Role of interleukin 4 and gamma interferon in the regulation of human IgE synthesis: possible alterations in atopic patients.

The IgE helper function of human T cell clones or their phytohemagglutinin-induced supernatants was positively correlated with their ability to produce or their content in interleukin 4 (IL-4), whereas it was inversely correlated with production of or content in gamma interferon. The addition to B cell cultures of anti-IL-4 antibody abolished not only the IgE synthesis induced by recombinant human IL-4, but also that induced by IL-4-producing T cell clones or their phytohemagglutinin-induced supernatants. A clonal analysis in nonatopic donors and patients with common atopy showed that atopics possess in their peripheral blood significantly higher numbers of T cells able to secrete IL-4 and to provide helper function for IgE.