C5aR+ lysozyme-expressing dendritic cells (LysoDCs) comprise a unique cell population in the Peyer’s patch (PP) subepithelial dome (SED).
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PROVIDER: PRJNA577913 | ENA |
REPOSITORIES: ENA
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Project description:To define the ECF sigma sigV - regulated genes during log growth phase in LB media under induction conditions for sigV The seven extracytoplasmic function (ECF) sigma (σ) factors of Bacillus subtilis are broadly implicated in resistance to antibiotics and other cell envelope stressors mediated, in part, by regulation of cell envelope synthesis and modification enzymes. We here define the regulon of σV as including at least 20 operons many of which are also regulated by σM, σX, or σW. The σV regulon is strongly and specifically induced by lysozyme and this induction is key to the intrinsic resistance of B. subtilis to lysozyme. Strains with null mutations in either sigV or in all seven ECF σ factor genes (Δ7ECF) have essentially equal increases in sensitivity to lysozyme. Induction of σV in the Δ7ECF background restores lysozyme resistance, whereas induction of σM, σX or σW does not. Lysozyme resistance results from the ability of σV to activate the transcription of two operons: the autoregulated sigV-rsiV-oatA-yrhK operon and dltABCDE. Genetic analyses reveal that oatA and dlt are largely redundant with respect to lysozyme sensitivity: single mutants are not affected in lysozyme sensitivity whereas a double oatA dltA mutant is as sensitive as a sigV null strain. Moreover, the triple sigV oatA dltA mutant is no more sensitive than the oatA dltA double mutant, indicating that there are no other σV-dependent genes necessary for lysozyme resistance. Thus, σV confers lysozyme resistance by activation of two cell wall modification pathways: O-acetylation of peptidoglycan catalyzed by OatA and D-alanylation of teichoic acids by DltABCDE. Strains Δ7Pxyl-sigV + xylose vs. Δ7Pxyl-sigV - xylose, 168 + lysozyme vs. 168 - lysozyme. Each experiment was conducted 6 times using three independent total RNA preparations (biologlical triplicates). For each paired comparison, one sample was labeled with Alexa Fluor 555 and the other was with Alexa Fluor 647. For each comparison, three replicates were performed with dyeswap with the same RNA preparation.
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Project description:The mucosa is an ideal route for vaccination against pathogen infection, but the effective adjuvant capable of overcoming the tolerogenic dendritic cell (DC) environment is unavailable. We characterized type 2 conventional DCs and lysozyme-expressing monocyte-derived DCs (LysoDCs) of Peyer’s patches to identify the vaccination target cells through single-cell RNA sequencing. Based on functional analysis of the data, we suggest that C5aR+ LysoDCs and Co1 peptide, a C5aR ligand, as a target cell and an adjuvant, respectively, for mucosal vaccination. Co1-mediated stimulation of C5aR+ LysoDCs increased the level of reactive oxygen species, leading to CCL3-mediated chemotaxis and exogenous antigen cross-presentation, which elicited an antigen-specific CD8+ T cell response. In a SARS-CoV-2 vaccine model, Co1 peptide increased the frequency of antigen-specific polyfunctional CD8+ T cells in systemic as well as mucosal compartments. Collectively, LysoDC activation by Co1 peptide potentiates vaccination efficiency by constructing an immunostimulatory environment in the mucosal immune inductive site.
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