CFH Antibody - #DF6889

Glycoprotein that plays an essential role in maintaining a well-balanced immune response by modulating complement activation. Acts as a soluble inhibitor of complement, where its binding to self markers such as glycan structures prevents complement activation and amplification on cell surfaces. Accelerates the decay of the complement alternative pathway (AP) C3 convertase C3bBb, thus preventing local formation of more C3b, the central player of the complement amplification loop. As a cofactor of the serine protease factor I, CFH also regulates proteolytic degradation of already-deposited C3b. In addition, mediates several cellular responses through interaction with specific receptors. For example, interacts with CR3/ITGAM receptor and thereby mediates the adhesion of human neutrophils to different pathogens. In turn, these pathogens are phagocytosed and destroyed.

Sulfated on tyrosine residues.

Secreted.

Expressed in the retinal pigment epithelium (at protein level). CFH is one of the most abundant complement components in blood where the liver is the major source of CFH protein in vivo. in addition, CFH is secreted by additional cell types including monocytes, fibroblasts, or endothelial cells.

Homodimer. Forms also homooligomers. Interacts with complement protein C3b; this interaction inhibits complement activation. Interacts with complement protein C3d. Interacts with CR3/ITGAM; this interaction mediates adhesion of neutrophils to pathogens leading to pathogen clearance. Interacts with complement factor I.

(Microbial infection) Interacts with West nile virus non-structural protein 1 (NS1); this interaction leads to the degradation of C3.

(Microbial infection) Interacts with Neisseria meningitidis protein fHbp.

(Microbial infection) Interacts with Borrelia burgdorferi outer surface protein E/OspE; this interaction recruits complement regulator factor H onto the bacterial surface to evade complement-mediated cell lysis.

(Microbial infection) Interacts with Streptococcus pneumoniae protein virulence factor choline-binding protein A/CbpAN; this interaction enables Streptococcus pneumoniae to evade surveillance by human complement system.

(Microbial infection) Interacts with Staphylococcus aureus surface protein serine-aspartate repeat protein E/SdrE; this interaction sequesters CFH on the surface of S. aureus for complement evasion.

(Microbial infection) Interacts with Staphylococcus aureus protein Sbi; this interaction inhibits the complement activation of the alternative pathway.

Sushi 1-3 domain represents the minimal unit capable of cofactor activity (PubMed:18252712). The property to discriminate self surfaces from non-self surfaces depends on the C-terminal region made of Sushis 19-20 (PubMed:21285368).