Improved Immunogenicity of a Vaccination Regimen Combining a DNA Vaccine Encoding Brucella melitensis Outer Membrane Protein 31 (Omp31) and Recombinant Omp31 Boosting

ABSTRACT In the present study, we report an attempt to improve the immunogenicity of the Omp31 antigen by a DNA prime-protein boost immunization regimen. We immunized BALB/c mice with an Omp31 DNA vaccine (pCIOmp31) followed by boosting with recombinant Omp31 (rOmp31) in incomplete Freund's adjuvant and characterized the resulting immune responses and the protective efficacy against Brucella ovis and B. melitensis infection. Immunoglobulin G1 (IgG1) and IgG2a titers were higher in sera from pCIOmp31/rOmp31-immunized mice than in sera from mice immunized with pCIOmp31 or rOmp31 alone. Splenocytes from pCIOmp31/rOmp31-immunized mice produced significantly higher levels of gamma interferon than did those from mice given rOmp31 alone. In contrast, interleukin 2 (IL-2) production levels were comparable between the two groups of immunized mice. Cells from all immunized mice produced undetectable levels of IL-4. Notably, rOmp31 stimulated IL-10 production in the pCIOmp31/rOmp31-immunized group but not in the pCIOmp31- or rOmp31-immunized group. Although the prime-boost regimen induced specific cytotoxic responses, these responses could not reach the levels achieved by the pCIOmp31 immunization. In conclusion, pCIOmp31 priming followed by rOmp31 boosting led to moderately improved protection against a challenge with B. ovis or B. melitensis.

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Improved Immunogenicity and Protective Efficacy of a Tuberculosis DNA Vaccine Encoding Ag85 by Protein Boosting

Infection and Immunity ◽

10.1128/iai.69.5.3041-3047.2001 ◽

2001 ◽

Vol 69 (5) ◽

pp. 3041-3047 ◽

Cited By ~ 144

Author(s):

Audrey Tanghe ◽

Sushila D'Souza ◽

Valérie Rosseels ◽

Olivier Denis ◽

Thomas H. M. Ottenhoff ◽

...

Keyword(s):

T Cells ◽

Dna Vaccine ◽

Protective Efficacy ◽

Interleukin 2 ◽

Relative Light Unit ◽

Dna Immunization ◽

Cytokine Responses ◽

Cytokine Analysis ◽

Protein Boost ◽

Ifn Γ

ABSTRACT C57BL/6 mice were vaccinated with plasmid DNA encoding Ag85 fromMycobacterium tuberculosis, with Ag85 protein in adjuvant, or with a combined DNA prime-protein boost regimen. While DNA immunization, as previously described, induced robust Th1-type cytokine responses, protein-in-adjuvant vaccination elicited very poor cytokine responses, which were 10-fold lower than those observed with DNA immunization alone. Injection of Ag85 DNA-primed mice with 30 to 100 μg of purified Ag85 protein in adjuvant increased the interleukin-2 and gamma interferon (IFN-γ) response in spleen two- to fourfold. Further, intracellular cytokine analysis by flow cytometry also showed an increase in IFN-γ-producing CD4+ T cells in DNA-primed–protein-boosted animals, compared to those that received only the DNA vaccination. Moreover, these responses appeared to be better sustained over time. Antibodies were readily produced by all three methods of immunization but were exclusively of the immunoglobulin G1 (IgG1) isotype following protein immunization in adjuvant and preferentially of the IgG2a isotype following DNA and DNA prime-protein boost vaccination. Finally, protein boosting increased the protective efficacy of the DNA vaccine against an intravenousM. tuberculosis H37Rv challenge infection, as measured by CFU or relative light unit counts in lungs 1 and 2 months after infection. The capacity of exogenously given protein to boost the DNA-primed vaccination effect underlines the dominant role of Th1-type CD4+ helper T cells in mediating protection.

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Highly Efficient Expression of Interleukin-2 under the Control of Rabbit β-Globin Intron II Gene Enhances Protective Immune Responses of Porcine Reproductive and Respiratory Syndrome (PRRS) DNA Vaccine in Pigs

PLoS ONE ◽

10.1371/journal.pone.0090326 ◽

2014 ◽

Vol 9 (3) ◽

pp. e90326 ◽

Cited By ~ 6

Author(s):

Yijun Du ◽

Yu Lu ◽

Xinglong Wang ◽

Jing Qi ◽

Jiyu Liu ◽

...

Keyword(s):

Immune Responses ◽

Dna Vaccine ◽

Interleukin 2 ◽

Highly Efficient ◽

Efficient Expression

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Protective efficacy of aTreponema pallidumGpd DNA vaccine vectored by chitosan nanoparticles and fused with interleukin-2

Canadian Journal of Microbiology ◽

10.1139/w11-115 ◽

2012 ◽

Vol 58 (2) ◽

pp. 117-123 ◽

Cited By ~ 10

Author(s):

Feijun Zhao ◽

Shiping Wang ◽

Xiaohong Zhang ◽

Weiming Gu ◽

Jian Yu ◽

...

Keyword(s):

Dna Vaccine ◽

Protective Efficacy ◽

Interleukin 2 ◽

Chitosan Nanoparticles

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A DNA Vaccine Prime Followed by a Liposome-Encapsulated Protein Boost Confers Enhanced Mucosal Immune Responses and Protection

The Journal of Immunology ◽

10.4049/jimmunol.180.9.6159 ◽

2008 ◽

Vol 180 (9) ◽

pp. 6159-6167 ◽

Cited By ~ 20

Author(s):

Kejian Yang ◽

Barbara J. Whalen ◽

Rebecca S. Tirabassi ◽

Liisa K. Selin ◽

Tatyana S. Levchenko ◽

...

Keyword(s):

Immune Responses ◽

Dna Vaccine ◽

Protein Boost ◽

Mucosal Immune Responses

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A BCR/ABL-hIL-2 DNA Vaccine Enhances the Immune Responses in BALB/c Mice

BioMed Research International ◽

10.1155/2013/136492 ◽

2013 ◽

Vol 2013 ◽

pp. 1-9 ◽

Cited By ~ 5

Author(s):

Yanan Qin ◽

Hongxia Tian ◽

Guanming Wang ◽

Chen Lin ◽

Yangqiu Li

Keyword(s):

Immune Responses ◽

Dna Vaccine ◽

Residual Disease ◽

Fusion Gene ◽

Interleukin 2 ◽

K562 Cells ◽

Serum Levels ◽

Muscle Tissues ◽

Cellular Immune

The use of a DNA vaccine encoding the BCR/ABL fusion gene is thought to be a promising approach for patients with chronic myeloid leukemia (CML) to eradicate minimal residual disease after treatment with chemotherapy or targeted therapy. In this study, our strategy employs genetic technology to create a DNA vaccine encoding the BCR/ABL fusion and human interleukin-2 (hIL-2) genes. The successfully constructed plasmids BCR/ABL-pIRES-hIL-2, BCR/ABL-pIRES, and pIRES-hIL-2 were delivered intramuscularly to BALB/c mice at 14-day intervals for three cycles. The transcription and expression of the BCR/ABL and hIL-2 genes were found in the injected muscle tissues. The interferon-γ(IFN-γ) serum levels were increased, and the splenic CD4+/CD8+T cell ratio was significantly decreased in the BCR/ABL-pIRES-hIL-2-injected mice. Furthermore, specific antibodies against K562 cells could be detected by indirect immunofluorescence. These results indicate that a DNA vaccine containing BCR/ABL and hIL-2 together may elicit increased in vivo humoral and cellular immune responses in BALB/c mice.

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Modulation of Antigen-Specific Humoral Responses in Rhesus Macaques by Using Cytokine cDNAs as DNA Vaccine Adjuvants

Journal of Virology ◽

10.1128/jvi.74.7.3427-3429.2000 ◽

2000 ◽

Vol 74 (7) ◽

pp. 3427-3429 ◽

Cited By ~ 63

Author(s):

Jong J. Kim ◽

Joo-Sung Yang ◽

Thomas C. VanCott ◽

Daniel J. Lee ◽

Kelledy H. Manson ◽

...

Keyword(s):

Immune Responses ◽

Dna Vaccine ◽

Rhesus Macaques ◽

Interleukin 2 ◽

Dna Immunization ◽

Vaccine Adjuvants ◽

Vaccine Strategy ◽

Humoral Immune ◽

Macaque Model ◽

Immunodeficiency Virus

ABSTRACT An important limitation of DNA immunization in nonhuman primates is the difficulty in generating high levels of antigen-specific antibody responses; strategies to enhance the level of immune responses to DNA immunization may be important in the further development of this vaccine strategy for humans. We approached this issue by testing the ability of molecular adjuvants to enhance the levels of immune responses generated by multicomponent DNA vaccines in rhesus macaques. Rhesus macaques were coimmunized intramuscularly with expression plasmids bearing genes encoding Th1 (interleukin 2 [IL-2] and gamma interferon)- or Th2 (IL-4)-type cytokines and DNA vaccine constructs encoding human immunodeficiency virus Env and Rev and simian immunodeficiency virus Gag and Pol proteins. We observed that the cytokine gene adjuvants (especially IL-2 and IL-4) significantly enhanced antigen-specific humoral immune responses in the rhesus macaque model. These results support the assumption that antigen-specific responses can be engineered to a higher and presumably more desirable level in rhesus macaques by genetic adjuvants.

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Evaluation of the immunogenicity and the protective efficacy in mice of a DNA vaccine encoding SP41 from Brucella melitensis

The Journal of Infection in Developing Countries ◽

10.3855/jidc.2296 ◽

2013 ◽

Vol 7 (04) ◽

pp. 329-337 ◽

Cited By ~ 3

Author(s):

Ayman Al-Mariri ◽

Abdul Qader Abbady

Keyword(s):

T Cell ◽

Dna Vaccine ◽

Mammalian Cells ◽

Brucella Melitensis ◽

Protective Efficacy ◽

Dna Vaccination ◽

Surface Proteins ◽

Host Immune System ◽

T Helper 1

Introduction: Brucella melitensis is a facultative intracellular Gram-negative bacterial pathogen that may enter the host via ingestion or inhalation, or through conjunctiva or skin abrasions. Some Brucella spp surface proteins (SPs) play an important role in bacterial adhesion and invasion and thus represent targets for the host immune system. Brucella spp surface protein with apparent molecular mass of 41 kDa interacts selectively with HeLa cells. Methodology: To evaluate the role of SP41 (41 kDa) as a DNA vaccine against Brucella spp., pCISP41, a plasmid construct for protein expression in mammalian cells, was established. Exogenous SP41 was detected in pCISP41-transfected Vero cell line by immune blotting using specific polyclonal antibody. The protective role of pCISP41 against B. melitensis 16M in mice was evaluated by measuring B and T cell responses in comparison to those achieved with attenuated B. melitensis Rev. 1 vaccine. Results: BALB/c mice injected with pCISP41 were able to develop SP41-specific serum immunoglobulin G (IgG) antibodies. In addition, splenocytes from DNA-SP41-vaccinated mice elicited a T-cell-proliferative response and also induced gamma interferon (IFN-γ) production, but not interleukin-5 (IL-5), suggesting the induction of a T-helper-1-dominated immune response. Vaccination with attenuated B. melitensis Rev.1 strain induced better protection levels than DNA vaccination with SP41 against B. melitensis 16M in mice. Conclusion: Such responses play an important role against intracellular infecting agents such as Brucella spp. Altogether, our data suggest that SP41 may represent a promising candidate for DNA vaccination against brucellosis, but more investigation to increase its protective efficacy should be done.

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