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O Scheiner

Publications and source records attributed to O Scheiner.

At least 199 records · Page 11Linked to original sources
PubMed1983

Conditions for the enhancing effect of protease inhibitors on the concanavalin A induced thymidine response of murine lymphocytes.

Incorporation of [3H]-thymidine - [3H]-TdR - into concanavalin A (Con A) stimulated murine splenocytes and thymocytes was found to be enhanced by addition of certain concentrations of phenyl-methylsulfonylfluoride (PMSF), di-isopropylfluorophosphate (DFP), N-alpha-tosyl-L-lysyl-L-chloromethylketone (TLCK), and soybean trypsin inhibitor (SBTI). No enhancement could be observed when mononuclear cells of the peripheral blood were used, and a medium enhancement when thymocytes were applied. Furthermore, no enhancing effect of the protease inhibitors (PI) on the Con A response of murine splenocytes could be observed within the first 24 h of the culturing period. DFP, PMSF, and TLCK enhanced the Con A response to a similar degree, whereas SBTI was less effective. DFP and SBTI proved to be also effective when they were added after 15-24 h to the Con A cultures, if the cultures were harvested 48 h later. Removal of adherent and phagocytic spleen cells or reduction of the concentration of spleen cells shifted the effective DFP concentration to lower concentrations, whereas addition of adherent spleen cells caused a shift of the enhancing DFP amounts to higher concentrations. The data presented suggest that the enhancing effect of PI on the T cell response depends on the concentration of PI, the time of culturing and incubation, the PI used, the origin of the stimulated cells, and especially on the number of adherent and phagocytic cells. These findings might explain - at least in part - the different results on the effect of PI on the T cell response obtained in the past.

Animals↗
PubMed1983

[Entamoeba histolytica: I. Mechanism of cytotoxic activity].

Cytotoxic action against K562-tissue culture cells was investigated under various conditions with a Chromium-release-assay. When amoebae and target cells were centrifuged together, pathogenic strains of amoebae induced a very fast increase of target cell lysis (up to 50% of maximum lysis after 10 minutes). Only a minor degree of target cell lysis resulted, however, when amoebae and K562 cells were kept in suspension. When amoebae were eliminated selectively by addition of complement 10 minutes after starting the experiment, this fast increase of lysis could not be prevented. These observations suggest that the cytotoxic action might take place in two distinct phases. The first step ("lethal hit") seems to be temperature-independent, whereas a temperature of 37 degrees C is necessary for the second step to occur during which cytoplasmic material is released (chromium release). The presence of amoebae is not necessary for the second step. When amoebae together with and target cells are kept in suspension, amoebae lost their capability of setting the "lethal hit" with increasing time of coincubation. It seems, as if the "lethal hit" cannot be accomplished effectively under the conditions of suspension: cytotoxic substances released by the amoebae cannot be transferred to the target cells and are lost in the fluid phase. Thereby, the amoebae are depleted of such substances. Thus, a stable contact between amoebae and target cells for at least a few minutes seems to be necessary for the expression of cytotoxicity.

Amebiasis↗
PubMed1982

Differential effect of low molecular weight alcohols on the Con A stimulation of mouse spleen cells.

Incorporation of [3h]thymidine ([3H]TdR) into concanavalin A (Con A)-stimulated murine splenocytes was found to be enhanced by addition of certain concentrations of ethanol, 2-propanol and acetone. The alcohol/acetone-induced enhancement of the Con A response was found to be accompanied by an increase of the percentage of living cells as assessed by trypan blue exclusion. Concentrations of ethanol and 2-propanol which caused maximum [3H]TdR uptake in Con A cultures were also found to lead to higher percentages of aggregated cells than in comparison to Con A cultures without alcohol. The data suggest that alcohols in certain concentrations are capable to achieve optimum Con A stimulation.

Alcohols↗
PubMed1982

Immunoglobulin class and subclass distribution of dextran-reactive antibodies in human reactors and non reactors to clinical dextran.

The red cell-linked antigen-antiglobulin reaction (RCLAAR) with stearoyldextran-coated erythrocytes was used to characterize the immunoglobulin (Ig) classes and IgG subclasses of dextran reactive antibodies (DRA) in 27 dextran reactors (DR) and 96 on reactors (DNR). High titres of dextran reactive IgG were regularly found in sera of patients with severe dextran-induced anaphylactoid/anaphylactic reactions (DIAR) prior to the infusion. In four lethal cases IgG antibodies were found to be in the highest titre range of 16,384 to 32,768. In addition, high IgA and IgM titres were also in severe DIAR. DNR had much lower titres of dextran reactive antibodies of IgG, IgM and IgA classes and IgD antibody was absent in both groups. Dextran reactive IgE antibodies were not demonstrable in DR. Dextran reactive IgG2, IgG3, IgG4 and IgG1 (indirect measurement) were demonstrated in both DR and FNR. Dextran infusion caused variable neutralization in all Ig classes and IgG subclasses, but the contribution of IgG2 was considered most important because of its high titres and most pronounced neutralization in severe DIAR. It is concluded that DRA mainly of the IgG class, play a critical pathogenic role in the induction of severe DIAR, which accordingly is classified as immune complex (Type III) anaphylaxis. The method of RCLAAR allows to delineate a risk group of about 2% of potential reactors.

Adolescent↗
PubMed1982

A comparative evaluation of receptor reactivities for C3b, iC3b, and C3d on Raji lymphoblastoid cells.

Raji cells were described to carry receptors for iC3b, C3d, C3b-beta 1 H and beta 1 H. Controversial opinions, however, exist whether or not these cells carry also receptors for C3b. Using highly purified C3, definitely devoid of beta 1 H and C5, for preparation of C3b intermediates, it could be shown that Raji cells bound to C3b cells. Furthermore, Raji cells reacted with monoclonal antibodies that interfered with binding of C3b to human erythrocytes, lymphocytes and renal cells. The receptor for C3b on Raji cell, however, exhibited some special properties and, therefore, required some distinct experimental conditions for its detection: (1) The origin of the erythrocytes used for preparation of the C3b intermediates seemed to be important; this was not the case when iC3b and C3d receptor reactivity was assessed. (2) Rosettes already formed between Raji cells and EAC1423b showed the tendency to disintegrate within the first 30 min after the rosette formation assay. Again, this effect could not be observed with iC3b- and C3d-dependent rosette formation. (3) Incubation of the Raji cells at 37 degrees C as well as 4 degrees C before rosette formation resulted in a rhythmic loss and reappearance of C3b receptor reactivity. At room temperature (19-22 degrees C) this effect was much less expressed. There was no influence of preincubation at 4 and 37 degrees C, respectively, on the iC3b and C3d receptor reactivity of Raji cells. (4) Diisopropylfluorophosphate (DFP) present during rosette formation enhanced, within a certain range of concentration, the percentage of C3b-dependent rosette formation. iC3b and C3d receptor reactivity was not influenced. A similar reaction pattern was observed with pokeweed mitogen (PWM)-stimulated tonsil lymphocytes. In the concentrations tested, DFP showed no effect on the rosette formation between C3b, iC3b, and C3d cells, respectively, and unstimulated tonsil lymphocytes. The data presented suggest that C3b receptors on Raji cells undergo some special metabolism, possibly controlled by fluid phase or cell-bound proteases. This might be a common property of C3b receptors on blast-like and transformed cells, differing from that of unstimulated small lymphocytes.

Binding Sites, Antibody↗
PubMed1982

Differentiation of C3b receptors on human lymphocytes, phagocytes, erythrocytes and renal glomerulus cells by monoclonal antibodies.

C3b receptor protein was purified form human erythrocytes by 2 M KBr solubilization and affinity chromatography on C3-coated sepharose. This material served as antigen for raising monoclonal antibodies. To investigate the distribution and antigenetic relationship between the receptors for C3b on human erythrocytes, lymphoid and phagocytic cells, as well as kidney cells three monoclonal antibodies were selected which inhibited the binding of EAC14 degrees 23b to complement receptor-bearing cells. This could be shown for human erythrocytes by inhibiting the immune adherence reaction, for tonsil lymphocytes, Raji cells, and guinea-pig spleen cells by inhibition of rosette formation of these cells with EAC14 degrees 23b, and for human renal glomeruli by blocking of the the adherence of EAC14 degrees 23b to kidney sections. In contrast, these monoclonal antibodies were not capable of inhibiting rosette formation of human granulocytes and monocytes with EAC14 degrees 23b. The antibodies only interfered with the rosette formation, of EAC14 degrees 23bi and EAC14 degrees 23d with Raji cells and tonsil lymphocytes-if at all-at high concentrations, whereas the rosette formation of Raji cells and tonsil lymphocytes with EAC14 degrees 23b was influenced by supernatants of the selected clones up to a dilution of 1:10(3) to 1:10(5).

Animals↗
PubMed1981

Role of beta 1H for the binding of C3b-coated particles to human lymphoid and phagocytic cells.

Coating of EAC14oxy23b with highly purified human serum beta 1H globulin (beta 1H) led to acceleration of rosette formation with human peripheral blood lymphocytes (PBL), tonsil lymphocytes, B lymphoblastoid (Raji) cells, granulocytes and monocytes. This reaction was discernible from C3bi-dependent rosette formation. Enhancement of rosette formation of C3b cells by beta 1H was most effective at limiting amounts of C3 per EAC14oxy23b. The beta 1H effect was not due to trace contamination with C3b inactivator. beta 1H-dependent rosette formation with the various lymphoid and phagocytic cells could be suppressed by the F(ab')2 fragment of anti-beta 1H suggesting beta 1H-mediated binding of beta 1H-coated particles to complement receptor-positive (CR+) cells. In turn, binding of fluid-phase beta 1H to lymphoid and phagocytic cells could be demonstrated by fluorescence and by 14C-labeled beta 1H. In addition, the functional status of these cells with respect to their receptor reactivity was altered. Treatment of normal lymphocytes (PBL, tonsil lymphocytes) and of granulocytes with beta 1H improved their rosette formation with both EAC14oxy23b and EAC14oxy23b-beta 1H. The reaction of monocytes was hardly affected. The beta 1H effect on Raji cells resulted in reduced rosette formation with EAC14oxy23b-beta 1H, while binding of EAC14oxy23b remained unchanged. These results suggest the presence of sites on CR+ cells, to which soluble and particle-bound beta 1H can bind, leading to alteration of the functional status of the cells. In all likelihood, EAC14oxy23bi can attach to the beta 1H-binding sites on CR+ cells.

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

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

Adenine and hypoxanthine metabolism in phythohemagglutinin-stimulated and unstimulated human lymphocytes.

The uptake and subsequent metabolism of adenine and hypoxanthine in phytohemagglutinin-stimulated and unstimulated peripheral human blood lymphocytes, freshly prepared or cultured, were studied. To investigate the initial step of nucleic acid metabolism the incorporation of 14C-purines into the acid soluble material was examined. No preferential uptake of adenine or hypoxanthine was observed in freshly prepared and cultured lymphocytes during an incubation of 1 h. However, cultured cells utilized approximately 1/3 of the purines compared to freshly drawn cells. Within the cells 2/3 of adenine and 1/2 of hypoxanthine were metabolized to nucleotides (mainly AMP and ADP). Incubation of lymphocytes with PHA for 1 h produced in the freshly prepared cells an increase of adenine- and hypoxanthine-uptake to 191% and 153%, in 48 h stimulated cells to 158% and 132%. There was, however, no change in the relative rates of the metabolic routes though the intracellular concentrations of nucleotides formed increased with adenine as substrate to 152% and with hypoxanthine to 161% during a 1 h stimulation. In contrast no enhanced formation of acid soluble nucleotide formation could be observed with PHA stimulation during 48 h. The increased rates of purine uptake and metabolism apparent 1 h after addition of mitogen may be due to an altered transport mechanism at the beginning of the transformation as an adaptive response to the increased requirements for the synthetic processes soon to follow. Once the lymphocytes are transformed no demand of purines is necessary and the uptake and metabolism is switched off.

Adenine↗
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↗
PubMed1980

[Aminopenicillin rashes - a multicentric prospective study (author's transl)].

538 patients, admitted to the hospitals participating in this study for a variety of indications for antibacterial therapy, were treated by the ampicillin-analogue Epicillin. 42 patients (7.8%) who developed exanthem underwent detailed clinical and immunological investigation. Exanthems were scored according to the form of application and doses of Epicillin as well as to the morphology and time of onset of the exanthem. A variety of serological tests were performed: 1. total IgE (RIST), 2. presence of penicilloyl-specific IgE (RAST), 3. penicilloyl-reactive antibodies using an antiglobulin-haemagglutination-tests. In addition, PHA-induced lymphocyte transformation was studied in 10 patients with exanthems. 38/42 patients developed transient monomorphic morbiliform or scarlatiniform exanthems. 4. exanthems were classified as urticarial or polymorphic. In contrast to the 38 patients, the latter also were positive in the serological tests as it is observed in patients with IgE-mediated penicillin allergy.

Ampicillin↗