concanavalin-a and Cystic-Fibrosis

In order to test whether abnormalities of glycosylation occur in cystic fibrosis (CF), the glycan microheterogeneity of alpha 1-antitrypsin (alpha 1-AT) was studied in serum and meconium from normal individuals and patients with cystic fibrosis, by crossed immunoaffinoelectrophoresis (CIAE) using free Concanavalin A (Con A), Lens culinaris lectin (LCA) and wheat germ agglutinin (WGA). Three main results emerged from this study: (1) modification of glycosylation in serum alpha 1-AT from patients with cystic fibrosis were only significant with free Con A and WGA; this probably results from a reduced synthesis of the bi-antennary side-chains or by their increased catabolism. (2) Differences in isoforms found in alpha 1-AT from normal individuals and patients with CF using free Con A, LCA, were more pronounced in the meconium than in the serum; this may provide a useful test in diagnosis of cystic fibrosis. (3) There was parallelism between the behaviour of alpha 1-AT in serum and meconium from patients with CF using LCA, Con A; this may be explained by different types or levels of disfunction affecting a glycosylation mechanism.

Topics: Adult; alpha 1-Antitrypsin; Concanavalin A; Cystic Fibrosis; Glycosylation; Humans; Immunoelectrophoresis, Two-Dimensional; Infant, Newborn; Lectins; Meconium; Plant Lectins; Polysaccharides; Wheat Germ Agglutinins

Freshly isolated monocytes from cystic fibrosis (CF) heterozygotes and homozygotes had significantly increased oxygen uptake and superoxide formation after surface glycoprotein stimulation than did monocytes from age- and sex-matched controls. Lack of differences among the genotypes in inhibition by simple sugars of the concanavalin A-stimulated superoxide production and lack of differences in concanavalin A-binding surface proteins suggested that different regulation of the oxidase pathway produced the increased oxygen uptake and superoxide formation in CF patients and carriers. This regulatory role is consistent with the predicted structure of the CF gene product. The results support the hypothesis that the mononuclear phagocytes of CF heterozygotes have a significantly increased ability to kill intracellular microbes and may confer a selective advantage to the host.

Topics: Adolescent; Adult; Child; Concanavalin A; Cystic Fibrosis; Electron Transport Complex IV; Female; Genetic Carrier Screening; Genotype; Homozygote; Humans; Luminescent Measurements; Male; Membrane Proteins; Monocytes; Oxidoreductases; Oxygen Consumption; Peroxidases

The role of B cells and regulatory T cells in the reduced in vitro IgG synthesis of cystic fibrosis (CF) patients was studied. Intact proportion, proliferation, and differentiation of B cells and reduced suppressor and helper T-cell function were found. To explore the T-cell defects further, CF sera or supernatant derived from Pseudomonas aeruginosa cultures (PA supernatant) was added to the relevant T helper- and suppressor-cell assays. Both CF sera derived from PA-positive patients and PA supernatant interfered with the appearance of interleukin 2 (IL-2) receptors and with the functional enhancement caused by exogenously added IL-2. PA-negative CF patients, however, also had functional T-cell defects and inhibitory sera, but these sera did not affect IL-2 pathways. Thus different serum factors and intrinsic T-cell defects in CF patients are suggested.

Topics: Adolescent; Adult; Antibody-Producing Cells; Antigens, Surface; B-Lymphocytes; Child; Child, Preschool; Concanavalin A; Cystic Fibrosis; Female; Humans; Immunoglobulin G; In Vitro Techniques; Infant; Interleukin-2; Interleukins; Lymphocyte Activation; Male; Phenotype; Pseudomonas aeruginosa; T-Lymphocytes; T-Lymphocytes, Regulatory

Although the basic biochemical defect in cystic fibrosis (CF) is unknown, previous studies have indicated that errors in protein glycosylation may be involved in the pathogenesis of the disease. Utilizing human skin fibroblasts, the present study was designed to quantitatively analyze glycosylation of cell surface glycoconjugates in CF and normal cells. Cell surface glycoconjugates were analyzed using 125I-concanavilin A (Con A), 125I-WGA, and Con A-ferritin conjugates. Under our binding conditions, Con A was used as a probe for mannose residues and WGA was used as a probe for N-acetylglucosamine residues. Saturable binding of both probes was observed and appropriate sugar controls confirmed the specificity of each lectin. When compared on a DNA basis, iodinated lectin binding studies indicated that no consistent differences existed between CF and normal strains of human skin fibroblasts. Ultrastructural quantitative morphometric analysis of Con A-ferritin conjugate binding indicated that neither proteolysis of cell surface glycoconjugates or internalization of lectin probes was occurring at saturable binding concentrations. In summary, our results indicated that no consistent differences in cell surface mannose and N-acetylglucosamine residues could be detected between the normal and CF strains of human skin fibroblasts used in these studies.

Topics: Acetylglucosamine; Binding Sites; Cell Line; Cell Membrane; Concanavalin A; Cystic Fibrosis; Ferritins; Fibroblasts; Glycoconjugates; Humans; Lectins; Mannose; Skin

The binding properties of two lectins, concanavalin A and wheatgerm agglutinin to membrane glycoproteins extracted from cystic fibrosis fibroblasts have been examined. No differences were found between the binding patterns of either of these lectins to cystic fibrosis and normal fibroblast glycoproteins. The amount of concanavalin A binding to a glycoprotein of approximate Mr 150 000 has been shown to be related to the population doubling time of a cell culture at the time of analysis.

Topics: Adolescent; Adult; Cell Membrane; Cells, Cultured; Child; Child, Preschool; Concanavalin A; Cystic Fibrosis; Fibroblasts; Glycoproteins; Heterozygote; Humans; Infant; Lectins; Membrane Proteins; Middle Aged; Staining and Labeling; Wheat Germ Agglutinins

It has previously been demonstrated that glucocorticoid suppression of mitogen-induced lymphocyte activation is a function of mitogen dose. Glucocorticoids suppress lymphocyte activation more at low doses, which induce suboptimal lymphocyte activation, than at higher doses which are optimal for lymphocyte activation. This observation suggests that glucocorticoid suppression of lymphocyte activation might be greater than normal in disease states which are associated with depressed mitogen-induced lymphocyte activation. To test this hypothesis, lymphocytes from normal individuals and patients with cystic fibrosis were activated by a full range of concentrations of concanavalin A (Con A) in the presence or absence of dexamethasone. Con A activation of cystic fibrosis lymphocytes was markedly depressed compared to the activation of normal lymphocytes at all doses of Con A, but the suppressive effect of dexamethasone on the activation of normal and cystic fibrosis lymphocytes was the same. We conclude that glucocorticoid suppression of lymphocyte activation is more a function of mitogen dose than of the level of lymphocyte activation and is not necessarily greater than normal in disease states which are associated with depressed mitogen-induced lymphocyte activation.

Topics: Adolescent; Adult; Concanavalin A; Cystic Fibrosis; Dexamethasone; Dose-Response Relationship, Immunologic; Humans; Immunosuppressive Agents; Lymphocyte Activation; Lymphocytes

The binding of the urinary lysosomal enzyme alpha-L-fucosidase to free- and Sepharose 4B-bound concanavalin A has been compared in cystic fibrosis (CF) patients and normal controls. The concentration of methyl-alpha-D-mannoside necessary to prevent 50% of total alpha-L-fucosidase activity to bind to free and bound concanavalin A (Ki, 50%) was similar for CF (0.68 +/- 0.20 and 1.3 +/- 0.3 mmol/l, respectively) and normal controls (0.53 +/- 0.18 and 1.9 +/- 0.5 mmol/l, respectively). The CF and normal urinary alpha-L-fucosidase also showed similar pH optima (4.8), Km, app (0.071 and 0.074 mmol/l, respectively) and thermodenaturation curves at 44 degrees C (t1/2 = 108 min). We report that the kinetic and the concanavalin A-binding affinity of alpha-L-fucosidase are similar from urine of cystic fibrosis patients and controls.

Topics: alpha-L-Fucosidase; Concanavalin A; Cystic Fibrosis; Hot Temperature; Humans; Hydrogen-Ion Concentration; Kinetics; Mannosides; Methylmannosides; Protein Denaturation; Sepharose

Lymphocytes isolated from cystic fibrosis patients chronically treated with beta-adrenergic agonists respond significantly differently to epinephrine modulation of mitogen challenge than either cystic fibrosis patients not receiving beta-adrenergic therapy or normal human volunteers. Those patients on chronic beta-adrenergic therapy are insensitive to the modulating effects of 1-epinephrine. This observation is discussed in terms of adrenergic receptor alteration and/or different cystic fibrosis disease states.

Topics: Adrenergic beta-Agonists; Concanavalin A; Cystic Fibrosis; Humans; In Vitro Techniques; Lymphocytes; Receptors, Adrenergic, beta

Topics: alpha-L-Fucosidase; Cells, Cultured; Concanavalin A; Cystic Fibrosis; Enzyme Activation; Humans; Immune Sera; Immunoassay; Kinetics; Lymphocytes; Methylmannosides; Molecular Weight; Reference Values

Topics: Adult; alpha-Macroglobulins; Concanavalin A; Cystic Fibrosis; Heterozygote; Humans; Immunoglobulin G; Immunoglobulin M; Lung Diseases; Protein Binding

Concanavalin A (Con A) binding sites and their mobility were studied by peroxidase (Po) and ferritin labeling techniques in normal and SV40 transformed human fibroblasts. Binding sites were visualized either as osmium black of 3'3-diaminobenzidine (DAB) reactions or as ferritin particles. DAB reaction products were localized at the external surface of the plasma membrane and in some multivesicular bodies of fixed cells. The labeling was continuous in normal and SV40 transformed human fibroblasts. When living cells were treated with Con A-Po at 4 degrees C and incubated at 37 degrees C, both normal and transformed cells showed remarkable changes. The foci of membrane indentations (caps or patches) are formed on the cell surface. Many labeled internalized vacuoles and vesicles appeared within the cytoplasm and in close proximity to the Golgi region of all cell types. The cellular changes occurred more quickly in transformed cells than in normal cells. It is concluded that normal cells do cap under certain conditions and that the plasma membranes of transformed cells are more fluid than those of normal cells.

Topics: Cell Line; Cell Membrane; Cell Transformation, Viral; Concanavalin A; Cystic Fibrosis; Fibroblasts; Humans; Microscopy, Electron; Receptors, Concanavalin A; Simian virus 40

Purified preparations of plasma alpha 2-macroglobulin from patients with cystic fibrosis are shown to have normal amounts of total hexose but as much as 40% decrease in their sialic acid content. The binding of these preparations to concanavalin A and wheat-germ agglutinin was markedly reduced as compared to normal values in controls. Intermediate values were found in obligate heterozygotes. These results suggest a possible alteration in the carbohydrate moiety of alpha 2-macroglobulin in cystic fibrosis, presumably due to a defective posttranslational process.

Topics: alpha-Macroglobulins; Concanavalin A; Cystic Fibrosis; Genetic Carrier Screening; Hexoses; Humans; Lectins; Sialic Acids

Topics: alpha-L-Fucosidase; Concanavalin A; Cystic Fibrosis; Humans; Kinetics; Liver; Protein Binding

Topics: Animals; Concanavalin A; Cystic Fibrosis; Exocrine Glands; Humans; Mucus; Rats

Lymphocyte responses to the mitogens phytohemagglutinin and concanavalin A and to Streptococcus pyogenes, Staphylococcus aureus, Haemophilus influenzae, and Pseudomonas aeruginosa were evaluated in patients with cystic fibrosis and in normal individuals. Lymphocyte proliferation in vitro was stimulated by gentamicin-killed whole bacteria, and the proliferative response was measured by [3H]thymidine incorporation. The in vitro lymphocyte responses to antibiotic-killed bacterial reached maximum thymidine incorporation after 5 days in culture and followed a unimodal dose-response curve for each of the bacteria studied. A significant specific incapacity to respond to P. aeruginosa was detected in cystic fibrosis patients with advanced clinical disease.

Topics: Antibodies, Bacterial; Antigens, Bacterial; Concanavalin A; Cystic Fibrosis; Haemophilus influenzae; Humans; Lectins; Lymphocyte Activation; Pseudomonas aeruginosa; Staphylococcus aureus; Streptococcus pyogenes

Concanavalin A (Con A) binding sites were visualized ultrastructurally in the cultured fibroblasts from cystic fibrosis patients, obligatory heterozygotes, and normal individuals by peroxidase labeling technique. Con A binding sites were localized as a continuous layer on the external side of the plasma membrane in fixed fibroblasts of the three genotypes. In living cells, Con A induces both lateral and vertical movements of binding sites as expressed by cap formation and internalization of the plasma membrane. Fibroblasts of the three genotypes responded similarly to Con A treatment and failed to show significant detectable differences.

Topics: Binding Sites; Concanavalin A; Cystic Fibrosis; Fibroblasts; Heterozygote; Histocytochemistry; Homozygote; Humans; In Vitro Techniques; Temperature

An alpha-feto-protein (AFP) is present in many mammals, in birds, and in sharks during development. The AFP present in different species have similar physicochemical properties and often have common antigenic determinants. Their study, both in health and disease, has provided a useful model for the understanding of other phase-specific antigens and the activation of the genes which control their synthesis. In the human fetus, the level of AFP falls with increasing maturity. The more sensitive methods of detection have disclosed that this fetal protein persists in trace amounts throughout life and its level increases in maternal blood during pregnancy. The principal sites of synthesis are the fetal liver and in some mammals, the yolk sac splanchnopleur. In humans as well as in mice and cows, it is notable that the synthesis of AFP is increased in liver cancer cells and that high levels of this protein are present in serum. Elevated values of AFP have also been detected in human subjects with undifferentiated tumours of the testis and ovary. A fall to normal levels has been noted in cases of complete remission after surgery and a return to high levels in patients who develop metastases. In some patients with hepatitis a temporary rise in the level of AFP has also been observed. In recent years, the detection of high levels of AFP in amniotic fluid has proved to be of great value for the prenatal diagnosis of neural-tube defects. Abnormal levels have also been found in the amniotic fluid or in maternal serum in cases of spontaneous abortion. Such measurements are now being assessed as a methodof monitoring abnormal pregnancy.

Topics: alpha-Fetoproteins; Amniotic Fluid; Anencephaly; Animals; Antigen-Antibody Reactions; Carcinoma, Hepatocellular; Concanavalin A; Cystic Fibrosis; Down Syndrome; Female; Fetal Proteins; Gastrointestinal Neoplasms; Gestational Age; Hepatitis; Humans; Immunologic Techniques; Infant, Newborn; Liver; Liver Neoplasms; Metabolism, Inborn Errors; Neoplasm Metastasis; Neoplasms, Experimental; Pregnancy; Spinal Dysraphism; Teratoma