Age-Related Changes of MHC Class II-immunoreactive Dendritic Cells in Rat Brain

ABSTRACT

PURPOSE: Dendritic cells are antigen presenting cells(APC) that express class II major histocompatibility complex gene products on their surface. Recently, it was proved that dendritic cells activate antitumor immunity for intracranial germ cell tumor. The aim of the present study is to investigate the age-related changes of MHC class II-immunoreactive dendritic cells in the rat brain. METHODS: Male rats(Sprague-Dawley) were sacrificed at 1 month, 12 months and 24 months after birth. Brains were removed and sliced in rat brain matrix. Brain slices were cryosectioned coronally at interaural 5.70-6.70 mm. Brain tissue sections were immunohistochemically reacted with monoclonal MHC class II antibody. RESULTS: MHC class II-immunoreactive dendritic cells were observed in choroid plexuses and white matter(corpus callosum, cerebral peduncle and external capsule). The number of MHC class II-immunoreactive dendritic cells was slightly increased with age. As age increases, shapes of MHC class II-immunoreactive dendritic cells became more complex and aggregated together. CONCLUSION: As age increases, MHC class II-immunoreactive dendritic cells in choroid plexuses and white matter of the brain became not only more complex in shape, but also increased in number to improve immunity.