Trichomonas vaginalis NYH286 phenotypic variation may be coordinated for a repertoire of trichomonad surface immunogens.
Trichomonas vaginalis isolate NYH286 was fractionated with immunoglobulin G of sera from patients with trichomoniasis. Subpopulations of trichomonads with phenotypes of either patient serum-immunoglobulin G reactive (PS+) or nonreactive (PS-) were obtained. Flow cytofluorometry of PS+ and PS- subpopulations with a monoclonal antibody called C20A3 which reacts with a high-molecular-weight immunogen of T. vaginalis gave corresponding fluorescent (positive) and nonfluorescent (negative) phenotypes. No relationship was seen between PS+ and PS- phenotypes and binding of soybean agglutinin, wheat germ agglutinin, and concanavalin A, showing that PS- organisms still possessed carbohydrate moieties on their surfaces based on lectin binding. Phenotypic variation among the PS+ and PS- trichomonads was observed during in vitro growth. A positive-to-negative phenotype shift was also recorded for parasites obtained from lesions of mice subcutaneously infected with PS+ trichomonads. The involvement of surface proteins in the differential PS+ and PS- reactions was supported by soluble antigen and whole cell radioimmunoprecipitation assays. Finally, enhanced parasitism and killing of HeLa cells in monolayer cultures were observed for PS- subpopulations as compared with PS+ counterparts. The data support the idea that phenotypic variation for T. vaginalis may be coordinated for a repertoire of trichomonad immunogens and that such membrane dynamics influence expression of virulence determinants for these sexually transmitted disease agents.
D000911:Antibodies, Monoclonal; D000953:Antigens, Protozoan / Q000276:immunology*; D000954:Antigens, Surface / Q000276:immunology*; D002448:Cell Adhesion; D005434:Flow Cytometry; D006367:HeLa Cells; D037102:Lectins; D010641:Phenotype; D014245:Trichomonas Infections / Q000276:immunology*; D014246:Trichomonas vaginalis / Q000276:immunology* / Q000472:pathogenicity
D000911:Antibodies, Monoclonal; D000953:Antigens, Protozoan; D000954:Antigens, Surface; D037102:Lectins