致螺旋体的丰富恢复 来自免疫小鼠的变体OSPA或B，类似于我们的研究 患者。 然后，我们将评估转基因小鼠的莱姆病 在特定的B. burgdorferi osps上具有免疫学耐受性 - 提出 这些小鼠会比非转基因垃圾产生更严重的感染 伴侣，因为OSP抗体的选择性压力已经消融，并且 该变量B. burgdorferi不会优先持续 转基因小鼠。我们最近的研究通过表明 C3H小鼠感染了B. burgdorferi的C3H小鼠，患有关节炎，与 B. burgdorferi抗体的高滴度的兴起，包括OSPA和 b，而SCID患有持续性关节炎 - 表明 疾病的解决可能是由于建立了保护性 回复。 总而言之，这些研究将确定保护性抗体是否是 在感染过程中引起的引起，导致螺旋体的选择性存活 具有“保护性” OSP的变化 - 这些变体螺旋体 优先生活在患有慢性感染的患者和小鼠中。这 实验将产生有关影响B的因素的信息。 Burgdorferi持久性和莱姆病的发病机理。