肿瘤细胞治疗研究
英文原题：CD56-targeted in vivo genetic engineering of natural killer cells mediates immunotherapy for acute myeloid leukemia.
急性髓系白血病（AML）是一种异质性血液系统恶性肿瘤，起源于骨髓并扩散至其他器官。
急性髓系白血病（AML）是一种异质性血液系统恶性肿瘤，起源于骨髓并可扩散至其他器官。AML 患者在确诊时可见先天性 NK 细胞以及功能异常的 NK 细胞。NK 细胞功能障碍一方面与肿瘤细胞缺乏 NKG2D 等 NK 细胞受体相关分子、从而促进肿瘤免疫逃逸有关，另一方面也与 Polycomb 蛋白 EzH2 有关，后者在 NK 细胞的定向分化和成熟中发挥重要作用。抑制 EzH2 可增强 NK 细胞的裂解活性。然而，由于生产成本、静脉到静脉治疗周转时间长以及实验流程复杂等局限，过继性 NK 细胞转移用于癌症治疗仍受到审慎评估。为规避这些问题，本文提出一种假设：通过 CD56 靶向递送包封于壳聚糖纳米颗粒的 pSMP-EzH2 shRNA 质粒（pEzH2@CSNPs@CD56），在体内对 CD56+ NK 细胞进行基因工程改造。研究将 pSMP-EzH2 shRNA 质粒包封于壳聚糖纳米颗粒，并通过 EDC-NHS 化学反应偶联 CD56 抗体。偶联 CD56 抗体的纳米颗粒可选择性靶向 CD56+ NK 细胞，并下调人外周血单个核细胞（PBMC）中 CD56+ NK 细胞的 EzH2 表达。研究在体外富集 CD56+CD3− NK 细胞并稳定抑制 EzH2 表达，以制备供抗 AML 免疫治疗使用的过继性 CD56+CD3− NK（EzH2−）细胞。体外 NK（EzH2−）细胞和 pEzH2@CSNPs@CD56 均减轻了脾肿大；免疫表型分析还显示，在 AML1-ETO9a 诱导的裸鼠异种移植模型中，体内 c-Kit+ 白血病干细胞群体下调，而外周血和骨髓中的分化标志物 CD11b 与 Gr-1 上调。外周血和骨髓中的 CD56+CD3− 及 CD56+CD38+ 细胞群体显著增加，提示发生了 NK 细胞介导的 AML 细胞杀伤。这些结果表明，使用 pEzH2@CSNPs@CD56 是一种安全、可行的 NK 细胞介导抗 AML 免疫治疗策略。
Acute myeloid leukemia (AML) is a heterogeneous hematological malignancy that starts from bone marrow and spreads to other organs. At the time of diagnosis, both innate and defective natural killer (NK) cells are present in AML patients. The dysfunction of the NK cells is due to the absence of NK cell receptors such as NKG2D on tumor cells that help with tumor immune escape, and also the polycomb protein, EzH2, which plays an important role in the commitment and differentiation of NK cells. The inhibition of EzH2 activates NK cells towards enhanced lytic activity. However, the adoptive transfer of NK cells for cancer treatment is still under scrutiny due to limitations like production cost, vein-to-vein time, and complicated experimental procedures. In order to circumvent these issues, here, in vivo CD56 + NK cell genetic engineering is hypothesized through the CD56-directed delivery of the pSMP-EzH2 shRNA plasmid encapsulated in chitosan nanoparticles (pEzH2@CSNPs@CD56). The pSMP-EzH2 shRNA plasmid was encapsulated in chitosan nanoparticles followed by CD56 antibody conjugation through EDC-NHS chemistry. CD56 antibody-conjugated nanoparticles selectively target CD56 + NK cells and downregulate EzH2 expression in CD56 + NK cells of human PBMCs. The in vitro CD56 + CD3 - NK cells were enriched and stably suppressed EzH2 expression to prepare adoptive CD56 + CD3 - NK (EzH2 - ) cells for anti-AML immunotherapy. The in vitro NK (EzH2 - ) cells and pEzH2@CSNPs@CD56 reduced splenomegaly while immunophenotyping revealed in vivo downregulation of the c-Kit + leukemia stem cell population along with upregulation of the differentiation markers CD11b and Gr-1 in the peripheral blood and bone marrow of AML1-ETO9a-induced xenograft nude mice. CD56 + CD3 - and CD56 + CD38 + cell populations were significantly increased in the peripheral blood and bone marrow, which indicated NK cell-mediated AML cell killing took place suggesting that use of pEzH2@CSNPs@CD56 is a safe and viable strategy for NK cell-mediated anti-AML immunotherapy.
MEMBER ACCOUNT
登录成功会直接打开下一页。
