Immunobiology of the DsrA protein of H. ducreyi

杜热氏嗜血杆菌是生殖器溃疡下巴疾病的病原体，是一种重要的公众 全球几个地区的健康问题。我们建议继续研究外膜的结构/功能。 杜氏杆菌膜蛋白DSRA的表达，并测定其疫苗效力。这样做的长期目标是 研究的目的是开发一种针对软骨软骨症的疫苗。 DSRA是一种多功能三聚体自身转运蛋白，具有较高的血清对H. 杜雷伊。此外，DSRA结合细胞外基质成分纤维连接蛋白和玻璃连接蛋白，并赋予 在H.ducreyi上附着角质形成细胞的能力。DSRA的这4个功能中的每一个都被认为是 其他细菌系统中的毒力因素。 具体目标1建议继续调查DSRA的结构成分，这些成分涉及其多重 功能。角质形成细胞结合所需的结构域(S)将使用一组DsrA突变体进行鉴定。 DSRA的4种功能中的每一种所需的特定残基也将使用多肽进行精确定位 文库和定点突变。已定义的DSRA突变体将在实验人身上进行测试 确定感染所需的DSRA的哪种功能。这些研究的结果 实验将侧重于目标2中描述的疫苗研究，并为其提供信息。 特定目的2建议确定DSRA是否是一种有效的疫苗，用于猪的实验模型 下巴症。RDsrA主动免疫或抗DSRA单抗被动免疫 将会检查DSRA作为软骨软骨病疫苗的有效性。无毒佐剂将是 作为弗洛因德佐剂的替代品进行检验。

Haemophilus ducreyi, the etiological agent of the genital ulcer disease chancroid, is a significant public health problem in several regions woridwide. We propose to continue structure/function studies of the outer membrane protein DsrA of H. ducreyi and determine its vaccine potential. The long-term goal of this research is to develop a vaccine against chancroid. DsrA is a multifunctional trimeric autotransporter protein conferring high levels of serum resistance to H. ducreyi. Additionally, DsrA binds the extracellular matrix components fibronectin and vitronectin and confers upon H. ducreyi the ability to attach to keratinocytes. Each of these 4 functions of DsrA is considered a virulence factor in other bacterial systems. Specific aim 1 proposes to continue investigating the structural components of DsrA involved in its multiple functions. The domain(s) required for keratinocyte binding will be identified using a panel of dsrA mutants. The specific residues required for each of the 4 functions of DsrA will also be pinpointed using peptide libraries and site-directed mutagenesis. Defined dsrA mutants will be tested in the experimental human model of chancroid to determine which function of DsrA is required for infection. The results from these experiments will focus and inform efforts for the vaccine studies described in aim 2. Specific aim 2 proposes to determine if DsrA is an effective vaccine in the experimental swine model of chancroid. Active immunization with rDsrA or passive immunization with an anti-DsrA monoclonal antibody will be done to examine the efficacy of DsrA as a vaccine against chancroid. Non-toxic adjuvants will be examined as substitutes for Freund's adjuvant.