Assessment of bacteriophage-induced inflammatory mediators in Salmonella-infected chicken macrophage HD11 cells

Abstract

This study was designed to characterize the role of P22 in the intracellular survival and pro-inflammatory responses in Salmonella-infected chicken macrophage-like HD11 cells. The intracellular survival of Salmonella Typhimurium was evaluated in the presence or absence of P22 at 24 h postinfection (hpi). The production of inflammatory mediators, including nitric oxide (NO), IL-1β, IL-6, IL-8, and IL-10, was determined at 0 and 24 hpi by using ELISA kits. The survival rates of intracellular S. Typhimurium were effectively reduced to 8.1% in Salmonella-infected HD11 cells treated with P22 at 24 hpi. The secretion of NO, IL-6, IL-8, and IL-10 varied with infection period and bacteriophage treatment. The reduction of intracellular S. Typhimurium was highly correlated with the enhanced production of NO (r＝0.816, P<0.001). The results suggest that bacteriophage can be used to control the intracellular pathogens. This study would provide useful information on the bacteriophage-host interactions and open the door for designing an effective and safe bacteriophage therapeutic system.