权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Calreticulin and other candidate Alarmins and Opsonins from Microglia

钙网蛋白和其他来自小胶质细胞的候选警报素和调理素

基本信息

批准号：
2273693
负责人：
金额：
--
依托单位：
University of Cambridge
依托单位国家：
英国
项目类别：
Studentship
财政年份：
2019
资助国家：
英国
起止时间：
2019 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=studentship-2273693
关键词：
Calreticulin other candidate Alarmins Opsonins

项目摘要

PhD project strategic theme: Biosciences for an integrated understanding of healthAlarmins are soluble molecules released from damaged cells that promote the non-infectious inflammatory activation of immune cells. This activation is important for initiating the early stage innate immune response to tissue damage or disease. Calreticulin, an intracellular chaperone of the endoplasmic reticulum, is a candidate alarmin to microglia - the resident macrophage of the brain. During the rotation project, it was found that calreticulin was released from damaged cells, chemoattracted microglia in vitro, and stimulated their release of tumour necrosis factor-alpha and interleukin-6; cytokines associated with an inflammatory phenotype. Thus, calreticulin may act as an intermediate between tissue damage in the brain and the microglial immune response to that damage.The PhD project would build on these findings. Firstly, by understanding the mechanistic pathways involved, including the mechanism of cellular release, and the receptor (or receptors) on microglia for calreticulin and downstream signalling. Secondly, the consequences for microglia in terms of the inflammatory profile and neurotoxicity. Thirdly, it will be tested whether calreticulin acts as an opsonin for microglial phagocytosis of synapses, myelin and neurons. Fourthly, if calreticulin acts as an opsonin, then whether this promotes antigen presentation to T cells will be determined. To determine whether calreticulin release occurs in vivo, calreticulin and cytokine levels will be measured in the cerebrospinal fluid of human patients that have either suffered from traumatic brain injury or not. Similarly, calreticulin and cytokine levels will be measured in the cerebrospinal fluid of rats and mice from various disease models, including brain trauma. Samples would be acquired across multiple acquisition timepoints post-injury to better elucidate the physiological pattern of calreticulin release and relate this to the inflammatory profile. As the microglial immune response is a multi-layered process involving numerous complexes and molecules, further to calreticulin other soluble mediators will be investigated for their potential as microglial alarmins and/or opsonins. The secretome of primary microglia under various conditions will be acquired, purified, and then fragmented into identifiable proteins by mass spectrometry. Candidate proteins will then be assessed for their ability to act as alarmins or opsonins for microglia as above. Concurrently with this project, the microglial receptor P2Y6 will be assessed to test whether it has a role in developmental synaptic phagocytosis (pruning). Too little synaptic pruning is implicated in autism, and too much pruning in schizophrenia. Preliminary research in the Brown lab indicates that the P2Y6 receptor may be required for microglial phagocytosis of synapses; and behavioural testing of 3-4 month old P2Y6-/- mice indicates they have memory deficits. This project will further test whether one-month-old P2Y6-/- mice have social deficits and/or increased synaptic density, and whether this is due to reduced microglial phagocytosis of synapses.

博士项目战略主题：Alarmins是从受损细胞释放的可溶性分子，可促进免疫细胞的非感染性炎症激活。这种激活对于启动对组织损伤或疾病的早期先天免疫应答是重要的。钙网蛋白是内质网的细胞内伴侣，是小胶质细胞（大脑中的巨噬细胞）的候选警报素。在旋转项目期间，发现钙网蛋白从受损细胞中释放，体外化学吸引小胶质细胞，并刺激其释放肿瘤坏死因子-α和白细胞介素-6;与炎症表型相关的细胞因子。因此，钙网蛋白可能是大脑组织损伤和小胶质细胞对损伤的免疫反应之间的中间体，博士项目将建立在这些发现的基础上。首先，通过了解所涉及的机制途径，包括细胞释放机制，以及钙网蛋白和下游信号的小胶质细胞上的受体（或受体）。其次，小胶质细胞在炎症特征和神经毒性方面的后果。第三，将测试钙网蛋白是否充当突触、髓鞘和神经元的小胶质细胞吞噬作用的调理素。第四，如果钙网蛋白作为调理素，那么这是否促进抗原呈递给T细胞将被确定。为了确定钙网蛋白释放是否在体内发生，将在患有或未患有创伤性脑损伤的人类患者的脑脊液中测量钙网蛋白和细胞因子水平。类似地，将在来自各种疾病模型（包括脑创伤）的大鼠和小鼠的脑脊液中测量钙网蛋白和细胞因子水平。将在损伤后的多个采集时间点采集样品，以更好地阐明钙网蛋白释放的生理模式并将其与炎症特征相关联。由于小胶质细胞免疫应答是一个涉及许多复合物和分子的多层过程，除了钙网蛋白外，还将研究其他可溶性介质作为小胶质细胞警报素和/或调理素的潜力。在各种条件下的原代小胶质细胞的分泌组将被获取、纯化，然后通过质谱法片段化为可识别的蛋白质。然后评估候选蛋白质作为小胶质细胞的警报素或调理素的能力，如上所述。与此同时，小胶质细胞受体P2 Y 6将被评估，以测试它是否在发育突触吞噬作用（修剪）中发挥作用。突触修剪太少与自闭症有关，修剪太多与精神分裂症有关。布朗实验室的初步研究表明，P2 Y 6受体可能是突触的小胶质细胞吞噬作用所必需的; 3-4个月大的P2 Y 6-/-小鼠的行为测试表明它们有记忆缺陷。该项目将进一步测试一个月大的P2 Y 6-/-小鼠是否有社会缺陷和/或突触密度增加，以及这是否是由于突触的小胶质细胞吞噬作用减少。