title: TT virus is distributed in various leukocyte subpopulations at distinct levels, with the highest viral load in granulocytes.
abstract: When TT virus (TTV) DNA was quantitated in whole blood and plasma aliquots from 27 viremic individuals by real-time detection PCR that can detect essentially all TTV genotypes, the TTV load was 6.9 +/- 3.5 (mean +/- standard deviation)-fold higher in the whole blood than in the plasma samples [P < 0.002 (paired t test)]. To clarify the reason for this difference, peripheral blood cells of various types including red blood cells, granulocytes (CD15+), B cells (CD19+), T cells (CD3+), monocytes (CD14+), and NK cells (CD3-/CD56+) were separated at a purity of 95.4-99.5% from each of three infected individuals with relatively high TTV viremia, and their TTV viral loads were determined. Red blood cells were uniformly negative, but the other cell types were positive for TTV DNA at various titers. In all three patients, the highest TTV load was found in granulocytes (4.2 x 10(4)-3.1 x 10(5) copies/10(6) cells), followed by monocytes (1.4-2.2 x 10(4) copies/10(6) cells) and NK cells (5.4-6.5 x 10(3) copies/10(6) cells); B and T cells were positive, with a low viral load (6.7 x 10(1)-2.7 x 10(3) copies/10(6) cells). These results indicate that TTV is distributed in various peripheral blood cell types at distinct levels, with the highest viral load in granulocytes, and that a significant proportion of the TTV DNA in peripheral blood is not identified by the standard plasma/serum DNA detection methods.
authors.affiliation: Immunology Division and Division of Molecular Virology, Jichi Medical School, 3311-1 Yakushiji, Minamikawachi-Machi, Tochigi-Ken 329-0498, Japan.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Takahashi
authors.forename: Shinichi
authors.initials: S
authors.lastname: Asabe
authors.forename: Yuhko
authors.initials: Y
authors.lastname: Gotanda
authors.forename: Junichi
authors.initials: J
authors.lastname: Kishimoto
authors.forename: Fumio
authors.initials: F
authors.lastname: Tsuda
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Okamoto
mesh_terms: D000328:Adult; D018941:Antigens, CD19 / Q000096:biosynthesis; D001402:B-Lymphocytes / Q000821:virology; D017252:CD3 Complex / Q000096:biosynthesis; D019002:CD56 Antigen / Q000096:biosynthesis; D002469:Cell Separation; D004279:DNA, Viral / Q000032:analysis / Q000097:blood; D004912:Erythrocytes / Q000821:virology; D005260:Female; D005838:Genotype; D006098:Granulocytes / Q000821:virology*; D006801:Humans; D007694:Killer Cells, Natural / Q000821:virology; D016256:Lewis X Antigen / Q000096:biosynthesis; D018950:Lipopolysaccharide Receptors / Q000096:biosynthesis; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000821:virology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000821:virology; D022783:Torque teno virus / Q000378:metabolism*
chemical_list: D018941:Antigens, CD19; D017252:CD3 Complex; D019002:CD56 Antigen; D004279:DNA, Viral; D016256:Lewis X Antigen; D018950:Lipopolysaccharide Receptors