Purity >96% by HPLC. TREM-1 peptide. The triggering receptor expressed on myeloid cells (TREM)-1 is a recently discovered cell-surface molecule that has been identified both on human and murine polymorphonuclear neutrophils and mature monocytes. It belongs to the immunoglobulin superfamily and activates downstream signaling pathways with the help of an adaptor protein called DAP12. It has been shown that the expression of TREM-1 was greatly up-regulated on neutrophils and monocytes in the presence of such bacteria as Pseudomonas aeruginosa or Staphylococcus aureus, both in cell culture and in tissue samples from patients with infection.