Chronic Lymphocytic Leukemia Associated with Autoimmune Diseases Often Discloses Activated Phenotype Pattern.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4802-4802
Author(s):  
Adrian Duek ◽  
Lev Shvidel ◽  
Alain Berrebi ◽  
Osnat Bairey ◽  
Andre Braester ◽  
...  
Keyword(s):  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
Autoimmune Diseases ◽  
B Lymphocytes ◽  
De Novo ◽  
Autoimmune Disorders ◽  
Lymphocytic Leukemia ◽  
Activation Markers ◽  
Activated Lymphocytes ◽  
Positive Direct

Abstract In autoimmune diseases the production of auto reactive antibodies is related to activation of normal B-lymphocytes. The high incidence of autoimmune disorders (AID) in CLL is well known, but the origin of auto antibodies is controversial. In the present study we postulate that Chronic Lymphocytic Leukemia associated with autoimmune diseases discloses activated phenotype pattern. Out of the 891 CLL patients registered in the Israeli Study Group, we found 72 patients (8%) who presented at least one clinically expressed autoimmune disease at diagnosis. Median age was 67 years old (range 45–87). 44% were male, 45 patients were at Binet`s stage A, 17 patients at Stage B and 4 at Stage C, and six patients were diagnosed with de novo PLL. The autoimmune disorders were as follows: Hashimoto`s disease (25), AIHA (11), Sjogren`s syndrome (10), rheumatoid arthritis (9), vasculitis (8), Grave’s disease (5), Evan’s syndrome (4), ITP (4), multiple sclerosis (2) and pernicious anemia, pure red cells aplasia, Raynaud`s syndrome, systemic erythematous lupus, ulcerative colitis (each-one). We found also 19 cases of positive direct antiglobulin test, 7 cases of positive rheumatoid factor, 4 cases with positive antinuclear antibodies, and 7 cases of hypocomplementemia. In 16 patients (22%) the morphology cell was consistent with activated lymphocytes (more than 30% of prolymphocytes). Immunophenotype analysis revealed increased expression (>30%) of activation markers CD38 or FMC7 in 27%. IgG was higher than 1000 mg/dl in 57%, while 5 cases found with IgM paraproteinemia. Increased Beta2- microglobulin level, described by us correlating the activation of B-CLL cells, was increased in 78% of tested cases. The new marker ZAP 70 analyzed in seven patients and found positive in 5. Interestingly, Beta2m and CD38 wich usually define agressive disease were found predominatly in stage A patients with AID. Our results suggest that in B- CLL associated with autoimmune disorders, the B CLL cells present some degree of activation. It is well known that B-lymphocytes in CLL are in a preactivated state and can be induced to differentiate into plasma cells and to stimulate residual normal B cells to produce high-affinity polyclonal autoantibodies with restricted specificity and pathogenic properties. This possibility would be in keeping with our observation. Conclusion: our data showing activated lymphocytes morphology and /or increased expression CD38 or FMC7, high level of IgG and of Beta2-m in most of the cases, suggests that a state of activation of B-cells may correlate with the occurrence of autoimmune complication in B-CLL.

scholarly journals Production of autoantibodies by CD5-expressing B lymphocytes from patients with chronic lymphocytic leukemia.

1989 ◽  
Vol 169 (1) ◽  
pp. 255-268 ◽  
Author(s):  
Z M Sthoeger ◽  
M Wakai ◽  
D B Tse ◽  
V P Vinciguerra ◽  
S L Allen ◽  
...  
Keyword(s):  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
B Lymphocytes ◽  
Autoimmune Disorders ◽  
Lymphoproliferative Disorders ◽  
Lymphocytic Leukemia ◽  
Antigenic Specificity ◽  
Human B Cells ◽  
Well Differentiated

CD5-expressing B lymphocytes from patients with selected chronic lymphoproliferative disorders were used to determine whether monoclonal populations of CD5+ human B cells produce autoantibodies. CD5+ B cells from 19 patients with chronic lymphocytic leukemia (CLL) and one with diffuse well-differentiated lymphocytic lymphoma (DWDL) were cultured, with and without mitogenic stimulation, to obtain Ig from these cells. 17 of the 20 samples produced Ig in vitro. mAb from nine of the 17 patients were reactive with either IgG, ssDNA, or dsDNA. In every instance, the autoantibodies displayed monotypic L chain usage that correlated precisely with the L chain expressed on the CD5+ leukemic B cell surface. These monoclonal autoantibodies varied in their degree of antigenic specificity; some were quite specific, reacting with only one antigen, whereas others were polyspecific, reacting with two or all three autoantigens tested. Three features distinguish these autoantibodies from those observed in prior studies of CD5+ B cells. First, they are clearly the products of monoclonal populations of CD5+ cells; second, several react with dsDNA, a specificity not previously reported and often seen in association with significant autoimmune disorders; and third, two of the monoclonal autoantibodies secreted by the CD5+ clones were of the IgG class. Although not all of the Ig-producing, CD5-expressing clones elaborated mAbs reactive with the autoantigens tested, greater than 50% did. It is possible that with a broader autoantigenic panel or with larger quantities of CLL/DWDL-derived Ig, even more autoantibody-producing clones might be identified. These studies may have important implications for the antigenic specificity of subsets of human B lymphocytes as well as for lymphoproliferative and autoimmune disorders in general.

scholarly journals Lactic dehydrogenase in normal and leukemia lymphocyte subpopulations: evidence for the presence of abnormal T cells and B cells in chronic lymphocytic leukemia

Blood ◽  
1981 ◽  
Vol 57 (2) ◽  
pp. 324-327 ◽  
Author(s):  
P Rambotti ◽  
S Davis
Keyword(s):  
T Cells ◽  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
T Lymphocytes ◽  
B Lymphocytes ◽  
Lactic Dehydrogenase ◽  
Isozyme Pattern ◽  
Lymphocyte Subpopulations ◽  
Lymphocytic Leukemia ◽  
Ldh Activity

Abstract Lactic dehydrogenase (LDH) was quantitated and the isozyme pattern studied in lymphocyte subpopulations from normal people and patients with chronic lymphocytic leukemia (CLL). Normal T lymphocytes differed from normal B lymphocytes in having greater total LDH activity (597.2 versus 252.1). Total LDH activity in CLL T cells (347.1) was lower than normal T cells., but not significantly different than normal B cells. Total LDH activity in CLL B cells (124.6) was lower then normal B cells and normal T cells. The isozyme pattern of normal T lymphocytes showed a higher activity in the LDH-1 band (26.7% versus 5.4%) but showed a lower activity in LDH-5 band (4.3% versus 16.3%) compared to normal B cells. Chronic lymphocytic leukemia T cells could be distinguished from CLL B cells by a high LDH-5 band (22.3% versus 7.6%) and from normal T cells by a high LDH-5 band (22.3% versus 4.3%) and a low LDH-1 band (7.3% versus 26.7%). CLL B cells could be distinguished from normal B cells by a low LDH-5 band (7.6% versus 16.3%). Thus, the LDH isozyme pattern distinguishes normal T lymphocytes from normal B lymphocytes, and normal T and B lymphocytes from CLL T and B lymphocytes.

Different Expression of FcgammaRIIb in Chronic Lymphocytic Leukemia and Human Normal B Lymphocytes

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3134-3134
Author(s):  
Carol Moreno ◽  
Rajendra Damle ◽  
Sonia Jansa ◽  
Gerardo Ferrer ◽  
Pau Abrisqueta ◽  
...  
Keyword(s):  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
B Lymphocytes ◽  
Surface Membrane ◽  
Memory B Cells ◽  
Lymphocytic Leukemia ◽  
Cd38 Expression ◽  
B Cell Subsets

Abstract The Fcgamma receptors (FcγRs) are a family of molecules that modulate immune responses. FcγRIIb is an inhibitory FcγR that bears immunoreceptor tyrosine-based inhibitory motifs which transduce inhibitory signals on coligation with the surface membrane Ig of the B-cell antigen receptor (BCR). The role of FcγRIIb in controlling B cell activation through inhibition of BCR signaling has been extensively studied in animal models. Nevertheless, data on FcγRIIb are scant in human normal and neoplastic B cells, this being due to the lack of a specific antibody for human FcγRIIb. Consequently, there is little information on this receptor in chronic lymphocytic leukemia (CLL). Considering the activated nature of CLL cells and the central role of the BCR in the biology of the disease, studies of FcγRs are warranted. We used a novel specific mAb directly conjugated with Alexa 488 fluorophore that solely reacts with the human FcγRIIb (MacroGenics, Inc.) to investigate the receptors expression on CLL and normal human B cells. The study population included 84 patients with CLL and 24 age- and sex-matched controls. FcγRIIb expression was assessed as the mean fluorescence intensity (MFI) of surface membrane staining. In CLL cells, FcγRIIb was measured on CD19+CD5+ cells in combination with CD38, CD49d or CD69. Normal B cells were immunostained for CD19, CD5, IgD and CD38 expression and B cell subsets: naïve (IgD+CD38−), activated (IgD+CD38+) and memory B cells (IgD−CD38−) were studied for their relative expression of FcγRIIb. FcγRIIb expression was found significantly higher in naïve B cells compared to activated and memory B cells [median MFI: 17420 (11960–21180) vs. 11.140 (7899–16970) and 11.830 (6984–17100); p<0.001]. Significant differences were also observed between CD5− and CD5+ normal B cells. In contrast, FcγRIIb expression was lower in CLL cells than in CD5+ and CD5− normal B lymphocytes [median MFI: 6901(1034–42600), 10180 (5856–14820) and 12120 (7776–16040); p<0.05)]. Interestingly, FcγRIIb expression was variable within individual CLL clones, this being higher in CD38+ and CD49d+ cells than in CD38− and CD49d− cells (p<0.05). Furthermore, the highest density of FcγRIIb was observed on those cells which coexpressed CD38 and CD49d. In contrast, no significant differences were observed between FcγRIIb and the expression of the activation antigen CD69. Although CD69 and CD38 expression was significantly higher on unmutated IGHV cases, no correlation was found between FcγRIIb levels and IGHV mutational status. Similarly, there was no correlation between FcγRIIb and other poor prognostic variables such as ZAP-70 (≥20%), CD38 (≥ 30%) or high risk cytogenetics. Nevertheless, cases with ≥ 30% CD49d+ cells had higher FcγRIIb expression than those with <30% CD49d+ cells (p=0.006). The findings presented in this study suggest a hierarchy of FcγRIIb expression in normal B-cells, CLL cells and their subpopulations: circulating normal CD5− B cells > circulating normal CD5+ B cells > circulating CD5+ CLL B cells. In addition, although FcγRIIb is present on all normal B cell subsets its expression is higher in naïve B cells. Furthermore, in CLL FcγRIIb density is greater in CD38+ and CD49d+ cells within the clone. Although CD49d and FcγRIIb on CLL clones is linked in a direct manner, there is no relationship with FcγRIIb density and IGHV mutations, ZAP-70, CD38 and unfavorable cytogenetic markers. Finally, the relationship between FcγRIIb expression on CLL cells and functional responses to BCR and other receptor-mediated signals deserve further investigation.

scholarly journals Comprehensive Profiling of the Epitranscriptomic N6-Methyladenosine RNA Methylation in Chronic Lymphocytic Leukemia

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 17-18
Author(s):  
Ya Zhang ◽  
Xinting Hu ◽  
Hongzhi Xu ◽  
Ying Li ◽  
Lingyan Zhang ◽  
...  
Keyword(s):  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
De Novo ◽  
Conflicts Of Interest ◽  
R Package ◽  
Methylation Pattern ◽  
Lymphocytic Leukemia ◽  
Functional Enrichment ◽  
Read Length ◽  
Rna Methylation

Introduction N6-methyladenosine (m6A) is the most prevalent post-transcriptional modification of eukaryotic mRNA. Accumulating evidence suggests that RNA m6A methylation exerts crucial roles in oncogenesis. However, the mRNA m6A methylation pattern in chronic lymphocytic leukemia (CLL) has not been investigated. Hence, the aim of this study is to perform a comprehensive profiling to identify distinct m6A methylation signatures in CLL patients. Methods Peripheral blood samples from de novo CLL patients were collected with informed consents at the Department of Hematology in Shandong Provincial Hospital Affiliated to Shandong First Medical University. CD19+ B cells were isolated with informed consents from healthy donors. Methylated RNA immunoprecipitation sequencing (MeRIP-Seq) was conduct to profile mRNA m6A methylation of CLL-B cells and normal CD19+ B cells at Novogene (Beijing, China). The library preparations were sequenced on an Illumina Novaseq platform with a paired-end read length of 150 bp according to the standard protocols. The sequencing was carried out with 3 independent biological replicates. After mapping reads to the reference genome, exomePeak R package was used for the m6A peak identification in each anti-m6A immunoprecipitation group with the corresponding input samples serving as a control, and q-value threshold of enrichment of 0.05 was used for all data sets. The m6A-enriched motifs of each group were identified by HOMER. Differential peak calling was performed using exomePeak R package with parameters of p-value < 0.05 and fold_change > 1. Functional enrichment analyses of gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) of differentiated peaks associated genes were performed. All investigators comply with the guiding principles for experimental procedures found in the Declaration of Helsinki of the World Medical Association. Results By MeRIP sequencing, significant distribution of methylation peaks were detected in 5'UTR, 3'UTR and CDS regions of CLL primary cells (Figure 1A) and normal B cells (Figure 1B). Figure 1C-D illustrated the percentage of methylation peaks in the five regions, suggesting distinct m6A patterns in CLL cells. Moreover, Figure 1E-F revealed the positions of m6A methylation peaks in chromosomes of CLL and normal B cells. Furthermore, the compared distributions of m6A methylation peaks in CLL and normal B cells were presented in Figure 2A. Besides, the bean plot visibly displayed the obvious differentiation of methylation peaks in CLL group and normal B cells in read density (Figure 2B). Importantly, a total of 1836 significantly changed peaks, of which 1519 were significantly up-regulated and 317 peaks were significantly down-regulated (p<0.05, |log2Foldchange|>1; Figure 2C). These m6A peaks were located across 1850 genes. Functional enrichment analyses identified that differentiated peaks associated genes were potentially regulate RNA metabolic process via oncogenic pathways in CLL pathogenesis (Figure 3A-B). In addition, HOMER analysis identified 38 significant de novo m6A peak motifs, top 10 most significant peak motifs of which were presented (Figure 3C), illuminating potential detailed mechanism of m6A RNA methylation in the tumorigenesis and progression of CLL. Conclusion Taken together, our investigations explored for the first time the m6A methylation pattern of mRNA in CLL. m6A modifications play crucial roles in the progression and survival of CLL patients,highlighting m6A modifications-targeted intervention formulating a novel treatment paradigm in progressed CLL that warrants clinical investigation. Disclosures No relevant conflicts of interest to declare.

scholarly journals Lysis of malignant B cells from patients with B-chronic lymphocytic leukemia by autologous T cells activated with CD3 x CD19 bispecific antibodies in combination with bivalent CD28 antibodies

Blood ◽  
1993 ◽  
Vol 82 (6) ◽  
pp. 1803-1812 ◽  
Author(s):  
H Bohlen ◽  
T Hopff ◽  
O Manzke ◽  
A Engert ◽  
D Kube ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
T Cell Activation ◽  
Cell Activation ◽  
Lymphocytic Leukemia ◽  
Bispecific Antibodies ◽  
Autologous Tumor ◽  
Activation Markers

Abstract Bispecific antibodies (bi-MABs) can be used to target T cells to autologous tumor cells. It has been shown that the activation of resting human T cells requires two independent signals, namely the cross-linking of the T-cell receptor (TCR)-CD3 complex together with the CD28 homodimer. In the present study, we demonstrate the activation of T cells from patients with chronic lymphocytic leukemia (CLL) using bi-MABs against the CD3 and CD19 antigens (CD3 x CD19) in combination with monospecific, bivalent antibodies against the CD28 antigen. Mononuclear cells from patients with CLL were cultured with the bi-MAB CD3 x CD19 and monospecific CD28 antibodies. The CD3 x CD19 bi-MABs were isolated by the hybridoma-hybridoma fusion technique and purified by hydrophobic interaction chromatography. T-Cell activation as demonstrated by increased proliferation, upregulation of T-cell activation markers (CD25, CD38), and cytotoxicity against autologous CLL cells and allogeneic B cells was shown in seven of eight CLL specimens. The stimulation with CD3 x CD19 bi-MABs with CD28 antibodies preferentially induced proliferation of CD4+ T cells. The effective dose of purified antibodies required for optimal T-cell activation was 100 ng/mL in vitro, which suggests that this antibody combination may be useful for immunotherapy of patients with B-CLL.

scholarly journals Immunoglobulin secretory function of B cells from untreated patients with chronic lymphocytic leukemia and hypogammaglobulinemia: role of T cells

Blood ◽  
1983 ◽  
Vol 62 (4) ◽  
pp. 767-774 ◽  
Author(s):  
LA Fernandez ◽  
JM MacSween ◽  
GR Langley
Keyword(s):  
T Cells ◽  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
B Lymphocytes ◽  
Peripheral Blood ◽  
Cell Function ◽  
Lymphocytic Leukemia ◽  
Suppressor Activity ◽  
Normal Peripheral Blood

Abstract The mechanism of the hypogammaglobulinemia in patients with chronic lymphocytic leukemia (CLL) was studied by determining the generation of specific immunoglobulin-secreting cells in response to mitogen and antigen stimulation in culture. Normal peripheral blood B lymphocytes from 18 normal subjects cocultured with equal numbers of autologous T cells generated cells secreting 2,542 +/- 695 IgG, 2,153 +/- 615 IgA, and 2,918 +/- 945 IgM. Normal B lymphocytes cocultured with normal allogeneic T cells generated similar numbers. However, B lymphocytes from patients with chronic lymphocytic leukemia cocultured with T cells from the same patient generated only 0.5% as many cells secreting IgG and 11% and 23% as many secreting IgA and IgM, respectively. The reason for this markedly defective generation of immunoglobulin-secreting cells was investigated by evaluating T-helper, T-suppressor, and B-cell function using B cells from tonsil and T and B cells from peripheral blood of normal and leukemic individuals. T cells from patients with chronic lymphocytic leukemia provided somewhat greater help than did normal T cells to normal peripheral blood B cells and normal help to tonsil B cells, whether stimulated with mitogen or antigen. T cells from patients with chronic lymphocytic leukemia did not demonstrate increased suppressor function compared to normals with B cells from normal peripheral blood. The hypogammaglobulinemia in these patients therefore was associated with a markedly defective generation of immunoglobulin secreting cells, and as there was normal or increased T- cell helper activity without excessive suppressor activity, it seems likely that this was due to an intrinsic B-cell defect.

scholarly journals Expression of myelomonocytic antigens on chronic lymphocytic leukemia B cells correlates with their ability to produce interleukin 1

Blood ◽  
1987 ◽  
Vol 70 (6) ◽  
pp. 1750-1757 ◽  
Author(s):  
F Morabito ◽  
EF Prasthofer ◽  
NE Dunlap ◽  
CE Grossi ◽  
AB Tilden
Keyword(s):  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
B Lymphocytes ◽  
Mononuclear Cells ◽  
Gradient Centrifugation ◽  
Interleukin 1 ◽  
Fluorescent Microscopy ◽  
Antigen Expression ◽  
Lymphocytic Leukemia ◽  
Percoll Density Gradient Centrifugation

Abstract We analyzed the expression of myelomonocytic-associated antigens on lymphocytes from B cell chronic lymphocytic leukemia (B-CLL) patients. Blood mononuclear cells were depleted of monocytes by one-step Percoll density gradient centrifugation and tested for antigen expression by fluorescent microscopy and flow cytometry. The reactivity of patient lymphocytes was as follows: 26 of 31 were positive for CD14 (Myr), 22 of 31 for a monocyte Fc receptor (MFC-1), 22 of 31 for CD11b (C3bi receptor), eight of 31 for CD15 (Leu-M1), five of 18 for CD13 (My 7), seven of 18 for My 9, and five of 30 for Mo 2. The B lymphocytes of B- CLL patients were also tested for the ability to produce interleukin 1 (IL-1) after depletion of monocytes and T lymphocytes. In 13 of 17 cases, B lymphocytes of patients produced IL-1 as detected in a mouse thymocyte proliferation assay and, in selected cases, a radioimmunoassay specific for IL-1 beta. The 13 cases that produced IL- 1 were also positive for the expression of one or more myelomonocytic- associated antigens, whereas the four cases that did not produce IL-1 lacked expression of these antigens. In conclusion, the malignant B cells of B-CLL patients frequently express a variety of antigens generally considered specific for myelomonocytic cells, and expression of these antigens is associated with the ability to produce IL-1.

scholarly journals Analysis of signal transduction in B chronic lymphocytic leukemia cells

Blood ◽  
1988 ◽  
Vol 71 (5) ◽  
pp. 1461-1469
Author(s):  
HG Drexler ◽  
MK Brenner ◽  
E Coustan-Smith ◽  
SM Gignac ◽  
AV Hoffbrand
Keyword(s):  
Signal Transduction ◽  
Protein Kinase C ◽  
B Cells ◽  
Protein Kinase ◽  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
B Lymphocytes ◽  
Lymphocytic Leukemia ◽  
Receptor Expression ◽  
Kinase C

We report here experiments on the analysis of cellular signal transduction in a series of patients with chronic B cell disorders (B cell chronic lymphocytic leukemia [B-CLL] and prolymphocytic leukemia). We compared the response of the leukemic cells with primary external signals (interleukin 2 [IL-2] or B cell differentiation factors [BCDF or IL-6]) with their response to secondary inducers (the phorbol ester (12–O-tetradecanoylphorbol-13-acetate [TPA] or the calcium ionophore A23187) that circumvent the first part of the signal transduction pathway by directly activating the key enzyme protein kinase C. One BCDF was synthesized by mitogen-activated peripheral blood B lymphocytes; a second BCDF was constitutively produced by the human bladder carcinoma cell line T24. Changes in morphology, Tac (IL-2 receptor) expression, RNA synthesis measured by 3H-uridine uptake, and immunoglobulin production tested by enzyme-linked immunosorbent assay were used as parameters of successful signal transduction. TPA alone and TPA plus A23187 (synergistically) effectively initiated differentiation in all the leukemia cases. Neither IL-2 nor BCDF (singly or in combinations) caused equivalent responses. On the other hand, IL-2 and BCDF produced a substantial differentiation effect on normal B lymphocytes. Our data suggest that (a) B-CLL cells are able to respond to direct stimulation of the second messenger pathway (through protein kinase C) but not to the physiological stimuli IL-2 or BCDF; (b) the defect in signal transduction appears to be located upstream of protein kinase C (a possible candidate is a G protein); (c) malignant B cells may spontaneously or after treatment with inducers express the IL- 2 receptor (Tac antigen) in the absence of a functional differentiating response to IL-2; and (d) signs of proliferation/differentiation in B- CLL samples after incubation with IL-2 or BCDF might be due to contamination of the cell populations with residual normal B cells.

scholarly journals Expression of FAK and Its Involvement in the Progression of B-Cell Chronic Lymphocytic Leukemia

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3309-3309
Author(s):  
Cristina Gattazzo ◽  
Andrea Visentin ◽  
Alberto Pavan ◽  
Veronica Martini ◽  
Federica Frezzato ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
B Lymphocytes ◽  
Focal Adhesion ◽  
Poor Prognosis ◽  
Lymphocytic Leukemia ◽  
Bcr Signaling ◽  
Cell Chronic Lymphocytic Leukemia

Abstract INTRODUCTION B-cell chronic lymphocytic leukemia (B-CLL) is a disorder characterized by the accumulation of clonal CD5+ B lymphocytes, due to uncontrolled growth and resistance to apoptosis. Although the prognosis and clinical outcome has dramatically improved by recent innovative therapies, B-CLL still remains an incurable disease. Since signaling events downstream the BCR engagement are important for the progression of B cells, BCR signaling has been investigated in B-CLL in order to design new agents to specifically treat this disease. We demonstrated that Lyn, one of the first kinases involved in BCR signaling pathway, is overexpressed, constitutively active and anomalously distributed in malignant B cells, as compared to normal B lymphocytes. The Focal adhesion kinase (FAK), a non-receptor protein tyrosine kinase, is the primary enzyme involved in the engagement of integrins and assembly of Focal Adhesion. FAK is regulated primarily through tyrosine phosphorylation by Lyn after BCR engagement and was found to be overexpressed in many kinds of human cancers. However, a downmodulation of FAK expression and its association to poor prognosis have also been reported. The aim of this study was to investigate the role of FAK in CLL patients. METHODS Blood samples were collected from 5 controls and 50 B-CLL patients. Informed consent was obtained according to the Declaration of Helsinki. Untouched peripheral blood B cells were purified using the RosetteSep for human B cells isolation kit. The samples that were used had at least 95% of normal CD19+ or neoplastic CD5+/CD19+ cells, as assessed by flow-cytometry. Level of FAK protein was evaluated by Western blotting (Wb) and Flow Cytometry assay (FC). Levels of FAK were correlated to clinical parameters of patients. RESULTS We observed that FAK was downmodulated in 56% of analyzed patients with respect to healthy subjects (respectively, Wb: 0.28±0.25 vs 0.85±0.32, p<0.001; FC: 35%±29 vs 60%±16, p<0.05). We also identified that lower levels of FAK expression were related to the prognostic markers of poor outcome (the expression of ZAP70, CD38 and an unmutated-IGHV genes status, p<0.05) and to a shorter Treatment Free Survival (p<0.05). Moreover, patients (n=6) who had an indolent course and were responsive to the standard treatment, showed normal expression of this kinase already at diagnosis. In contrast, patients (n=6) with a more aggressive disease, had a lower expression of FAK, that was further downmodulated during the progression of disease, irrespective of how the patients were treated. CONCLUSIONS From the data presented in this report we propose that FAK downmodulation could be considered as a new marker of poor prognosis and as a putative predictor for high-risk subgroups of CLL, even in early-stage disease. Disclosures No relevant conflicts of interest to declare.

Remarkable Differences in Cellular Activation State and Migratory and Proliferative Potential among Clonal Cells Derived from Different Tissues of Chronic Lymphocytic Leukemia Patients.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2817-2817
Author(s):  
Rajendra N. Damle ◽  
Taraneh Banapour ◽  
Sonal Temburni ◽  
Tarun Wasil ◽  
Jonathan E. Kolitz ◽  
...  
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
Telomere Length ◽  
Telomerase Activity ◽  
Lymphocytic Leukemia ◽  
Proliferative Potential ◽  
Activation Markers ◽  
Cellular Activation ◽  
Cd38 Expression

Abstract An antigen-independent process that takes place in the bone marrow (BM) leads to the birth of B cells from bone marrow precursors. Cross-talk between components of the microenvironment of BM or secondary lymphoid compartment(s), eg. spleen (SP), nurtures the subsequent evolution of B cells and governs in large part the natural history of normal B cells and B cell malignancies including chronic lymphocytic leukemia (B-CLL). Interaction of B cells with stromal elements confers upon them features enabling their transient sequestration, proliferation and extended survival. In this report we have compared the characteristics of clonal B-CLL cells obtained from paired specimens (peripheral blood, PB with corresponding BM or SP obtained within an interval of less than 1 month of each other) from 17 individual untreated B-CLL patients. These cells were tested by surface immunofluorescence and flow cytometry for their expression of a panel of chemokine receptors (CCR −1, −2, −4, and −7 and CXCR−1, −2, −3, and −4) and markers of cellular activation (CD23, CD62L, CD69, CD71 and HLA-DR). The relative age of the B cells (telomere length) and their ability to maintain telomere length (telomerase activity) were studied in paired BM/SP and PB samples from 15 of these cases. Although PB-, BM- and SP-derived B cells expressed activation markers, specifically, the percentages of cells expressing ZAP-70 and Ki-67 were significantly higher in BM- and SP-derived B cells than those expressed by corresponding PB-derived B cells (p<0.01). Increase in extent of CD38-positivity among members of the clone correlates with poor prognosis in B-CLL. Interestingly, in cases with low CD38 expression (<30% cells expressing CD38), the percentage of B-CLL cells expressing CXCR3 and CCR7 was significantly higher among PB-B cells, than BM/SP-derived B cells. No such differences existed in cases with high CD38 expression. This suggests a role for these receptors and their ligands in maintaining homeostasis of B-CLL cells in this subset of cases (that does not show remarkable progression of disease). In each of the 15 cases studied BM and SP-B cells had significantly higher telomerase activity (p<0.01) than those in PB, although telomere lengths of B cells from both sources were comparable. These findings highlight important differences in cellular kinetics among lymphoid compartments in B-CLL.

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