Supplementary Figure 6: A schema of immunological events in CHS response.

Sensitization phase. Epidermal contact with antigens triggers release of IL-1 in the skin, which activates macrophages that subsequently attract dDCs to perivascular area via CXCL2 to form clusters. In the absence of antigen-specific effector/memory T cells, DC clustering is a transient event, and hapten-carrying DCs migrate into draining LNs to establish sensitization. (b) Elicitation phase. In the presence of antigen-specific effector/memory T cells, the antigen is recognized efficiently in the DC clusters by antigen-specific effector T cells to form clusters, and inflammation is induced promptly via activation and proliferation of antigen-specific effector T cells.