Lactobacillus rhamnosus GG-Derived Soluble Mediators Modulate Adaptive Immune Cells

Area of Science:

• Immunology
• Microbiology
• Cell Biology

Background:

• Probiotics and nutritional interventions impact immune homeostasis and gut health.
• Lactobacillus rhamnosus GG (LGG) soluble mediators (LSM) show promise in preclinical models.
• Dendritic cell (DC) and T cell interactions are key in allergic disease tolerance.

Purpose of the Study:

• To investigate if LSM modulate DC maturation.
• To assess LSM's impact on T cell responses, including tolerogenic potential.
• To evaluate LSM's role in adaptive immunity.

Main Methods:

• Monocytes cultured with GM-CSF, IL-4, and LSM or control medium to differentiate into DCs.
• DCs matured with TNF-α and analyzed for phenotype.
• DCs co-cultured with autologous T cells to assess T cell activation and cytokine production (IFN-γ, IL-2, IL-10, IL-17A) and Foxp3+ expression.

Main Results:

• LSM did not alter DC numbers or maturation status.
• LSM-treated DCs enhanced T cell responses, increasing IL-2 and IFN-γ production upon recall antigen stimulation.
• Enhanced recall responses correlated with increased Foxp3+ expression, unlike with control DCs.

Conclusions:

• LSM modulate DC functionality, influencing adaptive immune responses.
• These findings support previous in vivo observations in animal models.
• LSM may serve as an alternative to live probiotics, pending further clinical validation.