Concept of the Local and Common Mucosal Immune Response

A major problem that has received considerable attention concerns a method for effectively stimulating a selective IgA-associ-ated immune response on mucous surfaces. Earlier immunization attempts indicated that an antigen applied to the mucous membrane penetrates these membranes and encounters B-lymphocytes that have the potential of differentiating into IgA-producing plasma cells of a given specificity. The IgA produced is then actively transported through epithelial cells on the surface of the membrane where the original antigen stimulation occurred. Numerous examples clearly demonstrate the efficiency of this pathway of immunization. For example, the stimulation through the conjunctival sac of one eye led to the appearance of antibodies in tears from the immunized site but not in secretions from the other eye (1). Similarly, the application of viral antigen into the large intestine of individuals who have had double-barrelled colostomies induced s-IgA antibodies restricted to the site of antigen application but failed to induce antibodies in other parts of the intestine, in glandular secretions or in nasal secretions (2). These are only two examples of experiments that are suggestive of an IgA-associated immune response that results from topical antigen application.