Immunohistological identification of B cell differentiation in human tonsillar follicles by using monoclonal antibodies.

Using immunoperoxidase technique and various monoclonal antibodies, B1, B2, OKT9, OKT10 and Leu-7, we investigated B cell differentiation in the tonsillar follicle. Mantle zone was stained with B1 intensely and B2 faintly. In contrast, germinal center was stained with B1, OKT10 and OKT9, and more intensely with B2. In the intermediate part of the germinal center some large cells were stained with OKT10. With OKT9 antibody, most of cells in the lymphoepithelial symbiosis and some large dendritic cells considered to be tangible body macrophages or dendritic reticulum cells in the germinal center were intensely stained. Leu-7 positive cells were localized mainly in the intermediate part of the germinal center. Stages of B cell differentiation in the tonsillar follicle were discussed, considering these results.