Institute Ciencia Y Tecnologia Dr Cesar Milstein

Buenos Aires, Argentina

Institute Ciencia Y Tecnologia Dr Cesar Milstein

Buenos Aires, Argentina
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Foscaldi S.,Institute Ciencia Y Tecnologia Dr Cesar Milstein | D'Antuono A.,Institute Ciencia Y Tecnologia Dr Cesar Milstein | Noval M.G.,Fundacion Instituto Leloir | Noval M.G.,New York University | And 3 more authors.
Journal of Virology | Year: 2017

Mammarenaviruses are enveloped viruses with a bisegmented negativestranded RNA genome that encodes the nucleocapsid protein (NP), the envelope glycoprotein precursor (GPC), the RNA polymerase (L), and a RING matrix protein (Z). Viral proteins are synthesized from subgenomic mRNAs bearing a capped 5' untranslated region (UTR) and lacking 3' poly(A) tail. We analyzed the translation strategy of Tacaribe virus (TCRV), a prototype of the New World mammarenaviruses. A virus-like transcript that carries a reporter gene in place of the NP open reading frame and transcripts bearing modified 5' and/or 3' UTR were evaluated in a cellbased translation assay. We found that the presence of the cap structure at the 5' end dramatically increases translation efficiency and that the viral 5' UTR comprises stimulatory signals while the 3' UTR,specifically the presence of a terminal C+G-rich sequence and/or a stem-loop structure, down-modulates translation. Additionally, translation was profoundly reduced in eukaryotic initiation factor (eIF) 4G-inactivated cells, whereas depletion of intracellular levels of eIF4E had less impact on virus-like mRNA translation than on a cell-like transcript. Translation efficiency was independent of NP expression or TCRV infection. Our results indicate that TCRV mRNAs are translated using a cap-dependent mechanism, whose efficiency relies on the interplay between stimulatory signals in the 5' UTR and a negative modulatory element in the 3' UTR. The low dependence on eIF4E suggests that viral mRNAs may engage yet-unknown noncanonical host factors for a cap-dependent initiation mechanism. © 2017 American Society for Microbiology.

Morgan K.L.,University of Liverpool | Handel I.G.,University of Edinburgh | Tanya V.N.,Institute of Agricultural Research for Development | Tanya V.N.,Ministry of Scientific Research and Innovation | And 9 more authors.
Emerging Infectious Diseases | Year: 2014

Herdsman-reported disease prevalence is widely used in veterinary epidemiologic studies, especially for diseases with visible external lesions; however, the accuracy of such reports is rarely validated. Thus, we used latent class analysis in a Bayesian framework to compare sensitivity and specificity of herdsman reporting with virus neutralization testing and use of 3 nonstructural protein ELISAs for estimates of foot-and-mouth disease (FMD) prevalence on the Adamawa plateau of Cameroon in 2000. Herdsman-reported estimates in this FMD-endemic area were comparable to those obtained from serologic testing. To harness to this cost-effective resource of monitoring emerging infectious diseases, we suggest that estimates of the sensitivity and specificity of herdsmen reporting should be done in parallel with serologic surveys of other animal diseases. © 2014, Centers for Disease Control and Prevention (CDC). All rights reserved.

Sarute N.,University of the Republic of Uruguay | Calderon M.G.,Institute Ciencia Y Tecnologia Dr Cesar Milstein | Perez R.,University of the Republic of Uruguay | La Torre J.,Institute Ciencia Y Tecnologia Dr Cesar Milstein | And 3 more authors.
PLoS ONE | Year: 2013

Canine distemper virus (CDV; Paramyxoviridae, Morbillivirus) is the etiologic agent of a multisystemic infectious disease affecting all terrestrial carnivore families with high incidence and mortality in domestic dogs. Sequence analysis of the hemagglutinin (H) gene has been widely employed to characterize field strains, permitting the identification of nine CDV lineages worldwide. Recently, it has been established that the sequences of the fusion protein signal-peptide (Fsp) coding region are extremely variable, suggesting that analysis of its sequence might be useful for strain characterization studies. However, the divergence of Fsp sequences among worldwide strains and its phylogenetic resolution has not yet been evaluated. We constructed datasets containing the Fsp-coding region and H gene sequences of the same strains belonging to eight CDV lineages. Both datasets were used to evaluate their phylogenetic resolution. The phylogenetic analysis revealed that both datasets clustered the same strains into eight different branches, corresponding to CDV lineages. The inter-lineage amino acid divergence was fourfold greater for the Fsp peptide than for the H protein. The likelihood mapping revealed that both datasets display strong phylogenetic signals in the region of well-resolved topologies. These features indicate that Fsp-coding region sequence analysis is suitable for evolutionary studies as it allows for straightforward identification of CDV lineages. © 2013 Sarute et al.

Mansilla F.C.,Institute Ciencia Y Tecnologia Dr Cesar Milstein | Mansilla F.C.,Instituto Nacional de Tecnologia Agropecuaria | Franco-Mahecha O.L.,Institute Ciencia Y Tecnologia Dr Cesar Milstein | Franco-Mahecha O.L.,Instituto Nacional de Tecnologia Agropecuaria | And 7 more authors.
Vaccine | Year: 2012

Efficient, cost-effective and safe Th1-immunity-inducing vaccine formulations are paramount for achieving protection against Neospora caninum. In this study, a new adjuvant (Providean-AVEC ®) was used in the development of a N. caninum vaccine and evaluated in a mouse model. Soluble N. caninum tachyzoite native protein extract (sNcAg) was selected as vaccine antigen based on its capacity to activate production of pro-inflammatory cytokines on dendritic cells. Vaccines containing 4 and 0.4μg of sNcAg, and Providean-AVEC ®, ISCOM-Matrix or aluminum hydroxide (Alum) were tested in BALB/c mice. While mice vaccinated with 4μg of sNcAg+Providean-AVEC ® developed specific antibodies shortly after the first dose, the rest of the high antigen payload formulations only induced seroconversion after the booster. Mice immunized with the high payload ISCOM vaccine (4μg sNcAg) or with either low or high payload Providean-AVEC ® formulations (0.4μg and 4μg sNcAg, respectively) elicited higher IgG2a than IgG1 serum levels, and IFN-γ anamnestic responses with a Th1-cytokine biased profile. These animals had no histological signs of cerebral lesions and parasite burden assessed by quantitative real-time PCR was not detected. Vaccine preparations including Providean-AVEC ® as adjuvant limited N. canimum multiplication even with only a tenth of antigen payload compared to vaccines containing other adjuvants. Using adjuvants to specifically activate dendritic cells, combined with a careful antigen selection can enhance cellular responses to inert N. caninum vaccines. © 2011 Elsevier Ltd.

El-Oirdi M.,Université de Sherbrooke | El-Rahman T.A.,Université de Sherbrooke | Rigano L.,Institute Ciencia Y Tecnologia Dr Cesar Milstein | El-Hadrami A.,University of Manitoba | And 4 more authors.
Plant Cell | Year: 2011

Plants have evolved sophisticated mechanisms to sense and respond to pathogen attacks. Resistance against necrotrophic pathogens generally requires the activation of the jasmonic acid (JA) signaling pathway, whereas the salicylic acid (SA) signaling pathway is mainly activated against biotrophic pathogens. SA can antagonize JA signaling and vice versa. Here, we report that the necrotrophic pathogen Botrytis cinerea exploits this antagonism as a strategy to cause disease development. We show that B. cinerea produces an exopolysaccharide, which acts as an elicitor of the SA pathway. In turn, the SA pathway antagonizes the JA signaling pathway, thereby allowing the fungus to develop its disease in tomato (Solanum lycopersicum). SA-promoted disease development occurs through Nonexpressed Pathogen Related1. We also show that the JA signaling pathway required for tomato resistance against B. cinerea is mediated by the systemin elicitor. These data highlight a new strategy used by B. cinerea to overcome the plant's defense system and to spread within the host. © 2011 American Society of Plant Biologists. All rights reserved.

Inigo S.,CONICET | Inigo S.,National University of Quilmes | Giraldez A.N.,CONICET | Giraldez A.N.,Institute Ciencia Y Tecnologia Dr Cesar Milstein | And 3 more authors.
Plant Physiology | Year: 2012

The Mediator complex is a greater than 1-megadalton complex, composed of about 30 subunits and found in most eukaryotes, whose main role is to transmit signals from DNA-bound transcription factors to RNA Polymerase II. The proteasome is emerging as an important regulator of transcription during both initiation and elongation. It is increasing the number of cases where the proteolysis of transcriptional activators by the proteasome activates their function. This counterintuitive phenomenon was called "activation by destruction." Here, we show that, in Arabidopsis (Arabidopsis thaliana), PHYTOCHROME AND FLOWERING TIME1 (PFT1), the MEDIATOR25 (MED25) subunit of the plant Mediator complex, is degraded by the proteasome and that proteasome-mediated PFT1 turnover is coupled to its role in stimulating the transcription of FLOWERING LOCUS T, the plant florigen, which is involved in the process of flowering induction. We further identify two novel RING-H2 proteins that target PFT1 for degradation. We show that MED25-BINDING RING-H2 PROTEIN1 (MBR1) and MBR2 bind to PFT1 in yeast (Saccharomyces cerevisiae) and in vitro, and they promote PFT1 degradation in vivo, in a RING-H2- dependent way, typical of E3 ubiquitin ligases. We further show that both MBR1 and MBR2 also promote flowering by PFT1- dependent and -independent mechanisms. Our findings extend the phenomenon of activation by destruction to a Mediator subunit, adding a new mechanism by which Mediator subunits may regulate downstream genes in specific pathways. Furthermore, we show that two novel RING-H2 proteins are involved in the destruction of PFT1, adding new players to this process in plants. © 2012 American Society of Plant Biologists.

Capozzo A.V.,Institute Ciencia Y Tecnologia Dr Cesar Milstein | Martinez M.R.,Fundacion de Estudios en Virologia Animal | Schielen W.J.G.,Prionics Lelystad BV
Vaccine | Year: 2010

In many countries, foot and mouth disease (FMD) is controlled by vaccination and surveillance against non-capsid proteins (NCP); therefore vaccines are required not to induce antibodies against NCP. Vaccine purity is evaluated by repeated inoculation of naïve cattle, an expensive and time consuming protocol that raises several animal welfare concerns. We have developed an in process control filtration-assisted chemiluminometric immunoassay (FAL-ELISA), to detect and quantify NCP in vaccine-antigen batches regardless of its volume and composition. Samples are filtered through PVDF-filter microplates pre-coated with a monoclonal antibody against NCP. Filtration removes all unbound components in the sample and captured NCP are detected by anti-NCP conjugate followed by incubation with the substrate, luminol/peroxide. Analytical detection limit was 2. ng for purified NCP and 4. ng for vaccine-antigen batches spiked with NCP, which makes this assay sensitive enough to be applied to purity control of FMD vaccines. Vaccine components did not interfere with the antibody and substrate reactions in the assay. FAL-ELISA is an alternative for the in vivo tests, observing the objective to Replace, Reduce and Refine the use of animals for quality control of immunobiologicals. © 2010 Elsevier Ltd.

PubMed | Institute Ciencia Y Tecnologia Dr Cesar Milstein, Instituto Nacional de Tecnologia Agropecuaria and Tecnovax S.A
Type: | Journal: Experimental parasitology | Year: 2016

Profilins are actin-binding proteins that regulate the polymerization of actin filaments. In apicomplexan parasites, they are essential for invasion. Profilins also trigger the immune response of the host by activating TLRs on dendritic cells (DCs), inducing the production of pro-inflammatory cytokines. In this study we characterized for the first time the immune response and protection elicited by a vaccine based on Neospora caninum profilin in mice. Groups of eight BALB/c mice received either two doses of a recombinant N. caninum profilin expressed in Escherichia coli. (rNcPRO) or PBS, both formulated with an aqueous soy-based adjuvant enriched in TLR-agonists. Specific anti-profilin antibodies were detected in rNcPRO-vaccinated animals, mainly IgM and IgG3, which were consumed after infection. Splenocytes from rNcPRO-immunized animals proliferated after an in vitro stimulation with rNcPRO before and after challenge. An impairment of the cellular response was observed in NcPRO vaccinated and infected mice following an in vitro stimulation with native antigens of N. caninum, related to an increase in the percentage of CD4+CD25+FoxP3+. Two out of five rNcPRO-vaccinated challenged mice were protected; they were negative for parasite DNA in the brain and showed no histopathological lesions, which were found in all PBS-vaccinated animals. As a whole, our results provide evidence of a regulatory response elicited by immunization with rNcPRO, and suggest a role of profilin in the modulation and/or evasion of immune responses against N. caninum.

PubMed | Institute Ciencia Y Tecnologia Dr Cesar Milstein
Type: Journal Article | Journal: Biologicals : journal of the International Association of Biological Standardization | Year: 2012

Challenge with live pathogens could be substituted by serology for many veterinary diseases, however little progress has been made in the development of alternative batch vaccine potency tests for fish. This study reports the development and preliminary validation of a single-dilution filtration-assisted chemiluminometric immunoassay (SD FAL-ELISA) applied to measure anti Piscirickettsia salmonis IgM in individual or pooled serum and mucus samples. The assay was set up to test a single-dilution of the sample. Serum SD FAL-ELISA yielded a sensitivity of 90% and a specificity of 96%. SD FAL-ELISA was applied to evaluate pooled and individual samples from P.salmonis challenge assessments. Relative-light units values (RLU) obtained by SD FAL-ELISA were proportional to antibody levels in serum. RLU values obtained from pooled and individual serum samples increased with the observed relative percent survival (RPS) values, indicating a correlation between protection and specific IgM levels. Results obtained for specific IgM in mucus samples was not related to the RPS, but discriminated the vaccine that yielded high RPS (86.4%) from the others (40.9 and 54.5%). This is the first report on the development of an indirect high-throughput serological assessment for P.salmonis vaccine potency testing using both pooled or individual serum and cutaneous mucus samples.

PubMed | Fundacion Pablo Cassara, David Horn LLC, Institute Ciencia Y Tecnologia Dr Cesar Milstein and Immunotech S.A.
Type: Journal Article | Journal: PloS one | Year: 2015

CD56+ cells have been recognized as being involved in bridging the innate and acquired immune systems. Herein, we assessed the effect of two major classes of immunostimulatory oligonucleotides (ODNs), PyNTTTTGT and CpG, on CD56+ cells. Incubation of human peripheral blood mononuclear cells (hPBMC) with some of these ODNs led to secretion of significant amounts of interferon gamma (IFN-), tumor necrosis factor alpha (TNF-) and granulocyte/monocyte colony-stimulating factor (GM-CSF), but only if interleukin 2 (IL2) was present. IMT504, the prototype of the PyNTTTTGT ODN class, was the most active. GM-CSF secretion was very efficient when non-CpG ODNs with high T content and PyNTTTTGT motifs lacking CpGs were used. On the other hand, CpG ODNs and IFN inhibited this GM-CSF secretion. Selective cell type removal from hPBMC indicated that CD56+ cells were responsible for GM-CSF secretion and that plasmacytoid dendritic cells (PDCs) regulate this process. In addition, PyNTTTTGT ODNs inhibited the IFN secretion induced by CpG ODNs in PDCs by interference with the TLR9 signaling pathway. Since IFN is essential for CD56+ stimulation by CpG ODNs, there is a reciprocal interference of CpG and PyNTTTTGT ODNs when acting on this cell population. This suggests that these synthetic ODNs mimic different natural alarm signals for activation of the immune system.

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