Alteration of a polyclonal to an oligoclonal immune response to cecal aerobic bacterial antigens in TCR alpha mutant mice with inflammatory bowel disease.

Since lumenal bacteria have been postulated to play an important role in the pathogenesis of inflammatory bowel disease (IBD), we investigated the humoral response to cecal aerobic bacterial antigens by Western blot analysis in TCR alpha -/- mice which spontaneously develop IBD. The sera from TCR alpha -/- mice revealed an alteration of the recognition pattern against aerobic bacterial antigens from polyclonal to oligoclonal with age. This alteration was not observed in TCR delta -/- and TCR alpha +/- mice. The alteration of the recognition pattern in TCR alpha -/- mice was associated with production of autoantibodies against tropomyosin and the development of IBD. The unique population of CD4+ TCR alpha -beta + cells in TCR alpha -/- mice may be involved in the recognition of these bacterial antigens and the absence of the alpha chain may result in the alteration of immune response.