The turkey, compared to the chicken, fails to mount an effective early immune response to Histomonas meleagridis in the gut

Abstract

Histomonosis is a disease of poultry caused by Histomonas meleagridis. Chickens usually recover while the mortality rate in turkeys is high. The immunological response of both species towards H. meleagridis was investigated. Parasites migrated in greater numbers to the turkey liver compared with that of chicken. Chicken mounted an effective caecal innate response, with increased expression of IL-1beta, CXCLi2 and IL-6 mRNA, resulting in control of parasite numbers. The turkey failed to mount such an effective innate response in the caecal tonsil, allowing greater numbers to migrate to the liver, where a sustained, uncontrolled immune response was mounted, evidenced by the upregulation of mRNA for IL-1beta, CXCLi2, IFN-gamma, IL-13, IL-4 and IL-10. Expression levels of mRNA of the chicken and turkey beta-defensin AvBD2 suggest that this response was not limited to the cytokines. There was an influx of CD4+, CD8alpha+, CD28+ and CD44+ cells into the livers of both species, coinciding with parasite movement. These influxes were more pronounced in the turkey, correlating with a decrease in numbers of the same cells in the spleen, which was not observed in the chicken. Antibody levels in the chicken increased more than those in the turkey, supporting evidence of an adaptive response.

Avian metapneumovirus infection of chicken and turkey tracheal organ cultures: comparison of virus–host interactions

“…The following cycle profile was applied: one cycle at 45°C for 10 min, one cycle at 95°C for 10 min, and 40 cycles at 95°C for 15 s and 57°C for 45 s. The results are displayed in threshold cycle values (Ct). Ct values were normalized based on the detection of 28S rRNA expression levels (Powell et al, 2009). The data are presented as fold change in mRNA expression levels in relation to ΔCt values from aMPV-free control groups (Pfaffl, 2001).…”

The long view: a bright past, a brighter future? Forty years of chicken immunology pre- and post-genome

“…IgE production is driven by IL-5, after IL-4 induces isotype switching to IgE. In the chicken, IL-13 and IL-4 (the former up to 100-fold more than the latter) are both induced following infection with extracellular pathogens (Degen et al, 2005;Powell et al, 2009), but IL-5 expression is switched off (Powell et al, 2009). IgE is not produced in birds*chickens only have IgM, IgY (the functional equivalent of mammalian IgG), which does not have sub-types, and IgA.…”

Chlamydophila psittaci Zoonotic Risk Assessment in a Chicken and Turkey Slaughterhouse

“…This may explain why the infection rates in the turkey flocks examined were indeed higher than the ones found in the broiler chicken flocks and why individual turkeys revealed higher mean culture scores than individual chickens. Powell et al found that the innate immunity in turkeys was less potent than that in chickens, resulting in a higher disease burden for Histomonas meleagridis (12). However, the higher bacterial loads in turkeys could also be explained by the occurrence of more virulent ompA genotypes and/or by the presence of mixed infections in turkeys.…”