The Cellular Immune Response Induced By EF-Tu Multiple Protein Complex Of Escherichia Coli

Elongation factor Tu(EF-Tu),one of the most abundant proteins in Escherichia coli, is a guanine nucleotide-binding protein that plays a key role in protein synthesis.It is highly conserved in all bacteria.Recently,it has been reported as a new pathogen-associated molecular pattern(PAMP) molecule in host' immune recogoniton.However,information regarding to how the protein recognized by host cells and the following immune response is not available.With the use of gene clone and antibody preparation methods,gene TufA from Escherichia coli was cloned and its antibody was prepared.On the basis of past work on the EF-Tu multiple proteins complex the protein OmpA,OmpF and EF-Tu were expressed and purified.By using Western blotting and confocal microscopy methods,OmpA,OmpF and EF-Tu were proved that can interact with human monocytic/macrophage cells THP-1 and collocation in the cellular membrane.Furthermore,the experimental results implied that the components of EF-Tu multiple proteins complex—OmpA,OmpF and EF-Tu can activate THP-1 cells and up-regulate the production of IL-1β,IL-8,IL-10,IL-12,TNF-αby ELISA method.Meanwhile,the results of FACS indicated that the EF-Tu multiple proteins complex enhanced the phagocytosis of Escherichia coli by THP-1 cells in the doze dependent way.In summary,EF-Tu multiple proteins complex was reported for the first time as a novel pathogen-associated molecular pattern(PAMP).Furthermore,the way that EF-Tu multiple proteins complex located in the cellular membrane and detail information of its immune response were characterized.Our findings highlight the mechanism of EF-Tu out of the cells and are helpful in an understanding of EFTu-PAMPs...