%0 Journal Article
%T SPI-1 encoded genes of Salmonella Typhimurium influence differential polarization of porcine alveolar macrophages in vitro
%A Kamila Kyrova
%A Hana Stepanova
%A Ivan Rychlik
%A Martin Faldyna
%A Jiri Volf
%J BMC Veterinary Research
%D 2012
%I BioMed Central
%R 10.1186/1746-6148-8-115
%X To test this ability in Salmonella enterica serovar Typhimurium, we infected porcine alveolar macrophages with wild-type Salmonella Typhimurium and its isogenic mutants devoid of two major pathogenicity islands, SPI-1 and SPI-2. The induction of genes linked with M1 or M2 polarization was determined by quantification of gene expression by RT-qPCR. The ĶĪSPI-1 mutant induced a high, dose-dependent M1 response but a low M2 response in infected macrophages. On the other hand, wild-type Salmonella Typhimurium induced a low M1 response but a high, dose-dependent M2 response in infected macrophages. The response to ĶĪSPI-2 mutant infection was virtually the same as the wild-type strain.We therefore propose that Salmonella Typhimurium DT104 studied here can polarize macrophages towards the less bactericidal M2 phenotype and that this polarization is dependent on the type III secretion system encoded by SPI-1.Salmonella enterica serovar Typhimurium (Salmonella Typhimurium) is a facultative, intracellular pathogen capable of causing severe gastroenteritis in mammals including humans. Although the virulence of Salmonella Typhimurium is a multifactorial phenotype, there are two key virulence determinants specific for S. enterica. To successfully interact with the immune system of the host, S. enterica is equipped with two type three secretion systems (T3SS-1 and T3SS-2) encoded by Salmonella pathogenicity island 1 (SPI-1) and Salmonella pathogenicity island 2 (SPI-2), respectively. These secretion systems evolved to deliver S. enterica proteins directly into the cytoplasm of the host cells. T3SS-1 translocates S. enterica proteins across the cytoplasmic membrane and promotes S. enterica invasion into non-phagocytic cells [1,2]. T3SS-2 translocates Salmonella proteins into the cytoplasm of the host cell across the phagosome membrane and is essential for Salmonella survival and replication inside professional phagocytic cells [3].Macrophages represent the key cells of host defense
%U http://www.biomedcentral.com/1746-6148/8/115