The Complement System for Antibody Action
The complement system for antibody action. Complement is a system of nine different enzyme precursors (designated Cl to C9) which is normally found in plasma and other body fluids, but are also normally inactive enzymes. However, when an antibody combines with an antigen, antigen becomes the complement system activator. Just a few combination to activate antigen large number of enzyme precursor molecules in the first stage of the complement system, activated enzymes thus formed then many more enzymes in the later stages of the system. The activated enzymes then attack the invaders in various ways, initiate local tissue reactions, and provide protection against injury by the invader. Among the most important effects that occur are the following:
1. Lysis. Proteolytic enzymes digest the complement system portions of the cell membrane, thus disrupting cellular agents such as bacteria or other invading cells.
2. Opsonization and phagocytosis. Complement enzymes attack the surfaces of bacteria and other antigens, making them very susceptible to phagocytosis by neutrophils and tissue macrophages. This process is called opsonization. Often the number of bacteria can be destroyed in you into the hundreds.
3 Chemotaxis. One or more of the complement products cause chemotaxis of neutrophils and macrophages, there by increasing considerably the number of these phagocytes in the local region of the antigenic agent.
4. Agglutination. Complement enzymes also change the surfaces of some of the antigenic agents, so they are joined causing clumping.
5. Virus neutralization. Probably complement enzymes attack the molecular structure of viruses and suppress their virulence.
6. Inflamatorlos effects. The supplement produces a local inflammatory reaction, because of congestion, coagulation of protein in tissues and other aspects of the inflammatory process, which prevents the movement of invading agent through the tissues.