Helicobacter pyloriflagella: antigenic profile and protective immunity

Abstract

Reproducible induction of sterilizing immunity, essential for an effective Helicobacter pylori vaccine, remains elusive. As motility is essential for gastric colonization by Helicobacter, we evaluated whether a vaccine targeting flagella induces improved protection. Mice immunized with a vaccine enriched for H. pylori flagella sheath proteins exhibited significantly reduced colonization, equivalent to that observed in mice immunized with whole-cell lysate. Two-dimensional profiles indicated that flagella contain proteins not evident in whole-cell lysate. Moreover, comparison of Western blot profiles using whole-cell lysate antisera revealed striking differences in antigenicity.

Vaccinating againstHelicobacter pyloriin the developing world

“…26 Additionally, whereas complete protection has been difficult to achieve in larger animal models, a subunit multivalent vaccine incorporating VacA, CagA, and Neutrophil Activating Protein (NAP) was shown to be protective when administered therapeutically in beagle dogs as measured by immunohistochemical detection of H. pylori in histologic sections. 27 Since a vaccine might require multiple antigens, it is encouraging that almost any H. pylori protein that has been tested so far seems to work as well as any other, including urease subunits, 28 CagA, 29 VacA, 29 catalase, 30 flagellin, 31 heat shock proteins, 26 H. pylori adhesion A, 32 NAP, 33 and others. Although whole cell lysate preparations have also been used extensively in mice as described in the initial Helicobacter vaccine reports, 34,35 the development of a human vaccine will require a better characterized, well defined product.…”

Current Status and Prospects for a Helicobacter pylori Vaccine

“…In addition, several laboratories have demonstrated that vaccine-induced protective immunity can be achieved in the absence of antibodies. [36][37][38] A partial list of antigens demonstrated to afford protection against H pylori in mice includes the urease subunits, 24 CagA, 23 VacA, 23 catalase, 39 flagellin, 40 heat shock proteins, 41 H pylori adhesion A, 42 and neutrophil activating protein (NAP). 43 Killed whole-cell bacteria may also suffice, as whole-cell lysates have been used extensively in mice as described in the original Helicobacter vaccine reports.…”

Whos Winning the War? Molecular Mechanisms of Antibiotic Resistance in Helicobacter pylori

“…Arguably the best option would be the production of a H. pylori vaccine, and several possible vaccine candidates are being researched [144–146]. Vaccine components vary and include killed H. pylori whole cell extracts [147], heat shock proteins [148], flagellar antigens [144], adhesion antigens [149], lipopolysaccharide antigens [150], neutrophil activating protein [151], and urease [152].…”

“…Vaccine components vary and include killed H. pylori whole cell extracts [147], heat shock proteins [148], flagellar antigens [144], adhesion antigens [149], lipopolysaccharide antigens [150], neutrophil activating protein [151], and urease [152]. Unfortunately many of these are a long way from human trials [144–146], and the inactivated whole cell extract were proven ineffective in a human volunteer study [153]. …”