Levels of CD4+IFN-γ+ T cells induced by ex vivo stimul

A new recombinant BCG vaccine induces specific Th17 and Th1 effector cells with higher protective efficacy against tuberculosis. da Costa AC, Costa-Júnior Ade O, de Oliveira FM, Nogueira SV, Rosa JD, Resende DP, Kipnis A, Junqueira-Kipnis AP - PLoS ONE (2014) Bottom Line: Consequently, several groups have pursued the development of a new vaccine with a superior protective capacity to that of BCG.Vaccinated mice presented higher amounts of Th1, Th17, and polyfunctional specific T cells. rBCG-CMX vaccination reduced the extension of lung lesions caused by challenge with Mtb as well as the lung bacterial load.In addition, when this vaccine was used in a prime-boost strategy together with rCMX, the lung bacterial load was lower than the result observed by BCG vaccination. View Article: PubMed Central - PubMed Affiliation: Laboratório de Imunopatologia das Doenças Infecciosas, Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, Goiás, Brazil. ABSTRACT Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb) that is a major public health problem. The vaccine used for TB prevention is Mycobacterium bovis bacillus Calmette-Guérin (BCG), which provides variable efficacy in protecting against pulmonary TB among adults. Consequently, several groups have pursued the development of a new vaccine with a superior protective capacity to that of BCG. Here we constructed a new recombinant BCG (rBCG) vaccine expressing a fusion protein (CMX) composed of immune dominant epitopes from Ag85C, MPT51, and HspX and evaluated its immunogenicity and protection in a murine model of infection. The stability of the vaccine in vivo was maintained for up to 20 days post-vaccination. rBCG-CMX was efficiently phagocytized by peritoneal macrophages and induced nitric oxide (NO) production. Following mouse immunization, this vaccine induced a specific immune response in cells from lungs and spleen to the fusion protein and to each of the component recombinant proteins by themselves. Vaccinated mice presented higher amounts of Th1, Th17, and polyfunctional specific T cells. rBCG-CMX vaccination reduced the extension of lung lesions caused by challenge with Mtb as well as the lung bacterial load. In addition, when this vaccine was used in a prime-boost strategy together with rCMX, the lung bacterial load was lower than the result observed by BCG vaccination. This study describes the creation of a new promising vaccine for TB that we hope will be used in further studies to address its safety before proceeding to clinical trials. Show MeSH Major BCG Vaccine/immunology* Th1 Cells/cytology/immunology* Th17 Cells/cytology/immunology* Tuberculosis/immunology/prevention & control* Minor Animals Antigens, Bacterial/genetics/metabolism Bacterial Load/immunology Bacterial Proteins/genetics/metabolism CD4-Positive T-Lymphocytes/cytology/immunology Cytokines/metabolism Epitopes/immunology Female Lung/metabolism/microbiology/pathology Macrophages/cytology/immunology Mice Mice, Inbred BALB C Mycobacterium tuberculosis/immunology/metabolism/pathogenicity Nitric Oxide/metabolism Peritoneum/cytology Phagocytosis Recombinant Fusion Proteins/biosynthesis/genetics/immunology Spleen/immunology/metabolism Related in: MedlinePlus	© Copyright Policy Related In: Results - Collection License Show All Figures getmorefigures.php?uid=PMC4232451&req=5 pone-0112848-g005: Levels of CD4+IFN-γ+ T cells induced by ex vivo stimulation with recombinant Ag85, MPT51, and HspX.Thirty days after vaccination, lung and spleen suspensions were stimulated exvivo with Ag85, MPT51, HspX, or medium alone. The number of cells positive for CD4 and IFN-γ was determined by flow cytometry. Lymphocytes were selected based on size and granularity. Gates were set to analyze CD4+ T cells, and then the fluorescence of antibodies detecting IFN-γ+ cells was recorded. (A–B) Spleen cells from mice vaccinated with (A) rBCG-CMX or (B) BCG. (C–D) Lung cells from mice vaccinated with (C) rBCG-CMX or (D) BCG. In A and C, all results were different from the medium stimulation. These data are representative of two independent experiments (N = 6, p<0.05). Mentions:* We next questioned which protein(s) of the recombinant CMX fusion protein could contribute to the induction of IFN-γ (Fig. 5) and/or IL-17 (Fig. 6) by CD4+ T lymphocytes. As depicted in Figure 5, exvivo stimulation of spleen and lung cells from rBCG-CMX vaccinated mice with Ag85, MPT51, or HspX all specifically induced CD4+IFN-γ+ cells (Figs. 5A and C, p<0.05). A significantly higher number of spleen cells were observed responding to MPT51 than to Ag85 or HspX. In mice vaccinated with BCG, cells that were CD4+IFN-γ+ were only induced in response to Ag85 and MPT51 stimulation, but not in response to HspX. Additionally, these CD4+IFN-γ+ cells were induced to a lesser extent than in the spleen or lung cells from mice vaccinated with rBCG-CMX (Figs. 5B and D, p<0.05).

A new recombinant BCG vaccine induces specific Th17 and Th1 effector cells with higher protective efficacy against tuberculosis.

da Costa AC, Costa-Júnior Ade O, de Oliveira FM, Nogueira SV, Rosa JD, Resende DP, Kipnis A, Junqueira-Kipnis AP - PLoS ONE (2014)

Bottom Line: Consequently, several groups have pursued the development of a new vaccine with a superior protective capacity to that of BCG.Vaccinated mice presented higher amounts of Th1, Th17, and polyfunctional specific T cells. rBCG-CMX vaccination reduced the extension of lung lesions caused by challenge with Mtb as well as the lung bacterial load.In addition, when this vaccine was used in a prime-boost strategy together with rCMX, the lung bacterial load was lower than the result observed by BCG vaccination.

View Article: PubMed Central - PubMed

Affiliation: Laboratório de Imunopatologia das Doenças Infecciosas, Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, Goiás, Brazil.

ABSTRACT

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb) that is a major public health problem. The vaccine used for TB prevention is Mycobacterium bovis bacillus Calmette-Guérin (BCG), which provides variable efficacy in protecting against pulmonary TB among adults. Consequently, several groups have pursued the development of a new vaccine with a superior protective capacity to that of BCG. Here we constructed a new recombinant BCG (rBCG) vaccine expressing a fusion protein (CMX) composed of immune dominant epitopes from Ag85C, MPT51, and HspX and evaluated its immunogenicity and protection in a murine model of infection. The stability of the vaccine in vivo was maintained for up to 20 days post-vaccination. rBCG-CMX was efficiently phagocytized by peritoneal macrophages and induced nitric oxide (NO) production. Following mouse immunization, this vaccine induced a specific immune response in cells from lungs and spleen to the fusion protein and to each of the component recombinant proteins by themselves. Vaccinated mice presented higher amounts of Th1, Th17, and polyfunctional specific T cells. rBCG-CMX vaccination reduced the extension of lung lesions caused by challenge with Mtb as well as the lung bacterial load. In addition, when this vaccine was used in a prime-boost strategy together with rCMX, the lung bacterial load was lower than the result observed by BCG vaccination. This study describes the creation of a new promising vaccine for TB that we hope will be used in further studies to address its safety before proceeding to clinical trials.

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Levels of CD4+IFN-γ+ T cells induced by ex vivo stimulation with recombinant Ag85, MPT51, and HspX.Thirty days after vaccination, lung and spleen suspensions were stimulated exvivo with Ag85, MPT51, HspX, or medium alone. The number of cells positive for CD4 and IFN-γ was determined by flow cytometry. Lymphocytes were selected based on size and granularity. Gates were set to analyze CD4+ T cells, and then the fluorescence of antibodies detecting IFN-γ+ cells was recorded. (A–B) Spleen cells from mice vaccinated with (A) rBCG-CMX or (B) BCG. (C–D) Lung cells from mice vaccinated with (C) rBCG-CMX or (D) BCG. In A and C, all results were different from the medium stimulation. These data are representative of two independent experiments (N = 6, *p<0.05).

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pone-0112848-g005: Levels of CD4+IFN-γ+ T cells induced by ex vivo stimulation with recombinant Ag85, MPT51, and HspX.Thirty days after vaccination, lung and spleen suspensions were stimulated exvivo with Ag85, MPT51, HspX, or medium alone. The number of cells positive for CD4 and IFN-γ was determined by flow cytometry. Lymphocytes were selected based on size and granularity. Gates were set to analyze CD4+ T cells, and then the fluorescence of antibodies detecting IFN-γ+ cells was recorded. (A–B) Spleen cells from mice vaccinated with (A) rBCG-CMX or (B) BCG. (C–D) Lung cells from mice vaccinated with (C) rBCG-CMX or (D) BCG. In A and C, all results were different from the medium stimulation. These data are representative of two independent experiments (N = 6, *p<0.05).

Mentions: We next questioned which protein(s) of the recombinant CMX fusion protein could contribute to the induction of IFN-γ (Fig. 5) and/or IL-17 (Fig. 6) by CD4+ T lymphocytes. As depicted in Figure 5, exvivo stimulation of spleen and lung cells from rBCG-CMX vaccinated mice with Ag85, MPT51, or HspX all specifically induced CD4+IFN-γ+ cells (Figs. 5A and C, p<0.05). A significantly higher number of spleen cells were observed responding to MPT51 than to Ag85 or HspX. In mice vaccinated with BCG, cells that were CD4+IFN-γ+ were only induced in response to Ag85 and MPT51 stimulation, but not in response to HspX. Additionally, these CD4+IFN-γ+ cells were induced to a lesser extent than in the spleen or lung cells from mice vaccinated with rBCG-CMX (Figs. 5B and D, p<0.05).