Proteomics Analysis of Aqueous Humor and Rejected Graft in Pig-to-Non-Human Primate Corneal Xenotransplantation

Jae Won Oh; Chang Ho Yoon; Jin Suk Ryu; Kwang Pyo Kim; Mee Kum Kim

doi:10.3389/fimmu.2022.859929

Proteomics Analysis of Aqueous Humor and Rejected Graft in Pig-to-Non-Human Primate Corneal Xenotransplantation

Front Immunol. 2022 Mar 24:13:859929. doi: 10.3389/fimmu.2022.859929. eCollection 2022.

Authors

Jae Won Oh^{1

2}, Chang Ho Yoon^{3

4

5}, Jin Suk Ryu³, Kwang Pyo Kim^{1

2}, Mee Kum Kim^{3

4

5

6}

Affiliations

¹ Department of Applied Chemistry, Institute of Natural Science, Global Center for Pharmaceutical Ingredient Materials, Kyung Hee University, Yongin, South Korea.
² Department of Biomedical Science and Technology, Kyung Hee Medical Science Research Institute, Kyung Hee University, Seoul, South Korea.
³ Laboratory of Ocular Regenerative Medicine and Immunology, Seoul Artificial Eye Center, Seoul National University Hospital Biomedical Research Institute, Seoul, South Korea.
⁴ Department of Ophthalmology, Seoul National University College of Medicine, Seoul, South Korea.
⁵ Department of Ophthalmology, Seoul National University Hospital, Seoul, South Korea.
⁶ Transplantation Research Institute, Seoul National University Medical Research Center, Seoul, South Korea.

Abstract

Although pig-to-non-human primate (NHP) corneal xenotransplantation has shown long-term graft survival, xenogeneic antigen-related immune responses are still stronger than allogeneic antigen-associated responses. Therefore, there is an unmet need to investigate major rejection pathways in corneal xenotransplantation, even with immunosuppression. This study aimed to identify biomarkers in aqueous humor for predicting rejection and to investigate rejection-related pathways in grafts from NHPs transplanted with porcine corneas following the administration of steroids combined with tacrolimus/rituximab. NHPs who had received corneas from wild-type (WT) or α-1,3-galactosyltransferase gene-knockout (GTKO) pigs were divided into groups with or without rejection according to clinical examinations. Liquid chromatography-mass spectrometry (LC-MS) was used to analyze the proteomes of corneal tissues or aqueous humor. The biological functions of differentially expressed proteins (DEPs) were assessed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) for pathways and protein-protein interaction network analysis. Among the 66 DEPs in aqueous humor, complement proteins (C3, C5, and C9) and cholesterol metabolic proteins (APOA1 and APOA2) were related to xenogeneic rejection as biomarkers, and alternative pathways of the complement system seemed to be important in xenogeneic graft rejection. Among the 416 DEPs of the cornea, NF-κB1 and proteosomes (PSMD7, PSMA5, and PSMD3) seemed to be related to xenogeneic graft rejection. Additionally, oxidative phosphorylation and leukocyte activation-related pathways are involved in rejection. Overall, our proteomic approach highlights the important role of NF-κB1, proteosomes, oxidative phosphorylation, and leukocyte activation-related inflammation in the cornea and the relevance of complement pathways of the aqueous humor as a predictive biomarker of xenogeneic rejection.

Keywords: aqueous humor; cornea; non-human primate (macaque); pig; proteomics; rejection; xenotransplantation.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Aqueous Humor
Biomarkers
Complement System Proteins
Cornea
Corneal Transplantation* / methods
Graft Survival
Primates
Proteomics
Swine
Transplantation, Heterologous / methods

Substances

Biomarkers
Complement System Proteins