Dengue virus (DENV) infects hundreds of millions of people annually, yet there is only a limited knowledge of the host immune response to dengue. Here, we used a systems biological approach to perform a detailed analysis of the innate immune response to DENV infection in the whole blood samples of acutely infected humans in Bangkok, Thailand. Transcriptomic analysis revealed that genes encoding pro-inflammatory mediators and type I IFN related proteins, were associated with high levels of virus during the first few days of infection. Individuals with low or negative viremia at the late stage of fever were enriched with genes associated with pathways involved in cell cycle, proliferation, cell metabolism and translational control. Meta-analysis showed significant enrichment in genes specific for innate cells (monocytes, macrophages and DCs) in the specimens with high VL and enrichment in genes specific for NK cells, CD4+ and CD8+ T cells as well as B cells in specimens with low VL. Furthermore, flow cytometric analysis revealed an expansion in the numbers of CD14+CD16+ monocytes and depletion of CD14dimCD16++ cells and BDCA-1+ myeloid DC in blood. Consistent with this, in a non-human primate model, infection with DENV boosted the numbers of CD14+CD16+ monocytes in the blood and in secondary lymphoid organs. In vitro, freshly isolated blood monocytes infected with DENV up regulated CD16 and mediated robust differentiation of resting B cells to CD27++CD38++ plasmablasts and IgG and IgM secretion. Taken together, these data provide a detailed picture of the innate response to dengue infection in humans, and highlight an unappreciated role for CD14+CD16+ monocytes in promoting the differentiation of plasmablasts and mediating antibody response to DENV.
Dengue virus infection induces expansion of a CD14(+)CD16(+) monocyte population that stimulates plasmablast differentiation.
Specimen part, Subject
View SamplesCD8 T cells play roles in eliminating virus infected targets through cytotoxic effector function and are of great interest from vaccination prespective. Previous studies suggest that the cytokines produced by the CD8 T cells may contribute to the pathological consequences. Because the dengue specific memory T cells strongly secrete cytokines upon in vitro stimulation with heterologous viral antigen, the cytokine storm induced by activated T cells may contribute to the immunopathology of dengue infection. Moreover, the CD8 T cell expansion peaks before or around the time of the peak of clinical symptoms, and the frequency of activated CD8 T cells and cytokine producing cells was somewhat higher in patients with severe forms of dengue disease.
Characterization of Human CD8 T Cell Responses in Dengue Virus-Infected Patients from India.
Age, Specimen part, Disease, Disease stage
View SamplesThe majority of NK cells (~90%) are phenotypically characterized as CD56dimCD16+, while the remaining are CD56brightCD16-. The cytotoxic CD56dimCD16+ NK subset expresses higher levels of chemokine receptors, and therefore is preferentially recruited to sites of inflammation. Encounters between CD56dimCD16+ NK cells with target cells and locally secreted inflammatory cytokines synergize to induce activation of this subset, leading to dramatically increased cytotoxic activity against target cells and abundant pro-inflammatory cytokine production often equivalent to that of the CD56brightCD16- population. The early recruitment of activation of CD56dimCD16+ NK cells to sites of inflammation raises many important questions regarding the potential immune functions of these cells that extend beyond their cytotoxic capabilities. This study has sought to elucidate the genetic profile of activated CD56dimCD16+ NK cells via a series of laboratory-based approaches coupled with a bioinformatics persective.
Gene expression profiling of the human natural killer cell response to Fc receptor activation: unique enhancement in the presence of interleukin-12.
Specimen part, Subject
View SamplesGeminin is a small nucleoprotein that neuralizes ectoderm in the Xenopus embryo. Geminin promotes neural fate acquisition of mouse embryonic stem cells: Geminin knockdown during neural fate acquisition decreased expression of neural precursor cell markers (Pax6, Sox1), while increasing expression of Pitx2, Lefty1 and Cited2, genes involved in formation of the mouse node. Here we differentiated mouse embryonic stem cells into embryoid bodies to study Geminin's ability to repress primitive streak mesendoderm fate acquisition. We used microarrays to define the sets of genes that are regulated by Geminin during cell fate acquisition in embryoid bodies, using Dox-inducible Geminin knockdown or overexpression mouse embryonic stem cell lines.
Geminin restrains mesendodermal fate acquisition of embryonic stem cells and is associated with antagonism of Wnt signaling and enhanced polycomb-mediated repression.
Specimen part
View SamplesFormation of the complex vertebrate nervous system begins when pluripotent cells of the early embryo are directed to acquire a neural fate. Although cell intrinsic controls play an important role in this process, the molecular nature of this regulation is not well defined. Here we assessed the role for Geminin, a nuclear protein expressed in embryonic cells, in neural fate acquisition from mouse embryonic stem (ES) cells. While Geminin knockdown does not affect the ability of ES cells to maintain or exit pluripotency, we found that it significantly impairs their ability to acquire a neural fate. Conversely, Geminin overexpression promotes neural gene expression, even in the presence of growth factor signaling that antagonizes neural transcriptional responses. These data demonstrate that Geminins activity contributes to mammalian neural cell fate acquisition. We investigated the mechanistic basis of this phenomenon and found that Geminin maintains a hyperacetylated and open chromatin conformation at neural genes. Interestingly, recombinant Geminin protein also rapidly alters chromatin acetylation and accessibility even when Geminin is combined with nuclear extract and chromatin in vitro. These findings define a novel activity for Geminin in regulation of chromatin structure. Together, these data support a role for Geminin as a cell intrinsic regulator of neural fate acquisition that promotes expression of neural genes by regulating chromatin accessibility and histone acetylation.
Geminin promotes neural fate acquisition of embryonic stem cells by maintaining chromatin in an accessible and hyperacetylated state.
Specimen part, Treatment
View SamplesExpression profile of human donor lungs that have developed primary graft dysfunction (PGD) after lung transplantation and those that have not.
Expression profiling of human donor lungs to understand primary graft dysfunction after lung transplantation.
No sample metadata fields
View SamplesThe Lim1 gene has essential functions during several stages of kidney development. In particular, a tissue specific knockout in the early metanephric mesenchyme results in the formation of the earliest nephron precursor, the renal vesicle, but failure of this structure to progress to the next stage, the comma shaped body. To better understand the molecular nature of this developmental arrest we used a laser capture microdissection-microarray strategy to examine the perturbed gene expression pattern of the mutant renal vesicles. Among the genes found differently expressed were Chrdl2, an inhibitor of BMP signaling, the pro-apoptotic factor Bmf, as well as myob5, an atypical myosin which modulates chemokine and transferring signaling, and pdgfr1, which is important in epithelial folding. Of particular interest, the microarray data indicated that the Dkk1 gene, which encodes an inhibitor of Wnt signaling, was downregulated nine fold in mutants. This was confirmed by in situ hybridizations. It is interesting to note that Lim1 and Dkk1 mutant mice have striking similarities in phenotype. These results suggest that the Dkk1 gene might be a key downstream effector of Lim1 function.
Laser capture-microarray analysis of Lim1 mutant kidney development.
No sample metadata fields
View SamplesThese investigations studied the fundamentals of how plants perceive gravity and develop in microgravity. It informs how gene regulation is altered by spaceflight conditions.
Comparative transcriptomics indicate changes in cell wall organization and stress response in seedlings during spaceflight.
Specimen part
View SamplesComplete (whole) embryonic kidneys were dissected from wild type and Hoxa11, Hoxd11 compound null embryons throughout development. Targets from two biological replicates of each were generated and the expression profiles were determined using Affymetrix MOE430A and MOE430B arrays. Comparisons between normal and mutant and comparisons of development samples identified global patterns of gene regulation in kidney development
Comprehensive microarray analysis of Hoxa11/Hoxd11 mutant kidney development.
No sample metadata fields
View SamplesE11.5 metanephric mesenchyme and ureteric bud were dissected from the E11.5 kidney rudiment using fine manual microdissection (ureteric bud only) or both fine manual microdissection and laser capture microdissection (metanephric mesenchyme) to define the gene expression profiles of these structures. Additionally, HoxA11, HoxD11 compound null E11.5 metanephric mesenchyme was obtained through laser capture microdissection allowing analysis of possible Hox targets in kidney development. Targets from multiple biological replicates of each were generated and the expression profiles were determined using Affymetrix MOE430_v2 arrays.
Comprehensive microarray analysis of Hoxa11/Hoxd11 mutant kidney development.
No sample metadata fields
View Samples