Continuous in vitro culture of Babesia divergens in a serum-free medium.
Babesia divergens was cultivated in RPMI 1640 (25 mM HEPES) supplemented with 10% human serum (RPMI-10% HS) with a high percentage of parasitized erythrocytes (PPE) (> or = 40%). Standardization of in vitro tests, purification of exoantigens, biochemical studies and the safety of the culture handler motivated the development of a serum-free defined medium. Removal of serum greatly reduced the PPE but, after a period of adaptation, the culture was continuous and the parasite was able to develop a 3% routine PPE. Addition of vitamins or reduced glutathione in basal medium (RPMI) did not improve the PPE. The supplementation of basal medium with lipidic carrier (Albumax I or bovine serum albumin-Cohn's fraction V) promoted the growth of B. divergens with high PPE (> 30%) close to those obtained in RPMI-10% HS. Neither protein nor lipid fractions alone were able to restore the growth of B. divergens. Nevertheless, the whole lipid fraction from serum or Albumax I added to delipidated albumin partially restored the growth (7% PPE), indicating that the presentation of specific lipids by a carrier is crucial for the parasite. All the data indicate that Albumax I can replace human serum offering the advantages of safety, standardization for chemosensitivity tests, and exoantigen purification.
Grande
N
N
Laboratoire de Biologie Cellulaire et Moléculaire, UPRES No. 699, UFR des Sciences Pharmaceutiques et Biologiques, Montpellier, France.
Precigout
E
E
Ancelin
M L
ML
Moubri
K
K
Carcy
B
B
Lemesre
J L
JL
Vial
H
H
Gorenflot
A
A
D000818:Animals; D001403:Babesia / Q000166:cytology / Q000254:growth & development*; D016895:Culture Media, Serum-Free; D005227:Fatty Acids; D006801:Humans; D008055:Lipids / Q000494:pharmacology; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D014815:Vitamins / Q000494:pharmacology
D016895:Culture Media, Serum-Free; D005227:Fatty Acids; D008055:Lipids; D014815:Vitamins; D012710:Serum Albumin, Bovine