C1QB

C1QB, Complement C1q Subcomponent B, is a component of the C1 complex of the serum complement system.C1QB, along with the C1QA and C1QC chains, binds to two precursor enzymes, C1r and C1s, to form C1, which is the first component of the serum complement system.C1QB consists of 18 polypeptide chains, including six A chains, six B chains and 6 C chains, each containing an N-terminal collagen-like region and a C-terminal C1q spherical domain.The mechanism of action of C1QB involves the interaction of its spherical head with the Fc region of immune complexes, which triggers a complement cascade reaction leading to the attack and clearance of pathogens.

C1QB plays a crucial role in host defence, participating in the recognition and clearance of immune complexes, promoting phagocytosis , regulates cytokine production, and influences T-lymphocyte maturation. In addition, C1QB is involved in tissue repair, tumour immunosurveillance, and homeostatic regulation of the central nervous system.The function of C1QB is important for the maintenance of immune homeostasis and the prevention of autoimmune diseases, and its roles in a wide range of physiological and pathological processes suggest a complex role in immunoregulatory and cellular processes.