title: Herpesvirus saimiri immortalization of alpha beta and gamma delta human T-lineage cells derived from CD34+ intrathymic precursors in vitro.
abstract: Herpesvirus saimiri (HVS), an agent that can infect many human cell types, has been shown to immortalize selectively TCR alpha beta + CD3+ T lymphocytes. Human T cell precursors defined as CD34+CD3-CD4-CD8- were isolated from thymic samples and exposed to HVS in the presence of either IL-2 or IL-7. Cultures lacking the virus were non-viable by day 15. Test cultures, in contrast, showed a sustained proliferative activity lasting > 5 months, allowing the phenotypical and molecular analysis of the cellular progeny. In the presence of IL-7, TCR alpha beta + cells with three different phenotypes (mainly CD4+CD8-, but also CD4+CD8+ and CD4-CD8+) were immortalized, whereas no TCR gamma delta + cells were recovered. Kinetic studies showed that the expansion of immortalized TCR alpha beta + cells was preceded by a gradual loss of CD34+ cells followed by a transient accumulation of two distinct cell subsets: first CD1+CD4+CD3- cells and then CD4+CD8+ thymocytes. This resembles early phenotypic changes occurring during normal intrathymic T cell development. In the presence of IL-2, in contrast, only TCR gamma delta + cells were immortalized (mainly CD4-CD8+, but also CD4-CD8-). The results show that HVS can be used to read the CD3+ cellular outcome of T cell differentiation assays, including gamma delta + CD4-CD8+, gamma delta + CD4-CD8-, alpha beta + CD4+CD8-, alpha beta + CD4-CD8+ and alpha beta + CD4+CD8+ T cells. A clear role for different cytokines (IL-2 for gamma delta + cells, IL-7 for alpha beta + cells) in early T cell commitment was also apparent.
authors.affiliation: Facultad de Medicina, Universidad Complutense, Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Pacheco-Castro
authors.forename: C
authors.initials: C
authors.lastname: Márquez
authors.forename: M L
authors.initials: ML
authors.lastname: Toribio
authors.forename: A R
authors.initials: AR
authors.lastname: Ramiro
authors.forename: C
authors.initials: C
authors.lastname: Trigueros
authors.forename: J R
authors.initials: JR
authors.lastname: Regueiro
mesh_terms: D018952:Antigens, CD34 / Q000032:analysis* / Q000276:immunology; D002471:Cell Transformation, Neoplastic; D002675:Child, Preschool; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D006567:Herpesvirus 2, Saimiriine / Q000472:pathogenicity*; D006801:Humans; D007223:Infant; D015851:Interleukin-7 / Q000494:pharmacology; D016209:Interleukin-8 / Q000494:pharmacology; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000032:analysis*; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000032:analysis*; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000821:virology*; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology*
chemical_list: D018952:Antigens, CD34; D015851:Interleukin-7; D016209:Interleukin-8; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta