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12 results on '"Ag85A"'

1. Down regulation of RANTES in pleural site is associated with inhibition of antigen specific response in tuberculosis.

Author

Pydi SS, Ghousunnissa S, Devalraju KP, Ramaseri SS, Gaddam R, Auzumeedi SK, Vankayalapati R, and Valluri VL

Subjects
Adult, Aged, Biomarkers metabolism, Case-Control Studies, Chemokine CCL5 blood, Chemotaxis, Down-Regulation, Female, Host-Pathogen Interactions, Humans, Leukocytes, Mononuclear immunology, Leukocytes, Mononuclear microbiology, Male, Middle Aged, Pleural Effusion immunology, Pleural Effusion microbiology, Tuberculosis, Pleural immunology, Tuberculosis, Pleural microbiology, Young Adult, Acyltransferases immunology, Antigens, Bacterial immunology, Chemokine CCL5 metabolism, Leukocytes, Mononuclear metabolism, Mycobacterium tuberculosis immunology, Pleural Effusion metabolism, Tuberculosis, Pleural metabolism
Abstract

Tuberculosis is the most common infectious reason for death and a major cause of pleural effusion globally. To understand the role of chemokines in trafficking of cells during TB pleurisy, we studied the responses to MTB, Ag85A in cells from pleural fluids and peripheral blood. Patients with TB pleural effusions, malignant effusions and asymptomatic healthy controls were enrolled. High expression (p < 0.05) of IP-10, MCP-1, MIG, IL-8, IFN-γ and IL-23 were observed in pleural fluids of TB patients compared to their plasma where expression of RANTES was significantly higher (p < 0.05). On specific stimulation of PFMCs with Ag85A, expression of RANTES was significantly lower in TB compared to NTB patients. We also observed increased expression of T regs and PD1 on CD8+T cells in PFMC of TB patients. Though some of the inflammatory chemokine/cytokines were up-regulated in pleura of TB patients, antigenic stimulation failed to induce them indicating poor antigenic responses at the site. Low expression of RANTES might be a reason for decreased trafficking of cells to the site and dissemination of infection into pleural site. The pattern of RANTES expression in pleural fluid vs serum is interesting. The observations necessitate further studies to investigate the levels of RANTES for its potential biological relevance in TB immunity and its use as a biomarker for diagnosis of pleural TB., (Copyright © 2019. Published by Elsevier Ltd.)

Published
2019
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2. The mechanisms of Ag85A DNA vaccine activates RNA sensors through new signal transduction.

Author

Zhai J, Wang Q, Gao Y, Zhang R, Li S, Wei B, You Y, Sun X, and Lu C

Subjects
Animals, CRISPR-Cas Systems, Cell Line, Dendritic Cells, Female, Interferon-beta metabolism, Mice, Inbred C57BL, Signal Transduction, Acyltransferases genetics, Antigens, Bacterial genetics, RNA, Vaccines, DNA
Abstract

Low immunogenicity is one of the major problems limiting the clinical use for DNA vaccines, which makes it impossible to obtain a strong protective immune response after vaccination. In order to explore whether Ag85A DNA vaccine could mount more efficiently protective immune response through new RNA sensor and its signal transduction pathway of antigen presentation we designed and synthesized Ag85A gene fragment containing multiple points mutations and transfected the gene fragment into the dendritic cell line (DC2.4) by CRISPR/Cas9. Subsequently, we focused on the changes of RNA sensors RIG-I, Mda-5, and the downstream adaptors MAVS, IRF3, IRF7 and IFN-β. The results indicated the significant increases in the mRNA and protein expression of RNA sensors RIG-I, Mda-5 and related adaptors MAVS, IRF3, IRF7, and IFN-β in the mutant DC 2.4 cells. The flow cytometry results demonstrated that the expression of MHC II on the surface of DC 2.4 significantly increased when compared with that in control. Therefore, it is suggested that Ag85A mutant DNA could release immunogenic message through RNA sensors and related adaptors via non protein pathway. There is at least one RNA signal transduction pathway of Ag85A DNA in DC2.4 cell. The work provides a new mode of action for nucleic acid vaccine to improve immunogenicity and meaningful data for the better understanding of the mechanisms of DNA vaccine., (Copyright © 2017. Published by Elsevier B.V.)

Published
2018
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3. Evaluation of Immunogenicity and Protective Efficacy Elicited by Mycobacterium bovis BCG Overexpressing Ag85A Protein against Mycobacterium tuberculosis Aerosol Infection.

Author

Xu ZZ, Chen X, Hu T, Meng C, Wang XB, Rao Y, Zhang XM, Yin YL, Pan ZM, and Jiao XA

Subjects
Acyltransferases genetics, Animals, Antigens, Bacterial genetics, Bacterial Load immunology, Dendritic Cells immunology, Female, Interferon-gamma immunology, Lung microbiology, Lymph Nodes cytology, Lymph Nodes immunology, Mice, Mice, Inbred C57BL, Recombinant Proteins immunology, Spleen microbiology, Th1 Cells immunology, Tuberculosis prevention & control, Vaccination, Vaccines, Synthetic immunology, Acyltransferases immunology, Antibodies, Bacterial immunology, Antigens, Bacterial immunology, BCG Vaccine immunology, Mycobacterium bovis immunology, Mycobacterium tuberculosis immunology, Tuberculosis immunology
Abstract

Mycobacterium bovis bacillus Calmette-Guérin (BCG) is currently the only vaccine available for preventing tuberculosis (TB), however, BCG has varying success in preventing pulmonary TB. In this study, a recombinant BCG (rBCG::Ag85A) strain overexpressing the immunodominant Ag85A antigen was constructed, and its immunogenicity and protective efficacy were evaluated. Our results indicated that the Ag85A protein was successfully overexpressed in rBCG::Ag85A, and the Ag85A peptide-MHC complexes on draining lymph node dendritic cells of C57BL/6 mice infected with rBCG::Ag85A were detectable 4 h post-infection. The C57BL/6 mice infected with this strain had stronger antigen-specific interferon-gamma (IFN-γ) responses and higher antibody titers than those immunized with BCG, and the protective experiments showed that rBCG::Ag85A can enhance protection against Mycobacterium tuberculosis (M. tuberculosis) H37Rv infection compared to the BCG vaccine alone. Our results demonstrate the potential of rBCG::Ag85A as a candidate vaccine against TB.

Published
2016
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4. Development and characterization of guar gum nanoparticles for oral immunization against tuberculosis.

Author

Kaur M, Malik B, Garg T, Rath G, and Goyal AK

Subjects
Administration, Oral, Animals, Chemistry, Pharmaceutical, Drug Liberation, Immunoglobulin A blood, Immunoglobulin G blood, Mice, Inbred BALB C, Microscopy, Confocal, Mycobacterium tuberculosis immunology, Particle Size, Peyer's Patches immunology, Surface Properties, Tuberculosis immunology, Tuberculosis microbiology, Acyltransferases administration & dosage, Antigens, Bacterial administration & dosage, Drug Carriers chemistry, Galactans chemistry, Mannans chemistry, Nanoparticles chemistry, Plant Gums chemistry, Tuberculosis prevention & control, Tuberculosis Vaccines administration & dosage
Abstract

The main aim of this study was to develop an effective carrier system containing Ag85A-loaded guar gum nanoparticles for oral vaccination against tuberculosis. Nanoparticles were prepared by Nanoprecipitation method. The developed particles with mean diameter 895.5 ± 14.73 nm and high antigen entrapment seem to be optimum for oral vaccine delivery. The acid protection assay, Peyer's patch uptake study and in-vitro antigen study confirmed that the developed formulations can protect the antigen from harsh gastric environment and can safely deliver the antigen to the intestinal region. In vivo studies data indicated that the developed nanocarriers can induce a strong mucosal as well as systemic immune response. Therefore, the experimental evidence suggests that guar-gum nanoparticle findings indicated that the guar gum nanoparticles can be utilized for safe and effective vaccine delivery via oral route.

Published
2015
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5. CD226 as a genetic adjuvant to enhance immune efficacy induced by Ag85A DNA vaccination.

Author

Li Y, Yang F, Zhu J, Sang L, Han X, Wang D, Shan F, Li S, Sun X, and Lu C

Subjects
Acyltransferases genetics, Adjuvants, Immunologic genetics, Animals, Antibodies, Bacterial blood, Antigens, Bacterial genetics, Antigens, Differentiation, T-Lymphocyte genetics, Cytokines metabolism, Cytotoxicity, Immunologic, DNA, Bacterial genetics, Female, HEK293 Cells, Humans, Immunity, Humoral, Lymphocyte Activation, Mice, Mice, Inbred C57BL, Tuberculosis prevention & control, Vaccination, Acyltransferases immunology, Antigens, Bacterial immunology, Antigens, Differentiation, T-Lymphocyte immunology, Killer Cells, Natural immunology, Mycobacterium tuberculosis physiology, T-Lymphocytes, Cytotoxic immunology, Th1 Cells immunology, Tuberculosis immunology, Vaccines, DNA administration & dosage
Abstract

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., (Copyright © 2015. Published by Elsevier B.V.)

Published
2015
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6. Evaluation of protective efficacy conferred by a recombinant Mycobacterium bovis BCG expressing a fusion protein of Ag85A-ESAT-6.

Author

Deng YH, He HY, and Zhang BS

Subjects
Acyltransferases genetics, Animals, Antigens, Bacterial genetics, BCG Vaccine administration & dosage, BCG Vaccine genetics, Bacterial Load, Bacterial Proteins genetics, Body Weight, Female, Histocytochemistry, Immunohistochemistry, Lung immunology, Lung microbiology, Lung pathology, Mice, Mice, Inbred BALB C, Mycobacterium tuberculosis immunology, Mycobacterium tuberculosis isolation & purification, Recombinant Fusion Proteins genetics, Recombinant Fusion Proteins immunology, Tuberculosis immunology, Vaccines, Synthetic administration & dosage, Vaccines, Synthetic genetics, Vaccines, Synthetic immunology, Acyltransferases immunology, Antigens, Bacterial immunology, BCG Vaccine immunology, Bacterial Proteins immunology, Tuberculosis prevention & control
Abstract

Background: We previously constructed a recombinant bacille Calmette-Guérin (rBCG-AE) strain that could express a fused Ag85A-ESAT-6 protein. That study suggested that the rBCG-AE strain was able to induce a higher titer of antibody and elicit a more long-lived and stronger Th1-type cellular immune responses than the parental BCG strain, the rBCG-A strain (i.e., expressing Ag85A), or the rBCG-E strain (i.e., expressing ESAT-6)., Methods: In the current study, we further investigated the strain's protective efficacy against Mycobacterium tuberculosis H37Rv infection in BALB/c mice through evaluating organ bacterial loads, lung histopathology, lung immunohistochemistry, and net weight gain or loss by using conventional BCG, rBCG-A, and rBCG-E as the controls., Results: From the 3rd to 9th weeks after the challenge infection, the bacterial counts were significantly lower in tissues (e.g., spleen and lung tissues) in the mice immunized with rBCG-AE than in the control group, but were higher than the counts in the BCG group. The pathological damage in the lung tissues of the rBCG-AE group gradually improved from the 6th to 9th weeks after being infected with M. tuberculosis H37Rv, but the score of pathological changes in the rBCG-AE group was obviously higher than the score in the BCG group. There was no difference in the percentage of IFN-γ and iNOS positive cells in the lung tissues of the rBCG-AE and BCG groups., Conclusion: The results suggest that rBCG-AE can not promote protective efficacy against M. tuberculosis H37Rv infection, compared to the BCG vaccine., (Copyright © 2012. Published by Elsevier B.V.)

Published
2014
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7. Construction of a DNA vaccine based on the Mycobacterium tuberculosis Ag85A/MPT64 fusion gene and evaluation of its immunogenicity.

Author

Bao H, Yu T, Jin Y, Teng C, Liu X, and Li Y

Subjects
Acyltransferases metabolism, Animals, Antibodies, Bacterial immunology, Antigens, Bacterial metabolism, Bacterial Proteins metabolism, Cloning, Molecular, Enzyme-Linked Immunospot Assay, Female, Mice, Mice, Inbred BALB C, Mycobacterium tuberculosis genetics, Mycobacterium tuberculosis metabolism, Plasmids metabolism, Recombinant Fusion Proteins biosynthesis, Recombinant Fusion Proteins genetics, Recombinant Fusion Proteins pharmacology, Acyltransferases genetics, Antigens, Bacterial genetics, Bacterial Proteins genetics, Vaccines, DNA immunology
Abstract

The aim of this study was to construct a DNA vaccine based on the Ag85A/MPT64 gene of Mycobacterium tuberculosis (MTB) and analyze its immunogenicity by enzyme-linked immunospot (ELISPOT) assay. The fusion gene encoding Ag85A/MPT64 was amplified by PCR from the genome of the MTB H37Rv strain and cloned into a eukaryotic expression vector followed by confirmation using restriction endonuclease digestion and DNA sequencing. The immunogenicity of the recombinant vector was tested in vivo in BALB/c mice. The serum antibody titers against Ag85A/MPT64 were detected by ELISPOT assay. The number of ELISPOT spots for the mice following immunization with Ag85A/MPT64 was significantly greater than for the negative and blank controls. A DNA vaccine based on the gene encoding the Ag85A/MPT64 fusion protein of MTB was successfully constructed and expressed. Our data may serve as a foundation for further research into the prevention and treatment of tuberculosis and carcinomas.

Published
2012
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8. IL-12 DNA Displays Efficient Adjuvant Effects Improving Immunogenicity of Ag85A in DNA Prime/MVA Boost Immunizations

Author

María Paula Morelli, María Paula Del Medico Zajac, Joaquín Miguel Pellegrini, Nicolás Oscar Amiano, Nancy Liliana Tateosian, Gabriela Calamante, María Magdalena Gherardi, and Verónica Edith García

Subjects
0301 basic medicine, Modified vaccinia Ankara, Ag85A, medicine.medical_treatment, lcsh:QR1-502, VACCINE, Inmunogenética, lcsh:Microbiology, IL-12, MVA, Mice, Cellular and Infection Microbiology, vaccine, Vaccines, DNA, Medicine, Tuberculosis Vaccines, biology, Immunogenicity, Brief Research Report, MVA, Interleukin-12, Vaccination, Infectious Diseases, tuberculosis, IL-12, AG85A, BCG Vaccine, purl.org/becyt/ford/3 [https], Tuberculosis vaccines, Vaccine Adjuvants, Adjuvant, DNA vaccine, Microbiology (medical), 030106 microbiology, Immunology, Immunization, Secondary, TUBERCULOSIS, Microbiology, DNA vaccination, Mycobacterium tuberculosis, purl.org/becyt/ford/3.3 [https], 03 medical and health sciences, Immune system, Immunogenetics, Animals, Antigens, Bacterial, business.industry, DNA, biology.organism_classification, DNA VACCINE, Virology, 030104 developmental biology, Coadyuvantes de Vacunas, business, Acyltransferases, Mycobacterium Tuberculosis
Abstract

Mycobacterium tuberculosis (Mtb) infection is one of the leading causes of death worldwide. The Modified Vaccinia Ankara (MVA) vaccine vector expressing the mycobacterial antigen 85A (MVA85A) was demonstrated to be safe, although it did not improve BCG efficacy, denoting the need to search for improved tuberculosis vaccines. In this work, we investigated the effect of IL-12 DNA -as an adjuvant- on an Ag85A DNA prime/MVA85A boost vaccination regimen. We evaluated the immune response profile elicited in mice and the protection conferred against intratracheal Mtb H37Rv challenge. We observed that the immunization scheme including DNA-A85A+DNA-IL-12/MVA85A induced a strong IFN-γ production to Ag85A in vitro, with a significant expansion of IFN-γ+CD4+ and IFN-γ+CD8+ anti-Ag85A lymphocytes. Furthermore, we also detected a significant increase in the proportion of specific CD8+CD107+ T cells against Ag85A. Additionally, inclusion of IL-12 DNA in the DNA-A85A/MVA85A vaccine scheme induced a marked augment in anti-Ag85A IgG levels. Interestingly, after 30 days of infection with Mtb H37Rv, DNA-A85A+DNA-IL-12/MVA85A vaccinated mice displayed a significant reduction in lung bacterial burden. Together, our findings suggest that IL-12 DNA might be useful as a molecular adjuvant in an Ag85A DNA/MVA prime-boost vaccine against Mtb infection. Fil: Morelli, María Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina Fil: del Medico Zajac, Maria Paula. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; Argentina Fil: Pellegrini, Joaquín Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina Fil: Amiano, Nicolás Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina Fil: Tateosian, Nancy Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina Fil: Calamante, Gabriela. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; Argentina Fil: Gherardi, Maria Magdalena. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; Argentina Fil: García, Verónica Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina

Published
2020

9. Down selecting adjuvanted vaccine formulations: a comparative method for harmonized evaluation

Author

E. J. Remarque, Vinod Sommandas, Sumera Younis, Christophe Barnier-Quer, Patrice M. Dubois, Martin Friede, Clemens H. M. Kocken, Nicole vd.Werff, Nicolas Collin, Simon Heuking, and Livia Brunner

Subjects
0301 basic medicine, Enzyme-Linked Immunospot Assay, HBsAg, Ag85A, medicine.medical_treatment, Protozoan Proteins, 0302 clinical medicine, 030212 general & internal medicine, Vaccines, Acyltransferases/immunology, Adjuvants, Immunologic/analysis, Animals, Antigens, Bacterial/immunology, Antigens, Protozoan/immunology, Enzyme-Linked Immunosorbent Assay/methods, Enzyme-Linked Immunospot Assay/methods, Hepatitis B Surface Antigens/immunology, Immunization, Immunoglobulin G/blood, Immunoglobulin G/immunology, Interferon-gamma/immunology, Interferon-gamma/metabolism, Interleukin-5/immunology, Interleukin-5/metabolism, Membrane Proteins/immunology, Mice, Inbred C57BL, Protozoan Proteins/immunology, Reproducibility of Results, Spleen/cytology, Spleen/immunology, Spleen/metabolism, Vaccines/analysis, Vaccines/immunology, AMA1, Adjuvants, Aluminium oxyhydroxide, Hepatitis B, Plasmodium falciparum, QS21, Squalene-in-water SWE, Tuberculosis, ELISPOT, Immunogenicity, 3. Good health, Vaccination, Adjuvant, Research Article, lcsh:Immunologic diseases. Allergy, Immunology, Antigens, Protozoan, Enzyme-Linked Immunosorbent Assay, Interferon-gamma, 03 medical and health sciences, Adjuvants, Immunologic, Antigen, medicine, Apical membrane antigen 1, Antigens, Bacterial, Hepatitis B Surface Antigens, business.industry, Membrane Proteins, 030104 developmental biology, Immunoglobulin G, Interleukin-5, business, lcsh:RC581-607, Acyltransferases, Spleen
Abstract

Background: The need for rapid and accurate comparison of panels of adjuvanted vaccine formulations and subsequent rational down selection, presents several challenges for modern vaccine development. Here we describe a method which may enable vaccine and adjuvant developers to compare antigen/adjuvant combinations in a harmonized fashion. Three reference antigens: Plasmodium falciparum apical membrane antigen 1 (AMA1), hepatitis B virus surface antigen (HBsAg), and Mycobacterium tuberculosis antigen 85A (Ag85A), were selected as model antigens and were each formulated with three adjuvants: aluminium oxyhydroxide, squalene-in-water emulsion, and a liposome formulation mixed with the purified saponin fraction QS21.Results: The nine antigen/adjuvant formulations were assessed for stability and immunogenicity in mice in order to provide benchmarks against which other formulations could be compared, in order to assist subsequent down selection of adjuvanted vaccines. Furthermore, mouse cellular immune responses were analyzed by measuring IFN-γ and IL-5 production in splenocytes by ELISPOT, and humoral responses were determined by antigen-specific ELISA, where levels of total IgG, IgG1, IgG2b and IgG2c in serum samples were determined.Conclusions: The reference antigens and adjuvants described in this study, which span a spectrum of immune responses, are of potential use as tools to act as points of reference in vaccine development studies. The harmonized methodology described herein may be used as a tool for adjuvant/antigen comparison studies.

Published
2018

10. Evaluation of Immunogenicity and Protective Efficacy Elicited by Mycobacterium bovis BCG Overexpressing Ag85A Protein against Mycobacterium tuberculosis Aerosol Infection

Author

Xiang Chen, Chuang Meng, Zheng Zhong Xu, Xin An Jiao, Zhi Ming Pan, Xiaobo Wang, Xiaoming Zhang, Yue Lan Yin, Ting Hu, and Yan Rao

Subjects
0301 basic medicine, Ag85A, lcsh:QR1-502, recombinant BCG, immunogenicity, lcsh:Microbiology, Mice, Medicine, Lung, Original Research, Mycobacterium bovis, Vaccines, Synthetic, biology, Immunogenicity, Vaccination, Antibody titer, Antibodies, Bacterial, Recombinant Proteins, Infectious Diseases, BCG Vaccine, Female, Microbiology (medical), Tuberculosis, Immunology, complex mixtures, Microbiology, Mycobacterium tuberculosis, 03 medical and health sciences, Interferon-gamma, Antigen, Animals, protective efficacy, Antigens, Bacterial, business.industry, Dendritic Cells, Th1 Cells, biology.organism_classification, medicine.disease, Virology, Bacterial Load, Mice, Inbred C57BL, 030104 developmental biology, Lymph Nodes, business, BCG vaccine, Acyltransferases, Spleen
Abstract

Mycobacterium bovis bacillus Calmette-Guérin (BCG) is currently the only vaccine available against tuberculosis (TB), however, it has various levels of efficacy for preventing pulmonary TB. In this study, a recombinant BCG (rBCG::Ag85A) strain overexpressing the immunodominant Ag85A antigen was constructed, and its immunogenicity and protective efficacy were evaluated. The results showed that the Ag85A protein was successfully overexpressed in rBCG::Ag85A, the Ag85A peptide–MHC complexes on draining lymph node dendritic cells of C57BL/6 mice infected with rBCG were detectable 4 h post-infection. The C57BL/6 mice infected with this strain had stronger antigen-specific interferon-gamma (IFN-γ) responses and higher antibody titers than those immunized with BCG, and the protective experiments showed that the rBCG::Ag85A can provide higher but not significantly protective efficacy against Mycobacterium tuberculosis (M. tuberculosis) H37Rv infection compared with BCG vaccine. Therefore, our results demonstrated the potential of rBCG::Ag85A as a vaccine candidate against TB.

Published
2015

11. Mucosal prime-boost vaccination for tuberculosis based on TLR triggering OprI lipoprotein from Pseudomonas aeruginosa fused to mycolyl-transferase Ag85A

Author

Samuel Otieno, Hilde Revets, Patrick De Baetselier, Kris Huygen, Tatiana Gartner, Martijn Baeten, and Cellular and Molecular Immunology

Subjects
Tuberculosis, Ag85A, medicine.medical_treatment, Lipoproteins, Recombinant Fusion Proteins, Immunology, Immunization, Secondary, Biology, Microbiology, Mice, Immune system, Antigen, Bacterial Proteins, Interferon, OprI, medicine, Vaccines, DNA, Immunology and Allergy, Animals, Administration, Intranasal, Antigens, Bacterial, Toll-Like Receptors, medicine.disease, Interleukin-10, TLR2, Pseudomonas aeruginosa, BCG Vaccine, Interleukin-4, Tuberculosis vaccines, Adjuvant, BCG vaccine, Acyltransferases, medicine.drug
Abstract

Toll-like receptor (TLR) triggering is an important step in the induction of T helper (Th) type 1 T cells which are key players in protection against the intracellular pathogen Mycobacterium ( M. ) tuberculosis . Here we report on the construction of a fusion protein consisting of a tuberculosis vaccine candidate mycolyl-transferase antigen 85A (Ag85A, Rv3804c) coupled to the outer membrane lipoprotein I (OprI) from Pseudomonas ( P. ) aeruginosa , a documented TLR2/TLR4 trigger. Subcutaneous boosting with this fusion protein in the absence of adjuvant increased significantly the Ag85A-specific humoral but not cellular immune responses of Ag85A-DNA vaccinated mice. Intranasal priming of C57BL/6 mice with live, attenuated Mycobacterium bovis bacille Calmette-Guerin (BCG) vaccine, followed by intranasal boosting with OprI-Ag85A increased systemic and local antigen-specific interferon (IFN)-γ and interleukin (IL)-2 responses in spleen, draining cervical and mediastinal lymph nodes and particularly in lung tissue, as compared to responses in mice only vaccinated with BCG vaccine. Despite enhanced immune responses, boosting with OprI-Ag85A did not increase protective efficacy against M. tuberculosis of either plasmid DNA or BCG vaccine in this experimental setting.

Published
2007

12. Evaluation of protective efficacy conferred by a recombinant Mycobacterium bovis BCG expressing a fusion protein of Ag85A-ESAT-6

Author

Hong-Yun He, Ben-Si Zhang, and Yi-Hao Deng

Subjects
Microbiology (medical), Tuberculosis, Ag85A, Recombinant Fusion Proteins, Spleen, complex mixtures, Mice, Immune system, Bacterial Proteins, Immunology and Microbiology(all), ESAT-6, medicine, Animals, Immunology and Allergy, Lung, Antigens, Bacterial, Mice, Inbred BALB C, Vaccines, Synthetic, Mycobacterium bovis, General Immunology and Microbiology, biology, Histocytochemistry, Body Weight, Protective efficacy, Mycobacterium tuberculosis, General Medicine, biology.organism_classification, medicine.disease, Immunohistochemistry, Bacterial Load, Recombinant Mycobacterium bovis bacillus Calmette-Guérin (rBCG), Titer, Infectious Diseases, medicine.anatomical_structure, Immunology, BCG Vaccine, biology.protein, Female, Antibody, BCG vaccine, Acyltransferases
Abstract

Background We previously constructed a recombinant bacille Calmette-Guerin (rBCG-AE) strain that could express a fused Ag85A-ESAT-6 protein. That study suggested that the rBCG-AE strain was able to induce a higher titer of antibody and elicit a more long-lived and stronger Th1-type cellular immune responses than the parental BCG strain, the rBCG-A strain (i.e., expressing Ag85A), or the rBCG-E strain (i.e., expressing ESAT-6). Methods In the current study, we further investigated the strain's protective efficacy against Mycobacterium tuberculosis H37Rv infection in BALB/c mice through evaluating organ bacterial loads, lung histopathology, lung immunohistochemistry, and net weight gain or loss by using conventional BCG, rBCG-A, and rBCG-E as the controls. Results From the 3rd to 9th weeks after the challenge infection, the bacterial counts were significantly lower in tissues (e.g., spleen and lung tissues) in the mice immunized with rBCG-AE than in the control group, but were higher than the counts in the BCG group. The pathological damage in the lung tissues of the rBCG-AE group gradually improved from the 6th to 9th weeks after being infected with M. tuberculosis H37Rv, but the score of pathological changes in the rBCG-AE group was obviously higher than the score in the BCG group. There was no difference in the percentage of IFN-γ and iNOS positive cells in the lung tissues of the rBCG-AE and BCG groups. Conclusion The results suggest that rBCG-AE can not promote protective efficacy against M. tuberculosis H37Rv infection, compared to the BCG vaccine.

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