OX2/CD200 is a broadly distributed cell surface glycoprotein that interacts with a receptor (CD200R) predominantly expressed on myeloid lineage cells [, ]. It is involved in regulation of macrophage function []. Interaction of CD200 with its receptor acts to suppress inflammatory responses [, , , ]. CD200 has been shown to play important roles in controlling autoimmunity, inflammation, the development and spread of cancer, hypersensitivity, and spontaneous fetal loss [].This entry also includes viral OX2 (vOX2). Viral OX2 is encoded by herpesvirurses and has significant homology with cellular OX2. Viral OX2 encodes a glycosylated cell surface protein which has been shown to target myeloid-lineage cells [].
This entry includes cell surface glycoprotein CD200 receptor 1-5 (CD200R1-5) from mice and CD200R1/CD200R1L from humans. CD200R is a family of inhibitory receptors principally affecting myeloid cell function []. Family members are receptors for the CD200/OX2 cell surface glycoprotein with potential activatory and inhibitory functions that may play important roles in immune regulation and balance [, ].
