title: Characterization of Trichomonas vaginalis AP33 adhesin and cell surface interactive domains.
abstract: Adherence to host target cells is a critical step in establishing infection with the sexually transmitted pathogen Trichomonas vaginalis. Four parasite surface proteins mediating attachment to vaginal epithelial cells have been identified. One surface protein, termed AP33, was characterized further to identify domains interactive with previously generated antibodies and with host surface sites. N- and C-terminal deletion subclones were generated and tested for reactivity with both mAb and rabbit antiserum against AP33, and were also examined for their ability to bind to host cells. Surprisingly, the rabbit antiserum known to inhibit cytoadherence recognized an epitope(s) contained within 72 residues in the N-terminal half of the protein. However, the mAb epitope was immunoreactive with a 28-amino-acid region near the C-terminus. Subsequent mapping of this region with overlapping peptides identified a nine-amino-acid sequence reactive with the mAb. Equally surprising, two domains interactive with host cell surfaces were identified at distinct parts of AP33: one in the N-terminal half of the protein, and the other within 24 residues in the C-terminal third. Further analysis of the C-terminal binding domain revealed that a peptide representing this area could inhibit T. vaginalis cytoadherence by 40%.
authors.affiliation: Department of Microbiology, The University of Texas Health Science Center,7703 Floyd Curl Drive, San Antonio, TX 78284-7758,USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Engbring
authors.affiliation: Department of Microbiology, The University of Texas Health Science Center,7703 Floyd Curl Drive, San Antonio, TX 78284-7758,USA.
authors.forename: J F
authors.initials: JF
authors.lastname: Alderete
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D002448:Cell Adhesion; D003001:Cloning, Molecular; D018076:DNA, Complementary; D016054:DNA, Protozoan; D000939:Epitopes / Q000276:immunology; D005260:Female; D006367:HeLa Cells; D006790:Host-Parasite Interactions; D006801:Humans; D015151:Immunoblotting; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods; D015800:Protozoan Proteins; D011817:Rabbits; D011994:Recombinant Proteins / Q000378:metabolism; D014247:Trichomonas Vaginitis / Q000469:parasitology*; D014246:Trichomonas vaginalis / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology
chemical_list: C113260:AP33 protein, Trichomonas vaginalis; D000911:Antibodies, Monoclonal; D018076:DNA, Complementary; D016054:DNA, Protozoan; D000939:Epitopes; D008565:Membrane Proteins; D015800:Protozoan Proteins; D011994:Recombinant Proteins