The role of adenosine A1 receptor on immune cells.

ABSTRACT

BACKGROUND: Adenosine, acting as a regulator by mediating the activation of G protein-coupled adenosine receptor families (A1, A2A, A2B, and A3), plays an important role under physiological and pathological conditions. As the receptor with the highest affinity for adenosine, the role of adenosine A1 receptor (A1R)-mediated adenosine signaling pathway in the central nervous system has been well addressed. However, functions of A1R on immune cells are less summarized. Considering that some immune cells express multiple types of adenosine receptors with distinct effects and varied density, exogenous adenosine of different concentrations may induce divergent immune cell functions. MATERIALS AND METHODS: The literatures about the expression of A1R and its regulation on immune cells and how it regulates the function of immune cells were searched on PubMed and Google Scholar. CONCLUSION: In this review, we discussed the effects of A1R on immune cells, including monocytes, macrophages, neutrophils, dendritic cells, and microglia, and focused on the role of A1R in regulating immune cells in diseases, which may facilitate our understanding of the mechanisms by which adenosine affects immune cells through A1R.