Influence of Chemokine Receptors on T Cell Cytokine Profiles in Skin

描述(由申请人提供)：致力于皮肤免疫学的抗原经验的CD4T细胞亚群表达E-选择素的碳水化合物配体(E-LIG)以及趋化因子受体CCR4。我们已经开发了一种体内试验，在这种试验中，单纯的TCR转基因OT-II细胞在局部应用抗原的情况下会发育成皮肤归巢T细胞。我们已经成功地利用这种方法研究了幼稚细胞分化为皮肤记忆细胞所需的条件，并探索了CCR4在T细胞从血液进入皮肤组织的过程中的作用。尽管CCR4缺陷的OT-II细胞进入发炎皮肤的能力严重受损，但它们似乎可以在皮肤引流淋巴结(LN)内正常复制，以响应抗原。该检测采用抗原/佐剂组合，创造牛皮癣样的细胞因子环境，产生抗原特异性T细胞群，表达IFN3或IL17，但不表达常见的TH2相关细胞因子。CCR4缺陷的T细胞在同一检测中不产生IL-17，我们发现IL-17是正常皮肤印迹E-lighti细胞产生的主要细胞因子。相反，对于CCR4缺陷的细胞，IFN3的表达显著增加。据我们所知，这是第一次观察到趋化因子受体的功能性缺失会改变T细胞对特定抗原的反应。在这个项目中，我们建议更全面地探索这一新发现，并测试几个关于CCR4最终影响细胞因子谱的机制的假设。我们建议评估比我们初步工作中检测到的更广泛种类的细胞因子的表达，以探索CCR4影响这一过程的全部程度。我们还将寻找与不同TH谱系相关的转录因子表达的差异。我们将尝试区分CCR4是否通过将细胞引导到允许IL17诱导的皮肤内微环境来影响细胞因子谱，或者CCR4信号是否直接影响印记。此外，我们将使用不同的TLR配体作为佐剂来改变我们的模型中产生的细胞因子反应，并评估CCR4在这些改变的条件下的影响。最后，我们将评估另外两个皮肤相关趋化因子受体CCR6和CCR10的能力，以了解它们在本实验中影响TH细胞因子谱的潜力。

DESCRIPTION (provided by applicant): The subset of antigen-experienced CD4 T cells dedicated to skin immunology express the carbohydrate ligand for E-selectin (E-lig) along with chemokine receptor CCR4. We have developed an in vivo assay in which naive TCR-transgenic OT-II cells develop into skin-homing T cells in response to topically applied antigen. We have successfully used this assay to investigate the conditions required for naive cells to differentiate in to cutaneous memory cells, and to explore the role of CCR4 in the process by which T cells enter cutaneous tissue from the blood. Although CCR4-deficient OT-II cells are severely impaired in their ability to enter inflamed skin, they appear to replicate normally within the skin-draining lymph nodes (LN) in response to antigen. This assay employs an antigen/adjuvant combination that creates a psoriasis-like cytokine environment, generating populations of antigen-specific T cells that express IFN3 or IL17, but not common TH2-associated cytokines. CCR4-deficient T cells in this same assay did not produce IL-17, which we found to be the dominant cytokine produced by normal skin-imprinted E-lighi cells. Conversely, IFN3 expression was significantly increased for CCR4-deficient cells. To our knowledge, this is the first case in which the functional absence of a chemokine receptor has been observed to alter the TH cytokine profile of T cells responding to a given antigen. In this project, we propose to more fully explore this novel discovery, and test several hypotheses regarding the mechanism by which CCR4 ultimately influences the cytokine profile. We propose to assess expression of a wider variety of cytokines than those examined in our preliminary work to probe the full extent to which CCR4 influences this process. We will also look for differences in the expression of transcription factors associated with the various TH lineages. We will attempt to distinguish whether CCR4 influences the cytokine profile by guiding cells to a microenvironment within skin that is permissive for IL17 induction, or whether CCR4 signals directly influence TH imprinting. Furthermore, we will use various TLR ligands as adjuvants to alter the cytokine responses produced in our model, and assess the influence of CCR4 under these altered conditions. Finally, we will assess the ability of two other skin-associated chemokine receptors, CCR6 and CCR10, for their own potential to influence TH cytokine profiles in this assay.