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Abstract
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The development of
lipopeptides (lipidated peptides) for vaccines
is discussed, including their role as antigens and/or adjuvants. Distinct
classes of lipopeptide architectures are covered including simple
linear and ligated constructs and lipid core peptides. The design,
synthesis, and immunological responses of the important class of glycerol-based
Toll-like receptor agonist lipopeptides such as Pam3CSK4, which contains three palmitoyl chains and a CSK4 hexapeptide sequence, and many derivatives of this model immunogenic
compound are also reviewed. Self-assembled lipopeptide structures
including spherical and worm-like micelles that have been shown to
act as vaccine agents are also described. The work discussed includes
examples of lipopeptides developed with model antigens, as well as
for immunotherapies to treat many infectious diseases including malaria,
influenza, hepatitis, COVID-19, and many others, as well as cancer
immunotherapies. Some of these have proceeded to clinical development.
The research discussed highlights the huge potential of, and diversity
of roles for, lipopeptides in contemporary and future vaccine development.
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Affiliation(s)
- Ian W Hamley
- Department of Chemistry, University of Reading, Whiteknights, Reading RG6 6AD, U.K
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2
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Girkin J, Loo SL, Esneau C, Maltby S, Mercuri F, Chua B, Reid AT, Veerati PC, Grainge CL, Wark PAB, Knight D, Jackson D, Demaison C, Bartlett NW. TLR2-mediated innate immune priming boosts lung anti-viral immunity. Eur Respir J 2021; 58:13993003.01584-2020. [PMID: 33303547 DOI: 10.1183/13993003.01584-2020] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 11/27/2020] [Indexed: 01/07/2023]
Abstract
BACKGROUND We assessed whether Toll-like receptor (TLR)2 activation boosts the innate immune response to rhinovirus infection, as a treatment strategy for virus-induced respiratory diseases. METHODS We employed treatment with a novel TLR2 agonist (INNA-X) prior to rhinovirus infection in mice, and INNA-X treatment in differentiated human bronchial epithelial cells derived from asthmatic-donors. We assessed viral load, immune cell recruitment, cytokines, type I and III interferon (IFN) production, as well as the lung tissue and epithelial cell immune transcriptome. RESULTS We show, in vivo, that a single INNA-X treatment induced innate immune priming characterised by low-level IFN-λ, Fas ligand, chemokine expression and airway lymphocyte recruitment. Treatment 7 days before infection significantly reduced lung viral load, increased IFN-β/λ expression and inhibited neutrophilic inflammation. Corticosteroid treatment enhanced the anti-inflammatory effects of INNA-X. Treatment 1 day before infection increased expression of 190 lung tissue immune genes. This tissue gene expression signature was absent with INNA-X treatment 7 days before infection, suggesting an alternate mechanism, potentially via establishment of immune cell-mediated mucosal innate immunity. In vitro, INNA-X treatment induced a priming response defined by upregulated IFN-λ, chemokine and anti-microbial gene expression that preceded an accelerated response to infection enriched for nuclear factor (NF)-κB-regulated genes and reduced viral loads, even in epithelial cells derived from asthmatic donors with intrinsic delayed anti-viral immune response. CONCLUSION Airway epithelial cell TLR2 activation induces prolonged innate immune priming, defined by early NF-κB activation, IFN-λ expression and lymphocyte recruitment. This response enhanced anti-viral innate immunity and reduced virus-induced airway inflammation.
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Affiliation(s)
- Jason Girkin
- Viral Immunology and Respiratory Disease group, University of Newcastle, Newcastle, Australia.,Priority Research Centre for Healthy Lungs, University of Newcastle and Hunter Medical Research Institute, Newcastle, Australia.,These authors contributed equally
| | - Su-Ling Loo
- Viral Immunology and Respiratory Disease group, University of Newcastle, Newcastle, Australia.,Priority Research Centre for Healthy Lungs, University of Newcastle and Hunter Medical Research Institute, Newcastle, Australia.,These authors contributed equally
| | - Camille Esneau
- Viral Immunology and Respiratory Disease group, University of Newcastle, Newcastle, Australia.,Priority Research Centre for Healthy Lungs, University of Newcastle and Hunter Medical Research Institute, Newcastle, Australia
| | - Steven Maltby
- Viral Immunology and Respiratory Disease group, University of Newcastle, Newcastle, Australia.,Priority Research Centre for Healthy Lungs, University of Newcastle and Hunter Medical Research Institute, Newcastle, Australia
| | | | - Brendon Chua
- Dept of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia
| | - Andrew T Reid
- Viral Immunology and Respiratory Disease group, University of Newcastle, Newcastle, Australia.,Priority Research Centre for Healthy Lungs, University of Newcastle and Hunter Medical Research Institute, Newcastle, Australia
| | - Punnam Chander Veerati
- Viral Immunology and Respiratory Disease group, University of Newcastle, Newcastle, Australia.,Priority Research Centre for Healthy Lungs, University of Newcastle and Hunter Medical Research Institute, Newcastle, Australia
| | - Chris L Grainge
- Priority Research Centre for Healthy Lungs, University of Newcastle and Hunter Medical Research Institute, Newcastle, Australia.,Dept of Respiratory and Sleep Medicine, John Hunter Hospital, Newcastle, Australia
| | - Peter A B Wark
- Priority Research Centre for Healthy Lungs, University of Newcastle and Hunter Medical Research Institute, Newcastle, Australia.,Dept of Respiratory and Sleep Medicine, John Hunter Hospital, Newcastle, Australia
| | - Darryl Knight
- Priority Research Centre for Healthy Lungs, University of Newcastle and Hunter Medical Research Institute, Newcastle, Australia
| | - David Jackson
- Dept of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia
| | | | - Nathan W Bartlett
- Viral Immunology and Respiratory Disease group, University of Newcastle, Newcastle, Australia .,Priority Research Centre for Healthy Lungs, University of Newcastle and Hunter Medical Research Institute, Newcastle, Australia
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Mangas KM, Tobias NJ, Marion E, Babonneau J, Marsollier L, Porter JL, Pidot SJ, Wong CY, Jackson DC, Chua BY, Stinear TP. High antibody titres induced by protein subunit vaccines using Mycobacterium ulcerans antigens Hsp18 and MUL_3720 with a TLR-2 agonist fail to protect against Buruli ulcer in mice. PeerJ 2020; 8:e9659. [PMID: 32844063 PMCID: PMC7416718 DOI: 10.7717/peerj.9659] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 07/14/2020] [Indexed: 12/26/2022] Open
Abstract
Background Mycobacterium ulcerans is the causative agent of a debilitating skin and soft tissue infection known as Buruli ulcer (BU). There is no vaccine against BU. The purpose of this study was to investigate the vaccine potential of two previously described immunogenic M. ulcerans proteins, MUL_3720 and Hsp18, using a mouse tail infection model of BU. Methods Recombinant versions of the two proteins were each electrostatically coupled with a previously described lipopeptide adjuvant. Seven C57BL/6 and seven BALB/c mice were vaccinated and boosted with each of the formulations. Vaccinated mice were then challenged with M. ulcerans via subcutaneous tail inoculation. Vaccine performance was assessed by time-to-ulceration compared to unvaccinated mice. Results The MUL_3720 and Hsp18 vaccines induced high titres of antigen-specific antibodies that were predominately subtype IgG1. However, all mice developed ulcers by day-40 post-M. ulcerans challenge. No significant difference was observed in the time-to-onset of ulceration between the experimental vaccine groups and unvaccinated animals. Conclusions These data align with previous vaccine experiments using Hsp18 and MUL_3720 that indicated these proteins may not be appropriate vaccine antigens. This work highlights the need to explore alternative vaccine targets and different approaches to understand the role antibodies might play in controlling BU.
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Affiliation(s)
- Kirstie M Mangas
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| | - Nicholas J Tobias
- Johann Wolfgang Goethe Universität Frankfurt am Main, Frankfurt, Germany.,LOEWE Centre for Translational Biodiversity in Genomics (TBG), Frankfurt, Germany
| | - Estelle Marion
- Université de Nantes, Nantes, France.,Université de Nantes, Nantes, France.,Université d'Angers, Angers, France
| | - Jérémie Babonneau
- Université de Nantes, Nantes, France.,Université d'Angers, Angers, France
| | - Laurent Marsollier
- Université de Nantes, Nantes, France.,Université d'Angers, Angers, France
| | - Jessica L Porter
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| | - Sacha J Pidot
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| | - Chinn Yi Wong
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| | - David C Jackson
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| | - Brendon Y Chua
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| | - Timothy P Stinear
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
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Zeng W, Horrocks KJ, Tan ACL, Wong CY, Chua BY, Jackson DC. Modular platforms for the assembly of self-adjuvanting lipopeptide-based vaccines for use in an out-bred population. Vaccine 2020; 38:597-607. [PMID: 31740096 DOI: 10.1016/j.vaccine.2019.10.055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 10/19/2019] [Accepted: 10/20/2019] [Indexed: 01/08/2023]
Abstract
To facilitate the preparation of synthetic epitope-based self-adjuvanting vaccines capable of eliciting antibody responses in an out-bred population, we have developed two modular approaches. In the first, the Toll-like receptor 2 agonist Pam2Cys and the target antibody epitope are assembled as a module which is then coupled to a carrier protein as a source of antigens to stimulate T cell help. A vaccine candidate made in this way was shown to induce a specific immune response in four different strains of mice without the need for extraneous adjuvant. In the second approach, three vaccine components in the form of a target antibody epitope, a T helper cell epitope and Pam2Cys, were prepared separately each carrying different chemical functional groups. By using pH-mediated chemo-selective ligations, the vaccine was assembled in a one-pot procedure. Using this approach, a number of vaccine constructs including a lipopeptide-protein conjugate were made and also shown to elicit immune responses in different strains of mice. These two modular approaches thus constitute a powerful platform for the assembly of self-adjuvanting lipopeptide-based vaccines that can potentially be used to induce robust antibody responses in an outbred population. Finally, our study of the impact of chemical linkages on immunogenicity of a lipopeptide vaccine shows that a stable covalent bond between Pam2Cys and a B cell epitope, rather than between Pam2Cys and T helper cell epitope is critical for the induction of antibody responses and biological efficacy, indicating that Pam2Cys functions not only as an adjuvant but also participates in processing and presentation of the immunogen.
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Affiliation(s)
- Weiguang Zeng
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Parkville 3010, Victoria, Australia.
| | - Kylie J Horrocks
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Parkville 3010, Victoria, Australia
| | - Amabel C L Tan
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Parkville 3010, Victoria, Australia
| | - Chinn Yi Wong
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Parkville 3010, Victoria, Australia
| | - Brendon Y Chua
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Parkville 3010, Victoria, Australia
| | - David C Jackson
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Parkville 3010, Victoria, Australia
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Lu BL, Williams GM, Brimble MA. TLR2 agonists and their structure–activity relationships. Org Biomol Chem 2020; 18:5073-5094. [DOI: 10.1039/d0ob00942c] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We review the structure–activity relationships and synthetic studies of TLR2 agonists – important chemical targets in immunotherapy.
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Affiliation(s)
- Benjamin L. Lu
- The School of Biological Sciences
- University of Auckland
- Auckland 1010
- New Zealand
- The School of Chemical Sciences
| | - Geoffrey M. Williams
- The School of Biological Sciences
- University of Auckland
- Auckland 1010
- New Zealand
- The School of Chemical Sciences
| | - Margaret A. Brimble
- The School of Biological Sciences
- University of Auckland
- Auckland 1010
- New Zealand
- The School of Chemical Sciences
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Lu BL, Williams GM, Verdon DJ, Dunbar PR, Brimble MA. Synthesis and Evaluation of Novel TLR2 Agonists as Potential Adjuvants for Cancer Vaccines. J Med Chem 2019; 63:2282-2291. [PMID: 31418565 DOI: 10.1021/acs.jmedchem.9b01044] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cancer immunotherapy has gained increasing attention due to its potential specificity and lack of adverse side effects when compared to more traditional modes of treatment. Toll-like receptor 2 (TLR2) agonists are lipopeptides possessing the S-[2,3-bis(palmitoyloxy)propyl]-l-cysteine (Pam2Cys) motif and exhibit potent immunostimulatory effects. These agonists offer a means of providing "danger signals" in order to activate the immune system toward tumor antigens. Thus, the development of TLR2 agonists is attractive in the search of potential immunostimulants for cancer. Existing SAR studies of Pam2Cys with TLR2 indicate that the structural requirements for activity are, for the most part, very intolerable. We have investigated the importance of stereochemistry, the effect of N-terminal acylation, and homologation between the two ester functionalities in Pam2Cys-conjugated lipopeptides on TLR2 activity. The R diastereomer is significantly more potent than the S diastereomer and N-terminal modification generally lowers TLR2 activity. Most notably, homologation gives rise to analogues which are comparatively active to the native Pam2Cys containing constructs.
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Affiliation(s)
- Benjamin L Lu
- School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland 1010, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds Street 1010, Auckland, New Zealand
| | - Geoffrey M Williams
- School of Biological Sciences, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds Street 1010, Auckland, New Zealand
| | - Daniel J Verdon
- School of Biological Sciences, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds Street 1010, Auckland, New Zealand
| | - P Rod Dunbar
- School of Biological Sciences, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds Street 1010, Auckland, New Zealand
| | - Margaret A Brimble
- School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland 1010, New Zealand.,School of Biological Sciences, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds Street 1010, Auckland, New Zealand
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Wijayadikusumah AR, Zeng W, McQuilten HA, Wong CY, Jackson DC, Chua BY. Geometry of a TLR2-Agonist-Based Adjuvant Can Affect the Resulting Antigen-Specific Immune Response. Mol Pharm 2019; 16:2037-2047. [PMID: 30924661 DOI: 10.1021/acs.molpharmaceut.9b00026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Targeted delivery of otherwise nonimmunogenic antigens to Toll-like receptors (TLRs) expressed on dendritic cells (DCs) has proven to be an effective means of improving immunogenicity. For this purpose, we have used a branched cationic lipopeptide, R4Pam2Cys, which is an agonist for TLR2 and enables electrostatic association with antigen for this purpose. Here, we compare the immunological properties of ovalbumin formulated with different geometrical configurations of R4Pam2Cys. Our results demonstrate that notwithstanding the presence of the same adjuvant, branched forms of R4Pam2Cys are more effective at inducing immune responses than are linear geometries. CD8+ T-cell-mediated responses are particularly improved, resulting in significantly higher levels of antigen-specific cytokine secretion and cytolysis of antigen-bearing target cells in vivo. The results correlate with the ability of branched R4Pam2Cys conformations to encourage higher levels of DC maturation and facilitate superior antigen uptake, leading to increased production of proinflammatory cytokines. These differences are not attributable to particle size because both branched and linear lipopeptides associate with antigen-forming complexes of similar size, but rather the ability of branched lipopeptides to induce more efficient TLR2-mediated cell signaling. Branched lipopeptides are also more resistant to trypsin-mediated proteolysis, suggesting greater stability than their linear counterparts. The branched lipopeptide facilitates presentation of antigen more efficiently to CD8+ T cells, resulting in rapid cell division and upregulation of early cell surface activation markers. These results as well as cognate recognition of Pam2Cys by TLR2 indicate that the adjuvant's efficiency is also dependent on its geometry.
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Affiliation(s)
- Acep R Wijayadikusumah
- Department of Microbiology and Immunology , The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity , 792 Elizabeth Street , Melbourne , Victoria 3010 , Australia.,Research and Development Division , PT. Bio Farma (Persero) , 28 Pasteur Street , Bandung , West Java 40161 , Indonesia
| | - Weiguang Zeng
- Department of Microbiology and Immunology , The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity , 792 Elizabeth Street , Melbourne , Victoria 3010 , Australia
| | - Hayley A McQuilten
- Department of Microbiology and Immunology , The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity , 792 Elizabeth Street , Melbourne , Victoria 3010 , Australia
| | - Chinn Yi Wong
- Department of Microbiology and Immunology , The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity , 792 Elizabeth Street , Melbourne , Victoria 3010 , Australia
| | - David C Jackson
- Department of Microbiology and Immunology , The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity , 792 Elizabeth Street , Melbourne , Victoria 3010 , Australia
| | - Brendon Y Chua
- Department of Microbiology and Immunology , The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity , 792 Elizabeth Street , Melbourne , Victoria 3010 , Australia
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