【Animal modeling】-GGTA1-/- Wuzhishan miniature pig SLA class I gene molecular characteristics and similarity analysis with HLA

  Objective: To clarify the molecular structure of SLA class I gene of Wuzhishan miniature pig with α-1,3 galactosyltransferase gene knockout (GGTA1-/-) and its similarity with human HLA, and to study the cellularity of xenotransplantation. Rejection is important.

  Methods: The ear tissues of 6 ancestral GGTA1-/- Wuzhishan miniature pigs were collected, and SLA class I genes (SLA-1, SLA-3, SLA-2) were amplified, cloned and sequenced by RT-PCR, and the sequences were BLASTed. The molecular structure of SLA class I gene and its homology with human HLA were analyzed by bioinformatics method.

  Results: Sequencing analysis showed that a total of 6 allele sequences were obtained, of which 4 were published alleles (SLA-1*0703, SLA-2*1102, SLA-3*0401, SLA-3*0403) , and the other two are new alleles (SLA-1*0401wz01, SLA-2*11wz01). The HLA homology between Wuzhishan miniature pigs and human was 70.5%-72.1%. The key binding domains of CD8+ molecular recognition of SLA-1*0401wz01, SLA-1*0703, SLA-2*11wz01, SLA-2*1102 and SLA-3*0401 were aligned with human HLA amino acid sequences, all of which were only at the site Mutations occurred at 225 and 228 (T→S, T→M), and other sites were highly conserved. SLA-2*11wz01 and SLA-2*1102 have high amino acid homology with the binding domain of human HLA class I gene NK cell inhibitory receptor (KIR), and only 1 in the binding domain of NKTA-1 subtype 1 amino acid difference, and 2 amino acid differences within the NKTA-2 and NKTA-3 subtype binding domains.

  Conclusion: From the perspective of immune cell-mediated xenogeneic rejection, the amino acid sequence of SLA class I gene of GGTA1-/- Wuzhishan miniature pig is highly similar to human HLA, which can be used as one of the good donors for future pig-human xenotransplantation.