TO THE EDITOR I read with a great interest the paper by Gonzalez-Roldan et al. The authors reported on the pattern expression of TREM-1 during sepsis and major abdominal surgery as compared to healthy controls and con...TO THE EDITOR I read with a great interest the paper by Gonzalez-Roldan et al. The authors reported on the pattern expression of TREM-1 during sepsis and major abdominal surgery as compared to healthy controls and concluded that展开更多
The triggering receptor expressed on myeloid cells-1(TREM-1)is a receptor expressed on innate immune cells.By promoting the amplification of inflammatory signals that are initially triggered by Toll-like receptors(TLR...The triggering receptor expressed on myeloid cells-1(TREM-1)is a receptor expressed on innate immune cells.By promoting the amplification of inflammatory signals that are initially triggered by Toll-like receptors(TLRs),TREM-1 has been characterized as a major player in the pathophysiology of acute and chronic inflammatory diseases,such as septic shock,myocardial infarction,atherosclerosis,and inflammatory bowel diseases.However,the molecular events leading to the activation of TREM-1 in innate immune cells remain unknown.Here,we show that TREM-1 is activated by multimerization and that the levels of intracellular Ca 2+release,reactive oxygen species,and cytokine production correlate with the degree of TREM-1 aggregation.TREM-1 activation on primary human monocytes by LPS required a two-step process consisting of upregulation followed by clustering of TREM-1 at the cell surface,in contrast to primary human neutrophils,where LPS induced a rapid cell membrane reorganization of TREM-1,which confirmed that TREM-1 is regulated differently in primary human neutrophils and monocytes.In addition,we show that the ectodomain of TREM-1 is able to homooligomerize in a concentration-dependent manner,which suggests that the clustering of TREM-1 on the membrane promotes its oligomerization.We further show that the adapter protein DAP12 stabilizes TREM-1 surface expression and multimerization.TREM-1 multimerization at the cell surface is also mediated by its endogenous ligand,a conclusion supported by the ability of the TREM-1 inhibitor LR12 to limit TREM-1 multimerization.These results provide evidence for ligand-induced,receptor-mediated dimerization of TREM-1.Collectively,our findings uncover the mechanisms necessary for TREM-1 activation in monocytes and neutrophils.展开更多
TREM-1(triggering receptor expressed on myeloid cells-1)is a transmembrane receptor expressed by innate immune cells,including endothelial cells and platelets.TREM-1 is a crucial mediator of septic shock that acts by ...TREM-1(triggering receptor expressed on myeloid cells-1)is a transmembrane receptor expressed by innate immune cells,including endothelial cells and platelets.TREM-1 is a crucial mediator of septic shock that acts by synergizing with Toll-like receptors(TLRs)to amplify the inflammatory responses to pathogens,thus promoting sepsis-induced immune dysregulation and organ dysfunction[1,2,3].展开更多
文摘TO THE EDITOR I read with a great interest the paper by Gonzalez-Roldan et al. The authors reported on the pattern expression of TREM-1 during sepsis and major abdominal surgery as compared to healthy controls and concluded that
文摘The triggering receptor expressed on myeloid cells-1(TREM-1)is a receptor expressed on innate immune cells.By promoting the amplification of inflammatory signals that are initially triggered by Toll-like receptors(TLRs),TREM-1 has been characterized as a major player in the pathophysiology of acute and chronic inflammatory diseases,such as septic shock,myocardial infarction,atherosclerosis,and inflammatory bowel diseases.However,the molecular events leading to the activation of TREM-1 in innate immune cells remain unknown.Here,we show that TREM-1 is activated by multimerization and that the levels of intracellular Ca 2+release,reactive oxygen species,and cytokine production correlate with the degree of TREM-1 aggregation.TREM-1 activation on primary human monocytes by LPS required a two-step process consisting of upregulation followed by clustering of TREM-1 at the cell surface,in contrast to primary human neutrophils,where LPS induced a rapid cell membrane reorganization of TREM-1,which confirmed that TREM-1 is regulated differently in primary human neutrophils and monocytes.In addition,we show that the ectodomain of TREM-1 is able to homooligomerize in a concentration-dependent manner,which suggests that the clustering of TREM-1 on the membrane promotes its oligomerization.We further show that the adapter protein DAP12 stabilizes TREM-1 surface expression and multimerization.TREM-1 multimerization at the cell surface is also mediated by its endogenous ligand,a conclusion supported by the ability of the TREM-1 inhibitor LR12 to limit TREM-1 multimerization.These results provide evidence for ligand-induced,receptor-mediated dimerization of TREM-1.Collectively,our findings uncover the mechanisms necessary for TREM-1 activation in monocytes and neutrophils.
基金Septic shock patient samples from the Adrenoss-1 cohort(NCT02393781)were provided by Sphingotec,and statistical analyses were conducted by Oli Hartman and Joachim Struck(Sphingotec).
文摘TREM-1(triggering receptor expressed on myeloid cells-1)is a transmembrane receptor expressed by innate immune cells,including endothelial cells and platelets.TREM-1 is a crucial mediator of septic shock that acts by synergizing with Toll-like receptors(TLRs)to amplify the inflammatory responses to pathogens,thus promoting sepsis-induced immune dysregulation and organ dysfunction[1,2,3].
