Lima M F, Beltz L A, Kierszenbaum F
Department of Microbiology and Public Health, Michigan State University, East Lansing 48824-1101.
J Protozool. 1988 Feb;35(1):108-10. doi: 10.1111/j.1550-7408.1988.tb04086.x.
Among the known life cycle stages of Trypanosoma cruzi only the amastigote form bound lactoferrin (LF), a glycoprotein produced by neutrophils. This capacity was readily demonstrable by indirect immunofluorescence in amastigotes derived from mice, a mammalian cell culture, or grown in an axenic medium. No LF binding was detectable on trypomastigotes from blood or mammalian cells, insect-derived metacyclics or epimastigotes, or on epimastigotes grown in Warren's medium. Serum levels of LF were increased in mice acutely infected with T. cruzi, and amastigotes from the spleens of these animals were found to have the glycoprotein on their surface. The amastigote LF receptor may have biological significance in parasite-host interaction since mononuclear phagocytes also express a LF receptor, and treatment of these cells with LF has been shown to increase their capacities to take up and kill T. cruzi amastigotes in vitro. The LF receptor is the first marker for T. cruzi amastigotes for which a naturally occurring ligand has been described.
在克氏锥虫已知的生命周期阶段中，只有无鞭毛体形式能结合乳铁蛋白（LF），乳铁蛋白是一种由中性粒细胞产生的糖蛋白。通过间接免疫荧光法，在源自小鼠、哺乳动物细胞培养物或在无细胞培养基中生长的无鞭毛体中，这种结合能力很容易得到证实。在来自血液或哺乳动物细胞的锥鞭毛体、昆虫来源的循环后期锥鞭毛体或上鞭毛体，以及在沃伦培养基中生长的上鞭毛体上，均未检测到LF结合。急性感染克氏锥虫的小鼠血清中LF水平升高，并且在这些动物脾脏中的无鞭毛体表面发现了这种糖蛋白。无鞭毛体LF受体在寄生虫与宿主的相互作用中可能具有生物学意义，因为单核吞噬细胞也表达LF受体，并且已证明用LF处理这些细胞可增强它们在体外摄取和杀死克氏锥虫无鞭毛体的能力。LF受体是已描述了天然配体的克氏锥虫无鞭毛体的首个标志物。
