Regulation of the baboon HLA-G-like class Ib MHC gene, Paan-AG

描述(申请人提供)：人类白细胞抗原-G(人类白细胞抗原-G)是一种在怀孕期间在人类母胎界面高度表达的蛋白质，被认为是半异基因胎儿存活的关键。我们的长期目标是阐明人类白细胞抗原-G在妊娠中的作用，作为评估重组人类白细胞抗原-G蛋白在妊娠相关病理和移植中的治疗潜力的先决条件。目前的证据表明，人类白细胞抗原-G计划母婴交界处的免疫细胞进入免疫抑制表型。它与先兆子痫的发生、体外受精(IVF)项目的植入成功、心脏移植的存活以及一些肿瘤的存活有关。然而，人类白细胞抗原G功能的确凿证据仍然难以捉摸，因为出于伦理方面的考虑，在人体上进行实验是不可能的。在寻找合适的动物模型的过程中，我们已经确定橄榄狒狒(Papio Anubis)是一个潜在的候选者。这种灵长类动物在胎盘中表达一种名为Paan-AG的类似于HLA-G的蛋白。我们的假设是，PAAN-AG可能是人类白细胞抗原G的功能同源物。初步数据显示，PAAN-AG与人类白细胞抗原-G有许多相似之处，包括有限的多态性，mRNA的选择性剪接，以及蛋白表达的组织限制(主要在胎盘)。蛋白质在组织中的表达受到限制，这表明这两个基因可能共享组织特有的调控元件。为了确定狒狒是否是一个有用的模型，有必要确定Paan-AG的调节是否与迄今已知的HLA-G的调节相似。这项建议的目的是确定PAAN-AG的5‘和3’非翻译区或内含子中的组织特异性调控元件。我们之前使用转录因子搜索系统软件在这些区域中鉴定了一些可能的调控元件。我们将使用电泳迁移率改变分析和荧光素酶报告分析来评估这些元件在不同细胞系中的活性。结果将显示PAAN-AG的组织特异性表达是否受组织特异性调控元件控制，以及该元件的位置(S)。否定的结果将引导我们未来的研究重点放在翻译后机制作为PAAN-AG组织特异性表达的候选，并由此推断，人类白细胞抗原-G。公众健康：了解人类白细胞抗原-G的功能是至关重要的，因为重组人类白细胞抗原-G蛋白在治疗妊娠并发症或移植中具有潜在的治疗作用。在受精卵的成熟顺序、着床和胎盘形成过程以及胎盘中产生的人类白细胞抗原-G样蛋白(PAAN-AG)方面，狒狒的生殖系统与人类非常相似。因此，狒狒显然是一个很好的模型，用于进行人类白细胞抗原G功能实验，并测试人类妊娠和移植中的治疗应用。

DESCRIPTION (provided by applicant): The human leukocyte antigen-G (HLA-G), a protein highly expressed at the human maternal- fetal interface during pregnancy, is thought to be critical in survival of the semi-allogenic fetus. Our long-term goal is to elucidate the role of HLA-G in pregnancy as a prerequisite to assessing the therapeutic potential of recombinant HLA-G proteins in pregnancy-related pathologies and transplantation. Current evidence suggests HLA-G programs immune cells at the maternal-fetal interface into immunosuppressive phenotypes. It has been implicated in development of preeclampsia, implantation success in in vitro fertilization (IVF) programs, survival of heart transplants and survival of some tumors. However, definitive proof of HLA-G function remains elusive since in vivo experiments in humans are not possible due to ethical concerns. In the search for an appropriate animal model, we have identified the olive baboon (Papio anubis) as a potential candidate. This primate expresses an HLA-G-like protein termed Paan-AG in the placenta. Our hypothesis is that Paan-AG could be the functional homologue of HLA-G. Preliminary data shows that Paan-AG shares many characteristics with HLA-G, including limited polymorphism, alternative splicing of the mRNA, and restricted tissue of expression of the protein (mainly in the placenta). The restricted tissue expression of the proteins suggests the two genes might share tissue-specific regulatory elements. In order to confirm whether the baboon is a useful model, it is necessary to establish whether regulation of Paan-AG is similar to that of HLA-G as known to date. The aim of this proposal is to identify tissue-specific regulatory elements in the 5' and 3' untranslated regions or introns of Paan-AG. We previously identified a number of putative regulatory elements in these regions using a transcription factor search system software. We will assess activity of these elements using electrophoretic mobility shift assays and luciferase reporter assays in different cell lines. The results will show whether the tissue-specific expression of Paan-AG is controlled by tissue- specific regulatory element, and the location of such element(s). A negative result will guide our future research to focus on post-translational mechanisms as candidates for tissue-specific expression of Paan-AG, and by inference, HLA-G. TO PUBLIC HEATH: Understanding the function of HLA-G is critical because of the potential therapeutic use of recombinant HLA-G proteins in the management of pregnancy complications or in transplantation. The baboon's reproductive system closely resembles that of human in terms of maturation sequence of fertilized eggs, implantation and placentation process, and in production of HLA-G- like proteins (Paan-AG) in the placenta. Thus the baboon is clearly an excellent model for HLA-G functional experiments, and testing the therapeutic applications of HLA-G in human pregnancy and transplantation.