The effects of BTNL2 on experimental autoimmune encephalomyelitis

项目摘要 多发性硬化症(MS)是一种中枢神经系统的自身免疫性疾病，仍然是 在年轻人和老年人中都存在残疾问题。实验性自身免疫性脑脊髓炎(EAE)是最常见的 多发性硬化症常用动物模型，由致病自身抗原免疫诱导 如髓鞘少突胶质细胞糖蛋白(MOG)。一般认为多发性硬化症是由免疫介导的 对髓鞘抗原的反应，尤其是T细胞，继而是神经损伤。T细胞是 是免疫系统的主要组成部分，受刺激分子和抑制分子的调节。在这些人中 作为T细胞调节因子，B7家族成员起着核心作用。在过去的几年里，有几个新的 针对包括PD-L1/PD-1和CTLA-4在内的B7家族成员的药物已获得FDA批准 用于治疗自身免疫性疾病和癌症。丁咯菲林(BTN)和类BTN(BTN)分子 与B7家族在序列、结构和功能上相似，因此被认为是扩展的 B7家族成员。BTNL2是BTNL家族的成员。据报道，BTNL2突变是 与炎症性自身免疫性疾病有关，BTNL2蛋白在体外可以抑制T细胞功能。 BTNL2受体在活化的T细胞上表达，似乎与其他B7的受体不同 家族成员包括CD28、CTLA4、ICOS、BTLA和PD-1。我们已经证明了重组小鼠 BTNL2-IgG2Fc(mBTNL2-Ig)融合蛋白可抑制人脐静脉内皮细胞的增殖、活化和细胞因子的产生 NOD小鼠体外自身反应性T细胞。我们首先证明了mBTNL2-Ig的体内给药 减轻小鼠的1型糖尿病和移植物抗宿主病，这与其抑制能力有关 效应T细胞的增殖、活化和细胞因子的产生，但增加了调节性T细胞的生成 T细胞。我们和其他研究小组之前对BTNL2的研究使用了一种小鼠形式的蛋白质。然而，无论是 人类BTNL2(HBTNL2)是否具有类似的功能尚未确定。在这项提案中，我们将首先生产 HBTNL2-Ig蛋白，并测定其抑制小鼠和人T细胞增殖和激活的能力 在试管中。由于MS是一种T细胞介导的自身免疫性疾病，而mBTNL2-Ig可以抑制T细胞的功能，我们 假设给予mBTNL2-Ig或hBTNL-2蛋白可以改善小鼠的EAE。这 假设将在Aim1中进行检验。尽管BTNL2受体与现有的B7受体不同 对于家庭成员，受体的性质仍不清楚。在目标2中，我们计划通过新的受体识别 或者是传统的方法。这些探索性研究如果成功，有可能导致一种新的 预防和治疗多发性硬化症的方法BTNL2受体的鉴定将有助于更好地了解 BTNL2如何抑制T细胞功能，促进BTNL2在治疗白血病中的治疗进展 癌症和自身免疫性疾病。

Project Summary Multiple sclerosis (MS) is an autoimmune disease of the central nervous system and remains a major cause of disability in both young and older populations. Experimental autoimmune encephalomyelitis (EAE) is the most commonly used animal model for MS, and is induced by immunization with disease-causative self-antigens such as myelin oligodendrocyte glycoprotein (MOG). It is generally believed that MS is mediated by immune responses, especially T cells, against myelin antigens, followed by neurological impairment. T cells are the major component of the immune system, and are regulated by stimulatory and inhibitory molecules. Among the T cell regulators, the B7 family members are of central importance. In the past several years, several new drugs that target the B7 family members including PD-L1/PD-1 and CTLA-4 have been approved by the FDA for the treatment of autoimmune disease and cancer. Butyrophilin (BTN) and BTN-like (BTNL) molecules share sequence, structural, and functional similarity with the B7 family, thereby being considered as extended B7 family members. BTNL2 is a member of the BTNL family. It has been reported that BTNL2 mutations are associated with inflammatory autoimmune diseases and that BTNL2 protein can inhibit T cell functions in vitro. The BTNL2 receptor is expressed on activated T cells, and seems to be distinct from the receptors for other B7 family members including CD28, CTLA4, ICOS, BTLA and PD-1. We have shown that recombinant murine BTNL2-IgG2 Fc (mBTNL2-Ig) fusion protein can inhibit the proliferation, activation and cytokine production of autoreactive T cells from NOD mice in vitro. We were the first to show that in vivo administration of mBTNL2-Ig attenuates type 1 diabetes and graft-versus-host disease in mice, which was associated with its ability to inhibit the proliferation, activation and cytokine production of effector T cells, but increase the generation of regulatory T cells. Previous studies of BTNL2 by us and other groups used a mouse form of protein. However, whether human BTNL2 (hBTNL2) has similar functions has not been determined. In this proposal, we will first produce hBTNL2-Ig protein, and determine its ability to inhibit both mouse and human T cell proliferation and activation in vitro. Since MS is a T cell-mediated autoimmune disease and mBTNL2-Ig can inhibit T cell functions, we hypothesize that administration of either mBTNL2-Ig or hBTNL-2 protein can ameliorate EAE in mice. This hypothesis will be tested in Aim1. Although the BTNL2 receptor is distinct from the receptors for existing B7 family members, the nature of the receptor remains unknown. In Aim 2, we plan to identify the receptor by new or traditional approaches. These exploratory studies, if successful, have the potential to lead to a new approach to prevent and treat MS. The identification of the BTNL2 receptor will allow for better understanding of how BTNL2 inhibits T cell functions, and facilitate the therapeutic development of BTNL2 in the treatment of cancer and autoimmune disease.