a Activation and migration of helper t cells o Th cells that have been activated to differentiate into effector cellis interact with antigen-stimulated B cells at the edges of lymphoid follicles in the peripheral lymphoid organs.a. Activation and migration of helper T cells  Th cells that have been activated to differentiate into effector cells interact with antigen-stimulated B cells at the edges of lymphoid follicles in the peripheral lymphoid organs