Exploration of complement-dependent cytotoxicity technology for GTKO/hCD55 genetically engineered pig-to-human xenotransplantation
10.3760/cma.j.cn421203-20220505-00096
- VernacularTitle:GTKO/hCD55基因工程猪到人异种移植CDC技术的探讨
- Author:
Qiangbing XIA
1
;
Hao FENG
;
Lu WANG
;
Song CHEN
;
Lan ZHU
;
Gang CHEN
Author Information
1. 华中科技大学同济医学院附属同济医院器官移植研究所 教育部器官移植重点实验室 国家卫生健康委员会器官移植重点实验室 中国医学科学院器官移植重点实验室，武汉 430030
- Keywords:
Xenotransplantation;
Transgene;
Complement-dependent cytotoxicity
- From:
Chinese Journal of Organ Transplantation
2022;43(6):364-369
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To compare the inhibitory effect of human CD55(hCD55)expressed on porcine peripheral blood mononuclear cells(PBMC)on rabbit complement-and human complement-dependent cytotoxicity(CDC).Methods:Three α1, 3-galactosyltransferase gene knockout(GTKO)pigs from the same strain were selected.Two were transferred with hCD55 gene.According to the expression level of hCD55, the animals were divided into three groups of GTKO, GTKO/hCD55 Low(low-expression of hCD55)and GTKO/hCD55 High(high-expression of hCD55). After PBMC from these pigs were incubated with complement-inactivated pooled human serum(20 cases), rabbit complement-or human complement-dependent cytotoxicity and binding of antibodies(IgM/G)to pig PBMC were detected by flow cytometry. Results:No significant difference existed in binding of human serum xenoreactive antibodies to PBMC from three groups.The cytotoxicity to GTKO pig PBMC mediated by rabbit complement or human complement were 98.97%±0.50% and 82.73%±3.20% respectively.Both values were quite high.Compared with GTKO group, a low expression of hCD55 had no significant inhibitory effect on rabbit complement-dependent cytotoxicity(97.07%±2.25% vs. 98.9%±0.50%, P=0.2 267) while a high expression of hCD55 exerted a mild inhibitory effect on rabbit complement-dependent cytotoxicity(81.70%±5.86% vs. 98.9%±0.50%, P=0.0 355). Differently, a low expression of hCD55 had a potent inhibitory effect on human complement-dependent cytotoxicity(23.83%±3.53% vs. 82.73%±3.20%, P<0.0 001). Compared with hCD55 low-expression group, a high expression of hCD55 had a further inhibitory effect on human complement-dependent cytotoxicity(2.79%±0.45% vs. 82.73%±3.20%, P=0.009), attaining the level of negative control group.The inhibitory effect of low/high expression of hCD55 on human complement-mediated CDC was significantly better than that on rabbit complement-mediated CDC. Conclusions:Compared with traditional CDC counterpart using rabbit complement, modified CDC technology of commercial standard human complement is recommended for evaluating the regulatory effect of hCD55 expressed on cell surface from GTKO/hCD55 genetically engineered pigs.It thus provides experimental rationales for establishing a novel CDC experimental system of effectively evaluate the function of hCD55 after xenotransplantation.
