analysis of interactions of salmonella type three secretion mutants with 3-d intestinal epithelial cells沙门氏菌的相互作用类型的分析三个突变体分泌3 d肠道上皮细胞.pdfVIP

Analysis of Interactions of Salmonella Type Three Secretion Mutants with 3-D Intestinal Epithelial Cells 1 1,2 1 1 Andrea L. Radtke , James W. Wilson , Shameema Sarker , Cheryl A. Nickerson * 1 School of Life Sciences, Center for Infectious Diseases and Vaccinology, The Biodesign Institute at Arizona State University, Tempe, Arizona, United States of America, 2 Department of Biology, Villanova University, Villanova, Pennsylvania, United States of America Abstract The prevailing paradigm of Salmonella enteropathogenesis based on monolayers asserts that Salmonella pathogenicity island-1 Type Three Secretion System (SPI-1 T3SS) is required for bacterial invasion into intestinal epithelium. However, little is known about the role of SPI-1 in mediating gastrointestinal disease in humans. Recently, SPI-1 deficient nontyphoidal Salmonella strains were isolated from infected humans and animals, indicating that SPI-1 is not required to cause enteropathogenesis and demonstrating the need for more in vivo-like models. Here, we utilized a previously characterized 3-D organotypic model of human intestinal epithelium to elucidate the role of all characterized Salmonella enterica T3SSs. Similar to in vivo reports, the Salmonella SPI-1 T3SS was not required to invade 3-D intestinal cells. Additionally, Salmonella strains carrying single (SPI-1 or SPI-2), double (SPI-1/2) and complete T3SS knockout (SPI-1/SPI-2: flhDC) also invaded 3-D intestinal cells to wildtype levels. Invasion of wildtype and TTSS mutants was a Salmonella active process, whereas non- invasive bacterial strains, bacterial size beads, and heat-killed Salmonella did not invade 3-D cells. Wildtype and T3SS mutants d