The goal of NEU_China_A this year is to design a biological system aiming to alleviate intestinal inflammatory diseases and prevent potential colorectal cancer. We chose E. coli Nissle 1917 as our chassis, a probiotic that is safe for humans. On the one hand, when it senses an inflammatory signal in the intestine, it releases an anti-inflammatory drug (interleukin-10) to put out the fire in the intestines. On the other hand, it can release myrosinase to convert the glucosinolate contained in cruciferous vegetables into sulforaphane. The sulforaphane can both alleviate inflammation in the intestine and prevent colorectal cancer induced by chronic inflammation.
In the crypt, the goblet cells secrete mucus covering the surface of the intestinal villi and Paneth cells secrete antibacterial peptides to inhibit bacterial invasion. In addition, the basal stem cells continue to proliferate and differentiate to renew the intestinal epithelium.
Peyer’s patch contains a large amount of lymphoid tissues, which is the key to regulating the immune system's response to pathogens, and is tolerant to harmless microorganisms and food. Dendritic cells in the Peyer’s patch can extend dendrites among epithelial cells, collecting antigen and decomposing it, by which to activate the tolerability of lymphoid cells.
Regulatory T cells secrete IL-10 in the lamina propria, inhibit the immune cells of the lamina propria and epithelial layers, preventing vigorous immunoreaction along with unnecessary inflammation. Once the imbalance of homeostasis in the immune system occurs, it can cause intestinal disease. When this condition persists without intervention, it can lead to inflammatory bowel disease.