Heat shock protein complex vaccination induces protection againstHelicobacter pyloriwithout exogenous adjuvant

• Published in: Vaccine 2014-04, Vol.32 (20), p.2350
• Main Authors: Chionh, Yok Teng, Arulmuruganar, Arthi, Venditti, Elena, Ng, Garrett Z, Han, Jia-Xi, Entwisle, Claire, Ang, Ching-Seng, Colaco, Camilo A, McNulty, Shaun, Sutton, Philip
• Format: Article
• Language: English
• Subjects: Biological activity; Heat shock proteins; Immunization; Infections; Pathogens; Peptides; Product development; Scholarships & fellowships; Ulcers; Vaccines
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/j.vaccine.2014.02.051

Background The development of a vaccine against the human gastric pathogenHelicobacter pylori, the main causative agent of gastric adenocarcinoma, has been hampered by a number of issues, including the lack of a mucosal adjuvant for use in humans. Heat shock proteins (Hsp), highly conserved molecules expressed by both bacteria and mammalian species, possess a range of functions, including acting as chaperones for cellular proteins and the ability to activate innate immune receptors. Hsp complex (HspC) vaccines, containing Hsp derived from pathogenic bacteria, are immunostimulatory without addition of an exogenous adjuvant and can induce immunity against their chaperoned proteins. In this study we explored in mice the potential utility of aH. pyloriHspC vaccine. Results Vaccination withH. pyloriHspC, by either the subcutaneous or respiratory mucosal route, induced a strong antibody response, elevated gastric cytokine levels and significant protection against subsequent live challenge with this pathogen. The level of protection induced by non-adjuvanted HspC vaccine was equivalent to that which resulted from vaccination with adjuvanted vaccines. While protection induced by immunisation with adjuvanted vaccines was associated with the development of a moderate to severe atrophic gastritis, that induced byH. pyloriHspC only resulted in a mild inflammatory response, despite an increase in pro-inflammatory gastric cytokines. This reduced gastritis correlated with an increase in IL-10 and IL-13 levels in the gastric tissues of HspC vaccinated,H. pylorichallenged mice. Conclusions H. pyloriHspC vaccines have the potential to overcome some of the issues preventing the development of a human vaccine against this pathogen: HspC induced protective immunity againstH. pyloriwithout addition of an adjuvant and without the induction of a severe inflammatory response. However, complete protection was not obtained so further optimisation of this technology is needed if a human vaccine is to become a reality.