Actividad del interferón de tipo III contra el virus de la diarrea viral bovina
Bovine Viral Diarrhea Virus (BVDV) represents a major challenge at a productive level due to its endemic nature almost worldwide. BVDV infection is highly prevalent in Argentina,\ncausing economic losses for the dairy and livestock industry, mostly associated with reproductive problems. The disease...
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Facultad de Ciencias Veterinarias
2019
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| Acceso en línea: | http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=avaposgra&cl=CL1&d=HWA_2836 http://repositoriouba.sisbi.uba.ar/gsdl/collect/avaposgra/index/assoc/HWA_2836.dir/2836.PDF |
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I28-R145-HWA_2836 |
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dspace |
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Universidad de Buenos Aires |
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I-28 |
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R-145 |
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Repositorio Digital de la Universidad de Buenos Aires (UBA) |
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Español |
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spa |
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Interferón tipo III Virus de la diarrea viral bovina Antivirales Diarreas víricas Bovinos Interferón tipo III Virología |
| spellingShingle |
Interferón tipo III Virus de la diarrea viral bovina Antivirales Diarreas víricas Bovinos Interferón tipo III Virología Quintana, María Eugenia Actividad del interferón de tipo III contra el virus de la diarrea viral bovina |
| topic_facet |
Interferón tipo III Virus de la diarrea viral bovina Antivirales Diarreas víricas Bovinos Interferón tipo III Virología |
| description |
Bovine Viral Diarrhea Virus (BVDV) represents a major challenge at a productive level due to its endemic nature almost worldwide. BVDV infection is highly prevalent in Argentina,\ncausing economic losses for the dairy and livestock industry, mostly associated with reproductive problems. The disease caused by BVDV presents with a varied signology that can range from a subclinical course to acute hemorrhagic symptoms with usually fatal\noutcome. BVDV also causes immunosuppression that predisposes the infected animal to bacterial and parasitic infections.\nBVDV belongs to the Flaviviridae family, genus Pestivirus and is represented by 3\ngenotypes: VDVB-1, VDVB-2 and VDVB-3 or "HoBi-like virus". In turn, this agent can be classified according to its biotype in either cytopathic (CP) and non-cytopathic (NCP). A fundamental characteristic of VDVB is its ability to generate persistent infections. The birth\nof persistently infected animals (PI) occurs when the pregnant females become infected with\na NCP strain of the BVDV between days 30 and 150 of gestation. These individuals are not able to mount an immune response and eliminate large amounts of virus in all excretions\nand secretions. Currently, two main measures are proposed for the control of the disease: the detection and segregation of PI animals, and the subsequent vaccination of the entire\nnon-PI herd. The immunity conferred by vaccines that are on the market requires more than two weeks to develop and even more than one dose, moreover, its efficacy is non-optimal\nin the presence of maternal immunity. An additional disadvantage is that most of the commercial formulations do not provide\ncoverage against all virus strains circulating in the field. To complement the set of tools for VDVB control, antivirals are needed that can prevent viral\ndispersion, avoiding immunosuppression. Antivirals could be used in cases of outbreaks or\nas preventive before certain maneuvers such as transport, confinement, insemination, introduction of new animals, etc. In this work we propose the use of Interferons (IFNs) since\nthey are natural antivirals, of simple production and broad spectrum. In contrast to the\nadaptive immune response, the innate mechanisms of immune defense mediated by IFN are immediate and functional even in the early stages of intrauterine development. The\nadministration of IFNs as biotherapeutic agents is an effective measure for the treatment of several viral infections. Traditionally in therapies developed for humans, type I IFN (IFN-?)\nhas been used, which is currently being replaced due to its hematological toxicity, by type III IFN-?. IFN-?´s antitiviral effect is identical to IFN-? but localized in epithelia, without effect\non blood cells. The IFN-? family is conserved in cattle and treatment with IFN-?3 was successful in controlling oronasal infection with foot-and-mouth disease virus (FMDV). The therapeutic application or functionality of IFN-?3 to other viruses affecting livestock\nproduction has not been studied. This work proposes the following hypotheses: "Bovine IFN-?3 has antiviral activity against\nBVDV"; and "recombinant bovine IFN-?3 is a candidate to be used as a biotherapeutic agent\nagainst BVDV infections". To test these hypotheses, we have cloned and expressed the bovine INF-?3 and IFN-? in a recombinant system and evaluated their antiviral activity against different strains of BVDV both in vitro and in vivo to determine their potential use as\nbiotherapeutics.\nThe recombinant IFNs (rIFN) produced in supernatants of transfected HEK293T cells were quantified in active units determined on reference viruses and also using a reporter assay\nof activity based on Madin-Darby bovine kidney cells (MDBK) stably transfected with an MxA promoter upstream of the ORF for chloramphenicol acetyltransferase (CAT). To establish the sensitivity of VDVB field and reference strains to the rIFN, we developed a highthroughput technique applicable to CP and NPC strains. It is an in-cell ELISA that allows the\ndirect measurement of the infection by detecting a non-structural protein of the virus in cultured cell in microplates, without the need to harvest the cells. Using this assay, we\nestimated the 50% inhibitory concentration for each rINF using six strains of BVDV of\ndifferent biotype and genotype, verifying that the CP strains are more susceptible to both\nrIFN than the NCP and, particularly, the NCP type 2 strains were more sensitive to IFN-?. The activity of the rIFN was then evaluated in vivo, in a murine model of virulence developed\nin our laboratory, in which BALB/c mice infected with type 2 strains of the BVDV develop viremia at 4 or 7 days after infection. (dpi), according to the virulence of the strain. The high\nvirulence strain also suppressed the pro-inflammatory response in these animals. Treatment\nof mice with commercial murine rIFN showed that IFN-? would be more efficient in preventing infection while IFN-? would prevent viremia. Experiments of combined treatment with two doses of antiviral pre-and post-infection, combining the use of both rIFN, revealed\nthat the treatment with IFN-? before the infection followed then by IFN-? was effective in controlling the viremia in the mice, and that a pre- and post-infection treatment with IFN-? was equally protective. These results then indicated that rIFN-? was effective against BVDV\nin vivo, and that it would not be necessary to combine it with IFN-?. In order to evaluate the use of our rIFNs in cattle, we first established their safety on bovine blood cells (ex vivo). Both rIFNs were safe at the proposed usage doses, despite the fact that IFN-? caused apoptosis of immune cells when tested in very high doses. Safety studies\nwere carried out directly in the animals by assessing several hematological parameters postinoculation, with satisfactory results. We then performed a proof-of-concept experiment in\ncalves to evaluate the antiviral activity of rIFN-? against infection with an Argentinean field\nstrain (genotype 2, NCP) isolated in Buenos Aires province, which had been extensively characterized in our laboratory. Six BVDV free calves, which were infected with the above\nstrain, were selected for the study. Four of them were inoculated subcutaneously with two doses of rIFN-? two days before infection and two days after infection, while the other two\ncalves received placebo treatment (dilution medium). The untreated-infected animals developed clinical signs of respiratory disease between 2 and 4 days post-infection, viremia and viral excretion through nasal secretions were also detected. All the animals of the RIFN? treated group did not develop disease, none of them showed clinical signs. Three of them did not even present viremia or shedding.\nOnly one individual of the latter group presented viremia and shedding with lower values than those of the untreated group.\nWe have developed a recombinant IFN-?, a safe and effective antiviral, and demonstrated its potential use for the prevention and treatment of BVDV infections. We verified its antiviral effect against field and reference strains in vitro, as well as its innocuity and efficacy in cattle against an Argentinean field strain. We have established the BVDV mouse model of viremia which is very useful for studies with this virus in vivo. We developed a novel technique, consisting of an In-cell ELISA that uses a detector antibody against a conserved nonstructural protein that can be potentially applicable to accurately measure the infectivity of any viral strain, regardless of its ability to cause cell death in culture.\nThis work constitutes the first experimental evidence of the activity of bovine IFN-? as a biotherapeutic tool against BVDV in vivo, opening a new perspective focused on the use of\neconomic, biodegradable and safe biological antivirals to reduce the incidence of viral infections in animals in productive environment .\nThe application of this tool could indirectly impact the decrease in the use of antibiotics by decreasing the rate of bacterial infections that result from immune-suppressive viral infections. |
| author2 |
Capozzo, Alejandra Victoria |
| author_facet |
Capozzo, Alejandra Victoria Quintana, María Eugenia |
| format |
Tesis doctoral Tesis doctoral acceptedVersion |
| author |
Quintana, María Eugenia |
| author_sort |
Quintana, María Eugenia |
| title |
Actividad del interferón de tipo III contra el virus de la diarrea viral bovina |
| title_short |
Actividad del interferón de tipo III contra el virus de la diarrea viral bovina |
| title_full |
Actividad del interferón de tipo III contra el virus de la diarrea viral bovina |
| title_fullStr |
Actividad del interferón de tipo III contra el virus de la diarrea viral bovina |
| title_full_unstemmed |
Actividad del interferón de tipo III contra el virus de la diarrea viral bovina |
| title_sort |
actividad del interferón de tipo iii contra el virus de la diarrea viral bovina |
| publisher |
Facultad de Ciencias Veterinarias |
| publishDate |
2019 |
| url |
http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=avaposgra&cl=CL1&d=HWA_2836 http://repositoriouba.sisbi.uba.ar/gsdl/collect/avaposgra/index/assoc/HWA_2836.dir/2836.PDF |
| work_keys_str_mv |
AT quintanamariaeugenia actividaddelinterferondetipoiiicontraelvirusdeladiarreaviralbovina |
| _version_ |
1766017520035168256 |
| spelling |
I28-R145-HWA_28362019-09-25 Bovine Viral Diarrhea Virus (BVDV) represents a major challenge at a productive level due to its endemic nature almost worldwide. BVDV infection is highly prevalent in Argentina,\ncausing economic losses for the dairy and livestock industry, mostly associated with reproductive problems. The disease caused by BVDV presents with a varied signology that can range from a subclinical course to acute hemorrhagic symptoms with usually fatal\noutcome. BVDV also causes immunosuppression that predisposes the infected animal to bacterial and parasitic infections.\nBVDV belongs to the Flaviviridae family, genus Pestivirus and is represented by 3\ngenotypes: VDVB-1, VDVB-2 and VDVB-3 or "HoBi-like virus". In turn, this agent can be classified according to its biotype in either cytopathic (CP) and non-cytopathic (NCP). A fundamental characteristic of VDVB is its ability to generate persistent infections. The birth\nof persistently infected animals (PI) occurs when the pregnant females become infected with\na NCP strain of the BVDV between days 30 and 150 of gestation. These individuals are not able to mount an immune response and eliminate large amounts of virus in all excretions\nand secretions. Currently, two main measures are proposed for the control of the disease: the detection and segregation of PI animals, and the subsequent vaccination of the entire\nnon-PI herd. The immunity conferred by vaccines that are on the market requires more than two weeks to develop and even more than one dose, moreover, its efficacy is non-optimal\nin the presence of maternal immunity. An additional disadvantage is that most of the commercial formulations do not provide\ncoverage against all virus strains circulating in the field. To complement the set of tools for VDVB control, antivirals are needed that can prevent viral\ndispersion, avoiding immunosuppression. Antivirals could be used in cases of outbreaks or\nas preventive before certain maneuvers such as transport, confinement, insemination, introduction of new animals, etc. In this work we propose the use of Interferons (IFNs) since\nthey are natural antivirals, of simple production and broad spectrum. In contrast to the\nadaptive immune response, the innate mechanisms of immune defense mediated by IFN are immediate and functional even in the early stages of intrauterine development. The\nadministration of IFNs as biotherapeutic agents is an effective measure for the treatment of several viral infections. Traditionally in therapies developed for humans, type I IFN (IFN-?)\nhas been used, which is currently being replaced due to its hematological toxicity, by type III IFN-?. IFN-?´s antitiviral effect is identical to IFN-? but localized in epithelia, without effect\non blood cells. The IFN-? family is conserved in cattle and treatment with IFN-?3 was successful in controlling oronasal infection with foot-and-mouth disease virus (FMDV). The therapeutic application or functionality of IFN-?3 to other viruses affecting livestock\nproduction has not been studied. This work proposes the following hypotheses: "Bovine IFN-?3 has antiviral activity against\nBVDV"; and "recombinant bovine IFN-?3 is a candidate to be used as a biotherapeutic agent\nagainst BVDV infections". To test these hypotheses, we have cloned and expressed the bovine INF-?3 and IFN-? in a recombinant system and evaluated their antiviral activity against different strains of BVDV both in vitro and in vivo to determine their potential use as\nbiotherapeutics.\nThe recombinant IFNs (rIFN) produced in supernatants of transfected HEK293T cells were quantified in active units determined on reference viruses and also using a reporter assay\nof activity based on Madin-Darby bovine kidney cells (MDBK) stably transfected with an MxA promoter upstream of the ORF for chloramphenicol acetyltransferase (CAT). To establish the sensitivity of VDVB field and reference strains to the rIFN, we developed a highthroughput technique applicable to CP and NPC strains. It is an in-cell ELISA that allows the\ndirect measurement of the infection by detecting a non-structural protein of the virus in cultured cell in microplates, without the need to harvest the cells. Using this assay, we\nestimated the 50% inhibitory concentration for each rINF using six strains of BVDV of\ndifferent biotype and genotype, verifying that the CP strains are more susceptible to both\nrIFN than the NCP and, particularly, the NCP type 2 strains were more sensitive to IFN-?. The activity of the rIFN was then evaluated in vivo, in a murine model of virulence developed\nin our laboratory, in which BALB/c mice infected with type 2 strains of the BVDV develop viremia at 4 or 7 days after infection. (dpi), according to the virulence of the strain. The high\nvirulence strain also suppressed the pro-inflammatory response in these animals. Treatment\nof mice with commercial murine rIFN showed that IFN-? would be more efficient in preventing infection while IFN-? would prevent viremia. Experiments of combined treatment with two doses of antiviral pre-and post-infection, combining the use of both rIFN, revealed\nthat the treatment with IFN-? before the infection followed then by IFN-? was effective in controlling the viremia in the mice, and that a pre- and post-infection treatment with IFN-? was equally protective. These results then indicated that rIFN-? was effective against BVDV\nin vivo, and that it would not be necessary to combine it with IFN-?. In order to evaluate the use of our rIFNs in cattle, we first established their safety on bovine blood cells (ex vivo). Both rIFNs were safe at the proposed usage doses, despite the fact that IFN-? caused apoptosis of immune cells when tested in very high doses. Safety studies\nwere carried out directly in the animals by assessing several hematological parameters postinoculation, with satisfactory results. We then performed a proof-of-concept experiment in\ncalves to evaluate the antiviral activity of rIFN-? against infection with an Argentinean field\nstrain (genotype 2, NCP) isolated in Buenos Aires province, which had been extensively characterized in our laboratory. Six BVDV free calves, which were infected with the above\nstrain, were selected for the study. Four of them were inoculated subcutaneously with two doses of rIFN-? two days before infection and two days after infection, while the other two\ncalves received placebo treatment (dilution medium). The untreated-infected animals developed clinical signs of respiratory disease between 2 and 4 days post-infection, viremia and viral excretion through nasal secretions were also detected. All the animals of the RIFN? treated group did not develop disease, none of them showed clinical signs. Three of them did not even present viremia or shedding.\nOnly one individual of the latter group presented viremia and shedding with lower values than those of the untreated group.\nWe have developed a recombinant IFN-?, a safe and effective antiviral, and demonstrated its potential use for the prevention and treatment of BVDV infections. We verified its antiviral effect against field and reference strains in vitro, as well as its innocuity and efficacy in cattle against an Argentinean field strain. We have established the BVDV mouse model of viremia which is very useful for studies with this virus in vivo. We developed a novel technique, consisting of an In-cell ELISA that uses a detector antibody against a conserved nonstructural protein that can be potentially applicable to accurately measure the infectivity of any viral strain, regardless of its ability to cause cell death in culture.\nThis work constitutes the first experimental evidence of the activity of bovine IFN-? as a biotherapeutic tool against BVDV in vivo, opening a new perspective focused on the use of\neconomic, biodegradable and safe biological antivirals to reduce the incidence of viral infections in animals in productive environment .\nThe application of this tool could indirectly impact the decrease in the use of antibiotics by decreasing the rate of bacterial infections that result from immune-suppressive viral infections. Fil: Quintana, María Eugenia. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Buenos Aires, Argentina Facultad de Ciencias Veterinarias Capozzo, Alejandra Victoria Quintana, María Eugenia 2019-03-25 El Virus de la Diarrea Viral Bovina (VDVB) representa un importante desafío a nivel productivo debido a su carácter endémico a nivel mundial. La infección por el VDVB es altamente prevalente en la Argentina y provoca pérdidas económicas para la industria\nlechera y ganadera, asociadas mayormente a problemas reproductivos. La enfermedad provocada por el VDVB se presenta con una variada signología que puede ir desde un\ncurso subclínico a cuadros agudos hemorrágicos cuyo desenlace suele ser fatal. A esto se suma el efecto inmunosupresor del VDVB que predispone a infecciones bacterianas y\nparasitarias que pueden comprometer la vida del animal. El VDVB pertenece a la familia Flaviviridae, género Pestivirus y está representado por 3\ngenotipos: VDVB-1, VDVB-2 y VDVB-3 o ?Virus HoBi-like?. A su vez, este agente puede ser clasificado según su biotipo en citopático (CP) y no citopático (NCP). Una característica fundamental del VDVB es su capacidad de generar infecciones persistentes. El nacimiento\nde animales persistentemente infectados (PI) tiene lugar cuando las hembras preñadas se\ninfectan con una cepa NCP del VDVB entre los días 30 y 150 de gestación. Estos individuos no son capaces de montar una respuesta inmune y eliminan grandes cantidades de virus\nen todas las excreciones y secreciones. Actualmente se proponen dos medidas principales para el control de la enfermedad: la detección y eliminación de animales PI, y la posterior\nvacunación de todo el rodeo no PI. La primera medida es recibida con fuerte resistencia por parte de los productores. Por otro lado, la inmunidad que confieren las vacunas que se\nencuentran en el mercado requiere más de dos semanas para desarrollarse e incluso de más de una dosis, siendo dudosa su eficacia en presencia de inmunidad materna. A estos\ninconvenientes se suma que la mayoría de las formulaciones comerciales no brindan cobertura contra todas las cepas del virus que circulan en el campo.\nPara complementar el conjunto de herramientas para el control del VDVB se precisan antivirales que puedan prevenir la dispersión viral y evitar la inmunosupresión. Los\nantivirales podrían utilizarse en casos de brotes o como preventivo antes de ciertas\nmaniobras como el transporte, encierro, inseminaciones, introducción de nuevos animales, etc. En este trabajo proponemos el uso de Interferones (IFNs) ya que son antivirales\nnaturales, de sencilla producción y amplio espectro. En contraste con la respuesta inmune\nadaptativa, los mecanismos innatos de defensa inmune mediados por los IFNs son\ninmediatos, y resultan operativos incluso en las primeras etapas de desarrollo intrauterino.\nLa administración de IFNs como agentes bioterapéuticos es una medida efectiva para el\ntratamiento de varias infecciones virales. Tradicionalmente, en terapias desarrolladas para\nhumanos, se ha utilizado el IFN de tipo I (IFN-?). Este está siendo actualmente\nreemplazado, dada su toxicidad hematológica, por el IFN de tipo III (IFN-?). El efecto antiviral de esta última citoquina es idéntico al del IFN-? pero localizado en epitelios, principalmente en mucosas, sin efecto sobre las células sanguíneas. La familia del IFN-? se encuentra conservada en bovinos y el tratamiento con IFN-?3 ha mostrado ser eficaz en\ncontrolar la infección oronasal por el virus de la fiebre aftosa (VFA). No se ha estudiado la\naplicación terapéutica ni la funcionalidad del IFN-?3 contra otros virus que afectan la producción ganadera. Este trabajo plantea las siguientes hipótesis: ?El IFN-?3 bovino posee actividad antiviral\ncontra el VDVB?; y ?El IFN-?3 bovino recombinante es un candidato para ser utilizado como\nbioterapéutico en infecciones con el VDVB?. Para contrastar estas hipótesis, hemos clonado\ny expresado el IFN-?3 y el IFN-? bovinos en células de mamífero en cultivo y evaluamos su actividad antiviral frente a distintas cepas del VDVB tanto in vitro como in vivo para\ncomprobar su potencial uso como bioterapéutico en bovinos. Los IFN recombinantes (IFNr) producidos en sobrenadantes de células HEK293T\ntransfectadas fueron cuantificados en función a las unidades activas determinadas sobre\nun virus de referencia y utilizando un ensayo reportero de actividad basado en células de\nriñón bovino Madin-Darby T2 (MDBK-T2) transfectadas en forma estable con el promotor del gen Mx río arriba del ORF para la cloranfenicol acetiltransferasa (CAT). Para establecer\nla sensibilidad de cepas de campo y de referencia del VDVB a los IFNr, desarrollamos una\ntécnica de alto rendimiento aplicable a cepas CP y NPC. Se trata de un ELISA en células que permite la medición directa de la infección detectando una proteína no estructural del\nvirus en microplacas de cultivo celular, sin necesidad de cosechar las células. Utilizando este ensayo estimamos la concentración inhibitoria 50% para cada IFNr utilizando seis\ncepas de VDVB de diferente biotipo y genotipo, verificando que las cepas CP son más\nsusceptibles a ambos IFNr que las NCP y, particularmente, las cepas NCP de tipo 2 resultaron más sensibles al IFN-?.\nLa actividad de los IFNr fue evaluada luego in vivo, en un modelo murino de virulencia desarrollado en nuestro laboratorio, en el que ratones de la cepa BALB/c infectados con\ncepas del tipo 2 del VDVB desarrollan viremia a los 4 ó 7 días post infección (dpi), según la virulencia de la cepa. La cepa de alta virulencia suprimió además la respuesta proinflamatoria en estos animales. A juzgar por nuestros resultados, el tratamiento de los\nratones infectados con la cepa 98-124 (de baja virulencia) con IFNr murinos comerciales mostró que el IFN-? fue más eficiente en prevenir la infección mientras que el IFN-? evitó la viremia. Experimentos de tratamiento combinado con dos dosis de IFN pre y post infección, combinando el uso de ambos IFNs, reveló que el tratamiento con IFN-? antes de la infección\nseguido luego por IFN-? fue efectivo en controlar la viremia en los ratones. Además, el tratamiento pre y post-infección con IFN-? resultaba igualmente protector. La limitación de\nla replicación del VDVB se verificó además por la ausencia de TNF-? sistémico. Estos\nresultados entonces indicaron que el IFN-? resultaba efectivo contra el VDVB in vivo, y que\nno era necesario combinarlo con IFN-?. Para evaluar el uso de nuestros IFNr en bovinos establecimos primero la inocuidad de los\nmismos sobre células sanguíneas bovinas (ex vivo) donde ambos IFNs mostraron ser\nseguros a las dosis de uso propuestas, a pesar de que el IFN-? causó apoptosis de células inmunes bovinas a dosis altas. La determinación de la inocuidad posológica se realizó directamente en los animales mediante el control de parámetros hematológicos durante 14\ndías post-inoculación, revelando la ausencia de toxicidad con las diferentes dosis de IFN?r evaluadas. A partir de estos resultados se realizó una prueba de concepto en terneros\npara evaluar la factibilidad de la utilización de IFN-?r frente a la infección con una cepa de baja virulencia aislada en la provincia de Buenos Aires, del genotipo 2 y biotipo NCP,\nampliamente caracterizada en nuestro laboratorio. Se seleccionaron para el estudio 6 terneras libres del VDVB, que fueron infectadas con la cepa antedicha. Cuatro de ellas \nfueron inoculadas por vía sub-cutánea con dos dosis de IFN-?r dos días previos a la infección y dos días posteriores a la misma, mientras que las otras dos terneras recibieron\ntratamiento placebo (medio de dilución). Los animales infectados-no tratados desarrollaron\nenfermedad clínica con síntomas respiratorios entre los 2 a 4 días post-infección,\ndetectándose también viremia y excreción viral a través de secreciones nasales. Los animales del grupo tratado con IFN-?r no desarrollaron enfermedad ni presentaron signos\nclínicos. En tres de ellos no de detectó viremia ni excreción viral nasal. Un individuo de este\núltimo grupo presentó viremia y excreción viral pero con valores menores a los del grupo no tratado.\nHemos desarrollado un antiviral seguro y eficaz, IFN-?3 bovino recombinante, demostrando\nla factibilidad de su potencial utilización para la prevención y el tratamiento de las infecciones por el VDVB. Comprobamos el efecto antiviral del IFN-?r sobre cepas de campo\ny de referencia in vitro, como así también su inocuidad y eficacia en bovinos contra una\ncepa de campo Argentina del genotipo 2, biotipo NCP. Además, establecimos un modelo ratón de viremia por el VDVB, de gran utilidad para los estudios in vivo con este virus. Desarrollamos una técnica novedosa, que consiste en un ELISA en células que utiliza un\nanticuerpo detector contra una proteína conservada no estructural que puede ser\npotencialmente aplicable para medir con precisión la infectividad de cualquier cepa viral, independientemente de su capacidad de causar la muerte de células en cultivo.\nEste trabajo constituye la primera evidencia experimental del potencial bioterapéutico del\nIFN-? bovino contra el VDVB in vivo, abriendo una nueva perspectiva enfocada en el uso de antivirales biológicos económicos, biodegradables y seguros para reducir la incidencia de las infecciones virales en animales en ámbitos productivos. La aplicación de esta\nherramienta podría impactar indirectamente en la disminución del uso de antibióticos al\ndecrecer la tasa de infecciones bacterianas que devienen de las infecciones virales inmunosupresoras. application/pdf Interferón tipo III Virus de la diarrea viral bovina Antivirales spa Universidad de Buenos Aires. Facultad de Ciencias Veterinarias info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by-ncnd/2.5/ar/ Diarreas víricas Bovinos Interferón tipo III Virología Actividad del interferón de tipo III contra el virus de la diarrea viral bovina info:eu-repo/semantics/doctoralThesis info:ar-repo/semantics/tesis doctoral info:eu-repo/semantics/acceptedVersion http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=avaposgra&cl=CL1&d=HWA_2836 http://repositoriouba.sisbi.uba.ar/gsdl/collect/avaposgra/index/assoc/HWA_2836.dir/2836.PDF |