Gene expression profile of small intestinal mucosa in dog repeatedly infected with the cestode Echinococcus multilocularis

Previously, we found that the exclusion of adult worm occurred early stage of reinfection in dog repeatedly infected with E. multilocularis. In this study, we compared gene expression profile in small intestinal mucosa between control (normal dogs), first-infection group (dogs infected with E. multilocularis for the first time) and repeated-infection group (dogs repeatedly infected with this parasite 4 times). A total of 1916 genes for first-infection group and a total of 2950 genes for repeated-infection group were found to be up-regulated >2 fold when compared to control group. The data analysis revealed that genes related to tissue repair were largely upregulated in repeated-infection group compared to controls and first-infection group which indicated that hyperfunction of mucosal response occurred in repeatedly infected dogs. Expression of eight genes was quantified in the same RNA samples by real-time PCR. These microarray results may present new horizons for development of mucosal vaccine for the final hosts. Twelve dogs was divided into three groups (n=4) as followed: control (normal dogs), first-infection group (dogs infected with E. multilocularis for the first time) and repeated-infection group (dogs repeatedly infected with this parasite 4 times). For the first-infection group, 100,000 protoscoleces were orally administrated. For the repeated-infection group, 500,000 protoscoleces was administrated at 1st, 2nd and 3rd infection. At the final infection, 100,000 protoscoleces was administrated by identical method. Small intestine from dogs after 6 days infection (early stage of infection) was used for total RNA extraction. In each group, equal amount of purified total RNAs from four dogs were pooled and then used for microarray analysis.