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. 1984 Aug 1;160(2):398–410. doi: 10.1084/jem.160.2.398

Iron uptake and increased intracellular enzyme activity follow host lactoferrin binding by Trichomonas vaginalis receptors

PMCID: PMC2187462  PMID: 6088662

Abstract

Lactoferrin acquisition and iron uptake by pathogenic Trichomonas vaginalis was examined. Saturation binding kinetics were obtained for trichomonads using increasing amounts of radioiodinated lactoferrin, while no significant binding by transferrin under similar conditions was achieved. Only unlabeled lactoferrin successfully and stoichiometrically competed with 125I-labeled lactoferrin binding. Time course studies showed maximal lactoferrin binding by 30 min at 37 degrees C. Data suggest no internalization of bound lactoferrin. The accumulation of radioactivity in supernatants after incubation of T. vaginalis with 125I-labeled lactoferrin and washing in PBS suggested the presence of low affinity sites for this host macromolecule. Scatchard analysis indicated the presence of 90,000 receptors per trichomonad with an apparent Kd of 1.0 microM. Two trichomonad lactoferrin binding proteins were identified by affinity chromatography and immunoprecipitation of receptor-ligand complexes. A 30-fold accumulation of iron was achieved using 59Fe-lactoferrin when compared to the steady state concentration of bound lactoferrin. The activity of pyruvate/ferrodoxin oxidoreductase, an enzyme involved in trichomonal energy metabolism, increased more than sixfold following exposure of the parasites to lactoferrin, demonstrating a biologic response to the receptor-mediated binding of lactoferrin. These data suggest that T. vaginalis possesses specific receptors for biologically relevant host proteins and that these receptors contribute to the metabolic processes of the parasites.

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Selected References

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  1. Aisen P., Leibman A. Lactoferrin and transferrin: a comparative study. Biochim Biophys Acta. 1972 Feb 29;257(2):314–323. doi: 10.1016/0005-2795(72)90283-8. [DOI] [PubMed] [Google Scholar]
  2. Alderete J. F. Identification of immunogenic and antibody-binding membrane proteins of pathogenic Trichomonas vaginalis. Infect Immun. 1983 Apr;40(1):284–291. doi: 10.1128/iai.40.1.284-291.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Brener D., DeVoe I. W., Holbein B. E. Increased virulence of Neisseria meningitidis after in vitro iron-limited growth at low pH. Infect Immun. 1981 Jul;33(1):59–66. doi: 10.1128/iai.33.1.59-66.1981. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Bullen J. J., Rogers H. J., Griffiths E. Role of iron in bacterial infection. Curr Top Microbiol Immunol. 1978;80:1–35. doi: 10.1007/978-3-642-66956-9_1. [DOI] [PubMed] [Google Scholar]
  5. Cuatrecasas P., Wilchek M., Anfinsen C. B. Selective enzyme purification by affinity chromatography. Proc Natl Acad Sci U S A. 1968 Oct;61(2):636–643. doi: 10.1073/pnas.61.2.636. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Diamond L. S. Techniques of axenic cultivation of Entamoeba histolytica Schaudinn, 1903 and E. histolytica-like amebae. J Parasitol. 1968 Oct;54(5):1047–1056. [PubMed] [Google Scholar]
  7. Feldman H. A. Mathematical theory of complex ligand-binding systems of equilibrium: some methods for parameter fitting. Anal Biochem. 1972 Aug;48(2):317–338. doi: 10.1016/0003-2697(72)90084-x. [DOI] [PubMed] [Google Scholar]
  8. Krieger J. N., Poisson M. A., Rein M. F. Beta-hemolytic activity of Trichomonas vaginalis correlates with virulence. Infect Immun. 1983 Sep;41(3):1291–1295. doi: 10.1128/iai.41.3.1291-1295.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Krieger J. N. Urologic aspects of trichomoniasis. Invest Urol. 1981 May;18(8):411–417. [PubMed] [Google Scholar]
  10. Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
  11. Marczak R., Gorrell T. E., Müller M. Hydrogenosomal ferredoxin of the anaerobic protozoon, Tritrichomonas foetus. J Biol Chem. 1983 Oct 25;258(20):12427–12433. [PubMed] [Google Scholar]
  12. Masson P. L., Heremans J. F., Prignot J. J., Wauters G. Immunohistochemical localization and bacteriostatic properties of an iron-binding protein from bronchial mucus. Thorax. 1966 Nov;21(6):538–544. doi: 10.1136/thx.21.6.538. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Masson P. L., Heremans J. F., Schonne E. Lactoferrin, an iron-binding protein in neutrophilic leukocytes. J Exp Med. 1969 Sep 1;130(3):643–658. doi: 10.1084/jem.130.3.643. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Mickelsen P. A., Blackman E., Sparling P. F. Ability of Neisseria gonorrhoeae, Neisseria meningitidis, and commensal Neisseria species to obtain iron from lactoferrin. Infect Immun. 1982 Mar;35(3):915–920. doi: 10.1128/iai.35.3.915-920.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Müller M., Gorrell T. E. Metabolism and metronidazole uptake in Trichomonas vaginalis isolates with different metronidazole susceptibilities. Antimicrob Agents Chemother. 1983 Nov;24(5):667–673. doi: 10.1128/aac.24.5.667. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Ouaissi M. A., Afchain D., Capron A., Grimaud J. A. Fibronectin receptors on Trypanosoma cruzi trypomastigotes and their biological function. Nature. 1984 Mar 22;308(5957):380–382. doi: 10.1038/308380a0. [DOI] [PubMed] [Google Scholar]
  17. Peterson K. M., Alderete J. F. Acquisition of alpha 1-Antitrypsin by a pathogenic strain of Trichomonas vaginalis. Infect Immun. 1983 May;40(2):640–646. doi: 10.1128/iai.40.2.640-646.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Peterson K. M., Alderete J. F. Host plasma proteins on the surface of pathogenic Trichomonas vaginalis. Infect Immun. 1982 Aug;37(2):755–762. doi: 10.1128/iai.37.2.755-762.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Peterson K. M., Baseman J. B., Alderete J. F. Treponema pallidum receptor binding proteins interact with fibronectin. J Exp Med. 1983 Jun 1;157(6):1958–1970. doi: 10.1084/jem.157.6.1958. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Proia R. L., Hart D. A., Holmes R. K., Holmes K. V., Eidels L. Immunoprecipitation and partial characterization of diphtheria toxin-binding glycoproteins from surface of guinea pig cells. Proc Natl Acad Sci U S A. 1979 Feb;76(2):685–689. doi: 10.1073/pnas.76.2.685. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Simonson C., Brener D., DeVoe I. W. Expression of a high-affinity mechanism for acquisition of transferrin iron by Neisseria meningitidis. Infect Immun. 1982 Apr;36(1):107–113. doi: 10.1128/iai.36.1.107-113.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Spence M. R., Hollander D. H., Smith J., McCaig L., Sewell D., Brockman M. The clinical and laboratory diagnosis of Trichomonas vaginalis infection. Sex Transm Dis. 1980 Oct-Dec;7(4):168–171. doi: 10.1097/00007435-198010000-00004. [DOI] [PubMed] [Google Scholar]
  23. Whitnack E., Beachey E. H. Antiopsonic activity of fibrinogen bound to M protein on the surface of group A streptococci. J Clin Invest. 1982 Apr;69(4):1042–1045. doi: 10.1172/JCI110508. [DOI] [PMC free article] [PubMed] [Google Scholar]

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