Person:
Veramendi Charola, Jon

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Veramendi Charola

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Jon

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Agronomía, Biotecnología y Alimentación

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IMAB. Research Institute for Multidisciplinary Applied Biology

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0000-0002-3214-213X

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539

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Now showing 1 - 3 of 3
  • PublicationOpen Access
    Heat treatment alleviates the growth and photosynthetic impairment of transplastomic plants expressing Leishmania infantum Hsp83-Toxoplasma gondii SAG1 fusion protein
    (Elsevier, 2019) Corigliano, Mariana G.; Albarracín, Romina M.; Vilas, Juan M.; Sánchez López, Edwin F.; Bengoa Luoni, Sofía A.; Deng, Bin; Farrán Blanch, Inmaculada; Veramendi Charola, Jon; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
    Previously, we showed that transplastomic tobacco plants expressing the LiHsp83-SAG1 fusion protein displayed a chlorotic phenotype and growth retardation, while plants expressing the SAG1 and GRA4 antigens alone did not. We conducted a comprehensive examination of the metabolic and photosynthetic parameters that could be affecting the normal growth of LiHsp83-SAG1 plants in order to understand the origin of these pleiotropic effects. These plants presented all photosynthetic pigments and parameters related to PSII efficiency significantly diminished. However, the expression ofCHLI, RSSU and LHCa/b genes did not show significant differences between LiHsp83-SAG1 and control plants. Total protein, starch, and soluble sugar contents were also greatly reduced in LiHsp83-SAG1 plants. Since Hsp90 s are constitutively expressed at much higher concentrations at high temperatures, we tested if the fitness of LiHsp83-SAG1 over-expressing LiHsp83 would improve after heat treatment. LiHsp83-SAG1 plants showed an important alleviation of their phenotype and an evident recovery of the PSII function. As far as we know, this is the first report where it is demonstrated that a transplastomic line performs much better at higher temperatures. Finally, we detected that LiHsp83-SAG1 protein could be binding to key photosynthesis-related proteins at 37 °C. Our results suggest that the excess of this molecular chaperone could benefit the plant in a possible heat shock and prevent the expected denaturation of proteins. However, the LiHsp83-SAG1 protein content was weakly decreased in heat-treated plants. Therefore, we cannot rule out that the alleviation observed at 37 °C may be partially due to a reduction of the levels of the recombinant protein.
  • PublicationOpen Access
    The fusion of Toxoplasma gondii SAG1 vaccine candidate to Leishmania infantum heat shock protein 83-kDa improves expression levels in tobacco chloroplasts
    (Wiley, 2015) Albarracín, Romina M.; Laguía Becher, M; Farrán Blanch, Inmaculada; Sander, Valeria; Corigliano, Mariana G.; Yácono, María del L.; Pariani, S; Sánchez López, Edwin F.; Veramendi Charola, Jon; Clemente, Marina; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
    Chloroplast transformation technology has emerged as an alternative platform offering many advantages over nuclear transformation. SAG1 is the main surface antigen of the intracellular parasite Toxoplasma gondii and a promising candidate to produce an anti-T. gondii vaccine. The aim of this study is to investigate the expression of SAG1 using chloroplast transformation technology in tobacco plants. In order to improve its expression in transplastomic plants, we also expressed the 90-kDa heat shock protein of Leishmania infantum (LiHsp83) as a carrier for SAG1 antigen. SAG1 protein accumulation in transplastomic plants was approximately 0.1-0.2 µg per gram of fresh weight (FW). Fusion of SAG1 to LiHsp83 significantly increased the level of SAG1 accumulation in tobacco chloroplasts (by up to 500-fold). We also evaluated the functionality of the chLiHsp83-SAG1. Three human seropositive samples reacted with SAG1 expressed in transplastomic chLiHsp83-SAG1 plants. Oral immunization with chLiHsp83-SAG1 elicited a significant reduction of the cyst burden that correlated with an increase of SAG1-specific antibodies. We propose the fusion of foreign proteins to LiHsp83 as a novel strategy to increase the expression level of the recombinant proteins using chloroplast transformation technology, thus addressing one of the current challenges for this approach in antigen protein production.
  • PublicationOpen Access
    A chloroplast-derived Toxoplasma gondiiGRA4 antigen used as an oral vaccine protects against toxoplasmosis in mice
    (Wiley, 2012) Yácono, María del L.; Farrán Blanch, Inmaculada; Becher, Melina L.; Sander, Valeria; Sánchez, Vanesa R.; Martín, Valentina; Veramendi Charola, Jon; Clemente, Marina; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
    The parasitic protozoan Toxoplasma gondii, the causal agent of toxoplasmosis, can infect most mammals and birds. In human medicine, T. gondii can cause complications in pregnant women and immunodeficient individuals, while in veterinary medicine, T. gondii infection has economic importance due to abortion and neonatal loss in livestock. Thus, the development of an effective anti‐Toxoplasma vaccine would be of great value. In this study, we analysed the expression of T. gondii GRA4 antigen by chloroplast transformation (chlGRA4) in tobacco plants and evaluated the humoral and cellular responses and the grade of protection after oral administration of chlGRA4 in a murine model. The Western blot analysis revealed a specific 34‐kDa band mainly present in the insoluble fractions. The chlGRA4 accumulation levels were approximately 6 μg/g of fresh weight (equivalent to 0.2% of total protein). Oral immunization with chlGRA4 resulted in a decrease of 59% in the brain cyst load of mice compared to control mice. ChlGRA4 immunization elicited both a mucosal immune response characterized by the production of specific IgA, and IFN‐γ, IL‐4 and IL‐10 secretion by mesenteric lymph node cells, and a systemic response in terms of GRA4‐specific serum antibodies and secretion of IFN‐γ, IL‐4 and IL‐10 by splenocytes. Our results indicate that oral administration of chlGRA4 promotes the elicitation of both mucosal and systemic balanced Th1/Th2 responses that control Toxoplasma infection, reducing parasite loads.