Glycomics of Heparan Sulfate in Bacterial Pathogenesis

描述（由申请人提供）：该R21提案是Liu博士（北卡罗来纳大学）和Park博士（哈佛大学儿童医院/哈佛医学院）的合作成果，旨在研究硫酸肝素（HS）修饰在抑制铜绿假单胞菌肺部感染中的作用。HS是一种高度硫酸化的多糖，大量存在于细胞表面和细胞外基质中。HS在广泛的生物过程中起着重要的调节作用，包括细胞粘附、迁移和增殖、血液凝固和微生物感染。本提案将测试的总体假设是，独特的硫酸HSPG序列差异调节细菌发病机制和宿主防御机制。我们的初步研究表明，由HS 3- o -硫转移酶异构体3 （3OST- 3）生物合成的一种独特的3- o -硫酸化HS可显著抑制小鼠铜绿假单胞菌肺部感染。特异性目的1将利用糖组学方法确定3- o -硫酸化HS如何抑制铜绿假单胞菌肺发病的生物学基础。我们将确定3- o -硫酸化对HS多糖调节可溶性抗菌因子、CXC趋化因子诱导的中性粒细胞募集以及中性粒细胞抗菌机制的影响。我们还将确定在铜绿假单胞菌感染期间是否诱导3OST-3的表达作为宿主防御机制。特异性目的2将定义抑制铜绿假单胞菌肺部感染的HS低聚糖的最小结构特征，并确定HS修饰是否为抗p的靶标。铜绿菌肺炎治疗。我们将鉴定出抑制铜绿假单胞菌肺部感染最有效的3- o -硫酸盐HS序列。这些研究的成功完成应该为开发新的基于hs的治疗铜绿假单胞菌肺炎的机制基础。公共卫生相关性：病原体通过利用存在于细胞表面和细胞外基质上的硫酸肝素（一种高度硫酸化的多糖）来建立感染。本应用将研究硫酸肝素抑制铜绿假单胞菌感染的结构特异性。研究结果可为进一步了解细菌感染机制和开发以肝素为基础的抗菌药物提供依据。

DESCRIPTION (provided by applicant): This R21 proposal is a collaborative effort of Dr. Liu (University of North Carolina) and Dr. Park (Children's Hospital/Harvard Medical School) to investigate the role of heparan sulfate (HS) modifications in inhibiting Pseudomonas aeruginosa lung infection. HS is a highly sulfated polysaccharide present in large amounts on the cell surface and in the extracellular matrix. HS serves as an important regulatory factor in a wide range of biological processes, including cell adhesion, migration and proliferation, blood coagulation, and microbial infections. The overall hypothesis that will be tested in this proposal is that uniquely sulfated HSPG sequences differentially modulate bacterial pathogenesis and host defense mechanisms. Our preliminary studies demonstrated that a unique 3-O-sulfated HS, biosynthesized by the HS 3-O-sulfotransferase isoform 3 (3OST- 3), significantly inhibits P. aeruginosa lung infection in mice. Specific Aim 1 will determine the biological basis of how 3-O-sulfated HS inhibits P. aeruginosa lung pathogenesis using a glycomics approach. We will determine the effects of 3-O-sulfation on the capacity of HS polysaccharides to regulate soluble antimicrobial factors, CXC chemokine-induced neutrophil recruitment, and anti-bacterial mechanisms of neutrophils. We will also determine if the expression of 3OST-3 is induced during P. aeruginosa infection as a host defense mechanism. Specific Aim 2 will define the minimum structural features of HS oligosaccharides that inhibit P. aeruginosa lung infection, and determine if HS modification is a target for anti-P. aeruginosa pneumonia therapy. We will identify the 3-O-sulfated HS sequences that are most effective in inhibiting P. aeruginosa lung infection. Successful completion of these studies should provide a mechanistic foundation for the development of novel HS-based therapies against P. aeruginosa pneumonia. PUBLIC HEALTH RELEVANCE: Pathogens establish the infection by exploiting heparan sulfate, a highly sulfated polysaccharide, present on the cell surface and extracellular matrix. This application will investigate the structural specificity of heparan sulfate for inhibiting infections caused by Pseudomonas aeruginosa. The results from study could lead to a better understanding on the bacterial infection mechanism and develop heparan-based antibacterial agents.