Transient regulation of Plasmodium numbers below the density that induces fever has been observed in chronic malaria infections in humans and this species transcending control cannot be explained by immunity alone. Using an in vitro system we have observed density dependent regulation of malaria parasitemia as a mechanism to possibly explain these in vivo observations.
A high parasite density environment induces transcriptional changes and cell death in Plasmodium falciparum blood stages.
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View SamplesAssessing the impact of HIV-1 infection on trancriptional program of quiescent CD4 T lymphocytes. Such cells were made susceptible to HIV-1 by dowmodulating SAMHD1 restriction factor using VLP-Vpx without any activation signal.
CD32a is a marker of a CD4 T-cell HIV reservoir harbouring replication-competent proviruses.
Sex, Specimen part
View SamplesThere is increasing evidence that breast and other cancers originate from and are maintained by a small fraction of stem/progenitor cells with self-renewal properties. Whether such cancer stem/progenitor cells originate from normal stem cells based on initiation of a de novo stem cell program, by reprogramming of a more differentiated cell type by oncogenic insults or both remains unresolved. A major hurdle in addressing these issues is lack of immortal human stem/progenitor cells that can be deliberately manipulated in vitro. We present evidence that normal and human telomerase reverse transcriptase (hTERT)-immortalized human mammary epithelial cells (hMECs) isolated and maintained in DFCI-1 medium retain a fraction with progenitor cell properties. These cells co-express basal, luminal and stem/progenitor cell markers. Clonal derivatives of progenitors co-expressing these markers fall into two distinct types: K5+/K19- (Type I) and K5+/K19+ (Type II). We show that both types of progenitor cells have self-renewal and differentiation ability. Through microarray analysis, we want to identify genes and pathways linked to human mammary epithelial stem/progenitor cell self-renewal and differentiation.
Telomerase-immortalized human mammary stem/progenitor cells with ability to self-renew and differentiate.
Sex, Specimen part
View SamplesThough it is well established that immunological functions of CD4+ T cells are time of day-dependent, the underlying molecular mechanisms remain largely obscure. To address the question whether T cells themselves harbor a functional clock driving circadian rhythms of immune function, we analyzed clock gene expression and immune responses of CD4+ T cells purified from blood of healthy subjects at different time points throughout the day. Circadian clock function as well as immune function was further analyzed in cultivated T cells and circadian clock reporter systems. We found robust rhythms of clock gene expression as well as, after stimulation, of IFN-g production and CD40L expression in both freshly isolated and in cultured CD4+ T cells. Moreover, circadian luciferase reporter activities in CD4+ T cells and in thymic sections from PER2::LUCIFERASE reporter mice suggest that endogenous T cell clock rhythms are self-sustained under constant culture conditions. Microarray analysis of stimulated CD4+ T cell cultures revealed a rhythmic regulation of the NF-kB pathway as a candidate mechanism regulating circadian immune responses. Collectively, these data demonstrate for the first time that CD4+ T cell responses are regulated by an intrinsic cellular circadian oscillator capable of driving rhythmic adaptive immune responses in vitro and in vivo.
Circadian clocks in mouse and human CD4+ T cells.
Specimen part, Time
View SamplesWhole fetal livers were collected from mouse fetuses at embryonic day 14.5 (E14.5), and single-cell suspensions were prepared by successive passage through 18-, 21 and 23-gauge needles. Fetal liver cells were maintained in Dulbecco modified Eagle medium (DMEM; Invitrogen) supplemented with 10% fetal bovine serum (FBS; Invitrogen), 100 U/ml penicillin, 100g/ml streptomycin, and 50ng/ml recombinant human thrombopoietin (TPO; Peprotech). After 5 days of culture, megakaryocytes were purified using a discontinuous bovine serum albumin gradient (BSA, SigmaAldrich; 3%, 1.5%, and 0%). Total RNA was isolated with TriReagent (MRC) following manufacturers instructions, and its quality was assessed with ND1000 Nanodrop (Peqlab) and on a 1.5% agarose gel.
miR-142 orchestrates a network of actin cytoskeleton regulators during megakaryopoiesis.
Specimen part
View SamplesYin and yang 1 (YY1) is a well-known zinc-finger transcription factor with crucial roles in normal development and malignancy. YY1 acts both as a repressor and an activator of gene expression. We have identified 23 individuals with de novo mutations or deletions of YY1 and phenotypic features that define a syndrome of cognitive impairment, behavioral alterations, intrauterine growth retardation, feeding problems, and various congenital malformations. Our combined clinical and molecular data define the 'YY1 syndrome' as a haploinsufficiency syndrome. Through immunoprecipitation of YY1-bound chromatin from person-derived cells, using antibodies recognizing both ends of the protein, we show that YY1 deletions and missense mutations lead to a global loss of YY1 binding, with a preferential retention at high-occupancy sites. Finally, we uncover a widespread loss of H3K27 acetylation in particular on the YY1-bound enhancers, underscoring a crucial role for YY1 in enhancer regulation. Collectively, these results define a clinical syndrome caused by haploinsufficiency of YY1 through dysregulation of key transcriptional regulators. Overall design: Individuals with mutations or deletion in YY1 were identified among patients with idiopathic intellectual disability. LCLs were established from 4 of these patients (1 deletion, 2 missense mutations, and 1 non-sense mutation undergoing non-sense-mediated decay) as well as from unrelated controls, and their transcriptome were compared.
YY1 Haploinsufficiency Causes an Intellectual Disability Syndrome Featuring Transcriptional and Chromatin Dysfunction.
Specimen part, Subject
View SamplesThe spatial and temporal control of Hox gene transcription is essential for patterning the vertebrate body axis. Although this process involves changes in histone posttranslational modifications, the existence of particular three-dimensional (3D) architectures remained to be assessed in vivo. Using high-resolution chromatin conformation capture methodology, we examined the spatial configuration of Hox clusters in embryonic mouse tissues where different Hox genes are active. When the cluster is transcriptionally inactive, Hox genes associate into a single 3D structure delimited from flanking regions. Once transcription starts, Hox clusters switch to a bimodal 3D organization where newly activated genes progressively cluster into a transcriptionally active compartment. This transition in spatial configurations coincides with the dynamics of chromatin marks, which label the progression of the gene clusters from a negative to a positive transcription status. This spatial compartmentalization may be key to process the collinear activation of these compact gene clusters.
The dynamic architecture of Hox gene clusters.
Specimen part
View SamplesBackground: The Epithelial Cell Adhesion Molecule (EpCAM) has been shown to be strongly expressed in human breast cancer and cancer stem cells and its overexpression has been supposed to support tumor progression and metastasis. However, effects of EpCAM overexpression on normal breast epithelial cells have never been studied before. Therefore, we analyzed effects of transient adenoviral overexpression of EpCAM on proliferation, migration and differentiation of primary human mammary epithelial cells (HMECs).
EpCAM overexpression prolongs proliferative capacity of primary human breast epithelial cells and supports hyperplastic growth.
Specimen part
View SamplesIntroduction: The Epithelial Cell Adhesion Molecule (EpCAM) has been shown to be strongly expressed in human breast cancer and cancer stem cells and its overexpression has been supposed to support tumor progression and metastasis. However, effects of EpCAM overexpression on normal breast epithelial cells have never been studied before. Therefore, we analyzed effects of transient adenoviral overexpression of EpCAM on proliferation, migration and differentiation of primary human mammary epithelial cells (HMECs).
EpCAM overexpression prolongs proliferative capacity of primary human breast epithelial cells and supports hyperplastic growth.
Specimen part, Subject
View SamplesCD4+ cells from Foxp3.eGFP mice containing Foxp3- Teff and Foxp3+ Treg cells were treated with anti-CD3/CD28 monoclonal antibodies or soluble OX40L and JAG1 for 3 days to induce TCR-dependent vs TCR-independent Treg proliferation. Untreated fresh CD4+ T-cells used as control. Post treatment T-cell proliferation was confirmed by Cell Trace violet dilution and Foxp3+ (Treg) and Foxp3-(Teff) were sorted. Differential gene expression profiling between Tregs and Teff cells among control, anti-CD3/CD28 and OX40L-JAG1 treated cultured was performed using affymetrix mouse gene 2.0 ST micro array.
OX40L-JAG1-Induced Expansion of Lineage-Stable Regulatory T Cells Involves Noncanonical NF-κB Signaling.
Specimen part, Treatment
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