Age-related Changes of Antigen Presenting Cells in Rat Brain

Jung, Ho Suck; Yoo, Ki Soo; Kim, Hyung Dong

Abstract

Activation of T cells for an immune response requires the participation of antigen presenting cells that express class II major histocompatibility complex gene products on their surface. As far as we know, there is no study on the agerelated changes of ED2 immunoreactive macrophages and MHC class II immunoreactive dendritic cells in the normal rat brain. The aim of the present study is to investigate the age-related changes of dendritic cells and macrophages in rat brain. The distribution and morphology of the macrophages and dendritic cells in the rat brain were studied from the 1 month-, 12 month- and 24 month-old rats by means of immunohistochemical methods using anti-rat MHC class II and anti-rat ED2 monoclonal antibodies. Antigen presenting cells were observed in choroid plexuses and white matter of the rat brain. The numbers of antigen presenting cells gradually increased with age. At all age stages and regions of the rat brain, the numbers of ED2 immunoreactive macrophages was higher than that of MHC class II immunoreactive dendritic cells. According as age increases, shapes of antigen presenting cells became more complex and aggregated together. In conclusion, the above results suggest that the increases of the number and the changes of the morphology in two kinds of the antigen-presenting cells, MHC class II-immunoreactive dendritic cells and ED2-immunoreactive macrophages, with age may influence on effects of cell-mediated immune responses.