Cellular Immunotherapy of Ovarian Cancer

项目摘要 大多数患有复发和晚期卵巢癌（OC）的女性， 选项.检查点封锁在不到15%的患者中显示出客观反应。因此 开发更有效的免疫治疗方法，如嵌合抗原受体（CAR）T细胞 （CAR-Ts）在这些患者中至关重要。我们已经将B7-H3确定为OC中CAR-T的有效靶标。我们有 CAR-Ts，并在实体瘤模型（包括OC模型）中成功测试。此外，本发明还提供了一种方法， 由于我们开发的B7-H3.CAR与mB 7-H3有交叉反应，我们进行了有效性和安全性研究 在免疫活性小鼠中显示抗肿瘤活性而无毒性。在确定并验证B7-H3为 OC的靶点，在本申请中，我们旨在克服肿瘤微环境（TME） 在OC中的免疫抑制，以充分利用CAR技术的潜力。OC中的TME的特点是 通过促进血管生成和形成免疫抑制细胞的细胞网络。特别是肿瘤 相关巨噬细胞（TAM）和髓源性抑制细胞（MDSC）在TME中丰富， OC，并抑制效应T细胞。与T细胞相比，NKT具有与T细胞共定位的先天性质。 TAM，并通过其不变TCR（iTCR）以CD 1d依赖性方式利用对TAM的裂解作用。我们 已经发表并产生了额外的初步数据，表明表达CAR的人NKT是双重的， 通过CAR特异性靶向肿瘤细胞和通过天然iTCR特异性靶向TAM。此外，我们还生成了 初步数据显示，人NKT也可以被工程化以释放IL-12，IL-12是一种已知的细胞因子， 重新编程MDSC。我们假设经工程化以表达B7-H3.CAR和IL-12的NKT将克服 实体瘤过继免疫治疗的关键挑战：效应细胞定位于肿瘤部位， 通过B7-H3.CAR选择性杀伤肿瘤细胞，通过CD 1d结合消除肿瘤保护性TAM， iTCR和通过IL-12重编程MDSC。我们新的初步数据还显示，IL-12有效地 可能通过一种新的机制增强NKT中CD 62 L相关的干细胞样程序， “维生素D签名”。因此，我们假设人类NKT可能具有以前没有的内在可塑性， IL-12可以通过维生素D途径将NKT重编程为更不成熟的表型。三 提出了具体目标： 目的1：评估NKT和天然iTCR的B7-H3.CAR和IL-12工程化是否在靶向中协同作用 OC细胞和在免疫活性鼠模型中形成TME。 目的2：从机制上评估NKT表达的IL-12如何促进NKT，使其持续时间更长， 过继性转移 目的3：评价工程化人NKT对人免疫肿瘤（HIT）小鼠的抗肿瘤活性。

Project Abstract The majority of women with relapsed and advanced ovarian cancer (OC) have then very limited therapeutic options. Checkpoint blockade has shown objective responses in less than 15% in patients. Therefore, the development of more potent immunotherapy approaches such as chimeric antigen receptor (CAR) T cells (CAR-Ts) is critical in these patients. We have identified B7-H3 as a valid target for CAR-Ts in OC. We have generated B7-H3.CAR-Ts and successfully tested them in solid tumor models including OC models. In addition, since the B7-H3.CAR we have developed cross-reacts with mB7-H3, we conducted efficacy and safety studies in immunocompetent mice showing antitumor activity without toxicity. Having identified and validated B7-H3 as a target for OC, in this application we aim at overcoming the tumor microenvironment (TME) immunosuppression in OC to fully exploit the potential of the CAR technology. The TME in OC is characterized by a cellular network that promotes angiogenesis and shapes immunosuppressive cells. In particular, tumor associated macrophages (TAMs) and myeloid-derived suppressive cells (MDSCs) are abundant in the TME of OC, and inhibit effector T cells. As compared to T cells, NKTs possess the innate property to co-localize with TAMs and to exploit lytic effects on TAMs in a CD1d-dependent manner via their invariant TCR (iTCR). We have published and generated additional preliminary data showing that CAR-expressing human NKTs are dual specific targeting both tumor cells via CAR and TAMs via native iTCR. Furthermore, we have generated preliminary data showing that human NKTs can also be engineered to release IL-12, a cytokine known to reprogram MDSCs. We hypothesize that NKTs engineered to express the B7-H3.CAR and IL-12 will overcome critical challenges of adoptive immunotherapy of solid tumors: effector cell localization to the tumor site, selective killing of tumor cells via B7-H3.CAR, elimination of tumor-protective TAMs via CD1d engagement by the iTCR, and reprogramming of MDSCs via IL-12. Our new preliminary data also revealed that IL-12 potently enhances CD62L-associated stem-like program in NKTs likely via a novel mechanism, associated with unique “vitamin D signature”. We thus hypothesize that human NKTs may have an intrinsic plasticity not previously appreciated, and that IL-12 may reprogram NKTs to a more immature phenotype via vitamin D pathway. Three specific Aims are proposed: Aim 1: To evaluate whether B7-H3.CAR and IL-12 engineering of NKTs and native iTCR cooperate in targeting OC cells and shaping the TME in an immunocompetent murine model. Aim 2: To mechanistically assess how IL-12 expressed by NKTs promotes NKTs with longer persistence upon adoptive transfer. Aim 3: To evaluate the antitumor activity of engineered human NKTs in Human-Immune Tumor (HIT) mice.