Antibody functions

Antibodies play a part in:

Humoral immunity

Antibodies are the functional basis of humoral immunity. In the humoral immune response, antibodies are produced by B cells. These antibodies destroy pathogens and prevent the spread of intracellular infection. Antibodies can be found in blood, gastric and mucus secretions, and in breast milk.

Passive immunity

Antibodies can be transferred from one individual to another to temporarily protect the other against an infectious disease; this is known as passive immunity.

Opsonization

Antibodies in the aforementioned bodily fluids can bind to pathogens expressing foreign antigens and mark them for destruction by phagocytes before they can infect our cells. This is called opsonization.

Neutralization

Neutralization occurs when antibodies block the key sites on a pathogen, thus preventing the pathogen from entering and infecting host cells.

Complement fixation

In a process called complement fixation, IgM and IgG bind to foreign antigens and provide sites for complement proteins to bind to. This combination of antibodies and complement proteins enhances opsonization.

See also: Antibody