A Role for TNF-α in Chronic Lymphocytic Leukemia Bone Marrow Hematopoietic Dysfunction

The current paradigms of known peripheral immune abnormalities in B-Chronic Lymphocytic Leukemia (CLL) are not able to consistently explain patient complications and it is difficult to correct a given CLL patient's immune status. Here, we expand on our initial report demonstrating bone marrow (BM) hematopoietic dysfunction in untreated CLL patients (Manso et al., Leukemia volume 33, pages 638-652, 2019). CLL patient BM had significantly reduced frequencies and short-term functional capacity of hematopoietic stem and progenitor cells (HSPCs). Additionally, the remaining progenitors exhibited increased protein levels of the key hematopoietic transcriptional regulators GATA-2 and PU.1. We further evaluated the frequency and function of myeloid stem cells from controls and untreated CLL patients by limiting dilution analysis in long-term culture-initiating cell (LTC-IC) assays. Over the 5 week duration of the assay, we observed delayed and partial recovery of myelopoiesis from CLL-derived HSPCs (Figure 1A). These data suggest that removal of HSPCs from the CLL leukemic microenvironment partially recovers their ability to sustain myelopoiesis. A known inflammatory mediator and hematopoiesis-modulating cytokine that is constitutively produced by CLL cells, TNF-α, induced increased expression of GATA-2 and PU.1 in specific HSPC subsets and reduced formation of short-term colony forming units in vitro. Addition of TNF-α to LTC-IC assays resulted in a striking ablation of myelopoiesis in a dose-dependent manner, partially reproducing the ex vivo results (Figure 1B). To further assess the direct impact of CLL cells on HSPC biology, isolated HSPCs from controls were exposed in vitro to leukemic CLL cells. The co-culture induced overexpression of GATA-2 and PU.1 in distinct HSPC populations, recapitulating our ex vivo findings (Figure 1C-D). When cell-cell contact was inhibited by use of Transwell inserts, an intermediate increase in GATA-2 and PU.1 was observed, highlighting the contributions of both soluble mediators and cell-cell contact to HSPC alterations. In both direct and Transwell co-culture conditions, overexpression of GATA-2 and PU.1 was reversed when TNF-α was neutralized (Figure 1E-F). Taken together, these findings indicate a significant role for CLL-derived TNF-α in HSPC modulation and expand our previous observations of BM dysfunction in untreated CLL patients. This data offers new molecular insight into the contribution of the leukemic microenvironment to altered hematopoiesis, contributing to immunodeficiency in CLL, and identifies TNF-α as a potential therapeutic target for correction of hematopoiesis in CLL disease. Disclosures Ding: Merck: Research Funding; DTRM Biopharma: Research Funding. Parikh:AstraZeneca: Honoraria, Research Funding; MorphoSys: Research Funding; AbbVie: Honoraria, Research Funding; Acerta Pharma: Research Funding; Pharmacyclics: Honoraria, Research Funding; Janssen: Research Funding; Ascentage Pharma: Research Funding; Genentech: Honoraria. Novak:Celgene Coorperation: Research Funding. Kay:Agios: Other: DSMB; Celgene: Other: Data Safety Monitoring Board; Infinity Pharmaceuticals: Other: DSMB; MorphoSys: Other: Data Safety Monitoring Board.

Download Full-text

Chronic Lymphocytic Leukemia Cells With Trisomy 12 Home To The Bone Marrow In a CXCR4-Independent Manner and Are Prone To Proliferate In Vitro

Blood ◽

10.1182/blood.v122.21.870.870 ◽

2013 ◽

Vol 122 (21) ◽

pp. 870-870

Author(s):

Evelyn Hutterer ◽

Elisabeth Hinterseer ◽

Sylvia Ganghammer ◽

Gabriele Brachtl ◽

Daniela Asslaber ◽

...

Keyword(s):

Bone Marrow ◽

Chronic Lymphocytic Leukemia ◽

Research Funding ◽

Lymphocytic Leukemia ◽

Dependent Manner ◽

Independent Manner ◽

Atypical Cell ◽

Trisomy 12 ◽

Inside Out

Abstract Trisomy 12 (tri12) is a frequent chromosomal aberration in chronic lymphocytic leukemia (CLL) associated with atypical cell morphology, high in vivo tumor proliferation activity and a predisposition to Richter’s transformation. Tri12 harboring CLL cells express increased levels of the negative prognostic marker CD49d, the α4 subunit of the integrin very late antigen 4 (VLA-4), which we previously identified as a key regulator of CLL cell homing to bone marrow (BM). During this process, inside-out activation of VLA-4 upon CXCR4 binding to endothelially displayed CXCL12 is thought to upregulate the adhesive properties of VLA-4 and augment the arrest of CLL cells on the VCAM-1 presenting vessels. Here, we investigated the functional interplay of VLA-4 and CXCR4 in CLL carrying tri12. We first found that the upregulation of CD49d expression in this subset (MFIR CD49d 9.8±5.3 (n=22) vs. 2.7±3.9 (n=126), p<0.0001) was paralleled by their reduced CXCR4 expression (MFIR CXCR4 11.8±7.2 (n=22) vs. 22.7±14.2 (n=126), p=0.0003). Using short term adoptive transfers, we compared the ability of tri12 and no tri12 CLL cells to home to the BM of NOD/SCID mice. 5-10x106 CLL cells were injected into tail vein and homing was evaluated after 3 hours. Based on their more frequent CD49d high phenotype, we observed increased homing rates (homed human CLL cells per 106 injected cells per 106 acquired murine cells) of tri12 compared to no tri12 CLL (225±160 (n=7) vs. 90±117 (n=20), p=0.025). However, when comparing CD49d+ tri12 and CD49d+ no tri12 subsets, we did not observe any significant differences in their homing capacity. To further study CXCL12/CXCR4 function in BM homing, we pretreated mice with either the novel CXCL12 antagonist NOX-A12 or the CXCR4 inhibitor AMD3100 prior to CLL cell injection. While homing of no tri12 CLL cells (n=3, in duplicates) was reduced by both pretreatments (homing rates 137 vs 38 vs 30), the homing capacity of tri12 CLL cells (n=3, in duplicates) was not affected. We next tested whether VLA-4 expressed on these cells was able to undergo CXCL12-induced activation and support cell arrest under shear conditions. To this end, we perfused CLL cells over VCAM-1 or VCAM-1/CXCL12 substrates and analyzed rates and categories of cell tethering at a single cell level by videomicroscopy. CXCL12 induced the arrests of no tri12 CLL cells (n=3) on VCAM-1 under shear flow in a CXCR4 and VLA-4 dependent manner. In contrast, tri12 CLL cells (n=3) robustly tethered to VCAM-1 in the absence of the chemokine, and interactions could not be further enhanced by additional CXCL12 nor could they be abrogated by use of AMD3100. This failure of CXCR4-induced adhesion was not based on a general defect in CXCR4 functionality as in vitro chemotaxis of tri12 CLL cells (n=5) towards CXCL12 was fully maintained. To detect potential differences in VLA-4 affinity regulation, we used a conformationally sensitive antibody that recognizes epitopes induced by VLA-4 ligation, and an LDV-containing VLA-4 specific ligand to probe resting integrin affinity. Also, we used a small fluorescent ligand to study rapid VLA-4 affinity changes during inside-out chemokine induced activation. On resting tri12 CLL, VLA-4 exhibited an affinity state similar to that observed on circulating lymphocytes, and tri12 CLL cells failed to undergo the rapid affinity up-regulation triggered by CXCL12 pretreatment, in keeping with tethering experiments. Next, we investigated whether the tumor microenvironment has a different influence on the behavior of the tri12 subset. Therefore we subjected the cells to in vitro co-cultures mimicking the lymphoid proliferation centers. Basal levels of the early activation marker CD69 were similar in tri12 CLL compared to no tri12 cases. Tri12 CLL, however, underwent stronger activation when cultured in presence of accessory cells (%CD69+ cells 60.0±18.5 (n=4) vs. 17.7±20.1 (n=19), p=0.008). Moreover, in several setups, proliferation rates of these cells were increased, irrespective of the proliferative stimulus and detection method used. In summary, our results provide a mechanistical basis at least in part explaining the peculiar and clinical features of the tri12 CLL subset. In light of the specific migratory and proliferative properties of tri12 cells and novel agents targeting particularly these functions, our findings may also imply therapeutical consequences. Disclosures: Greil: NOXXON Pharma AG: Research Funding. Hartmann:NOXXON Pharma AG: Research Funding.

Download Full-text

Development of a Human Therapeutic L-Cyst(e)Ine-Degrading Enzyme for the Treatment of Hematological Malignancies

Blood ◽

10.1182/blood.v128.22.1587.1587 ◽

2016 ◽

Vol 128 (22) ◽

pp. 1587-1587

Author(s):

Giulia Agnello ◽

Susan Alters ◽

Joseph Tyler ◽

Jinyun Liu ◽

Peng Huang ◽

...

Keyword(s):

Research Funding ◽

Hematological Malignancies ◽

Ex Vivo ◽

Redox Balance ◽

Lymphocytic Leukemia ◽

Employment Equity ◽

Equity Ownership ◽

Antioxidant Mechanisms

Abstract Cancer cells experience higher intrinsic oxidative stress than their normal counterparts and acquire adaptive antioxidant mechanisms to maintain redox balance. This increased antioxidant capacity has been correlated to malignant transformation, metastasis and resistance to standard anticancer drugs. This enhanced antioxidant state also correlates with cancer cells being more vulnerable to additional oxidative insults, therefore disruption of adaptive antioxidant mechanisms may have significant therapeutic implications. Hematological malignancies including Chronic Lymphocytic Leukemia (CLL), Acute Lymphocytic Leukemia (ALL), Acute Myeloid Leukemia (AML) and Multiple Myeloma (MM) are critically dependent on the cellular antioxidant glutathione (GSH), consistent with the higher intrinsic oxidative stress. L-cysteine is the rate-limiting substrate for GSH biosynthesis and adequate levels of cysteine are critical to maintain the intracellular homeostasis of GSH. CLL and a subset of ALL cells have been reported to rely on the stromal supply of cysteine to increase the synthesis of GSH in order to maintain redox balance, which in turn promotes cell survival and fosters drug resistance. One approach to target this cancer specific dependency is by therapeutic depletion of amino acids via enzyme administration; a clinically validated strategy for the treatment of ALL. Aeglea BioTherapeutics Inc. has developed a bioengineered cysteine and cystine degrading enzyme (Cyst(e)inase, AEB3103) and evaluated its therapeutic efficacy against hematological malignancies in in vitro, ex vivo and in vivo pre-clinical studies. The TCL1-TG:p53 -/- mouse model exhibits a drug resistant phenotype resembling human CLL with unfavorable cytogenetic alterations and highly aggressive disease progression. AEB3103 greatly decreased the viability of TCL1-TG:p53 -/- cells cultured in vitro, whereas the CLL therapeutic, fludarabine, showed minimal cytotoxic effects. In vivo treatment of TCL1-TG:p53 -/- mice with AEB3103 resulted in an increase in median survival time (7 months, p<0.0001) compared to the untreated control group (3.5 months, p<0.001) and a fludarabine treated group (5.3 months, p<0.001). These results indicate a superior therapeutic effect of AEB3103 compared to fludarabine. Additionally, evaluation of AEB3103 in in vitro 2D cultures of patient-derived CLL and MM cells, and in ex vivo 3D cultures of cells derived from ALL and AML PDx models resulted in significant cell growth inhibition with therapeutically relevant IC50 values. Collectively these results demonstrate the sensitivity of hematological malignancies to modulation of GSH levels via AEB3103-mediated cyst(e)ine depletion. Disclosures Agnello: Aeglea BioTherapeutics: Employment. Alters:Aeglea BioTherapeutics: Employment, Equity Ownership. Tyler:Aeglea BioTherapeutics: Employment, Equity Ownership. Huang:Aeglea BioTherapeutics: Research Funding. Stone:Aeglea Biotherapeutics: Consultancy, Equity Ownership, Research Funding; University of Texas at Austin: Employment, Patents & Royalties: I am an inventor of technology related to this abstract. Georgiou:Aeglea Biotherapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding. Lowe:Aeglea BioTherapeutics: Employment, Equity Ownership. Rowlinson:Aeglea BioTherapeutics: Employment, Equity Ownership.

Download Full-text

Successful Salvage Therapy By Idelalisib Followed By Haploidentical Allogenic Transplantation of an Alemtuzumab-Refractory T-Cell Prolymphocytic Leukemia

Blood ◽

10.1182/blood.v126.23.5071.5071 ◽

2015 ◽

Vol 126 (23) ◽

pp. 5071-5071

Author(s):

Julien Lenglet ◽

Amélie Trinquand ◽

Ludovic Lhermitte ◽

Ali Bazarbachi ◽

Laurent Frenzel ◽

...

Keyword(s):

Bone Marrow ◽

T Cell ◽

Complete Remission ◽

Research Funding ◽

Ex Vivo ◽

Prolymphocytic Leukemia ◽

Circulating Lymphocytes ◽

Genetic Events ◽

Support Research

Abstract Background T-cell prolymphocytic leukemia (T-PLL) is a rare disease of extremely poor outcome. The current standard of care involves intravenous Alemtuzumab with high response rates. Virtually all patients experience relapse and the 5-years overall survival is not higher than 5%. Allogenic bone marrow transplantation is the only curative option. Case presentation A 35 years-old male was diagnosed with T-PLL in early 2014 with skin infiltration, fatigue, hepatomegaly, splenomegaly (28 cm), and lymphadenopathies. Immunophenotypic features of circulating lymphocytes showed a T-cell lymphoproliferation (CD2+ CD3+ CD5+ CD7+ CD8+). TCL1 hyperexpression was assessed on bone marrow and lymph node biopsy samples. There was a rearrangement of chromosome 14 involving TCL1 on circulating cells. Pentostatin was initiated for 2 cycles without success. IV alemtuzumab (30mg/m2) was then introduced. After 8 weekly cycles, a CT scan showed a reduction of the splenomegaly (22 cm), a stable hepatomegaly, and no remaining lymphadenopathy. No abnormal circulating lymphocytes were detectable. After 14 cycles, the patient showed cervical painful lymph nodes. A needle aspiration revealed relapse with T-PLL cells. We then introduced idelalisib (150 mg, twice daily). Alemtuzumab was discontinued. One week after the introduction of idelalisib, physical examination revealed the disappearance of all peripheral lymph nodes. After 2 weeks, the spleen size was reduced to 16 cm and a body PET-CT was negative, proving metabolic remission. No circulating lymphocyte could be found. The patient was considered as being in complete remission (CR) and underwent haplo-identical transplantation. Idelalisib was discontinued after three weeks of exposure before transplantation and reintroduced from days 30 to 60. At day 100 after transplantation, the patient was in persistent CR: a peripheral immunophenotypic study was performed, no clonal T population was found, chimerism was 100% of donor origin. A bone marrow aspirate was quantitatively and qualitatively normal. Seven months after transplant, the patient remains in CR with a grade 1 skin chronic GVHD. Biological rationale Idealisib is a delta isoform inhibitor of protein phosphatidylinositol 3 kinase (PI3K). TCL1 is an overexpressed oncoprotein described in the majority of T-PLL due to chromosomal 14 rearrangement. TCL1 modulates AKT activity, facilitating both AKT dimerization and phosphorylation upon PI3K stimulation. The PI3K produces PIP2 and PIP3, which are required to phosphorylate AKT. Even if TCL1 is not sufficient to transform T cells into T-PLL cells and requires secondary genetic events as suggested in murine models, AKT hyperactivation may participate in T-cell proliferation (through the GSK-3β and mTOR pathways), and survival (through the NFκB pathway). We hypothesized that the inhibition of the PI3K with idelalisib would inhibit growth and eventually cell survival of the T-PLL cell, depending on the secondary genetic events. In order to support this hypothesis, we investigated the biochemical and functional effects of idelalisib in vitro. Fresh primary T-PLL cells were obtained from the ascites of an another case of T-PLL (CD2+, CD3+, CD5+, CD7+, CD4/CD8+, complex caryotype involving chromosome 14). In vitro exposure of primary T-PLL cells to idelalisib led to a dramatic and dose-dependent decrease in AKT phosphorylation after 24 hours (figure 1) and ex vivo after 5 days (figure 2). However, no apoptotic response was observed, neither in vitro nor ex vivo, even though therapeutic levels of idelalisib were reached in the ascites. Conclusion We report the first case of idealisib successfully used as a salvage therapy in T-PLL, leading to complete remission. It was used as a bridge to transplantation for a patient who is still in complete remission 7 months after transplantation. Our results provide a paradigm for the use of a PI3K inhibitor in T-PLL, which results in AKT dephosphorylation. The lack of functional response for the second patient suggests that the clinical response may depend on other oncogenic events, which could bypass AKT dependency. There is a need to identify a patient subgroup that may benefit from PI3K inhibition. In an attempt to identify molecular mechanisms underlying this resistance, comparative full exome sequencing is being performed for both patients and will be shown at the meeting. Disclosures Off Label Use: idelalisib, PI3-Kinase inhibitor. Tournilhac:Roche: Other: Travel support, Research Funding; Celgene: Other: Travel support; Mundiphrama: Honoraria, Other: Travel Support, Research Funding; GSK: Other: Travel Support, Research Funding; Janssen Cilag: Honoraria, Other: Travel support; Gilead: Other: Travel Funding.

Download Full-text

Bone Marrow Hematopoietic Dysfunction in Untreated Chronic Lymphocytic Leukemia Is Partially Mediated By Exposure to Constituents of the Leukemic Microenvironment

Blood ◽

10.1182/blood-2018-99-118916 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 3132-3132

Author(s):

Bryce Manso ◽

Kimberly Gwin ◽

Charla R Secreto ◽

Henan Zhang ◽

Wei Ding ◽

...

Keyword(s):

Bone Marrow ◽

B Cells ◽

Chronic Lymphocytic Leukemia ◽

Board Of Directors ◽

Research Funding ◽

Lymphocytic Leukemia ◽

Healthy Controls ◽

Advisory Committees ◽

The Impact

Abstract Peripheral immune dysfunction in B-Chronic Lymphocytic Leukemia (CLL) is well-studied and likely relates to the incidence of serious recurrent infections and second malignancies that plague CLL patients. However, the current paradigms of known immune abnormalities are not able to consistently explain these complications and it is not easy to correct CLL patient immune status. Here, we expand on our preliminary reports that demonstrate bone marrow (BM) hematopoietic dysfunction in early and late stage untreated CLL patients. We found reduced short-term functional capacity of hematopoietic progenitors in BM using colony forming unit assays (Figure 1A-C) and flow cytometry revealed significant reductions in frequencies of hematopoietic stem and progenitor cell (HSPC) populations (exemplified by Lin-CD34+ HSPCs, Figure 1D). We further report that protein levels of the transcriptional regulators HIF-1α, GATA-1, PU.1, and GATA-2 are overexpressed in distinct HSPC subsets from CLL patient BM, providing molecular insight into the basis of HSPC dysfunction. Interestingly, sustained myelopoiesis, evaluated by limiting dilution analysis in long-term culture-initiating cell (LTC-IC) assays maintained for five weeks, revealed no difference between healthy controls and CLL patients. These new data indicate that when HSPCs are removed from the leukemic microenvironment for ample in vitro culture time, they recover the ability to sustain myelopoiesis. To further assess the impact of the CLL microenvironment on HSPC biology, isolated HSPCs (CD34+ BM cells) from healthy controls were exposed in vitro to known leukemic microenvironment constituents. Exposure to TNFα, a cytokine constitutively produced by CLL B cells, resulted in rapid increases in PU.1 and GATA-2 proteins (Figure 2A-D). Similarly, addition of TNFα to the LTC-IC assay resulted in a striking ablation of myelopoiesis, even at the highest input cell concentration. Further, overexpression of PU.1 and GATA-2 were observed in HSPCs following co-culture with CLL B cells, a result that was not recapitulated when cells were exposed to IL-10, another cytokine constitutively produced by CLL B cells. These findings indicate specific components of the leukemic microenvironment are involved in HSPC modulation. Together, these findings expand on our previous observations of BM hematopoietic dysfunction in untreated CLL patients and offer new molecular insights into the contribution of the leukemic microenvironment on immunodeficiency in CLL. Disclosures Ding: Merck: Research Funding. Parikh:Pharmacyclics: Honoraria, Research Funding; MorphoSys: Research Funding; Janssen: Research Funding; Abbvie: Honoraria, Research Funding; Gilead: Honoraria; AstraZeneca: Honoraria, Research Funding. Kay:Morpho-sys: Membership on an entity's Board of Directors or advisory committees; Agios Pharm: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Acerta: Research Funding; Infinity Pharm: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Tolero Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Cytomx Therapeutics: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Download Full-text

Circulating Extracellular Vesicles Induce Chimeric Antigen Receptor T Cell Dysfunction in Chronic Lymphocytic Leukemia (CLL)

Blood ◽

10.1182/blood-2019-125272 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 679-679

Author(s):

Michelle J. Cox ◽

Fabrice Lucien-Matteoni ◽

Reona Sakemura ◽

Justin C. Boysen ◽

Yohan Kim ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cell Line ◽

Research Funding ◽

Cell Lymphoma ◽

Ex Vivo ◽

Data Safety Monitoring Board ◽

Lymphocytic Leukemia ◽

Cell Dysfunction

Treatment with CD19-directed chimeric antigen receptor T cell (CART19) therapy has resulted in unprecedented clinical outcomes and was FDA-approved in acute lymphoblastic leukemia and non-Hodgkin B-cell lymphoma. However, its success in chronic lymphocytic leukemia (CLL) has been modest to date. An increasing body of evidence indicates that impaired CART cell fitness is the predominant mechanism of the relative dysfunction in CLL. The immunosuppressive microenvironment in CLL is well known and in part may be related to the abundance of circulating extracellular vesicles (EVs) bearing immunomodulatory properties. We hypothesized that CLL-derived EVs contribute to CART cell dysfunction. In this study, we aimed to investigate the interaction between circulating EVs isolated from CLL patient plasma (designated as CLL-derived EVs) and CART19 cells. We enumerated and immunophenotyped circulating EVs from platelet free plasma in untreated patients with CLL. We determined their interaction with CART19 cells using second generation, 41BB co-stimulated, lentiviral transduced CART19 cells generated in the laboratory from normal donors (FMC63-41BBζ CART cells). Our findings indicate that CLL-derived EVs impair normal donor CART19 antigen-specific proliferation against the CD19+ mantle cell lymphoma cell line Jeko-1 (Figure 1A). Next, we characterized CLL-derived EVs using nanoscale flow cytometric analysis of surface proteins and compared to healthy controls. Although the total EV particle count was not different between CLL and healthy controls (Figure 1B), there were significantly higher PD-L1+ EVs in patients with CLL (Figure 1C). Based on these results, we sought to assess the physical interaction between CLL-derived EVs and CART cells from normal individuals. When CLL-derived EVs were co-cultured with CART19 and CLL B cells and imaged with super-resolution microscopy, EVs were localized at the T cell-tumor junction (Figure 1D). Furthermore, CLL-derived EVs are captured by T cells as indicated by a significant reduction in the absolute count of EVs when co-cultured with resting T cells (Figure 1E). Having demonstrated that 1) there is an excess of PD-L1+ EVs in patients with CLL (Figure 1C) and 2) CLL-derived EVs physically interact with CART cells (Figures 1D-E), we sought to establish their functional impact on CART19 cells. Here, CART19 cells were stimulated with irradiated CD19+ JeKo-1 cells at a 1:1 ratio in the presence of increasing concentrations of CLL-derived EVs. There was a significant upregulation of inhibitory receptors such as PD-1 and CTLA-4 on the T cells (Figure 1F). This is associated with a reduction in CART effector cytokines (i.e., TNFβ) at higher concentrations of EVs (Figure 1G), suggesting a state of exhaustion in activated CART19 cells in the presence of CLL-derived EVs. This was further supported by transcriptome interrogation of CART19 cells. Here, CART19 cells were stimulated via 24-hour co-culture with the irradiated CD19+ cell line JeKo-1, in the presence of CLL-derived EVs at ratios of 10:1 and 1:1 EV:CART19 and then isolated by magnetic sorting. RNA sequencing of these activated CART19 cells indicated a significant upregulation of AP-1 (FOS-JUN) and YY1 (Figures 1H), known critical pathways in inducing T cell exhaustion. Finally, to confirm the impact of CLL-derived EVs on CART19 functions in vivo, we used our xenograft model for relapsed mantle cell lymphoma. Here, immunocompromised NOD-SCID-ɣ-/- mice were engrafted with the CD19+ luciferase+ cell line JeKo-1 (1x106 cells I.V. via tail vein injection). Engraftment was confirmed through bioluminescent imaging and mice were randomized to treatment with 1) untreated, 2) CART19 cells, or 3) CART19 cells co-cultured ex vivo with CLL-derived EVs for six hours prior to injection. A single low dose of CAR19 (2.5x105) was injected, to induce relapse. Treatment with CART19 cells that were co-cultured ex vivo with CLL-derived EVs resulted in reduced anti-tumor activity compared to treatment with CART19 alone (Figure 1I). Our results indicate that CLL-derived EVs induce significant CART19 cell dysfunction in vitro and in vivo, through a direct interaction with CART cells resulting in a downstream alteration of their exhaustion pathways. These studies illuminate a novel way through which circulating and potentially systemic EVs can lead to CART cell dysfunction in CLL patients. Disclosures Cox: Humanigen: Patents & Royalties. Sakemura:Humanigen: Patents & Royalties. Parikh:Ascentage Pharma: Research Funding; Janssen: Research Funding; AstraZeneca: Honoraria, Research Funding; Genentech: Honoraria; Pharmacyclics: Honoraria, Research Funding; MorphoSys: Research Funding; AbbVie: Honoraria, Research Funding; Acerta Pharma: Research Funding. Kay:Agios: Other: DSMB; Celgene: Other: Data Safety Monitoring Board; Infinity Pharmaceuticals: Other: DSMB; MorphoSys: Other: Data Safety Monitoring Board. Kenderian:Humanigen: Other: Scientific advisory board , Patents & Royalties, Research Funding; Lentigen: Research Funding; Novartis: Patents & Royalties, Research Funding; Tolero: Research Funding; Morphosys: Research Funding; Kite/Gilead: Research Funding.

Download Full-text

TBK1/Ikkε Inhibitor Amlx Blocks Multiple Myeloma Cell Growth in Vitro and In Vivo

Blood ◽

10.1182/blood-2018-99-119677 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 4504-4504

Author(s):

Quanhong Sun ◽

Peng Zhang ◽

Juraj Adamik ◽

Konstantinos Lontos ◽

Valentina Marchica ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Tumor Growth ◽

Cell Lines ◽

Bone Disease ◽

Research Funding ◽

Ex Vivo ◽

Dominant Negative ◽

Induction Of Apoptosis

Abstract Multiple myeloma (MM) is the most frequent cancer to involve the skeleton and remains incurable for most patients, thus novel therapies are needed. MM bone disease is characterized by osteolytic lesions that contribute significantly to patient morbidity and mortality. We showed that TBK1 signaling is a novel pathway that increases osteoclast (OCL) formation in Paget's disease, an inflammatory bone disease. Therefore, we hypothesized that TBK1 plays a similar role in MM induction of OCL. We found that MM conditioned media (MM-CM) dose-dependently increased bone marrow monocyte (BMM) expression of activated TBK1 protein and enhanced RANKL-driven OCL formation. TBK1 knockdown by shRNA transduction into BMM significantly attenuated the ability of MM-CM to increase OCL differentiation without altering OCL differentiation in control media. We found that the TBK1/IKKε inhibitor Amlexanox (Amlx) blocked normal and MM-enhanced OCL formation. Importantly, TBK1 mRNA expression in CD138+ plasma cells (PC) isolated from MM or PC leukemia patients is significantly higher as compared to PC from Monoclonal Gammopathy of Undetermined Significance (MGUS) patients. Therefore, we tested whether targeting the TBK1/ IKKε signaling pathways would also affect MM cells. We found that Amlx strongly decreased the viability of several MM cell lines and primary MM cells via induction of apoptosis. Amlx treatment of MM cell lines also induced a G1/S blockade, decreased activated ERK1/2, and increased translation of the dominant-negative C/EBPb-LIP isoform in several MM cell lines. The positive-acting C/EBPb-LAP isoform was previously shown to be a critical transcription factor for MM viability. Importantly, Amlx also enhanced the effectiveness of the proteasome inhibitors bortezomib and carfilzomib to kill MM cells in culture. Further, Amlx sensitized MM1.S cells to the induction of apoptosis by the autophagic inhibitor Bafilomycin A. Amlx dose-dependently inhibited tumor growth in a syngeneic MM mouse model in which 5TGM1 MM cells expressing secreted GLuc were injected subcutaneously into immunocompetent C57Bl/KaLwRij. Tumor growth was assessed by measuring tumor volumes and by the levels of secreted GLuc in the blood. Further, OCL formation ex vivo from bone marrow monocytes obtained from AMLX-treated mice versus controls was decreased. Amlx did not affect the viability of primary BMM, bone marrow stromal cells (BMSC), or splenocytes. Further, Amlx treatment of primary BMSC from MM patients or normal donors decreased expression of TNFα, IL-6 and RANKL, thereby decreasing BMSC support of MM survival and OCL differentiation. Amlx pretreatment of BMSC and murine pre-osteoblast MC4 cells also decreased VCAM1 expression and reduced MM cell adhesion, another mechanism for Amlx reduction of bone microenvironmental MM support. These data suggest that targeting TBK1/IKKε signaling may decrease MM bone disease by slowing MM growth, directly and indirectly, and preventing MM-induced osteolysis. Disclosures Giuliani: Janssen Pharmaceutica: Other: Avisory Board, Research Funding; Celgene Italy: Other: Avisory Board, Research Funding; Takeda Pharmaceutical Co: Research Funding. Roodman:Amgen Denosumab: Membership on an entity's Board of Directors or advisory committees.

Download Full-text

Towards CD38-Targeted Immunochemotherapy of Multiple Myeloma: Significant Improvement of Anti-Myeloma Effects of Lenalidomide, Bortezomib and Dexamethason by CD38-Specific Antibody Daratumumab, Even in Chemotherapy Resistant/Intolerant Patients

Blood ◽

10.1182/blood.v120.21.4988.4988 ◽

2012 ◽

Vol 120 (21) ◽

pp. 4988-4988

Author(s):

Inger S. Nijhof ◽

Jeroen Lammerts van Bueren ◽

Berris van Kessel ◽

Michel de Weers ◽

Joost M Bakker ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Research Funding ◽

Plasma Cells ◽

Ex Vivo ◽

Human Antibody ◽

Synergistic Activity ◽

Effector Cells ◽

Complement Dependent Cytotoxicity

Abstract Abstract 4988 To date, multiple myeloma (MM) remains an incurable malignancy of antibody-producing clonal plasma cells. The introduction of a new generation of immunomodulatory agents, such as lenalidomide (LEN), and the potent proteasome inhibitor bortezomib (BORT), used alone or in combination with steroids (dexamethasone; DEX or prednisone; PRED) has significantly improved the overall survival of MM patients. Nonetheless, all chemotherapy strategies are eventually hampered by the development of drug-resistance. Towards a novel and effective targeted immunotherapy for MM, we have developed daratumumab (DARA), a CD38 human antibody with broad-spectrum killing activity. In vitro, DARA induces substantial anti-MM effects mainly via ADCC (antibody dependent cellular cytotoxicity) and CDC (complement dependent cytotoxicity). In ex vivo assays, which allowed us to address killing of MM cells in bone marrow aspirates isolated from MM patients, enhanced or even synergistic MM cell killing was observed when DARA was combined with LEN, or with cocktails of LEN/BORT/DEX and melphalan/BORT/DEX. We now extended these ex vivo analyses to evaluate whether DARA in combination with LEN, BORT and DEX could improve the lysis of MM cells in bone marrow aspirates derived from 22 patients of whom 9 became refractory for LEN and 6 for LEN and BORT. DARA significantly enhanced the lysis of MM cells when combined with LEN or BORT in virtually all patients, including the LEN- and LEN/BORT-refractory patients. The combination of DARA+BORT and DARA+DEX induced additive killing, suggestive of lysis by independent mechanisms. When combined with LEN, DARA improved the lysis of MM cells in a synergistic manner in both non-refractory and LEN-refractory patients. This is suggestive of killing by at least partly complementary mechanisms. Synergistic activity of LEN and DARA was attributable to LEN-induced activation of effector cells that were involved in DARA-mediated ADCC. In addition, enhanced/synergistic direct killing of MM cells was observed. Experiments are under way to further investigate the mechanism underlying synergistic activity of DARA and LEN. In conclusion, our results provide a rationale for clinical evaluation of DARA in combination with LEN, BORT and DEX including in patients refractory to these drugs. Disclosures: van Bueren: genmab: Employment. de Weers:genmab: Employment. Bakker:genmab: Employment. Parren:genmab: Employment. Lokhorst:genmab: Consultancy, Research Funding. Mutis:genmab: Research Funding.

Download Full-text

3D-Tissue Engineered Bone Marrow (3DTEBM) Culture Retrospectively Predicts Treatment Clinical Outcomes of Multiple Myeloma Patients

Blood ◽

10.1182/blood-2018-99-118888 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 1987-1987

Author(s):

Amanda Jeske ◽

Feda Azab ◽

Pilar De La Puente ◽

Barbara Muz ◽

Justin King ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Board Of Directors ◽

Research Funding ◽

Ex Vivo ◽

In Vitro Models ◽

Advisory Committees ◽

Treatment Plans ◽

Equity Ownership

Abstract Background: Multiple Myeloma (MM) is the second most common hematological malignancy, and continues to be a fatal disease even with the development of novel therapies. Despite promising preclinical data in standard tissue culture models, most drugs fail in clinical trials and show lower efficacy in patients. This highlights the discrepancy between the current in vitro models, the pathophysiology of the disease in the patients, and the urgent need for better in vitro models for drug development and improved prediction of efficacy in patients. We have previously developed a patient-derived 3D-Tissue Engineered Bone Marrow (3DTEBM) culture model, which showed superior properties for proliferation of primary MM cells ex vivo, and better recapitulated drug resistance. The long-term goal of this study is to use the 3DTEBM model as a tool to perform drug screens on BM aspirates of MM patients and prospectively predict the efficacy of different therapies in individual patients, and help treatment providers develop personalized treatment plans for each individual patient. In the current study, we used the 3DTEBM model to, retrospectively, predict clinical responses of MM patients to therapy, as a proof of concept. Methods: We used whole-BM, viably frozen tissue banked samples from 20 MM patients with clear clinical response patterns of complete remission, and either very good partial response (sensitive) or progressive disease (non-sensitive). The BM aspirates were used to develop a 3DTEBM that represents each individual patient. The patient-derived 3DTEBM cultures were treated ex vivo with the same therapeutic regimen that the patient received in the clinic for 3 days. The treatment ex vivo was based on combinations at different concentrations which mimic the steady state concentrations (Css) of each drug. The efficacy of the treatment ex vivo was evaluated by digestion of the 3DTEBM matrix, extraction of the cells, and analysis for prevalence of MM cells in the treatment groups compared to the non-treated controls. Patients were defined "sensitive" if the effect reached 50% killing in the range of 10xCss. The ex vivo sensitivity data was then correlated with the clinical response outcomes. Results: We found that the 3DTEBM was predictive in approximately 80% of the cases (in about 85% of the combination therapy cases, and in about 70% of the single therapy cases). Broken down by individual drug, it was predictive in 80% of the cases treated with Bortezomib, 78% Lenalidomide, 84% Dexamethasone, 100% Daratumumab, 50% Carfilzomib, 50% Pomalidomide, and 100% Doxorubicin. Conclusions: The 3DTEBM is a more pathophysiologically relevant model which predicts clinical efficacy of drugs in multiple myeloma patients, retrospectively. This data provides the bases for future studies which will examine the ability of the 3DTEBM model to predict treatment efficacy, prospectively, for development of personalized treatment plans in individual multiple myeloma patients. Disclosures Jeske: Cellatrix LLC: Employment. Azab:Cellatrix LLC: Employment. De La Puente:Cellatrix LLC: Other: Co-founder. Vij:Jazz Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharma: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Jansson: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Azab:Ach Oncology: Research Funding; Cellatrix LLC: Equity Ownership, Other: Founder and owner; Glycomimetics: Research Funding; Targeted Therapeutics LLC: Equity Ownership, Other: Founder and owner.

Download Full-text

L-Stereoisomer RNA Oligonucleotide Anti-SDF-1 (Nox-A12) Disrupts the Interaction of Multiple Myeloma Cells with the Bone Marrow Milieu In Vivo, Leading to Enhanced Sensitivity to Bortezomib

Blood ◽

10.1182/blood.v118.21.887.887 ◽

2011 ◽

Vol 118 (21) ◽

pp. 887-887

Author(s):

Aldo M Roccaro ◽

Antonio Sacco ◽

Phong Quang ◽

AbdelKareem Azab ◽

Patricia Maiso ◽

...

Keyword(s):

Bone Marrow ◽

Confocal Microscopy ◽

Board Of Directors ◽

Tumor Cells ◽

Research Funding ◽

Ex Vivo ◽

In Vivo Confocal Microscopy ◽

Advisory Committees

Abstract Abstract 887 Background. Stomal-cell-derived factor 1 (SDF-1) is known to be involved in bone marrow (BM) engrafment for malignant tumor cells, including CXCR4 expressing multiple myeloma (MM) cells. We hypothesized that de-adhesion of MM cells from the surrounding BM milieu through SDF-1 inhibition will enhance MM sensitivity to therapeutic agents. We therefore tested NOX-A12, a high affinity l-oligonucleotide (Spiegelmer) binder to SDF-1in MM, looking at its ability to modulate MM cell tumor growth and MM cell homing to the BM in vivo and in vitro. Methods. Bone marrow (BM) co-localization of MM tumor cells with SDF-1 expressing BM niches has been tested in vivo by using immunoimaging and in vivo confocal microscopy. MM.1S/GFP+ cells and AlexaFluor633-conjugated anti-SDF-1 monoclonal antibody were used. Detection of mobilized MM-GFP+ cells ex vivo has been performed by flow cytometry. In vivo homing and in vivo tumor growth of MM cells (MM.1S-GFP+/luc+) were assessed by using in vivo confocal microscopy and in vivo bioluminescence detection, in SCID mice treated with 1) vehicle; 2) NOX-A12; 3) bortezomib; 4) NOX-A12 followed by bortezomib. DNA synthesis and adhesion of MM cells in the context of NOX-A12 (50–200nM) treated primary MM BM stromal cells (BMSCs), in presence or absence of bortezomib (2.5–5nM), were tested by thymidine uptake and adhesion in vitro assay, respectively. Synergism was calculated by using CalcuSyn software (combination index: C.I. according to Chou-Talalay method). Results. We first showed that SDF-1 co-localizes in the same bone marrow niches of growth of MM tumor cells in vivo. NOX-A12 induced a dose-dependent de-adhesion of MM cells from the BM stromal cells in vitro. These findings were corroborated and validated in vivo: NOX-A12 induced MM cell mobilization from the BM to the peripheral blood (PB) as shown ex vivo, by reduced percentage of MM cells in the BM and increased number of MM cells within the PB of mice treated with NOX-A12 vs. control (BM: 57% vs. 45%; PB: 2.7% vs. 15%). We next showed that NOX-A12-dependent de-adhesion of MM cells from BMSCs lead to enhanced MM cell sensitivity to bortezomib, as shown in vitro, where a synergistic effect between NOX-A12 (50–100 nM) and bortezomib (2.5–5 nM) was observed (C.I.: all between 0.57 and 0.76). These findings were validated in vivo: tumor burden detected by BLI was similar between NOX-A12- and control mice whereas bortezomib-treated mice showed significant reduction in tumor progression compared to the control (P<.05); importantly significant reduction of tumor burden in those mice treated with sequential administration of NOX-A12 followed by bortezomib was observed as compared to bortezomib alone treated mice (P <.05). Similarly, NOX-A12 + bortezomib combination induced significant inhibition of MM cell homing in vivo, as shown by in vivo confocal microscopy, as compared to bortezomib used as single agent. Conclusion. Our data demonstrate that the SDF-1 inhibiting Spiegelmer NOX-A12 disrupts the interaction of MM cells with the BM milieu both in vitro and in vivo, thus resulting in enhanced sensitivity to bortezomib. Disclosures: Roccaro: Roche:. Kruschinski:Noxxon Pharma AG: Employment. Ghobrial:Novartis: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Millennium: Consultancy, Membership on an entity's Board of Directors or advisory committees; Millennium: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Research Funding; Noxxon: Advisory Board, Research Funding.

Download Full-text

Control of PD-L1 expression in CLL-cells by stromal triggering of the Notch-c-Myc-EZH2 oncogenic signaling axis

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-001889 ◽

2021 ◽

Vol 9 (4) ◽

pp. e001889

Author(s):

Martin Böttcher ◽

Heiko Bruns ◽

Simon Völkl ◽

Junyan Lu ◽

Elisavet Chartomatsidou ◽

...

Keyword(s):

Cell Death ◽

B Cells ◽

Programmed Cell Death ◽

Immune Escape ◽

Ex Vivo ◽

Lymphocytic Leukemia ◽

Cell Contact ◽

Dependent Manner ◽

Signaling Axis

Chronic lymphocytic leukemia (CLL) is the most common leukemia in adults. Emerging data suggest that CLL-cells efficiently evade immunosurveillance. T-cell deficiencies in CLL include immuno(metabolic) exhaustion that is achieved by inhibitory molecules, with programmed cell death 1/programmed cell death ligand 1 (PD-L1) signaling emerging as a major underlying mechanism. Moreover, CLL-cells are characterized by a close and recurrent interaction with their stromal niches in the bone marrow and lymph nodes. Here, they receive nurturing signals within a well-protected environment. We could previously show that the interaction of CLL-cells with stroma leads to c-Myc activation that is followed by metabolic adaptations. Recent data indicate that c-Myc also controls expression of the immune checkpoint molecule PD-L1. Therefore, we sought out to determine the role of stromal contact for the CLL-cells’ PD-L1 expression and thus their immuno-evasive phenotype.To do so, we analyzed PD-L1 expression on CLL cell (subsets) in untreated patients and on healthy donor-derived B-cells. Impact of stromal contact on PD-L1 expression on CLL-cells and the underlying signaling pathways were assessed in well-established in vitro niche models. Ex vivo and in vitro findings were validated in the Eµ-TCL1 transgenic CLL mouse model.We found increased PD-L1 expression on CLL-cells as compared with B-cells that was further enhanced in a cell-to-cell contact-dependent manner by stromal cells. In fact, circulating recent stromal-niche emigrants displayed higher PD-L1 levels than long-time circulating CLL-cells. Using our in vitro niche model, we show that a novel Notch-c-Myc-enhancer of zeste homolog 2 (EZH2) signaling axis controls PD-L1 upregulation. Ultimately, elevated PD-L1 levels conferred increased resistance towards activated autologous T-cells.In summary, our findings support the notion that the CLL microenvironment contributes to immune escape variants. In addition, several targetable molecules (eg, Notch or EZH2) could be exploited in view of improving immune responses in patients with CLL, which warrants further in-depth investigation.

Download Full-text