无特定病原体（SPF）猪是国际公认的标准化高等级农用实验动物，而疫病易感型SPF猪是重要的畜禽疫病防控用模式动物，但我国一直缺乏疫病易感猪群，实验用猪多从养猪企业中筛选，遗传背景、微生物的杂乱与我国的强制免疫政策使筛选易感猪十分困难。猪白细胞抗原（SLA）包含许多免疫相关基因，具有高度的多态性，使SLA单倍型具有复杂的多样性，不同SLA单倍型猪感染病原后可产生不同的免疫应答，具有疫病易感性差异，因此本研究通过体外和体内动物感染实验，明确不同SLA单倍型猪群对猪繁殖与呼吸综合征病毒（PRRSV）的易感性差异，组建SLA单倍型易感型猪群，对其进行质量控制和标准化研究，且通过分析SLA区域I类和II类基因的核苷酸突变、等位基因转换，同源重组和遗传进化过程等特征，探究SLA单倍型猪群出现易感性差异的分子遗传机制，为科技创新、重大疫病防控、生物制品生产检验提供有力的条件支撑。

Specific pathogen-free (SPF) pig is internationally recognized standardized high grade agricultural experimental animals. The susceptible SPF pig is an important model animal for livestock and poultry disease prevention and control. However, the disease susceptible pigs have been lacking in our country. The experimental pigs are mostly screened from pig breeding enterprises. The chaos of genetic background and microorganism and China's compulsory immunization policy make it difficult to screen susceptible pigs. Swine leukocyte antigen (SLA) contains many immune related genes and is highly polymorphic. There is the complicated diversity for SLA haplotypes. Moreover, the different immune responses can be induced by pathogene for different SLA haplotype pigs and have different susceptibility. In this study, the susceptibility differences of SLA haplotype pigs to porcine reproductive and respiratory syndrome virus (PRRSV) will be determined by in vitro and in vivo animal infection experiments. The susceptible SLA haplotype pig population(s) will be established and the quality control and standardization will be study. The molecular genetic mechanism of susceptibility differences of SLA haplotype pigs will be explored by analyzing the nucleotide mutation, allelic gene conversions, homologous recombination, and genetic evolution process of SLA class I and II genes. This study may provide strong support for technological innovation, major epidemic prevention and control, and biological products production and inspection.