ATC Abstracts

American Transplant Congress abstracts

  • Home
  • Meetings Archive
    • 2022 American Transplant Congress
    • 2021 American Transplant Congress
    • 2020 American Transplant Congress
    • 2019 American Transplant Congress
    • 2018 American Transplant Congress
    • 2017 American Transplant Congress
    • 2016 American Transplant Congress
    • 2015 American Transplant Congress
    • 2013 American Transplant Congress
  • Keyword Index
  • Resources
    • 2021 Resources
    • 2016 Resources
      • 2016 Welcome Letter
      • ATC 2016 Program Planning Committees
      • ASTS Council 2015-2016
      • AST Board of Directors 2015-2016
    • 2015 Resources
      • 2015 Welcome Letter
      • ATC 2015 Program Planning Committees
      • ASTS Council 2014-2015
      • AST Board of Directors 2014-2015
      • 2015 Conference Schedule
  • Search

Ex Vivo Modification of Vascular Allografts Using Immunosuppressive and Anti-Inflammatory Polymers Prevent Rejection via Localized Immunosuppression

H. D. Luo1, E. M. Siren1, W. Enns2, L. Sim1, C. Du1, S. G. Withers1, J. Choy3, J. N. Kizhakkedathu1

1The University of British Columbia, Vancouver, BC, Canada, 2Simon Fraser University, Burnaby, BC, Canada, 3Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada

Meeting: 2022 American Transplant Congress

Abstract number: 167

Keywords: Endothelial cells, Immunosuppression, Kidney transplantation, Perfusion

Topic: Basic Science » Basic Science » 12 - Immunosuppression & Tolerance: Preclinical & Translational Studies

Session Information

Session Name: Immunosuppression and Tolerance: Preclinical and Translational Studies

Session Type: Rapid Fire Oral Abstract

Date: Sunday, June 5, 2022

Session Time: 5:30pm-7:00pm

 Presentation Time: 5:30pm-5:40pm

Location: Hynes Ballroom A

*Purpose: Classical immunosuppressants lead to systemic immune shutdown, though necessary to mediate transplant rejection, it may lead to various complications. To reduce off-target immunosuppression while retaining increased transplant survival, we propose direct modification of the endothelium of vascular transplants ex vivo to achieve localized immunomodulation. We developed an enzymatic approach to modify the surface of the endothelium at the transplant storage conditions using novel non-toxic immunosuppressive and anti-inflammatory/anti-oxidant polymers. We tested the efficacy of this approach for immunosuppression and reduction in graft rejection.

*Methods: We developed an enzymatic organ engineering method using tissue transglutaminase and polyglycerol polymer conjugates containing immunosuppressive sialic acid or sulfate moieties. In vitro mechanistic studies were performed using EaHy.926 cells to replicate the endothelium. In vivo experiments were done using mice models allograft blood vessel and renal transplantation. The performance of the modification was assessed using serum, and histological examination of tissue sections of excised transplants.

*Results: Enzyme-mediated engineering endothelial surfaces of cultured cells, blood vessels and kidneys using polymers under static cold storage conditions (in UW solution at 4 °C) resulted in uniform modification. In vitro, modified endothelial cells were able to evade immune cell (CAR T Cell and PBMC) induced cytotoxicity, prevented protein leakage and possessed increased scavenging activity of ROS. Modification reduced TNF release in M1-like monocytes. In transplant setting, reduced early inflammation in transplants correlated with reduced medial thickening and pro-inflammatory markers in serum. In turn, this resulted in long-term survival of vessel transplant without rejection in the absence of immune suppressants. Histological analysis of engineered renal grafts revealed less infiltration and mesangial expansion and normal kidney function relating to a healthier graft. Furthermore, de novo generation of donor-specific antibody was reduced in engineered grafts.

*Conclusions: We have developed a novel organ engineering approach that prevents immune-mediated rejection of transplants via improved vascular protection. Ex-vivo engineering using immune cloaking polymers allow for localized immunosuppression, making this an enticing and viable strategy for elimination or reduction in the use of broad-acting immunosuppressants.

  • Tweet
  • Click to email a link to a friend (Opens in new window) Email
  • Click to print (Opens in new window) Print

To cite this abstract in AMA style:

Luo HD, Siren EM, Enns W, Sim L, Du C, Withers SG, Choy J, Kizhakkedathu JN. Ex Vivo Modification of Vascular Allografts Using Immunosuppressive and Anti-Inflammatory Polymers Prevent Rejection via Localized Immunosuppression [abstract]. Am J Transplant. 2022; 22 (suppl 3). https://atcmeetingabstracts.com/abstract/ex-vivo-modification-of-vascular-allografts-using-immunosuppressive-and-anti-inflammatory-polymers-prevent-rejection-via-localized-immunosuppression/. Accessed May 30, 2025.

« Back to 2022 American Transplant Congress

Visit Our Partner Sites

American Transplant Congress (ATC)

Visit the official site for the American Transplant Congress »

American Journal of Transplantation

The official publication for the American Society of Transplantation (AST) and the American Society of Transplant Surgeons (ASTS) »

American Society of Transplantation (AST)

An organization of more than 3000 professionals dedicated to advancing the field of transplantation. »

American Society of Transplant Surgeons (ASTS)

The society represents approximately 1,800 professionals dedicated to excellence in transplantation surgery. »

Copyright © 2013-2025 by American Society of Transplantation and the American Society of Transplant Surgeons. All rights reserved.

Privacy Policy | Terms of Use | Cookie Preferences