Fig. (1) Developing B cells in the bone marrow (BM) rearrange their H and L chain V domains before leaving the BM as naïve IgM/IgD
expressing B cells which travel in the blood to secondary lymphoid tissues. After encountering antigen some B cells can enter the germinal
center where antigen-specific memory B cells and plasma cells are generated. Plasma cells travel through the blood to the BM where they
compete with developing B cells for long term survival. Circulating memory B cells can be antigen-selected again and form second generation
memory B cells and plasma cells. Developing B cell,○, Naïve B cell, , Memory B cells, , Somatically mutated B cell, , Plasmablast,
, and Plasma cell,●.