Veterinary microbiology
-
Veterinary microbiology · Mar 2017
Orally administered live attenuated Salmonella Typhimurium protects mice against lethal infection with H1N1 influenza virus.
Pre-stimulation of toll-like receptors (TLRs) by agonists has been shown to increase protection against influenza virus infection. In this study, we evaluated the protective response generated against influenza A/Puerto Rico/8/1934 (PR8; H1N1) virus by oral and nasal administration of live attenuated Salmonella enterica serovar Typhimurium, JOL911 strain, in mice. Oral and nasal inoculation of JOL911 significantly increased the mRNA copy number of TLR-2, TLR4 and TLR5, and downstream type I interferon (IFN) molecules, IFN-α and IFN-β, both in peripheral blood mononuclear cells (PBMCs) and in lung tissue. ⋯ The lethal and sub-lethal challenge showed that the generated stimulated innate resistance (StIR) in JOL911 inoculated mice conferred resistance to acute and initial influenza infection but might not be sufficient to prevent the PR8 virus invasion and replication in the lung. Overall, the present study indicates that oral administration of attenuated S. Typhimurium can pre-stimulate multiple TLR pathways in mice to provide immediate early StIR against a lethal H1N1 virus challenge.