CD47 is a potent “don’t eat me” signal that enables cancer cells to evade immune surveillance and killing by innate immune cells, such as macrophages.
By using bispecific antibodies with a high affinity targeting arm (against a tumor-associated antigen, or TAA) and an anti CD47 arm of an optimized low affinity, the don’t eat me signal is blocked selectively on TAA-positive cells, leading to the effective engulfment and degradation of tumor cells by macrophages (right-hand part of the video).
Due to the absence of a tumor-specific targeting arm, a monovalent anti CD47 bsAb is unable to bind and block CD47, with tumor cells that can resist the attach of macrophages.
Images were taken with Nanolive’s 3D Cell Explorer at a rate of one image every 30 seconds.
