The Protein Expression Level of a Heterogeneous Gene Inserted in LIPI-1 of the Listeria ivanovii Genome Relies on Its Insertion Orientation

In this study, we inserted theM. tuberculosisantigen geneRv0129cinto LI strains at the same site as the genome but with a different insertion orientation. RT-qPCR and Western blot showed that when the insertion orientation of the heterogeneous gene was opposite to theLIorfXYZgene in the Listeriapathogenicity island 1 in the bacterial genome, the heterogeneous gene could be transcribed well but the protein expression level seemed limited, both in vitro and in vivo. When inserted at an orientation consistent withLIorfXYZ at the same site in the genome, the expected 43-kD protein was observed in vitro as well as in a mouse model. Bacterial virulence was found to have decreased after recombination. This work confirms that the protein expression level of the heterogenous gene in such genome-recombinant LI-based vaccines is related to its inserted orientation in the bacterial genome, and a foreign gene inserted at this position of LIPI-1 will abolishListeria virulence without affecting its growth.J Mol Microbiol Biotechnol 2017;27:269-276
Source: Journal of Molecular Microbiology and Biotechnology - Category: Microbiology Source Type: research