scholarly journals Blueprint of human thymopoiesis reveals molecular mechanisms of stage-specific TCR enhancer activation

2020 ◽  
Vol 217 (9) ◽  
Author(s):  
Agata Cieslak ◽  
Guillaume Charbonnier ◽  
Melania Tesio ◽  
Eve-Lyne Mathieu ◽  
Mohamed Belhocine ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
T Cell ◽  
Molecular Mechanisms ◽  
Lymphoblastic Leukemia ◽  
Ectopic Expression ◽  
Regulatory Elements ◽  
T Cell Differentiation ◽  
Epigenetic Changes ◽  
Human T Cell ◽  
Cell Commitment

Cell differentiation is accompanied by epigenetic changes leading to precise lineage definition and cell identity. Here we present a comprehensive resource of epigenomic data of human T cell precursors along with an integrative analysis of other hematopoietic populations. Although T cell commitment is accompanied by large scale epigenetic changes, we observed that the majority of distal regulatory elements are constitutively unmethylated throughout T cell differentiation, irrespective of their activation status. Among these, the TCRA gene enhancer (Eα) is in an open and unmethylated chromatin structure well before activation. Integrative analyses revealed that the HOXA5-9 transcription factors repress the Eα enhancer at early stages of T cell differentiation, while their decommission is required for TCRA locus activation and enforced αβ T lineage differentiation. Remarkably, the HOXA-mediated repression of Eα is paralleled by the ectopic expression of homeodomain-related oncogenes in T cell acute lymphoblastic leukemia. These results highlight an analogous enhancer repression mechanism at play in normal and cancer conditions, but imposing distinct developmental constraints.

scholarly journals Enhanced differentiation of functional human T cells in NSGW41 mice with tissue-specific expression of human interleukin-7

2020 ◽  
Author(s):  
Emilie Coppin ◽  
Bala Sai Sundarasetty ◽  
Susann Rahmig ◽  
Jonas Blume ◽  
Nikita A. Verheyden ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Differentiation ◽  
T Cell ◽  
Regulatory Elements ◽  
T Cell Differentiation ◽  
Human Immune System ◽  
Specific Expression ◽  
Hematopoietic Stem ◽  
Human T Cell ◽  
Human T Cells

AbstractHumanized mouse models have become increasingly valuable tools to study human hematopoiesis and infectious diseases. However, human T cell differentiation remains inefficient. We generated mice expressing human interleukin (IL-7), a critical growth and survival factor for T cells, under the control of murine IL-7 regulatory elements. After transfer of human cord blood-derived hematopoietic stem and progenitor cells, transgenic mice on the NSGW41 background, termed NSGW41hIL7, showed elevated and prolonged human cellularity in the thymus while maintaining physiological ratios of thymocyte subsets. As a consequence, numbers of functional human T cells in the periphery were increased without evidence for pathological lymphoproliferation or aberrant expansion of effector or memory-like T cells. We conclude that the novel NSGW41hIL7 strain represents an optimized mouse model for humanization to better understand human T cell differentiation in vivo and to generate a human immune system with a better approximation of human lymphocyte ratios.

scholarly journals The spleen as a sanctuary site for residual leukemic cells following ABT-199 monotherapy in ETP-ALL

2021 ◽  
Vol 5 (7) ◽  
pp. 1963-1976
Author(s):  
Alessandra Di Grande ◽  
Sofie Peirs ◽  
Paul D. Donovan ◽  
Maaike Van Trimpont ◽  
Julie Morscio ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
T Cell ◽  
Residual Disease ◽  
Lymphoblastic Leukemia ◽  
B Cell Lymphoma ◽  
T Cell Differentiation ◽  
Leukemic Cells ◽  
Human T Cell

Abstract B-cell lymphoma 2 (BCL-2) has recently emerged as a therapeutic target for early T-cell progenitor acute lymphoblastic leukemia (ETP-ALL), a high-risk subtype of human T-cell ALL. The major clinical challenge with targeted therapeutics, such as the BCL-2 inhibitor ABT-199, is the development of acquired resistance. We assessed the in vivo response of luciferase-positive LOUCY cells to ABT-199 monotherapy and observed specific residual disease in the splenic microenvironment. Of note, these results were confirmed by using a primary ETP-ALL patient-derived xenograft. Splenomegaly has previously been associated with poor prognosis in diverse types of leukemia. However, the exact mechanism by which the splenic microenvironment alters responses to specific targeted therapies remains largely unexplored. We show that residual LOUCY cells isolated from the spleen microenvironment displayed reduced BCL-2 dependence, which was accompanied by decreased BCL-2 expression levels. Notably, this phenotype of reduced BCL-2 dependence could be recapitulated by using human splenic fibroblast coculture experiments and was confirmed in an in vitro chronic ABT-199 resistance model of LOUCY. Finally, single-cell RNA-sequencing was used to show that ABT-199 triggers transcriptional changes in T-cell differentiation genes in leukemic cells obtained from the spleen microenvironment. Of note, increased expression of CD1a and sCD3 was also observed in ABT199-resistant LOUCY clones, further reinforcing the idea that a more differentiated leukemic population might display decreased sensitivity toward BCL-2 inhibition. Overall, our data reveal the spleen as a site of residual disease for ABT-199 treatment in ETP-ALL and provide evidence for plasticity in T-cell differentiation as a mechanism of therapy resistance.

scholarly journals Enhanced differentiation of functional human T cells in NSGW41 mice with tissue-specific expression of human interleukin-7

Leukemia ◽  
2021 ◽  
Author(s):  
Emilie Coppin ◽  
Bala Sai Sundarasetty ◽  
Susann Rahmig ◽  
Jonas Blume ◽  
Nikita A. Verheyden ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Differentiation ◽  
T Cell ◽  
Regulatory Elements ◽  
T Cell Differentiation ◽  
Human Immune System ◽  
Hematopoietic Stem ◽  
Interleukin 7 ◽  
Human T Cell ◽  
Human T Cells

AbstractHumanized mouse models have become increasingly valuable tools to study human hematopoiesis and infectious diseases. However, human T-cell differentiation remains inefficient. We generated mice expressing human interleukin-7 (IL-7), a critical growth and survival factor for T cells, under the control of murine IL-7 regulatory elements. After transfer of human cord blood-derived hematopoietic stem and progenitor cells, transgenic mice on the NSGW41 background, termed NSGW41hIL7, showed elevated and prolonged human cellularity in the thymus while maintaining physiological ratios of thymocyte subsets. As a consequence, numbers of functional human T cells in the periphery were increased without evidence for pathological lymphoproliferation or aberrant expansion of effector or memory-like T cells. We conclude that the novel NSGW41hIL7 strain represents an optimized mouse model for humanization to better understand human T-cell differentiation in vivo and to generate a human immune system with a better approximation of human lymphocyte ratios.

scholarly journals HTLV-1 induces T cell malignancy and inflammation by viral antisense factor-mediated modulation of the cytokine signaling

2020 ◽  
Vol 117 (24) ◽  
pp. 13740-13749 ◽  
Author(s):  
Yusuke Higuchi ◽  
Jun-ichirou Yasunaga ◽  
Yu Mitagami ◽  
Hirotake Tsukamoto ◽  
Kazutaka Nakashima ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Differentiation ◽  
T Cell ◽  
Transgenic Mice ◽  
Regulatory T Cell ◽  
T Cell Differentiation ◽  
Cytokine Signaling ◽  
Viral Gene ◽  
Cell Leukemia Virus Type ◽  
Human T Cell

Human T cell leukemia virus type 1 (HTLV-1) is the etiologic agent of a T cell neoplasm and several inflammatory diseases. A viral gene, HTLV-1 bZIP factor (HBZ), induces pathogenic Foxp3-expressing T cells and triggers systemic inflammation and T cell lymphoma in transgenic mice, indicating its significance in HTLV-1–associated diseases. Here we show that, unexpectedly, a proinflammatory cytokine, IL-6, counteracts HBZ-mediated pathogenesis. Loss of IL-6 accelerates inflammation and lymphomagenesis in HBZ transgenic mice. IL-6 innately inhibits regulatory T cell differentiation, suggesting that IL-6 functions as a suppressor against HBZ-associated complications. HBZ up-regulates expression of the immunosuppressive cytokine IL-10. IL-10 promotes T cell proliferation only in the presence of HBZ. As a mechanism of growth promotion by IL-10, HBZ interacts with STAT1 and STAT3 and modulates the IL-10/JAK/STAT signaling pathway. These findings suggest that HTLV-1 promotes the proliferation of infected T cells by hijacking the machinery of regulatory T cell differentiation. IL-10 induced by HBZ likely suppresses the host immune response and concurrently promotes the proliferation of HTLV-1 infected T cells.

scholarly journals Modulated expression of notch1 during thymocyte development

Blood ◽  
1996 ◽  
Vol 88 (3) ◽  
pp. 970-976 ◽  
Author(s):  
RP Hasserjian ◽  
JC Aster ◽  
F Davi ◽  
DS Weinberg ◽  
J Sklar
Keyword(s):  
Cell Differentiation ◽  
T Cell ◽  
Flow Cytometric Analysis ◽  
T Cell Differentiation ◽  
Thymocyte Development ◽  
Cd8 Cells ◽  
Flow Cytometric ◽  
Human T Cell ◽  
Weak Staining ◽  
Notch Gene

Abstract The Notch gene family encodes transmembrane proteins that have been implicated in control of diverse cellular differentiation events in the fly, frog, and mouse. Mammalian Notch1 is expressed at high levels in thymus and is mutated in a subset of human T-cell acute lymphoblastic neoplasms, suggesting a role in T-cell differentiation. To investigate the patterns of expression of NOTCH1 protein in thymocytes of the developing and mature thymus, antibodies raised against NOTCH1 were used to perform immunohistochemical and flow cytometric analyses. Strong staining for NOTCH1 within the fetal murine thymus was observed as early as 13.5 days postcoitum. By 17.5 days postcoitum, preferential staining of superficial cortical thymocytes was observed, with weak staining of developing medulla. Flow cytometric analysis and immunohistochemical staining of flow-sorted cells confirmed that the highest levels of NOTCH1 expression in adult murine thymus were present in immature cortical thymocytes (CD24high, CD4-CD8-). In contrast, NOTCH1 expression was low or absent in more mature cortical thymocytes (CD24low, CD4+CD8+), whereas intermediate levels of expression were observed in CD4+CD8- and CD4-CD8+ cells. These data indicate a dynamic pattern of NOTCH1 expression during T-cell differentiation and suggest that downregulation of NOTCH1 may be required for maturation of cortical thymocytes.

Human T Cell Differentiation: New Techniques, Old Challenges

2010 ◽  
pp. 351-371
Author(s):  
Jean Plum ◽  
Magda De Smedt ◽  
Georges Leclercq ◽  
Bart Vandekerckhove ◽  
Tom Taghon
Keyword(s):  
Cell Differentiation ◽  
T Cell ◽  
T Cell Differentiation ◽  
New Techniques ◽  
Human T Cell

Cyclin D2 Dysregulation by Chromosomal Translocations to TCR Loci in T-Cell Acute Lymphoblastic Leukemia (T-ALL).

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2073-2073
Author(s):  
Emmanuelle Clappier ◽  
Wendy Cuccuini ◽  
Jean-Michel Cayuela ◽  
Danielle Vecchione ◽  
Andre Baruchel ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Acute Lymphoblastic Leukemia ◽  
T Cell ◽  
Lymphoblastic Leukemia ◽  
T Cell Differentiation ◽  
Chromosomal Translocations ◽  
Genomic Rearrangements ◽  
Cyclin D2 ◽  
Cell Acute Lymphoblastic Leukemia ◽  
Normal Human

Abstract D-type cyclins are key regulators of progression through G1 phase of the cell cycle. Strong expression of at least one of the three D cyclins is common in human cancers. However, while the cyclin D1 and D3 genes (CCND1 and CCND3) are recurrently involved in genomic rearrangements, especially in mantle-cell lymphoma and multiple myeloma, no clear involvement of the cyclin D2 gene (CCND2) has been reported to date in human malignancies. In T-cell acute lymphoblastic leukemia (T-ALL), the T-cell receptor genes TCRA/D and TCRB are frequently involved in chromosomal rearrangements. In order to identify new genomic rearrangements and oncogenes in human T-ALL, we performed an interphasic FISH screening of T-ALL cases using TCR flanking probes. Using this approach, we identified two new chromosomal translocations: t(7;12)(q34;p13) and t(12;14)(p13;q11), involving the TCRB and TCRA/D loci, respectively. Molecular analysis of the breakpoint sequences demonstrated the involvement of the CCND2 locus at 12p13. Expression analysis using RQ-PCR and immunoblotting demonstrated dramatic cyclin D2 overexpression in the translocated cases (n=3) compared to other T-ALLs (total, n=86), whereas other genes located near the translocation breakpoints were not deregulated on microarray analysis. To further evaluate expression in T-ALL with respect to normal T-cell differentiation, we analyzed CCND2 expression in purified subpopulations from normal human thymus. CCND2 levels were downregulated through progression from the early stages of normal human T-cell differentiation and transition to beta-selection. In the most immature T-ALLs, a moderate CCND2 expression was observed, consistent with their differentiation stage, while low expression was found in other T-ALL. By contrast, the massive and sustained expression in the CCND2-rearranged T-ALL cases strongly suggested an oncogenic role due to the TCR translocation. T-ALL oncogenesis is a multi-step process; we here found that the TCR-CCND2 translocations were associated with other oncogene expression (TAL1, HOXA, or TLX3/HOX11L2), NOTCH1 activating mutations, and/or CDKN2A/p16/ARF deletion, showing that cyclin D2 dysregulation could contribute to multi-event oncogenesis in various T-ALL groups. In conclusion, this report is the first clear evidence of a direct involvement of cyclin D2 in human cancer due to recurrent somatic genetic alterations. This reinforces the view that the strong expression of cyclin D2 which is detected in various types of cancer can contribute to oncogenesis, and points to cyclin D2 as a potential target for therapy in these tumors.

scholarly journals T cell differentiation stages identified by molecular and immunologic analysis of the T cell receptor complex in childhood lymphoblastic leukemia

Blood ◽  
1987 ◽  
Vol 69 (3) ◽  
pp. 908-912 ◽  
Author(s):  
J Jr Mirro ◽  
G Kitchingman ◽  
FG Behm ◽  
SB Murphy ◽  
RM Goorha
Keyword(s):  
Cell Differentiation ◽  
T Cell ◽  
T Cell Receptor ◽  
Lymphoblastic Leukemia ◽  
Cell Receptor ◽  
T Cell Differentiation ◽  
Receptor Complex ◽  
Beta Chain ◽  
Alpha Chain ◽  
Beta Chain Genes

Abstract T cell differentiation was investigated by determining the relationship of T cell receptor (Ti) gene rearrangement and transcription to the expression of surface and cytoplasmic T3 antigen using blast cells from five children with acute lymphoblastic leukemia of thymic origin. Patterns of monoclonal antibody (MoAb) reactivity indicated that these cases were representative of the three recognized stages (I, II, III) of human thymocyte development. The T3 antigen, which becomes linked to the Ti to form a functional T cell receptor complex on mature thymocytes, was expressed on the cell surface in two cases (stage III). However, in the remaining three cases that were surface T3 negative (stages I and II), large amounts of T3 were identified in the cytoplasm by immunoperoxidase staining and flow cytometry. Leukemic blasts from all five patients showed rearranged genes encoding the beta-chain portion of the Ti heterodimer. RNA transcripts of Ti beta-chain genes were also evident in lymphoblasts from all five cases, but transcripts coding for the alpha-chain portion of Ti were found only in cases that expressed T3 on the cell surface. Thus the absence of surface T3 (and presumably Ti) coincides with the absence of Ti alpha-chain RNA, suggesting that transcription of alpha-chain genes is a critical regulatory event in the surface expression of the Ti-T3 complex. Leukemic T cells that rearrange and express Ti beta-chain genes but lack Ti alpha-chain messenger RNA (mRNA) may represent a stage of differentiation analogous to pre-B cells, where heavy-chain immunoglobulin (Ig) genes are rearranged and expressed but light-chain Ig genes are not expressed.

Inclusion of HOXA Genes in Genetic and Biological Networks Defining Human Acute T-Cell Leukemia.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1110-1110
Author(s):  
Jean Soulier ◽  
Emmanuelle Clappier ◽  
Jean-Michel Cayuela ◽  
Armelle Regnault ◽  
Marina Garcia-Peydro ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cell ◽  
Gene Cluster ◽  
Expression Analysis ◽  
Large Scale ◽  
Lymphoblastic Leukemia ◽  
Ectopic Expression ◽  
Molecular Networks ◽  
Human T Cell ◽  
Hoxa Genes

Abstract We have identified a new recurrent chromosomal translocation, targeting the major homeobox gene cluster HOXA in human T-cell acute lymphoblastic leukemia (T-ALL). Four cases were characterized using a combination of FISH, Southern blot, breakpoint region sequencing, and a large scale expression analysis of a series of T-ALL. Specific RQ-PCR analysis of the HOXA1 to HOXA13 transcripts showed that the whole HOXA gene cluster expression was dramatically deregulated in the HOXA-rearranged cases, and also in the MLL and CALM-AF10-related T-ALL, strongly suggesting that HOXA genes are oncogenic in these types of leukemia. The HOXA-rearranged cases were included in a general portrait of T-ALL based on large scale expression analysis, showing that a new homogeneous T-ALL subgroup is defined by this chromosomal rearrangement. Moreover, patterns of gene expression associated to the distinct T-ALL oncogenic subgroups were compared with gene expression in normal human thymic sub-populations (11 purified sub-populations). Inappropriate use or perturbation of some specific molecular networks involved in thymic differentiation could be detected in the T-ALL cells. Also, we found that abnormal, frequently ectopic, expression of at least one developmental gene, including HOXA, TLX1/HOX11, TLX3/HOX11L2 and a few more, could be identified in most of the T-ALL cases. Our data strongly support the view that the abnormal expression of developmental genes, including the prototypical major homeobox genes HOXA in some cases, is critical in T-ALL oncogenesis.

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