title: Comparison of envelope 2 CD81 binding regions in PBMC-derived versus serum-derived hepatitis C virus isolates: higher conservation of CD81 region 2 in PBMC isolates.
abstract: The aim of the present study was to investigate the variability of hepatitis C virus (HCV) CD81 binding regions (CD81-1/2) in peripheral blood mononuclear cells (PBMC)-derived and serum-derived HCV-RNA samples. HCV-RNA was isolated from PBMC (10⁴ cells) and serum samples from 37 patients chronically infected with HCV genotype 1a/1b (n=21/16). The hypervariable regions 1/2 (amino acid 384-410, amino acid 474-482) and regions CD81-1/2 (amino acid 474-494, amino acid 522-551) were analysed. Mutational frequency of amino acid sequences was compared between PBMC-derived and serum-derived HCV variants as well as local accumulation of mutations. Furthermore, CD81 was quantified on PBMC. Mutational frequency was not different between PBMC-derived and serum-derived HCV variants. A trend to lower mutational frequency in genotype 1a PBMC variants compared with serum-derived variants was observed in region CD81-2 (5%vs 10%). Smoothed mutational frequency analysis showed a significantly lower variability within genotype 1a CD81-2 in PBMC-derived compared to serum-derived HCV-RNA (P=0.026). CD81 expression on PBMC was not correlated with the number of mutations within the CD81 binding regions.
  
  
  CONCLUSIONS
  A higher conservation was observed in region CD81-2 in PBMC-derived versus serum-derived HCV-RNA indicating selection of HCV variants on PBMC. The variability in the CD81 binding regions appeared to be independent from CD81 expression.
authors.affiliation: Klinikum der Johann Wolfgang Goethe-Universität, Medizinische Klinik 1, Frankfurt am Main, Germany.
authors.forename: M-W
authors.initials: MW
authors.lastname: Welker
authors.forename: C
authors.initials: C
authors.lastname: Welsch
authors.forename: D
authors.initials: D
authors.lastname: Ochs
authors.forename: W P
authors.initials: WP
authors.lastname: Hofmann
authors.forename: E
authors.initials: E
authors.lastname: Herrmann
authors.forename: A
authors.initials: A
authors.lastname: Piiper
authors.forename: R W
authors.initials: RW
authors.lastname: Hartmann
authors.forename: S
authors.initials: S
authors.lastname: Zeuzem
authors.forename: C
authors.initials: C
authors.lastname: Sarrazin
authors.forename: B
authors.initials: B
authors.lastname: Kronenberger
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D015703:Antigens, CD / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D014644:Genetic Variation; D005838:Genotype; D016174:Hepacivirus / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D019698:Hepatitis C, Chronic / Q000097:blood* / Q000276:immunology / Q000821:virology; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D017354:Point Mutation; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D018709:Statistics, Nonparametric; D060225:Tetraspanin 28; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism
chemical_list: D015703:Antigens, CD; C554798:CD81 protein, human; D012367:RNA, Viral; D060225:Tetraspanin 28; D014759:Viral Envelope Proteins