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Sitnicka, E.

Publications and source records attributed to Sitnicka, E..

2 recordsLinked to original sources

NK cells control the progression of myelodysplastic syndrome but become initial disease target in NUP98-HOXD13 mouse model

Studies in NUP98/HOXD13 mouse model (NHD13tg), progressing from myelodysplastic syndrome (MDS) to different forms of leukemia, demonstrated that T cells had a limited anti-leukemia effect, suggesting the involvement of other immune cells. Natural killer (NK) cells control viral infection and cancer. In MDS and acute myeloid leukemia (AML), patients often acquire disease-induced NK cell dysfunctions. Here, we report that NK cells from NHD13tg mice were reduced before the MDS-onset and specific NK cell depletion accelerated the disease progression and severity. NK cells from NHD13tg mice showed perturbed differentiation and impaired IL-15/IL-2 responses. These defects were cell-intrinsic and mainly affected the KLRG1+ mature NK cells. The expression of Nfil3, Klf2 and Id2 genes, crucial for NK cell development, homeostasis and IL-15 responsiveness, was altered in immature NK cells from NHD13tg mice. Interestingly, these genes were changed in MDS and AML bone marrow patient-samples compared to healthy donors. Our findings highlight a critical role for NK cells in controlling MDS progression and identify new genetic markers for MDS and AML.

immunology↗

Concurrent stem- and lineage-affiliated chromatin programs precede hematopoietic lineage restriction

The emerging notion of hematopoietic stem- and progenitor cells (HSPCs) as a low-primed cloud without sharply demarcated gene expression programs raises the question on how cellular fate options emerge, and at which stem-like stage lineage priming is initiated. Here we investigated single-cell chromatin accessibility of Lineage-, cKit+, Sca1+ (LSK) HSPCs spanning the early differentiation landscape. Application of a signal-processing algorithm to detect transition points corresponding to massive alterations in accessibility of 571 transcription factor-motifs revealed a population of LSK FMS-like tyrosine kinase 3(Flt3)intCD9high cells that concurrently display stem-like and lineage-affiliated chromatin signatures pointing to a simultaneous gain of both Lympho-Myeloid and Megakaryocyte-Erythroid programs. Molecularly and functionally, these cells position between stem cells and committed progenitors, display multi-lineage capacity in vitro and in vivo, but lack self-renewal activity. This integrative molecular analysis resolves the heterogeneity of cells along hematopoietic differentiation and permits investigation of chromatin-mediated transition between multipotency and lineage restriction.

cell biology↗