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View Samplesmmunosuppressive drugs can be completely withdrawn in up to 20% of liver transplant recipients, commonly referred to as operationally tolerant.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.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
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 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.
No sample metadata fields
View SamplesMice with a congenital Snord116 deletion model aspects of the Prader-Willi Syndrome. In this study, we examine the gene expression changes in four hypothalamic nuclei across 24-hour food deprived versus ad libitum fed mice. Overall design: Using mice with paternal deletion of the Snord116 cluster, we laser-captured microdissected four hypothalamic nuclei for RNA sequencing: the ventromedial hypothalamus (VMH), arcuate nucleus (ARC), dorsomedial hypothalamus (DMH) and paraventricular nucleus (PVN). Samples were taken from male mice in either the fed or 24-hour fasted state.
Hypothalamic loss of Snord116 recapitulates the hyperphagia of Prader-Willi syndrome.
Cell line, Subject
View SamplesTo obtain an overview of the cellular functions regulated by ZNF217 signaling in breast-cancer cell lines, we performed global gene-expression profiling on MDA-MB-231-pcDNA6 and MDA-MB-231-ZNF217 cells
ZNF217 is a marker of poor prognosis in breast cancer that drives epithelial-mesenchymal transition and invasion.
Specimen part
View SamplesRNA helicases DDX5 and DDX17 are members of a large family of highly conserved proteins involved in gene expression regulation, although their in vivo targets and activities in biological processes like cell differentiation, that requires reprogramming of gene expression programs at multiple levels, are not well characterized. In this report, we uncovered a new mechanism by which DDX5 and DDX17 cooperate with hnRNP H/F splicing factors to define epithelial- and myoblast-specific splicing subprograms. We next observed that downregulation of DDX5 and DDX17 protein expression during epithelial to mesenchymal transdifferentiation and during myogenesis contributes to switching splicing programs during these processes. Remarkably, this downregulation is mediated by the production of microRNAs induced upon differentiation in a DDX5/DDX17-dependent manner. Since DDX5 and DDX17 also function as coregulators of master transcriptional regulators of differentiation, we propose to name these proteins master orchestrators of differentiation, that dynamically orchestrate several layers of gene expression.
RNA helicases DDX5 and DDX17 dynamically orchestrate transcription, miRNA, and splicing programs in cell differentiation.
Specimen part, Cell line
View SamplesThe genome of mantle cell lymphoma (MCL) is, in addition to the translocation t(11;14), characterized by a high number of secondary chromosomal gains and losses that likely account for the varying survival times of MCL patients. We investigated 77 primary MCL tumors with available clinical information using high resolution RNA expression and genomic profiling and applied our recently developed gene expression and dosage integrator (GEDI) algorithm to identify novel genes and pathways that may be of relevance for the pathobiology of MCL. We show that copy number neutral loss of heterozygosity (CNN-LOH) is common in MCL and targets regions that are frequently affected by deletions. The molecular consequences of genomic copy number changes appear complex, even in genomic loci with identified tumor suppressors, such as the region 9p21 containing the CDKN2A locus. Moreover, the deregulation of novel genes such as CUL4A, ING1 and MCPH1 may affect the two crucial pathogenetic mechanisms in MCL, the disturbance of the proliferation and DNA damage response pathways. Deregulation of the Hippo pathway may have a pathogenetic role in MCL, since decreased expression of its members MOBKL2A, MOBKL2B and LATS2 was associated with inferior outcome also in an independent validation series of 32 MCL.
Pathway discovery in mantle cell lymphoma by integrated analysis of high-resolution gene expression and copy number profiling.
Disease, Disease stage, Subject
View SamplesFollicular lymphoma (FL) is genetically characterized by the presence of the t(14;18)(q32;q21) chromosomal translocation in approximately 90% of cases. In contrast to FL carrying the t(14;18), their t(14;18)-negative counterparts are less well studied regarding their immunohistochemical, genetic, molecular and clinical features. Within a previously published series of 184 FL grade 1-3A with available gene expression data, we identified 17 FL lacking the t(14;18). Comparative genomic hybridization and high resolution SNP array profiling demonstrated that gains/amplifications of the BCL2 gene locus in 18q were restricted to the t(14;18)-positive FL subgroup. A comparison of gene expression profiles revealed an enrichment of germinal center B-cell associated signatures in t(14;18)-positive FL, whereas activated B-cell like, NFB, proliferation and bystander cell signatures were enriched in t(14;18)-negative FL. These findings were confirmed by immunohistochemistry in an independent validation series of 84 FL, in which 32% of t(14;18)-negative FL showed weak or absent CD10 expression and 91% an increased Ki67 proliferation rate. Although overall survival did not differ between FL with and without t(14;18), our findings suggest distinct molecular features of t(14;18)-negative FL.
Follicular lymphomas with and without translocation t(14;18) differ in gene expression profiles and genetic alterations.
Specimen part, Disease, Disease stage, Subject
View Samples