Haematologica (Feb 2021)

Loss of interleukin-10 activates innate immunity to eradicate adult T-cell leukemia-initiating cells

  • Hiba El Hajj,
  • Rita Hleihel,
  • Marwan El Sabban,
  • Julie Bruneau,
  • Ghazi Zaatari,
  • Morgane Cheminant,
  • Ambroise Marçais,
  • Abdou Akkouche,
  • Hideki Hasegawa,
  • William Hall,
  • Hugues De Thé,
  • Olivier Hermine,
  • Ali Bazarbachi

DOI
https://doi.org/10.3324/haematol.2020.264523
Journal volume & issue
Vol. 106, no. 5

Abstract

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Adult T cell leukemia/lymphoma (ATL) is associated to chronic human T cell leukemia virus type 1 (HTLV-1) infection and carries a poor prognosis. Arsenic trioxide (AS) and interferon-alpha (IFNα) together selectively trigger Tax viral oncoprotein degradation and cure Tax-driven murine ATL. AS/IFNα/zidovudine treatment achieves a high response rate in patients with chronic ATL. Interleukin 10 (IL-10) is an immuno-suppressive cytokine whose expression is activated by Tax. Here we show that, in ATL, AS/IFNα-induced abrogation of leukemia initiating cell activity requires IL-10 expression shutoff. Loss of IL-10 secretion drives production of inflammatory cytokines by the microenvironment, followed by innate immunity-mediated clearance of Taxdriven leukemic cells. Accordingly, anti-IL-10 monoclonal antibodies significantly increased the efficiency of AS/IFNα therapy. These results emphasize the sequential targeting of malignant ATL cells and their immune microenvironment in leukemia initiating cell (LIC) eradication and provide a strong rational to test AS/IFNα/anti-IL10 combination in ATL.