bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inducible Costimulator Gene Transduced Bone Marrow Derived Mesenchymal Stem Cells Attenuate the Severity of Acute Graft-Versus-Host Disease in a Mouse Haploidentical Model.
Authors: Yang Dan , Wang Jian-Min , Wang Li-ping , Zhou Hong 
Published: October 2019

Abstract
Abstract 2996
It is reported that both block of costimulator (ICOS) or its ligand signal pathway and transfusion of mesenchymal stem cells (MSCs) can reduce the severity of acute graft-versus-host disease (GvHD). Using a MHC-haploidentical murine model of acute GvHD, we investigated the effects of MSC-ICOS-EGFP, bone marrow derived MSCs transduced with ICOS-gene using an adenoviral vector, on acute GvHD. Lethally irradiated CB6F1 mice were transplanted with bone marrow cells and spleen cells from C57BL/6 mice, and injected with MSC-ICOS-EGFP, MSCs, ICOS-Ig fusion protein or the diluent (control), respectively. Survival in recipients of MSC-ICOS-EGFP was significantly higher than that in GVHD group (74.29±7.39% vs 0, P=0.000, n=35), and also higher than in MSCs, ICOS-Ig, or MSCs+ICOS-Ig groups (74.29±7.39% vs 42.86±8.36% or 48.57±8.45% or 50.43±8.45%, P=0.0039 or 0.0323 or 0.0418, n=35). The lower mortality in recipients of MSC-ICOS-EGFP was related to lower incidence of acute GvHD. MSC-ICOS-EGFP can reduce the number of CD4+T cells in the early stage of GvHD due to the increased apoptosis, and it can produce CD4+CD25+Treg cells meanwhile. The effect on GvHD in recipient of MSC-ICOS-EGFP was also associated with higher serum levels of IL-4, IL-10 and lower levels of IFN-γ, IL-2, IL-12, IL-17A, as well as inducing expression of GATA-3, STAT6 transcription factors while inhibiting expression of T-bet, STAT4, ROR-rt in spleen. In vitro, the CD4+T cells of donor were sharply inhibited by MSC-ICOS-EGFP and the B7h blockade. In MLRs we can also detect lower levels of IFN-γ, IL-2and higher levels of IL-4, IL-10. These data indicate that MSC-ICOS-EGFP is a more prospective strategy for acute GvHD prevention, which had a synergism effect between MSCs and ICOS-Ig. The mechanisms of MSC-ICOS-EGFP on acute GvHD were closely associated with modulation of CD4+T cells, CD4+CD25+Tregs, and regulation of the Th1/Th2/Th17 balance in the early stage of GvHD.

Disclosures:
No relevant conflicts of interest to declare.
Role of Serum Lactate Dehydrogenase (LDH) As a Prognostic Marker for Autologous Hematopoietic Stem Cell Transplantation for Multiple Myeloma.
Authors: Patel Krina , Orlowski Robert Z. , Shah Nina , Bashir Qaiser , Parmar Simrit , Dinh Yvonne T , Rondon Gabriela , Giralt Sergio A , Champlin Richard E. , Qazilbash Muzaffar 
Published: October 2019

Abstract
Abstract 3115

Background:
The International Staging System (ISS), chromosomal abnormalities, and response to therapy are well recognized predictors of outcome in multiple myeloma (MM). However, the role of serum lactate dehydrogenase (LDH) as a prognostic marker for MM is not well established. Recently we showed that high LDH at diagnosis of MM is a predictor of shorter survival. Here we report the impact of the LDH level at the time of autologous hematopoietic stem cell transplantation (auto-HCT) on its outcome.

Methods:
We evaluated 1,658 patients with symptomatic myeloma who underwent auto-HCT from July 1988 to December 2010 at our institution. The primary objective was to determine the impact of high LDH (>1000 IU/L) level, obtained on the start day of the preparative regimen, on progression free survival (PFS) and overall survival (OS).

Results:
Patient characteristics according to LDH level at auto-HCT are summarized in Table 1. Patients in the 2 LDH groups (>1000 or ≤ 1000) were matched for age, gender, disease status, and response to prior therapy at the time of auto-HCT. Patients with LDH >1000 IU/L had a significantly higher beta-2 microglobulin (β2m) and bone marrow plasmacytosis at the time of auto-HCT. Median times to neutrophil (10 vs. 10 days: p=0.10) and platelet engraftment (11.3 vs.12.2 days: p=0.20) were not different in the 2 groups. Also, there was no significant difference in CR, VGPR, PR or overall response rates between the 2 groups. Median follow up was 35 months (1 to 244). Median OS in patients with LDH >1000 and ≤ 1000 were 49.2 and 68.0 months, respectively (p=0.03). Median PFS in patients with LDH >1000 and ≤ 1000 were 14.4 and 24.7 months, respectively (p=0.001). On univariate analyses, >10% plasma cells in bone marrow biopsy, relapsed disease, serum β2M ≥ 3.5 at auto-HCT, presence of any chromosomal abnormality, and < PR after auto-HCT were associated with significantly shorter PFS and OS.

Conclusions:
Having a serum LDH value of >1000 IU/L prior to auto-HCT is associated with shorter PFS and OS in patients with MM. These high risk patients may require aggressive post-transplant therapy, including consolidation, maintenance, tandem transplants or novel approaches like immunotherapy.

Disclosures:
Shah: Celgene: Membership on an entity's Board of Directors or advisory committees.
Risk Factor Analysis Of Non-Hodgkin Lymphoma-Associated Hemophagocytic Syndromes: A Multicenter Study
Authors: Sano Hirozumi , Kobayashi Ryoji , Tanaka Junji , Hashino Satoshi , Ota Shuichi , Torimoto Yoshihiro , Kakinoki Yasutaka , Yamamoto Satoshi , Kurosawa Mitsutoshi , Hatakeyama Naoki , Haseyama Yoshihito , Sakai Hajime , Sato Kazuya , Fukuhara Takashi 
Published: October 2019

Abstract
Hemophagocytic lymphohistiocytosis (HLH) is often associated with malignant diseases, mainly B-cell or T/NK-cell lymphoma. However, to date, few studies have examined lymphoma-associated hemophagocytic syndrome (LAHS). Our aim was to clarify the risk factors and prognostic factors of LAHS. A total of 1,181 patients with non-Hodgkin lymphoma were analyzed at 12 institutions in Hokkaido prefecture between April 2007 and December 2011 to assess the incidence, prognosis, and risk factors of LAHS. To evaluate the risk factors for developing LAHS, patient characteristics including age, gender, and histopathology were compared between patients with and without LAHS. The cumulative incidence rate of LAHS was 3.0% (35/1,181). The mortality rate of patients with LAHS was 69% (24/35), which was significantly higher than that of patients without LAHS (29%, P<0.001). The frequency of LAHS was higher in patients with T/NK-cell lymphoma than in patients with B-cell lymphoma (11.6 vs 1.8%, P<0.001). No significant differences were observed in age or gender between patients with and without LAHS. Patient characteristics including age, gender, histopathology, clinical symptoms, treatment for LAHS, EB virus serology, and laboratory data were subsequently compared between alive and dead patients to evaluate the prognostic factor of LAHS. The results obtained showed that the mortality rate was significantly higher in patients with T/NK-cell lymphoma than in patients with B-cell lymphoma (88 vs 53%, P=0.035). The frequency of liver dysfunction, including elevated total bilirubin (T.Bil) and liver enzymes [glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT)], was higher in fatal cases than in alive cases (T.Bil, median 1.35mg/dl, range 0.6-12.7mg/dl vs median 0.9mg/dl, range 0.5-6.1mg/dl, P=0.069; GOT, median 85.5IU/L, range 16-1,076IU/L vs median 40.0IU/L, range 10-651IU/L, P=0.076; GPT, median 62.5IU/L, range 11-910IU/L vs median 31.0IU/L, range 6-362IU/L, P=0.038). Moreover, the mortality rate of patients who did not respond to initial treatments including corticosteroids was higher than that of good responders (95 vs 54%, P=0.049). EB virus serology had no significant clinical impact on the prognosis of LAHS. In conclusion, patients with T/NK-cell lymphoma showed not only higher complication rates of LAHS than those of patients with B-cell lymphoma, but also higher mortality rates after developing LAHS. Further preclinical and clinical studies are required to understand the detailed pathogenesis of LAHS and improve the prognosis of patients developing LAHS.

Disclosures:
No relevant conflicts of interest to declare.
Adult T-Cell Leukemia/Lymphoma Cells Were Eliminated By T Cells With Anti-CD38 Chimeric Antigen Receptor Through CD38 Expression Induced By All-Trans Retinoic Acid
Authors: Yoshida Tetsumi , Mihara Keichiro , Kitanaka Akira , Shimoda Kazuya , Morishita Kazuhiro , Takihara Yoshihiro , Ichinohe Tatsuo 
Published: October 2019

Abstract
Patients with adult T-cell leukemia and lymphoma (ATLL) often succumb to death even though multi-anti-cancer drugs are used. Thus, it is essential for establishing a novel therapeutic strategy for ATLL. We have previously developed a chimeric antigen receptor against CD38 (anti-CD38-CAR) and showed powerful cytotoxicity of anti-CD38-CAR to B-cell lymphoma cells as well as to myeloma cells expressing CD38. Unfortunately, as CD38 is poorly expressed on the cell surface of ATLL cells, it is required to induce CD38 to apply our anti-CD38-CAR. Here, we investigated cytotoxicity of T cells transduced with anti-CD38-CAR against ATLL cell lines and cells obtained from ATLL patients through CD38 induction by all-trans retinoic acid (ATRA), which is clinically available for acute promyelocytic leukemia. We evaluated an effect of ATRA on cytotoxicity of T cells bearing anti-CD38-CAR against ATLL cells through flow cytometry. We firstly confirmed the expression of anti-CD38-CAR on human T cells retrovirally transduced (10-70%). Then, secondly, we prepared ATLL cell lines (MT-2, MT-4, S1T, Hut102, and Su9T: >95%, <5%, <5%, 15%, and <5% at CD38 expression, respectively). We co-incubated CD38-specific T cells with ATLL cell line cells for 3 days. MT-2 cells were entirely abrogated by T cells harboring anti-CD38-CAR. However, others were restrictedly succumbed to death after 3-day co-culture with T cells carrying anti-CD38-CAR. Next, we investigated whether ATRA could enhance CD38 expression on the cell surface of ATLL cell lines and exert a cytotoxicity of T cells with anti-CD38-CAR. Intriguingly, even 10nM of ATRA augmented CD38 expression in MT-4, S1T, and Hut102 cells (>80%), but not in Su9T cells. Co-culture experiments in the presence of ATRA showed that MT-4, S1T, and Hut102 but Su9T cells were efficiently eliminated by T cells bearing anti-CD38-CAR, leading to a positive correlation of cytotoxicity with CD38 expression level. We tested whether ATLL cells obtained from 3 patients were disrupted by T cells bearing anti-CD38-CAR. CD38 was expressed in the cells from patients at a variety of expression ratio (0-30%). Intriguingly, CD38 expression was significantly enhanced in ATLL cells from 2 of 3 individual patients with ATRA (>50%). And resultantly, T cells bearing anti-CD38-CAR exerted more powerful cytotoxicity against ATLL cells with CD38 enhanced by ATRA (cytotoxicity of T cells with anti-CD38-CAR in CD38-positive ATLL fraction: >90%). ATRA exerted enhancing effect on the cytotoxicity of T cells bearing anti-CD38-CAR against ATLL cells through the augmentation of CD38 expression. These results may provide us a rationale for novel clinical settings of T cells carrying anti-CD38-CAR on patients with ATLL using ATRA.

Disclosures:
No relevant conflicts of interest to declare.
Lymphoma Monocyte Crosstalk Via Hsp27 to Promote Immune Suppression and Chemotherapy Resistance
Authors: Zhang Zhe , Bulur Peggy A , Gustafson Michael , Gastineau Dennis A. , Dietz Allan B , Lin Yi 
Published: October 2019

Abstract
Background: Immune editing is a major mechanism used by tumors to promote its survival. We have reported previously the presence of a novel phenotype of immunosuppressive monocytes (CD14+HLA-DRlow/neg) in a number of cancers. Increased presence of these cells was associated with decreased treatment response and OS. We have demonstrated that certain tumor cells can convert normal CD14+HLA-DR+ monocytes to CD14+HLA-DRlow/neg phenotype in an IL-10 independent and a tumor specific way. These CD14+HLA-DRlow/neg monocytes, in turn, protect tumors from cytotoxic killing from chemotherapy. Here we report up-regulation of heat shock protein-27 (HSP27) as one mechanism mediating this effect.
Method: Monocytes from healthy donors were co-cultured with lymphoma cell lines (OCI-Ly3, Jeko-1, and Granta-519) with or without doxorubicin (DOX). Cultured cells were assessed for phenotype, viability and proliferation by flow cytometry. Lymphoma cells were isolated with anti-CD19 immunomagnetic beads and assayed by immunoblot for expressions of proteins regulating apoptosis. HSP27 levels in human plasma were measured by ELISA.
Results: DOX incubation induced apoptosis and decreased viability of all three cell lines; and co-culture with monocytes improved the lymphoma cell survival (for example, untreated Granta-519 had a 2.1±0.45 fold expansion, that was reduced to 0.39±0.12 when treated with DOX and 0.81±0.27 after co-culture with monocytes with DOX. p<0.05, n=11.) Co-culture with monocytes induced increased HSP27 expression in lymphoma cells. HSP27 levels were further increased in co-culture with monocytes and DOX, with corresponding decrease in cleaved Caspase-3 levels. As tumor cells can secrete HSP27, we found detectable levels of HSP27 in plasma of lymphoma patients. Increased HSP27 in plasma correlated with increased proportion of CD14+HLA-DRlow/neg monocytes in blood.
Conclusions: We have found that monocytes may promote lymphoma resistance to DOX killing by inducing increased HSP27. In turn, HSP27 from lymphoma patients may induce immune suppressive phenotype in monocytes. Together, this data demonstrates an active cross talk between monocytes and lymphoma resulting in multiple mechanisms of tumor resistance to chemo-immunotherapy.

Disclosures
No relevant conflicts of interest to declare.
A Novel Mechanism of GLI2 Mediated Regulation of IgM Secretion in Waldenström Macroglobulinemia
Authors: Jackson David A. , Smith Timothy D. , Amarsaikhan Nansalmaa , Vrabel Ann , Tolosa Ezequiel , Almada Luciana L. , Fernandez-Zapico Martin E. , Elsawa Sherine F. 
Published: October 2019

Abstract
Immunoglobulin (Ig) secretion by terminally differentiated B-cells is important in the immune response to pathogens. Its over production is a defining characteristic of many B-cell malignancies, including Waldenström Macroglobulinemia (WM), where elevated IgM is associated with significant morbidity and poor prognosis. Thus, the identification and characterization of the mechanisms controlling Ig secretion are of great importance for the development of future therapeutic approaches for these diseases. Here, we define a novel pathway involving the oncogenic transcription factor, GLI2, modulating IgM secretion via regulation of IL-6 receptor alpha subunit (IL6Rα) expression in WM cells. We have previously identified components of the Hedgehog (HH)-GLI pathway as modulators of Ig secretion. Pharmacological (GANT61) and genetic (shRNA) inhibition of GLI proteins resulted in no significant effect on cell proliferation or viability, while there was a significant reduction in IgM secretion (60%) in BCWM.1 (p<0.0001), (55%) in MWCL-1 (p<0.0001) and (50%) in RPCI-WM1 (p<0.0001) cells. Interestingly, this occurred independent of HH signaling as manipulation of HH had no effect on IgM secretion, cell growth or viability. Screening for a mechanism identified IL6Rα as a downstream direct target of GLI activity. GANT61 treatment significantly reduces IL6Rα promoter activity in BCWM.1 (p=0.0002), MWCL-1 (P=0.0003) and RPCI-WM1 (p<0.0001) cells. GLI2 knockdown using two independent shGLI2 constructs resulted in reduced IL6Rα mRNA expression (p<0.0001) determined by qPCR, and IL6Rα protein expression examined by FACS analysis. Similarly, GLI2 knockdown diminished IL6Rα promoter activity in BCWM.1 (p=0.0218), MWCL-1 (p=0.0008) and RPCI-WM1 (p=0.0002) cells. Using bioinformatics analysis, we identified three candidate GLI2 binding sites in the IL6Rα promoter region. Using chromatin immunoprecipitation assay (ChIP) followed by qPCR, we confirmed that GLI2 directly binds to the IL6Rα promoter region (-1294 / -1065). Finally, we were able to rescue the reduction in IgM secretion in GLI2 knockdown group by overexpressing IL6Rα (p=0.0142). Taken together, these data reveal a novel mechanism where GLI2 modulates IgM secretion in WM through the regulation of IL6Rα expression. Given the poor prognosis associated with elevated IgM in WM patients, components of this new signaling axis could be important therapeutic targets.

Disclosures
No relevant conflicts of interest to declare.
PD-1 Is Expressed on B-Cells in Waldenstrom Macroglobulinemia and Promotes Malignant Cell Viability and Proliferation
Authors: Ansell Stephen M. 
Published: October 2019

The tumor microenvironment plays an important role in regulating malignant cell growth and mechanisms to enhance anti-tumor immune function have been shown to improve patient outcome. Interactions between programmed death 1 (PD-1) and its ligands (PD-L1 and PD-L2) have been shown to be an important checkpoint in immune regulation. While it is well known that PD-1 is expressed on normal T cells and signaling through PD-1 inhibits T cell function, PD-1 is also expressed on a subset of B-cells but little is known about PD-1 signaling in B-cells. The goal of this study was to determine if the PD-1 is expressed on malignant B cells in Waldenstrom macroglobulinemia (WM) and whether this pathway plays a role in the survival and growth of malignant B cells in this B cell lymphoma.
Using flow cytometry, we found that the cell lines MWCL-1, BCWM.1 and RPCI, all derived from patients with Waldenstrom macroglobulinemia, expressed PD-1 to varying degrees on their cell surface. PD-1 expression in the cell lines was further confirmed by RT PCR analysis. Using flow cytometry and immunohistochemistry to examine bone marrow specimens from WM patients, we further confirmed PD-1 expression on CD19+ CD138+ malignant B-cells. Furthermore, intense staining for the ligands PD-L1 and PD-L2 was found by in bone marrows of WM patients when compared to normal bone marrow specimens. When WM cell lines are co-cultured with stromal cells engineered to express PD-L1 or PD-L2, there was a consistent increase in cell viability compared to controls. When malignant B cells from WM patients were co-cultured with stromal cells expressing the ligands, viability was unchanged but there was an increase in cell proliferation, most noticeably when cocultured with cells expressing PD-L2. To determine potential mechanisms that account for upregulation of PD-1 on malignant B-cells, we tested whether cytokines that promote WM cell growth and survival, including IL-6, IL-21 and BAFF, increased PD-1 expression. We found that WM cell lines and patient derived CD19+CD138+WM B-cells (n=4) treated with IL-21 demonstrated an increase in PD-1 expression compared to untreated controls.
We conclude that PD-1 is expressed on malignant B-cells in WM and that signaling through PD-1 may promote WM cell growth and survival. Blocking PD-1/PD ligand interactions may therefore be a potential therapeutic strategy in patients with Waldenstrom macroglobulinemia.

Disclosures
No relevant conflicts of interest to declare.
STAT3 Activation Is Preceded By Two Independent Pathways (BCR-BTK and IL6-JAK) in Mantle Cell Lymphoma
Authors: Park Hyebin , Zhao Donglu , Tsourdinis George , Ou Zhishuo , Tamayo Archito T. , Ford Richard J. , Fang Bingliang , Pham Lan V , Zhang Liang , Wang Michael 
Published: October 2019

Abstract
Introduction Mantle cell lymphoma (MCL) is an aggressive B-cell lymphoma with poor outcome and therapeutic challenge. Oral single-agent ibrutinib, a Bruton’s tyrosine kinase (BTK) inhibitor, elicited a response rate of 68% in phase II clinical trial and has been approved by FDA for the treatment of MCL patients who received at least one prior therapy. To increase the possibility of therapeutic potential, the investigation of BTK-dependent/independent signaling pathways is needed.
Methods and Results Using both established MCL cell lines and primary MCL cells as a model system, our data demonstrated that ibrutinib effectively inhibited BTK phosphorylation along with quick STAT3 inactivation within 30 minutes of ibrutinib incubation at a dose lower than 100nM. Since the results clearly indicated that ibrutinib inhibited both BTK and STAT3 activation in MCL cells, we next elucidated the function and action between BTK and STAT3. Using a validated BTK-specific siRNA, we knocked down BTK to test the legitimacy of the relationship between BTK and STAT3. The results showed that transient knockdown of BTK significantly inhibited STAT3 phosphorylation in MCL cells. Next, the results from both immunoprecipitation and confocal microscopy showed that STAT3 was BTK-associated transcription protein indicating that BTK could function as a kinase upstream of STAT3, in a similar manner to the JAK/STAT pathway. Since STAT3 is predominately known as the downstream protein of the IL-6/JAK pathway, we examined whether there is a cross-talk between the BTK-STAT3 and the JAK-STAT3 pathways in MCL cells. After stimulation of MCL cells with IgM or IL-6, ibrutinib only inhibited IgM-induced STAT3 activation but not IL-6-induced STAT3 activation. Even with an increased dose of ibrutinib, the basal level of STAT3 phosphorylation remains detectable in MCL cells due to IL-6 autocrine. However, ibrutinib plus JAK inhibitor completely inactivated STAT3 and synergistically inhibited the growth of MCL cells. These data indicate that there are two independent pathways, BCR-BTK and IL6-JAK, which lead to STAT3 activation without cross-talk in MCL cells.
Conclusions Our results may lead to the development of more effective combination therapy to block both BCR-BTK and IL-6-JAK signaling pathways for relapsed or refractory MCL.

Disclosures
Wang: Pharmacyclics: Honoraria, Research Funding.