Although mast cells elicit proinflammatory and type I IFN responses upon VSV infection, in response to L.monocytogenes (L.m) or S. Typhimurium (S.t), such cells elicit a transcriptional program devoid of type I IFN response.
Mast cells elicit proinflammatory but not type I interferon responses upon activation of TLRs by bacteria.
Specimen part
View SamplesBackground: Influenza A virus (IAV) infections periodically cause substantial morbidity and mortality in the human population. In the lung, the primary targets for IAV replication are type II alveolar epithelial cells (AECII), which are increasingly recognized for their immunological potential. However, our knowledge of the role of AECII in anti-IAV immunity is incomplete and their in vivo response to infection has not been evaluated. To increase our understanding of their role in host-response to IAV-infection, we analyzed transcriptional regulation in primary AECII isolated from infected mice. Results: Microarray analyses of AECII isolated on the first three days following IAV-infection revealed extensive transcriptional regulation. A multitude of differentially expressed transcripts was identified and in comparison to whole-lung tissue revealed a strong contribution of AECII to respiratory anti-IAV responses. Type I interferon played a major role in the detected gene expression profile and functional pathway analyses showed AECII to be highly active in pathogen recognition, cell recruitment and antigen-presentation. Analysis of Toll-like receptor 7 (TLR7) deficient mice indicated AECII to rely on the hosts expression of this innate IAV-sensor to elicit their full response. Importantly, the AECII transcriptional profiles correlated to cell recruitment and type I interferon levels detected in the lungs of infected animals. Conclusions: Ex vivo analysis of primary murine AECII proved as a powerful tool to increase our understanding of AECII biology in infection. Our analysis revealed an exceptionally strong contribution of AECII to local host defenses by integrating signals provided by surrounding cells and direct pathogen recognition.
Alveolar Type II Epithelial Cells Contribute to the Anti-Influenza A Virus Response in the Lung by Integrating Pathogen- and Microenvironment-Derived Signals.
Treatment
View SamplesInterferons have been ascribed to mediate antitumor effects. IRF-1 is a major target gene of interferons. It inhibits cell proliferation and oncogenic transformation. Here we show that 60% of all mRNAs deregulated by oncogenic transformation mediated by c-myc and H-ras are reverted to the expression levels of non-transformed cells by IRF-1. These include cell cycle regulating genes. Activation of IRF-1 decreases cyclin D1 expression and CDK4 kinase activity concomitant with dephosphorylation of pRb. These effects of IRF-1 are mediated by inhibition of the MEK-ERK pathway and a transcriptional repression of cyclin D1. IRF-1 mediated effects on cell cycle progression were found to be overridden by ectopic expression of cyclin D1. Ablation of cyclin D1 by RNA interference experiments prevents transformation and tumor growth in nude mice. The data demonstrate that cyclin D1 is a key target for IRF-1 mediated tumor suppressive effects.
Tumor suppression by IFN regulatory factor-1 is mediated by transcriptional down-regulation of cyclin D1.
Specimen part
View SamplesUsing the recently described CD104+/CD44hi antigen combination we demonstrate that tumorigenicity depends on individual cells residing in a hybrid E/M state. Acquisition of this E/M hybrid state is facilitated by the differential expression of EMT- TFs, like Snail accompanied by the expression of adult stem-cell programs. Transition from the highly tumorigenic E/M state to a fully mesenchymal phenotype, achieved by constitutive ectopic expression of Zeb1, is sufficient to drive cells out of the E/M hybrid state into an extreme mesenchymal (xM) state, which is accompanied by a substantial loss of tumorigenicity and a switch from canonical to non-canonical Wnt signaling. Overall design: Performing RNASeq with HMLE (immortalized human mammary epithelial cells) in different EMT stages, either in the E state the hybrid E/M state or the extreme mesenchymal (xM) state as determined by sorting for CD104 and CD44. And performing RNASeq with HMLE cells locked in the xE state by Zeb1KO (xE-SCC-Zeb1KO), from there transferred to the hybrid E/M state by Snail overexpression (E-SCC-Zeb1KOSn) or rescued and transitioned to an xM state with CRISPR resistant Zeb1 wobble mutant (mt) (E-SCC-Zeb1KOSnZmt).
Acquisition of a hybrid E/M state is essential for tumorigenicity of basal breast cancer cells.
Specimen part, Subject
View SamplesGoals and objectives of this study: to identify genes preferentially induced in human CD4+CD25hi Treg cells following T-cell activation with potential role for stabililization & maintenance of the regulatory program.
GARP: a key receptor controlling FOXP3 in human regulatory T cells.
Specimen part
View SamplesGoals and objectives of this study: to identify genes of the Treg signature induced by consitutive expression of GARP or FOXP3 in antigen-specific Th cells with potential role for stabililization & maintenance of the regulatory program.
GARP: a key receptor controlling FOXP3 in human regulatory T cells.
Specimen part
View SamplesMyeloid dendritic cells (DC) and macrophages play an important role in pathogen sensing and antimicrobial defense. Recently we demonstrated that infection of human DC with intracellular bacterium Listeria monocytogenes (L.monocytogenes) leads to the induction of the immunoinhibitory enzyme indoleamine 2,3-dioxygenase (Popov et al., J Clin Invest, 2006), while in the previous studies L.monocytogenes infection was associated with a rather stimulatory DC phenotype. To clarify this discrepancy we performed comparative microarray analysis of immature mo-DC (immDC), mature stimulatory mo-DC (matDC) and mature inhibitory DC either stimulated with prostaglandin E2 (PGE2-DC) or infected with L.monocytogenes (infDC). Studying infection of human myeloid DC with Listeria monocytogenes, we found out, that infected DC are modified by the pathogen to express multiple inhibitory molecules, including indoleamine 2,3-dioxygenase (IDO), cyclooxygenase-2, interleukin 10 and CD25, which acts on DC as IL-2 scavenger. All these inhibitory molecules, expressed on regulatory DC (DCreg), are strictly TNF-dependent and are in concert suppressing T-cell responses. Moreover, only DCreg can efficiently control the number of intracellular listeria, mostly by IDO-mediated mechanisms and by other factors, remaining to be identified. Analyzing publicly acessible data of transcriptional changes in DC and macrophages, infected by various pathogens and parasites (GEO, GSE360), we noticed that infection of these cells with Mycobacterium tuberculosis causes transcriptional response, comparable with the one caused by listeria in human DC. In fact, granuloma in tuberculosis and listeriosis in vivo are enriched for myeloid DC and macrophages characterized by regulatory phenotype.
Infection of myeloid dendritic cells with Listeria monocytogenes leads to the suppression of T cell function by multiple inhibitory mechanisms.
No sample metadata fields
View SamplesGene expression in NPM1 wildtype and mutated AML patients with high or low hsa_circ_0075001 expression
Circular RNAs of the nucleophosmin (NPM1) gene in acute myeloid leukemia.
Specimen part, Disease, Disease stage
View SamplesAcute myeloid leukemia (AML) is characterized by molecular heterogeneity. As commonly altered genomic regions point to candidate genes involved in leukemogenesis, we used microarray-based comparative genomic hybridization and single nucleotide polymorphism profiling data of 391 AML cases to further narrow down genomic regions of interest. Targeted-resequencing of 1000 genes located in the critical regions was performed in a representative cohort of 50 AML samples comprising all major cytogenetic subgroups. We identified 120 missense/nonsense mutations as well as 60 insertions/deletions affecting 73 different genes (~3.6 tumor-specific aberrations/AML). While most of the newly identified alterations were non-recurrent, we observed a number of mutations affecting genes involved in epigenetic regulation including known candidates like TET2, TET1, DNMT3A and DNMT1, as well as mutations in the histone methyltransferases NSD1, EZH2 and MLL3. Furthermore, we found mutations in the splicing factor SFPQ and in the non-classical regulators of mRNA-processing CTCF and RAD21. These splicing-related mutations affected 10% of AML patients in a mutually exclusive manner. In conclusion, we could identify a significant enrichment of alterations in genes involved in aberrant splicing and epigenetic regulation in genomic regions commonly altered in AML, highlighting their important role in the molecular pathogenesis of AML.
Commonly altered genomic regions in acute myeloid leukemia are enriched for somatic mutations involved in chromatin remodeling and splicing.
Specimen part, Disease
View SamplesPatients relapsing with FLT3-ITD mutant acute myeloid leukemia (AML) after allogeneic hematopoietic cell transplantation (allo-HCT) have a one-year-survival below 20%. We observed that sorafenib increased IL-15 production by FLT3-ITD+-leukemia cells, which synergized with the allogeneic CD8+T-cell response, leading to long-term survival in murine and humanized FLT3-ITD+AML models. Using IL-15 deficiency in recipient tissues or leukemia cells, IL-15 production upon sorafenib-treatment could be attributed to leukemia cells. Sorafenib treatment-related IL-15 production caused an increase in CD8+CD107a+IFN-+ T-cells with features of longevity (Bcl-2high/reduced PD-1-levels), which eradicated leukemia in secondary recipients. Mechanistically, sorafenib reduced ATF4 expression, thereby blocking negative regulation of IRF7-activation, which enhances IL-15 transcription. Consistent with the mouse data, IL-15 and pIRF7 levels increased in leukemic blasts of FLT3-ITD+AML patients upon sorafenib treatment. Analysis of 130 patients with FLT3-ITD-mutant AML relapsing after allo-HCT showed the highest complete remission-rate and median overall-survival-rate in the sorafenib/donor lymphocyte infusion (DLI) group compared to all other groups (chemotherapy, chemotherapy/DLI, sorafenib alone). Our findings indicate that the synergism of DLI and sorafenib is mediated via reduced ATF4 expression, causing activation of the pIRF7/IL-15-axis in leukemia cells. The sorafenib/DLI strategy therefore has the potential for an immune-mediated cure of FLT3-ITD-mutant AML- relapse, an otherwise fatal complication after allo-HCT.
Sorafenib promotes graft-versus-leukemia activity in mice and humans through IL-15 production in FLT3-ITD-mutant leukemia cells.
Specimen part, Treatment, Time
View Samples