Little is known about the biochemical environment in phagosomes harboring an infectious agent. To assess the state of this organelle we captured the transcriptional responses of Mycobacterium tuberculosis (MTB) in macrophages from wild-type and nitric oxide (NO) synthase 2-deficient mice before and after immunologic activation. The intraphagosomal transcriptome was compared with the transcriptome of MTB in standard broth culture and during growth in diverse conditions designed to simulate features of the phagosomal environment. Genes expressed differentially as a consequence of intraphagosomal residence included an interferon gamma- and NO-induced response that intensifies an iron-scavenging program, converts the microbe from aerobic to anaerobic respiration, and induces a dormancy regulon. Induction of genes involved in the activation and beta-oxidation of fatty acids indicated that fatty acids furnish carbon and energy. Induction of sigmaE-dependent, sodium dodecyl sulfate-regulated genes and genes involved in mycolic acid modification pointed to damage and repair of the cell envelope. Sentinel genes within the intraphagosomal transcriptome were induced similarly by MTB in the lungs of mice. The microbial transcriptome thus served as a bioprobe of the MTB phagosomal environment, showing it to be nitrosative, oxidative, functionally hypoxic, carbohydrate poor, and capable of perturbing the pathogen's cell envelope.

BACKGROUND

The Global Burden of Disease, Injuries, and Risk Factor study 2013 (GBD 2013) is the first of a series of annual updates of the GBD. Risk factor quantification, particularly of modifiable risk factors, can help to identify emerging threats to population health and opportunities for prevention. The GBD 2013 provides a timely opportunity to update the comparative risk assessment with new data for exposure, relative risks, and evidence on the appropriate counterfactual risk distribution.

METHODS

Attributable deaths, years of life lost, years lived with disability, and disability-adjusted life-years (DALYs) have been estimated for 79 risks or clusters of risks using the GBD 2010 methods. Risk-outcome pairs meeting explicit evidence criteria were assessed for 188 countries for the period 1990-2013 by age and sex using three inputs: risk exposure, relative risks, and the theoretical minimum risk exposure level (TMREL). Risks are organised into a hierarchy with blocks of behavioural, environmental and occupational, and metabolic risks at the first level of the hierarchy. The next level in the hierarchy includes nine clusters of related risks and two individual risks, with more detail provided at levels 3 and 4 of the hierarchy. Compared with GBD 2010, six new risk factors have been added: handwashing practices, occupational exposure to trichloroethylene, childhood wasting, childhood stunting, unsafe sex, and low glomerular filtration rate. For most risks, data for exposure were synthesised with a Bayesian meta-regression method, DisMod-MR 2.0, or spatial-temporal Gaussian process regression. Relative risks were based on meta-regressions of published cohort and intervention studies. Attributable burden for clusters of risks and all risks combined took into account evidence on the mediation of some risks such as high body-mass index (BMI) through other risks such as high systolic blood pressure and high cholesterol.

RESULTS

All risks combined account for 57·2% (95% uncertainty interval [UI] 55·8-58·5) of deaths and 41·6% (40·1-43·0) of DALYs. Risks quantified account for 87·9% (86·5-89·3) of cardiovascular disease DALYs, ranging to a low of 0% for neonatal disorders and neglected tropical diseases and malaria. In terms of global DALYs in 2013, six risks or clusters of risks each caused more than 5% of DALYs: dietary risks accounting for 11·3 million deaths and 241·4 million DALYs, high systolic blood pressure for 10·4 million deaths and 208·1 million DALYs, child and maternal malnutrition for 1·7 million deaths and 176·9 million DALYs, tobacco smoke for 6·1 million deaths and 143·5 million DALYs, air pollution for 5·5 million deaths and 141·5 million DALYs, and high BMI for 4·4 million deaths and 134·0 million DALYs. Risk factor patterns vary across regions and countries and with time. In sub-Saharan Africa, the leading risk factors are child and maternal malnutrition, unsafe sex, and unsafe water, sanitation, and handwashing. In women, in nearly all countries in the Americas, north Africa, and the Middle East, and in many other high-income countries, high BMI is the leading risk factor, with high systolic blood pressure as the leading risk in most of Central and Eastern Europe and south and east Asia. For men, high systolic blood pressure or tobacco use are the leading risks in nearly all high-income countries, in north Africa and the Middle East, Europe, and Asia. For men and women, unsafe sex is the leading risk in a corridor from Kenya to South Africa.

CONCLUSIONS

Behavioural, environmental and occupational, and metabolic risks can explain half of global mortality and more than one-third of global DALYs providing many opportunities for prevention. Of the larger risks, the attributable burden of high BMI has increased in the past 23 years. In view of the prominence of behavioural risk factors, behavioural and social science research on interventions for these risks should be strengthened. Many prevention and primary care policy options are available now to act on key risks.

BACKGROUND

Bill & Melinda Gates Foundation.

BACKGROUND

The Global Burden of Disease Study 2013 (GBD 2013) aims to bring together all available epidemiological data using a coherent measurement framework, standardised estimation methods, and transparent data sources to enable comparisons of health loss over time and across causes, age-sex groups, and countries. The GBD can be used to generate summary measures such as disability-adjusted life-years (DALYs) and healthy life expectancy (HALE) that make possible comparative assessments of broad epidemiological patterns across countries and time. These summary measures can also be used to quantify the component of variation in epidemiology that is related to sociodemographic development.

METHODS

We used the published GBD 2013 data for age-specific mortality, years of life lost due to premature mortality (YLLs), and years lived with disability (YLDs) to calculate DALYs and HALE for 1990, 1995, 2000, 2005, 2010, and 2013 for 188 countries. We calculated HALE using the Sullivan method; 95% uncertainty intervals (UIs) represent uncertainty in age-specific death rates and YLDs per person for each country, age, sex, and year. We estimated DALYs for 306 causes for each country as the sum of YLLs and YLDs; 95% UIs represent uncertainty in YLL and YLD rates. We quantified patterns of the epidemiological transition with a composite indicator of sociodemographic status, which we constructed from income per person, average years of schooling after age 15 years, and the total fertility rate and mean age of the population. We applied hierarchical regression to DALY rates by cause across countries to decompose variance related to the sociodemographic status variable, country, and time.

RESULTS

Worldwide, from 1990 to 2013, life expectancy at birth rose by 6·2 years (95% UI 5·6-6·6), from 65·3 years (65·0-65·6) in 1990 to 71·5 years (71·0-71·9) in 2013, HALE at birth rose by 5·4 years (4·9-5·8), from 56·9 years (54·5-59·1) to 62·3 years (59·7-64·8), total DALYs fell by 3·6% (0·3-7·4), and age-standardised DALY rates per 100 000 people fell by 26·7% (24·6-29·1). For communicable, maternal, neonatal, and nutritional disorders, global DALY numbers, crude rates, and age-standardised rates have all declined between 1990 and 2013, whereas for non-communicable diseases, global DALYs have been increasing, DALY rates have remained nearly constant, and age-standardised DALY rates declined during the same period. From 2005 to 2013, the number of DALYs increased for most specific non-communicable diseases, including cardiovascular diseases and neoplasms, in addition to dengue, food-borne trematodes, and leishmaniasis; DALYs decreased for nearly all other causes. By 2013, the five leading causes of DALYs were ischaemic heart disease, lower respiratory infections, cerebrovascular disease, low back and neck pain, and road injuries. Sociodemographic status explained more than 50% of the variance between countries and over time for diarrhoea, lower respiratory infections, and other common infectious diseases; maternal disorders; neonatal disorders; nutritional deficiencies; other communicable, maternal, neonatal, and nutritional diseases; musculoskeletal disorders; and other non-communicable diseases. However, sociodemographic status explained less than 10% of the variance in DALY rates for cardiovascular diseases; chronic respiratory diseases; cirrhosis; diabetes, urogenital, blood, and endocrine diseases; unintentional injuries; and self-harm and interpersonal violence. Predictably, increased sociodemographic status was associated with a shift in burden from YLLs to YLDs, driven by declines in YLLs and increases in YLDs from musculoskeletal disorders, neurological disorders, and mental and substance use disorders. In most country-specific estimates, the increase in life expectancy was greater than that in HALE. Leading causes of DALYs are highly variable across countries.

CONCLUSIONS

Global health is improving. Population growth and ageing have driven up numbers of DALYs, but crude rates have remained relatively constant, showing that progress in health does not mean fewer demands on health systems. The notion of an epidemiological transition--in which increasing sociodemographic status brings structured change in disease burden--is useful, but there is tremendous variation in burden of disease that is not associated with sociodemographic status. This further underscores the need for country-specific assessments of DALYs and HALE to appropriately inform health policy decisions and attendant actions.

BACKGROUND

Bill & Melinda Gates Foundation.

BACKGROUND

The fifth Millennium Development Goal (MDG 5) established the goal of a 75% reduction in the maternal mortality ratio (MMR; number of maternal deaths per 100,000 livebirths) between 1990 and 2015. We aimed to measure levels and track trends in maternal mortality, the key causes contributing to maternal death, and timing of maternal death with respect to delivery.

METHODS

We used robust statistical methods including the Cause of Death Ensemble model (CODEm) to analyse a database of data for 7065 site-years and estimate the number of maternal deaths from all causes in 188 countries between 1990 and 2013. We estimated the number of pregnancy-related deaths caused by HIV on the basis of a systematic review of the relative risk of dying during pregnancy for HIV-positive women compared with HIV-negative women. We also estimated the fraction of these deaths aggravated by pregnancy on the basis of a systematic review. To estimate the numbers of maternal deaths due to nine different causes, we identified 61 sources from a systematic review and 943 site-years of vital registration data. We also did a systematic review of reports about the timing of maternal death, identifying 142 sources to use in our analysis. We developed estimates for each country for 1990-2013 using Bayesian meta-regression. We estimated 95% uncertainty intervals (UIs) for all values.

RESULTS

292,982 (95% UI 261,017-327,792) maternal deaths occurred in 2013, compared with 376,034 (343,483-407,574) in 1990. The global annual rate of change in the MMR was -0·3% (-1·1 to 0·6) from 1990 to 2003, and -2·7% (-3·9 to -1·5) from 2003 to 2013, with evidence of continued acceleration. MMRs reduced consistently in south, east, and southeast Asia between 1990 and 2013, but maternal deaths increased in much of sub-Saharan Africa during the 1990s. 2070 (1290-2866) maternal deaths were related to HIV in 2013, 0·4% (0·2-0·6) of the global total. MMR was highest in the oldest age groups in both 1990 and 2013. In 2013, most deaths occurred intrapartum or postpartum. Causes varied by region and between 1990 and 2013. We recorded substantial variation in the MMR by country in 2013, from 956·8 (685·1-1262·8) in South Sudan to 2·4 (1·6-3·6) in Iceland.

CONCLUSIONS

Global rates of change suggest that only 16 countries will achieve the MDG 5 target by 2015. Accelerated reductions since the Millennium Declaration in 2000 coincide with increased development assistance for maternal, newborn, and child health. Setting of targets and associated interventions for after 2015 will need careful consideration of regions that are making slow progress, such as west and central Africa.

BACKGROUND

Bill & Melinda Gates Foundation.

BACKGROUND

The Millennium Declaration in 2000 brought special global attention to HIV, tuberculosis, and malaria through the formulation of Millennium Development Goal (MDG) 6. The Global Burden of Disease 2013 study provides a consistent and comprehensive approach to disease estimation for between 1990 and 2013, and an opportunity to assess whether accelerated progress has occured since the Millennium Declaration.

METHODS

To estimate incidence and mortality for HIV, we used the UNAIDS Spectrum model appropriately modified based on a systematic review of available studies of mortality with and without antiretroviral therapy (ART). For concentrated epidemics, we calibrated Spectrum models to fit vital registration data corrected for misclassification of HIV deaths. In generalised epidemics, we minimised a loss function to select epidemic curves most consistent with prevalence data and demographic data for all-cause mortality. We analysed counterfactual scenarios for HIV to assess years of life saved through prevention of mother-to-child transmission (PMTCT) and ART. For tuberculosis, we analysed vital registration and verbal autopsy data to estimate mortality using cause of death ensemble modelling. We analysed data for corrected case-notifications, expert opinions on the case-detection rate, prevalence surveys, and estimated cause-specific mortality using Bayesian meta-regression to generate consistent trends in all parameters. We analysed malaria mortality and incidence using an updated cause of death database, a systematic analysis of verbal autopsy validation studies for malaria, and recent studies (2010-13) of incidence, drug resistance, and coverage of insecticide-treated bednets.

RESULTS

Globally in 2013, there were 1·8 million new HIV infections (95% uncertainty interval 1·7 million to 2·1 million), 29·2 million prevalent HIV cases (28·1 to 31·7), and 1·3 million HIV deaths (1·3 to 1·5). At the peak of the epidemic in 2005, HIV caused 1·7 million deaths (1·6 million to 1·9 million). Concentrated epidemics in Latin America and eastern Europe are substantially smaller than previously estimated. Through interventions including PMTCT and ART, 19·1 million life-years (16·6 million to 21·5 million) have been saved, 70·3% (65·4 to 76·1) in developing countries. From 2000 to 2011, the ratio of development assistance for health for HIV to years of life saved through intervention was US$4498 in developing countries. Including in HIV-positive individuals, all-form tuberculosis incidence was 7·5 million (7·4 million to 7·7 million), prevalence was 11·9 million (11·6 million to 12·2 million), and number of deaths was 1·4 million (1·3 million to 1·5 million) in 2013. In the same year and in only individuals who were HIV-negative, all-form tuberculosis incidence was 7·1 million (6·9 million to 7·3 million), prevalence was 11·2 million (10·8 million to 11·6 million), and number of deaths was 1·3 million (1·2 million to 1·4 million). Annualised rates of change (ARC) for incidence, prevalence, and death became negative after 2000. Tuberculosis in HIV-negative individuals disproportionately occurs in men and boys (versus women and girls); 64·0% of cases (63·6 to 64·3) and 64·7% of deaths (60·8 to 70·3). Globally, malaria cases and deaths grew rapidly from 1990 reaching a peak of 232 million cases (143 million to 387 million) in 2003 and 1·2 million deaths (1·1 million to 1·4 million) in 2004. Since 2004, child deaths from malaria in sub-Saharan Africa have decreased by 31·5% (15·7 to 44·1). Outside of Africa, malaria mortality has been steadily decreasing since 1990.

CONCLUSIONS

Our estimates of the number of people living with HIV are 18·7% smaller than UNAIDS's estimates in 2012. The number of people living with malaria is larger than estimated by WHO. The number of people living with HIV, tuberculosis, or malaria have all decreased since 2000. At the global level, upward trends for malaria and HIV deaths have been reversed and declines in tuberculosis deaths have accelerated. 101 countries (74 of which are developing) still have increasing HIV incidence. Substantial progress since the Millennium Declaration is an encouraging sign of the effect of global action.

BACKGROUND

Bill & Melinda Gates Foundation.

BACKGROUND

Spontaneous control of human immunodeficiency virus (HIV) infection has been documented in a minority of HIV-infected individuals. The mechanisms behind this outcome remain largely unknown, and a better understanding of them will likely influence future vaccine strategies.

METHODS

HIV-specific T cell and antibody responses as well as host genetics were examined in untreated HIV-infected patients who maintain comparatively low plasma HIV RNA levels (hereafter, controllers), including those with levels of < 50 RNA copies/mL (elite controllers, n = 64), those with levels of 50-2000 copies/mL (viremic controllers, n = 60); we also examined HIV-specific T cell and antibody responses as well as host genetics for patients with levels of >10,000 copies/mL (chronic progressors, n = 30).

RESULTS

CD8+ T cells from both controller groups preferentially target Gag over other proteins in the context of diverse HLA class I alleles, whereas responses are more broadly distributed in persons with progressive infection. Elite controllers represent a distinct group of individuals who have significantly more CD4 and CD8 T cells that secrete interferon-gamma and interleukin-2 and lower levels of HIV-neutralizing antibodies. Individual responses were quite heterogeneous, and none of the parameters evaluated was uniquely associated with the ability to control viremia.

CONCLUSIONS

Elite controllers are a distinct group, even when compared to persons with low level viremia, but they exhibit marked genetic and immunologic heterogeneity. Even low-level viremia among HIV controllers was associated with measurable T cell dysfunction, which has implications for current prophylactic vaccine strategies.

The tuberous sclerosis complex (TSC)-mammalian target of rapamycin (mTOR) pathway is a key regulator of cellular metabolism. We used conditional deletion of Tsc1 to address how quiescence is associated with the function of hematopoietic stem cells (HSCs). We demonstrate that Tsc1 deletion in the HSCs drives them from quiescence into rapid cycling, with increased mitochondrial biogenesis and elevated levels of reactive oxygen species (ROS). Importantly, this deletion dramatically reduced both hematopoiesis and self-renewal of HSCs, as revealed by serial and competitive bone marrow transplantation. In vivo treatment with an ROS antagonist restored HSC numbers and functions. These data demonstrated that the TSC-mTOR pathway maintains the quiescence and function of HSCs by repressing ROS production. The detrimental effect of up-regulated ROS in metabolically active HSCs may explain the well-documented association between quiescence and the "stemness" of HSCs.

Protein localization data are a valuable information resource helpful in elucidating eukaryotic protein function. Here, we report the first proteome-scale analysis of protein localization within any eukaryote. Using directed topoisomerase I-mediated cloning strategies and genome-wide transposon mutagenesis, we have epitope-tagged 60% of the Saccharomyces cerevisiae proteome. By high-throughput immunolocalization of tagged gene products, we have determined the subcellular localization of 2744 yeast proteins. Extrapolating these data through a computational algorithm employing Bayesian formalism, we define the yeast localizome (the subcellular distribution of all 6100 yeast proteins). We estimate the yeast proteome to encompass approximately 5100 soluble proteins and >1000 transmembrane proteins. Our results indicate that 47% of yeast proteins are cytoplasmic, 13% mitochondrial, 13% exocytic (including proteins of the endoplasmic reticulum and secretory vesicles), and 27% nuclear/nucleolar. A subset of nuclear proteins was further analyzed by immunolocalization using surface-spread preparations of meiotic chromosomes. Of these proteins, 38% were found associated with chromosomal DNA. As determined from phenotypic analyses of nuclear proteins, 34% are essential for spore viability--a percentage nearly twice as great as that observed for the proteome as a whole. In total, this study presents experimentally derived localization data for 955 proteins of previously unknown function: nearly half of all functionally uncharacterized proteins in yeast. To facilitate access to these data, we provide a searchable database featuring 2900 fluorescent micrographs at http://ygac.med.yale.edu.

Patten recognition receptors, which recognize pathogens or components of injured cells (danger), trigger activation of the innate immune system. Whether and how the host distinguishes between danger- versus pathogen-associated molecular patterns remains unresolved. We report that CD24-deficient mice exhibit increased susceptibility to danger- but not pathogen-associated molecular patterns. CD24 associates with high mobility group box 1, heat shock protein 70, and heat shock protein 90; negatively regulates their stimulatory activity; and inhibits nuclear factor kappaB (NF-kappaB) activation. This occurs at least in part through CD24 association with Siglec-10 in humans or Siglec-G in mice. Our results reveal that the CD24-Siglec G pathway protects the host against a lethal response to pathological cell death and discriminates danger- versus pathogen-associated molecular patterns.

Age-related declines in hematopoietic stem cell (HSC) function may contribute to anemia, poor response to vaccination, and tumorigenesis. Here, we show that mammalian target of rapamycin (mTOR) activity is increased in HSCs from old mice compared to those from young mice. mTOR activation through conditional deletion of Tsc1 in the HSCs of young mice mimicked the phenotype of HSCs from aged mice in various ways. These included increased abundance of the messenger RNA encoding the CDK inhibitors p16(Ink4a), p19(Arf), and p21(Cip1); a relative decrease in lymphopoiesis; and impaired capacity to reconstitute the hematopoietic system. In old mice, rapamycin increased life span, restored the self-renewal and hematopoiesis of HSCs, and enabled effective vaccination against a lethal challenge with influenza virus. Together, our data implicate mTOR signaling in HSC aging and show the potential of mTOR inhibitors for restoring hematopoiesis in the elderly.

BACKGROUND

Exposure to ambient air pollution increases morbidity and mortality, and is a leading contributor to global disease burden. We explored spatial and temporal trends in mortality and burden of disease attributable to ambient air pollution from 1990 to 2015 at global, regional, and country levels.

METHODS

We estimated global population-weighted mean concentrations of particle mass with aerodynamic diameter less than 2·5 μm (PM2·5) and ozone at an approximate 11 km × 11 km resolution with satellite-based estimates, chemical transport models, and ground-level measurements. Using integrated exposure-response functions for each cause of death, we estimated the relative risk of mortality from ischaemic heart disease, cerebrovascular disease, chronic obstructive pulmonary disease, lung cancer, and lower respiratory infections from epidemiological studies using non-linear exposure-response functions spanning the global range of exposure.

RESULTS

Ambient PM2·5 was the fifth-ranking mortality risk factor in 2015. Exposure to PM2·5 caused 4·2 million (95% uncertainty interval [UI] 3·7 million to 4·8 million) deaths and 103·1 million (90·8 million 115·1 million) disability-adjusted life-years (DALYs) in 2015, representing 7·6% of total global deaths and 4·2% of global DALYs, 59% of these in east and south Asia. Deaths attributable to ambient PM2·5 increased from 3·5 million (95% UI 3·0 million to 4·0 million) in 1990 to 4·2 million (3·7 million to 4·8 million) in 2015. Exposure to ozone caused an additional 254 000 (95% UI 97 000-422 000) deaths and a loss of 4·1 million (1·6 million to 6·8 million) DALYs from chronic obstructive pulmonary disease in 2015.

CONCLUSIONS

Ambient air pollution contributed substantially to the global burden of disease in 2015, which increased over the past 25 years, due to population ageing, changes in non-communicable disease rates, and increasing air pollution in low-income and middle-income countries. Modest reductions in burden will occur in the most polluted countries unless PM2·5 values are decreased substantially, but there is potential for substantial health benefits from exposure reduction.

BACKGROUND

Bill & Melinda Gates Foundation and Health Effects Institute.

Amplification of the gene encoding the ErbB2 (Her2/neu) receptor tyrosine kinase is critical for the progression of several forms of breast cancer. In a large-scale clinical trial, treatment with Herceptin (trastuzumab), a humanized blocking antibody against ErbB2, led to marked improvement in survival. However, cardiomyopathy was uncovered as a mitigating side effect, thereby suggesting an important role for ErbB2 signaling as a modifier of human heart failure. To investigate the physiological role of ErbB2 signaling in the adult heart, we generated mice with a ventricular-restricted deletion of Erbb2. These ErbB2-deficient conditional mutant mice were viable and displayed no overt phenotype. However, physiological analysis revealed the onset of multiple independent parameters of dilated cardiomyopathy, including chamber dilation, wall thinning and decreased contractility. Additionally, cardiomyocytes isolated from these conditional mutants were more susceptible to anthracycline toxicity. ErbB2 signaling in cardiomyocytes is therefore essential for the prevention of dilated cardiomyopathy.

Birds are the most species-rich class of tetrapod vertebrates and have wide relevance across many research fields. We explored bird macroevolution using full genomes from 48 avian species representing all major extant clades. The avian genome is principally characterized by its constrained size, which predominantly arose because of lineage-specific erosion of repetitive elements, large segmental deletions, and gene loss. Avian genomes furthermore show a remarkably high degree of evolutionary stasis at the levels of nucleotide sequence, gene synteny, and chromosomal structure. Despite this pattern of conservation, we detected many non-neutral evolutionary changes in protein-coding genes and noncoding regions. These analyses reveal that pan-avian genomic diversity covaries with adaptations to different lifestyles and convergent evolution of traits.

In the developing brain, transcription factors (TFs) direct the formation of a diverse array of neurons and glia. We identifed 1445 putative TFs in the mouse genome. We used in situ hybridization to map the expression of over 1000 of these TFs and TF-coregulator genes in the brains of developing mice. We found that 349 of these genes showed restricted expression patterns that were adequate to describe the anatomical organization of the brain. We provide a comprehensive inventory of murine TFs and their expression patterns in a searchable brain atlas database.

Brain-derived neurotrophic factor (BDNF), a cognate ligand for the tyrosine kinase receptor B (TrkB) receptor, mediates neuronal survival, differentiation, synaptic plasticity, and neurogenesis. However, BDNF has a poor pharmacokinetic profile that limits its therapeutic potential. Here we report the identification of 7,8-dihydroxyflavone as a bioactive high-affinity TrkB agonist that provokes receptor dimerization and autophosphorylation and activation of downstream signaling. 7,8-Dihydroxyflavone protected wild-type, but not TrkB-deficient, neurons from apoptosis. Administration of 7,8-dihydroxyflavone to mice activated TrkB in the brain, inhibited kainic acid-induced toxicity, decreased infarct volumes in stroke in a TrkB-dependent manner, and was neuroprotective in an animal model of Parkinson disease. Thus, 7,8-dihydroxyflavone imitates BDNF and acts as a robust TrkB agonist, providing a powerful therapeutic tool for the treatment of various neurological diseases.

HIV type 1 (HIV-1) can rapidly escape from neutralizing antibody responses. The genetic basis of this escape in vivo is poorly understood. We compared the pattern of evolution of the HIV-1 env gene between individuals with recent HIV infection whose virus exhibited either a low or a high rate of escape from neutralizing antibody responses. We demonstrate that the rate of viral escape at a phenotypic level is highly variable among individuals, and is strongly correlated with the rate of amino acid substitutions. We show that dramatic escape from neutralizing antibodies can occur in the relative absence of changes in glycosylation or insertions and deletions ("indels") in the envelope; conversely, changes in glycosylation and indels occur even in the absence of neutralizing antibody responses. Comparison of our data with the predictions of a mathematical model support a mechanism in which escape from neutralizing antibodies occurs via many amino acid substitutions, with low cross-neutralization between closely related viral strains. Our results suggest that autologous neutralizing antibody responses may play a pivotal role in the diversification of HIV-1 envelope during the early stages of infection.

Caveolins are important components of caveolae, which have been implicated in vesicular trafficking and signal transduction. To investigate the in vivo significance of Caveolins in mammals, we generated mice deficient in the caveolin-1 (cav-1) gene and have shown that, in the absence of Cav-1, no caveolae structures were observed in several nonmuscle cell types. Although cav-1(-/-) mice are viable, histological examination and echocardiography identified a spectrum of characteristics of dilated cardiomyopathy in the left ventricular chamber of the cav-1-deficient hearts, including an enlarged ventricular chamber diameter, thin posterior wall, and decreased contractility. These animals also have marked right ventricular hypertrophy, suggesting a chronic increase in pulmonary artery pressure. Direct measurement of pulmonary artery pressure and histological analysis revealed that the cav-1(-/-) mice exhibit pulmonary hypertension, which may contribute to the right ventricle hypertrophy. In addition, the loss of Cav-1 leads to a dramatic increase in systemic NO levels. Our studies provided in vivo evidence that cav-1 is essential for the control of systemic NO levels and normal cardiopulmonary function.

The cell-to-cell transmission of viral resistance is a potential mechanism for amplifying the interferon-induced antiviral response. In this study, we report that interferon-α (IFN-α) induced the transfer of resistance to hepatitis B virus (HBV) from nonpermissive liver nonparenchymal cells (LNPCs) to permissive hepatocytes via exosomes. Exosomes from IFN-α-treated LNPCs were rich in molecules with antiviral activity. Moreover, exosomes from LNPCs were internalized by hepatocytes, which mediated the intercellular transfer of antiviral molecules. Finally, we found that exosomes also contributed to the antiviral response of IFN-α to mouse hepatitis virus A59 and adenovirus in mice. Thus, we propose an antiviral mechanism of IFN-α activity that involves the induction and intercellular transfer of antiviral molecules via exosomes.

BACKGROUND

Many studies have explored the association between soluble interleukin-2 receptor (sIL-2R), cytokines and major depressive disorder (MDD). However, the results of these studies were not consistent. The aim of our study is to compare the levels of sIL-2R and cytokines in the blood between MDD patients and controls by a meta-analysis and to identify moderators accounting for potential heterogeneity in the levels of sIL-2R and cytokines in MDD patients versus controls by meta-regression analyses.

METHODS

A comprehensive literature search was performed to identify studies comparing the levels of sIL-2R and cytokines between MDD patients and controls. We pooled the effect sizes for standardized mean differences (SMD) of the levels of sIL-2R and cytokines. We also performed meta-regression and sensitivity analyses to investigate the roles of age, gender, sample type, ethnic origin and selected studies' quality in explaining potential heterogeneity and differences in results respectively.

RESULTS

Twenty-nine studies were selected for this analysis. The levels of sIL-2R, TNF-α and IL-6 in MDD patients were significantly higher than those of healthy controls (SMD=0.555, p<0.001, SMD=0.567, p=0.010; SMD=0.680, p<0.001). Mean age of all subjects was a significant moderator to explain the high heterogeneity of IL-6. Sensitivity analysis found that European but not non-European subjects have higher levels difference of sIL-2R, TNF-α and IL-1β between MDD patients and controls.

CONCLUSIONS

The severity of MDD was not considered.

CONCLUSIONS

The blood levels of sIL-2R, TNF-α and IL-6 were significantly higher in MDD patients than controls. Age, samples source and ethnic origins may play a potential role in heterogeneity.

Anti-HER2/neu antibody therapy is reported to mediate tumor regression by interrupting oncogenic signals and/or inducing FcR-mediated cytotoxicity. Here, we demonstrate that the mechanisms of tumor regression by this therapy also require the adaptive immune response. Activation of innate immunity and T cells, initiated by antibody treatment, was necessary. Intriguingly, the addition of chemotherapeutic drugs, although capable of enhancing the reduction of tumor burden, could abrogate antibody-initiated immunity leading to decreased resistance to rechallenge or earlier relapse. Increased influx of both innate and adaptive immune cells into the tumor microenvironment by a selected immunotherapy further enhanced subsequent antibody-induced immunity, leading to increased tumor eradication and resistance to rechallenge. This study proposes a model and strategy for anti-HER2/neu antibody-mediated tumor clearance.

Microglial activation is a key feature in Alzheimer's disease and is considered to contribute to progressive neuronal injury by release of neurotoxic products. The innate immune receptor Toll-like-receptor 4 (TLR4), localized on the surface of microglia, is a first-line host defense receptor against invading microorganisms. Here, we show that a spontaneous loss-of-function mutation in the Tlr4 gene strongly inhibits microglial and monocytic activation by aggregated Alzheimer amyloid peptide resulting in a significantly lower release of the inflammatory products IL-6, TNFalpha and nitric oxide. Treatment of primary murine neuronal cells with supernatant of amyloid peptide-stimulated microglia demonstrates that Tlr4 contributes to amyloid peptide-induced microglial neurotoxicity. In addition, stimulation experiments in transfected HEK293 cells allowed to define a tri-molecular receptor complex consisting of TLR4, MD-2 and CD14 necessary for full cellular activation by aggregated amyloid peptide. A clinical relevance of these findings is supported by a marked upregulation of Tlr4 mRNA in APP transgenic mice and by an increased expression of TLR4 in Alzheimer's disease brain tissue associated with amyloid plaque deposition. Together, these observations provide the first evidence for a role of the key innate immune receptor, TLR4, in neuroinflammation in Alzheimer's disease.

Molecular targeting of cancer stem cells (CSCs) has therapeutic potential for efficient treatment of cancer, although relatively few specific targets have been identified so far. Hypoxia-inducible factor (HIF) was recently shown to regulate the tumorigenic capacity of glioma stem cells under hypoxic conditions. Surprisingly, we found that, under normoxia, HIF1α signaling was selectively activated in the stem cells of mouse lymphoma and human acute myeloid leukemia (AML). HIF1a shRNA and HIF inhibitors abrogated the colony-forming unit (cfu) activity of mouse lymphoma and human AML CSCs. Importantly, the HIF-inhibitor echinomycin efficiently eradicated mouse lymphoma and serially transplantable human AML in xenogeneic models by preferential elimination of CSCs. Hif1α maintains mouse lymphoma CSCs by repressing a negative feedback loop in the Notch pathway. Taken together, our results demonstrate an essential function of Hif1α-Notch interaction in maintaining CSCs and provide an effective approach to target CSCs for therapy of hematological malignancies.

We have taken the first steps towards a complete reconstruction of the Mycobacterium tuberculosis regulatory network based on ChIP-Seq and combined this reconstruction with system-wide profiling of messenger RNAs, proteins, metabolites and lipids during hypoxia and re-aeration. Adaptations to hypoxia are thought to have a prominent role in M. tuberculosis pathogenesis. Using ChIP-Seq combined with expression data from the induction of the same factors, we have reconstructed a draft regulatory network based on 50 transcription factors. This network model revealed a direct interconnection between the hypoxic response, lipid catabolism, lipid anabolism and the production of cell wall lipids. As a validation of this model, in response to oxygen availability we observe substantial alterations in lipid content and changes in gene expression and metabolites in corresponding metabolic pathways. The regulatory network reveals transcription factors underlying these changes, allows us to computationally predict expression changes, and indicates that Rv0081 is a regulatory hub.