Thiosemicarbazone Copper Chelator BLT-1 Blocks Apicomplexan Parasite Replication by Selective Inhibition of Scavenger Receptor B Type 1 (SR-BI)

Coccidian parasites are obligate intracellular pathogens that affect humans and animals. Apicomplexans are defective in de novo synthesis of cholesterol, which is required for membrane biosynthesis and offspring formation. In consequence, cholesterol has to be scavenged from host cells. It is mainly...

Full description

Saved in:
Bibliographic Details
Main Authors: Camilo Larrazabal, Sara López-Osorio, Zahady D. Velásquez, Carlos Hermosilla, Anja Taubert, Liliana M. R. Silva
Format: article
Language:EN
Published: MDPI AG 2021
Subjects:
Online Access:https://doaj.org/article/24fecbc6af05416292a514b764d8e898
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Coccidian parasites are obligate intracellular pathogens that affect humans and animals. Apicomplexans are defective in de novo synthesis of cholesterol, which is required for membrane biosynthesis and offspring formation. In consequence, cholesterol has to be scavenged from host cells. It is mainly taken up from extracellular sources via LDL particles; however, little is known on the role of HDL and its receptor SR-BI in this process. Here, we studied effects of the SR-BI-specific blocker BLT-1 on the development of different fast (<i>Toxoplasma gondii</i>, <i>Neospora caninum</i>, <i>Besnoitia besnoiti</i>) and slow (<i>Eimeria bovis</i> and <i>Eimeria arloingi)</i> replicating coccidian species. Overall, development of all these parasites was significantly inhibited by BLT-1 treatment indicating a common SR-BI-related key mechanism in the replication process. However, SR-BI gene transcription was not affected by <i>T. gondii, N. caninum</i> and <i>B. besnoiti</i> infections. Interestingly, BLT-1 treatment of infective stages reduced invasive capacities of all fast replicating parasites paralleled by a sustained increase in cytoplasmic Ca<sup>++</sup> levels. Moreover, BLT1-mediated blockage of SR-BI led to enhanced host cell lipid droplet abundance and neutral lipid content, thereby confirming the importance of this receptor in general lipid metabolism. Finally, the current data suggest a conserved role of SR-BI for successful coccidian infections.