Distribution of immunoreactive 2',5'-oligoadenylate synthetase in mouse digestive tract.

2',5'-Oligoadenylate synthetase (2-5OAS), an enzyme induced by interferon (IFN), has also been found in various "normal" animals that had not been treated with IFN. The distribution of this enzyme in the digestive tracts of normal healthy mice was studied by western blotting and by an immunohistochemical method using a specific monoclonal antibody. On western blotting, the antibody to 42 kD 2-5OA synthetase reacted with extracts from the stomach and intestines (small and large intestine), but not with extracts from the esophagus. Immunohistochemically, the 42 kD 2-5OAS was localized on the following cells: surface mucous and parietal cells of fundic glands in the stomach; surface epithelial cells in the intestines; and some enteric nervous cells in the esophagus, stomach, and intestines. Treatment with IFN- alpha/beta did not essentially change the distribution of the enzyme in the tissues, although a small amount of the enzyme was detected in the esophagus by western blotting. Expression of the 42 kD 2-5OAS in the digestive tract may be responsible for the prevention of viral infections.