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H Rumpold

Publications and source records attributed to H Rumpold.

102 records · Page 6Linked to original sources
PubMed1982

A ganglioside-dependent cellular binding mechanism in rat macrophages.

A rosetting assay was performed with rat alveolar and peritoneal macrophages and sheep red blood cells (SRBC) treated with gangliosides. SRBC incubated with GM2, GD1a, and a mixture of bovine brain gangliosides (BBG) showed binding to rat macrophages. The extent of binding was dependent on the concentration of gangliosides. Binding induced by GM2 was stronger than that induced GD1a and BBG. GM1 and GA2 did not induce rosette formation. Inhibition studies with gangliosides, sialyllactose, lactose, and neuraminic acid suggested that the macrophage binding site recognizes neuraminic acid in conjunction with neighboring carbohydrates showing highest affinity for GM2. Sodium azide, sodium fluoride, ethylenediaminetetraacetate, cytochalasin B, and colchicine did not inhibit rosette formation. The percentage of peritoneal macrophages binding ganglioside-treated SRBC was lower than that of alveolar macrophages. Proteose-peptone-stimulated peritoneal macrophages, however, showed an increase of rosette formation. Around 30% of adherent spleen cells also had binding activity for GM2-treated SRBC. Peripheral blood mononuclear cells did not bind ganglioside-treated SRBC. Phagocytosis of GM2-treated SRBC attached to alveolar macrophages could not be observed. It is suggested that macrophages may express recognition sites for certain gangliosides that might be important in cell-cell interaction.

Animals↗
PubMed1981

Comparison between human IgM and IgG antibodies to dextran, regarding their activities in antibody-dependent cellular cytotoxicity (ADCC).

Human sera containing dextran-reactive antibodies of various immunoglobulin classes were tested for their capacity to induce ADCC against dextran-coated chicken red blood cells (CRBC). It was found that only IgG antibodies were active in ADCC, while IgM antibodies were not, thus providing further evidence that IgM antibodies do not contribute to ADCC even when human antibodies are used.

Animals↗
PubMed1981

Radioallergosorbent test with conjugates specific for 'minor' haptenic determinants in the diagnosis of IgE-mediated penicillin allergy in man.

Penicillamine-polylysine, benzylpenicillanyl-human serum albumin and ampicillin-polymers were coupled to CNBr-activated paper discs and used in addition to penicilloyl G and penicilloyl V discs in RAST investigations. Sera from sixty patients with case histories of penicillin allergy and with positive or negative skin tests to different penicillin determinants and from seventeen subjects with atopic diseases caused by allergens other than penicillin were tested. The penicilloyl-('major' determinant) specific RAST (Phadebas RAST Penicilloyl G and V) was positive in twenty out of twenty-four patients with positive skin tests to penicilloyl-polylysine, in eight out of twelve patients with sole skin reactivity to 'minor' determinants, and in five out of twenty-four patients with negative skin tests to all antigens used. The penicillamine-specific RAST was the only positive in vitro test in four patients with negative skin tests (two) or sole positive skin reactivity to 'minor' determinants (two), whereas benzylpenicillanyl and ampicillin-polymer discs added no more information than the penicilloyl structures in all patients tested. Antibodies specific to 'minor' determinants apparently show strong in vitro cross-reactivity with the penicilloyl determinant. It is, therefore, concluded that 'minor' determinant specific conjugates are of marginal importance for in vitro diagnosis of penicillin-allergic patients.

Benzeneacetamides↗
PubMed1981

Lack of evidence for IgM-induced ADCC: studies with monoclonal and polyclonal antibodies.

Different kinds of IgM antibodies were tested for their activity in antibody-dependent cellular cytotoxicity (ADCC): firstly an anti-benzylpenicilloyl (BPO) IgM antibody from immune rabbit serum purified by affinity, ion exchange, and molecular-sieving chromatography, secondly two monoclonal rat anti-BPO IgM antibodies and thirdly a human antidextran antibody prepared from a patient showing restriction of anti-dextran antibodies to the IgM class. Human lymphocytes or purified monocytes served as effector cells. While the two monoclonal rat and the human IgM antibodies showed no ADCC-mediating capacity, ADCC was induced by the rabbit anti-BPO IgM antibody when high antibody concentrations were used. This activity was abolished by further purification using an anti-rabbit IgG (Fc) immunosorbent. The initially observed activity was shown to be likely due to traces of aggregated anti-BPO IgG, which cannot be detected by the methods commonly used. Preincubation of lymphocytes for 24 hr increased the number of EA (IgM)] rosette forming cells but failed to induce IgM-mediated ADCC. Furthermore, evidence for amplification of low-dose IgG-ADCC by IgM could not be found.

Antibodies↗
PubMed1980

[K (killer) and NK (natural killer) cells: characteristics, functions and biological properties (author's transl)].

Cell-mediated cytotoxicity is considered to be an important defence system of the body in the case of virus diseases, transplant rejection and in the early stages of cancer. Apart from T lymphocytes, two types of effector cells which lyse tissue culture cells by different mechanisms have been investigated intensively over the past decade--K (killer) and NK (natural killer) cells. K cells possess the capacity to lyse antibody-coated target cells. These effector cells have been described to occur mainly in peripheral blood and spleen. They are small lymphocyte-like cells which possess receptors for the Fc part of immunoglobulin G. Other surface markers may be present on these cells, depending on the organ of isolation. Other cytotoxic effector cells with similar morphology and surface markers possess the capacity to lyse tissue culture cells without participation of antibody and without in vitro or in vivo sensitization. These cells are called NK cells and are found in peripheral blood, spleen, tonsils and lymph nodes. Up to now neither type of effector cells has been unequivocably identified as mature B or T cells, granulocytes, monocytes or macrophages. Differences exist between the effector mechanisms of K and NK cells, as shown by different susceptibility to modulation of effector cell function by cortisone and, probably, by interferon. Whether K and NK cells represent functional stages of identical cells and furthermore, whether these cells belong to a third lymphocyte population or represent immature mononuclear cells are questions remaining to be clarified.

Animals↗
PubMed1980

Modulation of NK and K cell activity by trypsin treatment of effector cells.

The effect of trypsin-treated human peripheral blood lymphocytes on spontaneous cell-mediated cytotoxicity (SCMC) and antibody-dependent cellular cytotoxicity (ADCC) was investigated using benzylpenicilloyl (BPO)-coated HeLa cells as targets. For ADCC-experiments an anti-BPO-IgG was purified from rabbit hyperimmune sera by affinity and subsequent ion exchange chromatography and used in different concentrations. After treatment of lymphocytes with high enzyme concentrations (21,500 U/2 X 10(6) lymphocytes/ml) both SCMC (mediated by NK cells) and ADCC (mediated by K cells) were markedly reduced in 3 hours as well as 18 hours 51Cr-release assays. Since decrease of K cell activity in this kind of assay might be due to impairment of SCMC, the effect of trypsin treatment was reevaluated in an NK-free system using BPO-coated lymphocytes as target cells and lymphocytes from the same donor as effector cells. Once again, in this system the K-cell activity was significantly reduced. Chessboard titration resulted in either enhancement of depression of ADCC depending on the dose of enzyme and IgG concentrations. In addition it could be seen from these dose response studies with different IgG concentrations (10--10,000 ng/ml) and different proteolytic activities (170--21,500 U/2 X 10(6) lymphocytes/ml) that the use of high IgG concentrations and low proteolytic activities might simulate resistance of K cells to trypsin treatment. The data presented indicate that the IgG-mediated ADCC should no longer be designated as "trypsin-resistant".

Animals↗
PubMed1980

Enhancement of NK, but not K cell activity by different interferons.

Two different interferons derived either from a human lymphoblastoid cell line (Namalva) or from human fibroblasts were tested for their ability to modulate natural killer (NK) or killer (K) cell activity. The lymphoblastoid interferon was purified by ion-exchange chromatography on SP-Sephadex C-25 and gel filtration on Sephadex G-100, the fibroblast-derived interferon was purified by chromatography on porous glass beads. Evidence is presented that NK cell activity is enhanced by both of these interferons being active to a similar extent. When tissue culture cells are employed as targets for measurement of K cell activity, the augmentation of cytotoxicity by interferons has to be attributed to the inherent NK cell activity. With the use of the autologous hapten-coated target cells and of affinity chromatography purified antibodies, the cytotoxicity is displayed solely by K cells and this activity is not enhanced by either interferons tested.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1978

[Lung irrigation].

A segmental bronchus is washed with normal saline solution by bronchoscopy. The lavage fluid is collected by aspiration. Lavage is performed to obtain free cells (lymphocytes, alveolar macrophages) for cell culture and specimens for immunological investigations.

Alveolitis, Extrinsic Allergic↗
PubMedDate not supplied

A shared antigenic determinant between natural killer cells and nervous tissue.

Considerable evidence for shared antigenic determinants between nervous elements and lymphocytes has accumulated. It has also been suggested that this cross-recognition may be involved in the pathogenesis of human neurological diseases such as myasthenia gravis and multiple sclerosis. We report here evidence that a marker for natural killer (NK) cells, anti-Leu-7 (HNK-1), specifically binds to components of human and rodent central nervous tissue as well as peripheral nervous tissue, especially to myelin sheaths. In contrast, another NK-cell marker (VEP13) did not react with nervous tissue. Since NK-cell function is impaired in a population of multiple sclerosis patients, the observed cross-reactivity indicates that autosensitization against myelin may simultaneously cause a defect of NK-cell function. Furthermore, the shared antigenic determinant may help to identify a hitherto undefined nervous tissue antigen and simultaneously increase the knowledge about the nature of NK-cell antigens.

Animals↗