51
|
Dalmia N, Ramsay AJ. Prime-boost approaches to tuberculosis vaccine development. Expert Rev Vaccines 2013; 11:1221-33. [PMID: 23176655 DOI: 10.1586/erv.12.94] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Four individuals die from active TB disease each minute, while at least 2 billion are latently infected and at risk for disease reactivation. BCG, the only licensed TB vaccine, is effective in preventing childhood forms of TB; however its poor efficacy in adults, emerging drug-resistant TB strains and tedious chemotherapy regimes, warrant the development of novel prophylactic measures. Designing safe and effective vaccines against TB will require novel approaches on several levels, including the administration of rationally selected mycobacterial antigens in efficient delivery vehicles via optimal immunization routes. Given the primary site of disease manifestation in the lungs, development of mucosal immunization strategies to generate protective immune responses both locally, and in the circulation, may be important for effective TB prophylaxis. This review focuses on prime-boost immunization strategies currently under investigation and highlights the potential of mucosal delivery and rational vaccine design based on systems biology.
Collapse
Affiliation(s)
- Neha Dalmia
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, 1901 Perdido Street, New Orleans, LA 70112, USA
| | | |
Collapse
|
52
|
Horvath CN, Xing Z. Immunization Strategies Against Pulmonary Tuberculosis: Considerations of T Cell Geography. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 783:267-78. [DOI: 10.1007/978-1-4614-6111-1_14] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
|
53
|
Pitt JM, Blankley S, McShane H, O'Garra A. Vaccination against tuberculosis: how can we better BCG? Microb Pathog 2012; 58:2-16. [PMID: 23257069 DOI: 10.1016/j.micpath.2012.12.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 12/05/2012] [Accepted: 12/06/2012] [Indexed: 01/01/2023]
Abstract
Tuberculosis remains one of the most significant human diseases of the developing world, accounting for 3800 worldwide deaths per day. Although we currently have a vaccine for tuberculosis, BCG, this is insufficient at protecting from adult pulmonary tuberculosis in the parts of the world where a good vaccine is most needed. This has prompted the search for new vaccination strategies that can protect better than BCG, or can boost BCG-induced immunity. We discuss these subjects in line with what is known of the immune responses to BCG and Mycobacterium tuberculosis - the etiological agent of the disease, as well as the particular difficulties facing development of new vaccines against tuberculosis. A greater understanding of the factors constituting optimal protection against Mycobacterium tuberculosis infection, as well as which pathogenic factors facilitate active disease, will accelerate the delivery of safe vaccines able to restrict active tuberculosis and thus impede contagion.
Collapse
Affiliation(s)
- Jonathan M Pitt
- Division of Immunoregulation, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | | | | | | |
Collapse
|
54
|
Li W, Deng G, Li M, Liu X, Wang Y. Roles of Mucosal Immunity against Mycobacterium tuberculosis Infection. Tuberc Res Treat 2012; 2012:791728. [PMID: 23213508 PMCID: PMC3504404 DOI: 10.1155/2012/791728] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 09/12/2012] [Accepted: 09/27/2012] [Indexed: 12/21/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), is one of the world's leading infectious causes of morbidity and mortality. As a mucosal-transmitted pathogen, Mtb infects humans and animals mainly through the mucosal tissue of the respiratory tract. Apart from providing a physical barrier against the invasion of pathogen, the major function of the respiratory mucosa may be to serve as the inductive sites to initiate mucosal immune responses and sequentially provide the first line of defense for the host to defend against this pathogen. A large body of studies in the animals and humans have demonstrated that the mucosal immune system, rather than the systemic immune system, plays fundamental roles in the host's defense against Mtb infection. Therefore, the development of new vaccines and novel delivery routes capable of directly inducing respiratory mucosal immunity is emphasized for achieving enhanced protection from Mtb infection. In this paper, we outline the current state of knowledge regarding the mucosal immunity against Mtb infection, including the development of TB vaccines, and respiratory delivery routes to enhance mucosal immunity are discussed.
Collapse
Affiliation(s)
- Wu Li
- Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western, Ningxia University, Yinchuan, Ningxia 750021, China
- College of Life Science, Ningxia University, 539 W. Helanshan Road, Xixia District, Yinchuan, Ningxia 750021, China
| | - Guangcun Deng
- Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western, Ningxia University, Yinchuan, Ningxia 750021, China
- College of Life Science, Ningxia University, 539 W. Helanshan Road, Xixia District, Yinchuan, Ningxia 750021, China
| | - Min Li
- Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western, Ningxia University, Yinchuan, Ningxia 750021, China
- College of Life Science, Ningxia University, 539 W. Helanshan Road, Xixia District, Yinchuan, Ningxia 750021, China
| | - Xiaoming Liu
- Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western, Ningxia University, Yinchuan, Ningxia 750021, China
- College of Life Science, Ningxia University, 539 W. Helanshan Road, Xixia District, Yinchuan, Ningxia 750021, China
| | - Yujiong Wang
- Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western, Ningxia University, Yinchuan, Ningxia 750021, China
- College of Life Science, Ningxia University, 539 W. Helanshan Road, Xixia District, Yinchuan, Ningxia 750021, China
| |
Collapse
|
55
|
Forrellad MA, Klepp LI, Gioffré A, Sabio y García J, Morbidoni HR, de la Paz Santangelo M, Cataldi AA, Bigi F. Virulence factors of the Mycobacterium tuberculosis complex. Virulence 2012; 4:3-66. [PMID: 23076359 PMCID: PMC3544749 DOI: 10.4161/viru.22329] [Citation(s) in RCA: 379] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The Mycobacterium tuberculosis complex (MTBC) consists of closely related species that cause tuberculosis in both humans and animals. This illness, still today, remains to be one of the leading causes of morbidity and mortality throughout the world. The mycobacteria enter the host by air, and, once in the lungs, are phagocytated by macrophages. This may lead to the rapid elimination of the bacillus or to the triggering of an active tuberculosis infection. A large number of different virulence factors have evolved in MTBC members as a response to the host immune reaction. The aim of this review is to describe the bacterial genes/proteins that are essential for the virulence of MTBC species, and that have been demonstrated in an in vivo model of infection. Knowledge of MTBC virulence factors is essential for the development of new vaccines and drugs to help manage the disease toward an increasingly more tuberculosis-free world.
Collapse
|
56
|
Hanif SNM, Garcia-Contreras L. Pharmaceutical aerosols for the treatment and prevention of tuberculosis. Front Cell Infect Microbiol 2012; 2:118. [PMID: 22973562 PMCID: PMC3435512 DOI: 10.3389/fcimb.2012.00118] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 08/23/2012] [Indexed: 01/13/2023] Open
Abstract
Historically, pharmaceutical aerosols have been employed for the treatment of obstructive airway diseases, such as asthma and chronic obstructive pulmonary disease, but in the past decades their use has been expanded to treat lung infections associated with cystic fibrosis and other respiratory diseases. Tuberculosis (TB) is acquired after inhalation of aerosol droplets containing the bacilli from the cough of infected individuals. Even though TB affects other organs, the lungs are the primary site of infection, which makes the pulmonary route an ideal alternative route to administer vaccines or drug treatments. Optimization of formulations and delivery systems for anti-TB vaccines and drugs, as well as the proper selection of the animal model to evaluate those is of paramount importance if novel vaccines or drug treatments are to be successful. Pharmaceutical aerosols for patient use are generated from metered dose inhalers, nebulizers, and dry powder inhalers (DPIs). In addition to the advantages of providing more efficient delivery of the drug, low cost, and portability, pharmaceutical dry powder aerosols are more stable than inhalable liquid dosage forms and do not require refrigeration. Methods to manufacture dry powders in respirable sizes include micronization, spray drying, and other proprietary technologies. Inhalable dry powders are characterized in terms of their drug content, particle size, and dispersibility to ensure deposition in the appropriate lung region and effective aerosolization from the device. These methods will be illustrated as they were applied for the manufacture and characterization of powders containing anti-tubercular agents and vaccines for pulmonary administration. The influence of formulation, selection of animal model, method of aerosol generation, and administration on the efficacy demonstrated in a given study will be illustrated by the evaluation of pharmaceutical aerosols of anti-TB drugs and vaccines in guinea pigs by our group.
Collapse
Affiliation(s)
- Shumaila N M Hanif
- Department of Pharmaceutical Sciences, Collage of Pharmacy, University of Oklahoma Health Sciences Center Oklahoma City, OK, USA
| | | |
Collapse
|
57
|
Protective efficacy of Mycobacterium indicus pranii against tuberculosis and underlying local lung immune responses in guinea pig model. Vaccine 2012; 30:6198-209. [DOI: 10.1016/j.vaccine.2012.07.061] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Revised: 06/29/2012] [Accepted: 07/24/2012] [Indexed: 11/18/2022]
|
58
|
Horvath CN, Shaler CR, Jeyanathan M, Zganiacz A, Xing Z. Mechanisms of delayed anti-tuberculosis protection in the lung of parenteral BCG-vaccinated hosts: a critical role of airway luminal T cells. Mucosal Immunol 2012; 5:420-31. [PMID: 22453678 DOI: 10.1038/mi.2012.19] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The immune mechanisms underlying unsatisfactory pulmonary mucosal protection by parenteral Bacillus Calmette-Guérin (BCG) immunization remain poorly understood. We found that parenteral BCG immunization failed to elicit airway luminal T cells (ALT) whereas it induced significant T cells in the lung interstitium. After Mycobacterium tuberculosis (M.tb) challenge, ALT remained missing for 10 days. The lack of ALT correlated with lack of lung protection for 14 days post-M.tb challenge. To further investigate the role of ALT, ALT were elicited in BCG-immunized animals by intranasal inoculation of M.tb culture-filtrate (CF) proteins. Installment of ALT by CF restored protection in the early phases of M.tb infection, which was linked to rapid increases in ALT, but not in lung interstitial T cells. Also, adoptive transfer of T cells to the airway lumen of BCG-immunized animals also accelerated protection. This study thus provides novel evidence that unsatisfactory lung protection by parenteral BCG immunization is due to delayed ALT recruitment after pulmonary M.tb exposure.
Collapse
Affiliation(s)
- C N Horvath
- McMaster Immunology Research Centre, M.G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | | | | | | | | |
Collapse
|
59
|
The HyVac4 subunit vaccine efficiently boosts BCG-primed anti-mycobacterial protective immunity. PLoS One 2012; 7:e39909. [PMID: 22768165 PMCID: PMC3386939 DOI: 10.1371/journal.pone.0039909] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Accepted: 06/02/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The current vaccine against tuberculosis (TB), BCG, has failed to control TB worldwide and the protective efficacy is moreover limited to 10-15 years. A vaccine that could efficiently boost a BCG-induced immune response and thus prolong protective immunity would therefore have a significant impact on the global TB-burden. METHODS/FINDINGS In the present study we show that the fusion protein HyVac4 (H4), consisting of the mycobacterial antigens Ag85B and TB10.4, given in the adjuvant IC31® or DDA/MPL effectively boosted and prolonged immunity induced by BCG, leading to improved protection against infection with virulent M. tuberculosis (M.tb). Increased protection correlated with an increased percentage of TB10.4 specific IFNγ/TNFα/IL-2 or TNFα/IL-2 producing CD4 T cells at the site of infection. Moreover, this vaccine strategy did not compromise the use of ESAT-6 as an accurate correlate of disease development/vaccine efficacy. Indeed both CD4 and CD8 ESAT-6 specific T cells showed significant correlation with bacterial levels. CONCLUSIONS/SIGNIFICANCE H4-IC31® can efficiently boost BCG-primed immunity leading to an increased protective anti-M.tb immune response dominated by IFNγ/TNFα/IL-2 or TNFα/IL2 producing CD4 T cells. H4 in the CD4 T cell inducing adjuvant IC31® is presently in clinical trials.
Collapse
|
60
|
Beamer GL, Cyktor J, Flaherty DK, Stromberg PC, Carruthers B, Turner J. CBA/J mice generate protective immunity to soluble Ag85 but fail to respond efficiently to Ag85 during natural Mycobacterium tuberculosis infection. Eur J Immunol 2012; 42:870-9. [PMID: 22531914 DOI: 10.1002/eji.201142054] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In CBA/J mice, susceptibility to Mycobacterium tuberculosis (M.tb) is associated with low interferon-gamma (IFN-γ) responses to antigens (Antigen 85 (Ag85) and early secreted antigenic target-6 (ESAT-6)) that have been defined as immunodominant. Here, we asked whether the failure of CBA/J mice to recognize Ag85 is a consequence of M.tb infection or whether CBA/J mice have a general defect in generating specific T-cell responses to this protein antigen. We compared CBA/J mice during primary M.tb infection, Ag85 vaccination followed by M.tb challenge, or M.tb memory immune mice for their capacity to generate Ag85-specific IFN-γ responses and to control M.tb infection. CBA/J mice did not respond efficiently to Ag85 in the context of natural infection or re-infection. In contrast, CBA/J mice could generate Ag85-specific IFN-γ responses and protective immunity when this antigen was delivered as a soluble protein. Our data indicate that although M.tb infection of CBA/J mice does not drive an Ag85 response, these mice can fully and protectively respond to Ag85 if it is delivered as a vaccine. The data from this experimental model suggest that the Ag85-containing vaccines in clinical trials should protect M.tb susceptible humans.
Collapse
Affiliation(s)
- Gillian L Beamer
- Center for Microbial Interface Biology, The Ohio State University, Columbus, OH, USA
| | | | | | | | | | | |
Collapse
|
61
|
Esparza-González SC, Troy A, Troudt J, Loera-Arias MJ, Villatoro-Hernández J, Torres-López E, Ancer-Rodríguez J, Gutiérrez-Puente Y, Muñoz-Maldonado G, Saucedo-Cárdenas O, Montes-de-Oca-Luna R, Izzo A. Recombinant adenovirus delivery of calreticulin-ESAT-6 produces an antigen-specific immune response but no protection against a Mycobacterium tuberculosis challenge. Scand J Immunol 2012; 75:259-65. [PMID: 22010821 DOI: 10.1111/j.1365-3083.2011.02655.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Bacillus Calmette-Guerin (BCG) has failed to efficaciously control the worldwide spread of the disease. New vaccine development targets virulence antigens of Mycobacterium tuberculosis that are deleted in Mycobacterium bovis BCG. Immunization with ESAT-6 and CFP10 provides protection against M. tuberculosis in a murine infection model. Further, previous studies have shown that calreticulin increases the cell-mediated immune responses to antigens. Therefore, to test whether calreticulin enhances the immune response against M. tuberculosis antigens, we fused ESAT-6 to calreticulin and constructed a recombinant replication-deficient adenovirus to express the resulting fusion protein (AdCRT-ESAT-6). The adjuvant effect of calreticulin was assayed by measuring cytokine responses specific to ESAT-6. Recombinant adenovirus expressing the fusion protein produced higher levels of interferon-γ and tumour necrosis factor-α in response to ESAT-6. This immune response was not improved by the addition of CFP-10 to the CRT-ESAT-6 fusion protein (AdCRT-ESAT-6-CFP10). Mice immunized with these recombinant adenoviruses did not decrease the mycobacterial burden after low-dose aerosol infection with M. tuberculosis. We conclude that calreticulin can be used as an adjuvant to enhance the immune response against mycobacterial antigens, but it is not enough to protect against tuberculosis.
Collapse
Affiliation(s)
- S C Esparza-González
- Departamento de Histología, Facultad de Medicina, Universidad Autónoma de Nuevo León (UANL), Monterrey N. L., México
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
62
|
Understanding delayed T-cell priming, lung recruitment, and airway luminal T-cell responses in host defense against pulmonary tuberculosis. Clin Dev Immunol 2012; 2012:628293. [PMID: 22545059 PMCID: PMC3321538 DOI: 10.1155/2012/628293] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Accepted: 01/18/2012] [Indexed: 11/18/2022]
Abstract
Mycobacterium tuberculosis (M.tb), the causative bacterium of pulmonary tuberculosis (TB), is a serious global health concern. Central to M.tb effective immune avoidance is its ability to modulate the early innate inflammatory response and prevent the establishment of adaptive T-cell immunity for nearly three weeks. When compared with other intracellular bacterial lung pathogens, such as Legionella pneumophila, or even closely related mycobacterial species such as M. smegmatis, this delay is astonishing. Customarily, the alveolar macrophage (AM) acts as a sentinel, detecting and alerting surrounding cells to the presence of an invader. However, in the case of M.tb, this may be impaired, thus delaying the recruitment of antigen-presenting cells (APCs) to the lung. Upon uptake by APC populations, M.tb is able to subvert and delay the processing of antigen, MHC class II loading, and the priming of effector T cell populations. This delay ultimately results in the deferred recruitment of effector T cells to not only the lung interstitium but also the airway lumen. Therefore, it is of upmost importance to dissect the mechanisms that contribute to the delayed onset of immune responses following M.tb infection. Such knowledge will help design the most effective vaccination strategies against pulmonary TB.
Collapse
|
63
|
Brennan MJ, Clagett B, Fitzgerald H, Chen V, Williams A, Izzo AA, Barker LF. Preclinical evidence for implementing a prime-boost vaccine strategy for tuberculosis. Vaccine 2012; 30:2811-23. [PMID: 22387630 DOI: 10.1016/j.vaccine.2012.02.036] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Revised: 02/07/2012] [Accepted: 02/13/2012] [Indexed: 12/23/2022]
Abstract
In this review, published peer-reviewed preclinical studies using prime-boost tuberculosis (TB) vaccine regimens in animal challenge models for tuberculosis have been evaluated. These studies have been divided into groups that describe prime-boost vaccine combinations that performed better than, equivalent to, or worse than the currently used BCG vaccine. Review of the data has revealed interesting findings, including that more than half of the published studies using BCG as a prime combined with a novel boost vaccine give better efficacy than BCG alone and that the greatest reduction in Mycobacterium tuberculosis (M.tb.) colonization of animal tissues is provided by viral vectored vaccines delivered intranasally. Careful evaluation of these data should assist in defining the value of prime-boost regimens for advancement into human TB vaccine trials and stimulate the development of criteria for choosing which vaccine candidates should be studied further.
Collapse
|
64
|
Luo Y, Jiang W, Da Z, Wang B, Hu L, Zhang Y, An R, Yu H, Sun H, Tang K, Tang Z, Wang Y, Jing T, Zhu B. Subunit Vaccine Candidate AMM Down-Regulated the Regulatory T Cells and Enhanced the Protective Immunity of BCG on a Suitable Schedule. Scand J Immunol 2012; 75:293-300. [DOI: 10.1111/j.1365-3083.2011.02666.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
65
|
Kirenga BJ, Chanda DM, Muwonge CM, Yimer G, Adatu FE, Onyebujoh PC. Advances in the Diagnosis, Treatment and Control of HIV Associated Tuberculosis. Afr J Infect Dis 2012; 6:29-40. [PMID: 23878713 PMCID: PMC3578645 DOI: 10.4314/ajid.v6i2.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
There has been an increase in the number of published tuberculosis/HIV (TB/HIV) research findings in recent times. The potential impact of these findings on routine care has informed this review which aims at discussing current concepts and practices underpinning TB/HIV care and control. Any HIV infected person with a cough of any duration is currently considered a TB suspect. Preliminary results also show that the diagnostic yield of same day sputum samples (front loading) is comparable to two-day samples. Laboratory diagnosis is shifting from Ziehl-Neelsen (ZN) smear microscopy and solid culture to fluorescent microscopy, molecular tests and liquid culture. Concomitant TB/HIV therapy improves survival and WHO has recommended ART for all TB/HIV patients. Unless CD4 cell counts are less than 50 cells/µl, ART can be deferred until end of intensive phase. Evidence of survival benefit at high CD4 cell counts is still lacking. New TB drugs and treatment shortening studies are underway but so far no new TB drugs has been added to the current arsenal and treatment duration still remains six months or more. WHO has recommended the 31s (intensified TB case finding, isoniazid prophylaxis and infection control) for TB/HIV control in addition to effective therapy, Antiretroviral therapy and TB vaccines. There has been immense progress in TB/HIV research, however optimal management of HIV-Infected TB patients, will require further research and appropriate translation of emerging evidence to policy and practice.
Collapse
Affiliation(s)
- Bruce J Kirenga
- Division of Pulmonary Medicine, Mulago National Referral and teaching Hospital /Makerere College of Health Sciences, P.O. Box 7072 Kampala
| | | | | | | | | | | |
Collapse
|
66
|
Abstract
Tuberculosis (TB) disease caused by Mycobacterium tuberculosis (M. tb) remains one of the leading infectious causes of death and disease throughout the world. The only licensed vaccine, Mycobacterium bovis bacille Calmette-Guérin (BCG) confers highly variable protection against pulmonary disease. An effective vaccination regimen would be the most efficient way to control the epidemic. However, BCG does confer consistent and reliable protection against disseminated disease in childhood, and most TB vaccine strategies being developed incorporate BCG to retain this protection. Cellular immunity is necessary for protection against TB and all the new vaccines in development are focused on inducing a strong and durable cellular immune response. There are two main strategies being pursued in TB vaccine development. The first is to replace BCG with an improved whole organism mycobacterial priming vaccine, which is either a recombinant BCG or an attenuated strain of M. tb. The second is to develop a subunit boosting vaccine, which is designed to be administered after BCG vaccination, and to enhance the protective efficacy of BCG. This article reviews the leading candidate vaccines in development and considers the current challenges in the field with regard to efficacy testing.
Collapse
Affiliation(s)
- Helen McShane
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ, UK.
| |
Collapse
|
67
|
Dou J, Wang Y, Yu F, Yang H, Wang J, He X, Xu W, Chen J, Hu K. Protection against Mycobacterium tuberculosis challenge in mice by DNA vaccine Ag85A-ESAT-6-IL-21 priming and BCG boosting. Int J Immunogenet 2011; 39:183-90. [DOI: 10.1111/j.1744-313x.2011.01066.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
68
|
Lin PL, Dietrich J, Tan E, Abalos RM, Burgos J, Bigbee C, Bigbee M, Milk L, Gideon HP, Rodgers M, Cochran C, Guinn KM, Sherman DR, Klein E, Janssen C, Flynn JL, Andersen P. The multistage vaccine H56 boosts the effects of BCG to protect cynomolgus macaques against active tuberculosis and reactivation of latent Mycobacterium tuberculosis infection. J Clin Invest 2011; 122:303-14. [PMID: 22133873 DOI: 10.1172/jci46252] [Citation(s) in RCA: 184] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
It is estimated that one-third of the world's population is infected with Mycobacterium tuberculosis. Infection typically remains latent, but it can reactivate to cause clinical disease. The only vaccine, Mycobacterium bovis bacillus Calmette-Guérin (BCG), is largely ineffective, and ways to enhance its efficacy are being developed. Of note, the candidate booster vaccines currently under clinical development have been designed to improve BCG efficacy but not prevent reactivation of latent infection. Here, we demonstrate that administering a multistage vaccine that we term H56 in the adjuvant IC31 as a boost to vaccination with BCG delays and reduces clinical disease in cynomolgus macaques challenged with M. tuberculosis and prevents reactivation of latent infection. H56 contains Ag85B and ESAT-6, which are two of the M. tuberculosis antigens secreted in the acute phase of infection, and the nutrient stress-induced antigen Rv2660c. Boosting with H56/IC31 resulted in efficient containment of M. tuberculosis infection and reduced rates of clinical disease, as measured by clinical parameters, inflammatory markers, and improved survival of the animals compared with BCG alone. Boosted animals showed reduced pulmonary pathology and extrapulmonary dissemination, and protection correlated with a strong recall response against ESAT-6 and Rv2660c. Importantly, BCG/H56-vaccinated monkeys did not reactivate latent infection after treatment with anti-TNF antibody. Our results indicate that H56/IC31 boosting is able to control late-stage infection with M. tuberculosis and contain latent tuberculosis, providing a rationale for the clinical development of H56.
Collapse
Affiliation(s)
- Philana Ling Lin
- Department of Pediatrics, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
69
|
Tchilian EZ, Ronan EO, de Lara C, Lee LN, Franken KLMC, Vordermeier MH, Ottenhoff THM, Beverley PCL. Simultaneous immunization against tuberculosis. PLoS One 2011; 6:e27477. [PMID: 22110657 PMCID: PMC3217972 DOI: 10.1371/journal.pone.0027477] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Accepted: 10/18/2011] [Indexed: 12/22/2022] Open
Abstract
Background BCG, the only licensed vaccine against tuberculosis, provides some protection against disseminated disease in infants but has little effect on prevention of adult pulmonary disease. Newer parenteral immunization prime boost regimes may provide improved protection in experimental animal models but are unproven in man so that there remains a need for new and improved immunization strategies. Methods and Findings Mice were immunized parenterally, intranasally or simultaneously by both routes with BCG or recombinant mycobacterial antigens plus appropriate adjuvants. They were challenged with Mycobacterium tuberculosis (Mtb) and the kinetics of Mtb growth in the lungs measured. We show that simultaneous immunization (SIM) of mice by the intranasal and parenteral routes is highly effective in increasing protection over parenteral BCG administration alone. Intranasal immunization induces local pulmonary immunity capable of inhibiting the growth of Mtb in the early phase (the first week) of infection, while parenteral immunization has a later effect on Mtb growth. Importantly, these two effects are additive and do not depend on priming and boosting the immune response. The best SIM regimes reduce lung Mtb load by up to 2 logs more than BCG given by either route alone. Conclusions These data establish SIM as a novel and highly effective immunization strategy for Mtb that could be carried out at a single clinic visit. The efficacy of SIM does not depend on priming and boosting an immune response, but SIM is complementary to prime boost strategies and might be combined with them.
Collapse
Affiliation(s)
- Elma Z Tchilian
- The Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom.
| | | | | | | | | | | | | | | |
Collapse
|
70
|
Lin CW, Su IJ, Chang JR, Chen YY, Lu JJ, Dou HY. Recombinant BCG coexpressing Ag85B, CFP10, and interleukin-12 induces multifunctional Th1 and memory T cells in mice. APMIS 2011; 120:72-82. [PMID: 22151310 DOI: 10.1111/j.1600-0463.2011.02815.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mycobacterium tuberculosis (MTB) continues to be a leading cause of human deaths due to an infectious agent. Current efforts are focused on making better TB vaccines. We describe the generation and immunological characterization of recombinant BCG (rBCG). This rBCG was generated by incorporating an expression plasmid encoding two mycobacterial antigens (Ag85B and CFP10) and human interleukin (IL)-12 into a BCG strain. Immunogenicity studies in mice showed that rBCG coexpressing Ag85B, CFP10, and IL-12 (rBCG::Ag85B-CFP10-IL-12) induces a robust immune response in mice. The rBCG vaccine promotes a T-cell response against MTB that is characterized by a high proportion of polyfunctional and memory T cells in spleen and lung. Our results showed strong immunogenicity and mycobacterial growth inhibition of rBCG::Ag85B-CFP10 plus IL-12 than that of BCG vaccine.
Collapse
Affiliation(s)
- Chih-Wei Lin
- Division of Infectious Diseases, National Health Research Institutes, Zhunan, Miaoli, Taiwan
| | | | | | | | | | | |
Collapse
|
71
|
Dey B, Jain R, Gupta UD, Katoch VM, Ramanathan VD, Tyagi AK. A booster vaccine expressing a latency-associated antigen augments BCG induced immunity and confers enhanced protection against tuberculosis. PLoS One 2011; 6:e23360. [PMID: 21858087 PMCID: PMC3157374 DOI: 10.1371/journal.pone.0023360] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Accepted: 07/13/2011] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND In spite of a consistent protection against tuberculosis (TB) in children, Mycobacterium bovis Bacille Calmette-Guerin (BCG) fails to provide adequate protection against the disease in adults as well as against reactivation of latent infections or exogenous reinfections. It has been speculated that failure to generate adequate memory T cell response, elicitation of inadequate immune response against latency-associated antigens and inability to impart long-term immunity against M. tuberculosis infections are some of the key factors responsible for the limited efficiency of BCG in controlling TB. METHODS/PRINCIPAL FINDINGS In this study, we evaluated the ability of a DNA vaccine expressing α-crystallin--a key latency antigen of M. tuberculosis to boost the BCG induced immunity. 'BCG prime-DNA boost' regimen (B/D) confers robust protection in guinea pigs along with a reduced pathology in comparison to BCG vaccination (1.37 log(10) and 1.96 log(10) fewer bacilli in lungs and spleen, respectively; p<0.01). In addition, B/D regimen also confers enhanced protection in mice. Further, we show that B/D immunization in mice results in a heightened frequency of PPD and antigen specific multi-functional CD4 T cells (3(+)) simultaneously producing interferon (IFN)γ, tumor necrosis factor (TNF)α and interleukin (IL)2. CONCLUSIONS/SIGNIFICANCE These results clearly indicate the superiority of α-crystallin based B/D regimen over BCG. Our study, also demonstrates that protection against TB is predictable by an increased frequency of 3(+) Th1 cells with superior effector functions. We anticipate that this study would significantly contribute towards the development of superior booster vaccines for BCG vaccinated individuals. In addition, this regimen can also be expected to reduce the risk of developing active TB due to reactivation of latent infection.
Collapse
Affiliation(s)
- Bappaditya Dey
- Department of Biochemistry, University of Delhi South Campus, New Delhi, India
| | - Ruchi Jain
- Department of Biochemistry, University of Delhi South Campus, New Delhi, India
| | - Umesh D. Gupta
- National JALMA Institute for Leprosy and Other Mycobacterial Diseases, Agra, Uttar Pradesh, India
| | - V. M. Katoch
- National JALMA Institute for Leprosy and Other Mycobacterial Diseases, Agra, Uttar Pradesh, India
| | - V. D. Ramanathan
- Department of Clinical Pathology, Tuberculosis Research Center, Chennai, Tamil Nadu, India
| | - Anil K. Tyagi
- Department of Biochemistry, University of Delhi South Campus, New Delhi, India
- * E-mail:
| |
Collapse
|
72
|
Fact and fiction in tuberculosis vaccine research: 10 years later. THE LANCET. INFECTIOUS DISEASES 2011; 11:633-40. [DOI: 10.1016/s1473-3099(11)70146-3] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
73
|
Sable SB, Cheruvu M, Nandakumar S, Sharma S, Bandyopadhyay K, Kellar KL, Posey JE, Plikaytis BB, Amara RR, Shinnick TM. Cellular immune responses to nine Mycobacterium tuberculosis vaccine candidates following intranasal vaccination. PLoS One 2011; 6:e22718. [PMID: 21799939 PMCID: PMC3143185 DOI: 10.1371/journal.pone.0022718] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2011] [Accepted: 06/29/2011] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND The identification of Mycobacterium tuberculosis vaccines that elicit a protective immune response in the lungs is important for the development of an effective vaccine against tuberculosis. METHODS AND PRINCIPAL FINDINGS In this study, a comparison of intranasal (i.n.) and subcutaneous (s.c.) vaccination with the BCG vaccine demonstrated that a single moderate dose delivered intranasally induced a stronger and sustained M. tuberculosis-specific T-cell response in lung parenchyma and cervical lymph nodes of BALB/c mice than vaccine delivered subcutaneously. Both BCG and a multicomponent subunit vaccine composed of nine M. tuberculosis recombinant proteins induced strong antigen-specific T-cell responses in various local and peripheral immune compartments. Among the nine recombinant proteins evaluated, the alanine proline rich antigen (Apa, Rv1860) was highly antigenic following i.n. BCG and immunogenic after vaccination with a combination of the nine recombinant antigens. The Apa-induced responses included induction of both type 1 and type 2 cytokines in the lungs as evaluated by ELISPOT and a multiplexed microsphere-based cytokine immunoassay. Of importance, i.n. subunit vaccination with Apa imparted significant protection in the lungs and spleen of mice against M. tuberculosis challenge. Despite observed differences in the frequencies and location of specific cytokine secreting T cells both BCG vaccination routes afforded comparable levels of protection in our study. CONCLUSION AND SIGNIFICANCE Overall, our findings support consideration and further evaluation of an intranasally targeted Apa-based vaccine to prevent tuberculosis.
Collapse
Affiliation(s)
- Suraj B Sable
- Division of TB Elimination, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
74
|
Abstract
The current tuberculosis (TB) vaccine, bacille Calmette-Guerin (BCG), is a live vaccine used worldwide, as it protects against severe forms of the disease, saving thousands of lives every year, but its efficacy against pulmonary forms of TB, responsible for transmission of the diseases, is variable. For more than 80 years now no new TB vaccines have been successfully developed. Over the last decade the effort of the scientific community has resulted in the design and construction of promising vaccine candidates. The goal is to develop a new generation of vaccines effective against respiratory forms of the disease. We will focus this review on new prophylactic vaccine candidates that aim to prevent TB diseases. Two are the main strategies used to improve the immunity conferred by the current BCG vaccine, by boosting it with new subunit vaccines, and a second strategy is focused on the construction of new more effective live vaccines, capable to replace the current BCG and to be used as prime vaccines. After rigorous preclinical studies in different animal models new TB vaccine candidates enter in clinical trials in humans. First, a small Phase I for safety followed by immunological evaluation in Phase II trials and finally evaluated in large population Phase III efficacy trials in endemic countries. At present BCG prime and boost with different subunit vaccine candidates are the more advanced assessed in Phase II. Two prime vaccines (based on recombinant BCG) have been successfully evaluated for safety in Phase I trials. A short number of live attenuated vaccines are in advance preclinical studies and the candidates ready to enter Phase I safety trials are produced under current good manufacturing practices.
Collapse
Affiliation(s)
- Carlos Martín Montañés
- Departamento de Microbiología, Facultad de Medicina, Universidad de Zaragoza, CIBER Enfermedades Respiratorias, Zaragoza, Spain.
| | | |
Collapse
|
75
|
[From genetics to genomics in the rational design of new Mycobacterium tuberculosis vaccines]. Enferm Infecc Microbiol Clin 2011; 29:609-14. [PMID: 21684635 DOI: 10.1016/j.eimc.2011.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Revised: 03/30/2011] [Accepted: 04/05/2011] [Indexed: 11/21/2022]
Abstract
Tuberculosis (TB) is an infectious disease affecting people from all ages all over the world. It is estimated that one third of the world population lives infected with the causal agent: Mycobacterium tuberculosis. Despite availability and systematic administration of BCG vaccine in endemic areas, TB transmission remains elusive to control, partly because BGC efficacy has been shown to have wide variability (0-80%). Such variability in protection is attributed to factors including: the BCG strain used for immunization, pre-existing exposure to environmental saprophytic Mycobacterium species, and host genetic factors. In this context, efforts regarding to re-engineering BCG vaccines with the ability to prevent latent TB reactivation, providing long lasting protection, and devoid from collateral effects in immunosuppressed people are urgent. In this work we review the actual molecular «gene-by-gene» strategies aimed at generating BCG alternatives, and discuss the urgent necessity of high throughput technology methods for a rational design for a new TB vaccine.
Collapse
|
76
|
Perry S, Hussain R, Parsonnet J. The impact of mucosal infections on acquisition and progression of tuberculosis. Mucosal Immunol 2011; 4:246-51. [PMID: 21412228 PMCID: PMC5480373 DOI: 10.1038/mi.2011.11] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
More than one-third of the world's population, or over 2 billion people, are infected with Mycobacterium tuberculosis, the causative pathogen of tuberculosis in humans. Why only 10% of those infected develop active disease while the remainder harbor latent infection remains one of the greatest scientific and public health mysteries. Bacterial persistence is characterized by a dynamic state of immunological tolerance between pathogen and host. The critical role of CD4(+) T cells in defense against intracellular pathogens became evident during epidemiological studies of HIV-1 infection, which showed a clear inverse relationship between CD4(+) T-cell count in peripheral blood and increased risk of infection with M. tuberculosis, pneumocystis and Toxoplasma gondii. There is also growing evidence of a common mucosal immune system, whereby immune cells activated at one mucosal site may disseminate to remote effector sites. In this commentary, we review emerging evidence from human studies that the outcome of M. tuberculosis infection is influenced by concurrent mucosal infections, using Helicobacter pylori and geohelminths as examples. Understanding how the complexity of microbial exposures influences host immunity may have important implications for vaccine development and therapeutic interventions.
Collapse
Affiliation(s)
- S Perry
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA, USA
| | - R Hussain
- Department of Molecular Biology, Aga Khan University, Karachi, Pakistan
| | - J Parsonnet
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA, USA
| |
Collapse
|
77
|
The M. tuberculosis phosphate-binding lipoproteins PstS1 and PstS3 induce Th1 and Th17 responses that are not associated with protection against M. tuberculosis infection. Clin Dev Immunol 2011; 2011:690328. [PMID: 21603219 PMCID: PMC3095447 DOI: 10.1155/2011/690328] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Accepted: 02/10/2011] [Indexed: 12/04/2022]
Abstract
The M. tuberculosis phosphate-binding transporter lipoproteins PstS1 and PstS3 were good immunogens inducing CD8+ T-cell activation and both Th1 and Th17 immunity in mice. However, this antigen-specific immunity, even when amplified by administration of the protein with the adjuvant LTK63 or by the DNA priming/protein boosting regimen, was not able to contain M. tuberculosis replication in the lungs of infected mice. The lack of protection might be ascribed with the scarce/absent capacity of PstS1/PstS3 antigens to modulate the IFN-γ response elicited by M. tuberculosis infection during which, however, PstS1-specific IL-17 secreting cells were generated in both unvaccinated and BCG-vaccinated mice. In spite of a lack of protection by PstS1/PstS3 immunizations, our results do show that PstS1 is able to induce IL-17 response upon M. tuberculosis infection which is of interest in the study of anti-M. tuberculosis immunity and as potential immunomodulator in combined vaccines.
Collapse
|
78
|
Abstract
Tuberculosis in infants and young children remains an all too common cause of morbidity and mortality in high burden countries, despite the fact that the majority of these children receive vaccination with BCG in infancy. BCG confers incomplete and variable protection against pulmonary tuberculosis [PTB] and is unsafe in HIV positive persons. Newer TB vaccines, which, it is hoped, will either replace or complement BCG are being developed and a number of these have reached the stage of clinical trials, with two booster vaccines going into Phase IIB trials in 2009. Prospects for at least one new licensed TB vaccine within the next 5-10 years appear reasonable. This article explores some of the issues around the development of new vaccines against TB and details the leading candidates.
Collapse
Affiliation(s)
- Tony Hawkridge
- Aeras Global TB Vaccine Foundation, Africa Office, Belmont Square, Belmont Road, Rondebosch, Cape Town, 7700, South Africa.
| | | |
Collapse
|
79
|
Immunogenicity and protective efficacy against murine tuberculosis of a prime-boost regimen with BCG and a DNA vaccine expressing ESAT-6 and Ag85A fusion protein. Clin Dev Immunol 2011; 2011:617892. [PMID: 21461375 PMCID: PMC3065234 DOI: 10.1155/2011/617892] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2010] [Accepted: 12/30/2010] [Indexed: 11/17/2022]
Abstract
Heterologous prime-boost regimens utilizing BCG as a prime vaccine probably represent the best hope for the development of novel tuberculosis (TB) vaccines. In this study, we examined the immunogenicity and protective efficacy of DNA vaccine (pcD685A) expressing the fusion protein of Ag85A and ESAT-6 (r685A) and its booster effects in BCG-immunized mice. The recombinant r685A fusion protein stimulated higher level of antigen-specific IFN-γ release in tuberculin skin test- (TST-) positive healthy household contacts of active pulmonary TB patients than that in TST-negative population. Vaccination of C57BL/6 mice with pcD685A resulted in significant protection against challenge with virulent Mycobacterium tuberculosis H37Rv when compared with the control group. Most importantly, pcD685A could act as a BCG booster and amplify Th1-type cell-mediated immunity in the lung of BCG-vaccinated mice as shown the increased expression of IFN-γ. The most significant reduction in bacterial load of both spleen and lung was obtained in mice vaccinated with BCG prime and pcD685A DNA booster when compared with BCG or pcD685A alone. Thus, our study indicates that pcD685A may be an efficient booster vaccine against TB with a strong ability to enhance prior BCG immunity.
Collapse
|
80
|
Zhang H, Wen K, Shen J, Geng S, Huang J, Pan Z, Jiao X. Characterization of immune responses following intranasal immunization with the Mycobacterium bovis CFP-10 protein expressed by attenuated Salmonella typhimurium. Scand J Immunol 2010; 72:277-83. [PMID: 20883312 DOI: 10.1111/j.1365-3083.2010.02421.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Culture filtrate protein 10 (CFP-10) from Mycobacterium bovis or Mycobacterium tuberculosis (MTB) is an immunodominant T-cell antigen expressed during the early stages of infection. Because lungs are most commonly associated with primary M. bovis infections, specific immunity at this site is desirable for protection. Therefore, in this study, immune responses generated in mouse lung, spleen and Peyer's patches were examined following intranasal (i.n.) immunization with Salmonella typhimurium- expressing CFP-10. Cells harvested from the lungs and Peyer's patches of immunized mice and then stimulated with CFP-10 produced significant levels of IFN-γ and these mice developed elevated serum IgG and lung IgA anti-CFP-10 responses, suggesting that this approach induced potent anti-CFP-10 mucosal immunity. Our study demonstrates that i.n. administration of CFP-10 expressed by S. typhimurium represents an effective way to induce efficient immune response to M. bovis antigen.
Collapse
Affiliation(s)
- H Zhang
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu, China
| | | | | | | | | | | | | |
Collapse
|
81
|
Abstract
Given that TB still constitutes a tremendous public health problem at the start of the 21st Century, it may come as a surprise that Bacillus Calmette-Guérin (BCG), developed nearly 100 years ago, is today still the only vaccine available against TB. Owing to its limited efficiency in controlling TB, much effort has been deployed to develop new, improved vaccines, with initial preclinical models showing encouraging results. However, since most individuals worldwide have been vaccinated with BCG, new vaccine developments have to be placed in that context. Consequently, several approaches explore the heterologous prime-boost strategy. In this strategy, BCG-primed immunity will be strengthened or prolonged by the administration of antigens present in BCG but formulated in a different manner; either as purified antigens in the presence of appropriate adjuvants, as DNA vaccines or as viral-encoded mycobacterial antigens.
Collapse
|
82
|
Hall LJ, Clare S, Dougan G. Probing local innate immune responses after mucosal immunisation. JOURNAL OF IMMUNE BASED THERAPIES AND VACCINES 2010; 8:5. [PMID: 20836885 PMCID: PMC2945349 DOI: 10.1186/1476-8518-8-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Accepted: 09/13/2010] [Indexed: 11/10/2022]
Abstract
Background Intranasal immunisation is potentially a very effective route for inducing both mucosal and systemic immunity to an infectious agent. Methods Balb/c mice were intranasally immunised with the mucosal adjuvant heat labile toxin and the Mycobacterium tuberculosis fusion protein Ag85B-ESAT6 and early changes in innate immune responses within local mucosal tissues were examined using flow cytometry and confocal microscopy. Antigen-specific humoral and cellular immune responses were also evaluated. Results Intranasal immunisation induced significant changes in both number and distribution of dendritic cells, macrophages and neutrophils within the nasal-associated lymphoid tissue and cervical lymph nodes in comparison to controls as early as 5 h post immunisation. Immunisation also resulted in a rapid and transient increase in activation marker expression first in the nasal-associated lymphoid tissue, and then in the cervical lymph nodes. This heightened activation status was also apparent from the pro-inflammatory cytokine profiles of these innate populations. In addition we also showed increased expression and distribution of a number of different cell adhesion molecules early after intranasal immunisation within these lymphoid tissues. These observed early changes correlated with the induction of a TH1 type immune response. Conclusions These data provide insights into the complex nature of innate immune responses induced following intranasal immunisation within the upper respiratory tract, and may help clarify the concepts and provide the tools that are needed to exploit the full potential of mucosal vaccines.
Collapse
Affiliation(s)
- Lindsay J Hall
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK.
| | | | | |
Collapse
|
83
|
Salyaev RK, Rigano MM, Rekoslavskaya NI. Development of plant-based mucosal vaccines against widespread infectious diseases. Expert Rev Vaccines 2010; 9:937-46. [PMID: 20673015 DOI: 10.1586/erv.10.81] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Mucosal vaccination is a perspective for the control of infectious diseases, since it is capable of inducing humoral and cell-mediated responses. In addition, the delivery of vaccines to mucosal surfaces makes immunization practice safe and acceptable, and eliminates needle-associated risks. Transgenic plants can be used as bioreactors for the production of mucosally delivered protective antigens. This technology shows great promise to simplify and decrease the cost of vaccine delivery. Herein, we review the development of mucosally administered vaccines expressed in transgenic plants. In particular, we evaluate the advantages and disadvantages of using plants for the production of mucosal vaccines against widespread infectious diseases such as HIV, hepatitis B and TB.
Collapse
Affiliation(s)
- Rurick K Salyaev
- Siberian Institute of Plant Physiology and Biochemistry of The Siberian Branch of the RAS, Irkutsk, Russia.
| | | | | |
Collapse
|
84
|
Abstract
There has never been a greater need for a new protective tuberculosis vaccine. Bacille Calmette-Guerin remains the cornerstone of any vaccine strategy, but improving its immunogenicity and efficacy has now become an urgent global health priority. This review discusses the main vaccines currently in clinical development and other novel vaccine strategies in the pipeline. It addresses the key questions in vaccine design, including antigen selection, route of vaccine delivery and immune correlates of vaccine-induced protection. There is an opportunity to identify such correlates from ongoing and future Phase II/III trials and, as these emerge, they can be used to validate the most relevant and predictive animal models with which to develop the next generation of new vaccines.
Collapse
Affiliation(s)
- Angela M Minassian
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Level 2, Roosevelt Drive, Headington, Oxford OX3 7DQ, UK.
| | | |
Collapse
|
85
|
Abstract
New vaccines are urgently needed if we want to reach the goal of substantially reducing the incidence of tuberculosis by 2050. Despite a steady increase in funding over the past decade, there is still a striking financial shortfall for vaccine research and development for tuberculosis. Yet, around ten vaccine candidates have left the laboratory stage and entered clinical trials. These vaccines are either aimed at replacing the present vaccine, BCG, or at enhancing immunity induced by BCG. However, these pre-exposure candidates are designed for prevention of disease and will therefore neither eradicate the pathogen, nor prevent stable infection. Long-term vaccination strategies need to target these more ambitious goals. Even though vaccine development will have a price, the return of investment will greatly exceed original costs.
Collapse
Affiliation(s)
- Stefan H E Kaufmann
- Department of Immunology, Max Planck Institute for Infection Biology, Berlin, Germany.
| | | | | |
Collapse
|
86
|
Airway luminal T cells: a newcomer on the stage of TB vaccination strategies. Trends Immunol 2010; 31:247-52. [PMID: 20542470 DOI: 10.1016/j.it.2010.05.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2010] [Revised: 04/26/2010] [Accepted: 05/03/2010] [Indexed: 01/25/2023]
Abstract
Protection against pulmonary tuberculosis (TB) by vaccination is often ascribed to the presence of TB-reactive T cells in the lung before infection. Challenging this view, new studies analyzing vaccine-induced T cells in various tissue compartments after parenteral immunization suggest a poor correlation between the presence of anti-TB T cells in the lung interstitium and spleen before Mycobacterium tuberculosis exposure and protection. In contrast, respiratory mucosal immunization leads to distribution of T cells not only in the lung interstitium and spleen, but also in the airway lumen, and the presence of these cells correlates well with protection. Furthermore, airway luminal recruitment of parenteral vaccine-induced T cells in peripheral tissues prior to M. tuberculosis challenge restores protection. We propose that understanding the biology of airway luminal T cells holds important implications for developing effective TB vaccination strategies.
Collapse
|
87
|
Palma C, Vendetti S, Cassone A. Role of 4-1BB receptor in the control played by CD8(+) T cells on IFN-gamma production by Mycobacterium tuberculosis antigen-specific CD4(+) T Cells. PLoS One 2010; 5:e11019. [PMID: 20544034 PMCID: PMC2882340 DOI: 10.1371/journal.pone.0011019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Accepted: 05/10/2010] [Indexed: 11/21/2022] Open
Abstract
Background Antigen-specific IFN-γ producing CD4+ T cells are the main mediators of protection against Mycobacterium tuberculosis infection both under natural conditions and following vaccination. However these cells are responsible for lung damage and poor vaccine efficacy when not tightly controlled. Discovering new tools to control nonprotective antigen-specific IFN-γ production without affecting protective IFN-γ is a challenge in tuberculosis research. Methods and Findings Immunization with DNA encoding Ag85B, a candidate vaccine antigen of Mycobacterium tuberculosis, elicited in mice a low but protective CD4+ T cell-mediated IFN-γ response, while in mice primed with DNA and boosted with Ag85B protein a massive increase in IFN-γ response was associated with loss of protection. Both protective and non-protective Ag85B-immunization generated antigen-specific CD8+ T cells which suppressed IFN-γ-secreting CD4+ T cells. However, ex vivo ligation of 4-1BB, a member of TNF-receptor super-family, reduced the massive, non-protective IFN-γ responses by CD4+ T cells in protein-boosted mice without affecting the low protective IFN-γ-secretion in mice immunized with DNA. This selective inhibition was due to the induction of 4-1BB exclusively on CD8+ T cells of DNA-primed and protein-boosted mice following Ag85B protein stimulation. The 4-1BB-mediated IFN-γ inhibition did not require soluble IL-10, TGF-β, XCL-1 and MIP-1β. In vivo Ag85B stimulation induced 4-1BB expression on CD8+ T cells and in vivo 4-1BB ligation reduced the activation, IFN-γ production and expansion of Ag85B-specific CD4+ T cells of DNA-primed and protein-boosted mice. Conclusion/Significance Antigen-specific suppressor CD8+ T cells are elicited through immunization with the mycobacterial antigen Ag85B. Ligation of 4-1BB receptor further enhanced their suppressive activity on IFN-γ-secreting CD4+ T cells. The selective expression of 4-1BB only on CD8+ T cells in mice developing a massive, non-protective IFN-γ response opens novel strategies for intervention in tuberculosis pathology and vaccination through T-cell co-stimulatory-based molecular targeting.
Collapse
Affiliation(s)
- Carla Palma
- Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Rome, Italy.
| | | | | |
Collapse
|
88
|
Franco LH, Paula MOE, Wowk PF, Fonseca DMD, Sérgio CA, Fedatto PF, Gembre AF, Ramos SG, Silva CL, Medeiros AI, Faccioli LH, Bonato VLD. Leukotrienes are not essential for the efficacy of a heterologous vaccine against Mycobacterium tuberculosis infection. Braz J Med Biol Res 2010; 43:645-50. [PMID: 20521013 DOI: 10.1590/s0100-879x2010007500053] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Accepted: 05/24/2010] [Indexed: 12/22/2022] Open
Abstract
Leukotrienes are reported to be potent proinflammatory mediators that play a role in the development of several inflammatory diseases such as asthma, rheumatoid arthritis and periodontal disease. Leukotrienes have also been associated with protection against infectious diseases. However, the role of leukotrienes in Mycobacterium tuberculosis infection is not understood. To answer this question, we studied the role of leukotrienes in the protective immune response conferred by prime-boost heterologous immunization against tuberculosis. We immunized BALB/c mice (4-11/group) with subcutaneous BCG vaccine (1 x 10(5) M. bovis BCG) (prime) followed by intramuscular DNA-HSP65 vaccine (100 microg) (boost). During the 30 days following the challenge, the animals were treated by gavage daily with MK-886 (5 mg x kg(-1) x day(-1)) to inhibit leukotriene synthesis. We showed that MK-886-treated mice were more susceptible to M. tuberculosis infection by counting the number of M. tuberculosis colony-forming units in lungs. The histopathological analysis showed an impaired influx of leukocytes to the lungs of MK-886-treated mice after infection, confirming the involvement of leukotrienes in the protective immune response against experimental tuberculosis. However, prime-boost-immunized mice treated with MK-886 remained protected after challenge with M. tuberculosis, suggesting that leukotrienes are not required for the protective effect elicited by immunization. Protection against M. tuberculosis challenge achieved by prime-boost immunization in the absence of leukotrienes was accompanied by an increase in IL-17 production in the lungs of these animals, as measured by ELISA. Therefore, these data suggest that the production of IL-17 in MK-886-treated, immunized mice could contribute to the generation of a protective immune response after infection with M. tuberculosis.
Collapse
Affiliation(s)
- L H Franco
- Núcleo de Pesquisas em Tuberculose, Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
89
|
Ohol YM, Goetz DH, Chan K, Shiloh MU, Craik CS, Cox JS. Mycobacterium tuberculosis MycP1 protease plays a dual role in regulation of ESX-1 secretion and virulence. Cell Host Microbe 2010; 7:210-20. [PMID: 20227664 DOI: 10.1016/j.chom.2010.02.006] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Revised: 12/05/2009] [Accepted: 02/09/2010] [Indexed: 11/19/2022]
Abstract
Mycobacterium tuberculosis uses the ESX-1 secretion system to deliver virulence proteins during infection of host cells. Here we report a mechanism of posttranscriptional control of ESX-1 mediated by MycP1, a M. tuberculosis serine protease. We show that MycP1 is required for ESX-1 secretion but that, unexpectedly, genetic inactivation of MycP1 protease activity increases secretion of ESX-1 substrates. We demonstrate that EspB, an ESX-1 substrate required for secretion, is a target of MycP1 in vitro and in vivo. During macrophage infection, an inactive MycP1 protease mutant causes hyperactivation of ESX-1-stimulated innate signaling pathways. MycP1 is required for growth in mice during acute infection, while loss of its protease activity leads to attenuated virulence during chronic infection. As the key ESX-1 substrates ESAT-6 and CFP-10 are highly immunogenic, fine-tuning of their secretion by MycP1 may balance virulence and immune detection and be essential for successful maintenance of long-term M. tuberculosis infection.
Collapse
Affiliation(s)
- Yamini M Ohol
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | | | | | | | | | | |
Collapse
|
90
|
Hall LJ, Clare S, Dougan G. NK cells influence both innate and adaptive immune responses after mucosal immunization with antigen and mucosal adjuvant. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2010; 184:4327-37. [PMID: 20220095 PMCID: PMC3517975 DOI: 10.4049/jimmunol.0903357] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
NK cells were found to be recruited in a temporally controlled manner to the nasal-associated lymphoid tissue and the cervical lymph nodes of mice after intranasal immunization with Ag85B-early secreted antigenic target 6 kDa from Mycobacterium tuberculosis mixed with Escherichia coli heat-labile toxin as adjuvant. These NK cells were activated and secreted a diverse range of cytokines and other immunomodulators. Using Ab depletion targeting anti-asialo GM1, we found evidence for altered trafficking, impaired activation, and cytokine secretion of dendritic cells, macrophages, and neutrophils in immunized NK cell-depleted mice compared with control animals. Analysis of Ag-specific immune responses revealed an attenuated Ab and cytokine response in immunized NK cell-depleted animals. Systemic administration of rIL-6 but not rIFN-gamma significantly restored immune responses in mice depleted of NK cells. In conclusion, cytokine production, particularly IL-6, via NK cells and NK cell-activated immune populations plays an important role in the establishment of local innate immune responses and the consequent development of adaptive immunity after mucosal immunization.
Collapse
Affiliation(s)
- Lindsay J Hall
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, United Kingdom.
| | | | | |
Collapse
|
91
|
Abstract
The current tuberculosis (TB) vaccine bacillus Calmette-Guérin (BCG) fails to protect against adult pulmonary TB. Yet, its capacity to control miliary TB in newborn infants forms the basis for development of novel vaccine candidates. These either exploit genetic modification of BCG to create a viable replacement vaccine or use BCG to prime the immune response followed by boost with a novel subunit vaccine. This could ultimately result in a combination vaccination schedule comprising a prime with a live BCG replacement followed by a subunit vaccine boost. Ultimately, vaccination strategies that achieve sterile eradication of, or prevent infection with, tubercle bacilli would be an ambitious highly promising goal.
Collapse
Affiliation(s)
- S H E Kaufmann
- Department of Immunology, Max Planck Institute for Infection Biology, Berlin, Germany.
| |
Collapse
|
92
|
Speranza V, Colone A, Cicconi R, Palmieri G, Giovannini D, Grassi M, Mattei M, Sali M, Delogu G, Andreola F, Colizzi V, Mariani F. Recombinant BCG-Rv1767 amount determines, in vivo, antigen-specific T cells location, frequency, and protective outcome. Microb Pathog 2010; 48:150-9. [PMID: 20219669 DOI: 10.1016/j.micpath.2010.02.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2009] [Accepted: 02/18/2010] [Indexed: 02/04/2023]
Abstract
One possibility to improve the efficacy of BCG vaccine against TB is to create a recombinant BCG (r-BCG), increasing the expression of mycobacterial antigens, to ameliorate the response to BCG. Here we describe a new r-BCG expressing the gene Rv1767, induced by Mycobacterium tuberculosis during its survival in human macrophages. The r-BCG elicited a specific T cells response in Balb/c mice higher than wt BCG. The r-BCG amount used to immunise mice determined diverse Th1/Th2 equilibriums, which was not the same in spleen and Lymph Nodes. Differences in cytokines production were found for IL-10, IL-4, TNF-alpha, and Arginase-1, which, in some conditions, resulted higher in r-BCG as compared to wt BCG-immunised mice. The immunisation with r-BCG-Rv1767 induced a lesser protective activity than wt BCG in a mouse model of TB. This reduction might likely be explained by the specific T cells phenotype and setting existing before MTB challenge, induced by either the single or the triple dose of r-BCG. The use of this model may help to highlight the capacity of different M. tuberculosis antigens to induce a protective immune response, actually not necessarily embodied by an increased frequency of Antigen-specific effector memory T cells.
Collapse
Affiliation(s)
- Viviana Speranza
- Institute of Neurobiology and Molecular Medicine, National Research Council, Via del Fosso del Cavaliere 100, 00133 Rome, Italy
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
93
|
Chen L, Xu M, Wang ZY, Chen BW, Du WX, Su C, Shen XB, Zhao AH, Dong N, Wang YJ, Wang GZ. The development and preliminary evaluation of a new Mycobacterium tuberculosis vaccine comprising Ag85b, HspX and CFP-10:ESAT-6 fusion protein with CpG DNA and aluminum hydroxide adjuvants. ACTA ACUST UNITED AC 2010; 59:42-52. [PMID: 20298499 DOI: 10.1111/j.1574-695x.2010.00660.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ag85b and HspX of Mycobacterium tuberculosis (Mtb) (H37Rv) were expressed and purified in this study. These two proteins were combined with another fusion protein CFP-10:ESAT-6 (C/E) (Ag), then mixed with the adjuvants CpG DNA and aluminum hydroxide and used to vaccinate mice and guinea pigs challenged with Mtb (H37Rv). The number of spleen lymphocytes secreting Ag85b, HspX and C/E-specific interferon-gamma were significantly higher in the Ag+Al+CpG group than in the Ag and CpG groups. The combination of Ag, Al and CpG induced the highest concentrations of anti-Ag85b, anti-HspX and anti-C/E immunoglobulin G in mouse serum. Mouse peritoneal macrophages from the Ag+Al+CpG group secreted significantly higher levels of interleukin-12 compared with macrophages from the other groups. The total mean liver, lung and spleen lesion scores and bacterial loads in the spleen in guinea pigs vaccinated with Ag+Al+CpG were lower than those of the other groups, but no significant difference was found. These results show that the mixture of Ag85b, HspX and C/E with a combination of CpG and aluminum adjuvants can induce both humoral and cellular immune responses in mice, whereas it plays only a small role in the control of disease progression in guinea pigs challenged with Mtb.
Collapse
Affiliation(s)
- Lei Chen
- School of Public Health, Shandong University, Ji'nan, China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
94
|
Singhal N, Bisht D, Joshi B. Immunoprophylaxis of tuberculosis: an update of emerging trends. Arch Immunol Ther Exp (Warsz) 2010; 58:97-106. [PMID: 20140756 DOI: 10.1007/s00005-010-0068-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Accepted: 07/06/2009] [Indexed: 11/25/2022]
Abstract
Developing effective prophylactics to combat tuberculosis is currently in an exploratory stage. The HIV pandemic and emergence of multi- and extensively drug-resistant strains of Mycobacterium tuberculosis indicate that the current preventive measures against this ever-evolving pathogen are inadequate. The currently available vaccine BCG in its present form affords variable protection which usually wanes with aging. Various reasons have been cited to explain the discrepancies in the efficacy of BCG, including generic differences in the different BCG vaccine strains used in immunization program throughout the world. The low efficacy of BCG vaccine has promoted the search for novel vaccines for tuberculosis. The search strategies aim at completely replacing the existing vaccine and/or augmenting/improving the current BCG vaccine. Among new vaccine candidates are live attenuated M. tuberculosis vaccines, recombinant BCG, DNA vaccines, subunit vaccine, and fusion protein-based vaccines. More than 200 new vaccine candidates have been developed as a result of research work over the past few years. To date, at least eight vaccine candidates are undergoing clinical evaluation, with a few of them successfully qualifying in the first phase of clinical testing. These recent advances present an optimistic insight whereby a new tuberculosis vaccine might be expected to be available for public use in the next few years.
Collapse
Affiliation(s)
- Neelja Singhal
- Department of Biochemistry, National JALMA Institute for Leprosy and Other Mycobacterial Diseases, Indian Council of Medical Research, Tajganj, Agra 282001, India
| | | | | |
Collapse
|
95
|
Xing Z. Importance of T-cell location rekindled: implication for tuberculosis vaccination strategies. Expert Rev Vaccines 2010; 8:1465-8. [PMID: 19863237 DOI: 10.1586/erv.09.110] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
|
96
|
Verma I, Grover A. Antituberculous vaccine development: a perspective for the endemic world. Expert Rev Vaccines 2010; 8:1547-53. [PMID: 19863247 DOI: 10.1586/erv.09.111] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Several new antituberculous vaccine candidates that are effective against primary infection in preclinical animal models have now entered the early phases of clinical trials. Many of these clinical trials involve subunit vaccines, recombinant bacillus Calmette-Guérin (BCG), or improvement of BCG immunity by boosting with subunit vaccines or recombinant viral vectors expressing immunodominant TB antigens. The burning question at this stage is: will the current vaccines be effective in the endemic world where the diverse and complex challenges of TB exist? These challenges include protection of those individuals who are already vaccinated with BCG, those already exposed to environmental mycobacteria and those infected with latent TB or HIV. This review focuses on the available BCG vaccine, new TB vaccines in the pipeline and what type of vaccines are actually needed in high-burden endemic countries.
Collapse
Affiliation(s)
- Indu Verma
- Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
| | | |
Collapse
|
97
|
Abstract
Mucosal vaccination offers the advantage of blocking pathogens at the portal of entry, improving patient's compliance, facilitating vaccine delivery, and decreasing the risk of unwanted spread of infectious agents via contaminated syringes.Recent advances in vaccinology have created an array of vaccine constructs that can be delivered to mucosal surfaces of the respiratory, gastrointestinal, and genitourinary tracts using intranasal, oral, and vaginal routes. Due to the different characteristics of mucosal immune response, as compared with systemic response, mucosal immunization requires particular methods of antigen presentation. Well-tolerated adjuvants that enhance the efficacy of such vaccines will play an important role in mucosal immunization. Among promising mucosal adjuvants, mutants of cholera toxin and the closely related heat-labile enterotoxin (LT) of enterotoxigenic Escherichia coli present powerful tools, augmenting the local and systemic serum antibody response to co-administered antigens.In this chapter, we describe the formulation and application of vaccines using the genetically modified LTK63 mutant as a prototype of the family of these mucosal adjuvants and the tools to determine its activity in the mouse model.
Collapse
|
98
|
Shanahan ER, Pinto R, Triccas JA, Britton WJ, West NP. Cutinase-like protein-6 of Mycobacterium tuberculosis is recognised in tuberculosis patients and protects mice against pulmonary infection as a single and fusion protein vaccine. Vaccine 2009; 28:1341-6. [PMID: 19941992 DOI: 10.1016/j.vaccine.2009.11.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Revised: 09/28/2009] [Accepted: 11/05/2009] [Indexed: 10/20/2022]
Abstract
Infection with Mycobacterium tuberculosis continues to be a leading cause of death in many regions of the world, and control of this disease is hampered by the lack of a safe and effective vaccine. Secreted proteins of M. tuberculosis are an important group of antigens for subunit vaccines which target this infection. We have tested three secreted members of the cutinase-like protein (CULP) family of M. tuberculosis for their potential as protein vaccine antigens. Culp6 elicited a strong T lymphocyte response in M. tuberculosis infected mice, and importantly, in tuberculosis (TB) patients tested. Culp1, Culp2 and Culp6 when delivered as protein vaccines to mice, induced potent IFN-gamma responses which in turn translated into a significant level of protection against aerosol M. tuberculosis infection. A Culp1-6 fusion protein provided an increased level of protection against infection compared to Culp1 or Culp6 alone. The data presented here may indicate that the cell wall-associated, putatively essential protein Culp6, shown here for the first time to be recognised in TB patients, is an attractive candidate for inclusion in future subunit vaccines.
Collapse
Affiliation(s)
- Erin R Shanahan
- Mycobacterial Research Program, Centenary Institute, New South Wales, Australia
| | | | | | | | | |
Collapse
|
99
|
Non-clinical efficacy and safety of HyVac4:IC31 vaccine administered in a BCG prime-boost regimen. Vaccine 2009; 28:1084-93. [PMID: 19896449 DOI: 10.1016/j.vaccine.2009.10.114] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2009] [Revised: 10/08/2009] [Accepted: 10/19/2009] [Indexed: 11/21/2022]
Abstract
Despite the extensive success with the introduction of M. bovis Bacille Calmette-Guérin (BCG), tuberculosis (TB) remains a major global epidemic infecting between 8 and 9 million people annually with an estimated 1.7 million deaths each year. However, because of its demonstrated effectiveness against some of the most severe forms of childhood TB, it is now realized that BCG vaccination of newborns is unlikely to be replaced. Therefore, BCG or an improved BCG will continue to be used as a prime TB vaccine and there is a need to develop effective boost vaccines that would enhance and prolong the protective immunity induced by BCG prime immunization. We report on a heterologous booster approach using two highly immunogenic TB antigens comprising Ag85B and TB10.4 (HyVac4) delivered as a fusion molecule and formulated in the proprietary adjuvant IC31. This vaccine was found to be immunogenic and demonstrated greater protection in the more stringent guinea pig model of pulmonary tuberculosis than BCG alone when used in a prime/boost regimen. Significant difference in lung involvement was observed for all animals in the HyVac4 boosted group compared to BCG alone regardless of time to death or sacrifice. A vaccine toxicology study of the HyVac4:IC31 regimen was performed and it was judged safe to advance the vaccine into clinical trials. Therefore, all non-clinical data supports the suitability of HyVac4 as a safe, immunogenic, and effective vaccination in a prime-boost regimen with BCG.
Collapse
|
100
|
Dey B, Jain R, Khera A, Rao V, Dhar N, Gupta UD, Katoch VM, Ramanathan VD, Tyagi AK. Boosting with a DNA vaccine expressing ESAT-6 (DNAE6) obliterates the protection imparted by recombinant BCG (rBCGE6) against aerosol Mycobacterium tuberculosis infection in guinea pigs. Vaccine 2009; 28:63-70. [PMID: 19835824 DOI: 10.1016/j.vaccine.2009.09.121] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Accepted: 09/25/2009] [Indexed: 12/12/2022]
Abstract
Owing to its highly immunodominant nature and ability to induce long-lived memory immunity, ESAT-6, a prominent antigen of Mycobacterium tuberculosis, has been employed in several approaches to develop tuberculosis vaccines. Here, for the first time, we combined ESAT-6 based recombinant BCG (rBCG) and DNA vaccine (DNAE6) in a prime boost approach. Interestingly, in spite of inducing an enhanced antigen specific IFN-gamma response in mice, a DNAE6 booster completely obliterated the protection imparted by rBCG against tuberculosis in guinea pigs. Analysis of immunopathology and cytokine responses suggests involvement of an exaggerated immunity behind the lack of protection imparted by this regimen.
Collapse
Affiliation(s)
- Bappaditya Dey
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India
| | | | | | | | | | | | | | | | | |
Collapse
|