Complement component 7 (C7)

Complement component 7 (C7) is a single-chain glycoprotein and an essential component of the terminal complement pathway, specifically forming part of the membrane attack complex (MAC) together with C5b, C6, C8, and C9[1][3][4]. C7 binds to the C5bC6 complex and transitions it to an amphiphilic state, allowing insertion into the pathogen membrane and serving as the anchor for subsequent MAC proteins, ultimately leading to target cell lysis[1][3][4]. C7 is primarily produced by granulocytes, endothelial, and bone marrow-derived cells, rather than the liver, and modulates the local formation of the MAC[2][5]. Beyond its canonical lytic function, C7 may bind clusterin (CLU) to form circulating complexes with regulatory and possibly anti-inflammatory activity[2][5], and has been implicated in non-traditional functions such as tumorigenesis and infectious or autoimmune diseases. Mutations or deficiencies in C7 lead to increased vulnerability to invasive infections, particularly by Neisseria species[3][4]. There are no widely approved drugs targeting C7 specifically, but complement pathway inhibition is a field of active research for diseases of complement dysregulation[1][4].

Other names

Complement C7complement component 7C7complement component C7

Inhibition of MAC assembly by preventing C7 binding (experimental, not clinically available). Potential modulation via antibody-based therapies directed at C7 or its complexes (experimental).