Mechanism of IL-10 protective effect in development of childhood B cell acute lymphoblastic leukemia

项目概要 尽管在了解与 B-ALL 相关的免疫系统异常方面取得了重大进展，但 出生时免疫系统的状态是否会导致白血病的发展尚不清楚。与众不同的 该应用的特点是从细胞免疫的角度来解决这个问题。我建议 除了 B 细胞祖细胞内在突变外，非 B 谱系免疫细胞也发挥着重要作用 B-ALL 发展中的作用。 B 细胞祖细胞发生突变是对炎症刺激的直接反应； 然而，骨髓中含有其他免疫细胞群，可以改变肿瘤的发展 对炎症的反应。例如，在实体癌中，低水平的细胞因子 IL-10 会引发强烈的促肿瘤作用 CD8 T 细胞和中性粒细胞的反应。具体来说，CD8 T 细胞失去了检测和裂解肿瘤的能力 细胞，而中性粒细胞的频率升高并增加活性氧和 - 氮物种（ROS/RNS）诱导癌症相关突变。我推测抗肿瘤 IL-10 增加 CD8 T 细胞活性和抑制中性粒细胞的机制参与 IL-10 在儿童 B-ALL 中的保护作用。除了加速发展 B-ALL 外，Il10-/- TEL- AML1 Cdkn2a-/- 小鼠具有更多耗尽的 PD1 CD8 记忆 T 细胞，并且还具有更高的特征 中性粒细胞水平高于 Il10 / TEL-AML1 Ckdn2a-/- 小鼠。目标 1 中的实验将扩展这一观察结果 通过测试 Il10 缺失对 CD8 记忆 T 细胞针对白血病 B 细胞的细胞毒活性的影响 以及白血病 B 细胞抑制自身免疫原性（一种免疫逃避机制）的能力。 其他实验还将追踪 CD8 T 细胞招募到白血病的程度及其 随后的细胞毒活性需要对 IL-10 有反应。这些实验将提供生物学 演示 CD8 T 细胞如何成为 IL-10 介导的 B-ALL 保护的一个因素。目标 2 的研究将 确定 Il10-/- TEL-AML1 Cdkn2a-/- 小鼠中性粒细胞产生的 ROS/RNS 是否诱导更多 DNA 与 Il10 / TEL-AML1 Ckdn2a-/- 相比，B 祖细胞受损并导致 B-ALL 潜伏期缩短 老鼠。将评估从 Il10-/- 和 Il10/ 分离的中性粒细胞的激活和 ROS/RNS 产生 白血病。然后我将确定 Il10 缺失如何影响白血病的突变情况。期望 突变总数和 ROS/RNS 相关突变特征将在 在没有 Il10 的情况下发育的白血病 B 细胞。最后，我将确定中性粒细胞是否升高 白血病前期和白血病 Il10-/- TEL-AML1 Cdkn2a-/- 小鼠的特征是 加速 B-ALL 的发展。拟议研究的结果将提供新的生物学见解 研究出生时的免疫缺陷如何导致儿童 B-ALL 的发展。此外，这部作品还 确定可用于预防高危儿童白血病的免疫反应的潜力 对于B-ALL。

Project Summary Despite significant advances in understanding immune system abnormalities associated with B-ALL, how the status of the immune system at birth contributes to leukemia development is unknown. The distinguishing feature of this application is the cellular immunity perspective from which this question is addressed. I propose that in addition to B-cell progenitor intrinsic mutagenesis, non-B lineage immune cells also play a prominent role in B-ALL development. B-cell progenitors develop mutations as a direct response to inflammatory stimuli; however, the bone marrow contains other immune cell populations that can alter tumor development in response to inflammation. For example, in solid cancers, low levels of the cytokine IL-10 elicit strong pro-tumor responses of CD8 T cells and neutrophils. Specifically, CD8 T cells lose their ability to detect and lyse tumor cells, whereas neutrophils become elevated in frequency and increase the potential for reactive-oxygen and - nitrogen species (ROS/RNS) to induce cancer-associated mutations. I hypothesize that the anti-tumor mechanisms of IL-10 in increasing CD8 T cell activity and suppressing neutrophils are involved in the protective role of IL-10 in childhood B-ALL. In addition to developing B-ALL at an accelerated rate, Il10-/- TEL- AML1 Cdkn2a-/- mice have more exhausted, PD1+ CD8 memory T cells and are also characterized by higher levels of neutrophils than Il10+/+ TEL-AML1 Ckdn2a-/- mice. Experiments in Aim 1 will extend this observation by testing the impact of Il10 loss on the cytotoxic activity of CD8 memory T cells directed to leukemic B cells and on the ability of leukemic B cells to suppress their own immunogenicity, a mechanism of immune evasion. Additional experiments will also track the extent to which the recruitment of CD8 T cells to leukemias and their subsequent cytotoxic activity requires responsiveness to IL-10. These experiments will provide a biological demonstration for how CD8 T cells can be a factor in IL-10 mediated protection in B-ALL. Studies in Aim 2 will determine if the ROS/RNS produced by neutrophils of Il10-/- TEL-AML1 Cdkn2a-/- mice induce more DNA damage in B progenitors and contribute to decreased B-ALL latency compared to Il10+/+ TEL-AML1 Ckdn2a-/- mice. Activation and ROS/RNS production will be assessed in neutrophils isolated from the Il10-/- and Il10+/+ leukemias. I will then determine how Il10 loss impacts the mutational landscape of leukemia. The expectation is that the total number of mutations and ROS/RNS-associated mutational signatures will be increased in the leukemic B cells that developed in the absence of Il10. Finally, I will determine if the elevation of neutrophils that is characterized in pre-leukemic and leukemic Il10-/- TEL-AML1 Cdkn2a-/- mice is required for the acceleration of B-ALL development. The results of the proposed research will provide new biological insights into how immune defects at birth contribute to the development of childhood B-ALL. Moreover, this work has the potential to identify immune responses that can be targeted for leukemia prevention in children at high risk for B-ALL.