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Distinct characteristics of lymphokine-activated killer (LAK) cells derived from patients with B-cell chronic lymphocytic leukemia (B-CLL). A factor in B-CLL serum promotes natural killer cell-like LAK cell growth.

We show that lymphokine-activated killer (LAK) cell precursors derived from patients with B-cell chronic lymphocytic leukemia (B-CLL) and cultured in the presence of recombinant interleukin-2 and normal human serum (NHS), develop into primarily NK cell-like (CD 57+) LAK cells, whereas identically prepared LAK cell precursors from normal subjects develop into mainly T cell-like (CD 3+, CD 8+) LAK cells. B-CLL LAK cells exhibited greater proliferative capacity than did normal LAK cells. When normal LAK cells were grown in B-CLL serum instead of NHS, their proliferation increased; NK cell levels also increased to those found in B-CLL LAK cells, suggesting that B-CLL serum contains a factor that promotes NK cell-like growth, LAK cells derived from normal or B-CLL patients demonstrated similar lytic activity toward K562 and Raji cells. Growth in B-CLL serum did not reduce their lytic potential. Thus, the altered phenotype and growth exhibited by B-CLL LAK cells and normal LAK cells grown in B-CLL serum does not lead to abnormalities in their cytolytic functions. We propose instead that the predominance of NK-like cells in B-CLL LAK cell populations and the presence of an NK cell-like growth factor in B-CLL serum reflect abnormalities related to NK cell-mediated B-cell regulation; ie, either inhibition of normal B-cell growth and/or growth stimulation of the leukemic clone in B-CLL.

Antigens, CD

Concomitant chronic lymphocytic leukemia (CLL) and acute myeloid leukemia. Complete remission of CLL achieved with high-dose cytosine arabinoside.

The concomitant presentation of acute myeloid leukemia (AML) and chronic lymphocytic leukemia (CLL) is rare with so far only eleven cases reported. In addition, the achievement of complete remission (CR) in CLL is exceptional and generally not assessed by immunophenotypical investigations. We report a case with a simultaneous occurrence of AML and CLL in which, in addition to the complete remission of AML, an eradication of the CLL clone was obtained following high-dose cytosine arabinoside. The immunophenotypic investigation of minimal residual disease showed that less than 1 x 10(-3) CD19+/CD5+ B-cells remained in bone marrow.

Acute Disease

Continuous DNA Methylation Deconvolution-Based Surrogate for B-Cell Differentiation State in CLL.

Chronic Lymphocytic Leukemia (CLL) is clinically divided into IGHV mutated (M-CLL) and IGHV unmutated (U-CLL) subtypes, which are thought to arise from distinct cells of origin along the B-cell differentiation pathway. We measured genome-scale DNA methylation in purified CLL samples ( n = 89) and utilized reference-based cell deconvolution techniques to develop a continuous metric of epigenetic similarity across a B-naive-like to B-memory-like scale (B-Index). B-Index accurately classifies CLL into clinical subtypes (98.8%), has a stronger epigenetic signal than IGHV gene percent identity, and demonstrates additional epigenetic signal within the M-CLL subgroup. We demonstrate that U-CLL is epigenetically more similar to B-memory than B-naive cells and reconcile previous reports of a B-naive-like epigenetic signal. The B-memory-like program of U-CLL is enriched for binding sites of transcription factors related to the germinal center activation pathway. Our findings provide epigenetic evidence for discerning CLL mechanisms of initiation and cell of origin. We also identified an epigenetic signal associated with tumor burden, which may have some relation to viral infections such as Epstein-Barr-Virus. Our cell-type deconvolution-based approach to developing a continuous metric for CLL epigenetic differentiation state can be applied to other tumors with multiple subtypes across differentiation stages.

B-memory-like

Chronic lymphocytic leukemia (CLL) terminating in multiple myeloma: report of two cases.

Two cases of multiple myeloma (MM) developed late in the course of chronic lymphocytic leukemia (CLL). An 81-yr-old white female developed, after 6 yr of CLL, IgAk MM with sheets of plasma cells abutting sheets of lymphocytes in the bone marrow, multiple pathologic fractures, and 0.26 g/24 free k light chains in the urine. A 74-yr-old white male developed, after 16 yr of CLL, k light chain MM with 20% plasma cells in the bone marrow, multiple panthologic fractures, and 3.7 g/24 hr free k light chains in the urine. In both cases the CLL had responded well to intermittent low-dose chlorambucil therapy, but the MM failed to respond to cyclic melphalanprednisone therapy. A review of 105 cases of CLL seen at the Geisinger Medical Center failed to turn up any other cases of MM developing during the course of CLL. The suggestion that there is an increased prevalence of MM in CLL is an attractive one because both diseases are B cell neoplasms and because of the increased frequency of asymptomatic monoclonal gammopathies in CLL found by others.

Aged

The leukemic B-cell population of patients with monoclonal lymphocytosis of undetermined significance (MLUS) are functionally distinct from the chronic lymphocytic leukemia (CLL) derived cell population.

Some patients with CLL survive for decades with a stable lymphocytosis without other signs of progression of the disease. This condition has been termed monoclonal lymphocytosis of undetermined significance (MLUS). The aim of the present study was to search for functional differences between the monoclonal B-cell population of CLL (n = 3) and MLUS (n = 5) patients. MLUS derived B-cell populations were susceptible to Epstein-Barr virus (EBV) infection measured as the production of EB nuclear antigen (EBNA) whereas CLL derived cells were resistant. In 4 out of 5 MLUS patients, lymphoblastoid cell line (LCL) like cell-clumps were formed, but not in CLL. The clonal B-cell population from 2 of 5 MLUS patients was immortalized by EBV (LCL restricted to the expression of one Ig light chain) while no cell line emerged from the CLL patients. Phorbol esters induced cell to cell adhesion of MLUS and normal B cells but not of CLL derived cells. This study further enlarges previous observations and strengthens the assumption that MLUS clonal B cells are functionally close to normal B cells while CLL B cells display various functional abnormalities.

Antigens, Surface

Serum levels of helper factors (IL-1 alpha, IL-1 beta and IL-6), T-cell products (sCD4 and sCD8), sIL-2R and beta 2-microglobulin in patients with B-CLL and benign B lymphocytosis.

Chronic B-lymphocytic leukemia (B-CLL) cells may be regulated by immune functions. In an attempt to analyze such functions, helper factors (IL-1 alpha, IL-1 beta and IL-6), T-cell products (sCD4 and sCD8) and sIL-2R and beta 2-microglobulin were measured in serum of patients at different stages of the disease. Patients were classified as having monoclonal lymphocytosis of undetermined significance (MLUS), stable or progressive B-CLL respectively. A significant, but modest, increase of IL-1 alpha was found in B-CLL as well as in MLUS patients whereas IL-6 levels were increased in MLUS only. sCD8 levels were increased both in MLUS and B-CLL but augmented sCD4 concentrations were found statistically significant only in progressive B-CLL. beta 2-microglobulin and sIL-2R were related to the extent of the monoclonal B-cell fraction. The data indicate an increased T-suppressor activity in both MLUS and B-CLL patients and a selective increase of helper T-cell activity in progressive B-CLL. A possible immunoregulatory influence of helper T cells on disease progression is discussed.

Adult

Cell kinetics in chronic lymphocytic leukaemia (CLL).

The fractional production rate of CLL lymphocytes, certainly in the peripheral blood and possibly in the lymph nodes, is often lower than normal. On the other hand, the absolute production in CLL blood and in lymph nodes seems to be considerably increased in most cases. Arguments for an increased lymphocyte life span in CLL, although fragmentary and dispersed, exist. The blood CLL lymphocytes, as normal lymphocytes, exchange rapidly with an extravascular pool of lymphocytes. However, recirculation of lymphocytes--from blood to blood via the lymph node and the thoracic duct--does not proceed normally in CLL. Whether this is related to the B nature of the CLL lymphocyte, to the leukaemic nature of the CLL lymphocyte or to mechanical factors--crowding of the extravascular pool--is still debatable.

Adrenal Cortex Hormones

Clonality and methylation status of the Epstein-Barr virus (EBV) genomes in in vivo-infected EBV-carrying chronic lymphocytic leukemia (CLL) cell lines.

Directly growing Epstein-Barr virus (EBV)-carrying cell lines were established from a chronic lymphocytic leukemia (CLL) patient (PG) on repeated occasions. The lines carried the same ring chromosome 15 as the leukemia cells in vivo and were similarly trisomic for chromosome 12. They all showed the same JH rearrangement, indicating that they had arisen from the same B-cell progenitor. They also had the same single EBV-terminal repeat (TR), indicating that they had been generated by a single EBV infection event. It may be surmised that a single CLL cell had been infected by EBV in vivo and established itself subsequently as a subclone within the CLL population. This subpopulation persists in vivo but does not appear to expand with time. After explantation, it transforms into lymphoblastoid cells and proliferates selectively as immortalized lines. The leukemia-representative CLL lines were phenotypically indistinguishable from the B95-8 virus-transformed normal diploid cells of the patient, established in parallel by in vitro infection. They grew as typical LCL clusters and expressed the same B-cell activation markers. The methylation status of EBV-DNA was different in the CLL lines and the B95-8-virus-transformed LCLs. When Hpall- and Mspl- digested DNA was probed with BamHI C, E, H and W fragments, the CLL lines showed a mixture of methylated and unmethylated restriction fragments as in certain EBV-carrying Burkitt lymphoma (BL) lines. In contrast, the EBV-DNA of B95-8 virus-transformed normal diploid cells was completely unmethylated, as in other LCLs.

Antigens, CD

Monoclonal antibodies against Epstein-Barr virus transformed B lymphocytes from a CLL patient.

Immunization of BALB/c mice with EBV-CLL-1 cells, derived from Epstein-Barr virus transformed B lymphocytes from a chronic lymphocytic leukemia (CLL) patient, yielded 2 monoclonal antibodies (IgG1 Kappa and IgG2a Kappa) against a membrane antigen on a subset of normal B lymphocytes and non-Hodgkin's lymphomas. Immunofluorescence revealed strong reactivity of the antibodies with EBV-CLL-1 cells and with most lymphocytes in tonsil follicles, in the intestinal wall, around splenic arterioles and near Hassall's corpuscles in the neonatal thymus as well as with a small proportion of lymphocytes in some large reactive lymph node follicles, weak reactivity with 1/5 of peripheral blood B lymphocytes (PBL), and no reactivity with platelets, granulocytes and non-lymphoid tissues. PBL from 3 CLL patients showed weak staining of only larger cells. Intense fluorescence was observed in several non-Hodgkin's lymphomas of various histological types and in Burkitt's lymphoma lines but not in the 3 T lymphoblastoid and 12 nonlymphoid tumor lines examined. The antibodies precipitated Mr 22,000 and 33,000 bands from surface labeled RAJI or EBV-CLL-1 cells and cross-competed in a binding inhibition assay. The antibodies had approximately 6 million binding sites per EBV-CLL-1 or RAJI cell but were not cytotoxic. This high antigen-density and limited expression in normal cells may permit their use for immunocytological diagnosis and targeting cytotoxic agents and radionuclides against appropriate lymphoma cells.

Animals

Increased spontaneous secretion of IL-6 from B cells of patients with B chronic lymphatic leukaemia (B-CLL) and autoimmunity.

We studied B cells from 18 patients with B-CLL, six of them with autoimmune haemolytic anaemia, for spontaneous secretion of IL-6. Our aim was to determine whether the increased incidence of autoimmune disease found in B-CLL patients is associated with enhanced spontaneous IL-6 secretion. IL-6 was measured by the effect of B cell supernatants on the proliferation of an IL-6 dependent plasmacytoma cell line T1165. The highest IL-6 values (7.4 +/- 1.8 U/ml) were measured in supernatants derived on day 3 of culture from lymphocytes of the six patients with B-CLL and concomitant autoimmune disease. The maximal IL-6 values for 10 patients with B-CLL only were 2.8 +/- 0.3 U/ml and for 10 age-matched controls, 0.8 +/- 0.3 U/ml (P less than 0.01, each group compared with the other). We conclude that there is an association between B-CLL, autoimmune disease and the spontaneous in vitro secretion of IL-6. Further studies are needed to determine whether the IL-6 secretion plays a role in the pathogenesis of autoimmune disease in patients with B-CLL.

Aged

Effect of TPA on fructose 2,6-bisphosphate levels and protein kinase C activity in B-chronic lymphocytic leukemia (B-CLL).

Normal B lymphocytes and peripheral mononuclear blood cells from B-chronic lymphocytic leukemia (B-CLL) patients were incubated in the presence of the tumor promoting phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA). In normal B lymphocytes and lymphocytes from five patients with B-CLL, TPA stimulation increased lymphocyte fructose 2,6-bisphosphate (fructose 2,6-P2) content and activity of 6-phosphofructo 2-kinase (PFK-2), which is the enzyme that catalyzes the synthesis of fructose 2,6-P2. This effect was evident after 6 h and maximal after 12-24 h of TPA exposure. In three patients, lymphocytes seemed to be refractory to TPA stimulation in the conditions described here. Lymphocyte stimulation by TPA was associated with the translocation of protein kinase C (PKC) from the soluble to the particulate membrane fraction, except in B-CLL lymphocytes refractory to the TPA effect. These results give further support to the existence within B-CLL of subsets of cells which are refractory to the stimulation by TPA and demonstrate that the tumor promoter TPA induces important metabolic changes in lymphocytes of some patients with B-CLL.

B-Lymphocytes

Signal requirements for activation of leukaemic T cells from a chronic lymphocytic leukaemia (T-CLL).

In order to define the signal requirements for leukaemic T cell activation, the proliferation and interleukin-2 (IL-2) production of peripheral lymphocytes from a patient with a HTLV-I-, CD4+, CD45RA+ CD45RO+ CD25- T-CLL were evaluated after the delivery of different stimuli. Unlike resting CD4+ normal T lymphocytes that can be activated only by a two-signal stimulation, T-CLL cells proliferated and released IL-2 in response to a pair of anti-CD2 monoclonal antibodies (MoAbs) or concanavalin A (Con A) in the absence of both accessory cells (AC) and phorbol myristate acetate (PMA). The two stimuli were also able to induce CD25 expression within 12-20 h on the majority of T-CLL cells. A response to anti-CD3 and anti-CD28 MoAbs was detected only in the presence of PMA, similar to that observed in normal resting T lymphocytes matched for phenotype. Both Con A- and CD2-induced proliferation were strongly inhibited by the addition of anti-CD25 MoAb. Furthermore, T-CLL lymphocytes acquired anti-tumour lytic activity after culture in the presence of PMA and ionomycin. We conclude that HTLV1- CD25- T-CLL can be characterized not only by morphological and phenotypical studies but also on the basis of signal requirements for cell activation.

Antibodies, Monoclonal

Analysis of VH251 gene mutation in chronic lymphocytic leukemia (CLL) and normal B-cell subsets.

B-cell chronic lymphocytic leukemia (CLL) is the malignant, monoclonal equivalent of a human CD5+ B cell. Previous studies have shown that the VH and VL genes rearranged and/or expressed in CLL have low and random mutations. In this study, however, we have found that the rearranged VH251 gene, one of the three-membered VH5 family, has extensive and selective mutations in B-CLL cells. Somatic mutation at the nucleotide level is 6.03%, and there is a high ratio of replacement to silent mutation in CDRs relative to FWRs. CDR1 mutation is particularly prevalent, and interchanges often lead to acquisition of charge. In VH251 rearranged in CD5+ and CD5- cord-blood B cells, adult peripheral-blood B cells and EBV-transformed CD5+ B-cell lines, the somatic mutation levels are much lower (0.45%, 0.93%, and 1.92%, respectively) with concomitantly lower replacement to silent ratios in CDRs relative to FWRs. The extensive and highly selective somatic mutation of VH251 used in CD5+ CLL cells strongly suggests that part of CLL is generated under the influence of antigen selection and stimulation.

B-Lymphocyte Subsets

Receptors for Helix pomatia A haemagglutinin on leukaemic lymphocytes from patients with chronic lymphocytic leukaemia (CLL).

Blood lymphocytes from thirteen patients with CLL were studied for surface-bound Ig (SIg), Fc receptors (EA rosettes), receptors for sheep erythrocytes (E rosettes) and receptors for Helix pomatia A haemagglutinin (HP), a carbohydrate-binding protein with specificity for N-acetyl-D-galactosamine and related sugars. Fluorescein-labelled HP binds to subpopulations of human peripheral blood lymphocytes (PBL) treated with neuraminidase. In normal peripheral blood, HP binds to the T-lymphocytes while the majority of the B cells bearing surface-bound immunoglobulin do not have receptors for HP. In untreated CLL, HP binds to 90-100 percent of the neuraminidase-treated PBL. Almost all of the SI-G-POSITIVE CELLS IN CLL patients also have receptors for HP. Two groups of patients were found: in one the total fraction of SIg+ cells was less than or equal to 50 percent and about 30 percent of these lost their Ig during incubation at 37 degrees C. No such loss of SIg was revealed in the remaining patients where total SIg+ fraction was approximately 70 percent. These patients usually had higher blood lymphocyte counts, probably reflecting a more advanced disease. CLL patients in remission with low numbers of leukaemic cells also had low numbers of blood lymphocytes carrying both SIg and HP-receptors. It is concluded that leukaemic cells carry both HP receptors and SIg. Testing of this combination therefore provides a valuable new tool for monitoring patients with CLL.

Aged

Lymphocyte surface immunoglobulin density and immunoglobulin secretion in vitro in chronic lymphocytic leukemia (CLL).

Lymphocyte surface immunoglobulin (SIg) and immunoglobulin (Ig) secretion were studied in 14 patients with chronic lymphocytic leukemia (CLL) and 12 healthy subjects. The determination of SIgM-bearing (SIgM+) cells by immunofluorescent staining and the quantification of SIgM by radioimmunoassay (RIA) permitted the calculation of the SIgM density. In 12 normal subjects the percentage of SIgM+ cells averaged 8% (range 4%-12%) and the SIgM density 10.2 ng antigenic equivalent/10(6) SIgM+ cells (SD 4.3). In 12 patients with CLL the respective figures were 68% (range 35%-90%) and 0.68 ng (SD 0.57). Ig secretion from pokeweed mitogen-stimulated CLL cells was markedly diminished as compared with normal lymphocytes. In coculture experiments CLL cells had no suppressive effect on Ig secretion of normal lymphocytes and normal lymphocytes did not enhance Ig secretion leukemic lymphocytes. These results indicate that the impaired secretory activity of CLL cells results from an intrinsic anomaly of these cells.

Immunoglobulins