|Swaggerty, Christina - Christi|
|Kogut, Michael - Mike|
Submitted to: Immunology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/7/2004
Publication Date: 10/13/2004
Citation: Swaggerty, C.L., Kogut, M.H., Ferro, P.J., Rothwell, L., Pevzner, I.Y., Kaiser, P. 2004. Differential cytokine mRNA expression in heterophils isolated from Salmonella-resistant and -susceptible chickens. Immunology. 113:139-148. Interpretive Summary: During the first week of life, young chicks are likely to get infected with germs, like Salmonella, which can make people sick when they eat the infected chickens. Young chicks have special blood cells called heterophils that can help them prevent these infections. White blood cells can produce and release chemicals, called cytokines, which can kill Salmonella and other germs. The objective of this research was (1) to take heterophils from different types of young chicks (A, B, C and D) and look for different cytokines and (2) to take heterophils from the different types of young chicks and treat them with Salmonella to see which type of heterophils make the largest amount of cytokines. We found that heterophils from type A and D chickens made the most cytokines. These experiments are important to the commercial poultry breeders because we have shown that chickens can be selected for the ability to produce large amounts of cytokines which will allow them to be more resistant to Salmonella and other germs. A resistant chicken is going to be stronger and will fight off infections better; therefore, people are less likely to get sick from eating contaminated poultry.
Technical Abstract: We recently showed increased in vitro heterophil functional efficiency translates to increased in vivo resistance to a systemic Salmonella enteriditis (SE) infection utilizing a parental pair of broiler chickens (lines A and B) and the F1 reciprocal crosses (C and D). Heterophils produce cytokines and modulate acute protection against Salmonella in young poultry. Therefore, we hypothesize that heterophils from SE-resistant chickens (A and D) have the ability to produce an upregulated pro-inflammatory cytokine response compared to that of heterophils from SE-susceptible chickens (B and C). In this study, heterophils were isolated from day-old chickens, stimulated with various agonists (RPMI, SE, or SE opsonized with either normal chicken serum or immune serum against SE) and cytokine mRNA expression assessed using real-time quantitative RT-PCR. Heterophils from SE-resistant chickens (A and D) had significantly higher levels of pro-inflammatory cytokine (IL-6, IL-8, and IL-18) mRNA expression upon treatment with all stimulants compared to heterophils from SE-susceptible lines (B and C). Further, heterophils from SE-resistant chickens had significantly decreased mRNA expression levels of TGF-ß4, an anti-inflammatory cytokine, compared to heterophils from SE-susceptible chickens. These data indicate cytokine gene expression in heterophils may be a useful parameter in determining resistance to Salmonella, as indicated by our previous in vivo SE studies. Therefore, heterophil functional efficiency and cytokine production may be useful biomarkers for poultry breeders to consider when developing new immunocompetent lines of birds.