Human Natural Killer (NK) cells comprise two main subsets, CD56bright and CD56dim cells, that differ in function, phenotype and tissue localization. To further dissect the heterogeneity of CD56dim cells, we have performed transcriptome analysis and functional ex vivo characterization of human NK cell subsets according to the expression of markers related to differentiation, migration or competence. Here, we show for the first time that the ability to respond to cytokines or to activating receptors is mutually exclusive in almost all NK cells with the exception of CD56dim CD62L+ cells. Indeed, only these cells combine the ability to produce interferon (IFN)-gamma after cytokines and proliferate in vivo during viral infection with the capacity to kill and produce cytokines upon engagement of activating receptors. Therefore, CD56dim CD62L+ cells represent a unique subset of polyfunctional NK cells. Ex vivo analysis of their function, phenotype, telomere length, frequencies during ageing as well as transfer experiments of NK cell subsets into immunodeficient mice suggest that CD56dim CD62L+ cells represent an intermediate stage of NK cell maturation, which after restimulation can accomplish multiple tasks and further develop into terminally differentiated effectors.
CD62L expression identifies a unique subset of polyfunctional CD56dim NK cells.
Specimen part
View SamplesIt is known that natural killer (NK) cells are a heterogeneous population of functionally distinct NK cell subsets. Here we report on different genomic, phenotypic and functional properties of human NK cell subsets derived from peripheral blood, thymus and bone marrow. NK cell subpopulations were defined via expression of CD56 and CD16.
Specific phenotype and function of CD56-expressing innate immune cell subsets in human thymus.
Specimen part
View SamplesRORt+ innate lymphoid cells (ILC) are crucial players of innate immune responses and represent a major source of IL-22, which has an important role in mucosal homeostasis. The signals required by RORt+ ILC to express IL-22 and other cytokines, including TNF, have only partially been elucidated. Here we show that RORt+ ILC can directly sense the environment by the engagement of the activating receptor NKp44. NKp44 triggering in RORt+ ILC selectively activates a coordinated pro-inflammatory program, including TNF, while cytokine stimulation induces preferentially IL-22 expression. However, combined engagement of NKp44 and cytokine receptors results in a strong synergistic effect. These data support the concept that NKp44+ RORt+ ILC can be activated without cytokines and are able to switch between IL-22 or TNF production, depending on the triggering stimulus.
RORγt⁺ innate lymphoid cells acquire a proinflammatory program upon engagement of the activating receptor NKp44.
Specimen part, Treatment
View SamplesTh17 cells were sorted ex vivo from PB of healthy donors as CD4+CD161+CCR6+CXCR3-. Following, cells were transduced with a lentiviral vector carrying the Eomes gene or with an empty vector. Infected cells were then enriched by MACS separation using the reporter gene NGFR as selection marker. Finally, cells were frozen for RNA analysis.
Eomes controls the development of Th17-derived (non-classic) Th1 cells during chronic inflammation.
Cell line
View SamplesIts characteristic rose-like aroma makes phenylethanol a popular ingredient in foods, beverages and cosmetics. Microbial production of phenylethanol currently relies on whole-cell bioconversion of phenylalanine with yeasts that harbor an Ehrlich pathway for phenylalanine catabolism. Complete biosynthesis of phenylethanol from a cheap carbon source such as glucose provides an economically attractive alternative for phenylalanine bioconversion. In this study, a Synthetic Genetic Array screening was applied to identify genes involved in regulation of phenylethanol synthesis in Saccharomyces cerevisiae. The screen focused on transcriptional regulation of ARO10, which encodes the major decarboxylase involved in conversion of phenylpyruvate to phenylethanol. A deletion in ARO8, which encodes an aromatic amino acid transaminase, was found to cause a transcriptional upregulation of ARO10 during growth with ammonium sulfate as the sole nitrogen source. Physiological characterization revealed that the aro8 mutation led to substantial changes in the absolute and relative intracellular concentrations of amino acids. Moreover, deletion of ARO8 led to de novo production of phenylethanol during growth on a glucose synthetic medium with ammonium as the sole nitrogen source. The aro8 mutation also stimulated phenylethanol production when combined with other, previously documented mutations that deregulate aromatic amino acid biosynthesis in S. cerevisiae. The resulting engineered S. cerevisiae strain produced over 3 mM of phenylethanol from glucose during growth on a simple synthetic medium. The strong impact of a transaminase deletion on intracellular amino acid concentrations opens new possibilities for yeast-based production of amino acid-derived products.
Deletion of the Saccharomyces cerevisiae ARO8 gene, encoding an aromatic amino acid transaminase, enhances phenylethanol production from glucose.
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View SamplesDespite the fact that clinically relevant infectious agents such as human immunodeficiency virus enter through the intestinal mucosa, the intestinal T cell response to infection remains understudied. Listeria monocytogenes (LM) has been used as a model organism for studying T cell responses and the normal route of infection for LM and a potential route for use of LM as a vaccine are through ingestion. Nevertheless, the vast majority of LM immunological studies utilize inoculation routes other than oral. Moreover in the bacterial strains used the internalin. A protein binds human E-cadherin with high affinity but poorly binds mouse E-cadherin. This receptor-ligand pairing is required for entry of LM into intestinal epithelial cells. The oral infection studies proposed here utilize a recombinant LM that expresses an internalin A protein with high affinity for mouse E-cadherin. Thus, the physiologic route and entry point of LM is recapitulated in our studies. Our preliminary studies revealed a remarkable mucosal TCR gd T cell response to oral LM infection, whose kinetics mimic an adaptive T cell response. Most importantly, this phenotypically and functionally distinct subset of mucosal TCR gd T cells are retained long-term and undergo a recall response upon challenge. The hypothesis to be tested in this proposal is that this specialized subset of putative memory TCR gd T cells is important for protection against LM infection and also regulates the long-term protective CD8 TCR ab response. This hypothesis will be tested in the following specific aims: Aim 1. To test whether a subset of TCR gd represent bona fide mucosal memory cells. A detailed kinetic, phenotypic and functional analysis of the primary and secondary TCR gd cell response to oral LM infection will be undertaken. Aim 2. To determine the requirements for mucosal TCRgd activation in response to LM infection. Here we will test the role of dendritic cells, cosfimulation and cytokines in mounting primary and secondary TCR gd cell responses. Aim 3. To visualize the mucosal TCR gd cell response to oral LM infection. The oral infection system provides an exceptional opportunity to examine the anatomy of the mucosal TCR gd cell response.
γδ T cells exhibit multifunctional and protective memory in intestinal tissues.
Sex, Age, Specimen part, Cell line
View SamplesThe oocytes of many species, both invertebrate and vertebrate, contain a large collection of localized determinants in the form of proteins and translationally inactive maternal mRNAs. However, it is unknown whether mouse oocytes contain localized MmRNA determinants and what mechanisms might be responsible for their control. We collected intact MII oocytes, enucleated MII oocyte cytoplasts (with the spindle removed), and spindle-chromosome complexes which had been microsurgically removed. RNA was extracted, amplified, labeled, and applied to microarrays to determine if any MmRNA determinants were localized to the SCC.
Association of maternal mRNA and phosphorylated EIF4EBP1 variants with the spindle in mouse oocytes: localized translational control supporting female meiosis in mammals.
Sex, Specimen part, Disease
View SamplesThe intestinal epithelium is continuously renewed by a pool of intestinal stem cells expressing Lgr5. We show that deletion of the key autophagy gene Atg7 affects the survival of Lgr5+ intestinal stem cells. Mechanistically, this involves defective DNA repair, oxidative stress, and altered interactions with the microbiota. This study highlights the importance of autophagy in maintaining the integrity of intestinal stem cells.
Essential role for autophagy protein ATG7 in the maintenance of intestinal stem cell integrity.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
LEADeR role of miR-205 host gene as long noncoding RNA in prostate basal cell differentiation.
Cell line
View SamplesMutations in the gene encoding the transcription factor AutoImmune REgulator (AIRE) are responsible for the Autoimmune PolyEndocrinopathy Candidiasis Ecodermal Dystrophy syndrome. AIRE directs expression of tissue restricted antigens in the thymic medulla and in lymph node stromal cells and thereby substantially contributes to induction of immunological tolerance to self-antigens. Data from experimental mouse models showed that AIRE-deficiency leads to impaired deletion of autospecific T cell precursors. However, a potential role for AIRE in the function of regulatory T cell populations, which are known to play a central role in prevention of immunopathology, has remained elusive. Regulatory T cells of CD8+CD28low phenotype efficiently control immune responses in experimental autoimmune and colitis models in mice. We here show that CD8+CD28low Treg from AIRE-deficient mice are transcriptionally and phenotypically normal, exert efficient suppression of in vitro immune responses, but completely fail to prevent experimental colitis in vivo. Our data therefore demonstrate that AIRE plays an important role in the in vivo function of a naturally occurring regulatory T cell population.
Autoimmune regulator (AIRE)-deficient CD8+CD28low regulatory T lymphocytes fail to control experimental colitis.
Treatment
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