Amount of cholesterol in host membrane affects erythrocyte invasion and replication byBabesia bovis

Abstract

SUMMARYCholesterol is a major component of the erythrocyte membrane. In the present study, we investigated the effects of cholesterol reduction in host bovine erythrocytes (RBC) on the growth ofBabesia bovis, a major bovine haemoprotozoon. Anin vitrogrowth assay with bovine RBC that had been prepared by pre-treatment with a cholesterol depletion agent (methyl-β-cyclodextrin, MCD) showed that the culture with 5 mmMCD-treated RBC inhibited the growth ofB. bovissignificantly as compared with that with the control RBC. In further experiments, the treatment with 5 mmMCD was proved to suppress both activities of the parasite, erythrocyte invasion and replication within the infected RBC. In contrast, a slight reduction in the membrane cholesterol by 1 mmMCD treatment promoted both their growth and erythrocyte invasion activity. These results indicate that erythrocyte invasion and replication byB. bovisare affected by the amount of cholesterol in the host erythrocyte membrane.