title: The TvLEGU-1, a legumain-like cysteine proteinase, plays a key role in Trichomonas vaginalis cytoadherence.
abstract: The goal of this paper was to characterize a Trichomonas vaginalis cysteine proteinase (CP) legumain-1 (TvLEGU-1) and determine its potential role as a virulence factor during T. vaginalis infection. A 30-kDa band, which migrates in three protein spots (pI~6.3, ~6.5, and ~6.7) with a different type and level of phosphorylation, was identified as TvLEGU-1 by one- and two-dimensional Western blot (WB) assays, using a protease-rich trichomonad extract and polyclonal antibodies produced against the recombinant TvLEGU-1 (anti-TvLEGU-1r). Its identification was confirmed by mass spectrometry. Immunofluorescence, cell binding, and WB assays showed that TvLEGU-1 is upregulated by iron at the protein level, localized on the trichomonad surface and in lysosomes and Golgi complex, bound to the surface of HeLa cells, and was found in vaginal secretions. Additionally, the IgG and Fab fractions of the anti-TvLEGU-1r antibody inhibited trichomonal cytoadherence up to 45%. Moreover, the Aza-Peptidyl Michael Acceptor that inhibited legumain proteolytic activity in live parasites also reduced levels of trichomonal cytoadherence up to 80%. In conclusion, our data show that the proteolytic activity of TvLEGU-1 is necessary for trichomonal adherence. Thus, TvLEGU-1 is a novel virulence factor upregulated by iron. This is the first report that a legumain-like CP plays a role in a pathogen cytoadherence.
authors.affiliation: Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Avenida IPN No. 2508, Col. San Pedro Zacatenco, 07360 Mexico City, DF, Mexico.
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Rendón-Gandarilla
authors.forename: Lucero de Los Angeles
authors.initials: Lde L
authors.lastname: Ramón-Luing
authors.forename: Jaime
authors.initials: J
authors.lastname: Ortega-López
authors.forename: Ivone
authors.initials: I
authors.lastname: Rosa de Andrade
authors.forename: Marlene
authors.initials: M
authors.lastname: Benchimol
authors.forename: Rossana
authors.initials: R
authors.lastname: Arroyo
mesh_terms: D002448:Cell Adhesion; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D057056:Cysteine Proteases / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D005260:Female; D006056:Golgi Apparatus / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007501:Iron / Q000378:metabolism; D008099:Liver / Q000469:parasitology; D010766:Phosphorylation; D015800:Protozoan Proteins / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D011994:Recombinant Proteins / Q000378:metabolism; D014247:Trichomonas Vaginitis / Q000469:parasitology; D014246:Trichomonas vaginalis / Q000201:enzymology* / Q000472:pathogenicity; D014621:Vagina / Q000469:parasitology; D037521:Virulence Factors / Q000378:metabolism; D000099240:Asparaginyl Endopeptidase
chemical_list: D003546:Cysteine Endopeptidases; D057056:Cysteine Proteases; D007074:Immunoglobulin G; D007501:Iron; D015800:Protozoan Proteins; D011994:Recombinant Proteins; D037521:Virulence Factors; D000099240:Asparaginyl Endopeptidase; C584302:LEGU-1 protein, Trichomonas vaginalis