scholarly journals Defective interleukin-2 production and responsiveness by T cells in patients with chronic lymphocytic leukemia of B cell variety

Blood ◽  
1986 ◽  
Vol 67 (2) ◽  
pp. 279-284 ◽  
Author(s):  
O Ayanlar-Batuman ◽  
E Ebert ◽  
SP Hauptman
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Proliferative Response ◽  
Interleukin 2 ◽  
Lymphocytic Leukemia ◽  
T Cell Proliferation ◽  
Activated T Cells

Abstract The present studies were designed to investigate the mechanism(s) of the defective T cell proliferative response to various stimuli in patients with B cell chronic lymphocytic leukemia B-CLL. In 14 patients with advanced B-CLL (stage III or IV) we found the T cell response in the autologous (auto) and allogeneic (allo) mixed lymphocyte reaction (MLR) to be 35.7% and 30% of the controls, respectively. Proliferation in the MLR depends upon the production of and response to interleukin 2 (IL 2), a T cell growth factor. IL 2 production in eight B-CLL patients was 22% of the control. The response to IL 2 was measured by the increase in the T cell proliferation in the MLR with the addition of IL 2. T cell proliferation in both the auto and allo MLR of CLL patients was significantly lower than in the controls after the addition of IL 2. The proliferative response of normal T cells to stimulation by CLL B cells was 50% of the control. This latter response was increased to control levels when cultures were supplemented with exogenous IL 2, suggesting that CLL B cells could stimulate IL 2 receptor generation in normal T cells in an allo MLR, but not IL 2 production. The presence of IL 2 receptors on activated T cells was directly determined using anti- Tac, a monoclonal antibody with specificity for the IL 2 receptor. Of the mitogen- or MLR-activated T cells in CLL patients, 6% and 10%, respectively, expressed Tac antigen, whereas identically stimulated control T cells were 60% and 47% Tac+, respectively. Our findings suggest that T cells in B-CLL are defective in their recognition of self or foreign major histocompatibility antigens as demonstrated by their impaired responsiveness in the MLR. Thus, these cells are unable to produce IL 2 or generate IL 2 receptors.

scholarly journals Defective interleukin-2 production and responsiveness by T cells in patients with chronic lymphocytic leukemia of B cell variety

Blood ◽  
1986 ◽  
Vol 67 (2) ◽  
pp. 279-284 ◽  
Author(s):  
O Ayanlar-Batuman ◽  
E Ebert ◽  
SP Hauptman
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Proliferative Response ◽  
Interleukin 2 ◽  
Lymphocytic Leukemia ◽  
T Cell Proliferation ◽  
Activated T Cells

The present studies were designed to investigate the mechanism(s) of the defective T cell proliferative response to various stimuli in patients with B cell chronic lymphocytic leukemia B-CLL. In 14 patients with advanced B-CLL (stage III or IV) we found the T cell response in the autologous (auto) and allogeneic (allo) mixed lymphocyte reaction (MLR) to be 35.7% and 30% of the controls, respectively. Proliferation in the MLR depends upon the production of and response to interleukin 2 (IL 2), a T cell growth factor. IL 2 production in eight B-CLL patients was 22% of the control. The response to IL 2 was measured by the increase in the T cell proliferation in the MLR with the addition of IL 2. T cell proliferation in both the auto and allo MLR of CLL patients was significantly lower than in the controls after the addition of IL 2. The proliferative response of normal T cells to stimulation by CLL B cells was 50% of the control. This latter response was increased to control levels when cultures were supplemented with exogenous IL 2, suggesting that CLL B cells could stimulate IL 2 receptor generation in normal T cells in an allo MLR, but not IL 2 production. The presence of IL 2 receptors on activated T cells was directly determined using anti- Tac, a monoclonal antibody with specificity for the IL 2 receptor. Of the mitogen- or MLR-activated T cells in CLL patients, 6% and 10%, respectively, expressed Tac antigen, whereas identically stimulated control T cells were 60% and 47% Tac+, respectively. Our findings suggest that T cells in B-CLL are defective in their recognition of self or foreign major histocompatibility antigens as demonstrated by their impaired responsiveness in the MLR. Thus, these cells are unable to produce IL 2 or generate IL 2 receptors.

Chronic Lymphocytic Leukemia Cells Acquire a Regulatory B-Cell Phenotype Modified By PD1 Signaling

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3319-3319 ◽  
Author(s):  
Shimrit Ringelstein-Harlev ◽  
Irit Avivi ◽  
Shoham Shivtiel-Arad ◽  
Tami Katz
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Immune Responses ◽  
B Cell ◽  
Immune Modulation ◽  
Lymphocytic Leukemia ◽  
T Cell Proliferation ◽  
Cell Contact

Abstract Introduction: Chronic lymphocytic leukemia (CLL) cells utilize several mechanisms of survival, some propagating proliferation and preventing apoptosis through intrinsic cell cycle signals, and others suppressing anti-tumor immune responses. Patients often present with a predominant population of regulatory T-cells (Tregs), and general features of T-cell exhaustion. Given the unique phenotype of CLL cells and the observed T-cell abnormalities we hypothesized that these cells function as regulatory B-cells (Bregs). Bregs, mostly explored in the autoimmune disease setting, produce interleukin-10 (IL10), which mediates attenuation of effector T-cell responses and enhances regulatory activity. These features have also been suggested to be responsible for weakening of anti-tumor immune responses. Breg activation requires stimulation of various combinations of Toll-like receptors (TLRs), the B-cell receptor (BCR) and CD40. Our previous studies have demonstrated that TLR9-stimulated CLL cells "acquire" Breg markers as well as PD1 and PDL1, which, while not being classic Breg discriminators, are established players in immune modulation. Moreover, such stimulation resulted in inhibition of proliferation of autologous T-cells. The current study aimed to further explore the regulatory characteristics of CLL cells focusing on additional suppressive mechanisms that may have a role in CLL immune evasion, particularly, the PD1/PDL1 axis. Methods: B-cells were isolated from peripheral blood mononuclear cells (PBMCs) of untreated CLL patients (Rai stages 0-IV). These B-CLL cells were stimulated with TLR-9 agonist (ODN) or CD40 ligand (CD40L) followed by their co-culture with isolated autologous CD4+ T cells. The regulatory features of B-CLL cells were studied by testing their effect on T cells. Their proliferation was evaluated using the CFSE method following stimulation with anti-CD3/CD28 antibodies and IL2; induction of Tregs (CD4+CD25highFoxp3+ population) was assessed by FACS analysis. The involvement of the PD1/PDL1 axis was examined by incubating B-cells with antiPD1 neutralizing antibodies prior to co-culture. Cell contact dependence was evaluated by plating B-cells in hanging cell culture inserts denying B and T cell contact while allowing flow of small soluble molecules. Results: CLL cells stimulated with ODN or CD40L, induced a significant increase in Tregs: 1.35±0.1-fold (p=0.03, N=12) for ODN and 1.7±0.2-fold (p=0.008, N=14) for CD40L, occurring in 68% and 80% of patients, respectively, while co-culture with unstimulated B-CLL cells did not result in the expansion of the Treg population. Treg induction was observed only under contact conditions (N=5), suggesting that this regulatory function requires cell-to-cell contact and cannot be carried out solely by secreted factors like IL10. Neutralization of PD1 on CLL B-cells affects both Treg induction and T-cell proliferation. Following CD40L stimulation, a 1.3-fold reduction in Treg percentage was observed when PD1 signaling was blunted (N=10). In contrast, PD1 blockage of ODN-stimulated CLL cells did not reduce Treg induction; however, it did adversely affect inhibition of T-cell proliferation (10%-decrease in inhibited T-cells; N=6). Conclusions: CLL cells "acquire" a Breg phenotype and function, inhibiting T-cell proliferation and inducing Tregs. These properties, while working together to promote immune regulation and cancer evasion, are elicited by different ligands in the cell environment and are likely to be mediated via separate pathways. The involvement of B-cell-associated PD1 in the induction of Tregs and inhibition of T-cell proliferation suggests a biologic role of PD1 signaling in CLL cells, strengthening the Breg phenotype. The current study has shown that CLL cells recruit several mechanisms operating cooperatively to support immune modulation and promote their survival. Disclosures No relevant conflicts of interest to declare.

scholarly journals C-Jun Nh2-Terminal Kinase (Jnk)1 and Jnk2 Have Similar and Stage-Dependent Roles in Regulating T Cell Apoptosis and Proliferation

2001 ◽  
Vol 193 (3) ◽  
pp. 317-328 ◽  
Author(s):  
Kanaga Sabapathy ◽  
Tuula Kallunki ◽  
Jean-Pierre David ◽  
Isabella Graef ◽  
Michael Karin ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Cell Function ◽  
Interleukin 2 ◽  
Binding Activity ◽  
T Cell Proliferation ◽  
Activated T Cells ◽  
T Cell Function ◽  
Thymocyte Apoptosis

Apoptotic and mitogenic stimuli activate c-Jun NH2-terminal kinases (JNKs) in T cells. Although T cells express both JNK1 and JNK2 isozymes, the absence of JNK2 alone can result in resistance to anti-CD3–induced thymocyte apoptosis and defective mature T cell proliferation. Similar defects in thymocyte apoptosis and mature T cell proliferation, the latter due to reduced interleukin 2 production, are also caused by JNK1 deficiency. Importantly, T cell function was compromised in Jnk1+/−Jnk2+/− double heterozygous mice, indicating that JNK1 and JNK2 play similar roles in regulating T cell function. The reduced JNK dose results in defective c-Jun NH2-terminal phosphorylation in thymocytes but not in peripheral T cells, in which nuclear factors of activated T cells (NK-ATs)–DNA binding activity is affected. Thus, JNK1 and JNK2 control similar functions during T cell maturation through differential targeting of distinct substrates.

Chronic Lymphocytic Leukemia Cells Exhibit Inhibitory Properties of Regulatory B Cells

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3874-3874
Author(s):  
Shimrit Ringelstein-Harlev ◽  
Irit Avivi ◽  
Lina Bisharat ◽  
Tamar Katz
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Fold Increase ◽  
Lymphocytic Leukemia ◽  
T Cell Proliferation ◽  
Cell Contact ◽  
Stimulation Of

Abstract Abstract 3874 Background: Chronic lymphocytic leukemia (CLL) is a mature B-cell malignancy, characterized by distinct immune suppression rendering both tumor cells and invading pathogens invisible to the immune system. However, CLL cells also display profound immune sensitivity as proven by long-term remissions achieved with allogeneic bone marrow transplantation. Many phenotypic properties of B-CLL cells resemble a subset of B-cells, studied mostly in autoimmunity and termed regulatory B cells (Bregs). Bregs are thought to suppress CD4+ T-cell mediated immune responses, directly through cell contact and indirectly through inhibitory cytokines. This study aims to define whether malignant B-CLL cells exhibit Breg suppressive properties, contributing to immune dysfunction in this disease. Methods: B-cells were isolated from peripheral blood mononuclear cells (PBMCs) of untreated CLL patients (Rai stages 0-IV) using immunomagnetic separation (STEMCELL technologies). Naïve cells and those stimulated with B-cell activators TLR-9 agonist or CD40Ligand (CD40L) were analyzed by FACS for Breg phenotypic markers and intracellular IL-10. Additionally, B-CLL cell effects on autologous CD4+ T cells (isolated by immunomagnetic beads; Miltenyi Biotec) were studied. T-cells were stimulated with anti-CD3/CD28 antibodies and IL-2, and exposed to B-cells either directly or through hanging cell culture inserts (Millipore) preventing physical cell-cell contact. T-cell proliferation was assessed using the carboxyfluorescein diacetate succinimidyl ester (CFSE) method and phenotype was analyzed by FACS. Results: B-cell phenotype was studied in 11 patients. Breg markers (CD5, CD38, CD25 and intracellular IL-10) as well as inhibitory molecules PD-1 and PDL-1 were expressed at high levels on B-CLL cells (62%, 37%, 50%, 52%, 29%, 61%, respectively), although not every patient expressed all markers. These expression levels were higher than those reported for normal peripheral blood B-cells. TLR-9 stimulation of B-CLL cells resulted in a 5.7-fold increase in expression of CD25 in 77% of patients. Increments were also observed in IL-10 (1.9-fold; 62% of patients), PDL-1 (1.96-fold; 83% of patients) and PD-1 (2.19-fold; 57% of patients). Of 13 patients whose T-cell proliferation potential was evaluated after exposure to B-CLL cells, proliferation was induced in only 69%; in the other 31% (4 patients) no proliferation was observed; moreover, inhibition was demonstrated in one of them. Among the former group only 33% of patients expressed CD25 on their B-cells, whereas within the latter group, 75% of patients' B-cells were CD25-positive. Stimulation of B-CLL cells with TLR-9 markedly increased their inhibitory capacity (72% of 11 patients tested), while CD40L stimulation caused a weaker effect (50% of 6 patients tested). T-cell proliferation remained unchanged when evaluated using a Transwell system versus a contact system, as demonstrated in 3 of 4 experiments. T-cells exposed to B-CLL cells altered the ratio of CD25high vs. CD25low T-cells in favor of CD25 high cells (2.44-fold increase for stimulation with naïve B-CLL cells, 4.94-fold increase with TLR-9 stimulated cells; in all the 5 tested patients). Conclusions: Previously identified Breg markers as well as PD-1 and PDL-1 were highly expressed in B-CLL cells, supporting the role of these cells in shaping an immune tolerant environment, enabling tumor growth. Stimulation of B-CLL cells with TLR-9 agonist enhanced this phenotype and resulted in consistent inhibition of T-cell proliferation, likely to be independent of cell-to-cell contact. These findings demonstrate the presence of Breg features within the CLL clone. The observed alterations in CD4+CD25+ T-cell populations after exposure to B-CLL cells suggest induction of T-regulatory cells, another mechanism supposedly used by Bregs for immune suppression. The enhancement of Breg properties in B-CLL cells following B-cell activation can serve as a platform for further studies of the innate regulatory mechanisms utilized by tumor cells. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Expression of interleukin-2 receptor on T cell chronic lymphocytic leukemia cells and their response to interleukin-2

Blood ◽  
1986 ◽  
Vol 67 (2) ◽  
pp. 316-321
Author(s):  
M Tsudo ◽  
T Uchiyama ◽  
H Umadome ◽  
Y Wano ◽  
T Hori ◽  
...  
Keyword(s):  
T Cells ◽  
Monoclonal Antibodies ◽  
T Cell ◽  
Chronic Lymphocytic Leukemia ◽  
Interleukin 2 ◽  
Lymphocytic Leukemia ◽  
Leukemic Cells ◽  
Activated T Cells ◽  
Cell Chronic Lymphocytic Leukemia

We analyzed peripheral blood leukemic cells from six patients with T cell chronic lymphocytic leukemia (T-CLL) with monoclonal antibodies including the anti-Tac antibody, which recognizes the receptor for interleukin 2 (IL 2). The patients were divided into two groups according to the reactivity of the monoclonal antibodies. Leukemic cells from three patients with T-CLL reacted with OKT3 and T4 but not T8, whereas those from the remaining three patients reacted with OKT3 and T8 but not T4. IL 2 receptor, which is expressed on activated T cells but not on resting T cells, was preferentially expressed on T4+ T- CLL cells. The IL 2 receptor on T4+ T-CLL cells was indistinguishable from that on normal activated T cells with respect to molecular weight and downregulation by the anti-Tac antibody. Moreover, fresh T4+ T-CLL cells, but not T8+ T-CLL cells, proliferated in response to exogenous IL 2 without prior activation, and this proliferation was inhibited by the anti-Tac antibody. These results suggest that malignant growth of T4+ T-CLL cells can be regulated by IL 2 not only in vitro but also in vivo.

scholarly journals Defective T cell responsiveness in chronic lymphocytic leukemia: analysis of activation events

Blood ◽  
1986 ◽  
Vol 67 (3) ◽  
pp. 578-581
Author(s):  
NE Kay ◽  
ME Kaplan
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chronic Lymphocytic Leukemia ◽  
Proliferative Response ◽  
Interleukin 2 ◽  
Lymphocytic Leukemia ◽  
Proliferative Potential ◽  
Hla Dr ◽  
Activation Antigens ◽  
T Cell Membrane

Chronic lymphocytic leukemia (CLL) is a B cell disorder in which major T cell proliferative defects are present. We investigated the nature of this deficit by studying several parameters known to be crucial in normal T cell proliferative response to mitogen. Purified peripheral blood T cells from B-CLL patients were analyzed for the presence of T3 antigen. We observed that CLL T cells have a direct correlation between levels of T3 membrane antigen and proliferative response to mitogen. The appearance of activation antigens (transferrin, HLA-DR, and interleukin 2 [IL 2] receptor) was normal in CLL T cells post-mitogen exposure. Despite the normal presentation of IL 2 receptor on CLL T cell membrane, there was decreased production of IL 2 by CLL patients (v controls) (39.6 +/- 10.2 cells per milliliter v 64.6 +/- 11.0 cells per milliliter). Finally, we were able partially, but not fully, to reconstitute CLL T proliferative response to mitogen by adding purified exogenous IL 2. These findings suggest that CLL T cells have multiple defects that may impact on their proliferative potential. Further insight into these deficits may result in strategies that will facilitate immunologic restoration in T cells of these patients.

scholarly journals Expression of interleukin-2 receptor on T cell chronic lymphocytic leukemia cells and their response to interleukin-2

Blood ◽  
1986 ◽  
Vol 67 (2) ◽  
pp. 316-321 ◽  
Author(s):  
M Tsudo ◽  
T Uchiyama ◽  
H Umadome ◽  
Y Wano ◽  
T Hori ◽  
...  
Keyword(s):  
T Cells ◽  
Monoclonal Antibodies ◽  
T Cell ◽  
Chronic Lymphocytic Leukemia ◽  
Interleukin 2 ◽  
Lymphocytic Leukemia ◽  
Leukemic Cells ◽  
Activated T Cells ◽  
Cell Chronic Lymphocytic Leukemia

Abstract We analyzed peripheral blood leukemic cells from six patients with T cell chronic lymphocytic leukemia (T-CLL) with monoclonal antibodies including the anti-Tac antibody, which recognizes the receptor for interleukin 2 (IL 2). The patients were divided into two groups according to the reactivity of the monoclonal antibodies. Leukemic cells from three patients with T-CLL reacted with OKT3 and T4 but not T8, whereas those from the remaining three patients reacted with OKT3 and T8 but not T4. IL 2 receptor, which is expressed on activated T cells but not on resting T cells, was preferentially expressed on T4+ T- CLL cells. The IL 2 receptor on T4+ T-CLL cells was indistinguishable from that on normal activated T cells with respect to molecular weight and downregulation by the anti-Tac antibody. Moreover, fresh T4+ T-CLL cells, but not T8+ T-CLL cells, proliferated in response to exogenous IL 2 without prior activation, and this proliferation was inhibited by the anti-Tac antibody. These results suggest that malignant growth of T4+ T-CLL cells can be regulated by IL 2 not only in vitro but also in vivo.

scholarly journals Defective T cell responsiveness in chronic lymphocytic leukemia: analysis of activation events

Blood ◽  
1986 ◽  
Vol 67 (3) ◽  
pp. 578-581 ◽  
Author(s):  
NE Kay ◽  
ME Kaplan
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chronic Lymphocytic Leukemia ◽  
Proliferative Response ◽  
Interleukin 2 ◽  
Lymphocytic Leukemia ◽  
Proliferative Potential ◽  
Hla Dr ◽  
Activation Antigens ◽  
T Cell Membrane

Abstract Chronic lymphocytic leukemia (CLL) is a B cell disorder in which major T cell proliferative defects are present. We investigated the nature of this deficit by studying several parameters known to be crucial in normal T cell proliferative response to mitogen. Purified peripheral blood T cells from B-CLL patients were analyzed for the presence of T3 antigen. We observed that CLL T cells have a direct correlation between levels of T3 membrane antigen and proliferative response to mitogen. The appearance of activation antigens (transferrin, HLA-DR, and interleukin 2 [IL 2] receptor) was normal in CLL T cells post-mitogen exposure. Despite the normal presentation of IL 2 receptor on CLL T cell membrane, there was decreased production of IL 2 by CLL patients (v controls) (39.6 +/- 10.2 cells per milliliter v 64.6 +/- 11.0 cells per milliliter). Finally, we were able partially, but not fully, to reconstitute CLL T proliferative response to mitogen by adding purified exogenous IL 2. These findings suggest that CLL T cells have multiple defects that may impact on their proliferative potential. Further insight into these deficits may result in strategies that will facilitate immunologic restoration in T cells of these patients.

T-cell proliferation involving the CD28 pathway is associated with cyclosporine-resistant interleukin 2 gene expression

1987 ◽  
Vol 7 (12) ◽  
pp. 4472-4481
Author(s):  
C H June ◽  
J A Ledbetter ◽  
M M Gillespie ◽  
T Lindsten ◽  
C B Thompson
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
T Cell Proliferation ◽  
Cd28 Molecule ◽  
T Cell Stimulation ◽  
Protein Kinase C Activation

CD28 is a homodimeric glycoprotein expressed on the surface of a major subset of human T cells that has recently been identified as a member of the immunoglobulin supergene family. The binding of monoclonal antibodies to the CD28 antigen on purified T cells does not result in proliferation; however, previous studies have shown that the combination of CD28 stimulation and protein kinase C activation by phorbol myristate acetate (PMA) results in T-cell proliferation that is independent of both accessory cells and activation of the T-cell receptor-CD3 complex. In the present study, effects of stimulation by anti-CD28 on cell cycle progression and on the interleukin 2 (IL-2) and IL-2 receptor system have been investigated on primary cultures of purified peripheral-blood CD28+ T cells. There was no measurable effect on cell size or on DNA synthesis after stimulation of resting (G0) cells by CD28 alone. After 3 h of activation of T cells by PMA alone, a slight (8%) increase in cell volume occurred that did not progress to DNA synthesis. In contrast, T-cell stimulation by CD28 in combination with PMA resulted in a progressive increase in cell volume in approximately 100% of cells at 12 to 14 h after stimulation. Northern blot (RNA blot) analysis revealed that CD28 stimulation alone failed to cause expression of the alpha chain of the IL-2 receptor or of IL-2 mRNA, and in accord with previous studies, stimulation by PMA alone resulted in the accumulation of IL-2 receptor transcripts but no detectable IL-2 mRNA. In contrast, T-cell stimulation by the combination of CD28 and PMA resulted in the appearance of IL-2 transcripts and enhanced expression of IL-2 receptor mRNA. Functional studies revealed that the proliferation induced by CD28 and PMA stimulation was entirely resistant to cyclosporine, in contrast to T-cell activation induced by the CD3-T-cell receptor complex. Cyclosporine was found not to affect the accumulation of IL-2 mRNA after CD28 plus PMA stimulation, although there was no detectable IL-2 mRNA after stimulation by CD3 in the presence of the drug. Furthermore, stimulation by CD28 in combination with immobilized CD3 antibodies caused a striking enhancement of IL-2 mRNA expression that was, in part, resistant to the effects of cyclosporine. These studies indicate that the CD28 molecule synergizes with protein kinase C activation to induce IL-2 gene expression and demonstrate that stimulation by the CD28 pathway can cause vigorous T-cell proliferation even in the presence of cyclosporine and that cyclosporine does not prevent transcription of 16-2 mRNA, as has been suggested previously. Moreover, these findings suggest that a potential role for the CD28 molecule in vivo may be to augment IL-2 production after stimulation of the CD3-T-cell receptor molecular complex and thereby to amplify an antigen-specific immune response. Finally, these results provide further evidence that the CD28 molecule triggers T-cell proliferation in a manner that differs biochemically from CD3-T-cell receptor-induced proliferation.

scholarly journals Defective T cell-mediated, isotype-specific immunoglobulin regulation in B cell chronic lymphocytic leukemia

Blood ◽  
1988 ◽  
Vol 71 (4) ◽  
pp. 1012-1020 ◽  
Author(s):  
JS Moore ◽  
MB Prystowsky ◽  
RG Hoover ◽  
EC Besa ◽  
PC Nowell
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Cell Activity ◽  
Lymphocytic Leukemia ◽  
Specific Immunoglobulin ◽  
Cell Chronic Lymphocytic Leukemia

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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