Lipopolysaccharide impairs mucin secretion and stimulated mucosal immune stress response in respiratory tract of neonatal chicks

The chicken immune system is immature at the time of hatching. The development of the respiratory immune system after hatching is vital to young chicks. The aim of this study was to investigate the effect of LPS on respiratory mucin and IgA production in chicks. In this study, we selected 7 days old AA broilers of similar weigh randomly; LPS atomized at 1 mg/kg body weigh dose in the confined space of 1 cubic meter. The chickens exposed for 2 h. Then collect samples after 4 h and 8 h respectively. Compared to control, LPS inhibited mucus production in BALF, caused a rising trend of the concentration of IgA in serum and BALF, and increased the protein expression of IgA in lung tissue. And LPS treat induced a decreasing trend of the mRNA expression of IL-6 and TGF-beta and significantly decreased the gene expression of TGF-alpha and EGFR after 4 h. After 8 h the LPS suppressed the TGF-beta mRNA expression significantly. In addition, LPS treatment stimulated airway epithelial cilia sparse after 4 h. Therefore, results proved: LPS can impair mucin expression and stimulated mucosal immune stress reaction of respiratory tract. This study suggested that LPS involved in respiratory tract mucosal immune response in chicks by regulating gene expression of cytokines and epithelial growth factors.