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

Pregnancy Alloimmunization Increases the Clonality of the Endogenous Treg Repertoire

K. Krupp, E. Lewis, R. Xu, P. Porrett

University of Pennsylvania, Philadelphia, PA

Meeting: 2020 American Transplant Congress

Abstract number: D-377

Keywords: Alloantigens, Pregnancy, T cell receptors (TcR), Tolerance

Session Information

Session Name: Poster Session D: Tolerance / Immune Deviation

Session Type: Poster Session

Date: Saturday, May 30, 2020

Session Time: 3:15pm-4:00pm

 Presentation Time: 3:30pm-4:00pm

Location: Virtual

*Purpose: Pregnancy is a common immune sensitizing event, which creates an access barrier to organ transplantation and can impact transplant outcomes. While most research has focused on how fetal antigen primes conventional maternal T cells, pregnancy also primes the expansion of protective alloreactive regulatory T cells (Tregs). Pregnancy thus represents a unique model of Treg expansion, which may yield insight into the therapeutic use of Tregs in transplantation. Importantly, prior studies have characterized maternal Treg responses to transgenic fetal antigens, which necessarily provide a limited view of pregnancy-induced expansion. Here we use bulk TCR sequencing to assess the effect of pregnancy alloimmunization on the endogenous polyclonal Treg repertoire.

*Methods: Female Foxp3GFP Treg reporter mice were mated with either syngeneic B6 or allogeneic Balb/c males or left as naive virgin controls. Maternal Tregs were sorted from peripheral blood collected prior to mating and late in pregnancy (embryonic day 18). TCR sequencing was performed on genomic DNA using the ImmunoSeqTM assay (Adaptive Biotechnologies).

*Results: An average of 478 (SD=206) productive Treg clones/mouse were identified at each timepoint. Despite the limitations imposed by sampling depth, we detected expansion of a subset of Treg clones during allogeneic pregnancy, which produced an increase in the overall clonality of the Treg repertoire [Figure]. Notably, no change in clonality was observed in either syngeneic pregnancy or naive controls. We identified 22 Treg clones that expanded in response to allogeneic mating compared with 2 clones that expanded in syngeneic pregnancy. These 22 clones represent 0.46% of all Treg clones sampled at either timepoint (vs. 0.087% in the syngeneic condition). We did not detect any clones that expanded in the naive controls. Collectively, these results indicate alloantigen-driven expansion of select Treg clones as a result of pregnancy-induced immune sensitization.

*Conclusions: Pregnancy is one of few immunization events that promotes the expansion of allogeneic Tregs. Using TCR sequencing, we were able to demonstrate this expansion over the course of allogeneic pregnancy, and characterize the resulting shift in clonality that occured in the endogenous Treg repertoire. Further study of Treg biology during pregnancy may help to guide the development of Treg-based therapies that regulate immune responses to alloantigen in transplantation.

 border=

  • Tweet
  • Email
  • Print

To cite this abstract in AMA style:

Krupp K, Lewis E, Xu R, Porrett P. Pregnancy Alloimmunization Increases the Clonality of the Endogenous Treg Repertoire [abstract]. Am J Transplant. 2020; 20 (suppl 3). https://atcmeetingabstracts.com/abstract/pregnancy-alloimmunization-increases-the-clonality-of-the-endogenous-treg-repertoire/. Accessed May 9, 2025.

« Back to 2020 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