Anti-C3d antibody [7C10]

Supplementary info

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

Activity summary

C3d a fragment of the complement component C3 plays an important role in the immune response. It weighs around 35 kDa. This protein fragment forms after the cleavage of C3 and is found in the bloodstream. Researchers often refer to C3d in the context of complement activation using terms such as 'C3d complement' and 'anti-C3d-positive'. C3d is expressed extensively on cell surfaces where it binds to receptors modulating immune cell responses.

Biological function summary

The fragment plays a significant role in the regulation of immune activation processes. C3d is part of the complement system which is a complex network of proteins contributing to innate immunity. This fragment tags pathogens for destruction and acts as a bridge for enhancing adaptive immunity by linking innate and adaptive immune responses. Interaction with the complement receptor type 2 (CR2) on B cells and follicular dendritic cells is essential for its immunological function.

Pathways

C3d participates in the complement activation pathway and is an important player in the alternative pathway of complement activation. Through these pathways it is linked to proteins such as Factor B and Factor D further influencing the cascade leading to pathogen elimination. The amplification loop involving C3 and its fragments including C3d enhances the immune response emphasizing its connectivity within these pathways.

Associated diseases and disorders

The role of C3d becomes particularly relevant in conditions like systemic lupus erythematosus (SLE) and age-related macular degeneration (AMD). Abnormal deposition of C3d and its fragments associates with inflammatory disorders such as SLE. Connection to CR2 is significant as the CR2-C3d complex can exacerbate these diseases. Understanding these interactions helps in targeting therapies for related autoimmune and inflammatory conditions.