The antitumor immune responses induced by nanoemulsion-encapsulated MAGE1-HSP70/SEA complex protein vaccine following different administration routes.

PubMed

Ge, Wei; Hu, Pei-Zhen; Huang, Yang; Wang, Xiao-Ming; Zhang, Xiu-Min; Sun, Yu-Jing; Li, Zeng-Shan; Si, Shao-Yan; Sui, Yan-Fang

2009-10-01

Our previous study showed that nanoemulsion-encapsulated MAGE1-HSP70/SEA (MHS) complex protein vaccine elicited MAGE-1 specific immune response and antitumor effects against MAGE-1-expressing tumor and nanoemulsion is a useful vehicle with possible important implications for cancer biotherapy. The purpose of this study was to compare the immune responses induced by nanoemulsion-encapsulated MAGE1-HSP70 and SEA as NE(MHS) vaccine following different administration routes and to find out the new and effective immune routes. Nanoemulsion vaccine was prepared using magnetic ultrasound methods. C57BL/6 mice were immunized with NE(MHS) via po., i.v., s.c. or i.p., besides mice s.c. injected with PBS or NE(-) as control. The cellular immunocompetence was detected by ELISpot assay and LDH release assay. The therapeutic and tumor challenge assay were also examined. The results showed that the immune responses against MAGE-1 expressing murine tumors elicited by NE(MHS) via 4 different routes were approximately similar and were all stronger than that elicited by PBS or NE(-), suggesting that this novel nanoemulsion carrier can exert potent antitumor immunity against antigens encapsulated in it. Especially, the present results indicated that nanoemulsion vaccine adapted to administration via different routes including peroral, and may have broader applications in the future.

Evaluation of cell-mediated immune responses against porcine circovirus type 2 (PCV2) Cap and Rep proteins after vaccination with a commercial PCV2 sub-unit vaccine.

PubMed

Fort, Maria; Sibila, Marina; Nofrarías, Miquel; Pérez-Martín, Eva; Olvera, Alex; Mateu, Enric; Segalés, Joaquim

2012-11-15

This study investigated the development of cellular immunity to Porcine circovirus type 2 (PCV2) Cap and Rep proteins in pigs vaccinated with a commercial PCV2 genotype a (PCV2a) based sub-unit vaccine, before and after a heterologous challenge with a PCV2b isolate. At three weeks of age, 20 pigs were inoculated intramuscularly with either the vaccine product (V group, n=9) or phosphate buffered saline solution (PBS) (NV group, n=11). Three weeks after vaccination, pigs were challenged intranasally with PCV2b (V-C and NV-C groups) or PBS (V-NC and NV-NC groups). None of the pigs developed clinical signs during the whole experiment, but all NV-C and 3/5 V-C pigs developed viraemia. Vaccination induced the development IFN-γ-secreting cells in response to the Cap protein of PCV2, which appeared three weeks post-vaccination and increased after challenge. By that time, no significant differences were detected on PCV2 antibody titres between vaccinated and non-vaccinated pigs, although there were significant differences on day 7 post-challenge. PCV2-inoculation induced a cellular response against the Rep protein. Such response was significantly reduced or even absent in PCV2-inoculated pigs that were previously vaccinated (V-C group), presumably as a result of a lower PCV2 replication in vaccinated animals compared to non-vaccinated ones. Copyright © 2012 Elsevier B.V. All rights reserved.

Oral Vaccination with a DNA Vaccine Encoding Capsid Protein of Duck Tembusu Virus Induces Protection Immunity

PubMed Central

Shen, Haoyue; Jia, Renyong; Wang, Mingshu; Chen, Shun; Zhu, Dekang; Liu, Mafeng; Zhao, Xinxin; Yang, Qiao; Wu, Ying; Liu, Yunya; Zhang, Ling; Yin, Zhongqiong; Jing, Bo

2018-01-01

The emergence of duck tembusu virus (DTMUV), a new member of the Flavivirus genus, has caused great economical loss in the poultry industry in China. Since the outbreak and spread of DTMUV is hard to control in a clinical setting, an efficient and low-cost oral delivery DNA vaccine SL7207 (pVAX1-C) based on the capsid protein of DTMUV was developed and evaluated in this study. The antigen capsid protein was expressed from the DNA vaccine SL7207 (pVAX1-C), both in vitro and in vivo. The humoral and cellular immune responses in vivo were observed after oral immunization with the SL7207 (pVAX1-C) DNA vaccine. High titers of the specific antibody against the capsid protein and the neutralizing antibody against the DTMUV virus were both detected after inoculation. The ducks were efficiently protected from lethal DTMUV exposure by the SL7207 (pVAX1-C) vaccine in this experiment. Taken together, we demonstrated that the capsid protein of DTMUV possesses a strong immunogenicity against the DTMUV infection. Moreover, an oral delivery of the DNA vaccine SL7207 (pVAX1-C) utilizing Salmonella SL7207 was an efficient way to protect the ducks against DTMUV infection and provides an economic and fast vaccine delivery strategy for a large scale clinical use. PMID:29642401

Candidate mosaic proteins for a pan-filoviral cytotoxic T-Cell lymphocyte vaccine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fenimore, Paul W; Fischer, William M; Kuiken, Carla

The extremely high fatality rates of many filovirus (FILV) strains the recurrent but rarely identified origin of human epidemics, the only partly identified viral reservoirs and the continuing non-human primate epizootics in Africa make a broadly-protective filovirus vaccine highly desirable. Cytotoxic T-cells (CTL) have been shown to be protective in mice, guinea pigs and non-human primates. In murine models the cytotoxic T-cell epitopes that are protective against Ebola virus have been mapped and in non-human primates CTL-mediated protection between viral strains (John Dye: specify) has been demonstrated using two filoviral proteins, nucleoprotein (NP) and glycoprotein (GP). These immunological results suggestmore » that the CTL avenue of immunity deserves consideration for a vaccine. The poorly-understood viral reservoirs means that it is difficult to predict what strains are likely to cause epidemics. Thus, there is a premium on developing a pan-filoviral vaccine. The genetic diversity of FILV is large, roughly the same scale as human immunodeficiency virus (HIV). This presents a serious challenge for the vaccine designer because a traditional vaccine aspiring to pan-filoviral coverage is likely to require the inclusion of many antigenic reagents. A recent method for optimizing cytotoxic T-cell lymphocyte epitope coverage with mosaic antigens was successful in improving potential CTL epitope coverage against HIV and may be useful in the context of very different viruses, such as the filoviruses discussed here. Mosaic proteins are recombinants composed of fragments of wild-type proteins joined at locations resulting in exclusively natural k-mers, 9 {le} k {le} 15, and having approximately the same length as the wild-type proteins. The use of mosaic antigens is motivated by three conjectures: (1) optimizing a mosaic protein to maximize coverage of k-mers found in a set of reference proteins will give better odds of including broadly-protective CTL epitopes in a

Liposomes containing recombinant E protein vaccine against duck Tembusu virus in ducks.

PubMed

Ma, Tengfei; Liu, Yongxia; Cheng, Jia; Liu, Yanhan; Fan, Wentao; Cheng, Ziqiang; Niu, Xudong; Liu, Jianzhu

2016-04-27

To obtain an effective vaccine candidate against duck Tembusu viral (DTMUV) disease which causes egg-drop and great economical loss in the Chinese duck industry, liposome vaccines containing recombinant E protein were prepared and assessed in this study. The recombinant plasmid (PET28a-E) was constructed and transformed into BL21 (DE3) cells to produce E proteins. The recombinant E proteins were purified and entrapped by liposomes through reverse-phase evaporation. Eighty-four cherry valley ducks were randomly divided into seven groups and inoculated intramuscularly at one- or seven-day-old with liposomes-E protein or Freund's adjuvant-E protein vaccine. Blood samples were collected from the first week to the tenth week for serum antibody, plasma for viremia, as well as oropharyngeal and cloacal swabs for virus shedding analyses after being challenged with a 10(2.4) 50% tissue culture infective dose (TCID50) of duck Tembusu virus. Results showed that serum antibody level of the liposomes vaccine was higher than the Freund's adjuvant vaccine, and inoculating twice was superior to once; furthermore, the viremia and virus shedding tests also proved that the liposomes vaccine can provide complete protection against DTMUV challenge. These results demonstrated that the liposomes-E protein vaccine could be used as a potential candidate vaccine to prevent DTMUV infection in ducks. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Library of Plasmodium vivax Recombinant Merozoite Proteins Reveals New Vaccine Candidates and Protein-Protein Interactions

PubMed Central

Hostetler, Jessica B.; Sharma, Sumana; Bartholdson, S. Josefin; Wright, Gavin J.; Fairhurst, Rick M.; Rayner, Julian C.

2015-01-01

Background A vaccine targeting Plasmodium vivax will be an essential component of any comprehensive malaria elimination program, but major gaps in our understanding of P. vivax biology, including the protein-protein interactions that mediate merozoite invasion of reticulocytes, hinder the search for candidate antigens. Only one ligand-receptor interaction has been identified, that between P. vivax Duffy Binding Protein (PvDBP) and the erythrocyte Duffy Antigen Receptor for Chemokines (DARC), and strain-specific immune responses to PvDBP make it a complex vaccine target. To broaden the repertoire of potential P. vivax merozoite-stage vaccine targets, we exploited a recent breakthrough in expressing full-length ectodomains of Plasmodium proteins in a functionally-active form in mammalian cells and initiated a large-scale study of P. vivax merozoite proteins that are potentially involved in reticulocyte binding and invasion. Methodology/Principal Findings We selected 39 P. vivax proteins that are predicted to localize to the merozoite surface or invasive secretory organelles, some of which show homology to P. falciparum vaccine candidates. Of these, we were able to express 37 full-length protein ectodomains in a mammalian expression system, which has been previously used to express P. falciparum invasion ligands such as PfRH5. To establish whether the expressed proteins were correctly folded, we assessed whether they were recognized by antibodies from Cambodian patients with acute vivax malaria. IgG from these samples showed at least a two-fold change in reactivity over naïve controls in 27 of 34 antigens tested, and the majority showed heat-labile IgG immunoreactivity, suggesting the presence of conformation-sensitive epitopes and native tertiary protein structures. Using a method specifically designed to detect low-affinity, extracellular protein-protein interactions, we confirmed a predicted interaction between P. vivax 6-cysteine proteins P12 and P41, further

Membrane and envelope virus proteins co-expressed as lysosome associated membrane protein (LAMP) fused antigens: a potential tool to develop DNA vaccines against flaviviruses.

PubMed

Dhalia, Rafael; Maciel, Milton; Cruz, Fábia S P; Viana, Isabelle F T; Palma, Mariana L; August, Thomas; Marques, Ernesto T A

2009-12-01

Vaccination is the most practical and cost-effective strategy to prevent the majority of the flavivirus infection to which there is an available vaccine. However, vaccines based on attenuated virus can potentially promote collateral side effects and even rare fatal reactions. Given this scenario, the development of alternative vaccination strategies such as DNA-based vaccines encoding specific flavivirus sequences are being considered. Endogenous cytoplasmic antigens, characteristically plasmid DNA-vaccine encoded, are mainly presented to the immune system through Major Histocompatibility Complex class I - MHC I molecules. The MHC I presentation via is mostly associated with a cellular cytotoxic response and often do not elicit a satisfactory humoral response. One of the main strategies to target DNA-encoded antigens to the MHC II compartment is expressing the antigen within the Lysosome-Associated Membrane Protein (LAMP). The flavivirus envelope protein is recognized as the major virus surface protein and the main target for neutralizing antibodies. Different groups have demonstrated that co-expression of flavivirus membrane and envelope proteins in mammalian cells, fused with the carboxyl-terminal of LAMP, is able to induce satisfactory levels of neutralizing antibodies. Here we reviewed the use of the envelope flavivirus protein co-expression strategy as LAMP chimeras with the aim of developing DNA vaccines for dengue, West Nile and yellow fever viruses.

Potency assay design for adjuvanted recombinant proteins as malaria vaccines.

PubMed

Giersing, Birgitte K; Dubovsky, Filip; Saul, Allan; Denamur, Francoise; Minor, Philip; Meade, Bruce

2006-05-15

Many licensed vaccines are composed of live, attenuated or inactivated whole-cell microorganisms, or they comprise purified components from whole-cell extracts or culture supernatants. For some diseases, pathology is fairly well understood, and there may be known correlates of protection that provide obvious parameters for assessment of vaccine potency. However, this is not always the case, and some effective vaccines are routinely used even though the mechanisms or correlates of protection are unknown. Some more modern vaccine approaches employ purified recombinant proteins, based on molecules that appear on the surface of the pathogen. This is one of the strategies that has been adopted in the quest to develop a malaria vaccine. Use of these parasite antigens as vaccine candidates is supported by substantial epidemiological data, and some have demonstrated the ability to elicit protective responses in animal models of malaria infection. However, there is as yet no immunological correlate of protection and no functional assays or animal models that have demonstrated the ability to predict efficacy in humans. There is little precedence for the most appropriate and practical method for assessing potency of vaccines based on these recombinant molecules for malaria vaccines. This is likely because the majority of malaria vaccine candidates have only recently entered clinical evaluation. The PATH Malaria Vaccine Initiative (MVI) convened a panel with expertise in potency assay design from industry, governmental institutions, and regulatory bodies to discuss and review the rationale, available methods, and best approaches for assessing the potency of recombinant proteins, specifically for their use as malarial vaccines. The aim of this meeting was to produce a discussion document on the practical potency assessment of recombinant protein malaria vaccines, focusing on early phase potency assay development.

Characterization of antibody responses to combinations of a dengue virus type 2 DNA vaccine and two dengue virus type 2 protein vaccines in rhesus macaques.

PubMed

Simmons, Monika; Porter, Kevin R; Hayes, Curtis G; Vaughn, David W; Putnak, Robert

2006-10-01

We evaluated three nonreplicating dengue virus type 2 (DENV-2) vaccines: (i) a DNA vaccine containing the prM-E gene region (D), (ii) a recombinant subunit protein vaccine containing the B domain (i.e., domain III) of the E protein as a fusion with the Escherichia coli maltose-binding protein (R), and (iii) a purified inactivated virus vaccine (P). Groups of four rhesus macaques each were primed once and boosted twice using seven different vaccination regimens. After primary vaccination, enzyme-linked immunosorbent assay (ELISA) antibody levels increased most rapidly for groups inoculated with the P and DP combination, and by 1 month after the second boost, ELISA titers were similar for all groups. The highest plaque reduction neutralization test (PRNT) titers were seen in those groups that received the DR/DR/DR combination (geometric mean titer [GMT], 510), the P/P/P vaccine (GMT, 345), the DP/DP/DP combination (GMT, 287), and the R/R/R vaccine (GMT, 200). The next highest titers were seen in animals that received the D/R/R vaccine (GMT, 186) and the D/P/P vaccine (GMT, 163). Animals that received the D/D/D vaccine had the lowest neutralizing antibody titer (GMT, 49). Both ELISA and PRNT titers declined at variable rates. The only significant protection from viremia was observed in the P-vaccinated animals (mean of 0.5 days), which also showed the highest antibody concentration, including antibodies to NS1, and highest antibody avidity at the time of challenge.

Biotechnology approaches to produce potent, self-adjuvanting antigen-adjuvant fusion protein subunit vaccines.

PubMed

Moyle, Peter Michael

Traditional vaccination approaches (e.g. live attenuated or killed microorganisms) are among the most effective means to prevent the spread of infectious diseases. These approaches, nevertheless, have failed to yield successful vaccines against many important pathogens. To overcome this problem, methods have been developed to identify microbial components, against which protective immune responses can be elicited. Subunit antigens identified by these approaches enable the production of defined vaccines, with improved safety profiles. However, they are generally poorly immunogenic, necessitating their administration with potent immunostimulatory adjuvants. Since few safe and effective adjuvants are currently used in vaccines approved for human use, with those available displaying poor potency, or an inability to stimulate the types of immune responses required for vaccines against specific diseases (e.g. cytotoxic lymphocytes (CTLs) to treat cancers), the development of new vaccines will be aided by the availability of characterized platforms of new adjuvants, improving our capacity to rationally select adjuvants for different applications. One such approach, involves the addition of microbial components (pathogen-associated molecular patterns; PAMPs), that can stimulate strong immune responses, into subunit vaccine formulations. The conjugation of PAMPs to subunit antigens provides a means to greatly increase vaccine potency, by targeting immunostimulation and antigen to the same antigen presenting cell. Thus, methods that enable the efficient, and inexpensive production of antigen-adjuvant fusions represent an exciting mean to improve immunity towards subunit antigens. Herein we review four protein-based adjuvants (flagellin, bacterial lipoproteins, the extra domain A of fibronectin (EDA), and heat shock proteins (Hsps)), which can be genetically fused to antigens to enable recombinant production of antigen-adjuvant fusion proteins, with a focus on their

Influenza vaccines: from whole virus preparations to recombinant protein technology.

PubMed

Huber, Victor C

2014-01-01

Vaccination against influenza represents our most effective form of prevention. Historical approaches toward vaccine creation and production have yielded highly effective vaccines that are safe and immunogenic. Despite their effectiveness, these historical approaches do not allow for the incorporation of changes into the vaccine in a timely manner. In 2013, a recombinant protein-based vaccine that induces immunity toward the influenza virus hemagglutinin was approved for use in the USA. This vaccine represents the first approved vaccine formulation that does not require an influenza virus intermediate for production. This review presents a brief history of influenza vaccines, with insight into the potential future application of vaccines generated using recombinant technology.

Recombinant protein subunit vaccine synthesis in microbes: a role for yeast?

PubMed

Bill, Roslyn M

2015-03-01

Recombinant protein subunit vaccines are formulated using protein antigens that have been synthesized in heterologous host cells. Several host cells are available for this purpose, ranging from Escherichia coli to mammalian cell lines. This article highlights the benefits of using yeast as the recombinant host. The yeast species, Saccharomyces cerevisiae and Pichia pastoris, have been used to optimize the functional yields of potential antigens for the development of subunit vaccines against a wide range of diseases caused by bacteria and viruses. Saccharomyces cerevisiae has also been used in the manufacture of 11 approved vaccines against hepatitis B virus and one against human papillomavirus; in both cases, the recombinant protein forms highly immunogenic virus-like particles. Advances in our understanding of how a yeast cell responds to the metabolic load of producing recombinant proteins will allow us to identify host strains that have improved yield properties and enable the synthesis of more challenging antigens that cannot be produced in other systems. Yeasts therefore have the potential to become important host organisms for the production of recombinant antigens that can be used in the manufacture of subunit vaccines or in new vaccine development. © 2014 Royal Pharmaceutical Society.

Toward selective elicitation of TH1-controlled vaccination responses: vaccine applications of bacterial surface layer proteins.

PubMed

Jahn-Schmid, B; Messner, P; Unger, F M; Sleytr, U B; Scheiner, O; Kraft, D

1996-01-26

Bacterial surface layer proteins have been utilized as combined vaccine carrier/adjuvants and offer a number of advantages in these applications. The crystalline protein arrays contain functional groups in precisely defined orientations for coupling of haptens. Conventional applications of S-layer vaccines do not cause observable trauma or side effects. Depending on the nature of the S-layer preparations, antigenic conjugates will induce immune responses of a predominantly cellular or predominantly humoral nature. Immune responses to S-layer-hapten conjugates are also observed following oral/nasal application. In the present contribution, the status of investigations with S-layer conjugates in three main immunological projects is reviewed. In a project aimed at immunotherapy of cancer, conjugates of S-layer with small, tumor-associated oligosaccharides have been found to elicit hapten-specific DTH responses. An enlarged program of chemical synthesis has now been initiated to prepare a complete set of mucin-derived, tumor-associated oligosaccharides and their chemically modified analogues for elicitation of cell-mediated immune responses to certain tumors in humans. In another application, oligosaccharides derived from capsules of Streptococcus pneumoniae type 8 have been linked to S-layer proteins and have been found to elicit protective antibody responses in animals. Most recently, allergen S-layer conjugates have been prepared with the intention to suppress the TH2-directed, IgE-mediated allergic responses to Bet nu 1, the major allergen of birch pollen. In the former two applications, the S-layer vaccine technology appears to offer the versatility needed to direct vaccination responses toward predominant control by TH1 or TH2 lymphocytes to meet the different therapeutic or prophylactic requirements in each case. In the third application, work has progressed to a preliminary stage only.

Combat pneumococcal infections: adhesins as candidates for protein-based vaccine development.

PubMed

Gamez, Gustavo; Hammerschmidt, Sven

2012-03-01

Streptococcus pneumoniae (pneumococcus) is an asymptomatic colonizer of the upper respiratory tract in humans. However, these apparently harmless bacteria have also a high virulence potential and are known as the etiologic agent of respiratory and life-threatening invasive diseases. Dissemination of pneumococci from the nasopharynx into the lungs or bloodstream leads to community-acquired pneumonia, septicaemia and meningitis. Traditionally, pneumococcal diseases are treated with antibiotics and prevented with polysaccharide-based vaccines. However, due to the dramatic increase in antibiotic resistance and limitations of the current available vaccines, the burden of diseases remains high. Thus, combating pneumococcal transmission and infections has emphasized the need for a new generation of protein-based vaccines. Interactions of pneumococci with soluble host proteins or cellular receptors are crucial for adherence, colonization, transmigration of host barriers and immune evasion. Therefore, surface-exposed proteins involved in these pathogenic processes and virtually expressed by all pneumococcal strains and serotypes are the prime potential targets for an immunogenic and highly protective pneumococcal-derived carrier protein of a vaccine. In this review, we will address the state of the art in deciphering, i). the conservation, distribution and pathogenic role of recently discovered pneumococcal adhesins in colonization and invasive diseases, ii). the interactions of these virulence factors with host-proteins and receptors, iii). the subversion of the host immune and cellular responses, and iv). the potential of pneumococcal adhesins as vaccine candidates.

Matrix-M™ adjuvant enhances immunogenicity of both protein- and modified vaccinia virus Ankara-based influenza vaccines in mice.

PubMed

Magnusson, Sofia E; Altenburg, Arwen F; Bengtsson, Karin Lövgren; Bosman, Fons; de Vries, Rory D; Rimmelzwaan, Guus F; Stertman, Linda

2018-04-01

Influenza viruses continuously circulate in the human population and escape recognition by virus neutralizing antibodies induced by prior infection or vaccination through accumulation of mutations in the surface proteins hemagglutinin (HA) and neuraminidase (NA). Various strategies to develop a vaccine that provides broad protection against different influenza A viruses are under investigation, including use of recombinant (r) viral vectors and adjuvants. The replication-deficient modified vaccinia virus Ankara (MVA) is a promising vaccine vector that efficiently induces B and T cell responses specific for the antigen of interest. It is assumed that live vaccine vectors do not require an adjuvant to be immunogenic as the vector already mediates recruitment and activation of immune cells. To address this topic, BALB/c mice were vaccinated with either protein- or rMVA-based HA influenza vaccines, formulated with or without the saponin-based Matrix-M™ adjuvant. Co-formulation with Matrix-M significantly increased HA vaccine immunogenicity, resulting in antigen-specific humoral and cellular immune responses comparable to those induced by unadjuvanted rMVA-HA. Of special interest, rMVA-HA immunogenicity was also enhanced by addition of Matrix-M, demonstrated by enhanced HA inhibition antibody titres and cellular immune responses. Matrix-M added to either protein- or rMVA-based HA vaccines mediated recruitment and activation of antigen-presenting cells and lymphocytes to the draining lymph node 24 and 48 h post-vaccination. Taken together, these results suggest that adjuvants can be used not only with protein-based vaccines but also in combination with rMVA to increase vaccine immunogenicity, which may be a step forward to generate new and more effective influenza vaccines.

Fusion Protein Vaccines Targeting Two Tumor Antigens Generate Synergistic Anti-Tumor Effects

PubMed Central

Cheng, Wen-Fang; Chang, Ming-Cheng; Sun, Wei-Zen; Jen, Yu-Wei; Liao, Chao-Wei; Chen, Yun-Yuan; Chen, Chi-An

2013-01-01

Introduction Human papillomavirus (HPV) has been consistently implicated in causing several kinds of malignancies, and two HPV oncogenes, E6 and E7, represent two potential target antigens for cancer vaccines. We developed two fusion protein vaccines, PE(ΔIII)/E6 and PE(ΔIII)/E7 by targeting these two tumor antigens to test whether a combination of two fusion proteins can generate more potent anti-tumor effects than a single fusion protein. Materials and Methods In vivo antitumor effects including preventive, therapeutic, and antibody depletion experiments were performed. In vitro assays including intracellular cytokine staining and ELISA for Ab responses were also performed. Results PE(ΔIII)/E6+PE(ΔIII)/E7 generated both stronger E6 and E7-specific immunity. Only 60% of the tumor protective effect was observed in the PE(ΔIII)/E6 group compared to 100% in the PE(ΔIII)/E7 and PE(ΔIII)/E6+PE(ΔIII)/E7 groups. Mice vaccinated with the PE(ΔIII)/E6+PE(ΔIII)/E7 fusion proteins had a smaller subcutaneous tumor size than those vaccinated with PE(ΔIII)/E6 or PE(ΔIII)/E7 fusion proteins alone. Conclusion Fusion protein vaccines targeting both E6 and E7 tumor antigens generated more potent immunotherapeutic effects than E6 or E7 tumor antigens alone. This novel strategy of targeting two tumor antigens together can promote the development of cancer vaccines and immunotherapy in HPV-related malignancies. PMID:24058440

Vaccine potential of recombinant saposin-like protein 2 against Fasciolosis gigantica in mice.

PubMed

Kueakhai, Pornanan; Changklungmoa, Narin; Riengrojpitak, Suda; Chaichanasak, Pannigan; Meemon, Krai; Chaithirayanon, Kulathida; Chantree, Pathanin; Sansri, Veerawat; Itagaki, Tadashi; Sobhon, Prasert

2013-11-12

Saposin-like protein 2 (SAP-2) is a protein that adult of Fasciola spp. use to lyse plasma membrane of red blood cells, so that their contents can be digested by proteases for the parasites' nutrients. Thus SAP-2 is a plausible target for vaccination against these parasites. Recombinant Fasciola gigantica saposin-like protein 2 (rFgSAP-2) was expressed in Escherichia coli BL21 (DE3). A vaccination was performed in ICR mice (n=10) by subcutaneous injection with 50μg of rFgSAP-2 combined with Freund's adjuvant. At 2 weeks after the second boost, mice were infected with 30 F. gigantica metacercariae by oral route. The percentages of protection of rFgSAP-2 vaccine against F. gigantica were estimated to be 76.4-78.5% when compared with non vaccinated-infected and adjuvant-infected controls, respectively. The antibodies in immune sera of vaccinated mice were shown by immuno-blotting to react with native FgSAP-2 in the extract of 2- and 4-week-old juvenile parasites. By determining the levels of IgG1 and IgG2a in the immune sera, which are indicative of Th2 and Th1 immune responses, it was found that both Th1 and Th2 humoral immune response were significantly increased in rFgSAP-2 immunized group compared with the control groups, with higher levels of Th2 (IgG1) than Th1 (IgG2a). The levels of serum aspartate aminotransferase (AST) and alanine transaminase (ALT) in rFgSAP-2-immunized group showed no significant difference from those of the non-immunized and infected group, indicating that early juvenile parasites induced liver parenchyma damage, even though the numbers of worm recoveries were significantly different. This study indicates that rFgSAP-2 has a high potential as a vaccine candidate against F. gigantica in mice, and this potential will be tested in larger economic animals. Copyright © 2013 Elsevier Ltd. All rights reserved.

Induction of HIV Neutralizing Antibodies against the MPER of the HIV Envelope Protein by HA/gp41 Chimeric Protein-Based DNA and VLP Vaccines

PubMed Central

Ye, Ling; Wen, Zhiyuan; Dong, Ke; Wang, Xi; Bu, Zhigao; Zhang, Huizhong; Compans, Richard W.; Yang, Chinglai

2011-01-01

Several conserved neutralizing epitopes have been identified in the HIV Env protein and among these, the MPER of gp41 has received great attention and is widely recognized as a promising target. However, little success has been achieved in eliciting MPER-specific HIV neutralizing antibodies by a number of different vaccine strategies. We investigated the ability of HA/gp41 chimeric protein-based vaccines, which were designed to enhance the exposure of the MPER in its native conformation, to induce MPER-specific HIV neutralizing antibodies. In characterization of the HA/gp41 chimeric protein, we found that by mutating an unpaired Cys residue (Cys-14) in its HA1 subunit to a Ser residue, the modified chimeric protein HA-C14S/gp41 showed increased reactivity to a conformation-sensitive monoclonal antibody against HA and formed more stable trimers in VLPs. On the other hand, HA-C14S/gp41 and HA/gp41 chimeric proteins expressed on the cell surfaces exhibited similar reactivity to monoclonal antibodies 2F5 and 4E10. Immunization of guinea pigs using the HA-C14S/gp41 DNA or VLP vaccines induced antibodies against the HIV gp41 as well as to a peptide corresponding to a segment of MPER at higher levels than immunization by standard HIV VLPs. Further, sera from vaccinated guinea pigs were found to exhibit HIV neutralizing activities. Moreover, sera from guinea pigs vaccinated by HA-C14S/gp41 DNA and VLP vaccines but not the standard HIV VLPs, were found to neutralize HIV pseudovirions containing a SIV-4E10 chimeric Env protein. The virus neutralization could be blocked by a MPER-specific peptide, thus demonstrating induction of MPER-specific HIV neutralizing antibodies by this novel vaccine strategy. These results show that induction of MPER-specific HIV neutralizing antibodies can be achieved through a rationally designed vaccine strategy. PMID:21625584

Evaluation of immune responses and analysis of the effect of vaccination of the Leishmania major recombinant ribosomal proteins L3 or L5 in two different murine models of cutaneous leishmaniasis.

PubMed

Ramírez, Laura; Santos, Diego M; Souza, Ana P; Coelho, Eduardo A F; Barral, Aldina; Alonso, Carlos; Escutia, Marta R; Bonay, Pedro; de Oliveira, Camila I; Soto, Manuel

2013-02-18

Four new antigenic proteins located in Leishmania ribosomes have been characterized: S4, S6, L3 and L5. Recombinant versions of the four ribosomal proteins from Leishmania major were recognized by sera from human and canine patients suffering different clinical forms of leishmaniasis. The prophylactic properties of these proteins were first studied in the experimental model of cutaneous leishmaniasis caused by L. major inoculation into BALB/c mice. The administration of two of them, LmL3 or LmL5 combined with CpG-oligodeoxynucleotides (CpG-ODN) was able to protect BALB/c mice against L. major infection. Vaccinated mice showed smaller lesions and parasite burden compared to mice inoculated with vaccine diluent or vaccine adjuvant. Protection was correlated with an antigen-specific increased production of IFN-γ paralleled by a decrease of the antigen-specific IL-10 mediated response in protected mice relative to non-protected controls. Further, it was demonstrated that BALB/c mice vaccinated with recombinant LmL3 or LmL5 plus CpG-ODN were also protected against the development of cutaneous lesions following inoculation of L. braziliensis. Together, data presented here indicate that LmL3 or LmL5 ribosomal proteins combined with Th1 inducing adjuvants, may be relevant components of a vaccine against cutaneous leishmaniasis caused by distinct species. Copyright © 2013 Elsevier Ltd. All rights reserved.

Different applications of virus-like particles in biology and medicine: Vaccination and delivery systems.

PubMed

Shirbaghaee, Zeinab; Bolhassani, Azam

2016-03-01

Virus-like particles (VLPs) mimic the whole construct of virus particles devoid of viral genome as used in subunit vaccine design. VLPs can elicit efficient protective immunity as direct immunogens compared to soluble antigens co-administered with adjuvants in several booster injections. Up to now, several prokaryotic and eukaryotic systems such as insect, yeast, plant, and E. coli were used to express recombinant proteins, especially for VLP production. Recent studies are also generating VLPs in plants using different transient expression vectors for edible vaccines. VLPs and viral particles have been applied for different functions such as gene therapy, vaccination, nanotechnology, and diagnostics. Herein, we describe VLP production in different systems as well as its applications in biology and medicine. © 2015 Wiley Periodicals, Inc.

Jenner-predict server: prediction of protein vaccine candidates (PVCs) in bacteria based on host-pathogen interactions

PubMed Central

2013-01-01

Background Subunit vaccines based on recombinant proteins have been effective in preventing infectious diseases and are expected to meet the demands of future vaccine development. Computational approach, especially reverse vaccinology (RV) method has enormous potential for identification of protein vaccine candidates (PVCs) from a proteome. The existing protective antigen prediction software and web servers have low prediction accuracy leading to limited applications for vaccine development. Besides machine learning techniques, those software and web servers have considered only protein’s adhesin-likeliness as criterion for identification of PVCs. Several non-adhesin functional classes of proteins involved in host-pathogen interactions and pathogenesis are known to provide protection against bacterial infections. Therefore, knowledge of bacterial pathogenesis has potential to identify PVCs. Results A web server, Jenner-Predict, has been developed for prediction of PVCs from proteomes of bacterial pathogens. The web server targets host-pathogen interactions and pathogenesis by considering known functional domains from protein classes such as adhesin, virulence, invasin, porin, flagellin, colonization, toxin, choline-binding, penicillin-binding, transferring-binding, fibronectin-binding and solute-binding. It predicts non-cytosolic proteins containing above domains as PVCs. It also provides vaccine potential of PVCs in terms of their possible immunogenicity by comparing with experimentally known IEDB epitopes, absence of autoimmunity and conservation in different strains. Predicted PVCs are prioritized so that only few prospective PVCs could be validated experimentally. The performance of web server was evaluated against known protective antigens from diverse classes of bacteria reported in Protegen database and datasets used for VaxiJen server development. The web server efficiently predicted known vaccine candidates reported from Streptococcus pneumoniae and

G-protein based ELISA as a potency test for rabies vaccines.

PubMed

Chabaud-Riou, Martine; Moreno, Nadège; Guinchard, Fabien; Nicolai, Marie Claire; Niogret-Siohan, Elisabeth; Sève, Nicolas; Manin, Catherine; Guinet-Morlot, Françoise; Riou, Patrice

2017-03-01

The NIH test is currently used to assess the potency of rabies vaccine, a key criterion for vaccine release. This test is based on mice immunization followed by intracerebral viral challenge. As part of global efforts to reduce animal experimentation and in the framework of the development of Sanofi Pasteur next generation, highly-purified vaccine, produced without any material of human or animal origin, we developed an ELISA as an alternative to the NIH test. This ELISA is based on monoclonal antibodies recognizing specifically the native form of the viral G-protein, the major antigen that induces neutralizing antibody response to rabies virus. We show here that our ELISA is able to distinguish between potent and different types of sub-potent vaccine lots. Satisfactory agreement was observed between the ELISA and the NIH test in the determination of the vaccine titer and their capacity to discern conform from non-conform batches. Our ELISA meets the criteria for a stability-indicating assay and has been successfully used to develop the new generation of rabies vaccine candidates. After an EPAA international pre-collaborative study, this ELISA was selected as the assay of choice for the EDQM collaborative study aimed at replacing the rabies vaccine NIH in vivo potency test. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Influence of protein fold stability on immunogenicity and its implications for vaccine design

PubMed Central

Scheiblhofer, Sandra; Laimer, Josef; Machado, Yoan; Weiss, Richard; Thalhamer, Josef

2017-01-01

ABSTRACT Introduction: In modern vaccinology and immunotherapy, recombinant proteins more and more replace whole organisms to induce protective or curative immune responses. Structural stability of proteins is of crucial importance for efficient presentation of antigenic peptides on MHC, which plays a decisive role for triggering strong immune reactions. Areas covered: In this review, we discuss structural stability as a key factor for modulating the potency of recombinant vaccines and its importance for antigen proteolysis, presentation, and stimulation of B and T cells. Moreover, the impact of fold stability on downstream events determining the differentiation of T cells into effector cells is reviewed. We summarize studies investigating the impact of protein fold stability on the outcome of the immune response and provide an overview on computational methods to estimate the effects of point mutations on protein stability. Expert commentary: Based on this information, the rational design of up-to-date vaccines is discussed. A model for predicting immunogenicity of proteins based on their conformational stability at different pH values is proposed. PMID:28290225

Structure-based design of broadly protective group a streptococcal M protein-based vaccines.

PubMed

Dale, James B; Smeesters, Pierre R; Courtney, Harry S; Penfound, Thomas A; Hohn, Claudia M; Smith, Jeremy C; Baudry, Jerome Y

2017-01-03

A major obstacle to the development of broadly protective M protein-based group A streptococcal (GAS) vaccines is the variability within the N-terminal epitopes that evoke potent bactericidal antibodies. The concept of M type-specific protective immune responses has recently been challenged based on the observation that multivalent M protein vaccines elicited cross-reactive bactericidal antibodies against a number of non-vaccine M types of GAS. Additionally, a new "cluster-based" typing system of 175M proteins identified a limited number of clusters containing closely related M proteins. In the current study, we used the emm cluster typing system, in combination with computational structure-based peptide modeling, as a novel approach to the design of potentially broadly protective M protein-based vaccines. M protein sequences (AA 16-50) from the E4 cluster containing 17 emm types of GAS were analyzed using de novo 3-D structure prediction tools and the resulting structures subjected to chemical diversity analysis to identify sequences that were the most representative of the 3-D physicochemical properties of the M peptides in the cluster. Five peptides that spanned the range of physicochemical attributes of all 17 peptides were used to formulate synthetic and recombinant vaccines. Rabbit antisera were assayed for antibodies that cross-reacted with E4 peptides and whole bacteria by ELISA and for bactericidal activity against all E4GAS. The synthetic vaccine rabbit antisera reacted with all 17 E4M peptides and demonstrated bactericidal activity against 15/17 E4GAS. A recombinant hybrid vaccine containing the same E4 peptides also elicited antibodies that cross-reacted with all E4M peptides. Comprehensive studies using structure-based design may result in a broadly protective M peptide vaccine that will elicit cluster-specific and emm type-specific antibody responses against the majority of clinically relevant emm types of GAS. Copyright © 2016 Elsevier Ltd. All

A Plasmodium Promiscuous T Cell Epitope Delivered within the Ad5 Hexon Protein Enhances the Protective Efficacy of a Protein Based Malaria Vaccine.

PubMed

Fonseca, Jairo Andres; Cabrera-Mora, Monica; Kashentseva, Elena A; Villegas, John Paul; Fernandez, Alejandra; Van Pelt, Amelia; Dmitriev, Igor P; Curiel, David T; Moreno, Alberto

2016-01-01

A malaria vaccine is a public health priority. In order to produce an effective vaccine, a multistage approach targeting both the blood and the liver stage infection is desirable. The vaccine candidates also need to induce balanced immune responses including antibodies, CD4+ and CD8+ T cells. Protein-based subunit vaccines like RTS,S are able to induce strong antibody response but poor cellular reactivity. Adenoviral vectors have been effective inducing protective CD8+ T cell responses in several models including malaria; nonetheless this vaccine platform exhibits a limited induction of humoral immune responses. Two approaches have been used to improve the humoral immunogenicity of recombinant adenovirus vectors, the use of heterologous prime-boost regimens with recombinant proteins or the genetic modification of the hypervariable regions (HVR) of the capsid protein hexon to express B cell epitopes of interest. In this study, we describe the development of capsid modified Ad5 vectors that express a promiscuous Plasmodium yoelii T helper epitope denominated PyT53 within the hexon HVR2 region. Several regimens were tested in mice to determine the relevance of the hexon modification in enhancing protective immune responses induced by the previously described protein-based multi-stage experimental vaccine PyCMP. A heterologous prime-boost immunization regime that combines a hexon modified vector with transgenic expression of PyCMP followed by protein immunizations resulted in the induction of robust antibody and cellular immune responses in comparison to a similar regimen that includes a vector with unmodified hexon. These differences in immunogenicity translated into a better protective efficacy against both the hepatic and red blood cell stages of P. yoelii. To our knowledge, this is the first time that a hexon modification is used to deliver a promiscuous T cell epitope. Our data support the use of such modification to enhance the immunogenicity and protective

Oral vaccination of wildlife against rabies: Differences among host species in vaccine uptake efficiency.

PubMed

Vos, Ad; Freuling, Conrad M; Hundt, Boris; Kaiser, Christiane; Nemitz, Sabine; Neubert, Andreas; Nolden, Tobias; Teifke, Jens P; Te Kamp, Verena; Ulrich, Reiner; Finke, Stefan; Müller, Thomas

2017-07-13

Oral vaccination using attenuated and recombinant rabies vaccines has been proven a powerful tool to combat rabies in wildlife. However, clear differences have been observed in vaccine titers needed to induce a protective immune response against rabies after oral vaccination in different reservoir species. The mechanisms contributing to the observed resistance against oral rabies vaccination in some species are not completely understood. Hence, the immunogenicity of the vaccine virus strain, SPBN GASGAS, was investigated in a species considered to be susceptible to oral rabies vaccination (red fox) and a species refractory to this route of administration (striped skunk). Additionally, the dissemination of the vaccine virus in the oral cavity was analyzed for these two species. It was shown that the palatine tonsils play a critical role in vaccine virus uptake. Main differences could be observed in palatine tonsil infection between both species, revealing a locally restricted dissemination of infected cells in foxes. The absence of virus infected cells in palatine tonsils of skunks suggests a less efficient uptake of or infection by vaccine virus which may lead to a reduced response to oral vaccination. Understanding the mechanisms of oral resistance to rabies virus vaccine absorption and primary replication may lead to the development of novel strategies to enhance vaccine efficacy in problematic species like the striped skunk. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Antibody responses to prime-boost vaccination with an HIV-1 gp145 envelope protein and chimpanzee adenovirus vectors expressing HIV-1 gp140.

PubMed

Emmer, Kristel L; Wieczorek, Lindsay; Tuyishime, Steven; Molnar, Sebastian; Polonis, Victoria R; Ertl, Hildegund C J

2016-10-23

Over 2 million individuals are infected with HIV type 1 (HIV-1) each year, yet an effective vaccine remains elusive. The most successful HIV-1 vaccine to date demonstrated 31% efficacy. Immune correlate analyses associated HIV-1 envelope (Env)-specific antibodies with protection, thus providing a path toward a more effective vaccine. We sought to test the antibody response from novel prime-boost vaccination with a chimpanzee-derived adenovirus (AdC) vector expressing a subtype C Env glycoprotein (gp)140 combined with either a serologically distinct AdC vector expressing gp140 of a different subtype C isolate or an alum-adjuvanted, partially trimeric gp145 from yet another subtype C isolate. Three different prime-boost regimens were tested in mice: AdC prime-protein boost, protein prime-AdC boost, and AdC prime-AdC boost. Each regimen was tested at two different doses of AdC vector in a total of six experimental groups. Sera were collected at various time points and evaluated by ELISA for Env-specific antibody binding, isotype, and avidity. Antibody functionality was assessed by pseudovirus neutralization assay. Priming with AdC followed by a protein boost or sequential immunizations with two AdC vectors induced HIV-1 Env-specific binding antibodies, including those to the variable region 2, whereas priming with protein followed by an AdC boost was relatively ineffective. Antibodies that cross-neutralized tier 1 HIV-1 from different subtypes were elicited with vaccine regimens that included immunizations with protein. Our study warrants further investigation of AdC vector and gp145 protein prime-boost vaccines and their ability to protect against acquisition in animal challenge studies.

Protection against bovine tuberculosis induced by oral vaccination of cattle with Mycobacterium bovis BCG is not enhanced by co-administration of mycobacterial protein vaccines.

PubMed

Wedlock, D Neil; Aldwell, Frank E; Vordermeier, H Martin; Hewinson, R Glyn; Buddle, Bryce M

2011-12-15

Mycobacterium bovis bacille Calmette-Guérin (BCG) delivered to calves by the oral route in a formulated lipid matrix has been previously shown to induce protection against bovine tuberculosis. A study was conducted in cattle to determine if a combination of a low dose of oral BCG and a protein vaccine could induce protective immunity to tuberculosis while not sensitising animals to tuberculin. Groups of calves (10 per group) were vaccinated by administering 2 × 10(7)colony forming units (CFU) of BCG orally or a combination of 2 × 10(7)CFU oral BCG and a protein vaccine comprised of M. bovis culture filtrate proteins (CFP) formulated with the adjuvants Chitin and Gel 01 and delivered by the intranasal route, or CFP formulated with Emulsigen and the TLR2 agonist Pam(3)CSK(4) and administered by the subcutaneous (s.c.) route. Two further groups were vaccinated with the CFP/Chitin/Gel 01 or CFP/Emulsigen/Pam(3)CSK(4) vaccines alone. Positive control groups were given 10(8)CFU oral BCG or 10(6)CFU s.c. BCG while a negative control group was non-vaccinated. All animals were challenged with M. bovis 15 weeks after vaccination and euthanized and necropsied at 16 weeks following challenge. Groups of cattle vaccinated with s.c. BCG, 10(8)CFU or 2 × 10(7)CFU oral BCG showed significant reductions in seven, three and four pathological or microbiological disease parameters, respectively, compared to the results for the non-vaccinated group. There was no evidence of protection in calves vaccinated with the combination of oral BCG and CFP/Emulsigen/Pam(3)CSK(4) or oral BCG and CFP/Chitin/Gel 01 or vaccinated with the protein vaccines alone. Positive responses in the comparative cervical skin test at 12 weeks after vaccination were only observed in animals vaccinated with s.c. BCG, 10(8)CFU oral BCG or a combination of 2 × 10(7)CFU oral BCG and CFP/Chitin/Gel 01. In conclusion, co-administration of a protein vaccine, administered by either systemic or mucosal routes with oral

Alga-Produced Cholera Toxin-Pfs25 Fusion Proteins as Oral Vaccines

PubMed Central

Gregory, James A.; Topol, Aaron B.; Doerner, David Z.

2013-01-01

Infectious diseases disproportionately affect indigent regions and are the greatest cause of childhood mortality in developing countries. Practical, low-cost vaccines for use in these countries are paramount to reducing disease burdens and concomitant poverty. Algae are a promising low-cost system for producing vaccines that can be orally delivered, thereby avoiding expensive purification and injectable delivery. We engineered the chloroplast of the eukaryotic alga Chlamydomonas reinhardtii to produce a chimeric protein consisting of the 25-kDa Plasmodium falciparum surface protein (Pfs25) fused to the β subunit of the cholera toxin (CtxB) to investigate an alga-based whole-cell oral vaccine. Pfs25 is a promising malaria transmission-blocking vaccine candidate that has been difficult to produce in traditional recombinant systems due to its structurally complex tandem repeats of epidermal growth factor-like domains. The noncatalytic CtxB domain of the cholera holotoxin assembles into a pentameric structure and acts as a mucosal adjuvant by binding GM1 ganglioside receptors on gut epithelial cells. We demonstrate that CtxB-Pfs25 accumulates as a soluble, properly folded and functional protein within algal chloroplasts, and it is stable in freeze-dried alga cells at ambient temperatures. In mice, oral vaccination using freeze-dried algae that produce CtxB-Pfs25 elicited CtxB-specific serum IgG antibodies and both CtxB- and Pfs25-specific secretory IgA antibodies. These data suggest that algae are a promising system for production and oral delivery of vaccine antigens, but as an orally delivered adjuvant, CtxB is best suited for eliciting secretory IgA antibodies for vaccine antigens against pathogens that invade mucosal surfaces using this strategy. PMID:23603678

Assessment of a recombinant F1-V fusion protein vaccine intended to protect Canada lynx (Lynx canadensis) from plague

USGS Publications Warehouse

Wolfe, Lisa L.; Shenk, Tanya M.; Powell, Bradford; Rocke, Tonie E.

2011-01-01

As part of an ongoing restoration program in Colorado, USA, we evaluated adverse reactions and seroconversion in captive Canada lynx (Lynx canadensis) after vaccination with a recombinant F1-V fusion protein vaccine against Yersinia pestis, the bacterium that causes plague. Ten adult female lynx received the F1-V vaccine; 10 source- and age-matched lynx remained unvaccinated as controls. All of the vaccinated and control lynx remained apparently healthy throughout the confinement period. We observed no evidence of injection site or systemic reactions to the F1-V vaccine. Among vaccinated lynx, differences in log10 reciprocal antibody titers measured in sera collected before and after vaccination (two doses) ranged from 1.2 to 5.2 for anti-F1 antibodies and from 0.6 to 5.2 for anti-V antibodies; titers in unvaccinated lynx did not change appreciably over the course of confinement prior to release, and thus differences in anti-F1 (P=0.003) and anti-V (P=0.0005) titers were greater among vaccinated lynx than among controls. Although our findings suggest that the F1-V fusion protein vaccine evaluated here is likely to stimulate antibody responses that may help protect Canada lynx from plague, we observed no apparent differences in survival between vaccinated and unvaccinated subject animals. Retrospectively, 22 of 50 (44%; 95% confidence interval 29–59%) unvaccinated lynx captured or recaptured in Colorado during 2000–08 had passive hemagglutination antibody titers >1:16, consistent with exposure to Y. pestis; paired pre- and postrelease titers available for eight of these animals showed titer increases similar in magnitude to those seen in response to vaccination, suggesting at least some lynx may naturally acquire immunity to plague in Colorado habitats.

Comparison of CRM197, diphtheria toxoid and tetanus toxoid as protein carriers for meningococcal glycoconjugate vaccines.

PubMed

Tontini, M; Berti, F; Romano, M R; Proietti, D; Zambonelli, C; Bottomley, M J; De Gregorio, E; Del Giudice, G; Rappuoli, R; Costantino, P; Brogioni, G; Balocchi, C; Biancucci, M; Malito, E

2013-10-01

Glycoconjugate vaccines are among the most effective and safest vaccines ever developed. Diphtheria toxoid (DT), tetanus toxoid (TT) and CRM197 have been mostly used as protein carriers in licensed vaccines. We evaluated the immunogenicity of serogroup A, C, W-135 and Y meningococcal oligosaccharides conjugated to CRM197, DT and TT in naïve mice. The three carriers were equally efficient in inducing an immune response against the carbohydrate moiety in immunologically naïve mice. The effect of previous exposure to different dosages of the carrier protein on the anti-carbohydrate response was studied using serogroup A meningococcal (MenA) saccharide conjugates as a model. CRM197 showed a strong propensity to positively prime the anti-carbohydrate response elicited by its conjugates or those with the antigenically related carrier DT. Conversely in any of the tested conditions TT priming did not result in enhancement of the anti-carbohydrate response elicited by the corresponding conjugates. Repeated exposure of mice to TT or to CRM197 before immunization with the respective MenA conjugates resulted in a drastic suppression of the anti-carbohydrate response in the case of TT conjugate and only in a slight reduction in the case of CRM197. The effect of carrier priming on the anti-MenA response of DT-based conjugates varied depending on their carbohydrate to protein ratio. These data may have implications for human vaccination since conjugate vaccines are widely used in individuals previously immunized with DT and TT carrier proteins. Copyright © 2013 Elsevier Ltd. All rights reserved.

Evaluation of cross-protection against three topotypes of serotype O foot-and-mouth disease virus in pigs vaccinated with multi-epitope protein vaccine incorporated with poly(I:C).

PubMed

Cao, Yimei; Lu, Zengjun; Li, Dong; Fan, Pengju; Sun, Pu; Bao, Huifang; Fu, Yuanfang; Li, Pinghua; Bai, Xingwen; Chen, Yingli; Xie, Baoxia; Liu, Zaixin

2014-01-31

Epitope-based vaccines are always questioned for their cross-protection against the antigenically variable foot-and-mouth disease virus (FMDV). In this study, we proved the cross-protection effect of a multi-epitope vaccine incorporated with poly(I:C) against three topotypes of O type FMDV. A total of 45 naïve pigs were vaccinated with different doses of multi-epitope protein vaccine incorporated with poly(I:C). At 28 days post-vaccination, 45 vaccinated and 6 unvaccinated control pigs (two pigs for each group) were challenged with three topotypes of virulent O type FMDV, namely, O/Mya/98 (Southeast Asia topotype), O/HN/CHA/93 (Cathay topotype) and O/Tibet/CHA/99 (PanAsia topotype) strains. All unvaccinated pigs developed generalised FMD clinical signs. Results showed that all pigs (n=15) conferred complete protection against the O/Mya/98 and O/HN/CHA/93 FMDV strains, 11 of which were protected against the O/Tibet/CHA/99 FMDV strain. The 50% protective dose values of the vaccine against the O/Mya/98, O/HN/CHA/93 and O/Tibet/CHA/99 FMDV strains were 15.59, 15.59 and 7.05, respectively. Contact challenge experiment showed that transmission occurred from the donors to the unvaccinated but not to vaccinated pigs. These results showed that vaccination with multi-epitope protein vaccine incorporated with poly(I:C) can efficiently prevent FMD in pigs. Copyright © 2013 Elsevier B.V. All rights reserved.

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.

Non-conventional expression systems for the production of vaccine proteins and immunotherapeutic molecules

PubMed Central

Legastelois, Isabelle; Buffin, Sophie; Peubez, Isabelle; Mignon, Charlotte; Sodoyer, Régis; Werle, Bettina

2017-01-01

ABSTRACT The increasing demand for recombinant vaccine antigens or immunotherapeutic molecules calls into question the universality of current protein expression systems. Vaccine production can require relatively low amounts of expressed materials, but represents an extremely diverse category consisting of different target antigens with marked structural differences. In contrast, monoclonal antibodies, by definition share key molecular characteristics and require a production system capable of very large outputs, which drives the quest for highly efficient and cost-effective systems. In discussing expression systems, the primary assumption is that a universal production platform for vaccines and immunotherapeutics will unlikely exist. This review provides an overview of the evolution of traditional expression systems, including mammalian cells, yeast and E.coli, but also alternative systems such as other bacteria than E. coli, transgenic animals, insect cells, plants and microalgae, Tetrahymena thermophila, Leishmania tarentolae, filamentous fungi, cell free systems, and the incorporation of non-natural amino acids. PMID:27905833

Protein Energy Malnutrition during Vaccination Has Limited Influence on Vaccine Efficacy but Abolishes Immunity if Administered during Mycobacterium tuberculosis Infection

PubMed Central

Hoang, Truc; Agger, Else Marie; Cassidy, Joseph P.; Christensen, Jan P.

2015-01-01

Protein energy malnutrition (PEM) increases susceptibility to infectious diseases, including tuberculosis (TB), but it is not clear how PEM influences vaccine-promoted immunity to TB. We demonstrate that PEM during low-level steady-state TB infection in a mouse model results in rapid relapse of Mycobacterium tuberculosis, as well as increased pathology, in both Mycobacterium bovis BCG-vaccinated and unvaccinated animals. PEM did not change the overall numbers of CD4 T cells in BCG-vaccinated animals but resulted in an almost complete loss of antigen-specific cytokine production. Furthermore, there was a change in cytokine expression characterized by a gradual loss of multifunctional antigen-specific CD4 T cells and an increased proportion of effector cells expressing gamma interferon and tumor necrosis factor alpha (IFN-γ+ TNF-α+ and IFN-γ+ cells). PEM during M. tuberculosis infection completely blocked the protection afforded by the H56-CAF01 subunit vaccine, and this was associated with a very substantial loss of the interleukin-2-positive memory CD4 T cells promoted by this vaccine. Similarly, PEM during the vaccination phase markedly reduced the H56-CAF01 vaccine response, influencing all cytokine-producing CD4 T cell subsets, with the exception of CD4 T cells positive for TNF-α only. Importantly, this impairment was reversible and resupplementation of protein during infection rescued both the vaccine-promoted T cell response and the protective effect of the vaccine against M. tuberculosis infection. PMID:25754202

Vaccines against Botulism.

PubMed

Sundeen, Grace; Barbieri, Joseph T

2017-09-02

Botulinum neurotoxins (BoNT) cause the flaccid paralysis of botulism by inhibiting the release of acetylcholine from motor neurons. There are seven serotypes of BoNT (A-G), with limited therapies, and no FDA approved vaccine for botulism. An investigational formalin-inactivated penta-serotype-BoNT/A-E toxoid vaccine was used to vaccinate people who are at high risk of contracting botulism. However, this formalin-inactivated penta-serotype-BoNT/A-E toxoid vaccine was losing potency and was discontinued. This article reviews the different vaccines being developed to replace the discontinued toxoid vaccine. These vaccines include DNA-based, viral vector-based, and recombinant protein-based vaccines. DNA-based vaccines include plasmids or viral vectors containing the gene encoding one of the BoNT heavy chain receptor binding domains (HC). Viral vectors reviewed are adenovirus, influenza virus, rabies virus, Semliki Forest virus, and Venezuelan Equine Encephalitis virus. Among the potential recombinant protein vaccines reviewed are HC, light chain-heavy chain translocation domain, and chemically or genetically inactivated holotoxin.

Vaccines against Botulism

PubMed Central

Sundeen, Grace; Barbieri, Joseph T.

2017-01-01

Botulinum neurotoxins (BoNT) cause the flaccid paralysis of botulism by inhibiting the release of acetylcholine from motor neurons. There are seven serotypes of BoNT (A-G), with limited therapies, and no FDA approved vaccine for botulism. An investigational formalin-inactivated penta-serotype-BoNT/A-E toxoid vaccine was used to vaccinate people who are at high risk of contracting botulism. However, this formalin-inactivated penta-serotype-BoNT/A-E toxoid vaccine was losing potency and was discontinued. This article reviews the different vaccines being developed to replace the discontinued toxoid vaccine. These vaccines include DNA-based, viral vector-based, and recombinant protein-based vaccines. DNA-based vaccines include plasmids or viral vectors containing the gene encoding one of the BoNT heavy chain receptor binding domains (HC). Viral vectors reviewed are adenovirus, influenza virus, rabies virus, Semliki Forest virus, and Venezuelan Equine Encephalitis virus. Among the potential recombinant protein vaccines reviewed are HC, light chain-heavy chain translocation domain, and chemically or genetically inactivated holotoxin. PMID:28869493

Safety, reactogenicity and immunogenicity of a novel pneumococcal protein-based vaccine in adults: a phase I/II randomized clinical study.

PubMed

Leroux-Roels, Geert; Maes, Cathy; De Boever, Fien; Traskine, Magali; Rüggeberg, Jens U; Borys, Dorota

2014-11-28

New vaccines containing highly conserved Streptococcus pneumoniae proteins such as pneumolysin toxoid (dPly) and histidine-triad protein D (PhtD) are being developed to provide broader protection against pneumococcal disease. This study evaluated the safety, reactogenicity and immunogenicity of different pneumococcal protein-containing formulations in adults. In a phase I double-blind study (www.clinicaltrials.gov: NCT00707798), healthy adults (18-40 years) were randomized (1:2:2:2:2:2:2) to receive two doses of one of six investigational vaccine formulations 2 months apart, or a single dose of the control 23-valent pneumococcal polysaccharide vaccine (23PPV; Pneumovax23™, Sanofi Pasteur MSD) followed by placebo. The investigational formulations contained dPly alone (10 or 30 μg), or both dPly and PhtD (10 or 30 μg each) alone or combined with the polysaccharide conjugates of the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV; Synflorix™, GlaxoSmithKline Vaccines). Two groups primed with a formulation containing dPly and PhtD (10 or 30 μg each) continued to the follow-up phase II study (NCT00896064), in which they received a booster dose at 5-9 months after primary vaccination. Of 156 enrolled and vaccinated adults, 146 completed the primary immunization and 43 adults received a booster dose. During primary and booster vaccination, for any formulation, ≤ 8.9% of doses were followed by grade 3 solicited local or general adverse events. No fever >39.5°C (oral temperature) was reported. Unsolicited adverse events considered causally related to vaccination were reported following ≤ 33.3% of investigational vaccine doses. No serious adverse events were reported for adults receiving investigational vaccine formulations. Formulations containing dPly with or without PhtD were immunogenic for these antigens; polysaccharide conjugate-containing formulations were also immunogenic for those 10 polysaccharides

Protective Immunity and Reduced Renal Colonization Induced by Vaccines Containing Recombinant Leptospira interrogans Outer Membrane Proteins and Flagellin Adjuvant

PubMed Central

Monaris, D.; Sbrogio-Almeida, M. E.; Dib, C. C.; Canhamero, T. A.; Souza, G. O.; Vasconcellos, S. A.; Ferreira, L. C. S.

2015-01-01

Leptospirosis is a global zoonotic disease caused by different Leptospira species, such as Leptospira interrogans, that colonize the renal tubules of wild and domestic animals. Thus far, attempts to develop effective leptospirosis vaccines, both for humans and animals, have failed to induce immune responses capable of conferring protection and simultaneously preventing renal colonization. In this study, we evaluated the protective immunity induced by subunit vaccines containing seven different recombinant Leptospira interrogans outer membrane proteins, including the carboxy-terminal portion of the immunoglobulinlike protein A (LigAC) and six novel antigens, combined with aluminum hydroxide (alum) or Salmonella flagellin (FliC) as adjuvants. Hamsters vaccinated with the different formulations elicited high antigen-specific antibody titers. Immunization with LigAC, either with alum or flagellin, conferred protective immunity but did not prevent renal colonization. Similarly, animals immunized with LigAC or LigAC coadministered with six leptospiral proteins with alum adjuvant conferred protection but did not reduce renal colonization. In contrast, immunizing animals with the pool of seven antigens in combination with flagellin conferred protection and significantly reduced renal colonization by the pathogen. The present study emphasizes the relevance of antigen composition and added adjuvant in the efficacy of antileptospirosis subunit vaccines and shows the complex relationship between immune responses and renal colonization by the pathogen. PMID:26108285

Could mycobacterial Hsp70-containing fusion protein lead the way to an affordable therapeutic cancer vaccine?

PubMed

Brauns, Timothy; Leblanc, Pierre; Gelfand, Jeffrey A; Poznanski, Mark

2015-03-01

Cancer vaccine development efforts have recently gained momentum, but most vaccines showing clinical impact in human trials tend to be based on technology approaches that are very costly and difficult to produce at scale. With the projected doubling of the incidence of cancer and its related cost of care in the U.S. over the next two decades, the widespread clinical use of such vaccines will prove difficult to justify. Heat shock protein-based vaccines have shown the potential to elicit clinically meaningful immunologic responses in cancer, but the predominant development approach - heat shock protein-peptide complexes derived from a patient's own tumor - face similar challenges of cost and scalability. New innovative modalities for deploying heat shock proteins in cancer vaccines may open the door to vaccines that can generate potent cytotoxic responses against multiple tumor targets and can be made in a cost-effective and scalable manner.

Eimeria maxima microneme protein 2 delivered as DNA vaccine and recombinant protein induces immunity against experimental homogenous challenge.

PubMed

Huang, Jingwei; Zhang, Zhenchao; Li, Menghui; Song, Xiaokai; Yan, Ruofeng; Xu, Lixin; Li, Xiangrui

2015-10-01

E. maxima is one of the seven species of Eimeria that infects chicken. Until now, only a few antigenic genes of E. maxima have been reported. In the present study, the immune protective effects against E. maxima challenge of recombinant protein and DNA vaccine encoding EmMIC2 were evaluated. Two-week-old chickens were randomly divided into five groups. The experimental group of chickens was immunized with 100 μg DNA vaccine pVAX1-MIC2 or 200 μg rEmMIC2 protein while the control group of chickens was injected with pVAX1 plasmid or sterile PBS. The results showed that the anti-EmMIC2 antibody titers of both rEmMIC2 protein and pVAX1-MIC2 groups were significantly higher as compared to PBS and pVAX1 control (P<0.05). The splenocytes from both vaccinated groups of chickens displayed significantly greater proliferation compared with the controls (P<0.05). Serum from chickens immunized with pVAX1-MIC2 and rEmMIC2 protein displayed significantly high levels of IL-2, IFN-γ, IL-10, IL-17, TGF-β and IL-4 (P<0.05) compared to those of negative controls. The challenge experiment results showed that both the recombinant protein and the DNA vaccine could obviously alleviate jejunum lesions, body weight loss, increase oocyst, decrease ratio and provide ACIs of more than 165. All the above results suggested that immunization with EmMIC2 was effective in imparting partial protection against E. maxima challenge and it could be an effective antigen candidate for the development of new vaccines against E. maxima. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Expression, purification and re folding of a self-assembling protein nanoparticle (SAPN) malaria vaccine

PubMed Central

Guo, Qin; Dasgupta, Debleena; Doll, Tais A.P.F.; Burkhard, Peter; Lanar, David E.

2013-01-01

There are many ways to present antigens to the immune system. We have used a repetitive antigen display technology that relies on the self-assembly of 60 protein chains into a spherical self-assembling protein nanoparticle (SAPN) to develop a vaccine against Plasmodium falciparum malaria. The protein sequence contains selected B- and T-cell epitopes of the circumsporozoite protein of P. falciparum (PfCSP) and, when assembled into a nanoparticle induces strong, long-lived and protective immune responses against the PfCSP. Here we describe the conditions needed for promoting self-assembly of a P. falciparum vaccine nanoparticle, PfCSP-KMY-SAPN, and note pitfalls that may occur when determining conditions for other SAPN vaccines. Attention was paid to selecting processes that were amenable to scale up and cGMP manufacturing. PMID:23548672

Protein Carriers for Glycoconjugate Vaccines: History, Selection Criteria, Characterization and New Trends.

PubMed

Micoli, Francesca; Adamo, Roberto; Costantino, Paolo

2018-06-15

Currently licensed glycoconjugate vaccines are composed of a carbohydrate moiety covalently linked to a protein carrier. Polysaccharides are T-cell independent antigens able to directly stimulate B cells to produce antibodies. Disease burden caused by polysaccharide-encapsulated bacteria is highest in the first year of life, where plain polysaccharides are not generally immunogenic, limiting their use as vaccines. This limitation has been overcome by covalent coupling carbohydrate antigens to proteins that provide T cell epitopes. In addition to the protein carriers currently used in licensed glycoconjugate vaccines, there is a search for new protein carriers driven by several considerations: (i) concerns that pre-exposure or co-exposure to a given carrier can lead to immune interference and reduction of the anti-carbohydrate immune response; (ii) increasing interest to explore the dual role of proteins as carrier and protective antigen; and (iii) new ways to present carbohydrates antigens to the immune system. Protein carriers can be directly coupled to activated glycans or derivatized to introduce functional groups for subsequent conjugation. Proteins can be genetically modified to pre-determine the site of glycans attachment by insertion of unnatural amino acids bearing specific functional groups, or glycosylation consensus sequences for in vivo expression of the glycoconjugate. A large portion of the new protein carriers under investigation are recombinant ones, but more complex systems such as Outer Membrane Vesicles and other nanoparticles are being investigated. Selection criteria for new protein carriers are based on several aspects including safety, manufacturability, stability, reactivity toward conjugation, and preclinical evidence of immunogenicity of corresponding glycoconjugates. Characterization panels of protein carriers include tests before conjugation, after derivatization when applicable, and after conjugation. Glycoconjugate vaccines based on

Vaccination of Mice Using the West Nile Virus E-Protein in a DNA Prime-Protein Boost Strategy Stimulates Cell-Mediated Immunity and Protects Mice against a Lethal Challenge

PubMed Central

De Filette, Marina; Soehle, Silke; Ulbert, Sebastian; Richner, Justin; Diamond, Michael S.; Sinigaglia, Alessandro; Barzon, Luisa; Roels, Stefan; Lisziewicz, Julianna; Lorincz, Orsolya; Sanders, Niek N.

2014-01-01

West Nile virus (WNV) is a mosquito-borne flavivirus that is endemic in Africa, the Middle East, Europe and the United States. There is currently no antiviral treatment or human vaccine available to treat or prevent WNV infection. DNA plasmid-based vaccines represent a new approach for controlling infectious diseases. In rodents, DNA vaccines have been shown to induce B cell and cytotoxic T cell responses and protect against a wide range of infections. In this study, we formulated a plasmid DNA vector expressing the ectodomain of the E-protein of WNV into nanoparticles by using linear polyethyleneimine (lPEI) covalently bound to mannose and examined the potential of this vaccine to protect against lethal WNV infection in mice. Mice were immunized twice (prime – boost regime) with the WNV DNA vaccine formulated with lPEI-mannose using different administration routes (intramuscular, intradermal and topical). In parallel a heterologous boost with purified recombinant WNV envelope (E) protein was evaluated. While no significant E-protein specific humoral response was generated after DNA immunization, protein boosting of DNA-primed mice resulted in a marked increase in total neutralizing antibody titer. In addition, E-specific IL-4 T-cell immune responses were detected by ELISPOT after protein boost and CD8+ specific IFN-γ expression was observed by flow cytometry. Challenge experiments using the heterologous immunization regime revealed protective immunity to homologous and virulent WNV infection. PMID:24503579

Worldwide genetic variability of the Duffy binding protein: insights into Plasmodium vivax vaccine development.

PubMed

Nóbrega de Sousa, Taís; Carvalho, Luzia Helena; Alves de Brito, Cristiana Ferreira

2011-01-01

The dependence of Plasmodium vivax on invasion mediated by Duffy binding protein (DBP) makes this protein a prime candidate for development of a vaccine. However, the development of a DBP-based vaccine might be hampered by the high variability of the protein ligand (DBP(II)), known to bias the immune response toward a specific DBP variant. Here, the hypothesis being investigated is that the analysis of the worldwide DBP(II) sequences will allow us to determine the minimum number of haplotypes (MNH) to be included in a DBP-based vaccine of broad coverage. For that, all DBP(II) sequences available were compiled and MNH was based on the most frequent nonsynonymous single nucleotide polymorphisms, the majority mapped on B and T cell epitopes. A preliminary analysis of DBP(II) genetic diversity from eight malaria-endemic countries estimated that a number between two to six DBP haplotypes (17 in total) would target at least 50% of parasite population circulating in each endemic region. Aiming to avoid region-specific haplotypes, we next analyzed the MNH that broadly cover worldwide parasite population. The results demonstrated that seven haplotypes would be required to cover around 60% of DBP(II) sequences available. Trying to validate these selected haplotypes per country, we found that five out of the eight countries will be covered by the MNH (67% of parasite populations, range 48-84%). In addition, to identify related subgroups of DBP(II) sequences we used a Bayesian clustering algorithm. The algorithm grouped all DBP(II) sequences in six populations that were independent of geographic origin, with ancestral populations present in different proportions in each country. In conclusion, in this first attempt to undertake a global analysis about DBP(II) variability, the results suggest that the development of DBP-based vaccine should consider multi-haplotype strategies; otherwise a putative P. vivax vaccine may not target some parasite populations.

[Antigen differences of genetic variants Abent+ and Abent- poliovirus vaccine strain of III type].

PubMed

Shyrobokov, V P; Kostenko, I H; Nikolaienko, I V

2003-01-01

Hybridomes--producers of monoclonal antibodies (MAB) were obtained able to differentiate the variants Abent+ and Abent- poliovirus vaccine strain in the virus neutralizing reaction. Using the obtained panel the changes of the epitope structure of capsid proteins of poliovirus variants (dissociants) were found which appeared during reproduction in cell culture. It proves the fact that there exist essential antigenic differences of superficial virion's proteins, which appear during the process of dissociation.

Conjugating recombinant proteins to Pseudomonas aeruginosa ExoProtein A: a strategy for enhancing immunogenicity of malaria vaccine candidates.

PubMed

Qian, Feng; Wu, Yimin; Muratova, Olga; Zhou, Hong; Dobrescu, Gelu; Duggan, Peter; Lynn, Lambert; Song, Guanhong; Zhang, Yanling; Reiter, Karine; MacDonald, Nicholas; Narum, David L; Long, Carole A; Miller, Louis H; Saul, Allan; Mullen, Gregory E D

2007-05-16

Conjugation of polysaccharides to carrier proteins has been a successful approach for producing safe and effective vaccines. In an attempt to increase the immunogenicity of two malarial vaccine candidate proteins of Plasmodium falciparum, apical membrane antigen 1 (AMA1) to a blood stage vaccine candidate and surface protein 25 (Pfs25) a mosquito stage vaccine candidate, were each independently chemically conjugated to the mutant, nontoxic Pseudomonas aeruginosa ExoProtein A (rEPA). AMA1 is a large (66kD) relatively good immunogen in mice; Pfs25 is a poorly immunogenic protein when presented on alum to mice. Mice were immunized on days 0 and 28 with AMA1- or Pfs25-rEPA conjugates or unconjugated AMA1 or Pfs25, all formulated on Alhydrogel. Remarkably, sera from mice 14 days after the second immunization with Pfs25-rEPA conjugates displayed over a 1000-fold higher antibody titers as compared to unconjugated Pfs25. In contrast, AMA1 conjugated under the same conditions induced only a three-fold increase in antibody titers. When tested for functional activity, antibodies elicited by the AMA1-rEPA inhibited invasion of erythrocytes by blood-stage parasites and antibodies elicited by the Pfs25-rEPA conjugates blocked the development of the sexual stage parasites in the mosquito midgut. These results demonstrate that conjugation to rEPA induces a marked improvement in the antibody titer in mice for the poor immunogen (Pfs25) and for the larger protein (AMA1). These conjugates now need to be tested in humans to determine if mice are predictive of the response in humans.

Glycolysis-related proteins are broad spectrum vaccine candidates against aquacultural pathogens.

PubMed

Liu, Xiaohong; Sun, Jiamin; Wu, Haizhen

2017-07-05

Reverse vaccinology (RV) has become a popular method for developing vaccines. Although Edwardsiella tarda is deemed to be an important fish pathogen, so far, no reports have used a genome-based approach to screen vaccine candidates against E. tarda. In the current study, protective antigens of E. tarda were screened using RV. Large-scale cloning, expression and purification of potential candidates were carried out, and their immunoprotective potential was evaluated. A candidate fructose-bisphosphate aldolase (FBA) exhibited broad spectrum protection, as did another glycolysis-related protein glyceraldehyde-3-phosphate dehydrogenase (GAPDH), which we reported previously, indicating the potential of other glycolysis-related proteins of E. tarda as broad spectrum protective antigens. In total, half (5 out 10) of these proteins showed prominent immunoprotective potential. Therefore, we suggest that glycolysis-related proteins are a class of potential broad spectrum protective antigens and that these proteins should be preferentially selected. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Effectiveness of Influenza Vaccination in Different Groups.

PubMed

Domínguez, Angela; Godoy, Pere; Torner, Nuria

2016-06-01

Annual administration of the seasonal influenza vaccine, especially to persons known to be at elevated risk for developing serious complications, is the focus of current efforts to reduce the impact of influenza. The main factors influencing estimated inactivated influenza vaccine efficacy and effectiveness, the results obtained in different population groups, current vaccination strategies and the possible advantages of new vaccines are discussed. The available evidence suggests that influenza vaccines are less effective in the elderly than in young adults, but vaccination is encouraged by public health institutions due to higher mortality and complications. There is no consensus on universal vaccination of children yet economic studies suggest that yearly paediatric vaccination is cost saving. The benefits of herd immunity generated by paediatric vaccination require further study. Newer vaccines should be more and more-broadly protective, stable, easy to manufacture and administer and highly immunogenic across all population groups.

Protein structure shapes immunodominance in the CD4 T cell response to yellow fever vaccination.

PubMed

Koblischke, Maximilian; Mackroth, Maria S; Schwaiger, Julia; Fae, Ingrid; Fischer, Gottfried; Stiasny, Karin; Heinz, Franz X; Aberle, Judith H

2017-08-21

The live attenuated yellow fever (YF) vaccine is a highly effective human vaccine and induces long-term protective neutralizing antibodies directed against the viral envelope protein E. The generation of such antibodies requires the help of CD4 T cells which recognize peptides derived from proteins in virus particles internalized and processed by E-specific B cells. The CD4 T helper cell response is restricted to few immunodominant epitopes, but the mechanisms of their selection are largely unknown. Here, we report that CD4 T cell responses elicited by the YF-17D vaccine are focused to hotspots of two helices of the viral capsid protein and to exposed strands and loops of E. We found that the locations of immunodominant epitopes within three-dimensional protein structures exhibit a high degree of overlap between YF virus and the structurally homologous flavivirus tick-borne encephalitis virus, although amino acid sequence identity of the epitope regions is only 15-45%. The restriction of epitopes to exposed E protein surfaces and their strikingly similar positioning within proteins of distantly related flaviviruses are consistent with a strong influence of protein structure that shapes CD4 T cell responses and provide leads for a rational design of immunogens for vaccination.

New vaccines against influenza virus

PubMed Central

Lee, Young-Tae; Kim, Ki-Hye; Ko, Eun-Ju; Lee, Yu-Na; Kim, Min-Chul; Kwon, Young-Man; Tang, Yinghua; Cho, Min-Kyoung; Lee, Youn-Jeong

2014-01-01

Vaccination is one of the most effective and cost-benefit interventions that prevent the mortality and reduce morbidity from infectious pathogens. However, the licensed influenza vaccine induces strain-specific immunity and must be updated annually based on predicted strains that will circulate in the upcoming season. Influenza virus still causes significant health problems worldwide due to the low vaccine efficacy from unexpected outbreaks of next epidemic strains or the emergence of pandemic viruses. Current influenza vaccines are based on immunity to the hemagglutinin antigen that is highly variable among different influenza viruses circulating in humans and animals. Several scientific advances have been endeavored to develop universal vaccines that will induce broad protection. Universal vaccines have been focused on regions of viral proteins that are highly conserved across different virus subtypes. The strategies of universal vaccines include the matrix 2 protein, the hemagglutinin HA2 stalk domain, and T cell-based multivalent antigens. Supplemented and/or adjuvanted vaccination in combination with universal target antigenic vaccines would have much promise. This review summarizes encouraging scientific advances in the field with a focus on novel vaccine designs. PMID:24427759

M Protein-Deficient Respiratory Syncytial Virus (RSV) Vaccine Protects Infant Baboons Against RSV Challenge

PubMed Central

Welliver, Robert C; Oomens, Antonius; Wolf, Roman; Papin, James; Ivanov, Vadim; Preno, Alisha; Staats, Rachel; Piedra, Pedro; Yu, Zhongxin

2017-01-01

Abstract Background RSV bronchiolitis is the most common cause of hospitalization of infants in the US, and may lead to the development of long-term airway disease. Inactivated vaccines may lead to enhanced disease, while replicating vaccines have caused unacceptable degrees of illness, and may revert back to wild type. We developed an RSV vaccine lacking the gene for the M protein (Mnull RSV). The M protein is responsible for reassembly of the virus after it infects cells and expresses its proteins. Infant baboons vaccinated intranasally (IN) with Mnull RSV develop serum neutralizing antibody (NA) responses, but the virus does not replicate. Methods 2-week-old baboons (n = 12) were primed IN with 107 vaccine units of Mnull RSV or a control preparation, and a similar booster dose was given 4 weeks later. Mnull RSV vaccination did not cause tachypnea, airway inflammation or other signs of illness when compared with sham-vaccinated controls. Two weeks after boosting, all infants were challenged intratracheally with human RSV A2. We continuously monitored respiratory rates and levels of overall activity. On various days following challenge, we obtained BAL fluids for leukocyte counts and degree of virus replication, and evaluated alveolar-arterial oxygen gradients (A-a O2). Results Vaccinated animals (vs. unvaccinated controls) had lower respiratory rates (P = 0.0014), improved A-a O2 (P = 0.0063) and reduced viral replication (P = 0.0014). Activity scores were higher in vaccine recipients than in unvaccinated animals. Vaccine recipients also were primed for earlier serum and secretory neutralizing antibody responses, and greater airway lymphocyte responses. Airway lymphocyte numbers (but not antibody responses) were associated with lower respiratory rates and reduced viral replication (P < 0.01). Conclusion Vaccination intranasally with Mnull RSV protected infant baboons against an RSV challenge without causing respiratory disease or enhanced illness, and

Insect cell-produced recombinant protein subunit vaccines protect against Zika virus infection.

PubMed

Qu, Panke; Zhang, Wei; Li, Dapeng; Zhang, Chao; Liu, Qingwei; Zhang, Xueyang; Wang, Xuesong; Dai, Wenlong; Xu, Yongfen; Leng, Qibin; Zhong, Jin; Jin, Xia; Huang, Zhong

2018-06-01

Infection with Zika virus (ZIKV) may lead to severe neurologic disorders. It is of significant importance and urgency to develop safe and effective vaccines to prevent ZIKV infection. Here we report the development of ZIKV subunit vaccines based on insect cell-produced recombinant proteins. The N-terminal approximately 80% region (designated as E80) and the domain III (designated as EDIII) of ZIKV envelope (E) protein were efficiently produced as secreted proteins in a Drosophila S2 cell expression system. Both E80 and EDIII could inhibit ZIKV infection in vitro, suggesting that they may have folded properly to display native conformations. Immunization studies demonstrated that both E80 and EDIII vaccines were able to trigger antigen-specific antibody and T-cell responses in mice. The resulting anti-E80 and anti-EDIII sera could potently neutralize ZIKV infection in vitro. More importantly, passive transfer of either anti-E80 or anti-EDIII sera protected recipient mice against lethal ZIKV challenge. It is worth noting that the anti-EDIII sera possessed higher neutralizing titers and conferred more complete protection than the anti-E80 sera, indicating that the S2 cell-produced EDIII is a superior ZIKV vaccine candidate compared with the E80. These data support further preclinical and clinical development of a ZIKV subunit vaccine based on S2 cell-produced EDIII. Copyright © 2018 Elsevier B.V. All rights reserved.

Immunogenicity of a Prime-Boost Vaccine Containing the Circumsporozoite Proteins of Plasmodium vivax in Rodents

PubMed Central

Teixeira, Lais H.; Tararam, Cibele A.; Lasaro, Marcio O.; Camacho, Ariane G. A.; Ersching, Jonatan; Leal, Monica T.; Herrera, Sócrates; Bruna-Romero, Oscar; Soares, Irene S.; Nussenzweig, Ruth S.; Ertl, Hildegund C. J.; Nussenzweig, Victor

2014-01-01

Plasmodium vivax is the most widespread and the second most prevalent malaria-causing species in the world. Current measures used to control the transmission of this disease would benefit from the development of an efficacious vaccine. In the case of the deadly parasite P. falciparum, the recombinant RTS,S vaccine containing the circumsporozoite antigen (CSP) consistently protects 30 to 50% of human volunteers against infection and is undergoing phase III clinical trials in Africa with similar efficacy. These findings encouraged us to develop a P. vivax vaccine containing the three circulating allelic forms of P. vivax CSP. Toward this goal, we generated three recombinant bacterial proteins representing the CSP alleles, as well as a hybrid polypeptide called PvCSP-All-CSP-epitopes. This hybrid contains the conserved N and C termini of P. vivax CSP and the three variant repeat domains in tandem. We also generated simian and human recombinant replication-defective adenovirus vectors expressing PvCSP-All-CSP-epitopes. Mice immunized with the mixture of recombinant proteins in a formulation containing the adjuvant poly(I·C) developed high and long-lasting serum IgG titers comparable to those elicited by proteins emulsified in complete Freund's adjuvant. Antibody titers were similar in mice immunized with homologous (protein-protein) and heterologous (adenovirus-protein) vaccine regimens. The antibodies recognized the three allelic forms of CSP, reacted to the repeated and nonrepeated regions of CSP, and recognized sporozoites expressing the alleles VK210 and VK247. The vaccine formulations described in this work should be useful for the further development of an anti-P. vivax vaccine. PMID:24478093

Cost-effectiveness of different human papillomavirus vaccines in Singapore.

PubMed

Lee, Vernon J; Tay, Sun Kuie; Teoh, Yee Leong; Tok, Mei Yin

2011-03-31

Human papillomavirus (HPV) vaccines are widely available and there have been studies exploring their potential clinical impact and cost-effectiveness. However, few studies have compared the cost-effectiveness among the 2 main vaccines available - a bivalent vaccine against HPV 16/18, and a quadrivalent vaccine against 6/11/16/18. We explore the cost-effectiveness of these two HPV vaccines in tropical Singapore. We developed a Markov state-transition model to represent the natural history of cervical cancer to predict HPV infection, cancer incidence, mortality, and costs. Cytologic screening and treatment of different outcomes of HPV infection were incorporated. Vaccination was provided to a cohort of 12-year old females in Singapore, followed up until death. Based on available vaccines on the market, the bivalent vaccine had increased effectiveness against a wider range of HPV types, while the quadrivalent vaccine had effectiveness against genital warts. Incremental cost-effectiveness ratios (ICER) compared vaccination to no-vaccination, and between the two vaccines. Sensitivity analyses explored differences in vaccine effectiveness and uptake, and other key input parameters. For the no vaccination scenario, 229 cervical cancer cases occurred over the cohort's lifetime. The total discounted cost per individual due to HPV infection was SGD$275 with 28.54 discounted life-years. With 100% vaccine coverage, the quadrivalent vaccine reduced cancers by 176, and had an ICER of SGD$12,866 per life-year saved. For the bivalent vaccine, 197 cancers were prevented with an ICER of $12,827 per life-year saved. Comparing the bivalent to the quadrivalent vaccine, the ICER was $12,488 per life-year saved. However, the cost per QALY saved for the quadrivalent vaccine compared to no vaccine was $9,071, while it was $10,392 for the bivalent vaccine, with the quadrivalent vaccine dominating the bivalent vaccine due to the additional QALY effect from reduction in genital warts. The

Ses proteins as possible targets for vaccine development against Staphylococcus epidermidis infections.

PubMed

Hofmans, Dorien; Khodaparast, Laleh; Khodaparast, Ladan; Vanstreels, Els; Shahrooei, Mohammad; Van Eldere, Johan; Van Mellaert, Lieve

2018-05-09

The opportunistic pathogen Staphylococcus epidermidis is progressively involved in device-related infections. Since these infections involve biofilm formation, antibiotics are not effective. Conversely, a vaccine can be advantageous to prevent these infections. In view of vaccine development, predicted surface proteins were evaluated on their potential as a vaccine target. Immunoglobulins directed against S. epidermidis surface proteins SesB, M, O, Q and R, were used to firstly affirm their surface location. Further, inhibitory effects of these IgGs on biofilm formation were determined in vitro on polystyrene and polyurethane surfaces and in vivo using a subcutaneous catheter mouse model. We also examined the opsonophagocytic capacity of these IgGs. Surface localization of the five Ses proteins was demonstrated both for planktonic and sessile cells, though to a variable extent. Ses-specific IgGs added to planktonic cells had a variable inhibitory effect on cell adhesion to polystyrene, while only anti-SesO IgGs decreased cell attachment to polyurethane catheters. Although phagocytic killing was only obtained after opsonisation with SesB-specific IgGs, a significant reduction of in vivo formed biofilms was observed after administration of SesB-, SesM- and SesO-specific IgGs. Regardless of their characterization or function, S. epidermidis surface proteins can be adequate targets for vaccine development aiming the prevention of device-related infections caused by invasive S. epidermidis strains. Copyright © 2018 Elsevier Ltd. All rights reserved.

Differences in HIV vaccine acceptability between genders

PubMed Central

Kakinami, Lisa; Newman, Peter A.; Lee, Sung-Jae; Duan, Naihua

2010-01-01

The development of safe and efficacious preventive HIV vaccines offers the best long-term hope of controlling the AIDS pandemic. Nevertheless, suboptimal uptake of safe and efficacious vaccines that already exist suggest that HIV vaccine acceptability cannot be assumed, particularly among communities most vulnerable to HIV. The present study aimed to identify barriers and motivators to future HIV vaccine acceptability among low socioeconomic, ethnically diverse men and women in Los Angeles County. Participants completed a cross-sectional survey assessing their attitudes and beliefs regarding future HIV vaccines. Hypothetical HIV vaccine scenarios were administered to determine HIV vaccine acceptability. Two-sided t-tests were performed, stratified by gender, to examine the association between vaccine acceptability and potential barriers and motivators. Barriers to HIV vaccine acceptability differed between men and women. For women, barriers to HIV vaccine acceptability were related to their intimate relationships (p <0.05), negative experiences with health care providers (p <0.05) and anticipated difficulties procuring insurance (p <0.01). Men were concerned that the vaccine would weaken the immune system (p <0.005) or would affect their HIV test results (p <0.05). Motivators for women included the ability to conceive a child without worrying about contracting HIV (p <0.10) and support from their spouse/significant other for being vaccinated (p <0.10). Motivators for men included feeling safer with sex partners (p <0.05) and social influence from friends to get vaccinated (p <0.005). Family support for HIV immunization was a motivator for both men and women (p <0.10). Gender-specific interventions may increase vaccine acceptability among men and women at elevated risk for HIV infection. Among women, interventions need to focus on addressing barriers due to gendered power dynamics in relationships and discrimination in health care. Among men, education that

Protein-energy malnutrition alters IgA responses to rotavirus vaccination and infection but does not impair vaccine efficacy in mice

PubMed Central

Maier, Elizabeth A.; Weage, Kristina J.; Guedes, Marjorie M; Denson, Lee A.; McNeal, Monica M.; Bernstein, David I.; Moore, Sean R.

2013-01-01

Background Conflicting evidence links malnutrition to the reduced efficacy of rotavirus vaccines in developing countries, where diarrhea and undernutrition remain leading causes of child deaths. Here, we adapted mouse models of rotavirus vaccination (rhesus rotavirus, RRV), rotavirus infection (EDIM), and protein-energy malnutrition (PEM) to test the hypothesis that undernutrition reduces rotavirus vaccine immunogenicity and efficacy. Methods We randomized wild type Balb/C dams with 3-day-old pups to a control diet (CD) or an isocaloric, multideficient regional basic diet (RBD) that produces PEM. At 3 weeks of age, we weaned CD and RBD pups to their dams’ diet and subrandomized weanlings to receive a single dose of either live oral rotavirus vaccine (RRV) or PBS. At 6 weeks of age, we orally challenged all groups with murine rotavirus (EDIM). Serum and stool specimens were collected before and after RRV and EDIM administration to measure viral shedding and antibody responses by ELISA. Results RBD pups and weanlings exhibited significant failure to thrive compared to age-matched CD mice (P<.0001). RRV vaccination induced higher levels of serum anti-RV IgA responses in RBD vs. CD mice (P<.0001). Vaccination protected CD and RBD mice equally against EDIM infection, as measured by viral shedding. In unvaccinated RBD mice, EDIM shedding peaked 1 day earlier (P<.05), however we detected no effects of undernutrition on viral clearance nor of infection on bodyweight. EDIM infection provoked higher anti-RV serum IgA levels in RBD vs. CD mice, regardless of vaccination (P<.0001). Last, RRV vaccination mitigated stool IgA responses to EDIM more in CD vs. RBD mice (P<.0001). Conclusions Despite modulated IgA responses to vaccination and infection, undernutrition does not impair rotavirus vaccine efficacy nor exacerbate infection in this mouse model of protein-energy malnutrition. Alternative models are needed to elucidate host-pathogen factors undermining rotavirus vaccine

Protein-energy malnutrition alters IgA responses to rotavirus vaccination and infection but does not impair vaccine efficacy in mice.

PubMed

Maier, Elizabeth A; Weage, Kristina J; Guedes, Marjorie M; Denson, Lee A; McNeal, Monica M; Bernstein, David I; Moore, Sean R

2013-12-17

Conflicting evidence links malnutrition to the reduced efficacy of rotavirus vaccines in developing countries, where diarrhea and undernutrition remain leading causes of child deaths. Here, we adapted mouse models of rotavirus vaccination (rhesus rotavirus, RRV), rotavirus infection (EDIM), and protein-energy malnutrition (PEM) to test the hypothesis that undernutrition reduces rotavirus vaccine immunogenicity and efficacy. We randomized wild type Balb/C dams with 3-day-old pups to a control diet (CD) or an isocaloric, multideficient regional basic diet (RBD) that produces PEM. At 3 weeks of age, we weaned CD and RBD pups to their dams' diet and subrandomized weanlings to receive a single dose of either live oral rotavirus vaccine (RRV) or PBS. At 6 weeks of age, we orally challenged all groups with murine rotavirus (EDIM). Serum and stool specimens were collected before and after RRV and EDIM administration to measure viral shedding and antibody responses by ELISA. RBD pups and weanlings exhibited significant failure to thrive compared to age-matched CD mice (P<.0001). RRV vaccination induced higher levels of serum anti-RV IgA responses in RBD vs. CD mice (P<.0001). Vaccination protected CD and RBD mice equally against EDIM infection, as measured by viral shedding. In unvaccinated RBD mice, EDIM shedding peaked 1 day earlier (P<.05), however we detected no effects of undernutrition on viral clearance nor of infection on bodyweight. EDIM infection provoked higher anti-RV serum IgA levels in RBD vs. CD mice, regardless of vaccination (P<.0001). Last, RRV vaccination mitigated stool IgA responses to EDIM more in CD vs. RBD mice (P<.0001). Despite modulated IgA responses to vaccination and infection, undernutrition does not impair rotavirus vaccine efficacy nor exacerbate infection in this mouse model of protein-energy malnutrition. Alternative models are needed to elucidate host-pathogen factors undermining rotavirus vaccine effectiveness in high-risk global settings

Detection of antigenic proteins expressed by lymphocystis virus as vaccine candidates in olive flounder, Paralichthys olivaceus (Temminck & Schlegel).

PubMed

Jang, H B; Kim, Y R; Cha, I S; Noh, S W; Park, S B; Ohtani, M; Hikima, J; Aoki, T; Jung, T S

2011-07-01

Although the major capsid proteins (MCPs) of lymphocystis disease virus (LCDV) have been characterized, little is known about the host-derived immune response to MCPs and other LCDV antigenic proteins. To identify antigenic proteins of LCDV that could be used as vaccine candidates in olive flounder, Paralichthys olivaceus, we analysed the viral proteins responsible for its virulence by applying immuno-proteomics. LCDV proteins were separated by one-dimensional gel electrophoresis, transferred to polyvinylidene difluoride membrane, and probed with homogeneous P. olivaceus antisera elicited by LCDV natural infection and vaccination with formalin-killed LCDV. Four immune-reactive proteins were obtained at 68-, 51-, 41- and 21 kDa using antisera collected from natural infection while two proteins at 51- and 21 kDa exhibited response to antisera from vaccinated fish, indicating that the latter two proteins have vaccine potential. Using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and nanoelectrospray MS/MS, the 51 and 21 kDa proteins were identified as MCP and an unknown protein, respectively. © 2011 Blackwell Publishing Ltd.

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparison of homologous and heterologous prime-boost vaccine approaches using Modified Vaccinia Ankara and soluble protein to induce neutralizing antibodies by the human cytomegalovirus pentamer complex in mice.

PubMed

Chiuppesi, Flavia; Wussow, Felix; Scharf, Louise; Contreras, Heidi; Gao, Han; Meng, Zhuo; Nguyen, Jenny; Barry, Peter A; Bjorkman, Pamela J; Diamond, Don J

2017-01-01

Since neutralizing antibodies (NAb) targeting the human cytomegalovirus (HCMV) pentamer complex (PC) potently block HCMV host cell entry, anti-PC NAb induction is thought to be important for a vaccine formulation to prevent HCMV infection. By developing a vaccine strategy based on soluble PC protein and using a previously generated Modified Vaccinia Ankara vector co-expressing all five PC subunits (MVA-PC), we compared HCMV NAb induction by homologous immunization using prime-boost vaccine regimen employing only PC protein or MVA-PC and heterologous immunization using prime-boost combinations of PC protein and MVA-PC. Utilizing a recently isolated anti-PC NAb, we produced highly pure soluble PC protein that displayed conformational and linear neutralizing epitopes, interfered with HCMV entry, and was recognized by antibodies induced by HCMV during natural infection. Mice vaccinated by different immunization routes with the purified PC protein in combination with a clinically approved adjuvant formulation elicited high-titer and durable HCMV NAb. While MVA-PC and soluble PC protein either alone or in combination elicited robust HCMV NAb, significantly different potencies of these vaccine approaches were observed in dependence on immunization schedule. Using only two immunizations, vaccination with MVA-PC alone or prime-boost combinations of MVA-PC and PC protein was significantly more effective in stimulating HCMV NAb than immunization with PC protein alone. In contrast, with three immunizations, NAb induced by soluble PC protein either alone or combined with two boosts of MVA-PC increased to levels that exceeded NAb titer stimulated by MVA-PC alone. These results provide insights into the potency of soluble protein and MVA to elicit NAb by the HCMV PC via homologous and heterologous prime-boost immunization, which may contribute to develop clinically deployable vaccine strategies to prevent HCMV infection.

Vaccination with the polymorphic membrane protein A reduces Chlamydia muridarum induced genital tract pathology.

PubMed

Müller, Tina; Becker, Elisabeth; Stallmann, Sonja; Waldhuber, Anna; Römmler-Dreher, Franziska; Albrecht, Simone; Mohr, Fabian; Hegemann, Johannes H; Miethke, Thomas

2017-05-15

Chlamydia trachomatis serovars D-K are one of the most frequent causes of sexually transmitted infections of the female genital tract, with possible complications such as hydrosalpinx, pelvic inflammatory disease, extra-uterine gravidity or infertility. We used the murine genital tract infection model with C. muridarum for vaccination studies and found that more than 70% of the infected mice suffered from uterus dilatations and/or hydrosalpinx. Systemic consequences of the vaginal infection were apparent by splenomegaly ten to fifteen days post infection. While cultivable microorganisms were detectable for the first 23days post infection, the first lesions of the genital tract developed at day 15, however, many lesions occurred later in the absence of cultivable bacteria. Lesions were not accompanied by pro-inflammatory cytokines such as IFNɣ, TNF and IL-6, since these cytokines were almost undetectable in the genital tract 43days post infection. To prevent genital tract lesions, we vaccinated mice with the polymorphic membrane protein (Pmp) A in combination with CpG-ODN 1826 as adjuvant. The vaccine lowered the chlamydial burden and the differences were significant at day 10 post infection but not later. More importantly the vaccine decreased the rate and severity of genital tract lesions. Interestingly, control vaccination with the protein ovalbumin plus CpG-ODN 1826 enhanced significantly the severity but not the rate of pathologic lesions, which was presumably caused by the activation of innate immune responses by the adjuvant in the absence of a C. muridarum-specific adaptive immune response. In summary, vaccination with recombinant PmpA plus CpG-ODN 1826 significantly reduced C. muridarum-induced tissue damage, however, CpG-ODN 1826 may aggravate C. muridarum-induced tissue injuries in the absence of a protective antigen. Copyright © 2017 Elsevier Ltd. All rights reserved.

Anti-botulism single-shot vaccine using chitosan for protein encapsulation by simple coacervation.

PubMed

Sari, Roger S; de Almeida, Anna Christina; Cangussu, Alex S R; Jorge, Edson V; Mozzer, Otto D; Santos, Hércules Otacílio; Quintilio, Wagner; Brandi, Igor Viana; Andrade, Viviane Aguiar; Miguel, Angelo Samir M; Sobrinho Santos, Eliane M

2016-12-01

The aim of the present study was to compare the potency and safety of vaccines against Clostridium botulinum (C. botulinum) type C and D formulated with chitosan as controlled release matrix and vaccines formulated in conventional manner using aluminum hydroxide. Parameters were established for the development of chitosan microspheres, using simple coacervation to standardize the use of this polymer in protein encapsulation for vaccine formulation. To formulate a single shot vaccine inactivated antigens of C. botulinum type C and D were used with original toxin titles equal to 5.2 and 6.2 log LD50/ml, respectively. For each antigen a chitosan based solution of 50 mL was prepared. Control vaccines were formulated by mixing toxoid type C and D with aluminum hydroxide [25% Al(OH) 3 , pH 6.3]. The toxoid sterility, innocuity and potency of vaccines were evaluated as stipulated by MAPA-BRASIL according to ministerial directive no. 23. Encapsulation efficiency of BSA in chitosan was 32.5-40.37%, while that the encapsulation efficiency to toxoid type C was 41,03% (1.94 mg/mL) and of the toxoid type D was 32.30% (1.82 mg/mL). The single shot vaccine formulated using chitosan for protein encapsulation through simple coacervation showed potency and safety similar to conventional vaccine currently used in Brazilian livestock (10 and 2 IU/mL against C. botulinum type C and D, respectively). The present work suggests that our single shot vaccine would be a good option as a cattle vaccine against these C. botulinum type C and D. Copyright © 2016 Elsevier Ltd. All rights reserved.

The live-attenuated yellow fever vaccine 17D induces broad and potent T cell responses against several viral proteins in Indian rhesus macaques--implications for recombinant vaccine design.

PubMed

Mudd, Philip A; Piaskowski, Shari M; Neves, Patricia C Costa; Rudersdorf, Richard; Kolar, Holly L; Eernisse, Christopher M; Weisgrau, Kim L; de Santana, Marlon G Veloso; Wilson, Nancy A; Bonaldo, Myrna C; Galler, Ricardo; Rakasz, Eva G; Watkins, David I

2010-09-01

The yellow fever vaccine 17D (YF17D) is one of the most effective vaccines. Its wide use and favorable safety profile make it a prime candidate for recombinant vaccines. It is believed that neutralizing antibodies account for a large measure of the protection afforded to YF17D-vaccinated individuals, however cytotoxic T lymphocyte (CTL) responses have been described in the setting of YF17D vaccination. YF17D is an ssRNA flavivirus that is translated as a full-length polyprotein, several domains of which pass into the lumen of the endoplasmic reticulum (ER). The processing and presentation machinery for MHC class I-restricted CTL responses favor cytoplasmic peptides that are transported into the ER by the transporter associated with antigen presentation proteins. In order to inform recombinant vaccine design, we sought to determine if YF17D-induced CTL responses preferentially targeted viral domains that remain within the cytoplasm. We performed whole YF17D proteome mapping of CTL responses in six Indian rhesus macaques vaccinated with YF17D using overlapping YF17D peptides. We found that the ER luminal E protein was the most immunogenic viral protein followed closely by the cytoplasmic NS3 and NS5 proteins. These results suggest that antigen processing and presentation in this model system is not preferentially affected by the subcellular location of the viral proteins that are the source of CTL epitopes. The data also suggest potential immunogenic regions of YF17D that could serve as the focus of recombinant T cell vaccine development.

The use of dissolved oxygen-controlled, fed-batch aerobic cultivation for recombinant protein subunit vaccine manufacturing.

PubMed

Farrell, Patrick; Sun, Jacob; Champagne, Paul-Philippe; Lau, Heron; Gao, Meg; Sun, Hong; Zeiser, Arno; D'Amore, Tony

2015-11-27

A simple "off-the-shelf" fed-batch approach to aerobic bacterial cultivation for recombinant protein subunit vaccine manufacturing is presented. In this approach, changes in the dissolved oxygen levels are used to adjust the nutrient feed rate (DO-stat), so that the desired dissolved oxygen level is maintained throughout cultivation. This enables high Escherichia coli cell densities and recombinant protein titers. When coupled to a kLa-matched scale-down model, process performance is shown to be consistent at the 2L, 20L, and 200L scales for two recombinant E. coli strains expressing different protein subunit vaccine candidates. Additionally, by mining historical DO-stat nutrient feeding data, a method to transition from DO-stat to a pre-determined feeding profile suitable for larger manufacturing scales without using feedback control is demonstrated at the 2L, 20L, and 200L scales. Copyright © 2015 Elsevier Ltd. All rights reserved.

Structure-based approach to rationally design a chimeric protein for an effective vaccine against Group B Streptococcus infections.

PubMed

Nuccitelli, Annalisa; Cozzi, Roberta; Gourlay, Louise J; Donnarumma, Danilo; Necchi, Francesca; Norais, Nathalie; Telford, John L; Rappuoli, Rino; Bolognesi, Martino; Maione, Domenico; Grandi, Guido; Rinaudo, C Daniela

2011-06-21

Structural vaccinology is an emerging strategy for the rational design of vaccine candidates. We successfully applied structural vaccinology to design a fully synthetic protein with multivalent protection activity. In Group B Streptococcus, cell-surface pili have aroused great interest because of their direct roles in virulence and importance as protective antigens. The backbone subunit of type 2a pilus (BP-2a) is present in six immunogenically different but structurally similar variants. We determined the 3D structure of one of the variants, and experimentally demonstrated that protective antibodies specifically recognize one of the four domains that comprise the protein. We therefore constructed a synthetic protein constituted by the protective domain of each one of the six variants and showed that the chimeric protein protects mice against the challenge with all of the type 2a pilus-carrying strains. This work demonstrates the power of structural vaccinology and will facilitate the development of an optimized, broadly protective pilus-based vaccine against Group B Streptococcus by combining the uniquely generated chimeric protein with protective pilin subunits from two other previously identified pilus types. In addition, this work describes a template procedure that can be followed to develop vaccines against other bacterial pathogens.

Optimization of heterologous DNA-prime, protein boost regimens and site of vaccination to enhance therapeutic immunity against human papillomavirus-associated disease.

PubMed

Peng, Shiwen; Qiu, Jin; Yang, Andrew; Yang, Benjamin; Jeang, Jessica; Wang, Joshua W; Chang, Yung-Nien; Brayton, Cory; Roden, Richard B S; Hung, Chien-Fu; Wu, T-C

2016-01-01

Human papillomavirus (HPV) has been identified as the primary etiologic factor of cervical cancer as well as subsets of anogenital and oropharyngeal cancers. The two HPV viral oncoproteins, E6 and E7, are uniquely and consistently expressed in all HPV infected cells and are therefore promising targets for therapeutic vaccination. Both recombinant naked DNA and protein-based HPV vaccines have been demonstrated to elicit HPV-specific CD8+ T cell responses that provide therapeutic effects against HPV-associated tumor models. Here we examine the immunogenicity in a preclinical model of priming with HPV DNA vaccine followed by boosting with filterable aggregates of HPV 16 L2E6E7 fusion protein (TA-CIN). We observed that priming twice with an HPV DNA vaccine followed by a single TA-CIN booster immunization generated the strongest antigen-specific CD8+ T cell response compared to other prime-boost combinations tested in C57BL/6 mice, whether naïve or bearing the HPV16 E6/E7 transformed syngeneic tumor model, TC-1. We showed that the magnitude of antigen-specific CD8+ T cell response generated by the DNA vaccine prime, TA-CIN protein vaccine boost combinatorial strategy is dependent on the dose of TA-CIN protein vaccine. In addition, we found that a single booster immunization comprising intradermal or intramuscular administration of TA-CIN after priming twice with an HPV DNA vaccine generated a comparable boost to E7-specific CD8+ T cell responses. We also demonstrated that the immune responses elicited by the DNA vaccine prime, TA-CIN protein vaccine boost strategy translate into potent prophylactic and therapeutic antitumor effects. Finally, as seen for repeat TA-CIN protein vaccination, we showed that the heterologous DNA prime and protein boost vaccination strategy is well tolerated by mice. Our results provide rationale for future clinical testing of HPV DNA vaccine prime, TA-CIN protein vaccine boost immunization regimen for the control of HPV-associated diseases.

Vaccination with Recombinant Cryptococcus Proteins in Glucan Particles Protects Mice against Cryptococcosis in a Manner Dependent upon Mouse Strain and Cryptococcal Species.

PubMed

Specht, Charles A; Lee, Chrono K; Huang, Haibin; Hester, Maureen M; Liu, Jianhua; Luckie, Bridget A; Torres Santana, Melanie A; Mirza, Zeynep; Khoshkenar, Payam; Abraham, Ambily; Shen, Zu T; Lodge, Jennifer K; Akalin, Ali; Homan, Jane; Ostroff, Gary R; Levitz, Stuart M

2017-11-28

Development of a vaccine to protect against cryptococcosis is a priority given the enormous global burden of disease in at-risk individuals. Using glucan particles (GPs) as a delivery system, we previously demonstrated that mice vaccinated with crude Cryptococcus -derived alkaline extracts were protected against lethal challenge with Cryptococcus neoformans and Cryptococcus gattii The goal of the present study was to identify protective protein antigens that could be used in a subunit vaccine. Using biased and unbiased approaches, six candidate antigens (Cda1, Cda2, Cda3, Fpd1, MP88, and Sod1) were selected, recombinantly expressed in Escherichia coli , purified, and loaded into GPs. Three mouse strains (C57BL/6, BALB/c, and DR4) were then vaccinated with the antigen-laden GPs, following which they received a pulmonary challenge with virulent C. neoformans and C. gattii strains. Four candidate vaccines (GP-Cda1, GP-Cda2, GP-Cda3, and GP-Sod1) afforded a significant survival advantage in at least one mouse model; some vaccine combinations provided added protection over that seen with either antigen alone. Vaccine-mediated protection against C. neoformans did not necessarily predict protection against C. gattii Vaccinated mice developed pulmonary inflammatory responses that effectively contained the infection; many surviving mice developed sterilizing immunity. Predicted T helper cell epitopes differed between mouse strains and in the degree to which they matched epitopes predicted in humans. Thus, we have discovered cryptococcal proteins that make promising candidate vaccine antigens. Protection varied depending on the mouse strain and cryptococcal species, suggesting that a successful human subunit vaccine will need to contain multiple antigens, including ones that are species specific. IMPORTANCE The encapsulated fungi Cryptococcus neoformans and Cryptococcus gattii are responsible for nearly 200,000 deaths annually, mostly in immunocompromised individuals. An

Epitope Mapping of Avian Influenza M2e Protein: Different Species Recognise Various Epitopes

PubMed Central

Hasan, Noor Haliza; Ignjatovic, Jagoda; Tarigan, Simson; Peaston, Anne; Hemmatzadeh, Farhid

2016-01-01

A common approach for developing diagnostic tests for influenza virus detection is the use of mouse or rabbit monoclonal and/or polyclonal antibodies against a target antigen of the virus. However, comparative mapping of the target antigen using antibodies from different animal sources has not been evaluated before. This is important because identification of antigenic determinants of the target antigen in different species plays a central role to ensure the efficiency of a diagnostic test, such as competitive ELISA or immunohistochemistry-based tests. Interest in the matrix 2 ectodomain (M2e) protein of avian influenza virus (AIV) as a candidate for a universal vaccine and also as a marker for detection of virus infection in vaccinated animals (DIVA) is the rationale for the selection of this protein for comparative mapping evaluation. This study aimed to map the epitopes of the M2e protein of avian influenza virus H5N1 using chicken, mouse and rabbit monoclonal or monospecific antibodies. Our findings revealed that rabbit antibodies (rAbs) recognized epitope 6EVETPTRN13 of the M2e, located at the N-terminal of the protein, while mouse (mAb) and chicken antibodies (cAbs) recognized epitope 10PTRNEWECK18, located at the centre region of the protein. The findings highlighted the difference between the M2e antigenic determinants recognized by different species that emphasized the importance of comparative mapping of antibody reactivity from different animals to the same antigen, especially in the case of multi-host infectious agents such as influenza. The findings are of importance for antigenic mapping, as well as diagnostic test and vaccine development. PMID:27362795

Severe acute respiratory syndrome (SARS) S protein production in plants: Development of recombinant vaccine

PubMed Central

Pogrebnyak, Natalia; Golovkin, Maxim; Andrianov, Vyacheslav; Spitsin, Sergei; Smirnov, Yuriy; Egolf, Richard; Koprowski, Hilary

2005-01-01

In view of a recent spread of severe acute respiratory syndrome (SARS), there is a high demand for production of a vaccine to prevent this disease. Recent studies indicate that SARS-coronavirus (CoV) spike protein (S protein) and its truncated fragments are considered the best candidates for generation of the recombinant vaccine. Toward the development of a safe, effective, and inexpensive vaccine candidate, we have expressed the N-terminal fragment of SARS-CoV S protein (S1) in tomato and low-nicotine tobacco plants. Incorporation of the S1 fragment into plant genomes as well as its transcription was confirmed by PCR and RT-PCR analyses. High levels of expression of recombinant S1 protein were observed in several transgenic lines by Western blot analysis using specific antibodies. Plant-derived antigen was evaluated to induce the systemic and mucosal immune responses in mice. Mice showed significantly increased levels of SARS-CoV-specific IgA after oral ingestion of tomato fruits expressing S1 protein. Sera of mice parenterally primed with tobacco-derived S1 protein revealed the presence of SARS-CoV-specific IgG as detected by Western blot and ELISA analysis. PMID:15956182

Severe acute respiratory syndrome (SARS) S protein production in plants: development of recombinant vaccine.

PubMed

Pogrebnyak, Natalia; Golovkin, Maxim; Andrianov, Vyacheslav; Spitsin, Sergei; Smirnov, Yuriy; Egolf, Richard; Koprowski, Hilary

2005-06-21

In view of a recent spread of severe acute respiratory syndrome (SARS), there is a high demand for production of a vaccine to prevent this disease. Recent studies indicate that SARS-coronavirus (CoV) spike protein (S protein) and its truncated fragments are considered the best candidates for generation of the recombinant vaccine. Toward the development of a safe, effective, and inexpensive vaccine candidate, we have expressed the N-terminal fragment of SARS-CoV S protein (S1) in tomato and low-nicotine tobacco plants. Incorporation of the S1 fragment into plant genomes as well as its transcription was confirmed by PCR and RT-PCR analyses. High levels of expression of recombinant S1 protein were observed in several transgenic lines by Western blot analysis using specific antibodies. Plant-derived antigen was evaluated to induce the systemic and mucosal immune responses in mice. Mice showed significantly increased levels of SARS-CoV-specific IgA after oral ingestion of tomato fruits expressing S1 protein. Sera of mice parenterally primed with tobacco-derived S1 protein revealed the presence of SARS-CoV-specific IgG as detected by Western blot and ELISA analysis.

A human papillomavirus type 16 vaccine by oral delivery of L1 protein.

PubMed

Sasagawa, Toshiyuki; Tani, Mayuko; Basha, Walid; Rose, Robert C; Tohda, Hideki; Giga-Hama, Yuko; Azar, Khadijeh K; Yasuda, Hideyo; Sakai, Akemi; Inoue, Masaki

2005-06-01

To establish an edible HPV16 vaccine, we constructed a recombinant HPV16 L1-expressing Schizosaccharomyces pombe yeast strain (HPV16L1 yeast). A preliminary study revealed that freeze-dried yeast cells could be delivered safely, and were digested in the mouse intestine. The freeze-dried HPV16 L1 yeast was administered orally as an edible vaccine, with or without the mucosal adjuvant heat-labile toxin LT (R192G), to 18 female BALB/c mice. After the third immunization, none of the mice that received the edible HPV16 vaccine showed specific antibody responses, whereas all of the positive controls that were administered intranasally with 5 microg of HPV16-virus-like particles (VLP) had serum IgG, and genital IgA and IgG that reacted with HPV16-VLP in enzyme-linked immunosorbent assays (ELISAs). When a suboptimal dose (1 microg) of HPV16-VLP was administered to all the mice, including the negative control mice, 50% of the mice that were pre-immunized with the edible HPV16 vaccine showed positive serum IgG responses, while none of the negative controls showed any response. Vaginal IgG and IgA antibodies were also elicited in 33 and 39%, respectively, of the mice that were given with the edible HPV16 vaccine and the intranasal boost. All of the antibodies reacted more strongly to intact HPV16-VLP than to denatured HPV16-L1 protein suggesting that the edible vaccine primes for antibody responses against conformation-dependent epitopes. The inclusion of adjuvant in the vaccine formulation marginally increased the genital IgA response (P=0.06). HPV16-L1 protein in the yeast might induce tolerance in the vaccinated animals that could be recovered by intranasal boosting with a suboptimal dose of HPV-VLP. This freeze-dried yeast system may be useful as an oral delivery of HPV 16 L1 protein.

Evaluation of fusion protein cleavage site sequences of Newcastle disease virus in genotype matched vaccines.

PubMed

Kim, Shin-Hee; Chen, Zongyan; Yoshida, Asuka; Paldurai, Anandan; Xiao, Sa; Samal, Siba K

2017-01-01

Newcastle disease virus (NDV) causes a devastating poultry disease worldwide. Frequent outbreaks of NDV in chickens vaccinated with conventional live vaccines suggest a need to develop new vaccines that are genetically matched against circulating NDV strains, such as the genotype V virulent strains currently circulating in Mexico and Central America. In this study, a reverse genetics system was developed for the virulent NDV strain Mexico/01/10 strain and used to generate highly attenuated vaccine candidates by individually modifying the cleavage site sequence of fusion (F) protein. The cleavage site sequence of parental virus was individually changed to those of the avirulent NDV strain LaSota and other serotypes of avian paramyxoviruses (APMV serotype-2, -3, -4, -6, -7, -8, and -9). In general, these mutations affected cell-to-cell fusion activity in vitro and the efficiency of the F protein cleavage and made recombinant Mexico/01/10 (rMex) virus highly attenuated in chickens. When chickens were immunized with the rMex mutant viruses and challenged with the virulent parent virus, there was reduced challenge virus shedding compared to birds immunized with the heterologous vaccine strain LaSota. Among the vaccine candidates, rMex containing the cleavage site sequence of APMV-2 induced the highest neutralizing antibody titer and completely protected chickens from challenge virus shedding. These results show the role of the F protein cleavage site sequence of each APMV type in generating genotype V-matched vaccines and the efficacy of matched vaccine strains to provide better protection against NDV strains currently circulating in Mexico.

Ebola virus glycoprotein Fc fusion protein confers protection against lethal challenge in vaccinated mice

PubMed Central

Konduru, Krishnamurthy; Bradfute, Steven B.; Jacques, Jerome; Manangeeswaran, Mohanraj; Nakamura, Siham; Morshed, Sufi; Wood, Steven C.; Bavari, Sina

2011-01-01

Ebola virus is a Filoviridae that causes hemorrhagic fever in humans and induces high morbidity and mortality rates. Filoviruses are classified as "Category A bioterrorism agents", and currently there are no licensed therapeutics or vaccines to treat and prevent infection. The Filovirus glycoprotein (GP) is sufficient to protect individuals against infection, and several vaccines based on GP are under development including recombinant adenovirus, parainfluenza virus, Venezuelan equine encephalitis virus, vesicular stomatitis virus (VSV) and virus-like particles. Here we describe the development of a GP Fc fusion protein as a vaccine candidate. We expressed the extracellular domain of the Zaire Ebola virus (ZEBOV) GP fused to the Fc fragment of human IgG1 (ZEBOVGP-Fc) in mammalian cells and showed that GP undergoes the complex furin cleavage and processing observed in the native membrane-bound GP. Mice immunized with ZEBOVGP-Fc developed T-cell immunity against ZEBOV GP and neutralizing antibodies against replication-competent VSV-G deleted recombinant VSV containing ZEBOV GP. The ZEBOVGP-Fc vaccinated mice were protected against challenge with a lethal dose of ZEBOV. These results show that vaccination with the ZEBOVGP-Fc fusion protein alone without the need of a viral vector or assembly into virus-like particles is sufficient to induce protective immunity against ZEBOV in mice. Our data suggested that Filovirus GP Fc fusion proteins could be developed as a simple, safe, efficacious, and cost effective vaccine against Filovirus infection for human use. PMID:21329775

Virus-like particles vaccine containing Clonorchis sinensis tegumental protein induces partial protection against Clonorchis sinensis infection.

PubMed

Lee, Dong-Hun; Kim, Ah-Ra; Lee, Su-Hwa; Quan, Fu-Shi

2017-12-29

Human clonorchiasis, caused by the infection of Clonorchis sinensis, is one of the major health problems in Southeast Asia. However, vaccine efficacy against C. sinensis infection remains largely unknown. In this study, for the first time, we generated virus-like particles (VLPs) vaccine containing the C. sinensis tegumental protein 22.3 kDa (CsTP 22.3) and the influenza matrix protein (M1) as a core protein, and investigated the vaccine efficacy in Sprague-Dawley rats. Intranasal immunization of VLPs vaccine induced C. sinensis-specific IgG, IgG2a and IgG2c in the sera and IgA responses in the feces and intestines. Notably, upon challenge infection with C. sinensis metacercariae, significantly lower adult worm loads (70.2%) were measured in the liver of rats immunized with VLPs, compared to those of naïve rats. Furthermore, VLPs immunization induced antibody secreting cells (ASC) responses and CD4+/CD8+ T cell responses in the spleen. Our results indicated that VLPs vaccine containing C. sinensis CsTP 22.3 kDa provided partial protection against C. sisnensis infection. Thus, VLPs could be a potential vaccine candidate against C. sinensis.

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

Impact of protein D-containing pneumococcal conjugate vaccines on non-typeable Haemophilus influenzae acute otitis media and carriage.

PubMed

Clarke, Christopher; Bakaletz, Lauren O; Ruiz-Guiñazú, Javier; Borys, Dorota; Mrkvan, Tomas

2017-07-01

Protein D-containing vaccines may decrease acute otitis media (AOM) burden and nasopharyngeal carriage of non-typeable Haemophilus influenzae (NTHi). Protein D-containing pneumococcal conjugate vaccine PHiD-CV (Synflorix, GSK Vaccines) elicits robust immune responses against protein D. However, the phase III Clinical Otitis Media and PneumoniA Study (COMPAS), assessing PHiD-CV efficacy against various pneumococcal diseases, was not powered to demonstrate efficacy against NTHi; only trends of protective efficacy against NTHi AOM in children were shown. Areas covered: This review aims to consider all evidence available to date from pre-clinical and clinical phase III studies together with further evidence emerging from post-marketing studies since PHiD-CV has been introduced into routine clinical practice worldwide, to better describe the clinical utility of protein D in preventing AOM due to NTHi and its impact on NTHi nasopharyngeal carriage. Expert commentary: Protein D is an effective carrier protein in conjugate vaccines and evidence gathered from pre-clinical, clinical and observational studies suggest that it also elicits immune response that can help to reduce the burden of AOM due to NTHi. There remains a need to develop improved vaccines for prevention of NTHi disease, which could be achieved by combining protein D with other antigens.

Increase in DNA vaccine efficacy by virosome delivery and co-expression of a cytolytic protein.

PubMed

Gargett, Tessa; Grubor-Bauk, Branka; Miller, Darren; Garrod, Tamsin; Yu, Stanley; Wesselingh, Steve; Suhrbier, Andreas; Gowans, Eric J

2014-06-01

The potential of DNA vaccines has not been realised due to suboptimal delivery, poor antigen expression and the lack of localised inflammation, essential for antigen presentation and an effective immune response to the immunogen. Initially, we examined the delivery of a DNA vaccine encoding a model antigen, luciferase (LUC), to the respiratory tract of mice by encapsulation in a virosome. Virosomes that incorporated influenza virus haemagglutinin effectively delivered DNA to cells in the mouse respiratory tract and resulted in antigen expression and systemic and mucosal immune responses to the immunogen after an intranasal (IN) prime/intradermal (ID) boost regimen, whereas a multidose ID regimen only generated systemic immunity. We also examined systemic immune responses to LUC after ID vaccination with a DNA vaccine, which also encoded one of the several cytolytic or toxic proteins. Although the herpes simplex virus thymidine kinase, in the presence of the prodrug, ganciclovir, resulted in cell death, this failed to increase the humoral or cell-mediated immune responses. In contrast, the co-expression of LUC with the rotavirus non-structural protein 4 (NSP4) protein or a mutant form of mouse perforin, proteins which are directly cytolytic, resulted in increased LUC-specific humoral and cell-mediated immunity. On the other hand, co-expression of LUC with diphtheria toxin subunit A or overexpression of perforin or NSP4 resulted in a lower level of immunity. In summary, the efficacy of DNA vaccines can be improved by targeted IN delivery of DNA or by the induction of cell death in vaccine-targeted cells after ID delivery.

Preclinical evaluation of bacterially produced RSV-G protein vaccine: Strong protection against RSV challenge in cotton rat model.

PubMed

Fuentes, Sandra; Klenow, Laura; Golding, Hana; Khurana, Surender

2017-02-10

In current study, we evaluated the safety and protective efficacy of recombinant unglycosylated RSV G protein ectodomain produced in E. coli (in presence and absence of oil-in-water adjuvant) in a preclinical RSV susceptible cotton rat challenge model compared to formaldehyde inactivated RSV (FI-RSV) and live RSV experimental infection. The adjuvanted G protein vaccine induced robust neutralization antibody responses comparable to those generated by live RSV infection. Importantly, adjuvanted G protein significantly reduced viral loads in both the lungs and nose at early time points following viral challenge. Antibody kinetics determined by Surface Plasmon Resonance showed that adjuvanted G generated 10-fold higher G-binding antibodies compared to non-adjvuanted G vaccine and live RSV infection, which correlated strongly with both neutralization titers and viral load titers in the nose and lungs post-viral challenge. Antibody diversity analysis revealed immunodominant antigenic sites in the N- and C-termini of the RSV-G protein, that were boosted >10-fold by adjuvant and inversely correlated with viral load titers. Enhanced lung pathology was observed only in animals vaccinated with FI-RSV, but not in animals vaccinated with unadjuvanted or adjuvanted RSV-G vaccine after viral challenge. The bacterially produced unglycosylated G protein could be developed as a protective vaccine against RSV disease.

Preclinical evaluation of bacterially produced RSV-G protein vaccine: Strong protection against RSV challenge in cotton rat model

PubMed Central

Fuentes, Sandra; Klenow, Laura; Golding, Hana; Khurana, Surender

2017-01-01

In current study, we evaluated the safety and protective efficacy of recombinant unglycosylated RSV G protein ectodomain produced in E. coli (in presence and absence of oil-in-water adjuvant) in a preclinical RSV susceptible cotton rat challenge model compared to formaldehyde inactivated RSV (FI-RSV) and live RSV experimental infection. The adjuvanted G protein vaccine induced robust neutralization antibody responses comparable to those generated by live RSV infection. Importantly, adjuvanted G protein significantly reduced viral loads in both the lungs and nose at early time points following viral challenge. Antibody kinetics determined by Surface Plasmon Resonance showed that adjuvanted G generated 10-fold higher G-binding antibodies compared to non-adjvuanted G vaccine and live RSV infection, which correlated strongly with both neutralization titers and viral load titers in the nose and lungs post-viral challenge. Antibody diversity analysis revealed immunodominant antigenic sites in the N- and C-termini of the RSV-G protein, that were boosted >10-fold by adjuvant and inversely correlated with viral load titers. Enhanced lung pathology was observed only in animals vaccinated with FI-RSV, but not in animals vaccinated with unadjuvanted or adjuvanted RSV-G vaccine after viral challenge. The bacterially produced unglycosylated G protein could be developed as a protective vaccine against RSV disease. PMID:28186208

E Protein Domain III Determinants of Yellow Fever Virus 17D Vaccine Strain Enhance Binding to Glycosaminoglycans, Impede Virus Spread, and Attenuate Virulence▿

PubMed Central

Lee, Eva; Lobigs, Mario

2008-01-01

The yellow fever virus (YFV) 17D strain is one of the most effective live vaccines for human use, but the in vivo mechanisms for virulence attenuation of the vaccine and the corresponding molecular determinants remain elusive. The vaccine differs phenotypically from wild-type YFV by the loss of viscerotropism, despite replicative fitness in cell culture, and genetically by 20 amino acid changes predominantly located in the envelope (E) protein. We show that three residues in E protein domain III inhibit spread of 17D in extraneural tissues and attenuate virulence in type I/II interferon-deficient mice. One of these residues (Arg380) is a dominant glycosaminoglycan-binding determinant, which mainly accounts for more rapid in vivo clearance of 17D from the bloodstream in comparison to 17D-derived variants with wild-type-like E protein. While other mutations will account for loss of neurotropism and phenotypic stability, the described impact of E protein domain III changes on virus dissemination and virulence is the first rational explanation for the safety of the 17D vaccine in humans. PMID:18400851

E protein domain III determinants of yellow fever virus 17D vaccine strain enhance binding to glycosaminoglycans, impede virus spread, and attenuate virulence.

PubMed

Lee, Eva; Lobigs, Mario

2008-06-01

The yellow fever virus (YFV) 17D strain is one of the most effective live vaccines for human use, but the in vivo mechanisms for virulence attenuation of the vaccine and the corresponding molecular determinants remain elusive. The vaccine differs phenotypically from wild-type YFV by the loss of viscerotropism, despite replicative fitness in cell culture, and genetically by 20 amino acid changes predominantly located in the envelope (E) protein. We show that three residues in E protein domain III inhibit spread of 17D in extraneural tissues and attenuate virulence in type I/II interferon-deficient mice. One of these residues (Arg380) is a dominant glycosaminoglycan-binding determinant, which mainly accounts for more rapid in vivo clearance of 17D from the bloodstream in comparison to 17D-derived variants with wild-type-like E protein. While other mutations will account for loss of neurotropism and phenotypic stability, the described impact of E protein domain III changes on virus dissemination and virulence is the first rational explanation for the safety of the 17D vaccine in humans.

Sperm fibrous sheath proteins: a potential new class of target antigens for use in human therapeutic cancer vaccines

PubMed Central

Chiriva-Internati, Maurizio; Cobos, Everardo; Da Silva, Diane M.

2008-01-01

Cancer vaccines have been demonstrated to be a promising strategy for treating human neoplastic disease, but one of the limitations of these vaccines remains the paucity of target antigens to which to direct an effective immune response. We hypothesize that sperm fibrous sheath proteins may be a new class of useful antigens for developing successful cancer vaccines. This hypothesis is supported by the expression of two sperm fibrous sheath proteins, called sperm protein 17 and calcium-binding tyrosine-phosphorylation regulated protein, in tumors of unrelated histological origin and their capability to induce T cell-based immune responses. PMID:18433090

Efficacy of recombinant protein vaccines for protection against Nocardia seriolae infection in the largemouth bass Micropterus salmoides.

PubMed

Ho, Ping-Yueh; Chen, Yao-Chung; Maekawa, Shun; Hu, Hsiang-Hui; Tsai, An-Wei; Chang, Yung-Fu; Wang, Pei-Chi; Chen, Shih-Chu

2018-07-01

A reverse vaccinology-based survey of potent antigens associated with fish nocardiosis was conducted using the largemouth bass, Micropterus salmoides, with an aim to develop subunit vaccines. The antigens selected from the virulent strain Nocardia seriolae 961113 include the gene products of NGL2579 (GAPDH), NGL5701 (MMP), NGL4377 (OCTase), NGL4486 (ABC transporter), NGL3372 (LLE), NGL3388 (GHf10), NGL6627 (Antigen-85), NGL6696 (Esterase), and NGL6936 (CBP). These antigens were heterologously expressed in E. coli BL21 (DE3) for recombinant protein production. Then fish were vaccinated was these antigens, boosted at 2 weeks, and challenged with N. seriolae at 6 weeks after vaccination. The relative protection survival assay revealed high and significant protection efficacies of 94.45, 50.00, and 44.45 in fish that received the NGL3388 (GHf10), NGL6936 (CBP), and NGL3372 (LLE) vaccines, respectively. There were no apparent relationships or differences in tissue lesions among the administered vaccines. The serum titers against the bacterial preparations were higher for all vaccinated groups than for the control group at 4 weeks after immunization. However, no significant difference in serum titer was found at 6 weeks after immunization. The results of this study demonstrate that subunit vaccines against fish nocardiosis have differential effects, but are highly promising for nocardial prophylaxis. Copyright © 2018 Elsevier Ltd. All rights reserved.

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

Identification of Plasmodium falciparum reticulocyte binding protein homologue 5-interacting protein, PfRipr, as a highly conserved blood-stage malaria vaccine candidate.

PubMed

Ntege, Edward H; Arisue, Nobuko; Ito, Daisuke; Hasegawa, Tomoyuki; Palacpac, Nirianne M Q; Egwang, Thomas G; Horii, Toshihiro; Takashima, Eizo; Tsuboi, Takafumi

2016-11-04

Genetic variability in Plasmodium falciparum malaria parasites hampers current malaria vaccine development efforts. Here, we hypothesize that to address the impact of genetic variability on vaccine efficacy in clinical trials, conserved antigen targets should be selected to achieve robust host immunity across multiple falciparum strains. Therefore, suitable vaccine antigens should be assessed for levels of polymorphism and genetic diversity. Using a total of one hundred and two clinical isolates from a region of high malaria transmission in Uganda, we analyzed extent of polymorphism and genetic diversity in four recently reported novel blood-stage malaria vaccine candidate proteins: Rh5 interacting protein (PfRipr), GPI anchored micronemal antigen (PfGAMA), rhoptry-associated leucine zipper-like protein 1 (PfRALP1) and Duffy binding-like merozoite surface protein 1 (PfMSPDBL1). In addition, utilizing the wheat germ cell-free system, we expressed recombinant proteins for the four candidates based on P. falciparum laboratory strain 3D7 sequences, immunized rabbits to obtain specific antibodies (Abs) and performed functional growth inhibition assay (GIA). The GIA activity of the raised Abs was demonstrated using both homologous 3D7 and heterologous FVO strains in vitro. Both pfripr and pfralp1 are less polymorphic but the latter is comparatively more diverse, with varied number of regions having insertions and deletions, asparagine and 6-mer repeats in the coding sequences. Pfgama and pfmspdbl1 are polymorphic and genetically diverse among the isolates with antibodies against the 3D7-based recombinant PfGAMA and PfMSPDBL1 inhibiting merozoite invasion only in the 3D7 but not FVO strain. Moreover, although Abs against the 3D7-based recombinant PfRipr and PfRALP1 proteins potently inhibited merozoite invasion of both 3D7 and FVO, the GIA activity of anti-PfRipr was much higher than that of anti-PfRALP1. Thus, PfRipr is regarded as a promising blood-stage vaccine

Introducing dengue vaccine: Implications for diagnosis in dengue vaccinated subjects.

PubMed

Alagarasu, Kalichamy

2016-05-27

Diagnosis of dengue virus infections is complicated by preference for different diagnostic tests in different post onset days of illness and the presence of multiple serotypes leading to secondary and tertiary infections. The sensitivity of the most commonly employed diagnostic assays such as anti dengue IgM capture (MAC) ELISA and non structural protein (NS) 1 capture ELISA are lower in secondary and subsequent infections. Introduction of dengue vaccine in endemic regions will affect the way how dengue is diagnosed in vaccinated subjects. This viewpoint article discusses implications of introduction of dengue vaccine on the diagnosis of dengue infections in vaccinated subjects and the strategies that are needed to tackle the issue. Copyright © 2016 Elsevier Ltd. All rights reserved.

Factor H-binding protein, a unique meningococcal vaccine antigen.

PubMed

Pizza, Mariagrazia; Donnelly, John; Rappuoli, Rino

2008-12-30

GNA1870, also named factor H-binding protein (fHbp) or rLP-2086, is a genome-derived antigen and one of the components of a rationally designed vaccine against Neisseria meningitidis serogroup B, which has entered phase III clinical trials. It has been classified into three main non-cross-protective variant groups. GNA1870 has also been termed fHbp because of its ability to bind factor H, a key regulatory component of the alternative complement pathway. fHbp is important for survival in human blood, human sera, and in presence of antimicrobial peptides, independently of its expression level. All these properties make fHbp a unique vaccine antigen.

Heterogeneity in the A33 protein impacts the cross-protective efficacy of a candidate smallpox DNA vaccine.

PubMed

Golden, Joseph W; Hooper, Jay W

2008-07-20

We previously developed a gene-based vaccine, termed 4pox, which targets four orthopoxvirus proteins (A33, L1, B5, and A27). Because any subunit orthopoxvirus vaccine must protect against multiple species of orthopoxviruses, we are interested in understanding the cross-protective potential of our 4pox vaccine target immunogens. In our current studies, we focused on the A33 immunogen. We found one monoclonal antibody against A33, MAb-1G10, which could not bind the monkeypox virus A33 ortholog, A35. MAb-1G10 binding could be rescued if A35 amino acids 118 and 120 were substituted with those from A33. MAb-1G10 has been shown to protect mice from VACV challenge, thus our findings indicated a protective epitope differs among orthopoxviruses. Accordingly, we tested the cross-protective efficacy of a DNA vaccine consisting of A35R against VACV challenge and compared it to vaccination with A33R DNA. Mice vaccinated with A35R had greater mortality and more weight loss compared to those vaccinated with A33R. These findings demonstrate that despite high homology between A33R orthologs, amino acid differences can impact cross-protection. Furthermore, our results caution that adequate cross-protection by any pan-orthopoxvirus subunit vaccine will require not only careful evaluation of cross-protective immunity, but also of targeting of multiple orthopoxvirus immunogens.

Safety and immunogenicity of a prototype anti-Chlamydia pecorum recombinant protein vaccine in lambs and pregnant ewes.

PubMed

Desclozeaux, Marion; Jelocnik, Martina; Whitting, Katrina; Saifzadeh, Siamak; Bommana, Sankhya; Potter, Andrew; Gerdts, Volker; Timms, Peter; Polkinghorne, Adam

2017-06-14

Arthritis and kerato-conjunctivitis caused by Chlamydia pecorum in lambs are difficult to diagnose and treat. We tested the ability of a prototype C. pecorum vaccine (SC-vaccine), comprised of C. pecorum major outer membrane protein (MOMP-G) and polymorphic membrane protein G (PmpG), to trigger a Chlamydia-specific humoral and cell-mediated immune response in lambs and pregnant ewes. Vaccinations with the SC-vaccine (one and two injections) were very well tolerated by all ewes and lambs. Although the overall immune responses of ewes to SC-vaccination was poor, their lambs showed stronger antigen-specific immune response than lambs from control vaccine ewes. SC-vaccination in lambs triggered production of systemic anti-MOMP-G and anti-PmpG IgG antibodies and secretory IgA in the ocular mucosa. Double vaccination caused statistically significant increases in the height and duration of the humoral response. Antigen-specific IFN-γ was produced in the peripheral blood mononuclear cells of vaccinated lambs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Structure-based energetics of protein interfaces guide Foot-and-Mouth Disease virus vaccine design

PubMed Central

Scott, Katherine; Burman, Alison; Loureiro, Silvia; Ren, Jingshan; Porta, Claudine; Ginn, Helen M.; Jackson, Terry; Perez-Martin, Eva; Siebert, C. Alistair; Paul, Guntram; Huiskonen, Juha T.; Jones, Ian M.; Esnouf, Robert M.; Fry, Elizabeth E.; Maree, Francois F.; Charleston, Bryan; Stuart, David I.

2018-01-01

Summary Virus capsids are primed for disassembly yet capsid integrity is key to generating a protective immune response. Here we devise a computational method to assess relative stability of protein-protein interfaces and use it to design improved candidate vaccines for two of the least stable, but globally important, serotypes of Foot-and-Mouth Disease virus (FMDV), O and SAT2. FMDV capsids comprise identical pentameric protein subunits held together by tenuous non-covalent interactions, and are often unstable. Chemically inactivated or recombinant empty capsids, which could form the basis of future vaccines, are even less stable than live virus. We use a novel restrained molecular dynamics strategy, to rank mutations predicted to strengthen the pentamer interfaces to produce stabilized capsids. Structural analyses and stability assays confirmed the predictions, and vaccinated animals generated improved neutralising antibody responses to stabilised particles over parental viruses and wild-type capsids. PMID:26389739

A lentiviral vaccine expressing KMP11-HASPB fusion protein increases immune response to Leishmania major in BALB/C.

PubMed

Mortazavidehkordi, Nahid; Fallah, Ali; Abdollahi, Abbas; Kia, Vahid; Khanahmad, Hossein; Najafabadi, Zahra Ghayour; Hashemi, Nooshin; Estiri, Bahareh; Roudbari, Zahra; Najafi, Ali; Farjadfar, Akbar; Hejazi, Seyed Hossein

2018-05-29

Hydrophilic acylated surface protein B (HASPB) is an immunogenic Leishmania-specific protein that antibodies are produced against it in the sera of Leishmania-infected individuals. Kinetoplastid membrane protein 11 (KMP11) is another Leishmania antigen and considered as the suitable candidate for vaccine development Leishmaniasis. It is a highly conserved surface protein expressed in both promastigotes and amastigotes. In this study, KMP11 and HASPB coding sequences were cloned into a pCDH-cGFP lentiviral vector as a fusion protein to be used as a DNA vaccine against L. major. The KMP11-HASPB fusion protein was successfully expressed as evidenced by RT-PCR and Western blot assays. The effect of the vaccine was determined by evaluating the level of IFN-γ, IL-10, IgG1, and IgG2a performed using ELISA as well as determining the parasite load after challenge with L. major in vaccinated mice. The results revealed that IFN-γ, IL-10, IgG1, and IgG2a significantly increased after vaccination using KMP11-HASPB-expressing lentiviruses in BALB/c mice. It is noteworthy that the level of IFN-γ and IgG2a was higher than that of IL-10 and IgG1, respectively, which indicates the activation Th1 cells, macrophages, and cellular immunity. Moreover, the parasite load in the spleen and lymph node of vaccinated mice after challenge was significantly lower than that of controls.

Acid-degradable polyurethane particles for protein-based vaccines

PubMed Central

Bachelder, Eric M.; Beaudette, Tristan T.; Broaders, Kyle E.; Paramonov, Sergey E.; Dashe, Jesse; Fréchet, Jean M. J.

2009-01-01

Acid-degradable particles containing a model protein antigen, ovalbumin, were prepared from a polyurethane with acetal moieties embedded throughout the polymer, and characterized by dynamic light scattering and transmission electron microscopy. The small molecule degradation by-product of the particles was synthesized and tested in vitro for toxicity indicating an LC50 of 12,500 μg/ml. A new liquid chromatography-mass spectrometry technique was developed to monitor the in vitro degradation of these particles. The degradation by-product inside RAW macrophages was at its highest level after 24 hours of culture and was efficiently exocytosed until it was no longer detectable after four days. When tested in vitro, these particles induced a substantial increase in the presentation of the immunodominant ovalbumin-derived peptide SIINFEKL in both macrophages and dendritic cells. In addition, vaccination with these particles generated a cytotoxic T-lymphocyte response that was superior to both free ovalbumin and particles made from an analogous but slower-degrading acid-labile polyurethane polymer. Overall, we present a fully degradable polymer system with non-toxic by-products, which may find use in various biomedical applications including protein-based vaccines. PMID:18710254

Comparative assessment of a DNA and protein Leishmania donovani gamma glutamyl cysteine synthetase vaccine to cross-protect against murine cutaneous leishmaniasis caused by L. major or L. mexicana infection.

PubMed

Campbell, S A; Alawa, J; Doro, B; Henriquez, F L; Roberts, C W; Nok, A; Alawa, C B I; Alsaadi, M; Mullen, A B; Carter, K C

2012-02-08

Leishmaniasis is a major health problem and it is estimated that 12 million people are currently infected. A vaccine which could cross-protect people against different Leishmania spp. would facilitate control of this disease as more than one species of Leishmania may be present. In this study the ability of a DNA vaccine, using the full gene sequence for L. donovani gamma glutamyl cysteine synthetase (γGCS) incorporated in the pVAX vector (pVAXγGCS), and a protein vaccine, using the corresponding recombinant L. donovani γGCS protein (LdγGCS), to protect against L. major or L. mexicana infection was evaluated. DNA vaccination gave transient protection against L. major and no protection against L. mexicana despite significantly enhancing specific antibody titres in vaccinated infected mice compared to infected controls. Vaccination with the LdγGCS protected against both species but only if the protein was incorporated into non-ionic surfactant vesicles for L. mexicana. The results of this study indicate that a L. donovani γGCS vaccine could be used to vaccinate against more than one Leishmania species but only if the recombinant protein is used. Copyright © 2012 Elsevier Ltd. All rights reserved.

Vaccination with Recombinant Non-transmembrane Domain of Protein Mannosyltransferase 4 Improves Survival during Murine Disseminated Candidiasis.

PubMed

Wang, Li; Yan, Lan; Li, Xing Xing; Xu, Guo Tong; An, Mao Mao; Jiang, Yuan Ying

2015-01-01

Candida albicans is the most common cause of invasive fungal infections in humans. The C. albicans cell wall proteins play an important role in crucial host-fungus interactions and might be ideal vaccine targets to induce protective immune response in host. Meanwhile, protein that is specific to C. albicans is also an ideal target of vaccine. In this study, 11 proteins involving cell wall biosynthesis, yeast-to-hypha formation, or specific to C. albicans were chosen and were successfully cloned, purified and verified. The immune protection of vaccination with each recombinant protein respectively in preventing systemic candidiasis in BALB/c mice was assessed. The injection of rPmt4p vaccination significantly increased survival rate, decreased fungal burdens in the heart, liver, brain, and kidneys, and increased serum levels of both immunoglobulin G (IgG) and IgM against rPmt4p in the immunized mice. Histopathological assessment demonstrated that rPmt4p vaccination protected the tissue structure, and decreased the infiltration of inflammatory cells. Passive transfer of the rPmt4p immunized serum increased survival rate against murine systemic candidiasis and significantly reduced organ fungal burden. The immune serum enhanced mouse neutrophil killing activity by directly neutralizing rPmt4p effects in vitro. Levels of interleukin (IL)-4, IL-10, IL-12p70, IL-17A and tumor necrosis factor (TNF)-α in serum were higher in the immunized mice compared to those in the adjuvant control group. In conclusion, our results suggested that rPmt4p vaccination may be considered as a potential vaccine candidate against systemic candidiasis.

Application of recombinant hemagglutinin proteins as alternative antigen standards for pandemic influenza vaccines.

PubMed

Choi, Yejin; Kwon, Seong Yi; Oh, Ho Jung; Shim, Sunbo; Chang, Seokkee; Chung, Hye Joo; Kim, Do Keun; Park, Younsang; Lee, Younghee

2017-09-01

The single radial immunodiffusion (SRID) assay, used to quantify hemagglutinin (HA) in influenza vaccines, requires reference reagents; however, because centralized production of reference reagents may slow the emergency deployment of vaccines, alternatives are needed. We investigated the production of HA proteins using recombinant DNA technology, rather than a traditional egg-based production process. The HA proteins were then used in an SRID assay as a reference antigen. We found that HA can be quantified in both egg-based and cell-based influenza vaccines when recombinant HAs (rHAs) are used as the reference antigen. Furthermore, we confirmed that rHAs obtained from strains with pandemic potential, such as H5N1, H7N3, H7N9, and H9N2 strains, can be utilized in the SRID assay. The rHA production process takes just one month, in contrast to the traditional process that takes three to four months. The use of rHAs may reduce the time required to produce reference reagents and facilitate timely introduction of vaccines during emergencies.

Protective immunity induced by an intranasal multivalent vaccine comprising 10 Lactococcus lactis strains expressing highly prevalent M-protein antigens derived from Group A Streptococcus.

PubMed

Wozniak, Aniela; Scioscia, Natalia; García, Patricia C; Dale, James B; Paillavil, Braulio A; Legarraga, Paulette; Salazar-Echegarai, Francisco J; Bueno, Susan M; Kalergis, Alexis M

2018-04-28

Streptococcus pyogenes (group A Streptococcus) causes diseases ranging from mild pharyngitis to severe invasive infections. The N-terminal fragment of Streptococcal M protein elicits protective antibodies and is an attractive vaccine target. However, this N- terminal fragment is hypervariable and there are more than 200 different M types. We are developing an intranasal live bacterial vaccine comprised of 10 strains of Lactococcus lactis, each expressing one N-terminal fagment of M protein. Live bacterial-vectored vaccines have lower associated costs because of its less complex manufacturing processes compared to protein subunit vaccines. Moreover, intranasal administration does not require syringe or specilized personnel. The evaluation of individual vaccine types (M1, M2, M3, M4, M6, M9, M12, M22, M28 and M77) showed that most of them protected mice against challenge with virulent S. pyogenes. All of the 10 strains combined in a 10-valent vaccine (Mx10) induced serum and bronchoalveolar lavages IgG titers that ranged from 3 to 10-fold those of unimmunized mice. Survival of Mx10-immunized mice after intranasal challenge with M28 streptococci is significantly higher than unimmunized mice. In contrast, when mice were challenged with M75 streptococci, survival of Mx10-immunized mice was not significantly different from unimmunized mice. Mx-10 immunized mice were significantly less colonized with S. pyogenes in oropharyngeal washes and developed less severe disease symptoms after challenge compared to unimmunized mice. Our L. lactis-based vaccine may provide an alternative solution to the development of broadly protective group A streptococcal vaccines. © 2018 The Societies and John Wiley & Sons Australia, Ltd.

Immunogenicity and safety of a respiratory syncytial virus fusion protein (RSV F) nanoparticle vaccine in older adults.

PubMed

Fries, Louis; Shinde, Vivek; Stoddard, Jeffrey J; Thomas, D Nigel; Kpamegan, Eloi; Lu, Hanxin; Smith, Gale; Hickman, Somia P; Piedra, Pedro; Glenn, Gregory M

2017-01-01

A preventative strategy for Respiratory Syncytial Virus (RSV) infection constitutes an under-recognized unmet medical need among older adults. Four formulations of a novel recombinant RSV F nanoparticle vaccine (60 or 90 μg RSV F protein, with or without aluminum phosphate adjuvant) administered concurrently with a licensed inactivated trivalent influenza vaccine (TIV) in older adult subjects were evaluated for safety and immunogenicity in this randomized, observer-blinded study. A total of 220 healthy males and females ≥ 60 years of age, without symptomatic cardiopulmonary disease, were vaccinated concurrently with TIV and RSV F vaccine or placebo. All vaccine formulations produced an acceptable safety profile, with no vaccine-related serious adverse events or evidence of systemic toxicity. Vaccine-induced immune responses were rapid, rising as early as 7 days post-vaccination; and were comparable in all formulations in terms of magnitude, with maximal levels attained within 28 (unadjuvanted) or 56 (adjuvanted) days post-vaccination. Peak anti-F protein IgG antibody levels rose 3.6- to 5.6-fold, with an adjuvant effect observed at the 60 μg dose, and a dose-effect observed between the unadjuvanted 60 and 90 μg regimens. The anti-F response persisted through 12 months post-vaccination. Palivizumab-competitive antibodies were below quantifiable levels (<33 μg/mL) at day 0. The rise of antibodies with specificity for Site II peptide, and the palivizumab-competitive binding activity, denoting antibodies binding at, or in proximity to, antigenic Site II on the F protein, closely paralleled the anti-F response. However, a larger proportion of antibodies in adjuvanted vaccine recipients bound to the Site II peptide at high avidity. Day 0 neutralizing antibodies were high in all subjects and rose 1.3- to 1.7-fold in response to vaccination. Importantly, the RSV F vaccine co-administered with TIV did not impact the serum hemagglutination inhibition

Identification of immunogenic proteins and evaluation of four recombinant proteins as potential vaccine antigens from Vibrio anguillarum in flounder (Paralichthys olivaceus).

PubMed

Xing, Jing; Xu, Hongsen; Wang, Yang; Tang, Xiaoqian; Sheng, Xiuzhen; Zhan, Wenbin

2017-05-31

Vibrio anguillarum is a severe bacterial pathogen that can infect a wide range of fish species. Identification of immunogenic proteins and development of vaccine are essential for disease prevention. In this study, immunogenic proteins were screened and identified from V. anguillarum, and then protective efficacy of the immunogenic proteins was evaluated. Immunogenic proteins in V. anguillarum whole cell were detected by Western blotting (WB) using immunized flounder (Paralichthys olivaceus) serum, and then identified by Mass spectrometry (MS). The recombinant proteins of four identified immunogenic proteins were produced and immunized to fish, and then percentages of surface membrane immunoglobulin-positive (sIg+) cells in peripheral blood lymphocytes (PBL), total antibodies, antibodies against V. anguillarum, antibodies against recombinant proteins and relative percent survival (RPS) were measured, respectively. The results showed that five immunogenic proteins, VAA, Groel, OmpU, PteF and SpK, were identified; their recombinant proteins, rOmpU, rGroel, rSpK and rVAA, could induce the proliferation of sIg+ cells in PBL and production of total antibodies, antibodies against V. anguillarum and antibodies against the recombinant proteins; their protection against V. anguillarum showed 64.86%, 72.97%, 21.62% and 78.38% RPS, respectively. The results revealed that the immunoproteomic technique using fish anti-V. anguillarum serum provided an efficient way to screen the immunogenic protein for vaccine antigen. Moreover, the rVAA, rGroel and rOmpU had potential to be vaccine candidates against V. anguillarum infection. Copyright © 2017 Elsevier Ltd. All rights reserved.

Herd Immunity Against Foot-and-Mouth Disease Under Different Vaccination Practices in India.

PubMed

Sharma, G K; Mahajan, S; Matura, R; Biswal, J K; Ranjan, R; Subramaniam, S; Misri, J; Bambal, R G; Pattnaik, B

2017-08-01

A systematic vaccination programme is ongoing in India to control the three prevailing serotypes (A, O, Asia1) of foot-and-mouth disease (FMD) virus. Under the programme, more than 120 million bovine (term bovine applicable to both cattle and buffalo in this study) population of 221 of the 666 districts in the country are being bi-annually vaccinated with trivalent vaccine since 2010. Although clinical disease has reduced in these districts because of the systematic vaccinations, an abrupt increase in the number of FMD cases was recorded in 2013. Hence, a longitudinal field study was conducted in the year 2014 to estimate the serological herd immunity level in bovines, the impact of systematic vaccinations and field efficacy of the vaccines used. Serum samples (n = 115 963) collected from 295 districts of the 18 states of the country were analysed to estimate antibody titres against structural proteins of the three serotypes. The efficacy of the vaccine was demonstrated in the control group (group-D) where animals of the group were identified by ear tags for the purpose of repeated sampling after vaccination. Progressive building of the herd immunity in the field after systematic vaccination was demonstrated. The mean antibody titre against the serotypes O, A and Asia1 was estimated as log 10 1.93 (95% CI 1.92-1.93), 2.02 (2.02-2.02) and 2.02 (2.02-2.02), respectively, in the states covered under the control programme. However, in other states herd immunity was significantly low [mean titre log 10 1.68 (95% CI 1.67-1.69), 1.77 (1.76-1.78) and 1.85 (1.84-1.86) against the three serotypes]. Inverse relationship between the herd immunity and FMD incidences was observed the states following different vaccination practices. The study helped in demarcation of FMD risk zones in the country with low herd immunity. Estimation of herd immunity kinetics in the field helped in refining the vaccination schedule under the control programme. © 2016 Blackwell Verlag GmbH.

Evaluation of the protective immunogencity of the N, P, M, NV and G proteins of infectious hematopoietic necrosis virus in rainbow trout Oncorhynchus mykiss using DNA vaccines

USGS Publications Warehouse

Corbeil, S.; LaPatra, S.E.; Anderson, E.D.; Jones, J.; Vincent, B.; Hsu, Ya Li; Kurath, G.

1999-01-01

The protective immunogenicity of the nucleoprotein (N), phosphoprotein (P), matrix protein (M), non-virion protein (NV) and glycoprotein (G) of the rhabdovirus infectious hematopoietic necrosis virus (IHNV) was assessed in rainbow trout using DNA vaccine technology. DNA vaccines were produced by amplifying and cloning the viral genes in the plasmid pCDNA 3.1. The protective immunity elicited by each vaccine was evaluated through survival of immunized fry after challenge with live virus. Neutralizing antibody titers were also determined in vaccinated rainbow troutOncorhynchus mykiss fry (mean weight 2 g) and 150 g sockeye salmon Oncorhynchus nerka. The serum from the 150 g fish was also used in passive immunization studies with naïve fry. Our results showed that neither the internal structural proteins (N, P and M) nor the NV protein of IHNV induced protective immunity in fry or neutralizing antibodies in fry and 150 g fish when expressed by a DNA vaccine construct. The G protein, however, did confer significant protection in fry up to 80 d post-immunization and induced protective neutralizing antibodies. We are currently investigating the role of different arms of the fish immune system that contribute to the high level of protection against IHNV seen in vaccinated fish.

Protein and modified vaccinia virus Ankara-based influenza virus nucleoprotein vaccines are differentially immunogenic in BALB/c mice.

PubMed

Altenburg, A F; Magnusson, S E; Bosman, F; Stertman, L; de Vries, R D; Rimmelzwaan, G F

2017-10-01

Because of the high variability of seasonal influenza viruses and the eminent threat of influenza viruses with pandemic potential, there is great interest in the development of vaccines that induce broadly protective immunity. Most probably, broadly protective influenza vaccines are based on conserved proteins, such as nucleoprotein (NP). NP is a vaccine target of interest as it has been shown to induce cross-reactive antibody and T cell responses. Here we tested and compared various NP-based vaccine preparations for their capacity to induce humoral and cellular immune responses to influenza virus NP. The immunogenicity of protein-based vaccine preparations with Matrix-M™ adjuvant as well as recombinant viral vaccine vector modified Vaccinia virus Ankara (MVA) expressing the influenza virus NP gene, with or without modifications that aim at optimization of CD8 + T cell responses, was addressed in BALB/c mice. Addition of Matrix-M™ adjuvant to NP wild-type protein-based vaccines significantly improved T cell responses. Furthermore, recombinant MVA expressing the influenza virus NP induced strong antibody and CD8 + T cell responses, which could not be improved further by modifications of NP to increase antigen processing and presentation. © 2017 British Society for Immunology.

Preclinical Vaccine Study of Plasmodium vivax Circumsporozoite Protein Derived-Synthetic Polypeptides Formulated in Montanide ISA 720 and Montanide ISA 51 Adjuvants

PubMed Central

Arévalo-Herrera, Myriam; Vera, Omaira; Castellanos, Angélica; Céspedes, Nora; Soto, Liliana; Corradin, Giampietro; Herrera, Sócrates

2011-01-01

Plasmodium vivax circumsporozoite (CS) protein is a leading malaria vaccine candidate previously assessed in animals and humans. Here, combinations of three synthetic polypeptides corresponding to amino (N), central repeat (R), and carboxyl (C) regions of the CS protein formulated in Montanide ISA 720 or Montanide ISA 51 adjuvants were assessed for immunogenicity in rodents and primates. BALB/c mice and Aotus monkeys were divided into test and control groups and were immunized three times with doses of 50 and 100 μg of vaccine or placebo. Antigen-specific antimalarial antibodies were determined by enzyme-linked immunosorbent assay, immunofluorescent antibody test, and IFN-γ responses by enzyme-linked immunosorbent spot (ELIspot). Both vaccine formulations were highly immunogenic in both species. Mice developed better antibody responses against C and R polypeptides, whereas the N polypeptide was more immunogenic in monkeys. Anti-peptide antibodies remained detectable for several months and recognized native proteins on sporozoites. Differences between Montanide ISA 720 and Montanide ISA 51 formulations were not significant. PMID:21292874

Vaccination of calves using the BRSV nucleocapsid protein in a DNA prime-protein boost strategy stimulates cell-mediated immunity and protects the lungs against BRSV replication and pathology.

PubMed

Letellier, Carine; Boxus, Mathieu; Rosar, Laurent; Toussaint, Jean-François; Walravens, Karl; Roels, Stefan; Meyer, Gilles; Letesson, Jean-Jacques; Kerkhofs, Pierre

2008-09-02

Respiratory syncytial virus (RSV) is a major cause of respiratory disease in both cattle and young children. Despite the development of vaccines against bovine (B)RSV, incomplete protection and exacerbation of subsequent RSV disease have occurred. In order to circumvent these problems, calves were vaccinated with the nucleocapsid protein, known to be a major target of CD8(+) T cells in cattle. This was performed according to a DNA prime-protein boost strategy. The results showed that DNA vaccination primed a specific T-cell-mediated response, as indicated by both a lymphoproliferative response and IFN-gamma production. These responses were enhanced after protein boost. After challenge, mock-vaccinated calves displayed gross pneumonic lesions and viral replication in the lungs. In contrast, calves vaccinated by successive administrations of plasmid DNA and protein exhibited protection against the development of pneumonic lesions and the viral replication in the BAL fluids and the lungs. The protection correlated to the cell-mediated immunity and not to the antibody response.

Respiratory syncytial virus subunit vaccine based on a recombinant fusion protein expressed transiently in mammalian cells.

PubMed

Nallet, Sophie; Amacker, Mario; Westerfeld, Nicole; Baldi, Lucia; König, Iwo; Hacker, David L; Zaborosch, Christiane; Zurbriggen, Rinaldo; Wurm, Florian M

2009-10-30

Although respiratory syncytial virus (RSV) causes severe lower respiratory tract infection in infants and adults at risk, no RSV vaccine is currently available. In this report, efforts toward the generation of an RSV subunit vaccine using recombinant RSV fusion protein (rRSV-F) are described. The recombinant protein was produced by transient gene expression (TGE) in suspension-adapted human embryonic kidney cells (HEK-293E) in 4 L orbitally shaken bioreactors. It was then purified and formulated in immunostimulating reconstituted influenza virosomes (IRIVs). The candidate vaccine induced anti-RSV-F neutralizing antibodies in mice, and challenge studies in cotton rats are ongoing. If successful in preclinical and clinical trials, this will be the first recombinant subunit vaccine produced by large-scale TGE in mammalian cells.

Physician communication about adolescent vaccination: How is human papillomavirus vaccine different?

PubMed

Gilkey, Melissa B; Moss, Jennifer L; Coyne-Beasley, Tamera; Hall, Megan E; Shah, Parth D; Brewer, Noel T

2015-08-01

Low human papillomavirus (HPV) vaccination coverage stands in stark contrast to our success in delivering other adolescent vaccines. To identify opportunities for improving physicians' recommendations for HPV vaccination, we sought to understand how the communication context surrounding adolescent vaccination varies by vaccine type. A national sample of 776 U.S. physicians (53% pediatricians, 47% family medicine physicians) completed our online survey in 2014. We assessed physicians' perceptions and communication practices related to recommending adolescent vaccines for 11- and 12-year-old patients. About three-quarters of physicians (73%) reported recommending HPV vaccine as highly important for patients, ages 11-12. More physicians recommended tetanus, diphtheria, and acellular pertussis (Tdap) (95%) and meningococcal vaccines (87%, both p<0.001) as highly important for this age group. Only 13% of physicians perceived HPV vaccine as being highly important to parents, which was far fewer than perceived parental support for Tdap (74%) and meningococcal vaccines (62%, both p<0.001). Physicians reported that discussing HPV vaccine took almost twice as long as discussing Tdap. Among physicians with a preferred order for discussing adolescent vaccines, most (70%) discussed HPV vaccine last. Our findings suggest that primary care physicians perceived HPV vaccine discussions to be burdensome, requiring more time and engendering less parental support than other adolescent vaccines. Perhaps for this reason, physicians in our national study recommended HPV vaccine less strongly than other adolescent vaccines, and often chose to discuss it last. Communication strategies are needed to support physicians in recommending HPV vaccine with greater confidence and efficiency. Copyright © 2015 Elsevier Inc. All rights reserved.

Enhanced immunogenicity of HPV 16 E7 fusion proteins in DNA vaccination.

PubMed

Michel, Nico; Osen, Wolfram; Gissmann, Lutz; Schumacher, Ton N M; Zentgraf, Hanswalter; Müller, Martin

2002-03-01

DNA vaccination is a promising approach for inducing both humoral and cellular immune responses. For immunotherapy of HPV-16-associated diseases the E7 protein is considered a prime candidate, as it is expressed in all HPV-16-positive tumors. Unfortunately, the E7 protein is a very poor inducer of a cytotoxic T-cell response, when being used as antigen in DNA vaccination. Here we demonstrate that after fusion to protein export/import signals such as the herpes simplex virus ferry protein VP22, E7 can translocate in vitro from VP22-E7-expressing cells to neighboring cells that do not carry the VP22-E7 gene. In vivo, the VP22-E7 fusion shows significantly increased efficiency in inducing a cytotoxic T-cell response. Our data suggest that the export function of VP22 plays a major role in this phenomenon, since VP22 can be replaced by classical protein export signals, without impairing the induction of the E7-specific cellular immune response. However, all E7 fusion constructs showed significantly elevated protein steady-state levels, which might also account for the observed boost in immunogenicity. (C)2002 Elsevier Science (USA).

Kicking against the pricks: vaccine sceptics have a different social orientation.

PubMed

Luyten, Jeroen; Desmet, Pieter; Dorgali, Veronica; Hens, Niel; Beutels, Philippe

2014-04-01

In any country, part of the population is sceptical about the utility of vaccination. To develop successful vaccination programmes, it is important to study and understand the defining characteristics of vaccine sceptics. Research till now mainly focused either on the underlying motives of vaccine refusal, or on socio-demographic differences between vaccine sceptics and non-sceptics. It remained till now unexplored whether both groups differ in terms of basic psychological dispositions. We held a population survey in a representative sample of the population in Flanders, Belgium (N = 1050), in which we investigated whether respondents' attitude to vaccination was associated with their basic disposition toward other community members or society in general, as measured by the Triandis and Gelfand social orientation scale. We found that sceptics and non-sceptics have a different social orientation, even when several variables are controlled for. More specifically, vaccine sceptics scored significantly lower on both horizontal individualism and horizontal collectivism, indicating a lower disposition to see others as equals. These findings need confirmation in the context of different countries. Such insights can be valuable to optimize the design of effective communication strategies on vaccination programmes.

Vaccinating Girls and Boys with Different Human Papillomavirus Vaccines: Can It Optimise Population-Level Effectiveness?

PubMed

Drolet, Mélanie; Boily, Marie-Claude; Van de Velde, Nicolas; Franco, Eduardo L; Brisson, Marc

2013-01-01

Decision-makers may consider vaccinating girls and boys with different HPV vaccines to benefit from their respective strengths; the quadrivalent (HPV4) prevents anogenital warts (AGW) whilst the bivalent (HPV2) may confer greater cross-protection. We compared, to a girls-only vaccination program with HPV4, the impact of vaccinating: 1) both genders with HPV4, and 2) boys with HPV4 and girls with HPV2. We used an individual-based transmission-dynamic model of heterosexual HPV infection and diseases. Our base-case scenario assumed lifelong efficacy of 100% against vaccine types, and 46,29,8,18,6% and 77,43,79,8,0% efficacy against HPV-31,-33,-45,-52,-58 for HPV4 and HPV2, respectively. Assuming 70% vaccination coverage and lifelong cross-protection, vaccinating boys has little additional benefit on AGW prevention, irrespective of the vaccine used for girls. Furthermore, using HPV4 for boys and HPV2 for girls produces greater incremental reductions in SCC incidence than using HPV4 for both genders (12 vs 7 percentage points). At 50% vaccination coverage, vaccinating boys produces incremental reductions in AGW of 17 percentage points if both genders are vaccinated with HPV4, but increases female incidence by 16 percentage points if girls are switched to HPV2 (heterosexual male incidence is incrementally reduced by 24 percentage points in both scenarios). Higher incremental reductions in SCC incidence are predicted when vaccinating boys with HPV4 and girls with HPV2 versus vaccinating both genders with HPV4 (16 vs 12 percentage points). Results are sensitive to vaccination coverage and the relative duration of protection of the vaccines. Vaccinating girls with HPV2 and boys with HPV4 can optimize SCC prevention if HPV2 has higher/longer cross-protection, but can increase AGW incidence if vaccination coverage is low among boys.

Correlates of Protection for M Protein-Based Vaccines against Group A Streptococcus

PubMed Central

Smeesters, Pierre R.; Frost, Hannah R. C.; Steer, Andrew C.

2015-01-01

Group A streptococcus (GAS) is known to cause a broad spectrum of illness, from pharyngitis and impetigo, to autoimmune sequelae such as rheumatic heart disease, and invasive diseases. It is a significant cause of infectious disease morbidity and mortality worldwide, but no efficacious vaccine is currently available. Progress in GAS vaccine development has been hindered by a number of obstacles, including a lack of standardization in immunoassays and the need to define human correlates of protection. In this review, we have examined the current immunoassays used in both GAS and other organisms, and explored the various challenges in their implementation in order to propose potential future directions to identify a correlate of protection and facilitate the development of M protein-based vaccines, which are currently the main GAS vaccine candidates. PMID:26101780

Anti-Group B Streptococcus Glycan-Conjugate Vaccines Using Pilus Protein GBS80 As Carrier and Antigen: Comparing Lysine and Tyrosine-directed Conjugation.

PubMed

Nilo, Alberto; Morelli, Laura; Passalacqua, Irene; Brogioni, Barbara; Allan, Martin; Carboni, Filippo; Pezzicoli, Alfredo; Zerbini, Francesca; Maione, Domenico; Fabbrini, Monica; Romano, Maria Rosaria; Hu, Qi-Ying; Margarit, Immaculada; Berti, Francesco; Adamo, Roberto

2015-07-17

Gram-positive Streptococcus agalactiae or group B Streptococcus (GBS) is a leading cause of invasive infections in pregnant women, newborns, and elderly people. Vaccination of pregnant women represents the best strategy for prevention of neonatal disease, and GBS polysaccharide-based conjugate vaccines are currently under clinical testing. The potential of GBS pilus proteins selected by genome-based reverse vaccinology as protective antigens for anti-streptococcal vaccines has also been demonstrated. Dressing pilus proteins with surface glycan antigens could be an attractive approach to extend vaccine coverage. We have recently developed an efficient method for tyrosine-directed ligation of large glycans to proteins via copper-free azide-alkyne [3 + 2] cycloaddition. This method enables targeting of predetermined sites of the protein, ensuring that protein epitopes are preserved prior to glycan coupling and a higher consistency in glycoconjugate batches. Herein, we compared conjugates of the GBS type II polysaccharide (PSII) and the GBS80 pilus protein obtained by classic lysine random conjugation and by the recently developed tyrosine-directed ligation. PSII conjugated to CRM197, a carrier protein used for vaccines in the market, was used as a control. We found that the constructs made from PSII and GBS80 were able to elicit murine antibodies recognizing individually the glycan and protein epitopes on the bacterial surface. The generated antibodies were efficacious in mediating opsonophagocytic killing of strains expressing exclusively PSII or GBS80 proteins. The two glycoconjugates were also effective in protecting newborn mice against GBS infection following vaccination of the dams. Altogether, these results demonstrated that polysaccharide-conjugated GBS80 pilus protein functions as a carrier comparably to CRM197, while maintaining its properties of protective protein antigen. Glycoconjugation and reverse vaccinology can, therefore, be combined to design

Immunogenicity and protective efficacy of Semliki forest virus replicon-based DNA vaccines encoding goatpox virus structural proteins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng Min; Guangxi Center for Animal Disease Control and Prevention, Nanning 530001; College of Animal Science and Veterinary Medicine, Jilin University, Changchun 130062

Goatpox, caused by goatpox virus (GTPV), is an acute feverish and contagious disease in goats often associated with high morbidity and high mortality. To resolve potential safety risks and vaccination side effects of existing live attenuated goatpox vaccine (AV41), two Semliki forest virus (SFV) replicon-based bicistronic expression DNA vaccines (pCSm-AAL and pCSm-BAA) which encode GTPV structural proteins corresponding to the Vaccinia virus proteins A27, L1, A33, and B5, respectively, were constructed. Then, theirs ability to induce humoral and cellular response in mice and goats, and protect goats against virulent virus challenge were evaluated. The results showed that, vaccination with pCSm-AALmore » and pCSm-BAA in combination could elicit strong humoral and cellular responses in mice and goats, provide partial protection against viral challenge in goats, and reduce disease symptoms. Additionally, priming vaccination with the above-mentioned DNA vaccines could significantly reduce the goats' side reactions from boosting vaccinations with current live vaccine (AV41), which include skin lesions at the inoculation site and fevers. Data obtained in this study could not only facilitate improvement of the current goatpox vaccination strategy, but also provide valuable guidance to suitable candidates for evaluation and development of orthopoxvirus vaccines.« less

[Effectiveness of rapid hepatitis B vaccination with different vaccine dosages and types in adults].

PubMed

Nie, L; Pang, X H; Zhang, Z; Ma, J X; Liu, X Y; Qiu, Q; Liang, Y; Li, Q; Zhang, W

2017-09-10

Objective: To evaluate the effectiveness of rapid hepatitis B vaccination with different vaccine dosages and types in adults. Methods: Adults who were aged ≥20 years, negative in the detections of 5 HBV serum markers or only anti-HBc positive were selected from Chaoyang district of Beijing. They were divided into 4 community-based specific groups and given three doses of 10 μg HepB-SCY vaccine, 20 μg HepB-SCY vaccine, 20 μg HepB-CHO vaccine and 10 μg HepB-HPY vaccine respectively at month 0, 1, and 2. Their blood samples were collected within 1-2 months after completing the three dose vaccination to test anti-HBs level by using chemiluminesent microparticle immunoassay. A face to face questionnaire survey was conducted, and χ (2) test, Mantel- Haensel χ (2) test, Kruskal-Wallis rank test and multiple logistic regression analysis were performed. Results: A total of 1 772 participants completed vaccination and observation. Their average age was 48.5 years, and 62.75 % of them were females. The anti-HBs positive rates in the groups of 10 μg HepB-SCY, 20 μg HepB-SCY, 20 μg HepB-CHO and 10 μg HepB-HPY vaccines were 79.49 % , 84.34 % , 82.50 % and 74.15 %, respectively ( P =0.005), and the geometric mean titers (GMT) were39.53 mIU/ml, 62.37 mIU/ml, 48.18 mIU/ml and 33.64 mIU/ml respectively ( P =0.025). The overall anti-HBs positive rate and GMT were 79.01 % and 41.18 mIU/ml. The anti-HBs GMT of 4 groups declined with age. The differences in anti-HBs GMT among 4 groups minimized with age. The result of logistic modeling indicated that vaccine type and dosage, age and smoking were associated with anti-HBs statistically after controlling the variables of"only anti-HBc positive or not"and"history of hepatitis B vaccination". Conclusion: Hepatitis B vaccination at dosage of 20 μg based on 0-1-2 month rapid schedule could achieved anti-HBs positive rates>80 % in middle aged and old people, which can be used as supplement of 0-1-6 month routine schedule.

Nanoparticle Vaccines Encompassing the Respiratory Syncytial Virus (RSV) G Protein CX3C Chemokine Motif Induce Robust Immunity Protecting from Challenge and Disease

PubMed Central

Jorquera, Patricia A.; Choi, Youngjoo; Oakley, Katie E.; Powell, Thomas J.; Boyd, James G.; Palath, Naveen; Haynes, Lia M.; Anderson, Larry J.; Tripp, Ralph A.

2013-01-01

Nanoparticle vaccines were produced using layer-by-layer fabrication and incorporating respiratory syncytial virus (RSV) G protein polypeptides comprising the CX3C chemokine motif. BALB/c mice immunized with G protein nanoparticle vaccines produced a neutralizing antibody response that inhibited RSV replication in the lungs following RSV challenge. ELISPOT analysis showed that G nanoparticle vaccinated mice had increased levels of RSV G protein-specific IL-4 and IFN-γ secreting cells compared to controls following RSV challenge. Remarkably, RSV challenge of G protein nanoparticle vaccinated mice resulted in increased RSV M2-specific IL-4 and IFN-γ secreting T cells, and increased M2-specific H-2Kd-tetramer positive CD8+ T cells in the lungs compared to controls. Cell type analysis showed vaccination was not associated with increased pulmonary eosinophilia following RSV challenge. These results demonstrate that vaccination of mice with the RSV G protein nanoparticle vaccines induces a potent neutralizing antibody response, increased G protein- and M2- specific T cell responses, and a reduction in RSV disease pathogenesis. PMID:24040360

Genetic characterization of L-Zagreb mumps vaccine strain.

PubMed

Ivancic, Jelena; Gulija, Tanja Kosutic; Forcic, Dubravko; Baricevic, Marijana; Jug, Renata; Mesko-Prejac, Majda; Mazuran, Renata

2005-04-01

Eleven mumps vaccine strains, all containing live attenuated virus, have been used throughout the world. Although L-Zagreb mumps vaccine has been licensed since 1972, only its partial nucleotide sequence was previously determined (accession numbers , and ). Therefore, we sequenced the entire genome of L-Zagreb vaccine strain (Institute of Immunology Inc., Zagreb, Croatia). In order to investigate the genetic stability of the vaccine, sequences of both L-Zagreb master seed and currently produced vaccine batch were determined and no difference between them was observed. A phylogenetic analysis based on SH gene sequence has shown that L-Zagreb strain does not belong to any of established mumps genotypes and that it is most similar to old, laboratory preserved European strains (1950s-1970s). L-Zagreb nucleotide and deduced protein sequences were compared with other mumps virus sequences obtained from the GenBank. Emphasis was put on functionally important protein regions and known antigenic epitopes. The extensive comparisons of nucleotide and deduced protein sequences between L-Zagreb vaccine strain and other previously determined mumps virus sequences have shown that while the functional regions of HN, V, and L proteins are well conserved among various mumps strains, there can be a substantial amino acid difference in antigenic epitopes of all proteins and in functional regions of F protein. No molecular pattern was identified that can be used as a distinction marker between virulent and attenuated strains.

An Eimeria vaccine candidate based on Eimeria tenella immune mapped protein 1 and the TLR-5 agonist Salmonella typhimurium FliC flagellin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yin, Guangwen; Qin, Mei; Liu, Xianyong

Highlights: •We found a new protective protein – (IMPI) in Eimeria tenella. •EtIMP1-flagellin fusion protein is an effective immunogen against Eimeria infection. •Flagellin can be as an apicomplexan parasite vaccine adjuvant in chickens. -- Abstract: Immune mapped protein-1 (IMP1) is a new protective protein in apicomplexan parasites, and exits in Eimeria tenella. But its structure and immunogenicity in E. tenella are still unknown. In this study, IMPI in E. tenella was predicted to be a membrane protein. To evaluate immunogenicity of IMPI in E. tenella, a chimeric subunit vaccine consisting of E. tenella IMP1 (EtIMP1) and a molecular adjuvant (amore » truncated flagellin, FliC) was constructed and over-expressed in Escherichia coli and its efficacy against E. tenella infection was evaluated. Three-week-old AA broiler chickens were vaccinated with the recombinant EtIMP1-truncated FliC without adjuvant or EtIMP1 with Freund’s Complete Adjuvant. Immunization of chickens with the recombinant EtIMP1-truncated FliC fusion protein resulted in stronger cellular immune responses than immunization with only recombinant EtIMP1 with adjuvant. The clinical effect of the EtIMP1-truncated FliC without adjuvant was also greater than that of the EtIMP1 with adjuvant, which was evidenced by the differences between the two groups in body weight gain, oocyst output and caecal lesions of E. tenella-challenged chickens. The results suggested that the EtIMP1-flagellin fusion protein can be used as an effective immunogen in the development of subunit vaccines against Eimeria infection. This is the first demonstration of antigen-specific protective immunity against avian coccidiosis using a recombinant flagellin as an apicomplexan parasite vaccine adjuvant in chickens.« less

A Comparison of Red Fluorescent Proteins to Model DNA Vaccine Expression by Whole Animal In Vivo Imaging.

PubMed

Kinnear, Ekaterina; Caproni, Lisa J; Tregoning, John S

2015-01-01

DNA vaccines can be manufactured cheaply, easily and rapidly and have performed well in pre-clinical animal studies. However, clinical trials have so far been disappointing, failing to evoke a strong immune response, possibly due to poor antigen expression. To improve antigen expression, improved technology to monitor DNA vaccine transfection efficiency is required. In the current study, we compared plasmid encoded tdTomato, mCherry, Katushka, tdKatushka2 and luciferase as reporter proteins for whole animal in vivo imaging. The intramuscular, subcutaneous and tattooing routes were compared and electroporation was used to enhance expression. We observed that overall, fluorescent proteins were not a good tool to assess expression from DNA plasmids, with a highly heterogeneous response between animals. Of the proteins used, intramuscular delivery of DNA encoding either tdTomato or luciferase gave the clearest signal, with some Katushka and tdKatushka2 signal observed. Subcutaneous delivery was weakly visible and nothing was observed following DNA tattooing. DNA encoding haemagglutinin was used to determine whether immune responses mirrored visible expression levels. A protective immune response against H1N1 influenza was induced by all routes, even after a single dose of DNA, though qualitative differences were observed, with tattooing leading to high antibody responses and subcutaneous DNA leading to high CD8 responses. We conclude that of the reporter proteins used, expression from DNA plasmids can best be assessed using tdTomato or luciferase. But, the disconnect between visible expression level and immunogenicity suggests that in vivo whole animal imaging of fluorescent proteins has limited utility for predicting DNA vaccine efficacy.

Identification of proteins of Propionibacterium acnes for use as vaccine candidates to prevent infection by the pig pathogen Actinobacillus pleuropneumoniae.

PubMed

Li, Linxi; Sun, Changjiang; Yang, Feng; Yang, Shuxin; Feng, Xin; Gu, Jingmin; Han, Wenyu; Langford, Paul R; Lei, Liancheng

2013-10-25

Actinobacillus pleuropneumoniae is the causative agent of acute and chronic pleuroneumonia that is responsible for substantial morbidity and mortality in the pig industry. New improved vaccines that can protect against all serotypes and prevent colonization are required. In a previous study we showed that whole cells of Propionibacterium acnes protected pigs from A. pleuropneumoniae serotype 1 and 5 and, therefore, the basis for a promising heterologous vaccine. The aim of this study was to identify those protein antigens of P. acnes responsible for protection against A. pleuropneumoniae infection. Six P. acnes protein antigens that were recognized by sera raised against A. pleuropneumoniae were identified by 2-DE and immunoblotting. Recombinant versions of all P. acnes proteins gave partial protection (10-80%) against A. pleuropneumoniae serotype 1 and/or 5 infection in a mouse challenge model. The best protection (80% serotype 1; 60% serotype 5) was obtained using recombinant P. acnes single-stranded DNA-binding protein. In part, protection against A. pleuropneumoniae infection may be mediated by small peptide sequences present in P. acnes single-stranded DNA-binding protein that are cross-reactive with those present in the A. pleuropneumoniae-specific RTX toxin ApxIV and the zinc-binding protein ZnuA. The results suggest that P. acnes may be a useful vaccine to protect against different serotypes of A. pleuropneumoniae. Copyright © 2013 Elsevier Ltd. All rights reserved.

Immunization of a wild koala population with a recombinant Chlamydia pecorum Major Outer Membrane Protein (MOMP) or Polymorphic Membrane Protein (PMP) based vaccine: New insights into immune response, protection and clearance.

PubMed

Desclozeaux, Marion; Robbins, Amy; Jelocnik, Martina; Khan, Shahneaz Ali; Hanger, Jon; Gerdts, Volker; Potter, Andrew; Polkinghorne, Adam; Timms, Peter

2017-01-01

We assessed the effects of two different single-dose anti-Chlamydia pecorum (C. pecorum) vaccines (containing either Major Outer Membrane Protein (3MOMP) or Polymorphic Membrane Protein (Pmp) as antigens) on the immune response of a group of wild koalas. Both vaccines elicited a systemic humoral response as seen by the production of anti-chlamydial IgG antibodies in more than 90% of vaccinated koalas. A mucosal immune response was also observed, with an increase in Chlamydia-specific mucosal IgG and/or IgA antibodies in some koalas post-vaccination. Both vaccines elicited a cell-mediated immune response as measured by the production of the cytokines IFN-γ and IL-17 post-vaccination. To determine the level of protection provided by the vaccines under natural conditions we assessed C. pecorum infection loads and chlamydial disease status of all vaccinated koalas pre- and post-vaccination, compared to a non-vaccinated cohort from the same habitat. The MOMP vaccinated koalas that were infected on the day of vaccination showed significant clearance of their infection at 6 months post-vaccination. In contrast, the number of new infections in the PMP vaccine was similar to the control group, with some koalas progressing to disease. Genotyping of the ompA gene from the C. pecorum strains infecting the vaccinated animals, identified genetic variants of ompA-F genotype and a new genotype ompA-O. We found that those animals that were the least well protected became infected with strains of C. pecorum not covered by the vaccine. In conclusion, a single dose vaccine formulated with either recombinant PmpG or MOMP can elicit both cell-mediated and humoral (systemic and mucosal) immune responses, with the MOMP vaccine showing clearance of infection in all infected koalas. Although the capability of our vaccines to stimulate an adaptive response and be protective needs to be fully evaluated, this work illustrates the necessity to combine epitopes most relevant to a large panel of

Yeast-expressed recombinant protein of the receptor-binding domain in SARS-CoV spike protein with deglycosylated forms as a SARS vaccine candidate

PubMed Central

Chen, Wen-Hsiang; Du, Lanying; Chag, Shivali M; Ma, Cuiqing; Tricoche, Nancy; Tao, Xinrong; Seid, Christopher A; Hudspeth, Elissa M; Lustigman, Sara; Tseng, Chien-Te K; Bottazzi, Maria Elena; Hotez, Peter J; Zhan, Bin; Jiang, Shibo

2014-01-01

Development of vaccines for preventing a future pandemic of severe acute respiratory syndrome (SARS) caused by SARS coronavirus (SARS-CoV) and for biodefense preparedness is urgently needed. Our previous studies have shown that a candidate SARS vaccine antigen consisting of the receptor-binding domain (RBD) of SARS-CoV spike protein can induce potent neutralizing antibody responses and protection against SARS-CoV challenge in vaccinated animals. To optimize expression conditions for scale-up production of the RBD vaccine candidate, we hypothesized that this could be potentially achieved by removing glycosylation sites in the RBD protein. In this study, we constructed two RBD protein variants: 1) RBD193-WT (193-aa, residues 318–510) and its deglycosylated forms (RBD193-N1, RBD193-N2, RBD193-N3); 2) RBD219-WT (219-aa, residues 318–536) and its deglycosylated forms (RBD219-N1, RBD219-N2, and RBD219-N3). All constructs were expressed as recombinant proteins in yeast. The purified recombinant proteins of these constructs were compared for their antigenicity, functionality and immunogenicity in mice using alum as the adjuvant. We found that RBD219-N1 exhibited high expression yield, and maintained its antigenicity and functionality. More importantly, RBD219-N1 induced significantly stronger RBD-specific antibody responses and a higher level of neutralizing antibodies in immunized mice than RBD193-WT, RBD193-N1, RBD193-N3, or RBD219-WT. These results suggest that RBD219-N1 could be selected as an optimal SARS vaccine candidate for further development. PMID:24355931

Yeast-expressed recombinant protein of the receptor-binding domain in SARS-CoV spike protein with deglycosylated forms as a SARS vaccine candidate.

PubMed

Chen, Wen-Hsiang; Du, Lanying; Chag, Shivali M; Ma, Cuiqing; Tricoche, Nancy; Tao, Xinrong; Seid, Christopher A; Hudspeth, Elissa M; Lustigman, Sara; Tseng, Chien-Te K; Bottazzi, Maria Elena; Hotez, Peter J; Zhan, Bin; Jiang, Shibo

2014-01-01

Development of vaccines for preventing a future pandemic of severe acute respiratory syndrome (SARS) caused by SARS coronavirus (SARS-CoV) and for biodefense preparedness is urgently needed. Our previous studies have shown that a candidate SARS vaccine antigen consisting of the receptor-binding domain (RBD) of SARS-CoV spike protein can induce potent neutralizing antibody responses and protection against SARS-CoV challenge in vaccinated animals. To optimize expression conditions for scale-up production of the RBD vaccine candidate, we hypothesized that this could be potentially achieved by removing glycosylation sites in the RBD protein. In this study, we constructed two RBD protein variants: 1) RBD193-WT (193-aa, residues 318-510) and its deglycosylated forms (RBD193-N1, RBD193-N2, RBD193-N3); 2) RBD219-WT (219-aa, residues 318-536) and its deglycosylated forms (RBD219-N1, RBD219-N2, and RBD219-N3). All constructs were expressed as recombinant proteins in yeast. The purified recombinant proteins of these constructs were compared for their antigenicity, functionality and immunogenicity in mice using alum as the adjuvant. We found that RBD219-N1 exhibited high expression yield, and maintained its antigenicity and functionality. More importantly, RBD219-N1 induced significantly stronger RBD-specific antibody responses and a higher level of neutralizing antibodies in immunized mice than RBD193-WT, RBD193-N1, RBD193-N3, or RBD219-WT. These results suggest that RBD219-N1 could be selected as an optimal SARS vaccine candidate for further development.

Identification of Novel Pre-Erythrocytic Malaria Antigen Candidates for Combination Vaccines with Circumsporozoite Protein

PubMed Central

Sahu, Tejram; Malkov, Vlad; Morrison, Robert; Pei, Ying; Juompan, Laure; Milman, Neta; Zarling, Stasya; Anderson, Charles; Wong-Madden, Sharon; Wendler, Jason; Ishizuka, Andrew; MacMillen, Zachary W.; Garcia, Valentino; Kappe, Stefan H. I.; Krzych, Urszula; Duffy, Patrick E.

2016-01-01

Malaria vaccine development has been hampered by the limited availability of antigens identified through conventional discovery approaches, and improvements are needed to enhance the efficacy of the leading vaccine candidate RTS,S that targets the circumsporozoite protein (CSP) of the infective sporozoite. Here we report a transcriptome-based approach to identify novel pre-erythrocytic vaccine antigens that could potentially be used in combination with CSP. We hypothesized that stage-specific upregulated genes would enrich for protective vaccine targets, and used tiling microarray to identify P. falciparum genes transcribed at higher levels during liver stage versus sporozoite or blood stages of development. We prepared DNA vaccines for 21 genes using the predicted orthologues in P. yoelii and P. berghei and tested their efficacy using different delivery methods against pre-erythrocytic malaria in rodent models. In our primary screen using P. yoelii in BALB/c mice, we found that 16 antigens significantly reduced liver stage parasite burden. In our confirmatory screen using P. berghei in C57Bl/6 mice, we confirmed 6 antigens that were protective in both models. Two antigens, when combined with CSP, provided significantly greater protection than CSP alone in both models. Based on the observations reported here, transcriptional patterns of Plasmodium genes can be useful in identifying novel pre-erythrocytic antigens that induce protective immunity alone or in combination with CSP. PMID:27434123

Identification of Novel Pre-Erythrocytic Malaria Antigen Candidates for Combination Vaccines with Circumsporozoite Protein.

PubMed

Speake, Cate; Pichugin, Alexander; Sahu, Tejram; Malkov, Vlad; Morrison, Robert; Pei, Ying; Juompan, Laure; Milman, Neta; Zarling, Stasya; Anderson, Charles; Wong-Madden, Sharon; Wendler, Jason; Ishizuka, Andrew; MacMillen, Zachary W; Garcia, Valentino; Kappe, Stefan H I; Krzych, Urszula; Duffy, Patrick E

2016-01-01

Malaria vaccine development has been hampered by the limited availability of antigens identified through conventional discovery approaches, and improvements are needed to enhance the efficacy of the leading vaccine candidate RTS,S that targets the circumsporozoite protein (CSP) of the infective sporozoite. Here we report a transcriptome-based approach to identify novel pre-erythrocytic vaccine antigens that could potentially be used in combination with CSP. We hypothesized that stage-specific upregulated genes would enrich for protective vaccine targets, and used tiling microarray to identify P. falciparum genes transcribed at higher levels during liver stage versus sporozoite or blood stages of development. We prepared DNA vaccines for 21 genes using the predicted orthologues in P. yoelii and P. berghei and tested their efficacy using different delivery methods against pre-erythrocytic malaria in rodent models. In our primary screen using P. yoelii in BALB/c mice, we found that 16 antigens significantly reduced liver stage parasite burden. In our confirmatory screen using P. berghei in C57Bl/6 mice, we confirmed 6 antigens that were protective in both models. Two antigens, when combined with CSP, provided significantly greater protection than CSP alone in both models. Based on the observations reported here, transcriptional patterns of Plasmodium genes can be useful in identifying novel pre-erythrocytic antigens that induce protective immunity alone or in combination with CSP.

Expression of Plasmodium falciparum Circumsporozoite Proteins in Escherichia coli for Potential Use in a Human Malaria Vaccine

NASA Astrophysics Data System (ADS)

Young, James F.; Hockmeyer, Wayne T.; Gross, Mitchell; Ripley Ballou, W.; Wirtz, Robert A.; Trosper, James H.; Beaudoin, Richard L.; Hollingdale, Michael R.; Miller, Louis H.; Diggs, Carter L.; Rosenberg, Martin

1985-05-01

The circumsporozoite (CS) protein of the human malaria parasite Plasmodium falciparum may be the most promising target for the development of a malaria vaccine. In this study, proteins composed of 16, 32, or 48 tandem copies of a tetrapeptide repeating sequence found in the CS protein were efficiently expressed in the bacterium Escherichia coli. When injected into mice, these recombinant products resulted in the production of high titers of antibodies that reacted with the authentic CS protein on live sporozoites and blocked sporozoite invasion of human hepatoma cells in vitro. These CS protein derivatives are therefore candidates for a human malaria vaccine.

Structural correlates of carrier protein recognition in tetanus toxoid-conjugated bacterial polysaccharide vaccines.

PubMed

Lockyer, Kay; Gao, Fang; Derrick, Jeremy P; Bolgiano, Barbara

2015-03-10

An analysis of structure-antibody recognition relationships in nine licenced polysaccharide-tetanus toxoid (TT) conjugate vaccines was performed. The panel of conjugates used included vaccine components to protect against disease caused by Haemophilus influenzae type b, Neisseria meningitidis groups A, C, W and Y and Streptococcus pneumoniae serotype 18C. Conformation and structural analysis included size exclusion chromatography with multi-angle light scattering to determine size, and intrinsic fluorescence spectroscopy and fluorescence quenching to evaluate the protein folding and exposure of Trp residues. A capture ELISA measured the recognition of TT epitopes in the conjugates, using four rat monoclonal antibodies: 2 localised to the HC domain, and 2 of which were holotoxoid conformation-dependent. The conjugates had a wide range of average molecular masses ranging from 1.8×10(6) g/mol to larger than 20×10(6) g/mol. The panel of conjugates were found to be well folded, and did not have spectral features typical of aggregated TT. A partial correlation was found between molecular mass and epitope recognition. Recognition of the epitopes either on the HC domain or the whole toxoid was not necessarily hampered by the size of the molecule. Correlation was also found between the accessibility of Trp side chains and polysaccharide loading, suggesting also that a higher level of conjugated PS does not necessarily interfere with toxoid accessibility. There were different levels of carrier protein Trp side-chain and epitope accessibility that were localised to the HC domain; these were related to the saccharide type, despite the conjugates being independently manufactured. These findings extend our understanding of the molecular basis for carrier protein recognition in TT conjugate vaccines. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Structural correlates of carrier protein recognition in tetanus toxoid-conjugated bacterial polysaccharide vaccines

PubMed Central

Lockyer, Kay; Gao, Fang; Derrick, Jeremy P.; Bolgiano, Barbara

2015-01-01

An analysis of structure-antibody recognition relationships in nine licenced polysaccharide-tetanus toxoid (TT) conjugate vaccines was performed. The panel of conjugates used included vaccine components to protect against disease caused by Haemophilus influenzae type b, Neisseria meningitidis groups A, C, W and Y and Streptococcus pneumoniae serotype 18C. Conformation and structural analysis included size exclusion chromatography with multi-angle light scattering to determine size, and intrinsic fluorescence spectroscopy and fluorescence quenching to evaluate the protein folding and exposure of Trp residues. A capture ELISA measured the recognition of TT epitopes in the conjugates, using four rat monoclonal antibodies: 2 localised to the HC domain, and 2 of which were holotoxoid conformation-dependent. The conjugates had a wide range of average molecular masses ranging from 1.8 × 106 g/mol to larger than 20 × 106 g/mol. The panel of conjugates were found to be well folded, and did not have spectral features typical of aggregated TT. A partial correlation was found between molecular mass and epitope recognition. Recognition of the epitopes either on the HC domain or the whole toxoid was not necessarily hampered by the size of the molecule. Correlation was also found between the accessibility of Trp side chains and polysaccharide loading, suggesting also that a higher level of conjugated PS does not necessarily interfere with toxoid accessibility. There were different levels of carrier protein Trp side-chain and epitope accessibility that were localised to the HC domain; these were related to the saccharide type, despite the conjugates being independently manufactured. These findings extend our understanding of the molecular basis for carrier protein recognition in TT conjugate vaccines. PMID:25640334

Merozoite surface proteins in red blood cell invasion, immunity and vaccines against malaria

PubMed Central

Beeson, James G.; Drew, Damien R.; Boyle, Michelle J.; Feng, Gaoqian; Fowkes, Freya J.I.; Richards, Jack S.

2016-01-01

Malaria accounts for an enormous burden of disease globally, with Plasmodium falciparum accounting for the majority of malaria, and P. vivax being a second important cause, especially in Asia, the Americas and the Pacific. During infection with Plasmodium spp., the merozoite form of the parasite invades red blood cells and replicates inside them. It is during the blood-stage of infection that malaria disease occurs and, therefore, understanding merozoite invasion, host immune responses to merozoite surface antigens, and targeting merozoite surface proteins and invasion ligands by novel vaccines and therapeutics have been important areas of research. Merozoite invasion involves multiple interactions and events, and substantial processing of merozoite surface proteins occurs before, during and after invasion. The merozoite surface is highly complex, presenting a multitude of antigens to the immune system. This complexity has proved challenging to our efforts to understand merozoite invasion and malaria immunity, and to developing merozoite antigens as malaria vaccines. In recent years, there has been major progress in this field, and several merozoite surface proteins show strong potential as malaria vaccines. Our current knowledge on this topic is reviewed, highlighting recent advances and research priorities. PMID:26833236

Merozoite surface proteins in red blood cell invasion, immunity and vaccines against malaria.

PubMed

Beeson, James G; Drew, Damien R; Boyle, Michelle J; Feng, Gaoqian; Fowkes, Freya J I; Richards, Jack S

2016-05-01

Malaria accounts for an enormous burden of disease globally, with Plasmodium falciparum accounting for the majority of malaria, and P. vivax being a second important cause, especially in Asia, the Americas and the Pacific. During infection with Plasmodium spp., the merozoite form of the parasite invades red blood cells and replicates inside them. It is during the blood-stage of infection that malaria disease occurs and, therefore, understanding merozoite invasion, host immune responses to merozoite surface antigens, and targeting merozoite surface proteins and invasion ligands by novel vaccines and therapeutics have been important areas of research. Merozoite invasion involves multiple interactions and events, and substantial processing of merozoite surface proteins occurs before, during and after invasion. The merozoite surface is highly complex, presenting a multitude of antigens to the immune system. This complexity has proved challenging to our efforts to understand merozoite invasion and malaria immunity, and to developing merozoite antigens as malaria vaccines. In recent years, there has been major progress in this field, and several merozoite surface proteins show strong potential as malaria vaccines. Our current knowledge on this topic is reviewed, highlighting recent advances and research priorities. © FEMS 2016.

Vaccination of carp against SVCV with an oral DNA vaccine or an insect cells-based subunit vaccine.

PubMed

Embregts, C W E; Rigaudeau, D; Tacchi, L; Pijlman, G P; Kampers, L; Veselý, T; Pokorová, D; Boudinot, P; Wiegertjes, G F; Forlenza, M

2018-03-19

We recently reported on a successful vaccine for carp against SVCV based on the intramuscular injection of a DNA plasmid encoding the SVCV glycoprotein (SVCV-G). This shows that the intramuscular (i.m.) route of vaccination is suitable to trigger protective responses against SVCV, and that the SVCV G-protein is a suitable vaccine antigen. Yet, despite the general success of DNA vaccines, especially against fish rhabdoviruses, their practical implementation still faces legislative as well as consumer's acceptance concerns. Furthermore, the i.m. route of plasmid administration is not easily combined with most of the current vaccination regimes largely based on intraperitoneal or immersion vaccination. For this reason, in the current study we evaluated possible alternatives to a DNA-based i.m. injectable vaccine using the SVCV-G protein as the vaccine antigen. To this end, we tested two parallel approaches: the first based on the optimization of an alginate encapsulation method for oral delivery of DNA and protein antigens; the second based on the baculovirus recombinant expression of transmembrane SVCV-G protein in insect cells, administered as whole-cell subunit vaccine through the oral and injection route. In addition, in the case of the oral DNA vaccine, we also investigated the potential benefits of the mucosal adjuvants Escherichia coli lymphotoxin subunit B (LTB). Despite the use of various vaccine types, doses, regimes, and administration routes, no protection was observed, contrary to the full protection obtained with our reference i.m. DNA vaccine. The limited protection observed under the various conditions used in this study, the nature of the host, of the pathogen, the type of vaccine and encapsulation method, will therefore be discussed in details to provide an outlook for future vaccination strategies against SVCV. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Serum Cytokine Profiles Associated with Specific Adjuvants Used in a DNA Prime-Protein Boost Vaccination Strategy

PubMed Central

Buglione-Corbett, Rachel; Pouliot, Kimberly; Marty-Roix, Robyn; West, Kim; Wang, Shixia; Lien, Egil; Lu, Shan

2013-01-01

In recent years, heterologous prime-boost vaccines have been demonstrated to be an effective strategy for generating protective immunity, consisting of both humoral and cell-mediated immune responses against a variety of pathogens including HIV-1. Previous reports of preclinical and clinical studies have shown the enhanced immunogenicity of viral vector or DNA vaccination followed by heterologous protein boost, compared to using either prime or boost components alone. With such approaches, the selection of an adjuvant for inclusion in the protein boost component is expected to impact the immunogenicity and safety of a vaccine. In this study, we examined in a mouse model the serum cytokine and chemokine profiles for several candidate adjuvants: QS-21, Al(OH)3, monophosphoryl lipid A (MPLA) and ISCOMATRIX™ adjuvant, in the context of a previously tested pentavalent HIV-1 Env DNA prime-protein boost formulation, DP6-001. Our data revealed that the candidate adjuvants in the context of the DP6-001 formulation are characterized by unique serum cytokine and chemokine profiles. Such information will provide valuable guidance in the selection of an adjuvant for future AIDS vaccine development, with the ultimate goal of enhancing immunogenicity while minimizing reactogenicity associated with the use of an adjuvant. More significantly, results reported here will add to the knowledge on how to include an adjuvant in the context of a heterologous prime-protein boost vaccination strategy in general. PMID:24019983

Cellular Immune Responses to Nine Mycobacterium tuberculosis Vaccine Candidates following Intranasal Vaccination

PubMed Central

Sable, Suraj B.; Cheruvu, Mani; Nandakumar, Subhadra; Sharma, Sunita; Bandyopadhyay, Kakali; Kellar, Kathryn L.; Posey, James E.; Plikaytis, Bonnie B.; Amara, Rama Rao; Shinnick, Thomas M.

2011-01-01

Background The identification of Mycobacterium tuberculosis vaccines that elicit a protective immune response in the lungs is important for the development of an effective vaccine against tuberculosis. Methods and Principal Findings In this study, a comparison of intranasal (i.n.) and subcutaneous (s.c.) vaccination with the BCG vaccine demonstrated that a single moderate dose delivered intranasally induced a stronger and sustained M. tuberculosis-specific T-cell response in lung parenchyma and cervical lymph nodes of BALB/c mice than vaccine delivered subcutaneously. Both BCG and a multicomponent subunit vaccine composed of nine M. tuberculosis recombinant proteins induced strong antigen-specific T-cell responses in various local and peripheral immune compartments. Among the nine recombinant proteins evaluated, the alanine proline rich antigen (Apa, Rv1860) was highly antigenic following i.n. BCG and immunogenic after vaccination with a combination of the nine recombinant antigens. The Apa-induced responses included induction of both type 1 and type 2 cytokines in the lungs as evaluated by ELISPOT and a multiplexed microsphere-based cytokine immunoassay. Of importance, i.n. subunit vaccination with Apa imparted significant protection in the lungs and spleen of mice against M. tuberculosis challenge. Despite observed differences in the frequencies and location of specific cytokine secreting T cells both BCG vaccination routes afforded comparable levels of protection in our study. Conclusion and Significance Overall, our findings support consideration and further evaluation of an intranasally targeted Apa-based vaccine to prevent tuberculosis. PMID:21799939

Vaccinating Girls and Boys with Different Human Papillomavirus Vaccines: Can It Optimise Population-Level Effectiveness?

PubMed Central

Drolet, Mélanie; Boily, Marie-Claude; Van de Velde, Nicolas; Franco, Eduardo L.; Brisson, Marc

2013-01-01

Background Decision-makers may consider vaccinating girls and boys with different HPV vaccines to benefit from their respective strengths; the quadrivalent (HPV4) prevents anogenital warts (AGW) whilst the bivalent (HPV2) may confer greater cross-protection. We compared, to a girls-only vaccination program with HPV4, the impact of vaccinating: 1) both genders with HPV4, and 2) boys with HPV4 and girls with HPV2. Methods We used an individual-based transmission-dynamic model of heterosexual HPV infection and diseases. Our base-case scenario assumed lifelong efficacy of 100% against vaccine types, and 46,29,8,18,6% and 77,43,79,8,0% efficacy against HPV-31,-33,-45,-52,-58 for HPV4 and HPV2, respectively. Results Assuming 70% vaccination coverage and lifelong cross-protection, vaccinating boys has little additional benefit on AGW prevention, irrespective of the vaccine used for girls. Furthermore, using HPV4 for boys and HPV2 for girls produces greater incremental reductions in SCC incidence than using HPV4 for both genders (12 vs 7 percentage points). At 50% vaccination coverage, vaccinating boys produces incremental reductions in AGW of 17 percentage points if both genders are vaccinated with HPV4, but increases female incidence by 16 percentage points if girls are switched to HPV2 (heterosexual male incidence is incrementally reduced by 24 percentage points in both scenarios). Higher incremental reductions in SCC incidence are predicted when vaccinating boys with HPV4 and girls with HPV2 versus vaccinating both genders with HPV4 (16 vs 12 percentage points). Results are sensitive to vaccination coverage and the relative duration of protection of the vaccines. Conclusion Vaccinating girls with HPV2 and boys with HPV4 can optimize SCC prevention if HPV2 has higher/longer cross-protection, but can increase AGW incidence if vaccination coverage is low among boys. PMID:23840589

Vaccines against stimulants: cocaine and MA

PubMed Central

Kosten, Thomas; Domingo, Coreen; Orson, Frank; Kinsey, Berma

2014-01-01

While the worldwide prevalence of cocaine use remains significant, medications, or small molecule approaches, to treat drug addictions have met with limited success. Anti-addiction vaccines, on the other hand, have demonstrated great potential for treating drug abuse using a distinctly different mechanism of eliciting an antibody response that blocks the pharmacological effects of drugs. We provide a review of vaccine-based approaches to treating stimulant addictions; specifically and cocaine addictions. This selective review article focuses on the one cocaine vaccine that has been into clinical trials and presents new data related to pre-clinical development of a methamphetamine (MA) vaccine. We also review the mechanism of action for vaccine induced antibodies to abused drugs, which involves kinetic slowing of brain entry as well as simple blocking properties. We present pre-clinical innovations for MA vaccines including hapten design, linkage to carrier proteins and new adjuvants beyond alum. We provide some new information on hapten structures and linkers and variations in protein carriers. We consider a carrier, outer membrance polysaccharide coat protein (OMPC), that provides some self-adjuvant through lipopolysaccharide components and provide new results with a monophosopholipid adjuvant for the more standard carrier proteins with cocaine and MA. The review then covers the clinical trials with the cocaine vaccine TA-CD. The clinical prospects for advances in this field over the next few years include a multi-site cocaine vaccine clinical trial to be reported in 2013 and phase 1 clinical trials of a MA vaccine in 2014. PMID:23509915

Vaccines against stimulants: cocaine and MA.

PubMed

Kosten, Thomas; Domingo, Coreen; Orson, Frank; Kinsey, Berma

2014-02-01

While the worldwide prevalence of cocaine use remains significant, medications, or small molecule approaches, to treat drug addictions have met with limited success. Anti-addiction vaccines, on the other hand, have demonstrated great potential for treating drug abuse using a distinctly different mechanism of eliciting an antibody response that blocks the pharmacological effects of drugs. We provide a review of vaccine-based approaches to treating stimulant addictions; specifically and cocaine addictions. This selective review article focuses on the one cocaine vaccine that has been into clinical trials and presents new data related to pre-clinical development of a methamphetamine (MA) vaccine. We also review the mechanism of action for vaccine induced antibodies to abused drugs, which involves kinetic slowing of brain entry as well as simple blocking properties. We present pre-clinical innovations for MA vaccines including hapten design, linkage to carrier proteins and new adjuvants beyond alum. We provide some new information on hapten structures and linkers and variations in protein carriers. We consider a carrier, outer membrance polysaccharide coat protein (OMPC), that provides some self-adjuvant through lipopolysaccharide components and provide new results with a monophosopholipid adjuvant for the more standard carrier proteins with cocaine and MA. The review then covers the clinical trials with the cocaine vaccine TA-CD. The clinical prospects for advances in this field over the next few years include a multi-site cocaine vaccine clinical trial to be reported in 2013 and phase 1 clinical trials of a MA vaccine in 2014. © 2013 The British Pharmacological Society.

Tracking by flow cytometry antigen-specific follicular helper T cells in wild-type animals after protein vaccination.

PubMed

Chakarov, Svetoslav; Fazilleau, Nicolas

2015-01-01

Flow cytometry is a valuable technology used in immunology to characterize and enumerate the different cell subpopulations specific for a nonself-antigen in the context of an ongoing immune response. Among them, follicular helper T cells are the cognate regulators of B cells in secondary lymphoid tissues. Thus, tracking them is of high interest especially in the context of protein vaccination. For this purpose, transgenic antigen-receptor mouse models have been largely used. It is now clear that transgenic models are not always the best means to study the dynamics of the immune response since they can modify the response. In this chapter, we describe how to track endogenous antigen-specific follicular helper T cells by flow cytometry after protein vaccination in nonmodified wild-type animals, which ultimately provides a comprehensive way to enumerate, characterize, and isolate these particular cells in vivo.

Specific Genetic Immunotherapy Induced by Recombinant Vaccine Alpha-Fetoprotein-Heat Shock Protein 70 Complex

NASA Astrophysics Data System (ADS)

Wang, Xiaoping; Lin, Huanping; Wang, Qiaoxia

Purposes: To construct a recombinant vaccine alpha-fetoprotein (AFP)-heat shock protein (HSP70) complex, and study its ability to induce specific CTL response and its protective effect against AFP-producing tumor. Material/Methods: A recombinant vaccine was constructed by conjugating mouse alpha-fetoprotein to heat shock protein 70. By way of intracutaneous injection, mice were primed and boosted with recombinant vaccine mAFP/HSP70, whereas single mAFP or HSP70 injection as controls. The ELISPOT and ELISA were used to measure the frequency of cells producing the cytokine IFN-γ in splenocytes and the level of anti-AFP antibody of serum from immunized mice respectively. In vivo tumor challenge were carried out to assess the immune effect of the recombinant vaccine. Results: By recombinant mAFP/HSP70 vaccine immunization, the results of ELISPOT and ELISA showed that the number of splenic cells producing IFN-γ and the level of anti-AFP antibody of serum were significantly higher in mAFP/HSP70 group than those in mAFP and HSP70 groups (108.50±11.70 IFN-γ spots/106 cells vs 41.60±10.40 IFN-γ spots/106 cells, 7.32±3.14 IFN-γ spots/106 cells, P<0.01; 156.32±10.42 μg/mL vs 66.52±7.35 μg/mL, 5.73±2.89 μg/mL, P<0.01). The tumor volume in mAFP/HSP70 group was significantly smaller than that in mAFP and HSP70 groups (42.44±7.14 mm3 vs 392.23±12.46 mm3, 838.63±13.84 mm3, P<0.01). Conclusions: The study further confirmed the function of heat shock protein 70's immune adjuvant. Sequential immunization with recombinant mAFP/HSP70 vaccine could generate effective antitumor immunity on AFP-producing tumor. The recombined mAFP/HSP70 vaccine may be suitable for serving as an immunotherapy for hepatocellular carcinoma.

Comparison of immune responses to different foot-and-mouth disease genetically engineered vaccines in guinea pigs.

PubMed

Yao, Qingxia; Qian, Ping; Huang, Qinfeng; Cao, Yi; Chen, Huanchun

2008-01-01

The P12A3C gene from FMDV (serotype O) encoding the capsid precursor protein, and the highly immunogenic gene FHG, which encodes multiple epitopes of FMDV capsid proteins, were inserted into eukaryotic expression vectors to compare different candidate genetically engineered vaccines for foot-and-mouth disease (FMD). A modified live pseudorabies virus (MLPRV) was also used to deliver P12A3C. Guinea pigs were inoculated intramuscularly with the candidate vaccines to compare the ability to elicit immunity of the DNA vector and a live viral vector. An indirect enzyme-linked immunosorbent assay (iELISA), virus-neutralization test and lymphoproliferation assay were used to detect antibody and cellular responses. The group immunized with P12A3C delivered by MLPRV produced significantly greater antibody and cellular responses indicating that MLPRV has a greater ability to mediate exogenous gene delivery than the plasmid DNA vector. Comparison of the immune responses induced by P12A3C and FHG, which were both mediated by DNA plasmids, showed that FHG and P12A3C elicited similar cellular responses, while P12A3C induced higher antibody levels, suggesting that P12A3C is a more powerful immunogen than FHG. In challenge experiments, guinea pigs vaccinated with P12A3C delivered by MLPRV were protected fully from FMDV challenge, whereas guinea pigs vaccinated with P12A3C or FHG delivered by DNA plasmid were only protected partially. This study provides a basis for future construction of a genetically engineered vaccine for FMDV.

Development of a SARS Coronavirus Vaccine from Recombinant Spike Protein Plus Delta Inulin Adjuvant.

PubMed

McPherson, Clifton; Chubet, Richard; Holtz, Kathy; Honda-Okubo, Yoshikazu; Barnard, Dale; Cox, Manon; Petrovsky, Nikolai

2016-01-01

Given periodic outbreaks of fatal human infections caused by coronaviruses, development of an optimal coronavirus vaccine platform capable of rapid production is an ongoing priority. This chapter describes the use of an insect cell expression system for rapid production of a recombinant vaccine against severe acute respiratory syndrome coronavirus (SARS). Detailed methods are presented for expression, purification, and release testing of SARS recombinant spike protein antigen, followed by adjuvant formulation and animal testing. The methods herein described for rapid development of a highly protective SARS vaccine are equally suited to rapid development of vaccines against other fatal human coronavirus infections, e.g., the MERS coronavirus.

Estimation of lactose interference in vaccines and a proposal of methodological adjustment of total protein determination by the lowry method.

PubMed

Kusunoki, Hideki; Okuma, Kazu; Hamaguchi, Isao

2012-01-01

For national regulatory testing in Japan, the Lowry method is used for the determination of total protein content in vaccines. However, many substances are known to interfere with the Lowry method, rendering accurate estimation of protein content difficult. To accurately determine the total protein content in vaccines, it is necessary to identify the major interfering substances and improve the methodology for removing such substances. This study examined the effects of high levels of lactose with low levels of protein in freeze-dried, cell culture-derived Japanese encephalitis vaccine (inactivated). Lactose was selected because it is a reducing sugar that is expected to interfere with the Lowry method. Our results revealed that concentrations of ≥ 0.1 mg/mL lactose interfered with the Lowry assays and resulted in overestimation of the protein content in a lactose concentration-dependent manner. On the other hand, our results demonstrated that it is important for the residual volume to be ≤ 0.05 mL after trichloroacetic acid precipitation in order to avoid the effects of lactose. Thus, the method presented here is useful for accurate protein determination by the Lowry method, even when it is used for determining low levels of protein in vaccines containing interfering substances. In this study, we have reported a methodological adjustment that allows accurate estimation of protein content for national regulatory testing, when the vaccine contains interfering substances.

Contextualizing educational differences in "vaccination uptake": A thirty nation survey.

PubMed

Makarovs, Kirils; Achterberg, Peter

2017-09-01

This paper addresses the issue of public acceptance of vaccination with specific attention being paid to the role of education in vaccine uptake. Using Flash Eurobarometer 287 (2009) survey data and exploring it through the lens of Beck's reflexive modernization and Roger's protection motivation theories we examined how individual-level factors affect intention to get vaccinated, particularly aimed at examining whether higher education predicts more or less vaccination intention in different societies. The empirical results support an idea that at least for seasonal flu educational differences in vaccination uptake are contextual upon the reflexivity of the society in which respondent happens to live. Educated people living in more reflexive modernized countries tend to oppose vaccination against seasonal flu more that those highly educated living in less advanced societies, indicating that skeptical attitude towards science that is intrinsic to the modern post-industrial nations induces the immunization opposition among most informed and distrustful social group. Copyright © 2017 Elsevier Ltd. All rights reserved.

A protein-based smallpox vaccine protects mice from vaccinia and ectromelia virus challenges when given as a prime and single boost

PubMed Central

Xiao, Yuhong; Aldaz-Carroll, Lydia; Ortiz, Alexandra M.; Whitbeck, J. Charles; Alexander, Edward; Lou, Huan; Davis, J. Heather L.; Braciale, Thomas J.; Eisenberg, Roselyn J.; Cohen, Gary H.; Isaacs, Stuart N.

2007-01-01

The heightened concern about the intentional release of variola virus has led to the need to develop safer smallpox vaccines. While subunit vaccine strategies are safer than live virus vaccines, subunit vaccines have been hampered by the need for multiple boosts to confer optimal protection. Here we developed a protein-based subunit vaccine strategy that provides rapid protection in mouse models of orthopoxvirus infections after a prime and single boost. Mice vaccinated with vaccinia virus envelope proteins from the mature virus (MV) and extracellular virus (EV) adjuvanted with CpG-ODN and alum were protected from lethal intranasal challenge with vaccinia virus and the mouse-specific ectromelia virus. Organs from mice vaccinated with three proteins (A33, B5 and L1) and then sacrificed after challenge contained significantly lower titers of virus when compared to control groups of mice that were not vaccinated or that received sub-optimal formulations of the vaccine. Sera from groups of mice obtained prior to challenge had neutralizing activity against the MV and also inhibited comet formation indicating anti-EV activity. Long-term partial protection was also seen in mice challenged with vaccinia virus 6 months after initial vaccinations. Thus, this work represents a step toward the development of a practical subunit smallpox vaccine. PMID:17098336

A clinical trial examining the effect of increased total CRM(197) carrier protein dose on the antibody response to Haemophilus influenzae type b CRM(197) conjugate vaccine.

PubMed

Usonis, Vytautas; Bakasenas, Vytautas; Lockhart, Stephen; Baker, Sherryl; Gruber, William; Laudat, France

2008-08-18

CRM(197) is a carrier protein in certain conjugate vaccines. When multiple conjugate vaccines with the same carrier protein are administered simultaneously, reduced response to vaccines and/or antigens related to the carrier protein may occur. This study examined responses of infants who, in addition to diphtheria toxoid/tetanus toxoid/acellular pertussis vaccine (DTaP) received either diphtheria CRM(197)-based Haemophilus influenzae type b conjugate vaccine (HbOC) or HbOC and a diphtheria CRM(197)-based combination 9-valent pneumococcal conjugate vaccine/meningococcal group C conjugate vaccine. Administration of conjugate vaccines with CRM(197) carrier protein load >50 microg did not reduce response to CRM(197) conjugate vaccines or immunogenicity to immunologically cross-reactive diphtheria toxoid.

[Anaphylaxis after vaccination due to hypersensitivity to gelatin].

PubMed

Kamin, W; Staubach, P; Klär-Hlawatsch, B; Erdnüss, F; Knuf, M

2006-01-01

Most allergic reactions after vaccination occur in patients sensitive to egg protein. Therefore this subject is well investigated, and the majority of common vaccines today contain only traces of egg protein. In contrast, there is little knowledge of hypersensitivities to other substances frequently contained in vaccines, e. g. antibiotics, phenol, gelatin and different preservatives. Here we report the case of a boy who had an anaphylactic reaction after being vaccinated against measles, mumps, rubella (MMR), and tick-born encephalitis (TBE) simultaneously. Different tests finally revealed a hypersensitivity to gelatin. This should be kept in mind especially during emergency care, since gelatin containing products like Haemaccel, Gelifundol or Gelofusin are widely used as colloid for resuscitation. If type 1 reactions after vaccination occur, gelatin should be taken into account as the causative agent. A medical alert card is recommended for such patients.

Computational identification, characterization and validation of potential antigenic peptide vaccines from hrHPVs E6 proteins using immunoinformatics and computational systems biology approaches

PubMed Central

Junaid, Muhammad; Kaushik, Aman Chandra; Ali, Arif; Ali, Syed Shujait; Mehmood, Aamir; Wei, Dong-Qing

2018-01-01

High-risk human papillomaviruses (hrHPVs) are the most prevalent viruses in human diseases including cervical cancers. Expression of E6 protein has already been reported in cervical cancer cases, excluding normal tissues. Continuous expression of E6 protein is making it ideal to develop therapeutic vaccines against hrHPVs infection and cervical cancer. Therefore, we carried out a meta-analysis of multiple hrHPVs to predict the most potential prophylactic peptide vaccines. In this study, immunoinformatics approach was employed to predict antigenic epitopes of hrHPVs E6 proteins restricted to 12 Human HLAs to aid the development of peptide vaccines against hrHPVs. Conformational B-cell and CTL epitopes were predicted for hrHPVs E6 proteins using ElliPro and NetCTL. The potential of the predicted peptides were tested and validated by using systems biology approach considering experimental concentration. We also investigated the binding interactions of the antigenic CTL epitopes by using docking. The stability of the resulting peptide-MHC I complexes was further studied by molecular dynamics simulations. The simulation results highlighted the regions from 46–62 and 65–76 that could be the first choice for the development of prophylactic peptide vaccines against hrHPVs. To overcome the worldwide distribution, the predicted epitopes restricted to different HLAs could cover most of the vaccination and would help to explore the possibility of these epitopes for adaptive immunotherapy against HPVs infections. PMID:29715318

DNA vaccines encoding the envelope protein of West Nile virus lineages 1 or 2 administered intramuscularly, via electroporation and with recombinant virus protein induce partial protection in large falcons (Falco spp.).

PubMed

Fischer, Dominik; Angenvoort, Joke; Ziegler, Ute; Fast, Christine; Maier, Kristina; Chabierski, Stefan; Eiden, Martin; Ulbert, Sebastian; Groschup, Martin H; Lierz, Michael

2015-08-17

As West Nile virus (WNV) can cause lethal diseases in raptors, a vaccination prophylaxis of free-living and captive populations is desirable. In the absence of vaccines approved for birds, equine vaccines have been used in falcons, but full protection against WNV infection was not achieved. Therefore, two DNA vaccines encoding the ectodomain of the envelope protein of WNV lineages 1 and 2, respectively, were evaluated in 28 large falcons. Four different vaccination protocols were used, including electroporation and booster-injections of recombinant WNV domain III protein, before challenge with the live WNV lineage 1 strain NY99. Drug safety, plasmid shedding and antibody production were monitored during the vaccination period. Serological, virological, histological, immunohistochemical and molecular biological investigations were performed during the challenge trials. Antibody response following vaccination was low overall and lasted for a maximum of three weeks. Plasmid shedding was not detected at any time. Viremia, mortality and levels, but not duration, of oral virus shedding were reduced in all of the groups during the challenge trial compared to the non-vaccinated control group. Likewise, clinical scoring, levels of cloacal virus shedding and viral load in organs were significantly reduced in three vaccination groups. Histopathological findings associated with WNV infections (meningo-encephalitis, myocarditis, and arteritis) were present in all groups, but immunohistochemical detection of the viral antigen was reduced. In conclusion, the vaccines can be used safely in falcons to reduce mortality and clinical signs and to lower the risk of virus transmission due to decreased levels of virus shedding and viremia, but full protection was not achieved in all groups.

Cysteine mutagenesis improves the production without abrogating antigenicity of a recombinant protein vaccine candidate for human chagas disease.

PubMed

Seid, Christopher A; Jones, Kathryn M; Pollet, Jeroen; Keegan, Brian; Hudspeth, Elissa; Hammond, Molly; Wei, Junfei; McAtee, C Patrick; Versteeg, Leroy; Gutierrez, Amanda; Liu, Zhuyun; Zhan, Bin; Respress, Jonathan L; Strych, Ulrich; Bottazzi, Maria Elena; Hotez, Peter J

2017-03-04

A therapeutic vaccine for human Chagas disease is under development by the Sabin Vaccine Institute Product Development Partnership. The aim of the vaccine is to significantly reduce the parasite burden of Trypanosoma cruzi in humans, either as a standalone product or in combination with conventional chemotherapy. Vaccination of mice with Tc24 formulated with monophosphoryl-lipid A (MPLA) adjuvant results in a Th1 skewed immune response with elevated IgG2a and IFNγ levels and a statistically significant decrease in parasitemia following T. cruzi challenge. Tc24 was therefore selected for scale-up and further evaluation. During scale up and downstream process development, significant protein aggregation was observed due to intermolecular disulfide bond formation. To prevent protein aggregation, cysteine codons were replaced with serine codons which resulted in the production of a non-aggregated and soluble recombinant protein, Tc24-C4. No changes to the secondary structure of the modified molecule were detected by circular dichroism. Immunization of mice with wild-type Tc24 or Tc24-C4, formulated with E6020 (TLR4 agonist analog to MPLA) emulsified in a squalene-oil-in-water emulsion, resulted in IgG2a and antigen specific IFNγ production levels from splenocytes that were not significantly different, indicating that eliminating putative intermolecular disulfide bonds had no significant impact on the immunogenicity of the molecule. In addition, vaccination with either formulated wild type Tc24 or Tc24-C4 antigen also significantly increased survival and reduced cardiac parasite burden in mice. Investigations are now underway to examine the efficacy of Tc24-C4 formulated with other adjuvants to reduce parasite burden and increase survival in pre-clinical studies.

Cysteine mutagenesis improves the production without abrogating antigenicity of a recombinant protein vaccine candidate for human chagas disease

PubMed Central

Jones, Kathryn M.; Keegan, Brian; Hudspeth, Elissa; Hammond, Molly; Wei, Junfei; McAtee, C. Patrick; Versteeg, Leroy; Gutierrez, Amanda; Liu, Zhuyun; Zhan, Bin; Respress, Jonathan L.; Strych, Ulrich; Bottazzi, Maria Elena; Hotez, Peter J.

2017-01-01

ABSTRACT A therapeutic vaccine for human Chagas disease is under development by the Sabin Vaccine Institute Product Development Partnership. The aim of the vaccine is to significantly reduce the parasite burden of Trypanosoma cruzi in humans, either as a standalone product or in combination with conventional chemotherapy. Vaccination of mice with Tc24 formulated with monophosphoryl-lipid A (MPLA) adjuvant results in a Th1 skewed immune response with elevated IgG2a and IFNγ levels and a statistically significant decrease in parasitemia following T. cruzi challenge. Tc24 was therefore selected for scale-up and further evaluation. During scale up and downstream process development, significant protein aggregation was observed due to intermolecular disulfide bond formation. To prevent protein aggregation, cysteine codons were replaced with serine codons which resulted in the production of a non-aggregated and soluble recombinant protein, Tc24-C4. No changes to the secondary structure of the modified molecule were detected by circular dichroism. Immunization of mice with wild-type Tc24 or Tc24-C4, formulated with E6020 (TLR4 agonist analog to MPLA) emulsified in a squalene-oil-in-water emulsion, resulted in IgG2a and antigen specific IFNγ production levels from splenocytes that were not significantly different, indicating that eliminating putative intermolecular disulfide bonds had no significant impact on the immunogenicity of the molecule. In addition, vaccination with either formulated wild type Tc24 or Tc24-C4 antigen also significantly increased survival and reduced cardiac parasite burden in mice. Investigations are now underway to examine the efficacy of Tc24-C4 formulated with other adjuvants to reduce parasite burden and increase survival in pre-clinical studies. PMID:27737611

Protection of Mice against Plasmodium yoelii Sporozoite Challenge with P. yoelii Merozoite Surface Protein 1 DNA Vaccines

PubMed Central

Becker, Sylvia I.; Wang, Ruobing; Hedstrom, Richard C.; Aguiar, Joao C.; Jones, Trevor R.; Hoffman, Stephen L.; Gardner, Malcolm J.

1998-01-01

Immunization of mice with DNA vaccines encoding the full-length form and C and N termini of Plasmodium yoelii merozoite surface protein 1 provided partial protection against sporozoite challenge and resulted in boosting of antibody titers after challenge. In C57BL/6 mice, two DNA vaccines provided protection comparable to that of recombinant protein consisting of the C terminus in Freund’s adjuvant. PMID:9632624

[Economic evaluation on different two-dose-vaccination-strategies related to Measles, Mumps and Rubella Combined Attenuated Live Vaccine].

PubMed

He, H Q; Zhang, B; Yan, R; Li, Q; Fu, J; Tang, X W; Zhou, Y; Deng, X; Xie, S Y

2016-08-10

To evaluate the economic effect of Measles, Mumps and Rubella Combined Attenuated Live Vaccine (MMR) under different two-dose vaccination programs. A hypothetical birth cohort of 750 000 infants over their lifetime, was followed up from birth through death in Zhejiang province. The current MMR vaccination strategie would include three different ones: 1) Childlern were vaccinated with Measles-Rubella Combined Attenuated Live Vaccine and MMR, respectively at the age of 8 months and 18 months. 2) Children receive MMR at 8 months and 18 months, 3) Strategy 1 plus an additional vaccination of MMR at 4 years of age. Incremental cost-effectiveness ratio (ICER), incremental cost-benefit ratio (ICBR) and incremental net benefit (INB) were applied to calculate the health economic difference for Strategy 2 and Strategy 3 as compared to Strategy 1. Univariate sensitivity analysis was used to assess the robustness of results with main parameters, including the rate of immunization coverage, effectiveness of the vaccines, incidence and burdens of the related diseases, cost of vaccines and the vaccination program itself. ICER, ICBR and INB for Strategy 2 and Strategy 3 appeared as 2 012.51∶1 RMB Yuan per case and 4 238.72∶1 RMB Yuan per case, 1∶3.14 and 1∶1.58, 21 277 800 RMB Yuan and 9 276 500 RMB Yuan, respectively. Only slight changes (<20%) were found under the univariate sensitivity analysis, with varied values on main parameters. Based on the current national immunization program, infants vaccinated with MMR at 8 months of age, generated more health economic effects than the Strategy 3.

Reactogenicity, safety and immunogenicity of a protein-based pneumococcal vaccine in Gambian children aged 2-4 years: A phase II randomized study.

PubMed

Odutola, A; Ota, M O; Ogundare, E O; Antonio, M; Owiafe, P; Worwui, A; Greenwood, B; Alderson, M; Traskine, M; Verlant, V; Dobbelaere, K; Borys, D

2016-01-01

Pneumococcal conjugate vaccines (PCVs) have been successful in preventing invasive pneumococcal disease but effectiveness has been challenged by replacement of vaccine serotypes with non-vaccine serotypes. Vaccines targeting common pneumococcal protein(s) found in most/all pneumococci may overcome this limitation. This phase II study assessed safety and immunogenicity of a new protein-based pneumococcal vaccine containing polysaccharide conjugates of 10 pneumococcal serotypes combined with pneumolysin toxoid(dPly) and pneumococcal histidine triad protein D(PhtD) (PHiD-CV/dPly/PhtD-30) in African children. 120 Gambian children (2-4 years, not previously vaccinated against Streptococcus pneumoniae) randomized (1:1) received a single dose of PHiD-CV/dPly/PhtD-30 or PCV13. Adverse events occurring over 4 d post-vaccination were reported, and blood samples obtained pre- and 1-month post-vaccination. Serious adverse events were reported for 6 months post-vaccination. Solicited local and systemic adverse events were reported at similar frequency in each group. One child (PHiD-CV/dPly/PhtD-30 group) reported a grade 3 local reaction to vaccination. Haematological and biochemical parameters seemed similar pre- and 1-month post-vaccination in each group. High pre-vaccination Ply and PhtD antibody concentrations were observed in each group, but only increased in PHiD-CV/dPly/PhtD-30 vaccinees one month post-vaccination. One month post-vaccination, for each vaccine serotype ≥96.2% of PHiD-CV/dPly/PhtD-30 vaccinees had serotype-specific polysaccharide antibody concentrations ≥0.20µg/mL except serotypes 6B (80.8%) and 23F (65.4%), and ≥94.1% had OPA titres of ≥8 except serotypes 1 (51.9%), 5 (38.5%) and 6B (78.0%), within ranges seen in PCV13-vaccinated children. A single dose of PHiD-CV/dPly/PhtD-30 vaccine, administered to Gambian children aged 2-4 y not previously vaccinated with a pneumococcal vaccine, was well-tolerated and immunogenic.

Protein-protein conjugate nanoparticles for malaria antigen delivery and enhanced immunogenicity

PubMed Central

Scaria, Puthupparampil V.; Jones, David S.; Barnafo, Emma; Fischer, Elizabeth R.; Anderson, Charles; MacDonald, Nicholas J.; Lambert, Lynn; Rausch, Kelly M.; Narum, David L.

2017-01-01

Chemical conjugation of polysaccharide to carrier proteins has been a successful strategy to generate potent vaccines against bacterial pathogens. We developed a similar approach for poorly immunogenic malaria protein antigens. Our lead candidates in clinical trials are the malaria transmission blocking vaccine antigens, Pfs25 and Pfs230D1, individually conjugated to the carrier protein Exoprotein A (EPA) through thioether chemistry. These conjugates form nanoparticles that show enhanced immunogenicity compared to unconjugated antigens. In this study, we examined the broad applicability of this technology as a vaccine development platform, by comparing the immunogenicity of conjugates prepared by four different chemistries using different malaria antigens (PfCSP, Pfs25 and Pfs230D1), and carriers such as EPA, TT and CRM197. Several conjugates were synthesized using thioether, amide, ADH and glutaraldehyde chemistries, characterized for average molecular weight and molecular weight distribution, and evaluated in mice for humoral immunogenicity. Conjugates made with the different chemistries, or with different carriers, showed no significant difference in immunogenicity towards the conjugated antigens. Since particle size can influence immunogenicity, we tested conjugates with different average size in the range of 16–73 nm diameter, and observed greater immunogenicity of smaller particles, with significant differences between 16 and 73 nm particles. These results demonstrate the multiple options with respect to carriers and chemistries that are available for protein-protein conjugate vaccine development. PMID:29281708

Emerging human papillomavirus vaccines

PubMed Central

Ma, Barbara; Maraj, Bharat; Tran, Nam Phuong; Knoff, Jayne; Chen, Alexander; Alvarez, Ronald D; Hung, Chien-Fu; Wu, T.-C.

2013-01-01

Introduction Identification of human papillomavirus (HPV) as the etiologic factor of cervical, anogenital, and a subset of head and neck cancers has stimulated the development of preventive and therapeutic HPV vaccines to control HPV-associated malignancies. Excitement has been generated by the commercialization of two preventive L1-based vaccines, which use HPV virus-like particles (VLPs) to generate capsid-specific neutralizing antibodies. However, factors such as high cost and requirement for cold chain have prevented widespread implementation where they are needed most. Areas covered Next generation preventive HPV vaccine candidates have focused on cost-effective stable alternatives and generating broader protection via targeting multivalent L1 VLPs, L2 capsid protein, and chimeric L1/L2 VLPs. Therapeutic HPV vaccine candidates have focused on enhancing T cell-mediated killing of HPV-transformed tumor cells, which constitutively express HPV-encoded proteins, E6 and E7. Several therapeutic HPV vaccines are in clinical trials. Expert opinion Although progress is being made, cost remains an issue inhibiting the use of preventive HPV vaccines in countries that carry the majority of the cervical cancer burden. In addition, progression of therapeutic HPV vaccines through clinical trials may require combination strategies employing different therapeutic modalities. As research in the development of HPV vaccines continues, we may generate effective strategies to control HPV-associated malignancies. PMID:23163511

Elicitation of strong immune responses by a DNA vaccine expressing a secreted form of hepatitis C virus envelope protein E2 in murine and porcine animal models

PubMed Central

Li, Yi-Ping; Kang, Hye Na; Babiuk, Lorne A; Liu, Qiang

2006-01-01

AIM: To characterize the immunogenicity of a hepatitis C virus (HCV) E2 DNA vaccine alone or with a protein vaccine boost in murine and porcine animal models. METHODS: A DNA vaccine expressing a secreted form of HCV E2 protein was constructed and used to vaccinate mice and piglets with or without boosting with a recombinant E2 protein vaccine formulated with CpG ODN and 10% Emulsigen. The immunogenicity of HCV E2 vaccines was analyzed by ELISA for antibody responses, MTT assay for lymphocyte proliferation, ELISPOT for the number of interferon-γ secreting cells, and cytotoxic T lymphocyte assays. RESULTS: Intradermal injection of E2 DNA vaccine induced strong Th1-like immune responses in mice. In piglets, E2 DNA vaccine elicited moderate and more balanced immune responses. A DNA vaccine prime and protein boost vaccination strategy induced significantly higher E2-specific antibody levels and shifted the immune response towards Th2-like ones in piglets. CONCLUSION: A DNA vaccine expressing a secreted form of HCV E2 protein elicited E2-specific immune responses in mice and piglets. Recombinant E2 protein vaccination following DNA immunization significantly increased the antibody response in piglets. These HCV E2 vaccines may represent promising hepatitis C vaccine candidates for further investigations. PMID:17131474

Investigation on Sugar-Protein Connectivity in Salmonella O-Antigen Glycoconjugate Vaccines.

PubMed

De Benedetto, Gianluigi; Salvini, Laura; Gotta, Stefano; Cescutti, Paola; Micoli, Francesca

2018-05-16

Invasive nontyphoidal Salmonella disease, for which licensed vaccines are not available, is a leading cause of bloodstream infections in Africa. The O-antigen portion of lipopolysaccharide is a good target for protective immunity. Covalent conjugation of the O-antigen to a carrier protein increases its immunogenicity and O-antigen based glycoconjugate vaccines are currently under investigation at the preclinical stage. We developed a conjugation chemistry for linking O-antigen to CRM 197 carrier protein, through sequential insertion of adipic acid dihydrazide (ADH) and adipic acid bis( N-hydroxysuccinimide) ester (SIDEA) as linkers, without impacting O-antigen chain epitopes. Here the resulting sugar-protein connectivity has been investigated in detail. The core portion of the lipopolysaccharide was used as a model molecule to prepare CRM 197 conjugates, making structural investigations easier. The first step of reductive amination with ADH involves the terminal 3-deoxy-d- manno-oct-2-ulosonic acid (KDO) residue of the core region. The second reaction step resulted not to be selective, as SIDEA reacted with both ADH and pyrophosphorylethanolamine (PPEtN) of the core region, independently from the pH at which the reaction was performed. Peptide mapping analysis of the deglycosylated core-CRM 197 conjugates confirmed that lysine residues of CRM 197 were linked to SIDEA not only through KDO-ADH but also through PPEtN. This analysis also confirmed that the conjugation chemistry is random on the protein, involving a large number of lysine residues, particularly the surface exposed ones. The method for core-CRM 197 characterization was successfully extended to O-antigen-CRM 197 conjugate, confirming the results obtained with the core. This study not only allowed full characterization of OAg-CRM 197 conjugates, but can be applied to optimize synthesis and characterization of other OAg-based glycoconjugate vaccines. Analytical methods to investigate saccharide-protein

IgG Antibody Responses to Recombinant gp120 Proteins, gp70V1/V2 Scaffolds, and a CyclicV2 Peptide in Thai Phase I/II Vaccine Trials Using Different Vaccine Regimens.

PubMed

Karasavvas, Nicos; Karnasuta, Chitraporn; Savadsuk, Hathairat; Madnote, Sirinan; Inthawong, Dutsadee; Chantakulkij, Somsak; Rittiroongrad, Surawach; Nitayaphan, Sorachai; Pitisuttithum, Punnee; Thongcharoen, Prasert; Siriyanon, Vinai; Andrews, Charla A; Barnett, Susan W; Tartaglia, James; Sinangil, Faruk; Francis, Donald P; Robb, Merlin L; Michael, Nelson L; Ngauy, Viseth; de Souza, Mark S; Paris, Robert M; Excler, Jean-Louis; Kim, Jerome H; O'Connell, Robert J

2015-11-01

RV144 correlates of risk analysis showed that IgG antibodies to gp70V1V2 scaffolds inversely correlated with risk of HIV acquisition. We investigated IgG antibody responses in RV135 and RV132, two ALVAC-HIV prime-boost vaccine trials conducted in Thailand prior to RV144. Both trials used ALVAC-HIV (vCP1521) at 0, 1, 3, and 6 months and HIV-1 gp120MNgD and gp120A244gD in alum (RV135) or gp120SF2 and gp120CM235 in MF59 (RV132) at 3 and 6 months. We assessed ELISA binding antibodies to the envelope proteins (Env) 92TH023, A244gD and MNgD, cyclicV2, and gp70V1V2 CaseA2 (subtype B) and 92TH023 (subtype CRF01_AE), and Env-specific IgG1 and IgG3. Antibody responses to gp120 A244gD, MNgD, and gp70V1V2 92TH023 scaffold were significantly higher in RV135 than in RV132. Antibodies to gp70V1V2 CaseA2 were detected only in RV135 vaccine recipients and IgG1 and IgG3 antibody responses to A244gD were significantly higher in RV135. IgG binding to gp70V1V2 CaseA2 and CRF01_AE scaffolds was higher with the AIDSVAX(®)B/E boost but both trials showed similar rates of antibody decline post-vaccination. MF59 did not result in higher IgG antibody responses compared to alum with the antigens tested. However, notable differences in the structure of the recombinant proteins and dosage used for immunizations may have contributed to the magnitude and specificity of IgG induced by the two trials.

Disa vaccines for Bluetongue: A novel vaccine approach for insect-borne diseases

USDA-ARS?s Scientific Manuscript database

Bluetongue virus (BTV) lacking functional NS3/NS3a protein is named Disabled Infectious Single Animal (DISA) vaccine. The BT DISA vaccine platform is broadly applied by exchange of serotype specific proteins. BT DISA vaccines are produced in standard cell lines in established production facilities, ...

Proteomic analysis of Brucella abortus cell envelope and identification of immunogenic candidate proteins for vaccine development.

PubMed

Connolly, Joseph P; Comerci, Diego; Alefantis, Timothy G; Walz, Alexander; Quan, Marian; Chafin, Ryan; Grewal, Paul; Mujer, Cesar V; Ugalde, Rodolfo A; DelVecchio, Vito G

2006-07-01

Brucella abortus is the etiologic agent of bovine brucellosis and causes a chronic disease in humans known as undulant fever. In livestock the disease is characterized by abortion and sterility. Live, attenuated vaccines such as S19 and RB51 have been used to control the spread of the disease in animals; however, they are considered unsafe for human use and they induce abortion in pregnant cattle. For the development of a safer and equally efficacious vaccine, immunoproteomics was utilized to identify novel candidate proteins from B. abortus cell envelope (CE). A total of 163 proteins were identified using 2-DE with MALDI-TOF MS and LC-MS/MS. Some of the major protein components include outer-membrane protein (OMP) 25, OMP31, Omp2b porin, and 60 kDa chaperonin GroEL. 2-DE Western blot analyses probed with antiserum from bovine and a human patient infected with Brucella identified several new immunogenic proteins such as fumarate reductase flavoprotein subunit, F0F1-type ATP synthase alpha subunit, and cysteine synthase A. The elucidation of the immunome of B. abortus CE identified a number of candidate proteins for developing vaccines against Brucella infection in bovine and humans.

Assessing PCV2 antibodies in field pigs vaccinated with different porcine circovirus 2 vaccines using two commercial ELISA systems.

PubMed

Shin, Min-Kyoung; Yoon, Seung Hyun; Kim, Myung Hwui; Lyoo, Young Soo; Suh, Seung Won; Yoo, Han Sang

2015-01-01

Porcine circovirus type 2 (PCV2) is the primary causative agent for post-weaning, multisystemic, wasting syndrome. Consequently, serologic detection of and vaccination against PCV2 are important for the swine industry. Among several serological tests, the enzyme-linked immunosorbent assay (ELISA) is commonly used to measure anti-PCV2 antibody levels. In the present study, we used two commercial ELISA systems to comparatively evaluate anti-PCV2 antibodies in field pigs treated with three different PCV2 vaccines. Among a total of 517 serum samples, the results of the two ELISAs were fully concordant for 365 positive and 42 negative samples, indicating 78.7% agreement. In addition, the Pearson coefficient (0.636) indicated a moderate correlation between data from the two ELISAs. Results from the farms with pigs vaccinated with the three different PCV2 vaccines demonstrated that most of the vaccinated animals underwent seroconversion. However, the increase and duration of antibody titers varied depending on the vaccine, the presence of maternal antibodies, and the vaccination program. PCV2 serologic status and anti-PCV2 antibody levels of herds from this study could be utilized to determine the best timing for vaccination and assessing vaccination compliance.

Sex and Gender Differences in the Outcomes of Vaccination over the Life Course.

PubMed

Flanagan, Katie L; Fink, Ashley L; Plebanski, Magdalena; Klein, Sabra L

2017-10-06

Both sex (i.e., biological differences) and gender (i.e., social or cultural influences) impact vaccine acceptance, responses, and outcomes. Clinical data illustrate that among children, young adults, and aged individuals, males and females differ in vaccine-induced immune responses, adverse events, and protection. Although males are more likely to receive vaccines, following vaccination, females typically develop higher antibody responses and report more adverse effects of vaccination than do males. Human, nonhuman animal, and in vitro studies reveal numerous immunological, genetic, hormonal, and environmental factors that differ between males and females and contribute to sex- and gender-specific vaccine responses and outcomes. Herein, we address the impact of sex and gender variables that should be considered in preclinical and clinical studies of vaccines.

Immune Efficacy of a Genetically Engineered Vaccine against Lymphocystis Disease Virus: Analysis of Different Immunization Strategies

PubMed Central

Zheng, Fengrong; Sun, Xiuqin; Wu, Xing'an; Liu, Hongzhan; Li, Jiye; Wu, Suqi; Zhang, Jinxing

2011-01-01

Here, we report the construction of a vaccine against lymphocystis disease virus (LCDV) using nucleic acid vaccination technology. A fragment of the major capsid protein encoding gene from an LCDV isolated from China (LCDV-cn) was cloned into an eukaryotic expression vector pEGFP-N2, yielding a recombinant plasmid pEGFP-N2-LCDV-cn0.6 kb. This plasmid was immediately expressed after liposomal transfer into the Japanese flounder embryo cell line. The recombinant plasmid was inoculated into Japanese flounder via two routes (intramuscular injection and hypodermic injection) at three doses (0.1, 5, and 15 μg), and then T-lymphopoiesis in different tissues and antibodies raised against LCDV were evaluated. The results indicated that this recombinant plasmid induced unique humoral or cell-mediated immune responses depending on the inoculation route and conferred immune protection. Furthermore, the humoral immune responses and protective effects were significantly increased at higher vaccine doses via the two injection routes. Plasmid pEGFP-N2-LCDV0.6 kb is therefore a promising vaccine candidate against LCDV in Japanese flounder. PMID:21789044

Trivalent pneumococcal protein recombinant vaccine protects against lethal Streptococcus pneumoniae pneumonia and correlates with phagocytosis by neutrophils during early pathogenesis.

PubMed

Xu, Qingfu; Surendran, Naveen; Verhoeven, David; Klapa, Jessica; Ochs, Martina; Pichichero, Michael E

2015-02-18

Due to the fact that current polysaccharide-based pneumococcal vaccines have limited serotype coverage, protein-based vaccine candidates have been sought for over a decade to replace or complement current vaccines. We previously reported that a trivalent Pneumococcal Protein recombinant Vaccine (PPrV), showed protection against pneumonia and sepsis in an infant murine model. Here we investigated immunological correlates of protection of PPrV in the same model. C57BL/6J infant mice were intramuscularly vaccinated at age 1-3 weeks with 3 doses of PPrV, containing pneumococcal histidine triad protein D (PhtD), pneumococcal choline binding protein A (PcpA), and detoxified pneumolysin mutant PlyD1. 3-4 weeks after last vaccination, serum and lung antibody levels to PPrV components were measured, and mice were intranasally challenged with a lethal dose of Streptococcus pneumoniae (Spn) serotype 6A. Lung Spn bacterial burden, number of neutrophils and alveolar macrophages, phagocytosed Spn by granulocytes, and levels of cytokines and chemokines were determined at 6, 12, 24, and 48h after challenge. PPrV vaccination conferred 83% protection against Spn challenge. Vaccinated mice had significantly elevated serum and lung antibody levels to three PPrV components. In the first stage of pathogenesis of Spn induced pneumonia (6-24h after challenge), vaccinated mice had lower Spn bacterial lung burdens and more phagocytosed Spn in the granulocytes. PPrV vaccination led to lower levels of pro-inflammatory cytokines IL-6, IL-1β, and TFN-α, and other cytokines and chemokines (IL-12, IL-17, IFN-γ, MIP-1b, MIP-2 and KC, and G-CSF), presumably due to a lower lung bacterial burden. Trivalent PPrV vaccination results in increased serum and lung antibody levels to the vaccine components, a reduction in Spn induced lethality, enhanced early clearance of Spn in lungs due to more rapid and thorough phagocytosis of Spn by neutrophils, and correspondingly a reduction in lung inflammation

Virulent and Vaccine Strains of Streptococcus equi ssp. zooepidemicus Have Different Influences on Phagocytosis and Cytokine Secretion of Macrophages.

PubMed

Jie, Peng; Zhe, Ma; Chengwei, Hua; Huixing, Lin; Hui, Zhang; Chengping, Lu; Hongjie, Fan

2017-01-06

Swine streptococcosis is a significant threat to the Chinese pig industry, and Streptococcus equi ssp. zooepidemicus (SEZ) is one of the major pathogens. SEZ ATCC35246 is a classical virulent strain, while SEZ ST171 is a Chinese attenuated vaccine strain. In this study, we employed stable isotope labeling by amino acids in cell culture and liquid chromatography-mass spectrometry (LC-MS) to determine the differential response of macrophages to infection by these two strains. Eighty-seven upregulated proteins and 135 downregulated proteins were identified. The proteomic results were verified by real-time polymerase chain reaction for 10 chosen genes and Western blotting for three proteins. All differentially abundant proteins were analyzed for their Gene Ontology and Kyoto Encyclopedia of Genes and Genomes annotations. Certain downregulated proteins were associated with immunity functions, and the upregulated proteins were related to cytomembrane and cytoskeleton regulation. The phagocytosis rate and cytokine genes transcription in Raw264.7 cells during SEZ ATCC35246 and ST171 infection were detected to confirm the bioinformatics results. These results showed that different effects on macrophage phagocytosis and cytokine expression might explain the different phenotypes of SEZ ATCC35246 and ST171 infection. This research provided clues to the mechanisms of host immunity responses to SEZ ST171and SEZ ATCC35246, which could identify potential therapy and vaccine development targets.

Immunization with Clinical HIV-1 Env Proteins Induces Broad Antibody Dependent Cellular Cytotoxicity-Mediating Antibodies in a Rabbit Vaccination Model.

PubMed

Karlsson, Ingrid; Borggren, Marie; Jensen, Sanne Skov; Heyndrickx, Leo; Stewart-Jones, Guillaume; Scarlatti, Gabriella; Fomsgaard, Anders

2017-11-17

The induction of both neutralizing antibodies and non-neutralizing antibodies with effector functions, for example, antibody-dependent cellular cytotoxicity (ADCC), is desired in the search for effective vaccines against HIV-1. In the pursuit of novel immunogens capable of inducing an efficient antibody response, rabbits were immunized with selected antigens using different prime-boost strategies. We immunized 35 different groups of rabbits with Env antigens from clinical HIV-1 subtypes A and B, including immunization with DNA alone, protein alone, and DNA prime with protein boost. The rabbit sera were screened for ADCC activity using a GranToxiLux-based assay with human peripheral blood mononuclear cells as effector cells and CEM.NKR CCR5 cells coated with HIV-1 envelope as target cells. The groups with the highest ADCC activity were further characterized for cross-reactivity between HIV-1 subtypes. The immunogen inducing the most potent and broadest ADCC response was a trimeric gp140. The ADCC activity was highest against the HIV-1 subtype corresponding to the immunogen. The ADCC activity did not necessarily reflect neutralizing activity in the pseudovirus-TZMbl assay, but there was an overall correlation between the two antiviral activities. We present a rabbit vaccination model and an assay suitable for screening HIV-1 vaccine candidates for the induction of ADCC-mediating antibodies in addition to neutralizing antibodies. The antigens and/or immunization strategies capable of inducing antibodies with ADCC activity did not necessarily induce neutralizing activity and vice versa. Nevertheless, we identified vaccine candidates that were able to concurrently induce both types of responses and that had ADCC activity that was cross-reactive between different subtypes. When searching for an effective vaccine candidate, it is important to evaluate the antibody response using a model and an assay measuring the desired function.

DNA vaccine encoding myristoylated membrane protein (MMP) of rock bream iridovirus (RBIV) induces protective immunity in rock bream (Oplegnathus fasciatus).

PubMed

Jung, Myung-Hwa; Nikapitiya, Chamilani; Jung, Sung-Ju

2018-02-01

Rock bream iridovirus (RBIV) causes severe mass mortalities in rock bream (Oplegnathus fasciatus) in Korea. In this study, we investigated the potential of viral membrane protein to induce antiviral status protecting rock bream against RBIV infection. We found that fish administered with ORF008L (myristoylated membrane protein, MMP) vaccine exhibited significantly higher levels of survival compared to ORF007L (major capsid protein, MCP). Moreover, ORF008L-based DNA vaccinated fish showed significant protection at 4 and 8 weeks post vaccination (wpv) than non-vaccinated fish after infected with RBIV (6.7 × 10 5 ) at 23 °C, with relative percent survival (RPS) of 73.36% and 46.72%, respectively. All of the survivors from the first RBIV infection were strongly protected (100% RPS) from re-infected with RBIV (1.1 × 10 7 ) at 100 dpi. In addition, the MMP (ORF008L)-based DNA vaccine significantly induced the gene expression of TLR3 (14.2-fold), MyD88 (11.6-fold), Mx (84.7-fold), ISG15 (8.7-fold), PKR (25.6-fold), MHC class I (13.3-fold), Fas (6.7-fold), Fas ligand (6.7-fold), caspase9 (17.0-fold) and caspase3 (15.3-fold) at 7 days post vaccination in the muscle (vaccine injection site). Our results showed the induction of immune responses and suggest the possibility of developing preventive measures against RBIV using myristoylated membrane protein-based DNA vaccine. Copyright © 2018 Elsevier Ltd. All rights reserved.

Vaccine-Mediated Activation of Human TLR4 Is Affected by Modulation of Culture Conditions during Whole-Cell Pertussis Vaccine Preparation

PubMed Central

Hoonakker, Marieke E.; Verhagen, Lisa M.; Pupo, Elder; de Haan, Alex; Metz, Bernard; Hendriksen, Coenraad F. M.; Han, Wanda G. H.; Sloots, Arjen

2016-01-01

The potency of whole-cell pertussis (wP) vaccines is still determined by an intracerebral mouse protection test. To allow development of suitable in vitro alternatives to this test, insight into relevant parameters to monitor the consistency of vaccine quality is essential. To this end, a panel of experimental wP vaccines of varying quality was prepared by sulfate-mediated suppression of the BvgASR master virulence regulatory system of Bordetella pertussis during cultivation. This system regulates the transcription of a range of virulence proteins, many of which are considered important for the induction of effective host immunity. The protein compositions and in vivo potencies of the vaccines were BvgASR dependent, with the vaccine containing the highest amount of virulence proteins having the highest in vivo potency. Here, the capacities of these vaccines to stimulate human Toll-like receptors (hTLR) 2 and 4 and the role these receptors play in wP vaccine-mediated activation of antigen-presenting cells in vitro were studied. Prolonged BvgASR suppression was associated with a decreased capacity of vaccines to activate hTLR4. In contrast, no significant differences in hTLR2 activation were observed. Similarly, vaccine-induced activation of MonoMac-6 and monocyte-derived dendritic cells was strongest with the highest potency vaccine. Blocking of TLR2 and TLR4 showed that differences in antigen-presenting cell activation could be largely attributed to vaccine-dependent variation in hTLR4 signalling. Interestingly, this BvgASR-dependent decrease in hTLR4 activation coincided with a reduction in GlcN-modified lipopolysaccharides in these vaccines. Accordingly, expression of the lgmA-C genes, required for this glucosamine modification, was significantly reduced in bacteria exposed to sulfate. Together, these findings demonstrate that the BvgASR status of bacteria during wP vaccine preparation is critical for their hTLR4 activation capacity and suggest that including

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

Vaccination against group B streptococcus.

PubMed

Heath, Paul T; Feldman, Robert G

2005-04-01

Streptococcus agalactiae (Group B streptococcus) is an important cause of disease in infants, pregnant women, the elderly and in immunosuppressed adults. An effective vaccine is likely to prevent the majority of infant disease (both early and late onset), as well as Group B streptococcus-related stillbirths and prematurity, to avoid the current real and theoretical limitations of intrapartum antibiotic prophylaxis, and to be cost effective. The optimal time to administer such a vaccine would be in the third trimester of pregnancy. The main limitations on the production of a Group B streptococcus vaccine are not technical or scientific, but regulatory and legal. A number of candidates including capsular conjugate vaccines using traditional carrier proteins such as tetanus toxoid and mutant diphtheria toxin CRM197, as well as Group B streptococcus-specific proteins such as C5a peptidase, protein vaccines using one or more Group B streptococcus surface proteins and mucosal vaccines, have the potential to be successful vaccines. The capsular conjugate vaccines using tetanus and CRM197 carrier proteins are the most advanced candidates, having already completed Phase II human studies including use in the target population of pregnant women (tetanus toxoid conjugate), however, no definitive protein conjugates have yet been trialed. However, unless the regulatory environment is changed specifically to allow the development of a Group B streptococcus vaccine, it is unlikely that one will ever reach the market.

Vaccines. An Ebola whole-virus vaccine is protective in nonhuman primates.

PubMed

Marzi, Andrea; Halfmann, Peter; Hill-Batorski, Lindsay; Feldmann, Friederike; Shupert, W Lesley; Neumann, Gabriele; Feldmann, Heinz; Kawaoka, Yoshihiro

2015-04-24

Zaire ebolavirus is the causative agent of the current outbreak of hemorrhagic fever disease in West Africa. Previously, we showed that a whole Ebola virus (EBOV) vaccine based on a replication-defective EBOV (EBOVΔVP30) protects immunized mice and guinea pigs against lethal challenge with rodent-adapted EBOV. Here, we demonstrate that EBOVΔVP30 protects nonhuman primates against lethal infection with EBOV. Although EBOVΔVP30 is replication-incompetent, we additionally inactivated the vaccine with hydrogen peroxide; the chemically inactivated vaccine remained antigenic and protective in nonhuman primates. EBOVΔVP30 thus represents a safe, efficacious, whole-EBOV vaccine candidate that differs from other EBOV vaccine platforms in that it presents all viral proteins and the viral RNA to the host immune system, which might contribute to protective immune responses. Copyright © 2015, American Association for the Advancement of Science.

Preparation and characterization of protein-loaded poly(epsilon-caprolactone) microparticles for oral vaccine delivery.

PubMed

Benoit, M A; Baras, B; Gillard, J

1999-07-05

This paper describes the conditions of preparation of poly(epsilon-caprolactone) (PCL) microparticles with a mean size between 5 and 10 microm, obtained by a double emulsion-solvent evaporation technique, suitable for oral vaccine delivery. Bovine serum albumin (BSA) was used as water-soluble model antigen for encapsulation. Different parameters influencing the microparticle size, the BSA loading and entrapment efficiency were investigated. Spherical, smooth and homogeneously distributed microparticles were produced with a BSA loading and entrapment efficiency reaching, respectively, 5% (w/w) and 30%. Polyacrylamide gel electrophoresis (PAGE) and isoelectric focusing (IEF) analyses of BSA released from these particles confirmed that the entrapped protein seemed to remain unaltered by the protein encapsulation process. Copyright.

The March Toward Malaria Vaccines.

PubMed

Hoffman, Stephen L; Vekemans, Johan; Richie, Thomas L; Duffy, Patrick E

2015-12-01

In 2013 there were an estimated 584,000 deaths and 198 million clinical illnesses due to malaria, the majority in sub-Saharan Africa. Vaccines would be the ideal addition to the existing armamentarium of anti-malaria tools. However, malaria is caused by parasites, and parasites are much more complex in terms of their biology than the viruses and bacteria for which we have vaccines, passing through multiple stages of development in the human host, each stage expressing hundreds of unique antigens. This complexity makes it more difficult to develop a vaccine for parasites than for viruses and bacteria, since an immune response targeting one stage may not offer protection against a later stage, because different antigens are the targets of protective immunity at different stages. Furthermore, depending on the life cycle stage and whether the parasite is extra- or intra-cellular, antibody and/or cellular immune responses provide protection. It is thus not surprising that there is no vaccine on the market for prevention of malaria, or any human parasitic infection. In fact, no vaccine for any disease with this breadth of targets and immune responses exists. In this limited review, we focus on four approaches to malaria vaccines, (1) a recombinant protein with adjuvant vaccine aimed at Plasmodium falciparum (Pf) pre-erythrocytic stages of the parasite cycle (RTS,S/AS01), (2) whole sporozoite vaccines aimed at Pf pre-erythrocytic stages (PfSPZ Vaccine and PfSPZ-CVac), (3) prime boost vaccines that include recombinant DNA, viruses and bacteria, and protein with adjuvant aimed primarily at Pf pre-erythrocytic, but also asexual erythrocytic stages, and (4) recombinant protein with adjuvant vaccines aimed at Pf and Plasmodium vivax sexual erythrocytic and mosquito stages. We recognize that we are not covering all approaches to malaria vaccine development, or most of the critically important work on development of vaccines against P. vivax, the second most important cause of

The March Toward Malaria Vaccines

PubMed Central

Hoffman, Stephen L.; Vekemans, Johan; Richie, Thomas L.; Duffy, Patrick E.

2016-01-01

In 2013 there were an estimated 584,000 deaths and 198 million clinical illnesses due to malaria, the majority in sub-Saharan Africa. Vaccines would be the ideal addition to the existing armamentarium of anti-malaria tools. However, malaria is caused by parasites, and parasites are much more complex in terms of their biology than the viruses and bacteria for which we have vaccines, passing through multiple stages of development in the human host, each stage expressing hundreds of unique antigens. This complexity makes it more difficult to develop a vaccine for parasites than for viruses and bacteria, since an immune response targeting one stage may not offer protection against a later stage, because different antigens are the targets of protective immunity at different stages. Furthermore, depending on the life cycle stage and whether the parasite is extra- or intra-cellular, antibody and/or cellular immune responses provide protection. It is thus not surprising that there is no vaccine on the market for prevention of malaria, or any human parasitic infection. In fact, no vaccine for any disease with this breadth of targets and immune responses exists. In this limited review, we focus on four approaches to malaria vaccines, (1) a recombinant protein with adjuvant vaccine aimed at Plasmodium falciparum (Pf) pre-erythrocytic stages of the parasite cycle (RTS,S/AS01), (2) whole sporozoite vaccines aimed at Pf pre-erythrocytic stages (PfSPZ Vaccine and PfSPZ-CVac), (3) prime boost vaccines that include recombinant DNA, viruses and bacteria, and protein with adjuvant aimed primarily at Pf pre-erythrocytic, but also asexual erythrocytic stages, and (4) recombinant protein with adjuvant vaccines aimed at Pf and Plasmodium vivax sexual erythrocytic and mosquito stages. We recognize that we are not covering all approaches to malaria vaccine development, or most of the critically important work on development of vaccines against P. vivax, the second most important cause of

The march toward malaria vaccines

PubMed Central

Hoffman, Stephen L.; Vekemans, Johan; Richie, Thomas L.; Duffy, Patrick E.

2016-01-01

In 2013 there were an estimated 584,000 deaths and 198 million clinical illnesses due to malaria, the majority in sub-Saharan Africa. Vaccines would be the ideal addition to the existing armamentarium of anti-malaria tools. However, malaria is caused by parasites, and parasites are much more complex in terms of their biology than the viruses and bacteria for which we have vaccines, passing through multiple stages of development in the human host, each stage expressing hundreds of unique antigens. This complexity makes it more difficult to develop a vaccine for parasites than for viruses and bacteria, since an immune response targeting one stage may not offer protection against a later stage, because different antigens are the targets of protective immunity at different stages. Furthermore, depending on the life cycle stage and whether the parasite is extra- or intra-cellular, antibody and/or cellular immune responses provide protection. It is thus not surprising that there is no vaccine on the market for prevention of malaria, or any human parasitic infection. In fact, no vaccine for any disease with this breadth of targets and immune responses exists. In this limited review, we focus on four approaches to malaria vaccines, (1) a recombinant protein with adjuvant vaccine aimed at Plasmodium falciparum (Pf) pre-erythrocytic stages of the parasite cycle (RTS,S/AS01), (2) whole sporozoite vaccines aimed at Pf pre-erythrocytic stages (PfSPZ Vaccine and PfSPZ-CVac), (3) prime boost vaccines that include recombinant DNA, viruses and bacteria, and protein with adjuvant aimed primarily at Pf pre-erythrocytic, but also asexual erythrocytic stages, and (4) recombinant protein with adjuvant vaccines aimed at Pf and Plasmodium vivax sexual erythrocytic and mosquito stages. We recognize that we are not covering all approaches to malaria vaccine development, or most of the critically important work on development of vaccines against P. vivax, the second most important cause of

The march toward malaria vaccines.

PubMed

Hoffman, Stephen L; Vekemans, Johan; Richie, Thomas L; Duffy, Patrick E

2015-11-27

In 2013 there were an estimated 584,000 deaths and 198 million clinical illnesses due to malaria, the majority in sub-Saharan Africa. Vaccines would be the ideal addition to the existing armamentarium of anti-malaria tools. However, malaria is caused by parasites, and parasites are much more complex in terms of their biology than the viruses and bacteria for which we have vaccines, passing through multiple stages of development in the human host, each stage expressing hundreds of unique antigens. This complexity makes it more difficult to develop a vaccine for parasites than for viruses and bacteria, since an immune response targeting one stage may not offer protection against a later stage, because different antigens are the targets of protective immunity at different stages. Furthermore, depending on the life cycle stage and whether the parasite is extra- or intra-cellular, antibody and/or cellular immune responses provide protection. It is thus not surprising that there is no vaccine on the market for prevention of malaria, or any human parasitic infection. In fact, no vaccine for any disease with this breadth of targets and immune responses exists. In this limited review, we focus on four approaches to malaria vaccines, (1) a recombinant protein with adjuvant vaccine aimed at Plasmodium falciparum (Pf) pre-erythrocytic stages of the parasite cycle (RTS,S/AS01), (2) whole sporozoite vaccines aimed at Pf pre-erythrocytic stages (PfSPZ Vaccine and PfSPZ-CVac), (3) prime boost vaccines that include recombinant DNA, viruses and bacteria, and protein with adjuvant aimed primarily at Pf pre-erythrocytic, but also asexual erythrocytic stages, and (4) recombinant protein with adjuvant vaccines aimed at Pf and Plasmodium vivax sexual erythrocytic and mosquito stages. We recognize that we are not covering all approaches to malaria vaccine development, or most of the critically important work on development of vaccines against P. vivax, the second most important cause of

Immunogenicity and safety of the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) co-administered with DTPa vaccine in Japanese children: A randomized, controlled study.

PubMed

Iwata, Satoshi; Kawamura, Naohisa; Kuroki, Haruo; Tokoeda, Yasunobu; Miyazu, Mitsunobu; Iwai, Asayuki; Oishi, Tomohiro; Sato, Tomohide; Suyama, Akari; François, Nancy; Shafi, Fakrudeen; Ruiz-Guiñazú, Javier; Borys, Dorota

2015-01-01

This phase III, randomized, open-label, multicenter study (NCT01027845) conducted in Japan assessed the immunogenicity, safety, and reactogenicity of 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV, given intramuscularly) co-administered with diphtheria-tetanus-acellular pertussis vaccine (DTPa, given subcutaneously). Infants (N=360 ) were randomized (2:1) to receive either PHiD-CV and DTPa (PHiD-CV group) or DTPa alone (control group) as 3-dose primary vaccination (3-4-5 months of age) and booster vaccination (17-19 months of age). Immune responses were measured before and one month after primary/booster vaccination and adverse events (AEs) were recorded. Post-primary immune responses were non-inferior to those in pivotal/efficacy European or Latin American pneumococcal protein D-conjugate vaccine studies. For each PHiD-CV serotype, at least 92.6% of infants post-primary vaccination and at least 97.7% of children post-booster had pneumococcal antibody concentrations ≥0.2 μg/ml, and at least 95.4% post-primary and at least 98.1% post-booster had opsonophagocytic activity (OPA) titers ≥8 . Geometric mean antibody concentrations and OPA titers (except OPA titer for 6B) were higher post-booster than post-priming for each serotype. All PHiD-CV-vaccinated children had anti-protein D antibody concentrations ≥100 EL.U/ml one month post-primary/booster vaccination and all were seroprotected/seropositive against each DTPa antigen. Redness and irritability were the most common solicited AEs in both groups. Incidences of unsolicited AEs were comparable between groups. Serious AEs were reported for 47 children (28 in PHiD-CV group); none were assessed as vaccine-related. In conclusion, PHiD-CV induced robust immune responses and was well tolerated when co-administered with DTPa in a 3-dose priming plus booster regimen to Japanese children.

Potential To Streamline Heterologous DNA Prime and NYVAC/Protein Boost HIV Vaccine Regimens in Rhesus Macaques by Employing Improved Antigens

PubMed Central

Asbach, Benedikt; Kliche, Alexander; Köstler, Josef; Perdiguero, Beatriz; Esteban, Mariano; Jacobs, Bertram L.; Montefiori, David C.; LaBranche, Celia C.; Yates, Nicole L.; Tomaras, Georgia D.; Ferrari, Guido; Foulds, Kathryn E.; Roederer, Mario; Landucci, Gary; Forthal, Donald N.; Seaman, Michael S.; Hawkins, Natalie; Self, Steven G.; Sato, Alicia; Gottardo, Raphael; Phogat, Sanjay; Tartaglia, James; Barnett, Susan W.; Burke, Brian; Cristillo, Anthony D.; Weiss, Deborah E.; Francis, Jesse; Galmin, Lindsey; Ding, Song; Heeney, Jonathan L.; Pantaleo, Giuseppe

2016-01-01

ABSTRACT In a follow-up to the modest efficacy observed in the RV144 trial, researchers in the HIV vaccine field seek to substantiate and extend the results by evaluating other poxvirus vectors and combinations with DNA and protein vaccines. Earlier clinical trials (EuroVacc trials 01 to 03) evaluated the immunogenicity of HIV-1 clade C GagPolNef and gp120 antigens delivered via the poxviral vector NYVAC. These showed that a vaccination regimen including DNA-C priming prior to a NYVAC-C boost considerably enhanced vaccine-elicited immune responses compared to those with NYVAC-C alone. Moreover, responses were improved by using three as opposed to two DNA-C primes. In the present study, we assessed in nonhuman primates whether such vaccination regimens can be streamlined further by using fewer and accelerated immunizations and employing a novel generation of improved DNA-C and NYVAC-C vaccine candidates designed for higher expression levels and more balanced immune responses. Three different DNA-C prime/NYVAC-C+ protein boost vaccination regimens were tested in rhesus macaques. All regimens elicited vigorous and well-balanced CD8+ and CD4+ T cell responses that were broad and polyfunctional. Very high IgG binding titers, substantial antibody-dependent cellular cytotoxicity (ADCC), and modest antibody-dependent cell-mediated virus inhibition (ADCVI), but very low neutralization activity, were measured after the final immunizations. Overall, immune responses elicited in all three groups were very similar and of greater magnitude, breadth, and quality than those of earlier EuroVacc vaccines. In conclusion, these findings indicate that vaccination schemes can be simplified by using improved antigens and regimens. This may offer a more practical and affordable means to elicit potentially protective immune responses upon vaccination, especially in resource-constrained settings. IMPORTANCE Within the EuroVacc clinical trials, we previously assessed the immunogenicity of

Protection of Mice from Fatal Measles Encephalitis by Vaccination with Vaccinia Virus Recombinants Encoding Either the Hemagglutinin or the Fusion Protein

NASA Astrophysics Data System (ADS)

Drillien, Robert; Spehner, Daniele; Kirn, Andre; Giraudon, Pascale; Buckland, Robin; Wild, Fabian; Lecocq, Jean-Pierre

1988-02-01

Vaccinia virus recombinants encoding the hemagglutinin or fusion protein of measles virus have been constructed. Infection of cell cultures with the recombinants led to the synthesis of authentic measles proteins as judged by their electrophoretic mobility, recognition by antibodies, glycosylation, proteolytic cleavage, and presentation on the cell surface. Mice vaccinated with a single dose of the recombinant encoding the hemagglutinin protein developed antibodies capable of both inhibiting hemagglutination activity and neutralizing measles virus, whereas animals vaccinated with the recombinant encoding the fusion protein developed measles neutralizing antibodies. Mice vaccinated with either of the recombinants resisted a normally lethal intracerebral inoculation of a cell-associated measles virus subacute sclerosing panencephalitis strain.

First characterization of immunogenic conjugates of Vi negative Salmonella Typhi O-specific polysaccharides with rEPA protein for vaccine development.

PubMed

Salman, M; St Michael, F; Ali, A; Jabbar, A; Cairns, C; Hayes, A C; Rahman, M; Iqbal, M; Haque, A; Cox, A D

2017-11-01

Efficacious typhoid vaccines for young children will significantly reduce the disease burden in developing world. The Vi polysaccharide based conjugate vaccines (Vi-rEPA) against Salmonella Typhi Vi positive strains has shown high efficacy but may be ineffective against Vi negative S. Typhi. In this study, for the first time, we report the synthesis and evaluation of polysaccharide-protein conjugates of Vi negative S. Typhi as potential vaccine candidates. Four different conjugates were synthesized using recombinant exoprotein A of Pseudomonas aeruginosa (rEPA) and human serum albumin (HSA) as the carrier proteins, using either direct reductive amination or an intermediate linker molecule, adipic acid dihydrazide (ADH). Upon injection into mice, a significantly higher antibody titer was observed in mice administrated with conjugate-1 (OSP-HSA) (P=0.0001) and conjugate 2 (OSP-rEPA) (P≤0.0001) as compared to OSP alone. In contrast, the antibody titer elicited by conjugate 3 (OSP ADH -HSA) and conjugate 4 (OSP ADH -rEPA) were insignificant (P=0.1684 and P=0.3794, respectively). We conclude that reductive amination is the superior method to prepare the S. Typhi OSP glycoconjugate. Moreover, rEPA was a better carrier protein than HSA. Thus OSP-rEPA conjugate seems to be efficacious typhoid vaccines candidate, it may be evaluated further and recommended for the clinical trials. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Efficient induction of anti-tumor immunity by a TAT-CEA fusion protein vaccine with poly(I:C) in a murine colorectal tumor model.

PubMed

Park, Jung-Sun; Kim, Hye-Sung; Park, Hye-Mi; Kim, Chang-Hyun; Kim, Tai-Gyu

2011-11-03

Protein vaccines may be a useful strategy for cancer immunotherapy because recombinant tumor antigen proteins can be produced on a large scale at relatively low cost and have been shown to be safe for clinical application. However, protein vaccines have historically exhibited poor immunogenicity; thus, an improved strategy is needed for successful induction of immune responses. TAT peptide is a protein transduction domain composed of an 11-amino acid peptide (TAT(47-57): YGRKKRRQRRR). The positive charge of this peptide allows protein antigen fused with it to improve cell penetration. Poly(I:C) is a synthetic double-stranded RNA that is negatively charged and favors interaction with the cationic TAT peptide. Poly(I:C) has been reported on adjuvant role in tumor vaccine through promotion of immune responses. Therefore, we demonstrated that vaccine with a mixture of TAT-CEA fusion protein and poly(I:C) can induce anti-tumor immunity in a murine colorectal tumor model. Splenocytes from mice vaccinated with a mixture of TAT-CEA fusion protein and poly(I:C) effectively induced CEA-specific IFN-γ-producing T cells and showed cytotoxic activity specific for MC-38-cea2 tumor cells expressing CEA. Vaccine with a mixture of TAT-CEA fusion protein and poly(I:C) delayed tumor growth in MC-38-cea-2 tumor-bearing mice. Depletion of CD8(+) T cells and NK cells reversed the inhibition of tumor growth in an MC-38-cea2-bearing mice, indicating that CD8(+) T cells and NK cells are responsible for anti-tumor immunity by vaccine with a mixture of TAT-CEA fusion protein and poly(I:C). Taken together, these results suggest that poly(I:C) could be used as a potent adjuvant to induce the anti-tumor immunity of a TAT-CEA fusion protein vaccine in a murine colorectal tumor model. Copyright © 2011 Elsevier Ltd. All rights reserved.

Heat-shock proteins as dendritic cell-targeting vaccines – getting warmer

PubMed Central

McNulty, Shaun; Colaco, Camilo A; Blandford, Lucy E; Bailey, Christopher R; Baschieri, Selene; Todryk, Stephen

2013-01-01

Heat-shock proteins (hsp) provide a natural link between innate and adaptive immune responses by combining the ideal properties of antigen carriage (chaperoning), targeting and activation of antigen-presenting cells (APC), including dendritic cells (DC). Targeting is achieved through binding of hsp to distinct cell surface receptors and is followed by antigen internalization, processing and presentation. An improved understanding of the interaction of hsp with DC has driven the development of numerous hsp-containing vaccines, designed to deliver antigens directly to DC. Studies in mice have shown that for cancers, such vaccines generate impressive immune responses and protection from tumour challenge. However, translation to human use, as for many experimental immunotherapies, has been slow partly because of the need to perform trials in patients with advanced cancers, where demonstration of efficacy is challenging. Recently, the properties of hsp have been used for development of prophylactic vaccines against infectious diseases including tuberculosis and meningitis. These hsp-based vaccines, in the form of pathogen-derived hsp–antigen complexes, or recombinant hsp combined with selected antigens in vitro, offer an innovative approach against challenging diseases where broad antigen coverage is critical. PMID:23551234

Traditional and New Influenza Vaccines

PubMed Central

Wong, Sook-San

2013-01-01

SUMMARY The challenges in successful vaccination against influenza using conventional approaches lie in their variable efficacy in different age populations, the antigenic variability of the circulating virus, and the production and manufacturing limitations to ensure safe, timely, and adequate supply of vaccine. The conventional influenza vaccine platform is based on stimulating immunity against the major neutralizing antibody target, hemagglutinin (HA), by virus attenuation or inactivation. Improvements to this conventional system have focused primarily on improving production and immunogenicity. Cell culture, reverse genetics, and baculovirus expression technology allow for safe and scalable production, while adjuvants, dose variation, and alternate routes of delivery aim to improve vaccine immunogenicity. Fundamentally different approaches that are currently under development hope to signal new generations of influenza vaccines. Such approaches target nonvariable regions of antigenic proteins, with the idea of stimulating cross-protective antibodies and thus creating a “universal” influenza vaccine. While such approaches have obvious benefits, there are many hurdles yet to clear. Here, we discuss the process and challenges of the current influenza vaccine platform as well as new approaches that are being investigated based on the same antigenic target and newer technologies based on different antigenic targets. PMID:23824369

Vaccination with Recombinant Cryptococcus Proteins in Glucan Particles Protects Mice against Cryptococcosis in a Manner Dependent upon Mouse Strain and Cryptococcal Species

PubMed Central

Lee, Chrono K.; Huang, Haibin; Hester, Maureen M.; Liu, Jianhua; Luckie, Bridget A.; Torres Santana, Melanie A.; Mirza, Zeynep; Khoshkenar, Payam; Abraham, Ambily; Shen, Zu T.; Lodge, Jennifer K.; Akalin, Ali; Homan, Jane; Ostroff, Gary R.

2017-01-01

ABSTRACT Development of a vaccine to protect against cryptococcosis is a priority given the enormous global burden of disease in at-risk individuals. Using glucan particles (GPs) as a delivery system, we previously demonstrated that mice vaccinated with crude Cryptococcus-derived alkaline extracts were protected against lethal challenge with Cryptococcus neoformans and Cryptococcus gattii. The goal of the present study was to identify protective protein antigens that could be used in a subunit vaccine. Using biased and unbiased approaches, six candidate antigens (Cda1, Cda2, Cda3, Fpd1, MP88, and Sod1) were selected, recombinantly expressed in Escherichia coli, purified, and loaded into GPs. Three mouse strains (C57BL/6, BALB/c, and DR4) were then vaccinated with the antigen-laden GPs, following which they received a pulmonary challenge with virulent C. neoformans and C. gattii strains. Four candidate vaccines (GP-Cda1, GP-Cda2, GP-Cda3, and GP-Sod1) afforded a significant survival advantage in at least one mouse model; some vaccine combinations provided added protection over that seen with either antigen alone. Vaccine-mediated protection against C. neoformans did not necessarily predict protection against C. gattii. Vaccinated mice developed pulmonary inflammatory responses that effectively contained the infection; many surviving mice developed sterilizing immunity. Predicted T helper cell epitopes differed between mouse strains and in the degree to which they matched epitopes predicted in humans. Thus, we have discovered cryptococcal proteins that make promising candidate vaccine antigens. Protection varied depending on the mouse strain and cryptococcal species, suggesting that a successful human subunit vaccine will need to contain multiple antigens, including ones that are species specific. PMID:29184017

Parents who refuse or delay HPV vaccine: Differences in vaccination behavior, beliefs, and clinical communication preferences

PubMed Central

Gilkey, Melissa B.; Calo, William A.; Marciniak, Macary W.

2017-01-01

ABSTRACT Background: We sought to estimate the national prevalence of HPV vaccine refusal and delay in a nationally-representative sample of parents of adolescents. We also compared parents who refused versus delayed HPV vaccine in terms of their vaccination beliefs and clinical communication preferences. Methods: In 2014 to 2015, we conducted an online survey of 1,484 US parents who reported on an 11- to 17-year-old child in their household. We used weighted multinomial logistic regression to assess correlates of HPV vaccine refusal and delay. Results: Overall, 28% of parents reported that they had ever “refused or decided not to get” HPV vaccine for their child, and an additional 8% of parents reported that they had “delayed or put off getting” HPV vaccine. Compared to no refusal/delay, refusal was associated with lower confidence in adolescent vaccination (relative risk ratio [RRR] = 0.66, 95% confidence interval [CI], 0.48–0.91), lower perceived HPV vaccine effectiveness (RRR = 0.68, 95% CI, 0.50–0.91), and higher perceived harms (RRR = 3.49, 95% CI, 2.65–4.60). In contrast, delay was associated with needing more information (RRR = 1.76, 95% CI, 1.08–2.85). Most parents rated physicians and information sheets as helpful for making decisions about HPV vaccination, although parents who reported refusal endorsed these resources less often. Conclusions: Our findings suggest that HPV vaccine refusal is common among parents of adolescents and may have increased relative to previous estimates. Because the vaccination beliefs and communication preferences of parents who refuse appear to differ from those who delay, targeted communication strategies may be needed to effectively address HPV vaccine hesitancy. PMID:27763818

Issues and Challenges in the Development of Pneumococcal Protein Vaccines: A Two Day International Symposium

PubMed Central

Ginsburg, Amy S.; Nahm, Moon H.; Khambaty, Farukh M.; Alderson, Mark R.

2013-01-01

In view of the increasing licensure and use of pneumococcal conjugate vaccines (PCVs), their relatively high cost, and growing issues with serotype emergence, there is a need to re-evaluate the role of pneumococcal protein vaccines (PPVs) and pathways to their licensure. This paper summarizes the discussion and viewpoints from an expert meeting regarding the development of PPVs. A wide spectrum of pneumococcal vaccine researchers, developers, and regulators met to review the state of PPVs, identify research and development needs, and provide consensus opinions to support the introduction of new PPVs where possible. They also discussed clinical and regulatory aspects pertinent to these vaccines and generated a series of recommendations for moving the field forward. PMID:22380821

The effects of increasing dietary levels of soy protein concentrate (SPC) on the immune responses and disease resistance (furunculosis) of vaccinated and non-vaccinated Atlantic salmon (Salmo salar L.) parr.

PubMed

Metochis, Christoforos P; Spanos, I; Auchinachie, N; Crampton, V O; Bell, J G; Adams, A; Thompson, K D

2016-12-01

Juvenile salmon, with an initial weight of 9 g, were fed three experimental diets, formulated to replace 35 (SPC35), 58 (SPC58) and 80 (SPC80) of high quality fishmeal (FM) with soy protein concentrate (SPC) in quadruplicate tanks. Higher dietary SPC inclusion was combined with increased supplementation of methionine, lysine, threonine and phosphorus. The experiment was carried out for 177 days. On day 92 salmon in each tank were bulk weighed. Post weighing eighty salmon from each tank were redistributed in two sets of 12 tanks. Salmon from the first set of tanks were vaccinated, while the second group was injected with phosphate buffer saline (PBS). Salmon were sampled on day 92 (pre-vaccination), day 94 (2 days post vaccination [dpv]/PBS injection [dpPBSinj]) and day 154 (62 dpv/dpPBSinj) of the trial for the assessment of their immune responses, prior to the performance of salmon bulk weights for each tank. On day 154, fish from each tank were again bulk weighed and then seventeen salmon per tank were redistributed in two sets of twelve tanks and intra-peritoneally infected with Aeromonas salmonicida. At Day 154, SPC80 demonstrated lower performance (weight gain, specific growth rate and thermal growth coefficient and feed conversion ratio) compared to SPC35 salmon. Reduced classical and total complement activities for salmon fed diets with over 58% of protein from SPC, were demonstrated prior to vaccination. Reduced alternative complement activity was detected for both SPC58 and SPC80 salmon at 2 dpv and for the SPC80 group at 62 dpv. Total and classical complement activities demonstrated no differences among the dietary groups after vaccination. Numerical increases in classical complement activity were apparent upon increased dietary SPC levels. Increased phagocytic activity (% phagocytosis and phagocytic index) was exhibited for the SPC58 group compared to SPC35 salmon at 62 dpPBSinj. No differences in serum lysozyme activity, total IgM, specific antibodies

Purification, stability, and immunogenicity analyses of five bluetongue virus proteins for use in development of a subunit vaccine that allows differentiation of infected from vaccinated animals.

PubMed

Anderson, Jenna; Bréard, Emmanuel; Lövgren Bengtsson, Karin; Grönvik, Kjell-Olov; Zientara, Stéphan; Valarcher, Jean-Francois; Hägglund, Sara

2014-03-01

Bluetongue virus (BTV) causes bluetongue disease, a vector-borne disease of ruminants. The recent northerly spread of BTV serotype 8 in Europe resulted in outbreaks characterized by clinical signs in cattle, including unusual teratogenic effects. Vaccination has been shown to be crucial for controlling the spread of vector-borne diseases such as BTV. With the aim of developing a novel subunit vaccine targeting BTV-8 that allows differentiation of infected from vaccinated animals, five His-tagged recombinant proteins, VP2 and VP5 of BTV-8 and NS1, NS2, and NS3 of BTV-2, were expressed in baculovirus or Escherichia coli expression systems for further study. Optimized purification protocols were determined for VP2, NS1, NS2, and NS3, which remained stable for detection for at least 560 to 610 days of storage at +4°C or -80°C, and Western blotting using sera from vaccinated or experimentally infected cattle indicated that VP2 and NS2 were recognized by BTV-specific antibodies. To characterize murine immune responses to the four proteins, mice were subcutaneously immunized twice at a 4-week interval with one of three protein combinations plus immunostimulating complex ISCOM-Matrix adjuvant or with ISCOM-Matrix alone (n = 6 per group). Significantly higher serum IgG antibody titers specific for VP2 and NS2 were detected in immunized mice than were detected in controls. VP2, NS1, and NS2 but not NS3 induced specific lymphocyte proliferative responses upon restimulation of spleen cells from immunized mice. The data suggest that these recombinant purified proteins, VP2, NS1, and NS2, could be an important part of a novel vaccine design against BTV-8.

A subunit vaccine against the adenovirus egg-drop syndrome using part of its fiber protein.

PubMed

Fingerut, E; Gutter, B; Gallili, G; Michael, A; Pitcovski, J

2003-06-20

In this study, the effectiveness of antibodies against the hexon, fiber or a fiber fragment of an avian adenovirus egg-drop syndrome (EDS), in neutralizing the virus was tested. The fiber protein is responsible for binding the virus to the target cell. The fiber fragment knob-s comprises the carboxy-terminal knob domain and 34 amino acids of the immediately adjacent shaft domain of the adenovirus fiber protein. The hexon, fiber capsid protein and knob-s were produced in E. coli and injected into chickens. Antibodies that were produced against the whole fiber protein showed some hemagglutination inhibition (HI) activity. Antibodies produced against the knob-s protein showed HI activity and serum neutralization (SN) activity similar to the positive control-whole virus vaccine. We assume that production of only part of the fiber enables the protein produced in E. coli to fold correctly. Antibodies produced against the hexon protein showed no SN activity. In summary, knob-s induced SN and HI antibodies against EDS virus at a rate similar to the whole virus and were significantly more efficient than the full-length fiber. The recombinant knob-s protein may be used as a vaccine against pathogenic adenovirus infections.

A Systematic Approach Toward Stabilization of CagL, a Protein Antigen from Helicobacter pylori That Is a Candidate Subunit Vaccine

PubMed Central

Choudhari, Shyamal P.; Pendleton, Kirk P.; Ramsey, Joshua D.; Blanchard, Thomas G.; Picking, William D.

2013-01-01

An important consideration in the development of subunit vaccines is loss of activity caused by physical instability of the protein. Such instability often results from suboptimal solution conditions related to pH and temperature. Excipients can help to stabilize vaccines, but it is important to screen and identify excipients that adequately contribute to stabilization of a given formulation. CagL is a protein present in strains of Helicobacter pylori that possess type IV secretion systems. It contributes to bacterial adherence via α5β1 integrin, thereby making it an attractive subunit vaccine candidate. We characterized the stability of CagL in different pH and temperature conditions using a variety of spectroscopic techniques. Stability was assessed in terms of transition temperature (Tm) with the accumulated data then incorporated into an empirical phase diagram (EPD) that provided an overview of CagL physical stability. These analyses indicated maximum CagL stability at pH 4–6 up to 40 °C in the absence of excipient. Using this EPD analysis, aggregation assays were developed to screen a panel of excipients with some found to inhibit CagL aggregation. Candidate stabilizers were selected to confirm their enhanced stabilizing effect. These analyses will help in the formulation of a stable vaccine against H. pylori. PMID:23794457

Stochastic simulation model comparing distributions of STEC O157 faecal shedding prevalence between cattle vaccinated with type III secreted protein vaccines and non-vaccinated cattle.

PubMed

Vogstad, A R; Moxley, R A; Erickson, G E; Klopfenstein, T J; Smith, D R

2014-06-01

Pens of cattle with high Escherichia coli O157:H7 (STEC O157) prevalence at harvest may present a greater risk to food safety than pens of lower prevalence. Vaccination of live cattle against STEC O157 has been proposed as an approach to reduce STEC O157 prevalence in live cattle. Our objective was to create a stochastic simulation model to evaluate the effectiveness of pre-harvest interventions. We used the model to compare STEC O157 prevalence distributions for summer- and winter-fed cattle to summer-fed cattle immunized with a type III secreted protein (TTSP) vaccine. Model inputs were an estimate of vaccine efficacy, observed frequency distributions for number of animals within a pen, and pen-level faecal shedding prevalence for summer and winter. Uncertainty about vaccine efficacy was simulated using a log-normal distribution (mean = 58%, SE = 0.14). Model outputs were distributions of STEC O157 faecal pen prevalence of summer-fed cattle unvaccinated and vaccinated, and winter-fed cattle unvaccinated. The simulation was performed 5000 times. Summer faecal prevalence ranged from 0% to 80% (average = 30%). Thirty-six per cent of summer-fed pens had STEC O157 prevalence >40%. Winter faecal prevalence ranged from 0% to 60% (average = 10%). Seven per cent of winter-fed pens had STEC O157 prevalence >40%. Faecal prevalence for summer-fed pens vaccinated with a 58% efficacious vaccine product ranged from 0% to 52% (average = 13%). Less than one per cent of vaccinated pens had STEC O157 prevalence >40%. In this simulation, vaccination mitigated the risk of STEC O157 faecal shedding to levels comparable to winter, with the major effects being reduced average shedding prevalence, reduced variability in prevalence distribution, and a reduction in the occurrence of the highest prevalence pens. Food safety decision-makers may find this modelling approach useful for evaluating the value of pre-harvest interventions. © 2013 Blackwell Verlag GmbH.

Quantitative Determination of Lethal Toxin Proteins in Culture Supernatant of Human Live Anthrax Vaccine Bacillus anthracis A16R

PubMed Central

Zai, Xiaodong; Zhang, Jun; Liu, Ju; Liu, Jie; Li, Liangliang; Yin, Ying; Fu, Ling; Xu, Junjie; Chen, Wei

2016-01-01

Bacillus anthracis (B. anthracis) is the etiological agent of anthrax affecting both humans and animals. Anthrax toxin (AT) plays a major role in pathogenesis. It includes lethal toxin (LT) and edema toxin (ET), which are formed by the combination of protective antigen (PA) and lethal factor (LF) or edema factor (EF), respectively. The currently used human anthrax vaccine in China utilizes live-attenuated B. anthracis spores (A16R; pXO1+, pXO2−) that produce anthrax toxin but cannot produce the capsule. Anthrax toxins, especially LT, have key effects on both the immunogenicity and toxicity of human anthrax vaccines. Thus, determining quantities and biological activities of LT proteins expressed by the A16R strain is meaningful. Here, we explored LT expression patterns of the A16R strain in culture conditions using another vaccine strain Sterne as a control. We developed a sandwich ELISA and cytotoxicity-based method for quantitative detection of PA and LF. Expression and degradation of LT proteins were observed in culture supernatants over time. Additionally, LT proteins expressed by the A16R and Sterne strains were found to be monomeric and showed cytotoxic activity, which may be the main reason for side effects of live anthrax vaccines. Our work facilitates the characterization of anthrax vaccines components and establishment of a quality control standard for vaccine production which may ultimately help to ensure the efficacy and safety of the human anthrax vaccine A16R. PMID:26927174

Quantitative Determination of Lethal Toxin Proteins in Culture Supernatant of Human Live Anthrax Vaccine Bacillus anthracis A16R.

PubMed

Zai, Xiaodong; Zhang, Jun; Liu, Ju; Liu, Jie; Li, Liangliang; Yin, Ying; Fu, Ling; Xu, Junjie; Chen, Wei

2016-02-25

Bacillus anthracis (B. anthracis) is the etiological agent of anthrax affecting both humans and animals. Anthrax toxin (AT) plays a major role in pathogenesis. It includes lethal toxin (LT) and edema toxin (ET), which are formed by the combination of protective antigen (PA) and lethal factor (LF) or edema factor (EF), respectively. The currently used human anthrax vaccine in China utilizes live-attenuated B. anthracis spores (A16R; pXO1+, pXO2-) that produce anthrax toxin but cannot produce the capsule. Anthrax toxins, especially LT, have key effects on both the immunogenicity and toxicity of human anthrax vaccines. Thus, determining quantities and biological activities of LT proteins expressed by the A16R strain is meaningful. Here, we explored LT expression patterns of the A16R strain in culture conditions using another vaccine strain Sterne as a control. We developed a sandwich ELISA and cytotoxicity-based method for quantitative detection of PA and LF. Expression and degradation of LT proteins were observed in culture supernatants over time. Additionally, LT proteins expressed by the A16R and Sterne strains were found to be monomeric and showed cytotoxic activity, which may be the main reason for side effects of live anthrax vaccines. Our work facilitates the characterization of anthrax vaccines components and establishment of a quality control standard for vaccine production which may ultimately help to ensure the efficacy and safety of the human anthrax vaccine A16R.

Immunity Elicited by an Experimental Vaccine Based on Recombinant Flagellin-Porcine Circovirus Type 2 Cap Fusion Protein in Piglets

PubMed Central

Wang, Jing; Wei, Li; Quan, Rong; Yang, Jiayu; Yan, Xu; Li, Zixuan; She, Ruiping; Hu, Fengjiao; Liu, Jue

2016-01-01

In a recent study, we reported that a recombinant protein from fusion expression of flagellin to porcine circovirus type 2 (PCV2) Cap induced robust humoral and cell-mediated immunity that afforded full protection for PCV2 infection using BALB/c mice. Here, we further evaluated the immunogenicity and protection of the recombinant protein using specific pathogen free (SPF) pigs. Twenty-five 3-week-old piglets without passively acquired immunity were divided into 5 groups. All piglets except negative controls were challenged with a virulent PCV2 at 21 days after booster vaccination and necropsied at 21 days post-challenge. Vaccination of piglets with the recombinant protein without adjuvant induced strong humoral and cellular immune responses as observed by high levels of PCV2-specific IgG antibodies and neutralizing antibodies, as well as frequencies of PCV2-specific IFN-γ-secreting cells that conferred good protection against PCV2 challenge, with significant reduced PCV2 viremia, mild lesions, low PCV2 antigen-positive cells, as well as improved body weight gain, comparable to piglets vaccinated with a commercial PCV2 subunit vaccine. These results further demonstrated that the recombinant flagellin-Cap fusion protein is capable of inducing solid protective humoral and cellular immunity when administered to pigs, thereby becoming an effective PCV2 vaccine candidate for control of PCV2 infection. PMID:26848967

Universal Vaccines and Vaccine Platforms to Protect against Influenza Viruses in Humans and Agriculture

PubMed Central

Rajão, Daniela S.; Pérez, Daniel R.

2018-01-01

Influenza virus infections pose a significant threat to public health due to annual seasonal epidemics and occasional pandemics. Influenza is also associated with significant economic losses in animal production. The most effective way to prevent influenza infections is through vaccination. Current vaccine programs rely heavily on the vaccine's ability to stimulate neutralizing antibody responses to the hemagglutinin (HA) protein. One of the biggest challenges to an effective vaccination program lies on the fact that influenza viruses are ever-changing, leading to antigenic drift that results in escape from earlier immune responses. Efforts toward overcoming these challenges aim at improving the strength and/or breadth of the immune response. Novel vaccine technologies, the so-called universal vaccines, focus on stimulating better cross-protection against many or all influenza strains. However, vaccine platforms or manufacturing technologies being tested to improve vaccine efficacy are heterogeneous between different species and/or either tailored for epidemic or pandemic influenza. Here, we discuss current vaccines to protect humans and animals against influenza, highlighting challenges faced to effective and uniform novel vaccination strategies and approaches. PMID:29467737

Recombinant and epitope-based vaccines on the road to the market and implications for vaccine design and production.

PubMed

Oyarzún, Patricio; Kobe, Bostjan

2016-03-03

Novel vaccination approaches based on rational design of B- and T-cell epitopes - epitope-based vaccines - are making progress in the clinical trial pipeline. The epitope-focused recombinant protein-based malaria vaccine (termed RTS,S) is a next-generation approach that successfully reached phase-III trials, and will potentially become the first commercial vaccine against a human parasitic disease. Progress made on methods such as recombinant DNA technology, advanced cell-culture techniques, immunoinformatics and rational design of immunogens are driving the development of these novel concepts. Synthetic recombinant proteins comprising both B- and T-cell epitopes can be efficiently produced through modern biotechnology and bioprocessing methods, and can enable the induction of large repertoires of immune specificities. In particular, the inclusion of appropriate CD4+ T-cell epitopes is increasingly considered a key vaccine component to elicit robust immune responses, as suggested by results coming from HIV-1 clinical trials. In silico strategies for vaccine design are under active development to address genetic variation in pathogens and several broadly protective "universal" influenza and HIV-1 vaccines are currently at different stages of clinical trials. Other methods focus on improving population coverage in target populations by rationally considering specificity and prevalence of the HLA proteins, though a proof-of-concept in humans has not been demonstrated yet. Overall, we expect immunoinformatics and bioprocessing methods to become a central part of the next-generation epitope-based vaccine development and production process.

Effect of fusion protein cleavage site sequence on generation of a genotype VII Newcastle disease virus vaccine.

PubMed

Manoharan, Vinoth K; Varghese, Berin P; Paldurai, Anandan; Samal, Siba K

2018-01-01

Newcastle disease (ND) causes severe economic loss to poultry industry worldwide. Frequent outbreaks of ND in commercial chickens vaccinated with live vaccines suggest a need to develop improved vaccines that are genetically matched against circulating Newcastle disease virus (NDV) strains. In this study, the fusion protein cleavage site (FPCS) sequence of NDV strain Banjarmasin/010 (Banj), a genotype VII NDV, was individually modified using primer mutagenesis to those of avian paramyxovirus (APMV) serotypes 2, 7 and 8 and compared with the recombinant Banjarmasin (rBanj) with avirulent NDV LaSota cleavage site (rBanj-LaSota). These FPCS mutations changed the in vitro cell-to-cell fusion activity and made rBanj FPCS mutant viruses highly attenuated in chickens. When chickens immunized with the rBanj FPCS mutant viruses and challenged with the virulent Banj, there was reduced challenge virus shedding observed compared to chickens immunized with the heterologous vaccine strain LaSota. Among the genotype VII NDV Banj vaccine candidates, rBanj-LaSota and rBanj containing FPCS of APMV-8 induced highest neutralizing antibody titers and protected chickens with reduced challenge virus shedding. These results show the effect of the F protein cleavage site sequence in generating genotype VII matched NDV vaccines.

Development of an indirect ELISA with epitope on nonstructural protein of Muscovy duck parvovirus for differentiating between infected and vaccinated Muscovy ducks.

PubMed

Yan, B; Ma, J-Z; Yu, T-F; Shao, S-L; Li, M; Fan, X-D

2014-12-01

The aim of this study was to develop an indirect enzyme-linked immunosorbent assay (i-ELISA) based on epitope AA503-509 (RANEPKE), which is on nonstructural protein of Muscovy duck parvovirus (MDPV). Sera (100) from negative and vaccinated Muscovy ducks were compared with infected sera (240) to establish the cut-off value of this i-ELISA. There was a significant difference between the positive and negative populations (P < 0·05). The adoption of this positive-negative threshold value for this i-ELISA assay resulted in specificity of 98·0%. This i-ELISA could be used as a diagnostic tool for differentiating infected Muscovy ducks from Muscovy ducks vaccinated with inactivated virus. In this study, we developed an i-ELISA based on epitope AA503-509 (RANEPKE), which is on nonstructural protein of MDPV. This i-ELISA could be used as a diagnostic tool for differentiating infected Muscovy ducks from Muscovy ducks vaccinated with inactivated virus. © 2014 The Society for Applied Microbiology.

Protein transduction domain of transactivating transcriptional activator fused to outer membrane protein K of Vibrio parahaemolyticus to vaccinate marbled eels (Anguilla marmorata) confers protection against mortality caused by V. parahaemolyticus.

PubMed

Wang, Hang; Yang, Wei; Shen, Guoying; Zhang, Jianting; Lv, Wei; Ji, Binfeng; Meng, Chun

2015-07-01

Although immersion and oral vaccination are the most practical methods for fish farmers, their applications are very limited due to low immune stimulation effect. We used the protein transduction domain (PTD) of transactivating transcriptional factor (TAT) derived from HIV TAT protein to increase the delivery efficiency of aquatic protein vaccines. Vibrio parahaemolyticus outer membrane protein K (ompK), a reported vaccine candidate for the prevention of V. parahaemolyticus infection, was fused with TAT-PTD expressed in Escherichia coli. We found that PTD-ompK fusion protein effectively penetrated into marbled eel bodies. Analysis of ompK antibody titres demonstrated that immersion vaccination with PTD-ompK was superior to ompK alone and induced robust immune stimulation in marbled eels. Both active and passive protection analyses against immersive challenge with V. parahaemolyticus strains demonstrated that marbled eels immunized with PTD-ompK survived significantly longer than those immunized with ompK alone. Our results indicated that TAT-PTD could be served as is an efficient delivery system for aquatic immersion vaccinations against various infectious diseases commonly seen in aquatic farm industry. © 2015 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Serum Concentrations of Antibodies against Outer Membrane Protein P6, Protein D, and T- and B-Cell Combined Antigenic Epitopes of Nontypeable Haemophilus influenzae in Children and Adults of Different Ages

PubMed Central

Hua, Chun-Zhen; Hu, Wei-Lin; Li, Jian-Ping; Hong, Li-Quan

2015-01-01

Nontypeable Haemophilus influenzae (NTHi) is one of the most common etiologies of acute otitis media, rhinosinusitis, and pneumonia. Outer membrane proteins (OMPs) are the main focus in new vaccine development against NTHi, as the H. influenzae type b (Hib) vaccine does not cover noncapsulated NTHi. The OMPs P6 and protein D are the most promising candidate antigens for an NTHi vaccine, and low antibody levels against them in serum may be correlated with infection caused by NTHi. In the current study, we measured the antibody titers against P6, protein D, and their T- and B-cell combined peptide epitopes in healthy individuals of different ages. We found that children <1 month old had the lowest antibody levels against NTHi P6, protein D, and their T- and B-cell combined antigenic epitopes. Antibody titers increased at ages 1 to 6 months, peaked at 7 months to 3 years, and remained high at 4 to 6 years. The antibody titers started to decrease after 6 years and were the lowest in the 21- to 30-year group. The geometric mean titers (GMTs) of T- and B-cell combined antigenic epitopes in P6 and protein D were positively correlated with those of the protein antigens. Among 12 peptides tested, P6-61, P6-123, and protein D-167 epitopes were better recognized than others in human serum. These findings might contribute to the development of an effective serotype-independent vaccine for H. influenzae. PMID:26677200

Vaccination of Gerbils with Bm-103 and Bm-RAL-2 Concurrently or as a Fusion Protein Confers Consistent and Improved Protection against Brugia malayi Infection.

PubMed

Arumugam, Sridhar; Wei, Junfei; Liu, Zhuyun; Abraham, David; Bell, Aaron; Bottazzi, Maria Elena; Hotez, Peter J; Zhan, Bin; Lustigman, Sara; Klei, Thomas R

2016-04-01

The Brugia malayi Bm-103 and Bm-RAL-2 proteins are orthologous to Onchocerca volvulus Ov-103 and Ov-RAL-2, and which were selected as the best candidates for the development of an O. volvulus vaccine. The B. malayi gerbil model was used to confirm the efficacy of these Ov vaccine candidates on adult worms and to determine whether their combination is more efficacious. Vaccine efficacy of recombinant Bm-103 and Bm-RAL-2 administered individually, concurrently or as a fusion protein were tested in gerbils using alum as adjuvant. Vaccination with Bm-103 resulted in worm reductions of 39%, 34% and 22% on 42, 120 and 150 days post infection (dpi), respectively, and vaccination with Bm-RAL-2 resulted in worm reductions of 42%, 22% and 46% on 42, 120 and 150 dpi, respectively. Vaccination with a fusion protein comprised of Bm-103 and Bm-RAL-2 resulted in improved efficacy with significant reduction of worm burden of 51% and 49% at 90 dpi, as did the concurrent vaccination with Bm-103 and Bm-RAL-2, with worm reduction of 61% and 56% at 90 dpi. Vaccination with Bm-103 and Bm-RAL-2 as a fusion protein or concurrently not only induced a significant worm reduction of 61% and 42%, respectively, at 150 dpi, but also significantly reduced the fecundity of female worms as determined by embryograms. Elevated levels of antigen-specific IgG were observed in all vaccinated gerbils. Serum from gerbils vaccinated with Bm-103 and Bm-RAL-2 individually, concurrently or as a fusion protein killed third stage larvae in vitro when combined with peritoneal exudate cells. Although vaccination with Bm-103 and Bm-RAL-2 individually conferred protection against B. malayi infection in gerbils, a more consistent and enhanced protection was induced by vaccination with Bm-103 and Bm-RAL-2 fusion protein and when they were used concurrently. Further characterization and optimization of these filarial vaccines are warranted.

Vaccination of Gerbils with Bm-103 and Bm-RAL-2 Concurrently or as a Fusion Protein Confers Consistent and Improved Protection against Brugia malayi Infection

PubMed Central

Arumugam, Sridhar; Wei, Junfei; Liu, Zhuyun; Abraham, David; Bell, Aaron; Bottazzi, Maria Elena; Hotez, Peter J.; Zhan, Bin; Lustigman, Sara; Klei, Thomas R.

2016-01-01

Background The Brugia malayi Bm-103 and Bm-RAL-2 proteins are orthologous to Onchocerca volvulus Ov-103 and Ov-RAL-2, and which were selected as the best candidates for the development of an O. volvulus vaccine. The B. malayi gerbil model was used to confirm the efficacy of these Ov vaccine candidates on adult worms and to determine whether their combination is more efficacious. Methodology and Principle Findings Vaccine efficacy of recombinant Bm-103 and Bm-RAL-2 administered individually, concurrently or as a fusion protein were tested in gerbils using alum as adjuvant. Vaccination with Bm-103 resulted in worm reductions of 39%, 34% and 22% on 42, 120 and 150 days post infection (dpi), respectively, and vaccination with Bm-RAL-2 resulted in worm reductions of 42%, 22% and 46% on 42, 120 and 150 dpi, respectively. Vaccination with a fusion protein comprised of Bm-103 and Bm-RAL-2 resulted in improved efficacy with significant reduction of worm burden of 51% and 49% at 90 dpi, as did the concurrent vaccination with Bm-103 and Bm-RAL-2, with worm reduction of 61% and 56% at 90 dpi. Vaccination with Bm-103 and Bm-RAL-2 as a fusion protein or concurrently not only induced a significant worm reduction of 61% and 42%, respectively, at 150 dpi, but also significantly reduced the fecundity of female worms as determined by embryograms. Elevated levels of antigen-specific IgG were observed in all vaccinated gerbils. Serum from gerbils vaccinated with Bm-103 and Bm-RAL-2 individually, concurrently or as a fusion protein killed third stage larvae in vitro when combined with peritoneal exudate cells. Conclusion Although vaccination with Bm-103 and Bm-RAL-2 individually conferred protection against B. malayi infection in gerbils, a more consistent and enhanced protection was induced by vaccination with Bm-103 and Bm-RAL-2 fusion protein and when they were used concurrently. Further characterization and optimization of these filarial vaccines are warranted. PMID:27045170

Bioinformatics analysis of ROP8 protein to improve vaccine design against Toxoplasma gondii.

PubMed

Foroutan, Masoud; Ghaffarifar, Fatemeh; Sharifi, Zohreh; Dalimi, Abdolhosein; Pirestani, Majid

2018-04-26

Rhoptry proteins (ROPs) are involved in the different stages of Toxoplasma gondii (T. gondii) invasion and are also critical for survival within host cells. ROP8 is expressed in the early stages of infection and have a key role in the parasitophorous vacuole (PV) formation. In this paper, we have combined several bioinformatics online servers for immunogenicity prediction of ROP8 protein. In this study, several bioinformatics approaches were used to analyze the different aspects of ROP8 protein, including the physico-chemical properties, transmembrane domain, subcellular localization, secondary and tertiary structure, B and T-cell potential epitopes, and other important characteristics of this protein. The findings showed that ROP8 protein had 60 potential post-translational modification sites. Also, only one transmembrane domain was recognized for this protein. The secondary structure of ROP8 protein comprises 33.04% alpha-helix, 18.26% extended strand, and 48.70% random coil. Moreover, several potential B and T-cell epitopes were identified for ROP8. In addition, the obtained findings from antigenicity and allergenicity evaluation remarked that this protein is immunogenic and non-allergen. Based on the results of Ramachandran plot, 94.8%, 4.1%, and 1.1% of amino acid residues were incorporated in the favored, allowed, and outlier regions, respectively. This paper provides a foundation for further investigations, and laid a theoretical basis for the development of an appropriate vaccine against toxoplasmosis. More studies are needed experimentally using the ROP8 alone or in combination with other antigens in the future. Copyright © 2018 Elsevier B.V. All rights reserved.

Protective immune response against Toxoplasma gondii elicited by a novel yeast-based vaccine with microneme protein 16.

PubMed

Wang, Long-Jiang; Xiao, Ting; Xu, Chao; Li, Jin; Liu, Gong-Zhen; Yin, Kun; Cui, Yong; Wei, Qing-Kuan; Huang, Bing-Cheng; Sun, Hui

2018-06-22

Toxoplasma gondii is an obligate intracellular protozoan that can invade all eukaryotic cells and infect all warm-blood animals, causing the important zoonosis toxoplasmosis. Invasion of host cells is the key step necessary for T. gondii to complete its life cycle and microneme proteins play an important role in attachment and invasion of host cells. Microneme protein 16 (TgMIC16) is a new protective protein in T. gondii and belongs to transmembrane microneme proteins (TM-MIC). The TM-MICs are released onto the parasite's surface as complexes capable of interacting with host cell receptors. In the present study, we expressed the TgMIC16 protein on the surface of Saccharomyce cerevisiae (pCTCON2-TgMIC16/EBY100) and evaluated it as a potential vaccine for BALB/c mice against challenge infection with the RH strain of T. gondii. We immunized BALB/c mice both orally and intraperitoneally. After three immunizations, the immune response was evaluated by measuring antibody levels, lymphocyte proliferative responses, percentages of CD4 + and CD8 + T lymphocytes, cytokine production, and the survival times of challenged mice. The results showed that the pCTCON2-TgMIC16/EBY100 vaccine stimulated humoral and cellular immune responses. In addition, mice immunized with the pCTCON2-TgMIC16/EBY100 vaccine showed increased survival times compared with non-immunized controls. In summary, TgMIC16 displayed on the cell surface of S. cerevisiae could be used as potential vaccine against toxoplasmosis. Copyright © 2018 Elsevier Ltd. All rights reserved.

DNA-MVA-protein vaccination of rhesus macaques induces HIV-specific immunity in mucosal-associated lymph nodes and functional antibodies.

PubMed

Chege, Gerald K; Burgers, Wendy A; Müller, Tracey L; Gray, Clive M; Shephard, Enid G; Barnett, Susan W; Ferrari, Guido; Montefiori, David; Williamson, Carolyn; Williamson, Anna-Lise

2017-02-07

Successful future HIV vaccines are expected to generate an effective cellular and humoral response against the virus in both the peripheral blood and mucosal compartments. We previously reported the development of DNA-C and MVA-C vaccines based on HIV-1 subtype C and demonstrated their immunogenicity when given in a DNA prime-MVA boost combination in a nonhuman primate model. In the current study, rhesus macaques previously vaccinated with a DNA-C and MVA-C vaccine regimen were re-vaccinated 3.5years later with MVA-C followed by a protein vaccine based on HIV-1 subtype C envelope formulated with MF59 adjuvant (gp140Env/MF59), and finally a concurrent boost with both vaccines. A single MVA-C re-vaccination elicited T cell responses in all animals similar to previous peak responses, with 4/7 demonstrating responses >1000 SFU/10 6 PBMC. In contrast to an Env/MF59-only vaccine, concurrent boosting with MVA-C and Env/MF59 induced HIV-specific cellular responses in multiple mucosal associated lymph nodes in 6/7 animals, with high magnitude responses in some animals. Both vaccine regimens induced high titer Env-specific antibodies with ADCC activity, as well as neutralization of Tier 1 viruses and modest Tier 2 neutralization. These data demonstrate the feasibility of inducing HIV-specific immunity in the blood and mucosal sites of viral entry by means of DNA and poxvirus-vectored vaccines, in combination with a HIV envelope-based protein vaccine. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Coadministration of the Three Antigenic Leishmania infantum Poly (A) Binding Proteins as a DNA Vaccine Induces Protection against Leishmania major Infection in BALB/c Mice

PubMed Central

Corvo, Laura; Garde, Esther; Ramírez, Laura; Iniesta, Virginia; Bonay, Pedro; Gómez-Nieto, Carlos; González, Víctor M.; Martín, M. Elena; Alonso, Carlos; Coelho, Eduardo A. F.; Barral, Aldina; Barral-Netto, Manoel

2015-01-01

Background Highly conserved intracellular proteins from Leishmania have been described as antigens in natural and experimental infected mammals. The present study aimed to evaluate the antigenicity and prophylactic properties of the Leishmania infantum Poly (A) binding proteins (LiPABPs). Methodology/Principal Findings Three different members of the LiPABP family have been described. Recombinant tools based on these proteins were constructed: recombinant proteins and DNA vaccines. The three recombinant proteins were employed for coating ELISA plates. Sera from human and canine patients of visceral leishmaniasis and human patients of mucosal leishmaniasis recognized the three LiPABPs. In addition, the protective efficacy of a DNA vaccine based on the combination of the three Leishmania PABPs has been tested in a model of progressive murine leishmaniasis: BALB/c mice infected with Leishmania major. The induction of a Th1-like response against the LiPABP family by genetic vaccination was able to down-regulate the IL-10 predominant responses elicited by parasite LiPABPs after infection in this murine model. This modulation resulted in a partial protection against L. major infection. LiPABP vaccinated mice showed a reduction on the pathology that was accompanied by a decrease in parasite burdens, in antibody titers against Leishmania antigens and in the IL-4 and IL-10 parasite-specific mediated responses in comparison to control mice groups immunized with saline or with the non-recombinant plasmid. Conclusion/Significance The results presented here demonstrate for the first time the prophylactic properties of a new family of Leishmania antigenic intracellular proteins, the LiPABPs. The redirection of the immune response elicited against the LiPABP family (from IL-10 towards IFN-γ mediated responses) by genetic vaccination was able to induce a partial protection against the development of the disease in a highly susceptible murine model of leishmaniasis. PMID:25955652

Outer membrane protein complex of Meningococcus enhances the antipolysaccharide antibody response to pneumococcal polysaccharide-CRM₁₉₇ conjugate vaccine.

PubMed

Lai, Zengzu; Schreiber, John R

2011-05-01

Bacterial polysaccharides (PS) are T cell-independent antigens that do not induce immunologic memory and are poor immunogens in infants. Conjugate vaccines in which the PS is covalently linked to a carrier protein have enhanced immunogenicity that resembles that of T cell-dependent antigens. The Haemophilus influenzae type b (Hib) conjugate vaccine, which uses the outer membrane protein complex (OMPC) from meningococcus as a carrier protein, elicits protective levels of anti-capsular PS antibody (Ab) after a single dose, in contrast to other conjugate vaccines, which require multiple doses. We have previously shown that OMPC robustly engages Toll-like receptor 2 (TLR2) and enhances the early anti-Hib PS Ab titer associated with an increase in TLR2-mediated induction of cytokines. We now show that the addition of OMPC to the 7-valent pneumococcal PS-CRM₁₉₇ conjugate vaccine during immunization significantly increases the anti-PS IgG and IgM responses to most serotypes of pneumococcus contained in the vaccine. The addition of OMPC also increased the likelihood of anti-PS IgG3 production against serotypes 4, 6B, 9V, 18C, 19F, and 23F. Splenocytes from mice who had received OMPC with the pneumococcal conjugate vaccine produced significantly more interleukin-2 (IL-2), IL-4, IL-6, IL-10, tumor necrosis factor alpha (TNF-α), and gamma interferon (IFN-γ) than splenocytes from mice who received phosphate-buffered saline (PBS) plus the conjugate vaccine. We conclude that OMPC enhances the anti-PS Ab response to pneumococcal PS-CRM₁₉₇ conjugate vaccine, an effect associated with a distinct change in cytokine profile. It may be possible to reduce the number of conjugate vaccine doses required to achieve protective Ab levels by priming with adjuvants that are TLR2 ligands.

Vaccination Against Whipworm: Identification of Potential Immunogenic Proteins in Trichuris muris Excretory/Secretory Material.

PubMed

Shears, Rebecca K; Bancroft, Allison J; Sharpe, Catherine; Grencis, Richard K; Thornton, David J

2018-03-14

Trichuris trichiura (whipworm) is one of the four major soil-transmitted helminth infections of man, affecting an estimated 465 million people worldwide. An effective vaccine that induces long-lasting protective immunity against T. trichiura would alleviate the morbidity associated with this intestinal-dwelling parasite, however the lack of known host protective antigens has hindered vaccine development. Here, we show that vaccination with ES products stimulates long-lasting protection against chronic infection in male C57BL/6 mice. We also provide a framework for the identification of immunogenic proteins within T. muris ES, and identify eleven candidates with direct homologues in T. trichiura that warrant further study. Given the extensive homology between T. muris and T. trichiura at both the genomic and transcriptomic levels, this work has the potential to advance vaccine design for T. trichiura.

A Recombinant Respiratory Syncytial Virus Vaccine Candidate Attenuated by a Low-Fusion F Protein Is Immunogenic and Protective against Challenge in Cotton Rats

PubMed Central

Rostad, Christina A.; Stobart, Christopher C.; Gilbert, Brian E.; Pickles, Ray J.; Hotard, Anne L.; Meng, Jia; Blanco, Jorge C. G.; Moin, Syed M.; Graham, Barney S.; Piedra, Pedro A.

2016-01-01

ABSTRACT Although respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in infants, a safe and effective vaccine is not yet available. Live-attenuated vaccines (LAVs) are the most advanced vaccine candidates in RSV-naive infants. However, designing an LAV with appropriate attenuation yet sufficient immunogenicity has proven challenging. In this study, we implemented reverse genetics to address these obstacles with a multifaceted LAV design that combined the codon deoptimization of genes for nonstructural proteins NS1 and NS2 (dNS), deletion of the small hydrophobic protein (ΔSH) gene, and replacement of the wild-type fusion (F) protein gene with a low-fusion RSV subgroup B F consensus sequence of the Buenos Aires clade (BAF). This vaccine candidate, RSV-A2-dNS-ΔSH-BAF (DB1), was attenuated in two models of primary human airway epithelial cells and in the upper and lower airways of cotton rats. DB1 was also highly immunogenic in cotton rats and elicited broadly neutralizing antibodies against a diverse panel of recombinant RSV strains. When vaccinated cotton rats were challenged with wild-type RSV A, DB1 reduced viral titers in the upper and lower airways by 3.8 log10 total PFU and 2.7 log10 PFU/g of tissue, respectively, compared to those in unvaccinated animals (P < 0.0001). DB1 was thus attenuated, highly immunogenic, and protective against RSV challenge in cotton rats. DB1 is the first RSV LAV to incorporate a low-fusion F protein as a strategy to attenuate viral replication and preserve immunogenicity. IMPORTANCE RSV is a leading cause of infant hospitalizations and deaths. The development of an effective vaccine for this high-risk population is therefore a public health priority. Although live-attenuated vaccines have been safely administered to RSV-naive infants, strategies to balance vaccine attenuation with immunogenicity have been elusive. In this study, we introduced a novel strategy to attenuate a recombinant RSV

Immunogenicity and safety of the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) co-administered with DTPa vaccine in Japanese children: A randomized, controlled study

PubMed Central

Iwata, Satoshi; Kawamura, Naohisa; Kuroki, Haruo; Tokoeda, Yasunobu; Miyazu, Mitsunobu; Iwai, Asayuki; Oishi, Tomohiro; Sato, Tomohide; Suyama, Akari; François, Nancy; Shafi, Fakrudeen; Ruiz-Guiñazú, Javier; Borys, Dorota

2015-01-01

This phase III, randomized, open-label, multicenter study (NCT01027845) conducted in Japan assessed the immunogenicity, safety, and reactogenicity of 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV, given intramuscularly) co-administered with diphtheria-tetanus-acellular pertussis vaccine (DTPa, given subcutaneously). Infants (N=360 ) were randomized (2:1) to receive either PHiD-CV and DTPa (PHiD-CV group) or DTPa alone (control group) as 3-dose primary vaccination (3–4–5 months of age) and booster vaccination (17–19 months of age). Immune responses were measured before and one month after primary/booster vaccination and adverse events (AEs) were recorded. Post-primary immune responses were non-inferior to those in pivotal/efficacy European or Latin American pneumococcal protein D-conjugate vaccine studies. For each PHiD-CV serotype, at least 92.6% of infants post-primary vaccination and at least 97.7% of children post-booster had pneumococcal antibody concentrations ≥0.2 μg/ml, and at least 95.4% post-primary and at least 98.1% post-booster had opsonophagocytic activity (OPA) titers ≥8 . Geometric mean antibody concentrations and OPA titers (except OPA titer for 6B) were higher post-booster than post-priming for each serotype. All PHiD-CV-vaccinated children had anti-protein D antibody concentrations ≥100 EL.U/ml one month post-primary/booster vaccination and all were seroprotected/seropositive against each DTPa antigen. Redness and irritability were the most common solicited AEs in both groups. Incidences of unsolicited AEs were comparable between groups. Serious AEs were reported for 47 children (28 in PHiD-CV group); none were assessed as vaccine-related. In conclusion, PHiD-CV induced robust immune responses and was well tolerated when co-administered with DTPa in a 3-dose priming plus booster regimen to Japanese children. PMID:25830489

Display of HIV-1 Envelope Protein on Lambda Phage Scaffold as a Vaccine Platform.

PubMed

Mattiacio, Jonelle L; Brewer, Matt; Dewhurst, Stephen

2017-01-01

The generation of a strong antibody response to target antigens is a major goal for vaccine development. Here we describe the display of the human immunodeficiency virus (HIV) envelope spike protein (Env) on a virus-like scaffold provided by the lambda phage capsid. Phage vectors, in general, have advantages over mammalian virus vectors due to their genetic tractability, inexpensive production, suitability for scale-up, as well as their physical stability, making them an attractive vaccine platform.

A conserved region of leptospiral immunoglobulin-like A and B proteins as a DNA vaccine elicits a prophylactic immune response against leptospirosis.

PubMed

Forster, Karine M; Hartwig, Daiane D; Seixas, Fabiana K; Bacelo, Kátia L; Amaral, Marta; Hartleben, Cláudia P; Dellagostin, Odir A

2013-05-01

The leptospiral immunoglobulin-like (Lig) proteins LigA and LigB possess immunoglobulin-like domains with 90-amino-acid repeats and are adhesion molecules involved in pathogenicity. They are conserved in pathogenic Leptospira spp. and thus are of interest for use as serodiagnostic antigens and in recombinant vaccine formulations. The N-terminal amino acid sequences of the LigA and LigB proteins are identical, but the C-terminal sequences vary. In this study, we evaluated the protective potential of five truncated forms of LigA and LigB proteins from Leptospira interrogans serovar Canicola as DNA vaccines using the pTARGET mammalian expression vector. Hamsters immunized with the DNA vaccines were subjected to a heterologous challenge with L. interrogans serovar Copenhageni strain Spool via the intraperitoneal route. Immunization with a DNA vaccine encoding LigBrep resulted in the survival of 5/8 (62.5%) hamsters against lethal infection (P < 0.05). None of the control hamsters or animals immunized with the other vaccine preparations survived. The vaccine induced an IgG antibody response and, additionally, conferred sterilizing immunity in 80% of the surviving animals. Our results indicate that the LigBrep DNA vaccine is a promising candidate for inclusion in a protective leptospiral vaccine.

A Conserved Region of Leptospiral Immunoglobulin-Like A and B Proteins as a DNA Vaccine Elicits a Prophylactic Immune Response against Leptospirosis

PubMed Central

Forster, Karine M.; Hartwig, Daiane D.; Seixas, Fabiana K.; Bacelo, Kátia L.; Amaral, Marta; Hartleben, Cláudia P.

2013-01-01

The leptospiral immunoglobulin-like (Lig) proteins LigA and LigB possess immunoglobulin-like domains with 90-amino-acid repeats and are adhesion molecules involved in pathogenicity. They are conserved in pathogenic Leptospira spp. and thus are of interest for use as serodiagnostic antigens and in recombinant vaccine formulations. The N-terminal amino acid sequences of the LigA and LigB proteins are identical, but the C-terminal sequences vary. In this study, we evaluated the protective potential of five truncated forms of LigA and LigB proteins from Leptospira interrogans serovar Canicola as DNA vaccines using the pTARGET mammalian expression vector. Hamsters immunized with the DNA vaccines were subjected to a heterologous challenge with L. interrogans serovar Copenhageni strain Spool via the intraperitoneal route. Immunization with a DNA vaccine encoding LigBrep resulted in the survival of 5/8 (62.5%) hamsters against lethal infection (P < 0.05). None of the control hamsters or animals immunized with the other vaccine preparations survived. The vaccine induced an IgG antibody response and, additionally, conferred sterilizing immunity in 80% of the surviving animals. Our results indicate that the LigBrep DNA vaccine is a promising candidate for inclusion in a protective leptospiral vaccine. PMID:23486420

Universal influenza vaccines: Shifting to better vaccines.

PubMed

Berlanda Scorza, Francesco; Tsvetnitsky, Vadim; Donnelly, John J

2016-06-03

Influenza virus causes acute upper and lower respiratory infections and is the most likely, among known pathogens, to cause a large epidemic in humans. Influenza virus mutates rapidly, enabling it to evade natural and vaccine-induced immunity. Furthermore, influenza viruses can cross from animals to humans, generating novel, potentially pandemic strains. Currently available influenza vaccines induce a strain specific response and may be ineffective against new influenza viruses. The difficulty in predicting circulating strains has frequently resulted in mismatch between the annual vaccine and circulating viruses. Low-resource countries remain mostly unprotected against seasonal influenza and are particularly vulnerable to future pandemics, in part, because investments in vaccine manufacturing and stockpiling are concentrated in high-resource countries. Antibodies that target conserved sites in the hemagglutinin stalk have been isolated from humans and shown to confer protection in animal models, suggesting that broadly protective immunity may be possible. Several innovative influenza vaccine candidates are currently in preclinical or early clinical development. New technologies include adjuvants, synthetic peptides, virus-like particles (VLPs), DNA vectors, messenger RNA, viral vectors, and attenuated or inactivated influenza viruses. Other approaches target the conserved exposed epitope of the surface exposed membrane matrix protein M2e. Well-conserved influenza proteins, such as nucleoprotein and matrix protein, are mainly targeted for developing strong cross-protective T cell responses. With multiple vaccine candidates moving along the testing and development pipeline, the field is steadily moving toward a product that is more potent, durable, and broadly protective than previously licensed vaccines. Copyright © 2016 World Health Organization. Published by Elsevier Ltd.. All rights reserved.

Vaccination against the M protein of Streptococcus pyogenes prevents death after influenza virus:S. pyogenes super-infection

PubMed Central

Klonoski, Joshua M.; Hurtig, Heather R.; Juber, Brian A.; Schuneman, Margaret J.; Bickett, Thomas E.; Svendsen, Joshua M.; Burum, Brandon; Penfound, Thomas A.; Sereda, Grigoriy; Dale, James B.; Chaussee, Michael S.; Huber, Victor C.

2014-01-01

Influenza virus infections are associated with a significant number of illnesses and deaths on an annual basis. Many of the deaths are due to complications from secondary bacterial invaders, including Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, and Streptococcus pyogenes. The β-hemolytic bacteria S. pyogenes colonizes both skin and respiratory surfaces, and frequently presents clinically as strep throat or impetigo. However, when these bacteria gain access to normally sterile sites, they can cause deadly diseases including sepsis, necrotizing fasciitis, and pneumonia. We previously developed a model of influenza virus:S. pyogenes super-infection, which we used to demonstrate that vaccination against influenza virus can limit deaths associated with a secondary bacterial infection, but this protection was not complete. In the current study, we evaluated the efficacy of a vaccine that targets the M protein of S. pyogenes to determine whether immunity toward the bacteria alone would allow the host to survive an influenza virus:S. pyogenes super-infection. Our data demonstrate that vaccination against the M protein induces IgG antibodies, in particular those of the IgG1 and IgG2a isotypes, and that these antibodies can interact with macrophages. Ultimately, this vaccine-induced immunity eliminated death within our influenza virus:S. pyogenes super-infection model, despite the fact that all M protein-vaccinated mice showed signs of illness following influenza virus inoculation. These findings identify immunity against bacteria as an important component of protection against influenza virus:bacteria super-infection. PMID:25077423

Development of Safe and Effective RSV Vaccine by Modified CD4 Epitope in G Protein Core Fragment (Gcf)

PubMed Central

Park, Sung-Moo; Choi, Youngjoo; Jang, Ji Eun; Jung, Dae Im; Kim, Jae-Ouk; Chang, Jun; Yun, Cheol-Heui; Song, Man Ki

2014-01-01

Respiratory syncytial virus (RSV) is a major cause of respiratory tract infection in infants and young children worldwide, but currently no safe and effective vaccine is available. The RSV G glycoprotein (RSVG), a major attachment protein, is an important target for the induction of protective immune responses during RSV infection. However, it has been thought that a CD4+ T cell epitope (a.a. 183–195) within RSVG is associated with pathogenic pulmonary eosinophilia. To develop safe and effective RSV vaccine using RSV G protein core fragment (Gcf), several Gcf variants resulting from modification to CD4+ T cell epitope were constructed. Mice were immunized with each variant Gcf, and the levels of RSV-specific serum IgG were measured. At day 4 post-challenge with RSV subtype A or B, lung viral titers and pulmonary eosinophilia were determined and changes in body weight were monitored. With wild type Gcf derived from RSV A2 (wtAGcf), although RSV A subtype-specific immune responses were induced, vaccine-enhanced disease characterized by excessive pulmonary eosinophil recruitment and body weight loss were evident, whereas wtGcf from RSV B1 (wtBGcf) induced RSV B subtype-specific immune responses without the signs of vaccine-enhanced disease. Mice immunized with Th-mGcf, a fusion protein consisting CD4+ T cell epitope from RSV F (F51–66) conjugated to mGcf that contains alanine substitutions at a.a. position 185 and 188, showed higher levels of RSV-specific IgG response than mice immunized with mGcf. Both wtAGcf and Th-mGcf provided complete protection against RSV A2 and partial protection against RSV B. Importantly, mice immunized with Th-mGcf did not develop vaccine-enhanced disease following RSV challenge. Immunization of Th-mGcf provided protection against RSV infection without the symptom of vaccine-enhanced disease. Our study provides a novel strategy to develop a safe and effective mucosal RSV vaccine by manipulating the CD4+ T cell epitope within RSV G

Nanogel antigenic protein-delivery system for adjuvant-free intranasal vaccines

NASA Astrophysics Data System (ADS)

Nochi, Tomonori; Yuki, Yoshikazu; Takahashi, Haruko; Sawada, Shin-Ichi; Mejima, Mio; Kohda, Tomoko; Harada, Norihiro; Kong, Il Gyu; Sato, Ayuko; Kataoka, Nobuhiro; Tokuhara, Daisuke; Kurokawa, Shiho; Takahashi, Yuko; Tsukada, Hideo; Kozaki, Shunji; Akiyoshi, Kazunari; Kiyono, Hiroshi

2010-07-01

Nanotechnology is an innovative method of freely controlling nanometre-sized materials. Recent outbreaks of mucosal infectious diseases have increased the demands for development of mucosal vaccines because they induce both systemic and mucosal antigen-specific immune responses. Here we developed an intranasal vaccine-delivery system with a nanometre-sized hydrogel (`nanogel') consisting of a cationic type of cholesteryl-group-bearing pullulan (cCHP). A non-toxic subunit fragment of Clostridium botulinum type-A neurotoxin BoHc/A administered intranasally with cCHP nanogel (cCHP-BoHc/A) continuously adhered to the nasal epithelium and was effectively taken up by mucosal dendritic cells after its release from the cCHP nanogel. Vigorous botulinum-neurotoxin-A-neutralizing serum IgG and secretory IgA antibody responses were induced without co-administration of mucosal adjuvant. Importantly, intranasally administered cCHP-BoHc/A did not accumulate in the olfactory bulbs or brain. Moreover, intranasally immunized tetanus toxoid with cCHP nanogel induced strong tetanus-toxoid-specific systemic and mucosal immune responses. These results indicate that cCHP nanogel can be used as a universal protein-based antigen-delivery vehicle for adjuvant-free intranasal vaccination.

Current status of flavivirus vaccines.

PubMed

Barrett, A D

2001-12-01

Although there are approximately 68 flaviviruses recognized, vaccines have been developed to control very few human flavivirus diseases. Licensed live attenuated vaccines have been developed for yellow fever (strain 17D) and Japanese encephalitis (strain SA14-14-2) viruses, and inactivated vaccines have been developed for Japanese encephalitis and tick-borne encephalitis viruses. The yellow fever live attenuated 17D vaccine is one of the most efficacious and safe vaccines developed to date and has been used to immunize more than 300 million people. A number of experimental vaccines are being developed, most notably for dengue. Candidate tetravalent live attenuated dengue vaccines are undergoing clinical trials. Other vaccines are being developed using reverse genetics, DNA vaccines, and recombinant immunogens. In addition, the yellow fever 17D vaccine has been used as a backbone to generate chimeric viruses containing the premembrane and envelope protein genes from other flaviviruses. The "Chimerivax" platform has been used to construct chimeric Japanese encephalitis and dengue viruses that are in different phases of development. Similar strategies are being used by other laboratories.

Evaluation of the Potency, Neutralizing Antibody Response, and Stability of a Recombinant Fusion Protein Vaccine for Streptococcus pyogenes.

PubMed

Burlet, E; HogenEsch, H; Dunham, A; Morefield, G

2017-05-01

Streptococcus pyogenes or group A streptococcus (GAS) is a Gram-positive bacterium that can cause a wide range of diseases, including pharyngitis, impetigo, scarlet fever, necrotizing fasciitis, rheumatic fever, and streptococcal toxic shock syndrome. Despite the increasing burden on global health caused by GAS, there is currently no licensed vaccine available. In this study, we evaluated immunogenicity, induction of neutralizing antibodies, and stability of a new recombinant fusion protein vaccine that targets infections from GAS. The recombinant fusion protein (SpeAB) combines inactive mutant forms of streptococcal pyrogenic exotoxin A (SpeA) and streptococcal pyrogenic exotoxin B (SpeB). The SpeAB vaccine evaluated in this study was adsorbed to an aluminum adjuvant and demonstrated robust immunogenicity, eliciting production of specific neutralizing antibodies against SpeA and SpeB, two major virulence factors of S. pyogenes. Stability studies suggest that the vaccine will retain immunogenicity for at least 2 years when stored at refrigerated temperatures. This novel vaccine shows great potential to provide protection against GAS infections and to reduce the burden of GAS disease globally.

Safety and immunogenicity of 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) in Nigerian children

PubMed Central

Odusanya, Olumuyiwa O; Kuyinu, Yetunde A; Kehinde, Omolara A; Shafi, Fakrudeen; François, Nancy; Yarzabal, Juan Pablo; Dobbelaere, Kurt; Rüggeberg, Jens U; Borys, Dorota; Schuerman, Lode

2014-01-01

In a previous study, 3-dose primary vaccination of Nigerian infants with the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) was immunogenic for vaccine pneumococcal serotypes, with comparable tolerability between PHiD-CV and control groups. In an open-label study (ClinicalTrials.gov, NCT01153893), 68 primed children received a PHiD-CV booster dose co-administered with a diphtheria-tetanus-acellular pertussis (DTPa) booster dose at 15–21 months and 36 children unprimed for pneumococcal vaccination received two PHiD-CV catch-up doses (first dose co-administered with DTPa booster dose) at 15–21 and 17–23 months. Adverse events were recorded and immune responses were measured before and one month after vaccination. In both groups, pain was the most frequent solicited local symptom and fever was the most frequent solicited general symptom after the booster dose and each catch-up dose. Few grade 3 solicited symptoms and no vaccine-related serious adverse events were reported. After booster vaccination, for each vaccine serotype, at least 98.5% of children had an antibody concentration ≥0.2 µg/ml and at least 94.0% had an opsonophagocytic activity (OPA) titer ≥8. After 2-dose catch-up, for each vaccine serotype, at least 97.1% had an antibody concentration ≥0.2 µg/ml, except for serotypes 6B (82.9%) and 23F (88.6%), and at least 91.4% had an OPA titer ≥8, except for serotypes 6B (77.4%) and 19F (85.3%). PHiD-CV induced antibody responses against protein D in both groups. In conclusion, PHiD-CV administered to Nigerian toddlers as a booster dose or 2-dose catch-up was well tolerated and immunogenic for vaccine pneumococcal serotypes and protein D. PMID:24356787

Roadmap to developing a recombinant coronavirus S protein receptor-binding domain vaccine for severe acute respiratory syndrome

PubMed Central

Jiang, Shibo; Bottazzi, Maria Elena; Du, Lanying; Lustigman, Sara; Tseng, Chien-Te Kent; Curti, Elena; Jones, Kathryn; Zhan, Bin; Hotez, Peter J

2013-01-01

A subunit vaccine, RBD-S, is under development to prevent severe acute respiratory syndrome (SARS) caused by SARS coronavirus (SARS-CoV), which is classified by the US NIH as a category C pathogen. This vaccine is comprised of a recombinant receptor-binding domain (RBD) of the SARS-CoV spike (S) protein and formulated on alum, together with a synthetic glucopyranosyl lipid A. The vaccine would induce neutralizing antibodies without causing Th2-type immunopathology. Vaccine development is being led by the nonprofit product development partnership; Sabin Vaccine Institute and Texas Children’s Hospital Center for Vaccine Development in collaboration with two academic partners (the New York Blood Center and University of Texas Medical Branch); an industrial partner (Immune Design Corporation); and Walter Reed Army Institute of Research. A roadmap for the product development of the RBD-S SARS vaccine is outlined with a goal to manufacture the vaccine for clinical testing within the next 5 years. PMID:23252385

Vaccination of captive nēnē (Branta sandvicensis) against West Nile virus using a protein-based vaccine (WN-80E).

PubMed

Jarvi, Susan I; Hu, Darcy; Misajon, Kathleen; Coller, Beth-Ann; Wong, Teri; Lieberman, Michael M

2013-01-01

Although West Nile Virus (WNV) has not been reported in Hawai'i, eventual introduction appears unavoidable with potential adverse effects on avian species. Nēnē (Branta sandvicensis) are endemic endangered Hawaiian geese that are susceptible to WNV. We demonstrate that a vaccine developed against WNV for humans (WN-80E) is also highly immunogenic in Nēnē and does not produce adverse biologic effects. Six captive, nonbreeding Nēnē were immunized with two 10-μg doses (4 wk apart) of the WN-80E recombinant protein adjuvanted with Montanide ISA720. Two Nēnē were similarly injected with "mock" preparation as controls. Blood samples were collected before the first dose, then 2 wk and 6 mo after the second dose. WNV-specific antibody titers were determined by an endpoint enzyme-linked immunosorbent assay. An unpaired t-test demonstrated significantly higher geometric mean titers for immunized vs. control groups 2 wk after dose 2 (4,129 and 100, respectively, P=0.010) and 6 mo after dose 2 (246 and 63, respectively, P=0.002). Daily observations revealed no swelling at the site of injection and no serious adverse biological effects from the immunization. The vaccine containing the WN-80E and Montanide ISA720 adjuvant appears to be safe and immunogenic in Nēnē. This protein-based WNV vaccine may be safer for use in Hawai'i than killed virus and live chimeric or recombinant canarypox-vectored vaccines because it cannot cause disease.

Identification of L. infantum chagasi proteins in VL patients' urine: a promising antigen discovery approach of vaccine candidates

PubMed Central

Kashino, Suely S.; Abeijon, Claudia; Qin, Lizeng; Kanunfre, Kelly A.; Kubrusly, Flávia S.; Silva, Fernando O.; Costa, Dorcas L.; Campos, Dioclécio; Costa, Carlos H.N.; Raw, Isaias; Campos-Neto, Antonio

2012-01-01

Visceral leishmaniasis (VL) is a serious lethal parasitic disease caused by Leishmania donovani in Asia and by Leishmania infantum chagasi in Southern Europe and South America. VL is endemic in 47 countries with an annual incidence estimated to be 500,000 cases. This high incidence is due in part to the lack of an efficacious vaccine. Here, we introduce an innovative approach to directly identify parasite vaccine candidate antigens that are abundantly produced in vivo in humans with VL. We combined RP-HPLC and mass spectrometry and categorized three L. infantum chagasi proteins, presumably produced in spleen, liver, and bone marrow lesions and excreted in the patients’ urine. Specifically, these proteins were the following: Li-isd1 (XP_001467866.1), Li-txn1 (XP_001466642.1), and Li-ntf2 (XP_001463738.1). Initial vaccine validation studies were performed with the rLi-ntf2 protein produced in E. coli mixed with the adjuvant BpMPLA-SE. This formulation stimulated potent Th1 response in BALB/c mice. Compared to control animals, mice immunized with Li-ntf2 + BpMPLASE had a marked parasite burden reduction in spleens at 40 days post-challenge with virulent L. infantum chagasi. These results strongly support the proposed antigen discovery strategy of vaccine candidates to kala-azar and opens novel possibilities for vaccine development to other serious infectious diseases. PMID:22443237

Cell-free production of a functional oligomeric form of a Chlamydia major outer-membrane protein (MOMP) for vaccine development

DOE PAGES

He, Wei; Felderman, Martina; Evans, Angela C.; ...

2017-07-24

Chlamydia is a prevalent sexually transmitted disease that infects more than 100 million people worldwide. Although most individuals infected with Chlamydia trachomatis are initially asymptomatic, symptoms can arise if left undiagnosed. Long-term infection can result in debilitating conditions such as pelvic inflammatory disease, infertility, and blindness. Chlamydia infection, therefore, constitutes a significant public health threat, underscoring the need for a Chlamydia-specific vaccine. Chlamydia strains express a major outer-membrane protein (MOMP) that has been shown to be an effective vaccine antigen. However, approaches to produce a functional recombinant MOMP protein for vaccine development are limited by poor solubility, low yield, andmore » protein misfolding. For this study, we used an Escherichia coli-based cell-free system to express a MOMP protein from the mouse-specific species Chlamydia muridarum (MoPn-MOMP or mMOMP). The codon-optimized mMOMP gene was co-translated with Δ49apolipoprotein A1 (Δ49ApoA1), a truncated version of mouse ApoA1 in which the N-terminal 49 amino acids were removed. This co-translation process produced mMOMP supported within a telodendrimer nanolipoprotein particle (mMOMP–tNLP). The cell-free expressed mMOMP–tNLPs contain mMOMP multimers similar to the native MOMP protein. This cell-free process produced on average 1.5 mg of purified, water-soluble mMOMP–tNLP complex in a 1-ml cell-free reaction. The mMOMP–tNLP particle also accommodated the co-localization of CpG oligodeoxynucleotide 1826, a single-stranded synthetic DNA adjuvant, eliciting an enhanced humoral immune response in vaccinated mice. Using our mMOMP–tNLP formulation, we demonstrate a unique approach to solubilizing and administering membrane-bound proteins for future vaccine development. This method can be applied to other previously difficult-to-obtain antigens while maintaining full functionality and immunogenicity.« less

Cell-free production of a functional oligomeric form of a Chlamydia major outer-membrane protein (MOMP) for vaccine development

DOE Office of Scientific and Technical Information (OSTI.GOV)

He, Wei; Felderman, Martina; Evans, Angela C.

Chlamydia is a prevalent sexually transmitted disease that infects more than 100 million people worldwide. Although most individuals infected with Chlamydia trachomatis are initially asymptomatic, symptoms can arise if left undiagnosed. Long-term infection can result in debilitating conditions such as pelvic inflammatory disease, infertility, and blindness. Chlamydia infection, therefore, constitutes a significant public health threat, underscoring the need for a Chlamydia-specific vaccine. Chlamydia strains express a major outer-membrane protein (MOMP) that has been shown to be an effective vaccine antigen. However, approaches to produce a functional recombinant MOMP protein for vaccine development are limited by poor solubility, low yield, andmore » protein misfolding. For this study, we used an Escherichia coli-based cell-free system to express a MOMP protein from the mouse-specific species Chlamydia muridarum (MoPn-MOMP or mMOMP). The codon-optimized mMOMP gene was co-translated with Δ49apolipoprotein A1 (Δ49ApoA1), a truncated version of mouse ApoA1 in which the N-terminal 49 amino acids were removed. This co-translation process produced mMOMP supported within a telodendrimer nanolipoprotein particle (mMOMP–tNLP). The cell-free expressed mMOMP–tNLPs contain mMOMP multimers similar to the native MOMP protein. This cell-free process produced on average 1.5 mg of purified, water-soluble mMOMP–tNLP complex in a 1-ml cell-free reaction. The mMOMP–tNLP particle also accommodated the co-localization of CpG oligodeoxynucleotide 1826, a single-stranded synthetic DNA adjuvant, eliciting an enhanced humoral immune response in vaccinated mice. Using our mMOMP–tNLP formulation, we demonstrate a unique approach to solubilizing and administering membrane-bound proteins for future vaccine development. This method can be applied to other previously difficult-to-obtain antigens while maintaining full functionality and immunogenicity.« less

Induction of a robust immunity response against novel duck reovirus in ducklings using a subunit vaccine of sigma C protein

PubMed Central

Bi, Zhuangli; Zhu, Yingqi; Chen, Zongyan; Li, Chuanfeng; Wang, Yong; Wang, Guijun; Liu, Guangqing

2016-01-01

Novel duck reovirus (NDRV) disease emerged in China in 2011 and continues to cause high morbidity and about 5.0 to 50% mortality in ducklings. Currently there are no approved vaccines for the virus. This study aimed to assess the efficacy of a new vaccine created from the baculovirus and sigma C gene against NDRV. In this study, a recombinant baculovirus containing the sigma C gene was constructed, and the purified protein was used as a vaccine candidate in ducklings. The efficacy of sigma C vaccine was estimated according to humoral immune responses, cellular immune response and protection against NDRV challenge. The results showed that sigma C was highly expressed in Sf9 cells. Robust humoral and cellular immune responses were induced in all ducklings immunized with the recombinant sigma C protein. Moreover, 100% protection against lethal challenge with NDRV TH11 strain was observed. Summary, the recombinant sigma C protein could be utilized as a good candidate against NDRV infection. PMID:27974824

Diagnostic Approach for Differentiating Infected from Vaccinated Poultry on the Basis of Antibodies to NS1, the Nonstructural Protein of Influenza A Virus

PubMed Central

Tumpey, Terrence M.; Alvarez, Rene; Swayne, David E.; Suarez, David L.

2005-01-01

Vaccination programs for the control of avian influenza (AI) in poultry have limitations due to the problem of differentiating between vaccinated and virus-infected birds. We have used NS1, the conserved nonstructural protein of influenza A virus, as a differential diagnostic marker for influenza virus infection. Experimentally infected poultry were evaluated for the ability to induce antibodies reactive to NS1 recombinant protein produced in Escherichia coli or to chemically synthesized NS1 peptides. Immune sera were obtained from chickens and turkeys inoculated with live AI virus, inactivated purified vaccines, or inactivated commercial vaccines. Seroconversion to positivity for antibodies to the NS1 protein was achieved in birds experimentally infected with multiple subtypes of influenza A virus, as determined by enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. In contrast, animals inoculated with inactivated gradient-purified vaccines had no seroconversion to positivity for antibodies to the NS1 protein, and animals vaccinated with commercial vaccines had low, but detectable, levels of NS1 antibodies. The use of a second ELISA with diluted sera identified a diagnostic test that results in seropositivity for antibodies to the NS1 protein only in infected birds. For the field application phase of this study, serum samples were collected from vaccinated and infected poultry, diluted, and screened for anti-NS1 antibodies. Field sera from poultry that received commercial AI vaccines were found to possess antibodies against AI virus, as measured by the standard agar gel precipitin (AGP) test, but they were negative by the NS1 ELISA. Conversely, diluted field sera from AI-infected poultry were positive for both AGP and NS1 antibodies. These results demonstrate the potential benefit of a simple, specific ELISA for anti-NS1 antibodies that may have diagnostic value for the poultry industries. PMID:15695663

Controlling chitosan-based encapsulation for protein and vaccine delivery

PubMed Central

Koppolu, Bhanu prasanth; Smith, Sean G.; Ravindranathan, Sruthi; Jayanthi, Srinivas; Kumar, Thallapuranam K.S.; Zaharoff, David A.

2014-01-01

Chitosan-based nano/microencapsulation is under increasing investigation for the delivery of drugs, biologics and vaccines. Despite widespread interest, the literature lacks a defined methodology to control chitosan particle size and drug/protein release kinetics. In this study, the effects of precipitation-coacervation formulation parameters on chitosan particle size, protein encapsulation efficiency and protein release were investigated. Chitosan particle sizes, which ranged from 300 nm to 3 μm, were influenced by chitosan concentration, chitosan molecular weight and addition rate of precipitant salt. The composition of precipitant salt played a significant role in particle formation with upper Hofmeister series salts containing strongly hydrated anions yielding particles with a low polydispersity index (PDI) while weaker anions resulted in aggregated particles with high PDIs. Sonication power had minimal effect on mean particle size, however, it significantly reduced polydispersity. Protein loading efficiencies in chitosan nano/microparticles, which ranged from 14.3% to 99.2%, was inversely related to the hydration strength of precipitant salts, protein molecular weight and directly related to the concentration and molecular weight of chitosan. Protein release rates increased with particle size and were generally inversely related to protein molecular weight. This study demonstrates that chitosan nano/microparticles with high protein loading efficiencies can be engineered with well-defined sizes and controllable release kinetics through manipulation of specific formulation parameters. PMID:24560459

Bystander protein protects potential vaccine-targeting ligands against intestinal proteolysis.

PubMed

Reuter, Fabian; Bade, Steffen; Hirst, Timothy R; Frey, Andreas

2009-07-20

Endowing mucosal vaccines with ligands that target antigen to mucosal lymphoid tissues may improve immunization efficacy provided that the ligands withstand the proteolytic environment of the gastro-intestinal tract until they reach their destination. Our aim was to investigate whether and how three renowned ligands - Ulex europaeus agglutinin I and the B subunits of cholera toxin and E. coli heat-labile enterotoxin - master this challenge. We assessed the digestive power of natural murine intestinal fluid (natIF) using assays for trypsin, chymotrypsin and pancreatic elastase along with a test for nonspecific proteolysis. The natIF was compared with simulated murine intestinal fluid (simIF) that resembled the trypsin, chymotrypsin and elastase activities of its natural counterpart but lacked or contained albumins as additional protease substrates. The ligands were exposed to the digestive fluids and degradation was determined. The studies revealed that (i) the three pancreatic endoproteases constitute only one third of the total protease activity of natIF and (ii) the ligands resist proteolysis in natIF and protein-enriched simIF over 3 h but (iii) are partially destroyed in simIF that lacks additional protease substrate. We assume that the proteins of natIF are preferred substrates for the intestinal proteases and thus can protect vaccine-targeting ligands from destruction.

Epitope-based recombinant diagnostic antigen to distinguish natural infection from vaccination with hepatitis A virus vaccines.

PubMed

Su, Qiudong; Guo, Minzhuo; Jia, Zhiyuan; Qiu, Feng; Lu, Xuexin; Gao, Yan; Meng, Qingling; Tian, Ruiguang; Bi, Shengli; Yi, Yao

2016-07-01

Hepatitis A virus (HAV) infection can stimulate the production of antibodies to structural and non-structural proteins of the virus. However, vaccination with an inactivated or attenuated HAV vaccine produces antibodies mainly against structural proteins, whereas no or very limited antibodies are produced against the non-structural proteins. Current diagnostic assays to determine exposure to HAV, such as the Abbott HAV AB test, detect antibodies only to the structural proteins and so are not able to distinguish a natural infection from vaccination with an inactivated or attenuated virus. Here, we constructed a recombinant tandem multi-epitope diagnostic antigen (designated 'H1') based on the immune-dominant epitopes of the non-structural proteins of HAV to distinguish the two situations. H1 protein expressed in Escherichia coli and purified by affinity and anion exchange chromatography was applied in a double-antigen sandwich ELISA for the detection of anti-non-structural HAV proteins, which was confirmed to distinguish a natural infection from vaccination with an inactivated or attenuated HAV vaccine. Copyright © 2016 Elsevier B.V. All rights reserved.

An Overview of Vaccination Strategies and Antigen Delivery Systems for Streptococcus agalactiae Vaccines in Nile Tilapia (Oreochromis niloticus).

PubMed

Munang'andu, Hetron Mweemba; Paul, Joydeb; Evensen, Øystein

2016-12-13

Streptococcus agalactiae is an emerging infectious disease adversely affecting Nile tilapia ( Niloticus oreochromis ) production in aquaculture. Research carried out in the last decade has focused on developing protective vaccines using different strategies, although no review has been carried out to evaluate the efficacy of these strategies. The purpose of this review is to provide a synopsis of vaccination strategies and antigen delivery systems currently used for S. agalactiae vaccines in tilapia. Furthermore, as shown herein, current vaccine designs include the use of replicative antigen delivery systems, such as attenuated virulent strains, heterologous vectors and DNA vaccines, while non-replicative vaccines include the inactivated whole cell (IWC) and subunit vaccines encoding different S. agalactiae immunogenic proteins. Intraperitoneal vaccination is the most widely used immunization strategy, although immersion, spray and oral vaccines have also been tried with variable success. Vaccine efficacy is mostly evaluated by use of the intraperitoneal challenge model aimed at evaluating the relative percent survival (RPS) of vaccinated fish. The major limitation with this approach is that it lacks the ability to elucidate the mechanism of vaccine protection at portals of bacterial entry in mucosal organs and prevention of pathology in target organs. Despite this, indications are that the correlates of vaccine protection can be established based on antibody responses and antigen dose, although these parameters require optimization before they can become an integral part of routine vaccine production. Nevertheless, this review shows that different approaches can be used to produce protective vaccines against S. agalactiae in tilapia although there is a need to optimize the measures of vaccine efficacy.

An Overview of Vaccination Strategies and Antigen Delivery Systems for Streptococcus agalactiae Vaccines in Nile Tilapia (Oreochromis niloticus)

PubMed Central

Munang’andu, Hetron Mweemba; Paul, Joydeb; Evensen, Øystein

2016-01-01

Streptococcus agalactiae is an emerging infectious disease adversely affecting Nile tilapia (Niloticus oreochromis) production in aquaculture. Research carried out in the last decade has focused on developing protective vaccines using different strategies, although no review has been carried out to evaluate the efficacy of these strategies. The purpose of this review is to provide a synopsis of vaccination strategies and antigen delivery systems currently used for S. agalactiae vaccines in tilapia. Furthermore, as shown herein, current vaccine designs include the use of replicative antigen delivery systems, such as attenuated virulent strains, heterologous vectors and DNA vaccines, while non-replicative vaccines include the inactivated whole cell (IWC) and subunit vaccines encoding different S. agalactiae immunogenic proteins. Intraperitoneal vaccination is the most widely used immunization strategy, although immersion, spray and oral vaccines have also been tried with variable success. Vaccine efficacy is mostly evaluated by use of the intraperitoneal challenge model aimed at evaluating the relative percent survival (RPS) of vaccinated fish. The major limitation with this approach is that it lacks the ability to elucidate the mechanism of vaccine protection at portals of bacterial entry in mucosal organs and prevention of pathology in target organs. Despite this, indications are that the correlates of vaccine protection can be established based on antibody responses and antigen dose, although these parameters require optimization before they can become an integral part of routine vaccine production. Nevertheless, this review shows that different approaches can be used to produce protective vaccines against S. agalactiae in tilapia although there is a need to optimize the measures of vaccine efficacy. PMID:27983591

A novel, disruptive vaccination technology: self-adjuvanted RNActive(®) vaccines.

PubMed

Kallen, Karl-Josef; Heidenreich, Regina; Schnee, Margit; Petsch, Benjamin; Schlake, Thomas; Thess, Andreas; Baumhof, Patrick; Scheel, Birgit; Koch, Sven D; Fotin-Mleczek, Mariola

2013-10-01

Nucleotide based vaccines represent an enticing, novel approach to vaccination. We have developed a novel immunization technology, RNActive(®) vaccines, that have two important characteristics: mRNA molecules are used whose protein expression capacity has been enhanced by 4 to 5 orders of magnitude by modifications of the nucleotide sequence with the naturally occurring nucleotides A (adenosine), G (guanosine), C (cytosine), U (uridine) that do not affect the primary amino acid sequence. Second, they are complexed with protamine and thus activate the immune system by involvement of toll-like receptor (TLR) 7. Essentially, this bestows self-adjuvant activity on RNActive(®) vaccines. RNActive(®) vaccines induce strong, balanced immune responses comprising humoral and cellular responses, effector and memory responses as well as activation of important subpopulations of immune cells, such as Th1 and Th2 cells. Pre-germinal center and germinal center B cells were detected in human patients upon vaccination. RNActive(®) vaccines successfully protect against lethal challenges with a variety of different influenza strains in preclinical models. Anti-tumor activity was observed preclinically under therapeutic as well as prophylactic conditions. Initial clinical experiences suggest that the preclinical immunogenicity of RNActive(®) could be successfully translated to humans.

CD4+ T Cells Mediate Aspergillosis Vaccine Protection.

PubMed

Diaz-Arevalo, Diana; Kalkum, Markus

2017-01-01

Adaptive effector CD4 + T cells play essential roles in the defense against fungal infections, especially against invasive aspergillosis (IA). Such protective CD4 + T cells can be generated through immunization with specialized antifungal vaccines, as has been demonstrated for pulmonary Aspergillus fumigatus infections in mouse experiments. Adaptive transfer of fungal antigen-specific CD4 + T cells conferred protection onto non-immunized naive mice, an experimental approach that could potentially become a future treatment option for immunosuppressed IA patients, focusing on the ultimate goal to improve their otherwise dim chances for survival. Here, we describe the different techniques to analyze CD4 + T cell immune responses after immunization with a recombinant fungal protein. We present three major methods that are used to analyze the role of CD4 + T cells in protection against A. fumigatus challenge. They include (1) transplantation of CD4 + T cells from vaccinated mice into immunosuppressed naive mice, observing increasing protection of the cell recipients, (2) depletion of CD4 + T cells from vaccinated mice, which abolishes vaccine protection, and (3) T cell proliferation studies following stimulation with overlapping synthetic peptides or an intact protein vaccine. The latter can be used to validate immunization status and to identify protective T cell epitopes in vaccine antigens. In the methods detailed here, we used versions of the well-studied Asp f3 protein expressed in a bacterial host, either as the intact full length protein or its N-terminally truncated version, comprised of residues 15-168. However, these methods are generally applicable and can well be adapted to study other protein-based subunit vaccines.

Use of Prior Vaccinations for the Development of New Vaccines

NASA Astrophysics Data System (ADS)

Etlinger, H. M.; Gillessen, D.; Lahm, H.-W.; Matile, H.; Schonfeld, H.-J.; Trzeciak, A.

1990-07-01

There is currently a need for vaccine development to improve the immunogenicity of protective epitopes, which themselves are often poorly immunogenic. Although the immunogenicity of these epitopes can be enhanced by linking them to highly immunogenic carriers, such carriers derived from current vaccines have not proven to be generally effective. One reason may be related to epitope-specific suppression, in which prior vaccination with a protein can inhibit the antibody response to new epitopes linked to the protein. To circumvent such inhibition, a peptide from tetanus toxoid was identified that, when linked to a B cell epitope and injected into tetanus toxoid-primed recipients, retained sequences for carrier but not suppressor function. The antibody response to the B cell epitope was enhanced. This may be a general method for taking advantage of previous vaccinations in the development of new vaccines.

Application of bluetongue Disabled Infectious Single Animal (DISA) vaccine for different serotypes by VP2 exchange or incorporation of chimeric VP2.

PubMed

Feenstra, Femke; Pap, Janny S; van Rijn, Piet A

2015-02-04

Bluetongue is a disease of ruminants caused by the bluetongue virus (BTV). Bluetongue outbreaks can be controlled by vaccination, however, currently available vaccines have several drawbacks. Further, there are at least 26 BTV serotypes, with low cross protection. A next-generation vaccine based on live-attenuated BTV without expression of non-structural proteins NS3/NS3a, named Disabled Infectious Single Animal (DISA) vaccine, was recently developed for serotype 8 by exchange of the serotype determining outer capsid protein VP2. DISA vaccines are replicating vaccines but do not cause detectable viremia, and induce serotype specific protection. Here, we exchanged VP2 of laboratory strain BTV1 for VP2 of European serotypes 2, 4, 8 and 9 using reverse genetics, without observing large effects on virus growth. Exchange of VP2 from serotype 16 and 25 was however not possible. Therefore, chimeric VP2 proteins of BTV1 containing possible immunogenic regions of these serotypes were studied. BTV1, expressing 1/16 chimeric VP2 proteins was functional in virus replication in vitro and contained neutralizing epitopes of both serotype 1 and 16. For serotype 25 this approach failed. We combined VP2 exchange with the NS3/NS3a negative phenotype in BTV1 as previously described for serotype 8 DISA vaccine. DISA vaccine with 1/16 chimeric VP2 containing amino acid region 249-398 of serotype 16 raised antibodies in sheep neutralizing both BTV1 and BTV16. This suggests that DISA vaccine could be protective for both parental serotypes present in chimeric VP2. We here demonstrate the application of the BT DISA vaccine platform for several serotypes and further extend the application for serotypes that are unsuccessful in single VP2 exchange. Copyright © 2014 Elsevier Ltd. All rights reserved.

A Recombinant Respiratory Syncytial Virus Vaccine Candidate Attenuated by a Low-Fusion F Protein Is Immunogenic and Protective against Challenge in Cotton Rats.

PubMed

Rostad, Christina A; Stobart, Christopher C; Gilbert, Brian E; Pickles, Ray J; Hotard, Anne L; Meng, Jia; Blanco, Jorge C G; Moin, Syed M; Graham, Barney S; Piedra, Pedro A; Moore, Martin L

2016-08-15

Although respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in infants, a safe and effective vaccine is not yet available. Live-attenuated vaccines (LAVs) are the most advanced vaccine candidates in RSV-naive infants. However, designing an LAV with appropriate attenuation yet sufficient immunogenicity has proven challenging. In this study, we implemented reverse genetics to address these obstacles with a multifaceted LAV design that combined the codon deoptimization of genes for nonstructural proteins NS1 and NS2 (dNS), deletion of the small hydrophobic protein (ΔSH) gene, and replacement of the wild-type fusion (F) protein gene with a low-fusion RSV subgroup B F consensus sequence of the Buenos Aires clade (BAF). This vaccine candidate, RSV-A2-dNS-ΔSH-BAF (DB1), was attenuated in two models of primary human airway epithelial cells and in the upper and lower airways of cotton rats. DB1 was also highly immunogenic in cotton rats and elicited broadly neutralizing antibodies against a diverse panel of recombinant RSV strains. When vaccinated cotton rats were challenged with wild-type RSV A, DB1 reduced viral titers in the upper and lower airways by 3.8 log10 total PFU and 2.7 log10 PFU/g of tissue, respectively, compared to those in unvaccinated animals (P < 0.0001). DB1 was thus attenuated, highly immunogenic, and protective against RSV challenge in cotton rats. DB1 is the first RSV LAV to incorporate a low-fusion F protein as a strategy to attenuate viral replication and preserve immunogenicity. RSV is a leading cause of infant hospitalizations and deaths. The development of an effective vaccine for this high-risk population is therefore a public health priority. Although live-attenuated vaccines have been safely administered to RSV-naive infants, strategies to balance vaccine attenuation with immunogenicity have been elusive. In this study, we introduced a novel strategy to attenuate a recombinant RSV vaccine by

Optimized transitory ectopic expression of promastigote surface antigen protein in Nicotiana benthamiana, a potential anti-leishmaniasis vaccine candidate.

PubMed

Lacombe, Séverine; Bangratz, Martine; Brizard, Jean-Paul; Petitdidier, Elodie; Pagniez, Julie; Sérémé, Drissa; Lemesre, Jean-Loup; Brugidou, Christophe

2018-01-01

In recent years, plants have been shown to be an efficient alternative expression system for high-value pharmaceuticals such as vaccines. However, constitutive expression of recombinant protein remains uncertain on their level of production and biological activity. To overcome these problems, transitory expression systems have been developed. Here, a series of experiments were performed to determine the most effective conditions to enhance vaccine antigen transient accumulation in Nicotiana benthamiana leaves using the promastigote surface antigen (PSA) from the parasitic protozoan Leishmania infantum. This protein has been previously identified as the major antigen of a licensed canine anti-leishmaniasis vaccine. The classical prokaryote Escherichia coli biosystem failed in accumulating PSA. Consequently, the standard plant system based on N. benthamiana has been optimized for the production of putatively active PSA. First, the RNA silencing defense mechanism set up by the plant against PSA ectopic expression was abolished by using three viral suppressors acting at different steps of the RNA silencing pathway. Then, we demonstrated that the signal peptide at the N-terminal side of the PSA is required for its accumulation. The PSA ER signaling and retention with the PSA signal peptide and the KDEL motif, respectively were optimized to significantly increase its accumulation. Finally, we demonstrate that the production of recombinant PSA in N. benthamiana leaves allows the conservation of its immunogenic property. These approaches demonstrate that based on these optimizations, plant based systems can be used to effectively produce the biological active PSA protein. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Vaccines of the future.

PubMed

Nossal, G J V

2011-12-30

Vaccines of the future can be divided into three broad groups, namely those of the near future (<10 years); the medium-term future (10-19 years); and the long-term future (20-50 years). For the near future, there is some "low hanging fruit" which is clearly on the horizon, such as a Vi-conjugate vaccine for typhoid or a protein-based vaccine for Neisseria meningitidis serogroup B. Just slightly more distant will be vaccines for shigellosis and a common protein vaccine for Streptococcus pneumoniae. Also in this group, but not as far advanced, will be a vaccine for Group A streptococcus. I place vaccines for the "big three", malaria, tuberculosis and HIV/AIDS in the medium term basket. The sporozoite malaria vaccine RTS-S is closest, but surely a definitive malaria vaccine will also require antigens from other stages of the life cycle. A tuberculosis vaccine will be either a re-engineered BCG; or a molecular vaccine with several protein antigens; or one based on prime-boost strategies. What will delay this is the high cost of clinical trials. For HIV/AIDS, the partial success of the Sanofi-Pasteur prime-boost vaccine has given some hope. I still place much faith in antibody-based vaccines and especially on mimotopes of the env transitional state assumed after initial CD4 binding. Monoclonal antibodies are also leading us in interesting directions. Longer term, the vaccine approach will be successful for autoimmune diseases, e.g. juvenile diabetes and coeliac disease. Cancer vaccines are also briefly surveyed. Adjunct issues needing to be addressed include more extensive combinations; alternate delivery systems; and more intelligently designed adjuvants based on knowledge of the innate immune system. Copyright © 2011. Published by Elsevier Ltd.

Recommendations for administering the triple viral vaccine and antiinfluenza vaccine in patients with egg allergy.

PubMed

Piquer-Gibert, M; Plaza-Martín, A; Martorell-Aragonés, A; Ferré-Ybarz, L; Echeverría-Zudaire, L; Boné-Calvo, J; Nevot-Falcó, S

2007-01-01

Actually, food allergy is an emerging pathology; and egg allergy is the most frequent in childhood. The recommendations for measles, mumps and rubella (MMR) and influenza vaccination are increasing each year. This implementation increases the exposure of patients with egg allergy to such vaccines. In Spain, since 2004 the only available vaccine for MMR is grown in cultures of fibroblast from chick embryos; previously, patients with egg allergy were vaccinated with an alternative vaccine cultivated in diploid human cells which is no longer commercialized. Influenza vaccines grow in chick egg and the final product contains egg proteins (large variation in egg protein content has been reported). As controversy exist, the Food Allergy Committee of Spanish Society of Clinical Immunology and Pediatric Allergy decided to report some recommendations for the safe administration of MMR and influenza vaccines in patients with egg allergy. In summary, MMR vaccine is safe for children with egg allergy, only in patients with severe anaphylactic reaction after egg ingestion is recommended the administration in his reference hospital. Influenza vaccine is contraindicated in patients with severe anaphylactic reaction after egg ingestion. The rest can receive influenza vaccine in a 2-dose protocol with a vaccine that contains no more than 1.2 mcg of egg protein for mL.

Induction of immunologic memory following primary vaccination with the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine in infants.

PubMed

Knuf, Markus; Pankow-Culot, Heidemarie; Grunert, Detlef; Rapp, Michael; Panzer, Falko; Köllges, Ralph; Fanic, Aurélie; Habib, Ahsan; Borys, Dorota; Dieussaert, Ilse; Schuerman, Lode

2012-01-01

Induction of immunologic memory was assessed following primary vaccination with 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV). Infants were randomized (1:1) to receive 3 doses of PHiD-CV or 7vCRM (7-valent CRM197-conjugated pneumococcal conjugate vaccine [PCV]) at 2, 3, and 4 months of age followed by 23-valent pneumococcal polysaccharide vaccine (23vPS) booster dose at 11 to 14 months of age. Pneumococcal geometric mean antibody concentrations (GMCs) and opsonophagocytic activity (OPA) geometric mean titers were measured. Postprimary immune responses were consistent with those in previous PHiD-CV and 7vCRM studies. Following 23vPS boosting, vaccine serotype-specific antibody GMCs increased 6.5- to 33.3-fold and 4.8- to 32.2-fold versus prebooster in the PHiD-CV and 7vCRM groups, respectively. Postbooster OPA titers increased 2.8- to 38.8-fold and 2.6- to 58.9-fold, respectively. Postbooster antibody GMCs exceeded postprimary levels but, for some serotypes, postbooster OPA geometric mean titers were lower than postprimary in both groups. An additional dose of the same PCV received for priming was administered to 52 children aged 46 to 50 months, resulting in higher responses versus postprimary vaccination for all serotypes, but not always higher than post-23vPS booster. Induction of immunologic memory following PHiD-CV priming was confirmed. Additional PCV boosting in 4-year-olds did not provide strong evidence of hyporesponsiveness induced by previous 23vPS boosting. However, our results did not rule out depletion of the memory B cell pool following 23vPS vaccination, resulting in subsequent attenuated immune responses, and therefore support the use of PCV rather than 23vPS for booster vaccination in the second year of life.

Current status of meningococcal group B vaccine candidates: capsular or noncapsular?

PubMed

Diaz Romero, J; Outschoorn, I M

1994-10-01

Meningococcal meningitis is a severe, life-threatening infection for which no adequate vaccine exists. Current vaccines, based on the group-specific capsular polysaccharides, provide short-term protection in adults against serogroups A and C but are ineffective in infants and do not induce protection against group B strains, the predominant cause of infection in western countries, because the purified serogroup B polysaccharide fails to elicit human bactericidal antibodies. Because of the poor immunogenicity of group B capsular polysaccharide, different noncapsular antigens have been considered for inclusion in a vaccine against this serogroup: outer membrane proteins, lipooligosaccharides, iron-regulated proteins, Lip, pili, CtrA, and the immunoglobulin A proteases. Alternatively, attempts to increase the immunogenicity of the capsular polysaccharide have been made by using noncovalent complexes with outer membrane proteins, chemical modifications, and structural analogs. Here, we review the strategies employed for the development of a vaccine for Neisseria meningitidis serogroup B; the difficulties associated with the different approaches are discussed.

Current status of meningococcal group B vaccine candidates: capsular or noncapsular?

PubMed Central

Diaz Romero, J; Outschoorn, I M

1994-01-01

Meningococcal meningitis is a severe, life-threatening infection for which no adequate vaccine exists. Current vaccines, based on the group-specific capsular polysaccharides, provide short-term protection in adults against serogroups A and C but are ineffective in infants and do not induce protection against group B strains, the predominant cause of infection in western countries, because the purified serogroup B polysaccharide fails to elicit human bactericidal antibodies. Because of the poor immunogenicity of group B capsular polysaccharide, different noncapsular antigens have been considered for inclusion in a vaccine against this serogroup: outer membrane proteins, lipooligosaccharides, iron-regulated proteins, Lip, pili, CtrA, and the immunoglobulin A proteases. Alternatively, attempts to increase the immunogenicity of the capsular polysaccharide have been made by using noncovalent complexes with outer membrane proteins, chemical modifications, and structural analogs. Here, we review the strategies employed for the development of a vaccine for Neisseria meningitidis serogroup B; the difficulties associated with the different approaches are discussed. PMID:7834605

Recombinant NAD-dependent SIR-2 protein of Leishmania donovani: immunobiochemical characterization as a potential vaccine against visceral leishmaniasis.

PubMed

Baharia, Rajendra K; Tandon, Rati; Sharma, Tanuj; Suthar, Manish K; Das, Sanchita; Siddiqi, Mohammad Imran; Saxena, Jitendra Kumar; Sundar, Shaym; Sunder, Shyam; Dube, Anuradha

2015-03-01

The development of a vaccine conferring long-lasting immunity remains a challenge against visceral leishmaniasis (VL). Immunoproteomic characterization of Leishmania donovani proteins led to the identification of a novel protein NAD+-dependent Silent Information regulatory-2 (SIR2 family or sirtuin) protein (LdSir2RP) as one of the potent immunostimulatory proteins. Proteins of the SIR2 family are characterized by a conserved catalytic domain that exerts unique NAD-dependent deacetylase activity. In the present study, an immunobiochemical characterization of LdSir2RP and further evaluation of its immunogenicity and prophylactic potential was done to assess for its possible involvement as a vaccine candidate against leishmaniasis. LdSir2RP was successfully cloned, expressed and purified. The gene was present as a monomeric protein of ~45 kDa and further established by the crosslinking experiment. rLdSir2RP shown cytosolic localization in L. donovani and demonstrating NAD+-dependent deacetylase activity. Bioinformatic analysis also confirmed that LdSir2RP protein has NAD binding domain. The rLdSir2RP was further assessed for its cellular response by lymphoproliferative assay and cytokine ELISA in cured Leishmania patients and hamsters (Mesocricetus auratus) in comparison to soluble Leishmania antigen and it was observed to stimulate the production of IFN-γ, IL-12 and TNF-α significantly but not the IL-4 and IL-10. The naïve hamsters when vaccinated with rLdSir2RP alongwith BCG resisted the L. donovani challenge to the tune of ~75% and generated strong IL-12 and IFN-γ mediated Th1 type immune response thereof. The efficacy was further supported by remarkable increase in IgG2 antibody level which is indicative of Th1 type of protective response. Further, with a possible implication in vaccine design against VL, identification of potential T-cell epitopes of rLdSir2RP was done using computational approach. The immunobiochemical characterization strongly suggest the

A randomised trial to evaluate the immunogenicity, reactogenicity, and safety of the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) co-administered with routine childhood vaccines in Singapore and Malaysia.

PubMed

Lim, Fong Seng; Koh, Mia Tuang; Tan, Kah Kee; Chan, Poh Chong; Chong, Chia Yin; Shung Yehudi, Yeo Wee; Teoh, Yee Leong; Shafi, Fakrudeen; Hezareh, Marjan; Swinnen, Kristien; Borys, Dorota

2014-10-02

The immunogenicity, reactogenicity, and safety of the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) co-administered with routine childhood vaccines were evaluated among infants from Singapore and Malaysia, where PHiD-CV has been licensed. In the primary vaccination phase, 298 infants from Singapore and 168 infants from Malaysia were randomised to receive the Phase III Clinical (Clin) or the Commercial (Com) lot of PHiD-CV at 2, 3, and 5 months of age. In the booster vaccination phase, 238 toddlers from Singapore received one dose of the PHiD-CV Commercial lot at 18-21 months of age. Immune responses to pneumococcal polysaccharides were measured using 22F-inhibition enzyme-linked immunosorbent assay (ELISA) and functional opsonophagocytic activity (OPA) assay and to protein D, using ELISA. Immune responses induced by primary vaccination with the PHiD-CV Commercial lot were non-inferior to the Phase III Clinical lot in terms of adjusted antibody geometric mean concentration (GMC) ratios for each vaccine pneumococcal serotype and protein D. For each vaccine pneumococcal serotype, ≥93.6% and ≥88.5% of infants from Malaysia and Singapore had post-primary vaccination antibody concentrations ≥0.2 μg/mL and OPA titres ≥8, in the Clin and Com groups, respectively. For each vaccine pneumococcal serotype, ≥60.8% and ≥98.2% of toddlers from Singapore had pre- and post-booster antibody concentrations ≥0.2 μg/mL, in the Clin and Com groups, respectively. All children, except one, had measurable anti-protein D antibodies and the primary and booster doses of the co-administered vaccines were immunogenic. The incidence of each grade 3 solicited symptom was ≤11.1% in both study phases. No serious adverse events considered causally related to vaccination were reported throughout the study. PHiD-CV given as three-dose primary vaccination to infants in Singapore and Malaysia and booster vaccination to toddlers in

Virus like particle-based vaccines against emerging infectious disease viruses.

PubMed

Liu, Jinliang; Dai, Shiyu; Wang, Manli; Hu, Zhihong; Wang, Hualin; Deng, Fei

2016-08-01

Emerging infectious diseases are major threats to human health. Most severe viral disease outbreaks occur in developing regions where health conditions are poor. With increased international travel and business, the possibility of eventually transmitting infectious viruses between different countries is increasing. The most effective approach in preventing viral diseases is vaccination. However, vaccines are not currently available for numerous viral diseases. Virus-like particles (VLPs) are engineered vaccine candidates that have been studied for decades. VLPs are constructed by viral protein expression in various expression systems that promote the selfassembly of proteins into structures resembling virus particles. VLPs have antigenicity similar to that of the native virus, but are non-infectious as they lack key viral genetic material. VLP vaccines have attracted considerable research interest because they offer several advantages over traditional vaccines. Studies have shown that VLP vaccines can stimulate both humoral and cellular immune responses, which may offer effective antiviral protection. Here we review recent developments with VLP-based vaccines for several highly virulent emerging or re-emerging infectious diseases. The infectious agents discussed include RNA viruses from different virus families, such as the Arenaviridae, Bunyaviridae, Caliciviridae, Coronaviridae, Filoviridae, Flaviviridae, Orthomyxoviridae, Paramyxoviridae, and Togaviridae families.

The Epstein-Barr virus lytic protein BZLF1 as a candidate target antigen for vaccine development1

PubMed Central

Hartlage, Alex S.; Liu, Tom; Patton, John T.; Garman, Sabrina L.; Zhang, Xiaoli; Kurt, Habibe; Lozanski, Gerard; Lustberg, Mark E.; Caligiuri, Michael A.; Baiocchi, Robert A.

2015-01-01

The Epstein-Barr virus (EBV) is an oncogenic, γ-herpesvirus associated with a broad spectrum of disease. While most immune-competent individuals can effectivley develop efficient adaptive immune responses to EBV, immunocompromised individuals are at serious risk for developing life threatening diseases such as Hodgkin’s lymphoma and post-transplant lymphoproliferative disorder (PTLD). Given the significant morbidity associated with EBV infection in high-risk populations, there is a need to develop vaccine strategies that restore or enhance EBV-specific immune responses. Here, we identify the EBV immediate-early protein BZLF1 as a potential target antigen for vaccine development. Primary tumors from patients with PTLD and a chimeric human-murine model of EBV-driven lymphoproliferative disorder (EBV-LPD) express BZLF1 protein. Pulsing human dendritic cells (DC) with recombinant BZLF1 followed by incubation with autologous mononuclear cells led to expansion of BZLF1-specific CD8(+) T cells in vitro and primed BZLF1-specific T-cell responses in vivo. In addition, vaccination of hu-PBL-SCID mice with BZLF1-transduced DCs induced specific cellular immunity and significantly prolonged survival from fatal EBV-LPD. These findings identify BZLF1 as a candidate target protein in the immunosurveillance of EBV and provide rationale for considering BZLF1 in vaccine strategies to enhance primary and recall immune responses and potentially prevent EBV-associated diseases. PMID:25735952

Inspecting the Mechanism: A Longitudinal Analysis of Socioeconomic Status Differences in Perceived Influenza Risks, Vaccination Intentions, and Vaccination Behaviors during the 2009-2010 Influenza Pandemic.

PubMed

Maurer, Jürgen

2016-10-01

Influenza vaccination is strongly associated with socioeconomic status, but there is only limited evidence on the respective roles of socioeconomic differences in vaccination intentions versus corresponding differences in follow-through on initial vaccination plans for subsequent socioeconomic differences in vaccine uptake. Nonparametric mean smoothing, linear regression, and probit models were used to analyze longitudinal survey data on perceived influenza risks, behavioral vaccination intentions, and vaccination behavior of adults during the 2009-2010 influenza A/H1N1 ("swine flu") pandemic in the United States. Perceived influenza risks and behavioral vaccination intentions were elicited prior to the availability of H1N1 vaccine using a probability scale question format. H1N1 vaccine uptake was assessed at the end of the pandemic. Education, income, and health insurance coverage displayed positive associations with behavioral intentions to get vaccinated for pandemic influenza while employment was negatively associated with stated H1N1 vaccination intentions. Education and health insurance coverage also displayed significant positive associations with pandemic vaccine uptake. Moreover, behavioral vaccination intentions showed a strong and statistically significant positive partial association with later H1N1 vaccination. Incorporating vaccination intentions in a statistical model for H1N1 vaccine uptake further highlighted higher levels of follow-through on initial vaccination plans among persons with higher education levels and health insurance. Sampling bias, misreporting in self-reported data, and limited generalizability to nonpandemic influenza are potential limitations of the analysis. Closing the socioeconomic gap in influenza vaccination requires multipronged strategies that not only increase vaccination intentions by improving knowledge, attitudes, and beliefs but also facilitate follow-through on initial vaccination plans by improving behavioral

Inspecting the Mechanism: A Longitudinal Analysis of Socioeconomic Status Differences in Perceived Influenza Risks, Vaccination Intentions and Vaccination Behaviors during the 2009-2010 Influenza Pandemic

PubMed Central

Maurer, Jürgen

2015-01-01

Background Influenza vaccination is strongly associated with socioeconomic status, but there is only limited evidence on the respective roles of socioeconomic differences in vaccination intentions vs. corresponding differences in follow through on initial vaccination plans for subsequent socioeconomic differences in vaccine uptake. Methods Nonparametric mean smoothing, linear regression and Probit models were used to analyze longitudinal survey data on perceived influenza risks, behavioral vaccination intentions and vaccination behavior of adults during the 2009-10 influenza A/H1N1 (“Swine Flu”) pandemic in the United States. Perceived influenza risks and behavioral vaccination intentions were elicited prior to the availability of H1N1 vaccine using a probability scale question format. H1N1 vaccine uptake was assessed at the end of the pandemic. Results Education, income and health insurance coverage displayed positive associations with behavioral intentions to get vaccinated for pandemic influenza while employment was negatively associated with stated H1N1 vaccination intentions. Education and health insurance coverage also displayed significant positive associations with pandemic vaccine uptake. Moreover, behavioral vaccination intentions showed a strong and statistically significant positive partial association with later H1N1 vaccination. Incorporating vaccination intentions in a statistical model for H1N1 vaccine uptake further highlighted higher levels of follow through on initial vaccination plans among persons with higher education levels and health insurance. Limitations Sampling bias, misreporting in self-reported data, and limited generalizability to non-pandemic influenza are potential limitations of the analysis. Conclusions Closing the socioeconomic gap in influenza vaccination requires multi-pronged strategies that not only increase vaccination intentions by improving knowledge, attitudes and beliefs but also facilitate follow through on initial

Recent advances in the molecular design of synthetic vaccines

NASA Astrophysics Data System (ADS)

Jones, Lyn H.

2015-12-01

Vaccines have typically been prepared using whole organisms. These are normally either attenuated bacteria or viruses that are live but have been altered to reduce their virulence, or pathogens that have been inactivated and effectively killed through exposure to heat or formaldehyde. However, using whole organisms to elicit an immune response introduces the potential for infections arising from a reversion to a virulent form in live pathogens, unproductive reactions to vaccine components or batch-to-batch variability. Synthetic vaccines, in which a molecular antigen is conjugated to a carrier protein, offer the opportunity to circumvent these problems. This Perspective will highlight the progress that has been achieved in developing synthetic vaccines using a variety of molecular antigens. In particular, the different approaches used to develop conjugate vaccines using peptide/proteins, carbohydrates and other small molecule haptens as antigens are compared.

Vaccination with Eimeria tenella elongation factor-1α recombinant protein induces protective immunity against E. tenella and E. maxima infections.

PubMed

Lin, Rui-Qing; Lillehoj, Hyun S; Lee, Seung Kyoo; Oh, Sungtaek; Panebra, Alfredo; Lillehoj, Erik P

2017-08-30

Avian coccidiosis is caused by multiple species of the apicomplexan protozoan, Eimeria, and is one of the most economically devastating enteric diseases for the poultry industry worldwide. Host immunity to Eimeria infection, however, is relatively species-specific. The ability to immunize chickens against different species of Eimeria using a single vaccine will have a major beneficial impact on commercial poultry production. In this paper, we describe the molecular cloning, purification, and vaccination efficacy of a novel Eimeria vaccine candidate, elongation factor-1α (EF-1α). One day-old broiler chickens were given two subcutaneous immunizations one week apart with E. coli-expressed E. tenella recombinant (r)EF-1α protein and evaluated for protection against challenge infection with E. tenella or E. maxima. rEF-1α-vaccinated chickens exhibited increased body weight gains, decreased fecal oocyst output, and greater serum anti-EF-1α antibody levels following challenge infection with either E. tenella or E. maxima compared with unimmunized controls. Vaccination with EF-1α may represent a new approach to inducing cross-protective immunity against avian coccidiosis in the field. Published by Elsevier B.V.

[The development of therapeutic vaccine for hepatitis C virus].

PubMed

Kimura, Kiminori; Kohara, Michinori

2012-10-01

Chronic hepatitis C caused by infection with the hepatitis C virus(HCV)is a global health problem. HCV causes persistent infection that can lead to chronic liver diseases such as chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. The therapeutic efficacy of antiviral drugs is not optimal in patients with chronic infection; furthermore, an effective vaccine has not yet been developed. To design an effective HCV vaccine, generation of a convenient animal model of HCV infection is necessary. Recently, we used the Cre/loxP switching system to generate an immunocompetent mouse model of HCV expression, thereby enabling the study of host immune responses against HCV proteins. At present vaccine has not yet been shown to be therapeutically effective against chronic HCV infection. We examined the therapeutic effects of a recombinant vaccinia virus(rVV)encoding HCV protein in a mouse model. we generated rVVs for 3 different HCV proteins and found that one of the recombinant viruses encoding a nonstructural protein(rVV-N25)resolved pathological chronic hepatitis C symptoms in the liver. We propose the possibility that rVV-N25 immunization has the potential for development of an effective therapeutic vaccine for HCV induced chronic hepatitis. The utilization of the therapeutic vaccine can protect progress to chronic hepatitis, and as a consequence, leads to eradication of hepatocellular carcinoma. In this paper, we summarized our current study for HCV therapeutic vaccine and review the vaccine development to date.

Development of oral cancer vaccine using recombinant Bifidobacterium displaying Wilms' tumor 1 protein.

PubMed

Kitagawa, Koichi; Oda, Tsugumi; Saito, Hiroki; Araki, Ayame; Gonoi, Reina; Shigemura, Katsumi; Hashii, Yoshiko; Katayama, Takane; Fujisawa, Masato; Shirakawa, Toshiro

2017-06-01

Several types of vaccine-delivering tumor-associated antigens (TAAs) have been developed in basic and clinical research. Wilms' tumor 1 (WT1), identified as a gene responsible for pediatric renal neoplasm, is one of the most promising TAA for cancer immunotherapy. Peptide and dendritic cell-based WT1 cancer vaccines showed some therapeutic efficacy in clinical and pre-clinical studies but as yet no oral WT1 vaccine can be administrated in a simple and easy way. In the present study, we constructed a novel oral cancer vaccine using a recombinant Bifidobacterium longum displaying WT1 protein. B. longum 420 was orally administered into mice inoculated with WT1-expressing tumor cells for 4 weeks to examine anti-tumor effects. To analyze the WT1-specific cellular immune responses to oral B. longum 420, mice splenocytes were isolated and cytokine production and cytotoxic activities were determined. Oral administrations of B. longum 420 significantly inhibited WT1-expressing tumor growth and prolonged survival in mice. Immunohistochemical study and immunological assays revealed that B. longum 420 substantially induced tumor infiltration of CD4 + T and CD8 + T cells, systemic WT1-specific cytokine production, and cytotoxic activity mediated by WT1-epitope specific cytotoxic T lymphocytes, with no apparent adverse effects. Our novel oral cancer vaccine safely induced WT1-specific cellular immunity via activation of the gut mucosal immune system and achieved therapeutic efficacy with several practical advantages over existing non-oral vaccines.

Layer-By-Layer Nanoparticle Vaccines Carrying the G Protein CX3C Motif Protect against RSV Infection and Disease.

PubMed

Jorquera, Patricia A; Oakley, Katie E; Powell, Thomas J; Palath, Naveen; Boyd, James G; Tripp, Ralph A

2015-10-12

Respiratory syncytial virus (RSV) is the single most important cause of serious lower respiratory tract infections in young children; however no effective treatment or vaccine is currently available. Previous studies have shown that therapeutic treatment with a monoclonal antibody (clone 131-2G) specific to the RSV G glycoprotein CX3C motif, mediates virus clearance and decreases leukocyte trafficking to the lungs of RSV-infected mice. In this study, we show that vaccination with layer-by-layer nanoparticles (LbL-NP) carrying the G protein CX3C motif induces blocking antibodies that prevent the interaction of the RSV G protein with the fractalkine receptor (CX3CR1) and protect mice against RSV replication and disease pathogenesis. Peptides with mutations in the CX3C motif induced antibodies with diminished capacity to block G protein-CX3CR1 binding. Passive transfer of these anti-G protein antibodies to mice infected with RSV improved virus clearance and decreased immune cell trafficking to the lungs. These data suggest that vaccination with LbL-NP loaded with the CX3C motif of the RSV G protein can prevent manifestations of RSV disease by preventing the interaction between the G protein and CX3CR1 and recruitment of immune cells to the airways.

Lack of evidence for post-vaccine onset of autoimmune/lymphoproliferative disorders, during a nine-month follow-up in multiply vaccinated Italian military personnel.

PubMed

Ferlito, Claudia; Barnaba, Vincenzo; Abrignani, Sergio; Bombaci, Mauro; Sette, Alessandro; Sidney, John; Biselli, Roberto; Tomao, Enrico; Cattaruzza, Maria Sofia; Germano, Valentina; Biondo, Michela Ileen; Salerno, Gerardo; Lulli, Patrizia; Caporuscio, Sara; Picchianti Diamanti, Andrea; Falco, Mirella; Biselli, Valentina; Cardelli, Patrizia; Autore, Alberto; Lucertini, Elena; De Cesare, Donato Pompeo; Peragallo, Mario Stefano; Lista, Florigio; Martire, Carmela; Salemi, Simonetta; Nisini, Roberto; D'Amelio, Raffaele

2017-08-01

Anecdotal case reports, amplified by mass media and internet-based opinion groups, have recently indicated vaccinations as possibly responsible for autoimmunity/lymphoproliferation development. Multiply vaccinated Italian military personnel (group 1, operating in Italy, group 2, operating in Lebanon) were followed-up for nine months to monitor possible post-vaccine autoimmunity/lymphoproliferation onset. No serious adverse event was noticed in both groups. Multivariate analysis of intergroup differences only showed a significant association between lymphocyte increase and tetanus/diphtheria vaccine administration. A significant post-vaccine decrease in autoantibody positivity was observed. Autoantibodies were also studied by microarray analysis of self-proteins in subjects exposed to ≥4 concurrent vaccinations, without observing significant difference among baseline and one and nine months post-vaccine. Moreover, HLA-A2 subjects have been analyzed for the possible CD8T-cell response to apoptotic self-epitopes, without observing significant difference between baseline and one month post-vaccine. Multiple vaccinations in young adults are safe and not associated to autoimmunity/lymphoproliferation onset during a nine-month-long follow-up. Copyright © 2017 Elsevier Inc. All rights reserved.

Progress toward the Development of a NEAT Protein Vaccine for Anthrax Disease

PubMed Central

Balderas, Miriam A.; Nguyen, Chinh T. Q.; Terwilliger, Austen; Keitel, Wendy A.; Iniguez, Angelina; Torres, Rodrigo; Palacios, Frederico; Goulding, Celia W.

2016-01-01

Bacillus anthracis is a sporulating Gram-positive bacterium that is the causative agent of anthrax and a potential weapon of bioterrorism. The U.S.-licensed anthrax vaccine is made from an incompletely characterized culture supernatant of a nonencapsulated, toxigenic strain (anthrax vaccine absorbed [AVA]) whose primary protective component is thought to be protective antigen (PA). AVA is effective in protecting animals and elicits toxin-neutralizing antibodies in humans, but enthusiasm is dampened by its undefined composition, multishot regimen, recommended boosters, and potential for adverse reactions. Improving next-generation anthrax vaccines is important to safeguard citizens and the military. Here, we report that vaccination with recombinant forms of a conserved domain (near-iron transporter [NEAT]), common in Gram-positive pathogens, elicits protection in a murine model of B. anthracis infection. Protection was observed with both Freund's and alum adjuvants, given subcutaneously and intramuscularly, respectively, with a mixed composite of NEATs. Protection correlated with an antibody response against the NEAT domains and a decrease in the numbers of bacteria in major organs. Anti-NEAT antibodies promote opsonophagocytosis of bacilli by alveolar macrophages. To guide the development of inactive and safe NEAT antigens, we also report the crystal structure of one of the NEAT domains (Hal) and identify critical residues mediating its heme-binding and acquisition activity. These results indicate that we should consider NEAT proteins in the development of an improved antianthrax vaccine. PMID:27647868

Progress toward the Development of a NEAT Protein Vaccine for Anthrax Disease.

PubMed

Balderas, Miriam A; Nguyen, Chinh T Q; Terwilliger, Austen; Keitel, Wendy A; Iniguez, Angelina; Torres, Rodrigo; Palacios, Frederico; Goulding, Celia W; Maresso, Anthony W

2016-12-01

Bacillus anthracis is a sporulating Gram-positive bacterium that is the causative agent of anthrax and a potential weapon of bioterrorism. The U.S.-licensed anthrax vaccine is made from an incompletely characterized culture supernatant of a nonencapsulated, toxigenic strain (anthrax vaccine absorbed [AVA]) whose primary protective component is thought to be protective antigen (PA). AVA is effective in protecting animals and elicits toxin-neutralizing antibodies in humans, but enthusiasm is dampened by its undefined composition, multishot regimen, recommended boosters, and potential for adverse reactions. Improving next-generation anthrax vaccines is important to safeguard citizens and the military. Here, we report that vaccination with recombinant forms of a conserved domain (near-iron transporter [NEAT]), common in Gram-positive pathogens, elicits protection in a murine model of B. anthracis infection. Protection was observed with both Freund's and alum adjuvants, given subcutaneously and intramuscularly, respectively, with a mixed composite of NEATs. Protection correlated with an antibody response against the NEAT domains and a decrease in the numbers of bacteria in major organs. Anti-NEAT antibodies promote opsonophagocytosis of bacilli by alveolar macrophages. To guide the development of inactive and safe NEAT antigens, we also report the crystal structure of one of the NEAT domains (Hal) and identify critical residues mediating its heme-binding and acquisition activity. These results indicate that we should consider NEAT proteins in the development of an improved antianthrax vaccine. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Intranasal delivery of a protein subunit vaccine using a Tobacco Mosaic Virus platform protects against pneumonic plague.

PubMed

Arnaboldi, Paul M; Sambir, Mariya; D'Arco, Christina; Peters, Lauren A; Seegers, Jos F M L; Mayer, Lloyd; McCormick, Alison A; Dattwyler, Raymond J

2016-11-11

Yersinia pestis, one of history's deadliest pathogens, has killed millions over the course of human history. It has attributes that make it an ideal choice to produce mass casualties and is a prime candidate for use as a biological weapon. When aerosolized, Y. pestis causes pneumonic plague, a pneumonia that is 100% lethal if not promptly treated with effective antibiotics. Currently, there is no FDA approved plague vaccine. The current lead vaccine candidate, a parenterally administered protein subunit vaccine comprised of the Y. pestis virulence factors, F1 and LcrV, demonstrated variable levels of protection in primate pneumonic plague models. As the most likely mode of exposure in biological attack with Y. pestis is by aerosol, this raises a question of whether this parenteral vaccine will adequately protect humans against pneumonic plague. In the present study we evaluated two distinct mucosal delivery platforms for the intranasal (IN) administration of LcrV and F1 vaccine proteins, a live bacterial vector, Lactobacillus plantarum, and a Tobacco Mosaic Virus (TMV) based delivery platform. IN administration of L. plantarum expressing LcrV, or TMV-conjugated to LcrV and F1 (TMV-LcrV+TMV-F1) resulted in the similar induction of high titers of IgG antibodies and evidence of proinflammatory cytokine secretion. However, only the TMV-conjugate delivery platform protected against subsequent lethal challenge with Y. pestis. TMV-LcrV+TMV-F1 co-vaccinated mice had no discernable morbidity and no mortality, while mice vaccinated with L. plantarum expressing LcrV or rLcrV+rF1 without TMV succumbed to infection or were only partially protected. Thus, TMV is a suitable mucosal delivery platform for an F1-LcrV subunit vaccine that induces complete protection against pneumonic infection with a lethal dose of Y. pestis in mice. Copyright © 2016 Elsevier Ltd. All rights reserved.

Immunogenicity of recombinant measles vaccine expressing fusion protein of respiratory syncytial virus in cynomolgus monkeys.

PubMed

Sawada, Akihito; Yunomae, Kiyokazu; Nakayama, Tetsuo

2018-02-01

Respiratory syncytial virus (RSV) is a common cause of respiratory infections in infants. Effective vaccines are currently being sought, but no vaccine is thus far available. In our previous study, recombinant AIK-C measles vaccine expressing the RSV fusion protein (MVAIK/RSV/F) was developed and protective immunity against RSV demonstrated in cotton rats. In the present study, the immunogenicity and protective effects were investigated in three cynomolgus monkeys immunized with MVAIK/RSV/F. Neutralizing test antibodies against RSV were detected and no infectious virus was recovered from the lungs of monkeys immunized with MVAIK/RSV/F after challenge. MVAIK/RSV/F has the potential to inhibit RSV infection. © 2018 The Societies and John Wiley & Sons Australia, Ltd.

Immunological Evaluation of Recent MUC1 Glycopeptide Cancer Vaccines

PubMed Central

Hossain, Md Kamal; Wall, Katherine A.

2016-01-01

Aberrantly glycosylated mucin 1 (MUC1) is a recognized tumor-specific antigen on epithelial cell tumors. A wide variety of MUC1 glycopeptide anti-cancer vaccines have been formulated by many research groups. Some researchers have used MUC1 alone as an immunogen whereas other groups used different antigenic carrier proteins such as bovine serum albumin or keyhole limpet hemocyanin for conjugation with MUC1 glycopeptide. A variety of adjuvants have been used with MUC1 glycopeptides to improve their immunogenicity. Fully synthetic multicomponent vaccines have been synthesized by incorporating different T helper cell epitopes and Toll-like receptor agonists. Some vaccine formulations utilized liposomes or nanoparticles as vaccine delivery systems. In this review, we discuss the immunological evaluation of different conjugate or synthetic MUC1 glycopeptide vaccines in different tumor or mouse models that have been published since 2012. PMID:27472370

Phenotypic differences between BCG vaccines at the proteome level.

PubMed

Rodríguez-Alvarez, Mauricio; Mendoza-Hernández, Guillermo; Encarnación, Sergio; Calva, Juan José; López-Vidal, Yolanda

2009-03-01

To contribute to Mycobacterium bovis BCG characterization, two substrains were analyzed using two-dimensional gel electrophoresis (2D-PAGE) and mass spectrometry (MS), based on their protective efficacy in a pulmonary-tuberculosis mouse model. Cell-fraction proteins of BCG Denmark and Phipps substrains were separated into approximately 500 spots in 2D-PAGE. The proteomes were similar in protein number, and isoelectric point (pI) and molecular mass (MM) distribution. Statistical analysis, resulted in 72 spots with no change, and 168 and 90 unique for BCG Phipps or Denmark, respectively. Two hundred and fourteen spots showed changes in intensity of >1-fold, 138 of Denmark, and 76 of Phipps. Seventeen spots were selected for MS-based identification (13 from Phipps and 4 from Denmark), including unique, as well as proteins with changes in intensity. The proteins identified participate in virulence, detoxification, adaptation, lipid metabolism, information pathways, cell wall and cell processes, intermediary metabolism and respiration, or still hypotheticals. Our findings contribute to phenotype characterization of BCG substrains and provide new elements to consider for the design of diagnostic tools, drug targets and a new vaccine against tuberculosis based upon protein expression through quantitative statistical analysis.

Anaphylaxis from the influenza virus vaccine.

PubMed

Coop, Christopher A; Balanon, Synya K; White, Kevin M; Whisman, Bonnie A; Rathkopf, Melinda M

2008-01-01

Allergic reactions to the influenza vaccine are uncommon and usually associated with sensitivity to egg or gelatin. The aim of this study was to report the case of anaphylaxis to the influenza vaccine. Allergy percutaneous skin testing, serum specific IgE testing and IgE immunoblotting were performed to the influenza vaccine, egg, and gelatin. Percutaneous skin testing to the influenza vaccine and gelatin were positive and egg (white, whole, and yolk) was negative. Immunocap serum-specific IgE testing to egg (white, whole, and yolk) and gelatin were negative (<0.35 kU/l). IgE immunoblots were performed with 2 cord blood serums and the patient's serum at a 1:20 dilution against 10 microg of the Fluzone influenza vaccine. The patient's IgE immunoblot showed a protein band at 100 kDa which is similar to the molecular weight of gelatin protein, a 68-kDa protein which is similar to the molecular weight of hemagglutinin protein from the influenza vaccine, and a 45-kDa protein band that is similar to the molecular weight of ovalbumin protein from chicken embryo/egg. Based on clinical symptoms, skin testing, Immunocap testing and immunoblot evaluation, we feel that our patient is allergic to the infectious agent in the influenza vaccine as well as gelatin and ovalbumin in egg. Copyright 2007 S. Karger AG, Basel.

Development of TV003/TV005, a single dose, highly immunogenic live attenuated dengue vaccine; what makes this vaccine different from the Sanofi-Pasteur CYD™ vaccine?

PubMed

Whitehead, Stephen S

2016-01-01

Dengue is caused by four serotype-distinct dengue viruses (DENVs), and developing a multivalent vaccine against dengue has not been straightforward since partial immunity to DENV may predispose to more severe disease upon subsequent DENV infection. The vaccine that is furthest along in development is CYD™, a live attenuated tetravalent vaccine (LATV) produced by Sanofi Pasteur. Although the multi-dose vaccine demonstrated protection against severe dengue, its overall efficacy was limited by DENV serotype, serostatus at vaccination, region and age. The National Institute of Allergy and Infectious Diseases has developed the LATV dengue vaccines TV003/TV005. A single dose of either TV003 or TV005 induced seroconversion to four DENV serotypes in 74-92% (TV003) and 90% (TV005) of flavivirus seronegative adults and elicited near-sterilizing immunity to a second dose of vaccine administered 6-12 months later. The important differences in the structure, infectivity and immune responses to TV003/TV005 are compared with CYD™.

A boosting skin vaccination with dissolving microneedle patch encapsulating M2e vaccine broadens the protective efficacy of conventional influenza vaccines.

PubMed

Zhu, Wandi; Pewin, Winston; Wang, Chao; Luo, Yuan; Gonzalez, Gilbert X; Mohan, Teena; Prausnitz, Mark R; Wang, Bao-Zhong

2017-09-10

The biodegradable microneedle patch (MNP) is a novel technology for vaccine delivery that could improve the immunogenicity of vaccines. To broaden the protective efficiency of conventional influenza vaccines, a new 4M2e-tFliC fusion protein construct containing M2e sequences from different subtypes was generated. Purified fusion protein was encapsulate into MNPs with a biocompatible polymer for use as a boosting vaccine. The results demonstrated that mice receiving a conventional inactivated vaccine followed by a skin-applied dissolving 4M2e-tFliC MNP boost could better maintain the humoral antibody response than that by the conventional vaccine-prime alone. Compared with an intramuscular injection boost, mice receiving the MNP boost showed significantly enhanced cellular immune responses, hemagglutination-inhibition (HAI) titers, and neutralization titers. Increased frequency of antigen-specific plasma cells and long-lived bone marrow plasma cells was detected in the MNP boosted group as well, indicating that skin vaccination with 4M2e-tFliC facilitated a long-term antibody-mediated immunity. The 4M2e-tFliC MNP-boosted group also possessed enhanced protection against high lethal dose challenges against homologous A/PR/8/34 and A/Aichi/2/68 viruses and protection for a majority of immunized mice against a heterologous A/California/07/2009 H1N1 virus. High levels of M2e specific immune responses were observed in the 4M2e-tFliC MNP-boosted group as well. These results demonstrate that a skin-applied 4M2e-tFliC MNP boosting immunization to seasonal vaccine recipients may be a rapid approach for increasing the protective efficacy of seasonal vaccines in response to a significant drift seen in circulating viruses. The results also provide a new perspective for future exploration of universal influenza vaccines. Copyright © 2017 Elsevier B.V. All rights reserved.

Humoral immune response against lipopolysaccharide and cytoplasmic proteins of Brucella abortus in cattle vaccinated with B. abortus S19 or experimentally infected with Yersinia enterocolitica serotype 0:9.

PubMed Central

Baldi, P C; Giambartolomei, G H; Goldbaum, F A; Abdón, L F; Velikovsky, C A; Kittelberger, R; Fossati, C A

1996-01-01

The humoral immune responses against three different antigens of Brucella abortus were monitored by enzyme-linked immunosorbent assay in cattle vaccinated with B. abortus S19 or experimentally infected with Yersinia enterocolitica serotype 0:9. Immunoglobulin G (IgG) and IgM responses against (i) B. abortus lipopolysaccharide (LPS), (ii) total cytoplasmic proteins depleted of LPS (LPS-free CYT), and (iii) B. abortus 18-kDa cytoplasmic protein were measured. Vaccinated animals and Yersinia-infected animals developed high anti-LPS IgM and IgG titers, which overlapped with those obtained with sera from B. abortus 544-infected animals used as positive controls. In contrast, only a slight or negative IgG and IgM response against LPS-free CYT and the 18-kDa protein was detected in vaccinated or Yersinia-infected cattle, although its levels were always significantly lower than those of B. abortus 544-infected animals. These data indicate that cytoplasmic proteins of B. abortus could be useful for the differential diagnosis of bovine brucellosis. PMID:8807216

Expression of rabies glycoprotein and ricin toxin B chain (RGP-RTB) fusion protein in tomato hairy roots: a step towards oral vaccination for rabies.

PubMed

Singh, Ankit; Srivastava, Subhi; Chouksey, Ankita; Panwar, Bhupendra Singh; Verma, Praveen C; Roy, Sribash; Singh, Pradhyumna K; Saxena, Gauri; Tuli, Rakesh

2015-04-01

Transgenic hairy roots of Solanum lycopersicum were engineered to express a recombinant protein containing a fusion of rabies glycoprotein and ricin toxin B chain (rgp-rtxB) antigen under the control of constitutive CaMV35S promoter. Asialofetuin-mediated direct ELISA of transgenic hairy root extracts was performed using polyclonal anti-rabies antibodies (Ab1) and epitope-specific peptidal anti-RGP (Ab2) antibodies which confirmed the expression of functionally viable RGP-RTB fusion protein. Direct ELISA based on asialofetuin-binding activity was used to screen crude protein extracts from five transgenic hairy root lines. Expressions of RGP-RTB fusion protein in different tomato hairy root lines varied between 1.4 and 8 µg in per gram of tissue. Immunoblotting assay of RGP-RTB fusion protein from these lines showed a protein band on monomeric size of ~84 kDa after denaturation. Tomato hairy root line H03 showed highest level of RGP-RTB protein expression (1.14 %) and was used further in bench-top bioreactor for the optimization of scale-up process to produce large quantity of recombinant protein. Partially purified RGP-RTB fusion protein was able to induce the immune response in BALB/c mice after intra-mucosal immunization. In the present investigation, we have not only successfully scaled up the hairy root culture but also established the utility of this system to produce vaccine antigen which subsequently will reduce the total production cost for implementing rabies vaccination programs in developing nations. This study in a way aims to provide consolidated base for low-cost preparation of improved oral vaccine against rabies.

Clostridium difficile chimeric toxin receptor binding domain vaccine induced protection against different strains in active and passive challenge models.

PubMed

Tian, Jing-Hui; Glenn, Gregory; Flyer, David; Zhou, Bin; Liu, Ye; Sullivan, Eddie; Wu, Hua; Cummings, James F; Elllingsworth, Larry; Smith, Gale

2017-07-24

Clostridium difficile is the number one cause of nosocomial antibiotic-associated diarrhea in developed countries. Historically, pathogenesis was attributed two homologous glucosylating toxins, toxin-A (TcdA) and toxin-B (TcdB). Over the past decade, however, highly virulent epidemic strains of C. difficile (B1/NAP1/027) have emerged and are linked to an increase in morbidity and mortality. Increased virulence is attributed to multiple factors including: increased production of A- and B-toxins; production of binary toxin (CDT); and the emergence of more toxic TcdB variants (TcdB (027) ). TcdB (027) is more cytotoxicity to cells; causes greater tissue damage and toxicity in animals; and is antigenically distinct from historical TcdB (TcdB (003) ). Broadly protective vaccines and therapeutic antibody strategies, therefore, may target TcdA, TcdB variants and CDT. To facilitate the generation of multivalent toxin-based C. difficile vaccines and therapeutic antibodies, we have generated fusion proteins constructed from the receptor binding domains (RBD) of TcdA, TcdB (003) , TcdB (027) and CDT. Herein, we describe the development of a trivalent toxin (T-toxin) vaccine (CDTb/TcdB (003) /TcdA) and quadravalent toxin (Q-toxin) vaccine (CDTb/TcB (003) /TcdA/TcdB (027) ) fusion proteins that retain the protective toxin neutralizing epitopes. Active immunization of mice or hamsters with T-toxin or Q-toxin fusion protein vaccines elicited the generation of toxin neutralizing antibodies to each of the toxins. Hamsters immunized with the Q-toxin vaccine were broadly protected against spore challenge with historical C. difficile 630 (toxinotype 0/ribotype 003) and epidemic NAP1 (toxinotype III/ribotype 027) strains. Fully human polyclonal antitoxin IgG was produced by immunization of transgenic bovine with these fusion proteins. In passive transfer studies, mice were protected against lethal toxin challenge. Hamsters treated with human antitoxin IgG were completely protected when

A chimeric alphavirus replicon particle vaccine expressing the hemagglutinin and fusion proteins protects juvenile and infant rhesus macaques from measles.

PubMed

Pan, Chien-Hsiung; Greer, Catherine E; Hauer, Debra; Legg, Harold S; Lee, Eun-Young; Bergen, M Jeff; Lau, Brandyn; Adams, Robert J; Polo, John M; Griffin, Diane E

2010-04-01

Measles remains a major cause of child mortality, in part due to an inability to vaccinate young infants with the current live attenuated virus vaccine (LAV). To explore new approaches to infant vaccination, chimeric Venezuelan equine encephalitis/Sindbis virus (VEE/SIN) replicon particles were used to express the hemagglutinin (H) and fusion (F) proteins of measles virus (MV). Juvenile rhesus macaques vaccinated intradermally with a single dose of VEE/SIN expressing H or H and F proteins (VEE/SIN-H or VEE/SIN-H+F, respectively) developed high titers of MV-specific neutralizing antibody and gamma-interferon (IFN-gamma)-producing T cells. Infant macaques vaccinated with two doses of VEE/SIN-H+F also developed neutralizing antibody and IFN-gamma-producing T cells. Control animals were vaccinated with LAV or with a formalin-inactivated measles vaccine (FIMV). Neutralizing antibody remained above the protective level for more than 1 year after vaccination with VEE/SIN-H, VEE/SIN-H+F, or LAV. When challenged with wild-type MV 12 to 17 months after vaccination, all vaccinated juvenile and infant monkeys vaccinated with VEE/SIN-H, VEE/SIN-H+F, and LAV were protected from rash and viremia, while FIMV-vaccinated monkeys were not. Antibody was boosted by challenge in all groups. T-cell responses to challenge were biphasic, with peaks at 7 to 25 days and at 90 to 110 days in all groups, except for the LAV group. Recrudescent T-cell activity coincided with the presence of MV RNA in peripheral blood mononuclear cells. We conclude that VEE/SIN expressing H or H and F induces durable immune responses that protect from measles and offers a promising new approach for measles vaccination. The viral and immunological factors associated with long-term control of MV replication require further investigation.

Broadly Protective Shigella Vaccine Based on Type III Secretion Apparatus Proteins

PubMed Central

Martinez-Becerra, Francisco J.; Kissmann, Julian M.; Diaz-McNair, Jovita; Choudhari, Shyamal P.; Quick, Amy M.; Mellado-Sanchez, Gabriela; Clements, John D.

2012-01-01

Shigella spp. are food- and waterborne pathogens that cause severe diarrheal and dysenteric disease associated with high morbidity and mortality. Individuals most often affected are children under 5 years of age in the developing world. The existence of multiple Shigella serotypes and the heterogenic distribution of pathogenic strains, as well as emerging antibiotic resistance, require the development of a broadly protective vaccine. All Shigella spp. utilize a type III secretion system (TTSS) to initiate infection. The type III secretion apparatus (TTSA) is the molecular needle and syringe that form the energized conduit between the bacterial cytoplasm and the host cell to transport effector proteins that manipulate cellular processes to benefit the pathogen. IpaB and IpaD form a tip complex atop the TTSA needle and are required for pathogenesis. Because they are common to all virulent Shigella spp., they are ideal candidate antigens for a subunit-based, broad-spectrum vaccine. We examined the immunogenicity and protective efficacy of IpaB and IpaD, alone or combined, coadministered with a double mutant heat-labile toxin (dmLT) from Escherichia coli, used as a mucosal adjuvant, in a mouse model of intranasal immunization and pulmonary challenge. Robust systemic and mucosal antibody- and T cell-mediated immunities were induced against both proteins, particularly IpaB. Mice immunized in the presence of dmLT with IpaB alone or IpaB combined with IpaD were fully protected against lethal pulmonary infection with Shigella flexneri and Shigella sonnei. We provide the first demonstration that the Shigella TTSAs IpaB and IpaD are promising antigens for the development of a cross-protective Shigella vaccine. PMID:22202122

Subunit vaccine candidates against Aeromonas salmonicida in rainbow trout Oncorhynchus mykiss.

PubMed

Marana, Moonika Haahr; Jørgensen, Louise von Gersdorff; Skov, Jakob; Chettri, Jiwan Kumar; Holm Mattsson, Andreas; Dalsgaard, Inger; Kania, Per Walter; Buchmann, Kurt

2017-01-01

Aeromonas salmonicida subsp. salmonicida is the etiological agent of furunculosis and a major fish health problem in salmonid aquaculture worldwide. Injection vaccination with commercial mineral oil-adjuvanted bacterin vaccines has been partly successful in preventing the disease but in Danish rainbow trout (Oncorhynchus mykiss, Walbaum) aquaculture furunculosis outbreaks still occur. In this study we tested the efficacy of experimental subunit vaccines against A. salmonicida infection in rainbow trout. We utilized in silico screening of the proteome of A. salmonicida subsp. salmonicida strain A449 and identified potential protective protein antigens that were tested by in vivo challenge trial. A total of 14 proteins were recombinantly expressed in Escherichia coli and prepared in 3 different subunit vaccine combinations to immunize 3 groups of rainbow trout by intraperitoneal (i.p.) injection. The fish were exposed to virulent A. salmonicida 7 weeks after immunization. To assess the efficacy of the subunit vaccines we evaluated the immune response in fish after immunization and challenge infection by measuring the antibody levels and monitoring the survival of fish in different groups. The survival of fish at 3 weeks after challenge infection showed that all 3 groups of fish immunized with 3 different protein combinations exhibited significantly lower mortalities (17-30%) compared to the control groups (48% and 56%). The ELISA results revealed significantly elevated antibody levels in fish against several protein antigens, which in some cases were positively correlated to the survival.

Vaccines and vaccination for avian influenza in poultry

USDA-ARS?s Scientific Manuscript database

Avian influenza (AI) vaccines have been developed and used to protect poultry and other birds in various countries of the world. Protection is principally mediated by an immune response to the subtype-specific hemagglutinin (HA) protein. AI vaccines prevent clinical signs of disease, death, egg pr...

Unexpected fold in the circumsporozoite protein target of malaria vaccines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doud, Michael B.; Koksal, Adem C.; Mi, Li-Zhi

Circumsporozoite (CS) protein is the major surface component of Plasmodium falciparum sporozoites and is essential for host cell invasion. A vaccine containing tandem repeats, region III, and thrombospondin type-I repeat (TSR) of CS is efficacious in phase III trials but gives only a 35% reduction in severe malaria in the first year postimmunization. We solved crystal structures showing that region III and TSR fold into a single unit, an '{alpha}TSR' domain. The {alpha}TSR domain possesses a hydrophobic pocket and core, missing in TSR domains. CS binds heparin, but {alpha}TSR does not. Interestingly, polymorphic T-cell epitopes map to specialized {alpha}TSR regions.more » The N and C termini are unexpectedly close, providing clues for sporozoite sheath organization. Elucidation of a unique structure of a domain within CS enables rational design of next-generation subunit vaccines and functional and medicinal chemical investigation of the conserved hydrophobic pocket.« less

A new strategy based on SmRho protein loaded chitosan nanoparticles as a candidate oral vaccine against schistosomiasis.

PubMed

Oliveira, Carolina R; Rezende, Cíntia M F; Silva, Marina R; Pêgo, Ana Paula; Borges, Olga; Goes, Alfredo M

2012-01-01

Schistosomiasis is one of the most important neglected tropical diseases and an effective control is unlikely in the absence of improved sanitation and vaccination. A new approach of oral vaccination with alginate coated chitosan nanoparticles appears interesting because their great stability and the ease of target accessibility, besides of chitosan and alginate immunostimulatory properties. Here we propose a candidate vaccine based on the combination of chitosan-based nanoparticles containing the antigen SmRho and coated with sodium alginate. Our results showed an efficient performance of protein loading of nanoparticles before and after coating with alginate. Characterization of the resulting nanoparticles reported a size around 430 nm and a negative zeta potential. In vitro release studies of protein showed great stability of coated nanoparticles in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). Further in vivo studies was performed with different formulations of chitosan nanoparticles and it showed that oral immunization was not able to induce high levels of antibodies, otherwise intramuscular immunization induced high levels of both subtypes IgG1 and IgG2a SmRho specific antibodies. Mice immunized with nanoparticles associated to CpG showed significant modulation of granuloma reaction. Mice from all groups immunized orally with nanoparticles presented significant levels of protection against infection challenge with S. mansoni worms, suggesting an important role of chitosan in inducing a protective immune response. Finally, mice immunized with nanoparticles associated with the antigen SmRho plus CpG had 38% of the granuloma area reduced and also presented 48% of protection against of S. mansoni infection. Taken together, this results support this new strategy as an efficient delivery system and a potential vaccine against schistosomiasis.

Design and testing for a nontagged F1-V fusion protein as vaccine antigen against bubonic and pneumonic plague.

PubMed

Powell, Bradford S; Andrews, Gerard P; Enama, Jeffrey T; Jendrek, Scott; Bolt, Chris; Worsham, Patricia; Pullen, Jeffrey K; Ribot, Wilson; Hines, Harry; Smith, Leonard; Heath, David G; Adamovicz, Jeffrey J

2005-01-01

A two-component recombinant fusion protein antigen was re-engineered and tested as a medical counter measure against the possible biological threat of aerosolized Yersinia pestis. The active component of the proposed subunit vaccine combines the F1 capsular protein and V virulence antigen of Y. pestis and improves upon the design of an earlier histidine-tagged fusion protein. In the current study, different production strains were screened for suitable expression and a purification process was optimized to isolate an F1-V fusion protein absent extraneous coding sequences. Soluble F1-V protein was isolated to 99% purity by sequential liquid chromatography including capture and refolding of urea-denatured protein via anion exchange, followed by hydrophobic interaction, concentration, and then transfer into buffered saline for direct use after frozen storage. Protein identity and primary structure were verified by mass spectrometry and Edman sequencing, confirming a purified product of 477 amino acids and removal of the N-terminal methionine. Purity, quality, and higher-order structure were compared between lots using RP-HPLC, intrinsic fluorescence, CD spectroscopy, and multi-angle light scattering spectroscopy, all of which indicated a consistent and properly folded product. As formulated with aluminum hydroxide adjuvant and administered in a single subcutaneous dose, this new F1-V protein also protected mice from wild-type and non-encapsulated Y. pestis challenge strains, modeling prophylaxis against pneumonic and bubonic plague. These findings confirm that the fusion protein architecture provides superior protection over the former licensed product, establish a foundation from which to create a robust production process, and set forth assays for the development of F1-V as the active pharmaceutical ingredient of the next plague vaccine.

Protection against experimental bubonic and pneumonic plague by a recombinant capsular F1-V antigen fusion protein vaccine.

PubMed

Heath, D G; Anderson, G W; Mauro, J M; Welkos, S L; Andrews, G P; Adamovicz, J; Friedlander, A M

1998-07-01

The current human whole-cell vaccine is ineffective against pneumonic plague caused by typical F1 capsule positive (F1+) strains of Yersinia pestis. The authors found this vaccine to also be ineffective against F1-negative (F1-) Y. pestis strains, which have been isolated from a human case and from rodents. For these reasons, the authors developed a recombinant vaccine composed of a fusion protein of F1 with a second protective immunogen, V antigen. This vaccine protected experimental mice against pneumonic as well as bubonic plague produced by either an F1+ or F1- strain of Y. pestis, gave better protection than F1 or V alone against the F1+ strain, and may provide the basis for an improved human plague vaccine.

Prime-boost and recombinant protein vaccination strategies using Sm-p80 protects against Schistosoma mansoni infection in the mouse model to levels previously attainable only by the irradiated cercarial vaccine

PubMed Central

Ahmad, Gul; Zhang, Weidong; Torben, Workineh; Haskins, Chad; Diggs, Sue; Noor, Zahid; Le, Loc

2009-01-01

Advent of an effective schistosome vaccine would contribute significantly toward reducing the disease spectrum and transmission of schistosomiasis. We have targeted a functionally important antigen, Sm-p80, as a vaccine candidate because of its consistent immunogenicity, protective and antifecundity potentials, and important role in the immune evasion process. In this study, we report that using two vaccination approaches (prime boost and recombinant protein), Sm-p80-based vaccine formulation(s) confer up to 70% reduction in worm burden in mice. Animals immunized with the vaccine exhibited a decrease in egg production by up to 75%. The vaccine elicited strong immune responses that included IgM, IgA, and IgG (IgG1, IgG2a, IgG2b, and IgG3) in vaccinated animals. Splenocytes proliferated in response to Sm-p80 produced Th1 and Th17 response enhancing cytokines. These results again emphasize the potential of Sm-p80 as a viable vaccine candidate for schistosomiasis. PMID:19809833

DNA vaccines co-expressing GP5 and M proteins of porcine reproductive and respiratory syndrome virus (PRRSV) display enhanced immunogenicity.

PubMed

Jiang, Yunbo; Xiao, Shaobo; Fang, Liurong; Yu, Xiaolan; Song, Yunfeng; Niu, Chuanshuang; Chen, Huanchun

2006-04-05

The two major membrane-associated proteins of porcine reproductive and respiratory syndrome virus (PRRSV), GP5 and M (encoded by ORF5 and ORF6 genes, respectively), are associated as disulfide-linked heterodimers (GP5/M) in the virus particle. In the present study, three different DNA vaccine constructs, expressing GP5 alone (pCI-ORF5), M alone (pCI-ORF6) or GP5 and M proteins simultaneously (pCI-ORF5/ORF6), were constructed. In vitro, the co-expressed GP5 and M proteins could form heterodimeric complexes in transfected cells and heterodimerization altered the subcellular localization of GP5. The immunogenicities of these DNA vaccine constructs were firstly investigated in a mouse model. Mice inoculated with pCI-ORF5/ORF6 developed PRRSV-specific neutralizing antibodies at 6 and 8 weeks after primary immunization. However, only some mice developed low levels of neutralizing antibodies in groups immunized with pCI-ORF5 or pCI-ORF6. The highest lymphocyte proliferation responses were also observed in mice immunized with pCI-ORF5/ORF6. Interestingly, significantly enhanced GP5-specific ELISA antibody could be detected in mice immunized with pCI-ORF5/ORF6 compared to mice immunized with pCI-ORF5. The immunogenicities of pCI-ORF5/ORF6 were further evaluated in piglets (the natural host) and all immunized piglets developed neutralizing antibodies at 10 weeks after primary immunization, whereas there was no detectable neutralizing antibodies in piglets immunized with pCI-ORF5. These results indicate that the formation of GP5/M heterodimers may be involved in post-translational modification and transport of GP5 and may play an important role in immune responses against PRRSV infection. More importantly, co-expression of GP5 and M protein in heterodimers can significantly improve the potency of DNA vaccination and could be used as a strategy to develop a new generation of vaccines against PRRSV.

Meningococcal vaccine development--from glycoconjugates against MenACWY to proteins against MenB--potential for broad protection against meningococcal disease.

PubMed

Dull, Peter M; McIntosh, E David

2012-05-30

Novartis Vaccines has a long-standing research and development interest in the prevention of invasive meningococcal disease. From the initial licensure of the monovalent meningococcal C glycoconjugate vaccine, Menjugate(®), in response to the emergence of a virulent serogroup C ST-11 strain in the United Kingdom to the more recent development and licensure of a quadrivalent meningococcal ACWY glycoconjugate vaccine, Menveo(®), Novartis has a continuing commitment to the development of more effective tools for the control of meningococcal disease. Menveo is now licensed for use in adolescents and adults in over 50 countries and results from phase III studies have shown the vaccine to be well-tolerated and highly immunogenic in infants with vaccination beginning from 2 months of age. The 'holy grail' of meningococcal disease control is a broadly protective vaccine against serogroup B (MenB), preferably a vaccine that protects all age groups including infants. As the serogroup B capsule is poorly immunogenic, efforts over the past 40 years have focused on identifying conserved proteins expressed on the bacterial surface that elicit bactericidal antibodies. Novartis has approached this problem utilizing genomic tools to identify proteins meeting these criteria in a process now known as 'reverse vaccinology'[1]. This process has resulted in a novel multicomponent MenB vaccine (4CMenB) that consists of four major immunogenic components (three subcapsular MenB protein antigens plus outer membrane vesicles (OMVs) which themselves provide multiple subcapsular antigens, the immunodominant one being PorA). These all induce bactericidal antibodies against the antigens that are important in determining the survival, function, and virulence of the meningococci. Phase II studies of 4CMenB have been completed and have demonstrated that the vaccine is highly immunogenic against reference meningococcal strains selected to support licensure. Post-vaccination sera from clinical

Comparative effectiveness of different strategies of oral cholera vaccination in bangladesh: a modeling study.

PubMed

Dimitrov, Dobromir T; Troeger, Christopher; Halloran, M Elizabeth; Longini, Ira M; Chao, Dennis L

2014-12-01

Killed, oral cholera vaccines have proven safe and effective, and several large-scale mass cholera vaccination efforts have demonstrated the feasibility of widespread deployment. This study uses a mathematical model of cholera transmission in Bangladesh to examine the effectiveness of potential vaccination strategies. We developed an age-structured mathematical model of cholera transmission and calibrated it to reproduce the dynamics of cholera in Matlab, Bangladesh. We used the model to predict the effectiveness of different cholera vaccination strategies over a period of 20 years. We explored vaccination programs that targeted one of three increasingly focused age groups (the entire vaccine-eligible population of age one year and older, children of ages 1 to 14 years, or preschoolers of ages 1 to 4 years) and that could occur either as campaigns recurring every five years or as continuous ongoing vaccination efforts. Our modeling results suggest that vaccinating 70% of the population would avert 90% of cholera cases in the first year but that campaign and continuous vaccination strategies differ in effectiveness over 20 years. Maintaining 70% coverage of the population would be sufficient to prevent sustained transmission of endemic cholera in Matlab, while vaccinating periodically every five years is less effective. Selectively vaccinating children 1-14 years old would prevent the most cholera cases per vaccine administered in both campaign and continuous strategies. We conclude that continuous mass vaccination would be more effective against endemic cholera than periodic campaigns. Vaccinating children averts more cases per dose than vaccinating all age groups, although vaccinating only children is unlikely to control endemic cholera in Bangladesh. Careful consideration must be made before generalizing these results to other regions.

Comparison of the immunogenicity and protection against bovine tuberculosis following immunization by BCG-priming and boosting with adenovirus or protein based vaccines.

PubMed

Dean, G; Whelan, A; Clifford, D; Salguero, F J; Xing, Z; Gilbert, S; McShane, H; Hewinson, R G; Vordermeier, M; Villarreal-Ramos, B

2014-03-05

There is a requirement for vaccines or vaccination strategies that confer better protection against TB than the current live attenuated Mycobacterium bovis Bacillus Calmette-Guerin (BCG) vaccine for use in cattle. Boosting with recombinant viral vectors expressing mycobacterial proteins, such as Ag85A, has shown a degree of promise as a strategy for improving on the protection afforded by BCG. Experiments in small animal models have indicated that broadening the immune response to include mycobacterial antigens other than Ag85A, such as Rv0288, induced by boosting with Ad5 constructs has a direct effect on the protection afforded against TB. Here, we compared the immunogenicity and protection against challenge with M. bovis afforded by boosting BCG-vaccinated cattle with a human type 5 (Ad5)-based vaccine expressing the mycobacterial antigens Ag85A (Ad5-85A); or Ag85A, Rv0251, Rv0287 and Rv0288 (Ad5-TBF); or with protein TBF emulsified in adjuvant (Adj-TBF). Boosting with TBF broaden the immune response. The kinetics of Ad5-TBF and Adj-TBF were shown to be different, with effector T cell responses from the latter developing more slowly but being more durable than those induced by Ad5-TBF. No increase in protection compared to BCG alone was afforded by Ad5-TBF or Adj-TBF by gross pathology or bacteriology. Using histopathology, as a novel parameter of protection, we show that boosting BCG vaccinated cattle with Ad5-85A induced significantly better protection than BCG alone. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Immunopotentiation of outer membrane protein through anti-idiotype Pasteurella multocida vaccine in rabbits.

PubMed

Arif, Javid; Rahman, Sajjad-Ur; Arshad, Muhammad; Akhtar, Pervez

2013-11-01

Pasteurella multocida was isolated from cattle affected with haemorrhagic septicaemia and characterized on the basis of morphological, cultural and biochemical tests. Bacterial outer membrane proteins (OMPs) were extracted with 1% Sarkosyl method. P. multocida anti-idiotype vaccine prepared from OMPs (21.3 mg per 100 ml), was evaluated and compared with bacterin supplemented with 10% OMPs and plain alum-adsorbed bacterin in rabbit models. It was observed that OMPs-anti-idiotype vaccine induced high levels of antibody titres (geomean titres -GMT) detected using indirect haemagglutination (IHA) test. The OMPs anti-idiotype antibody titres of 168.9 GMT were obtained to 42.2 GMT in OMPs supplemented bacterin on 21 days post vaccination, while the plain bacterin had the least titre of 27.9 GMT. The OMPs-anti-idiotype vaccine provoked better immunogenic response in terms of highest GMT titres and long lasting effect in rabbits and 100% protection against the challenge with homologous strain of P. multocida,while 88% protection was obtained in rabbits, given OMPs supplemented bacterin. Copyright © 2013 The International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

Evaluation of a Plasmodium-Specific Carrier Protein To Enhance Production of Recombinant Pfs25, a Leading Transmission-Blocking Vaccine Candidate.

PubMed

Parzych, Elizabeth M; Miura, Kazutoyo; Ramanathan, Aarti; Long, Carole A; Burns, James M

2018-01-01

Challenges with the production and suboptimal immunogenicity of malaria vaccine candidates have slowed the development of a Plasmodium falciparum multiantigen vaccine. Attempting to resolve these issues, we focused on the use of highly immunogenic merozoite surface protein 8 (MSP8) as a vaccine carrier protein. Previously, we showed that a genetic fusion of the C-terminal 19-kDa fragment of merozoite surface protein 1 (MSP1 19 ) to P. falciparum MSP8 ( Pf MSP8) facilitated antigen production and folding and the induction of neutralizing antibodies to conformational B cell epitopes of MSP1 19 Here, using the Pf MSP1/8 construct, we further optimized the recombinant Pf MSP8 (r Pf MSP8) carrier by the introduction of two cysteine-to-serine substitutions (CΔS) to improve the yield of the monomeric product. We then sought to test the broad applicability of this approach using the transmission-blocking vaccine candidate Pf s25. The production of r Pf s25-based vaccines has presented challenges. Antibodies directed against the four highly constrained epidermal growth factor (EGF)-like domains of Pf s25 block sexual-stage development in mosquitoes. The sequence encoding mature Pf s25 was codon harmonized for expression in Escherichia coli We produced a r Pf s25- Pf MSP8 fusion protein [r Pf s25/8(CΔS)] as well as unfused, mature r Pf s25. r Pf s25 was purified with a modest yield but required the incorporation of refolding protocols to obtain a proper conformation. In comparison, chimeric r Pf s25/8(CΔS) was expressed and easily purified, with the Pf s25 domain bearing the proper conformation without renaturation. Both antigens were immunogenic in rabbits, inducing IgG that bound native Pf s25 and exhibited potent transmission-reducing activity. These data further demonstrate the utility of Pf MSP8 as a parasite-specific carrier protein to enhance the production of complex malaria vaccine targets. Copyright © 2017 American Society for Microbiology.

Nanoparticle-based B-cell targeting vaccines: Tailoring of humoral immune responses by functionalization with different TLR-ligands.

PubMed

Zilker, Claudia; Kozlova, Diana; Sokolova, Viktoriya; Yan, Huimin; Epple, Matthias; Überla, Klaus; Temchura, Vladimir

2017-01-01

Induction of an appropriate type of humoral immune response during vaccination is essential for protection against viral and bacterial infections. We recently observed that biodegradable calcium phosphate (CaP) nanoparticles coated with proteins efficiently targeted and activated naïve antigen-specific B-cells in vitro. We now compared different administration routes for CaP-nanoparticles and demonstrated that intramuscular immunization with such CaP-nanoparticles induced stronger immune responses than immunization with monovalent antigen. Additional functionalization of the CaP-nanoparticles with TRL-ligands allowed modulating the IgG subtype response and the level of mucosal IgA antibodies. CpG-containing CaP-nanoparticles were as immunogenic as a virus-like particle vaccine. Functionalization of CaP-nanoparticles with T-helper cell epitopes or CpG also allowed overcoming lack of T-cell help. Thus, our results indicate that CaP-nanoparticle-based B-cell targeting vaccines functionalized with TLR-ligands can serve as a versatile platform for efficient induction and modulation of humoral immune responses in vivo. Copyright © 2016 Elsevier Inc. All rights reserved.

Broadly neutralizing epitopes in the Plasmodium vivax vaccine candidate Duffy Binding Protein

DOE PAGES

Chen, Edwin; Salinas, Nichole D.; Huang, Yining; ...

2016-05-18

Plasmodium vivax Duffy Binding Protein (PvDBP) is the most promising vaccine candidate for P. vivax malaria. The polymorphic nature of PvDBP induces strain-specific immune responses, however, and the epitopes of broadly neutralizing antibodies are unknown. These features hamper the rational design of potent DBP-based vaccines and necessitate the identification of globally conserved epitopes. Using X-ray crystallography, small-angle X-ray scattering, hydrogen-deuterium exchange mass spectrometry, and mutational mapping, we have defined epitopes for three inhibitory mAbs (mAbs 2D10, 2H2, and 2C6) and one noninhibitory mAb (3D10) that engage DBP. These studies expand the currently known inhibitory epitope repertoire by establishing protective motifsmore » in subdomain three outside the receptor-binding and dimerization residues of DBP, and introduce globally conserved protective targets. All of the epitopes are highly conserved among DBP alleles. In conclusion, the identification of broadly conserved epitopes of inhibitory antibodies provides critical motifs that should be retained in the next generation of potent vaccines for P. vivax malaria.« less

Broadly neutralizing epitopes in the Plasmodium vivax vaccine candidate Duffy Binding Protein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Edwin; Salinas, Nichole D.; Huang, Yining

Plasmodium vivax Duffy Binding Protein (PvDBP) is the most promising vaccine candidate for P. vivax malaria. The polymorphic nature of PvDBP induces strain-specific immune responses, however, and the epitopes of broadly neutralizing antibodies are unknown. These features hamper the rational design of potent DBP-based vaccines and necessitate the identification of globally conserved epitopes. Using X-ray crystallography, small-angle X-ray scattering, hydrogen-deuterium exchange mass spectrometry, and mutational mapping, we have defined epitopes for three inhibitory mAbs (mAbs 2D10, 2H2, and 2C6) and one noninhibitory mAb (3D10) that engage DBP. These studies expand the currently known inhibitory epitope repertoire by establishing protective motifsmore » in subdomain three outside the receptor-binding and dimerization residues of DBP, and introduce globally conserved protective targets. All of the epitopes are highly conserved among DBP alleles. In conclusion, the identification of broadly conserved epitopes of inhibitory antibodies provides critical motifs that should be retained in the next generation of potent vaccines for P. vivax malaria.« less

Combined prime-boost vaccination against tick-borne encephalitis (TBE) using a recombinant vaccinia virus and a bacterial plasmid both expressing TBE virus non-structural NS1 protein

PubMed Central

Aleshin, SE; Timofeev, AV; Khoretonenko, MV; Zakharova, LG; Pashvykina, GV; Stephenson, JR; Shneider, AM; Altstein, AD

2005-01-01

Background Heterologous prime-boost immunization protocols using different gene expression systems have proven to be successful tools in protecting against various diseases in experimental animal models. The main reason for using this approach is to exploit the ability of expression cassettes to prime or boost the immune system in different ways during vaccination procedures. The purpose of the project was to study the ability of recombinant vaccinia virus (VV) and bacterial plasmid, both carrying the NS1 gene from tick-borne encephalitis (TBE) virus under the control of different promoters, to protect mice against lethal challenge using a heterologous prime-boost vaccination protocol. Results The heterologous prime-boost vaccination protocol, using a VV recombinant and bacterial plasmid, both containing the NS1 TBE virus protein gene under the control of different promoters, achieved a high level of protection in mice against lethal challenge with a highly pathogenic TBE virus strain. No signs of pronounced TBE infection were detected in the surviving animals. Conclusion Heterologous prime-boost vaccination protocols using recombinant VV and bacterial plasmids could be used for the development of flavivirus vaccines. PMID:16076390

A Novel Malaria Vaccine Candidate Antigen Expressed in Tetrahymena thermophila

PubMed Central

Eleni-Muus, Janna; Aldag, Ingo; Samuel, Kay; Creasey, Alison M.; Hartmann, Marcus W. W.; Cavanagh, David R.

2014-01-01

Development of effective malaria vaccines is hampered by the problem of producing correctly folded Plasmodium proteins for use as vaccine components. We have investigated the use of a novel ciliate expression system, Tetrahymena thermophila, as a P. falciparum vaccine antigen platform. A synthetic vaccine antigen composed of N-terminal and C-terminal regions of merozoite surface protein-1 (MSP-1) was expressed in Tetrahymena thermophila. The recombinant antigen was secreted into the culture medium and purified by monoclonal antibody (mAb) affinity chromatography. The vaccine was immunogenic in MF1 mice, eliciting high antibody titers against both N- and C-terminal components. Sera from immunized animals reacted strongly with P. falciparum parasites from three antigenically different strains by immunofluorescence assays, confirming that the antibodies produced are able to recognize parasite antigens in their native form. Epitope mapping of serum reactivity with a peptide library derived from all three MSP-1 Block 2 serotypes confirmed that the MSP-1 Block 2 hybrid component of the vaccine had effectively targeted all three serotypes of this polymorphic region of MSP-1. This study has successfully demonstrated the use of Tetrahymena thermophila as a recombinant protein expression platform for the production of malaria vaccine antigens. PMID:24489871

Alteration of the Tumor Stroma Using a Consensus DNA Vaccine Targeting Fibroblast Activation Protein (FAP) Synergizes with Antitumor Vaccine Therapy in Mice.

PubMed

Duperret, Elizabeth K; Trautz, Aspen; Ammons, Dylan; Perales-Puchalt, Alfredo; Wise, Megan C; Yan, Jian; Reed, Charles; Weiner, David B

2018-03-01

Purpose: Fibroblast activation protein (FAP) is overexpressed in cancer-associated fibroblasts and is an interesting target for cancer immune therapy, with prior studies indicating a potential to affect the tumor stroma. Our aim was to extend this earlier work through the development of a novel FAP immunogen with improved capacity to break tolerance for use in combination with tumor antigen vaccines. Experimental Design: We used a synthetic consensus (SynCon) sequence approach to provide MHC class II help to support breaking of tolerance. We evaluated immune responses and antitumor activity of this novel FAP vaccine in preclinical studies, and correlated these findings to patient data. Results: This SynCon FAP DNA vaccine was capable of breaking tolerance and inducing both CD8 + and CD4 + immune responses. In genetically diverse, outbred mice, the SynCon FAP DNA vaccine was superior at breaking tolerance compared with a native mouse FAP immunogen. In several tumor models, the SynCon FAP DNA vaccine synergized with other tumor antigen-specific DNA vaccines to enhance antitumor immunity. Evaluation of the tumor microenvironment showed increased CD8 + T-cell infiltration and a decreased macrophage infiltration driven by FAP immunization. We extended this to patient data from The Cancer Genome Atlas, where we find high FAP expression correlates with high macrophage and low CD8 + T-cell infiltration. Conclusions: These results suggest that immune therapy targeting tumor antigens in combination with a microconsensus FAP vaccine provides two-fisted punch-inducing responses that target both the tumor microenvironment and tumor cells directly. Clin Cancer Res; 24(5); 1190-201. ©2018 AACR . ©2018 American Association for Cancer Research.

Strategic priorities for respiratory syncytial virus (RSV) vaccine development

PubMed Central

Anderson, L.J.; Dormitzer, P.R.; Nokes, D.J.; Rappuoli, R.; Roca, A.; Graham, B.S.

2013-01-01

Although RSV has been a high priority for vaccine development, efforts to develop a safe and effective vaccine have yet to lead to a licensed product. Clinical and epidemiologic features of RSV disease suggest there are at least 4 distinct target populations for vaccines, the RSV naïve young infant, the RSV naïve child ≥6 months of age, pregnant women (to provide passive protection to newborns), and the elderly. These target populations raise different safety and efficacy concerns and may require different vaccination strategies. The highest priority target population is the RSV naïve child. The occurrence of serious adverse events associated with the first vaccine candidate for young children, formalin inactivated RSV (FI-RSV), has focused vaccine development for the young RSV naïve child on live virus vaccines. Enhanced disease is not a concern for persons previously primed by a live virus infection. A variety of live-attenuated viruses have been developed with none yet achieving licensure. New live-attenuated RSV vaccines are being developed and evaluated that maybe sufficiently safe and efficacious to move to licensure. A variety of subunit vaccines are being developed and evaluated primarily for adults in whom enhanced disease is not a concern. An attenuated parainfluenza virus 3 vector expressing the RSV F protein was evaluated in RSV naïve children. Most of these candidate vaccines have used the RSV F protein in various vaccine platforms including virus-like particles, nanoparticles, formulated with adjuvants, and expressed by DNA or virus vectors. The other surface glycoprotein, the G protein, has also been used in candidate vaccines. We now have tools to make and evaluate a wide range of promising vaccines. Costly clinical trials in the target population are needed to evaluate and select candidate vaccines for advancement to efficacy trials. Better data on RSV-associated mortality in developing countries, better estimates of the risk of long term

Approaches and Perspectives for Development of African Swine Fever Virus Vaccines

PubMed Central

Arias, Marisa; de la Torre, Ana; Dixon, Linda; Gallardo, Carmina; Laddomada, Alberto; Martins, Carlos; Parkhouse, R. Michael; Revilla, Yolanda; Rodriguez, Fernando; Sanchez-Vizcaino, Jose-Manuel

2017-01-01

African swine fever (ASF) is a complex disease of swine, caused by a large DNA virus belonging to the family Asfarviridae. The disease shows variable clinical signs, with high case fatality rates, up to 100%, in the acute forms. ASF is currently present in Africa and Europe where it circulates in different scenarios causing a high socio-economic impact. In most affected regions, control has not been effective in part due to lack of a vaccine. The availability of an effective and safe ASFV vaccines would support and enforce control–eradication strategies. Therefore, work leading to the rational development of protective ASF vaccines is a high priority. Several factors have hindered vaccine development, including the complexity of the ASF virus particle and the large number of proteins encoded by its genome. Many of these virus proteins inhibit the host’s immune system thus facilitating virus replication and persistence. We review previous work aimed at understanding ASFV–host interactions, including mechanisms of protective immunity, and approaches for vaccine development. These include live attenuated vaccines, and “subunit” vaccines, based on DNA, proteins, or virus vectors. In the shorter to medium term, live attenuated vaccines are the most promising and best positioned candidates. Gaps and future research directions are evaluated. PMID:28991171

A Novel Heat Shock Protein 70-based Vaccine Prepared from DC-Tumor Fusion Cells.

PubMed

Weng, Desheng; Calderwood, Stuart K; Gong, Jianlin

2018-01-01

We have developed an enhanced molecular chaperone-based vaccine through rapid isolation of Hsp70 peptide complexes after the fusion of tumor and dendritic cells (Hsp70.PC-F). In this approach, the tumor antigens are introduced into the antigen processing machinery of dendritic cells through the cell fusion process and thus we can obtain antigenic tumor peptides or their intermediates that have been processed by dendritic cells. Our results show that Hsp70.PC-F has increased immunogenicity compared to preparations from tumor cells alone and therefore constitutes an improved formulation of chaperone protein-based tumor vaccine.

Comparative Effectiveness of Different Strategies of Oral Cholera Vaccination in Bangladesh: A Modeling Study

PubMed Central

Dimitrov, Dobromir T.; Troeger, Christopher; Halloran, M. Elizabeth; Longini, Ira M.; Chao, Dennis L.

2014-01-01

Background Killed, oral cholera vaccines have proven safe and effective, and several large-scale mass cholera vaccination efforts have demonstrated the feasibility of widespread deployment. This study uses a mathematical model of cholera transmission in Bangladesh to examine the effectiveness of potential vaccination strategies. Methods & Findings We developed an age-structured mathematical model of cholera transmission and calibrated it to reproduce the dynamics of cholera in Matlab, Bangladesh. We used the model to predict the effectiveness of different cholera vaccination strategies over a period of 20 years. We explored vaccination programs that targeted one of three increasingly focused age groups (the entire vaccine-eligible population of age one year and older, children of ages 1 to 14 years, or preschoolers of ages 1 to 4 years) and that could occur either as campaigns recurring every five years or as continuous ongoing vaccination efforts. Our modeling results suggest that vaccinating 70% of the population would avert 90% of cholera cases in the first year but that campaign and continuous vaccination strategies differ in effectiveness over 20 years. Maintaining 70% coverage of the population would be sufficient to prevent sustained transmission of endemic cholera in Matlab, while vaccinating periodically every five years is less effective. Selectively vaccinating children 1–14 years old would prevent the most cholera cases per vaccine administered in both campaign and continuous strategies. Conclusions We conclude that continuous mass vaccination would be more effective against endemic cholera than periodic campaigns. Vaccinating children averts more cases per dose than vaccinating all age groups, although vaccinating only children is unlikely to control endemic cholera in Bangladesh. Careful consideration must be made before generalizing these results to other regions. PMID:25473851

Self-assembly of virus-like particles of canine parvovirus capsid protein expressed from Escherichia coli and application as virus-like particle vaccine.

PubMed

Xu, Jin; Guo, Hui-Chen; Wei, Yan-Quan; Dong, Hu; Han, Shi-Chong; Ao, Da; Sun, De-Hui; Wang, Hai-Ming; Cao, Sui-Zhong; Sun, Shi-Qi

2014-04-01

Canine parvovirus disease is an acute infectious disease caused by canine parvovirus (CPV). Current commercial vaccines are mainly attenuated and inactivated; as such, problems concerning safety may occur. To resolve this problem, researchers developed virus-like particles (VLPs) as biological nanoparticles resembling natural virions and showing high bio-safety. This property allows the use of VLPs for vaccine development and mechanism studies of viral infections. Tissue-specific drug delivery also employs VLPs as biological nanomaterials. Therefore, VLPs derived from CPV have a great potential in medicine and diagnostics. In this study, small ubiquitin-like modifier (SUMO) fusion motif was utilized to express a whole, naturalVP2 protein of CPV in Escherichia coli. After the cleavage of the fusion motif, the CPV VP2 protein has self-assembled into VLPs. The VLPs had a size and shape that resembled the authentic virus capsid. However, the self-assembly efficiency of VLPs can be affected by different pH levels and ionic strengths. The mice vaccinated subcutaneously with CPV VLPs and CPV-specific immune responses were compared with those immunized with the natural virus. This result showed that VLPs can effectively induce anti-CPV specific antibody and lymphocyte proliferation as a whole virus. This result further suggested that the antigen epitope of CPV was correctly present on VLPs, thereby showing the potential application of a VLP-based CPV vaccine.

The Health Economic Impact of Universal Infant Vaccination with the 10-Valent Pneumococcal Nontypeable Haemophilus influenzae Protein D Conjugate Vaccine as Compared with 13-Valent Pneumococcal Conjugate Vaccine in Hong Kong.

PubMed

Lee, Kenneth K C; Chia Wu, David Bin; Topachevskyi, Oleksandr; Delgleize, Emmanuelle; DeAntonio, Rodrigo

2013-05-01

Pneumococcal universal vaccination in Hong Kong was introduced in 2009. We assessed the health and economic impact of the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine (PCV-10) compared with the current 13-valent pneumococcal conjugate vaccine (PCV-13) recommended for Hong Kong in 2011, providing new elements to be considered by public health authorities in the future decision-making process for pneumococcal vaccines in this country. An analytical model was used to estimate the annual economic and health outcomes of invasive pneumococcal disease (IPD), community-acquired pneumonia, and acute otitis media (AOM), including nontypeable H. influenzae-related AOM, for a birth cohort in Hong Kong from the payer perspective with a 10-year horizon. Clinical impact including morbidity-mortality, quality-adjusted life-years (QALYs), incremental costs, and cost-effectiveness comparing PCV-10 and PCV-13 were estimated. Probabilistic sensitivity analyses by using alternate scenarios were performed. Model projections indicate that PCV-13 and PCV-10 have approximately equivalent impact on the prevention of deaths caused by IPD and pneumonia. PCV-13 is projected to prevent 6 additional cases of IPD, whereas PCV-10 is projected to prevent 13,229 additional AOM cases and 101 additional QALYs. For the base case, PCV-10 vaccination is estimated to save 44.6 million Hong Kong dollars (34.1 million Hong Kong dollars discounted). Sensitivity analysis indicated that PCV-10 would generate more QALYs and save costs as compared with PCV-13. Universal infant vaccination with new available pneumococcal vaccines is expected to generate a significant additional impact on reducing the burden of pneumococcal diseases in Hong Kong. PCV-10 vaccination would be potentially a cost-saving strategy compared with PCV-13 vaccination, generating better cost offsets and higher QALY gains. Copyright © 2013 International Society for Pharmacoeconomics and Outcomes

Vaccines are different: A systematic review of budget impact analyses of vaccines.

PubMed

Loze, Priscilla Magalhaes; Nasciben, Luciana Bertholim; Sartori, Ana Marli Christovam; Itria, Alexander; Novaes, Hillegonda Maria Dutilh; de Soárez, Patrícia Coelho

2017-05-15

Several countries require manufacturers to present a budget impact analysis (BIA), together with a cost-effectiveness analysis, to support national funding requests. However, guidelines for conducting BIA of vaccines are scarce. To analyze the methodological approaches used in published budget impact analysis (BIA) of vaccines, discussing specific methodological issues related to vaccines. This systematic review of the literature on BIA of vaccines was carried out in accordance with the Centre for Reviews and Dissemination - CRD guidelines. We searched multiple databases: MedLine, Embase, Biblioteca Virtual de Saúde (BVS), Cochrane Library, DARE Database, NHS Economic Evaluation Database (NHS EED), HTA Database (via Centre for Reviews and Dissemination - CRD), and grey literature. Two researchers, working independently, selected the studies and extracted the data. The methodology quality of individual studies was assessed using the ISPOR 2012 Budget Impact Analysis Good Practice II Task Force. A qualitative narrative synthesis was conducted. Twenty-two studies were reviewed. The most frequently evaluated vaccines were pneumococcal (41%), influenza (23%) and rotavirus (18%). The target population was stated in 21 studies (95%) and the perspective was clear in 20 (91%). Only 36% reported the calculations used to complete the BIA, 27% informed the total and disaggregated costs for each time period, and 9% showed the change in resource use for each time period. More than half of the studies (55%, n=12) reported less than 50% of the items recommended in the checklist. The production of BIA of vaccines has increased from 2009. The report of the methodological steps was unsatisfactory, making it difficult to assess the validity of the results presented. Vaccines specific issues should be discussed in international guidelines for BIA of vaccines, to improve the quality of the studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Genetic variation in potential Giardia vaccine candidates cyst wall protein 2 and α1-giardin.

PubMed

Radunovic, Matej; Klotz, Christian; Saghaug, Christina Skår; Brattbakk, Hans-Richard; Aebischer, Toni; Langeland, Nina; Hanevik, Kurt

2017-08-01

Giardia is a prevalent intestinal parasitic infection. The trophozoite structural protein a1-giardin (a1-g) and the cyst protein cyst wall protein 2 (CWP2) have shown promise as Giardia vaccine antigen candidates in murine models. The present study assesses the genetic diversity of a1-g and CWP2 between and within assemblages A and B in human clinical isolates. a1-g and CWP2 sequences were acquired from 15 Norwegian isolates by PCR amplification and 20 sequences from German cultured isolates by whole genome sequencing. Sequences were aligned to reference genomes from assemblage A2 and B to identify genetic variance. Genetic diversity was found between assemblage A and B reference sequences for both a1-g (90.8% nucleotide identity) and CWP2 (82.5% nucleotide identity). However, for a1-g, this translated into only 3 amino acid (aa) substitutions, while for CWP2 there were 41 aa substitutions, and also one aa deletion. Genetic diversity within assemblage B was larger; nucleotide identity 92.0% for a1-g and 94.3% for CWP2, than within assemblage A (nucleotide identity 99.0% for a1-g and 99.7% for CWP2). For CWP2, the diversity on both nucleotide and protein level was higher in the C-terminal end. Predicted antigenic epitopes were not affected for a1-g, but partially for CWP2. Despite genetic diversity in a1-g, we found aa sequence, characteristics, and antigenicity to be well preserved. CWP2 showed more aa variance and potential antigenic differences. Several CWP2 antigens might be necessary in a future Giardia vaccine to provide cross protection against both Giardia assemblages infecting humans.

Impact of porcine circovirus type 2 (PCV2) vaccination on boar semen quality and quantity using two different vaccines.

PubMed

Caspari, K; Henning, H; Schreiber, F; Maass, P; Gössl, R; Schaller, C; Waberski, D

2014-09-01

Porcine circovirus type-2 (PCV2) is widespread in domestic pig populations. It can be shed with boar semen, but the role boars have in epidemiology is still unclear. Vaccinating boars against PCV2 can reduce disease and virus load in semen, but may have unwanted side effects, that is, impairment of spermatogenesis. Therefore, the aim of this study was to investigate the effect and impact of two different PCV2 vaccines on boar semen quality and quantity. Healthy normospermic Large White boars in three groups of 12 each were vaccinated with either Circovac, Ingelvac CircoFLEX, or received NaCl. Eight ejaculates were collected starting 1 week after vaccination and assessed for quantitative traits. In general, sperm quantity and quality parameters did not change due to the vaccination (P > 0.05). Only DNA integrity between the Circovac and control group was P < 0.05 but remained at a low level (<2%). One boar showed clinical signs with body temperature up to 39.9 °C and went off feed. For this animal, a clear relation between vaccination, fever period, and impaired sperm quality could be observed. The results indicate that both vaccines did not have a major impact on sperm quality or quantity. Therefore, vaccination of boars against PCV2 seems to be feasible. However, one boar treated with the oil-based vaccine showed a temporarily impaired semen quality after elevated body temperature after vaccination. Thus, possible systemic reactions and the subsequent impact on sperm quality should be taken into account when choosing a PCV2 vaccine for boars. Copyright © 2014 Elsevier Inc. All rights reserved.

A recombinant pseudorabies virus co-expressing capsid proteins precursor P1-2A of FMDV and VP2 protein of porcine parvovirus: a trivalent vaccine candidate.

PubMed

Hong, Qi; Qian, Ping; Li, Xiang-Min; Yu, Xiao-Lan; Chen, Huan-Chun

2007-11-01

Pseudorabies (PR), foot-and-mouth disease (FMD), and porcine parvovirus disease are three important infectious diseases in swine worldwide. The gene-deleted pseudorabies virus (PRV) has been used as a live-viral vector to develop multivalent genetic engineering vaccine. In this study, a recombinant PRV, which could co-express protein precursor P1-2A of FMDV and VP2 protein of PPV, was constructed using PRV TK(-)/gE(-)/LacZ(+) mutant as the vector. After homologous recombination and plaque purification, recombinant virus PRV TK(-)/gE(-)/P1-2A-VP2 was acquired and identified. Immunogenicity, safety of the recombinant PRV and its protection against PRV were confirmed in a mouse model by indirect ELISA and serum neutralization test. The results show that the recombinant PRV is a candidate vaccine strain to develop a novel trivalent vaccine against PRV, FMDV and PPV in swine.

Hookworm vaccines.

PubMed

Diemert, David J; Bethony, Jeffrey M; Hotez, Peter J

2008-01-15

Hookworm infection caused by the soil-transmitted nematodes Necator americanus and Ancylostoma duodenale is one of the most common parasitic infections worldwide. Although not directly responsible for substantial mortality, it causes significant morbidity in the form of chronic anemia and protein malnutrition. Current global control efforts based on periodic mass anthelmintic administration are unsustainable, and new control strategies must be developed. This review describes progress in the development of vaccines against hookworm infection, including the preclinical and initial clinical testing of the N. americanus Ancylostoma Secreted Protein-2 Hookworm Vaccine. Plans call for eventual development of a vaccine that will combine at least 2 hookworm antigens--one targeting the larval stage of the life cycle and another targeting the adult worm living in the gastrointestinal tract.

Plant-expressed Fc-fusion protein tetravalent dengue vaccine with inherent adjuvant properties.

PubMed

Kim, Mi Young; Copland, Alastair; Nayak, Kaustuv; Chandele, Anmol; Ahmed, Muhammad S; Zhang, Qibo; Diogo, Gil R; Paul, Matthew J; Hofmann, Sven; Yang, Moon-Sik; Jang, Yong-Suk; Ma, Julian K-C; Reljic, Rajko

2017-12-09

Dengue is a major global disease requiring improved treatment and prevention strategies. The recently licensed Sanofi Pasteur Dengvaxia vaccine does not protect children under the age of nine, and additional vaccine strategies are thus needed to halt this expanding global epidemic. Here, we employed a molecular engineering approach and plant expression to produce a humanized and highly immunogenic poly-immunoglobulin G scaffold (PIGS) fused to the consensus dengue envelope protein III domain (cEDIII). The immunogenicity of this IgG Fc receptor-targeted vaccine candidate was demonstrated in transgenic mice expressing human FcγRI/CD64, by induction of neutralizing antibodies and evidence of cell-mediated immunity. Furthermore, these molecules were able to prime immune cells from human adenoid/tonsillar tissue ex vivo as evidenced by antigen-specific CD4 + and CD8 + T-cell proliferation, IFN-γ and antibody production. The purified polymeric fraction of dengue PIGS (D-PIGS) induced stronger immune activation than the monomeric form, suggesting a more efficient interaction with the low-affinity Fcγ receptors on antigen-presenting cells. These results show that the plant-expressed D-PIGS have the potential for translation towards a safe and easily scalable single antigen-based tetravalent dengue vaccine. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Swine influenza virus vaccines: to change or not to change-that's the question.

PubMed

Van Reeth, Kristien; Ma, Wenjun

2013-01-01

Commercial vaccines currently available against swine influenza virus (SIV) are inactivated, adjuvanted, whole virus vaccines, based on H1N1 and/or H3N2 and/or H1N2 SIVs. In keeping with the antigenic and genetic differences between SIVs circulating in Europe and the US, the vaccines for each region are produced locally and contain different strains. Even within a continent, there is no standardization of vaccine strains, and the antigen mass and adjuvants can also differ between different commercial products. Recombinant protein vaccines against SIV, vector, and DNA vaccines, and vaccines attenuated by reverse genetics have been tested in experimental studies, but they have not yet reached the market. In this review, we aim to present a critical analysis of the performance of commercial inactivated and novel generation SIV vaccines in experimental vaccination challenge studies in pigs. We pay special attention to the differences between commercial SIV vaccines and vaccination attitudes in Europe and in North America, to the issue of vaccine strain selection and changes, and to the potential advantages of novel generation vaccines over the traditional killed SIV vaccines.

Blood-stage malaria vaccines: post-genome strategies for the identification of novel vaccine candidates.

PubMed

Ntege, Edward H; Takashima, Eizo; Morita, Masayuki; Nagaoka, Hikaru; Ishino, Tomoko; Tsuboi, Takafumi

2017-08-01

An efficacious malaria vaccine is necessary to advance the current control measures towards malaria elimination. To-date, only RTS,S/AS01, a leading pre-erythrocytic stage vaccine completed phase 3 trials, but with an efficacy of 28-36% in children, and 18-26% in infants, that waned over time. Blood-stage malaria vaccines protect against disease, and are considered effective targets for the logical design of next generation vaccines to improve the RTS,S field efficacy. Therefore, novel blood-stage vaccine candidate discovery efforts are critical, albeit with several challenges including, high polymorphisms in vaccine antigens, poor understanding of targets of naturally protective immunity, and difficulties in the expression of high AT-rich plasmodial proteins. Areas covered: PubMed ( www.ncbi.nlm.nih.gov/pubmed ) was searched to review the progress and future prospects of malaria vaccine research and development. We focused on post-genome vaccine candidate discovery, malaria vaccine development, sequence diversity, pre-clinical and clinical trials. Expert commentary: Post-genome high-throughput technologies using wheat germ cell-free protein synthesis technology and immuno-profiling with sera from malaria patients with clearly defined outcomes are highlighted to overcome current challenges of malaria vaccine candidate discovery.

Dissection of Antibody Specificities Induced by Yellow Fever Vaccination

PubMed Central

Vratskikh, Oksana; Stiasny, Karin; Zlatkovic, Jürgen; Tsouchnikas, Georgios; Jarmer, Johanna; Karrer, Urs; Roggendorf, Michael; Roggendorf, Hedwig; Allwinn, Regina; Heinz, Franz X.

2013-01-01

The live attenuated yellow fever (YF) vaccine has an excellent record of efficacy and one dose provides long-lasting immunity, which in many cases may last a lifetime. Vaccination stimulates strong innate and adaptive immune responses, and neutralizing antibodies are considered to be the major effectors that correlate with protection from disease. Similar to other flaviviruses, such antibodies are primarily induced by the viral envelope protein E, which consists of three distinct domains (DI, II, and III) and is presented at the surface of mature flavivirions in an icosahedral arrangement. In general, the dominance and individual variation of antibodies to different domains of viral surface proteins and their impact on neutralizing activity are aspects of humoral immunity that are not well understood. To gain insight into these phenomena, we established a platform of immunoassays using recombinant proteins and protein domains that allowed us to dissect and quantify fine specificities of the polyclonal antibody response after YF vaccination in a panel of 51 vaccinees as well as determine their contribution to virus neutralization by serum depletion analyses. Our data revealed a high degree of individual variation in antibody specificities present in post-vaccination sera and differences in the contribution of different antibody subsets to virus neutralization. Irrespective of individual variation, a substantial proportion of neutralizing activity appeared to be due to antibodies directed to complex quaternary epitopes displayed on the virion surface only but not on monomeric E. On the other hand, DIII-specific antibodies (presumed to have the highest neutralizing activity) as well as broadly flavivirus cross-reactive antibodies were absent or present at very low titers. These data provide new information on the fine specificity as well as variability of antibody responses after YF vaccination that are consistent with a strong influence of individual-specific factors

Dissection of antibody specificities induced by yellow fever vaccination.

PubMed

Vratskikh, Oksana; Stiasny, Karin; Zlatkovic, Jürgen; Tsouchnikas, Georgios; Jarmer, Johanna; Karrer, Urs; Roggendorf, Michael; Roggendorf, Hedwig; Allwinn, Regina; Heinz, Franz X

2013-01-01

The live attenuated yellow fever (YF) vaccine has an excellent record of efficacy and one dose provides long-lasting immunity, which in many cases may last a lifetime. Vaccination stimulates strong innate and adaptive immune responses, and neutralizing antibodies are considered to be the major effectors that correlate with protection from disease. Similar to other flaviviruses, such antibodies are primarily induced by the viral envelope protein E, which consists of three distinct domains (DI, II, and III) and is presented at the surface of mature flavivirions in an icosahedral arrangement. In general, the dominance and individual variation of antibodies to different domains of viral surface proteins and their impact on neutralizing activity are aspects of humoral immunity that are not well understood. To gain insight into these phenomena, we established a platform of immunoassays using recombinant proteins and protein domains that allowed us to dissect and quantify fine specificities of the polyclonal antibody response after YF vaccination in a panel of 51 vaccinees as well as determine their contribution to virus neutralization by serum depletion analyses. Our data revealed a high degree of individual variation in antibody specificities present in post-vaccination sera and differences in the contribution of different antibody subsets to virus neutralization. Irrespective of individual variation, a substantial proportion of neutralizing activity appeared to be due to antibodies directed to complex quaternary epitopes displayed on the virion surface only but not on monomeric E. On the other hand, DIII-specific antibodies (presumed to have the highest neutralizing activity) as well as broadly flavivirus cross-reactive antibodies were absent or present at very low titers. These data provide new information on the fine specificity as well as variability of antibody responses after YF vaccination that are consistent with a strong influence of individual-specific factors

A glycosylated recombinant subunit candidate vaccine consisting of Ehrlichia ruminantium major antigenic protein1 induces specific humoral and Th1 type cell responses in sheep.

PubMed

Faburay, Bonto; McGill, Jodi; Jongejan, Frans

2017-01-01

Heartwater, or cowdriosis, is a tick-borne disease of domestic and wild ruminants that is endemic in the Caribbean and sub-Saharan Africa. The disease is caused by an intracellular pathogen, Ehrlichia ruminantium and may be fatal within days of the onset of clinical signs with mortality rates of up to 90% in susceptible hosts. Due to the presence of competent tick vectors in North America, there is substantial risk of introduction of heartwater with potentially devastating consequences to the domestic livestock industry. There is currently no reliable or safe vaccine for use globally. To develop a protective DIVA (differentiate infected from vaccinated animals) subunit vaccine for heartwater, we targeted the E. ruminantium immunodominant major antigenic protein1 (MAP1) with the hypothesis that MAP1 is a glycosylated protein and glycans contained in the antigenic protein are important epitope determinants. Using a eukaryotic recombinant baculovirus expression system, we expressed and characterized, for the first time, a glycoform profile of MAP1 of two Caribbean E. ruminantium isolates, Antigua and Gardel. We have shown that the 37-38 kDa protein corresponded to a glycosylated form of the MAP1 protein, whereas the 31-32 kDa molecular weight band represented the non-glycosylated form of the protein frequently reported in scientific literature. Three groups of sheep (n = 3-6) were vaccinated with increasing doses of a bivalent (Antigua and Gardel MAP1) rMAP1 vaccine cocktail formulation with montanide ISA25 as an adjuvant. The glycosylated recombinant subunit vaccine induced E. ruminantium-specific humoral and Th1 type T cell responses, which are critical for controlling intracellular pathogens, including E. ruminantium, in infected hosts. These results provide an important basis for development of a subunit vaccine as a novel strategy to protect susceptible livestock against heartwater in non-endemic and endemic areas.

A glycosylated recombinant subunit candidate vaccine consisting of Ehrlichia ruminantium major antigenic protein1 induces specific humoral and Th1 type cell responses in sheep

PubMed Central

McGill, Jodi; Jongejan, Frans

2017-01-01

Heartwater, or cowdriosis, is a tick-borne disease of domestic and wild ruminants that is endemic in the Caribbean and sub-Saharan Africa. The disease is caused by an intracellular pathogen, Ehrlichia ruminantium and may be fatal within days of the onset of clinical signs with mortality rates of up to 90% in susceptible hosts. Due to the presence of competent tick vectors in North America, there is substantial risk of introduction of heartwater with potentially devastating consequences to the domestic livestock industry. There is currently no reliable or safe vaccine for use globally. To develop a protective DIVA (differentiate infected from vaccinated animals) subunit vaccine for heartwater, we targeted the E. ruminantium immunodominant major antigenic protein1 (MAP1) with the hypothesis that MAP1 is a glycosylated protein and glycans contained in the antigenic protein are important epitope determinants. Using a eukaryotic recombinant baculovirus expression system, we expressed and characterized, for the first time, a glycoform profile of MAP1 of two Caribbean E. ruminantium isolates, Antigua and Gardel. We have shown that the 37–38 kDa protein corresponded to a glycosylated form of the MAP1 protein, whereas the 31–32 kDa molecular weight band represented the non-glycosylated form of the protein frequently reported in scientific literature. Three groups of sheep (n = 3–6) were vaccinated with increasing doses of a bivalent (Antigua and Gardel MAP1) rMAP1 vaccine cocktail formulation with montanide ISA25 as an adjuvant. The glycosylated recombinant subunit vaccine induced E. ruminantium-specific humoral and Th1 type T cell responses, which are critical for controlling intracellular pathogens, including E. ruminantium, in infected hosts. These results provide an important basis for development of a subunit vaccine as a novel strategy to protect susceptible livestock against heartwater in non-endemic and endemic areas. PMID:28957443

Design of therapeutic vaccines as a novel antibody therapy for cardiovascular diseases.

PubMed

Nakagami, Hironori

2017-09-01

Vaccines are primarily used worldwide as a preventive medicine for infectious diseases and have recently been applied to cancer. We and others have developed therapeutic vaccines designed for cardiovascular diseases that are notably different from previous vaccines. In the case of cancer vaccines, a specific protein in cancer cells is a target antigen, and the activation of cytotoxic T cells (CTL) is required to kill and remove the antigen-presenting cancer cells. Our therapeutic vaccines work against hypertension by targeting angiotensin II (Ang II) as the antigen, which is an endogenous hormone. Therapeutic vaccines must avoid CTL activation and induce the blocking antibodies for Ang II. The goal of our therapeutic vaccine for cardiovascular diseases is to induce the specific antibody response toward the target protein without inducing T-cell or antibody-mediated inflammation through the careful selection of the target antigen, carrier protein and adjuvants. The goal of our therapeutic vaccine is similar to that of antibody therapy. Recently, multiple antibody-based drugs have been developed for cancer, immune-related diseases, and dyslipidemia, which are efficient but expensive. If the effect of a therapeutic vaccine is nearly equivalent to antibody therapy as an alternative approach, the lower medical cost and improvement in drug adherence can be advantages of therapeutic vaccines. In this review, we will describe our concept of therapeutic vaccines for cardiovascular diseases and the future directions of therapeutic vaccines as novel antibody therapies. Copyright © 2017. Published by Elsevier Ltd.

Oral vaccination with different antigens from Yersinia pestis KIM delivered by live attenuated Salmonella typhimurium elicits a protective immune response against plague.

PubMed

Branger, Christine G; Fetherston, Jacqueline D; Perry, Robert D; Curtiss, Roy

2007-01-01

The use of live recombinant Salmonella attenuated vaccine (RASV) encoding Yersinia proteins is a promising new approach for the vaccination against Yersinia pestis. We have tested the efficacy of 2 proteins, Psn and a portion of LcrV in protecting mice against virulent Yersinia pestis challenge. To remove the immunosuppressive properties of LcrV protein, the lcrV gene, without the TLR2 receptor sequence, was cloned into a beta-lactamase secretion vector. Immunizations were performed with RSAV expressing LcrV or Psn. Challenge with a virulent Y. pestis strain was performed 4 weeks after the last immunization. Our results show that the truncated LcrV protein delivered by RASV is sufficient to afford a full protective immune response in a mouse model of bubonic plague and the Psn protein afforded partial protection in a non-optimized system. This finding should facilitate the design and development of a new generation of vaccines against Y. pestis.

Profiling of humoral response to influenza A(H1N1)pdm09 infection and vaccination measured by a protein microarray in persons with and without history of seasonal vaccination.

PubMed

Huijskens, Elisabeth G W; Reimerink, Johan; Mulder, Paul G H; van Beek, Janko; Meijer, Adam; de Bruin, Erwin; Friesema, Ingrid; de Jong, Menno D; Rimmelzwaan, Guus F; Peeters, Marcel F; Rossen, John W A; Koopmans, Marion

2013-01-01

The influence of prior seasonal influenza vaccination on the antibody response produced by natural infection or vaccination is not well understood. We compared the profiles of antibody responses of 32 naturally infected subjects and 98 subjects vaccinated with a 2009 influenza A(H1N1) monovalent MF59-adjuvanted vaccine (Focetria, Novartis), with and without a history of seasonal influenza vaccination. Antibodies were measured by hemagglutination inhibition (HI) assay for influenza A(H1N1)pdm09 and by protein microarray (PA) using the HA1 subunit for seven recent and historic H1, H2 and H3 influenza viruses, and three avian influenza viruses. Serum samples for the infection group were taken at the moment of collection of the diagnostic sample, 10 days and 30 days after onset of influenza symptoms. For the vaccination group, samples were drawn at baseline, 3 weeks after the first vaccination and 5 weeks after the second vaccination. We showed that subjects with a history of seasonal vaccination generally exhibited higher baseline titers for the various HA1 antigens than subjects without a seasonal vaccination history. Infection and pandemic influenza vaccination responses in persons with a history of seasonal vaccination were skewed towards historic antigens. Seasonal vaccination is of significant influence on the antibody response to subsequent infection and vaccination, and further research is needed to understand the effect of annual vaccination on protective immunity.

The use of a P. falciparum specific coiled-coil domain to construct a self-assembling protein nanoparticle vaccine to prevent malaria.

PubMed

Karch, Christopher P; Doll, Tais A P F; Paulillo, Sara M; Nebie, Issa; Lanar, David E; Corradin, Giampietro; Burkhard, Peter

2017-09-06

The parasitic disease malaria remains a major global public health concern and no truly effective vaccine exists. One approach to the development of a malaria vaccine is to target the asexual blood stage that results in clinical symptoms. Most attempts have failed. New antigens such as P27A and P27 have emerged as potential new vaccine candidates. Multiple studies have demonstrated that antigens are more immunogenic and are better correlated with protection when presented on particulate delivery systems. One such particulate delivery system is the self-assembling protein nanoparticle (SAPN) that relies on coiled-coil domains of proteins to form stable nanoparticles. In the past we have used de novo designed amino acid domains to drive the formation of the coiled-coil scaffolds which present the antigenic epitopes on the particle surface. Here we use naturally occurring domains found in the tex1 protein to form the coiled-coil scaffolding of the nanoparticle. Thus, by engineering P27A and a new extended form of the coiled-coil domain P27 onto the N and C terminus of the SAPN protein monomer we have developed a particulate delivery system that effectively displays both antigens on a single particle that uses malaria tex1 sequences to form the nanoparticle scaffold. These particles are immunogenic in a murine model and induce immune responses similar to the ones observed in seropositive individuals in malaria endemic regions. We demonstrate that our P27/P27A-SAPNs induce an immune response akin to the one in seropositive individuals in Burkina Faso. Since P27 is highly conserved among different Plasmodium species, these novel SAPNs may even provide cross-protection between Plasmodium falciparum and Plasmodium vivax the two major human malaria pathogens. As the SAPNs are also easy to manufacture and store they can be delivered to the population in need without complication thus providing a low cost malaria vaccine.

Evaluation of glutathione-binding protein A of Haemophilus parasuis as a vaccine candidate in a mouse model.

PubMed

Zhang, Yanhe; Li, Gang; Xie, Fang; Liu, Siguo; Wang, Chunlai

2017-01-24

The virulent strains of Haemophilus parasuis are the causative agents of Glässer's disease, which can cause systemic infection and result in polyserositis, meningitis and arthritis. The development of novel, effective vaccines would be beneficial to preventing H. parasuis infections. Here, we report a novel immunogenic protein, glutathione-binding protein A (GbpA), which can elicit a significant humoral antibody response and confer significant protection against challenge with a lethal dose of a highly virulent H. parasuis strain. The H. parasuis strain can be fully eliminated in the immunized mice. The results indicate that GbpA has the potential to be used as an effective component of a new vaccine against H. parasuis.

Modulatory effects of mycobacterial heat-shock protein 70 in DNA vaccination against lymphoma.

PubMed

Liso, Arcangelo; Benedetti, Roberta; Fagioli, Marta; Mariano, Angela; Falini, Brunangelo

2005-01-01

Pathogen-derived molecules are danger signals and are able to activate innate immunity that in turn controls and regulates generation of adaptive immune responses. Mycobacterium tuberculosis heat shock protein 70 (myc HSP70) has been shown to exert a potent adjuvant effect in vaccination against both infectious agents and solid tumors. Here we explore the use of myc HSP70, as an adjuvant, in DNA vaccination against lymphoma. We describe the effects of vaccination using myc HSP70 encoding plasmid (pHSP70) co-injected with idiotype encoding plasmid (pId), in the 38C13 murine lymphoma model. We dissect mechanisms of anti-tumor immune response and compared efficacy with that of other DNA vaccination strategies. We show that myc HSP70 plasmid prolongs survival of immunized mice challenged with a high number (2000) of tumor cells. The magnitude of the anti-tumor effect is comparable to that obtained using granulocyte-macrophage colony-stimulating factor (GM-CSF) in the same setting. Moreover, HSP-induced protection is independent from the generation of IgG1 and IgG2a antibodies. Instead, anti-idiotype antibodies of IgG2b subclass develop after vaccination with pHSP as well as with pId and Id-GM-CSF fusion plasmid (pId-GM). Co-injection of HSP70 and Id plasmids induces a specific pattern of anti-idiotype immune response able to improve survival of immunized mice.

Immunogenicity of recombinant vaccinia virus vaccines co-expressing GP3/GP5 of European PRRSV and Cap protein of PCV2 in pigs.

PubMed

Han, Jicheng; Ma, Haibin; Cao, Liang; Jing, Jie; Xiao, Pengpeng; Sun, Wenchao; Xie, Changzhan; Wen, Shubo; Li, Yiquan; Tian, Mingyao; Lu, Huijun; Jin, Ningyi

2018-02-01

Porcine reproductive and respiratory syndrome (PRRS) is almost always caused by the North American strain of PRRS virus (PRRSV) in China; the European genotype of PRRSV has emerged in China. The mixed infection of PRRSV and Porcine circovirus type 2 virus (PCV2) are always found in pigs and PRRSV-augmented PCV2 replication and serious clinical symptoms. Current vaccines cannot protect mixed European PRRSV and PCV2 infections. Therefore, the development of a safe and effective new vaccine to prevent and control the mixed infection of European PRRSV and PCV2 is both urgent and necessary. In this study, we developed a recombinant vaccinia vaccine co-expressing the GP3 and GP5 proteins of European PRRSV and the ORF2 protein of PCV2 and evaluated the immunogenicity and its protective effects and its inactivated vaccine in pigs. The recombinant vaccinia vaccine and its inactivated vaccine both elicited significant humoral and cellular immune responses with a higher level of specific antibody responses and T-lymphocyte proliferation than the control group. Furthermore, the pigs inoculated with the recombinant vaccinia vaccine were completely protected against challenge with 10 5 TCID 50 of European PRRSV strain LV. These data suggest that the recombinant vaccinia vaccine is a potential candidate vaccine against European PRRSV and PCV2.

HIV-1 Tat-based vaccines: from basic science to clinical trials.

PubMed

Fanales-Belasio, Emanuele; Cafaro, Aurelio; Cara, Andrea; Negri, Donatella R M; Fiorelli, Valeria; Butto, Stefano; Moretti, Sonia; Maggiorella, Maria Teresa; Baroncelli, Silvia; Michelini, Zuleika; Tripiciano, Antonella; Sernicola, Leonardo; Scoglio, Arianna; Borsetti, Alessandra; Ridolfi, Barbara; Bona, Roberta; Ten Haaft, Peter; Macchia, Iole; Leone, Pasqualina; Pavone-Cossut, Maria Rosaria; Nappi, Filomena; Vardas, Eftyhia; Magnani, Mauro; Laguardia, Elena; Caputo, Antonella; Titti, Fausto; Ensoli, Barbara

2002-09-01

Vaccination against human immunodeficiency virus (HIV)-1 infection requires candidate antigen(s) (Ag) capable of inducing an effective, broad, and long-lasting immune response against HIV-1 despite mutation events leading to differences in virus clades. The HIV-1 Tat protein is more conserved than envelope proteins, is essential in the virus life cycle and is expressed very early upon virus entry. In addition, both humoral and cellular responses to Tat have been reported to correlate with a delayed progression to disease in both humans and monkeys. This suggested that Tat is an optimal target for vaccine development aimed at controlling virus replication and blocking disease onset. Here are reviewed the results of our studies including the effects of the Tat protein on monocyte-derived dendritic cells (MDDCs) that are key antigen-presenting cells (APCs), and the results from vaccination trials with both the Tat protein or tat DNA in monkeys. We provide evidence that the HIV-1 Tat protein is very efficiently taken up by MDDCs and promotes T helper (Th)-1 type immune responses against itself as well as other Ag. In addition, a Tat-based vaccine elicits an immune response capable of controlling primary infection of monkeys with the pathogenic SHIV89.6P at its early stages allowing the containment of virus spread. Based on these results and on data of Tat conservation and immune cross-recognition in field isolates from different clades, phase I clinical trials are being initiated in Italy for both preventive and therapeutic vaccination.

Human Enterovirus 71 Protein Displayed on the Surface of Saccharomyces cerevisiae as an Oral Vaccine.

PubMed

Zhang, Congdang; Wang, Yi; Ma, Shuzhi; Li, Leike; Chen, Liyun; Yan, Huimin; Peng, Tao

2016-06-01

Human enterovirus 71 (EV-A71), a major agent of hand, foot, and mouth disease, has become an important public health issue in recent years. No effective antiviral or vaccines against EV-A71 infection are currently available. EV-A71 infection intrudes bodies through the gastric mucosal surface and it is necessary to enhance mucosal immune response to protect children from these pathogens. Recently, the majority of EV-A71 vaccine candidates have been developed for parenteral immunization. However, parenteral vaccine candidates often induce poor mucosal responses. On the other hand, oral vaccines could induce effective mucosal and systemic immunity, and could be easily and safely administered. Thus, proper oral vaccines have attached more interest compared with parenteral vaccine. In this study, the major immunogenic capsid protein of EV-A71 was displayed on the surface of Saccharomyces cerevisiae. Oral immunization of mice with surface-displayed VP1 S. cerevisiae induced systemic humoral and mucosal immune responses, including virus-neutralizing titers, VP1-specific antibody, and the induction of Th1 immune responses in the spleen. Furthermore, oral immunization of mother mice with surface-displayed VP1 S. cerevisiae conferred protection to neonatal mice against the lethal EV-A71 infection. Furthermore, we observed that multiple boost immunization as well as higher immunization dosage could induce higher EV-A71-specific immune response. Our results demonstrated that surface-displayed VP1 S. cerevisiae could be used as potential oral vaccine against EV-A71 infection.

Immune responses and protective efficacy of the gene vaccine expressing Ag85B and ESAT6 fusion protein from Mycobacterium tuberculosis.

PubMed

Chang-hong, Shi; Xiao-wu, Wang; Hai, Zhang; Ting-fen, Zhang; Li-Mei, Wang; Zhi-kai, Xu

2008-04-01

Genetic immunity is a new promising approach for the development of novel tuberculosis vaccines. In this study, it is shown that DNA vaccines expressing the fusion protein of antigen 85B (Ag85B) and early secreted antigenic target 6-kDa antigen (ESAT6) can induce high levels of specific IgG2a antibody subtype in the mice. With the prolongation of postimmunization time, the levels of IgG2a antibody decrease gradually. Although a high-level specific IgG2a antibody subtype is also elicited by classical BCG, the ratio of antibody subtypes IgG2a to IgG1 changes 4 weeks after immunization, and IgG1 is gradually shifted to the main antibody subtype. DNA vaccines also elicit cellular immunity as shown by specific spleen lymphocytes proliferation to Ag85B or ESAT6 protein and the production of high levels of IFN-gamma and IL-2, which is similar to that elicited by BCG. Vaccination of mice with DNA vaccines expressing the fusion protein Ag85B-ESAT6 results in a significant level of protection against the subsequent high-dose challenge with virulent Mycobacterium tuberculosis (MTB) H37Rv. Dramatic reduction in the number of MTB colony-forming units in the spleens and lungs is observed. Pathological examination showed that recombinant plasmid and BCG groups have only minor damage and organizational structures that are kept relatively complete, while in the control group, spleens and lungs are damaged seriously. Therefore, although the reducing degree of mycobacterial loads in the organ of mice immunized with recombinant plasmid is not more than that of BCG, through the analysis of pathological changes, we may conclude that the protective effect provided by DNA vaccine expressing the Ag85B-ESAT6 fusion protein is equivalent to that afforded by the classical BCG.

Adverse effect versus quality control of the Fuenzalida-Palacios antirabies vaccine.

PubMed

Nogueira, Y L

1998-01-01

We evaluated the components of the Fuenzalida-Palacios antirabies vaccine, which is till used in most developing countries in human immunization for treatment and prophylaxis. This vaccine is prepared from newborn mouse brains at 1% concentration. Even though the vaccine is considered to have a low myelin content, it is not fully free of myelin or of other undesirable components that might trigger adverse effects after vaccination. The most severe effect is a post-vaccination neuroparalytic accident associated with Guillain-Barré syndrome. In the present study we demonstrate how the vaccines produced and distributed by different laboratories show different component patterns with different degrees of impurity and with varying protein concentrations, indicating that production processes can vary from one laboratory to another. These differences, which could be resolved using a better quality control process, may affect and impair immunization, with consequent risks and adverse effects after vaccination. We used crossed immunoelectrophoresis to evaluate and demonstrate the possibility of quality control in vaccine production, reducing the risk factors possibly involved in these immunizing products.