Student seminar - Study on the function of MDA5 during Salmonella infection in mice
Reporter: Yu Zhang
Supervisor: Guangxun Meng
Title: Study on the function of MDA5 during Salmonella infection in mice
Time: 13:00-14:00, 2nd November, 2023
Venue: Lecture Hall A201
Introduction:
The intestinal immune system plays an important role in host mucosal immunity in response to the invasion of various pathogens. Salmonella is a common intestinal pathogenic bacterium, which can cause local intestinal damage and systemic typhoid symptoms in an infected host. Upon pathogen invasion, host pattern recognition receptors (PRRs) can recognize the pathogen-related molecular patterns (PAMPs), then activate the downstream immune signaling pathway to achieve pathogen elimination. MDA5 is an intracellular PRR responsible for pathogenic nucleic acid recognition. It was originally thought to be able to specifically recognize the special structural RNA of viruses in the process of antiviral infection, and then activate the downstream type I interferon signal, thus initiating the antiviral immune response.Notably, our study found that MDA5 also plays an important role in the host's resistance to Salmonella infection. The deficiency of MDA5 increased the susceptibility of mice to S. typhimurium infection while the levels of IFN are comparable whether MDA5 was absent or not. In addition, we found that the characteristic markers of M cells, which function as the antigen-sampling cells during Salmonella infection, were reduced in the intestine of MDA5 deficient mice, which may be attributed to the reduced expression of spi-B transcription factor. Our study demonstrates the role of MDA5 against Salmonella infection and aims to explore how it participates in and mediates the host immune responses.
