Selective Chemokine Receptor Usage by Central Nervous System Myeloid Cells in CCR2-Red Fluorescent Protein Knock-In Mice

BACKGROUND: Monocyte subpopulations distinguished by differential expression of chemokine receptors CCR2 and CX3CR1 are difficult to track in vivo, partly due to lack of CCR2 reagents. METHODOLOGY/PRINCIPAL FINDINGS: We created CCR2-red fluorescent protein (RFP) knock-in mice and crossed them with CX3CR1-GFP mice to investigate monocyte subset trafficking. In mice with experimental autoimmune encephalomyelitis, CCR2 was critical for efficient intrathecal accumulation and localization of Ly6C(hi)/CCR2(hi) monocytes. Surprisingly, neutrophils, not Ly6C(lo) monocytes, largely replaced Ly6C(hi) cells in the central nervous system of these mice. CCR2-RFP expression allowed the first unequivocal distinction between…

• NM
  National Multiple Sclerosis Society
• MS
  Multiple Sclerosis Society
• NI
  National Institutes of Health

  Award: R01NS32151