Babesia bovis: Subcellular localization of host erythrocyte membrane components during their asexual growth

• Published in: Experimental parasitology 2007-05, Vol.116 (1), p.91-94
• Main Authors: Okamura, Masashi, Yokoyama, Naoaki, Takabatake, Noriyuki, Okubo, Kazuhiro, Ikehara, Yuzuru, Igarashi, Ikuo
• Format: Article
• Language: English
• Subjects: Animals; Asexual growth; Babesia bovis; Babesia bovis ( B. bovis); Babesia bovis - growth & development; Babesia bovis - ultrastructure; Babesia equi ( B. equi); babesiosis; Biological and medical sciences; biological development; Cattle; cell invasion; cell membranes; chemical composition; Erythrocyte Membrane - parasitology; Erythrocyte Membrane - ultrastructure; Erythrocytes; Erythrocytes - parasitology; Erythrocytes - ultrastructure; Fundamental and applied biological sciences. Psychology; Host-parasite interaction; Host-Parasite Interactions; host-parasite relationships; infection; intracellular parasites; Life cycle. Host-agent relationship. Pathogenesis; Lipid bilayer; lipid bilayers; Localization; Maackia amurensis lectin II; MALII; Microscopy, Confocal - veterinary; parasitophorous vacuole; PBS; phosphate-buffered saline; Protozoa; RBC; red blood cell; room temperature; sialic acid; sialic acids
• ISSN: 0014-4894; 1090-2449
• DOI: 10.1016/j.exppara.2006.11.006

In the present study, the subcellular localization of the host red blood cell (RBC) membrane components, the α2-3-linked sialic acid (SA) residues and the lipid bilayer, was observed during the asexual growth of Babesia bovis using two erythrocyte probes, the SA-specific lectin (MALII) and the lipophilic fluorescent (PKH2) probes, respectively. In confocal laser scanning microscopy with MALII, the SA residues on the surface of parasitized RBCs appeared to accumulate into the intracellular parasites as the parasites matured as well as to remain on the surface of extracellular parasites. Furthermore, when PKH2-labeled RBCs were infected with B. bovis, PKH2 signals were also observed around both the intracellular and the extracellular parasites, similarly to the results of MALII. These results indicated that the components derived from the host erythrocyte membrane are incorporated into the intracellular parasites during their asexual growth within the parasitized RBC, suggesting the possible formation of a parasitophorous vacuole-based network or a parasite surface coat.