Differential expression of cytokine in kadaknath and commercial chicken against coccidial challenge

In the present investigation the relative expression of interleukins (IL)-1β, IL-2, IL-6, IL-17 and interferon (IFN)-Y genes were explored in response to coccidial challenge in Kadaknath (n=12), Cari-Vishal (n=12) and Cobb (n=12) broiler chicken using quantitative PCR. The intraepithelial lymphocytes cell of control, T₁ and T₂ on 4, 7 and 14d post infection (pi) were used as templates for expression of five inflammatory cytokines. The relative mean fold expression for ILβ1 ranged from 9.91± 0.14 (Kadaknath) to 119.01±0.29 (Cobb). The highest and lowest relative mean fold expression for IL-2 was observed to be 242.19±0.40 and 6.25±0.03 in Cobb at d4 and d14 pi, respectively. For IL-6 gene, the lowest relative mean fold expression was observed in Kadaknath (8.11±0.05) while the highest value was recorded in Cobb (99.04±0.92). The relative mean fold expression for IL-17 was 11.04±0.29 in Kadaknath and 197.40±0.37 in Cobb. For IFN-Y gene, the lowest relative mean fold expression was observed in Kadaknath (8.11±0.19), while the highest value was recorded in Cobb (84.74±0.25). In Cobb and Cari-Vishal broilers most cytokines (IL-1β, IL-6, IL-17 and IFN-Y) were observed to be transcribed to higher levels than Kadaknath chicken. It is concluded that the differential expression of cytokine genes in three genetic groups showed different degree of mucosal immune response to Eimeria infection and it depend upon the genetic background/genotype of birds, coccidial dosage and age of infection.