KERATIN EXPRESSION REVEALS MOSAIC DIFFERENTIATION IN VAGINAL EPITHELIUM

OBJECTIVE: Analyzing the expression of keratins has proved to be valua ble for identifying of pathways of epithelial differentiation. In stra tified epithelia Kl 0 and Kl 3 are representative for either the kerat inizing (epidermal-type) or the nonkeratinizing pathway, STUDY DESIGN: We have investigated keratin expression in ''normal'' vaginal epithel ium from 30 women, applying two-color immunofluorescence with monoclon al antibodies to K10 and K13 on cryostat sections and cell smears. RES ULTS: A differential expression pattern of vaginal cells dependent on their localization within the epithelium was found. In cells of the fi rst suprabasal layers differentiation began and became identifiable by a weak expression of K13. The adjacent layers displayed cells that co ncurrently expressed K10 and K13. In contrast, cells within the superf icial strata expressed exclusively either one of the two keratins. CON CLUSION: Thus vaginal epithelium appears to be mosaic in differentiati on, showing simultaneous expression of keratins K10 and K13, thought t o be representative for distinct routes of differentiation.