Transplant recipients spontaneously accepting their grafts in the absence of immunosuppression demonstrate the feasibility of attaining allograft tolerance in humans. Previous studies have identified blood transcriptional and cell phenotypic markers specific for either liver or kidney tolerant recipients, but the two settings have not been directly compared yet employing the same platforms. To identify potential similarities in immune parameters between recipients tolerant to different organs, we analyzed blood samples from tolerant and non-tolerant liver and kidney recipients employing whole genome expression microarrays. Tolerant and non-tolerant liver and kidney recipients differed in their peripheral blood expression patterns, but no significant overlap was observed between the two datasets. This was confirmed at the functional level by employing gene set enrichment analysis.The lack of obvious similarities in immune parameters associated with liver and kidney tolerant recipients implies the involvement of different mechanisms in the two settings and argues against the existence of a common immunological constant of spontaneous operational tolerance in clinical transplantation.
Comparison of transcriptional and blood cell-phenotypic markers between operationally tolerant liver and kidney recipients.
Specimen part
View Samplesmmunosuppressive drugs can be completely withdrawn in up to 20% of liver transplant recipients, commonly referred to as operationally tolerant. Immune characterization of these patients, however, has not been performed in detail, and we lack tests capable of identifying tolerant patients among recipients receiving maintenance immunosuppression. In the current study we have analyzed a variety of biological traits in peripheral blood of operationally tolerant liver recipients in an attempt to define a multiparameter fingerprint of tolerance. Thus, we have performed peripheral blood gene expression profiling and extensive blood cell immunophenotyping on 16 operationally tolerant liver recipients, 16 recipients requiring on-going immunosuppressive therapy, and 10 healthy individuals. Microarray profiling identified a gene expression signature that could discriminate tolerant recipients from immunosuppression-dependent patients with high accuracy. This signature included genes encoding for ?d T-cell and NK receptors, and for proteins involved in cell proliferation arrest. In addition, tolerant recipients exhibited significantly greater numbers of circulating potentially regulatory T-cell subsets (CD4+CD25+ T-cells and Vd1+ T cells) than either non-tolerant patients or healthy individuals. Our data provide novel mechanistic insight on liver allograft operational tolerance, and constitute a first step in the search for a non-invasive diagnostic signature capable of predicting tolerance before undergoing drug weaning.
Multiparameter immune profiling of operational tolerance in liver transplantation.
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View SamplesBackground. Although the emergence of RNA sequencing (RNA-seq), microarrays remain in widespread use for gene expression analysis in the clinic. There are over 767,000 RNA microarrays from human samples in public repositories, which are an invaluable resource for biomedical research and personalized medicine. The absolute gene expression analysis allows the transcriptome profiling of all expressed genes under the specific biological condition without the need of a reference sample. However, the background fluorescence represents a challenge to determine the absolute gene expression in microarrays. Given that the Y chromosome is absent in female subjects, we used it as a new approach for absolute gene expression analysis in which the fluorescence of the Y chromosome genes of female subjects was used as the background fluorescence for all the probes in the microarray. This fluorescence was used to establish an absolute gene expression threshold, allowing the differentiation between expressed and non-expressed genes in microarrays.
A novel approach for human whole transcriptome analysis based on absolute gene expression of microarray data.
Sex, Specimen part
View SamplesIntroduction: The genetic origin of familial combined hyperlipidemia (FCH) is not well understood. We used microarray profiling of peripheral blood monocytes to search novel genes and pathways involved in FCH. Methods: Fasting plasma for determination of lipid profiles, inflammatory molecules, and adipokines was obtained and peripheral blood monocytes were isolated from male FCH patients basally and after 4 weeks of atorvastatin treatment. Sex-, age- and adiposity-matched controls were also studied. Gene expression profile was analyzed using Affymetrix Human Genome U133A 2.0 GeneChip arrays. Results: Analysis of gene expression by cDNA microarrays showed that 82 genes were differentially expressed in FCH monocytes compared to controls. Atorvastatin treatment modified the expression of 87 genes. Changes in the expression of some genes, confirmed by real time RT-PCR, (CD36, leucine-rich repeats and immunoglobulin-like domains-1, tissue factor pathway inhibitor 2, myeloid cell nuclear differentiation antigen tumor necrosis factor receptor superfamily, member 25 and CD96) may be related to a proinflammatory environment in FCH monocytes, which is partially reversed by atorvastatin. Higher plasma levels of triglycerides and free fatty acids and lower levels of adiponectin in FCH patients could also trigger changes in gene expression that atorvastatin cannot modify. Conclusions: Our results demonstrate clear differences in gene expression in FCH monocytes compared with those of matched healthy controls, some of which are influenced by atorvastatin treatment.
Monocyte gene-expression profile in men with familial combined hyperlipidemia and its modification by atorvastatin treatment.
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View SamplesIn this study we analyzed the behavior of bone marrow MSC (BM-MSC) from MPN patients with the mutation in JAK2V617F. We initially characterized the biological function and gene expression profile changes in BM-MSC from MPN patients when compared to BM-MSC of healthy donors (HD). Then, we established co-cultures between MSC cell lines (HTERT and HS5) and the UKE-1 MPN cell line, and performed RT-PCR to study if the leukemic cells were able to modify the genes related to hematopoietic support.
Mesenchymal stromal cells (MSC) from JAK2+ myeloproliferative neoplasms differ from normal MSC and contribute to the maintenance of neoplastic hematopoiesis.
Specimen part, Disease stage, Subject
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Intra-graft expression of genes involved in iron homeostasis predicts the development of operational tolerance in human liver transplantation.
No sample metadata fields
View SamplesComplications due to long-term administration of immunosuppressive therapy increase the morbidity and mortality of liver transplant recipients. Discontinuation of immunosuppressive drugs in recipients spontaneously developing operational tolerance could substantially lessen this burden. However, this strategy results in the development of rejection in a high proportion of recipients who require lifelong immunosuppression. Thus, there is a need to identify predictive factors of successful drug withdrawal and to define the clinical and histological outcomes of operationally tolerant liver recipients. Methods. We enrolled 102 stable liver transplant recipients in an immunosuppression withdrawal trial in which drugs were gradually discontinued over a 6-9 month period. Patients with stable graft function and no signs of rejection in a liver biopsy conducted 12 months after cessation of immunosuppressive therapy were considered operationally tolerant. Results. Out of the 98 recipients who completed the study, immunosuppression discontinuation was successful in 41 recipients and rejection occurred in 57. Rejection episodes were mild and were resolved in all cases. Development of tolerance was independently associated with time elapsed since transplantation, recipient age, and male gender. No histological damage was apparent in protocol biopsies performed after successful drug withdrawal.
Intra-graft expression of genes involved in iron homeostasis predicts the development of operational tolerance in human liver transplantation.
Age, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Aberrant epigenome in iPSC-derived dopaminergic neurons from Parkinson's disease patients.
Sex, Specimen part, Disease, Disease stage, Subject
View SamplesIn clinical organ transplantation complete cessation of immunosuppressive therapy can be successfully accomplished in selected recipients providing a proof-of-principle that allograft tolerance is attainable in humans. The intra-graft molecular pathways associated with human allograft tolerance, however, have not been comprehensively studied before. In this study we analyzed sequential liver tissue samples collected from liver recipients enrolled in a prospective multicenter immunosuppressive withdrawal clinical trial. Tolerant and non-tolerant recipients differed in the intra-graft expression of genes involved in the regulation of iron homeostasis.These results point to a critical role of iron homeostasis in the regulation of intra-graft alloimmune responses in humans and provide a set of novel biomarkers to conduct drug-weaning trials in liver transplantation.
Intra-graft expression of genes involved in iron homeostasis predicts the development of operational tolerance in human liver transplantation.
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View SamplesWe analysed the RNA profile of IPSC-derived dopaminergic neurons from idiophatic and genetic form (LRRK2) of Parkinsons disease (PD). Both, idiopathic and genetic form of the disease show similar expression alterations and were merged in one whole PD group. We found 437 differentially expressed genes (DEGs) in the PD group as a whole. Up-regulated DEGs (n=254) encompassed genes involved in neural functions and transcription factor functions whereas down-regulated DEGs (n=183) affected basic homeostasis. These data point towards the presence of gene - and also protein - expression changes in DAn from PD patients which co-occur simultaneously along with DNA methylation changes.
Aberrant epigenome in iPSC-derived dopaminergic neurons from Parkinson's disease patients.
Sex, Specimen part, Disease, Disease stage
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