GPR84
GPR84 is activated by medium-chain FFAs (MCFAs) with 9-14 carbons. It is expressed mainly in the immune-related tissues, such as thymus, spleen, bone marrow, and peripheral blood leukocytes, and is significantly upregulated in monocytes/macrophages upon lipopolysaccharide (LPS) stimulation. In activated T cells, GPR84 has been found to regulate early interleukin 4 (IL-4) gene expression[1].
[1] J Wang et al. Medium-chain fatty acids as ligands for orphan G protein-coupled receptor GPR84. J Biol Chem. 2006 Nov 10;281(45):34457-64.