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Genetics, Structure, and Function of Group A Streptococcal Pili.
Masanobu Nakata1, Bernd Kreikemeyer2
1Department of Oral Microbiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan.
Frontiers in Microbiology
|February 26, 2021
Summary
Group A Streptococcus (GAS) pili are crucial for infection, acting as adhesins and aiding immune evasion. Their diverse structures and functions, including a harpoon mechanism, highlight their role in GAS pathogenesis and potential as vaccine targets.
Area of Science:
- Microbiology
- Immunology
- Pathogenesis
Background:
- Streptococcus pyogenes (Group A Streptococcus; GAS) is a significant human pathogen causing diverse infections.
- GAS possesses surface proteins, including M protein and pili, important for serotyping and pathogenesis.
- GAS pili, discovered in 2005, have been extensively studied for their genetic, structural, and functional roles.
Purpose of the Study:
- To review the current understanding of GAS pili.
- To explore the genetic and structural features of GAS pili.
- To elucidate the functional roles of GAS pili in host-pathogen interactions and pathogenesis.
Main Methods:
- Review of existing literature on GAS pili.
- Analysis of genetic features within the FCT region.
- Examination of structural components and assembly mechanisms of GAS pili.
Main Results:
- GAS pili are assembled via isopeptide bonds, conferring protease resistance.
- Pili exhibit diverse functions, including adhesion to host tissues and biofilm formation.
- A minor pilin subunit mediates a 'harpoon' function, forming covalent bonds with host ligands.
- Pilus expression and function are linked to tissue tropism and immune evasion.
Conclusions:
- GAS pili play multifaceted roles in infection, from initial adhesion to immune system evasion.
- The structural diversity and unique functions of GAS pili are critical for GAS pathogenesis.
- GAS pili represent promising candidates for vaccine development against GAS infections.
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