Frédéric Le Gal1,2, Ségolène Brichler1,2,3, Tudor Drugan4, Chakib Alloui1,2, Dominique Roulot2,5, Jean-Michel Pawlotsky3,6, Paul Dény1,7, Emmanuel Gordien1,2,3. 1. Laboratoire de Microbiologie Clinique, Hôpitaux Universitaires de Paris Seine Saint-Denis, Site Avicenne, Université Sorbonne Paris Cité, Bobigny, France. 2. Centre national de référence des virus des hépatites B, C et Delta, Laboratoire de Virologie, Bobigny, France. 3. Unité INSERM U955, Equipe 18, Créteil, France. 4. Department of Medical Informatics and Biostatistics, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania. 5. Unité d'Hépatologie, Hôpitaux Universitaires de Paris Seine Saint-Denis, Site Avicenne, Université Sorbonne Paris Cité, Bobigny, France. 6. Centre national de référence des virus des hépatites B, C et Delta, Département de Virologie, Hôpital Henri Mondor, Université Paris-Est, Créteil, France. 7. Centre de Recherches en Cancérologie de Lyon, INSERM U1052, UMR CNRS 5286, Team Hepatocarcinogenesis and Viral Infection, Lyon, France.
Abstract
Hepatitis delta virus (HDV) is responsible for the most severe form of acute and chronic viral hepatitis. We previously proposed that the Deltavirus genus is composed of eight major clades. However, few sequences were available to confirm this classification. Moreover, little is known about the structural and functional consequences of HDV variability. One practical consequence is the failure of most quantification assays to properly detect or quantify plasmatic HDV RNA. Between 2001 and 2014, 2,152 HDV strains were prospectively collected and genotyped in our reference laboratory by means of nucleotide sequencing and extensive phylogenetic analyses of a 400-nucleotide region of the genome (R0) from nucleotides 889 to 1289 encompassing the 3' end of the delta protein-coding gene. In addition, the full-length genome sequence was generated for 116 strains selected from the different clusters, allowing for in-depth characterization of the HDV genotypes and subgenotypes. This study confirms that the HDV genus is composed of eight genotypes (HDV-1 to HDV-8) defined by an intergenotype similarity >85% or >80%, according to the partial or full-length genome sequence, respectively. Furthermore, genotypes can be segregated into two to four subgenotypes, characterized by an intersubgenotype similarity >90% (>84% for HDV-1) over the whole genome sequence. Systematic analysis of genome and protein sequences revealed highly conserved functional nucleotide and amino acid motifs and positions across all (sub)genotypes, indicating strong conservatory constraints on the structure and function of the genome and the protein. CONCLUSION: This study provides insight into the genetic diversity of HDV and a clear view of its geographical localization and allows speculation as to the worldwide spread of the virus, very likely from an initial African origin. (Hepatology 2017;66:1826-1841).
Hepatitis delta virus (HDV) is responsible for the most severe form of acute and chronic viral hepatitis. We previously proposed that the Deltavirus genus is composed of eight major clades. However, few sequences were available to confirm this classification. Moreover, little is known about the structural and functional consequences of HDV variability. One practical consequence is the failure of most quantification assays to properly detect or quantify plasmatic HDV RNA. Between 2001 and 2014, 2,152 HDV strains were prospectively collected and genotyped in our reference laboratory by means of nucleotide sequencing and extensive phylogenetic analyses of a 400-nucleotide region of the genome (R0) from nucleotides 889 to 1289 encompassing the 3' end of the delta protein-coding gene. In addition, the full-length genome sequence was generated for 116 strains selected from the different clusters, allowing for in-depth characterization of the HDV genotypes and subgenotypes. This study confirms that the HDV genus is composed of eight genotypes (HDV-1 to HDV-8) defined by an intergenotype similarity >85% or >80%, according to the partial or full-length genome sequence, respectively. Furthermore, genotypes can be segregated into two to four subgenotypes, characterized by an intersubgenotype similarity >90% (>84% for HDV-1) over the whole genome sequence. Systematic analysis of genome and protein sequences revealed highly conserved functional nucleotide and amino acid motifs and positions across all (sub)genotypes, indicating strong conservatory constraints on the structure and function of the genome and the protein. CONCLUSION: This study provides insight into the genetic diversity of HDV and a clear view of its geographical localization and allows speculation as to the worldwide spread of the virus, very likely from an initial African origin. (Hepatology 2017;66:1826-1841).
Authors: Peter A Revill; Thomas Tu; Hans J Netter; Lilly K W Yuen; Stephen A Locarnini; Margaret Littlejohn Journal: Nat Rev Gastroenterol Hepatol Date: 2020-05-28 Impact factor: 46.802
Authors: Emily K Butler; Mary A Rodgers; Kelly E Coller; Devin Barnaby; Elizabeth Krilich; Ana Olivo; Michael Cassidy; Dora Mbanya; Lazare Kaptue; Nicaise Ndembi; Gavin Cloherty Journal: Sci Rep Date: 2018-08-02 Impact factor: 4.379