While advances in genome sequencing technology make population-scale genomics a possibility, current approaches for analysis of these data rely upon parallelization strategies that have limited scalability, complex implementation and lack reproducibility. Churchill, a balanced regional parallelization strategy, overcomes these challenges, fully automating the multiple steps required to go from raw sequencing reads to variant discovery. Through implementation of novel deterministic parallelization techniques, Churchill allows computationally efficient analysis of a high-depth whole genome sample in less than two hours. The method is highly scalable, enabling full analysis of the 1000 Genomes raw sequence dataset in a week using cloud resources. http://churchill.nchri.org/.Electronic supplementary materialThe online version of this article (doi:10.1186/s13059-014-0577-x) contains supplementary material, which is available to authorized users.

Mesenchymal stem/stromal cells (MSCs) are widely studied by both academia and industry for a broad array of clinical indications. The collective body of data provides compelling evidence of the clinical safety of MSC therapy. However, generally accepted proof of therapeutic efficacy has not yet been reported. In an effort to generate a more effective therapeutic cell product, investigators are focused on modifying MSC processing protocols to enhance the intrinsic biologic activity. Here, we report a Good Manufacturing Practice-compliant two-step MSC manufacturing protocol to generate MSCs or interferon c (IFNc) primed MSCs which allows freshly expanded cells to be infused in patients on a predetermined schedule. This protocol eliminates the need to infuse cryopreserved, just thawed cells which may reduce the immune modulatory activity. Moreover, using (IFNc) as a prototypic cytokine, we demonstrate the feasibility of priming the cells with any biologic agent. We then characterized MSCs and IFNc primed MSCs prepared with our protocol, by karyotype, in vitro potential for malignant transformation, biodistribution, effect on engraftment of transplanted hematopoietic cells, and in vivo toxicity in immune deficient mice including a complete post-mortem examination. We found no evidence of toxicity attributable to the MSC or IFNc primed MSCs. Our data suggest that the clinical risk of infusing MSCs or IFNc primed MSCs produced by our two-step protocol is not greater than MSCs currently in practice. While actual proof of safety requires phase I clinical trials, our data support the use of either cell product in new clinical studies. STEM CELLS TRANSLATIONAL MEDICINE 2017;6:1868-1879 SIGNIFICANCE STATEMENTMesenchymal stem/stromal cells (MSCs) are one of the most widely studied cells for the development of cellular therapies. While these cells are unequivocally safe to use in humans, the efficacy of MSCs to treat diseases has not been established. Hence, current efforts are focused on developing the technology to enhance the efficacy of MSCs. Here, we report a novel strategy to prepare MSCs that would mitigate the potential reduction of cell potency observed when infusing freshly thawed, cryopreserved cells. Additionally, we show extensive preclinical data to support the safety of interferon g-primed MSCs, which are designed to enhance the immune modulatory potency of MSCs.

ObjectiveMany genetic studies of intractable epilepsy in pediatric patients primarily focus on inherited, constitutional genetic deficiencies identified in patient blood. Recently, studies have revealed somatic mosaicism associated with epilepsy in which genetic variants are present only in a subset of brain cells. We hypothesize that tissue-specific, somatic mosaicism represents an important genetic etiology in epilepsy and aim to discover somatic alterations in epilepsy-affected brain tissue.MethodsWe have pursued a research study to identify brain somatic mosaicism, using next-generation sequencing (NGS) technologies, in patients with treatment refractory epilepsy who have undergone surgical resection of affected brain tissue.ResultsWe used an integrated combination of NGS techniques and conventional approaches (radiology, histopathology, and electrophysiology) to comprehensively characterize multiple brain regions from a single patient with intractable epilepsy. We present a 3-year-old male patient with West syndrome and intractable tonic seizures in whom we identified a pathogenic frameshift somatic variant in SLC35A2, present at a range of variant allele fractions (4.2%–19.5%) in 12 different brain tissues detected by targeted sequencing. The proportion of the SLC35A2 variant correlated with severity and location of neurophysiology and neuroimaging abnormalities for each tissue.ConclusionsOur findings support the importance of tissue-based sequencing and highlight a correlation in our patient between SLC35A2 variant allele fractions and the severity of epileptogenic phenotypes in different brain tissues obtained from a grid-based resection of clinically defined epileptogenic regions.

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Objective Epilepsy‐associated developmental lesions, including malformations of cortical development and low‐grade developmental tumors, represent a major cause of drug‐resistant seizures requiring surgical intervention in children. Brain‐restricted somatic mosaicism has been implicated in the genetic etiology of these lesions; however, many contributory genes remain unidentified. Methods We enrolled 50 children who were undergoing epilepsy surgery into a translational research study. Resected tissue was divided for clinical neuropathologic evaluation and genomic analysis. We performed exome and RNA sequencing to identify somatic variation and we confirmed our findings using high‐depth targeted DNA sequencing. Results We uncovered candidate disease‐causing somatic variation affecting 28 patients (56%), as well as candidate germline variants affecting 4 patients (8%). In agreement with previous studies, we identified somatic variation affecting solute carrier family 35 member A2 (SLC35A2) and mechanistic target of rapamycin kinase (MTOR) pathway genes in patients with focal cortical dysplasia. Somatic gains of chromosome 1q were detected in 30% (3 of 10) of patients with Type I focal cortical dysplasia (FCD)s. Somatic variation in mitogen‐activated protein kinase (MAPK) pathway genes (i.e., fibroblast growth factor receptor 1 [FGFR1], FGFR2, B‐raf proto‐oncogene, serine/threonine kinase [BRAF], and KRAS proto‐oncogene, GTPase [KRAS]) was associated with low‐grade epilepsy‐associated developmental tumors. RNA sequencing enabled the detection of somatic structural variation that would have otherwise been missed, and which accounted for more than one‐half of epilepsy‐associated tumor diagnoses. Sampling across multiple anatomic regions revealed that somatic variant allele fractions vary widely within epileptogenic tissue. Finally, we identified putative disease‐causing variants in genes not yet associated with focal cortical dysplasia. Significance These results further elucidate the genetic basis of structural brain abnormalities leading to focal epilepsy in children and point to new candidate disease genes.

Summary Recent characterizations of pioneer transcription factors provide insights into their structures and patterns of chromatin recognition associated with their roles in cell fate commitment and transformation. Intersecting with these basic science concepts, identification of pioneer factors (PFs) fused together as driver translocations in childhood cancers raises questions of whether these fusions retain the fundamental ability to invade repressed chromatin, consistent with their monomeric PF constituents. This study defines the cellular and chromatin localization of PAX3-FOXO1, an oncogenic driver of childhood rhabdomyosarcoma (RMS), derived from a fusion of PFs. To quantitatively define its chromatin-targeting functions and capacity to drive epigenetic reprogramming, we developed a ChIP-seq workflow with per-cell normalization (pc-ChIP-seq). Our quantitative localization studies address structural variation in RMS genomes and reveal insights into inactive chromatin localization of PAX3-FOXO1. Taken together, our studies are consistent with pioneer function for a driver oncoprotein in RMS, with repressed chromatin binding and nucleosome-motif targeting.

Typhoid fever is caused primarily by Salmonella enterica serovar Typhi. Approximately 3% to 5% of individuals infected with S. Typhi become chronic carriers with the gallbladder (GB) as the site of persistence, as gallstones within the GB are a platform on which the bacteria form a biofilm. S. Typhi is a human-restricted pathogen; therefore, asymptomatic carriers represent a critical reservoir for further spread of disease. To examine the dynamics of the Salmonella biofilm during chronic carriage, the human gallstone (GS) environment was simulated by growing biofilms on cholesterol-coated surfaces in the presence of bile, and the transcriptional profile was determined. Some of the most highly activated genes corresponded to the curli fimbria operon, with the major structural component csgA upregulated >80-fold. The curli protein polymer is a major component of the extracellular matrix (ECM) in Salmonella biofilms. The upregulation of curli fimbriae by human bile was validated through reverse transcription-quantitative PCR (qRT-PCR), microscopy, and Western blotting. Interestingly, this activation appears human specific, as qRT-PCR showed repression of csgA in biofilms grown in mouse or ox bile. Comparative transcriptional studies of the two divergent csg operons suggest an early activation of both operons in minimal medium complemented with glucose that quickly diminishes as the biofilm matures. However, in the presence of human bile, there is a modest activation of both operons that steadily increases as the biofilm matures. Understanding the effect of the GB environment on key biofilm-associated factors can help target antibiofilm therapeutics or other preventative strategies to eradicate chronic carriage. IMPORTANCE Typhoid fever is caused by Salmonella enterica serovar Typhi, and 3% to 5% of patients become chronic gallbladder (GB) carriers (also known as “Typhoid Marys”). We have previously demonstrated a role for Salmonella biofilm formation on gallstones as a primary mechanism of carriage. In this study, we found that the important biofilm extracellular matrix component curli fimbria is induced in an in vitro human GB model system. This induction is specific to human bile and increases as the biofilm matures. We also found that the biofilm and curli regulator CsgD play a key role in this observed induction. This work further enhances our understanding biofilm-mediated chronic carriage and provides a potential target for eliminating persistent GB infection by S. Typhi.

Nontypeable Haemophilus influenzae (NTHI) is a human-restricted pathogen with an essential requirement for heme–iron acquisition. We previously demonstrated that microevolution of NTHI promotes stationary phase survival in response to transient heme–iron restriction. In this study, we examine the metabolic contributions to biofilm formation using this evolved NTHI strain, RM33. Quantitative analyses identified 29 proteins, 55 transcripts, and 31 metabolites that significantly changed within in vitro biofilms formed by RM33. The synthesis of all enzymes within the tryptophan and glycogen pathways was significantly increased in biofilms formed by RM33 compared with the parental strain. In addition, increases were observed in metabolite transport, adhesin production, and DNA metabolism. Furthermore, we observed pyruvate as a pivotal point in the metabolic pathways associated with changes in cAMP phosphodiesterase activity during biofilm formation. Taken together, changes in central metabolism combined with increased stores of nutrients may serve to counterbalance nutrient sequestration.