The role of microflora in the development of intestinal inflammation: Acute and chronic colitis induced by dextran sulfate in germ-free and conventionally reared immunocompetent and immunodeficient mice

Abstract
One-week dextran sulfate treatment of conventional (CV) immunodeficient (SCID) mice gave rise to acute colitis in the colon mucosa; germ-free (GF) SCID mice did not exhibit any changes in colon morphology. Dextran sulfate application to CV immunocompetent (BALB/c) mice did induce substantial changes in the colon mucosa (grade4); GF BALB/c mice showed mild changes in the colon morphology (grade1) only. GF SCID mice and CV SCID mice died during the second round of dextran sulfate treatment suffering from chronic colitis; GF BALB/c mice exhibited mild crypt distortion while CV BALB/c mice showed a complete loss of the surface epithelium (grade4), accompanied by T and B lymphocyte infiltration.