title: Trypanosoma cruzi: a specific surface marker for the amastigote form.
abstract: 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.
authors.affiliation: Department of Microbiology and Public Health, Michigan State University, East Lansing 48824-1101.
authors.forename: M F
authors.initials: MF
authors.lastname: Lima
authors.forename: L A
authors.initials: LA
authors.lastname: Beltz
authors.forename: F
authors.initials: F
authors.lastname: Kierszenbaum
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D005455:Fluorescent Antibody Technique; D007700:Kinetics; D007781:Lactoferrin / Q000378:metabolism*; D007782:Lactoglobulins / Q000378:metabolism*; D051379:Mice; D011956:Receptors, Cell Surface / Q000378:metabolism*; D014349:Trypanosoma cruzi / Q000254:growth & development / Q000378:metabolism*
chemical_list: D007782:Lactoglobulins; D011956:Receptors, Cell Surface; C038340:lactoferrin receptors; D007781:Lactoferrin