How dead and dying cells are removed from the body is revealed in a report published online in Nature Immunology this week.
Dying cells become rapidly covered by a serum component called C1q. Although C1q was thought to be involved in their clearance, the mechanism underlying this was unclear. Terry Means and colleagues find that a receptor called SCARF1, which is present on a number of immune cell types, recognizes C1q bound to dying cells leading to their ingestion and disposal by the immune cells. Interfering with SCARF1’s activity in mice causes the accumulation of dead cells followed by damaging inflammation similar to what is seen in human lupus disease.
The authors conclude that dysfunction of this clearance mechanism may therefore underlie various inflammatory diseases and further understanding of this might lead to new therapeutic interventions.