bluuebunny/crossref_metadata_2025_split huggingface dataset:
Targeting of alpha4beta1 Integrin and CD4/CD8 on Human T Cells, in Addition to CD3 and CD28, Induces Maximal Activation, as Assessed by Single-Cell Analysis of MAP Kinase Pathway Activation and Cytokine Production.
Authors: Kim Tae Kon , Billard Matthew J. , Wieder Eric D. , McIntyre Bradley W. , Komanduri Krishna V. 
Published: April 2020

Abstract
Optimal T cell activation requires the formation of immunological synapses between T cells and antigen-presenting cells (APC). Immunological synapse formation involves the binding of ligands on APC to co-stimulatory receptors on T cells, resulting in maximal activation. Most prior in vitro studies examining the process of T cell activation have utilized immobilized mAbs or ligands to assess the roles of co-stimulatory molecules in T cell activation. Micro-domain formation in such models may be inflexible, potentially yielding misleading results about the relative importance of individual costimulatory pathways. To more physiologically mimic immunologic synapse formation, we stimulated T cells with soluble primary mAbs that were then cross-linked by secondary antibodies. Specifically, we induced cross-linking of surface proteins on purified human T cells using a combination of mAbs recognizing four potential co-stimulatory receptors (CD3, CD4 or CD8, CD28 and VLA4/a4b1 integrin), and assessed phospho-Erk1/2 and cytokine production at a single cell level using flow cytometry. Consistent with the predictions of the Bretscher-Cohn two-signal model, CD28 induced a modest increase in Erk1/2 phosphorylation (in CD4) and IL-2 production (in CD4+ and CD8+ T cells) and IFNg (in CD8+ T cells), while low dose (0.1mcg/ml) anti-CD3 mAb alone failed to induce significant activation (P&lt;0.05). However, CD28 stimulation consistently augmented activation in both CD4+ and CD8+ T cells in the presence of anti-CD4 and anti-CD8 mAbs (P&lt;0.05). More interestingly, stimulation by CD4 or CD8 mAbs induced an additive effect on Erk1/2 phosphorylation and IL-2 and IFNg production regardless of CD28 stimulation (P&lt;0.05). In addition, stimulation via a4b1/VLA4 increased the level of T cell activation in the presence of three distinct signals in both CD4+ T cells and also in CD8+ T cells (P&lt;0.05). We then examined the dependence of T cell activation on all four types of stimuli (i.e., via CD3, CD28, CD4 or CD8, and VLA4). Following stimulation with low-dose anti-CD3 mAb (0.1mcg/ml), the extent of Erk1/2 phosphorylation and IL-2/IFNg production was found to be dependent on the numbers of stimulatory signals received through all four pathways in a statistically meaningful manner (see Figure). In conclusion, optimal T cell activation requires not only CD3 and CD28, but also signaling via CD4/CD8 and VLA4, supporting a “four-signal” model of T cell activation. These data suggest that
additional co-stimulations through a4b1/VLA4 and CD4 or CD8 may be necessary to induce optimal T cell signaling, targeting of a4b1 and CD4/CD8 by specific agonists or antagonists may have therapeutic benefit in immunomodulation (e.g., augmentation of vaccine responses and/or abrogation of pathogenic T cell activation).
Figure Figure
Telomere Elongation in B-Cells Is Independent of Class Switching.
Authors: Roeth Alexander , de Beer Dirk , Seifert Marc , Mueller Astrid , Duehrsen Ulrich , Kueppers Ralf , Baerlocher Gabriela M. 
Published: April 2020

Abstract
BACKGROUND: In contrast to human granulocytes and T-cells with a quite homogenous decrease in telomere lengths over age, telomere lengths of peripheral blood B-cell populations are highly heterogeneous with average telomere lengths of B-cells remaining relatively constant from middle age onward (Baerlocher et al, J. Leuk. Biol. 2003). So far, telomere elongation has been described in highly proliferating germinal center B-cells during the development from naive B-cells to memory B-cells (Norrback et al, Eur J Haematol 2001). During this same time period the process of class-switch recombination (CSR) occurs. Our aims were to analyze the telomere lengths in different B-cell subsets in order to elucidate telomere length dynamics in relationship to CSR.
PATIENTS and METHODS: Buffy coats from 14 healthy donors were enriched for CD19+ B cells by magnetic cell separation. Naive B cells (IgM+/IgD+/CD27−), IgM-only B cells (IgM+/IgD−/low/CD27+), double-positive B cells (IgM+/IgD+/CD27+) and class-switched memory B cells (IgM−/IgD−/CD27+) were further separated by cell sorting. Telomere length of sorted B-cell subpopulations was measured by automated multicolour flow-FISH.
RESULTS: Naive B-cells presented the shortest telomere length values (average telomere length, n=14: 7.2 kb ± 0.7 kb) compared to the other B-cell subsets. In comparison to the naive B-cell subset, the IgM only B-cell subset had 13% longer telomeres (average telomere length, n=14: 8.1 kb ± 1.3 kb), the double-positive B-cell subset had 10% longer telomeres (average telomere length, n=14: 7.9 kb ± 0.8 kb) and the memory B-cell subset had 22% longer telomeres (average telomere length, n=14: 8.7 kb ± 1.1 kb) (p &lt; 0.0001).
CONCLUSIONS: We are able to confirm longer telomeres in memory B cells than in naive B cells. For the first time, however, we can demonstrate that longer telomeres are also found in non-class switched B-cells. Based on these results telomere elongation does not coincide with the process of CSR. Additional studies are needed to assess whether telomere elongation can only take place in the germinal center or whether certain B-cell subsets are able to elongate their telomeres independent from the germinal center.
Characterization of MDX-1401, a Human Anti-CD30 Antibody with Enhanced Effector Function, for Therapy of Malignant Lymphoma.
Authors: Cardarelli Pina M. , Loomis Cristina , Preston Ben , Black Amelia , Passmore David , Chen Tseng-Hui , Chen Sharline , Liu Jie , Kuhne Michelle R , Srinivasan Mohan , Assad Albert , Witte Alison , Coccia Marco , Graziano Robert F. , King David J. 
Published: April 2020

Abstract
Therapeutic monoclonal antibodies kill target cells by multiple mechanisms including antibody-dependent cellular cytotoxicity (ADCC), antibody-dependent phagocytosis (ADP), complement-dependent cytotoxicity (CDC), and direct induction of apoptosis. Antibody binding to FcgRIIIA (CD16), which is expressed on NK cells, macrophages, and CD8+ cells, is essential for ADCC. MDX-1401 is a fully human monoclonal antibody of IgG1 (kappa) isotype that binds to human CD30. This second generation anti-CD30 antibody was derived from parental antibody MDX-060 but differs in that the oligosaccharides of the IgG1 lack fucose, a property that conveys increased antibody affinity for Fc receptor CD16 (FcgRIIIa) and thus stimulates both more potent and efficacious ADCC than a fucosylated IgG1. The KD of the parental antibody for CD30 expressed on L540 Hodgkin’s lymphoma cells is approximately 1.4 nM while the KD of MDX-1401 is 1.9 nM, demonstrating that binding affinity for antigen are nearly identical. However, the EC50 for MDX-1401 binding to CD16-transfected cells is approximately 3 nM compared to barely detectable binding by parental antibody, confirming that the absence of fucose conveys increased affinity for FcgRIIIa. Data is presented that demonstrates MDX-1401 has significantly improved potency and efficacy in an ADCC assay as evidenced by a decrease in EC50 as well as an increase in maximum specific lysis. Importantly, the enhanced ADCC activity is observed among a large panel of cell lines with varying numbers of CD30 receptors per cell, including one cell line with low antigen expression in which parental antibody failed to induce ADCC. MDX-1401 enhances ADCC activity with all polymorphic variants including lower affinity FcgRIIIa Phe/Phe158 and FcgRIIIa Phe/Val158 effector cells. Furthermore, MDX-1401 is efficacious in inhibiting growth of CD30+ tumor xenografts in mice. The low doses of antibody required for ADCC activity irrespective of donor genotype, the capacity to mediate ADCC of target cells expressing low levels of CD30, and increased in vivo efficacy support the development of MDX-1401 for treatment of malignant lymphoma. Phase 1 studies in subjects with Hodgkin’s lymphoma are currently underway.
Bortezomib-Doxorubicin-Dexamethasone as Induction Prior to Reduced Intensity Autologous Transplantation Followed by Lenalidomide as Consolidation/Maintenance in Elderly Untreated Myeloma Patients
Authors: Palumbo Antonio , Falco Patrizia , Gay Francesca , Montefusco Vittorio , Crippa Claudia , Patriarca Francesca , Gilestro Milena , Liberati Anna M. , Rossini Fausto , Caravita Tommaso , Falcone Antonietta , Cavallo Federica , Corradini Paolo , Rossi Giuseppe , Boccadoro Mario 
Published: April 2020

Abstract
Background: New agents have been introduced as induction prior to autologous stem cell transplant (ASCT) and as consolidation/maintenance thereafter to improve complete response (CR) rates. In this trial we evaluate Bortezomib plus Pegylated-lyposomal-doxorubicin and Dexamethasone (PAD) as induction therapy prior to reduced intensity ASCT, followed by consolidation with Lenalidomide and Prednisone (LP) and maintenance with Lenalidomide alone (L).
Methods: Newly diagnosed multiple myeloma (MM) patients aged 65–75 years were eligible. Induction regimen consisted of 4 21-day PAD cycles (Bortezomib 1.3 mg/m2 days 1, 4, 8, 11, Pegylated-lyposomal-doxorubicin 30 mg/m2 day 4 and Dexamethasone 40 mg days 1–4, 8–11, 15–18). Two cycles of Cyclophosphamide 3 g/m2 plus Granulocyte-Colony Stimulating Factor were used to harvest stem cells. Patients were conditioned with tandem Melphalan 100 mg/m2 (MEL100) followed by stem cell support. After ASCT patients received consolidation with 4 28-day LP cycles (Lenalidomide 25 mg days 1–21 plus, Prednisone 50 mg every other day) followed by Lenalidomide alone maintenance (10 mg days 1–21 every 28 day). Primary objectives were safety (grade 3 non-hematologic toxicity &lt; 30%) and efficacy (near CR rate &gt; 35%).
Results: One-hundred and two patients have been enrolled. After PAD cycles at least partial response (PR) rate was 94%, at least very good partial response (VGPR) was 59% including 13% CR. After tandem MEL100, 88% of patients achieved at least VGPR and 41% CR. After LP consolidation all patients obtained PR, 88% at least VGPR and 53% immunofixation negative CR. After a median follow-up of 14 months, 1-year progression free survival (PFS) was 92%, 1 year time to progression was 97% and 1 year overall survival was 92%. PFS was not significantly affected β2-microglobulin levels (p=0.10), presence of chromosome 13 deletion (p=0.5) or t(4;14) (p=0.61).
During PAD, grade 3–4 adverse events included thrombocitopenia (13%), neutropenia (11%), infections (18%), gastrointestinal toxicities (12%), peripheral neuropathy (11%) and deep vein thrombosis (6%). During LP consolidation, grade 3–4 toxicities included neutropenia (18%), thrombocytopenia (6%), infections (6%) and deep vein thrombosis (6%). The other grade 3–4 toxicities occurred in less than 5% of patients.
Conclusions: Bortezomib as induction regimen prior to reduced intensity ASCT, followed by Lenalidomide as consolidation maintenance is a highly effective regimen in elderly patients. Updated results will be presented at the meeting.
Molecular Mechanism by Which Rituximab Sensitizes B-NHL Cells to TRAIL Apoptosis: Induction of RKIP and DR5 Expression Via Inhibition of NF-Kb, Snail, and YY1.
Authors: Vega Mario I. , Martinez-Paniagua Melisa , Huerta-Yepez Sara , Kam Yeung , Baritaki Stavroula , Bonavida Benjamin 
Published: April 2020

Abstract
There have been significant advances in the treatment of patients with B-NHL using combination of rituximab and CHOP. However, a subset of patients does not initially respond or develop resistance to further treatments; hence, the need for alternative therapies to overcome resistance. TRAIL and agonist DR4/DR5 monoclonal antibodies have been examined clinically against a variety of tumors in Phase I/II. However, the majority of B-NHL derived from patients and cell lines are resistant to TRAIL-induced apoptosis. Recent findings demonstrated that treatment of TRAIL-resistant-B-NHL with rituximab sensitizes the tumor cells to TRAIL apoptosis. The underlying mechanism of rituximab-induced sensitization to TRAIL, however, is not clear. We have recently reported that treatment of tumor cells with sensitizing agents (example CDDP, proteasome inhibitors) resulted in the reversal of resistance to TRAIL via induction of Raf-1 kinase inhibitor protein (RKIP) and demonstrated the pivotal role of RKIP in the regulation of tumor cell sensitivity to TRAIL. Hence, since rituximab induces the expression of RKIP in B-NHL, we determined the role of RKIP induction by rituximab in the sensitization of B-NHL to TRAIL apoptosis. Various B-NHL cell lines were used as models for study. Treatment of B-NHL cells with rituximab (20 ng/ml) and TRAIL (5–10 ng/ml) resulted in significant potentiation of apoptosis and synergy was achieved. Rituximab induced the expression of RKIP as determined by RT-PCR and western concomitantly with inhibition of NF-kB. The inhibition of NF-kB resulted in upregulation of RKIP expression and was mediated, in large part, by inhibition of the transcription repressor Snail (downstream of NF-kB). Further, RKIP-induced inhibition of NF-kB by rituximab resulted in downstream inhibition of the DR5 transcription repressor Yin Yang 1 (YY1) and concomitantly with the upregulation of DR5 expression. The role of RKIP induction by rituximab in the upregulation of DR5 and sensitization to TRAIL apoptosis was corroborated by the use of cells over expressing RKIP which were sensitive to TRAIL apoptosis in the absence of rituximab. Our findings reveal a novel mechanism of rituximab-induced sensitization of B-NHL to TRAIL apoptosis via inhibition of NF-kB and Snail and upregulation of RKIP and DR-5. The combination of rituximab and TRAIL may be effective in the treatment of B-NHL. Further, our studies suggest that agents other than rituximab that can induce RKIP can reverse resistance to TRAIL in B-NHL that are unresponsive to rituximab treatment.
DNA Repair Gene, XRCC1 Polymorphisms Are Associated with Chemotherapy Induced Toxicity in Patients with Diffuse Large B Cell Lymphoma Who Received Frontline R-CHOP Chemotherapy.
Authors: Kim In-Suk , Lee Gyeong-Won , Kim Hoon-Gu , Kong Sun-Young , Eom HyeonSeok 
Published: April 2020

Abstract
BACKGROUND. X-ray repair cross-complementing group I (XRCC1) is a DNA repair gene. Polymorphisms in DNA repair genes may alter protein function and therefore the efficacy of DNA damaging chemotherapy. We retrospectively evaluated the association of three polymorphisms in XRCC1 codon 194 (Arg to Trp), 280 (Arg to His), and 399 (Arg to Gln), with grade 3 or 4 toxicities of primary rituximab plus cyclophosphamide/doxorubicin/vincristine/prednisone (R-CHOP) therapy in 145 patients with diffuse large B cell lymphoma (DLBCL).
METHODS. A total of 145 patients who received R-CHOP chemotherapy as a frontline regimen DLBCL were included in this retrospective study from 3 hospitals in Korea. The genotypes of XRCC1 at the Arg194Trp, Arg280His, and Arg399Gln were determined by direct sequencing methods. The clinical characteristics, treatment outcomes and grade 3 and 4 toxicities of the patients were compared using Chi-square, Fisher exact, Mann-Whitney U tests, or logistic regression according to the XRCC1 polymorphisms.
RESULTS. Carrying at least one variant XRCC1 Arg194Trp alleles (194Arg/Trp or 194Trp/Trp) and XRCC1 Arg399Gln variant alleles (399Arg/Gln or 399Gln/Gln) was associated with a significantly increased risk of grade 3 or 4 gastrointestinal toxicity (Arg194Trp alleles; odds ratio, 3.489; 95% confidence interval, 0.126–1.568; P=0.001, Arg399Gln alleles; odds ratio, 2.577; 95% confidence interval, 0.144–1.096; P=0.011, respectively). The carriers of XRCC1 Arg280His variant alleles (280Arg/His or 280His/His) was associated with grade 3 or 4 neutropenia (odds ratio, 2.047; 95% confidence interval, 0.008–0.450; P=0.043). No differences in the patient characteristics, disease characteristics, response, and survival in patients with DLBCL who received frontline R-CHOP chemotherapy were observed according to three XRCC1 polymorphims.
CONCLUSIONS. This study demonstrates that the patients carrying at least one variant XRCC1 Arg194Trp or XRCC1 Arg399Gln alleles have a 2.5-to 3.5-fold increased risk of grade 3 or 4 gastrointestinal toxicity and the patients carrying at least one variant XRCC1 Arg280His allele have a 2.0-fold increased risk of grade 3 or 4 neutropenia when treated with frontline R-CHOP chemotherapy and this has implications for optimizing treatment with such agents.
Bortezomib Overcomes Cell Adhesion-Mediated Drug Resistance Via Down-Regulation of VLA-4 Expression in Multiple Myeloma.
Authors: Hatano Kaoru , Kikuchi Jiro , Takatoku Masaaki , Shimizu Rumi , Wada Taeko , Ueda Masuzu , Nobuyoshi Masaharu , Oh Iekuni , Sato Kazuya , Suzuki Takahiro , Ozaki Katsutoshi , Mori Masaki , Nagai Tadashi , Muroi Kazuo , Kano Yasuhiko , Furukawa Yusuke , Ozawa Keiya 
Published: April 2020

Abstract
Multiple myeloma (MM) is incurable, mainly because of cell adhesion-mediated drug resistance (CAM-DR). In this study, we performed functional screening using shRNA to define the molecule(s) responsible for CAM-DR of MM. Using 4 bona fide myeloma cell lines (KHM-1B, KMS12-BM, RPMI8226, and U266) and primary myeloma cells, we identified CD29 (b1-integrin), CD44, CD49d (a4-integrin, a subunit of VLA-4), CD54 (ICAM-1), CD138 (syndecan-1) and CD184 (CXCR4) as major adhesion molecules expressed on MM. Short hairpin RNA-mediated knockdown of CD49d but not CD44, CD54, CD138, and CD184 significantly reversed CAM-DR of myeloma cells to bortezomib, vincristine, doxorubicin, and dexamethasone. Experiments using blocking antibodies yielded almost identical results. Bortezomib was relatively resistant to CAM-DR because of its ability to specifically down-regulate CD49d expression. This property was unique to bortezomib and was not observed in other anti-myeloma drugs. Pretreatment with bortezomib was able to ameliorate CAM-DR of myeloma cells to vincristine and dexamethasone. These results suggest that VLA-4 plays a critical role in CAM-DR of MM cells. The combination of bortezomib with conventional anti-myeloma drugs may be effective in overcoming CAM-DR of MM.
Obesity Alters the Pharmacokinetics of Vincristine in Mice.
Authors: Behan James W , Avramis Vassilios I , Yun Jason P , Butturini Anna , Mittelman Steven D 
Published: April 2020

Abstract
Obesity has been associated with increased risk of development and poor outcome from a variety of hematological malignancies. There is a lack of consensus as to how to dose chemotherapies in obese patients, and therefore inadequate dosing represents a potential factor contributing to poor outcome. We have previously shown that diet-induced obese mice transplanted with p190BCR/ABL ALL cells and then treated with vincristine (VCR) proportional to body weight (15 mg/kg/wk × 4 wks) have a poorer outcome than non-obese mice (event free survival: Obese = 0.42, Control = 0.75, p=0.07, log rank). The present study was designed to quantify the pharmacokinetic (PK) parameters of vincristine in control and obese mice and determine whether differences in these parameters could explain the poorer outcome in the obese mice. Twenty obese and 20 control mice received tail-vein injections of tritiated vincristine (specific activity 75 mCi/mg; dose 0.5 mg/kg). Blood samples were taken at 5 minutes, and the mice sacrificed at various time-points between 15 minutes and 24 hours post-injection. Whole blood and tissue specimens were solubilized, decolorized, and read on a scintillation counter. Blood vincristine concentrations were fit to a 3-compartment model using the two-stage PK in 3 subsets of VCR concentrations vs. time method. Non-compartmental modeling was used to confirm the results. Due to body weight differences, obese mice received ~ 28% more vincristine per injection than controls. Blood vincristine concentrations in both groups of animals followed a triexponential decay, as has been previously described. Blood levels tended to be higher (by 20±15%) in the obese mice at all time-points tested. While the t1/2α was longer in the obese mice (10.6 vs. 6.0 minutes), the t1/2b and t1/2γ were both shorter (22.7 vs. 27.1 minutes and 114.4 vs. 345.8 hours). Therefore the AUC0 → 24 was higher in the obese mice (3,279 vs. 2,776 ng/ml*hr), while the AUC0 → ∞ was lower in the obese mice (21,705 vs. 53,581 ng/ml*hr). Vincristine concentrations in spleen and bone marrow were similar at all time-points in the obese and control groups. In summary, obesity caused alterations in vincristine pharmacokinetics, characterized by longer initial half-life but shorter terminal half-lives. Thus, it is possible that the decreased AUC0 → ∞ contributed to the poorer outcome in this model. Despite this, blood and tissue concentrations of vincristine were equal or higher in the obese mice during the first 24 hours after injection of the drug when it was dosed proportional to body weight. These data suggest that dosing vincristine in obese patients based on body surface may lead to lower levels in blood and tissue, particularly if the dose is capped. As the prevalence of obesity continues to increase, pharmacokinetics studies should be performed in obese and lean subjects to further optimize chemotherapy dosing regimens in obese patients.