Prokaryotic aminopeptidase activity along a continuous salinity gradient in a hypersaline coastal lagoon (the Coorong, South Australia)

The relation between climatic parameters (relative air humidity) and the water activity of the Urmia Sea water determines the possible maximum evaporation of the lake. Using the Pitzer thermodynamic approach, the activity of the Urmia Lake water during evaporation was calculated and compared to the present relative air humidity above the water. Present climatic conditions allow the Urmia Sea water to evaporate down to water with activity of 0.55, corresponding to the lowest air humidity measured over the lake. This water activity falls in the range of halite precipitation, while carnalite precipitation starts at somewhat lower (a H₂O = 0.499) point. Our dynamic model predicts that for air humidity as low as 55% (reflecting present climate conditions), the Urmia Sea level may drop to as low as 1270 m (i. e., 1270 m above mean sea level). At that point, the lake water volume will have a volume of 11 km³. For the sake of comparison, at the beginning of 1990, the level of the lake was 1275 m, its volume was 25 km³, and its surface area was 5145 km².     

Immigrational Background Affects the Effectiveness of a School‐based Overweight Prevention Program Promoting Water Consumption

We tested whether a simple overweight prevention program promoting water consumption in elementary schools is equally effective in children with an immigrational background (MIG) and in those without (non‐MIG). Thus, a secondary analysis of a controlled cluster trial, lasting one school year, was conducted. Thirty‐two elementary schools located in low socioeconomic districts in two German cities were included. Of the 2,950 school children analyzed, 1,306 were MIG children. Water fountains were installed in the schools of the intervention group (IG) and teachers held lessons to promote water consumption. Control schools (control group (CG)) did not receive any intervention. Before and after intervention, body weight and height was measured. Overweight was defined by age‐ and sex‐specific BMI cutoffs that are linked to an adult BMI of 25 kg/m². Beverage consumption was assessed in questionnaires. Modification of intervention effects by immigrational background was tested by interaction terms. The immigrational background modified the intervention effect on prevalence and remission of overweight (interaction term: P = 0.03 and P = 0.02), but not on the incidence of overweight (P = 0.06). After intervention, the risk of being overweight was reduced in the IG compared to the CG among non‐MIG (odds ratio = 0.51, 95% confidence interval (CI): 0.31–0.83), but not among MIG children (odds ratio = 1.02, 95% CI: 0.63–1.65). After intervention, water consumption significantly increased in the IG equally among both, non‐MIG and MIG, by ～1 glass/day. A simple school‐based intervention promoting water consumption prevented overweight in non‐MIG children, but failed in MIG children. Different beverage consumption, among other lifestyle factors, may account for this effect but scientific discussion remains open.     

A long peptide from MELOE-1 contains multiple HLA class II T cell epitopes in addition to the HLA-A*0201 epitope: an attractive candidate for melanoma vaccination

CD4⁺ T cells contribute importantly to the antitumor T cell response, and thus, long peptides comprising CD4 and CD8 epitopes may be efficient cancer vaccines. We have previously identified an overexpressed antigen in melanoma, MELOE-1, presenting a CD8⁺ T cell epitope, MELOE-1_36–44, in the HLA-A*0201 context. A T cell repertoire against this epitope is present in HLA-A*0201+ healthy subjects and melanoma patients and the adjuvant injection of TIL containing MELOE-1 specific CD8⁺ T cells to melanoma patients was shown to be beneficial. In this study, we looked for CD4⁺ T cell epitopes in the vicinity of the HLA-A*0201 epitope. Stimulation of PBMC from healthy subjects with MELOE-1_26–46 revealed CD4 responses in multiple HLA contexts and by cloning responsive CD4⁺ T cells, we identified one HLA-DRβ1*1101-restricted and one HLA-DQβ1*0603-restricted epitope. We showed that the two epitopes could be efficiently presented to CD4⁺ T cells by MELOE-1-loaded dendritic cells but not by MELOE-1+ melanoma cell-lines. Finally, we showed that the long peptide MELOE-1_22–46, containing the two optimal class II epitopes and the HLA-A*0201 epitope, was efficiently processed by DC to stimulate CD4⁺ and CD8⁺ T cell responses in vitro, making it a potential candidate for melanoma vaccination.     

"Immunetworks", intersecting circuits and dynamics

This paper proposes a study of biological regulation networks based on a multi-level strategy. Given a network, the first structural level of this strategy consists in analysing the architecture of the network interactions in order to describe it. The second dynamical level consists in relating the patterns found in the architecture to the possible dynamical behaviours of the network. It is known that circuits are the patterns that play the most important part in the dynamics of a network in the sense that they are responsible for the diversity of its asymptotic behaviours. Here, we pursue further this idea and argue that beyond the influence of underlying circuits, intersections of circuits also impact significantly on the dynamics of a network and thus need to be payed special attention to. For some genetic regulation networks involved in the control of the immune system (“immunetworks”), we show that the small number of attractors can be explained by the presence, in the underlying structures of these networks, of intersecting circuits that “inter-lock”.     

Expression of a new chimeric protein with a highly repeated sequence in tobacco cells

In wheat, the high-molecular weight (HMW) glutenin subunits are known to contribute to gluten viscoelasticity, and show some similarities to elastomeric animal proteins as elastin. When combining the sequence of a glutenin with that of elastin is a way to create new chimeric functional proteins, which could be expressed in plants. The sequence of a glutenin subunit was modified by the insertion of several hydrophobic and elastic motifs derived from elastin (elastin-like peptide, ELP) into the hydrophilic repetitive domain of the glutenin subunit to create a triblock protein, the objective being to improve the mechanical (elastomeric) properties of this wheat storage protein. In this study, we investigated an expression model system to analyze the expression and trafficking of the wild-type HMW glutenin subunit (GS_W) and an HMW glutenin subunit mutated by the insertion of elastin motifs (GS_M-ELP). For this purpose, a series of constructs was made to express wild-type subunits and subunits mutated by insertion of elastin motifs in fusion with green fluorescent protein (GFP) in tobacco BY-2 cells. Our results showed for the first time the expression of HMW glutenin fused with GFP in tobacco protoplasts. We also expressed and localized the chimeric protein composed of plant glutenin and animal elastin-like peptides (ELP) in BY-2 protoplasts, and demonstrated its presence in protein body-like structures in the endoplasmic reticulum. This work, therefore, provides a basis for heterologous production of the glutenin-ELP triblock protein to characterize its mechanical properties.