scholarly journals The malignant B cells from B-chronic lymphocytic leukemia patients release TAC-soluble interleukin-2 receptors

Blood ◽  
1988 ◽  
Vol 72 (2) ◽  
pp. 447-450 ◽  
Author(s):  
NE Kay ◽  
J Burton ◽  
D Wagner ◽  
DL Nelson

Abstract Both membrane (p55) and soluble (p45) forms of TAC-reactive interleukin- 2 receptor (IL-2R) are expressed and/or released by activated lymphocytes or monocytes. Previous work has detected increased levels of circulating, TAC-soluble IL-2R (soluble TAC antigen) in the serum of most B-cell chronic lymphocytic leukemia (B-CLL) patients. We detected soluble TAC antigen in B-CLL patients (mean of 3,332 U/mL v 410 for controls). Serum soluble TAC antigen levels increased with stage (mean value of 1,187 U/mL for stage 0 v 2,527 for stage 2 and 5,410 for stages 3 and 4). We next attempted to determine whether the elevated serum levels of soluble TAC antigen in B-CLL patients might result from shedding or secretion of the receptor from the circulating, malignant B cells. Purified, malignant B cells from B-CLL patients were capable of producing easily detectable soluble TAC antigen after 48 hours of in vitro culture (range of 60 to 1,563 U/mL). IL-2R production by CLL B cells was dose dependent in most patients over a concentration of 10 x 10(6) to 60 x 10(6)/mL. In contrast, there was little or no detectable soluble TAC antigen when highly purified T cells from the same patients were cultured. Finally, despite elaboration of soluble IL-2R by CLL B cells, membrane expression of B-cell IL-2R was detected in only six of 11 patients. Thus, the cellular source of the elevated serum IL-2R levels is the malignant CLL B cell. Taken together these data suggest that (a) the malignant CLL B cell is “activated” in terms of release of soluble IL-2R and may serve as a tumor marker in this disease and (b) the elevated levels of circulating IL-2R may be an associated factor in the cellular immunodeficiency noted in B-CLL patients.

Blood ◽  
1988 ◽  
Vol 72 (2) ◽  
pp. 447-450 ◽  
Author(s):  
NE Kay ◽  
J Burton ◽  
D Wagner ◽  
DL Nelson

Both membrane (p55) and soluble (p45) forms of TAC-reactive interleukin- 2 receptor (IL-2R) are expressed and/or released by activated lymphocytes or monocytes. Previous work has detected increased levels of circulating, TAC-soluble IL-2R (soluble TAC antigen) in the serum of most B-cell chronic lymphocytic leukemia (B-CLL) patients. We detected soluble TAC antigen in B-CLL patients (mean of 3,332 U/mL v 410 for controls). Serum soluble TAC antigen levels increased with stage (mean value of 1,187 U/mL for stage 0 v 2,527 for stage 2 and 5,410 for stages 3 and 4). We next attempted to determine whether the elevated serum levels of soluble TAC antigen in B-CLL patients might result from shedding or secretion of the receptor from the circulating, malignant B cells. Purified, malignant B cells from B-CLL patients were capable of producing easily detectable soluble TAC antigen after 48 hours of in vitro culture (range of 60 to 1,563 U/mL). IL-2R production by CLL B cells was dose dependent in most patients over a concentration of 10 x 10(6) to 60 x 10(6)/mL. In contrast, there was little or no detectable soluble TAC antigen when highly purified T cells from the same patients were cultured. Finally, despite elaboration of soluble IL-2R by CLL B cells, membrane expression of B-cell IL-2R was detected in only six of 11 patients. Thus, the cellular source of the elevated serum IL-2R levels is the malignant CLL B cell. Taken together these data suggest that (a) the malignant CLL B cell is “activated” in terms of release of soluble IL-2R and may serve as a tumor marker in this disease and (b) the elevated levels of circulating IL-2R may be an associated factor in the cellular immunodeficiency noted in B-CLL patients.


Blood ◽  
1987 ◽  
Vol 70 (2) ◽  
pp. 418-427
Author(s):  
AS Freedman ◽  
AW Boyd ◽  
FR Bieber ◽  
J Daley ◽  
K Rosen ◽  
...  

In an attempt to compare B cell chronic lymphocytic leukemia (B-CLL) with its normal cellular counterpart, the cell surface phenotype of 100 cases of B-CLL was determined by using a panel of monoclonal antibodies (MoAbs) directed against B cell-restricted and -associated antigens. The majority of B-CLL cells expressed Ia, B4 (CD19), B1 (CD20), B2 (CD21), surface immunoglobulin (sIg), and T1 (CD5) but lacked C3b (CD35) receptors. In contrast, the overwhelming majority of small unstimulated B cells expressed Ia, B4, B1, B2, sIg, and C3b receptors but lacked detectable T1. Small numbers of weakly sIg+ cells could be identified in peripheral blood and tonsil that coexpressed the B1 and T1 antigens. Approximately 16% of fetal splenocytes coexpressed B1, T1, weak sIg, B2, and Ia but lacked C3b receptors and therefore closely resembled most B-CLL cells. With the phenotypic differences between the majority of small unstimulated B cells and B-CLL cells, we examined normal in vitro activated B cells and B-CLL cells for the expression of B cell-restricted and -associated activation antigens. Of 20 cases examined, virtually all expressed B5, and approximately 50% of the cases expressed interleukin-2 receptors (IL-2R) and Blast-1. Normal B cells were activated with either anti-Ig or 12–0-tetradecanoylphorbol- beta-acetate (TPA) and then were examined for coexpression of B1, T1, and the B cell activation antigens B5 and IL-2R. Only cells activated with TPA coexpressed B1 and T1 as well as B5 and IL-2R. B cells activated with either anti-Ig or TPA proliferated in the presence of IL- 2, whereas B-CLL cells did not, although they all expressed the identical 60-kilodalton proteins by immunoprecipitation. These studies are consistent with the notion that B-CLL resembles several minor subpopulations of normal B cells including a population of B cells that are activated in vitro directly through the protein kinase C pathway.


Blood ◽  
1987 ◽  
Vol 70 (2) ◽  
pp. 418-427 ◽  
Author(s):  
AS Freedman ◽  
AW Boyd ◽  
FR Bieber ◽  
J Daley ◽  
K Rosen ◽  
...  

Abstract In an attempt to compare B cell chronic lymphocytic leukemia (B-CLL) with its normal cellular counterpart, the cell surface phenotype of 100 cases of B-CLL was determined by using a panel of monoclonal antibodies (MoAbs) directed against B cell-restricted and -associated antigens. The majority of B-CLL cells expressed Ia, B4 (CD19), B1 (CD20), B2 (CD21), surface immunoglobulin (sIg), and T1 (CD5) but lacked C3b (CD35) receptors. In contrast, the overwhelming majority of small unstimulated B cells expressed Ia, B4, B1, B2, sIg, and C3b receptors but lacked detectable T1. Small numbers of weakly sIg+ cells could be identified in peripheral blood and tonsil that coexpressed the B1 and T1 antigens. Approximately 16% of fetal splenocytes coexpressed B1, T1, weak sIg, B2, and Ia but lacked C3b receptors and therefore closely resembled most B-CLL cells. With the phenotypic differences between the majority of small unstimulated B cells and B-CLL cells, we examined normal in vitro activated B cells and B-CLL cells for the expression of B cell-restricted and -associated activation antigens. Of 20 cases examined, virtually all expressed B5, and approximately 50% of the cases expressed interleukin-2 receptors (IL-2R) and Blast-1. Normal B cells were activated with either anti-Ig or 12–0-tetradecanoylphorbol- beta-acetate (TPA) and then were examined for coexpression of B1, T1, and the B cell activation antigens B5 and IL-2R. Only cells activated with TPA coexpressed B1 and T1 as well as B5 and IL-2R. B cells activated with either anti-Ig or TPA proliferated in the presence of IL- 2, whereas B-CLL cells did not, although they all expressed the identical 60-kilodalton proteins by immunoprecipitation. These studies are consistent with the notion that B-CLL resembles several minor subpopulations of normal B cells including a population of B cells that are activated in vitro directly through the protein kinase C pathway.


Blood ◽  
1988 ◽  
Vol 71 (4) ◽  
pp. 1012-1020 ◽  
Author(s):  
JS Moore ◽  
MB Prystowsky ◽  
RG Hoover ◽  
EC Besa ◽  
PC Nowell

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.


Blood ◽  
2002 ◽  
Vol 100 (8) ◽  
pp. 2973-2979 ◽  
Author(s):  
Anne J. Novak ◽  
Richard J. Bram ◽  
Neil E. Kay ◽  
Diane F. Jelinek

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.


Blood ◽  
2007 ◽  
Vol 110 (9) ◽  
pp. 3316-3325 ◽  
Author(s):  
Andrea Bürkle ◽  
Matthias Niedermeier ◽  
Annette Schmitt-Gräff ◽  
William G. Wierda ◽  
Michael J. Keating ◽  
...  

Abstract CXCL13 is a homeostatic chemokine for lymphocyte homing and positioning within follicles of secondary lymphoid tissues, acting through its cognate receptor, CXCR5. Moreover, the CXCR5-CXCL13 axis plays a unique role in trafficking and homing of B1 cells. Here, we report that chronic lymphocytic leukemia (CLL) B cells express high levels of functional CXCR5. CXCR5 expression levels were similar on CLL B cells and normal CD5+ B cells, and higher compared with normal CD5− B cells, follicular B-helper T cells (TFH cells), or neoplastic B cells from other B-cell neoplasias. Stimulation of CLL cells with CXCL13 induces actin polymerization, CXCR5 endocytosis, chemotaxis, and prolonged activation of p44/42 mitogen-activated protein kinases. Anti-CXCR5 antibodies, pertussis toxin, and wortmannin inhibited chemotaxis to CXCL13, demonstrating the importance of Gi proteins and PI3 kinases for CXCR5 signaling. Moreover, CLL patients had significantly higher CXCL13 serum levels than volunteers, and CXCL13 levels correlated with β2 microglobulin. We detected CXCL13 mRNA expression by nurselike cells, and high levels of CXCL13 protein in supernatants of CLL nurselike cell cultures. By immunohistochemistry, we detected CXCL13+ expression by CD68+ macrophages in situ within CLL lymph nodes. These data suggest that CXCR5 plays a role in CLL cell positioning and cognate interactions between CLL and CXCL13-secreting CD68+ accessory cells in lymphoid tissues.


Blood ◽  
1987 ◽  
Vol 69 (6) ◽  
pp. 1667-1673 ◽  
Author(s):  
I Touw ◽  
L Dorssers ◽  
B Lowenberg

Abstract To determine the growth properties of B cell chronic lymphocytic leukemia (B CLL) and to identify possible abnormalities thereof, we examined the in vitro action of interleukin 2 (IL2) in four patients. Using radiolabeled IL2 and monoclonal antibodies reactive with IL2 membrane receptors we show that CLL cells, after their activation in vitro, express IL2 receptors of a high- as well as a low-affinity type, exactly as has been reported for normal T and B blasts. In three of the four reported cases, CLL proliferation (measured with 3H-thymidine incorporation) depended on the addition of phytohemagglutinin (PHA) to activate the cells and IL2 (optimal concentration, 10 to 100 U IL2/mL). In contrast, the cells of the fourth case of CLL (CLL-4) proliferated in an autonomous fashion, ie, without a need for PHA and IL2 in culture. Specific blocking of the IL2-binding sites with anti-IL2 receptor monoclonal antibodies almost completely inhibited the proliferation of these cells, which indicated that functional IL2 receptors were required for the autonomous proliferation. The demonstration of low concentrations of IL2 activity in the culture medium conditioned by the cells suggests that endogenous IL2 had been responsible for the spontaneous 3H-thymidine uptake by the CLL cells of patient 4. However, we were unable to extract IL2 mRNA from the cells (neither fresh nor after various in vitro incubations) in quantities detectable by Northern blot analysis that would prove that the CLL cells of patient 4 were actively synthesizing IL2 during culture. Thus, individual cases of B CLL are subject to variable growth regulation involving functional IL2 receptors on the cell surface: after activation with PHA the cells respond to exogenous IL2 in a fashion similar to normal B lymphocytes, or the cells are stimulated by endogenous IL2 (or an IL2-like activity) and do not require activation with PHA.


Blood ◽  
1997 ◽  
Vol 89 (3) ◽  
pp. 941-947 ◽  
Author(s):  
Raymond S. Douglas ◽  
Renold J. Capocasale ◽  
Roberta J. Lamb ◽  
Peter C. Nowell ◽  
Jonni S. Moore

Abstract Chronic lymphocytic leukemia (CLL) is the most common leukemia of the western world and is characterized by a slowly progressing accumulation of clonal CD5+ B cells. Our laboratory has investigated the role of transforming growth factor-β (TGF-β) and interleukin-4 (IL-4) in the pathogenesis of B-cell expansion in CLL. In vitro addition of TGF-β did not increase spontaneous apoptosis of B cells from most CLL patients, as determined using the TUNEL method, compared with a twofold increase observed in cultures of normal B cells. There was similar expression of TGF-β type II receptors on both CLL B cells and normal B cells. In contrast to apoptosis, CLL B-cell proliferation was variably inhibited with addition of TGF-β. In vitro addition of IL-4, previously reported to promote CLL B-cell survival, dramatically reduced spontaneous apoptosis of CLL B cells compared with normal B cells. CLL B-cell expression of IL-4 receptors was increased compared to normal B cells. Thus, our results show aberrant apoptotic responses of CLL B cells to TGF-β and IL-4, perhaps contributing to the relative expansion of the neoplastic clone.


Blood ◽  
1996 ◽  
Vol 87 (3) ◽  
pp. 1022-1029 ◽  
Author(s):  
N Chaouchi ◽  
C Wallon ◽  
C Goujard ◽  
G Tertian ◽  
A Rudent ◽  
...  

Human interleukin-13 (IL-13) acts at different stages of the normal B- cell maturation pathway with a spectrum of biologic activities overlapping those of IL-4. B chronic lymphocytic leukemia (B-CLL) is characterized by the accumulation of slow-dividing and long-lived monoclonal B cells, arrested at the intermediate stage of their differentiation. In vitro, B-CLL cells exhibit a spontaneous apoptosis regulated by different cytokines. In this report, we show that IL-13 (10 to 200 ng/mL) acts directly on monoclonal B-CLL cells from 12 patients. (1) IL-13 enhances CD23 expression and induces soluble CD23 secretion by B-CLL cells but does not exhibit a growth factor activity. (2) IL-13 inhibits IL-2 responsiveness of B-CLL cells, activated either with IL-2 alone or through crosslinking of lgs or ligation of CD40 antigen. (3) IL-13 protects B-CLL cells from in vitro spontaneous apoptosis. The effects of IL-13 on neoplasic B cells were slightly less than those of IL-4 and occurred independently of the presence of IL-4. The present observations show that IL-13 may exhibit a negative regulatory effect on neoplasic B cells in contrast with that observed in normal B cells, and suggest that IL-13 could be an important factor in the pathogenesis of CLL by preventing the death of monoclonal B cells. Moreover, B-CLL may be an interesting model to study the regulation of the expression of IL-13 receptor and/or signal transduction pathways.


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