Generation of Helicobacter pylori ghosts by PhiX protein E-mediated inactivation and their evaluation as vaccine candidates.
Bacterial ghosts are empty cell envelopes, which may be generated by the controlled expression of the PhiX174 lysis gene E in gram-negative bacteria to obtain vaccine candidates. We describe here the application of this technology to Helicobacter pylori. The lysis gene cassette was cloned into an Escherichia coli-Helicobacter pylori shuttle vector and introduced into an H. pylori recipient strain by bacterial conjugation. Temperature induction of the lysis gene cassette revealed a quantitative killing of the H. pylori culture without induction of lysis-resistant bacteria. Biochemical and transmission electron microscopic studies identified structurally intact H. pylori. Prophylactic oral vaccination experiments using these H. pylori ghosts in the BALB/c mouse model showed a significant reduction of the bacterial load in the ghost group, as measured by a quantitative bacterial reisolation procedure. Ten of 10 and 5 of 10 mice were protected, respectively, without the use of a mucosal adjuvant. Coadministration of ghosts with cholera toxin as mucosal adjuvant resulted in a complete protection of 10 of 10 and 8 of 8 mice against H. pylori challenge, with three animals showing a sterile immunity.
Panthel
Klaus
K
Max von Pettenkofer Institute for Hygiene and Medical Microbiology, LMU Munich, Germany.
Jechlinger
Wolfgang
W
Matis
Alexander
A
Rohde
Manfred
M
Szostak
Michael
M
Lubitz
Werner
W
Haas
Rainer
R
D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology; D001428:Bacterial Vaccines / Q000276:immunology*; D001433:Bacteriolysis; D010584:Bacteriophage phi X 174 / Q000378:metabolism; D002462:Cell Membrane / Q000276:immunology* / Q000502:physiology; D003227:Conjugation, Genetic; D004926:Escherichia coli / Q000235:genetics / Q000821:virology; D005260:Female; D016481:Helicobacter Infections / Q000276:immunology / Q000517:prevention & control*; D016480:Helicobacter pylori / Q000276:immunology* / Q000472:pathogenicity / Q000502:physiology; D007114:Immunization; D051379:Mice; D008807:Mice, Inbred BALB C; D010957:Plasmids / Q000235:genetics; D014169:Transformation, Bacterial; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism
D000942:Antigens, Bacterial; D001428:Bacterial Vaccines; C029555:E protein, bacteriophage X174; D014764:Viral Proteins