How does blocking inflammation enhance human cutaneous immunity during ageing in vivo?

虽然动物模型已被用于研究衰老过程中免疫功能下降的机制，但寿命差异和物种特异性差异为动物和人类之间的直接比较奠定了基础。此外，大多数人体研究都是在从血液中分离出来的白细胞上进行的，这可能无法反映组织中免疫反应期间发生的事件，类似于说在高速公路上行驶的人代表了生活在高速公路所服务的大城市中的人们。我们开发了一种新的方法来研究免疫反应期间人体组织中的白细胞。有了这些新方法，我们正试图理解为什么老年人对皮肤上的病原体反应不好，而这些病原体本应免疫，比如水痘病毒。这也可以解释为什么老年人更容易患皮肤癌和皮肤感染。在之前的一项研究中，我们有一个相当惊人的发现，老年人对水痘病毒的反应降低，并不是因为与年轻人相比，血液或皮肤中识别这种病毒的白细胞数量减少。相反，这种减少的反应是由于皮肤环境本身的变化，在那里我们发现了更多的背景炎症。我们在之前的研究中所做的是减少老年志愿者的炎症，使用葛兰素史克（GSK）的一种消炎药，看看这是否能增强他们皮肤对水痘病毒的反应。简而言之，我们能够做到这一点，我们已经发表了这项工作。然而，关键问题仍未得到解答，包括确定炎症最初来自何处，即皮肤中的哪些细胞产生了炎症？哪些细胞分泌蛋白质来招募炎症白细胞，称为单核细胞，到皮肤上？最后，这些单核细胞是如何在衰老过程中抑制免疫反应的？它们是单独工作还是与其他类型的细胞一起工作？我们将从皮肤中取出单个细胞，观察它们的基因表达，看看哪种细胞类型会产生炎症蛋白。我们将与剑桥大学的Menna Clatworthy教授一起进行这部分研究，他已经使用这些技术对人体组织进行了非常重要的研究。我们还将确定哪些细胞会分泌分子，将血液中的炎症单核细胞吸引到老年人的皮肤中。通过与纽卡斯尔的Muzlifah Haniffa教授合作，我们将能够开始生成老年人不同皮肤细胞的基因组图谱，以便与她已经分析过的年轻人进行比较。此外，我们将与类风湿关节炎患者关节炎症专家克里斯·巴克利教授合作，研究皮肤中的成纤维细胞是否与关节中的成纤维细胞有关。我们的初步结果表明了这种可能性，我们设想不同细胞类型之间可能的相互作用，以诱导我们在老年人皮肤中观察到的炎症。我们将与Clatworthy教授一起进行单细胞RNAseq分析，以解决这一问题。下一个问题是炎症是如何阻碍皮肤中常驻白细胞的功能的。我们将测试这是否是由于罪魁祸首细胞分泌因子的直接抑制作用，是否炎症使其他细胞踩刹车抑制免疫力，或者炎症是否召唤“军警”，即调节细胞，使皮肤中的一切平静下来。最后，我们将使用我们在之前的研究中生成的生物库样本来探索如何抑制炎症在旧的工作-它是否阻止炎症单核细胞的募集？阻止抑制细胞的产生或停止不同类型细胞之间的相互作用，打破它们之间的协同作用，从而扑灭炎症的火焰。

Although animal models have been used to investigate mechanisms for immune decline during ageing, differences in lifespan and species specific differences prelude direct comparison between animals and humans. Furthermore, most human studies are conducted on white cells isolated from the blood that may not reflect on events that take place during an immune response in the tissues, akin to saying that people travelling on a motorway are representative of the people living in big cities served by the motorway. We developed a new way of investigating white cells in human tissues during an immune response. With these new methods we are trying to understand why older humans respond badly to pathogens in the skin that they should be immune to, like the chickenpox virus. This may also explain why older individuals get more skin cancer and also more skin infections. In a previous study we made a rather surprising finding that the reduced response to the chickenpox virus in old people was not due to a decrease in the number of white cells that recognize this virus as compared to young subjects in either the blood or the skin. Instead this decreased response was due to changes in the skin environment itself, where we identified more background inflammation. What we did in this previous study was to reduce the inflammation in old volunteers, using an anti-inflammatory drug from Glaxo-Smith-Kline (GSK) to see if this could enhance their response in the skin to the chickenpox virus. In a nutshell, we were able to do so and we have published this work. However key questions remained unanswered including identifying where the inflammation was coming from in the first place i.e. which cells in the skin were making it? Which cells secreted proteins to recruit inflammatory white blood cells, called monocytes, to the skin? Finally how do these monocytes contribute to the inhibition of the immune response during ageing? Do they work alone or together with other cell types?We will take individual cells out of the skin and look at their gene expression to see which cell type makes the inflammatory proteins. We will do this part of the study with Professor Menna Clatworthy in Cambridge University who has already performed extremely important studies on human tissue using these techniques. We will also determine which cells secrete the molecules that attract inflammatory monocytes from the blood into the skin of older subjects. In collaboration with Professor Muzlifah Haniffa in Newcastle we will be able to begin to generate a genomic map of different skin cells from old people for comparison with young individuals that she has already analysed. Furthermore in collaboration with Prof. Chris Buckley who is an expert on inflammation in joints in patient with Rheumatoid Arthritis, we will investigate if cells called fibroblasts in the skin are involved, like they are in the joints. This possibility is suggested by our preliminary results and we envisage possible interactions between different cell types to induce the inflammation we observe in the skin of older humans. This will be addressed with the single cell RNAseq analyses that we will perform with Prof. Clatworthy. The next question is how the inflammation blocks the function of the resident white cells in the skin. We will test if it is due to a direct inhibitory effect of secreted factors from the culprit cell, if the inflammation makes other cells turn on the brakes to inhibit immunity or if the inflammation calls in the "military police" known as regulatory cells that calms everything down in the skin. Finally we will used bio-banked samples that we generated in a previous study to probe how inhibiting inflammation in the old works -does it prevent recruitment of inflammatory monocytes? Prevent the generation of inhibitory cells or stop the interaction between different cell types, breaking the synergy between them and thus puts out the fire of inflammation.