Identification of protective proteins of Francisella using a novel comparative im

描述(申请人提供)：图拉氏方济氏菌是呼吸性图拉热症的病原体，呼吸性图拉热症是人类的一种衰弱疾病。这种细菌病原体已被列为A类选择剂，因为它具有极高的毒力，而且容易通过气雾剂途径传播。到目前为止，还没有有效的免疫疗法或疫苗被批准用于预防这种疾病。虽然临床和实验研究表明Th-1类宿主免疫反应具有保护性，但驱动这些反应的细菌抗原还没有很好地确定。识别这些抗原将有助于制定有效的预防策略来预防这种令人衰弱的疾病。这包括拟议研究的目标。为此，我们的目标是利用一种新的方法来比较Francisella的免疫优势蛋白质谱，使用来自接种突变Francisella菌株的小鼠的血清，该突变菌株因引起感染而减毒，但不能保护小鼠免受致命的野生型生物的攻击，以及来自接种了突变株的小鼠的血清，这些突变株不仅被减毒，而且还保护小鼠免受致命的攻击。根据我们的初步研究，我们相信这种独特的方法将识别只与保护性反应相关的弗朗西塞拉蛋白，然后可以用作疫苗候选。在这一系列中，我们配备了一组方济各氏菌的减毒/非保护性和减毒/保护性突变株，它们将用于接种小鼠，从这些小鼠身上收集的血清将用于探测方济氏菌的总蛋白，然后对免疫优势蛋白进行测序和鉴定，这些蛋白只与保护性突变株接种的小鼠的血清反应(目标1)。然后，这些蛋白将被生产为重组融合蛋白，并测试它们对具有毒力的方济各氏菌株肺部感染的保护效果(AIM 2)。我们相信，这些研究将发现弗朗西斯氏菌蛋白能够产生保护性的抗弗朗西斯氏菌免疫，从而成为针对这种病原体的亚单位疫苗的候选者。此外，这种新的比较免疫蛋白质组学策略也可以作为一个平台来识别其他细菌病原体的候选疫苗。拟议研究的结果预计将使弗朗西塞拉亚单位疫苗的研究更进一步。

DESCRIPTION (provided by applicant): Francisella tularensis is the causative agent of respiratory tularemia, a debilitating disease of humans. This bacterial pathogen has been listed as Category A Select Agent owing to its extreme virulence and the ease of its dissemination via aerosol route. To date there is no effective immune therapy or vaccine licensed for prevention of this disease. Although clinical and experimental studies have shown that Th-1 type of host immune responses are protective, bacterial antigens driving these responses are not well defined. Identification of such antigens will aide in formulating effective prevention strategies fr this debilitating disease. This encompasses the goal of the proposed studies. For this, we aim to utilize a novel approach of comparing the immunodominant protein profile of Francisella using sera from mice inoculated with a mutant Francisella strain that is attenuated for causing the infection but does not protect the mice from a lethal challenge with the virulent wild-type organisms and sera from mice inoculated with mutants that not only are attenuated but also protect the mice from lethal challenge. Based on our preliminary studies we believe that this unique approach will identify Francisella proteins associated only with the protective response which can then be utilized as vaccine candidates. In this line, we are armed with a collection of attenuated/non-protective and attenuated/protective mutants of Francisella which will be used to inoculate the mice and the sera collected from these mice will be used to probe total proteins of Francisella followed by sequencing and identification of immunodominant proteins reactive only to the sera from mice inoculated with protective mutants (Aim 1). These proteins will then be produced as recombinant fusion proteins and tested for their protective efficacy against pulmonary infection with virulent Francisella strains (Aim 2). We believe that these studies will uncover Francisella proteins capable of generating protective anti-Francisella immunity thus serving as candidates for a subunit vaccine against this pathogen. Additionally, this novel strategy of comparative immunoproteomics may serve as a platform to identify vaccine candidates for other bacterial pathogens as well. The outcome of proposed studies is expected to take the Francisella subunit vaccine research a step further.