HLA-G Antigen Expression Is Associated with a More Aggressive, Unfavorable Outcome and Immunosuppression in Chronic Lymphocytic Leukemia.

Abstract Background: The human leukocyte antigen (HLA)-G molecule exhibits limited tissue distribution and exerts multiple immunoregulatory functions. Recent studies indicate an ectopic up-regulation in tumor cells which may favor their escape from antitumor immune responses. The role of HLA-G in B cell chronic lymphocytic leukemia (B-CLL) has not been defined. Experimental design: HLA-G expression was studied retrospectively in circulating B-CLL cells from 47 patients by flow cytometry using the MEM/G9 monoclonal antibody. Results: The proportion of leukemic cells expressing HLA-G varied from 1% to 54%. Patients with < 23% HLA-G positive cells (according to ROC analysis; designated as the HLA-G negative group) had a significantly longer progression-free survival (PFS) time than patients with > 23% of positive cells (median PFS 120 versus 23 months, p=0.0001). Multivariate analysis revealed that HLA-G expression (hazard ratio 4.81; p=0.002) was next to the initial staging according to Binet (hazard ratio 8.6; p=0.0001) the best independent prognostic factor compared to other known prognostic factors like ZAP-70 status (hazard ratio 3.6; p=0.029) or CD38 status (hazard ratio 1.83; p=0.37). Humoral and cellular immunosuppression was significantly more prominent in HLA-G positive as compared to HLA-G negative patients group (median immunglobuline G (g/l) 4.3 versus 7.3; median total T-cells (per μl) 824 versus 2540). Conclusions: In B-CLL the level of HLA-G expression is correlated with the degree of immunosuppression and prognosis. To our knowledge this is the first report that describes an association of HLA-G antigen expression and the course of the disease in B-CLL patients. Thus, HLA-G may contribute to the impairment of immune responses against tumor cells and infections. These findings need to be confirmed in a prospective study.

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HLA-G expression is associated with an unfavorable outcome and immunodeficiency in chronic lymphocytic leukemia

Blood ◽

10.1182/blood-2004-08-3335 ◽

2005 ◽

Vol 105 (4) ◽

pp. 1694-1698 ◽

Cited By ~ 111

Author(s):

Holger Nückel ◽

Vera Rebmann ◽

Jan Dürig ◽

Ulrich Dührsen ◽

Hans Grosse-Wilde

Keyword(s):

Chronic Lymphocytic Leukemia ◽

Immune Responses ◽

Tumor Cells ◽

Human Leukocyte ◽

Progression Free Survival ◽

Lymphocytic Leukemia ◽

Leukemic Cells ◽

Operating Characteristics ◽

Leukocyte Antigen ◽

A Prospective Study

AbstractThe human leukocyte antigen G (HLA-G) molecule exhibits limited tissue distribution and exerts multiple immunoregulatory functions. Recent studies indicate an ectopic up-regulation in tumor cells that may favor their escape from antitumor immune responses. The role of HLA-G in B-cell chronic lymphocytic leukemia (B-CLL) has not been defined. HLA-G expression was studied retrospectively in circulating B-CLL cells from 47 patients by flow cytometry using the anti-HLA-E specific monoclonal antibody MEM/G9. The proportion of leukemic cells expressing HLA-G varied from 1% to 54%. Patients with 23% or fewer HLA-G-positive cells (according to receiver operating characteristics [ROC] analysis; designated as HLA-G-negative group) had a significantly longer progression-free survival (PFS) time than patients with more than 23% positive cells (median PFS: 120 versus 23 months; P = .0001). In multivariate analysis, HLA-G expression (hazard ratio: 4.8; P = .002) was an even better independent prognostic factor than the zeta-associated protein 70 (ZAP-70) or CD38 status. Humoral and cellular immunosuppression were significantly more prominent in the HLA-G-positive compared with the HLA-G-negative patient group. In B-CLL, the level of HLA-G expression is correlated with the degree of immunosuppression and prognosis. HLA-G may contribute to the impairment of immune responses against tumor cells and infections. Thus, these findings need to be confirmed in a prospective study. (Blood. 2005;105:1694-1698)

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Is immune escape via human leukocyte antigen expression clinically relevant in chronic lymphocytic leukemia? Focus on the controversies

Leukemia Research ◽

10.1016/j.leukres.2012.12.021 ◽

2013 ◽

Vol 37 (4) ◽

pp. 473-477 ◽

Cited By ~ 7

Author(s):

Nicolas Guillaume ◽

Jean-Pierre Marolleau

Keyword(s):

Chronic Lymphocytic Leukemia ◽

Human Leukocyte Antigen ◽

Immune Escape ◽

Human Leukocyte ◽

Antigen Expression ◽

Lymphocytic Leukemia ◽

Leukocyte Antigen

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Substantial Susceptibility of Chronic Lymphocytic Leukemia to BCL2 Inhibition: Results of a Phase I Study of Navitoclax in Patients With Relapsed or Refractory Disease

Journal of Clinical Oncology ◽

10.1200/jco.2011.34.7898 ◽

2012 ◽

Vol 30 (5) ◽

pp. 488-496 ◽

Cited By ~ 524

Author(s):

Andrew W. Roberts ◽

John F. Seymour ◽

Jennifer R. Brown ◽

William G. Wierda ◽

Thomas J. Kipps ◽

...

Keyword(s):

Chronic Lymphocytic Leukemia ◽

Phase I ◽

Progression Free Survival ◽

Lymphocytic Leukemia ◽

Leukemic Cells ◽

Refractory Disease ◽

Phase Ii Studies ◽

Continual Reassessment ◽

Related Proteins

Purpose BCL2 overexpression is a hallmark of chronic lymphocytic leukemia (CLL). The novel BH3 mimetic navitoclax (ABT-263) specifically inhibits BCL2 and related proteins BCL-xl and BCL-w, potently inducing apoptosis of CLL cells in vitro. A phase I trial in patients with CLL was conducted to evaluate the safety, pharmacokinetics, and biologic activity of oral navitoclax. Patients and Methods Twenty-nine patients with relapsed or refractory CLL received daily navitoclax for 14 days (10, 110, 200, or 250 mg/d; n = 15) or 21 days (125, 200, 250, or 300 mg/d; n = 14) of each 21-day cycle. Dose escalation decisions were informed by continual reassessment methodology. Results Lymphocytosis was reduced by more than 50% in 19 of 21 patients with baseline lymphocytosis. Among 26 patients treated with navitoclax ≥ 110 mg/d, nine (35%) achieved a partial response and seven maintained stable disease for more than 6 months. Median treatment duration was 7 months (range, 1 to ≥ 29 months). Median progression-free survival was 25 months. Activity was observed in patients with fludarabine-refractory disease, bulky adenopathy, and del(17p) CLL. Thrombocytopenia due to BCL-xl inhibition was the major dose-limiting toxicity and was dose-related. Low MCL1 expression and high BIM:MCL1 or BIM:BCL2 ratios in leukemic cells correlated with response. We determined that the navitoclax dose of 250 mg/d in a continuous dosing schedule was optimal for phase II studies. Conclusion BCL2 is a valid therapeutic target in CLL, and its inhibition by navitoclax warrants further evaluation as monotherapy and in combination in this disease.

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Immune Response Dysfunction in Chronic Lymphocytic Leukemia: Dissecting Molecular Mechanisms and Microenvironmental Conditions

International Journal of Molecular Sciences ◽

10.3390/ijms21051825 ◽

2020 ◽

Vol 21 (5) ◽

pp. 1825 ◽

Cited By ~ 8

Author(s):

Francesca Arruga ◽

Benjamin Baffour Gyau ◽

Andrea Iannello ◽

Nicoletta Vitale ◽

Tiziana Vaisitti ◽

...

Keyword(s):

Immune Response ◽

T Cell ◽

Chronic Lymphocytic Leukemia ◽

Immune Responses ◽

T Lymphocyte ◽

Molecular Mechanisms ◽

Cell Activity ◽

Lymphocytic Leukemia ◽

Leukemic Cells ◽

Adaptive Immune

Representing the major cause of morbidity and mortality for chronic lymphocytic leukemia (CLL) patients, immunosuppression is a common feature of the disease. Effectors of the innate and the adaptive immune response show marked dysfunction and skewing towards the generation of a tolerant environment that favors disease expansion. Major deregulations are found in the T lymphocyte compartment, with inhibition of CD8+ cytotoxic and CD4+ activated effector T cells, replaced by exhausted and more tolerogenic subsets. Likewise, differentiation of monocytes towards a suppressive M2-like phenotype is induced at the expense of pro-inflammatory sub-populations. Thanks to their B-regulatory phenotype, leukemic cells play a central role in driving immunosuppression, progressively inhibiting immune responses. A number of signaling cascades triggered by soluble mediators and cell–cell contacts contribute to immunomodulation in CLL, fostered also by local environmental conditions, such as hypoxia and derived metabolic acidosis. Specifically, molecular pathways modulating T-cell activity in CLL, spanning from the best known cytotoxic T lymphocyte antigen-4 (CTLA-4) and programmed cell death 1 (PD-1) to the emerging T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif domains (TIGIT)/CD155 axes, are attracting increasing research interest and therapeutic relevance also in the CLL field. On the other hand, in the microenvironment, the B cell receptor (BCR), which is undoubtedly the master regulator of leukemic cell behavior, plays an important role in orchestrating immune responses, as well. Lastly, local conditions of hypoxia, typical of the lymphoid niche, have major effects both on CLL cells and on non-leukemic immune cells, partly mediated through adenosine signaling, for which novel specific inhibitors are currently under development. In summary, this review will provide an overview of the molecular and microenvironmental mechanisms that modify innate and adaptive immune responses of CLL patients, focusing attention on those that may have therapeutic implications.

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Differential Effects of Microenvironmental Elements On Tumor Cells Survival in Chronic Lymphocytic Leukemia Patient Subsets with Good or Poor Prognosis.

Blood ◽

10.1182/blood.v114.22.2333.2333 ◽

2009 ◽

Vol 114 (22) ◽

pp. 2333-2333

Author(s):

Marta Coscia ◽

Francesca Pantaleoni ◽

Chiara Riganti ◽

Micol Rigoni ◽

Candida Vitale ◽

...

Keyword(s):

T Cells ◽

Chronic Lymphocytic Leukemia ◽

Tumor Cells ◽

Peripheral Blood ◽

Lymphocytic Leukemia ◽

Leukemic Cells ◽

Spontaneous Apoptosis ◽

Survival Effect

Abstract Abstract 2333 Poster Board II-310 Chronic lymphocytic leukemia (CLL) is a clinically heterogeneous disease. A very reliable prognosticator is the mutational status of the tumor immunoglobulin heavy chain variable region (IgVH): patients with unmutated (UM) IgVH have a worse prognosis than patients with mutated (M) IgVH. Soluble factors (i.e. IL-4 and CD40L) and cellular components of the local microenvironment [i.e. bone marrow stromal cells (BMSC) and nurse-like cells (NLCs)] are important survival factors for CLL B cells. It is currently unknown to what extent UM and M CLL cells depend on the local microenvironment for their survival. We have evaluated the spontaneous apoptotic rate of tumor cells isolated by immunomagnetic selection from the peripheral blood (PB) of M and UM CLL patients. Leukemic cells purified by negative selection from the PB of UM CLL patients showed significantly higher rates of spontaneous apoptosis after long-term in vitro culture as compared to CLL cells isolated from M patients. Both M and UM CLL cells showed high basal level of Bcl-2 expression and NF-kB activity soon after purification. In vitro spontaneous apoptosis of purified UM CLL cells was associated with a progressive downregulation of the intracellular expression of Bcl-2 and with a complete loss of the active nuclear form of NF-kB. On the contrary, the higher long term viability of M CLL cells was paralleled by a maintained Bcl-2 and NF-kB expression. IL-4 and CD40L, used alone or in combination, as well as murine and human BMSC were capable of rescuing UM tumor cells from apoptosis. The pro-survival effect of these stimuli was exerted through the upregulation of Bcl-2 and was totally independent from the recovery of NF-kB nuclear translocation. We observed that UM CLL cells were less susceptible to spontaneous apoptosis when cultured as unfractionated peripheral blood mononuclear cells (PBMC) as compared to purified leukemic cells. This higher cell viability was associated with a retained expression of Bcl-2 and of the nuclear form of NF-kB, thus suggesting the presence of a pro-survival element in the peripheral blood of these patients. The extremely low numbers of NLCs generated from PMBC of UM patients ruled out a role for these cells in supporting the survival of unpurified leukemic cells. Conversely, a pro-survival effect on UM CLL cells was exerted by autologous T cells. Indeed, a significant reduction in the apoptotic rate of leukemic cells was observed when purified UM cells were cultured in the presence of autologous peripheral blood T cells (PBT). The prosurvival effect of circulating T cells was particularly evident at high T:B ratio, did not require a cell-cell contact and was mediated by the upregulation of Bcl-2 and the activation of NF-kB in leukemic cells. These data indicate that the survival of UM tumor cells is highly dependent on the action of multiple microenviromental stimuli. Conversely, M cells are intrinsically more resistant to apoptosis and minimally influenced by the local microenviroment. The higher dependency of UM CLL cells from extrinsic signals might be exploited to develop new therapies targeting the tumor microenvironment and to improve the outcome of more aggressive CLL. Disclosures: No relevant conflicts of interest to declare.

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HLA ligandome analysis identifies the underlying specificities of spontaneous antileukemia immune responses in chronic lymphocytic leukemia (CLL)

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1416389112 ◽

2014 ◽

Vol 112 (2) ◽

pp. E166-E175 ◽

Cited By ~ 92

Author(s):

Daniel J. Kowalewski ◽

Heiko Schuster ◽

Linus Backert ◽

Claudia Berlin ◽

Stefan Kahn ◽

...

Keyword(s):

T Cell ◽

Chronic Lymphocytic Leukemia ◽

Immune Responses ◽

Tumor Antigens ◽

Checkpoint Inhibitors ◽

Hla Class I ◽

Lymphocytic Leukemia ◽

Leukemic Cells ◽

Immune Recognition ◽

Hla Ligandome

The breakthrough development of clinically effective immune checkpoint inhibitors illustrates the potential of T-cell–based immunotherapy to effectively treat malignancies. A remaining challenge is to increase and guide the specificities of anticancer immune responses, e.g., by therapeutic vaccination or by adoptive T-cell transfer. By analyzing the landscape of naturally presented HLA class I and II ligands of primary chronic lymphocytic leukemia (CLL), we delineated a novel category of tumor-associated T-cell antigens based on their exclusive and frequent representation in the HLA ligandome of leukemic cells. These antigens were validated across different stages and mutational subtypes of CLL and found to be robustly represented in HLA ligandomes of patients undergoing standard chemo-/immunotherapy. We demonstrate specific immune recognition of these antigens exclusively in CLL patients, with the frequencies of representation in CLL ligandomes correlating with the frequencies of immune recognition by patient T cells. Moreover, retrospective survival analysis revealed survival benefits for patients displaying immune responses to these antigens. These results directly imply these nonmutant self-peptides as pathophysiologically relevant tumor antigens and encourages their implementation for cancer immunotherapy.

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Autologous and allogeneic stem cell transplantations for poor-risk chronic lymphocytic leukemia

Blood ◽

10.1182/blood-2005-05-1778 ◽

2005 ◽

Vol 106 (13) ◽

pp. 4389-4396 ◽

Cited By ~ 162

Author(s):

John G. Gribben ◽

David Zahrieh ◽

Katherine Stephans ◽

Lini Bartlett-Pandite ◽

Edwin P. Alyea ◽

...

Keyword(s):

Stem Cell ◽

High Risk ◽

Chronic Lymphocytic Leukemia ◽

Human Leukocyte ◽

Progression Free Survival ◽

Lymphocytic Leukemia ◽

Hematopoietic Stem ◽

Free Survival ◽

Matched Sibling

We report here on the long-term follow-up on 162 patients with high-risk chronic lymphocytic leukemia (CLL) who have undergone hematopoietic stem cell transplantation (SCT) at a single center from 1989 to 1999. Twenty-five patients with human leukocyte antigen (HLA)-matched sibling donors underwent T-cell-depleted allogeneic SCT, and 137 patients without HLA-matched sibling donors underwent autologous SCT. The 100-day mortality was 4% for both groups, but later morbidity and mortality were negatively affected on outcome. Progression-free survival was significantly longer following autologous than allogeneic SCT, but there was no difference in overall survival and no difference in the cumulative incidence of disease recurrence or deaths without recurrence between the 2 groups. At a median follow-up of 6.5 years there is no evidence of a plateau of progression-free survival. The majority of patients treated with donor lymphocyte infusions after relapse responded, demonstrating a significant graft-versus-leukemia effect in CLL. From these findings we have altered our approach for patients with high-risk CLL and are currently exploring the role of related and unrelated allogeneic SCT following reduced-intensity conditioning regimens.

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Humoral Immune Responses Against the Oncofetal-Antigen/Immature Laminin Receptor (OFA/iLR) in Patients with Chronic Lymphocytic Leukemia.

Blood ◽

10.1182/blood.v108.11.2820.2820 ◽

2006 ◽

Vol 108 (11) ◽

pp. 2820-2820

Author(s):

Birte Friedrichs ◽

Sandra Siegel ◽

Norbert Schmitz ◽

Matthias Zeis

Keyword(s):

Chronic Lymphocytic Leukemia ◽

Immune Responses ◽

Progression Free Survival ◽

Lymphocytic Leukemia ◽

Laminin Receptor ◽

Enzyme Linked Immunosorbent Assay ◽

Humoral Immune ◽

Humoral Immune Responses ◽

B Cell Subsets

Abstract The 37 kD oncofetal antigen/immature laminin receptor (OFA/iLR) is a strongly overexpressed tumor antigen on malignant cells of numerous tumor entities including several hematological malignancies but it is not present on the cell surface of normal differentiated tissues. OFA/iLR is widely expressed on chronic lymphocytic leukemia (CLL) cells while absent on different normal B-cell subsets. The aim of this study was to evaluate and characterize humoral immune responses towards OFA/iLR in patients with CLL. 38 healthy individuals and 68 untreated patients with chronic lymphocytic leukemia were analysed for the presence of anti-OFA/iLR-antibodies. Sera were screened in an enzyme-linked immunosorbent assay (ELISA) for immunoglobulin G (IgG) and IgM anti-OFA/iLR-antibodies. Detectable IgG or IgM responses to OFA protein were present in 32 of 68 patients (47,0%) but only in 4 of 38 (10,5%) healthy donors. IgG subtype analysis revealed a predominant IgG1 and IgG3 response. Utilizing 42 peptides deduced from the complete OFA/iLR amino acid sequence, 24 (35,3%) samples with significant anti-OFA/iLR IgG and/or IgM titers were also reactive with at least one OFA/iLR epitope. Patient-derived anti-OFA/iLR antibodies were capable of recognizing and selectively killing OFA/iLR expressing CLL cells in complement-mediated and antibody-dependent cellular cytotoxicity (ADCC) assays. Kaplan-Meier plots for progression-free survival (PFS) revealed a tendendy for longer PFS in patients with detectable humoral responses compared patients with negative ELISA (p=0,0165). In addition, sera from eight CLL patients who had undergone allogeneic hematopoetic stem cell transplantion (allo-HSCT) were analysed. Six out of eight patients showed high values for IgG or IgM anti-OFA/iLR-antibodies after allo-HSCT as long as remaining in complete remission suggesting a potential role of anti-OFA/iLR-directed Graft-versus-Leukemia effects. For the first time, these data suggest that anti-OFA/iLR antibodies might be involved in the immunological control of OFA/iLR expressing CLL cells in vivo.

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Prognostic Relevance of CD49d Expression On B Leukemic Cells in Chronic Lymphocytic Leukemia. Meta-Analysis of Published and unpublished Individual Data From 3146 Patients

Blood ◽

10.1182/blood.v120.21.3871.3871 ◽

2012 ◽

Vol 120 (21) ◽

pp. 3871-3871

Author(s):

Pietro Bulian ◽

Tait D. Shanafelt ◽

Chris Pepper ◽

Chris Fegan ◽

Giovanni Del Poeta ◽

...

Keyword(s):

Overall Survival ◽

Chronic Lymphocytic Leukemia ◽

Research Funding ◽

Prognostic Value ◽

Meta Analysis ◽

Hazard Ratio ◽

Lymphocytic Leukemia ◽

Leukemic Cells ◽

Individual Data ◽

End Point

Abstract Abstract 3871 Background. A number of investigators have provided data supporting the value of CD49d expression on B leukemic cells in chronic lymphocytic leukemia (CLL) as independent prognostic variable. These studies used a variety of clinical end points including overall survival (OS), time to treatment (TTT) or treatment free survival (TFS). The factors included in multivariate analyses of these studies also differed. Unresolved issues regarding the prognostic value of CD49d assessment in CLL included the choice of the optimal cut-off to define positivity and CD49d prognostic value in patients subsets defined by other standard prognostic factors. Aim. To perform meta-analysis using individual patient level data from studies of CD49d expression to evaluate its ability to predict OS (primary end-point) and TTT/TFS (secondary end-point). Methods. Studies published by 30 April 2011, reporting an association of high CD49d expression on B CLL cells, measured by flow cytometry, and end-points were identified by Medline search. Additionally, we performed a manual review of abstracts presented at the congress of the American Society of Hematology from 2006 to 2010. CD49d was used as a categorical variable, as coded in original studies. Results. We identified 6 published studies and one abstract for inclusion. All authors agreed to provide individual data on the patients in these publications as well as unpublished data on additional patients to be used for replication analysis. Four authors also submitted updated follow-up data. We collected the following variables: date of diagnosis, OS, TTT/TFS, CD49d, CD38, ZAP-70, immunoglobulin mutational (IGHV) status, del17p and del11q chromosomal aberrations, age, stage, ALC, and β2 microglobulin concentration. Data from 3146 individual patients was available with 261 subsequently excluded due to missing end point and/or CD49d data. Of 2771 patients with valid data, 1405 (51%) were included in the previous publications and 1366 (49%) were unpublished. Before starting analyses a decision was made to perform meta-analysis on published data and use data from previously unpublished data as a validation cohort. Pooled CD49d hazard ratio for OS was 2.62 (1.88–3.64). In bivariate analysis, the prognostic value of CD49d was confirmed and of comparable value in patients subsets defined by CD38 and ZAP-70 expression, IGHV status, unfavorable chromosomal aberrations. Finally, we performed a multivariate analysis including CD49d, CD38, ZAP-70, IGHV status, del17p and del11q. CD49d was significantly associated with shorter overall survival in this adjusted model, with a hazard ratio of 2.47(1.17–5.21). Inspection of Martingale residuals plots of CD49d in each study failed to show a recognizable cut-point. CD49d cut-points previously adopted in published studies (30% and 45%) were subjected to validation in the cohort of 1366 unpublished patients. The Cox model with 45% cut-off had a slight greater hazard ratio (2.73 vs 2.65, log-rank p<0.0001). Only 4% of patients changed prognostic category after swapping the cut-off from 45% to 30%. Conclusions. Preliminary results of a meta-analysis using individual patient data from >1400 patients confirm the association of high CD49d expression with short OS independent of other prognostic parameters. While the 45% cut-off has a marginal better prognostic power, the 30% cut-off has the advantage of being already in use for CD38 and generally adopted for other surface antigens in chronic leukemia immunophenotyping. These findings may have implication for patient's stratification in future prospective studies and potential therapeutic efforts to target CD49d or CD49d signaling. Disclosures: Shanafelt: Genentech: Research Funding; Glaxo-Smith-Kline: Research Funding; Cephalon: Research Funding; Hospira: Research Funding; Celgene: Research Funding; Polyphenon E International: Research Funding. Burger:Pharmacyclics: Consultancy, Research Funding.

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