bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reciprocal Interaction Between Osteoclasts and T Cells: Osteoclasts Inhibit T Cell Proliferation by IDO Produced in Response to T Cell-Derived IFN-γ and CD40 Ligand
Authors: Li Haiyan , Lu Yong , Hong Sungyoul , Qian Jianfei , Liu Zhiqiang , Zheng Yuhuan , Lan Yongsheng , He Jin , Yang Jing , Yi Qing 
Published: October 2019

Abstract
Abstract 694
Osteoclasts (OCs), the responsible cells for bone resorption, are derived from monocytic precursor cells, with the stimulation of macrophage colony-stimulating factor (M-CSF) and the receptor activator of nuclear factor κb ligand (RANKL). The formation and activity of OCs can be either promoted by activated T cell derived RANKL, IL-17, or suppressed by T cell derived IFN-γ, IL-10, and IL-4. On the other hand, OCs express MHC, and costimulatory molecules, secrete IL-10, TGF-β, TNF-α and IL-6 and can act as antigen presenting cells to activate T cells, which indicates that OCs can be considered as immune cells. However, the immune function of OCs is largely unknown, and whether activated T cells can regulate the immune function of OCs is also unclear. In this study, we investigated the effect of OCs on T cell responses, and the cross regulation between activated T cells and immune regulatory OCs. Results showed that autologous OCs could inhibit the proliferation of CD4+ T cells activated by allogeneic antigen, tetanus toxin, staphylococcal enterotoxin B, and anti-CD3/CD28 antibodies. The inhibitory rate range varied from 63% to 88%. To identify the mechanism of OC-mediated T cell suppression, we blocked or inhibited TGF-β, IL-10, (prostaglandin E2) PGE-2, and indoleamine 2,3-dioxygenase (IDO) with neutralizing antibodies or specific inhibitors during the coculture. Results showed that only 1-methyl-DL-tryptophan (1-MT, an IDO inhibitor) could rescue the T cell proliferation, which suggested that OCs mediated the T cell suppression through IDO. To confirm this result, we knocked down IDO expression in OCs with siRNA and found that T cell proliferation was restored completely. As normal OCs didn't express IDO, next we investigated which molecules induced IDO expression in OCs, when cocultured with activated T cells. Results showed that blocking IFN-γ and CD40 ligand (CD40L) could inhibit IDO expression in OCs and rescue the T cell proliferation, and recombinant IFN-γ and soluble CD40L could induce IDO expression in OCs, synergistically. In conclusion, our study identified that OCs can function as immune regulatory cells to suppress T cell proliferation through IDO, which is induced by activated T cell derived IFN-γ and CD40L. This study provides new insight into the reciprocal interaction between OCs and T cells and may be helpful to develop novel therapeutic strategies for diseases involved in both bone and immune systems, such as bone-invasive tumors and autoimmune arthritis.

Disclosures:
No relevant conflicts of interest to declare.
Molecular Structure and Biological Activity of NPP-4, An Endothelial Cell Surface Pyrophosphatase/ Phosphodiesterase That Stimulates Platelet Aggregation and Secretion Via Liberation of ADP Upon Hydrolysis of Diadenosine Triphosphate
Authors: Ornstein Deborah L. , Albright Ronald , Chang William C. , Robert Donna , Cao Wenxiang , De La Cruz Enrique , Braddock Demetrios 
Published: October 2019

Abstract
Abstract 701
Diadenosine triphosphate (Ap3A) is a component of platelet dense granules, and is released into the extracellular space during the second wave of platelet aggregation following platelet activation by ADP and other agonists. Ap3A has long been thought to stimulate platelet aggregation after release into the extracellular space by providing a prolonged source of ADP via hydrolysis by a slow extracellular enzyme present in human plasma. Here, we identify NPP-4, a member of the nucleotide pyrophosphatase/phosphodiesterase enzyme family present on endothelial cell surfaces, as a potent hydrolase of Ap3A capable of stimulating platelet aggregation and secretion at nanomolar concentrations. We performed lumiaggregometry with citrated platelet-rich plasma in the presence of Ap3A with or without increasing nanomolar concentrations of NPP-4. In these experiments we determined that Ap3A alone in concentrations up to 80 uM initiated a primary wave of platelet aggregation that was followed by rapid disaggregation. In the presence of nanomolar concentrations of NPP-4, however, the primary and secondary waves of platelet aggregation and dense granule release are strongly induced in an enzyme concentration-dependent fashion. In contrast, mutant NPP-4, catalytically inactivated by an active site threonine to alanine mutation, had no effect on platelet aggregation and dense granule release under identical conditions. In order to clarify the structural basis of the enzymatic mechanism, we determined the high-resolution structure of NPP4 in the presence and absence of the enzymatic product, AMP. In aggregate, our studies define the biological, enzymatic, and molecular basis for NPP-4 and Ap3A activity in platelet aggregation and secretion in vitro and suggest that NPP-4 may play a role in hemostasis in vivo by augmenting platelet aggregation and release of granule contents at the site of vascular injury. With these studies we have thus established the molecular foundation for the rational development of a new class of therapeutics capable of modulating vascular thrombosis.

Disclosures:
No relevant conflicts of interest to declare.
ENDOTHELIAL GAS6 Contributes to Thrombogenesis and Promotes TISSUE FACTOR Upregulation DURING Vessel Injury
Authors: Robins Richard , Lemarie Catherine A , Wu Jianqiu , Blostein Mark 
Published: October 2019

Abstract
Abstract 702
Gas6 is a vitamin K-dependent, secreted protein that amplifies platelet aggregation and secretion in response to platelet agonists. Gas6−/− mice are protected from experimentally induced lethal venous and arterial thromboembolism. This protection has been attributed to defective aggregation in platelets from gas6−/− mice. However, this platelet phenotype was only observed when platelets were challenged by only one agonist, ADP, and only at a concentrations of 5.0μM. This subtle platelet abnormality resulting in a rather dramatic clinical phenotype raise the possibility that gas6 from a source other than platelets contributes to thrombus formation. We hypothesize that gas6 derived from the endothelium plays a role in venous thrombus formation. Gas6−/− mice are protected against venous thrombosis induced by 0.37 M FeCl3 in the inferior vena cava (IVC). Bone marrow transplantation experiments generating mice with selective ablations of gas6 from either the hematopoietic or non-hematopoietic compartments demonstrate an approximately equal contribution by gas6 from both compartments to thrombus formation. Platelet depletion in wild type or gas6−/− mice followed by reconstitution with platelets from either WT or gas6−/− mice confirm that gas6 from compartments other than the platelet contribute to thrombosis development. Furthermore, gas6−/− mice are hyporesponsive to FeCl3 mediated tissue factor induction in venous endothelium, as observed by immunofluorescence staining and later validated by a functional assay. In addition, in vitro, gas6−/− endothelial cells are hyporesponsive to thrombin mediated tissue factor mRNA induction. Taken together, these results suggest that non-hematopoietic gas6, possibly from the endothelium, contributes to thrombus formation in vivo and can be explained by the ability of gas6 to promote endothelial tissue factor induction. These findings support the notion that endothelial gas6 may play a pathophysiologic role in venous thromboembolism.

Disclosures:
No relevant conflicts of interest to declare.
Polymorphisms in Antitrombin (SERPINC1) and Tissue Factor Pathway Inhibitor (TFPI) Genes Are Associated with Recurrent Pregnancy Loss
Authors: Guerra-Shinohara Elvira Maria , Bertinato Juliano Felix , da Silva Giusti Kelma Cordeiro , Seino Fernanda Midori , Bueno Carolina Tosin , de Carvalho Mario Henrique Burlacchini , Amorim Filho Antônio Gomes , Zugaib Marcelo , Chiattone Carlos S 
Published: October 2019

Abstract
Abstract 711

Background:
Recurrent pregnancy loss (RPL) is a multifactorial condition. The effects of antithrombin (SERPINC1), protein C (PROC), thrombomodulin (THBD) and tissue factor pathway inhibitor (TFPI) gene polymorphisms in the risk of having RPL are unknown.

Aims:
To determine the effects of SERPINC1, PROC, THBD and TFPI gene polymorphisms in the risk of having RPL.

Methods:
One hundred and fifteen non-pregnant women with three consecutive losses prior to 20 weeks of pregnancy without carrying a fetus to viability (primary RPL) and 253 healthy fertile non-pregnant women who had at least two children and no known pregnancy losses were studied. The PROC (rs1799809 and rs1799808), SERPINC1 (rs2227589), THBD (rs1042579) and TFPI (rs10931292 and rs8176592) gene polymorphisms were detected respectively by Real Time PCR.

Results:
No difference was observed among the genotypes frequencies for PROC 2418A>G, PROC 2405C>T, THBD 1418C>T and TFPI T-33C polymorphisms in two groups (Table 1, P>0.05). However, the carriers of 140T allele (CT + TT genotypes) for SERPINC1 C+140T polymorphism had 1.73 (95% CI: 1.00 – 2.99) times risk of having RPL. Furthermore, the carriers of TC + CC genotypes for TFPI T-287C polymorphism had a protection effect of having RPL (OR: 0.48, 95% CI 0.27– 0.86).

Conclusions:
The variant of SERPINC1 C+140T polymorphism is associated with higher risk of having RPL while the variant of TFPI T-287C polymorphism is associated with a protection effect.

Disclosures:
No relevant conflicts of interest to declare.
Hematopoietic Stem Cell Transplantation in Thalassemia Major. Report from the EBMT Hemoglobinopathy Registry
Authors: Baronciani Donatella , Pilo Federica , Lyon-Caen Sarah , Poetschger Ulrike , Dini Giorgio , Peters Christina 
Published: October 2019

Abstract
Abstract 905

Background.
Hemopoietic allogeneic stem cell transplantation (HSCT) still remains the only available curative option for β-thalassaemia major. At today more than 3000 transplants have been performed worldwide and registered. We analyze transplant activity and outcome after 20 years of the European Hemoglobinopathy Bone Marrow Transplant (EBMT) Registry.

Methods.
Data have been analyzed from promise MED-A form. Survival data have been reported with the method of Kaplan-Meier in patients with complete survival data.

Results.
One hundred and 34 centres from 28 different countries reported their data to the registry. Three thousands and 821 (3821) consecutive first HSCT for patients affected by a hemoglobinopathy have been registered. There were only 364 (10.5%) patients aged 18 years or older. Further analyses were restricted to patients with thalassemia major and to transplants performed after January 1st, 2000. In this latter period 1493 transplants have been performed (median age 7.2 years, range 0.3–45.1) with 133 (9.8%) patients aged 18 years or older.
During the last decade 70% of the transplants have been performed in Europe and 30% in Asia and Africa with a trend to an increase activity in these countries compared to previous decades.
Of the 1493 transplants performed after January 2000, 1061 (71%) have been performed from an HLA identical sibling donors, 129 (8.6%) from a matched other relative, 57 (3.8%) from a mismatched relative, 210 (14%) from an unrelated donor and in 36 (2.4%) cases donor information were missing. Source of stem cells was bone marrow in 1011 patients (67.7%), peripheral blood in 303 patients (20.3%), cord blood in 60 patients (4%), mixed in 82 patients (5.5%). Source of stem cell was missing in 37 (2.5%).
In matched sibling donor transplant recipients overall survival (OS) and thalassemia free survival (TFS) plotted at 91 ± 0.01% and 83 ± 0.01%, respectively. Significant differences have been reported in OS and TFS when related to different age groups as reported in Table 1 (P < 0.001).

Conclusion.
This analysis confirms allogeneic transplantation is a worldwide diffuse high success curative procedure for β-thalassaemia major. Bone marrow still remains the principal source of stem cells. The large majority of transplants have been performed from a matched sibling donor with a marginal role of other donors. In addition these data demonstrate the trend to not transplant adult patients. In the univariate analyses 14 years old appears as threshold age for best transplant strategy.

Disclosures:
No relevant conflicts of interest to declare.
Primary T Cell Immunodeficiencies and Autoimmunity
Authors: Fischer Alain 
Published: October 2019

Abstract
Abstract SCI-21
There are a variety of primary T cell immunodeficiencies that can impair T cell differentiation or T cell activation. The latter include CD38δ deficiency, ZAP70 deficiency, Ca++ influx deficiency (ORAI1 and Stim1 deficiencies), and ITK deficiency as well. A new T cell activation deficiency as observed in a patient with defective T cell receptor triggered T cell activation and low CD4 T cell counts will be reported. A remarkable and quasi constant feature shared by all those T cell activation defects is the occurrence of autoimmune diseases, mostly related to autoantibodies, and inflammation such as colitis or panniculitis. Several mechanisms can account for these findings that include defective regulatory T cell development or function, defective negative selection impaired intrinsic feedback mechanism as well as non TCR-mediated T cell activation ultimately leading to proinflammatory cytokines release and autoantibody production by B cells. Another new form of primary T cell immunodeficiency with autosomal recessive inheritance observed in four patients from two families will be described. It is characterized by defective survival of naïve T cells. There again, autoimmunity appeared to be a significant component of the phenotype. Collectively, these results indicate that further insight into the role of key molecules in T cell activation/survival is provided by the analysis of new primary immunodeficiency phenotypes. In addition, the occurrence of autoimmunity in these settings stresses on one hand the role of T cells in the control of reactivity to self and, on the other hand, should be considered in the therapeutic strategy of these conditions.

Disclosures:
No relevant conflicts of interest to declare.
Functions of Platelet Microparticles in Inflammatory Arthritis
Authors: Cloutier Nathalie , Farndale Richard W. , Brisson Alain , Boilard Eric 
Published: October 2019

Abstract
Abstract SCI-35
Besides their pivotal role in thrombosis and wound repair, platelets can participate in inflammatory responses via a broad arsenal that includes CD40L and CD40, cyclooxygenase-1 mediated prostaglandins, leukotrienes, IL-1, RANTES, serotonin, platelet factor 4, matrix metalloproteinases -2 and -9, P-selectin, adenosine diphosphate, and reactive oxygen species. Rheumatoid arthritis (RA) is amongst the most common autoimmune chronic inflammation that affects the joints. Interestingly, we found copious amounts of submicron particles that harbor platelet integrins in the synovial fluid of patients suffering from RA, pointing to evidence of platelet activation in this inflammatory autoimmune disease. Importantly, we identified the collagen receptor glycoprotein VI as a key trigger for platelet microparticle generation in arthritis pathophysiology. In addition to the transcellular collaboration between platelets and fibroblast-like synoviocytes in generation of pro-inflammatory prostacyclin (1), we found that platelets contribute to synovitis by production of IL-1-rich platelet microparticles (2). These recent advances in understanding of the platelet activities in inflammation notwithstanding, the mechanisms by which platelet microparticles invade the diseased joint in RA remain obscure. Using synovial biopsies from patients suffering from RA in addition to in vivo imaging strategies in a murine model of arthritis, our current work aspires to dissect the means of transportation of platelet microparticles during RA. Given their pro-inflammatory properties, to understand the process by which microparticles invade the synovial joint is of great clinical interest.

Disclosures:
No relevant conflicts of interest to declare.
The Interplay of Inflammation and Cancer
Authors: Dranoff Glenn 
Published: October 2019

Abstract
Abstract SCI-4
Efficacious cancer immunotherapies will likely require combinations of strategies that enhance tumor antigen presentation and antagonize negative immune regulatory circuits. We demonstrated that vaccination with irradiated, autologous melanoma cells engineered to secrete granulocyte-macrophage colony-stimulating factor (GM-CSF) followed by antibody blockade of CTLA-4 accomplishes clinically significant tumor destruction with minimal toxicity in some advanced cancer patients. The detailed analysis of patients achieving sustained clinical benefits from these therapies illustrated the importance of a coordinated cellular and humoral anti-tumor immune response. Indeed, the extent of tumor necrosis in posttreatment biopsies was linearly related to the natural logarithm of the ratio of infiltrating CD8+ effector T cells to FoxP3+ Tregs. Moreover, therapy induced a potent antibody response to several key tumor cell surface and secreted proteins; these antibodies manifest functional activity in vitro, antagonizing tumor cell survival, invasive potential, and angiogenesis. Through an analysis of cytokine deficient mice, we delineated a critical role for GM-CSF in Treg homeostasis. GM-CSF is required for the expression of the phosphatidylserine-binding protein MFG-E8 in antigen-presenting cells, whereas the uptake of apoptotic cells by phagocyte-derived MFG-E8 maintains peripheral Treg activity. While blockade of MFG-E8 can enhance therapeutic immunity in the context of cancer vaccines, loss of Treg homeostasis with MFG-E8 deficiency can lead to chronic inflammation. Mice deficient in GM-CSF and IFN-g develop at high frequency germinal center derived lymphomas and non-small cell lung carcinomas. The pathogenesis of these tumors reflects a combination of tumor-promoting inflammation and a loss of protective tumor immunity. Taken together, these findings highlight dual roles for immunity in cancer pathogenesis and therapy.

Disclosures:
No relevant conflicts of interest to declare.
Cost Effectiveness of Rivaroxaban Versus Warfarin for the Prevention of Recurrent Venous Thromboembolism.
Authors: Seaman Craig D. , Ragni Margaret V. , Smith Kenneth J. 
Published: October 2019

Abstract
Abstract 3177

Background:
Rivaroxaban is an oral anticoagulant administered once daily that works by direct inhibition of factor Xa. It has been found to be noninferior to warfarin in the prevention of recurrent venous thromboembolism (VTE). Whether rivaroxaban is cost effective in the prevention of recurrent VTE, however, is not known.

Methods:
To assess the cost effectiveness of rivaroxaban compared with warfarin in the prevention of recurrent VTE, we built a Markov state transition model over a 10-year time horizon. The base case analysis consisted of a hypothetical cohort of 60-year-old patients who were diagnosed with their first VTE and received secondary prophylaxis with either rivaroxaban or warfarin for 6 months. Cost estimates were derived from the Healthcare and Utilization Project (HCUP) and other sources. Probabilities for VTE recurrence and mortality and for major and minor bleeding were based on the EINSTEIN PE trial (NEJM 2012; 366: 1287–97). Outcomes included costs in 2011 United States dollars, quality adjusted life years (QALYs), and incremental cost effectiveness ratios (ICERs) over 10 years from a societal perspective.

Results:
Base case results are shown in the Table, showing total medication and other medical costs associated with each strategy. Compared with warfarin, the rivaroxaban strategy cost less ($4057 vs $7004) and was more effective (9.30 QALYs vs 9.16 QALYs). Thus, warfarin was dominated by rivaroxaban. In sensitivity analyses, results were most sensitive to changes in the probability of major bleeding with rivaroxaban. As shown in the Figure, when major bleeding with rivaroxaban (base case 1.1%) was less than 4.5%, the ICRE was within the $100,000 per QALY gained acceptability threshold range. Results favoring rivaroxaban were robust to individual variation of other parameter values.

Conclusion:
Prophylactic anticoagulation with rivaroxaban appears to be a cost effective, and perhaps cost saving, alternative to warfarin for the prevention of recurrent VTE.

Disclosures:
Off Label Use: Rivaroxaban - Prevention of recurrent venous thromboembolism.
Missense Mutations in the ABCB6 Transporter Cause Dominant Familial Pseudohyperkalemia
Authors: Andolfo Immacolata , Alper Seth , Delaunay Jean , Auriemma Carla , Russo Roberta , Esposito Maria Rosaria , Sharma Alok K. , Shmukler Boris E , Vandorpe David H , Brugnara Carlo , De Franceschi Lucia , Iolascon Achille 
Published: October 2019

Abstract
Abstract 3184
Isolated Familial Pseudohyperkalemia (FP) is a dominant red cell trait characterized by cold-induced slow ‘passive leak’ of red cell K+ into plasma, first described in a large Scottish family from Edinburgh (Stewart GW, et al., 1979). Although in freshly obtained blood samples plasma [K+] was normal, it was increased when measured in blood stored at or below room temperature. This trait was unaccompanied by clinical symptoms or signs except for mild abnormalities of red cell shape. FP Lille was later described in a large Flemish kindred with morphologically normal red cells (Dagher G, et al., 1989; Vantyghem MC, et al., 1991). In this family, red cell K+ efflux measured in the presence of ouabain and bumetanide was normal at 37°C, but greatly increased at 22°C and 9°C. FP Lille mapped to 2q35-q36 (Carella M, et al., 2004), whereas FP Edinburgh mapped to 16q23-qter (Iolascon A, et al., 1999). Subsequently, asymptomatic cases FP Chiswick and FP Falkirk with remarkable increased MCV were reported (Haines PG, et al., 2001).
Functional gene mapping and sequencing analysis of the candidate genes within the 2q35-q36 critical interval in three multigenerational FP families with 20 affected individuals identified two novel heterozygous missense mutations in the ABCB6 gene that cosegregated with disease phenotype. The two genomic substitutions altered two adjacent nucleotides within codon 375 of ABCB6, a porphyrin transporter that in erythrocyte membranes bears the Langereis blood group antigen system (Krishnamurthy PC, et al., 2006; Helias V, et al., 2012). Structural modeling predicts subtle changes in protein structure associated with either mutation.
ABCB6 mRNA and protein levels increased during erythroid differentiation of CD34+ erythroid precursors (at 7 and 14 days of EPO induced differentiation), and of HEL and K562 erythroleukemia cells. However, the ABCB6 R375Q mutation altered neither levels of ABCB6 mRNA or protein, nor protein localization in mature erythrocytes or erythroid precursor cells. These data strongly suggest that missense mutations in residue 375 of the ABCB6 polypeptide either mediate the cold-induced K+ leak of chromosome 2-linked FP, or activate an independent, cold-induced cation permeability pathway of the red cell.

Disclosures:
No relevant conflicts of interest to declare.