Focused ultrasound control of intratumoral NKG2DL BTE production by CART cells to potentiate epitope spread

项目摘要 嵌合抗原受体(CAR)T细胞疗法正在改变血液系统恶性肿瘤的临床治疗； 然而，他们在治疗实体瘤方面的临床成功有限。许多努力正在进行中，以 扩大CAR T细胞在不同癌症类型中的使用，但它们在治疗实体瘤方面的有效性 受到实体肿瘤异质性的事实的限制；通常使用CAR T细胞靶向单一抗原 结果肿瘤抗原逃逸，导致本病复发。尽管系统地交付了 免疫调节剂可以增强抗肿瘤反应，它也可以导致衰弱的不良事件 靶向，非肿瘤毒性，细胞因子释放综合征，在某些情况下，危及生命的自身免疫。通过 相比之下，免疫调节剂的瘤内给药已被证明可减少全身暴露，而 提高系统疗法的疗效。对肿瘤抗原的免疫，其结果是表位扩散后 肿瘤细胞杀伤，导致表位特异性从最初的表位多样化--启动内源性 针对更大的靶子池的免疫系统。这项提议寻求使用热敏性CAR T细胞，这是 交通和深入肿瘤，以产生双特异性T细胞活跃物(BTE)和诱导 通过DC启动内源性抗肿瘤T细胞的表位传播发展强大的免疫力。聚焦超声 (FUS)将被用来在异种肿瘤内空间储存热量，并激活由CAR设计的T细胞 利用热基因开关(TS)，它允许热触发控制小鼠T细胞中的转基因表达。 TS构建体在体温(37℃)下转录沉默，但在短时间内暴露于 加热(10分钟在40-42℃)，转基因表达水平高于基础水平的200倍以上。这些研究 将重点放在针对自然杀伤分子2，成员D配体(NKG2DL)的BTE，它是应激诱导的 抗原在肿瘤细胞和免疫抑制细胞上高度表达。临床前评估将是 在完全免疫能力的小鼠的乳腺癌小鼠模型中进行。这一方法预计将 显著增强局部CAR T细胞抗异种肿瘤的活性，同时增强内源性 抗肿瘤免疫。为了评估这一点，通过DC介导的内源性T细胞启动而传播的表位将是 调查过了。这项研究的目标的成功完成预计将阐明地方政府 CAR T细胞分泌BTE可激发内源性T细胞免疫。

Project Summary Chimeric antigen receptor (CAR) T cell therapies are transforming clinical care of hematological malignancies; however, they have shown limited clinical success in treating solid tumors. Numerous efforts are underway to expand the use of CAR T cells for different cancer types, but their effectiveness in treating solid tumors have been limited by the fact that solid tumors are heterogenous; targeting a single antigen using CAR T cells typically results in tumor antigen escape, leading to relapse of the disease. Although systemic delivery of immunomodulators can potentiate anti-tumor responses, it can also lead to debilitating adverse events from on- target, off-tumor toxicity, cytokine release syndrome, and in some cases, life-threatening autoimmunity. By contrast, intratumoral administration of immunomodulators has been shown to reduce systemic exposure while improving efficacy of systemic therapies. Immunity against tumor antigens, resultant of epitope spreading after tumor cell killing, leads to a diversification of epitope specificity from the initial epitope – priming the endogenous immune system against larger pool of targets. This proposal seeks to use thermal sensitive CAR T cells, which traffic and infiltrate deep within tumors, to intratumorally produce bispecific T cell engagers (BTEs) and induce epitope spread by DC priming of endogenous anti-tumor T cells to develop robust immunity. Focused ultrasound (FUS) will be used to spatially deposit heat within heterogenous tumors and activate CAR T cells engineered with a thermal gene switch (TS) which allows for heat-triggered control of transgene expression in murine T cells. TS constructs are transcriptionally silent at body temperature (37°C) but after exposure to a short duration of heat (10 min. at 40–42°C), express transgenes to levels greater than 200-fold above basal levels. These studies will focus on BTEs targeting natural killer group 2, member D ligands (NKG2DL), which are stress-induced antigens highly expressed on tumor cells as well as on immunosuppressive cells. Preclinical evaluation will be performed in murine models of breast cancer in fully immunocompetent mice. This approach is expected to significantly enhance local CAR T cell activity against heterogenous tumors, while potentiating endogenous antitumor immunity. To assess this, epitope spread by DC mediated priming of the endogenous T cells will be investigated. Successful completion of the aims of this study is expected to elucidate mechanisms by which local BTE secretion by CAR T cells can prime endogenous T cell immunity.