Nf-Kb Pathway Genes Expression In Chicken Erythrocytes Infected With Avian Influenza Virus Subtype H9n2

1. Chicken erythrocytes in blood vessels are the most abundant circulating cells, which participate in the host's immune responses. The transcription factor nuclear factor-kappa B (NF-kappa B) plays a vital role in the inflammatory response following viral infections. However, the expression of the NF-kappa B pathway, and other immune-related genes in chicken erythrocytes infected with low pathogenic avian influenza virus (LPAIV H9N2), has not been extensively studied. 2. The following study determined the interaction of LPAIV H9N2 with chicken erythrocytes using indirect immunofluorescence microscopy. This was followed by investigating myeloid differentiation primary response 88 (MyD88), C-C motif chemokine ligand 5 (CCL5), melanoma differentiation-associated protein 5 (MDA5), the inhibitor of nuclear factor-kappa B kinase subunit epsilon (IKBKE), NF-kappa B inhibitor alpha (NFKBIA), NF-kappa B inhibitor epsilon (NFKBIE), interferon-alpha (IFN-alpha), colony-stimulating factor 3 (CSF3) and tumour necrosis factor receptor-associated factor 6 (TRAF6) by mRNA expression using quantitative real-time PCR (qRT-PCR) at four different time intervals (0, 2, 6 and 10 h). 3. There was a significant interaction between erythrocytes and LPAIV H9N2 virus. Furthermore, the mRNA expression of the NF-kappa B pathway and other immune-related genes were significantly up-regulated at 2 h post-infection in infected chicken erythrocytes, except for TRAF6, which were significantly downregulated. While at 0 h post-infection, IFN-alpha and CSF3 were significantly upregulated, whereas NFKBIA was significantly downregulated. Further expression of MDA5, CCL5 and NFKBIA was upregulated, while TRAF6 was downregulated at 6 h post-infection. In infected erythrocytes, expression of MyD88, CCL5 and IKBKE was upregulated. However, IFN-alpha and TRAF6 were downregulated at 10 h post-infection. 4. These results give initial evidence that the NF-kappa B pathway, and other genes related to immunity, in chicken erythrocytes may contribute to LPAIV subtype H9N2 and induce host immune responses.