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Biomedical subjects

V Pistoia

Publications and source records attributed to V Pistoia.

At least 109 records · Page 6Linked to original sources
PubMed1987

Production of colony-stimulating activity by normal and neoplastic human B lymphocytes.

Normal human B cells were purified from peripheral blood or tonsils and tested for their ability to release colony-stimulating activity (CSA) in short-term cultures. The target cells used in the CSA assays were from peripheral blood or bone marrow. Unstimulated B cells produced CSA in amounts similar to those present in the GCT-conditioned medium used as a positive control. The B cell-derived CSA predominantly promoted the growth of colonies that contained macrophages alone or macrophages and granulocytes. CSA eluted in a single peak from a G-75 Sephadex column with an approximate molecular weight (mw) of 65 to 70 kilodaltons (kd). Fractionation of tonsil B lymphocytes on Percoll density gradients showed that large B cells, probably already activated in vivo, were the main source of CSA. By contrast, small, resting B cells recovered from a different fraction of the Percoll gradient released minimum amounts or no CSA. However, these B cells became CSA producers following stimulation with Staphylococcus aureus Cowan (SAC) in vitro. B cells purified from the peripheral blood of nine out of 12 patients with B-cell chronic lymphocytic leukemia (B-CLL) also released CSA in vitro in the absence of stimuli. These findings suggest that by releasing CSA, B cells may have a role in the regulation of hematopoiesis and in the control of the inflammatory process.

Antigens, Surface↗
PubMed1987

Spontaneous growth of colonies with mature T lineage phenotype from T-cell-depleted bone marrow precursors in a patient with a lymphoproliferative disorder of the large granular lymphocytes.

Bone marrow cells from a patient with pancytopenia and a lymphoproliferative disorder of large granular lymphocytes (LGL) were cultured and tested for their hemopoietic colony-forming potential. Neither erythroid nor granulocyte-macrophage colony formation could be obtained from unfractionated, or LGL-depleted bone marrow cell preparations. However, a spontaneous growth of lymphoid colonies was observed after culturing LGL-depleted (T3-) bone marrow cell suspensions for 25 days. Pooled colonies expanded with recombinant interleukin-2 yielded a population composed predominantly of mature T cells (T3+, Leu 6-). These findings suggest that some (T3-) T cell precursors may mature in the bone marrow and that, in our patient, LGL may have exerted a suppressor effect on this maturational process.

Aged↗
PubMed1986

In vitro production of interleukin 1 by normal and malignant human B lymphocytes.

In this study, the capacity of normal and neoplastic B lymphocytes to release interleukin 1 (IL 1) has been investigated. Peripheral blood B cells from normal donors were isolated by depletion of E rosetting cells and by positive selection of cells expressing surface immunoglobulin (sIg) or the B1 marker. Peripheral blood B cells from patients with B cell chronic lymphocytic leukemia (B-CLL) were purified by removal of E rosetting cells followed by complement-mediated cytotoxicity with selected monoclonal antibodies. All of the normal B cell suspensions and the large majority of the B-CLL cells produced in culture high amounts of IL 1 in the absence of any apparent stimulus. Control experiments ruled out that small numbers of monocytes in the B cell suspensions could represent the source of IL 1. These data support the contention that B cells participate to the immune response as accessory cells for T cell activation not only by physically presenting antigen, but also by releasing IL 1.

Animals↗
PubMed1986

Establishment of Tac-negative, interleukin-2-dependent cytotoxic cell lines from large granular lymphocytes (LGL) of patients with expanded LGL populations.

Cell lines were established from purified large granular lymphocytes (LGL) isolated from the peripheral blood of seven patients with phenotypically homogeneous LGL expansions. LGL were stimulated with phytohemagglutinin (PHA) or recombinant interleukin-2 (rIL-2) and further expanded in vitro in IL-2-containing media. The surface phenotype of LGL, as assessed by monoclonal antibody staining, was T3+ T8+ in five patients, T3- T8- in one, and T3+ T8- in another patient. The cells also expressed Leu 7, Leu 11, and/or OKM 1 markers in various proportions and were identifiable as LGL by their morphological and cytochemical features. The original surface phenotype of the unstimulated LGL was retained in the IL-2-dependent cell lines from each individual patient, i.e., T3+ T8+ cells originated T3+ T8+ cell lines and T3- T8- cells originated T3- T8- cell lines. Other markers, such as Leu 11 and OKM 1, were generally lost in culture. LGL proliferated in response to rIL-2 but did not express detectable IL-2 receptors, even after prolonged periods of culture. All cell lines from each individual patient had the same surface phenotype, and within the single lines, all of the cells expressed the same markers. Cell lines from two patients consistently displayed chromosomal abnormalities. Although different in the two patients, the abnormalities were identical in all of the lines from the same patient and detectable in most of the cells examined, suggesting a clonal origin for the abnormally expanded LGL populations. Freshly isolated LGL did not exert NK activity. However, the IL-2-dependent LGL lines acquired the ability to kill K562 target cells and to produce gamma interferon (gamma-IFN). No direct correlation was observed between these two properties.

Antigens, Surface↗
PubMed1986

Presence of activated T-cells with a T8+ M1+ Leu 7+ surface phenotype in invaded lymph nodes from patients with solid tumors.

The lymphocyte surface phenotype of lymph nodes from patients with larynx or urinary bladder carcinoma was investigated by using a panel of monoclonal antibodies. The phenotype pattern of lymphocytes from lymph nodes invaded by malignant cells (as assessed by histopathology) was different from that of the cells from noninvaded or normal control nodes. Although the proportion of natural killer cells or macrophages was similar in the 3 groups of lymph nodes, invaded lymph nodes contained a higher proportion of T-cells and a lower B-cell percentage. Furthermore, cells from invaded nodes comprised 15-20% of T3+ T8+ cells that coexpressed the M1 marker and, to some extent, also the Leu 7 marker. A large proportion of cells with multiple markers were activated, as shown by the expression of Tac and HLA-DR antigens. In 2 patients activated T8+ cells expressing also M1 and Leu 7 markers infiltrated the tumor site. The presence of these activated cells both in involved nodes and tumor mass may indicate that they originate in response to cancer.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1986

Large granular lymphocytes from patients with expanded LGL populations acquire cytotoxic functions and release lymphokines upon in vitro activation.

The phenotypic and functional features of purified large granular lymphocytes (LGL) from ten patients with LGL population expansions and cytopenias are described. The predominant LGL phenotypes were T3+, T8+, Leu-11+/-; however, in two patients, LGL expressed a T3-, Leu-11+ phenotype. Variable combinations of other LGL markers (OKM1, Leu-7), and HLA-DR were detected in individual cases. In nine of ten cases, freshly isolated LGL did not exert cytolytic activity for K562 target cells, but purified LGL cultured in the presence of recombinant interleukin 2 (rIL2) acquired potent cytotoxic activity in all cases tested. LGL did not proliferate in response to phytohemagglutinin (PHA). However, LGL released variable amounts of IL2 and gamma-interferon (gamma-IFN) after PHA stimulation. In some cases, stimulation of fresh LGL with recombinant IL2 induced production of gamma-IFN. No correlation was found between the functional capabilities and the original phenotype of the expanded LGL populations.

Antibodies, Monoclonal↗
PubMed1985

Restoration of defective EAG-rosetting capacity of cancer patient neutrophils by levamisole.

Levamisole, used in vitro at therapeutic concentrations, was found able to restore the defective Fc-receptor activity of cancer patient neutrophils. In addition, the drug prevented the inhibition of normal neutrophils Fc-receptor function by cancer patient sera. The neutrophil Fc-receptor function was also restored in six of seven cancer patients after in vivo administration of levamisole (2.5 mg/Kg/day for 3 days). Due to the central role played by the Fc-receptor function in host defence mechanisms, including phagocytosis as well as antibody dependent cellular cytotoxicity, the capacity of levamisole to restore defective neutrophil Fc-receptor function in cancer patients could contribute to the "immunomodulating" effect of the drug.

Cell Membrane↗
PubMed1985

Meeting report on recent advances on T-lymphocytes in normal and leukemia patients.

We report on the main topics discussed at the "Human T-Lymphocytes in Normal and Leukemia Patients" meeting, including the "Second International Workshop on T-Cell Colonies" (Reggio Calabria, September 16-19, 1984). Improved knowledge in the field of T-lymphocyte biology has contributed greatly to a better clinical definition of T-cell-derived lymphoproliferative disorders. The T-cell colony assay seems to represent a useful tool for studying the early steps of T-lymphocyte maturation and for characterizing accessory cells and soluble mediators that regulate T-cell proliferation.

B-Lymphocytes↗
PubMed1985

Impaired in vitro growth of PHA induced T lymphocyte colonies in hemodialyzed renal failure patients.

Using an in vitro method that allows the study of the colony forming capacity of phytohemagglutinin stimulated peripheral blood T lymphocytes, we have detected an impaired T cell colony formation in hemodialyzed renal failure patients. By contrast a near normal pattern of responses was observed in patients treated with a conservative therapy. The poor in vitro T cell responsiveness of hemodialyzed patients was not corrected by supplementing the cultures with an adherent cell contitioned medium prepared from normal donors. We conclude that an intrinsic defect of the T cell colony forming capacity exists in hemodialyzed patients.

Adult↗
PubMed1985

Large granular lymphocytes have a promoting activity on human peripheral blood erythroid burst-forming units.

Peripheral blood mononuclear cells were fractionated according to the expression of a variety of surface markers, and the fractions obtained were tested for erythroid burst-forming unit (BFU-E) colony formation. BFU-Es were detected in the HLA-DR+ non-T cell fraction, but gave rise to optimum colony numbers only in the presence of a nonadherent, relatively radioresistant cell. This accessory cell was found among the HLA-DR- non-T, non-B cells, a fraction that was particularly enriched in large granular lymphocytes (LGLs). Experiments carried out to assess directly the surface markers of the accessory cell revealed an FcR+, OKM1+, Leu 7+, Leu 11+, OKT4-, OKT8- surface phenotype, which is consistent with that of the majority of LGLs. Peripheral blood LGLs, purified by Percoll density gradient, proved very efficient in promoting optimal BFU-E colony formation. All of these results indicate that LGLs have a potent erythroid burst-promoting activity. Such activity is probably mediated through the release of soluble factors, as shown by the observation that LGL culture supernatants were as effective as LGLs in sustaining colony formation.

Antigens, Surface↗
PubMed1985

Production of B cell growth factor by a Leu-7+, OKM1+ non-T cell with the features of large granular lymphocytes (LGL).

The present study reports the characterization of a non-T cell from human peripheral blood which is capable of releasing BCGF. This BCGF-producing non-T cell had a T3-, T8-, Leu-7+, OKM1+, HLA-DR-, Leu-11- surface phenotype and was likely to belong to the so-called large granular lymphocyte (LGL) subset because: after fractionation of non-T cells according to the expression of Leu-7 or HLA-DR markers, it was found in the Leu-7+, HLA-DR- fractions that were particularly enriched in LGL; it co-purified with LGL on Percoll density gradients; and it expressed Leu-7 and OKM1 markers that are shared by a large fraction of LGL. Although co-purified with cells with potent NK capacities, the BCGF-producing cell was not cytotoxic, because treatment of Leu-7+ cells with Leu-11 monoclonal antibody and complement abolished the NK activity but left the BCGF activity unaltered. The factor released by this LGL subset was not IL 1 or IL 2 mistakenly interpreted as BCGF, because: a) cell supernatants particularly rich in BCGF activity contained very little or no IL 1 or IL 2; b) BCGF-induced B cell proliferation was not inhibitable by anti-Tac antibodies (this in spite of the expression of IL 2 receptor by a proportion of activated B cells); and c) BCGF activity was absorbed by B but not T blasts.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1984

Human placental Hofbauer cells promote mitogen induced T cell proliferation.

Hofbauer cells are a major cell type of the human placental villous core particularly numerous at the beginning of pregnancy. In the present study we have investigated whether or not Hofbauer cells could subserve the function of accessory cells for colony formation by phytohemagglutinin stimulated allogeneic T cells. Results showed that Hofbauer cells are capable to play an accessory role on T cell proliferation probably due to the release of interleukin 1-like soluble factors.

Colony-Forming Units Assay↗
PubMed1983

Suppression of PHA-induced human T-lymphocyte colony formation following in vivo administration of anti-lymphocyte globulin. Report of one case.

The administration of anti-lymphocyte globulin in a patient with pure red cell aplasia completely abrogated the PHA-induced T colony forming capacity of peripheral blood mononuclear cells. The possible mechanisms of the ALG-induced suppression are discussed. It is proposed that T-colony assays may represent an useful tool for monitoring some effects of immunosuppressive drugs on T cells.

Anemia, Aplastic↗
PubMed1983

PHA-induced human T cell colony formation: enhancing effect of large granular lymphocytes.

The capacity of phytohemagglutinin (PHA)-stimulated human T cells to develop into colonies in agar has been evaluated in the presence or absence of a variety of peripheral blood mononuclear cell subsets. A subpopulation of non-T, non-B cells with receptors for the Fc portion of IgG (i.e. third population cells or TPC) was found to enhance considerably the T cell colony forming capacity. Since TPC have been previously shown to be highly enriched for large granular lymphocytes (LGL, i.e. cells with cytoplasmic azurophilic granules and acid hydrolases), LGL were purified on Percoll density gradients and tested for their T cell colony enhancing capacity. It was shown that LGL were indeed the cells capable of enhancing the T cell colony formation.

Cell Separation↗
PubMed1982

Acid hydrolases as markers of maturation in B-cell chronic lymphocytic leukemia.

Malignant lymphocytes from 30 B-cell chronic lymphocytic leukemia (B-CLL) patients were studied for the cytochemical localization of two acid hydrolases, alpha-naphthyl acetate esterase (ANAE) and acid phosphatase (AT). The large majority of the cells stained for both ANAE and AP in 7 cases, for AP only in 18 cases, and were negative for both the enzymes in 5 cases. Ultrastructural analysis revealed that the cells that displayed more mature morphological features, such as well developed smooth and rough membrane compartments, were those positive for acid hydrolases. That ANAE and AP are expressed by B cells at late stage of maturation was confirmed by the finding that some lymphocytes and all of the plasmacytoid lymphocytes and plasma cells from Walderström's macroglobulinemia, from mixed cryoglobulinemia, and from multiple myeloma patients stained strongly for both ANAE and AP. Using the expression of acid hydrolases and certain ultrastructural features as markers of cell differentiation, it was possible to demonstrate a process of maturation within the single B-CLL clones with accumulation of the cells at stages that differed in the various cases.

Acid Phosphatase↗
PubMed1982

Phytohemagglutinin or pokeweed mitogen induction of in vitro colony formation by T-cells from patients with chronic lymphocytic leukemia.

The colony-forming capacity of peripheral blood T-cells isolated from B-cell chronic lymphocytic leukemia patients was studied and compared with that of peripheral blood T-cells isolated from 2 groups of normal controls (young and aged healthy donors). Upon stimulation with phytohemagglutinin or pokeweed mitogen. T-cells from both the patients and the controls developed into colonies but only in the presence of the appropriate conditioned media. When the responses of the 3 groups were compared, no statistically significant differences were detected. However, the number of patients who failed to respond to phytohemagglutinin was larger than that of normal controls. Studies on a selected group of patients demonstrated that such unresponsiveness was unrelated to the presence of suppressor cells or to inadequate conditions used for stimulation in culture. Rather, this unresponsiveness may be connected with an intrinsic T-cell defect present in certain B-cell chronic lymphocytic leukemia patients.

Adult↗
PubMed1982

Enhancement of the in vitro colony-forming capacity of human T lymphocytes induced by levamisole.

The colony-forming capacity of normal peripheral blood mononuclear cells and of TG-depleted cell suspensions induced by PHA was investigated in the presence of different concentrations of levamisole. The results obtained demonstrate that: (1) the drug enhances significantly the number of colonies formed by both mononuclear cells and TG-depleted cells at concentrations ranging from 5 x 10(-6) to 5 x 10(-8 M; (2) this stimulatory activity results from a direct effect on T cells; and (3) adherent accessory cells are unaffected by the in vitro treatment with levamisole.

Cell Adhesion↗