Rapid assessment of adenovirus serum neutralizing antibody titer based on quantitative, morphometric evaluation of capsid binding and intracellular trafficking: population analysis of adenovirus capsid association with cells is predictive of adenovirus infectivity

Neutralizing antiviral antibodies are typically detected on the basis of inhibition of viral function, such as propagation of a viral infection or inhibition of viral gene expression. Evidence is presented that anti-adenovirus neutralizing antibodies can be evaluated by analysis of cell-associated capsids or by analysis of intracellular trafficking of the capsids within 1 h after infection. Quantitative analyses of these morphologic parameters represent rapid, broadly applicable, functional assays for the detection of anti-adenovirus neutralizing antibodies.     

Role of thiocyanate, bromide and hypobromous acid in hydrogen peroxide-induced apoptosis

We have previously reported that H₂O₂-induced apoptosis in HL-60 human leukemia cells takes place in the presence of chloride, requires myeloperoxidase (MPO), and occurs through oxidative reactions involving hypochlorous acid and chloramines. We now report that when chloride is replaced by the pseudohalide thiocyanate, there is little or no H₂O₂-induced apoptosis. Furthermore, thiocyanate inhibits H₂O₂-induced apoptosis when chloride is present at physiological concentrations, and this occurs at thiocyanate concentrations that are present in human serum and saliva. In contrast, bromide can substitute for chloride in H₂O₂-induced apoptosis, but results in a lower percent of the cells induced into apoptosis. Hypobromous acid is likely a short-lived intermediate in this H₂O₂/MPO/bromide apoptosis, and reagent hypobromous acid and bromamines induce apoptosis in HL-60 cells. We conclude that the physiologic concentrations of thiocyanate found in human plasma could modulate the cytototoxicity of H₂O₂ and its resulting highly toxic MPO-generated hypochlorous acid by competing with chloride for MPO. Furthermore, the oxidative products of the reaction of thiocyanate with MPO are relatively innocuous for human leukemic cells in culture. In contrast, bromide can support H₂O₂/MPO/halide apoptosis, but is less potent than chloride and it has no effect in the presence of physiological levels of chloride.     

Fixing a snag in carbon emissions estimates from wildfires

Wildfire is an essential earth‐system process, impacting ecosystem processes and the carbon cycle. Forest fires are becoming more frequent and severe, yet gaps exist in the modeling of fire on vegetation and carbon dynamics. Strategies for reducing carbon dioxide (CO₂) emissions from wildfires include increasing tree harvest, largely based on the public assumption that fires burn live forests to the ground, despite observations indicating that less than 5% of mature tree biomass is actually consumed. This misconception is also reflected though excessive combustion of live trees in models. Here, we show that regional emissions estimates using widely implemented combustion coefficients are 59%–83% higher than emissions based on field observations. Using unique field datasets from before and after wildfires and an improved ecosystem model, we provide strong evidence that these large overestimates can be reduced by using realistic biomass combustion factors and by accurately quantifying biomass in standing dead trees that decompose over decades to centuries after fire (“snags”). Most model development focuses on area burned; our results reveal that accurately representing combustion is also essential for quantifying fire impacts on ecosystems. Using our improvements, we find that western US forest fires have emitted 851 ± 228 Tg CO₂ (~half of alternative estimates) over the last 17 years, which is minor compared to 16,200 Tg CO₂ from fossil fuels across the region.     

Impairment of TrkB-PSD-95 Signaling in Angelman Syndrome

Angelman syndrome (AS) is a neurodevelopment disorder characterized by severe cognitive impairment and a high rate of autism. AS is caused by disrupted neuronal expression of the maternally inherited Ube3A ubiquitin protein ligase, required for the proteasomal degradation of proteins implicated in synaptic plasticity, such as the activity-regulated cytoskeletal-associated protein (Arc/Arg3.1). Mice deficient in maternal Ube3A express elevated levels of Arc in response to synaptic activity, which coincides with severely impaired long-term potentiation (LTP) in the hippocampus and deficits in learning behaviors. In this study, we sought to test whether elevated levels of Arc interfere with brain-derived neurotrophic factor (BDNF) TrkB receptor signaling, which is known to be essential for both the induction and maintenance of LTP. We report that TrkB signaling in the AS mouse is defective, and show that reduction of Arc expression to control levels rescues the signaling deficits. Moreover, the association of the postsynaptic density protein PSD-95 with TrkB is critical for intact BDNF signaling, and elevated levels of Arc were found to impede PSD-95/TrkB association. In Ube3A deficient mice, the BDNF-induced recruitment of PSD-95, as well as PLCγ and Grb2-associated binder 1 (Gab1) with TrkB receptors was attenuated, resulting in reduced activation of PLCγ-α-calcium/calmodulin-dependent protein kinase II (CaMKII) and PI3K-Akt, but leaving the extracellular signal-regulated kinase (Erk) pathway intact. A bridged cyclic peptide (CN2097), shown by nuclear magnetic resonance (NMR) studies to uniquely bind the PDZ1 domain of PSD-95 with high affinity, decreased the interaction of Arc with PSD-95 to restore BDNF-induced TrkB/PSD-95 complex formation, signaling, and facilitate the induction of LTP in AS mice. We propose that the failure of TrkB receptor signaling at synapses in AS is directly linked to elevated levels of Arc associated with PSD-95 and PSD-95 PDZ-ligands may represent a promising approach to reverse cognitive dysfunction.     

Brain imaging investigation of the neural correlates of observing virtual social interactions

The ability to gauge social interactions is crucial in the assessment of others' intentions. Factors such as facial expressions and body language affect our decisions in personal and professional life alike (1). These "friend or foe" judgements are often based on first impressions, which in turn may affect our decisions to "approach or avoid". Previous studies investigating the neural correlates of social cognition tended to use static facial stimuli (2). Here, we illustrate an experimental design in which whole-body animated characters were used in conjunction with functional magnetic resonance imaging (fMRI) recordings. Fifteen participants were presented with short movie-clips of guest-host interactions in a business setting, while fMRI data were recorded; at the end of each movie, participants also provided ratings of the host behaviour. This design mimics more closely real-life situations, and hence may contribute to better understanding of the neural mechanisms of social interactions in healthy behaviour, and to gaining insight into possible causes of deficits in social behaviour in such clinical conditions as social anxiety and autism (3).     

Yu Ping Feng San,an Ancient Chinese Herbal Decoction Containing Astragali Radix,Atractylodis Macrocephalae Rhizoma and Saposhnikoviae Radix,Regulates the Release of Cytokines in Murine Macrophages

Yu Ping Feng San (YPFS), a Chinese herbal decoction, is composed of Astragali Radix (AR; Huangqi), Atractylodis Macrocephalae Rhizoma (AMR; Baizhu) and Saposhnikoviae Radix (SR; Fangfeng) in a weight ratio of 1∶2∶1. Clinically, YPFS has been widely used to regulate immune functions; however, the action mechanism of it is not known. Here, we addressed this issue by providing detail analyses of chemical and biological properties of YPFS. By using rapid resolution liquid chromatography coupled with mass spectrometry, fifteen chemicals deriving from different herbs of YPFS were determined, and which served as a control for the standardization of the herbal extract of YPFS. In general, the amounts of chosen chemical markers were higher in a preparation of YPFS as compared to that of single herb or two-herb compositions. In order to reveal the immune functions of YPFS, the standardized extract was applied onto cultured murine macrophages. The treatment of YPFS stimulated the mRNA and protein expressions of pro-inflammatory cytokines via activation of NF-κB by enhancing IκBα degradation. In contrast, the application of YPFS suppressed the expressions of pro-inflammatory cytokines significantly in the lipopolysaccharide (LPS)-induced chronic inflammation model. In addition, YPFS could up regulate the phagocytic activity in cultured macrophages. These results therefore supported the bi-directional immune-modulatory roles of YPFS in regulating the releases of cytokines from macrophages.     

The Efficacy of the BCG Vaccine against Newly Emerging Clinical Strains of Mycobacterium tuberculosis

To date, most new vaccines against Mycobacterium tuberculosis, including new recombinant versions of the current BCG vaccine, have usually been screened against the laboratory strains H37Rv or Erdman. In this study we took advantage of our recent work in characterizing an increasingly large panel of newly emerging clinical isolates [from the United States or from the Western Cape region of South Africa], to determine to what extent vaccines would protect against these [mostly high virulence] strains. We show here that both BCG Pasteur and recombinant BCG Aeras-422 [used here as a good example of the new generation BCG vaccines] protected well in both mouse and guinea pig low dose aerosol infection models against the majority of clinical isolates tested. However, Aeras-422 was not effective in a long term survival assay compared to BCG Pasteur. Protection was very strongly expressed against all of the Western Cape strains tested, reinforcing our viewpoint that any attempt at boosting BCG would be very difficult to achieve statistically. This observation is discussed in the context of the growing argument made by others that the failure of a recent vaccine trial disqualifies the further use of animal models to predict vaccine efficacy. This viewpoint is in our opinion completely erroneous, and that it is the fitness of prevalent strains in the trial site area that is the centrally important factor, an issue that is not being addressed by the field.     

Deep Whole-Genome Sequencing of 100 Southeast Asian Malays

Whole-genome sequencing across multiple samples in a population provides an unprecedented opportunity for comprehensively characterizing the polymorphic variants in the population. Although the 1000 Genomes Project (1KGP) has offered brief insights into the value of population-level sequencing, the low coverage has compromised the ability to confidently detect rare and low-frequency variants. In addition, the composition of populations in the 1KGP is not complete, despite the fact that the study design has been extended to more than 2,500 samples from more than 20 population groups. The Malays are one of the Austronesian groups predominantly present in Southeast Asia and Oceania, and the Singapore Sequencing Malay Project (SSMP) aims to perform deep whole-genome sequencing of 100 healthy Malays. By sequencing at a minimum of 30× coverage, we have illustrated the higher sensitivity at detecting low-frequency and rare variants and the ability to investigate the presence of hotspots of functional mutations. Compared to the low-pass sequencing in the 1KGP, the deeper coverage allows more functional variants to be identified for each person. A comparison of the fidelity of genotype imputation of Malays indicated that a population-specific reference panel, such as the SSMP, outperforms a cosmopolitan panel with larger number of individuals for common SNPs. For lower-frequency (<5%) markers, a larger number of individuals might have to be whole-genome sequenced so that the accuracy currently afforded by the 1KGP can be achieved. The SSMP data are expected to be the benchmark for evaluating the value of deep population-level sequencing versus low-pass sequencing, especially in populations that are poorly represented in population-genetics studies.