Tolerance to mutations in the foot-and-mouth disease virus integrin-binding RGD region is different in cultured cells and in vivo and depends on the capsid sequence context.

Engineered RNAs carrying substitutions in the integrin receptor-binding Arg-Gly-Asp (RGD) region of foot-and-mouth disease virus (FMDV) were constructed (aa 141-147 of VP1 capsid protein) and their infectivity was assayed in cultured cells and suckling mice. The effect of these changes was studied in the capsid proteins of two FMDVs, C-S8c1, which enters cells through integrins, and 213hs(-), a derivative highly adapted to cell culture whose ability to infect cells using the glycosaminoglycan heparan sulfate (HS) as receptor, acquired by multiple passage on BHK-21 cells, has been abolished. The capsid sequence context determined infectivity in cultured cells and directed the selection of additional replacements in structural proteins. Interestingly, a viral population derived from a C-S8c1/L144A mutant, carrying only three substitutions in the capsid, was able to expand tropism to wild-type (wt) and mutant (mt)glycosaminoglycan-deficient CHO cells. In contrast, the 213hs(-) capsid tolerated all substitutions analysed with no additional mutations, and the viruses recovered maintained the ability of the 213hs(-) parental virus to infect wt and mt CHO cells. Viruses derived from C-S8c1 with atypical RGD regions were virulent and transmissible for mice with no other changes in the capsid. Substitution of Asp143 for Ala in the C-S8c1 capsid eliminated infectivity in cultured cells and mice. Co-inoculation with a neutralizing monoclonal antibody directed against the type C FMDV RGD region abolished infectivity of C-S8c1 virus on suckling mice, suggesting that FMDV can infect mice using integrins. Sequence requirements imposed for viral entry in vitro and in vivo are discussed

Use of RNA Domains in the Viral Genome as Innate Immunity Inducers for Antiviral Strategies and Vaccine Improvement

This chapter will focus on the role of innate immunity induction on antiviral responses with an emphasis on nucleic acids as type-I interferon (IFN) inducers and their use as antiviral compounds and vaccine adjuvants. A general and up-to-date view of the different mechanisms operating in the host cell for sensing viral genomes will be given, as well as viral strategies counteracting this response through immune evasion or specifically targeted antagonism. Our own recent data describing the ability to induce IFN and mediate protection against viral infection in vivo of synthetic RNA transcripts enclosing structural domains present in the 5´- and 3´-terminal regions of the foot-and-mouth disease virus (FMDV) genome will be summarized and discussed in this context. New vaccine formulations including innate immunity inducers are being developed for improvement of current vaccines. The potential of exogenous nucleic acids as modulators of immune response outcomes and vaccine adjuvants will be reviewed and discussed. A schematic summary of the interrelated topics addressed in this chapter is shown in Figure 1. Additionally, a glossary of all the acronyms and abbreviations used in the text and figures is shown in Table 1Spanish Ministry of Science and InnovationPeer reviewe

Structural Stability of the PsbQ Protein of Higher Plant Photosystem II

We have characterized the stability and folding behavior of the isolated extrinsic PsbQ protein of photosystem II (PSII) from a higher plant, Spinacia oleracea, using intrinsic protein fluorescence emission and near- and far-UV circular dichroism (CD) spectroscopy in combination with differential scanning calorimetry (DSC). Experimental results reveal that both chemical denaturation using guanidine hydrochloride (GdnHCl) and thermal unfolding of PsbQ proceed as a two-state reversible process. The denaturation free-energy changes (GD) at 20 C extrapolated from GdnHCl (4.0 ± 0.6 kcal mol-1) or thermal unfolding (4.4 ± 0.8 kcal mol-1) are very close. Moreover, the far-UV CD spectra of the denatured PsbQ registered at 90 C in the absence and presence of 6.0 M GdnHCl superimpose, leading us to conclude that both denatured states of PsbQ are structurally and energetically similar. The thermal unfolding of PsbQ has been also characterized by CD and DSC over a wide pH range. The stability of PsbQ is at its maximum at pH comprised between 5 and 8, being wider than the optimal pH for oxygen evolution in the lumen of thylakoid membranes. In addition, no significant structural changes were detected in PsbQ between 50 and 55 C in the pH range of 3-8, suggesting that PsbQ behaves as a soluble and stable particle in the lumen when it detaches from PSII under physiological stress conditions such as high temperature (45-50 C) or low pH (<5.0). Sedimentation experiments showed that, in solution at 20 C, the PsbQ protein is a monomer with an elongated shape.Spanish Minitry of Science and Technology (PB1998-0480 and AGL2004-00045)This work was funded by the Spanish Ministry of Science and Technology (project references PB1998-0480 and AGL2003-0045). M.B. holds a fellowship from the Spanish Ministry of Science and Technology.Peer reviewe

Non-coding RNAs derived from the foot-and-mouth disease virus genome trigger broad antiviral activity against coronaviruses

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of a potentially severe respiratory disease, the coronavirus disease 2019 (COVID-19), an ongoing pandemic with limited therapeutic options. Here, we assessed the anti-coronavirus activity of synthetic RNAs mimicking specific domains in the non-coding regions of the foot-and-mouth disease virus (FMDV) genome (ncRNAs). These molecules are known to exert broad-spectrum antiviral activity in cell culture, mice and pigs effectively triggering the host innate immune response. The ncRNAs showed potent antiviral activity against SARS-CoV-2 after transfection in human intestinal Caco-2 and lung epithelium Calu-3 2B4 cells. When the in vivo efficacy of the FMDV ncRNAs was assessed in K18-hACE2 mice, administration of naked ncRNA before intranasal SARS-CoV-2 infection significantly decreased the viral load and the levels of pro-inflammatory cytokines in the lungs compared with untreated infected mice. The ncRNAs were also highly efficacious when assayed against common human HCoV-229E and porcine transmissible gastroenteritis virus (TGEV) in hepatocyte-derived Huh-7 and swine testis ST cells, respectively. These results are a proof of concept of the pan-coronavirus antiviral activity of the FMDV ncRNAs including human and animal divergent coronaviruses and potentially enhance our ability to fight future emerging variants

Estudio experimental de los efectos de la adición de manidipino versus amlodipino en el tratamiento de pacientes diabéticos con hipertensión y microalbuminuria

La nefropatía diabética en los pacientes hipertensos es un reto terapéutico. Estos pacientes habitualmente requieren una pauta antihipertensiva combinada, siendo los bloqueadores del sistema renina-angiotensina la base del tratamiento, y requiriendo habitualmente añadir otros antihipertensivos para conseguir los objetivos terapéuticos. Según los resultados de estudios como ASCOT y ACCOMPLISH los antagonistas del calcio serian la mejor opción ya que parecen aportar un beneficio extra en esta situación. Es importante, sin embargo, establecer cuál es el antagonista del calcio con mejor perfil terapéutico. El objetivo de este estudio fue comparar la eficacia y la tolerabilidad de la adición de 20 mg de Manidipino frente a 10 mg de Amlodipino al tratamiento de los pacientes diabéticos con hipertensión no controlada y microalbuminuria persistente a pesar del empleo a dosis plenas de un inhibidor de la enzima de conversión de la angiotensina o antagonista de los receptores de angiotensina II durante un mínimo de 6 meses. Además se efectuó un seguimiento de la excreción urinaria de albúmina tanto durante la fase activa como durante una fase de extensión adicional de 18 meses. Se analizaron además, la presión arterial, la frecuencia cardiaca, los efectos sobre el tono simpático, el cumplimiento del tratamiento, la incidencia de efectos secundarios y una análisis multivariante para valorar el peso relativo de cada factor sobre la variación de la albuminuria. Se realizó un análisis post-hoc de la evolución de las necesidades de insulina en los pacientes tratados con la misma (dosis de insulina recibidas por los pacientes durante el estudio) y la tasa de insulinización valorando de progresión hacia la insulinización en pacientes que inicialmente estaban tratados únicamente con ADO. La hipótesis de este trabajo es confirmar el valor adicional de Manidipino, más allá de la reducción de PA, en los pacientes con diabetes e hipertensión, con respecto a la reducción de microalbuminuria, la influencia sobre el tono adrenérgico y el control metabólico. Se pueden esperar unos resultados favorables pues se ha demostrado en estudios previos con Manidipino: reducción de la excreción de albúmina, mejoría de la sensibilidad insulínica y reducción del riesgo de edemas y de activación simpática. Se estableció como diana tensional 130/80 mmHg de acuerdo con las directrices vigentes para los pacientes diabéticos durante el diseño del estudio. Los resultados del estudio demostraron que tanto la adición de Amlodipino como la de Manidipino resultaron eficaces para mejorar el control tensional de los pacientes reduciendo la PA en un grado similar. Sin embargo, la adición de Manidipino, y no la de Amlodipino, produjo una notable reducción de la albuminuria, con independencia de la reducción media de la PAM obtenida. Esta diferencia se mantuvo sin modificaciones significativas durante la fase de extensión Se obtuvo un nivel de cumplimiento significativamente superior en el grupo de pacientes tratados con Manidipino La tolerabilidad analítica fue favorable para ambos tratamientos. La tolerabilidad clínica fue superior para Manidipino, con una incidencia significativamente inferior de efectos adversos, especialmente de edema maleolar. En el grupo tratado con Manidipino no se produjo activación del sistema nervioso simpático a diferencia de Amlodipino. Esta diferencia puede justificar también las diferencias encontradas en cuanto a reducción de presión de pulso, frecuencia cardiaca y reducción de la incidencia de edemas maleolares. En los pacientes inicialmente tratados solamente con antidiabéticos orales se observó una incidencia muy significativamente menor de fracaso secundario de estos fármacos en el grupo tratado con Manidipino. En los pacientes insulinizados se observó una reducción significativa de las necesidades de insulina en el grupo tratado con Manidipino, mientras que dichas necesidades aumentaron en el grupo tratado con Amlodipino.Diabetic nephropathy in hypertensive patients is a therapeutic challenge. These patients usually require a combined antihypertensive regime, based on renin-angiotensin system blockers, and the addition of other antihypertensive drugs in order to achieve therapeutic goals. According to the results of studies such as ACCOMPLISH and ASCOT, the calcium antagonists would be the best option as they seem to provide an extra benefit in this situation. It is important, however, to establish which the calcium antagonist with best therapeutic profile is. The aim of this study was to compare the efficacy and tolerability of adding 20 mg Manidipine versus 10 mg Amlodipine to the treatment of diabetic patients with uncontrolled hypertension and persistent microalbuminuria despite receiving full doses of angiotensin converting enzyme inhibitors or Angiotensin II receptor antagonist for at least 6 months. Urinary albumin excretion was monitored both during the active phase and during an additional extension phase of 18 months. Blood pressure, heart rate, sympathetic tone, compliance with treatment, and incidence of side effects were also studied. To assess the relative weight of each factor on the change in albuminuria a multivariate analyses was performed. Changes in insulin requirements in those patients receiving insulin from the beginning of the study, and the rate of insulinization in those patients who were initially treated only with oral hypoglycemic agents were also performed in a post-hoc analyses. The hypothesis of this study was the additional value of Manidipine beyond BP reduction in patients with diabetes and hypertension, regarding the reduction of microalbuminuria, the influence on the adrenergic tone and the improvement of metabolic control. Favorable results could be expected, as previous studies with Manidipine had shown: reduced excretion of albumin, improvement in insulin sensitivity, and reduction in the risk of oedema and sympathetic activation. A 130/80 mmHg blood pressure target was established, according to the guidelines for diabetic patients in force during the study design. The study results showed that both the addition of Amlodipine and Manidipine proved effective in improving blood pressure control in patients reducing BP to a similar degree. However, the addition of Manidipine, not Amlodipine, produced a remarkable reduction in albuminuria, regardless of the average reduction obtained in the MBP. This difference remained without significant modifications during the extension phase A significantly higher level of compliance was obtained in the group treated with Manidipine. Analytical tolerability was favorable for both treatments. Clinical tolerability was superior in the Manidipine arm, with a significantly lower incidence of adverse effects, especially ankle oedema. In the Manidipine treated group, unlike to the Amlodipine treated group, the sympathetic nervous system was not activated. This difference may also justify the differences in terms of reduced pulse pressure, heart rate and incidence of ankle oedema. In those patients initially treated only with oral hypoglycemic drugs, a significantly lower incidence of secondary drug failure requiring insulinization was observed in the Manidipine treated group. In already insulinized patients, significantly reduced insulin requirements were observed in the Manidipine treated group, whereas these requirements were increased in the Amlodipine treated group

El virus del mosaico común de la judía : caracterización biológica, serológica y molecular de aislados españoles

En este trabajo se ha realizado un estudio epidemiológico mediante prospecciones de campo en distintas regiones españolas, siendo el virus del mosaico común de la judía (bcmv) el mas frecuente infectando judía. Se ha caracterizado serologicamente sus aislados por elisa y biológicamente mediante inoculación de cultivares de p. Vulgaris con distintos genotipos de resistencia para el virus. En un avance molecular se ha clonado y secuenciado la region 3' del rna genomico viral de dos aislados de distinto serotipo, estableciéndose un marco evolutivo y taxonómico mediante comparaciones de secuencia y análisis filogenetico entre bcmv y otros potyvirus de leguminosas relacionados. Utilizando la información de secuencia disponible se ha desarrollado un método de detección de los aislados de bcmv mediante la reacción en cadena de la polimerasa (pcr) a partir de extractos de hoja y de semillas infectado

Molecular mechanisms of foot-and-mouth disease virus targeting the host antiviral response

Foot-and-mouth disease virus (FMDV) is the causative agent of an acute vesicular disease affecting pigs, cattle and other domestic, and wild animals worldwide. The aim of the host interferon (IFN) response is to limit viral replication and spread. Detection of the viral genome and products by specialized cellular sensors initiates a signaling cascade that leads to a rapid antiviral response involving the secretion of type I- and type III-IFNs and other antiviral cytokines with antiproliferative and immunomodulatory functions. During co-evolution with their hosts, viruses have acquired strategies to actively counteract host antiviral responses and the balance between innate response and viral antagonism may determine the outcome of disease and pathogenesis. FMDV proteases Lpro and 3C have been found to antagonize the host IFN response by a repertoire of mechanisms. Moreover, the putative role of other viral proteins in IFN antagonism is being recently unveiled, uncovering sophisticated immune evasion strategies different to those reported to date for other members of the Picornaviridae family. Here, we review the interplay between antiviral responses induced by FMDV infection and viral countermeasures to block them. Research on strategies used by viruses to modulate immunity will provide insights into the function of host pathways involved in defense against pathogens and will also lead to development of new therapeutic strategies to fight virus infections.Research at the authors' group is supported by grant AGL2014-58675 (MINECO). Additional support is provided by grant P2013/ABI-2906 (co-financed by Autonomous Community of Madrid and EC FEDER funds). We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI).Peer Reviewe

Uncovering targets of the Leader protease: Linking RNA

RNA viruses have developed specialized mechanisms to subvert host RNA-binding proteins (RBPs) favoring their own gene expression. The Leader (L) protein of foot-and-mouth disease virus, a member of the Picornaviridae family, is a papain-like cysteine protease that self-cleaves from the polyprotein. Early in infection, the L protease cleaves the translation initiation factors eIF4GI and eIF4GII, inducing the shutdown of cap-dependent translation. However, the cleavage sites on the viral polyprotein, eIF4GI, and eIF4GII differ in sequence, challenging the definition of a consensus site for L targets. Identification of Gemin5 and Daxx proteolytic products in infected cells unveiled a motif centered on the RKAR sequence. The RBP Gemin5 is a member of the survival of motor neurons complex, a ribosome interacting protein, and a translation downregulator. Likewise, the Fas-ligand Daxx is a multifunctional adaptor that plays key roles in transcription control, apoptosis, and innate immune antiviral response. Remarkably, the cleavage site on the RNA helicases MDA5 and LGP2, two relevant immune sensors of the retinoic acid-inducible gene-I (RIG-I)-like receptors family, resembles the L target site of Gemin5 and Daxx, and similar cleavage sites have been reported in ISG15 and TBK1, two proteins involved in type I interferon response and signaling pathway, respectively. In this review we dissect the features of the L cleavage sites in essential RBPs, eventually helping in the discovery of novel L targets. This article is categorized under: RNA in Disease and Development > RNA in Disease Translation > Translation Regulation.Consejería de Educación e Investigación, Grant/Award Numbers: B2017/BMD-3770, S2018/BAA-4370; Consejo Superior de Investigaciones Científicas, Grant/Award Number: 201820I019; Ministerio de Economia y Competitividad, Grant/Award Numbers: BFU2017-84492-R, AGL2014-5867

Uncovering targets of the Leader protease: Linking RNA-mediated pathways and antiviral defense

RNA viruses have developed specialized mechanisms to subvert host RNA-binding proteins (RBPs) favoring their own gene expression. The Leader (L) protein of foot-and-mouth disease virus, a member of the Picornaviridae family, is a papain-like cysteine protease that self-cleaves from the polyprotein. Early in infection, the L protease cleaves the translation initiation factors eIF4GI and eIF4GII, inducing the shutdown of cap-dependent translation. However, the cleavage sites on the viral polyprotein, eIF4GI, and eIF4GII differ in sequence, challenging the definition of a consensus site for L targets. Identification of Gemin5 and Daxx proteolytic products in infected cells unveiled a motif centered on the RKAR sequence. The RBP Gemin5 is a member of the survival of motor neurons complex, a ribosome interacting protein, and a translation downregulator. Likewise, the Fas-ligand Daxx is a multifunctional adaptor that plays key roles in transcription control, apoptosis, and innate immune antiviral response. Remarkably, the cleavage site on the RNA helicases MDA5 and LGP2, two relevant immune sensors of the retinoic acid-inducible gene-I (RIG-I)-like receptors family, resembles the L target site of Gemin5 and Daxx, and similar cleavage sites have been reported in ISG15 and TBK1, two proteins involved in type I interferon response and signaling pathway, respectively. In this review we dissect the features of the L cleavage sites in essential RBPs, eventually helping in the discovery of novel L targets. This article is categorized under: RNA in Disease and Development > RNA in Disease Translation > Translation Regulation.Consejería de Educación e Investigación, Grant/Award Numbers: B2017/BMD-3770, S2018/BAA-4370; Consejo Superior de Investigaciones Científicas, Grant/Award Number: 201820I019; Ministerio de Economia y Competitividad, Grant/Award Numbers: BFU2017-84492-R, AGL2014-5867