Gunalp Sinem, Helvaci Derya Goksu, Oner Aysenur, Bursalı Ahmet, Conforte Alessandra, Güner Hüseyin, Karakülah Gökhan, Szegezdi Eva, Sag Duygu
Izmir Biomedicine and Genome Center, Izmir, Türkiye.
Department of Genomic Sciences and Molecular Biotechnology, Izmir International Biomedicine and Genome Institute, Dokuz Eylul University, Izmir, Türkiye.
Front Immunol. 2023 Sep 21;14:1209249. doi: 10.3389/fimmu.2023.1209249. eCollection 2023.
TNF-related apoptosis-inducing ligand (TRAIL) is a member of the TNF superfamily that can either induce cell death or activate survival pathways after binding to death receptors (DRs) DR4 or DR5. TRAIL is investigated as a therapeutic agent in clinical trials due to its selective toxicity to transformed cells. Macrophages can be polarized into pro-inflammatory/tumor-fighting M1 macrophages or anti-inflammatory/tumor-supportive M2 macrophages and an imbalance between M1 and M2 macrophages can promote diseases. Therefore, identifying modulators that regulate macrophage polarization is important to design effective macrophage-targeted immunotherapies. The impact of TRAIL on macrophage polarization is not known.
Primary human monocyte-derived macrophages were pre-treated with either TRAIL or with DR4 or DR5-specific ligands and then polarized into M1, M2a, or M2c phenotypes . The expression of M1 and M2 markers in macrophage subtypes was analyzed by RNA sequencing, qPCR, ELISA, and flow cytometry. Furthermore, the cytotoxicity of the macrophages against U937 AML tumor targets was assessed by flow cytometry. TCGA datasets were also analyzed to correlate TRAIL with M1/M2 markers, and the overall survival of cancer patients.
TRAIL increased the expression of M1 markers at both mRNA and protein levels while decreasing the expression of M2 markers at the mRNA level in human macrophages. TRAIL also shifted M2 macrophages towards an M1 phenotype. Our data showed that both DR4 and DR5 death receptors play a role in macrophage polarization. Furthermore, TRAIL enhanced the cytotoxicity of macrophages against the AML cancer cells . Finally, TRAIL expression was positively correlated with increased expression of M1 markers in the tumors from ovarian and sarcoma cancer patients and longer overall survival in cases with high, but not low, tumor macrophage content.
TRAIL promotes the polarization of human macrophages toward a proinflammatory M1 phenotype via both DR4 and DR5. Our study defines TRAIL as a new regulator of macrophage polarization and suggests that targeting DRs can enhance the anti-tumorigenic response of macrophages in the tumor microenvironment by increasing M1 polarization.
肿瘤坏死因子相关凋亡诱导配体（TRAIL）是肿瘤坏死因子超家族的成员，在与死亡受体（DR）DR4或DR5结合后，它既可以诱导细胞死亡，也可以激活生存通路。由于TRAIL对转化细胞具有选择性毒性，因此在临床试验中被作为一种治疗药物进行研究。巨噬细胞可极化为促炎/抗肿瘤的M1巨噬细胞或抗炎/肿瘤支持性的M2巨噬细胞，M1和M2巨噬细胞之间的失衡会促进疾病发展。因此，识别调节巨噬细胞极化的调节剂对于设计有效的巨噬细胞靶向免疫疗法至关重要。TRAIL对巨噬细胞极化的影响尚不清楚。
将原代人单核细胞衍生的巨噬细胞先用TRAIL或DR4或DR5特异性配体进行预处理，然后极化为M1、M2a或M2c表型。通过RNA测序、qPCR、ELISA和流式细胞术分析巨噬细胞亚型中M1和M2标志物的表达。此外，通过流式细胞术评估巨噬细胞对U937急性髓细胞白血病肿瘤靶标的细胞毒性。还分析了TCGA数据集，以将TRAIL与M1/M2标志物以及癌症患者的总生存率相关联。
TRAIL在mRNA和蛋白质水平上均增加了人巨噬细胞中M1标志物的表达，同时在mRNA水平上降低了M2标志物的表达。TRAIL还使M2巨噬细胞向M1表型转变。我们的数据表明，DR4和DR5死亡受体均在巨噬细胞极化中起作用。此外，TRAIL增强了巨噬细胞对急性髓细胞白血病癌细胞的细胞毒性。最后，在卵巢癌和肉瘤癌患者的肿瘤中，TRAIL表达与M1标志物表达增加以及肿瘤巨噬细胞含量高（而非低）的病例中更长的总生存期呈正相关。
TRAIL通过DR4和DR5促进人巨噬细胞向促炎性M1表型极化。我们的研究将TRAIL定义为巨噬细胞极化的新调节剂，并表明靶向死亡受体可以通过增加M1极化来增强肿瘤微环境中巨噬细胞的抗肿瘤反应。
