Molecular basis of type II collagen autoimmune disease: observations of arthritis, auricular chondritis and tympanitis in mice.

A type II collagen autoimmune response results in arthritis, auricular chondritis and tympanosclerosis in humans and animals. The purpose of this study is to further define the molecular and pathogenic events involved in these lesions in rodents. Type II collagen fragment CB11-specific monoclonal antibodies induced lesions in joints, ear lobes and tympanic membranes. In immunized mice, the thickness of tympanic membranes increased to two- to fourfold normal size. Electron micrography showed that the arrangement of collagen fibers is irregular in both radial and auricular layers, containing fibroblasts, a homogeneous material resembling low-density cholesterol crystals and cell infiltration. The mice with auricular chondritis had lymphocytes expressing V beta-8 T cell receptor (TCR) in arthritic joints and lymphocytes expressing V beta-6 TCR in ear lobe lesions. A monoclonal antibody specific to the TCR V beta-8 subfamily suppressed the onset of arthritis. Sequence analyses of the V beta structure of TCR involved in the lesions confirm the immunohistologic study.