Complement component 6 (C6)

Complement component 6 (C6) is a vital serum glycoprotein that plays a central role in the terminal phase of the complement cascade, an essential part of the innate immune system. It is a member of the membrane attack complex/perforin (MACPF) superfamily and serves as the initial protein to bind the C5b fragment, facilitating the recruitment of C7, C8, and C9 to form the Membrane Attack Complex (MAC). This complex creates transmembrane pores in target cells, leading to the osmotic lysis of invading pathogens, particularly Gram-negative bacteria such as Neisseria meningitidis. Excessive or dysregulated activity of C6 and the resulting MAC can cause significant self-tissue damage, contributing to the pathogenesis of diseases like paroxysmal nocturnal hemoglobinuria (PNH) and atypical hemolytic uremic syndrome (aHUS). Consequently, C6 has emerged as a promising therapeutic target, with investigational monoclonal antibodies being developed to selectively block MAC assembly while potentially sparing upstream complement functions like opsonization.

Other names

C6Complement C6