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Increasing the Vaccine Potential of Live M. bovis BCG by Coadministration with Plasmid DNA Encoding a Tuberculosis Prototype Antigen.

Bruffaerts N, Romano M, Denis O, Jurion F, Huygen K - Vaccines (Basel) (2014)

Bottom Line: Strongly increased T- and B-cell responses were observed with this protocol in C57BL/6 mice when compared to the administration of only BCG or in combination with an empty pDNA vector, as measured by Th1-type spleen cell cytokine secretion, specific IgG antibodies, as well as specific IFN-γ producing/cytolytic-CD8⁺ T-cells.Moreover, we observed a bystander activation induced by the coding plasmid, resulting in increased immune responses against other non-plasmid encoded, but BCG-expressed, antigens.In all, these results provide a proof of concept for a new TB vaccine, based on a BCG-plasmid DNA combination.

View Article: PubMed Central - PubMed

Affiliation: Scientific Institute of Public Health, Communicable and Infectious Diseases, Immunology, Brussels 1180, Belgium. nicolas.bruffaerts@wiv-isp.be.

ABSTRACT
The attenuated live M. bovis Bacille-Calmette-Guérin (BCG) is still the sole vaccine used against tuberculosis, but confers only variable efficacy against adult pulmonary tuberculosis (TB). Though no clear explanation for this limited efficacy has been given, different hypotheses have been advanced, such as the waning of memory T-cell responses, a reduced antigenic repertoire and the inability to induce effective CD8⁺ T-cell responses, which are known to be essential for latent tuberculosis control. In this study, a new BCG-based vaccination protocol was studied, in which BCG was formulated in combination with a plasmid DNA vaccine. As BCG is routinely administered to neonates, we have evaluated a more realistic approach of a simultaneous intradermal coadministration of BCG with pDNA encoding the prototype antigen, PPE44. Strongly increased T- and B-cell responses were observed with this protocol in C57BL/6 mice when compared to the administration of only BCG or in combination with an empty pDNA vector, as measured by Th1-type spleen cell cytokine secretion, specific IgG antibodies, as well as specific IFN-γ producing/cytolytic-CD8⁺ T-cells. Moreover, we observed a bystander activation induced by the coding plasmid, resulting in increased immune responses against other non-plasmid encoded, but BCG-expressed, antigens. In all, these results provide a proof of concept for a new TB vaccine, based on a BCG-plasmid DNA combination.

No MeSH data available.


Related in: MedlinePlus

BCG/pDNA co-vaccination protocol. Priming was performed in adult mice with a mix of 106 CFU live M. bovis BCG and 100 µg coding or non-coding plasmid DNA by the intradermal route in the tail (ID). After 3 weeks of resting, two further boosts at 3-week intervals were administered with 100 μg of plasmid at the same site. Two additional control groups consisted of one prime-immunized intradermally only with BCG (106 CFU/mouse) and another intramuscularly (IM) immunized three times only with 100 µg coding plasmid at 3-week intervals. Animals were sacrificed 3 weeks after the second DNA boost to analyze cellular immune responses in spleen and inguinal lymph nodes and humoral responses in serum.
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vaccines-02-00181-f001: BCG/pDNA co-vaccination protocol. Priming was performed in adult mice with a mix of 106 CFU live M. bovis BCG and 100 µg coding or non-coding plasmid DNA by the intradermal route in the tail (ID). After 3 weeks of resting, two further boosts at 3-week intervals were administered with 100 μg of plasmid at the same site. Two additional control groups consisted of one prime-immunized intradermally only with BCG (106 CFU/mouse) and another intramuscularly (IM) immunized three times only with 100 µg coding plasmid at 3-week intervals. Animals were sacrificed 3 weeks after the second DNA boost to analyze cellular immune responses in spleen and inguinal lymph nodes and humoral responses in serum.

Mentions: A schematic timeline representing the experimental protocol is depicted in Figure 1. Priming was performed in adult mice by the intradermal route (ID) with a fresh mix of 106 CFU of live M. bovis BCG (strain Pasteur GL2) and 100 µg of non-coding plasmid DNA (namely, pV1J.ns-tPA [28]), or plasmid DNA encoding PPE44 (namely, pV1J.ns-tPA-PPE44) or plasmid DNA encoding OVA (namely, pCI-OVA, a generous gift of Dr. Joseph Thalhamer and Dr. Richard Weiss [29]). Intradermal injections were carried out 1–2 cm distal from the tail base with a maximum total volume of 100 µL. After 3 weeks of resting, two further intradermal boosts at 3-week intervals were administered with the same 100 μg plasmid at the same site. Two additional control groups consisted of mice primed intradermally with only BCG (106 CFU/mouse) and of mice immunized intramuscularly (IM) three times with 100 µg coding plasmid at 3-week intervals. Intramuscular injections were performed in both quadriceps muscles with 2 × 50 μL, after anesthesia with ketamine/xylazine.


Increasing the Vaccine Potential of Live M. bovis BCG by Coadministration with Plasmid DNA Encoding a Tuberculosis Prototype Antigen.

Bruffaerts N, Romano M, Denis O, Jurion F, Huygen K - Vaccines (Basel) (2014)

BCG/pDNA co-vaccination protocol. Priming was performed in adult mice with a mix of 106 CFU live M. bovis BCG and 100 µg coding or non-coding plasmid DNA by the intradermal route in the tail (ID). After 3 weeks of resting, two further boosts at 3-week intervals were administered with 100 μg of plasmid at the same site. Two additional control groups consisted of one prime-immunized intradermally only with BCG (106 CFU/mouse) and another intramuscularly (IM) immunized three times only with 100 µg coding plasmid at 3-week intervals. Animals were sacrificed 3 weeks after the second DNA boost to analyze cellular immune responses in spleen and inguinal lymph nodes and humoral responses in serum.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4494193&req=5

vaccines-02-00181-f001: BCG/pDNA co-vaccination protocol. Priming was performed in adult mice with a mix of 106 CFU live M. bovis BCG and 100 µg coding or non-coding plasmid DNA by the intradermal route in the tail (ID). After 3 weeks of resting, two further boosts at 3-week intervals were administered with 100 μg of plasmid at the same site. Two additional control groups consisted of one prime-immunized intradermally only with BCG (106 CFU/mouse) and another intramuscularly (IM) immunized three times only with 100 µg coding plasmid at 3-week intervals. Animals were sacrificed 3 weeks after the second DNA boost to analyze cellular immune responses in spleen and inguinal lymph nodes and humoral responses in serum.
Mentions: A schematic timeline representing the experimental protocol is depicted in Figure 1. Priming was performed in adult mice by the intradermal route (ID) with a fresh mix of 106 CFU of live M. bovis BCG (strain Pasteur GL2) and 100 µg of non-coding plasmid DNA (namely, pV1J.ns-tPA [28]), or plasmid DNA encoding PPE44 (namely, pV1J.ns-tPA-PPE44) or plasmid DNA encoding OVA (namely, pCI-OVA, a generous gift of Dr. Joseph Thalhamer and Dr. Richard Weiss [29]). Intradermal injections were carried out 1–2 cm distal from the tail base with a maximum total volume of 100 µL. After 3 weeks of resting, two further intradermal boosts at 3-week intervals were administered with the same 100 μg plasmid at the same site. Two additional control groups consisted of mice primed intradermally with only BCG (106 CFU/mouse) and of mice immunized intramuscularly (IM) three times with 100 µg coding plasmid at 3-week intervals. Intramuscular injections were performed in both quadriceps muscles with 2 × 50 μL, after anesthesia with ketamine/xylazine.

Bottom Line: Strongly increased T- and B-cell responses were observed with this protocol in C57BL/6 mice when compared to the administration of only BCG or in combination with an empty pDNA vector, as measured by Th1-type spleen cell cytokine secretion, specific IgG antibodies, as well as specific IFN-γ producing/cytolytic-CD8⁺ T-cells.Moreover, we observed a bystander activation induced by the coding plasmid, resulting in increased immune responses against other non-plasmid encoded, but BCG-expressed, antigens.In all, these results provide a proof of concept for a new TB vaccine, based on a BCG-plasmid DNA combination.

View Article: PubMed Central - PubMed

Affiliation: Scientific Institute of Public Health, Communicable and Infectious Diseases, Immunology, Brussels 1180, Belgium. nicolas.bruffaerts@wiv-isp.be.

ABSTRACT
The attenuated live M. bovis Bacille-Calmette-Guérin (BCG) is still the sole vaccine used against tuberculosis, but confers only variable efficacy against adult pulmonary tuberculosis (TB). Though no clear explanation for this limited efficacy has been given, different hypotheses have been advanced, such as the waning of memory T-cell responses, a reduced antigenic repertoire and the inability to induce effective CD8⁺ T-cell responses, which are known to be essential for latent tuberculosis control. In this study, a new BCG-based vaccination protocol was studied, in which BCG was formulated in combination with a plasmid DNA vaccine. As BCG is routinely administered to neonates, we have evaluated a more realistic approach of a simultaneous intradermal coadministration of BCG with pDNA encoding the prototype antigen, PPE44. Strongly increased T- and B-cell responses were observed with this protocol in C57BL/6 mice when compared to the administration of only BCG or in combination with an empty pDNA vector, as measured by Th1-type spleen cell cytokine secretion, specific IgG antibodies, as well as specific IFN-γ producing/cytolytic-CD8⁺ T-cells. Moreover, we observed a bystander activation induced by the coding plasmid, resulting in increased immune responses against other non-plasmid encoded, but BCG-expressed, antigens. In all, these results provide a proof of concept for a new TB vaccine, based on a BCG-plasmid DNA combination.

No MeSH data available.


Related in: MedlinePlus