Propionic acid regulates immune tolerant properties in B Cells.

Area of Science:

• Immunology
• Molecular Biology

Background:

• Interleukin 10 (IL-10)-producing B cells (B10 cells) regulate immune responses.
• The posttranscriptional regulation of IL-10 in B10 cells remains incompletely understood.
• Short-chain fatty acids (SCFAs) are known modulators of immune cell function.

Purpose of the Study:

• To investigate the role of propionic acid (PA), an SCFA, in regulating IL-10 expression within B10 cells.
• To explore the association between PA levels and food allergy (FA).

Main Methods:

• Enzyme-linked immunosorbent assay (ELISA) and flow cytometry were used to analyze serum and cellular components from FA patients and healthy subjects.
• Investigated the impact of B cell activation with CpG on IL-10 and tristetretrprolin (TTP) production.
• Assessed the effect of PA on IL-10 mRNA stability and its role in experimental FA models in mice.

Main Results:

• Serum PA levels were lower in FA patients and negatively correlated with Th2 cytokines, specific IgE, and skin prick test results.
• Peripheral B10 cell frequency and IL-10 production were associated with serum PA concentrations.
• PA stabilized IL-10 mRNA in B cells, potentially by influencing granzyme B-mediated degradation, and attenuated FA responses in mice.

Conclusions:

• Propionic acid is essential for stabilizing IL-10 mRNA expression in B10 cells.
• PA administration demonstrates potential in mitigating experimental food allergy by preserving B10 cell homeostasis and function.