Molecular and functional investigation of the role of HLA-F in immune regulation

项目总结/摘要 HLA-F是一种非经典的I类MHC（Ib）分子，已发现其在多种癌症上表达， 显示在HIV和腺病毒感染、神经系统自身免疫性疾病ALS中发挥作用， 整个怀孕期间。尽管这种蛋白质在这些条件下的潜在重要性，但人们对它知之甚少。 这个分子在它的功能方面，甚至在它表达的构象状态。我们最近 显示，除了表达为仅重链状态或开放构象（HLA-FOC）之外，HLA-F 也可以表达为与β 2 m亚基（pHLA-F）相关的真正的肽呈递分子。 肽以非常规的方式呈现，其中N-末端不锚定在沟内，并且N-末端不锚定在沟内。 潜在的翻译后修饰特征在于肽锚定。尽管有这些进步， 这些构象状态是如何被调节的，它是如何与各种受体结合的， 在这些构象状态中的每一种，以及HLA-F在其各种肿瘤监视环境中的作用， 自身免疫和生殖因此，本提案的目的是着重解决这些问题，即： 目的1：从结构和功能上研究HLA-F在HLA-F中所采用的各种构象状态， 人类健康和疾病。我们将继续进行HLA-F同种型的结构研究，以了解这些基因是如何被激活的。 两种状态彼此不同。使用符合者特异性抗体，我们将确定哪些细胞类型表达 哪种（或两者）形式以及健康细胞和疾病细胞之间的差异。我们还将进行肽洗脱 从一系列人类来源的研究，以确定肽库是否根据细胞来源发生变化 或者疾病目的2：鉴定和分析调节HLA-1产生或交换的因素。 F构象和剪接形式。我们将探讨可能在转换中发挥作用的细胞因素 HLA-F之间的肽加载和HLA-FOC，以及一个有趣的剪接变体的HLA-F的未知功能。 最后，在目标3中，我们试图建立受体库，使HLA-F在其各种构象异构体中结合， 状态，确定其关联的分子基础，并研究 他们的约束力。我们将利用亚当斯实验室的结构、生物物理和功能专业知识来确定 受体库，从事这些构象状态的HLA-F和研究他们在功能和 分子水平。

Project Summary/Abstract HLA-F is a nonclassical class I MHC (Ib) molecule that has been found expressed on a variety of cancers, shown to play a role in HIV and adenoviral infection, the neurological autoimmune disease ALS and is expressed throughout pregnancy. Despite the potential importance of this protein in these conditions, little is known about this molecule in terms of its function or even in which conformational state it is expressed. We have recently shown that, in addition to being expressed as a heavy chain only state, or open conformer (HLA-FOC), HLA-F can also be expressed as a bon fide peptide presenting molecule, associated with the β2m subunit (pHLA-F). Peptides are presented in an unconventional way, with the N-terminus not anchored within the groove and the potential for post-translational modifications featuring in peptide anchoring. Despite these advances, there remains much unknown about how these conformer states are regulated, how it engages its various receptors in each of these conformer states, and the role of HLA-F in its various environments of tumor surveillance, autoimmunity and reproduction. Thus, the aims of this proposal focus on addressing these questions and are: Aim 1: To investigate, structurally and functionally, the various conformer states that HLA-F adopts in human health and disease. We will pursue structural studies of the HLA-F isoforms to understand how these two states differ from each other. Using conformer-specific antibodies, we will determine what cell types express which (or both) forms and how this differs between healthy and disease cells. We will also pursue peptide elution studies from a range of human sources to determine if the peptide repertoire shifts depending on cellular origin or disease. Aim 2: To identify and analyze the factors that regulate the production or interchange of HLA- F conformers and splice forms in a cell. We will explore the cellular factors that may play a role in switching HLA-F between peptide-loaded and HLA-FOC as well as an intriguing splice variant of HLA-F of unknown function. Finally, in Aim 3 we seek to establish the receptor repertoire that engage HLA-F in its various conformer states, determine the molecular basis for their association and study the functional consequences of their binding. We will employ the structural, biophysical and functional expertise of the Adams lab to determine the receptor repertoire that engage these conformer states of HLA-F and study them at the functional and molecular level.