CD55 / DAF Antikörper ( FITC )

CD55, also well known as decay-accelerating factor (DAF), is a member of the RCA (regulators of complement activation) family characterized by four to 30 SCRs (short consensus repeats) in their plasma-exposed regions. This 70-75 kDa glycoprotein CD55 containing four SCR modules is involved in the regulation of the complement cascade. It interferes with the functions of C3 and C5 convertases in both the classical and alternative pathways by preventing the assembly of the C3bBb complex or accelerating the disassembly of preformed convertase, and thus disrupts the cascade and protects the host cells from damage. Antigens present on the DAF constitute determinant for the Cromer blood group system. DAF has been identified as a ligand for an activation-associated, seven-transmembrane lymphocyte receptor, CD97, which is a receptor mediating attachment and infection of several viruses and bacteria. In addition, it has been shown that DAF regulates the interplay between complement and T cell immunity in vivo, and thus may be implicated in immune and tumor biology. There are two variants of CD55 encoded by alternatively spliced transcripts, the predominant variant is a GPI-anchored membrane form ubiquitously expressed on cells exposed to plasma complement proteins, whereas a soluble form present at much lower level.

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