Lamm M E
Institute of Pathology, Case Western Reserve University, Cleveland, Ohio 44106-2622, USA.
Aliment Pharmacol Ther. 1997 Dec;11 Suppl 3:40-4; discussion 44-6. doi: 10.1111/j.1365-2036.1997.tb00807.x.
Exogenous antigens can impinge upon the luminal surface of mucous membranes and to a limited degree, can even penetrate into the lamina propria. As a result of infection, microbial antigens can be present in mucosal epithelium or lamina propria. At all three levels (lumen, epithelium, lamina propria), locally produced antibodies, principally immunoglobulin A (IgA), can combine with antigens. As a result, antigens can be prevented from attaching to the epithelium, viruses can be neutralized inside epithelial cells and immune complexes in the lamina propria can be excreted into the lumen. As the Fc portion of IgA is specialized to facilitate epithelial transport of IgA rather than to activate inflammatory mediator systems (as is the case with other classes of immunoglobulin), the predominance of IgA among mucosal antibodies serves to limit the degree of local inflammation following antigen-antibody reactions.
外源性抗原可作用于黏膜的管腔表面，甚至在一定程度上可穿透至固有层。感染后，微生物抗原可存在于黏膜上皮或固有层。在所有三个层面（管腔、上皮、固有层），局部产生的抗体，主要是免疫球蛋白A（IgA），可与抗原结合。因此，可防止抗原附着于上皮，病毒可在上皮细胞内被中和，固有层中的免疫复合物可排泄至管腔。由于IgA的Fc部分专门用于促进IgA的上皮转运，而不是激活炎症介质系统（其他类别的免疫球蛋白则会激活），IgA在黏膜抗体中的优势有助于限制抗原 - 抗体反应后局部炎症的程度。
