Type IV secretion systems (T4SSs) are bacterial multiprotein complexes used for a variety of biological functions, including the injection of effectors into host cells by pathogens, or the exchange of genetic material with other bacteria (1). Bartonella henselae, an intracellular human pathogen, uses a T4SS to translocate effector proteins to the host cells. In addition, we have previously shown that B. henselae can also transfer DNA to human cells through its T4SS, conferring T4SS a high biomedical and biotechnological potential for the development of useful tools for in vivo genetic modification (2). The direct application of these T4SSs for DNA transfer into human cells is hindered by the pathogenicity of the host bacterium. In this work, we have rationally designed the heterologous expression of the T4SS VirB/D4 of Bartonella henselae in the nonpathogenic strain E. coli K-12, following the strategy previously reported to reconstitute a Type III secretion system in a non-pathogenic environment (3). To this end, the required genes for the assembly of the T4SS were amplified in three operons and integrated in different chromosomal loci of E. coli under the control of a tac promoter. We have confirmed the expression and assembly of the synthetic T4SS by western blot. Now, we are testing the functionality of the reconstituted T4SS for protein and DNA delivery into human cells

Resumen del trabajo presentado en el 41 Congreso de la Sociedad Española de Bioquímica y Biología Molecular SEBBM, celebrado en Santander (España) del 10 al 13 de septiembre de 2018.