A Novel Role for CD55 in Granulocyte Homeostasis and Anti-Bacterial Host Defense

In addition to its complement-regulating activity, CD55 is a ligand of the adhesion class G protein-coupled receptor CD97; however, the relevance of this interaction has remained elusive. We previously showed that mice lacking a functional CD97 gene have increased numbers of granulocytes. developed less bacteremia and died later after infection.Collectively, these data suggest that complement-independent interaction of CD55 with CD97 is functionally relevant and involved in granulocyte homeostasis and host defense