Immunotherapeutic Potential of Antibodies Produced in Chicken Eggs

Abstract

Oral administration of specific antibodies is an attractive approach to establish passive immunity against gastrointestinal pathogens in human and animals. Recently, laying hens have attracted considerable attention as an alternative source of antibody for peroral immunotherapy. After immunization of the chicken, the specific antibodies (called IgY) are transported to the egg yolk from which the IgY then can be separated without sacrificing chickens. Egg yolk contains 70–250 mg of IgY per yolk, suggesting that more than 30g of IgY can be obtained per year. Eggs are also normal dietary components and mass production systems in chicken farms are already established. Thus, IgY is considered to be more hygienic and economical source of antibodies than antibodies from mammalian sera. Oral administration of IgY has proven to be successful for treatment of a variety of gastrointestinal infections. The passive immunization of IgY has been applied to the prevention of human rotavirus infections. A successful trial of passive immunization of rainbow trout against infection with Y. ruckeri has been achieved with specific IgY. Enterotoxigenic Escherichia coli (ETEC) is the major cause of diarrhea and death in neonatal calves and piglets. Anti-ETEC IgY was found to be effective in controlling diarrhea of new-born calves and piglets. Salmonella spp are also often pathogenic to human and animals. Anti-Salmonella IgY can provide a prophylactic function to prevent Salmonellosis in animals. Other applications for immunotherapeutic potential of IgY also have been documented in this chapter. IgY technology may provide great opportunities for designing prophylactic strategies against infectious gastrointestinal diseases in humans and animals.