Recovery from TNBS-induced colitis leads to the resistance to recurrent colitis and an increased ratio of FOXP3 to CD3 mRNA

ObjectiveThe aim of our study was to investigate the effects of the recovery from acute colitis on recurrent colitis with 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice. MethodsAcute colitis was induced via an intrarectal injection of TNBS. For recurrent colitis, mice were intrarectally treated with a repeated TNBS 14 days after the first TNBS administration. And another two groups (control and recovery groups) were added to the analysis. Disease activity index (DAI), macroscopic and histological assessments, mRNA expression of interleukin (IL)-1, IL-6, tumor necrosis factor (TNF), IL-10, forkhead box P3 (FOXP3) and the ratio of FOXP3 to CD3 in the colonic tissues were evaluated. ResultsMice developed colitis after treated with TNBS. After the last TNBS administration, DAI in the recurrent colitis group was lower than that in the acute colitis group. In the recurrent colitis group, the mice exhibited longer colon length, reduced histological damage and lower IL-1, IL-6, TNF, IL-10 mRNA expression in the colon compared with the acute colitis group. The ratio of FOXP3 to CD3 mRNA expression in the colon of recurrent colitis was higher than that in the acute colitis. There was a significant negative correlation between the ratio of FOXP3 to CD3 mRNA expression and DAI in the acute and recurrent colitis groups (r=-0.808, P<0.05). ConclusionsMice that recovered from TNBS-induced acute colitis with intestinal epithelial disruption are resistant to recurrent colitis, which is associated with an increased ratio of FOXP3 to CD3 mRNA expression.