apyrase and Leukemia--Lymphocytic--Chronic--B-Cell

Chronic lymphocytic leukemia is one of the commonest leukemias affecting adults. CD39 inhibits T-cell and Natural killer (NK) cell responses by hydrolyzing adenosine triphosphate and adenosine diphosphate, suppressing the immune system. We investigated expression of CD39 on CD4+ T Lymphocytes in chronic lymphocytic leukemia (CLL) patients and its relationship with deletion 6q, its association with disease stage and survival.. Thirty CLL patients and 20 matched controls were included in the study. Bone marrow studies with immunophenotyping, CD39, CD38, and ZAP-70, and detection of del 6q by FISH were performed.. CD39+ CD4+ T helper cells in CLL patients were significantly expressed compared with the controls (p < .001). Levels of CD39+ CD4+ T cells were significantly expressed in high risk CLL patients. Del 6q was detected in 63.3% of patients and it correlated with CD39, CD38, and ZAP-70, and advanced stage disease. There was a significant relation between response to treatment and CD39 expression and del 6q, also there was a significant difference in overall survival (OS) between patients with and without Del 6q.. CD39 expression on CD4+ Tcells and del 6q act as prognostic markers in CLL. Blocking or inhibition of CD39 may be a target for new immune therapy for CLL.

Topics: Adult; Aged; Aged, 80 and over; Apyrase; CD4-Positive T-Lymphocytes; Chromosome Deletion; Chromosomes, Human, Pair 6; Female; Gene Expression Regulation, Neoplastic; Humans; Leukemia, Lymphocytic, Chronic, B-Cell; Male; Middle Aged; Neoplasm Proteins; Prospective Studies

Numerous prognostic markers were introduced to screen for patients with B-cell chronic lymphocytic leukemia (B-CLL) likely to have a progressive course, bearing the potential to facilitate risk-adapted treatment strategies. Extracellular adenosine triphosphate (ATP) functions as a "natural adjuvant" that boosts immune response in the tumor microenvironment. Ectonucleoside triphosphate diphosphohydrolase-1 (CD39/ENTPD1) is the ectonucleotidase that catalyzes the hydrolysis of ATP. The present study was conducted to analyze CD39 expression in T cells and B-CLL cells to evaluate its impact on the clinical course of patients with B-CLL and correlate its levels with well-established risk factors. T-cell CD39 expression was significantly increased in patients' peripheral blood compared to healthy controls. The higher levels were associated with advanced stages of disease and negatively interacted with time to first treatment. Overall, our data indicate that T-cell CD39 expression may identify subsets of patients with B-CLL with an unfavorable clinical outcome. Moreover, it can be incorporated into prognostic schema to improve the prediction of CLL disease progression.

Topics: Aged; Antigens, CD; Antigens, Surface; Apyrase; B-Lymphocytes; Biomarkers, Tumor; Chromosome Aberrations; Disease Progression; Female; Humans; Immunophenotyping; Leukemia, Lymphocytic, Chronic, B-Cell; Male; Middle Aged; Neoplasm Staging; Prognosis; T-Lymphocytes

Chronic lymphocytic leukemia (CLL) cells depend on their microenvironment for proliferation and survival. Ectonucleotidase CD39 has anti-inflammatory properties as it hydrolyzes proinflammatory extracellular ATP, generates anti-inflammatory adenosine, and also protects regulatory T cells from ATP-induced cell death. In this study, we investigated the clinical significance of CD39 expression on CD4(+) T cells in 62 patients with CLL as well as its compartmental regulation and explored the possible mechanisms for its induction. Compared to healthy individuals, CD4(+)CD39(+) lymphocytes were increased in the peripheral blood of patients with CLL and correlated with the advanced stage of disease. CD4(+)CD39(+) cells were also higher in patients with CLL, who needed therapeutic intervention, and in those who had unmutated immunoglobulin heavy chain variable region gene, were ZAP70(+) or had β2-microglobulin levels of >3 g/L. There were more CD4(+)CD39(+) lymphocytes in the bone marrow compartment than in the peripheral blood, and in vitro studies showed that CD39 can be induced on CD4(+) cells by exposure to ATP or indirectly, following B cell receptor engagement. This may support the notion that the leukemic cells contribute to create an immune-subversive environment, and perhaps to a poorer prognosis. CD39(+) may also serve as a future target for the development of novel therapies with immune-modulating antitumor agents in CLL.

Topics: Aged; Antigens, CD; Antigens, Surface; Apyrase; Biomarkers, Tumor; Case-Control Studies; CD4 Lymphocyte Count; CD4-Positive T-Lymphocytes; Disease Progression; Female; Humans; Leukemia, Lymphocytic, Chronic, B-Cell; Male; Middle Aged; Prognosis; Up-Regulation

Chronic lymphocytic leukemia (CLL) is a B-cell disorder, but it is also associated with abnormalities in T-lymphocyte function. In this study we examine changes in T-lymphocyte CD39 and CD73 expression in patients with CLL.. Blood samples were drawn from 34 patients with CLL and 31 controls. The cells were stained for CD3, CD4, CD8, CD19, CD39, and CD73 and analyzed by flow cytometry.. Overall, patients with CLL had a higher percentage of CD39(+) T lymphocytes than did controls. The percentage of cells expressing CD39 was higher in both CD4(+) cells and CD8(+) cells. Higher CD3/CD39 expression was associated with a later disease stage. No correlations between T-lymphocyte CD39 levels and CD38 or Zap-70 expression were observed. In contrast, the percentage of T lymphocytes and B lymphocytes that expressed CD73 was decreased in patients with CLL. Average B-lymphocyte CD73 expression was decreased in CLL because the majority of CLL clones were CD73. However a minority of CLL clones were CD73(+), and patients with CD73(+) clones tended to have earlier stage disease.. T-lymphocyte CD39 and CD73 expression may be useful prognostic markers in patients with CLL. Expression of CD73 on the malignant cell population in CLL may be a marker of better prognosis.

Topics: 5'-Nucleotidase; Antigens, CD; Apyrase; B-Lymphocytes; Flow Cytometry; Humans; Leukemia, Lymphocytic, Chronic, B-Cell; Lymphocyte Count; Prognosis; T-Lymphocyte Subsets; T-Lymphocytes

Extracellular adenosine (ADO), generated from ATP or ADP through the concerted action of the ectoenzymes CD39 and CD73, elicits autocrine and paracrine effects mediated by type 1 purinergic receptors. We have tested whether the expression of CD39 and CD73 by chronic lymphocytic leukemia (CLL) cells activates an adenosinergic axis affecting growth and survival. By immunohistochemistry, CD39 is widely expressed in CLL lymph nodes, whereas CD73 is restricted to proliferation centers. CD73 expression is highest on Ki-67(+) CLL cells, adjacent to T lymphocytes, and is further localized to perivascular areas. CD39(+)/CD73(+) CLL cells generate ADO from ADP in a time- and concentration-dependent manner. In peripheral blood, CD73 expression occurs in 97/299 (32%) CLL patients and pairs with CD38 and ZAP-70 expression. CD73-generated extracellular ADO activates type 1 purinergic A2A receptors that are constitutively expressed by CLL cells and that are further elevated in proliferating neoplastic cells. Activation of the ADO receptors increases cytoplasmic cAMP levels, inhibiting chemotaxis and limiting spontaneous drug-induced apoptosis of CLL cells. These data are consistent with the existence of an autocrine adenosinergic loop, and support engraftment of leukemic cells in growth-favorable niches, while simultaneously protecting from the action of chemotherapeutic agents.

Topics: 5'-Nucleotidase; Adenosine; Adenosine Diphosphate; Adenosine Triphosphate; Antigens, CD; Antineoplastic Agents, Phytogenic; Apyrase; Autocrine Communication; Cell Death; Cell Differentiation; Cell Movement; Cell Survival; Etoposide; Extracellular Space; GPI-Linked Proteins; Humans; Leukemia, Lymphocytic, Chronic, B-Cell; Paracrine Communication; Receptor, Adenosine A2A; Tumor Cells, Cultured

Chronic lymphocytic leukemia (CLL) is characterized by accumulation of mature appearing lymphocytes and is rarely complicated by thrombosis. One possible explanation for the paucity of thrombotic events in these patients may be the presence of the ecto-nucleotidase CD39/NTDPase-1 on the surface of the malignant cells in CLL. CD39 is the major promoter of platelet inhibition in vivo via its metabolism of ADP to AMP. We hypothesize that if CD39 is observed on CLL cells, then patients with CLL may be relatively protected against platelet aggregation and recruitment and that CD39 may have other effects on CLL, including modulation of the disease, via its metabolism of ATP.. Normal and malignant lymphocytes were isolated from whole blood from patients with CLL and healthy volunteers. Enzyme activity was measured via radio-TLC assay and expression via FACS. Semi-quantitative RT-PCR for CD39 splice variants and platelet function tests were performed on several samples.. Functional assays demonstrated that ADPase and ATPase activities were much higher in CLL cells than in total lymphocytes from the normal population on a per cell basis (p-value < 0.00001). CD39 activity was elevated in stage 0-2 CLL compared to stage 3-4 (p < 0.01). FACS of lymphocytes demonstrated CD39 expression on > 90% of normal and malignant B-lymphocytes and approximately 8% of normal T-lymphocytes. RT-PCR showed increased full length CD39 and splice variant 1.5, but decreased variant 1.3 in CLL cells. Platelet function tests showed inhibition of platelet activation and recruitment to ADP by CLL cells.. CD39 is expressed and active on CLL cells. Enzyme activity is higher in earlier stages of CLL and decreased enzyme activity may be associated with worsening disease. These results suggest that CD39 may play a role in the pathogenesis of malignancy and protect CLL patients from thrombotic events.

Topics: Adenosine Diphosphate; Adult; Aged; Aged, 80 and over; Antigens, CD; Apyrase; B-Lymphocytes; Chromatography, Thin Layer; Female; Flow Cytometry; Gene Expression Regulation, Leukemic; Humans; Leukemia, Lymphocytic, Chronic, B-Cell; Lymphocyte Subsets; Male; Middle Aged; Platelet Activation; Platelet Aggregation; Reverse Transcriptase Polymerase Chain Reaction; T-Lymphocytes

Deletions in chromosome bands 11q22-q23 were recently shown to be one of the most frequent chromosome aberrations in B-cell chronic lymphocytic leukemia (B-CLL). Patients suffering from B-CLL with 11q deletion are characterized by extensive lymphadenopathy, rapid disease progression, and short survival times. Phenotypic and functional characteristics of B-CLL cells with 11q deletion that may help to explain the pathophysiology of this entity are yet unknown. In the present study, B-CLL cells with (n = 19) and without (n = 19) 11q deletion were analyzed for their expression of functionally relevant cell surface molecules (n = 57). B-CLL cells with 11q deletion carried significantly lower levels of the adhesion molecules CD11a/CD18 (integrin alphaL/beta2), CD11c/CD18 (integrin alphaX/beta2), CD31 (PECAM-1), CD48, and CD58 (LFA-3). Furthermore, B-CLL cells with 11q deletion expressed less the cell signaling receptors CD45 (leukocyte common antigen [LCA]), CD6, CD35 (complement receptor 1), and CD39. Reduced CD45 levels and low-level expression of CD49d correlated with decreased overall survival. B-CLL cells with or without 11q deletion did not differ in their growth fractions, expression levels of transcription factor NF-kappaB, or their response to mitogenic stimuli. Decreased levels of functionally relevant adhesion molecules and of cell signaling receptors may contribute to the pathogenesis of the subgroup of B-CLL characterized by 11q22-q23 deletion.

Topics: Adenosine Triphosphatases; Antigens, CD; Antigens, Differentiation, T-Lymphocyte; Apyrase; CD11 Antigens; CD18 Antigens; CD48 Antigen; CD58 Antigens; Cell Adhesion Molecules; Chromosomes, Human, Pair 11; Gene Deletion; Humans; Integrin alpha4; Leukemia, Lymphocytic, Chronic, B-Cell; Leukocyte Common Antigens; NF-kappa B; Platelet Endothelial Cell Adhesion Molecule-1; Receptors, Complement 3b; Signal Transduction; Survival Rate