A.
Mainly mediate defense against infections by extracellular microbes.
B.
Act in stimulating clonal expansion and differentiation of CTL cells.
C.
Interact with B cells and induce B cell activation and differentiation into plasm cell.
D.
Secret IL-4, IL-5, IL-10 and act in antibodies secretion.
E.
Secret IL-2, IL-12 and active macrophage.