A characteristic feature of human IBD, particularly Crohn's disease, is the presence of activated CD4+ T-cells. Recently we have shown that colonic epithelial cell production of MIP-3, a CD4 T-cell-directed chemokine, is elevated in IBD. However, the functional relevance of MIP-3 production during intestinal inflammation is poorly understood. The aim of this study was to determine whether MIP-3 production is increased during murine TNBS colitis and to examine the effect of anti-MIP-3 neutralizing mAb administration in this model. We found that administration of TNBS significantly increased colonic MIP-3 protein levels in Balb/c mice. Consistent with this, a marked increase in the number of CCR6-bearing lamina propria CD4+ and CD8+ T-cells was also observed in TNBS-treated animals. Treatment of mice with an anti-MIP-3 neutralizing mAb significantly reduced TNBS-mediated increases in colonic weight to length ratio, mucosal ulceration, histologic damage and myeloperoxidase activity. TNBS-mediated increases in the number of CCR6-bearing lamina propria T-cells were also substantially reduced by anti-MIP-3 neutralizing mAb treatment. Taken together, our findings indicate that blockade of MIP-3 bioactivity can significantly reduce TNBS-mediated colonic injury and T-cell recruitment suggesting a role for this chemokine in the pathophysiology of intestinal inflammation.