The complement component 1q (or simply C1q) is a protein complex involved in the complement system, which is part of the innate immune system. C1q together with C1r and C1s form the C1 complex. Antibodies of the adaptive immune system can bind antigen, forming an antigen-antibody complex.

The first complement component, C1q, accomplishes a diverse range of complement-dependent and complement-independent functions in the immune response [1, 2]. It binds various ligands derived from self and non-self and modulates the functions of immune cells.

C1q is a multimeric protein that serves as the recognition unit of the C1 complex, the first component of the classical complement pathway. It consists of six heterotrimeric subunits, each composed of one C1qA, C1qB, and C1qC polypeptide chain.

Dec 1, 2021 · The increased levels of C1q are still incompletely understood but are suggested to modulate the adaptive immune response as C1q is known to impact on the maturation status of antigen-presenting cells and C1q impacts directly on T cells leading to decreased T-cell activity in high C1q conditions.

This component forms part of the complement system, a group of proteins that enhance (complement) the ability of antibodies and phagocytic cells to clear pathogens from an organism. C1Q specifically initiates the classical complement pathway, a critical part of the body's innate immune response.

Complement component C1q plays an important recognition role in adaptive, and innate, immunity through its ability to interact, via its six globular head regions, with both immunoglobulin and non-immunoglobulin activators of the complement system, ...

C1q is a complex glycoprotein assembled from 18 polypeptide chains, with a C-terminal globular head region that mediates recognition of diverse molecular structures, and an N-terminal collagen-like tail that mediates immune effector mechanisms.

Complement component C1q, the first component of this pathway, links the adaptive humoral immune response to the complement system by binding to antibodies complexed with antigens. C1q can, however, also bind directly to the surface of certain pathogens and thus trigger complement activation in the absence of antibody.

C1q recognizes and binds to immunoglobulin complexed to antigen and initiates the complement cascade. Congenital deficiencies of any of the early complement components (C1, C2, C4) results in an inability to clear immune complexes.

May 13, 2022 · As previously well reviewed 1, 2, 3, 4, the first complement component, C1q, is an ~460 kDa macromolecular glycoprotein that has a tulip-like structure and is found circulating in the blood.