Analysis of pgf 54 Members in Lyme Disease Serodiagnosis

描述（由申请人提供）：伯氏疏螺旋体，莱姆病的病原体，维持在一个感染循环中，涉及细菌从蜱虫传播到哺乳动物宿主。在传播过程中，螺旋体遇到环境刺激的许多变化，并通过修改可能在适应、感染和持久性中证明重要的基因表达来对这些环境变化作出反应。许多差异表达的基因驻留在许多线性（lp）和圆形（cp）质粒上，这些质粒可以从该螺旋体中分离出来。迄今为止，许多这些pH和温度调节膜蛋白的功能尚未确定。令人感兴趣的是，当螺旋体暴露于模拟附着、喂食蜱虫或哺乳动物环境的温度和pH值（37℃和pH 7.0）时，定位于质粒lp54的旁系基因家族（pgf） 54的几个成员在体外被上调。同样，在模拟自由生活、不喂食蜱虫的实验室条件下（23摄氏度、pH值8.0），这些pgf 54成员中的许多都被下调。此外，我们已经确定通过蜱传感染的小鼠血清可识别19种螺旋体膜蛋白，其中两种是pgf 54的成员。在Specific Aim 1中，我们打算评估使用pgf 54成员编码的蛋白作为早期、早期播散和晚期莱姆病的诊断标志物。在特异性目标2中，我们将确定使用pgf 54编码的重组蛋白作为候选疫苗的有效性。此外，在Specific Aim 3中，我们将鉴定在小鼠蜱传感染期间伯氏疏螺旋体表达的其他ph调节膜蛋白，这可能对诊断有意义。

DESCRIPTION (provided by applicant): Borrelia burgdorferi, the etiologic agent of Lyme disease, is maintained in an infectious cycle that involves the transmission of the bacterium from an Ixodes tick to a mammalian host. During transmission the spirochetes encounter numerous alterations in environmental stimuli, and respond to these alterations in the environment by modifying the expression of genes that may prove important in adaptation, infection and persistence. Many of the genes that are differentially expressed reside on the many of the linear (lp) and circular (cp) plasmids that can be isolated from this spirochete. To date, the function of many of these pH and temperature-regulated membrane proteins has not been determined. Of interest are several members of paralogous gene family (pgf) 54 that localize to plasmid lp54 that are up-regulated in vitro when spirochetes are exposed to a temperature and pH (37 degrees C and pH 7.0) that mimic the environment of the attached, fed tick or mammal. Likewise, many of these pgf 54 members are down regulated by laboratory conditions that mimic the free-living, unfed tick (23 degrees C and pH 8.0). Moreover, we have determined that sera from mice infected via tick-borne transmission recognize nineteen borrelial membrane proteins, two of which are members of pgf 54. In Specific Aim 1 we intend to assess using the proteins encoded by the pgf 54 members as diagnostic markers of early, early-disseminated, and late stage Lyme disease. In Specific Aim 2 we will determine the efficacy of using recombinant proteins encoded by pgf 54 as vaccine candidates. Furthermore, in Specific Aim 3 we will identify additional pH-regulated membrane proteins expressed by B. burgdorferi during tickborne infection of mice that may be of diagnostic interest.