A short-term treatment with BKI-1294 does not protect foetuses from sheep experimentally infected with Neospora caninum tachyzoites during pregnancy. (December 2021)

• Record Type: Journal Article
• Authors: Sánchez-Sánchez, Roberto; Ferre, Ignacio; Re, Michela; Pérez-Arroyo, Bárbara; Cleofé-Resta, Darío; García, Victor Herrero; Díaz, Manuel Pizarro; Ferrer, Luis Miguel; Ruiz, Hector; Vallejo-García, Raquel; Benavides, Julio; Hulverson, Matthew A.; Choi, Ryan; Whitman, Grant R.; Hemphill, Andrew; Van Voorhis, Wesley C.; Ortega-Mora, Luis Miguel
• Is Part Of: International journal for parasitology. Volume 17(2021)
• Page Start: 176
• Page End: 185
• Publication Date: 2021-12
• Subjects: Neospora caninum -- Sheep -- Experimental chemotherapy -- Abortion -- Vertical transmission -- BKI-1294; Parasitic diseases -- Chemotherapy -- Periodicals; Drug resistance -- Periodicals; 616.96061
• DOI: 10.1016/j.ijpddr.2021.10.001
• Languages: English
• ISSNs: 2211-3207

Abstract

Abstract: The Neospora caninum Calcium-dependent protein kinase 1 (NcCDPK1) inhibitor BKI-1294 had demonstrated excellent efficacy in a pregnant mouse model of neosporosis, and was also highly efficacious in a pregnant sheep model of toxoplasmosis. In this work, we present the efficacy of BKI-1294 treatment (dosed 5 times orally every 48 h) starting 48 h after intravenous infection of sheep with 10 5 Nc-Spain7 tachyzoites at mid-pregnancy. In the dams, BKI-1294 plasma concentrations were above the IC50 for N. caninum for 12–15 days. In treated sheep, when they were compared to untreated ones, we observed a minor increase in rectal temperature, higher IFNγ levels after blood stimulation in vitro, and a minor increase of IgG levels against N. caninum soluble antigens through day 28 post-infection. Additionally, the anti-NcSAG1 and anti-NcSAG4 IgGs were lower in treated dams on days 21 and 42 post-infection. However, BKI-1294 did not protect against abortion (87% foetal mortality in both infected groups, treated and untreated) and did not reduce transplacental transmission, parasite load or lesions in placentomes and foetal brain. The lack of foetal protection was likely caused by short systemic exposure in the dams and suboptimal foetal exposure to this parasitostatic drug, which was unable to reduce replication of the likely established N. caninum tachyzoites in the foetus at the moment of treatment. New BKIs with a very low plasma clearance and good ability to cross the blood-brain and placental barriers need to be developed. Graphical abstract: Image 1 Highlights: BKI-1294 triggers a transiently decrease in anti- N. caninum IgG levels in sheep. BKI-1294 does not protect against abortion and vertical transmission of N. caninum. The efficacy of BKI-1294 is different in pregnant mice and sheep models of neosporosis.