Russian experience in screening, analysis, and clinical application of novel interferon inducers.

This review describes a long-standing experience of screening for interferon (IFN) inducers in Russia. IFN inducers represent a special group of potential antiviral compounds. The main requirements for them are (1) high IFN-inducing activity, (2) absence of side effects, (3) wide spectrum of antimicrobial activity, (4) broad therapeutic security and, (5) good solubility in water and biologic liquids. IFN inducers stimulate IFN production in different cells and organs, and that determines the strategy for their application. Amixin (OOO "Lancepharm," Moscow, Russia) induces IFN-alpha/beta production mostly in T cells. Cycloferon (NTFF "Polysan," St. Petersburg, Russia) stimulates B cells and macrophages to produce almost pure IFN-alpha. Double-stranded RNA (dsRNA) and polyphenols of natural origin stimulate IFN production in different populations of immunocytes. Only polymers, such as Larifan (Riga, Latvia), Kagocel ("NIARnedicplus," Moscow, Russia), and Ragosin (N.F. Gamaleya Institute, Moscow, Russia), induce IFN synthesis in muscles, so they may be effective against rabies. Cycloferon, Larifan, and Kagocel, which induce IFN formation in lungs, may be effective against influenza and rhinoviral infections. Cycloferon and Larifan stimulate IFN production in liver and spleen and may be effective against hepatitis B. Oral compounds (Amixin, Kagocel) that stimulate IFN production in intestines may be effective against hepatitis A and enteroviral infections. Low molecular weight inducers (Amixin, Cycloferon, Kagocel) that penetrate the blood-brain barrier may be active against viral encephalitis. At present, clinical trials of IFN inducers are limited, but in the near future, IFN inducers may be used against very different infections and conditions.