Glycophorin A-knockout mice, which lost sialoglycoproteins from the red blood cell membrane, are resistant to lethal infection of Babesia rodhaini.
Recent in vitro-based studies using several Babesia spp. have suggested that sialic acids and/or sialoglycoproteins on host red blood cells (RBCs) play an important role in their invasion of RBCs. In the present study, we analyzed the RBC characteristics of glycophorin A (GPA)-knockout mice and studied their in vivo susceptibility to lethal infection of Babesia rodhaini for the first time. In immunoblot and lectin blot analyses, glycoproteins containing O-linked oligosaccharides terminated with alpha2-3-linked sialic acids disappeared from the RBCs of GPA homozygous ((-/-)) mice. Flow cytometric analysis showed a remarkable reduction of Maackia amurensis lectin II binding to the surface of GPA(-/-) RBCs relative to control RBCs, indicating an appreciable loss of alpha2-3-linked sialic acids on the RBC surface of GPA(-/-) mice. Importantly, while B. rodhaini caused lethal infection in wild-type mice, the infected GPA(-/-) mice showed inhibition of parasite growth and eventually survived. These results indicate that RBC sialoglycoproteins lost in GPA(-/-) mice are involved in the in vivo growth of B. rodhaini, probably functioning as essential molecule(s) for the parasite invasion of host RBCs in the blood circulation.
Takabatake
Noriyuki
N
National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
Okamura
Masashi
M
Yokoyama
Naoaki
N
Ikehara
Yuzuru
Y
Akimitsu
Nobuyoshi
N
Arimitsu
Nagisa
N
Hamamoto
Hiroshi
H
Sekimizu
Kazuhisa
K
Suzuki
Hiroshi
H
Igarashi
Ikuo
I
D000818:Animals; D000941:Antigens; D001403:Babesia / Q000472:pathogenicity*; D001404:Babesiosis / Q000276:immunology / Q000662:veterinary*; D004198:Disease Susceptibility / Q000662:veterinary; D004910:Erythrocyte Membrane / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry / Q000379:methods / Q000662:veterinary; D005455:Fluorescent Antibody Technique / Q000662:veterinary; D006021:Glycophorins / Q000276:immunology* / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D009844:Oligosaccharides / Q000032:analysis / Q000737:chemistry; D013997:Time Factors
D000941:Antigens; D006021:Glycophorins; D009844:Oligosaccharides