Allergie und Immunologie最新文献

Pretreatment of mice by the immunostimulator bestatin resulted after four days in a significant enhancement of the phagocytic activity of peritoneal cells. For quantification of the phagocytic process of murine peritoneal phagocytes a new in vivo assay is proposed. Fluorescein isothiocyanate (FITC)-labeled Escherichia coli bacteria were i.p. injected. After ten minutes peritoneal cells were harvested and the phagocytic index of peritoneal phagocytes was fluorescence-photometrically assessed. The frequency distribution of phagocytized bacteria per cell found by the this assay corresponded to Poisson distribution. This coincidence allowed estimation of the minimum number of cells needed for detecting a significant difference of phagocytosis indices, resulting in an enhancement of test efficiency.

In 353 sera (from healthy donors as well as patients suffering from rheumatoid arthritis, systemic lupus erythematosus, hepatitis, malignant melanoma) circulating immune complexes were determined by C1q-binding test and a C1q solid-phase ELISA. Using peroxidase-labelled antibodies (from rabbit) against human mu-, gamma-, and alpha-heavy chains, the immunoglobulin classes in the complexes were determined. In rheumatoid arthritis, immune complexes contain IgM more frequently (41.5%) than in systemic lupus erythematosus (10%). Immune complexes containing only IgA as immunoglobulin were found in 24 cases. Our results including binding experiments with chemically aggregated IgA suggest, that the binding of C1q to IgA is not necessarily followed by classical complement activation.

The new murine monoclonal antibody BL-(H5) reacts with a novel surface molecule which is mainly expressed on human NK and B cells. The antigen is not expressed on peripheral T lymphocytes, thymocytes and different human T-cell lines. BL-(H5) does not bind to erythrocytes and platelets. The monoclonal antibody reacts in western blotting experiments with an antigen of 78kDa.

The possibility to use the colorimetric MTT assay for measuring proliferation and cell death of human peripheral blood lymphocytes (PBL) was studied. In a range from 100,000-800,000 cells/well a linear correlation between the optical signal (OD signal at 570 nm) and the cell number was found. It is necessary to incubate the cells with the MTT at least 2 hours. After stimulation by different PHA concentrations a very good correlation between [3H] thymidine incorporation and MTT assay was found. A comparison of daunomycin cytotoxicity, measurement by trypan blue exclusion and MTT assay, gave also a good correlation between both methods. It can be pronounced that the MTT assay is a suitable method to measure cell proliferation and cell death of human PBL. The assay is easy to handle, a large number of probes can be assayed in a relatively short time and no radioactivity is necessary. For the measurement of the colored product a common ELISA reader can be used.

To evaluate the B cell lineage system in newborns we estimated IL-4 (BCGF/BSF-1) production by lymphocytes isolated from the cord blood and its influence on antibody synthesis. Undertaken experiments were performed in two groups of newborns: stressed newborns mainly with perinatal infection and full-term healthy neonates, comparing to peripheral blood of adults as control. Results revealed 1) the significantly higher percentage of mature B cells (B1) in cord blood of stressed newborns, 2) the significantly higher IL-4 production comparing to full-term neonates, 3) diminished IgG and IgA synthesis in vitro by allogenic activated B cell blasts in the presence of supernatants from cultures of PHA-stimulated lymphocytes isolated from cord blood of stressed newborns. Induction of IgM synthesis by these active supernatants was significantly higher in stressed newborns than in the other examined groups. We suggest that immunoregulatory mechanisms, which control the production of IL-6 (BCDF/BSF-2) are still not completely mature at birth.

Different epitopes of CD68 antigen are detectable by three new generated monoclonal antibodies (MABs) BL-M68/1-3 (all mouse IgM). The MAB BL-M68/3 reacts with an epitope, which is stable also in formalin-fixed paraffin-embedded tissues. In immunohistochemical blocking experiments using the own biotinylated MABs and six CD68 MABs from the IV. Workshop on Human Leucocyte Differentiation Antigens two new epitopes could be defined. The number of known CD68 epitopes increases at least up to seven.

Serum samples of human patients with immediate type allergy were examined for both IgE (by radioallergosorbent test) and IgG (by enzyme immunoassay) antibodies to several of the common inhalant and food allergens. The results show a statistically significant correlation between the titers of anti-allergen antibodies of both isotypes. The data indicate that immune stimulation in atopic individuals is not restricted to the IgE isotype, but equally affects the IgG-producing antibody systems. The statistical relationship observed may either be due to common pathways in the production of both antibody classes in atopic people, or may be explained by preferential binding of allergens to circulating IgE-IgG immune complexes.

Since a few years activity of mitochondrial dehydrogenases has been determined by MTT-test as alternative method to measurement of the cellular activity and proliferation by incorporation of tritiated thymidine. In this test the tetrazolium salt MTT is converted into blue, insoluble formazan dye crystals, which have to be dissolved by a suitable extraction mixture. The present paper describes a modified extraction method using an isopropanol-dimethylformamide mixture acidified to pH 5.5. The modified method enables an optimal, easy to handle, less time and work consuming MTT-assay. A MTT concentration of 1 mg/ml was found to be optimal. The extinction maximum was identified at 566 nm.

Resulting from the knowledge that cyanobacteria (blue-green algae) are able to produce pharmacologically active substances the aqueous extracts from several cyanobacteria species and strains (Microcystis aeruginosa, Synechocystis aquatilis, Oscillatoria redekei, Anabaena flos-aque, Aphanizomenon flos-aquae, Oscillatoria rubescens, Oscillatoria tenuis) were tested for their immunomodulating activity. Extracts from Oscillatoria redekei 051, Oscillatoria tenuis 01 and Synechocystis aquatilis 428 caused an immunosuppression. They inhibited not only the incorporation of 3H-thymidine into mitogen stimulated lymphocytes but reduced also the number of plaque-forming cells of mice as shown by hemolysis-plaque-assay. Only extracts from Oscillatoria redekei 051 did not show any cytotoxic effects in lymphocyte cytotoxic test. This may be an evidence for a specific action on the proliferation of lymphocytes.