BACKGROUND: Normothermic ex vivo liver perfusion (NEVLP) is a novel system for organ preservation which may improve over static cold storage (CS) clinically and offers the chance for graft modification prior to transplantation. Although recent studies have shown the presence of inflammatory molecules during perfusion, none have yet shown the effects of NEVLP on liver-resident immune cell activation. We investigated the effects of NEVLP on liver-resident immune cell activation and assessed the ability of anti-inflammatory cytokines IL-10 and TGF-β to improve organ function and reduce immune activation during perfusion. METHODS: Rat livers were perfused for 4 hours at 37°C with or without the addition of 20ng/mL each IL-10 and TGF-β (n=7). Naïve and cold storage (4 hours at 4°C) livers served as controls (n=4). Following preservation, gene expression profiles were assessed through single cell RNA sequencing, dendritic cell and macrophage activation was measured by flow cytometry, and cytokine production was assessed by ELISA. RESULTS: NEVLP induced a global inflammatory gene expression signature, most notably in liver-resident macrophages and dendritic cells, which was accompanied by an increase in cell-surface levels of MHC II, CD40, and CD86. Immune activation was partially ameliorated by IL-10 and TGF-β treatment, but no changes were observed in inflammatory cytokine production. Overall levels of liver damage and cellular apoptosis from perfusion were low, and liver function was improved with IL-10 and TGF-β treatment. CONCLUSIONS: This is the first study to demonstrate that liver-resident immune cells gain an activated phenotype during NEVLP on both the gene and protein level and that this activation can be reduced through therapeutic intervention with IL-10 and TGF-β. This article is protected by copyright. All rights reserved.
BACKGROUND: Normothermic ex vivo liver perfusion (NEVLP) is a novel system for organ preservation which may improve over static cold storage (CS) clinically and offers the chance for graft modification prior to transplantation. Although recent studies have shown the presence of inflammatory molecules during perfusion, none have yet shown the effects of NEVLP on liver-resident immune cell activation. We investigated the effects of NEVLP on liver-resident immune cell activation and assessed the ability of anti-inflammatory cytokines IL-10 and TGF-β to improve organ function and reduce immune activation during perfusion. METHODS:Rat livers were perfused for 4 hours at 37°C with or without the addition of 20ng/mL each IL-10 and TGF-β (n=7). Naïve and cold storage (4 hours at 4°C) livers served as controls (n=4). Following preservation, gene expression profiles were assessed through single cell RNA sequencing, dendritic cell and macrophage activation was measured by flow cytometry, and cytokine production was assessed by ELISA. RESULTS: NEVLP induced a global inflammatory gene expression signature, most notably in liver-resident macrophages and dendritic cells, which was accompanied by an increase in cell-surface levels of MHC II, CD40, and CD86. Immune activation was partially ameliorated by IL-10 and TGF-β treatment, but no changes were observed in inflammatory cytokine production. Overall levels of liver damage and cellular apoptosis from perfusion were low, and liver function was improved with IL-10 and TGF-β treatment. CONCLUSIONS: This is the first study to demonstrate that liver-resident immune cells gain an activated phenotype during NEVLP on both the gene and protein level and that this activation can be reduced through therapeutic intervention with IL-10 and TGF-β. This article is protected by copyright. All rights reserved.
Entities:
Keywords:
Allograft tolerance; Dendritic cell; Macrophage; Organ preservation; Transplantation
Authors: Heather Jennings; Kristin N Carlson; Chris Little; Joshua C Verhagen; Jeevan Nagendran; Yongjun Liu; Bret Verhoven; Weifeng Zeng; Stacey McMorrow; Peter Chlebeck; David P Al-Adra Journal: Front Immunol Date: 2022-06-22 Impact factor: 8.786