PD-1/PD-L1-checkpoint blockade therapy is generally thought to relieve tumor cell-mediated suppression in the tumor microenvironment but PD-L1 is also expressed on non-tumor macrophages and conventional dendritic cells (cDCs). Here we show in mouse tumor models that tumor-draining lymph nodes (TDLNs) are enriched for tumor-specific PD-1+ T cells which closely associate with PD-L1+ cDCs. TDLN-targeted PD-L1-blockade induces enhanced anti-tumor T cell immunity by seeding the tumor site with progenitor-exhausted T cells, resulting in improved tumor control. Moreover, we show that abundant PD-1/PD-L1-interactions in TDLNs of nonmetastatic melanoma patients, but not those in corresponding tumors, associate with early distant disease recurrence. These findings point at a critical role for PD-L1 expression in TDLNs in governing systemic anti-tumor immunity, identifying high-risk patient groups amendable to adjuvant PD-1/PDL1-blockade therapy.

dx.doi.org/10.1016/j.ccell.2020.09.001, hdl.handle.net/1765/133558
Cancer Cell
Department of Clinical Genetics

Dammeijer, F., van Gulijk, M., Mulder, E.E., Lukkes, M., Klaase, L., van den Bosch, T, … Aerts, J.G.J.V. (2020). The PD-1/PD-L1-Checkpoint Restrains T cell Immunity in Tumor-Draining Lymph Nodes. Cancer Cell, 38(5), 685–700.e8. doi:10.1016/j.ccell.2020.09.001