Mast cells in skin innate immune defense

摘要 我们已经证明，进入皮肤的肥大细胞会因接触真皮而改变表型。 成纤维细胞(DF)。在皮肤中，肥大细胞(MC)下调其TLR2并增加基因的表达 这下调了已知的炎症途径--核因子B的表达。这有助于维持皮肤的动态平衡 并使肥大细胞对共生菌具有耐受性。我们发现DFS分泌的一种特殊蛋白DKK2， 通过增加TnFAIP3(A20)和NFKBIA的基因表达来调节HUMC的NF-B途径 HuMCs。这种调节导致对共生细菌的炎症反应减少。在这 建议，我们将阐明DF-MC信号的机制，它诱导MC皮肤耐受表型。 这是皮肤炎症和特应性皮炎(AD)的一个重要机制。我们将向大家介绍 初步数据显示，在AD中，DFS未能维持人MC(HUMC)对共生菌的耐受性 这使得HUMC能够释放促炎细胞因子。认为炎症性疾病会发展成 因为MC的耐受性被打破，代表着科学范式的转变。这项工作将确定这些机制 深入研究HuMCs在建立和打破对皮肤丰富环境的耐受性方面的作用。 我们提出以下建议： 1.确定人单核细胞中是否需要TNFAIP3(A20)和NFKBIA来预防 对共生上清液的促炎细胞因子反应(耐受性)。在这个目标1中 提案，我们将使用各种结构、生物物理、生化和功能分析来 确定真皮MC如何与DFS协作。更具体地说，我们将分析MC表达式 在与NF-B相关的基因中，TNFAIP3(A20)和NFKBIA以及与先天相关的受体 真皮HuMCs的免疫系统。 2.证实DKK2可诱导DFS对MC的耐受 在目标2中，我们将确定是否需要DF DKK2来诱导HUMC对共生的耐受 培养上清，以及不同的DF亚群在诱导人脐血细胞耐受能力上是否存在差异。 3.确认DF诱导的MC对共生菌的耐受性是抑制 人类皮肤发炎。 在这项提案的目标3中，我们将研究HuMC未能保持容忍的后果 以及它们在皮肤炎症中的作用，特别是在特应性皮炎皮肤中。

ABSTRACT We have demonstrated that mast cells entering the skin change phenotype triggered by contact with dermal fibroblasts (DF). In the skin, Mast Cells (MCs) down regulate their TLR2 and increase the expression of genes that downregulate the NFB, a known inflammatory pathway. This contributes to maintaining skin homeostasis and makes mast cell tolerant to commensal bacteria. We found that DKK2, a specific protein secreted by DFs, modulates the huMC NF–B pathway, by increasing gene expression of TNFAIP3 (A20) and NFKBIA in huMCs. This modulation results in a decreased inflammatory response to commensal bacteria. In this proposal, we will clarify the mechanisms of DF - MC signaling, which induces a MC skin tolerant phenotype. This is an important mechanism for skin inflammation and atopic dermatitis (AD) in particular. We will present preliminary data that show that in AD, DFs fail to maintain human MC (huMC) tolerance to commensal bacteria which allows huMC to release proinflammatory cytokines. The idea that inflammatory diseases develop because MC tolerance is broken represents a shift in science paradigm. This work will identify the mechanisms underlying the roles of huMCs in building and breaking tolerance to the skin’s rich environment. We propose the followings: 1. To determine whether TNFAIP3 (A20) and NFKBIA in human MCs are required for preventing proinflammatory interleukin responses (tolerance) to commensal supernatant. In Aim 1 of this proposal, we will use a variety of structural, biophysical, biochemical, and functional assays to determine how dermal MCs collaborate with DFs. More specifically, we will analyze the MC expression of the NF–B related genes, TNFAIP3 (A20) and NFKBIA, as well as receptors related to the innate immune system in dermal huMCs. 2. To confirm that MC tolerance can be induced by DKK2 from DFs In Aim 2, we will determine whether DF DKK2 is required for inducing huMC tolerance to commensal supernatant and whether different DF sub-populations vary in their ability to induce tolerance in huMCs. 3. To confirm that DF-induced MC tolerance to commensal bacteria is critical for suppressing human skin inflammation. In Aim 3 of this proposal we will look at the consequences of the failure of huMCs to maintain tolerance and their role in skin inflammation, specifically in Atopic Dermatitis skin.