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Mouse fibroblast interferon modifies Salmonella typhimurium infection in infant mice
Abstract:
The effect of mouse fibroblast interferon on Salmonella typhimurium infection in infant mice was examined. The lethality to mice that had been given S. typhimurium intragastrically was significantly reduced in a dose-dependent manner when the mice were pretreated with fibroblast interferon. Lower doses of interferon delayed the development of disease. Interferon neutralized with anti-interferon globulin did not influence the lethality of S. typhimurium to mice. In mice treated with interferon there was also a reduced invasiveness of S. typhimurium in intestinal epithelial cells in vivo. It was further demonstrated in an in vitro system that interferon pretreatment of mouse L-929 cells inhibited the invasiveness of the bacteria in a dose-dependent manner. The in vitro inhibition was neutralized with anti-interferon globulin. The results indicate that interferon inhibits Salmonella bacteria from invading cells and establishing an intracellular state of infection. This may represent an important factor in the pathogenesis of disease.
Insights
Mouse fibroblast interferon significantly reduced Salmonella typhimurium lethality in infant mice. This immune modulation also decreased bacterial invasiveness in intestinal cells, suggesting a key role in infection pathogenesis.
Area of Science:
- Immunology
- Microbiology
- Infectious Diseases
Background:
- Salmonella typhimurium is a significant pathogen causing infant mortality.
- Interferons are critical cytokines involved in antiviral and antibacterial responses.
- The role of fibroblast interferon in Salmonella infection requires further elucidation.
Purpose of the Study:
- To investigate the protective effect of mouse fibroblast interferon against Salmonella typhimurium infection in infant mice.
- To determine the impact of interferon on bacterial invasiveness in vivo and in vitro.
- To explore the underlying mechanisms of interferon's action against Salmonella.
Main Methods:
- Infant mice were infected with Salmonella typhimurium and treated with varying doses of mouse fibroblast interferon.
- Lethality and disease progression were monitored.
- Bacterial invasiveness was assessed in vivo (intestinal epithelial cells) and in vitro (L-929 cell cultures).
- Neutralization experiments using anti-interferon globulin were performed.
Main Results:
- Fibroblast interferon significantly reduced Salmonella typhimurium-induced lethality in a dose-dependent manner.
- Lower interferon doses delayed disease onset.
- Interferon treatment decreased bacterial invasiveness in intestinal epithelial cells in vivo.
- In vitro, interferon pretreatment inhibited bacterial invasion of L-929 cells, also in a dose-dependent manner.
- The protective effects were abolished when interferon was neutralized with anti-interferon globulin.
Conclusions:
- Mouse fibroblast interferon confers significant protection against Salmonella typhimurium infection in infant mice.
- Interferon inhibits Salmonella's ability to invade host cells and establish intracellular infections.
- These findings highlight interferon's potential as a therapeutic agent and its importance in Salmonella pathogenesis.