bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel Synthetic GMCSF and MCP3 Fusion Cytokine Induces IL10-Producing B Cells with Immune Modulatory Properties on Antigen Presentation and Th17 Development
Authors: Hsieh Hsiang-Chuan (Jeremy) , Williams Patrick , Rafei Moutih , Birman Elena , Young Yoon Now , Galipeau Jacques 
Published: October 2019

Abstract
Abstract 587
Therapeutic strategies based on the modulation of immune system can be exploited to treat a variety of pathologies including autoimmune diseases and cancer. We previously described the immune suppressive and receptor-specific apoptotic effect of a fusion cytokine GMME1, generated by the linkage of granulocyte macrophage-colony stimulating factor (GM-CSF) at the N-terminal of MCP1 (6-76). To better understand the immunobiology of N-terminal-modified CC chemokine, we described the novel function of GMCSF-MCP3 (5-76) (GMME3) in its induction of IL10+, regulatory-competent B cells. Ex vivo cultured B lymphocyte with GMME3 leads to a significant increase in S and G2/M phases, IL10 production and the expression of CD1.d and CD5. Treatment of experimental autoimmune encephalomyelitis (EAE) mice with GMME3-activated wild type B cells (BGMME3), but not IL10 null B cells, significantly inhibits the disease progression and immune infiltrates into the CNS. We demonstrated that the mechanism by which BGMME3 exerts their effect is through IL10-mediated inhibition of class II antigen presentation of macrophages; moreover, BGMME3 inhibits the reactivation of EAE-derived Th17 cells by augmenting Th1 pathway. Hence, N-terminal-GMCSF-fused CC chemokine, GMME3 modulates the immunological phenotype of B cells in a manner permissive for personalized cell therapy of autoimmune ailments.

Disclosures:
No relevant conflicts of interest to declare.
Dissecting the Mechanism of Apoptosis and Leukemic Transformation In Myelodysplasia
Authors: Slape Christopher I , Saw Jesslyn , Failla Laura M , Aplan Peter D , Jane Stephen M , Curtis David J 
Published: October 2019

Abstract
Abstract 610
A central question in the pathogenesis of the myelodysplastic syndromes (MDS) is the mechanism of apoptosis in early disease, and how this is overcome during disease progression to acute myeloid leukemia (AML). In humans, increased serum and bone marrow levels of TNF and/or FASL in early MDS implicate the cell-extrinsic apoptotic pathway, whereas increased expression of anti-apoptotic BCL2-related proteins (the cell-intrinsic pathway) has been linked to leukemic transformation. Here, we have employed the Vav-NUP98-HOXD13 (NHD13) transgenic mouse model to genetically dissect the molecular mechanisms underpinning apoptosis and leukemic progression in MDS. Three month old NHD13 mice recapitulate ‘low-risk’ human MDS with peripheral blood cytopenias, impaired in vitro progenitor cell growth, dysplasia of myeloid cells and megakaryocytes, and prominent apoptosis. Leukemic transformation in NHD13 mice occurs between 6 and 14 months of age. Using gene targeted mouse lines crossed with NHD13 mice, we show that neither TNF nor FasL are required for apoptosis. In contrast, enforced expression of Bcl2 rescues the early MDS phenotype including the macrocytic anemia, dysplasia of megakaryocytes, apoptosis and impaired erythroid and myeloid progenitor cell growth. Remarkably, enforced expression of Bcl2 completely prevented transformation to AML. Our results challenge many of the concepts regarding apoptosis in MDS. First, apoptosis is the predominant mechanism of peripheral cytopenias including erythroid-megakaryocyte dysplasia. Second, apoptosis is mediated by the BCL2-related cell intrinsic pathway. Third, overcoming apoptosis is unlikely to be an important mechanism of leukemic transformation. Indeed, our results extend recent evidence that apoptosis may be a ‘driver’ of leukemic transformation rather than a protective mechanism. These findings raise the therapeutic potential of BCL2 mimetic drugs for treating cytopenias and preventing leukemic transformation of MDS.

Disclosures:
No relevant conflicts of interest to declare.
Correction of the Fanconi Anemia Phenotype at the Cellular Level by S Phase Delay: Implications for Etiopathogenesis and Treatment
Authors: Lambert W. Clark , Centurion Santiago , Brown Monique 
Published: October 2019

Abstract
Abstract 879
Fanconi Anemia (FA) is a rare, complex, recessively inherited disease, with 13 known complementation groups, in which many patients develop bone marrow failure and/or leukemia, especially myelogenous leukemia, at an early age. Although bone marrow transplantation (BMT) has been beneficial, a high proportion of these patients go on to develop head and neck cancers and other solid malignancies, regardless of whether BMT has been carried out. Our laboratory, and others, have shown that FA is associated with a cell cycle defect in which FA cells fail to slow or arrest their rate of replicative, S-phase DNA synthesis as do normal cells following treatment with a DNA interstrand cross-linking (ICL) agent. FA cells are also markedly hypersensitive to the clastogenic and cytotoxic effects of such ICL agents, characteristics used to define the disease in the classic diepoxybutane, or DEB test. We wished to test whether, if the cell cycle defect were corrected by treating the cells with an inhibitor of DNA synthesis, the cytoclastic and cytotoxic effects of an ICL agent, psoralen plus ultraviolet A light (PUVA), would be affected in FA cells. Among DNA synthesis inhibitors, we were particularly interested in examining hydroxyurea and 5-fluorouracil (HU and 5-FU), because they have been used successfully to treat other blood diseases and cancers, respectively, such as sickle cell anemia and colon adenocarcinomas. Following treatment with PUVA, normal lymphoblastoid cells (two cell lines), FA lymphoblastoid cells (two FA-A, one FA-C and one FA-G lines), and two genetically corrected FA lymphoblastoid cell lines (FA-A and FA-C) were either mock treated or treated with an inhibitor of DNA synthesis (high dose thymidine, methotrexate, or HU) for 24 hours. Chromosome breaks and both short term (trypan blue exclusion) and long term cell viability (colony forming ability) were then measured. Except for one FA-A cell line that had low thymidine kinase activity, and therefore did not respond to thymidine, all uncorrected FA cell lines, but not corrected FA cell lines, showed dramatic reductions in clastogenicity and increases in viability following PUVA and treatment with any of the DNA synthesis inhibitors. Normal cells and corrected FA cells failed to show a comparable response.
These results indicate that the S-phase cell cycle defect in FA is important in its etiopathogenesis. The stalled DNA replication forks documented in FA cells containing DNA ICLs may actually be due, in part or entirely, to a prior defect in cell cycle regulation when damaged FA cells enter S phase. These results also suggest at least two possible modes of therapeutic intervention, treatment of FA patients with HU or 5-FU to prevent or delay onset of complications including bone marrow failure, leukemia, or, particularly in patients who have undergone BMT, head, neck, and other tumors.

Disclosures:
No relevant conflicts of interest to declare.
Noninvasive Prediction of Graft-Verus-Host Disease Following Allogeneic Hematopoietic Cell Transplantation by Gene Expression Profiling
Authors: Kohrt Holbrook E , Li Li , Alizadeh Ash A , Goldstein Matthew J , Strober Samuel , Sarwal Minnie , Lowsky Robert 
Published: October 2019

Abstract
Abstract 896

Background:
Chronic graft-versus-host disease (cGvHD) and immunosuppressive medications for its treatment result in significant morbidity and mortality, limiting the clinical benefit of allogeneic hematopoietic cell transplantation (HCT). A noninvasive, diagnostic and prognostic test is needed to determine which patients have active cGvHD at present and which subset will have active cGvHD in the future.

Methods:
We performed peripheral blood gene expression profiling to identify an array of transcriptional biomarkers that discriminate presence of active cGvHD requiring immunosuppression following allogeneic HCT. Peripheral blood mononuclear cells were prepared by Ficoll gradient and cryopreserved from 63 patients (median age 50 yrs; range 19–64) following allogeneic HCT (median 475 days post-HCT) on an IRB approved protocol. Samples were randomly selected into a training set (23 cGvHD and 19 without cGvHD) and test set (12 cGvHD and 9 without cGvHD) and processed on the Agilent whole human genome 44k microarray platform. Bioinformatics programs including AILUN, GeneSpring, SAM, and PAM were used to select a minimum gene-set (false discovery rate, FDR<5%) to predict cGvHD in the training set. Patient characteristics in the two groups were collected for confounder/interaction analysis across the following parameters: age, gender, disease histology, disease status at HCT, graft source, conditioning regimen, white blood count (WBC) at sample, and follow-up status including relapse and survival. Type, grade, and activity of acute GvHD and cGvHD at time of sample and at most recent follow-up were determined by two independent investigators by standard clinical criteria.

Results:
There is considerable heterogeneity among cGvHD patients, not attributable to multiple confounding factors, suggesting molecular heterogeneity in the development and progression of cGvHD. A minimum of 10 unique genes selected from SAM and PAM predict active cGvHD at the time of the peripheral blood sample with 95% sensitivity and 78% specificity in the training set, and 75% sensitivity and 78% specificity in the test set. Eight and four of ten genes are enriched in NK and CD4 T cells, respectively, and involved in the IL-10 signaling pathway (p<0.01). The 10 gene-set predicted the presence of active cGvHD at last follow-up (median 849 days post-HCT) with 85% sensitivity and 83% specificity.

Conclusion:
Peripheral blood gene expression across a 10 gene-set shows strong correlation of the predictive probability of cGvHD and the clinical phenotype. Given reasonable diagnostic sensitivity and specicifity for prediction of future cGvHD, additional longitudinal studies of this cohort and a prospective cohort are underway to further improve the accuracy of this approach and predictive power of this gene-set.

Disclosures:
No relevant conflicts of interest to declare.
MEF2C as Novel Oncogene for Early T-Cell Precursor (ETP) Leukemia
Authors: Homminga Irene , Pieters Rob , Langerak Anton , de Rooi Johan , Stubbs Andrew , Verstegen Monique , Vuerhard Maartje , Buijs-Gladdines Jessica , Kooi Clarissa , Klous Petra , Van lierberghe Pieter , Ferrando Adolfo , Cayuela Jean-Michel , Verhaaf Brenda , Beverloo Berna , Horstmann Martin A. , de Haas Valerie , Wiekmeijer Anna-Sophia , Pike-Overzet Karin , Staal Frank , de Laat Wouter , Soulier Jean , Sigaux Francois , Meijerink Jules 
Published: October 2019

Abstract
Abstract 9
To identify novel oncogenic pathways in T-cell acute lymphoblastic leukemia (T-ALL), we combined expression profiling of 117 pediatric patient samples and detailed molecular cytogenetic analyses. Using unsupervised and supervised analyses, we identified a T-ALL cluster that was associated with an immature immunophenotype (CD1−, CD4−, CD8−), frequent expression of CD34 and co-expression of the myeloid markers CD13/CD33. Patients in this cluster lacked any of the known oncogenic rearrangements, but ectopically expressed MEF2C, which was recently demonstrated as an important transcription factor for T-cell development1. Molecular-cytogenetic analyses including the Chromatine Conformation Capture on Chip (4C) method revealed novel rearrangements of the MEF2C locus at 5q14, rearrangement of transcription factors that target MEF2C (PU.1, NKX2-5, RUNX1) or MEF2C-associated cofactors (NCOA2/GRIP1) in about half of the patients in this cluster. Four out of the 6 rearrangements identified have never been observed before in human cancer. Nearly all of these patients in this cluster could be predicted by the early T-cell precursor (ETP) signature2 using PAM statistics. This indicates that MEF2C may represent the oncogene for ETP T-ALL, an entity that has been associated with poor outcome2. Inhibition of MEF2C in a cell line model system provoked relieve of developmental arrest, indicating that ectopic MEF2C expression blocks T-cell development at an early stage. We demonstrated that MEF2C is a transcriptional regulator for many differentially expressed genes that were associated with the immature cluster including LYL1 and LMO2. Although LYL1 has been suggested as potential oncogene for immature T-ALL cases3, oncogenic rearrangements were never identified in T-ALL cases with immature immunophenotype. Our data therefore imply that high expression of LYL1 (and LMO2) is part of a pathogenic pathway for immature T-ALL that is regulated by the MEF2C oncogene.
1 Stehling-Sun, S., Dade, J., Nutt, S. L., DeKoter, R. P. & Camargo, F. D. Regulation of lymphoid versus myeloid fate ’choice’ by the transcription factor Mef2c. Nat Immunol 10, 289–296, (2009).
2 Coustan-Smith, E. et al. Early T-cell precursor leukaemia: a subtype of very high-risk acute lymphoblastic leukaemia. Lancet Oncol 10, 147–156, (2009).
3 Ferrando, A. A. et al. Gene expression signatures define novel oncogenic pathways in T cell acute lymphoblastic leukemia. Cancer Cell 1, 75–87 (2002).

Disclosures:
No relevant conflicts of interest to declare.
In Vivo Roles for Factor XII
Authors: Renné Thomas 
Published: October 2019

Abstract
Abstract SCI-19
The coagulation system is critical for limiting blood loss at a site of injury (hemostasis), but may also contribute to thrombotic disease. The model of a coagulation balance represents these two sides of the same coin. Thrombosis may occur in the venous or arterial circulation, causing pulmonary embolism or myocardial infarction and stroke, collectively the most common causes of death in the developed world.
Recent data from genetically altered mouse models have challenged the dogma of a coagulation balance. Deficiency of coagulation factor XII (Hageman factor), a serine protease, which initiates the intrinsic pathway of coagulation, severely impairs thrombus formation but is not associated with any excessive bleedings in humans or in mice. Targeting factor XII protects from occlusive disease in experimental animal models. Individuals with hereditary deficiency in the factor XII substrate factor XI are largely protected form ischemic stroke and deep-vein thrombosis. These findings indicate that fibrin-forming mechanisms, which operate during pathologic thrombus formation, involve pathways distinct from those proceeding during normal hemostasis. As the factor XII-driven contact system selectively contributes to thrombosis, but not to hemostasis, inhibition of the system offers novel anticoagulation strategies associated with minimal or no bleeding risk. In contrast to factor XII deficiency states, a single missense mutation (Thr328Lys) in the coagulation protein is associated with a life-threatening swelling disease, hereditary angioedema type III. Pharmacological factor XII inhibitors interfered both with pathological thrombosis and edema formation suggesting broad medical implications.
Factor XII is activated in vivo by platelet-released inorganic polyphosphate, a linear polymer of 60–100 phosphate residues that directly bound to the coagulation factor. Polyphosphates-driven factor XII activation triggered release of the inflammatory mediator bradykinin. Polyphosphates increased vascular permeability and induced skin edema formation in mice and animals deficient in factor XII or bradykinin receptors were resistant to polyphosphates-induced leakage. Polyphosphates were procoagulant via the intrinsic pathway of coagulation. Ablation of intrinsic coagulation pathway proteases factors XII and XI protected mice from polyphosphate-triggered lethal pulmonary embolism. Targeting polyphosphates with phosphatases interfered with procoagulant activity of activated platelets and blocked platelet-induced thrombosis in mice. Addition of polyphosphates restored defective plasma clotting of Hermansky-Pudlak Syndrome patients, who platelet lack storage organelles for polyphosphates. The data identify polyphosphates as the endogenous activator of factor XII having fundamental roles in platelet-driven proinflammatory and procoagulant disorders.

Disclosures:
No relevant conflicts of interest to declare.
Gemtuzumab Ozogamicin as Post-Consolidation Therapy Does Not Prevent Relapse In Children with AML. Results of the NOPHO-AML 2004 Study
Authors: Hasle Henrik , Abrahamsson Jonas , Forestier Erik , Ha Shau-Yin , Heldrup Jesper , Jahnukainen Kirsi , Jonsson Olafur G , Lausen Birgitte , Palle Josefine , Zeller Bernward 
Published: October 2019

Abstract
Abstract 1534
There are no data on the role of post-consolidation therapy with gemtuzumab ozogamicin, (GO, Mylotarg) in children with AML. The NOPHO-AML 2004 protocol included two induction courses and four consolidation courses followed by a post-consolidation randomization to GO or no further therapy (ClinicalTrials.gov identifier NCT00476541).
GO was administered as 5 mg/m2 four weeks after last consolidation and repeated once after three weeks. We randomized 120 patients; 59 to receive GO, 61 to no further therapy. The children in the two groups had similar distribution of sex, age, WBC, and cytogenetics. Treatment was given as randomized in 113 (94% of the patients). Survival was analyzed on an intention to treat basis. The median follow-up for patients alive was 3.2 years (range 0.9 – 7.0).
Toxicity data from the children who received GO showed modest elevation of transaminase and bilirubin but without signs of VOD. No significant decrease in hemoglobin was observed whereas severe neutropenia occurred in 96% of the patients. Recovery to neutrophils > 0.5 lasted a median of 15 days. Febrile neutropenia followed 39% of the GO courses but none were life-threatening. A moderate decline in platelet count was noted with platelets < 50 × 109/L in 27% and transfusion was given following 11% of the GO courses.
Relapse occurred in 22 and 23 of those randomized to GO or no further therapy, respectively. The median time to relapse was 16 months in GO treated vs. 10 months in those receiving no GO (n.s.) (figure). Therapy-related MDS developed in two patients treated with GO. The 3-year EFS and OS in those randomized to receive GO vs. no further therapy was 54% vs. 63% (n.s.) and 75% vs. 84% (n.s.), respectively. The results were similar in all subgroups analyzed.
In conclusion GO therapy post consolidation was well tolerated with severe neutropenia, modest thrombocytopenia and no clinical liver toxicity. GO did not change the frequency of relapses but there was a non-significant delay in the time to relapse from 10 to 16 months for patients randomized to GO.

Disclosures:
Hasle: Pfizer: Research Funding. Off Label Use: A randomized study of gemtuzumab ozagamicin in childhood AML is presented.
MRx102, a Novel Triptolide Analogue, Has Low Nanomolar Activity Against AML Stem/Progenitor Cells in Vitro and in a Murine Model of AML
Authors: Carter Bing Z , Mak Duncan H , Shi Yuxie , Fidler John M. , Chen Rong , Ling Xiaoyang , Plunkett William , Andreeff Michael 
Published: October 2019

Abstract
Abstract 1547
Current chemotherapeutic regimens are known to be ineffective against AML stem/progenitor cells that is responsible for disease relapses due to both intrinsic resistance of these cells and extrinsic environmental factors. Triptolide, isolated from the herb Tripterygium wilfordii, has been shown to potently inhibit growth and induce apoptosis in various malignant cells by inhibiting RNA synthesis and NF-κB activity. Previously, we showed that triptolide promotes apoptosis in AML cells via the mitochondria-mediated pathway, in part by decreasing levels of the anti-apoptotic proteins XIAP and Mcl-1. MRx102 is a novel triptolide derivative, acting by converting to triptolide. We investigated whether MRx102 effectively targets primary human AML cells, particularly AML stem/progenitor cells co-cultured with bone marrow (BM) derived mesenchymal stromal cells (MSCs), and examined the effects of MRx102 in NOD/SCID mice injected with Ba/F3-ITD cells. We show here that MRx102 potently promoted apoptosis in AML cell lines, with EC50 values of low nanomolars for OCI-AML3 and MV4-11 cells. Like triptolide, MRx102 decreased XIAP and Mcl-1 protein levels and inhibited RNA synthesis in OCI-AML3 cells. Interestingly, we also found that MRx102 and triptolide decreased β-catenin protein level in OCI-AML3 cells. MRx102 effectively induced apoptosis in all primary AML samples tested, regardless of the cytogenetics or clinical responses to various therapies of the patients at the time of sampling (ED50 = 132.1 ± 7.5 nM, n=12) and was less toxic to normal BM cells (ED50 = 209.9 ± 56.8 nM, n=3). In addition to bulk AML cells, MRx102 also induced apoptosis in CD34+ progenitors, and more importantly in CD34+CD38− stem/progenitor cells from AML patients, even when they were protected by co-culturing with BM-derived MSCs. The effectiveness of MRx102 on AML stem/progenitor cells may be in part due to its ability to decrease β-catenin and triptolide's ability to inhibit NF-κB activity as both Wnt/β-catenin and NF-κB are highly active in AML stem/progenitor cells. Furthermore, in vivo, MRx102 greatly decreased leukemic burden, reduced infiltration of leukemic cells to various organs, and increased survival of NOD/SCID mice harboring Ba/F3-ITD cells (median survival 43 days with MRx102 at 3.0 mg/kg/day compared with 36 days for the untreated mice, P = 0.027).
Collectively, we demonstrated that MRx102 has strong antileukemic activity both in vitro and in vivo in a murine model of AML, has the potential to eliminate AML stem/progenitor cells and overcome microenvironmental protection of leukemic cells, and warrants clinical investigation.

Disclosures:
Fidler: MyeloRx LLC: Employment.