Intracellular distribution of antibody in immunocytes responding to primary challenge with horseradish peroxidase.

A new improved technic was used to follow the development of, and the intracellular antibody distribution in antiperoxidase antibody-forming cells (AFC) of the mouse popliteal lymph nodes responding to primary stimulation with horse-radish peroxidase (HRP). The first AFC were found 6 to 8 days after immunization and were all plasma cells. Antibody was concentrated in the Golgi complexes and in a few cisternae of rough endoplasmic reticulum. Subsequently, an increasing proportion of the AFC were filled with antibody, and with time the numbers of full cells and the intensity with which they stained increased. Kinetic studies of the cell changes in the lymph node medulla suggest that lymphoid cells proliferate, differentiate into plasma cells, and are then recruited as AFC. Furthermore, it was concluded that the changing intracellular distribution of antibody represents the gradual filling of the AFC with specific antibody.