In Vitro Adhesion, Invasion, and Transcytosis of Streptococcus pneumoniae with Host Cells

Area of Science:

• Microbiology
• Pathogenesis
• Cell Biology

Background:

• Bacterial pathogenesis relies on host cell interactions, particularly for Streptococcus pneumoniae (Spn), which lacks secreted toxins.
• Spn adhesion and invasion are crucial for nasopharyngeal colonization and opportunistic infections.
• Understanding these interactions is key to explaining Spn biology and identifying therapeutic targets.

Purpose of the Study:

• To review the in vitro adhesion and invasion assay protocol for studying Spn-host cell interactions.
• To highlight how this assay can elucidate the molecular mechanisms underlying Spn virulence.
• To demonstrate the utility of this assay in discovering bacterial and host determinants of infection.

Main Methods:

• Utilizing in vitro adhesion and invasion assays.
• Employing various bacterial strains and host cell lines (epithelial, endothelial, immune cells).
• Analyzing bacterial attachment, host cell signaling, intracellular trafficking, and biofilm dispersal.

Main Results:

• Discovery of bacterial and host factors mediating Spn attachment.
• Identification of host signaling networks essential for bacterial endocytosis.
• Characterization of intracellular trafficking pathways subverted by Spn during disease progression.
• Elucidation of Spn's transition from biofilm to planktonic states for colonization and transmission.

Conclusions:

• In vitro adhesion and invasion assays are powerful tools for dissecting Spn virulence mechanisms.
• Modifications to bacterial strains and host cell lines enhance the understanding of Spn-host interactions.
• This assay approach provides insights into Spn pathogenesis, potentially leading to new intervention strategies.