{'fraction_non_alphanumeric': 0.04472049689440994, 'fraction_numerical': 0.034782608695652174, 'mean_word_length': 4.672535211267606, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Allergens, IgE, mediators, inflammatory mechanisms The relative contribution of IL-4 and IL-13 to human IgE synthesis induced by activated CD4 ÷ or CD8 + T cells

The relative contribution of 1L-4 and IL-13 to the regulation of IgE synthesis has remained relatively poorly characterized, partially because of lack of suitable animal models. We have studied the roles of IL-4 and IL-13 in human IgE synthesis induced by supernatants derived from activated CD4 + or CD8 + T cell clones. Neutralizing anti-IL-4 and anti-IL-13 monoclonal antibodies (mAbs) inhibited IgE synthesis induced by anti-CD40 mAbs and supernatants from CD4 + T cells by an average 61% and 42%, respectively (n = 25). Recombinant IL-13 had additive effects on IL-4-induced IgE synthesis, but only when IL-4 was present at low concentrations. Accordingly, IL-4 was the dominant IgE synthesis-inducing cytokine derived from highly polarized T helper (Tn)2 cells. However, anti-IL-13 mAbs also significantly inhibited IgE synthesis induced by two of three supernatants derived from allergen-specific Tin-like cell lines generated from the skin of patients with atopic dermatitis. Furthermore, antiIL-13 mAbs almost completely inhibited IgE synthesis induced by supernatants from T m cells or CD8 + T cell clones. Taken together, these data indicate that IL-13, in addition to IL-4, contributes to IgE synthesis induced by all T helper cell subsets, including allergen-specific T m cells. Moreover, IL-13 appears to be the major IgE synthesis-inducing cytokine derived from Tin cells or CD8 + T cells. (J Allergy Clin Immunol 1997;100:792-801.)