In this strain, a monomeric red fluorescent protein (RFP) sequence replaces the coding sequence of the chemokine (C-C motif) receptor 2 (Ccr2) gene, abolishing gene function. CCR2 is a chemokine receptor expressed on monocytes which directs their recruitment to sites of inflammation found in diseases such as multiple sclerosis, atherosclerosis, rheumatoid arthritis, and experimental autoimmune encephalitis (EAE), following activation by monocyte chemoattractant proteins (MCPs). CCR2 is essential to innate and adaptive immune responses during injury repair. Homozygous mice are viable, fertile, normal in size, and do not display any gross physical or behavioral abnormalities. In these mice RFP expression is seen in circulating monocytes, T cells, and natural killer cells. They exhibit a reduction in monocyte recruitment during thioglycolate-induced peritonitis and EAE. These mice may be useful for studying the role of CCR2 during monocyte recruitment to sites of inflammation.
