scholarly journals Density of the Notch ligand Delta1 determines generation of B and T cell precursors from hematopoietic stem cells

2005 ◽  
Vol 201 (9) ◽  
pp. 1361-1366 ◽  
Author(s):  
Mari H. Dallas ◽  
Barbara Varnum-Finney ◽  
Colleen Delaney ◽  
Keizo Kato ◽  
Irwin D. Bernstein

Notch signaling regulates multiple cell fate decisions by hematopoietic precursors. To address whether different amounts of Notch ligand influence lineage choices, we cultured murine bone marrow lin−Sca-1+c-kit+ cells with increasing densities of immobilized Delta1ext-IgG consisting of the extracellular domain of Delta1 fused to the Fc domain of human IgG1. We found that relatively lower densities of Delta1ext-IgG enhanced the generation of Sca-1+c-kit+ cells, Thy1+CD25+ early T cell precursors, and B220+CD43−/lo cells that, when cocultured with OP9 stroma cells, differentiated into CD19+ early B cell precursors. Higher densities of Delta1ext-IgG also enhanced the generation of Sca-1+c-kit+ precursor cells and promoted the development of Thy1+CD25+ cells, but inhibited the development of B220+CD43−/lo cells. Analyses of further isolated precursor populations suggested that the enhanced generation of T and B cell precursors resulted from the effects on multipotent rather than lymphoid-committed precursors. The results demonstrate the density-dependent effects of Delta1 on fate decisions of hematopoietic precursors at multiple maturational stages and substantiate the previously unrecognized ability of Delta1 to enhance the development of both early B and T precursor cells.


Blood ◽  
2004 ◽  
Vol 104 (6) ◽  
pp. 1696-1702 ◽  
Author(s):  
Ivan Maillard ◽  
Andrew P. Weng ◽  
Andrea C. Carpenter ◽  
Carlos G. Rodriguez ◽  
Hong Sai ◽  
...  

Abstract During lymphoid development, Notch1 plays a critical role in the T-cell/B-cell lineage decision, while Notch2 is essential for marginal zone B-cell (MZB) development. Notch pathway activation induces translocation of intracellular Notch (ICN) to the nucleus, where it interacts with the transcription factor CSL (CBF1/RBP-Jk, Suppressor of Hairless, Lag-1). In vitro, ICN binds Mastermind-like proteins, which act as potent Notch coactivators. Three MAML family members (MAML1-3) have been identified in mammals, but their importance in vivo is unknown. To investigate the function of MAMLs in hematopoietic development, we introduced a dominant negative (DN) mutant of MAML1, capable of inhibiting Notch1-4, in murine hematopoietic stem cells. DNMAML1 resulted in early inhibition of T-cell development and the appearance of intrathymic B cells, phenotypes consistent with Notch1 inhibition. The T-cell differentiation block was as profound as that produced by enforced expression of the Notch modulator Deltex1. In DNMAML1-transduced spleen cells, a dramatic decrease in MZB cells was present, consistent with Notch2 inhibition. In contrast, Deltex1 did not decrease MZB cell numbers. These results suggest a critical role for MAMLs during Notch-mediated cell fate decisions in vivo and indicate that DNMAML1, but not Deltex1, can be used to interfere with the function of multiple Notch family members. (Blood. 2004;104:1696-1702)



Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1700-1700
Author(s):  
Mari H. Dallas ◽  
Colleen Delaney ◽  
Barbara Varnum-Finney ◽  
Irwin D. Bernstein

Notch signaling regulates multiple cell fate decisions by hematopoietic precursors. Previously, we found that endogenous Notch signaling in cultures of murine hematopoietic precursors (Lin-Sca-1+ c-Kit+) leads to a multi-log increase in the number of Sca-1+ c-Kit+ cells, inhibition of myeloid differentiation, and promotion of T/NK differentiation. To activate Notch signaling in those studies, a single dose (10μg/ml) of engineered Notch ligand consisting of the extracellular domain of Delta1 fused to the Fc domain of human IgG1 (Delta1ext-IgG) was immobilized to the plastic tissue culture surface. To investigate quantitative effects of Notch signaling, bone marrow Lin-Sca-1+ c-Kit+ (LSK) cells were cultured with plates coated with increasing concentrations of Delta1ext-IgG in media supplemented with 20% FBS, SCF (100 ng/mL), Flt3L (100 ng/mL), IL6 (100ng/mL) and IL11 (10ng/mL). LSK cells cultured for 14 days with control human IgG1 underwent terminal myeloid differentiation (determined by expression of GR1 and F4/80) with no further increase in cell number, whereas at all densities of Delta1ext-IgG there was approximately a 3 log greater number of cells than in control cultures. Furthermore, the portion of cells that maintained Sca-1 and c-Kit expression increased at greater densities of Delta1ext-IgG (10%, 32%, 77%, 71%, 71% and 71% for plates coated with ligand at 0.6, 1.25, 2.5, 5, 10 and 20 μg/ml, respectively, and 5% for human IgG1 control at 10μg/ml), whereas the portion of cells undergoing myeloid differentiation decreased at greater ligand densities (48%, 33%, 5%, 3%, 3% and 3% respectively, and 40% for control). In contrast, a substantial increase in the portion of cells expressing B220+ was observed at relatively low densities of Delta1ext-IgG (30% at 0.6 μg/ml and 19% at 1.25 μg/ml) compared to control (4%), but was no longer evident with further increases in ligand density (1.8%, 2%, 1.2%, m1.6% at 2.5, 5, 10 and 20 μg/ml respectively). Furthermore, promotion of early T cell differentiation was observed in ligand containing cultures with the generation of increased number of cells co-expressing Thy1.2 and CD25 (14%, 24%, 22% and 24% at 2.5, 5, 10 and 20 μg/ml respectively). Further evidence for T cell commitment was established by quantitative RT-PCR in which increased expression of CD3ε and pre-Tα was observed by 28 days of culture. Thus these studies demonstrate that culture with different densities of the Notch ligand, Delta1ext-IgG results in differential cell fate outcome with inhibition of myeloid differentiation and promotion of early T cell induction that is maximal at high ligand densities and of B220+ cells at relatively lower densities.



Blood ◽  
2003 ◽  
Vol 101 (11) ◽  
pp. 4342-4346 ◽  
Author(s):  
Claudiu V. Cotta ◽  
Zheng Zhang ◽  
Hyung-Gyoon Kim ◽  
Christopher A. Klug

Abstract Progenitor B cells deficient in Pax5 are developmentally multipotent, suggesting that Pax5 is necessary to maintain commitment to the B-cell lineage. Commitment may be mediated, in part, by Pax5 repression of myeloid-specific genes. To determine whether Pax5 expression in multipotential cells is sufficient to restrict development to the B-cell lineage in vivo, we enforced expression of Pax5 in hematopoietic stem cells using a retroviral vector. Peripheral blood analysis of all animals reconstituted with Pax5-expressing cells indicated that more than 90% of Pax5-expressing cells were B220+ mature B cells that were not malignant. Further analysis showed that Pax5 completely blocked T-lineage development in the thymus but did not inhibit myelopoiesis or natural killer (NK) cell development in bone marrow. These results implicate Pax5 as a critical regulator of B- versus T-cell developmental fate and suggest that Pax5 may promote commitment to the B-cell lineage by mechanisms that are independent of myeloid gene repression.



Blood ◽  
2008 ◽  
Vol 111 (5) ◽  
pp. 2615-2620 ◽  
Author(s):  
Barbara Varnum-Finney ◽  
Mari H. Dallas ◽  
Keizo Kato ◽  
Irwin D. Bernstein

Notch signaling establishes boundaries in the thymus by inducing T-cell commitment and inhibiting a B-cell choice. Here, we show a significant 1.6-fold increased generation of B-cell precursors in thymuses from mice deficient for Notch target Hes5 compared with wild-type littermates. We further show that culture of bone marrow–derived progenitors with increasing densities of purified immobilized Notch ligand (Delta1ext-IgG) induced increased expression of Notch targets Hes1 and Hes5, and that although Hes5-deficient progenitors responded appropriately to high densities of ligand, they misread intermediate and low densities. Together, our results suggest that to ensure an appropriate outcome in the thymus in response to a lower threshold of induced Notch signaling, induction of the additional target Hes5 is required.



Blood ◽  
2004 ◽  
Vol 104 (8) ◽  
pp. 2315-2322 ◽  
Author(s):  
Suzanne M. Vercauteren ◽  
Heather J. Sutherland

Abstract Notch transmembrane receptors are known to play a critical role in cell-fate decisions, with Notch1 shown to enhance self-renewal of hematopoietic stem cells and cause T-cell leukemia. Four Notch receptors exist, and the extent of redundancy and overlap in their function is unknown. Notch4 is structurally distinct from Notch1 through Notch3 and has not been extensively studied in hematopoiesis. By polymerase chain reaction (PCR) we find Notch4 transcript expression in human marrow cells and in both CD34+ and CD34– populations. When constitutively active Notch1 or Notch4 was overexpressed in normal human marrow or cord cells, we found reduced colony-forming and short-term proliferative ability while the primitive progenitor content of myeloid long-term cultures was significantly increased. Notch4–intracellular domain (Notch4-IC)–transduced cord cells transplanted into β2-microglobulin–/– nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice resulted in significantly higher levels of engraftment of both green fluorescent protein–positive (GFP+) and GFP– populations as compared with controls. GFP+ cells in bone marrow and spleen of animals that had received transplants gave rise to an immature CD4+CD8+ T-cell population, whereas B-cell development was blocked. These results indicate that activation of Notch4 results in enhanced stem cell activity, reduced differentiation, and altered lymphoid development, suggesting it may influence both stem cells and the fate of the common lymphoid progenitor.



2018 ◽  
Vol 115 (12) ◽  
pp. E2888-E2897 ◽  
Author(s):  
Simon Mitchell ◽  
Koushik Roy ◽  
Thomas A. Zangle ◽  
Alexander Hoffmann

Rapid antibody production in response to invading pathogens requires the dramatic expansion of pathogen-derived antigen-specific B lymphocyte populations. Whether B cell population dynamics are based on stochastic competition between competing cell fates, as in the development of competence by the bacterium Bacillus subtilis, or on deterministic cell fate decisions that execute a predictable program, as during the development of the worm Caenorhabditis elegans, remains unclear. Here, we developed long-term live-cell microscopy of B cell population expansion and multiscale mechanistic computational modeling to characterize the role of molecular noise in determining phenotype heterogeneity. We show that the cell lineage trees underlying B cell population dynamics are mediated by a largely predictable decision-making process where the heterogeneity of cell proliferation and death decisions at any given timepoint largely derives from nongenetic heterogeneity in the founder cells. This means that contrary to previous models, only a minority of genetically identical founder cells contribute the majority to the population response. We computationally predict and experimentally confirm nongenetic molecular determinants that are predictive of founder cells’ proliferative capacity. While founder cell heterogeneity may arise from different exposure histories, we show that it may also be due to the gradual accumulation of small amounts of intrinsic noise during the lineage differentiation process of hematopoietic stem cells to mature B cells. Our finding of the largely deterministic nature of B lymphocyte responses may provide opportunities for diagnostic and therapeutic development.



Blood ◽  
2007 ◽  
Vol 109 (8) ◽  
pp. 3579-3587 ◽  
Author(s):  
Mari H. Dallas ◽  
Barbara Varnum-Finney ◽  
Paul J. Martin ◽  
Irwin D. Bernstein

Abstract A physiologic role for Notch signaling in hematopoiesis has been clearly defined in lymphoid differentiation, with evidence suggesting a critical role in T-cell versus B-cell fate decisions. Previously, we demonstrated that activation of endogenous Notch receptors by culture of murine lin−Sca-1+c-kit+ (LSK) hematopoietic progenitors with exogenously presented Notch ligand, Delta1ext-IgG, consisting of the extracellular domain of Delta1 fused to the Fc domain of human IgG1, promoted early T-cell differentiation and increased the number of progenitors capable of short-term lymphoid and myeloid reconstitution. Here we show that culture of LSK precursors with Delta1ext-IgG increases the number of progenitors that are able to rapidly repopulate the thymus and accelerate early T-cell reconstitution with a diversified T-cell receptor repertoire. Most of the early T-cell reconstitution originated from cells that expressed lymphoid-associated antigens: B220, Thy1, CD25, and/or IL7Rα, whereas the most efficient thymic repopulation on a per cell basis originated from the smaller number of cultured cells that did not express lymphoid-associated antigens. These findings demonstrate the potential of Delta1ext-IgG-cultured cells for accelerating early immune reconstitution after hematopoietic cell transplantation.



2021 ◽  
Vol 11 ◽  
Author(s):  
Matthew Garis ◽  
Lee Ann Garrett-Sinha

The Notch signaling pathway is highly evolutionarily conserved, dictating cell fate decisions and influencing the survival and growth of progenitor cells that give rise to the cells of the immune system. The roles of Notch signaling in hematopoietic stem cell maintenance and in specification of T lineage cells have been well-described. Notch signaling also plays important roles in B cells. In particular, it is required for specification of marginal zone type B cells, but Notch signaling is also important in other stages of B cell development and activation. This review will focus on established and new roles of Notch signaling during B lymphocyte lineage commitment and describe the function of Notch within mature B cells involved in immune responses.



2018 ◽  
Author(s):  
Rajiv W Jain ◽  
Kate A Parham ◽  
Yodit Tesfagiorgis ◽  
Heather C Craig ◽  
Emiliano Romanchik ◽  
...  

AbstractB cell fate decisions within a germinal center (GC) are critical to determining the outcome of the immune response to a given antigen. Here, we characterize GC kinetics and B cell fate choices in a response to the autoantigen myelin oligodendrocyte glycoprotein (MOG), and compare them the response to a standard model foreign antigen (NP-haptenated ovalbumin, NPOVA). Both antigens generated productive primary responses, as evidenced by GC development, circulating antigen-specific antibodies, and differentiation of memory B cells. However, in the MOG response the status of the cognate T cell partner drove preferential B cell differentiation to a memory phenotype at the expense of GC maintenance, resulting in a truncated GC. Reduced plasma cell differentiation was largely independent of T cell influence. Interestingly, memory B cells formed in the MOG GC were unresponsive to secondary challenge and this could not be overcome with T cell help.



Blood ◽  
2001 ◽  
Vol 98 (13) ◽  
pp. 3793-3799 ◽  
Author(s):  
Xiao-Qiang Yan ◽  
Ulla Sarmiento ◽  
Yu Sun ◽  
Guo Huang ◽  
Jane Guo ◽  
...  

Abstract Notch receptors mediate cell-fate decisions through interaction with specific ligands during development. The biological role of a novel Notch ligand, Dll4, in mice was explored by reconstituting lethally irradiated mice with bone marrow (BM) cells transduced with Dll4 retroviral vector. White blood cell and lymphocyte counts in Dll4-overexpressing mice were reduced at the early stage of reconstitution but increased significantly at approximately 10 weeks after BM transplantation. BM, spleen, lymph nodes, and peripheral blood ofDll4-overexpressing mice contained predominantly CD4+CD8+ T cells and virtually lacked B cells. The Dll4-overexpressing mice eventually developed a lethal phenotype that was characterized by the progression of a T-cell lymphoproliferative disease (restricted to BM and lymphoid tissues) to transplantable monoclonal T-cell leukemia/lymphoma scattered to multiple organs. Results suggest that the interaction of Dll4with Notch1 may provide key signals for T-cell development.



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