Anti-C4a antibody

Supplementary info

This supplementary information is collated from multiple sources and compiled automatically.

Activity summary

Complement C4a also known as C4a anaphylatoxin is a component of the complement system with a molecular mass of approximately 9 kDa. This small protein originates from the proteolytic cleavage of complement component C4 which contributes to immune system activation. C4a is mainly expressed in the liver but can also be produced by other tissues during inflammation. It serves as a chemoattractant recruiting immune cells to sites of infection helping initiate a response against pathogens.

Biological function summary

Complement C4a acts as an anaphylatoxin participating in the complex immune system response. Anaphylatoxins like C4a C3a and C5a contribute to the inflammatory process by inducing smooth muscle contraction increasing vascular permeability and triggering histamine release from mast cells and basophils. C4a complements the activities of other complement components playing an important role in modulating inflammation and defense mechanisms in the body.

Pathways

The activation of C4a is an important step within the classical and lectin pathways of complement activation. These pathways involve the recognition and elimination of pathogens and unwanted cells. C4a along with its related proteins C4b and components C2 and C3 facilitates the formation of C3 convertase which amplifies the response and further clears pathogens. C4a also interacts with complement inhibitors which regulate these pathways to prevent excessive tissue damage during inflammation.

Associated diseases and disorders

C4a anaphylatoxin has associations with autoimmune diseases and angioneoplasm. Changes in serum levels of C4a are observed in conditions like systemic lupus erythematosus where it may contribute to tissue damage. High C4a levels can correlate with disease activity and severity. Additionally C4a alongside other anaphylatoxins like C3a and C5a might play a role in angiogenesis influencing tumor progression and angiogenesis-related disorders serving as a potential biomarker for disease severity and prognosis.