Segatella copri Outer-Membrane Vesicles Are Internalized by Human Macrophages and Promote a Pro-Inflammatory Profile

Area of Science:

• Microbiology
• Immunology
• Gut Microbiota Research

Background:

• Increased abundance of Segatella copri (S. copri) is linked to systemic inflammatory diseases.
• Outer-membrane vesicles (OMVs) mediate bacterial communication, but S. copri OMVs' immune effects are unknown.

Purpose of the Study:

• To investigate the impact of S. copri-derived OMVs on human macrophages in vitro.
• To determine if S. copri OMVs influence macrophage phenotype and cytokine secretion.

Main Methods:

• Utilized THP-1 and monocyte-derived macrophage models.
• Tracked S. copri-OMV uptake using confocal microscopy and flow cytometry.
• Analyzed macrophage phenotype and cytokine secretion via flow cytometry and ELISA.

Main Results:

• S. copri-OMVs were internalized by macrophages via macropinocytosis and clathrin-dependent pathways.
• S. copri-OMVs, unlike the bacteria, induced M1-like polarization in M0 and M2 macrophages.
• S. copri-OMVs stimulated significant pro-inflammatory cytokine release from M1 macrophages.

Conclusions:

• S. copri-OMVs play a key role in driving pro-inflammatory macrophage responses.
• These findings suggest S. copri-OMVs may contribute to the pathogenesis of systemic inflammatory diseases.