Project description:Microarray profiling of amplified total RNA isolated from neutrophils sorted from naïve, Nippostrongylus brasiliensis (Nb)-infected, or lipopolysaccharide (LPS)-treated mice.
Project description:Mycobacterium infection gives rise to granulomas predominantly composed of inflammatory M1-like macrophages, with bacteria-permissive M2 macrophages also detected in deep granulomas. Our histological analysis of Mycobacterium bovis bacillus Calmette-Guerin-elicited granulomas in guinea pigs revealed that S100A9-expressing neutrophils bordered a unique M2 niche within the inner circle of concentrically multilayered granulomas. We evaluated the effect of S100A9 on macrophage M2 polarization based on guinea pig studies. S100A9-deficient mouse neutrophils abrogated M2 polarization, which was critically dependent on COX-2 signaling in neutrophils. Mechanistic evidence suggested that nuclear S100A9 interacts with C/EBPβ, which cooperatively activates the Cox-2 promoter and amplifies prostaglandin E2 production, followed by M2 polarization in proximal macrophages. Since the M2 populations in guinea pig granulomas were abolished via treatment with celecoxib, a selective COX-2 inhibitor, we propose the S100A9/Cox-2 axis as a major pathway driving M2 niche formation in granulomas.
Project description:Goal: To examine the effects of human resistin during helminth infection. Methodology: To examine the function of human resistin (hResistin), we utilized transgenic mice expressing the human resistin gene along with its entire regulatory region (hRetnTg+). Following infection with the helminth Nippostrongylus brasiliensis, whole lung RNA was sequenced in hRetnTg+ mice, control hRetnTg- and naïve mice. Conclusion: In hRetnTg+ mice, many genes involved in inflammation and the immune system, specifically toll-like receptor signaling and chemokines, are significantly upregulated, suggesting that human resistin promotes TLR signaling and inflammation during helminth infection. Examination of whole lung mRNA from Nippostrongylus brasiliensis-infected lungs at day 7 in mice expressing human resistin
Project description:We use a genome wide transcriptomic approach to assess the effects of protein supplementation on gene expression in the small intestine of periparturient rats during a secondary infection with the rat nematode Nippostrongylus brasiliensis
Project description:We compare the transcription profiles of IL-5-reporter marked ILC2s and Th2 cells sorted from mouse lung tissue after Nippostrongylus brasiliensis infection
Project description:Infection with Nippostrongylus brasiliensis results in persistent changes to the lung environment. Cytokine profiling reveals a sustained increase in both Th1 and Th2 transcripts. Cellular populations of macrophages display an alternative phenotype, with upregulation of YM1, Arg1, Mrc1 as well as Class II MHC. These alternatively activated alveolar macrophages (AAAMs) also increase drastically in number. Subsequent challenge with house dust mite (HDM) Dermatophagoides pteronyssinus shows a reduced allergic phenotype, with decreased fold changes in effector cell cytokines of both the Th1 and Th2 variety indicative of the new regulatory environment established in the lung by helminth infection. Histological examination of the lung environment reveals a significant decrease in eosinophila and reduced mucous production by bronchial epithelial cells. Experiment Overall Design: BALB/c mice were challenged with 500 infectious L3 stage Nippostrongylus brasiliensis larvae subcutaneously. Mice were allowed to resolve their infection, then were sensitized twice with 75 allergy units (AU) of HDM bound to 1mg of alum intraperitoneally. Two challenge doses of 50AU HDM in PBS were given intranasally one day apart, then lungs were harvested at 6, 24 and 72 hours post challenge. Mice were analyzed by histology, immunohistochemistry, real time RT-PCR and affymetrix gene array analysis using full genome chips.
Project description:We were interested in investigating the heterogeneity of CD4+ Th2 cells during infection response. In order to do so we injected Nippostrongylus brasiliensis (Nb) in recipient mice as this is known to elicit a Type 2 response. Mice were subcutaneously injected with Nb larvae and single CD4+ cells were isolated from mediastinal lymph nodes, mesenteric lymph nodes, and lungs 5 days after infection.
Project description:Inflammation is the natural defensive response of the immune system to an injury or infection and is regulated by small molecule mediators triggering different phases of the inflammatory process. In particular, lipid mediators (LM) and cytokines exhibit crucial regulatory functions in the progression and resolution of inflammation. Macrophages play a central role in this process and can adopt distinct phenotypes with specialized functions depending on their microenvironment: inflammatory M1 macrophages drive inflammation by the release of pro-inflammatory cytokines and LMs, like prostaglandins (PG) and leukotrienes (LT), while resolving M2 macrophages promote inflammation resolution and tissue regeneration by production of anti-inflammatory cytokines and specialized pro resolving mediators (SPM). Aging is associated with chronic and unresolved, low-grade inflammation (“inflammaging”) and aging-related dysfunction of macrophages in the resolution of inflammation and tissue maintenance has been reported. Yet, the underlying molecular mechanisms and functional consequences of latter processes remain poorly understood. Here, we show that polarization of peritoneal macrophages (PM) from geriatric mice towards an M2-like phenotype is impaired versus adult mice, resulting in aberrant LM formation and cytokine release. In PMs isolated from adult mice (PM-A) we observed a shift in LM formation from PGs and LTs to SPMs already after 4 h of polarization towards M2 with interleukin (IL) 4. In contrast, PMs from geriatric mice (PM-G) produced mainly LTs and PGs upon polarization. This pattern persists over the course of 48 h of polarization. Proteomic profiling revealed that polarization of PM A towards M2 yields a more distinct phenotype, clearly separated from M1, when compared to PM-G. We observed similar aging-related changes in the lipidome and cytokine profile of spleen, lung and liver tissue from mice. Hence, we hypothesize that during aging macrophage polarization towards M2 is impaired, which in turn drives chronic inflammation and disturbs tissue maintenance. By combining state-of-the art lipidomic and proteomic profiling we aim to uncover new molecular targets for pharmaceutical interventions to improve therapeutic strategies for elderly patients with chronic inflammatory diseases.
Project description:By investigating the germinal center (GC) formation in STAT6ko/WT bone marrow-mixed chimera we found that GC formation in type 2 immune responses is dependent on B cell intrinsic expression of IL-4/IL-13-induced genes. We therefore used microarrays to find Stat6 dependent genes that are important for germinal center formation and/or organization after infection with the nematode Nippostrongylus brasiliensis (N. brasiliensis).
Project description:The intestinal epithelium is our first line of defense against infections of the gut and the plasticity in cellular differentiation of the intestinal epithelium is an important part of this response. Here we sequenced the small intestinal epithelium from mice infected with Nippostrongylus brasiliensis to determine how the intestinal epithelium adapts in the context of an infection. By comparing these data to small intestinal organoids treated with cytokines (see related accessions) we determine that the intestinal epithelial response to N. brasiliensis infection correspond to a type II infection driven by IL-13.