Novel mechanisms of regulatory T cell mediated suppression: a fundamental role for VPS34

调节性 T 细胞介导的抑制的新机制：VPS34 的基本作用

• 批准号: BB/T007826/1
• 负责人: Klaus Okkenhaug
• 金额: $ 81.35万
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FT007826%2F1
• 关键词: Novel; mechanisms; regulatory; cell; mediated

The immune system provides us with life-long protection against infectious agents. Specialised cells called T cells can both orchestrate the activities of other immune cells and kill infected cells directly. Remarkably, a small subset of T cells, called regulatory T cells (Tregs) are required to keep all the other T cells (conventional T cells, or Tcon) in check. Although Tregs comprise only about 1% of all the white blood cells, we cannot survive without them. Hence, children that lack a functional version of a gene called FOXP3 which is essential for Tregs do not live beyond two years, at which point their developing immune system turns against them, leading to a lethal syndrome known as IPEX. Mice that lack functional FOXP3 also die between 6 weeks because of an unrestrained immune attack against their organs and microorganisms in their skin and gut.What remains a puzzle is how such a small immune cell population can have such enormous importance for maintaining health. How do Tregs control the activity of the much more abundant Tcon? We have discovered that an enzyme called VPS34, originally identified in yeast, is essential for the function of Tregs. This is an important distinction from Foxp3, which is required for the development of Tregs. Therefore, FOXP3-deficient mice lack completely Tregs, whereas if we deleted the gene encoding VPS34, and that only in Tregs, we find normal numbers of Tregs in immune-related organs, but the mice nonetheless do not survive beyond 4-6 weeks. Normally, mice can live for 2-3 years. We therefore hypothesise that by gaining a better understanding of what VPS34 does in Tregs, we can also learn more about how Tregs work and answer the question about which function is absolutely essential for their ability to restrain Tcon.We will use several different experimental approaches to address this question. Most of the work will take advantage of a genetically modified mouse model in which the gene for VPS34 is deleted only in Tregs. Once mechanism through which Tregs are thought to work is by consuming certain stimulatory protein molecules so that they become unavailable for Tcon. We have already established that VPS34-deficient Tregs are still able to bind these proteins and internalise them. We will now follow what happens to these proteins once they have been transported inside the Tregs. Normally, they would be digested and degraded, but we suspect that this process is disrupted in Tregs lacking VPS34.We will also use mice in which only about half the Tregs lack VPS34. Such mice live a normal life span. We will challenge such mice by either implanting tumour cells under the skin or by infecting them with bacteria. This will stimulate both Tcon and Tregs to multiply and change from a resting state to a highly activated state. We can then compare Treg with or without VPS34 in the same mouse and ask: does whether lack of VPS34 interfere with the ability of Tregs to be activated and perhaps reach their full immune suppressive potential. Each T cell has about 6000-8000 different kinds of proteins. We have been able to measure these proteins in normal and VPS34-deficient Tregs. We can therefore determine whether without VPS34, you end up with more of some proteins, and less of others. Many of the proteins that are altered in absence of VPS34 are involved in cellular metabolism (i.e. processes that regulate how Tregs take up and use nutrients). We will determine if some of these metabolic activities affect Treg function and suppression. We believe that these complementary approaches will lead us to discover novel aspects of Treg function that might one day can be exploited for therapeutic purposes, for instance by designing drugs that either enhance or inhibit Treg function, and that could be used in the context of cancer or autoimmune diseases.

免疫系统为我们提供终身保护，使我们免受传染病的侵害。被称为T细胞的特殊细胞既能协调其他免疫细胞的活动，又能直接杀死被感染的细胞。值得注意的是，一小部分T细胞，称为调节性T细胞（Tregs），需要控制所有其他T细胞（传统T细胞，或Tcon）。虽然Tregs只占所有白细胞的1%左右，但没有它们我们就无法生存。因此，缺乏对Tregs至关重要的FOXP3基因的功能版本的儿童活不过两年，届时他们正在发育的免疫系统会开始对抗他们，导致一种名为IPEX的致命综合症。缺乏功能性FOXP3的小鼠也会在6周内死亡，因为它们的器官和皮肤和肠道中的微生物会受到不受限制的免疫攻击。如此少的免疫细胞群为何对维持健康具有如此巨大的重要性，这仍是一个谜。treg如何控制更丰富的Tcon的活动？我们发现一种叫做VPS34的酶，最初在酵母中发现，对Tregs的功能至关重要。这是与Foxp3的一个重要区别，Foxp3是treg发育所必需的。因此，foxp3缺陷小鼠完全缺乏Tregs，而如果我们删除编码VPS34的基因，并且只在Tregs中，我们发现免疫相关器官中有正常数量的Tregs，但小鼠仍然不能存活超过4-6周。正常情况下，老鼠可以活2-3年。因此，我们假设，通过更好地了解VPS34在Tregs中的作用，我们也可以更多地了解Tregs是如何工作的，并回答哪个功能对它们抑制Tcon的能力是绝对必要的。我们将使用几种不同的实验方法来解决这个问题。大部分工作将利用一种转基因小鼠模型，其中VPS34基因仅在treg中被删除。Tregs被认为起作用的一种机制是通过消耗某些刺激性蛋白质分子，使它们对Tcon无效。我们已经确定，缺乏vps34的treg仍然能够结合这些蛋白质并将其内化。我们现在将跟踪这些蛋白质在treg内部运输后发生的变化。正常情况下，它们会被消化和降解，但我们怀疑这一过程在缺乏VPS34的treg中被破坏。我们还将使用只有大约一半treg缺乏VPS34的小鼠。这样的老鼠寿命正常。我们将在这些老鼠的皮肤下植入肿瘤细胞，或者用细菌感染它们。这将刺激Tcon和Tregs的繁殖，并从静止状态转变为高度激活状态。然后，我们可以在同一只小鼠中比较有或没有VPS34的Treg，并问：缺乏VPS34是否会干扰Treg被激活的能力，并可能达到其全部免疫抑制潜力。每个T细胞大约有6000-8000种不同的蛋白质。我们已经能够在正常和缺乏vps34的treg中测量这些蛋白质。因此，我们可以确定，如果没有VPS34，你最终是否会有更多的某些蛋白质，而更少的其他蛋白质。在缺乏VPS34的情况下，许多被改变的蛋白质与细胞代谢有关（即调节treg如何吸收和利用营养物质的过程）。我们将确定这些代谢活动是否会影响Treg的功能和抑制。我们相信，这些互补的方法将引导我们发现Treg功能的新方面，也许有一天可以用于治疗目的，例如通过设计增强或抑制Treg功能的药物，可以用于癌症或自身免疫性疾病。

项目成果

A CRISPR screen targeting PI3K effectors identifies RASA3 as a negative regulator of LFA-1-mediated adhesion in T cells.

• DOI: 10.1126/scisignal.abl9169
• 发表时间: 2022-07-19
• 期刊: Science signaling
• 影响因子: 7.3

BACH2 restricts NK cell maturation and function, limiting immunity to cancer metastasis.

• DOI: 10.1084/jem.20211476
• 发表时间: 2022-12-05
• 期刊: JOURNAL OF EXPERIMENTAL MEDICINE
• 影响因子: 15.3
• 作者: Imianowski, Charlotte J.;Whiteside, Sarah K.;Lozano, Teresa;Evans, Alexander C.;Benson, Jayme D.;Courreges, Christina J. F.;Sadiyah, Firas;Lau, Colleen M.;Zandhuis, Nordin D.;Grant, Francis M.;Schuijs, Martijn J.;Vardaka, Panagiota;Kuo, Paula;Soilleux, Elizabeth J.;Yang, Jie;Sun, Joseph C.;Kurosaki, Tomohiro;Okkenhaug, Klaus;Halim, Timotheus Y. F.;Roychoudhuri, Rahul
• 通讯作者: Roychoudhuri, Rahul

Lack of phosphatidylinositol 3-kinase VPS34 in regulatory T cells leads to a fatal lymphoproliferative disorder without affecting their development

调节性 T 细胞中缺乏磷脂酰肌醇 3-激酶 VPS34 会导致致命的淋巴增殖性疾病，但不会影响其发育

• DOI: 10.1101/2024.01.08.574346
• 发表时间: 2024
• 作者: Courreges C