Targeting Alloreactivity for Leukemia Eradication

6.靶向同种异体反应性治疗白血病 异基因造血干细胞移植（HCT）后白血病的根除部分是 它是由T细胞介导的，并代表了基于免疫的治疗潜力的显着证明。 治疗人类恶性肿瘤。有大量证据表明，免疫介导的移植物与 白血病（GVL）效应是由对受体未成年人特异性的供体T细胞识别白血病细胞引起的 组织相容性抗原。不幸的是，T细胞对次要组织相容性抗原的应答也可以 导致GVHD，并且难以将GVL效应与GVHD分离。未成年人的发现 选择性地在白血病细胞上而不是在上皮上表达的组织相容性抗原， 为增强同种异体HCT的GVL效应提供了新的机会。然而，实施有针对性 接受未经修饰的异基因干细胞移植并需要 移植后免疫抑制药物的给药已被证明具有挑战性。我们发现， 干细胞接种物中的T细胞负责GVHD，这为操纵GVHD提供了机会。 同种异体造血细胞移植以去除该细胞亚群并潜在地减少GVHD。的 该项目的目标是发现作为选择性GVL靶点的次要组织相容性抗原 目的是评估干细胞移植物的工程化以去除导致GVHD的天然供体T细胞， 提供了一个平台，能够选择性靶向白血病细胞上的同种异体决定簇， 一个持久的GVL反应。具体目标是： 1)鉴定编码白血病细胞提呈的新型人类次要组织相容性抗原的基因 并被CD8+ T细胞识别。 2)为了确定去除一半T细胞的干细胞移植物的移植是否减少了移植物抗 HLA相合同胞造血干细胞移植急性白血病患者宿主病 3)确定用次要组织相容性抗原接种同种异体HCT供体是否安全， 激发特异性T细胞反应。 这项研究与公共卫生的相关性：异基因造血细胞移植（HCT）可以 治疗许多其他方法无法治愈的恶性肿瘤， 年移植物抗宿主病和恶性肿瘤复发是两种最常见的并发症， 导致患者在同种异体HCT后痛苦和死亡。本提案中的研究旨在 发现HCT消除肿瘤的细胞和分子机制， 以及更有效的移植方案

6. Targeting Alloreactivity for Leukemia Eradication The eradication of leukemia after allogeneic hematopoietic stem cell transplantation (HCT) is in part mediated by T cells and represents a remarkable demonstration of the curative potential of immune-based therapy for human malignancy. There is substantial evidence that the immunologically mediated graft versus leukemia (GVL) effect results from recognition of leukemic cells by donor T cells specific for recipient minor histoco.mpatibility antigens. Unfortunately, T cell responses to minor histocompatibility antigens can also cause GVHD, and it has been difficult to segregate the GVL effect from GVHD. The discovery of minor histocompatibility antigens that are selectively expressed on leukemic cells and not on epithelium is providing new opportunities to augment the GVL effect of allogeneic HCT. However, implementing targeted immunotherapy in patients who receive unmodified allogeneic stem cell transplants and require the administration of immunosuppressive drugs post transplant has proven challenging. The discovery that naTve T cells in the stem cell inoculum are responsible for GVHD has provided the opportunity for manipulation of allogeneic hematopoietic cell grafts to remove this subset of cells and potentially reduce GVHD. The objectives of this project are to discover minor histocompatibility antigens that are targets for a selective GVL effect and to evaluate engineering the stem cell graft to remove naTve donor T cells that cause GVHD to provide a platform that enables selective targeting of allogeneic determinants on leukemic cells to promote an enduring GVL response. The specific aims are: 1) To identify genes that encode novel human minor histocompatibility antigens presented by leukemic cells and recognized by CD8+T-cells. 2) To determine whether transplantation of stem cell grafts depleted of halve T cells reduces graft versus host disease in HLA identical sibling stem cell transplant recipients with acute leukemia. 3) To determine if vaccination of allogeneic HCT donors with minor histocompatibility antigens is safe and elicits a specific T-cell response. Relevance of this research to public health: Allogeneic hematopoietic cell transplantation (HCT) canbe curative for many malignancies that are otherwise incurable and is used to treat thousands of patients each year. Graft versus host disease and relapse of the malignancy are the two most frequent complications that contribute to patient suffering and death after allogeneic HCT. The studies in this proposal are aimed at discovering the cellular and molecular mechanisms by which HCT eliminates tumors and developing safer and more effective transplant regimens.