Gvl mHA Specific T Cell Responses Prevent AML Relapse Following Allogeneic Stem Cell Transplantation

项目摘要 异基因干细胞移植(SCT)是治疗高危急性髓系白血病的根治方法 (AML)；然而，复发仍然是SCT后死亡的主要原因。急性髓系白血病治疗后SCT取决于 条件化治疗的强度和供者免疫细胞识别和破坏的能力 通过移植物抗白血病效应(GVL)寄主白血病细胞。急性髓系白血病的突变负担很低，因此 预测的肿瘤特异性新抗原数量很少。因此，GVL很可能是由供体T介导的 白血病(和/或造血)细胞上的次要组织相容性抗原(MHA)的细胞识别 这一一般概念还没有经过详细的测试，这是因为 预测、识别并验证对任何特定SCT受者的GVL效应负责的MHA。 为了更全面地阐述GVL MHA反应在控制AML中的作用，我们将研究GVL 在原发人类样本中的反应，以检验我们的中心假设，即急性髓细胞白血病在SCT结果后复发 供者T细胞对GVL MHA反应不足。为了验证这一假设，我们将利用人体组织 人类白细胞抗原相合亲缘供者(MRD)SCTS中衡量全球数量和多样性的采集方案 供者来源的GVL MHA特异性T细胞反应在SCT中的表达。为了实现这一目标，我们将确定 通过计算机预测和生化确认的体外免疫原性(通过靶向质量 使用ELISpot、单个T细胞微阵列细胞毒性和单个T细胞的组合的GVL MHA 细胞微阵列增殖测量。我们将定位GVL MHA特异性T细胞的TCRβ序列 干细胞移植后的同种异体反应性T细胞的TCRβ谱系。我们还将研究内在抵抗力 SCT后复发的AML细胞对GVL MHA特异性T细胞的细胞毒作用 我们将把对GVL MHA特异性T细胞毒性的耐药性与 单细胞RNA测序法测定转录组图谱。 这项建议的研究将提供对GVL MHA在控制AML后的作用的理解。 SCT。由于SCT是目前治疗AML最有效的免疫治疗形式，我们对 实现有效的反洗钱控制所需的MHA目标的规模和多样性可能导致合理的 旨在提高GVL MHA的SCT实践和免疫治疗策略的改进 在不增加移植物抗宿主疾病风险的情况下进行靶向。

PROJECT ABSTRACT Allogeneic stem cell transplantation (SCT) is a curative therapy for high-risk acute myeloid leukemia (AML); however, relapse remains the leading cause of death post-SCT. AML cures post-SCT depend upon both the intensity of the conditioning therapy and the ability of donor immune cells to recognize and destroy host leukemia cells via the graft versus leukemia effect (GvL). AML has a low mutational burden and therefore a low number of predicted tumor specific neoantigens. Consequently, GvL is most likely mediated by donor T cell recognition of minor histocompatibility antigens (mHA) presented on leukemia (and/or hematopoietic) cells by MHC class I and II. This general concept has not been tested in detail however, because of limitations in predicting, identifying and then validating the mHA responsible for the GVL effect in any given SCT recipient. To more fully address the role of GvL mHA responses in controlling AML, we will investigate GvL responses in primary human samples to test our central hypothesis that AML relapse after SCT results from insufficient donor T cell responses to GvL mHA. To test this hypothesis, we will leverage a human tissue collection protocol in HLA-matched related donor (MRD) SCTs to measure the global magnitude and diversity of donor derived GvL mHA specific T cell responses in SCT. To accomplish this goal, we will determine the in vitro immunogenicity of computationally predicted and biochemically confirmed (by targeted mass spectrometry) GvL mHA using a combination of ELISpot, single T cell microraft array cytotoxicity, and single T cell microraft array proliferation measurements. We will map the TCRβ sequences of the GvL mHA specific T cells onto the TCRβ repertoires of alloreactive T cells post-SCT. We will also investigate the intrinsic resistance to GvL mHA specific T cell mediated cytotoxicity in AML blasts that relapse following SCT using our microraft arrays, and we will associate resistance to GvL mHA specific T cell cytotoxicity with differences in transcriptome profiles measured by single cell RNA sequencing. The research in this proposal will provide understanding of the role of GvL mHA in control of AML post- SCT. Because SCT is the most effective form of immunotherapy for AML at this time, our investigations into the magnitude and diversity of mHA targets required to achieve effective AML control could lead to rational improvements in the practice of SCT and immunotherapeutic strategies aimed at enhancing GvL mHA targeting without increasing graft versus host disease risk.