Patterns of keratin expression in the murine thymus.

Polyclonal and monoclonal antibodies recognizing different species of keratin molecules were used to characterize the expression of keratins by epithelial cells in the murine thymus. Some of the reagent antibodies used in this study were raised against human keratins and cross-react with murine keratins. Both cortical and medullary thymic epithelial cells were found to contain keratin with apparent molecular weight of 52 KD, which is considered to be associated with simple or stratified epithelium. In addition, medullary epithelial cells were found to contain other species of keratin molecules, ranging in apparent molecular weight from 40 to 67 KD. This latter population of keratins is thought to be associated with stratified and/or keratinizing epithelia.