bluuebunny/crossref_metadata_2025_split huggingface dataset:
Icsbp/Irf8 Cooperates with Tel to Regulate Fas Induced Apoptosis in Myeloid Leukemia.
Authors: Huang Weiqi , Eklund Elizabeth A. 
Published: October 2019

Abstract
Abstract 395
The interferon consensus sequence binding protein (Icsbp) is an interferon regulatory transcription factor (also known as Irf8) which functions as an anti-oncogene for chronic myeloid leukemia (CML) and acute myeloid leukemia (AML). In previous studies we used chromatin immunoprecipitation based high through put screening approaches to identify Icsbp target genes which explain these effects. The identified set of target genes was enriched for genes encoding proteins which regulate cytokine induced proliferation, beta catenin activity, and Fas induced apoptosis. In further investigations of the latter category, we found that Icsbp represses transcription of PTPN13; the gene encoding Fas associated phosphatase 1 (Fap1). Fap1 binds directly to the C-terminus of Fas, resulting in Fas-dephosphorylation and antagonizing Fas-induced apoptosis. We found that repression of PTPN13 by Icsbp increased during myelopoiesis, resulting in decreased Fap1 expression and increased sensitivity to Fas-induced apoptosis as differentiation proceeds. In the current studies, we investigated the mechanism for Icsbp induced PTPN13 repression. We identified a multi-protein repression complex which includes Icsbp, the ets protein Tel, and Hdac3 which binds to a PTPN13 cis element in a manner requiring recognition of the binding site by Tel. We found that histone deacetylase activity of Hdac3 was essential for PTPN13 repression by this complex. Tel was first identified due to participation in a leukemia associated chromosomal translocation with the gene encoding the PdgfRβ. This translocation is characteristic of Chronic Myelomonocytic Leukemia (CMMoL) and results in expression of a fusion protein with the protein-protein interaction domain of Tel and the kinase domain of PdgfRβ. Tel/PdgfRβ fusion protein exhibits constitutive tyrosine kinase activity due to autophosphorylation and activation of fusion protein dimers. This results in transduction of proliferative signals in the absence of cytokine. In this work we identify another function for the Tel/PdgfRβ fusion protein which may also contribute to the pathogenesis of leukemia. We find that Tel/PdgfRβ fusion protein interacts with wild type Tel protein in the cell (expressed by the allele not involved in the translocation), consistent with results of previous investigators. More importantly, we find that interaction with Tel/PdgfRβ renders Tel unavailable for binding to the PTPN13 cis element, which prevents assembly of the Tel/Icsbp/Hdac3 repression complex. The net result is increased PTPN13 promoter activity and Fap1 expression in cells expressing Tel/PdgfRβ fusion protein. This increase in Fap1 expression contributes to resistance to Fas-induced apoptosis in these cells. Therefore, our studies identify a previously unrecognized mechanism for apoptosis resistance in CMMoL and a potential target for therapeutic intervention in this myelodysplastic/ myeloproliferative disorder.

Disclosures:
No relevant conflicts of interest to declare.
Non-MTC IGH-CCND1 Breakpoints in Mantle Cell Lymphoma Are Associated with CpG Sites and AID Hotspots
Authors: Greisman Harvey A , Lu Zhengfei , Tsai Albert G , Greiner Timothy C. , Yi Hye Son , Lieber Michael R. 
Published: October 2019

Abstract
Abstract 398
Most t(11;14)(q13;q32) breakpoints in mantle cell lymphoma (MCL) are scattered across a large genomic region centromeric to the CCND1 gene on chromosome 11q13. However, few t(11;14) breakpoints outside the major translocation cluster (MTC) have been sequenced. We report our analysis of 56 IGH-CCND1 fusion sequences from 32 non-MTC cases of MCL. Our analysis reveals remarkable breakpoint diversity at both CCND1 and IGH loci. The CCND1 breakpoints are located from 2 kb to 331 kb from the CCND1 gene, including 12 breakpoints (38%) in the 220kb region centromeric to the MTC, which is itself located 110 kb centromeric to the CCND1 gene. Twenty-one cases had a JH coding end breakpoint on the der(14) chromosome and a DH coding end breakpoint on the der(11). Two cases had der(14) and der(11) breakpoints derived from the coding and signal ends of the same JH or DH gene segment; one case had a JH/DH breakpoint on the der(14) and a VH breakpoint on the der(11); and one case had a breakpoint in the JH region located >100 bases from the nearest RSS motif, suggesting a RAG-independent break at IGH. No der(11) breakpoint could be amplified in eight cases. In sixteen cases (50%), one or both CCND1 breakpoints were within 4 bases of a CpG dinucleotide, a feature characteristic of translocation breakpoints in many human B cell lymphomas. Three CpG-associated “microclusters” were identified, i.e. breakpoints in two different tumors located at or near the same CpG site. Breakpoints in the sixteen (50%) “non-CpG” cases showed a significant association with AID hotspot motifs at the CCND1 locus. In addition, the non-CpG breakpoints were more likely to: 1) be located telomeric to the MTC, 2) involve 3' JH and 5' DH gene segments, and 3) be associated with immunoglobulin lambda light chain restriction; features that suggest occurrence at a late stage of pre-B cell maturation. In contrast, the CpG-associated breakpoints were: 1) more likely to be centromeric to the MTC, 2) not biased in their JH or DH segment usage, and 3) associated with kappa light chain restriction; features suggesting occurrence in an earlier pre-B cell or pro-B cell. Our results implicate AID in chromosomal breakage at both CpG and non-CpG sites within the CCND1 locus and suggest that AID and RAG collude to generate the chromosomal breaks underlying the t(11;14). Our findings also suggest that IGH-CCND1 rearrangements can occur at different stages of pre-B cell maturation. This study provides novel insights into the mechanism and developmental timing of the t(11;14) in human MCL, features that are likely to be relevant to a broad range of human lymphomas.

Disclosures:
Greisman: Signature Genomics, LLC: Patents & Royalties. Yi:Signature Genomics, LLC: Patents & Royalties.
Factors Predicting Early Mortality in Patients with Newly Diagnosed Multiple Myeloma,
Authors: Rana Vishal , Srivastava Geetika , Hayman Suzanne R , Buadi Francis K , Gertz Morie A , Lacy Martha Q , Greipp Philip R. , Zeldenrust Steven R , Dispenzieri Angela , Kyle Robert A , Lust John A , Short Kristen Detweiler , Dingli David , Russell Stephen J. , Rajkumar S. Vincent , Kumar Shaji 
Published: October 2019

Abstract
Abstract 3981

Background:
Patients with multiple myeloma (MM) can present with life threatening complications including lethal infections during the disease course. The mortality is high during the early period following diagnosis, mostly as a result of complications of the disease or treatment. It is not clear if we can identify patients at the highest risk of early death based on the presenting clinical and laboratory features.

Methods:
From among 1545 patients seen at our institution between Jan 1999 and Dec 2008, we identified 265 patients who died within 12 months of diagnosis. For each of these patients we identified two “controls” who had at least 12 months of follow up, were alive at the time of last follow up and were closest to the ‘case' patient in terms of time of diagnosis. We performed logistic regression using the clinical and laboratory features, to identify parameters that predict for 12-month mortality and to determine the best cutoffs.

Results:
This study included 265 patients as cases and 530 controls. The gender distribution was similar in the two groups. We examined the impact of age, performance status (PS), hemoglobin, platelets, serum creatinine, calcium, LDH, albumin, B2M, free light chain difference, plasma cell labeling index, ISS stage, risk category and exposure to novel agents upfront. Based on the results of univariate and then multivariate analysis – age> 72, ECOG PS>2, Calcium >11.3 and ISS stage 3 were found to be significant. We developed the risk score using 1 point for each adverse factor, Age> 72, PS > 2, ISS 3, and Calcium > 11.3. The odds ratio of patients dying in the first year was 2.7, 9.2 and 37 in the presence of one, two and three or more risk factors compared to none of the risk factors. We then looked at the impact of the initial therapy on outcome. 279 patients (35%) received one of the novel agents (thalidomide, lenalidomide or bortezomib) as initial therapy. The odds ratio for dying in the first year was 0.35 for patients receiving a novel agent compared to the rest. The impact of the novel agent was independent of the risk score, with the risk score predicting outcome in both groups.

Conclusions:
In newly diagnosed MM advanced age, poor performance status, ISS stage and high calcium were associated with early mortality. If eligible all patients should get the benefit of use of novel agent upfront. Identifying these patients at the time of diagnosis is important and should help develop better risk-adapted strategies.

Disclosures:
No relevant conflicts of interest to declare.
Flt3-Ligand Plays a Critical Role in Development and Function of CD8+/TCR− Facilitating Cells in Bone Marrow,
Authors: Huang Yiming , Miller Thomas , Xu Hong , Wen Yujie , Ildstad Suzanne T 
Published: October 2019

Abstract
Abstract 4003
Graft facilitating cells (FC) are a CD8+/TCR− bone marrow subpopulation that enhance engraftment of purified hematopoietic cells (HSC) in allogeneic mouse recipients without causing graft-versus-host disease. They also enhance engraftment of suboptimal numbers of syngeneic HSC. FC induce antigen-specific CD4+/CD25+/FoxP3+ regulatory T cells in vivo. The major subpopulation in FC is resembles plasmacytoid precursor dendritic cells (p-preDC) both phenotypically and functionally. Treatment of mice with Flt3 ligand (FL) results in a significant increase in FC in peripheral blood (PB) and FL-expanded-PB FC enhanced HSC engraftment. In this study, we evaluated the role of FL in FC development using FL-KO mice. We first compared FC from FL-KO B6 mice with FC from B6 mice to evaluate the FC total cellular composition. The number of FC was significantly decreased in FL-KO mice compared to wild type controls (P = 0.0003). The number of p-preDC FC was also significantly decreased (P = 0.0001), suggesting that FL is important in the development of p-preDC FC. Next, we tested whether FL-KO FC facilitate engraftment of HSC in allogeneic recipients. FC were sorted from FL-KO B6 mice and HSC (C-Kit+/Sca-1+/Lin−) were sorted from B6 mice. 10,000 B6 HSC plus 30,000 FL-KO FC were transplanted into NOD recipients conditioned with 950 cGy of total body irradiation. Controls received 10,000 B6 HSC with or without 30,000 B6 FC. Only 36% (5 of 14) NOD recipients of B6 HSC alone engrafted and two mice survived up to 160 days (Figure). Sixty-three percent (5 of 8) of recipients transplanted with B6 HSC + FL-KO B6 FC engrafted and only one mouse survived up to 160 days. Seventy-five percent (9 of 12) recipients of B6 HSC + B6 FC engrafted and seven of the mice survived more than 160 days. The level of donor chimerism in recipients of B6 HSC + B6 FC (57% ± 10%) was significantly higher than recipients of B6 HSC + FL-KO B6 FC (14% ± 3%; P = 0.003) or B6 HSC alone (22% ± 6%; P = 0.005). These data demonstrate that FL-KO FC fail to facilitate durable allogeneic HSC engraftment, suggesting that flt3-ligand plays a critical role in development of functional FC.

Disclosures:
Ildstad: Regenerex, LLC: Equity Ownership.
Donor B Cells in Transplants Augment Clonal Expansion and Persistence of Pathogenic Donor CD4+ T Cells in Autoimmune-Like Chronic Graft-Versus-Host Disease,
Authors: Young James Sundblom , Wu Tao , Chen Yuhong , Zhao Dongchang , Johnston Heather F , Li Xiaofan , Forman Stephen J. , Zeng Defu 
Published: October 2019

Abstract
Abstract 4021
Chronic graft-versus-host disease (cGVHD) manifests with autoimmune symptoms (i.e. increased serum levels of autoantibodies, donor T cell infiltration in skin and salivary gland tissues, and collagen deposition in skin tissues). Donor B cells have been indicated to play an important role in the pathogenesis of cGVHD in mouse models as well as in patients, but the mechanisms remain unclear. In the current studies, using a cGVHD mouse model of DBA/2 donor to MHC-matched BALB/c host, we have observed that donor B cells are activated by donor CD4+ T cells in transplants to upregulate MHC II and co-stimulatory molecules and produce IgG autoantibodies; in turn, donor B cells mediated clonal expansion of autoreactive donor-type CD4+ T cells, as judged by TCR spectratyping and in vitro T cell proliferation in response to donor- and host-type APCs. Kinetic studies showed that the presence of donor B cells in transplants was associated with persistence of GVHD target tissue damage (i.e. sclerodermatous skin) and persistence of donor CD4+ T infiltration in the tissues in which there is an expansion of Th1 and Th2 but not Th17. The presence of donor B cells in transplants also markedly augmented tissue damage in prototypical cGVHD targets such as the salivary gland. Sorted donor CD4+ T cells from primary recipients given donor B cell-containing transplants but not from the primary recipients given B cell-depleted transplants caused cGVHD-like tissue damage in the skin and salivary gland of adoptive recipients. These results indicate that donor B cells in bone marrow transplants play an important role in the generation and expansion of pathogenic CD4+ T cells that mediate chronic GVHD tissue damage.

Disclosures:
No relevant conflicts of interest to declare.
A Single Nucleotide Polymorphism in the NLRP3 Gene Is Associated with Acute Graft-Versus-Host Disease After HLA-Matched Unrelated Bone Marrow Transplantation,
Authors: Espinoza Luis J. , Takami Akiyoshi , Nakata Katsuya , Onizuka Makoto , Kawase Takakazu , Morishima Yasuo , Fukuda Takahiro , Kodera Yoshihisa , Nakao Shinji 
Published: October 2019

Abstract
Abstract 4073
NOD-like receptor family, pyrin domain containing 3 (NLRP3) is an innate immune receptor that exerts functions in the regulation of inflammation and apoptosis. Recent studies have shown that the single nucleotide polymorphism (SNP) rs10754558 (C>G) at the 3' untranslated region of NLRP3 gene is functional and is associated with various immunological diseases. Allele G is linked with a higher activity of NLRP3 than allele A, and plays important roles in increased susceptibility to allergic reactions and in protection of HIV infection. This study retrospectively examined the impact of the NLRP3 genotype of a total 659 recipients with hematologic malignancies and their unrelated donors on the clinical outcomes in unrelated HLA 12/12 matched bone marrow transplantation (BMT) through the Japan Donor Marrow Program. The genotype frequencies of G/G, G/C and C/C were 19%, 50% and 31% in recipients and 18%, 49% and 32% in donors (P =0.79). The donor G/G or G/C genotype was associated with a significantly higher incidence of grades III to IV acute graft-versus-host disease (GVHD; 15% vs. 7%, P =0.004; Fig 1B) and a trend toward a higher incidence of grades II to IV acute GVHD (34% vs. 27%, P =0.06; Fig 1A), while no significant differences between the G/G genotype and G/C genotype were seen. The donor G/G or G/C genotype remained statistically significant in the multivariate analysis for the development of grades III to IV acute GVHD (hazard ratio [HR], 2.18; 95% confidence interval [CI], 1.22 to 3.90; P =0.009) as well as a trend toward an association with grades II-IV acute GVHD (HR, 1.31; 95% CI, 0.96 to 1.80; P =0.09). The recipient NLRP3 genotype did not significantly influence the transplant outcomes. These results suggest an association of the donor NLRP3 genotype with the development of acute GVHD after unrelated BMT. Genotyping for the NLRP3 rs10754558 could be useful in donor selection and risk-adapted management of transplanted patients, and may furthermore offer some novel therapeutic insights into the mechanisms of acute GVHD.

Disclosures:
No relevant conflicts of interest to declare.
Graft Source and HLA-Matching Degree-Based Analyses of Long-Term Outcomes of Unrelated Donor Transplants in Adult High-Risk Acute Lymphoblastic Leukemia: Similar Outcomes Between Bone Marrow and Peripheral Blood Progenitor Cells Transplants,
Authors: Lee Seok , Yahng Seung-Ah , Lee Sung-Eun , Cho Byung-Sik , Eom Ki-Seong , Kim Yoo-Jin , Chung Nak-Gyun , Kim Hee-Je , Min Chang-Ki , Kim Dong-Wook , Lee Jong-Wook , Min Woo-Sung , Park Chong-Won 
Published: October 2019

Abstract
Abstract 4167

Background:
Adults with high-risk acute lymphoblastic leukemia (ALL) have a poor outcome with standard chemotherapy and usually undergo unrelated donor stem cell transplantation (URD-SCT) if a matched sibling donor is not available. However, long-term results of URD-SCT, especially based on HLA-matching degree and graft source, are scarce in adult high-risk ALL. To assess the effect of HLA-matching degree and graft source, we analyzed long-term outcomes of 109 consecutive URD transplants with adult high-risk ALL (2000–2008).

Method:
Using allele-level typing, graft sources were classified as 8/8-matched bone marrow (BM; n=31), 8/8-matched peripheral blood progenitor cells (PBPC; n=19), 7/8-matched BM (n=35), and 7/8-matched PBPC (n=24). Patients received total body irradiation (≥12 Gy)-based full-intensity (n=95) or reduced-intensity (fludarabine plus melphalan; n=14) conditioning regimens. All patients received the same graft-versus-host disease prophylaxis consisting of tacrolimus plus methotrexate. Antithymocyte globulin was administered to all 7/8-matched transplants.

Result:
After a median follow-up of 57 months, the 5-year cumulative incidence of relapse was 19% for 8/8-matched BM, 16% for 8/8-matched PBPC, 37% for 7/8-matched BM, and 48% for 7/8-matched PBPC (P=0.013). Conversely, no significant difference in the 5-year cumulative incidence of non-relapse mortality was observed between each group of patients. Consequently, disease-free survival (DFS) at 5 years was inferior using 7/8-matched BM (46%) or 7/8-matched PBPC (42%), compared with 8/8-matched grafts (65% for BM and 58% for PBPC) (P=0.044). However, when considering pre-transplant disease status and conditioning intensity, no influence of HLA-matching degree and graft source on outcomes was found in transplants receiving full-intensity conditioning in first complete remission (CR1). Notably, outcomes were similar between BM and PBPC transplants in each group of patients showing the same HLA-matching degree. Regardless of HLA-matching degree and graft source, pre-transplant disease status (CR1 versus >CR1) was an independent predictive factor affecting relapse (RR 3.09, P=0.005) and DFS (RR 2.69, P=0.003). The absence of chronic graft-versus-host disease was also associated with higher relapse (RR 5.60, P<0.001) and poorer DFS (RR 2.49, P=0.005).

Conclusion:
Our long-term data suggest that outcomes are similar for transplantation using BM or PBPC in the setting of 8/8-matched or 7/8-matched URD-SCT in adult high-risk ALL.

Disclosures:
No relevant conflicts of interest to declare.
The Profile of Endothelial Function in Children with ALL Is Associated with the Risk Stratification Determining the Outcome – a Pilot Study
Authors: Niedzielska Ewa , Doroszko Adrian , Chybicka Alicja , Szuba Andrzej 
Published: October 2019

Abstract
Abstract 4230

Background:
Endothelial dysfunction (ED) is characterized by impaired balance between pro- and anti-aggregatory, pro- and anti-inflammatory factors as well as vasodilative and vasoconstrictive action of numerous metabolic and signaling pathways. ED is an important factor worsening the outcome in severe diseases. The aim of this study was to assess if the profile of endothelial function during the treatment of ALL might be associated with the risk stratification and with the outcome.

Material and Methods:
N=18 children at age of 4–18 years with ALL, treated with the ALLIC- BFM 2002 protocol were investigated. Plasma levels of the NO pathway metabolites (L-Arginine, ADMA – an endogenous competive eNOS inhibitor), markers of endothelial inflammatory and aggregatory function (VCAM-1, ICAM-1, E-selectin, P-selectin and PAI-1), lipid peroxidation (MDA – malonyldialdehyde) were analyzed at baseline, then during the 33rd and 78th day of treatment. Results were compared between three subgroups: standard risk, intermediate risk and high risk.

Results:
Subjects in the high risk groups were characterized by increased baseline lipid peroxidation, as assessed by the MDA levels in comparison to those in the standard risk group (8.56±2.14U/ml vs. 3.57±0.81U/ml, respectively, p<0.05). In the high risk group low E-selectin levels at baseline (32.1±6.1ng/ml vs. 101.3±11.8ng/ml in the standard risk group, respectively, p<0.05), as well as high NO production at the beginning of the M protocol, assessed by the L-Arg/ADMA ratio (88.6±11.6ng/ml vs. 41.7±6.4ng/ml, respectively, p<0.05) were observed. Moreover, increase in the PAI-1 level during the therapy was associated with smaller risk for poor outcome.
Conclusions: Increased lipid peroxidation, low E-selectin at baseline, as well as increased NO bioavailability, decreased PAI-1 levels at the beginning of the M protocol are common feature in children classified to the high risk group. Low NO bioavailability at baseline and high at the beginning of the M protocol as well as decreased anti-inflammatory and antiaggregatory function of endothelium at the beginning of the M protocol are associated with higher risk for poor prognosis.

Disclosures:
No relevant conflicts of interest to declare.