Skip to main content
NCBI home page
Infection and Immunity logoLink to Infection and Immunity
. 1995 Oct;63(10):4154–4160. doi: 10.1128/iai.63.10.4154-4160.1995

Role of the Helicobacter pylori virulence factors vacuolating cytotoxin, CagA, and urease in a mouse model of disease.

P Ghiara 1, M Marchetti 1, M J Blaser 1, M K Tummuru 1, T L Cover 1, E D Segal 1, L S Tompkins 1, R Rappuoli 1
PMCID: PMC173584  PMID: 7558333

Abstract

The pathogenic role of Helicobacter pylori virulence factors has been studied with a mouse model of gastric disease. BALB/c mice were treated orally with different amounts of sonic extracts of cytotoxic H. pylori strains (NCTC 11637, 60190, 84-183, and 87A300 [CagA+/Tox+]). The pathological effects on histological sections of gastric mucosae were assessed and were compared with the effects of treatments with extracts from noncytotoxic strains (G21 and G50 [CagA-/Tox-]) and from strains that express either CagA alone (D931 [CagA+/Tox-]) or the cytotoxin alone (G104 [CagA-/Tox+]). The treatment with extracts from cytotoxic strains induced various epithelial lesions (vacuolation, erosions, and ulcerations), recruitment of inflammatory cells in the lamina propria, and a marked reduction of the mucin layer. Extracts of noncytotoxic strains induced mucin depletion but no other significant pathology. Crude extracts of strain D931, expressing CagA alone, caused only mild infiltration of inflammatory cells, whereas extracts of strain G104, expressing cytotoxin alone, induced extensive epithelial damage but little inflammatory reaction. Loss of the mucin layer was not associated with a cytotoxic phenotype, since this loss was observed in mice treated with crude extracts of all strains. The pathogenic roles of CagA, cytotoxin, and urease were further assessed by using extracts of mutant strains of H. pylori defective in the expression of each of these virulence factors. The results obtained suggest that (i) urease activity does not play a significant role in inducing the observed gastric damage, (ii) cytotoxin has an important role in the induction of gastric epithelial cell lesions but not in eliciting inflammation, and (iii) other components present in strains which carry the cagA gene, but distinct from CagA itself, are involved in eliciting the inflammatory response.

Full Text

The Full Text of this article is available as a PDF (1.1 MB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Baggiolini M., Dewald B., Moser B. Interleukin-8 and related chemotactic cytokines--CXC and CC chemokines. Adv Immunol. 1994;55:97–179. [PubMed] [Google Scholar]
  2. Blaser M. J. Helicobacter pylori: microbiology of a 'slow' bacterial infection. Trends Microbiol. 1993 Oct;1(7):255–260. doi: 10.1016/0966-842x(93)90047-u. [DOI] [PubMed] [Google Scholar]
  3. Blaser M. J., Parsonnet J. Parasitism by the "slow" bacterium Helicobacter pylori leads to altered gastric homeostasis and neoplasia. J Clin Invest. 1994 Jul;94(1):4–8. doi: 10.1172/JCI117336. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Covacci A., Censini S., Bugnoli M., Petracca R., Burroni D., Macchia G., Massone A., Papini E., Xiang Z., Figura N. Molecular characterization of the 128-kDa immunodominant antigen of Helicobacter pylori associated with cytotoxicity and duodenal ulcer. Proc Natl Acad Sci U S A. 1993 Jun 15;90(12):5791–5795. doi: 10.1073/pnas.90.12.5791. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Cover T. L., Tummuru M. K., Cao P., Thompson S. A., Blaser M. J. Divergence of genetic sequences for the vacuolating cytotoxin among Helicobacter pylori strains. J Biol Chem. 1994 Apr 8;269(14):10566–10573. [PubMed] [Google Scholar]
  6. Crabtree J. E., Covacci A., Farmery S. M., Xiang Z., Tompkins D. S., Perry S., Lindley I. J., Rappuoli R. Helicobacter pylori induced interleukin-8 expression in gastric epithelial cells is associated with CagA positive phenotype. J Clin Pathol. 1995 Jan;48(1):41–45. doi: 10.1136/jcp.48.1.41. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Cussac V., Ferrero R. L., Labigne A. Expression of Helicobacter pylori urease genes in Escherichia coli grown under nitrogen-limiting conditions. J Bacteriol. 1992 Apr;174(8):2466–2473. doi: 10.1128/jb.174.8.2466-2473.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Dubois A., Fiala N., Heman-Ackah L. M., Drazek E. S., Tarnawski A., Fishbein W. N., Perez-Perez G. I., Blaser M. J. Natural gastric infection with Helicobacter pylori in monkeys: a model for spiral bacteria infection in humans. Gastroenterology. 1994 Jun;106(6):1405–1417. doi: 10.1016/0016-5085(94)90392-1. [DOI] [PubMed] [Google Scholar]
  9. Eaton K. A., Morgan D. R., Krakowka S. Campylobacter pylori virulence factors in gnotobiotic piglets. Infect Immun. 1989 Apr;57(4):1119–1125. doi: 10.1128/iai.57.4.1119-1125.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Fiocca R., Villani L., De Giacomo C., Perego M., Trespi E., Solcia E. Morphological evidence of Campylobacter pylori pathogenicity in chronic gastritis and peptic ulcer. Acta Gastroenterol Belg. 1989 May-Aug;52(3-4):324–335. [PubMed] [Google Scholar]
  11. Fox J. G., Correa P., Taylor N. S., Lee A., Otto G., Murphy J. C., Rose R. Helicobacter mustelae-associated gastritis in ferrets. An animal model of Helicobacter pylori gastritis in humans. Gastroenterology. 1990 Aug;99(2):352–361. doi: 10.1016/0016-5085(90)91016-y. [DOI] [PubMed] [Google Scholar]
  12. Genta R. M., Lew G. M., Graham D. Y. Changes in the gastric mucosa following eradication of Helicobacter pylori. Mod Pathol. 1993 May;6(3):281–289. [PubMed] [Google Scholar]
  13. Karita M., Kouchiyama T., Okita K., Nakazawa T. New small animal model for human gastric Helicobacter pylori infection: success in both nude and euthymic mice. Am J Gastroenterol. 1991 Nov;86(11):1596–1603. [PubMed] [Google Scholar]
  14. Lee A., Fox J. G., Otto G., Murphy J. A small animal model of human Helicobacter pylori active chronic gastritis. Gastroenterology. 1990 Nov;99(5):1315–1323. doi: 10.1016/0016-5085(90)91156-z. [DOI] [PubMed] [Google Scholar]
  15. Lee A., Fox J., Hazell S. Pathogenicity of Helicobacter pylori: a perspective. Infect Immun. 1993 May;61(5):1601–1610. doi: 10.1128/iai.61.5.1601-1610.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Mai U. E., Perez-Perez G. I., Allen J. B., Wahl S. M., Blaser M. J., Smith P. D. Surface proteins from Helicobacter pylori exhibit chemotactic activity for human leukocytes and are present in gastric mucosa. J Exp Med. 1992 Feb 1;175(2):517–525. doi: 10.1084/jem.175.2.517. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Marchetti M., Aricò B., Burroni D., Figura N., Rappuoli R., Ghiara P. Development of a mouse model of Helicobacter pylori infection that mimics human disease. Science. 1995 Mar 17;267(5204):1655–1658. doi: 10.1126/science.7886456. [DOI] [PubMed] [Google Scholar]
  18. Murakami M., Saita H., Teramura S., Dekigai H., Asagoe K., Kusaka S., Kita T. Gastric ammonia has a potent ulcerogenic action on the rat stomach. Gastroenterology. 1993 Dec;105(6):1710–1715. doi: 10.1016/0016-5085(93)91067-r. [DOI] [PubMed] [Google Scholar]
  19. Papini E., Bugnoli M., De Bernard M., Figura N., Rappuoli R., Montecucco C. Bafilomycin A1 inhibits Helicobacter pylori-induced vacuolization of HeLa cells. Mol Microbiol. 1993 Jan;7(2):323–327. doi: 10.1111/j.1365-2958.1993.tb01123.x. [DOI] [PubMed] [Google Scholar]
  20. Phadnis S. H., Ilver D., Janzon L., Normark S., Westblom T. U. Pathological significance and molecular characterization of the vacuolating toxin gene of Helicobacter pylori. Infect Immun. 1994 May;62(5):1557–1565. doi: 10.1128/iai.62.5.1557-1565.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Radin M. J., Eaton K. A., Krakowka S., Morgan D. R., Lee A., Otto G., Fox J. Helicobacter pylori gastric infection in gnotobiotic beagle dogs. Infect Immun. 1990 Aug;58(8):2606–2612. doi: 10.1128/iai.58.8.2606-2612.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Ross J. S., Bui H. X., del Rosario A., Sonbati H., George M., Lee C. Y. Helicobacter pylori. Its role in the pathogenesis of peptic ulcer disease in a new animal model. Am J Pathol. 1992 Sep;141(3):721–727. [PMC free article] [PubMed] [Google Scholar]
  23. Schmitt W., Haas R. Genetic analysis of the Helicobacter pylori vacuolating cytotoxin: structural similarities with the IgA protease type of exported protein. Mol Microbiol. 1994 Apr;12(2):307–319. doi: 10.1111/j.1365-2958.1994.tb01019.x. [DOI] [PubMed] [Google Scholar]
  24. Segal E. D., Shon J., Tompkins L. S. Characterization of Helicobacter pylori urease mutants. Infect Immun. 1992 May;60(5):1883–1889. doi: 10.1128/iai.60.5.1883-1889.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Smoot D. T., Mobley H. L., Chippendale G. R., Lewison J. F., Resau J. H. Helicobacter pylori urease activity is toxic to human gastric epithelial cells. Infect Immun. 1990 Jun;58(6):1992–1994. doi: 10.1128/iai.58.6.1992-1994.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Solnick J. V., Tompkins L. S. Helicobacter pylori and gastroduodenal disease: pathogenesis and host-parasite interaction. Infect Agents Dis. 1992 Dec;1(6):294–309. [PubMed] [Google Scholar]
  27. Telford J. L., Covacci A., Ghiara P., Montecucco C., Rappuoli R. Unravelling the pathogenic role of Helicobacter pylori in peptic ulcer: potential new therapies and vaccines. Trends Biotechnol. 1994 Oct;12(10):420–426. doi: 10.1016/0167-7799(94)90031-0. [DOI] [PubMed] [Google Scholar]
  28. Telford J. L., Ghiara P., Dell'Orco M., Comanducci M., Burroni D., Bugnoli M., Tecce M. F., Censini S., Covacci A., Xiang Z. Gene structure of the Helicobacter pylori cytotoxin and evidence of its key role in gastric disease. J Exp Med. 1994 May 1;179(5):1653–1658. doi: 10.1084/jem.179.5.1653. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Tricottet V., Bruneval P., Vire O., Camilleri J. P., Bloch F., Bonte N., Roge J. Campylobacter-like organisms and surface epithelium abnormalities in active, chronic gastritis in humans: an ultrastructural study. Ultrastruct Pathol. 1986;10(2):113–122. doi: 10.3109/01913128609014587. [DOI] [PubMed] [Google Scholar]
  30. Tummuru M. K., Cover T. L., Blaser M. J. Cloning and expression of a high-molecular-mass major antigen of Helicobacter pylori: evidence of linkage to cytotoxin production. Infect Immun. 1993 May;61(5):1799–1809. doi: 10.1128/iai.61.5.1799-1809.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. Tummuru M. K., Cover T. L., Blaser M. J. Mutation of the cytotoxin-associated cagA gene does not affect the vacuolating cytotoxin activity of Helicobacter pylori. Infect Immun. 1994 Jun;62(6):2609–2613. doi: 10.1128/iai.62.6.2609-2613.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Wang Y., Taylor D. E. Chloramphenicol resistance in Campylobacter coli: nucleotide sequence, expression, and cloning vector construction. Gene. 1990 Sep 28;94(1):23–28. doi: 10.1016/0378-1119(90)90463-2. [DOI] [PubMed] [Google Scholar]
  33. Xiang Z., Censini S., Bayeli P. F., Telford J. L., Figura N., Rappuoli R., Covacci A. Analysis of expression of CagA and VacA virulence factors in 43 strains of Helicobacter pylori reveals that clinical isolates can be divided into two major types and that CagA is not necessary for expression of the vacuolating cytotoxin. Infect Immun. 1995 Jan;63(1):94–98. doi: 10.1128/iai.63.1.94-98.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Infection and Immunity are provided here courtesy of American Society for Microbiology (ASM)

RESOURCES