S231: GLUCOCORTICOID AND GLYCOLYSIS INHIBITORS COOPERATIVELY ABROGATE ACUTE GRAFT-VERSUS-HOST DISEASE

Abstract

Background: Although glucocorticoids(GCs) are the standard first-line therapy for acute graft-versus-host disease(aGvHD), approximately 50% of aGvHD patients have no response to GCs. The role of T cell metabolism in murine aGvHD has been recently reported. Pharmacological inhibition of glycolysis by targeting 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3(PFKFB3) ameliorates aGvHD. However, the question of whether glycolysis is required for the function of activated T cells and whether abnormal glycolysis is involved in the occurrence of human aGvHD need to be elucidated. Moreover, the issue as to whether GCs and metabolism regulators can cooperatively suppress T cell alloreactivity and ameliorate aGvHD remains to be elucidated. Aims: The study aimed to analyse the glucose metabolism profiles of activated T cells in aGvHD patients, and to evaluate the roles of PFKFB3-stimulated glycolysis in alloantigen-activated T cells and aGvHD induction. Furthermore, the study was performed to explore the issue of whether GCs could restore activated T cells by regulating glycolysis and the effect of GCs combined with glycolysis inhibitors on activated T cells. Methods: In this prospective nested case–control study, a total of 15 aGvHD patients at diagnosis and 15 matched non-aGvHD patients. The glucose consumption and lactate production rates were detected by glucose assay kit and lactate assay kit. Subsequently, to assess whether functional T cell activation is caused by the regulation of PFKFB3, we used lentivirus transduction for the genetic regulation of PFKFB3 in vitro and in a humanized xenogeneic aGvHD model. The effect of GCs and glycolysis inhibitors on activated T cells was further explored in vitro and in a humanized murine model of aGvHD and graft versus leukaemia (GVL). In addition, to evaluate the synergistic effect of GCs, 3PO or their combination, combination index (CI) studies were performed by using the Chou-Talalay method for drug interactions. Results: Increased glycolysis, which was characterized by elevated PFKFB3, as well as higher rates of glucose consumption and lactate production in aGvHD T cells. Importantly, in vitro treatment with glycolysis inhibitor 3PO improved the activity of T cells derived from aGvHD patients through down-regulating glycolytic activity of T cells. Genetic upregulation of PFKFB3 induced T cell proliferation and differentiation into proinflammatory T cells. In a humanized mouse model, PFKFB3-overexpressing T cells aggravated aGvHD, as characterized by high aGvHD clinical scores, pathological scores and rapid lethality. Importantly, our integrated data from patient samples in vitro showed that GCs combined with 3PO decreased proinflammatory T cells and T cell proliferation, reduced glucose consumption, lactate production and PFKFB3 expression compared with the single GCs group. Notably, the average CI values of GCs and 3PO were 0.364 for the synergistic inhibition of IFN-γ synthesis and 0.475 for the synergistic inhibition of proliferation, respectively. In a humanized murine model of aGvHD and GVL demonstrated that GCs and 3PO cooperatively reduced the alloreactivity of T cells and ameliorate aGvHD without a loss of GVL effects. Summary/Conclusion: Our data indicated that glycolysis is critical for T cell activation and the induction of human aGvHD. GCs combined with glycolysis inhibitors demonstrated synergistic effects on reducing T cell alloreactivity and ameliorating aGvHD by regulating T cell glycolysis in vitro and in vivo. Thus, GCs combined with glycolysis inhibitors promise to be a novel therapeutic strategy for aGvHD patients.