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Abstract
Mucosal surfaces are the interface between the host’s internal milieu and the external environment, and they have dual functions, serving as physical barriers to foreign antigens and as accepting sites for vital materials. Mucosal vaccines are more favored to prevent mucosal infections from the portal of entry. Although mucosal vaccination has many advantages, licensed mucosal vaccines are scarce. The most widely studied mucosal routes are oral and intranasal. Licensed oral and intranasal vaccines are composed mostly of whole cell killed or live attenuated microorganisms serving as both delivery systems and built-in adjuvants. Future mucosal vaccines should be made with more purified antigen components, which will be relatively less immunogenic. To induce robust protective immune responses against well-purified vaccine antigens, an effective mucosal delivery system is an essential requisite. Recent developments in biomaterials and nanotechnology have enabled many innovative mucosal vaccine trials. For oral vaccination, the vaccine delivery system should be able to stably carry antigens and adjuvants and resist harsh physicochemical conditions in the stomach and intestinal tract. Besides many nano/microcarrier tools generated by using natural and chemical materials, the development of oral vaccine delivery systems using food materials should be more robustly researched to expand vaccine coverage of gastrointestinal infections in developing countries. For intranasal vaccination, the vaccine delivery system should survive the very active mucociliary clearance mechanisms and prove safety because of the anatomical location of nasal cavity separated by a thin barrier. Future mucosal vaccine carriers, regardless of administration routes, should have certain common characteristics. They should maintain stability in given environments, be mucoadhesive, and have the ability to target specific tissues and cells.
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Lesellier S, Boschiroli ML, Barrat J, Wanke C, Salguero FJ, Garcia-Jimenez WL, Nunez A, Godinho A, Spiropoulos J, Palmer S, Dave D, Anderson P, Boucher JM, de Cruz K, Henault S, Michelet L, Gowtage S, Williams GA, Nadian AK, Monchâtre-Leroy E, Boué F, Chambers MA, Richomme C. Detection of live M. bovis BCG in tissues and IFN-γ responses in European badgers (Meles meles) vaccinated by oropharyngeal instillation or directly in the ileum. BMC Vet Res 2019; 15:445. [PMID: 31810466 PMCID: PMC6898942 DOI: 10.1186/s12917-019-2166-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 11/06/2019] [Indexed: 12/15/2022] Open
Abstract
Background Oral vaccination with Mycobacterium bovis Bacille of Calmette and Guerin (BCG) has provided protection against M. bovis to badgers both experimentally and in the field. There is also evidence suggesting that the persistence of live BCG within the host is important for maintaining protection against TB. Here we investigated the capacity of badger inductive mucosal sites to absorb and maintain live BCG. The targeted mucosae were the oropharyngeal cavity (tonsils and sublingual area) and the small intestine (ileum). Results We showed that significant quantities of live BCG persisted within badger in tissues of vaccinated badgers for at least 8 weeks following oral vaccination with only very mild pathological features and induced the circulation of IFNγ-producing mononuclear cells. The uptake of live BCG by tonsils and drainage to retro-pharyngeal lymph nodes was repeatable in the animal group vaccinated by oropharyngeal instillation whereas those vaccinated directly in the ileum displayed a lower frequency of BCG detection in the enteric wall or draining mesenteric lymph nodes. No faecal excretion of live BCG was observed, including when BCG was delivered directly in the ileum. Conclusions The apparent local loss of BCG viability suggests an unfavorable gastro-enteric environment for BCG in badgers, which should be taken in consideration when developing an oral vaccine for use in this species.
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Affiliation(s)
- Sandrine Lesellier
- Animal and Plant Health Agency, New Haw, UK. .,Anses, Nancy laboratory for rabies and wildlife, Malzéville, France. .,Public Health England, Porton Down, UK.
| | - Maria-Laura Boschiroli
- Laboratory for Animal Health, Tuberculosis National Reference Laboratory, University Paris-Est, Anses, Maisons-Alfort, France
| | - Jacques Barrat
- Anses, Nancy laboratory for rabies and wildlife, Malzéville, France
| | - Christoph Wanke
- Medimetrics Personalized Drug Delivery B.V., High Tech Campus 10, 5656 AE, Eindhoven, The Netherlands
| | - Francisco J Salguero
- Animal and Plant Health Agency, New Haw, UK.,Public Health England, Porton Down, UK
| | | | - Alex Nunez
- Animal and Plant Health Agency, New Haw, UK
| | | | | | | | | | | | | | - Krystel de Cruz
- Laboratory for Animal Health, Tuberculosis National Reference Laboratory, University Paris-Est, Anses, Maisons-Alfort, France
| | - Sylvie Henault
- Laboratory for Animal Health, Tuberculosis National Reference Laboratory, University Paris-Est, Anses, Maisons-Alfort, France
| | - Lorraine Michelet
- Laboratory for Animal Health, Tuberculosis National Reference Laboratory, University Paris-Est, Anses, Maisons-Alfort, France
| | | | | | | | | | - Frank Boué
- Anses, Nancy laboratory for rabies and wildlife, Malzéville, France
| | - Mark A Chambers
- Animal and Plant Health Agency, New Haw, UK.,University of Surrey, Guildford, UK
| | - Céline Richomme
- Anses, Nancy laboratory for rabies and wildlife, Malzéville, France
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Development of a diagnostic compatible BCG vaccine against Bovine tuberculosis. Sci Rep 2019; 9:17791. [PMID: 31780694 PMCID: PMC6882907 DOI: 10.1038/s41598-019-54108-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 08/27/2019] [Indexed: 12/31/2022] Open
Abstract
Bovine tuberculosis (BTB) caused by Mycobacterium bovis remains a major problem in both the developed and developing countries. Control of BTB in the UK is carried out by test and slaughter of infected animals, based primarily on the tuberculin skin test (PPD). Vaccination with the attenuated strain of the M. bovis pathogen, BCG, is not used to control bovine tuberculosis in cattle at present, due to its variable efficacy and because it interferes with the PPD test. Diagnostic tests capable of Differentiating Infected from Vaccinated Animals (DIVA) have been developed that detect immune responses to M. bovis antigens absent in BCG; but these are too expensive and insufficiently sensitive to be used for BTB control worldwide. To address these problems we aimed to generate a synergistic vaccine and diagnostic approach that would permit the vaccination of cattle without interfering with the conventional PPD-based surveillance. The approach was to widen the pool of M. bovis antigens that could be used as DIVA targets, by identifying antigenic proteins that could be deleted from BCG without affecting the persistence and protective efficacy of the vaccine in cattle. Using transposon mutagenesis we identified genes that were essential and those that were non-essential for persistence in bovine lymph nodes. We then inactivated selected immunogenic, but non-essential genes in BCG Danish to create a diagnostic-compatible triple knock-out ΔBCG TK strain. The protective efficacy of the ΔBCG TK was tested in guinea pigs experimentally infected with M. bovis by aerosol and found to be equivalent to wild-type BCG. A complementary diagnostic skin test was developed with the antigenic proteins encoded by the deleted genes which did not cross-react in vaccinated or in uninfected guinea pigs. This study demonstrates the functionality of a new and improved BCG strain which retains its protective efficacy but is diagnostically compatible with a novel DIVA skin test that could be implemented in control programmes.
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Cicchese JM, Evans S, Hult C, Joslyn LR, Wessler T, Millar JA, Marino S, Cilfone NA, Mattila JT, Linderman JJ, Kirschner DE. Dynamic balance of pro- and anti-inflammatory signals controls disease and limits pathology. Immunol Rev 2018; 285:147-167. [PMID: 30129209 PMCID: PMC6292442 DOI: 10.1111/imr.12671] [Citation(s) in RCA: 145] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Immune responses to pathogens are complex and not well understood in many diseases, and this is especially true for infections by persistent pathogens. One mechanism that allows for long-term control of infection while also preventing an over-zealous inflammatory response from causing extensive tissue damage is for the immune system to balance pro- and anti-inflammatory cells and signals. This balance is dynamic and the immune system responds to cues from both host and pathogen, maintaining a steady state across multiple scales through continuous feedback. Identifying the signals, cells, cytokines, and other immune response factors that mediate this balance over time has been difficult using traditional research strategies. Computational modeling studies based on data from traditional systems can identify how this balance contributes to immunity. Here we provide evidence from both experimental and mathematical/computational studies to support the concept of a dynamic balance operating during persistent and other infection scenarios. We focus mainly on tuberculosis, currently the leading cause of death due to infectious disease in the world, and also provide evidence for other infections. A better understanding of the dynamically balanced immune response can help shape treatment strategies that utilize both drugs and host-directed therapies.
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Affiliation(s)
- Joseph M. Cicchese
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Stephanie Evans
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Caitlin Hult
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI, USA
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Louis R. Joslyn
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Timothy Wessler
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI, USA
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Jess A. Millar
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Simeone Marino
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Nicholas A. Cilfone
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Joshua T. Mattila
- Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Denise E. Kirschner
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, USA
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5
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Abstract
Tuberculosis infects millions of people worldwide and remains a leading global killer despite widespread neonatal administration of the tuberculosis vaccine, bacillus Calmette-Guérin (BCG). BCG has clear and sustained efficacy, but after 10 years, its efficacy appears to wane, at least in some populations. Fortunately, there are many new tuberculosis vaccines in development today, some in advanced stages of clinical trial testing. Here we review the epidemiological need for tuberculosis vaccination, including evolving standards for administration to at risk individuals in developing countries. We also examine proven sources of immune protection from tuberculosis, which to date have exclusively involved natural or vaccine exposure to whole cell mycobacteria. After summarizing evidence for the use and efficacy of BCG, we detail the most promising new candidate vaccines against tuberculosis. The global need for a new tuberculosis vaccine is acute and huge, but clinical trials to be completed in the coming few years are likely either to identify a new tuberculosis vaccine or to substantially reframe how we understand immune protection from this historical scourge.
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Caetano LA, Figueiredo L, Almeida AJ, Gonçalves LMD. BCG-loaded chitosan microparticles: interaction with macrophages and preliminary in vivo studies. J Microencapsul 2017; 34:203-217. [PMID: 28378596 DOI: 10.1080/02652048.2017.1316325] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The aim of this study was to develop a novel BCG-loaded chitosan vaccine with high association efficiency which can afford efficient interaction with APC and elicit local and Th1-type-specific immune response after intranasal administration. Chitosan-suspended BCG and BCG-loaded chitosan-alginate microparticles were prepared by ionotropic gelation. Interaction with APC was evaluated by fluorescence microscopy using rBCG-GFP. Specific immune responses were evaluated following intranasal immunisation of mice. Cellular uptake was approximately two-fold higher for chitosan-suspended BCG. A single dose of BCG-loaded microparticles or chitosan-suspended BCG by intranasal route improved Th1-type response compared with subcutaneous BCG. Chitosan-suspended BCG originated the highest mucosal response in the lungs by intranasal route. These positive results indicate that the proposed approach of whole live BCG microencapsulation in chitosan-alginate for intranasal immunisation was successful in allowing efficient interaction with APC, while improving the cellular immune response, which is of interest for local immunisation against tuberculosis.
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Affiliation(s)
- Liliana Aranha Caetano
- a Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy , University of Lisbon , Lisbon , Portugal.,b Department of Ciências e Tecnologias Laboratoriais e Saúde Comunitária, ESTeSL - Escola Superior de Tecnologia da Saúde de Lisboa , Instituto Politécnico de Lisboa , Lisbon , Portugal
| | - Lara Figueiredo
- a Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy , University of Lisbon , Lisbon , Portugal
| | - António J Almeida
- a Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy , University of Lisbon , Lisbon , Portugal
| | - L M D Gonçalves
- a Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy , University of Lisbon , Lisbon , Portugal
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Tree JA, Smith S, Baker N, Clark S, Aldwell FE, Chambers M, Williams A, Marsh PD. Method for assessing IFN-γ responses in guinea pigs during TB vaccine trials. Lett Appl Microbiol 2012; 55:295-300. [PMID: 22817339 DOI: 10.1111/j.1472-765x.2012.03292.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS We sought to develop a new method that enables the assessment of the immune response of guinea pigs during TB vaccine evaluation studies, without the need to cull or anaesthetize animals. METHOD AND RESULTS Guinea pigs were vaccinated with five different formulations of oral BCG. One week prior to challenge with Mycobacterium bovis, blood (50-200 μl) was taken from the ears of vaccinated subjects. Host RNA was isolated and amplified following antigenic restimulation of PBMCs for 24 h with 30 μg of bovine PPD. The up- or down-regulation of γ-interferon (IFN-γ), a key cytokine involved in protection against tuberculosis, was assessed using real-time PCR. The relative expression of prechallenge IFN-γ mRNA in the vaccinated groups (n=5) correlated (P<0·001) with protection against M. bovis challenge. CONCLUSION We have demonstrated that it is possible to take blood samples and track IFN-γ responses in guinea pigs that then go on to be exposed to M. bovis, thus providing prechallenge vaccine uptake information. SIGNIFICANCE AND IMPACT OF THE STUDY This methodology will also be applicable for tracking the immune responses of vaccinated guinea pigs over time that then go on to be challenged with M. tuberculosis during human TB vaccine evaluation studies.
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Affiliation(s)
- J A Tree
- Microbiology Services, Health Protection Agency, Wiltshire, UK.
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Abstract
Whilst oral vaccination is a potentially preferred route in terms of patient adherence and mass vaccination, the ability to formulate effective oral vaccines remains a challenge. The primary barrier to oral vaccination is effective delivery of the vaccine through the GI tract owing to the many obstacles it presents, including low pH, enzyme degradation and bile-salt solubilization, which can result in breakdown/deactivation of a vaccine. For effective immune responses after oral administration, particulates need to be taken up by the M cells however, these are few in number. To enhance M-cell uptake, particle characteristics can be optimized with particle size, surface charge, targeting groups and bioadhesive properties all being considerations. Yet improved uptake may not translate into enhanced immune responses and formulating particulates with inherent adjuvant properties can offer advantages. Within this article, we establish the options available for consideration when building effective oral particulate vaccines.
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Corner LAL, Costello E, O'Meara D, Lesellier S, Aldwell FE, Singh M, Hewinson RG, Chambers MA, Gormley E. Oral vaccination of badgers (Meles meles) with BCG and protective immunity against endobronchial challenge with Mycobacterium bovis. Vaccine 2010; 28:6265-72. [PMID: 20637774 DOI: 10.1016/j.vaccine.2010.06.120] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Revised: 06/18/2010] [Accepted: 06/30/2010] [Indexed: 10/19/2022]
Abstract
Eurasian badgers (Meles meles) are a reservoir host of Mycobacterium bovis and are implicated in the transmission of tuberculosis to cattle in Ireland and Great Britain. The development of a vaccine for use in badgers is considered a key element of any long-term sustainable campaign to eradicate the disease from livestock in both countries. The aim of this study was to investigate the protective response of badgers vaccinated orally with Bacille Calmette-Guérin (BCG) encapsulated in a lipid formulation, followed by experimental challenge with M. bovis. A group of badgers was vaccinated by inoculating the BCG-lipid mixture containing approximately 10(8)colony forming units (cfu) of BCG into the oesophagus. The control group was sham inoculated with the lipid formulation only. Thirteen weeks after vaccination all the badgers were challenged with approximately 10(4)cfu of M. bovis delivered by endobronchial inoculation. Blood samples were taken throughout the study and the cell mediated immune (CMI) responses in peripheral blood were monitored by the IFN-gamma ELISA and ELISPOT assay. At 17 weeks after infection all the badgers were examined post-mortem to assess the pathological and bacteriological responses to challenge. All badgers in both groups were found to be infected. However, a significant protective effect of BCG vaccination was measured as a decrease in the number and severity of gross lesions, lower bacterial load in the lungs, and fewer sites of infection. The analysis of immune responses showed that vaccination with BCG did not generate any detectable CMI immunological responses, however the levels of the responses increased in both groups following M. bovis infection. The results of the study showed that vaccination with oral BCG in the lipid formulation generated a protective effect in the badgers.
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Affiliation(s)
- Leigh A L Corner
- School of Agriculture, Food Science & Veterinary Medicine, University College Dublin, Dublin 4, Ireland
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Murine immune responses to oral BCG immunization in the presence or absence of prior BCG sensitization. Immunol Cell Biol 2009; 88:224-7. [PMID: 19918257 DOI: 10.1038/icb.2009.85] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Oral delivery of live Mycobacterium bovis BCG in a lipid matrix invokes cell-mediated immune (CMI) responses in mice and consequent protection against pulmonary challenge with virulent mycobacteria. To investigate the influence of prior BCG sensitization on oral vaccine efficacy, we assessed CMI responses and BCG colonization of the alimentary tract lymphatics 5 months after oral vaccination, in both previously naive mice and in mice that had been sensitized to BCG by injection 6 months previously. CMI responses did not differ significantly between mice that received subcutaneous BCG followed by oral BCG and those that received either injected or oral BCG alone. In vivo BCG colonization was predominant in the mesenteric lymph nodes after oral vaccination; this colonizing ability was not influenced by prior BCG sensitization. From this murine model study, we conclude that although prior parenteral-route BCG sensitization does not detrimentally affect BCG colonization after oral vaccination, there is no significant immune-boosting effect of the oral vaccine either.
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