Project description:Aggressive systemic mastocytosis with associated hematologic neoplasm (ASM-AHN) represents a complex myeloid neoplasm, in which KIT D816V is the phenotype-defining but not the only driver mutation. Avapritinib is a potent and specific KIT D816V inhibitor recently approved for ASM treatment. To understand the effects of inhibiting KIT D816V on MC and Non-MC compartments, we combined single cell RNA sequencing (scRNAseq) with deep whole genome sequencing (WGS) to map clonal dynamics in successive blood samples from 4 ASM-AHN patients treated with avapritinib (T1 as pretreatment sample, T2 and T3 as posttreatment samples). Since CMML is the most common AHN associated with ASM, we included samples from three treatment-naïve KIT wild type CMML patients for comparison. We also included 3 age-matched healthy donor as controls.
Project description:RNA-seq of bone marrow samples of chronic myelomonocytic leukemia (CMML) patients and healthy donors to identify the molecular DNA repair pathways involved in CMML pathogenic
Project description:Interleukin (IL)-17 plays an important and protective role in host defence and has been demonstrated to orchestrate airway inflammation by cooperating with and inducing proinflammatory cytokines. Mircoarrays were used to identify immediate-early/ primary response IL-17A-dependent gene transcripts in primary human bronchial ASM cells from mild asthmatic and healthy individuals. To evaluate IL-17A-inducible gene transcripts, primary human bronchial ASM cells from 3 mild asthmatic and 3 healthy donors were treated for 2h with IL-17 [10ng/ml] and were probed with the Affymetrix GeneChip array. The 2h time point was carefully chosen in order to identify primary response gene targets and to avoid confounding autocrine mechanisms mediating indirect, or late-phase gene expression responses. Non-stimulated ASM cells from the same patients were used as controls.
Project description:Chronic myelomonocytic leukemia (CMML) is a clonal malignancy characterized by overlapping myeloid dysplasia and proliferation with persisting monocytosis. Characteristic repartitioning of classical monocytes is now a supporting diagnostic criterion (WHO5), though its mechanistic basis remains unknown. While monocytes are the cardinal malignant cell type in CMML, as a stem cell neoplasm the disease clone comprises most lineages and differentiation stages including granulocytes. To investigate the pathogenic contribution of granulocytes in CMML maintenance and progression, we have performed molecular and functional characterization of CMML granulocytes. Compared with healthy age-matched controls, CMML granulocytes exhibited defective maturation with reduced granularity and phagocytic capacity. Transcriptome analysis revealed activation of pathways linked to proliferation, Myc activity and inflammation. Notably, RETN, which encodes inflammatory mediator Resistin, was upregulated 100-fold in CMML granulocytes; but not differentially expressed in CMML PBMNCs, sorted monocytes, or stem and progenitor cells compared to their healthy counterparts. Accordingly, Resistin protein levels were 10-fold higher in plasma from CMML patients and higher plasma Resistin levels correlate with poor overall survival. Remarkably, exposure of healthy monocytes to exogenous recombinant Resistin induced classical monocyte repartition, recapitulating the pattern seen in CMML, and inhibited macrophage differentiation. Transcriptome analysis of Resistin treated monocytes revealed that Resistin induces gene signatures related to immune suppression and myeloid-derived suppressor cell phenotype. We found SEMA4A to be a downstream target of Resisin and is overexpressed in CMML monocytes. Consistent with known roles for SEMA4A, CMML patients displayed higher percentage of T-regs and elevated Th2/Th1 ratio compared with healthy controls, apparently corresponding with associated Resistin levels. Furthermore, we demonstrated that Resistin directly induces the T-reg expansion and skews the Th2/Th1 ratio by binding to monocytes. In conclusion, we showed that immature granulocytes in CMML produce high levels of Resistin, which contributes to classical monocytosis phenotype and immune suppression.
Project description:This study includes 2 cohorts of samples. First cohort consists out of BM aspirates from 4 healthy individuals and 12 patients diagnosed with AML, MDS or CMML. Second cohort includes 5 healthy individuals and 17 patients diagnosed with AML, MDS or CMML. MDS and CMML patients were treated with 5-AZA on 6 cycles and samples were obtained before the treatment and 15 days after 1 and 6 rounds of treatment.
Project description:Myeloblast expansion is a hallmark of disease progression in leukemias and comprises of CD34+ hematopoeitic stem and progeneitor cells. We used single-cell RNA sequencing (scRNAseq) to analyze the transcriptional states of HSPCs in CMML.