New alleles of SLA-DQB isolated from miniature pigs

Characterization of swine leukocyte antigen (SLA) polymorphism by sequence-based and PCR-SSP methods in Chinese Bama miniature pigs

The highly polymorphic swine leukocyte antigen (SLA) genes have been repeatedly shown to influence swine immune traits, disease resistance, vaccine responsiveness and tumour penetrance. Analysis of the SLA diversity in as many pig breeds as possible is important to clarify the relationships between SLA genes and diseases or traits, and develop these pigs as valuable animal models for biomedical research. The Chinese Bama miniature pig breed is an economically significant breed that is available at several research institutions in China. In this study, we identified a total of 32 alleles at five polymorphic SLA loci (SLA-1, SLA-3, SLA-2, DRB1 and DQB1) representing nine class I and seven class II haplotypes using the reverse transcription polymerase chain reaction (RT-PCR) sequence-based typing (SBT) method. The possible functional sites of the SLA genes were predicted and analyzed by comparison with those of the human and mouse. Based on the sequence information, we subsequently developed a rapid PCR-based typing assay using sequence-specific primers (PCR-SSP) to efficiently follow the SLA types of the progeny. In the studied cohort (2n = 562), the most prevalent Haplotype Hp-35.6 (SLA-1(∗)1201, SLA-1(∗)1301-SLA-3(∗)0502-SLA-2(∗)1001-DRB1(∗)0501-DQB1(∗)0801) was identified in 182 Bama pigs with a frequency of 32.38%. The presence of the duplicated SLA-1 locus was confirmed in five of the class I haplotypes. Moreover, we identified two crossovers within the class I region and one between the class I and class II regions, which corresponded to recombination frequencies of 0.36% and 0.18%, respectively. The information of this study is essential for an understanding of the SLA allelic architecture and diversity, and it will be helpful for studying the adaptive immune response and further developing the more effective vaccines in the context of SLA specificities.

Nomenclature for factors of the swine leukocyte antigen class II system, 2005

A systematic nomenclature for the genes and alleles of the swine major histocompatibility complex (MHC) is essential to the development and communication of research in swine immunology. The Swine Leukocyte Antigen (SLA) Nomenclature Committee of the International Society for Animal Genetics (ISAG) has reviewed all of the DNA-sequence information for MHC class II genes, available in GenBank/EMBL/DDBJ databases, and the associated published reports to develop such a systematic nomenclature. This article summarizes the proposed nomenclature, which parallels the World Health Organization's nomenclature for factors of the human MHC. The SLA class II genes expressed on the cell membrane will be noted as SLA-DRA, SLA-DRB1, SLA-DQA, and SLA-DQB1. Nomenclature assignments for all SLA class II GenBank sequences are now noted. The committee will add new SLA class II allele designations, as they are discovered, and will maintain a publicly available list of all recognized genes and alleles using the Immuno Polymorphism Database (IPD). The sequences will be available from the IPD-MHC section of the database which contains non-human MHC sequences (http://www.ebi.ac.uk/ipd/mhc/sla/).

Rapid assignment of the swine major histocompatibility complex (SLA) class I and II genotypes in Clawn miniature swine using PCR-SSP and PCR-RFLP methods

BACKGROUND

Inbred miniature swine with defined novel SLA haplotypes will be useful in allo- and xeno-transplantation studies, which can be carried out representing variable combinations of SLA haplotypes.

METHODS

In Clawn miniature swine, two haplotypes (c1 and c2) and one crossover haplotype (c3) have been assigned by nucleotide sequence determination of RT-PCR products of the three SLA classical class I genes and two SLA class II genes. To select SLA class I and II homozygotes in Clawn miniature swine individuals, we developed a rapid and simple SLA-class I- and II-DNA typing method by a combination of polymerase chain reaction-sequence specific primer (PCR-SSP) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) techniques.

RESULTS

Seven allele specific primer pairs were designed for amplification of the second exons of three SLA class I genes, SLA-1, SLA-2, and SLA-3, and one SLA class II gene, DRB1. Furthermore, based on PCR-RFLP patterns in the SLA-DQB1 gene, two allelic variants were recognized in the second exon in the Clawn miniature swine. Three haplotypes, c1, c2 and c3, were simply identified by the combination of PCR-SSP and PCR-RFLP methods in 22 samples from five families. A single allele at each of the class I and II genes was also observed in seven samples as SLA class I and II homozygotes with either the c1 or c2 haplotype.

CONCLUSIONS

The combination of PCR-SSP and PCR-RFLP methods facilitate the rapid identification of the three haplotypes and SLA class I and II homozygotes in individual Clawn miniature swine.

Use of the Gottingen Minipig as a Model of Diabetes, with Special Focus on Type 1 Diabetes Research

Animal models of type 1 diabetes remain essential tools for investigation of the etiology and pathogenesis of the disease and, importantly, for the development of effective new treatments. Although a range of well-characterized and widely used models of type 1 diabetes in rodents are currently available, large animal models are a valuable complement to rodent models for both physiological and practical reasons. The pig is very useful in many aspects as a model for human physiology and pathophysiology because many organ systems of this species, as well as physiological and pathophysiological responses, resemble those of the human. The Göttingen minipig is particularly suitable for long-term studies because of its inherent small size and ease of handling, even at full maturity. Of particular relevance to the field of type 1 diabetes are the many similarities evident between humans and pigs with regard to pharmacokinetics of compounds after subcutaneous administration, structure and function of the gastrointestinal tract, morphology of the pancreas, and the overall metabolic status of the two species. Because spontaneous type 1-like diabetes is very rare in pigs, a model of the condition must be induced experimentally, either surgically or chemically. This process is discussed, and the use of the pig as a model in islet transplantation and diabetic complications is briefly summarized.