Molecular Classification
Glycoprotein, Membrane protein, Complement regulatory protein
Other Names
Decay Accelerating Factor, DAF, Cromer blood group antigen
Disease Roles
Paroxysmal nocturnal hemoglobinuria (PNH)Hemolytic anemiaTumorigenesis

Complement Decay-Accelerating Factor Overview

Complement decay-accelerating factor (CD55), also known as DAF, is a membrane-bound glycoprotein that protects host cells from autologous complement-mediated lysis. It accelerates the decay of C3 and C5 convertases in both classical and alternative pathways of complement activation. CD55 is broadly expressed on hematopoietic cells, endothelium, and epithelium and plays a role in various diseases, including paroxysmal nocturnal hemoglobinuria (PNH).

Mechanism of Action

Accelerates the decay of C3 and C5 convertases, thereby inhibiting the complement cascade.

Biological Functions

Complement regulation
Inhibition of C3 convertase
Inhibition of C5 convertase
Protection of host cells from complement-mediated lysis
Immune regulation

Disease Associations

Paroxysmal nocturnal hemoglobinuria (PNH)
Hemolytic anemia
Tumorigenesis
Cromer blood group system related disorders
Infection

Safety Considerations

  • Potential for increased susceptibility to infection if CD55 function is excessively inhibited.
  • Potential role in promoting tumorigenesis.