PapRIV, a BV-2 microglial cell activating quorum sensing peptide

Area of Science:

• Microbiology
• Neuroscience
• Immunology

Background:

• Quorum sensing peptides (QSPs) are bacterial signaling molecules with potential host effects.
• The gut-brain axis links gut microbiota to microglial function.
• Microglia play a crucial role in brain immunity and function.

Purpose of the Study:

• To investigate the microglial activating properties of the QSP PapRIV from Bacillus cereus.
• To determine if PapRIV can cross the gastro-intestinal tract and blood-brain barrier.
• To explore PapRIV's role in gut-brain interactions.

Main Methods:

• In vitro studies using BV-2 microglia cells and Caco-2 cell models.
• In vivo assessment of peptide presence in mouse plasma.
• Analysis of cytokine (IL-6, TNFα) and ROS expression.
• NF-κB pathway activation assessment.
• Metabolite identification in serum.

Main Results:

• PapRIV demonstrated in vitro activation of BV-2 microglia cells.
• PapRIV successfully crossed the Caco-2 cell model and was detected in mouse plasma, indicating BBB penetration.
• PapRIV induced IL-6, TNFα, and ROS expression in a NF-κB dependent manner.
• A major active metabolite of PapRIV was identified in serum.

Conclusions:

• PapRIV can traverse the gastro-intestinal tract and blood-brain barrier.
• PapRIV exhibits microglia-activating properties in vitro.
• These findings suggest a potential role for PapRIV in modulating gut-brain axis communication and neuroinflammation.