Immunosuppression is needed in HLA identical sibling renal transplantation. We conducted a tolerance trial in this patient cohort using Alemtuzumab induction, donor hematopoietic stem cells, tacrolimus/mycophenolate immunosuppression converted to sirolimus, planning complete drug withdrawal by 24 months post-transplantation. After an additional 12 months with no immunosuppression, normal biopsies and renal function, recipients were considered tolerant. Twenty recipients were enrolled. Of the first 10 (>36 months post-transplantation), 5 had immunosuppression successfully withdrawn for 16-36 months (tolerant), 2 had disease recurrence and 3 had subclinical rejection in protocol biopsies (non-tolerant). Microchimerism disappeared after 1 year, and CD4+CD25highCD127-FOXP3+ T cells and CD19+IgD/M+CD27- B cells increased to 5 years post-transplantation in both groups, whereas immune/inflammatory gene expression pathways in the peripheral blood and urine were differentially downregulated in tolerant compared to non-tolerant recipients. Therefore, in this HLA identical renal transplant tolerance trial, absent chimerism, Treg and Breg immunophenotypes were indistinguishable between tolerant and non-tolerant recipients, but global genomic changes indicating immunomodulation were observed only in tolerant recipients.
Genomic biomarkers correlate with HLA-identical renal transplant tolerance.
Specimen part, Time
View SamplesQuiescent stem cells of glioblastoma (GBM), a malignant primary brain tumor, are potential sources for recurrence after therapy. However, the gene expression program underlying the physiology of GBM stem cells remains unclear. We have isolated quiescent GBM cells by engineering them with a knock-in H2B-GFP proliferation reporter and expanding them in a 3D tumor organoid model that mimics tumor heterogeneity. H2B-GFP label retaining quiescent cells were subjected to stem cell assays and RNA-Seq gene expression analysis. While quiescent GBM cells were similar in clonal culture assays to their proliferative counterparts, they displayed higher therapy resistance. Interestingly, quiescent GBM cells upregulated epithelial-mesenchymal transition (EMT) genes and genes of extracellular matrix components. Our findings connect quiescent GBM cells with an EMT-like shift, possibly explaining how GBM stem cells achieve high therapy resistance and invasiveness, and suggest new targets to abrogate GBM. Overall design: Glioblastoma cancer cells in 3D organoid culture were pulsed for 2 weeks with H2B-GFP, then chased either 2 or 4 weeks. Label-retaining GFP-high cells (quiescent) were separated from bulk population, and both populations were analyzed by RNA-Seq.
Gene signatures of quiescent glioblastoma cells reveal mesenchymal shift and interactions with niche microenvironment.
Specimen part, Subject
View SamplesPrimary human foreskin fibroblasts (HFF) were exposed to either salt stress (80mM KCl) or heat stress (44ºC). Newly transcribed RNA was labelled by adding 500µM 4-thiouridine (4sU) to the cell culture media for 1h. Total cellular RNA was isolated using Trizol. Newly transcribed RNA was purified following the protocol described in Raedle et al. JoVE 2013. Overall design: Newly transcribed RNA was labelled in one hour intervals during either salt or heat stress (prior to stress, 0-1h or 1-2h). All 4sU-RNA samples were sent for sequencing. Two independent biological replicates were analysed.
HSV-1-induced disruption of transcription termination resembles a cellular stress response but selectively increases chromatin accessibility downstream of genes.
Specimen part, Subject, Time
View SamplesRationale: Interstitial fibrosis and tubular atrophy (IFTA) is found in ~25% of 1-year biopsies post-transplant(1, 2). It correlates with decreased graft survival when histological evidence of inflammation is present.(3-5) Identifying the etiology of IFTA is important because longterm graft survival has not changed as expected given improved therapies and a dramatically reduced incidence of acute rejection.(6-8) Methods: Gene expression profiles of 234 samples were obtained with matching clinical and outcome data (7 transplant centers). 81 IFTA samples were divided into subphenotypes by the degree of inflammation on histology: IFTA with acute rejection (AR), IFTA with inflammation and IFTA without inflammation. Samples with AR (n=54) and normally functioning transplants (TX; n=99) were used in comparisons. Conclusions: Gene expression profiling of all IFTA phenotypes were strongly enriched for cAR gene dysregulation pathways, including IFTA samples without histological evidence of inflammation. Thus, by molecular profiling we demonstrate that most IFTA samples have ongoing immune-mediated injury or chronic rejection that is more sensitively detected by gene expression profiling. We also found that the relative expression of AR-affiliated genes correlated with future graft loss in IFTA samples without inflammation. We conclude that undetected and/or undertreated immune rejection is leading to IFTA and graft failure.
Gene Expression in Biopsies of Acute Rejection and Interstitial Fibrosis/Tubular Atrophy Reveals Highly Shared Mechanisms That Correlate With Worse Long-Term Outcomes.
Specimen part, Disease, Disease stage
View SamplesPrimary human foreskin fibroblasts (HFF) were infected with wild-type simplex virus 1 (HSV-1) strain 17 at a multiplicity of infection (MOI) of 10. Newly transcribed RNA was labelled by adding 500µM 4-thiouridine (4sU) to the cell culture media for 1h. Total cellular RNA was isolated using Trizol. Newly transcribed RNA was purified following the protocol described in Raedle et al. JoVE 2013. Overall design: Newly transcribed RNA was labelled in one hour intervals during the first eight hours of HSV-1 infection. All nine 4sU-RNA samples as well as total cellular RNA of every second hour of infection were sent for sequencing. Two independent biological replicates were analysed.
Prediction of Poly(A) Sites by Poly(A) Read Mapping.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Development and clinical validity of a novel blood-based molecular biomarker for subclinical acute rejection following kidney transplant.
Specimen part
View SamplesSub-clinical acute rejection (subAR) in kidney transplant recipients (KTR) leads to chronic rejection and graft loss. Non-invasive biomarkers are needed to detect subAR. 307 KTR were enrolled into a multi-center observational study. Precise clinical phenotypes (CP) were used to define subAR. Differential gene expression (DGE) data from peripheral blood samples paired with surveillance biopsies were used to train a Random Forests (RF) model to develop a gene expression profile (GEP) for subAR. A separate cohort of paired samples was used to validate the GEP. Clinical endpoints and gene pathway mapping were used to assess clinical validity and biologic relevance. DGE data from 530 samples (130 subAR) collected from 250 KTR yielded a RF model: AUC 0.85; 0.84 after internal validation with bootstrap resampling. We selected a predicted probability threshold favoring specificity and NPV (87% and 88%) over sensitivity and PPV (64% and 61%, respectively). We tested the locked model/threshold on a separate cohort of 138 KTR undergoing surveillance biopsies at our institution (rejection 42; no rejection 96): NPV 78%; PPV 51%; AUC 0.66. Both the CP and GEP of subAR within the first 12 months following transplantation were independently associated with worse graft outcomes at 24 months, including de novo donor-specific antibody (DSA). Serial GEP tracked with response to treatment of subAR. DGE data from both cohorts mapped to gene pathways indicative of allograft rejection.
Development and clinical validity of a novel blood-based molecular biomarker for subclinical acute rejection following kidney transplant.
Specimen part
View SamplesSub-clinical acute rejection (subAR) in kidney transplant recipients (KTR) leads to chronic rejection and graft loss. Non-invasive biomarkers are needed to detect subAR. 307 KTR were enrolled into a multi-center observational study. Precise clinical phenotypes (CP) were used to define subAR. Differential gene expression (DGE) data from peripheral blood samples paired with surveillance biopsies were used to train a Random Forests (RF) model to develop a gene expression profile (GEP) for subAR. A separate cohort of paired samples was used to validate the GEP. Clinical endpoints and gene pathway mapping were used to assess clinical validity and biologic relevance. DGE data from 530 samples (130 subAR) collected from 250 KTR yielded a RF model: AUC 0.85; 0.84 after internal validation with bootstrap resampling. We selected a predicted probability threshold favoring specificity and NPV (87% and 88%) over sensitivity and PPV (64% and 61%, respectively). We tested the locked model/threshold on a separate cohort of 138 KTR undergoing surveillance biopsies at our institution (rejection 42; no rejection 96): NPV 78%; PPV 51%; AUC 0.66. Both the CP and GEP of subAR within the first 12 months following transplantation were independently associated with worse graft outcomes at 24 months, including de novo donor-specific antibody (DSA). Serial GEP tracked with response to treatment of subAR. DGE data from both cohorts mapped to gene pathways indicative of allograft rejection.
Development and clinical validity of a novel blood-based molecular biomarker for subclinical acute rejection following kidney transplant.
No sample metadata fields
View SamplesIn the present work, we have used whole genome expression profiling of peripheral blood samples from 51 patients with biopsy-proven acute kidney transplant rejection and 24 patients with excellent function and biopsy-proven normal transplant histology. The results demonstrate that there are 1738 probesets on the Affymetrix HG-U133 Plus 2.0 GeneChip representing 1472 unique genes which are differentially expressed in the peripheral blood during an acute kidney transplant rejection. By ranking these results we have identified minimal sets of 50 to 150 probesets with predictive classification accuracies for AR of greater than 90% established with several different prediction tools including DLDA and PAM. We have demonstrated that a subset of peripheral blood gene expression signatures can also diagnose four different subtypes of AR (Banff Borderline, IA, IB and IIA) and the top 100 ranked classifiers have greater than 89% predictive accuracy. Finally, we have demonstrated that there are gene signatures for early and late AR defined as less than or greater than one year post-transplant with greater than 86% predictive accuracies. We also confirmed that there are 439 time-independent gene classifiers for AR. Based on these results, we conclude that peripheral blood gene expression profiling can be used to diagnose AR at any time in the first 5 years post-transplant in the setting of acute kidney transplant dysfunction not caused by BK nephropathy, other infections, drug-induced nephrotoxicity or ureteral obstruction.
Molecular classifiers for acute kidney transplant rejection in peripheral blood by whole genome gene expression profiling.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Conserved principles of mammalian transcriptional regulation revealed by RNA half-life.
No sample metadata fields
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