Home > Research > Publications & Outputs > Bacterial surface lipoproteins mediate epitheli...

Electronic data

Links

Text available via DOI:

View graph of relations

Bacterial surface lipoproteins mediate epithelial microinvasion by Streptococcus pneumoniae

Research output: Contribution to Journal/MagazineJournal articlepeer-review

Published
  • Jia Mun Chan
  • Elisa Ramos-Sevillano
  • Modupeh Betts
  • Holly U. Wilson
  • Caroline Weight
  • Ambrine Houhou-Ousalah
  • Gabriele Pollara
  • Jeremy S. Brown
  • Robert S. Heyderman
Close
Article numbere00447-23
<mark>Journal publication date</mark>7/05/2024
<mark>Journal</mark>Infection and Immunity
Issue number5
Volume92
Publication StatusPublished
Early online date17/04/24
<mark>Original language</mark>English

Abstract

Streptococcus pneumoniae, a common colonizer of the upper respiratory tract, invades nasopharyngeal epithelial cells without causing disease in healthy participants of controlled human infection studies. We hypothesized that surface expression of pneumococcal lipoproteins, recognized by the innate immune receptor TLR2, mediates epithelial microinvasion. Mutation of lgt in serotype 4 (TIGR4) and serotype 6B (BHN418) pneumococcal strains abolishes the ability of the mutants to activate TLR2 signaling. Loss of lgt also led to the concomitant decrease in interferon signaling triggered by the bacterium. However, only BHN418 lgt::cm but not TIGR4 lgt::cm was significantly attenuated in epithelial adherence and microinvasion compared to their respective wild-type strains. To test the hypothesis that differential lipoprotein repertoires in TIGR4 and BHN418 lead to the intraspecies variation in epithelial microinvasion, we employed a motif-based genome analysis and identified an additional 525 a.a. lipoprotein (pneumococcal accessory lipoprotein A; palA) encoded by BHN418 that is absent in TIGR4. The gene encoding palA sits within a putative genetic island present in ~10% of global pneumococcal isolates. While palA was enriched in the carriage and otitis media pneumococcal strains, neither mutation nor overexpression of the gene encoding this lipoprotein significantly changed microinvasion patterns. In conclusion, mutation of lgt attenuates epithelial inflammatory responses during pneumococcal-epithelial interactions, with intraspecies variation in the effect on microinvasion. Differential lipoprotein repertoires encoded by the different strains do not explain these differences in microinvasion. Rather, we postulate that post-translational modifications of lipoproteins may account for the differences in microinvasion.