DNA Vaccination for Autoimmunity Immunoinhibitory GpG Mo

细菌DNA和免疫刺激CpG寡核苷酸(CpG-ODN)激活天然免疫系统产生促炎细胞因子。刺激性CpG基序被证明是有效的Th1样佐剂，目前被用作各种感染性疾病、肿瘤、过敏和自身免疫性疾病动物模型的有效治疗性疫苗。我们已经证明，使用编码IL-4和髓鞘蛋白的DNA联合免疫策略，可以诱导针对髓鞘的抗原特异性Th2免疫。这种方法改善并实际上逆转了正在进行的EAE。我们最近发现，应用免疫抑制的GPG-ODN，从CpG到GPG的单一碱基切换，可以有效地抑制其CpG-ODN的免疫刺激反应。此外，这种抑制性GPG-ODN不仅能够在体外抵消CpG-ODN的刺激作用，而且能够抑制实验性自身免疫性脑脊髓炎(EAE)小鼠的疾病严重程度，这是一种Th1介导的多发性硬化症动物疾病模型，并诱导Th2转变，类似于DNA与基因共接种 编码髓鞘和IL-4[Garren等人，2001]。我们将探索GPG基序在自身免疫性疾病治疗中的应用，并研究其发挥作用的潜在机制。我们将扩大GPG-ODN诱导MHC-II类分子表达减少、促进Th2转变和增强抗原特异性Th2反应的机制的临床前研究。我们将测试一种使用GPG-ODN加髓鞘编码基因的联合接种策略，以预防和逆转急性EAE，并阻止进一步复发，如果在慢性复发性EAE首次急性发作后给予。当编码髓鞘蛋白的DNA疫苗用于治疗急性发作后复发缓解性EAE时，我们将使用我们最近开发的蛋白质组髓鞘阵列来监测表位扩散和T细胞反应的性质。

Bacterial DNA and immunostimulatory CpG oligonucleotides (CpG-ODN) activate the innate immune system to produce proinflammatory cytokines. Shown to be potent Th1-like adjuvants, stimulatory CpG-motifs are currently utilized as effective therapeutic vaccines for various animal models of infectious diseases, tumors, allergies, and autoimmune diseases. We have shown that it is possible to induce antigen specific Th2 immunity to myelin, using a co-vaccination strategy with DNA encoding IL-4 and myelin proteins. This approach ameliorated and actually reversed ongoing EAE. We recently discovered that the application of an immunoinhibitory GpG-ODN, with a single base switch from CpG to GpG, can effectively inhibit the immunostimulatory response of its CpG-ODN counterpart. Moreover, this inhibitory GpG-ODN is not only capable of counteracting the stimulatory effect of CpG-ODN in vitro, it is also capable of suppressing the disease severity of experimental autoimmune encephalomyelitis (EAE) in mice, a Th1-mediated animal disease model for multiple sclerosis, and inducing a Th2 shift, much as DNA co-vaccination with genes encoding myelin and IL-4 [Garren et al, 2001]. We will explore the utility of the GpG motif for therapy of autoimmune disease, and examine the underlying mechanism whereby it exerts its effects. We will extend pre-clinical studies on the mechanism whereby GpG-ODN induces reduced expression of MHC class II, promotes a Th2 shift, and enhances antigen specific Th2 responses. We will test a co-vaccination strategy using GpG-ODN plus genes encoding myelin to prevent and reverse acute EAE, and to block further relapses, if given after the initial acute attack in chronic relapsing EAE. We will use our recently developed proteomic myelin array to monitor epitope spreading and the nature of the T cell response, when DNA vaccines encoding myelin proteins are used to treat relapsing remitting EAE after the acute attack.