Project description:MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate gene expression by either translational inhibition or mRNA degradation. However, the role of miRNAs in inflammation induced by flagellin (ligand of TLR5) has not been fully determined, Here, we identified differentially expressed miRNAs in murine bone marrow-derived dendritic cells (BMDCs) between flagellin (FliC) treatment and medium alone using miRNA microarray. And we further evaluated the role of miRNAs in inflammation induced by flagellin.
Project description:How cellular checkpoints couple the orderly assembly of macromolecular machines with cell cycle progression is poorly understood. The alpha-proteobacterium Caulobacter crescentus assembles a single polar flagellum during each cell cycle. We discovered that expression of multiple flagellin transcripts is licensed by a translational checkpoint responsive to a dual input signal: a secretion-competent hook-basal-body (HBB) structure and a surge in the FlaF secretion chaperone during cytokinesis, instructed by the cell cycle circuitry. We find that the unorthodox FljJ flagellin, one of six flagellin paralogs, acts as checkpoint linchpin, binding both FlaF and the FlbT translational regulator. FljJ recruits FlbT to inhibit translation at the 5’ untranslated region in other flagellin transcripts before HBB assembly. Once FlaF is synthesized and stabilized, it directs FljJ secretion through the HBB, thereby separating FlbT from its co-activator and relieving translational inhibition. The FlbT/FlaF pair is wide-spread and functional properties are conserved in alpha-proteobacteria, including pathogens.
Project description:How cellular checkpoints couple the orderly assembly of macromolecular machines with cell cycle progression is poorly understood. The alpha-proteobacterium Caulobacter crescentus assembles a single polar flagellum during each cell cycle. We discovered that expression of multiple flagellin transcripts is licensed by a translational checkpoint responsive to a dual input signal: a secretion-competent hook-basal-body (HBB) structure and a surge in the FlaF secretion chaperone during cytokinesis, instructed by the cell cycle circuitry. We find that the unorthodox FljJ flagellin, one of six flagellin paralogs, acts as checkpoint linchpin, binding both FlaF and the FlbT translational regulator. FljJ recruits FlbT to inhibit translation at the 5’ untranslated region in other flagellin transcripts before HBB assembly. Once FlaF is synthesized and stabilized, it directs FljJ secretion through the HBB, thereby separating FlbT from its co-activator and relieving translational inhibition. The FlbT/FlaF pair is wide-spread and functional properties are conserved in alpha-proteobacteria, including pathogens.
Project description:The study aimed at defining the skin innate responses after intradermal injection of flagellin. For this purpose, pigs were immunized by intradermal route with flagellin and H1N1 antigen. Skin was then sampled for microarray analyses.
Project description:au-09-01_mpk_flagellin_edu - bak1bkk1 - Investigate flagellin mpk dependent genes by comparision between bak1bkk1 and col-0. Keywords: gene knock out
Project description:au16-02_dgk5 - transcriptome analysis of dgk5 mutant in response to flagellin - Is the dgk5.1 mutant impaired in its response to flagellin? - We compare seedlings grown in liquid medium treated or not with flagellin. Seedlings are either Col-0 or the mutant dgk5.
Project description:Macrophages are an important component of the innate immune system. Flagellin has been extensively studied for its adjuvant activity owing to its TLR5 and NLRC4 binding sites. However, few studies have comprehensively investigated the effects of flagellin in macrophages using transcriptome sequencing. In this study, RNA sequencing (RNA-seq) was used to analyze the expression patterns of RAW264.7 cells induced by flagellin (FliC) of Salmonella typhimurium compared with unstimulated cells, to identify novel transcriptomic signatures in macrophages.
Project description:Most Eukaryotes recognise flagellin as a signature of bacterial invasion. In contrast to animals, plants do not recognise flagellin proteins, but conserved peptides released from flagellin (Felix et al., 1999). However, these peptides (e.g. flg22) are folded and buried deeply inside the flagellin polymer and would need to be released before they can interact with cell surface receptors, such as FLS2 (Fliegman & Felix, 2016). Here we discovered that the hydrolytic pathway releasing the flagellin elicitor in plants is initiated by a host-secreted beta-galactosidase (BGAL), which removes the terminal modified viosamine (mVio) from the O-glycan that cloaks the flagellin polymer. BGAL contributes to flagellin-dependent immunity but only against bacterial Pseudomonas syringae strains that carry mVio. Signatures of arms races at this new level of antagonistic interactions are that BGAL is suppressed during infection by a heat stable metabolite secreted by bacteria, and that other P. syringae strains carry BGAL-insensitive O-glycans.