Korean J Transplant.  2023 Nov;37(Suppl 1):S193. 10.4285/ATW2023.F-7778.

Applying integrative multiomic profiling in two human decedents receiving pig heart xenografts reveals early immune cell responses indicative of perioperative cardiac xenograft dysfunction

• Keating B
• Montgomery R
• Schmauch E
• Piening B
• Snyder M

• KMID: 2551813
• DOI: http://doi.org/10.4285/ATW2023.F-7778

Abstract

Background
Recent advances in xenotransplantation in living and decedent humans using pig heart xenografts have laid promising groundwork towards future emergency use and first-in-human trials. Major obstacles remain however, including a lack of knowledge of the genetic incompatibilities between pig donors and human recipients, which may lead to harmful immune responses against the xenograft and/or physiological dysfunction. In 2022, two gene-edited pig heart xenografts were transplanted into two brain-dead human decedents, primarily to evaluate onset of hyper-acute antibody mediated rejection and sustained xenograft function over 3-days.
Methods
We performed multiomic profiling to assess the dynamic interactions between two pig heart-xenografts transplanted into two human decedents. We generated transcriptomic, lipidomic, proteomic and metabolomics datasets, across blood samples every 6 hours, as well as histological and transcriptomic tissue profiling, over the 3-day procedures to biological changes that correlate with immune-related outcomes and xenograft function.
Results
In decedent 1 we observed early immune-activation changes in Peripheral Blood Mononuclear Cells (using single-cell RNA-seq) and xenograft tissue (using single-nuclei RNA-seq and spatial transcriptomics) leading to profound downstream T cell and NK cell activity, which collectively represented over 20% of all blood cells in the final 3-day procedure timepoints. Longitudinal multiomic integrative analyses from blood and tissue, indicates ischemia reperfusion injury (IRI) in decedent 1, which is exacerbated by minimal immunosuppression of T cells, is consistent with perioperative cardiac xenograft dysfunction transcriptome signatures. We also observe significant cellular metabolism and liver damage pathway changes after 42 hours in decedent 1 that correlates with organ-wide physiological dysfunction. Decedent 2 had normal xenograft functioning with relatively minor changes across the multiomic profiling datasets.
Conclusions
Single-cell and multi omics approaches reveal fundamental insights into early molecular and immune responses indicative of IRI and perioperative cardiac xenograft dysfunction in a human decedent model receiving gene-modified pig heart xenografts, that were not evident in the initial clinical findings.