What is the predominant antibody in mucus and saliva tears milk?

The predominant antibody in mucus and saliva is Immunoglobulin A (IgA). IgA is a secretory antibody, which means it is produced by B cells in mucosal tissues and secreted onto mucosal surfaces, such as the lining of the respiratory, digestive, and urogenital tracts. It is also found in tears and milk, providing protection against pathogens that enter the body through these routes.

IgA plays a vital role in mucosal immunity by preventing the attachment of pathogens to mucosal surfaces and by neutralizing toxins. It also activates other immune mechanisms, such as complement activation and phagocytosis, to eliminate pathogens. Additionally, IgA can transport antigens across mucosal epithelial cells, facilitating immune surveillance and the induction of immune responses.