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Biomedical subjects

R Grunow

Publications and source records attributed to R Grunow.

At least 73 records · Page 4Linked to original sources
PubMed1986

[Production of human monoclonal antibodies by heterohybridization of human B lymphocytes of the spleen with mouse myeloma cells].

Human lymphocytes were derived from the spleen of a 15-year-old female patient after partial splenectomy. High cell yield and percentage of human B-lymphocytes (over 30%) gave useful conditions for their fusion to mouse myeloma cells (P3 X63/Ag8/653). Fusion efficiency (cultures with growth) was 96%. From 288 initially seeded cultures 176 showed IgM and only one IgG production as determined by enzyme immunoassays. Twenty primary cell lines were cloned with differing results and 17 heterohybridoma cell clones with high IgM production rates could be established for more than 6 months in vitro. The present results show the possibility to produce human monoclonal antibodies in heterohybrids derived from human spleen lymphocytes.

Adolescent↗
PubMed1986

Recombinant interferon-gamma induces interleukin 2 receptors on human peripheral blood monocytes.

The present report describes the inducibility of IL 2 receptors on human peripheral blood monocytes. Although freshly isolated monocytes are IL 2 receptor negative, approximately one-third of the cells react with the anti-Tac antibody within 18 hr of culture. IFN-gamma is found to double both the number of positive cells and the number of binding sites, whereas IL 2 has no influence on the IL 2 receptor expression on monocytes. Anti-Tac precipitates from monocyte lysates several protein bands of similar m.w. to those previously found with activated T and B cells. Finally, IFN-gamma-induced, but not resting, monocytes are found to bind recombinant IL 2. We conclude that IFN-gamma induces peripheral blood monocytes to express IL 2 receptors similar in structure to those found on activated T and B lymphocytes.

Antibodies, Monoclonal↗
PubMed1986

Correlation between the phenotype and the functional capacity of activated T cells in patients with active systemic lupus erythematosus.

Activated T cells in the peripheral blood of patients with systemic lupus erythematosus (SLE) were determined using monoclonal antibodies against activation antigens. Elevated percentages of HLA-DR+ T cells were found in association with active disease. In contrast, we observed an increase in IL-2 receptor-bearing T cells in only six out of 16 patients with active disease. In vitro assays, like spontaneous proliferation, response to IL-2, production of IL-2, and immunoglobulin synthesis have shown that the different patterns of activation antigens are related to different functional stages of T-cell activation. The possible therapeutic consequences are discussed.

Antigens, Surface↗
PubMed1986

[Histamine receptor-bearing lymphocytes. VI. Influence of histamine on the Go-G1 transition of activated lymphocytes].

Histamine (10(-4) M) suppressed the PHA-induced activation of lymphocytes in vitro. This was shown by inhibition of the expression of DR- and 4F2-antigens, of the blast transformation, DNA- and RNA-synthesis, and the formation of thermostable sheep erythrocyte rosettes. Histamine affect these phenomenons only when added to the culture during the first hours. Already 6 hrs after addition of PHA, it exerted no significant suppression. The target of the inhibiting effect of histamine is the G0-G1-transition of the lymphocytes. Cells that already had entered the G1-phase were no more susceptible to histamine.

Animals↗
PubMed1986

Dipeptidyl peptidase IV in human T lymphocytes. An approach to the role of a membrane peptidase in the immune system.

Dipeptidyl peptidase IV (DP IV), an ectoenzyme in the cell membrane of human T lymphocytes, is an important constituent in the process of lymphocyte activation and proliferation. In the presence of specific inhibitors and antibodies against DP IV several in vitro functions of activated lymphocytes were found to be impaired. These include mitogen induced DNA synthesis, immunoglobulin secretion and production of interferon-gamma. The functional importance of DP IV during activation of lymphocytes is underlined by an increase in cellular DP IV activity upon mitogenic stimulation.

B-Lymphocytes↗
PubMed1986

Normal values and membrane markers of theophylline-sensitive and theophylline-resistant human T-lymphocytes.

In 32 healthy adults between 20 and 50 years, the number of theophylline-resistant T-lymphocytes (T-res) was determined to be 51 +/- 4% or 1,161 +/- 326 per microliter, and that of theophylline-sensitive T-lymphocytes (T-sens), 11 +/- 2% or 252 +/- 95.--The decrease in number of rosette-forming cells after incubation with 1 mM theophylline was not caused by reduced vitality (51Cr-release test). The testing of various theophylline concentrations (1, 3, 5, and 10 mM) did not result in a changed count of T-sens. By a variation of the lymphocyte: sheep erythrocyte ratio and of incubation temperature it was found that T-sens possess high-affine and T-res low-affine receptors for sheep erythrocytes. While about 30% of the cells of both subpopulations proved to have Fc-IgM-receptors, among T-sens a significantly higher number of cells carried Fc-IgG-receptors than among T-res (29% vs. 10%).

Adult↗
PubMed1986

[Chemiluminescence, formation of thermostable E-rosettes and DNA synthesis of human mononuclear cells induced by various lectins].

Various plant lectins differentiate in their ability to induce early (chemiluminescence and thermostable rosette formation) and later (DNA synthesis) activation events of human mononuclear cells. Both phytohaemagglutinin and concanavalin A induced a cell activation detectable by the three investigated parameters. Wheat germ agglutinin was characterized as an efficient stimulator in both assays of early events whereas the induction of DNA synthesis measured by [3H]-thymidine incorporation was low. In contrast, pokeweek mitogen did evoke only a weak chemiluminescence signal, but induced a small number of thermostable rosettes and a high [3H]-thymidine incorporation. The results obtained from experiments with mononuclear cells of twelve healthy donors did not show a firm correlation between the investigated three parameters of cell activation.

Adult↗
PubMed1986

[Histamine receptor-bearing lymphocytes. V. Induction of suppressor cells with histamine or concanavalin A].

Immature human T-lymphocytes form rosettes with autologous erythrocytes (A-RFC). Con A induced suppressor cells in fractions of A-RFC. Mature, immunocompetent T-lymphocytes are non-A-RFC. They bear histamine receptors, and in such fractions histamine induced suppressor cells. After activation, both suppressor cells seem to be identical. They bear histamine receptors, Fe-receptors for IgG and the T8-antigen. For the expression of their suppressive effect the presence of monocytes is required.

Animals↗
PubMed1986

[Influence on the immune response of C-reactive protein (CRP)].

The influence of C-reactive protein (CRP) on early and late parameters of mitogen-induced lymphocyte activation in vitro has been tested. Early activation markers (increase of cell size and formation of thermostable SE rosettes) and the lymphocyte proliferation (3H-thymidine incorporation) were changed by CRP (10-50 micrograms/ml), whereas PWM-induced stimulation was inhibited and PHA-induced activation was enhanced. Production of human immunoglobulins in vitro in culture from 12 healthy donors was influenced by CRP in a different manner. Modulation of mitogenic responses of lymphocytes by CRP occurs in an early stage of the cell cycle. Responsible for this phenomenon can be soluble factors, which were removed from the culture by washing the cells after 24 hrs. We discuss here the unspecific modulatory role of CRP in various immune-mediated diseases.

Adult↗
PubMed1986

A sensitive and class specific solid phase enzyme immunoassay for anti-DNA autoantibodies in supernatants of lymphocyte cultures and human hybridomas.

A solid phase enzyme immunoassay using methylated bovine serum albumin (BSA)-precoated and DNA-coated microtiter plates was developed for the detection of IgG and IgM anti-DNA autoantibodies in the supernatants of lymphocyte cultures and hybridomas. In patients with systemic lupus erythematosus (SLE) the significantly raised IgG anti-DNA antibody synthesis indicates that preactivated anti-DNA clones circulate in the peripheral blood. This was associated with the detection of anti-DNA antibodies in the sera. The screening of 53 supernatants from human x mouse hybridomas showed an antibody to denatured DNA in 16 supernatants.

Antibodies, Monoclonal↗
PubMed1986

Pokeweed mitogen induced synthesis of human IgG and IgM in vitro. Technical aspects and the role of adherent cells.

The Pokeweed mitogen (PWM)-inducing in vitro synthesis of human IgG and IgM was determined by enzyme immunoassay (EIA) in culture supernatants of PWM-stimulated peripheral blood lymphocytes (PBL) from 83 healthy donors ranging from 24-46 years. Seventy five per cent were characterized as normal responders (200-2000 ng/ml IgG and IgM), 10% classified as high responders (2000-3000 ng/ml), and another 10% had a very high response (more than 5000 ng/ml of both IgG and IgM). One of 83 donors was shown to be a PWM non-responder. In 83 unstimulated cultures from the same donors 660 +/- 75 ng/ml IgG and 60 +/- 10 ng/ml IgM were measured after 8 days of incubation. Ten donors exhibited similar dose dependence of PWM-induced Ig synthesis but differed in time kinetics (optimum between 8 and 12 days of culture). Regression analysis of IgG and IgM production in 83 PWM-stimulated lymphocyte cultures from different healthy donors showed a correlation coefficient of r = 0.627. Intracellular Ig in PWM-stimulated cells was quantified by EIA technique after cell lysis in time kinetic experiments. Reproducibility and accuracy of the test system are described in detail. An excess of monocytes of more than 20% in the culture caused an inhibition of the Ig synthesis (calculated on constant numbers of B cells). Monocytes were further immobilized in FCS-coated culture plates and pulsed with PWM for 2 h. Adding unstimulated, nonadherent cells to the plates after removing the mitogen resulted in an Ig production comparable to that with the classical method.

Adult↗
PubMed1985

[Diagnostic and therapeutic use of monoclonal antibodies].

During the last years monoclonal antibodies have become an important constituent of the clinical diagnostic systems for the detection of various humoral and cellular antigens. By means of monoclonal antibodies new knowledge could be observed in the typing of leukaemias and in the functional characterization of immune cells. Furthermore, possibilities of therapeutical use of monoclonal antibodies and present problems concerning this matter are discussed. The development of human monoclonal antibodies will be helpful in the solution of some of these problems.

Animals↗
PubMed1985

Decrease of HLA-DR antigen expression by human monocytes during cultivation in absence of exogenous or endogenous interferon-gamma.

The kinetics of HLA-DR antigen expression by human peripheral blood monocytes during cultivation in vitro was studied. Immediately after separation by glass adherence, about 60% of monocytes expressed DR antigens as judged by indirect fluorescence staining with a monoclonal antibody (BL-DR/1). Monocytes carefully depleted of lymphocytes, gradually lost their DR antigens during cultivation in the absence of exogenous interferon-gamma (IFN-gamma). However, addition of a few lymphocytes to the adherent cells prevented the decrease of DR antigen expression. Furthermore, it was shown that doses as low as 1 IU/ml of IFN-gamma are sufficient to induce DR antigen expression by cultured monocytes. Experiments with cyclosporin A suggest that lymphocytes contaminating the monocyte preparations can produce spontaneously sufficient amounts of IFN-gamma for maintenance of the DR antigens on monocytes.

Cells, Cultured↗
PubMed1985

The influence of haematoporphyrin derivative and visible light on murine skin graft survival, epidermal Langerhans cells and stimulation of the allogeneic mixed leucocyte reaction.

The influence of combined photochemical treatment with a haematoporphyrin derivative and visible light on antigen-presenting cells was evaluated. Treatment of murine skin grafts with this procedure prolonged their subsequent survival on allogeneic recipients. The haematoporphyrin derivative and light decreased the ATPase activity of epidermal Langerhans cells in murine skin. When stimulator cells in a human allogeneic mixed leucocyte reaction were treated with the haematoporphyrin derivative and light, they lost their stimulatory capacity. It is proposed that the haematoporphyrin derivative and visible light interfere, on analogy with ultraviolet radiation, with the function of antigen-presenting cells.

Adenosine Triphosphatases↗
PubMed1985

Lectin-induced thermostable SE-rosette (TSER) formation by human peripheral blood lymphocytes.

Lectin-activated human peripheral blood lymphocytes were able to form thermostable rosettes with sheep red blood cells (SRBC). Capability to form thermostable rosettes (TSER) after lectin treatment was comparable in time kinetics and dose dependence to cell size distribution changes. Enhancement of TSER formation by human lymphocytes exposed to PHA and Con A, however, occurred before 3H-Thymidine incorporation could been registered. Lectin treatment of lymphocytes from 20 healthy donors for 48 hrs induced 49 +/- 4% (PHA), 33 +/- 5% (Con A), and 20 +/- 2% (PWM) thermostable rosette forming cells, whereas in unstimulated cultures were found 4 +/- 1%. Furthermore, thermostable rosette forming cells were enriched by gradient centrifugation and characterized as activated lymphocytes of T-origin by SE rosetting and binding studies with various monoclonal antibodies. It was shown that preparation of TSER forming cells after lectin activation makes it possible to enrich the fraction of lectin-stimulated T lymphocytes.

Animals↗
PubMed1985

[Transfer and expression of mutations in pleiotropic genes determining the synthesis of extracellular enzymes in Bacillus subtilis].

The mutations in the genes determining the levels of extracellular enzymes production were transferred into Bacillus subtilis 168 strain by genetic transformation technique. The method used has permitted registering the transfer of pleiotropic genes. Seven amylase producers were detected among 126 his+ transformants screened, as well as five metalprotease producers among 246 gly+ transformants. Cotransfer of pap and hpr mutant genes linked with his+ or gly+ genes might result in finding the producers among the mentioned prototrophic transformants. Selection of linked markers in transformation, presented in the paper, is discussed to be a useful technique for obtaining producer strains for industrial production.

Bacillus subtilis↗