MTBVAC-Based TB-HIV Vaccine Is Safe, Elicits HIV-T Cell Responses, and Protects against Mycobacterium tuberculosis in Mice (original) (raw)
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Vaccine, 2009
M. bovis BCG is an attractive vaccine vector against breast milk HIV transmission because it elicits Th1-type responses in newborns. However, BCG causes disease in HIV-infected infants. Genetically attenuated M. tuberculosis (Mtb) mutants represent a safer alternative for immunocompromised populations. In the current study, we compared the immunogenicity in mice of three different recombinant attenuated Mtb strains expressing an HIV envelope (Env) antigen construct. Two of these strains (ΔlysA ΔpanCD Mtb and ΔRD1 ΔpanCD Mtb) failed to induce significant levels of HIV Env-specific CD8 + T cell responses. In striking contrast, an HIV-1-Env-expressing attenuated ΔlysA Mtb containing a deletion in secA2, which encodes a virulence-related secretion system involved in evading adaptive immunity, generated consistently measurable Env-specific CD8 + T cell responses that were significantly greater than those observed after immunization with BCG expressing HIV Env. Similarly, another strain of ΔlysA ΔsecA2 Mtb expressing SIV Gag induced Gag-and Mtb-specific CD8 + T cells producing perforin or IFNγ, and Gag-specific CD4 + T cells producing IFNγ within 3 weeks after immunization in adult mice; in addition, IFNγ producing Gagspecific CD8 + T cells and Mtb-specific CD4 + T cells were observed in neonatal mice within 1 week of immunization. We conclude that ΔlysA ΔsecA2 Mtb is a promising vaccine platform to construct a safe combination HIV-TB vaccine for use in neonates.
Human Vaccines & Immunotherapeutics
One of the critical issues that should be addressed in the development of a BCG-based HIV vaccine is genetic plasmid stability. Therefore, to address this issue we have considered using integrative vectors and the auxotrophic mutant of BCG complemented with a plasmid carrying a wild-type complementing gene. In this study, we have constructed an integrative E. coli-mycobacterial shuttle plasmid, p2auxo. HIVA int , expressing the HIV-1 clade A immunogen HIVA. This shuttle vector uses an antibiotic resistancefree mechanism for plasmid selection and maintenance. It was first transformed into a glycine auxotrophic E. coli strain and subsequently transformed into a lysine auxotrophic Mycobacterium bovis BCG strain to generate the vaccine BCG.HIVA 2auxo.int. Presence of the HIVA gene sequence and protein expression was confirmed. We demonstrated that the in vitro stability of the integrative plasmid p2auxo.HIVA int was increased 4-fold, as compared with the BCG strain harboring the episomal plasmid, and was genetically and phenotypically characterized. The BCG.HIVA 2auxo.int vaccine in combination with modified vaccinia virus Ankara (MVA).HIVA was found to be safe and induced HIV-1 and Mycobacterium tuberculosis-specific interferon-g-producing T-cell responses in adult BALB/c mice. We have engineered a more stable and immunogenic BCG-vectored vaccine using the prototype immunogen HIVA. Thus, the use of integrative expression vectors and the antibiotic-free plasmid selection system based on "double" auxotrophic complementation are likely to improve the mycobacterial vaccine stability in vivo and immunogenicity to develop not only recombinant BCG-based vaccines expressing second generation of HIV-1 immunogens but also other major pediatric pathogens to prime protective responses shortly following birth.
Journal of Virology, 2010
Mycobacterium bovis bacillus Calmette-Guérin (BCG), which elicits a degree of protective immunity against tuberculosis, is the most widely used vaccine in the world. Due to its persistence and immunogenicity, BCG has been proposed as a vector for vaccines against other infections, including HIV-1. BCG has a very good safety record, although it can cause disseminated disease in immunocompromised individuals. Here, we constructed a recombinant BCG vector expressing HIV-1 clade A-derived immunogen HIVA using the recently described safer and more immunogenic BCG strain AERAS-401 as the parental mycobacterium. Using routine ex vivo T-cell assays, BCG.HIVA 401 as a stand-alone vaccine induced undetectable and weak CD8 T-cell responses in BALB/c mice and rhesus macaques, respectively. However, when BCG.HIVA 401 was used as a priming component in heterologous vaccination regimens together with recombinant modified vaccinia virus Ankaravectored MVA.HIVA and ovine atadenovirus-vectored OAdV.HIVA vaccines, robust HIV-1-specific T-cell responses were elicited. These high-frequency T-cell responses were broadly directed and capable of proliferation in response to recall antigen. Furthermore, multiple antigen-specific T-cell clonotypes were efficiently recruited into the memory pool. These desirable features are thought to be associated with good control of HIV-1 infection. In addition, strong and persistent T-cell responses specific for the BCG-derived purified protein derivative (PPD) antigen were induced. This work is the first demonstration of immunogenicity for two novel vaccine vectors and the corresponding candidate HIV-1 vaccines BCG.HIVA 401 and OAdV.HIVA in nonhuman primates. These results strongly support their further exploration.
PLOS ONE, 2015
Bacille Calmette-Guérin (BCG) vaccination of new born babies can protect children against tuberculosis (TB), but fails to protect adults consistently against pulmonary TB underlying the urgent need to develop novel TB vaccines. Majority of first generation TB vaccine candidates have relied on a very limited number of antigens typically belonging to the active phase of infection. We have designed a multi-antigenic and multiphasic vaccine, based on the Modified Vaccinia Ankara virus (MVA). Up to fourteen antigens representative of the three phases of TB infection (active, latent and resuscitation) were inserted into MVA. Using three different strains of mouse (BALB/c, C57BL/6 and C3H/HeN), we show that a single vaccination results in induction of both CD4 and CD8 T cells, displaying capacity to produce multiple cytokines together with cytolytic activity targeting a large array of epitopes. As expected, dominance of responses was linked to the mouse haplotype although for a given haplotype, responses specific of at least one antigen per phase could always be detected. Vaccination of non-human primates with the 14 antigens MVA-TB candidate resulted in broad and potent cellular-based immunogenicity. The remarkable plasticity of MVA opens the road to development of a novel class of highly complex recombinant TB vaccines to be evaluated in both prophylactic and therapeutic settings.
Dual neonate vaccine platform against HIV-1 and M. tuberculosis
PLoS ONE, 2011
Acquired immunodeficiency syndrome and tuberculosis (TB) are two of the world's most devastating diseases. The first vaccine the majority of infants born in Africa receive is Mycobacterium bovis bacillus Calmette-Guérin (BCG) as a prevention against TB. BCG protects against disseminated disease in the first 10 years of life, but provides a variable protection against pulmonary TB and enhancing boost delivered by recombinant modified vaccinia virus Ankara (rMVA) expressing antigen 85A (Ag85A) of M. tuberculosis is currently in phase IIb evaluation in African neonates. If the newborn's mother is positive for human immunodeficiency virus type 1 (HIV-1), the baby is at high risk of acquiring HIV-1 through breastfeeding. We suggested that a vaccination consisting of recombinant BCG expressing HIV-1 immunogen administered at birth followed by a boost with rMVA sharing the same immunogen could serve as a strategy for prevention of mother-to-child transmission of HIV-1 and rMVA expressing an African HIV-1-derived immunogen HIVA is currently in phase I trials in African neonates. Here, we aim to develop a dual neonate vaccine platform against HIV-1 and TB consisting of BCG.HIVA administered at birth followed by a boost with MVA.HIVA.85A. Thus, mMVA.HIVA.85A and sMVA.HIVA.85A vaccines were constructed, in which the transgene transcription is driven by either modified H5 or short synthetic promoters, respectively, and tested for immunogenicity alone and in combination with BCG.HIVA 222. mMVA.HIVA.85A was produced markerless and thus suitable for clinical manufacture. While sMVA.HIVA.85A expressed higher levels of the immunogens, it was less immunogenic than mMVA.HIVA.85A in BALB/c mice. A BCG.HIVA 222-mMVA.HIVA.85A prime-boost regimen induced robust T cell responses to both HIV-1 and M. tuberculosis. Therefore, proof-of-principle for a dual anti-HIV-1/M. tuberculosis infant vaccine platform is established. Induction of immune responses against these pathogens soon after birth is highly desirable and may provide a basis for lifetime protection maintained by boosts later in life.
PLoS ONE, 2012
In the past, we proposed to develop a heterologous recombinant BCG prime-recombinant modified vaccinia virus Ankara (MVA) boost dual pediatric vaccine platform against transmission of breast milk HIV-1 and Mycobacterium tuberculosis (Mtb). In this study, we assembled an E. coli-mycobacterial shuttle plasmid pJH222.HIVA CAT expressing HIV-1 clade A immunogen HIVA. This shuttle vector employs an antibiotic resistance-free mechanism based on Operator-Repressor Titration (ORT) system for plasmid selection and maintenance in E. coli and lysine complementation in mycobacteria. This shuttle plasmid was electroporated into parental lysine auxotroph (safer) strain of BCG to generate vaccine BCG.HIVA CAT. All procedures complied with Good Laboratory Practices (GLPs). We demonstrated that the episomal plasmid pJH222.HIVA CAT was stable in vivo over a 20-week period, and genetically and phenotypically characterized the BCG.HIVA CAT vaccine strain. The BCG.HIVA CAT vaccine in combination with MVA.HIVA induced HIV-1-and Mtb-specific interferon c-producing T-cell responses in newborn and adult BALB/c mice. On the other hand, when adult mice were primed with BCG.HIVA CAT and boosted with MVA.HIVA.85A, HIV-1-specific CD8 + T-cells producing IFN-c, TNF-a, IL-2 and CD107a were induced. To assess the biosafety profile of BCG.HIVA CAT-MVA.HIVA regimen, body mass loss of newborn mice was monitored regularly throughout the vaccination experiment and no difference was observed between the vaccinated and naïve groups of animals. Thus, we demonstrated T-cell immunogenicity of a novel, safer, GLP-compatible BCG-vectored vaccine using prototype immunogen HIVA. Second generation immunogens derived from HIV-1 as well as other major pediatric pathogens can be constructed in a similar fashion to prime protective responses soon after birth.
American Journal of Respiratory and Critical Care Medicine, 2012
Rationale: Novel tuberculosis (TB) vaccines should be safe and effective in populations infected with Mycobacterium tuberculosis (M.tb) and/or HIV for effective TB control. Objective: To determine the safety and immunogenicity of MVA85A, a novel TB vaccine, among M.tband/or HIV-infected persons in a setting where TB and HIV are endemic. Methods: An open-label, phase IIa trial was conducted in 48 adults with M.tb and/or HIV infection. Safety and immunogenicity were analyzed up to 52 weeks after intradermal vaccination with 5 3 10 7 plaque-forming units of MVA85A. Specific T-cell responses were characterized by IFN-g enzyme-linked immunospot and whole blood intracellular cytokine staining assays. Measurements and Main Results: MVA85A was well tolerated and no vaccine-related serious adverse events were recorded. MVA85A induced robust and durable response of mostly polyfunctional CD4 1 T cells, coexpressing IFN-g, tumor necrosis factor-a, and IL-2. Magnitudes of pre-and postvaccination T-cell responses were lower in HIV-infected, compared with HIV-uninfected, vaccinees. No significant effect of antiretroviral therapy on immunogenicity of MVA85A was observed. Conclusions: MVA85A was safe and immunogenic in persons with HIV and/or M.tb infection. These results support further evaluation of safety and efficacy of this vaccine for prevention of TB in these target populations.
Vaccine, 2013
The development of a new tuberculosis vaccine is an urgent need due to the failure of the current vaccine, BCG, to protect against the respiratory form of the disease. MTBVAC is an attenuated Mycobacterium tuberculosis vaccine candidate genetically engineered to fulfil the Geneva consensus requirements to enter human clinical trials. We selected a M. tuberculosis clinical isolate to generate two independent deletions without antibioticresistance markers in the genes phoP, coding for a transcription factor key for the regulation of M. tuberculosis virulence, and fadD26, essential for the synthesis of the complex lipids phthiocerol dimycocerosates (DIM), one of the major mycobacterial virulence factors. The resultant strain MTBVAC exhibits safety and biodistribution profiles similar to BCG and confers superior protection in preclinical studies. These features have enabled MTBVAC to be the first live attenuated M. tuberculosis vaccine to enter clinical evaluation.
American Journal of Respiratory and Critical Care Medicine, 2012
Rationale: Novel tuberculosis (TB) vaccines should be safe and effective in populations infected with Mycobacterium tuberculosis (M.tb) and/or HIV for effective TB control. Objective: To determine the safety and immunogenicity of MVA85A, a novel TB vaccine, among M.tband/or HIV-infected persons in a setting where TB and HIV are endemic. Methods: An open-label, phase IIa trial was conducted in 48 adults with M.tb and/or HIV infection. Safety and immunogenicity were analyzed up to 52 weeks after intradermal vaccination with 5 3 10 7 plaque-forming units of MVA85A. Specific T-cell responses were characterized by IFN-g enzyme-linked immunospot and whole blood intracellular cytokine staining assays. Measurements and Main Results: MVA85A was well tolerated and no vaccine-related serious adverse events were recorded. MVA85A induced robust and durable response of mostly polyfunctional CD4 1 T cells, coexpressing IFN-g, tumor necrosis factor-a, and IL-2. Magnitudes of pre-and postvaccination T-cell responses were lower in HIV-infected, compared with HIV-uninfected, vaccinees. No significant effect of antiretroviral therapy on immunogenicity of MVA85A was observed. Conclusions: MVA85A was safe and immunogenic in persons with HIV and/or M.tb infection. These results support further evaluation of safety and efficacy of this vaccine for prevention of TB in these target populations. New, more effective tuberculosis vaccines are urgently required for people infected with Mycobacterium tuberculosis (M.tb) and/or HIV. We conducted an open-label, phase IIa trial to determine the safety and immunogenicity of MVA85A vaccination in 48 adults with M.tb and/or HIV infection, off and on antiretroviral therapy. What This Study Adds to the Field MVA85A vaccination induced mild local reactions in all participants with M.tb and/or HIV infection, but was well tolerated. The vaccine induced long-lived, predominantly polyfunctional CD4 T-cell responses. Infection with HIV resulted in lower vaccination-induced immune responses than observed in HIV-uninfected subjects. Our findings support further evaluation and efficacy testing of MVA85A as a booster vaccine for BCG in these important target populations.
Vaccines, 2019
Despite the availability of anti-retroviral therapy, HIV-1 infection remains a massive burden on healthcare systems. Bacillus Calmette-Guérin (BCG), the only licensed vaccine against tuberculosis, confers protection against meningitis and miliary tuberculosis in infants. Recombinant BCG has been used as a vaccine vehicle to express both HIV-1 and Simian Immunodeficiemcy Virus (SIV) immunogens. In this study, we constructed an integrative E. coli-mycobacterial shuttle plasmid, p2auxo.HTI.int, expressing the HIVACAT T-cell immunogen (HTI). The plasmid was transformed into a lysine auxotrophic Mycobacterium bovis BCG strain (BCGΔLys) to generate the vaccine BCG.HTI2auxo.int. The DNA sequence coding for the HTI immunogen and HTI protein expression were confirmed, and working vaccine stocks were genetically and phenotypically characterized. We demonstrated that the vaccine was stable in vitro for 35 bacterial generations, and that when delivered in combination with chimpanzee adenovirus ...