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Thrombin receptor activating peptide-6 decreases acute graft-versus-host disease through activating GPR15


G-protein coupled receptor 15 (GPR15) is expressed on T-cells. We previously reported knockout of GPR15 increased acute graft-versus-host disease (GvHD) in mice. In this study, we identified thrombin receptor activating peptide-6 (TRAP-6, peptide sequence: SFLLRN) as an activator of GPR15. GRP15 and β-arrestin2 were needed for TRAP-6-mediated inhibition of mixed lymphocyte reactions. TRAP-6 decreased acute GvHD in allotransplant models in mice, an effect dependent on GPR15-expression in donor T-cells. RNA-seq and protein analyses indicated TRAP-6 increased binding of β-arrestin2/TAB1 and inhibited phosphorylation of TAK1 and NF-κB-P65. GPR15 is expressed differently on CD4+ T-cells and CD8+ T-cells. TRAP-6 inhibited phosphorylation of NF-κB-P65 in CD4+ T-cells but increased granzyme B expression in CD8+ T-cells. TRAP-6 decreased acute GvHD without inhibiting graft-versus-tumor (GvT) efficacy against A20 lymphoma cells. SALLRN, a mutant of TRAP-6, preserved the anti-acute GvHD effect but avoided the adverse effects of TRAP-6. TRAP-6 and SALLRN also decreased allogeneic and xenogeneic reactions induced by human blood mononuclear cells. In conclusion, TRAP-6 activated GPR15 on T-cells and decreased acute GvHD in mice without impairing GvT efficacy.

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Fig. 1: TRAP-6 activates GPR15/β-arrestin2 signal and inhibits mixed lymphocyte reaction in vitro.
Fig. 2: TRAP-6 decreases murine acute GvHD in a GPR15-dependent manner.
Fig. 3: The TRAP-6/GPR15 interaction and its impact on T-cell function in vitro.
Fig. 4: TRAP-6 decreases activation of NF-κB.
Fig. 5: TRAP-6 mutant (SALLRN) does not induce platelet aggregation but preserves the anti-alloreaction effect.
Fig. 6: TRAP-6 and Mutant #2 do not impair GvT effect.
Fig. 7: TRAP-6 and Mutant #2 inhibited allogeneic/xenogeneic reaction induced by human BMCs.

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Data availability

The datasets generated during the current study are available from the corresponding author on reasonable request.


  1. Penack O, Marchetti M, Aljurf M, Arat M, Bonifazi F, Duarte RF, et al. Prophylaxis and management of graft-versus-host disease after stem-cell transplantation for haematological malignancies: updated consensus recommendations of the European Society for Blood and Marrow Transplantation. Lancet Haematol. 2024;11:e147–e159.

    Article  CAS  PubMed  Google Scholar 

  2. Mohty M, Holler E, Jagasia M, Jenq R, Malard F, Martin P, et al. Refractory acute graft-versus-host disease: a new working definition beyond corticosteroid refractoriness. Blood. 2020;136:1903–6.

    Article  PubMed  Google Scholar 

  3. Choi SW, Reddy P. Current and emerging strategies for the prevention of graft-versus-host disease. Nat Rev Clin Oncol. 2014;11:536–47.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  4. Jagasia M, Perales MA, Schroeder MA, Ali H, Shah NN, Chen YB, et al. Ruxolitinib for the treatment of steroid-refractory acute GVHD (REACH1): a multicenter, open-label phase 2 trial. Blood. 2020;135:1739–49.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  5. Zeiser R, von Bubnoff N, Butler J, Mohty M, Niederwieser D, Or R, et al. Ruxolitinib for Glucocorticoid-Refractory Acute Graft-versus-Host Disease. N. Engl J Med. 2020;382:1800–10.

    Article  PubMed  Google Scholar 

  6. Horowitz MM, Gale RP, Sondel PM, Goldman JM, Kersey J, Kolb HJ, et al. Graft-versus-leukemia reactions after bone marrow transplantation. Blood. 1990;75:555–62.

    Article  CAS  PubMed  Google Scholar 

  7. Goldman JM, Gale RP, Horowitz MM, Biggs JC, Champlin RE, Gluckman E, et al. Bone marrow transplantation for chronic myelogenous leukemia in chronic phase. Increased risk for relapse associated with T-cell depletion. Ann Intern Med. 1988;108:806–14.

    Article  CAS  PubMed  Google Scholar 

  8. Blazar BR, Hill GR, Murphy WJ. Dissecting the biology of allogeneic HSCT to enhance the GvT effect whilst minimizing GvHD. Nat Rev Clin Oncol. 2020;17:475–92.

    Article  PubMed  PubMed Central  Google Scholar 

  9. Veenstra RG, Flynn R, Kreymborg K, McDonald-Hyman C, Saha A, Taylor PA, et al. B7-H3 expression in donor T cells and host cells negatively regulates acute graft-versus-host disease lethality. Blood. 2015;125:3335–46.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  10. Kim SV, Xiang WV, Kwak C, Yang Y, Lin XW, Ota M, et al. GPR15-mediated homing controls immune homeostasis in the large intestine mucosa. Science. 2013;340:1456–9.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  11. Pan B, Wang X, Kojima S, Nishioka C, Yokoyama A, Honda G, et al. The Fifth Epidermal Growth Factor-like Region of Thrombomodulin Alleviates Murine Graft-versus-Host Disease in a G-Protein Coupled Receptor 15 Dependent Manner. Biol Blood Marrow Transpl. 2017;23:746–56.

    Article  CAS  Google Scholar 

  12. Pan B, Shang L, Liu C, Gao J, Zhang F, Xu M, et al. PD-1 antibody and ruxolitinib enhances graft-versus-lymphoma effect without increasing acute graft-versus-host disease in mice. Am J Transpl. 2021;21:503–14.

    Article  CAS  Google Scholar 

  13. Cooke KR, Kobzik L, Martin TR, Brewer J, Delmonte J Jr., Crawford JM, et al. An experimental model of idiopathic pneumonia syndrome after bone marrow transplantation: I. The roles of minor H antigens and endotoxin. Blood. 1996;88:3230–9.

    Article  CAS  PubMed  Google Scholar 

  14. Kaplan DH, Anderson BE, McNiff JM, Jain D, Shlomchik MJ, Shlomchik WD. Target antigens determine graft-versus-host disease phenotype. J Immunol. 2004;173:5467–75.

    Article  CAS  PubMed  Google Scholar 

  15. Chandrabalan A, Ramachandran R. Molecular mechanisms regulating Proteinase-Activated Receptors (PARs). FEBS J. 2021;288:2697–726.

    Article  CAS  PubMed  Google Scholar 

  16. Hayden MS, Ghosh S. Shared principles in NF-kappaB signaling. Cell. 2008;132:344–62.

    Article  CAS  PubMed  Google Scholar 

  17. Kim S, Jin J, Kunapuli SP. Akt activation in platelets depends on Gi signaling pathways. J Biol Chem. 2004;279:4186–95.

    Article  CAS  PubMed  Google Scholar 

  18. Oh DY, Talukdar S, Bae EJ, Imamura T, Morinaga H, Fan W, et al. GPR120 is an omega-3 fatty acid receptor mediating potent anti-inflammatory and insulin-sensitizing effects. Cell. 2010;142:687–98.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  19. Pfleger J, Gresham K, Koch WJ. G protein-coupled receptor kinases as therapeutic targets in the heart. Nat Rev Cardiol. 2019;16:612–22.

    Article  PubMed  Google Scholar 

  20. Smith JS, Rajagopal S. The beta-Arrestins: Multifunctional Regulators of G Protein-coupled Receptors. J Biol Chem. 2016;291:8969–77.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  21. Sato S, Sanjo H, Takeda K, Ninomiya-Tsuji J, Yamamoto M, Kawai T, et al. Essential function for the kinase TAK1 in innate and adaptive immune responses. Nat Immunol. 2005;6:1087–95.

    Article  CAS  PubMed  Google Scholar 

  22. Mathew NR, Vinnakota JM, Apostolova P, Erny D, Hamarsheh S, Andrieux G, et al. Graft-versus-host disease of the CNS is mediated by TNF upregulation in microglia. J Clin Invest. 2020;130:1315–29.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  23. de Mooij CEM, Netea MG, van der Velden W, Blijlevens NMA. Targeting the interleukin-1 pathway in patients with hematological disorders. Blood. 2017;129:3155–64.

    Article  PubMed  Google Scholar 

  24. Koide SL, Inaba K, Steinman RM. Interleukin 1 enhances T-dependent immune responses by amplifying the function of dendritic cells. J Exp Med. 1987;165:515–30.

    Article  CAS  PubMed  Google Scholar 

  25. Iwasaki A, Medzhitov R. Control of adaptive immunity by the innate immune system. Nat Immunol. 2015;16:343–53.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  26. Gao J, Xu Y, Ma S, Liang Y, Liu C, Shen J, et al. Inhibition of IL-1 Receptor-Associated Kinase 1 Decreases Murine Acute Graft-versus-Host Disease While Preserving the Graft-versus-Lymphoma Effect. Transpl Cell Ther. 2022;28:134 e131–134.e110.

    Article  Google Scholar 

  27. Hernandez R, Poder J, LaPorte KM, Malek TR. Engineering IL-2 for immunotherapy of autoimmunity and cancer. Nat Rev Immunol. 2022;22:614–28.

    Article  CAS  PubMed  Google Scholar 

  28. Reddy P, Negrin R, Hill GR. Mouse models of bone marrow transplantation. Biol Blood Marrow Transpl. 2008;14:129–35.

    Article  Google Scholar 

  29. Ritter AT, Shtengel G, Xu CS, Weigel A, Hoffman DP, Freeman M, et al. ESCRT-mediated membrane repair protects tumor-derived cells against T cell attack. Science. 2022;376:377–82.

    Article  CAS  PubMed  Google Scholar 

  30. Tsukada N, Kobata T, Aizawa Y, Yagita H, Okumura K. Graft-versus-leukemia effect and graft-versus-host disease can be differentiated by cytotoxic mechanisms in a murine model of allogeneic bone marrow transplantation. Blood. 1999;93:2738–47.

    Article  CAS  PubMed  Google Scholar 

  31. Graubert TA, Russell JH, Ley TJ. The role of granzyme B in murine models of acute graft-versus-host disease and graft rejection. Blood. 1996;87:1232–7.

    Article  CAS  PubMed  Google Scholar 

  32. Hsieh MH, Korngold R. Differential use of FasL- and perforin-mediated cytolytic mechanisms by T-cell subsets involved in graft-versus-myeloid leukemia responses. Blood. 2000;96:1047–55.

    Article  CAS  PubMed  Google Scholar 

  33. Schmaltz C, Alpdogan O, Horndasch KJ, Muriglan SJ, Kappel BJ, Teshima T, et al. Differential use of Fas ligand and perforin cytotoxic pathways by donor T cells in graft-versus-host disease and graft-versus-leukemia effect. Blood. 2001;97:2886–95.

    Article  CAS  PubMed  Google Scholar 

  34. Schwab L, Goroncy L, Palaniyandi S, Gautam S, Triantafyllopoulou A, Mocsai A, et al. Neutrophil granulocytes recruited upon translocation of intestinal bacteria enhance graft-versus-host disease via tissue damage. Nat Med. 2014;20:648–54.

    Article  CAS  PubMed  Google Scholar 

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Prof. Robert Peter Gale (Imperial College of Science, Technology and Medicine) kindly revised the typescript.


This study is supported by National Natural Science Foundation of China (82170214, 82370218 and 81970159 to BP, 81871263 and 81930005 to KX), the Jiangsu Provincial Key Research and Development Program (BE2021631 to BP) and the Natural Science Research of the Jiangsu Higher Education Institutions of China (20KJA320002 to BP). This study also received funding from the Postgraduate Research & Practice Innovation Program of Jiangsu Province (KYCX22-2915).

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BP designed the project, analyzed data and revised the manuscript. KX and TI contributed to concept, revised the manuscript, and helped to design experiments. CL performed experiments, analyzed data and wrote the manuscript. QL and SC performed experiments and analyzed data (animal models, protein assays, and platelet detection). FZ, YL, JS and YW performed part of experiments. CL, QL and SC contributed equally to this study.

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Correspondence to Takayuki Ikezoe, Kailin Xu or Bin Pan.

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Liu, C., Lan, Q., Cao, S. et al. Thrombin receptor activating peptide-6 decreases acute graft-versus-host disease through activating GPR15. Leukemia 38, 1390–1402 (2024).

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