Influence of Leukotrienes A4 and B4 on the Immunoglobulin Isotype Selection of Normal and Glucocorticoid-Treated Peripheral Blood Mononuclear Cells.

We demonstrate that LTA4 (10-100 ng/ml) and LTB4 (10-100 ng/ml) influence the B cell differentiation and isotype switch to a different degree. In contrast to LTB4, LTA4 selectively enhanced the IgG synthesis of B cells and PBMC in the range between 30 and 110% (n = 6, p <0.005).

Analysis of Biological Functions of a 60-kD IgE-Binding Component Derived from Sera of Patients with Atopic Dermatitis.

CD23 and its soluble components (sCD23) play an important role in IgE regulation. Sera of patients with atopic dermatitis (AD) were reported to contain an IgE-binding component with a molecular weight of 60 kD. The aim of our study was to analyze the biological functions of the 60-kD component.

Analysis of IgE-binding factors (sCD23) within newborn sera.

Factors are discussed as potential diagnostic parameters of atopic disorders. The amounts of sCD23 in sera from newborn children (n = 4,329) were determined by radioimmunoassay with monoclonal antibodies specific for CD23. The sCD23 levels ranged between 0 and 81.

Isolation and characterization of a 60-kDa IgE-binding component derived from sera of atopic patients (atopic dermatitis).

The low-affinity receptor for IgE (Fc epsilon RII, CD23) and the related soluble IgE-binding factors (IgE-BF; sCD23) play an important role in IgE regulation. Sera of patients suffering from atopic dermatitis (AD) were reported to contain an IgE-binding component with a molecular weight of 60 kD. The aim of our studies was the isolation and characterization of the 60 kD component.

Characterization of allergenic components of rye and wheat flour (Secale, Triticum vulgaris) by western blot with sera of bakers: their effects on CD23 expression.

The allergenic components of water-soluble rye flour extract were studied by immunoblotting. Sera from 100 bakers were analyzed for their IgG, IgG4 and IgE binding pattern. Two allergens with molecular weights of 35 and 14 kD were detected.

Correlation of sCD23 release and immunoglobulin (E, A, G, M) synthesis by peripheral blood lymphocytes of atopic patients.

Peripheral blood lymphocytes of atopic patients were analyzed with regard to spontaneous as well as mitogen-induced CD23 expression, sCD23 release as well as Ig (M, G, A, E) synthesis in vitro. The data were correlated with the results for phenotypically defined peripheral cells (T cells, B cells, monocytes), sCD23 release and amounts of Ig (M, G, A, E). A positive correlation was obtained for serum sCD23 and serum IgE of patients with high and intermediate IgE levels, of sCD23 with the percentage of B cells and sCD23 with serum IgA levels.

Cell-cell interactions for CD23 expression and soluble CD23 release from peripheral lymphocytes of atopic donors.

The cell-cell interactions for CD23 expression and soluble (s)CD23 release from peripheral blood lymphocytes (PBL), as well as purified cells (B, T cells, monocytes) of atopic donors, were studied. Cells either stimulated combined and subsequently separated or stimulated after separation were analysed. IL-4, IL-2, phytohaemagglutinin (PHA), interferon-gamma (IFN-gamma) and the combined interaction of IL-4 and IFN-gamma as well as PHA and IFN-gamma were used as stimuli.

Effect of cytokines on spontaneous and allergen-induced CD23 expression, sCD23 release and Ig(E,G) synthesis from peripheral blood lymphocytes.

We studied the expression of the CD23 antigen as well as the release of soluble CD23 from peripheral blood lymphocytes (PBL) of atopic donors. PBL were stimulated with allergen (Dermatophagoides pteronyssinus; Der.p.

Expression of low-affinity receptor for IgE (Fc epsilon RII, CD23) and IgE-BF (soluble CD23) release by lymphoblastoid B-cell line RPMI-8866 and human peripheral lymphocytes of normal and atopic donors.

The low-affinity receptor for IgE (CD23) as well as the soluble IgE-binding factors (IgE-BF, sCD23) are important factors in IgE antibody regulation. The CD23 expression and the concomitant release of CD23 were analysed from the lymphoblastoid B-cell line RPMI-8866 and from peripheral blood lymphocytes (PBL) of healthy volunteers as well as atopic patients. CD23 expression and sCD23 release of RPMI-8866 cells were dependent on the stage of culture.

Influence of IL-2 and IL-4 on the IgE synthesis and the IgE-binding factor (sCD23) production by human lymphocytes in vitro.

The influence of IL-2 and IL-4 on the mitogen-induced immunoglobulin E and IgG production in vitro was analysed. Furthermore the expression of Fc epsilon RII (CD23 antigen), as well as the release of its soluble products, the isotype-specific IgE binding factors (IgE-BF), was determined. Recombinant IL-2 (rIL-2) exerted opposite effects on the synthesis of IgE by human lymphocytes that were stimulated either by pokeweed mitogen (PWM) or Staphylococcus aureus Cowan I (SAC).

Detection and characterization of IgE-binding factors (IgE-BF) within supernatants of the cell line RPMI-8866, normal human sera and sera from atopic patients.

IgE-binding factors (IgE-BF) have been shown to be important regulatory factors for IgE induction and suppression. The analysis of IgE-binding factor activity by a modified inhibition radioimmunoassay (RIA), as well as by monoclonal antibodies (mAb) was carried out in the supernatant of the Fc epsilon RII+ cell line RPMI-8866 as well as in human sera. Kinetics of IgE-BF showed optimal release from RPMI-8866 cells after 3-4 days.

Cellular requirements of IgE-antibody regulation.

The low affinity receptor for IgE (Fc epsilon RII), which is identical to CD 23 has been recently implicated in a variety of functions. It appears as an early stage specific marker in the ontogeny of the IgM-bearing B cell. In humans the CD 23 is also exposed on T-cells in patients with elevated IgE, while in rodents Fc epsilon RII seems to be mainly present on T-lymphocytes.

Cellular requirements of IgE-antibody regulation.

Regulation of IgE antibody response is T-cell dependent. It has been suggested that IL-4 (BSF-1) induces the expression of Fc epsilon RII on B-lymphocytes. Soluble molecules of the FC epsilon RII with various molecular weights represent IgE-binding factors which according to the current opinion either enhance or suppress the IgE-antibody response.