One of the immune system’s jobs is to identify cancer cells in advance and kill them. This essential patrol duty is called immune surveillance[21] .
During immune surveillance, a particular subdivision of immune cells called antigen-presenting cells find potentially harmful cells, destroy them, and use proteins from the destroyed cells to activate other immune cells that can mount a final blow, usually T lymphocytes.
Unfortunately, this mechanism is not entirely effective. Tumor cells have a mechanism that allows them to evade immune system activity.
Some tumor cells just do not have the proper signals that could help identify them – therefore, they are simply not “seen ” by the cell guards.
Other cells produce molecules that decrease the efficacy of immune killer cells against cancer. Recently, a group of researchers from Cold Spring Harbor Laboratory[22] has identified the third cancer defense mechanism. This mechanism influences a crucial subset of immune cells – dendritic cells[23] .
These cells mediate between other immune cell types, showing them the potential “enemy ” markers. The researchers have found the following:
In breast cancer tumors with a unique marker called CCR2, tumors grow faster. If the tumor cells lack this marker, the tumor grows significantly slower. If the tumor cells have no CCR2 or this marker is blocked by antibodies, the tumor gets surrounded by several types of immune cells. Immune cells help shrink the tumor. Previously, it was thought that CCR2’s primary function was to guide immune cells to areas with inflammation[24] . The new study found that CCR2 in breast cancer tumors prevents dendritic cells from reaching maturity. If dendritic cells mature correctly, they can attract multiple killer cells toward the tumor. Therefore, blocking CCR2 in tumors can help destroy cancer with the patient’s own immune system. This discovery is a double breakthrough. First, a new important function for CCR2 was discovered. Second, a new potential line of treatment has opened up. However, it would need multiple studies to achieve a harmless CCR2 block, as this molecule is still vital for immunity in normal conditions.
Sources
Reference : [1] – “Cancer cell CCR2 orchestrates suppression of the adaptive immune response | Journal of Experimental Medicine | Rockefeller University Press” . Accessed November 20, 2021. Link .