背景：CD200 (OX-2 antigen) is a type-1 membrane glycoprotein containing two extracellular Ig-like domains. CD200 a highly conserved type I membrane glycoprotein that is expressed on a variety of cell types including thymocytes, some T cells, endothelial and follicular dendritc cells, B cells, and brain tissue (neurons); but not on NK cells, granulocytes, monocytes, or macrophages. CD200 costimulates T cell proliferation. It may regulate myeloid cell activity in a variety of tissues. CD200 is the ligand for CD200 receptor (CD200R). The CD200 Receptor is restricted to myeloid cells, and it is believed that its engagement with CD200 results in inhibition and/or downregulation of myeloid cell activity. Blocking of CD200/CD200R interactions decreases myeloid cell inhibitory thresholds which results in enhanced immune activation.
![APC Anti-Mouse CD200 Antibody[OX-90] 100*2Tests](https://aimg.as-1.co.jp/c/86/3975/03/86393868.jpg)