Preclinical study of a combined phenotype/genotype targeted treatment approach toward Ph-like acute lymphoblastic leukemia

费城染色体样急性淋巴细胞白血病（Ph样或BCR-ABL样ALL）是ALL的一种独特的高危亚型，最初通过在不存在BCR-ABL重排的情况下与Ph+ ALL相似的基因表达特征识别。已经鉴定了涉及各种细胞因子受体或酪氨酸激酶的融合基因，其可以广泛地细分为JAK-和ABL-类改变。Ph样ALL的患病率与年龄有关，从儿童期的10%到成人的近30%不等。重要的是，Ph样NCI高危ALL与需要强化化疗和/或造血干细胞移植的不良预后相关。为了推进Ph样ALL的治疗选择，提出了一种联合自然杀伤细胞免疫治疗和酪氨酸激酶抑制（TKI）方法。研究将集中在酪氨酸激酶抑制背景下NK细胞功能的生物学驱动的优化。为此，我们将产生具有CD 19定向嵌合抗原受体和NK细胞信号传导结构域的诱导多能干细胞（iPSC）衍生的NK细胞。为了防止免疫细胞耗竭并增强iPSC-NK细胞的功能性，将通过白细胞介素（IL）驱动的预激活、反式激活ARID 5 B的表达或CRISPR介导的IL信号传导检查点CISH的缺失来诱导适应性或记忆样状态。将确定适应性iPSC-CAR-NK细胞与典型iPSC-CAR-NK细胞的代谢和表观遗传状态。特别是，将评价TKI对CAR活性的影响。我们已经建立了代表ABL或JAK类激酶畸变的多种PDX Ph样ALL模型，其将用于在存在与不存在TKI的情况下体内应用iPSC-CAR-NK细胞。总之，本文提出的研究所产生的知识可以为如何在癌症治疗中整合细胞免疫疗法和突变靶向精准医学提供有价值的线索。

Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like or BCR-ABL-like ALL) is a distinct high-risk subtype of ALL that was initially identified by a gene expression signature similar to Ph+ ALL in the absence of a BCR-ABL rearrangement. Fusion genes involving various cytokine receptors or tyrosine kinases have been identified which can be broadly subdivided into JAK- and ABL- class alterations. The prevalence of Ph-like ALL is age dependent and varies from 10% at childhood to almost 30% in adults. Importantly, Ph-like NCI high-risk ALL is associated with a poor prognosis requiring intensified chemotherapy and/or hematopoietic stem cell transplantation. To advance treatment options of Ph-like ALL a combined natural killer cell immunotherapy and tyrosine kinase inhibition (TKI) approach is being proposed. Research will focus on biology-driven optimization of NK cell functionality in the context of tyrosine kinase inhibition. To this end, we will generate induced pluripotent stem cell (iPSC)-derived NK cells endowed with a CD19-directed chimeric antigen receptor and NK cell signaling domains. To prevent immune cell exhaustion and enhance functionality of iPSC-NK cells an adaptive or memory-like state will be induced by interleukin (IL) -driven pre-activation, expression of transactivating ARID5B, or CRISPR-mediated deletion of the IL-signaling checkpoint CISH. Metabolic and epigenetic state of adaptive versus canonical iPSC-CAR-NK cells will be determined. In particular, the impact of TKI on CAR activity will be evaluated. We have established a variety of PDX Ph-like ALL models representing ABL- or JAK-class kinase aberrations which will be utilized for in vivo application of iPSC-CAR-NK cells in the presence versus absence of TKI. Taken together, the knowledge generated by the research proposed herein could provide valuable clues as to how to integrate cellular immunotherapy and mutation-targeted precision medicine in cancer treatment.