|Detection of TREM‑1 in Human Blood Granulocytes by Flow Cytometry. Human peripheral blood granulocytes were stained with Mouse Anti-Human TREM‑1 Alexa Fluor® 488‑conjugated Monoclonal Antibody (Catalog # FAB1278G, filled histogram) or isotype control antibody (Catalog # IC002G, open histogram). View our protocol for Staining Membrane-associated Proteins.|
TREM-1 (Triggering Receptor Expressed on Myeloid cells) is a type I transmembrane protein having a single Ig-like domain. It associates with the adapter protein, DAP12, to deliver an activating signal. Several other TREM family members have been reported that are structurally similar but share less than 30% amino acid identity. TREM-1 is expressed on blood neutrophils and a subset of monocytes, and expression is up-regulated by bacterial LPS. The natural ligand for TREM-1 has not been identified. However, engagement of TREM-1 with an agonist monoclonal antibody leads to expression of IL-8, MCP-1, and TNF-alpha, suggesting that this receptor plays an important role in inflammatory responses. TREM-1 is expressed at high levels on neutrophils of patients with microbial sepsis and in mice with LPS-induced shock. Blockade of TREM-1 with a TREM-1/Fc fusion protein protected mice against LPS-induced shock. Human and mouse TREM-1 share approximately 42% amino acid sequence homology (1-3).