In studies conducted during 2014–2015, we performed epidemic surveillance of AIVs among wild birds at nature reserves in southern China, isolated two novel reassortant HPAI H5N6 viruses, and conducted genetic and phylogenetic analyses to elucidate their molecular features (Kang et al., 2017). By extension, in the present study, we investigated the pathogenicity and transmissibility of the viruses in chickens. In addition, to assess the role of the host innate immune response of H5N6-infected chickens, we examined a complex expression profile of pattern recognition receptors (PRRs), proinflammatory cytokines, chemokines, and MHC molecules in the brain, lung, spleen, and bursa of Fabricius.