Immune regulation by pneumococcus

在全球一级，世界卫生组织(世卫组织)估计约有1400万例 严重的肺炎球菌病，每年有160多万人死于侵袭性肺炎球菌 疾病(IPD)。肺炎链球菌有许多毒力因子，这些因素有助于它的能力 致病物质包括多糖胶囊、肺炎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。我们的数据显示暴露在老鼠身上的效应器 机械破坏Spn产生的细胞可溶部分可有效抑制细胞因子 生产和颗粒剂释放。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，这种影响并不局限于单一菌株。我们已经测试了一系列临床 以及实验室分离出的ALL均可抑制T效应细胞功能。 在对抑制因子的鉴定中，我们发现它对热不稳定，对蛋白酶敏感。通过一个 通过一系列的分离和测序方法，确定了候选分子。有两位候选人是 克隆，设计表达组氨酸标签，并在大肠杆菌中表达，从而实现有效分离和进一步 测试。我们的数据显示，其中一个候选者可以重现观察到的T细胞抑制效应 Spn被破坏，此外，功能被发现不依赖于已知的酶活性 蛋白。 Spn主动调节效应细胞功能的能力为免疫提供了新的机制 由这种临床上重要的细菌进行调节。本应用程序中的研究旨在了解 T细胞的分化状态如何影响对负调控蛋白的敏感性。此外，我们 建议进行研究，以阐明调节蛋白与T细胞相互作用的本质。最后，我们会 确定人类T细胞对Spn的负调节能力的敏感性。这些关键因素 这些问题将在以下目标中得到解决。目的1确定T细胞的分化状态如何 影响其对Spn PepN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和与之潜在的合作伙伴 PepN相互作用。目的3确定Spn组分的存在如何影响人类T细胞的功能。

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.