You are what you eat: immune cells remember their first meal

Dr Iwan Evans from the Department of Infection, Immunity & Cardiovascular Disease has contributed to a paper in collaboration with Will Wood and Paul Martin at the University of Bristol, which has been published in the prestigious journal Cell!

The paper entitled "Corpse Engulfment Generates a Molecular Memory that Primes the Macrophage Inflammatory Response" describes how macrophages (hemocytes) in the developing fruit fly embryo need to eat dying cells in order to become responsive to wounds and be able to detect and phagocytose bacteria in vivo. Exposure to apoptotic cells causes calcium flashes within fly macrophages on engulfment of the dying cells and this in tern activates JNK signalling to drive up levels of a scavenger receptor called Draper within these macrophages. As Draper is required for both inflammatory migration to wounds and clearance of pathogens, macrophages that have never experienced apoptosis (such as macrophages in embryos that lack all apoptosis) fail to respond to wounds or infection properly. This work uncovers novel mechanisms that determine how immune cells develop a memory of their experiences and may become ‘primed’ to respond to subsequent challenges.

Drosophila macrophages within a developing fruit fly embryo

Drosophila macrophages responding to a wound Phagocytosing macrophages in a fruit fly embryo:

YouTube scribble video explaining the paper:

The article can be found here:

Here is the University of Bristol press release: