Submitted to: Veterinary Immunology and Immunopathology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/6/2008
Publication Date: 10/31/2008
Citation: Swaggerty, C.L., Pevzner, I.Y., Kaiser, P., Kogut, M.H. 2008. Profiling pro-inflammatory cytokine and chemokine mRNA expression levels as a novel method for selection of increased innate immune responsiveness. Veterinary Immunology and Immunopathology. 126(1-2):35-42. Interpretive Summary: Previous studies in our laboratory have shown that the rooster (male chickens) is important in determining how the white blood cells function and what types of chemical messengers they produce to help fight off infections. Since the innate immune response is the primary means young chickens have to protect themselves and fight infections, we hypothesize utilizing a novel genetics approach to identify roosters based on elevated production of chemical messengers called cytokines and chemokines. By identifying roosters with increased chemical messenger levels, we expect the offspring of these roosters will also have elevated levels of the chemical messengers. The objectives of this study were to employ a new genomics approach to identify “high” and “low” roosters within a population of chickens and then use select roosters to produce offspring. We characterized the pro-inflammatory chemical messengers (interleukin [IL]-1beta, IL-6, CXCLi2, and CCLi2) of 119 roosters and identified two populations with naturally high and low levels of the chemical messengers. Select high and low roosters were used to produce offspring for the second phase of the selection trial. Blood samples were collected from 214 offspring and the chemical messenger levels were evaluated. We found offspring produced from high roosters had significantly (P less than or equal to 0.02) higher chemical messenger levels compared to offspring from low roosters. We have identified a population of roosters with higher and lower than average pro-inflammatory chemical messenger levels and used the selected high and low roosters to produce offspring with similar chemical messenger profiles. This knowledge provides the poultry industry a novel method to select chickens that are healthier and therefore will likely help produce a chicken that is safer for the nations food supply.
Technical Abstract: Previous studies using F1 reciprocal crosses and two parental lines of broilers show the sire is instrumental in determining the in vitro leukocyte function and cytokine/chemokine profile. Since the innate immune response is the primary means a young chicken has to protect themselves, we hypothesize utilizing a novel genomics approach to select sires based on an elevated pro-inflammatory cytokine and chemokine profile. By identifying sires with increased pro-inflammatory cytokine and chemokine mRNA expression levels, we expect the progeny will also have elevated profiles. The objectives of this study were to employ a functional genomics approach to identify “high” and “low” sires within a broiler population using quantitative real-time RT-PCR (qRT-PCR) and then use select sires to produce progeny. We characterized the pro-inflammatory cytokine (interleukin [IL]-1beta and IL-6) and chemokine (CXCLi2 and CCLi2) profile of 119 sires and identified two populations with inherently high and low mRNA expression levels of select pro-inflammatory cytokines and chemokines. Select high and low sires were used to produce progeny for the second phase of the selection trial. Blood samples were collected from 214 progeny and the cytokine and chemokine mRNA expression levels determined by qRT-PCR. Progeny from high sires had significantly (P less than or equal to 0.02) higher cytokine (IL-1beta and IL-6) and chemokine (CXCLi2 and CCLi2) mRNA expression levels compared to progeny from low sires. We have identified a broiler population of sires with higher and lower than average pro-inflammatory cytokine/chemokine mRNA expression levels and used the selected high and low sires to produce progeny with similar cytokine/chemokine profiles.