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1.
BMC Bioinformatics ; 20(Suppl 6): 504, 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31822272

RESUMO

BACKGROUND: Tuberculosis (TB) represents a worldwide cause of mortality (it infects one third of the world's population) affecting mostly developing countries, including India, and recently also developed ones due to the increased mobility of the world population and the evolution of different new bacterial strains capable to provoke multi-drug resistance phenomena. Currently, antitubercular drugs are unable to eradicate subpopulations of Mycobacterium tuberculosis (MTB) bacilli and therapeutic vaccinations have been postulated to overcome some of the critical issues related to the increase of drug-resistant forms and the difficult clinical and public health management of tuberculosis patients. The Horizon 2020 EC funded project "In Silico Trial for Tuberculosis Vaccine Development" (STriTuVaD) to support the identification of new therapeutic interventions against tuberculosis through novel in silico modelling of human immune responses to disease and vaccines, thereby drastically reduce the cost of clinical trials in this critical sector of public healthcare. RESULTS: We present the application of the Universal Immune System Simulator (UISS) computational modeling infrastructure as a disease model for TB. The model is capable to simulate the main features and dynamics of the immune system activities i.e., the artificial immunity induced by RUTI® vaccine, a polyantigenic liposomal therapeutic vaccine made of fragments of Mycobacterium tuberculosis cells (FCMtb). Based on the available data coming from phase II Clinical Trial in subjects with latent tuberculosis infection treated with RUTI® and isoniazid, we generated simulation scenarios through validated data in order to tune UISS accordingly to STriTuVaD objectives. The first case simulates the establishment of MTB latent chronic infection with some typical granuloma formation; the second scenario deals with a reactivation phase during latent chronic infection; the third represents the latent chronic disease infection scenario during RUTI® vaccine administration. CONCLUSIONS: The application of this computational modeling strategy helpfully contributes to simulate those mechanisms involved in the early stages and in the progression of tuberculosis infection and to predict how specific therapeutical strategies will act in this scenario. In view of these results, UISS owns the capacity to open the door for a prompt integration of in silico methods within the pipeline of clinical trials, supporting and guiding the testing of treatments in patients affected by tuberculosis.


Assuntos
Simulação por Computador , Vacinas contra a Tuberculose/imunologia , Tuberculose/imunologia , Biologia Computacional , Humanos , Mycobacterium tuberculosis/imunologia , Software
2.
N Engl J Med ; 381(25): 2429-2439, 2019 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-31661198

RESUMO

BACKGROUND: Results of an earlier analysis of a trial of the M72/AS01E candidate vaccine against Mycobacterium tuberculosis showed that in infected adults, the vaccine provided 54.0% protection against active pulmonary tuberculosis disease, without evident safety concerns. We now report the results of the 3-year final analysis of efficacy, safety, and immunogenicity. METHODS: From August 2014 through November 2015, we enrolled adults 18 to 50 years of age with M. tuberculosis infection (defined by positive results on interferon-γ release assay) without evidence of active tuberculosis disease at centers in Kenya, South Africa, and Zambia. Participants were randomly assigned in a 1:1 ratio to receive two doses of either M72/AS01E or placebo, administered 1 month apart. The primary objective was to evaluate the efficacy of M72/AS01E to prevent active pulmonary tuberculosis disease according to the first case definition (bacteriologically confirmed pulmonary tuberculosis not associated with human immunodeficiency virus infection). Participants were followed for 3 years after the second dose. Participants with clinical suspicion of tuberculosis provided sputum samples for polymerase-chain-reaction assay, mycobacterial culture, or both. Humoral and cell-mediated immune responses were evaluated until month 36 in a subgroup of 300 participants. Safety was assessed in all participants who received at least one dose of M72/AS01E or placebo. RESULTS: A total of 3575 participants underwent randomization, of whom 3573 received at least one dose of M72/AS01E or placebo, and 3330 received both planned doses. Among the 3289 participants in the according-to-protocol efficacy cohort, 13 of the 1626 participants in the M72/AS01E group, as compared with 26 of the 1663 participants in the placebo group, had cases of tuberculosis that met the first case definition (incidence, 0.3 vs. 0.6 cases per 100 person-years). The vaccine efficacy at month 36 was 49.7% (90% confidence interval [CI], 12.1 to 71.2; 95% CI, 2.1 to 74.2). Among participants in the M72/AS01E group, the concentrations of M72-specific antibodies and the frequencies of M72-specific CD4+ T cells increased after the first dose and were sustained throughout the follow-up period. Serious adverse events, potential immune-mediated diseases, and deaths occurred with similar frequencies in the two groups. CONCLUSIONS: Among adults infected with M. tuberculosis, vaccination with M72/AS01E elicited an immune response and provided protection against progression to pulmonary tuberculosis disease for at least 3 years. (Funded by GlaxoSmithKline Biologicals and Aeras; ClinicalTrials.gov number, NCT01755598.).


Assuntos
Imunogenicidade da Vacina , Tuberculose Latente/terapia , Mycobacterium tuberculosis/imunologia , Vacinas contra a Tuberculose/imunologia , Tuberculose Pulmonar/prevenção & controle , Adolescente , Adulto , África , Progressão da Doença , Método Duplo-Cego , Feminino , Seguimentos , Soronegatividade para HIV , Humanos , Tuberculose Latente/imunologia , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Adulto Jovem
3.
Infect Immun ; 88(1)2019 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-31591165

RESUMO

Despite the great increase in the understanding of the biology and pathogenesis of Mycobacterium tuberculosis achieved by the scientific community in recent decades, tuberculosis (TB) still represents one of the major threats to global human health. The only available vaccine (Mycobacterium bovis BCG) protects children from disseminated forms of TB but does not effectively protect adults from the respiratory form of the disease, making the development of new and more-efficacious vaccines against the pulmonary forms of TB a major goal for the improvement of global health. Among the different strategies being developed to reach this goal is the construction of attenuated strains more efficacious and safer than BCG. We recently showed that a sigE mutant of M. tuberculosis was more attenuated and more efficacious than BCG in a mouse model of infection. In this paper, we describe the construction and characterization of an M. tuberculosis sigE fadD26 unmarked double mutant fulfilling the criteria of the Geneva Consensus for entering human clinical trials. The data presented suggest that this mutant is even more attenuated and slightly more efficacious than the previous sigE mutant in different mouse models of infection and is equivalent to BCG in a guinea pig model of infection.


Assuntos
Ligases/deficiência , Mycobacterium tuberculosis/imunologia , Fator sigma/deficiência , Vacinas contra a Tuberculose/imunologia , Tuberculose Pulmonar/prevenção & controle , Animais , Proteínas de Bactérias , Modelos Animais de Doenças , Cobaias , Camundongos , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/patogenicidade , Vacinas contra a Tuberculose/efeitos adversos , Vacinas contra a Tuberculose/genética , Vacinas Atenuadas/efeitos adversos , Vacinas Atenuadas/genética , Vacinas Atenuadas/imunologia , Virulência
4.
Vet Res ; 50(1): 82, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31615555

RESUMO

Effective vaccines against tuberculosis (TB) are needed in order to prevent TB transmission in human and animal populations. Evaluation of TB vaccines may be facilitated by using reliable animal models that mimic host pathophysiology and natural transmission of the disease as closely as possible. In this study, we evaluated the immunogenicity and efficacy of two attenuated vaccines, BCG and MTBVAC, after each was given to 17 goats (2 months old) and then exposed for 9 months to goats infected with M. caprae. In general, MTBVAC-vaccinated goats showed higher interferon-gamma release than BCG vaccinated goats in response to bovine protein purified derivative and ESAT-6/CFP-10 antigens and the response was significantly higher than that observed in the control group until challenge. All animals showed lesions consistent with TB at the end of the study. Goats that received either vaccine showed significantly lower scores for pulmonary lymph nodes and total lesions than unvaccinated controls. Both MTBVAC and BCG vaccines proved to be immunogenic and effective in reducing severity of TB pathology caused by M. caprae. Our model system of natural TB transmission may be useful for evaluating and optimizing vaccines.


Assuntos
Vacina BCG/imunologia , Doenças das Cabras/imunologia , Imunogenicidade da Vacina/imunologia , Mycoplasma/fisiologia , Vacinas contra a Tuberculose/imunologia , Tuberculose/veterinária , Animais , Doenças das Cabras/transmissão , Cabras , Imunidade Celular/efeitos dos fármacos , Imunidade Celular/imunologia , Imunidade Humoral/efeitos dos fármacos , Imunidade Humoral/imunologia , Tuberculose/imunologia , Tuberculose/transmissão , Vacinas Atenuadas/imunologia
5.
BMC Infect Dis ; 19(1): 568, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31262260

RESUMO

BACKGROUND: With the aim of preparing a more effective, safe and economical vaccine for tuberculosis, inhalable live mycobacterium formulations were evaluated. METHODS: Alginate particles in the size range of 2-4 µm were prepared by encapsulating live Bacille Calmette-Guérin (BCG) and "Mycobacterium indicus pranii" (MIP). These particles were characterized for their size, stability and release profile. Mice were immunized with liquid aerosol or dry powder aerosol (DPA) alginate encapsulated mycobacterium particles and their in-vitro recall response and infection with mycobacterium H37Rv were investigated. RESULTS: It was found that the DPA of alginate encapsulated mycobacterium particles invoked superior immune response and provided higher protection in mice than the liquid aerosol. The BCG encapsulated in alginate particles (BEAP) and MIP encapsulated in alginate particles (MEAP) were engulfed by bone marrow dendritic cells (BMDCs) and co-localized with lysosome. The MEAP/BEAP activated BMDCs exhibited higher chemotaxis movement and had enhanced ability of antigen presentation to T cells. The in-vitro recall response of BEAP/MEAP immunized mice when compared in terms of proliferation index and Interferon gamma (IFN-gamma) released by splenocytes and mediastinal lymph node cells was found to be higher than mice immunized by liquid aerosol of BCG/MIP. Finally, different groups of immunized mice were infected with M. tb H37Rv and after 16 weeks the Colony forming units (CFUs) in lung and spleen estimated. The bacilli burden in the BEAP/MEAP immunized mice was significantly less than the respective liquid aerosol immunized mice and the histopathology of BEAP/MEAP immunized mice lungs showed very little damage. CONCLUSIONS: These inhale-able vaccines formulation of alginate coated live mycobacterium are more immunogenic as compared to the aerosol of bacilli and they provide better protection in mice when infected with H37Rv.


Assuntos
Aerossóis/administração & dosagem , Pulmão/imunologia , Vacinas contra a Tuberculose/farmacologia , Tuberculose/prevenção & controle , Alginatos/química , Animais , Vacina BCG/imunologia , Sistemas de Liberação de Medicamentos/métodos , Interferon gama/imunologia , Pulmão/efeitos dos fármacos , Pulmão/microbiologia , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Complexo Mycobacterium avium/química , Complexo Mycobacterium avium/imunologia , Mycobacterium bovis/química , Mycobacterium bovis/imunologia , Mycobacterium tuberculosis/imunologia , Mycobacterium tuberculosis/patogenicidade , Baço/microbiologia , Linfócitos T/imunologia , Linfócitos T/microbiologia , Tuberculose/imunologia , Vacinas contra a Tuberculose/administração & dosagem , Vacinas contra a Tuberculose/imunologia , Vacinação/métodos
6.
Int Rev Immunol ; 38(4): 172-179, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31244354

RESUMO

Induction of Th1 (cell-mediated) immunity and associated production of IFN-γ by CD4+ T cells has been widely used as a marker of protective immunity against tuberculosis (TB). This is based on two assumptions. The first is the widely accepted view that Mycobacterium tuberculosis (Mtb), the causative agent of TB is an obligate intracellular pathogen, and the second is based on the Th1/Th2 paradigm, which posits that polarization of CD4+ T cells into type1 (cell-mediated) and type 2 (humoral) is central for proper induction of protective immunity against pathogens. However, almost all licensed vaccines currently in use are primarily anti-body based whether intracellular or extra-cellular. In addition, converging data from both animal models and humans indicate that the production of IFN-γ alone is not sufficient to confer protection against TB. In addition, a substantial body of the literature suggests that, in addition to Th1 cells, antibody classes and sub-classes are protective against TB. In a recent study, we have shown that there is a synergy between IFN-γ (cell-mediated) and IgA (humoral) in human population in an endemic setting. In this review, current data from both animal and human studies that support mixed Th1 and Th2 responses that are protective against Mtb and other pathogens are presented.


Assuntos
Mycobacterium tuberculosis/imunologia , Células Th1/imunologia , Células Th2/imunologia , Tuberculose/imunologia , Animais , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/imunologia , Humanos , Interferon gama/imunologia , Mycobacterium tuberculosis/patogenicidade , Vacinas contra a Tuberculose/imunologia
7.
Microbiol Immunol ; 63(8): 316-327, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31254409

RESUMO

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb) and remains a major cause of morbidity and mortality worldwide. In the host's immune response system, T cells play a critical role in mediating protection against Mtb infection, but the role of CD8+ T cells is still controversial. We evaluated the phenotypical characterization and cytotoxic ability of CD8+ T cells by flow cytometry-based assay. Cytokine levels in serum were measured by multiplex cytokine assay. Our data show that cells from TB patients have an increased percentage of peripheral blood CD8+ αß+ T (p = 0.02) and CD56+ CD8+ T (p = 0.02) and a decreased frequency of NKG2D+ CD8+ T (p = 0.02) compared with healthy donors. Unlike CD8+ T cells from healthy donors, CD8+ T cells from TB patients exhibit greater cytotoxicity, mediated by HLA class I molecules, on autologous monocytes in the presence of mycobacterial antigens (p = 0.005). Finally, TB patients have a proinflammatory profile characterized by serum high level of TNF-α (p = 0.02) and IL-8 (p = 0.0001), but, interestingly, IL-4 (p = 0.002) was also increased compared with healthy donors. Our data show evidence regarding the highly cytotoxic status of CD8+ T cells in Mtb infection. These cytotoxic cells restricted to HLA-A, B, and C could be used to optimize strategies for designing new TB vaccines or for identifying markers of disease progression.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Citotoxinas/toxicidade , Mycobacterium tuberculosis/imunologia , Tuberculose/imunologia , Adolescente , Adulto , Antígenos de Bactérias/imunologia , Citocinas/sangue , Feminino , Citometria de Fluxo , Antígenos HLA-A/imunologia , Antígenos HLA-B/imunologia , Antígenos HLA-C/imunologia , Humanos , Interleucina-4/sangue , Interleucina-8/sangue , Masculino , Pessoa de Meia-Idade , Vacinas contra a Tuberculose/imunologia , Fator de Necrose Tumoral alfa/sangue , Adulto Jovem
8.
Curr Pharm Biotechnol ; 20(6): 446-458, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31208308

RESUMO

Tuberculosis (TB) is an infectious disease that mainly affects the lungs and spreads to other organs of the body through the haematogenous route. It is one of the ten major causes of mortality worldwide. India has the highest incidence of new- and multidrug-resistant (MDR) - TB cases in the world. Bacille Calmette-Guerin (BCG) is the vaccine commonly available against TB. BCG does offer some protection against serious forms of TB in childhood but its protective effect wanes with age. Many new innovative strategies are being trailed for the development of effective and potent vaccines like mucosal- and epitope-based vaccines, which may replace BCG or boost BCG responses. The use of nanotechnology for diagnosis and treatment of TB is also in the pipeline along with many other vaccines, which are under clinical trials. Further, in-silico models were developed for finding new drug targets and designing drugs against Mycobacterium tuberculosis (Mtb). These models offer the benefit of computational experiments which are easy, inexpensive and give quick results. This review will focus on the available treatments and new approaches to develop potent vaccines for the treatment of TB.


Assuntos
Mycobacterium tuberculosis/imunologia , Vacinas contra a Tuberculose/imunologia , Tuberculose , Animais , Criança , Desenho de Drogas , Humanos , Índia , Tuberculose/diagnóstico , Tuberculose/microbiologia , Tuberculose/prevenção & controle , Vacinação
9.
PLoS One ; 14(5): e0217091, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31120957

RESUMO

BACKGROUND: DAR-901 is an inactivated whole cell tuberculosis booster vaccine, prepared using a new scalable, broth-grown method from the master cell bank of SRL172, a vaccine previously shown to prevent tuberculosis. This study examined whether DAR-901 (a) induces CD4+ T cell cytokine profiles previously proposed as correlates of protection and (b) has a specific vaccine-induced immunological signature compared to BCG or placebo. METHODS: We analysed CD4+ T cell cytokine immune responses from 10 DAR-901 recipients, 9 BCG recipients and 9 placebo recipients from the Phase I DAR-901 MDES trial. In that study, HIV-negative, IGRA-negative participants with prior BCG immunization were randomized (double-blind) to receive three intradermal injections of DAR-901 or saline placebo or two injections of saline placebo followed by an intradermal injection of BCG. Antigen-specific functional and phenotypic CD4+ T cell responses along with effector phenotype of responder cells were measured by intracellular cytokine staining. RESULTS: DAR-901 recipients exhibited increased DAR-901 antigen-specific polyfunctional or bifunctional T cell responses compared to baseline. Vaccine specific CD4+ IFNγ, IL2, TNFα and any cytokine responses peaked at 7 days post-dose 3. Th1 responses predominated, with most responder cells exhibiting a polyfunctional effector memory phenotype. BCG induced greater CD4+ T cell responses than placebo while the more modest DAR-901 responses did not differ from placebo. Neither DAR-901 nor BCG induced substantial or sustained Th17 /Th22 cytokine responses. CONCLUSION: DAR-901, a TB booster vaccine grown from the master cell bank of SRL 172 which was shown to prevent TB, induced low magnitude polyfunctional effector memory CD4+ T cell responses. DAR-901 responses were lower than those induced by BCG, a vaccine that has been shown ineffective as a booster to prevent tuberculosis disease. These results suggest that induction of higher levels of CD4+ cytokine stimulation may not be a critical or pre-requisite characteristic for candidate TB vaccine boosters. TRIAL REGISTRATION: ClinicalTrials.gov NCT02063555.


Assuntos
Vacina BCG/imunologia , Linfócitos T CD4-Positivos/imunologia , Citocinas/metabolismo , Mycobacterium tuberculosis/imunologia , Vacinas contra a Tuberculose/imunologia , Tuberculose/imunologia , Tuberculose/prevenção & controle , Adolescente , Adulto , Idoso , Vacina BCG/administração & dosagem , Método Duplo-Cego , Feminino , Humanos , Imunização Secundária , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/patogenicidade , Tuberculose/metabolismo , Vacinas contra a Tuberculose/administração & dosagem , Vacinas contra a Tuberculose/normas , Adulto Jovem
10.
Int J Nanomedicine ; 14: 3129-3143, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31118627

RESUMO

Background: Bacillus Calmette-Guérin, the attenuated strain of Mycobacterium bovis, remains the only available vaccine against tuberculosis (TB). However, its ineffectiveness in adults against pulmonary TB and varied protective efficacy (0-80%) speak to an urgent need for the development of an improved and efficient TB vaccine. In this milieu, poly(lactic-co-glycolic acid) (PLGA), is a preferential candidate, due to such properties as biocompatibility, targeted delivery, sustained antigen release, and atoxic by-products. Methods: In this study, we formulated PLGA nanoparticles (NPs) encapsulating the bivalent H1 antigen, a fusion of Mycobacterium tuberculosis (Mtb) Ag85B and ESAT6 proteins, and investigated its role in immunomodulation and protection against Mtb challenge. Using the classical water-oil-water solvent-evaporation method, H1-NPs were prepared, with encapsulation efficiency of 86.1%±3.2%. These spherical NPs were ~244.4±32.6 nm in diameter, with a negatively charged surface (ζ-potential -4±0.6 mV). Results: Under physiological conditions, NPs degraded slowly and the encapsulated H1 antigen was released over a period of weeks. As a proof-of-concept vaccine candidate, H1 NPs were efficiently internalized by the THP-1 human macrophages. Six weeks after a single-dose vaccination, H1 NP-immunized C57BL/6J mice showed significant increase in the production of total serum IgG (P<0.0001) and its isotypes compared to H1 alone, IgG2a being the predominant one, followed by IgG1. Further, the cytokine-release profile of antigen-stimulated splenocyteculture supernatant indicated a strong TH1-biased immunoresponse in H1 NP-vaccinated mice, with ~6.03- and ~2.8-fold increase in IFNγ and TNFα cytokine levels, and ~twofold and 1.6 fold increase in IL4 and IL10 cytokines, respectively, compared to H1 alone-immunized mice. In protection studies, H1 NP-vaccinated mice displayed significant reductions in lung and spleen bacillary load (P<0.05) at 5-week post-Mtb H37Rv challenge and prolonged survival, with a mean survival time of 177 days, compared to H1 alone-vaccinated mice (mean survival time 80 days). Conclusion: Altogether, our findings highlight the significance of the H1-PLGA nanoformulation in terms of providing long-term protection in mice with a single dose.


Assuntos
Imunidade , Nanopartículas/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Proteínas Recombinantes de Fusão/metabolismo , Tuberculose/imunologia , Tuberculose/prevenção & controle , Animais , Citocinas/metabolismo , Relação Dose-Resposta Imunológica , Liberação Controlada de Fármacos , Endocitose , Epitopos , Feminino , Humanos , Imunidade Humoral , Imunização , Imunoglobulina G/metabolismo , Macrófagos/metabolismo , Camundongos Endogâmicos C57BL , Mycobacterium tuberculosis/imunologia , Nanopartículas/administração & dosagem , Nanopartículas/ultraestrutura , Baço/citologia , Baço/imunologia , Análise de Sobrevida , Células THP-1 , Células Th1/imunologia , Vacinas contra a Tuberculose/imunologia , Vacinação
11.
PLoS Med ; 16(4): e1002790, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-31039172

RESUMO

BACKGROUND: There is an urgent need for an effective tuberculosis (TB) vaccine. Heterologous prime-boost regimens induce potent cellular immunity. MVA85A is a candidate TB vaccine. This phase I clinical trial was designed to evaluate whether alternating aerosol and intradermal vaccination routes would boost cellular immunity to the Mycobacterium tuberculosis antigen 85A (Ag85A). METHODS AND FINDINGS: Between December 2013 and January 2016, 36 bacille Calmette-Guérin-vaccinated, healthy UK adults were randomised equally between 3 groups to receive 2 MVA85A vaccinations 1 month apart using either heterologous (Group 1, aerosol-intradermal; Group 2, intradermal-aerosol) or homologous (Group 3, intradermal-intradermal) immunisation. Bronchoscopy and bronchoalveolar lavage (BAL) were performed 7 days post-vaccination. Adverse events (AEs) and peripheral blood were collected for 6 months post-vaccination. The laboratory and bronchoscopy teams were blinded to treatment allocation. One participant was withdrawn and was replaced. Participants were aged 21-42 years, and 28/37 were female. In a per protocol analysis, aerosol delivery of MVA85A as a priming immunisation was well tolerated and highly immunogenic. Most AEs were mild local injection site reactions following intradermal vaccination. Transient systemic AEs occurred following vaccination by both routes and were most frequently mild. All respiratory AEs following primary aerosol MVA85A (Group 1) were mild. Boosting an intradermal MVA85A prime with an aerosolised MVA85A boost 1 month later (Group 2) resulted in transient moderate/severe respiratory and systemic AEs. There were no serious adverse events and no bronchoscopy-related complications. Only the intradermal-aerosol vaccination regimen (Group 2) resulted in modest, significant boosting of the cell-mediated immune response to Ag85A (p = 0.027; 95% CI: 28 to 630 spot forming cells per 1 × 106 peripheral blood mononuclear cells). All 3 regimens induced systemic cellular immune responses to the modified vaccinia virus Ankara (MVA) vector. Serum antibodies to Ag85A and MVA were only induced after intradermal vaccination. Aerosolised MVA85A induced significantly higher levels of Ag85A lung mucosal CD4+ and CD8+ T cell cytokines compared to intradermal vaccination. Boosting with aerosol-inhaled MVA85A enhanced the intradermal primed responses in Group 2. The magnitude of BAL MVA-specific CD4+ T cell responses was lower than the Ag85A-specific responses. A limitation of the study is that while the intradermal-aerosol regimen induced the most potent cellular Ag85A immune responses, we did not boost the last 3 participants in this group because of the AE profile. Timing of bronchoscopies aimed to capture peak mucosal response; however, peak responses may have occurred outside of this time frame. CONCLUSIONS: To our knowledge, this is the first human randomised clinical trial to explore heterologous prime-boost regimes using aerosol and systemic routes of administration of a virally vectored vaccine. In this trial, the aerosol prime-intradermal boost regime was well tolerated, but intradermal prime-aerosol boost resulted in transient but significant respiratory AEs. Aerosol vaccination induced potent cellular Ag85A-specific mucosal and systemic immune responses. Whilst the implications of inducing potent mucosal and systemic immunity for protection are unclear, these findings are of relevance for the development of aerosolised vaccines for TB and other respiratory and mucosal pathogens. TRIAL REGISTRATION: ClinicalTrials.gov NCT01954563.


Assuntos
Aciltransferases/imunologia , Antígenos de Bactérias/imunologia , Vacinas contra a Tuberculose/administração & dosagem , Tuberculose/prevenção & controle , Administração por Inalação , Adulto , Aerossóis , Esquema de Medicação , Feminino , Vetores Genéticos/administração & dosagem , Vetores Genéticos/efeitos adversos , Humanos , Imunização Secundária , Imunogenicidade da Vacina , Injeções Intradérmicas , Masculino , Mycobacterium tuberculosis/imunologia , Método Simples-Cego , Tuberculose/imunologia , Vacinas contra a Tuberculose/efeitos adversos , Vacinas contra a Tuberculose/imunologia , Vacinação/efeitos adversos , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/efeitos adversos , Vacinas Sintéticas/imunologia , Adulto Jovem
12.
Scand J Immunol ; 90(2): e12774, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31054193

RESUMO

Tuberculosis (TB) remains one of a major health problem worldwide. Tuberculosis vaccine research has made an extraordinary progress over the past few years. However, there is still no replacement for the Bacillus Calmette-Guérin vaccine, the only TB vaccine licensed for human use. Therefore, the discovery and development of new TB vaccines remains a priority. This article discusses current strategies used to diversify TB vaccines and includes discussion of the status of efforts to improve protection against Mycobacterium tuberculosis (M tb) infection or TB disease by developing new and safe TB vaccines. This article also highlights the current research efforts in immune-enhancing approaches to improve vaccination efficacy. The development of more effective TB vaccines might have significant impact on global TB control.


Assuntos
Mycobacterium tuberculosis/imunologia , Vacinas contra a Tuberculose/imunologia , Tuberculose Pulmonar/prevenção & controle , Humanos , Tuberculose Pulmonar/imunologia , Vacinação , Vacinas Atenuadas/imunologia
13.
Scand J Immunol ; 90(4): e12772, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31055842

RESUMO

Bacillus Calmette-Guérin (BCG) remains the only licensed vaccine against human tuberculosis (TB). BCG is a live-attenuated strain of Mycobacterium bovis, with limitations in efficacy against respiratory TB, the most common form of the disease responsible for transmission. However, continues to be used in the immunization programmes of different countries in the absence of another alternative. In order to improve BCG efficacy against pulmonary TB, in the current clinical TB vaccine pipeline, there are live-attenuated TB vaccines to replace BCG. This review discusses the current status of the development of live vaccine candidates designed to replace BCG from the rational strategies and immunological challenges to its clinical trial and identify key areas in the next years considered essential to confer improved safety and efficacy over BCG.


Assuntos
Mycobacterium bovis/imunologia , Mycobacterium tuberculosis/fisiologia , Vacinas contra a Tuberculose/imunologia , Tuberculose Pulmonar/imunologia , Vacinas Atenuadas/imunologia , Animais , Humanos , Vacinação
14.
Tuberculosis (Edinb) ; 116S: S34-S41, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31064713

RESUMO

Among the various strategies to improve vaccines against infectious diseases, targeting of antigens to dendritic cells (DCs), which are professional antigen presenting cells (APCs), has received increased attention in recent years. Here, we investigated whether a synthetic peptide region named RVG, originated from Rabies Virus Glycoprotein that binds to the α-7 subunit of the nicotinic acetylcholine receptors (AchR-α7) of APCs, could be used for the delivery of Mycobacterium tuberculosis (Mtb) peptide antigens to DCs and macrophages. Mouse bone marrow derived DCs (BMDCs) and human THP-1 macrophages stimulated with RVG fused peptide epitopes 85B241 and 85B96 (represent Ag85B241-256 and Ag85B96-111, respectively) from antigen 85B (Ag85B) of Mtb showed enhanced antigen presentation as compared to unfused peptide epitopes and BCG. Further, BMDCs stimulated with RVG fused 85B241 showed higher levels of IL-12 positive cells. Consistent with in vitro data, splenocytes of mice immunized with RVG-85B241 showed increased number of antigen specific IFN-γ, IL-2, and TNF-α producing cells in relation to splenocytes from mice immunized with 85B241 alone. These results suggest that RVG may be a promising tool to develop effective alternate vaccines against tuberculosis (TB).


Assuntos
Aciltransferases/metabolismo , Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Células Dendríticas/metabolismo , Glicoproteínas/metabolismo , Macrófagos/metabolismo , Fragmentos de Peptídeos/metabolismo , Vacinas contra a Tuberculose/metabolismo , Tuberculose/prevenção & controle , Proteínas Virais/metabolismo , Aciltransferases/administração & dosagem , Aciltransferases/genética , Aciltransferases/imunologia , Animais , Antígenos de Bactérias/administração & dosagem , Antígenos de Bactérias/genética , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/administração & dosagem , Proteínas de Bactérias/genética , Proteínas de Bactérias/imunologia , Citocinas/imunologia , Citocinas/metabolismo , Células Dendríticas/imunologia , Epitopos , Glicoproteínas/genética , Humanos , Imunização , Macrófagos/imunologia , Camundongos Endogâmicos C57BL , Fragmentos de Peptídeos/genética , Proteínas Recombinantes de Fusão/metabolismo , Células THP-1 , Tuberculose/imunologia , Tuberculose/microbiologia , Vacinas contra a Tuberculose/administração & dosagem , Vacinas contra a Tuberculose/genética , Vacinas contra a Tuberculose/imunologia , Vacinas Conjugadas/imunologia , Vacinas Conjugadas/metabolismo , Proteínas Virais/genética
15.
Biologicals ; 59: 6-11, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31014910

RESUMO

According to some difficulties against tuberculosis (TB) vaccination, development of new TB vaccines has been noted in recent years. Selection of proper route for vaccination is one of the most important factors for induction of good immune responses. Hence, in this study, the effects of different administration routes, including intranasal (I.N), subcutaneous (S.C) and intramuscular (I.M) on immune responses against Mycobacterium tuberculosis ESAT-6/CFP-10 recombinant protein has been considered. Recombinant ESAT-6/CFP-10 protein with or without adjuvant (MF59 or cholera toxin B (CTB)) was administered by three routes of I.M, I.N and S.C to mice for three times. Then, the levels of specific antibodies, lymphocyte proliferation and IFN-γ/IL-5 cytokine profile have been carried out to evaluate the humoral and cellular responses. The results showed that the titers of specific antibodies were quickly elevated in S.C and I.M groups after first immunization. Otherwise, the raise of antibody has delay in the I.N immunized animals. The levels of IFN-γ and lymphocyte proliferation have been increased in all of vaccinated groups. However, the I.N immunized mice have lower levels of IL-5 production. Based on our finding, the ESAT-6/CFP-10 recombinant protein is a potent stimulator of immune responses in all of three immunization strategies. However intranasal administration of this antigen has tended to reinforcement of cellular immune responses.


Assuntos
Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Mycobacterium tuberculosis/imunologia , Proteínas Recombinantes/imunologia , Vacinas contra a Tuberculose/imunologia , Tuberculose/imunologia , Administração Intranasal , Animais , Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Feminino , Imunidade Celular/efeitos dos fármacos , Imunidade Celular/imunologia , Imunidade Humoral/efeitos dos fármacos , Imunidade Humoral/imunologia , Injeções Intramusculares , Injeções Subcutâneas , Camundongos , Mycobacterium tuberculosis/efeitos dos fármacos , Tuberculose/microbiologia , Tuberculose/prevenção & controle , Vacinas contra a Tuberculose/administração & dosagem , Vacinação/métodos
16.
PLoS One ; 14(3): e0213536, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30849108

RESUMO

A safe and effective adjuvant is necessary to induce reliable protective efficacy of the protein-based vaccines against tuberculosis (TB). Mycobacterial components, such as synthetic cord factor and arabinogalactan, have been used as one of the adjuvant components. Mycobacterium bovis bacillus Calmette- Guérin cell-wall skeleton (BCG-CWS) has been used as an effective immune-stimulator. However, it is not proven whether BCG-CWS can be an effective adjuvant for the subunit protein vaccine of TB. In this study, we demonstrated that the BCG-CWS effectively coupled with Ag85B and enhanced the conjugated Ag85B activity on the maturation of dendritic cells (DCs). Ag85B-BCG-CWS-matured DCs induced significant Th1 and Th17 responses when compared to BCG-CWS or Ag85B alone. In addition, significant Ag85B-specific Th1 and Th17 responses were induced in Ag85B-BCG-CWS-immunized mice before infection with M. tuberculosis and maintained after infection. Moreover, Ag85B-BCG-CWS showed significant protective effect comparable to live BCG at 6 weeks after infection and maintained its protective efficacy at 32 weeks post-challenge, whereas live BCG did not. These results suggest that the BCG-CWS may be an effective adjuvant candidate for a protein-based vaccine against TB.


Assuntos
Antígenos de Bactérias/imunologia , Parede Celular/imunologia , Mycobacterium bovis/imunologia , Mycobacterium tuberculosis/imunologia , Células Th1/imunologia , Células Th2/imunologia , Vacinas contra a Tuberculose/imunologia , Tuberculose/imunologia , Adjuvantes Imunológicos/farmacologia , Animais , Antígenos de Bactérias/farmacologia , Feminino , Camundongos , Células Th2/patologia , Tuberculose/patologia , Tuberculose/prevenção & controle , Vacinas contra a Tuberculose/farmacologia
17.
Proc Natl Acad Sci U S A ; 116(13): 6371-6378, 2019 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-30850538

RESUMO

Tuberculosis (TB) remains a leading killer among infectious diseases, and a better TB vaccine is urgently needed. The critical components and mechanisms of vaccine-induced protection against Mycobacterium tuberculosis (Mtb) remain incompletely defined. Our previous studies demonstrate that Vγ2Vδ2 T cells specific for (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP) phosphoantigen are unique in primates as multifunctional effectors of immune protection against TB infection. Here, we selectively immunized Vγ2Vδ2 T cells and assessed the effect on infection in a rhesus TB model. A single respiratory vaccination of macaques with an HMBPP-producing attenuated Listeria monocytogenes (Lm ΔactA prfA*) caused prolonged expansion of HMBPP-specific Vγ2Vδ2 T cells in circulating and pulmonary compartments. This did not occur in animals similarly immunized with an Lm ΔgcpE strain, which did not produce HMBPP. Lm ΔactA prfA* vaccination elicited increases in Th1-like Vγ2Vδ2 T cells in the airway, and induced containment of TB infection after pulmonary challenge. The selective immunization of Vγ2Vδ2 T cells reduced lung pathology and mycobacterial dissemination to extrapulmonary organs. Vaccine effects coincided with the fast-acting memory-like response of Th1-like Vγ2Vδ2 T cells and tissue-resident Vγ2Vδ2 effector T cells that produced both IFN-γ and perforin and inhibited intracellular Mtb growth. Furthermore, selective immunization of Vγ2Vδ2 T cells enabled CD4+ and CD8+ T cells to mount earlier pulmonary Th1 responses to TB challenge. Our findings show that selective immunization of Vγ2Vδ2 T cells can elicit fast-acting and durable memory-like responses that amplify responses of other T cell subsets, and provide an approach to creating more effective TB vaccines.


Assuntos
Imunização , Ativação Linfocitária/efeitos dos fármacos , Vacinas contra a Tuberculose/imunologia , Tuberculose/imunologia , Tuberculose/prevenção & controle , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/imunologia , Linfócitos T CD8-Positivos/imunologia , Modelos Animais de Doenças , Feminino , Memória Imunológica/imunologia , Interferon gama/metabolismo , Listeria monocytogenes/genética , Listeria monocytogenes/imunologia , Pulmão/imunologia , Pulmão/patologia , Macaca mulatta/imunologia , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/imunologia , Mycobacterium tuberculosis/efeitos dos fármacos , Organofosfatos , Fatores de Terminação de Peptídeos/genética , Fatores de Terminação de Peptídeos/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Subpopulações de Linfócitos T/imunologia , Tuberculose/patologia , Vacinas contra a Tuberculose/farmacologia , Vacinas Atenuadas/imunologia
18.
Eur J Clin Microbiol Infect Dis ; 38(3): 449-456, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30719592

RESUMO

Vaccines such as Vaccinia or BCG have non-specific effects conferring protection against other diseases than their target infection, which are likely partly mediated through induction of innate immune memory (trained immunity). MVA85A, a recombinant strain of modified Vaccinia Ankara (MVA), has been suggested as an alternative vaccine against tuberculosis, but its capacity to induce positive or negative non-specific immune effects has not been studied. This study assesses whether Vaccinia and MVA are able to induce trained innate immunity in monocytes. Human primary monocytes were primed in an in vitro model with Vaccinia or MVA for 1 day, after which the stimulus was washed off and the cells were rechallenged with unrelated microbial ligands after 1 week. Heterologous cytokine responses were assessed and the capacity of MVA to induce epigenetic changes at the level of cytokine genes was investigated using chromatin immunoprecipitation and pharmacological inhibitors. Monocytes trained with Vaccinia showed significantly increased IL-6 and TNF-α production to stimulation with non-related stimuli, compared to non-trained monocytes. In contrast, monocytes primed with MVA showed significant decreased heterologous IL-6 and TNF-α responses, an effect which was abrogated by the addition of a histone methyltransferase inhibitor. No effects on H3K4me3 were observed after priming with MVA. It can be thus concluded that Vaccinia induces trained immunity in vitro, whereas MVA induces innate immune tolerance. This suggests the induction of trained immunity as an immunological mechanism involved in the non-specific effects of Vaccinia vaccination and points to a possible explanation for the lack of effect of MVA85A against tuberculosis.


Assuntos
Imunidade Heteróloga , Vacinas contra a Tuberculose/imunologia , Vírus Vaccinia/imunologia , Vaccinia/imunologia , Vacinas Virais/imunologia , Histona Metiltransferases/antagonistas & inibidores , Humanos , Imunidade Heteróloga/efeitos dos fármacos , Imunidade Inata , Interleucina-6/metabolismo , Leucócitos Mononucleares/imunologia , Pemetrexede/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Vírus Vaccinia/genética
20.
PLoS One ; 14(2): e0212751, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30794653

RESUMO

Mycobacterium bovis Bacillus Calmette-Guérin (BCG) is a live attenuated vaccine for use against tuberculosis (TB); however, it is known to reduce childhood mortality from infections other than TB. The unspecific protection induced by BCG vaccination has been associated with the induction of memory-like traits of the innate immune system identified as 'trained' immunity. In humans and mouse models, in vitro and in vivo BCG training leads to enhanced production of monocyte-derived proinflammatory cytokines in response to secondary unrelated bacterial and fungal pathogens. While BCG has been studied extensively for its ability to induce innate training in humans and mouse models, BCG's nonspecific protective effects have not been defined in agricultural species. Here, we show that in vitro BCG training induces a functional change in bovine monocytes, characterized by increased transcription of proinflammatory cytokines upon restimulation with the toll-like receptor agonists. Importantly, in vivo, aerosol BCG vaccination in young calves also induced a 'trained' phenotype in circulating peripheral blood mononuclear cells (PBMCs), that lead to a significantly enhanced TLR-induced proinflammatory cytokine response and changes in cellular metabolism compared to PBMCs from unvaccinated control calves. Similar to the long-term training effects of BCG reported in humans, our results suggest that in young calves, the effects of BCG induced innate training can last for at least 3 months in circulating immune populations. Interestingly, however, aerosol BCG vaccination did not 'train' the innate immune response at the mucosal level, as alveolar macrophages from aerosol BCG vaccinated calves did not mount an enhanced inflammatory response to secondary stimulation, compared to cells isolated from control calves. Together, our results suggest that, like mice and humans, the innate immune system of calves can be 'trained'; and that BCG vaccination could be used as an immunomodulatory strategy to reduce disease burden in juvenile food animals before the adaptive immune system has fully matured.


Assuntos
Imunidade Inata , Imunidade nas Mucosas , Mycobacterium bovis/imunologia , Vacinas contra a Tuberculose/farmacologia , Tuberculose Bovina/imunologia , Vacinação , Aerossóis , Animais , Bovinos , Citocinas/imunologia , Feminino , Humanos , Macrófagos Alveolares/imunologia , Masculino , Camundongos , Receptores Toll-Like/imunologia , Vacinas contra a Tuberculose/imunologia , Tuberculose Bovina/prevenção & controle
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