Pneumococcal Phasevarions Control Multiple Virulence Traits, Including Vaccine Candidate Expression

Bibliographic Details
Title: Pneumococcal Phasevarions Control Multiple Virulence Traits, Including Vaccine Candidate Expression
Authors: Zachary N. Phillips, Claudia Trappetti, Annelies Van Den Bergh, Gael Martin, Ainslie Calcutt, Victoria Ozberk, Patrice Guillon, Manisha Pandey, Mark von Itzstein, W. Edward Swords, James C. Paton, Michael P. Jennings, John M. Atack
Source: Microbiology Spectrum, Vol 10, Iss 3 (2022)
Publisher Information: American Society for Microbiology, 2022.
Publication Year: 2022
Collection: LCC:Microbiology
Subject Terms: phasevarion, phase variation, Streptococcus pneumoniae, vaccine, epigenetic regulation, pneumococcus, Microbiology, QR1-502
More Details: ABSTRACT Streptococcus pneumoniae is the most common cause of bacterial illness worldwide. Current vaccines based on the polysaccharide capsule are only effective against a limited number of the >100 capsular serotypes. A universal vaccine based on conserved protein antigens requires a thorough understanding of gene expression in S. pneumoniae. All S. pneumoniae strains encode the SpnIII Restriction-Modification system. This system contains a phase-variable methyltransferase that switches specificity, and controls expression of multiple genes—a phasevarion. We examined the role of this phasevarion during pneumococcal pathobiology, and determined if phase variation resulted in differences in expression of currently investigated conserved protein antigens. Using locked strains that express a single methyltransferase specificity, we found differences in clinically relevant traits, including survival in blood, and adherence to and invasion of human cells. We also observed differences in expression of numerous proteinaceous vaccine candidates, which complicates selection of antigens for inclusion in a universal protein-based pneumococcal vaccine. This study will inform vaccine design against S. pneumoniae by ensuring only stably expressed candidates are included in a rationally designed vaccine. IMPORTANCE S. pneumoniae is the world’s foremost bacterial pathogen. S. pneumoniae encodes a phasevarion (phase-variable regulon), that results in differential expression of multiple genes. Previous work demonstrated that the pneumococcal SpnIII phasevarion switches between six different expression states, generating six unique phenotypic variants in a pneumococcal population. Here, we show that this phasevarion generates multiple phenotypic differences relevant to pathobiology. Importantly, expression of conserved protein antigens varies with phasevarion switching. As capsule expression, a major pneumococcal virulence factor, is also controlled by the phasevarion, our work will inform the selection of the best candidates to include in a rationally designed, universal pneumococcal vaccine.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 2165-0497
Relation: https://doaj.org/toc/2165-0497
DOI: 10.1128/spectrum.00916-22
Access URL: https://doaj.org/article/68f9c1ea19634bfb9653d1784a3d28cf
Accession Number: edsdoj.68f9c1ea19634bfb9653d1784a3d28cf
Database: Directory of Open Access Journals
More Details
ISSN:21650497
DOI:10.1128/spectrum.00916-22
Published in:Microbiology Spectrum
Language:English