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F Caligaris-Cappio

Publications and source records attributed to F Caligaris-Cappio.

At least 19 recordsLinked to original sources
PubMed2006

ZAP-70 expression, as detected by immunohistochemistry on bone marrow biopsies from early-phase CLL patients, is a strong adverse prognostic factor.

Zeta-associated protein-70 (ZAP-70), mostly assessed by flow-cytometry (FC), recently emerged as reliable prognostic factor in chronic lymphocytic leukaemia (CLL) at presentation. We evaluated ZAP-70 expression in 156 CLL patients by immunohistochemistry (IHC) on formalin-fixed bone marrow (BM) biopsies at diagnosis. At presentation, 117 patients (75%) were with Binet stage A, 27 (17%) stage B and 12 (8%) stage C. Median follow-up was 61 months (range 6-242). ZAP-70 was expressed in neoplastic lymphocytes of 69 patients (44%). Concordance between ZAP-70 by IHC and ZAP-70 by FC, immunoglobulin heavy chain variable genes (IGHV) mutational status and CD38 expression was found in 41/46 (89%), 41/49 (80%) and in 60/88 (68%) tested cases, respectively. ZAP-70 expression significantly correlated with advanced Binet stage (B-C), diffuse BM infiltration, increased lactate dehydrogenase (LDH) and beta2-microglobulin serum levels and lymphocyte doubling time <12 months. ZAP-70 positivity was significantly related to poorer time to progression (median 16 months vs 158 of ZAP-70-negative cases) (P<0.0001) and overall survival (median 106 months vs not reached) (P=0.0002); this correlation was confirmed at multivariate analysis. ZAP-70 expression correlated with poorer outcome also when evaluated only in the 117 stage A patients. In conclusion, immunohistological detection of ZAP-70 on formalin-fixed BM biopsies at diagnosis appears a useful methodological approach to identify patients with poor prognosis in CLL.

ADP-ribosyl Cyclase 1↗
PubMed2006

ZAP-70 is expressed by normal and malignant human B-cell subsets of different maturational stage.

ZAP-70 tyrosine kinase is involved in signalling pathways following T-cell receptor stimulation and was originally described only in T cells and natural killer cells. ZAP-70 expression has been reported in normal mouse B lineage cells and in human malignant B lymphocytes, mainly in chronic lymphocytic leukemia (CLL) where it correlates with clinical outcome. We analyzed several B-cell lines and ex vivo malignant B cells, ranging from acute lymphoblastic leukemia to multiple myeloma and reflecting different stages of B-cell differentiation, and they showed ZAP-70 expression regardless their maturation stage. We then analyzed by Western blot and flow cytometry different human normal B-lymphocyte subpopulations: naïve, germinal center and memory B cells from tonsils, CD19+ CD5+ cells from cord blood and CD19+ lymphocytes from peripheral blood. All expressed ZAP-70 protein, though at different levels depending on their differentiation, activation and tissue localization. In addition, ZAP-70 expression levels could be modulated following stimulation via the B-cell receptor. These findings implicate a potential role of ZAP-70 in the signalling pathway of B lymphocytes at different maturational stages, indicate that ZAP-70 expression is not a CLL-specific feature among B-cell malignancies and suggest that the absence of ZAP-70 rather than its presence should be considered abnormal for malignant B lymphocytes.

Antigens, CD↗
PubMed2005

Differential effects on CLL cell survival exerted by different microenvironmental elements.

Selected microenvironmental stimuli confer to leukemic cells a growth advantage and an extended survival. We aimed at dissecting the differential support provided by the different cellular components of the microenvironment where CLL cells accumulate. To this end we cultured purified CLL cells in vitro in the presence or absence of different accessory cells (stromal cells, autologous T lymphocytes) and/or soluble molecules (IL-4, sCD40L) and assessed the leukemic cell response in terms of cell viability and chemoattracting capacity. The results indicate that both T lymphocytes and stromal cells are involved in sustaining the survival of leukemic B cells, but indicate that their support is different in terms of time of onset and duration. T cells have a short-term support activity while stromal cells provide long-term support.

B-Lymphocytes↗
PubMed2001

How immunology is reshaping clinical disciplines: the example of haematology.

Haematology represents a prime example of how rapidly immunology is moving towards the bedside. The diagnosis of blood disease has been modified by the "cluster of differentiation" (CD) nomenclature of leucocyte surface antigens, and the molecular genetics of the immune system has had a major effect on the diagnosis and treatment of blood malignancies. Lymphoid tumours represent a fertile area of interaction between immunology and haematology: B-cell malignancies are associated with dysregulation of the immune system, and antigen exposure might have an important role in the development of lymphoid malignant clones that interact with the microenvironment to avoid apoptosis and acquire better growing conditions. Understanding the pathophysiology of immune-mediated blood diseases has paved the way to the successful use of immunosuppressive agents, and the unravelling of the mechanisms of lymphocyte signal transduction and the relations between lymphocyte activation and apoptosis are allowing new therapeutic approaches. Paradoxically, lymphoid tumours are an excellent model to test the efficacy of manipulating the immune system for the purpose of tumour eradication.

Autoimmune Diseases↗
PubMed2001

Survivin is expressed on CD40 stimulation and interfaces proliferation and apoptosis in B-cell chronic lymphocytic leukemia.

In B-cell chronic lymphocytic leukemia (B-CLL), defective apoptosis causes the accumulation of mature CD5(+) B cells in lymphoid organs, bone marrow (BM), and peripheral blood (PB). These cells are the progeny of a proliferating pool that feeds the accumulating compartment. The authors sought to determine which molecular mechanisms govern the proliferating pool, how they relate to apoptosis, and what the role is of the microenvironment. To begin to resolve these problems, the expression and modulation of the family of inhibitor of apoptosis proteins (IAPs) were investigated, with consideration given to the possibility that physiological stimuli, such as CD40 ligand (CD40L), available to B cells in the microenvironment, might modulate IAP expression. The in vitro data on mononuclear cells from PB or BM of 30 patients demonstrate that B-CLL cells on CD40 stimulation express Survivin and that Survivin is the only IAP whose expression is induced by CD40L. Through immunohistochemistry, in vivo Survivin expression in lymph node (LN) and BM biopsies was evaluated. In reactive LN, Survivin was detected only in highly proliferating germinal center cells. In LN from patients with B-CLL, Survivin was detected only in pseudofollicles. Pseudofollicle Survivin(+) cells were actively proliferating and, in contrast to Survivin(+) B cells found in normal GC, were Bcl-2(+). In B-CLL BM biopsies, CD5(+), Survivin(+) cells were observed in clusters interspersed with T cells. These findings establish that Survivin controls the B-CLL proliferative pool interfacing apoptosis and that its expression may be modulated by microenvironmental stimuli.

Aged↗
PubMed2000

The indispensable role of microenvironment in the natural history of low-grade B-cell neoplasms.

Follicular lymphoma (FL) and B-cell chronic lymphocytic leukemia (B-CLL) are paradigmatic examples of lymphoid malignancies in which the relevant biological mechanisms are alterations in the control of apoptosis rather than an exaggerated proliferation. This explains why low-grade B-cell neoplasms still fail to be cured with current approaches. It is becoming increasingly clear that the defective apoptosis of FL and B-CLL has to be ascribed not only to intrinsic defects of the neoplastic cells, but also to extrinsic factors that influence their behavior. Malignant B cells retain the capacity to respond to microenvironmental signals, but have devised a monothematic responsiveness. They have a specific sensitivity to anti-apoptotic signals that favor their survival, whereas they seem to have become insensitive to pro-apoptotic signals. Bystander, nontumoral cells play a fundamental (though not sufficient) role both in the onset and in the progression of these diseases. The survival of leukemic cells appears to be dependent on direct cell-cell contacts. The localization of malignant B cells in bone marrow or neoplastic follicles is not a passive adhesion phenomenon but a crucial step for their survival. Bidirectional malignant lymphocyte-nontumoral cell interactions may lead to the amplification of a microenvironment able to inhibit the apoptosis of neoplastic B cells. The pressure of antigenic selection and the role of the tumor necrosis factor receptor family through the functional survival signal provided by CD40 together with the crippled death signal exerted by CD95 are new prominent characters on the stage.

Antigens, CD↗
PubMed2000

Biology of chronic lymphocytic leukemia.

B-cell chronic lymphocytic leukemia (CLL) lies at the cross-roads of hematology, immunology and oncology for at least three major reasons: (a) it is the prototype of human malignancies that primarily involve defects in the induction of apoptosis; (b) CLL patients develop a severe immunodeficiency with progressive hypogammaglobulinemia; and (c) they have a high prevalence of autoimmune phenomena. Recent advances in the biology of the malignant cell in CLL lead to a scenario comprised of two basic elements: first, CLL cells are optimally organized to survive in their niches because their ability to undergo apoptosis is severely hampered; second, they have a microenvironment-dependence that promotes their extended survival, a situation that arises most probably through direct cell-to-cell contacts. In addition, CLL cells themselves are the major accessory cells in CLL, but are inefficient antigen-presenting cells. This latter defect may provide a clue to reinterpret the events of immunodeficiency and autoimmunity.

Antigen-Presenting Cells↗
PubMed2000

Analysis of T-cell clones in systemic lupus erythematosus.

BACKGROUND AND OBJECTIVE: It is fairly well established that T-helper (TH)((1)) cells play a role in the pathogenesis of organ-specific autoimmune diseases, while their role and their relationship with TH((2)) cells is far from being defined in systemic lupus erythematosus (SLE). To address this issue, six female patients who fulfilled the American Rheumatism Association criteria for the diagnosis of SLE were studied. DESIGN AND METHODS: We analyzed the intracellular production of cytokines by T-cells from the peripheral blood (PB). Then, we established T-cell clones (TCC) from the peripheral blood (PB) of all cases as well as from the synovial fluid of one patient with an articular flare-up. RESULTS: The percentages of IL-4 positive and IFN-g positive PB T-cells were not different between SLE patients and normal controls. When 93 TCC (67 CD4(+), 23 CD8(+)) from the PB of 5 different SLE patients were compared to 118 TCC (94 CD4(+), 23 CD8(+)) from 5 healthy controls no statistical difference was observed between SLE and controls in terms of TH((1)), TH((2)) or TH((0)) phenotype. However, SLE clones showed a reduced ability to secrete IL-10 (p = 0. 002). In contrast, the analysis of the 30 clones obtained from synovial fluid revealed that 11/23 CD4(+) clones were TH((1)), 12/23 were TH((0)), 2/7 CD8(+ )clones were TH((1)) and 5/7 were TH((0)). No TH((2)) clones were obtained from the synovial fluid. INTERPRETATION AND CONCLUSIONS: The data suggest that the T-cell subsets operating in actively inflamed organs of SLE may belong to the TH((1)) and TH((0)) subsets.

Adolescent↗
PubMed1999

An alternatively spliced form of CD79b gene may account for altered B-cell receptor expression in B-chronic lymphocytic leukemia.

Several functional anomalies of B-chronic lymphocytic leukemia (B-CLL) cells may be explained by abnormalities of the B-cell receptor (BCR), a multimeric complex formed by the sIg homodimer and the noncovalently bound heterodimer Igalpha/Igbeta (CD79a/CD79b). Because the expression of the extracellular Ig-like domain of CD79b has been reported to be absent in the cells of most CLL cases, we have investigated the molecular mechanisms that may account for this defect. Peripheral blood lymphocytes (PBL) from 50 patients and two cell lines (MEC1, MEC2) obtained from the PBL of one of them were studied. MEC1, MEC2, and 75% of CLL cases did not express detectable levels of the extracellular Ig-like domain of CD79b, which was nevertheless present in greater than 80% CD19(+) cells from normal donors. In healthy subjects the expression of CD79b was equally distributed in CD5(+) and CD5(-) B-cell subsets. Reverse transcription-polymerase chain reaction (RT-PCR) analysis of CD79b RNA from all patients and from MEC1 and MEC2 cell lines consistently yielded two fragments of different size (709 bp and 397 bp). The 709-bp band corresponds to CD79b entire transcript; the 397-bp band corresponds to an alternatively spliced form lacking exon 3 that encodes the extracellular Ig-like domain. Both fragments were also visible in normal PBL. The expression of the 397-bp fragment was increased in normal activated B cells, while no difference was seen between CD5(+) and CD5(-) B cells. To obtain a more accurate estimate of the relative proportions of the two spliced forms, a radioactive PCR was performed in 13 normal and 22 B-CLL samples and the results analyzed using a digital imager. The mean value of the CD79b to the CD79b internally deleted ratio was 0.64 +/- 0.20 SD in normal donors and 0.44 +/- 0.27 SD in B-CLL (P =.01). Direct sequencing of 397-bp RT-PCR products and of genomic DNA corresponding to exon 3 from MEC1, MEC2, their parental cells, and five fresh B-CLL samples did not show any causal mutation. Single-strand conformation polymorphism analysis of exon 3 performed in 18 additional B-CLL cases showed a single abnormal shift corresponding to a TGT --> TGC polymorphic change at amino acid 122. We propose a role for the alternative splicing of CD79b gene in causing the reduced expression of BCR on the surface of B-CLL cells. As normal B cells also present this variant, the mechanism of CD79b posttranscriptional regulation might reflect the activation stage of the normal B cell from which B-CLL derives.

Antigens, CD↗
PubMed1999

MEC1 and MEC2: two new cell lines derived from B-chronic lymphocytic leukaemia in prolymphocytoid transformation.

We report the establishment and characterization of two cell lines, MEC1 and MEC2, that grew spontaneously on two subsequent occasions from the peripheral blood (PB) of a patient with B-chronic lymphocytic leukemia (B-CLL) in prolymphocytoid transformation. The patient was EBV-seropositive, his leukemic cells were EBNA negative, but the spontaneously grown cell lines are EBNA-2 positive. In liquid culture MEC1 cells grow adherent to the vessel wall and as tiny clumps; MEC2 cells do not adhere and form large clumps. The doubling time of MEC1 is 40h and of MEC2 is 31h. Both cell lines express the same light (kappa) and heavy chains (mu, delta) as the fresh parental B-CLL cells at the same high intensity, share the expression of mature B cell markers (CD19, CD20, CD21, CD22), differ in the expression of CD23 and FMC7, are CD11a+, CD18+, CD44+, CD49d+, CD54+ and express at high levels both CD80 and CD86. CD5 is negative on MEC1 cells (as on the vast majority of parental cells) and it has been lost by MEC2 cells after several months of culture. The cells have a complex karyotype. The tumour origin of MEC1 and MEC2 has been demonstrated by Southern blot analysis of the IgH loci and by Ig gene DNA sequencing. They use the VH4 Ig family and have not undergone somatic mutations (94.8% homology with germline Ig gene 4-59). Cytofluorographic analysis and RT-PCR reveal that MEC1 and MEC2 overexpress Bcl-2 together with Bax, express large amounts of Bcl-xL and trace amounts of Bcl-xS.

Amino Acid Sequence↗
PubMed1999

B-cell chronic lymphocytic leukemia: a bird of a different feather.

PURPOSE: To review the recent major advances in the molecular and cell biology of B-cell chronic lymphocytic leukemia (B-CLL). METHODS: We analyzed the nature of malignant B-CLL B cells and their interactions with the microenvironment. RESULTS: B-CLL is a malignancy of a mantle zone-based subpopulation of anergic, self-reactive, activated CD5+ B cells devoted to the production of polyreactive natural autoantibodies. It is the quintessential example of a human malignancy that primarily involves defects in the induction of programmed cell death. An abnormal karyotype is observed in about 50% of patients with B-CLL. Patients with 13q14 abnormalities show heavy somatic mutation and have a benign disease. Trisomy 12 is associated with unmutated VH genes, atypical cellular morphology, and progressive disease. Extended cell survival is further shielded by a kinetic refractoriness likely promoted by abnormalities of the B-cell antigen receptor complex and favored by some cytokines that highlight a reciprocal dialog between malignant B and T cells. Because the tumor cells act as the major accessory cells, the accumulating malignant B-cell population per se is a hurdle to the production of normal antibodies and leads to a progressive and severe hypogammaglobulinemia. Conceivably, in the presence of certain immunoglobulin genes and when the T-cell control becomes deficient, activated malignant B cells may become able to present self-antigens and drive residual normal B cells to produce polyclonal autoantibodies restricted to self-antigens expressed only by blood cells and cause autoimmune cytopenias. CONCLUSION: The distinctiveness of B-CLL B cells explains why B-CLL is different from other B-cell tumors and accounts for the development of immune deficiency and autoimmunity.

Autoimmunity↗
PubMed1999

Human myeloma cells express the CD38 ligand CD31.

Multiple myeloma (MM) plasma cells (PC) are CD38+. A ligand for CD38 is the adhesion molecule CD31. By flow cytometry and immunocytochemistry we have investigated whether malignant PC co-express CD38 and CD31. All 68 patients studied were CD38+. 14/14 monoclonal gammopathies of undetermined significance (MGUS) and 39/39 plasmacytic MM patients co-expressed CD38 and CD31 at high density. Only 1/11 plasmablastic MM and 1/4 plasma cell leukaemias (PCL) expressed CD31. These data indicated that PC malignancies co-expressed high levels of both CD38 and its ligand CD31, with the exception of plasmablastic MM and PCL.

5'-Nucleotidase↗
PubMed1998

The effectiveness and tolerability of epoetin alfa in patients with multiple myeloma refractory to chemotherapy.

Anemia is a frequent complication of multiple myeloma, becoming chronic in patients who are resistant to chemotherapy. This randomized, parallel, controlled multicenter study (71 patients receiving concomitant chemotherapy) evaluated the efficacy and safety of epoetin alfa in improving anemia and eliminating the need for transfusions in multiple myeloma patients refractory to conventional first- or second-line chemotherapy. Forty patients were treated with subcutaneous epoetin alfa (150 IU/kg per dose, increasing to 300 IU/kg per dose, every 3 weeks) for 6 months, and 31 entered a control group. The epoetin alfa group had a significantly (P < or = 0.001) greater percentage of patients (75% vs. 21%) with increases in hemoglobin levels and/or reduced transfusion requirements. In 44 non pre-transfused patients (20 controls, 24 in the epoetin alfa group), the mean increase in hemoglobin was significantly (P < or = 0.0001) greater in the epoetin alfa group (+2.1 vs. -0.2 g/dl). Increases in hematocrit and red blood cells were also significantly (P < or = 0.0001) greater in epoetin alfa-treated patients, with corresponding reductions in transfusion requirement. In the 27 pre-transfused patients (11 controls, 16 in the epoetin alfa group), there was a trend towards reduced transfusional need in epoetin alfa-treated patients. Thus, in patients with multiple myeloma refractory to chemotherapy epoetin alfa is a well-tolerated treatment which improves anemia in non pre-transfused patients and appears to reduce transfusion need in those previously transfused.

Aged↗