The Anti-Inflammatory Effect of Normothermic Machine Perfused Human Kidneys on Monocyte-Derived Dendritic Cells.

Abstract

Background: The immunomodulatory activity of normothermic machine perfusion (NMP) on donor organs may be reflected by the release of immune-regulating factors into the perfusate. Dendritic cells (DCs) are potent antigen-presenting cells and are able to sense these factors. We hypothesized that activation of DCs could be used to monitor the release of these mediators into the perfusate.

Methods: Human monocytes from buffy coats were differentiated into monocyte-derived DCs (moDCs). Perfusate was obtained from human donor kidneys deemed unsuitable for transplantation (n = 15) that underwent 6 h of NMP. MoDCs were incubated for 24 h with perfusate collected at different timepoints. DC supernatant was analyzed with Luminex and ELISA. MoDCs were analyzed with flow cytometry for maturation markers and co-cultured with allogenic T cells.

Results: Incubation with perfusate resulted in moDCs with a reduced surface expression of CD86, without affecting other maturation markers. Analysis of DC supernatant showed there was a specific increase of IL-10 production upon incubation with perfusate. As a consequence, moDCs incubated with perfusate showed lower T cell stimulatory capacity.

Conclusion: This study showed that the activation status of DCs can be used to monitor the release of factors into the perfusate during NMP with an anti-inflammatory DC phenotype and function. It demonstrates the feasibility of a cell-based model to determine immune regulatory effects during ex vivo organ perfusion.