An increased number of circulating γ/δ TCR + T cells in patients with chronic viral hepatitis

Abstract There is evidence that γ/δ TCR + T cells are specialized in recognizing different antigens, but their immunologic role as a second TCR is still unclear. The aim of this study was to investigate the percentage and absolute numbers of circulating γ/δ TCR + T cells in patients with chronic viral hepatitis (CVH) and to compare with HBsAg⁺, HCV healthy carriers and healthy subjects. Forty nine patients with CVH-24 with chronic active (CAH) and 25 with chronic persistent hepatitis (CPH)-, 21 HBsAg⁺, 20 HCV asymptomatic carriers and 20 healthy subjects were enrolled in the study. Lymphocyte subsets were determined after incubation with monoclonal antibodies to T total (CD5) and T γ/δ cells (γ/δ-1) using immunofluorescence microscopy. An increased number of circulating γ/δ TCR + T cells was found in patients with CVH in comparison with asymptomatic carriers and normal controls: this increase was more profound in patients with CAH, compared to CPH patients. These results indicate a correlation between circulating γ/δ TCR + T cells in CVH patients and activity and chronicity of the disease.     

Biosynthesis profile and endogenous titers of polyamines differ in totipotent and recalcitrant plant protoplasts

The expression of totipotency in plant protoplasts is a complex developmental phenomenon and is affected by genetic and physiological factors. Polyamines (PAs) are known to be involved in a variety of growth and developmental processes in higher plants, as well as in adaptation to stresses. In this study, we present the homeostatic characteristics of the endogenous PA putrescine (Put), spermidine (Spd), and spermine (Spm) in totipotent (T) and non-totipotent (NT) tobacco protoplasts and in recalcitrant (R) grapevine protoplasts. T-tobacco protoplasts, with high division rates, have the highest level of endogenous PAs. In these protoplasts, the soluble-hydrolyzed fraction predominates and increases, and the insoluble-hydrolyzed fraction also increases, whereas soluble (S) PAs decrease rapidly during culture. The isolation process contributes to the increased Put levels, which are higher in freshly isolated NT-tobacco protoplasts than in T-protoplasts. During culture, total Put predominates over Spd and Spm, and the highest accumulation is found in T-protoplasts. Ornithine decarboxylase and arginase activities both increase in T-protoplasts, whereas arginine decarboxylase activity causes Put accumulation in NT-tobacco protoplasts. R-grapevine protoplasts show a different PA profile, mostly due to the lower PA content, the higher S-fraction, and the higher ratio of Spm to total PAs. The data suggest that the levels and metabolism of the intracellular PAs could be related to the expression of totipotency of plant protoplasts.     

A comparative approach towards thylakoid membrane proteome analysis of unicellular green alga Scenedesmus obliquus

The chlorophyll (Chl)-containing membrane protein complexes from the green alga Scenedesmus obliquus have been isolated from the thylakoid membranes by solubilization with dodecyl-beta-maltoside and fractionation using a sucrose density gradient. The Chl-containing protein fractions were characterized by absorption spectroscopy, tricine SDS PAGE, BN-PAGE, and dynamic light scattering (DLS). BN-PAGE showed the presence of seven protein complexes with molecular weights in the range of 68, 118, 157, 320, 494, 828 and 955 kDa, respectively. Furthermore, light scattering reveals the simultaneous presence of particles of different sizes in the 3-4 nm and 6.0-7.5 nm range, respectively. The smaller size is related to the hydrodynamic radius of the trimer Light Harvesting Complex (LHCII), whereas the larger size is associated with the presence of photosystem I and photosystem II reaction centers. Additionally, functional information regarding protein-protein interactions was deconvoluted using coupling 2-D BN-PAGE, MALDI-TOF MS and a detailed mapping of S. obliquus photosynthetic proteome of the solubilized thylakoid membranes is therefore presented.     

Complete genome sequence of "Enterobacter lignolyticus" SCF1

In an effort to discover anaerobic bacteria capable of lignin degradation, we isolated "Enterobacter lignolyticus" SCF1 on minimal media with alkali lignin as the sole source of carbon. This organism was isolated anaerobically from tropical forest soils collected from the Short Cloud Forest site in the El Yunque National Forest in Puerto Rico, USA, part of the Luquillo Long-Term Ecological Research Station. At this site, the soils experience strong fluctuations in redox potential and are net methane producers. Because of its ability to grow on lignin anaerobically, we sequenced the genome. The genome of "E. lignolyticus" SCF1 is 4.81 Mbp with no detected plasmids, and includes a relatively small arsenal of lignocellulolytic carbohydrate active enzymes. Lignin degradation was observed in culture, and the genome revealed two putative laccases, a putative peroxidase, and a complete 4-hydroxyphenylacetate degradation pathway encoded in a single gene cluster.     

Assessing the Risk of Soil Pollution around an Industrialized Mining Region Using a Geostatistical Approach

Knowledge of mobility of some heavy metals in coal mining areas is fundamental in order to understand their toxicity and geochemical behavior. This paper aims to map pollution and assess the risk to agricultural soils in a wider lignite opencast mining and industrial area. Geochemical data related to environmental studies show that the waste characteristics favor solubilization and mobilization of inorganic contaminants. The geochemical distribution of soil pollution is studied by the application of the Bayesian Maximum Entropy (BME) procedure, a versatile extension of geostatistics which allows merging spatial and temporal estimations in a single model. Results reveal a correlation range of contaminants concentrations up to 5000 m and indicate a potential forecasting range of up to five years. Inspection of the produced spatiotemporal maps indicates that the whole study area is contaminated by As and various heavy metals, a situation which seems to be more or less stable over time.     

Molecular signatures that correlate with induction of lens regeneration in newts: lessons from proteomic analysis

Background

Amphibians have the remarkable ability to regenerate missing body parts. After complete removal of the eye lens, the dorsal but not the ventral iris will transdifferentiate to regenerate an exact replica of the lost lens. We used reverse-phase nano-liquid chromatography followed by mass spectrometry to detect protein concentrations in dorsal and ventral iris 0, 4, and 8 days post-lentectomy. We performed gene expression comparisons between regeneration and intact timepoints as well as between dorsal and ventral iris.

Results

Our analysis revealed gene expression patterns associated with the ability of the dorsal iris for transdifferentiation and lens regeneration. Proteins regulating gene expression and various metabolic processes were enriched in regeneration timepoints. Proteins involved in extracellular matrix, gene expression, and DNA-associated functions like DNA repair formed a regeneration-related protein network and were all up-regulated in the dorsal iris. In addition, we investigated protein concentrations in cultured dorsal (transdifferentiation-competent) and ventral (transdifferentiation-incompetent) iris pigmented epithelial (IPE) cells. Our comparative analysis revealed that the ability of dorsal IPE cells to keep memory of their tissue of origin and transdifferentiation is associated with the expression of proteins that specify the dorso-ventral axis of the eye as well as with proteins found highly expressed in regeneration timepoints, especially 8 days post-lentectomy.

Conclusions

The study deepens our understanding in the mechanism of regeneration by providing protein networks and pathways that participate in the process.

     

“cAMP Sponge”: A Buffer for Cyclic Adenosine 3′, 5′-Monophosphate

Background

While intracellular buffers are widely used to study calcium signaling, no such tool exists for the other major second messenger, cyclic AMP (cAMP).

Methods/Principal Findings

Here we describe a genetically encoded buffer for cAMP based on the high-affinity cAMP-binding carboxy-terminus of the regulatory subunit RIβ of protein kinase A (PKA). Addition of targeting sequences permitted localization of this fragment to the extra-nuclear compartment, while tagging with mCherry allowed quantification of its expression at the single cell level. This construct (named “cAMP sponge”) was shown to selectively bind cAMP in vitro. Its expression significantly suppressed agonist-induced cAMP signals and the downstream activation of PKA within the cytosol as measured by FRET-based sensors in single living cells. Point mutations in the cAMP-binding domains of the construct rendered the chimera unable to bind cAMP in vitro or in situ. Cyclic AMP sponge was fruitfully applied to examine feedback regulation of gap junction-mediated transfer of cAMP in epithelial cell couplets.

Conclusions

This newest member of the cAMP toolbox has the potential to reveal unique biological functions of cAMP, including insight into the functional significance of compartmentalized signaling events.     

Lipid synthesized by micro‐algae grown in laboratory‐ and industrial‐scale bioreactors

Tetraselmis sp. and Nannochloropsis oculata, cultivated in industrial‐scale bioreactors, produced 2.33 and 2.44% w/w lipid (calculated as the sum of fatty acid methyl esters) in dry biomass, respectively. These lipids contained higher amounts of neutral lipids and glycolipids plus sphingolipids, than phospholipids. Lipids of Tetraselmis sp. were characterized by the presence of eicosapentaenoic acid (that was located mainly in phospholipids), and octadecatetraenoic acid (that was equally distributed among lipid fractions), while these fatty acids were completely absent in N. oculata lipids. Additionally, lipids produced by 16 newly isolated strains from Greek aquatic environments (cultivated in flask reactors) were studied. The highest percentage of lipids was found in Prorocentrum triestinum (3.69% w/w) while the lowest in Prymnesium parvum (0.47% w/w). Several strains produced lipids rich in eicosapentaenoic and docosahexaenoic acids. For instance, docosahexaenoic acid was found in high percentages in lipids of Amphidinium sp. S1, P. parvum, Prorocentrum minimum and P. triestinum, while lipids produced by Asterionella sp. (?) S2 contained eicosapentaenoic acid in high concentration. These lipids, containing ω‐3‐long‐chain polyunsaturated fatty acids, have important applications in the food and pharmaceutical industries and in aquaculture.     

Beach sand oil spills select for generalist microbial populations

The specialization-disturbance hypothesis predicts that, in the event of a disturbance, generalists are favored, while specialists are selected against. This hypothesis has not been rigorously tested in microbial systems and it remains unclear to what extent it could explain microbial community succession patterns following perturbations. Previous field observations of Pensacola Beach sands that were impacted by the Deepwater Horizon (DWH) oil spill provided evidence in support of the specialization-disturbance hypothesis. However, ecological drift as well as uncounted environmental fluctuations (e.g., storms) could not be ruled out as confounding factors driving these field results. In this study, the specialization-disturbance hypothesis was tested on beach sands, disturbed by DWH crude oil, ex situ in closed laboratory advective-flow chambers that mimic in situ conditions in saturated beach sediments. The chambers were inoculated with weathered DWH oil and unamended chambers served as controls. The time series of shotgun metagenomic and 16S rRNA gene amplicon sequence data from a two-month long incubation showed that functional diversity significantly increased while taxonomic diversity significantly declined, indicating a decrease in specialist taxa. Thus, results from this laboratory study corroborate field observations, providing verification that the specialization-disturbance hypothesis can explain microbial succession patterns in crude oil impacted beach sands.Subject terms: Microbial ecology, Community ecology     

Effect of phosphorus dendrimers on DMPC lipid membranes

Large unilamellar liposomes and multilamellar vesicles consisting of DMPC interacted with cationic phosphorus-containing dendrimers CPDs G3 and G4. DSC and ζ-potential measurements have shown that liposomal-dendrimeric molecular recognition probably occurs due to the interaction between the complementary surface groups. Calorimetric studies indicate that the enthalpy of the transition of the lipids that interact with CPDs is dependent on the dendrimers generation. These results can be used in order to rationally design mixed modulatory liposomal locked-in dendrimeric, drug delivery nano systems.