Acute effects caused by the non-genotoxic carcinogen and peroxisome proliferator (PP) diethylhexylphthalate (DEHP) in the mouse liver
Gene ontology mapping as an unbiased method for identifying molecular pathways and processes affected by toxicant exposure: application to acute effects caused by the rodent non-genotoxic carcinogen diethylhexylphthalate.
Sex, Specimen part, Compound, Time
View SamplesEpithelial-mesenchymal transition (EMT) has been linked to cancer progression and metastatic propensity. The 4T1 tumor is a clinically relevant model of spontaneous breast cancer metastasis. Here we characterize 4T1-derived cell lines for EMT, in vitro invasiveness and in vivo metastatic ability. Contrary to expectations, the 67NR cells, which form primary tumors but fail to metastasize, express vimentin and N-cadherin, but not E-cadherin. 4T1 cells, however, express E-cadherin, are highly migratory and invasive, and metastasize to multiple sites. The 66cl4 metastatic cells display mixed epithelial and mesenchymal markers, but are less migratory and invasive than 67NR cells. These findings demonstrate that the metastatic ability of breast cancer cells does not correlate with genotypic and phenotypic properties of EMT per se, and suggest that other processes may govern metastatic capability. Gene expression analysis also has not identified differences in EMT markers, but has identified several candidate genes that may influence metastatic ability.
Epithelial-mesenchymal transition (EMT) is not sufficient for spontaneous murine breast cancer metastasis.
Sex, Specimen part
View SamplesAlthough mast cells elicit proinflammatory and type I IFN responses upon VSV infection, in response to L.monocytogenes (L.m) or S. Typhimurium (S.t), such cells elicit a transcriptional program devoid of type I IFN response.
Mast cells elicit proinflammatory but not type I interferon responses upon activation of TLRs by bacteria.
Specimen part
View SamplesThe Rift Valley Fever (RVF) is an arthropod-borne disease present in several countries of Africa and Middle East. It is caused by RVF virus which can infect both humans and animals. In humans, it leads to various manifestations including hepatitis, encephalitis and death, while in domestic animals it usually causes miscarriage in pregnant females and it is often fatal for the newborn. Not all people or animal infected by the virus present the same disease. Some patients exhibit unapparent or moderate febrile reactions, while others develop severe symptoms. This observation suggests that host genetic factors play a role in controlling the outcome of infection. In this work, we compare the response of two different inbred strains of mice, MBT/Pas and BALB/cByJ, to infection with RVF virus. These strains exhibit different profiles of susceptibility to RVF virus infection. Indeed, MBT/Pas mice rapidly develop high viraemia and die soon after infection, while BALB/cByJ mice have a lower viraemia and die later. Interestingly, mouse embryonic fibroblasts (MEFs) obtained from MBT/Pas foetuses allows higher viral production than BALB/cByJ MEFs.
A new mouse model reveals a critical role for host innate immunity in resistance to Rift Valley fever.
Specimen part
View SamplesTo acquire more information regarding the local immune events during the different phases of S. aureus infection, gene profiling using microarray technology was used to identify host genes whose expression is substantively altered in the kidneys during the acute (T2) and persistent phase of infection (T28). Genes associated with the distinct transcript profiles were identified by comparing the relative abundance of transcripts at 2 days (acute) and 28 days (persistent) of infection to their abundance in the kidneys of uninfected control animals (CTL).
The dynamics of T cells during persistent Staphylococcus aureus infection: from antigen-reactivity to in vivo anergy.
Specimen part
View SamplesRole for naturally occurring CD4+CD25+Foxp3+ regulatory T cells (nTregs) in counterbalancing this process. Using a transgenic murine model for autoimmune-mediated lung disease, we demonstrated that, despite pulmonary inflammation, lung-specific CD8+ T cells can reside quiescently in close proximity to self-antigen. Whereas self-reactive CD8+ T cells in the inflamed lung and lung-draining lymph nodes down-regulated the expression of effector molecules, those located in the spleen appeared to be partly antigen-experienced and displayed a memory-like phenotype. Since ex vivo-reisolated self-reactive CD8+ T cells were very well capable to respond to the antigen in vitro, we investigated a possible contribution of nTregs to the immune control over autoaggressive CD8+ T cells in the lung.
CD4+CD25+Foxp3+ regulatory T cells are dispensable for controlling CD8+ T cell-mediated lung inflammation.
Specimen part
View SamplesBiliary atresia (BA) is a rare cholestatic disease of unknown etiology that affects infants and shows an incidence of 1 out of 18,000 live births in Europe (1). The first therapeutic option is a timely performed portoenterostomy. However, the majority of patients suffer from a progressive inflammatory process, which leads to complete destruction of the extra- and intrahepatic biliary system followed by end-stage liver cirrhosis. Hence, BA is the leading indication for pediatric liver transplantation worldwide (2, 3). To understand the pathogenesis of the disease and improve theoutcome of BA patients, research has focused on the inflammatory process in liver and bile ducts, in which several factors are remarkably elevated, such as activated CD4 and CD8 T-cells, TNF alpha,IFN alpha and other proinflammatory TH1 cytokines (3-8). By the time of diagnosis, however, the disease has already reached an advanced state, characterized by the complete obstruction of the extrahepatic bile ducts with impaired bile flow and fibrosis or cirrhosis of the liver. Therefore, studies in humans focusing on the trigger mechanism of BA are limited due to the paucity of liver and availability of bile duct tissue for research. One infectious animal model has been developed, in which newborn Balb/c mice exclusively show the experimental BA phenotype after infection with rhesus rotavirus (RRV) (9, 10). This model allows the analysis of the inflammatory reactions in liver and bile ducts at early steps in the development of bile duct atresia (11-20). Furthermore, inbred mouse strains have been shown to have a different susceptibility for the development of experimental BA, suggesting that Balb/c mice have an immunological gap responsible for disease progression (10, 12). The aim of this study was to identify key genes responsible for the BA phenotype by comparing the transcriptomes at an early time point after virus infection, i.e. before bile duct atresia, between two mouse strains with different susceptibilities to BA. Differences in the virus titration and the clinical course of infected mice were analyzed, and variations in the hepatic gene response assessed by comparative microarray assays were correlated to variances in the hepatic inflammatory reaction.
Susceptibility to experimental biliary atresia linked to different hepatic gene expression profiles in two mouse strains.
Specimen part
View SamplesIn the VILLIN-HA/CL4-TCR transgenic mouse model a population of CD8 T cells with suppressive capacities was indentified. For the molecular characterisation of CD8 regulatory T cells gene comparative expression profiles of naive, activated and regulatory CD8 T cells were performed.
No associated publication
Specimen part
View SamplesThe zinc finger transcription factor growth-factor-independent-1 (Gfi1) has been involved in various cellular differentiation processes. Gfi1 acts as a transcriptional repressor and splicing control factor upon binding to cognate binding sites in regulatory elements of its target genes. Here, we report that Gfi1-deficient mice develop autoimmunity. Gfi1-deficient peripheral B-cells show a hyperproliferative phenotype, leading to expansion of plasma cells, increased levels of nuclear autoantibodies, and immunoglobulin deposition in brain and kidneys. Dysregulation of multiple transcription factors and cell-cycle control elements may contribute to B-cell dependent autoimmunity. Gfi1 thus emerges as a novel master-regulator restricting autoimmunity.
No associated publication
Specimen part
View SamplesNaturally occurring CD25+CD4+ regulatory T cells (T reg cells) are currently intensively characterized because of their major importance in modulating host responses to tumors and infections, in preventing transplant rejection, and in inhibiting the development of autoimmunity and allergy. Originally, CD4+ T reg cells were identified exclusively by the constitutive expression of CD25, and many in vivo experiments have been performed using depleting antibodies directed against CD25. However, both the existence of CD25 T reg cells, especially within peripheral tissues, as well as the expression of CD25 on activated conventional T cells, which precludes discrimination between T reg cells and activated conventional T cells, limits the interpretation of data obtained by the use of anti-CD25 depleting antibodies. The most specific T reg cell marker currently known is the forkhead box transcription factor Foxp3, which has been shown to be expressed specifically in mouse CD4+ T reg cells and acts as a master switch in the regulation of their development and function. To address the question of the in vivo role of T reg cells in immunopathology, we have generated bacterial artificial chromosome (BAC)transgenic mice termed depletion of regulatory T cell (DEREG) mice, which express a diphtheria toxin receptor (DTR) enhanced GFP (eGFP) fusion protein under the control of the foxp3 locus, allowing both detection and inducible depletion of Foxp3+ T reg cells. The gene expression profile of both CD4+eGFP+FoxP3+ and CD4+eGFPnegFoxP3neg cells isolated from DEREG mice was here analyzed by micro array.
Immunostimulatory RNA blocks suppression by regulatory T cells.
Specimen part
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