FIGURE 1.

Basic characteristics of mature dendritic cells enriched in immunoregulatory molecules (mregDCs) in the tumour immune microenvironment. mregDCs are found in a wide range of tumours and tissues and are highly conserved among species. There are four distinct features of this population—(1) maturation: mregDCs express numerous maturation‐related signature genes, such as lysosomal‐associated membrane protein 3 (LAMP3), CD40, CD86, CD80 and CD83. (2) Migration: they highly express CC chemokine receptor 7 (CCR7), fascin actin‐bundling protein 1 (FSCN1) and intercellular adhenson molecule 1 (ICAM1). (3) Chemokine and cytokine release capability: these cells highly express chemokine ligands such as CC chemokine ligand 17 (CCL17), CCL19 and CCL22, which contribute to recruiting other immune cells expressing CCR4, CCR7 and CXCR3. (4) Significant immunomodulatory function: mregDCs show high expression of immune checkpoint‐related molecules and immunosuppressive genes including programmed death ligand 1 (PD‐L1), PD‐L2, CD200, T‐cell immunoglobulin and mucin‐containing molecule 3 (TIM‐3) and IDO1, which limit T‐cell activation. These features serve as the foundation for subsequent research on mregDCs, offering novel concepts and justifications for DC‐based cell therapy as well as new therapeutic options for tumours based on altering the immune microenvironment. Created with BioRender.com.