The role of germinal centres in the generation of immunological memory.

Germinal centres are areas of B lymphocytes proliferation that appear in primary lymphoid follicles after immunization. The results summarized here implicate these structures in the establishment of immunological memory for antibody production. It appears that after primary immunization antigen-antibody-complement complexes become trapped on the membrane of specialized dendritic cells in lymphoid follicles, and these complexes provide the stimulus for germinal centre formation. In support of this, immunization with preformed antigen-antibody complexes, rather than with antigen, leads to the earlier appearance of germinal centres and memory cells, and also accelerates the selective triggering of precursors capable of producing high affinity antibodies.