Chronic viral infections are characterized by a state of CD8 T cell dysfunction termed exhaustion. A better understanding of the mechanisms that regulate CD8 T cell responses during chronic infection is required to improve immunotherapies that restore function in exhausted CD8 T cells. Here we identify a novel population of virus-specific CD8 T cells with a T follicular helper (Tfh)-like signature in mice chronically infected with lymphocytic choriomeningitis virus (LCMV). These Tfh-like CD8 T cells expressed the programmed cell death-1 (PD-1) inhibitory receptor but at the same time also expressed co-stimulatory molecules and had a gene signature that was related to CD8 T cell memory precursor cells and hematopoietic stem cells (HSC). These Tfh-like CD8 T cells acted as stem cells during chronic infection undergoing self-renewal and also differentiating into the terminally exhausted CD8 T cells that were present in both lymphoid and non-lymphoid tissues. The Tfh-like CD8 T cells were found only in lymphoid tissues and resided predominantly in the T cell zones along with nave CD8 T cells. Interestingly, the proliferative burst after PD-1 blockade came almost exclusively from this Tfh-like CD8 T cell subset. Importantly, the transcription factor TCF1 played a cell intrinsic and essential role in the generation of Tfh-like CD8 T cells. Taken together, our study identifies Tfh-like CD8 T cells as the critical subset for maintaining the pool of virus-specific CD8 T cells during chronic infection and as the cells that proliferate after PD-1 blockade. These findings provide a better understanding of T cell exhaustion and have implications towards optimizing PD-1 directed immunotherapy.
Defining CD8+ T cells that provide the proliferative burst after PD-1 therapy.
Sex, Specimen part, Time
View SamplesToxoplasma gondii is a ubiquitous apicomplexan parasite of mammals and birds and an important pathogen of humans. IFN-g is the major mediator of host resistance against T. gondii but intriguingly, parasite-infected host cells including macrophages are severely impaired to respond to IFN-g due to defective transcriptional activation of target genes. Here, we tested the possibility that the impaired responsiveness of T. gondii-infected macrophages to IFN-g can be restored by inhibiting histone deacetylases (HDACs) using the class I-specific inhibitor MS-275. Treatment of RAW264.7 cells with MS-275 indeed increased MHC class II surface expression in infected and non-infected cells and largely abolished the inhibition of IFN-g-regulated MHC class II expression exerted by T. gondii. Genome-wide transcriptome profiling revealed that MS-275 increased mean mRNA levels of IFN-g-regulated genes particularly in non-infected macrophages. Transcript levels of 33% of IFN-g secondary response genes but only those of a few primary response genes were also increased by MS-275 in T. gondii-infected cells. Importantly, the unresponsiveness of parasite-infected cells to IFN-g was however not abolished by MS-275. Furthermore, MS-275 also up-regulated several anti-inflammatory cytokines or signaling molecules in T. gondii-infected macrophages. It additionally regulated expression of more than 2500 genes in non-infected macrophages expression of which was surprisingly counteracted by prior infection with T. gondii. FACS analysis and immunofluorescence microscopy revealed that MS-275 did not considerably diminish the number of parasite-positive cells or the intracellular replication in macrophages stimulated or not with IFN-g. Thus, a supportive therapy using MS-275 appears inappropriate for treatment of toxoplasmosis. Overall design: High throughput RNA profiles from IFN-g-activated monocytic cells infected with Toxoplasma gondii and treated with MS-275 and control cells were generated by Illumina sequencing. Five experimental conditions with 2 biological replicates each were analysed.
Histone deacetylase inhibitor MS-275 augments expression of a subset of IFN-γ-regulated genes in Toxoplasma gondii-infected macrophages but does not improve parasite control.
Subject
View SamplesWe investigated the influence of SCFAs on human, monocyte derived DCs that represent a reliable in vitro model to study circulating DCs, one of the key regulators of our immune system. We studied the individual effect exerted by SCFA, the main metabolic end-products of fermentation by anaerobic bacteria in the gut, on the gene expression of immature and mature DC, exploring the potential of circulating bacterial metabolites to directly influence immune system cells. We found that SCFAs have little effect on the transcriptome of immature DC, whereas the transcriptome of mature DC was highly perturbed especially by butyrate and propionate. Our findings show an overall down-regulation of LPS-induced inflammatory responses and provide new insights into host-microbiome interactions.
The effect of short-chain fatty acids on human monocyte-derived dendritic cells.
Specimen part, Treatment
View SamplesStatus Epilepticus (SE) is an abnormally prolonged seizure that results from either a failure of mechanisms that terminate seizures or from initiating mechanisms that inherently lead to prolonged seizures.
Induction of Type 2 Iodothyronine Deiodinase After Status Epilepticus Modifies Hippocampal Gene Expression in Male Mice.
Specimen part
View SamplesBacterial genotoxins, produced by several Gram-negative bacteria, induce DNA damage in the target cells. While the responses induced in the host cells have been extensively studied in vitro, the role of the genotoxins as effectors during the course of acute and chronic infections remains poorly characterized.To address this issue, we assessed the effects of the Salmonella enterica genotoxin, known as typhoid toxin, in in vivo models of murine chronic infections. Immunocompetent mice were chronically infected with isogenic S. enterica, serovar Typhimurium (S. Typhimurium) strains, encoding either a functional (MC71-TT) or an inactive (MC71-DcdtB) typhoid toxin.
The Typhoid Toxin Promotes Host Survival and the Establishment of a Persistent Asymptomatic Infection.
No sample metadata fields
View SamplesFusarium head blight (FHB) is a major disease of cereal crops caused by the fungus Fusarium graminearum (Fg). FHB affects the flowering heads (or spikes) and developing seeds. This study compare the gene expression profile in wheat spikelets (spk 2) inoculated with either water (mock treatment) or a pathogenic strain of Fusarium graminearum (WT); spikelets 2 were inoculated 24 hrs after a neighbour spikelet (spk 0) was treated with either water or F. graminerum mutant strain Tri6 or NoxAB. Spikelets 2 were sampled 8 and 24 hrs after the second treatment.
Components of priming-induced resistance to Fusarium head blight in wheat revealed by two distinct mutants of Fusarium graminearum.
Specimen part
View SamplesThe metabolic syndrome (MetS) is characterized by the presence of metabolic abnormalities that include abdominal obesity, dyslipidemia, hypertension, increased blood glucose/insulin resistance, hypertriglyceridemia and increased risk for cardiovascular disease (CVD). The ApoE*3Leiden.human Cholesteryl Ester Transfer Protein (ApoE3L.CETP) mouse model manifests several features of the MetS upon high fat diet (HFD) feeding. Moreover, the physiological changes in the white adipose tissue (WAT) contribute to MetS comorbidities. The aim of this study was to identify transcriptomic signatures in the gonadal WAT of ApoE3L.CETP mice in discrete stages of diet-induced MetS.
Transcriptome analysis of the adipose tissue in a mouse model of metabolic syndrome identifies gene signatures related to disease pathogenesis.
Sex, Age, Specimen part
View SamplesMalformations of cortical development are the underlying eitiology of many cases of Mental Retardation and Epilepsy. Subtle, below the resolution of current MRI, cortical dysplasias are probably involved in many cases of MR, Epilepsy and Autism for which no diagnosis can currently be made. Therefore, understanding the process of cortical development will be vital in diagnosing and eventual treatment of many patients with these conditions. More specifically, the cortex forms from two major populations of neuroblasts which reach their final destination in the cortex by differerent mechanisms. One is radial migration from ventricular neuroblasts to the cortical plate. These cells are excititory projection neurons and glia. The second pathway is from the ventral ganglionic eminences and tangential migration of the interneuronal population of primarily inhibitory neurons. Much less is known about the control of the latter process, and many of these currently undiagnosed subtle malformations may stem from abnormalities of this tangential migration. This project focuses on the understanding the control of the tangentially migrating inhibitory interneurons.
Identification of Arx transcriptional targets in the developing basal forebrain.
No sample metadata fields
View SamplesArx is a paired-box homeodomain transcription factor and the vertebrate ortholog to the Drosophila aristaless (al) gene. Mutations in Arx are associated with a variety of human diseases, including X-linked infantile spasm syndrome (OMIM: 308350), X-linked myoclonic epilepsy with mental retardation and spasticity (OMIM: 300432), X-linked lissencephaly with ambiguous genitalia (OMIM: 300215), X-linked mental retardation 54 (OMIM: 300419), and agenesis of the corpus callosum with abnormal genitalia (OMIM: 300004). Arx-deficient mice exhibit a complex, pleiotrophic phenotype, including decreased proliferation of neuroepithelial cells of the cortex, dysgenesis of the thalamus and olfactory bulbs, and abnormal nonradial migration of GABAergic interneurons. It has been suggested that deficits in interneuron specification, migration, or function lead to loss of inhibitory neurotransmission, which then fails to control excitatory activity and leads to epilepsy or spasticities. Given that Arx mutations are associated with developmental disorders in which epilepsy and spasticity predominate and that Arx-deficient mice exhibit deficits in interneuron migration, understanding the function of Arx in interneuron migration will prove crucial to understanding the pathology underlying interneuronopathies. Yet, downstream transcriptional targets of Arx, to date, remain unidentified.
Identification of Arx transcriptional targets in the developing basal forebrain.
No sample metadata fields
View SamplesChronic cold exposure causes white adipose tissue (WAT) to adopt features of brown adipose tissue, a process known as browning. Previous studies have hinted at a possible role for the transcription factor Peroxisome Proliferator-Activated Receptor alpha (PPAR) in cold-induced browning. Here we aimed to investigate the importance of PPAR in driving transcriptional changes during cold-induced browning in mice. Male wildtype and PPAR/ mice were housed at thermoneutrality (28 C) or cold (5 C) for 10 days. Whole genome expression analysis was performed on inguinal WAT. In addition, other analyses were carried out. Whole genome expression data of livers of wildtype and PPAR/ mice fasted for 24 h served as positive control for PPAR-dependent gene regulation.Cold exposure increased food intake and decreased weight of BAT and WAT to a similar extent in wildtype and PPAR/ mice. Except for plasma non-esterified fatty acids, none of the cold-induced changes in plasma metabolites were dependent on PPAR genotype. Histological analysis of inguinal WAT showed clear browning upon cold exposure but did not reveal any morphological differences between wildtype and PPAR/ mice. Transcriptomics analysis of inguinal WAT showed a marked effect of cold on overall gene expression, as revealed by principle component analysis and hierarchical clustering. However, wildtype and PPAR/ mice clustered together, even after cold exposure, indicating a similar overall gene expression profile in the two genotypes. Pathway analysis revealed that cold upregulated pathways involved in energy usage, oxidative phosphorylation, and fatty acid -oxidation to a similar extent in wildtype and PPAR/ mice. Furthermore, cold-mediated induction of genes related to thermogenesis such as Ucp1, Elovl3, Cox7a1, Cox8, and Cidea, as well as many PPAR target genes, was similar in wildtype and PPAR/ mice. Finally, pharmacological PPAR activation had a minimal effect on expression of cold-induced genes in murine WAT.Cold-induced changes in gene expression in inguinal WAT are unaltered in mice lacking PPAR, indicating that PPAR is dispensable for cold-induced browning.
The Peroxisome Proliferator-Activated Receptor α is dispensable for cold-induced adipose tissue browning in mice.
Sex
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