Mucins regulate virulence and colonization factors in Streptococcus pneumoniae

Mucus covers all wet epithelia in the human body, creating a protective barrier for the underlying cell layer, and accommodating trillions of microbes that make up the microbiota. Mucin glycoproteins, the main gel-forming component of mucus, have emerged as multifaceted regulators of microbial physi...

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Main Author: Bath, Jade Rose
Other Authors: Ribbeck, Katharina
Format: Thesis
Published: Massachusetts Institute of Technology 2024
Online Access:https://hdl.handle.net/1721.1/156937
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author Bath, Jade Rose
author2 Ribbeck, Katharina
author_facet Ribbeck, Katharina
Bath, Jade Rose
author_sort Bath, Jade Rose
collection MIT
description Mucus covers all wet epithelia in the human body, creating a protective barrier for the underlying cell layer, and accommodating trillions of microbes that make up the microbiota. Mucin glycoproteins, the main gel-forming component of mucus, have emerged as multifaceted regulators of microbial physiology and microbial communities. Defects in mucus production or changes in mucin glycosylation are associated with microbial dysbiosis, where the outgrowth of opportunistic pathogens threatens human health. Streptococcus pneumoniae is a ubiquitous opportunistic pathogen, able to both asymptomatically colonize the microbiota of healthy children and adults and to cause invasive diseases. The mechanisms by which the body tolerates the presence of S. pneumoniae as part of the microbiota remain largely unknown. In this thesis, I fill this gap by exploring how S. pneumoniae senses and responds to the mucin environment. First, I identify that mucins downregulate a key virulence factor of S. pneumoniae, the cytolytic toxin pneumolysin (PLY). I show that through the regulation of PLY, mucin protects host cells from toxin-mediated killing and modulates inflammatory signals. Second, I identify that mucins downregulate colonization factors in S. pneumoniae, modulating microbe-microbe interactions between nasopharyngeal bacteria. Together, these results uncover novel mechanisms for how mucin tames opportunistic pathogens and provides insight for the development of novel therapeutics to treat S. pneumoniae infection.
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spelling mit-1721.1/1569372024-09-25T03:29:30Z Mucins regulate virulence and colonization factors in Streptococcus pneumoniae Bath, Jade Rose Ribbeck, Katharina Massachusetts Institute of Technology. Department of Biology Massachusetts Institute of Technology. Microbiology Graduate Program Mucus covers all wet epithelia in the human body, creating a protective barrier for the underlying cell layer, and accommodating trillions of microbes that make up the microbiota. Mucin glycoproteins, the main gel-forming component of mucus, have emerged as multifaceted regulators of microbial physiology and microbial communities. Defects in mucus production or changes in mucin glycosylation are associated with microbial dysbiosis, where the outgrowth of opportunistic pathogens threatens human health. Streptococcus pneumoniae is a ubiquitous opportunistic pathogen, able to both asymptomatically colonize the microbiota of healthy children and adults and to cause invasive diseases. The mechanisms by which the body tolerates the presence of S. pneumoniae as part of the microbiota remain largely unknown. In this thesis, I fill this gap by exploring how S. pneumoniae senses and responds to the mucin environment. First, I identify that mucins downregulate a key virulence factor of S. pneumoniae, the cytolytic toxin pneumolysin (PLY). I show that through the regulation of PLY, mucin protects host cells from toxin-mediated killing and modulates inflammatory signals. Second, I identify that mucins downregulate colonization factors in S. pneumoniae, modulating microbe-microbe interactions between nasopharyngeal bacteria. Together, these results uncover novel mechanisms for how mucin tames opportunistic pathogens and provides insight for the development of novel therapeutics to treat S. pneumoniae infection. Ph.D. 2024-09-24T18:21:44Z 2024-09-24T18:21:44Z 2024-05 2024-07-12T17:16:12.986Z Thesis https://hdl.handle.net/1721.1/156937 In Copyright - Educational Use Permitted Copyright retained by author(s) https://rightsstatements.org/page/InC-EDU/1.0/ application/pdf Massachusetts Institute of Technology
spellingShingle Bath, Jade Rose
Mucins regulate virulence and colonization factors in Streptococcus pneumoniae
title Mucins regulate virulence and colonization factors in Streptococcus pneumoniae
title_full Mucins regulate virulence and colonization factors in Streptococcus pneumoniae
title_fullStr Mucins regulate virulence and colonization factors in Streptococcus pneumoniae
title_full_unstemmed Mucins regulate virulence and colonization factors in Streptococcus pneumoniae
title_short Mucins regulate virulence and colonization factors in Streptococcus pneumoniae
title_sort mucins regulate virulence and colonization factors in streptococcus pneumoniae
url https://hdl.handle.net/1721.1/156937
work_keys_str_mv AT bathjaderose mucinsregulatevirulenceandcolonizationfactorsinstreptococcuspneumoniae