Expansions of tumor-reactive Vdelta1 gamma-delta T cells in newly diagnosed patients with chronic myeloid leukemia

Cancer Immunol Immunother. 2023 May;72(5):1209-1224. doi: 10.1007/s00262-022-03312-3. Epub 2022 Nov 14.


Recent studies have underscored the importance of gamma-delta (γδ) T cells in mediating potent MHC-unrestricted cytotoxicity in numerous malignancies. Here, we analyzed Vδ1 and Vδ2 γδ T cell subsets in newly diagnosed chronic myeloid leukemia (CML) patients (n = 40) who had initiated tyrosine kinase inhibitor (TKI) therapy including imatinib (n = 22), nilotinib (n = 14) and dasatinib (n = 4). Patient peripheral blood samples were analyzed at diagnosis and monitored prospectively at 3, 6, 12 and 18 months post-TKI. γδ T cells isolated from healthy donors and CML patients were used against K562, LAMA-84 and KYO-1 cell lines and against primary CML cells in cytotoxicity assays. We found large expansions of Vδ1 and Vδ2 T cells in patients at diagnosis compared to age-matched healthy donors (n = 40) (p < 0.0001). The γδ T cell reconstitution in patients on imatinib and also on nilotinib showed significant reductions of Vδ1 T cell and Vδ2 T cell absolute counts at 3 months compared to diagnosis. Importantly, Vδ1 and Vδ2 T absolute cell counts remained at normal levels from 3 months throughout the follow-up. Next, we observed susceptibility to specific lysis of primary CML tumor cells by Vδ1 T cells from healthy donors. Furthermore, we determined inherent cytotoxic reactivity by autologous patients' Vδ1 T lymphocytes against primary CML tumor cells. Finally, the TCR clonality profiles showed in CML patients mostly polyclonal repertoires regardless of the TKI. Our results provide further evidence into γδ T cell antileukemia immunity in CML that might be beneficial for long-term disease control and treatment outcome.

Keywords: Chronic myeloid leukemia; Clonality; Gamma-delta T cells; Tumor immunotherapy.

MeSH terms

  • Cell Line
  • Humans
  • Imatinib Mesylate / pharmacology
  • Imatinib Mesylate / therapeutic use
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive* / drug therapy
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive* / metabolism
  • Leukemia, Myeloid* / metabolism
  • Receptors, Antigen, T-Cell, gamma-delta / metabolism
  • T-Lymphocyte Subsets


  • Imatinib Mesylate
  • Receptors, Antigen, T-Cell, gamma-delta