Vaccination against Helicobacter pylori - an old companion of man

Keller, W; Michetti, Pierre

doi:10.1517/14712598.1.5.795

Cited by 6 publications

(4 citation statements)

References 52 publications

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“…Selective antigens with high immunocompetence from H. pylori proteins are therefore needed to reduce side‐effects and increase specificity. Although most studies have focused on urease‐based vaccines in animals and humans due to its unique relevance to H. pylori and immunization with urease has been successful in animal models, 32–35 clinical trials in humans with recombinant urease are unlikely to fully protect against H. pylori challenge 36 . In the present study, affinity‐purified natural H. pylori urease was selected as an antigen for hen immunization and IgY against H. pylori urease (anti‐HpUIgY) was applied as an oral passive immunization for H. pylori .…”

Section: Discussionmentioning

confidence: 99%

Effect of dietary anti‐Helicobacter pylori‐urease immunoglobulin Y on Helicobacter pylori infection

Suzuki

Nomura

Masaoka

et al. 2004

Aliment Pharmacol Ther

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Summary Recently, chicken egg yolk was recognized as an inexpensive antibody source, and the therapeutic usefulness of egg yolk immunoglobulin Y (IgY) in oral passive immunization has been investigated. Although multiple antibiotic treatments eradicate most Helicobacter pylori (H. pylori) infections, therapy fails in 10–15% of cases due to the development of drug resistance. Consequently, it is important that new, more broadly based therapies for the treatment of H. pylori infection should be identified. The present study evaluated the effect, on H. pylori infection, of IgY prepared from egg yolk of hens immunized with H. pylori urease (anti‐HpU IgY). Seventeen asymptomatic volunteers diagnosed as H. pylori‐positive by the 13C‐urea breath test (UBT) were orally administered anti‐HpU IgY for 4 weeks. Four weeks later, UBT values were significantly decreased although no case showed H. pylori eradication. An H. pylori‐positive 53‐year‐old female gastritis patient administered anti‐HpU IgY plus lansoprazole for 8 weeks showed a decrease in serum pepsinogen (PG) I and UBT values as well as an increase in the PG I/II ratio. In conclusion, anti‐HpU IgY may mitigate H. pylori‐associated gastritis and partially attenuate gastric urease activity. Furthermore, anti‐HpU IgY combined with antacids appears to ameliorate gastric inflammation. These encouraging results may represent a novel approach to the management of H. pylori‐associated gastroduodenal disease.

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Section: Discussionmentioning

confidence: 99%

Effect of dietary anti‐Helicobacter pylori‐urease immunoglobulin Y on Helicobacter pylori infection

Suzuki

Nomura

Masaoka

et al. 2004

Aliment Pharmacol Ther

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“…Most studies have focused on urease-based vaccines in animals or humans because of the essentiality of urease. Although immunization with urease has been successful in animal models (Michetti et al ., 1994), clinical trials in humans with recombinant urease are not likely to protect fully against H. pylori challenge (Keller & Michetti, 2001). H. pylori HSP60 has also been studied as a vaccine candidate.…”

Section: Discussionmentioning

confidence: 99%

Identification of immunodominant Helicobacter pylori proteins with reactivity to H. pylori-specific egg-yolk immunoglobulin

Shin

Nam

Kim

et al. 2003

Journal of Medical Microbiology

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The importance of hens eggs as a source of specific antibodies (IgY) is well recognized. The protective effect of IgY obtained from hens immunized with Helicobacter pylori whole-cell lysate has been reported for the control of H. pylori infection. However, IgY produced by whole-cell lysates presents the possibility of cross-reactivity with other bacteria, including the normal human flora, and this could decrease the efficiency of IgY. In the present study, the immunodominant proteins of H. pylori with reactivity to H. pylori-specific IgY (IgY-Hp) were identified. IgY obtained from hens immunized with various fractions of H. pylori proteins was isolated and purified, titres of IgY-Hp against H. pylori were determined and cross-reactivity between IgY-Hp and normal human bacteria was examined by Western blot analysis. Finally, immunodominant H. pylori proteins were identified by LC/MS analysis. IgY obtained 2 months after immunization with H. pylori whole-cell lysate showed the highest antibody titre. Five immunodominant proteins were identified that were strongly reactive to IgY-Hp: urease â-subunit (62 kDa), heat-shock protein 60 (60 kDa), urease AE-subunit (26 kDa), probable peroxiredoxin (22 kDa) and probable thiol peroxidase (18 kDa). Immunization of hens with the immunodominant proteins identified would produce a more specific IgY against H. pylori.

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“…Thus, even in the absence of complete eradication, therapeutic vaccination may already be beneficial, as it reduces the numbers of bacteria exposed to antibiotics and thus decreases the possibility of inducing antibiotic-resistant H. pylori organisms. Although one should be aware of the limitations of animal models with regard to therapeutics, preliminary human vaccine trials have already been performed and further results are awaited (294,310,327,425,668).…”

Section: Vaccinationmentioning

confidence: 99%

Pathogenesis ofHelicobacter pyloriInfection

2006

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SUMMARY Helicobacter pylori is the first formally recognized bacterial carcinogen and is one of the most successful human pathogens, as over half of the world's population is colonized with this gram-negative bacterium. Unless treated, colonization usually persists lifelong. H. pylori infection represents a key factor in the etiology of various gastrointestinal diseases, ranging from chronic active gastritis without clinical symptoms to peptic ulceration, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. Disease outcome is the result of the complex interplay between the host and the bacterium. Host immune gene polymorphisms and gastric acid secretion largely determine the bacterium's ability to colonize a specific gastric niche. Bacterial virulence factors such as the cytotoxin-associated gene pathogenicity island-encoded protein CagA and the vacuolating cytotoxin VacA aid in this colonization of the gastric mucosa and subsequently seem to modulate the host's immune system. This review focuses on the microbiological, clinical, immunological, and biochemical aspects of the pathogenesis of H. pylori.

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Vaccination against Helicobacter pylori - an old companion of man

Cited by 6 publications

References 52 publications

Effect of dietary anti‐Helicobacter pylori‐urease immunoglobulin Y on Helicobacter pylori infection

Effect of dietary anti‐Helicobacter pylori‐urease immunoglobulin Y on Helicobacter pylori infection

Identification of immunodominant Helicobacter pylori proteins with reactivity to H. pylori-specific egg-yolk immunoglobulin

Pathogenesis ofHelicobacter pyloriInfection

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