scholarly journals IL-21 mediates apoptosis through up-regulation of the BH3 family member BIM and enhances both direct and antibody-dependent cellular cytotoxicity in primary chronic lymphocytic leukemia cells in vitro

Blood ◽  
2008 ◽  
Vol 111 (9) ◽  
pp. 4723-4730 ◽  
Author(s):  
Aruna Gowda ◽  
Julie Roda ◽  
Syed-Rehan A. Hussain ◽  
Asha Ramanunni ◽  
Trupti Joshi ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Family Member ◽  
Lymphocytic Leukemia ◽  
Cellular Cytotoxicity ◽  
Antibody Dependent Cellular Cytotoxicity ◽  
Bh3 Domain ◽  
Induced Apoptosis ◽  
Primary Chronic Lymphocytic Leukemia

Abstract Interleukin-21 (IL-21) is a recently identified γ-chain receptor cytokine family member that promotes B-cell apoptosis as well as activation of innate immune system. Based on this, we hypothesized that IL-21 might enhance the apoptosis induced by fludarabine and rituximab and also play a role in augmenting immune-mediated clearance of the chronic lymphocytic leukemia (CLL) cells. Our studies demonstrate that the majority of CLL patients have surface IL-21 receptor-α, and its expression correlates with apoptosis, tyrosine phosphorylation of STAT1, and up-regulation of the proapoptotic BH3 domain protein BIM. IL-21–induced BIM up-regulation is critical for apoptosis because inhibition of BIM expression using small interfering RNA prevented IL-21–induced apoptosis. IL-21 treatment of CLL cells but not normal T cells with fludarabine or rituximab additively enhanced the direct cytotoxic effect of these therapies. In addition to its proapoptotic effect, IL-21 promoted STAT1 and STAT5 phosphorylation in natural killer cells with concurrent enhanced antibody-dependent cellular cytotoxicity against rituximab-coated CLL cells in vitro. These data provide justification for combination studies of IL-21 with fludarabine and rituximab in CLL and suggest that BIM up-regulation might serve as relevant pharmacodynamic end point to measure biologic effect of this cytokine in vivo.

B-1239, a Novel Anti-BAFF-R Afucosylated Human Antibody, Promotes Potent Natural Killer Cell- Mediated Antibody Dependent Cellular Cytotoxicity In Chronic Lymphocytic Leukemia Cells In- Vitro and Depletion Of Circulating Leukemic CLL B Cells In-Vivo

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4185-4185 ◽  
Author(s):  
Emily M. McWilliams ◽  
Carolyn Cheney ◽  
Jeffrey A. Jones ◽  
Joseph M. M. Flynn ◽  
Kami Maddocks ◽  
...  
Keyword(s):  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Cytotoxic Activity ◽  
Natural Killer ◽  
Lymphocytic Leukemia ◽  
Cellular Cytotoxicity ◽  
Antibody Dependent Cellular Cytotoxicity

Abstract B-cell activating factor (BAFF) belongs to the TNF ligand superfamily of cytokines involved in B cell survival and maturation. BAFF is produced by diverse cell types including innate immune cells like monocytes and dendritic cells as well as T cells, activated B cells, and bone marrow stromal cells. BAFF binds to the BAFF receptor (BAFF-R) with high affinity compared to the other BAFF receptors, BCMA and TACI. While BAFF is known to regulate normal B-cell development and proliferation, it also contributes to survival in chronic lymphocytic leukemia (CLL). We observed expression of BAFF-R on virtually all B cells from CLL patients. B-CLL cells have strong up-regulation of BAFF and BAFF-R compared to normal healthy B cells. We describe here the in-vitro and in-vivo evaluation in CLL of B-1239, a fully human anti-BAFF-R monoclonal IgG1 antibody. B-1239 is devoid of fucose residues in its Fc domain, resulting in enhanced binding to FCgammaRIIIa activating receptor on Natural Killer (NK) cells. While B-1239 failed to induce direct or complement mediated cytotoxicity, binding of B-1239 to CLL cells resulted in enhanced antibody dependent cellular cytotoxicity (ADCC) with allogeneic or autologous NK effector cells in-vitro. Indeed, at a therapeutically relevant concentration of 10 ug/mL B-1239 shows more than 30% increased relative cytotoxic activity over current CLL antibody therapeutic Rituximab. Dilutions of B-1239 down to 0.01 ug/mL showed similar cytotoxicity to the 10 ug/mL concentration. At 0.0001 ug/mL B-1239 has a 40% cytotoxic effect on CLL cells in ADCC assays while antibody therapeutic controls, like Rituximab, show virtually no cytotoxic activity. Furthermore, B-1239 mediated antibody-dependent cellular phagocytosis (ADCP) by monocyte-derived macrophages and mediated activation of monocytes and macrophages as detected by TNF-alpha production. Consistent with the cross reactivity to murine BAFF-R, flow cytometric analysis revealed binding of B-1239 to CD5+CD19+ leukemic B cells from Eu-Tcl-1 transgenic mouse CLL cells. A single dose of B-1239 by i.v injection into Eu-Tcl-1 mice resulted in dramatic reduction in circulating CD5+CD19+ leukemic B cells in all three B-1239 injected mice. In contrast, we observed continued increase of leukemic CD5+CD19+ populations in the two vehicle treated mice. Ongoing studies are focused on determining how targeting BAFF-R on CLL B-cells depletes the leukemic population both in-vitro and in-vivo and the downstream effects of targeting through this receptor. Collectively, these results demonstrate that targeting BAFF-R on CLL cells provides a B-cell specific approach for rapid and robust depletion of leukemic CLL cells and provides evidence for a strong therapeutic advantage in BAFF-R targeted therapies in CLL. Disclosures: Huet: Novartis: Employment, Employment Related Perks Other. Gram:Novartis: Employment, Employment Related Perks Other. Baeck:Novartis: Employment, Employment Related Perks Other.

scholarly journals Docosahexaenoic acid induces apoptosis in primary chronic lymphocytic leukemia cells

2015 ◽  
Vol 7 (4) ◽  
Author(s):  
Romain Guièze ◽  
Emmanuel Gyan ◽  
Olivier Tournilhac ◽  
Christelle Halty ◽  
Richard Veyrat-Masson ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Docosahexaenoic Acid ◽  
Lymphocytic Leukemia ◽  
Dependent Manner ◽  
Omega 3 ◽  
Infectious Risk ◽  
Highly Active ◽  
Primary Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia is an indolent disorder with an increased infectious risk remaining one of the main causes of death. Development of therapies with higher safety profile is thus a challenging issue. Docosahexaenoic acid (DHA, 22:6) is an omega-3 fatty acid, a natural compound of normal cells, and has been shown to display antitumor potency in cancer. We evaluated the potential <em>in</em> <em>vitro</em> effect of DHA in primary CLL cells. DHA induces high level of <em>in</em> <em>vitro</em> apoptosis compared to oleic acid in a dose-dependent and time-dependent manner. Estimation of IC50 was only of 4.813 μM, which appears lower than those reported in solid cancers. DHA is highly active on CLL cells <em>in vitro.</em> This observation provides a rationale for further studies aiming to understand its mechanisms of action and its potent <em>in vivo</em> activity.

scholarly journals The antileukemia activity of a human anti-CD40 antagonist antibody, HCD122, on human chronic lymphocytic leukemia cells

Blood ◽  
2008 ◽  
Vol 112 (3) ◽  
pp. 711-720 ◽  
Author(s):  
Mohammad Luqman ◽  
Sha Klabunde ◽  
Karen Lin ◽  
Georgios V. Georgakis ◽  
Anu Cherukuri ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Surface Expression ◽  
Lymphocytic Leukemia ◽  
The Novel ◽  
Antibody Dependent Cellular Cytotoxicity ◽  
Gm Csf ◽  
Tnf Α ◽  
Cd40 Activation ◽  
Induced Apoptosis

Abstract B-cell chronic lymphocytic leukemia (B-CLL) is a lymphoproliferative disorder characterized by the surface expression of CD20, CD5 antigens, as well as the receptor CD40. Activation of CD40 by its ligand (CD40L) induces proliferation and rescues the cells from spontaneous and chemotherapy-induced apoptosis. CD40 activation also induces secretion of cytokines, such as IL-6, IL-10, TNF-α, IL-8, and GM-CSF, which are involved in tumor cell survival, migration, and interaction with cells in the tumor microenvironment. Here we demonstrate that in primary B-CLL tumor cells, the novel antagonist anti-CD40 monoclonal antibody, HCD122, inhibits CD40L-induced activation of signaling pathways, proliferation and survival, and secretion of cytokines. Furthermore, HCD122 is also a potent mediator of antibody-dependent cellular cytotoxicity (ADCC), lysing B-CLL cells more efficiently than rituximab in vitro, despite a significantly higher number of cell surface CD20 binding sites compared with CD40. Unlike rituximab, however, HCD122 (formerly CHIR-12.12) does not internalize upon binding to the cells. Our data suggest that HCD122 may inhibit B-CLL growth by blocking CD40 signaling and by ADCC-mediated cell lysis.

scholarly journals Lenalidomide down-regulates the CD20 antigen and antagonizes direct and antibody-dependent cellular cytotoxicity of rituximab on primary chronic lymphocytic leukemia cells

Blood ◽  
2008 ◽  
Vol 112 (13) ◽  
pp. 5180-5189 ◽  
Author(s):  
Rosa Lapalombella ◽  
Bo Yu ◽  
Georgia Triantafillou ◽  
Qing Liu ◽  
Jonathan P. Butchar ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Surface Antigen ◽  
Targeted Delivery ◽  
Antigen Expression ◽  
Lymphocytic Leukemia ◽  
Cellular Cytotoxicity ◽  
Antibody Dependent Cellular Cytotoxicity ◽  
Surface Antigen Expression ◽  
Primary Chronic Lymphocytic Leukemia ◽  
Anti Cd20

Abstract Lenalidomide, an immunomodulatory agent that enhances antibody-dependent cellular cytotoxicity (ADCC), is currently being investigated as a therapy for chronic lymphocytic leukemia (CLL). The anti-CD20 antibody rituximab is active in CLL and represents a rational agent to combine with lenalidomide. We therefore examined whether lenalidomide combined with rituximab enhances direct apoptosis and ADCC in CLL cells. In contrast to previous reports using CD20-positive lymphoma cell lines, lenalidomide down-regulated CD20 surface antigen expression in CLL patient cells via enhanced internalization, without influencing transcription. The CD20 surface antigen internalization enhanced delivery of an oligonucleotide incorporated into anti-CD20 immunoliposomes. In addition, CD20 surface antigen down-modulation by lenalidomide in CLL was accompanied by diminished rituximab-mediated apoptosis and ADCC. These observations suggest a need for alternative sequencing strategies to avoid antagonism between lenalidomide and rituximab therapy in CLL. In addition, they suggest that lenalidomide therapy might be useful to enhance targeted delivery of RNAi-based therapies using CD20 immunoliposomes in B-cell malignancies.

Sildenafil and vardenafil, types 5 and 6 phosphodiesterase inhibitors, induce caspase-dependent apoptosis of B-chronic lymphocytic leukemia cells

Blood ◽  
2003 ◽  
Vol 101 (1) ◽  
pp. 265-269 ◽  
Author(s):  
Marika Sarfati ◽  
Véronique Mateo ◽  
Sylvie Baudet ◽  
Manuel Rubio ◽  
Christine Fernandez ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Phosphodiesterase Inhibitors ◽  
Inhibitory Effect ◽  
Lymphocytic Leukemia ◽  
Interleukin 4 ◽  
Drug Induced ◽  
Pde Inhibitors ◽  
Induced Apoptosis

Abstract Type 4 phosphodiesterase (PDE4) inhibitors reportedly induce apoptosis in chronic lymphocytic leukemia (CLL) cells. Following clinical improvement of one previously untreated CLL patient with sildenafil therapy, we evaluated the in vitro induction of apoptosis in CLL cells by 4 PDE5/6 inhibitors, including sildenafil, vardenafil, zaprinast, and methoxyquinazoline (MQZ). After 24 hours of culture, the various PDE inhibitors differed in their ability to induce apoptosis, with zaprinast displaying no killing effect. Normal B cells isolated from control donors were totally resistant to PDE-induced apoptosis. Vardenafil was 3 and 30 times more potent an inducer of apoptosis than sildenafil and MQZ, respectively. Both vardenafil and sildenafil failed to elevate adenosine 3′5′ cyclic monophosphate (cAMP) levels, largely excluding an inhibitory effect on cAMP-PDE3, -PDE4, and -PDE7. Vardenafil- or sildenafil-treated B-CLL cells displayed up to 30% intracellular active caspase 3. Drug-induced apoptosis was inhibited by the caspase inhibitor z-VAD.fmk, prevented by interleukin-4 (IL-4), and significantly reduced by stromal-derived factor1-α (SDF-1α). We conclude that vardenafil and sildenafil induce caspase-dependent apoptosis of B-CLL cells in vitro and thus might be considered in the treatment of CLL patients. However, further in vivo investigations should be warranted.

Regulation of Berg-36 Gene Expression by Survival and Apoptotic Stimuli in B-Chronic Lymphocytic Leukaemia Cells.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4767-4767
Author(s):  
Andrew P. Jewell ◽  
Maria Baou ◽  
Kwee L. Yong ◽  
Robert Carr ◽  
John Murphy
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Calcium Ionophore ◽  
Early Response ◽  
Lymphocytic Leukemia ◽  
Apoptotic Cells ◽  
Cd20 Antibody ◽  
Induced Apoptosis ◽  
Anti Cd20

Abstract Chronic lymphocytic leukemia is characterized by the accumulation of monoclonal malignant CD5+ B cells that show resistance to apoptosis in vivo. Berg 36 (ZFP36L1, TIS11b, BRF1, cMG1, ERF1) is a zinc finger containing early response gene that was cloned from PMA-stimulated B chronic lymphocytic leukemia cells. Induced expression of this gene has been linked to calcium ionophore and anti-CD20-induced apoptosis of human B lymphoma cells. Berg36 protein has, in common with two other members of the small gene family (TIS11, TIS11d), been reported to function as an mRNA-binding protein that may promote instability of cytokine mRNAs. We have therefore studied the regulation of Berg36 expression in B-CLL cells in vitro, in response to cytokines and other signals that regulate apoptosis. B-CLL cells from 12 patients were purified and incubated with the following agents either alone or in combinations for a number of hours; IL-4, CD40 ligand, PMA or anti-CD20 antibody (rituximab). Apoptosis was measured after 24 hours by Annexin/PI staining and Berg-36 expression by Northern blot analysis. Spontaneous apoptosis in unstimulated B-CLL cells was 20.9±5.1%. Co-incubation of B-CLL cells with IL-4 reduced the percentage of apoptotic cells to 6.2±1.2%, but had no effect on Berg-36 expression. In contrast, both PMA and CD40 stimulation reduced the percentage of apoptotic cells (to 14.8±3.4% and 10.2±4.2% respectively), and markedly induced Berg36 expression. On the other hand, anti-CD20 antibody induced apoptosis (36.2±6.6%), but also induced Berg36 expression. Specific inhibitors of various intracellular signalling molecules confirmed that induction of Berg36 by different agents was mediated through different signalling pathways. In conclusion, expression of Berg36 can be induced in B-CLL cells by stimuli that induce either survival or apoptosis in these cells.

Sign in / Sign up

Export Citation Format

Share Document