PD-1 and LAG-3 blockade improve anti-tumor vaccine efficacy.

Concurrent blockade of different checkpoint receptors, notably PD-1 and CTLA-4, elicits greater anti-tumor activity for some tumor types, and the combination of different checkpoint receptor inhibitors is an active area of clinical research. We have previously demonstrated that anti-tumor vaccination, by activating CD8 + T cells, increases the expression of PD-1, CTLA-4, LAG-3 and other inhibitory receptors, and the anti-tumor efficacy of vaccination can be increased with checkpoint blockade. In the current study, we sought to determine whether anti-tumor vaccination might be further improved with combined checkpoint blockade.