ATAC-seq data from murine peripheral T-cell lymphoma and control normal T cells, NKT cells and NK cells
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ABSTRACT: Peripheral T-cell lymphomas (PTCLs) represent a significant unmet medical need with dismal clinical outcome.T-cell receptor (TCR) is emerging as a key driver of T lymphocytes transformation. However, the role of chronic TCR activation in lymphomagenesis and in survival of lymphoma cells is still poorly understood. Using an original mouse model, we report here that chronic TCR stimulation drives T-cell lymphomagenesis whereas TCR signaling does not contribute to PTCL survival. Epigenetic analyses of mouse PTCLs using ATAC-seq revealed a NK-like reprogramming of PTCL cells with increase accessibility to OCR associated with NK cells.
Project description:Peripheral T-cell lymphomas (PTCLs) represent a significant unmet medical need with dismal clinical outcome.T-cell receptor (TCR) is emerging as a key driver of T lymphocytes transformation. However, the role of chronic TCR activation in lymphomagenesis and in survival of lymphoma cells is still poorly understood. Using an original mouse model, we report here that chronic TCR stimulation drives T-cell lymphomagenesis whereas TCR signaling does not contribute to PTCL survival. Transcriptome analyses of mouse PTCLs revealed a NK-like reprogramming of PTCL cells with expression of NK receptors (NKRs) and downstream signaling molecules such as Tyrobp and Syk.
Project description:Peripheral T-cell lymphoma unspecified (PTCL/U), the most common form of PTCL, displays heterogeneous morphology and phenotype, poor response to treatment, and dismal prognosis. We demonstrate that PTCL/U shows a gene expression profile clearly distinct from that of normal T-cells. Comparison with the profiles of purified T-cell subpopulations [CD4+, CD8+, resting (HLA-DR-), and activated (HLA-DR+)] reveals that PTCLs/U are most closely related to activated peripheral T-lymphocytes, either CD4+ or CD8+. Interestingly, the global gene expression profile cannot be surrogated by routine CD4/CD8 immunohistochemistry. When compared with normal T-cells, PTCLs/U display deregulation of functional programs often involved in tumorigenesis (e.g. apoptosis, proliferation, cell adhesion, and matrix remodeling). Products of deregulated genes can be detected in PTCLs/U by immunohistochemistry with an ectopic, paraphysiologic or stromal location. Among others, PTCLs/U aberrantly express PDGFRA, a tyrosine-kinase receptor, whose deregulation is often related to a malignant phenotype. Notably, both phosphorylation of PDGFRA and sensitivity of cultured PTCL cells to imatinib (as well as to an inhibitor of histone-deacetylase) are found. These results, which might be extended to other rarer PTCL categories, are provided with implications for tumor pathogenesis and clinical management. Experiment Overall Design: 40 cases of Peripheral T-cell lymphoma (PTCL) were analyzed, including 28 PTCL/unspecified, 6 angioimmunoblastic (AITL) and 6 anaplastic large cell lymphoma cases (ALCL). Frozen lymph-nodes collected at diagnosis (before therapy) were used. In addition, 20 samples of normal T-cells (5 CD4+, 5 CD8+, 5 HLA-DR+, and 5 HLA-DR-) collected from peripheral blood and tonsils of healthy donors were studied. The HG U133 2.0 plus microarray (Affymetrix) was adopted.
Project description:Certain peripheral T-cell lymphomas (PTCLs) have been associated with viral infection, particularly infection with Epstein-Barr virus (EBV). However, a comprehensive virome analysis across PTCLs has not previously been reported, and viral gene expression profiles have been studied only in certain PTCL subtypes. In this study we utilized published RNA-seq data sets from seven different PTCL studies as well as new RNA-seq data from our laboratory to screen for virus association, to analyze viral gene expression, and to assess B- and T-cell receptor diversity paradigms across these tumor types. In addition to identifying EBV in angioimmunoblastic T-cell lymphoma (AITL) and extranodal NK/T cell lymphoma (ENKTL), two PTCL subtypes with well-established EBV associations, we also detected EBV in several cases of anaplastic large cell lymphoma (ALCL), and we found evidence of infection by the oncogenic viruses KSHV and HTLV-1 in isolated PTCL cases. In AITLs, EBV gene expression analysis showed expression of immediate early, early and late lytic genes, suggesting either abortive lytic replication and/or productive infection in a subset of the EBV infected infiltrating B-lymphocytes. Deconvolution of immune cell subpopulations demonstrated a greater B-cell signal in AITLs than in other PTCL subtypes, consistent with a larger role for B-cell support in the pathogenesis of AITL. T-cell receptor (TCR) and B-cell receptor (BCR) repertoires reconstructed from RNA-seq data demonstrated increased BCR diversity in AITLs, consistent with a possible EBV-driven polyclonal response. These findings indicate potential alternative roles for EBV in PTCLs in addition to the canonical oncogenic mechanisms associated with EBV latent infection. The findings also suggest the involvement of other viruses in T-cell lymphoma pathogenesis and demonstrate immunological alterations associated with these cancers.
Project description:Some infectious agents are associated with non-Hodgkin lymphoma development. Here we have used p53-deficient mice chronically injected with Streptococcus pneumoniae (Spn) with the aim to develop an animal model of infection-associated lymphomagenesis. We show that repeated stimulations with heat-killed Spn significantly enhanced the incidence of peripheral T-cell lymphoma (PTCL) in these mice. Phenotypic studies and gene expression profile analyses indicate that these PTCL arose from chronically stimulated natural killer T (NKT) cells, a T cell lineage that exhibits unique properties. Furthermore, lymphoma development was blocked when these PTCL were transferred to recipients lacking CD1d expression or treated with blocking CD1d mAbs, thus demonstrating that in vivo TCR/CD1d interactions are required for these PTCL survival. In conclusion, we have identified a new entity of peripheral T-cell lymphoma that originates from CD1d-restricted natural killer T (NKT) cells. Our results could refine the classification of PTCL and pave the way for the development of new immunotherapeutic approaches.
Project description:Peripheral T-cell lymphomas (PTCLs) are heterogenous T-cell neoplasms often associated with epigenetic dysregulation. We investigated de novo DNA methyltransferase 3A (DNMT3A) mutations in common PTCL entities, including angioimmunoblastic T-cell lymphoma and novel molecular subtypes identified within PTCL-not otherwise specified (PTCL-NOS) designated as PTCL-GATA3 and PTCL-TBX21. DNMT3A-mutated PTCL-TBX21 cases showed inferior overall-survival, with DNMT3A mutated residues skewed towards the methyltransferase domain and dimerization motif (S881–R887). Transcriptional profiling demonstrated significant enrichment of activated CD8+ T-cell cytotoxic gene signatures in the DNMT3A-mutant PTCL-TBX21 cases, which was further validated using immunohistochemistry. Genome-wide methylation analysis of DNMT3A-mutant versus wild-type PTCL-TBX21 cases demonstrated hypomethylation in target genes regulating IFN-g, TCR signaling and EOMES, a master transcriptional regulator of cytotoxic effector cells. Similar findings were observed in a murine model of PTCL with Dnmt3a loss (in-vivo) and further validated in-vitro by ectopic expression of DNMT3A-mutants (DNMT3A-R882, -Q886, -V716, versus WT) in CD8+T-cell line, resulting in T-cell activation and EOMES upregulation. Furthermore, stable, ectopic expression of the DNMT3A-mutants in primary CD3+ T-cell cultures resulted in the preferential outgrowth of CD8+ T-cells with DNMT3AR882H mutation. Single-cell-RNA-seq analysis of CD3+ T-cells revealed differential CD8+ T-cell subset polarization, mirroring findings in DNMT3A-mutated PTCL-TBX21 and validating the cytotoxic and T-cell memory transcriptional programs associated with the DNMT3AR882H mutation. Our findings indicate that DNMT3A mutations define a cytotoxic subset in PTCL-TBX21 with prognostic significance, thus may further refine pathological heterogeneity in PTCL-NOS and suggest alternative treatment strategies for this subset.
Project description:Peripheral T-cell lymphomas (PTCLs) are heterogenous T-cell neoplasms often associated with epigenetic dysregulation. We investigated de novo DNA methyltransferase 3A (DNMT3A) mutations in common PTCL entities, including angioimmunoblastic T-cell lymphoma and novel molecular subtypes identified within PTCL-not otherwise specified (PTCL-NOS) designated as PTCL-GATA3 and PTCL-TBX21. DNMT3A-mutated PTCL-TBX21 cases showed inferior overall-survival, with DNMT3A mutated residues skewed towards the methyltransferase domain and dimerization motif (S881–R887). Transcriptional profiling demonstrated significant enrichment of activated CD8+ T-cell cytotoxic gene signatures in the DNMT3A-mutant PTCL-TBX21 cases, which was further validated using immunohistochemistry. Genome-wide methylation analysis of DNMT3A-mutant versus wild-type PTCL-TBX21 cases demonstrated hypomethylation in target genes regulating IFN-g, TCR signaling and EOMES, a master transcriptional regulator of cytotoxic effector cells. Similar findings were observed in a murine model of PTCL with Dnmt3a loss (in-vivo) and further validated in-vitro by ectopic expression of DNMT3A-mutants (DNMT3A-R882, -Q886, -V716, versus WT) in CD8+T-cell line, resulting in T-cell activation and EOMES upregulation. Furthermore, stable, ectopic expression of the DNMT3A-mutants in primary CD3+ T-cell cultures resulted in the preferential outgrowth of CD8+ T-cells with DNMT3AR882H mutation. Single-cell-RNA-seq analysis of CD3+ T-cells revealed differential CD8+ T-cell subset polarization, mirroring findings in DNMT3A-mutated PTCL-TBX21 and validating the cytotoxic and T-cell memory transcriptional programs associated with the DNMT3AR882H mutation. Our findings indicate that DNMT3A mutations define a cytotoxic subset in PTCL-TBX21 with prognostic significance, thus may further refine pathological heterogeneity in PTCL-NOS and suggest alternative treatment strategies for this subset.
Project description:Peripheral T-cell lymphoma unspecified (PTCL/U), the most common form of PTCL, displays heterogeneous morphology and phenotype, poor response to treatment, and dismal prognosis. We demonstrate that PTCL/U shows a gene expression profile clearly distinct from that of normal T-cells. Comparison with the profiles of purified T-cell subpopulations [CD4+, CD8+, resting (HLA-DR-), and activated (HLA-DR+)] reveals that PTCLs/U are most closely related to activated peripheral T-lymphocytes, either CD4+ or CD8+. Interestingly, the global gene expression profile cannot be surrogated by routine CD4/CD8 immunohistochemistry. When compared with normal T-cells, PTCLs/U display deregulation of functional programs often involved in tumorigenesis (e.g. apoptosis, proliferation, cell adhesion, and matrix remodeling). Products of deregulated genes can be detected in PTCLs/U by immunohistochemistry with an ectopic, paraphysiologic or stromal location. Among others, PTCLs/U aberrantly express PDGFRA, a tyrosine-kinase receptor, whose deregulation is often related to a malignant phenotype. Notably, both phosphorylation of PDGFRA and sensitivity of cultured PTCL cells to imatinib (as well as to an inhibitor of histone-deacetylase) are found. These results, which might be extended to other rarer PTCL categories, are provided with implications for tumor pathogenesis and clinical management. Keywords: Molecular pathogenesis, molecular classification
Project description:Genome-wide analysis of nodal peripheral T-cell lymphomas (PTCL/NOS, AITL and ALCL) was used to identify molecular signatures corresponding to different subgroups. We also aimed to define the counterparts of PTCLs/NOS based on their global gene expression profiles. We developed a new molecular classifier able to distinct PTCL/NOS heterogeneity due to the correspondence to different counterparts.
Project description:A ï¾Cartes dï¾Identite des Tumeursï¾ (CIT) project from the french Ligue Nationale Contre le Cancer (http://cit.ligue-cancer.net) | Affymetrix HG-U133 Plus 2.0 : 17 AITL biopsies, 2 AITL sorted cells, 16 PTCL NOS biopsies | The molecular alterations underlying the pathogenesis of angioimmunoblastic T-cell lymphoma (AITL) and peripheral T-cell lymphoma, unspecified (PTCL-u) are largely unknown. In order to characterize the ontogeny and molecular differences between both entities, a series of AITLs (n = 18) and PTCLs-u (n = 16) was analyzed using gene expression profiling. Unsupervised clustering correlated with the pathological classification and with CD30 expression in PTCL-u. The molecular profile of AITLs was characterized by a strong microenvironment imprint (overexpression of B-cell- and follicular dendritic cell-related genes, chemokines, and genes related to extracellular matrix and vascular biology), and overexpression of several genes characteristic of normal follicular helper T (T(FH)) cells (CXCL13, BCL6, PDCD1, CD40L, NFATC1). By gene set enrichment analysis, the AITL molecular signature was significantly enriched in published T(FH)-specific genes. The enrichment was higher for sorted AITL cells than for tissue samples. Overexpression of several T(FH) genes was validated by immunohistochemistry in AITLs. A few cases with molecular T(FH)-like features were identified among CD30(-) PTCLs-u. Our findings strongly support that T(FH) cells represent the normal counterpart of AITL, and suggest that the AITL spectrum may be wider than suspected, as a subset of CD30(-) PTCLs-u may derive from or be related to AITL.| Submitter : Aurelien de Reynies <reyniesa@ligue-cancer.fr> | Project leader : Philippe Gaulard <philippe.gaulard@hmn.aphp.fr>