Lectin array analysis for wild-type and α-Gal-knockout pig islets versus healthy human islets

Area of Science:

• Glycobiology
• Transplantation immunology
• Xenotransplantation research

Background:

• Understanding islet cell surface glycans is crucial for xenotransplantation compatibility.
• Pig islets are a potential source for human transplantation, but immunological barriers exist.
• Lectin microarray analysis provides a high-throughput method for glycan profiling.

Purpose of the Study:

• To analyze and compare glycan profiles of wild-type (WT) pig islets, α1-3galactosyltransferase gene knockout (GKO) pig islets, and human islets using lectin microarray.
• To investigate the impact of GKO on specific glycan structures in pig islets.
• To identify differences in glycan expression between porcine and human islets.

Main Methods:

• Islet isolation from pig and human pancreas.
• Protein extraction, Cy3 labeling, and sonication of islet samples.
• Lectin microarray analysis to detect and quantify glycan binding.

Main Results:

• GKO pig islets exhibited reduced signals for GS-I-B4, PNA, WFA, PTL-I, and GS-I-A4 compared to WT pig islets, indicating decreased α-linked GalNAc and Galβ1-3GalNAc.
• Human islets showed stronger signals for UEA-I, AAL, TJA-II, EEL, WFA, HPA, DBA, SBA, and PTL-I than pig islets, suggesting higher fucose and α-linked GalNAc content.
• Adult pig islets (APIs) were significantly richer in high-mannose glycans compared to human islets.

Conclusions:

• Gene knockout of α1-3galactosyltransferase effectively reduced α-linked GalNAc in pig islets, even with negligible Gal antigen expression.
• Significant differences in glycan profiles exist between pig and human islets, particularly concerning high-mannose structures.
• These findings offer valuable insights for future xenotransplantation strategies and glycan modification research.