Effect of Treatment with Interferon-γ and Concanavalin A on the Course of Infection of Mice with Salmonella typhimurium Strain LT-2

Lymphokines have been shown to affect the resistance of mice to bacterial infections. To explore this effect further, mice were pretreated with 34 units per day for 5 days of a hybridoma supernatant containing primarily interferon-γ activity. Then, the mice were infected with one LD 50 of Salmonella... Full description

Lymphokines have been shown to affect the resistance of mice to bacterial infections. To explore this effect further, mice were pretreated with 34 units per day for 5 days of a hybridoma supernatant containing primarily interferon-γ activity. Then, the mice were infected with one LD 50 of Salmonella typhimurium strain LT-2. The hybridoma supernatant fluid-treated mice were not protected; in fact, they died faster than did mice only infected with S typhimurium . When mice were pretreated under the same regimen with pure murine IFN-γ produced by recombinant DNA technology prior to infection, the mice were protected and 95% survived the infection. The hybridomas had been treated with concanavalin A (ConA) to induce IFN-γ. When mice were directly treated with ConA prior to infection with S. typhimurium , they also died more quickly than untreated controls. These data suggest that IFN-γ pretreatment can protect mice against infection with S. typhimurium , but that ConA pretreatment can counteract that effect.