Cloning and Expression of TLR4-EGFP Fusion Protein in HT-29 Cells and the Visualized Interaction between TLR4 and Enteropathogenic <i>E.coli</i>

The aim of this study was to determine whether the Escherichia coli (EPEC) attached to cells by the TLR4. A fusion between gene encoding fluoresce-enhanced green fluorescent protein (EGFP) and Toll like receptor 4 (TLR4) was constructed and expressed in Escherichia coli . Then the pEGFP-N1-TLR4 fusion expression vector was transfected into HT-29 cells. The green fluoresce was observed at the plasma membrane of HT-29 cells under inverted fluorescent microscopes. In addition, the FITC stained EPEC was also observed adherence to the TLR4 of HT-29 cells.The results indicated that the EPEC adhered to cells by bonding to TLR4 protein. It is the first time that the TLR4 has been explained as an adhesion receptor.