Small molecule in vivo probe development targeting the IL-6/STAT3 pathway for potential multiple sclerosis therapy

 描述（由申请人提供）：多发性硬化症（MS）是美国年轻人创伤后神经功能障碍的主要原因，因此大多数患者在成年后的大部分时间都受到MS的影响。目前的MS治疗是部分有效的，因此有必要开发创新策略。白细胞介素-6（IL-6）通过转录因子STAT 3进行信号传导，在MS发病机制的多个途径中发挥核心作用，并且在MS患者中已显示出IL-6/STAT 3信号传导失调。首先，IL-6通过STAT 3信号传导，诱导高度致脑炎性IL-17的产生，产生在MS的EAE模型中转移严重疾病的Th 17细胞。同时，IL-6抑制诱导型T调节细胞（iTreg）的产生，这对于抑制致病性炎症T细胞应答至关重要。因此，Teff/Treg平衡偏向于过度的T效应子应答，有利于自身免疫的发展。此外，IL-6/STAT 3信号传导有助于Teff细胞对MS患者中Treg介导的抑制的抗性，这进一步损害Teff/Treg平衡。总之，这些研究表明，IL-6/STAT 3信号通路可以作为一个创新的目标，逆转MS患者的发病机制。此外，口服可用的小分子化合物通常提供优于常用的基于肽/蛋白质的药物的改善的生物利用度和制造特征。此外，当使用口服药剂时，治疗依从性得到改善。为此，我们打算开发靶向IL- 6/STAT 3通路的小分子候选药物。我们已经开发了四种新型小分子化合物，靶向IL-6的MDL-5和MDL-16;靶向STAT 3的LLL-12和LY-5。MDL-5/16与GP 130的D1结构域结合，在IL-6/IL-6 R/GP 130信号传导复合物形成的六聚化步骤期间阻止IL-6/GP 130相互作用; LLL-12/LY-5与STAT 3的SH 2结构域结合，阻止STAT 3磷酸化和二聚化。当添加到细胞培养物中时，所有四种先导化合物均显著抑制IL-6诱导的髓磷脂特异性CD 4 T细胞中的IL-17产生。基于这些先前的研究和我们的初步数据，我们假设新型小分子IL-6/STAT 3抑制剂修复CD 4 T应答的Teff/Treg失衡，并抑制MS的EAE模型中的疾病发展和进展。以下目的将解决这一假设。目标1.优化作为候选药物的化合物。目标二。确定新型小分子IL-6/STAT 3抑制剂对修复髓鞘特异性CD 4 T应答的Teff/Treg失衡和抑制MS的EAE模型中的疾病发展的作用。确定新型小分子IL-6/STAT 3抑制剂对修复来自MS患者的CD 4 T细胞中的Teff/Treg平衡的作用。本研究是首次尝试使用新型小分子调节IL-6/STAT 3信号传导，并将阐明IL-6信号传导在MS的EAE模型中体内调节鼠和人CD 4 T应答和疾病发展的机制。本研究将为使用靶向IL-6/STAT 3信号传导的新型药理学化合物的未来临床研究奠定基础，最终目标是治疗多发性硬化症。

 DESCRIPTION (provided by applicant): Multiple Sclerosis (MS) is the leading cause of neurologic disability in the United States in young adults after trauma, thus most patients suffer from the effects of MS for most of their adult life. The current MS treatments are partially effective, making it necessary to develop innovative strategies. Interleukin-6 (IL-6), signaling through transcription factor STAT3, shares a central role in multiple pathways of MS pathogenesis and dysregulated IL-6/STAT3 signaling has been shown in MS patients. First, IL-6, signaling through STAT3, induces the generation of highly encephalitogenic IL-17, producing Th17 cells that transfers severe disease in the EAE model of MS. Meanwhile, IL-6 suppresses the generation of inducible T regulatory cells (iTreg), which is critical for dampening pathogenic inflammatory T cell responses. As a result, the Teff/Treg balance is skewed towards excessive T effector responses, favoring the development of autoimmunity. Furthermore, IL-6/STAT3 signaling contributes to the resistance of Teff cells to Treg-mediated suppression in MS patients, which further impairs Teff/Treg balance. Altogether, these studies suggest that the IL-6/STAT3 signaling pathway may serve as an innovative target for reversing pathogenesis in MS patients. In addition, orally available small molecule compounds usually offer improved bioavailability and manufacturing features over commonly used peptide/protein-based drugs. Moreover, therapy adherence is improved when oral agents are used. To this end, we intend to develop small molecule drug candidates targeting IL- 6/STAT3 pathway. We have developed four novel small molecule compounds, MDL-5 and MDL-16 targeting IL-6; LLL-12 and LY-5 targeting STAT3. MDL-5/16 bind to the D1 domain of GP130, preventing the IL-6/GP130 interaction during the hexamerization step of IL-6/IL- 6R/GP130 signaling complex formation; LLL-12/LY-5 bind to the SH2 domain of STAT3, preventing STAT3 phosphorylation and dimerization. When added into cell culture, all four lead compounds significantly inhibit IL-6 induced IL-17 production in myelin-specific CD4 T cells. Based on these previous studies and our preliminary data, we hypothesize that novel small molecule IL-6/STAT3 inhibitors repair the Teff/Treg imbalance of CD4 T responses and suppress disease development and progression in the EAE model of MS. The following aims will address this hypothesis. Aim 1. Optimize the compounds as drug candidates. Aim 2. Determine the effects of novel small molecule IL-6/STAT3 inhibitors on repairing the Teff/Treg imbalance of myelin-specific CD4 T responses and on suppressing disease development in the EAE model of MS. Aim 3. Determine the effects of novel small molecular IL-6/STAT3 inhibitors on repairing Teff/Treg balance in CD4 T cells from MS patients. This study is the first attempt to modulate IL-6/STAT3 signaling using novel small molecules and will elucidate the mechanisms through which IL-6 signaling regulates murine and human CD4 T responses and disease development in vivo in the EAE model of MS. This study will establish the basis for future clinical studies using novel pharmacological compounds that target IL-6/STAT3 signaling, with the ultimate goal of treatment of multiple sclerosis.