Duverger, Alexandra (2007) Regulation of mucosal immune responses by anthrax edema toxin derivatives. PhD thesis Immunologie des muqueuses, Department of Biosciences - Ohio State University Medicine Colombus , AgroParistech 2007AGPT0044 p.113.
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Abstract
Mucosal vaccines can be easily administered and favor humoral and cell-mediated immunity at mucosal sites. Thus, mucosal vaccines most likely offer optimal protection against pathogens that invade the host via mucosal surfaces. However, licensing of new mucosal vaccines is hampered by the lack of safe and efficacious mucosal adjuvants. The enterotoxin cholera toxin (CT) is a powerful adjuvant but its toxicity precludes its use in humans. As experimental models, enterotoxins have highlighted the importance of the enzymatic activity and targeted receptors in their adjuvanticity. Our work stems from the observation that sublethal doses of Bacillus anthracis edema toxin (EdTx) do not inhibit immune responses to nasal vaccines containing CT as adjuvant. We have now shown that EdTx derivatives represent a new class of adjuvants, which promote mucosal and systemic immune responses to vaccines given via multiple routes. We demonstrated that EdTx is capable of inducing systemic and mucosal immunity to protein vaccines administered nasally. Unlike the ganglioside-binding CT, EdTx, which bind the anthrax toxin receptors, do not target central nervous system tissues after nasal delivery. Furthermore, the innate factor nerve growth factor, which plays a role in the induction of mucosal immune responses by CT, did not affect the adjuvant activity of EdTx in vivo. We have established that the adjuvant activity of EdTx involves the enhancement of antigen presenting cell functions. Finally, we showed that EdTx is an effective adjuvant via both the transcutaneous and sublingual routes, although it could give rise to mucosal IgA responses only after sublingual immunization.
| Item Type: | PhD Thesis (PhD) |
|---|---|
| PhD Supervisor: | Boyaka, Prosper N. |
| Date: | 12 December 2007 |
| Board of examiners: | Tomé, Daniel and Bomsel, Morgane and Kapel, Nathalie and Tinsley, Colin |
| Ecole Doctorale: | ED 435 AGRICULTURE, ALIMENTATION, BIOLOGIE, ENVIRONNEMENTS ET SANTE |
| Discipline: | Immunologie des muqueuses |
| Collection (Fonds): | AgroParistech |
| Institution: | AgroParistech |
| Department: | Department of Biosciences - Ohio State University Medicine Colombus |
| Subjects: | 7. Life Sciences and Engineering |
| Uncontrolled Keywords: | Anthrax, Anthrax, Toxins, Toxines, Adjuvant, Adjuvant, Nasal, Nasal, Cutané, Cutaneous, Sublingual, Sublingual, Mucosal, Muqueux, Immunity, Immunité, IgA, IgA |
| ID Code: | 4594 |
| Deposited By: | Marina Briffaut |
| Deposited On: | 19 January 2009 |
Table of content
1 FIGURES AND TABLES - 13
2 ABBREVIATIONS - 16
3 INTRODUCTION - 18
3.1 The mucosal immune system - 18
3.1.1 The mucosal surfaces - 18
3.1.2 Compartimentalization of the mucosal immune system - 19
3.2 Mucosal vaccines and adjuvants - 32
3.2.1 Mucosal vaccines against infections - 32
3.2.2 Vaccine adjuvants and mucosal adjuvants - 36
3.2.3 Current mucosal adjuvants - 38
3.3 Anthrax - 48
3.3.1 Bacillus anthracis infection and anthrax disease - 48
3.3.2 Mode of action of anthrax toxin complexes - 49
3.3.3 Use of anthrax toxins in immune therapy - 52
4 AIM OF THE STUDY - 55
4.1 General aim - 55
4.2 Specific aims - 56
5 RESULTS - 58
5.1 Anthrax edema toxin is an adjuvant for nasal vaccine antigens and promotes SIgA antibodies - 59
5.2 Anthrax edema toxin is an adjuvant for its binding subunit and promotes anti-PA antibodies, which protect
macrophages against LeTx-induced death - 61
5.3 EdTx as a nasal adjuvant induces antigen-specific Th1 and Th2 cell cytokine responses - 63
5.4 Nasal EdTx does not exhibit the safety issues associated with ganglioside-binding enterotoxins - 64
5.5 Role of the binding subunit PA in the nasal adjuvanticity of EdTx in vivo - 65
5.6 An enzymatically active EF is needed for the nasal adjuvanticity of EdTx in vivo - 68
5.7 Involvement of innate immunity components in edema toxin adjuvanticity - 69
5.7.1 Proinflammatory cytokines do not play a major role in the adjuvant activity of EdTx derivatives - 69
5.7.2 Effect of EdTx subunits and mutant derivatives on costimulatory molecule expression and antigen
uptake by macrophages - 71
5.7.3 Role of Nerve Growth Factor in the adjuvant activity of EdTx - 73
5.8 Edema toxin acts as an adjuvant for serum Ab responses to topically co-applied vaccine antigens - 78
5.9 Antibody responses induced by EdTx as a transcutaneous adjuvant in saliva and mucosal secretions - 80
5.9.1 CT and EdTx differentially affect immune cells in the GI tract after TCI application - 81
5.10 Topical application of EdTx promotes immunity to anthrax toxin components - 82
5.11 The transcutaneous adjuvant edema toxin promotes mixed Th1 and Th2 cytokine and delayed-type
hypersensitivity responses - 84
5.12 Sublingual immunization with EdTx as adjuvant - 85
5.13 EdTx is an adjuvant for systemic vaccines - 88
6 DISCUSSION - 91
6.1 The ATR-binding EdTx is an adjuvant for non-invasive vaccines - 91
6.1.1 Requirement for enzymatic activity of EF - 92
6.1.2 Potential adverse effects - 93
6.2 Quality of immune responses induced by EdTx as adjuvant for non-invasive vaccines - 93
6.2.1 EdTx induces Abs that neutralize anthrax toxin in vitro - 93
6.2.2 T helper cytokine and DTH responses - 94
6.2.3 Mucosal IgA Ab responses - 95
6.3 Mechanisms of adjuvanticity of EdTx for non-invasive vaccines - 95
6.3.1 Contribution of innate immune factors - 95
6.3.2 Imprinting of homing properties on immunocytes - 96
7 GENERAL SUMMARY AND CONCLUSION - 99
8 LIST OF PUBLICATIONS* - 102
9 REFERENCES - 104
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