Immunoglobulin A (IgA): molecular and cellular interactions involved in IgA biosynthesis and immune response.

摘要: Publisher Summary This chapter discusses the impact of new information concerning IgA physiology on immune system. should not be considered only as an isotype providing specific humoral protection mucosal surfaces but integral component entire An unusual structural feature human is heterogeneity molecular forms with characteristic distribution in various body fluids. Though most serum displays a typical four-polypeptide chain structure basic molecule two Q and light (L) chains, external secretions contain dimeric tetrameric, disulfide-linked molecules associated additional polypeptides-J (joining) secretory (SC). IgA-producing plasma cells are distributed lymphoid nonlymphoid tissues particularly preponderant lamina propria gut; salivary, lacrimal, lactating mammary glands; bone marrow. occurs different fluids predominantly polymeric or monomeric (plasma, cerebrospinal fluid) IgAl IgAz molecules. Under normal conditions, absolute majority IgA-containing glands also J whereas such in, for example, marrow does not. Staining fluorochrome-labeled anti-J enhanced by pretreatment alcohol-fixed tissue sections acid urea, which leads to exposure masked antigenic determinants intracellular chain. Specialized play essential role induction regulation generalized responses secretions.