To Be or Not to Be a Tapeworm Parasite: That Is the Post-Genomic Question in Taenia solium Cysticercosis

Abstract

Cestode parasites rely on their host to obtain their nutrients. Elucidation of tapeworm genomes has shown a remarkable reduction in the coding of multiple enzymes, particularly those of anabolic pathways. Previous findings showed that 10–13% of the proteins found in the vesicular fluid of Taenia solium cysticerci are of host origin. Further proteomic characterization allowed identification of 4,259 different proteins including 891 of host origin in the parasite’s protein lysates. One explanation for this high abundance and diversity of host proteins in the parasite lysates is related to the functional exploitation of host proteins by cysticerci. Supporting this concept is the uptake of host haptoglobin and hemoglobin by the parasite, as a way to acquire iron. Surprisingly, internalized host proteins are minimally degraded by the parasite physiological machinery. Additional proteomic analysis demonstrated that these host proteins become part of the organic matrix of calcareous corpuscles; as 60–70% of the protein content are host proteins. In this review, a collection of available genomic and proteomic data for taeniid cestodes is assembled, the subject of the use and processing of host proteins is particularly addressed; a sketchy and unique cell physiological profile starts to emerge for these parasitic organisms.

Evolution of codon usage in Taenia saginata genomes and its impact on the host

“…However, in addition to the classic strain of this parasite found in southern regions, which is associated with cattle raising, there is a lesser known form of T. saginata in northern regions ( 20 ). Taenia saginata produces long-term infections, being able to survive within its host for several years, maintaining a dynamic and complex host-parasite relationship ( 23 , 24 ). Taenia saginata lives in cattle as an intermediate host while in humans as a definitive host ( 15 ).…”