Roles of Zinc Signaling in the Immune System

Figure 4

A decrease in intracellular-free Zn is critical for LPS-mediated CD4⁺ T-cell activation by DCs. LPS, a TLR4 ligand, induces DC activation, which initiates a maturation signal mediated by MyD88 and TRIF. TRIF-mediated signaling reduces the expression of ZIPs (blue) and increases that of ZnTs (red), resulting in a net decrease in the intracellular-free Zn level in DCs. This reduction of intracellular-free Zn is critical for the antigen presentation via MHC-II molecules and the subsequent activation of antigen-specific CD4⁺ T cells.