EKFS grant | Metabolic reconditioning of steatotic rat liver grafts by normothermic ex vivo machine perfusion
Stacks Image 24186
The Else Kröner Fresenius Stiftung will fund the project "Metabolic reconditioning of steatotic rat liver grafts by normothermic ex vivo machine perfusion" (PI: Priv.-Doz. Dr. Nathanael Raschzok) for two years.

Liver transplantation is the treatment of choice for end-stage liver disease, yet the number of transplant candidates constantly exceeds the organ supply. The imbalance between demand and supply of liver grafts is dramatically exacerbated by the rising prevalence of obesity and the metabolic syndrome, which both show a strong correlation with steatosis hepatis. Liver grafts with macrovesicular steatosis above 30% are associated with delayed graft function and lower graft and patient survival, and livers with >60% steatosis are generally discarded from transplantation. Within the next 10 years, the overall liver graft utilization could potentially be halved due to the rising prevalence of steatosis, emphasizing the urgent clinical need to find solutions to make steatotic livers acceptable for transplantation.

In this project the hypothesis is tested whether metabolic reprogramming of steatotic liver grafts will 1) restore hepatocyte function, 2) activate lipid catabolism, 3) increase resistance to ischemia reperfusion damage, and 4) alleviate overwhelming inflammatory processes in the early phase of post-transplant regeneration with beneficial long-term impact for graft function and recipient survival.
Stacks Image 27655
Our manuscript "Depletion of donor dendritic cells ameliorates immunogenicity of both skin and hind limb transplants" has been accepted for publication in Frontiers in Immunology, section Alloimmunity and Transplantation. Authors are Muhammad Imtiaz Ashraf, Joerg Mengwasser, Anja Reutzel-Selke, Dietrich Polenz, Kirsten Führer, Steffen Lippert, Peter Tang, Edward Michaelis, Rusan Catar, Johann Pratschke, Christian Witzel, Igor M. Sauer, Stefan G. Tullius, and Barbara Kern.

Acute cellular rejection remains a significant obstacle affecting successful outcomes of organ transplantation including vascularized composite tissue allografts (VCA). Donor antigen presenting cells (APC), particularly dendritic cells (DC), orchestrate early alloimmune responses by activating recipient effector T cells. Employing a targeted approach, we investigated the impact of donor-derived conventional DC (cDC) and APC on the immunogenicity of skin and skin-containing VCA grafts, using mouse models of skin and hind limb transplantation.
By post-transplantation day 6, skin grafts demonstrated severe rejections, characterized by predominance of recipient CD4 T cells. In contrast, hind limb grafts showed moderate rejection, primarily infiltrated by CD8 T cells. While donor depletion of cDC and APC reduced frequencies, maturation, and activation of DC in all analysed tissues of skin transplant recipients, reduction in DC activities was only observed in the spleen of hind limb recipients. Donor cDC and APC depletion did not impact all lymphocyte compartments but significantly affected CD8 T cells and activated CD4 T in lymph nodes of skin recipients. Moreover, both donor APC and cDC depletion attenuated the Th17 immune response, evident by significantly reduced Th17 (CD4+IL-17+) cells in the spleen of skin recipients and reduced levels of IL-17E and lymphotoxin-α in the serum samples of both skin and hind limb recipients. In conclusion, our findings underscore the highly immunogenic nature of skin component in VCA. The depletion of donor APC and cDC mitigates the immunogenicity of skin grafts while exerting minimal impact on VCA.




This website or its third-party tools use cookies, which are necessary to its functioning and required to achieve the purpose illustrated in the Disclaimer. By closing this banner, scrolling this page, clicking a link or continuing to browse otherwise, you agree to the use of cookies.