Immuno-Epigenetics: A Veterinarian's Perspective on Reducing the Use of Antimicrobials through the Use of Nutritional Immunology

摘要

Reducing the use of antimicrobials in the rearing of poultry can be achieved by enhancing the natural immunity of chickens, thus minimizing disease and pathogen shedding. Intervention of the immune system of the chick in ovo has a dramatic effect on the immunity of the bird post-hatch, increasing its ability to resist a disease challenge. However, it is not only the chick's immune system that must be strengthened but also that of the adult bird. The nutritional status of the laying hen directly influences the nutrient composition of the egg and, in turn, the development and nutritional status of the embryo and hatchling. This has implications for epigenetic regulation of gene expression allowing dividing cells to memorize, or imprint, signalling events that occurred earlier in their development. Folic acid (FA), also known as folate, plays a critical role in nucleic acid and protein synthesis; a deficiency of folate significantly alters the immune response. The body utilizes FA as a methyl group donor that can be incorporated into the DNA and potentially affect gene expression. Toll like receptors (TLR) and the B cell receptor (BCR) recognize antigens, and the major histocompatibility complex (MHC) is used to present the antigen to T cells to initiate an adaptive immune response. Taken together our preliminary results it is possible to infer that FA has an immunomodulatory effect on chicken B cells, possibly affecting their ability to both recognize antigen through the TLR and BCR pathways and their ability to present antigen via the MHCII presentation pathway.