Glycomics of Heparan Sulfate in Bacterial Pathogenesis

描述（由申请人提供）：该R21提案是Dr. Liu（北卡罗来纳州大学）和Dr. Park（儿童医院/哈佛医学院）的合作成果，旨在研究硫酸乙酰肝素（HS）修饰在抑制铜绿假单胞菌肺部感染中的作用。HS是高度硫酸化的多糖，大量存在于细胞表面和细胞外基质中。HS作为一个重要的调节因子在广泛的生物过程，包括细胞粘附，迁移和增殖，血液凝固，和微生物感染。将在本提案中测试的总体假设是，独特的硫酸化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，一个独特的3-O-硫酸化的HS，生物合成的HS 3-O-磺基转移酶亚型3（3 OST- 3），显着抑制铜绿假单胞菌肺部感染小鼠。具体目标1将使用糖组学方法确定3-O-硫酸化HS如何抑制铜绿假单胞菌肺发病机制的生物学基础。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和中性粒细胞抗菌机制的能力的影响。我们还将确定在铜绿假单胞菌感染期间是否诱导3 OST-3的表达作为宿主防御机制。具体目标2将定义抑制铜绿假单胞菌肺部感染的HS寡糖的最小结构特征，并确定HS修饰是否是抗铜绿假单胞菌肺炎治疗的靶点。我们将鉴定在抑制铜绿假单胞菌肺部感染中最有效的3-O-硫酸化HS序列。这些研究的成功完成应为开发针对铜绿假单胞菌肺炎的新型HS疗法提供机制基础。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乙酰肝素（一种高度硫酸化的多糖）来建立感染。本申请将研究硫酸乙酰肝素抑制铜绿假单胞菌引起的感染的结构特异性。研究结果有助于更好地了解细菌感染的机制，并开发基于肝素的抗菌药物。

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.