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Sample records for 4-based vaccine vector

  1. Cellular targeting of engineered heterologous antigens is a determinant factor for bovine herpesvirus 4-based vaccine vector development.

    PubMed

    Donofrio, Gaetano; Franceschi, Valentina; Capocefalo, Antonio; Taddei, Simone; Sartori, Chiara; Bonomini, Sabrina; Cavirani, Sandro; Cabassi, Clotilde S; Flammini, Cesidio F

    2009-11-01

    In a previous study, an apathogenic strain of bovine herpesvirus 4 (BoHV-4) cloned as a bacterial artificial chromosome and expressing a chimeric peptide (gE2/gD) as a secreted form was described. Recombinant virus-inoculated animals produced antibodies against bovine viral diarrhea virus (BVDV) gE2 and BoHV-1 gD. However, neutralizing antibodies were produced only against BVDV, not against BoHV-1. In the present work a recombinant BoHV-4 expressing a membrane-linked form of gE2/gD chimeric peptide was constructed, and inoculated rabbits produced serum-neutralizing antibodies against both BVDV and BoHV-1. Protein cell sorting and targeting are a very important issue when immunodominant antigens are engineered for recombinant virus vaccine development.

  2. Virus-Vectored Influenza Virus Vaccines

    PubMed Central

    Tripp, Ralph A.; Tompkins, S. Mark

    2014-01-01

    Despite the availability of an inactivated vaccine that has been licensed for >50 years, the influenza virus continues to cause morbidity and mortality worldwide. Constant evolution of circulating influenza virus strains and the emergence of new strains diminishes the effectiveness of annual vaccines that rely on a match with circulating influenza strains. Thus, there is a continued need for new, efficacious vaccines conferring cross-clade protection to avoid the need for biannual reformulation of seasonal influenza vaccines. Recombinant virus-vectored vaccines are an appealing alternative to classical inactivated vaccines because virus vectors enable native expression of influenza antigens, even from virulent influenza viruses, while expressed in the context of the vector that can improve immunogenicity. In addition, a vectored vaccine often enables delivery of the vaccine to sites of inductive immunity such as the respiratory tract enabling protection from influenza virus infection. Moreover, the ability to readily manipulate virus vectors to produce novel influenza vaccines may provide the quickest path toward a universal vaccine protecting against all influenza viruses. This review will discuss experimental virus-vectored vaccines for use in humans, comparing them to licensed vaccines and the hurdles faced for licensure of these next-generation influenza virus vaccines. PMID:25105278

  3. Chimpanzee Adenovirus Vector Ebola Vaccine.

    PubMed

    Ledgerwood, Julie E; DeZure, Adam D; Stanley, Daphne A; Coates, Emily E; Novik, Laura; Enama, Mary E; Berkowitz, Nina M; Hu, Zonghui; Joshi, Gyan; Ploquin, Aurélie; Sitar, Sandra; Gordon, Ingelise J; Plummer, Sarah A; Holman, LaSonji A; Hendel, Cynthia S; Yamshchikov, Galina; Roman, Francois; Nicosia, Alfredo; Colloca, Stefano; Cortese, Riccardo; Bailer, Robert T; Schwartz, Richard M; Roederer, Mario; Mascola, John R; Koup, Richard A; Sullivan, Nancy J; Graham, Barney S

    2017-03-09

    The unprecedented 2014 epidemic of Ebola virus disease (EVD) prompted an international response to accelerate the availability of a preventive vaccine. A replication-defective recombinant chimpanzee adenovirus type 3-vectored ebolavirus vaccine (cAd3-EBO), encoding the glycoprotein from Zaire and Sudan species, that offers protection in the nonhuman primate model, was rapidly advanced into phase 1 clinical evaluation. We conducted a phase 1, dose-escalation, open-label trial of cAd3-EBO. Twenty healthy adults, in sequentially enrolled groups of 10 each, received vaccination intramuscularly in doses of 2×10(10) particle units or 2×10(11) particle units. Primary and secondary end points related to safety and immunogenicity were assessed throughout the first 8 weeks after vaccination; in addition, longer-term vaccine durability was assessed at 48 weeks after vaccination. In this small study, no safety concerns were identified; however, transient fever developed within 1 day after vaccination in two participants who had received the 2×10(11) particle-unit dose. Glycoprotein-specific antibodies were induced in all 20 participants; the titers were of greater magnitude in the group that received the 2×10(11) particle-unit dose than in the group that received the 2×10(10) particle-unit dose (geometric mean titer against the Zaire antigen at week 4, 2037 vs. 331; P=0.001). Glycoprotein-specific T-cell responses were more frequent among those who received the 2×10(11) particle-unit dose than among those who received the 2×10(10) particle-unit dose, with a CD4 response in 10 of 10 participants versus 3 of 10 participants (P=0.004) and a CD8 response in 7 of 10 participants versus 2 of 10 participants (P=0.07) at week 4. Assessment of the durability of the antibody response showed that titers remained high at week 48, with the highest titers in those who received the 2×10(11) particle-unit dose. Reactogenicity and immune responses to cAd3-EBO vaccine were dose

  4. Tomorrow's vector vaccines for small ruminants.

    PubMed

    Kyriakis, C S

    2015-12-14

    Inactivated and attenuated vaccines have contributed to the control or even the eradication of significant animal pathogens. However, these traditional vaccine technologies have limitations and disadvantages. Inactivated vaccines lack efficacy against certain pathogens, while attenuated vaccines are not always as safe. New technology vaccines, namely DNA and recombinant viral vector vaccines, are being developed and tested against pathogens of small ruminants. These vaccines induce both humoral and cellular immune responses, are safe to manufacture and use and can be utilized in strategies for differentiation of infected from vaccinated animals. Although there are more strict regulatory requirements for the safety standards of these vaccines, once a vaccine platform is evaluated and established, effective vaccines can be rapidly produced and deployed in the field to prevent spread of emerging pathogens. The present article offers an introduction to these next generation technologies and examples of vaccines that have been tested against important diseases of sheep and goats.

  5. Evaluation of vaccine competition using HVT vector vaccines

    USDA-ARS?s Scientific Manuscript database

    Turkey herpesvirus (HVT) has been widely used as a vaccine for Marek’s disease (MD) since the 1970s. Because HVT is a safe vaccine that is poorly sensitive to interference from maternally derived antibodies, it has seen rising use as a vector for vaccines developed for protection against other comm...

  6. Permissive growth of human adenovirus type 4 vaccine strain-based vector in porcine cell lines.

    PubMed

    Gao, Dong-sheng; Li, Xiao-jing; Wan, Wen-yan; Li, Hong-jie; Wang, Xiao-xue; Yang, Xia; Li, Yong-tao; Chang, Hong-tao; Chen, Lu; Wang, Chuan-qing; Zhao, Jun

    2016-02-01

    In recent years, there has been considerable interest in using adenoviruses as live vectors to develop recombinant vaccines. Previous studies have demonstrated the safety and effectiveness of HIV/SIV and influenza vaccine candidates based on human adenovirus type 4 (Ad4) replication-competent vectors in rhesus macaque and human model. To explore the possibility of human Ad4 vaccine strain used as a vector in developing porcine vaccines, the growth properties of replication-competent human Ad4 vaccine strain recombinant encoding EGFP in different porcine cell lines were investigated. All tested cell lines are permissive for Ad4 vaccine strain vector with varied replication efficiency. Thus, human Ad4 based vectors would be promising supplement to adenovirus vectors as a delivery vehicle for recombinant vaccines in swine industry.

  7. Developments in Viral Vector-Based Vaccines

    PubMed Central

    Ura, Takehiro; Okuda, Kenji; Shimada, Masaru

    2014-01-01

    Viral vectors are promising tools for gene therapy and vaccines. Viral vector-based vaccines can enhance immunogenicity without an adjuvant and induce a robust cytotoxic T lymphocyte (CTL) response to eliminate virus-infected cells. During the last several decades, many types of viruses have been developed as vaccine vectors. Each has unique features and parental virus-related risks. In addition, genetically altered vectors have been developed to improve efficacy and safety, reduce administration dose, and enable large-scale manufacturing. To date, both successful and unsuccessful results have been reported in clinical trials. These trials provide important information on factors such as toxicity, administration dose tolerated, and optimized vaccination strategy. This review highlights major viral vectors that are the best candidates for clinical use. PMID:26344749

  8. Using multivalent adenoviral vectors for HIV vaccination.

    PubMed

    Gu, Linlin; Li, Zan C; Krendelchtchikov, Alexandre; Krendelchtchikova, Valentina; Wu, Hongju; Matthews, Qiana L

    2013-01-01

    Adenoviral vectors have been used for a variety of vaccine applications including cancer and infectious diseases. Traditionally, Ad-based vaccines are designed to express antigens through transgene expression of a given antigen. For effective vaccine development it is often necessary to express or present multiple antigens to the immune system to elicit an optimal vaccine as observed preclinically with mosaic/polyvalent HIV vaccines or malaria vaccines. Due to the wide flexibility of Ad vectors they are an ideal platform for expressing large amounts of antigen and/or polyvalent mosaic antigens. Ad vectors that display antigens on their capsid surface can elicit a robust humoral immune response, the "antigen capsid-incorporation" strategy. The adenoviral hexon protein has been utilized to display peptides in the majority of vaccine strategies involving capsid incorporation. Based on our abilities to manipulate hexon HVR2 and HVR5, we sought to manipulate HVR1 in the context of HIV antigen display for the first time ever. More importantly, peptide incorporation within HVR1 was utilized in combination with other HVRs, thus creating multivalent vectors. To date this is the first report where dual antigens are displayed within one Ad hexon particle. These vectors utilize HVR1 as an incorporation site for a seven amino acid region of the HIV glycoprotein 41, in combination with six Histidine incorporation within HVR2 or HVR5. Our study illustrates that these multivalent antigen vectors are viable and can present HIV antigen as well as His6 within one Ad virion particle. Furthermore, mouse immunizations with these vectors demonstrate that these vectors can elicit a HIV and His6 epitope-specific humoral immune response.

  9. Viral vector-based influenza vaccines

    PubMed Central

    de Vries, Rory D.; Rimmelzwaan, Guus F.

    2016-01-01

    ABSTRACT Antigenic drift of seasonal influenza viruses and the occasional introduction of influenza viruses of novel subtypes into the human population complicate the timely production of effective vaccines that antigenically match the virus strains that cause epidemic or pandemic outbreaks. The development of game-changing vaccines that induce broadly protective immunity against a wide variety of influenza viruses is an unmet need, in which recombinant viral vectors may provide. Use of viral vectors allows the delivery of any influenza virus antigen, or derivative thereof, to the immune system, resulting in the optimal induction of virus-specific B- and T-cell responses against this antigen of choice. This systematic review discusses results obtained with vectored influenza virus vaccines and advantages and disadvantages of the currently available viral vectors. PMID:27455345

  10. Vaccine Design: Replication-Defective Adenovirus Vectors.

    PubMed

    Zhou, Xiangyang; Xiang, Zhiquan; Ertl, Hildegund C J

    2016-01-01

    Replication-defective adenovirus (Ad) vectors were initially developed for gene transfer for correction of genetic diseases. Although Ad vectors achieved high levels of transgene product expression in a variety of target cells, expression of therapeutic proteins was found to be transient as vigorous T cell responses directed to components of the vector as well as the transgene product rapidly eliminate Ad vector-transduced cells. This opened the use of Ad vectors as vaccine carriers and by now a multitude of preclinical as well as clinical studies has shown that Ad vectors induce very potent and sustained transgene product-specific T and B cell responses. This chapter provides guidance on developing E1-deleted Ad vectors based on available viral molecular clones. Specifically, it describes methods for cloning, viral rescue and purification as well as quality control studies.

  11. Multivalent and Multipathogen Viral Vector Vaccines

    PubMed Central

    Borrow, Ray; Blanchard, Thomas J.

    2016-01-01

    ABSTRACT The presentation and delivery of antigens are crucial for inducing immunity and, desirably, lifelong protection. Recombinant viral vectors—proven safe and successful in veterinary vaccine applications—are ideal shuttles to deliver foreign proteins to induce an immune response with protective antibody levels by mimicking natural infection. Some examples of viral vectors are adenoviruses, measles virus, or poxviruses. The required attributes to qualify as a vaccine vector are as follows: stable insertion of coding sequences into the genome, induction of a protective immune response, a proven safety record, and the potential for large-scale production. The need to develop new vaccines for infectious diseases, increase vaccine accessibility, reduce health costs, and simplify overloaded immunization schedules has driven the idea to combine antigens from the same or various pathogens. To protect effectively, some vaccines require multiple antigens of one pathogen or different pathogen serotypes/serogroups in combination (multivalent or polyvalent vaccines). Future multivalent vaccine candidates are likely to be required for complex diseases like malaria and HIV. Other novel strategies propose an antigen combination of different pathogens to protect against several diseases at once (multidisease or multipathogen vaccines). PMID:27535837

  12. Replication-defective viruses as vaccines and vaccine vectors.

    PubMed

    Dudek, Tim; Knipe, David M

    2006-01-05

    The classical viral vaccine approaches using inactivated virus or live-attenuated virus have not been successful for some viruses, such as human immunodeficiency virus or herpes simplex virus. Therefore, new types of vaccines are needed to combat these infections. Replication-defective mutant viruses are defective for one or more functions that are essential for viral genome replication or synthesis and assembly of viral particles. These viruses are propagated in complementing cell lines expressing the missing gene product; however, in normal cells, they express viral gene products but do not replicate to form progeny virions. As vaccines, these mutant viruses have advantages of both classical types of viral vaccines in being as safe as inactivated virus but expressing viral antigens inside infected cells so that MHC class I and class II presentation can occur efficiently. Replication-defective viruses have served both as vaccines for the virus itself and as a vector for the expression of heterologous antigens. The potential advantages and disadvantages of these vaccines are discussed as well as contrasting them with single-cycle mutant virus vaccines and replicon/amplicon versions of vaccines. Replication-defective viruses have also served as important probes of the host immune response in helping to define the importance of the first round of infected cells in the host immune response, the mechanisms of activation of innate immune response, and the role of the complement pathway in humoral immune responses to viruses.

  13. Live bacterial vaccine vectors: An overview

    PubMed Central

    da Silva, Adilson José; Zangirolami, Teresa Cristina; Novo-Mansur, Maria Teresa Marques; Giordano, Roberto de Campos; Martins, Elizabeth Angélica Leme

    2014-01-01

    Genetically attenuated microorganisms, pathogens, and some commensal bacteria can be engineered to deliver recombinant heterologous antigens to stimulate the host immune system, while still offering good levels of safety. A key feature of these live vectors is their capacity to stimulate mucosal as well as humoral and/or cellular systemic immunity. This enables the use of different forms of vaccination to prevent pathogen colonization of mucosal tissues, the front door for many infectious agents. Furthermore, delivery of DNA vaccines and immune system stimulatory molecules, such as cytokines, can be achieved using these special carriers, whose adjuvant properties and, sometimes, invasive capacities enhance the immune response. More recently, the unique features and versatility of these vectors have also been exploited to develop anti-cancer vaccines, where tumor-associated antigens, cytokines, and DNA or RNA molecules are delivered. Different strategies and genetic tools are constantly being developed, increasing the antigenic potential of agents delivered by these systems, opening fresh perspectives for the deployment of vehicles for new purposes. Here we summarize the main characteristics of the different types of live bacterial vectors and discuss new applications of these delivery systems in the field of vaccinology. PMID:25763014

  14. Replicon RNA Viral Vectors as Vaccines

    PubMed Central

    Lundstrom, Kenneth

    2016-01-01

    Single-stranded RNA viruses of both positive and negative polarity have been used as vectors for vaccine development. In this context, alphaviruses, flaviviruses, measles virus and rhabdoviruses have been engineered for expression of surface protein genes and antigens. Administration of replicon RNA vectors has resulted in strong immune responses and generation of neutralizing antibodies in various animal models. Immunization of mice, chicken, pigs and primates with virus-like particles, naked RNA or layered DNA/RNA plasmids has provided protection against challenges with lethal doses of infectious agents and administered tumor cells. Both prophylactic and therapeutic efficacy has been achieved in cancer immunotherapy. Moreover, recombinant particles and replicon RNAs have been encapsulated by liposomes to improve delivery and targeting. Replicon RNA vectors have also been subjected to clinical trials. Overall, immunization with self-replicating RNA viruses provides high transient expression levels of antigens resulting in generation of neutralizing antibody responses and protection against lethal challenges under safe conditions. PMID:27827980

  15. Construction and Evaluation of Novel Rhesus Monkey Adenovirus Vaccine Vectors

    SciTech Connect

    Abbink, Peter; Maxfield, Lori F.; Ng'ang'a, David; Borducchi, Erica N.; Iampietro, M. Justin; Bricault, Christine A.; Teigler, Jeffrey E.; Blackmore, Stephen; Parenteau, Lily; Wagh, Kshitij; Handley, Scott A.; Zhao, Guoyan; Virgin, Herbert W.; Korber, Bette; Barouch, Dan H.

    2014-11-19

    Adenovirus vectors are widely used as vaccine candidates for a variety of pathogens, including HIV-1. To date, human and chimpanzee adenoviruses have been explored in detail as vaccine vectors. Furthermore, the phylogeny of human and chimpanzee adenoviruses is overlapping, and preexisting humoral and cellular immunity to both are exhibited in human populations worldwide. More distantly related adenoviruses may therefore offer advantages as vaccine vectors. We describe the primary isolation and vectorization of three novel adenoviruses from rhesus monkeys. The seroprevalence of these novel rhesus monkey adenovirus vectors was extremely low in sub-Saharan Africa human populations, and these vectors proved to have immunogenicity comparable to that of human and chimpanzee adenovirus vaccine vectors in mice. These rhesus monkey adenoviruses phylogenetically clustered with the poorly described adenovirus species G and robustly stimulated innate immune responses. These novel adenoviruses represent a new class of candidate vaccine vectors.

  16. Construction and Evaluation of Novel Rhesus Monkey Adenovirus Vaccine Vectors

    DOE PAGES

    Abbink, Peter; Maxfield, Lori F.; Ng'ang'a, David; ...

    2014-11-19

    Adenovirus vectors are widely used as vaccine candidates for a variety of pathogens, including HIV-1. To date, human and chimpanzee adenoviruses have been explored in detail as vaccine vectors. Furthermore, the phylogeny of human and chimpanzee adenoviruses is overlapping, and preexisting humoral and cellular immunity to both are exhibited in human populations worldwide. More distantly related adenoviruses may therefore offer advantages as vaccine vectors. We describe the primary isolation and vectorization of three novel adenoviruses from rhesus monkeys. The seroprevalence of these novel rhesus monkey adenovirus vectors was extremely low in sub-Saharan Africa human populations, and these vectors proved tomore » have immunogenicity comparable to that of human and chimpanzee adenovirus vaccine vectors in mice. These rhesus monkey adenoviruses phylogenetically clustered with the poorly described adenovirus species G and robustly stimulated innate immune responses. These novel adenoviruses represent a new class of candidate vaccine vectors.« less

  17. Parvovirus-like particles as vaccine vectors.

    PubMed

    Casal, J I; Rueda, P; Hurtado, A

    1999-09-01

    A wide array of systems have been developed to improve "classic" vaccines. The use of small polypeptides able to elicit potent antibody and cytotoxic responses seems to have enormous potential in the design of safer vaccines. While peptide coupling to large soluble proteins such as keyhole limpet hemocyanin is the current method of choice for eliciting antibody responses and insertion in live viruses for cytotoxic T-lymphocyte responses, alternative cheaper and/or safer methods will clearly be required in the future. Virus-like particles constitute very immunogenic molecules that allow for covalent coupling of the epitopes of interest in a simple way. In this article, we detail the methodology employed for the preparation of efficient virus vectors as delivery systems. We used parvovirus as the model for the design of new vaccine vectors. Recently parvovirus-like particles have been engineered to express foreign polypeptides in certain positions, resulting in the production of large quantities of highly immunogenic peptides, and to induce strong antibody, helper-T-cell, and cytotoxic T-lymphocyte responses. We discuss the different alternatives and the necessary steps to carry out this process, placing special emphasis on the flow of decisions that need to be made during the project. Copyright 1999 Academic Press.

  18. Adjuvants and vector systems for allergy vaccines.

    PubMed

    Moingeon, Philippe; Lombardi, Vincent; Saint-Lu, Nathalie; Tourdot, Sophie; Bodo, Véronique; Mascarell, Laurent

    2011-05-01

    Allergen-specific immunotherapy represents a curative treatment of type I allergies. Subcutaneous immunotherapy is conducted with allergens adsorbed on aluminum hydroxide or calcium phosphate particles, whereas sublingual immunotherapy relies on high doses of soluble allergen without any immunopotentiator. There is a potential benefit of adjuvants enhancing regulatory and Th1 CD4+T cell responses during specific immunotherapy. Molecules affecting dendritic cells favor the induction of T regulatory cell and Th1 responses and represent valid candidate adjuvants for allergy vaccines. Furthermore, the interest in viruslike particles and mucoadhesive particulate vector systems, which may better address the allergen(s) to tolerogenic antigen-presenting cells, is documented.

  19. Virally vectored vaccine delivery: medical needs, mechanisms, advantages and challenges.

    PubMed

    Pinschewer, Daniel D

    2017-08-14

    Vaccines represent one of the most successful chapters in the history of medicine. Over the past decades, the advent of recombinant cDNA technology has enabled the biomedical community to genetically engineer viruses for vaccine delivery purposes. As a starting point, this review evaluates the unmet medical needs, which drive scientists and industry to exploit such fundamentally new technology for human vaccination. The author discusses the molecular functioning, production and safety profile of replication-competent and -deficient viral vector systems, representing two fundamentally distinct classes of "genetic vaccines". Building upon this knowledge, he dissects the immunological mechanisms rendering immune responses to viral vectors qualitatively and quantitatively distinct from those elicited by non-live vaccination approaches. These mechanisms comprise (1) the vectors' innate immune recognition by the host cell, (2) potent priming of CD8+ cytotoxic T cells as a result of dendritic cell targeting and endogenous protein synthesis, (3) conformational antigen display for protective antibody induction as well as (4) prolonged availability of substantial quantities of antigen. Deduced from these features, preferential indications for virally vectored vaccines are discussed, taking into consideration specific medical needs as well as risk-benefit assessments of replicating vector systems. The limitations and challenges in virally vectored vaccination must also be given careful consideration. Pre-existing and vaccination-induced anti-vector immunity can interfere with vaccine immunogenicity and prime-boost vaccination, respectively. Additionally, the requirement for eukaryotic production systems imposes technological as well as regulatory hurdles. Existing strategies to overcome these challenges are outlined. With the recent licensure of the first virally vectored vaccine this review seems timely to herald the introduction of virally vectored vaccines into daily

  20. BoHV-4-Based Vector Single Heterologous Antigen Delivery Protects STAT1(-/-) Mice from Monkeypoxvirus Lethal Challenge

    PubMed Central

    Crump, Ryan W.; Doronin, Konstantin; Hembrador, Edguardo; Pompilio, Daniela; Tebaldi, Giulia; Estep, Ryan D.; Wong, Scott W.; Buller, Mark R.; Donofrio, Gaetano

    2015-01-01

    mortality and morbidity. This work demonstrated the efficacy of BoHV-4 based vectors and the use of BoHV-4 as a vaccine-vector platform. PMID:26086739

  1. Newcastle Disease Virus as a Vaccine Vector for Development of Human and Veterinary Vaccines

    PubMed Central

    Kim, Shin-Hee; Samal, Siba K.

    2016-01-01

    Viral vaccine vectors have shown to be effective in inducing a robust immune response against the vaccine antigen. Newcastle disease virus (NDV), an avian paramyxovirus, is a promising vaccine vector against human and veterinary pathogens. Avirulent NDV strains LaSota and B1 have long track records of safety and efficacy. Therefore, use of these strains as vaccine vectors is highly safe in avian and non-avian species. NDV replicates efficiently in the respiratory track of the host and induces strong local and systemic immune responses against the foreign antigen. As a vaccine vector, NDV can accommodate foreign sequences with a good degree of stability and as a RNA virus, there is limited possibility for recombination with host cell DNA. Using NDV as a vaccine vector in humans offers several advantages over other viral vaccine vectors. NDV is safe in humans due to host range restriction and there is no pre-existing antibody to NDV in the human population. NDV is antigenically distinct from common human pathogens. NDV replicates to high titer in a cell line acceptable for human vaccine development. Therefore, NDV is an attractive vaccine vector for human pathogens for which vaccines are currently not available. NDV is also an attractive vaccine vector for animal pathogens. PMID:27384578

  2. Newcastle Disease Virus as a Vaccine Vector for Development of Human and Veterinary Vaccines.

    PubMed

    Kim, Shin-Hee; Samal, Siba K

    2016-07-04

    Viral vaccine vectors have shown to be effective in inducing a robust immune response against the vaccine antigen. Newcastle disease virus (NDV), an avian paramyxovirus, is a promising vaccine vector against human and veterinary pathogens. Avirulent NDV strains LaSota and B1 have long track records of safety and efficacy. Therefore, use of these strains as vaccine vectors is highly safe in avian and non-avian species. NDV replicates efficiently in the respiratory track of the host and induces strong local and systemic immune responses against the foreign antigen. As a vaccine vector, NDV can accommodate foreign sequences with a good degree of stability and as a RNA virus, there is limited possibility for recombination with host cell DNA. Using NDV as a vaccine vector in humans offers several advantages over other viral vaccine vectors. NDV is safe in humans due to host range restriction and there is no pre-existing antibody to NDV in the human population. NDV is antigenically distinct from common human pathogens. NDV replicates to high titer in a cell line acceptable for human vaccine development. Therefore, NDV is an attractive vaccine vector for human pathogens for which vaccines are currently not available. NDV is also an attractive vaccine vector for animal pathogens.

  3. Vaxvec: The first web-based recombinant vaccine vector database and its data analysis.

    PubMed

    Deng, Shunzhou; Martin, Carly; Patil, Rasika; Zhu, Felix; Zhao, Bin; Xiang, Zuoshuang; He, Yongqun

    2015-11-27

    A recombinant vector vaccine uses an attenuated virus, bacterium, or parasite as the carrier to express a heterologous antigen(s). Many recombinant vaccine vectors and related vaccines have been developed and extensively investigated. To compare and better understand recombinant vectors and vaccines, we have generated Vaxvec (http://www.violinet.org/vaxvec), the first web-based database that stores various recombinant vaccine vectors and those experimentally verified vaccines that use these vectors. Vaxvec has now included 59 vaccine vectors that have been used in 196 recombinant vector vaccines against 66 pathogens and cancers. These vectors are classified to 41 viral vectors, 15 bacterial vectors, 1 parasitic vector, and 1 fungal vector. The most commonly used viral vaccine vectors are double-stranded DNA viruses, including herpesviruses, adenoviruses, and poxviruses. For example, Vaxvec includes 63 poxvirus-based recombinant vaccines for over 20 pathogens and cancers. Vaxvec collects 30 recombinant vector influenza vaccines that use 17 recombinant vectors and were experimentally tested in 7 animal models. In addition, over 60 protective antigens used in recombinant vector vaccines are annotated and analyzed. User-friendly web-interfaces are available for querying various data in Vaxvec. To support data exchange, the information of vaccine vectors, vaccines, and related information is stored in the Vaccine Ontology (VO). Vaxvec is a timely and vital source of vaccine vector database and facilitates efficient vaccine vector research and development.

  4. Vaxvec: The first web-based recombinant vaccine vector database and its data analysis

    PubMed Central

    Deng, Shunzhou; Martin, Carly; Patil, Rasika; Zhu, Felix; Zhao, Bin; Xiang, Zuoshuang; He, Yongqun

    2015-01-01

    A recombinant vector vaccine uses an attenuated virus, bacterium, or parasite as the carrier to express a heterologous antigen(s). Many recombinant vaccine vectors and related vaccines have been developed and extensively investigated. To compare and better understand recombinant vectors and vaccines, we have generated Vaxvec (http://www.violinet.org/vaxvec), the first web-based database that stores various recombinant vaccine vectors and those experimentally verified vaccines that use these vectors. Vaxvec has now included 59 vaccine vectors that have been used in 196 recombinant vector vaccines against 66 pathogens and cancers. These vectors are classified to 41 viral vectors, 15 bacterial vectors, 1 parasitic vector, and 1 fungal vector. The most commonly used viral vaccine vectors are double-stranded DNA viruses, including herpesviruses, adenoviruses, and poxviruses. For example, Vaxvec includes 63 poxvirus-based recombinant vaccines for over 20 pathogens and cancers. Vaxvec collects 30 recombinant vector influenza vaccines that use 17 recombinant vectors and were experimentally tested in 7 animal models. In addition, over 60 protective antigens used in recombinant vector vaccines are annotated and analyzed. User-friendly web-interfaces are available for querying various data in Vaxvec. To support data exchange, the information of vaccine vectors, vaccines, and related information is stored in the Vaccine Ontology (VO). Vaxvec is a timely and vital source of vaccine vector database and facilitates efficient vaccine vector research and development. PMID:26403370

  5. Development of Streptococcus pneumoniae Vaccines Using Live Vectors

    PubMed Central

    Wang, Shifeng; Curtiss, Roy

    2014-01-01

    Streptococcus pneumoniae still causes severe morbidity and mortality worldwide, especially in young children and the elderly. Much effort has been dedicated to developing protein-based universal vaccines to conquer the current shortcomings of capsular vaccines and capsular conjugate vaccines, such as serotype replacement, limited coverage and high costs. A recombinant live vector vaccine delivering protective antigens is a promising way to achieve this goal. In this review, we discuss the researches using live recombinant vaccines, mainly live attenuated Salmonella and lactic acid bacteria, to deliver pneumococcal antigens. We also discuss both the limitations and the future of these vaccines. PMID:25309747

  6. A role for vector control in dengue vaccine programs.

    PubMed

    Christofferson, Rebecca C; Mores, Christopher N

    2015-12-10

    Development and deployment of a successful dengue virus (DENV) vaccine has confounded research and pharmaceutical entities owing to the complex nature of DENV immunity and concerns over exacerbating the risk of DENV hemorrhagic fever (DHF) as a consequence of vaccination. Thus, consensus is growing that a combination of mitigation strategies will be needed for DENV to be successfully controlled, likely involving some form of vector control to enhance a vaccine program. We present here a deterministic compartmental model to illustrate that vector control may enhance vaccination campaigns with imperfect coverage and efficacy. Though we recognize the costs and challenges associated with continuous control programs, simultaneous application of vector control methods coincident with vaccine roll out can have a positive effect by further reducing the number of human cases. The success of such an integrative strategy is predicated on closing gaps in our understanding of the DENV transmission cycle in hyperedemic locations.

  7. Vector Design for Improved DNA Vaccine Efficacy, Safety and Production

    PubMed Central

    Williams, James A.

    2013-01-01

    DNA vaccination is a disruptive technology that offers the promise of a new rapidly deployed vaccination platform to treat human and animal disease with gene-based materials. Innovations such as electroporation, needle free jet delivery and lipid-based carriers increase transgene expression and immunogenicity through more effective gene delivery. This review summarizes complementary vector design innovations that, when combined with leading delivery platforms, further enhance DNA vaccine performance. These next generation vectors also address potential safety issues such as antibiotic selection, and increase plasmid manufacturing quality and yield in exemplary fermentation production processes. Application of optimized constructs in combination with improved delivery platforms tangibly improves the prospect of successful application of DNA vaccination as prophylactic vaccines for diverse human infectious disease targets or as therapeutic vaccines for cancer and allergy. PMID:26344110

  8. Leishmania vaccine development: exploiting the host-vector-parasite interface.

    PubMed

    Reed, S G; Coler, R N; Mondal, D; Kamhawi, S; Valenzuela, J G

    2016-01-01

    Visceral leishmaniasis (VL) is a disease transmitted by phlebotomine sand flies, fatal if untreated, and with no available human vaccine. In rodents, cellular immunity to Leishmania parasite proteins as well as salivary proteins of the sand fly is associated with protection, making them worthy targets for further exploration as vaccines. This review discusses the notion that a combination vaccine including Leishmania and vector salivary antigens may improve vaccine efficacy by targeting the parasite at its most vulnerable stage just after transmission. Furthermore, we put forward the notion that better modeling of natural transmission is needed to test efficacy of vaccines. For example, the fact that individuals living in endemic areas are exposed to sand fly bites and will mount an immune response to salivary proteins should be considered in pre-clinical and clinical evaluation of leishmaniasis vaccines. Nevertheless, despite remaining obstacles there is good reason to be optimistic that safe and effective vaccines against leishmaniasis can be developed.

  9. Progress on adenovirus-vectored universal influenza vaccines.

    PubMed

    Xiang, Kui; Ying, Guan; Yan, Zhou; Shanshan, Yan; Lei, Zhang; Hongjun, Li; Maosheng, Sun

    2015-01-01

    Influenza virus (IFV) infection causes serious health problems and heavy financial burdens each year worldwide. The classical inactivated influenza virus vaccine (IIVV) and live attenuated influenza vaccine (LAIV) must be updated regularly to match the new strains that evolve due to antigenic drift and antigenic shift. However, with the discovery of broadly neutralizing antibodies that recognize conserved antigens, and the CD8(+) T cell responses targeting viral internal proteins nucleoprotein (NP), matrix protein 1 (M1) and polymerase basic 1 (PB1), it is possible to develop a universal influenza vaccine based on the conserved hemagglutinin (HA) stem, NP, and matrix proteins. Recombinant adenovirus (rAd) is an ideal influenza vaccine vector because it has an ideal stability and safety profile, induces balanced humoral and cell-mediated immune responses due to activation of innate immunity, provides 'self-adjuvanting' activity, can mimic natural IFV infection, and confers seamless protection against mucosal pathogens. Moreover, this vector can be developed as a low-cost, rapid-response vaccine that can be quickly manufactured. Therefore, an adenovirus vector encoding conserved influenza antigens holds promise in the development of a universal influenza vaccine. This review will summarize the progress in adenovirus-vectored universal flu vaccines and discuss future novel approaches.

  10. Progress on adenovirus-vectored universal influenza vaccines

    PubMed Central

    Xiang, Kui; Ying, Guan; Yan, Zhou; Shanshan, Yan; Lei, Zhang; Hongjun, Li; Maosheng, Sun

    2015-01-01

    Influenza virus (IFV) infection causes serious health problems and heavy financial burdens each year worldwide. The classical inactivated influenza virus vaccine (IIVV) and live attenuated influenza vaccine (LAIV) must be updated regularly to match the new strains that evolve due to antigenic drift and antigenic shift. However, with the discovery of broadly neutralizing antibodies that recognize conserved antigens, and the CD8+ T cell responses targeting viral internal proteins nucleoprotein (NP), matrix protein 1 (M1) and polymerase basic 1 (PB1), it is possible to develop a universal influenza vaccine based on the conserved hemagglutinin (HA) stem, NP, and matrix proteins. Recombinant adenovirus (rAd) is an ideal influenza vaccine vector because it has an ideal stability and safety profile, induces balanced humoral and cell-mediated immune responses due to activation of innate immunity, provides ‘self-adjuvanting’ activity, can mimic natural IFV infection, and confers seamless protection against mucosal pathogens. Moreover, this vector can be developed as a low-cost, rapid-response vaccine that can be quickly manufactured. Therefore, an adenovirus vector encoding conserved influenza antigens holds promise in the development of a universal influenza vaccine. This review will summarize the progress in adenovirus-vectored universal flu vaccines and discuss future novel approaches. PMID:25876176

  11. Development of Recombinant HSV-Based Vaccine Vectors.

    PubMed

    Voellmy, Richard; Bloom, David C; Vilaboa, Nuria; Feller, Joyce

    2017-01-01

    Herpes simplex virus (HSV) causes significant morbidity on the human population through such clinical syndromes as cold sores, genital herpes, herpes stromal keratitis, and encephalitis. Attempts to generate efficacious vaccines to date have failed. We have recently described the use of a conditionally replication-competent HSV-1 vector to immunize mice against a lethal challenge of HSV-1. The unique feature of this vaccine vector is that its replication is tightly controlled and can only occur in the presence of local heat and the presence of a small molecule inducer (an antiprogestin). This gives it the safety advantage of a replication-defective vaccine vector as well as the advantage of a replication-competent vector in that it is able to stimulate innate and adaptive aspects of the immune response in a natural context that a replication-defective vector cannot. In this chapter we provide a brief overview of HSV vaccines followed by the methodology used to propagate and utilize replication-conditional HSV vectors as vaccines.

  12. Chikungunya Virus Vaccines: Viral Vector-Based Approaches.

    PubMed

    Ramsauer, Katrin; Tangy, Frédéric

    2016-12-15

    In 2013, a major chikungunya virus (CHIKV) epidemic reached the Americas. In the past 2 years, >1.7 million people have been infected. In light of the current epidemic, with millions of people in North and South America at risk, efforts to rapidly develop effective vaccines have increased. Here, we focus on CHIKV vaccines that use viral-vector technologies. This group of vaccine candidates shares an ability to potently induce humoral and cellular immune responses by use of highly attenuated and safe vaccine backbones. So far, well-described vectors such as modified vaccinia virus Ankara, complex adenovirus, vesicular stomatitis virus, alphavirus-based chimeras, and measles vaccine Schwarz strain (MV/Schw) have been described as potential vaccines. We summarize here the recent data on these experimental vaccines, with a focus on the preclinical and clinical activities on the MV/Schw-based candidate, which is the first CHIKV-vectored vaccine that has completed a clinical trial. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  13. Recombinant Salmonella Bacteria Vectoring HIV/AIDS Vaccines.

    PubMed

    Chin'ombe, Nyasha; Ruhanya, Vurayai

    2013-01-01

    HIV/AIDS is an important public health problem globally. An affordable, easy-to-deliver and protective HIV vaccine is therefore required to curb the pandemic from spreading further. Recombinant Salmonella bacteria can be harnessed to vector HIV antigens or DNA vaccines to the immune system for induction of specific protective immunity. These are capable of activating the innate, humoral and cellular immune responses at both mucosal and systemic compartments. Several studies have already demonstrated the utility of live recombinant Salmonella in delivering expressed foreign antigens as well as DNA vaccines to the host immune system. This review gives an overview of the studies in which recombinant Salmonella bacteria were used to vector HIV/AIDS antigens and DNA vaccines. Most of the recombinant Salmonella-based HIV/AIDS vaccines developed so far have only been tested in animals (mainly mice) and are yet to reach human trials.

  14. The influence of delivery vectors on HIV vaccine efficacy

    PubMed Central

    Ondondo, Beatrice O.

    2014-01-01

    Development of an effective HIV/AIDS vaccine remains a big challenge, largely due to the enormous HIV diversity which propels immune escape. Thus novel vaccine strategies are targeting multiple variants of conserved antibody and T cell epitopic regions which would incur a huge fitness cost to the virus in the event of mutational escape. Besides immunogen design, the delivery modality is critical for vaccine potency and efficacy, and should be carefully selected in order to not only maximize transgene expression, but to also enhance the immuno-stimulatory potential to activate innate and adaptive immune systems. To date, five HIV vaccine candidates have been evaluated for efficacy and protection from acquisition was only achieved in a small proportion of vaccinees in the RV144 study which used a canarypox vector for delivery. Conversely, in the STEP study (HVTN 502) where human adenovirus serotype 5 (Ad5) was used, strong immune responses were induced but vaccination was more associated with increased risk of HIV acquisition than protection in vaccinees with pre-existing Ad5 immunity. The possibility that pre-existing immunity to a highly promising delivery vector may alter the natural course of HIV to increase acquisition risk is quite worrisome and a huge setback for HIV vaccine development. Thus, HIV vaccine development efforts are now geared toward delivery platforms which attain superior immunogenicity while concurrently limiting potential catastrophic effects likely to arise from pre-existing immunity or vector-related immuno-modulation. However, it still remains unclear whether it is poor immunogenicity of HIV antigens or substandard immunological potency of the safer delivery vectors that has limited the success of HIV vaccines. This article discusses some of the promising delivery vectors to be harnessed for improved HIV vaccine efficacy. PMID:25202303

  15. An Adenoviral Vector Based Vaccine for Rhodococcus equi

    PubMed Central

    Giles, Carla; Ndi, Olasumbo; Barton, Mary D.; Vanniasinkam, Thiru

    2016-01-01

    Rhodococcus equi is a respiratory pathogen which primarily infects foals and is endemic on farms around the world with 50% mortality and 80% morbidity in affected foals. Unless detected early and treated appropriately the disease can be fatal. Currently, there is no vaccine available to prevent this disease. For decades researchers have endeavoured to develop an effective vaccine to no avail. In this study a novel human adenoviral vector vaccine for R. equi was developed and tested in the mouse model. This vaccine generated a strong antibody and cytokine response and clearance of R. equi was demonstrated following challenge. These results show that this vaccine could potentially be developed further for use as a vaccine to prevent R. equi disease in foals. PMID:27008624

  16. An Adenoviral Vector Based Vaccine for Rhodococcus equi.

    PubMed

    Giles, Carla; Ndi, Olasumbo; Barton, Mary D; Vanniasinkam, Thiru

    2016-01-01

    Rhodococcus equi is a respiratory pathogen which primarily infects foals and is endemic on farms around the world with 50% mortality and 80% morbidity in affected foals. Unless detected early and treated appropriately the disease can be fatal. Currently, there is no vaccine available to prevent this disease. For decades researchers have endeavoured to develop an effective vaccine to no avail. In this study a novel human adenoviral vector vaccine for R. equi was developed and tested in the mouse model. This vaccine generated a strong antibody and cytokine response and clearance of R. equi was demonstrated following challenge. These results show that this vaccine could potentially be developed further for use as a vaccine to prevent R. equi disease in foals.

  17. Poxvirus-vectored vaccines for rabies--a review.

    PubMed

    Weyer, Jacqueline; Rupprecht, Charles E; Nel, Louis H

    2009-11-27

    Oral rabies vaccination of target reservoir species has proved to be one of the pillars of successful rabies elimination programs. The use of live attenuated rabies virus vaccines has been extensive but several limitations hamper its future use. A recombinant vaccinia-rabies vaccine has also been successfully used for the oral vaccination of several species. Nevertheless, its lack of efficacy in certain important rabies reservoirs and concerns on the use of this potent live virus as vaccine carrier (vector) impair the expansion of its use for new target species and new areas. Several attenuated and host-restricted poxvirus alternatives, which supposedly offer enhanced safety, have been investigated. Once again, efficacy in certain target species and innocuity through the oral route remain major limitations of these vaccines. Alternative recombinant vaccines using adenovirus as an antigen delivery vector have been extensively investigated and may provide an important addition to the currently available oral rabies vaccine repertoire, but are not the primary subject of this review.

  18. Protection against infectious laryngotracheitis by in ovo vaccination with commercially available viral vector recombinant vaccines.

    PubMed

    Johnson, Deirdre I; Vagnozzi, Ariel; Dorea, Fernanda; Riblet, Sylva M; Mundt, Alice; Zavala, Guillermo; García, Maricarmen

    2010-12-01

    Infectious laryngotracheitis (ILT) is a highly contagious respiratory disease of chickens caused by infectious laryngotracheitis virus (ILTV). The disease is mainly controlled through biosecurity and by vaccination with live-attenuated vaccines. The chicken embryo origin (CEO) vaccines, although proven to be effective in experimental settings, have limited efficacy in controlling the disease in dense broiler production sites due to unrestricted use and poor mass vaccination coverage. These factors allowed CEO vaccines to regain virulence, causing long lasting and, consequently, severe outbreaks of the disease. A new generation of viral vector fowl poxvirus (FPV) and herpesvirus of turkey (HVT) vaccines carrying ILTV genes has been developed and such vaccines are commercially available. These vaccines are characterized by their lack of transmission, lack of ILTV-associated latent infections, and no reversion to virulence. HVT-vectored ILTV recombinant vaccines were originally approved for subcutaneous HVT or transcutaneous (pox) delivery. The increased incidence of ILTV outbreaks in broiler production sites encouraged the broiler industry to deliver the FPV-LT and HVT-LT recombinant vaccines in ovo. The objective of this study was to evaluate the protection induced by ILTV viral vector recombinant vaccines after in ovo application in 18-day-old commercial broiler embryos. The protection induced by recombinant ILTV vaccines was assessed by their ability to prevent clinical signs and mortality; to reduce challenge virus replication in the trachea; to prevent an increase in body temperature; and to prevent a decrease in body weight gain after challenge. In this study, both recombinant-vectored ILTV vaccines provided partial protection, thereby mitigating the disease, but did not reduce challenge virus loads in the trachea.

  19. Recombinant Mycobacterium bovis BCG as an HIV Vaccine Vector

    PubMed Central

    Chapman, Rosamund; Chege, Gerald; Shephard, Enid; Stutz, Helen; Williamson, Anna-Lise

    2011-01-01

    HIV-1 has resulted in a devastating AIDS pandemic. An effective HIV/AIDS vaccine that can be used to either, prevent HIV infection, control infection or prevent progression of the disease to AIDS is needed. In this review we discuss the use of Mycobacterium bovis BCG, the tuberculosis vaccine, as a vaccine vector for an HIV vaccine. Numerous features make BCG an attractive vehicle to deliver HIV antigens. It has a good safety profile, elicits long-lasting cellular immune responses and in addition manufacturing costs are affordable, a necessary consideration for developing countries. In this review we discuss the numerous factors that influence generation of a genetically stable recombinant BCG vaccine for HIV. PMID:20353397

  20. Vector transmission of leishmania abrogates vaccine-induced protective immunity.

    PubMed

    Peters, Nathan C; Kimblin, Nicola; Secundino, Nagila; Kamhawi, Shaden; Lawyer, Phillip; Sacks, David L

    2009-06-01

    Numerous experimental vaccines have been developed to protect against the cutaneous and visceral forms of leishmaniasis caused by infection with the obligate intracellular protozoan Leishmania, but a human vaccine still does not exist. Remarkably, the efficacy of anti-Leishmania vaccines has never been fully evaluated under experimental conditions following natural vector transmission by infected sand fly bite. The only immunization strategy known to protect humans against natural exposure is "leishmanization," in which viable L. major parasites are intentionally inoculated into a selected site in the skin. We employed mice with healed L. major infections to mimic leishmanization, and found tissue-seeking, cytokine-producing CD4+ T cells specific for Leishmania at the site of challenge by infected sand fly bite within 24 hours, and these mice were highly resistant to sand fly transmitted infection. In contrast, mice vaccinated with a killed vaccine comprised of autoclaved L. major antigen (ALM)+CpG oligodeoxynucleotides that protected against needle inoculation of parasites, showed delayed expression of protective immunity and failed to protect against infected sand fly challenge. Two-photon intra-vital microscopy and flow cytometric analysis revealed that sand fly, but not needle challenge, resulted in the maintenance of a localized neutrophilic response at the inoculation site, and removal of neutrophils following vector transmission led to increased parasite-specific immune responses and promoted the efficacy of the killed vaccine. These observations identify the critical immunological factors influencing vaccine efficacy following natural transmission of Leishmania.

  1. Viral vectors for avian influenza vaccines

    USDA-ARS?s Scientific Manuscript database

    Prior to 2003, vaccines against avian influenza (AI) had limited, individual country or regional use in poultry. In late 2003, H5N1 high pathogenicity (HP) AI spread from China to multiple Southeast Asian countries, and to Europe during 2005 and Africa during 2006, challenging governments and all p...

  2. Emerging cancer vaccines: the promise of genetic vectors.

    PubMed

    Aurisicchio, Luigi; Ciliberto, Gennaro

    2011-09-22

    Therapeutic vaccination against cancer is an important approach which, when combined with other therapies, can improve long-term control of cancer. In fact, the induction of adaptive immune responses against Tumor Associated Antigens (TAAs) as well as innate immunity are important factors for tumor stabilization/eradication. A variety of immunization technologies have been explored in last decades and are currently under active evaluation, such as cell-based, protein, peptide and heat-shock protein-based cancer vaccines. Genetic vaccines are emerging as promising methodologies to elicit immune responses against a wide variety of antigens, including TAAs. Amongst these, Adenovirus (Ad)-based vectors show excellent immunogenicity profile and have achieved immunological proof of concept in humans. In vivo electroporation of plasmid DNA (DNA-EP) is also a desirable vaccine technology for cancer vaccines, as it is repeatable several times, a parameter required for the long-term maintenance of anti-tumor immunity. Recent findings show that combinations of different modalities of immunization (heterologous prime/boost) are able to induce superior immune reactions as compared to single-modality vaccines. In this review, we will discuss the challenges and requirements of emerging cancer vaccines, particularly focusing on the genetic cancer vaccines currently under active development and the promise shown by Ad and DNA-EP heterologous prime-boost.

  3. Emerging Cancer Vaccines: The Promise of Genetic Vectors

    PubMed Central

    Aurisicchio, Luigi; Ciliberto, Gennaro

    2011-01-01

    Therapeutic vaccination against cancer is an important approach which, when combined with other therapies, can improve long-term control of cancer. In fact, the induction of adaptive immune responses against Tumor Associated Antigens (TAAs) as well as innate immunity are important factors for tumor stabilization/eradication. A variety of immunization technologies have been explored in last decades and are currently under active evaluation, such as cell-based, protein, peptide and heat-shock protein-based cancer vaccines. Genetic vaccines are emerging as promising methodologies to elicit immune responses against a wide variety of antigens, including TAAs. Amongst these, Adenovirus (Ad)-based vectors show excellent immunogenicity profile and have achieved immunological proof of concept in humans. In vivo electroporation of plasmid DNA (DNA-EP) is also a desirable vaccine technology for cancer vaccines, as it is repeatable several times, a parameter required for the long-term maintenance of anti-tumor immunity. Recent findings show that combinations of different modalities of immunization (heterologous prime/boost) are able to induce superior immune reactions as compared to single-modality vaccines. In this review, we will discuss the challenges and requirements of emerging cancer vaccines, particularly focusing on the genetic cancer vaccines currently under active development and the promise shown by Ad and DNA-EP heterologous prime-boost. PMID:24212974

  4. Transmission-Blocking Vaccines: Focus on Anti-Vector Vaccines against Tick-Borne Diseases.

    PubMed

    Neelakanta, Girish; Sultana, Hameeda

    2015-06-01

    Tick-borne diseases are a potential threat that account for significant morbidity and mortality in human population worldwide. Vaccines are not available to treat several of the tick-borne diseases. With the emergence and resurgence of several tick-borne diseases, emphasis on the development of transmission-blocking vaccines remains increasing. In this review, we provide a snap shot on some of the potential candidates for the development of anti-vector vaccines (a form of transmission-blocking vaccines) against wide range of hard and soft ticks that include Ixodes, Haemaphysalis, Dermacentor, Amblyomma, Rhipicephalus and Ornithodoros species.

  5. Aerosolized adenovirus-vectored vaccine as an alternative vaccine delivery method

    PubMed Central

    2011-01-01

    Conventional parenteral injection of vaccines is limited in its ability to induce locally-produced immune responses in the respiratory tract, and has logistical disadvantages in widespread vaccine administration. Recent studies suggest that intranasal delivery or vaccination in the respiratory tract with recombinant viral vectors can enhance immunogenicity and protection against respiratory diseases such as influenza and tuberculosis, and can offer more broad-based generalized protection by eliciting durable mucosal immune responses. Controlled aerosolization is a method to minimize vaccine particle size and ensure delivery to the lower respiratory tract. Here, we characterize the dynamics of aerosolization and show the effects of vaccine concentration on particle size, vector viability, and the actual delivered dose of an aerosolized adenoviral vector. In addition, we demonstrate that aerosol delivery of a recombinant adenoviral vaccine encoding H1N1 hemagglutinin is immunogenic and protects ferrets against homologous viral challenge. Overall, aerosol delivery offers comparable protection to intramuscular injection, and represents an attractive vaccine delivery method for broad-based immunization campaigns. PMID:22103776

  6. Avipoxviruses: infection biology and their use as vaccine vectors

    PubMed Central

    2011-01-01

    Avipoxviruses (APVs) belong to the Chordopoxvirinae subfamily of the Poxviridae family. APVs are distributed worldwide and cause disease in domestic, pet and wild birds of many species. APVs are transmitted by aerosols and biting insects, particularly mosquitoes and arthropods and are usually named after the bird species from which they were originally isolated. The virus species Fowlpox virus (FWPV) causes disease in poultry and associated mortality is usually low, but in flocks under stress (other diseases, high production) mortality can reach up to 50%. APVs are also major players in viral vaccine vector development for diseases in human and veterinary medicine. Abortive infection in mammalian cells (no production of progeny viruses) and their ability to accommodate multiple gene inserts are some of the characteristics that make APVs promising vaccine vectors. Although abortive infection in mammalian cells conceivably represents a major vaccine bio-safety advantage, molecular mechanisms restricting APVs to certain hosts are not yet fully understood. This review summarizes the current knowledge relating to APVs, including classification, morphogenesis, host-virus interactions, diagnostics and disease, and also highlights the use of APVs as recombinant vaccine vectors. PMID:21291547

  7. Alphavirus vectors: applications for DNA vaccine production and gene expression.

    PubMed

    Lundstrom, K

    2000-01-01

    Replication-deficient alphavirus vectors have been developed for efficient high-level transgene expression. The broad host range of alphaviruses has allowed infection of a wide variety of mammalian cell lines and primary cultures. Particularly, G protein-coupled receptors have been expressed at high levels and subjected to binding and functional studies. Expression in suspension cultures has greatly facilitated production of large quantities of recombinant proteins for structural studies. Injection of recombinant alphavirus vectors into rodent brain resulted in local reporter gene expression. Highly neuron-specific expression was obtained in hippocampal slice cultures in vivo. Additionally, preliminary studies in animal models suggest that alphavirus vectors can be attractive candidates for gene therapy applications. Traditionally alphavirus vectors, either attenuated strains or replication-deficient particles, have been used to elicit efficient immune responses in animals. Recently, the application of alphaviruses has been extended to naked nucleic acids. Injection of DNA as well as RNA vectors has demonstrated efficient antigen production. In many cases, protection against lethal challenges has been obtained after immunization with alphavirus particles or nucleic acid vectors. Alphavirus vectors can therefore be considered as potentially promising vectors for vaccine production.

  8. Combination recombinant simian or chimpanzee adenoviral vectors for vaccine development.

    PubMed

    Cheng, Cheng; Wang, Lingshu; Ko, Sung-Youl; Kong, Wing-Pui; Schmidt, Stephen D; Gall, Jason G D; Colloca, Stefano; Seder, Robert A; Mascola, John R; Nabel, Gary J

    2015-12-16

    Recombinant adenoviral vector (rAd)-based vaccines are currently being developed for several infectious diseases and cancer therapy, but pre-existing seroprevalence to such vectors may prevent their use in broad human populations. In this study, we investigated the potential of low seroprevalence non-human primate rAd vectors to stimulate cellular and humoral responses using HIV/SIV Env glycoprotein (gp) as the representative antigen. Mice were immunized with novel simian or chimpanzee rAd (rSAV or rChAd) vectors encoding HIV gp or SIV gp by single immunization or in heterologous prime/boost combinations (DNA/rAd; rAd/rAd; rAd/NYVAC or rAd/rLCM), and adaptive immunity was assessed. Among the rSAV and rChAd tested, rSAV16 or rChAd3 vector alone generated the most potent immune responses. The DNA/rSAV regimen also generated immune responses similar to the DNA/rAd5 regimen. rChAd63/rChAd3 and rChAd3 /NYVAC induced similar or even higher levels of CD4+ and CD8+ T-cell and IgG responses as compared to rAd28/rAd5, one of the most potent combinations of human rAds. The optimized vaccine regimen stimulated improved cellular immune responses and neutralizing antibodies against HIV compared to the DNA/rAd5 regimen. Based on these results, this type of novel rAd vector and its prime/boost combination regimens represent promising candidates for vaccine development.

  9. Challenges in manufacturing adenoviral vectors for global vaccine product deployment.

    PubMed

    Vellinga, Jort; Smith, J Patrick; Lipiec, Agnieszka; Majhen, Dragomira; Lemckert, Angelique; van Ooij, Mark; Ives, Paul; Yallop, Christopher; Custers, Jerome; Havenga, Menzo

    2014-04-01

    Abstract Once adenovirus vector-based vaccines are licensed for the prevention of important infectious diseases, manufacturing processes capable of reliably delivering large numbers of vaccine doses will be required. The highest burden of disease for many infectious pathogens under investigation occurs in resource-poor settings. Therefore, the price per dose will be an important determinant of success. This review describes common practices for manufacturing replication-incompetent adenovirus vectors at clinical scale. Recent innovations and strategies aimed at improving the cost-effectiveness of manufacturing and ensuring high-volume vaccine production and purification are described. Hereto, technologies to increase bioreactor yields are reviewed. In addition, the use of single-use perfusion bioreactors, modification of some purification steps to avoid the use of expensive endonucleases, and use of charged filters during anion exchange all have the potential to bring down the cost of goods and are thus described. Finally, processes for ensuring quality throughout the manufacturing process, methods for testing viral identity, and safety of master seeds through to the end vaccine product are described.

  10. Efficacy of HVT-IBD vector vaccine compared to attenuated live vaccine using in-ovo vaccination against a Korean very virulent IBDV in commercial broiler chickens.

    PubMed

    Roh, J-H; Kang, M; Wei, B; Yoon, R-H; Seo, H-S; Bahng, J-Y; Kwon, J-T; Cha, S-Y; Jang, H-K

    2016-05-01

    The production performance, efficacy, and safety of two types of vaccines for infectious bursal disease virus (IBDV) were compared with in-ovo vaccination of Cobb 500 broiler chickens for gross and microscopic examination of the bursa of Fabricius, bursa/body weight (b/B) ratio, flow cytometry, and serologic response to Newcastle disease virus (NDV) vaccination. One vaccine was a recombinant HVT-IBD vector vaccine (HVT as for herpesvirus of turkeys) and the other was an intermediate plus live IBDV vaccine. A significant difference was detected at 21 d. Eight of 10 chickens that received the IBDV live vaccine had severe bursal lesions and a relatively low b/B ratio of 0.95, and an inhibited NDV vaccine response. On the other hand, the HVT-IBD vector vaccine resulted in mild bursal lesions and a b/B ratio of 1.89. Therefore, the live vaccine had lower safety than that of the HVT-IBD vector vaccine. To determine the protective efficacy, chickens were intraocularly challenged at 24 d. Eight of 10 chickens in the IBDV live vaccination group showed gross and histological lesions characterized by hemorrhage, cyst formation, lymphocytic depletion, and a decreased b/B ratio. In contrast, the HVT-IBD vector vaccinated chickens showed mild gross and histological lesions in three of 10 chickens with a b/B ratio of 1.36, which was similar to that of the unchallenged controls. Vaccinated chickens showed a significant increase in IBDV antibody titers, regardless of the type of vaccine used. In addition, significantly better broiler flock performance was observed with the HVT-IBD vector vaccine compared to that of the live vaccine. Our results revealed that the HVT-IBD vector vaccine could be used as an alternative vaccine to increase efficacy, and to have an improved safety profile compared with the IBDV live vaccine using in-ovo vaccination against the Korean very virulent IBDV in commercial broiler chickens.

  11. Percutaneous Vaccination as an Effective Method of Delivery of MVA and MVA-Vectored Vaccines

    PubMed Central

    Meseda, Clement A.; Atukorale, Vajini; Kuhn, Jordan; Schmeisser, Falko; Weir, Jerry P.

    2016-01-01

    The robustness of immune responses to an antigen could be dictated by the route of vaccine inoculation. Traditional smallpox vaccines, essentially vaccinia virus strains, that were used in the eradication of smallpox were administered by percutaneous inoculation (skin scarification). The modified vaccinia virus Ankara is licensed as a smallpox vaccine in Europe and Canada and currently undergoing clinical development in the United States. MVA is also being investigated as a vector for the delivery of heterologous genes for prophylactic or therapeutic immunization. Since MVA is replication-deficient, MVA and MVA-vectored vaccines are often inoculated through the intramuscular, intradermal or subcutaneous routes. Vaccine inoculation via the intramuscular, intradermal or subcutaneous routes requires the use of injection needles, and an estimated 10 to 20% of the population of the United States has needle phobia. Following an observation in our laboratory that a replication-deficient recombinant vaccinia virus derived from the New York City Board of Health strain elicited protective immune responses in a mouse model upon inoculation by tail scarification, we investigated whether MVA and MVA recombinants can elicit protective responses following percutaneous administration in mouse models. Our data suggest that MVA administered by percutaneous inoculation, elicited vaccinia-specific antibody responses, and protected mice from lethal vaccinia virus challenge, at levels comparable to or better than subcutaneous or intramuscular inoculation. High titers of specific neutralizing antibodies were elicited in mice inoculated with a recombinant MVA expressing the herpes simplex type 2 glycoprotein D after scarification. Similarly, a recombinant MVA expressing the hemagglutinin of attenuated influenza virus rgA/Viet Nam/1203/2004 (H5N1) elicited protective immune responses when administered at low doses by scarification. Taken together, our data suggest that MVA and MVA-vectored

  12. Percutaneous Vaccination as an Effective Method of Delivery of MVA and MVA-Vectored Vaccines.

    PubMed

    Meseda, Clement A; Atukorale, Vajini; Kuhn, Jordan; Schmeisser, Falko; Weir, Jerry P

    2016-01-01

    The robustness of immune responses to an antigen could be dictated by the route of vaccine inoculation. Traditional smallpox vaccines, essentially vaccinia virus strains, that were used in the eradication of smallpox were administered by percutaneous inoculation (skin scarification). The modified vaccinia virus Ankara is licensed as a smallpox vaccine in Europe and Canada and currently undergoing clinical development in the United States. MVA is also being investigated as a vector for the delivery of heterologous genes for prophylactic or therapeutic immunization. Since MVA is replication-deficient, MVA and MVA-vectored vaccines are often inoculated through the intramuscular, intradermal or subcutaneous routes. Vaccine inoculation via the intramuscular, intradermal or subcutaneous routes requires the use of injection needles, and an estimated 10 to 20% of the population of the United States has needle phobia. Following an observation in our laboratory that a replication-deficient recombinant vaccinia virus derived from the New York City Board of Health strain elicited protective immune responses in a mouse model upon inoculation by tail scarification, we investigated whether MVA and MVA recombinants can elicit protective responses following percutaneous administration in mouse models. Our data suggest that MVA administered by percutaneous inoculation, elicited vaccinia-specific antibody responses, and protected mice from lethal vaccinia virus challenge, at levels comparable to or better than subcutaneous or intramuscular inoculation. High titers of specific neutralizing antibodies were elicited in mice inoculated with a recombinant MVA expressing the herpes simplex type 2 glycoprotein D after scarification. Similarly, a recombinant MVA expressing the hemagglutinin of attenuated influenza virus rgA/Viet Nam/1203/2004 (H5N1) elicited protective immune responses when administered at low doses by scarification. Taken together, our data suggest that MVA and MVA-vectored

  13. Successful vaccination of immune suppressed recipients using Listeria vector HIV-1 vaccines in helminth infected mice.

    PubMed

    Shollenberger, Lisa M; Bui, Cac; Paterson, Yvonne; Allen, Kelsey; Harn, Donald

    2013-04-12

    Vaccines for HIV, malaria and TB remain high priorities, especially for sub-Saharan populations. The question is: will vaccines currently in development for these diseases function in populations that have a high prevalence of helminth infection? Infection with helminth parasites causes immune suppression and a CD4+ Th2 skewing of the immune system, thereby impairing Th1-type vaccine efficacy. In this study, we conduct HIV vaccine trials in mice with and without chronic helminth infection to mimic the human vaccine recipient populations in Sub-Saharan Africa and other helminth parasite endemic regions of the world, as there is large overlap in global prevalence for HIV and helminth infection. Here, we demonstrate that Listeria monocytogenes functions as a vaccine vector to drive robust and functional HIV-specific cellular immune responses, irrespective of chronic helminth infection. This observation represents a significant advance in the field of vaccine research and underscores the concept that vaccines in the developmental pipeline should be effective in the target populations. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Adenovirus vectored vaccines against influenza a virus do not result in vaccine associated enhanced respiratory disease following heterologous challenge in contrast to whole inactivated virus vaccine

    USDA-ARS?s Scientific Manuscript database

    Heterologous influenza A virus (IAV) challenge following vaccination with an intramuscular (IM) whole inactivated vaccine (WIV) can result in vaccine-associated enhanced respiratory disease (VAERD). The objective of this study was to use an adenovirus (Ad5) vector vaccine platform that expressed IAV...

  15. The baculovirus expression vector system: A commercial manufacturing platform for viral vaccines and gene therapy vectors.

    PubMed

    Felberbaum, Rachael S

    2015-05-01

    The baculovirus expression vector system (BEVS) platform has become an established manufacturing platform for the production of viral vaccines and gene therapy vectors. Nine BEVS-derived products have been approved - four for human use (Cervarix(®), Provenge(®), Glybera(®) and Flublok(®)) and five for veterinary use (Porcilis(®) Pesti, BAYOVAC CSF E2(®), Circumvent(®) PCV, Ingelvac CircoFLEX(®) and Porcilis(®) PCV). The BEVS platform offers many advantages, including manufacturing speed, flexible product design, inherent safety and scalability. This combination of features and product approvals has previously attracted interest from academic researchers, and more recently from industry leaders, to utilize BEVS to develop next generation vaccines, vectors for gene therapy, and other biopharmaceutical complex proteins. In this review, we explore the BEVS platform, detailing how it works, platform features and limitations and important considerations for manufacturing and regulatory approval. To underscore the growth in opportunities for BEVS-derived products, we discuss the latest product developments in the gene therapy and influenza vaccine fields that follow in the wake of the recent product approvals of Glybera(®) and Flublok(®), respectively. We anticipate that the utility of the platform will expand even further as new BEVS-derived products attain licensure. Finally, we touch on some of the areas where new BEVS-derived products are likely to emerge.

  16. The Brighton Collaboration Viral Vector Vaccines Safety Working Group (V3SWG).

    PubMed

    Chen, Robert T; Carbery, Baevin; Mac, Lisa; Berns, Kenneth I; Chapman, Louisa; Condit, Richard C; Excler, Jean-Louis; Gurwith, Marc; Hendry, Michael; Khan, Arifa S; Khuri-Bulos, Najwa; Klug, Bettina; Robertson, James S; Seligman, Stephen J; Sheets, Rebecca; Williamson, Anna-Lise

    2015-01-01

    Recombinant viral vectors provide an effective means for heterologous antigen expression in vivo and thus represent promising platforms for developing novel vaccines against human pathogens from Ebola to tuberculosis. An increasing number of candidate viral vector vaccines are entering human clinical trials. The Brighton Collaboration Viral Vector Vaccines Safety Working Group (V3SWG) was formed to improve our ability to anticipate potential safety issues and meaningfully assess or interpret safety data, thereby facilitating greater public acceptance when licensed.

  17. [Vaccination against two vector-borne diseases: bluetongue and West Nile].

    PubMed

    Zientara, Stéphan; Vitour, Damien; Lecollinet, Sylvie

    2012-03-01

    In 1999 and 2006, two viral diseases emerged massively and unexpectedly in the United States (West Nile disease) and northern Europe (bluetongue disease). Control of infectious diseases transmitted by insect vectors is based on a variety of approaches (including sanitary measures), but primarily on vaccination. Vaccination is more efficient and less expensive than monitoring of insect vectors. The dynamics and epidemiology of two arboviral diseases (West Nile and bluetongue) are described, together with the different vaccines and vaccination methods.

  18. Applications of pox virus vectors to vaccination: an update.

    PubMed

    Paoletti, E

    1996-10-15

    Recombinant pox viruses have been generated for vaccination against heterologous pathogens. Amongst these, the following are notable examples. (i) The engineering of the Copenhagen strain of vaccinia virus to express the rabies virus glycoprotein. When applied in baits, this recombinant has been shown to vaccinate the red fox in Europe and raccoons in the United States, stemming the spread of rabies virus infection in the wild. (ii) A fowlpox-based recombinant expressing the Newcastle disease virus fusion and hemagglutinin glycoproteins has been shown to protect commercial broiler chickens for their lifetime when the vaccine was administered at 1 day of age, even in the presence of maternal immunity against either the Newcastle disease virus or the pox vector. (iii) Recombinants of canarypox virus, which is restricted for replication to avian species, have provided protection against rabies virus challenge in cats and dogs, against canine distemper virus, feline leukemia virus, and equine influenza virus disease. In humans, canarypox virus-based recombinants expressing antigens from rabies virus, Japanese encephalitis virus, and HIV have been shown to be safe and immunogenic. (iv) A highly attenuated vaccinia derivative, NYVAC, has been engineered to express antigens from both animal and human pathogens. Safety and immunogenicity of NYVAC-based recombinants expressing the rabies virus glycoprotein, a polyprotein from Japanese encephalitis virus, and seven antigens from Plasmodium falciparum have been demonstrated to be safe and immunogenic in early human vaccine studies.

  19. [Recombinant viruses of poultry as vector vaccines against fowl plague].

    PubMed

    Fuchs, Walter; Veits, Jutta; Mettenleiter, Thomas C

    2006-01-01

    To help in the control of fowl plague caused by highly pathogenic avian influenza A viruses of hemagglutinin (HA) subtypes H5 and H7 several vaccines have been developed. A prophylactic immunization of poultry with inactivated influenza viruses in non-endemic situations is questionable, however, due to the impairment of serological identification of field virus-infected animals which hinders elimination of the infectious agent from the population. This problem might be overcome by the use of genetically engineered marker vaccines which contain only the protective influenza virus hemagglutinin. Infected animals could then be unambiguously identified by their serum antibodies against other influenza virus proteins, e.g. neuraminidase or nucleoprotein. For such a use, purified HA or HA-expressing DNA vaccines are conceivable. Economically advantageous and easier to apply are modified live virus vaccines in use against other poultry diseases, which have been modified to express influenza virus HA. So far, recombinant HA-expressing fowlpox virus (FPV) as well as infectious laryngotracheitis and Newcastle disease viruses have been asssessed in animal experiments. An H5-expressing FPV recombinant is already in use in Central America and Southeast Asia but without accompanying marker diagnostics. Advantages and disadvantages of the different viral vectors are discussed.

  20. Three-year duration of immunity in cats vaccinated with a canarypox-vectored recombinant rabies virus vaccine.

    PubMed

    Jas, D; Coupier, C; Toulemonde, C Edlund; Guigal, P-M; Poulet, H

    2012-11-19

    Despite the availability of efficacious vaccines for animals and humans, rabies is still a major zoonosis. Prevention of rabies in dogs and cats is key for reducing the risk of transmission of this deadly disease to humans. Most veterinary vaccines are adjuvanted inactivated vaccines and have been shown to provide one to four-year duration of immunity. In response to debates about the safety of adjuvanted vaccines in cats, a non-adjuvanted feline rabies vaccine with one-year duration of immunity claim was specifically developed using the canarypoxvirus vector technology. The objective of this study was to validate a vaccination program based on primary vaccination, revaccination one year later and boosters every three years. Seronegative cats were vaccinated at 12 weeks of age and received a booster vaccination one year later. This vaccination regimen induced a strong and sustained antibody response, and all vaccinated animals were protected against virulent rabies challenge carried out 3 years after vaccination. These results validated 3-year duration of immunity after a complete basic vaccination program consisting in primary vaccination from 12 weeks of age followed by revaccination one year later with a non-adjuvanted canarypox-vectored vaccine.

  1. Characterization of recombinant Raccoonpox Vaccine Vectors in Chickens

    USGS Publications Warehouse

    Hwa, S.-H.; Iams, Keith P.; Hall, Jeffrey S.; Kingstad, B.A.; Osorio, Jorge E.

    2010-01-01

    Raccoonpox virus (RCN) has been used as a recombinant vector against several mammalian pathogens but has not been tested in birds. The replication of RCN in chick embryo fibroblasts (CEFs) and chickens was studied with the use of highly pathogenic avian influenza virus H5N1 hemagglutinin (HA) as a model antigen and luciferase (luc) as a reporter gene. Although RCN replicated to low levels in CEFs, it efficiently expressed recombinant proteins and, in vivo, elicited anti-HA immunoglobulin yolk (IgY) antibody responses comparable to inactivated influenza virus. Biophotonic in vivo imaging of 1-wk-old chicks with RCN-luc showed strong expression of the luc reporter gene lasting up to 3 days postinfection. These studies demonstrate the potential of RCN as a vaccine vector for avian influenza and other poultry pathogens. ?? American Association of Avian Pathologists 2010.

  2. Alphavirus vectors for vaccine production and gene therapy.

    PubMed

    Lundstrom, Kenneth

    2003-06-01

    Alphavirus vectors demonstrate high expression of heterologous proteins in a broad range of host cells. Replication-deficient as well as replication-competent variants exist. Systemic delivery of many viral antigens has elicited strong antibody responses in immunized mice and primates, and protection against challenges with lethal viruses was obtained. Similarly, prophylactic vaccination was established against tumor challenges. Attention has been paid to the engineering of improved targeting to immunologically active cells, such as dendritic cells. In the area of gene therapy, intratumoral injections of alphavirus vectors have resulted in potentially promising tumor rejection. Moreover, encapsulation of alphavirus particles into liposomes demonstrated efficient tumor targeting in mice with severe combined immunodeficiency, which permitted the initiation of clinical trials for patients with advanced kidney carcinoma and melanoma.

  3. Humoral Immunity to Primary Smallpox Vaccination: Impact of Childhood versus Adult Immunization on Vaccinia Vector Vaccine Development in Military Populations

    PubMed Central

    Slike, Bonnie M.; Creegan, Matthew

    2017-01-01

    Modified Vaccinia virus has been shown to be a safe and immunogenic vector platform for delivery of HIV vaccines. Use of this vector is of particular importance to the military, with the implementation of a large scale smallpox vaccination campaign in 2002 in active duty and key civilian personnel in response to potential bioterrorist activities. Humoral immunity to smallpox vaccination was previously shown to be long lasting (up to 75 years) and protective. However, using vaccinia-vectored vaccine delivery for other diseases on a background of anti-vector antibodies (i.e. pre-existing immunity) may limit their use as a vaccine platform, especially in the military. In this pilot study, we examined the durability of vaccinia antibody responses in adult primary vaccinees in a healthy military population using a standard ELISA assay and a novel dendritic cell neutralization assay. We found binding and neutralizing antibody (NAb) responses to vaccinia waned after 5–10 years in a group of 475 active duty military, born after 1972, who were vaccinated as adults with Dryvax®. These responses decreased from a geometric mean titer (GMT) of 250 to baseline (<20) after 10–20 years post vaccination. This contrasted with a comparator group of adults, ages 35–49, who were vaccinated with Dryvax® as children. In the childhood vaccinees, titers persisted for >30 years with a GMT of 210 (range 112–3234). This data suggests limited durability of antibody responses in adult vaccinees compared to those vaccinated in childhood and further that adult vaccinia recipients may benefit similarly from receipt of a vaccinia based vaccine as those who are vaccinia naïve. Our findings may have implications for the smallpox vaccination schedule and support the ongoing development of this promising viral vector in a military vaccination program. PMID:28046039

  4. Humoral Immunity to Primary Smallpox Vaccination: Impact of Childhood versus Adult Immunization on Vaccinia Vector Vaccine Development in Military Populations.

    PubMed

    Slike, Bonnie M; Creegan, Matthew; Marovich, Mary; Ngauy, Viseth

    2017-01-01

    Modified Vaccinia virus has been shown to be a safe and immunogenic vector platform for delivery of HIV vaccines. Use of this vector is of particular importance to the military, with the implementation of a large scale smallpox vaccination campaign in 2002 in active duty and key civilian personnel in response to potential bioterrorist activities. Humoral immunity to smallpox vaccination was previously shown to be long lasting (up to 75 years) and protective. However, using vaccinia-vectored vaccine delivery for other diseases on a background of anti-vector antibodies (i.e. pre-existing immunity) may limit their use as a vaccine platform, especially in the military. In this pilot study, we examined the durability of vaccinia antibody responses in adult primary vaccinees in a healthy military population using a standard ELISA assay and a novel dendritic cell neutralization assay. We found binding and neutralizing antibody (NAb) responses to vaccinia waned after 5-10 years in a group of 475 active duty military, born after 1972, who were vaccinated as adults with Dryvax®. These responses decreased from a geometric mean titer (GMT) of 250 to baseline (<20) after 10-20 years post vaccination. This contrasted with a comparator group of adults, ages 35-49, who were vaccinated with Dryvax® as children. In the childhood vaccinees, titers persisted for >30 years with a GMT of 210 (range 112-3234). This data suggests limited durability of antibody responses in adult vaccinees compared to those vaccinated in childhood and further that adult vaccinia recipients may benefit similarly from receipt of a vaccinia based vaccine as those who are vaccinia naïve. Our findings may have implications for the smallpox vaccination schedule and support the ongoing development of this promising viral vector in a military vaccination program.

  5. Replicating adenovirus vector prime/protein boost strategies for HIV vaccine development

    PubMed Central

    Patterson, L. Jean; Robert-Guroff, Marjorie

    2008-01-01

    Background In the last few years the HIV vaccine field has moved forward a number of promising vaccine candidates into human clinical trials. Objective In this review we briefly discuss the advances made in vaccine development and HIV pathogenesis and give an overview of the body of work our lab has generated in multiple animal models on replication-competent Ad recombinant vaccines. Methods Emphasis is placed on comparative examination of vaccine components, routes of immunization and challenge models using replicating Ad vectors. Results/conclusion The overall findings make the case that replicating Ad vectors are superior in priming multiple arms of the immune system, and in conjunction with protein boosting, have resulted in dramatic protective efficacy leading to their advancement to phase 1 trials. Implications of the recent halting of the Merck Ad5-HIV phase 2b clinical trial for our vaccine approach and other vectored vaccines are discussed. PMID:18694354

  6. Pre-existing immunity against vaccine vectors – friend or foe?

    PubMed Central

    Saxena, Manvendra; Van, Thi Thu Hao; Baird, Fiona J.; Coloe, Peter J.

    2013-01-01

    Over the last century, the successful attenuation of multiple bacterial and viral pathogens has led to an effective, robust and safe form of vaccination. Recently, these vaccines have been evaluated as delivery vectors for heterologous antigens, as a means of simultaneous vaccination against two pathogens. The general consensus from published studies is that these vaccine vectors have the potential to be both safe and efficacious. However, some of the commonly employed vectors, for example Salmonella and adenovirus, often have pre-existing immune responses in the host and this has the potential to modify the subsequent immune response to a vectored antigen. This review examines the literature on this topic, and concludes that for bacterial vectors there can in fact, in some cases, be an enhancement in immunogenicity, typically humoral, while for viral vectors pre-existing immunity is a hindrance for subsequent induction of cell-mediated responses. PMID:23175507

  7. Adenovirus vector-based vaccines for human immunodeficiency virus type 1.

    PubMed

    Barouch, Dan H; Nabel, Gary J

    2005-02-01

    Recombinant adenovirus (rAd) vectors have received considerable attention for gene therapy because of their high transduction efficiency. However, recombinant gene expression from rAd vectors elicits rapid and potent immune responses to foreign transgene products. Such immunogenicity limits the duration of transgene expression and poses a major challenge to the use of rAd vectors for gene therapy. In contrast, the inherent immunogenicity of these vectors is a desirable feature for vaccine development. The immunogenicity and protective efficacy of rAd vector-based vaccines have now been demonstrated in a number of animal models, and rAd vaccines for a variety of pathogens are currently being explored in early-phase clinical trials. In this review, we describe progress in the development of rAd vector-based vaccines with a focus on human immunodeficiency virus type 1.

  8. Aerosol immunization with NYVAC and MVA vectored vaccines is safe, simple, and immunogenic

    PubMed Central

    Corbett, Max; Bogers, Willy M.; Heeney, Jonathan L.; Gerber, Stefan; Genin, Christian; Didierlaurent, Arnaud; Oostermeijer, Herman; Dubbes, Rob; Braskamp, Gerco; Lerondel, Stéphanie; Gomez, Carmen E.; Esteban, Mariano; Wagner, Ralf; Kondova, Ivanella; Mooij, Petra; Balla-Jhagjhoorsingh, Sunita; Beenhakker, Niels; Koopman, Gerrit; van der Burg, Sjoerd; Kraehenbuhl, Jean-Pierre; Le Pape, Alain

    2008-01-01

    Each year, approximately five million people die worldwide from putatively vaccine-preventable mucosally transmitted diseases. With respect to mass vaccination campaigns, one strategy to cope with this formidable challenge is aerosol vaccine delivery, which offers potential safety, logistical, and cost-saving advantages over traditional vaccination routes. Additionally, aerosol vaccination may elicit pivotal mucosal immune responses that could contain or eliminate mucosally transmitted pathogens in a preventative or therapeutic vaccine context. In this current preclinical non-human primate investigation, we demonstrate the feasibility of aerosol vaccination with the recombinant poxvirus-based vaccine vectors NYVAC and MVA. Real-time in vivo scintigraphy experiments with radiolabeled, aerosol-administered NYVAC-C (Clade C, HIV-1 vaccine) and MVA-HPV vaccines revealed consistent mucosal delivery to the respiratory tract. Furthermore, aerosol delivery of the vaccines was safe, inducing no vaccine-associated pathology, in particular in the brain and lungs, and was immunogenic. Administration of a DNA-C/NYVAC-C prime/boost regime resulted in both systemic and anal-genital HIV-specific immune responses that were still detectable 5 months after immunization. Thus, aerosol vaccination with NYVAC and MVA vectored vaccines constitutes a tool for large-scale vaccine efforts against mucosally transmitted pathogens. PMID:18270165

  9. Vector-transmitted disease vaccines: targeting salivary proteins in transmission (SPIT).

    PubMed

    McDowell, Mary Ann

    2015-08-01

    More than half the population of the world is at risk for morbidity and mortality from vector-transmitted diseases, and emerging vector-transmitted infections are threatening new populations. Rising insecticide resistance and lack of efficacious vaccines highlight the need for novel control measures. One such approach is targeting the vector-host interface by incorporating vector salivary proteins in anti-pathogen vaccines. Debate remains about whether vector saliva exposure exacerbates or protects against more severe clinical manifestations, induces immunity through natural exposure or extends to all vector species and associated pathogens. Nevertheless, exploiting this unique biology holds promise as a viable strategy for the development of vaccines against vector-transmitted diseases.

  10. Increased Mucosal CD4+ T Cell Activation in Rhesus Macaques following Vaccination with an Adenoviral Vector

    PubMed Central

    Bukh, Irene; Calcedo, Roberto; Roy, Soumitra; Carnathan, Diane G.; Grant, Rebecca; Qin, Qiuyue; Boyd, Surina; Ratcliffe, Sarah J.; Veeder, Christin L.; Bellamy, Scarlett L.; Betts, Michael R.

    2014-01-01

    ABSTRACT The possibility that vaccination with adenovirus (AdV) vectors increased mucosal T cell activation remains a central hypothesis to explain the potential enhancement of HIV acquisition within the Step trial. Modeling this within rhesus macaques is complicated because human adenoviruses, including human adenovirus type 5 (HAdV-5), are not endogenous to macaques. Here, we tested whether vaccination with a rhesus macaque-derived adenoviral vector (simian adenovirus 7 [SAdV-7]) enhances mucosal T cell activation within rhesus macaques. Following intramuscular SAdV-7 vaccination, we observed a pronounced increase in SAdV-7-specific CD4+ T cell responses in peripheral blood and, more dramatically, in rectal mucosa tissue. Vaccination also induced a significant increase in the frequency of activated memory CD4+ T cells in SAdV-7- and HAdV-5-vaccinated animals in the rectal mucosa but not in peripheral blood. These fluctuations within the rectal mucosa were also associated with a pronounced decrease in the relative frequency of naive resting CD4+ T cells. Together, these results indicate that peripheral vaccination with an AdV vector can increase the activation of mucosal CD4+ T cells, potentially providing an experimental model to further evaluate the role of host-vector interactions in increased HIV acquisition after AdV vector vaccination. IMPORTANCE The possibility that vaccination with a human adenovirus 5 vector increased mucosal T cell activation remains a central hypothesis to explain the potential enhancement of human immunodeficiency virus (HIV) acquisition within the Step trial. In this study, we tested whether vaccination with a rhesus macaque-derived adenoviral vector in rhesus macaques enhances mucosal CD4+ T cell activation, the main cell target of simian immunodeficiency virus (SIV)/HIV. The results showed that vaccination with an adenoviral vector indeed increases activation of mucosal CD4+ T cells and potentially increases susceptibility to SIV

  11. Baculovirus vector as an avian influenza vaccine: hemagglutinin expression and presentation augment the vaccine immunogenicity.

    PubMed

    Chen, Chi-Yuan; Lin, Shih-Yeh; Cheng, Ming-Chu; Tsai, Ching-Ping; Hung, Chang-Lin; Lo, Kai-Wei; Hwang, Yung; Hu, Yu-Chen

    2013-03-10

    Baculovirus simultaneously displaying and expressing the avian influenza virus (AIV) hemagglutinin (HA) protein can induce potent anti-HA humoral and cellular immune responses. Based on the hypothesis that improving the antigen expression and presentation can further boost the AIV vaccine efficacies, we first constructed a baculoviral vector (Bac-HAW) with HA gene fused with the woodchuck hepatitis virus post-transcriptional regulatory element (WPRE) near its 3' end and expressed under the control of the hybrid CAG promoter. The WPRE fusion improved the HA expression and augmented the humoral and Th1 cellular immune responses after intramuscular administration into BALB/c mice. With Bac-HAW as the backbone, we next constructed Bac-HAMW which harbored the HA gene flanked with the signal sequence (MHCIss) and trafficking domain (MITD) of MHC class I molecule. In comparison with Bac-HAW, Bac-HAMW ameliorated the HA peptide presentation, significantly elevated the HA-specific humoral response (total IgG, IgG2a and hemagglutination inhibition titers) and favorably boosted the Th1 and IFN-γ(+)/CD8(+) T cell responses without extraneous adjuvants. These data collectively confirmed that enhancement of antigen expression and presentation by combining the WPRE and MHCIss/MITD fusion can potentiate the immunogenicity of the baculovirus-based vaccine, and implicates the potential of Bac-HAMW as an appealing AIV vaccine.

  12. Vaccination with proteins involved in tick-pathogen interactions reduces vector infestations and pathogen infection.

    PubMed

    Merino, Octavio; Antunes, Sandra; Mosqueda, Juan; Moreno-Cid, Juan A; Pérez de la Lastra, José M; Rosario-Cruz, Rodrigo; Rodríguez, Sergio; Domingos, Ana; de la Fuente, José

    2013-12-02

    Tick-borne pathogens cause diseases that greatly impact animal health and production worldwide. The ultimate goal of tick vaccines is to protect against tick-borne diseases through the control of vector infestations and reducing pathogen infection and transmission. Tick genetic traits are involved in vector-pathogen interactions and some of these molecules such as Subolesin (SUB) have been shown to protect against vector infestations and pathogen infection. Based on these premises, herein we characterized the efficacy of cattle vaccination with tick proteins involved in vector-pathogen interactions, TROSPA, SILK, and Q38 for the control of cattle tick, Rhipicephalus (Boophilus) microplus infestations and infection with Anaplasma marginale and Babesia bigemina. SUB and adjuvant/saline placebo were used as positive and negative controls, respectively. The results showed that vaccination with Q38, SILK and SUB reduced tick infestations and oviposition with vaccine efficacies of 75% (Q38), 62% (SILK) and 60% (SUB) with respect to ticks fed on placebo control cattle. Vaccination with TROSPA did not have a significant effect on any of the tick parameters analyzed. The results also showed that vaccination with Q38, TROSPA and SUB reduced B. bigemina DNA levels in ticks while vaccination with SILK and SUB resulted in lower A. marginale DNA levels when compared to ticks fed on placebo control cattle. The positive correlation between antigen-specific antibody titers and reduction of tick infestations and pathogen infection strongly suggested that the effect of the vaccine was the result of the antibody response in vaccinated cattle. Vaccination and co-infection with A. marginale and B. bigemina also affected the expression of genes encoding for vaccine antigens in ticks fed on cattle. These results showed that vaccines using tick proteins involved in vector-pathogen interactions could be used for the dual control of tick infestations and pathogen infection. Copyright © 2013

  13. Replicating Single-Cycle Adenovirus Vectors Generate Amplified Influenza Vaccine Responses

    PubMed Central

    Crosby, Catherine M.; Matchett, William E.; Anguiano-Zarate, Stephanie S.; Parks, Christopher A.; Weaver, Eric A.; Pease, Larry R.; Webby, Richard J.

    2016-01-01

    ABSTRACT Head-to-head comparisons of conventional influenza vaccines with adenovirus (Ad) gene-based vaccines demonstrated that these viral vectors can mediate more potent protection against influenza virus infection in animal models. In most cases, Ad vaccines are engineered to be replication-defective (RD-Ad) vectors. In contrast, replication-competent Ad (RC-Ad) vaccines are markedly more potent but risk causing adenovirus diseases in vaccine recipients and health care workers. To harness antigen gene replication but avoid production of infectious virions, we developed “single-cycle” adenovirus (SC-Ad) vectors. Previous work demonstrated that SC-Ads amplify transgene expression 100-fold and produce markedly stronger and more persistent immune responses than RD-Ad vectors in Syrian hamsters and rhesus macaques. To test them as potential vaccines, we engineered RD and SC versions of adenovirus serotype 6 (Ad6) to express the hemagglutinin (HA) gene from influenza A/PR/8/34 virus. We show here that it takes approximately 33 times less SC-Ad6 than RD-Ad6 to produce equal amounts of HA antigen in vitro. SC-Ad produced markedly higher HA binding and hemagglutination inhibition (HAI) titers than RD-Ad in Syrian hamsters. SC-Ad-vaccinated cotton rats had markedly lower influenza titers than RD-Ad-vaccinated animals after challenge with influenza A/PR/8/34 virus. These data suggest that SC-Ads may be more potent vaccine platforms than conventional RD-Ad vectors and may have utility as “needle-free” mucosal vaccines. IMPORTANCE Most adenovirus vaccines that are being tested are replication-defective adenoviruses (RD-Ads). This work describes testing newer single-cycle adenovirus (SC-Ad) vectors that replicate transgenes to amplify protein production and immune responses. We show that SC-Ads generate markedly more influenza virus hemagglutinin protein and require substantially less vector to generate the same immune responses as RD-Ad vectors. SC-Ads therefore hold

  14. Efficacy assessment of an MVA vectored Rift Valley Fever vaccine in lambs.

    PubMed

    Busquets, Núria; Lorenzo, Gema; López-Gil, Elena; Rivas, Raquel; Solanes, David; Galindo-Cardiel, Iván; Abad, F Xavier; Rodríguez, Fernando; Bensaid, Albert; Warimwe, George; Gilbert, Sarah C; Domingo, Mariano; Brun, Alejandro

    2014-08-01

    The present study has evaluated the protection conferred by a single subcutaneous dose of a modified vaccinia virus Ankara (MVA) vectored vaccine encoding the Rift Valley Fever virus (RVFV) glycoproteins Gn and Gc in lambs. Three groups of six to seven lambs were immunized as follows: one group received the vaccine (termed rMVA-GnGc), a second group received an MVA vector (vector control) and a third group received saline solution (non-vaccinated control). Fourteen days later, all animals were subcutaneously challenged with 10(5) TCID50 of the virulent RVFV isolate 56/74 and vaccine efficacy assessed using standard endpoints. Two lambs (one from the vaccine group and one from the vector control group) succumbed to RVFV challenge, showing characteristic liver lesions. Lambs from both the vector control and non-vaccinated groups were febrile from days 2 to 5 post challenge (pc) while those in the rMVA-GnGc group showed a single peak of pyrexia at day 3 pc. RVFV RNA was detected in both nasal and oral swabs from days 3 to 7 pc in some lambs from the vector control and non-vaccinated groups, but no viral shedding could be detected in the surviving lambs vaccinated with rMVA-GnGc. Together, the data suggest that a single dose of the rMVA-GnGc vaccine may be sufficient to reduce RVFV shedding and duration of viremia but does not provide sterile immunity nor protection from disease. Further optimization of this vaccine approach in lambs is warranted.

  15. Bacteroides Fragilis OMP A: Utility as a Live Vaccine Vector for Biodefense Agents

    DTIC Science & Technology

    2006-01-01

    1-0145 TITLE: Bacteroides Fragilis OMP A: Utility as a Live Vaccine Vector for Biodefense Agents...From - To) 30 DEC 2004 - 29 DEC 2005 4. TITLE AND SUBTITLE Bacteroides Fragilis OMP A: Utility as a Live Vaccine Vector for Biodefense Agents 5a...negative anaerobe that normally resides in the gut . There are four homologs for ompA in the genome. The purpose of this study was to construct a B

  16. Development of a novel thermostable Newcastle disease virus vaccine vector for expression of a heterologous gene

    USDA-ARS?s Scientific Manuscript database

    The thermostable Newcastle disease virus (NDV) vaccines have been used widely to control Newcastle disease (ND) for village flocks, due to their independence of cold chains for delivery and storage. To explore the potential use of the thermostable NDV as a vaccine vector, an infectious clone of the...

  17. Protection of chickens against avian influenza with non-replicating adenovirus-vectored vaccine

    USDA-ARS?s Scientific Manuscript database

    Protective immunity against avian influenza (AI) virus was elicited in chickens by single-dose vaccination with a replication competent adenovirus (RCA) -free human adenovirus (Ad) vector encoding a H7 hemagglutinin gene from a low pathogenic North American isolate (AdChNY94.H7). Chickens vaccinate...

  18. A novel thermostable Newcastle disease virus vaccine vector for expression of a heterologous gene

    USDA-ARS?s Scientific Manuscript database

    The thermostable Newcastle disease virus (NDV) vaccines have been used widely to control Newcastle disease for village flocks, especially in the developing countries. To explore the potential use of the thermostable NDV as a vaccine vector, a reverse genetic system for the thermostable avirulent NDV...

  19. Recombinant viral vectored vaccines for the control of avian influenza: a review

    USDA-ARS?s Scientific Manuscript database

    The poultry industry has been at the forefront of developing recombinant viral vectored vaccines in an attempt to improve the immune response to vaccination. With AIV, the hemagglutinin surface glycoprotein is the key antigen for protection against infection. This allows a single gene to be transf...

  20. A Novel Vaccine Approach for Chagas Disease Using Rare Adenovirus Serotype 48 Vectors

    PubMed Central

    Farrow, Anitra L.; Peng, Binghao J.; Gu, Linlin; Krendelchtchikov, Alexandre; Matthews, Qiana L.

    2016-01-01

    Due to the increasing amount of people afflicted worldwide with Chagas disease and an increasing prevalence in the United States, there is a greater need to develop a safe and effective vaccine for this neglected disease. Adenovirus serotype 5 (Ad5) is the most common adenovirus vector used for gene therapy and vaccine approaches, but its efficacy is limited by preexisting vector immunity in humans resulting from natural infections. Therefore, we have employed rare serotype adenovirus 48 (Ad48) as an alternative choice for adenovirus/Chagas vaccine therapy. In this study, we modified Ad5 and Ad48 vectors to contain T. cruzi’s amastigote surface protein 2 (ASP-2) in the adenoviral early gene. We also modified Ad5 and Ad48 vectors to utilize the “Antigen Capsid-Incorporation” strategy by adding T. cruzi epitopes to protein IX (pIX). Mice that were immunized with the modified vectors were able to elicit T. cruzi-specific humoral and cellular responses. This study indicates that Ad48-modified vectors function comparable to or even premium to Ad5-modified vectors. This study provides novel data demonstrating that Ad48 can be used as a potential adenovirus vaccine vector against Chagas disease. PMID:26978385

  1. Three-year duration of immunity in dogs vaccinated with a canarypox-vectored recombinant canine distemper virus vaccine.

    PubMed

    Larson, L J; Schultz, R D

    2007-01-01

    Two studies evaluated the duration of serologic response to the recombinant, canarypox-vectored canine distemper virus vaccine (Recombitek, Merial). Serologic duration of immunity was shown to be at least 36 months. Thus, Recombitek provides protection when administered less frequently than the manufacturer's label. After the initial vaccination protocol of two or more doses administered approximately 4 weeks apart, with the last dose given at 12 to 16 weeks of age or older, and re-vaccination at 1 year of age, Recombitek can confidently be readministered every 3 years with assurance of protection in immunocompetent dogs. This allows the vaccine to be administered in accordance with the recommendations of the American Animal Hospital Association Canine Vaccine Task Force and others.

  2. Potent tetravalent replicon vaccines against botulinum neurotoxins using DNA-based Semliki Forest virus replicon vectors.

    PubMed

    Yu, Yun-Zhou; Guo, Jin-Peng; An, Huai-Jie; Zhang, Shu-Ming; Wang, Shuang; Yu, Wei-Yuan; Sun, Zhi-Wei

    2013-05-07

    Human botulism is commonly associated with botulinum neurotoxin (BoNT) serotypes A, B, E and F. This suggests that the greatest need is for a tetravalent vaccine that provides protection against all four of these serotypes. In current study, we investigated the feasibility of generating several tetravalent vaccines that protected mice against the four serotypes. Firstly, monovalent replicon vaccine against BoNT induced better antibody response and protection than that of corresponding conventional DNA vaccine. Secondly, dual-expression DNA replicon pSCARSE/FHc or replicon particle VRP-E/FHc vaccine was well resistant to the challenge of BoNT/E and BoNT/F mixture as a combination vaccine composed of two monovalent replicon vaccines. Finally, the dual-expression DNA replicon or replicon particle tetravalent vaccine could simultaneously and effectively neutralize and protect the four BoNT serotypes. Protection correlated directly with serum ELISA titers and neutralization antibody levels to BoNTs. Therefore, replicon-based DNA or particle might be effective vector to develop BoNT vaccines, which might be more desirable for use in clinical application than the conventional DNA vaccines. Our studies demonstrate the utility of combining dual-expression DNA replicon or replicon particle vaccines into multi-agent formulations as potent tetravalent vaccines for eliciting protective responses to four serotypes of BoNTs.

  3. Comparison of antibody response to a non-adjuvanted, live canarypox-vectored recombinant rabies vaccine and a killed, adjuvanted rabies vaccine in Eld's deer (Rucervus eldi thamin).

    PubMed

    Marrow, Judilee C; Padilla, Luis R; Hayek, Lee-Ann C; Bush, Mitch; Murray, Suzan

    2014-06-01

    Captive Eld's deer (Rucervus eldi thamin) were evaluated for the presence of rabies virus-neutralizing antibodies using a rapid fluorescent focus inhibition after vaccination with either a live canarypox-vectored recombinant rabies vaccine or a killed monovalent rabies vaccine. Twelve deer were vaccinated with 1.0 ml of killed, adjuvanted, monovalent rabies vaccine at 5-33 mo of age then annually thereafter, and 14 deer were vaccinated with 1.0 ml nonadjuvanted, live canarypox-vectored rabies vaccine at 3-15 mo of age then annually thereafter. Banked serum was available or collected prospectively from deer at 6 mo and 1 yr after initial vaccination, then collected annually. Rabies virus-neutralizing antibodies considered adequate (>0.5 IU/ml) were present in 20/34 samples vaccinated with canarypox-vectored rabies vaccine and in 12/14 samples vaccinated with killed adjuvanted rabies vaccine. Poor seroconversion was noted in deer less than 6 mo of age vaccinated with the canarypox-vectored rabies vaccine.

  4. Salmonella enterica serovar Typhi Live Vector Vaccines Finally Come of Age

    PubMed Central

    Galen, James E.; Pasetti, Marcela F.; Tennant, Sharon; Olveira-Ruiz, Patricia; Sztein, Marcelo B.; Levine, Myron M.

    2013-01-01

    Attenuated bacterial vaccine strains hold great promise as live vectors for presentation of foreign antigens from unrelated bacterial, viral, and parasitic pathogens to the immune system. While this approach has proven quite successful in experimental animal models for eliciting antigen-specific mucosal, humoral, and cellular responses, results have been disappointing for clinical trials carried out thus far. We hypothesize that the paucity of human responses to foreign antigens delivered by live vectors suggests that the strains and genetic approaches used to date have resulted in over-attenuated vaccine strains with severely reduced immunogenicity. However, remarkable advances have now been made in the genetics of foreign antigen expression, understanding mechanisms of live vector immunity, and refining immunization strategies. The time has now come for development of multivalent live vectors in which stable antigen expression is balanced with metabolic fitness to create highly immunogenic vaccines. PMID:19417771

  5. Beyond Oncolytics: E1B55K-Deleted Adenovirus as a Vaccine Delivery Vector

    PubMed Central

    Thomas, Michael A.; Nyanhete, Tinashe; Tuero, Iskra; Venzon, David; Robert-Guroff, Marjorie

    2016-01-01

    Type 5 human adenoviruses (Ad5) deleted of genes encoding the early region 1B 55-kDa (E1B55K) protein including Onyx-015 (dl1520) and H101 are best known for their oncolytic potential. As a vaccine vector the E1B55K deletion may allow for the insertion of a transgene nearly 1,000 base pairs larger than now possible. This has the potential of extending the application for which the vectors are clinically known. However, the immune priming ability of E1B55K-deleted vectors is unknown, undermining our ability to gauge their usefulness in vaccine applications. For this reason, we created an E1B55K-deleted Ad5 vector expressing full-length single chain HIVBaLgp120 attached to a flexible linker and the first two domains of rhesus CD4 (rhFLSC) in exchange for the E3 region. In cell-based experiments the E1B55K-deleted vector promoted higher levels of innate immune signals including chemokines, cytokines, and the NKG2D ligands MIC A/B compared to an E1B55K wild-type vector expressing the same immunogen. Based on these results we evaluated the immune priming ability of the E1B55K-deleted vector in mice. The E1B55K-deleted vector promoted similar levels of Ad5-, HIVgp120, and rhFLSC-specific cellular and humoral immune responses as the E1B55K wild-type vector. In pre-clinical HIV-vaccine studies the wild-type vector has been employed as part of a very effective prime-boost strategy. This study demonstrates that E1B55K-deleted adenoviruses may serve as effective vaccine delivery vectors. PMID:27391605

  6. Potentiation of anthrax vaccines using protective antigen-expressing viral replicon vectors.

    PubMed

    Wang, Hai-Chao; An, Huai-Jie; Yu, Yun-Zhou; Xu, Qing

    2015-02-01

    DNA vaccines require improvement for human use because they are generally weak stimulators of the immune system in humans. The efficacy of DNA vaccines can be improved using a viral replicon as vector to administer antigen of pathogen. In this study, we comprehensively evaluated the conventional non-viral DNA, viral replicon DNA or viral replicon particles (VRP) vaccines encoding different forms of anthrax protective antigen (PA) for specific immunity and protective potency against anthrax. Our current results clearly suggested that these viral replicon DNA or VRP vaccines derived from Semliki Forest virus (SFV) induced stronger PA-specific immune responses than the conventional non-viral DNA vaccines when encoding the same antigen forms, which resulted in potent protection against challenge with the Bacillus anthracis strain A16R. Additionally, the naked PA-expressing SFV replicon DNA or VRP vaccines without the need for high doses or demanding particular delivery regimens elicited robust immune responses and afforded completely protective potencies, which indicated the potential of the SFV replicon as vector of anthrax vaccines for use in clinical application. Therefore, our results suggest that these PA-expressing SFV replicon DNA or VRP vaccines may be suitable as candidate vaccines against anthrax.

  7. The Effect of Vector Silencing during Picornavirus Vaccination against Experimental Melanoma and Glioma

    PubMed Central

    Renner, Danielle N.; Huseby Kelcher, April M.; Jin, Fang; Hansen, Michael J.; Pavelko, Kevin D.; Johnson, Aaron J.

    2016-01-01

    Virus vector-based vaccination against tumor-specific antigens remains a promising therapeutic approach to overcome the immune suppressive tumor microenvironment. However, the extent that the desired CD8 T cell response against the targeted tumor antigen is impacted by the CD8 T cell response against the virus vector is unclear. To address this question, we used picornavirus vaccination with Theiler’s murine encephalomyelitis virus (TMEV) as our vector against tumor-expressed ovalbumin (OVA257-264) antigen in both the B16-OVA murine melanoma and GL261-quad cassette murine glioma models. Prior to vaccination, we employed vector silencing to inhibit the CD8 T cell response against the immunodominant TMEV antigen, VP2121-130. We then monitored the resulting effect on the CD8 T cell response against the targeted tumor-specific antigen, ovalbumin. We demonstrate that employing vector silencing in the context of B16-OVA melanoma does not reduce tumor burden or improve survival, while TMEV-OVA vaccination without vector silencing controls tumor burden. Meanwhile, employing vector silencing during picornavirus vaccination against the GL261-quad cassette glioma resulted in a lower frequency of tumor antigen-specific CD8 T cells. The results of this study are relevant to antigen-specific immunotherapy, in that the virus vector-specific CD8 T cell response is not competing with tumor antigen-specific CD8 T cells. Furthermore, vector silencing may have the adverse consequence of reducing the tumor antigen-specific CD8 T cell response, as demonstrated by our findings in the GL261-quad cassette model. PMID:27560502

  8. Further development of raccoon poxvirus-vectored vaccines against plague (Yersinia pestis).

    PubMed

    Rocke, Tonie E; Iams, Keith P; Dawe, Sandra; Smith, Susan R; Williamson, Judy L; Heisey, Dennis M; Osorio, Jorge E

    2009-12-11

    In previous studies, we demonstrated protection against plague in mice and prairie dogs using a raccoon pox (RCN) virus-vectored vaccine that expressed the F1 capsular antigen of Yersinia pestis. In order to improve vaccine efficacy, we have now constructed additional RCN-plague vaccines containing two different forms of the lcrV (V) gene, including full-length (Vfull) and a truncated form (V307). Mouse challenge studies with Y. pestis strain CO92 showed that vaccination with a combination of RCN-F1 and the truncated V construct (RCN-V307) provided the greatest improvement (P=0.01) in protection against plague over vaccination with RCN-F1 alone. This effect was mediated primarily by anti-F1 and anti-V antibodies and both contributed independently to increased survival of vaccinated mice.

  9. Further development of raccoon poxvirus-vectored vaccines against plague (Yersinia pestis)

    USGS Publications Warehouse

    Rocke, T.E.; Iams, Keith P.; Dawe, S.; Smith, S.R.; Williamson, J.L.; Heisey, D.M.; Osorio, J.E.

    2009-01-01

    In previous studies, we demonstrated protection against plague in mice and prairie dogs using a raccoon pox (RCN) virus-vectored vaccine that expressed the F1 capsular antigen of Yersinia pestis. In order to improve vaccine efficacy, we have now constructed additional RCN-plague vaccines containing two different forms of the lcrV (V) gene, including full-length (Vfull) and a truncated form (V307). Mouse challenge studies with Y. pestis strain CO92 showed that vaccination with a combination of RCN-F1 and the truncated V construct (RCN-V307) provided the greatest improvement (P = 0.01) in protection against plague over vaccination with RCN-F1 alone. This effect was mediated primarily by anti-F1 and anti-V antibodies and both contributed independently to increased survival of vaccinated mice.

  10. The recombinant EHV-1 vector producing CDV hemagglutinin as potential vaccine against canine distemper.

    PubMed

    Pan, Zihao; Liu, Jin; Ma, Jiale; Jin, Qiuli; Yao, Huochun; Osterrieder, Nikolaus

    2017-10-01

    Canine distemper virus (CDV), is a pantropic agent of morbillivirus that causes fetal disease in dogs. Base on a broad host rang of CDV, the continued vaccines inoculation is unavoidable to pose gene recombination risk in vaccine virus and wild virus. The current study presents the construction of novel vectors, using equine herpesvirus type 1 (EHV-1) expressing the canine distemper virus (CDV). The recent field strain hemagglutinin protein and nucleoprotein were used for the construction of the viral vector vaccines. Based on the Bacterial artificial chromosome (BAC) genomes of EHV-1 RacH strain, the recombinant EHV-1 vaccine virus encoding CDV hemagglutinin protein (EHV-H) or CDV nucleoprotein (EHV-N) was constructed separately. The constructed BACs were rescued after 72 h post infection, and the expression of H or N in the recombinant viruses was confirmed by western-blotting. Furthermore, high levels of neutralizing antibodies were induced persistently following vaccination in the groups EHV-H&EHV-N and EHV-H, but the EHV-N group. The groups of vaccinated EHV-H and EHV-H&EHV-N pups were monitored for clinical signs, whereas the vaccinated EHV-N group developed moderate symptoms. The present study demonstrated that EHV-1 based recombinant virus carrying CDV H could be a promising vaccine candidate against canine distemper. Copyright © 2017. Published by Elsevier Ltd.

  11. Human adenovirus-vectored foot-and-mouth disease vaccines: establishment of a vaccine product profile through in vitro testing.

    PubMed

    Brake, D A; McIlhaney, M; Miller, T; Christianson, K; Keene, A; Lohnas, G; Purcell, C; Neilan, J; Schutta, C; Barrera, J; Burrage, T; Brough, D E; Butman, B T

    2012-01-01

    Next generation, foot-and-mouth disease (FMD) molecular vaccines based on replication deficient human adenovirus serotype 5 viral vectored delivery of FMD capsid genes (AdFMD) are being developed by the United States Dept. of Homeland Security and industry partners. The strategic goal of this program is to develop AdFMD licensed vaccines for the USA National Veterinary Stockpile for use, if needed, as emergency response tools during an FMD outbreak. This vaccine platform provides a unique opportunity to develop a set of in vitro analytical parameters to generate an AdFMD vaccine product profile to replace the current lot release test for traditional, inactivated FMD vaccines that requires FMDV challenge in livestock. The possibility of an indirect FMD vaccine potency test based on a serological alternative was initially investigated for a lead vaccine candidate, Adt.A24. Results show that serum virus neutralization (SVN) based serology testing for Adt.A24 vaccine lot release is not feasible, at least not in the context of vaccine potency assessment at one week post-vaccination. Thus, an in vitro infectious titer assay (tissue culture infectious dose 50, TCID50) which measures FMD infectious (protein expression) titer was established. Pre-validation results show acceptable assay variability and linearity and these data support further studies to validate the TCID50 assay as a potential potency release test. In addition, a quantitative physiochemical assay (HPLC) and three immunochemical assays (Fluorescent Focus-Forming Unit (FFU); tissue culture expression dose 50 (TCED50); Western blot) were developed for potential use as in vitro assays to monitor AdFMD vaccine lot-to-lot consistency and other potential applications. These results demonstrate the feasibility of using a traditional modified-live vaccine virus infectivity assay in combination with a set of physiochemical and immunochemical tests to build a vaccine product profile that will ensure the each Ad

  12. Complex adenovirus-vectored vaccine protects guinea pigs from three strains of Marburg virus challenges

    SciTech Connect

    Wang Danher; Hevey, Michael; Juompan, Laure Y.; Trubey, Charles M.; Raja, Nicholas U.; Deitz, Stephen B.; Woraratanadharm, Jan; Luo Min; Yu Hong; Swain, Benjamin M.; Moore, Kevin M.; Dong, John Y. . E-mail: dongj@genphar.com

    2006-09-30

    The Marburg virus (MARV), an African filovirus closely related to the Ebola virus, causes a deadly hemorrhagic fever in humans, with up to 90% mortality. Currently, treatment of disease is only supportive, and no vaccines are available to prevent spread of MARV infections. In order to address this need, we have developed and characterized a novel recombinant vaccine that utilizes a single complex adenovirus-vectored vaccine (cAdVax) to overexpress a MARV glycoprotein (GP) fusion protein derived from the Musoke and Ci67 strains of MARV. Vaccination with the cAdVaxM(fus) vaccine led to efficient production of MARV-specific antibodies in both mice and guinea pigs. Significantly, guinea pigs vaccinated with at least 5 x 10{sup 7} pfu of cAdVaxM(fus) vaccine were 100% protected against lethal challenges by the Musoke, Ci67 and Ravn strains of MARV, making it a vaccine with trivalent protective efficacy. Therefore, the cAdVaxM(fus) vaccine serves as a promising vaccine candidate to prevent and contain multi-strain infections by MARV.

  13. Vaccinia viruses: vaccines against smallpox and vectors against infectious diseases and tumors

    PubMed Central

    Walsh, Stephen R; Dolin, Raphael

    2011-01-01

    Less than 200 years after its introduction, widespread use of vaccinia virus (VACV) as a smallpox vaccine has eradicated variola virus. Along with the remarkable success of the vaccination program, frequent and sometimes severe adverse reactions to VACV were encountered. After eradication, VACV has been reserved for select populations who might be at significant risk for orthopoxvirus infections. Events over the past decade have renewed concerns over the potential use of variola virus as a biological weapon. Accordingly, interest in VACV and attenuated derivatives has increased, both as vaccines against smallpox and as vectors for other vaccines. This article will focus on new developments in the field of orthopoxvirus immunization and will highlight recent advances in the use of vaccinia viruses as vectors for infectious diseases and malignancies. PMID:21854314

  14. Newcastle disease virus as a vaccine vector for infectious laryngotracheitis

    USDA-ARS?s Scientific Manuscript database

    Effective, safe, and incapable of reverting to virulence are characteristics desirable for infectious laryngotracheitis virus (ILTV) vaccines. Recombinant Newcastle disease virus (NDV) expressing foreign antigens of avian and mammalian pathogens have been demonstrated to elicit protective immunity....

  15. Immunogenicity and efficacy of a chimpanzee adenovirus-vectored Rift Valley Fever vaccine in mice

    PubMed Central

    2013-01-01

    Background Rift Valley Fever (RVF) is a viral zoonosis that historically affects livestock production and human health in sub-Saharan Africa, though epizootics have also occurred in the Arabian Peninsula. Whilst an effective live-attenuated vaccine is available for livestock, there is currently no licensed human RVF vaccine. Replication-deficient chimpanzee adenovirus (ChAd) vectors are an ideal platform for development of a human RVF vaccine, given the low prevalence of neutralizing antibodies against them in the human population, and their excellent safety and immunogenicity profile in human clinical trials of vaccines against a wide range of pathogens. Methods Here, in BALB/c mice, we evaluated the immunogenicity and efficacy of a replication-deficient chimpanzee adenovirus vector, ChAdOx1, encoding the RVF virus envelope glycoproteins, Gn and Gc, which are targets of virus neutralizing antibodies. The ChAdOx1-GnGc vaccine was assessed in comparison to a replication-deficient human adenovirus type 5 vector encoding Gn and Gc (HAdV5-GnGc), a strategy previously shown to confer protective immunity against RVF in mice. Results A single immunization with either of the vaccines conferred protection against RVF virus challenge eight weeks post-immunization. Both vaccines elicited RVF virus neutralizing antibody and a robust CD8+ T cell response. Conclusions Together the results support further development of RVF vaccines based on replication-deficient adenovirus vectors, with ChAdOx1-GnGc being a potential candidate for use in future human clinical trials. PMID:24304565

  16. Immunogenicity and efficacy of a chimpanzee adenovirus-vectored Rift Valley fever vaccine in mice.

    PubMed

    Warimwe, George M; Lorenzo, Gema; Lopez-Gil, Elena; Reyes-Sandoval, Arturo; Cottingham, Matthew G; Spencer, Alexandra J; Collins, Katharine A; Dicks, Matthew D J; Milicic, Anita; Lall, Amar; Furze, Julie; Turner, Alison V; Hill, Adrian V S; Brun, Alejandro; Gilbert, Sarah C

    2013-12-05

    Rift Valley Fever (RVF) is a viral zoonosis that historically affects livestock production and human health in sub-Saharan Africa, though epizootics have also occurred in the Arabian Peninsula. Whilst an effective live-attenuated vaccine is available for livestock, there is currently no licensed human RVF vaccine. Replication-deficient chimpanzee adenovirus (ChAd) vectors are an ideal platform for development of a human RVF vaccine, given the low prevalence of neutralizing antibodies against them in the human population, and their excellent safety and immunogenicity profile in human clinical trials of vaccines against a wide range of pathogens. Here, in BALB/c mice, we evaluated the immunogenicity and efficacy of a replication-deficient chimpanzee adenovirus vector, ChAdOx1, encoding the RVF virus envelope glycoproteins, Gn and Gc, which are targets of virus neutralizing antibodies. The ChAdOx1-GnGc vaccine was assessed in comparison to a replication-deficient human adenovirus type 5 vector encoding Gn and Gc (HAdV5-GnGc), a strategy previously shown to confer protective immunity against RVF in mice. A single immunization with either of the vaccines conferred protection against RVF virus challenge eight weeks post-immunization. Both vaccines elicited RVF virus neutralizing antibody and a robust CD8+ T cell response. Together the results support further development of RVF vaccines based on replication-deficient adenovirus vectors, with ChAdOx1-GnGc being a potential candidate for use in future human clinical trials.

  17. Viral vector vaccines protect cockatiels from inflammatory lesions after heterologous parrot bornavirus 2 challenge infection.

    PubMed

    Runge, Solveig; Olbert, Marita; Herden, Christiane; Malberg, Sara; Römer-Oberdörfer, Angela; Staeheli, Peter; Rubbenstroth, Dennis

    2017-01-23

    Avian bornaviruses are causative agents of proventricular dilatation disease (PDD), a chronic neurologic and often fatal disorder of psittacines including endangered species. To date no causative therapy or immunoprophylaxis is available. Our previous work has shown that viral vector vaccines can delay the course of homologous bornavirus challenge infections but failed to protect against PDD when persistent infection was not prevented. The goal of this study was to refine our avian bornavirus vaccination and infection model to better represent natural bornavirus infections in order to achieve full protection against a heterologous challenge infection. We observed that parrot bornavirus 2 (PaBV-2) readily infected cockatiels (Nymphicus hollandicus) by combined intramuscular and subcutaneous injection with as little as 10(2.7)foci-forming units (ffu) per bird, whereas a 500-fold higher dose of the same virus administered via peroral and oculonasal route did not result in persistent infection. These results indicated that experimental bornavirus challenge infections with this virus should be performed via the parenteral route. Prime-boost vaccination of cockatiels with Newcastle disease virus (NDV) and modified vaccinia virus Ankara (MVA) vectors expressing the nucleoprotein and phosphoprotein genes of PaBV-4 substantially blocked bornavirus replication following parenteral challenge infection with 10(3.5)ffu of heterologous PaBV-2. Only two out of six vaccinated birds had very low viral levels detectable in a few organs. As a consequence, only one vaccinated bird developed mild PDD-associated microscopic lesions, while mock-vaccinated controls were not protected against PaBV-2 infection and inflammation. Our results demonstrate that NDV and MVA vector vaccines can protect against invasive heterologous bornavirus challenge infections and subsequent PDD. These vector vaccines represent a promising tool to combat avian bornaviruses in psittacine populations. Copyright

  18. Protection of Chickens against Avian Influenza with Non-Replicating Adenovirus-Vectored Vaccine

    PubMed Central

    Toro, Haroldo; Tang, De-chu C.; Suarez, David L.; Shi, Z.

    2009-01-01

    Protective immunity against avian influenza (AI) virus was elicited in chickens by single-dose vaccination with a replication competent adenovirus (RCA) -free human adenovirus (Ad) vector encoding an H7 AI hemagglutinin (AdChNY94.H7). Chickens vaccinated in ovo with an Ad vector encoding an AI H5 (AdTW68.H5) previously described, which were subsequently vaccinated intramuscularly with AdChNY94.H7 post-hatch, responded with robust antibody titers against both the H5 and H7 AI proteins. Antibody responses to Ad vector in ovo vaccination follow a dose-response kinetic. The use of a synthetic AI H5 gene codon optimized to match the chicken cell tRNA pool was more potent than the cognate H5 gene. The use of Ad-vectored vaccines to increase resistance of chicken populations against multiple AI strains could reduce the risk of an avian-originating influenza pandemic in humans. PMID:18384919

  19. Vector Saliva in Vaccines for Visceral Leishmaniasis: A Brief Encounter of High Consequence?

    PubMed Central

    Kamhawi, Shaden; Aslan, Hamide; Valenzuela, Jesus G.

    2014-01-01

    Visceral leishmaniasis (VL) is a vector-borne disease transmitted by phlebotomine sand flies and remains the most serious form of the disease with no available human vaccine. Repeatedly, studies have demonstrated the immunogenicity and protective efficacy of a number of sand fly salivary proteins against cutaneous and visceral leishmaniasis. All Leishmania species including agents of VL are co-deposited into the skin together with vector saliva. Generally, the immune response to a protective salivary protein in vaccinated animals is rapid and possibly acts on the parasites soon after delivery into the skin by the bite of an infective sand fly. This is followed by the development of a stronger Leishmania-specific immunity in saliva-vaccinated animals compared to controls. Considering that several of the most efficacious protective molecules were identified from a proven vector of VL, we put forward the notion that a combination vaccine that includes a Leishmania antigen and a vector salivary protein has the potential to improve vaccine efficacy by targeting the parasite at it most vulnerable stage just after transmission. PMID:25152872

  20. Design of vaccination and fumigation on Host-Vector Model by input-output linearization method

    NASA Astrophysics Data System (ADS)

    Nugraha, Edwin Setiawan; Naiborhu, Janson; Nuraini, Nuning

    2017-03-01

    Here, we analyze the Host-Vector Model and proposed design of vaccination and fumigation to control infectious population by using feedback control especially input-output liniearization method. Host population is divided into three compartments: susceptible, infectious and recovery. Whereas the vector population is divided into two compartment such as susceptible and infectious. In this system, vaccination and fumigation treat as input factors and infectious population as output result. The objective of design is to stabilize of the output asymptotically tend to zero. We also present the examples to illustrate the design model.

  1. Construction and Application of Newcastle Disease Virus-Based Vector Vaccines.

    PubMed

    Wichgers Schreur, Paul J

    2016-01-01

    Paramyxoviruses are able to stably express a wide-variety of heterologous antigens at relatively high levels in various species and are consequently considered as potent gene delivery vehicles. A single vaccination is frequently sufficient for the induction of robust humoral and cellular immune responses. Here we provide detailed methods for the construction and application of Newcastle disease virus (NDV)-based vector vaccines. The in silico design and in vitro rescue as well as the in vivo evaluation of NDV based vectors are described in this chapter.

  2. Biosafety considerations for attenuated measles virus vectors used in virotherapy and vaccination

    PubMed Central

    Baldo, Aline; Galanis, Evanthia; Tangy, Frédéric; Herman, Philippe

    2016-01-01

    ABSTRACT Attenuated measles virus (MV) is one of the most effective and safe vaccines available, making it attractive candidate vector to prevent infectious diseases. Attenuated MV have acquired the ability to use the complement regulator CD46 as a major receptor to mediate virus entry and intercellular fusion. Therefore, attenuated MV strains preferentially infect and destroy a wide variety of cancer cells making them also attractive oncolytic vectors. The use of recombinant MV vector has to comply with various regulatory requirements, particularly relating to the assessment of potential risks for human health and the environment. The present article highlights the main characteristics of MV and recombinant MV vectors used for vaccination and virotherapy and discusses these features from a biosafety point of view. PMID:26631840

  3. Attenuated and vectored vaccines protect nonhuman primates against Chikungunya virus

    PubMed Central

    Ljungberg, Karl; Kümmerer, Beate M.; Gosse, Leslie; Dereuddre-Bosquet, Nathalie; Tchitchek, Nicolas; Hallengärd, David; García-Arriaza, Juan; Meinke, Andreas; Esteban, Mariano; Merits, Andres

    2017-01-01

    Chikungunya virus (CHIKV) is rapidly spreading across the globe, and millions are infected. Morbidity due to this virus is a serious threat to public health, but at present, there is no vaccine against this debilitating disease. We have recently developed a number of vaccine candidates, and here we have evaluated 3 of them in a nonhuman primate model. A single immunization with an attenuated strain of CHIKV (Δ5nsP3), a homologous prime-boost immunization with a DNA-launched RNA replicon encoding CHIKV envelope proteins (DREP-E), and a DREP-E prime followed by a recombinant modified vaccinia virus Ankara encoding CHIKV capsid and envelope (MVA-CE) boost all induced protection against WT CHIKV infection. The attenuated Δ5nsP3 virus proved to be safe and did not show any clinical signs typically associated with WT CHIKV infections such as fever, skin rash, lymphopenia, or joint swelling. These vaccines are based on an East/Central/South African strain of Indian Ocean lineage, but they also generated neutralizing antibodies against an isolate of the Asian genotype that now is rapidly spreading across the Americas. These results form the basis for clinical development of an efficacious CHIKV vaccine that generates both humoral and cellular immunity with long-term immunological memory. PMID:28352649

  4. Immunogenicity of next-generation HPV vaccines in non-human primates: Measles-vectored HPV vaccine versus Pichia pastoris recombinant protein vaccine.

    PubMed

    Gupta, Gaurav; Giannino, Viviana; Rishi, Narayan; Glueck, Reinhard

    2016-09-07

    Human papillomavirus (HPV) infection is the most common sexually transmitted disease worldwide. HPVs are oncogenic small double-stranded DNA viruses that are the primary causal agent of cervical cancer and other types of cancers, including in the anus, oropharynx, vagina, vulva, and penis. Prophylactic vaccination against HPV is an attractive strategy for preventing cervical cancer and some other types of cancers. However, there are few safe and effective vaccines against HPV infections. Current first-generation commercial HPV vaccines are expensive to produce and deliver. The goal of this study was to develop an alternate potent HPV recombinant L1-based vaccines by producing HPV virus-like particles into a vaccine that is currently used worldwide. Live attenuated measles virus (MV) vaccines have a well-established safety and efficacy record, and recombinant MV (rMV) produced by reverse genetics may be useful for generating candidate HPV vaccines to meet the needs of the developing world. We studied in non-human primate rMV-vectored HPV vaccine in parallel with a classical alum adjuvant recombinant HPV16L1 and 18L1 protein vaccine produced in Pichia pastoris. A combined prime-boost approach using both vaccines was evaluated, as well as immune interference due to pre-existing immunity against the MV. The humoral immune response induced by the MV, Pichia-expressed vaccine, and their combination as priming and boosting approaches was found to elicit HPV16L1 and 18L1 specific total IgG and neutralizing antibody titres. Pre-existing antibodies against measles did not prevent the immune response against HPV16L1 and 18L1. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Oral vaccination against mycoplasmal pneumonia of swine using a live Erysipelothrix rhusiopathiae vaccine strain as a vector.

    PubMed

    Ogawa, Yohsuke; Oishi, Eiji; Muneta, Yoshihiro; Sano, Akiyuki; Hikono, Hirokazu; Shibahara, Tomoyuki; Yagi, Yukio; Shimoji, Yoshihiro

    2009-07-16

    Erysipelothrix rhusiopathiae Koganei 65-0.15 strain, the live swine erysipelas vaccine for subcutaneous injection, has been shown to colonize the tonsils of pigs after oral inoculation. We thus evaluated the possible use of the strain as a vector for oral vaccination against mycoplasmal pneumonia of swine. Recombinant E. rhusiopathiae strains expressing the C-terminal domain of the P97 adhesin of Mycoplasma hyopneumoniae were constructed and examined for vaccine efficacy in mice and pigs. Mice subcutaneously inoculated with the recombinant strains were protected from challenge exposure to a virulent E. rhusiopathiae. Administration of milk replacer containing recombinant E. rhusiopathiae expressing the M. hyopneumoniae protein protected pigs from death after exposure to E. rhusiopathiae and significantly reduced the severity of pneumonic lung lesions caused by infection with M. hyopneumoniae.

  6. Sequence and immunogenicity of a clinically approved novel measles virus vaccine vector.

    PubMed

    Zuniga, Amando; Liniger, Mathias; Morin, Teldja Neige Azzouz; Marty, René R; Wiegand, Marian; Ilter, Orhan; Weibel, Sara; Billeter, Martin A; Knuchel, Marlyse C; Naim, Hussein Y

    2013-03-01

    The measles virus vaccine (MVbv) is a clinically certified and well-tolerated vaccine strain that has been given both parenterally and mucosally. It has been extensively used in children and has proven to be safe and effective in eliciting protective immunity. This specific strain was therefore chosen to generate a measles viral vector. The genome of the commercial MVbv vaccine strain was isolated, sequenced and a plasmid, p(+)MVb, enabling transcription of the viral antigenome and rescue of MVb, was constructed. Phylogenic and phenotypic analysis revealed that MVbv and the rescued MVb constitute another evolutionary branch within the hitherto classified measles vaccines. Plasmid p(+)MVb was modified by insertion of artificial MV-type transcription units (ATUs) for the generation of recombinant viruses (rMVb) expressing additional proteins. Replication characteristics and immunogenicity of rMVb vectors were similar to the parental MVbv and to other vaccine strains. The expression of the additional proteins was stable over 10 serial virus transfers, which corresponds to an amplification greater than 10 ( 20) . The excellent safety record and its efficient application as aerosol may add to the usefulness of the derived vectors.

  7. General considerations on the biosafety of virus-derived vectors used in gene therapy and vaccination.

    PubMed

    Baldo, Aline; van den Akker, Eric; Bergmans, Hans E; Lim, Filip; Pauwels, Katia

    2013-12-01

    This introductory paper gathers general considerations on the biosafety of virus-derived vectors that are used in human gene therapy and/or vaccination. The importance to assess the potential risks for human health and the environment related to the use of genetically modified organisms (GMO) in this case genetically modified viral vectors is highlighted by several examples. This environmental risk assessment is one of the requirements within the European regulatory framework covering the conduct of clinical trials using GMO. Risk assessment methodologies for the environmental risk assessment of genetically modified virus-derived vectors have been developed.

  8. General Considerations on the Biosafety of Virus-derived Vectors Used in Gene Therapy and Vaccination

    PubMed Central

    Baldo, Aline; van den Akker, Eric; Bergmans, Hans E.; Lim, Filip; Pauwels, Katia

    2013-01-01

    This introductory paper gathers general considerations on the biosafety of virus-derived vectors that are used in human gene therapy and/or vaccination. The importance to assess the potential risks for human health and the environment related to the use of genetically modified organisms (GMO) in this case genetically modified viral vectors is highlighted by several examples. This environmental risk assessment is one of the requirements within the European regulatory framework covering the conduct of clinical trials using GMO. Risk assessment methodologies for the environmental risk assessment of genetically modified virus-derived vectors have been developed. PMID:24195604

  9. An economic evaluation of vector control in the age of a dengue vaccine

    PubMed Central

    Haines, Alexander; Bangert, Mathieu; Farlow, Andrew; Hemingway, Janet; Velayudhan, Raman

    2017-01-01

    Introduction Dengue is a rapidly emerging vector-borne Neglected Tropical Disease, with a 30-fold increase in the number of cases reported since 1960. The economic cost of the illness is measured in the billions of dollars annually. Environmental change and unplanned urbanization are conspiring to raise the health and economic cost even further beyond the reach of health systems and households. The health-sector response has depended in large part on control of the Aedes aegypti and Ae. albopictus (mosquito) vectors. The cost-effectiveness of the first-ever dengue vaccine remains to be evaluated in the field. In this paper, we examine how it might affect the cost-effectiveness of sustained vector control. Methods We employ a dynamic Markov model of the effects of vector control on dengue in both vectors and humans over a 15-year period, in six countries: Brazil, Columbia, Malaysia, Mexico, the Philippines, and Thailand. We evaluate the cost (direct medical costs and control programme costs) and cost-effectiveness of sustained vector control, outbreak response and/or medical case management, in the presence of a (hypothetical) highly targeted and low cost immunization strategy using a (non-hypothetical) medium-efficacy vaccine. Results Sustained vector control using existing technologies would cost little more than outbreak response, given the associated costs of medical case management. If sustained use of existing or upcoming technologies (of similar price) reduce vector populations by 70–90%, the cost per disability-adjusted life year averted is 2013 US$ 679–1331 (best estimates) relative to no intervention. Sustained vector control could be highly cost-effective even with less effective technologies (50–70% reduction in vector populations) and in the presence of a highly targeted and low cost immunization strategy using a medium-efficacy vaccine. Discussion Economic evaluation of the first-ever dengue vaccine is ongoing. However, even under very optimistic

  10. An economic evaluation of vector control in the age of a dengue vaccine.

    PubMed

    Fitzpatrick, Christopher; Haines, Alexander; Bangert, Mathieu; Farlow, Andrew; Hemingway, Janet; Velayudhan, Raman

    2017-08-01

    Dengue is a rapidly emerging vector-borne Neglected Tropical Disease, with a 30-fold increase in the number of cases reported since 1960. The economic cost of the illness is measured in the billions of dollars annually. Environmental change and unplanned urbanization are conspiring to raise the health and economic cost even further beyond the reach of health systems and households. The health-sector response has depended in large part on control of the Aedes aegypti and Ae. albopictus (mosquito) vectors. The cost-effectiveness of the first-ever dengue vaccine remains to be evaluated in the field. In this paper, we examine how it might affect the cost-effectiveness of sustained vector control. We employ a dynamic Markov model of the effects of vector control on dengue in both vectors and humans over a 15-year period, in six countries: Brazil, Columbia, Malaysia, Mexico, the Philippines, and Thailand. We evaluate the cost (direct medical costs and control programme costs) and cost-effectiveness of sustained vector control, outbreak response and/or medical case management, in the presence of a (hypothetical) highly targeted and low cost immunization strategy using a (non-hypothetical) medium-efficacy vaccine. Sustained vector control using existing technologies would cost little more than outbreak response, given the associated costs of medical case management. If sustained use of existing or upcoming technologies (of similar price) reduce vector populations by 70-90%, the cost per disability-adjusted life year averted is 2013 US$ 679-1331 (best estimates) relative to no intervention. Sustained vector control could be highly cost-effective even with less effective technologies (50-70% reduction in vector populations) and in the presence of a highly targeted and low cost immunization strategy using a medium-efficacy vaccine. Economic evaluation of the first-ever dengue vaccine is ongoing. However, even under very optimistic assumptions about a highly targeted and low

  11. Keynote symposium - avian influenza: Vectors, vaccines, public health, and product marketability introduction and welcome

    USDA-ARS?s Scientific Manuscript database

    This paper is the introduction to the Keynote Symposium titled “Avian Influenza: Vectors, Vaccines, Public Health, and Product Marketability” that the author organized for the Poultry Science Association (PSA) on July 20, 2008. The purpose of the symposium was to provide the members and guests of PS...

  12. DNA Virus Vectors for Vaccine Production in Plants: Spotlight on Geminiviruses

    PubMed Central

    Hefferon, Kathleen L.

    2014-01-01

    Plants represent a safe, efficacious and inexpensive production platform by which to provide vaccines and other therapeutic proteins to the world’s poor. Plant virus expression vector technology has rapidly become one of the most popular methods to express pharmaceutical proteins in plants. This review discusses several of the state-of-the-art plant expression systems based upon geminiviruses that have been engineered for vaccine production. An overview of the advantages of these small, single-stranded DNA viruses is provided and comparisons are made with other virus expression systems. Advances in the design of several different geminivirus vectors are presented in this review, and examples of vaccines and other biologics generated from each are described. PMID:26344750

  13. Infectivity of attenuated poxvirus vaccine vectors and immunogenicity of a raccoonpox vectored rabies vaccine in the Brazilian Free-tailed bat (Tadarida brasiliensis).

    PubMed

    Stading, Ben R; Osorio, Jorge E; Velasco-Villa, Andres; Smotherman, Michael; Kingstad-Bakke, Brock; Rocke, Tonie E

    2016-10-17

    Bats (Order Chiroptera) are an abundant group of mammals with tremendous ecological value as insectivores and plant dispersers, but their role as reservoirs of zoonotic diseases has received more attention in the last decade. With the goal of managing disease in free-ranging bats, we tested modified vaccinia Ankara (MVA) and raccoon poxvirus (RCN) as potential vaccine vectors in the Brazilian Free-tailed bat (Tadarida brasiliensis), using biophotonic in vivo imaging and immunogenicity studies. Animals were administered recombinant poxviral vectors expressing the luciferase gene (MVA-luc, RCN-luc) through oronasal (ON) or intramuscular (IM) routes and subsequently monitored for bioluminescent signal indicative of viral infection. No clinical illness was noted after exposure to any of the vectors, and limited luciferase expression was observed. Higher and longer levels of expression were observed with the RCN-luc construct. When given IM, luciferase expression was limited to the site of injection, while ON exposure led to initial expression in the oral cavity, often followed by secondary replication at another location, likely the gastric mucosa or gastric associated lymphatic tissue. Viral DNA was detected in oral swabs up to 7 and 9 days post infection (dpi) for MVA and RCN, respectively. While no live virus was detected in oral swabs from MVA-infected bats, titers up to 3.88 x 10(4) PFU/ml were recovered from oral swabs of RCN-infected bats. Viral DNA was also detected in fecal samples from two bats inoculated IM with RCN, but no live virus was recovered. Finally, we examined the immunogenicity of a RCN based rabies vaccine (RCN-G) following ON administration. Significant rabies neutralizing antibody titers were detected in the serum of immunized bats using the rapid fluorescence focus inhibition test (RFFIT). These studies highlight the safety and immunogenicity of attenuated poxviruses and their potential use as vaccine vectors in bats.

  14. Infectivity of attenuated poxvirus vaccine vectors and immunogenicity of a raccoonpox vectored rabies vaccine in the Brazilian Free-tailed bat (Tadarida brasiliensis)

    USGS Publications Warehouse

    Stading, Benjamin; Osorio, Jorge E.; Velasco-Villa, Andres; Smotherman, Michael; Kingstad-Bakke, Brock; Rocke, Tonie E.

    2016-01-01

    Bats (Order Chiroptera) are an abundant group of mammals with tremendous ecological value as insectivores and plant dispersers, but their role as reservoirs of zoonotic diseases has received more attention in the last decade. With the goal of managing disease in free-ranging bats, we tested modified vaccinia Ankara (MVA) and raccoon poxvirus (RCN) as potential vaccine vectors in the Brazilian Free-tailed bat (Tadarida brasiliensis), using biophotonic in vivo imaging and immunogenicity studies. Animals were administered recombinant poxviral vectors expressing the luciferase gene (MVA-luc, RCN-luc) through oronasal (ON) or intramuscular (IM) routes and subsequently monitored for bioluminescent signal indicative of viral infection. No clinical illness was noted after exposure to any of the vectors, and limited luciferase expression was observed. Higher and longer levels of expression were observed with the RCN-luc construct. When given IM, luciferase expression was limited to the site of injection, while ON exposure led to initial expression in the oral cavity, often followed by secondary replication at another location, likely the gastric mucosa or gastric associated lymphatic tissue. Viral DNA was detected in oral swabs up to 7 and 9 days post infection (dpi) for MVA and RCN, respectively. While no live virus was detected in oral swabs from MVA-infected bats, titers up to 3.88 x 104 PFU/ml were recovered from oral swabs of RCN-infected bats. Viral DNA was also detected in fecal samples from two bats inoculated IM with RCN, but no live virus was recovered. Finally, we examined the immunogenicity of a RCN based rabies vaccine (RCN-G) following ON administration. Significant rabies neutralizing antibody titers were detected in the serum of immunized bats using the rapid fluorescence focus inhibition test (RFFIT). These studies highlight the safety and immunogenicity of attenuated poxviruses and their potential use as vaccine vectors in bats.

  15. In situ pneumococcal vaccine production and delivery through a hybrid biological-biomaterial vector

    PubMed Central

    Li, Yi; Beitelshees, Marie; Fang, Lei; Hill, Andrew; Ahmadi, Mahmoud Kamal; Chen, Mingfu; Davidson, Bruce A.; Knight, Paul; Smith, Randall J.; Andreadis, Stelios T.; Hakansson, Anders P.; Jones, Charles H.; Pfeifer, Blaine A.

    2016-01-01

    The type and potency of an immune response provoked during vaccination will determine ultimate success in disease prevention. The basis for this response will be the design and implementation of antigen presentation to the immune system. Whereas direct antigen administration will elicit some form of immunological response, a more sophisticated approach would couple the antigen of interest to a vector capable of broad delivery formats and designed for heightened response. New antigens associated with pneumococcal disease virulence were used to test the delivery and adjuvant capabilities of a hybrid biological-biomaterial vector consisting of a bacterial core electrostatically coated with a cationic polymer. The hybrid design provides (i) passive and active targeting of antigen-presenting cells, (ii) natural and multicomponent adjuvant properties, (iii) dual intracellular delivery mechanisms, and (iv) a simple formulation mechanism. In addition, the hybrid format enables device-specific, or in situ, antigen production and consolidation via localization within the bacterial component of the vector. This capability eliminates the need for dedicated antigen production and purification before vaccination efforts while leveraging the aforementioned features of the overall delivery device. We present the first disease-specific utilization of the vector toward pneumococcal disease highlighted by improved immune responses and protective capabilities when tested against traditional vaccine formulations and a range of clinically relevant Streptococcus pneumoniae strains. More broadly, the results point to similar levels of success with other diseases that would benefit from the production, delivery, and efficacy capabilities offered by the hybrid vector. PMID:27419235

  16. Progress with viral vectored malaria vaccines: A multi-stage approach involving "unnatural immunity".

    PubMed

    Ewer, Katie J; Sierra-Davidson, Kailan; Salman, Ahmed M; Illingworth, Joseph J; Draper, Simon J; Biswas, Sumi; Hill, Adrian V S

    2015-12-22

    Viral vectors used in heterologous prime-boost regimens are one of very few vaccination approaches that have yielded significant protection against controlled human malaria infections. Recently, protection induced by chimpanzee adenovirus priming and modified vaccinia Ankara boosting using the ME-TRAP insert has been correlated with the induction of potent CD8(+) T cell responses. This regimen has progressed to field studies where efficacy against infection has now been reported. The same vectors have been used pre-clinically to identify preferred protective antigens for use in vaccines against the pre-erythrocytic, blood-stage and mosquito stages of malaria and this work is reviewed here for the first time. Such antigen screening has led to the prioritization of the PfRH5 blood-stage antigen, which showed efficacy against heterologous strain challenge in non-human primates, and vectors encoding this antigen are in clinical trials. This, along with the high transmission-blocking activity of some sexual-stage antigens, illustrates well the capacity of such vectors to induce high titre protective antibodies in addition to potent T cell responses. All of the protective responses induced by these vectors exceed the levels of the same immune responses induced by natural exposure supporting the view that, for subunit vaccines to achieve even partial efficacy in humans, "unnatural immunity" comprising immune responses of very high magnitude will need to be induced.

  17. Interleukin-Encoding Adenoviral Vectors as Genetic Adjuvant for Vaccination against Retroviral Infection

    PubMed Central

    Ohs, Inga; Windmann, Sonja; Wildner, Oliver; Dittmer, Ulf; Bayer, Wibke

    2013-01-01

    Interleukins (IL) are cytokines with stimulatory and modulatory functions in the immune system. In this study, we have chosen interleukins which are involved in the enhancement of TH2 responses and B cell functions to analyze their potential to improve a prophylactic adenovirus-based anti-retroviral vaccine with regard to antibody and virus-specific CD4+ T cell responses. Mice were vaccinated with an adenoviral vector which encodes and displays the Friend Virus (FV) surface envelope protein gp70 (Ad.pIXgp70) in combination with adenoviral vectors encoding the interleukins IL4, IL5, IL6, IL7 or IL23. Co-application of Ad.pIXgp70 with Ad.IL5, Ad.IL6 or Ad.IL23 resulted in improved protection with high control over FV-induced splenomegaly and reduced viral loads. Mice co-immunized with adenoviral vectors encoding IL5 or IL23 showed increased neutralizing antibody responses while mice co-immunized with Ad.IL6 or Ad.IL23 showed improved FV-specific CD4+ T cell responses compared to mice immunized with Ad.pIXgp70 alone. We show that the co-application of adenoviral vectors encoding specific interleukins is suitable to improve the vaccination efficacy of an anti-retroviral vaccine. Improved protection correlated with improved CD4+ T cell responses and especially with higher neutralizing antibody titers. The co-application of selected interleukin-encoding adenoviral vectors is a valuable tool for vaccination with regard to enhancement of antibody mediated immunity. PMID:24349306

  18. Interleukin-encoding adenoviral vectors as genetic adjuvant for vaccination against retroviral infection.

    PubMed

    Ohs, Inga; Windmann, Sonja; Wildner, Oliver; Dittmer, Ulf; Bayer, Wibke

    2013-01-01

    Interleukins (IL) are cytokines with stimulatory and modulatory functions in the immune system. In this study, we have chosen interleukins which are involved in the enhancement of TH2 responses and B cell functions to analyze their potential to improve a prophylactic adenovirus-based anti-retroviral vaccine with regard to antibody and virus-specific CD4(+) T cell responses. Mice were vaccinated with an adenoviral vector which encodes and displays the Friend Virus (FV) surface envelope protein gp70 (Ad.pIXgp70) in combination with adenoviral vectors encoding the interleukins IL4, IL5, IL6, IL7 or IL23. Co-application of Ad.pIXgp70 with Ad.IL5, Ad.IL6 or Ad.IL23 resulted in improved protection with high control over FV-induced splenomegaly and reduced viral loads. Mice co-immunized with adenoviral vectors encoding IL5 or IL23 showed increased neutralizing antibody responses while mice co-immunized with Ad.IL6 or Ad.IL23 showed improved FV-specific CD4(+) T cell responses compared to mice immunized with Ad.pIXgp70 alone. We show that the co-application of adenoviral vectors encoding specific interleukins is suitable to improve the vaccination efficacy of an anti-retroviral vaccine. Improved protection correlated with improved CD4(+) T cell responses and especially with higher neutralizing antibody titers. The co-application of selected interleukin-encoding adenoviral vectors is a valuable tool for vaccination with regard to enhancement of antibody mediated immunity.

  19. Bovine herpesvirus 4-based vector delivering a hybrid rat/human HER-2 oncoantigen efficiently protects mice from autochthonous Her-2+ mammary cancer

    PubMed Central

    Jacca, Sarah; Rolih, Valeria; Quaglino, Elena; Franceschi, Valentina; Tebaldi, Giulia; Bolli, Elisabetta; Rosamilia, Alfonso; Ottonello, Simone; Cavallo, Federica; Donofrio, Gaetano

    2016-01-01

    ABSTRACT The epidermal growth factor receptor 2 (HER-2) oncogene is a major target for the immunotherapy of breast cancer. Following up to the therapeutic success achieved with Her-2-targeting monoclonal antibodies, immune-prophylactic approaches directed against Her-2 have also been investigated taking into account, and trying to overcome, Her-2 self-tolerance. Perhaps due to safety (and efficacy) concerns, the least explored anti-Her-2 active immunization strategy so far has been the one relying on viral-vectored vaccine formulations. Taking advantage of the favorable properties of bovine herpesvirus 4 (BoHV-4) in terms of safety and ease of manipulation as well as its previously documented ability to transduce and confer immunogenicity to heterologous antigens, we tested the ability of different recombinant HER-2-BoHV-4 immunogens to 8break tolerance and elicit a protective, anti-mammary tumor antibody response in HER-2 transgenic BALB-neuT mice. All the tested constructs expressed the HER-2 transgenes at high levels and elicited significant cellular immune responses in BALB/c mice upon administration via either DNA vaccination or viral infection. In BALB-neuT mice, instead, only the viral construct expressing the membrane-bound chimeric form of Her-2 protein (BoHV-4-RHuT-gD) elicited a humoral immune response that was more intense and earlier-appearing than that induced by DNA vaccination. In keeping with this observation, two administrations of BoHV-4-RHuT-gD effectively protected BALB-neuT mice from tumor formation, with 50% of vaccinated animals tumor-free after 30 weeks from immunization compared to 100% of animals exhibiting at least one palpable tumor in the case of animals vaccinated with the other BoHV-4-HER-2 constructs. PMID:27141335

  20. Skin vaccination with live virus vectored microneedle arrays induce long lived CD8(+) T cell memory.

    PubMed

    Becker, Pablo D; Hervouet, Catherine; Mason, Gavin M; Kwon, Sung-Yun; Klavinskis, Linda S

    2015-09-08

    A simple dissolvable microneedle array (MA) platform has emerged as a promising technology for vaccine delivery, due to needle-free injection with a formulation that preserves the immunogenicity of live viral vectored vaccines dried in the MA matrix. While recent studies have focused largely on design parameters optimized to induce primary CD8(+) T cell responses, the hallmark of a vaccine is synonymous with engendering long-lasting memory. Here, we address the capacity of dried MA vaccination to programme phenotypic markers indicative of effector/memory CD8(+) T cell subsets and also responsiveness to recall antigen benchmarked against conventional intradermal (ID) injection. We show that despite a slightly lower frequency of dividing T cell receptor transgenic CD8(+) T cells in secondary lymphoid tissue at an early time point, the absolute number of CD8(+) T cells expressing an effector memory (CD62L(-)CD127(+)) and central memory (CD62L(+)CD127(+)) phenotype during peak expansion were comparable after MA and ID vaccination with a recombinant human adenovirus type 5 vector (AdHu5) encoding HIV-1 gag. Similarly, both vaccination routes generated CD8(+) memory T cell subsets detected in draining LNs for at least two years post-vaccination capable of responding to secondary antigen. These data suggest that CD8(+) T cell effector/memory generation and long-term memory is largely unaffected by physical differences in vaccine delivery to the skin via dried MA or ID suspension. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Use of a Recombinant Gamma-2 Herpesvirus Vaccine Vector against Dengue Virus in Rhesus Monkeys.

    PubMed

    Bischof, Georg F; Magnani, Diogo M; Ricciardi, Michael; Shin, Young C; Domingues, Aline; Bailey, Varian K; Gonzalez-Nieto, Lucas; Rakasz, Eva G; Watkins, David I; Desrosiers, Ronald C

    2017-08-15

    Research on vaccine approaches that can provide long-term protection against dengue virus infection is needed. Here we describe the construction, immunogenicity, and preliminary information on the protective capacity of recombinant, replication-competent rhesus monkey rhadinovirus (RRV), a persisting herpesvirus. One RRV construct expressed nonstructural protein 5 (NS5), while a second recombinant expressed a soluble variant of the E protein (E85) of dengue virus 2 (DENV2). Four rhesus macaques received a single vaccination with a mixture of both recombinant RRVs and were subsequently challenged 19 weeks later with 1 × 10(5) PFU of DENV2. During the vaccine phase, plasma of all vaccinated monkeys showed neutralizing activity against DENV2. Cellular immune responses against NS5 were also elicited, as evidenced by major histocompatibility complex class I (MHC-I) tetramer staining in the one vaccinated monkey that was Mamu-A*01 positive. Unlike two of two unvaccinated controls, two of the four vaccinated monkeys showed no detectable viral RNA sequences in plasma after challenge. One of these two monkeys also showed no anamnestic increases in antibody levels following challenge and thus appeared to be protected against the acquisition of DENV2 following high-dose challenge. Continued study will be needed to evaluate the performance of herpesviral and other persisting vectors for achieving long-term protection against dengue virus infection.IMPORTANCE Continuing studies of vaccine approaches against dengue virus (DENV) infection are warranted, particularly ones that may provide long-term immunity against all four serotypes. Here we investigated whether recombinant rhesus monkey rhadinovirus (RRV) could be used as a vaccine against DENV2 infection in rhesus monkeys. Upon vaccination, all animals generated antibodies capable of neutralizing DENV2. Two of four vaccinated monkeys showed no detectable viral RNA after subsequent high-dose DENV2 challenge at 19 weeks

  2. Protection against henipavirus infection by use of recombinant adeno-associated virus-vector vaccines.

    PubMed

    Ploquin, Aurélie; Szécsi, Judit; Mathieu, Cyrille; Guillaume, Vanessa; Barateau, Véronique; Ong, Kien Chai; Wong, Kum Thong; Cosset, François-Loïc; Horvat, Branka; Salvetti, Anna

    2013-02-01

    Nipah virus (NiV) and Hendra virus (HeV) are closely related, recently emerged paramyxoviruses that are capable of causing considerable morbidity and mortality in several mammalian species, including humans. Henipavirus-specific vaccines are still commercially unavailable, and development of novel antiviral strategies to prevent lethal infections due to henipaviruses is highly desirable. Here we describe the development of adeno-associated virus (AAV) vaccines expressing the NiV G protein. Characterization of these vaccines in mice demonstrated that a single intramuscular AAV injection was sufficient to induce a potent and long-lasting antibody response. Translational studies in hamsters further demonstrated that all vaccinated animals were protected against lethal challenge with NiV. In addition, this vaccine induced a cross-protective immune response that was able to protect 50% of the animals against a challenge by HeV. This study presents a new efficient vaccination strategy against henipaviruses and opens novel perspectives on the use of AAV vectors as vaccines against emergent diseases.

  3. Pathogenic bacteria as vaccine vectors: teaching old bugs new tricks.

    PubMed

    Carleton, Heather A

    2010-12-01

    As our scientific knowledge of bacteria grows, so does our ability to manipulate these bacteria to protect rather than infect mammalian hosts from a diverse group of diseases. The old axiom that the best way to protect from a disease is to get infected in the first place is not feasible in the face of the diverse group of pathogens that infect humans. Therefore, reprogramming bacteria to protect against diverse bacterial, viral, and parasitic diseases as well as cancer is a new reality in the field of vaccines.

  4. Applications of canarypox (ALVAC) vectors in human and veterinary vaccination.

    PubMed

    Taylor, J; Tartaglia, J; Rivière, M; Duret, C; Languet, B; Chappuis, G; Paoletti, E

    1994-01-01

    This paper presents data derived from safety and efficacy studies of ALVAC-based rabies and feline leukemia virus (FeLV) vaccine candidates in target species. Inoculation of the ALVAC-RG recombinant was well tolerated in all species including humans and very young dogs. Protection induced in dogs against rabies challenge was long-lasting and could be elicited in the face of high levels of maternally-derived neutralizing antibody. Parenteral inoculation of cats with an ALVAC-FeLV recombinant was safe and induced protection against persistent infection following oro-nasal FeLV challenge.

  5. Vaccine Vector for Sustained High-Level Antitumor CTL Response

    DTIC Science & Technology

    2011-01-01

    vector pCMV-Kan/neo which contains a CMV promoter immediately upstream of the insert site. A kanamycin resistant gene flanked by two FRT sequences...the entire MCMV genome and the NEU expression cassette. Following selection of recombinant BACs on the basis of kanamycin resistance, the Kan marker...was removed by flp-mediated recombination. [ polyA, polyadenylation site; Kan, kanamycin resistance gene for selection in bacteria; Frt, flp

  6. Protection induced by commercially available live-attenuated and recombinant viral vector vaccines against infectious laryngotracheitis virus in broiler chickens.

    PubMed

    Vagnozzi, Ariel; Zavala, Guillermo; Riblet, Sylva M; Mundt, Alice; García, Maricarmen

    2012-01-01

    Viral vector vaccines using fowl poxvirus (FPV) and herpesvirus of turkey (HVT) as vectors and carrying infectious laryngotracheitis virus (ILTV) genes are commercially available to the poultry industry in the USA. Different sectors of the broiler industry have used these vaccines in ovo or subcutaneously, achieving variable results. The objective of the present study was to determine the efficacy of protection induced by viral vector vaccines as compared with live-attenuated ILTV vaccines. The HVT-LT vaccine was more effective than the FPV-LT vaccine in mitigating the disease and reducing levels of challenge virus when applied in ovo or subcutaneously, particularly when the challenge was performed at 57 days rather than 35 days of age. While the FPV-LT vaccine mitigated clinical signs more effectively when administered subcutaneously than in ovo, it did not reduce the concentration of challenge virus in the trachea by either application route. Detection of antibodies against ILTV glycoproteins expressed by the viral vectors was a useful criterion to assess the immunogenicity of the vectors. The presence of glycoprotein I antibodies detected pre-challenge and post challenge in chickens vaccinated with HVT-LT indicated that the vaccine induced a robust antibody response, which was paralleled by significant reduction of clinical signs. The chicken embryo origin vaccine provided optimal protection by significantly mitigating the disease and reducing the challenge virus in chickens vaccinated via eye drop. The viral vector vaccines, applied in ovo and subcutaneously, provided partial protection, reducing to some degree clinical signs, and challenge VIRUS replication in the trachea.

  7. Efficacy of a virus-vectored vaccine against human and bovine respiratory syncytial virus infections.

    PubMed

    Taylor, Geraldine; Thom, Michelle; Capone, Stefania; Pierantoni, Angiolo; Guzman, Efrain; Herbert, Rebecca; Scarselli, Elisa; Napolitano, Federico; Giuliani, Alessandro; Folgori, Antonella; Colloca, Stefano; Cortese, Riccardo; Nicosia, Alfredo; Vitelli, Alessandra

    2015-08-12

    Human respiratory syncytial virus (HRSV) is a major cause of lower respiratory tract disease in children and the elderly for which there is still no effective vaccine. We have previously shown that PanAd3-RSV, which is a chimpanzee adenovirus-vectored vaccine candidate that expresses a secreted form of the HRSV F protein together with the N and M2-1 proteins of HRSV, is immunogenic in rodents and nonhuman primates, and protects mice and cotton rats from HRSV challenge. Because the extent to which protection demonstrated in rodent models will translate to humans is unclear, we have exploited the calf model of bovine RSV (BRSV) infection, which mimics HRSV disease in children more closely than do experimental models of unnatural laboratory hosts, to evaluate the safety and efficacy of the PanAd3-RSV vaccine. We show that PanAd3-RSV alone and in combination with a modified vaccinia Ankara expressing the same HRSV antigens (MVA-RSV) induced neutralizing antibodies and cellular immunity in young seronegative calves and protected against upper and lower respiratory tract infection and pulmonary disease induced by heterologous BRSV challenge. There was no evidence either of enhanced pulmonary pathology or of enhanced respiratory disease in vaccinated calves after BRSV challenge. These findings support the continued evaluation of the vectored RSV vaccines in man.

  8. The rationale of vectored gene-fusion vaccines against cancer: evolving strategies and latest evidence

    PubMed Central

    Ragonnaud, Emeline

    2013-01-01

    The development of vaccines that target tumor antigens in cancer has proven difficult. A major reason for this is that T cells specific for tumor self-antigens and neoantigens are eliminated or inactivated through mechanisms of tolerance. Antigen fusion strategies which increase the ability of vaccines to stimulate T cells that have escaped tolerance mechanisms, may have a particular potential as immunotherapies. This review highlights antigen fusion strategies that have been successful in stimulating the induction of T-cell immunity against cancer and counteracting tumor-associated tolerance. In preclinical studies, these strategies have shown to improve the potency of vectored vaccines through fusion of tumor antigen to proteins or protein domains that increase CD4+ T-cell help, CD8+ T-cell responses or both the CD4+ and CD8+ T-cell responses. However, in clinical trials such strategies seem to be less efficient when provided as a DNA vaccine. The first clinical trial using a viral vectored fusion-gene vaccine is expected to be tested as a partner in a heterologous prime-boost regimen directed against cervical cancer. PMID:24757514

  9. Complete tumor prevention by engineered tumor cell vaccines employing nonviral vectors.

    PubMed

    Moret-Tatay, Inés; Díaz, Joaquín; Marco, Francisco M; Crespo, Antonio; Aliño, Salvador F

    2003-12-01

    We report that 100% mice survival after tumor challenge is achieved with cytokine-engineered cells employing nonviral lipoplexes and without using viral vectors. We describe this effect with cytokine-secreting tumor cell vaccines, based on cell clones or fresh transfected cells. Tumor cells were transfected with murine granulocyte-macrophage colony-stimulating factor (GM-CSF) or IL-4 plasmids employing the cationic lipid DOTAP, were irradiated (150 Gy) and kept frozen until use. The transfection efficacy was analyzed by qRT-PCR and flow cytometry. Vaccination induced potent antitumor rejection, resulting in 100% mice survival. Furthermore, the antitumor immunity was long lasting, since a two-fold survival delay was observed in mice after tumor rechallenge (6 months later). While cell clones secreting GM-CSF were the most effective in wild-type tumor cell rejection, little or no effect was observed with clones secreting IL-4. We found similar antitumor efficacy employing fresh transfected cells by nonviral procedures, demonstrating that cells genetically modified by nonviral vectors (both clones and fresh transfected cells) are a safe and efficient tool for antitumor vaccines. These vaccines allow us to achieve the highest antitumor efficacy based on nonviral gene therapy techniques. In addition, the vaccination success with fresh transfected cells simplifies the procedure and provides new insights into the clinical application of nonviral gene therapy procedures.

  10. Novel methods for expression of foreign antigens in live vector vaccines

    PubMed Central

    Wang, Jin Yuan; Harley, Regina H.; Galen, James E.

    2013-01-01

    Bacterial live vector vaccines represent a vaccine development strategy that offers exceptional flexibility. In this approach, genes encoding protective antigens of unrelated bacterial, viral or parasitic pathogens are expressed in an attenuated bacterial vaccine strain that delivers these foreign antigens to the immune system, thereby eliciting relevant immune responses. Rather than expressing these antigens using low copy expression plasmids, here we pursue expression of foreign proteins from the live vector chromosome. Our strategy is designed to compensate for the inherent disadvantage of loss of gene dosage (vs. plasmid-based expression) by integrating antigen-encoding gene cassettes into multiple chromosomal sites already inactivated in an attenuated Salmonella enterica serovar Typhi vaccine candidate. We tested expression of a cassette encoding the green fluorescent protein (GFPuv) integrated separately into native guaBA, htrA or clyA chromosomal loci. Using single integrations, we show that expression levels of GFPuv are significantly affected by the site of integration, regardless of the inclusion of additional strong promoters within the incoming cassette. Using cassettes integrated into both guaBA and htrA, we observe cumulative synthesis levels from two integration sites superior to single integrations. Most importantly, we observe that GFPuv expression increases in a growth phase-dependent manner, suggesting that foreign antigen synthesis may be “tuned” to the physiology of the live vaccine. We expect this novel platform expression technology to prove invaluable in the development of a wide variety of multivalent live vector vaccines, capable of expressing multiple antigens from both chromosomal and plasmid-based expression systems within a single strain. PMID:23406777

  11. A Nonintegrative Lentiviral Vector-Based Vaccine Provides Long-Term Sterile Protection against Malaria

    PubMed Central

    Coutant, Frédéric; Sanchez David, Raul Yusef; Félix, Tristan; Boulay, Aude; Caleechurn, Laxmee; Souque, Philippe; Thouvenot, Catherine; Bourgouin, Catherine

    2012-01-01

    Trials testing the RTS,S candidate malaria vaccine and radiation-attenuated sporozoites (RAS) have shown that protective immunity against malaria can be induced and that an effective vaccine is not out of reach. However, longer-term protection and higher protection rates are required to eradicate malaria from the endemic regions. It implies that there is still a need to explore new vaccine strategies. Lentiviral vectors are very potent at inducing strong immunological memory. However their integrative status challenges their safety profile. Eliminating the integration step obviates the risk of insertional oncogenesis. Providing they confer sterile immunity, nonintegrative lentiviral vectors (NILV) hold promise as mass pediatric vaccine by meeting high safety standards. In this study, we have assessed the protective efficacy of NILV against malaria in a robust pre-clinical model. Mice were immunized with NILV encoding Plasmodium yoelii Circumsporozoite Protein (Py CSP) and challenged with sporozoites one month later. In two independent protective efficacy studies, 50% (37.5–62.5) of the animals were fully protected (p = 0.0072 and p = 0.0008 respectively when compared to naive mice). The remaining mice with detectable parasitized red blood cells exhibited a prolonged patency and reduced parasitemia. Moreover, protection was long-lasting with 42.8% sterile protection six months after the last immunization (p = 0.0042). Post-challenge CD8+ T cells to CSP, in contrast to anti-CSP antibodies, were associated with protection (r = −0.6615 and p = 0.0004 between the frequency of IFN-g secreting specific T cells in spleen and parasitemia). However, while NILV and RAS immunizations elicited comparable immunity to CSP, only RAS conferred 100% of sterile protection. Given that a better protection can be anticipated from a multi-antigen vaccine and an optimized vector design, NILV appear as a promising malaria vaccine. PMID:23133649

  12. Adventitious agents and live viral vectored vaccines: Considerations for archiving samples of biological materials for retrospective analysis.

    PubMed

    Klug, Bettina; Robertson, James S; Condit, Richard C; Seligman, Stephen J; Laderoute, Marian P; Sheets, Rebecca; Williamson, Anna-Lise; Gurwith, Marc; Kochhar, Sonali; Chapman, Louisa; Carbery, Baevin; Mac, Lisa M; Chen, Robert T

    2016-12-12

    Vaccines are one of the most effective public health medicinal products with an excellent safety record. As vaccines are produced using biological materials, there is a need to safeguard against potential contamination with adventitious agents. Adventitious agents could be inadvertently introduced into a vaccine through starting materials used for production. Therefore, extensive testing has been recommended at specific stages of vaccine manufacture to demonstrate the absence of adventitious agents. Additionally, the incorporation of viral clearance steps in the manufacturing process can aid in reducing the risk of adventitious agent contamination. However, for live viral vaccines, aside from possible purification of the virus or vector, extensive adventitious agent clearance may not be feasible. In the event that an adventitious agent is detected in a vaccine, it is important to determine its origin, evaluate its potential for human infection and pathology, and discern which batches of vaccine may have been affected in order to take risk mitigation action. To achieve this, it is necessary to have archived samples of the vaccine and ancillary components, ideally from developmental through to current batches, as well as samples of the biological materials used in the manufacture of the vaccine, since these are the most likely sources of an adventitious agent. The need for formal guidance on such vaccine sample archiving has been recognized but not fulfilled. We summarize in this paper several prior major cases of vaccine contamination with adventitious agents and provide points for consideration on sample archiving of live recombinant viral vector vaccines for use in humans.

  13. HIV-1 vaccine-specific responses induced by Listeria vector vaccines are maintained in mice subsequently infected with a model helminth parasite, Schistosoma mansoni.

    PubMed

    Shollenberger, Lisa M; Bui, Cac T; Paterson, Yvonne; Nyhoff, Lindsay; Harn, Donald A

    2013-11-19

    In areas co-endemic for helminth parasites and HIV/AIDS, infants are often administered vaccines prior to infection with immune modulatory helminth parasites. Systemic Th2 biasing and immune suppression caused by helminth infection reduces cell-mediated responses to vaccines such as tetanus toxoid and BCG. Therefore, we asked if infection with helminthes post-vaccination, alters already established vaccine induced immune responses. In our model, mice are vaccinated against HIV-1 Gag using a Listeria vaccine vector (Lm-Gag) in a prime-boost manner, then infected with the human helminth parasite Schistosoma mansoni. This allows us to determine if established vaccine responses are maintained or altered after helminth infection. Our second objective asked if helminth infection post-vaccination alters the recipient's ability to respond to a second boost. Here we compared responses between uninfected mice, schistosome infected mice, and infected mice that were given an anthelminthic, which occurred coincident with the boost or four weeks prior, as well as comparing to un-boosted mice. We report that HIV-1 vaccine-specific responses generated by Listeria vector HIV-1 vaccines are maintained following subsequent chronic schistosome infection, providing further evidence that Listeria vector vaccines induce potent vaccine-specific responses that can withstand helminth infection. We also were able to demonstrate that administration of a second Listeria boost, which markedly enhanced the immune response, was minimally impacted by schistosome infection, or anthelminthic therapy. Surprisingly, we also observed enhanced antibody responses to HIV Gag in vaccinated mice subsequently infected with schistosomes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Vaccinia virus vectors: new strategies for producing recombinant vaccines.

    PubMed Central

    Hruby, D E

    1990-01-01

    The development and continued refinement of techniques for the efficient insertion and expression of heterologous DNA sequences from within the genomic context of infectious vaccinia virus recombinants are among the most promising current approaches towards effective immunoprophylaxis against a variety of protozoan, viral, and bacterial human pathogens. Because of its medical relevance, this area is the subject of intense research interest and has evolved rapidly during the past several years. This review (i) provides an updated overview of the technology that exists for assembling recombinant vaccinia virus strains, (ii) discusses the advantages and disadvantages of these approaches, (iii) outlines the areas of outgoing research directed towards overcoming the limitations of current techniques, and (iv) provides some insight (i.e., speculation) about probable future refinements in the use of vaccinia virus as a vector. PMID:2187593

  15. Oral Vaccination With Adeno-associated Virus Vectors Expressing the Neu Oncogene Inhibits the Growth of Murine Breast Cancer

    PubMed Central

    Steel, Jason C; Di Pasquale, Giovanni; Ramlogan, Charmaine A; Patel, Vyomesh; Chiorini, John A; Morris, John C

    2013-01-01

    Recombinant adeno-associated viruses (AAV) have been used for therapeutic gene transfer. These vectors offer a number of advantages including resistance to the effects of pH, a broad cellular tropism, efficient gene transfer, persistence of gene expression, and little toxicity. AAV vectors; however, at high doses can induce humoral and cellular immune responses. While potentially problematic for replacement gene therapy, this effect may be advantageous for antitumor vaccination. We examined the activity of an oral and intramuscular antitumor vaccination using AAV serotypes 5 and 6 expressing a truncated neu oncogene in a neu-positive murine TUBO breast cancer model. Mice receiving a single oral administration of AAV5-neu or AAV6-neu demonstrated improved survival. Oral vaccination significantly improved survivals compared with intramuscular vaccination. Mice vaccinated with AAV6-neu survived longer than those treated with AAV5-neu. Vaccination with AAV5-neu or AAV6-neu induced both humoral and cellular immune responses against the NEU antigen. These responses were more robust in the mice undergoing oral vaccination compared with mice receiving the intramuscular vaccination. Protection from tumor was long lasting with 80% of the animals treated with oral AAV6-neu surviving a re-challenge with TUBO cells at 120 and 320 days post-vaccination. Further evaluation of AAV-based vectors as tumor vaccines is warranted. PMID:23295951

  16. Viral vectors and vaccines. 16-19 November 1998, Williamsburg, Virginia, USA.

    PubMed

    Seaver, S S

    1999-02-01

    The fifth annual meeting of the Williamsburg BioProcessing Foundation, now renamed as Viral Vectors and Vaccines, attracted over 200 attendees. Besides the regular roster of speakers, the meeting featured 36 vendor booths, a whole morning devoted to 30-min vendor presentations and several posters. The extensive use of adenovirus (Ad) in gene therapy was evident from the number of talks on the subject.

  17. Limited infection upon human exposure to a recombinant raccoon pox vaccine vector.

    PubMed

    Rocke, Tonie E; Dein, F Joshua; Fuchsberger, Martina; Fox, Barry C; Stinchcomb, Dan T; Osorio, Jorge E

    2004-07-29

    A laboratory accident resulted in human exposure to a recombinant raccoon poxvirus (RCN) developed as a vaccine vector for antigens of Yersinia pestis for protection of wild rodents (and other animals) against plague. Within 9 days, the patient developed a small blister that healed within 4 weeks. Raccoon poxvirus was cultured from the lesion, and the patient developed antibody to plague antigen (F1) and RCN. This is the first documented case of human exposure to RCN.

  18. Bacteroides Fragilis OmpA: Utility as a Live Vaccine Vector for Biodefense Agents

    DTIC Science & Technology

    2008-01-01

    AD_________________ Award Number: W81XWH-05-1-0145 TITLE: Bacteroides fragilis OmpA: Utility...29 DEC 2007 4. TITLE AND SUBTITLE Bacteroides fragilis OmpA: Utility as a live vaccine vector for Biodefense Agents 5a. CONTRACT NUMBER 5b...negative anaerobe that normally resides in the gut . There are four homologs for ompA in the genome. The purpose of this study was to construct a B. fragilis

  19. Bacteroides Fragilis OMP A: Utility as a Live Vaccine Vector for Biodefense Agents

    DTIC Science & Technology

    2007-01-01

    AD_________________ Award Number: W81XWH-05-1-0145 TITLE: Bacteroides Fragilis OMP A: Utility... Bacteroides Fragilis OMP A: Utility as a Live Vaccine Vector for Biodefense Agents 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-05-1-0145 5c...the gut . There are four homologs for ompA in the genome. The purpose of this study was to construct a B. fragilisompA deletant and to begin to

  20. Vector Development for the Expression of Foreign Proteins in the Vaccine Strain Brucella abortus S19

    PubMed Central

    Comerci, Diego J.; Pollevick, Guido D.; Vigliocco, Ana M.; Frasch, Alberto C. C.; Ugalde, Rodolfo A.

    1998-01-01

    A vector for the expression of foreign antigens in the vaccine strain Brucella abortus S19 was developed by using a DNA fragment containing the regulatory sequences and the signal peptide of the Brucella bcsp31 gene. This fragment was cloned in broad-host-range plasmid pBBR4MCS, resulting in plasmid pBEV. As a reporter protein, a repetitive antigen of Trypanosoma cruzi was used. The recombinant fusion protein is stably expressed and secreted into the Brucella periplasmic space, inducing a good antibody response against the T. cruzi antigen. The expression of the repetitive antigen in Brucella neither altered its growth pattern nor generated a toxic or lethal effect during experimental infection. The application of this strategy for the generation of live recombinant vaccines and the tagging of B. abortus S19 vaccine is discussed. This is the first time that a recombinant protein has been expressed in the periplasm of brucellae. PMID:9673273

  1. Designing Efficacious Vesicular Stomatitis Virus-Vectored Vaccines Against Ebola Virus.

    PubMed

    Wong, Gary; Qiu, Xiangguo

    2016-01-01

    Infection with the Ebola virus (EBOV) causes an aggressive hemorrhagic disease in humans and nonhuman primates. Traditional approaches, such as vaccination with inactivated virion preparations, have had limited efficacy, whereas immunization with live-attenuated EBOV is not feasible due to the highly lethal nature of the pathogen. This has necessitated the development of other approaches towards an effective EBOV vaccine. Over the past decade, recombinant viruses expressing the EBOV glycoprotein (GP) have constituted the most promising platforms, as evidenced by their ability to protect naïve nonhuman primates from a lethal EBOV challenge. The vesicular stomatitis virus (VSV) is one such vector and is currently progressing through the clinical pipeline. This chapter presents methodologies for the design, cloning, rescue, and preparation of live, recombinant VSV vaccines expressing GP for research purposes.

  2. Evaluation of a Fiber-Modified Adenovirus Vector Vaccine against Foot-and-Mouth Disease in Cattle

    PubMed Central

    Medina, Gisselle N.; Montiel, Nestor; Diaz-San Segundo, Fayna; Sturza, Diego; Ramirez-Medina, Elizabeth; Grubman, Marvin J.

    2015-01-01

    Novel vaccination approaches against foot-and-mouth disease (FMD) include the use of replication-defective human adenovirus type 5 (Ad5) vectors that contain the capsid-encoding regions of FMD virus (FMDV). Ad5 containing serotype A24 capsid sequences (Ad5.A24) has proved to be effective as a vaccine against FMD in livestock species. However, Ad5-vectored FMDV serotype O1 Campos vaccine (Ad5.O1C.2B) provides only partial protection of cattle against homologous challenge. It has been reported that a fiber-modified Ad5 vector expressing Arg-Gly-Asp (RGD) enhances transduction of antigen-presenting cells (APC) in mice. In the current study, we assessed the efficacy of a fiber-modified Ad5 (Adt.O1C.2B.RGD) in cattle. Expression of FMDV capsid proteins was superior in cultured cells infected with the RGD-modified vector. Furthermore, transgene expression of Adt.O1C.2B.RGD was enhanced in cell lines that constitutively express integrin αvβ6, a known receptor for FMDV. In contrast, capsid expression in cattle-derived enriched APC populations was not enhanced by infection with this vector. Our data showed that vaccination with the two vectors yielded similar levels of protection against FMD in cattle. Although none of the vaccinated animals had detectable viremia, FMDV RNA was detected in serum samples from animals with clinical signs. Interestingly, CD4+ and CD8+ gamma interferon (IFN-γ)+ cell responses were detected at significantly higher levels in animals vaccinated with Adt.O1C.2B.RGD than in animals vaccinated with Ad5.O1C.2B. Our results suggest that inclusion of an RGD motif in the fiber of Ad5-vectored FMD vaccine improves transgene delivery and cell-mediated immunity but does not significantly enhance vaccine performance in cattle. PMID:26607309

  3. A pilot study comparing the development of EIAV Env-specific antibodies induced by DNA/recombinant vaccinia-vectored vaccines and an attenuated Chinese EIAV vaccine.

    PubMed

    Meng, Qinglai; Lin, Yuezhi; Ma, Jian; Ma, Yan; Zhao, Liping; Li, Shenwei; Yang, Kai; Zhou, Jianhua; Shen, Rongxian; Zhang, Xiaoyan; Shao, Yiming

    2012-12-01

    Data from successful attenuated lentiviral vaccine studies indicate that fully mature Env-specific antibodies characterized by high titer, high avidity, and the predominant recognition of conformational epitopes are associated with protective efficacy. Although vaccination with a DNA prime/recombinant vaccinia-vectored vaccine boost strategy has been found to be effective in some trials with non-human primate/simian/human immunodeficiency virus (SHIV) models, it remains unclear whether this vaccination strategy could elicit mature equine infectious anemia virus (EIAV) Env-specific antibodies, thus protecting vaccinated horses against EIAV infection. Therefore, in this pilot study we vaccinated horses using a strategy based on DNA prime/recombinant Tiantan vaccinia (rTTV)-vectored vaccines encoding EIAV env and gag genes, and observed the development of Env-specific antibodies, neutralizing antibodies, and p26-specific antibodies. Vaccination with DNA induced low titer, low avidity, and the predominant recognition of linear epitopes by Env-specific antibodies, which was enhanced by boosting vaccinations with rTTV vaccines. However, the maturation levels of Env-specific antibodies induced by the DNA/rTTV vaccines were significantly lower than those induced by the attenuated vaccine EIAV(FDDV). Additionally, DNA/rTTV vaccines did not elicit broadly neutralizing antibodies. After challenge with a virulent EIAV strain, all of the vaccinees and control horses died from EIAV disease. These data indicate that the regimen of DNA prime/rTTV vaccine boost did not induce mature Env-specific antibodies, which might have contributed to immune protection failure.

  4. A Pilot Study Comparing the Development of EIAV Env-Specific Antibodies Induced by DNA/Recombinant Vaccinia-Vectored Vaccines and an Attenuated Chinese EIAV Vaccine

    PubMed Central

    Meng, Qinglai; Lin, Yuezhi; Ma, Jian; Ma, Yan; Zhao, Liping; Li, Shenwei; Yang, Kai; Zhou, Jianhua; Shen, Rongxian

    2012-01-01

    Abstract Data from successful attenuated lentiviral vaccine studies indicate that fully mature Env-specific antibodies characterized by high titer, high avidity, and the predominant recognition of conformational epitopes are associated with protective efficacy. Although vaccination with a DNA prime/recombinant vaccinia-vectored vaccine boost strategy has been found to be effective in some trials with non-human primate/simian/human immunodeficiency virus (SHIV) models, it remains unclear whether this vaccination strategy could elicit mature equine infectious anemia virus (EIAV) Env-specific antibodies, thus protecting vaccinated horses against EIAV infection. Therefore, in this pilot study we vaccinated horses using a strategy based on DNA prime/recombinant Tiantan vaccinia (rTTV)-vectored vaccines encoding EIAV env and gag genes, and observed the development of Env-specific antibodies, neutralizing antibodies, and p26-specific antibodies. Vaccination with DNA induced low titer, low avidity, and the predominant recognition of linear epitopes by Env-specific antibodies, which was enhanced by boosting vaccinations with rTTV vaccines. However, the maturation levels of Env-specific antibodies induced by the DNA/rTTV vaccines were significantly lower than those induced by the attenuated vaccine EIAVFDDV. Additionally, DNA/rTTV vaccines did not elicit broadly neutralizing antibodies. After challenge with a virulent EIAV strain, all of the vaccinees and control horses died from EIAV disease. These data indicate that the regimen of DNA prime/rTTV vaccine boost did not induce mature Env-specific antibodies, which might have contributed to immune protection failure. PMID:23171359

  5. Evaluation of fiber-modified adenovirus vector-vaccine against foot-and-mouth diseaes in cattle

    USDA-ARS?s Scientific Manuscript database

    Novel vaccination approaches against foot-and-mouth-disease (FMD) include the use of a replication-defective human adenovirus type 5 vector (Ad5) that contains the capsid encoding regions of FMD virus (FMDV). An Ad5.A24 has proven effective as a vaccine against FMD in swine and cattle. However, ther...

  6. Unique safety issues associated with virus-vectored vaccines: Potential for and theoretical consequences of recombination with wild type virus strains.

    PubMed

    Condit, Richard C; Williamson, Anna-Lise; Sheets, Rebecca; Seligman, Stephen J; Monath, Thomas P; Excler, Jean-Louis; Gurwith, Marc; Bok, Karin; Robertson, James S; Kim, Denny; Michael Hendry, R; Singh, Vidisha; Mac, Lisa M; Chen, Robert T

    2016-12-12

    In 2003 and 2013, the World Health Organization convened informal consultations on characterization and quality aspects of vaccines based on live virus vectors. In the resulting reports, one of several issues raised for future study was the potential for recombination of virus-vectored vaccines with wild type pathogenic virus strains. This paper presents an assessment of this issue formulated by the Brighton Collaboration. To provide an appropriate context for understanding the potential for recombination of virus-vectored vaccines, we review briefly the current status of virus-vectored vaccines, mechanisms of recombination between viruses, experience with recombination involving live attenuated vaccines in the field, and concerns raised previously in the literature regarding recombination of virus-vectored vaccines with wild type virus strains. We then present a discussion of the major variables that could influence recombination between a virus-vectored vaccine and circulating wild type virus and the consequences of such recombination, including intrinsic recombination properties of the parent virus used as a vector; sequence relatedness of vector and wild virus; virus host range, pathogenesis and transmission; replication competency of vector in target host; mechanism of vector attenuation; additional factors potentially affecting virulence; and circulation of multiple recombinant vectors in the same target population. Finally, we present some guiding principles for vector design and testing intended to anticipate and mitigate the potential for and consequences of recombination of virus-vectored vaccines with wild type pathogenic virus strains. Copyright © 2016. Published by Elsevier Ltd.

  7. Vpx-containing Dendritic Cell Vaccine Vectors Induce CTLs and Reactivate Latent HIV-1 in vitro

    PubMed Central

    Norton, Thomas D.; Miller, Elizabeth A.; Bhardwaj, Nina; Landau, Nathaniel R.

    2015-01-01

    Eradication of HIV-1 from an infected individual requires a means of inducing production of virus from latently infected cells and stimulating an immune response against the infected cells. We report the development of lentiviral vectors that transduce dendritic cells (DCs) to both induce production of virus from latently infected cells and stimulate antigen-specific CTLs. The vectors package Vpx, a lentiviral accessory protein that counteracts the SAMHD1-mediated block to DC transduction, allowing for long-term expression of vector-encoded proteins. The vectors encode influenza or HIV-1-derived epitopes fused via a self-cleaving peptide to CD40L that releases the peptide into the endoplasmic reticulum for entry into the antigen presentation pathway. Expression of CD40L caused transduced DCs to mature and produce Th1-skewing cytokines. The DCs presented antigen to CD8 T cells, enhancing antigen-specific CTLs. Coculture of the transduced DCs with latently infected cells induced high level virus production, an effect that was mediated by TNF-α. The ability of a DC vaccine to reactivate latent HIV-1 and stimulate an adaptive immune response provides a means to reduce the size of the latent reservoir in patients. This strategy can also be applied to develop DC vaccines for other diseases. PMID:25567537

  8. Co-Expression of Tumor Antigen and Interleukin-2 From an Adenoviral Vector Augments the Efficiency of Therapeutic Tumor Vaccination

    PubMed Central

    Jensen, Benjamin Anderschou Holbech; Steffensen, Maria Abildgaard; Nielsen, Karen Nørgaard; Christensen, Jan Pravsgaard; Thomsen, Allan Randrup; Holst, Peter Johannes

    2014-01-01

    We have previously shown that for the majority of antigens, adenoviral vaccines expressing the target antigen fused to the MHC associated invariant chain (Ii) induce an accelerated, augmented, and prolonged transgene-specific CD8+ T-cell response. Here we describe a new adenoviral vaccine vector approach where the target antigen fused to Ii is expressed from the adenoviral E1 region and IL-2 is expressed from the E3 region. Immunization of mice with this new vector construct resulted in an augmented primary effector CD8+ T-cell response. Furthermore, in a melanoma model we observed significantly prolonged tumor control in vaccinated wild type (WT) mice. The improved tumor control required antigen-specific cells, since no tumor control was observed, unless the melanoma cells expressed the vaccine targeted antigen. We also tested our new vaccine in immunodeficient (CD80/86 deficient) mice. Following vaccination with the IL-2 expressing construct, these mice were able to raise a delayed but substantial CD8+ T-cell response, and to control melanoma growth nearly as efficaciously as similarly vaccinated WT mice. Taken together, these results demonstrate that current vaccine vectors can be improved and even tailored to meet specific demands: in the context of therapeutic vaccination, the capacity to promote an augmented effector T-cell response. PMID:25023330

  9. Advances in host and vector development for the production of plasmid DNA vaccines.

    PubMed

    Mairhofer, Juergen; Lara, Alvaro R

    2014-01-01

    Recent developments in DNA vaccine research provide a new momentum for this rather young and potentially disruptive technology. Gene-based vaccines are capable of eliciting protective immunity in humans to persistent intracellular pathogens, such as HIV, malaria, and tuberculosis, for which the conventional vaccine technologies have failed so far. The recent identification and characterization of genes coding for tumor antigens has stimulated the development of DNA-based antigen-specific cancer vaccines. Although most academic researchers consider the production of reasonable amounts of plasmid DNA (pDNA) for immunological studies relatively easy to solve, problems often arise during this first phase of production. In this chapter we review the current state of the art of pDNA production at small (shake flasks) and mid-scales (lab-scale bioreactor fermentations) and address new trends in vector design and strain engineering. We will guide the reader through the different stages of process design starting from choosing the most appropriate plasmid backbone, choosing the right Escherichia coli (E. coli) strain for production, and cultivation media and scale-up issues. In addition, we will address some points concerning the safety and potency of the produced plasmids, with special focus on producing antibiotic resistance-free plasmids. The main goal of this chapter is to make immunologists aware of the fact that production of the pDNA vaccine has to be performed with as much as attention and care as the rest of their research.

  10. A complex adenovirus-vectored vaccine against Rift Valley fever virus protects mice against lethal infection in the presence of preexisting vector immunity.

    PubMed

    Holman, David H; Penn-Nicholson, Adam; Wang, Danher; Woraratanadharm, Jan; Harr, Mary-Katherine; Luo, Min; Maher, Ellen M; Holbrook, Michael R; Dong, John Y

    2009-11-01

    Rift Valley fever virus (RVFV) has been cited as a potential biological-weapon threat due to the serious and fatal disease it causes in humans and animals and the fact that this mosquito-borne virus can be lethal in an aerosolized form. Current human and veterinary vaccines against RVFV, however, are outdated, inefficient, and unsafe. We have incorporated the RVFV glycoprotein genes into a nonreplicating complex adenovirus (CAdVax) vector platform to develop a novel RVFV vaccine. Mice vaccinated with the CAdVax-based vaccine produced potent humoral immune responses and were protected against lethal RVFV infection. Additionally, protection was elicited in mice despite preexisting immunity to the adenovirus vector.

  11. Live-Attenuated Bacterial Vectors: Tools for Vaccine and Therapeutic Agent Delivery

    PubMed Central

    Lin, Ivan Y. C.; Van, Thi Thu Hao; Smooker, Peter M.

    2015-01-01

    Genetically attenuated microorganisms, including pathogenic and commensal bacteria, can be engineered to carry and deliver heterologous antigens to elicit host immunity against both the vector as well as the pathogen from which the donor gene is derived. These live attenuated bacterial vectors have been given much attention due to their capacity to induce a broad range of immune responses including localized mucosal, as well as systemic humoral and/or cell-mediated immunity. In addition, the unique tumor-homing characteristics of these bacterial vectors has also been exploited for alternative anti-tumor vaccines and therapies. In such approach, tumor-associated antigen, immunostimulatory molecules, anti-tumor drugs, or nucleotides (DNA or RNA) are delivered. Different potential vectors are appropriate for specific applications, depending on their pathogenic routes. In this review, we survey and summarize the main features of the different types of live bacterial vectors and discussed the clinical applications in the field of vaccinology. In addition, different approaches for using live attenuated bacterial vectors for anti-cancer therapy is discussed, and some promising pre-clinical and clinical studies in this field are outlined. PMID:26569321

  12. Immunoresponse induced by Newcastle disease virus (NDV) vaccine vectors in commercial chicks in the presence of NDV maternal antibody

    USDA-ARS?s Scientific Manuscript database

    To address the concern that Newcastle disease virus (NDV) maternal antibody (Mab) in chicks may suppress the immunoresponse to the NDV vectored vaccines, we evaluated the replication and immunogenicity of the LaSota and PHY LMV42 strain-based vectors in chickens which had naturally acquired NDV mate...

  13. Protection and antibody response caused by turkey herpesvirus vector Newcastle disease vaccine.

    PubMed

    Esaki, Motoyuki; Godoy, Alecia; Rosenberger, Jack K; Rosenberger, Sandra C; Gardin, Yannick; Yasuda, Atsushi; Dorsey, Kristi Moore

    2013-12-01

    Newcastle disease (ND) is prevalent worldwide and causes significant clinical and economic losses to the poultry industry. Current vaccine programs using live attenuated vaccines and inactivated vaccines have limitations, and new vaccines with distinct features are needed. To offer an alternative solution to control ND, a turkey herpesvirus vector Newcastle disease vaccine (HVT/ND) expressing the fusion gene of Newcastle disease virus (NDV) has been developed. First, immunogenicity of the HVT/ND was evaluated in specific-pathogen-free layer chickens after vaccination by the in ovo route to 18-day-old embryos or by the subcutaneous route to 1-day-old chicks. Antibodies against NDV were detected at 24 days of age using a commercial NDV enzyme-linked immunosorbent assay (ELISA) kit and the hemagglutination inhibition test. At least 90% of chickens were protected against challenge with velogenic neurotropic NDV Texas GB strain (genotype II; pathotype velogenic) at 4 wk of age, while none of the nonvaccinated, challenged controls were protected from challenge. Second, the age at which a vaccinated chicken elicits an immunologic response to the HVT/ND prepared for this study, and thus is protected from ND virus, was assessed in commercial broiler chickens after in ovo vaccination of 18-day-old embryos. Challenge was conducted using a low-virulence NDV strain (genotype II; pathotype lentogenic) via the respiratory tract each week between 1 and 5 wk of age, in order to mimic the situation in areas where virulent NDV strains do not normally exist and low-virulence strains cause mild respiratory symptoms leading to economic losses. Protection was evaluated by the presence or absence of isolated virus from tracheal swabs at 5 days postchallenge. Partial protection was observed at 3 wk of age, when 6 out of 10 (60%) chickens were protected. Full protection was obtained at 4 and 5 wk of age, when 9 out of 10 (90%) and 10 out of 10 (100%) chickens were protected, respectively

  14. Vaccination with Vesicular Stomatitis Virus-Vectored Chimeric Hemagglutinins Protects Mice against Divergent Influenza Virus Challenge Strains.

    PubMed

    Ryder, Alex B; Nachbagauer, Raffael; Buonocore, Linda; Palese, Peter; Krammer, Florian; Rose, John K

    2015-12-16

    Seasonal influenza virus infections continue to cause significant disease each year, and there is a constant threat of the emergence of reassortant influenza strains causing a new pandemic. Available influenza vaccines are variably effective each season, are of limited scope at protecting against viruses that have undergone significant antigenic drift, and offer low protection against newly emergent pandemic strains. "Universal" influenza vaccine strategies that focus on the development of humoral immunity directed against the stalk domains of the viral hemagglutinin (HA) show promise for protecting against diverse influenza viruses. Here, we describe such a strategy that utilizes vesicular stomatitis virus (VSV) as a vector for chimeric hemagglutinin (cHA) antigens. This vaccination strategy is effective at generating HA stalk-specific, broadly cross-reactive serum antibodies by both intramuscular and intranasal routes of vaccination. We show that prime-boost vaccination strategies provide protection against both lethal homologous and heterosubtypic influenza challenge and that protection is significantly improved with intranasal vaccine administration. Additionally, we show that vaccination with VSV-cHAs generates greater stalk-specific and cross-reactive serum antibodies than does vaccination with VSV-vectored full-length HAs, confirming that cHA-based vaccination strategies are superior at generating stalk-specific humoral immunity. VSV-vectored influenza vaccines that express chimeric hemagglutinin antigens offer a novel means for protecting against widely diverging influenza viruses. Universal influenza vaccination strategies should be capable of protecting against a wide array of influenza viruses, and we have developed such an approach utilizing a single viral vector system. The potent antibody responses that these vaccines generate are shown to protect mice against lethal influenza challenges with highly divergent viruses. Notably, intranasal vaccination

  15. Comparison of infectious bursal disease live vaccines and a HVT-IBD vector vaccine and their effects on the immune system of commercial layer pullets.

    PubMed

    Prandini, Francesco; Simon, Birgid; Jung, Arne; Pöppel, Manfred; Lemiere, Stéphane; Rautenschlein, Silke

    2016-01-01

    Infectious bursal disease (IBD) is an economically important disease affecting poultry production worldwide. Previous experimental studies indicated that IBD live vaccination may induce transient immunosuppression, leading to suboptimal vaccine responses and therefore insufficient protection against other pathogens. Layer pullets are commonly not only vaccinated against IBD within their rearing period, but also against a variety of other pathogens. Therefore, it is of interest to investigate the effects of different IBD vaccination regimes on conventionally applied vaccines against other pathogens, and possible protection against widely spread very virulent IBD-virus (vvIBDV). A commercially available Herpesvirus of turkey vector vaccine (vHVT-IBD) expressing viral protein 2 of IBDV, and two IBD live vaccines were compared in commercial pullets for their effects on circulating B cell numbers, the ability of vaccinated birds to mount a humoral immune response against different antigens as well as their ability to induce protection against vvIBDV challenge. The results of this study demonstrate a clear immunosuppressive effect of the intermediate plus IBD live vaccine on the humoral branch of the immune system. On the other hand, no detectable effects of vHVT-IBD vaccination on these parameters were observed. All tested IBD vaccines protected against clinical IBD, although none induced sterile immunity in commercial layer pullets. vHVT-IBD-vaccinated birds showed significantly less lesions after vvIBDV challenge than IBD live-vaccinated or non-vaccinated birds (P < 0.05). Therefore, vHVT-IBD may be a suitable alternative to conventional IBD live vaccines, and may be applied even in the presence of maternally derived IBD antibodies without induction of detectable humoral immunosuppression.

  16. Avian CD154 enhances humoral and cellular immune responses induced by an adenovirus vector-based vaccine in chickens.

    PubMed

    Sánchez Ramos, Oliberto; González Pose, Alain; Gómez-Puerta, Silvia; Noda Gomez, Julia; Vega Redondo, Armando; Águila Benites, Julio César; Suárez Amarán, Lester; Parra, Natalie C; Toledo Alonso, Jorge R

    2011-05-01

    Recombinant adenoviral vectors have emerged as an attractive system for veterinary vaccines development. However, for poultry vaccination a very important criterion for an ideal vaccine is its low cost. The objective of this study was to test the ability of chicken CD154 to enhance the immunogenicity of an adenoviral vector-based vaccine against avian influenza virus in order to reduce the amount of antigen required to induce an effective immune response in avian. Chickens were vaccinated with three different doses of adenoviral vectors encoding either HA (AdHA), or HA fused to extracellular domain chicken's CD154 (AdHACD). Hemagglutination inhibition (HI) assay and relative quantification of IFN-γ showed that the adenoviral vector encoding for the chimeric antigen is able to elicit an improved humoral and cellular immune response, which demonstrated that CD154 can be used as a molecular adjuvant allowing to reduce in about 50-fold the amount of adenoviral vector vaccine required to induce an effective immune response.

  17. Recombinant Isfahan Virus and Vesicular Stomatitis Virus Vaccine Vectors Provide Durable, Multivalent, Single-Dose Protection against Lethal Alphavirus Challenge

    PubMed Central

    Matassov, Demetrius; Seymour, Robert L.; Latham, Theresa; Gorchakov, Rodion V.; Nowak, Rebecca M.; Leal, Grace; Hamm, Stefan; Eldridge, John H.; Tesh, Robert B.; Clarke, David K.

    2017-01-01

    ABSTRACT The demonstrated clinical efficacy of a recombinant vesicular stomatitis virus (rVSV) vaccine vector has stimulated the investigation of additional serologically distinct Vesiculovirus vectors as therapeutic and/or prophylactic vaccine vectors to combat emerging viral diseases. Among these viral threats are the encephalitic alphaviruses Venezuelan equine encephalitis virus (VEEV) and Eastern equine encephalitis virus (EEEV), which have demonstrated potential for natural disease outbreaks, yet no licensed vaccines are available in the event of an epidemic. Here we report the rescue of recombinant Isfahan virus (rISFV) from genomic cDNA as a potential new vaccine vector platform. The rISFV genome was modified to attenuate virulence and express the VEEV and EEEV E2/E1 surface glycoproteins as vaccine antigens. A single dose of the rISFV vaccine vectors elicited neutralizing antibody responses and protected mice from lethal VEEV and EEEV challenges at 1 month postvaccination as well as lethal VEEV challenge at 8 months postvaccination. A mixture of rISFV vectors expressing the VEEV and EEEV E2/E1 glycoproteins also provided durable, single-dose protection from lethal VEEV and EEEV challenges, demonstrating the potential for a multivalent vaccine formulation. These findings were paralleled in studies with an attenuated form of rVSV expressing the VEEV E2/E1 glycoproteins. Both the rVSV and rISFV vectors were attenuated by using an approach that has demonstrated safety in human trials of an rVSV/HIV-1 vaccine. Vaccines based on either of these vaccine vector platforms may present a safe and effective approach to prevent alphavirus-induced disease in humans. IMPORTANCE This work introduces rISFV as a novel vaccine vector platform that is serologically distinct and phylogenetically distant from VSV. The rISFV vector has been attenuated by an approach used for an rVSV vector that has demonstrated safety in clinical studies. The vaccine potential of the rISFV vector

  18. On the efficacy of malaria DNA vaccination with magnetic gene vectors.

    PubMed

    Nawwab Al-Deen, Fatin; Ma, Charles; Xiang, Sue D; Selomulya, Cordelia; Plebanski, Magdalena; Coppel, Ross L

    2013-05-28

    We investigated the efficacy and types of immune responses from plasmid malaria DNA vaccine encoding VR1020-PyMSP119 condensed on the surface of polyethyleneimine (PEI)-coated SPIONs. In vivo mouse studies were done firstly to determine the optimum magnetic vector composition, and then to observe immune responses elicited when magnetic vectors were introduced via different administration routes. Higher serum antibody titers against PyMSP119 were observed with intraperitoneal and intramuscular injections than subcutaneous and intradermal injections. Robust IgG2a and IgG1 responses were observed for intraperitoneal administration, which could be due to the physiology of peritoneum as a major reservoir of macrophages and dendritic cells. Heterologous DNA prime followed by single protein boost vaccination regime also enhanced IgG2a, IgG1, and IgG2b responses, indicating the induction of appropriate memory immunity that can be elicited by protein on recall. These outcomes support the possibility to design superparamagnetic nanoparticle-based DNA vaccines to optimally evoke desired antibody responses, useful for a variety of diseases including malaria.

  19. Single-Vector, Single-Injection Recombinant Vesicular Stomatitis Virus Vaccines Against High-Containment Viruses.

    PubMed

    Whitt, Michael A; Geisbert, Thomas W; Mire, Chad E

    2016-01-01

    There are many avenues for making an effective vaccine against viruses. Depending on the virus these can include one of the following: inactivation of whole virions; attenuation of viruses; recombinant viral proteins; non-replication-competent virus particles; or surrogate virus vector systems such as vesicular stomatitis virus (VSV). VSV is a prototypic enveloped animal virus that has been used for over four decades to study virus replication, entry, and assembly due to its ability to replicate to high titers in a wide variety of mammalian and insect cells. The use of reverse genetics to recover infectious and single-cycle replicating VSV from plasmid DNA transfected in cell culture began a revolution in the study of recombinant VSV (rVSV). This platform can be manipulated to study the viral genetic sequences and proteins important in the virus life cycle. Additionally, foreign genes can be inserted between naturally occurring or generated start/stop signals and polyadenylation sites within the VSV genome. VSV has a tolerance for foreign gene expression which has led to numerous rVSVs reported in the literature. Of particular interest are the very effective single-dose rVSV vaccine vectors against high-containment viruses such as filoviruses, henipaviruses, and arenaviruses. Herein we describe the methods for selecting foreign antigenic genes, selecting the location within the VSV genome for insertion, generation of rVSV using reverse genetics, and proper vaccine study designs.

  20. Evaluation of recombinant invasive, non-pathogenic Eschericia coli as a vaccine vector against the intracellular pathogen, Brucella

    PubMed Central

    Harms, Jerome S; Durward, Marina A; Magnani, Diogo M; Splitter, Gary A

    2009-01-01

    Background There is no safe, effective human vaccine against brucellosis. Live attenuated Brucella strains are widely used to vaccinate animals. However these live Brucella vaccines can cause disease and are unsafe for humans. Killed Brucella or subunit vaccines are not effective in eliciting long term protection. In this study, we evaluate an approach using a live, non-pathogenic bacteria (E. coli) genetically engineered to mimic the brucellae pathway of infection and present antigens for an appropriate cytolitic T cell response. Methods E. coli was modified to express invasin of Yersinia and listerialysin O (LLO) of Listeria to impart the necessary infectivity and antigen releasing traits of the intracellular pathogen, Brucella. This modified E. coli was considered our vaccine delivery system and was engineered to express Green Fluorescent Protein (GFP) or Brucella antigens for in vitro and in vivo immunological studies including cytokine profiling and cytotoxicity assays. Results The E. coli vaccine vector was able to infect all cells tested and efficiently deliver therapeutics to the host cell. Using GFP as antigen, we demonstrate that the E. coli vaccine vector elicits a Th1 cytokine profile in both primary and secondary immune responses. Additionally, using this vector to deliver a Brucella antigen, we demonstrate the ability of the E. coli vaccine vector to induce specific Cytotoxic T Lymphocytes (CTLs). Conclusion Protection against most intracellular bacterial pathogens can be obtained mostly through cell mediated immunity. Data presented here suggest modified E. coli can be used as a vaccine vector for delivery of antigens and therapeutics mimicking the infection of the pathogen and inducing cell mediated immunity to that pathogen. PMID:19126207

  1. New Viral Vector for Superproduction of Epitopes of Vaccine Proteins in Plants

    PubMed Central

    Tyulkina, L.G.; Skurat, E.V.; Frolova, O.Yu.; Komarova, T.V.; Karger, E.M.; Atabekov, I.G.

    2011-01-01

    The novel viral vectors PVX-CP AltMV and PVXdt-CP AltMV are superexpressors of the capsid protein (CP). These viral vectors were constructed on the basis of the potato virus X (PVX) genome andAlternantheramosaic virus (AltMV) CP gene. The expression, based on the hybrid viral vectors, is genetically safe, since the systemic transport and formation of infective viral particles are blocked. CP AltMV can self-assemble into virus-like particles (VLPs) in the absence of genomic RNA. The vectors can be used for the presentation of foreign peptides (including epitopes of human pathogens) on the surface of the VLP. The N-terminal extracellular domain (M2e) of the influenza virus A M2 protein and its truncated variant (ΔM2e) were used as model heterologous peptides for the construction of the chimeric CP AltMV. Chimeric CP AltMV retains its ability to self-assemble into VLP. The epitopes of the M2 influenza virus protein were not eliminated during the process of accumulation, polymerization and purification of chimeric VLP AltMV, providing evidence of the stability of chimeric VLP with C-terminal heterologous epitopes. It appears that VLP produced by the vectors PVX-CP AltMV and PVXdt-CP AltMV can be used in the field of biotechnology for the presentation of the epitopes of vaccine proteins on their surfaces. The chimeric VLP AltMV with the presented foreign epitopes can be used as candidate vaccines. PMID:22649706

  2. Plasmid DNA Vaccine vector design: impact on efficacy, safety and upstream production

    PubMed Central

    Williams, James A; Carnes, Aaron E; Hodgson, Clague P

    2009-01-01

    Critical molecular and cellular biological factors impacting design of licensable DNA vaccine vectors that combine high yield and integrity during bacterial production with increased expression in mammalian cells are reviewed. Food and Drug Administration (FDA), World Health Organization (WHO) and European Medical Agencies (EMEA) regulatory guidance’s are discussed, as they relate to vector design and plasmid fermentation. While all new vectors will require extensive preclinical testing to validate safety and performance prior to clinical use, regulatory testing burden for follow-on products can be reduced by combining carefully designed synthetic genes with existing validated vector backbones. A flowchart for creation of new synthetic genes, combining rationale design with bioinformatics, is presented. The biology of plasmid replication is reviewed, and process engineering strategies that reduce metabolic burden discussed. Utilizing recently developed low metabolic burden seed stock and fermentation strategies, optimized vectors can now be manufactured in high yields exceeding 2 g/L, with specific plasmid yields of 5% total dry cell weight. PMID:19233255

  3. Safety mechanism assisted by the repressor of tetracycline (SMART) vaccinia virus vectors for vaccines and therapeutics.

    PubMed

    Grigg, Patricia; Titong, Allison; Jones, Leslie A; Yilma, Tilahun D; Verardi, Paulo H

    2013-09-17

    Replication-competent viruses, such as Vaccinia virus (VACV), are powerful tools for the development of oncolytic viral therapies and elicit superior immune responses when used as vaccine and immunotherapeutic vectors. However, severe complications from uncontrolled viral replication can occur, particularly in immunocompromised individuals or in those with other predisposing conditions. VACVs constitutively expressing interferon-γ (IFN-γ) replicate in cell culture indistinguishably from control viruses; however, they replicate in vivo to low or undetectable levels, and are rapidly cleared even in immunodeficient animals. In an effort to develop safe and highly effective replication-competent VACV vectors, we established a system to inducibly express IFN-γ. Our SMART (safety mechanism assisted by the repressor of tetracycline) vectors are designed to express the tetracycline repressor under a constitutive VACV promoter and IFN-γ under engineered tetracycline-inducible promoters. Immunodeficient SCID mice inoculated with VACVs not expressing IFN-γ demonstrated severe weight loss, whereas those given VACVs expressing IFN-γ under constitutive VACV promoters showed no signs of infection. Most importantly, mice inoculated with a VACV expressing the IFN-γ gene under an inducible promoter remained healthy in the presence of doxycycline, but exhibited severe weight loss in the absence of doxycycline. In this study, we developed a safety mechanism for VACV based on the conditional expression of IFN-γ under a tightly controlled tetracycline-inducible VACV promoter for use in vaccines and oncolytic cancer therapies.

  4. Live attenuated rubella vectors expressing SIV and HIV vaccine antigens replicate and elicit durable immune responses in rhesus macaques

    PubMed Central

    2013-01-01

    Background Live attenuated viruses are among our most potent and effective vaccines. For human immunodeficiency virus, however, a live attenuated strain could present substantial safety concerns. We have used the live attenuated rubella vaccine strain RA27/3 as a vector to express SIV and HIV vaccine antigens because its safety and immunogenicity have been demonstrated in millions of children. One dose protects for life against rubella infection. In previous studies, rubella vectors replicated to high titers in cell culture while stably expressing SIV and HIV antigens. Their viability in vivo, however, as well as immunogenicity and antibody persistence, were unknown. Results This paper reports the first successful trial of rubella vectors in rhesus macaques, in combination with DNA vaccines in a prime and boost strategy. The vectors grew robustly in vivo, and the protein inserts were highly immunogenic. Antibody titers elicited by the SIV Gag vector were greater than or equal to those elicited by natural SIV infection. The antibodies were long lasting, and they were boosted by a second dose of replication-competent rubella vectors given six months later, indicating the induction of memory B cells. Conclusions Rubella vectors can serve as a vaccine platform for safe delivery and expression of SIV and HIV antigens. By presenting these antigens in the context of an acute infection, at a high level and for a prolonged duration, these vectors can stimulate a strong and persistent immune response, including maturation of memory B cells. Rhesus macaques will provide an ideal animal model for demonstrating immunogenicity of novel vectors and protection against SIV or SHIV challenge. PMID:24041113

  5. Candidate vaccine against botulinum neurotoxin serotype A derived from a Venezuelan equine encephalitis virus vector system.

    PubMed

    Lee, J S; Pushko, P; Parker, M D; Dertzbaugh, M T; Smith, L A; Smith, J F

    2001-09-01

    A candidate vaccine against botulinum neurotoxin serotype A (BoNT/A) was developed by using a Venezuelan equine encephalitis (VEE) virus replicon vector. This vaccine vector is composed of a self-replicating RNA containing all of the VEE nonstructural genes and cis-acting elements and also a heterologous immunogen gene placed downstream of the subgenomic 26S promoter in place of the viral structural genes. In this study, the nontoxic 50-kDa carboxy-terminal fragment (H(C)) of the BoNT/A heavy chain was cloned into the replicon vector (H(C)-replicon). Cotransfection of BHK cells in vitro with the H(C)-replicon and two helper RNA molecules, the latter encoding all of the VEE structural proteins, resulted in the assembly and release of propagation-deficient, H(C) VEE replicon particles (H(C)-VRP). Cells infected with H(C)-VRP efficiently expressed this protein when analyzed by either immunofluorescence or by Western blot. To evaluate the immunogenicity of H(C)-VRP, mice were vaccinated with various doses of H(C)-VRP at different intervals. Mice inoculated subcutaneously with H(C)-VRP were protected from an intraperitoneal challenge of up to 100,000 50% lethal dose units of BoNT/A. Protection correlated directly with serum enzyme-linked immunosorbent assay titers to BoNT/A. The duration of the immunity achieved was tested at 6 months and at 1 year postvaccination, and mice challenged at these times remained refractory to challenge with BoNT/A.

  6. Effective induction of high-titer antibodies by viral vector vaccines.

    PubMed

    Draper, Simon J; Moore, Anne C; Goodman, Anna L; Long, Carole A; Holder, Anthony A; Gilbert, Sarah C; Hill, Fergal; Hill, Adrian V S

    2008-08-01

    Protein-in-adjuvant vaccines have shown limited success against difficult diseases such as blood-stage malaria. Here we show that a recombinant adenovirus-poxvirus prime-boost immunization regime (known to induce strong T cell immunogenicity) can also induce very strong antigen-specific antibody responses, and we identify a simple complement-based adjuvant to further enhance immunogenicity. Antibodies induced against a blood-stage malaria antigen by this viral vector platform are highly effective against Plasmodium yoelii parasites in mice and against Plasmodium falciparum in vitro.

  7. Engineering human rhinovirus serotype-A1 as a vaccine vector.

    PubMed

    Tomusange, Khamis; Yu, Wenbo; Suhrbier, Andreas; Wijesundara, Danushka; Grubor-Bauk, Branka; Gowans, Eric J

    2015-05-04

    Herein we describe the construction of recombinant human rhinoviruses (rHRVs) encoding HIV Gag or Tat by inserting the full length tat gene or regions of the gag gene flanked by sequences encoding the HRV 2A protease cleavage site into the junction between HRV genes encoding structural (P1) and non-structural (P2) proteins. Most recombinants were unstable, but this was corrected by mutation of the flanking cleavage sites. Thereafter, all rHRV constructs retained the inserts throughout six passages. Such constructs may find utility as vaccine vectors to generate mucosal immunity.

  8. Development of oral CTL vaccine using a CTP-integrated Sabin 1 poliovirus-based vector system.

    PubMed

    Han, Seung-Soo; Lee, Jinjoo; Jung, Yideul; Kang, Myeong-Ho; Hong, Jung-Hyub; Cha, Min-Suk; Park, Yu-Jin; Lee, Ezra; Yoon, Cheol-Hee; Bae, Yong-Soo

    2015-09-11

    We developed a CTL vaccine vector by modification of the RPS-Vax system, a mucosal vaccine vector derived from a poliovirus Sabin 1 strain, and generated an oral CTL vaccine against HIV-1. A DNA fragment encoding a cytoplasmic transduction peptide (CTP) was integrated into the RPS-Vax system to generate RPS-CTP, a CTL vaccine vector. An HIV-1 p24 cDNA fragment was introduced into the RPS-CTP vector system and a recombinant poliovirus (rec-PV) named vRPS-CTP/p24 was produced. vRPS-CTP/p24 was genetically stable and efficiently induced Th1 immunity and p24-specific CTLs in immunized poliovirus receptor-transgenic (PVR-Tg) mice. In challenge experiments, PVR-Tg mice that were pre-immunized orally with vRPS-CTP/p24 were resistant to challenge with a lethal dose of p24-expressing recombinant vaccinia virus (rMVA-p24). These results suggested that the RPS-CTP vector system had potential for developing oral CTL vaccines against infectious diseases.

  9. PAMAM-Lys, a Novel Vaccine Delivery Vector, Enhances the Protective Effects of the SjC23 DNA Vaccine against Schistosoma japonicum Infection

    PubMed Central

    Wang, Xiaoting; Dai, Yang; Zhao, Song; Tang, Jianxia; Li, Hongjun; Xing, Yuntian; Qu, Guoli; Li, Xinsong; Dai, Jianrong; Zhu, Yinchang; Zhang, Xueguang

    2014-01-01

    Background Schistosomiasis japonica remains a major public-health concern in China. Praziquantel-based chemotherapy effectively reduces both infections and intensity; however, it can not prevent re-infection. Furthermore, there is an increasing concern about praziquantel resistance following long-term repeated use of the drug in endemic areas. Therefore, development of a schistosomiasis vaccine, as a strategy to prevent and control schistosomiasis japonica, has been given high priority. The present study was conducted to develop PAMAM dendrimers as a novel vaccine delivery vector for a schistosomiasis japonica DNA vaccine and evaluate its ability to enhance protective effects against Schistosoma japonicum infection. Methodology/Principal Findings Lysine was used to modify 4.0G PAMAM, and the modified product PAMAM-Lys was synthesized. PAMAM-Lys showed both high transfection and low cytotocity for gene delivery in vitro. DNA vaccines combined with PAMAM-Lys produced higher level of protection compare with naked DNA vaccines against S. japonicum infection in a mouse model. Futhermore,antibodies from mice immunized with PAMAM-Lys combined DNA vaccines were significantly higher than those of mice immunized with the naked DNA vaccines. The PAMAM-Lys vector elicited a predominantly IgG2a antibody response and a tremendously increase in the production of IL-2 and IFN-γ. Conclusion/Significance Lysine-modified PAMAM-Lys is an excellent vector. PAMAM-Lys may enhance the immunoreactivity of DNA vaccine and increase the protective effect of the SjC23 DNA vaccine against S. japonicum infection. PMID:24497955

  10. Transmission potential of two chimeric Chikungunya vaccine candidates in the urban mosquito vectors, Aedes aegypti and Ae. albopictus.

    PubMed

    Darwin, Justin R; Kenney, Joan L; Weaver, Scott C

    2011-06-01

    Chikungunya virus (CHIKV) is an emerging, mosquito-borne alphavirus that has caused major epidemics in Africa and Asia. We developed chimeric vaccine candidates using the non-structural protein genes of either Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain TC-83 or a naturally attenuated strain of eastern equine encephalitis virus (EEEV) and the structural genes of CHIKV. Because the transmission of genetically modified live vaccine strains is undesirable because of the potentially unpredictable evolution of these viruses as well as the potential for reversion, we evaluated the ability of these vaccines to infect the urban CHIKV vectors, Aedes aegypti and Ae. albopictus. Both vaccine candidates exhibited significantly lower infection and dissemination rates compared with the parent alphaviruses. Intrathoracic inoculations indicated that reduced infectivity was mediated by midgut infection barriers in both species. These results indicate a low potential for transmission of these vaccine strains in the event that a vaccinee became viremic.

  11. Topical Application of Escherichia coli-Vectored Vaccine as a Simple Method for Eliciting Protective Immunity

    PubMed Central

    Zhang, Jianfeng; Shi, Zhongkai; Kong, Fan-kun; Jex, Edward; Huang, Zhigang; Watt, James M.; Van Kampen, Kent R.; Tang, De-chu C.

    2006-01-01

    We report here that animals can be protected against lethal infection by Clostridium tetani cells and Bacillus anthracis spores following topical application of intact particles of live or γ-irradiated Escherichia coli vectors overproducing tetanus and anthrax antigens, respectively. Cutaneous γδT cells were rapidly recruited to the administration site. Live E. coli cells were not found in nonskin tissues after topical application, although fragments of E. coli DNA were disseminated transiently. Evidence suggested that intact E. coli particles in the outer layer of skin may be disrupted by a γδT-cell-mediated innate defense mechanism, followed by the presentation of E. coli ligand-adjuvanted intravector antigens to the immune system and rapid degradation of E. coli components. The nonreplicating E. coli vector overproducing an exogenous immunogen may foster the development of a new generation of vaccines that can be manufactured rapidly and administered noninvasively in a wide variety of disease settings. PMID:16714593

  12. Vaccination of rabbits with an adenovirus vector expressing the papillomavirus E2 protein leads to clearance of papillomas and infection.

    PubMed

    Brandsma, Janet L; Shlyankevich, Mark; Zhang, Lixin; Slade, Martin D; Goodwin, Edward C; Peh, Woei; Deisseroth, Albert B

    2004-01-01

    Cervical cancer arises from lesions caused by infection with high-risk types of human papillomavirus (HPV). Therefore, vaccination against HPV could prevent carcinogenesis by preventing HPV infection or inducing lesion regression. HPV E2 protein is an attractive candidate for vaccine development because it is required for papilloma formation, is involved in all stages of the virus life cycle, and is expressed in all premalignant lesions as well as some cancers. This study reports vaccination against E2 protein using a rabbit model of papillomavirus infection. A recombinant adenovirus (Ad) vector expressing the E2 protein of cottontail rabbit papillomavirus (CRPV) was tested for therapeutic efficacy in CRPV-infected rabbits. Primary immunization with the Ad-E2 vaccine, compared to immunization with a control Ad vector, reduced the number of papilloma-forming sites from 17 of 45 to 4 of 45. After booster immunization, vaccinated rabbits formed no new papillomas versus an additional 23 papillomas in rabbits that received the control vector. Papillomas in the Ad-E2 vaccinees were significantly smaller than those in the control rabbits, and all four papillomas in the Ad-E2 vaccinated rabbits regressed. No CRPV DNA was detected either in the regression sites or in sites that did not form papillomas, indicating that the vaccination led to clearance of CRPV from all infected sites.

  13. Vaccination with Lentiviral Vector Expressing the nfa1 Gene Confers a Protective Immune Response to Mice Infected with Naegleria fowleri

    PubMed Central

    Kim, Jong-Hyun; Sohn, Hae-Jin; Lee, Jinyoung; Yang, Hee-Jong; Chwae, Yong-Joon; Kim, Kyongmin; Park, Sun

    2013-01-01

    Naegleria fowleri, a pathogenic free-living amoeba, causes fatal primary amoebic meningoencephalitis (PAM) in humans and animals. The nfa1 gene (360 bp), cloned from a cDNA library of N. fowleri, produces a 13.1-kDa recombinant protein which is located on pseudopodia, particularly the food cup structure. The nfa1 gene plays an important role in the pathogenesis of N. fowleri infection. To examine the effect of nfa1 DNA vaccination against N. fowleri infection, we constructed a lentiviral vector (pCDH) expressing the nfa1 gene. For the in vivo mouse study, BALB/c mice were intranasally vaccinated with viral particles of a viral vector expressing the nfa1 gene. To evaluate the effect of vaccination and immune responses of mice, we analyzed the IgG levels (IgG, IgG1, and IgG2a), cytokine induction (interleukin-4 [IL-4] and gamma interferon [IFN-γ]), and survival rates of mice that developed PAM. The levels of both IgG and IgG subclasses (IgG1 and IgG2a) in vaccinated mice were significantly increased. The cytokine analysis showed that vaccinated mice exhibited greater IL-4 and IFN-γ production than the other control groups, suggesting a Th1/Th2 mixed-type immune response. In vaccinated mice, high levels of Nfa1-specific IgG antibodies continued until 12 weeks postvaccination. The mice vaccinated with viral vector expressing the nfa1 gene also exhibited significantly higher survival rates (90%) after challenge with N. fowleri trophozoites. Finally, the nfa1 vaccination effectively induced protective immunity by humoral and cellular immune responses in N. fowleri-infected mice. These results suggest that DNA vaccination using a viral vector may be a potential tool against N. fowleri infection. PMID:23677321

  14. Onset and long-term duration of immunity provided by a single vaccination with a turkey herpesvirus vector ND vaccine in commercial layers.

    PubMed

    Palya, Vilmos; Tatár-Kis, Tímea; Mató, Tamás; Felföldi, Balázs; Kovács, Edit; Gardin, Yannick

    2014-03-15

    The onset and duration of immunity provided by a recombinant ND vaccine using HVT virus as vector (rHVT-ND) was followed up to 72 weeks of age in commercial layer chickens after single application or as part of two different vaccination regimes including conventional live and killed ND vaccines. Efficacy of the different vaccination programmes was checked, from 3 to 72 weeks of age, by serology as well as by challenges with a recent velogenic NDV isolate belonging to genotype VII. Assessment of protection was done based on the prevention of clinical signs and reduction of challenge virus shedding via the oro-nasal and cloacal routes. Single vaccination with the rHVT-ND vaccine at one day of age provided complete or almost complete (95-100%) clinical protection against NDV challenges from 4 weeks of age up to 72 weeks of age when the latest challenge was done. Shedding of challenge virus both by the oro-nasal and cloacal route was significantly reduced compared to the controls. Booster vaccination of rHVT-ND vaccinated birds with conventional ND vaccines significantly increased the level of anti-NDV serum antibodies and further reduced the oro-nasal excretion of challenge virus. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Lac-regulated system for generating adenovirus 5 vaccine vectors expressing cytolytic human immunodeficiency virus 1 genes.

    PubMed

    Zhao, Chunxia; Crews, Charles Jefferson; Derdeyn, Cynthia A; Blackwell, Jerry L

    2009-09-01

    Adenovirus (Ad) vectors have been developed as human immunodeficiency-1 (HIV-1) vaccine vectors because they consistently induce immune responses in preclinical animal models and human trials. Strong promoters and codon-optimization are often used to enhance vaccine-induced HIV-1 gene expression and immunogenicity. However, if the transgene is inherently cytotoxic in the cell line used to produce the vector, and is expressed at high levels, it is difficult to rescue a stable Ad HIV-1 vaccine vector. Therefore we hypothesized that generation of Ad vaccine vectors expressing cytotoxic genes, such as HIV-1 env, would be more efficient if expression of the transgene was down-regulated during Ad rescue. To test this hypothesis, a Lac repressor-operator system was applied to regulate expression of reporter luciferase and HIV-1 env transgenes during Ad rescue. The results demonstrate that during Ad rescue, constitutive expression of the Lac repressor in 293 cells reduced transgene expression levels to approximately 5% of that observed in the absence of regulation. Furthermore, Lac-regulation translated into more efficient Ad rescue compared to traditional 293 cells. Importantly, Ad vectors rescued with this system showed high levels of transgene expression when transduced into cells that lack the Lac repressor protein. The Lac-regulated system also facilitated the rescue of modified Ad vectors that have non-native receptor tropism. These tropism-modified Ad vectors infect a broader range of cell types than the unmodified Ad, which could increase their effectiveness as a vaccine vector. Overall, the Lac-regulated system described here (i) is backwards compatible with Ad vector methods that employ bacterial-mediated homologous recombination, (ii) is adaptable for the engineering of tropism-modified Ad vectors, and (iii) does not require co-expression of regulatory genes from the vector or the addition of exogenous chemicals to induce or repress transgene expression. This

  16. Enhanced potency of replicon vaccine using one vector to simultaneously co-express antigen and interleukin-4 molecular adjuvant

    PubMed Central

    Ma, Yao; An, Huai-Jie; Wei, Xiao-Qi; Xu, Qing; Yu, Yun-Zhou; Sun, Zhi-Wei

    2013-01-01

    We evaluated the utility of interleukin-4 (IL-4) as molecular adjuvant of replicon vaccines for botulinum neurotoxin serotype A (BoNT/A) in mouse model. In both Balb/c and C57/BL6 mice that received the plasmid DNA replicon vaccines derived from Semliki Forest virus (SFV) encoding the Hc gene of BoNT/A (AHc), the immunogenicity was significantly modulated and enhanced by co-delivery or co-express of the IL-4 molecular adjuvant. The enhanced potencies were also produced by co-delivery or co-expression of the IL-4 molecular adjuvant in mice immunized with the recombinant SFV replicon particles (VRP) vaccines. In particular, when AHc and IL-4 were co-expressed within the same replicon vaccine vector using dual-expression or bicistronic IRES, the anti-AHc antibody titers, serum neutralization titers and survival rates of immunized mice after challenged with BoNT/A were significantly increased. These results indicate IL-4 is an effective Th2-type adjuvant for the replicon vaccines in both strain mice, and the co-expression replicon vaccines described here may be an excellent candidate for further vaccine development in other animals or humans. Thus, we described a strategy to design and develop efficient vaccines against BoNT/A or other pathogens using one replicon vector to simultaneously co-express antigen and molecular adjuvant. PMID:23291932

  17. Defective interfering viruses and their impact on vaccines and viral vectors.

    PubMed

    Frensing, Timo

    2015-05-01

    Defective interfering particles (DIPs) have been found for many important viral pathogens and it is believed that most viruses generate DIPs. This article reviews the current knowledge of the generation and amplification of DIPs, which possess deletions in the viral genome but retain the ability to replicate in the presence of a complete helper virus. In addition, mechanisms are discussed by which DIPs interfere with the replication of their helper virus leading to the production of mainly progeny DIPs by coinfected cells. Even though DIPs cannot replicate on their own, they are biologically active and it is well known that they have a huge impact on virus replication, evolution, and pathogenesis. Moreover, defective genomes are potent inducers of the innate immune response. Yet, little attention has been paid to DIPs in recent years and their impact on biotechnological products such as vaccines and viral vectors remains elusive in most cases. With a focus on influenza virus, this review demonstrates that DIPs are important for basic research on viruses and for the production of viral vaccines and vectors. Reducing the generation and/or amplification of DIPs ensures reproducible results as well as high yields and consistent product quality in virus production.

  18. Evaluation of a Fiber-Modified Adenovirus Vector Vaccine against Foot-and-Mouth Disease in Cattle.

    PubMed

    Medina, Gisselle N; Montiel, Nestor; Diaz-San Segundo, Fayna; Sturza, Diego; Ramirez-Medina, Elizabeth; Grubman, Marvin J; de los Santos, Teresa

    2015-11-25

    Novel vaccination approaches against foot-and-mouth disease (FMD) include the use of replication-defective human adenovirus type 5 (Ad5) vectors that contain the capsid-encoding regions of FMD virus (FMDV). Ad5 containing serotype A24 capsid sequences (Ad5.A24) has proved to be effective as a vaccine against FMD in livestock species. However, Ad5-vectored FMDV serotype O1 Campos vaccine (Ad5.O1C.2B) provides only partial protection of cattle against homologous challenge. It has been reported that a fiber-modified Ad5 vector expressing Arg-Gly-Asp (RGD) enhances transduction of antigen-presenting cells (APC) in mice. In the current study, we assessed the efficacy of a fiber-modified Ad5 (Adt.O1C.2B.RGD) in cattle. Expression of FMDV capsid proteins was superior in cultured cells infected with the RGD-modified vector. Furthermore, transgene expression of Adt.O1C.2B.RGD was enhanced in cell lines that constitutively express integrin αvβ6, a known receptor for FMDV. In contrast, capsid expression in cattle-derived enriched APC populations was not enhanced by infection with this vector. Our data showed that vaccination with the two vectors yielded similar levels of protection against FMD in cattle. Although none of the vaccinated animals had detectable viremia, FMDV RNA was detected in serum samples from animals with clinical signs. Interestingly, CD4(+) and CD8(+) gamma interferon (IFN-γ)(+) cell responses were detected at significantly higher levels in animals vaccinated with Adt.O1C.2B.RGD than in animals vaccinated with Ad5.O1C.2B. Our results suggest that inclusion of an RGD motif in the fiber of Ad5-vectored FMD vaccine improves transgene delivery and cell-mediated immunity but does not significantly enhance vaccine performance in cattle. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  19. Rabies challenge of captive striped skunks (Mephitis mephitis) following oral administration of a live vaccinia-vectored rabies vaccine.

    PubMed

    Grosenbaugh, Deborah A; Maki, Joanne L; Rupprecht, Charles E; Wall, Debra K

    2007-01-01

    Twenty-four adult striped skunks (Mephitis mephitis) were administered the raccoon product formulation of Rabies Vaccine, Live Vaccinia-Vectored (Raboral V-RG, Merial Limited, Athens, Georgia, USA), either by oral instillation or in vaccine-filled coated sachets either as single or multiple doses. A control group remained unvaccinated. Twenty-three of the skunks were challenged 116 days postvaccination with rabies virus (skunk isolate). Six of six naive skunks succumbed to challenge. Four of six skunks that received the vaccine by oral instillation survived challenge. The skunks that did not survive failed to seroconvert following vaccination. None of the skunks that accepted multiple doses of the vaccine offered in coated sachets survived challenge, nor were rabies virus-neutralizing antibodies (VNAs) detected in the sera. Likewise, none of the five skunks ingesting a single sachet developed VNA against rabies. However, in this group one skunk did survive rabies challenge. This preliminary study showed that the vaccinia-vectored oral rabies vaccine Raboral V-RG, as formulated for use in raccoons, is capable of protecting a percentage of skunks against rabies. However, although the fishmeal-coated sachets were readily consumed, subsequent challenge of these animals revealed poor vaccine delivery efficiency.

  20. Robust vaccine-elicited cellular immune responses in breast milk following systemic simian immunodeficiency virus DNA prime and live virus vector boost vaccination of lactating rhesus monkeys.

    PubMed

    Wilks, Andrew B; Christian, Elizabeth C; Seaman, Michael S; Sircar, Piya; Carville, Angela; Gomez, Carmen E; Esteban, Mariano; Pantaleo, Giuseppe; Barouch, Dan H; Letvin, Norman L; Permar, Sallie R

    2010-12-01

    Breast milk transmission of HIV remains an important mode of infant HIV acquisition. Enhancement of mucosal HIV-specific immune responses in milk of HIV-infected mothers through vaccination may reduce milk virus load or protect against virus transmission in the infant gastrointestinal tract. However, the ability of HIV/SIV strategies to induce virus-specific immune responses in milk has not been studied. In this study, five uninfected, hormone-induced lactating, Mamu A*01(+) female rhesus monkey were systemically primed and boosted with rDNA and the attenuated poxvirus vector, NYVAC, containing the SIVmac239 gag-pol and envelope genes. The monkeys were boosted a second time with a recombinant Adenovirus serotype 5 vector containing matching immunogens. The vaccine-elicited immunodominant epitope-specific CD8(+) T lymphocyte response in milk was of similar or greater magnitude than that in blood and the vaginal tract but higher than that in the colon. Furthermore, the vaccine-elicited SIV Gag-specific CD4(+) and CD8(+) T lymphocyte polyfunctional cytokine responses were more robust in milk than in blood after each virus vector boost. Finally, SIV envelope-specific IgG responses were detected in milk of all monkeys after vaccination, whereas an SIV envelope-specific IgA response was only detected in one vaccinated monkey. Importantly, only limited and transient increases in the proportion of activated or CCR5-expressing CD4(+) T lymphocytes in milk occurred after vaccination. Therefore, systemic DNA prime and virus vector boost of lactating rhesus monkeys elicits potent virus-specific cellular and humoral immune responses in milk and may warrant further investigation as a strategy to impede breast milk transmission of HIV.

  1. Simian immunodeficiency virus-Vpx for improving integrase defective lentiviral vector-based vaccines

    PubMed Central

    2012-01-01

    Background Integrase defective lentiviral vectors (IDLV) represent a promising delivery system for immunization purposes. Human dendritic cells (DC) are the main cell types mediating the immune response and are readily transduced by IDLV, allowing effective triggering of in vitro expansion of antigen-specific primed CD8+ T cells. However, IDLV expression in transduced DC is at lower levels than those of the integrase (IN) competent counterpart, thus requiring further improvement of IDLV for future use in the clinic. Results In this paper we show that the addition of simian immunodeficiency (SIV)-Vpx protein in the vector preparation greatly improves transduction of human and simian DC, but not of murine DC, thus increasing the ability of transduced DC to act as functional antigen presenting cells, in the absence of integrated vector sequences. Importantly, the presence of SIV-Vpx allows for using lower dose of input IDLV during in vitro transduction, thus further improving the IDLV safety profile. Conclusions These results have significant implications for the development of IDLV-based vaccines. PMID:22913641

  2. Immunogenicity of bivalent human papillomavirus DNA vaccine using human endogenous retrovirus envelope-coated baculoviral vectors in mice and pigs.

    PubMed

    Lee, Hee-Jung; Hur, Yoon-Ki; Cho, Youn-Dong; Kim, Mi-Gyeong; Lee, Hoon-Taek; Oh, Yu-Kyoung; Kim, Young Bong

    2012-01-01

    Human papillomavirus is known to be the major pathogen of cervical cancer. Here, we report the efficacy of a bivalent human papillomavirus type 16 and 18 DNA vaccine system following repeated dosing in mice and pigs using a recombinant baculovirus bearing human endogenous retrovirus envelope protein (AcHERV) as a vector. The intramuscular administration of AcHERV-based HPV16L1 and HPV18L1 DNA vaccines induced antigen-specific serum IgG, vaginal IgA, and neutralizing antibodies to levels comparable to those achieved using the commercially marketed vaccine Cervarix. Similar to Cervarix, AcHERV-based bivalent vaccinations completely blocked subsequent vaginal challenge with HPV type-specific pseudovirions. However, AcHERV-based bivalent vaccinations induced significantly higher cell-mediated immune responses than Cervarix, promoting 4.5- (HPV16L1) and 3.9-(HPV18L1) fold higher interferon-γ production in splenocytes upon stimulation with antigen type-specific pseudovirions. Repeated dosing did not affect the immunogenicity of AcHERV DNA vaccines. Three sequential immunizations with AcHERV-HP18L1 DNA vaccine followed by three repeated dosing with AcHERV-HP16L1 over 11 weeks induced an initial production of anti-HPV18L1 antibody followed by subsequent induction of anti-HPV16L1 antibody. Finally, AcHERV-based bivalent DNA vaccination induced antigen-specific serum IgG immune responses in pigs. These results support the further development of AcHERV as a bivalent human papillomavirus DNA vaccine system for use in preventing the viral infection as well as treating the infected women by inducing both humoral and cell-mediated immune responses. Moreover, the possibility of repeated dosing indicates the utility of AcHERV system for reusable vectors of other viral pathogen vaccines.

  3. Vaccination With a Highly Attenuated Recombinant Vesicular Stomatitis Virus Vector Protects Against Challenge With a Lethal Dose of Ebola Virus

    PubMed Central

    Matassov, Demetrius; Marzi, Andrea; Latham, Terri; Xu, Rong; Ota-Setlik, Ayuko; Feldmann, Friederike; Geisbert, Joan B.; Mire, Chad E.; Hamm, Stefan; Nowak, Becky; Egan, Michael A.; Geisbert, Thomas W.; Eldridge, John H.; Feldmann, Heinz; Clarke, David K.

    2015-01-01

    Previously, recombinant vesicular stomatitis virus (rVSV) pseudotypes expressing Ebolavirus glycoproteins (GPs) in place of the VSV G protein demonstrated protection of nonhuman primates from lethal homologous Ebolavirus challenge. Those pseudotype vectors contained no additional attenuating mutations in the rVSV genome. Here we describe rVSV vectors containing a full complement of VSV genes and expressing the Ebola virus (EBOV) GP from an additional transcription unit. These rVSV vectors contain the same combination of attenuating mutations used previously in the clinical development pathway of an rVSV/human immunodeficiency virus type 1 vaccine. One of these rVSV vectors (N4CT1-EBOVGP1), which expresses membrane-anchored EBOV GP from the first position in the genome (GP1), elicited a balanced cellular and humoral GP-specific immune response in mice. Guinea pigs immunized with a single dose of this vector were protected from any signs of disease following lethal EBOV challenge, while control animals died in 7–9 days. Subsequently, N4CT1-EBOVGP1 demonstrated complete, single-dose protection of 2 macaques following lethal EBOV challenge. A single sham-vaccinated macaque died from disease due to EBOV infection. These results demonstrate that highly attenuated rVSV vectors expressing EBOV GP may provide safer alternatives to current EBOV vaccines. PMID:26109675

  4. Vaccination With a Highly Attenuated Recombinant Vesicular Stomatitis Virus Vector Protects Against Challenge With a Lethal Dose of Ebola Virus.

    PubMed

    Matassov, Demetrius; Marzi, Andrea; Latham, Terri; Xu, Rong; Ota-Setlik, Ayuko; Feldmann, Friederike; Geisbert, Joan B; Mire, Chad E; Hamm, Stefan; Nowak, Becky; Egan, Michael A; Geisbert, Thomas W; Eldridge, John H; Feldmann, Heinz; Clarke, David K

    2015-10-01

    Previously, recombinant vesicular stomatitis virus (rVSV) pseudotypes expressing Ebolavirus glycoproteins (GPs) in place of the VSV G protein demonstrated protection of nonhuman primates from lethal homologous Ebolavirus challenge. Those pseudotype vectors contained no additional attenuating mutations in the rVSV genome. Here we describe rVSV vectors containing a full complement of VSV genes and expressing the Ebola virus (EBOV) GP from an additional transcription unit. These rVSV vectors contain the same combination of attenuating mutations used previously in the clinical development pathway of an rVSV/human immunodeficiency virus type 1 vaccine. One of these rVSV vectors (N4CT1-EBOVGP1), which expresses membrane-anchored EBOV GP from the first position in the genome (GP1), elicited a balanced cellular and humoral GP-specific immune response in mice. Guinea pigs immunized with a single dose of this vector were protected from any signs of disease following lethal EBOV challenge, while control animals died in 7-9 days. Subsequently, N4CT1-EBOVGP1 demonstrated complete, single-dose protection of 2 macaques following lethal EBOV challenge. A single sham-vaccinated macaque died from disease due to EBOV infection. These results demonstrate that highly attenuated rVSV vectors expressing EBOV GP may provide safer alternatives to current EBOV vaccines.

  5. Influenza viral vectors expressing the Brucella OMP16 or L7/L12 proteins as vaccines against B. abortus infection

    PubMed Central

    2014-01-01

    Background We generated novel, effective candidate vaccine against Brucella abortus based on recombinant influenza viruses expressing the Brucella ribosomal protein L7/L12 or outer membrane protein (Omp)-16 from the NS1 open reading frame. The main purpose of this work was to evaluate the safety, immunogenicity and protectiveness of vaccine candidate in laboratory animals. Methods and Results Four recombinant influenza A viral constructs of the subtypes Н5N1 or H1N1 expressing the Brucella proteins L7/L12 or Omp16 were obtained by a reverse genetics method: Flu-NS1-124-L7/L12-H5N1, Flu-NS1-124-Omp16-H5N1, Flu-NS1-124-L7/L12-H1N1 and Flu-NS1-124-Omp16-H1N1. Despite of substantial modification of NS1 gene, all constructs replicated well and were retain their Brucella inserts over five passages in embryonated chicken eggs (CE). Administration of the mono- or bivalent vaccine formulation via prime-boost intranasal (i.n.), conjunctival (c.) or subcutaneous (s.c.) immunization was safe in mice; no deaths, body weight loss or pathomorphological changes were observed over 56 days. Moreover, guinea pigs vaccinated i.n. with vaccine vectors did not shed the vaccine viruses through their upper respiratory tract after the prime and booster vaccination. These findings confirmed the replication-deficient phenotype of viral vectors. The highest antibody response to Brucella antigen was obtained with constructs expressing L7/L12 (ELISA, GMT 242.5-735.0); whereas the highest T-cell immune response- with construct expressing Omp16 (ELISPOT, 337 ± 52-651 ± 45 spots/4×105cells), which was comparable (P > 0.05) to the response induced by the commercial vaccine B. abortus 19. Interestingly, c. immunization appeared to be optimal for eliciting T-cell immune response. In guinea pigs, the highest protective efficacy after challenge with B. abortus 544 was achieved with Omp16 expressing constructs in both monovalent or bivalent vaccine formulations; protective efficacy was

  6. Multiagent Vaccines Vectored by Venezuelan Equine Encephalitis Virus Replicon Elicits Immune Responses to Marburg Virus and Protection Against Anthrax and Botulinum Neurotoxin in Mice

    DTIC Science & Technology

    2006-01-01

    formulations of individual Venezuelan equine encephalitis (VEE) virus replicon- vectored vaccines against a bacterial disease, anthrax; a viral disease...here the results of using formulations of individual Venezuelan equine encephalitis (VEE) virus replicon-vectored vaccines against a bacterial disease...on days 0, 35, and 70 with the indicated vaccines. Ne b Infectious units were used to measure VRP and milliliters were used to measur c The

  7. Vaccine protection of chickens against antigenically diverse H5 highly pathogenic avian influenza isolates with a live HVT vector vaccine expressing the influenza hemagglutinin gene derived from a clade 2.2 avian influenza vi

    USDA-ARS?s Scientific Manuscript database

    Vaccination is an important tool in the protection of poultry against avian influenza (AI). For field use, the overwhelming majority of AI vaccines produced are inactivated whole virus formulated into an oil emulsion. However, recombinant vectored vaccines are gaining use for their ability to induce...

  8. Encapsulation of adenoviral vectors into chitosan-bile salt microparticles for mucosal vaccination.

    PubMed

    Lameiro, Maria Helena; Malpique, Rita; Silva, Ana Carina; Alves, Paula M; Melo, Eurico

    2006-11-01

    The objective of this study is the incorporation of adenoviral vectors into a microparticulate system adequate for mucosal delivery. Microencapsulation of the vectors was accomplished by ionotropic coacervation of chitosan, using bile salts as counter-anion. The process was optimized in order to promote high encapsulation efficiency, with a minimal loss of viral infectivity. The maintenance of sterility during all the encapsulation procedure was also taken into account. The principle relies on the simple addition of a solution containing adenoviral vectors to a solution of neutralized chitosan, under stirring. Some surfactants were added to the chitosan solution, to improve the efficiency of this process, such as Tween 80, and Pluronic F68 at 1% (w/v). Encapsulation efficiency higher than 84% was achieved with formulations containing sodium deoxycholate as counter-anion and Pluronic F68 as dispersant agent. The infectivity of the adenoviral vectors incorporated into microparticles was assessed by release assays in PBS and by direct inoculation in 293 and Caco-2 cells. The release in aqueous media was negligible but, when in contact with monolayers of the cells, an effective release of bioactive adenovirus was obtained. Our work shows that encapsulation in microparticles, not only appear to protect the adenovirus from the external medium, namely from low pH, but can also delay their release that is fully dependent on cell contact, an advantage for mucosal vaccination purposes. The formulations developed are able to maintain AdV infectivity and permit a delayed release of the bioactives that is promoted by digestion in situ of the microparticles by the cell monolayers. The onset of delivery is, that way, host-controlled. In view of these results, these formulations showed good properties for mucosal adenovirus delivery.

  9. A Single-Vector, Single-Injection Trivalent Filovirus Vaccine: Proof of Concept Study in Outbred Guinea Pigs.

    PubMed

    Mire, Chad E; Geisbert, Joan B; Versteeg, Krista M; Mamaeva, Natalia; Agans, Krystle N; Geisbert, Thomas W; Connor, John H

    2015-10-01

    The filoviruses, Marburg marburgvirus (MARV), Zaire ebolavirus (ZEBOV), and Sudan ebolavirus (SEBOV), cause severe and often fatal hemorrhagic fever in humans and nonhuman primates (NHPs). Monovalent recombinant vesicular stomatitis virus (rVSV)-based vaccine vectors, which encode a filovirus glycoprotein (GP) in place of the VSV glycoprotein, have shown 100% efficacy against homologous filovirus challenge in rodent and NHP studies. Here, we examined the utility of a single-vector, single-injection trivalent rVSV vector expressing MARV, ZEBOV, and SEBOV GPs to protect against MARV-, ZEBOV-, and SEBOV-induced disease in outbred Hartley guinea pigs where we observed protection from effects of all 3 filoviruses.

  10. P and M gene junction is the optimal insertion site in Newcastle disease virus vaccine vector for foreign gene expression

    USDA-ARS?s Scientific Manuscript database

    Newcastle disease virus (NDV) has been developed as a vector for vaccine and gene therapy purposes. However, the optimal insertion site for foreign gene expression remained to be determined. In the present study, we inserted the green fluorescence protein (GFP) gene into five different intergenic ...

  11. Cytomegalovirus and immunotherapy: opportunistic pathogen, novel target for cancer and a promising vaccine vector.

    PubMed

    Quinn, Michael; Erkes, Dan A; Snyder, Christopher M

    2016-02-01

    Cytomegalovirus (CMV) is a β-herpesvirus that infects most people in the world and is almost always asymptomatic in the healthy host. However, CMV persists for life, requiring continuous immune surveillance to prevent disease and thus, CMV is a frequent complication in immune compromised patients. Many groups have been exploring the potential for adoptive T-cell therapies to control CMV reactivation as well as the progression of solid tumors harboring CMV. In addition, CMV itself is being explored as a vaccine vector for eliciting potent T-cell responses. This review will discuss key features of the basic biology of CMV-specific T cells as well as highlighting unanswered questions and ongoing work in the development of T-cell-based immunotherapies to target CMV.

  12. Recombinant canarypox vectored West Nile virus (WNV) vaccine protects dogs and cats against a mosquito WNV challenge.

    PubMed

    Karaca, K; Bowen, R; Austgen, L E; Teehee, M; Siger, L; Grosenbaugh, D; Loosemore, L; Audonnet, J-C; Nordgren, R; Minke, J M

    2005-05-31

    The safety and efficacy of a canarypox vector expressing PrM and E genes of West Nile virus (WNV) (ALVAC-WNV) was evaluated in dogs and cats. One group of 17 dogs (vaccinated with 10(5.6) TCID(50)) and two groups of cats (groups 1 [n=14] vaccinated with 10(7.5) TCID(50) and 2 [n=8] 10(5.6) TCID(50)) were vaccinated twice at 28-day intervals. Fifteen dogs and eleven cats served as negative controls. The cats and dogs were challenged 120 and 135 days after the second immunization, respectively via the bites of Aedes albopictus mosquitoes infected with WNV. The first dose of vaccine induced a detectable antibody response in four dogs and five cats (one immunized with low and four with high doses). After the second dose, all the vaccinated dogs and all of the cats, immunized with high dose had detectable antibody titers, whereas only four of eight cats in the low dose group were seropositive. None of the vaccinated dogs and one vaccinated cat developed viremia following the WNV mosquito-challenge. In contrast, 14 of the 15 control dogs and 9 of the 11 control cats developed viremia. The experimental vaccine described in this study may be of value in the prevention of WNV infection in dogs and cats.

  13. Novel Cocaine Vaccine Linked to a Disrupted Adenovirus Gene Transfer Vector Blocks Cocaine Psychostimulant and Reinforcing Effects

    PubMed Central

    Wee, Sunmee; Hicks, Martin J; De, Bishnu P; Rosenberg, Jonathan B; Moreno, Amira Y; Kaminsky, Stephen M; Janda, Kim D; Crystal, Ronald G; Koob, George F

    2012-01-01

    Immunotherapy is a promising treatment for drug addiction. However, insufficient immune responses to vaccines in most subjects pose a challenge. In this study, we tested the efficacy of a new cocaine vaccine (dAd5GNE) in antagonizing cocaine addiction-related behaviors in rats. This vaccine used a disrupted serotype 5 adenovirus (Ad) gene transfer vector coupled to a third-generation cocaine hapten, termed GNE (6-(2R,3S)-3-(benzoyloxy)-8-methyl-8-azabicyclo [3.2.1] octane-2-carboxamido-hexanoic acid). Three groups of rats were immunized with dAd5GNE. One group was injected with 3H-cocaine, and radioactivity in the blood and brain was determined. A second group was tested for cocaine-induced locomotor sensitization. A third group was examined for cocaine self-administration, extinction, and reinstatement of responding for cocaine. Antibody titers were determined at various time-points. In each experiment, we added a control group that was immunized with dAd5 without a hapten. The vaccination with dAd5GNE produced long-lasting high titers (>105) of anti-cocaine antibodies in all of the rats. The vaccination inhibited cocaine-induced hyperlocomotor activity and sensitization. Vaccinated rats acquired cocaine self-administration, but they showed less motivation to self-administer cocaine under a progressive-ratio schedule than control rats. When cocaine was not available in a session, control rats exhibited ‘extinction burst' responding, whereas vaccinated rats did not. Moreover, when primed with cocaine, vaccinated rats did not reinstate responding, suggesting a blockade of cocaine-seeking behavior. These data strongly suggest that our dAd5GNE vector-based vaccine may be effective in treating cocaine abuse and addiction. PMID:21918504

  14. Novel cocaine vaccine linked to a disrupted adenovirus gene transfer vector blocks cocaine psychostimulant and reinforcing effects.

    PubMed

    Wee, Sunmee; Hicks, Martin J; De, Bishnu P; Rosenberg, Jonathan B; Moreno, Amira Y; Kaminsky, Stephen M; Janda, Kim D; Crystal, Ronald G; Koob, George F

    2012-04-01

    Immunotherapy is a promising treatment for drug addiction. However, insufficient immune responses to vaccines in most subjects pose a challenge. In this study, we tested the efficacy of a new cocaine vaccine (dAd5GNE) in antagonizing cocaine addiction-related behaviors in rats. This vaccine used a disrupted serotype 5 adenovirus (Ad) gene transfer vector coupled to a third-generation cocaine hapten, termed GNE (6-(2R,3S)-3-(benzoyloxy)-8-methyl-8-azabicyclo [3.2.1] octane-2-carboxamido-hexanoic acid). Three groups of rats were immunized with dAd5GNE. One group was injected with (3)H-cocaine, and radioactivity in the blood and brain was determined. A second group was tested for cocaine-induced locomotor sensitization. A third group was examined for cocaine self-administration, extinction, and reinstatement of responding for cocaine. Antibody titers were determined at various time-points. In each experiment, we added a control group that was immunized with dAd5 without a hapten. The vaccination with dAd5GNE produced long-lasting high titers (>10(5)) of anti-cocaine antibodies in all of the rats. The vaccination inhibited cocaine-induced hyperlocomotor activity and sensitization. Vaccinated rats acquired cocaine self-administration, but they showed less motivation to self-administer cocaine under a progressive-ratio schedule than control rats. When cocaine was not available in a session, control rats exhibited 'extinction burst' responding, whereas vaccinated rats did not. Moreover, when primed with cocaine, vaccinated rats did not reinstate responding, suggesting a blockade of cocaine-seeking behavior. These data strongly suggest that our dAd5GNE vector-based vaccine may be effective in treating cocaine abuse and addiction.

  15. Combined prophylactic and therapeutic intranasal vaccination against human papillomavirus type-16 using different adeno-associated virus serotype vectors.

    PubMed

    Nieto, Karen; Kern, Andrea; Leuchs, Barbara; Gissmann, Lutz; Müller, Martin; Kleinschmidt, Jürgen A

    2009-01-01

    Cervical cancer is the second most frequent cancer among woman worldwide and is considered to be caused by infection with high-risk papilloma viruses. Genetic immunization using recombinant adeno-associated virus (rAAV) vectors has shown great promise for vaccination against human papillomavirus (HPV) infections. rAAV5, -8 and -9 vectors expressing an HPV16 L1/E7 fusion gene were generated and applied intranasally for combined prophylactic and therapeutic vaccination of mice. The rAAV5 and the rAAV9 vectors showed efficient induction of both humoral and cellular immune responses, whereas rAAV8 failed to immunize mice by the intranasal route. The L1-specific immune response evoked by expression of the L1/E7 fusion gene, however, was lower than that evoked by expression of the L1 antigen alone. This deficiency could be compensated by application of Escherichia coli heat-labile enterotoxin or monophsphoryl lipid as adjuvant upon vaccination with rAAV5-L1/E7. Coimmunization of rAAV9-L1/E7 with rAAV5-L1 or boosting of rAAV9-L1/E7 with rAAV5-L1 strongly increased L1-specific neutralizing antibody titres to levels above those achieved by vaccination with vectors expressing L1 alone. Both vectors elicited a vibrant cytotoxic T-lymphocyte response against L1 or E7. Nasal immunization with rAAV5 or rAAV9 was superior to vaccination with HPV16-L1 virus-like particles (VLPs) or HPV16-L1/E7 CVLPs with respect to humoral and cellular immune responses. Vaccination with the rAAV vectors led to a significant protection of animals against a challenge with different HPV tumour cell lines. Our results show that rAAV5 and rAAV9 vectors are promising candidates for a non-invasive nasal vaccination strategy.

  16. An Adenovirus-Vectored Nasal Vaccine Confers Rapid and Sustained Protection against Anthrax in a Single-Dose Regimen

    PubMed Central

    Jex, Edward; Feng, Tsungwei; Sivko, Gloria S.; Baillie, Leslie W.; Goldman, Stanley; Van Kampen, Kent R.; Tang, De-chu C.

    2013-01-01

    Bacillus anthracis is the causative agent of anthrax, and its spores have been developed into lethal bioweapons. To mitigate an onslaught from airborne anthrax spores that are maliciously disseminated, it is of paramount importance to develop a rapid-response anthrax vaccine that can be mass administered by nonmedical personnel during a crisis. We report here that intranasal instillation of a nonreplicating adenovirus vector encoding B. anthracis protective antigen could confer rapid and sustained protection against inhalation anthrax in mice in a single-dose regimen in the presence of preexisting adenovirus immunity. The potency of the vaccine was greatly enhanced when codons of the antigen gene were optimized to match the tRNA pool found in human cells. In addition, an adenovirus vector encoding lethal factor can confer partial protection against inhalation anthrax and might be coadministered with a protective antigen-based vaccine. PMID:23100479

  17. Vaccinia Virus LC16m8∆ as a Vaccine Vector for Clinical Applications

    PubMed Central

    Kidokoro, Minoru; Shida, Hisatoshi

    2014-01-01

    The LC16m8 strain of vaccinia virus, the active ingredient in the Japanese smallpox vaccine, was derived from the Lister/Elstree strain. LC16m8 is replication-competent and has been administered to over 100,000 infants and 3,000 adults with no serious adverse reactions. Despite this outstanding safety profile, the occurrence of spontaneously-generated large plaque-forming virulent LC16m8 revertants following passage in cell culture is a major drawback. We identified the gene responsible for the reversion and deleted the gene (B5R) from LC16m8 to derive LC16m8Δ. LC16m8∆ is non-pathogenic in immunodeficient severe combined immunodeficiency (SCID) mice, genetically-stable and does not reverse to a large-plaque phenotype upon passage in cell culture, even under conditions in which most LC16m8 populations are replaced by revertants. Moreover, LC16m8∆ is >500-fold more effective than the non-replicating vaccinia virus (VV), Modified Vaccinia Ankara (MVA), at inducing murine immune responses against pathogenic VV. LC16m8∆, which expresses the SIV gag gene, also induced anti-Gag CD8+ T-cells more efficiently than MVA and another non-replicating VV, Dairen I minute-pock variants (DIs). Moreover, LC16m8∆ expressing HIV-1 Env in combination with a Sendai virus vector induced the production of anti-Env antibodies and CD8+ T-cells. Thus, the safety and efficacy of LC16m8∆ mean that it represents an outstanding platform for the development of human vaccine vectors. PMID:26344890

  18. Cross-protective immunity against multiple influenza virus subtypes by a novel modified vaccinia Ankara (MVA) vectored vaccine in mice.

    PubMed

    Brewoo, Joseph N; Powell, Tim D; Jones, Jeremy C; Gundlach, Nancy A; Young, Ginger R; Chu, Haiyan; Das, Subash C; Partidos, Charalambos D; Stinchcomb, Dan T; Osorio, Jorge E

    2013-04-03

    Development of an influenza vaccine that provides cross-protective immunity remains a challenge. Candidate vaccines based on a recombinant modified vaccinia Ankara (MVA) viral vector expressing antigens from influenza (MVA/Flu) viruses were constructed. A vaccine candidate, designated MVA/HA1/C13L/NP, that expresses the hemagglutinin from pandemic H1N1 (A/California/04/09) and the nucleoprotein (NP) from highly pathogenic H5N1 (A/Vietnam/1203/04) fused to a secretory signal sequence from vaccinia virus was highly protective. The vaccine elicited strong antibody titers to homologous H1N1 viruses while cross-reactive antibodies to heterologous viruses were not detectable. In mice, this MVA/HA1/C13L/NP vaccine conferred complete protection against lethal challenge with A/Vietnam/1203/04 (H5N1), A/Norway/3487-2/09 (pandemic H1N1) or A/Influenza/Puerto Rico/8/34 (seasonal H1N1) and partial protection (57.1%) against challenge with seasonal H3N2 virus (A/Aichi/68). The protective efficacy of the vaccine was not affected by pre-existing immunity to vaccinia. Our findings highlight MVA as suitable vector to express multiple influenza antigens that could afford broad cross-protective immunity against multiple subtypes of influenza virus.

  19. Evaluation of lumpy skin disease virus, a capripoxvirus, as a replication-deficient vaccine vector.

    PubMed

    Aspden, Kate; Passmore, Jo-Ann; Tiedt, Friedrich; Williamson, Anna-Lise

    2003-08-01

    Lumpy skin disease virus (LSDV), a capripoxvirus with a host range limited to ruminants, was evaluated as a replication-deficient vaccine vector for use in non-ruminant hosts. By using the rabies virus glycoprotein (RG) as a model antigen, it was demonstrated that recombinant LSDV encoding the rabies glycoprotein (rLSDV-RG) was able to express RG in both permissive (ruminant) and non-permissive (non-ruminant) cells. The recombinant LSDV, however, replicated to maturity only in permissive but not in non-permissive cells. Recombinant LSDV-RG was assessed for its ability to generate immunity against RG in non-ruminant hosts (rabbits and mice). Rabbits inoculated with rLSDV-RG produced rabies virus (RV) neutralizing antibodies at levels twofold higher than those reported by the WHO to be protective. BALB/c mice immunized with rLSDV-RG elicited levels of RV-specific cellular immunity (T-cell proliferation) comparable with those of mice immunized with a commercial inactivated rabies vaccine (Verorab; Pasteur Merieux). Most importantly, mice immunized with rLSDV-RG were protected from an aggressive intracranial rabies virus challenge.

  20. Different Vaccine Vectors Delivering the Same Antigen Elicit CD8plus T Cell Responses with Distinct Clonotype and Epitope Specificity

    SciTech Connect

    M Honda; R Wang; W Kong; M Kanekiyo; Q Akahata; L Xu; K Matsuo; K Natarajan; H Robinson; et al.

    2011-12-31

    Prime-boost immunization with gene-based vectors has been developed to generate more effective vaccines for AIDS, malaria, and tuberculosis. Although these vectors elicit potent T cell responses, the mechanisms by which they stimulate immunity are not well understood. In this study, we show that immunization by a single gene product, HIV-1 envelope, with alternative vector combinations elicits CD8{sup +} cells with different fine specificities and kinetics of mobilization. Vaccine-induced CD8{sup +} T cells recognized overlapping third V region loop peptides. Unexpectedly, two anchor variants bound H-2D{sup d} better than the native sequences, and clones with distinct specificities were elicited by alternative vectors. X-ray crystallography revealed major differences in solvent exposure of MHC-bound peptide epitopes, suggesting that processed HIV-1 envelope gave rise to MHC-I/peptide conformations recognized by distinct CD8{sup +} T cell populations. These findings suggest that different gene-based vectors generate peptides with alternative conformations within MHC-I that elicit distinct T cell responses after vaccination.

  1. Different Vaccine Vectors Delivering the Same Antigen Elicit CD8+ T Cell Responses with Distinct Clonotype and Epitope Specificity

    SciTech Connect

    Honda, M.; Robinson, H.; Wang, R.; Kong, W.-P.; Kanekiyo, M.; Akahata, W.; Xu, L.; Matsuo, K.; Natarajan, K.; Asher, T. E.; Price, D. A.; Douek, D. C.; Margulies, D. H.; Nabel, G. J.

    2009-08-15

    Prime-boost immunization with gene-based vectors has been developed to generate more effective vaccines for AIDS, malaria, and tuberculosis. Although these vectors elicit potent T cell responses, the mechanisms by which they stimulate immunity are not well understood. In this study, we show that immunization by a single gene product, HIV-1 envelope, with alternative vector combinations elicits CD8{sup +} cells with different fine specificities and kinetics of mobilization. Vaccine-induced CD8{sup +} T cells recognized overlapping third V region loop peptides. Unexpectedly, two anchor variants bound H-2D{sup d} better than the native sequences, and clones with distinct specificities were elicited by alternative vectors. X-ray crystallography revealed major differences in solvent exposure of MHC-bound peptide epitopes, suggesting that processed HIV-1 envelope gave rise to MHC-I/peptide conformations recognized by distinct CD8{sup +} T cell populations. These findings suggest that different gene-based vectors generate peptides with alternative conformations within MHC-I that elicit distinct T cell responses after vaccination.

  2. Immune Responses to rAAV6: The Influence of Canine Parvovirus Vaccination and Neonatal Administration of Viral Vector

    PubMed Central

    Arnett, Andrea L. H.; Garikipati, Dilip; Wang, Zejing; Tapscott, Stephen; Chamberlain, Jeffrey S.

    2011-01-01

    Recombinant adeno-associated viral (rAAV) vectors promote long-term gene transfer in many animal species. Significant effort has focused on the evaluation of rAAV delivery and the immune response in both murine and canine models of neuromuscular disease. However, canines provided for research purposes are routinely vaccinated against canine parvovirus (CPV). rAAV and CPV possess significant homology and are both parvoviruses. Thus, any immune response generated to CPV vaccination has the potential to cross-react with rAAV vectors. In this study, we investigated the immune response to rAAV6 delivery in a cohort of CPV-vaccinated canines and evaluated multiple vaccination regimens in a mouse model of CPV-vaccination. We show that CPV-vaccination stimulates production of neutralizing antibodies with minimal cross-reactivity to rAAV6. In addition, no significant differences were observed in the magnitude of the rAAV6-directed immune response between CPV-vaccinated animals and controls. Moreover, CPV-vaccination did not inhibit rAAV6-mediated transduction. We also evaluated the immune response to early rAAV6-vaccination in neonatal mice. The influence of maternal hormones and cytokines leads to a relatively permissive state in the neonate. We hypothesized that immaturity of the immune system would permit induction of tolerance to rAAV6 when delivered during the neonatal period. Mice were vaccinated with rAAV6 at 1 or 5 days of age, and subsequently challenged with rAAV6 exposure during adulthood via two sequential IM injections, 1 month apart. All vaccinated animals generated a significant neutralizing antibody response to rAAV6-vaccination that was enhanced following IM injection in adulthood. Taken together, these data demonstrate that the immune response raised against rAAV6 is distinct from that which is elicited by the standard parvoviral vaccines and is sufficient to prevent stable tolerization in neonatal mice. PMID:22065964

  3. Lactococci and lactobacilli as mucosal delivery vectors for therapeutic proteins and DNA vaccines

    PubMed Central

    2011-01-01

    Food-grade Lactic Acid Bacteria (LAB) have been safely consumed for centuries by humans in fermented foods. Thus, they are good candidates to develop novel oral vectors, constituting attractive alternatives to attenuated pathogens, for mucosal delivery strategies. Herein, this review summarizes our research, up until now, on the use of LAB as mucosal delivery vectors for therapeutic proteins and DNA vaccines. Most of our work has been based on the model LAB Lactococcus lactis, for which we have developed efficient genetic tools, including expression signals and host strains, for the heterologous expression of therapeutic proteins such as antigens, cytokines and enzymes. Resulting recombinant lactococci strains have been tested successfully for their prophylactic and therapeutic effects in different animal models: i) against human papillomavirus type 16 (HPV-16)-induced tumors in mice, ii) to partially prevent a bovine β-lactoglobulin (BLG)-allergic reaction in mice and iii) to regulate body weight and food consumption in obese mice. Strikingly, all of these tools have been successfully transposed to the Lactobacillus genus, in recent years, within our laboratory. Notably, anti-oxidative Lactobacillus casei strains were constructed and tested in two chemically-induced colitis models. In parallel, we also developed a strategy based on the use of L. lactis to deliver DNA at the mucosal level, and were able to show that L. lactis is able to modulate the host response through DNA delivery. Today, we consider that all of our consistent data, together with those obtained by other groups, demonstrate and reinforce the interest of using LAB, particularly lactococci and lactobacilli strains, to develop novel therapeutic protein mucosal delivery vectors which should be tested now in human clinical trials. PMID:21995317

  4. Membrane-bound SIV envelope trimers are immunogenic in ferrets after intranasal vaccination with a replication-competent canine distemper virus vector.

    PubMed

    Zhang, Xinsheng; Wallace, Olivia; Wright, Kevin J; Backer, Martin; Coleman, John W; Koehnke, Rebecca; Frenk, Esther; Domi, Arban; Chiuchiolo, Maria J; DeStefano, Joanne; Narpala, Sandeep; Powell, Rebecca; Morrow, Gavin; Boggiano, Cesar; Zamb, Timothy J; Richter King, C; Parks, Christopher L

    2013-11-01

    We are investigating canine distemper virus (CDV) as a vaccine vector for the delivery of HIV envelope (Env) that closely resembles the native trimeric spike. We selected CDV because it will promote vaccine delivery to lymphoid tissues, and because human exposure is infrequent, reducing potential effects of pre-existing immunity. Using SIV Env as a model, we tested a number of vector and gene insert designs. Vectors containing a gene inserted between the CDV H and L genes, which encoded Env lacking most of its cytoplasmic tail, propagated efficiently in Vero cells, expressed the immunogen on the cell surface, and incorporated the SIV glycoprotein into progeny virus particles. When ferrets were vaccinated intranasally, there were no signs of distress, vector replication was observed in the gut-associated lymphoid tissues, and the animals produced anti-SIV Env antibodies. These data show that live CDV-SIV Env vectors can safely induce anti-Env immune responses following intranasal vaccination.

  5. An influenza viral vector Brucella abortus vaccine induces good cross-protection against Brucella melitensis infection in pregnant heifers.

    PubMed

    Tabynov, Kaissar; Ryskeldinova, Sholpan; Sansyzbay, Abylai

    2015-07-17

    Brucella melitensis can be transmitted and cause disease in cattle herds as a result of inadequate management of mixed livestock farms. Ideally, vaccines against Brucella abortus for cattle should also provide cross-protection against B. melitensis. Previously we created a novel influenza viral vector B. abortus (Flu-BA) vaccine expressing the Brucella ribosomal proteins L7/L12 or Omp16. This study demonstrated Flu-BA vaccine with adjuvant Montanide Gel01 provided 100% protection against abortion in vaccinated pregnant heifers and good cross-protection of the heifers and their calves or fetuses (90-100%) after challenge with B. melitensis 16M; the level of protection provided by Flu-BA was comparable to the commercial vaccine B. abortus S19. In terms of the index of infection and colonization of Brucella in tissues, both vaccines demonstrated significant (P=0.02 to P<0.0001) protection against B. melitensis 16M infection compared to the negative control group (PBS+Montanide Gel01). Thus, we conclude the Flu-BA vaccine provides cross-protection against B. melitensis infection in pregnant heifers.

  6. Viral vector vaccines expressing nucleoprotein and phosphoprotein genes of avian bornaviruses ameliorate homologous challenge infections in cockatiels and common canaries

    PubMed Central

    Olbert, Marita; Römer-Oberdörfer, Angela; Herden, Christiane; Malberg, Sara; Runge, Solveig; Staeheli, Peter; Rubbenstroth, Dennis

    2016-01-01

    Avian bornaviruses are causative agents of proventricular dilatation disease (PDD), an often fatal disease of parrots and related species (order Psittaciformes) which is widely distributed in captive psittacine populations and may affect endangered species. Here, we established a vaccination strategy employing two different well described viral vectors, namely recombinant Newcastle disease virus (NDV) and modified vaccinia virus Ankara (MVA) that were engineered to express the phosphoprotein and nucleoprotein genes of two avian bornaviruses, parrot bornavirus 4 (PaBV-4) and canary bornavirus 2 (CnBV-2). When combined in a heterologous prime/boost vaccination regime, NDV and MVA vaccine viruses established self-limiting infections and induced a bornavirus-specific humoral immune response in cockatiels (Nymphicus hollandicus) and common canaries (Serinus canaria forma domestica). After challenge infection with a homologous bornavirus, shedding of bornavirus RNA and viral loads in tissue samples were significantly reduced in immunized birds, indicating that vaccination markedly delayed the course of infection. However, cockatiels still developed signs of PDD if the vaccine failed to prevent viral persistence. Our work demonstrates that avian bornavirus infections can be repressed by vaccine-induced immunity. It represents a first crucial step towards a protective vaccination strategy to combat PDD in psittacine birds. PMID:27830736

  7. Viral vector vaccines expressing nucleoprotein and phosphoprotein genes of avian bornaviruses ameliorate homologous challenge infections in cockatiels and common canaries.

    PubMed

    Olbert, Marita; Römer-Oberdörfer, Angela; Herden, Christiane; Malberg, Sara; Runge, Solveig; Staeheli, Peter; Rubbenstroth, Dennis

    2016-11-10

    Avian bornaviruses are causative agents of proventricular dilatation disease (PDD), an often fatal disease of parrots and related species (order Psittaciformes) which is widely distributed in captive psittacine populations and may affect endangered species. Here, we established a vaccination strategy employing two different well described viral vectors, namely recombinant Newcastle disease virus (NDV) and modified vaccinia virus Ankara (MVA) that were engineered to express the phosphoprotein and nucleoprotein genes of two avian bornaviruses, parrot bornavirus 4 (PaBV-4) and canary bornavirus 2 (CnBV-2). When combined in a heterologous prime/boost vaccination regime, NDV and MVA vaccine viruses established self-limiting infections and induced a bornavirus-specific humoral immune response in cockatiels (Nymphicus hollandicus) and common canaries (Serinus canaria forma domestica). After challenge infection with a homologous bornavirus, shedding of bornavirus RNA and viral loads in tissue samples were significantly reduced in immunized birds, indicating that vaccination markedly delayed the course of infection. However, cockatiels still developed signs of PDD if the vaccine failed to prevent viral persistence. Our work demonstrates that avian bornavirus infections can be repressed by vaccine-induced immunity. It represents a first crucial step towards a protective vaccination strategy to combat PDD in psittacine birds.

  8. Enhancement of Antituberculosis Immunity in a Humanized Model System by a Novel Virus-Vectored Respiratory Mucosal Vaccine.

    PubMed

    Yao, Yushi; Lai, Rocky; Afkhami, Sam; Haddadi, Siamak; Zganiacz, Anna; Vahedi, Fatemeh; Ashkar, Ali A; Kaushic, Charu; Jeyanathan, Mangalakumari; Xing, Zhou

    2017-07-01

    The translation of preclinically promising novel tuberculosis vaccines to ultimate human applications has been challenged by the lack of animal models with an immune system equivalent to the human immune system in its genetic diversity and level of susceptibility to tuberculosis. We have developed a humanized mice (Hu-mice) tuberculosis model system to investigate the clinical relevance of a novel virus-vectored (VV) tuberculosis vaccine administered via respiratory mucosal or parenteral route. We find that VV vaccine activates T cells in Hu-mice as it does in human vaccinees. The respiratory mucosal route for delivery of VV vaccine in Hu-mice, but not the parenteral route, significantly reduces the humanlike lung tuberculosis outcomes in a human T-cell-dependent manner. Our results suggest that the Hu-mouse can be used to predict the protective efficacy of novel tuberculosis vaccines/strategies before they proceed to large, expensive human trials. This new vaccine testing system will facilitate the global pace of clinical tuberculosis vaccine development.

  9. Serologic responses after vaccination of fennec foxes (Vulpes zerda) and meerkats (Suricata suricatta) with a live, canarypox-vectored canine distemper virus vaccine.

    PubMed

    Coke, Rob L; Backues, Kay A; Hoover, John P; Saliki, Jeremiah T; Ritchey, Jerry W; West, Gary D

    2005-06-01

    Fennec foxes (Vulpes zerda) and meerkats (Suricata suricatta) are considered to be susceptible to canine distemper virus (CDV) infection. Although no definitive clinical cases of natural CDV infections have been reported, mortalities due to CDV have been suspected and are reported in other closely related species. A commercially available monovalent, live, canarypox-vectored CDV vaccine induced neutralizing antibody titers that were maintained for at least a year in both fennec foxes and meerkats.

  10. A tetravalent alphavirus-vector based dengue vaccine provides effective immunity in an early life mouse model.

    PubMed

    Khalil, Syed Muaz; Tonkin, Daniel R; Mattocks, Melissa D; Snead, Andrew T; Johnston, Robert E; White, Laura J

    2014-07-07

    Dengue viruses (DENV1-4) cause 390 million clinical infections every year, several hundred thousand of which progress to severe hemorrhagic and shock syndromes. Preexisting immunity resulting from a previous DENV infection is the major risk factor for severe dengue during secondary heterologous infections. During primary infections in infants, maternal antibodies pose an analogous risk. At the same time, maternal antibodies are likely to prevent induction of endogenous anti-DENV antibodies in response to current live, attenuated virus (LAV) vaccine candidates. Any effective early life dengue vaccine has to overcome maternal antibody interference (leading to ineffective vaccination) and poor induction of antibody responses (increasing the risk of severe dengue disease upon primary infection). In a previous study, we demonstrated that a non-propagating Venezuelan equine encephalitis virus replicon expression vector (VRP), expressing the ectodomain of DENV E protein (E85), overcomes maternal interference in a BALB/c mouse model. We report here that a single immunization with a tetravalent VRP vaccine induced NAb and T-cell responses to each serotype at a level equivalent to the monovalent vaccine components, suggesting that this vaccine modality can overcome serotype interference. Furthermore, neonatal immunization was durable and could be boosted later in life to further increase NAb and T-cell responses. Although the neonatal immune response was lower in magnitude than responses in adult BALB/c mice, we demonstrate that VRP vaccines generated protective immunity from a lethal challenge after a single neonatal immunization. In summary, VRP vaccines expressing DENV antigens were immunogenic and protective in neonates, and hence are promising candidates for safe and effective vaccination in early life.

  11. A tetravalent alphavirus-vector based Dengue vaccine provides effective immunity in an early life mouse model

    PubMed Central

    Khalil, Syed Muaz; Tonkin, Daniel R.; Mattocks, Melissa D.; Snead, Andrew T.; Johnston, Robert E.; White, Laura J.

    2014-01-01

    Dengue viruses (DENV1-4) cause 390 million clinical infections every year, several hundred thousand of which progress to severe hemorrhagic and shock syndromes. Preexisting immunity resulting from a previous DENV infection is the major risk factor for severe dengue during secondary heterologous infections. During primary infections in infants, maternal antibodies pose an analogous risk. At the same time, maternal antibodies are likely to prevent induction of endogenous anti-DENV antibodies in response to current live, attenuated virus (LAV) vaccine candidates. Any effective early life dengue vaccine has to overcome maternal antibody interference (leading to ineffective vaccination) and poor induction of antibody responses (increasing the risk of severe dengue disease upon primary infection). In a previous study, we demonstrated that a non-propagating Venezuelan equine encephalitis virus replicon expression vector (VRP), expressing the ectodomain of DENV E protein (E85), overcomes maternal interference in a BALB/c mouse model. We report here that a single immunization with a tetravalent VRP vaccine induced NAb and T-cell responses to each serotype at a level equivalent to the monovalent vaccine components, suggesting that this vaccine modality can overcome serotype interference. Furthermore, neonatal immunization was durable and could be boosted later in life to further increase NAb and T-cell responses. Although the neonatal immune response was lower in magnitude than responses in adult BALB/c mice, we demonstrate that VRP vaccines generated protective immunity from a lethal challenge after a single neonatal immunization. In summary, VRP vaccines expressing DENV antigens were immunogenic and protective in neonates, and hence are promising candidates for safe and effective vaccination in early life. PMID:24882043

  12. Chimpanzee adenovirus and MVA-vectored respiratory syncytial virus vaccine is safe and expands humoral and cellular immunity in adults

    PubMed Central

    Green, CA; Scarselli, E; Sande, CJ; Thompson, AJ; de Lara, CM; Taylor, K; Haworth, K; Del Sorbo, M; Angus, B; Siani, L; Di Marco, S; Traboni, C; Folgori, A; Colloca, S; Capone, S; Vitelli, A; Cortese, R; Klenerman, P; Nicosia, A; Pollard, AJ

    2015-01-01

    Respiratory syncytial virus (RSV) causes respiratory infection in annual epidemics, with infants and the elderly at particular risk of developing severe disease and death. However, despite its importance, no vaccine exists. The chimpanzee adenovirus, PanAd3-RSV, and modified vaccinia virus Ankara, MVA-RSV, are replication defective viral vectors encoding the RSV proteins F, N and M2-1 for the induction of humoral and cellular responses. We performed an open-label, dose-escalation, phase 1 clinical trial in 42 healthy adults in which four different combinations of prime/boost vaccinations were investigated for safety and immunogenicity, including both intra-muscular and intra-nasal administration of the adenoviral vectored vaccine. The vaccines were safe and well tolerated, with the most common reported adverse events being mild injection site reactions. No vaccine-related serious adverse events occurred. RSV neutralising antibody titres rose in response to intramuscular (IM) prime with PanAd3-RSV, and after IM boost for individuals primed by the intra-nasal (IN) route. Circulating anti-F IgG and IgA antibody secreting cells (ASCs) were observed after IM prime and IM boost. RSV-specific T-cell responses were increased after IM PanAd3-RSV prime and were most efficiently boosted by IM MVA-RSV. IFNγ secretion after boost was from both CD4+ and CD8+ T-cells, without detectable Th2 cytokines that have been previously associated with immune pathogenesis following exposure to RSV after formalin inactivated RSV vaccine. In conclusion, PanAd3-RSV and MVA-RSV are safe and immunogenic in healthy adults. These vaccine candidates warrant further clinical evaluation of efficacy to assess their potential to reduce the burden of RSV disease. PMID:26268313

  13. Protective Efficacy in Sheep of Adenovirus-Vectored Vaccines against Bluetongue Virus Is Associated with Specific T Cell Responses

    PubMed Central

    Martín, Verónica; Pascual, Elena; Avia, Miguel; Peña, Lourdes; Valcárcel, Félix; Sevilla, Noemí

    2015-01-01

    Bluetongue virus (BTV) is an economically important Orbivirus of the Reoviridae family that causes a hemorrhagic disease in ruminants. Its control has been achieved by inactivated-vaccines that have proven to protect against homologous BTV challenge although unable to induce long-term immunity. Therefore, a more efficient control strategy needs to be developed. Recombinant adenovirus vectors are lead vaccine candidates for protection of several diseases, mainly because of their potency to induce potent T cell immunity. Here we report the induction of humoral and T-cell mediated responses able to protect animals against BTV challenge by recombinant replication-defective human adenovirus serotype 5 (Ad5) expressing either VP7, VP2 or NS3 BTV proteins. First we used the IFNAR(-/-) mouse model system to establish a proof of principle, and afterwards we assayed the protective efficacy in sheep, the natural host of BTV. Mice were completely protected against BTV challenge, developing humoral and BTV-specific CD8+- and CD4+-T cell responses by vaccination with the different rAd5. Sheep vaccinated with Ad5-BTV-VP2 and Ad5-BTV-VP7 or only with Ad5-BTV-VP7 and challenged with BTV showed mild disease symptoms and reduced viremia. This partial protection was achieved in the absence of neutralizing antibodies but strong BTV-specific CD8+ T cell responses in those sheep vaccinated with Ad5-BTV-VP7. These data indicate that rAd5 is a suitable vaccine vector to induce T cell immunity during BTV vaccination and provide new data regarding the relevance of T cell responses in protection during BTV infection. PMID:26619062

  14. Enhanced expression of HIV and SIV vaccine antigens in the structural gene region of live attenuated rubella viral vectors and their incorporation into virions.

    PubMed

    Virnik, Konstantin; Ni, Yisheng; Berkower, Ira

    2013-04-19

    Despite the urgent need for an HIV vaccine, its development has been hindered by virus variability, weak immunogenicity of conserved epitopes, and limited durability of the immune response. For other viruses, difficulties with immunogenicity were overcome by developing live attenuated vaccine strains. However, there is no reliable method of attenuation for HIV, and an attenuated strain would risk reversion to wild type. We have developed rubella viral vectors, based on the live attenuated vaccine strain RA27/3, which are capable of expressing important HIV and SIV vaccine antigens. The rubella vaccine strain has demonstrated safety, immunogenicity, and long lasting protection in millions of children. Rubella vectors combine the growth and immunogenicity of live rubella vaccine with the antigenicity of HIV or SIV inserts. This is the first report showing that live attenuated rubella vectors can stably express HIV and SIV vaccine antigens at an insertion site located within the structural gene region. Unlike the Not I site described previously, the new site accommodates a broader range of vaccine antigens without interfering with essential viral functions. In addition, antigens expressed at the structural site were controlled by the strong subgenomic promoter, resulting in higher levels and longer duration of antigen expression. The inserts were expressed as part of the structural polyprotein, processed to free antigen, and incorporated into rubella virions. The rubella vaccine strain readily infects rhesus macaques, and these animals will be the model of choice for testing vector growth in vivo and immunogenicity.

  15. Construction and immunogenicity in a prime-boost regimen of a Semliki Forest virus-vectored experimental HIV clade A vaccine.

    PubMed

    Hanke, Tomás; Barnfield, Christina; Wee, Edmund G-T; Agren, Lena; Samuel, Rachel V; Larke, Natasha; Liljeström, Peter

    2003-02-01

    A novel, experimental subunit human immunodeficiency virus (HIV) vaccine, SFV.HIVA, was constructed. This consists of Semliki Forest virus (SFV), which is a suitable vaccine vector for use in humans, and a passenger gene encoding HIVA, which is an immunogen derived from HIV-1 clade A that is being currently tested in clinical trials of combined DNA- and modified vaccinia virus Ankara (MVA)-vectored vaccines in Oxford (UK) and Nairobi (Kenya). In the mouse, the SFV.HIVA vaccine was highly immunogenic for T cell-mediated immune responses and induced T cell memory that lasted for at least 6 months. SFV.HIVA was also compared to the vaccines currently used in the clinical trials and was shown to be as effective in T cell induction as pTHr.HIVA DNA but less immunogenic than MVA.HIVA. When tested in a prime-boost regimen, SFV.HIVA-induced responses could be boosted by MVA.HIVA. This work is a part of a long-term effort to build a panel of subunit vaccines expressing a common immunogen, which will allow both a direct comparison of various vaccine vectors and combined vaccination regimens in humans and provide more flexibility and/or a potential optimization of vaccinations for individuals based on their pre-existing anti-vector immunity.

  16. Avirulent Marek’s Disease Virus Type 1 Strain 814 Vectored Vaccine Expressing Avian Influenza (AI) Virus H5 Haemagglutinin Induced Better Protection Than Turkey Herpesvirus Vectored AI Vaccine

    PubMed Central

    Cui, Xianlan; Zhao, Yan; Shi, Xingming; Li, Qiaoling; Yan, Shuai; Gao, Ming; Wang, Mei; Liu, Changjun; Wang, Yunfeng

    2013-01-01

    Background Herpesvirus of turkey (HVT) as a vector to express the haemagglutinin (HA) of avian influenza virus (AIV) H5 was developed and its protection against lethal Marek’s disease virus (MDV) and highly pathogenic AIV (HPAIV) challenges was evaluated previously. It is well-known that avirulemt MDV type 1 vaccines are more effective than HVT in prevention of lethal MDV infection. To further increase protective efficacy against HPAIV and lethal MDV, a recombinant MDV type 1 strain 814 was developed to express HA gene of HPAIV H5N1. Methodology/Principal Findings A recombinant MDV-1 strain 814 expressing HA gene of HPAIV H5N1 virus A/goose/Guangdong/3/96 at the US2 site (rMDV-HA) was developed under the control of a human CMV immediate-early promoter. The HA expression in the rMDV-HA was tested by immunofluorescence and Western blot analyses, and in vitro and in vivo growth properties of rMDV-HA were also analyzed. Furthermore, we evaluated and compared the protective immunity of rMDV-HA and previously constructed rHVT-HA against HPAIV and lethal MDV. Vaccination of chickens with rMDV-HA induced 80% protection against HPAIV, which was better than the protection rate by rHVT-HA (66.7%). In the animal study with MDV challenge, chickens immunized with rMDV-HA were completely protected against virulent MDV strain J-1 whereas rHVT-HA only induced 80% protection with the same challenge dose. Conclusions/Significance The rMDV-HA vaccine was more effective than rHVT-HA vaccine for protection against lethal MDV and HPAIV challenges. Therefore, avirulent MDV type 1 vaccine is a better vector than HVT for development of a recombinant live virus vaccine against virulent MDV and HPAIV in poultry. PMID:23301062

  17. Architectural Insight into Inovirus-Associated Vectors (IAVs) and Development of IAV-Based Vaccines Inducing Humoral and Cellular Responses: Implications in HIV-1 Vaccines

    PubMed Central

    Hassapis, Kyriakos A.; Stylianou, Dora C.; Kostrikis, Leondios G.

    2014-01-01

    Inovirus-associated vectors (IAVs) are engineered, non-lytic, filamentous bacteriophages that are assembled primarily from thousands of copies of the major coat protein gp8 and just five copies of each of the four minor coat proteins gp3, gp6, gp7 and gp9. Inovirus display studies have shown that the architecture of inoviruses makes all coat proteins of the inoviral particle accessible to the outside. This particular feature of IAVs allows foreign antigenic peptides to be displayed on the outer surface of the virion fused to its coat proteins and for more than two decades has been exploited in many applications including antibody or peptide display libraries, drug design, and vaccine development against infectious and non-infectious diseases. As vaccine carriers, IAVs have been shown to elicit both a cellular and humoral response against various pathogens through the display of antibody epitopes on their coat proteins. Despite their high immunogenicity, the goal of developing an effective vaccine against HIV-1 has not yet materialized. One possible limitation of previous efforts was the use of broadly neutralizing antibodies, which exhibited autoreactivity properties. In the past five years, however, new, more potent broadly neutralizing antibodies that do not exhibit autoreactivity properties have been isolated from HIV-1 infected individuals, suggesting that vaccination strategies aimed at producing such broadly neutralizing antibodies may confer protection against infection. The utilization of these new, broadly neutralizing antibodies in combination with the architectural traits of IAVs have driven the current developments in the design of an inovirus-based vaccine against HIV-1. This article reviews the applications of IAVs in vaccine development, with particular emphasis on the design of inoviral-based vaccines against HIV-1. PMID:25525909

  18. Architectural insight into inovirus-associated vectors (IAVs) and development of IAV-based vaccines inducing humoral and cellular responses: implications in HIV-1 vaccines.

    PubMed

    Hassapis, Kyriakos A; Stylianou, Dora C; Kostrikis, Leondios G

    2014-12-17

    Inovirus-associated vectors (IAVs) are engineered, non-lytic, filamentous bacteriophages that are assembled primarily from thousands of copies of the major coat protein gp8 and just five copies of each of the four minor coat proteins gp3, gp6, gp7 and gp9. Inovirus display studies have shown that the architecture of inoviruses makes all coat proteins of the inoviral particle accessible to the outside. This particular feature of IAVs allows foreign antigenic peptides to be displayed on the outer surface of the virion fused to its coat proteins and for more than two decades has been exploited in many applications including antibody or peptide display libraries, drug design, and vaccine development against infectious and non-infectious diseases. As vaccine carriers, IAVs have been shown to elicit both a cellular and humoral response against various pathogens through the display of antibody epitopes on their coat proteins. Despite their high immunogenicity, the goal of developing an effective vaccine against HIV-1 has not yet materialized. One possible limitation of previous efforts was the use of broadly neutralizing antibodies, which exhibited autoreactivity properties. In the past five years, however, new, more potent broadly neutralizing antibodies that do not exhibit autoreactivity properties have been isolated from HIV-1 infected individuals, suggesting that vaccination strategies aimed at producing such broadly neutralizing antibodies may confer protection against infection. The utilization of these new, broadly neutralizing antibodies in combination with the architectural traits of IAVs have driven the current developments in the design of an inovirus-based vaccine against HIV-1. This article reviews the applications of IAVs in vaccine development, with particular emphasis on the design of inoviral-based vaccines against HIV-1.

  19. Germinal Center B Cell and T Follicular Helper Cell Responses to Viral Vector and Protein-in-Adjuvant Vaccines

    PubMed Central

    Wang, Chuan; Hart, Matthew; Chui, Cecilia; Ajuogu, Augustine; Brian, Iona J.; de Cassan, Simone C.; Borrow, Persephone; Draper, Simon J.

    2016-01-01

    There is great interest in the development of Ab-inducing subunit vaccines targeting infections, including HIV, malaria, and Ebola. We previously reported that adenovirus vectored vaccines are potent in priming Ab responses, but uncertainty remains regarding the optimal approach for induction of humoral immune responses. In this study, using OVA as a model Ag, we assessed the magnitude of the primary and anamnestic Ag–specific IgG responses of mice to four clinically relevant vaccine formulations: replication-deficient adenovirus; modified vaccinia Ankara (a poxvirus); protein with alum; and protein in the squalene oil-in-water adjuvant Addavax. We then used flow cytometric assays capable of measuring total and Ag-specific germinal center (GC) B cell and follicular Th cell responses to compare the induction of these responses by the different formulations. We report that adenovirus vectored vaccines induce Ag insert–specific GC B cell and Ab responses of a magnitude comparable to those induced by a potent protein/squalene oil-in-water formulation whereas—despite a robust overall GC response—the insert-specific GC B cell and Ab responses induced by modified vaccinia Ankara were extremely weak. Ag-specific follicular Th cell responses to adenovirus vectored vaccines exceeded those induced by other platforms at day 7 after immunization. We found little evidence that innate immune activation by adenovirus may act as an adjuvant in such a manner that the humoral response to a recombinant protein may be enhanced by coadministering with an adenovirus lacking a transgene of interest. Overall, these studies provide further support for the use of replication-deficient adenoviruses to induce humoral responses. PMID:27412417

  20. Impact of combined vector-control and vaccination strategies on transmission dynamics of dengue fever: a model-based analysis.

    PubMed

    Knerer, Gerhart; Currie, Christine S M; Brailsford, Sally C

    2015-06-01

    Dengue fever is a vector-borne disease prevalent in tropical and subtropical regions. It is an important public health problem with a considerable and often under-valued disease burden in terms of frequency, cost and quality-of-life. Recent literature reviews have documented the development of mathematical models of dengue fever both to identify important characteristics for future model development as well as to assess the impact of dengue control interventions. Such reviews highlight the importance of short-term cross-protection; antibody-dependent enhancement; and seasonality (in terms of both favourable and unfavourable conditions for mosquitoes). The compartmental model extends work by Bartley (2002) and combines the following factors: seasonality, age-structure, consecutive infection by all four serotypes, cross-protection and immune enhancement, as well as combined vector-host transmission. The model is used to represent dengue transmission dynamics using parameters appropriate for Thailand and to assess the potential impact of combined vector-control and vaccination strategies including routine and catch-up vaccination strategies on disease dynamics. When seasonality and temporary cross-protection between serotypes are included, the model is able to approximate the observed incidence of dengue fever in Thailand. We find vaccination to be the most effective single intervention, albeit with imperfect efficacy (30.2 %) and limited duration of protection. However, in combination, control interventions and vaccination exhibit a marked impact on dengue fever transmission. This study shows that an imperfect vaccine can be a useful weapon in reducing disease spread within the community, although it will be most effective when promoted as one of several strategies for combating dengue fever transmission.

  1. Functionally inactivated dominant viral antigens of human cytomegalovirus delivered in replication incompetent adenovirus type 6 vectors as vaccine candidates.

    PubMed

    Tang, Aimin; Freed, Daniel C; Li, Fengsheng; Meschino, Steve; Prokop, Michael; Bett, Andrew; Casimiro, Danilo; Wang, Dai; Fu, Tong-Ming

    2017-05-11

    T cell immunity is critical in controlling human cytomegalovirus (HCMV) infection in transplant recipients, and T cells targeting viral immediate early proteins such as IE1, IE2 and pp65 have been speculated to be more effective against reactivation. Here we report efforts to construct replication incompetent adenovirus 6 vectors expressing these viral antigens as vaccine candidates. To reduce the potential liabilities of these viral proteins as vaccine antigens, we introduced mutations to inactivate their reported functions including their nuclear localization signals. The modifications greatly reduced their localization to the nuclei, thus limiting their interactions with cellular proteins important for cell cycle modulation and transactivation. The immunogenicity of modified pp65, IE1 and IE2 vaccines was comparable to their wild-type counterparts in mice and the immunogenicity of the modified antigens was demonstrated in non-human primates.

  2. Prime-boost bacillus Calmette-Guérin vaccination with lentivirus-vectored and DNA-based vaccines expressing antigens Ag85B and Rv3425 improves protective efficacy against Mycobacterium tuberculosis in mice.

    PubMed

    Xu, Ying; Yang, Enzhuo; Wang, Jianguang; Li, Rui; Li, Guanghua; Liu, Guoyuan; Song, Na; Huang, Qi; Kong, Cong; Wang, Honghai

    2014-10-01

    To prevent the global spread of tuberculosis (TB), more effective vaccines and vaccination strategies are urgently needed. As a result of the success of bacillus Calmette-Guérin (BCG) in protecting children against miliary and meningeal TB, the majority of individuals will have been vaccinated with BCG; hence, boosting BCG-primed immunity will probably be a key component of future vaccine strategies. In this study, we compared the ability of DNA-, protein- and lentiviral vector-based vaccines that express the antigens Ag85B and Rv3425 to boost the effects of BCG in the context of immunity and protection against Mycobacterium tuberculosis in C57BL/6 mice. Our results demonstrated that prime-boost BCG vaccination with a lentiviral vector expressing the antigens Ag85B and Rv3425 significantly enhanced immune responses, including T helper type 1 and CD8(+) cytotoxic T lymphocyte responses, compared with DNA- and protein-based vaccines. However, lentivirus-vectored and DNA-based vaccines greatly improved the protective efficacy of BCG against M. tuberculosis, as indicated by a lack of weight loss and significantly reduced bacterial loads and histological damage in the lung. Our study suggests that the use of lentiviral or DNA vaccines containing the antigens Ag85B and Rv3425 to boost BCG is a good choice for the rational design of an efficient vaccination strategy against TB.

  3. A Novel Live Pichinde Virus-Based Vaccine Vector Induces Enhanced Humoral and Cellular Immunity after a Booster Dose.

    PubMed

    Dhanwani, Rekha; Zhou, Yanqin; Huang, Qinfeng; Verma, Vikram; Dileepan, Mythili; Ly, Hinh; Liang, Yuying

    2015-12-16

    Pichinde virus (PICV) is a bisegmented enveloped RNA virus that targets macrophages and dendritic cells (DCs) early in infection and induces strong innate and adaptive immunity in mice. We have developed a reverse genetics system to produce live recombinant PICV (strain P18) with a trisegmented RNA genome (rP18tri), which encodes all four PICV gene products and as many as two foreign genes. We have engineered the vector to express the green fluorescent protein (GFP) reporter gene (abbreviated as G in virus designations) and either the hemagglutination (HA [H]) or the nucleoprotein (NP [P]) gene of the influenza A/PR8 virus. The trisegmented viruses rP18tri-G/H and rP18tri-G/P showed slightly reduced growth in vitro and expressed HA and NP, respectively. Mice immunized with rP18tri-G/H were completely protected against lethal influenza virus challenge even 120 days after immunization. These rP18tri-based vectors could efficiently induce both neutralizing antibodies and antigen-specific T cell responses via different immunization routes. Interestingly, the immune responses were significantly increased upon a booster dose and remained at high levels even after three booster doses. In summary, we have developed a novel PICV-based live vaccine vector that can express foreign antigens to induce strong humoral and cell-mediated immunity and is ideal for a prime-and-boost vaccination strategy. We have developed a novel Pichinde virus (PICV)-based live viral vector, rP18tri, that packages three RNA segments and encodes as many as two foreign genes. Using the influenza virus HA and NP genes as model antigens, we show that this rP18tri vector can induce strong humoral and cellular immunity via different immunization routes and can lead to protection in mice. Interestingly, a booster dose further enhances the immune responses, a feature that distinguishes this from other known live viral vectors. In summary, our study demonstrates a unique feature of this live rP18tri vector

  4. A Novel Live Pichinde Virus-Based Vaccine Vector Induces Enhanced Humoral and Cellular Immunity after a Booster Dose

    PubMed Central

    Dhanwani, Rekha; Zhou, Yanqin; Huang, Qinfeng; Verma, Vikram; Dileepan, Mythili; Ly, Hinh

    2015-01-01

    ABSTRACT Pichinde virus (PICV) is a bisegmented enveloped RNA virus that targets macrophages and dendritic cells (DCs) early in infection and induces strong innate and adaptive immunity in mice. We have developed a reverse genetics system to produce live recombinant PICV (strain P18) with a trisegmented RNA genome (rP18tri), which encodes all four PICV gene products and as many as two foreign genes. We have engineered the vector to express the green fluorescent protein (GFP) reporter gene (abbreviated as G in virus designations) and either the hemagglutination (HA [H]) or the nucleoprotein (NP [P]) gene of the influenza A/PR8 virus. The trisegmented viruses rP18tri-G/H and rP18tri-G/P showed slightly reduced growth in vitro and expressed HA and NP, respectively. Mice immunized with rP18tri-G/H were completely protected against lethal influenza virus challenge even 120 days after immunization. These rP18tri-based vectors could efficiently induce both neutralizing antibodies and antigen-specific T cell responses via different immunization routes. Interestingly, the immune responses were significantly increased upon a booster dose and remained at high levels even after three booster doses. In summary, we have developed a novel PICV-based live vaccine vector that can express foreign antigens to induce strong humoral and cell-mediated immunity and is ideal for a prime-and-boost vaccination strategy. IMPORTANCE We have developed a novel Pichinde virus (PICV)-based live viral vector, rP18tri, that packages three RNA segments and encodes as many as two foreign genes. Using the influenza virus HA and NP genes as model antigens, we show that this rP18tri vector can induce strong humoral and cellular immunity via different immunization routes and can lead to protection in mice. Interestingly, a booster dose further enhances the immune responses, a feature that distinguishes this from other known live viral vectors. In summary, our study demonstrates a unique feature of this

  5. Multiple efficacy studies of an adenovirus-vectored foot-and-mouth disease virus serotype A24 subunit vaccine in cattle using direct homologous challenge

    USDA-ARS?s Scientific Manuscript database

    The safety and efficacy of an experimental, replication-deficient, human adenovirus-vectored foot-and-mouth disease virus (FMDV) serotype A24 Cruzeiro capsid-based subunit vaccine (AdtA24) was examined in eight independent cattle studies. AdtA24 non-adjuvanted vaccine was administered intramuscularl...

  6. Immunogenicity and efficacy of fowlpox-vectored and inactivated avian influenza vaccines alone or in a prime-boost schedule in chickens with maternal antibodies

    USDA-ARS?s Scientific Manuscript database

    Inactivated and fowlpox (FP)-vectored vaccines have been used to control avian influenza (AI) in poultry. In endemic countries, breeder flocks are vaccinated and therefore, maternally-derived antibodies (MDA) are transferred to their progeny. Results of several immunogenicity and efficacy studies ...

  7. Development and evaluation of a potential universal Salmonella-vectored avian influenza vaccine

    USDA-ARS?s Scientific Manuscript database

    Development of vaccines for effective control of avian influenza (AI) virus in poultry and wild birds is in high demand. Most AI vaccines target the immunodominant antigens such as hemagglutinin (HA) and neuraminidase (NA); however, these vaccines only provide protection against a particular AI ser...

  8. Recombinant viral-vectored vaccines for the control of avian influenza in poultry

    USDA-ARS?s Scientific Manuscript database

    Vaccination is a commonly used tool for the control of both low pathogenic and highly pathogenic avian influenza viruses. Traditionally inactivated adjuvanted vaccines made from a low pathogenic field strain has been used for vaccination, but advances in molecular biology has allowed a number of di...

  9. Prime-booster vaccination of cattle with an influenza viral vector Brucella abortus vaccine induces a long-term protective immune response against Brucella abortus infection.

    PubMed

    Tabynov, Kaissar; Yespembetov, Bolat; Ryskeldinova, Sholpan; Zinina, Nadezhda; Kydyrbayev, Zhailaubay; Kozhamkulov, Yerken; Inkarbekov, Dulat; Sansyzbay, Abylai

    2016-01-20

    This study analyzed the duration of the antigen-specific humoral and T-cell immune responses and protectiveness of a recently-developed influenza viral vector Brucella abortus (Flu-BA) vaccine expressing Brucella proteins Omp16 and L7/L12 and containing the adjuvant Montadine Gel01 in cattle. At 1 month post-booster vaccination (BV), both humoral (up to 3 months post-BV; GMT IgG ELISA titer 214±55 to 857±136, with a prevalence of IgG2a over IgG1 isotype antibodies) and T-cell immune responses were observed in vaccinated heifers (n=35) compared to control animals (n=35, injected with adjuvant/PBS only). A pronounced T-cell immune response was induced and maintained for 12 months post-BV, as indicated by the lymphocyte stimulation index (2.7±0.4 to 10.1±0.9 cpm) and production of IFN-γ (13.7±1.7 to 40.0±3.0 ng/ml) at 3, 6, 9, and 12 months post-BV. Prime-boost vaccination provided significant protection against B. abortus infection at 3, 6, 9 and 12 months (study duration) post-BV (7 heifers per time point; alpha=0.03-0.01 vs. control group). Between 57.1 and 71.4% of vaccinated animals showed no signs of B. abortus infection (or Brucella isolation) at 3, 6, 9 and 12 months post-BV; the severity of infection, as indicated by the index of infection (P=0.0003 to <0.0001) and rates of Brucella colonization (P=0.03 to <0.0001), was significantly lower for vaccinated diseased animals than appropriate control animals. Good protection from B. abortus infection was also observed among pregnant vaccinated heifers (alpha=0.03), as well as their fetuses and calves (alpha=0.01), for 12 months post-BV. Additionally, 71.4% of vaccinated heifers calved successfully whereas all pregnant control animals aborted (alpha=0.01). Prime-boost vaccination of cattle with Flu-BA induces an antigen-specific humoral and pronounced T cell immune response and most importantly provides good protectiveness, even in pregnant heifers, for at least 12 months post-BV.

  10. Adenoviral Vector Vaccination Induces a Conserved Program of CD8+ T Cell Memory Differentiation in Mouse and Man

    PubMed Central

    Bolinger, Beatrice; Sims, Stuart; Swadling, Leo; O’Hara, Geraldine; de Lara, Catherine; Baban, Dilair; Saghal, Natasha; Lee, Lian Ni; Marchi, Emanuele; Davis, Mark; Newell, Evan; Capone, Stefania; Folgori, Antonella; Barnes, Ellie; Klenerman, Paul

    2015-01-01

    Summary Following exposure to vaccines, antigen-specific CD8+ T cell responses develop as long-term memory pools. Vaccine strategies based on adenoviral vectors, e.g., those developed for HCV, are able to induce and sustain substantial CD8+ T cell populations. How such populations evolve following vaccination remains to be defined at a transcriptional level. We addressed the transcriptional regulation of divergent CD8+ T cell memory pools induced by an adenovector encoding a model antigen (beta-galactosidase). We observe transcriptional profiles that mimic those following infection with persistent pathogens, murine and human cytomegalovirus (CMV). Key transcriptional hallmarks include upregulation of homing receptors and anti-apoptotic pathways, driven by conserved networks of transcription factors, including T-bet. In humans, an adenovirus vaccine induced similar CMV-like phenotypes and transcription factor regulation. These data clarify the core features of CD8+ T cell memory following vaccination with adenovectors and indicate a conserved pathway for memory development shared with persistent herpesviruses. PMID:26586434

  11. Safety and immunogenicity of an FP9-vectored candidate tuberculosis vaccine (FP85A), alone and with candidate vaccine MVA85A in BCG-vaccinated healthy adults

    PubMed Central

    Rowland, Rosalind; Pathan, Ansar A.; Satti, Iman; Poulton, Ian D.; Matsumiya, Magali M. L.; Whittaker, Megan; Minassian, Angela M.; O’Hara, Geraldine A.; Hamill, Matthew; Scott, Janet T.; Harris, Stephanie A.; Poyntz, Hazel C.; Bateman, Cynthia; Meyer, Joel; Williams, Nicola; Gilbert, Sarah C.; Lawrie, Alison M.; Hill, Adrian V.S.; McShane, Helen

    2013-01-01

    The safety and immunogenicity of a new candidate tuberculosis (TB) vaccine, FP85A was evaluated alone and in heterologous prime-boost regimes with another candidate TB vaccine, MVA85A. This was an open label, non-controlled, non-randomized Phase I clinical trial. Healthy previously BCG-vaccinated adult subjects were enrolled sequentially into three groups and vaccinated with FP85A alone, or both FP85A and MVA85A, with a four week interval between vaccinations. Passive and active data on adverse events were collected. Immunogenicity was evaluated by Enzyme Linked Immunospot (ELISpot), flow cytometry and Enzyme Linked Immunosorbent assay (ELISA). Most adverse events were mild and there were no vaccine-related serious adverse events. FP85A vaccination did not enhance antigen 85A-specific cellular immunity. When MVA85A vaccination was preceded by FP85A vaccination, cellular immune responses were lower compared with when MVA85A vaccination was the first immunisation. MVA85A vaccination, but not FP85A vaccination, induced anti-MVA IgG antibodies. Both MVA85A and FP85A vaccinations induced anti-FP9 IgG antibodies. In conclusion, FP85A vaccination was well tolerated but did not induce antigen-specific cellular immune responses. We hypothesize that FP85A induced anti-FP9 IgG antibodies with cross-reactivity for MVA85A, which may have mediated inhibition of the immune response to subsequent MVA85A. ClinicalTrials.gov identification number: NCT00653770 PMID:23143773

  12. An adenovirus vectored mucosal adjuvant augments protection of mice immunized intranasally with an adenovirus-vectored foot-and-mouth disease virus subunit vaccine.

    PubMed

    Alejo, Diana M; Moraes, Mauro P; Liao, Xiaofen; Dias, Camila C; Tulman, Edan R; Diaz-San Segundo, Fayna; Rood, Debra; Grubman, Marvin J; Silbart, Lawrence K

    2013-04-26

    Foot-and-mouth disease virus (FMDV) is a highly contagious pathogen that causes severe morbidity and economic losses to the livestock industry in many countries. The oral and respiratory mucosae are the main ports of entry of FMDV, so the stimulation of local immunity in these tissues may help prevent initial infection and viral spread. E. coli heat-labile enterotoxin (LT) has been described as one of the few molecules that have adjuvant activity at mucosal surfaces. The objective of this study was to evaluate the efficacy of replication-defective adenovirus 5 (Ad5) vectors encoding either of two LT-based mucosal adjuvants, LTB or LTR72. These vectored adjuvants were delivered intranasally to mice concurrent with an Ad5-FMDV vaccine (Ad5-A24) to assess their ability to augment mucosal and systemic humoral immune responses to Ad5-A24 and protection against FMDV. Mice receiving Ad5-A24 plus Ad5-LTR72 had higher levels of mucosal and systemic neutralizing antibodies than those receiving Ad5-A24 alone or Ad5-A24 plus Ad5-LTB. The vaccine plus Ad5-LTR72 group also demonstrated 100% survival after intradermal challenge with a lethal dose of homologous FMDV serotype A24. These results suggest that Ad5-LTR72 could be used as an important tool to enhance mucosal and systemic immunity against FMDV and potentially other pathogens with a common route of entry. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Applying Genomic and Bioinformatic Resources to Human Adenovirus Genomes for Use in Vaccine Development and for Applications in Vector Development for Gene Delivery

    PubMed Central

    Seto, Jason; Walsh, Michael P.; Mahadevan, Padmanabhan; Zhang, Qiwei; Seto, Donald

    2010-01-01

    Technological advances and increasingly cost-effect methodologies in DNA sequencing and computational analysis are providing genome and proteome data for human adenovirus research. Applying these tools, data and derived knowledge to the development of vaccines against these pathogens will provide effective prophylactics. The same data and approaches can be applied to vector development for gene delivery in gene therapy and vaccine delivery protocols. Examination of several field strain genomes and their analyses provide examples of data that are available using these approaches. An example of the development of HAdV-B3 both as a vaccine and also as a vector is presented. PMID:21994597

  14. Vector optimization and needle-free intradermal application of a broadly protective polyvalent influenza A DNA vaccine for pigs and humans.

    PubMed

    Borggren, Marie; Nielsen, Jens; Bragstad, Karoline; Karlsson, Ingrid; Krog, Jesper S; Williams, James A; Fomsgaard, Anders

    2015-01-01

    The threat posed by the 2009 pandemic H1N1 virus emphasized the need for new influenza A virus vaccines inducing a broad cross-protective immune response for use in both humans and pigs. An effective and broad influenza vaccine for pigs would greatly benefit the pork industry and contribute to public health by diminishing the risk of emerging highly pathogenic reassortants. Current inactivated protein vaccines against swine influenza produce only short-lived immunity and have no efficacy against heterologous strains. DNA vaccines are a potential alternative with advantages such as the induction of cellular and humoral immunity, inherent safety and rapid production time. We have previously developed a DNA vaccine encoding selected influenza proteins of pandemic origin and demonstrated broad protective immune responses in ferrets and pigs. In this study, we evaluated our DNA vaccine expressed by next-generation vectors. These new vectors can improve gene expression, but they are also efficiently produced on large scales and comply with regulatory guidelines by avoiding antibiotic resistance genes. In addition, a new needle-free delivery of the vaccine, convenient for mass vaccinations, was compared with intradermal needle injection followed by electroporation. We report that when our DNA vaccine is expressed by the new vectors and delivered to the skin with the needle-free device in the rabbit model, it can elicit an antibody response with the same titers as a conventional vector with intradermal electroporation. The needle-free delivery is already in use for traditional protein vaccines in pigs but should be considered as a practical alternative for the mass administration of broadly protective influenza DNA vaccines.

  15. Biology of Francisella tularensis Subspecies holarctica Live Vaccine Strain in the Tick Vector Dermacentor variabilis

    PubMed Central

    Mani, Rinosh J.; Reichard, Mason V.; Morton, Rebecca J.; Kocan, Katherine M.; Clinkenbeard, Kenneth D.

    2012-01-01

    Background The γ-proteobacterium Francisella tularensis is the etiologic agent of seasonal tick-transmitted tularemia epizootics in rodents and rabbits and of incidental infections in humans. The biology of F. tularensis in its tick vectors has not been fully described, particularly with respect to its quanta and duration of colonization, tissue dissemination, and transovarial transmission. A systematic study of the colonization of Dermacentor variabilis by the F. tularensis subsp. holarctica live vaccine strain (LVS) was undertaken to better understand whether D. variabilis may serve as an inter-epizootic reservoir for F. tularensis. Methodology/Principal Findings Colony-reared larva, nymph, and adult D. variabilis were artificially fed LVS via glass capillary tubes fitted over the tick mouthparts, and the level of colonization determined by microbial culture. Larvae and nymphs were initially colonized with 8.8±0.8×101 and 1.1±0.03×103 CFU/tick, respectively. Post-molting, a significant increase in colonization of both molted nymphs and adults occurred, and LVS persisted in 42% of molted adult ticks at 126 days post-capillary tube feeding. In adult ticks, LVS initially colonized the gut, disseminated to hemolymph and salivary glands by 21 days, and persisted up to 165 days. LVS was detected in the salivary secretions of adult ticks after four days post intra-hemocoelic inoculation, and LVS recovered from salivary gland was infectious to mice with an infectious dose 50% of 3 CFU. LVS in gravid female ticks colonized via the intra-hemocoelic route disseminated to the ovaries and then to the oocytes, but the pathogen was not recovered from the subsequently-hatched larvae. Conclusions/Significance This study demonstrates that D. variabilis can be efficiently colonized with F. tularensis using artificial methods. The persistence of F. tularensis in D. variabilis suggests that this tick species may be involved in the maintenance of enzootic foci of tularemia in the

  16. Improved vaccine protection against retrovirus infection after co-administration of adenoviral vectors encoding viral antigens and type I interferon subtypes

    PubMed Central

    2011-01-01

    Background Type I interferons (IFNs) exhibit direct antiviral effects, but also distinct immunomodulatory properties. In this study, we analyzed type I IFN subtypes for their effect on prophylactic adenovirus-based anti-retroviral vaccination of mice against Friend retrovirus (FV) or HIV. Results Mice were vaccinated with adenoviral vectors encoding FV Env and Gag proteins alone or in combination with vectors encoding IFNα1, IFNα2, IFNα4, IFNα5, IFNα6, IFNα9 or IFNβ. Only the co-administration of adenoviral vectors encoding IFNα2, IFNα4, IFNα6 and IFNα9 resulted in strongly improved immune protection of vaccinated mice from subsequent FV challenge infection with high control over FV-induced splenomegaly and reduced viral loads. The level of protection correlated with augmented virus-specific CD4+ T cell responses and enhanced antibody titers. Similar results were obtained when mice were vaccinated against HIV with adenoviral vectors encoding HIV Env and Gag-Pol in combination with various type I IFN encoding vectors. Here mainly CD4+ T cell responses were enhanced by IFNα subtypes. Conclusions Our results indicate that certain IFNα subtypes have the potential to improve the protective effect of adenovirus-based vaccines against retroviruses. This correlated with augmented virus-specific CD4+ T cell and antibody responses. Thus, co-expression of select type I IFNs may be a valuable tool for the development of anti-retroviral vaccines. PMID:21943056

  17. Microneedle-mediated immunization of an adenovirus-based malaria vaccine enhances antigen-specific antibody immunity and reduces anti-vector responses compared to the intradermal route

    PubMed Central

    Carey, John B.; Vrdoljak, Anto; O'Mahony, Conor; Hill, Adrian V. S.; Draper, Simon J.; Moore, Anne C.

    2014-01-01

    Substantial effort has been placed in developing efficacious recombinant attenuated adenovirus-based vaccines. However induction of immunity to the vector is a significant obstacle to its repeated use. Here we demonstrate that skin-based delivery of an adenovirus-based malaria vaccine, HAdV5-PyMSP142, to mice using silicon microneedles induces equivalent or enhanced antibody responses to the encoded antigen, however it results in decreased anti-vector responses, compared to intradermal delivery. Microneedle-mediated vaccine priming and resultant induction of low anti-vector antibody titres permitted repeated use of the same adenovirus vaccine vector. This resulted in significantly increased antigen-specific antibody responses in these mice compared to ID-treated mice. Boosting with a heterologous vaccine; MVA-PyMSP142 also resulted in significantly greater antibody responses in mice primed with HAdV5-PyMSP142 using MN compared to the ID route. The highest protection against blood-stage malaria challenge was observed when a heterologous route of immunization (MN/ID) was used. Therefore, microneedle-mediated immunization has potential to both overcome some of the logistic obstacles surrounding needle-and-syringe-based immunization as well as to facilitate the repeated use of the same adenovirus vaccine thereby potentially reducing manufacturing costs of multiple vaccines. This could have important benefits in the clinical ease of use of adenovirus-based immunization strategies. PMID:25142082

  18. Adenovirus serotype 5 vaccine vectors trigger IL-27-dependent inhibitory CD4+ T cell responses that impair CD8+ T cell function

    PubMed Central

    Larocca, Rafael A.; Provine, Nicholas M.; Aid, Malika; Iampietro, M. Justin; Borducchi, Erica N.; Badamchi-Zadeh, Alexander; Abbink, Peter; Ng’ang’a, David; Bricault, Christine A.; Blass, Eryn; Penaloza-MacMaster, Pablo; Stephenson, Kathryn E.; Barouch, Dan H.

    2017-01-01

    Adenovirus serotype 5 (Ad5) vaccine vectors elicit robust CD8+ T cell responses, but these responses typically exhibit a partially exhausted phenotype. However, the immunologic mechanism by which Ad5 vectors induce dysfunctional CD8+ T cells has not previously been elucidated. Here we demonstrate that, following immunization of B6 mice, Ad5 vectors elicit antigen-specific IL-10+CD4+ T cells with a distinct transcriptional profile in a dose-dependent fashion. In rhesus monkeys, we similarly observed upregulated expression of IL-10 and PD-1 by CD4+ T cells following Ad5 vaccination. These cells markedly suppressed vaccine-elicited CD8+ T cell responses in vivo and IL-10 blockade increased the frequency and functionality of antigen-specific CD8+ T cells as well as improved protective efficacy against challenge with recombinant Listeria monocytogenes. Moreover, induction of these inhibitory IL-10+CD4+ T cells correlated with IL-27 expression and IL-27 blockade substantially improved CD4+ T cell functionality. These data highlight a role for IL-27 in the induction of inhibitory IL-10+CD4+ T cells, which suppress CD8+ T cell magnitude and function following Ad5 vector immunization. A deeper understanding of the cytokine networks and transcriptional profiles induced by vaccine vectors should lead to strategies to improve the immunogenicity and protective efficacy of viral vector-based vaccines. PMID:28239679

  19. Cationic lipid-formulated DNA vaccine against hepatitis B virus: immunogenicity of MIDGE-Th1 vectors encoding small and large surface antigen in comparison to a licensed protein vaccine.

    PubMed

    Endmann, Anne; Klünder, Katharina; Kapp, Kerstin; Riede, Oliver; Oswald, Detlef; Talman, Eduard G; Schroff, Matthias; Kleuss, Christiane; Ruiters, Marcel H J; Juhls, Christiane

    2014-01-01

    Currently marketed vaccines against hepatitis B virus (HBV) based on the small (S) hepatitis B surface antigen (HBsAg) fail to induce a protective immune response in about 10% of vaccinees. DNA vaccination and the inclusion of PreS1 and PreS2 domains of HBsAg have been reported to represent feasible strategies to improve the efficacy of HBV vaccines. Here, we evaluated the immunogenicity of SAINT-18-formulated MIDGE-Th1 vectors encoding the S or the large (L) protein of HBsAg in mice and pigs. In both animal models, vectors encoding the secretion-competent S protein induced stronger humoral responses than vectors encoding the L protein, which was shown to be retained mainly intracellularly despite the presence of a heterologous secretion signal. In pigs, SAINT-18-formulated MIDGE-Th1 vectors encoding the S protein elicited an immune response of the same magnitude as the licensed protein vaccine Engerix-B, with S protein-specific antibody levels significantly higher than those considered protective in humans, and lasting for at least six months after the third immunization. Thus, our results provide not only the proof of concept for the SAINT-18-formulated MIDGE-Th1 vector approach but also confirm that with a cationic-lipid formulation, a DNA vaccine at a relatively low dose can elicit an immune response similar to a human dose of an aluminum hydroxide-adjuvanted protein vaccine in large animals.

  20. Stability of vaccinia-vectored recombinant oral rabies vaccine under field conditions: a 3-year study.

    PubMed

    Hermann, Joseph R; Fry, Alethea M; Siev, David; Slate, Dennis; Lewis, Charles; Gatewood, Donna M

    2011-10-01

    Rabies is an incurable zoonotic disease caused by rabies virus, a member of the rhabdovirus family. It is transmitted through the bite of an infected animal. Control methods, including oral rabies vaccination (ORV) programs, have led to a reduction in the spread and prevalence of the disease in wildlife. This study evaluated the stability of RABORAL, a recombinant vaccinia virus vaccine that is used in oral rabies vaccination programs. The vaccine was studied in various field microenvironments in order to describe its viability and facilitate effective baiting strategies. Field microenvironments influenced the stability of this vaccine in this study. This study emphasizes the importance of understanding how vaccines perform under varying field conditions in order to plan effective baiting strategies.

  1. Biosafety aspects of modified vaccinia virus Ankara (MVA)-based vectors used for gene therapy or vaccination.

    PubMed

    Verheust, Céline; Goossens, Martine; Pauwels, Katia; Breyer, Didier

    2012-03-30

    The modified vaccinia virus Ankara (MVA) strain is a highly attenuated strain of vaccinia virus that has been demonstrated to be safe for humans. MVA is widely considered as the vaccinia virus strain of choice for clinical investigation because of its high safety profile. It also represents an excellent candidate for use as vector system in recombinant vaccine development for gene delivery or vaccination against infectious diseases or tumours, even in immunocompromised individuals. The use of MVA and recombinant MVA vectors must comply with various regulatory requirements, particularly relating to the assessment of potential risks for human health and the environment. The purpose of the present paper is to highlight some biological characteristics of MVA and MVA-based recombinant vectors and to discuss these from a biosafety point of view in the context of the European regulatory framework for genetically modified organisms with emphasis on the assessment of potential risks associated with environmental release. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Novel bivalent vectored vaccine for control of myxomatosis and rabbit haemorrhagic disease.

    PubMed

    Spibey, N; McCabe, V J; Greenwood, N M; Jack, S C; Sutton, D; van der Waart, L

    2012-03-24

    A novel, recombinant myxoma virus-rabbit haemorrhagic disease virus (RHDV) vaccine has been developed for the prevention of myxomatosis and rabbit haemorrhagic disease (RHD). A number of laboratory studies are described illustrating the safety and efficacy of the vaccine following subcutaneous administration in laboratory rabbits from four weeks of age onwards. In these studies, both vaccinated and unvaccinated control rabbits were challenged using pathogenic strains of RHD and myxoma viruses, and 100 per cent of the vaccinated rabbits were protected against both myxomatosis and RHD.

  3. Simulations to compare efficacies of tetravalent dengue vaccines and mosquito vector control.

    PubMed

    Thavara, U; Tawatsin, A; Nagao, Y

    2014-06-01

    Infection with dengue, the most prevalent mosquito-borne virus, manifests as dengue fever (DF) or the more fatal dengue haemorrhagic fever (DHF). DHF occurs mainly when an individual who has acquired antibodies to one serotype is inoculated with another serotype. It was reported that mosquito control may have increased the incidence of DF and DHF due to age-dependency in manifesting these illnesses or an immunological mechanism. Tetravalent dengue vaccine is currently being tested in clinical trials. However, seroconversions to all four serotypes were achieved only after three doses. Therefore, vaccines may predispose vaccinees to the risk of developing DHF in future infections. This study employed an individual-based computer simulation, to emulate mosquito control and vaccination, incorporating seroconversion rates reported from actual clinical trials. It was found that mosquito control alone would have increased incidence of DF and DHF in areas of high mosquito density. A vaccination programme with very high coverage, even with a vaccine of suboptimal seroconversion rates, attenuated possible surges in the incidence of DF and DHF which would have been caused by insufficient reduction in mosquito abundance. DHF cases attributable to vaccine-derived enhancement were fewer than DHF cases prevented by a vaccine with considerably high (although not perfect) seroconversion rates. These predictions may justify vaccination programmes, at least in areas of high mosquito abundance. In such areas, mosquito control programmes should be conducted only after the vaccination programme with a high coverage has been initiated.

  4. Vesicular Stomatitis Virus-Vectored Multi-Antigen Tuberculosis Vaccine Limits Bacterial Proliferation in Mice following a Single Intranasal Dose

    PubMed Central

    Zhang, Ming; Dong, Chunsheng; Xiong, Sidong

    2017-01-01

    Tuberculosis (TB) remains a serious health problem worldwide, and an urgent need exists to improve or replace the available vaccine, Mycobacterium bovis bacillus Calmette-Guérin (BCG). Most vaccination protocols adapt two or three doses to induce long-term lasting immunity. Our previous study showed that the naked DNA encoding the triple-antigen fusion TFP846 (Rv3615c-Mtb10.4-Rv2660c) induced robust T cellular immune responses accompanying four inoculations against mycobacteria infection. However, a number of compliance issues exist in some areas lacking the appropriate medical infrastructure with multiple administrations. In this study, a novel vesicular stomatitis virus expressing TFP846 (VSV-846) was developed and the immune responses elicited by VSV-846 were evaluated. We observed that intranasal delivery of VSV-846 induced a potent antigen-specific T cell response following a single dose and VSV-846 efficiently controlled bacterial growth to levels ~10-fold lower than that observed in the mock group 6 weeks post-infection in BCG-infected mice. Importantly, mice immunized with VSV-846 provided long-term protection against mycobacteria infection compared with those receiving p846 or BCG immunization. Increased memory T cells were also observed in the spleens of VSV-846-vaccinated mice, which could be a potential mechanism associated with long-term protective immune response. These findings supported the use of VSV as an antigen delivery vector with the potential for TB vaccine development. PMID:28224119

  5. Safety and Immunogenicity Study of Multiclade HIV-1 Adenoviral Vector Vaccine Alone or as Boost following a Multiclade HIV-1 DNA Vaccine in Africa

    PubMed Central

    Allen, Susan; Than, Soe; Adams, Elizabeth M.; Graham, Barney S.; Koup, Richard A.; Bailer, Robert T.; Smith, Carol; Dally, Len; Tarragona-Fiol, Tony; Bergin, Philip J.; Hayes, Peter; Ho, Martin; Loughran, Kelley; Komaroff, Wendy; Stevens, Gwynneth; Thomson, Helen; Boaz, Mark J.; Cox, Josephine H.; Schmidt, Claudia; Gilmour, Jill; Nabel, Gary J.; Fast, Patricia

    2010-01-01

    Background We conducted a double-blind, randomized, placebo-controlled Phase I study of a recombinant replication-defective adenovirus type 5 (rAd5) vector expressing HIV-1 Gag and Pol from subtype B and Env from subtypes A, B and C, given alone or as boost following a DNA plasmid vaccine expressing the same HIV-1 proteins plus Nef, in 114 healthy HIV-uninfected African adults. Methodology/Principal Findings Volunteers were randomized to 4 groups receiving the rAd5 vaccine intramuscularly at dosage levels of 1×1010 or 1×1011 particle units (PU) either alone or as boost following 3 injections of the DNA vaccine given at 4 mg/dose intramuscularly by needle-free injection using Biojector® 2000. Safety and immunogenicity were evaluated for 12 months. Both vaccines were well-tolerated. Overall, 62% and 86% of vaccine recipients in the rAd5 alone and DNA prime - rAd5 boost groups, respectively, responded to the HIV-1 proteins by an interferon-gamma (IFN-γ) ELISPOT. The frequency of immune responses was independent of rAd5 dosage levels. The highest frequency of responses after rAd5 alone was detected at 6 weeks; after DNA prime - rAd5 boost, at 6 months (end of study). At baseline, neutralizing antibodies against Ad5 were present in 81% of volunteers; the distribution was similar across the 4 groups. Pre-existing immunity to Ad5 did not appear to have a significant impact on reactogenicity or immune response rates to HIV antigens by IFN-γ ELISPOT. Binding antibodies against Env were detected in up to 100% recipients of DNA prime - rAd5 boost. One volunteer acquired HIV infection after the study ended, two years after receipt of rAd5 alone. Conclusions/Significance The HIV-1 rAd5 vaccine, either alone or as a boost following HIV-1 DNA vaccine, was well-tolerated and immunogenic in African adults. DNA priming increased the frequency and magnitude of cellular and humoral immune responses, but there was no effect of rAd5 dosage on immunogenicity endpoints. Trial

  6. Combination of Two Marek's Disease Virus Vectors Shows Effective Vaccination Against Marek's Disease, Infectious Bursal Disease, and Newcastle Disease.

    PubMed

    Ishihara, Yukari; Esaki, Motoyuki; Saitoh, Shuji; Yasuda, Atsushi

    2016-06-01

    Herpesvirus of turkeys (HVT) is a widely used vector for poultry vaccines. However, different HVTs expressing different foreign antigens cannot always be used simultaneously because of the risk of recombination and interference. In this study, we inoculated a mixture of an HVT-expressing the antigen of Newcastle disease virus (NDV; HVT/ND) and Marek's disease virus (MDV) serotype 1 Rispens virus expressing the antigen of infectious bursal disease virus (IBD; Ripens/IBD) into chickens. This mixture showed 94%, 100%, or 94% protection against MDV, IBDV, or NDV challenge, respectively. In conclusion, the combination of Rispens/IBD and HVT/ND is effective for vaccination against MDV, IBDV, and NDV without significant interference.

  7. Room Temperature Stabilization of Oral, Live Attenuated Salmonella enterica serovar Typhi-Vectored Vaccines

    PubMed Central

    Ohtake, Satoshi; Martin, Russell; Saxena, Atul; Pham, Binh; Chiueh, Gary; Osorio, Manuel; Kopecko, Dennis; Xu, DeQi; Lechuga-Ballesteros, David; Truong-Le, Vu

    2011-01-01

    Foam drying, a modified freeze drying process, was utilized to produce a heat-stable, live attenuated Salmonella Typhi ‘Ty21a’ bacterial vaccine. Ty21a vaccine was formulated with pharmaceutically approved stabilizers, including sugars, plasticizers, amino acids, and proteins. Growth media and harvesting conditions of the bacteria were also studied to enhance resistance to desiccation stress encountered during processing as well as subsequent storage at elevated temperatures. The optimized Ty21a vaccine, formulated with trehalose, methionine, and gelatin, demonstrated stability for approximately 12 weeks at 37°C (i.e., time required for the vaccine to decrease in potency by 1log10 CFU) and no loss in titer at 4 and 25°C following storage for the same duration. Furthermore, the foam dried Ty21a elicited a similar immunogenic response in mice as well as protection in challenge studies compared to Vivotif™, the commercial Ty21a vaccine. The enhanced heat stability of the Ty21a oral vaccine, or Ty21a derivatives expressing foreign antigens (e.g. anthrax), could mitigate risks of vaccine potency loss during long term storage, shipping, delivery to geographical areas with warmer climates or during emergency distribution following a bioterrorist attack. Because the foam drying process is conducted using conventional freeze dryers and can be readily implemented at any freeze drying manufacturing facility, this technology appears ready and appropriate for large scale processing of foam dried vaccines. PMID:21300096

  8. Multiple efficacy studies of an adenovirus-vectored foot-and-mouth disease virus serotype A24 subunit vaccine in cattle using homologous challenge.

    PubMed

    Schutta, Christopher; Barrera, José; Pisano, Melia; Zsak, Laszlo; Grubman, Marvin J; Mayr, Gregory A; Moraes, Mauro P; Kamicker, Barbara J; Brake, David A; Ettyreddy, Damodar; Brough, Douglas E; Butman, Bryan T; Neilan, John G

    2016-06-08

    The safety and efficacy of an experimental, replication-deficient, human adenovirus-vectored foot-and-mouth disease virus (FMDV) serotype A24 Cruzeiro capsid-based subunit vaccine (AdtA24) was examined in eight independent cattle studies. AdtA24 non-adjuvanted vaccine was administered intramuscularly to a total of 150 steers in doses ranging from approximately 1.0×10(8) to 2.1×10(11) particle units per animal. No detectable local or systemic reactions were observed after vaccination. At 7 days post-vaccination (dpv), vaccinated and control animals were challenged with FMDV serotype A24 Cruzeiro via the intradermal lingual route. Vaccine efficacy was measured by FMDV A24 serum neutralizing titers and by protection from clinical disease and viremia after challenge. The results of eight studies demonstrated a strong correlation between AdtA24 vaccine dose and protection from clinical disease (R(2)=0.97) and viremia (R(2)=0.98). There was also a strong correlation between FMDV A24 neutralization titers on day of challenge and protection from clinical disease (R(2)=0.99). Vaccination with AdtA24 enabled differentiation of infected from vaccinated animals (DIVA) as demonstrated by the absence of antibodies to the FMDV nonstructural proteins in vaccinates prior to challenge. Lack of AdtA24 vaccine shedding after vaccination was indicated by the absence of neutralizing antibody titers to both the adenovector and FMDV A24 Cruzeiro in control animals after co-mingling with vaccinated cattle for three to four weeks. In summary, a non-adjuvanted AdtA24 experimental vaccine was shown to be safe, immunogenic, consistently protected cattle at 7 dpv against direct, homologous FMDV challenge, and enabled differentiation of infected from vaccinated cattle prior to challenge.

  9. Lentiviral vector-based prime/boost vaccination against AIDS: pilot study shows protection against Simian immunodeficiency virus SIVmac251 challenge in macaques.

    PubMed

    Beignon, Anne-Sophie; Mollier, Karine; Liard, Christelle; Coutant, Frédéric; Munier, Sandie; Rivière, Julie; Souque, Philippe; Charneau, Pierre

    2009-11-01

    AIDS vaccination has a pressing need for more potent vaccination vectors capable of eliciting strong, diversified, and long-lasting cellular immune responses against human immunodeficiency virus (HIV). Lentiviral vectors have demonstrated efficiency not only as gene delivery vehicles for gene therapy applications but also as vaccination tools. This is likely due to their ability to transduce nondividing cells, including dendritic cells, enabling sustained endogenous antigen presentation and thus the induction of high proportions of specific cytotoxic T cells and long-lasting memory T cells. We show in a first proof-of-concept pilot study that a prime/boost vaccination strategy using lentiviral vectors pseudotyped with a glycoprotein G from two non-cross-reactive vesicular stomatitis virus serotypes elicited robust and broad cellular immune responses against the vector-encoded antigen, simian immunodeficiency virus (SIV) GAG, in cynomolgus macaques. Vaccination conferred strong protection against a massive intrarectal challenge with SIVmac251, as evidenced both by the reduction of viremia at the peak of acute infection (a mean of over 2 log(10) fold reduction) and by the full preservation of the CD28(+) CD95(+) memory CD4(+) T cells during the acute phase, a strong correlate of protection against pathogenesis. Although vaccinees continued to display lower viremia than control macaques during the early chronic phase, these differences were not statistically significant by day 50 postchallenge. A not-optimized SIV GAG antigen was chosen to show the strong potential of the lentiviral vector system for vaccination. Given that a stronger protection can be anticipated from a modern HIV-1 antigen design, gene transfer vectors derived from HIV-1 appear as promising candidates for vaccination against HIV-1 infection.

  10. The successful induction of T-cell and antibody responses by a recombinant measles virus-vectored tetravalent dengue vaccine provides partial protection against dengue-2 infection

    PubMed Central

    Hu, Hui-Mei; Chen, Hsin-Wei; Hsiao, Yu-Ju; Wu, Szu-Hsien; Chung, Han-Hsuan; Hsieh, Chun-Hsiang; Chong, Pele; Leng, Chih-Hsiang; Pan, Chien-Hsiung

    2016-01-01

    ABSTRACT Dengue has a major impact on global public health, and the use of dengue vaccine is very limited. In this study, we evaluated the immunogenicity and protective efficacy of a dengue vaccine made from a recombinant measles virus (MV) that expresses envelope protein domain III (ED3) of dengue-1 to 4. Following immunization with the MV-vectored dengue vaccine, mice developed specific interferon-gamma and antibody responses against dengue virus and MV. Neutralizing antibodies against MV and dengue viruses were also induced, and protective levels of FRNT50 ≥ 10 to 4 serotypes of dengue viruses were detected in the MV-vectored dengue vaccine-immunized mice. In addition, specific interferon-gamma and antibody responses to dengue viruses were still induced by the MV-vectored dengue vaccine in mice that were pre-infected with MV. This finding suggests that the pre-existing immunity to MV did not block the initiation of immune responses. By contrast, mice that were pre-infected with dengue-3 exhibited no effect in terms of their antibody responses to MV and dengue viruses, but a dominant dengue-3-specific T-cell response was observed. After injection with dengue-2, a detectable but significantly lower viremia and a higher titer of anti-dengue-2 neutralizing antibodies were observed in MV-vectored dengue vaccine-immunized mice versus the vector control, suggesting that an anamnestic antibody response that provided partial protection against dengue-2 was elicited. Our results with regard to T-cell responses and the effect of pre-immunity to MV or dengue viruses provide clues for the future applications of an MV-vectored dengue vaccine. PMID:26901482

  11. Impact of preexisting adenovirus vector immunity on immunogenicity and protection conferred with an adenovirus-based H5N1 influenza vaccine.

    PubMed

    Pandey, Aseem; Singh, Neetu; Vemula, Sai V; Couëtil, Laurent; Katz, Jacqueline M; Donis, Ruben; Sambhara, Suryaprakash; Mittal, Suresh K

    2012-01-01

    The prevalence of preexisting immunity to adenoviruses in the majority of the human population might adversely impact the development of adaptive immune responses against adenovirus vector-based vaccines. To address this issue, we primed BALB/c mice either intranasally (i.n.) or intramuscularly (i.m.) with varying doses of wild type (WT) human adenovirus subtype 5 (HAd5). Following the development of immunity against HAd5, we immunized animals via the i.n. or i.m. route of inoculation with a HAd vector (HAd-HA-NP) expressing the hemagglutinin (HA) and nucleoprotein (NP) of A/Vietnam/1203/04 (H5N1) influenza virus. The immunogenicity and protection results suggest that low levels of vector immunity (<520 virus-neutralization titer) induced by priming mice with up to 10(7) plaque forming units (p.f.u.) of HAd-WT did not adversely impact the protective efficacy of the vaccine. Furthermore, high levels of vector immunity (approximately 1500 virus-neutralization titer) induced by priming mice with 10(8) p.f.u. of HAd-WT were overcome by either increasing the vaccine dose or using alternate routes of vaccination. A further increase in the priming dose to 10(9) p.f.u. allowed only partial protection. These results suggest possible strategies to overcome the variable levels of human immunity against adenoviruses, leading to better utilization of HAd vector-based vaccines.

  12. Use of DNA and recombinant canarypox viral (ALVAC) vectors for equine herpes virus vaccination.

    PubMed

    Minke, J M; Fischer, L; Baudu, Ph; Guigal, P M; Sindle, T; Mumford, J A; Audonnet, J C

    2006-05-15

    In this study, experimental canarypox virus (ALVAC) and plasmid DNA recombinant vaccines expressing the gB, gC and gD glycoproteins of EHV-1 were assessed for their ability to protect conventional ponies against a respiratory challenge with EHV-1. In addition, potential means of enhancing serological responses in horses to ALVAC and DNA vaccination were explored. These included co-administration of the antigen with conventional adjuvants, complexation with DMRIE-DOPE and co-expression of the antigen along with equine GM-CSF. Groups of EHV primed ponies were vaccinated twice intra-muscularly with one dose of the appropriate test vaccine at an interval of 5 weeks. Two to 3 weeks after the second vaccination, ponies were infected intra-nasally with the virulent Ab4 strain of EHV-1 after which they were observed clinically and sampled for virological investigations. The results demonstrated that DNA and ALVAC vaccination markedly reduced virus excretion after challenge in terms of duration and magnitude, but failed to protect against cell-associated viremia. Noteworthy was the almost complete absence of virus excretion in the group of ponies vaccinated with ALVAC-EHV in the presence of Carbopol adjuvant or DNA plasmid formulated with aluminium phosphate. The administration of the DNA vaccine in the presence of GM-CSF and formulated in DMRIE-DOPE and of the ALVAC vaccine in the presence of Carbopol adjuvant significantly improved virus neutralising antibody responses to EHV-1. These findings indicate that DNA and ALVAC vaccination is a promising approach for the immunological control of EHV-1 infection, but that more research is needed to identify the immunodominant protective antigens of EHV-1 and their interaction with the equine immune system.

  13. Transfected Babesia bovis Expressing a Tick GST as a Live Vector Vaccine

    PubMed Central

    Oldiges, Daiane P.; Laughery, Jacob M.; Tagliari, Nelson Junior; Leite Filho, Ronaldo Viana; Davis, William C.; da Silva Vaz, Itabajara; Termignoni, Carlos; Knowles, Donald P.; Suarez, Carlos E.

    2016-01-01

    The Rhipicephalus microplus tick is a notorious blood-feeding ectoparasite of livestock, especially cattle, responsible for massive losses in animal production. It is the main vector for transmission of pathogenic bacteria and parasites, including Babesia bovis, an intraerythrocytic apicomplexan protozoan parasite responsible for bovine Babesiosis. This study describes the development and testing of a live B. bovis vaccine expressing the protective tick antigen glutathione-S-transferase from Haemaphysalis longicornis (HlGST). The B. bovis S74-T3B parasites were electroporated with a plasmid containing the bidirectional Ef-1α (elongation factor 1 alpha) promoter of B. bovis controlling expression of two independent genes, the selectable marker GFP-BSD (green fluorescent protein–blasticidin deaminase), and HlGST fused to the MSA-1 (merozoite surface antigen 1) signal peptide from B. bovis. Electroporation followed by blasticidin selection resulted in the emergence of a mixed B. bovis transfected line (termed HlGST) in in vitro cultures, containing parasites with distinct patterns of insertion of both exogenous genes, either in or outside the Ef-1α locus. A B. bovis clonal line termed HlGST-Cln expressing intracellular GFP and HlGST in the surface of merozoites was then derived from the mixed parasite line HlGST using a fluorescent activated cell sorter. Two independent calf immunization trials were performed via intravenous inoculation of the HlGST-Cln and a previously described control consisting of an irrelevant transfected clonal line of B. bovis designated GFP-Cln. The control GFP-Cln line contains a copy of the GFP-BSD gene inserted into the Ef-1α locus of B. bovis in an identical fashion as the HIGST-Cln parasites. All animals inoculated with the HlGST-Cln and GFP-Cln transfected parasites developed mild babesiosis. Tick egg fertility and fully engorged female tick weight was reduced significantly in R. microplus feeding on HlGST-Cln-immunized calves

  14. Novel vector vaccine against Brucella abortus based on influenza A viruses expressing Brucella L7/L12 or Omp16 proteins: evaluation of protection in pregnant heifers.

    PubMed

    Tabynov, Kaissar; Yespembetov, Bolat; Sansyzbay, Abylai

    2014-10-14

    The present study provides the first information about the protection of a novel influenza viral vector vaccine expressing the Brucella proteins ribosomal L7/L12 or Omp16 containing the adjuvant Montanide Gel01 in pregnant heifers. Immunization of pregnant heifers was conducted via the conjunctival (n=10) or subcutaneous (n=10) route using cross prime and booster vaccination schedules at an interval of 28 days. The vector vaccine was evaluated in comparison with positive control groups vaccinated with Brucella abortus S19 (n=10) or B. abortus RB51 (n=10) and a negative (PBS+Montanide Gel01; n=10) control group. Via both the conjunctival or subcutaneous route, evaluation of protectiveness against abortion, effectiveness of vaccination and index of infection (in heifers and their fetuses or calves) demonstrated the vector vaccine provided good protection against B. abortus 544 infection compared to the negative control group (PBS+Montanide Gel01) and comparable protection to commercial vaccines B. abortus S19 or B. abortus RB51.

  15. CD40 Ligand enhances immunogenicity of vector-based vaccines in immunocompetent and CD4+ T cell deficient individuals

    PubMed Central

    Auten, Matthew W.; Huang, Weitao; Dai, Guixiang; Ramsay, Alistair J.

    2012-01-01

    Impairment of host immunity, particularly CD4+ T cell deficiency, presents significant complications for vaccine immunogenicity and efficacy. CD40 ligand (CD40L or CD154), a member of the tumor necrosis factor superfamily (TNFSF), is an important co-stimulatory molecule and, through interactions with its cognate receptor CD40, plays a pivotal role in the generation of host immune responses. Exploitation of CD40L and its receptor CD40 could provide a means to enhance and potentially restore protective immune responses in CD4+ T cell deficiency. To investigate the potential adjuvanticity of CD40L, we constructed recombinant plasmid DNA and adenoviral (Ad) vaccine vectors expressing murine CD40L and the mycobacterial protein antigen 85B (Ag85B). Co-immunization of mice with CD40L and Ag85B by intranasal or intramuscular prime-boosting led to route-dependent enhancement of the magnitude of vaccine-induced circulating and lung mucosal CD4+ and CD8+ T cell responses in both normal (CD4-replete) and CD4+ T cell deficient animals, including polyfunctional T cell responses. The presence of CD40L alone was insufficient to enhance or restore CD4+ T cell responses in CD4-ablated animals; however, in partially-depleted animals, co-immunization with Ag85B and CD40L was capable of eliciting enhanced T cell responses, similar to those observed in normal animals, when compared to those given vaccine antigen alone. In summary, these findings show that CD40L has the capacity to enhance the magnitude of vaccine-induced polyfunctional T cell responses in CD4+ T cell deficient mice, and warrants further study as an adjuvant for immunization against opportunistic pathogens in individuals with CD4+ T cell deficiency. PMID:22349523

  16. Comparative Efficacy of Feline Leukemia Virus (FeLV) Inactivated Whole-Virus Vaccine and Canarypox Virus-Vectored Vaccine during Virulent FeLV Challenge and Immunosuppression.

    PubMed

    Patel, M; Carritt, K; Lane, J; Jayappa, H; Stahl, M; Bourgeois, M

    2015-07-01

    Four vaccines for feline leukemia virus (FeLV) are available in the United States. This study's purpose was to compare the efficacy of Nobivac feline 2-FeLV (an inactivated, adjuvanted whole-virus vaccine) and PureVax recombinant FeLV (a live, canarypox virus-vectored vaccine) following FeLV challenge. Cats were vaccinated at 9 and 12 weeks with Nobivac feline 2-FeLV (group A, n = 11) or PureVax recombinant FeLV (group B, n = 10). Group C (n = 11) comprised unvaccinated controls. At 3 months postvaccination, cats were immunosuppressed and challenged with FeLV-A/61E. The outcomes measured were persistent antigenemia at 12 weeks postchallenge (PC) and proviral DNA and viral RNA at 3 to 9 weeks PC. Persistent antigenemia was observed in 0 of 11 cats in group A, 5 of 10 cats in group B, and 10 of 11 cats in group C. Group A was significantly protected compared to those in groups B (P < 0.013) and C (P < 0.0001). No difference was found between groups B and C (P > 0.063). The preventable fraction was 100% for group A and 45% for group B. At 9 weeks PC, proviral DNA and viral RNA were detected 1 of 11 cats in group A, 6 of 10 cats in group B, and 9 of 11 cats in group C. Nucleic acid loads were significantly lower in group A than in group C (P < 0.01). Group A had significantly lower proviral DNA loads than group B at weeks 6 to 9 (P < 0.02). The viral RNA loads were significantly lower in group A than in group B at weeks 7 to 9 (P < 0.01). The results demonstrate that Nobivac feline 2-FeLV-vaccinated cats were fully protected against persistent antigenemia and had significantly smaller amounts of proviral DNA and plasma viral RNA loads than PureVax recombinant FeLV-vaccinated cats and unvaccinated controls. Copyright © 2015, Patel et al.

  17. Vaccination to conserved influenza antigens in mice using a novel Simian adenovirus vector, PanAd3, derived from the bonobo Pan paniscus.

    PubMed

    Vitelli, Alessandra; Quirion, Mary R; Lo, Chia-Yun; Misplon, Julia A; Grabowska, Agnieszka K; Pierantoni, Angiolo; Ammendola, Virginia; Price, Graeme E; Soboleski, Mark R; Cortese, Riccardo; Colloca, Stefano; Nicosia, Alfredo; Epstein, Suzanne L

    2013-01-01

    Among approximately 1000 adenoviruses from chimpanzees and bonobos studied recently, the Pan Adenovirus type 3 (PanAd3, isolated from a bonobo, Pan paniscus) has one of the best profiles for a vaccine vector, combining potent transgene immunogenicity with minimal pre-existing immunity in the human population. In this study, we inserted into a replication defective PanAd3 a transgene expressing a fusion protein of conserved influenza antigens nucleoprotein (NP) and matrix 1 (M1). We then studied antibody and T cell responses as well as protection from challenge infection in a mouse model. A single intranasal administration of PanAd3-NPM1 vaccine induced strong antibody and T cell responses, and protected against high dose lethal influenza virus challenge. Thus PanAd3 is a promising candidate vector for vaccines, including universal influenza vaccines.

  18. Vaccination to Conserved Influenza Antigens in Mice Using a Novel Simian Adenovirus Vector, PanAd3, Derived from the Bonobo Pan paniscus

    PubMed Central

    Vitelli, Alessandra; Quirion, Mary R.; Lo, Chia-Yun; Misplon, Julia A.; Grabowska, Agnieszka K.; Pierantoni, Angiolo; Ammendola, Virginia; Price, Graeme E.; Soboleski, Mark R.; Cortese, Riccardo; Colloca, Stefano; Nicosia, Alfredo; Epstein, Suzanne L.

    2013-01-01

    Among approximately 1000 adenoviruses from chimpanzees and bonobos studied recently, the Pan Adenovirus type 3 (PanAd3, isolated from a bonobo, Pan paniscus) has one of the best profiles for a vaccine vector, combining potent transgene immunogenicity with minimal pre-existing immunity in the human population. In this study, we inserted into a replication defective PanAd3 a transgene expressing a fusion protein of conserved influenza antigens nucleoprotein (NP) and matrix 1 (M1). We then studied antibody and T cell responses as well as protection from challenge infection in a mouse model. A single intranasal administration of PanAd3-NPM1 vaccine induced strong antibody and T cell responses, and protected against high dose lethal influenza virus challenge. Thus PanAd3 is a promising candidate vector for vaccines, including universal influenza vaccines. PMID:23536756

  19. Optimization of Plasmid Maintenance in the Attenuated Live Vector Vaccine Strain Salmonella typhi CVD 908-htrA†

    PubMed Central

    Galen, James E.; Nair, Jay; Wang, Jin Yuang; Wasserman, Steven S.; Tanner, Michael K.; Sztein, Marcelo B.; Levine, Myron M.

    1999-01-01

    The broad objective of the research presented here is to develop a noncatalytic plasmid maintenance system for the stabilization of multicopy expression plasmids encoding foreign antigens in a Salmonella typhi live-vector vaccine strain such as CVD 908-htrA. We have enhanced the maintenance of expression plasmids at two independent levels. First, we removed dependence upon balanced-lethal maintenance systems that involve catalytic enzymes expressed from multicopy plasmids; we accomplished this through incorporation into expression plasmids of a postsegregational killing system based on the noncatalytic hok-sok plasmid addiction system from the antibiotic resistance factor pR1. We also included at least one naturally occurring plasmid partition function in our expression plasmids, which eliminates random segregation of these plasmids, thereby enhancing their inheritance and stability; to accomplish this, we incorporated either the par locus from pSC101, the parA locus from pR1, or both. We monitored the stability of optimized expression plasmids within CVD 908-htrA by quantitating expression of a variant of green fluorescent protein (GFPuv) by using flow cytometry. In this report, we demonstrate the utility of this novel plasmid maintenance system in enhancing the stability of our expression plasmids and go on to show that as the copy number of stabilized plasmids increases, the toxicity of GFPuv synthesis also increases. The implications of these observations for the rational design of immunogenic and protective bacterial live vector vaccines are discussed. PMID:10569759

  20. Construction of stable producer cells to make high-titer lentiviral vectors for dendritic cell-based vaccination.

    PubMed

    Lee, Chi-Lin; Chou, Michael; Dai, Bingbing; Xiao, Liang; Wang, Pin

    2012-06-01

    Lentiviral vectors (LVs) enveloped with an engineered Sindbis virus glycoprotein can specifically bind to dendritic cells (DCs) through the surface receptor DC-SIGN and induce antigen expression, thus providing an efficient method for delivering DC-directed vaccines. In this study, we constructed a stable producer line (LV-MGFP) for synthesizing DC-SIGN-targeted HIV-1-based LVs (DC-LVs) encoding green fluorescent protein (GFP) by a concatemeric array transfection technique. We demonstrated that the established stable clones could routinely produce vector supernatants with titers above 10(7) transduction units per milliliter (TU/mL) during a continuous 3-month cell passage. The producer cells were also capable of generating similar titers of DC-LVs in serum-free medium. Moreover, the addition of 1-deoxymannojirimycin (DMJ) enabled the producer cells to manufacture DC-LVs with both improved titers and enhanced potency to evoke antigen-specific CD8(+) T cell responses in mice. The stable lines could accommodate the replacement of the internal murine stem cell virus (MSCV) promoter with the human ubiquitin-C (Ubi) promoter in the lentiviral backbone. The resulting DC-LVs bearing Ubi exhibited the enhanced potency to elicit vaccine-specific immunity. Based on accumulated evidence, our studies support the application of this production method in manufacturing DC-LVs for preclinical and clinical testing of novel DC-based immunization. Copyright © 2011 Wiley Periodicals, Inc.

  1. Evaluation of the Efficacy, Potential for Vector Transmission, and Duration of Immunity of MP-12, an Attenuated Rift Valley Fever Virus Vaccine Candidate, in Sheep

    DTIC Science & Technology

    2015-08-01

    there are susceptible ruminant hosts and competent mosquito vectors, yet there are no fully licensed animal vaccines for this arthropod-borne virus...vaccine’s potential to infect mosquitoes , the duration of humoral immunity to 24 months postvaccination, and the ability to prevent disease and viremia from... mosquito species. Neutralizing antibodies were elicited, with titers of>1:40 still present at 24 months postvaccination. Vaccinates were protected from

  2. Safety and Immunogenicity of a Recombinant Adenovirus Serotype 35-Vectored HIV-1 Vaccine in Adenovirus Serotype 5 Seronegative and Seropositive Individuals

    PubMed Central

    Fuchs, Jonathan D; Bart, Pierre-Alexandre; Frahm, Nicole; Morgan, Cecilia; Gilbert, Peter B; Kochar, Nidhi; DeRosa, Stephen C; Tomaras, Georgia D; Wagner, Theresa M; Baden, Lindsey R; Koblin, Beryl A; Rouphael, Nadine G; Kalams, Spyros A; Keefer, Michael C; Goepfert, Paul A; Sobieszczyk, Magdalena E; Mayer, Kenneth H; Swann, Edith; Liao, Hua-Xin; Haynes, Barton F; Graham, Barney S; McElrath, M Juliana

    2015-01-01

    Background Recombinant adenovirus serotype 5 (rAd5)-vectored HIV-1 vaccines have not prevented HIV-1 infection or disease and pre-existing Ad5 neutralizing antibodies may limit the clinical utility of Ad5 vectors globally. Using a rare Ad serotype vector, such as Ad35, may circumvent these issues, but there are few data on the safety and immunogenicity of rAd35 directly compared to rAd5 following human vaccination. Methods HVTN 077 randomized 192 healthy, HIV-uninfected participants into one of four HIV-1 vaccine/placebo groups: rAd35/rAd5, DNA/rAd5, and DNA/rAd35 in Ad5-seronegative persons; and DNA/rAd35 in Ad5-seropositive persons. All vaccines encoded the HIV-1 EnvA antigen. Antibody and T-cell responses were measured 4 weeks post boost immunization. Results All vaccines were generally well tolerated and similarly immunogenic. As compared to rAd5, rAd35 was equally potent in boosting HIV-1-specific humoral and cellular immunity and responses were not significantly attenuated in those with baseline Ad5 seropositivity. Like DNA, rAd35 efficiently primed rAd5 boosting. All vaccine regimens tested elicited cross-clade antibody responses, including Env V1/V2-specific IgG responses. Conclusions Vaccine antigen delivery by rAd35 is well-tolerated and immunogenic as a prime to rAd5 immunization and as a boost to prior DNA immunization with the homologous insert. Further development of rAd35-vectored prime-boost vaccine regimens is warranted. PMID:26587311

  3. Immune Signature of Enhanced Functional Avidity CD8+ T Cells in vivo Induced by Vaccinia Vectored Vaccine

    PubMed Central

    Hu, Zhidong; Zhu, Lingyan; Wang, Jing; Wan, Yanmin; Yuan, Songhua; Chen, Jian; Ding, Xiangqing; Qiu, Chenli; Zhang, Xiaoyan; Qiu, Chao; Xu, Jianqing

    2017-01-01

    Functional avidity of T cells is a critical determinant for clearing viral infection and eliminating tumor. Understanding how functional avidity is maintained in T cells is imperative for immunotherapy. However, studies systematically characterize T cell with high functional avidity induced in vivo are still lacking. Previously, we and others found vaccinia vectored vaccine (VACV) induced antigen-specific CD8+ T cells with relatively high functional avidity to those from DNA vaccine. Herein, we used functional, immune phenotyping and transcriptomic studies to define the immune signature of these CD8+ T cells with high functional avidity. Antigen-specific CD8+ T cells induced by VACV executed superior in vivo killing activity and displayed a distinct transcriptional profile, whereas no significantly differences were found in composition of memory sub-populations and cytokine poly-functionality. Transcriptional analyses revealed unique features of VACV induced CD8+ T cells in several biological processes, including transport, cell cycle, cell communication and metabolic processes. In summary, we characterize CD8+ T cells of high functional avidity induced in vivo by VACV, which not only improves our understanding of adaptive T cell immunity in VACV vaccination, but also provides clues to modulate functional avidity of CD8+ T cells for T cell based immunotherapy. PMID:28155878

  4. SARS vaccine based on a replication-defective recombinant vesicular stomatitis virus is more potent than one based on a replication-competent vector.

    PubMed

    Kapadia, Sagar U; Simon, Ian D; Rose, John K

    2008-06-20

    A SARS vaccine based on a live-attenuated vesicular stomatitis virus (VSV) recombinant expressing the SARS-CoV S protein provides long-term protection of immunized mice from SARS-CoV infection (Kapadia, S.U., Rose, J. K., Lamirande, E., Vogel, L., Subbarao, K., Roberts, A., 2005. Long-term protection from SARS coronavirus infection conferred by a single immunization with an attenuated VSV-based vaccine. Virology 340(2), 174-82.). Because it is difficult to obtain regulatory approval of vaccine based on live viruses, we constructed a replication-defective single-cycle VSV vector in which we replaced the VSV glycoprotein (G) gene with the SARS-CoV S gene. The virus was only able to infect cells when pseudotyped with the VSV G protein. We measured the effectiveness of immunization with the single-cycle vaccine in mice. We found that the vaccine given intramuscularly induced a neutralizing antibody response to SARS-CoV that was approximately ten-fold greater than that required for the protection from SARS-CoV infection, and significantly greater than that generated by the replication-competent vector expressing SARS-CoV S protein given by the same route. Our results, along with earlier studies showing potent induction of T-cell responses by single-cycle vectors, indicate that these vectors are excellent alternatives to live-attenuated VSV.

  5. Different HIV pox viral vector-based vaccines and adjuvants can induce unique antigen presenting cells that modulate CD8 T cell avidity.

    PubMed

    Trivedi, Shubhanshi; Jackson, Ronald J; Ranasinghe, Charani

    2014-11-01

    The lung-derived dendritic cell (LDC) recruitment following intranasal (i.n.) vaccination of different poxviral vector-based vaccines/adjuvants were evaluated to decipher how these factors influenced CD8(+) T cell avidity. Compared to the standard i.n. recombinant fowlpox virus (FPV)-HIV vaccination, the FPV-HIV IL-13Rα2 or IL-4Rα antagonist adjuvanted vaccines that induced higher avidity CD8(+) T cells, also recruited significantly elevated MHCII(+) CD11c(+) CD11b(+) CD103(-) CD64(-) MAR-1(-) conventional DC (cDCs) to the lung mucosae (hierarchy: IL-4R antagonist>IL-13Rα2>unadjuvanted). In contrast, elevated CD11b(-) CD103(+) LDCs were detected in animals that received recombinant HIV vaccinia virus (rVV) or Modified Vaccinia Ankara virus (MVA) vector-based vaccines. Adoptive transfer studies indicated that CD11b(-) CD103(+) LDCs significantly dampened HIV-specific CD8(+) T cell avidity compared to CD11b(+) CD103(-) LDCs. Collectively; our observations revealed that rFPV vector prime and transient inhibition of IL-4/IL-13 at the vaccination site favoured the recruitment of unique LDCs, associated with the induction of high quality immunity.

  6. Vaccination of ponies with the IE gene of EHV-1 in a recombinant modified live vaccinia vector protects against clinical and virological disease.

    PubMed

    Soboll, G; Breathnach, C C; Kydd, J H; Hussey, S B; Mealey, R M; Lunn, D P

    2010-05-15

    The control of EHV-1 infection by cytotoxic T-cell responses (CTL) via a reduction in cell associated viremia remains an important goal in horses. Unfortunately, current vaccines are inefficient at inducing these responses. We have identified the immediate early (IE) gene of EHV-1 as a potent stimulator of virus-specific CTL responses in ponies expressing a specific MHC class I serological haplotype (A3/B2). This study was designed to determine if vaccination of A3/B2 MHC I positive ponies with the IE gene could induce protection and immune responses associated with cell mediated immunity. Ponies expressing the MHC-I A3/B2 haplotype (A3/B2 vaccinates) and ponies with a different MHC I haplotype (either non-A3 vaccinates or A3-non-B2 vaccinates) were vaccinated with a recombinant modified vaccinia Ankara (rMVA) vector expressing the IE gene on 3 occasions and vaccinates and unvaccinated controls were challenge infected 8 weeks after the last vaccination. Interferon gamma (IFN-gamma) mRNA and antibody titers were determined throughout the study and clinical signs, nasal virus shedding and viremia were determined following challenge infection. Vaccination of A3/B2 vaccinates conferred significant clinical protection and a significant reduction in EHV-1 viremia. IFN-gamma mRNA increased significantly following vaccination in the A3/B2 vaccinates. Antibody titers remained low until after challenge infection, indicating that no accidental field acquired or recrudescent EHV-1 infection had occurred. In summary, this is an important study showing that vaccination of ponies with the EHV-1 IE protein provides not only reduction in clinical disease but also reduction of cell associated viremia, which is a prerequisite for the prevention of abortion and neurological disease. Copyright 2009 Elsevier B.V. All rights reserved.

  7. A goat poxvirus-vectored peste-des-petits-ruminants vaccine induces long-lasting neutralization antibody to high levels in goats and sheep.

    PubMed

    Chen, Weiye; Hu, Sen; Qu, Linmao; Hu, Qianqian; Zhang, Qian; Zhi, Haibing; Huang, Kehe; Bu, Zhigao

    2010-07-05

    Recombinant capripoxvirus (CPV) is a promising candidate differentiating infected from vaccinated animals (DIVA) vaccine against peste-des-petits-ruminants (PPR). In order for recombinant CPV to be successfully used in the field, there should exist dependable indicators for quality control of vaccine products, surveillance and vaccination evaluation. Viral neutralization antibody (VNA) is correlated to protection against PPR and is a technically feasible indicator for this purpose. The immunogenicity of this vectored vaccine in goats and sheep, however, has not been fully evaluated. In this study, we generated two recombinant CPV viruses, rCPV-PPRVH and rCPV-PPRVF, that express PPR virus (PPRV) glycoproteins H and F, respectively. Vaccination studies with different dosages of recombinant viruses showed that rCPV-PPRVH was a more potent inducer of PPRV VNA than rCPV-PPRVF. One dose of rCPV-PPRVH was enough to seroconvert 80% of immunized sheep. A second dose induced significantly higher PPRV VNA titers. There was no significant difference in PPRV VNA responses between goats and sheep. Subcutaneous inoculation also induced a significant PPRV VNA response. PPRV VNA could be detected for over 6 months in more than 80% of vaccinated goats and sheep. Boost vaccination at 6-month intervals induced significant re-boost efficacy of PPRV VNA in goats and sheep. More over, two doses of rCPV-PPRVH could completely overcome the interference caused by pre-existing immunity to the CPV vaccine backbone in animals. Vaccination with rCPV-PPRVH also protected goats from virulent CPV challenge. Our results demonstrate that VNA can serve as a dependent indicator for effective vaccination and immune protection of animals in the field. The recombinant CPV vaccine used in our studies could be a practical and useful candidate DIVA vaccine in countries where PPR newly emerges or where stamp-out plans are yet to be implemented. Copyright 2010 Elsevier Ltd. All rights reserved.

  8. Antigen discovery and delivery of subunit vaccines by nonliving bacterial ghost vectors.

    PubMed

    Walcher, Petra; Mayr, Ulrike B; Azimpour-Tabrizi, Chakameh; Eko, Francis O; Jechlinger, Wolfgang; Mayrhofer, Peter; Alefantis, Tim; Mujer, Cesar V; DelVecchio, Vito G; Lubitz, Werner

    2004-12-01

    The bacterial ghost (BG) platform system is a novel vaccine delivery system endowed with intrinsic adjuvant properties. BGs are nonliving Gram-negative bacterial cell envelopes which are devoid of their cytoplasmic contents, yet maintain their cellular morphology and antigenic structures, including bioadhesive properties. The main advantages of BGs as carriers of subunit vaccines include their ability to stimulate a high immune response and to target the carrier itself to primary antigen-presenting cells. The intrinsic adjuvant properties of BGs enhance the immune response to target antigens, including T-cell activation and mucosal immunity. Since native and foreign antigens can be carried in the envelope complex of BGs, combination vaccines with multiple antigens of diverse origin can be presented to the immune system simultaneously. Beside the capacity of BGs to function as carriers of protein antigens, they also have a high loading capacity for DNA. Thus, loading BGs with recombinant DNA takes advantage of the excellent bioavailability for DNA-based vaccines and the high expression rates of the DNA-encoded antigens in target cell types such as macrophages and dendritic cells. There are many spaces within BGs including the inner and outer membranes, the periplasmic space and the internal lumen which can carry antigens, DNA or mediators of the immune response. All can be used for subunit antigen to design new vaccine candidates with particle presentation technology. In addition, the fact that BGs can also carry piggyback large-size foreign antigen particles, increases the technologic usefulness of BGs as combination vaccines against viral and bacterial pathogens. Furthermore, the BG antigen carriers can be stored as freeze-dried preparations at room temperature for extended periods without loss of efficacy. The potency, safety and relatively low production cost of BGs offer a significant technical advantage over currently utilized vaccine technologies.

  9. A novel candidate HIV vaccine vector based on the replication deficient Capripoxvirus, Lumpy skin disease virus (LSDV)

    PubMed Central

    2011-01-01

    Background The Capripoxvirus, Lumpy skin disease virus (LSDV) has a restricted host-range and is being investigated as a novel HIV-1 vaccine vector. LSDV does not complete its replication cycle in non-ruminant hosts. Methods The safety of LSDV was tested at doses of 104 and 106 plaque forming units in two strains of immunocompromised mice, namely RAG mice and CD4 T cell knockout mice. LSDV expressing HIV-1 subtype C Gag, reverse transcriptase (RT), Tat and Nef as a polyprotein (Grttn), (rLSDV-grttn), was constructed. The immunogenicity of rLSDV-grttn was tested in homologous prime-boost regimens as well as heterologous prime-boost regimes in combination with a DNA vaccine (pVRC-grttn) or modified vaccinia Ankara vaccine (rMVA-grttn) both expressing Grttn. Results Safety was demonstrated in two strains of immunocompromised mice. In the immunogenicity experiments mice developed high magnitudes of HIV-specific cells producing IFN-gamma and IL-2. A comparison of rLSDV-grttn and rMVA-grttn to boost a DNA vaccine (pVRC-grttn) indicated a DNA prime and rLSDV-grttn boost induced a 2 fold (p < 0.01) lower cumulative frequency of Gag- and RT-specific IFN-γ CD8 and CD4 cells than a boost with rMVA-grttn. However, the HIV-specific cells induced by the DNA vaccine prime rLSDV-grttn boost produced greater than 3 fold (p < 0.01) more IFN- gamma than the HIV-specific cells induced by the DNA vaccine prime rMVA-grttn boost. A boost of HIV-specific CD4 cells producing IL-2 was only achieved with the DNA vaccine prime and rLSDV-grttn boost. Heterologous prime-boost combinations of rLSDV-grttn and rMVA-grttn induced similar cumulative frequencies of IFN- gamma producing Gag- and RT-specific CD8 and CD4 cells. A significant difference (p < 0.01) between the regimens was the higher capacity (2.1 fold) of Gag-and RT-specific CD4 cells to produce IFN-γ with a rMVA-grttn prime - rLSDV-grttn boost. This regimen also induced a 1.5 fold higher (p < 0.05) frequency of Gag- and RT-specific CD

  10. A lentiviral vector-based therapeutic vaccine encoding Ag85B-Rv3425 potently increases resistance to acute tuberculosis infection in mice.

    PubMed

    Yang, Enzhuo; Wang, Feifei; Xu, Ying; Wang, Honghai; Hu, Yong; Shen, Hongbo; Chen, Zheng W

    2015-08-01

    Few treatment options for multidrug-resistant tuberculosis (TB) and extensively drug-resistant TB call attention to the development of novel therapeutic approaches for TB. Therapeutic vaccines are promising candidates because they can induce antigen-specific cellular immune responses, which play an important role in the elimination of Mycobacterium tuberculosis (MTB). In this study, a novel lentiviral vector therapeutic vaccine for delivering MTB-specific fusion protein Ag85B-Rv3425 was constructed. Results showed that one single-injection of this recombinant lentivirus vaccine could trigger antigen-specific Th1-type immune responses in mice. More importantly, mice with acute infection benefited a lot from a single-dose administration of this vaccine by markedly reduced MTB burdens in lungs and spleens as well as attenuated lesions in lungs compared with untreated mice. These results displayed good prospects of this novel vaccine for the immunotherapy of TB.

  11. Vaccine-Induced Immunity in Baboons by Using DNA and Replication-Incompetent Adenovirus Type 5 Vectors Expressing a Human Immunodeficiency Virus Type 1 gag Gene

    PubMed Central

    Casimiro, Danilo R.; Tang, Aimin; Chen, Ling; Fu, Tong-Ming; Evans, Robert K.; Davies, Mary-Ellen; Freed, Daniel C.; Hurni, William; Aste-Amezaga, Jose M.; Guan, Liming; Long, Romnie; Huang, Lingyi; Harris, Virginia; Nawrocki, Denise K.; Mach, Henryk; Troutman, Robert D.; Isopi, Lynne A.; Murthy, Krishna K.; Rice, Karen; Wilson, Keith A.; Volkin, David B.; Emini, Emilio A.; Shiver, John W.

    2003-01-01

    The cellular immunogenicity of formulated plasmid DNA and replication-defective human adenovirus serotype 5 (Ad5) vaccine vectors expressing a codon-optimized human immunodeficiency virus type 1 gag gene was examined in baboons. The Ad5 vaccine was capable of inducing consistently strong, long-lived CD8+-biased T-cell responses and in vitro cytotoxic activities. The DNA vaccine-elicited immune responses were weaker than those elicited by the Ad5 vaccine and highly variable; formulation with chemical adjuvants led to moderate increases in the levels of Gag-specific T cells. Increasing the DNA-primed responses with booster doses of either Ad5 or modified vaccinia virus Ankara vaccines suggests a difference in the relative levels of cytotoxic and helper responses. The implications of these results are discussed. PMID:12805466

  12. Enhancement of Protective Efficacy through Adenoviral Vectored Vaccine Priming and Protein Boosting Strategy Encoding Triosephosphate Isomerase (SjTPI) against Schistosoma japonicum in Mice

    PubMed Central

    Dai, Yang; Wang, Xiaoting; Tang, Jianxia; Zhao, Song; Xing, Yuntian; Dai, Jianrong; Jin, Xiaolin; Zhu, Yinchang

    2015-01-01

    Background Schistosomiasis japonica is a zoonotic parasitic disease; developing transmission blocking veterinary vaccines are urgently needed for the prevention and control of schistosomiasis in China. Heterologous prime-boost strategy, a novel vaccination approach, is more effective in enhancing vaccine efficacy against multiple pathogens. In the present study, we established a novel heterologous prime-boost vaccination strategy, the rAdV-SjTPI.opt intramuscular priming and rSjTPI subcutaneous boosting strategy, and evaluated its protective efficacy against Schistosoma japonicum in mice. Methodology/Principal Findings Adenoviral vectored vaccine (rAdV-SjTPI.opt) and recombinant protein vaccine (rSjTPI) were prepared and used in different combinations as vaccines in a mouse model. The specific immune responses and protective efficacies were evaluated. Furthermore, the longevity of protective efficacy was also determined. Results showed that the rAdV-SjTPI.opt priming-rSjTPI boosting strategy elicited higher levels of specific IgG responses and broad-spectrum specific cellular immune responses. The protective efficacy could reach up to nearly 70% and 50% of protection could be observed at 10 weeks after the last immunization in mice. Conclusions/Significance The rAdV-SjTPI.opt intramuscular priming-rSjTPI subcutaneous boosting vaccination strategy is a novel, highly efficient, and stable approach to developing vaccines against Schistosoma japonicum infections in China. PMID:25793406

  13. Protection against tuberculosis with homologous or heterologous protein/vector vaccine approaches is not dependent on CD8+ T cells.

    PubMed

    Baldwin, Susan L; Ching, Lance K; Pine, Samuel O; Moutaftsi, Magdalini; Lucas, Elyse; Vallur, Aarthy; Orr, Mark T; Bertholet, Sylvie; Reed, Steven G; Coler, Rhea N

    2013-09-01

    Considerable effort has been directed to develop Mycobacterium tuberculosis vaccines to boost bacille Calmette-Guérin or for those who cannot be immunized with bacille Calmette-Guérin. We hypothesized that CD4(+) and CD8(+) T cell responses with a heterologous prime/boost vaccine approach could induce long-lived vaccine efficacy against M. tuberculosis in C57BL/6 mice. We produced an adenovirus vector expressing ID93 (Ad5-ID93) for induction of CD8 T cells to use with our candidate tuberculosis vaccine, ID93/glucopyranosyl lipid adjuvant (GLA)-stable emulsion (SE), which induces potent Th1 CD4 T cells. Ad5-ID93 generates ID93-specific CD8(+) T cell responses and induces protection against M. tuberculosis. When Ad5-ID93 is administered in a prime-boost strategy with ID93/GLA-SE, both CD4(+) and CD8(+) T cells are generated and provide protection against M. tuberculosis. In a MHC class I-deficient mouse model, all groups including the Ad5-ID93 group elicited an Ag-specific CD4(+) T cell response and significantly fewer Ag-specific CD8(+) T cells, but were still protected against M. tuberculosis, suggesting that CD4(+) Th1 T cells could compensate for the loss of CD8(+) T cells. Lastly, the order of the heterologous immunizations was critical. Long-lived vaccine protection was observed only when Ad5-ID93 was given as the boost following an ID93/GLA-SE prime. The homologous ID93/GLA-SE prime/boost regimen also induced long-lived protection. One of the correlates of protection between these two approaches was an increase in the total number of ID93-specific IFN-γ-producing CD4(+) T cells 6 mo following the last immunization. Our findings provide insight into the development of vaccines not only for tuberculosis, but other diseases requiring T cell immunity.

  14. Non-replicating expression vectors: applications in vaccine development and gene therapy

    PubMed Central

    Limbach, K. J.; Paoletti, E.

    1996-01-01

    This review presents experimental, preclinical and clinical data illustrating the multiple uses of recombinant non-replicating virus vectors in the fields of immunoprophylaxis and gene therapy. PMID:8666067

  15. Homologous Boosting with Adenoviral Serotype 5 HIV Vaccine (rAd5) Vector Can Boost Antibody Responses despite Preexisting Vector-Specific Immunity in a Randomized Phase I Clinical Trial

    PubMed Central

    Sarwar, Uzma N.; Novik, Laura; Enama, Mary E.; Plummer, Sarah A.; Koup, Richard A.; Nason, Martha C.; Bailer, Robert T.; McDermott, Adrian B.; Roederer, Mario; Mascola, John R.; Ledgerwood, Julie E.; Graham, Barney S.

    2014-01-01

    Background Needle-free delivery improves the immunogenicity of DNA vaccines but is also associated with more local reactogenicity. Here we report the first comparison of Biojector and needle administration of a candidate rAd5 HIV vaccine. Methods Thirty-one adults, 18–55 years, 20 naive and 11 prior rAd5 vaccine recipients were randomized to receive single rAd5 vaccine via needle or Biojector IM injection at 1010 PU in a Phase I open label clinical trial. Solicited reactogenicity was collected for 5 days; clinical safety and immunogenicity follow-up was continued for 24 weeks. Results Overall, injections by either method were well tolerated. There were no serious adverse events. Frequency of any local reactogenicity was 16/16 (100%) for Biojector compared to 11/15 (73%) for needle injections. There was no difference in HIV Env-specific antibody response between Biojector and needle delivery. Env-specific antibody responses were more than 10-fold higher in subjects receiving a booster dose of rAd5 vaccine than after a single dose delivered by either method regardless of interval between prime and boost. Conclusions Biojector delivery did not improve antibody responses to the rAd5 vaccine compared to needle administration. Homologous boosting with rAd5 gene-based vectors can boost insert-specific antibody responses despite pre-existing vector-specific immunity. Trial Registration Clinicaltrials.gov NCT00709605 NCT00709605 PMID:25264782

  16. First evaluation of an influenza viral vector based Brucella abortus vaccine in sheep and goats: Assessment of safety, immunogenicity and protective efficacy against Brucella melitensis infection.

    PubMed

    Tabynov, Kaissar; Yespembetov, Bolat; Matikhan, Nurali; Ryskeldinova, Sholpan; Zinina, Nadezhda; Kydyrbayev, Zhailaubay; Assanzhanova, Nurika; Tabynov, Kairat; Renukaradhya, Gourapura J; Mukhitdinova, Gulnara; Sansyzbay, Abylai

    2016-12-25

    Previously we developed and evaluated a candidate influenza viral vector based Brucella abortus vaccine (Flu-BA) administered with a potent adjuvant Montanide Gel01 in cattle, which was found safe and highly effective. This study was aimed to establish a proof-of-concept of the efficacy of Flu-BA vaccine formulation in sheep and goats. We vaccinated sheep and goats with Flu-BA vaccine and as a positive control vaccinated a group of animals with a commercial B. melitensis Rev.1 vaccine. Clinically, both Flu-BA and Rev.1 vaccines were found safe. Serological analysis showed the animals received Flu-BA vaccine did not induce antibody response against Brucella Omp16 and L7/L12 proteins during the period of our study (56days post-initial vaccination, PIV). But observed significant antigen-specific T cell response indicated by increased lymphocyte stimulation index and enhanced secretion of IFN-γ at day 56 PIV in Flu-BA group. The Flu-BA vaccinated animals completely protected 57.1% of sheep and 42.9% of goats against B. melitensis 16M challenge. The severity of brucellosis in terms of infection index and colonization of Brucella in tissues was significantly lower in the Flu-BA group compared to negative control animals group. Nevertheless, positive control commercial Rev.1 vaccine provided strong antigen-specific T cell immunity and protection against B. melitensis 16M infection. We conclude that the Flu-BA vaccine induces a significant antigen-specific T-cell response and provides complete protection in approximately 50% of sheep and goats against B. melitensis 16M infection. Further investigations are needed to improve the efficacy of Flu-BA and explore its practical application in small ruminants.

  17. Vaccines

    MedlinePlus Videos and Cool Tools

    Vaccinations are injections of antigens into the body. Once the antigens enter the blood, they circulate along ... suppressor T cells stop the attack. After a vaccination, the body will have a memory of an ...

  18. A novel replication-competent vaccinia vector MVTT is superior to MVA for inducing high levels of neutralizing antibody via mucosal vaccination.

    PubMed

    Huang, Xiaoxing; Lu, Bin; Yu, Wenbo; Fang, Qing; Liu, Li; Zhuang, Ke; Shen, Tingting; Wang, Haibo; Tian, Po; Zhang, Linqi; Chen, Zhiwei

    2009-01-01

    Mucosal vaccination offers great advantage for inducing protective immune response to prevent viral transmission and dissemination. Here, we report our findings of a head-to-head comparison of two viral vectors modified vaccinia Ankara (MVA) and a novel replication-competent modified vaccinia Tian Tan (MVTT) for inducing neutralizing antibodies (Nabs) via intramuscular and mucosal vaccinations in mice. MVTT is an attenuated variant of the wild-type VTT, which was historically used as a smallpox vaccine for millions of Chinese people. The spike glycoprotein (S) of SARS-CoV was used as the test antigen after the S gene was constructed in the identical genomic location of two vectors to generate vaccine candidates MVTT-S and MVA-S. Using identical doses, MVTT-S induced lower levels ( approximately 2-3-fold) of anti- SARS-CoV neutralizing antibodies (Nabs) than MVA-S through intramuscular inoculation. MVTT-S, however, was capable of inducing consistently 20-to-100-fold higher levels of Nabs than MVA-S when inoculated via either intranasal or intraoral routes. These levels of MVTT-S-induced Nab responses were substantially (approximately 10-fold) higher than that induced via the intramuscular route in the same experiments. Moreover, pre-exposure to the wild-type VTT via intranasal or intraoral route impaired the Nab response via the same routes of MVTT-S vaccination probably due to the pre-existing anti-VTT Nab response. The efficacy of intranasal or intraoral vaccination, however, was still 20-to-50-fold better than intramuscular inoculation despite the subcutaneous pre-exposure to wild-type VTT. Our data have implications for people who maintain low levels of anti-VTT Nabs after historical smallpox vaccination. MVTT is therefore an attractive live viral vector for mucosal vaccination.

  19. Efficacy and safety of a live canine adenovirus-vectored rabies virus vaccine in swine.

    PubMed

    Liu, Ye; Zhang, Shoufeng; Ma, Guangpeng; Zhang, Fei; Hu, Rongliang

    2008-10-03

    Rabies infections in swine have been reported occasionally in recent years in certain geographic locations. Although a protective vaccine consisting of inactivated rabies virus is available for use in swine, searching for a more economically viable formulation for use in developing countries is always a priority. This work describes the testing of a canine adenovirus that expresses a rabies viral epitope (CAV-2-E3Delta-RGP) in a porcine rabies model. The data presented here show that the recombinant viral vaccine was effective in protecting swine against rabies if administered intramuscularly, but not orally or intranasally, and that protection was probably related to the development of a humoral response that lasted at least 28 weeks. Following vaccination, no behavioral abnormalities were observed in vaccinated swine and virus particles were not detected in either tissues or body fluids, indicating that this formulation was safe. The recombinant virus stimulated an effective level of antibody response in the immunized swine after a single intramuscular inoculation.

  20. Development of vaccines for poultry against H5 avian influenza based on turkey herpesvirus vector

    USDA-ARS?s Scientific Manuscript database

    Avian influenza (AI) remains a major threat to public health as well as to the poultry industry. AI vaccines are considered a suitable tool to support AI control programs in combination with other control measures such as good biosecurity and monitoring programs. We constructed recombinant turkey he...

  1. Intranasal Adenovirus-Vectored Vaccine for Induction of Long-Lasting Humoral Immunity-Mediated Broad Protection against Influenza in Mice

    PubMed Central

    Kim, Eun Hye; Park, Hae-Jung; Han, Gye-Yeong; Song, Man-Ki; Pereboev, Alexander; Hong, Jeong S.; Chang, Jun; Byun, Young-Ho; Seong, Baik Lin

    2014-01-01

    ABSTRACT Influenza vaccines aimed at inducing antibody (Ab) responses against viral surface hemagglutinin (HA) and neuraminidase (NA) provide sterile immunity to infection with the same subtypes. Vaccines targeting viral conserved determinants shared by the influenza A viruses (IAV) offer heterosubtypic immunity (HSI), a broad protection against different subtypes. We proposed that vaccines targeting both HA and the conserved ectodomain of matrix protein 2 (M2e) would provide protection against infection with the same subtype and also HSI against other subtypes. We report here that single intranasal immunization with a recombinant adenovirus (rAd) vector encoding both HA of H5 virus and M2e (rAdH5/M2e) induced significant HA- and M2e-specific Ab responses, along with protection against heterosubtypic challenge in mice. The protection is superior compared to that induced by rAd vector encoding either HA (rAdH5), or M2e (rAdM2e). While protection against homotypic H5 virus is primarily mediated by virus-neutralizing Abs, the cross-protection is associated with Abs directed to conserved stalk HA and M2e that seem to have an additive effect. Consistently, adoptive transfer of antisera induced by rAdH5/M2e provided the best protection against heterosubtypic challenge compared to that provided by antisera derived from mice immunized with rAdH5 or rAdM2e. These results support the development of rAd-vectored vaccines encoding both H5 and M2e as universal vaccines against different IAV subtypes. IMPORTANCE Current licensed influenza vaccines provide protection limited to the infection with same virus strains; therefore, the composition of influenza vaccines has to be revised every year. We have developed a new universal influenza vaccine that is highly efficient in induction of long-lasting cross-protection against different influenza virus strains. The cross-protection is associated with a high level of vaccine-induced antibodies against the conserved stalk domain of

  2. Have we found an optimal insertion site in a Newcastle disease virus vector to express a foreign gene for vaccine and gene therapy purposes?

    USDA-ARS?s Scientific Manuscript database

    Using reverse genetics technology, many strains of Newcastle disease virus (NDV) have been developed as vectors to express foreign genes for vaccine and gene therapy purposes. The foreign gene is usually inserted into a non-coding region of the NDV genome as an independent transcription unit. Eval...

  3. Expression of chicken parvovirus VP2 in chicken embryo fibroblasts requires codon optimization for production of naked DNA and vectored Meleagrid herpesvirus type 1 vaccines

    USDA-ARS?s Scientific Manuscript database

    Meleagrid herpesvirus type 1 (MeHV-1) is an ideal vector for the expression of antigens from pathogenic avian organisms in order to generate vaccines. Chicken parvovirus (ChPV) is a widespread infectious virus that causes serious disease in chickens. It is one of the etiological agents largely suspe...

  4. Adenovirus-vectored foot-and-mouth disease vaccine confers early and full protection against FMDV O1 Manisa in swine

    USDA-ARS?s Scientific Manuscript database

    A human adenovirus (Ad5) vectored foot-and-mouth disease virus (FMDV) sero-type O1-Manisa subunit vaccine (Ad5-O1Man) was engineered to deliver FMDV O1-Manisa empty capsids. Swine inoculated with Ad5-O1Man developed an FMDV-specific neutralizing antibody response as compared to animals inoculated wi...

  5. Oral immunization of mice against Clostridium perfringens epsilon toxin with a Lactobacillus casei vector vaccine expressing epsilon toxoid.

    PubMed

    Alimolaei, Mojtaba; Golchin, Mehdi; Daneshvar, Hamid

    2016-06-01

    Clostridium perfringens type D infects ruminants and causes the enterotoxemia disease by ε-toxin. A mutated ε-toxin gene lacking toxicity was designed, synthesized, and cloned into the pT1NX vector and electroporated into Lactobacillus casei competent cells to yield LC-pT1NX-ε recombinant strain. BALB/c mice, immunized orally with this strain, highly induced mucosal, humoral, and cell-mediated immune responses and developed a protection against 200 MLD/ml of the activated ε-toxin. This study showed that the LC-pT1NX-ε could be a promising vaccine candidate against the enterotoxemia disease. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. An alphavirus vector-based tetravalent dengue vaccine induces a rapid and protective immune response in macaques that differs qualitatively from immunity induced by live virus infection.

    PubMed

    White, Laura J; Sariol, Carlos A; Mattocks, Melissa D; Wahala M P B, Wahala; Yingsiwaphat, Vorraphun; Collier, Martha L; Whitley, Jill; Mikkelsen, Rochelle; Rodriguez, Idia V; Martinez, Melween I; de Silva, Aravinda; Johnston, Robert E

    2013-03-01

    Despite many years of research, a dengue vaccine is not available, and the more advanced live attenuated vaccine candidate in clinical trials requires multiple immunizations with long interdose periods and provides low protective efficacy. Here, we report important contributions to the development of a second-generation dengue vaccine. First, we demonstrate that a nonpropagating vaccine vector based on Venezuelan equine encephalitis virus replicon particles (VRP) expressing two configurations of dengue virus E antigen (subviral particles [prME] and soluble E dimers [E85]) successfully immunized and protected macaques against dengue virus, while antivector antibodies did not interfere with a booster immunization. Second, compared to prME-VRP, E85-VRP induced neutralizing antibodies faster, to higher titers, and with improved protective efficacy. Third, this study is the first to map antigenic domains and specificities targeted by vaccination versus natural infection, revealing that, unlike prME-VRP and live virus, E85-VRP induced only serotype-specific antibodies, which predominantly targeted EDIII, suggesting a protective mechanism different from that induced by live virus and possibly live attenuated vaccines. Fourth, a tetravalent E85-VRP dengue vaccine induced a simultaneous and protective response to all 4 serotypes after 2 doses given 6 weeks apart. Balanced responses and protection in macaques provided further support for exploring the immunogenicity and safety of this vaccine candidate in humans.

  7. Apple latent spherical virus vector as vaccine for the prevention and treatment of mosaic diseases in pea, broad bean, and eustoma plants by bean yellow mosaic virus.

    PubMed

    Satoh, Nozomi; Kon, Tatsuya; Yamagishi, Noriko; Takahashi, Tsubasa; Natsuaki, Tomohide; Yoshikawa, Nobuyuki

    2014-11-07

    We investigated the protective effects of a viral vector based on an Apple latent spherical virus (ALSV) harboring a segment of the Bean yellow mosaic virus (BYMV) genome against mosaic diseases in pea, broad bean, and eustoma plants caused by BYMV infection. In pea plants pre-inoculated with the ALSV vaccine and challenge inoculated with BYMV expressing green fluorescence protein, BYMV multiplication occurred in inoculated leaves, but was markedly inhibited in the upper leaves. No mosaic symptoms due to BYMV infection were observed in the challenged plants pre-inoculated with the ALSV vaccine. Simultaneous inoculation with the ALSV vaccine and BYMV also prevented mosaic symptoms in broad bean and eustoma plants, and BYMV accumulation was strongly inhibited in the upper leaves of plants treated with the ALSV vaccine. Pea and eustoma plants were pre-inoculated with BYMV followed by inoculation with the ALSV vaccine to investigate the curative effects of the ALSV vaccine. In both plant species, recovery from mosaic symptoms was observed in upper leaves and BYMV accumulation was inhibited in leaves developing post-ALSV vaccination. These results show that ALSV vaccination not only prevents mosaic diseases in pea, broad bean, and eustoma, but that it is also effective in curing these diseases.

  8. Apparent field safety of a raccoon poxvirus-vectored plague vaccine in free-ranging prairie dogs (Cynomys spp.), Colorado, USA.

    PubMed

    Tripp, Daniel W; Rocke, Tonie E; Streich, Sean P; Abbott, Rachel C; Osorio, Jorge E; Miller, Michael W

    2015-04-01

    Prairie dogs (Cynomys spp.) suffer high rates of mortality from plague. An oral sylvatic plague vaccine using the raccoon poxvirus vector (designated RCN-F1/V307) has been developed for prairie dogs. This vaccine is incorporated into palatable bait along with rhodamine B as a biomarker. We conducted trials in August and September 2012 to demonstrate uptake and apparent safety of the RCN-F1/V307 vaccine in two prairie dog species under field conditions. Free-ranging prairie dogs and other associated small rodents readily consumed vaccine-laden baits during field trials with no apparent adverse effects; most sampled prairie dogs (90%) and associated small rodents (78%) had consumed baits. Visual counts of prairie dogs and their burrows revealed no evidence of prairie dog decline after vaccine exposure. No vaccine-related morbidity, mortality, or gross or microscopic lesions were observed. Poxviruses were not isolated from any animal sampled prior to bait distribution or on sites that received placebo baits. We isolated RCN-F1/V307 from 17 prairie dogs and two deer mice (Peromyscus maniculatus) captured on sites where vaccine-laden baits were distributed. Based on these findings, studies examining the utility and effectiveness of oral vaccination to prevent plague-induced mortality in prairie dogs and associated species are underway.

  9. Apple Latent Spherical Virus Vector as Vaccine for the Prevention and Treatment of Mosaic Diseases in Pea, Broad Bean, and Eustoma Plants by Bean Yellow Mosaic Virus

    PubMed Central

    Satoh, Nozomi; Kon, Tatsuya; Yamagishi, Noriko; Takahashi, Tsubasa; Natsuaki, Tomohide; Yoshikawa, Nobuyuki

    2014-01-01

    We investigated the protective effects of a viral vector based on an Apple latent spherical virus (ALSV) harboring a segment of the Bean yellow mosaic virus (BYMV) genome against mosaic diseases in pea, broad bean, and eustoma plants caused by BYMV infection. In pea plants pre-inoculated with the ALSV vaccine and challenge inoculated with BYMV expressing green fluorescence protein, BYMV multiplication occurred in inoculated leaves, but was markedly inhibited in the upper leaves. No mosaic symptoms due to BYMV infection were observed in the challenged plants pre-inoculated with the ALSV vaccine. Simultaneous inoculation with the ALSV vaccine and BYMV also prevented mosaic symptoms in broad bean and eustoma plants, and BYMV accumulation was strongly inhibited in the upper leaves of plants treated with the ALSV vaccine. Pea and eustoma plants were pre-inoculated with BYMV followed by inoculation with the ALSV vaccine to investigate the curative effects of the ALSV vaccine. In both plant species, recovery from mosaic symptoms was observed in upper leaves and BYMV accumulation was inhibited in leaves developing post-ALSV vaccination. These results show that ALSV vaccination not only prevents mosaic diseases in pea, broad bean, and eustoma, but that it is also effective in curing these diseases. PMID:25386843

  10. An Alphavirus Vector-Based Tetravalent Dengue Vaccine Induces a Rapid and Protective Immune Response in Macaques That Differs Qualitatively from Immunity Induced by Live Virus Infection

    PubMed Central

    Sariol, Carlos A.; Mattocks, Melissa D.; Wahala M. P. B., Wahala; Yingsiwaphat, Vorraphun; Collier, Martha L.; Whitley, Jill; Mikkelsen, Rochelle; Rodriguez, Idia V.; Martinez, Melween I.; de Silva, Aravinda; Johnston, Robert E.

    2013-01-01

    Despite many years of research, a dengue vaccine is not available, and the more advanced live attenuated vaccine candidate in clinical trials requires multiple immunizations with long interdose periods and provides low protective efficacy. Here, we report important contributions to the development of a second-generation dengue vaccine. First, we demonstrate that a nonpropagating vaccine vector based on Venezuelan equine encephalitis virus replicon particles (VRP) expressing two configurations of dengue virus E antigen (subviral particles [prME] and soluble E dimers [E85]) successfully immunized and protected macaques against dengue virus, while antivector antibodies did not interfere with a booster immunization. Second, compared to prME-VRP, E85-VRP induced neutralizing antibodies faster, to higher titers, and with improved protective efficacy. Third, this study is the first to map antigenic domains and specificities targeted by vaccination versus natural infection, revealing that, unlike prME-VRP and live virus, E85-VRP induced only serotype-specific antibodies, which predominantly targeted EDIII, suggesting a protective mechanism different from that induced by live virus and possibly live attenuated vaccines. Fourth, a tetravalent E85-VRP dengue vaccine induced a simultaneous and protective response to all 4 serotypes after 2 doses given 6 weeks apart. Balanced responses and protection in macaques provided further support for exploring the immunogenicity and safety of this vaccine candidate in humans. PMID:23302884

  11. Eimeria species parasites as novel vaccine delivery vectors: anti-Campylobacter jejuni protective immunity induced by Eimeria tenella-delivered CjaA.

    PubMed

    Clark, Julie D; Oakes, Richard D; Redhead, Keith; Crouch, Colin F; Francis, Michael J; Tomley, Fiona M; Blake, Damer P

    2012-03-30

    Vaccination of poultry against coccidiosis caused by the Eimeria species is almost entirely based upon varied formulations of live parasites. The recent development of a series of protocols that support genetic complementation by transfection in Eimeria now provides an opportunity to utilise live anticoccidial vaccines to deliver additional vaccinal antigens. The capacity of Eimeria tenella to express an exogenous antigen and induce an immune response during in vivo infection which is protective against subsequent bacterial challenge has been tested here using the anti-Campylobacter jejuni vaccine candidate CjaA. Using restriction enzyme mediated integration (REMI) a transgenic E. tenella population expressing CjaA and the fluorescent reporter mCitrine has been developed. Vaccination of specific pathogen free chickens by single or multiple oral inoculation of E. tenella-CjaA oocysts induced 91% and 86% immune protection against C. jejuni challenge compared with unvaccinated and wild-type E. tenella vaccinated controls (p<0.001). Increasing vaccination number had no significant influence on the magnitude of protection. These results support the hypothesis that eimerian parasites can be developed as multivalent vaccine vectors and encourage the extension of these studies.

  12. Apparent field safety of a raccoon poxvirus-vectored plague vaccine in free-ranging prairie dogs (Cynomys spp.), Colorado, USA

    USGS Publications Warehouse

    Tripp, Daniel W.; Rocke, Tonie E.; Streich, Sean P.; Abbott, Rachel C.; Osorio, Jorge E.; Miller, Michael W.

    2015-01-01

    Prairie dogs (Cynomys spp.) suffer high rates of mortality from plague. An oral sylvatic plague vaccine using the raccoon poxvirus vector (designated RCN-F1/V307) has been developed for prairie dogs. This vaccine is incorporated into palatable bait along with rhodamine B as a biomarker. We conducted trials in August and September 2012 to demonstrate uptake and apparent safety of the RCN-F1/V307 vaccine in two prairie dog species under field conditions. Free-ranging prairie dogs and other associated small rodents readily consumed vaccine-laden baits during field trials with no apparent adverse effects; most sampled prairie dogs (90%) and associated small rodents (78%) had consumed baits. Visual counts of prairie dogs and their burrows revealed no evidence of prairie dog decline after vaccine exposure. No vaccine-related morbidity, mortality, or gross or microscopic lesions were observed. Poxviruses were not isolated from any animal sampled prior to bait distribution or on sites that received placebo baits. We isolated RCN-F1/V307 from 17 prairie dogs and two deer mice (Peromyscus maniculatus) captured on sites where vaccine-laden baits were distributed. Based on these findings, studies examining the utility and effectiveness of oral vaccination to prevent plague-induced mortality in prairie dogs and associated species are underway.

  13. Intratumoral delivery of vector mediated IL-2 in combination with vaccine results in enhanced T cell avidity and anti-tumor activity.

    PubMed

    Kudo-Saito, Chie; Garnett, Charlie T; Wansley, Elizabeth K; Schlom, Jeffrey; Hodge, James W

    2007-12-01

    Systemic IL-2 is currently employed in the therapy of several tumor types, but at the price of often severe toxicities. Local vector mediated delivery of IL-2 at the tumor site may enhance local effector cell activity while reducing toxicity. To examine this, a model using CEA-transgenic mice bearing established CEA expressing tumors was employed. The vaccine regimen was a s.c. prime vaccination with recombinant vaccinia (rV) expressing transgenes for CEA and a triad of costimulatory molecules (TRICOM) followed by i.t. boosting with rF-CEA/TRICOM. The addition of intratumoral (i.t.) delivery of IL-2 via a recombinant fowlpox (rF) IL-2 vector greatly enhanced anti-tumor activity of a recombinant vaccine, resulting in complete tumor regression in 70-80% of mice. The anti-tumor activity was shown to be dependent on CD8(+) cells and NK1.1(+). Cellular immune assays revealed that the addition of rF-IL-2 to the vaccination therapy enhanced CEA-specific tetramer(+) cell numbers, cytokine release and CTL lysis of CEA(+) targets. Moreover, tumor-bearing mice vaccinated with the CEA/TRICOM displayed an antigen cascade, i.e., CD8(+) T cell responses to two other antigens expressed on the tumor and not the vaccine: wild-type p53 and endogenous retroviral antigen gp70. Mice receiving rF-IL-2 during vaccination demonstrated higher avidity CEA-specific, as well as higher avidity gp70-specific, CD8(+) T cells when compared with mice vaccinated without rF-IL-2. These studies demonstrate for the first time that the level and avidity of antigen specific CTL, as well as the therapeutic outcome can be improved with the use of i.t. rF-IL-2 with vaccine regimens.

  14. In Vivo Characterization of the Murine Intranasal Model for Assessing the Immunogenicity of Attenuated Salmonella enterica Serovar Typhi Strains as Live Mucosal Vaccines and as Live Vectors

    PubMed Central

    Pickett, Thames E.; Pasetti, Marcela F.; Galen, James E.; Sztein, Marcelo B.; Levine, Myron M.

    2000-01-01

    Attenuated Salmonella enterica serovar Typhi live vector vaccine strains are highly immunogenic in mice following intranasal but not orogastric inoculation. To elucidate the relationship between organs within which vaccine organisms are found and the induction of specific serum immunoglobulin G (IgG) antibodies, we examined the in vivo distribution of serovar Typhi vaccine strain CVD 908-htrA following intranasal administration. Vaccine organisms were cultured from the nasal lymphoid tissue (NALT), lungs, and Peyer's patches 2 min after intranasal inoculation. Vaccine organisms persisted longer in NALT than in other organs. By decreasing the volume of intranasal inoculum containing 109 CFU (from a single 30- or 10-μl dose to four 2.5-μl doses given over the course of 1 h), we were able to significantly reduce the number of vaccine organisms isolated from the lungs (P < 0.05) without reducing the number of vaccine organisms in NALT. Reducing the number of vaccine organisms in the lungs resulted in a significant decrease in the serum tetanus antitoxin response elicited by CVD 908-htrA expressing tetanus toxin fragment C under the control of the redox-responsive nir15 promoter. In contrast, a similar construct expressing tetanus toxin fragment C under control of the constitutive lpp promoter stimulated a strong serum IgG tetanus antitoxin response with both inoculation regimens. The data suggest that following intranasal inoculation, NALT is a sufficient inductive site for elicitation of an immune response against both the live vector and heterologous antigen and, as occurs following oral inoculation of humans, attenuated serovar Typhi vaccine organisms elicit serum IgG responses. PMID:10603389

  15. Protective efficacy of a single immunization with capripoxvirus-vectored recombinant peste des petits ruminants vaccines in presence of pre-existing immunity.

    PubMed

    Caufour, Philippe; Rufael, Tesfaye; Lamien, Charles Euloge; Lancelot, Renaud; Kidane, Menbere; Awel, Dino; Sertse, Tefera; Kwiatek, Olivier; Libeau, Geneviève; Sahle, Mesfin; Diallo, Adama; Albina, Emmanuel

    2014-06-24

    Sheeppox, goatpox and peste des petits ruminants (PPR) are highly contagious ruminant diseases widely distributed in Africa, the Middle East and Asia. Capripoxvirus (CPV)-vectored recombinant PPR vaccines (rCPV-PPR vaccines), which have been developed and shown to protect against both Capripox (CP) and PPR, would be critical tools in the control of these important diseases. In most parts of the world, these disease distributions overlap each other leaving concerns about the potential impact that pre-existing immunity against either disease may have on the protective efficacy of these bivalent rCPV-PPR vaccines. Currently, this question has not been indisputably addressed. Therefore, we undertook this study, under experimental conditions designed for the context of mass vaccination campaigns of small ruminants, using the two CPV recombinants (Kenya sheep-1 (KS-1) strain-based constructs) developed previously in our laboratory. Pre-existing immunity was first induced by immunization either with an attenuated CPV vaccine strain (KS-1) or the attenuated PPRV vaccine strain (Nigeria 75/1) and animals were thereafter inoculated once subcutaneously with a mixture of CPV recombinants expressing either the hemagglutinin (H) or the fusion (F) protein gene of PPRV (10(3) TCID50/animal of each). Finally, these animals were challenged with a virulent CPV strain followed by a virulent PPRV strain 3 weeks later. Our study demonstrated full protection against CP for vaccinated animals with prior exposure to PPRV and a partial protection against PPR for vaccinated animals with prior exposure to CPV. The latter animals exhibited a mild clinical form of PPR and did not show any post-challenge anamnestic neutralizing antibody response against PPRV. The implications of these results are discussed herein and suggestions made for future research regarding the development of CPV-vectored vaccines. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Properties of a herpes simplex virus multiple immediate-early gene-deleted recombinant as a vaccine vector

    SciTech Connect

    Watanabe, Daisuke; Brockman, Mark A.; Ndung'u, Thumbi; Mathews, Lydia; Lucas, William T.; Murphy, Cynthia G.; Felber, Barbara K.; Pavlakis, George N.; Deluca, Neal A.; Knipe, David M. . E-mail: david_knipe@hms.harvard.edu

    2007-01-20

    Herpes simplex virus (HSV) recombinants induce durable immune responses in rhesus macaques and mice and have induced partial protection in rhesus macaques against mucosal challenge with virulent simian immunodeficiency virus (SIV). In this study, we evaluated the properties of a new generation HSV vaccine vector, an HSV-1 multiple immediate-early (IE) gene deletion mutant virus, d106, which contains deletions in the ICP4, ICP27, ICP22, and ICP47 genes. Because several of the HSV IE genes have been implicated in immune evasion, inactivation of the genes encoding these proteins was expected to result in enhanced immunogenicity. The d106 virus expresses few HSV gene products and shows minimal cytopathic effect in cultured cells. When d106 was inoculated into mice, viral DNA accumulated at high levels in draining lymph nodes, consistent with an ability to transduce dendritic cells and activate their maturation and movement to lymph nodes. A d106 recombinant expressing Escherichia coli {beta}-galactosidase induced durable {beta}-gal-specific IgG and CD8{sup +} T cell responses in naive and HSV-immune mice. Finally, d106-based recombinants have been constructed that express simian immunodeficiency virus (SIV) gag, env, or a rev-tat-nef fusion protein for several days in cultured cells. Thus, d106 shows many of the properties desirable in a vaccine vector: limited expression of HSV gene products and cytopathogenicity, high level expression of transgenes, ability to induce durable immune responses, and an ability to transduce dendritic cells and induce their maturation and migration to lymph nodes.

  17. Induction of CD8(+) T cell responses and protective efficacy following microneedle-mediated delivery of a live adenovirus-vectored malaria vaccine.

    PubMed

    Pearson, Frances E; O'Mahony, Conor; Moore, Anne C; Hill, Adrian V S

    2015-06-22

    There is an urgent need for improvements in vaccine delivery technologies. This is particularly pertinent for vaccination programmes within regions of limited resources, such as those required for adequate provision for disposal of used needles. Microneedles are micron-sized structures that penetrate the stratum corneum of the skin, creating temporary conduits for the needle-free delivery of drugs or vaccines. Here, we aimed to investigate immunity induced by the recombinant simian adenovirus-vectored vaccine ChAd63.ME-TRAP; currently undergoing clinical assessment as a candidate malaria vaccine, when delivered percutaneously by silicon microneedle arrays. In mice, we demonstrate that microneedle-mediated delivery of ChAd63.ME-TRAP induced similar numbers of transgene-specific CD8(+) T cells compared to intradermal (ID) administration with needle-and-syringe, following a single immunisation and after a ChAd63/MVA heterologous prime-boost schedule. When mice immunised with ChAd63/MVA were challenged with live Plasmodium berghei sporozoites, microneedle-mediated ChAd63.ME-TRAP priming demonstrated equivalent protective efficacy as did ID immunisation. Furthermore, responses following ChAd63/MVA immunisation correlated with a specific design parameter of the array used ('total array volume'). The level of transgene expression at the immunisation site and skin-draining lymph node (dLN) was also linked to total array volume. These findings have implications for defining silicon microneedle array design for use with live, vectored vaccines.

  18. Combining viral vectored and protein-in-adjuvant vaccines against the blood-stage malaria antigen AMA1: report on a phase 1a clinical trial.

    PubMed

    Hodgson, Susanne H; Choudhary, Prateek; Elias, Sean C; Milne, Kathryn H; Rampling, Thomas W; Biswas, Sumi; Poulton, Ian D; Miura, Kazutoyo; Douglas, Alexander D; Alanine, Daniel Gw; Illingworth, Joseph J; de Cassan, Simone C; Zhu, Daming; Nicosia, Alfredo; Long, Carole A; Moyle, Sarah; Berrie, Eleanor; Lawrie, Alison M; Wu, Yimin; Ellis, Ruth D; Hill, Adrian V S; Draper, Simon J

    2014-12-01

    The development of effective vaccines against difficult disease targets will require the identification of new subunit vaccination strategies that can induce and maintain effective immune responses in humans. Here we report on a phase 1a clinical trial using the AMA1 antigen from the blood-stage Plasmodium falciparum malaria parasite delivered either as recombinant protein formulated with Alhydrogel adjuvant with and without CPG 7909, or using recombinant vectored vaccines--chimpanzee adenovirus ChAd63 and the orthopoxvirus MVA. A variety of promising "mixed-modality" regimens were tested. All volunteers were primed with ChAd63, and then subsequently boosted with MVA and/or protein-in-adjuvant using either an 8- or 16-week prime-boost interval. We report on the safety of these regimens, as well as the T cell, B cell, and serum antibody responses. Notably, IgG antibody responses primed by ChAd63 were comparably boosted by AMA1 protein vaccine, irrespective of whether CPG 7909 was included in the Alhydrogel adjuvant. The ability to improve the potency of a relatively weak aluminium-based adjuvant in humans, by previously priming with an adenoviral vaccine vector encoding the same antigen, thus offers a novel vaccination strategy for difficult or neglected disease targets when access to more potent adjuvants is not possible.

  19. Poly ICLC increases the potency of a replication-defective human adenovirus vectored foot-and-mouth disease vaccine.

    PubMed

    Diaz-San Segundo, Fayna; Dias, Camila C; Moraes, Mauro P; Weiss, Marcelo; Perez-Martin, Eva; Salazar, Andres M; Grubman, Marvin J; de los Santos, Teresa

    2014-11-01

    Foot-and-mouth disease virus (FMDV) causes a highly contagious disease of cloven-hoofed animals. We have previously demonstrated that a replication-defective human adenovirus 5 vector carrying the FMDV capsid coding region of serotype A24 Cruzeiro (Ad5-CI-A24-2B) protects swine and cattle against FMDV challenge by 7 days post-vaccination. However, since relatively large amounts of Ad5-CI-A24-2B are required to induce protection this strategy could be costly for livestock production. Poly ICLC is a synthetic double stranded RNA that activates multiple innate and adaptive immune pathways. In this study, we have tested for the first time, the adjuvant effect of poly ICLC in combination with Ad5-CI-A24-2B in swine. We found that the combination resulted in a reduction of the vaccine protective dose by 80-fold. Interestingly, the lowest dose of Ad5-CI-A24-2B plus 1mg of poly ICLC protected animals against challenge even in the absence of detectable FMDV-specific neutralizing antibodies at the time of challenge.

  20. Nonintegrating Lentiviral Vector-Based Vaccine Efficiently Induces Functional and Persistent CD8+ T Cell Responses in Mice

    PubMed Central

    Negri, Donatella R. M.; Michelini, Zuleika; Baroncelli, Silvia; Spada, Massimo; Vendetti, Silvia; Bona, Roberta; Leone, Pasqualina; Klotman, Mary E.; Cara, Andrea

    2010-01-01

    CD8+ T cells are an essential component of an effective host immune response to tumors and viral infections. Genetic immunization is particularly suitable for inducing CTL responses, because the encoded proteins enter the MHC class I processing pathway through either transgene expression or cross-presentation. In order to compare the efficiency and persistence of immune response induced by genetic vaccines, BALB/c mice were immunized either twice intramuscularly with DNA plasmid expressing a codon-optimized HIV-1 gp120 Envelope sequence together with murine GM-CSF sequence or with a single immunization using an integrase defective lentiviral vector (IDLV) expressing the same proteins. Results strongly indicated that the schedule based on IDLV vaccine was more efficient in inducing specific immune response, as evaluated three months after the last immunization by IFNγ ELISPOT in both splenocytes and bone marrow- (BM-) derived cells, chromium release assay in splenocytes, and antibody detection in sera. In addition, IDLV immunization induced high frequency of polyfunctional CD8+ T cells able to simultaneously produce IFNγ, TNFα, and IL2. PMID:20508727

  1. Viral Vector Malaria Vaccines Induce High-Level T Cell and Antibody Responses in West African Children and Infants.

    PubMed

    Bliss, Carly M; Drammeh, Abdoulie; Bowyer, Georgina; Sanou, Guillaume S; Jagne, Ya Jankey; Ouedraogo, Oumarou; Edwards, Nick J; Tarama, Casimir; Ouedraogo, Nicolas; Ouedraogo, Mireille; Njie-Jobe, Jainaba; Diarra, Amidou; Afolabi, Muhammed O; Tiono, Alfred B; Yaro, Jean Baptiste; Adetifa, Uche J; Hodgson, Susanne H; Anagnostou, Nicholas A; Roberts, Rachel; Duncan, Christopher J A; Cortese, Riccardo; Viebig, Nicola K; Leroy, Odile; Lawrie, Alison M; Flanagan, Katie L; Kampmann, Beate; Imoukhuede, Egeruan B; Sirima, Sodiomon B; Bojang, Kalifa; Hill, Adrian V S; Nébié, Issa; Ewer, Katie J

    2017-02-01

    Heterologous prime-boosting with viral vectors encoding the pre-erythrocytic antigen thrombospondin-related adhesion protein fused to a multiple epitope string (ME-TRAP) induces CD8(+) T cell-mediated immunity to malaria sporozoite challenge in European malaria-naive and Kenyan semi-immune adults. This approach has yet to be evaluated in children and infants. We assessed this vaccine strategy among 138 Gambian and Burkinabe children in four cohorts: 2- to 6-year olds in The Gambia, 5- to 17-month-olds in Burkina Faso, and 5- to 12-month-olds and 10-week-olds in The Gambia. We assessed induction of cellular immunity, taking into account the distinctive hematological status of young infants, and characterized the antibody response to vaccination. T cell responses peaked 7 days after boosting with modified vaccinia virus Ankara (MVA), with highest responses in infants aged 10 weeks at priming. Incorporating lymphocyte count into the calculation of T cell responses facilitated a more physiologically relevant comparison of cellular immunity across different age groups. Both CD8(+) and CD4(+) T cells secreted cytokines. Induced antibodies were up to 20-fold higher in all groups compared with Gambian and United Kingdom (UK) adults, with comparable or higher avidity. This immunization regimen elicited strong immune responses, particularly in young infants, supporting future evaluation of efficacy in this key target age group for a malaria vaccine. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  2. Murine polyomavirus virus-like particles (VLPs) as vectors for gene and immune therapy and vaccines against viral infections and cancer.

    PubMed

    Tegerstedt, Karin; Franzén, Andrea Vlastos; Andreasson, Kalle; Joneberg, Jeanna; Heidari, Shirin; Ramqvist, Torbjörn; Dalianis, Tina

    2005-01-01

    This review describes the use of murine polyomavirus "virus-like" particles (MPyV-VLPs), free from viral genes, as vectors for gene and immune therapy and as vaccines. For large-scale MPyV-VLP manufacture, VP1 is produced in a baculovirus insect cell system, E. coli or in yeast. MPyV-VLPs bind eukaryotic DNA and introduce this DNA into various cell types in vitro and in vivo. In normal and T-cell-deficient mice, this results in the production of anti-MPyV-VLP (and MPyV) antibodies. Furthermore, repeated MPyV-VLP vaccination has been shown to prevent primary MPyV infection in normal and T-cell-deficient mice, and the outgrowth of some MPyV-induced tumours in normal mice. Moreover, when inoculated with gene constructs encoding for HIV p24, MPyV-VLPs augment the antibody response to p24. In addition, MPyV-VLPs, containing fusion proteins between the VP2 or VP3 capsid protein and selected antigens, can be used as vaccines. Notably, one vaccination with MPyV-VLPs, containing a fusion protein between VP2 and the extracellular and transmembrane parts of the HER-2/neu oncogene, immunizes against outgrowth of a HER-2/neu-expressing tumour in Balb/c mice and also against the development of mammary carcinomas in BALB-neuT transgenic mice. Finally, a second polyoma VLP-vector based on murine pneumotropic virus (MPtV-VLP), which does not cross-react serologically with MPyV-VLP (and MPyV), has been developed and can be used to conduct prime boost gene and immune therapy and vaccination. In summary, MPyV-VLPs are useful vectors for gene therapy, immune therapy and as vaccines and, in combination with MPyV-VLPs, MPtV-VLPs are potentially useful as prime-boost vectors.

  3. Potent immune responses and in vitro pro-inflammatory cytokine suppression by a novel adenovirus vaccine vector based on rare human serotype 28

    PubMed Central

    Kahl, Christoph A.; Bonnell, Jessica; Hiriyanna, Suja; Fultz, Megan; Nyberg-Hoffman, Cassandra; Chen, Ping; King, C. Richter; Gall, Jason G. D.

    2010-01-01

    Adenovirus vaccine vectors derived from rare human serotypes have been shown to be less potent than serotype 5 (Ad5) at inducing immune responses to encoded antigens. To identify highly immunogenic adenovirus vectors, we assessed pro-inflammatory cytokine expression, binding to the CD46 receptor, and immunogenicity. Species D adenoviruses uniquely suppressed pro-inflammatory cytokines and induced high levels of type I interferon. Thus, it was unexpected that a vector derived from a representative serotype, Ad28, induced significantly higher transgene-specific T-cell responses than an Ad35 vector. Prime-boost regimens with Ad28, Ad35, Ad14, or Ad5 significantly boosted T cell and antibody responses. The seroprevalence of Ad28 was confirmed to be <10% in the United States. Together, this shows that a rare human serotype-based vector can elicit strong immune responses, which was not predicted by in vitro results. PMID:20600496

  4. Potent immune responses and in vitro pro-inflammatory cytokine suppression by a novel adenovirus vaccine vector based on rare human serotype 28.

    PubMed

    Kahl, Christoph A; Bonnell, Jessica; Hiriyanna, Suja; Fultz, Megan; Nyberg-Hoffman, Cassandra; Chen, Ping; King, C Richter; Gall, Jason G D

    2010-08-09

    Adenovirus vaccine vectors derived from rare human serotypes have been shown to be less potent than serotype 5 (Ad5) at inducing immune responses to encoded antigens. To identify highly immunogenic adenovirus vectors, we assessed pro-inflammatory cytokine expression, binding to the CD46 receptor, and immunogenicity. Species D adenoviruses uniquely suppressed pro-inflammatory cytokines and induced high levels of type I interferon. Thus, it was unexpected that a vector derived from a representative serotype, Ad28, induced significantly higher transgene-specific T cell responses than an Ad35 vector. Prime-boost regimens with Ad28, Ad35, Ad14, or Ad5 significantly boosted T cell and antibody responses. The seroprevalence of Ad28 was confirmed to be <10% in the United States. Together, this shows that a rare human serotype-based vector can elicit strong immune responses, which was not predicted by in vitro results.

  5. Lactic acid bacteria--20 years exploring their potential as live vectors for mucosal vaccination.

    PubMed

    Wyszyńska, Agnieszka; Kobierecka, Patrycja; Bardowski, Jacek; Jagusztyn-Krynicka, Elżbieta Katarzyna

    2015-04-01

    Lactic acid bacteria (LAB) are a diverse group of Gram-positive, nonsporulating, low G + C content bacteria. Many of them have been given generally regarded as safe status. Over the past two decades, intensive genetic and molecular research carried out on LAB, mainly Lactococcus lactis and some species of the Lactobacillus genus, has revealed new, potential biomedical LAB applications, including the use of LAB as adjuvants, immunostimulators, or therapeutic drug delivery systems, or as factories to produce therapeutic molecules. LAB enable immunization via the mucosal route, which increases effectiveness against pathogens that use the mucosa as the major route of entry into the human body. In this review, we concentrate on the encouraging application of Lactococcus and Lactobacillus genera for the development of live mucosal vaccines. First, we present the progress that has recently been made in the field of developing tools for LAB genetic manipulations, which has resulted in the successful expression of many bacterial, parasitic, and viral antigens in LAB strains. Next, we discuss the factors influencing the efficacy of the constructed vaccine prototypes that have been tested in various animal models. Apart from the research focused on an application of live LABs as carriers of foreign antigens, a lot of work has been recently done on the potential usage of nonliving, nonrecombinant L. lactis designated as Gram-positive enhancer matrix (GEM), as a delivery system for mucosal vaccination. The advantages and disadvantages of both strategies are also presented.

  6. Newcastle disease virus-vectored West Nile fever vaccine is immunogenic in mammals and poultry.

    PubMed

    Wang, Jinliang; Yang, Jie; Ge, Jinying; Hua, Ronghong; Liu, Renqiang; Li, Xiaofeng; Wang, Xijun; Shao, Yu; Sun, Encheng; Wu, Donglai; Qin, Chengfeng; Wen, Zhiyuan; Bu, Zhigao

    2016-06-24

    West Nile virus (WNV) is an emerging zoonotic pathogen which is harmful to human and animal health. Effective vaccination in susceptible hosts should protect against WNV infection and significantly reduce viral transmission between animals and from animals to humans. A versatile vaccine suitable for different species that can be delivered via flexible routes remains an essential unmet medical need. In this study, we developed a recombinant avirulent Newcastle disease virus (NDV) LaSota strain expressing WNV premembrane/envelope (PrM/E) proteins (designated rLa-WNV-PrM/E) and evaluated its immunogenicity in mice, horses, chickens, ducks and geese. Mouse immunization experiments disclosed that rLa-WNV-PrM/E induces significant levels of WNV-neutralizing antibodies and E protein-specific CD4+ and CD8+ T-cell responses. Moreover, recombinant rLa-WNV-PrM/E elicited significant levels of WNV-specific IgG in horses upon delivery via intramuscular immunization, and in chickens, ducks and geese via intramuscular, oral or intranasal immunization. Our results collectively support the utility of rLa-WNV-PrM/E as a promising WNV veterinary vaccine candidate for mammals and poultry.

  7. Lactobacillus plantarum vaccine vector expressing hemagglutinin provides protection against H9N2 challenge infection.

    PubMed

    Shi, Shao-Hua; Yang, Wen-Tao; Yang, Gui-Lian; Zhang, Xu-Ke; Liu, Yu-Ying; Zhang, Li-Jiao; Ye, Li-Ping; Hu, Jing-Tao; Xing, Xin; Qi, Chong; Li, Yu; Wang, Chun-Feng

    2016-01-04

    Hemagglutinin (HA) has been demonstrated as an effective candidate vaccine antigen against AIVs. Dendritic cell-targeting peptide (DCpep) can enhance the robustness of immune responses. The purpose of this study was to evaluate whether DCpep could enhance the immune response against H9N2 AIV when utilizing Lactobacillus plantarum NC8 (NC8) to present HA-DCpep in mouse and chicken models. To accomplish this, a mucosal vaccine of a recombinant NC8 strain expressing HA and DCpep that was constructed in a previous study was employed. Orally administered NC8-pSIP409-HA-DCpep elicited high serum titers of hemagglutination-inhibition (HI) antibodies in mice and also induced robust T cell immune responses in both mouse and chicken models. Orally administered NC8-pSIP409-HA-DCpep elicited high serum titers of hemagglutination-inhibition (HI) antibodies in mice and also induced robust T cell immune responses in both mouse and chicken models. These results revealed that recombinant L. plantarum NC8-pSIP409-HA-DCpep is an effective vaccine candidate against H9N2 AIVs.

  8. Dry-Coated Live Viral Vector Vaccines Delivered by Nanopatch Microprojections Retain Long-Term Thermostability and Induce Transgene-Specific T Cell Responses in Mice

    PubMed Central

    Pearson, Frances E.; McNeilly, Celia L.; Crichton, Michael L.; Primiero, Clare A.; Yukiko, Sally R.; Fernando, Germain J. P.; Chen, Xianfeng; Gilbert, Sarah C.; Hill, Adrian V. S.; Kendall, Mark A. F.

    2013-01-01

    The disadvantages of needle-based immunisation motivate the development of simple, low cost, needle-free alternatives. Vaccine delivery to cutaneous environments rich in specialised antigen-presenting cells using microprojection patches has practical and immunological advantages over conventional needle delivery. Additionally, stable coating of vaccine onto microprojections removes logistical obstacles presented by the strict requirement for cold-chain storage and distribution of liquid vaccine, or lyophilised vaccine plus diluent. These attributes make these technologies particularly suitable for delivery of vaccines against diseases such as malaria, which exerts its worst effects in countries with poorly-resourced healthcare systems. Live viral vectors including adenoviruses and poxviruses encoding exogenous antigens have shown significant clinical promise as vaccines, due to their ability to generate high numbers of antigen-specific T cells. Here, the simian adenovirus serotype 63 and the poxvirus modified vaccinia Ankara – two vectors under evaluation for the delivery of malaria antigens to humans – were formulated for coating onto Nanopatch microprojections and applied to murine skin. Co-formulation with the stabilising disaccharides trehalose and sucrose protected virions during the dry-coating process. Transgene-specific CD8+ T cell responses following Nanopatch delivery of both vectors were similar to intradermal injection controls after a single immunisation (despite a much lower delivered dose), though MVA boosting of pre-primed responses with Nanopatch was found to be less effective than the ID route. Importantly, disaccharide-stabilised ChAd63 could be stored for 10 weeks at 37°C with less than 1 log10 loss of viability, and retained single-dose immunogenicity after storage. These data support the further development of microprojection patches for the deployment of live vaccines in hot climates. PMID:23874462

  9. Dry-coated live viral vector vaccines delivered by nanopatch microprojections retain long-term thermostability and induce transgene-specific T cell responses in mice.

    PubMed

    Pearson, Frances E; McNeilly, Celia L; Crichton, Michael L; Primiero, Clare A; Yukiko, Sally R; Fernando, Germain J P; Chen, Xianfeng; Gilbert, Sarah C; Hill, Adrian V S; Kendall, Mark A F

    2013-01-01

    The disadvantages of needle-based immunisation motivate the development of simple, low cost, needle-free alternatives. Vaccine delivery to cutaneous environments rich in specialised antigen-presenting cells using microprojection patches has practical and immunological advantages over conventional needle delivery. Additionally, stable coating of vaccine onto microprojections removes logistical obstacles presented by the strict requirement for cold-chain storage and distribution of liquid vaccine, or lyophilised vaccine plus diluent. These attributes make these technologies particularly suitable for delivery of vaccines against diseases such as malaria, which exerts its worst effects in countries with poorly-resourced healthcare systems. Live viral vectors including adenoviruses and poxviruses encoding exogenous antigens have shown significant clinical promise as vaccines, due to their ability to generate high numbers of antigen-specific T cells. Here, the simian adenovirus serotype 63 and the poxvirus modified vaccinia Ankara--two vectors under evaluation for the delivery of malaria antigens to humans--were formulated for coating onto Nanopatch microprojections and applied to murine skin. Co-formulation with the stabilising disaccharides trehalose and sucrose protected virions during the dry-coating process. Transgene-specific CD8(+) T cell responses following Nanopatch delivery of both vectors were similar to intradermal injection controls after a single immunisation (despite a much lower delivered dose), though MVA boosting of pre-primed responses with Nanopatch was found to be less effective than the ID route. Importantly, disaccharide-stabilised ChAd63 could be stored for 10 weeks at 37°C with less than 1 log10 loss of viability, and retained single-dose immunogenicity after storage. These data support the further development of microprojection patches for the deployment of live vaccines in hot climates.

  10. Transfected babesia bovis expressing a tick GST as a live vector vaccine

    USDA-ARS?s Scientific Manuscript database

    The Rhipicephalus microplus tick is a notorious blood-feeding ectoparasite of livestock, especially cattle, responsible for massive losses in animal production. It is the main vector for transmission of pathogenic bacteria and parasites, including Babesia bovis, an intraerythrocytic apicomplexan pro...

  11. Increased efficacy of an adenovirus-vectored foot-and-mouth disease capsid subunit vaccine expressing nonstructural protein 2B is associated with a specific T cell response.

    PubMed

    Moraes, Mauro Pires; Segundo, Fayna Diaz-San; Dias, Camila C; Pena, Lindomar; Grubman, Marvin J

    2011-11-28

    We previously demonstrated that an adenovirus-based foot-and-mouth disease virus (FMDV) serotype A24 capsid subunit vaccine, Ad5-A24, expressed under the control of a cytomegalovirus promoter (CMV) can protect swine and bovines against homologous challenge, but in a similar approach using swine vaccinated with an Ad5-vectored FMDV O1 Campos vaccine, Ad5-O1C, the animals were only partially protected when challenged at 21 days post-vaccination (dpv). Recently, we demonstrated that inclusion of the complete coding region of nonstructural protein 2B in the Ad5-A24 vector resulted in improved immune responses in pigs. We also found that inclusion of a modified CMV promoter (pCI), Ad5-CI-A24-2B, enhanced the efficacy of the vector. To address the limited immunogenicity of Ad5-O1C, we have produced a new set of Ad5 vectors with the complete 2B coding region under the control of either the original or the modified version of the CMV promoter, Ad5-O1C-2B, or Ad5-CI-O1C-2B, respectively. To evaluate the potency and efficacy of the new vectors we performed 2 sets of experiments in cattle. In the first experiment we compared the original vector with vectors containing the pCI promoter and partial or full-length 2B. All groups were challenged, intradermally in the tongue, at 21 dpv with FMDV O1C. We found that in all vaccinated groups 2 of 4 animals were protected from clinical disease. In the second experiment we directly compared the efficacy of vectors with a partial or full-length 2B under the control of the original CMV promoter. While all animals in the control group developed clinical disease, 2 of 4 animals in the group receiving Ad5-O1C vaccine and 3 of 4 animals in the group receiving Ad5-O1C-2B vaccine were completely protected after challenge. We also observed a 100-fold reduction of virus shedding in Ad5-O1C vaccinated animals and the group receiving Ad5-O1C-2B had an additional 10-fold reduction compared with the Ad5-O1C vaccinated group. There was no difference

  12. Pre-Clinical Development of a Recombinant, Replication-Competent Adenovirus Serotype 4 Vector Vaccine Expressing HIV-1 Envelope 1086 Clade C

    PubMed Central

    Alexander, Jeff; Mendy, Jason; Vang, Lo; Avanzini, Jenny B.; Garduno, Fermin; Manayani, Darly J.; Ishioka, Glenn; Farness, Peggy; Ping, Li-Hua; Swanstrom, Ronald; Parks, Robert; Liao, Hua-Xin; Haynes, Barton F.; Montefiori, David C.; LaBranche, Celia; Smith, Jonathan; Gurwith, Marc; Mayall, Tim

    2013-01-01

    Background There is a well-acknowledged need for an effective AIDS vaccine that protects against HIV-1 infection or limits in vivo viral replication. The objective of these studies is to develop a replication-competent, vaccine vector based on the adenovirus serotype 4 (Ad4) virus expressing HIV-1 envelope (Env) 1086 clade C glycoprotein. Ad4 recombinant vectors expressing Env gp160 (Ad4Env160), Env gp140 (Ad4Env140), and Env gp120 (Ad4Env120) were evaluated. Methods The recombinant Ad4 vectors were generated with a full deletion of the E3 region of Ad4 to accommodate the env gene sequences. The vaccine candidates were assessed in vitro following infection of A549 cells for Env-specific protein expression and for posttranslational transport to the cell surface as monitored by the binding of broadly neutralizing antibodies (bNAbs). The capacity of the Ad4Env vaccines to induce humoral immunity was evaluated in rabbits for Env gp140 and V1V2-specific binding antibodies, and HIV-1 pseudovirus neutralization. Mice immunized with the Ad4Env160 vaccine were assessed for IFNγ T cell responses specific for overlapping Env peptide sets. Results Robust Env protein expression was confirmed by western blot analysis and recognition of cell surface Env gp160 by multiple bNAbs. Ad4Env vaccines induced humoral immune responses in rabbits that recognized Env 1086 gp140 and V1V2 polypeptide sequences derived from 1086 clade C, A244 clade AE, and gp70 V1V2 CASE A2 clade B fusion protein. The immune sera efficiently neutralized tier 1 clade C pseudovirus MW965.26 and neutralized the homologous and heterologous tier 2 pseudoviruses to a lesser extent. Env-specific T cell responses were also induced in mice following Ad4Env160 vector immunization. Conclusions The Ad4Env vaccine vectors express high levels of Env glycoprotein and induce both Env-specific humoral and cellular immunity thus supporting further development of this new Ad4 HIV-1 Env vaccine platform in Phase 1 clinical

  13. Evaluation of the Protection Efficacy of a Serotype 1 Marek's Disease Virus-Vectored Bivalent Vaccine Against Infectious Laryngotracheitis and Marek's Disease.

    PubMed

    Gimeno, Isabel M; Cortes, Aneg L; Faiz, Nik M; Hernandez-Ortiz, Byron A; Guy, James S; Hunt, Henry D; Silva, Robert F

    2015-06-01

    Laryngotracheitis (LT) is a highly contagious respiratory disease of chickens that produces significant economic losses to the poultry industry. Traditionally, LT has been controlled by administration of modified live vaccines. In recent years, the use of recombinant DNA-derived vaccines using turkey herpesvirus (HVT) and fowlpox virus has expanded, as they protect not only against the vector used but also against LT. However, HVT-based vaccines confer limited protection against challenge, with emergent very virulent plus Marek's disease virus (vv+MDV). Serotype 1 vaccines have been proven to be the most efficient against vv+MDV. In particular, deletion of oncogene MEQ from the oncogenic vvMDV strain Md5 (BACδMEQ) resulted in a very efficient vaccine against vv+MDV. In this work, we have developed two recombinant vaccines against MD and LT by using BACδMEQ as a vector that carries either the LT virus (LTV) gene glycoprotein B (gB; BACΔMEQ-gB) or LTV gene glycoprotein J (gJ; BACδMEQ-gJ). We have evaluated the protection that these recombinant vaccines confer against MD and LT challenge when administered alone or in combination. Our results demonstrated that both bivalent vaccines (BACΔMEQ-gB and BACδMEQ-gJ) replicated in chickens and were safe to use in commercial meat-type chickens bearing maternal antibodies against MDV. BACΔMEQ-gB protected as well as a commercial recombinant (r)HVT-LT vaccine against challenge with LTV. However, BACδMEQ-gJ did not protect adequately against LT challenge or increase protection conferred by BACΔMEQ-gB when administered in combination. On the other hand, both BACΔMEQ-gB and BACδMEQ-gJ, administered alone or in combination, protected better against an early challenge with vv+MDV strain 648A than commercial strains of rHVT-LT or CVI988. Our results open a new avenue in the development of recombinant vaccines by using serotype 1 MDV as vectors.

  14. Assessment of a vaccinia virus vectored multi-epitope live vaccine candidate for Plasmodium falciparum.

    PubMed

    Dong, W; Li, M; Bi, H; Li, Y; Wu, J; Qu, L

    2001-01-01

    We constructed a live recombinant vaccinia virus vaccine candidate containing a synthesised hybrid gene termed 'HGFSP' encoding circumsporozoite protein (CSP), major merozoite surface antigen-1(MSA1), major merozoite surface antigen-2 (MSA2), and ring-infected erythrocyte surface antigen (RESA) of Plasmodium falciparum, interleukin-1 (IL-1) and tetanus toxin (TT) epitopes. Anti-recombinant vaccinia virus rabbit sera and IgG were tested in inhibition experiments in vitro. Results showed that the recombinant vaccinia virus had some capability to inhibit the growth of P. falciparum in vitro. The sera of rabbits, rats, and mice immunised with recombinant virus showed obvious IL-2 activity 4-6 weeks after immunisation. The interferon (IFN) level of sera from these animals 6 weeks after immunisation was significantly higher than before immunisation. These results indicate that the recombinant vaccinia virus can stimulate cell mediated responses (Th1 cell response) in immunised animals, and has the capability to inhibit multiplication of in vitro cultured P. falciparum. Thus this recombinant vaccinia virus is an appropriate vaccine candidate for further evaluation in Aotus monkey or human clinical trails.

  15. Priming T-cell responses with recombinant measles vaccine vector in a heterologous prime-boost setting in non-human primates.

    PubMed

    Bolton, Diane L; Santra, Sampa; Swett-Tapia, Cindy; Custers, Jerome; Song, Kaimei; Balachandran, Harikrishnan; Mach, Linh; Naim, Hussein; Kozlowski, Pamela A; Lifton, Michelle; Goudsmit, Jaap; Letvin, Norman; Roederer, Mario; Radošević, Katarina

    2012-09-07

    Licensed live attenuated virus vaccines capable of expressing transgenes from other pathogens have the potential to reduce the number of childhood immunizations by eliciting robust immunity to multiple pathogens simultaneously. Recombinant attenuated measles virus (rMV) derived from the Edmonston Zagreb vaccine strain was engineered to express simian immunodeficiency virus (SIV) Gag protein for the purpose of evaluating the immunogenicity of rMV as a vaccine vector in rhesus macaques. rMV-Gag immunization alone elicited robust measles-specific humoral and cellular responses, but failed to elicit transgene (Gag)-specific immune responses, following aerosol or intratracheal/intramuscular delivery. However, when administered as a priming vaccine to a heterologous boost with recombinant adenovirus serotype 5 expressing the same transgene, rMV-Gag significantly enhanced Gag-specific T lymphocyte responses following rAd5 immunization. Gag-specific humoral responses were not enhanced, however, which may be due to either the transgene or the vector. Cellular response priming by rMV against the transgene was highly effective even when using a suboptimal dose of rAd5 for the boost. These data demonstrate feasibility of using rMV as a priming component of heterologous prime-boost vaccine regimens for pathogens requiring strong cellular responses.

  16. Priming T-cell responses with recombinant measles vaccine vector in a heterologous prime-boost setting in non-human primates

    PubMed Central

    Bolton, Diane L.; Santra, Sampa; Swett, Cindy; Custers, Jerome; Song, Kaimei; Balachandran, Harikrishnan; Kozlowski, Pamela A.; Letvin, Norman; Roederer, Mario

    2012-01-01

    Licensed live attenuated virus vaccines capable of expressing transgenes from other pathogens have the potential to reduce the number of childhood immunizations by eliciting robust immunity to multiple pathogens simultaneously. Recombinant attenuated measles virus (rMV) derived from the Edmonston Zagreb vaccine strain was engineered to express simian immunodeficiency virus (SIV) Gag protein for the purpose of evaluating the immunogenicity of rMV as a vaccine vector in rhesus macaques. rMV-Gag immunization alone elicited robust measles-specific humoral and cellular responses, but failed to elicit transgene (Gag)-specific immune responses, following aerosol or intratracheal/intramuscular delivery. However, when administered as a priming vaccine to a heterologous boost with recombinant adenovirus serotype 5 expressing the same transgene, rMV-Gag significantly enhanced Gag-specific T lymphocyte responses following rAd5 immunization. Gag-specific humoral responses were not enhanced, however, which may be due to either the transgene or the vector. Cellular response priming by rMV against the transgene was highly effective even when using a suboptimal dose of rAd5 for the boost. These data demonstrate feasibility of using rMV as a priming component of heterologous prime-boost vaccine regimens for pathogens requiring strong cellular responses. PMID:22732429

  17. Combining Viral Vectored and Protein-in-adjuvant Vaccines Against the Blood-stage Malaria Antigen AMA1: Report on a Phase 1a Clinical Trial

    PubMed Central

    Hodgson, Susanne H; Choudhary, Prateek; Elias, Sean C; Milne, Kathryn H; Rampling, Thomas W; Biswas, Sumi; Poulton, Ian D; Miura, Kazutoyo; Douglas, Alexander D; Alanine, Daniel GW; Illingworth, Joseph J; de Cassan, Simone C; Zhu, Daming; Nicosia, Alfredo; Long, Carole A; Moyle, Sarah; Berrie, Eleanor; Lawrie, Alison M; Wu, Yimin; Ellis, Ruth D; Hill, Adrian V S; Draper, Simon J

    2014-01-01

    The development of effective vaccines against difficult disease targets will require the identification of new subunit vaccination strategies that can induce and maintain effective immune responses in humans. Here we report on a phase 1a clinical trial using the AMA1 antigen from the blood-stage Plasmodium falciparum malaria parasite delivered either as recombinant protein formulated with Alhydrogel adjuvant with and without CPG 7909, or using recombinant vectored vaccines—chimpanzee adenovirus ChAd63 and the orthopoxvirus MVA. A variety of promising “mixed-modality” regimens were tested. All volunteers were primed with ChAd63, and then subsequently boosted with MVA and/or protein-in-adjuvant using either an 8- or 16-week prime-boost interval. We report on the safety of these regimens, as well as the T cell, B cell, and serum antibody responses. Notably, IgG antibody responses primed by ChAd63 were comparably boosted by AMA1 protein vaccine, irrespective of whether CPG 7909 was included in the Alhydrogel adjuvant. The ability to improve the potency of a relatively weak aluminium-based adjuvant in humans, by previously priming with an adenoviral vaccine vector encoding the same antigen, thus offers a novel vaccination strategy for difficult or neglected disease targets when access to more potent adjuvants is not possible. PMID:25156127

  18. Mucosal Trafficking of Vector-Specific CD4+ T Lymphocytes following Vaccination of Rhesus Monkeys with Adenovirus Serotype 5▿ †

    PubMed Central

    Masek-Hammerman, Katherine; Li, Hualin; Liu, Jinyan; Abbink, Peter; La Porte, Annalena; O'Brien, Kara L.; Whitney, James B.; Carville, Angela; Mansfield, Keith G.; Barouch, Dan H.

    2010-01-01

    Post hoc analysis of the phase 2b Step study evaluating a recombinant adenovirus serotype 5 (rAd5)-based HIV-1 vaccine candidate suggested a potential increased risk of HIV-1 acquisition in subjects who were baseline Ad5 seropositive and uncircumcised. These concerns had a profound impact on the HIV-1 vaccine development field, although the mechanism underlying this observation remains unknown. It has been hypothesized that rAd5 vaccination of baseline Ad5-seropositive individuals may have resulted in anamnestic, vector-specific CD4+ T lymphocytes that could have trafficked to mucosal sites and served as increased targets for HIV-1 infection. Here we show that Ad5-specific CD4+ T lymphocyte responses at mucosal sites following rAd5-Gag/Pol/Nef vaccination were comparable in rhesus monkeys with and without baseline Ad5 immunity. Moreover, the total cellular inflammatory infiltrates and the CD3+, CD4+, HLA-DR+, Ki67+, and langerin+ cellular subpopulations in colorectal and foreskin mucosa were similar in both groups. Thus, no greater trafficking of Ad5-specific CD4+ T lymphocytes to mucosal target sites was observed following rAd5 vaccination of rhesus monkeys with baseline Ad5 immunity. These findings from this nonhuman primate model provide evidence against the hypothesis that recruitment of vector-specific target cells to mucosal sites led to increased HIV-1 acquisition in Ad5-seropositive, uncircumcised vaccinees in the Step study. PMID:20686023

  19. Adenovirus-vectored foot-and-mouth disease vaccine confers early and full protection against FMDV O1 Manisa in swine.

    PubMed

    Fernandez-Sainz, Ignacio; Medina, Gisselle N; Ramirez-Medina, Elizabeth; Koster, Marla J; Grubman, Marvin J; de Los Santos, Teresa

    2017-02-01

    A human adenovirus (Ad5) vectored foot-and-mouth disease virus (FMDV) O1-Manisa subunit vaccine (Ad5-O1Man) was engineered to deliver FMDV O1-Manisa capsid and capsid-processing proteins. Swine inoculated with Ad5-O1Man developed an FMDV-specific humoral response as compared to animals inoculated with an empty Ad5-vector. Vaccinated animals were completely protected against homologous challenge at 7 or 21 days post-vaccination. Potency studies exhibited a PD50 of about 10(7) pfu/animal while a dose of 4×10(7)pfu/animal fully protected swine against FMDV intradermal challenge. In-vitro cross-neutralization analysis distinctly predicted that swine vaccinated with Ad5-O1Man would be protected against challenge with homologous FMDV O1Man Middle East-South Asia (ME-SA) topotype and also against recent outbreak strains of Mya-98 South East Asia (SEA) lineage including O1-UK-2001 and O1-South Korea-2010. These results indicate that recombinant Ad5-O1Man is an effective, safe and cross-reacting vaccine that could potentially be used preventively and in outbreak situations, to control FMDV O Mya-98 lineage in swine. Published by Elsevier Inc.

  20. Protective immunization of horses with a recombinant canarypox virus vectored vaccine co-expressing genes encoding the outer capsid proteins of African horse sickness virus.

    PubMed

    Guthrie, Alan J; Quan, Melvyn; Lourens, Carina W; Audonnet, Jean-Christophe; Minke, Jules M; Yao, Jiansheng; He, Ling; Nordgren, Robert; Gardner, Ian A; Maclachlan, N James

    2009-07-16

    We describe the development and preliminary characterization of a recombinant canarypox virus vectored (ALVAC) vaccine for protective immunization of equids against African horse sickness virus (AHSV) infection. Horses (n=8) immunized with either of two concentrations of recombinant canarypox virus vector (ALVAC-AHSV) co-expressing synthetic genes encoding the outer capsid proteins (VP2 and VP5) of AHSV serotype 4 (AHSV-4) developed variable titres (<10-80) of virus-specific neutralizing antibodies and were completely resistant to challenge infection with a virulent strain of AHSV-4. In contrast, a horse immunized with a commercial recombinant canarypox virus vectored vaccine expressing the haemagglutinin genes of two equine influenza H3N8 viruses was seronegative to AHSV and following infection with virulent AHSV-4 developed pyrexia, thrombocytopenia and marked oedema of the supraorbital fossae typical of the "dikkop" or cardiac form of African horse sickness. AHSV was detected by virus isolation and quantitative reverse transcriptase polymerase chain reaction in the blood of the control horse from 8 days onwards after challenge infection whereas AHSV was not detected at any time in the blood of the ALVAC-AHSV vaccinated horses. The control horse seroconverted to AHSV by 2 weeks after challenge infection as determined by both virus neutralization and ELISA assays, whereas six of eight of the ALVAC-AHSV vaccinated horses did not seroconvert by either assay following challenge infection with virulent AHSV-4. These data confirm that the ALVAC-AHSV vaccine will be useful for the protective immunization of equids against African horse sickness, and avoids many of the problems inherent to live-attenuated AHSV vaccines.

  1. Early life vaccination: Generation of adult-quality memory CD8+ T cells in infant mice using non-replicating adenoviral vectors.

    PubMed

    Nazerai, Loulieta; Bassi, Maria R; Uddback, Ida E M; Holst, Peter J; Christensen, Jan P; Thomsen, Allan R

    2016-12-08

    Intracellular pathogens represent a serious threat during early life. Importantly, even though the immune system of newborns may be characterized as developmentally immature, with a propensity to develop Th2 immunity, significant CD8+ T-cell responses may still be elicited in the context of optimal priming. Replication deficient adenoviral vectors have been demonstrated to induce potent CD8+ T-cell response in mice, primates and humans. The aim of the present study was therefore to assess whether replication-deficient adenovectors could overcome the risk of overwhelming antigen stimulation during the first period of life and provide a pertinent alternative in infant vaccinology. To address this, infant mice were vaccinated with three different adenoviral vectors and the CD8+ T-cell response after early life vaccination was explored. We assessed the frequency, polyfunctionality and in vivo cytotoxicity of the elicited memory CD8+ T cells, as well as the potential of these cells to respond to secondary infections and confer protection. We further tested the impact of maternal immunity against our replication-deficient adenoviral vector during early life vaccination. Overall, our results indicate that memory CD8+ T cells induced by adenoviral vectors in infant mice are of good quality and match those elicited in the adult host.

  2. A phase I trial of preventive HIV vaccination with heterologous poxviral-vectors containing matching HIV-1 inserts in healthy HIV-uninfected subjects

    PubMed Central

    Keefer, Michael C.; Frey, Sharon E.; Elizaga, Marnie; Metch, Barbara; De Rosa, Stephen C.; Barroso, Paulo F.; Tomaras, Georgia; Cardinali, Massimo; Goepfert, Paul; Kalichman, Artur; Philippon, Valérie; McElrath, M. Juliana; Jin, Xia; Ferrari, Guido; Defawe, Olivier D.; Mazzara, Gail P.; Montefiori, David; Pensiero, Michael; Panicali, Dennis L.; Corey, Lawrence

    2011-01-01

    We evaluated replication-defective poxvirus vectors (modified vaccinia Ankara [MVA] and fowlpox [FPV]) in a homologous and heterologous vector prime-boost vaccination regimen containing matching HIV inserts (MVA-HIV and FPV-HIV) given at months 0, 1, 3, 5 and 7 in 150 healthy HIV-negative vaccinia-naïve participants. FPV-HIV alone was poorly immunogenic, while the high dose (109 pfu/2ml) of MVA-HIV alone elicited maximal responses after two injections: CD4+ and CD8+ T-cell responses in 26/55 (47.3%) and 5/60 (8.3%) of participants, respectively and IFN-γ ELISpot responses in 28/62 (45.2%). The infrequent CD8+ T-cell responses following MVA-HIV priming were boosted only by the heterologous (FPV-HIV) construct in 14/27 [51.9%] of participants post-4th vaccination. Alternatively, HIV envelope-specific binding antibodies were demonstrated in approximately two-thirds of recipients of the homologous boosting regimen, but in less than 20% of subjects after the heterologous vector boost. Thus, a heterologous poxvirus vector prime-boost regimen can induce an HIV-specific CD8+ T-cell and CD4+ T-cell responses, which may be an important feature of an optimal regimen for preventive HIV vaccination. PMID:21216311

  3. 4-1BBL Enhances CD8+ T Cell Responses Induced by Vectored Vaccines in Mice but Fails to Improve Immunogenicity in Rhesus Macaques

    PubMed Central

    Spencer, Alexandra J.; Furze, Julie; Honeycutt, Jared D.; Calvert, Alice; Saurya, Saroj; Colloca, Stefano; Wyllie, David H.; Gilbert, Sarah C.; Bregu, Migena; Cottingham, Matthew G.; Hill, Adrian V. S.

    2014-01-01

    T cells play a central role in the immune response to many of the world’s major infectious diseases. In this study we investigated the tumour necrosis factor receptor superfamily costimulatory molecule, 4-1BBL (CD137L, TNFSF9), for its ability to increase T cell immunogenicity induced by a variety of recombinant vectored vaccines. To efficiently test this hypothesis, we assessed a number of promoters and developed a stable bi-cistronic vector expressing both the antigen and adjuvant. Co-expression of 4-1BBL, together with our model antigen TIP, was shown to increase the frequency of murine antigen-specific IFN-γ secreting CD8+ T cells in three vector platforms examined. Enhancement of the response was not limited by co-expression with the antigen, as an increase in CD8+ immunogenicity was also observed by co-administration of two vectors each expressing only the antigen or adjuvant. However, when this regimen was tested in non-human primates using a clinical malaria vaccine candidate, no adjuvant effect of 4-1BBL was observed limiting its potential use as a single adjuvant for translation into a clinical vaccine. PMID:25140889

  4. Early life vaccination: Generation of adult-quality memory CD8+ T cells in infant mice using non-replicating adenoviral vectors

    PubMed Central

    Nazerai, Loulieta; Bassi, Maria R.; Uddback, Ida E. M.; Holst, Peter J.; Christensen, Jan P.; Thomsen, Allan R.

    2016-01-01

    Intracellular pathogens represent a serious threat during early life. Importantly, even though the immune system of newborns may be characterized as developmentally immature, with a propensity to develop Th2 immunity, significant CD8+ T-cell responses may still be elicited in the context of optimal priming. Replication deficient adenoviral vectors have been demonstrated to induce potent CD8+ T-cell response in mice, primates and humans. The aim of the present study was therefore to assess whether replication-deficient adenovectors could overcome the risk of overwhelming antigen stimulation during the first period of life and provide a pertinent alternative in infant vaccinology. To address this, infant mice were vaccinated with three different adenoviral vectors and the CD8+ T-cell response after early life vaccination was explored. We assessed the frequency, polyfunctionality and in vivo cytotoxicity of the elicited memory CD8+ T cells, as well as the potential of these cells to respond to secondary infections and confer protection. We further tested the impact of maternal immunity against our replication-deficient adenoviral vector during early life vaccination. Overall, our results indicate that memory CD8+ T cells induced by adenoviral vectors in infant mice are of good quality and match those elicited in the adult host. PMID:27929135

  5. Expression of chicken parvovirus VP2 in chicken embryo fibroblasts requires codon optimization for production of naked DNA and vectored meleagrid herpesvirus type 1 vaccines.

    PubMed

    Spatz, Stephen J; Volkening, Jeremy D; Mullis, Robert; Li, Fenglan; Mercado, John; Zsak, Laszlo

    2013-10-01

    Meleagrid herpesvirus type 1 (MeHV-1) is an ideal vector for the expression of antigens from pathogenic avian organisms in order to generate vaccines. Chicken parvovirus (ChPV) is a widespread infectious virus that causes serious disease in chickens. It is one of the etiological agents largely suspected in causing Runting Stunting Syndrome (RSS) in chickens. Initial attempts to express the wild-type gene encoding the capsid protein VP2 of ChPV by insertion into the thymidine kinase gene of MeHV-1 were unsuccessful. However, transient expression of a codon-optimized synthetic VP2 gene cloned into the bicistronic vector pIRES2-Ds-Red2, could be demonstrated by immunocytochemical staining of transfected chicken embryo fibroblasts (CEFs). Red fluorescence could also be detected in these transfected cells since the red fluorescent protein gene is downstream from the internal ribosome entry site (IRES). Strikingly, fluorescence could not be demonstrated in cells transiently transfected with the bicistronic vector containing the wild-type or non-codon-optimized VP2 gene. Immunocytochemical staining of these cells also failed to demonstrate expression of wild-type VP2, indicating that the lack of expression was at the RNA level and the VP2 protein was not toxic to CEFs. Chickens vaccinated with a DNA vaccine consisting of the bicistronic vector containing the codon-optimized VP2 elicited a humoral immune response as measured by a VP2-specific ELISA. This VP2 codon-optimized bicistronic cassette was rescued into the MeHV-1 genome generating a vectored vaccine against ChPV disease.

  6. Effect of rAd5-Vector HIV-1 Preventive Vaccines on HIV-1 Acquisition: A Participant-Level Meta-Analysis of Randomized Trials.

    PubMed

    Huang, Yunda; Follmann, Dean; Nason, Martha; Zhang, Lily; Huang, Ying; Mehrotra, Devan V; Moodie, Zoe; Metch, Barbara; Janes, Holly; Keefer, Michael C; Churchyard, Gavin; Robb, Merlin L; Fast, Patricia E; Duerr, Ann; McElrath, M Juliana; Corey, Lawrence; Mascola, John R; Graham, Barney S; Sobieszczyk, Magdalena E; Kublin, James G; Robertson, Michael; Hammer, Scott M; Gray, Glenda E; Buchbinder, Susan P; Gilbert, Peter B

    2015-01-01

    Three phase 2b, double-blind, placebo-controlled, randomized efficacy trials have tested recombinant Adenovirus serotype-5 (rAd5)-vector preventive HIV-1 vaccines: MRKAd5 HIV-1 gag/pol/nef in Step and Phambili, and DNA/rAd5 HIV-1 env/gag/pol in HVTN505. Due to efficacy futility observed at the first interim analysis in Step and HVTN505, participants of all three studies were unblinded to their vaccination assignments during the study but continued follow-up. Rigorous meta-analysis can provide crucial information to advise the future utility of rAd5-vector vaccines. We included participant-level data from all three efficacy trials, and three Phase 1-2 trials evaluating the HVTN505 vaccine regimen. We predefined two co-primary analysis cohorts for assessing the vaccine effect on HIV-1 acquisition. The modified-intention-to-treat (MITT) cohort included all randomly assigned participants HIV-1 uninfected at study entry, who received at least the first vaccine/placebo, and the Ad5 cohort included MITT participants who received at least one dose of rAd5-HIV vaccine or rAd5-placebo. Multivariable Cox regression models were used to estimate hazard ratios (HRs) of HIV-1 infection (vaccine vs. placebo) and evaluate HR variation across vaccine regimens, time since vaccination, and subgroups using interaction tests. Results are similar for the MITT and Ad5 cohorts; we summarize MITT cohort results. Pooled across the efficacy trials, over all follow-up time 403 (n = 224 vaccine; n = 179 placebo) of 6266 MITT participants acquired HIV-1, with a non-significantly higher incidence in vaccine recipients (HR 1.21, 95% CI 0.99-1.48, P = 0.06). The HRs significantly differed by vaccine regimen (interaction P = 0.03; MRKAd5 HR 1.41, 95% CI 1.11-1.78, P = 0.005 vs. DNA/rAd5 HR 0.88, 95% CI 0.61-1.26, P = 0.48). Results were similar when including the Phase 1-2 trials. Exploratory analyses based on the efficacy trials supported that the MRKAd5 vaccine-increased risk was concentrated in

  7. Effect of rAd5-Vector HIV-1 Preventive Vaccines on HIV-1 Acquisition: A Participant-Level Meta-Analysis of Randomized Trials

    PubMed Central

    Huang, Yunda; Follmann, Dean; Nason, Martha; Zhang, Lily; Huang, Ying; Mehrotra, Devan V.; Moodie, Zoe; Metch, Barbara; Janes, Holly; Keefer, Michael C.; Churchyard, Gavin; Robb, Merlin L.; Fast, Patricia E.; Duerr, Ann; McElrath, M. Juliana; Corey, Lawrence; Mascola, John R.; Graham, Barney S.; Sobieszczyk, Magdalena E.; Kublin, James G.; Robertson, Michael; Hammer, Scott M.; Gray, Glenda E.; Buchbinder, Susan P.; Gilbert, Peter B.

    2015-01-01

    Background Three phase 2b, double-blind, placebo-controlled, randomized efficacy trials have tested recombinant Adenovirus serotype-5 (rAd5)-vector preventive HIV-1 vaccines: MRKAd5 HIV-1 gag/pol/nef in Step and Phambili, and DNA/rAd5 HIV-1 env/gag/pol in HVTN505. Due to efficacy futility observed at the first interim analysis in Step and HVTN505, participants of all three studies were unblinded to their vaccination assignments during the study but continued follow–up. Rigorous meta-analysis can provide crucial information to advise the future utility of rAd5-vector vaccines. Methods We included participant-level data from all three efficacy trials, and three Phase 1–2 trials evaluating the HVTN505 vaccine regimen. We predefined two co-primary analysis cohorts for assessing the vaccine effect on HIV-1 acquisition. The modified-intention-to-treat (MITT) cohort included all randomly assigned participants HIV-1 uninfected at study entry, who received at least the first vaccine/placebo, and the Ad5 cohort included MITT participants who received at least one dose of rAd5-HIV vaccine or rAd5-placebo. Multivariable Cox regression models were used to estimate hazard ratios (HRs) of HIV-1 infection (vaccine vs. placebo) and evaluate HR variation across vaccine regimens, time since vaccination, and subgroups using interaction tests. Findings Results are similar for the MITT and Ad5 cohorts; we summarize MITT cohort results. Pooled across the efficacy trials, over all follow-up time 403 (n = 224 vaccine; n = 179 placebo) of 6266 MITT participants acquired HIV-1, with a non-significantly higher incidence in vaccine recipients (HR 1.21, 95% CI 0.99–1.48, P = 0.06). The HRs significantly differed by vaccine regimen (interaction P = 0.03; MRKAd5 HR 1.41, 95% CI 1.11–1.78, P = 0.005 vs. DNA/rAd5 HR 0.88, 95% CI 0.61–1.26, P = 0.48). Results were similar when including the Phase 1–2 trials. Exploratory analyses based on the efficacy trials supported that the MRKAd5

  8. A Bivalent Typhoid Live Vector Vaccine Expressing both Chromosome- and Plasmid-Encoded Yersinia pestis Antigens Fully Protects against Murine Lethal Pulmonary Plague Infection

    PubMed Central

    Wang, Jin Yuan; Carrasco, Jose A.; Lloyd, Scott A.; Mellado-Sanchez, Gabriela; Diaz-McNair, Jovita; Franco, Olga; Buskirk, Amanda D.; Nataro, James P.; Pasetti, Marcela F.

    2014-01-01

    Live attenuated bacteria hold great promise as multivalent mucosal vaccines against a variety of pathogens. A major challenge of this approach has been the successful delivery of sufficient amounts of vaccine antigens to adequately prime the immune system without overattenuating the live vaccine. Here we used a live attenuated Salmonella enterica serovar Typhi strain to create a bivalent mucosal plague vaccine that produces both the protective F1 capsular antigen of Yersinia pestis and the LcrV protein required for secretion of virulence effector proteins. To reduce the metabolic burden associated with the coexpression of F1 and LcrV within the live vector, we balanced expression of both antigens by combining plasmid-based expression of F1 with chromosomal expression of LcrV from three independent loci. The immunogenicity and protective efficacy of this novel vaccine were assessed in mice by using a heterologous prime-boost immunization strategy and compared to those of a conventional strain in which F1 and LcrV were expressed from a single low-copy-number plasmid. The serum antibody responses to lipopolysaccharide (LPS) induced by the optimized bivalent vaccine were indistinguishable from those elicited by the parent strain, suggesting an adequate immunogenic capacity maintained through preservation of bacterial fitness; in contrast, LPS titers were 10-fold lower in mice immunized with the conventional vaccine strain. Importantly, mice receiving the optimized bivalent vaccine were fully protected against lethal pulmonary challenge. These results demonstrate the feasibility of distributing foreign antigen expression across both chromosomal and plasmid locations within a single vaccine organism for induction of protective immunity. PMID:25332120

  9. A Multi-Antigenic Adenoviral-Vectored Vaccine Improves BCG-Induced Protection of Goats against Pulmonary Tuberculosis Infection and Prevents Disease Progression

    PubMed Central

    Pérez de Val, Bernat; Vidal, Enric; Villarreal-Ramos, Bernardo; Gilbert, Sarah C.; Andaluz, Anna; Moll, Xavier; Martín, Maite; Nofrarías, Miquel; McShane, Helen; Vordermeier, H. Martin; Domingo, Mariano

    2013-01-01

    The “One world, one health” initiative emphasizes the need for new strategies to control human and animal tuberculosis (TB) based on their shared interface. A good example would be the development of novel universal vaccines against Mycobacterium tuberculosis complex (MTBC) infection. This study uses the goat model, a natural TB host, to assess the protective effectiveness of a new vaccine candidate in combination with Bacillus Calmette-Guerin (BCG) vaccine. Thirty-three goat kids were divided in three groups: Group 1) vaccinated with BCG (week 0), Group 2) vaccinated with BCG and boosted 8 weeks later with a recombinant adenovirus expressing the MTBC antigens Ag85A, TB10.4, TB9.8 and Acr2 (AdTBF), and Group 3) unvaccinated controls. Later on, an endobronchial challenge with a low dose of M. caprae was performed (week 15). After necropsy (week 28), the pulmonary gross pathology was quantified using high resolution Computed Tomography. Small granulomatous pulmonary lesions (< 0.5 cm diameter) were also evaluated through a comprehensive qualitative histopathological analysis. M. caprae CFU were counted from pulmonary lymph nodes. The AdTBF improved the effects of BCG reducing gross lesion volume and bacterial load, as well as increasing weight gain. The number of Ag85A-specific gamma interferon-producing memory T-cells was identified as a predictor of vaccine efficacy. Specific cellular and humoral responses were measured throughout the 13-week post-challenge period, and correlated with the severity of lesions. Unvaccinated goats exhibited the typical pathological features of active TB in humans and domestic ruminants, while vaccinated goats showed only very small lesions. The data presented in this study indicate that multi-antigenic adenoviral vectored vaccines boosts protection conferred by vaccination with BCG. PMID:24278420

  10. A bivalent typhoid live vector vaccine expressing both chromosome- and plasmid-encoded Yersinia pestis antigens fully protects against murine lethal pulmonary plague infection.

    PubMed

    Galen, James E; Wang, Jin Yuan; Carrasco, Jose A; Lloyd, Scott A; Mellado-Sanchez, Gabriela; Diaz-McNair, Jovita; Franco, Olga; Buskirk, Amanda D; Nataro, James P; Pasetti, Marcela F

    2015-01-01

    Live attenuated bacteria hold great promise as multivalent mucosal vaccines against a variety of pathogens. A major challenge of this approach has been the successful delivery of sufficient amounts of vaccine antigens to adequately prime the immune system without overattenuating the live vaccine. Here we used a live attenuated Salmonella enterica serovar Typhi strain to create a bivalent mucosal plague vaccine that produces both the protective F1 capsular antigen of Yersinia pestis and the LcrV protein required for secretion of virulence effector proteins. To reduce the metabolic burden associated with the coexpression of F1 and LcrV within the live vector, we balanced expression of both antigens by combining plasmid-based expression of F1 with chromosomal expression of LcrV from three independent loci. The immunogenicity and protective efficacy of this novel vaccine were assessed in mice by using a heterologous prime-boost immunization strategy and compared to those of a conventional strain in which F1 and LcrV were expressed from a single low-copy-number plasmid. The serum antibody responses to lipopolysaccharide (LPS) induced by the optimized bivalent vaccine were indistinguishable from those elicited by the parent strain, suggesting an adequate immunogenic capacity maintained through preservation of bacterial fitness; in contrast, LPS titers were 10-fold lower in mice immunized with the conventional vaccine strain. Importantly, mice receiving the optimized bivalent vaccine were fully protected against lethal pulmonary challenge. These results demonstrate the feasibility of distributing foreign antigen expression across both chromosomal and plasmid locations within a single vaccine organism for induction of protective immunity. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  11. Pre-clinical development of BCG.HIVA(CAT), an antibiotic-free selection strain, for HIV-TB pediatric vaccine vectored by lysine auxotroph of BCG.

    PubMed

    Saubi, Narcís; Mbewe-Mvula, Alice; Gea-Mallorqui, Ester; Rosario, Maximillian; Gatell, Josep Maria; Hanke, Tomáš; Joseph, Joan

    2012-01-01

    In the past, we proposed to develop a heterologous recombinant BCG prime-recombinant modified vaccinia virus Ankara (MVA) boost dual pediatric vaccine platform against transmission of breast milk HIV-1 and Mycobacterium tuberculosis (Mtb). In this study, we assembled an E. coli-mycobacterial shuttle plasmid pJH222.HIVA(CAT) expressing HIV-1 clade A immunogen HIVA. This shuttle vector employs an antibiotic resistance-free mechanism based on Operator-Repressor Titration (ORT) system for plasmid selection and maintenance in E. coli and lysine complementation in mycobacteria. This shuttle plasmid was electroporated into parental lysine auxotroph (safer) strain of BCG to generate vaccine BCG.HIVA(CAT). All procedures complied with Good Laboratory Practices (GLPs). We demonstrated that the episomal plasmid pJH222.HIVA(CAT) was stable in vivo over a 20-week period, and genetically and phenotypically characterized the BCG.HIVA(CAT) vaccine strain. The BCG.HIVA(CAT) vaccine in combination with MVA.HIVA induced HIV-1- and Mtb-specific interferon γ-producing T-cell responses in newborn and adult BALB/c mice. On the other hand, when adult mice were primed with BCG.HIVA(CAT) and boosted with MVA.HIVA.85A, HIV-1-specific CD8(+) T-cells producing IFN-γ, TNF-α, IL-2 and CD107a were induced. To assess the biosafety profile of BCG.HIVA(CAT)-MVA.HIVA regimen, body mass loss of newborn mice was monitored regularly throughout the vaccination experiment and no difference was observed between the vaccinated and naïve groups of animals. Thus, we demonstrated T-cell immunogenicity of a novel, safer, GLP-compatible BCG-vectored vaccine using prototype immunogen HIVA. Second generation immunogens derived from HIV-1 as well as other major pediatric pathogens can be constructed in a similar fashion to prime protective responses soon after birth.

  12. Replication-Competent Foamy Virus Vaccine Vectors as Novel Epitope Scaffolds for Immunotherapy

    PubMed Central

    Lei, Janet; Osen, Wolfram; Gardyan, Adriane; Hotz-Wagenblatt, Agnes; Wei, Guochao; Gissmann, Lutz; Eichmüller, Stefan; Löchelt, Martin

    2015-01-01

    The use of whole viruses as antigen scaffolds is a recent development in vaccination that improves immunogenicity without the need for additional adjuvants. Previous studies highlighted the potential of foamy viruses (FVs) in prophylactic vaccination and gene therapy. Replication-competent FVs can trigger immune signaling and integrate into the host genome, resulting in persistent antigen expression and a robust immune response. Here, we explored feline foamy virus (FFV) proteins as scaffolds for therapeutic B and T cell epitope delivery in vitro. Infection- and cancer-related B and T cell epitopes were grafted into FFV Gag, Env, or Bet by residue replacement, either at sites of high local sequence homology between the epitope and the host protein or in regions known to tolerate sequence alterations. Modified proviruses were evaluated in vitro for protein steady state levels, particle release, and virus titer in permissive cells. Modification of Gag and Env was mostly detrimental to their function. As anticipated, modification of Bet had no impact on virion release and affected virus titers of only some recombinants. Further evaluation of Bet as an epitope carrier was performed using T cell epitopes from the model antigen chicken ovalbumin (OVA), human tyrosinase-related protein 2 (TRP-2), and oncoprotein E7 of human papillomavirus type 16 (HPV16E7). Transfection of murine cells with constructs encoding Bet-epitope chimeric proteins led to efficient MHC-I-restricted epitope presentation as confirmed by interferon-gamma enzyme-linked immunospot assays using epitope-specific cytotoxic T lymphocyte (CTL) lines. FFV infection-mediated transduction of cells with epitope-carrying Bet also induced T-cell responses, albeit with reduced efficacy, in a process independent from the presence of free peptides. We show that primate FV Bet is also a promising T cell epitope carrier for clinical translation. The data demonstrate the utility of replication-competent and -attenuated

  13. [Vaccination].

    PubMed

    Graubner, U B; Liese, J; Belohradsky, B H

    2001-09-01

    Vaccination has been an important part of antiinfectious prophylaxis in pediatric oncology comprising immunizations with special indication like varicella vaccine and follow-up of routine immunizations after chemotherapy and bone marrow transplantation (BMT). Studies from the last decade demonstrate a loss of long term immunity to immunization preventable disease in most patients with chemotherapy and BMT who had received appropriate immunization before. So far routine vaccination programs following intensive chemotherapy have not been studied prospectively. Immunization programs following BMT have shown that immunizations with tetanus toxoid, diphtheria toxoid, inactivated poliovirus vaccine and influenza vaccine - given at least 12 months after transplantation - are safe and effective. Vaccination with live attenuated trivalent vaccine against measles, mumps and rubella in patients without chronic "graft versus host disease" (GVHD) and without ongoing immunosuppressive therapy, performed 24 months after transplantation, proved to be safe too. Recommendations have been published by 5 different official groups: (1.) "Ständige Impfkommission" (STIKO) and (2.) "Deutsche Gesellschaft für pädiatrische Infektiologie" (DGPI) recommend varicella vaccine für children with leukemia in remission for at least 12 months, for children with solid tumors and for patients getting an organ transplantation. Both societies do not comment on the schedule of booster vaccinations (with live attenuated vaccines) after the end of chemotherapy and after BMT. (3.) "Qualitätssicherungsgruppe" der "Gesellschaft für pädiatrische Onkologie und Hämatologie" (QS-GPOH) recommends immunization with nonliving vaccines when the patient is off therapy for at least 3 months and immunization with live attenuated vaccines when he is off therapy for at least 6 months. This group does not comment on varicella vaccine which has been controversial among pediatric oncologists. (4.) The " Infectious

  14. Vaccinations

    MedlinePlus

    ... be spread from animals to people. For example, rabies is a serious, often fatal, disease that can ... animals to people. By vaccinating your pets for rabies, you are protecting your family as well as ...

  15. Evaluation of the Efficacy, Potential for Vector Transmission, and Duration of Immunity of MP-12, an Attenuated Rift Valley Fever Virus Vaccine Candidate, in Sheep.

    PubMed

    Miller, Myrna M; Bennett, Kristine E; Drolet, Barbara S; Lindsay, Robbin; Mecham, James O; Reeves, Will K; Weingartl, Hana M; Wilson, William C

    2015-08-01

    Rift Valley fever virus (RVFV) causes serious disease in ruminants and humans in Africa. In North America, there are susceptible ruminant hosts and competent mosquito vectors, yet there are no fully licensed animal vaccines for this arthropod-borne virus, should it be introduced. Studies in sheep and cattle have found the attenuated strain of RVFV, MP-12, to be both safe and efficacious based on early testing, and a 2-year conditional license for use in U.S. livestock has been issued. The purpose of this study was to further determine the vaccine's potential to infect mosquitoes, the duration of humoral immunity to 24 months postvaccination, and the ability to prevent disease and viremia from a virulent challenge. Vaccination experiments conducted in sheep found no evidence of a potential for vector transmission to 4 North American mosquito species. Neutralizing antibodies were elicited, with titers of >1:40 still present at 24 months postvaccination. Vaccinates were protected from clinical signs and detectable viremia after challenge with virulent virus, while control sheep had fever and high-titered viremia extending for 5 days. Antibodies to three viral proteins (nucleocapsid N, the N-terminal half of glycoprotein GN, and the nonstructural protein from the short segment NSs) were also detected to 24 months using competitive enzyme-linked immunosorbent assays. This study demonstrates that the MP-12 vaccine given as a single dose in sheep generates protective immunity to a virulent challenge with antibody duration of at least 2 years, with no evidence of a risk for vector transmission.

  16. A human vaccine strategy based on chimpanzee adenoviral and MVA vectors that primes, boosts, and sustains functional HCV-specific T cell memory.

    PubMed

    Swadling, Leo; Capone, Stefania; Antrobus, Richard D; Brown, Anthony; Richardson, Rachel; Newell, Evan W; Halliday, John; Kelly, Christabel; Bowen, Dan; Fergusson, Joannah; Kurioka, Ayako; Ammendola, Virginia; Del Sorbo, Mariarosaria; Grazioli, Fabiana; Esposito, Maria Luisa; Siani, Loredana; Traboni, Cinzia; Hill, Adrian; Colloca, Stefano; Davis, Mark; Nicosia, Alfredo; Cortese, Riccardo; Folgori, Antonella; Klenerman, Paul; Barnes, Eleanor

    2014-11-05

    A protective vaccine against hepatitis C virus (HCV) remains an unmet clinical need. HCV infects millions of people worldwide and is a leading cause of liver cirrhosis and hepatocellular cancer. Animal challenge experiments, immunogenetics studies, and assessment of host immunity during acute infection highlight the critical role that effective T cell immunity plays in viral control. In this first-in-man study, we have induced antiviral immunity with functional characteristics analogous to those associated with viral control in natural infection, and improved upon a vaccine based on adenoviral vectors alone. We assessed a heterologous prime-boost vaccination strategy based on a replicative defective simian adenoviral vector (ChAd3) and modified vaccinia Ankara (MVA) vector encoding the NS3, NS4, NS5A, and NS5B proteins of HCV genotype 1b. Analysis used single-cell mass cytometry and human leukocyte antigen class I peptide tetramer technology in healthy human volunteers. We show that HCV-specific T cells induced by ChAd3 are optimally boosted with MVA, and generate very high levels of both CD8(+) and CD4(+) HCV-specific T cells targeting multiple HCV antigens. Sustained memory and effector T cell populations are generated, and T cell memory evolved over time with improvement of quality (proliferation and polyfunctionality) after heterologous MVA boost. We have developed an HCV vaccine strategy, with durable, broad, sustained, and balanced T cell responses, characteristic of those associated with viral control, paving the way for the first efficacy studies of a prophylactic HCV vaccine.

  17. A Human Vaccine Strategy Based On Chimpanzee Adenoviral and MVA Vectors That Primes, Boosts and Sustains Functional HCV Specific T-Cell Memory*

    PubMed Central

    Swadling, Leo; Capone, Stefania; Antrobus, Richard D.; Brown, Anthony; Richardson, Rachel; Newell, Evan W.; Halliday, John; Kelly, Christabel; Bowen, Dan; Fergusson, Joannah; Kurioka, Ayako; Ammendola, Virginia; Sorbo, Mariarosaria Del; Grazioli, Fabiana; Esposito, Maria Luisa; Siani, Loredana; Traboni, Cinzia; Hill, Adrian; Colloca, Stefano; Davis, Mark; Nicosia, Alfredo; Cortese, Riccardo; Folgori, Antonella; Klenerman, Paul; Barnes, Eleanor

    2015-01-01

    A protective vaccine against hepatitis C virus (HCV) remains an unmet clinical need. HCV infects millions of people worldwide and is a leading cause of liver cirrhosis and hepatocellular cancer. Animal challenge experiments, immunogenetics studies and assessment of host immunity during acute infection highlight the critical role that effective T-cell immunity plays in viral control. In this first-in-man study we have induced antiviral immunity with functional characteristics analogous to those associated with viral control in natural infection, and improved upon a vaccine based on adenoviral vectors alone. We assessed a heterologous prime-boost vaccination strategy based on a replicative defective simian adenoviral vector (ChAd3) and modified vaccinia Ankara (MVA) vector encoding the NS3, NS4, NS5A and NS5B proteins of HCV genotype-1b. Analysis employed single cell mass cytometry (CyTOF), and HLA class-I peptide tetramer technology in healthy human volunteers. We show that HCV specific T-cells induced by ChAd3 are optimally boosted with MVA, and generate very high levels of both CD8+ and CD4+ HCV specific T-cells targeting multiple HCV antigens. Sustained memory and effector T-cell populations are generated and T-cell memory evolved over time with improvement of quality (proliferation and polyfunctionality) following heterologous MVA boost. We have developed a HCV vaccine strategy, with durable, broad, sustained and balanced T-cell responses, characteristic of those associated with viral control, paving the way for the first efficacy studies of a prophylactic HCV vaccine. PMID:25378645

  18. Evaluation of the Efficacy, Potential for Vector Transmission, and Duration of Immunity of MP-12, an Attenuated Rift Valley Fever Virus Vaccine Candidate, in Sheep

    PubMed Central

    Bennett, Kristine E.; Drolet, Barbara S.; Lindsay, Robbin; Mecham, James O.; Reeves, Will K.; Weingartl, Hana M.; Wilson, William C.

    2015-01-01

    Rift Valley fever virus (RVFV) causes serious disease in ruminants and humans in Africa. In North America, there are susceptible ruminant hosts and competent mosquito vectors, yet there are no fully licensed animal vaccines for this arthropod-borne virus, should it be introduced. Studies in sheep and cattle have found the attenuated strain of RVFV, MP-12, to be both safe and efficacious based on early testing, and a 2-year conditional license for use in U.S. livestock has been issued. The purpose of this study was to further determine the vaccine's potential to infect mosquitoes, the duration of humoral immunity to 24 months postvaccination, and the ability to prevent disease and viremia from a virulent challenge. Vaccination experiments conducted in sheep found no evidence of a potential for vector transmission to 4 North American mosquito species. Neutralizing antibodies were elicited, with titers of >1:40 still present at 24 months postvaccination. Vaccinates were protected from clinical signs and detectable viremia after challenge with virulent virus, while control sheep had fever and high-titered viremia extending for 5 days. Antibodies to three viral proteins (nucleocapsid N, the N-terminal half of glycoprotein GN, and the nonstructural protein from the short segment NSs) were also detected to 24 months using competitive enzyme-linked immunosorbent assays. This study demonstrates that the MP-12 vaccine given as a single dose in sheep generates protective immunity to a virulent challenge with antibody duration of at least 2 years, with no evidence of a risk for vector transmission. PMID:26041042

  19. Generation of Recombinant Capripoxvirus Vectors for Vaccines and Gene Knockout Function Studies.

    PubMed

    Boshra, Hani; Cao, Jingxin; Babiuk, Shawn

    2016-01-01

    The ability to manipulate capripoxvirus through gene knockouts and gene insertions has become an increasingly valuable research tool in elucidating the function of individual genes of capripoxvirus, as well as in the development of capripoxvirus-based recombinant vaccines. The homologous recombination technique is used to generate capripoxvirus knockout viruses (KO), and is based on the targeting a particular viral gene of interest. This technique can also be used to insert a gene of interest. A protocol for the generation of a viral gene knockout is described. This technique involves the use of a plasmid which encodes the flanking sequences of the regions where the homologous recombination will occur, and will result in the insertion of an EGFP reporter gene for visualization of recombinant virus, as well as the E. coli gpt gene as a positive selection marker. If an additional gene is to be incorporated, this can be achieved by inserting a gene of interest for expression under a poxvirus promoter into the plasmid between the flanking regions for insertion. This chapter describes a protocol for generating such recombinant capripoxviruses.

  20. Listeria-vectored vaccine expressing the Mycobacterium tuberculosis 30 kDa major secretory protein via the constitutively active prfA* regulon boosts BCG efficacy against tuberculosis.

    PubMed

    Jia, Qingmei; Dillon, Barbara Jane; Masleša-Galić, Saša; Horwitz, Marcus A

    2017-06-19

    A potent vaccine against tuberculosis, one of the world's deadliest diseases, is needed to enhance the immunity of people worldwide, most of whom have been vaccinated with the partially effective BCG vaccine. Here we investigate novel live attenuated recombinant Listeria monocytogenes (rLm) vaccines expressing the Mycobacterium tuberculosis (Mtb) 30 kDa major secretory protein (r30/Ag85B) (rLm30) as heterologous booster vaccines in animals primed with BCG. Using three attenuated Lm vectors, rLm ΔactA (LmI), rLm ΔactA ΔinlB (LmII), and rLm ΔactA ΔinlBprfA* (LmIII), we constructed five rLm30 vaccine candidates expressing the r30 linked in-frame to the Lm Listeriolycin O signal sequence and driven by the hly promoter (h30) or linked in-frame to the ActA N-terminus and driven by the actA promoter (a30). All five rLm30 vaccines secreted r30 in broth and macrophages; while rLm expressing r30 via a constitutively active prfA* regulon (rLmIII/a30) expressed the greatest amount of r30 in broth culture, all five rLm vaccines expressed equivalent amounts of r30 in infected macrophages. In comparative studies, boosting BCG-immunized mice with rLmIII/a30 induced the strongest antigen-specific T-cell responses, including splenic and lung polyfunctional CD4+ T-cells expressing the three cytokines of interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), and interleukin-2 (IL-2) (P < 0.001) and splenic and lung CD8+ T-cells expressing IFN-γ (P < 0.0001). In mice and guinea pigs, rLmIII/a30 and rLmI/h30 vaccines were generally more potent booster vaccines than r30 in adjuvant and a recombinant adenovirus vaccine expressing r30. In a setting in which BCG alone was highly immunoprotective, boosting mice with rLmIII/a30, the most potent of the vaccines, significantly enhanced protection against aerosolized Mtb (P <0.01). Copyright © 2017 American Society for Microbiology.

  1. Vaccine strategies against Babesia bovis based on prime-boost immunizations in mice with modified vaccinia Ankara vector and recombinant proteins.

    PubMed

    Jaramillo Ortiz, José Manuel; Del Médico Zajac, María Paula; Zanetti, Flavia Adriana; Molinari, María Paula; Gravisaco, María José; Calamante, Gabriela; Wilkowsky, Silvina Elizabeth

    2014-08-06

    In this study, a recombinant modified vaccinia virus Ankara vector expressing a chimeric multi-antigen was obtained and evaluated as a candidate vaccine in homologous and heterologous prime-boost immunizations with a recombinant protein cocktail. The chimeric multi-antigen comprises immunodominant B and T cell regions of three Babesia bovis proteins. Humoral and cellular immune responses were evaluated in mice to compare the immunogenicity induced by different immunization schemes. The best vaccination scheme was achieved with a prime of protein cocktail and a boost with the recombinant virus. This scheme induced high level of specific IgG antibodies and secreted IFN and a high degree of activation of IFNγ(+) CD4(+) and CD8(+) specific T cells. This is the first report in which a novel vaccine candidate was constructed based on a rationally designed multi-antigen and evaluated in a prime-boost regime, optimizing the immune response necessary for protection against bovine babesiosis.

  2. Complete protection from papillomavirus challenge after a single vaccination with a vesicular stomatitis virus vector expressing high levels of L1 protein.

    PubMed

    Roberts, Anjeanette; Reuter, Jon D; Wilson, Jean H; Baldwin, Stuart; Rose, John K

    2004-03-01

    We generated an attenuated, recombinant vesicular stomatitis virus (VSV) expressing high levels of the cottontail rabbit papillomavirus (CRPV) L1 protein from an upstream site in the VSV genome. Rabbits vaccinated once with this VSV-L1 recombinant produced high levels of anti-L1 antibody and were completely protected against papilloma formation after challenge with CRPV. In contrast, animals vaccinated only once with a VSV vector expressing lower levels of L1 from a downstream site in the VSV genome generated lower levels of L1 antibody and demonstrated only incomplete protection from papilloma formation after challenge. We conclude that the level of L1 protein expression is critical in generating complete immunity with a single-dose vaccine.

  3. Reversal of papilloma growth in rabbits therapeutically vaccinated against E6 with naked DNA and/or vesicular stomatitis virus vectors

    PubMed Central

    Brandsma, Janet L.; Shlyankevich, Mark; Su, Yuhua; Zelterman, Daniel; Rose, John K.; Buonocore, Linda

    2009-01-01

    Persistent infection with high-risk human papillomaviruses (HPVs) is the greatest risk factor for the development of HPV-associated cancers. In this study rabbits bearing persistent and potentially malignant papillomas were used to test the efficacy of vaccination with a recombinant DNA and/or vesicular stomatitis virus (VSV) targeting the cottontail rabbit papillomavirus (CRPV) E6 protein. Immune responses were primed with either vector and boosted twice with the homologous or heterologous E6 vector. Over the course of 18 weeks, E6 vaccination reduced papilloma volumes to one third the volume in the controls, and the rabbits boosted with an heterologous vector tended to mount stronger responses. Small and medium-sized papillomas responded significantly but only slightly better than large papillomas. Finally the initial papilloma burden per rabbit, ranging from <100 mm3 to >1000 mm3, was not prognostic of antitumor efficacy. In summary both E6 vaccines elicited significant therapeutic immunity, and their sequential use tended to be advantageous. PMID:19615481

  4. [Creation of DNA vaccine vector based on codon-optimized gene of rabies virus glycoprotein (G protein) with consensus amino acid sequence].

    PubMed

    Starodubova, E S; Kuzmenko, Y V; Latanova, A A; Preobrazhenskaya, O V; Karpov, V L

    2016-01-01

    An optimized design of the rabies virus glycoprotein (G protein) for use within DNA vaccines has been suggested. The design represents a territorially adapted antigen constructed taking into account glycoprotein amino acid sequences of the rabies viruses registered in the Russian Federation and the vaccine Vnukovo-32 strain. Based on the created consensus amino acid sequence, the nucleotide codon-optimized sequence of this modified glycoprotein was obtained and cloned into the pVAX1 plasmid (a vector of the last generation used in the creation of DNA vaccines). A twofold increase in this gene expression compared to the expression of the Vnukovo-32 strain viral glycoprotein gene in a similar vector was registered in the transfected cell culture. It has been demonstrated that the accumulation of modified G protein exceeds the number of the control protein synthesized using the plasmid with the Vnukovo-32 strain viral glycoprotein gene by 20 times. Thus, the obtained modified rabies virus glycoprotein can be considered to be a promising DNA vaccine antigen.

  5. Infection of nonhost species dendritic cells in vitro with an attenuated myxoma virus induces gene expression that predicts its efficacy as a vaccine vector.

    PubMed

    Top, S; Foulon, E; Pignolet, B; Deplanche, M; Caubet, C; Tasca, C; Bertagnoli, S; Meyer, G; Foucras, G

    2011-12-01

    Recombinant myxoma virus (MYXV) can be produced without a loss of infectivity, and its highly specific host range makes it an ideal vaccine vector candidate, although careful examination of its interaction with the immune system is necessary. Similar to rabbit bone marrow-derived dendritic cells (BM-DCs), ovine dendritic cells can be infected by SG33, a MYXV vaccine strain, and support recombinant antigen expression. The frequency of infected cells in the nonhost was lower and the virus cycle was abortive in these cell types. Among BM-DC subpopulations, Langerhans cell-like DCs were preferentially infected at low multiplicities of infection. Interestingly, ovine BM-DCs remained susceptible to MYXV after maturation, although apoptosis occurred shortly after infection as a function of the virus titer. When gene expression was assessed in infected BM-DC cultures, type I interferon (IFN)-related and inflammatory genes were strongly upregulated. DC gene expression profiles were compared with the profiles produced by other poxviruses in interaction with DCs, but very few commonalities were found, although genes that were previously shown to predict vaccine efficacy were present. Collectively, these data support the idea that MYXV permits efficient priming of adaptive immune responses and should be considered a promising vaccine vector along with other poxviruses.

  6. Vaccination With Heterologous HIV-1 Envelope Sequences and Heterologous Adenovirus Vectors Increases T-Cell Responses to Conserved Regions: HVTN 083

    PubMed Central

    Walsh, Stephen R.; Moodie, Zoe; Fiore-Gartland, Andrew J.; Morgan, Cecilia; Wilck, Marissa B.; Hammer, Scott M.; Buchbinder, Susan P.; Kalams, Spyros A.; Goepfert, Paul A.; Mulligan, Mark J.; Keefer, Michael C.; Baden, Lindsey R.; Swann, Edith M.; Grant, Shannon; Ahmed, Hasan; Li, Fusheng; Hertz, Tomer; Self, Steven G.; Friedrich, David; Frahm, Nicole; Liao, Hua-Xin; Montefiori, David C.; Tomaras, Georgia D.; McElrath, M. Juliana; Hural, John; Graham, Barney S.; Jin, Xia

    2016-01-01

    Background. Increasing the breadth of human immunodeficiency virus type 1 (HIV-1) vaccine-elicited immune responses or targeting conserved regions may improve coverage of circulating strains. HIV Vaccine Trials Network 083 tested whether cellular immune responses with these features are induced by prime-boost strategies, using heterologous vectors, heterologous inserts, or a combination of both. Methods. A total of 180 participants were randomly assigned to receive combinations of adenovirus vectors (Ad5 or Ad35) and HIV-1 envelope (Env) gene inserts (clade A or B) in a prime-boost regimen. Results. T-cell responses to heterologous and homologous insert regimens targeted a similar number of epitopes (ratio of means, 1.0; 95% confidence interval [CI], .6–1.6; P = .91), but heterologous insert regimens induced significantly more epitopes that were shared between EnvA and EnvB than homologous insert regimens (ratio of means, 2.7; 95% CI, 1.2–5.7; P = .01). Participants in the heterologous versus homologous insert groups had T-cell responses that targeted epitopes with greater evolutionary conservation (mean entropy [±SD], 0.32 ± 0.1 bits; P = .003), and epitopes recognized by responders provided higher coverage (49%; P = .035). Heterologous vector regimens had higher numbers of total, EnvA, and EnvB epitopes than homologous vector regimens (P = .02, .044, and .045, respectively). Conclusions. These data demonstrate that vaccination with heterologous insert prime boosting increased T-cell responses to shared epitopes, while heterologous vector prime boosting increased the number of T-cell epitopes recognized. Clinical Trials Registration. NCT01095224. PMID:26475930

  7. Long-Term Immunological Memory Induced by Recombinant Oral Salmonella Vaccine Vectors

    PubMed Central

    Kohler, James J.; Pathangey, Latha; Hasona, Adnan; Progulske-Fox, Ann; Brown, Thomas A.

    2000-01-01

    We have previously shown that Salmonella enterica serovar Typhimurium expressing the hagB hemagglutinin gene from Porphyromonas gingivalis can induce primary and recall immune responses in serum and secretions in mice; however, the longevity of memory induced by oral Salmonella carriers has not been adequately demonstrated. In this study, we examined the capacity of mice to mount a recall response 52 weeks after primary immunization. Recall responses were seen in serum immunoglobulin G (IgG) and IgA following boosting at week 52, and in most cases, they were equal to or greater than the primary responses. Significant mucosal IgA recall responses in saliva and vaginal wash were also detected following boosting at week 52. In addition, there was a considerable residual response in secretions at week 51, prior to boosting. These results indicate that oral Salmonella vectors can induce long-term memory to recombinant HagB and are particularly effective at inducing long-lasting mucosal responses as well as at inducing the capacity for mucosal recall responses. PMID:10858264

  8. Intranasal Mucosal Boosting with an Adenovirus-Vectored Vaccine Markedly Enhances the Protection of BCG-Primed Guinea Pigs against Pulmonary Tuberculosis

    PubMed Central

    Xing, Zhou; McFarland, Christine T.; Sallenave, Jean-Michel; Izzo, Angelo; Wang, Jun; McMurray, David N.

    2009-01-01

    Background Recombinant adenovirus-vectored (Ad) tuberculosis (TB) vaccine platform has demonstrated great potential to be used either as a stand-alone or a boost vaccine in murine models. However, Ad TB vaccine remains to be evaluated in a more relevant and sensitive guinea pig model of pulmonary TB. Many vaccine candidates shown to be effective in murine models have subsequently failed to pass the test in guinea pig models. Methods and Findings Specific pathogen-free guinea pigs were immunized with BCG, AdAg85A intranasally (i.n), AdAg85A intramuscularly (i.m), BCG boosted with AdAg85A i.n, BCG boosted with AdAg85A i.m, or treated only with saline. The animals were then infected by a low-dose aerosol of M. tuberculosis (M.tb). At the specified times, the animals were sacrificed and the levels of infection in the lung and spleen were assessed. In separate studies, the long-term disease outcome of infected animals was monitored until the termination of this study. Immunization with Ad vaccine alone had minimal beneficial effects. Immunization with BCG alone and BCG prime-Ad vaccine boost regimens significantly reduced the level of M.tb infection in the tissues to a similar extent. However, while BCG alone prolonged the survival of infected guinea pigs, the majority of BCG-immunized animals succumbed by 53 weeks post-M.tb challenge. In contrast, intranasal or intramuscular Ad vaccine boosting of BCG-primed animals markedly improved the survival rate with 60% of BCG/Ad i.n- and 40% of BCG/Ad i.m-immunized guinea pigs still surviving by 74 weeks post-aerosol challenge. Conclusions Boosting, particularly via the intranasal mucosal route, with AdAg85A vaccine is able to significantly enhance the long-term survival of BCG-primed guinea pigs following pulmonary M.tb challenge. Our results thus support further evaluation of this viral-vectored TB vaccine in clinical trials. PMID:19516906

  9. DENGUE VACCINES.

    PubMed

    Thisyakorn, Usa; Thisyakorn, Chule

    2015-01-01

    The uniqueness of the dengue viruses (DENVs) and the spectrum of disease resulting from infection have made dengue vaccine development difficult. Several vaccine candidates are currently being evaluated in clinical studies. The candidate currently at the most advanced clinical development stage, a live-attenuated tetravalent vaccine based on the chimeric yellow fever-dengue virus (CYD-TDV), has progressed to Phase 3 efficacy studies. Several other live-attenuated vaccines, as well as subunit, DNA, and purified inactivated vaccine candidates are at earlier stages of clinical development. Additional technological approaches, such as virus-vectored and Virus-Like Particles (VLP)-based vaccines are under evaluation in preclinical studies.

  10. Molecular Characterization of Heterologous HIV-1gp120 Gene Expression Disruption in Mycobacterium bovis BCG Host Strain: A Critical Issue for Engineering Mycobacterial Based-Vaccine Vectors

    PubMed Central

    Joseph, Joan; Fernández-Lloris, Raquel; Pezzat, Elías; Saubi, Narcís; Cardona, Pere-Joan; Mothe, Beatriz; Gatell, Josep Maria

    2010-01-01

    Mycobacterium bovis Bacillus Calmette-Guérin (BCG) as a live vector of recombinant bacterial vaccine is a promising system to be used. In this study, we evaluate the disrupted expression of heterologous HIV-1gp120 gene in BCG Pasteur host strain using replicative vectors pMV261 and pJH222. pJH222 carries a lysine complementing gene in BCG lysine auxotrophs. The HIV-1 gp120 gene expression was regulated by BCG hsp60 promoter (in plasmid pMV261) and Mycobacteria spp. α-antigen promoter (in plasmid pJH222). Among 14 rBCG:HIV-1gp120 (pMV261) colonies screened, 12 showed a partial deletion and two showed a complete deletion. However, deletion was not observed in all 10 rBCG:HIV-1gp120 (pJH222) colonies screened. In this study, we demonstrated that E. coli/Mycobacterial expression vectors bearing a weak promoter and lysine complementing gene in a recombinant lysine auxotroph of BCG could prevent genetic rearrangements and disruption of HIV 1gp120 gene expression, a key issue for engineering Mycobacterial based vaccine vectors. PMID:20617151

  11. Surface displaying of swine IgG1 Fc enhances baculovirus-vectored vaccine efficacy by facilitating viral complement escape and mammalian cell transduction.

    PubMed

    Liu, Zehui; Liu, Yangkun; Zhang, Yuanyuan; Yang, Yajuan; Ren, Jingjing; Zhang, Xiaoying; Du, Enqi

    2017-05-12

    Baculovirus-mediated gene transfer has been developed as a vaccine design strategy against a number of diseases without apparent viral replication. However, it has been hampered by complement-dependent inactivation, thus hindering the in vivo application of baculovirus. A variety of approaches have been exploited to bypass the complement system in the serum. In this study, we constructed and screened a series of baculovirus vectors displaying complement interfering factors, of which a baculovirus vector displaying swine IgG1 Fc (pFc) showed the highest complement antagonism (75.6%). Flow cytometry analysis of transduced cells demonstrated that the baculovirus display of pFc had a significant increase in transduction efficiency and transgene expression of reporter genes. On this basis, a VSV-G-pseudotyped with swine IgG1 Fc surface displayed baculovirus vector was developed to express the classical swine fever virus (CSFV) E2 gene. The translational enhancers Syn21 and P10UTR were incorporated to improve the antigen expression. The E2 gene was efficiently expressed in both insect and mammalian cells. Pigs immunized with this recombinant baculovirus developed high levels of E2-specific antibody, CSFV-specific neutralizing antibody and IFN-γ-secreting cellular immune responses. These results demonstrate that the strategy of surface-displaying swine IgG1 Fc has a great potential to improve the efficiency of baculovirus-vectored vaccine for CSFV and other swine pathogens.

  12. Highly-Immunogenic Virally-Vectored T-cell Vaccines Cannot Overcome Subversion of the T-cell Response by HCV during Chronic Infection.

    PubMed

    Swadling, Leo; Halliday, John; Kelly, Christabel; Brown, Anthony; Capone, Stefania; Ansari, M Azim; Bonsall, David; Richardson, Rachel; Hartnell, Felicity; Collier, Jane; Ammendola, Virginia; Del Sorbo, Mariarosaria; Von Delft, Annette; Traboni, Cinzia; Hill, Adrian V S; Colloca, Stefano; Nicosia, Alfredo; Cortese, Riccardo; Klenerman, Paul; Folgori, Antonella; Barnes, Eleanor

    2016-08-02

    An effective therapeutic vaccine for the treatment of chronic hepatitis C virus (HCV) infection, as an adjunct to newly developed directly-acting antivirals (DAA), or for the prevention of reinfection, would significantly reduce the global burden of disease associated with chronic HCV infection. A recombinant chimpanzee adenoviral (ChAd3) vector and a modified vaccinia Ankara (MVA), encoding the non-structural proteins of HCV (NSmut), used in a heterologous prime/boost regimen induced multi-specific, high-magnitude, durable HCV-specific CD4+ and CD8+ T-cell responses in healthy volunteers, and was more immunogenic than a heterologous Ad regimen. We now assess the immunogenicity of this vaccine regimen in HCV infected patients (including patients with a low viral load suppressed with interferon/ribavirin therapy), determine T-cell cross-reactivity to endogenous virus, and compare immunogenicity with that observed previously in both healthy volunteers and in HCV infected patients vaccinated with the heterologous Ad regimen. Vaccination of HCV infected patients with ChAd3-NSmut/MVA-NSmut was well tolerated. Vaccine-induced HCV-specific T-cell responses were detected in 8/12 patients; however, CD4+ T-cell responses were rarely detected, and the overall magnitude of HCV-specific T-cell responses was markedly reduced when compared to vaccinated healthy volunteers. Furthermore, HCV-specific cells had a distinct partially-functional phenotype (lower expression of activation markers, granzyme B, and TNFα production, weaker in vitro proliferation, and higher Tim3 expression, with comparable Tbet and Eomes expression) compared to healthy volunteers. Robust anti-vector T-cells and antibodies were induced, showing that there is no global defect in immunity. The level of viremia at the time of vaccination did not correlate with the magnitude of the vaccine-induced T-cell response. Full-length, next-generation sequencing of the circulating virus demonstrated that T-cells were

  13. Highly-Immunogenic Virally-Vectored T-cell Vaccines Cannot Overcome Subversion of the T-cell Response by HCV during Chronic Infection

    PubMed Central

    Swadling, Leo; Halliday, John; Kelly, Christabel; Brown, Anthony; Capone, Stefania; Ansari, M. Azim; Bonsall, David; Richardson, Rachel; Hartnell, Felicity; Collier, Jane; Ammendola, Virginia; Del Sorbo, Mariarosaria; Von Delft, Annette; Traboni, Cinzia; Hill, Adrian V. S.; Colloca, Stefano; Nicosia, Alfredo; Cortese, Riccardo; Klenerman, Paul; Folgori, Antonella; Barnes, Eleanor

    2016-01-01

    An effective therapeutic vaccine for the treatment of chronic hepatitis C virus (HCV) infection, as an adjunct to newly developed directly-acting antivirals (DAA), or for the prevention of reinfection, would significantly reduce the global burden of disease associated with chronic HCV infection. A recombinant chimpanzee adenoviral (ChAd3) vector and a modified vaccinia Ankara (MVA), encoding the non-structural proteins of HCV (NSmut), used in a heterologous prime/boost regimen induced multi-specific, high-magnitude, durable HCV-specific CD4+ and CD8+ T-cell responses in healthy volunteers, and was more immunogenic than a heterologous Ad regimen. We now assess the immunogenicity of this vaccine regimen in HCV infected patients (including patients with a low viral load suppressed with interferon/ribavirin therapy), determine T-cell cross-reactivity to endogenous virus, and compare immunogenicity with that observed previously in both healthy volunteers and in HCV infected patients vaccinated with the heterologous Ad regimen. Vaccination of HCV infected patients with ChAd3-NSmut/MVA-NSmut was well tolerated. Vaccine-induced HCV-specific T-cell responses were detected in 8/12 patients; however, CD4+ T-cell responses were rarely detected, and the overall magnitude of HCV-specific T-cell responses was markedly reduced when compared to vaccinated healthy volunteers. Furthermore, HCV-specific cells had a distinct partially-functional phenotype (lower expression of activation markers, granzyme B, and TNFα production, weaker in vitro proliferation, and higher Tim3 expression, with comparable Tbet and Eomes expression) compared to healthy volunteers. Robust anti-vector T-cells and antibodies were induced, showing that there is no global defect in immunity. The level of viremia at the time of vaccination did not correlate with the magnitude of the vaccine-induced T-cell response. Full-length, next-generation sequencing of the circulating virus demonstrated that T-cells were

  14. A Prime-Boost Vaccination Strategy in Cattle to Prevent Foot-and-Mouth Disease Using a “Single-Cycle” Alphavirus Vector and Empty Capsid Particles

    PubMed Central

    Gullberg, Maria; Lohse, Louise; Bøtner, Anette; McInerney, Gerald M.; Burman, Alison; Jackson, Terry; Polacek, Charlotta

    2016-01-01

    Foot-and-mouth disease (FMD) remains one of the most economically important infectious diseases of production animals globally. Vaccination can successfully control this disease, however, current vaccines are imperfect. They are made using chemically inactivated FMD virus (FMDV) that is produced in large-scale mammalian cell culture under high containment conditions. Here, we have expressed the FMDV capsid protein precursor (P1-2A) of strain O1 Manisa alone or with the FMDV 3C protease (3Cpro) using a “single cycle” packaged alphavirus self-replicating RNA based on Semliki Forest virus (SFV). When the FMDV P1-2A was expressed with 3Cpro then processing of the FMDV capsid precursor protein is observed within cells and the proteins assemble into empty capsid particles. The products interact with anti-FMDV antibodies in an ELISA and bind to the integrin αvβ6 (a cellular receptor for FMDV). In cattle vaccinated with these rSFV-FMDV vectors alone, anti-FMDV antibodies were elicited but the immune response was insufficient to give protection against FMDV challenge. However, the prior vaccination with these vectors resulted in a much stronger immune response against FMDV post-challenge and the viremia observed was decreased in level and duration. In subsequent experiments, cattle were sequentially vaccinated with a rSFV-FMDV followed by recombinant FMDV empty capsid particles, or vice versa, prior to challenge. Animals given a primary vaccination with the rSFV-FMDV vector and then boosted with FMDV empty capsids showed a strong anti-FMDV antibody response prior to challenge, they were protected against disease and no FMDV RNA was detected in their sera post-challenge. Initial inoculation with empty capsids followed by the rSFV-FMDV was much less effective at combating the FMDV challenge and a large post-challenge boost to the level of anti-FMDV antibodies was observed. This prime-boost system, using reagents that can be generated outside of high

  15. A Prime-Boost Vaccination Strategy in Cattle to Prevent Foot-and-Mouth Disease Using a "Single-Cycle" Alphavirus Vector and Empty Capsid Particles.

    PubMed

    Gullberg, Maria; Lohse, Louise; Bøtner, Anette; McInerney, Gerald M; Burman, Alison; Jackson, Terry; Polacek, Charlotta; Belsham, Graham J

    2016-01-01

    Foot-and-mouth disease (FMD) remains one of the most economically important infectious diseases of production animals globally. Vaccination can successfully control this disease, however, current vaccines are imperfect. They are made using chemically inactivated FMD virus (FMDV) that is produced in large-scale mammalian cell culture under high containment conditions. Here, we have expressed the FMDV capsid protein precursor (P1-2A) of strain O1 Manisa alone or with the FMDV 3C protease (3Cpro) using a "single cycle" packaged alphavirus self-replicating RNA based on Semliki Forest virus (SFV). When the FMDV P1-2A was expressed with 3Cpro then processing of the FMDV capsid precursor protein is observed within cells and the proteins assemble into empty capsid particles. The products interact with anti-FMDV antibodies in an ELISA and bind to the integrin αvβ6 (a cellular receptor for FMDV). In cattle vaccinated with these rSFV-FMDV vectors alone, anti-FMDV antibodies were elicited but the immune response was insufficient to give protection against FMDV challenge. However, the prior vaccination with these vectors resulted in a much stronger immune response against FMDV post-challenge and the viremia observed was decreased in level and duration. In subsequent experiments, cattle were sequentially vaccinated with a rSFV-FMDV followed by recombinant FMDV empty capsid particles, or vice versa, prior to challenge. Animals given a primary vaccination with the rSFV-FMDV vector and then boosted with FMDV empty capsids showed a strong anti-FMDV antibody response prior to challenge, they were protected against disease and no FMDV RNA was detected in their sera post-challenge. Initial inoculation with empty capsids followed by the rSFV-FMDV was much less effective at combating the FMDV challenge and a large post-challenge boost to the level of anti-FMDV antibodies was observed. This prime-boost system, using reagents that can be generated outside of high-containment facilities

  16. Evaluation of Measles Vaccine Virus as a Vector to Deliver Respiratory Syncytial Virus Fusion Protein or Epstein-Barr Virus Glycoprotein gp350

    PubMed Central

    Mok, Hoyin; Cheng, Xing; Xu, Qi; Zengel, James R; Parhy, Bandita; Zhao, Jackie; Wang, C. Kathy; Jin, Hong

    2012-01-01

    Live attenuated recombinant measles vaccine virus (MV) Edmonston-Zagreb (EZ) strain was evaluated as a viral vector to express the ectodomains of fusion protein of respiratory syncytial virus (RSV F) or glycoprotein 350 of Epstein-Barr virus (EBV gp350) as candidate vaccines for prophylaxis of RSV and EBV. The glycoprotein gene was inserted at the 1st or the 3rd position of the measles virus genome and the recombinant viruses were generated. Insertion of the foreign gene at the 3rd position had a minimal impact on viral replication in vitro. RSV F or EBV gp350 protein was secreted from infected cells. In cotton rats, EZ-RSV F and EZ-EBV gp350 induced MV- and insert-specific antibody responses. In addition, both vaccines also induced insert specific interferon gamma (IFN-γ) secreting T cell response. EZ-RSV F protected cotton rats from pulmonary replication of RSV A2 challenge infection. In rhesus macaques, although both EZ-RSV F and EZ-EBV gp350 induced MV specific neutralizing antibody responses, only RSV F specific antibody response was detected. Thus, the immunogenicity of the foreign antigens delivered by measles vaccine virus is dependent on the nature of the insert and the animal models used for vaccine evaluation. PMID:22383906

  17. Evaluation of Measles Vaccine Virus as a Vector to Deliver Respiratory Syncytial Virus Fusion Protein or Epstein-Barr Virus Glycoprotein gp350.

    PubMed

    Mok, Hoyin; Cheng, Xing; Xu, Qi; Zengel, James R; Parhy, Bandita; Zhao, Jackie; Wang, C Kathy; Jin, Hong

    2012-01-01

    Live attenuated recombinant measles vaccine virus (MV) Edmonston-Zagreb (EZ) strain was evaluated as a viral vector to express the ectodomains of fusion protein of respiratory syncytial virus (RSV F) or glycoprotein 350 of Epstein-Barr virus (EBV gp350) as candidate vaccines for prophylaxis of RSV and EBV. The glycoprotein gene was inserted at the 1(st) or the 3(rd) position of the measles virus genome and the recombinant viruses were generated. Insertion of the foreign gene at the 3(rd) position had a minimal impact on viral replication in vitro. RSV F or EBV gp350 protein was secreted from infected cells. In cotton rats, EZ-RSV F and EZ-EBV gp350 induced MV- and insert-specific antibody responses. In addition, both vaccines also induced insert specific interferon gamma (IFN-γ) secreting T cell response. EZ-RSV F protected cotton rats from pulmonary replication of RSV A2 challenge infection. In rhesus macaques, although both EZ-RSV F and EZ-EBV gp350 induced MV specific neutralizing antibody responses, only RSV F specific antibody response was detected. Thus, the immunogenicity of the foreign antigens delivered by measles vaccine virus is dependent on the nature of the insert and the animal models used for vaccine evaluation.

  18. Novel replication-incompetent vector derived from adenovirus type 11 (Ad11) for vaccination and gene therapy: low seroprevalence and non-cross-reactivity with Ad5.

    PubMed

    Holterman, Lennart; Vogels, Ronald; van der Vlugt, Remko; Sieuwerts, Martijn; Grimbergen, Jos; Kaspers, Jorn; Geelen, Eric; van der Helm, Esmeralda; Lemckert, Angelique; Gillissen, Gert; Verhaagh, Sandra; Custers, Jerome; Zuijdgeest, David; Berkhout, Ben; Bakker, Margreet; Quax, Paul; Goudsmit, Jaap; Havenga, Menzo

    2004-12-01

    A novel plasmid-based adenovirus vector system that enables manufacturing of replication-incompetent (DeltaE1) adenovirus type 11 (Ad11)-based vectors is described. Ad11 vectors are produced on PER.C6/55K cells yielding high-titer vector batches after purification. Ad11 seroprevalence proves to be significantly lower than that of Ad5, and neutralizing antibody titers against Ad11 are low. Ad11 seroprevalence among human immunodeficiency virus-positive (HIV(+)) individuals is as low as that among HIV(-) individuals, independent of the level of immune suppression. The low level of coinciding seroprevalence between Ad11 and Ad35 in addition to a lack of correlation between high neutralizing antibody titers towards either adenovirus strongly suggest that the limited humoral cross-reactive immunity between these two highly related B viruses appears not to preclude the use of both vectors in the same individual. Ad11 transduces primary cells including smooth muscle cells, synoviocytes, and dendritic cells and cardiovascular tissues with higher efficiency than Ad5. Ad11 and Ad35 appear to have a similar tropism as judged by green fluorescent protein expression levels determined by using a panel of cancer cell lines. In addition, Ad5 preimmunization did not significantly affect Ad11-mediated transduction in C57BL/6 mice. We therefore conclude that the Ad11-based vector represents a novel and useful candidate gene transfer vehicle for vaccination and gene therapy.

  19. Assessment of immune interference, antagonism, and diversion following human immunization with biallelic blood-stage malaria viral-vectored vaccines and controlled malaria infection.

    PubMed

    Elias, Sean C; Collins, Katharine A; Halstead, Fenella D; Choudhary, Prateek; Bliss, Carly M; Ewer, Katie J; Sheehy, Susanne H; Duncan, Christopher J A; Biswas, Sumi; Hill, Adrian V S; Draper, Simon J

    2013-02-01

    Overcoming antigenic variation is one of the major challenges in the development of an effective vaccine against Plasmodium falciparum, a causative agent of human malaria. Inclusion of multiple Ag variants in subunit vaccine candidates is one strategy that has aimed to overcome this problem for the leading blood-stage malaria vaccine targets, that is, merozoite surface protein 1 (MSP1) and apical membrane Ag 1 (AMA1). However, previous studies, utilizing malaria Ags, have concluded that inclusion of multiple allelic variants, encoding altered peptide ligands, in such a vaccine may be detrimental to both the priming and in vivo restimulation of Ag-experienced T cells. In this study, we analyze the T cell responses to two alleles of MSP1 and AMA1 induced by vaccination of malaria-naive adult volunteers with bivalent viral-vectored vaccine candidates. We show a significant bias to the 3D7/MAD20 allele compared with the Wellcome allele for the 33 kDa region of MSP1, but not for the 19 kDa fragment or the AMA1 Ag. Although this bias could be caused by "immune interference" at priming, the data do not support a significant role for "immune antagonism" during memory T cell restimulation, despite observation of the latter at a minimal epitope level in vitro. A lack of class I HLA epitopes in the Wellcome allele that are recognized by vaccinated volunteers may in fact contribute to the observed bias. We also show that controlled infection with 3D7 strain P. falciparum parasites neither boosts existing 3D7-specific T cell responses nor appears to "immune divert" cellular responses toward the Wellcome allele.

  20. Multiagent vaccines vectored by Venezuelan equine encephalitis virus replicon elicits immune responses to Marburg virus and protection against anthrax and botulinum neurotoxin in mice.

    PubMed

    Lee, John S; Groebner, Jennifer L; Hadjipanayis, Angela G; Negley, Diane L; Schmaljohn, Alan L; Welkos, Susan L; Smith, Leonard A; Smith, Jonathan F

    2006-11-17

    The development of multiagent vaccines offers the advantage of eliciting protection against multiple diseases with minimal inoculations over a shorter time span. We report here the results of using formulations of individual Venezuelan equine encephalitis (VEE) virus replicon-vectored vaccines against a bacterial disease, anthrax; a viral disease, Marburg fever; and against a toxin-mediated disease, botulism. The individual VEE replicon particles (VRP) expressed mature 83-kDa protective antigen (MAT-PA) from Bacillus anthracis, the glycoprotein (GP) from Marburg virus (MBGV), or the H(C) fragment from botulinum neurotoxin (BoNT H(C)). CBA/J mice inoculated with a mixture of VRP expressing BoNT H(C) serotype C (BoNT/C H(C)) and MAT-PA were 80% protected from a B. anthracis (Sterne strain) challenge and then 100% protected from a sequential BoNT/C challenge. Swiss mice inoculated with individual VRP or with mixtures of VRP vaccines expressing BoNT H(C) serotype A (BoNT/A H(C)), MAT-PA, and MBGV-GP produced antibody responses specific to the corresponding replicon-expressed protein. Combination of the different VRP vaccines did not diminish the antibody responses measured for Swiss mice inoculated with formulations of two or three VRP vaccines as compared to mice that received only one VRP vaccine. Swiss mice inoculated with VRP expressing BoNT/A H(C) alone or in combination with VRP expressing MAT-PA and MBGV GP, were completely protected from a BoNT/A challenge. These studies demonstrate the utility of combining individual VRP vaccines into multiagent formulations for eliciting protective immune responses to various types of diseases.

  1. Effects of the fusion design and immunization route on the immunogenicity of Ag85A-Mtb32 in adenoviral vectored tuberculosis vaccine

    PubMed Central

    Zhang, Yiling; Feng, Liqiang; Li, Liang; Wang, Dimin; Li, Chufang; Sun, Caijun; Li, Pingchao; Zheng, Xuehua; Liu, Yichu; Yang, Wei; Niu, Xuefeng; Zhong, Nanshan; Chen, Ling

    2015-01-01

    Vaccines containing multiple antigens may induce broader immune responses and provide better protection against Mycobacterium tuberculosis (Mtb) infection as compared to a single antigen. However, strategies for incorporating multiple antigens into a single vector and the immunization routes may affect their immunogenicity. In this study, we utilized recombinant adenovirus type 5 (rAd5) as a model vaccine vector, and Ag85A (Rv3804c) and Mtb32 (Rv0125) as model antigens, to comparatively evaluate the influence of codon usage optimization, signal sequence, fusion linkers, and immunization routes on the immunogenicity of tuberculosis (TB) vaccine containing multiple antigens in C57BL/6 mice. We showed that codon-optimized Ag85A and Mtb32 fused with a GSG linker induced the strongest systemic and pulmonary cell-mediated immune (CMI) responses. Strong CMI responses were characterized by the generation of a robust IFN-γ ELISPOT response as well as antigen-specific CD4+ T and CD8+ T cells, which secreted mono-, dual-, or multiple cytokines. We also found that subcutaneous (SC) and intranasal (IN)/oral immunization with this candidate vaccine exhibited the strongest boosting effects for Mycobacterium bovis bacille Calmette-Guérin (BCG)-primed systemic and pulmonary CMI responses, respectively. Our results supported that codon optimized Ag85A and Mtb32 fused with a proper linker and immunized through SC and IN/oral routes can generate the strongest systemic and pulmonary CMI responses in BCG-primed mice, which may be particularly important for the design of TB vaccines containing multiple antigens. PMID:26076321

  2. Effects of the fusion design and immunization route on the immunogenicity of Ag85A-Mtb32 in adenoviral vectored tuberculosis vaccine.

    PubMed

    Zhang, Yiling; Feng, Liqiang; Li, Liang; Wang, Dimin; Li, Chufang; Sun, Caijun; Li, Pingchao; Zheng, Xuehua; Liu, Yichu; Yang, Wei; Niu, Xuefeng; Zhong, Nanshan; Chen, Ling

    2015-01-01

    Vaccines containing multiple antigens may induce broader immune responses and provide better protection against Mycobacterium tuberculosis (Mtb) infection as compared to a single antigen. However, strategies for incorporating multiple antigens into a single vector and the immunization routes may affect their immunogenicity. In this study, we utilized recombinant adenovirus type 5 (rAd5) as a model vaccine vector, and Ag85A (Rv3804c) and Mtb32 (Rv0125) as model antigens, to comparatively evaluate the influence of codon usage optimization, signal sequence, fusion linkers, and immunization routes on the immunogenicity of tuberculosis (TB) vaccine containing multiple antigens in C57BL/6 mice. We showed that codon-optimized Ag85A and Mtb32 fused with a GSG linker induced the strongest systemic and pulmonary cell-mediated immune (CMI) responses. Strong CMI responses were characterized by the generation of a robust IFN-γ ELISPOT response as well as antigen-specific CD4(+) T and CD8(+) T cells, which secreted mono-, dual-, or multiple cytokines. We also found that subcutaneous (SC) and intranasal (IN)/oral immunization with this candidate vaccine exhibited the strongest boosting effects for Mycobacterium bovis bacille Calmette-Guérin (BCG)-primed systemic and pulmonary CMI responses, respectively. Our results supported that codon optimized Ag85A and Mtb32 fused with a proper linker and immunized through SC and IN/oral routes can generate the strongest systemic and pulmonary CMI responses in BCG-primed mice, which may be particularly important for the design of TB vaccines containing multiple antigens.

  3. Improving Mycobacterium bovis Bacillus Calmette-Guèrin as a Vaccine Delivery Vector for Viral Antigens by Incorporation of Glycolipid Activators of NKT Cells

    PubMed Central

    Kharkwal, Shalu S.; Carreño, Leandro J.; Johnson, Alison J.; Kunnath-Velayudhan, Shajo; Liu, Zheng; Bittman, Robert; Jervis, Peter J.; Cox, Liam R.; Besra, Gurdyal S.; Wen, Xiangshu; Yuan, Weiming; Tsuji, Moriya; Li, Xiangming; Ho, David D.; Chan, John; Lee, Sunhee; Frothingham, Richard; Haynes, Barton F.; Panas, Michael W.; Gillard, Geoffrey O.; Sixsmith, Jaimie D.; Korioth-Schmitz, Birgit; Schmitz, Joern E.; Larsen, Michelle H.; Jacobs, William R.; Porcelli, Steven A.

    2014-01-01

    Recombinant Mycobacterium bovis bacillus Calmette-Guèrin (rBCG) has been explored as a vector for vaccines against HIV because of its ability to induce long lasting humoral and cell mediated immune responses. To maximize the potential for rBCG vaccines to induce effective immunity against HIV, various strategies are being employed to improve its ability to prime CD8+ T cells, which play an important role in the control of HIV infections. In this study we adopted a previously described approach of incorporating glycolipids that activate CD1d-restricted natural killer T (NKT) cells to enhance priming of CD8+ T cells by rBCG strains expressing an SIV Gag antigen (rBCG-SIV gag). We found that the incorporation of the synthetic NKT activating glycolipid α-galactosylceramide (α-GC) into rBCG-SIV gag significantly enhanced CD8+ T cell responses against an immunodominant Gag epitope, compared to responses primed by unmodified rBCG-SIV gag. The abilities of structural analogues of α-GC to enhance CD8+ T cell responses to rBCG were compared in both wild type and partially humanized mice that express human CD1d molecules in place of mouse CD1d. These studies identified an α-GC analogue known as 7DW8-5, which has previously been used successfully as an adjuvant in non-human primates, as a promising compound for enhancing immunogenicity of antigens delivered by rBCG.vectors. Our findings support the incorporation of synthetic glycolipid activators of NKT cells as a novel approach to enhance the immunogenicity of rBCG-vectored antigens for induction of CD8+ T cell responses. The glycolipid adjuvant 7DW8-5 may be a promising candidate for advancing to non-human primate and human clinical studies for the development of HIV vaccines based on rBCG vectors. PMID:25255287

  4. Single dose adenovirus vectored vaccine induces a potent and long-lasting immune response against rabbit hemorrhagic disease virus after parenteral or mucosal administration.

    PubMed

    Fernández, Erlinda; Toledo, Jorge R; Chiong, Maylin; Parra, Francisco; Rodríguez, Elsa; Montero, Carlos; Méndez, Lídice; Capucci, Lorenzo; Farnós, Omar

    2011-08-15

    Rabbit hemorrhagic disease virus (RHDV) is the etiological agent of a lethal and contagious disease of rabbits that remains as a serious problem worldwide. As this virus does not replicate in cell culture systems, the capsid protein gene has been expressed in heterologous hosts or inserted in replication-competent viruses in order to obtain non-conventional RHDV vaccines. However, due to technological or safety issues, current RHDV vaccines are still prepared from organs of infected rabbits. In this work, two human type 5 derived replication-defective adenoviruses encoding the rabbit hemorrhagic disease virus VP60 capsid protein were constructed. The recombinant protein was expressed as a multimer in mouse and rabbit cell lines at levels that ranged from approximately 120 to 160 mg/L of culture. Mice intravenously or subcutaneously inoculated with a single 10(8) gene transfer units (GTU) dose of the AdVP60 vector (designed for VP60 intracellular expression) seroconverted at days 7 and 14 post-immunization, respectively. This vector generated a stronger response than that obtained with a second vector (AdVP60sec) designed for VP60 secretion. Rabbits were then immunized by parenteral or mucosal routes with a single 10(9)GTU dose of the AdVP60 and the antibody response was evaluated using a competition ELISA specific for RHDV or RHDVa. Protective hemagglutination inhibition (HI) titers were also promptly detected and IgG antibodies corresponding with inhibition percentages over 85% persisted up to one year in all rabbits, independently of the immunization route employed. These levels were similar to those elicited with inactivated RHDV or with VP60 obtained from yeast or insect cells. IgA specific antibodies were only found in saliva of rabbits immunized by intranasal instillation. The feasibility of VP60 production and vaccination of rabbits with replication-defective adenoviral vectors was demonstrated.

  5. Victims, vectors and villains: are those who opt out of vaccination morally responsible for the deaths of others?

    PubMed Central

    Selgelid, Michael J

    2016-01-01

    Mass vaccination has been a successful public health strategy for many contagious diseases. The immunity of the vaccinated also protects others who cannot be safely or effectively vaccinated—including infants and the immunosuppressed. When vaccination rates fall, diseases like measles can rapidly resurge in a population. Those who cannot be vaccinated for medical reasons are at the highest risk of severe disease and death. They thus may bear the burden of others' freedom to opt out of vaccination. It is often asked whether it is legitimate for states to adopt and enforce mandatory universal vaccination. Yet this neglects a related question: are those who opt out, where it is permitted, morally responsible when others are harmed or die as a result of their decision? In this article, we argue that individuals who opt out of vaccination are morally responsible for resultant harms to others. Using measles as our main example, we demonstrate the ways in which opting out of vaccination can result in a significant risk of harm and death to others, especially infants and the immunosuppressed. We argue that imposing these risks without good justification is blameworthy and examine ways of reaching a coherent understanding of individual moral responsibility for harms in the context of the collective action required for disease transmission. Finally, we consider several objections to this view, provide counterarguments and suggest morally permissible alternatives to mandatory universal vaccination including controlled infection, self-imposed social isolation and financial penalties for refusal to vaccinate. PMID:27697791

  6. [Antiviral vaccines].

    PubMed

    Girard, M

    1999-01-01

    Vaccination has been successful in controlling numerous diseases in man and animals. Smallpox has been eradicated and poliomyelitis is on the verge of being eradicated. The traditional immunization arsenal includes vaccines using live, attenuated, and inactivated organisms. DNA recombinant technology has added two new types of vaccines, i.e. subunit vaccines based on purified antigens produced by genetic engineering in bacterial, yeast, or animal-cell cultures and live recombinant vaccines based on attenuated bacterial or viral vectors. Currently the best known examples of these new vaccines are those using poxvirus vectors (vaccinia virus, canarypox virus, or fowlpox virus) but new vectors are under development. Another application for genetic engineering in the field of vaccinology is the development of DNA vaccines using naked plasmid DNA. This technique has achieved remarkable results in small rodents but its efficacy, safety, and feasibility in man has yet to be demonstrated. Numerous studies are now under way to improve the process. In the field of synthetic vaccines, lipopeptides have shown promise for induction of cell immune response. Development of vaccines for administration by the oral or nasal route may one day revolutionize vaccination techniques. However, effective vaccines against hepatitis C and HIV have stalled in the face of the complexity and pathophysiology of these diseases. These are the greatest challenges confronting scientists at the dawn of the new millennium.

  7. HIV-1 adenoviral vector vaccines expressing multi-trimeric BAFF and 4-1BBL enhance T cell mediated anti-viral immunity.

    PubMed

    Kanagavelu, Saravana; Termini, James M; Gupta, Sachin; Raffa, Francesca N; Fuller, Katherine A; Rivas, Yaelis; Philip, Sakhi; Kornbluth, Richard S; Stone, Geoffrey W

    2014-01-01

    Adenoviral vectored vaccines have shown considerable promise but could be improved by molecular adjuvants. Ligands in the TNF superfamily (TNFSF) are potential adjuvants for adenoviral vector (Ad5) vaccines based on their central role in adaptive immunity. Many TNFSF ligands require aggregation beyond the trimeric state (multi-trimerization) for optimal biological function. Here we describe Ad5 vaccines for HIV-1 Gag antigen (Ad5-Gag) adjuvanted with the TNFSF ligands 4-1BBL, BAFF, GITRL and CD27L constructed as soluble multi-trimeric proteins via fusion to Surfactant Protein D (SP-D) as a multimerization scaffold. Mice were vaccinated with Ad5-Gag combined with Ad5 expressing one of the SP-D-TNFSF constructs or single-chain IL-12p70 as adjuvant. To evaluate vaccine-induced protection, mice were challenged with vaccinia virus expressing Gag (vaccinia-Gag) which is known to target the female genital tract, a major route of sexually acquired HIV-1 infection. In this system, SP-D-4-1BBL or SP-D-BAFF led to significantly reduced vaccinia-Gag replication when compared to Ad5-Gag alone. In contrast, IL-12p70, SP-D-CD27L and SP-D-GITRL were not protective. Histological examination following vaccinia-Gag challenge showed a dramatic lymphocytic infiltration into the uterus and ovaries of SP-D-4-1BBL and SP-D-BAFF-treated animals. By day 5 post challenge, proinflammatory cytokines in the tissue were reduced, consistent with the enhanced control over viral replication. Splenocytes had no specific immune markers that correlated with protection induced by SP-D-4-1BBL and SP-D-BAFF versus other groups. IL-12p70, despite lack of anti-viral efficacy, increased the total numbers of splenic dextramer positive CD8+ T cells, effector memory T cells, and effector Gag-specific CD8+ T cells, suggesting that these markers are poor predictors of anti-viral immunity in this model. In conclusion, soluble multi-trimeric 4-1BBL and BAFF adjuvants led to strong protection from vaccinia

  8. Adenovirus Specific Pre-Immunity Induced by Natural Route of Infection Does Not Impair Transduction by Adenoviral Vaccine Vectors in Mice

    PubMed Central

    de Andrade Pereira, Bruna; E. Maduro Bouillet, Leoneide; Dorigo, Natalia A.; Fraefel, Cornel; Bruna-Romero, Oscar

    2015-01-01

    Recombinant human adenovirus serotype 5 (HAd5V) vectors are gold standards of T-cell immunogenicity as they efficiently induce also humoral responses to exogenous antigens, in particular when used in prime-boost protocols. Some investigators have shown that pre-existing immunity to adenoviruses interferes with transduction by adenoviral vectors, but the actual extent of this interference is not known since it has been mostly studied in mice using unnatural routes of infection and virus doses. Here we studied the effects of HAd5V-specific immune responses induced by intranasal infection on the transduction efficiency of recombinant adenovirus vectors. Of interest, when HAd5V immunity was induced in mice by the natural respiratory route, the pre-existing immunity against HAd5V did not significantly interfere with the B and T-cell immune responses against the transgene products induced after a prime/boost inoculation protocol with a recombinant HAd5V-vector, as measured by ELISA and in vivo cytotoxic T-cell assays, respectively. We also correlated the levels of HAd5V-specific neutralizing antibodies (Ad5NAbs) induced in mice with the levels of Ad5NAb titers found in humans. The data indicate that approximately 60% of the human serum samples tested displayed Ad5NAb levels that could be overcome with a prime-boost vaccination protocol. These results suggest that recombinant HAd5V vectors are potentially useful for prime-boost vaccination strategies, at least when pre-existing immunity against HAd5V is at low or medium levels. PMID:26679149

  9. Adenovirus Specific Pre-Immunity Induced by Natural Route of Infection Does Not Impair Transduction by Adenoviral Vaccine Vectors in Mice.

    PubMed

    de Andrade Pereira, Bruna; Maduro Bouillet, Leoneide E; Dorigo, Natalia A; Fraefel, Cornel; Bruna-Romero, Oscar

    2015-01-01

    Recombinant human adenovirus serotype 5 (HAd5V) vectors are gold standards of T-cell immunogenicity as they efficiently induce also humoral responses to exogenous antigens, in particular when used in prime-boost protocols. Some investigators have shown that pre-existing immunity to adenoviruses interferes with transduction by adenoviral vectors, but the actual extent of this interference is not known since it has been mostly studied in mice using unnatural routes of infection and virus doses. Here we studied the effects of HAd5V-specific immune responses induced by intranasal infection on the transduction efficiency of recombinant adenovirus vectors. Of interest, when HAd5V immunity was induced in mice by the natural respiratory route, the pre-existing immunity against HAd5V did not significantly interfere with the B and T-cell immune responses against the transgene products induced after a prime/boost inoculation protocol with a recombinant HAd5V-vector, as measured by ELISA and in vivo cytotoxic T-cell assays, respectively. We also correlated the levels of HAd5V-specific neutralizing antibodies (Ad5NAbs) induced in mice with the levels of Ad5NAb titers found in humans. The data indicate that approximately 60% of the human serum samples tested displayed Ad5NAb levels that could be overcome with a prime-boost vaccination protocol. These results suggest that recombinant HAd5V vectors are potentially useful for prime-boost vaccination strategies, at least when pre-existing immunity against HAd5V is at low or medium levels.

  10. A Phase I Double Blind, Placebo-Controlled, Randomized Study of a Multigenic HIV-1 Adenovirus Subtype 35 Vector Vaccine in Healthy Uninfected Adults

    PubMed Central

    Hayes, Peter; Gill, Dilbinder; Kopycinski, Jakub; Cheeseman, Hannah; Cashin-Cox, Michelle; Naarding, Marloes; Clark, Lorna; Fernandez, Natalia; Bunce, Catherine A.; Hay, Christine M.; Welsh, Sabrina; Komaroff, Wendy; Hachaambwa, Lottie; Tarragona-Fiol, Tony; Sayeed, Eddy; Zachariah, Devika; Ackland, James; Loughran, Kelley; Barin, Burc; Cormier, Emmanuel; Cox, Josephine H.; Fast, Patricia; Excler, Jean-Louis

    2012-01-01

    Background We conducted a phase I, randomized, double-blind, placebo-controlled trial to assess the safety and immunogenicity of escalating doses of two recombinant replication defective adenovirus serotype 35 (Ad35) vectors containing gag, reverse transcriptase, integrase and nef (Ad35-GRIN) and env (Ad35-ENV), both derived from HIV-1 subtype A isolates. The trial enrolled 56 healthy HIV-uninfected adults. Methods Ad35-GRIN/ENV (Ad35-GRIN and Ad35-ENV mixed in the same vial in equal proportions) or Ad35-GRIN was administered intramuscularly at 0 and 6 months. Participants were randomized to receive either vaccine or placebo (10/4 per group, respectively) within one of four dosage groups: Ad35-GRIN/ENV 2×109 (A), 2×1010 (B), 2×1011 (C), or Ad35-GRIN 1×1010 (D) viral particles. Results No vaccine-related serious adverse event was reported. Reactogenicity events reported were dose-dependent, mostly mild or moderate, some severe in Group C volunteers, all transient and resolving spontaneously. IFN-γ ELISPOT responses to any vaccine antigen were detected in 50, 56, 70 and 90% after the first vaccination, and in 75, 100, 88 and 86% of Groups A–D vaccine recipients after the second vaccination, respectively. The median spot forming cells (SFC) per 106 PBMC to any antigen was 78–139 across Groups A–C and 158–174 in Group D, after each of the vaccinations with a maximum of 2991 SFC. Four to five HIV proteins were commonly recognized across all the groups and over multiple timepoints. CD4+ and CD8+ T-cell responses were polyfunctional. Env antibodies were detected in all Group A–C vaccinees and Gag antibodies in most vaccinees after the second immunization. Ad35 neutralizing titers remained low after the second vaccination. Conclusion/Significance Ad35-GRIN/ENV reactogenicity was dose-related. HIV-specific cellular and humoral responses were seen in the majority of volunteers immunized with Ad35-GRIN/ENV or Ad35-GRIN and increased after the second vaccination

  11. Immunogenicity of the recombinant adenovirus type-5 vector -based Ebola vaccine (Ad5-EBOV) expressing the glycoprotein of the 2014 epidemic strain in mice.

    PubMed

    Wang, Ling; Liu, Jing Jing; Kong, Yan; Hou, Li Hua; Li, Yu Hua

    2017-08-10

    The 2014 Ebola outbreak in West Africa has brought great threat to the public health worldwide. Development of Ebola vaccine is urgent. A novel recombinant adenovirus type-5 vector-based Ebola vaccine (Ad5-EBOV) based on the 2014 Zaire Guinea epidemic strain was developed in China. A good safety profile and robust immune response elicited by Ad5-EBOV were confirmed in Phase I and Phase II clinical trial. However, clinical studies of Ebola vaccine are still at an early stage and no solid efficacy data for human beings yet. For efficacy evaluation and quality control of Ad5-EBOV, the cellular and humoral immune responses were examined at different time points in BALB/c mice which were vaccinated with the Ad5-EBOV. EBOV GP-specific T-cell responses were detected early in the first week, increased overtime, reached the peak at week 4 and lasted to week 6 by ELISpot and Flow cytometric analysis. High titer of EBOV glycoprotein-specific antibody was found at week 1 at 1783(geometric mean, GM), peaked at week 10 at 26,214(GM), and lasted to six months at 1351(GM). The titer of neutralizing antibody based on pseudovirus also increased overtime, peaked at 1:16 in one mouse and 1:8 in nine mice at week 6, then decreased to zero at week 12. These results suggest that BALB/c mice can be used to evaluate the effectiveness of Ad5-EBOV, while cellular immune response and humoral immune response can be used as indicators for the evaluation of vaccine effectiveness. Determination of methods and indicators as soon as possible is critical and valuable for efficacy evaluation of Ebola vaccine, and is expected to provide an important guarantee for quality control of Ad5-EBOV.

  12. Seroprevalence of Fowl Pox Antibody in Indigenous Chickens in Jos North and South Council Areas of Plateau State, Nigeria: Implication for Vector Vaccine

    PubMed Central

    Adebajo, Meseko Clement; Ademola, Shittu Ismail; Oluwaseun, Akinyede

    2012-01-01

    Fowl pox is a viral disease of domestic and wild birds. The large size of the genome makes it a useful vector for recombinant DNA technology. Although the disease has been described in both commercial and indigenous chickens in Nigeria, data are limited on seroprevalence in free range chickens. Such data are, however, important in the design and implementation of fowl pox virus vector vaccine. We surveyed current antibody status to fowl pox virus in free range chickens by testing 229 sera collected from 10 villages in Jos North and Jos South LGA of Plateau State Nigeria. Sera were analyzed by AGID against standard fowl pox antigen. Fifty-two of the 229 (23%) tested sera were positive for fowl pox virus antibody, and the log titre in all positive specimen was >2. Thirty (21%) and twenty-two (27%) of the samples from Jos South and Jos North, respectively, tested positive. This was, however, not statistically significant (P = 0.30). Generally the study showed a significant level of antibody to fowl pox virus in the study area. This observation may hinder effective use of fowl pox vectored viral vaccine. Fowl pox control is recommended to reduce natural burden of the disease. PMID:23762578

  13. Seroprevalence of fowl pox antibody in indigenous chickens in jos north and South council areas of plateau state, Nigeria: implication for vector vaccine.

    PubMed

    Adebajo, Meseko Clement; Ademola, Shittu Ismail; Oluwaseun, Akinyede

    2012-01-01

    Fowl pox is a viral disease of domestic and wild birds. The large size of the genome makes it a useful vector for recombinant DNA technology. Although the disease has been described in both commercial and indigenous chickens in Nigeria, data are limited on seroprevalence in free range chickens. Such data are, however, important in the design and implementation of fowl pox virus vector vaccine. We surveyed current antibody status to fowl pox virus in free range chickens by testing 229 sera collected from 10 villages in Jos North and Jos South LGA of Plateau State Nigeria. Sera were analyzed by AGID against standard fowl pox antigen. Fifty-two of the 229 (23%) tested sera were positive for fowl pox virus antibody, and the log titre in all positive specimen was >2. Thirty (21%) and twenty-two (27%) of the samples from Jos South and Jos North, respectively, tested positive. This was, however, not statistically significant (P = 0.30). Generally the study showed a significant level of antibody to fowl pox virus in the study area. This observation may hinder effective use of fowl pox vectored viral vaccine. Fowl pox control is recommended to reduce natural burden of the disease.

  14. Impact of fowlpox-vectored Mycoplasma gallisepticum vaccine Vectormune FP MG on layer hen egg production and egg quality parameters.

    PubMed

    Leigh, S A; Branton, S L; Evans, J D; Collier, S D

    2013-12-01

    This study was conducted to determine the impact of vaccination with Vectormune FP MG on egg production and egg quality characteristics of Single Comb White Leghorn hens. Due to questions of the efficacy of this vaccine in preventing Mycoplasma gallisepticum-mediated pathology, the ability of this vaccine to protect against postproduction-peak egg losses associated with F-strain M. gallisepticum (FMG) vaccination was also investigated. Vaccination with Vectormune FP MG did not result in any significant change in egg production or egg quality parameters compared with control (unvaccinated) hens. Subsequent revaccination with FMG at 45 wk of age (woa) yielded no impact on egg production or egg quality parameters of Vectormune FP MG vaccinated hens, unlike prior results for postproduction-peak vaccination of M. gallisepticum-clean hens with FMG, which exhibited a drop in egg production of approximately 6%. No difference in egg size distribution was observed for any of the treatment groups before or after FMG revaccination. These results suggest that hens can be safely vaccinated with Vectormune FP MG as pullets and can be revaccinated with a live M. gallisepticum vaccine such as FMG at a later date with no deleterious effects on egg production or egg or eggshell quality parameters.

  15. Baculovirus-vectored multistage Plasmodium vivax vaccine induces both protective and transmission-blocking immunities against transgenic rodent malaria parasites.

    PubMed

    Mizutani, Masanori; Iyori, Mitsuhiro; Blagborough, Andrew M; Fukumoto, Shinya; Funatsu, Tomohiro; Sinden, Robert E; Yoshida, Shigeto

    2014-10-01

    A multistage malaria vaccine targeting the pre-erythrocytic and sexual stages of Plasmodium could effectively protect individuals against infection from mosquito bites and provide transmission-blocking (TB) activity against the sexual stages of the parasite, respectively. This strategy could help prevent malaria infections in individuals and, on a larger scale, prevent malaria transmission in communities of endemicity. Here, we describe the development of a multistage Plasmodium vivax vaccine which simultaneously expresses P. vivax circumsporozoite protein (PvCSP) and P25 (Pvs25) protein of this species as a fusion protein, thereby acting as a pre-erythrocytic vaccine and a TB vaccine, respectively. A new-concept vaccine platform based on the baculovirus dual-expression system (BDES) was evaluated. The BDES-Pvs25-PvCSP vaccine displayed correct folding of the Pvs25-PvCSP fusion protein on the viral envelope and was highly expressed upon transduction of mammalian cells in vitro. This vaccine induced high levels of antibodies to Pvs25 and PvCSP and elicited protective (43%) and TB (82%) efficacies against transgenic P. berghei parasites expressing the corresponding P. vivax antigens in mice. Our data indicate that our BDES, which functions as both a subunit and DNA vaccine, can offer a promising multistage vaccine capable of delivering a potent antimalarial pre-erythrocytic and TB response via a single immunization regimen. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  16. Pre-clinical efficacy and safety of experimental vaccines based on non-replicating vaccinia vectors against yellow fever.

    PubMed

    Schäfer, Birgit; Holzer, Georg W; Joachimsthaler, Alexandra; Coulibaly, Sogue; Schwendinger, Michael; Crowe, Brian A; Kreil, Thomas R; Barrett, P Noel; Falkner, Falko G

    2011-01-01

    Currently existing yellow fever (YF) vaccines are based on the live attenuated yellow fever virus 17D strain (YFV-17D). Although, a good safety profile was historically attributed to the 17D vaccine, serious adverse events have been reported, making the development of a safer, more modern vaccine desirable. A gene encoding the precursor of the membrane and envelope (prME) protein of the YFV-17D strain was inserted into the non-replicating modified vaccinia virus Ankara and into the D4R-defective vaccinia virus. Candidate vaccines based on the recombinant vaccinia viruses were assessed for immunogenicity and protection in a mouse model and compared to the commercial YFV-17D vaccine. The recombinant live vaccines induced γ-interferon-secreting CD4- and functionally active CD8-T cells, and conferred full protection against lethal challenge already after a single low immunization dose of 10(5) TCID(50). Surprisingly, pre-existing immunity against wild-type vaccinia virus did not negatively influence protection. Unlike the classical 17D vaccine, the vaccinia virus-based vaccines did not cause mortality following intracerebral administration in mice, demonstrating better safety profiles. The non-replicating recombinant YF candidate live vaccines induced a broad immune response after single dose administration, were effective even in the presence of a pre-existing immunity against vaccinia virus and demonstrated an excellent safety profile in mice.

  17. An Oral Aβ Vaccine Using a Recombinant Adeno-Associated Virus Vector in Aged Monkeys: Reduction in Plaque Amyloid and Increase in Aβ Oligomers.

    PubMed

    Hara, Hideo; Ono, Fumiko; Nakamura, Shinichiro; Matsumoto, Shin-Ei; Jin, Haifeng; Hattori, Nobutaka; Tabira, Takeshi

    2016-10-04

    With the objective to improve the amyloid-β (Aβ) targeting immunotherapy, we investigated the safety and efficacy of an oral vaccine with recombinant adeno-associated virus vector carrying a signal sequence and Aβ1-43 cDNA (rAAV/Aβ) in old non-human primates, 12 African green and 10 cynomolgus monkeys. The enteric-dissolving coated capsules containing rAAV/Aβ were orally administered once or twice, then monkeys' conditions were carefully observed with complete blood count and laboratory examinations of the sera. General conditions, food intake, water intake, stool conditions, body weight changes, and menstruation cycles were not significantly altered, and laboratory tests and pathological examinations of the systemic organs were unremarkable. Pathological examinations of the brain showed significant reduction of the amyloid plaque burden and intracellular Aβ without inflammatory or hemorrhagic changes in the brain. However, soluble Aβ and some Aβ oligomers were increased in rAAV-treated monkey brains without changes of the neuronal density and vascular amyloidosis. Thus, this vaccine seems to be safe in general, but we must be cautious about the increase of Aβ oligomers after vaccination. This vaccine may be recommended at a very early stage of Alzheimer's disease when little amyloid is deposited.

  18. Evaluation of attenuation, immunogenicity and efficacy of a bovine parainfluenza virus type 3 (PIV-3) vaccine and a recombinant chimeric bovine/human PIV-3 vaccine vector in rhesus monkeys.

    PubMed

    Pennathur, Sridhar; Haller, Aurelia A; MacPhail, Mia; Rizzi, Tom; Kaderi, Sepideh; Fernandes, Fiona; Bicha, Leenas; Schickli, Jeanne H; Tang, Roderick S; Chen, Wendy; Nguyen, Nick; Mathie, Sharon; Mehta, Hersh; Coelingh, Kathleen L

    2003-12-01

    Restricted replication in the respiratory tract of rhesus monkeys is an intrinsic property of bovine parainfluenza virus type 3 (bPIV-3) strains. This host range phenotype of bPIV-3 has been utilized as a marker to evaluate the attenuation of bPIV-3 vaccines for human use. Two safety, immunogenicity and efficacy studies in primates evaluated and compared three human parainfluenza virus type 3 (hPIV-3) vaccine candidates: biologically derived bPIV-3, a plasmid-derived bPIV-3 (r-bPIV-3) and a chimeric bovine/human PIV-3 (b/hPIV-3). These studies also examined the feasibility of substituting Vero cells, cultured in the presence or absence of foetal bovine serum, for foetal rhesus lung-2 (FRhL-2) cells as the tissue culture substrate for the production of bPIV-3 vaccine. The results demonstrated that (i) Vero cell-produced bPIV-3 was as attenuated, immunogenic and efficacious as bPIV-3 vaccine grown in FRhL-2 cells, (ii) plasmid-derived bPIV-3 was as attenuated, immunogenic and efficacious as the biologically derived bPIV-3 and (iii) the b/hPIV-3 chimera displayed an intermediate attenuation phenotype and protected animals completely from hPIV-3 challenge. These results support the use of bPIV-3 vaccines propagated in Vero cells in human clinical trials and the use of b/hPIV-3 as a virus vaccine vector to express foreign viral antigens.

  19. Victims, vectors and villains: are those who opt out of vaccination morally responsible for the deaths of others?

    PubMed

    Jamrozik, Euzebiusz; Handfield, Toby; Selgelid, Michael J

    2016-12-01

    Mass vaccination has been a successful public health strategy for many contagious diseases. The immunity of the vaccinated also protects others who cannot be safely or effectively vaccinated-including infants and the immunosuppressed. When vaccination rates fall, diseases like measles can rapidly resurge in a population. Those who cannot be vaccinated for medical reasons are at the highest risk of severe disease and death. They thus may bear the burden of others' freedom to opt out of vaccination. It is often asked whether it is legitimate for states to adopt and enforce mandatory universal vaccination. Yet this neglects a related question: are those who opt out, where it is permitted, morally responsible when others are harmed or die as a result of their decision? In this article, we argue that individuals who opt out of vaccination are morally responsible for resultant harms to others. Using measles as our main example, we demonstrate the ways in which opting out of vaccination can result in a significant risk of harm and death to others, especially infants and the immunosuppressed. We argue that imposing these risks without good justification is blameworthy and examine ways of reaching a coherent understanding of individual moral responsibility for harms in the context of the collective action required for disease transmission. Finally, we consider several objections to this view, provide counterarguments and suggest morally permissible alternatives to mandatory universal vaccination including controlled infection, self-imposed social isolation and financial penalties for refusal to vaccinate. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  20. The prevalence of neutralizing antibodies against AAV serotype 1 in healthy subjects in China: implications for gene therapy and vaccines using AAV1 vector.

    PubMed

    Liu, Qiang; Huang, Weijin; Zhao, Chenyan; Zhang, Li; Meng, Shufang; Gao, Dongying; Wang, Youchun

    2013-09-01

    Recombinant adeno-associated virus serotype 1 (AAV1) has attracted tremendous interest as a promising vector for gene therapy and vaccine applications. However, the presence of AAV1 neutralizing antibodies as a consequence of exposure to wild type AAV1 can limit significantly effective gene transfer for biologics based AAV1 vector. Prior studies have reported that a prevalence of AAV1 neutralizing antibodies ranged from 10% to 50% in different countries around the world, and up to 79% in Dutch subjects. However, few studies have reported on the AAV1 neutralizing antibody prevalence in Chinese subjects. In this study, a high-throughput luciferase-based virus neutralization assay was established and standardized for critical parameters, including the appropriate cell line, and the optimal viral infection dose, and the infection time with homologous AAV1 vaccinated mice and guinea pig sera. Then, a total of 500 healthy individual serum samples from two separate regions of China were screened for the AAV1 neutralizing antibodies by conducting a non-randomized, cross-sectional analysis. Interestingly, a high prevalence of AAV1 neutralizing antibody (69.8%) was found in all individuals. There was significant difference observed for prevalence by gender (P = 0.042), age range (P = 0.011) and geographic origin (P < 0.001). The percentage of positive AAV1 neutralizing antibodies (NT50  > 10) in teenagers (year <18, as of 2012) was significant lower than that of adults (19-56, as of 2012) (P = 0.011), indicating the optimal vaccination period of childhood. The current study provides a useful insight for the future development of AAV1-based vaccination and gene therapy strategies in Beijing and Anhui provinces of China.

  1. Development of an acid-resistant Salmonella Typhi Ty21a attenuated vector for improved oral vaccine delivery

    USDA-ARS?s Scientific Manuscript database

    The licensed oral, live-attenuated bacterial vaccine for typhoid fever, Salmonella Typhi strain Ty21a, has also been utilized as a vaccine delivery platform for expression of diverse foreign antigens that stimulate protection against shigellosis, anthrax, plague, or human papilloma virus. However, T...

  2. Individual and bivalent vaccines against botulinum neurotoxin serotypes A and B using DNA-based Semliki Forest virus vectors.

    PubMed

    Yu, Yunzhou; Yu, Jiyu; Li, Na; Wang, Shuang; Yu, Weiyuan; Sun, Zhiwei

    2009-10-19

    We evaluated individual and bivalent replicon vaccines against Clostridiumbotulinum neurotoxin serotypes A (BoNT/A) or B (BoNT/B). The DNA replicon vaccine (pSCARSBHc) encoding the Hc domain of BoNT/B (BHc) induced better responses and protection against BoNT/B mouse challenge than conventional DNA vaccine. The dual-expressing DNA vaccine (pSCARSA/BHc) protected similarly to a DNA replicon vaccine mixture (pSCARSAHc+pSCARSBHc). Additionally, recombinant SFV particles, VRP-AHc or VRP-BHc, protected mice from high-dose BoNT/A or BoNT/B challenge, respectively. Mice given either dual-expressing VRP-A/BHc or mixture of VRP-AHc and VRP-BHc were protected from challenge with serotype A/B mixtures. These data justify further testing in other animals or humans.

  3. Pentavalent replicon vaccines against botulinum neurotoxins and tetanus toxin using DNA-based Semliki Forest virus replicon vectors

    PubMed Central

    Yu, YunZhou; Liu, Si; Ma, Yao; Gong, Zheng-Wei; Wang, Shuang; Sun, Zhi-Wei

    2014-01-01

    The clostridial neurotoxin (CNT) family includes botulinum neurotoxin (BoNT), serotypes A, B, E, and F of which can cause human botulism, and tetanus neurotoxin (TeNT), which is the causative agent of tetanus. This suggests that the greatest need is for a multivalent or multiagent vaccine that provides protection against all 5 agents. In this study, we investigated the feasibility of generating several pentavalent replicon vaccines that protected mice against BoNTs and TeNT. First, we evaluated the potency of individual replicon DNA or particle vaccine against TeNT, which induced strong antibody and protective responses in BALB/c mice following 2 or 3 immunizations. Then, the individual replicon TeNT vaccines were combined with tetravalent BoNTs vaccines to prepare 4 types of pentavalent replicon vaccines. These replicon DNA or particle pentavalent vaccines could simultaneously and effectively induce antibody responses and protect effects against the 5 agents. Finally, a solid-phase assay showed that the sera of pentavalent replicon formulations-immunized mice inhibited the binding of THc to the ganglioside GT1b as the sera of individual replicon DNA or particle-immunized mice. These results indicated these pentavalent replicon vaccines could protect against the 4 BoNT serotypes and effectively neutralize and protect the TeNT. Therefore, our studies demonstrate the utility of combining replicon DNA or particle vaccines into multi-agent formulations as potent pentavalent vaccines for eliciting protective responses against BoNTs and TeNT. PMID:25424795

  4. A modified vaccinia Ankara vaccine vector expressing a mosaic H5 hemagglutinin reduces viral shedding in rhesus macaques.

    PubMed

    Florek, Nicholas W; Kamlangdee, Attapon; Mutschler, James P; Kingstad-Bakke, Brock; Schultz-Darken, Nancy; Broman, Karl W; Osorio, Jorge E; Friedrich, Thomas C

    2017-01-01

    The rapid antigenic evolution of influenza viruses requires frequent vaccine reformulations. Due to the economic burden of continuous vaccine reformulation and the threat of new pandemics, there is intense interest in developing vaccines capable of eliciting broadly cross-reactive immunity to influenza viruses. We recently constructed a "mosaic" hemagglutinin (HA) based on subtype 5 HA (H5) and designed to stimulate cellular and humoral immunity to multiple influenza virus subtypes. Modified vaccinia Ankara (MVA) expressing this H5 mosaic (MVA-H5M) protected mice against multiple homosubtypic H5N1 strains and a heterosubtypic H1N1 virus. To assess its potential as a human vaccine we evaluated the ability of MVA-H5M to provide heterosubtypic immunity to influenza viruses in a non-human primate model. Rhesus macaques received an initial dose of either MVA-H5M or plasmid DNA encoding H5M, followed by a boost of MVA-H5M, and then were challenged, together with naïve controls, with the heterosubtypic virus A/California/04/2009 (H1N1pdm). Macaques receiving either vaccine regimen cleared H1N1pdm challenge faster than naïve controls. Vaccination with H5M elicited antibodies that bound H1N1pdm HA, but did not neutralize the H1N1pdm challenge virus. Plasma from vaccinated macaques activated NK cells in the presence of H1N1pdm HA, suggesting that vaccination elicited cross-reactive antibodies capable of mediating antibody-dependent cell-mediated cytotoxicity (ADCC). Although HA-specific T cell responses to the MVA-H5M vaccine were weak, responses after challenge were stronger in vaccinated macaques than in control animals. Together these data suggest that mosaic HA antigens may provide a means for inducing broadly cross-reactive immunity to influenza viruses.

  5. A modified vaccinia Ankara vaccine vector expressing a mosaic H5 hemagglutinin reduces viral shedding in rhesus macaques

    PubMed Central

    Mutschler, James P.; Kingstad-Bakke, Brock; Schultz-Darken, Nancy; Broman, Karl W.; Osorio, Jorge E.

    2017-01-01

    The rapid antigenic evolution of influenza viruses requires frequent vaccine reformulations. Due to the economic burden of continuous vaccine reformulation and the threat of new pandemics, there is intense interest in developing vaccines capable of eliciting broadly cross-reactive immunity to influenza viruses. We recently constructed a “mosaic” hemagglutinin (HA) based on subtype 5 HA (H5) and designed to stimulate cellular and humoral immunity to multiple influenza virus subtypes. Modified vaccinia Ankara (MVA) expressing this H5 mosaic (MVA-H5M) protected mice against multiple homosubtypic H5N1 strains and a heterosubtypic H1N1 virus. To assess its potential as a human vaccine we evaluated the ability of MVA-H5M to provide heterosubtypic immunity to influenza viruses in a non-human primate model. Rhesus macaques received an initial dose of either MVA-H5M or plasmid DNA encoding H5M, followed by a boost of MVA-H5M, and then were challenged, together with naïve controls, with the heterosubtypic virus A/California/04/2009 (H1N1pdm). Macaques receiving either vaccine regimen cleared H1N1pdm challenge faster than naïve controls. Vaccination with H5M elicited antibodies that bound H1N1pdm HA, but did not neutralize the H1N1pdm challenge virus. Plasma from vaccinated macaques activated NK cells in the presence of H1N1pdm HA, suggesting that vaccination elicited cross-reactive antibodies capable of mediating antibody-dependent cell-mediated cytotoxicity (ADCC). Although HA-specific T cell responses to the MVA-H5M vaccine were weak, responses after challenge were stronger in vaccinated macaques than in control animals. Together these data suggest that mosaic HA antigens may provide a means for inducing broadly cross-reactive immunity to influenza viruses. PMID:28771513

  6. An Alphavirus Replicon Particle Chimera Derived from Venezuelan Equine Encephalitis and Sindbis Viruses Is a Potent Gene-Based Vaccine Delivery Vector

    PubMed Central

    Perri, Silvia; Greer, Catherine E.; Thudium, Kent; Doe, Barbara; Legg, Harold; Liu, Hong; Romero, Raul E.; Tang, Zequn; Bin, Qian; Dubensky, Thomas W.; Vajdy, Michael; Otten, Gillis R.; Polo, John M.

    2003-01-01

    Alphavirus replicon particle-based vaccine vectors derived from Sindbis virus (SIN), Semliki Forest virus, and Venezuelan equine encephalitis virus (VEE) have been shown to induce robust antigen-specific cellular, humoral, and mucosal immune responses in many animal models of infectious disease and cancer. However, since little is known about the relative potencies among these different vectors, we compared the immunogenicity of replicon particle vectors derived from two very different parental alphaviruses, VEE and SIN, expressing a human immunodeficiency virus type 1 p55Gag antigen. Moreover, to explore the potential benefits of combining elements from different alphaviruses, we generated replicon particle chimeras of SIN and VEE. Two distinct strategies were used to produce particles with VEE-p55gag replicon RNA packaged within SIN envelope glycoproteins and SIN-p55gag replicon RNA within VEE envelope glycoproteins. Each replicon particle configuration induced Gag-specific CD8+ T-cell responses in murine models when administered alone or after priming with DNA. However, Gag-specific responses varied dramatically, with the strongest responses to this particular antigen correlating with the VEE replicon RNA, irrespective of the source of envelope glycoproteins. Comparing the replicons with respect to heterologous gene expression levels and sensitivity to alpha/beta interferon in cultured cells indicated that each might contribute to potency differences. This work shows that combining desirable elements from VEE and SIN into a replicon particle chimera may be a valuable approach toward the goal of developing vaccine vectors with optimal in vivo potency, ease of production, and safety. PMID:12970424

  7. Safety and immunogenicity in humans of an attenuated Salmonella typhi vaccine vector strain expressing plasmid-encoded hepatitis B antigens stabilized by the Asd-balanced lethal vector system.

    PubMed Central

    Tacket, C O; Kelly, S M; Schödel, F; Losonsky, G; Nataro, J P; Edelman, R; Levine, M M; Curtiss, R

    1997-01-01

    Attenuated Salmonella typhi organisms which express genes encoding protective antigens of other pathogens have been developed for use as experimental oral vaccines. A delta asd S. typhi strain attenuated by deletions in cya, crp, and cdt which contains hepatitis B core (HBc) and pre-S genes encoded on an Asd+ pBR-based plasmid vector was constructed. Healthy adult volunteers ingested a single dose of 5 x 10(5) to 5 x 10(8) CFU of strain chi4073 (delta cya delta crp delta cdt S. typhi Ty2), 6 x 10(7) or 1 x 10(9) CFU of strain chi4632(pYA3149), a further derivative of chi4073 deleted in asd and containing the Asd+ vector without the HBc-pre-S fusion, or 3 x 10(7) or 7 x 10(8) CFU of strain X4632(pYA3167), a derivative containing the vector with the HBc-pre-S fusion. Chi4073 was generally well tolerated by 22 volunteers. No volunteer had fever or positive blood cultures; 4 of 22 volunteers shed vaccine organisms in the stool in the first 48 h only. Two of 18 volunteers who received one of the plasmid-containing derivatives of chi4073 developed low-grade fevers on day 10 or 12 after ingestion. One of these volunteers had positive blood cultures on days 7 and 8. Seven of these 18 volunteers had vaccine organisms detected in their stools in the first 48 h only. Most volunteers developed S. typhi-specific serum responses and developed S. typhi-specific antibody-secreting cells. However, no volunteer developed serum antibody to hepatitis pre-S or pre-S-specific antibody-secreting cells. Although the parent strain chi4073 was well tolerated, induced immunoglobulin G seroconversion to S. typhi lipopolysaccharide in 80 to 100% of vaccinees and stimulated specific IgA-secreting lymphocytes in 80 to 100% of vaccinees given a single oral dose of 2 x 10(7) and 5 x 10(8) CFU, chi4073 derivatives containing the Asd+ vector with and without sequences encoding the HBc-pre-S fusion caused occasional febrile reactions at high doses and did not stimulate detectable immune responses to

  8. A Targeted Mutation within the Feline Leukemia Virus (FeLV) Envelope Protein Immunosuppressive Domain To Improve a Canarypox Virus-Vectored FeLV Vaccine

    PubMed Central

    Schlecht-Louf, Géraldine; Mangeney, Marianne; El-Garch, Hanane; Lacombe, Valérie; Poulet, Hervé

    2014-01-01

    We previously delineated a highly conserved immunosuppressive (IS) domain within murine and primate retroviral envelope proteins that is critical for virus propagation in vivo. The envelope-mediated immunosuppression was assessed by the ability of the proteins, when expressed by allogeneic tumor cells normally rejected by engrafted mice, to allow these cells to escape, at least transiently, immune rejection. Using this approach, we identified key residues whose mutation (i) specifically abolishes immunosuppressive activity without affecting the “mechanical” function of the envelope protein and (ii) significantly enhances humoral and cellular immune responses elicited against the virus. The objective of this work was to study the immunosuppressive activity of the envelope protein (p15E) of feline leukemia virus (FeLV) and evaluate the effect of its abolition on the efficacy of a vaccine against FeLV. Here we demonstrate that the FeLV envelope protein is immunosuppressive in vivo and that this immunosuppressive activity can be “switched off” by targeted mutation of a specific amino acid. As a result of the introduction of the mutated envelope sequence into a previously well characterized canarypox virus-vectored vaccine (ALVAC-FeLV), the frequency of vaccine-induced FeLV-specific gamma interferon (IFN-γ)-producing cells was increased, whereas conversely, the frequency of vaccine-induced FeLV-specific interleukin-10 (IL-10)-producing cells was reduced. This shift in the IFN-γ/IL-10 response was associated with a higher efficacy of ALVAC-FeLV against FeLV infection. This study demonstrates that FeLV p15E is immunosuppressive in vivo, that the immunosuppressive domain of p15E can modulate the FeLV-specific immune response, and that the efficacy of FeLV vaccines can be enhanced by inhibiting the immunosuppressive activity of the IS domain through an appropriate mutation. PMID:24198407

  9. A targeted mutation within the feline leukemia virus (FeLV) envelope protein immunosuppressive domain to improve a canarypox virus-vectored FeLV vaccine.

    PubMed

    Schlecht-Louf, Géraldine; Mangeney, Marianne; El-Garch, Hanane; Lacombe, Valérie; Poulet, Hervé; Heidmann, Thierry

    2014-01-01

    We previously delineated a highly conserved immunosuppressive (IS) domain within murine and primate retroviral envelope proteins that is critical for virus propagation in vivo. The envelope-mediated immunosuppression was assessed by the ability of the proteins, when expressed by allogeneic tumor cells normally rejected by engrafted mice, to allow these cells to escape, at least transiently, immune rejection. Using this approach, we identified key residues whose mutation (i) specifically abolishes immunosuppressive activity without affecting the "mechanical" function of the envelope protein and (ii) significantly enhances humoral and cellular immune responses elicited against the virus. The objective of this work was to study the immunosuppressive activity of the envelope protein (p15E) of feline leukemia virus (FeLV) and evaluate the effect of its abolition on the efficacy of a vaccine against FeLV. Here we demonstrate that the FeLV envelope protein is immunosuppressive in vivo and that this immunosuppressive activity can be "switched off" by targeted mutation of a specific amino acid. As a result of the introduction of the mutated envelope sequence into a previously well characterized canarypox virus-vectored vaccine (ALVAC-FeLV), the frequency of vaccine-induced FeLV-specific gamma interferon (IFN-γ)-producing cells was increased, whereas conversely, the frequency of vaccine-induced FeLV-specific interleukin-10 (IL-10)-producing cells was reduced. This shift in the IFN-γ/IL-10 response was associated with a higher efficacy of ALVAC-FeLV against FeLV infection. This study demonstrates that FeLV p15E is immunosuppressive in vivo, that the immunosuppressive domain of p15E can modulate the FeLV-specific immune response, and that the efficacy of FeLV vaccines can be enhanced by inhibiting the immunosuppressive activity of the IS domain through an appropriate mutation.

  10. Peptide Processing Is Critical for T-Cell Memory Inflation and May Be Optimized to Improve Immune Protection by CMV-Based Vaccine Vectors

    PubMed Central

    Blatnik, Renata; Lee, Lian N.; Fischer, Sonja; Borkner, Lisa; Oduro, Jennifer D.; Marandu, Thomas F.; Hoppe, Stephanie; Ruzsics, Zsolt; Sonnemann, Julia K.; Meyer, Christine; Holtappels, Rafaela; Arens, Ramon; Früh, Klaus; Reddehase, Matthias J.; Riemer, Angelika B.; Cicin-Sain, Luka

    2016-01-01

    Cytomegalovirus (CMV) elicits long-term T-cell immunity of unparalleled strength, which has allowed the development of highly protective CMV-based vaccine vectors. Counterintuitively, experimental vaccines encoding a single MHC-I restricted epitope offered better immune protection than those expressing entire proteins, including the same epitope. To clarify this conundrum, we generated recombinant murine CMVs (MCMVs) encoding well-characterized MHC-I epitopes at different positions within viral genes and observed strong immune responses and protection against viruses and tumor growth when the epitopes were expressed at the protein C-terminus. We used the M45-encoded conventional epitope HGIRNASFI to dissect this phenomenon at the molecular level. A recombinant MCMV expressing HGIRNASFI on the C-terminus of M45, in contrast to wild-type MCMV, enabled peptide processing by the constitutive proteasome, direct antigen presentation, and an inflation of antigen-specific effector memory cells. Consequently, our results indicate that constitutive proteasome processing of antigenic epitopes in latently infected cells is required for robust inflationary responses. This insight allows utilizing the epitope positioning in the design of CMV-based vectors as a novel strategy for enhancing their efficacy. PMID:27977791

  11. Alphaviral Vector-Transduced Dendritic Cells are Successful Therapeutic Vaccines against neu-Overexpressing Tumors in Wild-Type Mice

    PubMed Central

    Moran, Timothy P.; Burgents, Joseph E.; Long, Brian; Ferrer, Ivana; Jaffee, Elizabeth M.; Tisch, Roland M.; Johnston, Robert E.; Serody, Jonathan S.

    2009-01-01

    While dendritic cell (DC) vaccines can protect hosts from tumor challenge, their ability to effectively inhibit the growth of established tumors remains indeterminate. Previously, we have shown that human DCs transduced with Venezuelan equine encephalitis virus replicon particles (VRPs) were potent stimulators of antigen-specific T cells in vitro. Therefore, we investigated the ability of VRP-transduced DCs (VRP-DCs) to induce therapeutic immunity in vivo against tumors overexpressing the neu oncoprotein. Transduction of murine DCs with VRPs resulted in high-level transgene expression, DC maturation and secretion of proinflammatory cytokines. Vaccination with VRP-transduced DCs (VRP-DCs) expressing a truncated neu oncoprotein induced robust neu-specific CD8+ T cell and anti-neu IgG responses. Furthermore, a single vaccination with VRP-DCs induced the regression of large established tumors in wild-type mice. Interestingly, depletion of CD4+, but not CD8+, T cells completely abrogated inhibition of tumor growth following vaccination. Taken together, our results demonstrate that VRP-DC vaccines induce potent immunity against established tumors, and emphasize the importance of the generation of both CD4+ T cell and B cell responses for efficient tumor inhibition. These findings provide the rationale for future evaluation VRP-DC vaccines in the clinical setting. PMID:17675184

  12. Alphaviral vector-transduced dendritic cells are successful therapeutic vaccines against neu-overexpressing tumors in wild-type mice.

    PubMed

    Moran, Timothy P; Burgents, Joseph E; Long, Brian; Ferrer, Ivana; Jaffee, Elizabeth M; Tisch, Roland M; Johnston, Robert E; Serody, Jonathan S

    2007-09-04

    While dendritic cell (DC) vaccines can protect hosts from tumor challenge, their ability to effectively inhibit the growth of established tumors remains indeterminate. Previously, we have shown that human DCs transduced with Venezuelan equine encephalitis virus replicon particles (VRPs) were potent stimulators of antigen-specific T cells in vitro. Therefore, we investigated the ability of VRP-transduced DCs (VRP-DCs) to induce therapeutic immunity in vivo against tumors overexpressing the neu oncoprotein. Transduction of murine DCs with VRPs resulted in high-level transgene expression, DC maturation and secretion of proinflammatory cytokines. Vaccination with VRP-DCs expressing a truncated neu oncoprotein induced robust neu-specific CD8(+) T cell and anti-neu IgG responses. Furthermore, a single vaccination with VRP-DCs induced the regression of large established tumors in wild-type mice. Interestingly, depletion of CD4(+), but not CD8(+), T cells completely abrogated inhibition of tumor growth following vaccination. Taken together, our results demonstrate that VRP-DC vaccines induce potent immunity against established tumors, and emphasize the importance of the generation of both CD4(+) T cell and B cell responses for efficient tumor inhibition. These findings provide the rationale for future evaluation of VRP-DC vaccines in the clinical setting.

  13. Vaccine efficacy of live-attenuated virus, whole inactivated virus and alphavirus vectored subunit vaccines against antigenically distinct H3N2 swine influenza A viruses

    USDA-ARS?s Scientific Manuscript database

    Introduction Influenza A virus (IAV) is an important pathogen in swine, and the main intervention strategy is vaccination to induce neutralizing antibodies against the hemagglutinin (HA). Three major antigenic clusters, cyan, red, and green, were identified among H3N2 viruses circulating in pigs in ...

  14. Oral vaccination with a viral vector containing Abeta cDNA attenuates age-related Abeta accumulation and memory deficits without causing inflammation in a mouse Alzheimer model.

    PubMed

    Mouri, Akihiro; Noda, Yukihiro; Hara, Hideo; Mizoguchi, Hiroyuki; Tabira, Takeshi; Nabeshima, Toshitaka

    2007-07-01

    Immunotherapy with Abeta is expected to bring great improvement for Alzheimer disease (AD). However, clinical trials have been suspended because of meningoencephalitics, which accompanied lymphocytic infiltration. We have developed an oral vaccine for AD with a recombinant adeno-associated viral vector carrying Abeta cDNA (AAV/Abeta). The vaccine reduces the amount of Abeta deposited without lymphocytic infiltration in APP transgenic (Tg2576) mice. In the present study, Tg2576 mice showed progressive cognitive impairments in the novel object recognition test, Y-maze test, water maze test, and contextual conditioned fear learning test. A single oral administration of AAV/Abeta to Tg2576 mice at the age of 10 months alleviated progressive cognitive impairment with decreased Abeta deposition, insoluble Abeta, soluble Abeta oligomer (Abeta*56), microglial attraction, and synaptic degeneration induced in the brain regions at the age of 13 months. A histological analysis with hematoxylin and eosin and an immunohistochemical analysis with antibodies against CD3, CD4, CD8, and CD19 suggested there was no lymphocytic infiltration or microhemorrhage in the brain of AAV/Abeta-vaccinated Tg2576 mice at 13 months of age. Taken together, these results suggest that immunotherapy with AAV/Abeta is a safe and effective treatment for AD.

  15. Yellow fever 17D-vectored vaccines expressing Lassa virus GP1 and GP2 glycoproteins provide protection against fatal disease in guinea pigs

    PubMed Central

    Jiang, Xiaohong; Dalebout, Tim J.; Bredenbeek, Peter J.; Carrion, Ricardo; Brasky, Kathleen; Patterson, Jean; Goicochea, Marco; Bryant, Joseph; Salvato, Maria S.; Lukashevich, Igor S.

    2010-01-01

    Yellow Fever (YF) and Lassa Fever (LF) are two prevalent hemorrhagic fevers co-circulating in West Africa and responsible for thousands of deaths annually. The YF vaccine 17D has been used as a vector for the Lassa virus glycoprotein precursor (LASV-GPC) or their subunits, GP1 (attachment glycoprotein) and GP2 (fusion glycoprotein). Cloning shorter inserts, LASV GP1 and GP2, between YF17D E and NS1 genes enhanced genetic stability of recombinant viruses, YF17D/LASV-GP1 and –GP2, in comparison with YF17D/LASV-GPC recombinant. The recombinant viruses were replication competent and properly processed YF and LASV GP proteins in infected cells. YF17D/LASV-GP1&GP2 induced specific CD8+ T cell responses in mice and protected strain 13 guinea pigs against fatal LF. Unlike immunization with live attenuated reassortant vaccine ML29, immunization with YF17D/LASV-GP1&GP2 did not provide sterilizing immunity. This study demonstrates the feasibility of YF17D-based vaccine to control LF in West Africa. PMID:21145373

  16. Induction of CML28-specific cytotoxic T cell responses using co-transfected dendritic cells with CML28 DNA vaccine and SOCS1 small interfering RNA expression vector

    SciTech Connect

    Zhou Hongsheng; Zhang Donghua . E-mail: hanson2008@gmail.com; Wang Yaya; Dai Ming; Zhang Lu; Liu Wenli; Liu Dan; Tan Huo; Huang Zhenqian

    2006-08-18

    CML28 is an attractive target for antigen-specific immunotherapy. SOCS1 represents an inhibitory control mechanism for DC antigen presentation and the magnitude of adaptive immunity. In this study, we evaluated the potential for inducing CML28-specific cytotoxic T lymphocytes (CTL) responses by dendritic cells (DCs)-based vaccination. We constructed a CML28 DNA vaccine and a SOCS1 siRNA vector and then cotransfect monocyte-derived DCs. Flow cytometry analysis showed gene silencing of SOCS1 resulted in higher expressions of costimulative moleculars in DCs. Mixed lymphocyte reaction (MLR) indicated downregulation of SOCS1 stronger capability to stimulate proliferation of responder cell in DCs. The CTL assay revealed transfected DCs effectively induced autologous CML28-specific CTL responses and the lytic activities induced by SOCS1-silenced DCs were significantly higher compared with those induced by SOCS1-expressing DCs. These results in our study indicates gene silencing of SOCS1 remarkably enhanced the cytotoxicity efficiency of CML28 DNA vaccine in DCs.

  17. Yellow fever 17D-vectored vaccines expressing Lassa virus GP1 and GP2 glycoproteins provide protection against fatal disease in guinea pigs.

    PubMed

    Jiang, Xiaohong; Dalebout, Tim J; Bredenbeek, Peter J; Carrion, Ricardo; Brasky, Kathleen; Patterson, Jean; Goicochea, Marco; Bryant, Joseph; Salvato, Maria S; Lukashevich, Igor S

    2011-02-01

    Yellow Fever (YF) and Lassa Fever (LF) are two prevalent hemorrhagic fevers co-circulating in West Africa and responsible for thousands of deaths annually. The YF vaccine 17D has been used as a vector for the Lassa virus glycoprotein precursor (LASV-GPC) or their subunits, GP1 (attachment glycoprotein) and GP2 (fusion glycoprotein). Cloning shorter inserts, LASV-GP1 and -GP2, between YF17D E and NS1 genes enhanced genetic stability of recombinant viruses, YF17D/LASV-GP1 and -GP2, in comparison with YF17D/LASV-GPC recombinant. The recombinant viruses were replication competent and properly processed YF proteins and LASV GP antigens in infected cells. YF17D/LASV-GP1 and -GP2 induced specific CD8+ T cell responses in mice and protected strain 13 guinea pigs against fatal LF. Unlike immunization with live attenuated reassortant vaccine ML29, immunization with YF17D/LASV-GP1 and -GP2 did not provide sterilizing immunity. This study demonstrates the feasibility of YF17D-based vaccine to control LF in West Africa. Copyright © 2010 Elsevier Ltd. All rights reserved.

  18. Potential of auxotrophic Edwardsiella tarda double-knockout mutant as a delivery vector for DNA vaccine in olive flounder (Paralichthys olivaceus).

    PubMed

    Choi, Seung Hyuk; Kim, Ki Hong

    2012-02-15

    To evaluate potential of an auxotrophic Edwardsiella tarda mutant (Δalr Δasd E. tarda) as a delivery vehicle for DNA vaccine in fish, olive flounder (Paralichthys olivaceus) were immunized with the E. tarda mutant harboring plasmids (pG02-ASD-CMV-eGFP) for eukaryotic expression of the enhanced green fluorescent protein (eGFP) gene through either intraperitoneal (i.p.) or oral route, and the expression of eGFP in the internal organs and generation of antibody against eGFP in fish were analyzed. In fish i.p. injected with 2×10(7)CFU/fish of Δalr Δasd E. tarda harboring pG02-ASD-CMV-eGFP, expression of eGFP was detected in liver, kidney, and spleen from 1 day to 28 days post-injection. In fish orally administered with 1×10(9)CFU/fish of the bacteria, the eGFP band was detected in liver, kidney, and spleen from 1 day to 14 days post-administration, whereas, in intestine, the band was detected only at 1 day post-administration. Either oral or i.p. immunization of olive flounder with recombinant E. tarda that carried eGFP-expressing eukaryotic plasmids was successful to induce humoral adaptive immunity against not only E. tarda that was used as a delivery vehicle but also eGFP that was used as the reporter protein of DNA vaccine, suggesting attenuated E. tarda-vectored DNA vaccine has a potential to be used as a combined vaccine against infectious diseases in fish. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Adenovirus vector vaccination induces expansion of memory CD4 T cells with a mucosal homing phenotype that are readily susceptible to HIV-1

    PubMed Central

    Benlahrech, Adel; Harris, Julian; Meiser, Andrea; Papagatsias, Timos; Hornig, Julia; Hayes, Peter; Lieber, Andre; Athanasopoulos, Takis; Bachy, Veronique; Csomor, Eszter; Daniels, Rod; Fisher, Kerry; Gotch, Frances; Seymour, Len; Logan, Karen; Barbagallo, Romina; Klavinskis, Linda; Dickson, George; Patterson, Steven

    2009-01-01

    In the recently halted HIV type 1 (HIV-1) vaccine STEP trial, individuals that were seropositive for adenovirus serotype 5 (Ad5) showed increased rates of HIV-1 infection on vaccination with an Ad5 vaccine. We propose that this was due to activation and expansion of Ad5-specific mucosal-homing memory CD4 T cells. To test this hypothesis, Ad5 and Ad11 antibody titers were measured in 20 healthy volunteers. Dendritic cells (DCs) from these individuals were pulsed with replication defective Ad5 or Ad11 and co-cultured with autologous lymphocytes. Cytokine profiles, proliferative capacity, mucosal migration potential, and susceptibility to HIV infection of the adenovirus-stimulated memory CD4 T cells were measured. Stimulation of T cells from healthy Ad5-seropositive but Ad11-seronegative individuals with Ad5, or serologically distinct Ad11 vectors induced preferential expansion of adenovirus memory CD4 T cells expressing α4β7 integrins and CCR9, indicating a mucosal-homing phenotype. CD4 T-cell proliferation and IFN-γ production in response to Ad stimulation correlated with Ad5 antibody titers. However, Ad5 serostatus did not correlate with total cytokine production upon challenge with Ad5 or Ad11. Expanded Ad5 and Ad11 memory CD4 T cells showed an increase in CCR5 expression and higher susceptibility to infection by R5 tropic HIV-1. This suggests that adenoviral-based vaccination against HIV-1 in individuals with preexisting immunity against Ad5 results in preferential expansion of HIV-susceptible activated CD4 T cells that home to mucosal tissues, increases the number of virus targets, and leads to a higher susceptibility to HIV acquisition. PMID:19918060

  20. Feline Leukemia Virus DNA Vaccine Efficacy Is Enhanced by Coadministration with Interleukin-12 (IL-12) and IL-18 Expression Vectors

    PubMed Central

    Hanlon, Linda; Argyle, David; Bain, Derek; Nicolson, Lesley; Dunham, Stephen; Golder, Matthew C.; McDonald, Michael; McGillivray, Christine; Jarrett, Oswald; Neil, James C.; Onions, David E.

    2001-01-01

    The expectation that cell-mediated immunity is important in the control of feline leukemia virus (FeLV) infection led us to test a DNA vaccine administered alone or with cytokines that favored the development of a Th1 immune response. The vaccine consisted of two plasmids, one expressing the gag/pol genes and the other expressing the env gene of FeLV-A/Glasgow-1. The genetic adjuvants were plasmids encoding the feline cytokines interleukin-12 (IL-12), IL-18, or gamma interferon (IFN-γ). Kittens were immunized by three intramuscular inoculations of the FeLV DNA vaccine alone or in combination with plasmids expressing IFN-γ, IL-12, or both IL-12 and IL-18. Control kittens were inoculated with empty plasmid. Following immunization, anti-FeLV antibodies were not detected in any kitten. Three weeks after the final immunization, the kittens were challenged by the intraperitoneal inoculation of FeLV-A/Glasgow-1 and were then monitored for a further 15 weeks for the presence of virus in plasma and, at the end of the trial, for latent virus in bone marrow. The vaccine consisting of FeLV DNA with the IL-12 and IL-18 genes conferred significant immunity, protecting completely against transient and persistent viremia, and in five of six kittens protecting against latent infection. None of the other vaccines provided significant protection. PMID:11507187

  1. Development of a Recombinant Newcastle Disease Virus VG/GA Strain Infectious Clone as an Enterotropic Vaccine Vector

    USDA-ARS?s Scientific Manuscript database

    The Villegas-Glisson/University of Georgia (VG/GA) vaccine strain of Newcastle disease virus (NDV) is commonly used worldwide to prevent Newcastle disease. The VG/GA strain is thought to preferentially replicate in intestinal tract of chickens and induce local mucosal immunoresponse. In the presen...

  2. Cross-species transfer of viruses: implications for the use of viral vectors in biomedical research, gene therapy and as live-virus vaccines.

    PubMed

    Louz, Derrick; Bergmans, Hans E; Loos, Birgit P; Hoeben, Rob C

    2005-10-01

    All living organisms are continuously exposed to a plethora of viruses. In general, viruses tend to be restricted to the natural host species which they infect. From time to time viruses cross the host-range barrier expanding their host range. However, in very rare cases cross-species transfer is followed by the establishment and persistence of a virus in the new host species, which may result in disease. Recent examples of viruses that have crossed the species barrier from animal reservoirs to humans are hantavirus, haemorrhagic fever viruses, arboviruses, Nipah and Hendra viruses, avian influenza virus (AI), monkeypox virus, and the SARS-associated coronavirus (SARS-CoV). The opportunities for cross-species transfer of mammalian viruses have increased in recent years due to increased contact between humans and animal reservoirs. However, it is difficult to predict when such events will take place since the viral adaptation that is needed to accomplish this is multifactorial and stochastic. Against this background the intensified use of viruses and their genetically modified variants as viral gene transfer vectors for biomedical research, experimental gene therapy and for live-vector vaccines is a cause for concern. This review addresses a number of potential risk factors and their implications for activities with viral vectors from the perspective of cross-species transfer of viruses in nature, with emphasis on the occurrence of host-range mutants resulting from either cell culture or tropism engineering. The issues are raised with the intention to assist in risk assessments for activities with vector viruses.

  3. Time-dependent biodistribution and transgene expression of a recombinant human adenovirus serotype 5-luciferase vector as a surrogate agent for rAd5-FMDV vaccines in cattle

    USDA-ARS?s Scientific Manuscript database

    Replication-defective recombinant adenovirus 5 (rAd5) vectors carrying foot-and-mouth disease virus (FMDV) transgenes elicit a robust immune response to FMDV challenge in cattle; however vaccine function mechanisms are incompletely understood. Recent efforts addressing critical interactions of rAd5 ...

  4. Genetic stability of a recombinant adenovirus vaccine vector seed library expressing human papillomavirus type 16 E6 and E7 proteins.

    PubMed

    Wu, Jie; Chen, Ke-DA; Gao, Meng; Chen, Gang; Jin, Su-Feng; Zhuang, Fang-Cheng; Wu, Xiao-Hong; Jiang, Yun-Shui; Li, Jian-Bo

    2015-04-01

    The aim of the present study was to understand the genetic stability of a master seed bank (MSB) and a working seed bank (WSB) of an adenovirus vector vaccine expressing the human papillomavirus (HPV) type 16 E6 and E7 fusion proteins (Ad-HPV16E6E7). Microscopic examination and viral infectious efficacy were used to measure the infectious titers of the Ad-HPV16E6E7 MSB and WSB. Polymerase chain reaction was used to analyze the stability of the Ad-HPV16E6E7 target gene insertion, while western blot analysis and immunofluorescence were used to assess the expression levels of the Ad-HPV16E6E7 target protein. A C57BL/6 mouse TC-1 tumor cell growth inhibition model was used to evaluate the biological effect of Ad-HPV16E6E7 administration. The infectious titers of the Ad-HPV16E6E7 MSB and WSB were 6.31×10(9) IU/ml and 3.0×10(9) IU/ml, respectively. In addition, the expression levels of the inserted target genes and target proteins were found to be stable. In the mouse TC-1 tumor inhibition analysis, when the virus titers of the Ad-HPV16E6E7 MSB and WSB were 10(9) IU/ml, the tumor inhibition rate was 100%, which was significantly different when compared with the control group (χ(2)MSB=20.00 and χ(2)WSB=20.00; P<0.01). Therefore, the Ad-HPV16E6E7 vaccine seed bank is genetically stable and meets the requirements for vaccine development.

  5. Recombinant Marek's Disease Virus as a Vector-Based Vaccine against Avian Leukosis Virus Subgroup J in Chicken.

    PubMed

    Liu, Yongzhen; Li, Kai; Gao, Yulong; Gao, Li; Zhong, Li; Zhang, Yao; Liu, Changjun; Zhang, Yanping; Wang, Xiaomei

    2016-11-04

    Avian leukosis virus subgroup J (ALV-J) is an immunosuppressive virus that causes considerable economic losses to the chicken industry in China. However, there is currently no effective vaccine to prevent ALV-J infection. In order to reduce the losses caused by ALV-J, we constructed two effective ALV-J vaccines by inserting the ALV-J (strain JL093-1) env or gag+env genes into the US2 gene of the Marek's disease herpesviruses (MDV) by transfection of overlapping fosmid DNAs, creating two recombinant MDVs, rMDV/ALV-gag+env and rMDV/ALV-env. Analysis of cultured chicken embryo fibroblasts infected with the rMDVs revealed that Env and Gag were successfully expressed and that there was no difference in growth kinetics in cells infected with rMDVs compared with that of cells infected with the parent MDV. Chickens vaccinated with either rMDV revealed that positive serum antibodies were induced. Both rMDVs also effectively reduced the rate of positive viremia in chicken flocks challenged with ALV-J. The protective effect provided by rMDV/ALV-env inoculation was slightly stronger than that provided by rMDV/ALV-gag+env. This represents the first study where a potential rMDV vaccine, expressing ALV-J antigenic genes, has been shown to be effective in the prevention of ALV-J. Our study also opens new avenues for the control of MDV and ALV-J co-infection.

  6. Development of an Acid-Resistant Salmonella Typhi Ty21a Attenuated Vector For Improved Oral Vaccine Delivery

    PubMed Central

    Feuille, Catherine M.; Starke, Carly Elizabeth C.; Bhagwat, Arvind A.; Stibitz, Scott; Kopecko, Dennis J.

    2016-01-01

    The licensed oral, live-attenuated bacterial vaccine for typhoid fever, Salmonella enterica serovar Typhi strain Ty21a, has also been utilized as a vaccine delivery platform for expression of diverse foreign antigens that stimulate protection against shigellosis, anthrax, plague, or human papilloma virus. However, Ty21a is acid-labile and, for effective oral immunization, stomach acidity has to be either neutralized with buffer or by-passed with Ty21a in an enteric-coated capsule (ECC). Several studies have shown that efficacy is reduced when Ty21a is administered in an ECC versus as a buffered liquid formulation, the former limiting exposure to GI tract lymphoid tissues. However, the ECC was selected as a more practical delivery format for both packaging/shipping and vaccine administration ease. We have sought to increase Ty21a acid-resistance to allow for removal from the ECC and immune enhancement. To improve Ty21a acid-resistance, glutamate-dependent acid resistance genes (GAD; responsible for Shigella spp. survival at very low pH) were cloned on a multi-copy plasmid (pGad) under a controllable arabinose-inducible promoter. pGad enhanced acid survival of Ty21a by 5 logs after 3 hours at pH 2.5, when cells were pre-grown in arabinose and under conditions that promote an acid-tolerance response (ATR). For genetically 100% stable expression, we inserted the gad genes into the Ty21a chromosome, using a method that allowed for subsequent removal of a selectable antibiotic resistance marker. Further, both bacterial growth curves and survival assays in cultured human monocytes/macrophages suggest that neither the genetic methods employed nor the resulting acid-resistance conferred by expression of the Gad proteins in Ty21a had any effect on the existing attenuation of this vaccine strain. PMID:27673328

  7. Recombinant Marek’s Disease Virus as a Vector-Based Vaccine against Avian Leukosis Virus Subgroup J in Chicken

    PubMed Central

    Liu, Yongzhen; Li, Kai; Gao, Yulong; Gao, Li; Zhong, Li; Zhang, Yao; Liu, Changjun; Zhang, Yanping; Wang, Xiaomei

    2016-01-01

    Avian leukosis virus subgroup J (ALV-J) is an immunosuppressive virus that causes considerable economic losses to the chicken industry in China. However, there is currently no effective vaccine to prevent ALV-J infection. In order to reduce the losses caused by ALV-J, we constructed two effective ALV-J vaccines by inserting the ALV-J (strain JL093-1) env or gag+env genes into the US2 gene of the Marek’s disease herpesviruses (MDV) by transfection of overlapping fosmid DNAs, creating two recombinant MDVs, rMDV/ALV-gag+env and rMDV/ALV-env. Analysis of cultured chicken embryo fibroblasts infected with the rMDVs revealed that Env and Gag were successfully expressed and that there was no difference in growth kinetics in cells infected with rMDVs compared with that of cells infected with the parent MDV. Chickens vaccinated with either rMDV revealed that positive serum antibodies were induced. Both rMDVs also effectively reduced the rate of positive viremia in chicken flocks challenged with ALV-J. The protective effect provided by rMDV/ALV-env inoculation was slightly stronger than that provided by rMDV/ALV-gag+env. This represents the first study where a potential rMDV vaccine, expressing ALV-J antigenic genes, has been shown to be effective in the prevention of ALV-J. Our study also opens new avenues for the control of MDV and ALV-J co-infection. PMID:27827933

  8. Prime-boost vaccination with recombinant H5-fowlpox and Newcastle disease virus vectors affords lasting protection in SPF Muscovy ducks against highly pathogenic H5N1 influenza virus.

    PubMed

    Niqueux, Eric; Guionie, Olivier; Amelot, Michel; Jestin, Véronique

    2013-08-28

    Vaccination protocols were evaluated in one-day old Muscovy ducklings, using an experimental Newcastle disease recombinant vaccine (vNDV-H5) encoding an optimized synthetic haemagglutinin gene from a clade 2.2.1 H5N1 highly pathogenic (HP) avian influenza virus (AIV), either as a single administration or as a boost following a prime inoculation with a fowlpox vectored vaccine (vFP89) encoding a different H5 HP haemagglutinin from an Irish H5N8 strain. These vaccination schemes did not induce detectable levels of serum antibodies in HI test using a clade 2.2.1 H5N1 antigen, and only induced H5 ELISA positive response in less than 10% of vaccinated ducks. However, following challenge against a clade 2.2.1 HPAIV, both protocols afforded full clinical protection at six weeks of age, and full protection against mortality at nine weeks. Only the prime-boost vaccination (vFP89+vNDV-H5) was still fully protecting Muscovy ducks against disease and mortality at 12 weeks of age. Reduction of oropharyngeal shedding levels was also constantly observed from the onset of the follow-up at 2.5 or three days post-infection in vaccinated ducks compared to unvaccinated controls, and was significantly more important for vFP89+vNDV-H5 vaccination than for vNDV-H5 alone. Although the latter vaccine is shown immunogenic in one-day old Muscovy ducks, the present work is original in demonstrating the high efficacy of the successive administration of two different vector vaccines encoding two different H5 in inducing lasting protection (at least similar to the one induced by an inactivated reassortant vaccine, Re-5). In addition, such a prime-boost schedule allows implementation of a DIVA strategy (to differentiate vaccinated from infected ducks) contrary to Re-5, involves easy practice on the field (with injection at the hatchery and mass vaccination later on), and should avoid eventual interference with NDV maternally derived antibodies. Last, the HA insert could be updated according to

  9. Poly ICLC increases the potency of a replication-defective human adenovirus vectored foot-and-mouth disease vaccine

    USDA-ARS?s Scientific Manuscript database

    Foot-and-mouth disease virus (FMDV) causes a highly contagious disease of cloven-hoofed animals. We have previously demonstrated that a replication-defective human adenovirus 5 vector carrying the FMDV capsid coding region of serotype A24 Cruzeiro (Ad5-CI-A24-2B) protects swine and cattle against FM...

  10. Generation of recombinant bacillus Calmette-Guérin and Mycobacterium smegmatis expressing BfpA and intimin as vaccine vectors against enteropathogenic Escherichia coli.

    PubMed

    Vasconcellos, Halyka Luzorio Franzotti; Scaramuzzi, Karina; Nascimento, Ivan Pereira; Da Costa Ferreira, Jorge M; Abe, Cecilia M; Piazza, Roxane M F; Kipnis, Andre; Dias da Silva, Wilmar

    2012-09-07

    Enteropathogenic Escherichia coli (EPEC) is an important cause of diarrhea in children. EPEC adheres to the intestinal epithelium and causes attaching and effacing (A/E) lesions. Recombinant Mycobacterium smegmatis (Smeg) and Mycobacterium bovis BCG strains were constructed to express either BfpA or intimin. The entire bfpA gene and a portion of the intimin gene were amplified by PCR from EPEC genomic DNA and inserted into the pMIP12 vector at the BamHI/KpnI sites. The pMIP_bfpA and pMIP_intimin vectors were introduced separately into Smeg and BCG. Recombinant clones were selected based on kanamycin resistance and designated rSmeg_pMIP_(bfpA or intimin) and rBCG_pMIP_(bfpA or intimin). The expression of bfpA and intimin was detected by Immunoblotting using polyclonal anti-BfpA and anti-intimin antibodies. The immunogenicity of these proteins was assessed in C57BL/6 mice by assaying the feces and serum for the presence of anti-BfpA and anti-intimin IgA and IgG antibodies. TNF-α and INF-γ were produced in vitro by spleen cells from mice immunized with recombinant BfpA, whereas TNF-γ was produced in mice immunized with recombinant intimin. The adhesion of EPEC (E2348/69) to HEp-2 target cells was blocked by IgA or IgG antibodies from mice immunized with recombinant BfpA or intimin but not by antibodies from non-immunized mice. Immunogenic non-infectious vectors containing relevant EPEC virulence genes may be promising vaccine candidates.

  11. Experimental and Field Results Regarding Immunity Induced by a Recombinant Turkey Herpesvirus H5 Vector Vaccine Against H5N1 and Other H5 Highly Pathogenic Avian Influenza Virus Challenges.

    PubMed

    Gardin, Yannick; Palya, Vilmos; Dorsey, Kristi Moore; El-Attrache, John; Bonfante, Francesco; Wit, Sjaak de; Kapczynski, Darrell; Kilany, Walid Hamdy; Rauw, Fabienne; Steensels, Mieke; Soejoedono, Retno D

    2016-05-01

    Vaccination against H5N1 highly pathogenic avian influenza (AI) virus (HPAIV) is one of the possible complementary means available for affected countries to control AI when the disease has become, or with a high risk of becoming, endemic. Efficacy of the vaccination against AI relies essentially, but not exclusively, on the capacity of the vaccine to induce immunity against the targeted virus (which is prone to undergo antigenic variations), as well as its capacity to overcome interference with maternal immunity transmitted by immunized breeding hens to their progeny. This property of the vaccine is a prerequisite for its administration at the hatchery, which assures higher and more reliable vaccine coverage of the populations than vaccination at the farm. A recombinant vector vaccine (Vectormune® AI), based on turkey herpesvirus expressing the hemagglutinin gene of an H5N1 HPAIV as an insert, has been used in several experiments conducted in different research laboratories, as well as in controlled field trials. The results have demonstrated a high degree of homologous and cross protection against different genetic clades of the H5N1 HPAIV. Furthermore, vaccine-induced immunity was not impaired by the presence of passive immunity, but on the contrary, cumulated with it for improved early protection. The demonstrated levels of protection against the different challenge viruses exhibited variations in terms of postchallenge mortality, as well as challenge virus shedding. The data presented here highlight the advantages of this vaccine as a useful and reliable tool to complement biosecurity and sanitary policies for better controlling the disease due to HPAIV of H5 subtypes, when the vaccination is applied as a control measure.

  12. Live attenuated Salmonella enterica serovar Choleraesuis vaccine vector displaying regulated delayed attenuation and regulated delayed antigen synthesis to confer protection against Streptococcus suis in mice.

    PubMed

    Ji, Zhenying; Shang, Jing; Li, Yuan; Wang, Shifeng; Shi, Huoying

    2015-09-11

    Salmonella enterica serotype Choleraesuis (S. Choleraesuis) and Streptococcus suis (S. suis) are important swine pathogens. Development of a safe and effective attenuated S. Choleraesuis vaccine vector would open a new window to prevent and control pig diseases. To achieve this goal, the mannose and arabinose regulated delayed attenuated systems (RDAS), Δpmi and ΔPcrp::TT araC PBADcrp, were introduced into the wild type S. Choleraesuis strain C78-3. We also introduced ΔrelA::araC PBADlacI TT to achieve regulated delayed antigen synthesis and ΔasdA to constitute a balanced-lethal plasmid system. The safety and immunogenicity of the resulted RDAS S. Choleraesuis strain rSC0011 carrying 6-phosphogluconate dehydrogenase (6-PGD) of S. suis serotype 2 (SS2) were evaluated in vitro and in vivo. Compared with the wild type parent strain C78-3 and vaccine strain C500, a live attenuated S. Choleraesuis vaccine licensed for piglet in China, the results showed that the survival curves of the vaccine strain rSC0011 were similar to those of strains C78-3 and C500 at the early stage of infection, but lower than those of C78-3 and higher than those of C500 at the later stage in both porcine alveolar macrophages and peripheral porcine monocytes. The LD50 of the RDAS strains rSC0011 by oral route in mice was close to that of C500 and 10,000-fold higher than that of C78-3. Similar results were achieved by intraperitoneal (i.p.) route, suggesting that the RDAS strains rSC0011 achieved similar attenuation as C500. However, the RDAS strain rSC0011 was superior to C500 in colonization of Peyer's patches. Adult mice orally immunized with strain rSC0011 carrying a plasmid expression 6-phosphogluconate dehydrogenase (6-PGD) gene from SS2 developed strong immune responses against 6-PGD and Salmonella antigens, and conferred high protection against i.p. challenge with SS2.

  13. Development and Evaluation of the Protective Efficacy of Novel Marek's Disease Virus Rispens Vector Vaccines Against Infectious Bursal Disease.

    PubMed

    Ishihara, Yukari; Esaki, Motoyuki; Saitoh, Shuji; Sato, Takanori; Yasuda, Atsushi

    2016-09-01

    Infectious bursal disease (IBD) is a major disease affecting the poultry industry and is caused by infection with IBD virus (IBDV). To develop a novel vaccine to prevent IBD in chickens, recombinant Marek's disease virus Rispens viruses carrying the VP2 gene of IBDV driven by five different promoters (Rispens/IBD) were constructed using homologous recombination and a bacterial artificial chromosome (BAC). Rispens/IBD driven by the chicken beta-actin (Bac) promoter (Rispens/Bac-IBD), Rous sarcoma virus promoter, or simian virus 40 promoter were administered to 1-day-old SPF chicks, and the protective efficacy against IBDV was evaluated by challenging chicks with virulent IBDV. As a result, Rispens/Bac-IBD showed the best protection (87%). Next, we constructed the virus driven by the Bac-derived Coa5 promoter (Rispens/Coa5-IBD) for a secondary in vivo trial using commercial layer chickens since Rispens/Bac-IBD was thought to be genetically unstable. Rispens/Coa5-IBD showed stability in vitro and exhibited better antibody production and protection during challenge against virulent IBDV at both 5 (95%) and 7 wk of age (91%) compared with that of Rispens/Bac-IBD (90% at 5 wk of age and 84% at 7 wk of age). Thus, Rispens/Coa5-IBD may be a novel promising vaccine against IBD and virulent Marek's disease.

  14. Targeting metastatic cancer from the inside: a new generation of targeted gene delivery vectors enables personalized cancer vaccination in situ.

    PubMed

    Gordon, Erlinda M; Levy, John P; Reed, Rebecca A; Petchpud, W Nina; Liu, Liqiong; Wendler, Carlan B; Hall, Frederick L

    2008-10-01

    The advent of pathotropic (disease-seeking) targeting technologies, combined with advanced gene delivery vectors, provides a unique opportunity for the systemic delivery of immunomodulatory cytokine genes to remote sites of cancer metastasis. When injected intravenously, such pathotropic nanoparticles seek out and accumulate selectively at sites of tumor invasion and neo-angiogenesis, resulting in enhanced gene delivery, and thus cytokine production, within the tumor nodules. Used in conjunction with a primary tumoricidal agent (e.g., Rexin-G) that exposes tumor neoantigens, the tumor-targeted immunotherapy vector is intended to promote the recruitment and activation of host immune cells into the metastastic site(s), thereby initiating cancer immunization in situ. In this study, we examine the feasibility of cytokine gene delivery to cancerous lesions in vivo using intravenously administered pathotropically targeted nanoparticles bearing the gene encoding granulocyte/macrophage colony-stimulating factor (GM-CSF; i.e., Reximmune-C). In vitro, transduction of target cancer cells with Reximmune-C resulted in the quantitative production of bioactive and immunoreactive GM-CSF protein. In tumor-bearing nude mice, intravenous infusions of Reximmune-C-induced GM-CSF production by transduced cancer cells and paracrine secretion of the cytokine within the tumor nodules, which promoted the recruitment of host mononuclear cells, including CD40+ B cells and CD86+ dendritic cells, into the tumors. With the first proofs of principle established in preclinical studies, we generated an optimized vector configuration for use in advanced clinical trial designs, and extended the feasibility studies to the clinic. Targeted delivery and localized expression of the GM-CSF transgene was confirmed in a patient with metastatic cancer, as was the recruitment of significant tumor-infiltrating lymphocytes (TILs). Taken together, these studies provide the first demonstrations of cytokine gene

  15. Clinical development of Ebola vaccines

    PubMed Central

    Sridhar, Saranya

    2015-01-01

    The ongoing outbreak of Ebola virus disease in West Africa highlighted the lack of a licensed drug or vaccine to combat the disease and has renewed the urgency to develop a pipeline of Ebola vaccines. A number of different vaccine platforms are being developed by assessing preclinical efficacy in animal models and expediting clinical development. Over 15 different vaccines are in preclinical development and 8 vaccines are now in different stages of clinical evaluation. These vaccines include DNA vaccines, virus-like particles and viral vectors such as live replicating vesicular stomatitis virus (rVSV), human and chimpanzee adenovirus, and vaccinia virus. Recently, in preliminary results reported from the first phase III trial of an Ebola vaccine, the rVSV-vectored vaccine showed promising efficacy. This review charts this rapidly advancing area of research focusing on vaccines in clinical development and discusses the future opportunities and challenges faced in the licensure and deployment of Ebola vaccines. PMID:26668751

  16. Regulation of the activity of an adeno-associated virus vector cancer vaccine administered with synthetic Toll-like receptor agonists.

    PubMed

    Triozzi, Pierre L; Aldrich, Wayne; Ponnazhagan, Selvarangan

    2010-11-23

    Recombinant adeno-associated virus (rAAV) is being tested as a vaccine vector, but the cellular immune responses elicited in animal tumor models have not been completely protective. The adjuvant effects of the TLR7 agonist, imiquimod, and the TLR9 agonist, ODN1826, were tested with rAAV expressing the melanoma antigen, Trp2. Mice immunized with rAAV-TRP2 and either TLR agonist alone generated T-helper-1 antitumor immune responses. Antitumor activity in all experiments was still incomplete. Furthermore, antitumor activity was not achieved when the combination of ODN1826 and imiquimod was used as adjuvant. In vitro, the combination increased IL-10 production by dendritic cells. In vivo, the combination reduced T-helper-1 response and dendritic cell activation and increased myeloid suppressor cells; regulatory T cells were not significantly modulated. Depletion of myeloid derived suppressor cells enhanced the antitumor activity of immunization with rAAV-TRP2 and the imiquimod-ODN1826 combination; depletion of regulatory T cells did not. TLR7 and TLR9 agonists can be used to enhance the immune response to rAAV immunogens, but antagonism can be observed when combined. Suppressor mechanisms, including those mediated by myeloid cells, may negatively regulate the antitumor immune response. Copyright © 2010. Published by Elsevier Ltd.

  17. Adaptation of the Endogenous Salmonella enterica Serovar Typhi clyA-Encoded Hemolysin for Antigen Export Enhances the Immunogenicity of Anthrax Protective Antigen Domain 4 Expressed by the Attenuated Live-Vector Vaccine Strain CVD 908-htrA

    PubMed Central

    Galen, James E.; Zhao, Licheng; Chinchilla, Magaly; Wang, Jin Yuan; Pasetti, Marcela F.; Green, Jeffrey; Levine, Myron M.

    2004-01-01

    Bacterial live-vector vaccines aim to deliver foreign antigens to the immune system and induce protective immune responses, and surface-expressed or secreted antigens are generally more immunogenic than cytoplasmic constructs. We hypothesize that an optimum expression system will use an endogenous export system to avoid the need for large amounts of heterologous DNA encoding additional proteins. Here we describe the cryptic chromosomally encoded 34-kDa cytolysin A hemolysin of Salmonella enterica serovar Typhi (ClyA) as a novel export system for the expression of heterologous antigens in the supernatant of attenuated Salmonella serovar Typhi live-vector vaccine strains. We constructed a genetic fusion of ClyA to the reporter green fluorescent protein and showed that in Salmonella serovar Typhi CVD 908-htrA, the fusion protein retains biological activity in both domains and is exported into the supernatant of an exponentially growing live vector in the absence of detectable bacterial lysis. The utility of ClyA for enhancing the immunogenicity of an otherwise problematic antigen was demonstrated by engineering ClyA fused to the domain 4 (D4) moiety of Bacillus anthracis protective antigen (PA). A total of 11 of 15 mice immunized intranasally with Salmonella serovar Typhi exporting the protein fusion manifested fourfold or greater rises in serum anti-PA immunoglobulin G, compared with only 1 of 16 mice immunized with the live vector expressing cytoplasmic D4 (P = 0.0002). In addition, the induction of PA-specific gamma interferon and interleukin 5 responses was observed in splenocytes. This technology offers exceptional versatility for enhancing the immunogenicity of bacterial live-vector vaccines. PMID:15557633

  18. Systemic immune response and virus persistence after foot-and-mouth disease virus infection of naïve cattle and cattle vaccinated with a homologous adenovirus-vectored vaccine

    SciTech Connect

    Eschbaumer, Michael; Stenfeldt, Carolina; Rekant, Steven I.; Pacheco, Juan M.; Hartwig, Ethan J.; Smoliga, George R.; Kenney, Mary A.; Golde, William T.; Rodriguez, Luis L.; Arzt, Jonathan

    2016-09-15

    In order to investigate host factors associated with the establishment of persistent foot-and-mouth disease virus (FMDV) infection, the systemic response to vaccination and challenge was studied in 47 steers. Eighteen steers that had received a recombinant FMDV A vaccine 2 weeks earlier and 29 non-vaccinated steers were challenged by intra-nasopharyngeal deposition of FMDV A24. For up to 35 days after challenge, host factors including complete blood counts with T lymphocyte subsets, type I/III interferon (IFN) activity, neutralizing and total FMDV-specific antibody titers in serum, as well as antibody-secreting cells (in 6 non-vaccinated animals) were characterized in the context of viral infection dynamics. As a result, vaccination generally induced a strong antibody response. There was a transient peak of FMDV-specific serum IgM in non-vaccinated animals after challenge, while IgM levels in vaccinated animals did not increase further. Both groups had a lasting increase of specific IgG and neutralizing antibody after challenge. Substantial systemic IFN activity in non-vaccinated animals coincided with viremia, and no IFN or viremia was detected in vaccinated animals. After challenge, circulating lymphocytes decreased in non-vaccinated animals, coincident with viremia, IFN activity, and clinical disease, whereas lymphocyte and monocyte counts in vaccinated animals were unaffected by vaccination but transiently increased after challenge. The CD4+/CD8+ T cell ratio in non-vaccinated animals increased during acute infection, driven by an absolute decrease of CD8+ cells. In conclusion, the incidence of FMDV persistence was 61.5 % in non-vaccinated and 54.5 % in vaccinated animals. Overall, the systemic factors examined were not associated with the FMDV carrier/non-carrier divergence; however, significant differences were identified between responses of non-vaccinated and vaccinated cattle.

  19. Systemic immune response and virus persistence after foot-and-mouth disease virus infection of naïve cattle and cattle vaccinated with a homologous adenovirus-vectored vaccine

    DOE PAGES

    Eschbaumer, Michael; Stenfeldt, Carolina; Rekant, Steven I.; ...

    2016-09-15

    In order to investigate host factors associated with the establishment of persistent foot-and-mouth disease virus (FMDV) infection, the systemic response to vaccination and challenge was studied in 47 steers. Eighteen steers that had received a recombinant FMDV A vaccine 2 weeks earlier and 29 non-vaccinated steers were challenged by intra-nasopharyngeal deposition of FMDV A24. For up to 35 days after challenge, host factors including complete blood counts with T lymphocyte subsets, type I/III interferon (IFN) activity, neutralizing and total FMDV-specific antibody titers in serum, as well as antibody-secreting cells (in 6 non-vaccinated animals) were characterized in the context of viralmore » infection dynamics. As a result, vaccination generally induced a strong antibody response. There was a transient peak of FMDV-specific serum IgM in non-vaccinated animals after challenge, while IgM levels in vaccinated animals did not increase further. Both groups had a lasting increase of specific IgG and neutralizing antibody after challenge. Substantial systemic IFN activity in non-vaccinated animals coincided with viremia, and no IFN or viremia was detected in vaccinated animals. After challenge, circulating lymphocytes decreased in non-vaccinated animals, coincident with viremia, IFN activity, and clinical disease, whereas lymphocyte and monocyte counts in vaccinated animals were unaffected by vaccination but transiently increased after challenge. The CD4+/CD8+ T cell ratio in non-vaccinated animals increased during acute infection, driven by an absolute decrease of CD8+ cells. In conclusion, the incidence of FMDV persistence was 61.5 % in non-vaccinated and 54.5 % in vaccinated animals. Overall, the systemic factors examined were not associated with the FMDV carrier/non-carrier divergence; however, significant differences were identified between responses of non-vaccinated and vaccinated cattle.« less

  20. Systemic immune response and virus persistence after foot-and-mouth disease virus infection of naïve cattle and cattle vaccinated with a homologous adenovirus-vectored vaccine.

    PubMed

    Eschbaumer, Michael; Stenfeldt, Carolina; Rekant, Steven I; Pacheco, Juan M; Hartwig, Ethan J; Smoliga, George R; Kenney, Mary A; Golde, William T; Rodriguez, Luis L; Arzt, Jonathan

    2016-09-15

    In order to investigate host factors associated with the establishment of persistent foot-and-mouth disease virus (FMDV) infection, the systemic response to vaccination and challenge was studied in 47 steers. Eighteen steers that had received a recombinant FMDV A vaccine 2 weeks earlier and 29 non-vaccinated steers were challenged by intra-nasopharyngeal deposition of FMDV A24. For up to 35 days after challenge, host factors including complete blood counts with T lymphocyte subsets, type I/III interferon (IFN) activity, neutralizing and total FMDV-specific antibody titers in serum, as well as antibody-secreting cells (in 6 non-vaccinated animals) were characterized in the context of viral infection dynamics. Vaccination generally induced a strong antibody response. There was a transient peak of FMDV-specific serum IgM in non-vaccinated animals after challenge, while IgM levels in vaccinated animals did not increase further. Both groups had a lasting increase of specific IgG and neutralizing antibody after challenge. Substantial systemic IFN activity in non-vaccinated animals coincided with viremia, and no IFN or viremia was detected in vaccinated animals. After challenge, circulating lymphocytes decreased in non-vaccinated animals, coincident with viremia, IFN activity, and clinical disease, whereas lymphocyte and monocyte counts in vaccinated animals were unaffected by vaccination but transiently increased after challenge. The CD4(+)/CD8(+) T cell ratio in non-vaccinated animals increased during acute infection, driven by an absolute decrease of CD8(+) cells. The incidence of FMDV persistence was 61.5 % in non-vaccinated and 54.5 % in vaccinated animals. Overall, the systemic factors examined were not associated with the FMDV carrier/non-carrier divergence; however, significant differences were identified between responses of non-vaccinated and vaccinated cattle.

  1. Impact of fowlpox-vectored Mycoplasma gallisepticum vaccine Vectormune® FP MG on layer hen egg production and egg quality parameters

    USDA-ARS?s Scientific Manuscript database

    This study was conducted to determine the impact of vaccination with Vectormune®FP MG on egg production and egg quality characteristics of white leghorn hens. Due to questions of the efficacy of this vaccine in preventing M. gallisepticum mediated pathology, the ability of this vaccine to protect a...

  2. Development of a novel, guinea pig-specific IFN-γ ELISPOT assay and characterization of guinea pig cytomegalovirus GP83-specific cellular immune responses following immunization with a modified vaccinia virus Ankara (MVA)-vectored GP83 vaccine.

    PubMed

    Gillis, Peter A; Hernandez-Alvarado, Nelmary; Gnanandarajah, Josephine S; Wussow, Felix; Diamond, Don J; Schleiss, Mark R

    2014-06-30

    The guinea pig (Cavia porcellus) provides a useful animal model for studying the pathogenesis of many infectious diseases, and for preclinical evaluation of vaccines. However, guinea pig models are limited by the lack of immunological reagents required for characterization and quantification of antigen-specific T cell responses. To address this deficiency, an enzyme-linked immunospot (ELISPOT) assay for guinea pig interferon (IFN)-γ was developed to measure antigen/epitope-specific T cell responses to guinea pig cytomegalovirus (GPCMV) vaccines. Using splenocytes harvested from animals vaccinated with a modified vaccinia virus Ankara (MVA) vector encoding the GPCMV GP83 (homolog of human CMV pp65 [gpUL83]) protein, we were able to enumerate and map antigen-specific responses, both in vaccinated as well as GPCMV-infected animals, using a panel of GP83-specific peptides. Several potential immunodominant GP83-specific peptides were identified, including one epitope, LGIVHFFDN, that was noted in all guinea pigs that had a detectable CD8+ response to GP83. Development of a guinea pig IFN-γ ELISPOT should be useful in characterization of additional T cell-specific responses to GPCMV, as well as other pathogens. This information in turn can help focus future experimental evaluation of immunization strategies, both for GPCMV as well as for other vaccine-preventable illnesses studied in the guinea pig model.

  3. Development of a novel, guinea pig-specific IFN-γ ELISPOT assay and characterization of guinea pig cytomegalovirus GP83-specific cellular immune responses following immunization with a modified vaccinia virus Ankara (MVA)-vectored GP83 vaccine

    PubMed Central

    Gillis, Peter A.; Hernandez-Alvarado, Nelmary; Gnanandarajah, Josephine S.; Wussow, Felix; Diamond, Don J.; Schleiss, Mark R.

    2014-01-01

    The guinea pig (Cavia porcellus) provides a useful animal model for studying the pathogenesis of many infectious diseases, and for preclinical evaluation of vaccines. However, guinea pig models are limited by the lack of immunological reagents required for characterization and quantification of antigen-specific T cell responses. To address this deficiency, an enzyme-linked immunospot (ELISPOT) assay for guinea pig interferon (IFN)-γ was developed to measure antigen/epitope-specific T cell responses to guinea pig cytomegalovirus (GPCMV) vaccines. Using splenocytes harvested from animals vaccinated with a modified vaccinia virus Ankara (MVA) vector encoding the GPCMV GP83 (homolog of human CMV pp65 [gpUL83]) protein, we were able to enumerate and map antigen-specific responses, both in vaccinated as well as GPCMV-infected animals, using a panel of GP83-specific peptides. Several potential immunodominant GP83-specific peptides were identified, including one epitope, LGIVHFFDN, that was noted in all guinea pigs that had a detectable CD8+ response to GP83. Development of a guinea pig IFN-γ ELISPOT should be useful in characterization of additional T cell-specific responses to GPCMV, as well as other pathogens. This information in turn can help focus future experimental evaluation of immunization strategies, both for GPCMV as well as for other vaccine-preventable illnesses studied in the guinea pig model. PMID:24856783

  4. Alphavirus-Based Vaccines.

    PubMed

    Lundstrom, Kenneth

    2016-01-01

    Alphavirus vectors based on Semliki Forest virus, Sindbis virus, and Venezuelan equine encephalitis virus have been widely applied for vaccine development. Naked RNA replicons, recombinant viral particles, and layered DNA vectors have been subjected to immunization in preclinical animal models with antigens for viral targets and tumor antigens. Moreover, a limited number of clinical trials have been conducted in humans. Vaccination with alphavirus vectors has demonstrated efficient immune responses and has showed protection against challenges with lethal doses of virus and tumor cells, respectively. Moreover, vaccines have been developed against alphaviruses causing epidemics such as Chikungunya virus.

  5. One-prime multi-boost strategy immunization with recombinant DNA, adenovirus, and MVA vector vaccines expressing HPV16 L1 induces potent, sustained, and specific immune response in mice.

    PubMed

    Li, Li-Li; Wang, He-Rong; Zhou, Zhi-Yi; Luo, Jing; Xiao, Xiang-Qian; Wang, Xiao-Li; Li, Jin-Tao; Zhou, Yu-Bai; Zeng, Yi

    2016-04-01

    Human papillomavirus (HPV) is associated with various human diseases, including cancer, and developing vaccines is a cost-efficient strategy to prevent HPV-related disease. The major capsid protein L1, which an increasing number of studies have confirmed is typically expressed early in infection, is a promising antigen for such a vaccine, although the E6 and E7 proteins have been characterized more extensively. Thus, the L1 gene from HPV16 was inserted into a recombinant vector, AdHu5, and MVA viral vectors, and administered by prime-boost immunization. Virus-like particles were used as control antigens. Our results indicate that prime-boost immunization with heterologous vaccines induced robust and sustained cellular and humoral response specific to HPV16 L1. In particular, sera obtained from mice immunized with DNA + DNA + Ad + MVA had excellent antitumor activity in vivo. However, the data also confirm that virus-like particles can only elicit low levels cellular immunity and not be long-lasting, and are therefore unsuitable for treatment of existing HPV infections.

  6. Rabies vaccine. Developments employing molecular biology methods.

    PubMed

    Paolazzi, C C; Pérez, O; De Filippo, J

    1999-04-01

    Rabies vaccines produced by means of molecular biology are described. Recombinant vaccines employing either viruses as vectors (vaccinia, adenovirus, poxvirus, baculovirus, plant viruses) or a plasmid vector carrying the rabies virus glycoprotein gene are discussed. Synthetic peptide technology directed to rabies vaccine production is also presented.

  7. Transfer of Anti-Rotavirus Antibodies during Pregnancy and in Milk Following Maternal Vaccination with a Herpes Simplex Virus Type-1 Amplicon Vector

    PubMed Central

    Meier, Anita F.; Suter, Mark; Schraner, Elisabeth M.; Humbel, Bruno M.; Tobler, Kurt; Ackermann, Mathias; Laimbacher, Andrea S.

    2017-01-01

    Rotaviruses (RVs) are important enteric pathogens of newborn humans and animals, causing diarrhea and in rare cases death, especially in very young individuals. Rotavirus vaccines presently used are modified live vaccines that lack complete biological safety. Previous work from our laboratory suggested that vaccines based on in situ produced, non-infectious rotavirus-like particles (RVLPs) are efficient while being entirely safe. However, using either vaccine, active mucosal immunization cannot induce protective immunity in newborns due to their immature immune system. We therefore hypothesized that offspring from vaccinated dams are passively immunized either by transfer of maternal antibodies during pregnancy or by taking up antibodies from milk. Using a codon optimized polycistronic gene expression cassette packaged into herpesvirus particles, the simultaneous expression of the RV capsid genes led to the intracellular formation of RVLPs in various cell lines. Vaccinated dams developed a strong RV specific IgG antibody response determined in sera and milk of both mother and pups. Moreover, sera of naïve pups nursed by vaccinated dams also had RV specific antibodies suggesting a lactogenic transfer of antibodies. Although full protection of pups was not achieved in this mouse model, our observations are important for the development of improved vaccines against RV in humans as well as in various animal species. PMID:28212334

  8. Transfer of Anti-Rotavirus Antibodies during Pregnancy and in Milk Following Maternal Vaccination with a Herpes Simplex Virus Type-1 Amplicon Vector.

    PubMed

    Meier, Anita F; Suter, Mark; Schraner, Elisabeth M; Humbel, Bruno M; Tobler, Kurt; Ackermann, Mathias; Laimbacher, Andrea S

    2017-02-16

    Rotaviruses (RVs) are important enteric pathogens of newborn humans and animals, causing diarrhea and in rare cases death, especially in very young individuals. Rotavirus vaccines presently used are modified live vaccines that lack complete biological safety. Previous work from our laboratory suggested that vaccines based on in situ produced, non-infectious rotavirus-like particles (RVLPs) are efficient while being entirely safe. However, using either vaccine, active mucosal immunization cannot induce protective immunity in newborns due to their immature immune system. We therefore hypothesized that offspring from vaccinated dams are passively immunized either by transfer of maternal antibodies during pregnancy or by taking up antibodies from milk. Using a codon optimized polycistronic gene expression cassette packaged into herpesvirus particles, the simultaneous expression of the RV capsid genes led to the intracellular formation of RVLPs in various cell lines. Vaccinated dams developed a strong RV specific IgG antibody response determined in sera and milk of both mother and pups. Moreover, sera of naïve pups nursed by vaccinated dams also had RV specific antibodies suggesting a lactogenic transfer of antibodies. Although full protection of pups was not achieved in this mouse model, our observations are important for the development of improved vaccines against RV in humans as well as in various animal species.

  9. Biological characterization of a serotype 1 Marek’s disease virus-vectored Bi-valent 4 vaccine for infectious laryngotracheitis and Marek’s disease

    USDA-ARS?s Scientific Manuscript database

    Laryngotracheitis (LT) is a highly contagious respiratory disease of chickens that produces significant economic losses to the poultry industry. Traditionally LT has been controlled by administration of modified live vaccines. In recent years, the use of recombinant DNA-derived vaccines using turkey...

  10. Newcastle Disease Virus-Vectored H7 and H5 Live Vaccines Protect Chickens from Challenge with H7N9 or H5N1 Avian Influenza Viruses

    PubMed Central

    Liu, Qinfang; Mena, Ignacio; Ma, Jingjiao; Bawa, Bhupinder; Krammer, Florian; Lyoo, Young S.; Lang, Yuekun; Morozov, Igor; Mahardika, Gusti Ngurah; Ma, Wenjun

    2015-01-01

    Sporadic human infections by a novel H7N9 virus occurred over a large geographic region in China. In this study, we show that Newcastle disease virus (NDV)-vectored H7 (NDV-H7) and NDV-H5 vaccines are able to induce antibodies with high hemagglutination inhibition (HI) titers and completely protect chickens from challenge with the novel H7N9 or highly pathogenic H5N1 viruses, respectively. Notably, a baculovirus-expressed H7 protein failed to protect chickens from H7N9 virus infection. PMID:25926639

  11. Newcastle Disease Virus-Vectored H7 and H5 Live Vaccines Protect Chickens from Challenge with H7N9 or H5N1 Avian Influenza Viruses.

    PubMed

    Liu, Qinfang; Mena, Ignacio; Ma, Jingjiao; Bawa, Bhupinder; Krammer, Florian; Lyoo, Young S; Lang, Yuekun; Morozov, Igor; Mahardika, Gusti Ngurah; Ma, Wenjun; García-Sastre, Adolfo; Richt, Juergen A

    2015-07-01

    Sporadic human infections by a novel H7N9 virus occurred over a large geographic region in China. In this study, we show that Newcastle disease virus (NDV)-vectored H7 (NDV-H7) and NDV-H5 vaccines are able to induce antibodies with high hemagglutination inhibition (HI) titers and completely protect chickens from challenge with the novel H7N9 or highly pathogenic H5N1 viruses, respectively. Notably, a baculovirus-expressed H7 protein failed to protect chickens from H7N9 virus infection.

  12. Systemic immune response and virus persistence after foot-and-mouth disease virus infection of naïve cattle and cattle vaccinated with a homologous adenovirus-vectored vaccine

    USDA-ARS?s Scientific Manuscript database

    In order to investigate host factors associated with the establishment of persistent foot-and-mouth disease virus (FMDV) infection, the systemic immune response to vaccination and challenge was studied in 47 Holstein steers. Eighteen steers which had received one dose of recombinant FMDV A vaccine t...

  13. ChAd63-MVA–vectored Blood-stage Malaria Vaccines Targeting MSP1 and AMA1: Assessment of Efficacy Against Mosquito Bite Challenge in Humans

    PubMed Central

    Sheehy, Susanne H; Duncan, Christopher JA; Elias, Sean C; Choudhary, Prateek; Biswas, Sumi; Halstead, Fenella D; Collins, Katharine A; Edwards, Nick J; Douglas, Alexander D; Anagnostou, Nicholas A; Ewer, Katie J; Havelock, Tom; Mahungu, Tabitha; Bliss, Carly M; Miura, Kazutoyo; Poulton, Ian D; Lillie, Patrick J; Antrobus, Richard D; Berrie, Eleanor; Moyle, Sarah; Gantlett, Katherine; Colloca, Stefano; Cortese, Riccardo; Long, Carole A; Sinden, Robert E; Gilbert, Sarah C; Lawrie, Alison M; Doherty, Tom; Faust, Saul N; Nicosia, Alfredo; Hill, Adrian VS; Draper, Simon J

    2012-01-01

    The induction of cellular immunity, in conjunction with antibodies, may be essential for vaccines to protect against blood-stage infection with the human malaria parasite Plasmodium falciparum. We have shown that prime-boost delivery of P. falciparum blood-stage antigens by chimpanzee adenovirus 63 (ChAd63) followed by the attenuated orthopoxvirus MVA is safe and immunogenic in healthy adults. Here, we report on vaccine efficacy against controlled human malaria infection delivered by mosquito bites. The blood-stage malaria vaccines were administered alone, or together (MSP1+AMA1), or with a pre-erythrocytic malaria vaccine candidate (MSP1+ME-TRAP). In this first human use of coadministered ChAd63-MVA regimes, we demonstrate immune interference whereby responses against merozoite surface protein 1 (MSP1) are dominant over apical membrane antigen 1 (AMA1) and ME-TRAP. We also show that induction of strong cellular immunity against MSP1 and AMA1 is safe, but does not impact on parasite growth rates in the blood. In a subset of vaccinated volunteers, a delay in time to diagnosis was observed and sterilizing protection was observed in one volunteer coimmunized with MSP1+AMA1—results consistent with