Immunogenicity evaluation of GGTA1/B4GalNT2/CMAH knockout pig cartilage tissue in Gal antigen-deficient mice

Objective To compare the immune responses induced by GGTA1/B4 GalNT2/CMAH knockout pig cartilage tissue versus wild-type pig cartilage tissue in Gal antigen-deficient mice. Methods The GGTA1/B4 GalNT2/CMAH gene-knockout pig cartilage tissue(KO)or wild type pig cartilage tissue(WT)was implanted subcutaneously into GGTA1 knockout mice for 4 weeks,respectively.And sham operation group(con)was set as negative control.After 4 weeks,mice serum was taken to detect total IgM antibody and anti-Gal antibody. Results The total IgM content of mice in the WT group was 0.525±0.224 mg/ml,significantly higher than that in the con group(0.121±0.050 mg/ml,P<0.05),but had no difference with KO group(0.313±0.061 mg/ml,P>0.05).Anti-α-Gal IgM level was significantly higher in WT group than KO group and control group(P<0.05,respectively),while no significant difference was found between KO and control group(P>0.05). Conclusion The results indicate that GGTA1/B4 GalNT2/CMAH gene-knockout pig cartilage tissue induces little immune response in vivo and can be used as cartilage defect repairing materials.