Project description:We identified four virulence phenotypes of Rickettsia prowazekii (the deadly agent of epidemic typhus) that are associated with the upregulation of antiapoptotic genes (virulent strain) or the Interferon I pathway (avirulent). Transcriptional and proteomic analyses of R. prowazekii linked surface protein expression and methylation with virulence. By sequencing a virulent strain and using comparative genomics, we found hotspots of mutations in homopolymeric tracts of poly(A) and poly(T) that lead to gene split and inactivation and explain the loss of virulence in the vaccine strain. These areas of instability explains adaptive mutations leading to virulence recovery in the vaccine strain.
Project description:We identified four virulence phenotypes of Rickettsia prowazekii (the deadly agent of epidemic typhus) that are associated with the upregulation of antiapoptotic genes (virulent strain) or the Interferon I pathway (avirulent). Transcriptional and proteomic analyses of R. prowazekii linked surface protein expression and methylation with virulence. By sequencing a virulent strain and using comparative genomics, we found hotspots of mutations in homopolymeric tracts of poly(A) and poly(T) that lead to gene split and inactivation and explain the loss of virulence in the vaccine strain. These areas of instability explains adaptive mutations leading to virulence recovery in the vaccine strain.
Project description:We identified four virulence phenotypes of Rickettsia prowazekii (the deadly agent of epidemic typhus) that are associated with the upregulation of antiapoptotic genes (virulent strain) or the Interferon I pathway (avirulent). Transcriptional and proteomic analyses of R. prowazekii linked surface protein expression and methylation with virulence. By sequencing a virulent strain and using comparative genomics, we found hotspots of mutations in homopolymeric tracts of poly(A) and poly(T) that lead to gene split and inactivation and explain the loss of virulence in the vaccine strain. These areas of instability explains adaptive mutations leading to virulence recovery in the vaccine strain. Transcriptional analysis of two different strains growing in L929 cells. A virulent strain (Rp22) was compared to a avirulent strain (Erus). The experiment was performed with 3 independant biological replicates.
Project description:We developed a typing method that can differentiate 8 strains of Rickettsia prowazekii into 7 genotypes. This method can be used to type and trace the origin of R. prowazekii isolated from samples collected during epidemics after a bioterrorism attack.
