The effects of BTNL2 on experimental autoimmune encephalomyelitis

项目摘要 多发性硬化症（MS）是中枢神经系统的自身免疫性疾病，并且仍然是多发性硬化症的主要原因。 年轻人和老年人都有残疾。实验性自身免疫性脑脊髓炎（EAE）是最常见的 MS的常用动物模型，并且通过用致病性自身抗原免疫诱导 如髓鞘少突胶质细胞糖蛋白（MOG）。一般认为MS是由免疫系统介导的， 反应，特别是T细胞对髓鞘抗原，其次是神经功能障碍。T细胞是 是免疫系统的主要组成部分，并受刺激和抑制分子的调节。中 作为T细胞调节因子，B7家族成员至关重要。在过去的几年里，新 针对B7家族成员的药物，包括PD-L1/PD-1和CTLA-4，已获得FDA批准 用于治疗自身免疫性疾病和癌症。嗜丁酸蛋白（BTN）和BTN样（BTNL）分子 与B7家族共享序列、结构和功能相似性，因此被认为是扩展的 B7家庭成员BTNL 2是BTNL家族的成员。据报道，BTNL 2突变是一种基因突变。 与炎性自身免疫性疾病相关，并且BTNL 2蛋白可以在体外抑制T细胞功能。 BTNL 2受体在活化的T细胞上表达，并且似乎与其他B7受体不同。 家族成员包括CD 28、CTLA 4、ICOS、BTLA和PD-1。我们已经证明，重组鼠 BTNL 2-IgG 2 Fc（mBTNL 2-IG）融合蛋白可抑制肿瘤细胞的增殖、活化和细胞因子的产生。 来自NOD小鼠的自身反应性T细胞。我们是第一个显示体内给予mBTNL 2-IG 减轻小鼠的1型糖尿病和移植物抗宿主病，这与其抑制 抑制效应T细胞的增殖、活化和细胞因子的产生，但增加调节性T细胞的产生。 T细胞。我们和其他研究小组以前对BTNL 2的研究使用了一种小鼠形式的蛋白质。但无论 人BTNL 2（hBTNL 2）是否具有类似的功能尚未确定。在这份提案中，我们将首先制作 hBTNL 2-IG蛋白，并测定其抑制小鼠和人T细胞增殖和活化的能力 体外由于MS是一种T细胞介导的自身免疫性疾病，并且mBTNL 2-IG可以抑制T细胞功能，因此，我们 假设施用mBTNL 2-IG或hBTNL-2蛋白可以改善小鼠中EAE。这 将在Aim 1中检验假设。虽然BTNL 2受体不同于现有的B7受体， 尽管该家族成员中有许多人，但该受体的性质仍不清楚。在目标2中，我们计划通过新的 或传统方法。这些探索性研究如果成功，有可能导致新的 BTNL 2受体的鉴定将允许更好地理解MS。 BTNL 2如何抑制T细胞功能，并促进BTNL 2在治疗恶性肿瘤中的治疗开发， 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.