What does C1q stand for?
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.
What does C1q protein do?
Complement protein C1q, the recognition molecule of the classical pathway, performs a diverse range of complement and non-complement functions. It can bind various ligands derived from self, non-self, and altered self and modulate the functions of immune and non-immune cells including dendritic cells and microglia.
Which cells express C1q?
4. Discussion. Macrophages and immature dendritic cells have been described as the main producers of C1q (Loos et al., 1989, Castellano et al., 2004).
Where is C1q located?
The C1q molecule is primarily synthesised in cells of myeloid origin including monocytes, macrophages, dendritic cells, but also by other cells such as Kupffer cells, glial cells, mast cells, trophoblasts, endothelial cells, epithelial cells and fibroblasts.
Where is C1q from?
C1q is assembled from three polypeptide chains (A, B and C) each containing an N-terminal collagen-like sequence and a C-terminal globular gC1q module. A particular inter-chain disulfide pattern results in a basic subunit comprised of two heterotrimeric collagen-like stalks prolonged by globular domains (C1q–GR).
What is C1q antibody?
This test is used to monitor proliferative lupus nephritis (LN) disease activity and help assess the likelihood of LN flares in individuals with systemic lupus erythematosus.
Is C1q an Opsonin?
C1q functions as an opsonin for the physiological removal of apoptotic cells.
What do anaphylatoxins do?
The anaphylatoxins are low molecular weight peptides (∼10 kDa) responsible for the acute inflammatory response including mediating migration and activation of a range of immunocompetent cells to the site of insult, such as a pathogen invasion site, tissue injury, etc (Klos et al., 2009).
What does a high C1q mean?
The presence of C1q antibodies in SLE is associated with severe illness, often with renal involvement. The highest concentrations are associated with disease relapse, when the level of C1q simultaneously is low. High concentration of antibodies usually decreases rapidly in response to treatment.
What does low C1q mean?
C1q deficiency is a rare immunodeficiency, which is strongly associated with the development of systemic lupus erythematosus (SLE). A mutation in one of the C1q genes can either lead to complete deficiency or to low C1q levels with C1q polypeptide in the form of low-molecular weight (LMW) C1q.