Booth Id:
MCRO014
Category:
Microbiology
Year:
2021
Finalist Names:
Zhao, Mingjiu (School: Shanghai Foreign Language School Affiliated to SISU)
Abstract:
In order to explore how the immune response caused by Salmonella Typhimurium plays a role in tumor bacteriotherapy, lipopolysaccharide (LPS) was extracted from Salmonella Typhimurium and another serovar of Salmonella enterica that were cultivated both aerobically and anaerobically. To begin with, it is shown that the activity of LPS from anaerobically-cultivated Salmonella is generally higher than that from aerobically-cultivated one, with activity of the LPS from anaerobically-cultivated S. Typhimurium being 3 to 4 times higher than the other Salmonella LPS, which suggests that the tumor anaerobic microenvironment may have a significant effect on the activity of Salmonella LPS. Furthermore, it is discovered that Salmonella LPS could generally promote TLR 3,4,7 gene expression in normal cells, TLR9 gene expression in cancer cells, and suppress TLR3,4 gene expression in cancer cells, among which the influence of LPS from anaerobically-cultivated S. Typhimurium is more significant. Combining these results with past researches, it is proposed that these influences can help stimulate immune responses to attack tumor while also suppress the tumor development, and the higher activity and the strong inducing effects on TLR genes of LPS from anaerobically cultivated S. Typhimurium is also consistent with its proven effect of curing tumor. In conclusion, the results are consistent with past researches that S. Typhimurium is one of the most possible microorganisms that can be used for large scale clinical treatment of tumor, which suggests that LPS may play an important role in tumor bacteriotherapy by influencing the gene expression of TLR family, which is worth intensive study.