Salmonella serovar-specific interaction with jejunal epithelial cells

Area of Science:

• * Microbiology and Immunology
• * Host-Pathogen Interactions
• * Gastrointestinal Health

Background:

• * The gut harbors diverse pathogens like Salmonella spp.
• * Pathogenicity of many Salmonella serotypes remains understudied in human and animal models.
• * Understanding Salmonella interactions with host immunity is crucial for animal and public health.

Purpose of the Study:

• * To investigate the invasion capabilities of environmental Salmonella strains in pig intestinal cells (IPEC-J2).
• * To assess the modulation of innate immunity by these Salmonella strains.
• * To identify potential biomarkers for Salmonella invasiveness.

Main Methods:

• * Utilized pig intestinal epithelial cells (IPEC-J2) as an in vitro model.
• * Analyzed gene expression of key immune mediators, including Interferon-beta (IFN-β), Interleukin-1 beta (IL-1β), Interleukin-8 (IL-8), and Tumor Necrosis Factor-alpha (TNF-α).
• * Investigated the role of the p38-MAPK pathway and the effect of IL-8 blockade on bacterial penetration.

Main Results:

• * Salmonella strains exhibited differential abilities to modulate innate immunity and invade IPEC-J2 cells.
• * IFN-β, IL-1β, and IL-8 gene expression were increased by certain strains, indicating inflammatory responses.
• * S. Typhimurium, S. Coeln, and S. Thompson showed higher invasion potential, up-regulating IL-8 and TNF-α; IL-8 blockade reduced S. Typhimurium penetration.
• * S. Diarizonae strain 1 demonstrated lower invasion and did not induce inflammation, down-regulating the p38-MAPK pathway.

Conclusions:

• * IPEC-J2 cells serve as a valuable model for studying host-gut pathogen interactions.
• * IL-8 and TNF-α gene expression can serve as predictive markers for Salmonella strain invasiveness in enterocytes.
• * Different Salmonella serotypes possess distinct mechanisms for interacting with the host innate immune system.