FNDC4 is a novel secreted factor sharing high homology with the exercise-associated myokine irisin (FNDC5). Here we report that Fndc4 is robustly upregulated in various mouse models of inflammation as well as in human inflammatory conditions. Specifically, subjects with inflammatory bowel disease show increased FNDC4 levels locally at inflamed sites of the intestine. Interestingly, administration of recombinant FNDC4 during colitis development in mice resulted in markedly reduced disease severity compared to mice injected with a control protein. Conversely, mice that lacked Fndc4 showed increased colitis severity. Analysis of binding of FNDC4 to different immune cell types revealed strong and specific binding to macrophages and monocytes. FNDC4 treatment of bone marrow-derived macrophages in vitro resulted in reduced phagocytosis, improved survival and reduced pro-inflammatory chemokine expression. Hence, treatment with FNDC4 resulted in a state of dampened macrophage activity, while enhancing their survival. Thus, we have characterized a novel factor with direct therapeutic potential in inflammatory bowel disease and possibly other inflammatory diseases.
FNDC4 acts as an anti-inflammatory factor on macrophages and improves colitis in mice.
Sex, Specimen part, Treatment
View SamplesThe stomach is often considered a single compartment, but morphological differences among different areas are well known. Oxyntic mucosa (OXY) is primarily equipped for acid secretion, while it is not enough clear if gastric functional control are shared with other areas.
Differential gene expression in the oxyntic and pyloric mucosa of the young pig.
Sex, Specimen part
View SamplesTumor growth is associated with a profound alteration of myelopoiesis, leading to recruitment of immunosuppressive cells known as myeloid-derived suppressor cells (MDSCs). Analyzing the cytokines affecting myelo-monocytic differentiation produced by various experimental tumors, we found that GM-CSF, G-CSF, and IL-6 allowed a rapid generation of MDSCs from precursors present in mouse and human bone marrow (BM). BM-MDSCs induced by GM-CSF+IL-6 possessed the highest tolerogenic activity, as revealed by the ability to impair the priming of IFN- -producing CD8+ T cells upon in vivo adoptive transfer. Moreover, adoptive transfer of syngeneic, GM-CSF+IL-6-conditioned MDSCs to diabetic mice transplanted with allogeneic pancreatic islets resulted in long term acceptance of the allograft and correction of the diabetic status. Cytokines inducing MDSCs acted on a common molecular pathway. Immunoregulatory activity of both tumor-induced and BM-derived MDSCs was entirely dependent on C/EBP transcription factor, a key component of the emergency myelopoiesis triggered by stress and inflammation. Adoptive transfer of tumor antigen-specific CD8+ T lymphocytes resulted in therapy of established tumors only in mice lacking C/EBP in myeloid compartment. These data unveil another link between inflammation and cancer and identify a novel molecular target to control tumor-induced immune suppression.
Tumor-induced tolerance and immune suppression depend on the C/EBPbeta transcription factor.
Specimen part
View SamplesCD8+ T-cells inhibit virus replication in SIV-infected rhesus macaques (RM). However, it is unclear to what extent the viral suppression mediated by CD8+ T-cells reflects direct killing of infected cells as opposed to indirect, non-cytolytic mechanisms. In this study, we used functional genomics to investigate potential mechanisms of in vivo viral suppression mediated by CD8+ lymphocytes. Eight chronically SIVmac239-infected RMs underwent CD8+ lymphocyte depletion, and RNA from whole blood was obtained prior to depletion, at the nadir of CD8+ lymphocytes (5 days post-depletion), and during the repopulation phase (11 days post-depletion). Principal components analysis demonstrated that overall gene expression during the nadir of CD8+ T-cells was highly divergent from other intervals. Conversely, the genomic signature of samples from the CD8+ cell rebound phase was similar to that of pre-depletion samples. During CD8+ lymphocyte depletion we detected a strongly significant decrease in the expression of the genes encoding CD8 and CD8 chains, consistent with the near complete CD8+ T-cell depletion measured by flow cytometry. Of note, we observed significant down-regulation of the expression of genes encoding for factors that can suppress SIV replication, including the CCR5-binding chemokine CCL5/Rantes, several retroviral restriction factors (TRIM10, TRIM15, APOBEC3G/H) and defensins. Reduced expression of various genes related to T cell activation and proliferation was also observed. Collectively, these data indicate that depletion of CD8+ lymphocytes in SIV-infected RMs is associated with the establishment of a pattern of gene expression that may result in increased intrinsic permissivity to virus replication.
Transcriptional profiling of experimental CD8(+) lymphocyte depletion in rhesus macaques infected with simian immunodeficiency virus SIVmac239.
No sample metadata fields
View SamplesBackground: The selective absorption of nutrients and other food constituents in the small intestine is mediated by a group of transport proteins and metabolic enzymes, often collectively called intestinal barrier proteins. An important receptor that mediates the effects of dietary lipids on gene expression is the peroxisome proliferator-activated receptor alpha (PPAR), which is abundantly expressed in enterocytes. In this study we examined the effects of acute nutritional activation of PPAR on expression of genes encoding intestinal barrier proteins. To this end we used triacylglycerols composed of identical fatty acids in combination with gene expression profiling in wild-type and PPAR-null mice. Treatment with the synthetic PPAR agonist WY14643 served as reference.
PPARalpha-mediated effects of dietary lipids on intestinal barrier gene expression.
No sample metadata fields
View SamplesAn early settlement of a complex gut microbiota can protect against gastro-intestinal dysbiosis, but the effects of neonatal microbiota colonization and early life feeding of medium chain triglycerides on the maturation of the porcine gastric mucosa are largely unknown.
The effects of starter microbiota and the early life feeding of medium chain triglycerides on the gastric transcriptome profile of 2- or 3-week-old cesarean delivered piglets.
Specimen part
View SamplesAn early settlement of a complex gut microbiota can protect against gastro-intestinal dysbiosis, but the effects of neonatal microbiota colonization on the maturation of the porcine gastric mucosa are largely unknown.
The effects of starter microbiota and the early life feeding of medium chain triglycerides on the gastric transcriptome profile of 2- or 3-week-old cesarean delivered piglets.
Specimen part
View SamplesHyperimmune activation is one of the strong predictors of disease progression during pathogenic immunodeficiency virus infections and is mediated in part by sustained type I interferon (IFN) signaling. Combination antiretroviral therapy suppresses hyperimmune activation only partially in HIV-infected individuals. Here, we show that blockade of Programmed Death-1 (PD-1) during chonic SIV infection significantly reduces the expression of transcripts associated with type I IFN signaling in the blood and colorectal tissue of rhesus macaques (RM). The effect of PD-1 blockade on type I IFN signaling was durable and persisted under high viremia, a condition that is seen in nonprogressive SIV infection in their natural hosts. The reduced type I IFN signaling was associated with enhanced expression of some of the junction-associated genes in the colorectal tissue and a profound decrease in LPS levels in plasma suggesting a possible repair of gut associated junctions and decreased microbial translocation. The reduced type I IFN signaling was also associated with enhanced immunity against gut resident pathogenic bacteria, control of gut associated opportunistic infections and survival of SIV-infected RMs. These results reveal novel mechanisms by which PD-1 blockade enhances survival of SIV-infected RMs and have implications for development of novel therapeutic approaches to control HIV/AIDS.
PD-1 blockade during chronic SIV infection reduces hyperimmune activation and microbial translocation in rhesus macaques.
Specimen part, Disease, Disease stage, Treatment
View SamplesIn SIV/HIV infection, the gastrointestinal tissue dominates as an important site due to the impact of massive mucosal CD4 depletion and immune activation-induced tissue pathology. Unlike AIDS-susceptible rhesus macaques, natural hosts do not progress to AIDS and resolve immune activation earlier. Here, we examine the role of dendritic cells in mediating immune activation and disease progression. We demonstrate that plasmacytoid dendritic cells (pDC) in the blood upregulate 7-integrin and are rapidly recruited to the colorectum following a pathogenic SIV infection in rhesus macaques. These pDC were capable of producing proinflammatory cytokines and primed a Tc1 response in vitro. Consistent with the upregulation of 7-integrin on pDC, in vivo blockade of 47-integrin dampened pDC recruitment to the colorectum and resulted in reduced immune activation. The upregulation of 7-integrin expression on pDC in the blood was also observed in HIV-infected humans but not in chronically SIV-infected sooty mangabeys that show low levels of immune activation. Our results uncover a new mechanism by which pDC influence immune activation in colorectal tissue following pathogenic immunodeficiency virus infections.
Plasmacytoid dendritic cells are recruited to the colorectum and contribute to immune activation during pathogenic SIV infection in rhesus macaques.
Specimen part
View SamplesIntegrins facilitate intercellular movement and communication. Unlike the promiscuous activities of many integrins, 6 integrin is restricted to epithelia and partners exclusively with integrin V to modulate acute lung injury (ALI). Given that ALI is a complication of respiratory infection, we used mice lacking 6 integrin (6 KO) to probe the role of the epithelial layer in controlling the lung microenvironment during infection. We found 6 KO mice were protected from disease caused by influenza and Sendai virus infections. They were also protected from disease caused by Streptococcus pneumoniae infection alone and after prior influenza virus infection, the co-infection representing an often-lethal condition in humans. Resistance in the absence of epithelial 6 integrin was caused by intrinsic priming of the lung microenvironment by type I interferons through a mechanism involving transforming growth factor- regulation. Expression of 6 on epithelia suppresses the production of interferons, providing an advantage to the pathogen. Acute inhibition of 6 function may therefore provide a means to improve outcomes in lung microbial infections.
An Epithelial Integrin Regulates the Amplitude of Protective Lung Interferon Responses against Multiple Respiratory Pathogens.
Specimen part
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