049 Spatial relationship between Merkel cell and Langerhans cell in human hair follicles

Y. Narisawa, K.Taira, T. Tanaka, J. Nakafusa. Division of Dermatology, Department of Internal Medicine, Saga Medical School, Saga, Japan

The distributions of Merkel cell and Langerhans cell within human hair follicles have been reported, respectively. Merkel cell and Langerhans cell share some similar characterizations such as the localization of the bulge area, the close association with peripheral nerves and the expression of several neuropeptides. Serial vertical sections and extracted hair follicles obtained from human skin enabled us to investigate the anatomical relationship between Merkel cell and Langerhans cell in two- and three-dimensions. Merkel cell was stained with CK20 or CAM5.2, while Langerhans cell was decorated with CD1a or S-100 protein. We confirmed the preferential localization of Merkel cells and Langerhans cells in normal human hair follicles and analyzed their distribution. Using a double staining technique, two- and three-dimensional observations demonstrated that a small proportion of Merkel cells were closely contacted with Langerhans cells. It was observed that two cells connected directly or approached with each dendrite. These morphological observations may suggest a functional interaction between Merkel cell and Langerhans cell in human hair follicles.