Project description:CD95 acts as an immune suppressor for TNBC tumors when grown in syngeneic mice. 4T1 cells were grown in two mouse strains. Comparisons included parental, a pool stably expressing vCas9 and two clones in which CD95/Fas was deleted using CRISPR-Cas9 gene editing, clone #54 and clone #69.
Project description:Chronic viral infections incapacitate adaptive immune responses by 'exhausting' virus-specific T cells, inducing their deletion and reducing productive T cell memory. Viral infection rapidly induces death receptor Fas (CD95) expression by dendritic cells (DCs) making them susceptible to elimination by the immune response. Lymphocytic Choriomeningitis Virus (LCMV) Clone 13, which normally establishes a chronic infection, is rapidly cleared in C57Black/J mice with conditional deletion of Fas in DCs. The immune response to LCMV is characterized by an extended survival of virus-specific effector T cells. Moreover, transfer of Fas-negative DCs from non-infected mice to already-infected animals results in either complete clearance of the virus or a significant reduction of viral titers. Thus, DC-specific Fas expression plays a role in regulation of anti-viral responses and suggests a strategy for stimulation of T cells in chronically infected animals and humans in order to achieve the clearance of persistent viruses. We compared gene expression between splenic DCs from B6.FasKI and B6.CD11c-Cre.FasKI mice. DCs were isolated on day 5 after LCMV infection with 3 mice in each group, for a total of 6 samples. Spleens were collagenase-DNAse digested and sorted by flow to isolate DCs.
Project description:CD95L is expressed by tumor-infiltrating lymphocytes to eliminate CD95-expressing tumor cells and thereby CD95 loss by tumor cells is often considered as a consequence of an immunoediting process. Nonetheless CD95 expression is maintained in most triple negative breast cancers (TNBCs), and we recently reported that CD95 loss in TNBC cells triggers the induction of a pro-inflammatory program promoting the recruitment of cytotoxic NK and CD8+ T-cells and impairing tumor growth. Using a comprehensive proteomic approach, we have identified two yet unknown CD95 interaction partners, Kip1 ubiquitination-promoting complex protein 2 (KPC2) and p65. KPC2 contributes to the partial degradation of p105 (NFκB1) and the subsequent generation of p50 homodimers, which transcriptionally represses pro-inflammatory NF-κB-driven gene expression. Mechanistically, KPC2 directly interacts with the C-terminal region of CD95 and links the receptor to RelA (p65) and KPC1, the catalytic subunit of the KPC complex that acts as E3 ubiquitin-protein ligase promoting the partial degradation of p105 into p50. Loss of CD95 in TNBC cells releases KPC2, limiting the formation of the NF-κB inhibitory homodimer complex (p50/p50), promoting NF-κB activation and the production of pro-inflammatory cytokines including CSF1, CSF2, CXCL1 and IL1 members, known to promote recruitment and differentiation of certain adaptive and innate immune effector cells.
Project description:Chronic viral infections incapacitate adaptive immune responses by 'exhausting' virus-specific T cells, inducing their deletion and reducing productive T cell memory. Viral infection rapidly induces death receptor Fas (CD95) expression by dendritic cells (DCs) making them susceptible to elimination by the immune response. Lymphocytic Choriomeningitis Virus (LCMV) Clone 13, which normally establishes a chronic infection, is rapidly cleared in C57Black/J mice with conditional deletion of Fas in DCs. The immune response to LCMV is characterized by an extended survival of virus-specific effector T cells. Moreover, transfer of Fas-negative DCs from non-infected mice to already-infected animals results in either complete clearance of the virus or a significant reduction of viral titers. Thus, DC-specific Fas expression plays a role in regulation of anti-viral responses and suggests a strategy for stimulation of T cells in chronically infected animals and humans in order to achieve the clearance of persistent viruses.
Project description:LDHA is key enzyme for tumor glycolysis metabolism and knocking down LDHA would change a lot of gene expression We used microarrays to detail the global gene expression in 4T1 cells with LDHA knocked down by shRNA
Project description:CD95 (also called FAS and APO-1) is a prototypical death receptor that regulates tissue homeostasis mainly in the immune system through induction of apoptosis. During cancer progression CD95 is frequently downregulated or cells are rendered apoptosis resistant raising the possibility that loss of CD95 is part of a mechanism for tumour evasion. However, complete loss of CD95 is rarely seen in human cancers and many cancer cells express large quantities of CD95 and are highly sensitive to CD95 mediated apoptosis in vitro. Furthermore, cancer patients frequently have elevated levels of the physiological ligand for CD95, CD95L. These data raise the intriguing possibility that CD95 could actually promote the growth of tumours through its nonapoptotic activities. Here we show that cancer cells in general, regardless of their CD95 apoptosis sensitivity, depend on constitutive activity of CD95, stimulated by cancer-produced CD95L, for optimal growth. Consistently, loss of CD95 in mouse models of ovarian cancer and liver cancer reduces cancer incidence as well as the size of the tumours. The tumorigenic activity of CD95 is mediated by a pathway involving JNK and c-Jun. These results demonstrate that CD95 plays a major growth promoting role during tumorigenesis and suggest that efforts to inhibit its activity rather than to enhance its activation should be considered during cancer therapy. There are 3 arrays for human ovarian cancer cell line, 2 arrays for human liver cancer cell line, and 2 arrays for mouse liver tissue. All the arrays are paired arrays with or without Fas knock-out.
Project description:CD95 expression in triple negative breast cancer blocks induction of an inflammatory state through differential regulation of NF-κB Signaling [4T1]
Project description:In this project, 4T1 parental cells (4T1/WT) were exposed to increasing concentrations of epirubicin (EPB) to establish a novel multi-drug resistant CSC-like breast cancer cell line (4T1/EPB). The ubiquitinated proteins were enriched from 4T1/WT or 4T1/EPB derived cell lysate using a-Al2O3-Vx3 nanoparticles to produce the covalently linked product UPs nanovaccine. Label-free LC-MS/MS mass spectrometry was used to detect the type and amount of enriched proteins of UPs from the 4T1/WT cells and the 4T1/EPB cells.