Low-dose HDACi potentiates anti-tumor activity of macrophages in immunotherapy.

The success of checkpoint immunotherapy has created optimism that cancer may be curable. However, not all patients respond, resistance is common and many patients relapse owing to immune escape. We demonstrate that HDAC inhibition not only decreases the trafficking of myeloid-derived suppressor cells (MDSCs) into tumors but also potentiates tumor-associated macrophages (TAMs) to specify anti-tumoral phenotype and bolster T cells activation within the tumor microenvironment (TME).