Submitted to: Developmental and Comparative Immunology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/23/2008
Publication Date: 8/27/2008
Citation: Lunney, J.K., Ho, C., Wysocki, M., Smith, D.M. 2008. Molecular genetics of the swine major histocompatibility complex, the SLA complex. Developmental and Comparative Immunology. 33(3):362-374.
Interpretive Summary: There are many genetic loci which control swine immune, disease and vaccine responses. The most important of these is the major histocompatibility complex (MHC), in swine, the swine leukocyte antigen (SLA) complex. To understand why pigs have different responses researchers must have knowledge of the genes that map to this complex and their heterogeneity in swine, methods to distinguish alleles at each important locus and data on the impact of these genes on immune, disease and vaccine responses. This review presents a review of these areas for the SLA complex genes. With this data researchers will be better able to characterize the genomes of their pigs and the allelic heterogeneity of SLA genes. In addition, all SLA sequence data is posted on the Immuno Polymorphism Database-MHC (IPD-MHC) website (http://www.ebi.ac.uk/ipd/mhc/sla/) which serves as the repository for maintaining a list of all SLA recognized genes and their allelic sequences. Researchers will be able to determine how to assign SLA haplotypes, sets of SLA gene alleles, that are shared within families of pigs due to the high linkage disequilibrium (lack of genetic recombination) in mammalian MHCs. The review summarizes data from labs worldwide on the expression of SLA proteins on cell subsets and the role of individual SLA proteins in antigen presentation and their potential for regulating immune responses. The final part discusses the role of SLA genes in swine production traits and responses to infectious disease and vaccines and relevance for swine models of transplantation, enotransplantation, cancer and allergy.
Technical Abstract: The swine major histocompatibility complex (MHC) or swine leukocyte antigen (SLA) complex is one of the most gene-dense regions in the swine genome. It consists of three major gene clusters, the SLA class I, class III and class II regions, that span ~1.1, 0.7 and 0.5 Mb, respectively, making the swine MHC the smallest among mammalian MHC so far examined and the only one known to span the centromere. This review summarizes recent updates to the Immuno Polymorphism Database-MHC (IPD-MHC) website (http://www.ebi.ac.uk/ipd/mhc/sla/) which serves as the repository for maintaining a list of all SLA recognized genes and their allelic sequences. It reviews the expression of SLA proteins on cell subsets and their role in antigen presentation and regulating immune responses. It concludes by discussing the role of SLA genes in swine models of transplantation, xenotransplantation, cancer and allergy and in swine production traits and responses to infectious disease and vaccines.