Can be involved in noninflammatory or proinflammatory activities.
Most prominent antibody class present in mucosa.
2 subclasses-IgA1 and IgA2.
Present in mucosal secretions, secretory IgA (SIgA) consists of a dimeric IgA molecule, J chain and secretory component.
Secretory IgA poorly opsonized due to blockage of receptor binding site by secretory component precluding activation of immune cells.
Serum IgA promotes opsonization of bacteria by FCαR1 expressing phagocytes.