Epithelial cell lines produce the cytokines IL-1alpha, IL-6 and IL-8 w
hen stimulated with Escherichia coli. The cytokine response is enhance
d by P fimbriae. The epithelial cell lines also respond to stimulation
with other cytokines. These in vitro findings were confirmed in vivo
in patients with E. coli infection who secreted IL-6 and IL-8 into the
urine. The observations suggest that epithelial cells play a more act
ive role in the mucosal immune response than previously recognized.