Difference between revisions of "Part:BBa K3989010"

Revision as of 20:44, 16 October 2021

plant immune elicitor flg22 fused with ClyA for OMV display

In this construct, outer membrane-associated protein ClyA (Part:BBa_K811000) is used to display the plant immune elicitor flg22 (Part:BBa_K3286138) to the surface of bacterial outermembrane vesicles (OMVs) to trigger plant immune responses. To make flg22 better recognized by plant immune receptor FLS2, we put mutiple linkers and a 3×FLAG tag between ClyA and flg22 to minimize the steric hindrance.

By doing western blot using anti-FLAG antibody, we proved that ClyA-elicitor fusion proteins indeed exist in OMVs (Figure 1).

Figure 1. ClyA protein with or without elicitor fused exists in outer membrane vesicles of E. coli omp8 strain.

The immunogenicities of engineered OMVs were tested by Seedling Growth Inhibition (SGI) assay (Figure 2 & 3). In SGI assay, lower seedling weight indicates that higher immune response is triggered (due to the trade-off between immunity and growth). Two E. coli strains were used, omp8 (Figure 2) and tolB (Figure 3), which produce high and low immunogenic OMVs, respectively. For both strains, ClyA-flg22 and ClyA-elf18 OMVs seem to trigger stronger immune responses than OMVs containing only ClyA. However, the enhancement effect is more significant for tolB OMVs than omp8 OMVs. The reason might be that natural omp8 OMVs can already trigger strong immune responses, obscuring the additional immune responses triggered by flg22 or elf18.

Figure 2. engineered E. coli omp8 OMVs can trigger stronger immune responses.

Figure 3. engineered E. coli tolB OMVs can trigger stronger immune responses.

Sequence and Features