title: Antigenic variation in the intestinal parasite Giardia lamblia.
abstract: Giardia lamblia trophozoites undergo antigenic variation, where one member of the Variant-specific Surface Protein (VSP) family is expressed on the surface of proliferating trophozoites and periodically replaced by another one. Two main questions have challenged researchers since antigenic switching was discovered in Giardia: What are the mechanisms involved? How are they influenced by other cellular processes or by the environment? Two molecular mechanisms have been proposed, both involving small non-coding RNAs. Here we postulate that (a) chromatin remodeling, triggered by environmental factors, also plays an important role in selecting the VSP that will be expressed and (b) the particular VSP structure may not only protect the parasite in the small intestine but also signal the need to exchange the existing VSP for another.
authors.affiliation: Laboratorio de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Católica de Córdoba, Argentina; Centro de Investigación y Desarrollo en Inmunología y Enfermedades Infecciosas (CIDIE-CONICET), Av. Armada Argentina 3555, CP X5016DHK, Córdoba, Argentina.
authors.forename: Pablo Rubén
authors.initials: PR
authors.lastname: Gargantini
authors.affiliation: Centro de Investigación y Desarrollo en Inmunología y Enfermedades Infecciosas (CIDIE-CONICET), Av. Armada Argentina 3555, CP X5016DHK, Córdoba, Argentina.
authors.forename: Marianela Del Carmen
authors.initials: MDC
authors.lastname: Serradell
authors.affiliation: Laboratorio de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Católica de Córdoba, Argentina; Centro de Investigación y Desarrollo en Inmunología y Enfermedades Infecciosas (CIDIE-CONICET), Av. Armada Argentina 3555, CP X5016DHK, Córdoba, Argentina.
authors.forename: Diego Nicolás
authors.initials: DN
authors.lastname: Ríos
authors.affiliation: Laboratorio de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Católica de Córdoba, Argentina; Centro de Investigación y Desarrollo en Inmunología y Enfermedades Infecciosas (CIDIE-CONICET), Av. Armada Argentina 3555, CP X5016DHK, Córdoba, Argentina.
authors.forename: Albano Heraldo
authors.initials: AH
authors.lastname: Tenaglia
authors.affiliation: Laboratorio de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Católica de Córdoba, Argentina; Centro de Investigación y Desarrollo en Inmunología y Enfermedades Infecciosas (CIDIE-CONICET), Av. Armada Argentina 3555, CP X5016DHK, Córdoba, Argentina. Electronic address: hlujan@ucc.edu.ar.
authors.forename: Hugo Daniel
authors.initials: HD
authors.lastname: Luján
mesh_terms: D000818:Animals; D000940:Antigenic Variation / Q000235:genetics / Q000276:immunology*; D000953:Antigens, Protozoan / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D042002:Chromatin Assembly and Disassembly / Q000235:genetics*; D016829:Giardia lamblia / Q000235:genetics / Q000276:immunology*; D005873:Giardiasis / Q000469:parasitology; D006801:Humans; D035683:MicroRNAs / Q000235:genetics; D011487:Protein Conformation; D015800:Protozoan Proteins / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics
chemical_list: D000953:Antigens, Protozoan; D035683:MicroRNAs; D015800:Protozoan Proteins; D034741:RNA, Small Interfering; C072464:variant surface protein H7, Giardia lamblia