Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Deglycosylation of eukaryotic-expressed flagellin restores adjuvanticity.

ABSTRACT: Flagellin, the TLR5 agonist, shows potent adjuvant activities in diverse vaccines and immunotherapies. Vibrio vulnificus flagellin B expressed in eukaryotic cells (eFlaB) could not stimulate TLR5 signaling. Enzymatic deglycosylation restored eFlaB's TLR5 stimulating functionality, suggesting that glycosylation interferes with eFlaB binding to TLR5. Site-directed mutagenesis of N-glycosylation residues restored TLR5 stimulation and adjuvanticity. Collectively, deglycosylated eFlaB may provide a built-in adjuvant platform for eukaryotic-expressed antigens and nucleic acid vaccines.

SUBMITTER: Khim K

PROVIDER: S-EPMC10522637 | biostudies-literature | 2023 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Deglycosylation of eukaryotic-expressed flagellin restores adjuvanticity.

Khim Koemchhoy K Puth Sao S Radhakrishnan Kamalakannan K Nguyen Tien Duc TD Lee Youn Suhk YS Jung Che-Hun CH Lee Shee Eun SE Rhee Joon Haeng JH

NPJ vaccines 20230926 1

Flagellin, the TLR5 agonist, shows potent adjuvant activities in diverse vaccines and immunotherapies. Vibrio vulnificus flagellin B expressed in eukaryotic cells (eFlaB) could not stimulate TLR5 signaling. Enzymatic deglycosylation restored eFlaB's TLR5 stimulating functionality, suggesting that glycosylation interferes with eFlaB binding to TLR5. Site-directed mutagenesis of N-glycosylation residues restored TLR5 stimulation and adjuvanticity. Collectively, deglycosylated eFlaB may provide a b ...[more]

PMID: 37752138

Similar Datasets

Re-annotated role of beta-Galactosidase in Flagellin deglycosylation

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.

2019-04-15 | PXD010461 | Pride

Amino acids 89-96 of Salmonella typhimurium flagellin represent the major domain responsible for TLR5-independent adjuvanticity in the humoral immune response.

Project description:Toll-like receptor 5 (TLR5) signaling in response to flagellin is dispensable for inducing humoral immunity, but alterations of aa 89-96, the TLR5 binding site, significantly reduced the adjuvanticity of flagellin. These observations indicate that the underlying mechanism remains incompletely understood. Here, we found that the native form of Salmonella typhimurium aa 89-96-mutant flagellin extracted from flagella retains some TLR5 recognition activity, indicating that aa 89-96 is the primary, but not the only site that imparts TLR5 activity. Additionally, this mutation impaired the production of IL-1β and IL-18. Using TLR5KO mice, we found that aa 89-96 is critical for the humoral adjuvant effect, but this effect was independent of TLR5 activation triggered by this region of flagellin. In summary, our findings suggest that aa 89-96 of flagellin is not only the crucial site responsible for TLR5 recognition, but is also important for humoral immune adjuvanticity through a TLR5-independent pathway.

| S-EPMC4579647 | biostudies-literature

Circular RNA is expressed across the eukaryotic tree of life.

Project description:An unexpectedly large fraction of genes in metazoans (human, mouse, zebrafish, worm, fruit fly) express high levels of circularized RNAs containing canonical exons. Here we report that circular RNA isoforms are found in diverse species whose most recent common ancestor existed more than one billion years ago: fungi (Schizosaccharomyces pombe and Saccharomyces cerevisiae), a plant (Arabidopsis thaliana), and protists (Plasmodium falciparum and Dictyostelium discoideum). For all species studied to date, including those in this report, only a small fraction of the theoretically possible circular RNA isoforms from a given gene are actually observed. Unlike metazoans, Arabidopsis, D. discoideum, P. falciparum, S. cerevisiae, and S. pombe have very short introns (∼ 100 nucleotides or shorter), yet they still produce circular RNAs. A minority of genes in S. pombe and P. falciparum have documented examples of canonical alternative splicing, making it unlikely that all circular RNAs are by-products of alternative splicing or 'piggyback' on signals used in alternative RNA processing. In S. pombe, the relative abundance of circular to linear transcript isoforms changed in a gene-specific pattern during nitrogen starvation. Circular RNA may be an ancient, conserved feature of eukaryotic gene expression programs.

| S-EPMC3946582 | biostudies-literature

flagellin

Project description:Flagellin diversity

| PRJEB47543 | ENA

Differentially-expressed genes in rice infected by Xanthomonas oryzae pv. oryzae relative to a flagellin-deficient mutant reveal potential functions of flagellin in host-pathogen interactions.

Project description:BackgroundPlants have evolved a sensitive defense response system that detects and recognizes various pathogen-associated molecular patterns (PAMPs) (e.g. flagellin) and induces immune responses to protect against invasion. Transcriptional responses in rice to PAMPs produced by Xanthomonas oryzae pv. oryzae (Xoo), the bacterial blight pathogen, have not yet been defined.ResultsWe characterized transcriptomic responses in rice inoculated with the wildtype (WT) Xoo and flagellin-deficient mutant ∆fliC through RNA-seq analysis. Digital gene expression (DGE) analysis based on Solexa/Illumina sequencing was used to investigate transcriptomic responses in 30 day-old seedlings of rice (Oryza sativa L. cv. Nipponbare). 1,680 genes were differentially-expressed (DEGs) in rice inoculated with WT relative to ∆fliC; among which 1,159 genes were up-regulated and 521 were down-regulated. Expression patterns of 12 randomly-selected DEGs assayed by quantitative real time PCR (qRT-PCR) were similar to those detected by DGE analyses, confirming reliability of the DGE data. Functional annotations revealed the up-regulated DEGs are involved in the cell wall, lipid and secondary metabolism, defense response and hormone signaling, whereas the down-regulated ones are associated with photosynthesis. Moreover, 57 and 21 specifically expressed genes were found after WT and ∆fliC treatments, respectively.ConclusionsDEGs were identified in rice inoculated with WT Xoo relative to ∆fliC. These genes were predicted to function in multiple biological processes, including the defense response and photosynthesis in rice. This study provided additional insights into molecular basis of rice response to bacterial infection and revealed potential functions of bacterial flagellin in the rice-Xoo interactions.

| S-EPMC4152760 | biostudies-literature

Correction: Circular RNA Is Expressed across the Eukaryotic Tree of Life

Project description: Not available

| S-EPMC3979859 | biostudies-literature

Dissociation of TRIF bias and adjuvanticity.

Project description:Toll-like receptors (TLRs), a family of "pattern recognition receptors," bind microbial and host-derived molecules, leading to intracellular signaling and proinflammatory gene expression. TLR4 is unique in that ligand-mediated activation requires the co-receptor myeloid differentiation 2 (MD2) to initiate two signaling cascades: the MyD88-dependent pathway is initiated at the cell membrane, and elicits rapid MAP kinase and NF-κB activation, while the TIR-domain containing adaptor inducing interferon-β (TRIF)-dependent pathway is initiated from TLR4-containing endosomes and results in IRF3 activation. Previous studies associated inflammation with the MyD88 pathway and adjuvanticity with the TRIF pathway. Gram-negative lipopolysaccharide (LPS) is a potent TLR4 agonist, and structurally related molecules signal through TLR4 to differing extents. Herein, we compared monophosphoryl lipid A (sMPL) and E6020, two synthetic, non-toxic LPS lipid A analogs used as vaccine adjuvants, for their capacities to activate TLR4-mediated innate immune responses and to enhance antibody production. In mouse macrophages, high dose sMPL activates MyD88-dependent signaling equivalently to E6020, while E6020 exhibits significantly more activation of the TRIF pathway (a "TRIF bias") than sMPL. Eritoran, a TLR4/MD2 antagonist, competitively inhibited sMPL more strongly than E6020. Despite these differences, sMPL and E6020 adjuvants enhanced antibody responses to comparable extents, with balanced immunoglobulin (Ig) isotypes in two immunization models. These data indicate that a TRIF bias is not necessarily predictive of superior adjuvanticity.

| S-EPMC7302928 | biostudies-literature

Structural Effect on Adjuvanticity of Saponins.

Project description:We have prepared a number of saponin-based vaccine adjuvant candidates. These unnatural saponins have a different terminal-functionalized side chain incorporated into the glucuronic acid unit that is attached to a triterpenoid core at its C3 position. The semisynthetic saponin adjuvants have shown significantly different immunostimulatory activities, suggesting that the structure of the side chain, triterpenoid core, and oligosaccharide domain together orchestrate saponin adjuvant's potentiation of immune responses. Among these new adjuvant candidates, VSA-2 (5b), a derivative of Momordica saponin (MS) II, showed consistent enhancement of immunoglobulin G2a (IgG2a) production when it was in formulation with either ovalbumin or recombinant hemagglutinin B (rHagB) antigen. With rHagB antigen, it induced a significantly higher IgG2a response than the positive control GPI-0100, a well-studied semisynthetic saponin adjuvant mixture derived from Quillaja saponaria Molina saponins, known for its ability to induce a balanced Th1/Th2 immunity. These results confirm that Momordica saponins are a viable natural source to provide potent saponin adjuvants after simple chemical derivatization and identify VSA-2 (5b) as another MS-based promising immunostimulant lead owing to its distinctive ability in potentiating the IgG2a response.

| S-EPMC8832471 | biostudies-literature

The minimal intrinsic stochasticity of constitutively expressed eukaryotic genes is sub-Poissonian.

Project description:Gene expression inherently gives rise to stochastic variation ("noise") in the production of gene products. Minimizing noise is crucial for ensuring reliable cellular functions. However, noise cannot be suppressed below a certain intrinsic limit. For constitutively expressed genes, this limit is typically assumed to be Poissonian noise, wherein the variance in mRNA numbers is equal to their mean. Here, we demonstrate that several cell division genes in fission yeast exhibit mRNA variances significantly below this limit. The reduced variance can be explained by a gene expression model incorporating multiple transcription and mRNA degradation steps. Notably, in this sub-Poissonian regime, distinct from Poissonian or super-Poissonian regimes, cytoplasmic noise is effectively suppressed through a higher mRNA export rate. Our findings redefine the lower limit of eukaryotic gene expression noise and uncover molecular requirements for achieving ultralow noise, which is expected to be important for vital cellular functions.

| S-EPMC10411910 | biostudies-literature

The minimal intrinsic stochasticity of constitutively expressed eukaryotic genes is sub-Poissonian.

Project description:Stochastic variation in gene products ("noise") is an inescapable by-product of gene expression. Noise must be minimized to allow for the reliable execution of cellular functions. However, noise cannot be suppressed beyond an intrinsic lower limit. For constitutively expressed genes, this limit is believed to be Poissonian, meaning that the variance in mRNA numbers cannot be lower than their mean. Here, we show that several cell division genes in fission yeast have mRNA variances significantly below this limit, which cannot be explained by the classical gene expression model for low-noise genes. Our analysis reveals that multiple steps in both transcription and mRNA degradation are essential to explain this sub-Poissonian variance. The sub-Poissonian regime differs qualitatively from previously characterized noise regimes, a hallmark being that cytoplasmic noise is reduced when the mRNA export rate increases. Our study re-defines the lower limit of eukaryotic gene expression noise and identifies molecular requirements for ultra-low noise which are expected to support essential cell functions.

| S-EPMC10028819 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data