Antibodies

Immunoglobulins, also referred to as antibodies, are protective multimeric molecules produced by the immune system in response to the presence of a foreign intruder, also referred to as an antigen. 

Antibodies produced and secreted by plasma B cells in response to the foreign intruder, recognize and interact with the antigens in order to neutralize and ultimately to remove them from the body. The region of the antigen that makes direct contact to the antibody, is referred to as the antigenic determinant or the epitope. Upon antigen encounter, different effector functions are mediated dependent on the specific antibody isotype. Antibodies produced to the specific antigen remain in circulation for several months, providing extended immunity against that particular antigen.

Occasionally, breakdown of self-tolerance takes place, where activated naive autoreactive B cells produce and secrete antibodies to self-components (autoantigens), also referred to as autoantibodies. Autoantibodies may be associated with one or a specific group of autoimmune diseases. These autoantibodies may function as simple biomarkers or be pathogenic, dependent on the type of disease associated with. 

In addition to naturally occurring antibodies, antibodies can be synthesized in expression systems, where they in theory can be generated to any target of choice. Based on this, antibodies have become a propound reagent in research, diagnostics and therapeutics.