Ig antibody | Function |
---|---|
IgM | First immunoglobulin (Ig) expressed during B cell development (primary response; early antibody) • Opsonizing (coating) antigen for destruction • Complement fixation |
IgG | Main Ig during secondary immune response • Only antibody capable of crossing the placental barrier • Neutralization of toxins and viruses • Opsonizing (coating) antigen for destruction • Complement fixation |
IgD | Function unclear; appears to be involved in homeostasis |
IgA | Mucosal response; protects mucosal surfaces from toxins, viruses and bacteria through either direct neutralization or prevention of binding to mucosal surface |
IgE | Associated with hypersensitivity and allergic reactions • Plays a role in immune response to parasites |