Fig. 1

TAMs mediate immune cell regulation in TME. Tumor-associated macrophages (TAMs) intricately modulate the anti-tumor immune response within the tumor immune microenvironment through subtle interactions with distinct immune cell subsets. TAMs activate immune checkpoints, downregulate antigen presentation, and secrete regulatory factors to coordinate CD8 + T-cell responses. Additionally, TAMs suppress dendritic cell antigen presentation and infiltration. TAMs secrete TGF-β and CSF-1 can promote the amplification of MDSCs. Concurrently, TAMs recruit immune-suppressive Treg cells and inhibit the functions of NKT cells, leading to suppressive effects. By interacting with tumor-associated neutrophils, TAMs further facilitate tumor cell growth. Moreover, TAMs regulate NK cell activation and inhibition through distinct phenotypes. The diagram illustrates certain molecular mechanisms by which TAMs mediate immune cell regulation