Up-regulated expression of spherical body protein 2 truncated copy 11 in Babesia bovis is associated with reduced cytoadhesion to vascular endothelial cells

Gina M Gallego-Lopez; Audrey O T Lau; Roberta M O'Connor; Massaro W Ueti; Brian M Cooke; Jacob M Laughery; Telmo Graça; Sally A Madsen-Bouterse; Daiane P Oldiges; David R Allred; Carlos E Suarez

doi:10.1016/j.ijpara.2018.05.015

Up-regulated expression of spherical body protein 2 truncated copy 11 in Babesia bovis is associated with reduced cytoadhesion to vascular endothelial cells

Int J Parasitol. 2019 Feb;49(2):127-137. doi: 10.1016/j.ijpara.2018.05.015. Epub 2018 Oct 25.

Affiliations

¹ Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-7040, USA.
² The National Institutes of Health, National Institute of Allergy and Infectious Diseases, DEA, Rockville, MD 20852, USA.
³ Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-7040, USA; Animal Disease Research Unit, Agricultural Research Service, USDA, Pullman, WA 99164-6630, USA.
⁴ Department of Microbiology, Biomedicine Discovery Institute, Monash University, Victoria 3800, Australia.
⁵ Paul G. Allen School for Global Animal Health, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-7040, USA.
⁶ Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
⁷ Department of Infectious Diseases and Immunology, Emerging Pathogens Institute University of Florida, Gainesville, FL 32611-0880, USA.
⁸ Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-7040, USA; Animal Disease Research Unit, Agricultural Research Service, USDA, Pullman, WA 99164-6630, USA. Electronic address: suarez@wsu.edu.

PMID: 30367864
DOI: 10.1016/j.ijpara.2018.05.015

Abstract

The factors involved in gain or loss of virulence in Babesia bovis are unknown. Spherical body protein 2 truncated copy 11 (sbp2t11) transcripts in B. bovis were recently reported to be a marker of attenuation for B. bovis strains. Increased cytoadhesion of B. bovis-infected red blood cells (iRBC) to vascular endothelial cells is associated with severe disease outcomes and an indicator of parasite virulence. Here, we created a stable B. bovis transfected line over-expressing sbp2t11 to determine whether up-regulation of sbp2t11 is associated with changes in cytoadhesion. This line was designated sbp2t11up and five B. bovis clonal lines were derived from the sbp2t11up line by limiting dilution for characterisation. We compared the ability of iRBCs from the sbp2t11up line and its five derivative clonal lines to adhere to bovine brain endothelial cells, using an in vitro cytoadhesion assay. The same lines were selected for in vitro cytoadhesion and the levels of sbp2t11 transcripts in each selected line were quantified. Our results demonstrate that up-regulation of sbp2t11 is accompanied by a statistically significant reduction in cytoadhesion. Confirmed up-regulation of sbp2t11 in B. bovis concomitant with the reduction of iRBC in vitro cytoadhesion to bovine brain endothelial cell is consistent with our previous finding that up-regulation of sbp2t11 is an attenuation marker in B. bovis and suggests the involvement of sbp2t11 transcription in B. bovis virulence.

Keywords: BBEC; Babesia bovis; Cytoadhesion; Spherical body protein; Stable transfection.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Animals
Babesia bovis / genetics
Babesia bovis / physiology*
Cattle
Cell Adhesion*
Cells, Cultured
Endothelial Cells / parasitology*
Gene Expression*
Protozoan Proteins / biosynthesis*
Protozoan Proteins / genetics
Virulence Factors / biosynthesis*
Virulence Factors / genetics

Substances

Protozoan Proteins
Virulence Factors
spherical body protein 2, Babesia bovis