Targeting Autocrine CCL5-CCR5 Axis Reprograms Immunosuppressive Myeloid Cells and Reinvigorates Antitumor Immunity.

The tumor-promoting potential of CCL5 has been proposed but remains poorly understood. We demonstrate here that an autocrine CCL5-CCR5 axis is a major regulator of immunosuppressive myeloid cells (IMC) of both monocytic and granulocytic lineages. The absence of the autocrine CCL5 abrogated the generation of granulocytic myeloid-derived suppressor cells and tumor-associated macrophages. In parallel, enhanced maturation of intratumoral neutrophils and macrophages occurred in spite of tumor-derived CCL5. The refractory nature of