Intestinal defence in the young pig--a review of the secretory antibody systems and their possible role in oral immunisation
Porter, P.
Veterinary Record 92(25): 658-664
1973
ISSN/ISBN: 0042-4900 PMID: 4581321 Document Number: 58373
IgA antibodies probably provide an important barrier in the mucosal epithelium, providing a first line of defence against pathogens. IgA is the predominant immunoglobulin in secretions of the mammary gland, salivary gland, gastrointestinal, respiratory and genito-urinary tracts. At some point in its transport to the external surface, IgA is complexed with an additional chain 'secretory component' which is synthesised separately and independently in the epithelial cells. The biological function of this appears to be the protection of the Ig against enzyme degradation and to bind Ig in the surface mucous. Deficiencies in this Ig system may be important in the pathogenesis of infectious disease in the new-born animal and throughout life. The responses of secretory antibody systems involved in defence of the alimentary tract against enteropathogenic Escherichia coli were investigated. Oral vaccines against E. coli enhance the natural developing local defence mechanisms in the alimentary tract of the young animal, so that it can cope more effectively with bacterial challenge after weaning.