Effect of Treatment of Mice with Sera Containing Gamma Interferon on the Course of Infection withSalmonella typhimuriumStrain LT-2

Abstract

Swiss/Webster mice pre-treated with .gamma. interferon preparations and then infected with S. typhimurium showed significantly increased survival compared to mock interferon-treated or control mice. Nude mice similarly pre-treated with .gamma. interferon showed similar increased survival after S. typhimurium infections. When .gamma. interferon treatment was delayed until the commencement of the S. typhimurium infection, no effect on mortality was observed. The increased survival of the .gamma. interferon-treated mice did not appear to be due to increased antibody production, more rapid clearing of bacteria from the circulation or enhanced uptake of bacteria by phagocytic cells of the spleen, liver or lungs. The number of viable bacteria isolated from the spleens and livers of interferon-treated mice was significantly lower over time than in organs of mock interferon-treated or untreated mice, suggesting that .gamma. interferon treatment may result in more efficient killing of bacteria by phagocytic cells.