Immune regulation by pneumococcus

肺炎球菌的免疫调节

• 批准号: 9317155
• 负责人: Martha Ann Alexander-Miller
• 金额: $ 23.25万
• 依托单位: WAKE FOREST UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-07 至 2019-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9317155
• 关键词: Address; Adherence; American; Autolysis; Bacteria; Bacterial Infections; Binding; Bronchus-Associated Lymphoid Tissue; Cell physiology; Cells; Centers for Disease Control and Prevention (U.S.); Clinical; Contracts; Cytoplasmic Granules; Data; Disease; Effector Cell; Engineering; Escherichia coli; Fractionation; Funding Mechanisms; Gram-Positive Bacteria; Hospitalization; Host Defense; Human; Immune; Immune Evasion; Immunological Models; Individual; Infection; Laboratories; Lead; Location; Lung; Mechanics; Membrane; Memory; Modeling; Mus; Nature; Peptide Hydrolases; Pneumococcal Infections; Pneumococcal Pneumonia; Polysaccharides; Positioning Attribute; Predisposition; Production; Property; Proteins; Regulation; Sampling; Series; Serotyping; Site; Streptococcus pneumoniae; Streptococcus pneumoniae plY protein; T cell differentiation; T cell regulation; T-Cell Activation; T-Lymphocyte; Testing; Therapeutic; Tissues; Virulence Factors; World Health Organization; alanine aminopeptidase; capsule; combat; cytokine; design; experimental study; extracellular; genetic regulatory protein; immune function; immunoregulation; innovation; insight; novel; pneumococcal surface protein A; response

At the global level, the World Health Organization (WHO) estimates there are ~14 million cases of serious pneumococcal disease and more than 1.6 million people die each year from invasive pneumococcal disease (IPD). Streptococcus pneumoniae has a number of virulence factors that contribute to its ability to cause disease including polysaccharide capsule, pneumolysin and pneumococcal surface proteins A-C. We have recently identified a novel immunoregulatory property of Spn. Our data show exposure of murine effector cells to a soluble fraction generated from mechanically disrupted Spn results in effective inhibition of cytokine production and granule release. The inhibition we observe is a highly novel and unexpected property of pneumococcus. Importantly, this effect is not restricted to a single strain. We have tested an array of clinical and laboratory isolates finding that all could inhibit T effector cell function. In characterizing the inhibitory factor, we found it to be heat labile and protease sensitive. Through a series of fractionation and sequencing approaches, candidate molecules were identified. Two candidates were cloned, engineered to express a His tag, and expressed in E. coli allowing for efficient isolation and further testing. Our data show that one of the candidates could reproduce the T cell inhibitory effect observed with disrupted Spn and in addition, function was found to be independent of the known enzymatic activity of the protein. The ability of Spn to actively regulate function in effector cells presents a new mechanism for immune regulation by this clinically important bacterium. The studies in this application are designed to understand how the differentiation state of the T cell impact susceptibility to the negative regulatory protein. In addition, we propose studies to elucidate the nature of the interaction of the regulatory protein with T cells. Finally, we will determine the susceptibility of human T cells to the negative regulatory capabilities of Spn. These critical questions will be addressed in the following aims. Aim 1 To determine how the differentiation state of a T cell impacts its susceptibility to the immunoregulatory effects of Spn PepN. Aim 2 To determine whether PepN interacts with the extracellular membrane or gains entry into the cell and the potential partners with which PepN interacts. Aim 3 To determine how the presence of Spn components impacts function in human T cells.

在全球范围内，世界卫生组织 (WHO) 估计约有 1400 万例 严重的肺炎球菌疾病，每年有超过 160 万人死于侵袭性肺炎球菌 疾病（IPD）。肺炎链球菌具有许多毒力因子，使其能够 引起疾病的包括多糖荚膜、肺炎球菌溶血素和肺炎球菌表面蛋白A-C。我们 最近发现了 Spn 的一种新的免疫调节特性。我们的数据显示小鼠效应器的暴露 将细胞转化为机械破坏的 Spn 产生的可溶性组分，可有效抑制细胞因子 生产和颗粒释放。我们观察到的抑制是一种非常新颖且意想不到的特性 肺炎球菌。重要的是，这种效应并不局限于单一菌株。我们已经测试了一系列临床 实验室分离发现所有这些都可以抑制 T 效应细胞功能。 在表征抑制因子时，我们发现它对热不稳定且对蛋白酶敏感。通过一个 通过一系列的分级分离和测序方法，确定了候选分子。两名候选人是 克隆、设计以表达 His 标签，并在大肠杆菌中表达，以便有效分离和进一步 测试。我们的数据表明，其中一种候选药物可以重现观察到的 T 细胞抑制作用 Spn 被破坏，此外，功能被发现独立于已知的酶活性 蛋白质。 Spn 主动调节效应细胞功能的能力为免疫提供了一种新机制 这种临床上重要的细菌的调节。本申请中的研究旨在了解 T 细胞的分化状态如何影响对负调节蛋白的敏感性。此外，我们 提出研究来阐明调节蛋白与 T 细胞相互作用的性质。最后，我们将 确定人类 T 细胞对 Spn 负调节能力的敏感性。这些关键的 问题将在以下目标中得到解决。目标 1 确定 T 细胞的分化状态 影响其对 Spn PepN 免疫调节作用的敏感性。目标 2 确定 PepN 是否 与细胞外膜相互作用或进入细胞及其潜在伙伴 PepN 相互作用。目标 3 确定 Spn 成分的存在如何影响人类 T 细胞的功能。