Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 9/12/1997
Publication Date: N/A
Technical Abstract: This review summarizes the current knowledge of the major genetic loci which control swine immune responses. The immune system protects swine against infection and coordinates immune responses to an unknown array of foreign antigens. The immune system adds an additional level of complexity to understanding the genetics of swine as a result the evolution of lymphocytes, i.e., the T cells and B cells. Unlike other somatic cells, the lymphocyte utilize a combination of genetic mechanisms to generate a vast repertoire of T-cell receptor (TCR) and B-cell receptor (BCR) phenotypes with which to sample the antigenic environment and stimulate appropriate immune responses of T cells with cytokines and B cells with antibodies. Without the use of such mechanisms, the huge TCR and BCR repertoire would require more DNA than is in the entire typical mammalian genome. An equally important genetic element is the major histocompatibility complex (MHC) which is also highly complex, not due to somatic recombination and mutation events, but rather resulting from the large number of allelic variants at many of the >200 loci in the complex. The MHC antigens are vital to the overall immune response because of their role in binding and presentation of foreign antigens to the TCR. As management changes in the pig industry alter the range of pathogens to which pigs are exposed, and as consumers demand pork products free of antibiotic contamination, it becomes increasingly more important that disease resistant breeding stock be available. Disease resistant pigs, in well- managed facilities, will help decrease drug usage by producers and increase the health of the nation's food supply.