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Diversity of Non-human Glycan Antigen Expression

in Porcine as Xenograft Model

1,2
Ji Eun Park , Myung Jin Oh 1,2 , and Hyun Joo An 1,2*

1 Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon, 34134, Korea

2 Asia-pacific Glycomics Reference Site, Daejeon, 34134, Korea

Overview

Xenotransplantation is a solution to bridge the gap between patients with severe

organ failures and donors, but differences in glycosylation between humans and

pig act as an immune barrier. Representative non-human glycan moieties such as

galactose-α1,3-galactose(α-gal), NeuGc, and SDa antigens act as epitopes

triggering antibody-mediated rejection. Interestingly, unlike other transferases of

non-human antigen expressed only in pig, SDa antigen can be found in both

porcine and humans. Therefore, a structural approach is needed to define the

xenoantigen characteristics.
Xeno-glycan antigen

Distribution of N-glycan

& Diverse α-gal epitope-containing glycans in porcine PBMCs

Materials & Method

We performed glycan profiling and structural analysis of non-human moieties in

porcine endothelial cells and serum, peripheral blood mononuclear cells(PBMCs).

Workflow

NeuAc-sialylated glycans were observed in serum and cells as major components. In

particular, non-human glycans were present in an amount less than 10%. NeuGc-

sialylated glycan portions in cell and serum are around respectively 7% and 3%,

Result & Discussion whereas it was major components in PBMCs. Interestingly, unique glycosylation of

sialic acid attached to antennal N-acetyl glucosamine was determined in cells, and
Structures of numerous α-gal epitope-containing glycans were identified by

glycans expressing both SDa antigen and α-gal epitope were identified in PBMCs.

tandem MS and enzymatic digestion using α-galactosidase, which cleaves gal α1-3

linkages at the terminal. Non-gal antigen is identified by analyzing the Summary

characteristics fragment ions of xeno-glycan antigen in MS/MS spectrum. • The structures of representative glycan antigens that induce immunogenicity were

Identification of non-human glycans determined at the isomeric level using accurate mass, retention time, LC/MS/MS,

by retention times & LC/MS/MS & exoglycosidase and glycan sequencing.

• Our structural profiling data of non-human glycans will be a valuable reference for

immune response studies based on various structural features of xeno-glycan

antigens in mammals.

Acknowledgement

• This work was supported by the Commercialization Promotion Agency for R&D

Outcomes of Korea Grant funded by the Korean Government(MSIP) (2021, R&D

Equipment Engineer Education Program, 2014R1A6A9064166) and Ministry of

Food and Drug Safety in 2022(21172MFDS192-1).

• We thank Optipharm co. ltd. and LABMS members (Laboratory for Advanced Bio-

analytical Mass Spectrometry) for their tremendous help.

GLYCAN SYMBOL

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