Innate Immune Response Genes and P. Gingivalis

描述：牙周病与牙龈下定植的致病菌有关。由先天免疫系统细胞介导的炎症反应是牙周病的关键决定因素。其中最突出的细菌是牙龈卟啉单胞菌（Pg）。牙周炎被认为是由先天免疫系统细胞（即单核/巨噬细胞和粒细胞）的反应引起的宿主组织损伤引起的。近年来，toll样受体（TLR）迅速成为先天免疫系统识别微生物病原体的主要途径。TLR的激活需要一系列靠近TLR的细胞内接头蛋白，包括MyD88、TRAF6、MD-2和TRAM。最近，我们已经确定了一个蛋白家族，进一步调节TLR信号，称为CATERPILLER蛋白。其中两个，Monarch-1和CIAS/cryopyrin，是NF-kappaB， AP-1和细胞因子产生的新型抑制剂。然而，这两种蛋白的功能依赖于修饰蛋白ASC（凋亡斑点蛋白与CARD），这破坏了它们的负功能，并导致促炎表型。本应用程序的目的是了解在Pg感染中tlr、它们的接头、CATERPILLER蛋白和ASC的作用。将比较宿主对Pg和大肠杆菌的反应，以评估Pg是否引起独特的宿主反应。因此，目的是：1)确定哪些TLR分子及其下游介质在宿主对Pg和大肠杆菌的反应中起重要作用。这将通过使用RNA干扰技术靶向人类TLR和TLR适配基因来实现；我们将通过细胞因子反应和基因表达谱来确定这些基因的去除是否会导致宿主对Pg反应的改变。2)单核/巨噬细胞系缺乏君主-1将进行与1)类似的测试。由于monarch1似乎是NF-kB和AP-1通路的抑制分子，并且可以调节细胞因子的产生，我们假设monarch1的缺失可能有利于更强烈的促炎反应。3)缺乏或过表达CIAS/cryopyrin（另一种炎症反应调节剂）的细胞系将进行类似的测试。4) ASC降低的细胞系也将进行测试。由于ASC可以克服monarch1和CIAS的负调控功能，因此ASC可以增强对Pg的免疫应答，从而抑制感染。

DESCRIPTION: Periodontal diseases are associated with pathogenic bacteria which colonize the subgingival area. Inflammatory responses mediated by cells of the innate immune system are critical determinants of periodontal diseases. One of the most prominent bacteria is Porphyromonas gingivalis (Pg). Periodontitis is thought to result from host tissue injury caused by the response of cells of the innate immune system, namely monocytes/macrophages and granulocytes. In recent years, the Toll-like receptors (TLR) have rapidly emerged as a dominant route by which the innate immune system recognizes microbial pathogens. TLR activation requires a host of intracellular adaptor proteins proximal to the TLRs, including MyD88, TRAF6, MD-2 and TRAM. More recently, we have identified a family of proteins that further modulate TLR signaling, called the CATERPILLER proteins. Two of these, Monarch-1 and CIAS/cryopyrin, are novel inhibitors of NF-kappaB, AP-1 and cytokine production. Nevertheless, the function of these two proteins is dependent on a modifier protein ASC (Apoptotic Speck protein with a CARD), which subverts their negative function, and causes a pro-inflammatory phenotype. The purpose of this application is to understand the roles of TLRs, their adaptors, CATERPILLER proteins and ASC during a Pg infection. Comparisons of host response to Pg vs. E. coli will be made to assess if Pg elicits unique host responses. Accordingly, the Aims are: 1) to determine which TLR molecules and their downstream mediators are important to signal host responses to Pg vs. E. coli. This will be achieved by using RNA interference technology to target human TLRs and TLR adaptor genes; we will determine if the removal of these genes causes alterations in host response to Pg as measured by cytokine responses, and by gene expression profile. 2) Monocytic/macrophage cell lines that lack Monarch-1 will be similarly tested as in 1). Since Monarch-1 appears to be an inhibitory molecule of the NF-kB and AP-1 pathway, and can modulate cytokine production, we posit that the absence of Monarch-1 may favor a more vigorous pro-inflammatory response. 3) Cell lines that lack or overexpress CIAS/cryopyrin, another modulator of inflammatory response will be similarly tested. 4) Cell lines with reduced ASC will also be tested. Since ASC can overcome the negative regulatory function of Monarch-1 and CIAS, ASC may enhance immune response to Pg to contain the infection.