Trypanosomes and complement: more than one way to die?

African trypanosomes show a remarkable ability to survive as extracellular para-sites in the blood and tissue spaces of an infected mammal. Throughout the infec-tion they are exposed to the molecules and cells of the immune system, including complement. In this opinion piece, we review decades-worth of evidence about how complement affects African trypanosomes. We highlight the discovery of a trypanosome receptor for complement C3 and we critically assess three recent studies which attempt to provide a structural and mechanistic view of how this receptor helps trypanosomes to survive in the presence of complement.