pestis infection. Furthermore,

some of the identified genes and signaling pathways have been found to be essential for infection by other bacterial species. For example, the PI3K pathway is required for successful infection in Yersinia (this study), Listeria and Salmonella[13, 62]. Thus, the RNAi screen hits may represent candidate targets for development of host-derived therapeutics that inhibit not only Yersinia infection, but also potentially a wide range of bacterial pathogens that employ common virulence mechanisms. Methods Tissue culture cell growth conditions and chemicals The GloResponse™ NF-κB RE-luc2P-HEK293 cell line (Promega, Madison, Wisconsin), was cultured in DMEM (Invitrogen, Carlsbad, CA) supplemented with 10% FBS (HyClone, Logan, UT), 2 mM glutamine, 1 mM sodium pyruvate, and 50 μg ml-1 selleck Hygromycin B (HygB) (DMEM/10-HygB). For the transfection assays, host cells were maintained in antibiotic-free DMEM/10% FBS. THP-1 human monocytes (ATCC TIB-202) were maintained in RPMI-1640/10% FBS. Normal AZD5363 supplier human dendritic cells (NHDC) (LONZA, Allendale, NJ) were cultured in LGM-3 Growth Medium (LONZA). All media types do not contain any SCF, the natural ligand of c-KIT. All cell types were cultured

at 37°C and 5% CO2. Phenol-purified lipopolysaccharide (LPS) from E. coli 055:B5 (Sigma-Aldrich, St. Louis, MO) was used as a positive control to induce cytokine release by host cells. The inhibitors TBB, H-89, CKI-7, and BI-78D3 were purchased from Sigma-Aldrich.

OSI-930 was obtained from Selleck Chemicals (Houston, TX). Bacterial strains and growth conditions The following Yersinia strains were used in this study: Y. pestis medievalis Sirolimus manufacturer KIM5- (pCD1+, pgm-) [63], Y. pestis orientalis India195 (pCD1+, pgm+, LANL archive), Y. enterocolitica WA (pYV+, ATCC 27729), and Y. enterocolitica WA-01 (pYV-, this study). Strains were routinely propagated on brain heart infusion agar (Difco, Detroit, Mich) at 26°C overnight and up to 1 week storage at 4°C. For cell infection experiments, bacteria were grown at 26°C in brain heart infusion broth for 18 h in an orbital shaker at 180 rpm, followed by dilution of the bacterial culture to obtain 0.1 OD660 and additional growth for 2 h at 37°C (100 rpm). The pYV- Y. enterocolitica strain was obtained by serial passages of Y. enterocolitica WA on LB agar plates at 37°C. Bacterial clones were isolated and loss of pYV plasmid was monitored by PCR using primer sets for amplification of yopH and yopJ.