Expression of IL-4 and IL-5 mRNA and protein product by CD4+ and CD8+ T cells, eosinophils, and mast cells in bronchial biopsies obtained from atopic and nonatopic (intrinsic) asthmatics.

We recently demonstrated bronchial mucosal expression of IL-4 and IL-5 at the mRNA and protein level in both atopic and nonatopic (intrinsic) asthma. In this report, using double immunohistochemistry (IHC) and in situ hybridization (ISH), we show that 70% of IL-4 and IL-5 mRNA+ signals co-localized to CD3+ T cells, the majority (>70%) of which were CD4+, although CD8+ cells also expressed IL-4 and IL-5 mRNA. The remaining IL-4 and IL-5 mRNA …