ovalbumin and Burkitt-Lymphoma

IgE plays a key role in the pathogenesis of allergic disease. Interleukin (IL) 4 is a potent and critical stimulator of immunoglobulin class switching from IgM to IgE in B cells. IL-4 induces the expression of epsilon germline transcript (epsilonGT), which is critical to initiate IgE production. While searching for molecules that inhibit epsilonGT expression induced by IL-4, we found that polyphenol strictinin, which was isolated from tea leaves, was able to inhibit the IL-4-induced epsilonGT expression in the human B cell line DND39. Strictinin also acted on human peripheral blood mononuclear cells obtained from healthy donors to inhibit IL-4-induced epsilonGT expression. Strictinin demonstrated similar inhibitory activity in peripheral blood mononuclear cells obtained from atopic donors. Interestingly, strictinin decreased ovalbumin-induced IgE production in mice, whereas the production of IgG and IgM was not affected. Furthermore, we found that the IL-4-induced STAT6 tyrosine phosphorylation, which is essential for IL-4-induced epsilonGT expression, was inhibited in DND39 cells upon treatment with strictinin. Taken together, these results suggest that strictinin can inhibit IgE production through the inhibition of IL-4-mediated signaling in B cells.

Topics: Animals; Antibody Formation; B-Lymphocytes; Burkitt Lymphoma; Cells, Cultured; Dermatitis, Atopic; Female; Humans; Immunoglobulin E; Interleukin-4; Mice; Mice, Inbred C57BL; Ovalbumin; Plant Leaves; Tea; Transcription, Genetic; Tumor Cells, Cultured

A technique is described which allows the antibodies of circulating immune complexes to be isolated as their F(ab')2 fragments. The method is based on the precipitation of the complexes by the sequential addition of conglutinin and anti-conglutinin, and the subsequent digestion of these precipitates by pepsin. Using this technique it has been possible to show antibodies to Epstein-Barr (EB) virus antigens in the immune complexes of patients with Burkitt's lymphoma and to microbial antigens in two patients with nephritis. By substituting DNAase for pepsin it has also been possible to show antibodies to DNA-containing nuclear antigens in the serum of patients with systemic lupus erythematosus.

Topics: Antibodies, Viral; Antigen-Antibody Complex; Antigens, Bacterial; Burkitt Lymphoma; Collectins; Fluorescent Antibody Technique; Glomerulonephritis; Herpesvirus 4, Human; Humans; Immunodiffusion; Immunoglobulin Fab Fragments; Lupus Erythematosus, Systemic; Methods; Ovalbumin; Pepsin A; Serum Globulins

An assay for circulating immune complexes is described which uses radiolabelled bovine conglutinin as ligand and polyethylene glycol precipitation as the technique for separating bound ligands. The technique is simple to perform and gives good sensitivity detecting artificial immune complexes. Its use in detecting complexes in systemic lupus erythematosus and Burkitt's lymphoma is described and it is compared with the Clq binding assay also performed with polyethylene glycol. It is suggested that the simultaneous performance of polyethylene glycol assays using radiolabelled Clq and radiolabelled conglutinin may be an advantageous method for screening sera for the presence of immune complexes.

Topics: Animals; Antigen-Antibody Complex; Binding Sites; Burkitt Lymphoma; Cattle; Chemical Precipitation; Complement Fixation Tests; DNA; Edetic Acid; Humans; Iodine Radioisotopes; Lipopolysaccharides; Lupus Erythematosus, Systemic; Ovalbumin; Polyethylene Glycols; Rabbits; Solubility