Targeting TNFR2 Pathways in Psoriatic Diseases

项目摘要 肿瘤坏死因子-a（TNF）是一种促炎细胞因子，通过激活两种细胞表面受体TNFR 1发挥作用 TNFR2。目前商业上批准的抗TNF疗法中和TNF，从而防止TNFR 1和TNFR 2。 TNFR 2激活。尽管这些抗TNF剂在治疗免疫介导的肿瘤坏死因子相关性疾病中表现出很大的功效， 疾病，包括银屑病和银屑病关节炎，可能危及生命的感染和恶性肿瘤， 与长期使用有关。临床前研究表明，这些非预期的影响是由于TNFR 1，而不是TNFR 2 失活此外，随着时间的推移，一部分患者对抗TNF治疗没有充分应答。可惜没有 可通过临床试验预测抗TNF治疗的反应性。我们的长期目标是证明， 用化学抑制剂选择性灭活TNFR 2通路可有效治疗免疫介导的疾病 减少了副作用。其次，我们的研究可能将TNFR 2的遗传变异体（TNFR 2-M196 R）与肿瘤的发生联系起来。 对抗TNF药物的反应性降低。我们的初步结果显示TNFR 2的全面敲除足以 抑制小鼠模型中银屑病炎症。因此，选择性阻断TNFR 2通路可以改善银屑病 并潜在地减少TNFR 1抑制相关的不良事件。之前我们和其他人证明了PRMT 5 （蛋白质精氨酸甲基转移酶5）介导的特定转录因子上的精氨酸二甲基化对于 TNF介导的炎症基因诱导。我们最近的研究结果表明，PRMT 5激活是TNFR 2的下游， 而不是TNFR 1，并且PRMT 5特异性化学抑制剂EPZ 015666（EPZ）减少小鼠中的银屑病炎症。 早些时候，我们还证明了非肌肉肌球蛋白（肌球蛋白）是TNFR 2信号转导的“关闭开关”，通过结合其受体， 胞质信号结构域。我们现在发现，与TNFR 2不同，TNFR 2-M196 R在培养的细胞中不能与肌球蛋白结合。 细胞或从人血液分离的细胞中，并且在体外显示组成性促炎活性。根据我们的调查结果 根据初步数据，我们假设TNFR 2的失活或PRMT 5的化学抑制将改善 牛皮癣炎症此外，肌球蛋白与TNFR 2遗传变体TNFR 2-M196 R结合的缺陷导致肌球蛋白的过度表达。 组成型、TNF非依赖性活性，从而导致抗TNF治疗患者的反应性降低 剂.我们将从两个方面来检验这一假设。在目标1中，使用两种银屑病小鼠模型，我们将研究 TNFR 2活性对银屑病发病机制的潜在机制。我们还将研究 TNFR 2-M196 R在培养细胞中的组成型活性。此外，将回顾性测试这种多态性是否存在 可以预测银屑病患者对抗TNF药物的反应性。在目标2中，使用体外 我们将研究PRMT 5翻译后修饰对TNFR 2功能的机制作用。 此外，使用化学和遗传方法，我们将测试PRMT 5抑制对银屑病发病机制的影响。 我们的方法，阻断TNFR 2信号传导并保持TNFR 1活性不变，是新颖的，可能会提高安全性 用于长期治疗慢性免疫介导的疾病。此外，我们的研究可能有助于预测不足 因此，在早期对抗TNF治疗的应答者，允许在治疗银屑病疾病中采用更个性化的方法。

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.