Synergy between T cells and Complement in EAE

描述(申请人提供)：我们目前对多发性硬化症(MS)免疫机制的大部分了解来自于对小鼠实验性自身免疫性脑脊髓炎(EAE)的研究。在第一种形式的模型中，用髓鞘少突胶质细胞糖蛋白(MOG)的35-55肽免疫诱导慢性进行性疾病，并伴有多种MS表现。最近，我们发现MOG 35-55免疫后，衰退加速因子(DAF)缺陷的小鼠发生的EAE比野生型(WT)对照组严重得多。DAF是一种固有的细胞表面调节因子，被认为是专门控制补体C3/C5转换酶的。临床评分明显提高，背柱淋巴细胞浸润和脱髓鞘显著增加，在细胞介导的免疫检测中，CD4+T细胞显示出8倍强的MOG 35-55回忆反应，通过增殖和干扰素-γELISPOT试验进行评估。受此结果的启发，我们在体外和体内研究了DAF对T细胞免疫反应的诱导作用，并意外地发现它通过作用于抗原提呈细胞(APC)和应答的CD4+和CD8+细胞而具有很强的抑制活性。在最近的工作中，我们发现1)MOG 35-55诱导的EAE的自身反应性延伸到蛋白脂蛋白(PLP)，以及2)DAF和CD59双重缺陷的小鼠，与DAF一起工作的相关内在补体抑制物，会比DAF缺陷的小鼠发展成更严重的疾病。一些研究表明，除了T细胞的反应性外，补体还参与了EAE的发病过程，最近的一项研究报道，CD59对完整的MOG蛋白诱导的疾病具有保护作用。DAF和CD59‘S对EAE的保护作用是通过抑制T细胞、抑制补体，还是两者兼而有之，目前尚不清楚。然而，鉴于我们新发现的DAF作为T细胞激活抑制因子和补体抑制因子的功能，以及CD59的潜在相似作用，原则上，工程重组DAF或CD59可以构成治疗MS的新的治疗方法。在拟议的研究中，我们将1)确定CD59缺乏对MOG35-55和PLP诱导的EAE中抗髓鞘T细胞自身反应和补体攻击的影响程度，2)确定DAF(如果发现的话)发挥免疫抑制活性的细胞位置(S)，以及，基于1)和2)开发适当靶向的DAF(和/或CD59)治疗剂，并测试其改善疾病的能力。

DESCRIPTION (provided by applicant): Much of our current understanding of immune mechanisms underlying multiple sclerosis (MS) comes from studies of experimental autoimmune encephalomyelitis (EAE) in mice. In 1 form of the model, immunization with the 35-55 peptide of myelin oligodendrocyte glycoprotein (MOG) induces chronic progressive disease with many manifestations of MS. Recently, we found that following MOG 35-55 immunization, mice deficient in decay accelerating factor (DAF), an intrinsic cell surface regulator previously thought to exclusively control complement C3/C5 convertases, develop dramatically more severe EAE than wild type (WT) controls. Clinical scores are markedly higher, lymphocyte infiltration and demyelination in dorsal columns are profoundly increased, and in cell-mediated immune assays, CD4+ T cells show 8-fold stronger MOG 35-55 recall responses as assessed both by proliferation and IFN-gamma ELISPOT assays. Prompted by this result, we studied DAF's effect both in vitro and in vivo on the induction of T cell immune reactivity, and unexpectedly found that it possesses potent inhibitory activity via effects both on antigen presenting cells (APCs) and responder CD4+ and CD8+ cells. In recent work we have found that 1) autoreactivity in MOG 35-55 induced EAE extends to proteolipid protein (PLP) and 2) mice doubly deficient in DAF and CD59, a related intrinsic complement inhibitor that works together with DAF, develop even more severe disease than DAF deficient mice. Some studies have shown that, in addition to T cell reactivity, complement participates in EAE pathogenesis, and a recent study has reported that CD59 protects against disease induced with whole MOG protein. Whether DAF's and CD59's protective effects in EAE are mediated via T cell inhibition, complement inhibition, or both is not established. Nevertheless, in view of our new findings of DAF's function as a T cell activation inhibitor as well as a complement inhibitor, and potentially similar effects of CD59, engineered recombinant DAF or CD59 could, in principle, constitute new therapeutic approaches for treating MS. In the proposed research we will 1) determine the extent to which deficiency of CD59 affects anti-myelin T cell autoreactivity as well as complement attack in both MOG 35-55-and PLP-induced EAE, 2) determine the cellular site(s) at which DAF (and CD59 if found) are exerting immune inhibitory activity, and, based on 1) and 2) develop appropriately targeted DAF (and/or CD59) therapeutic agents and test their abilities to ameliorate disease.