Frontiers in Immunology (Mar 2022)

Adaptation of Imaging Mass Cytometry to Explore the Single Cell Alloimmune Landscape of Liver Transplant Rejection

  • Nolan Ung,
  • Cameron Goldbeck,
  • Cameron Goldbeck,
  • Cassandra Man,
  • Cassandra Man,
  • Julianne Hoeflich,
  • Julianne Hoeflich,
  • Ren Sun,
  • Arianna Barbetta,
  • Arianna Barbetta,
  • Naim Matasci,
  • Jonathan Katz,
  • Jerry S. H. Lee,
  • Jerry S. H. Lee,
  • Jerry S. H. Lee,
  • Shefali Chopra,
  • Shefali Chopra,
  • Shahab Asgharzadeh,
  • Shahab Asgharzadeh,
  • Mika Warren,
  • Mika Warren,
  • Linda Sher,
  • Linda Sher,
  • Rohit Kohli,
  • Rohit Kohli,
  • Omid Akbari,
  • Omid Akbari,
  • Yuri Genyk,
  • Yuri Genyk,
  • Juliet Emamaullee,
  • Juliet Emamaullee,
  • Juliet Emamaullee

DOI
https://doi.org/10.3389/fimmu.2022.831103
Journal volume & issue
Vol. 13

Abstract

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Rejection continues to be an important cause of graft loss in solid organ transplantation, but deep exploration of intragraft alloimmunity has been limited by the scarcity of clinical biopsy specimens. Emerging single cell immunoprofiling technologies have shown promise in discerning mechanisms of autoimmunity and cancer immunobiology. Within these applications, Imaging Mass Cytometry (IMC) has been shown to enable highly multiplexed, single cell analysis of immune phenotypes within fixed tissue specimens. In this study, an IMC panel of 10 validated markers was developed to explore the feasibility of IMC in characterizing the immune landscape of chronic rejection (CR) in clinical tissue samples obtained from liver transplant recipients. IMC staining was highly specific and comparable to traditional immunohistochemistry. A single cell segmentation analysis pipeline was developed that enabled detailed visualization and quantification of 109,245 discrete cells, including 30,646 immune cells. Dimensionality reduction identified 11 unique immune subpopulations in CR specimens. Most immune subpopulations were increased and spatially related in CR, including two populations of CD45+/CD3+/CD8+ cytotoxic T-cells and a discrete CD68+ macrophage population, which were not observed in liver with no rejection (NR). Modeling via principal component analysis and logistic regression revealed that single cell data can be utilized to construct statistical models with high consistency (Wilcoxon Rank Sum test, p=0.000036). This study highlights the power of IMC to investigate the alloimmune microenvironment at a single cell resolution during clinical rejection episodes. Further validation of IMC has the potential to detect new biomarkers, identify therapeutic targets, and generate patient-specific predictive models of clinical outcomes in solid organ transplantation.

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