Therapeutic Intervention of the JAK/STAT Pathway for Neuroinflammation

描述（由申请人提供）：多发性硬化（MS）的特征是中枢神经系统的局灶性炎性浸润、脱髓鞘病变和轴突损伤，导致神经功能障碍。先天性和适应性免疫系统的细胞参与MS发病机制。MS的特征还在于产生激活免疫细胞的细胞因子，包括IFN-？，IL-6、GM-CSF、IL-12和IL-23。JAK/STAT通路被细胞因子用于信号传导，并且对于免疫应答的发展、调节和终止至关重要。在上一个资助期，我们开发了一种实验性自身免疫性脑脊髓炎（EAE）模型，其中JAK/STAT通路在骨髓细胞中异常激活，对Th 1和Th 17细胞分化产生功能性影响。该模型表现为非典型EAE的非消退形式。在这个JAK/STAT通路活化增强的非典型模型中，我们证明了JAK/STAT通路抑制剂AZD 1480可抑制疾病严重程度，阻止免疫细胞进入CNS，抑制Th 1和Th 17细胞分化，降低STAT活化，并减少细胞因子/趋化因子的表达。此外，我们还在其他四种EAE模型（经典、复发缓解（RR）、Th 1或Th 17细胞的连续转移）中测试了AZD 1480，并观察到了显著的临床疗效。另一种JAK/STAT抑制剂AZD 5776也可抑制EAE临床症状。我们假设JAK/STAT通路的不适当激活促进先天性和适应性免疫系统细胞的异常反应，导致MS中观察到的神经炎症，并且该通路的治疗干预将改变MS的进展。在此修订的竞争性更新中，我们将在5种EAE模型中评估两种不同的JAK抑制剂AZD 1480和AZD 5776。AZD 1480是JAK 1和JAK 2抑制剂，AZD 5776抑制JAK 1。在目的1中，将检查靶向JAK/STAT通路在活动性EAE（经典、非典型、RR）中的治疗功效。我们将评估1）哪些JAK/STAT参与疾病发病机制; 2）哪些细胞类型（CD 4 + T细胞、巨噬细胞、小胶质细胞、DC）的JAK/STAT途径活化是有害的;以及3）JAK抑制剂的治疗益处的分子基础。在目的2中，将测试JAK/STAT途径在调节Th 1和Th 17细胞的致病潜力中的作用。Th 1和Th 17细胞都具有诱导CNS自身免疫的能力，但具有不同的致病机制。我们的初步结果表明，AZD 1480对Th 1诱导和Th 17诱导的EAE均有效。我们将评估在MOG免疫背景下，AZD 1480/AZD 5776体内治疗如何调节Th 1和Th 17细胞的发育程序和/或致病性。在目的3中，将检查JAK抑制剂AZD 1480和AZD 5776调节免疫细胞功能的机制。将评价从用JAK抑制剂处理的未处理小鼠获得的巨噬细胞和DC的抗原呈递能力、向促炎或抗炎表型的极化以及潜在的神经保护特性。将检查源自JAK抑制剂处理的小鼠的CD 4 + T细胞随后分化成致病性和/或保护性T细胞亚群的能力。这些研究将为最终检测人MS中JAK/STAT通路抑制剂奠定必要的临床前基础。

DESCRIPTION (provided by applicant): Multiple Sclerosis (MS) is characterized by focal inflammatory infiltrates of the CNS, demyelinating lesions and axonal damage, leading to neurologic dysfunction. Cells of the innate and adaptive immune system are involved in MS pathogenesis. MS is also characterized by production of cytokines that activate immune cells, including IFN-?, IL-6, GM-CSF, IL-12 and IL-23. The JAK/STAT pathway is used by cytokines for signaling, and is critical for the development, regulation and termination of immune responses. In the previous funding period, we developed a model of Experimental Autoimmune Encephalomyelitis (EAE) in which the JAK/STAT pathway is aberrantly activated in myeloid cells, with functional consequences for Th1 and Th17 cell differentiation. This model presents as a non-resolving form of atypical EAE. In this atypical model with heightened activation of the JAK/STAT pathway, we demonstrate that AZD1480, an inhibitor of the JAK/STAT pathway, suppresses disease severity, prevents entry of immune cells into the CNS, suppresses differentiation of Th1 and Th17 cells, decreases STAT activation, and reduces expression of cytokines/chemokines. Furthermore, we have tested AZD1480 in four other EAE models (Classical, Relapsing-Remitting (RR), Adoptive Transfer of Th1 or Th17 cells) and observed striking clinical efficacy. Another JAK/STAT inhibitor, AZD5776, also inhibits EAE clinical symptoms. We hypothesize that inappropriate activation of the JAK/STAT pathway promotes aberrant responses of cells of the innate and adaptive immune systems, leading to the neuroinflammation seen in MS, and that therapeutic intervention of this pathway will alter the progression of MS. In this revised, competing renewal, we will evaluate two distinct JAK inhibitors, AZD1480 and AZD5776, in five EAE models. AZD1480 is a JAK1 and JAK2 inhibitor, and AZD5776 inhibits JAK1. In Aim 1, the therapeutic efficacy of targeting the JAK/STAT pathway in active EAE (classical, atypical, RR) will be examined. We will evaluate 1) which JAKs/STATs are involved in disease pathogenesis; 2) in which cell type(s) (CD4+ T-cells, macrophages, microglia, DCs) activation of the JAK/STAT pathway is detrimental; and 3) the molecular basis for the therapeutic benefit of the JAK inhibitors. In Aim 2, the role of the JAK/STAT pathway in regulating the pathogenic potential of Th1 and Th17 cells will be tested. Both Th1 and Th17 cells have the capacity to induce CNS autoimmunity, but have differential pathogenic mechanisms. Our preliminary results indicate that AZD1480 is effective in inhibiting both Th1-induced and Th17-induced EAE. We will assess how in vivo treatment with AZD1480/AZD5776 in the context of MOG-immunization regulates the developmental program and/or pathogenicity of Th1 and Th17 cells. In Aim 3, the mechanism by which the JAK inhibitors AZD1480 and AZD5776 regulate immune cell function will be examined. Macrophages and DCs obtained from naive mice treated with JAK inhibitors will be evaluated for their antigen presentation capability, polarization into proinflammatory or anti-inflammatory phenotypes, and potential neuroprotective properties. CD4+ T-cells derived from JAK inhibitor treated mice will be examined for their subsequent ability to differentiate into pathogenic and/or protective T-cell subsets. These studies will establish the pre-clinical foundation necessary to ultimately test inhibitors of the JAK/STAT pathway in human MS.