Complement C5a anaphylatoxin (C5a) (C5a)

Complement C5a anaphylatoxin is a potent pro-inflammatory peptide generated during the activation of the complement system, specifically through the cleavage of complement component C5 by C5 convertases (Ward, 2004). As a key mediator of the innate immune response, C5a acts as a powerful chemoattractant for neutrophils, monocytes, and macrophages, facilitating their recruitment to sites of injury or infection (Giamarellos-Bourboulis et al., 2020). It exerts its biological effects by binding to two receptors: the G protein-coupled receptor C5aR1 (CD88) and the non-signaling or regulatory receptor C5aR2 (UniProt Consortium, 2023). Overproduction of C5a is linked to severe inflammatory conditions, including sepsis, ANCA-associated vasculitis, and acute lung injury, where it drives cytokine storms and tissue damage (PubMed, 2021). Therapeutic agents like the monoclonal antibody vilobelimab are designed to specifically neutralize C5a, thereby blocking its inflammatory signaling while leaving the terminal complement pathway (C5b-9) intact for pathogen defense (FDA, 2023). This selective targeting provides a strategic advantage in treating hyper-inflammatory states without compromising the body's ability to form the membrane attack complex.

Other names

C5aComplement component 5aAnaphylatoxin C5a

Neutralization of the C5a ligand to prevent its interaction with C5a receptors (C5aR1 and C5aR2), thereby inhibiting downstream pro-inflammatory signaling (DrugBank, 2023).