Besnoitia besnoiti tachyzoite replication in bovine primary endothelial cells relies on host Niemann–Pick type C protein 1 for cholesterol acquisition

<i>Besnoitia besnoiti</i> is a cyst-forming apicomplexan parasite and the causal agent of bovine besnoitiosis. During early phase of infection, tachyzoites replicate within host endothelial cells in a host cell cholesterol-dependent process. By applying U18666A treatments, we here evaluated the role of Niemann-Pick type C protein 1 (NPC1) in both, intracellular <i>B. besnoiti</i> replication and host cellular cholesterol distribution. Additionally, <i>B. besnoiti</i>-driven changes in NPC1 gene transcription were studied by qPCR. Overall, U18666A treatments significantly reduced <i>B. besnoiti</i> proliferation and induced cholesterol accumulation in host cytoplasmic dense vesicles. However, NPC1 gene transcription was not affected by <i>B. besnoiti</i> infection.