Which antibody type is responsible for mucosal immunity?

The antibody type responsible for mucosal immunity is IgA. This immunoglobulin is predominantly found in mucous membranes, including those lining the respiratory and gastrointestinal tracts, as well as in secretions such as saliva, tears, and breast milk. IgA plays a crucial role in defending these surfaces against pathogens, preventing them from adhering to and penetrating epithelial cells.

IgA's unique dimeric structure allows it to be effective at neutralizing viruses and pathogens at mucosal surfaces, creating a first line of defense in the body. Its ability to withstand degradation by proteolytic enzymes further enhances its effectiveness in mucosal areas, where it encounters a variety of environmental microorganisms.

While other immunoglobulins like IgE, IgD, and IgM have important functions in the immune response, they are not primarily associated with mucosal immunity. IgE is involved in allergic responses and protection against parasitic infections, IgD plays a role in B cell activation and signaling, and IgM is typically associated with the initial immune response to infections.