Leptospira interrogans binds to human cell surface receptors including proteoglycans

Area of Science:

• Microbiology
• Pathogenesis
• Infectious Diseases

Background:

• Leptospirosis is a significant global health issue, especially in tropical regions.
• The pathogenic mechanisms of Leptospira, the bacteria causing leptospirosis, are not fully understood.
• Previous research highlighted Leptospira's interaction with the extracellular matrix (ECM).

Purpose of the Study:

• To investigate the interactions between Leptospira interrogans and mammalian cells.
• To identify specific bacterial binding targets on host cells.
• To explore the role of these interactions in disease development and transmission.

Main Methods:

• Examined the binding of Leptospira interrogans to mammalian cells and ECM components.
• Investigated the role of glycosaminoglycans (GAGs) and proteoglycans (PGs) in bacterial attachment.
• Assessed the impact of inhibiting GAG/PG-mediated attachment on bacterial binding.

Main Results:

• Leptospira interrogans exhibited higher binding efficiency to mammalian cells compared to the ECM.
• A significant portion of cell-binding activity was mediated by attachment to GAG chains of PGs.
• Chondroitin sulfate B PGs were identified as primary attachment targets, while heparan sulfate PGs were less important.
• Inhibiting GAG/PG attachment partially reduced overall bacterial attachment, indicating other receptors exist.

Conclusions:

• Leptospira interrogans binding to mammalian cell GAGs, especially chondroitin sulfate B PGs, is a key interaction.
• This GAG binding may contribute to leptospirosis pathogenesis by targeting bacteria to host tissues like the kidneys.
• GAG binding could also facilitate environmental transmission of Leptospira through urine.