Medical School of Chinese PLA & Medical Laboratory Center, First Medical Center of Chinese PLA General Hospital, Beijing 100853, China.
Institute for Medical Device Control, National Institutes for Food and Drug Control, Beijing 102629, China.
Biomed Res Int. 2020 Jun 3;2020:9680474. doi: 10.1155/2020/9680474. eCollection 2020.
Animal tissues and tissue-derived biomaterials are widely used in the field of xenotransplantation and regenerative medicine. A potential immunogenic risk that affects the safety and effectiveness of xenografts is the presence of remnant -Gal antigen (synthesized by or/and ). knockout mice have been developed as a suitable model for the analysis of anti-Gal antibody-mediated immunogenicity. However, we are yet to establish whether double knockout (G/i DKO) mice are sensitive to Gal antigen-positive xenoimplants.
-Gal antigen expression in the main organs of G/i DKO mice or bovine bone substitutes was detected via a standardized ELISA inhibition assay. Serum anti--Gal antibody titers of G/i DKO mice after immunization with rabbit red blood cells (RRBC) and implantation of raw lyophilized bone substitutes (Gal antigen content was 8.14 ± 3.17 × 10/mg) or Guanhao Biotech bone substitutes (50% decrease in Gal antigen relative to the raw material) were assessed. The evaluation of total serum antibody, inflammatory cytokine, and splenic lymphocyte subtype populations and the histological analysis of implants and thymus were performed to systematically assess the immune response caused by bovine bone substitutes and bone substitute grafts in DKO mice.
-Gal epitope expression was reduced by 100% in the main organs of G/i DKO mice, compared with their wild-type counterparts. Following immunization with RRBC, serum anti-Gal antibody titers of G/i DKO mice increased from 80- to 180-fold. After subcutaneous implantation of raw lyophilized bone substitutes and Guanhao Biotech bone substitutes into G/i DKO mice, specific anti--Gal IgG, anti--Gal IgM, and related inflammatory factors (IFN- and IL-6) were significantly increased in the raw lyophilized bone substitute group but showed limited changes in the Guanhao Biotech bone substitute group, compared with the control.
G/i DKO mice are sensitive to Gal antigen-positive xenogeneic grafts and can be effectively utilized for evaluating the -Gal-mediated immunogenic risk of xenogeneic grafts.
动物组织和组织衍生的生物材料广泛应用于异种移植和再生医学领域。影响异种移植物安全性和有效性的一个潜在免疫原性风险是残余 -Gal 抗原的存在（由 或/和 合成）。已经开发出 -Gal 敲除小鼠作为分析抗 -Gal 抗体介导的免疫原性的合适模型。然而，我们还需要确定 -Gal 双敲除（G/i DKO）小鼠是否对 Gal 抗原阳性的异种移植物敏感。
通过标准化 ELISA 抑制试验检测 G/i DKO 小鼠主要器官或牛骨替代物中的 -Gal 抗原表达。用兔红细胞（RRBC）免疫和植入未经处理的冻干骨替代物（Gal 抗原含量为 8.14±3.17×10/mg）或 Guanhao Biotech 骨替代物（相对于原料减少 50%的 Gal 抗原）后，检测 G/i DKO 小鼠的血清抗 -Gal 抗体滴度。系统评估牛骨替代物和骨替代物移植物在 G/i DKO 小鼠中引起的总血清抗体、炎症细胞因子和脾淋巴细胞亚型群体，并进行植入物和胸腺的组织学分析。
与野生型相比，G/i DKO 小鼠的主要器官中 -Gal 表位表达降低了 100%。用 RRBC 免疫后，G/i DKO 小鼠的血清抗 -Gal 抗体滴度增加了 80-180 倍。将未经处理的冻干骨替代物和 Guanhao Biotech 骨替代物皮下植入 G/i DKO 小鼠后，与对照组相比，未经处理的冻干骨替代物组中特异性抗 -Gal IgG、抗 -Gal IgM 和相关炎症因子（IFN-和 IL-6）显著增加，但 Guanhao Biotech 骨替代物组变化有限。
G/i DKO 小鼠对 Gal 抗原阳性的异种移植物敏感，可有效用于评估异种移植物的 -Gal 介导的免疫原性风险。
