Project description:Comparison of enriched membrane fractions of Francisella tularensis subsp. holarctica strain FSC200 and its DsbA mutant by SILAC analysis.
Project description:We demonstrated recently that both constitutive and FAS-triggered apoptosis of human neutrophils are profoundly impaired by Francisella tularensis, but how this is achieved is largely unknown. To test the hypothesis that changes in neutrophil gene expression contribute to this phenotype, we used human oligonucleotide microarrays to identify differentially regulated genes in cells infected with F. tularensis strain LVS compared with uninfected controls. In order to examine the effect of F. tularensis on the neutrophil transcriptome, we performed microarray expression analysis on human neutrophils treated with F. tularensis subsp. holarctica live vaccine strain (LVS).
Project description:Prior aerosol exposure to F. tularensis subsp. tularensis, but not the live attenuated strain (LVS) of F. tularensis subsp. holarctica or F. novicida, significantly antagonized the transcriptional response in the lungs of infected mice exposed to aerosolized TLR4 ligand E. coli LPS.
Project description:Secretion of outer membrane vesicles (OMV) presents an important phenomenon in Gram-negative bacteria and they play multiple roles in their lifestyle including virulence and host-pathogen interaction. Francisella tularensis secretes unusually shaped tubular OMV filled with immunoreactive material and virulence factors. Mice were immunized with OMV isolated from Francisella tularensis subsp. holarctica, fully virulent strain FSC200. Their sera were then used for detection of immunoreactive proteins.
Project description:We demonstrated recently that both constitutive and FAS-triggered apoptosis of human neutrophils are profoundly impaired by Francisella tularensis, but how this is achieved is largely unknown. To test the hypothesis that changes in neutrophil gene expression contribute to this phenotype, we used human oligonucleotide microarrays to identify differentially regulated genes in cells infected with F. tularensis strain LVS compared with uninfected controls. In order to examine the effect of F. tularensis on the neutrophil transcriptome, we performed microarray expression analysis on human neutrophils treated with F. tularensis subsp. holarctica live vaccine strain (LVS). Polymorphonuclear leukocytes (PMNs) were isolated from the blood of healthy donors. Control and F. tularensis-exposed PMNs were incubated at 37C for 0, 3, 6, 12, 24, and 48 hours.
Project description:The goal of this study is to determine the host response of human epithelial cells during infection with Francisella Tularensis. For this purpose, A549 human epithelial cell line was infected with Francisella tularensis spp. holarctica strain LVS for different times of infection, in duplicates. At different times post infection (0.5/1/3/6/12/24 hours post infection) cells were harvested and total RNA was extracted. RNA-seq libraries were constructed and sequencing of 100bp paired-end was performed on the Illumina NovaSeq 6000 system. Sequencing yielded about 22M reads per sample that were mapped to the human genome (Human: GRCh38) resulting with the identification of 21,066 transcripts. The expression of the infected samples was compared to mock sample, and RNA ratios were clustered using partitioning clustering. This approach allowed clustering of the cellular transcripts into 5 distinct classes based on similarities in temporal expression profiles. We next carried out GO term enrichment analysis for each of these five cluster. Our study represents the first detailed analysis of human epithelial response to Francisella tularensis infection, and provide a framework for comparative investigations of genes and mechanisms that may contribute to the infection.
