69 research outputs found
Estudio de los requerimientos para la entrada del virus de la fiebre aftosa en cultivos celulares y caracterización del ácido valproico como compuesto antiviral
Tesis doctoral inédita, leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 08-11-201
Plasma Membrane Phosphatidylinositol 4,5 Bisphosphate Is Required for Internalization of Foot-and-Mouth Disease Virus and Vesicular Stomatitis Virus
Phosphatidylinositol-4,5-bisphosphate, PI(4,5)P 2, is a phospholipid which plays important roles in clathrin-mediated endocytosis. To investigate the possible role of this lipid on viral entry, two viruses important for animal health were selected: the enveloped vesicular stomatitis virus (VSV) - which uses a well characterized clathrin mediated endocytic route - and two different variants of the non-enveloped foot-and-mouth disease virus (FMDV) with distinct receptor specificities. The expression of a dominant negative dynamin, a PI(4,5)P 2 effector protein, inhibited the internalization and infection of VSV and both FMDV isolates. Depletion of PI(4,5)P 2 from plasma membrane using ionomycin or an inducible system, and inhibition of its de novo synthesis with 1-butanol revealed that VSV as well as FMDV C-S8c1, which uses integrins as receptor, displayed a high dependence on PI(4,5)P 2 for internalization. Expression of a kinase dead mutant (KD) of phosphatidylinositol-4-phosphate-5-kinase Iα (PIP5K-Iα), an enzyme responsible for PI(4,5)P 2 synthesis that regulates clathrin-dependent endocytosis, also impaired entry and infection of VSV and FMDV C-S8c1. Interestingly FMDV MARLS variant that uses receptors other than integrins for cell entry was less sensitive to PI(4,5)P 2 depletion, and was not inhibited by the expression of the KD PIP5K-Iα mutant suggesting the involvement of endocytic routes other than the clathrin-mediated on its entry. These results highlight the role of PI(4,5)P 2 and PIP5K-Iα on clathrin-mediated viral entry. © 2012 Vázquez-Calvo et al.BIO2008-0447-C03-01 and BIO2011-24351; Fundación Ramón ArecesPeer Reviewe
A single amino acid substitution in the capsid of foot-and-mouth disease virus can increase acid resistance
Foot-and-mouth disease virus (FMDV) particles lose infectivity due to their disassembly at pH values slightly below neutrality. This acid-dependent disassembly process is required for viral RNA release inside endosomes. To study the molecular determinants of viral resistance to acid-induced disassembly, six FMDV variants with increased resistance to acid inactivation were isolated. Infection by these mutants was more sensitive to drugs that raise the endosomal pH (NH4Cl and concanamycin A) than was infection by the parental C-S8c1 virus, confirming that the increase in acid resistance is related to a lower pH requirement for productive uncoating. Amino acid replacement N17D at the N terminus of VP1 capsid protein was found in all six mutants. This single substitution was shown to be responsible for increased acid resistance when introduced into an infectious FMDV clone. The increased resistance of this mutant against acid-induced inactivation was shown to be due to its increased resistance against capsid dissociation into pentameric subunits. Interestingly, the N17D mutation was located close to but not at the interpentamer interfaces. The mutants described here extend the panel of FMDV variants exhibiting different pH sensitivities and illustrate the adaptive flexibility of viral quasispecies to pH variations.Work at the F.S. laboratory was supported by grants from Ministerio de Ciencia e Innovación (MICINN) BIO2008-0447-C03-01 and CSD2006-0007; work at the M.G.M. laboratory was supported by grants from MICINN (BIO2009-10092) and Comunidad de Madrid (S-2009/MAT/1467). An institutional grant from Fundación Ramón Areces is also acknowledged.Peer Reviewe
Modification of the host cell lipid metabolism induced by hypolipidemic drugs targeting the acetyl coenzyme A carboxylase impairs West Nile virus replication
West Nile virus (WNV) is a neurotropic flavivirus transmitted by the bite of mosquitoes that causes meningitis and encephalitis in humans, horses, and birds. Several studies have highlighted that flavivirus infection is highly dependent on cellular lipids for virus replication and infectious particle biogenesis. The first steps of lipid synthesis involve the carboxylation of acetyl coenzyme A (acetyl-CoA) to malonyl-CoA that is catalyzed by the acetyl-CoA carboxylase (ACC). This makes ACC a key enzyme of lipid synthesis that is currently being evaluated as a therapeutic target for different disorders, including cancers, obesity, diabetes, and viral infections. We have analyzed the effect of the ACC inhibitor 5-(tetradecyloxy)-2-furoic acid (TOFA) on infection by WNV. Lipidomic analysis of TOFA-treated cells confirmed that this drug reduced the cellular content of multiple lipids, including those directly implicated in the flavivirus life cycle (glycerophospholipids, sphingolipids, and cholesterol). Treatment with TOFA significantly inhibited the multiplication of WNV in a dose-dependent manner. Further analysis of the antiviral effect of this drug showed that the inhibitory effect was related to a reduction of viral replication. Furthermore, treatment with another ACC inhibitor, 3,3,14,14-tetramethylhexadecanedioic acid (MEDICA 16), also inhibited WNV infection. Interestingly, TOFA and MEDICA 16 also reduced the multiplication of Usutu virus (USUV), a WNV-related flavivirus. These results point to the ACC as a druggable cellular target suitable for antiviral development against WNV and other flaviviruses.BIO2011-24351 (to F.S.), AGL2014-52395-C2-1-R (to F.S.), E-RTA2013-0013 (to J.-C.S. and F.S.), S2013/ABI-2906 (to J.-C.S. and F.S.), AGL2014-56518-JIN (to M.A.M.-A.), and CTQ2014-54743-R (to J.C.). Work at CBMSO was also supported by Fundación Ramón Areces.Peer Reviewe
Estudio de la viabilidad de la integración de un Sistema de Posicionamiento Óptico en el entorno de la radioterapia intraoperatoria
Actas de: XXIX Congreso Anual de la Sociedad Espñaola de Ingeniería Biomédica (CASEIB 2011). Cáceres, 16-18 Noviembre 2011.La radioterapia intraoperatoria (RIO) es una técnica que combina cirugía y radioterapia, que se aplica en pacientes con tumores para los que se ha indicado su resección y con alto riesgo recidivante. El oncólogo radioterapeuta planifica esta intervención sobre una imagen TAC del paciente. Sin embargo, los datos del escenario real encontrado en la sala de tratamiento (posición y orientación del aplicador respecto del paciente y energía del haz) se deben recoger de forma manual para actualizar la planificación. Esta información es muy valiosa para la documentación y posterior seguimiento del procedimiento realizado. En este trabajo se evalúa la viabilidad de la integración de un sistema de posicionamiento óptico en el entorno RIO, y su precisión para localizar el aplicador sobre la imagen de planificación.Este trabajo ha sido financiado por el Minsiterio de Ciencia e Innovación (PI09/90568 IPT-3000000-2010-3, TEC2010-21619-C04-01), la Comunidad de Madrid (ARTEMIS S2009/DPI-1802) y fondos FEDER.Publicad
Dynamics of Neospora caninum-Associated Abortions in a Dairy Sheep Flock and Results of a Test-and-Cull Control Programme
[EN] Neospora caninum is an apicomplexan parasite that can cause abortions and perinatal mortality in sheep. Although ovine neosporosis has been described worldwide, there is a lack of information about the relationship between N. caninum serostatus and the reproductive performance. In this study, we described the infection dynamics in a dairy sheep flock with an abortion rate up to 25% and a N. caninum seroprevalence of 32%. Abortions were recorded in 36% and 9% of seropositive and seronegative sheep, respectively. Seropositive sheep were more likely to abort twice (OR = 4.44) or three or more times (OR = 10.13) than seronegative sheep. Endogenous transplacental transmission was the main route of transmission since 86% of seropositive sheep had seropositive offspring. Within dams that had any abortion, seropositive sheep were more likely than seronegative ones to have female descendants that aborted (OR = 8.12). The slight increase in seropositivity with the age, the low percentage of animals with postnatal seroconversion or with low avidity antibodies, and the seropositivity of one flock dog, indicated that horizontal transmission might have some relevance in this flock. A control programme based on selective culling of seropositive sheep and replacement with seronegative animals was effective in reducing the abortion rate to 7.2%SIThis study was funded by the Spanish Ministry of Science and Innovation (PID2019- 104713RB-C21). R.S.-S. was funded by the Community of Madrid, Spain (PLATESA2, S2018/BAA- 4370) and M.F.-E. by UCM-Santander/2017 predoctoral grants. L.M. Ortega-Mora and G. Alvarez- Garcia are part of the TOXOSOURCES consortium, supported by funding from the European Union’s Horizon 2020 Research and Innovation programme under grant agreement No 773830: One Health European Joint Programme
Clinical infections by herpesviruses in patients treated with valproic acid: A nested case-control study in the Spanish Primary Care Database, BIFAP
The objective of this study is to evaluate the risk of clinical infections by herpesviruses in
patients exposed to valproic acid (VPA).We performed a case-control study nested in a primary cohort
selected from the Spanish primary care population-based research database BIFAP (Base de datos para
la Investigación Farmacoepidemiológica en Atención Primaria) over the period 2001–2015. The events
of interest were those diseases caused by any herpesviruses known to infect humans. For each
case, up to 10 controls per case matched by age, gender, and calendar date were randomly selected.
A conditional logistic regression was used to compute adjusted odds ratios (OR) and their 95%
confidence intervals (95% CI). Current use of VPA was associated with a trend towards a reduced risk
of clinical infections by herpesviruses as compared with non-users (OR 0.84; CI 95% 0.7–1.0; p = 0.057).
Among current users, a trend to a decreased risk with treatment durations longer than 90 days was
also observed. The results show a trend to a reduced risk of clinical infection by herpesviruses in
patients exposed to VPA. These results are consistent with those in vitro studies showing that, in
cultured cells, VPA can inhibit the production of the infectious progeny of herpesviruses. This study
also shows the efficient use of electronic healthcare records for clinical exploratory research studie
Dynamics of Neospora caninum-Associated Abortions in a Dairy Sheep Flock and Results of a Test-and-Cull Control Programme
Neospora caninum is an apicomplexan parasite that can cause abortions and perinatal mortality in sheep. Although ovine neosporosis has been described worldwide, there is a lack of information about the relationship between N. caninum serostatus and the reproductive performance. In this study, we described the infection dynamics in a dairy sheep flock with an abortion rate up to 25% and a N. caninum seroprevalence of 32%. Abortions were recorded in 36% and 9% of seropositive and seronegative sheep, respectively. Seropositive sheep were more likely to abort twice (OR = 4.44) or three or more times (OR = 10.13) than seronegative sheep. Endogenous transplacental transmission was the main route of transmission since 86% of seropositive sheep had seropositive offspring. Within dams that had any abortion, seropositive sheep were more likely than seronegative ones to have female descendants that aborted (OR = 8.12). The slight increase in seropositivity with the age, the low percentage of animals with postnatal seroconversion or with low avidity antibodies, and the seropositivity of one flock dog, indicated that horizontal transmission might have some relevance in this flock. A control programme based on selective culling of seropositive sheep and replacement with seronegative animals was effective in reducing the abortion rate to 7.2%
Comprehensive description of clinical characteristics of a large systemic Lupus Erythematosus Cohort from the Spanish Rheumatology Society Lupus Registry (RELESSER) with emphasis on complete versus incomplete lupus differences
Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by multiple organ involvement and pronounced racial and ethnic heterogeneity. The aims of the present work were (1) to describe the cumulative clinical characteristics of those patients included in the Spanish Rheumatology Society SLE Registry (RELESSER), focusing on the differences between patients who fulfilled the 1997 ACR-SLE criteria versus those with less than 4 criteria (hereafter designated as incomplete SLE (iSLE)) and (2) to compare SLE patient characteristics with those documented in other multicentric SLE registries. RELESSER is a multicenter hospital-based registry, with a collection of data from a large, representative sample of adult patients with SLE (1997 ACR criteria) seen at Spanish rheumatology departments. The registry includes demographic data, comprehensive descriptions of clinical manifestations, as well as information about disease activity and severity, cumulative damage, comorbidities, treatments and mortality, using variables with highly standardized definitions. A total of 4.024 SLE patients (91% with ≥4 ACR criteria) were included. Ninety percent were women with a mean age at diagnosis of 35.4 years and a median duration of disease of 11.0 years. As expected, most SLE manifestations were more frequent in SLE patients than in iSLE ones and every one of the ACR criteria was also associated with SLE condition; this was particularly true of malar rash, oral ulcers and renal disorder. The analysis-adjusted by gender, age at diagnosis, and disease duration-revealed that higher disease activity, damage and SLE severity index are associated with SLE [OR: 1.14; 95% CI: 1.08-1.20 (P < 0.001); 1.29; 95% CI: 1.15-1.44 (P < 0.001); and 2.10; 95% CI: 1.83-2.42 (P < 0.001), respectively]. These results support the hypothesis that iSLE behaves as a relative stable and mild disease. SLE patients from the RELESSER register do not appear to differ substantially from other Caucasian populations and although activity [median SELENA-SLEDA: 2 (IQ: 0-4)], damage [median SLICC/ACR/DI: 1 (IQ: 0-2)], and severity [median KATZ index: 2 (IQ: 1-3)] scores were low, 1 of every 4 deaths was due to SLE activity. RELESSER represents the largest European SLE registry established to date, providing comprehensive, reliable and updated information on SLE in the southern European population
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