ARS | Publication request: Differential Cytokine Mrna Expression by Heterophils Isolated from Chickens That Vary in Their Susceptibility to Diverse Pathogens

Submitted to: Avian Immunology Research Group Abstract
Publication Acceptance Date: May 4, 2004
Publication Date: September 4, 2004
Citation: Swaggerty, C.L., Kogut, M.H., Ferro, P., Rothwell, L., Pevzner, I.Y., Kaiser, P. 2004. Differential Cytokine Mrna Expression By Heterophils Isolated From Chickens That Vary In Their Susceptibility To Diverse Pathogens [abstract]. 8th Avian Immunology Research Group Meeting. P. 22.

Technical Abstract: We recently showed that increased in vitro heterophil functional efficiency translates to increased in vivo resistance to bacterial (Salmonella enteritidis [gram-negative], Enterococcus gallinarum [gram-positive]) and parasitic infections (Eimeria tenella [coccidian parasite]) utilizing a pair of parental broiler lines, A and B. Heterophils produce cytokines and modulate acute protection against Salmonella in neonatal poultry. Therefore, we hypothesized that heterophils from resistant chickens (line A) have the ability to produce an upregulated pro-inflammatory cytokine response compared to heterophils from susceptible chickens (line B). In this study, heterophils were isolated from chickens 1, 14, and 28 days post-hatch and treated with either RPMI 1640 (control) or phagocytic agonists for 30 minutes at 39°C. Cytokine mRNA expression levels were then assessed using real-time quantitative RT-PCR. At all time points, heterophils from resistant chickens (line A) had significantly higher levels of pro-inflammatory cytokine (interleukin [IL]-6, IL-8, and IL-18) mRNA expression upon treatment with the phagocytic agonists compared to heterophils from susceptible chickens (line B). Further, heterophils from resistant chickens had significantly decreased mRNA expression levels of transforming growth factor (TGF)-beta4, an anti-inflammatory cytokine, when compared to heterophils from susceptible chickens. These data indicate that there is a relationship between the cytokine mRNA expression profiles generated by heterophils in determining the overall immune competence of chickens. Therefore, heterophil functional efficiency, accompanied by evaluating the cytokines produced by heterophils, may be useful biomarkers for poultry breeders to consider when developing new immunocompetent lines of birds.