The dynamics of antigenic variation and growth of African trypanosomes.

Antigenic variation in African trypanosomes, which is a simple strategy for survival in the immune host, is rendered complex by its magnitude. For protection from nonspecific immunity and escape from specific immunity, each trypanosome is covered by a replaceable surface coat composed of the variant surface glycoprotein (VSG), which specifies the variable antigen type (VAT) of the trypanosome. Antigenic variation is the process by which the trypanosome switches from one coat to another. Here, David Barry and Michael Turner consider this phenomenon within the context of the course of trypanosome infection.