9 INTESTINAL CELL MEDIATED IMMUNITY (CMI) TO GLIADIN IS INDUCED IN MICE BY PARENTERAL IMMUNISATION AND CONCURRENT GRAFT-VERSUS-HOST (GVII) REACTION

Abstract

Mucosal CMI to gliadin is liKely to be implicated in the pathogenesis of coeliac disease. Our aim was to induce mucosal CMI to gliadin by feeding gluten-containing diet (GCD) to mice previously parenterally immunised with this antigen.BALB/c mice from a gluten-free diet (GFD) colony were used. They were given parenterally gliadin in complete Freund's adjuvant, and 3 weeks later they were challenged with GCD for 7 days. In further experiments the effect of concurrent GVH reaction was evaluated in BDF1 mice on a GCD, previously immunised with gliadin. CMI responses in small intestinal mucosa were measured by morphometry (villous and crypt length, crypt cell production rate (CCPR), and intraepithelial lymphocytes (IEL) count).Feeding GCD for a week to mice reared on GFD did not produce any change. Similarly, mice given GCD after having been parenterally immunised with gliadin did not show mucosal CMI. Mice on GCD given both gliadin immunisation and GVH showed a significant increase (p<0.05) in crypt depth, CCPR and IEL count, in comparison to controls given only GVH.These results indicate that systemic immunity to gliadin is not sufficient to induce specific intestinal CMI. Additional factors (enhanced antigen presentation, increased intestinal permeability) are also necessary.