Deciphering protective immunity by multimodal mass spectrometry: Towards epitope-focused streptococcal vaccines
Tang, Di LU
(2025)
In Lund University, Faculty of Medicine Doctoral Dissertation Series
- Abstract
Group A Streptococcus (GAS)causes infections ranging from mild sore throats to severe invasive disease; however, no licensed vaccine is currently available. In this thesis, the author leverages streptolysin O (SLO), an important GAS protein and therapeutic/vaccine target, as a model system to develop a multimodal protein mass spectrometry(MS) strategy. Through an integrated approach of MS-based proteomics, biochemical assays, and computational modelling, the author reveals that SLO not only forms pores in cell membranes but also modulates human fibrinolytic pathways, potentially enhancing bacterial dissemination. Mapping the immunologically relevant regions (namely epitopes) of SLO... (More)
Group A Streptococcus (GAS)causes infections ranging from mild sore throats to severe invasive disease; however, no licensed vaccine is currently available. In this thesis, the author leverages streptolysin O (SLO), an important GAS protein and therapeutic/vaccine target, as a model system to develop a multimodal protein mass spectrometry(MS) strategy. Through an integrated approach of MS-based proteomics, biochemical assays, and computational modelling, the author reveals that SLO not only forms pores in cell membranes but also modulates human fibrinolytic pathways, potentially enhancing bacterial dissemination. Mapping the immunologically relevant regions (namely epitopes) of SLO reveals a site that can elicit potent protective immune responses. Building on these insights, the author constructs a prototype vaccine by multivalently displaying redesigned SLO-derived epitopes on self-assembling protein nanoparticles, resulting in enhanced immunity and improved protection in a pilot mouse model. To demonstrate the broader applicability of this antibody-guided MS workflow, the author extends it to pneumolysin, a homologous cytolysin from Streptococcus pneumoniae, illustrating how the same methodologies can decipher epitope-specific correlates of antibody functionality against other complex bacterial antigens. In summary, this thesis highlights the potential of an integrated MS-based approach to uncover bacterial virulence mechanisms, define epitopes of biological relevance, and facilitate data-driven immunogen design. By combining complementary structural and functional analyses with the promising epitope-focused vaccine modality, the thesis offers a practical roadmap for tackling GAS infections and potentially other challenging microbial pathogens.
(Less)
- author
- Tang, Di
LU
- supervisor
- opponent
-
- Director Beck, Martin, Max Planck Institute for Biophysics, Frankfurt, Germany
- organization
- publishing date
- 2025
- type
- Thesis
- publication status
- published
- subject
- keywords
- Streptococcus pyogenes (GAS), Streptolysin O, host-pathogen interactions, protein-protein interactions, mass spectrometry (MS), proteomics, structural biology, cytolysin, antibody-antigen interactions, epitope mapping, structure modeling, protein design, protein-based vaccine, nanoparticle, cryo-electron microscopy (cryo-EM)
- in
- Lund University, Faculty of Medicine Doctoral Dissertation Series
- issue
- 24
- pages
- 93 pages
- publisher
- Lund University, Faculty of Medicine
- defense location
- Belfragesalen, BMC D15, Klinikgatan 32 i Lund
- defense date
- 2025-03-14 09:00:00
- ISSN
- 1652-8220
- ISBN
- 978-91-8021-677-7
- project
- Properties of Protective Antibody Responses against Bacterial Pathogens
- language
- English
- LU publication?
- yes
- id
- aab98746-2e71-4dbb-99c4-0ce9f0680923
- date added to LUP
- 2025-02-19 12:23:46
- date last changed
- 2025-06-03 18:30:30
@phdthesis{aab98746-2e71-4dbb-99c4-0ce9f0680923,
abstract = {{<p class="MsoNormal" style="text-align:justify">Group A <i>Streptococcus </i>(GAS)causes infections ranging from mild sore throats to severe invasive disease; however, no licensed vaccine is currently available. In this thesis, the author leverages streptolysin O (SLO), an important GAS protein and therapeutic/vaccine target, as a model system to develop a multimodal protein mass spectrometry(MS) strategy. Through an integrated approach of MS-based proteomics, biochemical assays, and computational modelling, the author reveals that SLO not only forms pores in cell membranes but also modulates human fibrinolytic pathways, potentially enhancing bacterial dissemination. Mapping the immunologically relevant regions (namely epitopes) of SLO reveals a site that can elicit potent protective immune responses. Building on these insights, the author constructs a prototype vaccine by multivalently displaying redesigned SLO-derived epitopes on self-assembling protein nanoparticles, resulting in enhanced immunity and improved protection in a pilot mouse model. To demonstrate the broader applicability of this antibody-guided MS workflow, the author extends it to pneumolysin, a homologous cytolysin from <i>Streptococcus pneumoniae</i>, illustrating how the same methodologies can decipher epitope-specific correlates of antibody functionality against other complex bacterial antigens. In summary, this thesis highlights the potential of an integrated MS-based approach to uncover bacterial virulence mechanisms, define epitopes of biological relevance, and facilitate data-driven immunogen design. By combining complementary structural and functional analyses with the promising epitope-focused vaccine modality, the thesis offers a practical roadmap for tackling GAS infections and potentially other challenging microbial pathogens.</p>}},
author = {{Tang, Di}},
isbn = {{978-91-8021-677-7}},
issn = {{1652-8220}},
keywords = {{Streptococcus pyogenes (GAS); Streptolysin O; host-pathogen interactions; protein-protein interactions; mass spectrometry (MS); proteomics; structural biology; cytolysin; antibody-antigen interactions; epitope mapping; structure modeling; protein design; protein-based vaccine; nanoparticle; cryo-electron microscopy (cryo-EM)}},
language = {{eng}},
number = {{24}},
publisher = {{Lund University, Faculty of Medicine}},
school = {{Lund University}},
series = {{Lund University, Faculty of Medicine Doctoral Dissertation Series}},
title = {{Deciphering protective immunity by multimodal mass spectrometry: Towards epitope-focused streptococcal vaccines}},
url = {{https://lup.lub.lu.se/search/files/208798586/e-nailing_ex_Di.pdf}},
year = {{2025}},
}