Programmed death 1 signaling on chronic myeloid leukemia-specific T cells results in T-cell exhaustion and disease progression.
Chronic myeloid leukemia (CML) is a malignant myeloproliferative disease with a characteristic chronic phase (cp) of several years before progression to blast crisis (bc). The immune system may contribute to disease control in CML. We analyzed leukemia-specific immune responses in cpCML and bcCML in a retroviral-induced murine CML model. In the presence of cpCML and bcCML expressing the glycoprotein of lymphocytic choriomeningitis virus as a model leukemia antigen, leukemia-specific cytotoxic T lymphocytes (CTLs) became exhausted. They maintained only limited cytotoxic activity, and did not produce interferon-gamma or tumor necrosis factor-alpha or expand after restimulation. CML-specific CTLs were characterized by high expression of programmed death 1 (PD-1), whereas CML cells expressed PD-ligand 1 (PD-L1). Blocking the PD-1/PD-L1 interaction by generating bcCML in PD-1-deficient mice or by repetitive administration of alphaPD-L1 antibody prolonged survival. In addition, we found that PD-1 is up-regulated on CD8(+) T cells from CML patients. Taken together, our results suggest that blocking the PD-1/PD-L1 interaction may restore the function of CML-specific CTLs and may represent a novel therapeutic approach for CML.
Tumor Immunology, Department of Clinical Research, University of Berne, Berne, Switzerland.
Sabine
S
Mumprecht
Christian
C
Schürch
Juerg
J
Schwaller
Max
M
Solenthaler
Adrian F
AF
Ochsenbein
D000328:Adult; D000818:Animals; D000954:Antigens, Surface / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002478:Cells, Cultured; D018450:Disease Progression; D005260:Female; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000235:genetics* / Q000276:immunology* / Q000473:pathology; D018655:Lymphocyte Count; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008875:Middle Aged; D008954:Models, Biological; D061026:Programmed Cell Death 1 Receptor; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology; D013601:T-Lymphocytes / Q000473:pathology*
D000954:Antigens, Surface; D051017:Apoptosis Regulatory Proteins; C491383:Pdcd1 protein, mouse; D061026:Programmed Cell Death 1 Receptor