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Sample records for enhanced dna vaccination

  1. Intralymphatic immunization enhances DNA vaccination

    NASA Astrophysics Data System (ADS)

    Maloy, Kevin J.; Erdmann, Iris; Basch, Veronique; Sierro, Sophie; Kramps, Thomas A.; Zinkernagel, Rolf M.; Oehen, Stefan; Kündig, Thomas M.

    2001-03-01

    Although DNA vaccines have been shown to elicit potent immune responses in animal models, initial clinical trials in humans have been disappointing, highlighting a need to optimize their immunogenicity. Naked DNA vaccines are usually administered either i.m. or intradermally. The current study shows that immunization with naked DNA by direct injection into a peripheral lymph node enhances immunogenicity by 100- to 1,000-fold, inducing strong and biologically relevant CD8+ cytotoxic T lymphocyte responses. Because injection directly into a lymph node is a rapid and easy procedure in humans, these results have important clinical implications for DNA vaccination.

  2. Polymer multilayer tattooing for enhanced DNA vaccination

    NASA Astrophysics Data System (ADS)

    Demuth, Peter C.; Min, Younjin; Huang, Bonnie; Kramer, Joshua A.; Miller, Andrew D.; Barouch, Dan H.; Hammond, Paula T.; Irvine, Darrell J.

    2013-04-01

    DNA vaccines have many potential benefits but have failed to generate robust immune responses in humans. Recently, methods such as in vivo electroporation have demonstrated improved performance, but an optimal strategy for safe, reproducible, and pain-free DNA vaccination remains elusive. Here we report an approach for rapid implantation of vaccine-loaded polymer films carrying DNA, immune-stimulatory RNA, and biodegradable polycations into the immune-cell-rich epidermis, using microneedles coated with releasable polyelectrolyte multilayers. Films transferred into the skin following brief microneedle application promoted local transfection and controlled the persistence of DNA and adjuvants in the skin from days to weeks, with kinetics determined by the film composition. These ‘multilayer tattoo’ DNA vaccines induced immune responses against a model HIV antigen comparable to electroporation in mice, enhanced memory T-cell generation, and elicited 140-fold higher gene expression in non-human primate skin than intradermal DNA injection, indicating the potential of this strategy for enhancing DNA vaccination.

  3. Enhancement of DNA vaccine potency through coadministration of CIITA DNA with DNA vaccines via gene gun.

    PubMed

    Kim, Daejin; Hoory, Talia; Monie, Archana; Ting, Jenny Pan-Yun; Hung, Chien-Fu; Wu, T-C

    2008-05-15

    Administration of DNA vaccines via gene gun has emerged as an important form of Ag-specific immunotherapy. The MHC CIITA is a master regulator of MHC class II expression and also induces expression of class I molecules. We reasoned that the gene gun administration of CIITA DNA with DNA vaccines employing different strategies to improve MHC I and II processing could enhance DNA vaccine potency. We observed that DC-1 cells transfected with CIITA DNA lead to higher expression of MHC I and II molecules, leading to enhanced Ag presentation through the MHC I/II pathways. Furthermore, our data suggested that coadministration of DNA-encoding calreticulin (CRT) linked to human papillomavirus (HPV) 16 E6 Ag (CRT/E6) with CIITA DNA leads to enhanced E6-specific CD8(+) T cell immune responses in vaccinated mice. In addition, coadministration of the combination of CRT/E6 DNA with CIITA DNA and DNA encoding the invariant chain (Ii) linked to the pan HLA-DR-reactive epitope (Ii-PADRE) further enhanced E6-specific CD8(+) T cell immune responses in vaccinated mice. Treatment with the combination vaccine was also shown to enhance the antitumor effects and to prolong survival in TC-1 tumor-bearing mice. Vaccination with the combination vaccine also led to enhanced E6-specific CD8(+) memory T cells and to long-term protection against TC-1 tumors and prolonged survival in vaccinated mice. Thus, our findings suggest that the combination of CIITA DNA with CRT/E6 and Ii-PADRE DNA vaccines represents a potentially effective means to combat tumors in the clinical setting. PMID:18453624

  4. DNA vaccination in skin enhanced by electroporation.

    PubMed

    Broderick, Kate E; Khan, Amir S; Sardesai, Niranjan Y

    2014-01-01

    DNA vaccines are a next generation branch of vaccines which offer major benefits over their conventional counterparts. However, to be effective in large mammals and humans, an enhancing delivery technology is required. Electroporation is a physical technique which results in improved delivery of large molecules through the cell membrane. In the case of plasmid DNA, electroporation enhances both the uptake and expression of the delivered DNA. The skin is an attractive tissue for DNA vaccination in a clinical setting due to the accessibility of the target, the ease of monitoring, and most importantly the immunocompetent nature of the dermis. Electroporation in the skin has the benefit of being minimally invasive and generally well tolerated. Previous studies have determined that optimized electroporation parameters (such as electrical field intensity, pulse length, pulse width, and plasmid formulation) majorly impact the efficiency of DNA delivery to the skin. We provide an overview of DNA vaccination in skin and muscle. In addition, we detail a protocol for the successful intradermal electroporation of plasmid DNA to guinea pig skin, an excellent dermatological animal model. The work detailed here suggests that the technique is safe and effective and could be highly applicable to a clinical setting. PMID:24715285

  5. Technologies for enhanced efficacy of DNA vaccines

    PubMed Central

    Saade, Fadi; Petrovsky, Nikolai

    2012-01-01

    Despite many years of research, human DNA vaccines have yet to fulfill their early promise. Over the past 15 years, multiple generations of DNA vaccines have been developed and tested in preclinical models for prophylactic and therapeutic applications in the areas of infectious disease and cancer, but have failed in the clinic. Thus, while DNA vaccines have achieved successful licensure for veterinary applications, their poor immunogenicity in humans when compared with traditional protein-based vaccines has hindered their progress. Many strategies have been attempted to improve DNA vaccine potency including use of more efficient promoters and codon optimization, addition of traditional or genetic adjuvants, electroporation, intradermal delivery and various prime–boost strategies. This review summarizes these advances in DNA vaccine technologies and attempts to answer the question of when DNA vaccines might eventually be licensed for human use. PMID:22309668

  6. DNA vaccines

    NASA Astrophysics Data System (ADS)

    Gregersen, Jens-Peter

    2001-12-01

    Immunization by genes encoding immunogens, rather than with the immunogen itself, has opened up new possibilities for vaccine research and development and offers chances for new applications and indications for future vaccines. The underlying mechanisms of antigen processing, immune presentation and regulation of immune responses raise high expectations for new and more effective prophylactic or therapeutic vaccines, particularly for vaccines against chronic or persistent infectious diseases and tumors. Our current knowledge and experience of DNA vaccination is summarized and critically reviewed with particular attention to basic immunological mechanisms, the construction of plasmids, screening for protective immunogens to be encoded by these plasmids, modes of application, pharmacokinetics, safety and immunotoxicological aspects. DNA vaccines have the potential to accelerate the research phase of new vaccines and to improve the chances of success, since finding new immunogens with the desired properties is at least technically less demanding than for conventional vaccines. However, on the way to innovative vaccine products, several hurdles have to be overcome. The efficacy of DNA vaccines in humans appears to be much less than indicated by early studies in mice. Open questions remain concerning the persistence and distribution of inoculated plasmid DNA in vivo, its potential to express antigens inappropriately, or the potentially deleterious ability to insert genes into the host cell's genome. Furthermore, the possibility of inducing immunotolerance or autoimmune diseases also needs to be investigated more thoroughly, in order to arrive at a well-founded consensus, which justifies the widespread application of DNA vaccines in a healthy population.

  7. Enhancing vaccines with immune stimulatory CpG DNA.

    PubMed

    Krieg, A M; Davis, H L

    2001-02-01

    Certain vertebrate immune cells have evolved receptors that detect the presence of pathogen DNA based on its content of unmethylated CpG dinucleotides in particular base contexts. This 'CpG DNA' acts as a 'danger signal', triggering protective innate and acquired immune responses. The activity of CpG DNA can be mimicked with synthetic oligodeoxynucleotides, which when added to a vaccine greatly boost the resulting immune response. PMID:11249727

  8. Enhancement of DNA vaccine efficacy by intracellular targeting strategies.

    PubMed

    Freitas, Elisabete Borges; Henriques, Ana Margarida; Fevereiro, Miguel; Prazeres, Duarte Miguel; Monteiro, Gabriel Amaro

    2014-01-01

    Immune response against an encoded antigenic protein can be elicited by including targeting sequences to DNA vaccines that promote protein sorting to processing pathways, related with antigen presentation by major histocompatibility complexes (MHC). Candidate DNA vaccines coding for neuraminidase 3 of the avian influenza virus were designed to encode different sequences that direct the protein to specific cellular compartments such as endoplasmic reticulum (i.e., adenovirus E1A), lysosomes (i.e., LAMP), and the combination of protein targeting to the endoplasmic reticulum and lysosome (i.e., E1A-LAMP). The DNA vaccine prototypes were engineered by biomolecular techniques and subsequently produced in E. coli cells. The biological activity of the vaccines was tested firstly in vitro, in Chinese hamster ovary cells, through flow cytometry and real-time polymerase chain reaction analysis. Then, an essential in vivo study was performed in chickens, in order to evaluate the efficacy of DNA prototype vaccines, by measuring the antibody production by enzyme-linked immunosorbent assay. PMID:24715281

  9. Molecularly engineered poly(ortho ester) microspheres for enhanced delivery of DNA vaccines

    NASA Astrophysics Data System (ADS)

    Wang, Chun; Ge, Qing; Ting, David; Nguyen, David; Shen, Hui-Rong; Chen, Jianzhu; Eisen, Herman N.; Heller, Jorge; Langer, Robert; Putnam, David

    2004-03-01

    Genetic vaccination using plasmid DNA presents a unique opportunity for achieving potent immune responses without the potential limitations of many conventional vaccines. Here we report the design of synthetic biodegradable polymers specifically for enhancing DNA vaccine efficacy in vivo. We molecularly engineered poly(ortho ester) microspheres that are non-toxic to cells, protect DNA from degradation, enable uptake by antigen-presenting cells, and release DNA rapidly in response to phagosomal pH. One type of microsphere of poly(ortho esters) that releases DNA vaccines in synchrony with the natural development of adaptive immunity, elicited distinct primary and secondary humoral and cellular immune responses in mice, and suppressed the growth of tumour cells bearing a model antigen. This polymer microparticulate system could, with further study, have implications for advancing the clinical utility of DNA vaccines as well as other nucleic-acid-based therapeutics against viral infections and cancer.

  10. Electroporation Enhances Immunogenicity of a DNA Vaccine Expressing Woodchuck Hepatitis Virus Surface Antigen in Woodchucks▿

    PubMed Central

    Liu, Katherine H.; Ascenzi, Mary A.; Bellezza, Christine A.; Bezuidenhout, Abraham J.; Cote, Paul J.; Gonzalez-Aseguinolaza, Gloria; Hannaman, Drew; Luxembourg, Alain; Evans, Claire F.; Tennant, Bud C.; Menne, Stephan

    2011-01-01

    The development of therapeutic vaccines for chronic hepatitis B virus (HBV) infection has been hampered by host immune tolerance and the generally low magnitude and inconsistent immune responses to conventional vaccines and proposed new delivery methods. Electroporation (EP) for plasmid DNA (pDNA) vaccine delivery has demonstrated the enhanced immunogenicity of HBV antigens in various animal models. In the present study, the efficiency of the EP-based delivery of pDNA expressing various reporter genes first was evaluated in normal woodchucks, and then the immunogenicity of an analog woodchuck hepatitis virus (WHV) surface antigen (WHsAg) pDNA vaccine was studied in this model. The expression of reporter genes was greatly increased when the cellular uptake of pDNA was facilitated by EP. The EP of WHsAg-pDNA resulted in enhanced, dose-dependent antibody and T-cell responses to WHsAg compared to those of the conventional hypodermic needle injection of WHsAg-pDNA. Although subunit WHsAg protein vaccine elicited higher antibody titers than the DNA vaccine delivered with EP, T-cell response rates were comparable. However, in WHsAg-stimulated mononuclear cell cultures, the mRNA expression of CD4 and CD8 leukocyte surface markers and Th1 cytokines was more frequent and was skewed following DNA vaccination compared to that of protein immunization. Thus, the EP-based vaccination of normal woodchucks with pDNA-WHsAg induced a skew in the Th1/Th2 balance toward Th1 immune responses, which may be considered more appropriate for approaches involving therapeutic vaccines to treat chronic HBV infection. PMID:21389124

  11. Polyplex-releasing microneedles for enhanced cutaneous delivery of DNA vaccine.

    PubMed

    Kim, Nak Won; Lee, Min Sang; Kim, Kyu Ri; Lee, Jung Eun; Lee, Kyuri; Park, Jong Sung; Matsumoto, Yoh; Jo, Dong-Gyu; Lee, Haeshin; Lee, Doo Sung; Jeong, Ji Hoon

    2014-04-10

    Microneedle (MN)-based DNA vaccines have many advantages over conventional vaccines administered by hypodermic needles. However, an efficient strategy for delivering DNA vaccines to intradermal cells has not yet been established. Here, we report a new approach for delivering polyplex-based DNA vaccines using MN arrays coated with a pH-responsive polyelectrolyte multilayer assembly (PMA). This approach enabled rapid release of polyplex upon application to the skin. In addition to the polyplex-releasing MNs, we attempted to further maximize the vaccination by developing a polymeric carrier that targeted resident antigen presenting cells (APCs) rich in the intradermal area, as well as a DNA vaccine encoding a secretable fusion protein containing amyloid beta monomer (Aβ1-42), an antigenic determinant. The resulting vaccination system was able to successfully induce a robust humoral immune response compared to conventional subcutaneous injection with hypodermal needles. In addition, antigen challenge after immunization elicited an immediate and strong recall immune response due to immunogenic memory. These results suggest the potential utility of MN-based polyplex delivery systems for enhanced DNA vaccination. PMID:24462900

  12. Poly-L-lysine-coated nanoparticles: a potent delivery system to enhance DNA vaccine efficacy.

    PubMed

    Minigo, Gabriela; Scholzen, Anja; Tang, Choon K; Hanley, Jennifer C; Kalkanidis, Martha; Pietersz, Geoffrey A; Apostolopoulos, Vasso; Plebanski, Magdalena

    2007-01-26

    DNA formulations provide the basis for safe and cost efficient vaccines. However, naked plasmid DNA is only poorly immunogenic and new effective delivery strategies are needed to enhance the potency of DNA vaccines. In this study, we present a novel approach for the delivery of DNA vaccines using inert poly-L-lysine (PLL) coated polystyrene particles, which greatly enhance DNA immunogenicity. Intradermal injection of plasmid DNA encoding for chicken egg ovalbumin (OVA) complexed with PLL-coated polystyrene nanoparticles induced high levels of CD8 T cells as well as OVA-specific antibodies in C57BL/6 mice and furthermore inhibited tumour growth after challenge with the OVA expressing EG7 tumour cell line. Importantly, vaccine efficacy depended critically on the size of the particles used as well as on the presence of the PLL linker. Our data show that PLL-coated polystyrene nanoparticles of 0.05 microm but not 0.02 microm or 1.0 microm in diameter are highly effective for the delivery of DNA vaccines. PMID:17052812

  13. Optimization of Electroporation-Enhanced Intradermal Delivery of DNA Vaccine Using a Minimally Invasive Surface Device

    PubMed Central

    Lin, Feng; Shen, Xuefei; Kichaev, Gleb; Mendoza, Janess M.; Yang, Maria; Armendi, Philip; Yan, Jian; Kobinger, Gary P.; Bello, Alexander; Khan, Amir S.; Broderick, Kate E.

    2012-01-01

    Abstract In vivo electroporation (EP) is an efficient nonviral method for enhancing DNA vaccine delivery and immunogenicity in animals and humans. Intradermal delivery of DNA vaccines is an attractive strategy because of the immunocompetence of skin tissue. We have previously reported a minimally invasive surface intradermal EP (SEP) device for delivery of prophylactic DNA vaccines. Robust antibody responses were induced after vaccine delivery via surface EP in several tested animal models. Here we further investigated the optimal EP parameters for efficient delivery of DNA vaccines, with a specific emphasis on eliciting cellular immunity in addition to robust humoral responses. In a mouse model, using applied voltages of 10–100 V, transgene expression of green fluorescent protein and luciferase reporter genes increased significantly when voltages as low as 10 V were used as compared with DNA injection only. Tissue damage to skin was undetectable when voltages of 20 V and less were applied. However, inflammation and bruising became apparent at voltages above 40 V. Delivery of DNA vaccines encoding influenza virus H5 hemagglutinin (H5HA) and nucleoprotein (NP) of influenza H1N1 at applied voltages of 10–100 V elicited robust and sustained antibody responses. In addition, low-voltage (less than 20 V) EP elicited higher and more sustained cellular immune responses when compared with the higher voltage (above 20 V) EP groups after two immunizations. The data confirm that low-voltage EP, using the SEP device, is capable of efficient delivery of DNA vaccines into the skin, and establishes that these parameters are sufficient to elicit both robust and sustainable humoral as well as cellular immune responses without tissue damage. The SEP device, functioning within these parameters, may have important clinical applications for delivery of prophylactic DNA vaccines against diseases such as HIV infection, malaria, and tuberculosis that require both cellular

  14. Optimization of electroporation-enhanced intradermal delivery of DNA vaccine using a minimally invasive surface device.

    PubMed

    Lin, Feng; Shen, Xuefei; Kichaev, Gleb; Mendoza, Janess M; Yang, Maria; Armendi, Philip; Yan, Jian; Kobinger, Gary P; Bello, Alexander; Khan, Amir S; Broderick, Kate E; Sardesai, Niranjan Y

    2012-06-01

    In vivo electroporation (EP) is an efficient nonviral method for enhancing DNA vaccine delivery and immunogenicity in animals and humans. Intradermal delivery of DNA vaccines is an attractive strategy because of the immunocompetence of skin tissue. We have previously reported a minimally invasive surface intradermal EP (SEP) device for delivery of prophylactic DNA vaccines. Robust antibody responses were induced after vaccine delivery via surface EP in several tested animal models. Here we further investigated the optimal EP parameters for efficient delivery of DNA vaccines, with a specific emphasis on eliciting cellular immunity in addition to robust humoral responses. In a mouse model, using applied voltages of 10-100 V, transgene expression of green fluorescent protein and luciferase reporter genes increased significantly when voltages as low as 10 V were used as compared with DNA injection only. Tissue damage to skin was undetectable when voltages of 20 V and less were applied. However, inflammation and bruising became apparent at voltages above 40 V. Delivery of DNA vaccines encoding influenza virus H5 hemagglutinin (H5HA) and nucleoprotein (NP) of influenza H1N1 at applied voltages of 10-100 V elicited robust and sustained antibody responses. In addition, low-voltage (less than 20 V) EP elicited higher and more sustained cellular immune responses when compared with the higher voltage (above 20 V) EP groups after two immunizations. The data confirm that low-voltage EP, using the SEP device, is capable of efficient delivery of DNA vaccines into the skin, and establishes that these parameters are sufficient to elicit both robust and sustainable humoral as well as cellular immune responses without tissue damage. The SEP device, functioning within these parameters, may have important clinical applications for delivery of prophylactic DNA vaccines against diseases such as HIV infection, malaria, and tuberculosis that require both cellular and humoral immune

  15. Targeted DNA vaccines for enhanced induction of idiotype-specific B and T cells

    PubMed Central

    Fredriksen, Agnete B.; Sandlie, Inger; Bogen, Bjarne

    2012-01-01

    Background: Idiotypes (Id) are antigenic determinants localized in variable (V) regions of Ig. Id-specific T and B cells (antibodies) play a role in immunotherapy of Id+ tumors. However, vaccine strategies that enhance Id-specific responses are needed. Methods: Id+ single-chain fragment variable (scFv) from multiple myelomas and B cell lymphomas were prepared in a fusion format that bivalently target surface molecules on antigen-presenting cells (APC). APC-specific targeting units were either scFv from APC-specific mAb (anti-MHC II, anti-CD40) or chemokines (MIP-1α, RANTES). Homodimeric Id-vaccines were injected intramuscularly or intradermally as plasmids in mice, combined with electroporation. Results: (i) Transfected cells secreted plasmid-encoded Id+ fusion proteins to extracellular fluid followed by binding of vaccine molecules to APC. (ii) Targeted vaccine molecules increased Id-specific B and T cell responses. (iii) Bivalency and xenogeneic sequences both contributed to enhanced responses. (iv) Targeted Id DNA vaccines induced tumor resistance against challenges with Id+ tumors. (v) Human MIP-1α targeting units enhanced Id-specific responses in mice, due to a cross reaction with murine chemokine receptors. Thus, targeted vaccines designed for humans can be quality tested in mice. (vi) Human Id+ scFv from four multiple myeloma patients were inserted into the vaccine format and were successfully tested in mice. (vii) Human MIP-1α vaccine proteins enhanced human T cell responses in vitro. (viii) A hypothetical model for how the APC-targeted vaccine molecules enhance Id-specific T and B cells is presented. Conclusion: Targeted DNA Id-vaccines show promising results in preclinical studies, paving the way for testing in patients. PMID:23115759

  16. C3d enhanced DNA vaccination induced humoral immune response to glycoprotein C of pseudorabies virus

    SciTech Connect

    Tong Tiezhu; Fan Huiying; Tan Yadi; Xiao Shaobo; Ling Jieyu; Chen Huanchun; Guo Aizhen . E-mail: aizhen@mail.hzau.edu.cn

    2006-09-08

    Murine C3d were utilized to enhance immunogenicity of pseudorabies virus (PrV) gC DNA vaccination. Three copies of C3d and four copies of CR2-binding domain M28{sub 4} were fused, respectively, to truncated gC gene encoding soluble glycoprotein C (sgC) in pcDNA3.1. BALB/c mice were, respectively, immunized with recombinant plasmids, blank vector, and inactivated vaccine. The antibody ELISA titer for sgC-C3d{sub 3} DNA was 49-fold more than that for sgC DNA, and the neutralizing antibody obtained 8-fold rise. Protection of mice from death after lethal PrV (316 LD{sub 5}) challenge was augmented from 25% to 100%. Furthermore, C3d fusion increased Th2-biased immune response by inducing IL-4 production. The IL-4 level for sgC-C3d{sub 3} DNA immunization approached that for the inactivated vaccine. Compared to C3d, M28 enhanced sgC DNA immunogenicity to a lesser extent. In conclusion, we demonstrated that murine C3d fusion significantly enhanced gC DNA immunity by directing Th1-biased to a balanced and more effective Th1/Th2 response.

  17. Keratinocyte growth factor enhances DNA plasmid tumor vaccine responses after murine allogeneic bone marrow transplantation

    PubMed Central

    Jenq, Robert R.; King, Christopher G.; Volk, Christine; Suh, David; Smith, Odette M.; Rao, Uttam K.; Yim, Nury L.; Holland, Amanda M.; Lu, Sydney X.; Zakrzewski, Johannes L.; Goldberg, Gabrielle L.; Diab, Adi; Alpdogan, Onder; Penack, Olaf; Na, Il-Kang; Kappel, Lucy W.; Wolchok, Jedd D.; Houghton, Alan N.; Perales, Miguel-Angel

    2009-01-01

    Keratinocyte growth factor (KGF), which is given exogenously to allogeneic bone marrow transplantation (allo-BMT) recipients, supports thymic epithelial cells and increases thymic output of naive T cells. Here, we demonstrate that this improved T-cell reconstitution leads to enhanced responses to DNA plasmid tumor vaccination. Tumor-bearing mice treated with KGF and DNA vaccination have improved long-term survival and decreased tumor burden after allo-BMT. When assayed before vaccination, KGF-treated allo-BMT recipients have increased numbers of peripheral T cells, including CD8+ T cells with vaccine-recognition potential. In response to vaccination, KGF-treated allo-BMT recipients, compared with control subjects, generate increased numbers of tumor-specific CD8+ cells, as well as increased numbers of CD8+ cells producing interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α). We also found unanticipated benefits to antitumor immunity with the administration of KGF. KGF-treated allo-BMT recipients have an improved ratio of T effector cells to regulatory T cells, a larger fraction of effector cells that display a central memory phenotype, and effector cells that are derived from a broader T-cell–receptor repertoire. In conclusion, our data suggest that KGF can function as a potent vaccine adjuvant after allo-BMT through its effects on posttransplantation T-cell reconstitution. PMID:19011222

  18. Enhancement of Poly(orthoester) Microspheres for DNA Vaccine Delivery by Blending with Poly(ethylenimine)

    PubMed Central

    Nguyen, David N.; Raghavan, Shyam S.; Tashima, Lauren M.; Lin, Elizabeth C.; Fredette, Stephen J.; Langer, Robert S.; Wang, Chun

    2008-01-01

    Poly(ortho ester) (POE) microspheres have been previously shown to possess certain advantages for the in vivo delivery of DNA vaccines. In particular, timing of DNA release from POE microspheres in response to acidic phagosomal pH was shown to be an important factor in determining immunogenicity, which was hypothesized to be linked to the natural progression of antigen presenting cell uptake, transfection, maturation, and antigen presentation. Here we report in vitro characterization of the enhanced the efficacy of POE microspheres by blending poly(ethylenimine) (PEI), a well-characterized cationic transfection agent, into the POE matrix. Blending of a tiny amount of PEI (approximately 0.04 wt%) with POE caused large alterations in POE microsphere properties. PEI provided greater control over the rate of pH-triggered DNA release by doubling the total release time of plasmid DNA and enhanced gene transfection efficiency of the microspheres up to 50-fold without any significant cytotoxicity. Confocal microscopy with labeled PEI and DNA plasmids revealed that PEI caused a surface-localizing distribution of DNA and PEI within the POE microsphere as well as focal co-localization of PEI with DNA. We provide evidence that upon degradation, the microspheres of POE-PEI blends released electrostatic complexes of DNA and PEI, which are responsible for the enhanced gene transfection. Furthermore, blending PEI into the POE microsphere induced 50% to 60% greater phenotypic maturation and activation of bone marrow-derived dendritic cells in vitro, judged by up-regulation of co-stimulatory markers on the cell surface. Physically blending PEI with POE is a simple approach for modulating the properties of biodegradable microspheres in terms of gene transfection efficiency and DNA release kinetics. Combined with the ability to induce maturation of antigen-presenting cells, POE-PEI blended microspheres may be excellent carriers for DNA vaccines. PMID:18400294

  19. Enhanced non-inflammasome mediated immune responses by mannosylated zwitterionic-based cationic liposomes for HIV DNA vaccines.

    PubMed

    Qiao, Chenmeng; Liu, Jiandong; Yang, Jun; Li, Yan; Weng, Jie; Shao, Yiming; Zhang, Xin

    2016-04-01

    Human immunodeficiency virus (HIV) DNA vaccine can induce cellular and humoral immunity. A safe and effective HIV DNA vaccine is urgent need to prevent the spread of acquired immune deficiency syndrome (AIDS). The major drawback of DNA vaccines is the low immunogenicity, which is caused by the poor delivery to antigen presenting cells and insufficient antigen expression. Sparked by the capability of endosomal/lysosomal escape of the zwitterionic lipid distearoyl phosphoethanol-amine-polycarboxybetaine (DSPE-PCB), we attempted to develop a zwitterionic-based cationic liposome with enhanced immunogenicity of DNA vaccines. The mannosylated zwitterionic-based cationic liposome (man-ZCL) was constructed as a DNA vaccine adjuvant for HIV vaccination. Man-ZCL could complex with DNA antigens to form a tight structure and protect them from nuclei enzyme degradation. Benefited from the capability of the specific mannose receptor mediated antigen processing cells targeting and enhanced endosomal/lysosomal escape, the man-ZCL lipoplexes were supposed to promote antigen presentation and the immunogenicity of DNA vaccines. In vitro and in vivo results revealed that man-ZCL lipoplexes showed enhanced anti-HIV immune responses and lower toxicity compared with CpG/DNA and Lipo2k/DNA, and triggered a Th1/Th2 mixed immunity. An antigen-depot effect was observed in the administration site, and this resulted in enhanced retention of DNA antigens in draining lymph nodes. Most importantly, the man-ZCL could assist to activate T cells through a non-inflammasome pathway. These findings suggested that the man-ZCL could be potentially applied as a safe and efficient DNA adjuvant for HIV vaccines. PMID:26851653

  20. Low-dose radiation enhances therapeutic HPV DNA vaccination in tumor-bearing hosts.

    PubMed

    Tseng, Chih-Wen; Trimble, Cornelia; Zeng, Qi; Monie, Archana; Alvarez, Ronald D; Huh, Warner K; Hoory, Talia; Wang, Mei-Cheng; Hung, Chien-Fu; Wu, T-C

    2009-05-01

    Current therapeutic approaches to treatment of patients with bulky cervical cancer are based on conventional in situ ablative modalities including cisplatin-based chemotherapy and radiation therapy. The 5-year survival of patients with nonresectable disease is dismal. Because over 99% of squamous cervical cancer is caused by persistent infection with an oncogenic strain of human papillomavirus (HPV), particularly type 16 and viral oncoproteins E6 and E7 are functionally required for disease initiation and persistence, HPV-targeted immune strategies present a compelling opportunity in which to demonstrate proof of principle. Sublethal doses of radiation and chemotherapeutic agents have been shown to have synergistic effect in combination with either vaccination against cancer-specific antigens, or with passive transfer of tumor-specific cytotoxic T lymphocytes (CTLs). Here, we explored the combination of low-dose radiation therapy with DNA vaccination with calreticulin (CRT) linked to the mutated form of HPV-16 E7 antigen (E7(detox)), CRT/E7(detox) in the treatment of E7-expressing TC-1 tumors. We observed that TC-1 tumor-bearing mice treated with radiotherapy combined with CRT/E7(detox) DNA vaccination generated significant therapeutic antitumor effects and the highest frequency of E7-specific CD8(+) T cells in the tumors and spleens of treated mice. Furthermore, treatment with radiotherapy was shown to render the TC-1 tumor cells more susceptible to lysis by E7-specific CTLs. In addition, we observed that treatment with radiotherapy during the second DNA vaccination generated the highest frequency of E7-specific CD8(+) T cells in the tumors and spleens of TC-1 tumor-bearing mice. Finally, TC-1 tumor-bearing mice treated with the chemotherapy in combination with radiation and CRT/E7(detox) DNA vaccination generate significantly enhanced therapeutic antitumor effects. The clinical implications of the study are discussed. PMID:18815785

  1. DNA vaccine for cancer immunotherapy

    PubMed Central

    Yang, Benjamin; Jeang, Jessica; Yang, Andrew; Wu, T C; Hung, Chien-Fu

    2015-01-01

    DNA vaccination has emerged as an attractive immunotherapeutic approach against cancer due to its simplicity, stability, and safety. Results from numerous clinical trials have demonstrated that DNA vaccines are well tolerated by patients and do not trigger major adverse effects. DNA vaccines are also very cost effective and can be administered repeatedly for long-term protection. Despite all the practical advantages, DNA vaccines face challenges in inducing potent antigen specific cellular immune responses as a result of immune tolerance against endogenous self-antigens in tumors. Strategies to enhance immunogenicity of DNA vaccines against self-antigens have been investigated including encoding of xenogeneic versions of antigens, fusion of antigens to molecules that activate T cells or trigger associative recognition, priming with DNA vectors followed by boosting with viral vector, and utilization of immunomodulatory molecules. This review will focus on discussing strategies that circumvent immune tolerance and provide updates on findings from recent clinical trials. PMID:25625927

  2. Chicken IL-7 as a potent adjuvant enhances IBDV VP2 DNA vaccine immunogenicity and protective efficacy.

    PubMed

    Huo, Shanshan; Zuo, Yuzhu; Li, Nan; Li, Xiujin; Zhang, Yonghong; Wang, Liyue; Liu, Hao; Zhang, Jianlou; Cui, Dan; He, Pingyou; Xu, Jian; Li, Yan; Zhu, Xiutong; Zhong, Fei

    2016-09-25

    Our previous work has demonstrated that the mammalian interleukin-7 (IL-7) gene can enhance the immunogenicity of DNA vaccine. Whether chicken IL-7 (chIL-7) possesses the ability to enhance the immunogenicity of VP2 DNA vaccine of infectious bursal disease virus (IBDV) remained unknown. To investigate this, we constructed a VP2 antigenic region (VP2366) gene and chIL-7 gene vectors, co-immunized chicken with these vectors and analyzed the effects of the chIL-7 gene on VP2366 gene immunogenicity. Results showed that co-administrated chIL-7 gene with VP2 DNA vaccine significantly increased specific serum antibody titers against IBDV, and enhanced lymphocyte proliferation and IFN-γ and IL-4 productions. More importantly, chIL-7 gene significantly increased VP2366 gene-induced protection against virulent IBDV infection, indicating that the chIL-7 gene possessed the capacity to enhance VP2366 DNA vaccine immunogenicity, and therefore might function as a novel adjuvant for IBDV VP2 DNA vaccine. Mechanically, chIL-7 could stimulate the common cytokine receptor γ chain (γc) expressions in vitro and in vivo, which might be involved in chIL-7 enhancement of the immunogenicity of VP2 DNA vaccine. PMID:27599941

  3. The swine CD81 enhances E2-based DNA vaccination against classical swine fever.

    PubMed

    Li, Wenliang; Mao, Li; Zhou, Bin; Liu, Xia; Yang, Leilei; Zhang, Wenwen; Jiang, Jieyuan

    2015-07-01

    Classical swine fever (CSF) is a highly contagious and economically important viral disease that affects the pig industry worldwide. The glycoprotein E2 of CSFV can induce neutralizing antibodies and protective immunity, and is widely used for novel vaccine development. The objective of this study was to explore whether a tetraspanin molecule CD81 could improve the immune responses of an E2-based DNA vaccine. Plasmids pVAX-CD81, pVAX-E2 and pVAX-CD81-E2 were constructed and the expression of target proteins was confirmed in BHK-21 cells by indirect immunofluorescence assay. BALB/c mice were divided into 5 groups and immunized with different plasmids (pVAX-E2, pVAX-CD81-E2, pVAX-E2+pVAX-CD81, pVAX-CD81 and PBS) three times with two weeks interval. The results showed that the introduction of CD81 promoted higher humoral and cellular immune responses than E2 expression alone (P<0.05). In addition, immunization with pVAX-CD81-E2 induced stronger immune responses than pVAX-E2+pVAX-CD81. Furthermore, four groups of pigs were immunized with pVAX-E2, pVAX-CD81-E2, pVAX-CD81 and PBS, respectively. Humoral and cellular immune responses detection showed similar results with those in mice. Compared to pVAX-E2, pVAX-CD81-E2 induced higher titers of neutralizing antibodies after viral challenge and conferred stronger protection. These results confirmed the capacity of swine CD81 enhancing the humoral and cellular responses with an adjuvant effect on CSFV DNA vaccine. This is the first report demonstrating the adjuvant effect of CD81 to enhance the DNA vaccination for swine pathogen. PMID:26051512

  4. A novel adjuvant Ling Zhi-8 enhances the efficacy of DNA cancer vaccine by activating dendritic cells.

    PubMed

    Lin, Chi-Chen; Yu, Yen-Ling; Shih, Chia-Chiao; Liu, Ko-Jiunn; Ou, Keng-Liang; Hong, Ling-Zong; Chen, Jody D C; Chu, Ching-Liang

    2011-07-01

    DNA vaccine has been suggested to use in cancer therapy, but the efficacy remains to be improved. The immunostimulatory effect of a fungal immunomodulatory protein Ling Zhi-8 (LZ-8) isolated from Ganoderma lucidum has been reported. In this study, we tested the adjuvanticity of LZ-8 for HER-2/neu DNA vaccine against p185(neu) expressing tumor MBT-2 in mice. We found that recombinant LZ-8 stimulated mouse bone marrow-derived dendritic cells (DCs) via TLR4 and its stimulatory effect was not due to any microbe contaminant. In addition, LZ-8 enhanced the ability of DCs to induce antigen-specific T cell activation in vitro and in a subunit vaccine model in vivo. Surprisingly, LZ-8 cotreatment strongly improved the therapeutic effect of DNA vaccine against MBT-2 tumor in mice. This increase in antitumor activity was attributed to the enhancement of vaccine-induced Th1 and CTL responses. Consistent with the results from DCs, the promoting effect of LZ-8 on DNA vaccine was diminished when the MBT-2 tumor cells were grown in TLR4 mutant mice. Thus, we concluded that LZ-8 may be a promising adjuvant to enhance the efficacy of DNA vaccine by activating DCs via TLR4. PMID:21499904

  5. Soluble multi-trimeric TNF superfamily ligand adjuvants enhance immune responses to a HIV-1 Gag DNA vaccine

    PubMed Central

    Kanagavelu, Saravana K.; Snarsky, Victoria; Termini, James M.; Gupta, Sachin; Barzee, Suzanne; Wright, Jacqueline A.; Khan, Wasif N.; Kornbluth, Richard S.; Stone, Geoffrey W.

    2011-01-01

    Background DNA vaccines remain an important component of HIV vaccination strategies, typically as part of a prime/boost vaccination strategy with viral vector or protein boost. A number of DNA prime/viral vector boost vaccines are currently being evaluated for both preclinical studies and in Phase I and Phase II clinical trials. These vaccines would benefit from molecular adjuvants that increase correlates of immunity during the DNA prime. While HIV vaccine immune correlates are still not well defined, there are a number of immune assays that have been shown to correlate with protection from viral challenge including CD8+ T cell avidity, antigen-specific proliferation, and polyfunctional cytokine secretion. Methodology and Principal Findings Recombinant DNA vaccine adjuvants composed of a fusion between Surfactant Protein D (SP-D) and either CD40 Ligand (CD40L) or GITR Ligand (GITRL) were previously shown to enhance HIV-1 Gag DNA vaccines. Here we show that similar fusion constructs composed of the TNF superfamily ligands (TNFSFL) 4-1BBL, OX40L, RANKL, LIGHT, CD70, and BAFF can also enhanced immune responses to a HIV-1 Gag DNA vaccine. BALB/c mice were vaccinated intramuscularly with plasmids expressing secreted Gag and SP-D-TNFSFL fusions. Initially, mice were analyzed 2 weeks or 7 weeks following vaccination to evaluate the relative efficacy of each SP-D-TNFSFL construct. All SP-D-TNFSFL constructs enhanced at least one Gag-specific immune response compared to the parent vaccine. Importantly, the constructs SP-D-4-1BBL, SP-D-OX40L, and SP-D-LIGHT enhanced CD8+ T cell avidity and CD8+/CD4+ T cell proliferation 7 weeks post vaccination. These avidity and proliferation data suggest that 4-1BBL, OX40L, and LIGHT fusion constructs may be particularly effective as vaccine adjuvants. Constructs SP-D-OX40L, SP-D-LIGHT, and SP-D-BAFF enhanced Gag-specific IL-2 secretion in memory T cells, suggesting these adjuvants can increase the number of self-renewing Gag-specific CD8

  6. DNA prime-protein boost vaccination enhances protective immunity against infectious bursal disease virus in chickens.

    PubMed

    Gao, Honglei; Li, Kai; Gao, Li; Qi, Xiaole; Gao, Yulong; Qin, Liting; Wang, Yongqiang; Wang, Xiaomei

    2013-05-31

    Infectious bursal disease virus causes an acute contagious immunosuppressive disease in chickens. Using VP2 protein from IBDV (Gx strain) as the immunogen, the goal of the current study was to evaluate the immune responses and protective efficacy elicited by different prime-boost vaccination regimens (DNA only, protein only, and DNA plus protein) in chickens. The results indicated that both pCAGoptiVP2 plasmid and rVP2 protein induced humoral and cellular immune responses. Chickens in the DNA prime-protein boost group developed significantly higher levels of ELISA and neutralizing antibodies to IBDV compared with those immunized with either the DNA vaccine or the protein vaccine alone (P<0.05). Furthermore, the highest levels of lymphocyte proliferation response, IL-4 and IFN-γ production were induced following priming with the DNA vaccine and boosting with the rVP2 protein. Additionally, chickens inoculated with the DNA prime-protein boost vaccine had 100% protection against challenge with vvIBDV, as evidenced by the absence of clinical signs, mortality, and bursal atrophy. In contrast, chickens receiving the DNA vaccine and the rVP2 protein vaccine had 67% and 80% protection, respectively. These findings demonstrated that the DNA prime-protein boost immunization strategy was effective in eliciting both humoral and cellular immune responses in chickens, highlighting the potential value of such an approach in the prevention of vvIBDV infection. PMID:23419823

  7. CD226 as a genetic adjuvant to enhance immune efficacy induced by Ag85A DNA vaccination.

    PubMed

    Li, Yan; Yang, Fangli; Zhu, Junfeng; Sang, Lixuan; Han, Xue; Wang, Danan; Shan, Fengping; Li, Shengjun; Sun, Xun; Lu, Changlong

    2015-03-01

    Antigen-85A (Ag85A) is one of the major proteins secreted by Mycobacterium tuberculosis. Many studies on animal models have shown that vaccination with the recombinant Ag85A-DNA or Ag85A protein induces powerful immune response. However, these vaccines cannot generate sufficient protective immunity in the systemic compartment. CD226, a member of the immunoglobulin superfamily, is expressed in the majority of NK cells, T cells, monocytes, and platelets, and can be served as a co-stimulator that contributes to multiple innate and adaptive responses. However, there has been no study where either CD226 protein or DNA has been used as an adjuvant for vaccine development. The aim of this study was to develop a novel Ag85A DNA vaccine with CD226 as the genetic adjuvant to increase the immune efficacy induced by Ag85A. Oral vaccination with pcDNA3.1-Ag85A-CD226 DNA induced potent immune responses in mice. CD226 was an effective genetic adjuvant that improved the immune efficacy induced by Ag85A and enhanced the activity of cytotoxic T lymphocytes (CTL) and NK cells in mice. Th1 dominant cytokines (i.e. IL-2, IFN-γ and TNF-α), cellular immunity (i.e. CD4(+)IFN-γ(+)T cells and CD8(+)IFN-γ(+)T cells in splenocytes) and MLNs were also significantly elevated by pcDNA3.1-Ag85A-CD226 DNA vaccination. Our results suggest that CD226 is an effective adjuvant to enhance the immune efficacy induced by Ag85A. Our findings provide a new strategy for the development of a DNA vaccine co-expressing Ag85A and CD226. PMID:25582686

  8. The use of layered double hydroxides as DNA vaccine delivery vector for enhancement of anti-melanoma immune response.

    PubMed

    Li, Ang; Qin, Lili; Wang, Wenrui; Zhu, Rongrong; Yu, Yongchun; Liu, Hui; Wang, Shilong

    2011-01-01

    Our previous studies have shown that Mg:Al 1:1 layered double hydroxides (LDH(R1)) nanoparticles could be taken up by the MDDCs effectively and had an adjuvant activity for DC maturation. Furthermore, these LDH(R1) nanoparticles could up-regulate the expression of CCR7 and augment the migration of DCs in response to CCL21. In current study, we have evaluated whether LDH(R1) as DNA vaccine delivery carrier can augment the efficacy of DNA vaccine immunization in vivo. Firstly, we found that LDH(R1) was efficient in combining DNA and formed LDH(R1)/DNA complex with an average diameter of about 80-120 nm. Its high transfection efficiency in vivo delivered with a GFP expression plasmid was also observed. After delivery of pcDNA(3)-OVA/LDH(R1) complex by intradermal immunization in C57BL/6 mice, the LDH(R1) induced an enhanced serum antibody response much greater than naked DNA vaccine. Using B16-OVA melanoma as tumor model, we demonstrated that pcDNA(3)-OVA/LDH(R1) complex enhanced immune priming and protection from tumor challenge in vivo. Furthermore, we showed that LDH(R1) induced dramatically more effective CTL activation and skewed T helper polarization to Th1. Collectively, these findings demonstrate that this LDH(R1)/DNA plasmid complex should be a new and promising way in vaccination against tumor. PMID:20934217

  9. DNA Vaccines: Experiences in the Swine Model.

    PubMed

    Accensi, Francesc; Rodríguez, Fernando; Monteagudo, Paula L

    2016-01-01

    DNA vaccination is one of the most fascinating vaccine-strategies currently in development. Two of the main advantages of DNA immunization rely on its simplicity and flexibility, being ideal to dissect both the immune mechanisms and the antigens involved in protection against a given pathogen. Here, we describe several strategies used to enhance the immune responses induced and the protection afforded by experimental DNA vaccines tested in swine and provide with very basic protocol describing the generation and in vivo application of a prototypic DNA vaccine. Only time will tell the last word regarding the definitive implementation of DNA vaccination in the field. PMID:26458829

  10. Enhancement of the immunogenicity of an infectious laryngotracheitis virus DNA vaccine by a bicistronic plasmid encoding glycoprotein B and interleukin-18.

    PubMed

    Chen, Hong-Ying; Zhao, Li; Wei, Zhan-Yong; Cui, Bao-An; Wang, Zhen-Ya; Li, Xin-Sheng; Xia, Ping-An; Liu, Jin-Peng

    2010-08-01

    A DNA vaccine against infectious laryngotracheitis virus (ILTV) can induce specific humoral and cell-mediated immunity. However, compared to conventional vaccines, DNA vaccines usually induce poor antibody responses. To determine if co-expression of a cytokine can result in a more potent ILTV DNA vaccine, immunogenicity and protective efficacy of a monocistronic vector encoding the glycoprotein B (gB) of ILTV was compared to that of a bicistronic vector separately encoding the gB and chicken interleukin-18. Humoral and cellular responses induced by the DNA vaccines administered to the quadriceps muscle of chickens were evaluated. There were significant differences in antibody levels elicited by either monocistronic or bicistronic DNA vaccines as determined by ELISA. The percentages of CD3(+), CD3(+)CD8(+) and CD3(+)CD4(+) subgroups of peripheral blood T-lymphocytes in chickens immunized with the bicistronic DNA vaccine were higher than those in chickens immunized with monocistronic DNA vaccine. When chickens were challenged with a virulent CG strain of ILTV, the protective efficacy was enhanced significantly after immunization with the bicistronic DNA vaccine. These results demonstrated that co-expression of an adjuvant cytokine from a bicistronic DNA vaccine may be an effective approach to increasing ILTV DNA vaccine immunogenicity. PMID:20553764

  11. The MSHA strain of Pseudomonas aeruginosa activated TLR pathway and enhanced HIV-1 DNA vaccine immunoreactivity.

    PubMed

    Hou, Jue; Liu, Yong; Liu, Ying; Shao, Yiming

    2012-01-01

    The mannose-sensitive hemagglutination pilus strain of Pseudomonas aeruginosa (PA-MSHA) has been shown to trigger naïve immune responses through the activation of monocytes, macrophages, natural killer cells (NK cells) and antigen presenting cells (APCs). Based on the hypothesis that PA-MSHA activates natural immunity through the Toll-like receptor (TLR) pathway, we scanned several critical TLR pathway molecules in mouse splenocytes using high-throughput real-time QRT-PCR and co-stimulatory molecule in bone marrow-derived dendritic cells (BMDCs) following in vitro stimulation by PA-MSHA. PA-MSHA enabled activation of the TLR pathway mediated by NF-κB and JNK signaling in splenocytes, and the co-stimulatory molecule CD86 was up-regulated in BMDCs. We then assessed the adjuvant effect of PA-MSHA for HIV-1 DNA vaccines. In comparison to DNA inoculation alone, co-inoculation with low dosage of PA-MSHA enhanced specific immunoreactivity against HIV-1 Env in both cellular and humoral responses, and promoted antibody avidity maturation. However, high doses of adjuvant resulted in an immunosuppressive effect; a two- or three-inoculation regimen yielded low antibody responses and the two-inoculation regimen exhibited only a slight cellular immunity response. To our knowledge, this is the first report demonstrating the utility of PA-MSHA as an adjuvant to a DNA vaccine. Further research is needed to investigate the exact mechanisms through which PA-MSHA achieves its adjuvant effects on innate immune responses, especially on dendritic cells. PMID:23077664

  12. Fas Ligand DNA Enhances a Vaccination Effect by Coadministered DNA Encoding a Tumor Antigen through Augmenting Production of Antibody against the Tumor Antigen

    PubMed Central

    Zhong, Boya; Ma, Guangyu; Sato, Ayako; Shimozato, Osamu; Liu, Hongdan; Shingyoji, Masato; Tada, Yuji; Tatsumi, Koichiro; Shimada, Hideaki; Hiroshima, Kenzo; Tagawa, Masatoshi

    2015-01-01

    Interaction of Fas and Fas ligand (FasL) plays an important role in the regulation of immune responses by inducing apoptosis of activated cells; however, a possible role of FasL in DNA vaccination has not been well understood. We examined whether administration of DNA encoding FasL gene enhanced antitumor effects in mice that were vaccinated with DNA expressing a putative tumor antigen gene, β-galactosidase (β-gal). Growth of β-gal-positive Colon 26 tumors was retarded in the syngeneic mice immunized with β-gal and FasL DNA compared with those vaccinated with β-gal or FasL DNA. We did not detect increased numbers of β-gal-specific CD8+ T cells in lymph node of mice that received combination of β-gal and FasL DNA, but amounts of anti-β-gal antibody increased with the combination but not with β-gal or FasL DNA injection alone. Subtype analysis of anti-β-gal antibody produced by the combination of β-gal and FasL DNA or β-gal DNA injection showed that IgG2a amounts were greater in mice injected with both DNA than those with β-gal DNA alone, but IgG2b amounts were lower in both DNA-injected than β-gal DNA-injected mice. These data suggest that FasL is involved in boosting humoral immunity against a gene product encoded by coinjected DNA and enhances the vaccination effects. PMID:25759847

  13. Enhancement of DNA cancer vaccine efficacy by combination with anti-angiogenesis in regression of established subcutaneous B16 melanoma.

    PubMed

    Chan, Ray Chun-Fai; Gutierrez, Benjamin; Ichim, Thomas E; Lin, Feng

    2009-11-01

    Immunotherapy of cancer offers great promise, however translation into human studies has yielded relatively poor results to date. The concept of combining cancer vaccination with angiogenesis inhibition is appealing, due to favorable safety profile of both approaches, as well as possible biological synergies. Here we studied the anti-tumor effects of combining plasmid DNA (pDNA) vaccination and anti-angiogenesis in B16F10 murine model. By using electroporation-mediated gene/pDNA delivery, the anti-tumor efficacy of vaccination with pDNAs encoding gp100, TRP2 and Ii-PADRE was facilitated by administration of soluble form of EphB4 fused with human serum albumin (sEphB4-HSA), or by co-delivery of pDNAs encoding Angiostatin and/or Endostatin. In an optimized administration protocol, melanoma vaccination together with intratumoral delivery of pDNAs encoding Angiostatin and Endostatin resulted in 57% tumor-free survival over 90 days after challenge. These data support the general concept that suppression of angiogenesis may allow for enhanced efficacy of anti-tumor immunity, suggesting the synergetic effects of therapeutic pDNA vaccination and angiogenesis inhibition in cancer therapy. PMID:19787240

  14. Removing N-terminal sequences in pre-S1 domain enhanced antibody and B-cell responses by an HBV large surface antigen DNA vaccine.

    PubMed

    Ge, Guohong; Wang, Shixia; Han, Yaping; Zhang, Chunhua; Lu, Shan; Huang, Zuhu

    2012-01-01

    Although the use of recombinant hepatitis B virus surface (HBsAg) protein vaccine has successfully reduced global hepatitis B infection, there are still a number of vaccine recipients who do not develop detectable antibody responses. Various novel vaccination approaches, including DNA vaccines, have been used to further improve the coverage of vaccine protection. Our previous studies demonstrated that HBsAg-based DNA vaccines could induce both humoral and CMI responses in experimental animal models. However, one form of the the HBsAg antigen, the large S antigen (HBs-L), expressed by DNA vaccine, was not sufficiently immunogenic in eliciting antibody responses. In the current study, we produced a modified large S antigen DNA vaccine, HBs-L(T), which has a truncated N-terminal sequence in the pre-S1 region. Compared to the original HBs-L DNA vaccine, the HBs-L(T) DNA vaccine improved secretion in cultured mammalian cells and generated significantly enhanced HBsAg-specific antibody and B cell responses. Furthermore, this improved HBsL DNA vaccine, along with other HBsAg-expressing DNA vaccines, was able to maintain predominantly Th1 type antibody responses while recombinant HBsAg protein vaccines produced in either yeast or CHO cells elicited mostly Th2 type antibody responses. Our data indicate that HBsAg DNA vaccines with improved immunogenicity offer a useful alternative choice to recombinant protein-based HBV vaccines, particularly for therapeutic purposes against chronic hepatitis infection where immune tolerance led to poor antibody responses to S antigens. PMID:22844502

  15. Co-administration of antigen with chemokine MCP-3 or MDC/CCL22 enhances DNA vaccine potency.

    PubMed

    Xie, Xinmei; Wang, Lin; Yang, Wenliang; Yu, Ruishuang; Li, Qingli; Pang, Xiaobin

    2015-08-01

    We evaluated the utility of chemokine MCP-3 and MDC/CCL22 as molecular adjuvants of DNA vaccines for botulinum neurotoxin serotype A (BoNT/A) in a Balb/c mouse model. Notably, the immunogenicity of the DNA vaccine against BoNT/A was not enhanced using a fusion of the AHc-C antigen with the MCP-3 or MDC/CCL22. Nevertheless, the potency of the DNA vaccine was significantly modulated and enhanced by co-administration of the AHc-C antigen with MCP-3 or MDC/CCL22. This strategy elicited high levels of humoral immune responses and protection against BoNT/A. The enhanced potency was further boosted by co-administration of the AHc-C antigen with both MCP-3 and MDC/CCL22 in Balb/c mice, but not by co-administration of AHc-C antigen with the MCP-3-MDC/CCL22 fusion. Co-immunization with both the MCP-3 and MDC/CCL22 constructs induced the highest levels of humoral immunity and protective potency against BoNT/A. Our results indicated that MCP-3 and MDC/CCL22 are effective molecular adjuvants of the immune responses induced by the AHc-C-expressing DNA vaccine when delivered by co-administration of the individual chemokines, but not when delivered in the form of a chemokine/antigen fusion. Thus, we describe an alternative strategy to the design and optimization of DNA vaccine constructs based on co-administration of the antigen with the chemokine rather than in the form of a chemokine/antigen fusion. PMID:25952465

  16. Immunogenicity of a novel enhanced consensus DNA vaccine encoding the leptospiral protein LipL45

    PubMed Central

    Vijayachari, P; Vedhagiri, K; Mallilankaraman, K; Mathur, PP; Sardesai, NY; Weiner, DB; Ugen, KE; Muthumani, K

    2015-01-01

    Leptospirosis is a bacterial zoonotic disease caused by an infection with a spirochete belonging to the genus Leptospira. In animals, leptospirosis displays a wide range of pathologies, including fever, abortion, icterus, and uveitis. Conversely, infection in humans is associated with multi-organ injury, resulting in an increased rate of fatalities. Pathogenic leptospires are able to translocate through cell monolayers at a rate significantly greater than that of non-pathogenic leptospires. Thus, vaccine approaches have been focused on targeting bacterial motility, lipopolysaccharides (LPSs), lipoproteins, outer-membrane proteins (OMPs) and other potential virulence factors. Previous studies have indicated that leptospiral proteins elicit long-lasting immunological memory in infected humans. In the study reported here, the efficacy of a synthetic consensus DNA vaccine developed against the Leptospira membrane lipoprotein LipL45 was tested. After in vivo electroporation (EP) mediated intramuscular immunization with a synthetic LipL45 DNA vaccine (pLipL45) immunized mice developed a significant cellular response along with the development of anti-LipL45-specific antibodies. Specifically, the pLipL45 vaccine induced a significant Th1 type immune response, indicated by the higher production of IL-12 and IFN-γ cytokines. The results presented here are the first demonstration that a LipL45 based DNA immunogen has potential as a anti-Leptospira vaccine. PMID:26020621

  17. GITRL as a genetic adjuvant enhances enterovirus 71 VP1 DNA vaccine immunogenicity.

    PubMed

    Yuan, Jing; Tang, Xinyi; Yin, Kai; Tian, Jie; Rui, Ke; Ma, Jie; Mao, Chaoming; Chen, Jianguo; Lu, Liwei; Xu, Huaxi; Wang, Shengjun

    2015-05-01

    VP1 protein is the immunodominant capsid protein of enterovirus 71 (EV71) which is responsible for large outbreaks of hand, foot and mouth disease. It has been reported that glucocorticoid-induced tumor necrosis factor receptor-related protein (GITR) and its ligand (GITRL) are involved in modulating both innate and adaptive immune responses. In this study, a DNA vaccine vector encoding EV71 VP1 gene and mGITRL gene (pIRES/VP1/mGITRL) was constructed. And female Balb/c mice were immunized intramuscularly with the DNA vaccine. Compared with the groups immunized with pIRES, pIRES/VP1, pIRES/mGITRL and PBS, the inoculation of pIRES/VP1/mGITRL induced a higher levels of EV71 VP1-specific antibody and specific antibody-forming cells. However, significantly higher levels of CD4(+)Th1, Th2 and CD8(+)IFN-γ(+)T cells were found in the pIRES/VP1/mGITRL group compared with control groups. Our results demonstrate that a novel DNA vaccine, expressing VP1 and mGITRL, could effectively elicit both humoral and cell-mediated immune responses against EV71 VP1 in mice. Thus, the mGITRL may be used as molecular adjuvant for EV71 DNA vaccine. PMID:25772201

  18. DNA vaccines against infectious agents: recent strategies for enhancing immune responses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There have been widespread efforts to develop plasmid DNA vaccines against animal and human pathogens, and for use as therapies in the treatment of cancers, autoimmune diseases, and allergies. The impetus for this research activity was based on early promising results in laboratory animals that sho...

  19. Combined virus-like particle and fusion protein-encoding DNA vaccination of cotton rats induces protection against respiratory syncytial virus without causing vaccine-enhanced disease.

    PubMed

    Hwang, Hye Suk; Lee, Young-Tae; Kim, Ki-Hye; Park, Soojin; Kwon, Young-Man; Lee, Youri; Ko, Eun-Ju; Jung, Yu-Jin; Lee, Jong Seok; Kim, Yu-Jin; Lee, Yu-Na; Kim, Min-Chul; Cho, Minkyoung; Kang, Sang-Moo

    2016-07-01

    A safe and effective vaccine against respiratory syncytial virus (RSV) should confer protection without causing vaccine-enhanced disease. Here, using a cotton rat model, we investigated the protective efficacy and safety of an RSV combination vaccine composed of F-encoding plasmid DNA and virus-like particles containing RSV fusion (F) and attachment (G) glycoproteins (FFG-VLP). Cotton rats with FFG-VLP vaccination controlled lung viral replication below the detection limit, and effectively induced neutralizing activity and antibody-secreting cell responses. In comparison with formalin inactivated RSV (FI-RSV) causing severe RSV disease after challenge, FFG-VLP vaccination did not cause weight loss, airway hyper-responsiveness, IL-4 cytokines, histopathology, and infiltrates of proinflammatory cells such as eosinophils. FFG-VLP was even more effective in preventing RSV-induced pulmonary inflammation than live RSV infections. This study provides evidence that FFG-VLP can be developed into a safe and effective RSV vaccine candidate. PMID:27123586

  20. Coexpressed RIG-I agonist enhances humoral immune response to influenza virus DNA vaccine.

    PubMed

    Luke, Jeremy M; Simon, Gregory G; Söderholm, Jonas; Errett, John S; August, J Thomas; Gale, Michael; Hodgson, Clague P; Williams, James A

    2011-02-01

    Increasing levels of plasmid vector-mediated activation of innate immune signaling pathways is an approach to improve DNA vaccine-induced adaptive immunity for infectious disease and cancer applications. Retinoic acid-inducible gene I (RIG-I) is a critical cytoplasmic double-stranded RNA (dsRNA) pattern receptor required for innate immune activation in response to viral infection. Activation of RIG-I leads to type I interferon (IFN) and inflammatory cytokine production through interferon promoter stimulator 1 (IPS-1)-mediated activation of interferon regulatory factor 3 (IRF3) and NF-κB signaling. DNA vaccines coexpressing antigen and an expressed RNA (eRNA) RIG-I agonist were made, and the effect of RIG-I activation on antigen-specific immune responses to the encoded antigen was determined. Plasmid vector backbones expressing various RIG-I ligands from RNA polymerase III promoters were screened in a cell culture assay for RIG-I agonist activity, and optimized, potent RIG-I ligands were developed. One of these, eRNA41H, combines (i) eRNA11a, an immunostimulatory dsRNA expressed by convergent transcription, with (ii) adenovirus VA RNAI. eRNA41H was integrated into the backbone of DNA vaccine vectors expressing H5N1 influenza virus hemagglutinin (HA). The resultant eRNA vectors potently induced type 1 IFN production in cell culture through RIG-I activation and combined high-level HA antigen expression with RNA-mediated type I IFN activation in a single plasmid vector. The eRNA vectors induced increased HA-specific serum antibody binding avidity after naked DNA intramuscular prime and boost delivery in mice. This demonstrates that DNA vaccine potency may be augmented by the incorporation of RIG-I-activating immunostimulatory RNA into the vector backbone. PMID:21106745

  1. Immune-Enhancing Effects of Taishan Pinus massoniana Pollen Polysaccharides on DNA Vaccine Expressing Bordetella avium ompA.

    PubMed

    Zhu, Fujie; Liu, Xiao; Sun, Zhenhong; Yu, Cuilian; Liu, Liping; Yang, Shifa; Li, Bing; Wei, Kai; Zhu, Ruiliang

    2016-01-01

    Bordetella avium is the causative agent of bordetellosis, which remains to be the cause of severe losses in the turkey industry. Given the lack of vaccines that can provide good protection, developing a novel vaccine against B. avium infection is crucial. In this study, we constructed a eukaryotic expression plasmid, which expressed the outer membrane protein A (ompA) of B. avium, to prepare a B. avium recombinant ompA-DNA vaccine. Three concentrations (low, middle, and high) of Taishan Pinus massoniana pollen polysaccharides (TPPPS), a known immunomodulator, were used as adjuvants, and their immune conditioning effects on the developed DNA vaccine were examined. The pure ompA-DNA vaccine, Freund's incomplete adjuvant ompA-DNA vaccine, and the empty plasmid served as the controls. The chickens in each group were separately inoculated with these vaccines three times at 1, 7, and 14 days old. Dynamic changes in antibody production, cytokine secretion, and lymphocyte count were then determined from 7 to 49 days after the first inoculation. Protective rates of the vaccines were also determined after the third inoculation. Results showed that the pure DNA vaccine obviously induced the production of antibodies, the secretion of cytokines, and the increase in CD(4+) and CD(8+) T lymphocyte counts in peripheral blood, as well as provided a protective rate of 50% to the B. avium-challenged chickens. The chickens inoculated with the TPPPS adjuvant ompA-DNA vaccine and Freund's adjuvant ompA-DNA vaccine demonstrated higher levels of immune responses than those inoculated with pure ompA-DNA vaccine, whereas only the ompA-DNA vaccine with 200 mg/mL TPPPS completely protected the chickens against B. avium infection. These findings indicate that the B. avium ompA-DNA vaccine combined with TPPPS is a potentially effective B. avium vaccine. PMID:26870023

  2. Immune-Enhancing Effects of Taishan Pinus massoniana Pollen Polysaccharides on DNA Vaccine Expressing Bordetella avium ompA

    PubMed Central

    Zhu, Fujie; Liu, Xiao; Sun, Zhenhong; Yu, Cuilian; Liu, Liping; Yang, Shifa; Li, Bing; Wei, Kai; Zhu, Ruiliang

    2016-01-01

    Bordetella avium is the causative agent of bordetellosis, which remains to be the cause of severe losses in the turkey industry. Given the lack of vaccines that can provide good protection, developing a novel vaccine against B. avium infection is crucial. In this study, we constructed a eukaryotic expression plasmid, which expressed the outer membrane protein A (ompA) of B. avium, to prepare a B. avium recombinant ompA-DNA vaccine. Three concentrations (low, middle, and high) of Taishan Pinus massoniana pollen polysaccharides (TPPPS), a known immunomodulator, were used as adjuvants, and their immune conditioning effects on the developed DNA vaccine were examined. The pure ompA-DNA vaccine, Freund’s incomplete adjuvant ompA-DNA vaccine, and the empty plasmid served as the controls. The chickens in each group were separately inoculated with these vaccines three times at 1, 7, and 14 days old. Dynamic changes in antibody production, cytokine secretion, and lymphocyte count were then determined from 7 to 49 days after the first inoculation. Protective rates of the vaccines were also determined after the third inoculation. Results showed that the pure DNA vaccine obviously induced the production of antibodies, the secretion of cytokines, and the increase in CD4+ and CD8+ T lymphocyte counts in peripheral blood, as well as provided a protective rate of 50% to the B. avium-challenged chickens. The chickens inoculated with the TPPPS adjuvant ompA-DNA vaccine and Freund’s adjuvant ompA-DNA vaccine demonstrated higher levels of immune responses than those inoculated with pure ompA-DNA vaccine, whereas only the ompA-DNA vaccine with 200 mg/mL TPPPS completely protected the chickens against B. avium infection. These findings indicate that the B. avium ompA-DNA vaccine combined with TPPPS is a potentially effective B. avium vaccine. PMID:26870023

  3. Mutual enhancement of IL-2 and IL-7 on DNA vaccine immunogenicity mainly involves regulations on their receptor expression and receptor-expressing lymphocyte generation.

    PubMed

    Zhang, Yonghong; Liang, Shuang; Li, Xiujin; Wang, Liyue; Zhang, Jianlou; Xu, Jian; Huo, Shanshan; Cao, Xuebin; Zhong, Zhenyu; Zhong, Fei

    2015-07-01

    Our previous study showed that IL-2 and IL-7 could mutually enhance the immunogenicity of canine parvovirus VP2 DNA vaccine, although the underlying mechanism remained unknown. Here, we used the OVA gene as a DNA vaccine in a mouse model to test their enhancement on DNA vaccine immunogenicity and to explore the molecular mechanism. Results showed that both IL-2 and IL-7 genes significantly increased the immunogenicity of OVA DNA vaccine in mice. Co-administration of IL-2 and IL-7 genes with OVA DNA significantly increased OVA-specific antibody titers, T cell proliferation and IFN-γ production compared with IL-2 or IL-7 alone, confirming that IL-2 and IL-7 mutually enhanced DNA vaccine immunogenicity. Mechanistically, we have shown that IL-2 significantly stimulated generation of IL-7 receptor-expressing lymphocytes, and that IL-7 significantly induced IL-2 receptor expression. These results contribute to an explanation of the mechanism of the mutual effects of IL-2 and IL-7 on enhancing DNA vaccine immunogenicity and provided a basis for further investigation on their mutual effects on adjuvant activity and immune regulation. PMID:26055295

  4. Enhanced Immune Response to DNA Vaccine Encoding Bacillus anthracis PA-D4 Protects Mice against Anthrax Spore Challenge.

    PubMed

    Kim, Na Young; Chang, Dong Suk; Kim, Yeonsu; Kim, Chang Hwan; Hur, Gyeung Haeng; Yang, Jai Myung; Shin, Sungho

    2015-01-01

    Anthrax has long been considered the most probable bioweapon-induced disease. The protective antigen (PA) of Bacillus anthracis plays a crucial role in the pathogenesis of anthrax. In the current study, we evaluated the efficiency of a genetic vaccination with the fourth domain (D4) of PA, which is responsible for initial binding of the anthrax toxin to the cellular receptor. The eukaryotic expression vector was designed with the immunoglobulin M (IgM) signal sequence encoding for PA-D4, which contains codon-optimized genes. The expression and secretion of recombinant protein was confirmed in vitro in 293T cells transfected with plasmid and detected by western blotting, confocal microscopy, and enzyme-linked immunosorbent assay (ELISA). The results revealed that PA-D4 protein can be efficiently expressed and secreted at high levels into the culture medium. When plasmid DNA was given intramuscularly to mice, a significant PA-D4-specific antibody response was induced. Importantly, high titers of antibodies were maintained for nearly 1 year. Furthermore, incorporation of the SV40 enhancer in the plasmid DNA resulted in approximately a 15-fold increase in serum antibody levels in comparison with the plasmid without enhancer. The antibodies produced were predominantly the immunoglobulin G2 (IgG2) type, indicating the predominance of the Th1 response. In addition, splenocytes collected from immunized mice produced PA-D4-specific interferon gamma (IFN-γ). The biodistribution study showed that plasmid DNA was detected in most organs and it rapidly cleared from the injection site. Finally, DNA vaccination with electroporation induced a significant increase in immunogenicity and successfully protected the mice against anthrax spore challenge. Our approach to enhancing the immune response contributes to the development of DNA vaccines against anthrax and other biothreats. PMID:26430894

  5. Enhanced Immune Response to DNA Vaccine Encoding Bacillus anthracis PA-D4 Protects Mice against Anthrax Spore Challenge

    PubMed Central

    Kim, Na Young; Chang, Dong Suk; Kim, Yeonsu; Kim, Chang Hwan; Hur, Gyeung Haeng; Yang, Jai Myung; Shin, Sungho

    2015-01-01

    Anthrax has long been considered the most probable bioweapon-induced disease. The protective antigen (PA) of Bacillus anthracis plays a crucial role in the pathogenesis of anthrax. In the current study, we evaluated the efficiency of a genetic vaccination with the fourth domain (D4) of PA, which is responsible for initial binding of the anthrax toxin to the cellular receptor. The eukaryotic expression vector was designed with the immunoglobulin M (IgM) signal sequence encoding for PA-D4, which contains codon-optimized genes. The expression and secretion of recombinant protein was confirmed in vitro in 293T cells transfected with plasmid and detected by western blotting, confocal microscopy, and enzyme-linked immunosorbent assay (ELISA). The results revealed that PA-D4 protein can be efficiently expressed and secreted at high levels into the culture medium. When plasmid DNA was given intramuscularly to mice, a significant PA-D4-specific antibody response was induced. Importantly, high titers of antibodies were maintained for nearly 1 year. Furthermore, incorporation of the SV40 enhancer in the plasmid DNA resulted in approximately a 15-fold increase in serum antibody levels in comparison with the plasmid without enhancer. The antibodies produced were predominantly the immunoglobulin G2 (IgG2) type, indicating the predominance of the Th1 response. In addition, splenocytes collected from immunized mice produced PA-D4-specific interferon gamma (IFN-γ). The biodistribution study showed that plasmid DNA was detected in most organs and it rapidly cleared from the injection site. Finally, DNA vaccination with electroporation induced a significant increase in immunogenicity and successfully protected the mice against anthrax spore challenge. Our approach to enhancing the immune response contributes to the development of DNA vaccines against anthrax and other biothreats. PMID:26430894

  6. Targeting with bovine CD154 enhances humoral immune responses induced by a DNA vaccine in sheep.

    PubMed

    Manoj, Sharmila; Griebel, Philip J; Babiuk, Lorne A; van Drunen Littel-van den Hurk, Sylvia

    2003-01-15

    CD40-CD154 interactions play an important role in regulating humoral and cell-mediated immune responses. Recently, these interactions have been exploited for the development of therapeutic and preventive treatments. The objective of this study was to test the ability of bovine CD154 to target a plasmid-encoded Ag to CD40-expressing APCs. To achieve this, a plasmid coding for bovine CD154 fused to a truncated secreted form of bovine herpesvirus 1 glycoprotein D (tgD), pSLIAtgD-CD154, was constructed. The chimeric tgD-CD154 was expressed in vitro in COS-7 cells and reacted with both glycoprotein D- and CD154-specific Abs. Both tgD and tgD-CD154 were capable of binding to epithelial cells, whereas only tgD-CD154 bound to B cells. Furthermore, dual-labeling of ovine PBMCs revealed that tgD-CD154 was bound by primarily B cells. The functional integrity of the tgD-CD154 chimera was confirmed by the induction of both IL-4-dependent B cell proliferation and tgD-specific lymphoproliferative responses in vitro. Finally, sheep immunized with pSLIAtgD-CD154 developed a more rapid primary tgD-specific Ab response and a significantly stronger tgD-specific secondary response when compared with animals immunized with pSLIAtgD and control animals. Similarly, virus-neutralizing Ab titers were significantly higher after secondary immunization with pSLIAtgD-CD154. These results demonstrate that using CD154 to target plasmid-expressed Ag can significantly enhance immune responses induced by a DNA vaccine. PMID:12517965

  7. DNA vaccines in veterinary use

    PubMed Central

    Redding, Laurel; Werner, David B

    2015-01-01

    DNA vaccines represent a new frontier in vaccine technology. One important application of this technology is in the veterinary arena. DNA vaccines have already gained a foothold in certain fields of veterinary medicine. However, several important questions must be addressed when developing DNA vaccines for animals, including whether or not the vaccine is efficacious and cost effective compared with currently available options. Another important question to consider is how to apply this developing technology in a wide range of different situations, from the domestic pet to individual fish in fisheries with several thousand animals, to wildlife programs for disease control. In some cases, DNA vaccines represent an interesting option for vaccination, while in others, currently available options are sufficient. This review will examine a number of diseases of veterinary importance and the progress being made in DNA vaccine technology relevant to these diseases, and we compare these with the conventional treatment options available. PMID:19722897

  8. DNA vaccination based on pyolysin co-immunized with IL-1β enhances host antibacterial immunity against Trueperella pyogenes infection.

    PubMed

    Huang, Ting; Zhao, Kelei; Zhang, Ziqi; Tang, Ce; Zhang, Xiuyue; Yue, Bisong

    2016-06-24

    Trueperella pyogenes is a commensal and opportunistic pathogen normally causes mastitis, liver abscesses and pneumonia of economically important livestock. To date, no specific control measure was reported to prevent T. pyogenes infections. In this study, we first constructed a recombinant plasmid pVAX1-PLO based on the main virulent factor pyolysin gene as DNA vaccine against T. pyogenes infection. Subsequently, transient expression of pVAX1-PLO and pcDNA3.1/V5-fIL-1β were identified in Human embryonic kidney cells (HEK293T) by immunofluorescence assay. Humoral and cellular immune responses were evaluated in mice to compare the immunogenicity between different immunized groups. The results showed that the successful expression of PLO or fIL-1β protein was detected by confocal microscopy for cells transfected with plasmid pVAX1-PLO and/or pcDNA3.1/V5-fIL-1β. The mice immunized with pVAX1-PLO elicited a higher titer of PLO-specific antibody than the control group. The levels of IFN-γ and IL-2 were significantly increased in the pVAX1-PLO immunized mice, while the expression level of IL-4 was slightly increased but not significant. These findings suggested that the DNA vaccine pVAX1-PLO can primarily induce Th1 immune response. The residual Colony-Forming Units (CFUs) from the liver and peritoneal fluid were decreased obviously in the pVAX1-PLO treated mice compared with the control. Importantly, co-immunization with pcDNA3.1/V5-fIL-1β and pVAX1-PLO could enhance host humoral and cellular immune responses and significantly protect mouse from T. pyogenes infection. In conclusion, our study provides a promising strategy against T. pyogenes infections and implies the potential clinical application of combined DNA vaccines in diseases control. PMID:27091688

  9. Vaccination with a fusion DNA vaccine encoding hepatitis B surface antigen fused to the extracellular domain of CTLA4 enhances HBV-specific immune responses in mice: implication of its potential use as a therapeutic vaccine.

    PubMed

    Zhou, Cheng; Peng, Guoping; Jin, Xiaoli; Tang, Jie; Chen, Zhi

    2010-11-01

    Fusion of specific antigens to extracellular domain of cytotoxic-T-lymphocyte-associated antigen 4 (CTLA4) represents a promising approach to increase the immunogenicity of DNA vaccines. We evaluated this interesting approach for its enhancement on HBV-specific immune responses and its antiviral effects in HBV transgenic mice. A fusion plasmid encoding the extracellular domain of CTLA4 linked with HBsAg was constructed. Mice were immunized by this fusion plasmid. Vaccination with the CTLA4-fused DNA not only induced much higher level of anti-HBs antibody, but also increased HBsAg-specific CD8+ response as well as CTL response in BALB/c mice. Furthermore, both Th1 and Th2 responses were augmented. In HBV transgenic mice, the levels of circulating HBsAg and HBV DNA replication were down-regulated by induction of higher anti-HBs antibody and HBsAg-specific CD8+ response after vaccination with the fusion plasmid. Thus, the CTLA4-fused DNA vaccine led to breakdown of immune tolerance to viral infection in HBV transgenic mice, which might be used as a therapeutic vaccine in HBV infection. PMID:20692873

  10. Molecular adjuvant IL-33 enhances the potency of a DNA vaccine in a lethal challenge model

    PubMed Central

    Villarreal, Daniel O.; Svoronos, Nikos; Wise, Megan C.; Shedlock, Devon J.; Morrow, Matthew P.; Garcia, Jose-Conejo; Weiner, David B.

    2015-01-01

    Identifying new molecular adjuvants that elicit effective vaccine-induced CD8+ T cell immunity may be critical for the elimination of many challenging diseases including Tuberculosis, HIV and cancer. Here, we report that co-administration of molecular adjuvant IL-33 during vaccination enhanced the magnitude and function of antigen (Ag)-specific CD8+ T cells against a model Ag, LCMV NP target protein. These enhanced responses were characterized by higher frequencies of Ag-specific, polyfunctional CD8+ T cells exhibiting cytotoxic characteristics. Importantly, these cells were capable of robust expansion upon Ag-specific restimulation in vivo and conferred remarkable protection against a high dose lethal LCMV challenge. In addition, we demonstrate the ability of IL-33 to amplifying the frequency of Ag-specific KLRG1+ effector CD8+ T cells. These data show that IL-33 is a promising immunoadjuvant at improving T cell immunity in a vaccine setting and suggest further development and understanding of this molecular adjuvant for strategies against many obstinate infectious diseases and cancer. PMID:25887087

  11. Molecular adjuvant IL-33 enhances the potency of a DNA vaccine in a lethal challenge model.

    PubMed

    Villarreal, Daniel O; Svoronos, Nikolaos; Wise, Megan C; Shedlock, Devon J; Morrow, Matthew P; Conejo-Garcia, Jose R; Weiner, David B

    2015-08-20

    Identifying new molecular adjuvants that elicit effective vaccine-induced CD8(+) T cell immunity may be critical for the elimination of many challenging diseases including Tuberculosis, HIV and cancer. Here, we report that co-administration of molecular adjuvant IL-33 during vaccination enhanced the magnitude and function of antigen (Ag)-specific CD8(+) T cells against a model Ag, LCMV NP target protein. These enhanced responses were characterized by higher frequencies of Ag-specific, polyfunctional CD8(+) T cells exhibiting cytotoxic characteristics. Importantly, these cells were capable of robust expansion upon Ag-specific restimulation in vivo and conferred remarkable protection against a high dose lethal LCMV challenge. In addition, we demonstrate the ability of IL-33 to amplifying the frequency of Ag-specific KLRG1(+) effector CD8(+) T cells. These data show that IL-33 is a promising immunoadjuvant at improving T cell immunity in a vaccine setting and suggest further development and understanding of this molecular adjuvant for strategies against many obstinate infectious diseases and cancer. PMID:25887087

  12. Enhancing immune responses of EV71 VP1 DNA vaccine by co-inoculating plasmid IL-12 or GM-CSF expressing vector in mice.

    PubMed

    Peng, X; Fang, X; Li, J; Kong, L; Li, B; Ding, X

    2016-01-01

    Enterovirus 71 (EV71) is a major causative viral agent for large outbreaks of hand, foot, and mouth disease in children and infants, yet there is no vaccine or effective antiviral treatment for severe EV71 infection. The immunogenicity of EV71 VP1 DNA vaccine and the immunoregulatory activity of interleukin-12 (IL-12) or granulocyte-monocyte colony stimulating factor (GM-CSF) were investigated. DNA vaccine plasmids, pcDNA-VP1, pcDNA-IL-12 and pcDNA-GM-CSF were constructed and inoculated into BALB/c mice with or without pcDNA-IL-12 or pcDNA-GM-CSF by intramuscular injection. Cellular and humoral immune responses were assessed by indirect ELISA, lymphocyte proliferation assays, cytokine release assay and FACS. The VP1 DNA vaccine had good immunogenicity and can induce specific humoral and cellular immunity in BALB/c mice, while IL-2 or GM-CSF plays an immunoadjuvant role and enhances specific immune responses. This study provides a frame of reference for the design of DNA vaccines against EV71. PMID:27188732

  13. Boosting BCG-primed mice with chimeric DNA vaccine HG856A induces potent multifunctional T cell responses and enhanced protection against Mycobacterium tuberculosis.

    PubMed

    Ji, Ping; Hu, Zhi-Dong; Kang, Han; Yuan, Qin; Ma, Hui; Wen, Han-Li; Wu, Juan; Li, Zhong-Ming; Lowrie, Douglas B; Fan, Xiao-Yong

    2016-02-01

    The tuberculosis pandemic continues to rampage despite widespread use of the current Bacillus Calmette-Guerin (BCG) vaccine. Because DNA vaccines can elicit effective antigen-specific immune responses, including potent T cell-mediated immunity, they are promising vehicles for antigen delivery. In a prime-boost approach, they can supplement the inadequate anti-TB immunological memory induced by BCG. Based on this, a chimeric DNA vaccine HG856A encoding Mycobacterium tuberculosis (M. tuberculosis) immunodominant antigen Ag85A plus two copies of ESAT-6 was constructed. Potent humoral immune responses, as well as therapeutic effects induced by this DNA vaccine, were observed previously in M. tuberculosis-infected mice. In this study, we further evaluated the antigen-specific T cell immune responses and showed that repeated immunization with HG856A gave modest protection against M. tuberculosis challenge infection and significantly boosted the immune protection primed by BCG vaccination. Enhanced protection was accompanied by increased multifunctional Th1 CD4(+) T cell responses, most notably by an elevated frequency of M. tuberculosis antigen-specific IL-2-producing CD4(+) T cells post-vaccination. These data confirm the potential of chimeric DNA vaccine HG856A as an anti-TB vaccine candidate. PMID:26111521

  14. Micro- and nanoparticulates for DNA vaccine delivery.

    PubMed

    Farris, Eric; Brown, Deborah M; Ramer-Tait, Amanda E; Pannier, Angela K

    2016-05-01

    DNA vaccination has emerged as a promising alternative to traditional protein-based vaccines for the induction of protective immune responses. DNA vaccines offer several advantages over traditional vaccines, including increased stability, rapid and inexpensive production, and flexibility to produce vaccines for a wide variety of infectious diseases. However, the immunogenicity of DNA vaccines delivered as naked plasmid DNA is often weak due to degradation of the DNA by nucleases and inefficient delivery to immune cells. Therefore, biomaterial-based delivery systems based on micro- and nanoparticles that encapsulate plasmid DNA represent the most promising strategy for DNA vaccine delivery. Microparticulate delivery systems allow for passive targeting to antigen presenting cells through size exclusion and can allow for sustained presentation of DNA to cells through degradation and release of encapsulated vaccines. In contrast, nanoparticle encapsulation leads to increased internalization, overall greater transfection efficiency, and the ability to increase uptake across mucosal surfaces. Moreover, selection of the appropriate biomaterial can lead to increased immune stimulation and activation through triggering innate immune response receptors and target DNA to professional antigen presenting cells. Finally, the selection of materials with the appropriate properties to achieve efficient delivery through administration routes conducive to high patient compliance and capable of generating systemic and local (i.e. mucosal) immunity can lead to more effective humoral and cellular protective immune responses. In this review, we discuss the development of novel biomaterial-based delivery systems to enhance the delivery of DNA vaccines through various routes of administration and their implications for generating immune responses. PMID:27048557

  15. CpG adjuvant enhances the mucosal immunogenicity and efficacy of a Treponema pallidum DNA vaccine in rabbits

    PubMed Central

    Zhao, Feijun; Liu, Shuangquan; Zhang, Xiaohong; Yu, Jian; Zeng, Tiebing; Gu, Weiming; Cao, Xunyu; Chen, Xi; Wu, Yimou

    2013-01-01

    Objectives: The protective response against Treponema pallidum (Tp) infection of a DNA vaccine enhanced by an adjuvant CpG ODN was investigated. Results: The mucosal adjuvant CpG ODN enhanced the production of higher levels of anti-TpGpd antibodies induced by pcD/Gpd-IL-2 in rabbits. It also resulted in higher levels of secretion of IL-2 and IFN-γ, and facilitated T cell proliferation and differentiation (p < 0.05). No significant difference about testing index above-mentioned was found in the intranasal immunization group of pcD/Gpd-IL-2 vaccine adjuvanted by CpG ODN when compared with the immunization by pcD/Gpd-IL-2 vaccine intramuscular injection alone (p > 0.05). Furthermore, CpG ODN stimulated the production of mucosa-specific anti-sIgA antibodies and resulted in the lowest Tp-positive rate (6.7%) for Tp-infection of skin lesions and the lowest rates (8.3%) of ulceration lesions, thus achieving better protective effects. Methods: New Zealand rabbits were immunized with the eukaryotic vector encoding recombinant pcD/Gpd-IL-2 using intramuscular multi-injection or together with mucosal enhancement via a nasal route. The effect of the mucosal adjuvant CpG ODN was examined. Conclusions:The CpG ODN adjuvant significantly enhances the humoral and cellular immune effects of the immunization by pcD/Gpd-IL-2 with mucosal enhancement via nasal route. It also stimulates strong mucosal immune effects, thus initiating more efficient immune-protective effects. PMID:23563515

  16. Enhanced Efficacy of a Codon-Optimized DNA Vaccine Encoding the Glycoprotein Precursor Gene of Lassa Virus in a Guinea Pig Disease Model When Delivered by Dermal Electroporation

    PubMed Central

    Cashman, Kathleen A.; Broderick, Kate E.; Wilkinson, Eric R.; Shaia, Carl I.; Bell, Todd M.; Shurtleff, Amy C.; Spik, Kristin W.; Badger, Catherine V.; Guttieri, Mary C.; Sardesai, Niranjan Y.; Schmaljohn, Connie S.

    2013-01-01

    Lassa virus (LASV) causes a severe, often fatal, hemorrhagic fever endemic to West Africa. Presently, there are no FDA-licensed medical countermeasures for this disease. In a pilot study, we constructed a DNA vaccine (pLASV-GPC) that expressed the LASV glycoprotein precursor gene (GPC). This plasmid was used to vaccinate guinea pigs (GPs) using intramuscular electroporation as the delivery platform. Vaccinated GPs were protected from lethal infection (5/6) with LASV compared to the controls. However, vaccinated GPs experienced transient viremia after challenge, although lower than the mock-vaccinated controls. In a follow-on study, we developed a new device that allowed for both the vaccine and electroporation pulse to be delivered to the dermis. We also codon-optimized the GPC sequence of the vaccine to enhance expression in GPs. Together, these innovations resulted in enhanced efficacy of the vaccine. Unlike the pilot study where neutralizing titers were not detected until after virus challenge, modest neutralizing titers were detected in guinea pigs before challenge, with escalating titers detected after challenge. The vaccinated GPs were never ill and were not viremic at any timepoint. The combination of the codon-optimized vaccine and dermal electroporation delivery is a worthy candidate for further development. PMID:26344112

  17. Enhanced Efficacy of a Codon-Optimized DNA Vaccine Encoding the Glycoprotein Precursor Gene of Lassa Virus in a Guinea Pig Disease Model When Delivered by Dermal Electroporation.

    PubMed

    Cashman, Kathleen A; Broderick, Kate E; Wilkinson, Eric R; Shaia, Carl I; Bell, Todd M; Shurtleff, Amy C; Spik, Kristin W; Badger, Catherine V; Guttieri, Mary C; Sardesai, Niranjan Y; Schmaljohn, Connie S

    2013-01-01

    Lassa virus (LASV) causes a severe, often fatal, hemorrhagic fever endemic to West Africa. Presently, there are no FDA-licensed medical countermeasures for this disease. In a pilot study, we constructed a DNA vaccine (pLASV-GPC) that expressed the LASV glycoprotein precursor gene (GPC). This plasmid was used to vaccinate guinea pigs (GPs) using intramuscular electroporation as the delivery platform. Vaccinated GPs were protected from lethal infection (5/6) with LASV compared to the controls. However, vaccinated GPs experienced transient viremia after challenge, although lower than the mock-vaccinated controls. In a follow-on study, we developed a new device that allowed for both the vaccine and electroporation pulse to be delivered to the dermis. We also codon-optimized the GPC sequence of the vaccine to enhance expression in GPs. Together, these innovations resulted in enhanced efficacy of the vaccine. Unlike the pilot study where neutralizing titers were not detected until after virus challenge, modest neutralizing titers were detected in guinea pigs before challenge, with escalating titers detected after challenge. The vaccinated GPs were never ill and were not viremic at any timepoint. The combination of the codon-optimized vaccine and dermal electroporation delivery is a worthy candidate for further development. PMID:26344112

  18. Interleukin-18-mediated enhancement of the protective effect of an infectious laryngotracheitis virus glycoprotein B plasmid DNA vaccine in chickens.

    PubMed

    Chen, Hong-Ying; Zhang, Hong-Ying; Li, Xin-Sheng; Cui, Bao-An; Wang, Shu-Juan; Geng, Jing-Wei; Li, Kun

    2011-01-01

    The immunogenicity of an infectious laryngotracheitis virus (ILTV) glycoprotein B (gB) plasmid DNA vaccine and the immunoregulatory activity of chicken interleukin-18 (IL-18) were investigated in a challenge model. Two recombinant plasmids, pcDNA3.1/gB (pgB) and pcDNA3.1/IL-18 (pIL-18), containing gB and IL-18 were constructed. Chickens were intramuscularly administered two immunizations 2 weeks apart, and challenged with the virulent CG strain of ILTV 2 weeks later. All animals vaccinated with pgB alone or with a combination of pgB plus pIL-18 developed a specific anti-ILTV ELISA antibody and splenocyte proliferation response. The ratios of CD4(+) to CD8(+) T lymphocytes in chickens immunized with pgB plus pIL-18 were significantly higher than in those immunized with pgB alone. Co-injection of pIL-18 significantly increased the production of gamma interferon and IL-2, indicating that IL-18 enhances the T helper 1-dominant immune response. Challenge experiments showed that the morbidity rate in the pgB group (25  %) was significantly higher than that in the pgB plus pIL-18 group (10  %). The mortality rates in the pgB and pgB plus pIL-18 groups were 10 and 0 %, respectively, and the corresponding protection rates were 60 and 80  %. These results indicate that IL-18 may be an effective adjuvant for an ILTV vaccine. PMID:20829398

  19. Adjuvanting a DNA vaccine with a TLR9 ligand plus Flt3 ligand results in enhanced cellular immunity against the simian immunodeficiency virus.

    PubMed

    Kwissa, Marcin; Amara, Rama R; Robinson, Harriet L; Moss, Bernard; Alkan, Sefik; Jabbar, Abdul; Villinger, Francois; Pulendran, Bali

    2007-10-29

    DNA vaccines offer promising strategies for immunization against infections. However, their clinical use requires improvements in immunogenicity. We explored the efficacy of Toll-like receptor (TLR) ligands (TLR-Ls) on augmenting the immunogenicity of a DNA prime-modified vaccinia virus Ankara (MVA) boost vaccine against SIV. Rhesus macaques were injected with Fms-like tyrosine kinase 3 (Flt3)-ligand (FL) to expand dendritic cells (DCs) and were primed with a DNA vaccine encoding immunodeficiency virus antigens mixed with ligands for TLR9 or TLR7/8. Subsequently, the animals were boosted with DNA and twice with recombinant MVA expressing the same antigens. TLR9-L (CpG DNA) mediated activation of DCs in vivo and enhanced the magnitude of antigen-specific CD8(+) interferon (IFN) gamma(+) T cells and polyfunctional CD8(+) T cells producing IFN-gamma, tumor necrosis factor alpha, and interleukin 2. Although this trial was designed primarily as an immunogenicity study, we challenged the animals with pathogenic SIVmac(251) and observed a reduction in peak viremia and cumulative viral loads in the TLR9-L plus FL-adjuvanted group relative to the unvaccinated group; however, the study design precluded comparisons between the adjuvanted groups and the group vaccinated with DNA/MVA alone. Viral loads were inversely correlated with the magnitude and quality of the immune response. Thus, the immunogenicity of DNA vaccines can be augmented with TLR9-L plus FL. PMID:17954572

  20. Enhancement of mucosal and cellular immune response in mice by vaccination with respiratory syncytial virus DNA encapsulated with transfersome.

    PubMed

    Xu, Jin; Ding, Yunzhen; Yang, Yi

    2008-12-01

    Respiratory syncytial virus (RSV) is one of the principal causes of bronchiolitis and pneumonia in young children, and currently there is no safe and effective vaccine. DNA vaccines encoding RSV surface glycoproteins are one option being examined. We evaluated the topical delivery of transfersome encapsulated DNA vaccine for its ability to confer protection against RSV challenge in mice and to determine whether such delivery could induce strong and specific immunity against RSV. After topical vaccination with a transfersome encapsulated RSV-F DNA, both RSV-specific mucosal antibody response and IFN-gamma-producing cells were detected. Intramuscular vaccination of naked RSV-F DNA only induced a significant anti-RSV IgG antibody response but no remarkable sIgA antibody and virus-specific cellular activity. Lungs from mice receiving topical vaccination had fewer histopathologic anomalies after RSV challenge than did mice receiving intramuscular vaccination or controls. Immunization with transfersome encapsulated F gene encoding DNA induces mucosal and cellular immune responses in mice that appear to produce protective immunity against respiratory syncytial virus. PMID:19115938

  1. Combinations of various CpG motifs cloned into plasmid backbone modulate and enhance protective immunity of viral replicon DNA anthrax vaccines.

    PubMed

    Yu, Yun-Zhou; Ma, Yao; Xu, Wen-Hui; Wang, Shuang; Sun, Zhi-Wei

    2015-08-01

    DNA vaccines are generally weak stimulators of the immune system. Fortunately, their efficacy can be improved using a viral replicon vector or by the addition of immunostimulatory CpG motifs, although the design of these engineered DNA vectors requires optimization. Our results clearly suggest that multiple copies of three types of CpG motifs or combinations of various types of CpG motifs cloned into a viral replicon vector backbone with strong immunostimulatory activities on human PBMC are efficient adjuvants for these DNA vaccines to modulate and enhance protective immunity against anthrax, although modifications with these different CpG forms in vivo elicited inconsistent immune response profiles. Modification with more copies of CpG motifs elicited more potent adjuvant effects leading to the generation of enhanced immunity, which indicated a CpG motif dose-dependent enhancement of antigen-specific immune responses. Notably, the enhanced and/or synchronous adjuvant effects were observed in modification with combinations of two different types of CpG motifs, which provides not only a contribution to the knowledge base on the adjuvant activities of CpG motifs combinations but also implications for the rational design of optimal DNA vaccines with combinations of CpG motifs as "built-in" adjuvants. We describe an efficient strategy to design and optimize DNA vaccines by the addition of combined immunostimulatory CpG motifs in a viral replicon DNA plasmid to produce strong immune responses, which indicates that the CpG-modified viral replicon DNA plasmid may be desirable for use as vector of DNA vaccines. PMID:25265876

  2. A DNA vaccine encoding VP22 of herpes simplex virus type I (HSV-1) and OprF confers enhanced protection from Pseudomonas aeruginosa in mice.

    PubMed

    Yu, Xian; Wang, Yan; Xia, Yifan; Zhang, Lijuan; Yang, Qin; Lei, Jun

    2016-08-17

    Pseudomonas aeruginosa antimicrobial resistance is a major therapeutic challenge. DNA vaccination is an attractive approach for antigen-specific immunotherapy against P. aeruginosa. We explored the feasibility of employing Herpes simplex virus type 1 tegument protein, VP22, as a molecular tool to enhance the immunogenicity of an OprF DNA vaccine against P. aeruginosa. Recombinant DNA vaccines, pVAX1-OprF, pVAX1-OprF-VP22 (encoding a n-OprF-VP22-c fusion protein) and pVAX1-VP22-OprF (encoding a n-VP22-OprF-c fusion protein) were constructed. The humoral and cellular immune responses and immune protective effects of these DNA vaccines in mice were evaluated. In this report, we showed that vaccination with pVAX1-OprF-VP22 induced higher levels of IgG titer, T cell proliferation rate. It also provided better immune protection against the P. aeruginosa challenge when compared to that induced by pVAX1-OprF or pVAX1-VP22-OprF DNA vaccines. Molecular mechanistic analyses indicated vaccination with pVAX1-OprF-VP22 triggered immune responses characterized by a preferential increase in antigen specific IgG2a and IFN-γ in mice, indicating Th1 polarization. We concluded that VP22 is a potent stimulatory molecular tool for DNA vaccination when fused to the carboxyl end of OprF gene. Our study provides a novel strategy for prevention and treatment of P. aeruginosa infection. PMID:27449680

  3. Codon optimization and woodchuck hepatitis virus posttranscriptional regulatory element enhance the immune responses of DNA vaccines against infectious bursal disease virus in chickens.

    PubMed

    Li, Kai; Gao, Li; Gao, Honglei; Qi, Xiaole; Gao, Yulong; Qin, Liting; Wang, Yongqiang; Wang, Xiaomei

    2013-08-01

    The present study was undertaken to evaluate the protective efficacy of DNA vaccines against infectious bursal disease virus (IBDV) in chickens and to determine whether codon optimization and the woodchuck hepatitis virus posttranscriptional regulatory element (WPRE) could improve the immunogenicity of the DNA vaccines. The VP2, VP243 and codon-optimized VP243 genes of IBDV were cloned into pCAGGS vector, and designated as pCAGVP2, pCAGVP243 and pCAGoptiVP243, respectively. Plasmids pCAGWVP243 and pCAGWoptiVP243 carrying the WPRE elements were also constructed as DNA vaccines. To evaluate vaccine efficacy, 2-week-old chickens were injected intramuscularly with the constructed plasmids twice at 2-week intervals and challenged with very virulent IBDV 2 weeks post-boost. Plasmid pCAGVP243 induced better immune responses than pCAGVP2. Chickens immunized with pCAGoptiVP243 and pCAGWVP243 had higher levels of antibody titers, lymphoproliferation responses and cytokine production compared with pCAGVP243. Furthermore, plasmid pCAGWoptiVP243 induced the highest levels of immune responses among the groups. After challenged, DNA vaccines pCAGVP2, pCAGVP243, pCAGoptiVP243, pCAGWVP243 and pCAGWoptiVP243 conferred protection for 33%, 60%, 80%, 87% and 100% of chickens, respectively, as evidenced by the absence of clinical signs, mortality, and bursal atrophy. These results indicate that codon optimization and WPRE could enhance the protective efficacy of DNA vaccines against IBDV and these two approaches could work together synergistically in a single DNA vaccine. PMID:23631937

  4. Biotechnology and DNA vaccines for aquatic animals

    USGS Publications Warehouse

    Kurath, G.

    2008-01-01

    Biotechnology has been used extensively in the development of vaccines for aquaculture. Modern molecular methods such as polymerase chain reaction (PCR), cloning and microarray analysis have facilitated antigen discovery, construction of novel candidate vaccines, and assessments of vaccine efficacy, mode of action, and host response. This review focuses on DNA vaccines for finfish to illustrate biotechnology applications in this field. Although DNA vaccines for fish rhabdoviruses continue to show the highest efficacy, DNA vaccines for several other viral and bacterial fish pathogens have now been proven to provide significant protection against pathogen challenge. Studies of the fish rhabdovirus DNA vaccines have elucidated factors that affect DNA vaccine efficacy as well as the nature of the fish innate and adaptive immune responses to DNA vaccines. As tools for managing aquatic animal disease emergencies, DNA vaccines have advantages in speed, flexibility, and safety, and one fish DNA vaccine has been licensed.

  5. Fusion of CTLA-4 with HPV16 E7 and E6 Enhanced the Potency of Therapeutic HPV DNA Vaccine

    PubMed Central

    Gan, Lili; Jia, Rong; Zhou, Lili; Guo, Jihua; Fan, Mingwen

    2014-01-01

    Preventive anti-HPV vaccines are effective against HPV infection but not against existing HPV-associated diseases, including cervical cancer and other malignant diseases. Therefore, the development of therapeutic vaccines is urgently needed. To improve anti-tumor effects of therapeutic vaccine, we fused cytotoxic T-lymphocyte antigen 4 (CTLA-4) with HPV16 E7 and E6 as a fusion therapeutic DNA vaccine (pCTLA4-E7E6). pCTLA4-E7E6 induced significantly higher anti-E7E6 specific antibodies and relatively stronger specific CTL responses than the nonfusion DNA vaccine pE7E6 in C57BL/6 mice bearing with TC-1 tumors. pCTLA4-E7E6 showed relatively stronger anti-tumor effects than pE7E6 in therapeutic immunization. These results suggest that fusing CTLA-4 with E7E6 is a useful strategy to develop therapeutic HPV DNA vaccines. In addition, fusing the C-terminal of E7 with the N-terminal of E6 impaired the functions of both E7 and E6. PMID:25265018

  6. A novel prototype device for electroporation-enhanced DNA vaccine delivery simultaneously to both skin and muscle.

    PubMed

    Lin, Feng; Shen, Xuefei; McCoy, Jay R; Mendoza, Janess M; Yan, Jian; Kemmerrer, Steve V; Khan, Amir S; Weiner, David B; Broderick, Kate E; Sardesai, Niranjan Y

    2011-09-01

    Electroporation (EP) of either muscle or skin has proven to be an efficient method for increasing DNA-based vaccine delivery and immunogenicity in small and large animals. Previous comparative studies in large animals suggest that intramuscular (i.m.) DNA EP delivery appears to favor cellular immunity, while intradermal (i.d.) EP delivery may favor humoral immunity. While current EP devices are primarily designed either for i.m. or i.d. delivery, we developed a novel prototype Dual-Depth Device (DDD) for EP-mediated simultaneous i.d. and i.m. delivery of DNA-based vaccines with an attempt to elicit superior antibody and cellular immune responses. We performed comparisons of DDD EP delivery with standard i.d. EP, standard i.m. EP, and combined delivery of i.d. and i.m. EP at separate sites, for the ability to induce antigen-specific immune responses. In a guinea pig model using a SynCon™ DNA vaccine encoding the influenza virus H5 hemaglutinin (H5HA), vaccination via DDD or combined delivery induced higher antibody titers than via either i.d. or i.m. delivery alone. In a mouse model using a DNA vaccine encoding the nucleoprotein (NP) of influenza H1N1, the resulting trend of antibody responses was similar to that detected in guinea pig study. Importantly, cellular immune responses in the DDD or combined delivery groups were significantly stronger than that in either i.d. or i.m. delivery groups. We conclude that EP-mediated DNA-based vaccine delivery to both skin and muscle is superior to delivery to either tissue alone for induction of antigen-specific antibody and cellular immunity. PMID:21199706

  7. Feline Leukemia Virus DNA Vaccine Efficacy Is Enhanced by Coadministration with Interleukin-12 (IL-12) and IL-18 Expression Vectors

    PubMed Central

    Hanlon, Linda; Argyle, David; Bain, Derek; Nicolson, Lesley; Dunham, Stephen; Golder, Matthew C.; McDonald, Michael; McGillivray, Christine; Jarrett, Oswald; Neil, James C.; Onions, David E.

    2001-01-01

    The expectation that cell-mediated immunity is important in the control of feline leukemia virus (FeLV) infection led us to test a DNA vaccine administered alone or with cytokines that favored the development of a Th1 immune response. The vaccine consisted of two plasmids, one expressing the gag/pol genes and the other expressing the env gene of FeLV-A/Glasgow-1. The genetic adjuvants were plasmids encoding the feline cytokines interleukin-12 (IL-12), IL-18, or gamma interferon (IFN-γ). Kittens were immunized by three intramuscular inoculations of the FeLV DNA vaccine alone or in combination with plasmids expressing IFN-γ, IL-12, or both IL-12 and IL-18. Control kittens were inoculated with empty plasmid. Following immunization, anti-FeLV antibodies were not detected in any kitten. Three weeks after the final immunization, the kittens were challenged by the intraperitoneal inoculation of FeLV-A/Glasgow-1 and were then monitored for a further 15 weeks for the presence of virus in plasma and, at the end of the trial, for latent virus in bone marrow. The vaccine consisting of FeLV DNA with the IL-12 and IL-18 genes conferred significant immunity, protecting completely against transient and persistent viremia, and in five of six kittens protecting against latent infection. None of the other vaccines provided significant protection. PMID:11507187

  8. Enhancement of HCV polytope DNA vaccine efficacy by fusion to an N-terminal fragment of heat shock protein gp96.

    PubMed

    Pishraft-Sabet, Leila; Kosinska, Anna D; Rafati, Sima; Bolhassani, Azam; Taheri, Tahereh; Memarnejadian, Arash; Alavian, Seyed-Moayed; Roggendorf, Michael; Samimi-Rad, Katayoun

    2015-01-01

    Induction of a strong hepatitis C virus (HCV)-specific immune response plays a key role in control and clearance of the virus. A polytope (PT) DNA vaccine containing B- and T-cell epitopes could be a promising vaccination strategy against HCV, but its efficacy needs to be improved. The N-terminal domain of heat shock protein gp96 (NT(gp96)) has been shown to be a potent adjuvant for enhancing immunity. We constructed a PT DNA vaccine encoding four HCV immunodominant cytotoxic T lymphocyte epitopes (two HLA-A2- and two H2-D(d)-specific motifs) from the Core, E2, NS3 and NS5B antigens in addition to a T-helper CD4+ epitope from NS3 and a B-cell epitope from E2. The NT(gp96) was fused to the C- or N-terminal end of the PT DNA (PT-NT(gp96) or NT(gp96)-PT), and their potency was compared. Cellular and humoral immune responses against the expressed peptides were evaluated in CB6F1 mice. Our results showed that immunization of mice with PT DNA vaccine fused to NT(gp96) induced significantly stronger T-cell and antibody responses than PT DNA alone. Furthermore, the adjuvant activity of NT(gp96) was more efficient in the induction of immune responses when fused to the C-terminal end of the HCV DNA polytope. In conclusion, the NT(gp96) improved the efficacy of the DNA vaccine, and this immunomodulatory effect was dependent on the position of the fusion. PMID:25348271

  9. Enhanced immunogenicity of microencapsulated multiepitope DNA vaccine encoding T and B cell epitopes of foot-and-mouth disease virus in mice.

    PubMed

    Wang, Fang; He, Xiao-Wen; Jiang, Lei; Ren, Ding; He, Ying; Li, De-An; Sun, Shu-Han

    2006-03-15

    The role of poly(D,L-lactic-co-glycolic acid, PLGA) microparticles on enhancing immune responses of multiepitope DNA vaccines was investigated in vitro and in vivo. pcDNA-SG encoding T and B cell epitopes of foot-and-mouth disease virus (FMDV) was encapsulated into PLGA microparticles. PLGA microparticles could protect themselves from nuclease degradation in vitro. PLGA-pcDNA-SG microparticles could be uptaken by cells and expressed His-tagged SG immunogen in vitro and in vivo. A prolonged expression and presentation of SG immunogen were observed by confocal laser scanning microscopy in the lymphocytes from the mice incubated with PLGA-pcDNA-SG microparticles, compared with the mice immunized with naked pcDNA-SG. PLGA-pcDNA-SG microparticles displayed a significant stronger immunogenicity than naked DNA vaccines with a higher titer of virus-specific antibody, elevated IFN-gamma production and enhanced lymphocyte proliferation. PLGA-DNA microparticle could elicit augmented humoral and cellular responses with reduced amounts and times of immunization. PMID:16414158

  10. MPG-based nanoparticle: An efficient delivery system for enhancing the potency of DNA vaccine expressing HPV16E7.

    PubMed

    Saleh, Tayebeh; Bolhassani, Azam; Shojaosadati, Seyed Abbas; Aghasadeghi, Mohammad Reza

    2015-06-22

    DNA vaccines against human papillomavirus (HPV) type 16 have not been successful in clinical trials, due to the lack of an appropriate delivery system. In this study, a peptide-based gene delivery system, MPG, which forms stable non-covalent nanoparticles with nucleic acids, was used for in vitro and in vivo delivery of HPV16 E7 DNA as a model antigen. The results demonstrated that at Nitrogen/Phosphate (N/P) ratio over 10:1, this peptide can effectively condense plasmid DNA into stable nanoparticles with an average size of 180-210nm and a positive surface charge. The transfection efficiency of MPG-based nanoparticles was shown to be comparable with Polyethyleneimine (PEI). The efficient protein expression detected by western blotting and flow cytometry supports the potential of MPG-based nanoparticles as a potent delivery system in DNA vaccine formulations. Immunization with MPG/E7DNA nanoparticles at an N/P ratio of 10:1 induced a stronger Th1 cellular immune response with a predominant interferon-γ (IFN-γ) profile than those induced by E7DNA alone in a murine tumor model. These findings suggest that MPG peptide as a novel gene delivery system could have promising applications in improving HPV therapeutic vaccines. PMID:26001433

  11. Pharmacokinetics and risk evaluation of DNA vaccine against Schistosoma japonicum.

    PubMed

    Liu, Hai-Feng; Li, Wei; Lu, Ming-Bo; Yu, Long-Jiang

    2013-01-01

    DNA plasmid immunization is a novel approach of preventive and therapeutic vaccine. More than 100 DNA vaccines have been on preclinical or clinical phase trials, and four kinds of DNA vaccines for livestock have been approved by USDA, CFIA, and APVMA. Schistosomiasis is a worldwide parasitic disease, and vaccine immunization is supposed to be a promising approach to control the health crisis. On the basis of former preclinical studies, we further focused on the pharmacokinetics and risk evaluation of DNA vaccine in vivo. In the present study, enhanced green fluorescent protein (EGFP) report gene was fused with Schistosoma japonicum 23 kDa transmembrane protein antigen gene (Sj23) and constructed into DNA vaccine pVIVO2-Sj23.EGFP. After intramuscularly injecting 100 μg of purified DNA vaccine plasmid to immunizate BALB/c mice, we studied the tissue distribution of DNA plasmid and expressed Sj23.EGFP antigen, the persistence time of elicited antibodies, and the risk of DNA vaccine transferred into intestinal microorganisms. The results showed that DNA vaccine plasmid could be distributed into all tissues of the body after injection; however, only few organs including the injected muscle were detected DNA vaccine at postimmunization until the 100 days by PCR technology; the detection of green fluorescence protein displayed that DNA vaccine could be expressed in almost every tissue and organs; the ELISA assay indicated the immune antibody against Sj23 could persist over 70 days; and the DNA vaccine transferring intestinal flora results was negative. The results indicated that the DNA vaccine has systemic protection and long-lasting effectivity and is safe to intestinal flora. PMID:22990210

  12. Polysaccharides from Dioscorea (山藥 Shān Yào) and Other Phytochemicals Enhance Antitumor Effects Induced by DNA Vaccine Against Melanoma

    PubMed Central

    Wei, Wen-Chi; Wang, Jeng-Hwan; Aravindaram, Kandan; Wang, Shu-Jane; Hsu, Chih-Chien; Li, Chin-Jin; Wen, Chih-Chun; Sheu, Jyh-Horng; Yang, Ning-Sun

    2014-01-01

    Adjuvants can be used to enhance the immunogenicity of antigens and improve the efficacy of vaccines. Potent adjuvant action is known to often correlate with the activation of the transcription factor, nuclear factor-κB (NF-κB). Specific plant polysaccharides and a variety of phytochemicals from foods and traditional medicinal herbs have been shown to modulate NF-κB activation. In the present study, selected plant polysaccharides and phytochemicals were evaluated for use as a DNA vaccine adjuvant in a murine melanoma model. We observed that a specific ethanol extract fraction (DsCE-I) from the tuber of a key Traditional Chinese Medicine plant, Dioscorea (山藥 Shān Yào), enhanced the protection against melanoma after immunization with a gene-based vaccine. A number of anti-inflammatory phytochemicals tested were able to partially diminish the inflammation-associated tumorigenesis elicited by LPS. Among the several phytochemical combinations investigated, the use of an adjuvant containing LPS in combination with emodin resulted in smaller tumors and higher survival rate in test mice than the use of other adjuvant treatments and the control sets in this DNA cancer vaccine model. A Dioscorea polysaccharide fraction (DsCE-I) and several specific phytochemicals warrant further exploration as useful adjuvants for anticancer vaccines. PMID:24872932

  13. Enhanced immunogenicity of CD4(+) t-cell responses and protective efficacy of a DNA-modified vaccinia virus Ankara prime-boost vaccination regimen for murine tuberculosis.

    PubMed

    McShane, H; Brookes, R; Gilbert, S C; Hill, A V

    2001-02-01

    DNA vaccines whose DNA encodes a variety of antigens from Mycobacterium tuberculosis have been evaluated for immunogenicity and protective efficacy. CD8(+) T-cell responses and protection achieved in other infectious disease models have been optimized by using a DNA immunization to prime the immune system and a recombinant virus encoding the same antigen(s) to boost the response. A DNA vaccine (D) and recombinant modified vaccinia virus Ankara (M) in which the DNA encodes early secreted antigenic target 6 and mycobacterial protein tuberculosis 63 synthesized, and each was found to generate specific gamma interferon (IFN-gamma)-secreting CD4(+) T cells. Enhanced CD4(+) IFN-gamma T-cell responses were produced by both D-M and M-D immunization regimens. Significantly higher levels of IFN-gamma were seen with a D-D-D-M immunization regimen. The most immunogenic regimens were assessed in a challenge study and found to produce protection equivalent to that produced by Mycobacterium bovis BCG. Thus, heterologous prime-boost regimens boost CD4(+) as well as CD8(+) T-cell responses, and the use of heterologous constructs encoding the same antigen(s) may improve the immunogenicity and protective efficacy of DNA vaccines against tuberculosis and other diseases. PMID:11159955

  14. DNA prime-protein boost based vaccination with a conserved region of leptospiral immunoglobulin-like A and B proteins enhances protection against leptospirosis

    PubMed Central

    Forster, Karine M; Hartwig, Daiane D; Oliveira, Thaís L; Bacelo, Kátia L; Schuch, Rodrigo; Amaral, Marta G; Dellagostin, Odir A

    2015-01-01

    Leptospirosis is a zoonotic disease caused by pathogenic spirochetes of theLeptospira genus. Vaccination with bacterins has severe limitations. Here, we evaluated the N-terminal region of the leptospiral immunoglobulin-like B protein (LigBrep) as a vaccine candidate against leptospirosis using immunisation strategies based on DNA prime-protein boost, DNA vaccine, and subunit vaccine. Upon challenge with a virulent strain ofLeptospira interrogans, the prime-boost and DNA vaccine approaches induced significant protection in hamsters, as well as a specific IgG antibody response and sterilising immunity. Although vaccination with recombinant fragment of LigBrep also produced a strong antibody response, it was not immunoprotective. These results highlight the potential of LigBrep as a candidate antigen for an effective vaccine against leptospirosis and emphasise the use of the DNA prime-protein boost as an important strategy for vaccine development. PMID:26676320

  15. DNA prime-protein boost based vaccination with a conserved region of leptospiral immunoglobulin-like A and B proteins enhances protection against leptospirosis.

    PubMed

    Forster, Karine M; Hartwig, Daiane D; Oliveira, Thaís L; Bacelo, Kátia L; Schuch, Rodrigo; Amaral, Marta G; Dellagostin, Odir A

    2015-12-01

    Leptospirosis is a zoonotic disease caused by pathogenic spirochetes of the Leptospira genus. Vaccination with bacterins has severe limitations. Here, we evaluated the N-terminal region of the leptospiral immunoglobulin-like B protein (LigBrep) as a vaccine candidate against leptospirosis using immunisation strategies based on DNA prime-protein boost, DNA vaccine, and subunit vaccine. Upon challenge with a virulent strain ofLeptospira interrogans, the prime-boost and DNA vaccine approaches induced significant protection in hamsters, as well as a specific IgG antibody response and sterilising immunity. Although vaccination with recombinant fragment of LigBrep also produced a strong antibody response, it was not immunoprotective. These results highlight the potential of LigBrep as a candidate antigen for an effective vaccine against leptospirosis and emphasise the use of the DNA prime-protein boost as an important strategy for vaccine development. PMID:26676320

  16. DNA Immunization for HIV Vaccine Development

    PubMed Central

    Chen, Yuxin; Wang, Shixia; Lu, Shan

    2014-01-01

    DNA vaccination has been studied in the last 20 years for HIV vaccine research. Significant experience has been accumulated in vector design, antigen optimization, delivery approaches and the use of DNA immunization as part of a prime-boost HIV vaccination strategy. Key historical data and future outlook are presented. With better understanding on the potential of DNA immunization and recent progress in HIV vaccine research, it is anticipated that DNA immunization will play a more significant role in the future of HIV vaccine development. PMID:26344472

  17. Harnessing DNA-induced immune responses for improving cancer vaccines

    PubMed Central

    Herrada, Andrés A.; Rojas-Colonelli, Nicole; González-Figueroa, Paula; Roco, Jonathan; Oyarce, César; Ligtenberg, Maarten A.; Lladser, Alvaro

    2012-01-01

    DNA vaccines have emerged as an attractive strategy to promote protective cellular and humoral immunity against the encoded antigen. DNA vaccines are easy to generate, inexpensive to produce and purify at large-scale, highly stable and safe. In addition, plasmids used for DNA vaccines act as powerful “danger signals” by stimulating several DNA-sensing innate immune receptors that promote the induction of protective adaptive immunity. The induction of tumor-specific immune responses represents a major challenge for DNA vaccines because most of tumor-associated antigens are normal non-mutated self-antigens. As a consequence, induction of potentially self-reactive T cell responses against such poorly immunogenic antigens is controlled by mechanisms of central and peripheral tolerance as well as tumor-induced immunosuppression. Although several DNA vaccines against cancer have reached clinical testing, disappointing results have been observed. Therefore, the development of new adjuvants that strongly stimulate the induction of antitumor T cell immunity and counteract immune-suppressive regulation is an attractive approach to enhance the potency of DNA vaccines and overcome tumor-associated tolerance. Understanding the DNA-sensing signaling pathways of innate immunity that mediate the induction of T cell responses elicited by DNA vaccines represents a unique opportunity to develop novel adjuvants that enhance vaccine potency. The advance of DNA adjuvants needs to be complemented with the development of potent delivery systems, in order to step toward successful clinical application. Here, we briefly discuss recent evidence showing how to harness DNA-induced immune response to improve the potency of cancer vaccines and counteract tumor-associated tolerance. PMID:23111166

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

    PubMed Central

    Williams, James A.

    2013-01-01

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

  19. Assembly and Assessment of DNA Scaffolded Vaccines.

    PubMed

    Liu, Xiaowei; Wang, Lili; Yan, Hao; Chang, Yung

    2016-01-01

    Vaccines play an important role in preventing many life-threatening infectious diseases. To meet the demand of vaccination for treating a wide range of diseases, rational vaccine design has been recognized as a desirable and necessary strategy for development of safe and effective vaccines. DNA nanostructures are advantageous in the design and construction of synthetic vaccines, owing to their robust self-assembly, programmability, and precision control in complex organization, as well as their intrinsic adjuvant activity. Here, we describe a modular assembly of DNA scaffolded vaccine complex, composing of a model antigen, streptavidin, and adjuvant, CpG oligonucleotide. The DNA-assembled vaccines were found to elicit strong antigen-specific antibody responses, but causing little or no adverse reactions. Conceivably, this vaccine platform can be further optimized for improved immunogenicity and extended to the construction of various subunit vaccines. PMID:27076307

  20. Co-Administration of Molecular Adjuvants Expressing NF-Kappa B Subunit p65/RelA or Type-1 Transactivator T-bet Enhance Antigen Specific DNA Vaccine-Induced Immunity

    PubMed Central

    Shedlock, Devon J.; Tingey, Colleen; Mahadevan, Lavanya; Hutnick, Natalie; Reuschel, Emma L.; Kudchodkar, Sagar; Flingai, Seleeke; Yan, Jenny; Kim, Joseph J.; Ugen, Kenneth E.; Weiner, David B.; Muthumani, Kar

    2014-01-01

    DNA vaccine-induced immunity can be enhanced by the co-delivery of synthetic gene-encoding molecular adjuvants. Many of these adjuvants have included cytokines, chemokines or co-stimulatory molecules that have been demonstrated to enhance vaccine-induced immunity by increasing the magnitude or type of immune responses and/or protective efficacy. In this way, through the use of adjuvants, immune responses can be highly customizable and functionally tailored for optimal efficacy against pathogen specific (i.e., infectious agent) or non-pathogen (i.e., cancer) antigens. In the novel study presented here, we examined the use of cellular transcription factors as molecular adjuvants. Specifically the co-delivery of (a) RelA, a subunit of the NF-κB transcription complex or (b) T-bet, a Th1-specific T box transcription factor, along with a prototypical DNA vaccine expressing HIV-1 proteins was evaluated. As well, all of the vaccines and adjuvants were administered to mice using in vivo electroporation (EP), a technology demonstrated to dramatically increase plasmid DNA transfection and subsequent transgene expression with concomitant enhancement of vaccine induced immune responses. As such, this study demonstrated that co-delivery of either adjuvant resulted in enhanced T and B cell responses, specifically characterized by increased T cell numbers, IFN-γ production, as well as enhanced antibody responses. This study demonstrates the use of cellular transcription factors as adjuvants for enhancing DNA vaccine-induced immunity. PMID:26344618

  1. Co-Administration of Molecular Adjuvants Expressing NF-Kappa B Subunit p65/RelA or Type-1 Transactivator T-bet Enhance Antigen Specific DNA Vaccine-Induced Immunity.

    PubMed

    Shedlock, Devon J; Tingey, Colleen; Mahadevan, Lavanya; Hutnick, Natalie; Reuschel, Emma L; Kudchodkar, Sagar; Flingai, Seleeke; Yan, Jenny; Kim, Joseph J; Ugen, Kenneth E; Weiner, David B; Muthumani, Kar

    2014-01-01

    DNA vaccine-induced immunity can be enhanced by the co-delivery of synthetic gene-encoding molecular adjuvants. Many of these adjuvants have included cytokines, chemokines or co-stimulatory molecules that have been demonstrated to enhance vaccine-induced immunity by increasing the magnitude or type of immune responses and/or protective efficacy. In this way, through the use of adjuvants, immune responses can be highly customizable and functionally tailored for optimal efficacy against pathogen specific (i.e., infectious agent) or non-pathogen (i.e., cancer) antigens. In the novel study presented here, we examined the use of cellular transcription factors as molecular adjuvants. Specifically the co-delivery of (a) RelA, a subunit of the NF-κB transcription complex or (b) T-bet, a Th1-specific T box transcription factor, along with a prototypical DNA vaccine expressing HIV-1 proteins was evaluated. As well, all of the vaccines and adjuvants were administered to mice using in vivo electroporation (EP), a technology demonstrated to dramatically increase plasmid DNA transfection and subsequent transgene expression with concomitant enhancement of vaccine induced immune responses. As such, this study demonstrated that co-delivery of either adjuvant resulted in enhanced T and B cell responses, specifically characterized by increased T cell numbers, IFN-γ production, as well as enhanced antibody responses. This study demonstrates the use of cellular transcription factors as adjuvants for enhancing DNA vaccine-induced immunity. PMID:26344618

  2. [DNA--the future in vaccine technology?].

    PubMed

    Kjeken, Rune; Bogen, Bjarne; Mathiesen, Iacob

    2006-11-16

    DNA vaccines represent a new and promising technology that uses DNA to encode the antigen(s) of interest, instead of inoculating with attenuated or inactivated microbes or isolated antigens. Antigen is produced within the transfected cells minaicking a real life viral infection. This vaccine modality has been shown to elicit strong cellular immune responses and is promising for treating diseases where traditional vaccine approaches have failed. In spite of promising results in small animal models, DNA vaccines have so far proven less potent in human clinical trials. In this review we provide a general overview on the mechanisms of action for DNA vaccines, discuss potential benefits of traditional vaccine approaches and review current strategies for improving the immunogenicity of DNA vaccines to enable the successful transfer of the technology can be successfully transferred from mice to men. PMID:17117196

  3. Novel approaches to tuberculosis prevention: DNA vaccines.

    PubMed

    Rivas-Santiago, Bruno; Cervantes-Villagrana, Alberto R

    2014-03-01

    It is estimated that there are approximately eight million new cases of active tuberculosis (TB) worldwide annually. There is only 1 vaccine available for prevention: bacillus Calmette-Guérin (BCG). This has variable efficacy and is only protective for certain extrapulmonary TB cases in children, therefore new strategies for the creation of novel vaccines have emerged. One of the promising approaches is the DNA vaccine, used as a direct vaccination or as a prime-boost vaccine. This review describes the experimental data obtained during the design of DNA vaccines for TB. PMID:24450840

  4. Mucosal immunization with high-mobility group box 1 in chitosan enhances DNA vaccine-induced protection against coxsackievirus B3-induced myocarditis.

    PubMed

    Wang, Maowei; Yue, Yan; Dong, Chunsheng; Li, Xiaoyun; Xu, Wei; Xiong, Sidong

    2013-11-01

    Coxsackievirus B3 (CVB3), a small single-stranded RNA virus, belongs to the Picornaviridae family. Its infection is the most common cause of myocarditis, with no vaccine available. Gastrointestinal mucosa is the major entry port for CVB3; therefore, the induction of local immunity in mucosal tissues may help control initial viral infections and alleviate subsequent myocardial injury. Here we evaluated the ability of high-mobility group box 1 (HMGB1) encapsulated in chitosan particles to enhance the mucosal immune responses induced by the CVB3-specific mucosal DNA vaccine chitosan-pVP1. Mice were intranasally coimmunized with 4 doses of chitosan-pHMGB1 and chitosan-pVP1 plasmids, at 2-week intervals, and were challenged with CVB3 4 weeks after the last immunization. Compared with chitosan-pVP1 immunization alone, coimmunization with chitosan-pHMGB1 significantly (P < 0.05) enhanced CVB3-specific fecal secretory IgA levels and promoted mucosal T cell immune responses. In accordance, reduced severity of myocarditis was observed in coimmunized mice, as evidenced by significantly (P < 0.05) reduced viral loads, decreased myocardial injury, and increased survival rates. Flow cytometric analysis indicated that HMGB1 enhanced dendritic cell (DC) recruitment to mesenteric lymph nodes and promoted DC maturation, which might partly account for its mucosal adjuvant effect. This strategy may represent a promising approach to candidate vaccines against CVB3-induced myocarditis. PMID:24027262

  5. Enhancement by ampicillin of antibody responses induced by a protein antigen and a DNA vaccine carried by live-attenuated Salmonella enterica serovar Typhi.

    PubMed

    Woo, P C; Tsoi, H W; Leung, H C; Wong, L P; Wong, S S; Chan, E; Yuen, K Y

    2000-07-01

    Live-attenuated Salmonella species are effective carriers of microbial antigens and DNA vaccines. In a mouse model, the immunoglobulin M (IgM) and total antibody levels directed toward the lipopolysaccharide of Salmonella enterica serovar Typhi were significantly enhanced at day 21 after oral immunization with live-attenuated serovar Typhi (strain Ty21a) when ampicillin was concomitantly administered (P < 0.05 and P < 0.005, respectively). The heat-killed Ty21a-stimulated lymphocyte proliferation indices for the ampicillin group at day 21 were significantly higher than those for the normal saline (NS) group (P < 0.005, P < 0.001, and P < 0.01) for all three doses of antigen (10(4), 10(5), and 10(6) heat-killed Ty21a per well, respectively). The 50% lethal doses for mice from the ampicillin and NS groups immunized with Ty21a with pBR322 after wild-type serovar Typhi challenge on day 24 were 3.4 x 10(7) and 5.0 x 10(6) CFU, respectively. The fecal bacterial counts for the ampicillin group at days 1, 3, and 5 were significantly lower than those for the NS group (P < 0.01, P < 0.01, and P < 0.05, respectively), and there was a trend toward recovery of Ty21a in a larger number of mice from the ampicillin group than from the NS group. Furthermore, the IgG2a levels directed toward tetanus toxoid were significantly enhanced at days 7 and 21 after oral immunization with Ty21a that carried the fragment c of tetanus toxoid when ampicillin was concomitantly administered (P < 0.05 and P < 0.005, respectively), and the IgM and total hepatitis B surface antibody levels were significantly enhanced at days 7 (P < 0.005 and P < 0.05, respectively) and 21 (P < 0.01 and P < 0.05, respectively) after oral immunization with Ty21a that carried the DNA vaccine that encodes hepatitis B surface antigen when ampicillin was concomitantly administered. The present observation may improve the efficacy of the protein antigens and DNA vaccines carried in live-attenuated bacteria, and further

  6. Rabies DNA vaccines for protection and therapeutic treatment.

    PubMed

    Lodmell, D L

    1999-02-01

    Rabies is a successful zoonotic disease that has persisted over time, achieving worldwide distribution in a variety of species. Annually, in developing countries with limited access to high-quality antirabies biologics, approximately 50,000 individuals and millions of animals die of rabies. Many of these countries continue to use vaccines produced in sheep, goat or suckling mouse brain, with ultraviolet light or phenol inactivation of the virus. Although there are several efficacious rabies vaccines derived from cultured cells, such as the human diploid cell vaccine, they are costly to produce and prohibitively expensive for developing countries. DNA vaccines offer a new and powerful approach for the generation of needed vaccines. They are stable, inexpensive to produce, easy to construct and induce a full spectrum of long-lasting humoral and cellular immune responses. This review concerns the present state of rabies DNA vaccines, and addresses the technology that may enhance their therapeutic efficacy. PMID:15992067

  7. DNA vaccines and their applications in veterinary practice: current perspectives.

    PubMed

    Dhama, K; Mahendran, Mahesh; Gupta, P K; Rai, A

    2008-06-01

    Inoculation of plasmid DNA, encoding an immunogenic protein gene of an infectious agent, stands out as a novel approach for developing new generation vaccines for prevention of infectious diseases of animals. The potential of DNA vaccines to act in presence of maternal antibodies, its stability and cost effectiveness and the non-requirement of cold chain have heightened the prospects. Even though great strides have been made in nucleic acid vaccination, still there are many areas that need further research for its wholesome practical implementation. Major areas of concern are vaccine delivery, designing of suitable vectors and cytotoxic T cell responses. Also, the induction of immune responses by DNA vaccines is inconclusive due to the lack of knowledge regarding the concentration of the protein expressed in vivo. Alternative delivery systems having higher transfection efficiency and the use of cytokines, as immunomodulators, needs to be further explored. Recently, efforts are being made to modulate and prolong the active life of dendritic cells, in order to make antigen presentation a more efficacious one. For combating diseases like acquired immunodeficiency syndrome (AIDS), influenza, malaria and tuberculosis in humans; and foot and mouth disease, Aujesky's disease, swine fever, rabies, canine distemper and brucellosis in animals, DNA vaccine clinical trials are underway. This review highlights the salient features of DNA vaccines, and measures to enhance their efficacy so as to devise an effective and novel vaccination strategy against animal diseases. PMID:18425596

  8. SCIB2, an antibody DNA vaccine encoding NY-ESO-1 epitopes, induces potent antitumor immunity which is further enhanced by checkpoint blockade

    PubMed Central

    Xue, Wei; Metheringham, Rachael L.; Brentville, Victoria A.; Gunn, Barbara; Symonds, Peter; Yagita, Hideo; Ramage, Judith M.; Durrant, Lindy G.

    2016-01-01

    ABSTRACT Checkpoint blockade has demonstrated promising antitumor responses in approximately 10–40% of patients. However, the majority of patients do not make a productive immune response to their tumors and do not respond to checkpoint blockade. These patients may benefit from an effective vaccine that stimulates high-avidity T cell responses in combination with checkpoint blockade. We have previously shown that incorporating TRP-2 and gp100 epitopes into the CDR regions of a human IgG1 DNA (ImmunoBody®: IB) results in significant tumor regression both in animal models and patients. This vaccination strategy is superior to others as it targets antigen to antigen-presenting cells and stimulates high-avidity T cell responses. To broaden the application of this vaccination strategy, 16 NY-ESO-1 epitopes, covering over 80% of HLA phenotypes, were incorporated into the IB (SCIB2). They produced higher frequency and avidity T cell responses than peptide vaccination. These T cells were of sufficient avidity to kill NY-ESO-1-expressing tumor cells, and in vivo controlled the growth of established B16-NY-ESO-1 tumors, resulting in long-term survival (35%). When SCIB2 was given in combination with Treg depletion, CTLA-4 blockade or PD-1 blockade, long-term survival from established tumors was significantly enhanced to 56, 67 and 100%, respectively. Translating these responses into the clinic by using a combination of SCIB2 vaccination and checkpoint blockade can only further improve clinical responses. PMID:27471648

  9. A fusion DNA vaccine encoding middle version of HBV envelope protein fused to interleukin-21 did not enhance HBV-specific immune response in mice.

    PubMed

    Zhang, Ye; Su, Wen-Jing; Wang, Jue; Bai, Xue-Fan; Huang, Chang-Xing; Lian, Jian-Qi

    2014-11-01

    DNA vaccination can generate both humoral and cellular immunity, resulting in potential prophylactic and therapeutic vaccines in variety of conditions, including hepatitis B virus (HBV) infection. Fusion of cytokine gene is one of the ways to increase the immunogenicity of DNA vaccine. Interleukin (IL)-21 has been demonstrated to play an immunomodulatory role in HBV infection. Thus, we aimed to investigate the ability of IL-21 in the regulation of middle version of HBV envelop protein (MS) DNA vaccine. Fusion plasmid encoding IL-21 linked with MS was constructed. Normal and HBV transgenic mice were immunized by plasmid. pcDNA-IL-21/S2S induced a comparable level of anti-HBs antibody and HBsAg-specific CD8+ T-cell response with pcDNA-S2S. Furthermore, the level of circulating HBsAg was decreased by induction of anti-HBs antibody and HBsAg-specific CD8+ T-cell response to both pcDNA-IL-21/S2S and pcDNA-S2S vaccination in HBV transgenic mice. Thus, immunization with DNA vaccine encoding HBV MS protein induced both T- and B-cell response by targeting the specific antigen. Furthermore, it was also revealed that MS DNA vaccination could break immune tolerance in HBV transgenic mice. But IL-21 did not strengthen immune response induced by HBV DNA immunization. Our study suggested that MS-expressing plasmid may be useful for both preventive and therapeutic methods in HBV infection. However, IL-21 does not improve the immunogenicity and efficacy of MS DNA vaccination, and thus may not be used as a therapeutic marker for chronic hepatitis B. PMID:25211639

  10. A cationic liposome-DNA complexes adjuvant (JVRS-100) enhances the immunogenicity and cross-protective efficacy of pre-pandemic influenza A (H5N1) vaccine in ferrets.

    PubMed

    Liu, Feng; Sun, Xiangjie; Fairman, Jeffery; Lewis, David B; Katz, Jacqueline M; Levine, Min; Tumpey, Terrence M; Lu, Xiuhua

    2016-05-01

    Influenza A (H5N1) viruses continue to pose a public health threat. As inactivated H5N1 vaccines are poorly immunogenic, adjuvants are needed to improve the immunogenicity of H5N1 vaccine in humans. Here, we investigated the immunogenicity and cross-protective efficacy in ferrets of a clade 2.2-derived vaccine with addition of JVRS-100, an adjuvant consisting of cationic liposome-DNA complexes (CLDC). After the first vaccination, significantly higher levels of hemagglutination-inhibition (HAI) and neutralizing antibody titers were detected in ferrets immunized with adjuvanted vaccine compared to unadjuvanted vaccine. Following a second dose of adjuvanted vaccine, HAI antibody titers of ≥ 40 were detected against viruses from multiple H5N1 clades. HAI antibodies against newly isolated H5N2 and H5N8 viruses were also augmented by JVRS-100. Ferrets were challenged with a heterologous H5N1 virus. All ferrets that received two doses of adjuvanted vaccine exhibited mild illness, significantly reduced nasal wash virus titers and protection from lethal challenge. In contrast, ferrets that received unadjuvanted vaccine showed greater weight loss, high viral titers and 3 of 6 animals succumbed to the lethal challenge. Our results indicate that the addition of JVRS-100 to H5N1 vaccine enhanced immunogenicity and cross-protection against lethal H5N1 virus disease in ferrets. JVRS-100 warrants further investigation as a potential adjuvant for influenza vaccines. PMID:26967975

  11. Effect of sperm DNA vaccine on fertility of female mice.

    PubMed

    Naz, Rajesh K

    2006-07-01

    Our laboratory has identified a sperm-specific dodecamer peptide sequence, designated as YLP(12), vaccination with which causes a long-term reversible immunocontraceptive effect in female mice. In the present study, the effects of YLP(12) DNA vaccine were examined. YLP(12) 36 bp cDNA was cloned into pVAX1 vector to prepare the DNA vaccine. Two additional vaccine constructs were made by in frame cloning of one and two CpG repeats in the YLP(12)-cDNA vaccine. Five groups of female mice were immunized intradermally by using gene gun with YLP(12)-cDNA, YLP(12)-cDNA-CpG, YLP(12)-cDNA-CpG-CpG, YLP(12)-cDNA mixed with exogenous synthetic CpG oligodeoxynucleotide (ODN), or vector DNA alone, respectively. Vaccination with all three constructs and the YLP(12) vaccine mixed with exogenous ODN raised antibody response both in the sera as well as locally in the vaginal tract. There was no antibody response in the mice injected with the vector alone. In sera, the highest titers were obtained for the IgG class for all constructs and formulation followed by IgA class. In vaginal washings the highest titers were obtained for the IgA class followed by IgG class. Within the IgG class, the titers for the IgG2a subclass were significantly greater than the IgG1 subclass. Immunization with all constructs and formulation caused a significant (P < 0.05 to <0.001) reduction (20-43%) in fertility of female mice. The highest reductions were seen in mice immunized with YLP(12)-cDNA-CpG-CpG (two repeats) (43% reduction) and with the YLP(12) vaccine administered with exogenous CpG ODN (42% reduction). T lymphocytes obtained from DNA-vaccinated mice showed clearly distinguished comparative RT-PCR analysis of cytokine mRNA expression for Th1 and Th2 immune responses compared to T lymphocytes obtained from control animals injected with vector DNA. Expression of both Th1 cytokines (IL-2 and IFN-gamma) and Th2 cytokines (IL-4 and IL-10) was enhanced after DNA vaccination as compared to controls, with

  12. Enhancement of immunogenicity and efficacy of a plasmid DNA rabies vaccine by nanoformulation with a fourth-generation amine-terminated poly(ether imine) dendrimer

    PubMed Central

    Ullas, Padinjaremattathil Thankappan; Madhusudana, Shampur Narayan; Desai, Anita; Sagar, Bhadravathi Kenchappa Chandrasekhar; Jayamurugan, Govindasamy; Rajesh, Yamajala Bhaskara Rama Durga; Jayaraman, Narayanaswami

    2014-01-01

    Purpose Delayed onset of, and low magnitude of, protective immune responses are major drawbacks limiting the practical utility of plasmid vaccination against rabies. In this study we evaluated whether nanoformulation with the novel poly(ether imine) (PETIM) dendrimer can enhance the immunogenicity and efficacy of a plasmid-based rabies vaccine. Materials and methods A plasmid vaccine construct (pIRES-Rgp) was prepared by cloning the full-length rabies virus glycoprotein gene into pIRES vector. Drawing upon the results of our previous study, a dendriplex (dendrimer-DNA complex) of pIRES-Rgp was made with PETIM dendrimer (10:1 w/w, PETIM:pIRES-Rgp). In vitro transfection was done on baby hamster kidney (BHK)-21 cells to evaluate expression of glycoprotein gene from pIRES-Rgp and PETIM-pIRES-Rgp. Subsequently, groups of Swiss albino mice were immunized intramuscularly with pIRES-Rgp or PETIM-pIRES-Rgp. A commercially available cell culture rabies vaccine was included for comparison. Rabies virus neutralizing antibody (RVNA) titers in the immune sera were evaluated on days 14, 28, and 90 by rapid fluorescent focus inhibition test. Finally, an intracerebral challenge study using a challenge virus standard strain of rabies virus was done to evaluate the protective efficacy of the formulations. Results Protective levels of RVNA titer (≥0.5 IU/mL) were observed by day 14 in animals immunized with pIRES-Rgp and its dendriplex. Notably, PETIM-pIRES-Rgp produced 4.5-fold higher RVNA titers compared to pIRES-Rgp at this time point. All mice immunized with the PETIM-pIRES-Rgp survived the intracerebral rabies virus challenge, compared with 60% in the group which received pIRES-Rgp. Conclusion Our results suggest that nanoformulation with PETIM dendrimer can produce an earlier onset of a high-titered protective antibody response to a plasmid-based rabies vaccine. PETIM dendriplexing appears to be an efficacious nonviral delivery strategy to enhance genetic vaccination. PMID

  13. Combination of treatment with death receptor 5-specific antibody with therapeutic HPV DNA vaccination generates enhanced therapeutic anti-tumor effects.

    PubMed

    Tseng, Chih Wen; Monie, Archana; Trimble, Cornelia; Alvarez, Ronald D; Huh, Warner K; Buchsbaum, Donald J; Straughn, J Michael; Wang, Mei-Cheng; Yagita, Hideo; Hung, Chien-Fu; Wu, T-C

    2008-08-12

    There is currently a vital need for the development of novel therapeutic strategies for the control of advanced stage cancers. Antigen-specific immunotherapy and the employment of antibodies against the death receptor 5 (DR5) have emerged as two potentially promising strategies for cancer treatment. In the current study, we hypothesize that the combination of treatment with the anti-DR5 monoclonal antibody, MD5-1 with a DNA vaccine encoding calreticulin (CRT) linked to human papillomavirus type 16 (HPV-16) E7 antigen (CRT/E7(detox)) administered via gene gun would lead to further enhancement of E7-specific immune responses as well as anti-tumor effects. Our results indicated that mice bearing the E7-expressing tumor, TC-1 treated with MD5-1 monoclonal antibody followed by CRT/E7(detox) DNA vaccination generated the most potent therapeutic anti-tumor effects as well as highest levels of E7-specific CD8+ T cells among all the groups tested. In addition, treatment with MD5-1 monoclonal antibody was capable of rendering the TC-1 tumor cells more susceptible to lysis by E7-specific cytotoxic T lymphocytes. Our findings serve as an important foundation for future clinical translation. PMID:18598733

  14. Targeting DNA vaccines to myeloid cells using a small peptide.

    PubMed

    Ye, Chunting; Choi, Jang Gi; Abraham, Sojan; Shankar, Premlata; Manjunath, N

    2015-01-01

    Targeting DNA vaccines to dendritic cells (DCs) greatly enhances immunity. Although several approaches have been used to target protein Ags to DCs, currently there is no method that targets DNA vaccines directly to DCs. Here, we show that a small peptide derived from the rabies virus glycoprotein fused to protamine residues (RVG-P) can target DNA to myeloid cells, including DCs, which results in enhanced humoral and T-cell responses. DCs targeted with a DNA vaccine encoding the immunodominant vaccinia B8R gene via RVG-P were able to restimulate vaccinia-specific memory T cells in vitro. Importantly, a single i.v. injection of B8R gene bound to RVG-P was able to prime a vaccinia-specific T-cell response that was able to rapidly clear a subsequent vaccinia challenge in mice. Moreover, delivery of DNA in DCs was enough to induce DC maturation and efficient Ag presentation without the need for adjuvants. Finally, immunization of mice with a DNA-vaccine encoding West Nile virus (WNV) prM and E proteins via RVG-P elicited high titers of WNV-neutralizing Abs that protected mice from lethal WNV challenge. Thus, RVG-P provides a reagent to target DNA vaccines to myeloid cells and elicit robust T-cell and humoral immune responses. PMID:25270431

  15. Electroporation enhances immune responses and protection induced by a bovine viral diarrhea virus DNA vaccine in newborn calves with maternal antibodies.

    PubMed

    van Drunen Littel-van den Hurk, Sylvia; Lawman, Zoe; Wilson, Don; Luxembourg, Alain; Ellefsen, Barry; van den Hurk, Jan V; Hannaman, Drew

    2010-09-01

    Bovine viral diarrhea virus (BVDV) is one of the major pathogens in cattle. In this study, newborn calves with maternal antibodies were vaccinated with a BVDV DNA vaccine, either by conventional intramuscular (IM) injection or with the TriGrid™ Delivery System for IM delivery (TDS-IM). The calves vaccinated with the TDS-IM developed more rapidly and effectively BVDV-specific humoral and cell-mediated immune responses in the presence of maternal antibodies. Overall, the immune responses induced by delivery with the TDS-IM remained stronger than those elicited by conventional IM injection of the BVDV DNA vaccine. Accordingly, electroporation-mediated delivery of the BVDV DNA vaccine resulted in close to complete protection from clinical signs of disease, while conventional IM administration did not fully prevent morbidity and mortality following challenge with BVDV-2. These results demonstrate the TDS-IM to be effective as a delivery system for a BVDV DNA vaccine in newborn calves in the presence of maternal antibodies, which supports the potential of electroporation as a delivery method for prophylactic DNA vaccines. PMID:20670907

  16. Tetravalent DNA vaccine product as a vaccine candidate against dengue.

    PubMed

    Porter, Kevin R; Teneza-Mora, Nimfa; Raviprakash, Kanakatte

    2014-01-01

    Dengue is the most important arbovirus worldwide and is the virus that causes dengue fever and the more severe dengue hemorrhagic fever. There are four serotypes of dengue with each possessing the ability to cause disease. Developing a preventive vaccine is the most efficient and effective way to prevent these diseases, and because immunity to one serotype does not protect against the other serotypes, a vaccine must provide tetravalent protection. We used DNA immunization as a platform to develop a tetravalent vaccine. In this chapter, we describe the laboratory, regulatory, and clinical methodology for evaluating a candidate tetravalent vaccine in a Phase 1 clinical trial. PMID:24715294

  17. Chimeric vapA/groEL2 DNA vaccines enhance clearance of Rhodococcus equi in aerosol challenged C3H/He mice.

    PubMed

    Phumoonna, Tongted; Barton, Mary D; Vanniasinkam, Thiru; Heuzenroeder, Michael W

    2008-05-12

    Rhodococcus equi remains a significant bacterial pathogen, causing severe pyogranulomatous pneumonia in foals aged 1-3 months. There is no effective vaccine currently available for the prevention of R. equi pneumonia. DNA vaccines are known to offer specific advantages over conventional vaccines. The aim of this study was to demonstrate efficacy of our recombinant DNA vaccine candidates, namely pcDNA3-Re1, pcDNA3-Re3 and pcDNA3-Re5 by combining a heat shock protein GroEL2 to a virulence-associated protein A (VapA) from R. equi to protect C3H/He mice against the R. equi infection. VapA was shown to be strongly recognised by sera from pneumonic foals. All vaccines elicited at least a doubling of the IgG2a/IgG1 ratio in comparison to the controls, indicating a bias to the Th1 response, which is postulated to be crucial for bacterial clearance and protective immunity against intracellular pathogens including R. equi. In addition, the immunised mice showed a significant reduction in R. equi in their lungs at 7 days after the aerosol challenge in comparison to PBS treated mice. However, examination of lung pathology 14 days after the challenge showed no gross differences in pathological changes between the unvaccinated and vaccinated animals. The lack of significant pathological changes suggests that the precise level of protection against R. equi pneumonia in the murine model of infection may not represent a true effectiveness of the potential vaccine candidates, indicating the mouse may not be the ideal non-equine model for vaccine studies and (or) the incomplete immunogenic antigen of vapA-based DNA vaccine constructs that mount an inadequate cell-mediated immune response against the R. equi infection. PMID:18423949

  18. Electroporation delivery of DNA vaccines: prospects for success.

    PubMed

    Sardesai, Niranjan Y; Weiner, David B

    2011-06-01

    A number of noteworthy technology advances in DNA vaccines research and development over the past few years have led to the resurgence of this field as a viable vaccine modality. Notably, these include--optimization of DNA constructs; development of new DNA manufacturing processes and formulations; augmentation of immune responses with novel encoded molecular adjuvants; and the improvement in new in vivo delivery strategies including electroporation (EP). Of these, EP mediated delivery has generated considerable enthusiasm and appears to have had a great impact in vaccine immunogenicity and efficacy by increasing antigen delivery upto a 1000 fold over naked DNA delivery alone. This increased delivery has resulted in an improved in vivo immune response magnitude as well as response rates relative to DNA delivery by direct injection alone. Indeed the immune responses and protection from pathogen challenge observed following DNA administration via EP in many cases are comparable or superior to other well studied vaccine platforms including viral vectors and live/attenuated/inactivated virus vaccines. Significantly, the early promise of EP delivery shown in numerous pre-clinical animal models of many different infectious diseases and cancer are now translating into equally enhanced immune responses in human clinical trials making the prospects for this vaccine approach to impact diverse disease targets tangible. PMID:21530212

  19. Vaccine development using recombinant DNA technology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vaccines induce an immune response in the host that subsequently recognizes infectious agents and helps fight off the disease; vaccines must do this without causing the disease. This paper reviews the development of recombinant DNA technologies as a means of providing new ways for attenuating diseas...

  20. Pilot Study on the Use of DNA Priming Immunization to Enhance Y. pestis LcrV-Specific B Cell Responses Elicited by a Recombinant LcrV Protein Vaccine

    PubMed Central

    Li, Wei; Wang, Shixia; Lu, Shan

    2013-01-01

    Recent studies indicate that DNA immunization is powerful in eliciting antigen-specific antibody responses in both animal and human studies. However, there is limited information on the mechanism of this effect. In particular, it is not known whether DNA immunization can also enhance the development of antigen-specific B cell development. In this report, a pilot study was conducted using plague LcrV immunogen as a model system to determine whether DNA immunization is able to enhance LcrV-specific B cell development in mice. Plague is an acute and often fatal infectious disease caused by Yersinia pestis (Y. pestis). Humoral immune responses provide critical protective immunity against plague. Previously, we demonstrated that a DNA vaccine expressing LcrV antigen can protect mice from lethal mucosal challenge. In the current study, we further evaluated whether the use of a DNA priming immunization is able to enhance the immunogenicity of a recombinant LcrV protein vaccine, and in particular, the development of LcrV-specific B cells. Our data indicate that DNA immunization was able to elicit high-level LcrV antibody responses when used alone or as part of a prime-boost immunization approach. Most significantly, DNA immunization was also able to increase the levels of LcrV-specific B cell development. The finding that DNA immunization can enhance antigen-specific B cell responses is highly significant and will help guide similar studies in other model antigen systems. PMID:26344467

  1. Co-administration of plasmid expressing IL-12 with 14-kDa Schistosoma mansoni fatty acid-binding protein cDNA alters immune response profiles and fails to enhance protection induced by Sm14 DNA vaccine alone.

    PubMed

    Fonseca, Cristina T; Pacífico, Lucila G G; Barsante, Michele M; Rassi, Tatiana; Cassali, Geovanni D; Oliveira, Sérgio C

    2006-08-01

    Schistosomiasis is an endemic disease that affects 200 million people worldwide. DNA-based vaccine is a promising strategy to induce protective immunity against schistosomiasis, since both humoral and cellular immune responses are involved in parasite elimination. In this study, we evaluated the ability of Sm14 cDNA alone or in association with a plasmid expressing murine interleukin (IL)-12 to induce protection against challenge infection. Mice were immunized with four doses of the DNA vaccine and the levels of protection were determined by worm burden recovery after challenge infection. Specific antibody production to rSm14 was determined by ELISA, and cytokine production was measured in splenocyte culture supernatants stimulated with rSm14 and in bronchoalveolar lavage of vaccinated mice after challenge infection. DNA immunization with pCI/Sm14 alone induced 40.5% of worm reduction. However, the use of pCI/IL-12 as adjuvant to pCI/Sm14 immunization failed to enhance protection against challenge infection. Protection induced by pCI/Sm14 immunization correlates with specific IgG antibody production against Sm14, Th1 type of immune response with high levels of interferon (IFN)-gamma and low levels of IL-4 in splenocyte culture supernatants and in bronchoalveolar lavage after challenge infection. IL-12 co-administration with pCI/Sm14 induced a significant production of nitric oxide in splenocyte culture supernatants and also lymphocyte suppression, with reduced percentage of T cells producing IFN-gamma and tumor necrosis factor-alpha. PMID:16914349

  2. DNA vaccines, electroporation and their applications in cancer treatment

    PubMed Central

    Lee, Si-Hyeong; Danishmalik, Sayyed Nilofar; Sin, Jeong-Im

    2015-01-01

    Numerous animal studies and recent clinical studies have shown that electroporation-delivered DNA vaccines can elicit robust Ag-specific CTL responses and reduce disease severity. However, cancer antigens are generally poorly immunogenic, requiring special conditions for immune response induction. To date, many different approaches have been used to elicit Ag-specific CTL and anti-neoplastic responses to DNA vaccines against cancer. In vivo electroporation is one example, whereas others include DNA manipulation, xenogeneic antigen use, immune stimulatory molecule and immune response regulator application, DNA prime-boost immunization strategy use and different DNA delivery methods. These strategies likely increase the immunogenicity of cancer DNA vaccines, thereby contributing to cancer eradication. However, cancer cells are heterogeneous and might become CTL-resistant. Thus, understanding the CTL resistance mechanism(s) employed by cancer cells is critical to develop counter-measures for this immune escape. In this review, the use of electroporation as a DNA delivery method, the strategies used to enhance the immune responses, the cancer antigens that have been tested, and the escape mechanism(s) used by tumor cells are discussed, with a focus on the progress of clinical trials using cancer DNA vaccines. PMID:25984993

  3. DNA vaccines for cervical cancer: from bench to bedside.

    PubMed

    Hung, Chien-Fu; Monie, Archana; Alvarez, Ronald D; Wu, T-C

    2007-12-31

    More than 99% of cervical cancers have been associated with human papillomaviruses (HPVs), particularly HPV type 16. The clear association between HPV infection and cervical cancer indicates that HPV serves as an ideal target for development of preventive and therapeutic vaccines. Although the recently licensed preventive HPV vaccine, Gardasil, has been shown to be safe and capable of generating significant protection against specific HPV types, it does not have therapeutic effect against established HPV infections and HPV-associated lesions. Two HPV oncogenic proteins, E6 and E7, are consistently co-expressed in HPV-expressing cervical cancers and are important in the induction and maintenance of cellular transformation. Therefore, immunotherapy targeting E6 and/or E7 proteins may provide an opportunity to prevent and treat HPV-associated cervical malignancies. It has been established that T cell-mediated immunity is one of the most crucial components to defend against HPV infections and HPV-associated lesions. Therefore, effective therapeutic HPV vaccines should generate strong E6/E7-specific T cell-mediated immune responses. DNA vaccines have emerged as an attractive approach for antigen-specific T cell-mediated immunotherapy to combat cancers. Intradermal administration of DNA vaccines via a gene gun represents an efficient way to deliver DNA vaccines into professional antigen-presenting cells in vivo. Professional antigen-presenting cells, such as dendritic cells, are the most effective cells for priming antigen-specific T cells. Using the gene gun delivery system, we tested several DNA vaccines that employ intracellular targeting strategies for enhancing MHC class I and class II presentation of encoded model antigen HPV-16 E7. Furthermore, we have developed a strategy to prolong the life of DCs to enhance DNA vaccine potency. More recently, we have developed a strategy to generate antigen-specific CD4(+) T cell immune responses to further enhance DNA vaccine

  4. Combined IL-12 Plasmid and Recombinant SjGST Enhance the Protective and Anti-pathology Effect of SjGST DNA Vaccine Against Schistosoma japonicum.

    PubMed

    Cheng, Po-Ching; Lin, Ching-Nan; Peng, Shih-Yi; Kang, Tsung-Fu; Lee, Kin-Mu

    2016-02-01

    Schistosomiasis is listed as one of most important tropical diseases and more than 200 million people are estimated to be infected. Development of a vaccine is thought to be the most effective way to control this disease. Recombinant 26-kDa glutathione S-transferase (rSjGST) has previously been reported to achieve a worm reduction rate of 42-44%. To improve the efficiency of the vaccine against Schistosoma japonicum, we immunized mice with a combination of pcDNA vector-encoded 26-kDa SjGST (pcDNA/SjGST), IL-12 expressing-plasmid (pIL-12), and rSjGST. Co-vaccination with pcDNA/SjGST, pIL-12, and rSjGST led to a reduction in worm burden, hepatic egg burden, and the size of liver tissue granulomas than that in the untreated infection controls. In addition, we detected high levels of specific IgG, IgG1, and IgG2a against the rSjGST antigen in infected mice vaccinated with this combination of pcDNA/SjGST, pIL-12, and rSjGST. Moreover, high expression levels of Th2 cytokines, including IL-4 and IL-10, were also detected in this group, without diminished levels of IL-12, INF-γ, and TNF-α cytokines that are related to parasite killing. In conclusion, we have developed a new vaccination regimen against S. japonicum infection and shown that co-immunization with pcDNA/SjGST vaccine, pIL-12, and rSjGST has significant anti-parasite, anti-hepatic egg and anti-pathology effects in mice. The efficacy of this vaccination method should be further validated in large animals such as water buffalo. This method may help to reduce the transmission of zoonotic schistosomiasis japonica. PMID:26891172

  5. Combined IL-12 Plasmid and Recombinant SjGST Enhance the Protective and Anti-pathology Effect of SjGST DNA Vaccine Against Schistosoma japonicum

    PubMed Central

    Cheng, Po-Ching; Lin, Ching-Nan; Peng, Shih-Yi; Kang, Tsung-Fu; Lee, Kin-Mu

    2016-01-01

    Schistosomiasis is listed as one of most important tropical diseases and more than 200 million people are estimated to be infected. Development of a vaccine is thought to be the most effective way to control this disease. Recombinant 26-kDa glutathione S-transferase (rSjGST) has previously been reported to achieve a worm reduction rate of 42–44%. To improve the efficiency of the vaccine against Schistosoma japonicum, we immunized mice with a combination of pcDNA vector-encoded 26-kDa SjGST (pcDNA/SjGST), IL-12 expressing-plasmid (pIL-12), and rSjGST. Co-vaccination with pcDNA/SjGST, pIL-12, and rSjGST led to a reduction in worm burden, hepatic egg burden, and the size of liver tissue granulomas than that in the untreated infection controls. In addition, we detected high levels of specific IgG, IgG1, and IgG2a against the rSjGST antigen in infected mice vaccinated with this combination of pcDNA/SjGST, pIL-12, and rSjGST. Moreover, high expression levels of Th2 cytokines, including IL-4 and IL-10, were also detected in this group, without diminished levels of IL-12, INF-γ, and TNF-α cytokines that are related to parasite killing. In conclusion, we have developed a new vaccination regimen against S. japonicum infection and shown that co-immunization with pcDNA/SjGST vaccine, pIL-12, and rSjGST has significant anti-parasite, anti-hepatic egg and anti-pathology effects in mice. The efficacy of this vaccination method should be further validated in large animals such as water buffalo. This method may help to reduce the transmission of zoonotic schistosomiasis japonica. PMID:26891172

  6. Next generation sequencing of DNA-launched Chikungunya vaccine virus.

    PubMed

    Hidajat, Rachmat; Nickols, Brian; Forrester, Naomi; Tretyakova, Irina; Weaver, Scott; Pushko, Peter

    2016-03-01

    Chikungunya virus (CHIKV) represents a pandemic threat with no approved vaccine available. Recently, we described a novel vaccination strategy based on iDNA® infectious clone designed to launch a live-attenuated CHIKV vaccine from plasmid DNA in vitro or in vivo. As a proof of concept, we prepared iDNA plasmid pCHIKV-7 encoding the full-length cDNA of the 181/25 vaccine. The DNA-launched CHIKV-7 virus was prepared and compared to the 181/25 virus. Illumina HiSeq2000 sequencing revealed that with the exception of the 3' untranslated region, CHIKV-7 viral RNA consistently showed a lower frequency of single-nucleotide polymorphisms than the 181/25 RNA including at the E2-12 and E2-82 residues previously identified as attenuating mutations. In the CHIKV-7, frequencies of reversions at E2-12 and E2-82 were 0.064% and 0.086%, while in the 181/25, frequencies were 0.179% and 0.133%, respectively. We conclude that the DNA-launched virus has a reduced probability of reversion mutations, thereby enhancing vaccine safety. PMID:26855330

  7. Vaccination of mice with ORF 5 plasmid DNA of PRRSV; enhanced effects by co-immunizing with porcine IL-15

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The open reading frame (ORF) 5 of porcine reproductive and respiratory syndrome virus (PRRSV) encodes a major envelope glycoprotein designated GP5. The GP5 protein is a candidate for developing vaccines against PRRSV infection. In this study, recombinant plasmids bearing the PRRSV GP5 gene or the po...

  8. Polymer multilayer tattooing for enhanced DNA vaccination.

    PubMed

    DeMuth, Peter C; Min, Younjin; Huang, Bonnie; Kramer, Joshua A; Miller, Andrew D; Barouch, Dan H; Hammond, Paula T; Irvine, Darrell J

    2013-04-01

    DNA vaccines have many potential benefits but have failed to generate robust immune responses in humans. Recently, methods such as in vivo electroporation have demonstrated improved performance, but an optimal strategy for safe, reproducible, and pain-free DNA vaccination remains elusive. Here we report an approach for rapid implantation of vaccine-loaded polymer films carrying DNA, immune-stimulatory RNA, and biodegradable polycations into the immune-cell-rich epidermis, using microneedles coated with releasable polyelectrolyte multilayers. Films transferred into the skin following brief microneedle application promoted local transfection and controlled the persistence of DNA and adjuvants in the skin from days to weeks, with kinetics determined by the film composition. These 'multilayer tattoo' DNA vaccines induced immune responses against a model HIV antigen comparable to electroporation in mice, enhanced memory T-cell generation, and elicited 140-fold higher gene expression in non-human primate skin than intradermal DNA injection, indicating the potential of this strategy for enhancing DNA vaccination. PMID:23353628

  9. Short-Fragment DNA Residue from Vaccine Purification Processes Promotes Immune Response to the New Inactivated EV71 Vaccine by Upregulating TLR9 mRNA.

    PubMed

    Shao, Jie; Gao, Fan; Lin, Hui-Juan; Mao, Qun-Ying; Chen, Pan; Wu, Xing; Yao, Xin; Kong, Wei; Liang, Zheng-Lun

    2016-01-01

    To reduce potential oncogenic long genomic DNA in vaccines, nuclease treatment has been applied in the purification processes. However, this action increased the residue of short-fragment DNA and its effect on vaccine potency was still elusive. In this study, we found residual sf-DNA in an inactivated EV71 vaccine could enhance humoral immune response in mice. Ag stimulation in vitro and vaccine injection in vivo revealed that TLR9 transcription level was elevated, indicating that sf-DNA could activate TLR9. These new findings will help us to understand the molecular mechanism induced by vero-cell culture-derived vaccines. PMID:27082865

  10. Short-Fragment DNA Residue from Vaccine Purification Processes Promotes Immune Response to the New Inactivated EV71 Vaccine by Upregulating TLR9 mRNA

    PubMed Central

    Shao, Jie; Gao, Fan; Lin, Hui-Juan; Mao, Qun-Ying; Chen, Pan; Wu, Xing; Yao, Xin; Kong, Wei; Liang, Zheng-Lun

    2016-01-01

    To reduce potential oncogenic long genomic DNA in vaccines, nuclease treatment has been applied in the purification processes. However, this action increased the residue of short-fragment DNA and its effect on vaccine potency was still elusive. In this study, we found residual sf-DNA in an inactivated EV71 vaccine could enhance humoral immune response in mice. Ag stimulation in vitro and vaccine injection in vivo revealed that TLR9 transcription level was elevated, indicating that sf-DNA could activate TLR9. These new findings will help us to understand the molecular mechanism induced by vero-cell culture-derived vaccines. PMID:27082865

  11. Prospects for developing an effective particle-mediated DNA vaccine against influenza.

    PubMed

    Yager, Eric J; Dean, Hansi J; Fuller, Deborah Heydenburg

    2009-09-01

    Vaccine strategies capable of conferring broad protection against both seasonal and pandemic strains of influenza are urgently needed. DNA vaccines are an attractive choice owing to their capacity to induce robust humoral and cellular immune responses at low doses and because they can be developed and manufactured rapidly to more effectively meet the threat of an influenza epidemic or pandemic. Particle-mediated epidermal delivery (PMED), or the gene gun, is a DNA vaccine delivery technology shown to induce protective levels of antibody and T-cell responses in animals and humans against a wide variety of diseases, including influenza. This review focuses on current advances toward the development of an effective PMED DNA vaccine against influenza, including strategies to enhance vaccine immunogenicity, the potential for PMED-based DNA vaccines to improve protection in the vulnerable elderly population, and the prospects for a vaccine capable of providing cross-protection against both seasonal and pandemic strains of influenza. PMID:19722894

  12. Protective immunity of grass carp immunized with DNA vaccine against Aeromonas hydrophila by using carbon nanotubes as a carrier molecule.

    PubMed

    Liu, Lei; Gong, Yu-Xin; Liu, Guang-Lu; Zhu, Bin; Wang, Gao-Xue

    2016-08-01

    To reduce the economic losses caused by diseases in aquaculture industry, more efficient and economic prophylactic measures should be urgently investigated. In this research, the effects of a novel functionalized single-walled carbon nanotubes (SWCNTs) applied as a delivery vehicle for DNA vaccine administration in juvenile grass carp against Aeromonas hydrophila were studied. Our results showed that SWCNTs loaded with DNA vaccine induced a better protection to juvenile grass carp against A. hydrophila. Moreover, SWCNTs conjugated with DNA vaccine provided significantly protective immunity compared with free DNA vaccine. Thereby, SWCNTs may be considered as a potential efficient DNA vaccine carrier to enhance the immunological activity. PMID:27343373

  13. Trial watch: DNA vaccines for cancer therapy.

    PubMed

    Senovilla, Laura; Vacchelli, Erika; Garcia, Pauline; Eggermont, Alexander; Fridman, Wolf Hervé; Galon, Jérôme; Zitvogel, Laurence; Kroemer, Guido; Galluzzi, Lorenzo

    2013-04-01

    The foundation of modern vaccinology dates back to the 1790s, when the English physician Edward Jenner uncovered the tremendous medical potential of prophylactic vaccination. Jenner's work ignited a wave of nationwide vaccination campaigns abating the incidence of multiple life-threatening infectious diseases and culminating with the eradication of natural smallpox virus, which was definitively certified by the WHO in 1980. The possibility of using vaccines against cancer was first proposed at the end of the 19th century by Paul Ehrlich and William Coley. However, it was not until the 1990s that such a hypothesis began to be intensively investigated, following the realization that the immune system is not completely unresponsive to tumors and that neoplastic cells express immunogenic tumor-associated antigens (TAAs). Nowadays, anticancer vaccines are rapidly moving from the bench to the bedside, and a few prophylactic and therapeutic preparations have already been approved by FDA for use in humans. In this setting, one interesting approach is constituted by DNA vaccines, i.e., TAA-encoding circularized DNA constructs, often of bacterial origin, that are delivered to patients as such or by means of specific vectors, including (but not limited to) liposomal preparations, nanoparticles, bacteria and viruses. The administration of DNA vaccines is most often performed via the intramuscular or subcutaneous route and is expected to cause (1) the endogenous synthesis of the TAA by myocytes and/or resident antigen-presenting cells; (2) the presentation of TAA-derived peptides on the cell surface, in association with MHC class I molecules; and (3) the activation of potentially therapeutic tumor-specific immune responses. In this Trial Watch, we will summarize the results of recent clinical trials that have evaluated/are evaluating DNA vaccines as therapeutic interventions against cancer. PMID:23734328

  14. Electroporation-enhanced delivery of nucleic acid vaccines.

    PubMed

    Broderick, Kate E; Humeau, Laurent M

    2015-02-01

    The naked delivery of nucleic acid vaccines is notoriously inefficient, and an enabling delivery technology is required to direct efficiently these constructs intracellularly. A delivery technology capable of enhancing nucleic acid uptake in both cells in tissues and in culture is electroporation (EP). EP is a physical delivery mechanism that increases the permeability of mammalian cell membranes and allows the trafficking of large macromolecules into the cell. EP has now been used extensively in the clinic and been shown to be an effective method to increase both the uptake of the construct and the breadth and magnitude of the resulting immune responses. Excitingly, 2014 saw the announcement of the first EP-enhanced DNA vaccine Phase II trial demonstrating clinical efficacy. This review seeks to introduce the reader to EP as a technology to enhance the delivery of DNA and RNA vaccines and highlight several published clinical trials using this delivery modality. PMID:25487734

  15. Intranasal DNA Vaccine for Protection against Respiratory Infectious Diseases: The Delivery Perspectives

    PubMed Central

    Xu, Yingying; Yuen, Pak-Wai; Lam, Jenny Ka-Wing

    2014-01-01

    Intranasal delivery of DNA vaccines has become a popular research area recently. It offers some distinguished advantages over parenteral and other routes of vaccine administration. Nasal mucosa as site of vaccine administration can stimulate respiratory mucosal immunity by interacting with the nasopharyngeal-associated lymphoid tissues (NALT). Different kinds of DNA vaccines are investigated to provide protection against respiratory infectious diseases including tuberculosis, coronavirus, influenza and respiratory syncytial virus (RSV) etc. DNA vaccines have several attractive development potential, such as producing cross-protection towards different virus subtypes, enabling the possibility of mass manufacture in a relatively short time and a better safety profile. The biggest obstacle to DNA vaccines is low immunogenicity. One of the approaches to enhance the efficacy of DNA vaccine is to improve DNA delivery efficiency. This review provides insight on the development of intranasal DNA vaccine for respiratory infections, with special attention paid to the strategies to improve the delivery of DNA vaccines using non-viral delivery agents. PMID:25014738

  16. DNA vaccines: a review of developments.

    PubMed

    Webster, R G; Robinson, H L

    1997-10-01

    Immunisation with purified DNA is a powerful technique for inducing immune responses. The concept is very simple, involving insertion of the gene encoding the antigen of choice into a bacterial plasmid, and injection of the plasmid into the host where the antigen is expressed and induces humoral and cellular immunity. This technology can induce immunity to all antigens that can be encoded by DNA; this includes all protein, but not carbohydrate, antigens. DNA immunisation appears to result in presentation of antigens to the host's immune system in a natural form, similar to that achieved with live attenuated vaccines. The most efficacious routes for DNA immunisation are bombardment with particles coated with DNA (gene-gun), followed by intramuscular and intradermal administration. The efficiency of transfection of host cells is low, but sufficient to induce immunological responsiveness. The DNA plasmid is retained in the transfected cells in an unintegrated form for the life of the cell. The majority of transfected cells are eliminated, but residual expression has been detected for longer periods. In animal model systems, DNA immunisation has been shown to induce protective immunity to influenza, herpes, rabies, hepatitis B and lymphocytic choriomeningitis viruses, and to malaria and mycobacteria. However, strategies to induce protective immunity to HIV and other disease agents remain to be developed. DNA vaccines permit modulation of the immune response by altering the route or method of DNA administration, by including immunostimulatory sequences in the plasmid, and by co-administration of cytokine genes with the gene encoding the antigen of interest. A T helper 1 response provides cell-mediated immune killing of infected cells and neutralising antibody production, while a T helper 2 response induces IgE and allergic responses. The advantages of DNA immunisation are: similarity to live attenuated vaccination but without the possibility of contamination with

  17. Mucosal co-immunization with AIM2 enhances protective SIgA response and increases prophylactic efficacy of chitosan-DNA vaccine against coxsackievirus B3-induced myocarditis

    PubMed Central

    Chai, Dafei; Yue, Yan; Xu, Wei; Dong, Chunsheng; Xiong, Sidong

    2014-01-01

    Coxsackievirus B3 (CVB3) infection is considered as the most common cause of viral myocarditis with no available vaccine. Considering that CVB3 mainly invades through the gastrointestinal mucosa, the development of CVB3-specific mucosal vaccine, which is the most efficient way to induce mucosal immune responses, gains more and more attention. In this study, we used absent in melanoma 2 (AIM2) as a mucosal adjuvant to enhance the immunogenicity and immunoprotection of CVB3-specific chitosan-pVP1 vaccine. Mice were intranasally co-immunized with 50 μg chitosan-pAIM2 and equal amount of chitosan-pVP1 vaccine 4 times at 2 week-intervals, and then challenged with CVB3 2 weeks after the last immunization. Compared with chitosan-pVP1 vaccine immunization alone, chitosan-pAIM2 co-immunization enhanced resistance to CVB3-induced myocarditis evidenced by significantly enhanced ejection fractions from 55.40 ± 9.35 to 80.31 ± 11.35, improved myocarditis scores from 1.50 ± 0.45 to 0.30 ± 0.15, reduced viral load from 3.33 ± 0.50 to 0.50 ± 0.65, and increased survival rate from 40.0% to 75.5%. This increased immunoprotection might be attributed to the augmented level of CVB3-specific fecal SIgA with high affinity and neutralizing ability. In addition, co-immunization with chitosan-pAIM2 remarkably facilitated dendritic cells (DCs) recruitment to mesenteric lymph nodes (MLN), and promoted the expression of IgA-inducing factors (BAFF, APRIL, iNOS, RALDH1, IL-6, TGF-β), which might account for its mucosal adjuvant effect. This strategy may represent a promising prophylactic vaccine against CVB3-induced myocarditis. PMID:24614684

  18. Targeted Collection of Plasmid DNA in Large and Growing Animal Muscles 6 Weeks after DNA Vaccination with and without Electroporation

    PubMed Central

    Dory, Daniel; Le Moigne, Vincent; Cariolet, Roland; Béven, Véronique; Keranflec'h, André; Jestin, André

    2015-01-01

    DNA vaccination has been developed in the last two decades in human and animal species as a promising alternative to conventional vaccination. It consists in the injection, in the muscle, for example, of plasmid DNA encoding the vaccinating polypeptide. Electroporation which forces the entrance of the plasmid DNA in cells at the injection point has been described as a powerful and promising strategy to enhance DNA vaccine efficacy. Due to the fact that the vaccine is composed of DNA, close attention on the fate of the plasmid DNA upon vaccination has to be taken into account, especially at the injection point. To perform such studies, the muscle injection point has to be precisely recovered and collected several weeks after injection. This is even more difficult for large and growing animals. A technique has been developed to localize precisely and collect efficiently the muscle injection points in growing piglets 6 weeks after DNA vaccination accompanied or not by electroporation. Electroporation did not significantly increase the level of remaining plasmids compared to nonelectroporated piglets, and, in all the cases, the levels were below the limit recommended by the FDA to research integration events of plasmid DNA into the host DNA. PMID:26380318

  19. DNA vaccination of poultry: The current status in 2015.

    PubMed

    Meunier, Marine; Chemaly, Marianne; Dory, Daniel

    2016-01-01

    DNA vaccination is a promising alternative strategy for developing new human and animal vaccines. The massive efforts made these past 25 years to increase the immunizing potential of this kind of vaccine are still ongoing. A relatively small number of studies concerning poultry have been published. Even though there is a need for new poultry vaccines, five parameters must nevertheless be taken into account for their development: the vaccine has to be very effective, safe, inexpensive, suitable for mass vaccination and able to induce immune responses in the presence of maternal antibodies (when appropriate). DNA vaccination should meet these requirements. This review describes studies in this field performed exclusively on birds (chickens, ducks and turkeys). No evaluations of avian DNA vaccine efficacy performed on mice as preliminary tests have been taken into consideration. The review first describes the state of the art for DNA vaccination in poultry: pathogens targeted, plasmids used and different routes of vaccine administration. Second, it presents strategies designed to improve DNA vaccine efficacy: influence of the route of administration, plasmid dose and age of birds on their first inoculation; increasing plasmid uptake by host cells; addition of immunomodulators; optimization of plasmid backbones and codon usage; association of vaccine antigens and finally, heterologous prime-boost regimens. The final part will indicate additional properties of DNA vaccines in poultry: fate of the plasmids upon inoculation, immunological considerations and the use of DNA vaccines for purposes other than preventing infectious diseases. PMID:26620840

  20. Rabies DNA vaccine in the horse: strategies to improve serological responses.

    PubMed

    Fischer, Laurent; Minke, Jules; Dufay, Nathalie; Baudu, Philippe; Audonnet, Jean Christophe

    2003-11-01

    In order for DNA vaccines to become a practical alternative to conventional vaccines their ability to induce antibody responses in large mammals needs to be improved. We used DNA vaccination against rabies in the horse as a model to test the potential of two different strategies to enhance antibody responses in a large mammalian species. The administration of the DNA vaccine in the presence of aluminum phosphate improved both the onset and the intensity of serological responses but was not potent enough to achieve seroconversion in all vaccinated ponies. However, when the DNA vaccine was formulated with the cationic lipid DMRIE-DOPE instead of aluminum phosphate, a very strong impact on both onset and intensity of serological responses was observed. This latter strategy ensured excellent seroconversion in all vaccinated ponies after a primary course of two injections, demonstrating a clear improvement of the homogeneity of the induced responses. These data indicate that rabies DNA vaccination is feasible in horses and further suggests that properly formulated DNA vaccines can generate immune responses in large veterinary species at a level comparable to the responses achieved with conventional vaccines. PMID:14575772

  1. DNA/Amphiphilic Block Copolymer Nanospheres Promote Low-dose DNA Vaccination

    PubMed Central

    McIlroy, Dorian; Barteau, Benoît; Cany, Jeannette; Richard, Peggy; Gourden, Clothilde; Conchon, Sophie; Pitard, Bruno

    2009-01-01

    Intramuscular (i.m.) DNA vaccination induces strong cellular immune responses in the mouse, but only at DNA doses that cannot be achieved in humans. Because antigen expression is weak after naked DNA injection, we screened five nonionic block copolymers of poly(ethyleneoxide)-poly(propyleneoxide) (PEO-PPO) for their ability to enhance DNA vaccination using a β-galactosidase (βGal) encoding plasmid, pCMV-βGal, as immunogen. At a high DNA dose, formulation with the tetrafunctional block copolymers 304 (molecular weight [MW] 1,650) and 704 (MW 5,500) and the triblock copolymer Lutrol (MW 8,600) increased βGal-specific interferon-γ enzyme-linked immunosorbent spot (ELISPOT) responses 2–2.5-fold. More importantly, 704 allowed significant reductions in the dose of antigen-encoding plasmid. A single injection of 2 µg pCMV-βGal with 704 gave humoral and ELISPOT responses equivalent to those obtained with 100 µg naked DNA and conferred protection in tumor vaccination models. However, 704 had no adjuvant properties for βGal protein, and immune responses were only elicited by low doses of pCMV-βGal formulated with 704 if noncoding carrier DNA was added to maintain total DNA dose at 20 µg. Overall, these results show that formulation with 704 and carrier DNA can reduce the dose of antigen-encoding plasmid by at least 50-fold. PMID:19417740

  2. Synthetic DNA Vaccines: Improved Vaccine Potency by Electroporation and Co-Delivered Genetic Adjuvants

    PubMed Central

    Flingai, Seleeke; Czerwonko, Matias; Goodman, Jonathan; Kudchodkar, Sagar B.; Muthumani, Kar; Weiner, David B.

    2013-01-01

    In recent years, DNA vaccines have undergone a number of technological advancements that have incited renewed interest and heightened promise in the field. Two such improvements are the use of genetically engineered cytokine adjuvants and plasmid delivery via in vivo electroporation (EP), the latter of which has been shown to increase antigen delivery by nearly 1000-fold compared to naked DNA plasmid delivery alone. Both strategies, either separately or in combination, have been shown to augment cellular and humoral immune responses in not only mice, but also in large animal models. These promising results, coupled with recent clinical trials that have shown enhanced immune responses in humans, highlight the bright prospects for DNA vaccines to address many human diseases. PMID:24204366

  3. Synthetic DNA vaccine strategies against persistent viral infections

    PubMed Central

    Villarreal, Daniel O; Talbott, Kendra T; Choo, Daniel K; Shedlock, Devon J; Weiner, David B

    2015-01-01

    The human body has developed an elaborate defense system against microbial pathogens and foreign antigens. However, particular microbes have evolved sophisticated mechanisms to evade immune surveillance, allowing persistence within the human host. In an effort to combat such infections, intensive research has focused on the development of effective prophylactic and therapeutic countermeasures to suppress or clear persistent viral infections. To date, popular therapeutic strategies have included the use of live-attenuated microbes, viral vectors and dendritic-cell vaccines aiming to help suppress or clear infection. In recent years, improved DNA vaccines have now re-emerged as a promising candidate for therapeutic intervention due to the development of advanced optimization and delivery technologies. For instance, genetic optimization of synthetic plasmid constructs and their encoded antigens, in vivo electroporation-mediated vaccine delivery, as well as codelivery with molecular adjuvants have collectively enhanced both transgene expression and the elicitation of vaccine-induced immunity. In addition, the development of potent heterologous prime–boost regimens has also provided significant contributions to DNA vaccine immunogenicity. Herein, the authors will focus on these recent improvements to this synthetic platform in relation to their application in combating persistent virus infection. PMID:23659301

  4. Rabies DNA vaccines for protection and therapeutic treatment.

    PubMed

    Ertl, Hildegund C J

    2003-07-01

    DNA vaccines have shown efficacy in preclinical animal models in preventing or even treating a variety of diseases caused by infectious agents, malignancies or immunological disorders. One of the main perceived advantages of DNA vaccines for use in less developed countries is their low cost. Nevertheless, in general, immune responses elicited by DNA vaccines are less potent than those induced by traditional vaccines or second generation viral recombinant vaccines, and their efficacy in human Phase I trials has been disappointing. DNA vaccines have shown good efficacy in preventing rabies in some experimental animal models; their performance in postexposure treatment has been less impressive. Considering that rabies is nearly always fatal, efficacious vaccines are available and treatment in most cases is initiated after exposure, the development of current DNA vaccines to rabies for use in humans is, at the current time, not appropriate. PMID:12831368

  5. A Combination DNA and Attenuated Simian Immunodeficiency Virus Vaccine Strategy Provides Enhanced Protection from Simian/Human Immunodeficiency Virus-Induced Disease†

    PubMed Central

    Amara, Rama Rao; Patel, Kalpana; Niedziela, Genevieve; Nigam, Pragati; Sharma, Sunita; Staprans, Silvija I.; Montefiori, David C.; Chenareddi, Lakshmi; Herndon, James G.; Robinson, Harriet L.; McClure, Harold M.; Novembre, Francis J.

    2005-01-01

    Among the most effective vaccine candidates tested in the simian immunodeficiency virus (SIV)/macaque system, live attenuated viruses have been shown to provide the best protection from challenge. To investigate if preimmunization would increase the level of protection afforded by live attenuated SIVmac239Δnef (Δnef), macaques were given two priming immunizations of DNA encoding SIV Gag and Pol proteins, with control macaques receiving vector DNA immunizations. In macaques receiving the SIV DNA inoculation, SIV-specific cellular but not humoral responses were readily detectable 2 weeks after the second DNA inoculation. Following boosting with live attenuated virus, control of Δnef replication was superior in SIV-DNA-primed macaques versus vector-DNA-primed macaques and was correlated with higher levels of CD8+/gamma-interferon-positive and/or interleukin-2-positive cells. Challenge with an intravenous inoculation of simian/human immunodeficiency virus (SHIV) strain SHIV89.6p resulted in infection of all animals. However, macaques receiving SIV DNA as the priming immunizations had statistically lower viral loads than control animals and did not develop signs of disease, whereas three of seven macaques receiving vector DNA showed severe CD4+ T-cell decline, with development of AIDS in one of these animals. No correlation of immune responses to protection from disease could be derived from our analyses. These results demonstrate that addition of a DNA prime to a live attenuated virus provided better protection from disease following challenge than live attenuated virus alone. PMID:16306607

  6. Strategies and hurdles using DNA vaccines to fish

    PubMed Central

    2014-01-01

    DNA vaccinations against fish viral diseases as IHNV at commercial level in Canada against VHSV at experimental level are both success stories. DNA vaccination strategies against many other viral diseases have, however, not yet yielded sufficient results in terms of protection. There is an obvious need to combat many other viral diseases within aquaculture where inactivated vaccines fail. There are many explanations to why DNA vaccine strategies against other viral diseases fail to induce protective immune responses in fish. These obstacles include: 1) too low immunogenicity of the transgene, 2) too low expression of the transgene that is supposed to induce protection, 3) suboptimal immune responses, and 4) too high degradation rate of the delivered plasmid DNA. There are also uncertainties with regard distribution and degradation of DNA vaccines that may have implications for safety and regulatory requirements that need to be clarified. By combining plasmid DNA with different kind of adjuvants one can increase the immunogenicity of the transgene antigen – and perhaps increase the vaccine efficacy. By using molecular adjuvants with or without in combination with targeting assemblies one may expect different responses compared with naked DNA. This includes targeting of DNA vaccines to antigen presenting cells as a central factor in improving their potencies and efficacies by means of encapsulating the DNA vaccine in certain carriers systems that may increase transgene and MHC expression. This review will focus on DNA vaccine delivery, by the use of biodegradable PLGA particles as vehicles for plasmid DNA mainly in fish. PMID:24552235

  7. Innovative DNA vaccine for human papillomavirus (HPV)-associated head and neck cancer.

    PubMed

    Wu, A; Zeng, Q; Kang, T H; Peng, S; Roosinovich, E; Pai, S I; Hung, C-F

    2011-03-01

    Human papillomavirus (HPV), particularly type 16, has been associated with a subset of head and neck cancers. The viral-encoded oncogenic proteins E6 and E7 represent ideal targets for immunotherapy against HPV-associated head and neck cancers. DNA vaccines have emerged as attractive approaches for immunotherapy due to its simplicity, safety and ease of preparation. Intradermal administration of DNA vaccine by means of gene gun represents an efficient method to deliver DNA directly into dendritic cells for priming antigen-specific T cells. We have previously shown that a DNA vaccine encoding an invariant chain (Ii), in which the class II-associated Ii peptide (CLIP) region has been replaced by a Pan-DR-epitope (PADRE) sequence to form Ii-PADRE, is capable of generating PADRE-specific CD4+ T cells in vaccinated mice. In the current study, we hypothesize that a DNA vaccine encoding Ii-PADRE linked to E6 (Ii-PADRE-E6) will further enhance E6-specific CD8+ T cell immune responses through PADRE-specific CD4+ T-helper cells. We found that mice vaccinated with Ii-PADRE-E6 DNA generated comparable levels of PADRE-specific CD4+ T-cell immune responses, as well as significantly stronger E6-specific CD8+ T-cell immune responses and antitumor effects against the lethal challenge of E6-expressing tumor compared with mice vaccinated with Ii-E6 DNA. Taken together, our data indicate that vaccination with Ii-E6 DNA with PADRE replacing the CLIP region is capable of enhancing the E6-specific CD8+ T-cell immune response generated by the Ii-E6 DNA. Thus, Ii-PADRE-E6 represents a novel DNA vaccine for the treatment of HPV-associated head and neck cancer and other HPV-associated malignancies. PMID:20981112

  8. Erbb2 DNA vaccine combined with regulatory T cell deletion enhances antibody response and reveals latent low-avidity T cells: potential and limits of its therapeutic efficacy.

    PubMed

    Rolla, Simona; Ria, Francesco; Occhipinti, Sergio; Di Sante, Gabriele; Iezzi, Manuela; Spadaro, Michela; Nicolò, Chiara; Ambrosino, Elena; Merighi, Irene Fiore; Musiani, Piero; Forni, Guido; Cavallo, Federica

    2010-06-01

    Rat (r)Erbb2 transgenic BALB-neuT mice genetically predestined to develop multiple invasive carcinomas allow an assessment of the potential of a vaccine against the stages of cancer progression. Because of rErbb2 expression in the thymus and its overexpression in the mammary gland, CD8(+) T cell clones reacting at high avidity with dominant rErbb2 epitopes are deleted in these mice. In BALB-neuT mice with diffuse and invasive in situ lesions and almost palpable carcinomas, a temporary regulatory T cells depletion combined with anti-rErbb2 vaccine markedly enhanced the anti-rErbb2 Ab response and allowed the expansion of latent pools of low-avidity CD8(+) T cells bearing TCRs repertoire reacting with the rErbb2 dominant peptide. This combination of a higher Ab response and activation of a low-avidity cytotoxic response persistently blocked tumor progression at stages in which the vaccine alone was ineffective. However, when diffuse and invasive microscopic cancers become almost palpable, this combination was no longer able to secure a significant extension of mice survival. PMID:20435927

  9. An in silico DNA vaccine against Listeria monocytogenes.

    PubMed

    Jahangiri, Abolfazl; Rasooli, Iraj; Gargari, Seyed Latif Mousavi; Owlia, Parviz; Rahbar, Mohammad Reza; Amani, Jafar; Khalili, Saeed

    2011-09-16

    Listeria monocytogenes causes listeriosis with mortality rate >20%. Listeriolysin-O (LLO), a pore-forming hemolysin, belongs to the family of cholesterol-dependent toxins (CDTX) and plays roles in the pathogenicity. In this study bioinformatic analyses were carried out on LLO sequence as a major immunodominant listerial antigen toward designing a DNA vaccine stimulating cytotoxic T-lymphocytes (CTLs). Mouse and human constructs were designed based on predicted T cell epitopes and MHC class I binders, which were then tandemly fused together. LLO-derived construct codons and a variety of critical gene expression efficiency parameters were optimized. Post-translational modifications such as glycosylation, phosphorylation were analysed. The constructs corresponded to LLO sequences of L. monocytogenes in BLAST search. Neither human nor mouse construct was allergen. Secretory pathway was location of the human construct that enhances immune induction and contribute to the efficacy of the vaccine candidate. mRNAs from optimized DNA sequences of both human and mouse constructs are more stable than the native and are suitable for initiation of translation. The constructs contain several sites for phosphorylation that could improve its degradation and subsequent entry into the MHC class I pathway. Addition of GPI anchor, myristoylation and ubiquitin signals or proline (P), glutamic acid (E), serine (S), threonine (T) (PEST)-like motifs at the N-terminal of constructs increase efficacy of the DNA vaccine. Close physical contact between the favorable immunogen and the suitable CpG oligodeoxynucleotides (CpG ODN) promotes immune response. Vectors for checking the expression of constructs in mammalian cells and for harboring the foreign genes as DNA vaccine are suggested. PMID:21791233

  10. Synergistic antitumor efficacy of combined DNA vaccines targeting tumor cells and angiogenesis.

    PubMed

    Yin, Xiaotao; Wang, Wei; Zhu, Xiaoming; Wang, Yu; Wu, Shuai; Wang, Zicheng; Wang, Lin; Du, Zhiyan; Gao, Jiangping; Yu, Jiyun

    2015-09-18

    To further enhance the antitumor efficacy of DNA vaccine, we proposed a synergistic strategy that targeted tumor cells and angiogenesis simultaneously. In this study, a Semliki Forest Virus (SFV) replicon DNA vaccine expressing 1-4 domains of murine VEGFR2 and IL12 was constructed, and was named pSVK-VEGFR2-GFc-IL12 (CAVE). The expression of VEGFR2 antigen and IL12 adjuvant molecule in 293T cells in vitro were verified by western blot and enzyme-linked immune sorbent assay (ELISA). Then CAVE was co-immunized with CAVA, a SFV replicon DNA vaccine targeting survivin and β-hCG antigens constructed previously. The antitumor efficacy of our combined replicon vaccines was evaluated in mice model and the possible mechanism was further investigated. The combined vaccines could elicit efficient humoral and cellular immune responses against survivin, β-hCG and VEGFR2 simultaneously. Compared with CAVE or CAVA vaccine alone, the combined vaccines inhibited the tumor growth and improved the survival rate in B16 melanoma mice model more effectively. Furthermore, the intratumoral microvessel density was lowest in combined vaccines group than CAVE or CAVA alone group. Therefore, this synergistic strategy of DNA vaccines for tumor treatment results in an increased antitumor efficacy, and may be more suitable for translation to future research and clinic. PMID:26253468

  11. Safety and efficacy of DNA vaccines

    PubMed Central

    Stenler, Sofia; Blomberg, Pontus; Smith, CI Edvard

    2014-01-01

    While DNA vaccination using plasmid vectors is highly attractive, there is a need for further vector optimization regarding safety, stability, and efficiency. In this commentary, we review the minicircle vector (MC), which is an entity devoid of plasmid bacterial sequences, as an alternative to the traditional plasmid construct. The commentary highlights the recent discovery by Stenler et al. (2014) that the small size of an MC enables improved resistance to the shearing forces associated with e.g. pneumatic delivery methods. This observation may have implications for the regulatory agencies’ requirement of plasmid integrity and quality. PMID:24553064

  12. Effect of vesicle size on tissue localization and immunogenicity of liposomal DNA vaccines.

    PubMed

    Carstens, Myrra G; Camps, Marcel G M; Henriksen-Lacey, Malou; Franken, Kees; Ottenhoff, Tom H M; Perrie, Yvonne; Bouwstra, Joke A; Ossendorp, Ferry; Jiskoot, Wim

    2011-06-24

    The formulation of plasmid DNA (pDNA) in cationic liposomes is a promising strategy to improve the potency of DNA vaccines. In this respect, physicochemical parameters such as liposome size may be important for their efficacy. The aim of the current study was to investigate the effect of vesicle size on the in vivo performance of liposomal pDNA vaccines after subcutaneous vaccination in mice. The tissue distribution of cationic liposomes of two sizes, 500 nm (PDI 0.6) and 140 nm (PDI 0.15), composed of egg PC, DOPE and DOTAP, with encapsulated OVA-encoding pDNA, was studied by using dual radiolabeled pDNA-liposomes. Their potency to elicit cellular and humoral immune responses was investigated upon application in a homologous and heterologous vaccination schedule with 3 week intervals. It was shown that encapsulation of pDNA into cationic lipsomes resulted in deposition at the site of injection, and strongest retention was observed at large vesicle size. The vaccination studies demonstrated a more robust induction of OVA-specific, functional CD8+ T-cells and higher antibody levels upon vaccination with small monodisperse pDNA-liposomes, as compared to large heterodisperse liposomes or naked pDNA. The introduction of a PEG-coating on the small cationic liposomes resulted in enhanced lymphatic drainage, but immune responses were not improved when compared to non-PEGylated liposomes. In conclusion, it was shown that the physicochemical properties of the liposomes are of crucial importance for their performance as pDNA vaccine carrier, and cationic charge and small size are favorable properties for subcutaneous DNA vaccination. PMID:21565240

  13. c-DNA vaccination against parasitic infections: advantages and disadvantages.

    PubMed

    Kofta, W; Wedrychowicz, H

    2001-09-12

    Recently developed technology for DNA vaccination appears to offer the good prospect for the development of a multivalent vaccines that will effectively activate both the humoral and cell mediated mechanisms of the immune system. Currently, DNA vaccination against such important parasitic diseases like malaria, leishmaniosis, toxoplasmosis, cryptosporidiosis, schistosomosis, fasciolosis offers several new opportunities. However, the outcome of vaccination depends very much on vaccine formulations, dose and route of vaccine delivery, and the species and even strain of the vaccinated host. To overcome these problems much research is still needed, specifically focused on cloning and testing of new c-DNA sequences in the following: genome projects: different ways of delivery: design of vectors containing appropriate immunostimulatory sequences and very detailed studies on safety. PMID:11522401

  14. DNA-launched live-attenuated vaccines for biodefense applications.

    PubMed

    Pushko, Peter; Lukashevich, Igor S; Weaver, Scott C; Tretyakova, Irina

    2016-09-01

    A novel vaccine platform uses DNA immunization to launch live-attenuated virus vaccines in vivo. This technology has been applied for vaccine development against positive-strand RNA viruses with global public health impact including alphaviruses and flaviviruses. The DNA-launched vaccine represents the recombinant plasmid that encodes the full-length genomic RNA of live-attenuated virus downstream from a eukaryotic promoter. When administered in vivo, the genomic RNA of live-attenuated virus is transcribed. The RNA initiates limited replication of a genetically defined, live-attenuated vaccine virus in the tissues of the vaccine recipient, thereby inducing a protective immune response. This platform combines the strengths of reverse genetics, DNA immunization and the advantages of live-attenuated vaccines, resulting in a reduced chance of genetic reversions, increased safety, and improved immunization. With this vaccine technology, the field of DNA vaccines is expanded from those that express subunit antigens to include a novel type of DNA vaccines that launch live-attenuated viruses. PMID:27055100

  15. Taking electroporation-based delivery of DNA vaccination into humans: a generic clinical protocol.

    PubMed

    Tjelle, Torunn Elisabeth; Rabussay, Dietmar; Ottensmeier, Christian; Mathiesen, Iacob; Kjeken, Rune

    2008-01-01

    We are presently aware of two early-phase DNA vaccine clinical trials in humans using electroporation-enhanced vaccine delivery. Moreover, two phase I immunogenetherapy studies are in progress and several tolerability studies have been performed on healthy volunteers. We have used knowledge from these studies to compose a template for clinical protocols involving electroporation-mediated gene delivery. In this template the emphasis will be on aspects related to electroporation. In addition, we will discuss general topics concerning electroporation-augmented DNA vaccination in human subjects. PMID:18370225

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

    PubMed

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

    2012-12-01

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

  17. Optimization of a Der p 2-based prophylactic DNA vaccine against house dust mite allergy.

    PubMed

    Pulsawat, Pinya; Pitakpolrat, Patrawadee; Prompetchara, Eakachai; Kaewamatawong, Theerayuth; Techakriengkrai, Navapon; Sirivichayakul, Sunee; Buranapraditkun, Supranee; Hannaman, Drew; Ruxrungtham, Kiat; Jacquet, Alain

    2013-03-01

    DNA vaccines encoding allergens are promising immunotherapeutics to prevent or to treat allergy through induction of allergen-specific Th1 responses. Despite anti-allergy effects observed in small rodents, DNA-based vaccines are weak immunogens in primates and humans and particularly when administered by conventional injection. The goal of the present study was to improve the immunogenicity of a prophylactic vaccine encoding the major house dust mite allergen Der p 2. In this context, we evaluated the influence of different DNA backbones including notably intron and CpG enriched sequence, the DNA dose, the in vivo delivery by electroporation as well as the heterologous prime boost regimen on the vaccine efficiency. We found that a minimal allergen expression level threshold must be reached to induce the production of specific antibodies but beyond this limit, the intensity of the immune response was independent on the DNA dose and allergen expression. The in vivo DNA delivery by electroporation drastically enhanced the production of specific antibodies but not the IFNg secretion. Vaccination of naïve mice with DNA encoding Der p 2 delivered by electroporation even at very low dose (2μg) prevented the development of house dust mite allergy through Th1-skewed immune response characterized by the drastic reduction of allergen-specific IgE, IL-5 and lung inflammation together with the induction of strong specific IgG2a titers and IFNg secretion. CpG cassette in the DNA backbone does not play a critical role in the efficient prophylaxis. Finally, comparable protective immune responses were observed when using heterologous DNA prime/protein boost or homologous DNA prime/boost. Taken together, these data suggest that the potent Th1 response induced by DNA-based vaccine encoding allergens through electroporation provides the rationale for the evaluation of DNA encoding Der p 2 into HDM allergy clinical trials. PMID:23396105

  18. West Nile virus seroconversion in penguins after vaccination with a killed virus vaccine or a DNA vaccine.

    PubMed

    Davis, Michelle R; Langan, Jennifer N; Johnson, Yvette J; Ritchie, Branson W; Van Bonn, William

    2008-12-01

    To investigate the serologic response of penguins to West Nile virus (WNV) vaccines, four species of exclusively indoor-housed penguins, negative for WNV by serology, were evaluated: Humboldt (Spheniscus humboldti), Magellanic (Spheniscus magellanicus), Gentoo (Pygoscelis papua), and Rockhopper (Eudyptes chrysoscome) penguins. Birds were inoculated with either a killed virus vaccine or a plasmid-mediated DNA WNV vaccine, and postinoculation serology was evaluated. Both vaccines induced seroconversion in all four species, and no adverse reactions were noted. Postvaccination serology results varied across species and vaccine types. However, in all four species, the killed virus vaccine resulted in a greater seroconversion rate than the DNA vaccine and in a significantly shorter time period. Additionally, the duration of the seropositive titer was significantly longer in those birds vaccinated with the killed virus vaccine compared with those vaccinated with the DNA vaccine. A subset of unvaccinated penguins serving as negative controls remained negative throughout the duration of the study despite the presence of WNV in the geographic locations of the study, suggesting that indoor housing may minimize exposure to the virus and may be an additional means of preventing WNV infection in penguins. PMID:19110700

  19. Applications of nanoparticles for DNA based rabies vaccine.

    PubMed

    Shah, Muhammad Ali A; Khan, Sajid Umar; Ali, Zeeshan; Yang, Haowen; Liu, Keke; Mao, Lanlan

    2014-01-01

    Rabies is a fatal encephalomyelitis. Most cases occur in developing countries and are transmitted by dogs. The cell culture vaccines as associated with high cost; therefore, have not replaced the unsafe brain-derived vaccines. In the developing countries these brain-derived rabies vaccines still can be seen in action. Moreover, there will be a need for vaccines against rabies-related viruses against which classical vaccines are not always effective. The worldwide incidence of rabies and the inability of currently used vaccination strategies to provide highly potent and cost-effective therapy indicate the need for alternate control strategies. DNA vaccines have emerged as the safest vaccines and best remedy for complicated diseases like hepatitis, HIV, and rabies. A number of recombinant DNA vaccines are now being developed against several diseases such as AIDS and malaria. Therefore, it can be a valuable alternative for the production of cheaper rabies vaccines against its larger spectrum of viruses. In this review we report published data on DNA-based immunization with sequences encoding rabies with special reference to nanotechnology. PMID:24730305

  20. Targeting Improves the Efficacy of a DNA Vaccine against Corynebacterium pseudotuberculosis in Sheep

    PubMed Central

    Chaplin, Paul J.; De Rose, Robert; Boyle, Jefferey S.; McWaters, Peter; Kelly, Julie; Tennent, Jan M.; Lew, Andrew M.; Scheerlinck, Jean-Pierre Y.

    1999-01-01

    A large-scale DNA vaccination trial was performed with sheep to investigate whether an antigen targeted by CTLA-4 enhanced and accelerated the humoral immune response. Vaccination with genetically detoxified phospholipase D (ΔPLD) has been shown to be effective, at least partially, against Corynebacterium pseudotuberculosis, the causal agent of caseous lymphadenitis in sheep. CTLA-4 binds to B7 on antigen-presenting cells and thus was used to direct the fusion antigens to sites of immune induction. Here we demonstrated that targeting ΔPLD as a CTLA-4 fusion protein significantly enhanced the speed, magnitude, and longevity of the antibody response compared to that obtained with DNA encoding ΔPLD. While all groups of sheep vaccinated with DNA encoding ΔPLD were afforded better protection against an experimental challenge with C. pseudotuberculosis than those immunized with an irrelevant plasmid or those left unimmunized, the best protection was provided by the targeted DNA vaccine. We propose that targeting antigens to antigen-presenting cells offers a generic strategy for enhancing the efficacy of DNA vaccines. PMID:10569760

  1. Electroporation mediated DNA vaccination directly to a mucosal surface results in improved immune responses

    PubMed Central

    Kichaev, Gleb; Mendoza, Janess M; Amante, Dinah; Smith, Trevor RF; McCoy, Jay R; Sardesai, Niranjan Y; Broderick, Kate E

    2013-01-01

    In vivo electroporation (EP) has been shown to be a highly efficient non-viral method for enhancing DNA vaccine delivery and immunogenicity, when the site of immunization is the skin or muscle of animals and humans. However, the route of entry for many microbial pathogens is via the mucosal surfaces of the human body. We have previously reported on minimally invasive, surface and contactless EP devices for enhanced DNA delivery to dermal tissue. Robust antibody responses were induced following vaccine delivery in several tested animal models using these devices. Here, we investigated extending the modality of the surface device to efficiently deliver DNA vaccines to mucosal tissue. Initially, we demonstrated reporter gene expression in the epithelial layer of buccal mucosa in a guinea pig model. There was minimal tissue damage in guinea pig mucosal tissue resulting from EP. Delivery of a DNA vaccine encoding influenza virus nucleoprotein (NP) of influenza H1N1 elicited robust and sustained systemic IgG antibody responses following EP-enhanced delivery in the mucosa. Upon further analysis, IgA antibody responses were detected in vaginal washes and sustained cellular immune responses were detected in animals immunized at the oral mucosa with the surface EP device. This data confirms that DNA delivery and EP targeting mucosal tissue directly results in both robust and sustainable humoral as well as cellular immune responses without tissue damage. These responses are seen both in the mucosa and systemically in the blood. Direct DNA vaccine delivery enhanced by EP in mucosa may have important clinical applications for delivery of prophylactic and therapeutic DNA vaccines against diseases such as HIV, HPV and pneumonia that enter at mucosal sites and require both cellular and humoral immune responses for protection. PMID:23954979

  2. Electroporation mediated DNA vaccination directly to a mucosal surface results in improved immune responses.

    PubMed

    Kichaev, Gleb; Mendoza, Janess M; Amante, Dinah; Smith, Trevor R F; McCoy, Jay R; Sardesai, Niranjan Y; Broderick, Kate E

    2013-10-01

    In vivo electroporation (EP) has been shown to be a highly efficient non-viral method for enhancing DNA vaccine delivery and immunogenicity, when the site of immunization is the skin or muscle of animals and humans. However, the route of entry for many microbial pathogens is via the mucosal surfaces of the human body. We have previously reported on minimally invasive, surface and contactless EP devices for enhanced DNA delivery to dermal tissue. Robust antibody responses were induced following vaccine delivery in several tested animal models using these devices. Here, we investigated extending the modality of the surface device to efficiently deliver DNA vaccines to mucosal tissue. Initially, we demonstrated reporter gene expression in the epithelial layer of buccal mucosa in a guinea pig model. There was minimal tissue damage in guinea pig mucosal tissue resulting from EP. Delivery of a DNA vaccine encoding influenza virus nucleoprotein (NP) of influenza H1N1 elicited robust and sustained systemic IgG antibody responses following EP-enhanced delivery in the mucosa. Upon further analysis, IgA antibody responses were detected in vaginal washes and sustained cellular immune responses were detected in animals immunized at the oral mucosa with the surface EP device. This data confirms that DNA delivery and EP targeting mucosal tissue directly results in both robust and sustainable humoral as well as cellular immune responses without tissue damage. These responses are seen both in the mucosa and systemically in the blood. Direct DNA vaccine delivery enhanced by EP in mucosa may have important clinical applications for delivery of prophylactic and therapeutic DNA vaccines against diseases such as HIV, HPV and pneumonia that enter at mucosal sites and require both cellular and humoral immune responses for protection. PMID:23954979

  3. Viral load and clinical disease enhancement associated with a lentivirus cytotoxic T lymphocyte vaccine regimen

    PubMed Central

    Mealey, Robert H.; Leib, Steven R.; Littke, Matt H.; Wagner, Bettina; Horohov, David W.; McGuire, Travis C.

    2009-01-01

    Effective DNA-based vaccines against lentiviruses will likely induce CTL against conserved viral proteins. Equine infectious anemia virus (EIAV) infects horses worldwide, and serves as a useful model for lentiviral immune control. Although attenuated live EIAV vaccines have induced protective immune responses, DNA-based vaccines have not. In particular, DNA-based vaccines have had limited success in inducing CTL responses against intracellular pathogens in the horse. We hypothesized that priming with a codon-optimized plasmid encoding EIAV Gag p15/p26 with co-administration of a plasmid encoding an equine IL-2/IgG fusion protein as a molecular adjuvant, followed by boosting with a vaccinia vector expressing Gag p15/p26, would induce protective Gag-specific CTL responses. Although the regimen induced Gag-specific CTL in four of seven vaccinated horses, CTL were not detected until after the vaccinia boost, and protective effects were not observed in EIAV challenged vaccinates. Unexpectedly, vaccinates had significantly higher viral loads and more severe clinical disease, associated with the presence of vaccine-induced CTL. It was concluded that 1.) further optimization of the timing and route of DNA immunization was needed for efficient CTL priming in vivo, 2.) co-administration of the IL-2/IgG plasmid did not enhance CTL priming by the Gag p15/p26 plasmid, 3.) vaccinia vectors are useful for lentivirus-specific CTL induction in the horse, 4.) Gag-specific CTL alone are either insufficient or a more robust Gag-specific CTL response is needed to limit EIAV viremia and clinical disease, and 5.) CTL-inducing vaccines lacking envelope immunogens can result in lentiviral disease enhancement. Although the mechanisms for enhancement associated with this vaccine regimen remain to be elucidated, these results have important implications for development of lentivirus T cell vaccines. PMID:19368787

  4. A fusion DNA vaccine that targets antigen-presenting cells increases protection from viral challenge

    PubMed Central

    Deliyannis, Georgia; Boyle, Jefferey S.; Brady, Jamie L.; Brown, Lorena E.; Lew, Andrew M.

    2000-01-01

    Improving the immunological potency, particularly the Ab response, is a serious hurdle for the protective efficacy and hence broad application of DNA vaccines. We examined the immunogenicity and protective efficacy of a hemagglutinin-based influenza DNA vaccine that was targeted to antigen-presenting cells (APCs) by fusion to CTLA4. The targeted vaccine was shown to induce an accelerated and increased Ab response (as compared with those receiving the nontargeted control) that was predominated by IgG1 and recognized conformationally dependent viral epitopes. Moreover, mice receiving the APC-targeted DNA vaccine had significantly reduced viral titers (100-fold) after a nonlethal virus challenge. The increased protective efficacy was most likely because of increased Ab responses, as cytotoxic T lymphocyte responses were not enhanced. Targeting was demonstrated by direct binding studies of CTLA4 fusion proteins to the cognate ligand (B7; expressed on APCs in vivo). In addition, a targeted protein was detected at 4-fold higher levels in draining lymph nodes within 2–24 h of administration. Therefore, this study demonstrates that targeting DNA-encoded antigen to APCs results in enhanced immunity and strongly suggests that this approach may be useful in improving the protective efficacy of DNA vaccines. PMID:10823919

  5. A fusion DNA vaccine that targets antigen-presenting cells increases protection from viral challenge

    NASA Astrophysics Data System (ADS)

    Deliyannis, Georgia; Boyle, Jefferey S.; Brady, Jamie L.; Brown, Lorena E.; Lew, Andrew M.

    2000-06-01

    Improving the immunological potency, particularly the Ab response, is a serious hurdle for the protective efficacy and hence broad application of DNA vaccines. We examined the immunogenicity and protective efficacy of a hemagglutinin-based influenza DNA vaccine that was targeted to antigen-presenting cells (APCs) by fusion to CTLA4. The targeted vaccine was shown to induce an accelerated and increased Ab response (as compared with those receiving the nontargeted control) that was predominated by IgG1 and recognized conformationally dependent viral epitopes. Moreover, mice receiving the APC-targeted DNA vaccine had significantly reduced viral titers (100-fold) after a nonlethal virus challenge. The increased protective efficacy was most likely because of increased Ab responses, as cytotoxic T lymphocyte responses were not enhanced. Targeting was demonstrated by direct binding studies of CTLA4 fusion proteins to the cognate ligand (B7; expressed on APCs in vivo). In addition, a targeted protein was detected at 4-fold higher levels in draining lymph nodes within 2-24 h of administration. Therefore, this study demonstrates that targeting DNA-encoded antigen to APCs results in enhanced immunity and strongly suggests that this approach may be useful in improving the protective efficacy of DNA vaccines.

  6. Enhancing poxvirus vectors vaccine immunogenicity

    PubMed Central

    García-Arriaza, Juan; Esteban, Mariano

    2014-01-01

    Attenuated recombinant poxvirus vectors expressing heterologous antigens from pathogens are currently at various stages in clinical trials with the aim to establish their efficacy. This is because these vectors have shown excellent safety profiles, significant immunogenicity against foreign expressed antigens and are able to induce protective immune responses. In view of the limited efficacy triggered by some poxvirus strains used in clinical trials (i.e, ALVAC in the RV144 phase III clinical trial for HIV), and of the restrictive replication capacity of the highly attenuated vectors like MVA and NYVAC, there is a consensus that further improvements of these vectors should be pursuit. In this review we considered several strategies that are currently being implemented, as well as new approaches, to improve the immunogenicity of the poxvirus vectors. This includes heterologous prime/boost protocols, use of co-stimulatory molecules, deletion of viral immunomodulatory genes still present in the poxvirus genome, enhancing virus promoter strength, enhancing vector replication capacity, optimizing expression of foreign heterologous sequences, and the combined use of adjuvants. An optimized poxvirus vector triggering long-lasting immunity with a high protective efficacy against a selective disease should be sought. PMID:25424927

  7. SIV DNA vaccine trial in macaques: post-challenge necropsy in vaccine and control groups.

    PubMed

    Lu, S; Manson, K; Wyand, M; Robinson, H L

    1997-06-01

    In this study we describe the histopathologic findings from nine macaques in a simian immunodeficiency virus (SIV) DNA vaccine trial evaluating the ability of a 5-plasmid DNA vaccine to protect against an uncloned SIVmac251 challenge (Lu et al., J. Virol. 1996, 70, 3978-3991). Three vaccinated and one control macaque developed disease and were euthanized in the first year following challenge. The other four vaccinated and one control macaque remained clinically normal and were euthanized at the end of the trial (60 weeks post-challenge). The necropsy data revealed that both diseased and clinically normal macaques had developed typical SIV-related lymphoid changes, inflammatory disorders and opportunistic infections. All animals had variable degrees of follicular and/or paracortical lymphoid hyperplasia suggesting immune activation. All but one vaccinated macaque and both control macaques had SIV-associated opportunistic infections. Within the small groups of animals, the ability to contain opportunistic infections was superior, and the overall lymphoid changes less severe, in the macaques that had received vaccine DNAs by three routes of inoculation (intravenous, intramuscular and gene gun) than in those that had received control DNAs or vaccine DNAs by gene gun only. In the future it will be important to further test how the route and method of DNA inoculation impact the efficacy of immunodeficiency virus vaccines. PMID:9234548

  8. Vaccination of rhesus macaques with a vif-deleted simian immunodeficiency virus proviral DNA vaccine

    SciTech Connect

    Sparger, Ellen E. Dubie, Robert A.; Shacklett, Barbara L.; Cole, Kelly S.; Chang, W.L.; Luciw, Paul A.

    2008-05-10

    Studies in non-human primates, with simian immunodeficiency virus (SIV) and simian/human immunodeficiency virus (SHIV) have demonstrated that live-attenuated viral vaccines are highly effective; however these vaccine viruses maintain a low level of pathogenicity. Lentivirus attenuation associated with deletion of the viral vif gene carries a significantly reduced risk for pathogenicity, while retaining the potential for virus replication of low magnitude in the host. This report describes a vif-deleted simian immunodeficiency virus (SIV)mac239 provirus that was tested as an attenuated proviral DNA vaccine by inoculation of female rhesus macaques. SIV-specific interferon-{gamma} enzyme-linked immunospot responses of low magnitude were observed after immunization with plasmid containing the vif-deleted SIV provirus. However, vaccinated animals displayed strong sustained virus-specific T cell proliferative responses and increasing antiviral antibody titers. These immune responses suggested either persistent vaccine plasmid expression or low level replication of vif-deleted SIV in the host. Immunized and unvaccinated macaques received a single high dose vaginal challenge with pathogenic SIVmac251. A transient suppression of challenge virus load and a greater median survival time was observed for vaccinated animals. However, virus loads for vaccinated and unvaccinated macaques were comparable by twenty weeks after challenge and overall survival curves for the two groups were not significantly different. Thus, a vif-deleted SIVmac239 proviral DNA vaccine is immunogenic and capable of inducing a transient suppression of pathogenic challenge virus, despite severe attenuation of the vaccine virus.

  9. DNA Vaccines: MHC II-Targeted Vaccine Protein Produced by Transfected Muscle Fibres Induces a Local Inflammatory Cell Infiltrate in Mice

    PubMed Central

    Løvås, Tom-Ole; Gundersen, Kristian; Bogen, Bjarne

    2014-01-01

    Vaccination with naked DNA holds great promise but immunogenicity needs to be improved. DNA constructs encoding bivalent proteins that bind antigen-presenting cells (APC) for delivery of antigen have been shown to enhance T and B cell responses and protection in tumour challenge experiments. However, the mechanism for the increased potency remains to be determined. Here we have constructed DNA vaccines that express the fluorescent protein mCherry, a strategy which allowed tracking of vaccine proteins. Transfected muscle fibres in mice were visualized, and their relationship to infiltrating mononuclear cells could be determined. Interestingly, muscle fibers that produced MHC class II-specific dimeric vaccine proteins with mCherry were for weeks surrounded by a localized intense cellular infiltrate composed of CD45+, MHC class II+ and CD11b+ cells. Increasing numbers of eosinophils were observed among the infiltrating cells from day 7 after immunization. The local infiltrate surrounding mCherry+ muscle fibers was dependent on the MHC II-specificity of the vaccine proteins since the control, a non-targeted vaccine protein, failed to induce similar infiltrates. Chemokines measured on day 3 in immunized muscle indicate both a DNA effect and an electroporation effect. No influence of targeting was observed. These results contribute to our understanding for why targeted DNA vaccines have an improved immunogenicity. PMID:25299691

  10. DNAVaxDB: the first web-based DNA vaccine database and its data analysis.

    PubMed

    Racz, Rebecca; Li, Xinna; Patel, Mukti; Xiang, Zuoshuang; He, Yongqun

    2014-01-01

    Since the first DNA vaccine studies were done in the 1990s, thousands more studies have followed. Here we report the development and analysis of DNAVaxDB (http://www.violinet.org/dnavaxdb), the first publically available web-based DNA vaccine database that curates, stores, and analyzes experimentally verified DNA vaccines, DNA vaccine plasmid vectors, and protective antigens used in DNA vaccines. All data in DNAVaxDB are annotated from reliable resources, particularly peer-reviewed articles. Among over 140 DNA vaccine plasmids, some plasmids were more frequently used in one type of pathogen than others; for example, pCMVi-UB for G- bacterial DNA vaccines, and pCAGGS for viral DNA vaccines. Presently, over 400 DNA vaccines containing over 370 protective antigens from over 90 infectious and non-infectious diseases have been curated in DNAVaxDB. While extracellular and bacterial cell surface proteins and adhesin proteins were frequently used for DNA vaccine development, the majority of protective antigens used in Chlamydophila DNA vaccines are localized to the inner portion of the cell. The DNA vaccine priming, other vaccine boosting vaccination regimen has been widely used to induce protection against infection of different pathogens such as HIV. Parasitic and cancer DNA vaccines were also systematically analyzed. User-friendly web query and visualization interfaces are available in DNAVaxDB for interactive data search. To support data exchange, the information of DNA vaccines, plasmids, and protective antigens is stored in the Vaccine Ontology (VO). DNAVaxDB is targeted to become a timely and vital source of DNA vaccines and related data and facilitate advanced DNA vaccine research and development. PMID:25104313

  11. DNAVaxDB: the first web-based DNA vaccine database and its data analysis

    PubMed Central

    2014-01-01

    Since the first DNA vaccine studies were done in the 1990s, thousands more studies have followed. Here we report the development and analysis of DNAVaxDB (http://www.violinet.org/dnavaxdb), the first publically available web-based DNA vaccine database that curates, stores, and analyzes experimentally verified DNA vaccines, DNA vaccine plasmid vectors, and protective antigens used in DNA vaccines. All data in DNAVaxDB are annotated from reliable resources, particularly peer-reviewed articles. Among over 140 DNA vaccine plasmids, some plasmids were more frequently used in one type of pathogen than others; for example, pCMVi-UB for G- bacterial DNA vaccines, and pCAGGS for viral DNA vaccines. Presently, over 400 DNA vaccines containing over 370 protective antigens from over 90 infectious and non-infectious diseases have been curated in DNAVaxDB. While extracellular and bacterial cell surface proteins and adhesin proteins were frequently used for DNA vaccine development, the majority of protective antigens used in Chlamydophila DNA vaccines are localized to the inner portion of the cell. The DNA vaccine priming, other vaccine boosting vaccination regimen has been widely used to induce protection against infection of different pathogens such as HIV. Parasitic and cancer DNA vaccines were also systematically analyzed. User-friendly web query and visualization interfaces are available in DNAVaxDB for interactive data search. To support data exchange, the information of DNA vaccines, plasmids, and protective antigens is stored in the Vaccine Ontology (VO). DNAVaxDB is targeted to become a timely and vital source of DNA vaccines and related data and facilitate advanced DNA vaccine research and development. PMID:25104313

  12. Successive site translocating inoculation potentiates DNA/recombinant vaccinia vaccination

    PubMed Central

    Ren, Yanqin; Wang, Na; Hu, Weiguo; Zhang, Xiaoyan; Xu, Jianqing; Wan, Yanmin

    2015-01-01

    DNA vaccines have advantages over traditional vaccine modalities; however the relatively low immunogenicity restrains its translation into clinical use. Further optimizations are needed to get the immunogenicity of DNA vaccine closer to the level required for human use. Here we show that intramuscularly inoculating into a different limb each time significantly improves the immunogenicities of both DNA and recombinant vaccinia vaccines during multiple vaccinations, compared to repeated vaccination on the same limb. We term this strategy successive site translocating inoculation (SSTI). SSTI could work in synergy with genetic adjuvant and DNA prime-recombinant vaccinia boost regimen. By comparing in vivo antigen expression, we found that SSTI avoided the specific inhibition of in vivo antigen expression, which was observed in the limbs being repeatedly inoculated. Employing in vivo T cell depletion and passive IgG transfer, we delineated that the inhibition was not mediated by CD8+ T cells but by specific antibodies. Finally, by using C3−/− mouse model and in vivo NK cells depletion, we identified that specific antibodies negatively regulated the in vivo antigen expression primarily in a complement depended way. PMID:26667202

  13. Testing the Efficacy of a Multi-Component DNA-Prime/DNA-Boost Vaccine against Trypanosoma cruzi Infection in Dogs

    PubMed Central

    Aparicio-Burgos, José E.; Ochoa-García, Laucel; Zepeda-Escobar, José Antonio; Gupta, Shivali; Dhiman, Monisha; Martínez, José Simón; de Oca-Jiménez, Roberto Montes; Arreola, Margarita Val; Barbabosa-Pliego, Alberto; Vázquez-Chagoyán, Juan C.; Garg, Nisha Jain

    2011-01-01

    Background Trypanosoma cruzi, the etiologic agent of Chagas Disease, is a major vector borne health problem in Latin America and an emerging infectious disease in the United States. Methods We tested the efficacy of a multi-component DNA-prime/DNA-boost vaccine (TcVac1) against experimental T. cruzi infection in a canine model. Dogs were immunized with antigen-encoding plasmids and cytokine adjuvants, and two weeks after the last immunization, challenged with T. cruzi trypomastigotes. We measured antibody responses by ELISA and haemagglutination assay, parasitemia and infectivity to triatomines by xenodiagnosis, and performed electrocardiography and histology to assess myocardial damage and tissue pathology. Results Vaccination with TcVac1 elicited parasite-and antigen-specific IgM and IgG (IgG2>IgG1) responses. Upon challenge infection, TcVac1-vaccinated dogs, as compared to non-vaccinated controls dogs, responded to T. cruzi with a rapid expansion of antibody response, moderately enhanced CD8+ T cell proliferation and IFN-γ production, and suppression of phagocytes’ activity evidenced by decreased myeloperoxidase and nitrite levels. Subsequently, vaccinated dogs controlled the acute parasitemia by day 37 pi (44 dpi in non-vaccinated dogs), and exhibited a moderate decline in infectivity to triatomines. TcVac1-immunized dogs did not control the myocardial parasite burden and electrocardiographic and histopatholgic cardiac alterations that are the hallmarks of acute Chagas disease. During the chronic stage, TcVac1-vaccinated dogs exhibited a moderate decline in cardiac alterations determined by EKG and anatomo-/histo-pathological analysis while chronically-infected/non-vaccinated dogs continued to exhibit severe EKG alterations. Conclusions Overall, these results demonstrated that TcVac1 provided a partial resistance to T. cruzi infection and Chagas disease, and provide an impetus to improve the vaccination strategy against Chagas disease. PMID:21625470

  14. Influenza nucleoprotein DNA vaccination by a skin targeted, dry coated, densely packed microprojection array (Nanopatch) induces potent antibody and CD8(+) T cell responses.

    PubMed

    Fernando, Germain J P; Zhang, Jin; Ng, Hwee-Ing; Haigh, Oscar L; Yukiko, Sally R; Kendall, Mark A F

    2016-09-10

    DNA vaccines have many advantages such as thermostability and the ease and rapidity of manufacture; for example, in an influenza pandemic situation where rapid production of vaccine is essential. However, immunogenicity of DNA vaccines was shown to be poor in humans unless large doses of DNA are used. If a highly efficacious DNA vaccine delivery system could be identified, then DNA vaccines have the potential to displace protein vaccines. In this study, we show in a C57BL/6 mouse model, that the Nanopatch, a microprojection array of high density (>21,000 projections/cm(2)), could be used to deliver influenza nucleoprotein DNA vaccine to skin, to generate enhanced antigen specific antibody and CD8(+) T cell responses compared to the conventional intramuscular (IM) delivery by the needle and syringe. Antigen specific antibody was measured using ELISA assays of mice vaccinated with a DNA plasmid containing the nucleoprotein gene of influenza type A/WSN/33 (H1N1). Antigen specific CD8(+) T cell responses were measured ex-vivo in splenocytes of mice using IFN-γ ELISPOT assays. These results and our previous antibody and CD4(+) T cell results using the Nanopatch delivered HSV DNA vaccine indicate that the Nanopatch is an effective delivery system of general utility that could potentially be used in humans to increase the potency of the DNA vaccines. PMID:27381247

  15. Prospects and progress of DNA vaccines for treating hepatitis B.

    PubMed

    Chen, Margaret; Jagya, Neetu; Bansal, Ruchi; Frelin, Lars; Sällberg, Matti

    2016-05-01

    The hepatitis B virus (HBV) is a global cause of liver disease. The preventive HBV vaccine has effectively reduced the disease burden. However, an estimated 340 million chronic HBV cases are in need of treatment. Current standard therapy for chronic HBV blocks reverse transcription. As this therapy blocks viral maturation and not viral protein expression, any immune inhibition exerted by these proteins will remain throughout therapy. This may help to explain why these drugs rarely induce off-therapy responses. Albeit some restoration of immune function occurs during therapy, this is clearly insufficient to control replication. Central questions when considering therapeutic DNA vaccination as an addition to blocking virus production are as follows: what does one hope to achieve? What do we think is wrong and how can the vaccination correct this? We here discuss different scenarios with respect to the lack of success of tested DNA vaccines, and suggest strategies for improvement. PMID:26652035

  16. Enhancing public confidence in vaccines through independent oversight of postlicensure vaccine safety.

    PubMed

    Salmon, Daniel A; Moulton, Lawrence H; Halsey, Neal A

    2004-06-01

    The National Immunization Program of the Centers for Disease Control and Prevention is responsible for controlling infectious diseases through vaccination, but the program also plays a key role in postlicensure vaccine safety assessment. The time has come to separate postlicensure vaccine safety assessment from vaccine risk management as recommended by the National Research Council of the National Academy of Sciences.The National Transportation Safety Board offers a useful model for developing an independent National Vaccine Safety Board that would have the authority to leverage resources and expertise of various government agencies, academia, and industry to oversee postlicensure vaccine safety investigations. Such a board would have been useful in recent vaccine safety concerns, and its independence from government programs would ensure optimal vaccine safety and enhance public confidence in vaccines. PMID:15249296

  17. A sindbis virus replicon-based DNA vaccine encoding the rabies virus glycoprotein elicits immune responses and complete protection in mice from lethal challenge.

    PubMed

    Saxena, Sonal; Dahiya, Shyam S; Sonwane, Arvind A; Patel, Chhabi Lal; Saini, Mohini; Rai, A; Gupta, Praveen K

    2008-12-01

    A sindbis virus replicon-based DNA vaccine encoding rabies virus glycoprotein (G) was developed by subcloning rabies G gene into a sindbis virus replicon-based vaccine vector (pAlpha). The self-amplification of RNA transcripts and translation efficiency of rabies G was analyzed in pAlpha-Rab-G-transfected mammalian cells using RT-PCR, SDS-PAGE and Western blot analysis. The transfected cells also showed induction of apoptosis which is an important event in the enhancement of immune responses. Further, immune responses induced with replicon-based rabies DNA vaccine (pAlpha-Rab-G) was compared with conventional rabies DNA vaccine and commercial cell culture vaccine (Rabipur) in intramuscularly injected mice. The mice immunized with replicon-based rabies DNA vaccine induced humoral and cell mediated immune responses better than conventional rabies DNA vaccine however, comparable to Rabipur vaccine. On challenge with rabies virus CVS strain, replicon-based rabies DNA vaccine conferred complete protection similar to Rabipur. These results demonstrate that replicon-based rabies DNA vaccine is effective in inducing both humoral and cellular immune responses and can be considered as effective vaccine against rabies. PMID:18848857

  18. Overview of recent DNA vaccine development for fish

    USGS Publications Warehouse

    Kurath, G.

    2005-01-01

    Since the first description of DNA vaccines for fish in 1996, numerous studies of genetic immunisation against the rhabdovirus pathogens infectious haematopoietic necrosis virus (IHNV) and viral haemorrhagic septicaemia virus (VHSV) have established their potential as both highly efficacious biologicals and useful basic research tools. Single small doses of rhabdovirus DNA constructs provide extremely strong protection against severe viral challenge under a variety of conditions. DNA vaccines for several other important fish viruses, bacteria, and parasites are under investigation, but they have not yet shown high efficacy. Therefore, current research is focussed on mechanistic studies to understand the basis of protection, and on improvement of the nucleic acid vaccine applications against a wider range of fish pathogens.

  19. Trial watch: Naked and vectored DNA-based anticancer vaccines

    PubMed Central

    Bloy, Norma; Buqué, Aitziber; Aranda, Fernando; Castoldi, Francesca; Eggermont, Alexander; Cremer, Isabelle; Sautès-Fridman, Catherine; Fucikova, Jitka; Galon, Jérôme; Spisek, Radek; Tartour, Eric; Zitvogel, Laurence; Kroemer, Guido; Galluzzi, Lorenzo

    2015-01-01

    One type of anticancer vaccine relies on the administration of DNA constructs encoding one or multiple tumor-associated antigens (TAAs). The ultimate objective of these preparations, which can be naked or vectored by non-pathogenic viruses, bacteria or yeast cells, is to drive the synthesis of TAAs in the context of an immunostimulatory milieu, resulting in the (re-)elicitation of a tumor-targeting immune response. In spite of encouraging preclinical results, the clinical efficacy of DNA-based vaccines employed as standalone immunotherapeutic interventions in cancer patients appears to be limited. Thus, efforts are currently being devoted to the development of combinatorial regimens that allow DNA-based anticancer vaccines to elicit clinically relevant immune responses. Here, we discuss recent advances in the preclinical and clinical development of this therapeutic paradigm. PMID:26155408

  20. DNA vaccine prime and recombinant FPV vaccine boost: an important candidate immunization strategy to control bluetongue virus type 1.

    PubMed

    Li, Junping; Yang, Tao; Xu, Qingyuan; Sun, Encheng; Feng, Yufei; Lv, Shuang; Zhang, Qin; Wang, Haixiu; Wu, Donglai

    2015-10-01

    Bluetongue virus (BTV) is the causative agent of bluetongue (BT), an important sheep disease that caused great economic loss to the sheep industry. There are 26 BTV serotypes based on the outer protein VP2. However, the serotypes BTV-1 and BTV-16 are the two most prevalent serotypes in China. Vaccination is the most effective method of preventing viral infections. Therefore, the need for an effective vaccine against BTV is urgent. In this study, DNA vaccines and recombinant fowlpox virus (rFPV) vaccines expressing VP2 alone or VP2 in combination with VP5 or co-expressing the VP2 and VP5 proteins of BTV-1 were evaluated in both mice and sheep. Several strategies were tested in mice, including DNA vaccine prime and boost, rFPV vaccine prime and boost, and DNA vaccine prime and rFPV vaccine boost. We then determined the best vaccine strategy in sheep. Our results indicated that a strategy combining a DNA vaccine prime (co-expressing VP2 and VP5) followed by an rFPV vaccine boost (co-expressing VP2 and VP5) induced a high titer of neutralizing antibodies in sheep. Therefore, our data suggest that a DNA vaccine consisting of a pCAG-(VP2+VP5) prime and an rFPV-(VP2+VP5) boost is an important candidate for the design of a novel vaccine against BTV-1. PMID:26048472

  1. Vaxfectin-formulated influenza DNA vaccines encoding NP and M2 viral proteins protect mice against lethal viral challenge.

    PubMed

    Jimenez, Gretchen S; Planchon, Rodrick; Wei, Qun; Rusalov, Denis; Geall, Andrew; Enas, Joel; Lalor, Peggy; Leamy, Vicky; Vahle, Ruth; Luke, Catherine J; Rolland, Alain; Kaslow, David C; Smith, Larry R

    2007-01-01

    Next generation influenza vaccines containing conserved antigens may enhance immunity against seasonal or pandemic influenza virus strains. Using a plasmid DNA (pDNA)-based vaccine approach, we systematically tested combinations of NP, M1, and M2 antigens derived from consensus sequences for protection against lethal influenza challenge and compared formulations for adjuvanting low pDNA vaccine doses. The highest level of protection at the lowest pDNA doses was provided by Vaxfectin-formulated NP + M2. Vaxfectin adjuvanticity was confirmed with a low dose of HA pDNA. These promising proof-of-concept data support the clinical development of Vaxfectin-formulated pDNA encoding NP + M2 consensus proteins. PMID:17637571

  2. Multivalent Human Papillomavirus L1 DNA Vaccination Utilizing Electroporation

    PubMed Central

    Kwak, Kihyuck; Jiang, Rosie; Jagu, Subhashini; Wang, Joshua W.; Wang, Chenguang; Christensen, Neil D.; Roden, Richard B. S.

    2013-01-01

    Objectives Naked DNA vaccines can be manufactured simply and are stable at ambient temperature, but require improved delivery technologies to boost immunogenicity. Here we explore in vivo electroporation for multivalent codon-optimized human papillomavirus (HPV) L1 and L2 DNA vaccination. Methods Balb/c mice were vaccinated three times at two week intervals with a fusion protein comprising L2 residues ∼11−88 of 8 different HPV types (11−88×8) or its DNA expression vector, DNA constructs expressing L1 only or L1+L2 of a single HPV type, or as a mixture of several high-risk HPV types and administered utilizing electroporation, i.m. injection or gene gun. Serum was collected two weeks and 3 months after the last vaccination. Sera from immunized mice were tested for in-vitro neutralization titer, and protective efficacy upon passive transfer to naive mice and vaginal HPV challenge. Heterotypic interactions between L1 proteins of HPV6, HPV16 and HPV18 in 293TT cells were tested by co-precipitation using type-specific monoclonal antibodies. Results Electroporation with L2 multimer DNA did not elicit detectable antibody titer, whereas DNA expressing L1 or L1+L2 induced L1-specific, type-restricted neutralizing antibodies, with titers approaching those induced by Gardasil. Co-expression of L2 neither augmented L1-specific responses nor induced L2-specific antibodies. Delivery of HPV L1 DNA via in vivo electroporation produces a stronger antibody response compared to i.m. injection or i.d. ballistic delivery via gene gun. Reduced neutralizing antibody titers were observed for certain types when vaccinating with a mixture of L1 (or L1+L2) vectors of multiple HPV types, likely resulting from heterotypic L1 interactions observed in co-immunoprecipitation studies. High titers were restored by vaccinating with individual constructs at different sites, or partially recovered by co-expression of L2, such that durable protective antibody titers were achieved for each type

  3. A comparison of DNA vaccines for the rabies-related virus, Mokola.

    PubMed

    Nel, L H; Niezgoda, M; Hanlon, C A; Morril, P A; Yager, P A; Rupprecht, C E

    2003-06-01

    Mokola virus, a rabies-related virus, has been reported to date from the African continent only. Like rabies virus, it is highly pathogenic, causes acute encephalitis, and zoonotic events have been documented. Although believed to be rare, there has been an unexplained increase in the number of isolations of the virus in South Africa in recent years. We have cloned and sequenced the glycoprotein (G) and nucleoprotein (N) genes from a South African Mokola virus, and used these in the construction of different DNA vaccines for immunization against Mokola virus. Four vaccines, utilizing different promoters and DNA backbone compositions, were generated and compared for efficacy in protection against Mokola virus. In one of these, both the Mokola virus G and N genes were co-expressed. Two of the single G-expressing DNA vaccines (based on pSG5 and pCI-neo, respectively) protected laboratory mice against lethal challenge, despite major differences in their promoters. However, neither vaccine was fully protective in a single immunization only. Serological assays confirmed titers of virus-neutralizing antibodies after immunization, which increased upon booster vaccine administration. A third construct (based on pBudCE4) was less effective in inducing a protective immune response, despite employing a strong CMV enhancer/promoter also used in the pCI-neo plasmid. Dual expression of Mokola virus G and N genes in pBudCE4 did not enhance its efficacy, under the conditions described. In addition, no significant utility could be demonstrated for a combined prime-boost approach, as no cross-protective immunity was observed against rabies or Mokola viruses from the use of pSG5-mokG or vaccinia-rabies glycoprotein recombinant virus vaccines, respectively, even though both vaccines provided 60-100% protection against homologous virus challenge. PMID:12744896

  4. 78 FR 29698 - Availability of an Environmental Assessment for Field Testing a Canine Lymphoma Vaccine, DNA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-21

    ... a Canine Lymphoma Vaccine, DNA AGENCY: Animal and Plant Health Inspection Service, USDA. ACTION... testing, and then to field test, an unlicensed Canine Lymphoma Vaccine, DNA. The environmental assessment... Lymphoma Vaccine, DNA. Possible Field Test Locations: Arizona, Florida, Georgia, New York, North...

  5. Enhanced protective efficacy against Mycobacterium tuberculosis afforded by BCG prime-DNA boost regimen in an early challenge mouse model is associated with increased splenic interleukin-2-producing CD4 T-cell frequency post-vaccination.

    PubMed

    Kang, Han; Yuan, Qin; Ma, Hui; Hu, Zhi-Dong; Han, De-Ping; Wu, Kang; Lowrie, Douglas B; Fan, Xiao-Yong

    2014-12-01

    The development of improved vaccines and vaccination strategies against Mycobacterium tuberculosis has been hindered by a limited understanding of the immune correlates of anti-tuberculosis protective immunity. Simple measurement of interferon-γ frequency or production per se does not provide adequate prediction of immune protection. In this study, we examined the relationship between T-cell immune responses and protective efficacy conferred by the heterologous vaccination strategy, bacillus Calmette-Guérin (BCG) prime-Ag85A DNA boost (B/D), in an early challenge mouse model of pulmonary tuberculosis. The results demonstrated that mice vaccinated with the B/D regimen had a significantly reduced bacillary load compared with BCG-vaccinated mice, and the reduction in colony-forming units was associated with decreased pathology and lower levels of inflammatory cytokines in the infected lungs. Further analysis of immunogenicity showed that the superior protection afforded by the B/D regimen was associated with significantly increased frequency of splenic interleukin-2 (IL-2) -producing CD4 T cells and increased IL-2 production when measured as integrated mean fluorescence intensity post-vaccination as well. These data suggest that measurement of elevated frequency of IL-2-producing CD4 T cells or IL-2 production in the spleens of vaccinated mice can predict vaccine efficacy, at least in the B/D strategy, and add to the accumulating body of evidence suggesting that BCG prime-boost strategies may be a useful approach to the control of M. tuberculosis infection. PMID:24965530

  6. The Mycobacterium bovis BCG prime-Rv0577 DNA boost vaccination induces a durable Th1 immune response in mice.

    PubMed

    Gu, Dongqing; Chen, Wei; Mi, Youjun; Gong, Xueli; Luo, Tao; Bao, Lang

    2016-04-01

    Tuberculosis remains a major global health problem and effective vaccines are urgently needed. In this study, we used the combined DNA- and protein-based vaccines of immunodominant antigen Rv0577 to boost BCG and evaluated their immunogenicity in BALB/c mice. Our data suggest that the booster vaccine may substantially enhance the immunogenicity of BCG and strengthen both CD4+ T cell-mediated Th1 and CD8+ T cell-mediated cytolytic responses. Compared with the protein-based vaccine, the DNA-based vaccine can induce more durable Th1 immune response, characterized by high levels of antibody response, proliferation response, percentages of CD4+/CD8+ and cytokine secretion in antigen-stimulated splenocyte cultures. In conclusion, we for the first time, developed a protein- and plasmid DNA-based booster vaccine based on Rv0577. Our findings suggest that antigen Rv0577-based DNA vaccine is immunogenic and can efficiently boost BCG, which could be helpful in the design of an efficient vaccination strategy against TB. PMID:26922320

  7. Immunogenicity of candidate chimeric DNA vaccine against tuberculosis and leishmaniasis.

    PubMed

    Dey, Ayan; Kumar, Umesh; Sharma, Pawan; Singh, Sarman

    2009-08-13

    Mycobacterium tuberculosis and Leishmania donovani are important intracellular pathogens, especially in Indian context. In India and other South East Asian countries, both these infections are highly endemic and in about 20% cases co-infection of these pathogens is reported. For both these pathogens cell mediated immunity plays most important role. The available treatment of these infections is either prolonged or cumbersome or it is ineffective in controlling the outbreaks and spread. Therefore, potentiation of a common host defense mechanism can be used to prevent both the infections simultaneously. In this study we have developed a novel chimeric DNA vaccine candidate comprising the esat-6 gene of M. tuberculosis and kinesin motor domain gene of L. donovani. After developing this novel chimera, its immunogenicity was studied in mouse model. The immune response was compared with individual constructs of esat-6 and kinesin motor domain. The results showed that immunization with chimeric DNA vaccine construct resulted in stronger IFN-gamma and IL-2 response against kinesin (3012+/-102 and 367.5+/-8.92pg/ml) and ESAT-6 (1334+/-46.5 and 245.1+/-7.72pg/ml) in comparison to the individual vaccine constructs. The reciprocal immune response (IFN-gamma and IL-2) against individual construct was lower (kinesin motor domain: 1788+/-36.48 and 341.8+/-9.801pg/ml and ESAT-6: 867.0+/-47.23 and 170.8+/-4.578pg/ml, respectively). The results also suggest that using the chimeric construct both proteins yielded a reciprocal adjuvant affect over each other as the IFN-gamma production against chimera vaccination is statistically significant (p<0.0001) than individual construct vaccination. From this pilot study we could envisage that the chimeric DNA vaccine construct may offer an attractive strategy in controlling co-infection of leishmaniasis and tuberculosis and have important implication in future vaccine design. PMID:19559111

  8. DNA-antiviral vaccines: new developments and approaches--a review.

    PubMed

    Giese, M

    1998-01-01

    Current vaccines can be divided into "live," "recombinant" and "killed" vaccines. Live vaccines are traditionally composed of attenuated viruses or bacteria, selected for their reduced pathogenicity. Recombinant vaccines, driven by a viral or bacterial vector express foreign antigens, or only recombinant proteins injected as antigen. Killed vaccines consist of inactivated whole pathogens. But all these traditional vaccines have some disadvantages: Attenuated live vaccine are able to undergo mutation and as mutated viruses or bacteria can now provoke the diseases against which the vaccine should protect the organism. A further disadvantage of live vaccines is the possibility of shedding which is a real problem especially in veterinary medicine. Clearly, there is a need for better vaccines to protect against diseases without the disadvantages associated with vaccines presently in use. Modern vaccines might be characterized as safe, no risk of reversion to pathogenicity, and they should be stable without the necessity of a "cold chain." Production should be simple, standardized and inexpensive. Vaccine development has now been improved by the ability to use direct inoculations of plasmid DNA encoding viral or bacterial proteins. One of the major benefits of DNA-vaccines, variously termed "DNA-, genetic- or nucleic acid-immunization," is the endogenous synthesis of the encoded protein. Therefore DNA vaccines mimic natural infection and provoke both strong humoral and cellular immune response. This review summarizes new developments and approaches of DNA vaccination and explains the construction of expression plasmids as well as possible mechanisms of immune responses. PMID:9926398

  9. Intravaginal HPV DNA vaccination with electroporation induces local CD8+ T-cell immune responses and antitumor effects against cervicovaginal tumors

    PubMed Central

    Sun, Y; Peng, S; Qiu, J; Miao, J; Yang, B; Jeang, J; Hung, C-F; Wu, T-C

    2015-01-01

    Therapeutic human papillomavirus (HPV) vaccines have the potential to inhibit the progression of an established HPV infection to precancer and cancer lesions by targeting HPV oncoproteins. We have previously developed a therapeutic DNA vaccine encoding calreticulin (CRT) linked to E7, CRT/E7 DNA vaccine, for use in the treatment of HPV-associated lesions. Since the transfection efficiency of DNA vaccines administered in vivo is typically low, we examined the use of electroporation as well as different routes of administration to enhance antigen-specific tumor control. We tested the effects of the CRT/E7 DNA vaccine administered intramuscularly or intravaginally, with or without electroporation, on the generation of CD8+ T-cell immunity and therapeutic antitumor effects in HPV16 E7-expressing cervicovaginal tumor-bearing mice. We found that intravaginal vaccination of CRT/E7 DNA followed by electroporation-induced potent E7-specific CD8+ T-cell responses in the cervicovaginal tract, compared with intramuscular injection followed by electroporation. Furthermore, tumor-bearing mice vaccinated intravaginally followed by electroporation had an enhanced survival, antitumor effects and local production of IFN-γ+CD8+ T cells compared with those vaccinated intramuscularly with electroporation. Thus, we show that intravaginal CRT/E7 DNA vaccination followed by electroporation generates the most potent therapeutic antitumor effects against an orthotopic E7-expressing tumor model. The current study will have significant clinical implications once a clinically applicable electroporation device for intravaginal use becomes available. PMID:25786869

  10. Clinical Development of a Cytomegalovirus DNA Vaccine: From Product Concept to Pivotal Phase 3 Trial

    PubMed Central

    Smith, Larry R.; Wloch, Mary K.; Chaplin, Jennifer A.; Gerber, Michele; Rolland, Alain P.

    2013-01-01

    2013 marks a milestone year for plasmid DNA vaccine development as a first-in-class cytomegalovirus (CMV) DNA vaccine enters pivotal phase 3 testing. This vaccine consists of two plasmids expressing CMV antigens glycoprotein B (gB) and phosphoprotein 65 (pp65) formulated with a CRL1005 poloxamer and benzalkonium chloride (BAK) delivery system designed to enhance plasmid expression. The vaccine’s planned initial indication under investigation is for prevention of CMV reactivation in CMV-seropositive (CMV+) recipients of an allogeneic hematopoietic stem cell transplant (HCT). A randomized, double-blind placebo-controlled phase 2 proof-of-concept study provided initial evidence of the safety of this product in CMV+ HCT recipients who underwent immune ablation conditioning regimens. This study revealed a significant reduction in viral load endpoints and increased frequencies of pp65-specific interferon-γ-producing T cells in vaccine recipients compared to placebo recipients. The results of this endpoint-defining trial provided the basis for defining the primary and secondary endpoints of a global phase 3 trial in HCT recipients. A case study is presented here describing the development history of this vaccine from product concept to initiation of the phase 3 trial. PMID:26344340

  11. Cholera toxin B subunit acts as a potent systemic adjuvant for HIV-1 DNA vaccination intramuscularly in mice

    PubMed Central

    Hou, Jue; Liu, Ying; Hsi, Jenny; Wang, Hongzhi; Tao, Ran; Shao, Yiming

    2014-01-01

    Cholera toxin B subunit (CTB) was investigated as a classical mucosal adjuvant that can increase vaccine immunogenicity. In this study, we found out the in vitro efficacy of cholera toxin B subunit (CTB) in activating mice bone marrow-derived dendritic cells (BMDCs) through Toll-like receptor signaling pathways. In vitro RNA and transcriptional level profiling arrays revealed that CTB guides high levels of Th1 and Th2 type cytokines, inflammatory cytokines, and chemokines. Based on the robustness of these profiling results, we examined the induction of HIV Env-specific immunity by CTB co-inoculated with HIV Env DNA vaccine intramuscularly in vivo. CTB enhanced HIV-Env specific cellular immune responses in Env-specific IFN-γ ELISPOT, compared with DNA vaccine alone. Moreover, CTB induced high levels of Env specific humoral response and promoted antibody maturation after the third round of vaccination. This combination immunization strategy induced a Th2-type bias response which is indicative of a high ratio of IgG1/IgG2a. This study reports that CTB as a classical mucosal adjuvant could enhance HIV-1 DNA-based vaccine immunogenicity intramuscularly; therefore, these findings suggest that CTB could serve as an effective candidate adjuvant for DNA vaccination. PMID:24633335

  12. Immunogenicity of a plasmid DNA vaccine encoding 42kDa fragment of Plasmodium vivax merozoite surface protein-1.

    PubMed

    Sheikh, Inayat Hussain; Kaushal, Deep C; Chandra, Deepak; Kaushal, Nuzhat A

    2016-10-01

    Plasmodium vivax is the second major human malaria parasite that inflicts debilitating morbidity and consequent economic impact in South-East Asian countries. The relapsing nature of P. vivax along with the emergence of drug-resistant P. vivax strains has emphasized the urgent need for a vaccine. However, the development of an effective vivax vaccine is seriously hampered due to the diversity and variation in parasite antigens and non-availability of suitable animal models. DNA based vaccines represent an alternative approach in inducing immunity to multiple targets from different stages of malaria parasite. DNA prime-boosting strategies induce both antibody mediated and cell-mediated immune responses that are the major mechanisms of protection against malaria parasites. We have earlier studied the immunogenicity and protective efficacy of the soluble and refolded forms of recombinant 42kDa fragment of Plasmodium vivax merozoite surface protein-1 (PvMSP-142) using P. cynomolgi rhesus monkey model. In the present study, we have constructed a recombinant DNA vaccine encoding 42kDa fragment of P. vivax MSP-1 and studied the immunogenicity of PvMSP-142 DNA vaccine construct in mice. The 42kDa gene fragment of PvMSP-1 was PCR amplified using gene specific primers and subcloned into pcDNA 3.1 (+) eukaryotic expression vector. In vitro expression of PvMSP-142 plasmid construct was checked by transfection in COS-1 cell line. Indirect immunofluorescence of transfected COS-1 cells probed with monoclonal antibodies against PvMSP-142 exhibited positive fluorescence. Immunization of BALB/c mice with PvMSP-142-pcDNA vaccine construct revealed the immunogenicity of recombinant vaccine plasmid that can be enhanced by prime boosting with recombinant protein corresponding to the DNA vaccine as evidenced by significant elevation of antibody and the cytokines responses. PMID:27311385

  13. Influenza A virus hemagglutinin protein subunit vaccine elicits vaccine-associated enhanced respiratory disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vaccine-associated enhanced respiratory disease (VAERD) can occur when pigs are challenged with heterologous virus in the presence of non-neutralizing but cross-reactive antibodies elicited by whole inactivated virus (WIV) vaccine. The aim of this study was to compare the effects of heterologous del...

  14. Chemokine-adjuvanted electroporated DNA vaccine induces substantial protection from simian immunodeficiency virus vaginal challenge.

    PubMed

    Kutzler, M A; Wise, M C; Hutnick, N A; Moldoveanu, Z; Hunter, M; Reuter, M A; Yuan, S; Yan, J; Ginsberg, A A; Sylvester, A; Pahar, B; Carnathan, D G; Kathuria, N; Khan, A S; Montefiori, D; Sardesai, N Y; Betts, M R; Mestecky, J; Marx, P A; Weiner, D B

    2016-01-01

    There have been encouraging results for the development of an effective HIV vaccine. However, many questions remain regarding the quality of immune responses and the role of mucosal antibodies. We addressed some of these issues by using a simian immunodeficiency virus (SIV) DNA vaccine adjuvanted with plasmid-expressed mucosal chemokines combined with an intravaginal SIV challenge in rhesus macaque (RhM) model. We previously reported on the ability of CCR9 and CCR10 ligand (L) adjuvants to enhance mucosal and systemic IgA and IgG responses in small animals. In this study, RhMs were intramuscularly immunized five times with either DNA or DNA plus chemokine adjuvant delivered by electroporation followed by challenge with SIVsmE660. Sixty-eight percent of all vaccinated animals (P<0.01) remained either uninfected or had aborted infection compared with only 14% in the vaccine naïve group. The highest protection was observed in the CCR10L chemokines group, where six of nine animals had aborted infection and two remained uninfected, leading to 89% protection (P<0.001). The induction of mucosal SIV-specific antibodies and neutralization titers correlated with trends in protection. These results indicate the need to further investigate the contribution of chemokine adjuvants to modulate immune responses and the role of mucosal antibodies in SIV/HIV protection. PMID:25943275

  15. Chemokine Adjuvanted Electroporated-DNA Vaccine Induces Substantial Protection from Simian Immunodeficiency Virus Vaginal Challenge

    PubMed Central

    Hutnick, N A; Moldoveanu, Z; Hunter, M; Reuter, M; Yuan, S; Yan, J; Ginsberg, A; Sylvester, A; Pahar, B; Carnathan, D; Kathuria, N; Khan, A S; Montefiori, D; Sardesai, N Y; Betts, M R; Mestecky, J; Marx, P; Weiner, D B

    2015-01-01

    There have been encouraging results for the development of an effective HIV vaccine. However, many questions remain regarding the quality of immune responses and the role of mucosal antibodies. We addressed some of these issues by using a simian immunodeficiency virus (SIV) DNA vaccine adjuvanted with plasmid-expressed mucosal chemokines combined with an intravaginal SIV challenge in rhesus macaque (RhM) model. We previously reported on the ability of CCR9 and CCR10 ligand (L) adjuvants to enhance mucosal and systemic IgA and IgG in small animals. In this study, RhMs were intramuscularly immunized five times with either DNA or DNA plus chemokine adjuvant delivered by electroporation followed by challenge with SIVsmE660. Sixty-eight percent of all vaccinated animals (P=0.0016) remained either uninfected or had aborted infection compared to only 14% in the vaccine naïve group. The highest protection was observed in the CCR10L chemokines group, where 6 of 9 animals had aborted infection and two remained uninfected, leading to 89% protection (P=0.0003). The induction of mucosal SIV-specific antibodies and neutralization titers correlated with trends in protection. These results indicate the need to further investigate the contribution of chemokine adjuvants to modulate immune responses and the role of mucosal antibodies in SIV/HIV protection. PMID:25943275

  16. Transposon leads to contamination of clinical pDNA vaccine.

    PubMed

    van der Heijden, I; Gomez-Eerland, R; van den Berg, J H; Oosterhuis, K; Schumacher, T N; Haanen, J B A G; Beijnen, J H; Nuijen, B

    2013-07-11

    We report an unexpected contamination during clinical manufacture of a Human Papilomavirus (HPV) 16 E6 encoding plasmid DNA (pDNA) vaccine, with a transposon originating from the Escherichia coli DH5 host cell genome. During processing, presence of this transposable element, insertion sequence 2 (IS2) in the plasmid vector was not noticed until quality control of the bulk pDNA vaccine when results of restriction digestion, sequencing, and CGE analysis were clearly indicative for the presence of a contaminant. Due to the very low level of contamination, only an insert-specific PCR method was capable of tracing back the presence of the transposon in the source pDNA and master cell bank (MCB). Based on the presence of an uncontrolled contamination with unknown clinical relevance, the product was rejected for clinical use. In order to prevent costly rejection of clinical material, both in-process controls and quality control methods must be sensitive enough to detect such a contamination as early as possible, i.e. preferably during plasmid DNA source generation, MCB production and ultimately during upstream processing. However, as we have shown that contamination early in the process development pipeline (source pDNA, MCB) can be present below limits of detection of generally applied analytical methods, the introduction of "engineered" or transposon-free host cells seems the only 100% effective solution to avoid contamination with movable elements and should be considered when searching for a suitable host cell-vector combination. PMID:23707695

  17. Ag85A DNA Vaccine Delivery by Nanoparticles: Influence of the Formulation Characteristics on Immune Responses.

    PubMed

    Poecheim, Johanna; Barnier-Quer, Christophe; Collin, Nicolas; Borchard, Gerrit

    2016-01-01

    The influence of DNA vaccine formulations on immune responses in combination with adjuvants was investigated with the aim to increase cell-mediated immunity against plasmid DNA (pDNA) encoding Mycobacterium tuberculosis antigen 85A. Different ratios of pDNA with cationic trimethyl chitosan (TMC) nanoparticles were characterized for their morphology and physicochemical characteristics (size, zeta potential, loading efficiency and pDNA release profile) applied in vitro for cellular uptake studies and in vivo, to determine the dose-dependent effects of pDNA on immune responses. A selected pDNA/TMC nanoparticle formulation was optimized by the incorporation of muramyl dipeptide (MDP) as an immunostimulatory agent. Cellular uptake investigations in vitro showed saturation to a maximum level upon the increase in the pDNA/TMC nanoparticle ratio, correlating with increasing Th1-related antibody responses up to a definite pDNA dose applied. Moreover, TMC nanoparticles induced clear polarization towards a Th1 response, indicated by IgG2c/IgG1 ratios above unity and enhanced numbers of antigen-specific IFN-γ producing T-cells in the spleen. Remarkably, the incorporation of MDP in TMC nanoparticles provoked a significant additional increase in T-cell-mediated responses induced by pDNA. In conclusion, pDNA-loaded TMC nanoparticles are capable of provoking strong Th1-type cellular and humoral immune responses, with the potential to be further optimized by the incorporation of MDP. PMID:27626449

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

    PubMed

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

    2014-10-01

    To prevent the global spread of tuberculosis (TB), more effective vaccines and vaccination strategies are urgently needed. As a result of the success of bacillus Calmette-Guérin (BCG) in protecting children against miliary and meningeal TB, the majority of individuals will have been vaccinated with BCG; hence, boosting BCG-primed immunity will probably be a key component of future vaccine strategies. In this study, we compared the ability of DNA-, protein- and lentiviral vector-based vaccines that express the antigens Ag85B and Rv3425 to boost the effects of BCG in the context of immunity and protection against Mycobacterium tuberculosis in C57BL/6 mice. Our results demonstrated that prime-boost BCG vaccination with a lentiviral vector expressing the antigens Ag85B and Rv3425 significantly enhanced immune responses, including T helper type 1 and CD8(+) cytotoxic T lymphocyte responses, compared with DNA- and protein-based vaccines. However, lentivirus-vectored and DNA-based vaccines greatly improved the protective efficacy of BCG against M. tuberculosis, as indicated by a lack of weight loss and significantly reduced bacterial loads and histological damage in the lung. Our study suggests that the use of lentiviral or DNA vaccines containing the antigens Ag85B and Rv3425 to boost BCG is a good choice for the rational design of an efficient vaccination strategy against TB. PMID:24773322

  19. Mucosal DNA vaccination with highly attenuated Shigella is superior to attenuated Salmonella and comparable to intramuscular DNA vaccination for T cells against HIV.

    PubMed

    Vecino, William H; Morin, Paul M; Agha, Rabia; Jacobs, William R; Fennelly, Glenn J

    2002-07-01

    An immunization strategy using attenuated bacteria to deliver DNA vaccine plasmids to mucosal sites may induce protective T cell responses against sexual HIV transmission. In a murine intranasal (i.n.) immunization model, we demonstrate that transiently persistent Deltaasd Shigella flexneri strain 15D harboring DNA vaccines induces HIV- and SIV-specific gamma interferon (IFN-gamma) producing CD8+ T cells among splenocytes more efficiently than either a longer persisting DeltaaroD Salmonella typhimurium strain SL7207 or transiently persistent S. typhi strain Ty21a harboring DNA vaccines. Also, the frequency of antigen-specific gamma interferon (IFN-gamma) producing cells induced by Shigella 15D harboring a DNA vaccine were comparable to that induced by intramuscular (i.m.) immunization with purified DNA vaccine. Moreover, the magnitude of mucosal and systemic antigen-specific IgA and IgG responses after immunization were dependent upon the route (i.m. vs. i.n.) of inoculation, with i.n. Shigella 15D DNA vaccines generating higher levels of HIV-specific IgA in vaginal washings than i.m. purified DNA vaccine. Deltaasd S. flexneri is a promising vector for mucosal DNA vaccine immunization against HIV. PMID:12036602

  20. Novel and enhanced anti-melanoma DNA vaccine targeting the tyrosinase protein inhibits myeloid-derived suppressor cells and tumor growth in a syngeneic prophylactic and therapeutic murine model.

    PubMed

    Yan, J; Tingey, C; Lyde, R; Gorham, T C; Choo, D K; Muthumani, A; Myles, D; Weiner, L P; Kraynyak, K A; Reuschel, E L; Finkel, T H; Kim, J J; Sardesai, N Y; Ugen, K E; Muthumani, K; Weiner, D B

    2014-12-01

    Melanoma is the most deadly type of skin cancer, constituting annually ∼ 75% of all cutaneous cancer-related deaths due to metastatic spread. Currently, because of metastatic spread, there are no effective treatment options for late-stage metastatic melanoma patients. Studies over the past two decades have provided insight into several complex molecular mechanisms as to how these malignancies evade immunological control, indicating the importance of immune escape or suppression for tumor survival. Thus, it is essential to develop innovative cancer strategies and address immune obstacles with the goal of generating more effective immunotherapies. One important area of study is to further elucidate the role and significance of myeloid-derived suppressor cells (MDSCs) in the maintenance of the tumor microenvironment. These cells possess a remarkable ability to suppress immune responses and, as such, facilitate tumor growth. Thus, MDSCs represent an important new target for preventing tumor progression and escape from immune control. In this study, we investigated the role of MDSCs in immune suppression of T cells in an antigen-specific B16 melanoma murine system utilizing a novel synthetic tyrosinase (Tyr) DNA vaccine therapy in both prophylactic and therapeutic models. This Tyr vaccine induced a robust and broad immune response, including directing CD8 T-cell infiltration into tumor sites. The vaccine also reduced the number of MDSCs in the tumor microenvironment through the downregulation of monocyte chemoattractant protein 1, interleukin-10, CXCL5 and arginase II, factors important for MDSC expansion. This novel synthetic DNA vaccine significantly reduced the melanoma tumor burden and increased survival in vivo, due likely, in part, to the facilitation of a change in the tumor microenvironment through MDSC suppression. PMID:25394503

  1. Novel synthetic plasmid and Doggybone™ DNA vaccines induce neutralizing antibodies and provide protection from lethal influenza challenge in mice

    PubMed Central

    Scott, Veronica L; Patel, Ami; Villarreal, Daniel O; Hensley, Scott E; Ragwan, Edwin; Yan, Jian; Sardesai, Niranjan Y; Rothwell, Paul J; Extance, Jonathan P; Caproni, Lisa J; Weiner, David B

    2015-01-01

    Nucleic acid-based vaccines (NAVs) are a promising alternative to conventional influenza vaccines with the potential to increase influenza vaccine availability due to their simplicity in design and rapid speed of production. NAVs can also target multiple influenza antigens and control flu variants. Traditionally NAVs have been DNA plasmids however, we are continuing to explore new methods that may enhance vaccine efficacy. Recently new focus has been on RNA cassettes as NAVs. RNA vaccines combine conceptual advantages in that they focus on delivery of only the coding cassette. However, RNA vaccines have a short half-life and cause interferon-induced fevers. Here we describe a new NAV approach where we study delivery of a linear DNA cassette [Doggybone™ linear closed DNA [(dbDNA™)] produced by an enzymatic process that yields an antigen expression cassette comprising a promoter, DNA antigen, poly A tail, and telomeric ends. This focused approach has many of the advantages of plasmid DNA as well as a minimal cassette size similar to RNA strategies. For this study, we characterized the specific CD4+ and CD8+ T cell responses and determined the hemagglutination inhibition (HI) titers induced by dbDNA™ and compared the responses with those of an optimized plasmid DNA (pDNA) vaccine encoding the same H1N1 influenza A/PR/8/34 HA gene. Immunizations with the constructs resulted in similar humoral and cellular immune responses. Both constructs induced high-titer HI antibodies and fully protected animals from lethal viral challenge. The data obtained from this study provides important validation for further development of novel vector approaches. PMID:26091432

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  3. Delivery strategies to enhance oral vaccination against enteric infections.

    PubMed

    Davitt, Christopher J H; Lavelle, Ed C

    2015-08-30

    While the majority of human pathogens infect the body through mucosal sites, most licensed vaccines are injectable. In fact the only mucosal vaccine that has been widely used globally for infant and childhood vaccination programs is the oral polio vaccine (OPV) developed by Albert Sabin in the 1950s. While oral vaccines against Cholera, rotavirus and Salmonella typhi have also been licensed, the development of additional non-living oral vaccines against these and other enteric pathogens has been slow and challenging. Mucosal vaccines can elicit protective immunity at the gut mucosa, in part via antigen-specific secretory immunoglobulin A (SIgA). However, despite their advantages over the injectable route, oral vaccines face many hurdles. A key challenge lies in design of delivery strategies that can protect antigens from degradation in the stomach and intestine, incorporate appropriate immune-stimulatory adjuvants and control release at the appropriate gastrointestinal site. A number of systems including micro and nanoparticles, lipid-based strategies and enteric capsules have significant potential either alone or in advanced combined formulations to enhance intestinal immune responses. In this review we will outline the opportunities, challenges and potential delivery solutions to facilitate the development of improved oral vaccines for infectious enteric diseases. PMID:25817337

  4. Pulsed ultrasound for enhancing vaccine production.

    PubMed

    Xing, Jida; Hu, Chenxia; Ma, Allan; George, Rajan; Xing, James Z; Chen, Jie

    2015-08-01

    Hepatitis B is an infectious liver disease and vaccination is an effective way to protect individuals. We have applied mechanical wave stimulation to increase protein production. To validate our design, we used Sf9 insect cells to increase antigen fragment fusion protein expression for hepatitis B virus (HBV S1/S2). We discovered that stimulation at a frequency of 1.5 MHz, intensity of 60 mW/cm(2), for a duration of 10 minutes per day increased HBV S1/S2 production by 15%. This finding is very significant for shortening vaccine production time or increasing the yield of proteins for use as vaccines. PMID:26736715

  5. Clinical development of intramuscular electroporation: providing a "boost" for DNA vaccines.

    PubMed

    Khan, Amir S; Broderick, Kate E; Sardesai, Niranjan Y

    2014-01-01

    The development of effective vaccines has helped to eradicate or control the spread of numerous infectious diseases. However, there are many more diseases that have proved more difficult to eliminate using conventional vaccines. The recent innovation of DNA vaccines may provide a "boost" to the development efforts. While the early efforts of DNA vaccines in the clinic were disappointing, the use of in vivo electroporation has helped to provide some basis for optimism. Now, there are several ongoing clinical studies of vaccines against such diseases as malaria, HIV, hepatitis C, and even various types of cancer. This review will highlight three recently published clinical studies using intramuscular DNA administration with electroporation. PMID:24510832

  6. Immunogenicity and efficacy of a plasmid DNA rabies vaccine incorporating Myd88 as a genetic adjuvant

    PubMed Central

    Ullas, Padinjaremattathil Thankappan; Desai, Anita

    2014-01-01

    Purpose Myeloid differentiation factor 88 (Myd88), a ubiquitous Toll-like receptor adaptor molecule, has been reported to play important roles in B cell responses to infections and vaccination. The present study evaluated the effects of genetic adjuvanting with Myd88 on the immune responses to a plasmid DNA rabies vaccine. Materials and Methods Plasmids encoding rabies glycoprotein alone (pIRES-Rgp) or a fragment of Myd88 gene in addition (pIRES-Rgp-Myd) were constructed and administered intramuscularly or intrademally in Swiss albino mice (on days 0, 7, and 21). Rabies virus neutralizing antibody (RVNA) titres were estimated in the mice sera on days 14 and 28 by rapid fluorescent focus inhibition test. The protective efficacy of the constructs was evaluated by an intracerebral challenge with challenge virus standard virus on day 35. Results Co-expression of Myd88 increased RVNA responses to pIRES-Rgp by 3- and 2-folds, following intramuscular and intradermal immunization, respectively. pIRES-Rgp protected 80% of the mice following intramuscular and intradermal immunizations, while pIRES-Rgp-Myd afforded 100% protection following similar administrations. Conclusion Genetic adjuvanting with Myd88 enhanced the RVNA responses and protective efficacy of a plasmid DNA rabies vaccine. This strategy might be useful for rabies vaccination of canines in the field, and needs further evaluation. PMID:25003094

  7. Imperfect Vaccination Can Enhance the Transmission of Highly Virulent Pathogens

    PubMed Central

    Read, Andrew F.; Baigent, Susan J.; Powers, Claire; Kgosana, Lydia B.; Blackwell, Luke; Smith, Lorraine P.; Kennedy, David A.; Walkden-Brown, Stephen W.; Nair, Venugopal K.

    2015-01-01

    Could some vaccines drive the evolution of more virulent pathogens? Conventional wisdom is that natural selection will remove highly lethal pathogens if host death greatly reduces transmission. Vaccines that keep hosts alive but still allow transmission could thus allow very virulent strains to circulate in a population. Here we show experimentally that immunization of chickens against Marek's disease virus enhances the fitness of more virulent strains, making it possible for hyperpathogenic strains to transmit. Immunity elicited by direct vaccination or by maternal vaccination prolongs host survival but does not prevent infection, viral replication or transmission, thus extending the infectious periods of strains otherwise too lethal to persist. Our data show that anti-disease vaccines that do not prevent transmission can create conditions that promote the emergence of pathogen strains that cause more severe disease in unvaccinated hosts. PMID:26214839

  8. Therapy of tuberculosis in mice by DNA vaccination.

    PubMed

    Lowrie, D B; Tascon, R E; Bonato, V L; Lima, V M; Faccioli, L H; Stavropoulos, E; Colston, M J; Hewinson, R G; Moelling, K; Silva, C L

    1999-07-15

    Mycobacterium tuberculosis continues to kill about 3 million people every year, more than any other single infectious agent. This is attributed primarily to an inadequate immune response towards infecting bacteria, which suffer growth inhibition rather than death and subsequently multiply catastrophically. Although the bacillus Calmette-Guerin (BCG) vaccine is widely used, it has major limitations as a preventative measure. In addition, effective treatment requires that patients take large doses of antibacterial drug combinations for at least 6 months after diagnosis, which is difficult to achieve in many parts of the world and is further restricted by the emergence of multidrug-resistant strains of M. tuberculosis. In these circumstances, immunotherapy to boost the efficiency of the immune system in infected patients could be a valuable adjunct to antibacterial chemotherapy. Here we show in mice that DNA vaccines, initially designed to prevent infection, can also have a pronounced therapeutic action. In heavily infected mice, DNA vaccinations can switch the immune response from one that is relatively inefficient and gives bacterial stasis to one that kills bacteria. Application of such immunotherapy in conjunction with conventional chemotherapeutic antibacterial drugs might result in faster or more certain cure of the disease in humans. PMID:10421369

  9. Salmonella typhi Ty21a bacterial ghost vector augments HIV-1 gp140 DNA vaccine-induced peripheral and mucosal antibody responses via TLR4 pathway.

    PubMed

    Wen, Jing; Yang, Yi; Zhao, Guangyu; Tong, Shuang; Yu, Hong; Jin, Xia; Du, Lanying; Jiang, Shibo; Kou, Zhihua; Zhou, Yusen

    2012-08-24

    Because of their stability and ease of manipulation, DNA vaccines have considerable potential for eliciting immune responses. However, they are limited by their weak immunogenicity, especially in humans. To address this challenge, we explored a new strategy of HIV vaccine delivery using Salmonella typhi Ty21a bacterial ghosts (BGs). We found that Ty21a BGs loaded with an HIV gp140 DNA vaccine (Ty21a BG-DNA) were readily taken up by murine macrophage RAW264.7 cells, and gp140 was efficiently expressed in these cells. Peripheral and intestinal mucosal anti-gp120 antibody responses in mice vaccinated with BGs-DNA vaccine were significantly higher than those in mice immunized with naked DNA vaccine. The enhancement of antibody responses was associated with BG-induced production of IL-10 through TLR4 pathway. These results demonstrate that Ty21a BGs is a novel and effective delivery vehicle for DNA vaccines, which could therefore be used as a new strategy for development of HIV vaccines. PMID:22819719

  10. DNA vaccine protects ornamental koi (Cyprinus carpio koi) against North American spring viremia of carp virus

    USGS Publications Warehouse

    Emmenegger, E.J.; Kurath, G.

    2008-01-01

    The emergence of spring viremia of carp virus (SVCV) in the United States constitutes a potentially serious alien pathogen threat to susceptible fish stocks in North America. A DNA vaccine with an SVCV glycoprotein (G) gene from a North American isolate was constructed. In order to test the vaccine a challenge model utilizing a specific pathogen-free domestic koi stock and a cold water stress treatment was also developed. We have conducted four trial studies demonstrating that the pSGnc DNA vaccine provided protection in vaccinated fish against challenge at low, moderate, and high virus doses of the homologous virus. The protection was significant (p < 0.05) as compared to fish receiving a mock vaccine construct containing a luciferase reporter gene and to non-vaccinated controls in fish ranging in age from 3 to 14 months. In all trials, the SVCV-G DNA immunized fish were challenged 28-days post-vaccination (546 degree-days) and experienced low mortalities varying from 10 to 50% with relative percent survivals ranging from 50 to 88%. The non-vaccinated controls and mock construct vaccinated fish encountered high cumulative percent mortalities ranging from 70 to 100%. This is the first report of a SVCV DNA vaccine being tested successfully in koi. These experiments prove that the SVCV DNA (pSGnc) vaccine can elicit specific reproducible protection and validates its potential use as a prophylactic vaccine in koi and other vulnerable North American fish stocks.

  11. Adjuvant effects of interleukin-18 in DNA vaccination against infectious bursal disease virus in chickens.

    PubMed

    Li, Kai; Gao, Honglei; Gao, Li; Qi, Xiaole; Gao, Yulong; Qin, Liting; Wang, Yongqiang; Wang, Xiaomei

    2013-04-01

    Interleukin-18 (IL-18) is an important cytokine with multiple functions in innate and acquired immunity. In this study, chicken IL-18 was evaluated for its adjuvant effects on the protective immunity of a DNA vaccine carrying the VP243 gene of IBDV. Groups of 14-day-old SPF chickens were given twice at 2-week intervals with 100 μg of the plasmid DNA vaccine pCAGVP243, pCAGVP243-IL-18 and the blank vector pCAGGS, respectively, and challenged with vvIBDV (HLJ0504 strain) 2 weeks later. Chickens immunized with plasmid pCAGVP243-IL-18 carrying both VP243 and IL-18 genes induced significantly higher levels of antibodies, lymphocyte proliferation responses and of the cytokines IL-4 and IFN-γ than those injected with pCAGVP243 encoding the VP243 gene alone. Furthermore, pCAGVP243-IL-18 provided higher protection (93%) against vvIBDV challenge in chickens than pCAGVP243 (60%), as evidenced by the absence of clinical signs, mortality, and bursal atrophy. These results indicated that the cytokine IL-18 could enhance the immune responses and protection efficacy of DNA vaccine against IBDV infection in chickens, highlighting the potential value of chicken IL-18 as an adjuvant in the prevention of vvIBDV infection. PMID:23395585

  12. Enhancing dendritic cell activation and HIV vaccine effectiveness through nanoparticle vaccination.

    PubMed

    Glass, Joshua J; Kent, Stephen J; De Rose, Robert

    2016-06-01

    Novel vaccination approaches are needed to prevent and control human immunodeficiency virus (HIV) infection. A growing body of literature demonstrates the potential of nanotechnology to modulate the human immune system and generate targeted, controlled immune responses. In this Review, we summarize important advances in how 'nanovaccinology' can be used to develop safe and effective vaccines for HIV. We highlight the central role of dendritic cells in the immune response to vaccination and describe how nanotechnology can be used to enhance delivery to and activation of these important antigen-presenting cells. Strategies employed to improve biodistribution are discussed, including improved lymph node delivery and mucosal penetration concepts, before detailing methods to enhance the humoral and/or cellular immune response to vaccines. We conclude with a commentary on the current state of nanovaccinology. PMID:26783186

  13. Detection of PCV-2 DNA in stool samples from infants vaccinated with RotaTeq®.

    PubMed

    Esona, Mathew D; Mijatovic-Rustempasic, Slavica; Yen, Catherine; Parashar, Umesh D; Gentsch, Jon R; Bowen, Michael D; LaRussa, Philip

    2014-01-01

    Rotarix® and RotaTeq® vaccines have led to a dramatic reduction in rotavirus disease worldwide. However, the detection of porcine circovirus type 1 (PCV-1) and 2 (PCV-2) DNA in these vaccines raised some safety concerns. Studies examining shedding of rotavirus in stool from rotavirus vaccine recipients have been performed but no published data exist regarding the shedding of PCV virus in stools of vaccinees. The goal of this study was to determine if PCV-1 and/or PCV-2 is shed in the feces of infants vaccinated with RotaTeq®. Using multiple PCR assays for detection of PCV DNA, we tested for PCV-1 and PCV-2 in 826 stool swab samples collected serially during the first 9 d after vaccination from 102 children vaccinated with RotaTeq®. Since the vaccine is recommended and uptake is high, we did not have samples from unvaccinated infants. A total of 235 (28.5%) samples from 59 vaccine recipients were positive for PCV-2 DNA by one or more assays used in this study. PCV-1 DNA was not detected in RotaTeq® or any of the stool swab extracts. Twenty-two of the 102 vaccine recipients (21.6%) shed RotaTeq® vaccine strain and 10 of these vaccinees (9.8%) were shedding both PCV DNA and rotavirus vaccine RNA. PCV DNA was detected up to 9 d post vaccination and was most frequently detected in the first 5 d after vaccination. This study demonstrated shedding of PCV-2 DNA by RotaTeq® vaccinees but we did not find evidence that this DNA was associated with viable PCV. Findings from this study support the continued use of current rotavirus vaccines. PMID:24104203

  14. Detection of PCV-2 DNA in stool samples from infants vaccinated with RotaTeq®

    PubMed Central

    Esona, Mathew D; Mijatovic-Rustempasic, Slavica; Yen, Catherine; Parashar, Umesh D; Gentsch, Jon R; Bowen, Michael D; LaRussa, Philip

    2014-01-01

    Rotarix® and RotaTeq® vaccines have led to a dramatic reduction in rotavirus disease worldwide. However, the detection of porcine circovirus type 1 (PCV-1) and 2 (PCV-2) DNA in these vaccines raised some safety concerns. Studies examining shedding of rotavirus in stool from rotavirus vaccine recipients have been performed but no published data exist regarding the shedding of PCV virus in stools of vaccinees. The goal of this study was to determine if PCV-1 and/or PCV-2 is shed in the feces of infants vaccinated with RotaTeq®. Using multiple PCR assays for detection of PCV DNA, we tested for PCV-1 and PCV-2 in 826 stool swab samples collected serially during the first 9 d after vaccination from 102 children vaccinated with RotaTeq®. Since the vaccine is recommended and uptake is high, we did not have samples from unvaccinated infants. A total of 235 (28.5%) samples from 59 vaccine recipients were positive for PCV-2 DNA by one or more assays used in this study. PCV-1 DNA was not detected in RotaTeq® or any of the stool swab extracts. Twenty-two of the 102 vaccine recipients (21.6%) shed RotaTeq® vaccine strain and 10 of these vaccinees (9.8%) were shedding both PCV DNA and rotavirus vaccine RNA. PCV DNA was detected up to 9 d post vaccination and was most frequently detected in the first 5 d after vaccination. This study demonstrated shedding of PCV-2 DNA by RotaTeq® vaccinees but we did not find evidence that this DNA was associated with viable PCV. Findings from this study support the continued use of current rotavirus vaccines. PMID:24104203

  15. Therapeutic DNA vaccination against colorectal cancer by targeting the MYB oncoprotein.

    PubMed

    Cross, Ryan S; Malaterre, Jordane; Davenport, Alexander J; Carpinteri, Sandra; Anderson, Robin L; Darcy, Phillip K; Ramsay, Robert G

    2015-01-01

    Cancers can be addicted to continued and relatively high expression of nuclear oncoproteins. This is evident in colorectal cancer (CRC) where the oncoprotein and transcription factor MYB is over expressed and essential to continued proliferation and tumour cell survival. Historically, targeting transcription factors in the context of cancer has been very challenging. Nevertheless, we formulated a DNA vaccine to generate a MYB-specific immune response in the belief MYB peptides might be aberrantly presented on the cell surface of CRC cells. MYB, like many tumour antigens, is weakly immunogenic as it is a 'self' antigen and is subject to tolerance. To break tolerance, a fusion vaccine was generated comprising a full-length MYB complementary DNA (cDNA) flanked by two potent CD4-epitopes derived from tetanus toxoid. Vaccination was achieved against tumours initiated by two distinct highly aggressive, syngeneic cancer cell lines (CT26 and MC38) that express MYB. This was done in BALB/c and C57BL/6 mouse strains respectively. We introduced multiple inactivating mutations into the oncogene sequence for safety and sub-cloned the cDNA into a Food and Drug Administration (FDA)-compliant vector. We used low dose cyclophosphamide (CY) to overcome T-regulatory cell immune suppression, and anti-program cell death receptor 1 (anti-PD-1) antibodies to block T-cell exhaustion. Anti-PD-1 administered alone slightly delayed tumour growth in MC38 and more effectively in CT26 bearing mice, while CY treatment alone did not. We found that therapeutic vaccination elicits protection when MC38 tumour burden is low, mounts tumour-specific cell killing and affords enhanced protection when MC38 and CT26 tumour burden is higher but only in combination with anti-PD-1 antibody or low dose CY, respectively. PMID:25671128

  16. Therapeutic DNA vaccination against colorectal cancer by targeting the MYB oncoprotein

    PubMed Central

    Cross, Ryan S; Malaterre, Jordane; Davenport, Alexander J; Carpinteri, Sandra; Anderson, Robin L; Darcy, Phillip K; Ramsay, Robert G

    2015-01-01

    Cancers can be addicted to continued and relatively high expression of nuclear oncoproteins. This is evident in colorectal cancer (CRC) where the oncoprotein and transcription factor MYB is over expressed and essential to continued proliferation and tumour cell survival. Historically, targeting transcription factors in the context of cancer has been very challenging. Nevertheless, we formulated a DNA vaccine to generate a MYB-specific immune response in the belief MYB peptides might be aberrantly presented on the cell surface of CRC cells. MYB, like many tumour antigens, is weakly immunogenic as it is a ‘self' antigen and is subject to tolerance. To break tolerance, a fusion vaccine was generated comprising a full-length MYB complementary DNA (cDNA) flanked by two potent CD4-epitopes derived from tetanus toxoid. Vaccination was achieved against tumours initiated by two distinct highly aggressive, syngeneic cancer cell lines (CT26 and MC38) that express MYB. This was done in BALB/c and C57BL/6 mouse strains respectively. We introduced multiple inactivating mutations into the oncogene sequence for safety and sub-cloned the cDNA into a Food and Drug Administration (FDA)-compliant vector. We used low dose cyclophosphamide (CY) to overcome T-regulatory cell immune suppression, and anti-program cell death receptor 1 (anti-PD-1) antibodies to block T-cell exhaustion. Anti-PD-1 administered alone slightly delayed tumour growth in MC38 and more effectively in CT26 bearing mice, while CY treatment alone did not. We found that therapeutic vaccination elicits protection when MC38 tumour burden is low, mounts tumour-specific cell killing and affords enhanced protection when MC38 and CT26 tumour burden is higher but only in combination with anti-PD-1 antibody or low dose CY, respectively. PMID:25671128

  17. Clinical experience with a recombinant DNA hepatitis B vaccine.

    PubMed

    Andre, F E

    1988-09-01

    The clinical testing of EngerixR-B, the hepatitis B vaccine produced by SmithKline Biologicals using recombinant DNA technology, started in February 1984. Since extensive pre-clinical laboratory work had established that the polypeptide (HBsAg) expressed in genetically engineered yeast cells was after purification--physically, chemically and antigenically similar to the viral surface antigen particles found in the blood of chronic carriers, the aims of the clinical trials were to compare the safety, reactogenicity, immunogenicity and protective efficacy of yeast-derived (YDV) and plasma-derived (PDV) vaccines. By September 1987, 89 studies had been initiated involving a total of 10,545 subjects aged from birth to 82 years. This extensive experience has established that the risk of hypersensitivity to yeast-derived contaminants is negligible since no hypersensitivity reaction has been observed in any vaccinee, the incidence and severity of local reactions have not increased after repeated inoculations and no anti-yeast antibodies were produced by vaccination. Reactogenicity has been comparable to that of PDV's consisting essentially of transient mild irritation at the site of injection presumably caused by the aluminium hydroxide used as adjuvant. The anti-HBs responses to YDV and PDV's were quantitatively (seroconversion rates, peak antibody levels and persistence) as well as qualitatively (epitope specificity and affinity) similar. The expected protective effect of the immune response to the vaccine was confirmed in a challenge study in chimpanzees and in vaccinated human populations (male homosexuals, institutionalized mentally retarded patients, neonates of carrier women) with historically a high infection rate. PMID:2464196

  18. Increased immunogenicity of avian influenza DNA vaccine delivered to the skin using a microneedle patch

    PubMed Central

    Kim, Yeu-Chun; Song, Jae-Min; Lipatov, Aleksandr S.; Choi, Seong-O; Lee, Jeong Woo; Donis, Ruben O.; Compans, Richard W.; Kang, Sang-Moo; Prausnitz, Mark R.

    2012-01-01

    Effective public health responses to an influenza pandemic require an effective vaccine that can be manufactured and administered to large populations in the shortest possible time. In this study, we evaluated a method for vaccination against avian influenza virus that uses a DNA vaccine for rapid manufacturing and delivered by a microneedle skin patch for simplified administration and increased immunogenicity. We prepared patches containing 700 µm-long microneedles coated with an avian H5 influenza hemagglutinin DNA vaccine from A/Viet Nam/1203/04 influenza virus. The coating DNA dose increased with DNA concentration in the coating solution and the number of dip coating cycles. Coated DNA was released into the skin tissue by dissolution within minutes. Vaccination of mice using microneedles induced higher levels of antibody responses and hemagglutination inhibition titers, and improved protection against lethal infection with avian influenza as compared to conventional intramuscular delivery of the same dose of the DNA vaccine. Additional analysis showed that the microneedle coating solution containing carboxymethylcellulose and a surfactant may have negatively affected the immunogenicity of the DNA vaccine. Overall, this study shows that DNA vaccine delivery by microneedles can be a promising approach for improved vaccination to mitigate an influenza pandemic. PMID:22504442

  19. Virus-Like Particle Secretion and Genotype-Dependent Immunogenicity of Dengue Virus Serotype 2 DNA Vaccine

    PubMed Central

    Galula, Jedhan U.; Shen, Wen-Fan; Chuang, Shih-Te

    2014-01-01

    candidates were evaluated for their immunogenicity, homologous and heterologous neutralizing (Nt) antibody titers, and cross-genotype protection in a murine model. The immunity elicited by our prototype vaccine candidate (Asian 1 genotype strain 16681) in mice was protective against viruses of other genotypes but not against virus of the Sylvatic genotype, whose emergence and potential risk after introduction into the human population have previously been demonstrated. The underlying mechanism of a lack of protection elicited by the prototype vaccine may at least be contributed by the absence of a flavivirus subgroup-cross-reactive, highly neutralizing monoclonal antibody 1B7-5-like epitope in DENV-2 of the Sylvatic genotype. The DENV DNA vaccine directs the synthesis and assembly of virus-like particles (VLPs) and induces immune responses similar to those elicited by live-attenuated vaccines, and its flexibility permits the fast deployment of vaccine to combat emerging viruses, such as Sylvatic genotype viruses. The enhanced VLP secretion obtained by replacement of ectodomain I-II (EDI-II) of the Cosmopolitan genotype vaccine construct (VD2-Cosmopolitan) with the Asian 1 EDI-II elicited significantly higher total IgG and Nt antibody titers and suggests a novel approach to enhance the immunogenicity of the DNA vaccine. A DENV vaccine capable of eliciting protective immunity against viruses of existing and emerging genotypes should be the focus of future DENV vaccine development. PMID:25008922

  20. Dose-dependent inhibition of Gag cellular immunity by Env in SIV/HIV DNA vaccinated macaques

    PubMed Central

    Valentin, Antonio; Li, Jinyao; Rosati, Margherita; Kulkarni, Viraj; Patel, Vainav; Jalah, Rashmi; Alicea, Candido; Reed, Steven; Sardesai, Niranjan; Berkower, Ira; Pavlakis, George N; Felber, Barbara K

    2015-01-01

    The induction of a balanced immune response targeting the major structural proteins, Gag and Env of HIV, is important for the development of an efficacious vaccine. The use of DNA plasmids expressing different antigens offers the opportunity to test in a controlled manner the influence of different vaccine components on the magnitude and distribution of the vaccine-induced cellular and humoral immune responses. Here, we show that increasing amounts of env DNA results in greatly enhanced Env antibody titers without significantly affecting the levels of anti-Env cellular immune responses. Co-immunization with Env protein further increased antibody levels, indicating that vaccination with DNA only is not sufficient for eliciting maximal humoral responses against Env. In contrast, under high env:gag DNA plasmid ratio, the development of Gag cellular responses was significantly reduced by either SIV or HIV Env, whereas Gag humoral responses were not affected. Our data indicate that a balanced ratio of the 2 key HIV/SIV vaccine components, Gag and Env, is important to avoid immunological interference and to achieve both maximal humoral responses against Env to prevent virus acquisition and maximal cytotoxic T cell responses against Gag to prevent virus spread. PMID:26125521

  1. DNA vaccine against visceral leishmaniasis: a promising approach for prevention and control.

    PubMed

    Kumar, A; Samant, M

    2016-05-01

    The visceral leishmaniasis (VL) caused by Leishmania donovani parasite severely affects large populations in tropical and subtropical regions of the world. The arsenal of drugs available is limited, and resistance is common in clinical field isolates. Therefore, vaccines could be an important alternative for prevention against VL. Recently, some investigators advocated the protective efficacy of DNA vaccines, which induces the T cell-based immunity against VL. The vaccine antigens are selected as conserved in various Leishmania species and provide a viable strategy for DNA vaccine development. Our understanding for DNA vaccine development against VL is not enough and much technological advancement is required. Improved formulations and methods of delivery are required, which increase the uptake of DNA vaccine by cells; optimization of vaccine vectors/encoded antigens to augment and direct the host immune response in VL. Despite the many genes identified as vaccine candidates, the disappointing potency of the DNA vaccines in VL underscores the challenges encountered in the efforts to translate efficacy in preclinical models into clinical realities. This review will provide a brief background of DNA vaccines including the insights gained about the design, strategy, safety issues, varied candidates, progress and challenges that play a role in their ability against VL. PMID:27009772

  2. Laboratory and field evaluation of Schistosoma japonicum DNA vaccines in sheep and water buffalo in China.

    PubMed

    Shi, F; Zhang, Y; Ye, P; Lin, J; Cai, Y; Shen, W; Bickle, Q D; Taylor, M G

    2001-11-12

    Vaccines are needed to control zoonotic Schistosoma japonicum infection and several vaccine candidates have now been identified. Two of these (Sj28GST and Sj23) have shown particular promise in sheep when injected with Freund's adjuvants. The objective of the present work was to find a vaccine formulation which may have potential for widespread use in the field. DNA vaccine formulations of these antigens were produced and tested first in sheep under laboratory conditions and then in both the laboratory and the field in water buffalo. In both host species partial protection as evidenced by a reduction in parasite counts in vaccinated compared with control animals was induced by both vaccines, and in water buffalo the vaccines were shown to be partially protective in the field as well as in the laboratory. These results suggest that the two DNA vaccines tested here may have potential for large-scale field use. PMID:11672910

  3. DNA-based influenza vaccines: evaluating their potential to provide universal protection.

    PubMed

    Choo, Andrew Y; Broderick, Kate E; Kim, Joseph J; Sardesai, Niranjan Y

    2010-10-01

    The recent outbreaks of the H5N1 and H1N1 pandemic influenza have highlighted the importance of developing fast, effective therapeutic strategies to prevent and/or limit the spread of future influenza outbreaks. Although current vaccines against influenza are generally effective, several limitations, including those associated with the amount of available vaccine, the time to vaccine production and vaccine efficacy, may encumber a mass vaccination strategy and effective targeting against future outbreaks. This feature review discusses the prospects of SynCon-derived DNA vaccines against influenza; such vaccines are expected to be effective at targeting many currently circulating influenza virus strains, as well as potentially targeting strains that may be associated with future outbreaks. Because of advantages associated with safety, time to production and ease of production, as well as the generation of more effective immune responses, influenza DNA vaccines provide a promising potential solution to a global medical concern. PMID:20878593

  4. Influenza A virus hemagglutinin protein subunit vaccine elicits vaccine-associated enhanced respiratory disease in pigs.

    PubMed

    Rajão, Daniela S; Loving, Crystal L; Gauger, Phillip C; Kitikoon, Pravina; Vincent, Amy L

    2014-09-01

    Vaccine-associated enhanced respiratory disease (VAERD) can occur when pigs are challenged with heterologous virus in the presence of non-neutralizing but cross-reactive antibodies elicited by whole inactivated virus (WIV) vaccine. The aim of this study was to compare the effects of heterologous δ1-H1N2 influenza A virus (IAV) challenge of pigs after vaccination with 2009 pandemic H1N1 virus (H1N1pdm09) recombinant hemagglutinin (HA) subunit vaccine (HA-SV) or temperature-sensitive live attenuated influenza virus (LAIV) vaccine, and to assess the role of immunity to HA in the development of VAERD. Both HA-SV and LAIV vaccines induced high neutralizing antibodies to virus with homologous HA (H1N1pdm09), but not heterologous challenge virus (δ1-H1N2). LAIV partially protected pigs, resulting in reduced virus shedding and faster viral clearance, as no virus was detected in the lungs by 5 days post infection (dpi). HA-SV vaccinated pigs developed more severe lung and tracheal lesions consistent with VAERD following challenge. These results demonstrate that the immune response against the HA protein alone is sufficient to cause VAERD following heterologous challenge. PMID:25077416

  5. Protocols for Developing Novel Chikungunya Virus DNA Vaccines.

    PubMed

    Chung, Christopher; Ugen, Kenneth E; Sardesai, Niranjan Y; Weiner, David B; Muthumani, Kar

    2016-01-01

    To date, there have been several million infections by the Chikungunya virus (CHIKV), a mosquito-transmitted emerging pathogen that is considered to be taxonomically an Old World RNA virus. Although original CHIKV outbreaks were restricted to India, East Asian countries, Northern Italy, and France, a recent sharp rise had been identified in 41 countries or territories in the Caribbean, Central America, South America, and North America. A total of 1,012,347 suspected and 22,579 laboratory-confirmed CHIKV cases have been reported from these areas, which signals an increasing risk to the US mainland. Unlike past epidemics that were usually associated with Ae. aegypti transmission, the Caribbean outbreak was associated with Ae. albopictus transmission as the principal mosquito vector. In addition, the substantial increase in the number of deaths during this epidemic, as well as incidence of neurologic disease, suggests that CHIKV may have become more virulent. Currently, there are no licensed vaccines or therapeutics available for CHIKV or its associated disease pathologies. Therefore, development of new vaccines and therapies that could confer immunity and/or treat clinical symptoms of CHIKV is greatly desired. This chapter describes the use of entirely cutting edge technologies/methodologies developed by our group for the development and evaluation of novel DNA vaccines against CHIKV. PMID:27233283

  6. Preclinical evaluation of the immunogenicity and safety of plasmid DNA-based prophylactic vaccines for human cytomegalovirus

    PubMed Central

    Hartikka, Jukka; Bozoukova, Vesselina; Morrow, Jane; Rusalov, Denis; Shlapobersky, Mark; Wei, Qun; Boutsaboualoy, Sou; Ye, Ming; Wloch, Mary K.; Doukas, John; Sullivan, Sean; Rolland, Alain; Smith, Larry R.

    2012-01-01

    Human cytomegalovirus (CMV) establishes a lifelong persistent infection characterized by periods of latency and sporadic viral replication and is a major infectious cause of birth defects following congenital infection. Currently, no licensed vaccine is available that would prevent CMV infection. In an effort to develop a prophylactic CMV vaccine, the effects of different formulations, immunization routes and delivery devices on the immunogenicity of plasmid DNA (pDNA)-based vaccines were evaluated in rabbits and mice. Compared with PBS- and poloxamer-based formulations, significantly higher antibody responses were obtained with pDNA formulated with Vaxfectin®, a cationic lipid-based adjuvant. With low vaccine doses, the intradermal (ID) route resulted in higher antibody responses than obtained when the same dose was administered intramuscularly (IM). Since the IM route allowed injection of larger volumes and higher doses than could be administered at a single ID site, better antibody responses were obtained using the IM route. The needle-free injection system Biojector® 2000 and electroporation devices enhanced antibody responses only marginally compared with responses obtained with Vaxfectin®-formulated pDNA injected IM with a needle. A single-vial Vaxfectin® formulation was developed in a dosage form ready for use after thawing at room temperature. Finally, in a GLP-compliant repeat-dose toxicology study conducted in rabbits, single-vial Vaxfectin®-formulated vaccines, containing pDNA and Vaxfectin® up to 4.5 mg and 2 mg/injection, respectively, showed a favorable safety profile and were judged as well-tolerated. The results support further development of a Vaxfectin®-formulated pDNA vaccine to target congenital CMV infection. PMID:22922766

  7. Infectious bursal disease DNA vaccination conferring protection by delayed appearance and rapid clearance of invading viruses.

    PubMed

    Chen, Yung-Yi; Hsieh, Ming Kun; Tung, Chun-Yu; Wu, Ching Ching; Lin, Tsang Long

    2011-12-01

    The present study was undertaken to determine the kinetics of viral load and immune response in protection against infectious bursal disease virus (IBDV) by DNA vaccination. Chickens were DNA-vaccinated and challenged with IBDV one week after the third vaccination. Tissues were collected at 12 hours postinfection (HPI), 1 day postinfection (DPI), 3, 5, 7 and 10 DPI. The vaccinated chickens had less viral RNA, with delayed appearance and shorter duration in the bursa of Fabricius, spleen, and cecal tonsil than the challenged control chickens. Their ELISA and neutralizing antibody titers were decreased at 12 HPI and significantly lower (P < 0.05) than those in the challenged control chickens at later time points. Their spleen IFNγ expression was up-regulated compared to that in the DNA-vaccinated chickens without IBDV challenge. These results indicate that DNA vaccination confers protection against IBDV challenge by delayed appearance and rapid clearance of the invading viruses. PMID:21984266

  8. DNA Priming for Seasonal Influenza Vaccine: A Phase 1b Double-Blind Randomized Clinical Trial

    PubMed Central

    Ledgerwood, Julie E.; Bellamy, Abbie R.; Belshe, Robert; Bernstein, David I.; Edupuganti, Srilatha; Patel, Shital M.; Renehan, Phyllis; Zajdowicz, Thad; Schwartz, Richard; Koup, Richard; Bailer, Robert T.; Yamshchikov, Galina V.; Enama, Mary E.; Sarwar, Uzma; Larkin, Brenda; Graham, Barney S.

    2015-01-01

    Background The efficacy of current influenza vaccines is limited in vulnerable populations. DNA vaccines can be produced rapidly, and may offer a potential strategy to improve vaccine immunogenicity, indicated by studies with H5 influenza DNA vaccine prime followed by inactivated vaccine boost. Methods Four sites enrolled healthy adults, randomized to receive 2011/12 seasonal influenza DNA vaccine prime (n=65) or phosphate buffered saline (PBS) (n=66) administered intramuscularly with Biojector. All subjects received the 2012/13 seasonal inactivated influenza vaccine, trivalent (IIV3) 36 weeks after the priming injection. Vaccine safety and tolerability was the primary objective and measurement of antibody response by hemagglutination inhibition (HAI) was the secondary objective. Results The DNA vaccine prime-IIV3 boost regimen was safe and well tolerated. Significant differences in HAI responses between the DNA vaccine prime and the PBS prime groups were not detected in this study. Conclusion While DNA priming significantly improved the response to a conventional monovalent H5 vaccine in a previous study, it was not effective in adults using seasonal influenza strains, possibly due to pre-existing immunity to the prime, unmatched prime and boost antigens, or the lengthy 36 week boost interval. Careful optimization of the DNA prime-IIV3 boost regimen as related to antigen matching, interval between vaccinations, and pre-existing immune responses to influenza is likely to be needed in further evaluations of this vaccine strategy. In particular, testing this concept in younger age groups with less prior exposure to seasonal influenza strains may be informative. Trial Registration ClinicalTrials.gov NCT01498718 PMID:25950433

  9. Immune response in mice and swine to DNA vaccines derived from the Pasteurella multocida toxin gene

    Technology Transfer Automated Retrieval System (TEKTRAN)

    DNA vaccines were constructed with either a 5’-truncated or full-length, genetically detoxified toxin gene from Pasteurella multocida and two different DNA vaccine vectors, distinguished by the presence or absence of a secretion signal sequence. Optimal PMT-specific antibody responses and spleen cel...

  10. Therapeutic potential of an AcHERV-HPV L1 DNA vaccine.

    PubMed

    Lee, Hee-Jung; Yoon, Jong Kwang; Heo, Yoonki; Cho, Hansam; Cho, Yeondong; Gwon, Yongdae; Kim, Kang Chang; Choi, Jiwon; Lee, Jae Sung; Oh, Yu-Kyoung; Kim, Young Bong

    2015-06-01

    Cervical cancer is strongly associated with chronic human papillomavirus infections, among which HPV16 is the most common. Two commercial HPV vaccines, Gardasil and Cervarix are effective for preventing HPV infection, but cannot be used to treat existing HPV infections. Previously, we developed a human endogenous retrovirus (HERV)-enveloped recombinant baculovirus capable of delivering the L1 genes of HPV types 16, 18, and 58 (AcHERV-HP16/18/58L1, AcHERV-HPV). Intramuscular administration of AcHERVHPV vaccines induced a strong cellular immune response as well as a humoral immune response. In this study, to examine the therapeutic effect of AcHERV-HPV in a mouse model, we established an HPV16 L1 expressing tumor cell line. Compared to Cervarix, immunization with AcHERVHPV greatly enhanced HPV16 L1-specific cytotoxic T lymphocytes (CTL) in C57BL/6 mice. Although vaccination could not remove preexisting tumors, strong CTL activity retarded the growth of inoculated tumor cells. These results indicate that AcHERV-HPV could serve as a potential therapeutic DNA vaccine against concurrent infection with HPV 16, 18, and 58. PMID:26025174

  11. Induction of Broad Cytotoxic T Cells by Protective DNA Vaccination Against Marburg and Ebola

    PubMed Central

    Shedlock, Devon J; Aviles, Jenna; Talbott, Kendra T; Wong, Gary; Wu, Stephan J; Villarreal, Daniel O; Myles, Devin JF; Croyle, Maria A; Yan, Jian; Kobinger, Gary P; Weiner, David B

    2013-01-01

    Marburg and Ebola hemorrhagic fevers have been described as the most virulent viral diseases known to man due to associative lethality rates of up to 90%. Death can occur within days to weeks of exposure and there is currently no licensed vaccine or therapeutic. Recent evidence suggests an important role for antiviral T cells in conferring protection, but little detailed analysis of this response as driven by a protective vaccine has been reported. We developed a synthetic polyvalent-filovirus DNA vaccine against Marburg marburgvirus (MARV), Zaire ebolavirus (ZEBOV), and Sudan ebolavirus (SUDV). Preclinical efficacy studies were performed in guinea pigs and mice using rodent-adapted viruses, whereas murine T-cell responses were extensively analyzed using a novel modified assay described herein. Vaccination was highly potent, elicited robust neutralizing antibodies, and completely protected against MARV and ZEBOV challenge. Comprehensive T-cell analysis revealed cytotoxic T lymphocytes (CTLs) of great magnitude, epitopic breadth, and Th1-type marker expression. This model provides an important preclinical tool for studying protective immune correlates that could be applied to existing platforms. Data herein support further evaluation of this enhanced gene-based approach in nonhuman primate studies for in depth analyses of T-cell epitopes in understanding protective efficacy. PMID:23670573

  12. Evaluation of Different DNA Vaccines against Porcine Reproductive and Respiratory Syndrome (PRRS) in Pigs

    PubMed Central

    Petrini, Stefano; Ramadori, Giorgio; Villa, Riccardo; Borghetti, Paolo; de Angelis, Elena; Cantoni, Anna Maria; Corradi, Attilio; Amici, Augusto; Ferrari, Maura

    2013-01-01

    In veterinary medicine, there have been different experiences with the plasmid DNA vaccination. In this area and with the hypothesis to demonstrate the effectiveness of different plasmids encoding porcine respiratory and reproductive syndrome (PRRS), five DNA vaccines against PRRS were evaluated for their innocuity and efficacy in pigs. Eighteen animals were divided into five groups which were injected with five (A, B, C, D, E) different DNA vaccines. Albeit, none of the proposed vaccines were able to protect the animals against PRRS virus. Only vaccines A and B were able to reduce the clinical signs of the infection. ELISA IgM were detected 30 days after the first vaccination in the pigs injected by Vaccine A or B. ELISA IgG were detected 90 days after the first vaccination in the pigs injected by Vaccine B or C. Neutralizing antibody were detected Post Challenge Days 61 (PCD) in all groups. In the pigs inoculated with Vaccine C, IFN-γ were detected 90 days after first vaccination, and after challenge exposure they increased. In the other groups, the IFN-γ were detected after challenge infection. Pigs injected with each of the vaccines A, B, C, D and E showed a significantly higher level of CD4−CD8+ lymphocytes (p < 0.001) after infection in comparison with their controls. PMID:26344342

  13. Immunogenicity of a novel engineered HIV-1 clade C synthetic consensus-based envelope DNA vaccine.

    PubMed

    Yan, Jian; Corbitt, Natasha; Pankhong, Panyupa; Shin, Thomas; Khan, Amir; Sardesai, Niranjan Y; Weiner, David B

    2011-09-22

    DNA vaccines require significant engineering in order to generate strong CTL responses in both non-human primates and humans. In this study, we designed a clade C env gene (EY3E1-C) to decrease the genetic distances of virus isolates within clade C and focus the induced T cell responses to conserved clade C epitopes. After generating a consensus sequence by analyzing full-length clade C env early transmitter sequences, several modifications were performed to increase the expression of the EY3E1-C, including codon/RNA optimization, addition of Kozak sequence and addition of an IgE leader sequence. We also shortened the V1 and V2 loops to approximate early transmitter isolate sequences and the cytoplasmic tail was truncated to prevent envelope recycling. When studied as a DNA vaccine in Balb/c mice, compared to a primary codon-optimized clade C envelope DNA vaccine (p96ZM651gp140-CD5), this novel construct is up to three times more potent in driving CTL responses. Importantly this construct not only induces stronger cross-reactive cellular responses within clade C, it also induces stronger immune responses against clade B and group M envelope peptide pools than p96ZM651gp140-CD5. Epitope mapping demonstrated that EY3E1-C was able to induce clade C envelope-specific immune responses against 15 peptide pools, clade B envelope-specific immune responses against 19 peptide pools and group M envelope-specific immune responses against 16 peptide pools out of 29, respectively, indicating that a significant increase in the breadth of induced immune responses. The analysis of antibody responses suggested that vaccination of pEY3E1-C could induce a clade C envelope-specific antibody response. The cellular immune responses of pEY3E1-C could be further enhanced when the DNA was delivered by using electroporation (EP). Thus, the synthetic engineered consensus EY3E1-C gene is capable of eliciting stronger and broader CTL responses than primary clade C envelopes. This finding

  14. Protective immune responses to biolistic DNA vaccination of Brugia malayi abundant larval transcript-2.

    PubMed

    Joseph, S K; Sambanthamoorthy, S; Dakshinamoorthy, G; Munirathinam, G; Ramaswamy, K

    2012-10-01

    Biolistic vaccination using gene gun is developed as a safer tool for delivery of DNA vaccines, a technique that combines high vaccine efficiency with lower antigen dosage and lower cost per vaccine dose. In this study, we compared the protective responses in mice after delivering the Brugia malayi abundant larval transcript-2 (BmALT-2) DNA vaccine using the conventional intradermal approach or with the needleless gene gun delivery approach. BmALT-2 is a leading vaccine candidate against B. malayi, a lymphatic filarial parasite of human. After optimizing the DNA dose and gene gun parameters for delivery into mouse skin, groups of mice were biolistically vaccinated with 5 μg of BmALT-2pVAX. Groups of mice vaccinated intradermally with 5 μg or 100 μg of BmALT-2pVAX was used for comparison of vaccine efficacy. Results demonstrated that gene gun vaccination with 5 μg of BmALT-2pVAX conferred significant protection against challenge infection that was comparable to the degree of protection conferred by intradermal vaccination with 100 μg of BmALT-2pVAX. This observation was further supported by an in vitro antibody dependent cellular cytotoxicity (ADCC) assay. Analysis of the immune response showed that the gene gun vaccination predominantly induced an IgG1 antibody response and significantly high Th2 cytokine response (IL-4) from spleen cells compared to intradermal BmALT-2 DNA delivery that induced predominantly an IgG2a and Th1 cytokine response (IFN-γ, IL-12 and TNF-α). These findings show that host protective responses could be achieved with 20 fold decrease in DNA dose using a gene gun and could prove to be an efficient delivery method in BmALT-2 DNA vaccination against lymphatic filariasis. PMID:22885273

  15. Improvement of DNA vaccination by adjuvants and sophisticated delivery devices: vaccine-platforms for the battle against infectious diseases

    PubMed Central

    2015-01-01

    Advantages of DNA vaccination against infectious diseases over more classical immunization methods include the possibilities for rapid manufacture, fast adaptation to newly emerging pathogens and high stability at ambient temperatures. In addition, upon DNA immunization the antigen is produced by the cells of the vaccinated individual, which leads to activation of both cellular and humoral immune responses due to antigen presentation via MHC I and MHC II molecules. However, so far DNA vaccines have shown most efficient immunogenicity mainly in small rodent models, whereas in larger animals including humans there is still the need to improve effectiveness. This is mostly due to inefficient delivery of the DNA plasmid into cells and nuclei. Here, we discuss technologies used to overcome this problem, including physical means such as in vivo electroporation and co-administration of adjuvants. Several of these methods have already entered clinical testing in humans. PMID:25648133

  16. Polymeric penetration enhancers promote humoral immune responses to mucosal vaccines.

    PubMed

    Klein, Katja; Mann, Jamie F S; Rogers, Paul; Shattock, Robin J

    2014-06-10

    Protective mucosal immune responses are thought best induced by trans-mucosal vaccination, providing greater potential to generate potent local immune responses than conventional parenteral vaccination. However, poor trans-mucosal permeability of large macromolecular antigens limits bioavailability to local inductive immune cells. This study explores the utility of polymeric penetration enhancers to promote trans-mucosal bioavailability of insulin, as a biomarker of mucosal absorption, and two vaccine candidates: recombinant HIV-1 envelope glycoprotein (CN54gp140) and tetanus toxoid (TT). Responses to vaccinating antigens were assessed by measurement of serum and the vaginal humoral responses. Polyethyleneimine (PEI), Dimethyl-β-cyclodextrin (DM-β-CD) and Chitosan enhanced the bioavailability of insulin following intranasal (IN), sublingual (SL), intravaginal (I.Vag) and intrarectal (IR) administration. The same penetration enhancers also increased antigen-specific IgG and IgA antibody responses to the model vaccine antigens in serum and vaginal secretions following IN and SL application. Co-delivery of both antigens with PEI or Chitosan showed the highest increase in systemic IgG and IgA responses following IN or SL administration. However the highest IgA titres in vaginal secretions were achieved after IN immunisations with PEI and Chitosan. None of the penetration enhancers were able to increase antibody responses to gp140 after I.Vag immunisations, while in contrast PEI and Chitosan were able to induce TT-specific systemic IgG levels following I.Vag administration. In summary, we present supporting data that suggest appropriate co-formulation of vaccine antigens with excipients known to influence mucosal barrier functions can increase the bioavailability of mucosally applied antigens promoting the induction of mucosal and systemic antibody responses. PMID:24657807

  17. Secure splenic delivery of plasmid DNA and its application to DNA vaccine.

    PubMed

    Kurosaki, Tomoaki; Kodama, Yukinobu; Muro, Takahiro; Higuchi, Norihide; Nakamura, Tadahiro; Kitahara, Takashi; Miyakoda, Mana; Yui, Katsuyuki; Sasaki, Hitoshi

    2013-01-01

    In this experiment, we developed a novel safe and effective gene delivery vector coated with γ-polyglutamic acid (γ-PGA-coated complexes). The γ-PGA-coated complex was composed of chiseled spherical nano-particles with anionic charges. The plasmid DNA/polyethyleneimine complex (non-coated complex) showed high transgene efficiency in the spleen and lung after intravenous administration in mice, with high liver toxicity and lethality. On the other hand, γ-PGA-coated complex selectively showed high transgene efficiency in the spleen without such toxicity. Furthermore, the γ-PGA-coated complex highly accumulated and showed high gene expression in the marginal zone of the spleen. Those results strongly indicated that γ-PGA-coated complex was suitable as a DNA vaccine vector. We therefore applied γ-PGA-coated complex to melanoma DNA vaccine, pUb-M. The γ-PGA-coated complex containing pUb-M significantly inhibited the growth and metastasis of a melanoma cell line, B16-F10 cells. In conclusion, we developed a splenic gene vector, γ-PGA-coated complex, as a novel technology for clinical vaccination. PMID:24189423

  18. Clearance of persistent HPV infection and cervical lesion by therapeutic DNA vaccine in CIN3 patients

    PubMed Central

    Kim, Tae Jin; Jin, Hyun-Tak; Hur, Soo-Young; Yang, Hyun Gul; Seo, Yong Bok; Hong, Sung Ran; Lee, Chang-Woo; Kim, Suhyeon; Woo, Jung-Won; Park, Ki Seok; Hwang, Youn-Young; Park, Jaehan; Lee, In-Ho; Lim, Kyung-Taek; Lee, Ki-Heon; Jeong, Mi Seon; Surh, Charles D.; Suh, You Suk; Park, Jong Sup; Sung, Young Chul

    2014-01-01

    Here, we demonstrate that electroporation-enhanced immunization with a rationally designed HPV DNA vaccine (GX-188E), preferentially targeting HPV antigens to dendritic cells, elicits a significant E6/E7-specific IFN-γ-producing T-cell response in all nine cervical intraepithelial neoplasia 3 (CIN3) patients. Importantly, eight out of nine patients exhibit an enhanced polyfunctional HPV-specific CD8 T-cell response as shown by an increase in cytolytic activity, proliferative capacity and secretion of effector molecules. Notably, seven out of nine patients display complete regression of their lesions and viral clearance within 36 weeks of follow up. GX-188E administration does not elicit serious vaccine-associated adverse events at all administered doses. These findings indicate that the magnitude of systemic polyfunctional CD8 T-cell response is the main contributing factor for histological, cytological and virological responses, providing valuable insights into the design of therapeutic vaccines for effectively treating persistent infections and cancers in humans. PMID:25354725

  19. Clearance of persistent HPV infection and cervical lesion by therapeutic DNA vaccine in CIN3 patients.

    PubMed

    Kim, Tae Jin; Jin, Hyun-Tak; Hur, Soo-Young; Yang, Hyun Gul; Seo, Yong Bok; Hong, Sung Ran; Lee, Chang-Woo; Kim, Suhyeon; Woo, Jung-Won; Park, Ki Seok; Hwang, Youn-Young; Park, Jaehan; Lee, In-Ho; Lim, Kyung-Taek; Lee, Ki-Heon; Jeong, Mi Seon; Surh, Charles D; Suh, You Suk; Park, Jong Sup; Sung, Young Chul

    2014-01-01

    Here, we demonstrate that electroporation-enhanced immunization with a rationally designed HPV DNA vaccine (GX-188E), preferentially targeting HPV antigens to dendritic cells, elicits a significant E6/E7-specific IFN-γ-producing T-cell response in all nine cervical intraepithelial neoplasia 3 (CIN3) patients. Importantly, eight out of nine patients exhibit an enhanced polyfunctional HPV-specific CD8 T-cell response as shown by an increase in cytolytic activity, proliferative capacity and secretion of effector molecules. Notably, seven out of nine patients display complete regression of their lesions and viral clearance within 36 weeks of follow up. GX-188E administration does not elicit serious vaccine-associated adverse events at all administered doses. These findings indicate that the magnitude of systemic polyfunctional CD8 T-cell response is the main contributing factor for histological, cytological and virological responses, providing valuable insights into the design of therapeutic vaccines for effectively treating persistent infections and cancers in humans. PMID:25354725

  20. GRA7 provides protective immunity in cocktail DNA vaccines against Toxoplasma gondii.

    PubMed

    Jongert, E; de Craeye, S; Dewit, J; Huygen, K

    2007-09-01

    In a previous study, single-gene vaccination with GRA1, GRA7 or ROP2 was shown to elicit partial protection against Toxoplasma gondii. In this study, the contribution of each antigen in the evoked humoral and cellular immune responses was evaluated after vaccination with plasmid mixtures containing GRA1, GRA7 and ROP2. Cocktail DNA vaccinated mice developed high antibody titers against the antigens from two-gene DNA vaccine cocktails, but lower titres when immunized with the three-gene cocktail. High numbers of IFN-gamma secreting splenocytes were generated predominantly against GRA7. Brain cyst burden was reduced by 81% in mice vaccinated with the three-gene mixture and they were completely protected against acute toxoplasmosis. Similar high levels of brain cyst reductions were obtained after vaccination with cocktails composed of GRA1 and GRA7 (89% reduction), or GRA7 and ROP2 (79% reduction), but not with the cocktail composed of GRA1 and ROP2. In low dose single-gene vaccinations, IFN-gamma and strong protection could only be elicited by GRA7. Hence, the presence of GRA7 in the DNA vaccine formulation was important for optimal protection and this was correlated with GRA7-specific IFN-gamma production. We propose GRA7 as a main component in cocktail DNA vaccines for vaccination against T. gondii. PMID:17727568

  1. Induction of Neutralization Antibodies in Mice by Dengue-2 Envelope DNA Vaccines

    PubMed Central

    PÉREZ-VÉLEZ, MARIEL E.; GARCÍA-NIEVES, TERESITA; COLÓN-SÁNCHEZ, CANDIMAR; MARTÍNEZ, IDALÍ

    2010-01-01

    Background Dengue (DEN) viruses have become a public health problem that affects approximately 100 million people worldwide each year. Prevention measures rely on vector control programs, which are inefficient. Therefore, a vaccine is urgently needed. Methods The main goal of our laboratory is to develop an efficient tetravalent DEN DNA vaccine. In this study, we constructed four DEN-2 DNA vaccines expressing prM/env genes, using the homologous leader sequence (VecD2, VRD2E) or the tissue plasminogen activator (tPA) secretory signal (VecD2tpa, VRD2tpa). In vitro expression was tested by transient transfections and Western blot. The immunogenicity and protective efficacy of the vaccine candidates was evaluated in BALB/c mice, using intramuscular (IM) and intradermal (ID) vaccination routes. Results Envelope (E) protein expression was detected in transfected COS-7 or 293T cells. We found statistical differences in the antibody responses induced by these vaccine candidates. In addition, the strongest antibody responses and protection were observed when the vaccines were delivered intramuscularly. Moreover, the tPA leader sequence did not significantly improve the vaccine immunogenicity since VecD2 and VecD2tpa induced similar antibody responses. Conclusions We demonstrated that most of our DNA vaccine candidates could induce antibody responses and partial protection against DEN-2 virus in mice. These results provide valuable information for the design and construction of a tetravalent DEN DNA vaccine. PMID:19715116

  2. A combined DNA vaccine provides protective immunity against Mycobacterium bovis and Brucella abortus in cattle.

    PubMed

    Hu, Xi-Dan; Yu, Da-Hai; Chen, Su-Ting; Li, Shu-Xia; Cai, Hong

    2009-04-01

    We evaluated the immunogenicity and protective efficacy of a combined DNA vaccine containing six genes encoding immunodominant antigens from Mycobacterium bovis and Brucella abortus. The number of lymph node and spleen cultures positive for M. bovis and B. abortus from calves immunized with the combined DNA vaccine was significantly reduced (p < 0.01) compared with unvaccinated calves after challenge with virulent M. bovis and B. abortus 544. The combined DNA vaccine group displayed stronger antigen-specific interferon-gamma (IFN-gamma) responses and antigen-specific IFN-gamma ELISPOT activities 2 months after final immunization and after challenge. Antigen-specific CD4(+) and CD8(+) T cell responses in the combined DNA vaccine group were higher than either the Bacillus Calmette-Guerin (BCG)-positive or S19-positive control group. Likewise, more calves in the DNA vaccine group exhibited antigen-specific IgG titers and had higher IgG titers than those in the BCG- or S19-immunized groups 2 months after the final immunization. Moreover, two antigens in the combined DNA vaccine induced significant antigen-specific IFN-gamma responses 6 months after challenge (p < 0.05). Bacterial counts and pathological analyses of the challenged animals indicated that the combined DNA vaccine provided significantly better protection than the BCG vaccine against M. bovis, and the protection level induced by the combined DNA vaccine was comparable to S19 against B. abortus. This is the first report to demonstrate that a single combined DNA vaccine protects cattle against two infectious diseases. PMID:19364278

  3. Immunogenicity of Virus Like Particle Forming Baculoviral DNA Vaccine against Pandemic Influenza H1N1

    PubMed Central

    Gwon, Yong-Dae; Kim, Sehyun; Cho, Yeondong; Heo, Yoonki; Cho, Hansam; Park, Kihoon; Lee, Hee-Jung; Choi, Jiwon; Poo, Haryoung; Kim, Young Bong

    2016-01-01

    An outbreak of influenza H1N1 in 2009, representing the first influenza pandemic of the 21st century, was transmitted to over a million individuals and claimed 18,449 lives. The current status in many countries is to prepare influenza vaccine using cell-based or egg-based killed vaccine. However, traditional influenza vaccine platforms have several limitations. To overcome these limitations, many researchers have tried various approaches to develop alternative production platforms. One of the alternative approach, we reported the efficacy of influenza HA vaccination using a baculoviral DNA vaccine (AcHERV-HA). However, the immune response elicited by the AcHERV-HA vaccine, which only targets the HA antigen, was lower than that of the commercial killed vaccine. To overcome the limitations of this previous vaccine, we constructed a human endogenous retrovirus (HERV) envelope-coated, baculovirus-based, virus-like-particle (VLP)–forming DNA vaccine (termed AcHERV-VLP) against pandemic influenza A/California/04/2009 (pH1N1). BALB/c mice immunized with AcHERV-VLP (1×107 FFU AcHERV-VLP, i.m.) and compared with mice immunized with the killed vaccine or mice immunized with AcHERV-HA. As a result, AcHERV-VLP immunization produced a greater humoral immune response and exhibited neutralizing activity with an intrasubgroup H1 strain (PR8), elicited neutralizing antibody production, a high level of interferon-γ secretion in splenocytes, and diminished virus shedding in the lung after challenge with a lethal dose of influenza virus. In conclusion, VLP-forming baculovirus DNA vaccine could be a potential vaccine candidate capable of efficiently delivering DNA to the vaccinee and VLP forming DNA eliciting stronger immunogenicity than egg-based killed vaccines. PMID:27149064

  4. Immunogenicity of Virus Like Particle Forming Baculoviral DNA Vaccine against Pandemic Influenza H1N1.

    PubMed

    Gwon, Yong-Dae; Kim, Sehyun; Cho, Yeondong; Heo, Yoonki; Cho, Hansam; Park, Kihoon; Lee, Hee-Jung; Choi, Jiwon; Poo, Haryoung; Kim, Young Bong

    2016-01-01

    An outbreak of influenza H1N1 in 2009, representing the first influenza pandemic of the 21st century, was transmitted to over a million individuals and claimed 18,449 lives. The current status in many countries is to prepare influenza vaccine using cell-based or egg-based killed vaccine. However, traditional influenza vaccine platforms have several limitations. To overcome these limitations, many researchers have tried various approaches to develop alternative production platforms. One of the alternative approach, we reported the efficacy of influenza HA vaccination using a baculoviral DNA vaccine (AcHERV-HA). However, the immune response elicited by the AcHERV-HA vaccine, which only targets the HA antigen, was lower than that of the commercial killed vaccine. To overcome the limitations of this previous vaccine, we constructed a human endogenous retrovirus (HERV) envelope-coated, baculovirus-based, virus-like-particle (VLP)-forming DNA vaccine (termed AcHERV-VLP) against pandemic influenza A/California/04/2009 (pH1N1). BALB/c mice immunized with AcHERV-VLP (1×107 FFU AcHERV-VLP, i.m.) and compared with mice immunized with the killed vaccine or mice immunized with AcHERV-HA. As a result, AcHERV-VLP immunization produced a greater humoral immune response and exhibited neutralizing activity with an intrasubgroup H1 strain (PR8), elicited neutralizing antibody production, a high level of interferon-γ secretion in splenocytes, and diminished virus shedding in the lung after challenge with a lethal dose of influenza virus. In conclusion, VLP-forming baculovirus DNA vaccine could be a potential vaccine candidate capable of efficiently delivering DNA to the vaccinee and VLP forming DNA eliciting stronger immunogenicity than egg-based killed vaccines. PMID:27149064

  5. Evaluation of DNA encoding acidic ribosomal protein P2 of Cryptosporidium parvum as a potential vaccine candidate for cryptosporidiosis

    PubMed Central

    Benitez, Alvaro; Priest, Jeffrey W.; Ehigiator, Humphrey N.; McNair, Nina; Mead, Jan R.

    2011-01-01

    The Cryptosporidium parvum acidic ribosomal protein P2 (CpP2) is an important immunodominant marker in C. parvum infection. In this study, the CpP2 antigen was evaluated as a vaccine candidate using a DNA vaccine model in adult C57BL/6 IL-12 knockout (KO) mice, which are susceptible to C. parvum infection. Our data show that subcutaneous immunization in the ear with DNA encoding CpP2 (CpP2-DNA) cloned into the pUMVC4b vector induced a significant anti-CpP2 IgG antibody response that was predominantly of the IgG1 isotype. Compared to control KO mice immunized with plasmid alone, CpP2-immunized mice demonstrated specific in vitro spleen cell proliferation as well as enhanced IFN-γ production to recombinant CpP2. Further, parasite loads in CpP2 DNA-immunized mice were compared to control mice challenged with C. parvum oocysts. Although a trend in reduction of infection was observed in the CpP2 DNA-immunized mice, differences between groups were not statistically significant. These results suggest that a DNA vaccine encoding the C. parvum P2 antigen is able to provide an effective means of eliciting humoral and cellular responses and has the potential to generate protective immunity against C. parvum infection but may require using alternative vectors or adjuvant to generate a more potent and balanced response. PMID:21968447

  6. Immune response to dna vaccine expressing transferrin binding protein a gene of Pasteurella multocida.

    PubMed

    Singh, Satparkash; Singh, Vijendra Pal; Cheema, Pawanjit Singh; Sandey, Maninder; Ranjan, Rajeev; Gupta, Santosh Kumar; Sharma, Bhaskar

    2011-04-01

    Haemorrhagic Septicaemia (HS), an acute and fatal disease of cattle and buffalo is primarily caused by serotype B:2 or E:2 of Pasteurella multocida. The transferrin binding protein A (TbpA) has been found to act as immunogen and potent vaccine candidate in various Gram negative bacteria including P. multocida. The present study was carried out to evaluate the potential of this antigen as a DNA vaccine against HS in mice model. The tbpA gene of P. multocida serotype B:2 was cloned in a mammalian expression vector alone and along with murine IL2 gene as immunological adjuvant to produce monocistronic and bicistronic DNA vaccine constructs, respectively. The immune response to DNA vaccines was evaluated based on serum antibody titres and lymphocyte proliferation assay. A significant increase in humoral and cell mediated immune responses was observed in mice vaccinated with DNA vaccines as compared to non immunized group. Additionally, the bicistronic DNA vaccine provided superior immune response and protection level following challenge as compared to monocistronic construct. The study revealed that DNA vaccine presents a promising approach for the prevention of HS. PMID:24031690

  7. What you always needed to know about electroporation based DNA vaccines

    PubMed Central

    Gothelf, Anita; Gehl, Julie

    2012-01-01

    Vaccinations are increasingly used to fight infectious disease, and DNA vaccines offer considerable advantages, including broader possibilities for vaccination and lack of need for cold storage. It has been amply demonstrated, that electroporation augments uptake of DNA in both skin and muscle, and it is foreseen that future DNA vaccination may to a large extent be coupled with and dependent upon electroporation based delivery. Understanding the basic science of electroporation and exploiting knowledge obtained on optimization of DNA electrotransfer to muscle and skin, may greatly augment efforts on vaccine development. The purpose of this review is to give a succinct but comprehensive overview of electroporation as a delivery modality including electrotransfer to skin and muscle. As well, this review will speculate and discuss future uses for this powerful electrotransfer technology. PMID:23111168

  8. Subtype C gp140 Vaccine Boosts Immune Responses Primed by the South African AIDS Vaccine Initiative DNA-C2 and MVA-C HIV Vaccines after More than a 2-Year Gap

    PubMed Central

    Mayer, Kenneth H.; Elizaga, Marnie L.; Bekker, Linda-Gail; Allen, Mary; Morris, Lynn; Montefiori, David; De Rosa, Stephen C.; Sato, Alicia; Gu, Niya; Tomaras, Georgia D.; Tucker, Timothy; Barnett, Susan W.; Mkhize, Nonhlanhla N.; Shen, Xiaoying; Downing, Katrina; Williamson, Carolyn; Pensiero, Michael; Corey, Lawrence; Williamson, Anna-Lise

    2016-01-01

    A phase I safety and immunogenicity study investigated South African AIDS Vaccine Initiative (SAAVI) HIV-1 subtype C (HIV-1C) DNA vaccine encoding Gag-RT-Tat-Nef and gp150, boosted with modified vaccinia Ankara (MVA) expressing matched antigens. Following the finding of partial protective efficacy in the RV144 HIV vaccine efficacy trial, a protein boost with HIV-1 subtype C V2-deleted gp140 with MF59 was added to the regimen. A total of 48 participants (12 U.S. participants and 36 Republic of South Africa [RSA] participants) were randomized to receive 3 intramuscular (i.m.) doses of SAAVI DNA-C2 of 4 mg (months 0, 1, and 2) and 2 i.m. doses of SAAVI MVA-C of 1.45 × 109 PFU (months 4 and 5) (n = 40) or of a placebo (n = 8). Approximately 2 years after vaccination, 27 participants were rerandomized to receive gp140/MF59 at 100 μg or placebo, as 2 i.m. injections, 3 months apart. The vaccine regimen was safe and well tolerated. After the DNA-MVA regimen, CD4+ T-cell and CD8+ T-cell responses occurred in 74% and 32% of the participants, respectively. The protein boost increased CD4+ T-cell responses to 87% of the subjects. All participants developed tier 1 HIV-1C neutralizing antibody responses as well as durable Env binding antibodies that recognized linear V3 and C5 peptides. The HIV-1 subtype C DNA-MVA vaccine regimen showed promising cellular immunogenicity. Boosting with gp140/MF59 enhanced levels of binding and neutralizing antibodies as well as CD4+ T-cell responses to HIV-1 envelope. (This study has been registered at ClinicalTrials.gov under registration no. NCT00574600 and NCT01423825.) PMID:27098021

  9. Subtype C gp140 Vaccine Boosts Immune Responses Primed by the South African AIDS Vaccine Initiative DNA-C2 and MVA-C HIV Vaccines after More than a 2-Year Gap.

    PubMed

    Gray, Glenda E; Mayer, Kenneth H; Elizaga, Marnie L; Bekker, Linda-Gail; Allen, Mary; Morris, Lynn; Montefiori, David; De Rosa, Stephen C; Sato, Alicia; Gu, Niya; Tomaras, Georgia D; Tucker, Timothy; Barnett, Susan W; Mkhize, Nonhlanhla N; Shen, Xiaoying; Downing, Katrina; Williamson, Carolyn; Pensiero, Michael; Corey, Lawrence; Williamson, Anna-Lise

    2016-06-01

    A phase I safety and immunogenicity study investigated South African AIDS Vaccine Initiative (SAAVI) HIV-1 subtype C (HIV-1C) DNA vaccine encoding Gag-RT-Tat-Nef and gp150, boosted with modified vaccinia Ankara (MVA) expressing matched antigens. Following the finding of partial protective efficacy in the RV144 HIV vaccine efficacy trial, a protein boost with HIV-1 subtype C V2-deleted gp140 with MF59 was added to the regimen. A total of 48 participants (12 U.S. participants and 36 Republic of South Africa [RSA] participants) were randomized to receive 3 intramuscular (i.m.) doses of SAAVI DNA-C2 of 4 mg (months 0, 1, and 2) and 2 i.m. doses of SAAVI MVA-C of 1.45 × 10(9) PFU (months 4 and 5) (n = 40) or of a placebo (n = 8). Approximately 2 years after vaccination, 27 participants were rerandomized to receive gp140/MF59 at 100 μg or placebo, as 2 i.m. injections, 3 months apart. The vaccine regimen was safe and well tolerated. After the DNA-MVA regimen, CD4(+) T-cell and CD8(+) T-cell responses occurred in 74% and 32% of the participants, respectively. The protein boost increased CD4(+) T-cell responses to 87% of the subjects. All participants developed tier 1 HIV-1C neutralizing antibody responses as well as durable Env binding antibodies that recognized linear V3 and C5 peptides. The HIV-1 subtype C DNA-MVA vaccine regimen showed promising cellular immunogenicity. Boosting with gp140/MF59 enhanced levels of binding and neutralizing antibodies as well as CD4(+) T-cell responses to HIV-1 envelope. (This study has been registered at ClinicalTrials.gov under registration no. NCT00574600 and NCT01423825.). PMID:27098021

  10. Immunogenicity of varicella zoster virus glycoprotein E DNA vaccine

    PubMed Central

    BAO, LIDAO; WEI, GUOMIN; GAN, HONGMEI; REN, XIANHUA; MA, RUILIAN; WANG, YI; LV, HAIJUN

    2016-01-01

    In the present study a eukaryotic expression vector of varicella zoster virus (VZV) glycoprotein E (gE) was constructed and enabled to express in COS7 cells. Furthermore, a specific immune response against the VZV gE eukaryotic expression plasmid was induced in BALB/c mice. The VZV gE gene was amplified using polymerase chain reaction (PCR) and cloned into a eukaryotic expression vector, pcDNA3.1. The recombinant vector was subsequently transfected into COS7 cells using a liposome transfection reagent. The recombinant protein was instantaneously expressed by the transfected cells, as detected by immunohistochemistry, and the recombinant pcDNA-VZV gE plasmid was subsequently used to immunize mice. Tissue expression levels were analyzed by reverse transcription-PCR. In addition, the levels of serum antibodies and spleen lymphocyte proliferation activity were investigated. The amplified target gene included the full-length gE gene (~2.7 kb), and the recombinant expression vector induced gE expression in COS7 cells. In addition, the expression plasmid induced sustained expression in vivo following immunization of mice. Furthermore, the plasmid was capable of inducing specific antibody production and effectively stimulating T cell proliferation. Effective humoral and cellular immunity was triggered in the mice immunized with the VZV gE eukaryotic expression vector. The results of the present study laid the foundation for future research into a VZV DNA vaccine. PMID:27168804

  11. Comprehensive gene expression profiling following DNA vaccination of rainbow trout against infectious hematopoietic necrosis virus

    USGS Publications Warehouse

    Purcell, Maureen K.; Nichols, Krista M.; Winton, James R.; Kurath, Gael; Thorgaard, Gary H.; Wheeler, Paul; Hansen, John D.; Herwig, Russell P.; Park, Linda K.

    2006-01-01

    The DNA vaccine based on the glycoprotein gene of Infectious hematopoietic necrosis virus induces a non-specific anti-viral immune response and long-term specific immunity against IHNV. This study characterized gene expression responses associated with the early anti-viral response. Homozygous rainbow trout were injected intra-muscularly (I.M.) with vector DNA or the IHNV DNA vaccine. Gene expression in muscle tissue (I.M. site) was evaluated using a 16,008 feature salmon cDNA microarray. Eighty different genes were significantly modulated in the vector DNA group while 910 genes were modulated in the IHNV DNA vaccinate group relative to control group. Quantitative reverse-transcriptase PCR was used to examine expression of selected immune genes at the I.M. site and in other secondary tissues. In the localized response (I.M. site), the magnitudes of gene expression changes were much greater in the vaccinate group relative to the vector DNA group for the majority of genes analyzed. At secondary systemic sites (e.g. gill, kidney and spleen), type I IFN-related genes were up-regulated in only the IHNV DNA vaccinated group. The results presented here suggest that the IHNV DNA vaccine induces up-regulation of the type I IFN system across multiple tissues, which is the functional basis of early anti-viral immunity.

  12. Protection against H1N1 influenza challenge by a DNA vaccine expressing H3/H1 subtype hemagglutinin combined with MHC class II-restricted epitopes

    PubMed Central

    2010-01-01

    Background Multiple subtypes of avian influenza viruses have crossed the species barrier to infect humans and have the potential to cause a pandemic. Therefore, new influenza vaccines to prevent the co-existence of multiple subtypes within a host and cross-species transmission of influenza are urgently needed. Methods Here we report a multi-epitope DNA vaccine targeted towards multiple subtypes of the influenza virus. The protective hemagglutinin (HA) antigens from H5/H7/H9 subtypes were screened for MHC II class-restricted epitopes overlapping with predicted B cell epitopes. We then constructed a DNA plasmid vaccine, pV-H3-EHA-H1, based on HA antigens from human influenza H3/H1 subtypes combined with the H5/H7/H9 subtype Th/B epitope box. Results Epitope-specific IFN-γ ELISpot responses were significantly higher in the multi-epitope DNA group than in other vaccine and control groups (P < 0.05). The multi-epitope group significantly enhanced Th2 cell responses as determined by cytokine assays. The survival rate of mice given the multi-epitope vaccine was the highest among the vaccine groups, but it was not significantly different compared to those given single antigen expressing pV-H1HA1 vaccine and dual antigen expressing pV-H3-H1 vaccine (P > 0.05). No measurable virus titers were detected in the lungs of the multi-epitope immunized group. The unique multi-epitope DNA vaccine enhanced virus-specific antibody and cellular immunity as well as conferred complete protection against lethal challenge with A/New Caledonia/20/99 (H1N1) influenza strain in mice. Conclusions This approach may be a promising strategy for developing a universal influenza vaccine to prevent multiple subtypes of influenza virus and to induce long-term protective immune against cross-species transmission. PMID:21134292

  13. Modulatory effect of CpG oligodeoxynucleotide on a DNA vaccine against nervous necrosis virus in orange-spotted grouper (Epinephelus coioides).

    PubMed

    Chen, Shiang-Peng; Peng, Ran-Hong; Chiou, Pinwen P

    2015-08-01

    We report the development of a DNA vaccine pcMGNNV2 against nervous necrosis virus (NNV), a leading cause of mass mortality in grouper larvae. In addition, the modulatory effect of CpG oligodeoxynucleotide (ODN), a Toll-like receptor 9 agonist, on the DNA vaccine was evaluated. The DNA vaccine alone elicited the production of NNV-specific antibodies, indicating that the vaccine was capable of triggering adaptive humoral response. Furthermore, significant induction of TLR9, Mx and IL-1β was observed in the spleen on day 7 post-vaccination, supporting that the vaccine could trigger TLR9 signaling. The incorporation of CpG ODN at high dose did not significantly affect the level of NNV-specific antibodies, but was able to moderately enhance the expression of Mx and IL-1β on day 7, indicating its ability in modulating innate response. After challenge with NNV, the vaccine alone enhanced the survival rate in infected larvae at both 1 and 2 weeks post-vaccination. The combination of CpG ODN further increased the survival rate at week 1 but not week 2. Interestingly, at week 2 the ODN appeared to induce a Th1-like response, as indicated by upregulation of T-bet (a Th1 marker) and downregulation of GATA-3 (a Th2 marker). Thus, the results suggest that the boosted Th1 response by CpG ODN does not augment the protection efficacy of pcMGNNV2 vaccine. To our best knowledge, this is the first report of a successful DNA vaccine against NNV in grouper. PMID:26093207

  14. Construction, purification, and evaluation of multivalent DNA vaccine against Schistosoma japonicum.

    PubMed

    Zhu, Lu; Liu, Hai-Feng; Lu, Ming-Bo; Long, Quan-Ke; Shi, You-En; Yu, Long-Jiang

    2011-01-01

    DNA vaccine encoding a multivalent antigen is a novel approach of protective immunization. Four Schistosoma japonicum candidate antigen genes, glyceraldehyde-3-phosphate dehydrogenase (SjGAPDH), 23 kDa transmembrane protein (Sj23), 14 kDa fatty-acid binding protein (SjFABP) and 26 kDa glutathione-S-transferase (Sj26), are recombined into two pieces of fusion genes SjFABP.Sj23 and Sj26.SjGAPDH, respectively. Tetravalent DNA vaccine pVIVO2-SjFABP.Sj23/Sj26.SjGAPDH is constructed by co-expressing these two fusion genes. The super-coiled DNA vaccines for large-scale clinic application were purified by sequential chromatographies including group separation chromatography and affinitive chromatographies. The purified DNA vaccines were evaluated for in vivo and in vitro transfection assay. The immunoprotective properties of the different kinds of constructed DNA vaccines were appraised by pharmacological trials. The pharmacological trials results showed that tetravalent DNA vaccine has higher protective efficiency than other tested DNA vaccines. PMID:20852891

  15. Towards a metalloprotease-DNA vaccine against piscine cryptobiosis caused by Cryptobia salmositica.

    PubMed

    Tan, Chung-Wei; Jesudhasan, Palmy; Woo, Patrick T K

    2008-01-01

    Cysteine protease is a metabolic enzyme, whereas metalloprotease is the virulent factor in cryptobiosis caused by Cryptobia salmositica. Recombinant DNA vaccines were produced with the insertion of either the metalloprotease or cysteine protease gene of C. salmositica into plasmid vectors (pEGFP-N). As expected, fishes (Oncorhynchus mykiss and Salmo salar) injected intramuscularly with the metalloprotease-DNA (MP-DNA) vaccine (50 microg/fish) were consistently more anemic (lower packed cell volume, PCV) than controls (injected only with the plasmid) at 3-5 weeks post-inoculation. Also, there were no difference in PCV between fish injected with the cysteine-DNA plasmids and the controls. In addition, agglutinating antibodies against Cryptobia were detected only in the blood of MP-DNA-vaccinated fish at 5-7 weeks post-vaccination and not in cysteine-DNA plasmids and the control groups. MP-DNA-vaccinated fish when challenged with the pathogen had consistently lower parasitemia, delayed peak parasitemia, and faster recovery compared with the controls. All fish vaccinated with attenuated strain were protected when challenged with the pathogen; this positive control group confirmed that the two vaccines operate through different mechanisms. PMID:17932691

  16. Vaccinations in disease models with antibody-dependent enhancement.

    PubMed

    Billings, Lora; Fiorillo, Amy; Schwartz, Ira B

    2008-02-01

    This paper examines the effects of single-strain vaccine campaigns on the dynamics of an epidemic multistrain model with antibody-dependent enhancement (ADE). ADE is a disease spreading process causing individuals with their secondary infection to be more infectious than during their first infection by a different strain. We follow the two-strain ADE model described in Cummings et al. [D.A.T. Cummings, Doctoral Thesis, Johns Hopkins University, 2004] and Schwartz et al. [I.B. Schwartz, L.B. Shaw, D.A.T. Cummings, L. Billings, M. McCrary, D. Burke, Chaotic desynchronization of multi-strain diseases, Phys. Rev. E, 72:art. no. 066201, 2005]. After describing the model and its steady state solutions, we modify it to include vaccine campaigns and explore if there exists vaccination rates that can eradicate one or more strains of a virus with ADE. PMID:17923138

  17. Immunogenicity in mice and rabbits of DNA vaccines expressing woodchuck hepatitis virus antigens.

    PubMed

    Luxembourg, Alain; Hannaman, Drew; Wills, Ken; Bernard, Robert; Tennant, Bud C; Menne, Stephan; Cote, Paul J

    2008-07-29

    The licensed vaccine against hepatitis B virus (HBV) is an effective means to prevent infection, but is not an effective therapeutic strategy to treat established chronic infections when used alone. In an animal model of chronic HBV infection (the woodchuck experimentally infected with woodchuck hepatitis virus (WHV)), the combination of conventional vaccine and potent antiviral drugs has shown promise as a potential therapeutic intervention. This approach might be improved further through the application of newer vaccine technologies. In the present study, we evaluated electroporation (EP)-based intramuscular (i.m.) delivery of a codon-optimized DNA vaccine for the WHV surface antigen (WHsAg) in mice and rabbits. In mice, this immunization procedure compared favorably to vaccination by i.m. injection of the DNA vaccine or i.m. administration of a recombinant WHsAg-alum vaccine, exhibiting characteristics expected to be beneficial for a therapeutic vaccine strategy. These included dose efficiency, consistency, vigorous induction of antibody responses to WHsAg, as well as a Th1 bias. Following scale-up to rabbits, a species that approximates the size of the woodchuck, the EP dosing regimen was markedly more effective than conventional i.m. injection of the DNA vaccine. Taken together, these results provide the foundation for studies of EP-based DNA immunization in the woodchuck in order to further assess its potential as an immunotherapeutic approach for treatment of chronic HBV infection in humans. PMID:18556096

  18. Can VHS Virus Bypass the Protective Immunity Induced by DNA Vaccination in Rainbow Trout?

    PubMed Central

    Sepúlveda, Dagoberto; Lorenzen, Niels

    2016-01-01

    DNA vaccines encoding viral glycoproteins have been very successful for induction of protective immunity against diseases caused by rhabdoviruses in cultured fish species. However, the vaccine concept is based on a single viral gene and since RNA viruses are known to possess high variability and adaptation capacity, this work aimed at evaluating whether viral haemorrhagic septicaemia virus (VHSV), an RNA virus and member of Rhabdoviridae family, was able to evade the protective immune response induced by the DNA vaccination of rainbow trout. The experiments comprised repeated passages of a highly pathogenic VHSV isolate in a fish cell line in the presence of neutralizing fish serum (in vitro approach), and in rainbow trout immunized with the VHS DNA vaccine (in vivo approach). For the in vitro approach, the virus collected from the last passage (passaged virus) was as sensitive as the parental virus to serum neutralization, suggesting that the passaging did not promote the selection of virus populations able to bypass the neutralization by serum antibodies. Also, in the in vivo approach, where virus was passaged several times in vaccinated fish, no increased virulence nor increased persistence in vaccinated fish was observed in comparison with the parental virus. However, some of the vaccinated fish did get infected and could transmit the infection to naïve cohabitant fish. The results demonstrated that the DNA vaccine induced a robust protection, but also that the immunity was non-sterile. It is consequently important not to consider vaccinated fish as virus free in veterinary terms. PMID:27054895

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

    PubMed Central

    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. PMID:26091084

  20. An Epitope-Substituted DNA Vaccine Improves Safety and Immunogenicity against Dengue Virus Type 2

    PubMed Central

    Tang, Chung-Tao; Li, Pi-Chun; Liu, I-Ju; Liao, Mei-Ying; Chiu, Chiung-Yi; Chao, Day-Yu; Wu, Han-Chung

    2015-01-01

    Dengue virus (DENV), a global disease, is divided into four serotypes (DENV1-4). Cross-reactive and non-neutralizing antibodies against envelope (E) protein of DENV bind to the Fcγ receptors (FcγR) of cells, and thereby exacerbate viral infection by heterologous serotypes via antibody-dependent enhancement (ADE). Identification and modification of enhancing epitopes may mitigate enhancement of DENV infection. In this study, we characterized the cross-reactive DB21-6 and DB39-2 monoclonal antibodies (mAbs) against domain I-II of DENV; these antibodies poorly neutralized and potently enhanced DENV infection both in vitro and in vivo. In addition, two enhancing mAbs, DB21-6 and DB39-2, were observed to compete with sera antibodies from patients infected with dengue. The epitopes of these enhancing mAbs were identified using phage display, structural prediction, and mapping of virus-like particle (VLP) mutants. N8, R9, V12, and E13 are the reactive residues of DB21-6, while N8, R9, and E13 are the reactive residues of DB39-2. N8 substitution tends to maintain VLP secretion, and decreases the binding activity of DB21-6 and DB39-2. The immunized sera from N8 substitution (N8R) DNA vaccine exerted greater neutralizing and protective activity than wild-type (WT)-immunized sera, both in vitro and in vivo. Furthermore, treatment with N8R-immunized sera reduced the enhancement of mortality in AG129 mice. These results support identification and substitution of enhancing epitope as a novel strategy for developing safe dengue vaccines. PMID:26135599

  1. Administration of HPV DNA vaccine via electroporation elicits the strongest CD8+ T cell immune responses compared to intramuscular injection and intradermal gene gun delivery.

    PubMed

    Best, Simon R; Peng, Shiwen; Juang, Chi-Mou; Hung, Chien-Fu; Hannaman, Drew; Saunders, John R; Wu, T-C; Pai, Sara I

    2009-09-01

    DNA vaccines are an attractive approach to eliciting antigen-specific immunity. Intracellular targeting of tumor antigens through its linkage to immunostimulatory molecules such as calreticulin (CRT) can improve antigen processing and presentation through the MHC class I pathway and increase cytotoxic CD8+ T cell production. However, even with these enhancements, the efficacy of such immunotherapeutic strategies is dependent on the identification of an effective route and method of DNA administration. Electroporation and gene gun-mediated particle delivery are leading methods of DNA vaccine delivery that can generate protective and therapeutic levels of immune responses in experimental models. In this study, we perform a head-to-head comparison of three methods of vaccination--conventional intramuscular injection, electroporation-mediated intramuscular delivery, and epidermal gene gun-mediated particle delivery--in the ability to generate antigen-specific cytotoxic CD8+ T cell responses as well as anti-tumor immune responses against an HPV-16 E7 expressing tumor cell line using the pNGVL4a-CRT/E7(detox) DNA vaccine. Vaccination via electroporation generated the highest number of E7-specific cytotoxic CD8+ T cells, which correlated to improved outcomes in the treatment of growing tumors. In addition, we demonstrate that electroporation results in significantly higher levels of circulating protein compared to gene gun or intramuscular vaccination, which likely enhances calreticulin's role as a local tumor anti-angiogenesis agent. We conclude that electroporation is a promising method for delivery of HPV DNA vaccines and should be considered for DNA vaccine delivery in human clinical trials. PMID:19622402

  2. Immune responses in DNA vaccine formulated with PMMA following immunization and after challenge with Leishmania major.

    PubMed

    Zarrati, Somayeh; Mahdavi, Mehdi; Tabatabaie, Fatemeh

    2016-06-01

    Leishmaniasis is a major infectious disease caused by protozoan parasites of the genus Leishmania. Despite of many efforts toward vaccine against Leishmania no effective vaccine has been approved yet. DNA vaccines can generate more powerful and broad immune responses than conventional vaccines. In order to increase immunity, the DNA vaccine has been supplemented with adjuvant. In this study a new nano-vaccine containing TSA recombinant plasmid and poly(methylmethacrylate) nanoparticles (act as adjuvant) was designed and its immunogenicity tested on BALB/c mouse. After three intramuscular injection of nano-vaccine (100 μg), the recombinant TSA protein (20 μg) was injected subcutaneously. Finally as a challenge animals were infected by Leishmania major. After the last injection of nano-vaccine, after protein booster injection, and also after challenge, cellular immune and antibody responses were evaluated by ELISA method. The findings of this study showed the new nano-vaccine was capable of induction both cytokines secretion and specific antibody responses, but predominant Th1 immune response characterized by IFN-γ production compared to control groups. Moreover, results revealed that nano-vaccine was effective in reducing parasite burden in the spleen of Leishmania major-infected BALB/c mice. Base on results, current candidate vaccine has potency for further studies. PMID:27413316

  3. Immune response induced by candidate Sarcoptes scabiei var. cuniculi DNA vaccine encoding paramyosin in mice.

    PubMed

    Gu, Xiaobin; Xie, Yue; Wang, Shuxian; Peng, Xuerong; Lai, Songjia; Yang, Guangyou

    2014-07-01

    Sarcoptes scabiei is the causal agent of the highly contagious disease sarcoptic mange (scabies) that affects animals and humans worldwide. An increasing number of cases of treatment failure is being reported because of drug resistance. The development of a specific vaccine would be a sustainable option for control of this disease. In this study, we cloned and expressed a S. scabiei gene encoding paramyosin (PAR) and investigated the immune response elicited by DNA encoding PAR in mice. The ability of the DNA vaccine to express antigen in COS-7 cells was confirmed by RT-PCR and IFA. The immune response induced by DNA vaccine was investigated by ELISA, splenocyte proliferation assay, and cytokine production assay. Compared to the pVAX1 control group, the PAR DNA vaccination group showed the higher levels of IgG, IgG1, IgG2a, IgE, IgM, stronger lymphocyte proliferation in mouse spleen, and larger production of IL-2, IL-4, IL-5, and IFN-γ in the supernatant of cultures from splenocytes. These results indicated that the PAR DNA vaccine induced a mixed Th1/Th2 response in mice. In conclusion, our results revealed that the S. scabiei PAR DNA vaccine induced both a humoral and cellular immune response, which would provide basic data for the further study to develop an effective vaccine against sarcoptic mange. PMID:24729069

  4. Enhancing the DNA Patent Database

    SciTech Connect

    Walters, LeRoy B.

    2008-02-18

    Final Report on Award No. DE-FG0201ER63171 Principal Investigator: LeRoy B. Walters February 18, 2008 This project successfully completed its goal of surveying and reporting on the DNA patenting and licensing policies at 30 major U.S. academic institutions. The report of survey results was published in the January 2006 issue of Nature Biotechnology under the title “The Licensing of DNA Patents by US Academic Institutions: An Empirical Survey.” Lori Pressman was the lead author on this feature article. A PDF reprint of the article will be submitted to our Program Officer under separate cover. The project team has continued to update the DNA Patent Database on a weekly basis since the conclusion of the project. The database can be accessed at dnapatents.georgetown.edu. This database provides a valuable research tool for academic researchers, policymakers, and citizens. A report entitled Reaping the Benefits of Genomic and Proteomic Research: Intellectual Property Rights, Innovation, and Public Health was published in 2006 by the Committee on Intellectual Property Rights in Genomic and Protein Research and Innovation, Board on Science, Technology, and Economic Policy at the National Academies. The report was edited by Stephen A. Merrill and Anne-Marie Mazza. This report employed and then adapted the methodology developed by our research project and quoted our findings at several points. (The full report can be viewed online at the following URL: http://www.nap.edu/openbook.php?record_id=11487&page=R1). My colleagues and I are grateful for the research support of the ELSI program at the U.S. Department of Energy.

  5. Preparation, characterization, and in ovo vaccination of dextran-spermine nanoparticle DNA vaccine coexpressing the fusion and hemagglutinin genes against Newcastle disease.

    PubMed

    Firouzamandi, Masoumeh; Moeini, Hassan; Hosseini, Seyed Davood; Bejo, Mohd Hair; Omar, Abdul Rahman; Mehrbod, Parvaneh; El Zowalaty, Mohamed E; Webster, Thomas J; Ideris, Aini

    2016-01-01

    Plasmid DNA (pDNA)-based vaccines have emerged as effective subunit vaccines against viral and bacterial pathogens. In this study, a DNA vaccine, namely plasmid internal ribosome entry site-HN/F, was applied in ovo against Newcastle disease (ND). Vaccination was carried out using the DNA vaccine alone or as a mixture of the pDNA and dextran-spermine (D-SPM), a nanoparticle used for pDNA delivery. The results showed that in ovo vaccination with 40 μg pDNA/egg alone induced high levels of antibody titer (P<0.05) in specific pathogen-free (SPF) chickens at 3 and 4 weeks postvaccination compared to 2 weeks postvaccination. Hemagglutination inhibition (HI) titer was not significantly different between groups injected with 40 μg pDNA + 64 μg D-SPM and 40 μg pDNA at 4 weeks postvaccination (P>0.05). Higher antibody titer was observed in the group immunized with 40 μg pDNA/egg at 4 weeks postvaccination. The findings also showed that vaccination with 40 μg pDNA/egg alone was able to confer protection against Newcastle disease virus strain NDIBS002 in two out of seven SPF chickens. Although the chickens produced antibody titers 3 weeks after in ovo vaccination, it was not sufficient to provide complete protection to the chickens from lethal viral challenge. In addition, vaccination with pDNA/D-SPM complex did not induce high antibody titer when compared with naked pDNA. Therefore, it was concluded that DNA vaccination with plasmid internal ribosome entry site-HN/F can be suitable for in ovo application against ND, whereas D-SPM is not recommended for in ovo gene delivery. PMID:26834470

  6. Preparation, characterization, and in ovo vaccination of dextran-spermine nanoparticle DNA vaccine coexpressing the fusion and hemagglutinin genes against Newcastle disease

    PubMed Central

    Firouzamandi, Masoumeh; Moeini, Hassan; Hosseini, Seyed Davood; Bejo, Mohd Hair; Omar, Abdul Rahman; Mehrbod, Parvaneh; El Zowalaty, Mohamed E; Webster, Thomas J; Ideris, Aini

    2016-01-01

    Plasmid DNA (pDNA)-based vaccines have emerged as effective subunit vaccines against viral and bacterial pathogens. In this study, a DNA vaccine, namely plasmid internal ribosome entry site-HN/F, was applied in ovo against Newcastle disease (ND). Vaccination was carried out using the DNA vaccine alone or as a mixture of the pDNA and dextran-spermine (D-SPM), a nanoparticle used for pDNA delivery. The results showed that in ovo vaccination with 40 μg pDNA/egg alone induced high levels of antibody titer (P<0.05) in specific pathogen-free (SPF) chickens at 3 and 4 weeks postvaccination compared to 2 weeks postvaccination. Hemagglutination inhibition (HI) titer was not significantly different between groups injected with 40 μg pDNA + 64 μg D-SPM and 40 μg pDNA at 4 weeks postvaccination (P>0.05). Higher antibody titer was observed in the group immunized with 40 μg pDNA/egg at 4 weeks postvaccination. The findings also showed that vaccination with 40 μg pDNA/egg alone was able to confer protection against Newcastle disease virus strain NDIBS002 in two out of seven SPF chickens. Although the chickens produced antibody titers 3 weeks after in ovo vaccination, it was not sufficient to provide complete protection to the chickens from lethal viral challenge. In addition, vaccination with pDNA/D-SPM complex did not induce high antibody titer when compared with naked pDNA. Therefore, it was concluded that DNA vaccination with plasmid internal ribosome entry site-HN/F can be suitable for in ovo application against ND, whereas D-SPM is not recommended for in ovo gene delivery. PMID:26834470

  7. Construction of Eimeria tenella multi-epitope DNA vaccines and their protective efficacies against experimental infection.

    PubMed

    Song, Xiaokai; Xu, Lixin; Yan, Ruofeng; Huang, Xinmei; Li, Xiangrui

    2015-08-15

    The search for effective vaccines against chicken coccidiosis remains a challenge because of the complex organisms with multiple life cycle stages of Eimeria. Combination of T-cell epitopes from different stages of Eimeria life cycle could be an optimal strategy to overcome the antigen complexity of the parasite. In this study, 4 fragments with concentrated T-cell epitopes from the sporozoite antigen SO7 and the merozoite antigen MZ5-7 of Eimeria tenella were cloned into eukaryotic expression vector pVAX1 in different forms, with or without chicken cytokines IL-2 or IFN-γ genes as genetic adjuvants, to construct multistage, multi-epitope DNA vaccines against Eimeria tenella. Transcription and expression of the multi-epitope DNA vaccines in vivo were detected by reverse transcription-PCR (RT-PCR) and Western blot. On the basis of survival rate, lesion score, body weight gain, oocyst decrease ratio and the anti-coccidial index (ACI), Animal experiments were carried out to evaluate the protective efficacy against Eimeria tenella. Results showed the constructed DNA vaccines were transcribed and translated successfully in vivo. Animal experiment showed that the multi-epitopes DNA vaccines were more effective to stimulate immune response than single fragment. Compared with the DNA vaccines composed with less T-cell epitopes, DNA vaccine pVAX1-m1-m2-s1-s2 containing 4 fragments with concentrated T-epitopes provided the highest ACI of 180.39. DNA vaccines composed of antigens from two developmental stages were more effective than the single-stage ones. Especially DNA vaccine pVAX1-m1-m2-s1-s2 provided the most effective protection with the ACI of 180.39. Furthermore, cytokines IL-2 or IFN-γ could improve the efficacy of the multi-epitope DNA vaccines significantly. Overall, pVAX1-m1-m2-s1-s2-IFN-γ provided the most effective protection with the ACI of 189.92. The multi-epitope DNA vaccines revealed in this study provide new candidates for Eimeria vaccine development

  8. DNA is an efficient booster of dendritic cell-based vaccine

    PubMed Central

    Li, Jinyao; Valentin, Antonio; Beach, Rachel Kelly; Alicea, Candido; Felber, Barbara K; Pavlakis, George N

    2015-01-01

    DC-based therapeutic vaccines as a promising strategy against chronic infections and cancer have been validated in several clinical trials. However, DC-based vaccines are complex and require many in vitro manipulations, which makes this a personalized and expensive therapeutic approach. In contrast, DNA-based vaccines have many practical advantages including simplicity, low cost of manufacturing and potent immunogenicity already proven in non-human primates and humans. In this study, we explored whether DC-based vaccines can be simplified by the addition of plasmid DNA as prime or boost to achieve robust CD8-mediated immune responses. We compared the cellular immunity induced in BALB/c and C57BL/6 mice by DC vaccines, loaded either with peptides or optimized SIV Env DNA, and plasmid DNA-based vaccines delivered by electroporation (EP). We found that mature DC loaded with peptides (P-mDC) induced the highest CD8+ T cell responses in both strains of mice, but those responses were significantly higher in the C57BL/6 model. A heterologous prime-boost strategy (P-DC prime-DNA boost) induced CD8+ T cell responses similar to those obtained by the P-DC vaccine. Importantly, this strategy elicited robust polyfunctional T cells as well as highest antigen-specific central memory CD8+ T cells in C57BL/6 mice, suggesting long-term memory responses. These results indicate that a DC-based vaccine in combination with DNA in a heterologous DC prime-DNA boost strategy has potential as a repeatedly administered vaccine. PMID:26125100

  9. Smallpox DNA vaccine delivered by novel skin electroporation device protects mice against intranasal poxvirus challenge.

    PubMed

    Hooper, Jay W; Golden, Joseph W; Ferro, Anthony M; King, Alan D

    2007-02-26

    Previously, we demonstrated that an experimental smallpox DNA vaccine comprised of four vaccinia virus genes (4pox) administered by gene gun elicited protective immunity in mice challenged with vaccinia virus, and in nonhuman primates challenged with monkeypox virus (Hooper JW, et al. Smallpox DNA vaccine protects nonhuman primates against lethal monkeypox. J Virol 2004;78:4433-43). Here, we report that this 4pox DNA vaccine can be efficiently delivered by a novel method involving skin electroporation using plasmid DNA-coated microneedle arrays. Mice vaccinated with the 4pox DNA vaccine mounted robust antibody responses against the four immunogens-of-interest, including neutralizing antibody titers that were greater than those elicited by the traditional live virus vaccine administered by scarification. Moreover, vaccinated mice were completely protected against a lethal (>10LD(50)) intranasal challenge with vaccinia virus strain IHD-J. To our knowledge, this is the first demonstration of a protective immune response being elicited by microneedle-mediated skin electroporation. PMID:17240007

  10. Multiple factors affect immunogenicity of DNA plasmid HIV vaccines in human clinical trials

    PubMed Central

    Jin, Xia; Morgan, Cecilia; Yu, Xuesong; DeRosa, Stephen; Tomaras, Georgia D.; Montefiori, David C.; Kublin, James; Corey, Larry; Keefer, Michael C.

    2015-01-01

    Plasmid DNA vaccines have been licensed for use in domesticated animals because of their excellent immunogenicity, but none have yet been licensed for use in humans. Here we report a retrospective analysis of 1218 healthy human volunteers enrolled in 10 phase I clinical trials in which DNA plasmids encoding HIV antigens were administered. Elicited T-cell immune responses were quantified by validated intracellular cytokine staining (ICS) stimulated with HIV peptide pools. HIV-specific binding and neutralizing antibody activities were also analyzed using validated assays. Results showed that, in the absence of adjuvants and boosting with alternative vaccines, DNA vaccines elicited CD8+ and CD4+ T-cell responses in an average of 13.3% (95% CI: 9.8% to 17.8%) and 37.7% (95% CI: 31.9% to 43.8%) of vaccine recipients, respectively. Three vaccinations (versus 2) improved the proportion of subjects with antigen-specific CD8+ responses (p=0.02), as did increased DNA dosage (p=0.007). Furthermore, female gender and participants having a lower Body Mass Index were independently associated with higher CD4+ T-cell response rate (p=0.001 and p=0.008, respectively). These vaccines elicited minimal neutralizing and binding antibody responses. These findings of the immunogenicity of HIV DNA vaccines in humans can provide guidance for future clinical trials. PMID:25820067