Describe the mechanisms of action of antibodies

Question

What will be an ideal response?

Answer 1

Antibodies act against foreign antigens in many ways. In agglutination, several immunoglobulin (antibody) molecules bind two or more microbial cells together, causing them to clump. This process hinders the activity of pathogenic organisms and increases the chances that they will be phagocytized. Antibodies may neutralize toxins produced by pathogens by binding to critical portions of the toxins and preventing them from functioning against the body. Antibodies may bind to virus ligands or bacterial adhesions and prevent the pathogen from attaching to cells of the body. Antibodies also act as opsonins, which are molecules that stimulate phagocytosis. Binding of the antibody to foreign antigens on the surface of cells facilitates the action of natural killer lymphocytes. IgG antibody bound to antigen can become enzymatically active and produce hydrogen peroxide to damage and kill the microbe to which it is bound. IgG and IgM antibodies that have bound antigen can trigger the complement cascade. IgE antibodies trigger the release of chemicals which damage cells and inflammatory chemicals from eosinophils and basophils.
Bloom's Taxonomy: Comprehension
Section: Elements of Adaptive Immunity
Learning Outcome: 16.18