The engagement of TLRs by influenza virus in specific target tissues initiated animal immunity via the production of proinflammatory cytokines and chemokines, including IL-1β, IL-6, IL-8, IL-10, TNF-α, and CCL5. As shown in Figures 4A,B,D, the expression level of IL-1β, IL-6, and IL-10 were remarkably unregulated in the lungs of tested chickens when infected by SW8 and ZH283 compared to those of mock-infected chickens. On the contrary, in the brain, spleen, and bursa of Fabricius, the expression levels of IL-1β, IL-6, and IL-10 were downregulated when induced by both viruses. However, the expression levels of IL-8, TNF-α, and CCL5 in the tested tissues of infected chickens showed a different expression patterns. As illustrated in Figure 4F, ZH283 induced an upregulated expression level of CCL5 in all tested tissues, whereas SW8 induced an upregulated expression level of CCL5 in the brain and spleen, but a downregulated one in the lung and bursa of Fabricius. Notably, ZH283-induced expression levels of IL-1β, IL-8, TNF-α, IL-6, and IL-10 were greater than those induced by SW8 in all tested tissues of chickens (Figures 4A–E).