T-CELL SUBSETS AND CYTOKINES IN ALLERGIC AND NONALLERGIC CHILDREN .2.ANALYSIS OF IL-5 AND IL-10 MESSENGER-RNA EXPRESSION AND PROTEIN-PRODUCTION

Interleukin 5 (IL-5) has an enhancing effect on IL-4 induced immunoglo bulin E (IgE) synthesis, Furthermore, IL-5 plays an important role in the differentiation, recruitment, activation and survival of eosinophi ls. IL-10 has a downmodulating effect on interferon gamma (IFN-gamma) production and can exert strong anti-inflammatory activities, Therefor e, we analysed whether differences were present in IL-5 and IL-10 mRNA expression and protein production between T cells of children with al lergic and non-allergic asthma, atopic dermatitis and healthy control children, We demonstrated significant increases in IL-5 mRNA expressio n and protein production in different T cell fractions of children wit h allergic and non-allergic asthma and children with atopic dermatitis as compared to healthy controls, This indicates that IL-5 is not only involved in allergy, but also plays a role in the inflammatory proces s of non-allergic asthma, Interestingly, IL-10 mRNA expression by puri fied T cells of children with allergic and non-allergic asthma and chi ldren with atopic dermatitis was strongly decreased as compared with t hat of healthy controls, In the peripheral blood mononuclear cell (PBM C) fraction, IL-10 mRNA expression was comparable between the four gro ups, We hypothesize that this decreased T cell derived IL-10 expressio n results in a lack of immunosuppression of the inflammatory process i n these diseases, However, a role of monocyte derived IL-10 cannot be ruled out. (C) 1997 Academic Press Limited.