The objective is to identify genes that are differentially expressed following the introduction of DNA double strand breaks (DSBs) by the Rag proteins in murine pre-B cells. Cells lacking Artemis are used since the Rag-induced DSBs will not be repaired and, thus, will provide a continuous stimulus to the cell. Cells lacking Artemis and Atm are used to determine which gene expression changes depend on Atm and cells lacking Artemis that express an I kappa B alpha dominant negative are used to determine which gene expression changes depend on NFkB.
DNA double-strand breaks activate a multi-functional genetic program in developing lymphocytes.
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View SamplesOcular immune privilege (IP) limits immune surveillance of intraocular tumors as certain immunogenic tumor cell lines (P815, E.G7-OVA) that are rejected when transplanted in the skin grow progressively when placed in the anterior chamber (a.c.) of the eye. As splenectomy (SPLNX) is known to terminate ocular IP, we characterized immune mechanisms responsible for spontaneous rejection of intraocular tumors in SPLNX mice as a first step toward identifying how to restore tumoricidal activity within the eye. Microarray data showed a 3-fold increase in interferon (IFN)- and a 2.7-fold increase in Fas ligand (FasL). There was a robust increase in transcripts (127 of 408 surveyed) from interferon (IFN)-stimulated genes and a marked decrease (in 40 of 192 surveyed) in the expression of cell-cycle-associated genes. Non-microarray data confirmed that IFN, FasL and CD8+ T cells but not perforin or TNF were required for elimination of intraocular E.G7-OVA tumors that culminated in destruction of the eye (ocular phthsis). IFN and FasL did not target tumor cells directly as the majority of SPLNX IFNR1-/- mice and Fas-defective lpr mice failed to eliminate ocular E.G7-OVA tumors that expressed Fas and IFNR1. Bone marrow chimeras showed that immune cell expression of IFNR1 and Fas was critical and that SPLNX increased the frequency of activated macrophages within ocular tumors in an IFN- and Fas/FasL-dependent manner. Rejection of intraocular tumors was associated with increased ocular mRNA expression of several inflammatory genes including FasL, NOS2, CXCL2 and T-bet. Our data support a model in which IFN- and Fas/FasL-dependent activation of intratumoral macrophage by CD8+ T cells promotes severe intraocular inflammation that indirectly eliminates intraocular tumors by inducing phthisis. The immunosuppressive mechanisms which maintain ocular IP likely interfere with the interaction between CD8+ T cells and macrophage to limit immunosurveillance of intraocular tumors.
Splenectomy promotes indirect elimination of intraocular tumors by CD8+ T cells that is associated with IFNγ- and Fas/FasL-dependent activation of intratumoral macrophages.
Specimen part, Treatment
View SamplesRetinal damage causes proliferation of Muller glia, but the degree of proliferation depends on mouse strains. Muller glial proliferation was significantly promoted by the addition of GSK3 inhibitor in 129, but not in B6. We used retinal explant culture as a model for retinal damage which caused preferential photoreceptor death in a few days.
Proliferation potential of Müller glia after retinal damage varies between mouse strains.
Age, Specimen part
View SamplesThe E-protein transcription factors E2A and HEB play important roles at several stages of hematopoiesis. However, the exact mechanism for theire action and the main targets in the LY6D negative common lymphoid progentior (CLP) compartment remains unknown. By adressing this question, we will gain important infromation regarding the early events leading to B-cell specification.
The transcription factors E2A and HEB act in concert to induce the expression of FOXO1 in the common lymphoid progenitor.
Specimen part
View SamplesIn order to investigate molecular events involved in the regulation of lymphoid lineage commitment, we crossed lamda5 reporter transgenic mice to mice where the GFP gene is inserted into the Rag1 locus. This allowed us to sub-fractionate common lymphoid progenitors (CLPs) and pre-pro-B cells into lamda5-Rag1low, lamda5-Rag1high and lamda5+Rag1high cells. Clonal in vitro differentiation analysis demonstrated that Rag1low cells gave rise to B/T and NK cells. Rag1high cells displayed reduced NK-cell potential with preserved capacity to generate B- and T-lineage cells while the lamda5+ cells were B-lineage restricted. Ebf1 and Pax5 expression was largely confined to the Rag1high populations. These cells also expressed a higher level of the surface protein LY6D providing an additional tool for the analysis of early lymphoid development. These data suggest that the classical CLP compartment composes a mixture of cells with more or less restricted lineage potentials opening new possibilities to investigate early hematopoiesis.
Single-cell analysis of the common lymphoid progenitor compartment reveals functional and molecular heterogeneity.
Specimen part
View SamplesE-FABP expression in keratinocytes increase interferons, in particualur IFNlamda, expression, which activate P53, a critical tumor suppessor, to inhibit or prevent chemical-induced skin tumorigenesis.
Epidermal FABP Prevents Chemical-Induced Skin Tumorigenesis by Regulation of TPA-Induced IFN/p53/SOX2 Pathway in Keratinocytes.
Specimen part
View SamplesGene expression profiles of Immortalized KDM5A-/- MEFs with re-introduction of wild-type KDM5A or KDM5A-H483A mutant.
The KDM5 family is required for activation of pro-proliferative cell cycle genes during adipocyte differentiation.
Specimen part
View SamplesThe ACBP knockout were created by targeted disruption of the gene in mice. The expression profiling was performed on liver tissue from ACBP-/- (KO) and +/+ (WT) mice at the age of 21 days, which in our study is the time immediately before weaning. The mice used for this experiment were taken directly away from their mother. Thus, having free access to chow and breast milk until sacrificed at 8-11am
Disruption of the acyl-CoA-binding protein gene delays hepatic adaptation to metabolic changes at weaning.
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 SamplesIn order to identify the targets of GATA4-FOG2 action in mammalian heart development we performed Affymetrix microarray comparisons of gene expression in normal and mutant at embryonic (E) day E12.5 hearts. We compared RNA samples from both Fog2-null and Gata4ki/ki mutant E12.5 hearts to the wild-type control E12.5 hearts. We reasoned that as the phenotypes of the Fog2 knockout and Gata4ki/ki mutation (a V217G mutation that specifically cripples the interaction between GATA4 and FOG proteins) are similar, we should expect to identify a similar set of differentially expressed genes in both experiments. As an additional control, we expected to find the Fog2 gene expression absent in the mutant (null) Fog2 cardiac sample, but not Gata4ki/ki sample.
Cardiac expression of Tnnt1 requires the GATA4-FOG2 transcription complex.
Specimen part
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