Human decidua: a source of interleukin-1.

These studies were conducted to determine whether human decidua produces interleukin-1 in response to bacterial endotoxin. Explants of human decidua were incubated with and without Escherichia coli endotoxin for 20 hours. When tested for interleukin-1-like activity with the D10.G4.1 T-cell bioassay, supernatants from endotoxin-stimulated decidua contained significantly more interleukin-1 activity than did supernatants from unstimulated decidua. This activity could not be attributed to interleukin-2, as determined in the CTLL/2 assay for interleukin-2. Interleukin-1-like activity was due to interleukin-1, as demonstrated by the blockade of this bioactivity with antibodies against interleukin-1: interleukin-1 alpha and interleukin-1 beta. Antibodies against interleukin-1 alpha blocked the activity in five of six cases. In one instance, the bioactivity could be attributed to a mixture of interleukin-1 alpha and interleukin-1 beta. These data demonstrate that human decidua can produce interleukin-1 in response to bacterial endotoxin.