Production of Reactive Oxygen (ROS) and Nitrogen (RNS) Species in Macrophages J774A.1 Activated by the Interaction...

Area of Science:

• Immunology
• Microbiology
• Cell Biology

Background:

• Probiotics combat infectious pathogens like Escherichia coli (E. coli) via antimicrobial compounds and immunomodulation.
• This protective effect extends to both live probiotics and their inactive forms (paraprobiotics).
• Macrophages, crucial immune cells, are activated by microbial components, influencing immune responses.

Purpose of the Study:

• To evaluate the immunomodulatory effects of two probiotic strains, Escherichia coli Nissle 1917 and Bifidobacterium animalis subsp. lactis HN019, on macrophage activation.
• To assess these effects when macrophages are challenged with pathogenic E. coli strains.
• To compare the impact of different probiotic preparations (immunobiotic, paraprobiotic, postbiotic) and E. coli pathotypes.

Main Methods:

• Utilized the macrophage cell line J774A.1.
• Challenged macrophages with pathogenic E. coli strains.
• Quantified macrophage activation by measuring reactive oxygen species (ROS) and reactive nitrogen species (RNS) using flow cytometry.

Main Results:

• Both probiotic strains demonstrated a clear immunomodulatory effect on macrophages.
• Macrophage activation varied based on the probiotic preparation type and the specific E. coli strain used for challenge.
• A higher production of ROS compared to RNS was observed in activated macrophages.

Conclusions:

• Probiotic bacteria, in both live and inactive forms, effectively modulate macrophage immune responses.
• These findings support the role of probiotics in enhancing host defense against E. coli infections.
• The study underscores the differential impact of probiotics and pathogens on macrophage activation, with a notable preference for ROS production.