The 4662 KPC model is one of the most widely used mouse models of pancreatic cancer. It represents an excluded immune phenotype and closely recapitulates the pathophysiology of pancreatic cancer in humans. We set out to identify the endogenous neoepitopes present in 4662 cells.
View Article and Find Full Text PDFIntracellular recognition of self and non-self -nucleic acids can result in the initiation of effective pro-inflammatory and anti-tumorigenic responses. We hypothesized that macrophages can be activated by tumor-derived nucleic acids to induce inflammasome activation in the tumor microenvironment. We show that tumor conditioned media (CM) can induce IL-1β production, indicative of inflammasome activation in primed macrophages.
View Article and Find Full Text PDFJ Immunother Cancer
June 2022
Background: Dendritic cells (DCs) are professional antigen presenting cells that initiate immune defense to pathogens and tumor cells. Human tumors contain only few DCs that mostly display a non-activated phenotype. Hence, activation of tumor-associated DCs may improve efficacy of cancer immunotherapies.
View Article and Find Full Text PDFCell Death Differ
November 2021
Dysfunction of adipocytes and adipose tissue is a primary defect in obesity and obesity-associated metabolic diseases. Interferon regulatory factor 3 (IRF3) has been implicated in adipogenesis. However, the role of IRF3 in obesity and obesity-associated disorders remains unclear.
View Article and Find Full Text PDFDeficiencies in DNA repair and DNA degrading nucleases lead to accumulation of cytosolic DNA. cGAS is a critical DNA sensor for the detection of cytosolic DNA and subsequent activation of the STING signaling pathway. Here, we show that the cGAS-STING pathway was unresponsive to STING agonists and failed to induce type I interferon (IFN) expression in many tested human tumor cells including DU145 prostate cancer cells.
View Article and Find Full Text PDFBased on the success of tumor-infiltrating lymphocytes (TIL)-based therapies, personalized adoptive cell therapies (ACT) targeting neoantigens have the potential to become a disruptive technology and lead to highly effective treatments for cancer patients for whom no other options exist. ACT of TIL, peripheral blood or gene-engineered peripheral blood lymphocytes (PBLs) targeting neoantigens is a highly personalized intervention that requires three discrete steps: i) Identification of suitable personal targets (neoantigens), ii) selection of T cells or their T cell receptors (TCRs) that are specific for the identified neoantigens and iii) expansion of the selected T cell population or generation of sufficient number of TCR modified T cells. In this review, we provide an introduction into challenges and approaches to identify neoantigens and to select the Adoptive Cell Therapy, ACT, Neoantigen, T cell, Cancer respective neoantigen-reactive T cells for use in ACT.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
July 2020
is the causative agent of melioidosis, an infectious disease in the tropics and subtropics with high morbidity and mortality. The facultative intracellular bacterium induces host cell fusion through its type VI secretion system 5 (T6SS5) as an important part of its pathogenesis in mammalian hosts. This allows it to spread intercellularly without encountering extracellular host defenses.
View Article and Find Full Text PDFRecent success in immunomodulating strategies in lung cancer and melanoma has prompted much enthusiasm in their potential to treat other advanced solid malignancies. However, their applications have shown variable success and are even ineffective against some tumours. The efficiency of immunotherapies relies on an immunogenic tumour microenvironment.
View Article and Find Full Text PDFThe presence of damaged and microbial DNA can pose a threat to the survival of organisms. Cells express various sensors that recognize specific aspects of such potentially dangerous DNA. Recognition of damaged or microbial DNA by sensors induces cellular processes that are important for DNA repair and inflammation.
View Article and Find Full Text PDFCancer Immunol Res
April 2016
Apoptosis is a controlled means of eliminating damaged cells without causing an inflammatory response or tissue damage. The mechanisms that contribute to the suppression of an inflammatory response upon apoptosis of cells are poorly understood. Here, we report that apoptotic cells release the interleukin-1 receptor antagonist (IL1RA).
View Article and Find Full Text PDFPrimary cells are derived directly from tissue and are thought to be more representative of the physiological state of cells in vivo than established cell lines. However, primary cell cultures usually have a finite life span and need to be frequently re-established. Fibroblasts are an easily accessible source of primary cells.
View Article and Find Full Text PDFWe recently provided evidence that genome-derived DNA is present in the cytosol of many tumor cells. Genomic loci that give rise to cytosolic DNA can potentially form non-B DNA structures including triple-stranded RNA:DNA structures (R-loops). The RNA:DNA-specific endonuclease RNaseh1 reduced the levels of cytosolic DNA and type I interferon-dependent rejection of B-cell lymphoma suggesting that cytosolic DNA may contribute to immune surveillance of B-cell lymphoma.
View Article and Find Full Text PDFThe DNA damage response (DDR) induces the expression of type I interferons (IFNs), but the underlying mechanisms are poorly understood. Here, we show the presence of cytosolic DNA in different mouse and human tumor cells. Treatment of cells with genotoxic agents increased the levels of cytosolic DNA in a DDR-dependent manner.
View Article and Find Full Text PDFRNA:DNA hybrids form in the nuclei and mitochondria of cells as transcription-induced R-loops or G-quadruplexes, but exist only in the cytosol of virus-infected cells. Little is known about the existence of RNA:DNA hybrids in the cytosol of virus-free cells, in particular cancer or transformed cells. Here, we show that cytosolic RNA:DNA hybrids are present in various human cell lines, including transformed cells.
View Article and Find Full Text PDFOncoimmunology
February 2021
The DNA damage response (DDR) upregulates the expression of NKG2D ligands (NKG2DLs). We have recently reported that the DDR also induces the presence of cytosolic DNA in B-cell lymphoma cells, which leads to the activation of STING-dependent cytosolic DNA sensor pathways and the expression of RAE-1 ligands for NKG2D.
View Article and Find Full Text PDFClin Cancer Res
July 2014
The immunoreceptor NKG2D originally identified in natural killer (NK) cells recognizes ligands that are upregulated on tumor cells. Expression of NKG2D ligands (NKG2DL) is induced by the DNA damage response (DDR), which is often activated constitutively in cancer cells, revealing them to NK cells as a mechanism of immunosurveillance. Here, we report that the induction of retinoic acid early transcript 1 (RAE1) ligands for NKG2D by the DDR relies on a STING-dependent DNA sensor pathway involving the effector molecules TBK1 and IRF3.
View Article and Find Full Text PDFThe natural killer (NK) group 2 member D (NKG2D) is an activating immune receptor expressed on NK cells, cytotoxic T cells and a subset of other T cells. It has an important role in the recognition and lysis of a variety of infected and tumor cells. Despite significant gains in our understanding of NKG2D, the relevance of NKG2D and its ligands in human diseases has only recently started to emerge.
View Article and Find Full Text PDFThe DNA damage response (DDR) alerts the immune system to the danger posed by DNA damage through the induction of damage-associated molecular pattern molecules, chemokines, and ligands for activating immune receptors such as lymphocyte function-associated antigen 1 (LFA-1), NKG2D, and DNAX accessory molecule 1 (DNAM-1). Here we provide evidence that OVA(257-264) -pulsed fibroblasts gain the ability to activate naïve OT-I CD8(+) T cells in response to DNA damage. The ability of fibroblasts to activate OT-I CD8(+) T cells depended on the upregulation of ICAM-1 on fibroblasts and DNAM-1 expression of CD8(+) T cells.
View Article and Find Full Text PDFTLRs play a pivotal role in the recognition of bacteria and viruses. Members of the family recognize specific pathogen sequences to trigger both MyD88 and TRIF-dependent pathways to stimulate a plethora of cells. Aberrant activation of these pathways is known to play a critical role in the development of autoimmunity and cancer.
View Article and Find Full Text PDFOncoimmunology
June 2013
The DNA damage response (DDR), which is frequently activated in cancer cells, has been proposed to operate as an early barrier against oncogenesis. We have recently shown that ATM mediates the spontaneous regression of Eμdriven murine B-cell leukemia in a natural killer and T cell-dependent manner. The DDR partially enhanced immune recognition by stimulating the expression of the DNAM-1 ligand CD155.
View Article and Find Full Text PDFEvasion of apoptosis is a hallmark of cancer cells. Inhibitor of apoptosis proteins (IAPs) act as endogenous inhibitors of programmed cell death and are overexpressed in several tumors including Hodgkin lymphoma (HL). Preclinical studies indicate antitumor activity of IAP antagonists and clinical studies in hematological malignancies are underway.
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