Relation of Neutrophil Gelatinase-Associated Lipocalin Overexpression to the Resistance to Apoptosis of Tumor B Cells in Chronic Lymphocytic Leukemia

The resistance to apoptosis of chronic lymphocytic leukemia (CLL) cells partly results from the deregulated production of survival signals from leukemic cells. Despite the development of new therapies in CLL, drug resistance and disease relapse still occur. Recently, neutrophil gelatinase-associated lipocalin (NGAL), a secreted glycoprotein, has been suggested to have a critical role in the biology of tumors. Thus, we investigated the relevance of NGAL in CLL pathogenesis, analyzed the expression of its cellular receptor (NGAL-R) on malignant B cells and tested whether CLL cells are resistant to apoptosis through an autocrine process involving NGAL and NGAL-R. We observed that NGAL concentrations were elevated in the serum of CLL patients at diagnosis. After treatment (and regardless of the therapeutic regimen), serum NGAL levels normalized in CLL patients in remission but not in relapsed patients. In parallel, NGAL and NGAL-R were upregulated in leukemic cells from untreated CLL patients when compared to normal peripheral blood mononuclear cells (PBMCs), and returned to basal levels in PBMCs from patients in remission. Cultured CLL cells released endogenous NGAL. Anti-NGAL-R antibodies enhanced NGAL-R+ leukemia cell death. Conversely, recombinant NGAL protected NGAL-R+ CLL cells against apoptosis by activating a STAT3/Mcl-1 signaling pathway. Our results suggest that NGAL and NGAL-R, overexpressed in untreated CLL, participate in the deregulation of the apoptotic machinery in CLL cells, and may be potential therapeutic clues for CLL treatment.

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Increased Expression of PD-1 on CD4+ T Cells from Patients with Chronic Lymphocytic Leukemia

Blood ◽

10.1182/blood.v112.11.4154.4154 ◽

2008 ◽

Vol 112 (11) ◽

pp. 4154-4154

Author(s):

Mary M Sartor ◽

David J Gottlieb

Keyword(s):

T Cells ◽

B Cells ◽

Chronic Lymphocytic Leukemia ◽

Nk Cells ◽

Cd4 T Cells ◽

Mononuclear Cells ◽

Lymphocytic Leukemia ◽

Effector Memory ◽

Cd4 Cells ◽

Normal Peripheral Blood

Abstract Although the predominant finding in patients with chronic lymphocytic leukemia (CLL) is an expansion of monoclonal B lymphocytes, a polyclonal expansion of T cells co-exists in CLL patients. Allogenic stem cell transplants for CLL suggest that a significant graft versus leukaemia effect mediated through recognition of minor MHC or leukaemia specific antigens can be achieved. Since it appears that the immune system and probably T cells recognise CLL cells, it is possible that one or more T cell defects might contribute to the initiation or maintenance of a clone of CLL lymphocytes. PD-1 is a coinhibitory molecule that is expressed on T cells in patients with chronic viral infections. It has been suggested that PD-1 expression might be a marker of cell exhaustion due to antigenic overstimulation. We examined the expression of PD-1 and its naturally occurring ligands PD-L1 and PD-L2 on both B and T cells in patients with CLL and compared this with expression on normal peripheral blood mononuclear cells. We found that PD-1 was expressed on over 10% of CD4+ T cells in 7 of 9 cases of CLL (mean 22±16%) but not on CD4+ T cells in any of 9 normal donors (mean 0±0%), p=0.0009. There was no difference in PD-1 expression on CD8+ or CD14+ PBMCs from CLL patients and normal donors (for CD8+ 24±21% and 19±16% for CLL and normals; for CD14+ 58±16% and 71±31% for CLL and normals). More than 10% of CD5+/19+ CLL cells expressed PD-1 in 7 of 10 cases (mean 18±18%) while more than 10% of normal B cells from 6 of 7 donors also expressed PD-1 (mean 49±30%). We examined the expression of PD-1 on naïve, central memory, effector memory and terminally differentiated subsets of CD4+ cells (CD62L+CD45RA+, CD62L+CD45RA−, CD62L−CD45RA− and CD62L−CD45RA+ respectively) from CLL patients and normal donors. The expression of PD-1 was higher on CD4+ cells from CLL patients in all subsets. The effect was most prominent in the effector memory subset (mean 54±4% for CLL patients versus 26±17% for normal donors, p=0.02). We looked for expression of PD-L1 and PD-L2 on T cells, B cells, monocytes and NK cells from CLL patients and normal donors. PD-L1 was only expressed on monocytes (mean 30±23%) and NK cells (mean 14±19%) from CLL patients and on monocytes from normal donors (mean 35±26%). There was no expression of PD-L2 on any cell type in either CLL patients or normal donors. We conclude that there is increased expression of the co-inhibitory molecule PD-1 on CD4+ T cells in patients with CLL. Ligation of PD-1 by PD-L1 expressed on monocytes or NK cells could inhibit immune responses to tumor and infectious antigens leading to persistence of clonally expanded cells and predisposition to opportunistic pathogens.

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Role of Hematopoietic-Specific Protein 1 (HS1) in Apoptosis in B-Chronic Lymphocytic Leukemia.

Blood ◽

10.1182/blood.v108.11.2809.2809 ◽

2006 ◽

Vol 108 (11) ◽

pp. 2809-2809

Author(s):

Livio Trentin ◽

Antonella Contri ◽

Anna Maria Brunati ◽

Federica Frezzato ◽

Martina Frasson ◽

...

Keyword(s):

B Cells ◽

Chronic Lymphocytic Leukemia ◽

Cell Survival ◽

B Lymphocytes ◽

Lymphocytic Leukemia ◽

Leukemic Cells ◽

Cell Fractionation ◽

Normal Peripheral Blood ◽

Protein Levels ◽

The Mean

Abstract B-cell chronic lymphocytic leukemia (B-CLL) is the most common leukemia in adults and is characterized by the accumulation of clonal CD5+ B lymphocytes. Several protein kinase pathways have been claimed to be involved in the regulation of apoptosis and cell survival. We previously demonstrated that Src kinase Lyn is overexpressed at the protein level in leukemic cells as compared to normal B lymphocytes with substantial amount of the kinase anomalously present in the cytosol. Moreover, most of Lyn is constitutively active in resting leukemic cells and is poorly responsive to BCR engagement. The finding that B CLL cells contained cytosolic Lyn fraction and are defective in programmed cell death suggest that the tyrosine phosphorlation of specific cytosolic targets might account, at least in part, for cell resistance to apoptosis. The 75 KDa HS1 protein is one of the major substrate of Lyn kinase upon BCR cross-linking that plays a crucial role in BCR- induced apoptosis in the mouse B lymphoma cell line WEHI-231. A recent study demonstrates that most HS1 protein was constitutively phosphorylated in B CLL patients with poor prognosis whereas only a fraction was phosphorylated in patients with good prognoses. In the present study, the relative HS1 protein levels were measured by Western blot analysis in 50 CLL patients belonging to different clinical stages. The relative HS1 protein levels were compared with corresponding levels in normal peripheral blood and with Jurkat cells. For normal B cells, the mean ± SD for HS1: actin ratio was 0,88 ± 0,10. There was considerable variation in the levels of HS1/actin ratio in CLL cells, which ranged from 0,49 to 2,50. Thus, compared to normal B cells, 15 CLL patients had a HS1 level which fell within the mean ± 1SD HS1 levels for normal B cells, while 9 patients had lower levels and 26 patients had higher levels. When assessed by flow cytometry, HS1 expression was normally distributed among CLL cells in individual patients and the mean levels correlated with those obtained by Western blotting. A difference in the levels of HS1 was also observed between mutated and unmutated patients. Using confocal microscopy and subcellular cell fractionation, we observed that HS1 protein was abnormally distributed in malignant cells as compare with normal B cells: a 4–7% aliquot of HS1 was anomalously present in the nucleus of leukemic cells. When primary CLL cells were in vitro treated whith dexamethazone, cyclosporin A, chlorambucil, or fludarabine the HS1 levels decreased correlating with the sensitivity of these cells to undergo apoptosis. Using a polyclonal antiserum against HS1 a major cleavage product of the apparent molecular weight of 64 KDa and one minor product of approximately 46 Kda was detected in B CLL cells cultured for 24 hours whith drugs. These findings suggest that HS1 plays a pivotal role in the regulation of cell survival of leukemic B cells and suggest that HS1 might represent a target for the development of new drugs to be used in vivo in these patients.

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Inversely Association of the Aiolos Transcription Factor with Clinical Progression in Chronic Lymphocytic Leukemia.

Blood ◽

10.1182/blood.v112.11.2069.2069 ◽

2008 ◽

Vol 112 (11) ◽

pp. 2069-2069

Author(s):

Holger Nückel ◽

Ulrich H Frey ◽

Ludger Sellmann ◽

Crista H Collins ◽

Ulrich Duehrsen ◽

...

Keyword(s):

Transcription Factor ◽

B Cells ◽

Mononuclear Cells ◽

Critical Role ◽

Lymphocytic Leukemia ◽

Pcr Analysis ◽

Peripheral Blood Mononuclear ◽

Normal Peripheral Blood ◽

Cd38 Expression ◽

Important Regulator

Abstract Introduction: Aiolos encode a hemopoietic-specific zinc-finger transcription factor that is an important regulator of lymphocyte differentiation and plays a critical role in regulating B-cell development. RT-PCR analysis of the Aiolos gene expression revealed 16 Aiolos splicing variants, which have been named according to the exons missing from the full-length isoform. Recent data suggest that over 80% of expressed Aiolos in normal as well as in malignant B-cells is of the hAio1 type. Therefore, we investigated Aiolos mRNA expression (hAio1 type) in a large cohort with 155 patients along with the most commonly used biological markers in order to assess its role in risk prediction in B-CLL. Methods and Results: The total amount of Aiolos transcripts in B-cells of 155 CLL patients using normal peripheral blood mononuclear cells represented a continuum ranging from 2.5- to 37-fold upregulation compared to that of normal B-cells, with a median of 20- fold upregulation. Moreover, Aiolos expression in B-CLL was significantly upregulated compared to cells of AML (113-fold; p<0.0001), ALL (14-fold; p=0.0024), CML (154- fold; p<0.0001), multiple myeloma (38-fold; p=0.0018) or NHL (16-fold; p<0.0001) suggesting that this Aiolos transcript is highly expressed specifically in B-CLL cells Patients with high Aiolos expression (according to ROC-analysis) had a significantly longer treatment-free survival (TFS) and overall survival (OS) than patients with low Aiolos expression (median TFS: 119 versus 45 months, p=0.005; median OS: 321 versus 244 months, p=0.0065). Evaluation of several disease characteristics in association with the Aiolos expression status of the patients’ B-CLL cells showed no significant differences for ZAP-70 expression (p=0.28), CD38 expression (p=0.067), IgVH status (p=0.49) and Binet stage (p=0.13) suggesting no correlation of Aiolos expression with these already established adverse prognostic factors. In multivariate analysis low Aiolos expression was an independent prognostic factor with significance for trend (hazard ratio 1.413; p=0.069). Sequential analyses in a subset of 10 CLL patients revealed that Aiolos expression was relatively stable over time in the majority of patients. Conclusions: Here we demonstrate for the first time that the level of Aiolos expression is correlated with prognosis in B-CLL. The exact causes and consequences of this upregulation on the survival of CLL B-cells and the demonstrated better prognosis have yet to be determined. However, Aiolos may function as a tumor suppressor by controlling the cell cycle and DNA replication.

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BAFF Support Survival of Chronic Lymphocytic Leukemia B Cells by a Pathway Independent of Stromal Derived Factor-1α.

Blood ◽

10.1182/blood.v104.11.1908.1908 ◽

2004 ◽

Vol 104 (11) ◽

pp. 1908-1908

Author(s):

Mitsufumi Nishio ◽

Nobuhiro Tsukada ◽

Shinichi Kitada ◽

Junko Ohata ◽

Nathan J. Zvaifler ◽

...

Keyword(s):

B Cells ◽

Chronic Lymphocytic Leukemia ◽

Cell Survival ◽

Mononuclear Cells ◽

Leukemia Cell ◽

Lymphocytic Leukemia ◽

Mitogen Activated Protein Kinase ◽

Peripheral Blood Mononuclear ◽

Cells Cultured

Abstract We examined the peripheral blood mononuclear cells (PBMC) of patients with chronic lymphocytic leukemia (CLL) for expression of B cell-activating factor of the TNF family (BAFF). Isolated CLL B cells had significantly lower levels of BAFF mRNA than did non-separated PBMC. Most of the BAFF mRNA in PBMC was due to contaminating CD14+ cells that previous studies found could differentiate into “nurselike” cells (NLC) when cultured with CLL B cells in vitro. We found NLC expressed high-levels of BAFF and stromal cell-derived factor-1 alpha (SDF-1α), in contrast to CLL B cells. CLL B cells cultured with exogenous recombinant human BAFF (rhBAFF), SDF-1α, or NLC sustained significantly greater viability than isolated CLL B cells cultured alone. The effect(s) of rhBAFF on leukemia cell survival appeared additive and distinct from that of SDF-1α, which in contrast to rhBAFF induced leukemia-cell phosphorylation of p44/42 mitogen-activated protein-kinase (ERK 1/2) and phosphorylation and activation of AKT at Ser473. However, rhBAFF, but not SDF-1α, could induce processing of p100 NF-κB2 to p52 and, like NLC, enhance and/or maintain CLL-cell expression of the anti-apoptotic protein Mcl-1. We conclude that BAFF can function in a paracrine manner to support leukemia cell survival via mechanisms that are distinct from those of SDF-1α and that NLC use multiple distinct pathways to support CLL-cell survival.

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Pharmacologic Modulation of STAT1 and Wnt Signaling in Chronic Lymphocytic Leukemia

Blood ◽

10.1182/blood.v126.23.4150.4150 ◽

2015 ◽

Vol 126 (23) ◽

pp. 4150-4150

Author(s):

Christina Wu ◽

Fitzgerald S Lao ◽

Michael Y. Choi ◽

Dennis A. Carson

Keyword(s):

Wnt Signaling ◽

Mononuclear Cells ◽

Leukemia Cell ◽

Xenograft Model ◽

Advisory Board ◽

Lymphocytic Leukemia ◽

Leukemic Cells ◽

Peripheral Blood Mononuclear ◽

Normal Peripheral Blood

Abstract BACKGROUND: The STAT and Wnt signaling pathways play critical roles in early lymphocyte development and function, with considerable cross-talk between them. STAT1 has been reported to be constitutively phosphorylated at SER727, and often at TYR701, in CLL patients. STAT1 activation can regulate the function of the IRF8 transcription factor. Polymorphisms of the IRF8 gene have been associated with both familial and sporadic CLL, and can influence Wnt signaling. Hence, both STAT1 and Wnt are potential pharmacologic targets for CLL therapy, particularly in patients that are resistant to, or intolerant of BTK and PI3K inhibitors. We previously reported that the electrophilic drug dimethylfumarate (DMF, Tecfidera, Fumaderm) could inhibit Wnt signaling in CLL. Here we have investigated its effects on constitutive and inducible STAT1 signaling, and on IRF8 expression, in primary CLL cells. METHODS: Primary leukemia cells from patients with CLL were cultured with DMF at pharmacologically relevant doses (3 uM to 30 uM) for 4 hours prior to analysis of STAT1 phosphorylation and IRF8 expression. We assessed the effect of DMF with and without pre-stimulation by lipopolysaccharide (LPS), Wnt3a, or a TLR7 agonist. To further evaluate the effect on CLL cells in a microenvironment that stimulates these pathways, we utilized a murine CLL xenograft model. We implanted primary leukemic cells from patients with CLL into the peritoneum of Rag2 deficient immune-compromised mice. Groups of mice were then treated with DMF at a dose of 10 mg/kg by oral gavage. CLL cells were retrieved 4 to 5 hours later by peritoneal lavage and analyzed. RESULTS: We confirmed that both SER727 and TYR701 are phosphorylated in the majority of primary CLL cells from both VH mutated (high risk) and unmutated (low risk) clones, but not in normal peripheral blood mononuclear cells (PBMC). A 4 hours exposure of CLL cells to DMF inhibited TYR701 phosphorylation, but had no effect on SER727 phosphorylation nor on total STAT1 levels. We also confirmed that IRF8 levels are 6-8 fold elevated in CLL cells, compared to normal PBMC. IRF8 expression was inhibited by DMF treatment in 7 out of 11 CLL patients. Similar effects were observed in vivo. Wnt or LPS stimulation increased IRF8 levels in normal PBMC, but did not alter the already elevated IRF8 levels in CLL cells. CONCLUSIONS: Activation of the STAT1/IRF8 pathway, like the Wnt pathway, is highly characteristic of CLL. DMF treatment of CLL cells can interrupt these signaling cascades, interfering with leukemia cell survival. Disclosures Choi: AbbVie: Consultancy, Other: Advisory Board, Research Funding; Gilead: Consultancy, Other: Advisory Board, Speakers Bureau.

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Monoglycerides induce apoptosis in human leukemic cells while sparing normal peripheral blood mononuclear cells

Blood ◽

10.1182/blood-2002-03-0894 ◽

2003 ◽

Vol 101 (1) ◽

pp. 292-294 ◽

Cited By ~ 6

Author(s):

Fabianne Philippoussis ◽

Chantal Arguin ◽

Véronique Mateo ◽

Ann-Muriel Steff ◽

Patrice Hugo

Keyword(s):

Peripheral Blood Mononuclear Cells ◽

Peripheral Blood ◽

Mononuclear Cells ◽

Human Peripheral Blood ◽

Lymphocytic Leukemia ◽

Leukemic Cells ◽

Major Drawback ◽

Peripheral Blood Mononuclear ◽

Normal Peripheral Blood ◽

Blood Mononuclear Cells

Abstract A major drawback of the current antineoplastic treatments is their lack of specificity toward cancer cells, because they are most often cytotoxic to normal cells, thus creating related side effects. Hence, the identification of new apoptosis-inducing agents, specifically targeting malignant cells while sparing their normal counterparts, is of crucial interest. We show here that monoglycerides, a family of lipids consisting of a single fatty acid attached to a glycerol backbone, induce cell death in several human leukemic cell lines. Importantly, treatment of primary leukemic cells, obtained from B-cell chronic lymphocytic leukemia patients, resulted in rapid apoptosis. In striking contrast, resting or activated human peripheral blood mononuclear cells from healthy individuals were resistant to the same treatment. Therefore, these compounds could represent potential antileukemic drugs or could allow for the design of novel therapeutic agents applied to leukemia.

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Aberrant expression of B-lymphocyte stimulator by B chronic lymphocytic leukemia cells: a mechanism for survival

Blood ◽

10.1182/blood-2002-02-0558 ◽

2002 ◽

Vol 100 (8) ◽

pp. 2973-2979 ◽

Cited By ~ 164

Author(s):

Anne J. Novak ◽

Richard J. Bram ◽

Neil E. Kay ◽

Diane F. Jelinek

Keyword(s):

B Cells ◽

Chronic Lymphocytic Leukemia ◽

B Cell ◽

B Lymphocyte ◽

Leukemic Cell ◽

Lymphocytic Leukemia ◽

Leukemic Cells ◽

Aberrant Expression ◽

B Lymphocyte Stimulator

B-cell chronic lymphocytic leukemia (B-CLL) is defined by the accumulation of CD5+ B cells in the periphery and bone marrow. This disease is not characterized by highly proliferative cells but rather by the presence of leukemic cells with significant resistance to apoptosis and, therefore, prolonged survival. B-lymphocyte stimulator (BLyS) is a newly identified tumor necrosis factor (TNF) family member shown to be critical for maintenance of normal B-cell development and homeostasis and it shares significant homology with another TNF superfamily member, APRIL. The striking effects of BLyS on normal B-cell maintenance and survival raises the possibility that it may be involved in pathogenesis and maintenance of hematologic malignancies, including B-CLL. In this study, we investigated the status of APRIL and BLyS expression, as well as their receptors, in this disease. All B-CLL patient cells studied expressed one or more of 3 known receptors for BLyS; however, the pattern of expression was variable. In addition, we demonstrate for the first time that B-CLL cells from a subset of patients aberrantly express BLyS and APRIL mRNA, whereas these molecules were not detectable in normal B cells. Furthermore, we provide in vitro evidence that BLyS protects B-CLL cells from apoptosis and enhances cell survival. Because these molecules are key regulators of B-cell homeostasis and tumor progression, leukemic cell autocrine expression of BLyS and APRIL may be playing an important role in the pathogenesis of this disease.

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Increased Proportion of Complement-Receptor Lymphocytes in the Peripheral Blood of Patients With Chronic Lymphocytic Leukemia

Blood ◽

10.1182/blood.v40.3.303.303 ◽

1972 ◽

Vol 40 (3) ◽

pp. 303-310 ◽

Cited By ~ 82

Author(s):

Seth Pincus ◽

Celso Bianco ◽

Victor Nussenzweig

Keyword(s):

Lymph Node ◽

Chronic Lymphocytic Leukemia ◽

Peripheral Blood ◽

Mononuclear Cells ◽

Peripheral Blood Lymphocytes ◽

Lymphocytic Leukemia ◽

Complement Receptor ◽

Normal Peripheral Blood ◽

Present Evidence ◽

Normal Individuals

Abstract In the present study we present evidence that the proportion of complement-receptor lymphocytes (CRL) is greatly increased in the circulation in most cases of chronic lymphocytic leukemia (CLL). Lymphocytes (> 99% pure, 70% recovery) were obtained from the peripheral blood of normal individuals by separation of the mononuclear cells from the leukocyte-enriched plasma by differential flotation in Hypaque-Ficoll and incubation of the mononuclear cells with iron-containing particles followed by removal of the phagocytes with a magnet. Complement - receptor lymphocytes were detected by incubating lymphocytes with sheep erythrocytes coated with antibody and mouse complement (EAC) and counting the EAC—CRL rosettes under the microscope. 7.1 ± 3.8% of normal peripheral blood lymphocytes, 31.0 ± 6.9% of lymph node, and 59.6 ± 13.2% of tonsil lymphocytes bind EAC. The binding was C3-dependent since it could be inhibited specifically by papain fragments of rabbit antibodies to mouse C3. Among lymphocytes from the peripheral blood of patients with CLL, 50.7 ± 25.0% bear the complement receptor. These results suggest that CLL preferentially affects B cells.

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Evidence for progenitors of chronic lymphocytic leukemia B cells that undergo intraclonal differentiation and diversification

Blood ◽

10.1182/blood.v87.4.1586.bloodjournal8741586 ◽

1996 ◽

Vol 87 (4) ◽

pp. 1586-1594 ◽

Cited By ~ 27

Author(s):

M Dono ◽

S Hashimoto ◽

F Fais ◽

V Trejo ◽

SL Allen ◽

...

Keyword(s):

B Cells ◽

Chronic Lymphocytic Leukemia ◽

B Cell ◽

Dna Sequences ◽

Mononuclear Cells ◽

Lymphocytic Leukemia ◽

Specific Primers ◽

Region Gene ◽

Peripheral Blood Mononuclear ◽

Ancestral Gene

Peripheral blood mononuclear cells from five patients with IgG+ B-type chronic lymphocytic leukemia (B-CLL) were analyzed for the presence of clone-specific Ig H chain variable region gene mRNA transcripts linked to C mu and/or C alpha. This was assessed by (1) comparing the lengths of portions of the VHDJH of the IgG+ CLL clones with those of the mu and alpha isotype-expressing B cells, (2) performing clone-specific endonuclease digestion studies, and (3) determining the DNA sequences of the mu and alpha isotype-expressing cDNA. Thus, when B-cell mRNA from these five patients were reverse transcribed with C gamma-specific primers and then amplified by polymerase chain reaction, dominant cDNA were found with lengths corresponding to those of the IgG+ CLL B cell. In addition, in four cases, cDNA of lengths identical to those of the CLL B cell were detected when mRNA was reverse transcribed and amplified using c mu- and/or C alpha-specific primers, strongly suggesting clonal relatedness. These CLL-related mu- and alpha- expressing cDNA were present in greater amounts that unrelated (non- CLL) mu- and alpha-expressing cDNA from normal B cells that used genes of the same VH family. When the sequences of these CLL-related C mu- and C alpha-expressing cDNA were compared with those of the IgG+ CLL clones, it was clear that they were derived from the same ancestral gene as the IgG-expressing CLL B cell, thus documenting their common origin. Finally, nucleotide point mutations were observed in the mu- and alpha-expressing cDNA of certain patients, indicating divergence with the CLL. These data suggest that IgM+ B cells, which are precursors of the leukemic B cells, exist in increased numbers in the blood of most patients with IgG+ B-CELL and that these cells may differentiate, accumulate V genes mutations, and undergo isotype switching in vivo. In addition, the data are consistent with a sequential-hit model for the evolution of CLL.

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The Receptor for Hyaluronic Acid Mediated Motility (RHAMM/CD168) Is a Potential Target for Immunotherapy of Patients with B-Cell Chronic Lymphocytic Leukemia.

Blood ◽

10.1182/blood.v106.11.53.53 ◽

2005 ◽

Vol 106 (11) ◽

pp. 53-53 ◽

Cited By ~ 1

Author(s):

Krzysztof Giannopoulos ◽

Iwona Hus ◽

Li Li ◽

Agnieszka Bojarska-Junak ◽

Jochen Greiner ◽

...

Keyword(s):

T Cells ◽

Chronic Lymphocytic Leukemia ◽

B Cell ◽

Mononuclear Cells ◽

Tissue Expression ◽

T Cell Response ◽

Lymphocytic Leukemia ◽

Leukemic Cells ◽

Peripheral Blood Mononuclear ◽

Cell Chronic Lymphocytic Leukemia

Abstract Definition of appropriate target antigens might open new avenues to antigen targeted immunotherapies for patients with B-cell chronic lymphocytic leukemia (B-CLL). We screened the mRNA expression of tumor associated antigens (TAAs), from the literature (fibromodulin, survivin, OFA-iLRP, BAGE, G250, MAGE1, PRAME, proteinase, Syntaxin, hTERT, WT-1), and TAAs defined earlier by serological analysis of cDNA expression libraries from leukemic cells (PINCH, HSJ2, MAZ, MPP11, RHAMM/CD168, NY-Ren60). Peripheral blood mononuclear cells from 43 B-CLL patients and 20 healthy volunteers (HVs) were examined by conventional and quantitative RT-PCR. mRNA of RHAMM/CD168, fibromodulin, syntaxin and NY-Ren60 was expressed in 55–90%, mRNA of HSJ2, MAZ and OFA-iLRP in 90–100% of the patients. No expression of WT-1, h-TERT, BAGE, G250, MAGE1 and survivin was observed. Low (2–20%) expression frequencies of MPP11, PINCH, PRAME and proteinase were detected. RHAMM/CD168, fibromodulin, PRAME and MPP11 showed expression in B-CLL patients, but not in HVs. Because of the exquisite tissue expression of RHAMM/CD168 and its high expression frequency in B-CLL patients even in early stages of disease, mixed lymphocyte peptide culture (MLPC), enzyme-linked immunosorbent spot (ELISPOT) and flow cytometry were performed for antigen specific T cells. In MLPC, RHAMM specific responses by CD8+HLA-A2/R3tetramer+CCR7-CD45RAhigh effector T cells were detected. Moreover, we observed an enhanced RHAMM/CD168 specific CD8+ T cell response after vaccination in one from four HLA-A2 positive B-CLL patients vaccinated with tumor cell lysate pulsed dendritic cells. Therefore, RHAMM/CD168 is an interesting candidate antigen for future immunotherapies in both ZAP-70 (+) and ZAP-70 (−) B-CLL patients.

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