The anti-HIV humoral immune response following acute infection is delayed and ineffective. HIV envelope protein gp120 binds to and signals through 47 on T cells. We show that gp120 also binds and signals through 47 on B cells, resulting in an abortive proliferative response. In primary B cells, gp120 signaling through 47 resulted in increased expression of TGF-1 and the B cell inhibitory receptor FcRL4. Co-culture of B cells with HIV-infected autologous CD4+ T cells also resulted in increased B cell FcRL4 expression. These findings indicate that, in addition to inducing chronic immune activation, viral proteins can contribute directly to HIV-associated B cell dysfunction, thus providing a mechanism whereby the virus subverts the early HIV-specific humoral immune response.
The HIV-1 envelope protein gp120 impairs B cell proliferation by inducing TGF-β1 production and FcRL4 expression.
Specimen part, Disease, Time
View SamplesBackground: Venous hypertension is often present in advanced and in acute decompensated heart failure (HF). However, it is unclear whether high intravenous pressure can cause alterations in homeostasis by promoting inflammation and endothelial cell (EC) activation. We used an experimental model of acute, local venous hypertension to study the changes in circulating inflammatory mediators and EC phenotype that occur in response to biomechanical stress. Methods and Results: Twenty-four healthy subjects (14 men, age 352 years) were studied. Venous arm pressure was increased to ~30 mmHg above baseline level by inflating a tourniquet cuff around the dominant arm (test arm). Blood and endothelial cells (ECs) were sampled from test and control arm (lacking an inflated cuff) before and after 75 minutes of venous hypertension, using angiocatheters and endovascular wires. Magnetic beads coated with EC specific antibodies were used for EC separation; amplified mRNA was analyzed by Affymetrix HG-U133 2.0 Microarray. Plasma endothelin-1 (ET-1), interleukin-6 (IL-6), vascular cell adhesion molecule-1 (VCAM-1) and chemokine (C-X-C motif) ligand 2 (CXCL2) were significantly increased in the congested arm. 5,332 probe sets were differentially expressed in venous ECs before vs. after testing. Among the 143 probe sets that exhibited a significant absolute fold change >2, we identified several inflammatory mediators including ET-1, VCAM-1, and CXCL2. Conclusions: Acute experimental venous hypertension is sufficient to cause local increase in circulating inflammatory mediators and to activate venous ECs in healthy human subjects. Additional work is needed to determine the effect of venous hypertension in patients with established HF.
Peripheral venous congestion causes inflammation, neurohormonal, and endothelial cell activation.
Specimen part, Treatment, Subject
View SamplesTREM-1 is an orphan immunoreceptor expressed on monocytes, macrophages, and neutrophils. TREM-1 associates with and signals via the adapter protein DAP12/TYROBP, which contains an immunoreceptor tyrosine-based activation motif (ITAM). TREM-1 activation by receptor cross-linking is pro-inflammatory, and can amplify cellular responses to Toll-like receptor (TLR) ligands such as bacterial lipopolysaccharide (LPS). To investigate the cellular consequences of TREM-1 activation, we have characterized global gene expression changes in human monocytes in response to TREM-1 cross-linking in comparison to and combined with LPS. Both TREM-1 activation and LPS up-regulate chemokines, cytokines, matrix metalloproteases, and PTGS/COX2, consistent with a core inflammatory response. However, other immunomodulatory factors are selectively induced, including SPP1 and CSF1 (i.e., M-CSF) by TREM-1 activation and IL-23 and CSF3 (i.e., G-CSF) by LPS. Additionally, cross-talk between TREM-1 activation and LPS occurs on multiple levels. While synergy in GM-CSF protein production is reflected in commensurate mRNA abundance, comparable synergy in IL-1b protein production is not. TREM-1 activation also attenuates the induction of some LPS target genes, including those that encode IL-12 cytokine family subunits. Whereas positive TREM-1 outputs are abolished by the PI3K inhibitor wortmannin, this attenuation is largely PI3K-independent. These experiments provide a detailed analysis of the cellular consequences of TREM-1 activation, and highlight some of the complexity in signal integration between ITAM- and TLR-mediated signaling.
Innate immune responses to TREM-1 activation: overlap, divergence, and positive and negative cross-talk with bacterial lipopolysaccharide.
No sample metadata fields
View SamplesChronic tendon injuries, also known as tendinopathy, are common among professional and recreational athletes. These injuries result in a significant amount of morbidity and health care expenditure and yet little is known about the molecular mechanism leading to tendinopathy. We have used histological evaluation and molecular profiling to determine the gene expression changes in 23 human patients undergoing surgical procedures for the treatment of chronic tendinopathy. Diseased tendons have altered extracellular matrix, fiber disorientation, increased cellular content and vasculature and the absence of inflammatory cells. Global gene expression profiling identified 1783 transcripts with significant different expression patterns in the diseased tendons. Global pathway analysis further suggests altered expression of extracellular matrix proteins and the lack of an appreciable inflammatory response. We have identified pathways and genes regulated in tendinopathy samples that will help contribute to the understanding of the disease towards the development of novel therapeutics.
Regulation of gene expression in human tendinopathy.
Sex, Age, Specimen part, Disease, Disease stage, Subject
View SamplesCF patients suffer from chronic and recurrent respiratory tract infections which eventually lead to lung failure followed by death. Pseudomonas aeruginosa is one of the major pathogens for CF patients and is the principal cause of mortality and morbidity in CF patients.
Bacterial adaptation during chronic infection revealed by independent component analysis of transcriptomic data.
No sample metadata fields
View SamplesMammalian spermatogenesis is a complex biological process that occurs within a highly organized tissue, the seminiferous epithelium. The coordinated maturation of spermatogonia, spermatocytes and spermatids suggests the existence of precise programs of gene expression in these cells as well as in their neighboring somatic Sertoli cells. The objective of this study was to elucidate genes encoding the proteins that execute these programs. Rat seminiferous tubules at stages I, II-III, IV-V, VI, VIIa,b, VIIc,d, VIII, IX-XI, XII, XIII-XIV of the cycle were isolated by microdissection and Sertoli cells, spermatogonia plus early spermatocytes, pachytene spermatocytes and spermatids were purified from enzymatically-dispersed testes. Microarray analysis using Rat Genome 230 2.0 arrays identified a total of 16,971 probe sets that recognized transcripts. A comparison with the transcriptome of other tissues identified 398 testis-specific probe sets, which therefore are potential targets for the development of new contraceptives. Sequential waves of cell and stage-specific gene expression are associated with progression of germ cells through the stages of the cycle of the seminiferous epithelium and 1612 probe sets recognized transcripts whose expressions varied at least 4-fold across the stages of the cycle. Pathway analyses reveal that entire biological processes are regulated cyclically in testicular cells. Important among these are cell cycle and DNA repair. Thus, stage-specific gene expression is a widespread and fundamental characteristic of spermatogenic cells and Sertoli cells.
Stage-specific gene expression is a fundamental characteristic of rat spermatogenic cells and Sertoli cells.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
TET1 is a maintenance DNA demethylase that prevents methylation spreading in differentiated cells.
Cell line
View SamplesWe report that full length TET1 (TET1-FL) overexpression fails to induce global DNA demethylation in HEK293T cells. The preferential binding of TET1-FL to hypomethylated CpG islands (CGIs) through its CXXC domain leads to its inhibited 5-hydroxymethylcytosine (5hmC) production as methylation level increases. TET1-FL-induced 5hmC accumulates at CGI edges, while TET1 knockdown induces methylation spreading from methylated edges into hypomethylated CGIs. However, TET1 can regulate gene transcription independent of its dioxygenase catalytic function. Thus, our results identify TET1 as a maintenance DNA demethylase that does not purposely decrease methylation levels, but specifically maintains the DNA hypomethylation state of CGIs in adult cells.
TET1 is a maintenance DNA demethylase that prevents methylation spreading in differentiated cells.
Cell line
View SamplesIn the present study, microarray analysis was performed on RNA isolated from purified SLCs, PLCs, ILCs, ALCs and bone stem cells, using Affymetrix Rat Genome RAE230 2.0 arrays which monitor ~30,000 transcripts from over ~28,000 well-substantiated genes. The focus is on the differences and similarities between SLCs and bone stem cells, and between SLCs and PLCs, ILCs and ALCs
Stem Leydig cell differentiation: gene expression during development of the adult rat population of Leydig cells.
Specimen part
View SamplesSkeletal muscle atrophy is a consequence of many diseases, environmental insults, inactivity, age and injury. Atrophy is characterized by active degradation and removal of contractile proteins and a reduction in fiber size. Animal models have been extensively used to identify pathways leading to atrophic conditions. Here we have used genome-wide expression profiling analysis and quantitative PCR to identify the molecular changes that occur in two clinically relevant animal mouse models of muscle atrophy, hindlimb casting and Achilles tendon laceration (tenotomy). Gastrocnemius muscle samples were collected 2, 7 and 14 days after insult. The total amount of muscle loss as measured by wet weight and muscle fiber size was equivalent between models, although tenotomy resulted in a more rapid induction of muscle atrophy. Furthermore, tentomy resulted in the regulation of significantly more mRNA transcripts then casting. Analysis of the regulated genes and pathways suggest that the mechanism of atrophy is distinct between these models. The degradation following casting appears ubiquitin-proteasome-mediated while degradation following tenotomy appears lysosomal and matrix-metalloproteinase (MMP)-mediated. This data suggests that there are multiple mechanisms leading to muscle atrophy and that specific therapeutic agents may be necessary to combat the atrophy seen under different conditions.
Distinct protein degradation profiles are induced by different disuse models of skeletal muscle atrophy.
Sex, Specimen part, Treatment, Time
View Samples