concanavalin-a and Leukemia--Monocytic--Acute

The induction of proteolytic enzymes is an important mechanism in the migration of monocytes into tissues and body fluids. The monocytic cell line THP-1 was used as a model system to study the production of a particular gelatinase. Upon stimulation with phorbol myristate acetate (PMA) the cells differentiated to the adherent phenotype and produced significant amounts of a 96-kD gelatinase in a dose-dependent way. The secretion rate was maximal between 12 and 24 h after induction. Study of gelatinase mRNA steady state levels showed that the synthesis of THP-1 gelatinase is regulated by PMA at transcriptional or posttranscriptional levels. Stimulation of signal transduction pathways with other substances, including calcium ionophore A 23187, dibutyryl cyclic AMP, and dexamethasone, were ineffective in inducing gelatinase mRNA or enzyme activity. However, THP-1 cells were responsive to the cytokine interleukin (IL)-1 beta, to bacterial lipopolysaccharide (LPS), and the lectin concanavalin A (Con A), the kinetics of gelatinase induction being similar to those of induction by PMA. The THP-1 cells did not synthesize and/or secrete detectable levels of IL-6 after stimulation with PMA, Con A, LPS, or IL-1 beta. The 96-kD monocytic THP-1 gelatinase was shown to be a neutral metalloproteinase that cross-reacted with hepatoma-derived and neutrophil gelatinases in immunoprecipitation experiments. The active enzyme produced by THP-1 cells consistently showed, however, a molecular mass different from that of normal granulocyte-, monocyte-, and tumor cell-derived gelatinases.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Amino Acid Sequence; Carcinoma, Hepatocellular; Cell Differentiation; Cell Line; Concanavalin A; Gelatinases; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Humans; Interleukin-1; Kinetics; Leukemia, Monocytic, Acute; Lipopolysaccharides; Liver Neoplasms; Molecular Sequence Data; Molecular Weight; Pepsin A; RNA, Messenger; Signal Transduction; Tetradecanoylphorbol Acetate; Transcription, Genetic

Normal and leukaemic lymphoid cells, both human and murine, were stained for specific carbohydrates with three fluorescein-labelled lectins: Aprotinin for sialyl (or uronyl) groups: Ricinus agglutinin for galactosyl groups; and Concanavalin A for mannosyl (or glucosyl) groups. The method gives permanent preparations of sections from methanol fixed, paraffin embedded tissues, from blood and bone marrow films or touch preparations of lymph nodes that were methanol fixed. Whereas normal lymphocytes and lymphoblasts reacted strongly for sialyl groups, lymphoblasts of acute lymphoblastic leukaemia and lymphocytes of chronic lymphocytic leukaemia gave a much weaker reaction. The same was the case of the lymphocytes of the Sézary variant and the lymphocytes of macroglobulinaemia. The fine processes of the cells of hairy cell leukaemia stained well for sialyl groups. No obvious differences were detected between normal monocytes and the cells of monocytic leukaemia, nor between normal plasma cells and those of myeloma.

Topics: Animals; Aprotinin; Carbohydrates; Concanavalin A; Fluoresceins; Humans; In Vitro Techniques; Lectins; Leukemia; Leukemia, Hairy Cell; Leukemia, Lymphoid; Leukemia, Monocytic, Acute; Lymphoid Tissue; Mice; Multiple Myeloma; Waldenstrom Macroglobulinemia

The kinetic of production of colony-stimulating activity (CSA) inducing mouse and human colony-forming cells (CFU-C) was tested in different human leukocyte culture systems. Stimulated and unstimulated cultures of spleen single cell suspensions, peripheral mononuclear leukocytes and acute monocytic leukemia (AMoL) cells were investigated. With the exception of the AMoL cells, stimulated cultures always revealed higher CSA levels than unstimulated controls. The spleen cell cultures exhibited the highest overall activity showing three molecular species of 70,000, 35,000 and 10,000 daltons activating human CFU-C to form colonies in the agar culture system. Furthermore it could be demonstrated that colony formation could be inhibited by low molecular weight fibrinogen degradation products obtained by digestion of fibrinogen with granulocyte-derived elastase.

Topics: Animals; Bone Marrow; Cells, Cultured; Colony-Forming Units Assay; Colony-Stimulating Factors; Concanavalin A; Fibrin Fibrinogen Degradation Products; Granulocytes; Hematopoietic Stem Cells; Humans; Leukemia, Monocytic, Acute; Lymphocytes; Macrophages; Mice; Monocytes; Spleen