A vaccine against Helicobacter pylori: Towards understanding the mechanism of protection

Aebischer, Toni; Walduck, Anna; Schroeder, Joanna L.; Wehrens, Andrea; Chijioke, Obinna; Schreiber, Soeren; Meyer, Thomas F.

doi:10.1016/j.ijmm.2007.07.009

Cited by 18 publications

(28 citation statements)

References 60 publications

(63 reference statements)

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“…Compared with other papers, this is a low infestation [4,5]. However, this is only the second detection of the bacterium in sand lizards [4] and the third detection of the B. lusitaniae strain in Poland [6,34]. In all lizards, as well in most of the ticks, B. lusitaniae was detected, which confirms the connection of this strain with reptile species [3,35,36].…”

Section: Discussionsupporting

confidence: 64%

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Anaplasmataceae and Borrelia burgdorferi sensu lato in the sand lizard Lacerta agilis and co-infection of these bacteria in hosted Ixodes ricinus ticks

et al. 2011

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BackgroundAnaplasmataceae and Borrelia burgdorferi s.l. are important tick-borne bacteria maintained in nature by transmission between ticks and vertebrate hosts. However, the potential role of lizards as hosts has not been sufficiently studied.ResultsThe current study showed that 23 of 171 examined sand lizards Lacerta agilis were PCR positive for Anaplasmataceae. The nucleotide sequences of the several selected PCR products showed 100% homology with Anaplasma spp. found in Ixodes ricinus collected in Tunisia and Morocco (AY672415 - AY672420). 1.2% of lizard collar scale samples were PCR positive for B. lusitaniae. In addition, 12 of 290 examined I. ricinus were PCR positive for B. burgdorferi s.l. and 82 were PCR positive for Anaplasmatacea. The number of ticks per lizard and the number of ticks PCR positive for both microorganisms per lizard were strongly correlated. Moreover, we found a significant correlation between numbers of ticks infected with Anaplasmataceae and with B. burgdorferi s.l. living on the same lizard. However, there was no significant correlation between detection of both bacteria in the same tick.ConclusionsTo the best of our knowledge, this is the first report of Anaplasmataceae DNA and additionally the second report of B. burgdorferi s.l DNA detection in the sand lizard.

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Section: Discussionsupporting

confidence: 64%

“…are vertebrates and special associations between Borrelia strains and particular groups of vertebrate hosts have been reported [3]. B. lusitaniae was the most common strain detected in lizard species and in ticks feeding on them [4-6]. …”

Section: Introductionmentioning

confidence: 99%

Anaplasmataceae and Borrelia burgdorferi sensu lato in the sand lizard Lacerta agilis and co-infection of these bacteria in hosted Ixodes ricinus ticks

et al. 2011

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“…Second, H. pylori can productively infect bone marrow-derived DCs in vitro (67), and third, DCs in the gastric mucosa of H. pylori-infected individuals can send protrusions into the lumen with which they make direct contacts with H. pylori (67). Even though there is still an ongoing debate as to the exact role of CD4 + T cells during H. pylori infection, these cells are clearly placed at the center of the ensuing immune response (68,69). A current concept stipulates that a strong bias of CD4 + T cells toward a Th1 phenotype is associated with attenuated H. pylori colonization (70,71).…”

Section: Yersinia Enterocolitica Inhibits Ag Presentation By Dcsmentioning

confidence: 99%

Different Bacterial Pathogens, Different Strategies, Yet the Aim Is the Same: Evasion of Intestinal Dendritic Cell Recognition

Bedoui

Kupz

Wijburg

et al. 2010

The Journal of Immunology

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Given the central role of intestinal dendritic cells (DCs) in the regulation of gut immune responses, it is not surprising that several bacterial pathogens have evolved strategies to prevent or bypass recognition by DCs. In this article, we will review recent findings on the interaction between intestinal DCs and prototypical bacterial pathogens, such as Salmonella, Yersinia, or Helicobacter. We will discuss the different approaches with which these pathogens seek to evade DC recognition and subsequent T cell activation. These diverse strategies span to include mounting irrelevant immune responses, inhibition of Ag presentation by DCs, and stretch as far as to manipulate the Th1/Th2 balance of CD4+ T cells in the bacteria’s favor.

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“…This efficacy rate is substantially less than the 495% rate that is deemed acceptable for most other infectious diseases. A prophylactic or therapeutic vaccine would be a cost-effective way to control H. pylori-induced disease.Vaccination is effective in animal models, with 10-to 100-fold reductions (but not sterile immunity) in bacterial colonisation reported in a variety of experimental animals, following immunisation by either oral or parenteral routes (reviewed in [3][4][5]). Oral (mucosal route) vaccination is desirable for a human H. pylori vaccine because of the ease of delivery and, for a live vaccine, the necessity of a single dose is also attractive.…”

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confidence: 99%

Local recall responses in the stomach involving reduced regulation and expanded help mediate vaccine‐induced protection against Helicobacter pylori in mice

Becher¹,

Deutscher²,

Simpfendorfer³

et al. 2010

Eur J Immunol

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Helicobacter pylori is recognised as the chief cause of chronic gastritis, ulcers and gastric cancer in humans. With increased incidence of treatment failure and antibiotic resistance, development of prophylactic or therapeutic vaccination is a desirable alternative. Although the results of vaccination studies in animal models have been promising, studies in human volunteers have revealed problems such as 'post-immunisation gastritis' and comparatively poor responses to vaccine antigens. The focus of this study was to compare the gastric and systemic cellular immune responses induced by recombinant attenuated Salmonella Typhimurium-based vaccination in the C57BL/6 model of H. pylori infection. Analysis of lymphocyte populations in the gastric mucosa, blood, spleen, paragastric LN and MLN revealed that the effects of vaccination were largely confined to the parenchymal stomach rather than lymphoid organs. Vaccine-induced protection was correlated with an augmented local recall response in the gastric mucosa, with increased proportions of CD4 1 T cells, neutrophils and reduced proportions of CD4 1 Treg. CD4 1 T cells isolated from the stomachs of vaccinated mice proliferated ex vivo in response to H. pylori antigen, and secreted Th1 cytokines, particularly IFN-c. This detailed analysis of local gastric immune responses provides insight into the mechanism of vaccine-induced protection.Key words: Helicobacter pylori . Stomach . Treg cells . Vaccine IntroductionHelicobacter pylori is a Gram-negative spiral bacterium that infects the mucous gel layer of the human stomach. Infection is chronic and causes a range of diseases ranging from acute to chronic gastritis, ulcers and, in a small proportion of patients, gastric adenocarcinoma [1].The treatment of H. pylori disease is not straightforward. The most commonly used combination antibiotic therapy, amoxicillin plus clathromycin and a proton pump inhibitor, now only achieve a cure in o80% of cases [2]. This efficacy rate is substantially less than the 495% rate that is deemed acceptable for most other infectious diseases. A prophylactic or therapeutic vaccine would be a cost-effective way to control H. pylori-induced disease.Vaccination is effective in animal models, with 10-to 100-fold reductions (but not sterile immunity) in bacterial colonisation reported in a variety of experimental animals, following immunisation by either oral or parenteral routes (reviewed in [3][4][5]). Oral (mucosal route) vaccination is desirable for a human H. pylori vaccine because of the ease of delivery and, for a live vaccine, the necessity of a single dose is also attractive. 2778with issues such as poor immunogenicity [6], and adverse reactions [7], presenting serious obstacles to further progression of a human vaccine [8]. The reasons for this failure probably result from apparently opposing aspects of the immune response to vaccination. On the one hand vaccination causes 'post-immunisation gastritis' a local inflammatory responses in the stomach in many animal and human recipients, a...

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A vaccine against Helicobacter pylori: Towards understanding the mechanism of protection

Cited by 18 publications

References 60 publications

Anaplasmataceae and Borrelia burgdorferi sensu lato in the sand lizard Lacerta agilis and co-infection of these bacteria in hosted Ixodes ricinus ticks

Anaplasmataceae and Borrelia burgdorferi sensu lato in the sand lizard Lacerta agilis and co-infection of these bacteria in hosted Ixodes ricinus ticks

Different Bacterial Pathogens, Different Strategies, Yet the Aim Is the Same: Evasion of Intestinal Dendritic Cell Recognition

Local recall responses in the stomach involving reduced regulation and expanded help mediate vaccine‐induced protection against Helicobacter pylori in mice

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