Dissecting the roles of TREM-1 and TREM-2 in the human macrophage cell line THP-1

• Main Authors: Chun-Ting Chen, 陳俊廷
• Other Authors: Nien-Jung Chen
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/hgm7cy

碩士 === 國立陽明大學 === 微生物及免疫學研究所 === 105 === Triggering receptor expressed on myeloid cells (TREM), is a new family of surface receptors belongs to immunoglobulin like superfamily. TREM-1 and TREM-2 are two subtypes in TREM family. Both TREM-1 and TREM-2 express on monocyte-macrophage lineage and involve in diversity of immune response. TREM-1 can amplify inflammatory response by synergizing with toll-like receptor (TLR), and TREM-2 displays an anti-inflammatory regulator. However, current evidences regarding the roles of TREM-1 and TREM-2 on macrophage are mainly investigated by the studies in mouse model. The roles of TREM-1 and TREM-2 in human macrophage are still unclear. Therefore we following investigate the roles of human TREM-1 and TREM-2 in human macrophage. We generated TREM-1 and TREM-2-depleted human macrophages by using CRISPR/Cas9 system. Through T/A cloning and DNA sequencing, we confirmed TREM-1 and TREM-2-depleted THP-1 cells had the indel (INsertion/DELetion) mutations. Simultaneously, we also detected TREM-1-depleted THP-1 cells vanished TREM-1 mRNA transcription and surface protein expression. Similarly, TREM-2-depleted THP-1 cells eliminated TREM-2 protein expression. These results provided the evidence to confirm depletions of TREM-1 and TREM-2 in gene-edited THP-1 cells were success. We identified both human TREM-1 and TREM-2 depletion did not affect cell proliferation and survival in THP-1 cell line. TREM-1 depletion might slightly attenuation of M1 (classical macrophage) or inflammatory markers (IL-1b and TNFα) increases in M1 polarized condition, and TREM-2 depletion amplified M1 markers (IL-1b and TNFα) increases in M1 polarized condition. Moreover human TREM-2 depletion also impaired the capability of oxidized-low density lipoprotein (ox-LDL) uptake, which further confirmed our hypothesis previously observed in TREM-2 knockout mice. Taken together, THP-1 cell line characters would induce difference results from human PBMC or mouse BMDM, we also considered that TREM-1- and TREM-2- depleted THP-1 might be a potential human macrophage model. And through this model, we can further explore the roles of human TREM-1 and TREM-2 in diversity immune response.