Targeting TNFR2 Pathways in Psoriatic Diseases

项目摘要 肿瘤坏死因子是一种促炎细胞因子，通过激活两种细胞表面受体TNFR1发挥作用 和TNFR2。目前商业化批准的抗肿瘤坏死因子治疗可中和肿瘤坏死因子，从而预防肿瘤坏死因子受体1和 TNFR2激活。尽管这些抗肿瘤坏死因子药物在治疗免疫介导性疾病方面显示出很好的效果 疾病，包括牛皮癣和牛皮癣关节炎，潜在威胁生命的感染和恶性肿瘤 与长期使用有关。临床前研究表明，这些意外的影响是由于TNFR1，而不是TNFR2 失活。此外，随着时间的推移，一部分患者对抗肿瘤坏死因子治疗没有足够的反应。很遗憾，我不会 预测抗肿瘤坏死因子治疗反应的临床试验是可用的。我们的长期目标是证明 用化学抑制剂选择性灭活TNFR2通路在治疗免疫介导性疾病中有效 减少了不良反应。其次，我们的研究可能将TNFR2的一个遗传变体(TNFR2-M196R)与 对抗肿瘤坏死因子药物的反应性降低。我们的初步结果表明，TNFR2的全球敲除足以 抑制银屑病小鼠模型的炎症反应。因此，选择性地阻断TNFR2通路可能会改善银屑病 并有可能减少与TNFR1抑制相关的不良事件。之前，我们和其他人证明了PRMT5 (蛋白精氨酸甲基转移酶5)介导的精氨酸二甲基化在特定转录因子上是关键的 肿瘤坏死因子介导的炎症基因诱导。我们最近的结果表明，PRMT5的激活位于TNFR2的下游， 而不是TNFR1，PRMT5特异性化学抑制剂EPZ015666(EPZ)可以减少小鼠的银屑病炎症。 早些时候，我们还证明了非肌肉肌球蛋白(Myosin)通过与其结合，是TNFR2信号的“关闭开关”。 胞质信号域。我们现在发现，与TNFR2不同，TNFR2-M196R不能与培养的肌球蛋白结合 细胞或从人体血液中分离出来的细胞中，并在体外表现出结构性的促炎活性。根据我们的发现 初步数据推测，TNFR2的失活或PRMT5的化学抑制将会改善 牛皮癣发炎。此外，肌球蛋白与TNFR2基因变体TNFR2-M196R结合的缺陷会导致 结构性的、非肿瘤坏死因子依赖的活性，从而导致接受抗肿瘤坏死因子治疗的患者的反应性降低 探员们。我们将在两个目标上检验这一假设。在目标1中，使用两种银屑病小鼠模型，我们将研究 TNFR2活性在银屑病发病机制中的潜在机制。我们还将研究这一机制的基础 TNFR2-M196R在培养细胞中的构筑活性。此外，将回溯测试这种多态 可以预测银屑病患者对抗肿瘤坏死因子药物的反应性。在目标2中，使用体外 方法我们将研究PRMT5翻译后修饰对TNFR2功能的机制作用。 此外，利用化学和遗传方法，我们将测试PRMT5抑制在银屑病发病机制中的作用。 我们的方法，阻断TNFR2信号并保持TNFR1活性不变，是一种新颖的方法，可能会提高安全性 用于慢性免疫介导性疾病的长期治疗。此外，我们的研究可能有助于预测不充分的 早期抗肿瘤坏死因子治疗的应答者，允许更个性化的方法治疗牛皮癣疾病。

Project Summary Tumor necrosis factor-a (TNF), a proinflammatory cytokine, functions by activating two cell surface receptors, TNFR1 and TNFR2. Current commercially approved anti-TNF therapies neutralize TNF thus preventing both TNFR1 and TNFR2 activation. Although these anti-TNF agents have demonstrated great efficacy in treating immune-mediated diseases, including psoriasis and psoriatic arthritis, potentially life-threatening infections and malignancies are associated with long-term use. Preclinical studies showed these unintended effects are due to TNFR1, not TNFR2 inactivation. Further, a subset of patients do not adequately respond to anti-TNF therapy over time. Unfortunately, no clinical test to predict responsiveness to the anti-TNF therapy is available. Our long-term goal is to demonstrate that selective inactivation of TNFR2 pathways with chemical inhibitors is effective in treating immune-mediated diseases with reduced adverse effects. Secondly, our studies may link a genetic variant of TNFR2 (TNFR2-M196R) to the reduced responsiveness to anti-TNF drugs. Our preliminary results show global knockout of TNFR2 is sufficient to inhibit psoriatic inflammation in a mouse model. Thus, selectively blocking TNFR2 pathways may ameliorate psoriasis and potentially reduce TNFR1 inhibition-related adverse events. Previously we and others, demonstrated that PRMT5 (protein arginine methyltransferase 5)-mediated arginine dimethylation on specific transcription factors is critical for TNF-mediated inflammatory gene induction. Our recent results show that PRMT5 activation is downstream of TNFR2, not TNFR1, and that a PRMT5-specific chemical inhibitor, EPZ015666 (EPZ), reduces psoriatic inflammation in mice. Earlier, we also demonstrated that non-muscle myosin (myosin) is an “off-switch” of TNFR2 signaling by binding to its cytosolic signaling domain. We now discovered that unlike TNFR2, TNFR2-M196R fails to bind to myosin in cultured cells or in cells isolated from human blood and show constitutive proinflammatory activity in vitro. Based on our findings and preliminary data we hypothesize that inactivation of TNFR2 or chemical inhibition of PRMT5 will ameliorate psoriatic inflammation. Further, a defect in myosin binding to the TNFR2 genetic variant, TNFR2-M196R, causes a constitutive, TNF-independent activity, thus leading to reduced responsiveness in patients treated with anti-TNF agents. We will test this hypothesis in two aims. In Aim 1, using two psoriasis mouse models, we will investigate the mechanisms underlying TNFR2 activity on psoriatic pathogenesis. We will also study the mechanistic basis of the constitutive activities of TNFR2-M196R in cultured cells. Furthermore, will test retrospectively if this polymorphism would predict responsiveness to anti-TNF agents in patients with psoriatic diseases. In Aim 2, using in vitro approaches we will investigate the mechanistic role of PRMT5 post-translational modifications on TNFR2 function. Further, using chemical and genetic approaches we will test the effect of PRMT5 inhibition on psoriasis pathogenesis. Our approach, blocking TNFR2 signaling and leaving TNFR1 activity intact, is novel and may lead to improved safety for the long-term treatment of chronic immune-mediated diseases. Further, our study may help to predict inadequate responders to anti-TNF therapies early on, allowing more personalized approach in treating psoriatic diseases.