Microbial signals drive pre-leukaemic myeloproliferation in a Tet2-deficient host.
Nature 2018;
557:580-584. [PMID:
29769727 PMCID:
PMC6238954 DOI:
10.1038/s41586-018-0125-z]
[Citation(s) in RCA: 254] [Impact Index Per Article: 42.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 04/17/2018] [Indexed: 01/17/2023]
Abstract
Somatic mutations in tet methylcytosine dioxygenase 2 (TET2), which encodes an epigenetic modifier enzyme, drive the development of haematopoietic malignancies1-7. In both humans and mice, TET2 deficiency leads to increased self-renewal of haematopoietic stem cells with a net developmental bias towards the myeloid lineage1,4,8,9. However, pre-leukaemic myeloproliferation (PMP) occurs in only a fraction of Tet2-/- mice8,9 and humans with TET2 mutations1,3,5-7, suggesting that extrinsic non-cell-autonomous factors are required for disease onset. Here we show that bacterial translocation and increased interleukin-6 production, resulting from dysfunction of the small-intestinal barrier, are critical for the development of PMP in mice that lack Tet2 expression in haematopoietic cells. Furthermore, in symptom-free Tet2-/- mice, PMP can be induced by disrupting intestinal barrier integrity, or in response to systemic bacterial stimuli such as the toll-like receptor 2 agonist. PMP was reversed by antibiotic treatment and failed to develop in germ-free Tet2-/- mice, which illustrates the importance of microbial signals in the development of this condition. Our findings demonstrate the requirement for microbial-dependent inflammation in the development of PMP and provide a mechanistic basis for the variation in PMP penetrance observed in Tet2-/- mice. This study will prompt new lines of investigation that may profoundly affect the prevention and management of haematopoietic malignancies.
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