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An Allelotyping PCR for Identifying Salmonella enterica serovars Enteritidis, Hadar, Heidelberg, and Typhimurium
Published on: July 22, 2011
Identification of genes differentially expressed in RAW264.7 cells infected by Salmonella typhimurium using PCR
Kyung Ho Kang1, Jung A Song, Dong-Jun Shin
1Genomic Research Center for Enteropathogenic Bacteria, and Department of Microbiology, Chonnam National University Medical School, Gwangju 501-746, Republic of Korea.
Abstract:
Salmonella typhimurium, causing mouse typhoid, infects hosts such as macrophage cells, and proliferates in intracellular vacuoles causing infected cells to trigger numerous genes to respond against the infection. In this study, we tried to identify such genes in RAW264.7 cells by using the PCR screening method with degenerate primers. Fourteen genes were found to be differentially expressed after a 4 h infection in which the expression of 8 genes increased while expression of the others decreased. Most of the genes were involved in proinflammatory responses such as cytokines production and cell death. The mutation in msbB gene encoding the myristoyl transferase in lipid A of lipopolysaccharide (LPS) resulted in much lower toxicity to the inoculated animals. We compared the expression of the identified genes in wild-type and msbB-mutated S. typhimurium infections and found that Lyzs encoding lysozyme type M was differentially expressed. This gene is quite likely to be related to bacterial survival in the host cells.
Insights
Salmonella typhimurium infection triggers gene expression changes in macrophage cells. Researchers identified fourteen differentially expressed genes, including Lyzs, crucial for bacterial survival.
Area of Science:
- Microbiology
- Immunology
- Molecular Biology
Background:
- Salmonella typhimurium causes mouse typhoid by infecting macrophage cells.
- Bacterial proliferation within host cells triggers a host gene response.
- Identifying these host genes is crucial for understanding infection dynamics.
Purpose of the Study:
- To identify host genes differentially expressed during Salmonella typhimurium infection in RAW264.7 macrophage cells.
- To investigate the role of specific genes in the host response to S. typhimurium.
- To compare gene expression profiles between wild-type and msbB-mutated S. typhimurium infections.
Main Methods:
- Utilized PCR screening with degenerate primers to identify differentially expressed genes.
- Infected RAW264.7 cells with S. typhimurium for 4 hours.
- Compared gene expression in wild-type and msbB-mutated S. typhimurium infections.
Main Results:
- Identified fourteen differentially expressed genes (8 upregulated, 6 downregulated) after 4 hours of infection.
- Many identified genes are involved in proinflammatory responses and cell death pathways.
- Lyzs (lysozyme type M) was found to be differentially expressed, particularly in infections with mutated S. typhimurium.
Conclusions:
- Host gene expression significantly changes during S. typhimurium infection.
- Proinflammatory responses and cell death are key components of the host's defense.
- Lyzs may play a critical role in bacterial survival within host cells, especially in the context of LPS modification.
