Spontaneous resolution of p58/EB6 antigen restricted NK-type lymphoproliferative disease of granular lymphocytes: role of Epstein Barr virus infection

We describe a patient with a CD3⁻ lymphoproliferative disease of granular lymphocytes (LDGL) characterized by proliferation of CD3⁻CD16⁺ GL, restricted to the expression of p58/EB6 antigen and lacking the p58/GL183 antigen. Using PCR analysis we demonstrated the presence of EBV DNA in the peripheral blood mononuclear cells and purified CD16⁺ GL from the patient; a monoclonal episomic configuration of the virus could not be demonstrated with Southern blot analysis. The presence of EBV DNA was also detected by PCR in the serum; this finding was associated with a serological pattern consistent with a previous, already seroconverted, EBV infection. During a 4-year follow-up the lymphocytosis spontaneously disappeared; interestingly, in terms of the p58 antigen expression, we provided evidence of the reconstitution of a normal pattern of circulating NK subsets (i.e. p58/EB6⁺ p58/GL183⁻, p58/EB6⁺ p58/GL183⁺, p58/EB6⁻ p58/GL183⁻, p58/EB6⁻ p58/GL183⁺). At the time of resolution of lymphocytosis, EBV-PCR analysis still demonstrated the persistence of EBV DNA in peripheral blood mononuclear cells, but not in the patient's serum.   By indicating that inciting agents (in this case EBV) are involved in inducing the GL proliferation, our data contribute insights into the pathogenetic mechanisms accounting for in vivo GL accumulation in LDGL. It appears that a second, still unknown, event is required to determine the neoplastic transformation.     

Monoclonal proliferation of CD4+ large granular lymphocytes with cytolytic activity

Summary. A rare case of monoclonal proliferation of CD3⁺4⁺8∼ T-cell receptor-αβ⁺ large granular lymphocytes (LGL) is presented. CD4⁺ LGL in the present case showed spontaneous cytotoxicity against herpes simplex virus-infected cells and antibody- and lectin-dependent cytotoxicity. Perforin, which is one of the important cytolytic mediators of cytotoxic T cells (CTL) and natural killer cells, was abundantly expressed in CD4⁺ LGL of this case. The present case suggests that perforin-positive CD4⁺ CTL, which have recently been shown in the in vitro studies, certainly exist in vivo.     

Multidrug resistance analysis in lymphoproliferative disease of large granular lymphocytes

Multi-drug resistance (MDR) phenotype contributes to the ineffectiveness of chemotherapy. P-glycoprotein (PgP) and lung resistance protein (LRP) are proteins implicated in chemoresistance. We analysed the expression of PgP and LRP respectively in 17 and 15 cases of lymphoproliferative disease of granular lymphocytes (LDGL) including 10 cases of clonal large granular lymphocytic (LGL) leukaemia, six cases of oligoclonal ( n  = 5) and polyclonal ( n  = 1) CD3⁺ lymphoproliferation and one case of CD3⁻ NK lymphocytosis. Functional PgP activity, as determined by Rh123 dye efflux assay, was found in all the patients. The mean percentage of effluxing cells was 47 ± 22%, compared to 35 ± 8% on normal lymphocytes ( P  < 0.04). The efflux was blocked in the presence of verapamil, a PgP revertant agent. A high proportion of CD57⁺ cells (66 ± 10%) from these patients expelled Rh123. Functional PgP activity was associated with expression of MDR1 mRNA. By using immunocytochemistry, LRP expression was detected in 11/15 patients (73%). 7/10 LGL leukaemia patients presented a LRP⁺/Efflux⁺ phenotype and 5/7 had LRP⁺/Efflux⁺/MDR1 mRNA⁺ phenotype. These findings suggest that the PgP⁺/LRP⁺ phenotype is frequently observed in LDGL. Its clinical relevance in aggressive cases remains to be determined.     

Cell membrane expression and functional role of the p75 subunit of interleukin-2 receptor in lymphoproliferative disease of granular lymphocytes

The cell membrane expression and functional role of the interleukin-2 receptor (IL-2R) was analyzed in nine patients with lymphoproliferative disease of granular lymphocytes (LDGL) using monoclonal antibodies (MoAbs) specific for the p75 (TU27) and the p55 (anti-Tac) subunits of IL-2R. Four patients were characterized by the proliferation of CD3+CD8+ granular lymphocytes (GL) expressing the alpha/beta T-cell receptor (T alpha beta) and one case by the proliferation of CD3+CD4-CD8- GL expressing the gamma/delta T-cell receptor (T gamma delta); in four additional cases proliferating cells were CD3 negative GL. Consistent with data observed on normal GL, phenotypic analysis demonstrated that patients' GL lack the expression of the p55 IL-2R, whereas the p75 subunit is constitutionally expressed by expanding GL of both T-cell (either T alpha beta and T gamma delta) and natural killer (NK) origin in variable proportions (11% to 94% of cells). The analysis of the cytotoxic and proliferative activity demonstrated that the anti-p55 MoAb failed to inhibit IL-2-mediated activation, whereas a marked inhibition of both cytotoxicity and proliferation were obtained using the anti-p75 chain specific MoAb. These data indicate that the p75 chain of IL-2R is responsible for IL-2 signal transduction in both CD3+ and CD3- LDGL patients' GL.     

Epinephrine test and plasma elastase as diagnostic tools in a patient with CD3+ large granular lymphocyte proliferation

Large granular lymphocytes (LGL) proliferation is characterized by expansion of cytotoxic lymphocytes and associated with neutropenia. In a case of CD3⁺ LGL-proliferation the epinephrine stimulation test (EST) induced a striking elevation of CD3⁺, CD8⁺, CD57⁺ LGL in peripheral blood from 2.7 x 10⁹/1 to 20 x 10⁹/1 and might be an additional diagnostic tool in patients with normal or low absolute numbers of circulating LGL. After treatment with steroids, plasma elastase - a marker of neutrophil destruction - decreased from 162 to 40μg/1 (normal < 47μg/1) which correlated well with a simultaneous increase in peripheral neutrophil counts from 0.14 to 1.0 x 10⁹/1. This finding supports the hypothesis that neutropenia in CD3⁺ LGL proliferation is due to neutrophil destruction, possibly mediated by LGL.     

Upregulation of CXCR1 by proliferating cells in patients with lymphoproliferative disease of granular lymphocytes

The expression and the functional activities of different chemokine receptors (CC motif: CCR1, CCR2, CCR3, CCR5, CCR6; CXC motif: CXCR1, CXCR2, CXCR3, CXCR4, CXCR5) were investigated in 12 patients with lymphoproliferative disease of granular lymphocytes (LDGL). Six patients were characterized by the proliferation of CD3+ve GL and six patients by the expansion of CD3-ve GL. The interleukin 8 (IL-8/CXCL8) receptor CXCR1 was expressed in 12/12 patients, the CXCR4 in 6/12 patients (four CD3+ve and two CD3-ve) and the CXCR3 in 3/12 patients (one CD3+ve and two CD3-ve). CXCR1 was expressed only by proliferating GL. Other CC and CXC receptors were not expressed on proliferating GL (< 2%). In functional assays, purified GL from the patients displayed significant migration in response to specific chemokines, indicating that CXCR1, CXCR3 and CXCR4 were functionally active in these patients. In addition, a significant reduction of IL-8/CXCL8-mediated cell migration was reported in the presence of anti-CXCR1 monoclonal antibody. Our results indicate that expanding cells from patients with LDGL express specific CXCR. These data may help to define functional properties of proliferating GL in patients with LDGL and contribute toward the understanding of the complex clinical features of this disease. In particular, as CXCR1 was expressed in all of the patients studied, we speculate that abnormal expression of this receptor on proliferating GL might play a role in the pathogenesis of neutropenia, which represents a common feature in LDGL patients.     

Eosinophilia associated with proliferation of CD3+4−8−αβ+ T cells with chromosome 16 anomalies

We describe a patient with eosinophilia and an abnormal CD3⁺4⁻8⁻αβ⁺ T-cell population. Chromosomal analysis of sorted CD3⁺4⁻8⁻ cells revealed abnormal karyotypes on chromosome 16. In the presence of IL-2 the production of IL-5 from CD3⁺4⁻8⁻ cells was higher than that from CD3⁺4⁺/8⁺ cells. Eosinophil survival-enhancing activity in the patient serum was inhibited by a combination of anti-IL-5 and anti-GM-CSF monoclonal antibodies. These data suggest that increased production of IL-5 and GM-CSF from the abnormal CD3⁺4⁻8⁻ cells might cause eosinophilia.     

Clonal disease of natural killer large granular lymphocytes in Taiwan

Lymphoproliferative diseases of large granular lymphocytes (LDGL) may arise from either CD3⁺ T cells or CD3⁻ natural killer (NK) cells. LDGL with clonal proliferation of large granular lymphoeytes (LGL) is defined as LGL leukaemia. The number of patients with NK-LGL leukaemia reported is limited and the pathogenesis of the disease is not yet clear. From 1991 to 1998 six patients with cytogenetically proved clonal disease of NK-LGL were identified in our institute. All were seropositive for Epstein-Barr virus (EBV). EBV RNA or DNA could be detected in LGL from four patients by EBV in situ hybridization or Southern blot analysis. Most patients ran an aggressive clinical course and five died of the disease. Nonrandom clonal chromosomal abnormalities, including duplication of 1q, rearrangement at 3q and loss of chromosomes Y, 13 or 10, were noted in the six patients from this study and in eight from the literature. The implications of these recurrent cytogenetic aberrations in the development and progression of the disease deserve further studies.     

Generation of human natural killer cells from peripheral blood CD34+ cells mobilized by granulocyte colony-stimulating factor

We studied the generation of human natural killer (NK) cells from CD34⁺ cells that were isolated from peripheral blood stem cells (PBSC) mobilized by granulocyte colony-stimulating factor (G-CSF). The isolated CD34⁺ cells were cultured in the presence of a combination of interleukin-1 (IL-1α), IL-2, and stem cell factor for 5 weeks without marrow stroma. We found that the CD34⁺ cells isolated from G-CSF-mobilized PBSC (G-CSF/PBSC) could differentiate into a population of NK cells which were CD56^+(bright)/CD3⁻ and showed morphologic characteristics of large granular lymphocytes. Immunophenotypic analysis of the NK cells thus generated showed that a small proportion of them expressed CD2, CD8 and CD16 surface markers and approximately half of them coexpressed CD7. This NK population exhibited cytotoxic activity against a NK-sensitive cell line, K562. These observations suggest that CD34⁺ cells from G-CSF/PBSC contain precursors of NK cells that can differentiate into functional NK cells.     

Hepatic inflammatory cytokine mRNA expression in hepatitis C virus-human immunodeficiency virus co-infection

Summary.  Although epidemiologic studies have documented that hepatitis C virus (HCV)/human immunodeficiency virus (HIV) co-infected patients have accelerated fibrogenesis, especially those with CD4⁺ cell counts <200 cells/mm³, the pathogenic mechanisms are poorly understood. We investigated whether severe immunodeficiency in co-infection is associated with changes in intrahepatic inflammatory cytokine mRNA levels. We measured interferon (IFN)-γ, tumour necrosis factor-α, transforming growth factor (TGF)-β₁, interleukin (IL)-4, IL-10, IL-12p35 and IL-12p40 mRNA levels by real-time PCR performed on liver samples from HCV mono-infected ( n  = 19) and HCV/HIV co-infected ( n  = 24) patients. Co-infected patients had decreased intrahepatic mRNA levels of IFN-γ ( P  = 0.09), IL-4 ( P  = 0.05) and IL-12p35 ( P  = 0.04) compared with mono-infected patients, while IL-10 was increased ( P  = 0.07). In co-infected patients, IFN-γ mRNA levels increased linearly with increasing peripheral CD4⁺ cell counts by 1.23 times relative to the calibrator for every 100 CD4⁺ cells/mm³ increase ( P  = 0.02). No other cytokines were significantly associated with CD4⁺ cell counts. In conclusion, HIV-induced lymphopenia may result in hepatic inflammatory cytokine suppression in HCV/HIV co-infection. Intrahepatic IFN-γ levels are significantly reduced in patients with advanced immunodeficiency. Further studies are needed to assess whether decreased IFN-γ secretion by HCV-specific CD4⁺ cells may account for accelerated fibrogenesis in these patients.     

Blastogenic responses, interleukin-2 production and interleukin-2 receptor expression on CD4+ and CD8+ lymphocytes in rhesus monkeys experimentally inoculated with Loa loa

To better understand cellular responses in loiasis infection, in vitro blastogenesis of peripheral blood mononuclear cells (PBMC) to filarial antigen was assessed in 12 Loa loa -inoculated rhesus monkeys over a two-year period. Cellular reactivity to antigen was observed between 10–35 weeks postinoculation (WPI), but had declined by week 50. The roles of interleukin-2 (IL-2) and IL-2 receptor (IL-2R) expression on CD4⁺ and CD8⁺ T cells in regulating the response to antigen were examined during the initial (57 WPI) and late (92 WPI) time points of the observed diminished reactivity to antigen. The levels of IL-2 in antigen cultures at both time points were not significantly different from those in unstimulated cultures. Also, exogenous IL-2 partially reversed the PBMC response to antigen. The percentages of CD4⁺ and CD8⁺ T cells expressing IL-2R in antigen cultures at 57 WPI were not different from those of control animals. Likewise at 92 WPI, the percentage of CD4⁺ T cells expressing IL-2R in antigen cultures, were not increased above those of control animals. In contrast, the percentage of CD8⁺ T cells expressing IL-2R in antigen cultures were significantly increased above those of control animals ( P  < 0.0001), coinciding with an increase in CD8⁺ T cell numbers in these cultures. The data show that factors besides IL-2, and probably an imbalance in the percentages of CD4⁺ and CD8⁺ T cells bearing IL-2R in antigen cultures, may contribute to the diminished reactivity to antigen in L. loa -inoculated rhesus monkeys .     

Low-dose recombinant interleukin-2 therapy in advanced multiple myeloma

Summary. In vitro data have demonstrated autologous T-lymphocytes with anti-tumour activity in multiple myeloma (MM). Therefore a phase I/II trial was conducted to study the feasibility, the effect on several immunological parameters, and the tumour response induction of low-dose recombinant interleukin-2 (rIL-2) in MM patients. 18 MM patients of advanced stages in progress, who had failed on standard chemotherapy received 9 × 10⁶IU/m² rIL-2 twice daily on days 1 and 2 and 0.9 × 10⁶IU/m² twice daily for 5 subsequent days per week subcutaneously from days 3 to 56 (repeated every 12 weeks until progression). Patients were treated for between 8 and 1086+d (mean 241 d) without serious side-effects. 6/17 patients experienced tumour response (2/17 objective tumour mass reduction, 4/17 long-lasting stable disease following tumour progression before initiation of rIL-2 treatment). During therapy the number of eosinophils increased 15-fold, CD4⁺ T lymphocytes were activated as demonstrated by enhanced CD25 antigen expression, and CD56⁺ NK cells expanded in the peripheral blood. Furthermore, a diminished pre-treatment ratio of CD4⁺/CD8⁺ lymphocytes was normalized during rIL-2 treatment. NK cell activity and lymphokine activated killer (LAK) cell activity was significantly enhanced. Endogenous IL-2 production and elevated soluble IL-2 receptor serum concentrations were induced. Low-dose rIL-2 can stimulate immune enhancement in MM despite the characteristic tumour-induced immunodeficiency. The treatment has proven though limited efficacy in advanced MM. Because most of the responders experienced termination of tumour progression rather than tumour regression. rIL-2 maintenance of chemotherapy-induced remissions should be investigated.     

CD3+ CD8+ CD56− clonal large granular lymphocyte leukaemia and HIV infection

High-grade malignant lymphomas associated with HIV infection are usually derived from B lymphocytes. Although a broad spectrum of T-cell-derived malignancies has been described, no case of monoclonal T large granular lymphocyte leukaemia has been reported to date. We report a case of clonal T-LGL (CD3⁺, CD4⁻, CD8⁺, CD56⁻, CD57⁺) in an HIV-infected, HTLV1/2-negative individual. Large granular lymphocytes are thought to represent activated cytotoxic T lymphocytes. HIV infection, as previously reported for HTLV1/2, may represent a pathway of antigen activation and lead to clonal expansion of T large granular lymphocytes.     

Alloreactive CD4+ T lymphocytes can exert cytotoxicity to chronic myeloid leukaemia cells processing and presenting exogenous antigen

Existing evidence supports that CD4⁺ T lymphocytes play a role in the graft-versus-leukaemia (GVL) reaction after allogeneic bone marrow transplantation (BMT) for chronic myeloid leukaemia (CML), not only as initiators of the immune response but also as effectors of GVL. In BMT between HLA-identical pairs this CD4-mediated GVL would require CML cells to process and present antigens through MHC class II molecules. To investigate whether CML cells are capable of processing and presenting antigens, and suitable targets for CD4⁺ T-cell-mediated cytotoxicity, we generated HLA-DR1-restricted CD4⁺ cytotoxic T-cell clones that specifically recognized tuberculous purified protein derivative (PPD). We have shown that CML cells and B lymphoblastoid cell line (B-LCL) cells but not PHA-blasts from patients with CML processed exogenous antigen, PPD, and induced proliferative and cytotoxic CD4⁺ T-cell responses. Antigen presentation was blocked by antibodies to HLA-DR but not to MHC class I and by treatment with chloroquine and brefeldin. This indicates that CML cells use a classic MHC class II antigen processing pathway to present PPD antigens to CD4⁺ T cells. Cytotoxicity to CML was shown by antibody blocking studies to be mediated mainly through fas antigen. These findings indicate that donor CD4⁺ T cells alone are sufficient to mediate GVL effects following allogeneic BMT for CML.     

Bcr-Abl kinase promotes cell cycle entry of primary myeloid CML cells in the absence of growth factors

Cell cycle control of both immature and differentiated primary myeloid normal and chronic-phase chronic myeloid leukaemia (CML) cells to growth factor deprivation was studied. CD34⁺ cells were cultured in liquid culture. After removal of growth factors for 48 h normal cells were very efficiently arrested with the fraction of cells in S phase reduced by 70.8 ± 6.5% in CD34⁺ and 50.5 ± 4.2% in CD34⁻ cells. In contrast, a significantly higher proportion of leukaemic cells remained in S phase. The fraction of S-phase cells was reduced by only 29.3 ± 5.7% in CD34⁺ CML cells and 21.2 ± 3.8% in CD34⁻ cells. This abnormal negative cell cycle control in leukaemic cells was specific for growth factor deprivation. Reaction to IFN-α and TNF-α treatment was identical both in normal and CML cells. Equal quantities of the cytokines TNF-α, IL-1α, IL-1RA and IL-6 were produced by CML and normal cells. However, production of GM-CSF, with a median of 11 ± 5 pg/ml, was found only in the supernatants of CML cells. But antibodies to GM-CSF did not restore growth factor dependence of the leukaemic cells. The defect was completely corrected by the abl-specific tyrosine kinase inhibitor CGP 57148 without effecting cell cycle control of normal cells. Our results demonstrate a directly Bcr-Abl-dependent defective response of both immature and differentiated primary myeloid CML cells to growth factor deprivation.     

Expression of CD8β and alteration of cell surface phenotype in adult T-cell leukaemia cells

Typical adult T-cell leukaemia (ATL) cells have a CD4⁺CD8⁻ cell surface phenotype, but atypical phenotypes such as CD4⁺CD8⁺ and CD4⁻CD8⁺ have also been reported. The CD8 molecule is composed of α and β chains and commonly used monoclonal antibodies against CD8 molecule detect only CD8α. Since it has been reported that CD8α can be induced in mature CD4⁺ T cells by cell activation, but not CD8β, we studied whether ATL cells which express CD8α may also express CD8β. We found some cases of CD8α⁺ ATL were also positive for CD8β. Furthermore, we experienced a case whose ATL cell surface phenotype changed from CD4⁺CD8α⁺CD8β⁺ to CD4⁻CD8α⁺CD8β⁺ and finally to CD4⁺CD8α⁻CD8β⁻. Southern blot analysis revealed that the monoclonal integration of human T lymphotropic virus type I (HTLV-I) was identical throughout the course of the study, indicating that a single clone had demonstrated the alterations. These data suggest that peripheral CD4⁺CD8⁺ ATL cells can express not only CD8α, but also CD8β and that a single ATL cell clone has the potential to change its surface phenotype in vivo as well as in vitro .     

Proliferation of precursor B-lineage acute lymphoblastic leukaemia by activating the CD40 antigen

No reliable culture system exists for B-lineage acute lymphoblastic leukaemia (ALL). Recently we found that many different mature B-cell malignancies proliferate upon stimulation via the CD40 antigen, and this led us to investigate whether a similar CD40 activation on ALL cells could also induce proliferation. First, we measured CD40 expression in 21 ALL cases; all were CD40⁺, although mostly weak. Next, we triggered the CD40 antigen by anti-CD40 antibodies and by a CD40 ligand-expressing cell line. In addition, we measured the influence of IL-3, IL-4 and IL-7 with and without these stimuli.   In 8/10 cases proliferation, measured by ³H-thymidine incorporation, could be induced after CD40 crosslinking, especially in the presence of IL-3. Stimulation via the CD40 ligand was more successful than using crosslinked anti-CD40 antibodies. IL-4 inhibited the spontaneous proliferation found in three cases, but stimulated proliferation after CD40 crosslinking. IL-7 did not contribute to proliferation. Morphology, immunophenotyping and surface marker analysis, combined with DNA flow cytometry confirmed that the proliferation found could be ascribed to the ALL cells.   In conclusion, B-lineage ALL cases are CD40⁺, and many can be cultured using CD40 stimulation and IL-3.     

Cytokine and chemokine production by CD34+ haemopoietic progenitor cells: detection in single cells

In vitro expansion of haemopoietic progenitor cells (HPC), lineage-specific differentiation, and gene transfer are all based on in vitro culture systems using haemopoietic growth factors (HGF). A close control of the actual culture conditions, however, is difficult due to secondary mediators secreted by the heterogenous population of mature and immature cells in culture. Although monocytes and granulocytes have already been identified as active producers, this study specifically addressed the role of CD34⁺ progenitor cells in this respect. Using an immunostaining method that enables simultaneous detection of cytokines and phenotype, 56±6% CD34⁺ peripheral blood progenitor cells (PBPC) were found to contain cytoplasmic IL-8 after stimulation with phorbol myristate acetate+ionomycin for 90 min, 19±4% stained positive after TNF-α induction (20 h), and 7±1% expressed IL-8 in the presence of culture medium alone. Intra-cytoplasmic TNF-α and IL-1β were detected at lower frequency, and <1% of CD34⁺ cells expressed IL-1ra or IL-6, whereas IL-1α, IL-10 and G-CSF were not detected. Thus, CD34⁺ HPC are able to synthesize chemo- and cytokines that may operate in an auto- or paracrine manner to modulate in vivo as well as in vitro growth and differentation of haemopoietic cells.     

Monitoring of CD95 and CD38 expression in peripheral blood T lymphocytes during active human cytomegalovirus infection after orthotopic liver transplantation

Aim:  The aim of the present study was to quantitatively monitor the response of CD95 molecules expressed on CD3⁺ T cells (CD95⁺CD3⁺ cells) and CD38 molecules expressed on CD8⁺ T cells (CD38⁺CD8⁺ cells) to ganciclovir treatment after orthotopic liver transplant (OLT) in recipients with active human cytomegalovirus (HCMV) infection.
Methods:  Blood samples were collected from 20 liver transplanted recipients with active HCMV infection and 24 recipients without HCMV infection. CD95⁺CD3⁺ cells and CD38⁺CD8⁺ cells were quantitatively detected with QuantiBRITE bead methods by dual-color flow cytometry analysis during the post-transplantation period.
Results:  CD95⁺CD3⁺ cells and CD38⁺CD8⁺ cells were not significantly different among different ages of healthy adults ( P  > 0.05). CD95⁺CD3⁺ cells and CD38⁺CD8⁺ cells were drastically increased in the active HCMV infection group compared with that in the stable group or in the healthy group ( P  < 0.001), and then they were gradually decreased within the next several weeks after ganciclovir treatment when compared with active HCMV infection recipients ( P  < 0.001).
Conclusions:  The present study showed that CD38⁺CD8⁺ T cells can be an appropriate immunological marker for early detection and antiviral therapeutic monitoring of HCMV infection. The evaluation of CD95 molecule levels may be used routinely in clinical practice to assess the level of immunosuppression.