Since accumulation of YopJ/P in host cells upon Yersinia infection has been previously linked to cell death via activation Selleck Natural Product Library of apoptotic pathways, we assessed cell viability at various MOIs. We registered no decrease in cell viability in drug-free cells or cells treated with the JNK1 inhibitor, even after 20 h post-infection of THP-1 cells with virulent Y.entorocolitica at MOI 2 of the assay. (data not shown) Taken together, these findings Veliparib mw indicate that c-KIT function is exploited

by Yersinia T3SS to suppress production of key transcription factors and cytokines involved in the regulation of the host immune response. Figure 5 c-KIT signaling is targeted by Yersinia T3SS to suppress pro-inflammatory immune response. (A) THP1 cells were pre-treated with 1 μM OSI-930 or 1 μM BI-78D3 for 18 h or untreated prior to infection with Y. enterocolitica (pYV+)

and Y. enterocolitica (pYV-) at MOI 2. The RNA levels are presented as fold change versus untreated THP1. Data is shown from three independent infection experiments performed in duplicate. A ‘*” denotes that relative RNA levels were significantly different (p<0.05) in OSI930-treated cells compared to untreated or BI-78D3-treated cells. (B) THP-1 cells were transfected with 50 nM siRNA targeting c-KIT or control (si-CTL) and incubated for 48 h. RNA levels are presented relative to transcript levels in siRNA-treated versus untreated THP-1. Data is shown from two representative experiments. A ‘*” denotes that relative FRAX597 ic50 RNA levels were significantly different (p<0.05) in si-cKIT-treated cells compared to si-CTL-treated cells. (C) THP-1 cells were transfected with 50 nM siRNA against c-KIT (si-cKIT) or control (si-CTL) siRNA and incubated for 72 h prior to infection with Y. enterocolitica

Tyrosine-protein kinase BLK WA at MOI 2 for 1 h. Gene transcript levels are depicted as a relative ratio to uninfected siRNA-treated THP-1 cells. Data is shown from three independent experiments performed in duplicate. A ‘*” denotes that relative RNA levels of immune genes were significantly different (p<0.05) in si-cKIT-treated cells compared to si-CTL-treated cells. (D) THP-1 cells, untreated or pretreated with 1μM OSI-930 for 5 h, were infected with Y. enterocolitica WA at MOI 40 for 45 min. Cell nuclei were purified, labeled with mouse anti-NF-κB RelA, and analyzed by flow cytometry. (left panel) The mean channel fluorescence was used to determine the fold change of RelA in the nuclei of Yersinia-infected compared to untreated THP-1 cells (middle panel). The statistical data was derived from two independent experiments (right panel). Figure 6 Yersinia infection activates c-KIT tyrosine phosphorylation.