Although the functional roles of interleukin (IL-)13 in haematopoietic cell
s are well investigated, those in non-haematopoietic cells remain to be add
ressed. IL-13 exerts its actions by binding to the IL-13 receptor (IL-13R)
on target cells, which is composed of IL-13R alpha1 and the IL-4 receptor a
lpha chain (IL-4R alpha), However, there has been no study of localization
of IL-13R in each tissue. To address this question, we generated monoclonal
anti-IL-13R alpha1 antibody, and performed immunohistochemistry using this
antibody and anti-IL-4R alpha antibody. Distribution of these two componen
ts was the same in all examined tissues. Staining was positive in keratinoc
ytes, hair follicles, and sebaceous and sweat glands in skin; in ciliated r
espiratory epithelial cells in nasal tissue; in heart muscle cells; in fove
ola cells, gastric glands, and the smooth muscle layer in stomach; and in h
epatocytes in liver. However, staining was undetectable in brain and bone m
arrow. Fibroblasts and endothelial cells were stained in some tissues. Thes
e results provide clues to elucidate the known pathological roles of IL-13
in atopic dermatitis and allergic rhinitis, as well as its unknown physiolo
gical roles. (C) 2001 Academic Press.