I. Distribution of b cells Blood, lymphoid organs(lymph node, spleen, tonsil etc. )and mucosa. Naive mature b cells exit the bone marrow and migrate into the periphery. If these mature b cells encounter specific antigen, they become activated or tolerized Following activation, Ag-specific b cells differentiate into antibody-forming celIS(afc) or memory b cells in the germinal centre.II. Distribution of B cells • Blood, lymphoid organs (lymph node, spleen, tonsil etc.) and mucosa. • Naive mature B cells exit the bone marrow and migrate into the periphery. If these mature B cells encounter specific antigen, they become activated or tolerized. • Following activation, Ag-specific B cells differentiate into antibody-forming cells (AFC) or memory B cells in the germinal centre