Histamine contamination of pokeweed mitogen

In vitro production of IgE and IgG protein by blood mononuclear cells from non-atopic and atopic donors

The production of IgE and IgG protein by human peripheral blood mononuclear cells in culture has been examined. Cells obtained from 18 grass-sensitive donors during the grass pollen season and from 11 atopic dermatitis patients (total serum IgE levels greater than 960 ng/ml), spontaneously produced significant amounts of IgE but not IgG with time. Similar results were obtained using B-cell enriched preparations from both groups. Cells from 16 non-atopic donors had mean levels of pre-formed IgE similar to those of grass pollen-sensitive donors, but there was no increase in culture IgE with time. Treatment of mononuclear cells with pokeweed mitogen did not influence the production of IgE but markedly increased the amount of IgG synthesized by non-atopic and atopic donor cells. Slight, but significant increases in culture IgE, but not IgG, were seen following a 7-day mixed lymphocyte reaction involving both unrelated non-atopic donor cells and the lymphoblastoid B-cell line, Raji. Treatment of cells with 50 HA units of influenza A/Hong Kong/1/68 (H3N2) virus or with 0.02% v/v (240 IU/ml) of a purified beta-interferon preparation did not alter IgE or IgG produced.