Abstract: A novel method of treating and preventing viral infection is provided. In particular a method of blocking viral infection facilitated by a serine proteolytic (SP) activity is disclosed, which consists of administering to a subject suffering or about to suffer from viral infection a therapeutically effective amount of a compound having a serine protease inhibitory or serpin activity. Among compounds are ?1-antitrypsin (AAT), peptide derivatives from the carboxyterminal end of AAT, and man-made, synthetic compounds mimicking the action of such compounds. The preferred viral infections include retroviral infection such as human immunodeficiency virus (HIV) infection.

Abstract: A novel method of treating and preventing diseases is provided. In particular, compositions and methods of blocking diseases associated with aberrant levels of nitric oxide and facilitated by a serine proteolytic (SP) activity are disclosed, which consist of administering to a subject a therapeutically effective amount of a compound having a serine protease inhibitory activity. Among effective compounds are &agr;1-antitrypsin and synthetic drugs mimicking some or all of the actions of &agr;1-antitrypsin.