Characteristics of Immune Cells in TME
| Cell type | Cell surface markers | Functions in TME |
| TAM | CD11b+ CD14+ CD31+ CD34+ CD45+ CD68+ CD117− CD133− CD146− CD204+ CD206+ CCR2+ CSF1R+ MHCII+ VEGFR1+ VEGFR2− (human/mouse); F4/80 (mouse); CD23+ CD16+ CXCR4+ (human) | Enhancement of angiogenesis and remodeling; tumor promotion; association with poor prognosis |
| MDSC | CD11b+ CD14+ MHCI+ MHCIIlow (human/mouse); GR1+ CD11b+ (mouse); CD11b+/− CD33+ CD34+ CD68− (human) | Increased in almost all patients/animals with cancer; ability to suppress T cells as defining trait |
| Neutrophil | CD11b+ CD14low CD31+ CD66B+ CXCR2+ (human/mouse); GR1+ VEGFR1+ CXCR1− (mouse); CD15+ CXCR1+ (human) | Enhancement of angiogenesis and metastasis in animal models; increased levels in patients with colon, gastric and lung cancer; association with poor prognosis in bronchoalveolar carcinoma |
| CD4+ T cell | CD3+ CD4+ CD45+ (human/mouse) | T-helper 1 cells: assistance to CD8+ cells in tumor rejection; T-helper 2 cells: polarization of immunity away from antitumor response |
| CD8+ T cell | CD3+ CD8+ CD45+ (human/mouse) | Effector cells of adaptive immune system; specific recognition and destruction of cancer cells through perforin- and granzyme-mediated apoptosis |
| Regulatory T cells | CD4+ CD25+ FOXP3+(human/mouse) | Central role in tumor maintenance via suppression of antitumor immune response; blocking of CD8+ cell activation and NK cell killing; infiltration associated with poor prognosis (14) |
| NK cell | CD11b+ CD27+; CD3− CD16+/− CD56+; CD3− CD335+ NKp46+ (human/mouse) | Effector lymphocytes; toxicity to cancer cells through perforin-granzyme–mediated apoptosis; contribution to immunosurveillance of cancer; low NK-like cytotoxicity in peripheral blood associated with increased risk of cancer |
CCR = C-C chemokine receptor; CSF = colony-stimulating factor; CXCR = C-X-C chemokine receptor; FOXP = forkhead box protein; MHC = major histocompatibility complex; VEGFR = vascular endothelial growth factor.
Adapted with permission of (2).