AIM/CD5L: A Key protein in the control of immune homeostasis and inflammatory disease

Abstract

CD5L, a soluble protein belonging to the scavenger receptor cysteine-rich superfamily, is expressed mostly by macrophages in both lymphoid and inflamed tissues. The expression of this protein is transcriptionally controlled by liver X receptors, members of the nuclear receptor family that play major roles in lipid homeostasis. Research undertaken over the last decade has uncovered critical roles of CD5L as a pattern recognition receptor of bacterial and fungal components and in the control of key mechanisms in inflammatory responses, with involvement in processes such as infection, atherosclerosis, and cancer. In this review, we summarize the current knowledge of CD5L, its roles at the intersection between lipid homeostasis and immune response, and its potential use as a diagnostic biomarker in a variety of diseases, such as tuberculosis and liver cirrhosis.