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M R Capobianchi

Publications and source records attributed to M R Capobianchi.

At least 73 records · Page 4Linked to original sources
PubMed1988

Evidence that defective gamma interferon production in patients with primary immunodeficiencies is due to intrinsic incompetence of lymphocytes.

We have selected 11 patients with primary immunodeficiency disorders predominantly affecting T lymphocyte function (four with ataxia-telangiectasia (AT), four with common variable immunodeficiency (CVI) and one each with Wiskott-Aldrich syndrome, hyper-IgE syndrome and combined immunodeficiency) with defective gamma interferon (IFN-gamma) production in vitro. Induction with phytohaemagglutinin showed low interleukin 2 (IL-2) production concomitant with reduced IFN-gamma titres. However the addition of 10 U/ml of rIL-2 to cultures stimulated with staphylococcal enterotoxin B or galactose oxidase failed to restore IFN-gamma production in defective cases. IFN-gamma was titrated by both bioassay and immunoradiometric assay, ruling out the possible release of inactive or altered IFN-gamma molecules. Normal levels of IFN-gamma were found in patients of patients with AT, as well as in two AT and two CVI cases, demonstrating heterogeneity of defects within these syndromes. Soluble inhibitors or cellular suppression of IFN-gamma were not observed in mixing experiments. The possibility that defective interaction between accessory cells and T lymphocytes might account for the poor response to the inducing agents was ruled out as no IFN-gamma was produced using a calcium ionophore--which bypasses this step--in seven patients with absolute IFN-gamma deficiency.

Ataxia Telangiectasia↗
PubMed1988

HLA-D region antigens on isolated human colonic epithelial cells: enhanced expression in inflammatory bowel disease and in vitro induction by different stimuli.

Colonic epithelial cells (CEC) were isolated from actively inflamed mucosa of IBD patients and checked for HLA-DR, HLA-DP, and HLA-DQ. Half of the freshly isolated CEC from IBD tissue expressed DR, and one third were positive for DP and DQ. Normal human CEC were then cultured for 24 h and their expression of these markers in response to different types of in vitro stimulation was investigated. A significant increase in the expression of DR, DP and DQ was observed in response to the nonspecific mitogen phytohaemagglutinin (PHA), the lymphokine gamma-interferon (gamma-IFN) and the epidermal growth factor (EGF). The enhancement of DR expression was more marked than that of DP and DQ. The effect of gamma-IFN was more rapid and significantly more marked than that of either PHA and EGF for all three antigens. EGF appeared to be more potent than PHA in enhancing the expression of DP and DQ. The data from this study indicate that HLA-D region antigens can be induced on human CEC by different types of stimuli and provide further evidence that the expression of these markers in the colonic epithelium is a normal event the magnitude of which can increase under various circumstances. The data also suggest that the increased expression of HLA-D region antigens by IBD CEC occurs as a result of different mechanisms, and that this expression is an indicator of the active participation of the colonic epithelium to the mucosal inflammatory response.

Cells, Cultured↗
PubMed1987

Membrane interactions involved in the induction of interferon-alpha by Mycoplasma pneumoniae.

Interferon (IFN) induction by Mycoplasma pneumoniae (MP) in human peripheral blood mononuclear cells (PBMC) has been studied. We show that IFN yields depend on the concentration of both lymphocytes and MP. The effective IFN inducer appears to be the mycoplasma membrane, and IFN production occurs without significant lymphocyte proliferation. Data obtained by both positive and negative selection experiments suggest that the PBMC subpopulation induced by MP is B lymphocyte, as opposed to the main subpopulation induced by NDV that is monocyte. Evidence is also provided suggesting that the membrane interaction between MP and the B cells is mediated by MHC Class II antigens.

B-Lymphocytes↗
PubMed1986

In vitro interferon production: induction in human leukocytes after exposure to cytomegalovirus antigens.

In vitro lymphocytes from healthy donors with crude (HCMV), heat inactivated (HCMVi) and infected human fetal fibroblasts (HCMVFF) were stimulated. In all the experiments peak titers of alfa Interferon (IFN) were present 24 h after exposure to antigens. On the other hand, at least after seven days, only lymphocytes of seropositive donors stimulated by HCMVFF and HCMV showed gamma IFN production. Our HCMVFF gave much higher IFN yields than free virus. Our data suggest that HCMVFF and HCMV are recognised by lymphocytes of HCMV specific memory and HCMVFF give additional and more reproducible information on HCMV specific cellular immunity.

Antigens, Viral↗
PubMed1985

Differences in the expression and release of DR, BR, and DQ molecules in human cells treated with recombinant interferon gamma: comparison to other interferons.

This study presents a comparative analysis of the effects of different interferons (IFN) on the three recognizable subsets of human HLA class II molecules: DR, BR, and DQ. Both cellular expression and shedding of class II molecules have been determined on three different cell types. The results can be summarized as follows: class II molecules are markedly increased by IFN gamma; IFN beta has a lower enhancing effect, and IFN alpha has only a slight, if any, effect. Kinetically, the action of IFN gamma is prompter and longer lasting than that of IFN beta. DQ expression is much more enhanced by IFN gamma than either DR or BR; IFN beta has the same effect on all three subsets. Parallel changes of the cellular expression and of the shedding of these molecules are observed. A melanoma and a lymphoblastoid cell line and peripheral blood mononuclear cells show qualitatively similar modifications.

B-Lymphocytes↗
PubMed1985

Group B coxsackieviruses readily establish persistent infections in human lymphoid cell lines.

Exposing human lymphoid cell lines to uncloned or recently cloned group B coxsackieviruses results in the frequent establishment of chronically infected cultures. Persistence is maintained by a carrier culture mechanism involving virus spread through the medium and replication among a minority of cells at any given time. These studies provide a model for persistence by highly cytocidal viruses.

Cell Line↗
PubMed1985

Membrane events leading to interferon-gamma induction by antigens.

Mitogenic induction of interferon-gamma in human peripheral blood mononuclear cells (PBMC) is prevented by enzymatic cleavage of galactose residues on the cell membrane, and by calcium depletion, suggesting that oxidation of galactose on the membrane glycoproteins and activation of a calcium flux across the membrane are critical events for interferon-gamma induction in nonspecifically stimulated human PBMC. The same experimental design has been applied to human PBMC cultures enriched of specifically sensitized lymphocytes and stimulated with the respective antigens. The results of these experiments show that also antigenic induction of interferon-gamma by purified protein derivative, tetanus toxoid, and MLR requires integrity of galactose residues and calcium intake suggesting that alteration of membrane-bound galactose and activation of a calcium flow are critical triggering events for both specific and nonspecific lymphocyte activation.

Adult↗
PubMed1985

Induction of alpha interferon by membrane interaction between viral surface and peripheral blood mononuclear cells.

Cells infected with viruses and fixed when viral antigens appeared at the cell membrane induced much higher alpha interferon (IFN-alpha) levels in human peripheral blood mononuclear cells (PBMC) than free virions. Relatively few inducer cells were sufficient for triggering IFN production. Optimal IFN yields depended on inducer/producer cell ratio. The response was peculiar to PBMC as it was not found in other cells in which IFN can normally be induced by free virions. IFN inducing activity was also exerted by live virus-infected PBMC, showing that this type of induction may have physiological importance. These findings confirm that viral induction of IFN-alpha is activated by some interaction between viral components presented at the cell surface and PBMC membrane. Thus induction of IFN by circulating cells infected by viruses and presenting viral antigens at the surface may be an efficient host defense mechanism. Since IFN yields close to 10(6) international units per milliliter are obtained, this system has potential for large scale production of native IFN-alpha.

Animals↗
PubMed1984

Interferon production in primary immunodeficiencies.

Alpha- and gamma-interferon (IFN) production by peripheral blood mononuclear cells (PBMC) from 18 patients affected by primary immunodeficiency syndromes was examined and compared with that of 20 normal donors. Patients included 8 with common variable immunodeficiency (CVI), 2 with congenital agammaglobulinemia, 4 with ataxia-telangiectasia, 2 with hyper-IgE syndrome, 1 with chronic EBV infection, 1 with combined immunodeficiency, and 1 with immunodeficiency with hyper-IgM. No spontaneous IFN production was observed in either patients and controls. Newcastle disease virus-induced alpha-IFN production was found to be normal in all patients. Gamma-IFN was induced by both galactose oxidase and staphylococcal enterotoxin (B). Gamma-interferon production was low or undetectable in patients with ataxia-telangiectasia, in immunodeficiency with hyper-IgM, and in hyper-IgE syndrome. No major defect of gamma-IFN was found in other types of immunodeficiency, despite the presence of occasional low producers (1 of 8 CVI patients and 1 case of congenital agammaglobulinemia). No correlation was found between IFN production and natural killer activity in individual patients. The analysis of lymphocyte subsets by monoclonal antibodies revealed gross imbalances of helper/inducer and suppressor/cytotoxic subpopulations, but no overall correlation could be established with gamma-IFN production. The observation of major defects in gamma-IFN yield only in diseases with depression of T cell-mediated immunity might contribute to a better understanding of the pathogenetical mechanisms in these diseases. Moreover, future studies should monitor these in vitro functions and their modifications by in vitro or in vivo manipulations.

Adolescent↗
PubMed1984

Defective interferon-gamma production in ataxia-telangiectasia.

The in vitro production of interferon-alpha and -gamma (IFN) by peripheral blood mononuclear cells from four patients with ataxia-telangiectasia was compared to that of healthy controls. Normal values of IFN-alpha were obtained in all cases. However, patients with ataxia-telangiectasia showed a great reduction or absence of IFN-gamma production after induction with either staphylococcal enterotoxin B or galactose oxidase. This defect was accompanied by the absence of secretion of another lymphokine, namely, interleukin 2 (IL-2), in one case. Lymphoproliferative response to phytohemagglutinin (PHA) was severely depressed in all patients. Near normal values of T lymphocytes were found, but the ratio of OKT4+/OKT8+ subsets was reduced in most patients, due to a decrease of OKT4+ lymphocytes. Deficiency of IFN-gamma may contribute to the abnormalities of immune functions and immunoregulation observed in ataxia-telangiectasia, and it may represent an additional cause of the high incidence of viral infections and neoplasia in this disease.

Adolescent↗
PubMed1984

Role of calcium in gamma interferon induction: inhibition by calcium entry blockers.

Mitogen-induced gamma interferon production by human lymphoid cell cultures was studied in the presence of calcium entry blockers. A dose-dependent inhibition was found in the presence of drug concentrations down to 10(-5) M. This finding shows that calcium flow through lymphocyte membranes after oxidation of membrane-bound galactose residues is also critical for triggering interferon production.

Calcium↗
PubMed1983

Human interferon-gamma enhances the expression of class I and class II major histocompatibility complex products in neoplastic cells more effectively than interferon-alpha and interferon-beta.

Human interferon-gamma was more effective than interferon-beta or -alpha in stimulating production of immunoassociated antigens; HLA-A, -B, and -C; and beta(2)-microglobulin in human M14 and Namalva cells. The comparison was made on the basis of antiviral units, and the stimulation could be abolished by treatment of the interferon-gamma preparation with pH 2 or anti-interferon-gamma serum.

Animals↗
PubMed1983

Differential effects of gamma interferon on expression of HLA class II molecules controlled by the DR and DC loci.

Interferon-gamma affected the expression of the products of the immunoassociated antigen complex by a differential modulation of DR- and DC-locus-controlled molecules. In melanoma M14 cells treated with interferon-gamma, levels of DR molecules were increased two- to threefold, whereas levels of DC molecules were increased six- to sevenfold. Similar effects were induced on the two allelic products of each locus.

Cell Line↗