Towards a new clinical trial Advanced infection proof anti HIV gene modified T ce

描述（由申请人提供）：艾滋病病毒在HAART治疗中被降低到低水平，但不能治愈。虽然药物可以预防传染性传播，但它无法清除潜伏库（LR）或持久性库（PR），这些库在HAART被移除后为感染复发提供病毒。有人说，目前还不可能对艾滋病毒进行消毒治疗，而“功能性治疗”应该吸引我们的注意力，因为这是一个更合适和可实现的目标。另一种具有功能性治愈潜力的方法利用了艾滋病毒生命周期中一个脆弱的步骤：病毒需要CD4结合才能进入细胞。gp120的突变逃避MHC呈递或抗体结合可能会阻止免疫反应而不影响传染性，而任何阻断CD4结合的病毒gp120突变都会破坏病毒的传染性。通过基因修饰表达嵌合抗原受体（CARs）的T细胞（“设计T细胞”，dTc）可以被重定向杀死病毒感染的细胞。先前制备了一种基于CD4的抗HIV CAR （CD4- tcr¿），该CAR以MHC非限制性方式重定向CTL杀死HIV gp120+细胞。然而，过继性移植自体CD4设计T细胞的临床试验未能控制病毒感染，尽管在输注一年后受体中仍有部分设计T细胞。失败的机制包括：激活诱导细胞死亡（AICD），信号和细胞因子的缺陷，调节性T细胞抑制，以及设计T细胞对HIV感染的易感性增加。这些假设中的许多都在本提案的初步数据中得到了解决，这些数据是在先前的NIH R21资助下获得的。作为回应，我们创造了一种增强T细胞激活效力的CAR，通过双信号格式提供共刺激信号（例如CD28；信号2）来创造第二代（gen）设计T细胞。我们的初步研究表明，对感染目标的高细胞毒性和该结构在关键方面的优势，证明了对该模式进行新的临床试验的合理性，包括潜在的暴露和靶向潜伏感染细胞。本研究的目的包括：1。第二代药物在临床应用前的完整表征2。利用siRNA抗CCR5和病毒Tat/Rev“抗感染”的dTc，创建第三代dTc；3. 在人源化小鼠模型中进行体内相关研究，以证明新dTc对感染的抵抗力和对HIV抑制的有效性提高；和4。如有需要，继续研究和开发更先进的第四代药物，以供后期临床开发。这些新产品的预期结果将证明dTc治疗艾滋病毒/艾滋病的新临床试验是合理的。dTc首次使用的目的是在HAART期间进行管理，以建立消除持久性病毒库和减少残留病毒血症的原理证明。这个车厢总是gp120+。如果HAART随后被撤销，观察到持续的抑制将等同于“功能性治愈”，从潜伏库中清除细胞，因为它们重新激活。我们在体外模型中表明，dtc分泌的细胞因子也可以诱导潜伏细胞重新表达病毒蛋白，使它们容易被消灭，从而提高了“灭菌治疗”的前景。无论治愈是功能性的还是绝育性的，这都将是自HAART疗法以来艾滋病治疗领域最重大的进步。

DESCRIPTION (provided by applicant): HIV is driven to low levels on HAART therapy but is not cured. While infectious spread is prevented by drugs, it does nothing to purge the latent reservoir (LR) or persistent reservoir (PR) that provide viruses for relapse of infection when HAART is removed. It has been said that there is no present likelihood for a sterilizing cure for HIV, and that a "functional cure" should attract our focus as a more suitable and attainable goal. An alternative approach with potential for functional cure exploits a vulnerable step in the life cycle of HIV: the virus requires CD4 binding to enter the cell. Whereas mutations of gp120 that escape MHC presentation or antibody binding may thwart the immune reaction without affecting infectivity, any mutation of viral gp120 that blocks CD4 binding will destroy virus infectivity. T cells expressing chimeric antigen receptors (CARs) through gene modification ("designer T cells", dTc) can be redirected to kill virus-infected cells. A CD4 based anti-HIV CAR (CD4-TCR¿) was previously prepared that redirects CTL to kill HIV gp120+ cells in an MHC non-restricted fashion. However, clinical trials of adoptive transfer of autologous CD4¿ designer T cells failed to control viral infection, despite a persistent fraction of designer T cells in recipents one year after infusion. The mechanisms of failure were proposed to include: activation induced cell death (AICD), deficiencies of signals and cytokines, regulatory T cell suppression, and heightened susceptibility of designer T cells to HIV infection. Many of these suppositions were addressed in the preliminary data for this proposal that were obtained under prior NIH R21 funding. In response, we created a CAR enhanced for potency in T cell activation via a 2-signal format that provides co-stimulatory signal (e.g., CD28; Signal 2) to create 2nd generation (gen) designer T cells. Our preliminary studies indicate high cytotoxic potency against infected targets and superiority of this construct in key aspects to justify a renewed clinical test of this modalit, including potentially the exposure and targeting of latently infected cells. Aims for this study include 1. Complete characterization of a 2nd gen agent in anticipation of a clinical application, 2. "Infection-proof" the dTc with siRNA against CCR5 and viral Tat/Rev to create a 3rd gen dTc; 3. Conduct in vivo correlate studies in a humanized mouse model to demonstrate resistance to infection of the new dTc and improved effectiveness in HIV suppression; and 4. Continuing research and development for still more advanced, 4th generation, agents for later clinical development, if needed. Anticipated results from these new products would justify new clinical trials for dTc in HIV/AIDS. The intention of the dTc first use will be to administer during HAART to establish a proof-of-principle in terms of eliminating the Persistent Reservoir and reducing residual viremia. This compartment is always gp120+. If HAART is then withdrawn, observation of a continued suppression would be tantamount to a "functional cure", eliminating cells from the Latent Reservoir as they reactivate. We have shown with an in vitro model that dTc-secreted cytokine can also induce latent cells to re-express viral proteins, rendering them vulnerable to elimination, raising the prospect of a "sterilizing cure". Whether a cure is functional or sterilizng, it would be the most significant advance in HIV treatment since HAART.