Functions of Immunoglobulins

Immunoglobulins (Ig), also known as antibodies, are proteins produced by B cells of the immune system and play a critical role in the body’s immune defense. The primary functions of immunoglobulins include: recognizing and neutralizing foreign pathogens such as bacteria, viruses, and fungi; activating other components of the immune system, including macrophages and natural killer (NK) cells; facilitating pathogen clearance through agglutination or toxin neutralization; and “remembering” pathogens to enable a rapid response upon re-exposure. There are several distinct classes of immunoglobulins—namely IgG, IgA, IgM, IgD, and IgE—each playing unique roles in immune responses. For example, IgG is the most abundant immunoglobulin and can cross the placenta, providing passive immunity to newborns; IgA is predominantly found on mucosal surfaces and constitutes a key component of mucosal immunity. The production and function of immunoglobulins are essential for maintaining human health and resisting disease.