info:eu-repo/semantics/article
Antigenic variation in Giardia lamblia is regulated by RNA interference
Autor
Prucca, César G.
Slavin, Ileana
Quiroga, Rodrigo
Elías, Eliana Vanina
Rivero, Fernando David
Saura, Alicia
Carranza, Pedro Gabriel
Luján, Hugo Daniel
Institución
Resumen
Giardia lamblia (also called Giardia intestinalis) is one of the most common intestinal parasites of humans. To evade the host's immune response, Giardia undergoes antigenic variation - a process that allows the parasite to develop chronic and recurrent infections. From a repertoire of ∼190 variant-specific surface protein (VSP)-coding genes, Giardia expresses only one VSP on the surface of each parasite at a particular time, but spontaneously switches to a different VSP by unknown mechanisms. Here we show that regulation of VSP expression involves a system comprising RNA-dependent RNA polymerase, Dicer and Argonaute, known components of the RNA interference machinery. Clones expressing a single surface antigen efficiently transcribe several VSP genes but only accumulate transcripts encoding the VSP to be expressed. Detection of antisense RNAs corresponding to the silenced VSP genes and small RNAs from the silenced but not for the expressed vsp implicate the RNA interference pathway in antigenic variation. Remarkably, silencing of Dicer and RNA-dependent RNA polymerase leads to a change from single to multiple VSP expression in individual parasites. Fil: Prucca, César G. Universidad Católica de Córdoba. Facultad de Ciencias de la Salud; Argentina Fil: Slavin, Ileana. Universidad Católica de Córdoba. Facultad de Ciencias Químicas; Argentina Fil: Quiroga, Rodrigo. Universidad Católica de Córdoba. Facultad de Ciencias Químicas; Argentina Fil: Elías, Eliana Vanina. Universidad Católica de Córdoba. Facultad de Ciencias Químicas; Argentina Fil: Rivero, Fernando David. Universidad Católica de Córdoba. Facultad de Ciencias Químicas; Argentina Fil: Saura, Alicia. Universidad Católica de Córdoba. Facultad de Ciencias Químicas; Argentina Fil: Carranza, Pedro Gabriel. Universidad Católica de Córdoba. Facultad de Ciencias Químicas; Argentina Fil: Luján, Hugo Daniel. Universidad Católica de Córdoba. Facultad de Ciencias Químicas; Argentina