Department of Immunology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran AND Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran.
Department of Immunology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.
Iran J Allergy Asthma Immunol. 2022 Apr 11;21(2):178-188. doi: 10.18502/ijaai.v21i2.9225.
Up-regulation of immune checkpoint ligands is considered as one of the most important immune escape mechanisms in acute myeloid leukemia (AML). Herein, we investigate a relationship between the inhibition of PI3K/Akt/mTOR signaling pathways and the regulation of immune checkpoint ligands in AML cells. The HL-60 cell line was treated with idelalisib as PI3K inhibitor, MK-2206 as Akt inhibitor, and everolimus as mTOR inhibitor either in a single or combined format. Cell viability and apoptosis were evaluated using MTT and flow cytometry assays, respectively. The relative expression of PD-L1, galectin-9, and CD155 was determined by real-time PCR. Our findings demonstrated decreased proliferation and increased apoptosis of HL-60 cells after treatment with idelalisib, MK-2206, and everolimus. As expected, the combined treatment showed a more inhibiting effect than the single treatment. Interestingly, our results elucidated that the expression of PD-L1 and Gal-9 but not MK-2206 decreased after treatment with idelalisib and everolimus. Regarding CD155, the expression of this molecule was downregulated after treatment with everolimus, but not idelalisib and MK-2206. However, combined treatment of HL-60 cells with two or three inhibitors decreased the expression levels of PD-L1, Gal-9, and CD155 checkpoint ligands. We showed that PI3K/Akt/mTOR pathway inhibitors not only serve as cytotoxic drugs but also regulate the expression of immune checkpoint ligands and interfere with the immune evasion mechanisms of AML leukemic cells. Combinational treatment approaches to block these pathways might be a promising and novel therapeutic strategy for AML patients via interfering in immune escape mechanisms.
免疫检查点配体的上调被认为是急性髓细胞白血病 (AML) 中最重要的免疫逃逸机制之一。在此，我们研究了 PI3K/Akt/mTOR 信号通路的抑制与 AML 细胞中免疫检查点配体的调节之间的关系。HL-60 细胞系用 IDelalisib（PI3K 抑制剂）、MK-2206（Akt 抑制剂）和依维莫司（mTOR 抑制剂）单独或联合处理。分别用 MTT 和流式细胞术检测细胞活力和凋亡。用实时 PCR 测定 PD-L1、半乳糖凝集素-9 和 CD155 的相对表达。我们的研究结果表明，IDelalisib、MK-2206 和依维莫司处理后 HL-60 细胞的增殖减少，凋亡增加。正如预期的那样，联合治疗比单一治疗具有更强的抑制作用。有趣的是，我们的结果表明，IDelalisib 和依维莫司处理后 PD-L1 和 Gal-9 的表达降低，但 MK-2206 没有。至于 CD155，这种分子的表达在依维莫司处理后下调，但 IDelalisib 和 MK-2206 没有。然而，HL-60 细胞用两种或三种抑制剂联合处理可降低 PD-L1、Gal-9 和 CD155 检查点配体的表达水平。我们表明，PI3K/Akt/mTOR 通路抑制剂不仅作为细胞毒性药物，而且调节免疫检查点配体的表达并干扰 AML 白血病细胞的免疫逃逸机制。通过干扰免疫逃逸机制，阻断这些通路的联合治疗方法可能成为 AML 患者的一种有前途的新治疗策略。
