Icos Costimulation in Combination With Ctla-4 Blockade Remodels Tumor-Associated Macrophages Toward an Antitumor Phenotype

Authors

Naveen Sharma
Xiaozhou Fan
Oluwatomisin T Atolagbe
Zhongqi Ge
Kelly N Dao
Padmanee Sharma
James P Allison

Publication Date

4-1-2024

Journal

Journal of Experimental Medicine

Abstract

We have previously demonstrated synergy between ICOS costimulation (IVAX; ICOSL-transduced B16-F10 cellular vaccine) and CTLA-4 blockade in antitumor therapy. In this study, we employed CyTOF and single-cell RNA sequencing and observed significant remodeling of the lymphoid and myeloid compartments in combination therapy. Compared with anti-CTLA-4 monotherapy, the combination therapy enriched Th1 CD4 T cells, effector CD8 T cells, and M1-like antitumor proinflammatory macrophages. These macrophages were critical to the therapeutic efficacy of anti-CTLA-4 combined with IVAX or anti-PD-1. Macrophage depletion with clodronate reduced the tumor-infiltrating effector CD4 and CD8 T cells, impairing their antitumor functions. Furthermore, the recruitment and polarization of M1-like macrophages required IFN-γ. Therefore, in this study, we show that there is a positive feedback loop between intratumoral effector T cells and tumor-associated macrophages (TAMs), in which the IFN-γ produced by the T cells polarizes the TAMs into M1-like phenotype, and the TAMs, in turn, reshape the tumor microenvironment to facilitate T cell infiltration, immune function, and tumor rejection.

Keywords

Humans, CTLA-4 Antigen, Tumor-Associated Macrophages, Neoplasms, CD8-Positive T-Lymphocytes, Phenotype, Tumor Microenvironment, Inducible T-Cell Co-Stimulator Protein

Comments

Supplementary Materials

PMID: 38517331