Title: Antigenicity of tissues and organs from GGTA1/CMAH/β4GalNT2 triple gene knockout pigs

 

Authors: Ronggen Wang1, Miaomiao Ruan1, Runjie Zhang1, Lei Chen1, Xiaoxue Li 1, Bin Fang1, Chu Li1, Xueyang Ren1, Jiying Liu1, Qiang Xiong1, Lining Zhang1, Yong Jin1, Lin Li1,2, Rongfeng Li1,2, Ying Wang1,2, Haiyuan Yang1,2, Yifan Dai 1,2,3,4

 

Institutions: 1Jiangsu Key Laboratory of Xenotransplantation, 2 Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, 3 State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, Jiangsu 211166, China; 4Shenzhen Xenotransplantation Medical Engineering Research and Development Center, Institute of Translational Medicine, Shenzhen Second Peoples Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong 518035, China.

 

Abstract: Clinical xenotransplantations have been hampered by human preformed antibody-mediated damage of the xenografts. To overcome biological incompatibility between pigs and humans, one strategy is to remove the major antigens [Gal, Neu5Gc, and Sd(a)] present on pig cells and tissues. Triple gene (GGTA1, CMAH, and β4GalNT2) knockout (TKO) pigs were produced in our laboratory by CRISPR-Cas9 targeting. To investigate the antigenicity reduction in the TKO pigs, the expression levels of these three xenoantigens in the cornea, heart, liver, spleen, lung, kidney, and pancreas tissues were examined. The level of human IgG/IgM binding to those tissues was also investigated, with wildtype pig tissues as control. The results showed that αGal, Neu5Gc, and Sd(a) were markedly positive in all the examined tissues in wildtype pigs but barely detected in TKO pigs. Compared to wildtype pigs, the liver, spleen, and pancreas of TKO pigs showed comparable levels of human IgG and IgM binding, whereas corneas, heart, lung, and kidney of TKO pigs exhibited significantly reduced human IgG and IgM binding. These results indicate that the antigenicity of TKO pig is significantly reduced and the remaining xenoantigens on porcine tissues can be eliminated via a gene targeting approach.

 

Keywords: pig, xenotransplantation, GGTA1, CMAH, β4GalNT2, antigenicity

 

Full Text: JBR-2018-0018.pdf

 

J Biomed Res published on 31 May 2018, https://doi.org/10.7555/JBR.32.20180018