Taming Cancer by Inducing Immunity via E. coli
Presenter: Xu NanfangCai DanfengChen Yufei
First, we need a E.coli that can escape the immune system after infusing into the blood
Protect E.coli fromImmune SystemK1:O16 capsule
Idea from “bactoblood”, UCBerkeley, iGEM2007
polysialic acid is a frequent coating on mammalian cells, the human immune system does not recognize K1 as foreign
Together, these surface modifications allow the bacterium to avoid detection by the immune system and should extend the serum half-life to several hours rather than the less-than-5 minutes observed with rough strains
Both of these gene clusters have been installed into the genome of MC1061 in the course of preparing our chassis strain, MC828U
Amazing O2
First role of O2: to locate the cancer cells
Study shows that where there’s cancer existing, oxygen level is usually significantly lower than other parts of the body.
E. coli is anaerobic
Second role of O2: to act as a signal for the transcription of a series of factors.
a
A
Density-sensing
Oxygen-sensing
A
K1:O16
hydrolysis
inv
Petra Dersch and Ralph R.Isberg: A region of the Yersinia pseudotuberculosis invasinprotein enhances integrin-mediated uptake intomammalian cells and promotes self-association
Suicidal Component
Make sure that E.coli kills oneself after several generations of division
Advantages:
1. Dependent on the immune system of oneself
2. Detect cancer at an early stage
3. Cancer-specific
Problems:
1. The efficiency of eliminating capsules
2. In vivo vs. in vitro