Development of antibody-forming cells in follicles of lymph nodes of mice after continuous antigenic stimulation.

It was the purpose of the present study to test a hypothesis on the direct differentiation of newly formed memory B cells into antibody-forming cells (AFC) in the follicles of lymph nodes. AFC may develop in follicles when mobile antigen is present at the moment that such memory B cells have completed their differentiation under influence of immune complexes trapped on follicular dendritic cells (FDC). In order to study whether the simultaneous presence of mobile antigen and immobilized immune complexes on FDC alters the normal distribution of AFC in lymph nodes, different immunization protocols with the thymus-dependent antigens trinitrophenylated keyhole limpet haemocyanin (TNP-KLH) and horseradish peroxidase (HRP) were used. Results confirm that, provided that mobile antigen and immobilized immune complexes are present simultaneously, AFC that are normally found in the medulla of the lymph node may also develop in the follicles.