Cellular aspects of immunity to intracellular Salmonella enterica

Salmonella enterica is a frequent gastrointestinal pathogen with ability to cause diseases ranging from local gastrointestinal inflammation and diarrhea to life-threatening typhoid fever. Salmonella is an invasive, facultative intracellular pathogen that infects various cell types of the host and can survive and proliferate in different populations of immune cells. During pathogenesis, Salmonella is confronted with various lines of immune defense. To successfully colonize host organisms, the pathogen deploys a set of sophisticated mechanisms of immune evasion and direct manipulation of immune cell functions. In addition to resistance against innate immune mechanisms, including the ability to avoid killing by macrophages and dendritic cells (DCs), Salmonella interferes with antigen presentation by DCs and the formation of an efficient adaptive immune response. In this review, we describe the current understanding of Salmonella virulence factors during intracellular life and focus on the recent advances in the understanding of interference of intracellular Salmonella with cellular functions of immune cells.