RESUMEN

Virus-like particles are excellent inducers of the adaptive immune response of humans and are presently being used as scaffolds for the presentation of foreign peptides and antigens derived from infectious microorganisms for subunit vaccine development. The most common approaches for peptide and antigen presentation are translational fusions and chemical coupling, but some alternatives that seek to simplify the coupling process have been reported recently. In this work, an alternative platform for coupling full antigens to virus-like particles is presented. Heterodimerization motifs inserted in both Tobacco etch virus coat protein and green fluorescent protein directed the coupling process by simple mixing, and the obtained complexes were easily taken up by a macrophage cell line.

Asunto(s)

Presentación de Antígeno/inmunología , Antígenos , Potyvirus , Vacunas de Partículas Similares a Virus , Animales , Antígenos/química , Antígenos/inmunología , Ratones , Potyvirus/química , Potyvirus/inmunología , Células RAW 264.7 , Vacunas de Partículas Similares a Virus/química , Vacunas de Partículas Similares a Virus/inmunología

RESUMEN

Passion fruit woodiness disease (PWD), caused by cowpea aphid-borne mosaic virus (CABMV), produces socioeconomic problems in Brazil. The objectives of this study were to i) evaluate the temporal progression of PWD, ii) identify Passiflora genotypes with resistance to CABMV, and iii) detect virus infection in asymptomatic plants by reverse transcription quantitative polymerase chain reaction (RT-qPCR) in cases where standard RT-PCR detection failed. The experiment was conducted in a greenhouse using 128 genotypes belonging to 12 species and three hybrids (inter- and intraspecific) of Passiflora, evaluated at five time points after inoculation. Progression rates and disease severity were lower in P. cincinnata, P. gibertii, P. miersii, and P. mucronata than in P. edulis, P. alata, Passiflora sp., and hybrids. Of the genotypes tested, 20.31% were resistant, especially the accessions of P. suberosa, P. malacophylla, P. setacea, P. pohlii, and P. bahiensis, which remained asymptomatic throughout the experiment. The absence of symptoms does not imply immunity of plants to the virus, since RT-qPCR analysis confirmed infection by the virus in asymptomatic plants of P. cincinnata, P. gibertii, P. miersii, P. mucronata, P. setacea, P. malacophylla, and P. suberosa. Even after four inoculations, the virus was not detected by RT-qPCR in the upper leaves in plants of the species P. pohlii and P. bahiensis, indicating that these species are probably immune to CABMV.

Asunto(s)

Passiflora/inmunología , Enfermedades de las Plantas/inmunología , Potyvirus/inmunología , Brasil , Genotipo , Passiflora/clasificación , Passiflora/virología , Enfermedades de las Plantas/virología , Hojas de la Planta/virología , Potyvirus/genética , Potyvirus/aislamiento & purificación , Prevalencia , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Índice de Severidad de la Enfermedad

RESUMEN

Papaya ringspot virus (PRSV), a common potyvirus infecting papaya plants worldwide, can lead to either antagonism or synergism in mixed infections with Papaya mosaic virus (PapMV), a potexvirus. These two unrelated viruses produce antagonism or synergism depending on their order of infection in the plant. When PRSV is inoculated first or at the same time as PapMV, the viral interaction is synergistic. However, an antagonistic response is observed when PapMV is inoculated before PRSV. In the antagonistic condition, PRSV is deterred from the plant and its drastic effects are overcome. Here, we examine differences in gene expression by high-throughput RNA sequencing, focused on immune system pathways. We present the transcriptomic expression of single and mixed inoculations of PRSV and PapMV leading to synergism and antagonism. Upregulation of dominant and hormone-mediated resistance transcripts suggests that the innate immune system participates in synergism. In antagonism, in addition to innate immunity, upregulation of RNA interference-mediated resistance transcripts suggests that adaptive immunity is involved.

Asunto(s)

Carica/virología , Genes de Plantas , Enfermedades de las Plantas/virología , Inmunidad de la Planta , Potexvirus/inmunología , Potyvirus/inmunología , Antibiosis , Carica/genética , Regulación de la Expresión Génica de las Plantas , Interacciones Microbiota-Huesped/inmunología

RESUMEN

BACKGROUND: Assembly of recombinant capsid proteins into virus-like particles (VLPs) still represents an interesting challenge in virus-based nanotechnologies. The structure of VLPs has gained importance for the development and design of new adjuvants and antigen carriers. The potential of Tobacco etch virus capsid protein (TEV CP) as adjuvant has not been evaluated to date. FINDINGS: Two constructs for TEV CP expression in Escherichia coli were generated: a wild-type version (TEV-CP) and a C-terminal hexahistidine (His)-tagged version (His-TEV-CP). Although both versions were expressed in the soluble fraction of E. coli lysates, only His-TEV-CP self-assembled into micrometric flexuous filamentous VLPs. In addition, the His-tag enabled high yields and facilitated purification of TEV VLPs. These TEV VLPs elicited broader IgG2-specific antibody response against a novel porcine reproductive and respiratory syndrome virus (PRRSV) protein when compared to the potent IgG1 response induced by the protein alone. CONCLUSIONS: His-TEV CP was purified by immobilized metal affinity chromatography and assembled into VLPs, some of them reaching 2-µm length. TEV VLPs administered along with PRRSV chimeric protein changed the IgG2/IgG1 ratio against the chimeric protein, suggesting that TEV CP can modulate the immune response against a soluble antigen.

Asunto(s)

Adyuvantes Inmunológicos/administración & dosificación , Anticuerpos Antivirales/sangre , Proteínas de la Cápside/administración & dosificación , Virus del Síndrome Respiratorio y Reproductivo Porcino/inmunología , Potyvirus/inmunología , Vacunas Virales/inmunología , Virosomas/administración & dosificación , Citoesqueleto de Actina/metabolismo , Adyuvantes Inmunológicos/metabolismo , Proteínas de la Cápside/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Expresión Génica , Inmunoglobulina G/sangre , Multimerización de Proteína , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/metabolismo , Virosomas/metabolismo

RESUMEN

Solanum tuberosum ssp. tuberosum (cv. Spunta) was transformed with a chimeric transgene containing the Potato virus Y (PVY) coat protein (CP) sequence. Screening for PVY resistance under greenhouse conditions yielded over 100 independent candidate lines. Successive field testing of selected lines allowed the identification of two genetically stable PVY-resistant lines, SY230 and SY233, which were further evaluated in field trials at different potato-producing regions in Argentina. In total, more than 2,000 individuals from each line were tested along a 6-year period. While no or negligible PVY infection was observed in the transgenic lines, infection rates of control plants were consistently high and reached levels of up to 70-80%. Parallel field studies were performed in virus-free environments to assess the agronomical performance of the selected lines. Tubers collected from these assays exhibited agronomical traits and biochemical compositions indistinguishable from those of the non-transformed Spunta cultivar. In addition, an interspecific out-crossing trial to determine the magnitude of possible natural gene flow between transgenic line SY233 and its wild relative Solanum chacoense was performed. This trial yielded negative results, suggesting an extremely low probability for such an event to occur.

Asunto(s)

Resistencia a la Enfermedad , Flujo Génico , Plantas Modificadas Genéticamente/genética , Potyvirus/patogenicidad , Solanum tuberosum/genética , Agrobacterium tumefaciens/genética , Agrobacterium tumefaciens/metabolismo , Argentina , Proteínas de la Cápside/genética , Proteínas de la Cápside/inmunología , Proteínas de la Cápside/metabolismo , Productos Agrícolas/genética , Productos Agrícolas/inmunología , Productos Agrícolas/virología , Cruzamientos Genéticos , Vectores Genéticos , Enfermedades de las Plantas/inmunología , Enfermedades de las Plantas/virología , Plantas Modificadas Genéticamente/inmunología , Plantas Modificadas Genéticamente/virología , Potyvirus/genética , Potyvirus/inmunología , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Alcaloides Solanáceos/análisis , Alcaloides Solanáceos/metabolismo , Solanum tuberosum/inmunología , Solanum tuberosum/virología , Transformación Genética , Transgenes

RESUMEN

Los problemas virales reducen los rendimientos y la calidad del tubérculo semilla en cultivos de papa de todo el mundo. Esta investigación se planteó con el fin de evaluar los niveles de incidencia de potyvirus en diez de las principales regiones cultivadoras de papa de los departamentos de Antioquia, Boyacá, Cundinamarca y Nariño (Colombia), y las características genotípicas del virus Y de la papa (Potato virus Y, PVY), seleccionado por ser el potyvirus más limitante de este cultivo. Para la evaluación de la incidencia se utilizaron pruebas de Elisa con anticuerpos que reconocen epítopes comunes a los potyvirus, mientras que las pruebas moleculares incluyeron el análisis filogenético de secuencias parciales del gen de la cápside viral de 33 aislamientos, así como la secuenciación de una porción de los extremos 5´ y 3´del genoma de dos cepas colombianas de este virus. Los resultados confirmaron la presencia de potyvirus en los cultivos de los cuatro departamentos evaluados, con una incidencia promedio del 72%, siendo este nivel superior al 56% en todas las zonas evaluadas. Los análisis moleculares del PVY, permitieron asociar las cepas colombianas estudiadas con las razas PVYN y la variante PVYNTN, esta última responsable de la enfermedad conocida en el mundo como PTNRD (Potato tuber necrotic ringspot disease).

---

Potato viruses are responsible for significant reductions in seed quality and crop yields around the world. In this study, we evaluate the levels of incidence of potyvirus in ten potato growing regions of Colombia from the provinces of Antioquia, Boyacá, Cundinamarca and Nariño. As PVY is the most limiting potyvirus in potato farming, a molecular characterization of Colombian PVY strains was also performed. Incidence was evaluated by ELISA using general potyvirus antibodies. Phylogenetic analysis were made on the partial sequence of the capsid gene from 33 isolates. A portion of the 5´ and 3' genome ends was obtained from two Colombian strains. Results confirmed the presence of potyvirus in the four provinces with an average incidence of 72%. The lowest incidence value was 56%. Molecular analysis clustered all Colombian isolates with strains PVYN and PVYNTN, the latter responsible for the disease known as PTNRD (Potato tuber necrotic ringspot disease).

Asunto(s)

Potyvirus/aislamiento & purificación , Potyvirus/enzimología , Potyvirus/fisiología , Potyvirus/genética , Potyvirus/inmunología , Potyvirus/metabolismo , Potyvirus/patogenicidad , Potyvirus/química , Potyvirus/ultraestructura , Cápside/fisiología , Cápside/inmunología , Cápside/microbiología , Cápside/parasitología , Cápside/patología , Cápside/química

RESUMEN

In this opinion article, we briefly review the status of crop biotechnology research-with emphasis on the development of GM crops-in Jamaica and Venezuela. We focus on the transgenic papayas developed for both countries, and examine the factors hindering not only the development and application of this biotechnological commodity for the improvement of agricultural productivity, but also on the challenges influencing societal acceptance of the technology.

Asunto(s)

Biotecnología/tendencias , Carica/genética , Enfermedades de las Plantas/prevención & control , Plantas Modificadas Genéticamente/genética , Biotecnología/economía , Carica/virología , Productos Agrícolas/genética , Productos Agrícolas/virología , Regulación Gubernamental , Jamaica , Enfermedades de las Plantas/virología , Inmunidad de la Planta/genética , Plantas Modificadas Genéticamente/virología , Potyvirus/inmunología , Potyvirus/patogenicidad , Opinión Pública , Venezuela

RESUMEN

Among diseases reported worldwidely for sweet potato (Ipomoea batatas (L) Lam) crop, one of the most frequent is the Sweet potato virus disease (SPVD), caused by sweet potato chlorotic stunt virus (SPCSV) and sweet potato feathery mottle virus (SPFMV) co-infection. In Argentina, there exists the sweet potato chlorotic dwarf (SPCD), a sweet potato disease caused by triple co-infection with SPCSV, SPFMV and sweet potato mild speckling virus (SPMSV). Both diseases cause a synergism between the potyviruses (SPFMV and SPMSV) and the crinivirus (SPCSV). Up to date, studies carried out on the interaction among these three viruses have not described their localization in the infected tissues. In single infections, virions of the crinivirus genus are limited to the phloem while potyviral virions are found in most tissues of the infected plant. The purpose of this work was to localize the heat shock protein 70 homolog (HSP70h), a movement protein for genus crinivirus, of an Argentinean SPCSV isolate in its single infection and in its double and triple co-infection with SPFMV and SPMSV. The localization was made by in situ hybridization (ISH) for electron microscopy (EM) on ultrathin sections of sweet potato cv. Morada INTA infected tissues. The results demonstrated that viral RNA coding HSP70h is restricted to phloem cells during crinivirus single infection, while it was detected outside the phloem in infections combined with the potyviruses involved in chlorotic dwarf disease.

Asunto(s)

Ipomoea batatas/ultraestructura , Ipomoea batatas/virología , Enfermedades de las Plantas/virología , Potyvirus/aislamiento & purificación , Potyvirus/ultraestructura , Secuencia de Aminoácidos , Argentina , Proteínas HSP70 de Choque Térmico/análisis , Proteínas HSP70 de Choque Térmico/genética , Ipomoea batatas/citología , Datos de Secuencia Molecular , Potyvirus/inmunología , Proteínas Virales/análisis , Proteínas Virales/genética

RESUMEN

Among diseases reported worldwidely for sweet potato (Ipomoea batatas (L) Lam) crop, one of the most frequent is the Sweet potato virus disease (SPVD), caused by sweet potato chlorotic stunt virus (SPCSV) and sweet potato feathery mottle virus (SPFMV) co-infection. In Argentina, there exists the sweet potato chlorotic dwarf (SPCD), a sweet potato disease caused by triple co-infection with SPCSV, SPFMV and sweet potato mild speckling virus (SPMSV). Both diseases cause a synergism between the potyviruses (SPFMV and SPMSV) and the crinivirus (SPCSV). Up to date, studies carried out on the interaction among these three viruses have not described their localization in the infected tissues. In single infections, virions of the crinivirus genus are limited to the phloem while potyviral virions are found in most tissues of the infected plant. The purpose of this work was to localize the heat shock protein 70 homolog (HSP70h), a movement protein for genus crinivirus, of an Argentinean SPCSV isolate in its single infection and in its double and triple co-infection with SPFMV and SPMSV. The localization was made by in situ hybridization (ISH) for electron microscopy (EM) on ultrathin sections of sweet potato cv. Morada INTA infected tissues. The results demonstrated that viral RNA coding HSP70h is restricted to phloem cells during crinivirus single infection, while it was detected outside the phloem in infections combined with the potyviruses involved in chlorotic dwarf disease.(AU)

Asunto(s)

Ipomoea batatas/citología , Ipomoea batatas/ultraestructura , Ipomoea batatas/virología , Proteínas HSP70 de Choque Térmico/análisis , Proteínas HSP70 de Choque Térmico/genética , Potyvirus/inmunología , Potyvirus/aislamiento & purificación , Potyvirus/ultraestructura , Secuencia de Aminoácidos , Argentina , Enfermedades de las Plantas/virología , Proteínas Virales/análisis , Proteínas Virales/genética

RESUMEN

Among diseases reported worldwidely for sweet potato (Ipomoea batatas (L) Lam) crop, one of the most frequent is the Sweet potato virus disease (SPVD), caused by sweet potato chlorotic stunt virus (SPCSV) and sweet potato feathery mottle virus (SPFMV) co-infection. In Argentina, there exists the sweet potato chlorotic dwarf (SPCD), a sweet potato disease caused by triple co-infection with SPCSV, SPFMV and sweet potato mild speckling virus (SPMSV). Both diseases cause a synergism between the potyviruses (SPFMV and SPMSV) and the crinivirus (SPCSV). Up to date, studies carried out on the interaction among these three viruses have not described their localization in the infected tissues. In single infections, virions of the crinivirus genus are limited to the phloem while potyviral virions are found in most tissues of the infected plant. The purpose of this work was to localize the heat shock protein 70 homolog (HSP70h), a movement protein for genus crinivirus, of an Argentinean SPCSV isolate in its single infection and in its double and triple co-infection with SPFMV and SPMSV. The localization was made by in situ hybridization (ISH) for electron microscopy (EM) on ultrathin sections of sweet potato cv. Morada INTA infected tissues. The results demonstrated that viral RNA coding HSP70h is restricted to phloem cells during crinivirus single infection, while it was detected outside the phloem in infections combined with the potyviruses involved in chlorotic dwarf disease.

Asunto(s)

Ipomoea batatas/citología , Ipomoea batatas/ultraestructura , Ipomoea batatas/virología , Potyvirus/inmunología , Potyvirus/aislamiento & purificación , Potyvirus/ultraestructura , /análisis , /genética , Secuencia de Aminoácidos , Argentina , Enfermedades de las Plantas/virología , Proteínas Virales/análisis , Proteínas Virales/genética

RESUMEN

Zucchini yellow mosaic virus (ZYMV, Potyvirus) emerged as an important pathogen of cucurbits within the last 20 years. Its origins and mechanisms for evolution and worldwide spread represent important questions to understand plant virus emergence. Sequence analysis on a 250 nucleotide fragment including the N-terminal part of the coat protein coding region, revealed one major group of strains, and some highly divergent isolates from distinct origins. Within the major group, three subsets of strains were defined without correlation with geographic origin, year of collection or biological properties. ZYMV was first observed in Martinique and Guadeloupe in 1992 and 1994, respectively. We studied the evolution of ZYMV variability on both islands in the few years following the putative virus introduction. In Martinique, molecular divergence remained low even after 6 years, suggesting a lack of new introductions. Interactions between strains resulted in a stability of the high biological variability, while the serological diversity decreased and molecular divergence remained low. In Guadeloupe, as in Martinique in 1993, serological variability was high shortly after virus introduction. While the first introduction in Guadeloupe was independent from Martinique, the 'Martinique' type was detected in 1998, suggesting further introductions, maybe through viruliferous aphids or imported plant material.

Asunto(s)

Potyvirus/fisiología , Secuencia de Aminoácidos , Anticuerpos Monoclonales/inmunología , Anticuerpos Antivirales/inmunología , Cápside/química , Cápside/inmunología , Cucurbita/virología , Evolución Molecular , Variación Genética , Datos de Secuencia Molecular , Filogenia , Enfermedades de las Plantas/virología , Potyvirus/clasificación , Potyvirus/genética , Potyvirus/inmunología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Serotipificación , Indias Occidentales

RESUMEN

Partial genomic sequences from an unknown garlic potyvirus and from an onion isolate of the onion yellow dwarf potyvirus (OYDV) were obtained. Comparison of the deduced amino acid sequences showed a similarity of 88% between the respective viral coat proteins. The garlic potyvirus coat protein was expressed in E. coli cells, purified, and subjected to Western blot analysis using antibodies raised against different garlic-infecting viruses. The expression protein was consistently recognised by anti-OYDV antibodies and did not react with antibodies specific for leek yellow stripe potyvirus (LYSV), garlic common latent carlavirus (GCLV) and shallot latent carlavirus (SLV). Besides, the garlic potyvirus coat protein was obtained as a fusion protein and used as antigen to produce polyclonal antibodies. These antibodies reacted with purified OYDV virions, but failed to recognise LYSV particles. In the light of this evidence the garlic potyvirus was identified as the garlic strain of OYDV.

Asunto(s)

Cápside/genética , Potyvirus/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Western Blotting , Cápside/inmunología , Cápside/metabolismo , Clonación Molecular , Escherichia coli/genética , Ajo/virología , Expresión Génica , Datos de Secuencia Molecular , Cebollas/virología , Plantas Medicinales , Potyvirus/inmunología , Potyvirus/metabolismo , Conejos , Proteínas Recombinantes de Fusión/inmunología , Recombinación Genética , Alineación de Secuencia , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido