Dataset Information

Manipulating niche composition limits damage to haematopoietic stem cells during Plasmodium infection

ABSTRACT: Severe infections are a major stress on haematopoiesis, where the consequences for haematopoietic stem cells (HSCs) have only recently started to emerge. HSC function critically depends on the integrity of complex bone marrow (BM) niches, however whether the BM microenvironment plays a role in mediating the effects of infection on HSCs remains an open question. Here, using a murine model of malaria and combining single cell RNA sequencing, mathematical modelling, transplantation assays and intravital microscopy, we show that haematopoiesis is reprogrammed upon infection, whereby the HSC compartment turns over significantly faster than in steady-state and HSC function is drastically affected as a result. Interferon is found to affect both haematopoietic and mesenchymal BM cells and we specifically identify a dramatic loss of osteoblasts and alterations in endothelial cell function. Osteo-active parathyroid hormone treatment abolishes infection-triggered HSC proliferation and, coupled with Reactive Oxygen Species quenching, enables partial rescuing of HSC function.

ORGANISM(S): Mus musculus

PROVIDER: GSE156410 | GEO | 2020/09/10

REPOSITORIES: GEO

ACCESS DATA

Shared Molecules

Only show the datasets with similarity scores above: 0.5

Threshold

0.5

Similar Datasets

Project description:Adult haematopoietic stem cells (HSCs) are responsible for the lifelong production of blood and immune cells and must respond to extracellular cues including cytokines. The JAK/STAT pathway is a highly conserved pathway, activated by many cytokines, in which tyrosine-phosphorylated STATs (pSTATs) function as transcription factors. STAT5 is a pivotal downstream mediator of several cytokines known to regulate haematopoiesis but its function in the HSC compartment remains poorly understood. Here we show that STAT5-deficient HSCs exhibited an unusual phenotype - reduced multi-lineage repopulation and self-renewal combined with reduced cell cycle entry and increased differentiation. This reflected not only loss of a canonical pSTAT5 transcriptional program but also loss of distinct functions mediated by tyrosine-unphosphorylated STAT5 (uSTAT5). Consistent with this concept expression of an unphosphorylatable STAT5B mutant constrained HSC differentiation, promoted HSC maintenance and upregulated transcriptional programs associated with quiescence and stemness. Moreover, treatment with a JAK1/2 inhibitor (ruxolitinib) increased the uSTAT5:pSTAT5 ratio, constrained HSC differentiation and proliferation and promoted HSC maintenance, thus phenocopying uSTAT5B overexpression. Our results therefore reveal a previously unrecognized interplay between pSTAT5 and uSTAT5 in the control of HSC function. In addition the demonstration that JAK inhibition promotes HSC maintenance has implications for gene therapy using HSCs and may contribute to the failure of JAK inhibitors to eradicate myeloproliferative neoplasms. To evaluate the long-term functional capacity of uSTAT5B overexpressing HSCs, WT CD45.2 ESLAM HSCs were sorted and transduced with lentivirus containing STAT5B-YF, STAT5B-WT and EV in SCF and IL-11 cultures. Five days after infection, cells were sorted for viability (DAPI-, Thermo Fisher) and green fluorescent protein (GFP) expression and processed according to the manufacturer’s protocol for 10x Chromium (10x Genomics, Pleasanton, CA) experiments .