title: Infection of circulating CD34+ cells by HHV-8 in patients with Kaposi's sarcoma.
abstract: Human herpesvirus type 8 (HHV-8) has been identified as the most likely candidate to be involved in the development of Kaposi's Sarcoma (KS). HHV-8 has been associated with all forms of KS, primary effusion lymphoma, and multicentric Castleman's disease and detected in various non-neoplastic cells. Its presence in cells of the different hemopoietic lineages has not yet been investigated in a comprehensive and systematic manner. In this study we searched for the presence of HHV-8 in different subpopulations of peripheral blood mononuclear cells (PBMC) from patients with classic and AIDS-associated KS, as well as from HIV-1 sero-positive and sero-negative persons without KS. Thirty-four samples of PBMC were isolated from 30 patients. Subpopulations were isolated with immunomagnetic beads. Polymerase chain reaction for HHV-8 DNA was performed on PBMC and subpopulations with a primer pair selected from ORF26 of the viral genome. Polymerase chain reaction products were subsequently Southern blotted and hybridized. In patients with KS, HHV-8 DNA was detected in nine of 11 (81%) CD19+ cells, four of 11 (36%) CD2+ cells, three of 11 (27%) CD14+ cells, and nine of 11 (81%) of the remaining depleted cell populations (DP) that contain CD34 positive cells. In a subsequent set of experiments HHV-8 DNA was detected in 10 of 12 (83%) CD34 positive cell fractions. All cell subpopulations from the non-KS group were HHV-8 negative, with the exception of one positive B cell sample obtained from an HIV-infected patient. Our data demonstrate that in peripheral blood HHV-8 is detectable not only in CD19+ cells, as previously reported, but also in other cells, including T cells, monocytes, and cells devoid of specific lineage markers. We also show for the first time that CD34+ cells in peripheral blood of KS patients are a predominant HHV-8-harboring population, suggesting that they represent an additional important reservoir for this virus in vivo.
authors.affiliation: Division of Immunology, Allergy and Infectious Diseases, Department of Dermatology, Vienna Medical School, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Henry
authors.forename: A
authors.initials: A
authors.lastname: Uthman
authors.forename: A
authors.initials: A
authors.lastname: Geusau
authors.forename: A
authors.initials: A
authors.lastname: Rieger
authors.forename: L
authors.initials: L
authors.lastname: Furci
authors.forename: A
authors.initials: A
authors.lastname: Lazzarin
authors.forename: P
authors.initials: P
authors.lastname: Lusso
authors.forename: E
authors.initials: E
authors.lastname: Tschachler
mesh_terms: D018941:Antigens, CD19 / Q000032:analysis; D018952:Antigens, CD34 / Q000032:analysis*; D004279:DNA, Viral / Q000097:blood; D019288:Herpesvirus 8, Human / Q000302:isolation & purification*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000821:virology*; D016133:Polymerase Chain Reaction; D012514:Sarcoma, Kaposi / Q000821:virology*
chemical_list: D018941:Antigens, CD19; D018952:Antigens, CD34; D004279:DNA, Viral