Session: 701. Experimental Transplantation: Basic and Translational: Poster I
Hematology Disease Topics & Pathways:
Research, Translational Research
Transplantation of PPARd KO T cells into allogeneic recipients modestly increased survival but did not fully ameliorate GVHD. This led us to hypothesize that compensatory metabolic pathways were being engaged in PPARδ KO T cells. To test this idea, wildtype (WT) and KO donor CD8 T cells were harvested from allogeneic recipient spleens on day 7 post-transplant, followed by targeted and untargeted metabolomic analyses on cell lysates. Targeted metabolite analysis revealed elevated levels of glutamine and succinate in PPARδ KO T cells, suggesting an uptick in glutamine metabolism in these cells. Furthermore, mass spectrometry discovered and validated two unique metabolites during untargeted analysis. O-phosphorylethanolamine levels were 0.64-fold lower, whereas pantothenic acid levels (vitamin B5) were 2.93-fold higher (p<0.01) in KO CD8 T cells. Pantothenic acid can be readily catabolized to replenish the cell’s coenzyme-A (CoA) pools, which influences T cell homeostasis and polarization, as well as being acetylated into acetyl-CoA to serve as a TCA fuel source. Thus, alloreactive CD8 donor T cells appear to adapt to loss of PPARδ through the upregulation of glutamine metabolism and an increased reliance on metabolid fuels provide through the panthothenate pathway. Future work will interrogate the vitamin B5/CoA axis in PPARδ KO alloreactive CD8 T and examine potential upstream influence by AMPK and mTOR, the two primary energy regulators of T cells, with the long-term goal of pinpointing therapeutic targets in reducing GVHD.
Disclosures: No relevant conflicts of interest to declare.
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