Structure and molecular composition of Toxoplasma gondii pellicle

Toxoplasma gondii is one of the most successful protozoan parasites in the world, chronically infecting around 25-30 % of the human population. As a member of the phylum Apicomplexa, Toxoplasma has unique cellular structures, the best known being the apical complex and, no less notable, a trilaminar pellicle structure formed by the plasma membrane on top of a set of flattened membranous sacs (alveoli) called inner membrane complex. As an obligated intracellular pathogen, T. gondii pellicle contains an arsenal of proteins involved in host cell recognition and adhesion, which are crucial for cell invasion. Besides, the pellicle also houses molecular motor machinery that drives the parasite gliding motility. Thus, this chapter will dissect the structure of the pellicle and will also address its main molecular components.