Delivery of protein antigens and DNA by virulence-attenuated strains of Salmonella typhimurium and Listeria monocytogenes.
Two different plasmid-vector systems were developed which allow the efficient production and presentation of protein antigens in antigen-presenting cells (APC) by means of virulence-attenuated bacteria. The first antigen-delivery system is based on the secretion machinery of the Escherichia coli hemolysin (HlyA-type I secretion system), which transports proteins, possessing the specific HlyA secretion signal (HlyA(s)) at the C-terminus, across both membranes of gram-negative bacteria. This system functions in all gram-negative bacteria that possess the TolC-analogous protein in the outer membrane. This outer membrane protein is necessary for the stable anchoring of the type I secretion apparatus in the cell envelope. Suitable HlyA(s)-fused antigens are secreted with high efficiency by E. coli and by virulence-attenuated strains of Salmonella, Shigella, Vibrio cholerae and Yersinia enterocolitica. The other vector system expresses the heterologous antigen under the control of an eukaryotic promoter in a similar fashion as in plasmids commonly used for vaccination with naked DNA. This plasmid DNA is introduced into APCs with the help of virulence-attenuated self-destructing Listeria monocytogenes mutants. After synthesis of the heterologous protein, epitopes of the antigen are presented by the APC together with MHC class I molecules. This system functions in macrophages and dendritic cells in vitro and can also be used in a modified form in animal models.
Gentschev
I
I
Lehrstuhl für Mikrobiologie, Theodor-Boveri-Institut für Biowissenschaften, Am Hubland, 97074, Würzburg, Germany. gentsch@biozentrum.uni-wuerzburg.de
Dietrich
G
G
Spreng
S
S
Kolb-Mäurer
A
A
Daniels
J
J
Hess
J
J
Kaufmann
S H
SH
Goebel
W
W
D000942:Antigens, Bacterial / Q000008:administration & dosage*; D004926:Escherichia coli / Q000235:genetics; D006460:Hemolysin Proteins / Q000008:administration & dosage; D008089:Listeria monocytogenes / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D012486:Salmonella typhimurium / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D014613:Vaccines, Attenuated / Q000008:administration & dosage*; D019444:Vaccines, DNA / Q000008:administration & dosage*
D000942:Antigens, Bacterial; D006460:Hemolysin Proteins; D014613:Vaccines, Attenuated; D019444:Vaccines, DNA