Sla, which stands for Swine leukocyte antigen, encodes multi-glycoproteins on cell surface. Sla class I molecules present endogenous antigenic peptides to T cells, initiating specific immune responses. Sla genes are involved in the body's immune-related pathways and are of great importance for the pig's immune system [3].

Targeted knockout of SLA-DMA or SLA-DMB genes in porcine cells led to severe replication defects of different African swine fever virus (ASFV) isolates, reflected by reduced plating efficiency, cell-to-cell spread, progeny virus titers and viral DNA replication. Transgene-based reconstitution of SLA-DMA/B fully restored the replication capacity, demonstrating that SLA-DM plays a crucial role during early steps of ASFV infection [1]. Also, SLA class I molecule-restricted T-cell epitopes play a critical role in the clearance of porcine reproductive and respiratory syndrome virus (PRRSV) [2].

In conclusion, Sla genes are essential for the pig's immune response. Gene knockout studies in porcine cells have revealed their crucial role in the replication of ASFV and the clearance of PRRSV, providing insights into the mechanisms of virus-host interactions and potential strategies for developing vaccines against swine diseases.

References:

1. Pannhorst, Katrin, Carlson, Jolene, Hölper, Julia E, Fuchs, Walter, Mettenleiter, Thomas C. 2023. The non-classical major histocompatibility complex II protein SLA-DM is crucial for African swine fever virus replication. In Scientific reports, 13, 10342. doi:10.1038/s41598-023-36788-9. https://pubmed.ncbi.nlm.nih.gov/37604847/

2. Luo, Tingyu, Xin, Chang, Liu, Hongyi, Xia, Changyou, Gao, Caixia. 2024. Potential SLA Hp-4.0 haplotype-restricted CTL epitopes identified from the membrane protein of PRRSV induce cell immune responses. In Frontiers in microbiology, 15, 1404558. doi:10.3389/fmicb.2024.1404558. https://pubmed.ncbi.nlm.nih.gov/38841061/

3. Tao, Xuan, Li, Hua, Li, Xue-Wei, Yu, Hui, Zuo, Qi-Zhen. . [Latest advances of SLA class I genes]. In Yi chuan = Hereditas, 29, 1309-16. doi:. https://pubmed.ncbi.nlm.nih.gov/17989038/