Project 1: Immunotherapy of B cell lymphoma with NKT cells

项目摘要/摘要 尽管表达嵌合抗原受体(CAR)的T细胞在治疗中取得了显著进展 在复发/难治性B细胞肿瘤中，CD19特异性CAR(CAR.CD19)自体T细胞产物不是 治愈了一半以上的B-NHL患者。项目1的长期目标是开发一种安全有效的 利用CD1d限制性Va24不变量的天然和工程特性进行B-NHL的免疫治疗 自然杀伤T细胞(NKT)。与多克隆T细胞不同，NKT具有天然的抗淋巴瘤活性，通过直接 对CD1d+淋巴母细胞或/和其他免疫效应器的细胞毒作用；此外，同种异体NKT 不会产生移植物抗宿主病(GvHD)，可以制成“现成”产品。在.期间 目前项目期间，我们已经启动了allo-CAR.CD19 NKT的首个人类I期临床试验 (NCT03774654)，并治疗了前四名患者。该疗法耐受性良好，疗效客观。 3例患者有反应。然而，患者外周血中CAR.CD19 NKT的短暂持续可能 降低响应的持久性。为了保护治疗性NKT免受宿主介导的排斥反应，我们有 开发了共表达人工微(Mi)rna(Amir)的新CAR结构，由无启动子组成 针对B2M和II类主要组织相容性的嵌入shRNA序列的miRNA框架 复合反式激活剂(CIITA)。这些CAR/AMIR结构产生了人类白细胞抗原I类的降级调节 和CAR-NKT中的II类，使其对同种异体T细胞和NK细胞具有抵抗力。我们还发现了CAR-NKT 可以通过药物或转基因调节LEF1转录活性来增强治疗效力， 它控制着NKT细胞的功能适合性。我们假设allo-CAR.CD19 NKT将继续良好 对B-NHL耐受性强且有效；可通过AMIR介导进一步提高其治疗效力 保护免受免疫排斥和通过LEF1介导的抗肿瘤活性的保留。以下三项 特定的目标将检验我们的假设：1)确定异体移植的安全性、有效性和免疫活性。 CD19在B-NHL患者中的表达；2)产生cGMP allo-NKT共表达CAR.CD19与B2M和 检测allo-CAR.CD19/Amir NKTS的安全性、有效性和免疫活性。 3)评估LEF1调控NKT细胞功能适合性的机制，并检测 共表达CAR.CD19和LEF1的NKT在临床前B细胞淋巴瘤模型中的治疗效果。这个 正在进行的和拟议的研究首次严格评估了NKTS作为一种新的蜂窝平台的效用 接受重新定向的“非自体”免疫疗法。如果被证明是安全有效的，这种方法将提供一种 为治疗B-NHL以及其他类型癌症的经济高效的细胞治疗平台奠定了基础。

PROJECT SUMMARY / ABSTRACT Despite remarkable progress achieved with chimeric antigen receptor (CAR)-expressing T cells in the treatment of relapsed/refractory B lineage neoplasms, CD19-specific CAR (CAR.CD19) autologous T cell products are not curative for more than half of B-NHL patients. The long-term goal of Project 1 is to develop a safe and effective immunotherapy for B-NHL using both the natural and engineered properties of CD1d-restricted Va24-invariant natural killer T cells (NKTs). Unlike polyclonal T cells, NKTs have natural antilymphoma activity via direct cytotoxicity against CD1d+ lymphoblasts or/and by activation of other immune effectors; further, allogeneic NKTs do not produce graft-versus-host disease (GvHD) and can be prepared as “off-the-shelf” products. During the current project period, we have initiated a first-in-human phase I clinical trial of allo-CAR.CD19 NKTs (NCT03774654) and have treated the first four patients. The therapy was well tolerated and produced objective responses in three patients. However short persistence of CAR.CD19 NKTs in patient peripheral blood may decrease durability of response. To protect the therapeutic NKTs from host-mediated rejection, we have developed new CAR constructs that co-express artificial micro(mi)RNA (amiR), consisting of promoterless miRNA frames with embedded shRNA sequences targeting B2M and the class II major histocompatibility complex transactivator (CIITA). These CAR/amiR constructs produce a graded downregulation of HLA class-I and class-II in CAR-NKTs making them resistant to allogenic T and NK cells. We have also found that CAR-NKT therapeutic potency can be augmented by pharmacologic or transgenic regulation of LEF1 transcriptional activity, which controls NKT cell functional fitness. We hypothesize that allo-CAR.CD19 NKTs will continue to be well tolerated and effective against B-NHL; their therapeutic potency can be further increased via amiR-mediated protection from immune rejection and via LEF1-mediated retention of their antitumor activity. The following three specific aims will test our hypotheses: 1) to determine the safety, efficacy, and immunological activity of allo- CAR.CD19 NKTs in B-NHL patients; 2) to produce cGMP allo-NKTs co-expressing CAR.CD19 with B2M and CIITA amiRs and to determine the safety, efficacy, and immunological activity of allo-CAR.CD19/amiR NKTs in B-NHL patients; 3) to evaluate the mechanism by which LEF1 controls NKT cell functional fitness and test the therapeutic potency of NKTs co-expressing CAR.CD19 and LEF1 in pre-clinical B cell lymphoma models. The ongoing and proposed studies are the first to rigorously evaluate the utility of NKTs as a novel cellular platform for redirected “off-the-self” immunotherapy. If proven to be safe and effective, this approach will provide a foundation for a cost-effective cell therapy platform for B-NHL and perhaps other types of cancer as well.