Cytokine Expression in Chicken Peripheral Blood Mononuclear Cells after In Vitro Exposure to Salmonella enterica serovar Enteritidis

Abstract

Cytokines are secreted proteins involved with cell recruitment and regulation of both innate and adaptive immune responses. They are essential for an effective host immune response to pathogens. The objective of this study was to determine the effect of Salmonella enterica serovar Enteritidis (S. Enteritidis) exposure and genetic line on cytokine mRNA expression level of cultured chicken peripheral blood mononuclear cells (PBMC). Interleukin-2, interleukin-6 (IL-6), CXCLi2, and transforming growth factor-β4 (TGF-B4) messenger ribonucleic acid expression was measured by quantitative reverse transcription-PCR assays in PBMC from 3 chicken lines (broiler, Leghorn, Fayoumi) after in vitro exposure to S. Enteritidis. The PBMC were isolated from uninfected birds and cultured overnight. The next day, live pathogenic S. Enteritidis was added to half of the cultures. All cultures were harvested after 2 or 4 h of exposure. Exposure to S. Enteritidis downregulated IL-6, CXCLi2, and TGF-β4 but not interleukin-2 mRNA expression. No significant genetic line or exposure time effects were detected. These findings demonstrate that exposure of chicken PBMC to S. Enteritidis can induce a rapid change in both proinflammatory (IL-6, CXCLi2) and antiinflammatory (TGF-β4) cytokine gene expression.