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Pamplona, Spain

San Roman B.,Institute Agrobiotecnologia Csic Upna Gobierno Of Navarra | De Andres X.,Institute Agrobiotecnologia Csic Upna Gobierno Of Navarra | Munoz P.-M.,Institute Agrobiotecnologia Csic Upna Gobierno Of Navarra | Obregon P.,Institute Agrobiotecnologia Csic Upna Gobierno Of Navarra | And 9 more authors.
Vaccine | Year: 2012

The development of effective vaccines against HIV-1 infection constitutes one of the major challenges in viral immunology. One of the protein candidates in vaccination against this virus is p24, since it is a conserved HIV antigen that has cytotoxic and helper T cell epitopes as well as B cell epitopes that may jointly confer enhanced protection against infection when used in immunization-challenge approaches. In this context, the adjuvant effect of EDA (used as EDAp24 fusion protein) and poly(I:C), as agonists of TLR4 and TLR3, respectively, was assessed in p24 immunizations using a recombinant Listeria monocytogenes HIV-1 Gag proteins (Lm-Gag, where p24 is the major antigen) for challenge in mice. Immunization with EDAp24 fusion protein together with poly(I:C) adjuvant induced a specific p24 IFN-γ production (Th1 profile) as well as protection against a Lm-Gag challenge, suggesting an additive or synergistic effect between both adjuvants. The combination of EDA (as a fusion protein with the antigen, which may favor antigen targeting to dendritic cells through TLR4) and poly(I:C) could thus be a good adjuvant candidate to enhance the immune response against HIV-1 proteins and its use may open new ways in vaccine investigations on this virus. © 2012 Elsevier Ltd. Source

Asensio A.C.,Public University of Navarra | Asensio A.C.,Centro Jeronimo Of Ayanz | Gil-Monreal M.,Public University of Navarra | Pires L.,Public University of Navarra | And 3 more authors.
Journal of Plant Physiology | Year: 2012

Three main families of SODs in plants may be distinguished according to the metal in the active center: CuZnSODs, MnSOD, and FeSOD. CuZnSODs have two sub-families localized either in plant cell cytosol or in plastids, the MnSOD family is essentially restricted to mitochondria, and the FeSOD enzyme family has been typically localized into the plastid. Here, we describe, based on a phylogenetic tree and experimental data, the existence of two FeSOD sub-families: a plastidial localized sub-family that is universal to plants, and a cytosolic localized FeSOD sub-family observed in determinate-forming nodule legumes. Anti-cytosolic FeSOD (cyt_FeSOD) antibodies were employed, together with a novel antibody raised against plastidial FeSOD (p_FeSOD). Stress conditions, such as nitrate excess or drought, markedly increased cyt_FeSOD contents in soybean tissues. Also, cyt_FeSOD content and activity increased with age in both soybean and cowpea plants, while the cyt_CuZnSOD isozyme was predominant during early stages. p_FeSOD in leaves decreased with most of the stresses applied, but this isozyme markedly increased with abscisic acid in roots. The great differences observed for p_FeSOD and cyt_FeSOD contents in response to stress and aging in plant tissues reveal distinct functionality and confirm the existence of two immunologically differentiated FeSOD sub-families. The in-gel FeSOD activity patterns showed a good correlation to cyt_FeSOD contents but not to those of p_FeSOD. This indicates that cyt_FeSOD is the main active FeSOD in soybean and cowpea tissues. The diversity of functions associated with the complexity of FeSOD isoenzymes depending of the location is discussed. © 2012 Elsevier GmbH. Source

Ariz I.,Public University of Navarra | Asensio A.C.,Public University of Navarra | Asensio A.C.,Centro Jeronimo Of Ayanz | Zamarreno A.M.,Inabonos Roullier Group | And 3 more authors.
Physiologia Plantarum | Year: 2013

An understanding of the mechanisms underlying ammonium (NH4 +) toxicity in plants requires prior knowledge of the metabolic uses for nitrogen (N) and carbon (C). We have recently shown that pea plants grown at high NH4 + concentrations suffer an energy deficiency associated with a disruption of ionic homeostasis. Furthermore, these plants are unable to adequately regulate internal NH4 + levels and the cell-charge balance associated with cation uptake. Herein we show a role for an extra-C application in the regulation of C-N metabolism in NH4 +-fed plants. Thus, pea plants (Pisum sativum) were grown at a range of NH4 + concentrations as sole N source, and two light intensities were applied to vary the C supply to the plants. Control plants grown at high NH4 + concentration triggered a toxicity response with the characteristic pattern of C-starvation conditions. This toxicity response resulted in the redistribution of N from amino acids, mostly asparagine, and lower C/N ratios. The C/N imbalance at high NH4 + concentration under control conditions induced a strong activation of root C metabolism and the upregulation of anaplerotic enzymes to provide C intermediates for the tricarboxylic acid cycle. A high light intensity partially reverted these C-starvation symptoms by providing higher C availability to the plants. The extra-C contributed to a lower C4/C5 amino acid ratio while maintaining the relative contents of some minor amino acids involved in key pathways regulating the C/N status of the plants unchanged. C availability can therefore be considered to be a determinant factor in the tolerance/sensitivity mechanisms to NH4 + nutrition in plants. © Physiologia Plantarum 2012. Source

Tellechea E.,Centro Jeronimo Of Ayanz | Tellechea E.,Public University of Navarra | Cornago I.,Centro Jeronimo Of Ayanz | Ciaurriz P.,Centro Jeronimo Of Ayanz | And 3 more authors.
IEEE Transactions on Nanobioscience | Year: 2012

Superoxide dismutase enzymes (SODs) are an essential part of the first line of cellular defense system against free radicals species. They catalyze the dismutation of superoxide radicals into oxygen and hydrogen peroxide. Although several studies have examined the attachment of superoxide dismutases to nanoparticles and nanostructures, never has been used a member of the Fe/MnSOD family. In this study, the behavior of plant origin FeSOD enzyme on three different nanopatterned surfaces was investigated as a function of covalent and electrostatic binding. Fluorescence microscopy was used to demonstrate that the protein is attached only to the gold layer. We also examined the activity of SOD by a colorimetric assay, and we have shown that the enzyme remains active after attachment to the three different surfaces under both kind of binding (electrostatic and covalent). This methodology could be useful for those who want to functionalize nanostructures with a SOD enzyme and test the activity. This process could be of great interest for the development of peroxynitrite and superoxide biosensors. © 2011 IEEE. Source

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