concanavalin-a and Lymphoma--Large-B-Cell--Diffuse

Differentiation of U937 cells with phorbol myristate acetate (PMA) induces high stimulation by concanavalin A of the respiratory burst as well as an increase in concanavalin A-binding cell capacity. New concanavalin A-binding proteins are detected as differentiated U937 cells acquire their capacity to be activated by concanavalin A. We identified several concanavalin A-binding proteins, of molecular mass 30-200 kDa, in PMA-differentiated cells, but only some of them seem to be directly related to the concanavalin A effect on the respiratory burst. One of these candidates could be a glycoprotein with an apparent molecular mass of 140 kDa which behaved as a major concanavalin A-binding protein and is expressed on differentiated cells at the time these cells respond maximally to concanavalin A.

Topics: Calcimycin; Cell Differentiation; Cell Line; Concanavalin A; Humans; Kinetics; Lymphoma, Large B-Cell, Diffuse; N-Formylmethionine Leucyl-Phenylalanine; Receptors, Concanavalin A; Superoxides; Tetradecanoylphorbol Acetate; Tumor Cells, Cultured; Zymosan

Platelet factor 4 (PF4), a secreted platelet protein, alleviates concanavalin A-induced immunosuppression in mice. We now find that activity also resides in (i) the C-terminal tridecapeptide of PF4 (P13S), (ii) an analog of this in which arginine replaces the lysine residues and in which the last two amino acids are absent, (iii) the C-terminal 18 amino acids of low-affinity platelet factor 4, which is very similar to P13S, and (iv) peptide fragments of P13S that contain only 5-9 amino acids. P13S treated with fluorescamine to derivatize the free amino groups retained immunoregulatory activity but did not bind to heparin-agarose. The N-terminal and middle portions of PF4, polylysine, protamine, and three unrelated peptides were inactive in this assay.

Topics: Amino Acid Sequence; Animals; Concanavalin A; Immunosuppression Therapy; Lymphoma, Large B-Cell, Diffuse; Mice; Mice, Inbred BALB C; Molecular Sequence Data; Peptide Fragments; Platelet Factor 4; Polylysine; Protamines; Recombinant Proteins

The human monocyte/macrophage-like cell line U937 is a cholesterol auxotroph. Incubation of these cells in the growth medium in which delipidated fetal calf serum has been substituted for fetal calf serum depletes cellular cholesterol and inhibits growth. The cholesterol requirement of these cells for growth can be satisfied by human low-density lipoprotein (LDL), and very-low-density lipoprotein (VLDL), but not by high-density lipoprotein (HDL). U937 cells can bind and degrade LDL via a high-affinity site and this recognition is altered by acetylation of LDL. This indicates that these cells express relatively high LDL receptor activity and low levels of the acetyl-LDL receptor. The cells were used to study the role of cholesterol in lectin-mediated and fluid-phase endocytosis. Growth of the cells in the medium containing delipidated fetal calf serum results in impairment of both concanavalin A-mediated endocytosis of horseradish peroxidase and concanavalin A-independent endocytosis of Lucifer Yellow. Supplementation of the medium with cholesterol prevents cellular cholesterol depletion, supports growth and stimulates Lucifer Yellow endocytosis but fails to restore horseradish peroxidase endocytosis. However, if the cells are incubated in the presence of no less than 40 micrograms LDL protein/ml to maintain normal cell cholesterol levels, concanavalin A-mediated endocytosis of horseradish peroxidase is activated. The effect of LDL is specific since neither VLDL nor HDL3 at the same protein concentration activates horseradish peroxidase uptake by the cells. Furthermore, the activation of endocytosis by LDL is not inhibited by the inclusion of heparin or acetylation of the LDL indicating that binding of LDL to the LDL receptor is not required for these effects. The mediation of activation of horseradish peroxidase endocytosis by the lectin is presumed to involve binding of LDL to concanavalin A associated with the cell surface which in turn stimulates horseradish peroxidase binding and uptake by adsorptive endocytosis. The rate of fluid endocytosis and endosome formation seems to depend on cellular cholesterol content presumably because cholesterol is involved in maintaining the appropriate plasma membrane structure and fluidity.

Topics: Cell Division; Cell Line; Chloroquine; Cholesterol; Concanavalin A; Endocytosis; Heparin; Horseradish Peroxidase; Humans; Lipoproteins; Lipoproteins, LDL; Lymphoma, Large B-Cell, Diffuse; Macrophages; Monocytes

The established human histiocytic lymphoma cell line U-937 spontaneously produced a factor with biological activity similar to that ascribed to interleukin 1 (IL 1). Actually, supernatants from U-937 cells promoted proliferation of thymocytes initiated by concanavalin A (Con A) and replaced the requirement of accessory cells for activation of highly purified circulating T lymphocytes induced by Con A. Phorbol myristate acetate (PMA) significantly increased the titers of the helper factor produced by U-937 cells as compared to that secreted by non-PMA-treated U-937 cells or PMA-stimulated P388D1 murine macrophage tumor cells. Generally U-937 cells did not secrete detectable IL 1 activity during the first 24-48 h of culture. However, after this initial period the level of IL 1 activity increased and reached a maximum at 5-6 days of culture. Finally, the helper factor released by U-937 cells had an apparent mol. wt. of 12000-15000 as determined by Sephadex G-100 chromatography and lacked interleukin 2 activity as shown by its inability to support growth of IL 2-addicted T cell lines. To our knowledge this is the first report of an established human cell line capable of producing IL 1.

Topics: Animals; Cell Line; Concanavalin A; Humans; Interleukin-1; Lymphocyte Activation; Lymphoma, Large B-Cell, Diffuse; Mice; Mice, Inbred C57BL; T-Lymphocytes; Tetradecanoylphorbol Acetate

Pleural fluid from a patient with non-Hodgkin's lymphoma was examined for lymphocyte subpopulations and their proliferative response to PHA, Con A, and PWM. T lymphocytes were present in a high proportion; in contrast only few B lymphocytes were present when compared to peripheral blood T and B lymphocytes. Among T-cell subsets, Tmu cells were present in high numbers. By contrast Tgamma cells were lacking. Proliferative response to PHA and Con A were normal; however, PWM-induced proliferation was subnormal. This study demonstrates selective migration of a subset of T cells in pleural fluid.

Topics: Adolescent; Cell Migration Inhibition; Concanavalin A; Female; Humans; Lymphocyte Activation; Lymphoma, Large B-Cell, Diffuse; Phytohemagglutinins; Pleural Effusion; Pokeweed Mitogens; T-Lymphocytes

The data presented here indicate that the thymus plays an important role not only in the early ontogenic development of the immune system, but also in the maintenance of the immune potentials throughout the course of life. Moreover, thymic function is closely interrelated with functions of the other endocrine organs.

Topics: Aging; Animals; Concanavalin A; Endocrine Glands; Female; Immunity; Immunologic Surveillance; Lymphoma, Large B-Cell, Diffuse; Mice; Organ Size; Phytohemagglutinins; Spleen; Thymectomy

Peripheral blood lymphocytes and their in vitro reactivity have been recorded prior to treatment in 18 patients with Hodgkins disease, 11 with lymposarcoma, 13 with reticulosarcoma, 20 with various solid tumors and 37 normal control persons. The mean total numbers of lymphocytes, those of T lymphocytes,and the mean reactivity to PHA and ConA were reduced in all groups except lymphosarcoma, although with varying degrees of statistical significance. The percentages of T and B lymphocytes appeared to be normal in all groups, but the ranges of values were somewhat greater than among the normal controls. The mean total numbers of B lymphocytes were normal in all patient groups. All reductions seemed to be more pronounced in patients with disseminated than in those with localized disease, but none of these differences was statistically significant. All patient groups appeared to have reduced reactivity in MLC, while the ability to stimulate control lymphocytes was nearly normal. The results fail to indicate an in vitro immunological abberation specific to Hodgkin's disease. It seems that human malignant, neoplastic diseases are associated with a relatively selective reduction of the total numbers and reactivity of blood T lymphocytes. Various explanations of the reactivity impairment are proposed. The pathogenesis of the reduction of the total number of blood T lymphocytes remains obscure.

Topics: Adult; Aged; B-Lymphocytes; Concanavalin A; Female; Hodgkin Disease; Humans; Immune Adherence Reaction; Immunity, Cellular; Immunoglobulins; Lectins; Leukocyte Count; Lymphocyte Activation; Lymphocyte Culture Test, Mixed; Lymphoma; Lymphoma, Large B-Cell, Diffuse; Lymphoma, Non-Hodgkin; Male; Middle Aged; Mitogens; T-Lymphocytes

Topics: Agglutination Tests; B-Lymphocytes; Burkitt Lymphoma; Cell Membrane; Concanavalin A; Hodgkin Disease; Humans; Leukemia, Lymphoid; Lymph Nodes; Lymphocytes; Lymphoma; Lymphoma, Large B-Cell, Diffuse; Lymphoma, Non-Hodgkin; Receptors, Concanavalin A; Remission, Spontaneous; Spleen

Maintenance of remission solely by repeated BCG vaccinations in seven patients with non-Hodgkin's lymphoma who had achieved a complete clinical remission with initial standard therapy has provided sufficient encouragement to begin a randomized clinical trial. In vitro lymphocyte responses to mitogens and PPD used as parameters of cell-mediated immunity have not proved to be of value in predicting early or late recurrence in six pre-trial and trial patients. Eight out of twenty-one patients with malignant melanoma have shown a satisfactory clinical response (10-34 months) to immunotherapy. Those who respond must show immunological reactivity to the stimulating agent, however the best clinical responses were not associated with the highest degrees of in vivo and in vitro sensitization. The skin reactivity and the in vitro lymphocyte response to PPD as well as a 2-3-fold increase in the appearance of colony-forming units in the peripheral blood following the intratumour injection of BCG or PPD are helpful in prognosis and management of these patients. All patients with malignant melanoma who presented with a PHA response less than 40% of normal made a poor response to immunotherapy. Autopsies performed on seven patients dying with extensive melanocarcinomatous disease failed to show any serious adverse toxic reactions or infections from oral and intratumour injections of BCG.

Topics: Administration, Oral; Adult; BCG Vaccine; Concanavalin A; DNA; Female; Hematopoietic Stem Cells; Humans; Immunoglobulins; Immunotherapy; Injections, Intradermal; Lectins; Lymphocyte Activation; Lymphoma; Lymphoma, Large B-Cell, Diffuse; Lymphoma, Non-Hodgkin; Melanoma; Skin Neoplasms; Tuberculin; Vaccinia virus