The Role of Scavenger Receptor gp340 in Mucosal HIV-1 Transmission and Inhibition

清道夫受体 gp340 在粘膜 HIV-1 传播和抑制中的作用

• 批准号: 8704604
• 负责人: Min Lu
• 金额: $ 49.23万
• 依托单位: RBHS-NEW JERSEY MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-01 至 2017-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8704604
• 关键词: Acquired Immunodeficiency Syndrome; Address; Affinity; Animal Model; Antiviral Agents; Binding; Binding Sites; Biological Assay; CCR5 gene; CD209 gene; CD4 Positive T Lymphocytes; Cell fusion; Cell membrane; Cell surface; Cell-Matrix Junction; Cells; Cervical; Competence; Complement; Complex; Data; Development; Disease; Effectiveness; Epithelial; Epithelium; Female; Genital system; Glycoproteins; Goals; HIV Envelope Protein gp120; HIV-1; Human; Immunoglobulin Variable Region; In Vitro; Infection; Inhibitory Concentration 50; Intervention; Investigation; Kinetics; Lead; Mediating; Membrane; Membrane Fusion; Methods; Modeling; Molecular; Molecular Target; Molecular Virology; Monoclonal Antibodies; Mucous Membrane; Multi-Drug Resistance; Mus; Mutation; Oral; Peptides; Pharmaceutical Preparations; Prevalence; Process; Property; Protein Chemistry; Protein Engineering; Receptor Cell; Research; Research Project Grants; Resolution; Role; SRCR proteins; Saliva; Specificity; Structure; Surface; T-Lymphocyte; Testing; Thermodynamics; Tissues; Toxic effect; Vagina; Variant; Viral; Virus; base; biophysical chemistry; combat; design; disulfide bond; env Glycoproteins; in vitro Model; in vivo; inhibitor/antagonist; insight; interdisciplinary approach; macrophage; neutralizing antibody; neutralizing monoclonal antibodies; novel; prevent; programs; receptor binding; reproductive; scavenger receptor; small molecule; structural biology; syndecan; transcytosis; transmission process; vaginal transmission; virucide

DESCRIPTION (provided by applicant): There is an urgent need to understand the initiation and dissemination of HIV-1 infection in mucosal tissues, and to develop new methods for targeting early infection to prevent mucosal HIV-1 transmission. HIV-1 infection requires fusion of the viral and target cell membranes, a process mediated by the viral envelope glycoprotein (Env) and host cell receptors. The human scavenger receptor gp340 has been identified as a secreted component in human saliva that inhibits oral transmission of HIV-1 through a specific interaction with the surface gp120 subunit of an Env spike. Surprisingly the gp120 interaction with the membrane-bound gp340 in the female reproductive tract promotes HIV-1 transcytosis through barrier epithelia and thus infection of CD4+ cells. Our goal in this program is to define the molecular target and mechanism of action of soluble gp340-based HIV-1 entry inhibitors. Our discovery effort will be based on preliminary data obtained with the gp120-binding SRCR domain of gp340 that potently inhibits in vitro infection by HIV-1 with nanomolar IC50 values. We propose a comprehensive, interdisciplinary approach that combines protein chemistry, high- resolution structural determination, thermodynamic and kinetic binding analyses, protein engineering, molecular virology, and animal model efficacy studies. In this project we seek to discover novel HIV-1-specific intervention strategies to inhibit mucosal epithelium-Env binding and virus-cell fusion. The Specific Aims are: 1. To understand the structural basis of gp120 binding by gp340 to inform the design and optimization of novel SRCR domain entry inhibitors. (a) Elucidate the structural properties of the SRCR domain fragment both free and bound to the V3 region. (b) Characterize the energetics of the gp120-gp340 interaction. (c) Use mutational analysis and biophysical methods to dissect the structural determinants of the respective binding sites. (d) Define a "minimal" gp120-binding sequence or set of such sequences. (e) Optimize binding affinity of variants of the SRCR domain, and evaluate their anti-HIV-1 activity in a single-round infectivity assay. 2. To determine the mechanisms by which the gp120-gp340 interaction influences Env structure, function and antigenicity. (a) Determine how V3 mutations identified in Aim 1c influence the functional competence of Env. (b) Characterize the effects of the SRCR domain on the receptor-binding properties of gp120 and its reactivities to neutralizing and non-neutralizing monoclonal antibodies. (c) Determine the virucidal activity of select SRCR domain entry inhibitors against diverse primary HIV-1 strains. 3. To test the effectiveness of optimized SRCR domain entry inhibitors to protect against mucosal HIV-1 infection. (a) Characterize the specificity and potency of select SRCR entry inhibitors in an in vitro model of HIV-1 infection of human cervical and vaginal tissue. (b) Use the humanized mouse vaginal transmission model to assess the in vivo potency and breadth of activity of optimized SRCR entry inhibitors alone and in combination with the gp41 fusion inhibitor C52L and the small-molecule CCR5 coreceptor inhibitor CMPD167. 1

描述（由申请人提供）：迫切需要了解粘膜组织中HIV-1感染的启动和传播，并开发用于靶向早期感染以防​​止粘膜HIV-1传播的新方法。 HIV-1感染需要融合病毒和靶细胞膜，这是病毒包膜糖蛋白（ENV）和宿主细胞受体介导的过程。人类清道夫受体GP340已被确定为人类唾液中的分泌成分，可通过与ENV Spike的表面GP120亚基的特定相互作用来抑制HIV-1的口服传播。令人惊讶的是，在女性生殖道中与膜结合的GP340的GP120相互作用可通过屏障上皮促进HIV-1转胞胞菌，从而促进了CD4+细胞的感染。我们在该程序中的目标是定义基于GP340的HIV-1进入抑制剂的分子靶标和作用机理。我们的发现工作将基于用GP340的GP120结合SRCR结构域获得的初步数据，该数据可在HIV-1中有效抑制HIV-1的体外感染，并具有纳莫尔IC50值。我们提出了一种综合的跨学科方法，该方法结合了蛋白质化学，高分辨率结构测定，热力学和动力学结合分析，蛋白质工程，分子病毒学和动物模型疗效研究。在这个项目中，我们试图发现新型的HIV-1特异性干预策略，以抑制粘膜上皮ENV结合和病毒细胞融合。具体目的是：1。了解GP340结合GP120的结构基础，以告知新型SRCR域进入抑制剂的设计和优化。 （a）阐明了自由且结合到V3区域的SRCR结构域片段的结构特性。 （b）表征GP120-GP340相互作用的能量。 （c）使用突变分析和生物物理方法剖析相应结合位点的结构决定因素。 （d）定义“最小” GP120结合序列或一组此类序列。 （e）优化SRCR结构域变体的结合亲和力，并评估其在单轮感染性测定中的抗HIV-1活性。 2。确定GP120-GP340相互作用影响ENV结构，功能和抗原性的机制。 （a）确定AIM 1C中V3突变如何影响Env的功能能力。 （b）表征了SRCR结构域对GP120受体结合特性及其反应性对中和和非中和非中性单克隆抗体的影响。 （c）确定针对不同原发性HIV-1菌株的精选SRCR域进入抑制剂的病毒活性。 3。测试优化的SRCR域进入抑制剂的有效性以防止粘膜HIV-1感染。 （a）表征人宫颈和阴道组织的HIV-1感染体外模型中选择SRCR进入抑制剂的特异性和效力。 （b）仅使用人源化的小鼠阴道传播模型来评估仅优化SRCR进入抑制剂的体内效力和活动的广度，并与GP41融合抑制剂C52L和小分子CCR5 CR5 CROCECTOR抑制剂CMPD167结合使用。 1