The genome of vertebrates contains endogenous retroviruses (ERVs) that have resulted from ancestral infections by exogenous retroviruses. ERVs are germline encoded, transmitted in a Mendelian fashion and account for about 8% of the human and 9.9% of the murine genome, respectively1, 2. By spontaneous activation and reintegration ERVs may cause insertional mutagenesis and thus participate in the process of malignant transformation or progression of tumor growth3, 4. However, if the innate immune system is able to recognize and control ERVs has not yet been elucidated. Here we report that, in vitro, nucleic-acid sensing TLRs on dendritic cells are activated by retroviral RNA and DNA from infected cells in vitro. Infection of TLR competent wild type mice with murine leukemia virus (MuLV)-like ERV isolates results in non-canonical gene upregulation, independent of type I IFN. In vivo, TLR3, -7 and -9 triple deficient mice (TLR379-/-) and mice with non functional TLR3, 7 and 9 signaling due to a mutation in UNC93B develop spontaneous ERV-induced viremia. More importantly, in TLR379-/- mice ERV-induced viremia correlates with acute T cell lymphoblastic leukemia (T-ALL). Multiple independent TLR379-/- T cell leukemia lines produce infectious MuLV of endogenous origin. These cell lines display de novo retroviral integration into the Nup214 or Notch1 gene locus leading to gene dysregulation that is reminiscent of aberrant Nup214 and Notch1 expression in human T-ALLs5. Overall, our results demonstrate that in addition to their role in innate immune defense against exogenous pathogens, TLR3,-7, and -9 may be essential for the control of endogenous retroviral mediated T-cell lymphomagenesis.
Nucleic acid-sensing Toll-like receptors are essential for the control of endogenous retrovirus viremia and ERV-induced tumors.
Specimen part
View SamplesTo examine the impact of tumors on the immune system, we compared global gene expression profiles of peripheral blood T cells from previously untreated patients with B cell chronic lymphocytic leukemia (CLL) with those from age-matched healthy donors. Although the cells analyzed were not part of the malignant clone, analysis revealed differentially expressed genes, mainly involved in cell differentiation in CD4 cells and defects in cytoskeleton formation, vesicle trafficking, and cytotoxicity in CD8 cells of the CLL patients. In coculture experiments using CLL cells and T cells from healthy allogeneic donors, similar defects developed in both CD4 and CD8 cells. These changes were induced only with direct contact and were not cytokine mediated. Identification of the specific pathways perturbed in the T cells of cancer-bearing patients will allow us to assess steps to repair these defects, which will likely be required to enhance antitumor immunity.
Chronic lymphocytic leukemia cells induce changes in gene expression of CD4 and CD8 T cells.
No sample metadata fields
View SamplesWe explored the effects of dexamethasone and lenalidomide, individually and in combination, on the differentiation of primary human bone marrow progenitor cells in vitro. Both agents promote erythropoiesis, increasing the absolute number of erythroid cells produced from normal CD34+ cells and from CD34+ cells with the types of ribosome dysfunction found in DBA and del(5q) MDS. However, the drugs had distinct effects on the production of erythroid progenitor colonies; dexamethasone selectively increased the number burst-forming units-erythroid (BFU-E), while lenalidomide specifically increased colony-forming units-erythroid (CFU-E). Use of the drugs in combination demonstrates that their effects are not redundant.
Dexamethasone and lenalidomide have distinct functional effects on erythropoiesis.
Specimen part, Treatment
View SamplesWhole genome expression profiling in the presence and absence of annexin A2 [shRNA] identified fundamentally altered transcriptional programming that changes the radioresponsive transcriptome.
Annexin A2 modulates radiation-sensitive transcriptional programming and cell fate.
Treatment, Time
View SamplesIt has been shown that tumor infiltrating immune cells have a profound impact on the outcome of FL. To find mechanisms whereby TILs are altered gene expession analysis of highly pure TILs were performed.
Follicular lymphoma cells induce changes in T-cell gene expression and function: potential impact on survival and risk of transformation.
Specimen part, Subject
View SamplesTo compare the gene expression profiles of leukemia initiation cells of SALL4B transgenic mice and their control counterparts.
A SALL4/MLL/HOXA9 pathway in murine and human myeloid leukemogenesis.
Specimen part, Disease
View SamplesA549 cells were grown at air liquid interphase (ALI) and exposed to airborne formaldehyde for three days. An exposure platform was developed for this purpose, which provided the volatile analyte in a humidified atmosphere. The platform was composed of a reference and an exposure chamber.
Cellular reactions to long-term volatile organic compound (VOC) exposures.
Cell line
View SamplesMutations of RUNX1 are detected in patients with myelodysplastic syndrome (MDS). In particular, C-terminal truncation mutations lack a transcription regulatory domain and have increased DNA binding through the runt homology domain (RHD). The expression of the RHD, RUNX1(41-214), in mouse hematopoietic cells induced progression to MDS and acute myeloid leukemia (AML). Analysis of pre-myelodysplastic animals revealed expansion of c-Kit+Sca-1+Lin- (KSL) cells and skewed differentiation to myeloid at the expense of the lymphoid lineage. These abnormalities correlate with the phenotype of Runx1-deficient animals, as expected given the reported dominant-negative role of C-terminal mutations over the full-length RUNX1. However, MDS is not observed in Runx1-deficient animals. Gene expression profiling revealed that RUNX1(41-214) KSLs have an overlapping yet distinct gene expression profile from Runx1-deficient animals. Moreover, an unexpected parallel was observed between the hematopoietic phenotype of RUNX1(41-214) and aged animals. Genes deregulated in RUNX1(41-214), but not in Runx1-deficient animals, were inversely correlated with the aging gene signature of hematopoietic stem cells (HSC), suggesting that disruption of the expression of genes related to normal aging by RUNX1 mutations contributes to development of MDS. The data presented here provide insights into the mechanisms of development of MDS in HSCs by C-terminal mutations of RUNX1.
Expression of the runt homology domain of RUNX1 disrupts homeostasis of hematopoietic stem cells and induces progression to myelodysplastic syndrome.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
MYBL2 is a sub-haploinsufficient tumor suppressor gene in myeloid malignancy.
Specimen part, Disease, Disease stage
View SamplesA dosage-dependent role for tumor suppressor genes in the initiation of myeloid malignancies remains controversial. Here we show that MYBL2 is expressed at sharply reduced levels in CD34+ cells from most patients with myelodysplastic syndrome (MDS; 65%; n=26). In a murine competitive reconstitution model, Mybl2 knockdown by RNAi to 20-30% of normal levels in multipotent hematopoietic progenitors led to clonal dominance by these sub-haploinsufficient cells, affecting all blood cell lineages. By 6 months post-transplantation, the reconstituted mice had developed a myeloproliferative/myelodysplastic disorder originating from the cells with aberrantly reduced Mybl2 expression. Thus, downregulation of MYBL2 activity to levels below those predicted by classical haploinsufficiency drives the clonal expansion of hematopoietic progenitors in a large fraction of human MDS cases.
MYBL2 is a sub-haploinsufficient tumor suppressor gene in myeloid malignancy.
Specimen part, Disease, Disease stage
View Samples