CAR-T cell control through orthogonal antibody-based switches

项目摘要/摘要： 嵌合抗原受体T(CAR-T)细胞疗法在癌症的临床试验中取得了显著的效果； 为复发难治性急性淋巴细胞白血病患者提供完全缓解，并提供 患者对治愈抱有现实的希望.然而，与无法控制一次CAR-T细胞有关的挑战 输注给患者带来了重大的安全问题。这包括永久性B细胞再生障碍性贫血和死亡病例 细胞因子释放综合症。此外，恶性细胞上抗原表达的丧失使常规 CAR-T细胞对复发疾病无效，并被归因于在 急性淋巴细胞白血病和慢性淋巴细胞白血病的早期临床试验。相应地，控制机制的发展 CAR-T细胞代表着一种严重而紧迫的未得到满足的医疗需求，需要对其进行彻底的调查 为患者提供安全有效的CAR-T细胞治疗。 为此，本提案描述了一种设计基于抗体的开关的方法，该方法能够 可调控制CAR-T细胞活动。这些开关调节了一种正交免疫学的形成 靶细胞、Switch和CAR-T细胞之间的突触在结构上、化学计量学上和时间上是 定义为启用以前未报告的控制级别。这项工作的长期目标是 了解这些交换机如何提高临床安全性和多功能性。这样做的总体目标是 建议研究在白血病和白血病的情况下使用开关控制CAR-T细胞的活动 用小鼠模型制作淋巴瘤模型。我们的中心假设是，基于抗体的开关控制着 体内CAR-T细胞活性的特异性和持续时间将使控制有效性、持久性和安全性成为可能 过继转移的CAR-T细胞。这项研究的基本原理是，一种功能强大的SCAR-T细胞 与传统的CAR-T细胞疗法相比，它在患者的免疫系统内更安全，因为它是 由基于抗体的开关的剂量控制，并且完全依赖于剂量。 为了检验中心假设，目标1将确定可切换的CAR-T细胞重定向到超过 模拟疾病复发的小鼠模型中的一种抗原。目标2将确定基于交换机的控制如何 影响CAR-T细胞表型，这一点很重要，因为持续性表型与 临床试验中的完全缓解。目标3将使用一种独特的小鼠模型来概括毒性 与传统的CART-19疗法相关，展示对严重不良反应的基于开关的控制 效果。拟议的研究是开发通用汽车结构的重要一步，该结构 将不再需要为每个抗原靶标重建一辆新的汽车。预计这一数字将大幅下降 “从板凳到床边”发展的成本和时间，以及提供标准化的治疗方案， 用传统的CAR-T细胞是不可能的。

Project Summary/Abstract: Chimeric antigen receptor T (CAR-T) cell therapy has produced remarkable results in clinical trials for cancer; providing complete remissions in patients with relapsed refractory acute lymphoblastic leukemia, and offering patients a realistic hope for a cure. However, challenges related to the inability to control CAR-T cells once infused into the patient pose significant safety concerns. This includes permanent B cell aplasia and fatal cases of cytokine release syndrome. Additionally, loss of antigen expression on malignant cells renders conventional CAR-T cells ineffective against relapsed disease and has been attributed to a significant number of relapses in early stage clinical trials for ALL and CLL leukemia. Correspondingly, the development of mechanisms to control CAR-T cells represents a critical and urgent unmet medical need which warrants thorough investigation to provide a safe and efficacious CAR-T cell therapy for patients. Towards this end, this proposal describes a method of engineering antibody-based switches which enables tunable control over CAR-T cell activity. These switches mediate formation of an orthogonal immunological synapse between the target cell, switch, and CAR-T cell which is structurally, stoichiometrically, and temporally defined to enable a level of control which has not been reported previously. The long term goal of this work is to understand how these switches can improve safety and versatility in the clinic. The overall objective of this proposal is to investigate the use of switches to control activity of CAR-T cells in the context of leukemia and lymphoma using mouse models. Our central hypothesis is that antibody-based switches which control the specificity and duration of CAR-T cell activity in vivo will enable control over the efficacy, persistence, and safety of adoptively transferred CAR-T cells. The rationale for this research is that a sCAR-T cell which functions orthogonally within the patient’s immune system is safer than conventional CAR-T cell therapy because it is controlled by, and entirely dependent on, dosing of the antibody-based switch. To test the central hypothesis, aim 1 will determine the redirection of switchable CAR-T cells to more than one antigen in mouse models which mimic disease relapse. Aim 2 will determine how switch-based control effects CAR-T cell phenotype which is significant because persistent phenotypes are strongly associated with complete remissions in clinical trials. Aim 3 will use a unique mouse model which recapitulates the toxicity associated with conventional CART-19 therapy to demonstrate switch-based control over severe adverse side effects. The proposed research is a significant step in the development of a universal CAR construct which would obviate the need to reconstruct a new CAR for each antigen target. This is expected to substantially lower the cost and time of “bench to bedside” development, as well as provide a standardized treatment regimen which is not yet possible with conventional CAR-T cells.