Innate Immune Activation in Malaria

摘要：急性疟疾感染常伴有全身性细胞因子风暴的症状。 这些症状是由吞噬细胞活化引起的全身炎症反应引起的。整体 我们正在进行的项目的目标是确定先天免疫激活和调节的机制， 疟疾的临床症状和并发症。此补助金是R 01 AI 079293的续期。此RO 1具有 成果丰硕，发表了40篇出版物，包括16篇同行评审的原创手稿， 在最近一个资助期内的工作（其中9项与资助直接相关，另外5篇论文获得资助 巴西的基础设施）。在过去的十年里，我们已经定义了我们认为是 主要的“疟疾毒素”及其同源受体：寄生虫富含AT的DNA、免疫复合物、疟原虫色素、游离 血红素和GPI锚。我们发现，这些配体驱动Toll样受体（TLR 2、3、4、9）、NOD样受体（NOD-1）、NOD样受体（NOD-2）、NOD样受体（NOD-3）、NOD样受体（NOD-4）、NOD样受体（NOD-3）和NOD样受体（NOD-4）。 受体（NLRP 3，NLRP 12），在黑素瘤2（AIM 2）中不存在，以及cGAS-STING途径。我们的工作 认识到细胞溶质DNA结合蛋白Cnbp调节IL 12 b和IFNg，并且在某些条件下， I型干扰素我们已经描述了疟疾中的先天免疫记忆现象，这是一部分 一个表观遗传过程，既可以保护人类宿主，或在某些条件下，可能导致严重的 疟疾（特别是如果伴有细菌感染）。最近，我们已经确定了几个lncRNA在 疟疾刺激的吞噬细胞，其中许多可能调节临床疾病。因此，我们已经完成了 我们五年前就开始做的事在这次更新中，我们计划重点确定最基本的 通过结合体外细胞培养研究调节疟疾先天免疫系统的方法 老鼠的工作与病人样本的分析。有三个目标。拨款的主要假设是 先天性免疫反应是通过染色质的表观遗传修饰高度调节的， 转录水平。这种调节涉及淋巴细胞与吞噬细胞的相互作用，导致先天性 免疫训练和各种表观遗传变化。表观遗传变化涉及对 染色质，染色质可及性的改变（目的1）。此外，疟疾期间的炎症信号导致 在包括LUCAT-1和LIMIT在内的长非编码RNA的产生中，我们将详细探讨其作用 在体外，在LUCAT-1 KO小鼠和人临床样品中（目的2）。最后，我们将定义一个 转录调节因子Cnbp是一种核酸结合蛋白，我们最初认为它是一种DNA 传感器. Cnbp通过与IL-12 β的相互作用参与IL-12 β的转录和表达调控 用c-Rel和IL 12启动子（Aim 3）。在上述所有目的中，我们将分析白细胞 来自巴西韦略港研究中心的发热疟疾患者（间日疟和恶性疟）。这笔赠款 是一个雄心勃勃的项目，建立在成功完成两个先前雄心勃勃的赠款。在未来 在新的筹资周期中，我们希望为我们对疟疾先天免疫的了解做出更大贡献。

ABSTRACT: Acute infection with malaria is often accompanied by the symptoms of a systemic cytokine storm. These symptoms result from a systemic inflammatory response via the activation of phagocytes. The overall goal of our ongoing project is to define the mechanisms of innate immune activation and regulation that account for the clinical symptoms and complications of malaria. This grant is a renewal of R01 AI079293. This RO1 has been highly productive having resulted in 40 publications including 16 peer-reviewed manuscripts of original work in the latest funding period (9 of these directly related to the grant, an additional 5 papers were supported by grant-related infrastructure in Brazil). Over the last decade, we have defined what we believe to be the principal “malaria toxins” and their cognate receptors: parasite AT-rich DNA, immune complexes, hemozoin, free heme, and GPI anchors. We found that these ligands drive Toll-like receptors (TLRs 2, 3, 4, 9), NOD-like receptors (NLRP3, NLRP12), absent in melanoma 2 (AIM2), and the cGAS-STING pathway. Our work led to recognition that a cytosolic DNA binding protein Cnbp, regulates IL12b and IFNg and, under certain conditions, type I interferons. We have described the phenomena of innate immune memory in malaria, which is one part of an epigenetic process that may both protect the human host or, under certain conditions, might result in severe malaria (especially if accompanied by bacterial infection). More recently, we have identified several lncRNAs in malaria-stimulated phagocytes, many of which might regulate clinical disease. Thus, we have accomplished most of what we set out to do 5 years ago. In this renewal, we plan to focus on identifying the most basic methods by which the innate immune system is regulated in malaria by combining cell culture studies, in vitro mouse work with the analysis of patient samples. There are three Aims. The major hypothesis of the grant is that the innate immune response is highly regulated via epigenetic modifications of chromatin as well as at the transcriptional level. This regulation involves the interaction of lymphoid cells with phagocytes, resulting in innate immune training and a variety of epigenetic changes. The epigenetic changes involve the modification of chromatin, alterations of chromatin accessibility (Aim 1). In addition, inflammatory signals during malaria result in the generation of long non-coding RNAs including LUCAT-1 and LIMIT, whose roles we will explore in detail in vitro, in a LUCAT-1 KO mouse and in human clinical samples (Aim 2). Finally, we will define the role of a transcriptional regulator known as Cnbp, a nucleic acid binding protein that we initially thought to be a DNA sensor. Cnbp has proven to be involved in regulating IL12beta transcription and expression via its interaction with c-Rel and the IL12 promoter (Aim 3). In all of the Aims described briefly above, we will analyze leukocytes from febrile patients with malaria (both P. vivax and P falciparum) from our site in Porto Velho, Brazil. This grant is an ambitious project built upon the successful completion of two previously ambitious grants. Over the next funding cycle, we hope to contribute significantly more to our knowledge of innate immunity in malaria.