Antibodies of IgG2 subtype are involved in the immunological inflammatory response of TNBS-induced enteritis in rats.

Conclusive evidence of particular aetiologic factors in human inflammatory bowel diseases (IBDs) has not been obtained. However, there is information to suggest that immunologic mechanisms are involved in the pathogenesis and perpetuation of both ulcerative colitis and Crohn's disease. A TNBS-induced enteritis was developed by immunisation and local challenge of rats with TNBS. This animal model mimicked several features of human Crohn's disease. Because of the immunoglobulin component in human Crohn's disease, investigation of the TNBS-induced immunological response in the animal model was performed. A specific ELISA was developed to assess the humoral part of the TNBS sensitisation in the rat. Investigation of sera obtained from sensitized animals 11 weeks after the start of TNBS immunisation procedure revealed a clear IgG-specific immune response against TNBS. Immunoglobulin subtypes were differentiated by goat anti-rat antibodies and results indicate a specific IgG2 subtype response.