Stimulation of secretory antibody following oral administration of antigen.
IgA antibodies produced by plasma cells in secretory tissues associated with mucosal surfaces represent a major host defense against infectious agents. Precursors of these IgA-producing cells originate in gut-associated lymphoid tissue and, to a lesser extent, in bronchial-associated lymphoid tissue and migrate via the blood not only to gut but also to other mucosal tissues, forming a common mucosal immune system. Oral administration of antigen leads to priming of precursor cells in the gut and subsequent occurrence of specific secretory IgA (S-IgA) antibody in saliva, milk, tears, and the respiratory and genital tracts. On the basis of a review of the world literature, it has been concluded that oral live vaccines elicit higher antibody titers in remote-site secretions and in serum than do oral killed vaccines, which usually stimulate only relatively low levels of local secretory antibody. Oral immunization induces S-IgA in children and adults (including the elderly) without detectable adverse effects. Despite a number of remaining questions, oral immunization against extraintestinal infections is a promising area for future clinical studies.
Bergmann
K C
KC
Department of Allergology, Karl-Hansen-Klinik, Bad Lippspringe, Federal Republic of Germany.
Waldman
R H
RH
D000284:Administration, Oral; D000375:Aging / Q000276:immunology; D000818:Animals; D000941:Antigens / Q000008:administration & dosage / Q000276:immunology*; D000942:Antigens, Bacterial / Q000008:administration & dosage / Q000276:immunology; D000956:Antigens, Viral / Q000008:administration & dosage / Q000276:immunology; D006801:Humans; D007114:Immunization; D007071:Immunoglobulin A, Secretory / Q000096:biosynthesis*
D000941:Antigens; D000942:Antigens, Bacterial; D000956:Antigens, Viral; D007071:Immunoglobulin A, Secretory