Therapeutic targeting of metabolic interactions between cancer and immune cells to improve the graft-versus-leukemia effect

• Applicant: Professorin Dr. Petya Apostolova
• Subject Area: Hematology, Oncology ; Immunology
• Term: from 2021 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 492259164

• Final Report Year: 2024

Final Report Abstract

Acute myeloid leukemia (AML) can be cured by an allogeneic hematopoietic stem cell transplantation (allo-HSCT) with donor immune cells exerting long-term malignancy control through immunosurveillance. However, AML relapses due to immune evasion occur in >30% of the AML patients and have a dismal prognosis. Intracellular metabolism is an essential regulator of AML chemotherapy resistance, but less is known about the role of metabolism for immune evasion after allo-HSCT. I hypothesized that selection pressure through chemotherapy might induce metabolic reprogramming in AML cells and, as a consequence of these metabolic adaptations, AML cell resistance to immune-mediated cytotoxicity might increase. I aimed to define stress-induced metabolic pathways in AML and to study their functional importance for the anti-tumor immune response. I found a substantially increased creatine abundance in therapypersisting AML cells across different treatments in three distinct models (HL-60 and RMB-1 in vitro, and MLLPTD/+ FLT3ITD/+ AML in vivo). I determined that creatine uptake occurred via the transporter SLC6A8, which was upregulated after chemotherapy in a p53-dependent manner. CRISPR-Cas9-induced silencing of Slc6a8 in AML cell lines significantly reduced the leukemia engraftment and improved the survival of AML-bearing mice in three separate models of allo- HSCT with allogeneic CD4+/CD8+ T cell transfer. Strikingly, SLC6A8-deficient AML cells had unperturbed proliferation rates and sensitivity to chemotherapy in the absence of allogeneic T cells, demonstrating that SLC6A8 regulated AML susceptibility to the anti-tumor immune response rather than cell survival or proliferation. I hypothesized that the elevated SLC6A8 expression by AML cells might lead to creatine depletion from the environment and thus impair the function of cytotoxic T cells, which were also dependent on creatine uptake. However, quantification of creatine in the bone marrow fluid of mice and patients revealed that creatine was abundant even in the presence of AML cells. Next, I hypothesized that creatine metabolism might affect AML cell recognition by the immune system or their resistance to immunemediated killing. Indeed, I found that SLC6A8 silencing resulted in an increased expression of MHC class II molecules. Finally, I observed that primary human AML cells expressed higher levels of SLC6A8 than healthy CD34+ cells, making creatine metabolism a potential target for boosting the anti-leukemia immunity. In summary, I observed that cytotoxic pressure through chemotherapy induced a metabolic reprogramming in several AML models, characterized by an elevated uptake of creatine via the transporter SLC6A8. SLC6A8-silenced cells were more efficiently rejected by allogeneic CD4+/CD8+ T cells in mouse models of allo-HSCT. I propose creatine uptake via SLC6A8 as a novel biological mechanism regulating AML susceptibility to the anti-tumor immune response.

Publications

• Lactic acid and lactate: revisiting the physiological roles in the tumor microenvironment. Trends in Immunology, 43(12), 969-977.
  Apostolova, Petya & Pearce, Erika L.
  
• Phosphoinositide acyl chain saturation drives CD8+ effector T cell signaling and function. - Oral presentation at the "Immunometabolism: Fundamentals to Prospective New Therapies" conference, Boston, USA, November 2022
  Apostolova P., Edwards-Hicks J. et al.
  
• Targeting MDM2 enhances antileukemia immunity after allogeneic transplantation via MHC-II and TRAIL-R1/2 upregulation. Blood, 140(10), 1167-1181.
  Ho, Jenny N. H. G.; Schmidt, Dominik; Lowinus, Theresa; Ryoo, Jeongmin; Dopfer, Elaine-Pashupati; Gonzalo, Núñez Nicolás; Costa-Pereira, Sara; Toffalori, Cristina; Punta, Marco; Fetsch, Viktor; Wertheimer, Tobias; Rittmann, Marie-Claire; Braun, Lukas M.; Follo, Marie; Briere, Christelle; Vinnakota, Janaki Manoja; Langenbach, Marlene; Koppers, Felicitas; Shoumariyeh, Khalid ... & Zeiser, Robert
  
• Targeting the creatine metabolism crosstalk between malignant cells and T cells for the treatment of acute myeloid leukemia. - Oral presentation at the Keystone Symposium "Immunometabolism at the Crossroads of Obesity and Cancer", Keystone, USA, September 2022
  Apostolova P. et al.
  
• Allo-HCT: damaged T cells don’t bite. Blood, 141(13), 1507-1508.
  Apostolova, Petya
  
• Experimental Hematology 124 S59 - Poster at the Annual Meeting of the International Society of Experimental Hematology, New York, USA, August 2023
  Apostolova P. et al.
  
• Phase II trial of hypomethylating agent combined with nivolumab for acute myeloid leukaemia relapse after allogeneic haematopoietic cell transplantation—Immune signature correlates with response. British Journal of Haematology, 203(2), 264-281.
  Apostolova, Petya; Kreutmair, Stefanie; Toffalori, Cristina; Punta, Marco; Unger, Susanne; Burk, Ann‐Cathrin; Wehr, Claudia; Maas‐Bauer, Kristina; Melchinger, Wolfgang; Haring, Eileen; Hoefflin, Rouven; Shoumariyeh, Khalid; Hupfer, Valerie; Lauer, Eliza Maria; Duquesne, Sandra; Lowinus, Theresa; Gonzalo, Núñez Nicolás; Alberti, Chiara; da Costa, Pereira Sara ... & Zeiser, Robert
  
• Phosphoinositide acyl chain saturation drives CD8+ effector T cell signaling and function. Nature Immunology, 24(3), 516-530.
  Edwards-Hicks, Joy; Apostolova, Petya; Buescher, Joerg M.; Maib, Hannes; Stanczak, Michal A.; Corrado, Mauro; Klein, Geltink Ramon I.; Maccari, Maria Elena; Villa, Matteo; Carrizo, Gustavo E.; Sanin, David E.; Baixauli, Francesc; Kelly, Beth; Curtis, Jonathan D.; Haessler, Fabian; Patterson, Annette; Field, Cameron S.; Caputa, George; Kyle, Ryan L. ... & Pearce, Erika L.