Dynamic Changes in the Intraepithelial Lymphocyte Numbers Following Salmonella Typhimurium Infection in Broiler...

Area of Science:

• Poultry immunology
• Avian pathology
• Gut microbiology

Background:

• Salmonella Typhimurium is a significant pathogen in poultry.
• Intestinal intraepithelial lymphocytes (IELs) are crucial for gut immunity.

Purpose of the Study:

• To investigate the impact of Salmonella Typhimurium infection on broiler growth and immune responses.
• To characterize changes in IEL populations and cytokine expression post-infection.

Main Methods:

• Broiler chickens were infected with Salmonella Typhimurium.
• Body weight gain was monitored.
• IELs and spleen lymphocytes were analyzed using flow cytometry.
• Cytokine gene expression (IFN-γ, IL-1β, TNF-α) was assessed.

Main Results:

• A transient reduction in body weight gain was observed at 2 days post-infection.
• No significant changes in key pro-inflammatory cytokine gene expression were detected in the ileum.
• A significant increase in ileal IELs, including regulatory populations, occurred at 2 and 7 days post-infection.
• Spleen lymphocyte populations remained unchanged.

Conclusions:

• Salmonella Typhimurium infection transiently affects broiler growth.
• The increase in IELs, particularly regulatory subsets, suggests their involvement in managing intestinal inflammation during early infection.
• IELs may play a key role in the host's early defense and immune modulation against Salmonella.