Complement System: The complement system is a complex network of proteins and pathways involved in the innate immune response. It serves as an extra barrier...
Complement System:
The complement system is a complex network of proteins and pathways involved in the innate immune response. It serves as an extra barrier against pathogens, aiding the immune system in identifying and eliminating harmful invaders. The system is activated by a variety of stimuli, including pathogens, damaged cells, and cytokines.
Key Components:
C1q: The first protein to be activated, C1q is produced by macrophages and dendritic cells and binds to a pathogen or damaged cell surface.
C2: C2 is generated by activated macrophages, dendritic cells, and mast cells and is responsible for forming membrane attack complexes (MACs). MACs are proteins that can directly kill pathogens.
C3: C3 is produced by the activation of macrophages, dendritic cells, and basophils. It is the central protein of the complement system and is responsible for triggering the cascade of events leading to the formation of C5.
C4-C5: These proteins are generated by activated platelets and are essential for the formation of the MACs.
C6-C9: These proteins are generated by activated B cells and are responsible for the activation of C3.
Complement Cascade:
When a pathogen or damaged cell is recognized by the complement system, a series of events unfolds, leading to the formation of a membrane attack complex. The cascade involves the activation of C1q, C2, C3, C4, and C5 proteins, ultimately leading to the formation of C6-C9. These proteins form a pore in the pathogen's membrane, allowing phagocytic cells to enter and destroy the pathogen