Effects Of Bendamustine Plus Rituximab On The Distribution Of Normal Peripheral Blood Leucocyte Populations In Advanced-Stage Chronic Lymphocytic Leukemia (CLL)

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 5289-5289 ◽  
Author(s):  
Georgiana Grigore ◽  
Martin Perez-Andres ◽  
Susana Barrena ◽  
Rosa Ana Rivas ◽  
Marcos González ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Plasma Cells ◽  
Memory B Cells ◽  
Lymphocytic Leukemia ◽  
Cd4 T Cell ◽  
Advanced Stage ◽  
Time Point

Abstract Introduction Management of B-cell chronic lymphocytic leukemia (CLL) is currently undergoing profound changes. Accordingly, new treatment options with an expected less toxicity than standard regimens are been explored. Recent results show that chemoimmunotherapy may improve the life expectancy of CLLpatients and has proven to be more efficient than chemotherapy alone in depleting malignant cells. Despite its efficacy, little is known about its precise immunomodulatory effects. Aim To evaluate the effects of chemoimmunotherapy with bendamustine plusrituximab (BR) on the distribution of normal residual leucocyte populations in peripheral blood (PB) from advanced-stage CLL patients, with special emphasis on maturation-associated B-cell subsets (immature, naïve, memory IgM/IgG/IgA and plasma cells). Material and Methods Distribution of PB neoplastic cells and residual normal immune cell subpopulations were analyzed in 72 CLL patients with advanced disease (Binet B/C), before therapy (M0) and after 1 course of BR (M1). The same analysis was repeated 3 months after completing treatment (M3) in 31/72 patients. PB leucocyte cell subsets were identified at each time-point by 8-color flow cytometry with monoclonal antibody reagents against CD3, CD4, CD5, CD8, TCRgd, CD19, CD20, CD27, CD38, CD45, CD56, sIgM, sIgA, sIgG, sIgLambda and sIgKappa. Results After the first BR course, absolute counts of all PB myeloid subsets were significantly decreased as compared to time M0, including neutrophils (2,744±1,830 vs 4,764±2,906 cells/uL, p<0.001), eosinophils (132±185 vs 215±245 cells/uL; p<0.001), basophils (37±28 vs 59±47 cells/uL, p<0.001), monocytes (334±280 vs 504±424 cells/uL, p=0.001) and dendritic cells (DCs, 41±40 vs 89±168 cells/uL, p=0.02), as well as NK cells (120±147 vs 550±599 cells/uL, p<0.001). At M3, all these populations remained decreased when compared to M0, but at similar levels to M1 (except for the absolute number of DCs, found to be increased vs. M1 -74±46 vs 41±40 cells/uL, p=0.008- and closer to M0). In turn, total T cells were reduced in M1 as compared to M0 values (818±655 vs 3,905±2,375 cells/uL, p<0.001), due to decreased numbers of CD4+ (424±376 vs 1,573±1,204 cells/uL, p<0.001), CD8+ (342±330 vs 1,334±1,218 cells/uL, p<0.001) and TCRgd (21±28 vs 141±289 cells/uL, p=0.001) T cells, leading to an increased CD4/CD8 ratio (1.8±1.3 vs 1.4±0.8, p=0.004). Also, decreased levels of CD4 (222±156 cells/uL), CD8 (501±544 cells/uL) and TCRgd (21±40 cells/uL) T cells were observed at time M3 vs. baseline values. No changes (p>0.05) were observed for CD8 and TCRgd for M3 vs. M1, while CD4+ T-cell numbers were significantly reduced (p=0.006), resulting in an inverted CD4/CD8 ratio (0.9±1.0 vs. 1.8±1.3, p=0.005) at the M3 time-point. As regards B cells, the absolute count of both neoplastic and normal B lymphocytes were significantly decreased at time M1 vs. M0 (3,363±9,353 vs 53,521±56,602 CLL cells/uL and 2±6 vs 58±107 normal B-cells/uL, p=0.006 and p<0.001, respectively). Within the normal residual B-cell compartment, we found significantly decreased numbers of immature (0.07±0.22 vs 6.55±21.64 cells/uL, p=0.01) and memory (1.3±14.7 vs 35.1±43.6 cells/uL, p<0.001) B cells -including sIgM (0.5±2.3 vs 14.5±24.8 cells/uL, p<0.001), sIgG (0.2±1.0 vs 11.5±17.2 cells/uL; p<0.001) and sIgA (0.6±3.1 vs 9.5±12.5 cells/uL, p<0.001) memory B cells-. At time M3, decreased (p<0.01) naïve (0.46±2.58 cells/uL) and memory B-cells (1.34±6.75 cells/uL), including IgM (0.46±2.58 cells/uL), IgG (0.34±1.69 cells/uL) and IgA (0.09±0.31 cells/uL), but not immature cells (2.28±8.84 cells/uL, p=0.9), were observed as compared to time M0. Differences did not reach statistical significance when comparing M3 vs. M1. The number of circulating plasma cells did not significantly vary during treatment. Conclusions All PB leucocyte subsets are affected by BR treatment in advanced-stage CLL. Interestingly, at time M3 the CD4+ T-cell subset continues to be decreased, while the other T-cell compartments seem to remain stable. Also, normal B cells are affected by BR treatment, and the depletion induced after one course therapy is maintained even three months after finishing BR therapy, except for immature B cells, that seem to be the first to recover in PB. Further studies will offer a more accurate insight into the biology of cell recovery during and after BR therapy in CLL patients. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Potential anti-EBV effects associated with elevated interleukin-21 levels: a case report

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Kristian Assing ◽  
Christian Nielsen ◽  
Marianne Jakobsen ◽  
Charlotte B. Andersen ◽  
Kristin Skogstrand ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Plasma Cell ◽  
Germinal Center ◽  
Plasma Cells ◽  
Cell Formation ◽  
Memory B Cells ◽  
Memory B Cell

Abstract Background Germinal center derived memory B cells and plasma cells constitute, in health and during EBV reactivation, the largest functional EBV reservoir. Hence, by reducing germinal center derived formation of memory B cells and plasma cells, EBV loads may be reduced. Animal and in-vitro models have shown that IL-21 can support memory B and plasma cell formation and thereby potentially contribute to EBV persistence. However, IL-21 also displays anti-viral effects, as mice models have shown that CD4+ T cell produced IL-21 is critical for the differentiation, function and survival of anti-viral CD8+ T cells able to contain chronic virus infections. Case presentation We present immunological work-up (flow-cytometry, ELISA and genetics) related to a patient suffering from a condition resembling B cell chronic active EBV infection, albeit with moderately elevated EBV copy numbers. No mutations in genes associated with EBV disease, common variable immunodeficiency or pertaining to the IL-21 signaling pathway (including hypermorphic IL-21 mutations) were found. Increased (> 5-fold increase 7 days post-vaccination) CD4+ T cell produced (p < 0.01) and extracellular IL-21 levels characterized our patient and coexisted with: CD8+ lymphopenia, B lymphopenia, hypogammaglobulinemia, compromised memory B cell differentiation, absent induction of B-cell lymphoma 6 protein (Bcl-6) dependent peripheral follicular helper T cells (pTFH, p = 0.01), reduced frequencies of peripheral CD4+ Bcl-6+ T cells (p = 0.05), compromised plasmablast differentiation (reduced protein vaccine responses (p < 0.001) as well as reduced Treg frequencies. Supporting IL-21 mediated suppression of pTFH formation, pTFH and CD4+ IL-21+ frequencies were strongly inversely correlated, prior to and after vaccination, in the patient and in controls, Spearman’s rho: − 0.86, p < 0.001. Conclusions To the best of our knowledge, this is the first report of elevated CD4+ IL-21+ T cell frequencies in human EBV disease. IL-21 overproduction may, apart from driving T cell mediated anti-EBV responses, disrupt germinal center derived memory B cell and plasma cell formation, and thereby contribute to EBV disease control.

scholarly journals Activation of Virus-specific Memory B Cells in the Absence of T Cell Help

2004 ◽  
Vol 199 (4) ◽  
pp. 593-602 ◽  
Author(s):  
Barbara J. Hebeis ◽  
Karin Klenovsek ◽  
Peter Rohwer ◽  
Uwe Ritter ◽  
Andrea Schneider ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cd4 T Cells ◽  
Plasma Cells ◽  
Human Herpesvirus ◽  
Memory B Cells ◽  
Specific Memory ◽  
T Cell Help

Humoral immunity is maintained by long-lived plasma cells, constitutively secreting antibodies, and nonsecreting resting memory B cells that are rapidly reactivated upon antigen encounter. The activation requirements for resting memory B cells, particularly the role of T helper cells, are unclear. To analyze the activation of memory B cells, mice were immunized with human cytomegalovirus, a complex human herpesvirus, and tick-born encephalitis virus, and a simple flavivirus. B cell populations devoid of Ig-secreting plasma cells were adoptively transferred into T and B cell–deficient RAG-1−/− mice. Antigenic stimulation 4–6 d after transfer of B cells resulted in rapid IgG production. The response was long lasting and strictly antigen specific, excluding polyclonal B cell activation. CD4+ T cells were not involved since (a) further depletion of CD4+ T cells in the recipient mice did not alter the antibody response and (b) recipient mice contained no detectable CD4+ T cells 90 d posttransfer. Memory B cells could not be activated by a soluble viral protein without T cell help. Transfer of memory B cells into immunocompetent animals indicated that presence of helper T cells did not enhance the memory B cell response. Therefore, our results indicate that activation of virus-specific memory B cells to secrete IgG is independent of cognate or bystander T cell help.

scholarly journals Human T cell hybridomas secreting factors for IgA-specific help, polyclonal B cell activation, and B cell proliferation.

1982 ◽  
Vol 156 (6) ◽  
pp. 1860-1865 ◽  
Author(s):  
L Mayer ◽  
S M Fu ◽  
H G Kunkel
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
Plasma Cells ◽  
Lymphocytic Leukemia ◽  
Pokeweed Mitogen ◽  
Human T Cell

Human T-T hybridomas were established by fusion of concanavalin A-activated OKT-4+ T cells with hypoxanthine guanine phosphoribosyl transferase-deficient as well as nondeficient T cell lines. Four hybrids were selected for further study. Supernatant from hybrid clone J1.3 specifically enhanced IgA production and secretion by isolated human B cells, with increases in IgA plaque-forming cells approaching those seen with addition of autologous T cells and pokeweed mitogen. A monoclonal lymphocytic leukemia with membrane IgA also differentiated to IgA plasma cells by this supernatant. Evidence suggests that this hybrid supernatant acts on post-switch IgA-committed B cells. The other hybrids were not isotype specific; hybrid J2S1 enhanced polyclonal Ig secretion and hybrids K1 and K8 induced B cell proliferation without induction of Ig secretion.

Requirements for Co-Stimulation in T-Cell Dependent and T-Cell Independent Re-Stimulation of FVIII-Specific Memory B Cells

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 238-238 ◽  
Author(s):  
Aniko Ginta Pordes ◽  
Christina Hausl ◽  
Peter Allacher ◽  
Rafi Uddin Ahmad ◽  
Eva M Muchitsch ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cd4 T Cells ◽  
Plasma Cells ◽  
Memory B Cells ◽  
Specific Memory ◽  
Stimulation Of

Abstract Memory B cells specific for factor VIII (FVIII) are critical for maintaining FVIII inhibitors in patients with hemophilia A. They are precursors of anti-FVIII antibody-producing plasma cells and are highly efficient antigen-presenting cells for the activation of T cells. The eradication of FVIII-specific memory B cells will be a prerequisite for any successful new approach to induce immune tolerance in patients with FVIII inhibitors. Little is known about the regulation of these cells. Previously we showed that ligands for toll-like receptors (TLR) 7 and 9 are able to re-stimulate FVIII-specific memory B cells in the absence of T-cell help. However, alternative “helper cells” such as dendritic cells are essential for providing help to memory B cells under such conditions. Based on these findings, we asked which co-stimulatory interactions are required for the restimulation of memory B cells in the presence of dendritic cells and ligands for TLR and whether these co-stimulatory interactions are the same as those required for the restimulation of memory B cells in the presence of activated T cells. We used spleen cells from hemophilic mice treated with human FVIII to generate highly purified populations of memory B cells, CD4+ T cells and dendritic cells. The required purity was achieved by a combination of magnetic bead separation and fluorescence-activated cell sorting. The memory B cell compartment was specified by the expression of CD19 together with IgG and the absence of surface IgM and IgD. Memory B cells were cultured in the presence of FVIII to stimulate their differentiation into anti-FVIII antibody-producing plasma cells. Different combinations of CD4+ T cells, ligands for TLR 7 and 9 and dendritic cells were added to the memory-B-cell cultures. Blocking antibodies and competitor proteins were used to specify the co-stimulatory interactions required for the re-stimulation of memory B cells in the presence of either CD4+ T cells or dendritic cells and ligands for TLR 7 and 9. Our results demonstrate that the blockade of B7-1 and B7-2 as well as the blockade of CD40L inhibit the re-stimulation of FVIII-specific memory B cells and their differentiation into anti-FVIII antibody-producing plasma cells in the presence of T-cell help. Similar requirements apply for the re-stimulation of memory B cells in the presence of dendritic cells and ligands for TLR 7 or 9. Dendritic cells in the absence of ligands for TLR are not able to provide help for the re-stimulation of memory B cells, which indicates that dendritic cells need to be activated. Furthermore, ligands for TLR 7 or 9 were not able to re-stimulate memory B cells in the complete absence of dendritic cells. Based on these results we conclude that dendritic cells activated by ligands for TLR 7 or 9 can substitute for activated CD4+ T cells in providing co-stimulatory help for memory-B-cell re-stimulation. CD40-CD40L interactions seem to be the most important co-stimulatory interactions for the re-stimulation of memory B cells, not only in the presence of activated CD4+ T cells but also in the presence of ligands for TLR and dendritic cells.

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.

Vaccine-elicited CD4 T cells prevent the deletion of antiviral B cells in chronic infection

2021 ◽  
Vol 118 (46) ◽  
pp. e2108157118
Author(s):  
Kerstin Narr ◽  
Yusuf I. Ertuna ◽  
Benedict Fallet ◽  
Karen Cornille ◽  
Mirela Dimitrova ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cd4 T Cells ◽  
Memory B Cells ◽  
Type I ◽  
Clonal Deletion ◽  
Cell Immunity ◽  
B Cell Immunity

Chronic viral infections subvert protective B cell immunity. An early type I interferon (IFN-I)–driven bias to short-lived plasmablast differentiation leads to clonal deletion, so-called “decimation,” of antiviral memory B cells. Therefore, prophylactic countermeasures against decimation remain an unmet need. We show that vaccination-induced CD4 T cells prevented the decimation of naïve and memory B cells in chronically lymphocytic choriomeningitis virus (LCMV)-infected mice. Although these B cell responses were largely T independent when IFN-I was blocked, preexisting T help assured their sustainability under conditions of IFN-I–driven inflammation by instructing a germinal center B cell transcriptional program. Prevention of decimation depended on T cell–intrinsic Bcl6 and Tfh progeny formation. Antigen presentation by B cells, interactions with antigen-specific T helper cells, and costimulation by CD40 and ICOS were also required. Importantly, B cell–mediated virus control averted Th1-driven immunopathology in LCMV-challenged animals with preexisting CD4 T cell immunity. Our findings show that vaccination-induced Tfh cells represent a cornerstone of effective B cell immunity to chronic virus challenge, pointing the way toward more effective B cell–based vaccination against persistent viral diseases.

scholarly journals Induction of human IgE synthesis by CD4+ T cell clones. Requirement for interleukin 4 and low molecular weight B cell growth factor.

1989 ◽  
Vol 170 (5) ◽  
pp. 1477-1493 ◽  
Author(s):  
R H DeKruyff ◽  
T Turner ◽  
J S Abrams ◽  
M A Palladino ◽  
D T Umetsu
Keyword(s):  
Molecular Weight ◽  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cd4 T Cell ◽  
Low Molecular Weight ◽  
Cell Clones ◽  
B Cell Growth Factor ◽  
Ige Synthesis

We have analyzed in detail the precise requirements for the induction of human IgE synthesis using several experimental approaches with purified B cells and well-characterized alloantigen-specific CD4+ T cell clones expressing different profiles of lymphokine secretion. Using these clones under cognate conditions in which the B cells expressed alloantigens recognized by the cloned T cells, we have confirmed that IL-4 is required for the induction of IgE synthesis, but we have clearly demonstrated that IL-4 by itself is not sufficient. With several cloned CD4+ T cell lines, including an IL-4-producing clone that could not induce IgE synthesis, and cloned T cells pretreated with cyclosporin A to inhibit lymphokine synthesis, we showed that Th cell-B cell interactions are necessary for IgE synthesis, and that low molecular weight B cell growth factor (LMW-BCGF) and IL-4, in combination, are lymphokines of major importance in the induction of IgE synthesis. Together our results indicate that optimal induction of an IgE-specific response requires the exposure of B cells to a particular complex of signals that include (a) a signal(s) involving Th-B cell interaction that primes B cells to receive additional signals from soluble lymphokines, (b) a specific B cell proliferative signal provided by LMW-BCGF, and (c) a specific B cell differentiation signal provided by IL-4.

scholarly journals Ectopic Lymphoid Follicles in Multiple Sclerosis: Centers for Disease Control?

2020 ◽  
Vol 11 ◽  
Author(s):  
Austin Negron ◽  
Olaf Stüve ◽  
Thomas G. Forsthuber
Keyword(s):  
Multiple Sclerosis ◽  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
T Cell Responses ◽  
Memory B Cells ◽  
Lymphoid Follicles ◽  
Cell Responses ◽  
B Cell Responses

While the contribution of autoreactive CD4+ T cells to the pathogenesis of Multiple Sclerosis (MS) is widely accepted, the advent of B cell-depleting monoclonal antibody (mAb) therapies has shed new light on the complex cellular mechanisms underlying MS pathogenesis. Evidence supports the involvement of B cells in both antibody-dependent and -independent capacities. T cell-dependent B cell responses originate and take shape in germinal centers (GCs), specialized microenvironments that regulate B cell activation and subsequent differentiation into antibody-secreting cells (ASCs) or memory B cells, a process for which CD4+ T cells, namely follicular T helper (TFH) cells, are indispensable. ASCs carry out their effector function primarily via secreted Ig but also through the secretion of both pro- and anti-inflammatory cytokines. Memory B cells, in addition to being capable of rapidly differentiating into ASCs, can function as potent antigen-presenting cells (APCs) to cognate memory CD4+ T cells. Aberrant B cell responses are prevented, at least in part, by follicular regulatory T (TFR) cells, which are key suppressors of GC-derived autoreactive B cell responses through the expression of inhibitory receptors and cytokines, such as CTLA4 and IL-10, respectively. Therefore, GCs represent a critical site of peripheral B cell tolerance, and their dysregulation has been implicated in the pathogenesis of several autoimmune diseases. In MS patients, the presence of GC-like leptomeningeal ectopic lymphoid follicles (eLFs) has prompted their investigation as potential sources of pathogenic B and T cell responses. This hypothesis is supported by elevated levels of CXCL13 and circulating TFH cells in the cerebrospinal fluid (CSF) of MS patients, both of which are required to initiate and maintain GC reactions. Additionally, eLFs in post-mortem MS patient samples are notably devoid of TFR cells. The ability of GCs to generate and perpetuate, but also regulate autoreactive B and T cell responses driving MS pathology makes them an attractive target for therapeutic intervention. In this review, we will summarize the evidence from both humans and animal models supporting B cells as drivers of MS, the role of GC-like eLFs in the pathogenesis of MS, and mechanisms controlling GC-derived autoreactive B cell responses in MS.

Lenalidomide Promotes The Expansion Of CD8 T Cells With An Effector Memory Phenotype In a Murine Xenograft Model Of Chronic Lymphocytic Leukemia

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 119-119
Author(s):  
Rita Simone ◽  
Sonia Marsilio ◽  
Piers E.M. Patten ◽  
Gerardo Ferrer ◽  
Shih-Shih Chen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
T Lymphocytes ◽  
B Cell ◽  
Xenograft Model ◽  
Lymphocytic Leukemia ◽  
Effector Memory ◽  
Cell Engraftment

Abstract Lenalidomide (Revlimid®), a thalidomide analogue, is an orally administered second generation immunomodulator with anti-angiogenic and anti-neoplastic properties. Initial studies treating patients with chronic lymphocytic leukemia (CLL) suggest that lenalidomide can have considerable efficacy and that its mode of action is mainly indirect, affecting non-malignant cells in the microenvironment, in particular T lymphocytes. Because a recently described xenograft model for CLL has highlighted the importance of CLL-derived, autologous T cells in promoting leukemic B-cell engraftment and growth in vivo, we have studied the influence of lenalidomide on the expansion of CLL B- and T-lymphocytes in this model. After an initial 12 day culture of FACS-isolated CLL-derived T cells with or without anti-CD3/CD28 beads plus IL-2 (30 IU/ml), T lymphocytes were transferred into alymphoid NSG mice via the retro-orbital plexus (day 0). On day 7, CLL cells were delivered retro-orbitally. These recipient animals are referred to as “T + PBMC mice”. Mice that did not receive T cells on day 0 but were given CLL PBMCs at day 7, with or without lenalidomide, served as controls (“PBMC only mice”). Recipient mice received lenalidomide (10mg/kg/day) or vehicle control daily by gavage starting at day 0. All mice were sacrificed at day 28 (28 days after T-cell and 21 days after B-cell transfer), and blood, spleen, and bone marrow were collected. On this material, four analyses were performed: [1] level of human CD45+ cell engraftment; [2] numbers and types of CLL-derived T cells; [3] numbers of CLL B cells; and [4] levels of cytokines reflective of Th1 and Th2 immune responses. There was a clear enhancement in human hematopoietic (CD45+) cell engraftment in those mice exposed to lenalidomide. This was most marked for the PBMC only mice (vehicle: 10.64%; lenalidomide: 38.53%), although it was also evident for T + PBMC mice (vehicle: 55.96%; lenalidomide: 69.65%). T-cell phenotyping was carried out, before and after cell culture and also at sacrifice. Prior to culture, CLL samples contained on average ∼96% CD5+CD19+ cells and ∼3% CD5+CD19- cells; for the latter, ∼67% were CD4+ and ∼33% CD8+. After 12-day culture, these percentages remained largely unchanged. However, the numbers and types of T cells recovered from the spleens at sacrifice were quite different after in vivo exposure to lenalidomide. For the PBMC only, the percentages of CD4+ and CD8+ cells in the spleens differed somewhat based on lenalidomide exposure (CD4: Vehicle 86% vs. Lenalidomide 61%; CD8: Vehicle 10% vs. Lenalidomide 28%). However, this change was dramatic for the T + PBMC mice (CD4: Vehicle 64.1% vs. Lenalidomide 28.9%; CD8: Vehicle 34% vs. Lenalidomide 62%). Furthermore, when the CD8+ cells from these animals were subsetted based on antigen-experience and function, it appeared that lenalidomide exposure had led to the outgrowth of a greater number of effector memory (CD45RO+ CD62L-) than central memory (CD45RO+ CD62L+) T-cells. For CLL-derived B cells, the numbers differed, based not only on lenalidomide exposure but also on prior in vitro activation. Specifically, in PBMC only mice, the addition of lenalidomide led to increased numbers of CLL B cells in the spleen (Vehicle: 7.81% vs. Lenalidomide: 14%). Conversely, in the T + PBMC mice, the numbers of B cells decreased (Vehicle: 2.36% vs. Lenalidomide: 0.34%). An analysis of Th1 and Th2-related cytokines in the plasmas of the mice at sacrifice revealed a fall in IL-4, IL-5, and IL-10 and a marked increase in IFNg, consistent with a Th2 to Th1 transition. The above data suggest that administration of lenalidomide permits greater engraftment of human hematopoietic cells in alymphoid mice. Although this enhancement involves all members of the hematopoietic lineage, T cells, in particular CD8+ effector memory T cells, emerge in excess over time. This CD8 expansion is associated with diminished levels of CLL B cells suggesting that the decrease is due to T-cell mediated cytolysis. In contrast, in the absence of prior T-cell activation, CLL T cells appear to support better CLL B-cell growth. These findings suggest that lenalidomide alters B-cell expansion in vivo depending on the activation and differentiation state of the autologous T-cell compartment. They also implicate the generation of cytolytic T cells as one mechanism whereby lenalidomide leads to clinical improvement in CLL. Disclosures: Allen: Celgene Corporation: Honoraria.

Leukemia-associated monoclonal and oligoclonal TCR-BV use in patients with B-cell chronic lymphocytic leukemia

Blood ◽  
2003 ◽  
Vol 101 (3) ◽  
pp. 1063-1070 ◽  
Author(s):  
Mohammad-Reza Rezvany ◽  
Mahmood Jeddi-Tehrani ◽  
Hans Wigzell ◽  
Anders Österborg ◽  
Håkan Mellstedt
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Cd8 T Cells ◽  
Leukemia Cell ◽  
Lymphocytic Leukemia ◽  
Cell Chronic Lymphocytic Leukemia

Abstract T-cell receptor–B-variable (TCR-BV) gene usage and the CDR3 size distribution pattern were analyzed by reverse transcription–polymerase chain reaction (RT-PCR) in patients with B-cell chronic lymphocytic leukemia (B-CLL) to assess the T-cell repertoire. The use of TCR-BV families in CD4 and CD8 T cells stimulated with autologous activated leukemic cells was compared with that of freshly obtained blood T cells. Overexpression of individual TCR-BV families was found in freshly isolated CD4 and CD8 T cells. Polyclonal, oligoclonal, and monoclonal TCR-CDR3 patterns were seen within such overexpressed native CD4 and CD8 TCR-BV families. In nonoverexpressed TCR-BV families, monoclonal and oligoclonal populations were noted only within the CD8 subset. After in vitro stimulation of T cells with autologous leukemic B cells, analyses of the CDR3 length patterns showed that in expanded TCR-BV populations, polyclonal patterns frequently shifted toward a monoclonal/oligoclonal profile, whereas largely monoclonal patterns in native overexpressed TCR-BV subsets remained monoclonal. Seventy-five percent of CD8 expansions found in freshly obtained CD8 T cells further expanded on in vitro stimulation with autologous leukemic B cells. This suggests a memory status of such cells. In contrast, the unusually high frequency of CD4 T-cell expansions found in freshly isolated peripheral blood cells did not correlate positively to in vitro stimulation as only 1 of 9 expansions continued to expand. Our data suggest that leukemia cell–specific memory CD4 and CD8 T cells are present in vivo of patients with CLL and that several leukemia cell–associated antigens/epitopes are recognized by the patients' immune system, indicating that whole leukemia cells might be of preference for vaccine development.

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