A Recombinant Rabies Virus Encoding Two Copies of the Glycoprotein Gene Confers Protection in Dogs against a Virulent Challenge

Liu, Xiaohui; Yang, Yuxiang; Sun, Ziyong; Jing, Chen; Ai, Jun; Dun, C. van; Fu, Zhen F.; Niu, Xuefeng; Guo, Xingchen

doi:10.1371/journal.pone.0087105

Cited by 38 publications

(44 citation statements)

References 38 publications

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“…Cistrons encoding the structural envelope proteins, which are the principal targets of protective neutralizing immunity, are located in the second-or third-to-last positions of the genomes of paramyxoviruses, resulting in relatively low expression levels (16). Envelope protein expression can be augmented by increasing the copy number of their coding cistrons and/or by moving these cistrons proximally within the viral genome (17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27). To develop an MV vaccine containing a greater immunogenic stimulus within the standard WHO-approved dosage, we constructed two recombinant MVs that express an additional copy of the hemagglutinin (H) protein in a membrane-bound or soluble form from the second position of a Moraten strain-equivalent genome, resulting in increased expression and incorporation or secretion of H while maintaining replicative fitness and stability.…”

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confidence: 99%

Generation of a More Immunogenic Measles Vaccine by Increasing Its Hemagglutinin Expression

Julik

Valle

2016

J Virol

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Imported measles virus (MV) outbreaks are maintained by poor vaccine responders and unvaccinated people. A convenient but more immunogenic vaccination strategy would enhance vaccine performance, contributing to measles eradication efforts. We report here the generation of alternative pediatric vaccines against MV with increased expression of the H protein in the background of the current MV vaccine strain. We generated two recombinants: MVvac2-H2, with increased full-length H expression resulting in a 3-fold increase in H incorporation into virions, and MVvac2-Hsol, vectoring a truncated, soluble form of the H protein that is secreted into the supernatants of infected cells. Replication fitness was conserved despite the duplication of the H cistron for both vectors. The modification to the envelope of MVvac2-H2 conferred upon this virus a measurable level of resistance to in vitro neutralization by MV polyclonal immune sera without altering its thermostability. Most interestingly, both recombinant MVs with enhanced H expression were significantly more immunogenic than their parental strain in outbred mice, while MVvac2-H2 additionally proved more immunogenic after a single, human-range dose in genetically modified MV-susceptible mice. IMPORTANCEMeasles incidence was reduced drastically following the introduction of attenuated vaccines, but progress toward the eradication of this virus has stalled, and MV still threatens unvaccinated populations. Due to the contributions of primary vaccine failures and too-young-to-be-vaccinated infants to this problem, more immunogenic measles vaccines are highly desirable. We generated two experimental MV vaccines based on a current vaccine's genome but with enriched production of the H protein, the main MV antigen in provoking immunity. One vaccine incorporated H at higher rates in the viral envelope, and the other secreted a soluble H protein from infected cells. The increased expression of H by these vectors improved neutralizing responses induced in two small-animal models of MV immunogenicity. The enhanced immunogenicity of these vectors, mainly from the MV that incorporates additional H, suggests their value as potential alternative pediatric MV vaccines. Despite the existence of an effective vaccine, measles virus (MV) infections remain an insidious threat to global health. After decades of reduction in measles-related mortality due to vaccination, this has stalled at between 110,000 and 120,000 deaths/year since 2012. Approximately 20 million people are infected by measles each year, with significant morbidity and up to 1% mortality (1). In 2014, the United States saw the highest number of annual measles cases since native transmission was declared locally eliminated in 2000 (2) and experienced a large multistate outbreak in the first months of 2015 (3).Protecting young infants against measles is an important goal to attain to improve the current MV vaccine (4). The highest fatality rates due to MV infection occur in infants Ͻ1 year of age (5). Ironically, incre...

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confidence: 99%

Generation of a More Immunogenic Measles Vaccine by Increasing Its Hemagglutinin Expression

Julik

Valle

2016

J Virol

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“…Interestingly, the addition of IFNγ to the GAS backbone makes GASγ significantly more attenuated in suckling mice compared to the GASGAS control virus. This finding is notable because attenuated RABVs containing two glycoprotein (G) genes are less pathogenic and more immunogenic than their single G counterparts owing to G protein overexpression (27, 28). Therefore, RABV-expressed IFNγ can attenuate the virus to a higher degree than overexpression of G protein alone.…”

Section: Discussionmentioning

confidence: 99%

“…Doses as much as 10 7 –10 9 ffu of live-attenuated virus have previously been used for successful PET (6, 34) while 10 5 ffu was effective here. These types of experiments often compare the efficacy of live-attenuated RABV to inactivated RABV vaccine as well (28, 34). We show that relatively low doses of IFNγ-expressing RABV, GASγ, used for pre- and post-exposure treatment are highly efficacious and better protect mice than the already established vaccine vector, GASGAS.…”

Section: Discussionmentioning

confidence: 99%

Pre- and post-exposure safety and efficacy of attenuated rabies virus vaccines are enhanced by their expression of IFNγ

2015

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Consistent with evidence of a strong correlation between interferon gamma (IFNγ) production and rabies virus (RABV) clearance from the CNS, we recently demonstrated that engineering a pathogenic RABV to express IFNγ highly attenuates the virus. Reasoning that IFNγ expression by RABV vaccines would enhance their safety and efficacy, we reverse-engineered two proven vaccine vectors, GAS and GASGAS, to express murine IFNγ. Mortality and morbidity were monitored during suckling mice infection, immunize/challenge experiments and mixed intracranial infections. We demonstrate that GASγ and GASγGAS are significantly attenuated in suckling mice compared to the GASGAS vaccine. GASγ better protects mice from lethal DRV4 RABV infection in both pre- and post-exposure experiments compared to GASGAS. Finally, GASγGAS reduces post-infection neurological sequelae, compared to control, during mixed intracranial infection with DRV4. These data show IFNγ expression by a vaccine vector can enhance its safety while increasing its efficacy as pre- and post-exposure treatment.

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“…A large number of the anti-rabies vaccines have been developed using different systems, including baculovirus and plants (1)(2)(3)(4)(5)(6)(7) . One of the major advantages of the baculovirus-insect cell expression system is the high yield of recombinant protein produced per liter of cell culture (8) .…”

Section: Introductionmentioning

confidence: 99%

Respuesta de IFN-ɤ e IL-4 en ratones inoculados con una proteína G recombinante del virus de la rabia

Rojas-Anaya¹,

Esquivel-Guadarrama

Escribano-Romero

et al. 2015

Rev. Mex. Cienc. Pecu.

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RESUMENEl objetivo de este estudio fue comparar el comportamiento de IFN- e IL-4 en ratones inoculados con proteína G recombinante del virus de la rabia, que se expresa en maíz transgénico o baculovirus. Para este propósito, grupos de ratones se inocularon de la siguiente manera: Grupo 1, vacuna contra el virus de la rabia inactivado vía im; Grupo 2, proteína G recombinante derivada de plantas por vía oral; Grupo 3, proteína G expresada en baculovirus vía im; Grupo 4, proteína G expresada en baculovirus por vía oral; Grupo 5, maíz no transformado por vía oral. Los niveles de IFN- e IL-4 y los anticuerpos específicos se evaluaron cada 15 días. El desafío se realizó a los 60 días post inoculación (pi). Los grupos 1 y 3 promovieron una mejor respuesta humoral. Por otro lado, los resultados mostraron que los mismos grupos mostraron los mejores niveles de IFN- en el día 10 pi; mientras que la IL-4 se detectó en el día 15 pi. Para el estudio de supervivencia, el 83 % de los ratones inmunizados con vacuna inactivada, maíz y los inoculados im con extractos de baculovirus sobrevivieron la infección viral. La proteína G de la rabia recombinante expresada en baculovirus promovió IFN- y los anticuerpos de una manera similar a la vacuna de rabia inactivada. A pesar de esto los ratones alimentados con maíz transgénico sobrevivieron al desafío en el mismo porcentaje que el grupo 3. PALABRAS CLAVE INTRODUCCIÓNUn gran número de las vacunas contra la rabia se han desarrollado utilizando diferentes sistemas, incluyendo baculovirus y plantas (1)(2)(3)(4)(5)(6)(7) . Una de las principales ventajas del sistema de expresión de células de insecto-baculovirus es el alto rendimiento de la proteína recombinante producida por litro de cultivo celular (8) . Aunque se ha informado de la expresión de la proteína G del virus de la rabia en diferentes sistemas vegetales (7,9) el desarrollo de una vacuna oral contra la rabia reduciendo el costo de producción y distribución sería muy útil, especialmente para los países en desarrollo, donde la enfermedad es endémica en humanos y animales domésticos. La glicoproteína es el antígeno principal del virus de la rabia, es una proteína transmembrana, que consiste en un dominio citoplásmico, un dominio transmembranal y un ectodominio expuesto como trimero. El ectodominio está involucrado en la inducción de anticuerpos neutralizantes y linfocitos T citotóxicos y cooperadores (10,11) . Muchos estudios han demostrado que los extractos crudos del antígeno recombinante purificado de los extractos puros de las plantas o la planta entera pueden inducir respuestas inmunes locales o sistémicas (1,7,12) . En la literatura existen pocos estudios que han evaluado el tipo de citocinas inducidas por las vacunas antirrábicas de nueva generación (13) .El objetivo de este estudio fue comparar la respuesta de IFN- e IL-4 en ratones inoculados con proteína G recombinante del virus de la rabia (rGpRV) que se expresó tanto en células de insecto infectadas con baculovirus como en maíz transgénico. Para este propósito, la...

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A Recombinant Rabies Virus Encoding Two Copies of the Glycoprotein Gene Confers Protection in Dogs against a Virulent Challenge

Cited by 38 publications

References 38 publications

Generation of a More Immunogenic Measles Vaccine by Increasing Its Hemagglutinin Expression

Generation of a More Immunogenic Measles Vaccine by Increasing Its Hemagglutinin Expression

Pre- and post-exposure safety and efficacy of attenuated rabies virus vaccines are enhanced by their expression of IFNγ

Respuesta de IFN-ɤ e IL-4 en ratones inoculados con una proteína G recombinante del virus de la rabia

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