On Hepatitis C Virus Evolution: The Interaction between Virus and Host towards Treatment Outcome
MetadataShow full item record
Background:Hepatitis C is a disease spread throughout the world. Hepatitis C virus (HCV), the etiological agent of this disease, is a single-stranded positive RNA virus. Its genome encodes a single precursor protein that yields ten proteins after processing. NS5A, one of the non-structural viral proteins, is most associated with interferon-based therapy response, the approved treatment for hepatitis C in Brazil. HCV has a high mutation rate and therefore high variability, which may be important for evading the immune system and response to therapy. The aim of this study was to analyze the evolution of NS5A quasispecies before, during, and after treatment in patients infected with HCV genotype 3a who presented different therapy responses.Methods:Viral RNA was extracted, cDNA was synthesized, the NS5A region was amplified and cloned, and 15 clones from each time-point were sequenced. The sequences were analyzed for evolutionary history, genetic diversity and selection.Results:This analysis shows that the viral population that persists after treatment for most non-responder patients is present in before-treatment samples, suggesting it is adapted to evade treatment. In contrast, the population found in before treatment samples from most end-of-treatment responder patients either are selected out or appears in low frequency after relapse, therefore changing the population structure. The exceptions illustrate the uniqueness of the evolutionary process, and therefore the treatment resistance process, in each patient.Conclusion:Although evolutionary behavior throughout treatment showed that each patient presented different population dynamics unrelated to therapy outcome, it seems that the viral population from non-responders that resists the treatment already had strains that could evade therapy before it started. © 2013 Bittar et al.
How to cite this document
Showing items related by title, author, creator and subject.
Detection of serum antibodies to parainfluenza type 3 virus, respiratory syncytial virus, bovine viral diarrhea virus, and herpes virus type 1 in sheep in the region of Botucatu, São Paulo - Brazil Gonçalves, Roberto Calderon ; Silva, Andreza Amaral da ; Ferreira, Danilo Otávio Laurenti ; Marcondes, Júlio Simões ; Pituco, Edwiges Maristela; Dias, Adriano (African Journal of Agricultural Research, 2011) [Artigo]Occurrence of various livestock diseases particularly foot and mouth disease, infectious bursal disease, contagiuos bovine pleuro pneumonia, babesiosis and trypanosomosis were established among the Fulani community of ...
Impact of Epstein-Barr virus load, virus genotype, and frequency of the 30bp deletion in the viral BNLF-1 gene in patients harboring the human immunodeficiency virus Giron, Leila Bertoni ; Ramos da Silva, Suzane ; Barbosa, Alexandre Naime ; Monteiro de Barros Almeida, Ricardo Augusto ; Rosário de Souza, Lenice do ; Oliveira, Deilson Elgui de (Journal of Medical Virology, 2013) [Artigo]Patients infected with the human immunodeficiency virus (HIV) are at higher risk of developing Epstein-Barr Virus (EBV)-associated lymphomas. The usefulness of monitoring EBV in peripheral blood mononuclear cells (PBMCs) ...
Coxiella burnetii associated with BVDV (Bovine Viral Diarrhea Virus), BoHV (bovine herpesvirus), Leptospira spp., Neospora caninum, Toxoplasma gondii and trypanosoma vivax in reproductive disorders in cattle Zanatto, Diego Carlos Souza ; Gatto, Igor Renan Honorato ; Labruna, Marcelo Bahia; Jusi, Marcia Mariza Gomes; Samara, Samir Issa ; Machado, Rosangela Zacarias ; André, Marcos Rogério (Revista Brasileira de Parasitologia Veterinaria, 2019) [Artigo]This is a cross-sectional study to assess the presence of antibodies in ruminants against selected pathogens associated with reproductive disorders in cattle in four Brazilian states, including the zoonotic agent Coxiella ...