Expression and Characterization of Toll-Like Receptors and Other Immune Genes in the Adult Guinea Fowl Using Transcriptome Analysis
This research aims to shed more light on the immune response of avians to pathogens as well as provide a repertoire of genetic information that will further poultry research. Thirty-six one day-old GF keets divided into 2 groups (MV and St-V) and assigned battery cages from 0 to 8 weeks of age (WOA). At week 3, ‘St-V’ was immunized by administering a 1:1 ratio of 0.25 ml suspension of heat-killed Salmonella Typhimurium (hkst) with complete Freund’s adjuvant while MV group was immunized without hkst. Serum IgY was confirmed with modified indirect ELISA assay 48 hours after they were given a booster immunization (hkst + incomplete Freund’s adjuvant), 5 weeks after the primary immunization. Total RNA from the spleen, bursa, bone marrow and thymus was extracted using phenol-chloroform technique and TLR 15 gene expression was performed using qPCR. GAPDH was internal control. Fold change (2 -ΔΔ Ct) between MV and St-V showed TLR15 was downregulated in all the tissues, though not statistically significant (α = 0.05) in the thymus and bone marrow. Transcriptome analysis of differentially expressed genes in the bursa, between both MV and St-V groups yielded 902 differentially expressed contigs. Pathway analysis revealed 35 activated and 5 suppressed pathways. In conclusion, toll-like receptors play a role in immune response and their activity is modulated by the host organism, tissue, nature and time post infection. At 8 WOA, the avian bursa plays an active role in disease resistance in some avian species. HKST vaccine was able to elicit a strong response as indicated by the change in serum IgY levels compared to control. Also, HKST was able to activate a large number of regulatory pathways in the bursa, most concerned with immune function. Receptors like Epidermal growth factor receptor (EGFR) that play a role in innate immune signaling in the human skin were activated in the avian bursa suggesting that they may play a similar role in the bird.
Gabriel Oluwamuyiwa Akerele,
"Expression and Characterization of Toll-Like Receptors and Other Immune Genes in the Adult Guinea Fowl Using Transcriptome Analysis"
ETD Collection for Tennessee State University.