Expression of heat shock protein 70 in the cochlea in experimental autoimmune inner ear disease

To explore whether the immune response of the inner ear could induce heat shock protein 70 (hsp70) in the guinea pig cochlea, we established a model of autoimmune inner ear disease (AIED) by systemically immunizing guinea pigs with homologous crude inner ear antigen (CIEAg). The immunized cochleas and normal control cochleas were examined for the expression of hsp70 by immunohistochemical analysis and in situ hybridization. It was found that 10 of 28 ears showed significant increases in hearing thresholds after the animals had been sensitized with CIEAg, and 67.9% of the ears from the immunized animals had modiolar vasculitis. The hsp70-like proteins were basically expressed in the normal cochleas, but dramatically increased expressions of hsp70 (perhaps also including hsp70-like molecules) and its messenger RNA were observed in the cochleas of the AIED models. The results suggest that the immune response of the inner ear induced the expression of hsp70 in the guinea pig cochleas.