Figure 1.

Involvement of the XCL1–XCR1 communication axis in the innate and adaptive cytotoxic responses to cross-presented microbial and tumor antigens. Secretion of the chemokine XCL1 by activated NK cells specifically attracts XCR1-expressing DCs capable of antigen cross-presentation. This ensures an effective communication between these cells in the innate phase of the immune response. In the adaptive phase, secretion of XCL1 by activated CD8⁺ T cells optimizes the dialog with antigen cross-presenting DCs and facilitates the differentiation of CD8⁺ T cells to cytotoxic effector cells.