2.26 Clopidogrel (Plavix) Induces In Vivo Reduction of Normal B Cells and In Vitro Apoptosis of B-Cell Chronic Lymphocytic Leukemia Cells

The consistent occurrence of T cell abnormalities in patients with B cell chronic lymphocytic leukemia (B-CLL) suggest that the non- neoplastic host T cells may be involved in the pathogenesis of this B cell neoplasm. Because potential defects of immunoglobulin regulation are evident in B-CLL patients, we investigated one aspect of this by studying the T cell-mediated immunoglobulin isotype-specific immunoregulatory circuit in B-CLL. The existence of class-specific immunoglobulin regulatory mechanisms mediated by Fc receptor-bearing T cells (FcR + T) through soluble immunoglobulin binding factors (IgBFs) has been well established in many experimental systems. IgBFs can both suppress and enhance B cell activity in an isotype-specific manner. We investigated the apparently abnormal IgA regulation in a B-CLL patient (CLL249) whose B cells secrete primarily IgA in vitro. Enumeration of FcR + T cells showed a disproportionate increase in IgA FcR + T cells in the peripheral blood of this patient. Our studies showed that the neoplastic B cells were not intrinsically unresponsive to the suppressing component of IgABF produced from normal T cells, but rather the IgABF produced by the CLL249 host T cells was defective. CLL249 IgABF was unable to suppress IgA secretion by host or normal B cells and enhanced the in vitro proliferation of the host B cells. Size fractionation of both normal and CLL249 IgABF by gel-filtration high- performance liquid chromatography (HPLC) demonstrated differences in the ultraviolet-absorbing components of IgABF obtained from normal T cells v that from our patient with defective IgA regulation. Such T cell dysfunction may not be restricted to IgA regulation, since we have found similar expansion of isotype-specific FcR + T cells associated with expansion of the corresponding B cell clone in other patients with B-CLL. These data suggest that this T cell-mediated regulatory circuit could be significantly involved in the pathogenesis of B-CLL.

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Effect of a thymic factor on T lymphocytes in B cell chronic lymphocytic leukemia: in vitro and in vivo studies

Blood ◽

10.1182/blood.v64.3.667.667 ◽

1984 ◽

Vol 64 (3) ◽

pp. 667-671 ◽

Cited By ~ 7

Author(s):

F Lauria ◽

D Raspadori ◽

S Tura

Keyword(s):

T Cell ◽

Chronic Lymphocytic Leukemia ◽

T Lymphocytes ◽

B Cell ◽

Proliferative Response ◽

Lymphocytic Leukemia ◽

Before And After ◽

Cell Chronic Lymphocytic Leukemia

Abstract Abnormalities of T lymphocytes in B cell chronic lymphocytic leukemia (B-CLL) have been extensively documented by several immunologic investigations. Following recent studies pointing to the favorable effect of TP-1, a partially purified extract of calf thymus, on the T cell-mediated immunity of several diseases, including Hodgkin's disease, we have used monoclonal antibodies and the enriched T lymphocytes of 16 untreated B-CLL patients to evaluate the proportion of T cell subsets before and after the administration of TP-1. In addition, the proliferative response to phytohemagglutinin (PHA) and the helper function in a pokeweed mitogen (PWM) system were assessed. In ten cases, the effect of TP-1 was also studied in vitro by evaluating the same parameters before and after incubation of B-CLL T cells with the drug. The study demonstrated that in vivo administration of TP-1 increases significantly (P less than .001) the proportion of the defective helper/inducer T cell population (OKT4-positive cells) in B-CLL, leading to a near normal OKT4/OKT8 ratio. Furthermore, the improved phenotypic profile was accompanied by an increased proliferative response to PHA and, in particular, by a significant increase (P less than .01) of T helper capacity; this increase was, however, insufficient to enable the normalization of the serum immunoglobulin levels. The in vitro incubation of B-CLL T lymphocytes did not succeed in producing significant modifications in distribution and function.

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Leukemia-associated monoclonal and oligoclonal TCR-BV use in patients with B-cell chronic lymphocytic leukemia

Blood ◽

10.1182/blood-2002-03-0746 ◽

2003 ◽

Vol 101 (3) ◽

pp. 1063-1070 ◽

Cited By ~ 50

Author(s):

Mohammad-Reza Rezvany ◽

Mahmood Jeddi-Tehrani ◽

Hans Wigzell ◽

Anders Österborg ◽

Håkan Mellstedt

Keyword(s):

T Cells ◽

T Cell ◽

B Cells ◽

Chronic Lymphocytic Leukemia ◽

B Cell ◽

Cd8 T Cells ◽

Leukemia Cell ◽

Lymphocytic Leukemia ◽

Cell Chronic Lymphocytic Leukemia

Abstract T-cell receptor–B-variable (TCR-BV) gene usage and the CDR3 size distribution pattern were analyzed by reverse transcription–polymerase chain reaction (RT-PCR) in patients with B-cell chronic lymphocytic leukemia (B-CLL) to assess the T-cell repertoire. The use of TCR-BV families in CD4 and CD8 T cells stimulated with autologous activated leukemic cells was compared with that of freshly obtained blood T cells. Overexpression of individual TCR-BV families was found in freshly isolated CD4 and CD8 T cells. Polyclonal, oligoclonal, and monoclonal TCR-CDR3 patterns were seen within such overexpressed native CD4 and CD8 TCR-BV families. In nonoverexpressed TCR-BV families, monoclonal and oligoclonal populations were noted only within the CD8 subset. After in vitro stimulation of T cells with autologous leukemic B cells, analyses of the CDR3 length patterns showed that in expanded TCR-BV populations, polyclonal patterns frequently shifted toward a monoclonal/oligoclonal profile, whereas largely monoclonal patterns in native overexpressed TCR-BV subsets remained monoclonal. Seventy-five percent of CD8 expansions found in freshly obtained CD8 T cells further expanded on in vitro stimulation with autologous leukemic B cells. This suggests a memory status of such cells. In contrast, the unusually high frequency of CD4 T-cell expansions found in freshly isolated peripheral blood cells did not correlate positively to in vitro stimulation as only 1 of 9 expansions continued to expand. Our data suggest that leukemia cell–specific memory CD4 and CD8 T cells are present in vivo of patients with CLL and that several leukemia cell–associated antigens/epitopes are recognized by the patients' immune system, indicating that whole leukemia cells might be of preference for vaccine development.

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Survivin is expressed on CD40 stimulation and interfaces proliferation and apoptosis in B-cell chronic lymphocytic leukemia

Blood ◽

10.1182/blood.v97.9.2777 ◽

2001 ◽

Vol 97 (9) ◽

pp. 2777-2783 ◽

Cited By ~ 243

Author(s):

Luisa Granziero ◽

Paolo Ghia ◽

Paola Circosta ◽

Daniela Gottardi ◽

Giuliana Strola ◽

...

Keyword(s):

B Cells ◽

Chronic Lymphocytic Leukemia ◽

B Cell ◽

Molecular Mechanisms ◽

Mononuclear Cells ◽

Survivin Expression ◽

Lymphocytic Leukemia ◽

Cd40 Stimulation ◽

Cell Chronic Lymphocytic Leukemia

Abstract In B-cell chronic lymphocytic leukemia (B-CLL), defective apoptosis causes the accumulation of mature CD5+ B cells in lymphoid organs, bone marrow (BM), and peripheral blood (PB). These cells are the progeny of a proliferating pool that feeds the accumulating compartment. The authors sought to determine which molecular mechanisms govern the proliferating pool, how they relate to apoptosis, and what the role is of the microenvironment. To begin to resolve these problems, the expression and modulation of the family of inhibitor of apoptosis proteins (IAPs) were investigated, with consideration given to the possibility that physiological stimuli, such as CD40 ligand (CD40L), available to B cells in the microenvironment, might modulate IAP expression. The in vitro data on mononuclear cells from PB or BM of 30 patients demonstrate that B-CLL cells on CD40 stimulation express Survivin and that Survivin is the only IAP whose expression is induced by CD40L. Through immunohistochemistry, in vivo Survivin expression in lymph node (LN) and BM biopsies was evaluated. In reactive LN, Survivin was detected only in highly proliferating germinal center cells. In LN from patients with B-CLL, Survivin was detected only in pseudofollicles. Pseudofollicle Survivin+ cells were actively proliferating and, in contrast to Survivin+ B cells found in normal GC, were Bcl-2+. In B-CLL BM biopsies, CD5+, Survivin+ cells were observed in clusters interspersed with T cells. These findings establish that Survivin controls the B-CLL proliferative pool interfacing apoptosis and that its expression may be modulated by microenvironmental stimuli.

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Alterations in Cell Surface Phenotype of T- and B-Cell Chronic Lymphocytic Leukemia Cells Following In Vitro Differentiation by Phorbol Ester2

JNCI Journal of the National Cancer Institute ◽

10.1093/jnci/72.5.1059 ◽

1984 ◽

Keyword(s):

Chronic Lymphocytic Leukemia ◽

Cell Surface ◽

B Cell ◽

Phorbol Ester ◽

Lymphocytic Leukemia ◽

Leukemia Cells ◽

In Vitro Differentiation ◽

Surface Phenotype ◽

Cell Chronic Lymphocytic Leukemia

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A6 Peptide Is Selectively Cytotoxic For Chronic Lymphocytic Leukemia Cells

Blood ◽

10.1182/blood.v122.21.5303.5303 ◽

2013 ◽

Vol 122 (21) ◽

pp. 5303-5303

Author(s):

Suping Zhang ◽

Hsien Lai ◽

Grace Liu ◽

Laura Rassenti ◽

Michael Y. Choi ◽

...

Keyword(s):

Hyaluronic Acid ◽

B Cells ◽

Chronic Lymphocytic Leukemia ◽

Lymphocytic Leukemia ◽

Surface Glycoprotein ◽

Leukemia Cells ◽

Dependent Manner ◽

Cell Surface Glycoprotein

Abstract Chronic lymphocytic leukemia (CLL) cells express high levels of CD44, a cell-surface glycoprotein receptor for hyaluronic acid (HA). We found that a mAb specific for CD44 was directly cytotoxic for leukemia B cells, but had little effect on normal B cells. Moreover, this anti-CD44 mAb could induce CLL cells that expressed the zeta-associated protein of 70 kDa (ZAP-70) to undergo caspase-dependent apoptosis, independent of complement or cytotoxic effector cells (Proc Natl Acad Sci, USA 2013, PMID: 23530247). The cytotoxic effect of this mAb was not mitigated when the CLL cells were co-cultured with mesenchymal stromal cells (MSCs) or hyaluronic acid or when they were stimulated via ligation of the B-cell receptor with anti-µ. A6 (Angstrom Pharmaceuticals) is an 8-amino acid peptide that has marked homology with a linear sequence of CD44. A6 can bind CD44 within a region of the ligand-binding domain, leading to inhibition of the migration and metastatic potential of CD44-expressing cancer cells in vitro and in vivo (Mol Cancer Ther, 2011 PMID: 21885863). We evaluated the cytotoxic activity of A6 against primary leukemia cells of patients with CLL (n = 22). We found that A6 peptide also was directly cytotoxic for CLL cells isolated from different patients in a dose-dependent manner at concentrations that may be achieved in vivo. The A6 peptide appeared less cytotoxic for CLL cells than the intact anti-CD44 mAb, but still had greater direct cytotoxicity for CLL cells that expressed ZAP-70 than for CLL cells that were ZAP-70 negative. Furthermore, the A6 peptide had negligible effect on the viability of lymphocytes isolated from the blood of healthy donors (n = 3). Because clinical studies have found the A6 peptide to be well-tolerated and without dose-limiting toxicity in patients with solid tumors who have been treated to date (N = 40), a clinical study is planned to evaluate the safety and activity of the A6 peptide in the treatment of patients with CLL. Disclosures: Howell: Angstrom Phamaceuticals: Membership on an entity’s Board of Directors or advisory committees. Finlayson:Angstrom Phamaceuticals: Employment.

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The novel plant-derived agent silvestrol has B-cell selective activity in chronic lymphocytic leukemia and acute lymphoblastic leukemia in vitro and in vivo

Blood ◽

10.1182/blood-2008-09-175430 ◽

2009 ◽

Vol 113 (19) ◽

pp. 4656-4666 ◽

Cited By ~ 112

Author(s):

David M. Lucas ◽

Ryan B. Edwards ◽

Gerard Lozanski ◽

Derek A. West ◽

Jungook D. Shin ◽

...

Keyword(s):

Acute Lymphoblastic Leukemia ◽

B Cells ◽

Chronic Lymphocytic Leukemia ◽

B Cell ◽

Lymphoblastic Leukemia ◽

Leukemia Cell ◽

Lymphocytic Leukemia ◽

Translational Inhibition

Abstract Therapeutic options for advanced B-cell acute lymphoblastic leukemia (ALL) and chronic lymphocytic leukemia (CLL) are limited. Available treatments can also deplete T lymphocytes, leaving patients at risk of life-threatening infections. In the National Cancer Institute cell line screen, the structurally unique natural product silvestrol produces an unusual pattern of cytotoxicity that suggests activity in leukemia and selectivity for B cells. We investigated silvestrol efficacy using primary human B-leukemia cells, established B-leukemia cell lines, and animal models. In CLL cells, silvestrol LC50 (concentration lethal to 50%) is 6.9 nM at 72 hours. At this concentration, there is no difference in sensitivity of cells from patients with or without the del(17p13.1) abnormality. In isolated cells and whole blood, silvestrol is more cytotoxic toward B cells than T cells. Silvestrol causes early reduction in Mcl-1 expression due to translational inhibition with subsequent mitochondrial damage, as evidenced by reactive oxygen species generation and membrane depolarization. In vivo, silvestrol causes significant B-cell reduction in Eμ-Tcl-1 transgenic mice and significantly extends survival of 697 xenograft severe combined immunodeficient (SCID) mice without discernible toxicity. These data indicate silvestrol has efficacy against B cells in vitro and in vivo and identify translational inhibition as a potential therapeutic target in B-cell leukemias.

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ZAP-70 expression is associated with enhanced ability to respond to migratory and survival signals in B-cell chronic lymphocytic leukemia (B-CLL)

Blood ◽

10.1182/blood-2005-04-1718 ◽

2006 ◽

Vol 107 (9) ◽

pp. 3584-3592 ◽

Cited By ~ 126

Author(s):

Sarah J. Richardson ◽

Christine Matthews ◽

Mark A. Catherwood ◽

H. Denis Alexander ◽

B. Sean Carey ◽

...

Keyword(s):

B Cells ◽

Chronic Lymphocytic Leukemia ◽

B Cell ◽

Actin Polymerization ◽

Chromosomal Abnormalities ◽

Lymphocytic Leukemia ◽

Cellular Migration ◽

Mutational Status ◽

Cell Chronic Lymphocytic Leukemia

Molecular markers like IgVH mutational status, chromosomal abnormalities, and CD38 and ZAP-70 expression have prognostic value in B-cell chronic lymphocytic leukemia (B-CLL). These may be pathogenetic because of the coincidental expression of ZAP-70 and increased B-cell receptor (BCR) signaling and the signaling function of CD38 in CLL. This study shows that ZAP-70+ CLL B cells respond in vitro more readily than ZAP-70– CLL and normal B cells to chemokine migratory signals through enhanced surface CCR7 expression (P = .009; P < .001) and increased responsiveness to its ligands CCL19 and CCL21, demonstrated by F-actin polymerization (P < .05) and cellular migration (P < .01). In addition, ZAP-70+ CLL cells exhibit sustained ERK phosphorylation/activation following stimulation with CXCL12 (SDF1-α, a survival factor produced by stromal cells) compared with ZAP-70– cells (P = .004). Following coculture with nurse-like cells, the survival of ZAP-70+ but not ZAP-70– CLL cells is significantly enhanced by the addition of CXCL12 (P < .05), an effect that is partially blocked by the MEK inhibitor PD98059. These advantageous migratory and survival responses may promote easier access to and greater proliferation in pseudo-germinal centers and explain in part the more progressive nature of ZAP-70+ disease.

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Effect of a thymic factor on T lymphocytes in B cell chronic lymphocytic leukemia: in vitro and in vivo studies

Blood ◽

10.1182/blood.v64.3.667.bloodjournal643667 ◽

1984 ◽

Vol 64 (3) ◽

pp. 667-671

Author(s):

F Lauria ◽

D Raspadori ◽

S Tura

Keyword(s):

T Cell ◽

Chronic Lymphocytic Leukemia ◽

T Lymphocytes ◽

B Cell ◽

Proliferative Response ◽

Lymphocytic Leukemia ◽

Before And After ◽

Cell Chronic Lymphocytic Leukemia

Abnormalities of T lymphocytes in B cell chronic lymphocytic leukemia (B-CLL) have been extensively documented by several immunologic investigations. Following recent studies pointing to the favorable effect of TP-1, a partially purified extract of calf thymus, on the T cell-mediated immunity of several diseases, including Hodgkin's disease, we have used monoclonal antibodies and the enriched T lymphocytes of 16 untreated B-CLL patients to evaluate the proportion of T cell subsets before and after the administration of TP-1. In addition, the proliferative response to phytohemagglutinin (PHA) and the helper function in a pokeweed mitogen (PWM) system were assessed. In ten cases, the effect of TP-1 was also studied in vitro by evaluating the same parameters before and after incubation of B-CLL T cells with the drug. The study demonstrated that in vivo administration of TP-1 increases significantly (P less than .001) the proportion of the defective helper/inducer T cell population (OKT4-positive cells) in B-CLL, leading to a near normal OKT4/OKT8 ratio. Furthermore, the improved phenotypic profile was accompanied by an increased proliferative response to PHA and, in particular, by a significant increase (P less than .01) of T helper capacity; this increase was, however, insufficient to enable the normalization of the serum immunoglobulin levels. The in vitro incubation of B-CLL T lymphocytes did not succeed in producing significant modifications in distribution and function.

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