215 research outputs found
Significant Correlation Between the Infant Gut Microbiome and Rotavirus Vaccine Response in Rural Ghana
Background. Rotavirus (RV) is the leading cause of diarrhea-related death in children worldwide and 95% of RV-associated deaths occur in Africa and Asia where RV vaccines (RVVs) have lower efficacy. We hypothesize that differences in intestinal microbiome composition correlate with the decreased RVV efficacy observed in poor settings. Methods. We conducted a nested, case-control study comparing prevaccination, fecal microbiome compositions between 6week old, matched RVV responders and nonresponders in rural Ghana. These infants' microbiomes were then compared with 154 age-matched, healthy Dutch infants' microbiomes, assumed to be RVV responders. Fecal microbiome analysis was performed in all groups using the Human Intestinal Tract Chip. Results. We analyzed findings in 78 Ghanaian infants, including 39 RVV responder and nonresponder pairs. The overall microbiome composition was significantly different between RVV responders and nonresponders (FDR, 0.12), and Ghanaian responders were more similar to Dutch infants than nonresponders (P =.002). RVV response correlated with an increased abundance of Streptococcus bovis and a decreased abundance of the Bacteroidetes phylum in comparisons between both Ghanaian RVV responders and nonresponders (FDR, 0.008 vs 0.003) and Dutch infants and Ghanaian nonresponders (FDR, 0.002 vs 0.009). Conclusions. The intestinal microbiome composition correlates significantly with RVV immunogenicity and may contribute to the diminished RVV immunogenicity observed in developing countries.Peer reviewe
Effi cacy of a Russian-backbone live attenuated infl uenza vaccine among children in Senegal: a randomised, double-blind, placebo-controlled trial
Background Live attenuated infl uenza vaccines have been shown to signifi cantly reduce infl uenza in diverse
populations of children, but no effi cacy studies have been done in resource-poor tropical settings. In Senegal, we
assessed the effi cacy and safety of a live attenuated infl uenza vaccine based on Russian-derived master donor viruses
and licensed as a single dose.
Methods In this double-blind, placebo-controlled, parallel group, single-centre trial done near Niakhar, Senegal,
generally healthy children aged 2–5 years were randomly allocated (2:1) to receive a single intranasal dose of masked
trivalent live attenuated infl uenza vaccine or placebo. The allocation sequence was computer-generated by PATH with
block sizes of three. The manufacturer provided vaccine and placebo in coded vials to preserve blinding. Participants
were monitored through the predictable infl uenza season in Senegal for adverse events and signs and symptoms of
infl uenza using weekly home visits and surveillance in clinics. The primary outcome was symptomatic laboratoryconfi
rmed infl uenza caused by any strain and occurring from 15 days post-vaccination to the end of the study. The
primary analysis was per protocol. This study is registered with ClinicalTrials.gov, number NCT01854632.
Findings Between May 23, and July 1, 2013, 1761 children were randomly assigned, 1174 to receive live attenuated
infl uenza vaccine and 587 to receive placebo. The per-protocol set included 1173 vaccinees and 584 placebo recipients
followed up to Dec 20, 2013. Symptomatic infl uenza was laboratory-confi rmed in 210 (18%) of 1173 recipients of live
attenuated infl uenza vaccine and 105 (18%) of placebo recipients, giving a vaccine effi cacy of 0·0% (95% CI –26·4 to 20·9).
Adverse events were balanced between the study groups. Two girls who had received live attenuated infl uenza vaccine
died, one due to anasarca 12 days postvaccination and one due to malnutrition 70 days postvaccination.
Interpretation Live attenuated infl uenza vaccine was well tolerated in young children in Senegal, but did not provide
protection against infl uenza. Further study in such populations, which might experience extended periods of
infl uenza circulation, is warranted
Effi cacy of a Russian-backbone live attenuated infl uenza vaccine among young children in Bangladesh: a randomised, double-blind, placebo-controlled trial
Background The rates of infl uenza illness and associated complications are high among children in Bangladesh.
We assessed the clinical effi cacy and safety of a Russian-backbone live attenuated infl uenza vaccine (LAIV) at two fi eld
sites in Bangladesh.
Methods Between Feb 27 and April 9, 2013, children aged 2–4 years in urban Kamalapur and rural Matlab, Bangladesh,
were randomly assigned in a 2:1 ratio, according to a computer-generated schedule, to receive one intranasal dose of
LAIV or placebo. After vaccination, we monitored children in weekly home visits until Dec 31, 2013, with study clinic
surveillance for infl uenza illness. The primary outcome was symptomatic, laboratory-confi rmed infl uenza illness due
to vaccine-matched strains. Analysis was per protocol. The trial is registered with ClinicalTrials.gov, number
NCT01797029.
Findings Of 1761 children enrolled, 1174 received LAIV and 587 received placebo. Laboratory-confi rmed infl uenza
illness due to vaccine-matched strains was seen in 93 (15·8%) children in the placebo group and 79 (6·7%) in the
LAIV group. Vaccine effi cacy of LAIV for vaccine-matched strains was 57·5% (95% CI 43·6–68·0). The vaccine was
well tolerated, and adverse events were balanced between the groups. The most frequent adverse events were
tachypnoea (n=86 in the LAIV group and n=54 in the placebo group), cough (n=73 and n=43), and runny nose (n=68
and n=39), most of which were mild.
Interpretation This single-dose Russian-backbone LAIV was safe and effi cacious at preventing symptomatic
laboratory-confi rmed infl uenza illness due to vaccine-matched strains. LAIV programmes might reduce the burden
of infl uenza illness in Bangladesh
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Triplication of a 21q22 region contributes to B cell transformation through HMGN1 overexpression and loss of histone H3 lysine 27 trimethylation
Down syndrome confers a 20-fold increased risk of B cell acute lymphoblastic leukemia (B-ALL)1 and polysomy 21 is the most frequent somatic aneuploidy amongst all B-ALLs2. Yet, the mechanistic links between chr.21 triplication and B-ALL remain undefined. Here we show that germline triplication of only 31 genes orthologous to human chr.21q22 confers murine progenitor B cell self-renewal in vitro, maturation defects in vivo, and B-ALL with either BCR-ABL or CRLF2 with activated JAK2. Chr.21q22 triplication suppresses H3K27me3 in progenitor B cells and B-ALLs, and “bivalent” genes with both H3K27me3 and H3K4me3 at their promoters in wild-type progenitor B cells are preferentially overexpressed in triplicated cells. Strikingly, human B-ALLs with polysomy 21 are distinguished by their overexpression of genes marked with H3K27me3 in multiple cell types. Finally, overexpression of HMGN1, a nucleosome remodeling protein encoded on chr.21q223–5, suppresses H3K27me3 and promotes both B cell proliferation in vitro and B-ALL in vivo
Fine-Scale Genetic Structure Arises during Range Expansion of an Invasive Gecko
Processes of range expansion are increasingly important in light of current concerns about invasive species and range shifts due to climate change. Theoretical studies suggest that genetic structuring may occur during range expansion. Ephemeral genetic structure can have important evolutionary implications, such as propagating genetic changes along the wave front of expansion, yet few studies have shown evidence of such structure. We tested the hypothesis that genetic structure arises during range expansion in Hemidactylus mabouia, a nocturnal African gecko recently introduced to Florida, USA. Twelve highly variable microsatellite loci were used to screen 418 individuals collected from 43 locations from four sampling sites across Florida, representing a gradient from earlier (∼1990s) to very recent colonization. We found earlier colonized locations had little detectable genetic structure and higher allelic richness than more recently colonized locations. Genetic structuring was pronounced among locations at spatial scales of tens to hundreds of meters near the leading edge of range expansion. Despite the rapid pace of range expansion in this introduced gecko, dispersal is limited among many suitable habitat patches. Fine-scale genetic structure is likely the result of founder effects during colonization of suitable habitat patches. It may be obscured over time and by scale-dependent modes of dispersal. Further studies are needed to determine if such genetic structure affects adaptation and trait evolution in range expansions and range shifts
Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas
This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing
molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin
Pan-cancer Alterations of the MYC Oncogene and Its Proximal Network across the Cancer Genome Atlas
Although theMYConcogene has been implicated incancer, a systematic assessment of alterations ofMYC, related transcription factors, and co-regulatoryproteins, forming the proximal MYC network (PMN),across human cancers is lacking. Using computa-tional approaches, we define genomic and proteo-mic features associated with MYC and the PMNacross the 33 cancers of The Cancer Genome Atlas.Pan-cancer, 28% of all samples had at least one ofthe MYC paralogs amplified. In contrast, the MYCantagonists MGA and MNT were the most frequentlymutated or deleted members, proposing a roleas tumor suppressors.MYCalterations were mutu-ally exclusive withPIK3CA,PTEN,APC,orBRAFalterations, suggesting that MYC is a distinct onco-genic driver. Expression analysis revealed MYC-associated pathways in tumor subtypes, such asimmune response and growth factor signaling; chro-matin, translation, and DNA replication/repair wereconserved pan-cancer. This analysis reveals insightsinto MYC biology and is a reference for biomarkersand therapeutics for cancers with alterations ofMYC or the PMN
Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context
Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts
Spatial Organization and Molecular Correlation of Tumor-Infiltrating Lymphocytes Using Deep Learning on Pathology Images
Beyond sample curation and basic pathologic characterization, the digitized H&E-stained images
of TCGA samples remain underutilized. To highlight this resource, we present mappings of tumorinfiltrating lymphocytes (TILs) based on H&E images from 13 TCGA tumor types. These TIL
maps are derived through computational staining using a convolutional neural network trained to
classify patches of images. Affinity propagation revealed local spatial structure in TIL patterns and
correlation with overall survival. TIL map structural patterns were grouped using standard
histopathological parameters. These patterns are enriched in particular T cell subpopulations
derived from molecular measures. TIL densities and spatial structure were differentially enriched
among tumor types, immune subtypes, and tumor molecular subtypes, implying that spatial
infiltrate state could reflect particular tumor cell aberration states. Obtaining spatial lymphocytic
patterns linked to the rich genomic characterization of TCGA samples demonstrates one use for
the TCGA image archives with insights into the tumor-immune microenvironment
Spermatogenesis-Specific Features of the Meiotic Program in Caenorhabditis elegans
In most sexually reproducing organisms, the fundamental process of meiosis is implemented concurrently with two differentiation programs that occur at different rates and generate distinct cell types, sperm and oocytes. However, little is known about how the meiotic program is influenced by such contrasting developmental programs. Here we present a detailed timeline of late meiotic prophase during spermatogenesis in Caenorhabditis elegans using cytological and molecular landmarks to interrelate changes in chromosome dynamics with germ cell cellularization, spindle formation, and cell cycle transitions. This analysis expands our understanding C. elegans spermatogenesis, as it identifies multiple spermatogenesis-specific features of the meiotic program and provides a framework for comparative studies. Post-pachytene chromatin of spermatocytes is distinct from that of oocytes in both composition and morphology. Strikingly, C. elegans spermatogenesis includes a previously undescribed karyosome stage, a common but poorly understood feature of meiosis in many organisms. We find that karyosome formation, in which chromosomes form a constricted mass within an intact nuclear envelope, follows desynapsis, involves a global down-regulation of transcription, and may support the sequential activation of multiple kinases that prepare spermatocytes for meiotic divisions. In spermatocytes, the presence of centrioles alters both the relative timing of meiotic spindle assembly and its ultimate structure. These microtubule differences are accompanied by differences in kinetochores, which connect microtubules to chromosomes. The sperm-specific features of meiosis revealed here illuminate how the underlying molecular machinery required for meiosis is differentially regulated in each sex
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