Experiments
1.Part I：Antigen preparing and immunization
We chose three proteins as antigen for immunization as listed and illustrated below.
Results
Conclusions
We successfully expressed and purified three antigen proteins as designed.
2. Part II: Screening of surface proteins
We chose five outer membrane proteins as candidates used in surface display in Escherichia coli, which are listed and illustrated below.
Results
Conclusions
FliC, FliC-Trx, INP C-terminal fusion and INP sandwich fusion can be used in surface display in E.coli. While we found both the FimH 225 and FimH258 are negative result in either expression or IF detection, which means that the FimH might not be suitable in surface display in E.coli. And next we use INP and FliC-Trx as donor protein to fuse with antigens that need to be expressed at outside of E.coli.
3. Part III：Surface display of Antigens
The tree peptides or protein same as part1 were also expressed at the surface of E.coli strains fused with INP and FliC-Trx as illustrated below.
Results
Conclusions
All the proteins were co-expressed with EGFP correctly, and the transformed E.coli strains can be seen in fluorescent microscope.
Part IV: Model and B cells binding experiment
In this part we designed two models to verify our project. The first model is that we incubated E.coli strains expressing 6His tag outside with NTA beads. The other one is the binding experiment of E.coli strains expressing Flag tag outside and Anti-Flag beads. And finally we did a real test of binding ability of E.coli strain that expressing antigen peptide at surface with B cells that secreting the corresponding antibodies.
Results
Conclusions
Finally we show that our smart E.coli can be used in B cells capturing.
