Defective LFA-1 Mediated T Cell Motility In Chronic Lymphocytic Leukemia Is Mediated by Defects In the Rho GTPase Signaling Pathway

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 914-914
Author(s):  
Alan G. Ramsay ◽  
Rachel Evans ◽  
Lena Svensson ◽  
Shahryar Kiaii ◽  
Nancy Hogg ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Migration ◽  
Cell Adhesion ◽  
T Cell ◽  
Chronic Lymphocytic Leukemia ◽  
Cell Motility ◽  
Healthy Donor ◽  
Rho Gtpase ◽  
Lymphocytic Leukemia ◽  
Donor T Cells

Abstract Abstract 914 T lymphocytes have an essential role in adaptive immunity and rely on tightly regulated signaling through integrin lymphocyte function-associated antigen (LFA)-1 to migrate into lymph nodes and interact with antigen-presenting cells. Malignant cells modify their immune microenvironment to prevent effective host anti-tumor responses, promote tumor progression, and suppress the therapeutic benefit of immunotherapy treatments. Here we assessed LFA-1-mediated cell migration of highly purified T cells from treatment naïve chronic lymphocytic leukemia (CLL) patients compared to age-matched healthy donor T cells using CXCL12 stimulation and immobilized ICAM-1, the principal integrin ligand. Video microscopy with motility tracking analysis identified that both CD4 and CD8 T cells from CLL patients (n=14) exhibited significantly reduced migration rates (P < .01) compared to healthy donor T cells (5.5 ± 0.3 (SEM) μm/min and 4.4 ± 0.2 μm/min compared to 8.2 ± 0.3 μm/min and 7.5 ± 0.3 μm/min respectively). We further identified that direct CLL cell contact, and not soluble factors alone, induced similar T cell motility dysfunction in previously healthy CD3 T cells. Primary co-culture of healthy donor T cells with CLL cells caused a significant decrease in the speed of migration on ICAM-1 compared to coculture with control healthy B cells (6.2 ± 0.3 μm/min versus 9.5 ± 0.6 μm/min) (n=9) (P < .05). Next we sought to repair this T cell defect in CLL using a clinically relevant agent. We identify that treatment of CLL patient T cells (n=9) with lenalidomide restores rapid LFA-1 mediated migration on ICAM-1. Ex vivo treatment of CLL T cells with lenalidomide (1μM for 24 hours) significantly increased the speed of T cell migration compared to untreated patient T cells (7 ± 0.4 μm/min versus 2.5 ± 0.7 μm/min) (P < .05) and the rescued T cell migratory function of lenalidomide exposed patient T cells was comparable to healthy donor T cells treated with or without drug. Interference reflection microscopy (IRM) examining the contact zone between migrating T cells and ICAM-1 identified a significant CLL patient T cell adhesion defect (P < .05) with reduced spreading area and strength of adhesive contacts (pixel density) compared to healthy donor T cells. IRM was further utilized with pharmacological inhibitors to demonstrate that exposure to lenalidomide rescued CLL T cell adhesion by acting on the Rho family GTPases that are dysregulated in cancer patient T cells. Lenalidomide significantly increased (P < .05) levels of active RhoA in CLL patient T cells compared to untreated cells. In addition, untreated CLL patient T cells adhering to ICAM-1 exhibited significantly reduced expression levels of phosphorylated myosin light chain (MLC) compared to healthy donor T cells (P < .05) and this defect was repaired following lenalidomide treatment. MLC is normally phosphorylated by MLC kinase at the T cell leading edge and by the RhoA target, ROCK at the trailing edge, and is an important downstream signaling molecule during LFA-1-mediated T cell motility. Further expression analysis identified that lenalidomide significantly increased (P < .01) ICAM-1-engaged high-affinity LFA-1 in CLL patient T cells to levels comparable to healthy donor T cells. Overall, our results show that T cells in CLL patients have dysfunctional tumor-induced cytoskeletal signaling via the Rho GTPase signaling pathway, and this is reversed by lenalidomide, rescuing dynamic LFA-1 mediated outside-in signalling and migration. Lenalidomide's immunomodulatory activity was highly cancer T cell specific: rescuing defective LFA-1 migration and signaling in CLL T cells, but with no detectable effects on healthy donor T cells. These findings provide important mechanistic insight into the action of lenalidomide, and highlight the potential clinical utility of immunomodulatory drugs to rescue normal immune function in cancer. Disclosures: Gribben: Roche: Consultancy; Celgene: Consultancy; GSK: Honoraria; Napp: Honoraria.

scholarly journals Chronic lymphocytic leukemia cells induce defective LFA-1–directed T-cell motility by altering Rho GTPase signaling that is reversible with lenalidomide

Blood ◽  
2013 ◽  
Vol 121 (14) ◽  
pp. 2704-2714 ◽  
Author(s):  
Alan G. Ramsay ◽  
Rachel Evans ◽  
Shahryar Kiaii ◽  
Lena Svensson ◽  
Nancy Hogg ◽  
...  
Keyword(s):  
T Cell ◽  
Chronic Lymphocytic Leukemia ◽  
Cell Motility ◽  
Rho Gtpase ◽  
Lymphocytic Leukemia ◽  
Leukemia Cells ◽  
Key Points ◽  
Gtpase Activation ◽  
Activation Signaling

Key Points CLL cells induce defects in T-cell LFA-1–mediated migration by altering Rho GTPase activation signaling, downregulating RhoA and Rac1, and upregulating Cdc42. Lenalidomide repairs these T-cell defects by restoring normal Rho GTPase activation signaling.

scholarly journals Multiple inhibitory ligands induce impaired T-cell immunologic synapse function in chronic lymphocytic leukemia that can be blocked with lenalidomide: establishing a reversible immune evasion mechanism in human cancer

Blood ◽  
2012 ◽  
Vol 120 (7) ◽  
pp. 1412-1421 ◽  
Author(s):  
Alan G. Ramsay ◽  
Andrew J. Clear ◽  
Rewas Fatah ◽  
John G. Gribben
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chronic Lymphocytic Leukemia ◽  
Immune Evasion ◽  
Actin Polymerization ◽  
Rho Gtpase ◽  
Small Gtpases ◽  
Lymphocytic Leukemia ◽  
Functional Screening ◽  
Immunologic Synapse

Abstract Cancer immune evasion is an emerging hallmark of disease progression. We have demonstrated previously that impaired actin polymerization at the T-cell immunologic synapse is a global immune dysfunction in chronic lymphocytic leukemia (CLL). Direct contact with tumor cells induces defective actin polarization at the synapse in previously healthy T cells, but the molecules mediating this dysfunction were not known. In the present study, we show via functional screening assays that CD200, CD270, CD274, and CD276 are coopted by CLL cells to induce impaired actin synapse formation in both allogeneic and autologous T cells. We also show that inhibitory ligand–induced impairment of T-cell actin dynamics is a common immunosuppressive strategy used by both hematologic (including lymphoma) and solid carcinoma cells. This immunosuppressive signaling targets T-cell Rho-GTPase activation. Of clinical relevance, the immunomodulatory drug lenalidomide prevented the induction of these defects by down-regulating tumor cell–inhibitory molecule expression. These results using human CLL as a model cancer establish a novel evasion mechanism whereby malignant cells exploit multiple inhibitory ligand signaling to down-regulate small GTPases and lytic synapse function in global T-cell populations. These findings should contribute to the design of immunotherapeutic strategies to reverse T-cell tolerance in cancer.

Defective T Cell Migration in Chronic Lymphocytic Leukemia Is Repaired by Lenalidomide

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3117-3117
Author(s):  
Alan G. Ramsay ◽  
Lena Svensson ◽  
Nancy Hogg ◽  
John G. Gribben
Keyword(s):  
T Cells ◽  
Cell Migration ◽  
T Cell ◽  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
Cd8 T Cells ◽  
Direct Contact ◽  
Immune Surveillance ◽  
Lymphocytic Leukemia ◽  
T Cell Migration

Abstract We have previously demonstrated that multiple gene expression abnormalities are induced in T cells from chronic lymphocytic leukemia (CLL) patients including defects within the actin cytoskeleton signaling pathways that control immune recognition and motility (Gullu et al. JCI, 2005). T cell immune surveillance requires rapid migratory responses and LFA-1 (CD11a/CD18; αLβ2) is a promigratory receptor that engages the cytoskeleton to control migration. We hypothesized that CLL T cells may exhibit dysfunctional migration in response to ICAM-1, the principal ligand for LFA-1. Using time lapse microscopy, we observed significantly reduced chemokine SDF-1 (CXCL12) induced migration on ICAM-1 of CLL CD4 and CD8 T cells compared to age-matched healthy donor T cells. Healthy T cells tracked for 45 min displayed a random course of migration with an average speed of ~ 8 μm/min, whereas CLL T cells were slower ~ 5 μm/min (n=14, ~ 30% reduction, p<0.01). We further postulated that direct contact of CLL tumor cells with healthy T cells would induce this migratory defect. Healthy CD4 or CD8 T cells were cocultured with either allogeneic CLL B cells or allogeneic healthy B cells and subsequently used in migration assays. Co-culture with CLL cells resulted in significantly reduced T cell migration compared with co-culture with healthy B cells (~ 44% reduction in migration, n=6, p<0.01). Evidence that direct contact was required to induce this migratory defect was shown when no effect was observed when cell-cell adhesion was prevented by pretreatment of CLL cells with anti-ICAM-1 blocking antibody prior to primary co-culture with healthy T cells. This cancer-induced migratory defect was repaired when CLL T cells were pretreated with the immunomodulatory drug Lenalidomide (1μM for 1hr). Treatment with this agent enhanced the migratory potential of CLL T cells to a speed comparable to untreated and treated healthy T cells. The finding that lenalidomide can restore rapid migration in patient T cells provides evidence that this agent may increase immune surveillance in CLL patients.

Impaired Actin Polymerization Results in Defective Immunological Synapse Formation in T Cells in Chronic Lymphocytic Leukemia.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 338-338 ◽  
Author(s):  
Alan G. Ramsay ◽  
Abigail M. Lee ◽  
John G. Gribben
Keyword(s):  
Immune Deficiency ◽  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
Molecular Basis ◽  
Actin Polymerization ◽  
Immunological Synapse ◽  
Lymphocytic Leukemia ◽  
Donor T Cells

Abstract Cancer is associated with immune deficiency, but the molecular basis for this is poorly defined. We have previously demonstrated that multiple gene expression abnormalities are induced in patients with chronic lymphocytic leukemia (CLL) including defects within the actin cytoskeleton formation pathways. Based on this data, we hypothesized that failure of actin polymerization would result in defects in the formation of the immunological synapse (IS) which is critical for T cell activation and effector function. To assess this, actin polymerization at the IS in T cells in response to superantigen-pulsed B cells (APCs) was visualized using confocal microscopy. We observed significantly reduced ability to polymerize actin at the IS (> 50% reduction) in autologous CD4 and CD8 T cells from previously untreated CLL patients compared to age-matched healthy donors (p<0.05). Since reduced IS formation could result from defects in T cells, APCs or both, we examined IS formation in mixing experiments using T cells or APCs from leukemic patients with healthy allogeneic cells. These experiments demonstrated impaired IS formation using T cells from patients with CLL (p<0.01) or CLL cells as APCs (p<0.01), in keeping with defects in both T cells and APC function of CLL cells. We further postulated that interaction of CLL cells with healthy T cells would induce similar changes. Healthy allogeneic T cells were co-cultured for 48 hours with either allogeneic CLL cells or healthy B cells. Co-culture with CLL cells resulted in subsequent significant impairment in IS formation of the T cells with healthy superantigen pulsed APCs (p<0.01). Blocking experiments using anti-LFA-1 and anti-ICAM1 monoclonal antibodies with CLL B cells prevented subsequent actin remodelling impairment at the IS in the healthy allogeneic donor T cells. Further evidence that direct cell contact with CLL cells and not soluble factors is required to induce this T cell immune defect was provided by the finding that there was no impairment on IS formation when the T cells were co-cultured with CLL cells in transwell culture assays. The finding that direct contact of CLL cells with allogeneic T cells induces impairment in IS formation is relevant for the use of donor lymphocyte infusions in the setting of bulk disease. Co-localization experiments assessed by confocal microscopy suggest that the molecular basis for the defective T cells function stems from inability in T cells from CLL patients to recruit key proteins to the IS efficiently compared to healthy donor T cells. Greater than 50% reduction in co-localization at the IS was seen for dynamin 2, filamin A and LFA-1 integrin (p<0.05). These assays provide a rapid and simple method to assess T cell impairment in cancer and can be used to determine if steps to attempt to improve defective T cell function in cancer are successful. The finding of impaired IS formation as a key T cell defect in these cancer bearing patients has implications for both autologous and allogeneic immunotherapy approaches and identify both IS formation and the molecules regulating its organisation as potential functional markers and targets for the reversal of immune deficiency in cancer.

scholarly journals Targeting CD38 is lethal to Breg-like chronic lymphocytic leukemia cells and Tregs, but restores CD8+ T-cell responses

2020 ◽  
Vol 4 (10) ◽  
pp. 2143-2157 ◽  
Author(s):  
Alak Manna ◽  
Timothy Kellett ◽  
Sonikpreet Aulakh ◽  
Laura J. Lewis-Tuffin ◽  
Navnita Dutta ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chronic Lymphocytic Leukemia ◽  
Cd8 T Cells ◽  
Mononuclear Cells ◽  
Transforming Growth Factor ◽  
Ex Vivo ◽  
Xenograft Model ◽  
Lymphocytic Leukemia ◽  
Dependent Manner

Abstract Patients with chronic lymphocytic leukemia (CLL) are characterized by monoclonal expansion of CD5+CD23+CD27+CD19+κ/λ+ B lymphocytes and are clinically noted to have profound immune suppression. In these patients, it has been recently shown that a subset of B cells possesses regulatory functions and secretes high levels of interleukin 10 (IL-10). Our investigation identified that CLL cells with a CD19+CD24+CD38hi immunophenotype (B regulatory cell [Breg]–like CLL cells) produce high amounts of IL-10 and transforming growth factor β (TGF-β) and are capable of transforming naive T helper cells into CD4+CD25+FoxP3+ T regulatory cells (Tregs) in an IL-10/TGF-β-dependent manner. A strong correlation between the percentage of CD38+ CLL cells and Tregs was observed. CD38hi Tregs comprised more than 50% of Tregs in peripheral blood mononuclear cells (PBMCs) in patients with CLL. Anti-CD38 targeting agents resulted in lethality of both Breg-like CLL and Treg cells via apoptosis. Ex vivo, use of anti-CD38 monoclonal antibody (mAb) therapy was associated with a reduction in IL-10 and CLL patient-derived Tregs, but an increase in interferon-γ and proliferation of cytotoxic CD8+ T cells with an activated phenotype, which showed an improved ability to lyse patient-autologous CLL cells. Finally, effects of anti-CD38 mAb therapy were validated in a CLL–patient-derived xenograft model in vivo, which showed decreased percentage of Bregs, Tregs, and PD1+CD38hiCD8+ T cells, but increased Th17 and CD8+ T cells (vs vehicle). Altogether, our results demonstrate that targeting CD38 in CLL can modulate the tumor microenvironment; skewing T-cell populations from an immunosuppressive to immune-reactive milieu, thus promoting immune reconstitution for enhanced anti-CLL response.

scholarly journals Immunomodulatory effects of different intravenous immunoglobulin preparations in chronic lymphocytic leukemia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ana Colado ◽  
Esteban Enrique Elías ◽  
Valeria Judith Sarapura Martínez ◽  
Gregorio Cordini ◽  
Pablo Morande ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
T Cell Activation ◽  
Cell Activation ◽  
Lymphocytic Leukemia ◽  
Immunomodulatory Effects ◽  
Immunoglobulin Preparations

AbstractHypogammaglobulinemia is the most frequently observed immune defect in chronic lymphocytic leukemia (CLL). Although CLL patients usually have low serum levels of all isotypes (IgG, IgM and IgA), standard immunoglobulin (Ig) preparations for replacement therapy administrated to these patients contain more than 95% of IgG. Pentaglobin is an Ig preparation of intravenous application (IVIg) enriched with IgM and IgA (IVIgGMA), with the potential benefit to restore the Ig levels of all isotypes. Because IVIg preparations at high doses have well-documented anti-inflammatory and immunomodulatory effects, we aimed to evaluate the capacity of Pentaglobin and a standard IVIg preparation to affect leukemic and T cells from CLL patients. In contrast to standard IVIg, we found that IVIgGMA did not modify T cell activation and had a lower inhibitory effect on T cell proliferation. Regarding the activation of leukemic B cells through BCR, it was similarly reduced by both IVIgGMA and IVIgG. None of these IVIg preparations modified spontaneous apoptosis of T or leukemic B cells. However, the addition of IVIgGMA on in vitro cultures decreased the apoptosis of T cells induced by the BCL-2 inhibitor, venetoclax. Importantly, IVIgGMA did not impair venetoclax-induced apoptosis of leukemic B cells. Overall, our results add new data on the effects of different preparations of IVIg in CLL, and show that the IgM/IgA enriched preparation not only affects relevant mechanisms involved in CLL pathogenesis but also has a particular profile of immunomodulatory effects on T cells that deserves further investigation.

Evaluation of vecabrutinib as a model for non-covalent BTK/ITK inhibition for treatment of chronic lymphocytic leukemia

Blood ◽  
2021 ◽  
Author(s):  
Billy Michael Chelliah Jebaraj ◽  
Annika Müller ◽  
Rashmi Priyadharshini Dheenadayalan ◽  
Sascha Endres ◽  
Philipp M. Roessner ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chronic Lymphocytic Leukemia ◽  
Inhibitory Effect ◽  
Lymphocytic Leukemia ◽  
Transfer Model ◽  
Treatment Benefit ◽  
Btk Inhibitors

Covalent Bruton tyrosine kinase (BTK) inhibitors such as ibrutinib have proven to be highly beneficial in the treatment of chronic lymphocytic leukemia (CLL). Interestingly, the off-target inhibition of IL-2-inducible T-cell kinase (ITK) by ibrutinib may also play a role in modulating the tumor microenvironment, potentially enhancing the treatment benefit. However, resistance to covalently binding BTK inhibitors can develop by a mutation in cysteine 481 of BTK (C481S), which prevents the irreversible binding of the drugs. In the present study we performed pre-clinical characterization of vecabrutinib, a next generation non-covalent BTK inhibitor, with ITK inhibitory properties similar to those of ibrutinib. Unlike ibrutinib and other covalent BTK inhibitors, vecabrutinib showed retention of the inhibitory effect on C481S BTK mutants in vitro, similar to that of wildtype BTK. In the murine Eµ-TCL1 adoptive transfer model, vecabrutinib reduced tumor burden and significantly improved survival. Vecabrutinib treatment led to a decrease in CD8+ effector and memory T-cell populations, while the naïve populations were increased. Of importance, vecabrutinib treatment significantly reduced frequency of regulatory CD4+ T-cells (Tregs) in vivo. Unlike ibrutinib, vecabrutinib treatment showed minimal adverse impact on activation and proliferation of isolated T-cells. Lastly, combination treatment of vecabrutinib with venetoclax was found to augment treatment efficacy, significantly improve survival and lead to favourable reprogramming of the microenvironment in the murine Eµ-TCL1 model. Thus, non-covalent BTK/ITK inhibitors such as vecabrutinib may be efficacious in C481S BTK mutant CLL, while preserving the T-cell immunomodulatory function of ibrutinib.

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.

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.

CD40-Activated B-Cell Chronic Lymphocytic Leukemia Cells for Tumor Immunotherapy: Stimulation of Allogeneic Versus Autologous T Cells Generates Different Types of Effector Cells

Blood ◽  
1999 ◽  
Vol 93 (6) ◽  
pp. 1992-2002 ◽  
Author(s):  
Raymund Buhmann ◽  
Annette Nolte ◽  
Doreen Westhaus ◽  
Bertold Emmerich ◽  
Michael Hallek
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Tumor Antigens ◽  
Lymphocytic Leukemia ◽  
T Cell Anergy ◽  
Cell Anergy ◽  
Cell Chronic Lymphocytic Leukemia ◽  
Stimulation Of

Although spontaneous remissions may rarely occur in B-cell chronic lymphocytic leukemia (B-CLL), T cells do generally not develop a clinically significant response against B-CLL cells. Because this T-cell anergy against B-CLL cells may be caused by the inability of B-CLL cells to present tumor-antigens efficiently, we examined the possibility of upregulating critical costimulatory (B7-1 and B7-2) and adhesion molecules (ICAM-1 and LFA-3) on B-CLL cells to improve antigen presentation. The stimulation of B-CLL cells via CD40 by culture on CD40L expressing feeder cells induced a strong upregulation of costimulatory and adhesion molecules and turned the B-CLL cells into efficient antigen-presenting cells (APCs). CD40-activated B-CLL (CD40-CLL) cells stimulated the proliferation of both CD4+ and CD8+ T cells. Interestingly, stimulation of allogeneic versus autologous T cells resulted in the expansion of different effector populations. Allogeneic CD40-CLL cells allowed for the expansion of specific CD8+cytolytic T cells (CTL). In marked contrast, autologous CD40-CLL cells did not induce a relevant CTL response, but rather stimulated a CD4+, Th1-like T-cell population that expressed high levels of CD40L and released interferon-γ in response to stimulation by CD40-CLL cells. Together, these results support the view that CD40 activation of B-CLL cells might reverse T-cell anergy against the neoplastic cell clone, although the character of the immune response depends on the major histocompatibility complex (MHC) background on which the CLL or tumor antigens are presented. These findings may have important implications for the design of cellular immunotherapies for B-CLL.

Sign in / Sign up

Export Citation Format

Share Document