Comparison of two Chlamydia-specific CD4 T cells that are dependent on iNOS to terminate Chlamydia replication in epithelial cells to two Chlamydia-specific CD4 T cells that are iNOS-independent: Chlamydia trachomatis urogenital serovars replicate predominately in epithelial cells lining the reproductive tract. This tissue tropism poses a unique challenge for the host immune system and vaccine development. Studies utilizing the Chlamydia muridarum mouse model have shown that CD4 T cells are critical and sufficient to clear primary genital tract infections. In vitro studies have shown that CD4 T cells terminate the infection in epithelial cells by up regulating epithelial iNOS transcription and nitric oxide production via IFN-gammaand T cell-epithelial cell interactions mediated by LFA-1-ICAM-1. This mechanism however is not critical as iNOS-deficient mice clear infections normally, and IFN-gamma deficient mice clear 99.9% of the infection with near normal kinetics. We recently showed that a subset of Chlamydia-specific CD4 T cell clones were able to terminate replication in epithelial cells using a mechanism that was independent of iNOS and IFN-gamma. That mechanism did not require physical lysis of infected cells, but instead required T cell degranulation. In this study we advanced that work using gene expression microarrays to compare CD4 T cell clones that are able to terminate epithelial replication via an iNOS-independent mechanism to iNOS-dependent CD4 T cell clones. Micro array experiments showed that Plac8 was differentially expressed by the T cell clones having the iNOS-independent mechanism. Plac8-deficient mice had significantly delayed clearance of C. muridarum genital tract infections, and that the large majority of Plac8-deficient mice treated with the iNOS-inhibitor N-monomethyl-L-arginine (MLA) were unable to resolve a C. muridarum genital tract infection over 8 weeks. These results demonstrate that there are two independent and redundant T cell mechanisms for clearing C. muridarum genital tract infections; one mechanism dependent on iNOS, the other mechanism dependent on Plac8. While T cells subsets have been defined by cytokine profiles, there are important subdivisions by effector functions, in this case CD4Plac8.
Plac8-dependent and inducible NO synthase-dependent mechanisms clear Chlamydia muridarum infections from the genital tract.
No sample metadata fields
View SamplesIntervertebral disc degeneration is an important contributor to chronic low back pain. While a wide spectrum of clinically relevant degenerative disc phenotypes have been observed during aging, their molecular underpinning have not been established.
Comparison of inbred mouse strains shows diverse phenotypic outcomes of intervertebral disc aging.
Age, Specimen part
View SamplesExpression analysis from two genetically engineered mouse models of osteosarcoma determine the expression profile of mouse osteosarcoma Human osteosarcoma (OS) is comprised of three different subtypes: fibroblastic, chondroblastic and osteoblastic. We previously generated a mouse model of fibroblastic OS by conditional deletion of p53 and Rb in osteoblasts. Here we report an accurate mouse model of the osteoblastic subtype using shRNA-based suppression of p53. Like human OS, tumors frequently present in the long bones and preferentially disseminate to the lungs; features less consistently modeled using Cre:lox approaches. Our approach allowed direct comparison of the in vivo consequences of targeting the same genetic drivers using different technology. This demonstrated that the effects of Cre:lox and shRNA mediated knock-down are qualitatively different, at least in the context of osteosarcoma. Through the use of complementary genetic modification strategies we have established a model of a distinct clinical subtype of OS that was not previously represented and more fully recapitulated the clinical spectrum of this human tumor.
Modeling distinct osteosarcoma subtypes in vivo using Cre:lox and lineage-restricted transgenic shRNA.
Specimen part
View SamplesGlioblastoma multiforme (GBM) is the most aggressive form of brain tumors. Despite radical surgery and radiotherapy supported by chemotherapy, the disease still remains incurable with extremely low median survival rate of 12-15 months from the time of initial diagnosis. The main cause of treatment failure is considered to be the presence of cells that are resistant to such treatment. MicroRNAs (miRNAs) as regulators of gene expression are involved in the tumor pathogenesis, including GBM. MiR-338 is a brain specific miRNA which has been described to target pathways involved in proliferation and differentiation. In our study, miR-338-3p and -5p were differentially expressed in GBM tissue in comparison to non-tumor brain tissue. Overexpression of miR-338-3p with miRNA mimic did not show any changes in proliferation rates in GBM cell lines (A172, T98G, U87MG). On the other hand, pre-miR-338-5p notably decreased proliferation and caused cell cycle arrest. Since radiation is currently the main treatment modality in GBM, we combined overexpression of pre-miR-338-5p with radiation, which led to significantly decreased of cell proliferation, and increased cell cycle arrest and apoptosis in comparison to only irradiated cells. To better elucidate the mechanism of action, we performed gene expression profiling analysis that revealed targets of miR-338-5p being Ndfip1, Rheb, ppp2R5a. These genes have been described to be involved in DNA damage response, proliferation and cell cycle regulation. To our knowledge, this is the first study to describe role of miR-338-5p in GBM and its potential to improve sensitivity of GBM to radiation.
MiR-338-5p sensitizes glioblastoma cells to radiation through regulation of genes involved in DNA damage response.
Specimen part, Cell line
View SamplesLymphoblastoid cell lines (LCLs), originally collected as renewable sources of DNA, are now being used as a model system to study genotype-phenotype relationships in human cells. These cell lines have been used to search for genetic variants that are associated with drug response as well as with more basic cellular traits such as RNA levels. In setting out to extend such studies by searching for genetic variants contributing to drug response, we observed that phenotypes in LCLs were, in our lab and others, significantly affected by experimental confounders (i.e. in vitro growth rate, metabolic state, and relative levels of the Epstein-Barr virus used to transform the cells). As we did not find any SNPs associated with genome-wide significance to drug response, we evaluated whether incorporating RNA expression levels (and eQTLs) in the analysis could increase power to detect such effects. As previously shown, cis-acting eQTLs were detectable for a sizeable fraction of RNAs and baseline levels of many RNAs predicted response to several drugs. However, we found only limited evidence that SNPs influenced drug response through their effect on expression of RNA. Efforts to use LCLs to map genes underlying cellular traits will require great care to control experimental confounders, unbiased methods for integrating and interpreting such multi-dimensional data, and much larger sample sizes than have been applied to date.
Genetic analysis of human traits in vitro: drug response and gene expression in lymphoblastoid cell lines.
No sample metadata fields
View SamplesCCRF_CEM cell line was treated by AB61 which is potent cytotoxic compound, as the positive controls were used tubercidin and actinomycin D.
7-(2-Thienyl)-7-Deazaadenosine (AB61), a New Potent Nucleoside Cytostatic with a Complex Mode of Action.
Cell line
View SamplesMicroarrays were conducted to asses the effect of Stb3 deletion in immediate transcriptional induction in response to glucose
Stb3 binds to ribosomal RNA processing element motifs that control transcriptional responses to growth in Saccharomyces cerevisiae.
No sample metadata fields
View SamplesCondensin complexes are highly conserved for chromosome compaction to ensure their faithful segregation in mitosis. Condensin II is present in the nucleus throughout the cell cycle, including interphase. The aim of these experiments is to investigate the changes of gene expression in knockdown of NCAPH2, a condensin II subunit, in mouse embryonic stem cells compared to their control cells. Overall design: Examination of gene expression of controls and NCAPH2 knockdown cells by RNA-seq
Condensin II is anchored by TFIIIC and H3K4me3 in the mammalian genome and supports the expression of active dense gene clusters.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Increased risk of genetic and epigenetic instability in human embryonic stem cells associated with specific culture conditions.
Sex, Specimen part, Cell line
View SamplesThe self-renewal and differentiation capacities of human pluripotent stem cells (hPSCs) make them good sources of cells for cell transplantation therapy, drug development, and studies of cellular differentiation and development. However, the large numbers of cells necessary for many of these applications require extensive expansion of hPSC cultures, a process that has been associated with applications require extensive expansion of hPSC cultures, a process that has been associated with genetic and epigenetic alterations. We have performed a systematic study over more than 100continuous passages to identify characteristics of culture conditions (including passage method, substrate, and media type) that influence the genetic and epigenetic stability and the phenotypic characteristics of hPSCs. The predominant effects we observed were increased genetic instability with enzymatic passage, higher cell proliferation with feeder-free substrate, and variations among cultures in global gene expression and DNA methylation with time in culture. We observed recurrent duplications in two genomic regions that have been noted in earlier studies to be hotspots for duplication in hPSCs, as well as a previously unreported recurrent deletion of the tumor suppressor gene TP53 in all but one of the long-term culture conditions; the exception was the condition using mechanical passaging on feeder layers. The deletion of TP53 is associated with decreased mRNA expression of TP53, as well as alterations in the expression of several other genes in the TP53 pathway, which taken together indicate a decrease in the function of the TP53 pathway. Our results highlight the need for careful assessment of effects of culture conditions on cells intended for clinical therapies.
Increased risk of genetic and epigenetic instability in human embryonic stem cells associated with specific culture conditions.
Sex, Cell line
View Samples