Up-Regulation of Gr1+CD11b+ Population in Spleen of Dextran Sulfate Sodium Administered Mice Works to Repair Colitis

Dextran sulfate sodium (DSS) is commonly used in rodent IBD models to chemically induce acute intestinal inflammation. The acute course of colitis includes colon tissue damages and recovery from wounded tissues. As skin wound repair was delayed by splenectomy, we asked whether splenectomy would induce the delay of colonic wound healing. In splenectomized mice, body weight recovery, disease score and colon length were delayed. Surprisingly we found a great increase of Gr1+CD11b+ cells in spleen and bone marrow of DSS-administered mice. Anti-Gr-1 antibody treatment worsened the DSS- administered colitis. These results indicate that Gr1+CD11b+ cells induced by DSS worked to repair colon wound healing and repair colitis.