251 research outputs found
CRLF2 rearrangement in Ph-like acute lymphoblastic leukemia predicts relative glucocorticoid resistance that is overcome with MEK or Akt inhibition.
Philadelphia chromosome-like (Ph-like) acute lymphoblastic leukemia (ALL) is a genetically heterogeneous subtype of B-cell ALL characterized by chromosomal rearrangements and mutations that result in aberrant cytokine receptor and kinase signaling. In particular, chromosomal rearrangements resulting in the overexpression of cytokine receptor-like factor 2 (CRLF2) occur in 50% of Ph-like ALL cases. CRLF2 overexpression is associated with particularly poor clinical outcomes, though the molecular basis for this is currently unknown. Glucocorticoids (GCs) are integral to the treatment of ALL and GC resistance at diagnosis is an important negative prognostic factor. Given the importance of GCs in ALL therapy and the poor outcomes for patients with CRLF2 overexpression, we hypothesized that the aberrant signal transduction associated with CRLF2 overexpression might mediate intrinsic GC insensitivity. To test this hypothesis, we exposed Ph-like ALL cells from patient-derived xenografts to GCs and found that CRLF2 rearranged (CRLF2R) leukemias uniformly demonstrated reduced GC sensitivity in vitro. Furthermore, targeted inhibition of signal transduction with the MEK inhibitor trametinib and the Akt inhibitor MK2206, but not the JAK inhibitor ruxolitinib, was sufficient to augment GC sensitivity. These data suggest that suboptimal GC responses may in part underlie the poor clinical outcomes for patients with CRLF2 overexpression and provide rationale for combination therapy involving GCs and signal transduction inhibitors as a means of enhancing GC efficacy
Can we accelerate autism discoveries through crowdsourcing?
AbstractAutism is a dramatically expanding public health challenge. The search for genomic variants underlying the disease concomitantly accelerated over the last 5 years, leading to a general consensus that genetics can explain between 40% and 60% of the symptomatic variability seen in autism. This stresses both an urgent need to continue devoting resources to the search for genetic etiologies that define the forms of autism, and an equal need for attention to the interactive roles of the environment. While some environmental factors have been investigated, few studies have attempted to elucidate the combination and interplay between gene and environment to gain clear understanding of the mechanisms by which environmental factors interact with genetic susceptibilities in Autism Spectrum Disorder. Due to financial constraints as well as recruitment protocols limited by geography, such studies have been challenging to implement. We discuss here how crowdsourcing approaches can overcome these limitations
Identification of active oxalotrophic bacteria by Bromodeoxyuridine DNA labeling in a microcosm soil experiments
The oxalate-carbonate pathway (OCP) leads to a potential carbon sink in terrestrial environments. This process is linked to the activity of oxalotrophic bacteria. Although isolation and molecular characterizations are used to study oxalotrophic bacteria, these approaches do not give information on the active oxalotrophs present in soil undergoing the OCP. The aim of this study was to assess the diversity of active oxalotrophic bacteria in soil microcosms using the Bromodeoxyuridine (BrdU) DNA labeling technique. Soil was collected near an oxalogenic tree (Milicia excelsa). Different concentrations of calcium oxalate (0.5%, 1%, and 4% w/w) were added to the soil microcosms and compared with an untreated control. After 12 days of incubation, a maximal pH of 7.7 was measured for microcosms with oxalate (initial pH 6.4). At this time point, a DGGE profile of the frc gene was performed from BrdU-labeled soil DNA and unlabeled soil DNA. Actinobacteria (Streptomyces- and Kribbella-like sequences), Gammaproteobacteria and Betaproteobacteria were found as the main active oxalotrophic bacterial groups. This study highlights the relevance of Actinobacteria as members of the active bacterial community and the identification of novel uncultured oxalotrophic groups (i.e. Kribbella) active in soil
FOAM (functional ontology assignments for metagenomes):a hidden markov model (HMM) database with environmental focus
A new functional gene database, FOAM (Functional Ontology Assignments for Metagenomes), was developed to screen environmental metagenomic sequence datasets. FOAM provides a new functional ontology dedicated to classify gene functions relevant to environmental microorganisms based on Hidden Markov Models (HMMs). Sets of aligned protein sequences (i.e. ‘profiles’) were tailored to a large group of target KEGG Orthologs (KOs) from which HMMs were trained. The alignments were checked and curated to make them specific to the targeted KO. Within this process, sequence profiles were enriched with the most abundant sequences available to maximize the yield of accurate classifier models. An associated functional ontology was built to describe the functional groups and hierarchy. FOAM allows the user to select the target search space before HMM-based comparison steps and to easily organize the results into different functional categories and subcategories. FOAM is publicly available at http://portal.nersc.gov/project/m1317/FOAM/
Structured diet and exercise guidance in pregnancy to improve health in women and their offspring: study protocol for the Be Healthy in Pregnancy (BHIP) randomized controlled trial
BackgroundEvidence from epidemiological and animal studies support the concept of programming fetal, neonatal, and adult health in response to in utero exposures such as maternal obesity and lifestyle variables. Excess gestational weight gain (GWG), maternal physical activity, and sub-optimal and excess nutrition during pregnancy may program the offspring\u27s risk of obesity. Maternal intake of dairy foods rich in high-quality proteins, calcium, and vitamin D may influence later bone health status. Current clinical practice guidelines for managing GWG are not founded on randomized trials and lack specific active intervention ingredients. The Be Healthy in Pregnancy (BHIP) study is a randomized controlled trial (RCT) designed to test the effectiveness of a novel structured and monitored Nutrition + Exercise intervention in pregnant women of all pre-pregnancy weight categories (except extreme obesity), delivered through prenatal care in community settings (rather than in hospital settings), on the likelihood of women achieving recommended GWG and a benefit to bone status of offspring and mother at birth and sixmonths postpartum.MethodsThe BHIP study is a two-site RCT that will recruit up to 242 participants aged \u3e18years at 12-17 weeks of gestation. After baseline measures, participants are randomized to either a structured and monitored Nutrition + Exercise (intervention) or usual care (control) program for the duration of their pregnancy. The primary outcome of the study is the percent of women who achieve GWG within the Institute of Medicine (IOM) guidelines. The secondary outcomes include: (1) maternal bone status via blood bone biomarkers during pregnancy; (2) infant bone status in cord blood; (3) mother and infant bone status measured by dual-energy absorptiometry scanning (DXA scan) at sixmonths postpartum; (4) other measures including maternal blood pressure, blood glucose and lipid profiles, % body fat, and postpartum weight retention; and (5) infant weight z-scores and fat mass at sixmonths of age.DiscussionIf effective, this RCT will generate high-quality evidence to refine the nutrition guidelines during pregnancy to improve the likelihood of women achieving recommended GWG. It will also demonstrate the importance of early nutrition on bone health in the offspring
Role of mass drug administration in elimination of Plasmodium falciparum malaria: a consensus modelling study
Background Mass drug administration for elimination of Plasmodium falciparum malaria is recommended by WHO
in some settings. We used consensus modelling to understand how to optimise the effects of mass drug administration
in areas with low malaria transmission.
Methods We collaborated with researchers doing field trials to establish a standard intervention scenario and
standard transmission setting, and we input these parameters into four previously published models. We then
varied the number of rounds of mass drug administration, coverage, duration, timing, importation of infection, and
pre-administration transmission levels. The outcome of interest was the percentage reduction in annual mean
prevalence of P falciparum parasite rate as measured by PCR in the third year after the final round of mass drug
administration.
Findings The models predicted differing magnitude of the effects of mass drug administration, but consensus
answers were reached for several factors. Mass drug administration was predicted to reduce transmission over a
longer timescale than accounted for by the prophylactic effect alone. Percentage reduction in transmission was
predicted to be higher and last longer at lower baseline transmission levels. Reduction in transmission resulting from
mass drug administration was predicted to be temporary, and in the absence of scale-up of other interventions, such
as vector control, transmission would return to pre-administration levels. The proportion of the population treated in
a year was a key determinant of simulated effectiveness, irrespective of whether people are treated through high
coverage in a single round or new individuals are reached by implementation of several rounds. Mass drug
administration was predicted to be more effective if continued over 2 years rather than 1 year, and if done at the time
of year when transmission is lowest.
Interpretation Mass drug administration has the potential to reduce transmission for a limited time, but is not an
effective replacement for existing vector control. Unless elimination is achieved, mass drug administration has to be
repeated regularly for sustained effect
CMB-S4 Science Book, First Edition
This book lays out the scientific goals to be addressed by the
next-generation ground-based cosmic microwave background experiment, CMB-S4,
envisioned to consist of dedicated telescopes at the South Pole, the high
Chilean Atacama plateau and possibly a northern hemisphere site, all equipped
with new superconducting cameras. CMB-S4 will dramatically advance cosmological
studies by crossing critical thresholds in the search for the B-mode
polarization signature of primordial gravitational waves, in the determination
of the number and masses of the neutrinos, in the search for evidence of new
light relics, in constraining the nature of dark energy, and in testing general
relativity on large scales
Targeting of Aberrant αvβ6 Integrin Expression in Solid Tumors Using Chimeric Antigen Receptor-Engineered T Cells.
Expression of the αvβ6 integrin is upregulated in several solid tumors. In contrast, physiologic expression of this epithelial-specific integrin is restricted to development and epithelial re-modeling. Here, we describe, for the first time, the development of a chimeric antigen receptor (CAR) that couples the recognition of this integrin to the delivery of potent therapeutic activity in a diverse repertoire of solid tumor models. Highly selective targeting αvβ6 was achieved using a foot and mouth disease virus-derived A20 peptide, coupled to a fused CD28+CD3 endodomain. To achieve selective expansion of CAR T cells ex vivo, an IL-4-responsive fusion gene (4αβ) was co-expressed, which delivers a selective mitogenic signal to engineered T cells only. In vivo efficacy was demonstrated in mice with established ovarian, breast, and pancreatic tumor xenografts, all of which express αvβ6 at intermediate to high levels. SCID beige mice were used for these studies because they are susceptible to cytokine release syndrome, unlike more immune-compromised strains. Nonetheless, although the CAR also engages mouse αvβ6, mild and reversible toxicity was only observed when supra-therapeutic doses of CAR T cells were administered parenterally. These data support the clinical evaluation of αvβ6 re-targeted CAR T cell immunotherapy in solid tumors that express this integrin
Hypoxia-inducible factor 1 alpha-mediated RelB/APOBEC3B down-regulation allows hepatitis B virus persistence
Background and Aims: Therapeutic strategies against HBV focus, among others, on the activation of the immune system to enable the infected host to eliminate HBV. Hypoxia‐inducible factor 1 alpha (HIF1α) stabilization has been associated with impaired immune responses. HBV pathogenesis triggers chronic hepatitis‐related scaring, leading inter alia to modulation of liver oxygenation and transient immune activation, both factors playing a role in HIF1α stabilization.
Approach and Results: We addressed whether HIF1α interferes with immune‐mediated induction of the cytidine deaminase, apolipoprotein B mRNA editing enzyme catalytic subunit 3B (APOBEC3B; A3B), and subsequent covalently closed circular DNA (cccDNA) decay. Liver biopsies of chronic HBV (CHB) patients were analyzed by immunohistochemistry and in situ hybridization. The effect of HIF1α induction/stabilization on differentiated HepaRG or mice ± HBV ± LTβR‐agonist (BS1) was assessed in vitro and in vivo. Induction of A3B and subsequent effects were analyzed by RT‐qPCR, immunoblotting, chromatin immunoprecipitation, immunocytochemistry, and mass spectrometry. Analyzing CHB highlighted that areas with high HIF1α levels and low A3B expression correlated with high HBcAg, potentially representing a reservoir for HBV survival in immune‐active patients. In vitro, HIF1α stabilization strongly impaired A3B expression and anti‐HBV effect. Interestingly, HIF1α knockdown was sufficient to rescue the inhibition of A3B up‐regulation and ‐mediated antiviral effects, whereas HIF2α knockdown had no effect. HIF1α stabilization decreased the level of v‐rel reticuloendotheliosis viral oncogene homolog B protein, but not its mRNA, which was confirmed in vivo. Noteworthy, this function of HIF1α was independent of its partner, aryl hydrocarbon receptor nuclear translocator.
Conclusions: In conclusion, inhibiting HIF1α expression or stabilization represents an anti‐HBV strategy in the context of immune‐mediated A3B induction. High HIF1α, mediated by hypoxia or inflammation, offers a reservoir for HBV survival in vivo and should be considered as a restricting factor in the development of immune therapies
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