Enhanced protocol for determining the 3' terminus of hepatitis C virus

Viral categorization and discovery in human circulation by transcriptome sequencing

Serum is the most common and easily accessible patient specimen in a minimally invasive manner. As a biological resource, RNA in serum has been less explored for its clinical utilization due to prevailing concerns regarding its high degradable nature. In the current study, however, we have documented the use of human serum RNA for viral categorization and discovery through transcriptome sequencing and analysis using well-curated databases and advanced bioinformatic tools. Such an integrated approach may have an immediate application in any clinical situations concerning with viral etiology.

Computational reconstruction of Bole1a, a representative synthetic hepatitis C virus subtype 1a genome

Hepatitis C virus (HCV) research is hampered by the use of arbitrary representative isolates in cell culture and immunology. The most replicative isolate in vitro is a subtype 2a virus (JFH-1); however, genotype 1 is more prevalent worldwide and represents about 70% of infections in the United States, and genotypes differ from one another by 31% to 33% at the nucleotide level. For phylogenetic and immunologic analyses, viruses H77 and HCV-1 (both subtype 1a) are commonly used based on their historic importance. In an effort to rationally design a representative subtype 1a virus (Bole1a), we used Bayesian phylogenetics, ancestral sequence reconstruction, and covariance analysis on a curated set of 390 full-length human HCV 1a sequences from GenBank. By design, Bole1a contains variations present in widely circulating strains and matches more epitope-sized peptides in a full-genome comparison to subtype 1a isolates than any other sequence studied. Parallel analyses confirm that selected epitopes from the Bole1a genome were able to elicit a robust T cell response. In a proof of concept for infectivity, the envelope genes (E1 and E2) of Bole1a were expressed in an HIV pseudoparticle system containing HCV envelope genes and HIV nonenvelope genes with luciferase expression. The resulting Bole1a pseudoparticle robustly infected Hep3B cells. In this study, we demonstrate that a rationally designed, fully synthetic HCV genome contains representative epitopes and envelope genes that assemble properly and mediate entry into target cells.