Effect of Bacillus Subtilis on Immune Function of Hd11 Chicken Macrophages

ABSTRACT Poultry is frequently contaminated by Salmonella, a pathogen leading to human health concern worldwide. This study aimed to evaluate the effect of Bacillus subtilis (BS)strain 048 (BS048) on the activation, phagocytosis, sterilization, cytokine secretion, and nitrogen oxide synthesis of HD11 chicken macrophages subjected to Salmonella enteritidis challenge, using lipopolysaccharide treatment as a negative control. The results showed: (1) BS048 had no significant effect on extracellular lactate dehydrogenase activity (p>0.05), while lipopolysaccharide treatment significantly increased extracellular lactate dehydrogenase activity (p<0.05);(2)BS048 significantly upregulated the expression levels of pro-inflammatory cytokines (interleukin (IL)-1â and IL-6), anti-inflammatory cytokines(IL-10 and transforming growth factor-â1), and anti-viral cytokine, interferon-â (p<0.01); (3)BS048 significantly upregulated the mRNA expression level of the inducible nitric oxide synthase and its activity as well as extracellular nitrogen oxide level (p<0.01). In conclusion, BS048 could improve anti-inflammatory and immune functions of HD11 chicken macrophages, without cytotoxic effects on these cells.