Innate Immune Response Genes and P. Gingivalis

描述：牙周病与定植于龈下区域的致病菌有关。由天然免疫系统细胞介导的炎症反应是牙周病的关键决定因素。其中最突出的细菌之一是牙龈卟啉单胞菌(Pg)。牙周炎被认为是由于天然免疫系统的细胞，即单核/巨噬细胞和粒细胞的反应而引起的宿主组织损伤。近年来，Toll样受体(TLR)迅速成为天然免疫系统识别微生物病原体的主要途径。TLR的激活需要TLR近端的一系列细胞内适配子蛋白，包括MyD88、TRAF6、MD-2和TRAM。最近，我们已经确定了一系列进一步调节TLR信号的蛋白质，称为卡特彼勒蛋白。其中有两个是新的核因子-kappaB、AP-1和细胞因子产生的抑制剂，Monch-1和CIAS/Cryopyrin。然而，这两个蛋白的功能依赖于修饰蛋白ASC(带有卡片的凋亡斑点蛋白)，该修饰蛋白颠覆了它们的负功能，并导致促炎表型。这项应用的目的是了解TLRs、它们的接头、毛虫蛋白和ASC在PG感染中的作用。我们将比较PG和E.Coli对PG的宿主反应，以评估PG是否能引起独特的宿主反应。因此，我们的目标是：1)确定哪些TLR分子及其下游介体对于宿主对PG和E.Coli的反应是重要的信号。这将通过使用RNA干扰技术靶向人类TLRs和TLR适配器基因来实现；我们将确定移除这些基因是否会导致宿主对PG的反应发生变化，这是通过细胞因子反应和基因表达谱来衡量的。2)缺乏Monch-1的单核/巨噬细胞系将进行类似于1)的测试。由于Monch-1似乎是NF-kB和AP-1途径的抑制分子，并且可以调节细胞因子的产生，我们推测Monch-1的缺失可能有利于更有力的促炎反应。3)缺乏或过度表达炎症反应的另一种调节因子CIAS/低温比林的细胞株将接受类似的测试。4)ASC降低的细胞系也将被测试。由于ASC可以克服Monch-1和CIAS的负调节作用，因此ASC可能会增强对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.