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

描述（由申请人提供）：HAART治疗将HIV驱动至低水平，但未治愈。虽然药物可以预防感染性传播，但当HAART被移除时，它无法清除为感染复发提供病毒的潜伏储存库（LR）或持久储存库（PR）。有人说，目前不可能找到治愈艾滋病毒的绝育方法，“功能性治愈”应该作为一个更合适和更可实现的目标吸引我们的关注。另一种具有功能性治愈潜力的方法利用了HIV生命周期中的一个脆弱步骤：病毒需要CD 4结合才能进入细胞。然而，逃避MHC呈递或抗体结合的gp 120突变可能会阻碍免疫反应而不影响感染性，而阻断CD 4结合的病毒gp 120突变将破坏病毒感染性。通过基因修饰表达嵌合抗原受体（汽车）的T细胞（“设计者T细胞”，dTc）可以被重定向以杀死病毒感染的细胞。先前制备了基于CD 4的抗HIV CAR（CD 4-TCR），其以MHC非限制性方式重定向CTL以杀死HIV gp 120+细胞。然而，自体CD 4设计T细胞过继转移的临床试验未能控制病毒感染，尽管在输注后一年，接受者中设计T细胞的持续分数。 失败的机制被认为包括：激活诱导的细胞死亡（AICD），信号和细胞因子的缺陷，调节性T细胞抑制，以及设计者T细胞对HIV感染的易感性增加。这些假设中的许多都在先前NIH R21资助下获得的该提案的初步数据中得到了解决。作为响应，我们通过提供共刺激信号（例如，CD 28;信号2）以产生第二代（gen）设计者T细胞。我们的初步研究表明，对感染的目标和优越性，这种结构在关键方面的高细胞毒性效力，以证明这种modalit的更新的临床试验，包括潜在的暴露和潜在感染细胞的靶向。本研究的目的包括1。第二代试剂的完整表征，预期临床应用，2。用针对CCR 5和病毒达特/Rev的siRNA“防干扰”dTc以产生第三代dTc; 3.在人源化小鼠模型中进行体内相关研究，以证明新dTc对感染的抗性和HIV抑制的改善的有效性;和4.继续研究和开发更先进的第4代药物，用于后期临床开发（如需要）。这些新产品的预期结果将证明dTc在HIV/AIDS中的新临床试验是合理的。首次使用dTc的目的是在HAART期间给药，以建立消除持久性储库和减少残留病毒血症的原理证明。 这个隔间总是gp 120+。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”，在细胞重新激活时将其从潜伏库中消除。我们已经用体外模型表明，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，使它们易于消除，提高了“灭菌治疗”的前景。无论治愈是功能性的还是绝育的，这都将是自HAART以来艾滋病治疗的最重大进展。

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.