In vitro lipopolysaccharide treatment alters regulatory T cell properties in chickens

Area of Science:

• Immunology
• Cell Biology
• Veterinary Science

Background:

• Regulatory T cells (Tregs) play a crucial role in maintaining immune homeostasis.
• Toll-like receptors (TLRs) are key components of the innate immune system, recognizing pathogen-associated molecular patterns.
• Understanding avian immune responses is vital for poultry health and disease management.

Purpose of the Study:

• To investigate the in vitro effects of lipopolysaccharide (LPS) on chicken regulatory T cells (Tregs).
• To determine how LPS influences Treg function, including cytokine production and suppressive capacity.

Main Methods:

• Chicken Tregs were isolated and treated with varying concentrations of LPS (0 or 1 μg/ml) over time (0, 2, and 4 days).
• Quantitative real-time PCR was used to measure mRNA levels of TLRs, IL-2, and IL-10.
• Cell proliferation assays and functional suppression assays were performed.

Main Results:

• Tregs exhibited higher mRNA expression of TLR 2 and TLR 4 compared to CD4+CD25- cells.
• LPS treatment upregulated IL-2 mRNA at 2 and 4 days, and IL-10 mRNA at 4 days.
• LPS exposure led to increased Treg proliferation and initially abrogated, then enhanced, Treg suppressive function, resulting in supersuppression by day 4.

Conclusions:

• Chicken Tregs demonstrate dynamic functional changes in response to LPS stimulation.
• Early-stage LPS treatment promotes immune activation, while later stages induce potent immune suppression.
• These findings highlight the differential roles of Tregs in managing inflammation in chickens.