2-5A synthetase expression in mice infected with Trypanosoma cruzi.

This study describes the production and action of interferon in mice infected with Colombian and Y strain T. cruzi. The production of interferon was monitored by an in vitro assay of plasma and extract of spleen, lung and heart for interferon activity. The action of interferon in mice was assessed by measuring an interferon-mediated enzyme activity, 2-5A synthetase. Infected mice (strain Balb/c) were sacrificed at different time intervals, and the level of this enzyme was measured in extracts of spleen, lung and heart. Colombian strain infection induced higher levels of interferon than Y strain under the same conditions; consequently, a greater increase in 2-5A synthetase induction was observed in the former of the two strains. These results suggest that interferon produced by T. cruzi infected mice is active, since a variety of organs respond to its presence by producing elevated levels of 2-5A synthetase.