Figure 1.

Three phases of T-cell responses and their possible therapeutically induced modulations. (a) Schematic illustration of the immune response mediated by antigen-specific T cells. Expansion, contraction and memory phases are highlighted. (b–d) Ad hoc alterations of the three phases of the immune response proposed in ref. 7 as possible strategies to counteract immune evasion. Here, (G1) refers to increasing the number of antigen-specific T cells by acting on the expansion phase, (G2) refers to shortening the duration of the contraction phase to limit T-cell death, and (G3) refers to stabilizing as many T cells as possible inside the long-lived memory reservoir.