Project description:Use of human whole blood for transcriptomic analysis has potential advantages over the use of isolated immune cells for studying the transcriptional response to pathogens and their products. Whole blood stimulation can be carried out in a laboratory without the expertise or equipment to isolate immune cells from blood, with the added advantage of being able to undertake experiments using very small volumes of blood. Toll like receptors (TLRs) are a family of pattern recognition receptors which recognise highly conserved microbial products. Using the TLR2 ligand (Pam3CSK4) and the TLR4 ligand (LPS) human whole blood was stimulated for 0, 1, 3, 6, 12 or 24 hours at which times mRNA was isolated and a comparative microarray was undertaken. A common NFκB transcriptional programme was identified following both TLR2 and TLR4 ligation which peaked at between 3 to 6 hours including upregulation of many of the NFκB family members. In contrast an interferon transcriptional response was observed following TLR4 but not TLR2 ligation as early as 1 hour post stimulation and peaking at 6 hours. These results recapitulate the findings observed in previously published studies using isolated murine and human myeloid cells indicating that in vitro stimulated human whole blood can be used to interrogate the transcriptional kinetics response of innate cells to TLR ligands. Our study demonstrates that with a systems biology approach analysis of mRNA isolated from human whole blood can delineate both the temporal response and the key transcriptional differences following TLR2 and TLR4 ligation.
Project description:Use of human whole blood for transcriptomic analysis has potential advantages over the use of isolated immune cells for studying the transcriptional response to pathogens and their products. Whole blood stimulation can be carried out in a laboratory without the expertise or equipment to isolate immune cells from blood, with the added advantage of being able to undertake experiments using very small volumes of blood. Toll like receptors (TLRs) are a family of pattern recognition receptors which recognise highly conserved microbial products. Using the TLR2 ligand (Pam3CSK4) and the TLR4 ligand (LPS) human whole blood was stimulated for 0, 1, 3, 6, 12 or 24 hours at which times mRNA was isolated and a comparative microarray was undertaken. A common NFκB transcriptional programme was identified following both TLR2 and TLR4 ligation which peaked at between 3 to 6 hours including upregulation of many of the NFκB family members. In contrast an interferon transcriptional response was observed following TLR4 but not TLR2 ligation as early as 1 hour post stimulation and peaking at 6 hours. These results recapitulate the findings observed in previously published studies using isolated murine and human myeloid cells indicating that in vitro stimulated human whole blood can be used to interrogate the transcriptional kinetics response of innate cells to TLR ligands. Our study demonstrates that with a systems biology approach analysis of mRNA isolated from human whole blood can delineate both the temporal response and the key transcriptional differences following TLR2 and TLR4 ligation. 6 healthy human volunteers. 1ml whole blood stimulated in vitro with either LPS (1ng/ml), Pam3CSK4 (200ng/ml) or media for 0, 1, 3, 6 12 or 24 hours.
Project description:Chitin is the second most abundant polysaccharide in nature and a biomolecule intimately linked to fungal infection and allergic asthma, conditions that affect millions of patients worldwide. Chitin is known to stimulate multiple mammalian immune cells, but the precise molecular sensing mechanism has not been elucidated, hampering strategies to specifically target chitin-mediated pathologies. The study associated with this microarray dataset uses defined chitin oligomers to identify six chitin subunits as the smallest immunologically active chitin motif and the innate immune receptor TLR2 as the molecular chitin sensor on human and murine immune cells, in vitro and in vivo. The goal of this microarray dataset was to elucidate transcriptional differences of human whole blood cells when responding to chitin, to other TLR2 ligands (Pam2, Pam3), and furthermore to the TLR4 ligand LPS. All four stimulants are compared to each other and to the unstimulated whole blood samples as a reference. We conclude that chitin oligomers elicitd overlapping yet distinct signaling outcomes compared to canonical TLR2 ligands.
Project description:Toll-like receptors (TLRs) are important mediators of chronic inflammation in numerous autoimmune diseases, although the role of these receptors in primary Sjögren’s syndrome (pSS) remains incompletely understood. Previous studies in our laboratory established Myd88 as a crucial mediator of disease, although the upstream signaling events that culminate in Myd88 activation have yet to be identified. To objective of this study was to identify specific Myd88-dependent TLR-related pathways that are dysregulated both locally and systemically in a mouse model of pSS (NOD.B10Sn-H2b/J (NOD.B10)). We performed RNA-sequencing on spleens derived from NOD.B10 mice. We then harvested salivary tissue and spleens from Myd88-sufficient and deficient C57BL/10 (BL/10) and NOD.B10 mice and performed flow cytometry to determine expression of Myd88-dependent TLRs. We then cultured splenocytes with TLR2 and TLR4 agonists and measured IL-6 secretion by ELISA. Next, we evaluated spontaneous and TLR4-mediated inflammatory cytokine secretion in NOD.B10 salivary tissue. Finally, we assessed spontaneous Myd88-dependent cytokine secretion by NOD.B10 salivary cells. We identified dysregulation of numerous TLR-related networks in pSS splenocytes, particularly those employed by TLR2 and TLR4. We found upregulation of TLRs in both the splenic and salivary tissue from pSS mice. In NOD.B10 splenic tissue, B cell TLR1, TLR2, and TLR6 expression was reduced to levels of BL/10 controls in the absence of Myd88. Splenocytes from NOD.B10 mice were hyper-responsive to TLR2 ligation and the endogenous molecule decorin modulated inflammation via TLR4. Finally, we found spontaneous secretion of numerous inflammatory cytokines and this was enhanced following TLR4 ligation in female NOD.B10 salivary tissue as compared to males. Moreover, we found that spontaneous production of salivary IL-6, MCP-1 and TNFa requires Myd88 in pSS salivary tissue. Thus, our data demonstrate that Myd88-dependent TLR pathways contribute to the inflammatory landscape in pSS, and inhibition of such will likely have therapeutic utility.
Project description:The human-specific, Gram-negative bacterium Neisseria meningitidis (Nm) is a leading cause of bacterial meningitis world-wide. It has been described that Nm can enter the central nervous system via the blood-cerebrospinal fluid barrier (BCSFB), which is constituted by the epithelial cells of the choroid plexus. Using a recently established in vitro model of the human BCSFB based on human malignant choroid plexus papilloma (HIBCPP) cells we investigated the cellular response of HIBCPP cells challenged with the meningitis-causing Nm strain MC58. In comparison we analysed the answer to the closely related unencapsulated carrier isolate Nm α14. Transcriptome analysis revealed a stronger transcriptional response after infection with strain MC58, in particular with its capsule deficient mutant MC58siaD-, which correlated with bacterial invasion levels. Expression evaluation and Gene Set Enrichment Analysis pointed to a NF-κB-mediated pro-inflammatory immune response involving up-regulation of the transcription factor IκBζ. Consistent with this, infected cells secreted significant levels of pro-inflammatory chemokines and cytokines, among others, IL8, CXCL1-3 and the IκBζ target gene product IL6. Expression profile of pattern recognition receptors in HIBCPP cells and the response to specific agonists indicates that TLR2 rather than TLR4 is involved in the cellular reaction following Nm infection.
Project description:Exposure of human monocytes to lipopolysaccharide (LPS) or other pathogen-associated molecular pattern (PAMPs) induces a temporary insensitivity to subsequent LPS challenges, a cellular state called endotoxin tolerance (ET). The tolerant state of monocytes is accompanied by cell surface and other glycoprotein expression changes induced by the activation of Toll-like receptors (TLRs). In this study, we aimed to characterize the cellular state of human monocytes stimulated with Gram-positive Staphylococcus aureus and TLR2 ligands. We analyzed gene expression changes induced by S. aureus after 2 and 24 hours by amplicon sequencing (RNA-AmpliSeq) and compared the pro-inflammatory response after 2 hours of stimulation to the to the response in re-stimulation experiments after the first stimulus. In parallel, glycoprotein expression changes in human monocytes after 24 hours of S. aureus stimulation were analyzed by proteomics and compared to stimulation experiments with TLR2 ligands Malp-2 and Pam3Cys and TLR4 ligand LPS. The results demonstrate that monocytes stimulated with S. aureus and TLR ligands entered the tolerant cell state after activation. Compared to TLR agonist mediated activation and tolerization of monocytes, glycoprotein expression changes induced by S. aureus stimulation revealed significant differences in receptor expression profiles. We report a glycoprotein expression profile characteristic for PAMP and S. aureus tolerized human monocytes. Finally, we analyzed peripheral blood monocytes of patients with S. aureus bloodstream infection for inflammatory responses in vitro and for their glycoprotein expression profiles. RNA-AmpliSeq data from patient-derived monocytes demonstrated that the cells were pro-inflammatory responsive to S. aureus stimulation and expressed higher level of CD44 mRNA, while other markers of the tolerant cell state were not detected.
Project description:The Toll-like receptors (TLRs) recognize different pathogen associated molecular patterns (PAMPs) and promote MyD88 dependent and independent responses. Previously, we have reported the discovery of the temporal changes in signaling cascades of macrophage proteome and secretome post-stimulation with different PAMPs. Here we present strategies to profile the secretome of TLR2-, TLR4, and TLR7- stimulated macrophages using whole pathogens were developed. Stable isotope labeling with amino acids in cell culture of macrophages was integrated with whole pathogen macrophage stimulation and subsequent targeted proteomics to quantify cytokines, chemokines, and transcription factors.
Project description:Toll-like receptors (TLRs) are essential sensors in innate immunity and among the first to detect invading pathogens. Many studies of TLR responses have focused on the intracellular signaling events that occur upon receptor stimulation. However, proteins released from the cell play a key role in cell-cell communication during an immune response. We have used mass spectrometry-based proteomic methods to investigate both the intracellular and extracellular responses of macrophages stimulated with individual TLR2, TLR4, and TLR7 ligands and whole pathogens. We performed global quantitative analyses of the mouse macrophage proteome and secretome using stable isotope labeling with amino acids and high-resolution mass spectrometry.
Project description:We performed a systematic analysis of the coding and non-coding transcriptomes of human macrophages after stimulation with ligands to TLR2/6 (FSL), TLR 1/2 (Pam3CSK4), and TLR4 (LPS)