| 1. |
- Somasundaram, Rajesh, et al.
(författare)
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EBF1 and PAX5 control pro-B cell expansion via opposing regulation of the Myc gene
- 2021
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 137:22, s. 3037-3049
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Tidskriftsartikel (refereegranskat)abstract
- Genes encoding B lineage–restricted transcription factors are frequently mutated in B-lymphoid leukemias, suggesting a close link between normal and malignant B-cell development. One of these transcription factors is early B-cell factor 1 (EBF1), a protein of critical importance for lineage specification and survival of B-lymphoid progenitors. Here, we report that impaired EBF1 function in mouse B-cell progenitors results in reduced expression of Myc. Ectopic expression of MYC partially rescued B-cell expansion in the absence of EBF1 both in vivo and in vitro. Using chromosome conformation analysis in combination with ATAC-sequencing, chromatin immunoprecipitation–sequencing, and reporter gene assays, six EBF1-responsive enhancer elements were identified within the Myc locus. CRISPR-Cas9–mediated targeting of EBF1-binding sites identified one element of key importance for Myc expression and pro-B cell expansion. These data provide evidence that Myc is a direct target of EBF1. Furthermore, chromatin immunoprecipitation–sequencing analysis revealed that several regulatory elements in the Myc locus are targets of PAX5. However, ectopic expression of PAX5 in EBF1-deficient cells inhibits the cell cycle and reduces Myc expression, suggesting that EBF1 and PAX5 act in an opposing manner to regulate Myc levels. This hypothesis is further substantiated by the finding that Pax5 inactivation reduces requirements for EBF1 in pro–B-cell expansion. The binding of EBF1 and PAX5 to regulatory elements in the human MYC gene in a B-cell acute lymphoblastic leukemia cell line indicates that the EBF1:PAX5:MYC regulatory loop is conserved and may control both normal and malignant B-cell development.
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| 2. |
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| 3. |
- Abolhassani, H, et al.
(författare)
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Current genetic landscape in common variable immune deficiency
- 2020
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Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 135:9, s. 656-667
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Tidskriftsartikel (refereegranskat)abstract
- Using whole-exome sequencing to examine the genetic causes of immune deficiency in 235 common variable immunodeficiency (CVID) patients seen in the United States (Mount Sinai, New York), 128 patients from Sweden, and 208 from Iran revealed 68 known disease-causing genes underlying this heterogeneous immune defect. The patients at the time of study ranged from 4 to 90 years of age. Overall, 31%, 36%, and 54% of the patients in the US, Swedish, or Iranian cohorts had mutations. The multiplicity of genes identified in the 571 subjects reflects the complex requirements of B-cell antigen signaling, activation, survival, migration, maturation, and maintenance of antibody-secreting memory B-cell populations to the plasma cell stage. For the US and Swedish cohorts, CVID subjects with noninfectious complications, lymphoid infiltrations, inflamatory conditions, or autoimmunity were somewhat more likely to have an identifiable gene, but in both cohorts, numerous subjects with these medical conditions had no potential gene that could be assigned. Specific clinical patterns of illnesses were also not linked to any given gene defect as there was considerable overlap in clinical presentations. These observations led to a new perspective on the complexity of the immunologic phenotype found in CVID syndrome.
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| 4. |
- Abonia, J Pablo, et al.
(författare)
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Alpha-4 integrins and VCAM-1, but not MAdCAM-1, are essential for recruitment of mast cell progenitors to the inflamed lung
- 2006
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 108:5, s. 1588-1594
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Tidskriftsartikel (refereegranskat)abstract
- Normal mouse lungs lack appreciable numbers of mast cells (MCs) or MC progenitors (MCp's), yet the appearance of mature MCs in the tracheobronchial epithelial surface is a characteristic of allergic, T-cell-dependent pulmonary inflammation. We hypothesized that pulmonary inflammation would recruit MCp's to inflamed lungs and that this recruitment would be regulated by distinct adhesion pathways. Ovalbumin-sensitized and challenged mice had a greater than 28-fold increase in the number of MCp's in the lungs. In mice lacking endothelial vascular cell adhesion molecule 1 (VCAM-1) and in wild-type mice administered blocking monoclonal antibody (mAb) to VCAM-1 but not to mucosal addressin CAM-1 (MadCAM-1), recruitment of MCp's to the inflamed lung was reduced by greater than 75%. Analysis of the integrin receptors for VCAM-1 showed that in beta7 integrin-deficient mice, recruitment was reduced 73% relative to wild-type controls, and in either BALB/c or C57BL/6 mice, mAb blocking of alpha4, beta1, or beta7 integrins inhibited the recruitment of MCp's to the inflamed lung. Thus, VCAM-1 interactions with both alpha4beta1 and alpha4beta7 integrins are essential for the recruitment and expansion of the MCp populations in the lung during antigen-induced pulmonary inflammation. Furthermore, the MCp is currently unique among inflammatory cells in its partial dependence on alpha4beta7 integrins for lung recruitment.
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| 5. |
- Abrahamsson, Anna, et al.
(författare)
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Real world data on primary treatment for mantle cell lymphoma: a Nordic Lymphoma Group observational study.
- 2014
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Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 124:8, s. 1288-1295
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Tidskriftsartikel (refereegranskat)abstract
- There is consensus that young patients with mantle cell lymphoma (MCL) should receive intensive immunochemotherapy regimens, but optimal treatment of elderly patients as well for as patients with limited or indolent disease is not defined. Our aim was to evaluate and compare outcome in relation to prognostic factors and first-line treatment in patients with MCL in a population-based data set. Data were collected from the Swedish and Danish Lymphoma Registries from the period of 2000-2011. A total of 1389 patients were diagnosed with MCL. During this period, age-standardized incidence MCL increased, most prominently among males. Furthermore, male gender was associated with inferior overall survival (OS) in multivariate analysis (HR 1.36; p=0.002). Forty-three (3.6%) patients with stage I-II disease received radiotherapy with curative intent, showing a 3 year OS of 93%. Twenty-nine (2.4%) patients followed a watch-and-wait approach and showed a 3 year OS of 79.8%. Among patients receiving systemic treatment, rituximab (n=766; HR 0.66; p=0.001) and autologous stem cell transplant (ASCT) (n=273; HR 0.55; p=0.004) were independently associated with improved overall survival in multivariate analysis. Hence, by a population-based approach, we were able to provide novel data on prognostic factors and primary treatment of MCL, applicable to routine clinical practice.
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| 6. |
- Abramson, JS, et al.
(författare)
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Lisocabtagene maraleucel as second-line therapy for large B-cell lymphoma: primary analysis of the phase 3 TRANSFORM study
- 2023
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Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 141:14, s. 1675-1684
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Tidskriftsartikel (refereegranskat)abstract
- This global, phase 3 study compared lisocabtagene maraleucel (liso-cel) with standard of care (SOC) as second-line therapy for primary refractory or early relapsed (≤12 months) large B-cell lymphoma (LBCL). Adults eligible for autologous stem cell transplantation (ASCT) were randomized 1:1 to liso-cel (100×106 CAR+ T cells) or SOC (3 cycles of platinum-based immunochemotherapy followed by high-dose chemotherapy and ASCT in responders). The primary end point was event-free survival (EFS) by independent review. A total of 184 patients were randomized. In this primary analysis with a median follow-up of 17.5 months, median EFS was not reached (NR) for liso-cel versus 2.4 months for SOC (hazard ratio [HR] = 0.356; 95% confidence interval [CI]: 0.243‒0.522). Complete response (CR) rate was 74% for liso-cel versus 43% for SOC (P < .0001) and median progression-free survival (PFS) was NR for liso-cel versus 6.2 months for SOC (HR = 0.400; 95% CI: 0.261‒0.615; P < .0001). Median overall survival was NR for liso-cel versus 29.9 months for SOC (HR = 0.724; 95% CI: 0.443‒1.183; P = .0987). When adjusted for crossover from SOC to liso-cel, median overall survival was NR for liso-cel and SOC (HR = 0.415; 95% CI: 0.251‒0.686). Grade 3 cytokine release syndrome and neurological events occurred in 1% and 4% of patients in the liso-cel arm, respectively (no grade 4/5 events). These data show significant improvements in EFS, CR rate, and PFS for liso-cel over SOC and support liso-cel as a preferred second-line treatment compared with SOC in patients with primary refractory or early relapsed LBCL. (ClinicalTrials.gov; NCT03575351.)
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| 7. |
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| 8. |
- Agar, Cetin, et al.
(författare)
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beta(2)-Glycoprotein I: a novel component of innate immunity
- 2011
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Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 117:25, s. 6939-6947
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Tidskriftsartikel (refereegranskat)abstract
- Sepsis is a systemic host response to invasive infection by bacteria. Despite treatment with antibiotics, current mortality rates are in the range of 20%-25%, which makes sepsis the most important cause of death in intensive care. Gram-negative bacteria are a prominent cause of sepsis. Lipopolysaccharide (LPS), one of the major constituents of the outer membrane of Gram-negative bacteria, plays a major role in activating the host's immune response by binding to monocytes and other cells. Several proteins are involved in neutralization and clearance of LPS from the bloodstream. Here, we provide evidence that beta(2)-glycoprotein I (beta(2)GPI) is a scavenger of LPS. In vitro, beta(2)GPI inhibited LPS-induced expression of tissue factor and IL-6 from monocytes and endothelial cells. Binding of beta(2)GPI to LPS caused a conformational change in beta(2)GPI that led to binding of the beta(2)GPI-LPS complex to monocytes and ultimately clearance of this complex. Furthermore, plasma levels of beta(2)GPI were inversely correlated with temperature rise and the response of inflammatory markers after a bolus injection of LPS in healthy individuals. Together, these observations provide evidence that beta(2)GPI is involved in the neutralization and clearance of LPS and identify beta(2)GPI as a component of innate immunity. (Blood. 2011;117(25):6939-6947)
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| 9. |
- Agar, Cetin, et al.
(författare)
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beta(2)-Glycoprotein I can exist in 2 conformations: implications for our understanding of the antiphospholipid syndrome
- 2010
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Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 116:8, s. 1336-1343
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Tidskriftsartikel (refereegranskat)abstract
- The antiphospholipid syndrome is defined by the presence of antiphospholipid antibodies in blood of patients with thrombosis or fetal loss. There is ample evidence that beta(2)-glycoprotein I (beta(2)GPI) is the major antigen for antiphospholipid antibodies. The autoantibodies recognize beta(2)GPI when bound to anionic surfaces and not in solution. We showed that beta(2)GPI can exist in at least 2 different conformations: a circular plasma conformation and an "activated" open conformation. We also showed that the closed, circular conformation is maintained by interaction between the first and fifth domain of beta(2)GPI. By changing pH and salt concentration, we were able to convert the conformation of beta(2)GPI from the closed to the open conformation and back. In the activated open conformation, a cryptic epitope in the first domain becomes exposed that enables patient antibodies to bind and form an antibody-beta(2)GPI complex. We also demonstrate that the open conformation of beta(2)GPI prolonged the activated partial thromboplastin time when added to normal plasma, whereas the activated partial thromboplastin time is further prolonged by addition of anti-beta(2)GPI antibodies. The conformational change of beta(2)GPI, and the influence of the autoantibodies may have important consequences for our understanding of the antiphospholipid syndrome. (Blood. 2010; 116(8): 1336-1343)
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| 10. |
- Agathangelidis, A, et al.
(författare)
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Higher-order connections between stereotyped subsets: implications for improved patient classification in CLL
- 2021
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Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 137:10, s. 1365-1376
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Tidskriftsartikel (refereegranskat)abstract
- Chronic lymphocytic leukemia (CLL) is characterized by the existence of subsets of patients with (quasi)identical, stereotyped B-cell receptor (BcR) immunoglobulins. Patients in certain major stereotyped subsets often display remarkably consistent clinicobiological profiles, suggesting that the study of BcR immunoglobulin stereotypy in CLL has important implications for understanding disease pathophysiology and refining clinical decision-making. Nevertheless, several issues remain open, especially pertaining to the actual frequency of BcR immunoglobulin stereotypy and major subsets, as well as the existence of higher-order connections between individual subsets. To address these issues, we investigated clonotypic IGHV-IGHD-IGHJ gene rearrangements in a series of 29 856 patients with CLL, by far the largest series worldwide. We report that the stereotyped fraction of CLL peaks at 41% of the entire cohort and that all 19 previously identified major subsets retained their relative size and ranking, while 10 new ones emerged; overall, major stereotyped subsets had a cumulative frequency of 13.5%. Higher-level relationships were evident between subsets, particularly for major stereotyped subsets with unmutated IGHV genes (U-CLL), for which close relations with other subsets, termed “satellites,” were identified. Satellite subsets accounted for 3% of the entire cohort. These results confirm our previous notion that major subsets can be robustly identified and are consistent in relative size, hence representing distinct disease variants amenable to compartmentalized research with the potential of overcoming the pronounced heterogeneity of CLL. Furthermore, the existence of satellite subsets reveals a novel aspect of repertoire restriction with implications for refined molecular classification of CLL.
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