Characterization of bovine cDNA encoding triggering receptor expressed on myeloid cells 1 (TREM-1)

Triggering receptor expressed on myeloid cells 1 (TREM-1) is a type I transmembrane receptor of the immunoglobulin superfamily expressed predominantly on neutrophils and monocytes. TREM-1 induces the expression of inflammatory cytokines and adhesion molecules, and augments osteoclast, microglia, oligodendrocyte, and dendritic cell differentiation. Here, we report the cloning of TREM-1 from bovine bone marrow cells. Full-length bovine TREM-1 cDNA is 1202 base pairs in length and encodes a predicted 232 amino acid peptide. Comparative analyses showed that bovine TREM-1 has 48 to 61% amino acid identity with other TREM-1 proteins, sharing the greatest identity with porcine TREM-1. Cysteine residues characteristic of the immunoglobulin superfamily were conserved in bovine TREM-1 and RT-PCR analysis revealed diverse mRNA tissue expression for bovine TREM-1. Molecular cloning of bovine TREM-1 extends the repertoire of bovine pattern recognition receptors and provides information important for investigating their role in bovine innate immunity.