Local expression of cytokine mRNA in spleen and Peyer's patches of rats is involved in resistance against infection with Yersinia enterocolitica.

The immune-response against infection with Yersinia enterocolitica was studied in a rat model which resembles yersiniosis in humans. Lewis, Fischer and Brown Norway rats were inoculated with Y. enterocolitica and the cytokine mRNA expression in spleen and Peyer's patches was determined. In Brown Norway rats the infection was mild and Yersinia enterocolitica was fully cleared. In these rats the highest anti-inflammatory cytokine expression was found probably resulting in a protective host defence against the infection. In both the Lewis and Fischer rats Y. enterocolitica persisted. The anti-inflammatory cytokine expression was less pronounced in these two rat strains. The authors conclude that progression of disease, persistence of infection and development of reactive arthritis, may be related to the local expression of specific cytokines.