Neonatal BCG Immunization Followed by DNAhsp65 Boosters: Highly Immunogenic but not Protective Against Tuberculosis – a Paradoxical Effect of the Vector?

A new tuberculosis vaccine is urgently needed. Prime‐boost strategies are considered very promising and the inclusion of BCG is highly desirable. In this investigation, we tested the protective efficacy of BCG delivered in the neonatal period followed by boosters in the adult phase with a DNA vaccine containing the hsp65 gene from Mycobacterium leprae (pVAXhsp65). Immune responses were characterized by serum anti‐hsp65 antibody levels and IFN‐γ and IL‐5 production by the spleen. Amounts of these cytokines were also determined in lung homogenates. Protective efficacy was established by the number of colony‐forming units (CFU) and histopathological analysis of the lungs after challenge with Mycobacterium tuberculosis. Immunization with BCG alone triggered a significant reduction of CFU in the lungs and also clearly preserved the pulmonary parenchyma. BCG priming also increased the immunogenicity of pVAXhsp65. However, boosters with pVAXhsp65 or the empty vector abolished the protective efficacy of BCG. Also, higher IL‐5 levels were produced by spleen and lungs after DNA boosters. These results demonstrated that neonatal BCG immunization followed by DNAhsp65 boosters is highly immunogenic but is not protective against tuberculosis.

[1]  C. Power,et al.  Mycobacterial Dose Defines the Th1/Th2 Nature of the Immune Response Independently of Whether Immunization Is Administered by the Intravenous, Subcutaneous, or Intradermal Route , 1998, Infection and Immunity.

[2]  C S Berkey,et al.  Efficacy of BCG vaccine in the prevention of tuberculosis. Meta-analysis of the published literature. , 1994, JAMA.

[3]  G. Rook,et al.  Immunological and endocrinological characteristics of tuberculosis that provide opportunities for immunotherapeutic intervention. , 1998, Novartis Foundation symposium.

[4]  P. Andersen,et al.  TB vaccines: progress and problems. , 2001, Trends in immunology.

[5]  H. C. Sweany.  The pathogenesis of tuberculosis. , 1948, Cincinnati journal of medicine.

[6]  Mahavir Singh,et al.  Exposure to Mycobacteria Primes the Immune System for Evolutionarily Diverse Heat Shock Proteins , 2005, Infection and Immunity.

[7]  D. McMurray,et al.  A coordinated strategy for evaluating new vaccines for human and animal tuberculosis. , 2001, Tuberculosis.

[8]  A. Ramsay,et al.  The prime-boost strategy: exciting prospects for improved vaccination. , 2000, Immunology today.

[9]  K. Moelling,et al.  Therapy of tuberculosis in mice by DNA vaccination , 1999, Nature.

[10]  A. Krieg.  A role for Toll in autoimmunity , 2002, Nature Immunology.

[11]  I. Sutherland,et al.  A re-examination of the variations in the efficacy of BCG vaccination against tuberculosis in clinical trials. , 1994, Tubercle and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease.

[12]  Olivier Denis,et al.  Improved Immunogenicity and Protective Efficacy of a Tuberculosis DNA Vaccine Encoding Ag85 by Protein Boosting , 2001, Infection and Immunity.

[13]  M. Colston,et al.  Vaccination against tuberculosis by DNA injection , 1996, Nature Medicine.

[14]  P. Lambert,et al.  Neonatal and early life immune responses to various forms of vaccine antigens qualitatively differ from adult responses: predominance of a Th2‐biased pattern which persists after adult boosting , 1996, European journal of immunology.

[15]  John Chan,et al.  Tuberculosis: Latency and Reactivation , 2001, Infection and Immunity.

[16]  H. McShane,et al.  Enhanced Immunogenicity of CD4+ T-Cell Responses and Protective Efficacy of a DNA-Modified Vaccinia Virus Ankara Prime-Boost Vaccination Regimen for Murine Tuberculosis , 2001, Infection and Immunity.

[17]  G. Boccaccio,et al.  Non-coding plasmid DNA induces IFN-gamma in vivo and suppresses autoimmune encephalomyelitis. , 1999, International immunology.

[18]  B. Bloom,et al.  Drying a tuberculosis vaccine without freezing , 2007, Proceedings of the National Academy of Sciences.

[19]  C. L. Silva,et al.  Identification and Characterization of Protective T Cells in hsp65 DNA-Vaccinated and Mycobacterium tuberculosis-Infected Mice , 1998, Infection and Immunity.

[20]  B. Prakken,et al.  Heat-shock proteins induce T-cell regulation of chronic inflammation , 2005, Nature Reviews Immunology.

[21]  L. Steinman,et al.  Non-coding plasmid DNA induces IFN-γ in vivo and suppresses autoimmune encephalomyelitis , 1999 .

[22]  C. L. Silva,et al.  DNA vaccine containing the mycobacterial hsp65 gene prevented insulitis in MLD-STZ diabetes , 2009, Journal of immune based therapies and vaccines.

[23]  E. Benarroch.  Heat shock proteins , 2011, Neurology.

[24]  H. McShane,et al.  Prime-boost immunisation strategies for tuberculosis. , 2005, Microbes and infection.

[25]  P. Payette,et al.  Oligodeoxynucleotides lacking CpG dinucleotides mediate Toll‐like receptor 9 dependent T helper type 2 biased immune stimulation , 2004, Immunology.

[26]  R. L. Zollner,et al.  Immune modulation induced by tuberculosis DNA vaccine protects non‐obese diabetic mice from diabetes progression , 2007, Clinical and experimental immunology.

[27]  A. Sartori,et al.  Immunization with pVAXhsp65 Decreases Inflammation and Modulates Immune Response in Experimental Encephalomyelitis , 2008, Neuroimmunomodulation.

[28]  Asaf Rotem,et al.  Vaccination with Empty Plasmid DNA or CpG Oligonucleotide Inhibits Diabetes in Nonobese Diabetic Mice: Modulation of Spontaneous 60-kDa Heat Shock Protein Autoimmunity1 , 2000, The Journal of Immunology.

[29]  P. Andersen,et al.  The success and failure of BCG — implications for a novel tuberculosis vaccine , 2005, Nature Reviews Microbiology.

[30]  R. Al-Attiyah,et al.  Mycobacterial antigen‐induced T helper type 1 (Th1) and Th2 reactivity of peripheral blood mononuclear cells from diabetic and non‐diabetic tuberculosis patients and Mycobacterium bovis bacilli Calmette–Guérin (BCG)‐vaccinated healthy subjects , 2009, Clinical and experimental immunology.

[31]  P. E. M. Fine,et al.  Variation in protection by BCG: implications of and for heterologous immunity , 1995, The Lancet.

[32]  M. Newport,et al.  Influence of Mycobacterium bovis Bacillus Calmette-Guérin on Antibody and Cytokine Responses to Human Neonatal Vaccination1 , 2002, The Journal of Immunology.

[33]  J. Sadoff,et al.  Advances in tuberculosis vaccine strategies , 2006, Nature Reviews Microbiology.

[34]  G. Buchan,et al.  Vaccine protocols to optimise the protective efficacy of BCG. , 1999, Tubercle and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease.

[35]  S. Cole,et al.  An Increase in Antimycobacterial Th1-Cell Responses by Prime-Boost Protocols of Immunization Does Not Enhance Protection against Tuberculosis , 2006, Infection and Immunity.

[36]  G. Rook,et al.  Mycobacteria and other environmental organisms as immunomodulators for immunoregulatory disorders , 2004, Springer Seminars in Immunopathology.

[37]  M. Nahori,et al.  Development of Mixed Th1/Th2 Type Immune Response and Protection Against Mycobacterium tuberculosis After Rectal or Subcutaneous Immunization of Newborn and Adult Mice with Mycobacterium bovis BCG , 2002, Scandinavian journal of immunology.

[38]  E. Pamer,et al.  Rapid Development of T Cell Memory1 , 2004, The Journal of Immunology.

[39]  G. Schoolnik,et al.  Comparative genomics of BCG vaccines by whole-genome DNA microarray. , 1999, Science.

[40]  H. Vordermeier,et al.  The Order of Prime-Boost Vaccination of Neonatal Calves with Mycobacterium bovis BCG and a DNA Vaccine Encoding Mycobacterial Proteins Hsp65, Hsp70, and Apa Is Not Critical for Enhancing Protection against Bovine Tuberculosis , 2005, Infection and Immunity.