bluuebunny/crossref_metadata_2025_split huggingface dataset:
p38 MAPK Mediates Inhibition of Activation Induced Cell Death in T Lymphocytes Via Upregulation of Bcl-xL and FLIPshort upon Ligation of CD137/4-1BB or CD28.
Authors: Scholz Christian , Stärck Lilian , Lehmann Mario , Dörken Bernd , Daniel Peter T. 
Published: April 2020

Abstract
Costimulation is essential for the induction of proliferation in naive T cells and for the inhibition of activation induced cell death (AICD) in activated T lymphocytes. While costimulatory signals mediated through the immunglobulin family member CD28 play a prominent role during primary T cell activation, ligation of the tumor necrosis factor receptor family member CD137/4-1BB is more important during late primary and secondary T cell activation. Signals mediated through either costimulatory protein block AICD. Inhibition of AICD through ligation of CD137/4-1BB or CD28 involves upregulation of Bcl-xL and FLIPshort (Eur J Immunol 2005, 35: 1257–66). We further demonstrated that costimulatory signals mediated through CD137/4-1BB or CD28 depend on the activity of phosphatidylinositol 3-kinase and AKT/protein kinase B, two kinases that had formerly been implied in CD28-induced signaling, indicating that CD28- and CD137/4-1BB-mediated signals share downstream signaling pathways. Here, we demonstrate that p38 mitogen-activated protein kinase (MAPK) mediates CD137/4-1BB-induced as well as CD28-mediated costimulation of cell proliferation and inhibition of AICD. This coincides with upregulation of Bcl-xL and FLIPshort. Inhibition of p38 MAPK abrogates T cell receptor induced proliferation and antagonizes costimulation mediated survival. Thus, p38 MAPK, which was previously thought to be primarily involved in CD137/4-1BB-mediated signaling, is similarly important for CD28-induced costimulation and survival. This indicates that, while involving different protein families, signal transduction by CD28 and CD137/4-1BB depends on a common upstream and downstream network of survival kinases.
Phase I Trial of Siplizumab in CD2-Positive Lymphoproliferative Disease.
Authors: O’Mahony Deirdre , Morris John C. , Moses Leslie , O’Hagan Diana , Gao Wendy , Stetler-Stevenson Maryalice , Taylor Margaret , Hammershaimb Luz , Waldmann Thomas A. , Janik John E. 
Published: April 2020

Abstract
Siplizumab is a humanized IgG1κ class monoclonal antibody that binds to the CD2 receptor on human T- and NK-cells. In an animal model of adult T-cell leukemia/lymphoma (ATL), fifty percent of animals survived tumor challenge with 4 weeks of siplizumab treatment and the life-span of tumor bearing animals treated for six months was equivalent to that of animals not challenged with tumors. A single-center phase I dose escalation trial to assess maximum tolerated dose (MTD) and safety in patients (pts) with CD2-positive adult T-cell leukemia (ATL), cutaneous T-cell lymphoma (CTCL), peripheral T-cell lymphoma (PTCL), and large granular lymphocyte leukemia (LGL) is ongoing. Eligibility includes Karnofsky performance status ≥70%; life expectancy &gt;2 months; appropriate hematological status and normal organ function; prior treatment with chemotherapy and monoclonal antibodies is allowed. Cohorts of 3 pts each receive escalating i.v. doses of siplizumab ranging from 0.4 to 4.8 mg/kg administered over 2–3 days per treatment week every other week for 16 weeks or until unacceptable toxicity or disease progression (PD). 16 pts have been enrolled into 5 cohorts: 0.4 (3 pts), 0.6 (3 pts), 0.8 (3 pts), 1.2 (4 pts) and 2.4 (3 pts) mg/kg per week with planned dose escalation to 3.4 and 4.8 mg/kg. Median number of courses received is 4 (range 1–8). Diagnoses include ATL (9), LGL (4), PTCL (1) and CTCL (2). Grade 1/2 infusional reactions primarily manifested as fever and chills were confined to the first dose of treatment in the majority of patients. Meperidine pretreatment significantly ameliorated infusional reactions. The median (range) percentage decrease in CD4, CD8, NK and malignant cell numbers in peripheral blood from baseline are 98(71–100%), 93(50–100%), 89(55–96%) and 88 (0–100%), respectively. No DLTs have occurred at this time. To date, 3 confirmed PRs have been observed (2 ATL, 1 LGL), 6 pts had stable disease, and 7 pts had PD. 1 pt discontinued therapy due to a siplizumab-related adverse event of polymyalgia rheumatica and 3 pts (2 ATL, 1 LGL) were removed due to CMV antigenemia (which was an off-treatment criterion at the time of study drug discontinuation). 4 patients have died during the one-year follow up period due to PD and 4 patients have completed all 8 courses of treatment. In conclusion-siplizumab has been well tolerated in this trial and the maximum tolerated dose has not been reached. The protocol has been amended to allow for treatment of CMV antigen positive patients provided oral antivirals are effective in preventing CMV disease and rising CMV levels. Anti-tumor activity has been observed in some patients. Enrollment in this study continues.
CTGF (CCN2) Predicts OS and DFS in Adult Acute Lymphoblastic Leukemia.
Authors: Sala-Torra Olga , Gundacker Holly M. , Stirewalt Derek L. , Ladne Paula A. , Pogosova-Agadjanyan Era L. , Slovak Marilyn L. , Willman Cheryl L. , Heimfeld Shelly , Boldt David H. , Radich Jerald P. 
Published: April 2020

Abstract
Outcome of adult acute lymphoblastic leukemia (ALL) continues to be poor, and parameters to better discriminate patients with distinct prognosis are necessary. In studies comparing global gene expression differences between normal hematopoietic cells (whole bone marrow, peripheral blood, CD34+, and CD22+ sorted populations) and ALL cells using microarrays we found that the B-ALL cells showed evidence of increased expression of Connective Tissue Growth Factor (CTGF). The median log 2 transformed signal intensity of CTGF was 4.26 (range 3.95–4.76) in normal hematopoietic cells, and 6.59 (range: 3.85–10.62) in all leukemic samples; this difference in signal intensity is equivalent to a 5-fold increase in median expression of CTGF in leukemic cells. Therefore, we hypothesized that expression level of CTGF may have prognostic significance in adult ALL. Using real-time RT-PCR assays for CTGF we examined the expression of CTGF in 79 diagnostic ALL patients from SWOG protocol S9400 (28 bone marrow and 51 peripheral blood samples). Patients with L3 ALL were excluded from the study. The median age of patients was 35 (range 17–64), with the median WBC 23,400/ul (range 600–396,600), and peripheral blood blasts 56% (range: 0–98). Fifty patients had B-ALL (63%), 13 (16%) had T-ALL and lineage was unknown for 16 (20%). When treated as a continuous variable in a logistic regression model, the level of CTGF expression was significantly associated with inferior OS and DFS (p=0.007 and p=0.0012, respectively). When controlled for WBC and cell lineage, the association of CTGF with OS and DFS remained statistically significant. We then sub-grouped the ALL patients into three equal groups (tertiales) based on CTGF expression. This subgroup analysis found that the OS for patients in the highest tertile (highest CTGF expression) was approximately 11% (95% CI 0–24) at 5 years, as compared to 42% (95% CI 23–61) and 58% (95% CI 38–78) for patients with middle and low CTGF expression respectively (figure). In sub-analysis of patients with B-lineage ALL (n=50), the association of CTGF expression with OS and DFS was still statistically significant (p=0.009 and p=0.005) when treated as a continuous variable. This report is an example where a gene expression study detected a gene differentially expressed in leukemia, with clear clinical value. Moreover, this is the first report that correlates the level of expression of CTGF with outcome in ALL patients. We are actively pursuing the biological and clinical significance of CTGF in other ALL patients and model systems.
Figure Figure
Inhibition of Mutant FLT3 Activation by the Novel Tyrphostin, AGS324.
Authors: Williams Allen B. , Gazit Aviv , Nguyen Bao , Slavin Shimon , Small Don 
Published: April 2020

Abstract
FLT3 is a member of the class III tyrosine kinase family, consisting of five immunoglobin-like extracellular domains, a single transmembrane domain followed by a short juxtamembrane region and an interrupted kinase domain. Constitutive activation of FLT3 through mutation occurs in about 30% of AML cases. Studies show that targeted inhibition of FLT3 by small molecule tyrosine kinase inhibitors results in clinical responses in some patients. In light of the finding of resistant mutants selected by Gleevec treatment in CML, it is likely that similar mutants will arise in FLT3. Thus, the need for development of additional FLT3 inhibitors will be important to overcome this resistance. Here, we investigate a series of compounds derived from AG1295 (a FLT3 inhibitor with an IC50 of 300–500 nM) for activity against FLT3. Of these, AGS324 exhibited the most potent activity against FLT3 ITD in transfected BaF3 cells. FLT3 ITD phosphorylation was completely inhibited by treatment with AGS324 with an IC50 of ~40 nM. Likewise, downstream STAT5 and MAP kinase phosphorylation were reduced in parallel to inhibition of FLT3 activation. AGS324 inhibited proliferation of BaF3 FLT3 ITD expressing cells with an IC50 of 60 nM. IL-3 could completely rescue BaF3 ITD cells from AGS324 mediated cytotoxicity even at 10 uM of inhibitor, indicating no interference with IL-3 signaling pathways. There was also no activity against proliferation of BaF3 parental cells. Like AG1295, it showed greatly reduced activity against the D835Y point mutant for inhibition of FLT3 phosphorylation (IC50 &gt;5 uM) and proliferation (IC50 &gt; 10 uM). Not all cells expressing kinase domain point mutants were resistant to inhibition by AGS324. Cells expressing the D835G mutation were inhibited in a similar fashion to BaF3 ITD cells. In addition cells expressing a FLT3 Y842E activating mutation were also inhibited by AGS324. Proliferation of MV4-11 cells, derived from an AML patient, which express a FLT3 ITD mutation, was also inhibited with a similar IC50 (~80 nM). Interestingly, SEM-K2 cells, which express amplified wild-type FLT3 were relatively resistant to inhibition of proliferation and activation of FLT3 by AGS324. Several other compounds that resulted from modifications to AG1295 showed varying degrees of potency against FLT3. Taken together, these findings indicate that AGS324 is a potent inhibitor of FLT3 ITD and some kinase domain point mutations but has reduced activity against wtFLT3. Some structural modifications of AG1295 greatly increase potency against FLT3 ITD as well as some kinase domain mutations. We present some SAR data for this group of tyrphostins, which may be useful for more specific targeting of mutant FLT3.
The CCR1 Antagonist BX470 Inhibits the Growth of Multiple Myeloma (MM) Cells That Produce MIP-1α.
Authors: Lentzsch Suzanne , Anderson Gulsum , Cuiling Li , Richard Horuk , Mapara Markus Y. , Irene Ghobrial , Roodman David G. 
Published: April 2020

Abstract
Macrophage inflammatory protein-1alpha (MIP-1α) is a key factor in the pathogenesis of MM. MIP-1α is a growth and survival factor for MM (Lentzsch et al., Blood 2003), stimulates osteoclast formation, increases adhesion of MM cells to stromal cells and induces bone resorption and lytic lesions in patients with MM (Choi et al., JCI 2001). High levels of MIP-1α are present in the marrow of 70% of MM patients, and MIP-1α levels correlate with increased bone destruction, tumor burden and a poor prognosis in MM patients (Uneda et al., Br J Haematol 2003). MIP-1α binds to the chemokine receptors CCR1 and CCR5, which are expressed on myeloma cells as well as on osteoclasts. Therefore, targeting MIP-1α mediated effects on myeloma cells as well as on osteoclasts by blocking its receptors is a novel target for treating the majority of MM patients. BX471 is a potent and selective antagonist of CCR1 that inhibits the binding of MIP-1α to CCR1. BX471 inhibits OCL formation (Oba et al., Exp. Hematology 2005) and is currently being studied in phase II trials for multiple sclerosis. However it is unknown if BX471 effects all MM cells or only those MM cells that produce MIP-1α.
Secretion of MIP-1α of the MM cell lines (MM.1S, OPM 2, RPMI 8226) was measured by Bio-Plex Cytokine Assay. All cell lines were exposed to serial dilutions of BX 471 (10–1000 nM) for 48 hours and thymidine uptake was measured to assess inhibition of proliferation. CCR1 expression on MM cell lines was detected by PCR.
All MM cell lines expressed CCR1. OPM 2 and MM.1S secreted high amounts of MIP-1α within 48hours (2,032 pg/mL and 4,388 pg/mL, respectively). Secretion of MIP-1α by RPMI 8226 MM cells was not detectable. Significant dose-dependent inhibition of proliferation by BX471 was seen with MM.1S and OPM 2 MM cells (40% and 46%, respectively). In contrast RPMI 8226, which did not secret MIP-1α was not inhibited by BX 471 up to 1000 nM. These data show that blocking CCR1 induces significant growth inhibition of MIP-1α producing MM cells and underscore the relevance of MIP-1α as an important autocrine growth and survival factor in MM.
This study provides the framework for clinical evaluation of BX 471 in a phase II trial for patients with MM and supports the hypothesis that BX471 targets both the tumor and osteoclastic activity in MIP-1α producing MM cells and suggests that BX471 should be an effective treatment for the majority of MM patients.
Multiple Myeloma as Target for γδ T Cell Mediated Immunotherapy - Expression of the Putative Vγ9Vδ2-TCR Ligand F1-ATPase on Myeloma Cells.
Authors: Kunzmann Volker , Engert Judith , Kimmel Brigitte , Wilhelm Martin , Einsele Hermann 
Published: April 2020

Abstract
Activated Vγ9Vδ2 T cells, the major γδ T lymphocyte subset in humans, show cytolytic activity against various tumor cells. However, tumor antigens recognized by the TCR remained unkown so far. Recently, the ectopic surface expression of the F1-ATPase, normally expressed on the internal membrane of mitochondria, was implicated in tumor recognition of Vγ9Vδ2 T cells (Scotet E. et al., Immunity2005; 22:71–80). Surface expression of the a chain of the F1-ATPase (recognized by monoclonal antibody 7H10) strongly correlates with susceptibility of tumor cells against Vγ9Vδ2 T cell lysis. Different functions have been attributed to the ectopic expression of the F1-ATPase on the cell surface, including an immunoregulatory role induced by cell stress, receptor for angiostatin or regulation of lipoprotein transport through high-affinity apolipoprotein A-I binding. In this study we evaluated the surface expression of this F1-ATPase on hematopoetic tumor cell lines and on primary tumor cells from hematological malignancies. As already shown, the a subunit of F1-ATPase was clearly detected on several tumor cell lines which are consistently killed by activated Vγ9Vδ2 T cells (Daudi, K562, RPMI 8226), whereas the known Vγ9Vδ2 T cell resistant tumor cell lines (Raji, Jurkat) did not express detectable levels of the F1-ATPase. Analysis of 42 primary hematopoetic tumor cells (21 myeloma, 17 AML, 4 B-NHL) revealed frequent expression of F1-ATPase on primary myeloma cells (14/19 positive), whereas primary AML blasts (3/17 positive) and primary NHL cells (1/4 positive) expressed the putative Vγ9Vδ2-TCR ligand F1-ATPase less frequently. To further evaluate the functional role of F1-ATPase expression in Vγ9Vδ2 T cell mediated recognition of myeloma cells, cytotoxicity assays were performed. The mAb against the a subunit of F1-ATPase significantly decreased in vitro lysis of myeloma cells lines and primary myeloma cells by activated Vγ9Vδ2 T cells. These results suggests Vγ9Vδ2 TCR-dependent interactions between myeloma cells and Vγ9Vδ2 T cells and indicate that multiple myeloma should be considered as a major target for γδ T-cell mediated immunotherapy.
Stimulation with K562 Cells Transfected with 4-1BBL and IL-15 Expands and Activates Natural Killer (NK) Cells with Specific Cytotoxicity for Multiple Myeloma (MM).
Authors: Shi Jumei , Tricot Guido , Szmania Susann , Camet Cristyn , Rosen Nancy , Cottler-Fox Michele , Barlogie Bart , Campana Dario , van Rhee Frits 
Published: April 2020

Abstract
Introduction: Although stem cell transplant (PBSCT) supported high dose chemotherapy can induce remission in MM patients with high risk features (e.g. high CKS1-B expression and abnormal cytogenetics) there is a high rate of relapse. Immunologic therapies can augment high dose chemotherapy by eradicating chemo-resistant disease. We have previously established that KIR-ligand mismatched NK cells from haplo-identical donors are cytotoxic to primary MM cells. In this study we investigate whether co-incubation of NK cells with irradiated K562 cells transfected with 41BBL and membrane-bound IL15 (K562-41BBL-mIL15) could expand NK cells and augment cytotoxicity to primary MM cells.
Methods: Peripheral blood mononuclear cells (PBMC) of normal donors were co-cultured with irradiated K562-41BBL -mIL15 at a 1.5:1 ratio with varying concentrations of IL2 and re-stimulated on day 7. The cultures were then analyzed for proliferation, expansion, immunophenotype and cytotoxicity.
Results: By testing a range of IL2 concentrations (10–300 IU/ml) we first established that 100IU of IL2/ml induced optimal proliferation in H3 thymidine uptake assays and this concentration was used in all subsequent experiments. After two weeks PBMC co-cultured with K562-41BBL-mIL15 were enriched for NK cells (93%) and contained few T cells (0.8%) compared to PBMC cultured with IL2 alone (NK cells 11.9% and T cells 58.7% respectively). In absolute numbers there was as 60-fold (±0.6) expansion of NK cells in the K562-41BBL -IL15 cultures compared to only a 1.5-fold expansion of NK cells cultured with IL2 alone. NK cells were analyzed by flow cytometry for expression of KIR2DL1, KIR2DL2/3, and KIR3DL1 pre- and post-incubation with K562-41BBL-mIL15 and we observed no change in NK immunophenotype. 51Cr release assays of expanded NK cells showed specific killing of K562 cells (84±4%), the MM cell line U266 (88±3%), and primary MM cells (58±9%), without killing of non-myeloma patient cells (PHA-blasts) or autologous cells at a ratio of 7 NK effectors to 1 target cell. Expanded NK cells achieved much higher specific lysis and at lower E:T ratios of primary MM cells when compared side-by-side with non-expanded NK cells.
Conclusion: K562-41BBL-mIL15 transfectants stimulated vigorous expansion of NK cells without expanding T lymphocytes. Analysis of the KIR repertoire showed that there was no change in NK cell subpopulations after expansion. The expanded NK cells were highly active and killed patient MM cells better than non-expanded NK cells without significant lysis of normal cells. Expanded/activated NK cells may prove especially helpful in treating patients with relapsed/refractory MM who have a high tumor burden.
Downregulation of PU.1 Is Required for Subtype of Multiple Myeloma.
Authors: Tatetsu Hiro , Hata Hiroyuki , Yamada Yasuhiro , Mitsuya Hiroaki , Okuno Yutaka 
Published: April 2020

Abstract
There are several recent reports that certain mutations in critical transcription factors could be associated with leukemogenesis; however, it remains unclear whether such mutations could be linked to the pathogenesis of multiple myeloma (MM). In the present study, we attempted to determine whether mutations in transcription factors could be found in the patients with MM, utilizing MM cell lines and freshly isolated MM cells, purified with CD138 antibody and magnetic beads. When we looked at the expression of Blimp-1, XBP-1, NF-kB (p65 and p50), and PU.1 using semi-quantitative RT-PCR, all except PU.1 were found expressed in all MM cell lines and freshly isolated MM cells examined. All the PCR products were sequenced, but no significant mutations were identified. As examined with RT-PCR, PU.1 was found completely downregulated in 6 of 8 MM cell lines, while only faint to no expression of PU.1 was seen in 12 of 41 freshly isolated MM cells. As PU.1 message was sequenced, no mutations were found in 29 PU.1-positive MM cells or 2 MM cell lines that had relatively high PU.1 expression. Considering that PU.1 is essential for myeloid and lymphoid differentiation and that mice with null mutation in the PU.1 gene have no granulocytes, monocytes/macrophages or B lymphocytes, together with a recent report by others that AML developed in mice with PU.1 downregulation by 20%, we asked whether PU.1 downregulation might be associated with the oncogenesis or maintenance of MM. To examine the effects of PU.1 expression on MM cells, we generated tet-off conditional PU.1 expression model of PU.1-negative U266 MM cell line. Surprisingly the induction of PU.1 expression resulted in cell cycle arrest and apoptosis of those cells. Cell cycle analysis using flow cytometry revealed that PU.1-expressing U266 cells were in the G1 arrest. May-Giemsa staining revealed that such cells were swollen, enlarged, and vacuolous. These changes were completely reverted when the expression of PU.1 was silenced by tetracycline addition. There was no change in expression levels of cell cycle-related genes (p27, cyclin D1, cyclin E) and apoptosis-related genes (Bcl-2, Bcl-XL, and A1), while caspase3 cleavage was observed by 72 hr following PU.1 induction. We are currently examining the mechanism(s) of PU.1 downregulation in MM cells and a downstream cascade of PU.1 expression during cell death.
Pathogen-Associated Molecular Patterns Are Growth and Survival Factors for Human Myeloma Cells through Toll-Like Receptors.
Authors: Jego Gaetan , Pellat-Deceunynck Catherine , David Catherine , Regis Bataille 
Published: April 2020

Abstract
Multiple Myeloma (MM) patients are strongly sensitive to bacterial, fungal and viral infections. Furthermore, MM is often newly diagnosed in the context of such infections. Given those recurrent infections remain a major cause of death of MM patients; we surmised that MM plasma-cells could be activated by microorganisms, therefore contributing to the initiation and progression of the disease. Microorganisms share highly conserved structures called pathogen-associated molecular patterns. They are recognized by a family of receptors that act as sensor for the innate immune system and are called the Toll-like receptor family (TLRs). We first measured the expression of the 10 known human TLRs on 16 human MM plasma-cells lines (HMCLs) and freshly purified Plasma-cells from 13 patients. The expression pattern is heterogeneous among HMCLs and does not correlate with the one of B cells. Indeed TLR-3, 4, and 8 are aberrantly expressed. On the contrary, the expression of TLR-2 and 10 is lost on most of the HMCLs. TLR-1, 7 and 9 are the most frequently expressed (15+/16, 12+/16 and 11+/16 respectively). Primary MM plasma-cells also express TLR-7 (9+/13) and TLR-9 (8+/13). Accordingly to this expression profile, culture with TLR-7 ligand (loxoribine) or TLR-9 ligand (hypomethylated DNA from bacteria) increased 1,7 to 6 times (mean 3 ± 1,4 n= 8) the proliferation of IL-6-dependent and independent HMCLs. Furthermore, we observed a resistance to serum-deprivation as well as to dexamethasone-induced apoptosis. Those effects were IL-6-mediated in IL-6-dependent HMCLs since a blocking antibody to IL-6 neutralized the growth and survival induced by TLR triggering. In conclusion, human MM Plasma-cells express a broad range of TLRs and the triggering of TLR-7 and 9 induces tumor cell growth and prevent chemotherapy-induced apoptosis. These effects are mediated by the induction of an autocrine loop of growth factors as IL-6, and others currently under identification in the case of IL-6 independent HMCLs. Thus, MM plasma-cells take advantage of infections to expand and escape to usual therapies.