Researchers have identified how a hormone called SCG2 interacts with the LILRB4 receptor on immune cells to help cancer evade the body’s natural defenses. The study reveals that when SCG2 binds to LILRB4 on myeloid cells, it triggers a signaling cascade that turns these tumor-fighting immune cells into tumor-supporting ones and prevents them from recruiting cancer-fighting T cells.
The research team discovered this interaction through genome-wide screening after previously identifying LILRB4 as an inhibitory receptor. In mouse experiments, cancer cells producing SCG2 grew rapidly as tumors, but treatment with antibodies blocking LILRB4 or removal of SCG2 significantly slowed cancer growth.
These findings could lead to new immunotherapy approaches, as current treatments like checkpoint inhibitors are only effective for 20-30% of cancer patients. The researchers suggest that disrupting the SCG2-LILRB4 interaction could offer new cancer treatment options, while conversely, delivering extra SCG2 might help treat autoimmune or inflammatory disorders by suppressing overactive immune responses.