Apicomplexan parasite adhesins: novel strategies for targeting host cell carbohydrates

Apicomplexan parasites such as Plasmodium spp. (malaria) and Toxoplasma gondii (toxoplasmosis) are significant global pathogens of humans and animals. Unlike many intracellular bacterial and viral pathogens that rely on host cell uptake machinery to gain entry, apicomplexan parasites promote recognition, attachment and ultimately invasion of host cells through an orchestrated delivery of adhesins. While several of these adhesins are now known to target host cell glycans, only recently have atomic level insights been forthcoming. Here we review recent developments in defining detailed molecular blueprints used by these widespread pathogens to drive host cell adhesion and promote infectivity.