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. 1991 Aug 1;174(2):311–318. doi: 10.1084/jem.174.2.311

The regulation by iron of the synthesis of adhesins and cytoadherence levels in the protozoan Trichomonas vaginalis

PMCID: PMC2118921  PMID: 1856625

Abstract

Levels of adherence of Trichomonas vaginalis to epithelial cells was found to be modulated by iron. Cytoadherence values were greater than or equal to twofold higher for trichomonads grown in a complex cultivation medium supplemented with iron. This increase in adherence levels was specifically mediated by iron; parasites cultured in a low- iron medium in the presence of salts other than iron were unresponsive to changes in adherence levels. Expression of the higher adherence property, by parasites grown first in low-iron medium followed by supplementation with iron, was a function of time, and the extent of cytoadherence was proportional to the concentration of iron added to the medium. Lactoferrin, an important iron source for trichomonads at the site of infection, elevated adherence of the parasite to epithelial cells, demonstrating the likely in vivo modulation of adherence by iron. The alteration of levels of adherence caused by iron was determined to be a reflection of gene expression of previously characterized trichomonad adhesins. Parasites grown under iron-replete conditions had higher quantities of surface-exposed adhesins, and this was a result of increased synthesis of adhesins. Actinomycin D and alpha-amanitin prevented expression of adhesin molecules, which resulted in decreased cytoadherence, showing that adhesin synthesis was dependent on gene transcription. Data indicated that genes encoding the four trichomonad adhesins are coordinately regulated by iron.

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Selected References

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  1. Alderete J. F. Antigen analysis of several pathogenic strains of Trichomonas vaginalis. Infect Immun. 1983 Mar;39(3):1041–1047. doi: 10.1128/iai.39.3.1041-1047.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Alderete J. F., Demeś P., Gombosova A., Valent M., Fabusová M., Jánoska A., Stefanovic J., Arroyo R. Specific parasitism of purified vaginal epithelial cells by Trichomonas vaginalis. Infect Immun. 1988 Oct;56(10):2558–2562. doi: 10.1128/iai.56.10.2558-2562.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Alderete J. F., Garza G. E. Identification and properties of Trichomonas vaginalis proteins involved in cytadherence. Infect Immun. 1988 Jan;56(1):28–33. doi: 10.1128/iai.56.1.28-33.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Alderete J. F., Garza G. E. Specific nature of Trichomonas vaginalis parasitism of host cell surfaces. Infect Immun. 1985 Dec;50(3):701–708. doi: 10.1128/iai.50.3.701-708.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. 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]
  6. Alderete J. F., Neale K. A. Relatedness of structures of a major immunogen in Trichomonas vaginalis isolates. Infect Immun. 1989 Jun;57(6):1849–1853. doi: 10.1128/iai.57.6.1849-1853.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Alderete J. F., Suprun-Brown L., Kasmala L., Smith J., Spence M. Heterogeneity of Trichomonas vaginalis and discrimination among trichomonal isolates and subpopulations with sera of patients and experimentally infected mice. Infect Immun. 1985 Sep;49(3):463–468. doi: 10.1128/iai.49.3.463-468.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Arroyo R., Alderete J. F. Trichomonas vaginalis surface proteinase activity is necessary for parasite adherence to epithelial cells. Infect Immun. 1989 Oct;57(10):2991–2997. doi: 10.1128/iai.57.10.2991-2997.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Avots-Avotins A. E., Fader R. C., Davis C. P. Environmental alteration and two distinct mechanisms of E. coli adherence to bladder epithelial cells. Invest Urol. 1981 Mar;18(5):364–370. [PubMed] [Google Scholar]
  10. Cohen M. S., Britigan B. E., French M., Bean K. Preliminary observations on lactoferrin secretion in human vaginal mucus: variation during the menstrual cycle, evidence of hormonal regulation, and implications for infection with Neisseria gonorrhoeae. Am J Obstet Gynecol. 1987 Nov;157(5):1122–1125. doi: 10.1016/s0002-9378(87)80274-0. [DOI] [PubMed] [Google Scholar]
  11. Eisenstein B. I., Dodd D. C. Pseudocatabolite repression of type 1 fimbriae of Escherichia coli. J Bacteriol. 1982 Sep;151(3):1560–1567. doi: 10.1128/jb.151.3.1560-1567.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Gorrell T. E. Effect of culture medium iron content on the biochemical composition and metabolism of Trichomonas vaginalis. J Bacteriol. 1985 Mar;161(3):1228–1230. doi: 10.1128/jb.161.3.1228-1230.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Hennecke H. Regulation of bacterial gene expression by metal-protein complexes. Mol Microbiol. 1990 Oct;4(10):1621–1628. doi: 10.1111/j.1365-2958.1990.tb00538.x. [DOI] [PubMed] [Google Scholar]
  14. Kennedy M. J., Rogers A. L., Yancey R. J., Jr Environmental alteration and phenotypic regulation of Candida albicans adhesion to plastic. Infect Immun. 1989 Dec;57(12):3876–3881. doi: 10.1128/iai.57.12.3876-3881.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. 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]
  16. Lee C. A., Falkow S. The ability of Salmonella to enter mammalian cells is affected by bacterial growth state. Proc Natl Acad Sci U S A. 1990 Jun;87(11):4304–4308. doi: 10.1073/pnas.87.11.4304. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Lehker M. W., Alderete J. F. Properties of Trichomonas vaginalis grown under chemostat controlled growth conditions. Genitourin Med. 1990 Jun;66(3):193–199. doi: 10.1136/sti.66.3.193. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Lehker M. W., Chang T. H., Dailey D. C., Alderete J. F. Specific erythrocyte binding is an additional nutrient acquisition system for Trichomonas vaginalis. J Exp Med. 1990 Jun 1;171(6):2165–2170. doi: 10.1084/jem.171.6.2165. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Lockwood B. C., North M. J., Coombs G. H. The release of hydrolases from Trichomonas vaginalis and Tritrichomonas foetus. Mol Biochem Parasitol. 1988 Aug;30(2):135–142. doi: 10.1016/0166-6851(88)90106-5. [DOI] [PubMed] [Google Scholar]
  20. Mazurier J., Spik G. Comparative study of the iron-binding properties of human transferrins. I. Complete and sequential iron saturation and desaturation of the lactotransferrin. Biochim Biophys Acta. 1980 May 7;629(2):399–408. doi: 10.1016/0304-4165(80)90112-9. [DOI] [PubMed] [Google Scholar]
  21. Miller J. F., Mekalanos J. J., Falkow S. Coordinate regulation and sensory transduction in the control of bacterial virulence. Science. 1989 Feb 17;243(4893):916–922. doi: 10.1126/science.2537530. [DOI] [PubMed] [Google Scholar]
  22. Neale K. A., Alderete J. F. Analysis of the proteinases of representative Trichomonas vaginalis isolates. Infect Immun. 1990 Jan;58(1):157–162. doi: 10.1128/iai.58.1.157-162.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. 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]
  24. Peterson K. M., Alderete J. F. Iron uptake and increased intracellular enzyme activity follow host lactoferrin binding by Trichomonas vaginalis receptors. J Exp Med. 1984 Aug 1;160(2):398–410. doi: 10.1084/jem.160.2.398. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Theil E. C. Regulation of ferritin and transferrin receptor mRNAs. J Biol Chem. 1990 Mar 25;265(9):4771–4774. [PubMed] [Google Scholar]
  26. Towbin H., Staehelin T., Gordon J. Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. Proc Natl Acad Sci U S A. 1979 Sep;76(9):4350–4354. doi: 10.1073/pnas.76.9.4350. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Williams P. H., Hinson G. Temperature-dependent transcriptional regulation of expression of fimbriae in an Escherichia coli strain isolated from a child with severe enteritis. Infect Immun. 1987 Jul;55(7):1734–1736. doi: 10.1128/iai.55.7.1734-1736.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Worwood M. An overview of iron metabolism at a molecular level. J Intern Med. 1989 Nov;226(5):381–391. doi: 10.1111/j.1365-2796.1989.tb01412.x. [DOI] [PubMed] [Google Scholar]

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