Post-immunisation gastritis and Helicobacter infection in the mouse: a long term study.
OBJECTIVE
Helicobacter pylori is a major cause of peptic ulcers and gastric cancer. Vaccine development is progressing but there is concern that immunisation may exacerbate Helicobacter induced gastritis: prophylactic immunisation followed by challenge with H felis or H pylori can induce a more severe gastritis in mice than seen with infection alone. The aim of this study was to investigate the relationship between immunity to Helicobacter infection and post-immunisation gastritis.


METHODS
(1) C57BL/6 mice were prophylactically immunised before challenge with either H felis or H pylori. Histopathology and colonisation were assessed one month post-challenge. (2) C57BL/6 mice were prophylactically immunised against H felis infection and gastritis assessed up to 18 months post-challenge.


RESULTS
Prophylactic immunisation induced a reduction in bacterial colonisation following H felis challenge which was associated with increased severity of active gastritis with neutrophil infiltration and atrophy. However, immunised mice challenged with H pylori SS1 had little evidence of pathology. Long term follow up showed that post-immunisation gastritis was evident at three months. However, from six months onwards, although immunised/challenged mice still developed gastritis, there was no significant difference between inflammation in these mice and infected controls. Post-immunisation gastritis was not associated with the serum antibody response. Immunisation prevented the formation of secondary lymphoid aggregates in the gastric tissue.


CONCLUSIONS
The H felis mouse model of post-immunisation gastritis is the most extreme example of this type of pathology. We have shown in this model that post-immunisation gastritis is a transient event which does not produce long term exacerbation of pathology.
Sutton
P
P
School of Microbiology and Immunology, University of New South Wales, Sydney, NSW 2052, Australia. Phil_Sutton@csl.com.au
Danon
S J
SJ
Walker
M
M
Thompson
L J
LJ
Wilson
J
J
Kosaka
T
T
Lee
A
A
D000704:Analysis of Variance; D000818:Animals; D001428:Bacterial Vaccines / Q000009:adverse effects* / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005757:Gastritis, Atrophic / Q000276:immunology* / Q000382:microbiology / Q000473:pathology; D016481:Helicobacter Infections / Q000517:prevention & control*; D016480:Helicobacter pylori / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D020556:Neutrophil Infiltration / Q000502:physiology; D051381:Rats; D016622:Silver Staining; D018709:Statistics, Nonparametric; D016896:Treatment Outcome; D014611:Vaccination / Q000009:adverse effects*
D001428:Bacterial Vaccines