Epithelial Cell TLRs in Disease Susceptibility

描述（由申请人提供）：人类发展牙龈炎和牙周炎是对微生物牙菌斑产生的挑战的反应。个体对牙龈炎（浅表炎症）和牙周炎（引起骨和牙齿脱落的广泛炎症）的易感性各不相同。牙周病的病因尚不完全清楚；然而，人们普遍认为，人类宿主对微生物斑块反应的差异与宿主的先天、炎症或免疫防御系统有关。单核苷酸多态性（SNPs）存在于人类基因中，编码许多与宿主-微生物相互作用相关的分子。牙周炎症（牙龈炎和牙周炎）始于细菌通过受体（包括toll样受体（TLRs））扰乱上皮细胞。我们的初步数据表明，个体对细菌和细胞因子扰动产生的促炎细胞因子和趋化因子是不同的，这些差异可能与携带特定的TLR4多态性有关。我们的一般假设是，牙龈上皮细胞对外来挑战的个体反应特征与其细胞TLR基因型有关，TLR基因型影响牙龈炎和牙周炎的易感性。因此，我们将利用多个原代人牙龈上皮细胞（HGECs），临床研究和基因型和表型分析来解决以下目标。第一个目标是利用qPCR、基因表达谱、蛋白质测定和免疫反应性，从分子上表征hgcs中TLR表达的患者间差异，并将其与TLR基因型联系起来。其次，基因修饰的hgec的功能分析（使用siRNA敲除和过表达）将阐明TLR4和Asp299Gly以及其他snp在上皮LPS低反应性中的作用。第三，我们的目标是通过临床确定TLR4多态性和低反应性是否与实验性牙龈炎的严重程度相关，以及它们是否可以区分牙周炎病例和对照组来翻译这项工作。最后，我们的目标是挑战hgcs和其他细胞类型，单核细胞，肠道上皮细胞和内皮细胞，以评估与TLR4相关疾病（如炎症性肠病，动脉粥样硬化和哮喘）病因病理学相关的LPS反应性。反应差异的表征和相关snp的确定可能导致一系列感染性和炎症性疾病的新疗法或诊断。

DESCRIPTION (provided by applicant): Humans develop gingivitis and periodontitis in response to the challenges produced by microbial dental plaque. Individuals vary in their susceptibility to both gingivitis (superficial inflammation) and periodontitis (extensive inflammation causing bone and tooth loss). The etiology of periodontal disease is not fully understood; however, it is accepted that variance in the human host response to microbial plaque will relate to the host's innate, inflammatory or immune defense systems. Single nucleotide polymorphisms (SNPs) exist in the human genes encoding many molecules pertinent to the host-microbe interaction. Periodontal inflammation (gingivitis and periodontitis) begins with the perturbation of the epithelial cells by bacteria via receptors, including Toll-like Receptors (TLRs). Our preliminary data indicates that the pro-inflammatory cytokines and chemokines produced in response to bacterial and cytokine perturbations differ between individuals and these differences may relate to carriage of a specific TLR4 polymorphism. Our general hypothesis is that individual response characteristics of gingival epithelial cells to foreign challenges, relate to their cellular TLR genotype which influences susceptibility to gingivitis and periodontitis. Thus we will address the following aims utilizing multiple primary human gingival epithelial cells (HGECs), clinical studies and genotype and phenotype analyses. The first aim is to characterize molecularly the inter-patient differences in TLR expression in HGECs using qPCR, gene expression profiling, protein assays and immunoreactivity and to correlate this to the TLR genotype. Secondly, functional analysis of genetically- modified HGECs (using siRNA knock-downs and over-expression) will elucidate the role of TLR4 and the Asp299Gly and other SNPs in epithelial LPS hypo-responsiveness. Thirdly, we aim to translate this work by determining clinically if TLR4 polymorphisms and hypo-responsiveness correlate with the severity of experimental gingivitis and if they can differentiate periodontitis cases and controls. Finally, we aim to challenge HGECs and other cell types, monocytes, gut epithelia and endothelial cells to assess LPS responsiveness relevant to the etiopathology of TLR4 associated diseases such as inflammatory bowel disease, atheroma and asthma. Characterization of response differences and determination of related SNPs may lead to new therapeutics or diagnostics in a range of infectious and inflammatory diseases.