Institut Curie Collection,
components of tumoral microenvironment
- Access to: Macrophage Cell and MDSC Map
Macrophages are the major immune component of leucocyte infiltration in tumor. The main markers of macrophage are CD11b+, CD68+, LGALS+ and CD163. Anti-tumor polarization of macrophages is related to their ability to recognize and to reject tumor cells by phagocytosis, represent tumor antigens on the cell surface and induce T-cell response. Macrophages produce cytotoxic agents such as Reactive Oxygen Species and Nitrite Oxide, secrete chemokines as CXCL-8, CCL2, CCL3, etc and attract immune cells into the TME. It addition, they express inflammatory cytokines as TNF, IL12, IL1, etc. facilitating local immunity activation. Tumor associated macrophages (TAMs) can also act as pro-tumor agents, expressing tumor stimulating growth factors as PDGF, EGF, VEGF, FGF, producing immunosuppressive molecules as IL10 and TGFB, that induce angiogenesis and matrix remodelling in TME and consequently facilitate metastatic process.
Myeloid-derived suppressor cells (MDSC) represent heterogeneous population of myeloid cells. In general, the role of MDSC in TME is similar toTAMs. Their main markers are CD33+, CD15+ (granulocytic), CD14+ (monocytic), CD34+ and CD11b+. MDSC suppress T-cell response and Natural killers activity via TGFB signaling and arginine depletion from TME. In addition, MDSCs induce EMT and angiogenesis and participates in matrix remodelling via VEGF and MMPs secretion. MDSC mostly show a pro-tumor activity, therefore presence of this cell type in tumor is correlated with poor clinical prognosis.