Epigenetic regulation in T. brucei: Changing coats is a chance to survive

Abstract

Trypanosoma brucei is a unicellular protozoan transmitted by Glossina spp. (“tsetse”) flies and the causative agent of Human African trypanosomiasis. This parasite is famous for undergoing antigenic variation, one of the most sophisticated strategies to escape the immune response of its mammalian hosts. Antigenic variation depends on the tight control of the expression of variant surface glycoproteins (VSGs), which form a dense coat that covers the parasite. To perform antigenic variation, T. brucei needs to meet two essential requirements: (1) to express a single VSG gene, among a genetic repertoire of ~2000 members, and (2) to periodically switch the expressed VSG gene. In recent years, several chromatin-associated factors have been found to be important to control VSG gene expression. This chapter focuses on the epigenetic regulation of gene expression in T. brucei, particularly in antigenic variation.