Relationship of monoclonal antibody (KHRI 3 epitope) to cochlear supporting cell microvilli in the guinea pig.

As reported previously, monoclonal antibodies can be generated that bind against guinea pig cochlear structures. Preliminary immunohistochemical characterization revealed that one of these monoclonal antibodies (KHRI 3) most probably binds against a surface structure of guinea pig cochlear supporting cells. This study was undertaken to further characterize the KHRI 3 epitope in the cochlea. Since KHRI 3 immunolabeling appeared to be punctate and epitope expression was most pronounced in the reticular lamina, we hypothesized that KHRI 3 epitopes are related to microvilli. To prove this hypothesis immunoelectron microscopy was used. Also investigated was how epitope expression is altered in the reticular lamina microvilli following drug or noise-induced changes. When immunocytochemical results were compared to scanning electron microscopy findings, a striking correlation could be seen between changes in KRHI 3 immunolabeling and changes in the distribution of microvilli. These findings support the assumption that KHRI 3 epitopes are related to microvilli of inner ear supporting cells.