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D S Matheson

Publications and source records attributed to D S Matheson.

29 records · Page 2Linked to original sources
PubMed1986

T lymphocytes from hemophiliacs proliferate after exposure to factor VIII product.

Chronic exposure of hemophiliacs to allogeneic proteins via factor VIII concentrate for control of bleeding could lead to a state of chronic antigen stimulation. Immune function from eight hemophiliacs requiring large amounts of factor VIII concentrate was assessed. It was found that 5 of 8 had a positive blastogenic response to low concentrations of factor VIII in a 7-day thymidine uptake assay. Separation of lymphocyte subpopulations indicated that the reactivity was contained in the T cell-enriched fraction. There was no blast transformation noted secondary to the factor VIII product in 20 controls tested in a 7-day assay nor was there any mitogenic effect of the factor VIII in a 3-day assay. In fact, high concentrations of factor VIII impaired that T lymphocytes from hemophiliacs are antigenically primed to some constituent in the lyophilized factor VIII concentrate.

Adult↗
PubMed1986

Natural killer cell activity from hemophiliacs exhibits differential responses to various forms of interferon.

Patients with hemophilia are at risk for the development of acquired immunodeficiency syndrome (AIDS). Patients with AIDS have recurrent infections and/or malignancy and altered immune response, including decreased T lymphocyte counts, decreased T helper lymphocytes, defective T cell blastogenesis, hypergammaglobulinemia, defective natural killer (NK) activity and impaired response of NK to interferon-beta (IFN-beta). It is feasible that chronic antigen stimulation with subsequent release of interferon could be related to the impaired NK reactivity to IFN-beta of patients with AIDS. Because hemophiliacs are subjected to chronic antigen stimulation secondary to the administration of foreign protein, the reactivity of NK cells from patients with hemophilia to IFN-alpha, IFN-beta and IFN-gamma was studied. Eight patients with hemophilia requiring high levels of clotting factor replacement were assessed. Three patients were antibody positive to HTLV-III. All had normal baseline NK cell function. In the first set of experiments, all patients responded normally to in vitro IFN-alpha by increasing NK activity, but four patients had significant failure and two had mild impairment in NK response to IFN-beta. This latter observation was particularly evident at very low concentrations of IFN. In repeated experiments, seven of eight had impaired NK response to IFN-beta and IFN-gamma but normal response to IFN-alpha. Only one patient's NK cells responded better to IFN-gamma. There was no obvious correlation of these findings to antibody status to HTLV-III. Chronic antigen stimulation and the modulation of interferon receptors are discussed as possible mechanisms that could produce these findings.

Adult↗
PubMed1984

Effect of D-glucosamine on human natural killer activity in vitro.

D-Glucosamine has been shown in animal studies to have selective tumoricidal activity. In human cancer patients, preliminary data indicate that natural killer (NK) activity is increased secondary to D-glucosamine infusion. The present study examined the effect of D-glucosamine on several in vitro indices of human immune responsiveness including NK cell activity and T and B cell mitogenesis. NK activity in normal human peripheral blood mononuclear cells was significantly elevated in the presence of 10(-4) and 5 X 10(-4) M D-glucosamine. The increment in NK activity was mediated by nonadherent effector cells and was not due to an increased susceptibility of target cells. Analysis by single-cell assay indicated that the number of effector/target conjugates was not increased but that there was increased lytic activity of the NK cells. Previous studies from our laboratory indicated that several drugs which perturb thymidine (TdR) metabolism were effective in enhancing the in vitro NK activity. As D-glucosamine has been observed to alter cellular pyrimidine nucleotide pools and TdR metabolism in tumor cells, the effect of exogenous TdR was assessed on D-glucosamine-stimulated NK activity. Exogenous TdR inhibited D-glucosamine-induced augmentation of NK activity in a dose-dependent manner and completely abrogated the drug response at 10(-7) M. Similar experiments indicated that TdR did not affect the interferon-induced augmentation of NK activity in concentrations up to 10(-4) M. Although human NK activity was enhanced by D-glucosamine in vitro, there was no change induced in T or B lymphocyte mitogenesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Cells, Cultured↗
PubMed1982

Further studies of natural killer cell function in Chediak-Higashi patients.

Spontaneous natural killer (NK) activity and antibody-dependent cellular cytotoxicity (ADCC) of blood lymphocytes against five human tumour cell lines (K562, Molt-4, HL-60, Chang, Daudi) and three mouse tumour lines (YAC, P815, RBL-5) were ten- to 100-fold lower than normal in six patients with Chediak-Higashi (CH) disease. NK and ADCC were defective at 4 hr, and less so at 18 hr. The NK activity in normals and CH patients was mediated in part by FcR+, E- effector cells. ADCC against human erythrocytes was normal in CH patients, as were lectin-dependent cytolysis and mixed lymphocyte proliferative responses. Phagocytosis of antibody-coated ox erythrocytes was normal in CH patients as well. These observations confirm that the CH syndrome is associated with a profound and selective defect in NK and ADCC activity against tumour cells, whereas other mononuclear cell-mediated functions are normal.

Adult↗
PubMed1979

Abnormal lymphocyte capping in a patient with severe combined immunodeficiency disease.

Despite the presence of normal numbers and distribution of T and B lymphocutes and normal levels of serum immunoglobulins, a five-month-old infant failed to show any evidence of T-cell or B-cell immunity. In trying to identify a specific membrane abnormality as a potential cause of the immunologic dysfunction, we examined the lateral mobility of the cell-surface receptor for concanavalin A. In contrast to normal cells, in which the receptor is distributed uniformly over the cell surface, the patient's lymphocytes showed an unusually high accumulation of concanavalin A receptors in surface caps. This capping abnormality appeared in both T and B lymphocytes and was exaggerated by colchicine, an inhibitor of microtubule assembly. These findings support the theory that plasma-membrane-cytoskeleton interactions have a role in the expression of specific immunity; the findings also identify new areas that should be considered in trying to understand the primary immunodeficiency diseases.

B-Lymphocytes↗
PubMedDate not supplied

The influence of recombinant mediators on in vitro IgG subclass secretion by peripheral blood mononuclear cells from patients with hypogammaglobulinemia and from normal donors.

Patients with hypogammaglobulinemia have recurrent infections and fail to produce protective antibodies. In order for B cells to mature into antibody producing cells, several other cell types such as macrophages and helper T lymphocytes must be involved. They secrete several mediators such as interleukin-1 (IL-1), IL-4, IL-5, IL-6 and interferon-gamma (IFN-gamma). These factors, as recombinant mediators, were tested to assess their ability to correct the immunoglobulin production defect in vitro from pokeweed mitogen (PWM) stimulated cultures of peripheral blood mononuclear cells (PBMC) from 11 patients with hypogammaglobulinemia, and from 10 normals as controls. In general, PBMC from hypogammaglobulinemic patients secreted very little Ig in cultures, and no mediator induced a statistically significant increase in the secretion of any IgG subclass. When assessed on an individual basis, one patient demonstrated a variable pattern of increase in total IgG, IgG1, and IgG3, secretion induced by various mediators, to within one standard deviation of the average secretion of normal PBMC cultured in PWM. In the case of the normal cells, IL-4, IL-6 and IL-1 plus IL-4 were able to increase IgG2 secretion in culture with PWM. No increase in secretion of IgG1, IgG3 and IgG4 or total IgG was demonstrable however. Hence, although there is variability in responsiveness amongst the patients, there does not appear to be any one of these recombinant mediators which will correct the defect.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗