Background

An effective stimulation of the adaptive immune system is based on the activation of T lymphocytes and on their recognition of pathogen-derived peptides presented by MHC-molecules to the respective T-cell receptors (TcR). The high degree of polymorphism of the porcine MHC, which codes for the swine leukocyte antigens (SLA), is expected to expand the panel of antigenic peptides that can be bound and presented, thus influencing disease resistance and vaccine responsiveness.

Due to the extensive polymorphic nature of SLA genes, accurate and sensitive typing methods are important for investigating their distribution in purebred resource populations as well as outbred pigs with diverse genetic backgrounds. The application of a novel developed low-resolution (Lr) DNA-based typing method using the PCR-sequence-specific primer (PCR-SSP) strategy allows high-throughput screening of large numbers of animals at three classical SLA class I (SLA-1, SLA-2, and SLA-3) and class II (DRB1, DQB1, and DQA) loci.

The availability of SLA-defined purebred as well as outbred commercial pig populations with known MHC-background will lead to a better understanding of the adaptive immune response and furthermore facilitate the development and design of more effective vaccines in the context of SLA specificities.

Stated hypotheses

• Particular MHC-haplotypes are susceptible to specific antigens/pathogens.
• Swine production units with recurrent infections exhibit MHC haplotype diversity loss due to unfavourable breeding strategies for disease resistance.
• The outbreak of epizootic diseases and reduced MHC haplotype diversity are positively correlated.

Specific aims

• To survey purebred breeding stocks and commercial pig herds for their MHC haplotype repertoire using a PCR-SSP-based typing approach.
• A better understanding of the MHC-gene composition is an initial step for the design of more effective vaccines and improvement of pig health.