Annexin A2 Enhances Complement Activation by Inhibiting Factor H

Annexin A2 Enhances Complement Activation by Inhibiting Factor H.

Factor H is a circulating protein that regulates activation of the alternative pathway (AP) of complement. Mutations and genetic variations of factor H are associated with several AP-mediated diseases, highlighting the critical role of factor H in AP regulation. AP-mediated inflammation is typically triggered by illness or tissue injury, however, and tissue injury can trigger AP activation in i...

Interaction of uromodulin and complement factor H enhances C3b inactivation

Recent studies suggest that uromodulin plays an important role in chronic kidney diseases. It can interact with several complement components, various cytokines and immune system cells. Complement factor H (CFH), as a regulator of the complement alternative pathway, is also associated with various renal diseases. Thus, we have been suggested that uromodulin regulates complement activation by in...

Annexin A2 is a soluble mediator of macrophage activation.

On the surface of the macrophage, annexin A2 tetramer (A2t) serves as a docking protein or recognition element for bacterial and viral pathogens. Plasma levels of free A2t have been reported to increase following infection, although the mechanistic significance of this observation is unclear. Although annexin A2 had generally been thought to play an anti-inflammatory role, soluble A2t stimulate...

Human Factor H-Related Protein 2 (CFHR2) Regulates Complement Activation

Mutations and deletions within the human CFHR gene cluster on chromosome 1 are associated with diseases, such as dense deposit disease, CFHR nephropathy or age-related macular degeneration. Resulting mutant CFHR proteins can affect complement regulation. Here we identify human CFHR2 as a novel alternative pathway complement regulator that inhibits the C3 alternative pathway convertase and termi...

Complement factor H