Trypanosoma evansi: Demonstration of a transferrin receptor derived from expression site-associated genes 6 and 7

In Trypanosoma brucei, uptake of host transferrin is mediated by a heterodi meric, glycosylphosphatidylinositol-anchored receptor derived from the 2 ex pression site-associated genes 6 and 7 (ESAG6 and ESAG7). By using specific antibodies, it is shown here that T. evansi, a trypanosome species transmi tted mechanically by biting flies, also expresses a transferrin receptor co mposed of ESAG6 and ESAG7. The cellular uptake of transferrin in T. evansi is completely inhibited with anti-T. brucei (ESAG6/7 heterodimer) antibodie s. The demonstration of a functional ESAG6/7 transferrin receptor in T. eva nsi supports further its close relationship to T. brucei.