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Updated: Jul 7, 2026
Nucleofection and In Vivo Propagation of Chicken Eimeria Parasites
Published on: February 14, 2020
Immune-related gene expression in two B-complex disparate genetically inbred Fayoumi chicken lines following Eimeria
D K Kim1, H S Lillehoj, Y H Hong
1Animal Parasitic Diseases Laboratory, Animal and Natural Resources Institute, USDA, Beltsville, MD 20705, USA. Hyun.Lillehoj@ars.usda.gov
Abstract:
To investigate the influence of genetic differences in the MHC on susceptibility to avian coccidiosis, M5.1 and M15.2 B-haplotype-disparate Fayoumi chickens were orally infected with live Eimeria maxima oocysts, and BW gain, fecal oocyst production, and expression of 14 immune-related genes were determined as parameters of protective immunity. Weight loss was reduced and fecal parasite numbers were lower in birds of the M5.1 line compared with M15.2 line birds. Intestinal intraepithelial lymphocytes from M5.1 chickens expressed greater levels of transcripts encoding interferon-gamma (IFN-gamma), interleukin-1beta (IL-1beta), IL-6, IL-8, IL-12, IL-15, IL-17A, inducible nitric oxide synthase, and lipopolysaccharide-induced tumor necrosis factor-alpha factor and lower levels of mRNA for IFN-alpha, IL-10, IL-17D, NK-lysin, and tumor necrosis factor superfamily 15 compared with the M15.2 line. In the spleen, E. maxima infection was associated with greater expression levels of IFN-gamma, IL-15, and IL-8 and lower levels of IL-6, IL-17D, and IL-12 in M5.1 vs. M15.2 birds. These results suggest that genetic determinants within the chicken MHC influence resistance to E. maxima infection by controlling the local and systemic expression of immune-related cytokine and chemokine genes.
Insights
Genetic differences in the chicken Major Histocompatibility Complex (MHC) influence avian coccidiosis resistance. Chickens with specific MHC haplotypes showed reduced weight loss and parasite load, indicating enhanced immune protection against Eimeria maxima.
Area of Science:
- Immunology
- Avian Genetics
- Parasitology
Background:
- Avian coccidiosis, caused by Eimeria parasites, poses a significant threat to poultry health and productivity.
- The Major Histocompatibility Complex (MHC) plays a crucial role in immune responses and disease resistance in various species.
- Understanding the genetic basis of resistance is vital for developing effective control strategies in chickens.
Purpose of the Study:
- To investigate the impact of genetic variations within the chicken MHC on susceptibility to avian coccidiosis.
- To determine how different MHC B-haplotypes affect immune gene expression and protective immunity against Eimeria maxima.
Main Methods:
- Oral infection of B-haplotype-disparate Fayoumi chickens (M5.1 and M15.2 lines) with live Eimeria maxima oocysts.
- Assessment of body weight gain and fecal oocyst production as indicators of resistance.
- Quantitative analysis of immune-related gene expression in intestinal intraepithelial lymphocytes and spleen.
Main Results:
- M5.1 line chickens exhibited reduced weight loss and lower fecal parasite counts compared to M15.2 line birds.
- Significant differences in the expression of key immune-related genes, including interferon-gamma (IFN-gamma) and various interleukins (ILs), were observed between the two lines.
- M5.1 chickens showed higher expression of pro-inflammatory genes (e.g., IFN-gamma, IL-1beta, IL-6, IL-8) and lower expression of immunosuppressive genes (e.g., IL-10, IL-17D) in the intestine.
Conclusions:
- Genetic determinants within the chicken MHC significantly influence resistance to Eimeria maxima infection.
- MHC-associated resistance is mediated by differential regulation of local and systemic immune-related cytokine and chemokine genes.
- These findings highlight the importance of MHC genetics in avian coccidiosis and suggest potential targets for breeding resistant poultry.
