Lai Chun-Yi, Tseng Po-Chun, Chen Chia-Ling, Satria Rahmat Dani, Wang Yung-Ting, Lin Chiou-Feng
Core Laboratory of Immune Monitoring, Office of Research & Development, Taipei Medical University, Taipei, 110, Taiwan.
Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, 110, Taiwan.
J Inflamm Res. 2021 Oct 13;14:5241-5249. doi: 10.2147/JIR.S329921. eCollection 2021.
Phorbol 12-myristate 13-acetate (PMA)-induced differentiation of human monocytic THP-1 cells is an experimental model for preparing resting macrophages (M) for cell polarization toward the different functional specializations of macrophages.
In this study, we examined the expression of immune checkpoints by using flow cytometry following multicolor staining. The blockade of immune checkpoint by using neutralizing antibodies was performed to assess their role in PMA-induced THP-1-differentiated macrophages.
Upon the inducible macrophage differentiation caused by PMA, increased expression levels of CD11b and CD68 were measured and characterized according to their adherent phenotype accompanied by the generation of cellular complexity. While the cell growth rate was abolished post-differentiation, some cells underwent cell death. Notably, we found increases in the expression of programmed cell death protein 1, also known as PD-1 (CD279), and its ligand PD-L1 (CD274), mainly in differentiated M (CD68CD11b) macrophages. However, neutralizing PD-L1/PD-1 neither blocked THP-1 cell differentiation toward macrophages nor inhibited macrophage polarization in M and M. In specializing macrophages, a decrease both in CD274 and CD279 was found in M.
These results revealed the inducible expression of PD-L1/PD-1 in PMA-induced THP-1-differentiated M macrophages followed by a decrease in M macrophages.
佛波醇12 -肉豆蔻酸酯13 -乙酸酯（PMA）诱导人单核细胞THP - 1细胞分化是一种用于制备静息巨噬细胞（M）以使其向巨噬细胞的不同功能特化方向极化的实验模型。
在本研究中，我们通过多色染色后使用流式细胞术检测免疫检查点的表达。使用中和抗体阻断免疫检查点以评估它们在PMA诱导的THP - 1分化巨噬细胞中的作用。
在PMA诱导巨噬细胞分化后，检测到CD11b和CD68的表达水平增加，并根据其贴壁表型进行表征，同时伴随着细胞复杂性的产生。虽然分化后细胞生长速率消失，但一些细胞发生了细胞死亡。值得注意的是，我们发现程序性细胞死亡蛋白1（也称为PD - 1，CD279）及其配体PD - L1（CD274）的表达增加，主要在分化的M（CD68CD11b）巨噬细胞中。然而，中和PD - L1/PD - 1既未阻断THP - 1细胞向巨噬细胞的分化，也未抑制M和M中的巨噬细胞极化。在特化巨噬细胞中，M中发现CD274和CD279均减少。
这些结果揭示了PD - L1/PD - 1在PMA诱导的THP - 1分化的M巨噬细胞中可诱导表达，随后在M巨噬细胞中减少。
