Regulation of Antigenic Variation by <i>Trypanosoma brucei</i> Telomere Proteins Depends on Their Unique DNA Binding Activities

• Main Authors: Bibo Li, Yanxiang Zhao
• Format: Article
• Language: English
• Published: MDPI AG 2021-07-01
• Series: Pathogens
• Subjects: antigenic variation; <i>Trypanosoma brucei</i>; VSG; telomere; TRF; RAP1
• Online Access: https://www.mdpi.com/2076-0817/10/8/967

<i>Trypanosoma brucei</i> causes human African trypanosomiasis and regularly switches its major surface antigen, Variant Surface Glycoprotein (VSG), to evade the host immune response. Such antigenic variation is a key pathogenesis mechanism that enables <i>T. brucei</i> to establish long-term infections. VSG is expressed exclusively from subtelomere loci in a strictly monoallelic manner, and DNA recombination is an important VSG switching pathway. The integrity of telomere and subtelomere structure, maintained by multiple telomere proteins, is essential for <i>T. brucei</i> viability and for regulating the monoallelic VSG expression and VSG switching. Here we will focus on <i>T. brucei</i> TRF and RAP1, two telomere proteins with unique nucleic acid binding activities, and summarize their functions in telomere integrity and stability, VSG switching, and monoallelic VSG expression. Targeting the unique features of <i>Tb</i>TRF and <i>Tb</i>RAP1′s nucleic acid binding activities to perturb the integrity of telomere structure and disrupt VSG monoallelic expression may serve as potential therapeutic strategy against <i>T. brucei</i>.