Biomedical subjects

S Morrone

Publications and source records attributed to S Morrone.

48 records · Page 3Linked to original sources

PubMed1989

Granzyme A expression by normal rat natural killer (NK) cells in vivo and by interleukin 2-activated NK cells in vitro.

Granzyme A (TSP-1) is a serine esterase expressed in cytotoxic T and natural killer (NK) cell lines. Its presence in in vivo primed T cells is disputed at present. Here we show that normal rat NK cells contain granzyme A in vivo and that its expression is augmented by their short-term in vitro treatment with IL 2. Granzyme A expression in a NK cell population with LAK activity has also been examined.

Animals↗

PubMed1989

Laminin synthesis by NK cells and modulation of its expression by TPA (12-O-tetradecanoylphorbol-13-acetate).

Natural killer (NK) cells have been suggested to play a major role in resistance against metastatic spread of tumors. This study was aimed at understanding whether laminin (LM), a component of the extracellular matrix involved in the mechanism of tumor invasion and cell interaction, is expressed by NK cells. The results indicate that NK cells can synthesize and display on the cell surface LM and that TPA can modulate its expression. Our findings suggest that the presence of LM on NK cells could be relevant in the control of tumor invasion by NK cells.

Animals↗

PubMed1989

Polyclonal B lymphocyte activation in progressive systemic sclerosis.

In 13 women affected by progressive systemic sclerosis (PSS) the activation state of circulating B lymphocytes by use of monoclonal antibodies and the in vitro IgG, IgA, IgM synthesis by peripheral blood mononuclear cells (PBMC) cultured with or without pokeweed-mitogen (PWM) were evaluated. The total and "activated" B lymphocytes were increased. The supernatants of PBMC cultured without PWM contained increased IgG and IgA levels; only in two patients, however, were IgM levels increased. The addition of PWM augmented IgG and IgA levels only in three cases and never IgM levels. Our results indicate that the polyclonal hyperactivity of B lymphocytes is a major immunologic feature in PSS patients. The lack of increase of in vitro immunoglobulin synthesis in the presence of PWM suggests either that B lymphocytes, already maximally activated in vivo, are unresponsive to further mitogen stimulation or that a more complex imbalance of B lymphocyte responsiveness to PWM may exist.

Adult↗

PubMed1988

Proliferative effects of 12-O-tetradecanoylphorbol-13-acetate (TPA) and calcium ionophores on human large granular lymphocytes (LGL).

The proliferative responses of natural killer (NK) cells to 12-O-tetradecanoylphorbol-13-acetate (TPA), which directly activates protein kinase c(PKC), and to the Ca2+ ionophores A23817 and ionomycin, known to enhance the intracellular calcium, have been investigated. Highly purified large granular lymphocytes (LGL) were cultured for 12-30 hr in the presence of TPA, ionomycin, or A23817. TPA alone (1-20 ng/ml) triggered rapid LGL proliferation, whereas the calcium ionophores were ineffective. The addition of either calcium ionophore to suboptimal doses or TPA (0.1-0.5 ng/ml) resulted in a synergistic effect on LGL proliferation. Under these conditions high levels of IL-2 activity were released by the LGL. Phenotypic analysis revealed the rapid loss of the Fc gamma receptors (CD16) on LGL and the induction of the expression of IL-2 (CD25) and transferrin receptors and of HLA-DR, but not of CD3. Removal of extracellular Ca2+ by addition of EGTA at the beginning of the culture greatly depressed LGL proliferation and IL-2 production, and blocked phenotypic changes, such as the expression of Tac antigen. Finally, progression to the proliferative phase of LGL, activated by TPA alone or with ionomycin, was completely abrogated by a hyperimmune anti-IL-2 antiserum.

Antigens, Surface↗

PubMed1987

HTLV-V: a new human retrovirus isolated in a Tac-negative T cell lymphoma/leukemia.

A new human retrovirus was isolated from a continuous cell line derived from a patient with CD4+ Tac- cutaneous T cell lymphoma/leukemia. This virus is related to but distinct from human T cell leukemia/lymphoma virus types I and II (HTLV-I and HTLV-II) and human immunodeficiency virus (HIV-1). With the use of a fragment of provirus cloned from one patient with T cell leukemia, closely related sequences were found in DNA of the cell line and of tumor cells from seven other patients with the same disease; these sequences were only distantly related to HTLV-I. The phenotype of the cells and the clinical course of the disease were clearly distinguishable from leukemia associated with HTLV-I. All patients and the wife of one patient showed a weak serological cross-reactivity with both HTLV-I and HIV-1 antigens. None of the patients proved to be at any apparent risk for HIV-1 infection. The name proposed for this virus is HTLV-V, and the date indicate that it may be a primary etiological factor in the major group of cutaneous T cell lymphomas/leukemias, including the sporadic lymphomas known as mycoses fungoides.

Antigens, Viral↗

PubMed1987

High frequency production of hybridomas secreting antibodies to cell antigens.

The efficiency of various immunization protocols for the production of hybridomas secreting immunoglobulins specific to cell antigens was evaluated in 15 different fusion experiments. Some of these experiments were performed with splenic B-lymphocytes from mice at different stages of immunization. This approach allowed a dynamic analysis of immunocompetent splenic B-lymphocyte production during the immunization cycle.

Animals↗

PubMed1981

Biliary excretion of glycolipid in induced or inherited glucosylceramide lipidosis.

Metabolically inert L-[1-14C]glucosylceramide is stored predominantly in the liver after intravenous administration to mice. The half-time of this glycolipid analogue in the liver is 3.5 days and its clearance occurs predominantly via the bile. Within the limited number of Gaucher specimens available for examination very high levels of glucosylceramide were found in the bile of one patient and in the liver of two patients with biliary obstruction. The question of a possible relationship between biliary excretion of glycolipid and the pathogenesis of Gaucher's disease will require further studies.

Animals↗

PubMed1981

Studies in vivo of the tissue uptake, cellular distribution and catabolic turnover of exogenous glucocerebrosidase in rat.

The kinetics of plasma clearance of highly purified human placental glucocerebrosidase in rats were biphasic with 75% of the infused dose showing a rapid clearance (t1/2 = 11 min) and the remaining 25% a considerably lower rate (t1/2 = 60 min). The majority of the enzyme (60%) was taken up by the liver. Although saturation kinetics for the clearance or uptake were not observed, the very high hepatic endocytic index (217 microliter/min) of glucocerebrosidase uptake indicated that liver uptake was mediated by an adsorptive endocytic process. Analysis of the cellular distribution of recovered glucocerebrosidase revealed predominantly parenchymal cell uptake with 38% of the exogenous enzyme in hepatocytes and only 2% in sinusoidal cells. High-mannose glycoproteins blocked hepatocyte and sinusoidal cell uptake of glucocerebrosidase equally. Kinetic experiments failed to demonstrate a transfer or shuttle of exogenous glucocerebrosidase from sinusoidal cells to hepatocytes. The possibility was raised that uptake of enzyme by the liver may be mediated by a common receptor that functions in both hepatocytes and sinusoidal cells. The catabolic turnover of exogenous glucocerebrosidase in rat liver was biphasic and the rate of decline was similar in hepatocytes and sinusoidal cells.

Animals↗

PubMed1979

Effect of deglycosylation on the binding and immunoreactivity of human thyroxine-binding globulin.

Thyroxine-binding globulin (TBG), prepared from human serum by an improved purification method, was treated with a mixture of neuraminidase, beta-galactosidase, alpha-mannosidase, and beta-N-aectylglucosaminidase, which resulted in the removal of approximately 86% of saccharides. Purification by thyroxine-Sepharose affinity chromatography gave a homogeneous protein as shown by equilibrium sedimentation and sodium dodecylsulfate-polyacrylamide gel electrophoresis. Amino acid and NH2-terminal sequence analysis indicated that the protein moiety was intact. Deglycosylation had no effect on the stoichiometry of the binding of L-thyroxine as shown by tryptophanyl fluorescence quenching and equilibrium dialysis at pH 8.6 and 25 degrees C. However, the affinity constant for L-thyroxine was reduced from 1.6 X 10(9) M-1 to 0.58 X 10(9) M-1. Analysis of radioimmunoassay data revealed that deglycosylation resulted in a slight decrease of the affinity constant for anti-TBG antibody from 3.9 X 10(10) M-1 to 1.8 X 10(10) M-1. These results suggest that the polypeptide moiety, rather than the heterosaccharides, contains the antigenic determinants. Removal of the majority of the heterosaccharides of TBG has only a minor effect on its immunoreactivity and on the binding of thyroid hormone.

Amino Acids↗

PubMedDate not supplied

In vivo cadmium treatment alters natural killer activity and large granular lymphocyte number in the rat.

The effects of oral exposure for nearly 6 months to Cd (200 or 400 ppm) on rat natural killer (NK) activity were investigated. No significant differences in body and thymus weights were observed. Peripheral blood lymphocyte (PBL) number was consistently higher in treated rats throughout the treatment; the number of spleen cells decreased during the first 50 days, and then reached a level higher than in controls. NK activity, evaluated in a 4-h chromium release assay against YAC-1 target cells, was altered in treated rats: lower up to day 30, and then higher. In parallel, a reduction of the large granular lymphocytes (LGL) was found initially in the peripheral blood of Cd-treated rats, followed by a persistent marked increase. These changes were closely correlated with the altered distribution of CD8+ aGM1+ CD5- cells, which mostly consist of NK cells. Fluorescence-activated cell sorter (FACS) analysis revealed a decrease of cell subset with a typical NK phenotype during the first 30 days of treatment and a clear increase thereafter. Post-exposure observations indicated that all these effects disappeared with a return to control values 2 months after cessation of treatment. These findings suggest that in vivo administration of Cd induces both inhibitory and stimulatory effects on rat NK cell number and cytotoxic activity, depending on time of exposure.

Animals↗

PubMedDate not supplied

Effects of triptorelin, a gonadotropin-releasing hormone agonist, on the human prostatic cell lines PC3 and LNCaP.

Some analogues of gonadotropin-releasing hormone (GnRH) influence the in vitro proliferation of cultured human cells by complex interactions that are only partially understood. This study explored the effect of Triptorelin, a GnRH agonist, on the LNCaP and PC3 prostatic cell lines, which are, respectively, responsive and unresponsive to androgen stimulation. The toxicity and cell cycle modifications induced by the drug were investigated by FACScan analysis; the effect on cell proliferation in different culture conditions was determined by counting in a Burker chamber; and the expression of binding sites for 125I-Triptorelin was revealed by displacement experiments. PC3 cell growth was completely unaffected by Triptorelin. The drug caused a double stimulatory-inhibitory action on the growth of actively proliferating LNCaP cells, depending upon the dose and environment. A significant inhibitory effect on proliferation, ranging from 25% to 65% compared with controls, was observed at a high dose (10(-4) M) according to the culture conditions; and a proliferative effect (42% compared with controls) was observed at a lower dose (10(-7) M) only in fetal bovine serum-supplemented medium. Displacement experiments revealed the expression of moderately high affinity and low affinity binding sites in LNCaP cells (Kd = 2.6 x 10(-8) and 7.7 x 10(-6) M) but only low affinity binding sites in PC3 cells (Kd = 2.7 x 10(-6) M), which suggests that the expression of binding sites with different affinity could be associated with a biological response to the drug. Proliferation studies in the presence of Cetrorelix, a GnRH antagonist, confirmed the different sensitivity of the 2 cell lines to GnRH analogues and showed that the proliferative effect of Triptorelin on LNCaP cells can be inhibited by the antagonist. Data confirm the cell specificity of Triptorelin's action and the peculiarity of its effects on prostatic cell proliferation in our experimental conditions.

Cell Cycle↗

PubMedDate not supplied

Immunological usefulness of semen manipulation for artificial insemination homologous (AIH) in subjects with antisperm antibodies bound to sperm surface.

The authors report trials carried out in the preparation of semen for homologous artificial insemination in subjects with antisperm autoantibodies. The tests have demonstrated that swim-up is not able to select spermatozoa free of antibodies bound to the sperm surface. All the experiments of migration, dilution, antigenic competition and cryoconservation, carried out to evaluate the theoretical possibility of a better recovery of non "immunologically compromised" spermatozoa, have confirmed such negative results both with the Immunobead Test and Cytofluorimetric analysis.

Autoantibodies↗