Title: Antigenicity of tissues and organs from GGTA1/CMAH/b4GalNT2 triple gene knockout pigs

 

Authors: Rong-gen Wang1, , Miao-miao Ruan1, , Run-jie Zhang1, Lei Chen1, Xiao-xue Li1, Bin Fang1, Chu Li1, Xue-yang Ren1, Ji-ying Liu1, Qiang Xiong1, Li-ning Zhang1, Yong Jin1, Lin Li1,2, Rong-feng Li1,2, Ying Wang1,2, Hai-yuan Yang1,2, Yi-fan Dai1,2,3,4

 

Institutions: 1Jiangsu Key Laboratory of Xenotransplantation; 2Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center for Cardiovascular Disease Translational Medicine; 3State 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 b4GalNT2) 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 were 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/b4GalNT2, antigenicity

 

Full Text: JBR-2018-0018 pre-proof.pdf

 

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