Therapeutic Potential of Targeting TREM-1 in Inflammatory Diseases and Cancer

The triggering receptor expressed on myeloid cells (TREM)-1 is a member of the Ig-like immunoregulatory receptor family and a major amplifier of innate immune responses. TREM- 1 has been implicated in the development and perpetuation of a number of inflammatory disorders, and soluble TREM-1 levels are a clinically valuable diagnostic and prognostic biomarker in patients with sepsis and other types of acute and chronic inflammation- associated diseases, easily detectable in biological fluids. High TREM-1 expression in macrophages infiltrating human tumors and increased concentrations of soluble TREM-1 also correlate with aggressive tumor behavior and recurrence and are a relevant independent predictor of poor patient survival. Pharmacological inhibition of TREM-1 has proven effective in preclinical mouse models of infectious and non-infectious inflammatory disorders and malignancies, conferring survival advantages and protecting from organ damage or tumor growth by attenuating inflammatory responses. This review aims at providing a comprehensive overview of the state of the art on TREM-1 research. We review the literature addressing TREM-1 role in the amplification of myeloid cell inflammatory responses at pathologic sites and its relevance in the development, severity, and progression of inflammatory diseases and cancer. Furthermore, we discuss recent advances in the pharmacological use of TREM-1 inhibitors in mouse preclinical models, emphasizing their potential in new strategies for the treatment of acute and chronic inflammatory conditions and for therapeutic intervention in cancer. This information will be of value to investigators in the field of pharmacology, drawing attention to novel therapeutic opportunities to complement current treatment approaches. Keywords: Innate immune cells, immunoregulatory receptors, triggering receptor expressed on myeloid cells, inflammation, inflammatory diseases, cancer, disease models, therapy.