[Host defense mechanisms against Salmonella infection]

Salmonella is one of the gram negative intracellular pathogens. The immune response to Salmonella includes innate immunity and adaptive immunity. The intestinal epithelium, neutrophil, macrophage, dendritic cell, NK cell, NK T cell and gammadelta T cell take important part in former process, and antigen specific T cell and B cell take part in the later process. Macrophages and dendritic cells increase in number early after Salmonella infection and produce variety of cytokines. Especially, IL-12, IL-15 and IL-18 play important roles in protection against Salmonella infection, proliferation of NK cell, NKT cell and gammadelta T cell, producing IFN-gamma, in addition, IL-12 and IL-18 induce IFN-gamma production by Th1 cells and adaptive immune response.