Summarizing Antibodies

Summary

Antibodies (immunoglobulins) are the molecules secreted from plasma cells that mediate the humoral immune response. There are five antibody classes; an antibody's class determines its mechanism of action and production site but does not control its binding specificity. Antibodies bind antigens via variable domains and can either neutralize pathogens or mark them for phagocytosis or activate the complement cascade.

Glossary

affinity

attraction of molecular complementarity between antigen and antibody molecules

antibody

protein that is produced by plasma cells after stimulation by an antigen; also known as an immunoglobulin

avidity

total binding strength of a multivalent antibody with antigen

cross reactivity

binding of an antibody to an epitope corresponding to an antigen that is different from the one the antibody was raised against

passive immunity

transfer of antibodies from one individual to another to provide temporary protection against pathogens