Abscisic acid and the herbicide safener cyprosulfamide cooperatively enhance abiotic stress tolerance in rice

Plants adapt to abiotic stress by undergoing diverse biochemical and physiological changes that involve hormone-dependent signaling pathways. The effects of plant hormones can be mimicked by exogenous chemical regulators such as herbicide safeners, which not only enhance stress tolerance but also confer hormetic benefits such as increased vigor and yield. In this study, rice plants growing in normal and saline soils were exposed to abscisic acid (ABA), the safener cyprosulfamide or both compounds together. We found that cyprosulfamide, either alone or in combination with ABA, protected the plants from salinity stress and induced vigorous growth, including the formation of new tillers and early flowering. Proteomic analysis identified several proteins that were induced by stress and/or the chemical treatments, including the late embryogenesis abundant protein OsLEA3, a putative mitochondrial translocase and a putative fumarylacetoacetate hydrolase. The corresponding gene s were induced by stress and/or the individual chemical treatments, but expression dropped back when the stress was removed. However, the combination of ABA and cyprosulfamide prolonged the expression of all three genes beyond the stress period, and allowed the plants to maintain their enhanced growth characteristics. These data support a model involving cooperation between the cyprosulfamide and ABA signaling pathways. Accordingly, it was found that cyprosulfamide induces ABA synthesis more robustly than salinity stress, allowing the two regulators to converge on certain downstream target genes. We discuss the impact of our results on current models for the hormonal regulation of stress response pathways in rice and other plants

Monoclonal Antibody AP3 Binds Galactomannan Antigens Displayed by the Pathogens Aspergillus flavus, A. fumigatus, and A. parasiticus

Aspergillus fumigatus and A. flavus are the fungal pathogens responsible for most cases of invasive aspergillosis (IA). Early detection of the circulating antigen galactomannan (GM) in serum allows the prompt application of effective antifungal therapy, thus improving the survival rate of IA patients. However, the use of monoclonal antibodies (mAbs) for the diagnosis of IA is often associated with false positives due to cross-reaction with bacterial polysaccharides. More specific antibodies are therefore needed. Here we describe the characterization of the Aspergillus-specific mAb AP3 (IgG1κ), including the precise identification of its corresponding antigen. The antibody was generated using A. parasiticus cell wall fragments and was shown to bind several Aspergillus species. Immunofluorescence microscopy revealed that AP3 binds a cell wall antigen, but immunoprecipitation and enzyme-linked immunosorbent assays showed that the antigen is also secreted into the culture medium. The inability of AP3 to bind the A. fumigatus galactofuranose (Galf )-deficient mutant ΔglfA confirmed that Galf residues are part of the epitope. Several lines of evidence strongly indicated that AP3 recognizes the Galf residues of O-linked glycans on Aspergillus proteins. Glycoarray analysis revealed that AP3 recognizes oligo-[β-D-Galf-1,5] sequences containing four or more residues with longer chains more efficiently. We also showed that AP3 captures GM in serum, suggesting it may be useful as a diagnostic tool for patients with IA

Improvement of a fermentation process for the production of two PfAMA1-DiCo-based malaria vaccine candidates in Pichia pastoris

Pichia pastoris is a simple and powerful expression platform that has the ability to produce a wide variety of recombinant proteins, ranging from simple peptides to complex membrane proteins. A well-established fermentation strategy is available comprising three main phases: a batch phase, followed by a glycerol fed-batch phase that increases cell density, and finally an induction phase for product expression using methanol as the inducer. We previously used this three-phase strategy at the 15-L scale to express three different AMA1-DiCo-based malaria vaccine candidates to develop a vaccine cocktail. For two candidates, we switched to a two-phase strategy lacking the intermediate glycerol fed-batch phase. The new strategy not only provided a more convenient process flow but also achieved 1.5-fold and 2.5-fold higher space-time yields for the two candidates, respectively, and simultaneously reduced the final cell mass by a factor of 1.3, thus simplifying solid-liquid separation. This strategy also reduced the quantity of host cell proteins that remained to be separated from the two vaccine candidates (by 34% and 13%, respectively), thus reducing the effort required in the subsequent purification steps. Taken together, our new fermentation strategy increased the overall fermentation performance for the production of two different AMA1-DiCo-based vaccine candidates

Principles and Techniques for Sensor Data Fusion

This paper concerns a problem which is basic to perception: the integration of perceptual information into a coherent description of the world. In this paper we present perception as a process of dynamically maintaining a model of the local external environment. Fusion of perceptual information is at the heart of this process

Macrophage Bactericidal Activities against <i>Staphylococcus aureus</i> Are Enhanced <i>In Vivo</i> by Selenium Supplementation in a Dose-Dependent Manner

<div><p>Background</p><p>Dietary selenium is of fundamental importance to maintain optimal immune function and enhance immunity during infection. To this end, we examined the effect of selenium on macrophage bactericidal activities against <i>Staphylococcus aureus</i>.</p><p>Methods</p><p>Assays were performed in golden Syrian hamsters and peritoneal macrophages cultured with <i>S</i>. <i>aureus</i> and different concentrations of selenium.</p><p>Results</p><p>Infected and selenium-supplemented animals have significantly decreased levels of serum nitric oxide (NO) production when compared with infected but non-selenium-supplemented animals at day 7 post-infection (<i>p</i> < 0.05). A low dose of 5 ng/mL selenium induced a significant decrease in macrophage NO production, but significant increase in hydrogen peroxide (H₂O₂) levels (respectively, <i>p</i> = 0.009, <i>p</i> < 0.001). The NO production and H₂O₂ levels were significantly increased with increasing concentrations of selenium; the optimal macrophage activity levels were reached at 20 ng/mL. The concentration of 5 ng/mL of selenium induced a significant decrease in the bacterial arginase activity but a significant increase in the macrophage arginase activity. The dose of 20 ng/mL selenium induced a significant decrease of bacterial growth (<i>p</i> < 0.0001) and a significant increase in macrophage phagocytic activity, NO production/arginase balance and <i>S</i>. <i>aureus</i> killing (for all comparisons, <i>p</i> < 0.001).</p><p>Conclusions</p><p>Selenium acts in a dose-dependent manner on macrophage activation, phagocytosis and bacterial killing suggesting that inadequate doses may cause a loss of macrophage bactericidal activities and that selenium supplementation could enhance the <i>in vivo</i> control of immune response to <i>S</i>. <i>aureus</i>.</p></div