Modulating endothelial cell immunometabolism and mitochondrial morphologyimplications for organ transplantation

Aim 1. We will determine the impact of mitochondrial morphology during organ preservation on the immunogenicity of endothelial cells in vitro. We will examine the mitochondrial morphology and immune consequence of micro and macro- vascular ECs in normal and cold ischemic environments. Building upon our preliminary data, we will identify the morphologic features of mitochondria as they correlate to the EC energy signature and expression of co-stimulation markers in the setting of EC-T cell interactions in vitro. We anticipate that tubular morphology of mitochondria will correlate to an anti-inflammatory effect, resulting in reduced proinflammatory cytokine expression, as well as EC-T cell co-stimulatory molecule expression. Aim 2. We aim to assess the impact of mitochondrial morphology on ischemia reperfusion injury (IRI) and acute transplant rejection (AR) in vivo. Using a mouse heterotopic cardiac transplant model to assess for IRI and AR, we will pre-treat organs with a soluble small molecule combination peptide consisting of a mitochondrial fusion promoter/fission inhibitor (M1/Mdivi-1). We will deliver these therapies both ex vivo in cold preservation and in vivo using a novel normothermic mouse brain death model established in our laboratory (2). We hypothesize that M1/Mdivi-1 therapy during cold storage or administered in vivo during brain death will not only prolong graft survival, which we show in our preliminary studies, but will also inhibit effector T cell activation and graft infiltration.