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.

在全球一级，世界卫生组织（世卫组织）估计有约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，这些毒力因子有助于其 致病菌包括荚膜多糖、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， 细胞与机械破坏的Spn产生的可溶性部分的结合导致细胞因子的有效抑制 生产和颗粒释放。我们观察到的抑制是一种非常新颖和意想不到的性质， 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 和实验室分离物，发现它们都能抑制效应T细胞功能。 在表征抑制因子时，我们发现它是热不稳定的和蛋白酶敏感的。通过 通过一系列分级分离和测序方法，鉴定了候选分子。两名候选人被 克隆、工程化以表达His标签，并在E.大肠杆菌，允许有效分离，并进一步 试验.我们的数据表明，其中一种候选物可以重现用 破坏的Spn，此外，发现功能独立于已知的Spn的酶活性。 蛋白 Spn主动调节效应细胞功能的能力为免疫调节提供了一种新的机制。 由这种临床上重要的细菌调节。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易感性。另外我们 提出研究以阐明调节蛋白与T细胞相互作用的性质。最后我们将 确定人T细胞对Spn负调节能力的易感性。这些关键 将在以下目标中处理这些问题。目的1确定T细胞的分化状态 影响其对Spn PepN的免疫调节作用的敏感性。目的2确定PepN是否 与细胞外膜相互作用或进入细胞及其潜在伴侣 PepN相互作用。目的3确定Spn组分的存在如何影响人T细胞的功能。