Novel insights into the regulation of CCR7 receptor expression in immune cells

toll样受体（Toll-like receptor， TLR）识别微生物分子，通过激活NF-kB调控细胞因子和趋化因子的表达，导致炎症反应的发生。病原体引导的TLR激活提供了炎症细胞快速募集到感染部位并激活它们以诱导抗菌功能库。******直到最近，已知只有先天免疫细胞，如巨噬细胞和dc，以及粘膜表面的上皮细胞表达功能上的tlr。然而，现在许多研究已经报道了淋巴细胞中与生理相关的信号敏感的tlr。趋化因子CCL19和CCL21是CCR7的天然配体，在免疫细胞向淋巴结迁移中起重要作用。由于TLR激活和炎症是病毒和细菌感染的标志，因此确定它们是否可以调节ccr7依赖性迁移，以便更好地了解导致T细胞传播的因素至关重要。在本研究项目中，我们寻求在T细胞中TLR激活后导致CCR7表达的分子和细胞事件获得新的见解。基于我们激动人心的初步结果，在这个五年的研究计划中提出了以下具体目标：******AIM 1。目的：探讨TLR激活是否能调节T细胞中CCR7的表达和功能。***在本实验中，我们将通过实时RT-PCR监测TLR激活和T细胞炎症后CCR7 mRNA的诱导情况。使用针对CCR7的特异性抗体进行FACS分析将确认CCR7在细胞表面的表达。受体的功能将通过趋化性试验来验证。* * * * * *的目标2。确定TLR激动剂激活的T细胞中导致CCR7表达调节的转录因子和信号模块。***我们建议阐明tlr诱导CCR7表达的信号事件和转录因子。首先，我们将使用包含CCR7启动子区域全长或缺失版本的分子结构来研究启动子活性。接下来，我们将利用电泳迁移和染色质免疫沉淀试验，探索tlr刺激的T细胞中CCR7表达所需的转录因子和信号事件。* * * * * *的目标3。在小鼠模型中确定观察到的T细胞中CCR7表达的调节是否影响迁移。***具有人源化免疫系统的小鼠是获得对免疫系统理解的重要见解的合适动物模型。在这里，我们将使用这样的模型来研究我们假设的生理学相关性。******这一创新的研究项目将首次为理解T细胞在响应CCL19和CCL21（两种CCR7天然配体）感染时的迁移提供新的见解

Toll-like receptors (TLR) recognize microbial molecules, which results in the development of inflammatory reactions caused by the activation of the NF-kB regulating expression of cytokines and chemokines. Pathogen-led TLR activation provides rapid recruitment of inflammatory cells to the site of infection and activates them to induce an arsenal of antimicrobial functions.******Until recently, only innate immune cells, such as macrophages and DCs, and epithelial cells lining mucosal surfaces were known to express functionally competent TLRs. However, many studies have now reported physiologically relevant signal-competent TLRs in lymphocytes. Chemokines CCL19 and CCL21, the natural ligands of CCR7 are important for immune cell migration to lymph nodes. Since TLR activation and inflammation are hallmarks of viral and bacterial infections, it is of vital importance to determine whether they can regulate CCR7-dependent migration in order to better understand factors leading to T cell dissemination. In this research program, we seek to gain novel insights into the molecular and cellular events leading to CCR7 expression following TLR activation in T cells. Based on our exciting preliminary results, the following specific aims are proposed in this five-years research program:******AIM 1. To establish whether TLR activation modulate CCR7 expression and functionality in T cells.***In this objective, we will monitor CCR7 mRNA induction following TLR activation and inflammation of T cells by real-time RT-PCR. FACS analysis using a specific antibody against CCR7 will confirm the expression of CCR7 at cell surface. The functionality of the receptors will be verified by chemotaxis assays.******AIM 2. To determine transcription factors and signaling modules elicited in T cells activated by TLR agonists that lead to the modulation of CCR7 expression.***We propose to elucidate signaling events and transcription factors essential for the TLR-induced expression of CCR7. First, we will study the promoter activity using molecular constructs containing the full-length or deleted versions of the promoter region of CCR7. Next using electrophoretic mobility shift and chromatin immunoprecipitation assays, we will explore the transcription factors as well as the signaling events required for CCR7 expression in TLR-stimulated T cells.******AIM 3. To determine whether the observed modulation in CCR7 expression in T cells affects migration in a mouse model.***Mice that have an humanized immune system represent a suitable animal model to gain important insights in the comprehension of the immune system. Here, we will use such model to study the physiological relevance of our hypothesis.******This innovative research program will give for the first time, novel insights into the comprehension of T cell migration in response to infections in response to CCL19 and CCL21, two CCR7 natural ligands.**