IMMUNOHISTOCHEMICAL OBSERVATIONS OF ANTIGEN-PRESENTING CELLS AND FOLLICULAR DENDRITIC CELLS IN THE TONSIL

In the present study, in order to investigate the behavior in the lymp hatic system of phagocytic cells which incorporate potential antigen i n the tensile crypt, the distribution of HRP stained macrophages in th e tonsillar system was observed with regard to changes with time. Furt hermore, in the tonsillar tissue, in order to investigate the relation ship among HRP marked macrophages, follicular dendritic cells and adhe sion molecules, such as ICAM-1, immunological double staining was perf omed. It is open to discussion whether ICAM-1 plays an important role as an adhesive molecule in this migration of macrophages. Immunohistoc hemical double staining method detected a relation between anti-ICAM-1 antibody positive cells and antigen stained macrophages. In the stain ed area between anti-ICAM-1 antibodies and anti-DRC-1 antibodies, posi tive cells were clearly observed to have reticular form, particularly in the mature germinal center. This phenomenon implies that dendritic cells express ICAM-1 on the cell surface to contact other immunorelate d cells and/or substances. In the inter-follicular space, anti-ICAM-1 antibody positive cells were observed to form a cluster composed of IC AM-1 positive cells, lymphcytes and HRP stained macrophages. This clus ter may be considered the most primary stage of follicles or as trigge ring the creation of an inmature follicle.