High affinity nanobodies against the Trypanosome brucei VSG are potent trypanolytic agents that block endocytosis. by Stijlemans, B, Caljon, G, Natesan, S, Saerens, D, Conrath, K, Pérez-Morga, D, Skepper, J, Nikolaou, A, Brys, L, Pays, E, Magez, S, Field, M, De Baetselier, P, Muyldermans, S