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Biomedical subjects

V Pistoia

Publications and source records attributed to V Pistoia.

At least 91 records · Page 5Linked to original sources
PubMed1991

Chronic childhood neutropenia: studies on the in vitro clonogenicity of bone marrow myeloid progenitors.

Bone marrow mononuclear cells (MNC) from 6 pediatric patients with chronic neutropenia were tested for myeloid colony formation upon stimulation with the supernatant of the 5637 cell line or with recombinant granulocyte-macrophage colony-stimulating factor or interleukin 3. Heterogeneous patterns of response of myeloid progenitors were observed in the individual patients, with no colony growth in 2 cases and abnormalities of colony formation or composition in two additional cases. Morphologic and surface marker analyses showed that the bone marrow of some patients contained an excess of lymphocytes with an altered subset distribution. In order to investigate whether or not there was a relationship between the latter abnormality and the observed clonogenic defects, marrow MNC were tested for myeloid colony formation before and after lymphocyte depletion. No evidence for a cell-mediated suppression of colony growth was obtained; likewise, patient sera failed to inhibit colony formation by normal bone marrow myeloid progenitors. Taken together, these data make it unlikely that, in our cases, immunologic mechanisms were responsible for the pathogenesis of chronic neutropenia.

Adolescent↗
PubMed1990

Immunoreactive lactoferrin in resting, activated, and neoplastic lymphocytes.

Lactoferrin (Lf) in lymphocytes was assessed with immunofluorescence/flow cytometric technique. Surface Lf was detected primarily among B-cell-enriched preparations. Tonsillar B-cells of different densities expressed surface Lf similarly. Very small percentages of CALLA+ ALL, HCL, or EBV-transformed B-cells expressed surface Lf, whereas B-CLL lymphocytes had the highest percentages of surface Lf positivity. Few resting, cultured, or neoplastic T-lymphocytes expressed Lf. The pattern of immunofluorescence and analyses of surface and total cellular immunoreactive Lf indicated that Lf is associated primarily with the lymphocyte surface. The percentage and/or intensity of surface Lf-specific fluorescence were not significantly altered in B- or T-cells by incubation with physiologic concentrations of differric Lf, and the percentages of Lf-positive cells detected in respective subjects remained stable over time. Surface Lf positivity was unrelated to the expression of other surface antigens (except those marking B- or T-cell lineage) or cell cycle. Expression and/or binding of Lf in B-lymphocytes may become increased during certain stages of cell maturation.

B-Lymphocytes↗
PubMed1990

Accelerated chemotherapy with or without GM-CSF for small cell lung cancer: a non-randomised pilot study.

Two series of five consecutive patients with small cell lung cancer were treated with an "accelerated" chemotherapy regimen of cyclophosphamide-doxorubicin-vincristine (CAV) and cisplatin-etoposide (PE) alternated possibly every week. In the first group of patients (median age 49 years, range 46-52) recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF) was given as soon as grade IV leukopenia occurred, while in the second group (median age 59 years, 55-68) no growth factor was administered. The mean interval between chemotherapy courses and the mean duration of chemotherapy were 10 and 57 days, respectively, in the patients supported with GM-CSF compared with 13 and 72 days in the control group. One GM-CSF treated patient was withdrawn after the third cycle because of severe toxicity. The mean white blood cell and platelet nadirs were 600 and 46,000/microliters in the first group vs. 840 and 105,000/microliters in the controls. Overall chemotherapy dose-intensity was increased by two fold in the patients given GM-CSF compared with a 1.5 fold increase in the control patients. In all cases, irrespective of their treatment, there was an impaired colony forming capacity of circulating and marrow haemopoietic progenitor cells when grade IV leukopenia occurred, with recovery after the end of leukopenia. This pilot study suggests that accelerated CAV/PE chemotherapy is feasible both with and without GM-CSF. Different GM-CSF schedules as well as combinations of different haemopoietic growth factors may further improve dose-intensity.

Aged↗
PubMed1990

Assessment of the potential malignancy of Epstein-Barr virus (EBV)-infected B cells in AIDS-related disorders.

Spontaneous lymphoblastoid cell lines (LCLs) were established from the peripheral blood of ten human immunodeficiency virus (HIV)-seropositive patients in order to investigate whether or not a progression of the cells toward a malignant state could be traced. The LCLs studied displayed no differences in their surface phenotype, karyotype, or tumorigenicity in nude mice when compared with a wide panel of control LCLs. However, four of the ten LCLs derived from HIV-seropositive patients formed colonies in agar with a cloning efficiency (0.1 to 0.9%) that was much lower than that of a control neoplastic B cell line (50%). Some sublines that were derived form the agar colonies expressed new activation markers (CD10 and Bac-1) but did not produce tumors in nude mice or display chromosomal abnormalities. These sublines might comprise cells that have progressed toward a more transformed state.

Animals↗
PubMed1989

Gamma heavy chain disease associated with Hodgkin's disease. Clinical, pathologic, and immunologic features of one case.

This report describes the clinical, pathologic, and immunologic features of a patient with gamma heavy chain disease (gamma-HCD) associated with Hodgkin's disease (HD). The diagnosis of gamma-HCD was established by serum electrophoresis and immunoelectrophoresis and confirmed by biochemical analysis of patient's serum showing the presence of an incomplete gamma chain, with an approximate molecular weight of 40 kilodaltons. The diagnosis of HD rested upon the presence of systemic lymphadenopathy, the typical histologic pattern and reactivity of Reed-Sternberg cells with the LeuM1-CD15 monoclonal antibody. The two diseases developed independently, in the absence of any immunosuppressive treatment. Furthermore, there was some evidence suggesting that HD tissue was not responsible for the production of the incomplete gamma chain. This and similar cases may provide a model for a better understanding of the events leading to the simultaneous outgrowth of two lymphoid neoplasias in the same patient.

Antibodies, Monoclonal↗
PubMed1989

CD8+CD11b+ peripheral blood T lymphocytes contain lymphokine-activated killer cell precursors.

CD3+CD8+ cells, purified from peripheral blood T cells by depletion of CD4+ lymphocytes, were tested for their cytotoxic activity against K-562 or HL-60 cells. Freshly prepared cells had no cytotoxic function, but upon exposure to recombinant interleukin 2 (rIL2) in vitro they acquired a lymphokine-activated killer (LAK) activity. Fractionation of CD3+CD8+ cells into CD11b+ and CD11b- cells demonstrated that all the cells with the potential of developing LAK cell functions were within the CD8+CD11b+ subset. These cells lacked natural killer cell markers such as CD16 or NKH1, but a proportion of them stained for Leu-7. Furthermore, they expressed the alpha/beta chains, but not the gamma/delta chains, of the T cell receptor, as could be determined by staining with the appropriate monoclonal antibodies. CD8+CD11b+ cells had a large granular lymphocyte morphology, as shown by both cytochemical and electron microscopy analyses. They proliferated in response to IL2 in vitro and developed cytotoxic functions against a number of natural killer resistant targets. Their response to phytohemagglutinin or pokeweed mitogen was very weak or absent. By contrast, CD8+CD11b- cells failed to generate LAK cells in response to rIL2, did not show a large granular lymphocyte morphology, but responded vigorously to phytohemagglutinin or pokeweed mitogen. Purified CD8+CD11b+ cells were cloned by limiting dilution in the presence of rIL2. The observed cloning efficiency of 19 +/- 0.3% indicates that a fraction of the cells only could respond to IL2. Furthermore, only 50% of the clones obtained had a LAK cell function. These data show that CD8+CD11b+ cells represent a heterogeneous cell population. Nevertheless this cell subset probably represents the major source of LAK cell progenitors within the circulating T cells.

Acid Phosphatase↗
PubMed1989

Studies on the oncogenic potential of Epstein-Barr-virus (EBV)-infected B cells in AIDS-related disorders.

Spontaneous lymphoblastoid cell lines (LCLs) were established from the peripheral blood of 10 human immunodeficiency virus (HIV)-seropositive patients in order to investigate whether or not progression of the cells towards a malignant state could be traced. The LCLs studied displayed no differences in their surface phenotype, karyotype, and tumorigenicity in nude mice as compared with a wide panel of control LCLs. Furthermore, no c-myc rearrangement could be detected in any of the LCLs. However, 4 of the 10 LCLs derived from HIV-seropositive patients formed colonies in agar with a cloning efficiency of 0.1-0.9%. This percentage was much lower than that of a control neoplastic B cell line (50%), but consistently higher than that observed for a battery of spontaneous LCLs. The cells of a number of sublines that were derived from the agar colonies expressed new activation markers (CD10 and Bac-1) but did not induce tumors in nude mice or display chromosomal abnormalities. These sublines might comprise cells that have progressed towards a more markedly transformed state.

Animals↗
PubMed1989

Isolation and characterization of Hofbauer cells from human placental villi.

Hofbauer cells are a major cell type of the human placental villous core and they are particularly numerous at the beginning of pregnancy. In the present study we describe a method suitable to obtain HC suspensions in a highly purified form. These suspensions have been analyzed for surface markers using a battery of monoclonal antibodies. Of all the surface markers used, Hofbauer cells were only positive for 4F2, LeuM2 and LeuM3 monoclonals which mainly detect cells of the monocyte-macrophage lineage. Hofbauer cells were consistently negative for HLA-DR antigens, C3bR and T- or B-cell markers. Hofbauer cells appeared capable of phagocytosing latex beads, adhering to and spreading over plastic surface and secreting lysozyme. In contrast, they failed to originate an efficient respiratory burst in response to appropriate stimulation. Hofbauer cells were positive for ANAE with a perinuclear localization of the enzyme activity, but consistently negative for peroxidase. These observations suggest that they share a number of features with cells of the monocyte-macrophage lineage and yet have some distinctive properties.

Chorionic Villi↗
PubMed1989

Production of colony-stimulating activity by human natural killer cells: analysis of the conditions that influence the release and detection of colony-stimulating activity.

Highly purified natural killer (NK) cell suspensions were tested for their capacity to release colony-stimulating activity (CSA) in vitro. NK cell suspensions comprised primarily CD16+ cells and were devoid of CD3+ T cells, CD15+ monocytes, and of B cells. CSA was detected in the NK cell supernatants and sustained the growth of myeloid colonies from both normal peripheral blood and bone marrow. CSA could be in part inhibited by pretreating NK cell culture supernatants with a specific goat anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) antiserum. The inhibition, however, was never complete, a finding that suggests that additional factors were responsible for CSA. Incubation of NK cells with K562 cells (an NK-sensitive target) or with normal bone marrow cells resulted in the appearance of a strong colony-inhibiting activity (CIA) in the culture supernatants. Such CIA was demonstrable in an experimental system where bone marrow or peripheral blood progenitors were induced to form myeloid colonies in the presence of conditioned medium by CSA-producing giant cell tumor (GCT) cells. Stimulation of NK cells with NK-insensitive targets failed to induce CIA production. Neutralizing antitumor necrosis factor (TNF) monoclonal antibodies (MoAbs) were found capable of inhibiting CIA present in the supernatants of NK cells stimulated with K562 cells. Following treatment with anti-TNF antibodies, CSA was again detectable in the same supernatants. This finding indicates that induction of TNF production did not concomitantly switch off CSA production by NK cells. Pretreatment of NK cells with recombinant interleukin-2 (rIL-2) or gamma interferon (r gamma IFN) did not change the amount of CSA released. However, treatment with rIL-2 caused the appearance of a factor in the NK cell supernatants capable of sustaining the formation of colonies of a larger size.

Antigens, Differentiation↗
PubMed1988

An in vitro model for Toxoplasma infection in man. Interaction between CD4+ monoclonal T cells and macrophages results in killing of trophozoites.

The cell interactions that take place between Toxoplasma gondii trophozoites and the human immune system have been investigated by using an in vitro model of infection. PBMC were co-cultured with live, appropriately attenuated, trophozoites. When cells from immune (seropositive) donors were used, a proliferative response was observed. At the same time, the proliferating T cells proved capable of controlling the growth of live trophozoites. By contrast, cells from seronegative donors failed to mount a proliferative response and intracellular overgrowth of trophozoites with subsequent cell injury occurred. Actively proliferating T cells were expanded in continuous cell lines with IL-2 and periodical restimulation with Ag in the presence of autologous irradiated mononuclear cells. From some of the lines obtained, clones were also derived. Ten clones were selected for further studies. They proliferated in response to trophozoites but not to unrelated Ag. Their response required the presence of autologous monocytes-macrophages isolated from peripheral blood on Percoll density gradients. B cells that were obtained from the same donors and immortalized by EBV infection proved inefficient as APC. These data suggest that live trophozoites have to be processed by macrophages in order to be presented to T cells. Upon appropriate antigen stimulation, all of the clones produced IL-2 and IFN-gamma, a finding that was consistent with both their CD4+ surface phenotype and their helper capacity on B cell proliferation and differentiation in vitro. The supernatants of all of the stimulated clones released a factor that activated macrophages to kill intracellular trophozoites as well as an unrelated pathogen, Listeria monocytogenes. This factor was identified as IFN-gamma because it was neutralized by specific anti-IFN-gamma antibodies. The present in vitro model of response to live protozoa may prove suitable to assess the role of both T lymphocytes and macrophages in intracellular parasite infections in man. Furthermore, this experimental system may be applied to detect specific lesions of cell mediated immunity in a number of immunodeficiency syndromes.

Adult↗
PubMed1988

Inhibition of phytohemagglutinin (PHA) induced human T-cell colonies by methylprednisolone.

The mechanisms underlying the inhibition of T-cell proliferation by methylprednisolone (MPS) have been investigated using a T-cell colony assay. Cell fractionation experiments have demonstrated that MPS exerted its effects at the level of both T-cells and monocytes. Thus, monocytes treated with MPS released a soluble factor that had suppressor activity on T-cell proliferation. Moreover, MPS directly blocked the proliferative capacity of T-cells, as demonstrated by the finding that MPS-treated T-cells formed reduced numbers of colonies even under optimal culture conditions and in the presence of exogenous IL-2.

Antigen-Presenting Cells↗
PubMed1988

Anti-lymphocyte globulin stimulates normal human T cells to proliferate and to release lymphokines in vitro. A study at the clonal level.

Human peripheral blood mononuclear cells (PBMC) were stimulated in vitro with anti-lymphocyte globulin (ALG), and the phenotypic and functional properties of the blasts obtained were investigated. When stained with monoclonal antibodies (MoAbs), all of the blasts were identified as T cells that expressed predominantly the CD4 phenotype (70% of the cells). The remaining blasts were CD8+. These findings demonstrate that ALG stimulates both helper-inducer and cytotoxic-suppressor cells at random since the CD4 to CD8 ratio in the stimulated blasts was the same as in resting PBMC. This ratio is different from that observed in short-term cultures of T cells stimulated with phytohemagglutinin (PHA) under the same conditions (CD4 to CD8 ratio less than 1). ALG-stimulated T cells were cloned by limiting dilution in the presence of recombinant Interleukin-2 (rIL-2). The clones obtained were expanded and maintained in long term cultures with rIL-2. Thirty-two clones were tested for their capacity of producing colony stimulating activity (CSA) or burst promoting activity (BPA). Twenty-eight of them produced CSA and 12 produced BPA. No correlation was found between the surface phenotype and the ability of the clones to produce CSA or BPA (ie, both the CD4+ and CD8+ clones released the cytokines). When 16 of the same clones were tested for II-2 and gamma interferon (gamma IFN) production, 12 were found to be gamma INF and IL-2 producers. All of the gamma IFN producers also released IL-2, whereas in the single clones no correlation was found with the capacity of releasing BPA and CSA. Supernatants from selected T-cell clones were also tested for hematopoietic growth factor activities in the presence of neutralizing antisera to human granulocyte-macrophage colony stimulating factor (GM-CSF) or to Interleukin-3 (IL-3). It was found that most CSA was attributable to GM-CSF, whereas BPA was mainly related to the presence of IL-3.

Animals↗
PubMed1987

Characterization of cells from invaded lymph nodes in patients with solid tumors. Lymphokine requirement for tumor-specific lymphoproliferative response.

The specific immune response against the malignant cells was investigated in patients with urinary bladder or larynx cancer. Lymphocytes from lymph nodes that drain the tumor site were tested for their proliferative and cytotoxic capacities against autologous malignant cells isolated from the primary tumor. In no occasion was a proliferative or a cytotoxic response observed. However, when the lymph node cell suspensions were depleted of cells expressing both OKM1 and Leu-7 markers by rosetting with the appropriate mAbs, a proliferative response could be observed. The lymphocytes responded to autologous tumor cells only if IL-2 was added to the cultures. IL-2 alone induced some cell proliferation, which was not, however, comparable to that observed in response to both IL-2 and tumor cells. A panel of allogeneic tumor cells consistently failed to stimulate OKM1-, Leu-7- cells in vitro. Response to autologous tumor cells was not caused by HLA-encoded molecules, as occurs in the autologous mixed lymphocyte reaction, since OKM1-, Leu-7- cells failed to be stimulated by autologous non-T cells. A proliferative response was observed only with cells from lymph nodes that had been classified as invaded by malignant cells according to histopathologic criteria. Cells from noninvaded lymph nodes consistently failed to respond. Cells stimulated with autologous tumor cells could be expanded in short-term lines by continuous addition of IL-2 and malignant cells. One of these lines, which comprised mainly T8+ cells, was stimulated to proliferate only by autologous tumor cells, and its proliferative response was inhibitable by anti-class I and not by anti-class II mAbs. This line showed lytic capacities against autologous malignant targets, while it was inefficient against all of the other allogeneic cells tested. In another set of experiments, the mechanisms whereby exogenous IL-2 had to be added to the cultures to sustain a proliferative response against neoplastic cells were investigated. When cocultured with autologous malignant cells, OKM1-, Leu-7- lymphocytes expressed IL-2 receptors, as could be assessed by anti-Tac fluorescent staining. Under these culture conditions, these cells did not produce IL-2, and no proliferation was observed. Addition of purified IL-1 to the cultures induced IL-2 production and cell proliferation. It is concluded that metastatic lymph nodes contain a T cell population that can be detected in a proliferative assay when both suppressor cells are removed and the appropriate molecular signals are supplied.

Antigens, Surface↗
PubMed1987

Ultrastructural analysis of human natural killer cell activation.

In this study we describe characteristic ultrastructural changes of CD3- large granular lymphocytes (LGL), ie, natural killer (NK) cells, following stimulation with recombinant (r) interleukin 2 (IL 2) or r-gamma interferon (r-gamma IFN) and after interaction with K562 target cells (TC) or Sepharose-bound anti-Fc gamma receptor (FcR) monoclonal antibody (MoAb). When compared to resting cells the cytolytic activity of r-IL 2- and r-gamma IFN-stimulated cells against K562 TC was enhanced. The r-IL 2-stimulated LGL were larger and consistently displayed the shape and cytoskeletal rearrangement characteristic of activated cells. The Golgi apparatus was expanded, and the number of electron-dense granules and vesicles was increased. The ultrastructural changes in r-gamma IFN-stimulated LGL were markedly different from those observed following r-IL 2 activation. Cells did not exhibit changes in size, shape, cytoskeletal organization, or in the structure of the Golgi apparatus. However, r-gamma IFN-stimulated cells exhibited distinctive changes in the structure and content of electron-dense granules with deaggregation of the matrix and parallel tubular arrays (PTAs). Within organelles apparently derived from the electron-dense granules, vesicular and tubular structures were noted that may be the morphological equivalent of cytotoxic factors produced by cytolytic effector cells. These ultrastructural observations indicate that r-IL 2 and r-gamma IFN enhance the lytic ability of NK cells by acting on distinct cell machineries. The cytolytic ability was decreased when LGL were pretreated with K562 TC or immobilized anti-FcR antibody. In both experimental conditions cells displayed ultrastructural features indicating activation as well as loss of cytoplasmic granules and other Golgi-derived organelles. Stimulation of r-gamma IFN- or r-IL 2-activated LGL with K562 TC or Sepharose-bound anti-FcR antibody decreased their cytolytic ability, with cells depleted of granules at the ultrastructural level. Intracytoplasmic fusion of granules and a massive release of the granule content were found in r-IL 2-stimulated cells, reminiscent of the mechanism of basophil degranulation. These observations suggest that multiple activation signals involving distinct surface membrane molecules induce release of cytolytic factors by both resting and activated NK cells.

Cell Line↗
PubMed1987

CD16+ NK lymphoproliferative disorders: cellular and molecular characterization.

We studied the mononuclear cells obtained from 2 patients with CD16+ lymphoproliferative disorders. In both subjects, over 80% of the circulating peripheral blood mononuclear cells were CD16+, CD2+, CD7+, CD3-, CD4-, and CD8-. In 1 patient, greater than 60% of the cells expressed HLA-DR and HLA-DQ gene products. Functional analysis of the natural killer (NK) cell activity of cells from this patient demonstrated 76% killing of K562 targets at ratios as low as 1:1 effector:targets. Karyotype analysis demonstrated a deletion on the long arm of chromosome 6, supporting the contention that the lymphocytosis in this patient was due to a clonally expanded population of cells. In additional studies, Southern blot analysis of DNA extracted from cells of this patient revealed that the beta-chain of the T cell receptor was of germ line configuration. This information supports the hypothesis that the clonally expanded NK population in this patient is of a lineage distinct from T cells and represents a true NK leukemia.

Aged↗