Project description:The small intestine contains lymph node-like structures termed Peyer’s patches (PP). In adult mice they contain active germinal centers reminiscent of active crosstalk with microbiota. In neonatal mice, however, homeostatic immune activation does not take place. We wanted to test whether immune maturation in neonatal mice is stalled due to a reduced presence or function of antigen presenting mononuclear phagocytes (MNP). Thus we subjected PP MNP of postnatal day (PND) 11 and adult mice to scRNAseq in steady state or after immune activation with the TLR7 agonist R848 that induces type I interferon and TNFa after oral gavage. Our results show an altered subset distribution of MNP in neonatal mice (predominance of cDC1 and cDC2b, reduced proportion of cDC2a) and a reduced potential to take up microorganisms and process/present antigen as well as decreased type I interferon mediated gene expresseion. R848 administration could partly overcome this maturation defect of neonatal MNP by increasing the proportion of CCR7+ mature cDC as well as upregulation of interferon I dependent genes.
Project description:The Toxoplasma type I ROP16 kinase directly activates the host STAT3 and STAT6 transcription factors and when transgenically expressed in the orally virulent type II strain, promotes host resistance to oral challenge. The transcriptional profile of type II and II+ROP16I infected Peyer's patches and intestines from orally infected mice on day 5 was determined to elucidate host signaling pathways and molecular gene targets that correlate with protective immunity in the gut of orally challenged animals C57BL/6 female mice were orally gavaged with 1000 tissue cysts of the type II or II+ROP16I strain. On Day 5 of infection the Peyer's patches and intestines were analyzed for parasite burden by bioluminescence imaging. Individual Peyer's patches and intestinal sections, corresponding to the middle third of the intestine (~jejunum), that had equivalent parasite burden were snap frozen in liquid nitrogen. The samples were crushed using a sterile 16 G needle in tubes on dry ice. In the case of the intestine, the sample was resuspended in TRizol, extruded through a needle using a syringe and RNA was isolated according to manufacturer's protocol; for the Peyer's patch, the sample was suspended in cell lysis buffer and RNA isolated using the RNeasey kit (Invitrogen) according to the manufacter's protocol.
Project description:This study couples a swine experimental model of non-typhoid salmonellosis to laser capture microdissection and microarray analysis to dissect the mechanisms carried out in the follicles of ileum Peyer’s Patches in response to Salmonella Typhimurium infection. Affymetrix GeneChip® Porcine genome array was used to study the gene expression profiles of Peyer's Patches grom control and infected pigs at acute phase of infection.
Project description:To establish better understanding of cells found in jejunal and ileal Peyer's patches of pigs, we utilized single-cell RNA sequencing scRNA-seq and spatial transcriptomics to recover and analyze cells and spatial regions from sections of jejunum and ileum containing Peyer's patches. Cells identified via single-cell RNA sequencing included B, T/innate lymphoid cell, myeloid, epithelial, and stromal lineage cells. Spatial dots recovered via spatial transcriptomics belonged to regions including villi, crypts, interfollicular/parafollicular zones, follicles, and muscularis. Overall, results provide new information on regional localization and transcriptional profiles of cells in the pig small intestine.
Project description:PeyerM-bM-^@M-^Ys patches (PP) are primary inductive sites of mucosal immunity. Defining PP mononuclear phagocyte system (MPS) is thus crucial to understand the initiation of mucosal immune response. We provide a comprehensive analysis of the phenotype, distribution, ontogeny, lifespan, function and transcriptional profile of PP MPS. We show that monocytes give rise to macrophages and to lysozyme-expressing DC (LysoDC) which are both involved in particulate antigen uptake, display strong innate antiviral and antibacterial gene signatures and, upon TLR7 stimulation, secrete IL-6 and TNF but no IL-10. However, unlike macrophages, LysoDC display a rapid renewal rate, strongly express genes of the MHCII presentation pathway and prime naM-CM-/ve helper T cells for IFNg production. Our results show that in PP, at steady state, monocytes generate both LysoDC and macrophages which display distinct features from their adjacent villus counterparts. 3 replicates of 3 different mononuclear phagocyte subsets have been extracted from Peyer's Patches of WT C57Bl/6 mice: CD11b+ DC, lysoDC and lysoMac. The total RNA of PP-sorted cells from the 3 independent experiments was extracted with a Qiagen micro RNAeasy PLUS kit. Quantity, quality and absence of genomic DNA contamination were assessed with a Bioanalyser (Agilent). Microarray experiments were performed by the Plateforme Biopuces of Strasbourg (France) using the GeneChipM-BM-. Mouse Gene 1.0 ST array.
Project description:Fumonisin B1 (FB1) is a mycotoxin produced by Fusarium species. In mammals, this toxin causes multiple organ-specific damages. Among its multiple effects, FB1 promotes hepatotoxicity, is immunotoxic and alters the intestinal functions. Despite its inhibitory effect on de novo ceramide synthesis, the molecular mechanism of FB1 action and toxicity remain unclears. In order to explore the mechanism of FB1 toxicity, we analyzed the transcriptome of the jejunal Peyer's patches.
Project description:Primary RNASeq data for progenitor, resident, and stimulated (C.alb, LPS, injury, APAP+ starved overnight and pIC) mononuclear phagocytes from fourteen organs.