Project 5: Enhancement of the Anti-Tumor Activity and Targeted Applications of Third Party Donor-Derived EBV-specific T-cells

用抗原特异性T细胞或表达嵌合抗原的T细胞过继免疫治疗 受体(CAR)已成为治疗药物难治性病毒感染的一种潜在的治疗方法 异基因造血细胞移植(HCT)后B系恶性肿瘤的复发。我们的节目 最近提供的证据表明，EBV特异性的、适当的人类白细胞抗原限制了部分来自人类白细胞抗原的T细胞 匹配的第三方捐献者也可以在70%的allo-HCT接受者中诱导持久的完全或部分缓解 61%的实体器官移植(SOT)患者对Rituxan耐药，SOT患者接受化疗 难治性EBV+淋巴瘤。与我们的证明一致的是，同种异体反应性T细胞在 自体EBV+BLCL体外反复致敏、第三方EBVCTL过继转移的疗程 与移植肾功能受损或移植物抗宿主病无关。引人注目的是，细胞因子的释放 也没有观察到综合征。 在这个项目中，我们提出了扩大和加强银行第三方捐赠者或衍生的应用的策略。 EBV特异性CTL，目前可以提供有效的、可立即获得的、“现成”的CTL 对异体血细胞移植和SOT患者的过继治疗，对其他EBV相关恶性肿瘤的患者，包括 血液疾病，如EBV+霍奇金氏病，NK T细胞淋巴瘤，HLH和Burkitt淋巴瘤 以及EBV阴性的B细胞白血病和淋巴瘤，需要进行异基因红细胞移植。该项目 将在体外和临床前模型中测试三个假设：1)表观遗传修饰剂，如5-氮杂胞苷， 地西他滨和HDAC抑制剂、涡旋剂和罗米迪辛已被发现可诱导潜伏感染 EBV+恶性肿瘤表达EBV裂解周期基因，使其对更昔洛韦易感，可 用于低毒的重复短时间暴露以诱发潜伏期I和II的恶性肿瘤，如Burkitt 淋巴瘤、NK T细胞淋巴瘤、EBV+霍奇金病和鼻咽癌的表达潜伏期 3和早期裂解的EBV蛋白，如BZLF-1，从而使它们对EBV特异的、HLA限制性的易感 以EB病毒转化的以T细胞为主的自体BLCL致敏第三方CTL 这些EBV抗原的特异性；2)有限的第三方CD19 CAR+EBVCTL库可以立即和 CD19+B系ALL或DLBCL移植后复发患者的有效过继治疗 没有GVHD。此外，它们的抗肿瘤活性和持久性可以通过CARS进一步增强 指导IL-12的表达。3)CD19 CAR+EBVCTL和CD19 CAR+的抗肿瘤活性 分泌IL-12的EBVCTL可通过a)小剂量表观遗传学预先输注治疗而进一步增加 修饰以改变肿瘤的激活和抑制配体的表达，从而增强其敏感性 与CD19 CAR+、EBVCTL和/或b)联合应用检查点抑制物以增强 CD19 CAR+EBVCTL参与和溶解B系ALL和DLBCL。

Adoptive immunotherapy with antigen-specific T cells or T cells engineered to express a chimeric antigen receptor (CAR) has emerged as a potentially curative approach to the treatment of drug refractory viral infections and relapses of B lineage malignancies following allogeneic hematopoietic cell transplants (HCT). Our program has recently provided evidence that EBV-specific, appropriately HLA restricted T cells from HLA partially matched third party donors can also induce durable complete or partial remissions in 70% of allo-HCT recipients and 61% of solid organ transplant (SOT) recipients with Rituxan resistant and, in SOT patients, chemotherapy refractory EBV+ lymphomas. Consistent with our demonstration that alloreactive T-cells are depleted in the course of repeated in vitro sensitizations with autologous EBV+ BLCL, adoptive transfer of 3rd party EBVCTL has not been associated with either impairment of allograft function or GVHD. Strikingly, cytokine release syndrome has also not been observed. In this project, we propose strategies to extend and enhance the application of banked third party donorderived EBV-specific CTLs that currently can provide effective and immediately accessible, “off the shelf” adoptive therapies for alloHCT and SOT patients, to patients with other EBV-associated malignancies including hematologic diseases such as EBV+ Hodgkins disease, NK T cell lymphomas, HLH and Burkitt lymphomas as well as EBV negative B cell lineage leukemias and lymphomas for which an alloHCT is indicated. The project will test in vitro and in preclinical models, three hypotheses: 1) Epigenetic modifiers such as 5-azacytidine, decitabine and the HDAC inhibitors, vorinostat and romidepsin which have been found to induce latently infected EBV+ malignancies to express lytic cycle genes of EBV so as to render them susceptible to ganciclovir can be used in repeated short exposures of low toxicity to induce latency I and II malignancies, such as Burkitt lymphomas, NK T cell lymphomas, EBV+ Hodgkins disease and nasopharyngeal carcinoma, to express latency 3 and early lytic EBV proteins such as BZLF-1, thereby rendering them susceptible to EBV-specific, HLArestricted 3rd party CTLs sensitized with autologous EBV transformed BLCLs that predominantly contain T cells specific for these EBV antigens; 2) A limited bank of 3rd party CD19 CAR+ EBVCTL can provide immediate and effective adoptive therapy for most patients relapsing with CD19+ B lineage ALL or DLBCL post transplant without GVHD. Furthermore, their anti-tumor activity and persistence can be further augmented by CARS directing the expression of IL-12. 3) The anti-tumor activity of the CD19 CAR+ EBVCTLs and CD19 CAR+ EBVCTLs secreting IL-12 can be further increased by a) pre-infusion treatment with low doses of epigenetic modifiers so as to alter tumor expression of activating and inhibitory ligands, and thereby enhance their sensitivity to the CD19 CAR+, EBVCTLs, and/or b) co-administration of a checkpoint inhibitory to enhance the capacity of the CD19 CAR+ EBVCTLs to engage and lyse B lineage ALL and DLBCL.