Regulating Cathelicidin Expression for Disease Therapy

描述(由申请人提供)：由抗生素耐药细菌感染和潜在的败血症是一个主要的健康问题。抗菌肽(AMP)如环磷酰胺(CAMP)和防御素(Defensins)作为潜在的杀菌剂、抗内毒素药物和炎症调节剂，以及其他潜在用途，正引起人们的极大兴趣。然而，调控cAMP表达的机制在很大程度上是未知的。这项研究的核心假设是，CCAAT/增强子结合蛋白(C/EBP)、Ets/PU.1、CREB/ATF和类固醇/甲状腺激素受体家族的转录因子(TF)控制着造血和上皮组织中cAMP的结构性和诱导性表达。我们提出了一项旨在实现三个特定目标的研究：[1]确定髓系和上皮细胞中调节cAMP基因转录的转录因子；[2a]确定维生素DS在不同细胞类型和特应性皮炎中诱导cAMP的程度；[2b]确定维甲酸和维生素D3协同激活人cAMP基因表达的机制；[2c]发现调节cAMP基因表达的新型小分子；[3]阐明维生素D3调节cAMP基因表达的生物学意义和潜在的治疗益处。特定的目标1和2将对髓系和上皮室中cAMP基因的转录调控进行全面评估，并确定单独或与维生素D3结合可能被证明具有治疗作用的其他化合物。具体目标3将描述维生素D对抗微生物基因调控的进化和生物学重要性，并将使用平行的体外和体内小鼠模型，这些模型利用一种强大的遗传方法来关键地研究维生素D3如何调节cAMP的表达，以应对微生物入侵或病原体衍生分子的挑战。这些特定目的的实现将提供对cAMP基因转录调控的全面了解，并证明维生素D3介导的抗菌肽调控的生物学重要性。这一认识将导致开发外部操纵内源性cAMP表达的方法，以实现对人类疾病的系统性和局部性治疗效益。

DESCRIPTION (provided by applicant): Infections by antibiotic resistant bacteria and the potential for sepsis are a major health concern. Antimicrobial peptides (AMPs) like cathelicidins (CAMP) and defensins are generating considerable interest for therapeutic use as potential bactericidals, anti-LPS drugs and modulators of inflammation, and other potential uses. However, the mechanisms governing CAMP expression are largely unknown. The central hypothesis driving the proposed research is that transcription factors (TFs) from the CCAAT/enhancer binding protein (C/EBP), ETS/PU.1, CREB/ATF and the steroid/thyroid hormone receptor families control constitutive and inducible expression of CAMP in hematopoietic and epithelial tissues. We propose an investigation directed towards achieving 3 Specific Aims: [1] Identify the TFs in myeloid and epithelial cells that regulate CAMP gene transcription; [2a] Determine extent of vitamin DS-mediated induction of CAMP in various human cell types and atopic dermatitis; [2b] Identify mechanism of synergistic activation of human CAMP gene expression by retinoids and vitamin D3; [2c] Discover novel small molecules that regulate CAMP gene expression; [3] Elucidate the biological importance and potential therapeutic benefits of vitamin D3 regulation of CAMP gene expression. Specific Aims 1 and 2 will generate a comprehensive assessment of the transcriptional regulation of the CAMP gene in the myeloid and epithelial compartments and identify additional compounds that either alone or in combination with vitamin D3 may prove therapeutically useful. Specific Aim 3 will characterize the evolutionary and biological importance of antimicrobial gene regulation by vitamin D and will use parallel in vitro and in vivo mouse models that exploit a powerful genetic approach to critically examine how vitamin D3 regulates expression of CAMP in response to microbial invasion or challenge with pathogen-derived molecules. Achievement of these specific aims will provide a comprehensive knowledge of the transcriptional regulation of the CAMP gene and demonstrate the biological importance of vitamin D3-mediated regulation of antimicrobial peptides. This knowledge will lead to the development of approaches for extrinsically manipulating endogenous CAMP expression for systemic and localized therapeutic benefit of human diseases.