Immunology
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Triggering receptor expressed on myeloid cells 1 (TREM-1) is an activating receptor involved in inflammatory diseases and septic shock. The TREM-1 ligand(s) (TREM-1L) have not yet been identified. In this study, we performed a detailed analysis of the expression of mouse TREM-1 and its ligand(s). ⋯ This up-regulation on granulocytes was directly mediated by TLR ligands and required the adapter protein MyD88. In contrast to human, mouse platelets expressed TREM-1L neither under steady-state conditions nor after LPS injection in vivo. Our study reveals differential regulation of TREM-1 expression on mouse monocyte subpopulations and improves our understanding of the biological role of TREM-1 during disease.