Mechanisms of NF-kappaB Activation in T Lymphocytes

T 淋巴细胞中 NF-κB 激活的机制

基本信息

批准号：
7435307
负责人：
Zhijian J Chen
金额：
$ 32.65万
依托单位：
UT SOUTHWESTERN MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2004
资助国家：
美国
起止时间：
2004-06-01 至 2010-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7435307
关键词：
Address Antigens BCL10 gene Cell Extracts Cell Nucleus Cell membrane Cell physiology Cell-Free System Cells Complex Enzymes Essential Genes Family Fractionation Gene Expression Goals Grant Hand I Kappa B-Alpha IkappaB kinase Immune System Diseases Immune response Immunity In Vitro Interleukin-1 Investigation Knowledge Lead Left Link Lysine MAP3K7 gene Mediating Membrane Microdomains Multienzyme Complexes NF-kappa B Natural Immunity Pathway interactions Phosphorylation Physiological Play Polyubiquitin Polyubiquitination Principal Investigator Protein Kinase Protein Kinase C Proteins RNA Interference Receptor Activation Receptor Signaling Recombinant Proteins Recombinants Regulation Research Role Series Signal Pathway Signal Transduction Signaling Molecule T-Cell Receptor T-Lymphocyte TNF receptor-associated factor 6 TRAF6 gene Tertiary Protein Structure Testing Toll-like receptors Ubiquitin Ubiquitin-Conjugating Enzymes Ubiquitination United States National Institutes of Health cytokine domain mapping genetic regulatory protein human BCL10 protein human disease inhibitor/antagonist isopeptidase membrane-associated guanylate kinase mucosa-associated lymphoid tissue lymphoma multicatalytic endopeptidase complex novel programs protein degradation reconstitution research study response ubiquitin ligase

项目摘要

DESCRIPTION (provided by applicant): NF-KappaB plays a pivotal role in the activation of T lymphocytes during immune responses. Upon engagement of T cell receptor (TCR) with a foreign antigen, a signal transduction cascade is activated, culminating in the activation of NFKB, which controls the expression of genes essential for the proliferation and function of T cells. While much is known about the pathways of NF-KB activation by proinflammatory cytokines, the mechanism by which NF-kappaB is activated by TCR is not well understood. A key regulator of NF-KappaB pathway is the IKappaB kinase (IKK) complex, which phosphorylates the NF-kappaB inhibitor IKappaB and targets this inhibitor for degradation by the ubiquitin-proteasome pathway, thus allowing NF-KappaB to enter the nucleus to control gene expression. BCL10, a CARD domain protein implicated in MALT lymphoma, has recently been shown to play an essential role in IKK activation by TCR in T lymphocytes. However, BCLI0 does not activate IKK directly, leaving a large gap in our understanding of the signaling pathways downstream of TCR. The major goal of this proposal is to understand how BCL10 is linked to IKK on the one hand, and to TCR on the other hand. In an effort to understand how BCL10 activates IKK, we have established a cell free system that activates IKK in response to addition of BCL10 protein. Fractionation of cell extracts led to the identification of several proteins operationally defined as IKABs (IKK Activators downstream of BCL10) that mediate IKK activation by BCL10 in vitro. Significantly, we find that IKK in T cells is activated by BCL10 through a ubiquitin-dependent but proteasome-independent mechanism. These results suggest that ubiquitination plays a regulatory role not only in innate immunity, but also in adaptive immunity. Our next step is to determine whether and how IKABs are involved in IKK activation in T lymphocytes (Aim 1). We will also investigate the mechanisms by which BCL10 activates IKABs (Aim 2). Finally, we will study how BCL10 is regulated by upstream signaling molecules in the TCR pathway (Aim 3). Collectively, these lines of investigation should lead to a better understanding of the NF-KappaB signaling pathways in T cells. Such knowledge is crucial to understanding and treating various human diseases, including MALT lymphoma and other immune disorders.

描述（由申请人提供）： NF-kappab在免疫反应过程中在T淋巴细胞的激活中起关键作用。将T细胞受体（TCR）与外抗原接合后，激活了信号转导级联反应，最终导致NFKB的激活，该NFKB的激活控制了基因对T细胞增殖和功能必不可少的基因表达。尽管促炎细胞因子激活NF-KB激活的途径众所周知，但尚不清楚由TCR激活NF-kappab的机制。 NF-kappab途径的关键调节剂是Ikappab激酶（IKK）复合物，它磷酸化NF-kappab抑制剂IKAPPAB，并针对该抑制剂，以通过泛素 - 蛋白酶体途径降解，从而使NF-Kappab允许进入NF-Kappab以控制基因表达核。 BCl10是与麦芽淋巴瘤有关的卡结构蛋白，最近已显示出TCR在TCR中在TCR中起着至关重要的作用。但是，BCLI0并未直接激活IKK，在我们对TCR下游的信号通路的理解中留下了很大的差距。该提案的主要目标是了解BCL10一方面是如何与IKK链接的，另一方面是TCR。为了了解Bcl10如何激活IKK，我们建立了一个无细胞系统，该系统激活IKK以响应添加Bcl10蛋白。细胞提取物的分馏导致鉴定了几种在操作中定义为IKABS（BCl10下游的IKK激活剂）的蛋白质，可在体外介导Bcl10激活IKK激活。值得注意的是，我们发现T细胞中的IKK通过BCL10通过泛素依赖性但与蛋白酶体独立的机制激活。这些结果表明，泛素化不仅在先天免疫中，而且在适应性免疫中起着调节作用。我们的下一步是确定IKAB是否以及如何参与T淋巴细胞中IKK激活（AIM 1）。我们还将研究Bcl10激活IKAB的机制（AIM 2）。最后，我们将研究BCL10如何受TCR途径中上游信号分子的调节（AIM 3）。总的来说，这些研究线应更好地了解T细胞中NF-kappab信号通路。这种知识对于理解和治疗各种人类疾病至关重要，包括麦芽淋巴瘤和其他免疫疾病。