The “Trojan Horse” Approach to Tumor Immunotherapy: Targeting the Tumor Microenvironment

Figure 4

Illustration of the ways in which “Trojan Horse” approaches immunotherapy might be effective. Tumors that are destroyed by local therapy (1) deliver tumor antigens into the draining lymph node (2), that is, the tumor acting as its own vaccine. This cross-primes an antitumor T cell response which, when the tumor vasculature is modified to encourage entry into the tumor (3), results in the accumulation of effector T cells in the tumor. Once local suppressive defenses are overcome (4) and a milieu that is conducive to local effector events is established (5), tumor destruction can result.