RIG-I-based immunotherapy enhances survival in preclinical AML models and sensitizes AML cells to checkpoint blockade

Leukemia. 2020 Apr;34(4):1017-1026. doi: 10.1038/s41375-019-0639-x. Epub 2019 Nov 18.

Abstract

Retinoic acid-inducible gene-I (RIG-I) is a cytoplasmic immune receptor sensing viral RNA. It triggers the release of type I interferons (IFN) and proinflammatory cytokines inducing an adaptive cellular immune response. We investigated the therapeutic potential of systemic RIG-I activation by short 5'-triphosphate-modified RNA (ppp-RNA) for the treatment of acute myeloid leukemia (AML) in the syngeneic murine C1498 AML tumor model. ppp-RNA treatment significantly reduced tumor burden, delayed disease onset and led to complete remission including immunological memory formation in a substantial proportion of animals. Therapy-induced tumor rejection was dependent on CD4+ and CD8+ T cells, but not on NK or B cells, and relied on intact IFN and mitochondrial antiviral signaling protein (MAVS) signaling in the host. Interestingly, ppp-RNA treatment induced programmed death ligand 1 (PD-L1) expression on AML cells and established therapeutic sensitivity to anti-PD-1 checkpoint blockade in vivo. In immune-reconstituted humanized mice, ppp-RNA treatment reduced the number of patient-derived xenografted (PDX) AML cells in blood and bone marrow while concomitantly enhancing CD3+ T cell counts in the respective tissues. Due to its ability to establish a state of full remission and immunological memory, our findings show that ppp-RNA treatment is a promising strategy for the immunotherapy of AML.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / immunology
  • Animals
  • Antibodies, Neutralizing / pharmacology*
  • B7-H1 Antigen / antagonists & inhibitors
  • B7-H1 Antigen / genetics
  • B7-H1 Antigen / immunology
  • CD4-Positive T-Lymphocytes / drug effects
  • CD4-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / drug effects
  • CD8-Positive T-Lymphocytes / immunology
  • DEAD Box Protein 58 / genetics
  • DEAD Box Protein 58 / immunology*
  • Disease Models, Animal
  • Drug Evaluation, Preclinical
  • Gene Expression Regulation
  • Heterografts
  • Humans
  • Immunologic Memory / drug effects
  • Immunotherapy / methods*
  • Interferons / genetics
  • Interferons / immunology
  • Isografts
  • Leukemia, Myeloid, Acute / genetics
  • Leukemia, Myeloid, Acute / immunology
  • Leukemia, Myeloid, Acute / mortality
  • Leukemia, Myeloid, Acute / therapy*
  • Mice
  • RNA, Double-Stranded / pharmacology*
  • Receptors, Virus / agonists
  • Receptors, Virus / genetics
  • Receptors, Virus / immunology*
  • Remission Induction
  • Signal Transduction
  • Survival Analysis
  • Treatment Outcome

Substances

  • Adaptor Proteins, Signal Transducing
  • Antibodies, Neutralizing
  • B7-H1 Antigen
  • Cd274 protein, mouse
  • IPS-1 protein, mouse
  • RNA, Double-Stranded
  • Receptors, Virus
  • Interferons
  • Ddx58 protein, mouse
  • DEAD Box Protein 58